journal of the association of professional...

JOURNAL OF THE

ASSOCIATION OF

PROFESSIONAL ENGINEERS OF TRINIDAD & TOBAGO

Volume 45 • Number 1 (ISSN 1000 7924) • July 2017

Special Issue on Innovative Engineering Solutions for the Caribbean (for The 2016 APETT Annual Technical Conference, June 2016)

Editorial………………………………………………………………………….……………... .. 2

An Android Application for Detection and Self-monitoring of the Diabetic Foot Ulcer………... 4

Municipal Wastewater Treatment and Associated Bioenergy Generation Using Anaerobic Granular Bed Baffled Reactor…………………………………………………………………… 11

Production of Plant Extracts by Supercritical Fluid Extraction……………………………….20

Some Examples of Innovative Projects in the Manufacturing Sector in Trinidad and Tobago …. 26

The Status of Remote Sensing Information in Capturing and Applying to Environmental Resources ……..……….……………………………………………………………………... 32

Plastic Waste to Petrochemical Feedstock in Trinidad and Tobago …………………………….. 42

Commuter Experience in Developing Sustainable Transit Connectivity in Diego Martin, Trinidad and Tobago …………………………………………………………………………… 50

Abstracts of The 2016 APETT Annual Technical Conference (Theme: “Innovative Engineering

Solutions for the Caribbean”, 23rd-24th June 2016) …………………….…………………….. 59

Editor-in-Chief: Kit Fai Pun Guest Editor: Chris Maharaj

PRESIDENTS OF THE ASSOCIATION OF PROFESSIONAL ENGINEERS OF TRINIDAD AND TOBAGO

1959-1960 Rupert V.S. Aleong 1993-1994 Clément A. C. Imbert 1961-1962 Rupert D. Archibald 1994-1995 Leopold C. Martin 1963-1964 R. K. Bates 1995-1996 Samuel R. Narinjit 1965-1966 Karl Seheult 1996-1997 Merlyn Ramjohn 1967-1968 Kenneth S. Julien 1997-1998 Francis E. Paul 1969-1970 R.A. Thomas 1998-1999 Jerry B. Medford 1971-1972 Fenrick R. DeFour 1999-2000 Winston A. Mellowes 1973-1974 Majid Ibrahim 2000-2001 Imtiaz Hosein 1975-1976 Harry O. Phelps 2001-2002 Clifford G. Murray 1976-1977 Aldwyn L. Lequay 2002-2003 Anthony C. Farrell 1977-1978 Ignatius D. C. Imbert 2003-2004 Winston G. Lewis 1979-1980 Selwyn Lee Young 2004-2005 Chandrabhan Sharma 1980-1981 Basil M. Pashley 2005-2006 Geoffrey M. Abdulah 1981-1982 Richard E.K. Inniss 2006-2007 Mark D. Francois 1982-1983 J. V. Bowles 2007-2008 Vaughn I. Lezama 1983-1984 Winston M. L. Riley 2008-2009 Ahmin Z. Baksh 1984-1985 Myron Wing-Sang Chin 2009-2010 Hannah Wei-Muddeen 1985-1986 Winston H. E. Suite 2010-2011 Richard Saunders 1986-1987 Cecil I. Chin 2011-2012 Rae J. Furlonge 1987-1988 Gerald L. Webb 2012-2013 Narine Singh 1988-1989 Alvin C. Lutchman 2013-2014 Margarita Leonard 1989-1990 Denis R. Singh 2014-2015 Haydn I. Furlonge 1990-1991 Stephen J.G. Gift 2015-2016 Neil Dookie 1991-1992 Emile S. Charles 2016-2017 Fazir Khan 1992-1993 Hollis Charles 2017-2018 Imtiaz Easahak

FOUNDATION MEMBERS OF THE

ASSSOCIATION OF PROFESSIONAL ENGINEERS OF TRINIDAD AND TOBAGO IN 1959

Rupert V.S. Aleong (Founding President) Keith I. Allahar Rupert D. Archibald Don D. Ash Rudolph Balgaroo Luther A. Boyce Fenrick R. De Four

Leslie G. Dookie Roderick E. Douglas Luis G. Felipes Kenneth W. Finch Cecil M. Fung Emmanuel J. Guevara A. Majid Ibrahim Richard Inniss

Granville R. Johnston Curtis L. U. Knight Aldwyn Lequay Winston Manson-Hing Basil Pashley Harry O. Phelps Karl F. Seheult Cecil R. St. Hill

Peter F. Walker Errol A. Williams Note: APETT’s logo was designed by Derek Aleong.

JAPETT; Vol. 45, No.1, July 2017

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JOURNAL OF THE ASSOCIATION OF PROFESSIONAL ENGINEERS OF TRINIDAD & TOBAGO

2 Editorial

4 An Android Application for Detection and Self-monitoring of the Diabetic Foot Ulcer by Keri Gobin and Karen Louison

11 Municipal Wastewater Treatment and Associated Bioenergy Generation using Anaerobic Granular Bed Baffled Reactor by Kiran Tota-Maharaj, Joseph Akunna and Denver Cheddie

20 Production of Plant Extracts by Supercritical Fluid Extraction by Sharad Maharaj, Marian J. Watson, Rosemarie Skeene, and David R. McGaw

26 Some Examples of Innovative Projects in the Manufacturing Sector in Trinidad and Tobago by Roger A. Camacho

32 The Status of Remote Sensing Information in Capturing and Applying to Environmental Resources by Pramenath Narinesingh

42 Plastic Waste to Petrochemical Feedstock in Trinidad and Tobago by Jeffrey V. Smith, Sydney Thomas, Lebert H. Grierson, and Alan J. Harper

50 Commuter Experience in Developing Sustainable Transit Connectivity in Diego Martin, Trinidad and Tobago by Hawwa Hassan, Rae J. Furlonge, and Bheshem Ramlal

59 Abstracts of The 2016 APETT Annual Technical Conference (Theme: “Innovative Engineering Solutions for the Caribbean”, 23rd-24th June 2016) by The Association of Professional Engineers of Trinidad and Tobago

Volume 45 • Number 1 (ISSN 1000 7924) • July 2017

Editor-in-Chief: Professor Kit Fai Pun

Industrial Engineering Office Faculty of Engineering

University of the West Indies St Augustine

Trinidad and Tobago West Indies

[email protected]

Head Office of the Association: Professional Centre,

11-13 Fitz Blackman Drive, P.O. Box 935, Port of Spain,

Trinidad, West Indies

Tel/Fax: 1-868-627-6697 E-mail: [email protected] Website: www.apett.org

The Journal, JAPETT (ISSN 1000 7924) is a publication of the Association of Professional Engineers of Trinidad and Tobago. One volume (with 1-2 issues) is published annually in April and/or October, and is circulated to all members of the Association, all member institutions of the Council of Caribbean Engineering Organisations, and to a number of technical libraries within the Republic. Responsibility for the contents rest upon the authors and not upon the Association or its members.. Individual copies: members first copy of a volume free for members; non-members US$25 per volume. Member copies of journals are for personal use only. Copyright and Reprint Permissions: Abstracting is permitted with credit to the source. For other copying, reprint, or reproduction permission, write to the Head Office of the Association. All rights reserved. Copyright© 2017 by the Association of Professional Engineers of Trinidad and Tobago. Printed in Trinidad and Tobago. Postmaster: Send address changes to The Head Office of the Association: Professional Centre, 11-13 Fitz Blackman Drive, P.O. Box 935, Port of Spain, Trinidad, West Indies; Printed in Trinidad and Tobago.

JAPETT; Vol. 45, No.1, July 2017; Editorial

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Editorial

I. Notes from the Editors The Association of Professional Engineers of Trinidad and Tobago (APETT) hosted its 2016 Annual Technical Conference (ATC) on the theme of “Innovative Engineering Solutions for the Caribbean”, that was held at NESC Auditorium, Point Lisas, Trinidad on 23rd-24th June 2016. A total of 36 invited speeches, scheduled professional/technical presentations were made together with panel discussions, addressing various topics and areas associated with the conference theme.

In line with the APETT Journal’s aim to provide a broad coverage of subjects relating to engineering, presenters were invited to extend the scope and contents of their presentations/contributions to meet the engineering rigor for this Special Issue of the Journal of APETT. Preference will be given to papers describing original engineering work, or material of specific interest to engineers and those working in related fields, in Trinidad and Tobago (T&T) and the Caribbean region. After a rigorous peer review process, seven (7) manuscripts were published in this issue that demonstrated a balanced set of quality contributions originated from the Conference.

II. About This Issue This Special Issue (Volume 45 Number 1) of the Journal includes seven (7) articles and 33 abstracts of technical papers submitted to The 2016 APETT Annual Technical Conference. The relevance and usefulness of the seven articles are summarised below.

K. Gobina and K. Louison, “An Android Application for Detection and Self-monitoring of the Diabetic Foot Ulcer”, introduce a telemedicine method for self-assessment of the diabetic patients’ foot in Trinidad and Tobago (T&T). An infra-red camera attachment for a mobile device allowed the acquisition of thermal and optical lower limb images from a small sample of healthy subjects and diabetic patients with foot ulcers. The data was then utilised in the design, development and testing of an Android application software prototype. Based on the findings, this Android application allows the input and recording of the patient’s required information, selection of thermal and optical images and then easy transmission of pertinent information, via the method of choice to the designated clinician. This application is designed with the older or novice user in mind and should encourage the more regular home-monitoring of the diabetic foot ulcer necessary to reduce the severe effects of its complications.

Based on their work, “Municipal Wastewater Treatment and Associated Bioenergy Generation Using Anaerobic Granular Bed Baffled Reactor (GRABBR)”, K. Tota-Maharaj, J. Akunnab and D. Cheddie, assess efficacy of municipal wastewater treatment at high organic

loading rates under varying temperatures. Results showed that for the two mesophilic temperatures tested (37⁰C and 25⁰C) under steady state conditions, the removal of Chemical Oxygen Demand (COD) and Biochemical Oxygen Demand (BOD) was 80 to 90 %. At lower organic loadings, the reactor operated as a completely mixed system with most of the treatment occurring in the first two compartments. The GRABBR also showed very high solids retention with low effluent suspended solids concentration for various organic and hydraulic conditions. Applications of GRABBR system could be an economical option reducing the cost to achieve similar treatment goals for high strength wastewaters.

S. Maharaj et al., “Production of Plant Extracts by Supercritical Fluid Extraction”, present a case for the introduction of a flexible commercial Supercritical Fluid Extraction (SFE) operation in T&T. Typical raw materials would be waste products from food processing. Background research on the extraction characteristics of most of the potential raw materials has been carried out on bench scale SFE units at The University of the West Indies (UWI). Typical data for pumpkin seeds and ylang ylang is presented, giving extraction curves (% extraction with time), variation of total quantum of extraction with varying processing conditions (operating pressure and temperature), as well as product quality as evidenced by chromatographic analysis. By way of example, the economic feasibility of a plant to produce the extract of turmeric, being marketed at the current world price of US$50 per kg, on the basis of a 310 day per year operation with a 3-hour turn-around time gave an internal rate of return (IRR) of 21% on a 5-year projection. It demonstrates that such an operation could be commercially feasible and a Business Plan should be developed to move the concept forward.

In his paper, “Some Examples of Innovative Projects in the Manufacturing Sector in Trinidad and Tobago”, R. A. Camacho explores the opportunity for engineers to create and execute innovative projects in manufacturing companies. This paper presents four (4) innovative projects completed over the last few decades that were designed, built, tested and put into service in one factory in T&T. It aims to stimulate the engineering community and shows to the national and regional manufacturing sector that innovative solutions to problems need not require huge sums of money to implement and higher technical degrees to conceive and analyse. Experience has shown that companies with the foresight and willingness to take the risk by implementing many small innovative projects and new ideas over time will have the competitive advantage over other manufacturers of similar products.

P. Narinesingh, “The Status of Remote Sensing Information in Capturing and Applying Environmental Resources”, explores the use and availability of Remote Sensing Information for environmental projects. The

JAPETT; Vol. 45, No.1, July 2017; Editorial

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remote sensing technology and the advancement in Geographic Information System make it easy to capture environmental data rapidly, almost anywhere on the planet, and in real time accurately process it into useful information. This technology is widely used outside the Caribbean Islands (e.g. to reduce risk and increase production in agriculture), while significant sums of monies would be spent in projects with a paucity of data. The absence of adequate data would result in non-sustainable planning solutions and less efficient development. Through the integration of information from Satellite and Earth Observation Systems from around the world, better informed decisions may be made regarding biodiversity and ecosystem sustainability, disaster resilience, food security, sustainable urban development, and water resources management given the anticipated dramatic fluctuation in weather.

J.V. Smith et al., “Plastic Waste to Petrochemical Feedstock in Trinidad and Tobago”, review the background and the history of PET applications with particular reference to Trinidad and Tobago (T&T). Common alternative manufacturing routes for PET and alternative approaches available for the recycling of waste PET, including physical, chemical and energy valorisation options, are discussed. As a direct application of the discipline of Industrial Symbiosis (IS) in a T&T perspective, the methanolysis of waste PET to produce dimethyl terephthalate (DMT) and ethylene glycol (EG) is explored. The benefits of the implementation of this recycling option could be threefold: providing alternative feedstock, reducing foreign currency outflows and tackling an environmental problem. It is anticipated that the review would stimulate interest and set a start line for further research and industrial cooperation.

In their article, “Commuter Experience in Developing Sustainable Transit Connectivity in Diego Martin, Trinidad and Tobago”, H. Hassan, R.J. Furlonge, and B. Ramlal, provides practical and implementable measures to alleviate the current transportation problems in Diego Martin, T&T. Data was collected from both primary and secondary sources on three (3) major aspects - land use, transport demand, and transport supply. Individual factors have been analysed in terms of their ability to influence transit and the contributing role in developing the current transit system. Results show that the main factor hindering the connectivity and sustainability of the transit system of Diego Martin is the residents’ travel behaviour ignited by the obsession with automobile ownership and usage, compounded by the poor quality and level of service of the transit service. The responses received from commuters indicate that improvements in the overall performance are not enough to shift ridership from

personal vehicles to transit usage. This paper provides recommendations with strategies that were derived from careful consideration of the current economic climate, as well as the culture and lifestyle of the residents of the Diego Martin communities.

III. Acknowledgements On behalf of the Association, we gratefully acknowledge all authors who have made this special issue possible with their research work. We greatly appreciate the voluntary contributions and unfailing support that our reviewers give to the Journal. Our reviewer panel is composed of academia, scientists, and practising engineers and professionals from industry as listed below: • Dr. Abrahams Mwasha; University of the West Indies

(UWI), Trinidad and Tobago, T&T • Dr. Carmen Riverol; UWI, T&T • Dr. Chris Maharaj; UWI, T&T • Dr. Cilla Benjamin; UWI, T&T • Professor Clive Davies; Massey University, New

Zealand • Dr. Donna A. Minott; UWI, Jamaica • Dr. Earl Edwards; UWI, T&T • Dr. Everson Peters; UWI, T&T • Professor Jeffery Jones; University of Warwick, UK • Dr. Ken D. Thomas; Auburn University, Auburn, USA • Professor Kit Fai Pun; UWI, T&T • Ms. Man-Yin R. Yiu; UWI, T&T • Dr. Michael Forde; UWI, T&T • Professor Peter Hogarth; Bournemouth University,

UK • Professor Richard Hobbs, University of Durham, UK

Finally, the views expressed in articles are those of the authors. This does not necessarily reflect the opinions or policy of the Association.

KIT FAI PUN, Editor-in-Chief Faculty of Engineering,

The University of the West Indies, St Augustine, Trinidad and Tobago

West Indies

CHRIS MAHARAJ, Guest Editor The Association of Professional Engineers

of Trinidad and Tobago, Port of Spain, Trinidad and Tobago,

West Indies

July 2017

K. Gobin and K. Louison An Android Application for Detection and Self-monitoring of the Diabetic Foot Ulcer

4

An Android Application for Detection and Self-monitoring of the Diabetic Foot Ulcer

Keri Gobina and Karen Louisonb,Ψ

Biomedical Engineering Unit, University of Trinidad and Tobago, O’Meara Campus, Trinidad and Tobago, West Indies; aE-mail: [email protected] bE-mail: [email protected]

Ψ - Corresponding Author (Received 21 October 2016; Revised 30 January 2017; Accepted 13 February 2017)

Abstract: Previous studies have already proven that thermal imaging can be a useful tool in the clinical management of the diabetic foot. This study aims to develop an accurate, easy-to-use, non-intrusive method for self-assessment of the diabetic foot. An affordable infra-red camera attachment for a mobile device allowed the acquisition of thermal and optical lower limb images from a small sample of healthy subjects and diabetic patients with foot ulcers. The data was then utilised in the design, development and testing of an Android application software prototype. Based on the findings, this Android application allows the input and recording of the patient’s required information, selection of thermal and optical images and then easy transmission of pertinent information via the method of choice to the designated clinician. This application is designed with the older or novice user in mind and should encourage the more regular home-monitoring of the diabetic foot ulcer necessary to reduce the severe effects of its complications. The work provides a novel method of utilising this promising technology in the provision of necessary telemedicine in Trinidad and Tobago.

Keywords: Diabetes mellitus, Foot Ulcer, App, Android, Telemedicine, Thermal Imaging, Monitoring 1. Introduction Diabetes mellitus and its complications are associated with substantial costs and loss of quality of life. In 2014, the global prevalence of diabetes in adults aged 18+ years was estimated to be 9% (WHO, 2015; Wild et al, 2004 ) The same report surmised that diabetes was the direct cause of 1.5 million deaths world-wide and projected that this disease will be the 7th leading cause of death by 2030. In Trinidad and Tobago, the 2011 National Risk Factor Survey (MOH, 2011) demonstrated the significant effect of diabetes and its complications on the population by its determinations that: i. Over 60% of all deaths in this country are due to

chronic non-communicable diseases including diabetes and its complications.

ii. 450 non-traumatic lower limb amputations occurred in people with diabetes in 2010.

iii. Patients with foot problems accounted for 14% of admissions and 29% of bed occupancy at public hospitals.

iv. 60% of persons who have lower limb amputations go into depression and 20% die within two years. For 2015, the number of diabetic cases in Trinidad

and Tobago was estimated to be approximately 140,000 patients (WHO, 2015; IDF, 2015), a figure considered grossly underestimated because of inefficiencies in data collection techniques (Nicholls, 2010). The same sources determined the cost per person in that year, both direct in terms of healthcare system expenditure and indirect in

terms of loss of earnings, disability payments, loss of time and other factors, to be some US$1,260.

The foot ulcer, as the most common complication of diabetes mellitus, is not therefore only a cause of severe disability, which often leads to lower limb amputation, but it can often result in significant physical, psycho-social and economic dysfunction. Additionally, a characteristic feature of this complication is that it is usually painless and therefore not easily subject to self-detection. A common misconception of patients with diabetic neuropathy is that ulceration would be accompanied by pain or that foot damage would be vascular in nature and accompanied by poor circulation and cold feet. There can be a false assurance that feet are healthy and a lack of adherence to recommended treatments. This can result in late detection and lead to difficulty of treatment.

Previous studies have found that diabetic foot ulcers can be preventable if detected early and given timely treatment (van Netten et al, 2013). Up to 85% of the foot-ulcer-caused amputations would be prevented (Wylie-Rosett et al, 1995). Early detection, however, depends on frequent assessment, which may be limited for a variety of reasons. Self-examination can be difficult or impossible due to the diabetic health impairment or be social impairment related (van Netten et al, 2013). Frequent examination by health care professionals could be too intrusive or costly and may also be limited by the subjective techniques employed, e.g. use of the human hand for assessment of inflammation-caused temperature

ISSN 1000 7924 The Journal of the Association of Professional Engineers of Trinidad and Tobago

Vol.45, No.1, July 2017, pp.4-10


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rises. At present, early effective management of these ulcers offers techniques which include education, blood sugar control, wound debridement, advanced dressing, offloading, advance therapies and, in some cases, surgery (Wounds International, 2013; Frykberg et al, 2006). These practices can reduce the severity of complications and improve overall quality of life of patients especially if a multidisciplinary team approach is employed (Yazdanpanah, 2015). Early detection and monitoring of the foot ulcer is therefore essential and emphasises the importance of frequent consistent self-assessment to the success of any treatment plan.

A method of hindering the development of the diabetic foot ulcer and reducing its harmful effects is therefore required. This must facilitate opportune diagnosis of the developing or present ulcer. Daily inspection by the patient or care-giver is often advised and regular detailed inspection by a physician during medical visits is also demanded. These examinations however usually provide only visual assessment or are based on subjective palpation. A non-invasive, quantitative method of examining the foot would increase the accuracy of ulcer detection and enhance its monitoring. It has been well investigated that areas that are likely to ulcerate, except for traumatic wounds, have been associated with increased local skin temperatures due to inflammation and enzymatic autolysis of tissue (DiPietro, 2010).

Early identification of these areas of inflammation would indicate regions of injury and would alert healthcare providers to the need for early treatment (Roback, 2010; Liu et al, 2013). There are, at present, many methods of investigating the skin ulcer, ranging from the relatively low cost methods of skin assessment, skin biopsy and Doppler ultrasound to the more expensive computerised tomography (CT) scans and phlebography (Labropoulos, 2009). Except for skin assessment, these methods are neither used for prediction of the development of an ulcer nor are concurrently low cost and non-invasive. The utilisation of thermographic techniques provides the opportunity of developing a method which is non-invasive, low-cost, and quantitative in nature.

Thermal imaging has already been shown to be a useful technique in the clinical management of the diabetic foot (Gatt et al 2015; Liu et al, 2013). Clinical studies were performed by (Lavery, 2004) successfully applying the measurement of infra-red radiation with a hand-held thermometer to determine plantar foot temperatures. They concluded that the disadvantages of low spatial resolution, the necessity for self-assessment and the lack of options for automatic analysis outweighed the advantage of this being a low cost technique. Technological advancements have, however, lessened these limitations. Infra-red detection attachments have been developed for mobile devices which are more affordable and easily available to the home user. The development of specialised applications for data collection and analysis on these mobile devices is also possible

through easily accessible web-based or other application developer programs. The tools are therefore available to create a non-invasive, reliable method of evaluating skin surface temperatures so as to provide a quantifiable measurement of inflammation which can then be used as a predictor of the development of an ulcer or for monitoring the present ulcer. Such a technique should encourage the daily self-assessment required of the patient and also enhance home-monitoring capabilities by allowing the transfer of required information to the healthcare provider.

This work will utilise a mobile device compatible infra-red detector attachment in the provision of an accurate, easy-to-use, non-intrusive method for self-assessment of the diabetic foot. Usage of an interconnected mobile device will allow ease of relay of thermal images and other pertinent information to the chosen clinician. Careful consideration of available technologies is necessary for determination of the attachment most apt for this process. The selected accessory will be utilised, in combination with a mobile device, in the development of a protocol for foot ulcer self-assessment. An easy-to-use Android application for a mobile device, with interface suitable to the typical user, is to be then created for the collection, storage and transmission of pertinent patient information to the healthcare provider. This work not only proposes a new method for home-monitoring of the diabetic patient with a present or developing foot ulcer but also allows and encourages the patient to play a greater role in the management of his or her own healthcare.

2. Method This preliminary study required acquisition of optical and thermal images, analysis of these images and the transmission of selected images to a designated receiver via a specialised mobile application. The selection of an accurate cost-effective infra-red detector which outputs sufficiently high resolution images in a format which enables automatic data analysis and ease of data transfer from one device to another was crucial to this project. It was also necessary that a suitable data acquisition protocol be defined (Hazenberg et al, 2014).

2.1 Selection of Thermal Imaging Device Of the thermal imaging devices available, the FLIR One Thermal Imaging attachment and the Seek Thermal: Infrared Thermal Imaging Camera were chosen for further evaluation because of their relative affordability and availability (FLIR, 2016). A variety of factors were considered and the results of this assessment are presented in Table 1.

Factors such as lower cost, ability to also acquire optical images, appropriateness of physical size and sensitivity, ease of use, compatibility to chosen mobile devices, sufficiently large temperature range and detection distance determined that the FLIR One Thermal Imaging Camera Attachment be chosen for this study.


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Table 1. A comparison of selected Thermal Camera attachments

Property FLIR ONE SEEK CompactPRO Name FLIR ONE Thermal Imaging Camera

(Attachment for Android) Thermal Imaging Camera (Made for Smartphones)

Manufacturer FLIR Seek Thermal Inc. Cost $ 249.99 US $499.00 US Dimensions 2.8 inches (72mm) × 1 inch (26mm) × 0.7 inches

(18mm) 1 x 1.75 x 1 inches

Mass 29 grams (~1oz) .5 ounces Resolution 120 x 120 pixels 320 x 240 pixels 76,800 pixels) Temperature Range -4°F to 248°F (-20° to 120°C) -40°F to 626°F Thermal Sensitivity 0.18° F (0.1° C) < 70 mK Field of view - 32-degree field of view Detection distance Up to 100 feet 6 inches to 1,800 feet User Interface Mobile App Free Seek Thermal Mobile App

2.2 Choice of Data Analysis Tool The accompanying FLIR Tools+ analysis software can be utilised for capturing, recording and analysis of thermal images (FLIR, 2016). It also allows editing of radiometric images, changing of palettes and adjustment of emissivity and reflective temperature parameters. This proved sufficient for the initial thermogram analysis.

2.3 The Data Collection Protocol The pilot study required only a small population sample size. The initial group of subjects included 1 healthy volunteer and 5 diabetic subjects aged between 21 and 90 years. A healthy subject was chosen who had no history of diabetes or complications of this disease, no pathological conditions or other causes of ill-health and no history of serious injury or surgery to the foot. Criteria for selection of the diabetic subjects included being presently under the care of a physician, having a present diabetic ulcer and having had no amputated foot regions. All subjects provided written informed consent before participation.

The data collection process began with an acclimatisation of the patient to the temperature of the room (maintained at 22℃) for the duration of the data collection session. Resting for a period of time in the examination room with its relatively low humidity and controlled temperature allowed the subject to achieve equilibration body temperature with the ambient temperature. To further minimise variables which would affect temperature measurement, patients were removed from contact with hot or cold sources, placed away from convection currents and a minimum number of persons allowed in the room at any time (Bagavathiappan, et al., 2009). Patients with ulcers on the ankle, upper foot surface or sole of the foot were asked to lie in a supine position for 10 minutes. Patients with ulcers above the ankle were seated with their feet planted on the floor for the same period of time. The advantage of the chosen postures over that of a standing position lay in the lack of any further required adjustment to position/ posture for

the generally older subjects during the combined patient resting and data collection period.

The camera, with attachment in position and mounted on a stand of fixed height, was placed a horizontal distance of 1 m from the ulcer. The placement distance is equivalent to that used in some previous studies (Bagavathiappan, et al., 2009). It allows the imaging of the entire region under analysis and would indicate, if possible, any alternative causes of temperature difference. The camera resolution, thermal sensitivity and detection distance allowed by use of the FLIR camera enabled acquisition of thermograms sufficiently detailed for use in this work. The camera parameters as set for image acquisition are provided in Table 2.

Table 2. Set Camera parameters during image acquisition Parameter Set Value Emissivity 0.98 Refl. Temp. 20.00oC Distance 1.00 m Relative humidity 50.00% Atmospheric Temperature 20.00oC Transmission 0.94 IR window temp 20.00oC IR window trans. 1.00

Additionally, studies by various researchers (Steketee, 1973; Bagavathiappan, et al., 2009; Chaves, et al., 2015) have indicated that with the skin being an almost perfect blackbody with an emissivity of 0.98 (Farid, et al., 2012; Bernard et al, 2013), the effect of ambient light and any variance in emissivity of normal and ulcerated skin is negligible.

Ten optical and thermal images were taken of the ulcer and surrounding tissue. Thermal and optical images were then taken which included both feet. The acquired images were analysed as shown in Table 3. Temperature range and thermal symmetry difference were calculated using the following equations: • Temperature range


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= Maximum temperature – Minimum temperature (Eqn.1)

• Thermal symmetry difference = Temperature of left foot – Temperature of right foot (Eqn. 2)

A thermal symmetry difference of more than 2.2℃ has been shown to be an indicator of pathology (van Netten et al, 2014; Tkáová, 2011).

Table 3. Analysis techniques applied to acquired images Optical Images Infra-red Radiation Images Presence of visible ulcer

Presence of ulcer as indicated by measured temperature and colour

Presence of inflammation as indicated by measured temperature and colour

Maximum temperature within area displayed in image

Minimum temperature within area displayed in image

Temperature range within area displayed in image

Thermal symmetry difference 2.4 Design of the Mobile Application The flow diagram for the initial application design is shown in Figure 1. App Inventor, the open-source web-based visual blocks programming language for creation of Android applications, was then used to construct and compile the application software (MIT, 2015)

Figure 1. Initial Application flow chart 3. Results Optical and thermal images were acquired and analysed from 5 diabetic patients with prominent foot ulcers and

one healthy subject. Table 4 shows a comparison of optical and thermal images from diabetic patients with foot ulcers.

Table 3. A comparison of optical and thermal images from diabetic

patients with foot ulcers Subject Optical Image Infra-red radiation image

Discernible foot ulcer

Discernible foot ulcer

Discernible region of

inflammation Patient 1 Y Y Y Patient 2 Y N Y Patient 3 Y N Y Patient 4 Y Y Y Patient 5 Y N Y

Figure 2. Optical image from Patient 1

Figure 3. Thermal image from Patient 1

It can be determined from these results that ulcers

which are clearly visible in optical images are not always as easily discerned from the thermal image. Whilst the optical image quite distinctly gives information as to ulcer presence, location, size and state of tissue; the thermal image informs about regions of abnormal temperature and therefore indicates the presence of inflammation and regions of inflammation. In Patient 1, the location of the ulcer was clearly identifiable in the thermogram. These


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findings are corroborated by Figures 2 and 3 which show the optical and thermal images for Patient 1. The ulcer is discernible in both images.

A more detailed analysis of the thermograms is given in Table 5. It can be observed that maximum temperatures on the ulcerated feet are an average of 4.3 degrees higher than that on the healthy subject. In addition, the minimum temperature in the region of interest is approximately 2 degrees higher in two out of the 5 subjects. The temperature range observed is also significantly higher in four out of the five subjects. The ability to utilise the thermal image for indication of regions of inflammation is again supported.

Table 5. Temperature variations within the thermal images

Subject

Maximum temperature observed, ℃

Minimum Temperature observed , ℃

Temperature Range

Diabetic Patient 1 32.1 29.4 2.7 Diabetic Patient 2 34.4 29.9 4.5 Diabetic Patient 3 32.3 27.3 5.0 Diabetic Patient 4 32.8 26.5 6.3 Diabetic Patient 5 36.5 27.5 9.0 Healthy Patient 29.3 27.1 2.2

A mobile application was then designed using the Android platform. The patient interface was designed to provide an aesthetically pleasing and easy to use access suitable to the older patient or mobile device novice as shown in Figure 4. Simplicity of operation was one of the main goals.

Figure 4. Main patient interface screen

The Android application was designed with the following functions: i. Entering, editing and recording of patient identifying

information ii. Entering, editing and recording of clinician contact

information iii. Entering and recording of fourteen glucose levels

with their corresponding date of input and patient-submitted cause of any abnormality

iv. Access to graphical display of stored glucose levels and the submitted causes of abnormalities for patient or clinician review

v. Access to library of optical and thermal images for reviewing and transmission to designated receiver

vi. Access to various methods of transmitting data (via email, Dropbox, etc.).

4. Discussion This work provides a preliminary investigation into the utilisation of easily accessible mobile thermal imaging technology in the provision of necessary telemedicine. Researchers have already indicated the usefulness of thermography in the evaluation of ulcers (Chaves, et al., 2015) and have suggested the detection of a positive ulcer temperature gradient (over normal skin) as a predictor of healing and a negative ulcer temperature gradient as an indicator of possible later development of necrosis (Bagavathiappan, et al., 2009; Farid, et al., 2012). The capability of thermal imaging as a non-invasive viable detector of conditions not yet visible to the eye has also been touted.

The results obtained in this small initial study corroborated previous findings by showing that the presence of a foot ulcer, which is clearly discernible in the optical image, is also indicated by regions of higher temperature in the acquired thermal images. In this investigation, however, the thermograms were obtained using the mobile phone attachment device. The higher temperature is indicative of inflammation in the ulcerated and surrounding tissue and can be useful in not only ascertaining the occurrence of the ulcer but may also suggest the condition of this tissue and the region surrounding it.

Even without a comparison of optical and thermal image, there is still a clear difference in absolute temperature values when contrasted with those of the healthy sample. Maximum and/or minimum foot temperatures were at least 2℃ higher than those of the healthy foot in all the diabetic patients in this sample. The validity of using the mobile device acquired thermogram for monitoring the foot ulcer is therefore indicated by this small study. Such temperature increases can be easily detected by a thermal camera attachment of sufficient resolution.

Additionally, the occurrence of conditions where the temperature of the ulcerated region is lower than that of surrounding tissue can be used to flag the presence or development of tissue necrosis. The utilisation of an appropriate analytic algorithm and/or suitable colour palette design, within the accompanying application, could be sufficient to inform the patient and the clinician of his or her foot ulcer status and untoward developments.

The mobile application, consequentially developed in this study, provides the required simple-to operate patient interface, the patient access to self-monitoring


9

information and the ability to transmit data to a clinician for patient-monitoring. Functions available from the main screen enable the user to perform various functions in a few steps: i. Input and storage of patient identification

information, clinician contact information, glucose levels and causes of abnormal variations.

ii. Selection of thermal and optical images from the device gallery.

iii. Transmission of pertinent information to the designated clinician, via a formatted document, using the method of choice. A trial with mobile device savvy users saw quick and

easy grasp of the application and its functions. Further trials with the intended population will be required. This software, however, already has the advantages of simplicity, logical flow and low number of controls.

Its use is expected to: i. Provide an easy-to-use method of home-monitoring

of the diabetic patient by transmitting patient identification, glucose level information and foot ulcer images to the chosen clinician

ii. Enhance patient self-monitoring by recording, updating and displaying patient glucose levels over a chosen period

iii. Encourage the required regular patient self-monitoring of the development and healing of foot ulcers by allowing access to optical and infra-red images of the ulcerated foot. Future improvements to this application, to provide

automatic and improved image analysis, flagging of negative temperature gradients and multi-user access, will facilitate and enhance its use as a patient monitoring tool.

Continual assessment of individuals with diabetic foot ulcers is essential for alleviating the injury and for adjusting the treatment plan as required. Medical thermography, which provides a non-intrusive method of examination and allows the tracking of patients over a long period of time without any injurious effect, can prove to be a very useful tool. Combining these advantages with the technological capabilities of mobile devices can generate a technique which is accessible, affordable, allows real-time analysis and assessment. Additionally, recording of patient data over periods of time can prove to be a valuable source of information to clinicians when developing treatment plans. 5. Conclusion The intention of this study was to develop an easy-to-use Android application, which, when used in conjunction with an affordable thermal camera attachment for a mobile device, will allow acquisition of thermal and optical images of the ulcerated foot, recording of necessary patient information and transmission of all pertinent data to a designated clinician. Initial image analyses have supported the results of previous studies in

indicating the validity of using thermal images for detection of areas of inflammation. The accompanying Android application successfully fulfills the required functions and has delivered a novel technique for utilising state-of-the-art technology in the provision of necessary telemedicine services in Trinidad and Tobago. Acknowledgements: The authors thank both the Barrackpore Medical Center and the Tejasvi Medical Center for providing access to their patients and valuable advice about the data collection process for this study. Gratitude also goes to The University of Trinidad and Tobago and the Biomedical Engineering Unit at O’Meara, for providing the necessary tools and the encouragement required for this research. References: Bagavathiappan, S., Saravanan, T., Philip, J., Jayakumar, T.,

Baldev, R., Karunanithi, R., Panicker, T.M.R., Korath, M.P. and Jagadeesan, K. (2009), “Infrared thermal imaging for detection of peripheral vascular disorders”, Journal of Medical Physics, Vol.34, No.1, pp. 43-47.

Bernard, V., Staffa E., Mornstein V., Bourek A. (2013), “Infrared camera assessment of skin surface temperature: Effect of emissivity”, Physica Medica, Vol.29, No.6, pp.583-591

Chaves, M.E.A., da Silva, F.S., Soares, V.P.C., Ferreira, R.A.M., Gomes, F.S.L., de Andrade, R.M. and Pinotti, M. (2015), “Evaluation of healing of pressure ulcers through thermography: a preliminary study. Research on Biomedical Engineering”, Vol.31, No.1, pp. 3-9.

DiPietro, L.A. and Guo, S. (2010), “Factors affecting wound healing”, Journal of Dental Research, Vol.89, No.3 pp. 219-229.

Farid, K.J., Winkelman, C. and Jones, A.R. (2012), “Using temperature of pressure-related intact discolored areas of skin to detect deep tissue injury: An observational, retrospective, correlational study”, Ostomy Wound Management, Vol.58, No.8 pp. 20-31.

FLIR (2016), FLIR One, Accessed 21 October 2016 from: http://www.flir.com/flirone/content/?id=69420

Frykberg R.G.1., Armstrong, D.G., Driver, V.R., Giurini, J.M., Kravitz, S.R., Landsman, A.S., Lavery, L.A., Moore, J.C., Schuberth, J.M., Wukich, D.K., Andersen, C. and Vanore, J.V. (2006), “Revision: Diabetic foot disorders – A clinical practice guidelines”, The Journal of Foot and Ankle Surgery, Vol.45, No.5 Supplement, pp.1-66

Gatt, A., Formosa, C., Cassar, K., Camilleri, K.P., de Raffaele, C., Mizzi, A., Azzopardi, C., Mizzi, S., Falzon, O., Cristina, S. and Chockalingam, N. (2015), “Thermographic patterns of the upper and lower limbs: Baseline data”, International Journal of Vascular Medicine, Article ID 831369, 9 pages

Hazenberg, C.E., Netten, J.J. and Bus, S.G. (2014), “Assessment of signs of foot infection in diabetes patients using photographic foot imaging and infrared thermography”, Diabetes Technology and Therapeutics, Vol.16, No.6, pp.1-8

IDF (2015), International Diabetes Federation, Accessed 21 October 2016, from: https://www.idf.org/membership/nac/trinidad-and-tobago

Labropoulos, N and Spentzouris, G. (2009), “The evaluation of lower-extremity ulcers”, Seminars in Interventional Radiology, Vol.26, No.4, pp. 286-295.

Lavery, L.A., Higgins, K.R., Lanctot, D.R., Constantinides, G.P., Zamorano, R.G., Armstrong, D.G., Athanasiou K.A. and Agrawal, C.M. (2004), “Home monitoring of foot skin temperatures to prevent ulceration”, Diabetes Care, Vol..27,


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No.11, pp.2642-2647 Liu, C., van der Heijden, F., Klein, M.E., van Baal, J.G., Bus, S.A.

and van Netten, J.J. (2013), “Infrared Dermal Thermography on Diabetic Feet Soles to Predict Ulcerations: a Case Study”, Advanced Biomedical and Clinical Diagnostic Systems XI. Vol.8572, pp.1-9

MIT (2015), MIT App Inventor, Massachusetts Institute of Technology, Accessed 21 October 2016, from: http://appinventor.mit.edu/explore/

MOH (2011), World Diabetes Day, Ministry of Health Trinidad and Tobago, Accessed 21 October 2106, from: http://www.health.gov.tt/news/newsitem.aspx?id=298

Nicholls, K. (2010), “The diabetes epidemic in Trinidad and Tobago”, Blood Glucose Monitoring, Accessed 21 October 2016, from: http://www.pre-diabetes.com/medical/blood-glucose-monitoring/definition-euglycemia.html

Roback, K. (2010), “An overview of temperature monitoring devices for early detection of diabetic foot disorders”, Expert Review of Medical Devices, Vol.7, No.5 pp. 711-718.

Steketee, J. (1973), “Spectral emissivity of skin and pericardium”, Physics in Medicine and Biology, Vol.18, No.5, pp.686-694.

Tkáová, M., (2011), “Thermographic atlas of the human body”, Proceedings of the 15th International Conference on Intelligent Engineering Systems, Poprad Slovakia, June 23-25, pp 427-429

van Netten, J.J., van Baal, J.G., Liu, C., van der Heijden, F. and Bus, S.A. (2013), “Infrared thermal imaging for automated detection of diabetic foot complications”, Journal of Diabetes Science and Technology, Vol.7, No.5, pp.1122-1129

van Netten, J.J., Prijs, M., van Baal, J.G., Liu, C., van Der Heijden, F. and Bus, S.A. (2014), “Diagnostic values for skin temperature assessment to detect diabetes-related foot complication”, Diabetes Technology and Therapeutics, Vol.16, No.11, pp.714-721.

WHO (2015), Diabetes, World Health Organisation, Accessed 21 October 2016, from: http://www.who.int/mediacentre/factsheets/fs312/en/

Wild, S., Roglic, G., Green, A., Sicree, R. and King, H. (2004), “Global prevalence of diabetes: Estimates for the year 2000 and projections for 2030”, Diabetes Care, Vol.27, No.5, pp.1047-1053.

Wounds International (2013), International Best Practice - Best Practice Guidelines: Wound Management in Diabetic Foot Ulcers, Accessed 21 October 2016, from http://www.woundsinternational.com/best-practices/view/best-practice-guidelines-wound-management-in-diabetic-foot-ulcers

Wylie-Rosett, J., Walker, E.A., Shamoon, H., Engel, S., Basch, C. and Zybert, P. (1995), “Assessment of documented foot examinations for patients with diabetes in inner-city primary care clinics”, Archives of Family Medicine, Vol.4, No.1, pp. 46-50

Yazdanpanah, L., Nasiri, M. and Adarvishi, S. (2015), “Literature review on the management of diabetic foot ulcer”, World Journal of Diabetes, Vol.6, No.1, February, pp.. 37-53

Authors’ Biographical Notes: Keri Gobin is undergraduate student in Biomedical Engineering at The University of Trinidad and Tobago. She is interested in improving the quality of health for diabetic patients. More specifically, her work examines the concept of the practical applications of Thermography.

Karen Louison is Senior Instructor at the Biomedical Engineering Unit, University of Trinidad and Tobago, O’Meara Campus. Her research interests include assistive technology and other applications of rehabilitation engineering.

K. Tota-Maharaj et al.: Municipal Wastewater Treatment and Associated Bioenergy Generation Using Anaerobic Granular Bed Baffled Reactor

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Municipal Wastewater Treatment and Associated Bioenergy Generation Using Anaerobic Granular Bed Baffled Reactor

Kiran Tota-Maharaja,Ψ Joseph Akunnab and Denver Cheddiec

aFaculty of Engineering & Science, Department of Engineering Science, University of Greenwich, Medway Campus, Kent, United Kingdom; Email: [email protected]

bUrban Water Technology Centre, School of Science, Engineering & Technology, Abertay University, Dundee, Scotland, United Kingdom; Email: [email protected]

c Utilties Engineering Division, University of Trinidad and Tobago, Point Lisas Campus, Trinidad, West Indies. Email: [email protected] Ψ - Corresponding Author

(Received 25 October 2016; Revised 13 February 2017; Accepted 01 March 2017) Abstract: This study assesses a modified anaerobic granular bed baffled reactor (GRABBR) which was assessed for municipal wastewater treatment at high organic loading rates (chemical oxygen demand ≥ 1,100 mg/l) under varying temperatures. For the two mesophilic temperatures tested (37⁰C and 25⁰C) under steady state conditions, the removal of Chemical Oxygen Demand (COD) and Biochemical Oxygen Demand (BOD) was 80 to 90 %. At lower organic loadings, the reactor operated as a completely mixed system with most of the treatment occurring in the first two compartments. The GRABBR also showed very high solids retention with low effluent suspended solids concentration for all organic and hydraulic conditions. Applications of GRABBR as a single unit, two-phase treatment system could be an economical option reducing the cost to achieve similar treatment goals for high strength wastewaters. The findings of this research suggest that the application of GRABBR is suitable for the treatment of multiple pollutants present in wastewater where each compartment acts as a specialised treatment stage with biogas production. Keywords: Anaerobic baffled reactor, Bioenergy, Domestic wastewater treatment, Methane 1. Introduction Anaerobic digestion (AD) is a series of processes in which microorganisms break down biodegradable material in the absence of oxygen, used for industrial or domestic purposes to manage waste and/or to release energy (Speece, 1983; Pescod (1992). One of the advantages of anaerobic treatment is the production of methane (CH4) which could be used for energy production. Anaerobic processes are well suited for high strength wastewater and are able to stabilise water properties with little biomass production. During aerobic digestion, the oxidation process releases high energy which allows rapid growth of essential bacteria (an important stage for the degradation stage).

On the contrary, anaerobic process releases little energy as a result of slow microorganism growth. During the aerobic process organic pollutants are used for cells construction (a change of microbial form). The stabilisation of organic pollutants is better with anaerobic processes because organic matter is transformed in carbon dioxide and methane (Colleran et al., 1995; Siewhui et al., 2012). AD is a multi-step process, consisting of series and parallel biochemical reactions. It is begun with hydrolysis which transforms complex polymers (e.g., proteins, carbohydrates and lipids) into smaller complexes such as fatty acids, amino acids, sugars and alcohols (Barber and

Stuckey, 1999; Lier et al., 2008). It’s an important step which permits the formation of simpler substrates for subsequent step. The fermentation step follows hydrolysis (lier et al., 2008). Smaller complexes are transformed into intermediate by-products (fatty acid and alcohols) but can be directly transformed into the methanogens precursor (acetate, carbon dioxide and hydrogen).

Figure 1 illustrates the changes of organic matter (proteins, carbohydrates, lipids) via hydrolysis, fermentation, acetogenesis and methanogenesis (generation of bioenergy). Different routes could be taken by substrates during this step of the AD process (See Figure 1). The preferential pathway is the conversion process to acetate because it provides the fermenters with a high energy yield as well as supporting the direct methane precursor (lier et al., 2008). An acetogenis reaction allows the transformation of volatile fatty acid and alcohols which result in the production of acetate, hydrogen and carbon dioxide. The final step is the methanogenesis phase. During this step, some bacteria could transform carbon dioxide and hydrogen into methane and water (Eq.1) and other microorganisms aid in the breakdown of acetate into methane and carbon dioxide (Eq.2).

CO2 + 4 H2 → CH4 + 2H2O Eq.1 CH3COOH → CH4 + CO2 Eq.2


Vol.45, No.1, July 2017, pp.11-19


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Figure 1. Methane Fermentation Stages Source: After Miyamoto et al. (1997) and Lier et al. (2008)

According to Speece (1983), toxicity from the AD

process is referred to as an adverse effect, not necessarily lethal on bacteria metabolism which can impair bacteria functions. Some substances are toxic for the biochemical reaction even at low concentrations such as oxygen. Nevertheless, other substances can become toxic if concentrations are too high such as ammonia, heavy metals, volatile fatty acids (VFA) and sulphides (Akunna, and Clark,1999; Barber and Stuckey, 1999). Monitoring pH levels gives an indication if the methanogenic reaction is inhibited or disturbed. If the methanogenesis phase is overloaded, VFA will accumulate in the reactor leading to a decrease in pH levels. The accumulated VFA can result in methnogenic toxicity. If this toxicity increases, the bacteria functions can be impaired and the methanogenesis capacity exceeded. 2. Anaerobic Granular Bed Baffled Reactors The principles of an anaerobic granular bed baffled reactor (GRABBR) are based on a series of baffles between the inlet and the outlet, at the base of the reactor, wastewater passes through a sludge bed whereby microbes degrade organic loadings of various concentrations. The GRABBR produces low sludge and its performances permit having low hydraulic retention times (HRT). The wastewater treatment processes within GRABBR are really stable from hydraulic and organic shock loadings. Another significant benefit from GRABBR is its ability to separate acidogenesis and methanogenesis phases longitudinally. The GRABBR combines the advantages of a baffled reactor (phase separation) and of an upflow-anaerobic sludge bed reactor

(UASB) (Granular sludge with good settable properties) for improved the process efficiency. This study aims to assess the performance of the GRABBR reactor for the treatment of municipal wastewater for different mesophilic temperature conditions (37°C and 25°C).

The interest of running the GRABBR at lower temperatures can result in a reduction of the overall treatment cost (decrease in energy requirements). The performance of the GRABBR was measured at varying hydraulic retention times (HRT) ranging from 2 hours (h) to 24 h. Lower HRT can lead to an increasing methane yield of the reactor based on a reduction in size. The operation of this reactor occurs where wastewater is pumped to flow across a series of baffles between the inlet and outlet, forcing the water to pass over and under the baffles. In the bottom of the reactor, water passes through a sludge bed where bacteria could degrade organic matter (Barber and Stuckey, 1999). Anaerobic Baffled Reactors (ABR) have several advantages which include: simple designs, no mechanical mixing, inexpensive to construct and to operate and special gas separation channels are not required.

The reactor is constructed to produce little sludge and its performance permitting lower HRTs. The process is relatively stable from organic shocks, hydraulic shocks and toxic materials as stated previously. However the most significant benefit of the ABR reactor is its ability to separate the acidogenesis phase and methanogenesis phase longitudinally (Barber and Stuckey, 1999). This phase separation property, which makes ABR reactor unique, is suitable for the treatment of complex substrates and contributes to the stability of the process (Baloch and Akunna, 2002). The ABR is very efficient as a result of optimising environmental conditions for methanogens and acidogens due to this phase separation. The stability of the system is explained by the buffer properties of the acidogenic phase which protects the methanogenic phase (Baloch, 2009). Despite all these advantages, at short HRT, the ABR performance is relatively low. In this case, the loss of biomass could be an issue leading to poor wastewater treatment. To resolve this problem, it is preferable to use a biomass that is structurally stable and possess good settling characteristics (Baloch and Akunna, 2003).

The GRABBR is an ABR reactor with granular sludge. It combines the advantages of a baffled reactor (phase separation) and that of an Upflow Anaerobic Sludge Blanket (UASB) digestion reactor (Granular sludge with good settable properties) for improved process efficiency (Chong et al., 2012). Like the ABR, because of compartmentalisation, the GRABBR encourages phase separation with acidogens zone in the compartments closest to the inlet and a methanogens zone in compartments nearer to the outlet. If the metanogens phase is granular, the acidogens phase is mostly non-granular. The GRABBR generally shows a very high solid retention rate because of this phase separation with


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granular sludge in the last compartments (Akunna and Clark, 1999; Muhammad et al., 2011). Furthermore, Akunna and Baloch (2003) found that the higher the organic load rate (OLR) the more stable the treatment becomes with an increased number of compartments involved. At low OLRs (up to 5kg COD/m3/day), a single compartment is necessary for a complete wastewater treatment.

Moreover, Baloch and Akunna (2008) led a study on the granular sludge and its structure based on the performance of a GRABBR. A multi-layered structure and a vast diversity of microorganisms carracterized these granules within the sludge. The core of the grannular sludge was composed in its largely part of Methanoseta-like celles. According to (Baloch, 2009), this bacteria play a key-role in the formation of the granules, as well as environmental factors such as temperature, pH, wastewater origin and the avaibility of nutrients. Furthemore, minerals (calcium, iron, potassium, phosphorus, sulphur, magnesium and sodium) play an important part and a key-role in the stabilisation of these granules.

As stated previously, the GRABBR encourages seperation phases. Additionally, in the acidogenic zone, granular sludge is disintegrated and the formation of a non-granular microbial mass, widely composed by gram negative Klebsilla pneumonia was observed (Baloch and Akunna, 2003). In the methanogenic phase, the granules were found to be relatively stable with a regular surface. On the other hand, in the acidogenic compartment,

granules showed broken parts and fissured surfaces. The presence of bacteriophage could explain this disintegration of the granular sludge in the acidogenic phase (Baloch, et al., 2008). Granular sludge are less sensitive to substrate inhibition and oxygen toxicity than non-granular sludge which explain, partly, the improvement of performance of the GRABBR reactor in comparison with ABR (Baloch, 2009). 3. Material and Methods 3.1 The Granular Bed Baffled Reactor The Granular Bed Baffled Reactor (GRABR) used in this study was a rectangular shaped bench-scale system. The reactor was divided in five equal compartments. A gap in the top of the baffle allowed wastewater to flow from one compartment to the other. Every compartment was divided in two parts due to a hanging vertical baffle angled at 45° at the base (see Figure 2). Three sampling ports were located in each compartment for liquid and gas collection and analysis. A second tray surrounded three sides of reactor with circulation of heated water, controlling the temperatures. American standard methods procedures were followed for analytical procedures and water quality analysis (APHA, 1992; Hach Company, 2002). Tables 1 and 2 show the design parameters of the laboratory pilot-scale GRABBR, and the equipment used for GRABBR water and energy resource recovery facility at pilot-scale, respectively.

Figure 2: Schematic Diagram of Granular Bed Baffled Reactor (GRABBR) with Five Compartments

Gas collection Taps

Sampling ports

Warm Water Jacket

Hanging Baffle

Standing Baffle

Granular Sludge Bed (Inoculum)


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Table 1. Laboratory Pilot-Scale GRABBR Reactor Design Parameters

Parameter Value Reactor dimensions (cm) 50 × 12 × 31 Working Volume (Litres) 10 Number of compartments 5 Number of sampling ports per compartment 3 Depth of feed in the reactor (cm) 6 Thickness of standing baffle (cm) 1.2 Thickness of hanging baffle (cm) 0.6

Table 2. Equipment Used for GRABBR Water and Energy Resource Recovery Facility at Pilot-scale

Device Brand Model Location/ Country

Air pump Interpret Avmini evolution Surrey, UK

Peristaltic pump

Cole-Pamer

Masterflex L/S Model 77200-50 Barrington, USA

Thermometer ATP TK 260 Leicestershire, UK

Heating pump Fisher scientific Isotemp Loughborough,

UK

A peristaltic pump (Masterflex L/S) was used to pump the wastewater and sewage through the reactor and the effluent is collected in a small cistern. An air pump (Interpret) kept a high oxygen rate in the influent sewage tank (see Figure 3). The temperatures of each compartment and tank were checked periodically with a thermometer (ATP) using a probe in each compartment of the reactor. During the experimentation, temperatures of the reactor were raised to 25°C or 37°C, respectively. A Heating pump (Fisher scientific) boiled water in a nearby storage tank and circulated this water in the reactor’s jacket. The wastewater treatment process was a closed-circuit, thus, the hot water which heats the GRABBR up to 25°C or 37°C returns into in separate hot water storage tank (see Figures 2 and 3). The reactor was seeded with anaerobic granular sludge obtained from Hatton Wastewater Treatment Works, Arbroath, Scotland, UK. At the beginning of the experiments, the COD was at 1448 mg/L.

3.2 Water Resource and Energy Recovery Pilot Plant

Operational Strategy The active volume of the reactor is 10 litres. At an operating speed 1, the pumping flow rates were 1.6 x 10-3 L.s-1. Therefore, the pump required 2 hours 45 minutes to refill all the volume of the reactor. A hydraulic retention time (HRT) of 24 hours was required for the initial experiments. Therefore, we need to distribute the 2h 45mins of pumping time during 24 hours. The effluent flow which comes from wastewater treatment works, is not regular throughout the day. Between 7 am and 9am and between 7 and 9 pm, the flowrate is the highest when compared to the rest of the day.

Figure 3. Wastewater Treatment Pilot Plant (water resource and energy recovery facility) using GRABBR Experimental Setup

In order to replicate these flow conditions and differences, the pumping time was doubled during the peak flow periods. Thus, the day was segmented into 5 periods, 2 for high flowrates and 3 for low flowrates. The pumping time was distributed in this way: 21 minutes per low flow rate periods, and 42 minutes per high flow rate periods. A timer allowed us to distribute the pumping time in ten periods (see Table 3).

Table 3. Pumping time distribution

Program Start End Day period Flow rate

1 0:00 am 0:04 am

0:00 am - 7:00 am Low

2 1:24 am 1:28 am 3 2:48 am 2:52 am 4 4:12 am 4:16 am 5 5:36 am 5:41am 6 7:15 am 7:25 am

7:00 am – 9:00 am High 7 7:45 am 7:56 am

8 8:15 am 8:26 am 9 8:45 am 8:55 am

10 10:00 am 10:04 am

9:00 am – 5:00 pm Low

11 11:30 am 11:34 am 12 1:00 pm 1:05 pm 13 2:30 pm 2:34 pm 14 4:00 pm 4:04 pm 15 5:15 pm 5:25 pm

5:00 pm – 7:00 pm High 16 5:45 pm 5:56 pm

17 6:15 pm 6:26 pm 18 6:45 pm 6:55 pm 19 8:50 pm 9:00 pm 7:00 pm –

12:00am Low 20 10:40 pm 10:51 pm


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3.3 Municipal Wastewater Characteristics and Inoculums

The wastewater used for the experimentation was collected from municipal wastewater treatment plants which came from Haton wastewater treatment works and Guardbridge wastewater treatment works, Fife, Scotland, UK. Samples were collected twice weekly just after the screening process (see Table 4). 3.4 Analytical Methods 3.4.1 pH The pH values of samples were measured using a 240 Corning pH meter (Orian model 420A with auto temperature compensation probe). The pH meter was calibrated by a pH 7.00 and 4.00 buffer regularly. 3.4.2 Chemical Oxygen Demand (COD) The COD was measured with a colorimetric method using a direct reading DR 5000 Hatch Lange spectrophotometer (Hatch, Loveland, USA) as described in Hach (2002). A cuvette test (Hach Lange, model LCK 514 and LCK 314) was used for more precision. With this test, oxidizable substances react with sulphuric acid-potassium dichromate solution in the presence of silver sulphate. Chloride is masked by mercury sulphate. The green coloration of Cr3+ is evaluated. 3.4.3 Biological Oxygen Demand (BOD) at 5 day and

20°C To measure BOD, samples required high dilution. In this way, oxygen isn’t a limiting reagent. Distilled water was used for the required dilution and sample preparation. Four solutions were added at the concentration of 1 ml per litre of distilled water: calcium chloride solution, a phosphate buffer, a magnesium sulphate solution and a ferric chloride solution. One ml of allylthiourea solution is added to inhibit the nitrification. Distilled water is saturated in oxygen with an air pump. In the laboratory, flasks used have a volume of 275 ml, thus the dilution factors F selected were 1/275, 3/275, 1/55, 10/275 and 15/275. The oxygen rate was measured before the flasks that are placed an incubator at 20°C during 5 days: it gives the T0 reading (Eq.3).

BOD measurements were made with a Hatch LDO oxymeter (model HQ30d flexi). Five days after, the

oxygen rate is once again measured: it is the T5 reading (Eq. 3). Two blank tests were made to make more accurate BOD reading and eliminate errors from the BOD result. The following equation was used to measure the BOD. The final BOD was computed by averaging the different BOD dilutions for the same sample.

BOD5 = F(T0 – T5) – (F - 1)(D0 – D5) Eq.3 where

BOD5 = Biological Oxygen Defend at 5th day F = Dilution Factor T0 = Oxygen rate in the sample at Day 0 T5 = Oxygen rate in the sample at Day 5 D0 = Oxygen rate in Blank at Day 0 D5 = Oxygen rate in Blank at Day 5

3.4.4 Gas analysis A gas analyser (Geothermical instruments, Model GA2000, Leamington Spa, Warwickshire, UK) was used to measure the composition of biogases formed by the anaerobic reaction in the reactor. CO2, CH4 and O2 were measured in percentage of the total composition and H2S and CO were measured in parts per million (ppm). The Guardbridge wastewater influent was on average a higher strength waste stream when compared to that of the Hatton inflow. The Guardbridge average COD was 759 mg/L approximately three times as high as the Hatton COD inflow (244 mg/L). Similarly, the Hatton total suspended solids (TSS) were twice as low when compared to the influent wastewater from Gauardbridge wastewater treatment works.

4. Results and Discussion 4.1 Chemical Oxygen Demand (COD) and Biochemical

Oxygen Demand (BOD) Removal For the two mesophilic temperatures evaluated (37⁰C and 25°C) under steady state conditions the GRABBR had good performances for the treatment of low-strength municipal wastewaters with high solid content. The removal of BOD and COD ranged from 80 to 90 %. For an HRT of 2 days, a temperature at 37°C and a BOD influent at 1,755 mg/L, the BOD removal was approximately 90%. Throughout the analysis the pH of the effluent remained stable between 7 and 7.5 for all organic loading rates (OLR).

Table 4. Influent municipal wastewater composition for pH, Chemical oxygen demand (COD), Biochemical oxygen demand (BOD) and Total suspended solids (TSS) for Haton wastewater treatment works and Guardbridge wastewater treatment works, Scotland, UK

Sample number n = 70 and period of analysis (January 2014 – August 2014) Parameters Mean Concentrations Standard Deviation Minimum Maximum pH 7.54 [7.22] 0.18 [0.15] 6.86 [6.89] 7.83 [7.74] Chemical oxygen demand (COD) mg/l 244 [770] 98 [193] 170 [653] 360 [1200]

Biochemical oxygen demand (BOD) mg/l 106 [290] 46.4 [87.6] 70 [180] 200 [516]

Total suspended solids (mg/l) 27 [55] 14.8 [13.3] 11 [21] 46 [62]


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Figure 4 shows an average measure of BOD and COD in each compartment of the GRABBR with Hatton and Guard Bridge Wastewater Influents, respectively. At lower organic loadings, the anaerobic reactor operated as a completely mixed system with most of the treatment occurring in the first two compartments. Temperatures at 25°C (not optimal temperatures for anaerobic reactions), with an HRT of 24 hrs, the BOD, COD and TSS removal were well within the EC Urban Waste Water Treatment Directive discharge standards (BOD < 25 mg/l ; COD < 125 mg/l). At both temperatures, the reduction of the HRT showed a good resilience on the water treatment performance of the reactor until the HRT dropped below 2 hrs. A 0.89 Organic Loading Rate (kg.COD/m3/day) with a HRT of 24 hrs gave an equivalent to 94% COD Removal and 98% BOD removal rates respectively from the mean inflow sewage and wastewater collected. The production of methane remained relatively low in all segments of the GRABBR throughout the experiments. The volume of CH4 produced was around 10-20 mL in the entire reactor even thou the COD removal increased significantly from 10 to 100 g/day.

Figure 4. Average measure of (a) BOD and (b) COD in each compartment of the GRABBR with Hatton and Guard Bridge

Wastewater Influents, with a HRT of 24 hrs. Sample number n = 70 and period of analysis (January 2014 – August 2014)

For this project, the influent for all waste streams was collected weekly from a wastewater treatment plant. Consequently, the characteristics of the inflow are variable due to the variability of the human activities or the weather (higher or lower levels of precipitation). Thus, the ORL did not increase linearly with the HRT decreasing. It is particularly clear when the HRT varies from 24 hrs to 18 hrs and the ORL remains nearly the same, or when the HRT ranges from 6 hrs to 2 hrs, the OLR increases by a factor of 5 during this time. Nevertheless, the OLR increases along all the experiments. Thus, the comparisons with the different HRT are important to the study. Figure 5 shows the increase of the COD in the compartments of the GRABBR during the experiments.

On two occasions, the COD measured of some compartments exceeded 125 mg/L the maximum concentration in COD according to European standard discharge. With a HRT of 2 hrs, the COD measured of the last compartment exceeded the standard discharge only once. More measures would be necessary to make a sound conclusion on its performance, but the overall performance of the GRABBR seems to be very efficient when the HRT is at 2 hrs with respect to the standard discharge requirements. Furthermore, the COD measures of the different compartments were not significantly different (p >0.05). Despite an increase of the ORL, the most part of the COD removal took place in the first compartment of the reactor. Table 5 shows the COD and BOD removal in relation to the Hydraulic Retention time (HRT) and the Organic Loading Rates (OLR).

Figure 5. Chemical oxygen demand (COD) and biochemical oxygen

demand (BOD) removal rates, organic loading rates (ORL) and decreasing hydraulic retention times (HRT) from 24 hrs to 2 hrs.

4.2 Biogas Production and Composition The GRABBR in previous studies have good performances for the treatment of high strength wastewaters with high solid content like brewage processing waters (Baloch and Akunna, 2003). The treatment of brewery wastewater with a GRABBR

(a)

(b)


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Table 5. COD and BOD removal in relation to the Hydraulic Retention time (HRT) and the Organic Loading Rates (OLR) Wastewater OLR (Kg.COD/m3/d) HRT (hr) COD removal (%) BOD Removal (%)

Hatton WWT 0.24 24 88 95

Guardbridge WWTW 0.89 24 94 98 0.87 18 92 98 1.33 12 88 90 2.20 6 85 95 12.7 2 82 91

consisting of 10 compartments showed a good removal efficiency of organic matter. The removal of BOD and COD ranged between 80% and 90% (Akunna and Clark, 1999). For an HRT at 2 days, a temperature at 37°C and a BOD Influent at 3,755 mg/L, studies by Baloch and Akunna (2003) and Akunna and Clark (1999) found a mean BOD removal of 90%. Furthermore, for varying GRABBR assessment, research conducted by Akunna and Clark (1999), Baloch and Akunna (2003) and Baloch, et al. (2007), found the pH of the effluent to be very stable between 7 and 7.5 for any OLR. Furthermore, Akunna and Baloch (2003) showed a high production of methane in the GRABBR: around 60% for an OLR from 20kg de COD.m-3.d-1 at a temperature of 35°C. In another study, the methane composition was found to range between 62% and 75% for on ORL between 2.16 and 13.38 kg COD.m-3.d-1 and a temperature at 35°C. The GRABBR inflow feed was brewery wastewater for those studies (Baloch et al., 2007).

The production of methane remained low during all the experiment. The volume of CH4 produced remained stable around 10 mL in the entire reactor even though the COD removal increases significantly from 10 to 100 g/day. Figure 6 shows the average composition of CO2, CH4 and O2 in each compartment of the GRABBR.

Figure 6. Average composition of CO2, CH4 and O2 in each compartment of the GRABBR

Most of the COD removal took place in the first

compartments where the acidogenesis phase prevails. The

wastewater passing through the last compartments, where the methanogenesis takes place, has a lower concentration of organic matter which limits the production of methane. This hypothesis could explain the decrease of the methane production. The COD removal rates increases as the wastewater flows across the reactor but with little effect or change for the removal rates regarding the last two compartments where the methanogenesis phase occurs. Mathematically, the methane production decreases whilst the reaction stabilises as shown from the volume of CH4 produced. The COD removal in compartments 3, 4 and 5 were not significantly different from each other throughout the experiments.

Figure 7. Percentage of methane (CH4) present in gaseous zone within chamber and water temperature fluctuations between 25 to

40°C for compartments 1 and 5.

Furthermore, the decreasing of the HRT led to a

reduction in time for the influent to be heated (25 °C or 35 °C) in the reactor as a result of the hot water circulating the GRABBR via the warm-water jacket. Thus, the temperature in the reactor decreases slowly with the reduction of the HRT even if the hot water in the jacket stays stable at 50 °C. Nevertheless, the temperature has a direct effect on the performance of the methanogenesis phase. The reduction of the temperature (operating at 25°C or lower) could explain the reduction in overall methane yield.


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Table 5. Specific Methane (CH4) yield and relative Hydraulic Retention Time (HRT)

HRT (hr) Average of total volume of CH4 in the reactor (L)

Average of COD removal (g/day)

Specific Methane yield (L/g.COD removed)

24 9.6 × 10-3 7.9 1.2 × 10-3 18 6.7 × 10-3 7.4 9.0 × 10-4 12 10.3 × 10-3 11.2 9.2 × 10-4 6 12.2 × 10-3 16.5 7.4 × 10-4 2 9.4 × 10-3 106.9 8.7 × 10-5

4. Conclusion For the treatment of the municipal wastewater, the GRABBR shows excellent performance for the reduction of COD, BOD, and TSS. Even at lower mesophilic temperatures (i.e., 25°C) which is not an optimal AD operational temperature for the anaerobic reaction, and a HRT of 24 hours, the BOD, COD and TSS removal rates were well within the European wastewater treatment standard discharge regulations. At 35°C, the reduction of the HRT showed a good resiliency with respect to the performance of the reactor until the HRT drops below 2h. Nevertheless the good performance of the GRABBR for the removal of wastewater pollutants and the production of methane is one of the most interesting research areas of AD processes.

Recommendations for future research include ensuring that the reactor performs over a longer period of time to consolidate the performance and results for varying wastewater inflows. Measuring of VFS is important to assess the AD reaction and treatment performance in addition to understanding the reasoning behind lower production of methane. An improved temperature control of the reactor is needed, which allows better heat exchange between the hot water tank and the GRABBR improving the thermic exchanges between the jacket and the core of the reactor.

Insulating materials would not aid in the anaerobic process for the reactor. Heating the influent in order for the mesophlic bio-digestion phase to occur between 20°C and about 40°C, typically 37°C is most optimal to produce biogas, biofertilisers and sanitarisation mainly in tropical countries such as the Caribbean. Acknowledgements: The Authors are grateful to Dorian Fontanilles from The National Polytechnic Institute of Toulouse, France, School of Agricultural and Life Sciences (Ecole Nationale Supérieure Agronomique de Toulouse), for his technical assistance and support. Financial support was provided by the Urban Water Technology Centre (UWTC), University of Abertay Dundee, United Kingdom. References: Akunna, J. and Clark, M. (1999), “Performance of a granular-bed

anaerobic baffled reactor (GRABBR) treating whisky distillery wastewater”, Bioresource Technology, Vol 74, pp. 257 - 261.

APHA (1992), Standard Methods for Examination Water and Wastewater, 18th Edition, American Public Health Association,

Washington D.C., USA Baloch, M. (2009), “Methanogenic granular sludge as a seed in an

anaerobic baffled reactor”, Water and Environment Journal, Vol 25, pp.171 - 180.

Baloch, M. and Akunna, J. (2002), “Effects of rapid hydraulic shock loads on performance of GRABBR”, Environmental Technology, Vol 24, pp. 361-368.

Baloch, M. I. and Akunna, J. (2003), “Granular bed baffled reactor (GRABBR): Solution to a two-phases anaerobic digestion system”. Journal of Environmental Engineering, Vol 129, No.11, pp.1015-1021.

Baloch, M., Akunna, J. and Collier, P. (2007), “The performance of a phase separated granular bed bioreactor treating brewery wastewater”, Bioresource Technology, Vol.98, pp. 1849 - 1855.

Baloch, M., Akunna, J., Kierans, M. and Collier, P. (2008), “Structural analysis of anaerobic granules in a phase separated reactor by electron microscopy”, Bioresource Technology, Vol.99, pp.922-929.

Barber, W. P. and Stuckey, D.C. (1999), “The use of the anaerobic baffled reactor (ABR) for wastewater treatment: A review”, Water Research, Vol 33, No.7, pp.1559-1578.

Chong, S., Sen, T.K., Kayaalp, A. and Ang, H.M. (2012), “The performance enhancements of upflow anaerobic sludge blanket (UASB) reactors for domestic sludge treatment: A state-of-the-art review”, Water Research, Vol 46, No.11, pp 3434-3470.

Colleran, E., Finnegan, S. and and Lens, P. (1995), “Anaerobic treatment of sulphate containing waste stream”, Water Science and Technology, Vol.19, pp.117-126.

Hach Company (2002), Water Analysis Handbook, 2nd edition, Loveland, Colorado, USA

Lier, J.B.V., Mahmoud, N. and Zeeman, G. (2008), Biological Wastewater Treatment: Principles, Modelling, Design, Chapter 16 Anaerobic treatment, Cambridge University Press, Cambridge

Miyamoto, K. (1997), “Renewable biological systems for alternative sustainable energy production”, FAO Agricultural Services Bulletin, No.128, Osaka University, Osaka, Japan

Muhammad, A.L., Rumana, G., Zularisal, A.W. and Anwar, A. (2011), “Integrated application of upflow anaerobic sludge blanket reactor for the treatment of wastewaters”, Water Research, Vol.45, pp.4638- 4699.

Pescod, M. (1992), “Wastewater treatment and use in agriculture”, FAO Irrigation and Drainage, Paper 47, Available online at: http://eprints.icrisat.ac.in/8638/ Accessed October 2016

Speece, R.E. (1983), “Anaerobic biotechnology for industrial wastewater treatment”, Environmental Science and Technology, Vol 17, No.9, pp.416A-427A.

Authors’ Biographical Notes: Kiran Tota-Maharaj is Senior Lecturer in Water and Environmental Engineering within the Department of Engineering Science at The University of Greenwich, UK. Dr Tota-Maharaj is a Chartered Engineer and a corporate member of the Society of Environmental Engineers, UK, a professional engineer through the Society of Professional Engineers, UK, a member of the American Society of Civil Engineers (ASCE), a member of The International


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Association for Hydro-Environment Engineering and Research (IAHR) and a fellow of the Higher Education academy, UK. He is the programme leader for the Masters of Science (MSc) in Water, Waste and Environmental Engineering at the University of Greenwich, and currently the first supervisor of five PhD projects in Water, Wastewater and Environmental Engineering funded by academia and industry. He is the author/co-author of over 50 peer-reviewed journal articles and conference papers.

Joseph Akunna is Professor of Water and Environmental Engineering and the Director of Postgraduate Environmental Engineering Education at The University of Abertay Dundee. Professor Akunna is also a Visiting Professor at Ecole Supérieure d’Ingénieurs des Travaux de la Construction, Cachan, France. He is an internationally recognised expert on anaerobic digestion (AD)

processes of food and agricultural residuals, including brewery and distillery effluents, for the production of biofuel, namely biogas (methane) and soil fertilisers.

Denver Cheddie holds a PhD in Mechanical Engineering, and has authored over 30 scientific papers. His specialty is modelling and simulation of engineering systems, with particular emphasis to fuel cells and renewable energy technologies. Dr. Cheddie serves as an Associate Professor in the Utilities (Integrated) Engineering department at The University of Trinidad and Tobago.

S. Maharaj et al.: Production of Plant Extracts by Supercritical Fluid Extraction

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Production of Plant Extracts by Supercritical Fluid Extraction

Sharad Maharaj a,Ψ, Marian J. Watson b, Rosemarie Skeenec and David R. McGaw d

a, dDepartment of Chemical Engineering, The University of the West Indies, St Augustine Campus, Trinidad and Tobago, West Indies; Emails: [email protected]; [email protected]

b,cThe University of Trinidad and Tobago, Trinidad and Tobago, West Indies; Emails: [email protected]; [email protected]

Ψ - Corresponding Author (Received 29 September 2016; Revised 13 February 2017; Accepted 08 March 2017)

Abstract: A case is presented for the introduction of a flexible commercial Supercritical Fluid Extraction (SFE) operation in Trinidad and Tobago (T&T), whereby waste carbon dioxide from the ammonia industry is used to extract high value products from indigenous plant materials. Typical raw materials would be waste products from food processing such as orange peel and pumpkin seeds, as well as crops which are, or could be, grown locally such as turmeric, hot peppers, ylang ylang and vetiver. New crops could utilise land formerly used for sugar cane or could be supplied from contract farmers. Background research on the extraction characteristics of most of the above potential raw materials has been carried out on bench scale SFE units at The University of the West Indies (UWI). Typical data for pumpkin seeds and ylang ylang is presented, giving extraction curves (% extraction with time), variation of total quantum of extraction with varying processing conditions (operating pressure and temperature), as well as product quality as evidenced by chromatographic analysis. The potential for producing both essential oil and oleoresin separately from turmeric in a single operation, by changing operating conditions during a run, is also presented. A flowsheet for the envisaged process is presented, with an order of magnitude estimate of the capital cost of an operation of a ‘3-extractor, 2-separator’ system being determined to be approximately US$7.5 million. By way of example, the economic feasibility of a plant to produce the extract of turmeric, being marketed at the current world price of US$50 per kg, on the basis of a 310 day per year operation with a 3-hour turn-around time gave an internal rate of return (IRR) of 21% on a 5-year projection. This demonstrated that such an operation could be commercially feasible and a Business Plan should be developed to move the concept forward.

Keywords: Essential oil, oleoresin, carbon dioxide, industry, feasibility, business plan 1. Introduction Many plant species in the tropics secrete complex chemicals which are extracted and incorporated into various consumer products which may be classified under the following headings:

• Food Flavours • Aromatherapy/Personal Care products • Nutraceuticals/Pharmaceuticals • Perfumes • Various uses e.g. security sprays, insecticides, dyes

and colourings There are two basic types of plant extracts, essential

oils and oleoresins. Essential oils are the volatile oils giving rise to the odour from the plant. Oleoresins, however, have much higher vapour pressure than the essential oils, boiling at higher temperatures. Grand View Research (2014) estimated the global essential oil market to be approximately US$5.5 billion in 2014. They stated that increasing essential oil penetration in aromatherapy, coupled with rising demand for fragrances and flavours in food and beverages, is expected to remain a key driving factor for the global market.

Growing consumer preference for natural products has led to the development of novel applications in

personal care and beauty products. Rapid industrialisation and growing disposable incomes, particularly in emerging economies such as China, India, Vietnam and Thailand, are some of the macro factors steering growth. In addition, rising application scope on account of growing consumer awareness regarding health benefits, and negligible side effects associated with the use of essential oils, is expected to spur their demand in the medical industry. Growing demand for aromatic flavours and fragrances in cosmetics, perfumes, as well as spa and relaxation applications is also expected to fuel demand in the coming years.

Specifically, Grand View Research (2016a) estimated that the United States (US) essential oil market revenue will double from ~US$2.0 billion in 2015 to more than US$4.0b in 2022, with breakdowns being given for the top 10 oils. The European market was valued at US$2.4b in 2014, but growth was expected to remain stagnant in that market. The Oleoresin market was estimated by Grand View Research (2016b) to be ~ US$1.14 billion in 2014, increasing to US$1.69 billion in 2022. Shifting consumer preferences towards natural ingredients over synthetic flavours is expected to have a positive impact on the market growth. Oleoresins are also widely used in


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treating cancer, stress and back pain owing to their antioxidant and anti-inflammatory properties which is expected to further stimulate its market development.

The Caribbean does have a long history of essential oil production, albeit limited in the range of products. Thus, bay oil has been produced in Dominica since the 19th century and lime oil was produced in a number of the islands for many years (Guenther, 1961). More recently, Pimento Oil production has been introduced in Jamaica, and Nutmeg Oil in Grenada, Anise Oil in Trinidad and Bay Oil in Tobago. Even though these industries are small by international standards, they have contributed significantly to the economy in the small islands of Dominica and Grenada. In the case of Trinidad and Tobago, Anise Oil was produced on old sugar lands at Orange Grove by the Pernod Company for some time before being closed down a few years ago. In addition, a Bay Oil facility was installed in Tobago in the 1970’s to exploit a mature bay tree plantation, but not operated continuously.

Traditionally, essential oils were extracted from the plant materials by steam distillation, whereas oleoresins were extracted by solvent extraction techniques. The more modern method of Supercritical Fluid Extraction (SFE) utilising carbon dioxide as the extraction fluid, however, has the capability of extracting both essential oils and oleoresins, giving rise to a high level of flexibility in operation. The work described in this paper compares SFE with the traditional extraction techniques and demonstrates that it could be used commercially in Trinidad and Tobago in the resuscitation of the industry. The timing of the introduction of the industry in Trinidad and Tobago is opportune, with the need to diversify the economy and the opportunity to exploit expanding global markets. 2. Extraction Technologies 2.1Traditional Technologies Until towards the end of the 20th century separate technologies had to be used to extract essential oils and oleoresins. Thus the extraction of essential oils utilised steam to vapourise the oil, the most common technique being steam distillation extraction (SDE). In the operation of steam distillation, the material to be extracted is charged into a basket, the basket being lifted into the distillation still where it sits on a perforated grid. The top lid is then clamped down and steam from the boiler is passed though the bed of material. The essential oil in the material vapourises and is carried off with the steam into the condenser where the oil/steam mixture condenses. This mixture then passes down into the separator where the oil and water separate by virtue of the immiscibility of the oil in the water, the oil floating on top of the water phase.

Oleoresins however are not volatile, so cannot be separated from the plant materials using steam distillation.

They are usually extracted by solvent extraction using a suitable liquid solvent which dissolves the oleoresin but not the matrix of the plant material. Various techniques have been used over the years, but typically the plant material is charged to a vessel containing the solvent e.g. ethanol. After a suitable period of time the vessel is discharged and the solvent with the oleoresin is separated from the spent plant matrix. The oleoresin is then subjected to distillation to separate the oleoresin from the solvent. The solvent is recycled for reuse. 2.2 Supercritical Fluid Extraction In the last decade of the 20th century, the concept of Supercritical Fluid Extraction was promoted as a viable and more flexible alternative to both Steam Distillation and Solvent Extraction. A typical flow sheet for a three- vessel, two-separator, commercial process is shown in Figure 1. The extraction is effected by passing carbon dioxide at high pressure and just above room temperature through a packed bed of the plant material charged to the extractors. The essential oil/oleoresin dissolves in the supercritical carbon dioxide and passes to one of the separators where the pressure is let down to release the extract. The carbon dioxide is then compressed back to extraction pressure and recycled back through the extractor. It is a batch process so that when operating, two of the units could be extracting whilst the third unit will be discharging and recharging. The extract is taken off the base of the separators.

The critical temperature and pressure for carbon dioxide is 31°C and 72.9 bar. Such units usually operate in the range 30°C to 70°C and up to 500bar pressure. The higher pressures will extract both essential oils and oleoresins as a mixture, but it is however possible to operate the system at just sub critical conditions to extract essential oils only. Figure 1. Flowsheet for Commercial Supercritical Fluid Extraction

System


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3. Comparison of SFE with SDE and Solvent Extraction

3.1 Steam Distillation Steam distillation has been well established as the process for extracting essential oils from plant materials for well over 100 years. The major disadvantages in its use are that it uses an elevated temperature of ~100°C with some potential temperature degradation of the extracted oils, and that distillation times are relatively long, usually up to 8 hours. 3.2 Solvent Extraction Solvent extraction is a complex process with more processing steps. Since a solvent is used to extract the oleoresin, the solvent/oleoresin mixture has to be separated by fractional distillation. This is not only expensive but it means that the oleoresin product will always be contaminated with the solvent. This can limit its use for food products. 3.3 Supercritical Fluid Extraction The major advantage of SFE is that it can extract both essential oils and oleoresins, making it much more flexible in a multiproduct environment. The process also operates at temperatures not much above ambient, so that the chemistry of the extracted product is not modified significantly by the process. Extraction times are also shorter than that using the traditional techniques. The major disadvantage is Capital Cost. It is much more expensive than Steam Distillation. 4. Supercritical Fluid Extraction Characteristics In order to provide background data towards the development of a commercial Supercritical Fluid Extraction industry in Trinidad and Tobago, laboratory scale SFE equipment has been installed and operated in the Extraction Laboratory of the Department of Chemical Engineering at The University of the West Indies (UWI), together with a GCMS to determine the chemical composition of the products from the extractions. The extraction characteristics of a large number of indigenous plant materials have been determined utilising a 100 ml extraction vessel, together with evaluations on the effects of the process variables on the extraction process e.g. Raw material size, Carbon dioxide pressure, temperature and flow rate. Typical results are presented in order to demonstrate the capabilities and flexibility of SFE. 4.1 Oleoresin from seeds/nuts Commercial products are extracted from seeds and from nuts mainly as cooking or salad oils, but also as health remedies. Pumpkin seed oil for instance is used as a dressing on salads, in marinades, breads, soups and snack foods (Patel, 2013) but is also incorporated into gel-

capsules to be used to treat prostate disorders (GNC Holdings, 2014). A typical extraction curve for pumpkin seeds (Sellier, 2016) carried out at 50°C and 250 bar is shown in Figure 2. Figure 2. Extraction Curve for Pumpkin Seeds – Temperature 50°C,

Pressure 250bar

Reference to Figure 2 shows that extraction was

essentially complete after about 3 hours. The samples were then treated to produce the fatty acid methyl esters (FAME) which were then analysed by way of Gas Chromatography (GC); the same procedure was then applied to a GNC™ pumpkin seed oil sample (GNC Holdings, 2014). Comparison of both chromatograms showed that the SFE oil samples had three major peaks in common with that of the GNC™ oil. While further work is required to identify, and quantify the components, these preliminary investigations suggest that the local oil may have the potential to be of comparable quality to that sold internationally. 4.2 Extraction from flowers High quality perfumes often utilise the extracts from tropical flowers in their bases. For example, the essential oil extracted from ylang ylang (Cananga odorata forma genuina) is the perfume base for Chanel #5 and is produced on islands in the Indian Ocean utilising steam distillation (The National World, 2015).

The more important flowers which can be grown locally are jasmine (Paltoo, 2002) and ylang ylang (Watson, 2005), for which extensive extraction investigations have been carried out at UWI. A typical series of extraction curves for ylang ylang as carried out by Watson (2005) is shown in Figure 3, with varying operating pressure from 100 bar to 450 bar at a temperature of 45ºC. Reference to Figure 3 shows the strong effect of operating pressure, with the quantum of


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extraction at 450 bar at 1.5% being almost 3 times that at 100 bar.

Figure 3. Effect of Operating Pressure on the Extraction of Ylang Ylang

The yield from SFE at the higher operating pressures was similar to that from steam distillation. However, the chemical compositions, when compared to Buccellato’s (1982) data, were found to be significantly higher in the less volatile compounds such as benzyl benzoate and benzyl salicylate. Similar observations were made when compared with the compositions reported by Michał Brokl (2013) for the volatile fraction of their extracts. These differences were expected since the SFE extracts’ compositions were being compared to those determined from steam distilled extracts. 4.3 Extraction from Root Crops A number of tropical species secrete essential oils and oleoresins in their roots. Typical examples are vetiver, where the essential oil is used in perfumery, and the spices turmeric and ginger where the extracts, which contain both essential oils and oleoresins, are used as food additives and for various medicinal treatments. Traditionally in order to extract both the essential oil and the oleoresin, milled turmeric has to be subjected to both steam distillation and solvent extraction. However, a process has been developed at UWI whereby dried ground turmeric is subjected to carbon dioxide extraction at two sets of conditions. Thus, the powder is first contacted with carbon dioxide under subcritical conditions whereby the essential oil is extracted but none of the oleoresin. After all the essential oil is extracted, the pressure is increased and the turmeric is subjected to supercritical fluid extraction, which then extracts the oleoresin.

Figure 4 shows the combined extraction curve where young oven-dried turmeric powder was subjected to 25°C and 65 bar pressure for 1 hour which initially extracted

the essential oil, seen to be approximately 5% of the original mass. The temperature and pressure were then increased to 50°C and 200 bar, respectively, for a further 2 hours during which the oleoresin was extracted. The final total extraction was 11.46%. The major components of the essential oil were ar-tumerone, curlone, α-tumerone, β-sesquiphellandrine, zingiberene and α-curcumene. The oleoresin normally contained between 50% and 60% curcumin (quantified by UV-VIS Spectroscopy), a compound that showed positive results in the treatment of patients with pre-cancerous changes in different organs; clinical trials of a directly injectable form of curcumin for cancer treatment are currently ongoing (Cancer Research UK, 2015).

Figure 4. Combined Extraction Curve for Young Oven-Dried Turmeric (YODT) – Subcritical (25°C and 65Bar) Followed by

Supercritical Fluid Extraction (50°C and 200 Bar)

4.4 Extraction from Leaves/Fruits Research on the extraction of essential oils from leaves has been carried out by Maharaj (2011) on basil, and by Clarke (2012) on bay leaves. The results on the extraction of bay oil from bay leaves have been published by McGaw, et al., (2016). In the work a direct comparison of SFE with steam distillation was made for the extraction of the essential oil from Bay (Pimenta racemosa) leaves. It was found that the quality components of bay oil were extracted by SFE in the first hour after which the extracts were increasingly contaminated with higher components and waxes. The maximum yield of the total oil extracted was approximately 4.0% at 40°C and 150 bar pressure. A similar yield was obtained using Steam Distillation but it took twice as long. The SFE extract however had higher concentrations of the quality, i.e. phenolic, components. Thus the eugenol content for the SFE extract was 62.0% compared to 51.4% for the SDE extract, and the chavicol component for the SFE extract was 26.3% compared to 23.0% for the SDE extract. It is appropriate to note that


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there is a bay tree plantation in Tobago which can be used to source the raw material.

Another prime candidate for commercial exploitation is that of hot peppers, the oleoresin from which contains capsaicin, used extensively for medicinal purposes for example, in treating arthritis (Arthritis Research UK, 2016), in pepper sprays and as a food flavouring. Experimental work by Holder (2007) has demonstrated that SFE is ideally suited for producing both the essential oil and the oleoresin. 5. Commercialisation of SFE in Trinidad and Tobago The market projections for growth in both the essential oil and oleoresins markets over the next 5 to 10 years are buoyant (Grand View Research, 2016a) (Grand View Research, 2016b), demonstrating an opportunity for Trinidad and Tobago to re-enter the business.

The experimental extraction results, detailed in Section 3 for seeds/nuts, flowers, root crops and leaves/fruits, have demonstrated the versatility of SFE as a process to extract valuable products from plant materials which can be grown nationally. The results have also shown that both essential oils and oleoresins can be produced by SFE even during a single run. In addition, the extraction rates are faster than steam distillation and the extract product quality is at least as good as steam distilled products.

It is therefore appropriate to review the prospect for commercialising SFE in Trinidad and Tobago by developing a techno-economic feasibility study. It is clear from the experimental results that technically the process has the flexibility to produce from a wide variety of materials at different times. In addition, when using a 3-extractor system as shown in Figure 1, it is even possible to extract from two materials at one time.

A feasibility study has therefore been carried out to see if such an operation could be economically viable. In carrying out the study, a 3-extractor system, similar to that shown in Figure 1, was considered, and to simplify the exercise a single raw material was assumed; that being turmeric.

Such systems are limited in size because of the operating pressure. A quotation for a 3 by 1,000 L extractor system utilising 2 separators was obtained from the major supplier of such systems in the USA, the supply of a skid mounted system being given as ~US$6.3m. Recognising that the turmeric has to be dried and milled prior to processing and that a building for raw material storage, processing, product store, laboratory and administration had to be built, the overall capital cost was estimated to be ~US$7.5 millions.

Supply of raw material was assumed to be from contract farmers at a factory gate price of US$0.60 per kg. The preferred method however would be to produce on land next to the factory site using mechanical methods to reduce cost.

Assuming that the plant would operate for 310 days in the year, a plant utilisation factor of 85% with a batch turnaround time (filling, extracting, discharging, recharging and down-time) of 3 hours it is estimated that 148,800 kg of extract would be produced annually. The current global price for turmeric extract is US$50 per kg, so the estimated annual revenue is US$7.44m.

With an annual operating cost estimated to be US$4.27m, the Internal Rate of Return over a 5-year projection was calculated to be 21%, thereby indicating that such a business could be financially viable. Carbon dioxide is readily available in Trinidad as a by-product of ammonia manufacture.

It was assumed in the feasibility that the extract would be marketed without further processing, and sold through brokers in the USA and Europe. It is envisaged that this would only be the first step in the development of the industry. The second stage would be the separation of the valuable components of the initial extract by fractional distillation. The valuable components could then be sold directly to the manufacturers of the consumer products at significantly higher prices. The third stage would be the development of specific consumer products for marketing locally, regionally and globally, thereby benefitting fully in the value added chain. 5. Conclusion It may be concluded that the introduction of a Supercritical Fluid Extraction Industry in Trinidad and Tobago would be viable technically and could also be financially viable. It is recommended that a complete Business Plan be developed and investors sought for the enterprise. References: Arthritis Research UK (2016), Capsaicin, Accessed September

2016, from: http://www.arthritisresearchuk.org/arthritis-information/complementary-and-alternative-medicines/cam-report/complementary-medicines-for-osteoarthritis/capsaicin.aspx

Buccellato, F., (1982), "Ylang ylang survey", Perfumer and Flavorist, August/September, Vol.7, pp.9-12.

Cancer Research UK, (2015), “Can turmeric prevent or treat cancer?” Accessed September 2016, from: http://www.cancerresearchuk.org/about-cancer/cancers-in-general/cancer-questions/can-turmeric-prevent-bowel-cancer

Clarke, W., (2012), Supercritical Extraction of West Indian Bay Oil, M.Sc. Dissertation (Unpublished), Department of Chemical Engineering, The University of the West Indies, Trinidad and Tobago

GNC Holdings, I., (2014), GNC Pumpkin Seed Oil 1000, Accessed September 2016, from: http://www.gnc.com/GNC-Pumpkin-Seed-Oil-1000/product.jsp?productId=2133389

Grand View Research (2016a), Essential Oil Market Analysis By Product (Orange, Corn Mint, Eucalyptus, Citronella, Peppermint, Lemon, Clove Leaf, Lime, Spearmint), By Application (Medical, Food and Beverage, Spa and Relaxation, Cleaning and Home) and Segment Forecasts to 2024, Grand View Research, Inc..

Grand View Research, (2016b), Oleoresin Market Analysis By Product (Paprika, Black Pepper, Capsicum, Turmeric, Ginger,


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Garlic, Onion), By Application (Food and Beverage, Flavors, Pharmaceuticals) and Segment Forecasts to 2024, Grand View Research, Inc.

Guenther, E. (1961), The Essential Oils, Volume 1, Van Nostrand Company Inc., New York

Holder, R., (2007), Processing Potential of the Capsicum Genus, Ph.D Thesis in Food Technology (Unpublished), Department of Chemical Engineering, The University of the West Indies, Trinidad and Tobago

Maharaj, S. (2011), Extraction Studies with Basil, Ph.D. in Chemical Engineering (Unpublished), Department of Chemical Engineering, The University of the West Indies, Trinidad and Tobago

McGaw, D., Clarke, W. and Maharaj, S., (2016), “Comparison of supercritical fluid extraction with steam distillation for the extraction of bay oil from bay (pimenta racemosa) leaves”, International Journal of Engineering and Science Invention, Vol.5, No.1, pp. 51-55.

Michał Brokl, Fauconnier, M.-L., Benini, C., Lognay, G., du Jardin, P. and Focant, J.-F. (2013), “Improvement of ylang-ylang essential oil characterisation by GC×GC-TOFMS”, Molecules, Vol.18, No.2, pp.1783-1797.

Paltoo, V. (2002), Supercritical Fluid Extraction of Jasmine, Ph.D. in Chemical Engineering (Unpublished), Department of Chemical Engineering, The University of the West Indies, Trinidad and Tobago.

Patel, S. (2013), “Pumpkin (Cucurbita sp.) seeds as nutraceutic: a review on status quo and scopes”, Mediterranean Journal of Nutrition and Metabolism, Vol.6, pp. 183-189.

Sellier, B. (2016), A Process for the Supercritical Fluid Extraction of Pumpkin Seed, M.Sc. Dissertation (Unpublished), Department of Chemical Engineering, The University of the West Indies, Trinidad and Tobago.

The National World (2015), “Production of secret to Chanel N°5 under threat in Comoros”, accessed September 2016, from: http://www.thenational.ae/world/africa/production-of-secret-to-chanel-n5-under-threat-in-comoros

Watson, M. (2005), Supercritical Fluid Extraction of Ylang Ylang, PhD in Chemical Engineering, (Unpublished), Department of Chemical Engineering, The University of the West Indies, Trinidad and Tobago.

Authors’ Biographical Notes: Sharad Maharaj is Lecturer in Chemical Engineering at The University of the West Indies, where he specialises in Separation Processes and Numerical Methods. Dr. Maharaj holds a Ph.D in Chemical Engineering from The University of the West Indies (UWI) in the area of extraction processes with special reference to the use of Steam Distillation and Supercritical Fluid Extraction to extract high value products from indigenous plant materials. He currently leads the research work of the Extraction Laboratory at The UWI.

Marian J. Watson is Associate Professor at The University of Trinidad and Tobago and currently serves as the Vice Provost of Undergraduate Programmes, Foundations and Prior Learning, as well as the Programme Leader for the Process Engineering programmes. She strives for quality chemical engineering education and producing the industry ready graduate. Dr. Watson holds a PhD from The University of the West Indies where she researched the extraction of essential oils using supercritical CO2. After working in the petroleum refining sector, she returned to academia where her current research interests include engineering education, separation processes and process engineering design.

Rosemarie Skeene is Senior Instructor at The University of Trinidad and Tobago. Mrs. Skeene holds a Master of Philosophy degree in Chemical Engineering and a Bachelor of Science degree in Chemistry and Zoology. At present, she is pursuing her PhD in Chemical Engineering; her research is on the Extraction of Turmeric using Sub-critical and Supercritical CO2.

David R. McGaw holds B.Sc and M.Sc degrees from The University of Wales and a Ph.D from The University of the West Indies. After working as a Process Engineer in artificial fibers and subsequently in compound fertilisers, he joined the teaching staff of The University of the West Indies in 1967. He retired in 2003, having also served as the Head of Department and Dean of the Faculty of Engineering. In 2006, he joined The University of Trinidad and Tobago (UTT) as Vice Provost, before being appointed Provost in 2007, retiring from the UTT in 2009.

R.A. Camacho: Some Examples of Innovative Projects in the Manufacturing Sector in Trinidad and Tobago

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Some Examples of Innovative Projects in the Manufacturing Sector in Trinidad and Tobago

Roger A. Camacho

Consulting Engineer, Trinidad and Tobago, West Indies; Email: [email protected]

(Received 05 October 2016; Revised 20 March 2017; Accepted 28 April 2017) Abstract: There is tremendous opportunity for engineers in Trinidad and Tobago (T&T) to create and execute innovative projects in their manufacturing companies. This is in spite of many traditional owners of small, medium and large factories being hesitant to invest in “local talent” due to the fear of failure and the “Colonial” attitude that LOCAL = BAD and FOREIGN = GOOD. These projects need not be massive undertakings that require huge capital investments, but small specialised designs that solve specific problems in the factory. In many cases, the innovative aspect of the design may involve the creative use of materials found in the scrap heaps of the companies. Other innovative solutions may not result in a physical technological device or system but by using a different approach or different method to solve a recurring problem. This paper presents four (4) innovative projects completed over the last few decades that were designed, built, tested and put into service in one factory in T&T. It aims to stimulate the engineering community, and shows to the national and regional manufacturing sector that innovative solutions to problems need not require huge sums of money to implement and higher technical degrees to conceive and analyse. Experience has shown that companies with the foresight and willingness to take the risk by implementing many small innovative projects and new ideas over time will have the competitive advantage over other manufacturers of similar products.

Keywords: Industry, manufacturing, local design, competitive advantage, creative design, Trinidad and Tobago 1. Introduction Trinidad and Tobago has a long history of engineering and technological applications due to its involvement in the petroleum and sugar industries for over a century. However, almost all of the equipment and systems used in these industries, as well as the tools and service equipment for these industries, were imported from the United Kingdom, Europe, and North America. As Trinidad and Tobago began its thrust in the 1960’s into local manufacturing of consumer goods (import substitution) many individuals opened factories to take advantage of the protection offered by the government of the day instituting negative lists and high import tariffs. The machines used by these manufacturers were all imported from the countries listed above. After several decades the local manufacturing sector, in general, still have little confidence in local engineers and technicians to invent machines or modify existing machines and systems to increase production. The colonial attitude that LOCAL = BAD and FOREIGN = GOOD still prevails. However, there are a few local manufacturers who may “take a chance” with a local engineer or technician to produce some innovative solution to a recurring problem in the factory. Once successful it opens up tremendous opportunity to create and execute other projects in their manufacturing companies.

This paper presents four (4) innovative projects completed over the last few decades that were designed, built, tested and put into service in one factory in Trinidad and Tobago (T&T). The following will be presented for each

project: (a) the problem that needed to be solved, (b) the design considerations, (c) the engineering and scientific principles used, and (d) the final device/system that was built or implemented. It should be noted that all the design and construction was done by local engineers and technicians. Maximum use was made of locally available or locally manufactured materials. Imported materials, equipment and devices were only used if they were not made locally or not available locally. 2. Project 1: The use of a Chilled Water Air Handling

Unit as a Cooling Tower 2.2 Project Descriptions A local paper converting factory uses a central vacuum system for several of its manufacturing machines. The vacuum pumps need a constant supply of cold water to cool the pump and provide the vacuum seal. However, the supply of water to the factory was unreliable and limited to only a few hours per night for a few days per week; even with adequate storage tanks, the water supply usually ran out towards the end of the week. With no water the vacuum pumps had to be shut down resulting in the shutting down of production from all the machines that use central vacuum. Downtime is the greatest cost in this factory and cost the company thousands of dollars per hour; therefore an urgent solution to the problem was required.

The objective was to reduce the factory demand for water by cooling and recycling the water from the vacuum pumps. Commercially available cooling towers are


Vol.45, No.1, July 2017, pp.26-31


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expensive, have long lead times for delivery, need foreign exchange, and need constant water treatment chemicals. After much thought, an innovative solution was proposed; the use of a chilled water air handling unit as a cooling tower. Chilled water air handling units are made locally and are readily available, payment was in TT$, the system is “closed loop” therefore a minimum use of water treatment chemicals would be necessary.

The system conceived consisted of cooling water tanks, a supply pump, the vacuum pumps, the vacuum pumps separator units, a sump to receive the hot water from the vacuum pumps, return pumps, the cooling tower and interconnecting pipe. A schematic of the system is shown in Figure 1.

Figure 1: Schematic of Cooling System for Vacuum Pumps

Since there is some evaporation of water in the

Cooling Water Tanks and the Separator Units connected to the Vacuum Pumps, “make-up” water is added to the Cooling Water Tanks through a water softener. The engineering design of the system required information and calculations to determine (a) the flow rate of water required for the vacuum pumps, (b) the amount of heat that is picked up in the vacuum pumps and must be rejected in the cooling tower, (c) the amount of “make-up” water required (estimate), and (d) the amount of “hardness” that must be removed from the make-up water. Other calculations were required to determine the diameters of the inter-connecting pipes (not discussed in this paper).

Vacuum pump manufacturer’s data and simple measurements of the water leaving the vacuum pump give the water flow rate through each vacuum pump as 6 gallons per minute, and the temperature of the water entering the vacuum pump at 100 ºF and the temperature leaving the vacuum pump at 120 ºF.

Therefore, the Heat Gained in the Vacuum Pumps = Heat to be Rejected by the Cooler = m X Cp X ΔT

Where: m = mass flow rate of water through the vacuum pump, lb/hr Cp = Specific Heat Capacity of Water = 1 Btu/lb. ºF ΔT = Temperature rise of water in vacuum pump (ºF) =

Temperature drop of water in Cooler (ºF) Therefore, the heat to be rejected by the cooler per vacuum pump:

= 6 gal/min. X 8.34lb/gal X 1 Btu/lb ºF x (120-100)ºF X 60 min./hr

= 60,048 Btu/hr per vacuum pump Since we are using air conditioning equipment which

is rated in “tons” of cooling, we convert to “tons”. Therefore cooling capacity = 60,048 Btu/hr / 12,000 Btu/hr/ton = 5 tons per vacuum pump.

Designing for 4 vacuum pumps and making allowances for very hot days (which reduce the cooling capacity of the air handling unit), we select an air handling unit of:

4 pumps X 5 tons/ pump + 5 tons (allowance for very hot days) = 25 tons Although the system is a closed loop system, make-

up water is required to replace water lost due to evaporation from the water tanks and from the separator units after the vacuum pumps. The make-up water is automatically added to the water tanks through a water softener (to remove hardness) and a float valve for level control. The size of the water softener must be determined. This is done by estimating the amount of make-up water that is required and the “hardness” (Ca CO3) of the water. Analysis of the water performed by WASA’s laboratory shows a hardness (Ca CO3) value of 15 ppm. Estimating evaporation losses at 1% of supply water,

Make-up water required = .01 X 24 gpm X 60 min/hr = 14.4 gph

For re-generation of the water softener at a rate of once per week at two 8 hour shifts per day, the amount of hardness that needs to be removed:

= 14.4 gal/hr X 8.34 lb/gal X 16 hr/day X 5 days/week X 15 lb hardness/1,000,000 lb water

= 0.144 lb hardness per week or 0.144 lb/week X 7000 grains/lb = 1008 grains of hardness per week

A water softener with a capacity of 14.4 gallons per hour and 1000 grains of hardness was specified. Since the water softener is automatically re-generated we estimate the re-generation rate at:

14.4 gal/hr X 16 hr/day X 5 days/week = 1152 gallons per week The re-generation was set to take place after 1000

gallons of water has flowed through the softener, allowing a 10% safety factor to ensure complete removal of all the Ca CO3 from the water. 2.2 Lesson Learnt


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The system demonstrates that in much factory engineering work the mathematical analysis is relatively simple requiring the use of simple algebraic equations. Other considerations that affect the performance of the cooling system are: • Outdoor air temperature. • Heat lost from the interconnecting steel pipe. • Heat lost due to evaporation of water from the surface

of the uncovered water tanks. • Because the water tanks are open to the air, there is

biological contamination. Therefore a biocide had to be occasionally added to prevent slime build-up.

• Corrosion of the steel pipe. A corrosion inhibitor also has to be occasionally added to the cooling water.

• A control system was designed to: o Automatically start and stop the pumps and AHU

when any vacuum pump is switched on and off o Control the water level in the water tanks o Control the water lever in the vacuum water sump o Sound an alarm for high water supply temperature Regarding the performance evaluation, the process

water consumption was reduced by 99%. The estimate of 1% evaporation was accurate and only make up water was required. Downtime as a result of not having water for the vacuum pumps was reduced to zero, and the water supply to the vacuum pumps never exceeded 95 ºF.

It was observed that the temperature rise through the vacuum pumps was always 20 ºF regardless of the supply temperature. The increase cost to the company for the operation of the cooling system was negligible when compared to the cost of having to pay for transportation for water and the cost of downtime. Figure 2 shows the air handling unit used as a Cooling Tower.

Figure 2. Air Handling Unit used as a Cooling Tower 3. Project 2: The Modification of Flexographic

Printing Press

3.1 Project Descriptions An envelope manufacturing company wishes to supply envelopes to a customer that requires the printing of the customer’s logo as well as some marketing information on the front of the envelope. The customer’s graphic design department proposes that the printed information uses five colours for impact. The company’s largest envelope making machine has a four colour printing press in its assembly. No other envelope manufacturer in the country has a five (or more) colour printing press attached to their envelope machines. The alternative to a five colour press is to manufacturer the envelopes first and then print them using an offset printing press. This method is very expensive and results in high waste. An innovative and creative solution was required to get the job and keep costs to within acceptable limits.

The solution conceived was to convert one of the flexographic printing presses to print two colours by dividing the ink tray into two parts, side by side, to hold two different colour inks; then split the ink transfer roller and annilox roller into two sections. This method would give the capability of five colours but only if the one of the colours was on the right hand side of the envelope.

An Annilox Roller is a specially designed roller with laser engraved micro pockets on its surface which holds a metered amount of ink. The ink is transferred from the ink tray to the Annilox roller by the ink transfer roller. The flexographic printing plate then picks up the ink from the Annilox roller and transfers the image to the paper.

After some negotiation with the customer, the modification was agreed because of the significant price advantage and minor difference to the “look” of the envelope. Figure 3 shows the four colour flexographic printing press.

Figure 3. Four Colour Flexographic Printing Press

The technical team was very concerned that there will

be some splashing and mixing of the two inks in each half


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of the ink tray and some migration of the ink from one side of the roller to the other side. The ink tray was divided into two parts by sticking a flat piece of stainless steel across the centre of the tray with epoxy. The rollers were cut very deep and wide in their centres to prevent ink from one side migrating to the other side of the same roller. Figure 4 shows the split rollers of one printing station.

Figure 4. Split Rollers of one Printing Station 3.2 Lesson Learnt

This innovation gave the company a unique competitive advantage over all the other envelope manufacturers in the country. The cutting of the rollers and the installation of the dividing plate were both done in-house, therefore at a marginal cost. The modification to the printing station does not affect future jobs as one colour ink could be added to both sides of the ink tray.

Regarding the performance evaluation, there was no mixing of ink between the sides of the ink tray and between the sides of the rollers. A slight speed reduction was necessary. This is normal as more printing stations are used. Additional adjustments to the printing plates on the split roller were necessary for proper alignment of the print. 4. Project 3: An Electronic Window Patch Detection

System for a Reel Fed Envelope Machine 4.1 Project Descriptions Many envelope customers use automatic machines to insert letters, bills, etc. These machines can run at speeds of 20,000 to 40,000 envelopes per hour. At these speeds if an envelope does not open as required a “jam” occurs which can cause serious administration problems (with customer bills), reduce production capacity, damage the insert, and may damage the machine. The main cause of a window envelope not opening is the sticking together of

the front and back of the envelope. Therefore the quality of the envelope is crucial to the customer and must perform in his insertion machine continuously. Figure 5 shows a window section of an envelope machine.

Figure 5. Window Section of Envelope Machine

During the manufacture of a window envelope, the window patch adhesive is first applied to the side of the paper which will become the inside of the envelope; the clear plastic window patch is then placed over the adhesive. After other operations, the paper is finally folded to create the envelope. If no window patch gets applied, the front and back of the envelope will stick together when folded over. Envelope machines produce envelopes at rates up to 10 envelopes per second. At these speeds, a total inspection of each envelope is impossible, therefore a statistical inspection is carried out. Because of the low frequency of envelopes with missing window patches, the inspection does not effectively detect these “bad” envelopes. However, one or two “bad” envelopes in 50,000 are unacceptable due to the stated problems.

The company therefore had to find a solution to detect and remove 100% of the “bad” envelopes from the production run before they go into the boxes. Research on the internet did not reveal the availability of any such device. Communication with the international Envelope Manufacturers Association also did not reveal such a device. A detection system therefore had to be created in-house. Some of the objectives and considerations for the design are: • The instrument must detect all missing window

patches. • The instrument must identify which envelopes are

missing window patches so that they could be removed from production.

• No part of the instrument must touch the paper as marks will be left on the paper; therefore the sensor must not contact the paper.


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• There must be no appreciable loss in production speed therefore the detector must have a very fast response time.

• Materials for the device must be readily available. A look around the factory at other machines with

detection instrumentation revealed a fibre optic light beam sensor with a response time of 15 milliseconds. The device operates by sending a beam of light through one fibre and detecting its reflection off the surface of the paper through another fibre. The presence or absence of the reflected light is used, through some electronics, as a switch. Calculating backwards to determine the production speed possible with this response time, we calculate as follows: • Each envelope has an “open” length of 10 inches. • Using a machine speed at the lower end of 300

envelopes per minute. The paper speed = 300 env/min X 1 min/60 s

X 10 inches/env = 50 inches/s For a window size of 1 inch long, the “exposure” time of the window to the sensor = 1 inch / (50 inches/s) X 1000 ms/s = 20 ms Therefore, the maximum machine speed possible with a sensor with a response time of 15 ms = 300 env/min X 20/15 = 400 env/min.

The next issue that need to be solved was to identify the “bad” envelopes. After discussion, it was decided to identify the “bad” envelopes by blowing open one of the side seal flaps with a puff of air. A solenoid valve will be opened by a signal from the optical sensor and the air will be directed through a nozzle positioned close to the edge of the paper. The solenoid valve also has a response time to open and close (approximately 1 second in this case) therefore we need to determine how far away from the detector the nozzle should be placed to open the envelope that was detected. Figure 6 shows a fibre optic sensor on the envelope machine.

Figure 6. Fibre Optic Sensor on Envelope Machine

From the calculations above, with a paper speed of 50 inches/s and a response time of 1 second, the distance the paper travels in 1 second = 50 inches. Therefore the nozzle should be placed at least 50 inches from the sensor for a production speed of 300 envelopes per minute. The theoretical number of envelopes that will be opened in 1 second = (50 inches/s) / 1 env/10 inches = 5 envelopes.

However, tests show a total of only three or four envelopes were opened when one envelope with a missing window was detected. Due to the low frequency of missing windows, the additional loss of three or four envelopes was considered acceptable. 4.2 Lesson Learnt Regarding the performance evaluation, the system detected and identified all envelopes with missing windows. Due to the response time of the solenoid valve at least 3 or 4 envelopes were rejected each time the sensor detected a bad envelope. This level of waste was considered acceptable due to the low frequency of bad envelopes and compensated by the fact that no bad envelopes were packed. Moreover, production speed was set at 300 envelopes per minute to ensure 100% detection of bad envelopes. This machine speed at the low end of production was considered acceptable and still profitable since the company could now guarantee zero bad envelopes. 5. Project 4: A Management/Administrative System

That Eliminated Tool Pilferage A local manufacturer continued to report a high incidence of tool pilferage on the plant. In typical fashion he increased security at the gate with bag and vehicle checks. He also implemented with his security company random checks of employee lockers. The main issues with tool pilferage are the cost of tool replacement and the unavailability of the tools to do a job when needed. In fact, the unavailability of tools could have a higher cost impact that the cost of the tool itself, as it may result in longer downtimes on adjusting machines and using improper tools could damage machine components.

The solution to the problem was to implement a Tool Lending Policy where the workers would sign a note book when a tool was borrowed, and the supervisor would inspect the tool and sign it in when it was returned. The owner took some time to be convinced and try out the system and after much communication with the workers explaining the benefit of such a policy; namely, the tools will always be available to all workers if they are not stolen. The company followed through with its commitment of lending any tool to all workers (after operating instructions were explained), including very expensive power tools. Also, maintenance workers could use the work shop on off days with the approval of the supervisor. After at least 15 years of the policy, no tools were stolen from the company.


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When workers are treated with respect and are brought into the problem solving process, great results are possible. 6. Conclusion This paper presents to the national and engineering community four of many innovative and varied projects that were executed in the manufacturing sector during the last few decades. • The first project describes a water saving solution

that uses a chilled water air handling unit as a “cooling tower”.

• The second project describes how a four colour flexographic printing press was used to print five colours on an envelope machine.

• The third project describes the design of a system to detect the absence of a window patch on a window envelope that is manufactured on a “Web” envelope machine.

• The fourth project describes a management/ administrative decision and system taken which eliminated the pilfering of tools from the factory. None of the projects required a large capital

investment; instead, the innovative solutions that were created made maximum use of locally manufactured equipment, spare or scrap parts from the company’s stores or “bone yards”. Only two of the projects presented required some engineering and mathematical analysis. The other two projects were creative and innovative ideas that provided solutions to recurring problems. To conclude this paper with a quotation made from (Dyson, 2017), “A good scientist is a person with original ideas; a

good engineer is a person who makes a design that works with as few original ideas as possible.” Reference: Dyson, F.J. (2017), Freeman John Dyson, Accessed March 2017,

from: https://en.wikipedia.org/wiki/Freeman_Dyson Author’s Biographical Notes: Roger Anthony Camacho is a Professional Engineer registered in Trinidad and Tobago and the State of Oklahoma, USA with over thirty-five year experience in industry. He began his technical education at John Donaldson Technical Institute in 1971. This was subsequently followed by a Diploma of Technology (Magna Cum Laude) in Natural Gas and Petroleum Technology, at the British Columbia Institute of Technology, a Bachelor of Science degree, Cum Laude, in Mechanical Engineering from the University of Tulsa, Oklahoma, USA, and a Master of Science degree in Engineering also from the University of Tulsa. Over the last 35 years, Eng. Camacho was engaged by numerous clients including the Pan American Health Organisation, Bel Air Hotel, National Commercial Bank, the Caribbean Development Co. Limited (CARIB), Industrial Rubber Products Ltd., John Dickinson & Co. (WI) Ltd., and engineering consulting firms in Trinidad. Engineer Camacho is involved in the development of the profession through Association of Professional Engineers of Trinidad and Tobago (APETT). He held various positions in APETT including Assistant Treasurer for two terms, Treasurer for two terms, and Vice President for one term. Engineer Camacho taught several courses and seminars through APETT. Engineer Camacho also taught part time at John S. Donaldson Technical Institute and the University of Tulsa. Eng. Camacho is the Chairman of the Boiler Examiners Board and is involved in other national professional and social institutions. He is the author of several referred publications and presentations.

P. Narinesingh: The Status of Remote Sensing Information in Capturing and Applying to Environmental Resources

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The Status of Remote Sensing Information in Capturing and Applying to Environmental Resources

Pramenath Narinesingh

Department of Civil and Environmental Engineering, The University of the West Indies, St Augustine, Trinidad and Tobago, West Indies; Email: [email protected]

(Received 05 October 2016; Revised 20 March 2017; Accepted 24 June 2017) Abstract: Data is the backbone of planning and development. However, insufficient use has been made of the present technology to capture and assemble data on natural resources, and to plan the development and restoration efforts towards a sustainable future. Sustainable development includes growth that meets the needs of all without endangering the natural resources needed for the future. Therefore, it is essential to consider both conservation and the restoration of threatened resources including soil, water, forest, wetlands, environmental preserves and reserves, wild life, biota, land, coasts and seas. Restoration does not simply imply returning to a static point in the past but an adapted present condition that will continue to provide the ‘threatened’ services. The remote sensing technology and the advancement in Geographic Information System make it easy to capture environmental data rapidly, almost anywhere on the planet, and in real time accurately process it into useful information. This technology is widely used outside the Caribbean Islands (e.g. to reduce risk and increase production in agriculture), while significant sums of monies are spent in projects with a paucity of data. The absence of adequate data would result in non-sustainable planning solutions and less efficient development. Through the integration of information from Satellite and Earth Observation Systems from around the world, better informed decisions may be made regarding biodiversity and ecosystem sustainability, disaster resilience, food security, sustainable urban development, and water resources management given the anticipated dramatic fluctuation in weather. Notwithstanding, our best efforts to forward sustainable Terms of Reference for projects we fail to produce the necessary results due to the lack of data at the required level of detail. This paper brings awareness to practitioners and researchers of the use and availability of Remote Sensing Information as a major data source for environmental projects.

Keywords: Remote sensing, Satellite images, Environmental data, Resource management 1. Introduction The Caribbean community comprises many independent political states, and as Small Island Developing States (SIDS) they separately have inadequate resources to meet all their needs. Therefore, some of their needs, in spite of the high importance are inadequately satisfied or not met. One critical need common to all is the monitoring and conservation of the environment and management of the natural environmental resources (such as water, land, coasts, seas, and ecology). The necessary complement of data required for predicting and monitoring the environment is never complete and the economic decisions made are usually with high risks based on the inadequate data. One example of the impact of inadequate data and environmental assessment studies is the loss of World Bank funding for a major highway in Trinidad. However, major projects still move forward in spite of the absence of adequate data.

Coastal protection works are also of major concern for the SIDS as sea level rises and coastal erosion threatens real estate, wetlands, and beaches that provide most of the income through tourism. Eco-tourism is a thriving business for the local population and the travel industry. The challenge is to manage and protect these resources which cover extensive areas and even

challenging terrain. Sound management is only possible through adequate monitoring, assessment, and timely decision and action. Further, funding for the adequate staff and equipment, using historical methods, for the various environmental parameters; vegetation type, vegetation health, soil moisture and temperature, habitat identification, ecological health and diversification, water quantity and quality, wave height, beach width, rainfall intensity and duration, flood event, extent and duration, becomes insurmountable for individual SIDS. This paper brings awareness to practitioners and researchers of the use and availability of Remote Sensing Information as a major data source for environmental projects.

2. Background of Remote Sensing Information The solution to the data collection and analysis challenges lies in Remote Sensing (Satellite and Radar equipment) and software through the capacity to automate the processes that will reduce the otherwise large manpower and time to collect and analyse the necessary data. Additionally, Earth Observation Systems (EOS) can collect a large variety of information simultaneously, continuously and at a variety of details. The USA alone has over 80 Space Based Earth Observation Instruments and together with other partners there are presently at


Vol.45, No.1, July 2017, pp.32-41


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least 40 more (NAS, 2008). Figure 1 shows the present trend of older Satellites reaching the end of their design life. Hence, many general satellites having outlived their service life are falling out of space resulting in a rapid decrease in their numbers. More focused and multipurpose sensors, relating to the environment, are being loaded onto single satellites and are programmed to be launched or have already been launched.

Figure 1. The present trend of older Satellites reaching the end of their design life

Source: Abstracted from NAS (2008)

The data NASA collects with its EOS include the earth’s surface and the interior, biosphere, atmosphere, cryosphere and oceans, which are then processed using sophisticated programmes that include additional data such as population, societal habits and needs to provide critical environmental information. The data and information generated by NASA are made available to industry and other stakeholders that together inform on a range of societal needs including weather forecast, climate projections, sea level change, water management, disease early warning, agricultural production, response to natural disasters, and mineral resources (NAS, 2015, 2016).

Evidence of the interest and adaption to Remote Sense data products can be seen in the behavioural change of the everyday person who checks the latest weather forecast on their smart phones knowing that it is likely to change. Weather forecasts at intervals of hourly, daily and weekly have become key input factors in planning their activities. However, the accuracy of the weather predictions relies on both local and extended information, including historic and recent past data resulting in a large number of parameters, that is best analysed with sophisticated software programmes. The most recent development in this area is the Water Model for Flood Forecasting across the USA. This was announced on 22nd March 2016, at a White House Water Summit (WHWS, 2016).

The model comprises geospatial analysis technology from (Environmental Systems Research Institute (ESRI), California, USA, and Water Data Management and Analytics from KISTERS (IT specialists from Germany).

The model would be used for research and monitoring over 2.7 million streams and 6,600 sub-basins in the USA. It would provide forecast of stream flows and flood inundation with online interactive maps.

The complement to the Remote Sensing information is the ground based information for calibration and monitoring, together with wireless sensors and transmitting instruments connected to the internet infrastructure. The combination of these three aspects of the system could facilitate instant information transfer, real-time monitoring, assessment, prediction and decision making. Presently, there are a variety of modes of transfer of information and communication within the data network, from the time consuming standalone data loggers that requires a laptop to physically transfer the information or a radio modem linked to servers, to the automatic systems that directly uses WiFi routers to communicate with the sensors and an Institute’s specific sensor network systems using Global System for Mobile Communications (GSM) (Hart and Martinez, 2015).

The Caribbean Drought and Precipitation Monitoring Network (CDPMN) recently issued a Drought Bulletin, predicting the potential rainfall for the Caribbean countries from May to July 2016 (see Figure 2). This initiative was launched under CARIWIN (Caribbean Water Initiative) in 2009 to improve the Water Resources Management and sustainability in the region. The CDPMN comprises the Caribbean Institute for Meteorology and Hydrology (CIMH) and McGill University. This is part of the Caribbean Climate Outlook Forum (CariCOF) and part of the Regional Climate Outlook Forums (RCOF) sponsored by the World Meteorological Organisation (WMO).

Figure 2. Rainfall prediction map produced by the Caribbean Drought and Precipitation Monitoring Network,

Source: Based on CRCC (2016)

The CariCOF programme includes over 20 of the region’s meteorologists, climatologists and other industry and academic stakeholders (CariCOF, 2017). They together determine the monthly and short term (3-6 months) forecast of rainfall, temperature, and drought for the Caribbean Basin, as well as at the scale of the country


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(Trotman et al., 2008). This model of co-operation and joint venture using EOS is also available for many environmental parameters and products through the Intergovernmental Group on Earth Observations (GEO). 3. Development and Caribbean Issues Environmental data (such as land use, topography and water bodies) have been captured by cameras and converted to maps since the early 1900’s. With the development of computers and analytical software, extraction and manipulation of environmental information from maps became simpler and the numbers of users and uses have been continuously increasing.

Nowadays, satellites (with high spatial resolution, wide range of radiometry, band numbers, and band width, frequent coverage, and additional environmental sensors), high speed computers, extensive internet coverage, large data storage, and wireless network, remotely sensed data in natural resources mapping and environmental process modelling have become popular (Melesse et al., 2007). Some of the environmental modelling practices include: 1) Urban mapping – buildings, roads, parking lots,

sidewalks, garden, cemetery, soil, water, parks 2) Hydrological modelling - watersheds, hydrologic

features, flood mapping, land cover classification using visible, infrared and thermal spectra, water and heat flux (surface properties of radiation, temperature, water content, and aerodynamics), rainfall runoff, percolation

3) Crop water balance modelling – yield forecasting, soil moisture content, evapotranspiration,

4) Habitat delineation - using input from the above The above models are necessary for understanding

the interaction with the earth and the environment. It is also essential for efficient use of the earth’s resources and the improvement of life on the planet. No society is self-reliant; each one depends on the other for resources of raw material, labour, trade and security.

The Caribbean islands possess limited budgets relative to their population size, with the exception of Trinidad and Tobago (T&T). Trinidad and Tobago is considered to be the richest among its island neighbours with a GDP per person of over US Dollars 19,274.6 for 2015 (see Tables 1.and 2). However, the country is not without its challenges, such as flooding, droughts, low

Table 1. Central Bank of Trinidad and Tobago GDP per Capita, 2010- 2015

Date GDP Per Capita (US$) 2010 16,888.30 2011 19,180.40 2012 19,322.90 2013 19,809.70 2014 20,344.40 2015 19,274.60

Source: Abstracted from Central Bank (2017)

Table 2. Ranking of GDP per Capita 2015, Latin America and the Caribbean

Countries Relative GDP per Capita Countries Relative GDP

per Capita Trinidad and Tobago 1 Grenada 0.37 The Bahamas 0.98 Ecuador 0.37 Chile 0.75 St. Lucia 0.35

Antigua and Barbuda 0.71

St. Vincent and The Grenadines 0.35

Panama 0.67 Dominica 0.34 Uruguay 0.66 Jamaica 0.28 St. Kitts and Nevis 0.65 El Salvador 0.27 Suriname 0.54 Paraguay 0.27 Venezuela 0.54 Belize 0.26 Barbados 0.51 Guatemala 0.24 Costa Rica 0.48 Guyana 0.23 Colombia 0.44 Bolivia 0.20 Dominican Republic 0.41 Nicaragua 0.15 Peru 0.39 Honduras 0.15 Haiti 0.06

Source: Abstracted from IMF (2017) agricultural production, poor planning and development, border security, fisheries management, wild fires, unplanned development and illegal and inadequately managed quarrying (Jaramillo et al., 2014; Narinesingh, 2014). Moreover, there are limited manpower resources available to physically collect and analyse all the data relevant to all the challenges, in addition to manpower shortages there is the problem of discontinuous and spotty environmental data. Many of these issues are also shared by other Caribbean countries in varying magnitudes.

Governmental agencies with responsibilities regarding food production, water resources, flood management, marine resources, and securing the marine borders, are all short of manpower, equipment and funds for collecting data, adequately analysing the data and determining the most feasible actionable plans. Data collection programmes are started with the best of intentions and later on discontinued, disrupted, or re-assessed downwards for a variety of reasons of which funding is usually one, which directly impacts manpower and operations.

In the Caribbean, when agriculture was the main stay, there was an abundance of rain gauges scattered around the country, usually in plantations, which were maintained and well managed. However, with time and change of focus many of these gauges fell in disuse and disrepair. The number of functioning gauges reduced and the geographic coverage and the density also significantly reduced, especially in T&T. These historic data nevertheless provided a basis for many of T&T’s hydrologic prediction curves, Intensity Depth Frequency rainfall curves (IDF). A host of changes occurred over time with Institutions responsible for surface flows,


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maintenance of rivers, recording rainfall data and water quality. The net result over time is a spotty historic collection of data for most gauges.

The best opportunity for collecting data would be one that requires minimal human resources such as instrumentation that once commissioned will collect and transmit data directly to the manager or user. Off course this requires capital investment, but usually this is affordable. However, the problems arise when there is the need for increase field workers or instrument attendance, or there is a need to cut costs for projects that provide instant tangible results like physical infrastructure of roads and buildings. The solution is to minimise human resources and maximise the use of technology. Hence, by implement strategies that minimise human input in the data collection and in the retrieval process accompanied with using analytical techniques that are fast and automated, the staffing costs will be minimised. Moreover, partnering with several differently able international institutions would reduce the risk of simultaneous loss of financial capacity and disruption of the process.

Minimise Human Resources = Capital + Technology The realisation that every individual’s negative

impact, or positive impact, on the environment accumulates like drops of rain that produces a river flood that travels day and night crossing international boundaries, or like air that freely moves around the planet transporting aerosols, VOC, and dust, makes it necessary to consider the sustainability of the planet and the human race on a global scale, while, simultaneously keeping an eye on the local environmental changes. The air in the atmosphere and the waters in the ocean circle the globe, although their rates of mixing, travelling and accumulation are different effects on the local, the regional and the international communities are assured. Therefore, it is our cumulative consumption of energy; production of wastes; carbon footprint; water footprint; land use changes; as well as our individual quantities: as persons, communities, industries, towns, cities, countries and continents that must be assessed and controlled. Hence, a holistic approach is required to track the sources and the sinks of the environmental problems and challenges.

It is with this understanding that the United Nations General Assembly (UNGA, 2015) adopted the resolution that provides an agenda for “people, planet and prosperity.” This agenda requires all countries and stakeholders to collaborate as partners to free the human race from poverty and to take steps that will put the world on a sustainable and resilient path. To this end, some 17 Sustainable Development Goals have been identified that will over the next 15 years stimulate action targeted at areas of “critical importance for humanity and the planet”.

The National Research Council (NRC) generated a report based on a "decadal strategy survey of earth science and applications from space that would develop the key scientific questions on which to focus Earth and Environmental Observations in the period 2005-2015 and beyond, and present a prioritised list of space programmes, missions, and supporting activities to address these questions”. According to the report of the National Academy of Science (NAS, 2007), it states that:

“Natural and human-induced changes in Earth's interior, land surface, biosphere, atmosphere, and oceans affect all aspects of life. Understanding these changes requires a range of observations acquired from land-, sea-, air-, and space-based platforms.” “…. a new agenda for Earth observations from space in which ensuring practical benefits for humankind plays a role equal to that of acquiring new knowledge about Earth. Those benefits range from information for short-term needs, such as weather forecasts and warnings for protection of life and property, to the longer-term scientific understanding necessary for future applications that will benefit society in ways still to be realised.”

3 Technological Tools: Remote Sensing Justification A remote-sensing instrument collects data about an object or phenomenon without being in direct contact with it e.g. a camera. Telescopes and satellites are excellent examples of non-intrusive observation and remote sensing instruments. For a detail history of the progress in remote sensing, quality and application of sensors see the review by Melesse et al. (2007).

Satellite data at various resolutions can provide the needed data in the desired frequency, quality and quantity and may be paid for from the benefits gained by the appropriate application of the data and overall costs savings in data collection (continuity and accuracy). Furthermore, satellite provides the opportunity to obtain accurate data such as coastline location and condition, forest resources, and real-time marine conditions which are presently all far from acceptable (limited and sparse) given Governments’ resource, and are essential for budgeting the use of our limited resources including the financial and human.

The future space missions for the next decade must focus on the Earth and the needs of the Environmental Scientific Community to support activities that will best inform the broad range of societal needs: reliable weather forecasts, early earthquake warnings, improved pollution data and management. To achieve these goals, there should be an integrated system capable of disseminating and retrieving satellite data and results from forecasting models. Some of the urgent questions noted in the NRS (2008) report have since materialised, including:

“How will economic development affect air pollutants and their movement among regions and continents?


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Can we better predict the risk of avian flu outbreaks or the potential spread of mosquito-borne viruses as climate evolves? Will heat waves and tropical cyclones intensify or become more frequent with climate change?”

Figure 3 gives one example of the significant difference satellite information and hydrological modelling made in the accuracy of tracking the Hurricane ‘Sandy’ of October 2012. This resulted in the timely warning of the population of New Jersey, USA. Computer modeling by the European Center for Medium-Range Weather Forecasts (ECMWF) using satellite information from the polar-orbiting satellite (POS) predicted five (5) days in advance that the storm was going to pass within 30 km of the New Jersey shore line. Figure 3. The Hurricane Sandy forecast from ECMWF with (Left)

and without (Right) the polar-orbiting satellite data Source: Abstracted from Freedman (2012)

It is reported that the death toll of 125 persons, mostly due to drowning from the storm surge, and the estimated USD$ 100 billion in damages would have been worst (Freedman, 2012) was it not for this early warning. Overall the Hurricane Sandy caused extensive losses in the Caribbean (including Jamaica, Cuba, Haiti, Dominican Republic, Puerto Rico, The Bahamas) 24 states in the USA and in Canada. For New Jersey, the warning may not have been timely if the POS data was not available since the ECMWF would have predicted, without the POS data, that the storm’s trajectory would be 100’s of kilometers offshore (see Figure 3).

The range of spatial scales (sub meter to 1000’s of kilometers) and time scales (real time, hourly, daily to annually) of remotely sensed data in mapping the land surface, ocean and lake bodies, and the atmospheric properties make natural resources mapping and environmental analysis appropriate for assessing environmental issues holistically. Furthermore, the larger the scale of the project the more economical is the analysis. Worldwide collective participation would easily reduce the burden of costs per nation and provide countless benefits.

Since 1999, the Earth Observing Systems (EOS) (Terra satellite) has been providing global coverage, frequent repeat coverage, high level of georectified and at satellite reflectance, and later Tropospheric pollution measurements (Terra/Aqua satellite). With the growing advancement of computer power, storage and modelling, more products such as Land Use Land Classification (LULC), and leaf area index (LAI) are available. Furthermore, additional satellites with an increased number of sensors from institutions and private industries focused on environmental applications and natural resources management have catapulted the field of environmental investigation and management (Melesse et al, 2007).

Unfortunately, many countries remain in the shadows as they rely on more conventional methods of data gathering and analysis with little support from the new technologies. The environmental problems are multi-disciplinary with several linkages (Showstack, 2015). For instance, food security has been linking to climate, energy and water. Scientists and researchers should not work in isolated groups, and should share data including the data of institutions. This effort can put thousands of scientists to work together to address the food security problem. Already, data from the Intergovernmental Group on Earth Observations (GEO) are being used in agriculture. However, much work remains with the GEO in achieving its overall vision (Showstack, 2015).

“The GEO is currently working with 100 members (99 nations and the European Commission) and 93 scientific and technical participating organisations (including Future Earth, the World Bank, and the World Meteorological Organisation) to build GEOSs. That project integrates an increasing number of resources from satellite- and ground-based Earth observation systems from around the world, and it facilitates sharing that information to help with better-informed decision making across a number of “societal benefit areas.” “Those areas include biodiversity and ecosystem sustainability, disaster resilience, food security, sustainable urban development, and water resources management, with climate spanning all these areas.”

The ‘Pleiades-1A satellite of Figure 4 is one of several satellites (WORLDVIEW-1, 2, and 3, QUICKBIRD, GeoEye-1 and 2, IKONOS, SPOT-6 and 7, SkySat-1 and 2, TerraSAR-X) that the Satellite Imaging Corporation accesses to provide satellite imagery and data. The resolution of the images ranges from 0.51 m to several kilometers. Their services include remote sensing, mapping, GPS satellite surveying and positioning, in agriculture they provide types, quality, quantity and location of crop, changes, yield determination, soil analysis (organic content) and irrigated landscape mapping. These analyses are accomplished in a mapping environment such as a Geographic Information System, where vegetation classification, soil analysis, crop management and tree grading can be accomplished via the


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colours of the images Normalised Difference Vegetation Index (NDVI).

Figure 4. Pleiades-1A Satellite Sensor (0.5m) Source: Abstracted from Amazonaws (2017a)

Image Copyright © AIRBUS Defence & Space

Samples of processed satellite images in Figure 5 show the ‘Green Vegetation Index’ (GVI) where the varied colours in the maps may relate to crop vigor, vegetation density or biomass. Furthermore, using additional sensors, information on the near surface soil is captured and converted into Soil Zone Index (AgrowatchTM Soil Zone Index) from which levels of moisture content, distribution of sand, clay and organic matter may be delineated. The Soil Zone information is valuable for managing irrigation, fertility and production especially in determining the distribution of crops in variable soil types, improving soil properties and irrigation management pre- and post-harvest. This information will greatly benefit the identification of suitable lands for development into large farming communities where efficient use of water and high production is essential and may even provide recommendation for improving present production. Figure 5. Differencing the classes of vegetation, soil zones and tree

maturity via the NDVI - AgroWatch™ Index Maps Source: Abstracted from Amazonaws (2017b)

Image Copyright © DigitalGlobe

Moreover, the use of this technology combined with good farming practices can advance the movement towards food sufficiency. In farms that produce tree crops

or sustainable lumber production AgrowatchTM Tree Grading Map identifies the location and extent of each tree canopy that informs the farmer of the maturity, health, replacement demands or harvest status thereby optimising the management of the farm. This information on a timely basis can be an advantage when dealing with the climatic variability where too much rain or the need to irrigate is critical to the quality and quantity of produce.

NASA has had to alter several of its Earth Science and application programmes due to budget cuts and rescheduling. Its National Polar-orbiting Operational Environmental Satellite System (NPOESS) is one example where schedule launch was delayed by two years and the number of sensors was reduced to only the “core” sensors, which relates to weather forecasting (NAS, 2007; NAS 2005). The Caribbean States and other less financially able and vulnerable countries should join or partner with NASA through organisations like the GEO to facilitate their Environmental Security and protection against natural disasters. It’s in the Caribbean’s interest that these programmes be well funded even if the funds are sourced as parts of other programmes such as food security, natural disaster management, environmental protection and sustainability.

Autonomous Vehicles (AV) refers to machinery that moves without a driver in the vehicle. They may be in the water (Autonomous Under water Vehicle, AUV), in the air (Unmanned Aerial Vehicle, UAV) or on land (Unmanned Ground Vehicle, UGV). The more frequently used AVs for environmental monitoring are the AUV and the UAV. AVs are becoming vital for reconnaissance in the scientific world in the fields of meteorology, hydrology, geography, and oceanography. The costs of these vehicles (especially drones, usually a term for UAV) have been dropping to the extent that an average person can afford one.

Drones provide instant visual information via live video through wireless means, including on board recording, at high resolution in times and areas where satellites are unavailable or costly. They are maneuverable, i.e. they can remain in one position (i.e., stationary), or their flight path can be programmed using GPS ensuring the precise path and elevation above a datum which also makes it repeatable. Given the miniaturisation of sensors it is anticipated that drones will be able to provide additional data such as air quality. One major limit is the distance it can travel which is dependent on the range of the controller (signal for remotely controlling the device) and the life of the battery. This means that there is a limit to flying time and the geographic area covered. However, these benefits outweigh the limits.

Researcher from the University of Salford, England surveyed the flood inundation from the storm ‘Desmond’ of January 2016 using a drone. The advantages of the drone included 1) covering 60 km of the 160 km long river (River Eden) from a distance of 500 m in one day

Green Vegetation Soil Zone

Tree Grading

http://www.satimagingcorp.com/applications/natural-resources/agriculture/agriculture-management-green-vegetation-index-satellite-images/

http://www.satimagingcorp.com/applications/natural-resources/agriculture/agriculture-agrowatch-soil-zone-index/

http://www.satimagingcorp.com/applications/natural-resources/agriculture/agriculture-treegrading-maps/


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and 2) revealing the real time extent of the flooded area. This information leads to improved understanding of the flood way capacity, processes of flooding and erosion and identification of key areas for flood management (Kinver, 2016). Prior to the use of drones, this exercise would have required expensive helicopter time, an expensive video recorder and an expert camera person, all of which would make the exercise much more expensive. Furthermore, the availability of these resources at the same time in extreme events or natural disasters can be challenging. The images and data collected by drones can be processed in many instances like satellite images to generate new information, and even support information such as ground truth.

4. Other Environmental Engineering Applications Satellite images of a flood event when compared at times before and after the event can yield a variety of information including: extent of flooding, estimate of damages, land loss or gain, property boundary line movements and bank erosion rates. Figure 6 shows the river bank lines of the Arima River, Trinidad determined from a series of aerial and satellite images.

Figure 6. The river bank lines of the Arima River, 1994-2006

The relative geographic position of the lines over the years allows one to track the movement of the river centreline and its banks. When comparing the position of the lines between 2005 and 2006, it can be determined

that the land movement of the river was significant for the instances captured. Using the image of the 2006 event as the background for the river planforms, one can identify the movement of the planform as it relates to the post flood events in terms of sediment deposition and channel location. Moreover, the net removal of soil may be determined with supporting ground survey data of bank heights if not available from satellite elevation data (altimetry) however, a good estimate can be made of the plan area lost to erosion from the aerial images.

The assessment of a specific event at a location can present challenges when acquiring aerial and satellite images from a secondary source. Some of the issues include availability of the image for the exact location, resolution of the image at the scale necessary for making the necessary observations, the time and date, obstructions by clouds or shadows, and bands necessary for differencing vegetation type. However, these challenges may be reduced when your needs are the objectives of the data collection. This would require specific instructions based on specific needs for both general coverage as well as event based coverage.

Furthermore, there should be allowances for additional requests in emergency cases. It therefore follows that careful planning and monitoring based on specific scientific and developmental goals must be prepared by the client. Naturally, many of the environmental goals will overlap for a given region, which creates the opportunity for collaboration and joint venture. The number of risks and environmental issues that require monitoring may also be demanding for a single Caribbean state, therefore, opportunities further present themselves for some countries to be specialised in some specific field and simultaneously serving the region as with CIMH in meteorology (Trotman, 2008).

O’Neal and Pizzuto (2010) analysed the vertical bank erosion to a level of centimetre square in their study of mercury contaminated sediments using a ground based LiDAR (Light Detecting And Ranging) instrument. The LiDAR functions as a scanner picking up the reflected light from a surface, and determines the distance of the image from the instrument. The process is suitable for field work of lengths of a few meters to 10’s of meters, where there is clear sight of the river bank. The data collection is quick and when processed using repeated surveys after flood events accurate bank surface changes can be determined. Figure 7 shows the application of Ground Based LiDAR in a study used to estimate the volume of eroded river bank material contaminated with mercury.

For the need to quantify the volume of mercury entering 40 km of a river system in Virginia, USA required the quantification of contaminated sediment entering the river via bank erosion. The results of the study of the river bank erosion modelling for a section of the river are presented in Figure 8. This study was required to predict the erosion rates of river bank material


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along 40 km of the South River, Virginia, USA. The most efficient approach for studying and analysing such an extensive area was determined to include the use of random soil samples, remote sensing and hydraulic modelling.

Figure 7. The images (A) A black and white photo mosaic of the study bank, (B–D) shaded relief models developed from ground-based LiDAR, (E) a grid model of the erosion occurring between September 2006 and March 2008, and (F) the mean (gray) and

standard deviation (black) for each 5 cm wide, vertical profile from the dataset presented in E

Source: Abstracted from O’Neal and Pizzuto (2010) Figure 8. Image (A) presents the areas of documented bank erosion

and image (B) represents the predicted areas of erosion by the hydraulic model. The determined excess velocity is used to quantify

the volume of material eroded

Source: Abstracted from Narinesingh and Pizzuto (2007) This method minimised cost, time and manpower

used in the field and provided a tool that may be used to monitor the rate of contamination over time. The physical information (data) required for the model included river slope, river widths, coordinated geographic location of the river banks and its centreline, soil type along the river banks and its bed, location and dimensions of physical structures along the river (bridges, bank protection works, small dams, tributaries). The data sources included Satellite images, aerial photographs, land use maps, geological maps, and Air-borne LIDAR. Arc GIS was the main tool used to extract the data from the above list and to present the model results. Data extracted included contour maps, channel dimensions and water surface slopes, changes in river planform and geographic location of the bank lines (over time) and erosion rates of soil types and erodibility values of specific bank locations. The GIS also provided the visual presentation of the hydraulic analysis in the form of changes in the position of the river bank lines which combined with the predicted velocity from the hydraulic model identified the relationships of planform, bank material type, slopes and erosion rates (Narinesingh, 2010).

The most significant remote sensing satellite carded to be launched in 2016 by NASA is the HyspiIRI, with a mission to provide imaging spectroscopy (optical hyperspectral imaging), thermal infrared measurements (multispectral infrared), and IPM direct broadcast. This data will be useful in 1) understanding volcanic eruptions and predictions; 2) determining nutrients and water status of vegetation, soil type and health; and 3) identification of locations of natural resources. Although the satellite has yet to be launched developments of hardware, software and training in the science and applications workshops and data product symposia have been on-going (Arthur Charo, 2015; Hyspiri, 2017).

5. Conclusions This paper presents a general overview of the application of remote sensing facilitating acquisition of large quantities of data in the field of environmental study to meet today’s world needs to protect more assets and become more efficient in the use of the planet’s natural resources and more so given the present climatic variations. Remotely sensed methods provide relatively easy access and rapid acquisition of the data. Through the internet and computers, transmission and processing of the data provides useful information quickly. By pooling the resources nationally and internationally of research institutions, scientists, managers and financiers the development and funding of the necessary tools (such as satellites and sensors, modelling software, advanced computers, and communication systems) could easily be released to monitor and develop the environment sustainably; move towards improved quality and quantity


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of agricultural products; and receive adequate advanced warnings on disasters.

The Caribbean Drought and Precipitation Monitoring Network is a working model for combining space-based Earth Observing Systems (EOS) and the cooperation of researchers, industry, international partners and other stakeholders to produce an essential societal environmental product, rainfall prediction. Therefore, it is timely that the Caribbean States expand their usage of EOS and join the relevant international stakeholders to guarantee that the Caribbean would obtain regional specific information and support that is relevant to the societal needs. These include weather forecast, climate projections, sea level change, water management, pollution quantification, disease early warning, agricultural production, warnings and response to natural disasters, and mineral resources exploitation.

Acknowledgements: The author wishes to thank the Editors and the Reviewers for their comments.

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Author’s Biographical Notes: Pramenath Narinesingh holds a Bachelor of Science in Civil Engineering (UWI), a Diploma and Masters of Science in Hydraulic Engineering (UNECSO-IHE), and a Ph.D in Fluvial Geomorphology (UD, USA). He is a Registered Engineer with the Board of Engineering of Trinidad and Tobago. He has received Fellowship from The Netherlands to study River Engineering and Floodplain Sedimentation at the UNESCO-IHE water institute in Delft, The Netherlands. His MSc. thesis was entitled Nature Restoration and Floodplain Sedimentation. His work in sedimentation has been referenced in the American Society of Civil Engineers (ASCE) Manual of Sedimentation Engineering (2010). Dr. Narinesingh has also received awards and fellowships at the University of Delaware, USA to undertake a Ph.D. in Fluvial

Geomorphology. His work focused on the planform of rivers. Dr. Narinesingh has a broad range of professional experience in civil engineering including, project management, contract management, construction management, and designs. He has worked as an engineer in the Drainage Division for ten (10) years. His PhD research included an assessment of the suitability of a curvature driven hydraulic river model in predicting river bank erosion. Dr. Narinesingh has been lecturing at The University of the West Indies, St. Augustine campus since August 2010 in the Department of Civil and Environmental Engineering

J.V. Smith et al.: Plastic Waste to Petrochemical Feedstock in Trinidad and Tobago

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Plastic Waste to Petrochemical Feedstock in Trinidad and Tobago

Jeffrey V. Smith a,Ψ, Sydney Thomasb, Lebert H. Griersonc and Alan J. Harperd

a,b Department of Chemical Engineering, The University of the West Indies St Augustine, Trinidad and Tobago, West Indies; E-mails: [email protected]; [email protected]

c Department of Chemistry, The University of the West Indies, St Augustine, Trinidad and Tobago, West Indies; E-mail: [email protected]

d School of Engineering and Physical Sciences, Heriot-Watt University, Edinburgh, Scotland, EH14 4AS, United Kingdom;

E-mails: [email protected], [email protected] Ψ - Corresponding Author

(Received 15November 2016; Revised 3 July 2017; Accepted 12 July 2017) Abstract: The 1.5 million plastic bottles disposed in Trinidad and Tobago (T&T) on an average day generate some 11,000 tonnes of polyethylene terephthalate (PET) waste per annum. A percentage of these bottles are ‘recycled’ (the rest going to landfill or disposed indiscriminately in the environment), but this ‘recycling’ just amounts to chipping up the bottles and shipping to Asia. Thus, a valuable hydrocarbon resource is lost to the islands’ industries or, worse, ends up creating an environmental problem. The recent drop in the international value of oil, with its consequent serious implications for T&T, makes it necessary to minimize outflows of foreign currency from the country. The recycling of these plastic bottles (currently treated as waste) could result in the dual benefits of reduction in foreign currency outflows and negating an adverse environmental situation. This paper gives as background on the history and the uses of PET. It reviews the alternative manufacturing routes for PET and highlights the alternative approaches available for the recycling of waste PET, including physical, chemical and energy valorisation options. As a direct application of the discipline of Industrial Symbiosis (IS) in a T&T perspective, the methanolysis of waste PET to produce dimethyl terephthalate (DMT) and ethylene glycol (EG) is explored. The benefits of the implementation of this recycling option could be threefold: providing alternative feedstock, reducing foreign currency outflows and tackling an environmental problem. This work represents a review in the context of the Caribbean, the purpose being to stimulate interest and set a start line for further research and industrial cooperation.

Keywords: Polyethylene terephthalate, PET, plastic recycling, Industrial Symbiosis, methanolysis

1. Introduction In Trinidad and Tobago (T&T), some 1.4-1.6 million polyethylene terephthalate (PET) water/soft drink bottles are disposed daily (Jurawan-Richards 2015). This amounts to some 11 thousand tonnes of PET per year. The corresponding figure for Jamaica would be in the range of 1.15 million bottles per day, corresponding to some 8.4 thousand tonnes of PET per year (Smith 2016). While some of these discarded bottles are ‘recycled’, the remainder would end up as landfill or would be disposed indiscriminately in the environment. The latter can often be seen scattered along waterways and shorelines, especially after heavy rains. This represents a major environmental challenge to the country. In addition, a valuable hydrocarbon resource is lost to the islands’ industries.

Various collection and ‘recycling’ initiatives exist in the country for dealing with discarded PET bottles. However most such initiatives amount to no more than collecting, crushing/grinding, baling, and shipping out of the country – mainly to Asia. Numerous recycling methods exist for dealing with waste PET and these have

been successfully implemented in developed countries, but that is not the case locally or regionally.

The discipline of Industrial Symbiosis (IS) is focused on the development of techniques to turn apparent waste into industrial feedstocks. One feature of applying IS to an isolated community, is to fit techniques of valorisation to industries and technologies already employed. T&T, renowned as a major international player in methanol synthesis, would be an ideal location for the recovery of feedstock from waste PET via a process of methanolysis. The product of this process could be introduced into an upstream position in a petrochemical chain (new to T&T), involving the manufacture of PET resin. The recycling of these PET bottles (currently treated as waste) would result in the additional benefits of reduction in foreign currency outflows and negating an adverse environmental situation.

This paper will first present the history, the uses and the manufacture of PET. The alternative approaches available for the recycling of waste PET, including physical, chemical and energy valorisation options are then highlighted. The methanolysis of waste PET to produce dimethyl terephthalate (DMT) and ethylene


Vol.45, No.1, July 2017, pp.42-49


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glycol (EG) – as an application of IS – is explored. A T&T/Caribbean perspective is maintained. 2. PET - History, Uses and Manufacture Polyethylene terephthalate is the common or trivial name for the IUPAC named poly (ethylene terephthalate) with CAS Registry Number 25038-59-9. It is represented by the molecular formula (C10H8O4)n with the structure as shown in Figure 1.

Figure 1. Structure of PET

PET is a versatile polyester which can be used in one-dimensional (fibres – textiles, carpets), two dimensional (films) and three dimensional (bottles) applications (Yoshioka and Grause 2006). McIntyre (2003), in an examination of the historical development of polyesters, traced early work leading to the development of PET to DuPont laboratory in 1928. Initially invented and used as a fibre, its potential use as a film soon caught on. Patents in the early 1970s, including one by DuPont, led to the development and use of PET in bottles.

Between 1990 and 2010, the worldwide demand for PET was expected to increase by a factor of almost 5, while the percentage of PET going into bottle production was expected to rise from almost 10% to 33% (Yoshioka and Grause 2006). The world production of PET in 2016 is expected to be some 56 million tonnes.

PET is manufactured via one of two main routes (Bartolome et al. 2012), both of which produce the intermediate monomer bis (2-hydroxyethyl) terephthalate (BHET) in the first step of a two-step process.

The first step of the first route involves the esterification of terephthalic acid (TPA) with ethylene glycol (EG) to produce BHET, along with water as shown in Figure 2. This reaction takes place at 240-260°C and at 300-500 kPa (Awaja and Pavel 2005).

Figure 2. Esterification reaction between TPA and EG

The first step of the second route involves the transesterification of dimethyl terephthalate (DMT) with EG to produce BHET, along with methanol as shown in Figure 3. This reaction takes place at 150-220°C and at 100 kPa (Awaja and Pavel 2005).

Figure 3. Transesterification reaction between DMT and EG

Karayannidis and Achilias (2007), note that, while the industrial practice was to use the transesterification of DMT, the esterification reaction between TPA and EG has taken over as the preferred method for the manufacture of PET. It is worth noting that both reactions are reversible and in order to shift the equilibrium to the right, the reaction by-products, water or methanol must be removed. This is accomplished due to the high temperature of the reaction (Welle 2011).

The second step, common to both routes, involves the polycondensation of BHET to produce PET in melt phase with the release of EG under high vacuum, as shown in Figure 4.

Figure 4. Polycondenstaion of BHET to form PET

Awaja and Pavel (2005) break up the above step into a pre-polymerisation step, in which BHET is polymerised to a degree of polymerisation (DP) of up to 30 at 250-280°C and 2-3 kPa., followed by the polycondensation process where the DP is increased to 100 (suitable for fibres and sheets). This occurs at 270-290°C and under high vacuum (50-100 Pa). Solid-state polymerisation (SSP) (Culbert and Christel 2003) operating at 200-240°C and 100 kPa with a residence time of 5-25 h, could then be used to increase the DP to 150. To produce bottle grade PET with an intrinsic viscosity (I.V.) of 0.70-0.81 dL g-1, SSP would normally be carried out at 210°C for 15-20 h. Since this reaction is also reversible, it is necessary to remove the EG produced, in order to drive the equilibrium to the right. This is achieved by a combination of vacuum and high temperature (Welle 2011).

The overall reaction involving TPA and EG may be alternatively represented (Sinha et al. 2010) as involving just the release of water as shown in Figure 5.

Figure 5. Overall reaction forming PET from TPA and EG

Similarly, the overall reaction involving DMT and EG should alternatively be able to be represented as


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involving just the release of methanol as shown in Figure 6.

Figure 6. Overall reaction forming PET from DMT and EG

The significance of the equations represented by Figures 4, 5 and 6 will become obvious when one considers the tertiary recycling of PET. 3. Recycling Methods for PET The recycling of polymers in general, and of PET in particular, may be carried out in various ways. The terminology used to describe the various plastic recycling methods has been termed complex and confusing (Hopewell et al. 2009). Mastellone (1999) identified four possible ways to recycle plastics. These have been termed primary, secondary, tertiary and quaternary, and have been discussed by various authors (Karayannidis and Achilias 2007; Hopewell et al. 2009; Al-Salem et al. 2010; Sinha et al. 2010) with respect to plastics in general and PET in particular. In addition to the four methods referred to, a fifth method, the so-called ‘zero order’ recycling technique, has been considered by Achilias et al. (2012) and Bartolome et al. (2012). A brief overview of the various methods in which polymers in general and PET in particular can be recycled follows, but a more detailed treatment can be found in Smith (2016). 3.1 Zero Order Methods The direct re-use of a plastic object is a ‘zero order’ recycling technique (Achilias et al. 2012; Bartolome et al. 2012). The reuse of a grocery bag or the refilling and reuse of a PET bottle are examples of zero order recycling. These practices are common in the developing world and can be seen in use in the Caribbean. Care must be taken with the reuse of PET bottles though, since contaminants could be absorbed into the plastic and released back into the food when the bottle is refilled. 3.2 Primary Methods Primary methods for polymer recycling are termed either mechanical or closed-loop recycling (Hopewell et al. 2009) or termed re-extrusion (Al-Salem et al. 2010; Brems et al. 2012). This method involves the in-plant recycling (re-introduction into the extrusion cycle) of pre-consumer industrial scrap material that has similar features to the original product. It thus requires uncontaminated scrap and thus can only deal with single-type waste.

While the primary method of recycling is practiced with many polymers, it hardly finds application with PET.

This is due to the fact that, upon re-extrusion, PET undergoes both mechanical and thermal degradation. This results in a drop in intrinsic viscosity and molecular weight (Smith 2016), making it unsuitable for use in the original application unless there is some further treatment. 3.3 Secondary Methods Secondary methods, alternatively called physical or mechanical recycling, essentially involve collection of the material, cleaning, grinding and melt processing, and reforming of the plastic material (Sinha et al. 2010). Generally these methods are used to produce products requiring lower properties (Hopewell et al. 2009). With PET in particular, the combination of heat, mechanical energy and moisture during melt processing leads to chain scission reactions, resulting in a product of lower intrinsic viscosity or molecular weight, which is unsuitable for bottle formation unless an additional processing is step included (Sinha et al. 2010).

Earlier mechanical recycling schemes for PET bottles involved the open loop formation of products such as fibre, fibre fill, strapping or sheet (Culbert and Christel 2003). Other applications for mechanically recycled PET include non-woven fabric, carpets, shopping bags, non-food containers, large moulding, and engineering resins (Scheirs 1998). In the sandwich process, a core of recyclate is coated inside and outside by virgin PET. In this case, up to 40% recyclate can be used and the products can be used in food applications.

The first bottle-to-bottle recycling process for post consumer PET in direct food applications was approved in the USA in 1991 (Welle 2011). Over the last 25 years, there has been growing use of mechanical bottle-to-bottle recycling of PET. However, hygiene is a major issue if the bottle is to be used for food applications. Nowadays sophisticated decontamination processes, some involving water and some involving caustic soda - so-called super-clean recycling processes - are available for the decontamination of post-consumer PET as part of mechanical bottle-to-bottle processes (Welle 2011).

However, the action of reprocessing PET through an extruder results in a lowering of the intrinsic viscosity and molecular weight, resulting in a product which would not be suitable for bottle production even if all hygienic requirements are met. The technology has been developed though to perform solid-state polymerization during the mechanical recycling of PET (Culbert and Christel 2003), thereby producing a recycled product which can go directly into bottle manufacture. The result is the growing application of mechanical bottle-to-bottle recycling, especially in Japan. 3.4 Tertiary Methods Tertiary (sometimes referred to as chemical or feedstock) recycling refers to advanced technology processes which convert plastic materials into smaller molecules - usually


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liquids or gases. These products are suitable for use as a feedstock for the production of new petrochemicals and plastics (Mastellone 1999).

While used loosely or interchangeably by some authors, Tukker (2002) and Ali and Siddiqui (2006) are specific in defining chemical recycling as implying a change of the chemical structure of the material, but in such a way that the resulting chemicals can be used to produce the original material again. Such processes may include monomer recovery. Feedstock recycling on the other hand implies a change in the chemical structure of the material, where the resulting chemicals are used for a purpose other than producing the original material.

For most polymers, the term ‘tertiary recycling’ would imply a thermal or catalytic process to produce chemicals or feedstock. However, PET (which is formed by condensation polymerization with the consequent liberation of small molecules during formation) can be reverted back to the constituent monomers (TPA, EG, DMT and BHET) in the presence of an appropriate solvent and under appropriate process conditions. This is termed solvolysis (also called chemolysis), and is a type of chemical or tertiary recycling which generally does not apply to other polymers. These solvolysis methods can be viewed as the reverse of the processes of PET production discussed in Section 2.0. Yoshioka and Grause (2006), Sinha et al. (2010), Bartolome et al. (2012) all give detailed accounts of the various solvolysis options for recycling PET. A short review follows.

Glycolysis is currently the most important solvolysis process for PET. The solvent is EG, and BHET is formed as the simplest oligomer of PET, as shown in Figure 7.

Figure 7. Glycolysis of PET

The reaction is performed at 190-200°C and 3.0-4.0 MPa. Glycolysis is the simplest, oldest and least capital-intensive solvolysis process for PET. A glycolysis and polycondensation plant with a capacity of 27,500 tonnes per year has been operating in Japan since 2003.

Alcoholysis with methanol (methanolysis) is the most general method of manufacturing DMT and EG from waste PET, as shown in Figure 8.

Figure 8. Methanolysis of PET

The reaction conditions are 180-280°C and 2.5-4.5 MPa. Further discussion on the methanolysis process is given in Section 5.0.

Hydrolysis is the saponification of PET with water to form TPA and EG as shown in Figure 9. The reaction is performed at 200-250°C and 1.4-2 MPa. The residence time tends to be long for complete depolymerization. This method is generally not used for food-grade recycled PET due to the high cost of purifying the recycled TPA.

Figure 9. Hydrolysis of PET

It is worth noting that the glycolysis, methanolysis and hydrolysis reactions represented respectively by Figures 7, 8 and 9 are simply the reverse of the PET production reactions presented in Figures 4, 5 and 6, respectively.

Thermal processes for polymer recycling (thermolysis) refer to the process of treatment in the presence of heat, under controlled temperatures and without catalysts (Achilias et al. 2012), generally leading to smaller molecules (Buekens 2006). Thermolysis processes can be divided into (a) pyrolysis (thermal cracking in an inert atmosphere), (b) gasification (cracking in the sub-stoichiometric presence of air usually leading to CO and CO2 production), and (c) hydrogenation or hydrocracking (cracking in the presence of hydrogen). The result is valuable products (e.g. fuels and oils) which are clean and of high calorific value (Al-Salem et al. 2010). As opposed to incineration, they generally produce no toxic or environmentally harmful emissions (Scheirs and Kaminsky 2006).

Pyrolysis, also referred to as polymer cracking, can be defined simply as the degradation of polymers at high temperatures under non-oxidative conditions. The result is valuable products (e.g. fuels and oils) which are clean and of high calorific value (Al-Salem et al. 2010). The main advantage of pyrolysis is that it can deal with a variety of wastes including mixed plastic waste and biomass streams which would be otherwise difficult to deal with, and it results in useable products.

Gasification (Al-Salem et al. 2009, 2010; Jung and Fontana 2006) refers to the partial oxidation of organic matter at high temperatures (1,200-1,500°C) (Aguado et al. 2007), using sub-stoichiometric oxygen/air (20-40% of that needed for complete combustion (Brems et al. 2013)), steam or carbon dioxide as the oxygen source. The main product of gasification is synthesis gas (syngas) which consists of carbon monoxide and hydrogen. The gasification of PET could be represented by the reaction shown in Figure 10.


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Figure 10. Gasification of PET

Syngas may be used as a substitute for natural gas or as a feedstock in the synthesis of ammonia, methanol or other chemicals. It may also be used to produce synthetic diesel, or it may be burnt directly as a fuel. Gasification is seen as an attractive alternative to incineration since it does not result in the formation of dioxins and aromatic compounds (Brems et al. 2012). The general conclusion is that the gasification of PET is an appropriate way for the production of syngas. With multiple ammonia and methanol plants located in Trinidad, syngas production would be very relevant to this country.

Also referred to as hydrocracking, hydrogenation implies the addition of hydrogen by chemical reaction through some process (Scheirs 1998; Al-Salem et al. 2009, 2010). While the cracking process is endothermic, the process of hydrogenation is exothermic and thus the two processes complement each other. The resulting product contains hydrocarbon fragments with an appearance and composition similar to crude oil and can be directly used in petrochemical plants or in the refining industry (Scheirs 1998). This process requires that such a plant be located near a refinery, a requirement that can be met by both T&T and Jamaica. 3.5 Quaternary Methods Quaternary (or energy valorization) methods utilize waste plastic for its calorific or energy value. These methods (Tukker 2002; Al-Salem et al. 2009, 2010; Brems et al. 2012) include incineration and disposal in cement kilns. There are also existing and emerging applications in the iron and steel industry (Sahajwalla et al. 2010; Hasanbeigi et al. 2013).

While incineration could result in a 90-99% volume reduction for plastic solid waste, there are environmental concerns associated with it. These include excessive emissions of CO2 and the generation of oxides of nitrogen and sulphur, volatile organic compounds, particulate matter, heavy metals, polycyclic aromatic hydrocarbons and dioxins. Carcinogenic substances have been identified in airborne particles from incineration or combustion of synthetic polymers including PET. In the Caribbean, while landfill space could be an issue, especially in the smaller islands, intentional incineration of garbage is not practiced and there would certainly be no drive to utilize waste for the production of heat.

Cement kilns can be utilized as incinerators to dispose of waste plastics (Jung and Fontana 2006; Al-Salem et al. 2009, 2010; Brems et al. 2012). Wei-Muddeen (2004) examined the use of waste-derived fuels - including PET in cement kilns generally, and

specifically in kilns operated by the Trinidad Cement Limited (TCL) Group, which curently operates cement plants in Trinidad, Jamaica and Barbados. According to Wei-Muddeen, the TCL group has taken the initiative to make its cement kilns available to the regional community so that the significant pollution prevention and other environmental benefits from the diversion of wastes from landfills and unauthorized disposal areas can be obtained. The benefit of this initiative across the Caribbean would be obvious, but it has not in fact been implemented on any large scale across the region.

PET waste can be used to replace coke for the generation of carbon monoxide and heat in the smelting of iron ore for pig iron production in a blast furnace (Ali and Siddiqui 2006; Buekens 2006; Al-Salem, et al. 2009, 2010; Hasanbeigi et al. 2013). In this case, the PET can act as both a fuel to supply energy in the subsequent combustion phase and as a reducing agent in the pyrolysis and gasification processes, replacing coke. (It can thus strictly be classified as both a quaternary recycling method, as well as a tertiary (feedstock) recycling method.)

An emerging technology (Sahajwalla et al. 2010, Hasanbeigi et al. 2013) is the utilising of waste plastic as a resource for electric arc furnace (EAF) steelmaking. The EAF technology of steelmaking utilises carbon-based materials as an agent to form slag. Anthracite and metallurgical coke is often used for this purpose (Hasanbeigi et al. 2013). Work is ongoing in this area to replace some of the coke with waste plastic (which would provide both an energy source and a carbon source). While no evidence has been found of commercial implementation, prototype plants have been constructed (Hasanbeigi et al. 2013). 4. The Methanol Industry in Trinidad and Tobago Trinidad and Tobago is the world’s largest exporter of methanol, with 21% of the global market trade. There are currently seven (7) methanol plants operating in the country, with a total capacity of 6.5 million tonnes per year. This figure has been consistent since 2005. Production has been between 84% and 91% of capacity over the last six years. The actual production in 2015 was 5.51 million tonnes (84.8% of capacity). Some 65-75% of T&T’s methanol currently goes to North America, with a small amount going to South America. Recent increases in North American supply capacity means new markets must be found in Europe and China (Paltoo 2016). 5. Methanolysis as a PET Recycling Option In the methanolysis process, PET is treated with excess methanol at 180-280°C and 2.5-4.5 MPa with metal acetic acid salts used as catalysts (Yoshioka and Grause 2006). The reaction (see Figure 8) occurs, resulting in the formation of PET and EG in stoichiometric ratio. 11 kilo tonnes of PET react stoichiometrically with 3.6 kilo


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tonnes of methanol and the yield of DMT varies between 80 and 85%. This reaction is relatively tolerant to impurities in the input materials and can be performed either batch wise or continuously.

The methanolysis process was patented in 1957 by DuPont, and from 1960 onwards, various alternative processes were developed. During this time period, methanolysis recycling plants were set up by a number of large PET manufacturers including Hoechst, Eastman and DuPont (Paszun and Spychaj, 1997). As recently as 2003, a 50,000 tonne per year methanolysis plant was opened in Japan. The plant has subsequently closed down, and the methanolysis of PET has virtually become obsolete internationally. The reason for this could be traced to a number of factors (Patterson, 2007; Sinha et al., 2010; Bartolome et al., 2012) including the high cost associated with the separation and refining of the mixture of the reaction products and the fact that the presence of water in the methanolysis process tends to poison the catalyst and form various azeotropes. However, the main disadvantage is associated with the trend of all of the new PET production processes to use TPA instead of DMT as the raw material.

The methanolysis process can be incorporated into a PET production line as shown in Figure 11. DMT and EG from the depolymerization reaction are subsequently reacted together to form virgin PET. Unreacted methanol from the depolymerization process, as well as methanol liberated in the PET synthesis reaction are both recycled back to the depolymerization process. Thus, while waste PET enters the system and virgin PET leaves the system, the only methanol required would be to make-up for losses in the process. Where the depolymerization and synthesis plants are located together, the reagents needed for the synthesis reaction would be generated on-site.

Figure 11. Flowsheet of the methanolysis process in the PET production line

In an integrated process which includes both PET waste depolymerization and PET production from the recovered EG and DMT (see Figure 11), issues related to

the preference of TPA over DMT as a starting material should not be as much of a concern. This would favour the serious consideration of methanolysis as a viable solvolysis option for PET. 6. Imperatives The disposal of some 11,000 tonnes of PET in T&T annually represents a serious environmental issue. It can also be viewed in terms of an outflow of foreign currency and as a loss of a valuable hydrocarbon resource to the island’s industries. The recent drop in the international value of oil, compounded with a continued decline in oil and natural gas production in T&T, has resulted in a concomitant sharp decrease in foreign currency inflows into the country. The consequent serious implications for T&T make it necessary to minimise outflows of foreign currency from the country. The recycling of these plastic bottles (currently treated as waste) could result in the dual benefits of reduction in foreign currency outflows as well as negating an adverse environmental situation.

Being renowned as a major international player in methanol synthesis, T&T, would be an ideal location for the recovery of feedstock from waste PET via the process of methanolysis. The product of this process would be able to be introduced into an upstream position in a petrochemical chain (new to T&T), involving the manufacture of PET resin. This would provide alternative feedstock while reducing foreign currency outflows and simultaneously tackling the environmental problem.

Implementation of methanolysis as a recycling option for waste PET in T&T, coupled with the establishment of a PET production facility, would represent a classical implementation of the discipline of industrial symbiosis – turning apparent waste into industrial feedstock using industries and technologies already available.

In considering the economic feasibility of such a project, the source of the waste PET does not have to be limited to T&T. With an estimated 1.15 million bottles per day disposed of in Jamaica (Jamaica. NEPA 2011), the total figure for the English-speaking Caribbean excluding T&T would be of order of magnitude similar to that of T&T, thus doubling the size of the potential raw material source. Since any recycling initiative in the other Caribbean Islands would be similar to that in T&T, i.e. collecting and shipping out of the region, shipping the discarded bottle from across the Caribbean to one central location in the region should certainly be a feasible option. Given its role as a major player in the international methanol industry, T&T would be a natural choice for the siting of a methanolysis recycling plant.

7. Conclusions and Recommendations Several conclusions and recommendation could be made as follows: • The disposal of some 11 000 tonnes of PET per

annum from water/soft drink bottles represents an


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environmental challenge for T&T, as well the loss of a valuable hydrocarbon resource.

• Recycling waste PET via methanolysis as part of an integrated PET waste depolymerization and PET production facility could tackle the environmental concern, stem outflows of foreign currency and curtail the loss of the hydrocarbon resource.

• An integrated PET waste depolymerization and PET production facility, utilising methanolysis, could be seriously considered as a viable solvolysis option for PET.

• Implementation of such a project would be a classical application of industrial symbiosis, in this case using an apparent waste material (discarded PET bottles) to provide feedstock for a PET production facility, using readily available and locally produced methanol.

• While such a project would be located in Trinidad, using methanol produced in Trinidad, the sourcing of the waste PET could be extended to the wider Caribbean and the environmental benefits felt throughout the region.

• This paper was written as a review in the context of the Caribbean for the purpose of stimulating interest and setting a start line for further research and industrial cooperation. While the discussion has focussed on the English-

speaking Caribbean, this initiative can certainly be extended to the wider Caribbean region, resulting in an environmental benefit for the entire Caribbean region. However, before any such project could be undertaken, there would be need for a more detailed examination of the technical and economic aspects of the project to determine its feasibility. A detailed examination of the economic feasibility of the process is outside the scope of this present paper, but would form the basis of a subsequent paper.

Acknowledgements: The authors would like to thank the Department of Chemical Engineering, the Faculty of Engineering, and The University of the West Indies and its Campus Research and Publication Fund for financial and other support while carrying out research in this area. References: Achilias, D.S., Andriotis, L., Koutsidis, I.A., Louka, D.A., Nianias,

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Jung, C.G. and Fontana, A. (2006), “Production of gaseous and liquid fuels by pyrolysis and gasification of plastics: Technological approach”, in Scheirs, J. and Kaminsky, W. (ed.), Feedstock Recycling and Pyrolysis of Waste Plastics: Converting Waste Plastics into Diesel and Other Fuels, John Wiley & Sons, Chichester, UK, pp. 251-283

Jurawan-Richards, S. (2015), e-mail communication with author, March 12, 2015, The Trinidad and Tobago Solid Waste Management Company Limited.

Karayannidis, G.P. and Achilias, D.S. (2007), “Chemical recycling of poly(ethylene terephthalate)”, Macromolecular Materials and Engineering, Vol. 292, No. 2, pp. 128-146.

Mastellone, M. L. (1999), Thermal Treatments of Plastic Wastes by Means of Fluidized Bed Reactors, Ph.D. Thesis, Department of Environmental Science, Second University of Naples, Italy.

McIntyre, J. E. (2003), “The historical development of polyesters”, in Scheirs, J. and Long, T. (ed.), Modern Polyesters: Chemistry and Technology of Polyesters and Copolyesters, John Wiley & Sons, Chichester, UK, pp. 3-28.

Paltoo, V. (2016), personal communication with author, April 29 2016, National Energy Corporation of Trinidad and Tobago

Paszun, D., and Spychaj, T. (1997), “Chemical recycling of poly(ethylene terephthalate)”, Industrial and Engineering Chemistry Research, Vol 36, No. 4, pp 1373-1383.

Patterson, J.D. (2007), Continuous Depolymerization of


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Poly(Ethylene Terephthalate) via Reactive Extrusion, Ph.D. Thesis, Department of Chemical Engineering, North Carolina State University, Raleigh, NC, USA.

Sahajwalla, V., Zaharia, M., Kongkarat, S., Khanna, R., Saha-Chaudhury, N. and O'Kane, P. (2010), “Recycling plastics as a resource for electric arc furnace (EAF) steelmaking: Combustion and structural transformations of metallurgical coke and plastic blends”, Energy and Fuels, Vol. 24, No. 1, pp. 379-391.

Scheirs, J. (1998), Polymer Recycling: Science, Technology and Applications, John Wiley & Son, Chichester, UK.

Scheirs, J. and Kaminsky, W. (2006) (ed.), Feedstock Recycling and Pyrolysis of Waste Plastics: Converting Waste Plastics into Diesel and Other Fuels, John Wiley & Sons, Chichester, UK

Sinha, V., Patel, M. R. and Patel, J.V. (2010), “PET waste management by chemical recycling: A review”, Journal of Polymers and the Environment, Vol. 18, No. 1, pp. 8-25.

Smith, J. V. (2016), A Study on the Recycling of Polyethylene Terephthalate (PET) With a Caribbean Perspective, Ph.D. Thesis, Department of Chemical Engineering, The University of the West Indies, St. Augustine, Trinidad and Tobago.

Tukker, A. (2002), “Plastics waste - feedstock recycling, chemical recycling and incineration”, RAPRA Review Reports, Vol.13, No.4, Report 148.

Wei-Muddeen, H. (2004), “A foundation for sustainable waste management: The regional cement industry’s solution”, Presented at the 2nd Caribbean Environmental Forum and Exhibition, Port of Spain, 31 May - 4 June.

Welle, F. (2011), “Twenty years of PET bottle to bottle recycling: An overview”, Resources, Conservation and Recycling, Vol. 55, No. 11, pp. 865-875.

Yoshioka, T. and Grause, G. (2006), “Feedstock recycling of PET”, in Scheirs, J. and Kaminsky, W. (ed.), Feedstock Recycling and Pyrolysis of Waste Plastics: Converting Waste Plastics into Diesel and Other Fuels, John Wiley & Sons, Chichester, UK, pp. 641-661.

Author’s Biographical Notes: Jeffrey V. Smith is a Lecturer in the Department of Chemical Engineering at The University of the West Indies (UWI). He completed his BSc and MASc degrees in Chemical Engineering at The UWI and The University of Toronto respectively and his PhD in Chemical Engineering at The UWI. His areas of teaching include Chemical Reaction Engineering and Computer Aided Engineering and his research interests include Polymer Recycling Studies and

Chemical Engineering Education. Jeffrey is a member of APETT and of the Caribbean Academy of Sciences, a Senior Associate Member of the Institution of Chemical Engineers (IChemE) and is part of the Trinidad and Tobago Members Group (TTMG) of the IChemE.

Sydney Thomas is a retired senior lecturer in the Chemical Engineering Department at The University of the West Indies, St. Augustine, Trinidad and Tobago. His teaching and research interests are in polymer reaction engineering and hydrocarbon processing.

Lebert H. Grierson is the Head of the Chemistry Department, and a Lecturer in Physical Chemistry at The University of the West Indies. He holds BSc and PhD degrees from The University of London. He did postdoctoral work at the Stratingh Institute for Chemistry, Rijksuniversiteit Groningen, The Netherlands and then at Max Planck Institute for Strahlenchemie (Radiation Chemistry) in Muelheim a.d. Ruhr, Germany between 1988-1991. His present research interest focuses on applied physical chemistry including topics such as waste polymer cracking using fluidised-bed technology, asphalt and cement research and application of microcalorimetry techniques to biological systems.

Alan J. Harper initially trained as a physicist and briefly worked in naval shipbuilding and atomic energy. Three years in chemical engineering research at Edinburgh was followed by nearly thirty years in the chemical industry working for ICI and its successors: Zeneca, AstraZeneca and Avecia. Dr Harper joined Heriot-Watt in 2006 taking part in the teaching for the Sustainability MSc course, thermodynamics, heat transfer, energy (also at Edinburgh University) and management systems. He organises Continuing Professional Development lectures and workshops in the School in conjunction with various professional bodies. He carries out consultancy through the university and through his firm StratoCirrus Technologies. Since 1990 Dr Harper has worked mostly in environmental protection and industrial effluent treatment. He is a founder director of Horizon Proteins Ltd which produces high value aquaculture feedstuffs from byproducts of the Scotch Whisky Industry.

H. Hassan et al.: Commuter Experience in Developing Sustainable Transit Connectivity in Diego Martin, Trinidad and Tobago

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Commuter Experience in Developing Sustainable Transit Connectivity in Diego Martin, Trinidad and Tobago

Hawwa Hassan a,Ψ, Rae J. Furlongeb, and Bheshem Ramlal c

a,c Department of Geomatics Engineering and Land Management, The University of the West Indies, St Augustine Campus, Trinidad and Tobago, West Indies; E-mails: [email protected]; [email protected]

b L F Systems Ltd, Trinidad and Tobago, West Indies; E-mail: [email protected]

Ψ - Corresponding Author (Received 06 October 2016; Revised 17 July 2017; Accepted 23 July 2017)

Abstract: Communities in Diego Martin, Trinidad and Tobago (T&T) have long suffered from poor transit connectivity which has created difficulty for residents engaging in essential daily activities. This deficiency of the transit system arose as a consequence of short-sighted land use planning policies, rapid population growth and uncontrolled increase in automobile ownership. This paper provides innovative yet practical and implementable measures to improve the sustainability of the transit system and thus alleviate the current transportation problems. It is argued that existing resources and facilities should be utilised before engaging in more expensive plans of action that are not guaranteed to achieve the desired outcome. Data was collected from both primary and secondary sources on three (3) major aspects - land use, transport demand, and transport supply. Individual factors have been analysed in terms of their ability to influence transit and the contributing role in developing the current transit system. Results show that the main factor hindering the connectivity and sustainability of the transit system of Diego Martin is the residents’ travel behaviour ignited by the obsession with automobile ownership and usage, compounded by the poor quality and level of service of the transit service. A hierarchy-based on commuter preference exists within the transport system where private transport occupies the highest rung and transit occupies the lowest. Residents have been found to be discouraged from using the transit service due to its failure to function properly and adequately. The responses received from commuters indicate that improvements in the overall performance are not enough to shift ridership from personal vehicles to transit usage. The need for new ideas is evident. This paper provides recommendations with strategies that were derived from careful consideration of the current economic climate, as well as the culture and lifestyle of the residents of the Diego Martin communities. This paper concludes that the value of transit to the sustainable development of communities and the society, on a whole, is of great significance and must no longer be ignored.

Keywords: Public Transport; Transit Connectivity; Sustainable Transit

1. Introduction Anyone who has ever travelled either out of Diego Martin, Trinidad and Tobago (T&T), on a regular weekday during the hours of 6am to 8am or into Diego Martin during the hours of 4pm to 6pm will be very familiar with the horror story that is public transport commute. Among the daily complaints of the commuters are severe traffic congestion, overcrowded transport stands, and extensive waiting periods for accessing transportation services and lengthy journeys. These challenges are not recent. However, the authorities ostensibly believe that roadway capacity expansion and infrastructural upgrades can solve all of the region’s transportation problems. To this date, such attempts have been to no avail.

Consequently, the absence of an efficient and reliable transit system continues to act as an impetus for the purchase and use of private vehicles. Over the years, commuting via public transit became characterised by unreliable and inconsistent service, lengthy waiting times at dilapidated bus stops and terminals, long hours of

commute via heavily congested roadways aboard a painstakingly slow vehicle with a high probability of shutting down. This has repelled a large faction of commuters, encouraging those who can afford to do so, to gravitate towards other transport modes, especially the private car.

The proliferation of private vehicles induces roadway congestion and further retards the operating efficiency of the transit service. Although not the sole cause of congestion, private vehicle overuse is a major contributor. As congestion builds, the average commuter’s daily trip is lengthened and the frustration of the population is heightened. Overall, Diego Martin’s transportation system is in a state of severe crisis. Innovative solutions and a new holistic approach is desperately needed to address the issues.

In the T&T context, the bus service is the only mode which fits all of the transit criteria, hence it is the mode referred to as ‘transit’ in this paper. Transit is the only mode of transport that can be afforded by all groups of society. Any obstruction in its effectiveness or ability to


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operate efficiently disrupts a large faction of the population’s ability to conduct necessary daily activities, which in turn affects the quality of life for many individuals. Article 11.2 of the United Nations’ 2030 Sustainable Development Goals (SDG’s) declares that countries are to work towards providing access to safe, affordable, accessible and sustainable transport systems for all, improving road safety, notably by expanding public transport, with special attention to the needs of those in vulnerable situations, women, children, persons with disabilities and older persons by the year 2030.

This paper advocates for the improvement of transit connectivity as a possible solution to the current transport woes, and as a step in the right direction towards sustainable transport and development. Ensuring sustainable transit connectivity satisfies both the land use and transportation planning agendas as it requires sensible land use development along with proper transportation planning measures of which a main component is improvement in the transit service. The sustainable transit connectivity notion can possibly serve as a means via which the well sought after Land Use-Transport Planning integration can be effectuated.

A shift in ridership from private transport to transit is necessary for achieving sustainable transport. This will serve to reduce competition for road space which in turn will allow for better flow of traffic and thus better operating efficiency of the transit service and increased population mobility. However, in order to effect a shift towards transit, the overall image of the service needs to be significantly improved to attract members of a car-loving society. The aim is to provide overall better transit service, not only to the transit dependent population. Strategies for achieving such are presented within. 2. Literature Review - Transit Connectivity Transit, often referred to as ‘public transit’ or ‘mass transportation’ is a term which describes public transportation for the carriage of passengers and their incidental baggage. It is further defined by Walker (2012) as any transport mode which consists of regularly scheduled vehicle trips, open to all paying passengers, with the capacity to carry multiple passengers whose trips may have different origins, destinations and purposes.

Transit connectivity ensures sustainable means of connecting persons to places via a viable transit system that is a major facet and supporting tool of a wider concept - Transit Oriented Development (TOD). Essentially, the ultimate aim of both is to create wholesome transit villages- dense, mixed-use communities that, by design, invite residents, workers and shoppers to drive their cars less and use transit more (Cervero, 1994).

This notion of transit villages is not a newly created one. In fact, it is an adaptation of similar ideologies of the “garden city” concept developed by Ebenezer Howard, an

earlier planner. However, within recent times, TOD and all of its components has gained notoriety worldwide, even being lauded as the ‘future of urbanisation’ (Shankar, 2017). Transit development has been particularly significant to the development of Indian cities like Delhi, Ahmedabad, and Mumbai. It continues to be high priority on the sustainable development of India who has undergone a nationwide effort to implement TOD measures (Sinha, 2017). Other prominent cities such as Curitiba in Brazil, Bogota in Colombia, and Stockholm in Sweden attribute much of their success in transportation development to the implementation of TOD measures. Due to the mandatory integration of land use planning and transport network improvements, they were able to create healthier, viable communities and provide a better quality of life for their citizens. For instance, Table 1 shows a comparison of transit improvement measures implemented in India.

Table 1. Comparison of Transit Improvement Measures Implemented in India

Location Characteristics Measures Implemented

Delhi, India

Population: 11 million (2011)

Density: 11.3 persons/ sq. km

1) 500m belt applied along transit corridors which covers 20% of Delhi's urban area. 2) Mixed use- reduced travel needs 3) Better light, ventiliation and quality of life 4) Redistribution of land to cater for open green spaces, buildable land area and roads 5) Finer road networks created for shortcuts on foot 6) Multi-modal integration with pedestrian priority

Mubai, IndiaPopulation: 12.4 million

Density: 31,700 persons/ sq. km

1) Increased Floor Space Index 2) Land amalgamation 3) Increased density from 400Du/Ha to 1000Du/Ha 4) Mixed use- at least 20% to be non-residential 5) Inclusionary housing- at least 30% to be for lower income earners

Source: Abstracted from Sinha (2017)

Thus, TOD, but more specifically, transit connectivity

can be considered the lynchpin to sustainable transport development. Studies have shown that the task of linking people and places requires an understanding of what drives and influences travel activity. Three (3) principal elements of transport activity highlighted by Transport Canada (2012) serve as the framework for this paper - land use, transportation demand and transportation supply (see Figure 1).

It is evident that a direct relationship exists between land use and travel behaviour Acker et al (2009) and Litman (2014). This has emerged because the spatial arrangement and design of an urban settlement influences transportation demand and accessibility (people’s ability to reach desired services and activities (Litman, 2014)), which in turn affects mobility (the amount and type of travel activity). Transport demand deals with the factors that influence whether, why, when and where people travel.


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Figure 1. The Main Elements of a Community’s Transportation and

Land Use System Source: Abstracted from Transport Canada (2012)

Transportation supply in terms of transit is concerned with satisfying the demand for transport with to the quantity required to adequately cater to the population size, as well as the desired quality and level of service. Public transit is currently considered as the ‘effective and pragmatic solution to urban transport’ (ITDP, 2016), but a bus that is deadly slow will easily become unreliable and both of those characteristics are clearly inconvenient (Philipsen, 2015).

Seeing that both other elements – land use and transportation supply- are influential on travel behaviour/ demand, efforts in transportation development tend to focus on integrating land use and improving transit service. Foremost on the Transit Sustainability Guidelines (Feng, 2010) list of recommended best practices of the transit industry is improving mobility via improved and enjoyable transit services. According to Transport Canada (2012), there are five categories that should be targeted when seeking to improve the bus service:

1) Network Planning and Services 2) Branding and Marketing 3) Right-of-Way and Transit Priority 4) Bus Stop and Bus Station 5) Vehicle

Once done correctly, the entire transit system stands to be upgraded to a higher level of efficiency. The commuter’s main goal is movement from one destination to the next with the greatest ease and least disruption possible. Within the transit planning society, it is believed that a transit service should aim for more than just providing the user with a bare minimum service. Rather, ensuring a comfortable and attractive experience, should be of greater concern. The strategy to attract people to transit focuses on increasing convenience, affordability and the promise of performance. Retaining riders is based

on reliability and on the many other aspects of a customer’s experience that influence feelings of safety, trust and ease-of-use (OC Transpo, 2011).

This view is consistent with the concept that the Victoria Transport Planning Institute refers to as transit encouragement. According to VTPI (2015), transit encouragement incorporates various strategies aimed at giving discretionary travellers (those who have the option of driving) reasons to choose transit. Inter alia, such strategies include improved transit service, upgraded bus stops and stations, improved rider information and marketing programmes, Transit-Oriented-Development and TDM programmes for commute trip reduction (VTPI, 2015a, b; Transport Canada, 2012).

Similarly, some of the key attributes of Curitiba’s Bus Rapid Transit (BRT) system to which much of its world renowned success is owed, includes a simple route layout, frequent service, less frequent stops, bus signal priority, uniformity in buses and stations, coordinated land use planning and higher-capacity buses (Philipsen, 2015). Mimicking this strategy involves assessing the current state of the transit service and proposing measures for its improvement with the assistance of user surveys (current and potential riders). 3. Diego Martin, Trinidad – A Case Study Diego Martin is a flourishing suburban region, a short 12.4 kilometres in distance westward of the capital city of Port of Spain. It spans a land area of 127.53 square kilometres (DMRC, 2010) and is comprised of 46 integral communities according to the Central Statistical Office. The administrative boundary of Diego Martin stretches from the western Chaguaramas peninsula, eastwards to Cocorite, which straddles the Diego Martin / Port of Spain border. Diego Martin is physically bounded by the mountainous terrain of the Northern Range and the calm waters of the Gulf of Paria to the south. These geographical features influence whether, how, and the level of transit service that is supplied.

This region is home to a resident population of 102,340 persons (CSO, 2011). Of particular importance to this research is the large vulnerable population (51% women, 27% children aged 19 and under, 17% elderly and 4% disabled) for whom special requirements are necessary. The main land uses in order of prevalence are residential, commercial, and to a lesser extent agricultural and industrial. Settlements follow a linear pattern along the region’s arterial roads with noticeable evidence of outward sprawl into the environmentally sensitive hillsides.

There is a high level of unemployment within the region. The last census recorded that less than half of the population (44%) was employed. Unemployment has been shown to be directly related to the level of perceived and actual crime and violence in these communities. Evident are vast disparities in socio-economic background


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amongst the communities of Diego Martin, varying from tremendously wealthy to extremely poor. Similarly, there are communities known to be “hotspots” for crime and violence juxtaposed to areas of no or low-risk criminal activities. Hence, this region is served by a multimodal public transportation system inclusive of buses, maxi taxis, and taxis. Table 2 provides a comparative description of the transport modes.

Table 2. Description of Diego Martin’s Public Transportation Mode Features

Bus

state-owned fixed-schedule (time and route) maximum carrying capacity= 40 seated, 20 standing lowest fare ($3.00 to general public, senior citizens and uniformed school chidlren free)

Maxi taxi

privately owned no fixed schedule maximum carrying capacity= 25 (large) and 13 (small) second highest fare ($4.00 from Diego Martin to Port of Spain and vice versa)

Taxi (Hired "H"

and Private-hired

"PH")

privately owned no fixed schedule maximum carrying capacity= 4 highest fare ($5.00 from Diego Martin to Port of Spain and vice versa)

The only state regulated, fixed schedule, high passenger capacity mode is the bus/ transit. A total of 17, 626 persons, 17% of the population, were recorded as having vehicles for private use. Thus, 83% of the population is public transport- dependent. 3.2 Research Approach Adhering to the principles of positivistic research, inferences made within were derived from data obtained via experimental testing and analysis of information retrieved.

Whilst quantitative data (traffic data, travel time data and statistics) is generally used to substantiate claims and theories, persons’ perceptions and feelings toward the transit service is of major relevance to this research. Thus, in order to carry out a comprehensive study that encapsulates all issues related to transit connectivity, a combination of both quantitative and qualitative data was collected, employing appropriate methods to acquire such. Research for this study was accomplished via both primary and secondary data collection, utilising a combination of both qualitative and quantitative data collection methods in efforts to produce a holistic study. Secondary data collection involved the review of land use plans, maps, reports and other relevant material concerning land use and transportation development for the study area. Primary data collection targeted three main categories- traffic data, the transit service, user perception of the overall transportation system. Table 3 provides a brief description of the methods employed in the acquisition of primary data.

Table 3. Data Collection Methods Employed in this Study

Data Type Method Description Rationale

Traffic Volume Count

Total number of vehicles entering and exiting Diego Martin via arterial roads counted for one hour during all three peak traffic flow periods of the day.

To determine travel demand.

Transit Travel Time and Delay

Survey

Data collector aboard transit vehicle noted (time) length of journey in and out of Diego Martin, as well as all delay (stop for more than ten seconds) occurences and reasons for such.

To determine average length of journey entering and exiting Diego Martin and reasons for delay.

User Perception Survey

Total of 30 mixed questionnaires directly issued via strategic random sampling to public transport users among Diego Martin residents.

To gain insight on the travel needs of, and perception of the transit service held by commuters.

Detailed Observation

Observation of the transit service carried out over five-day period at varying times of day.

To examine the transit service in its regular operating element in order to gain first-hand experience and a better understanding of the commuters' plight.

Quantitative

Qualitative

Data Collection Methods Employed in Study

4. Findings and Analysis This study seeks to improve the overall efficiency of the existing transit system by effecting modal shift from private vehicle to public transit. In order to recommend suitable strategies, it is important to understand 1) the influence of land use on sustainable transport development, 2) the bus service (transport supply), and 3) the commuters’ travel behaviour (transport demand). 4.1 Land Use and Transport As made evident by national document in the form of the National Physical Development Plan of 1984, in earlier times, land use planning was focussed on decentralisation strategies in the form of developing “growth poles.” The objective was to lessen the physical and economic burden of human and vehicular congestion in and around the overcrowded capital city of Port of Spain. Three basic spatial strategies were employed - Planned Concentration, Dispersal and Dispersed Concentration (NPDP, 1984). This trending outward spread and ‘leap-like’ action of communities resulted in two things worthy of mention: - 1) the proliferation of urban sprawl and 2) increasing distance between communities and the central public transportation system. Disadvantaged persons residing in areas where public transport was not available become ‘forced’ car owners in order to facilitate their mobility needs. This created difficulty for the provision of transportation as communities became increasingly isolated. Additionally, informal settlements through squatting have spiralled out of control, exacerbating sprawl and further challenging the public transport system’s ability to provide accessibility and mobility.

At present, primarily functioning as a dormitory settlement, Diego Martin generates numerous home-based trips. This has resulted in the development of three peak periods of traffic flow during the day - with two of considerably heavier traffic flow. Given these peak periods, the length of time taken to enter and exit vary according to the time of day. It was detected that even


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within the morning (i.e., from 6:00 to 8:00 am) and evening (i.e., 4:00 to 6:00 pm) periods, which are the heavier times of traffic, there are variations in the intensity of traffic congestion experienced. The shortest periods of travel are within the earliest and latest segments of the morning and evening peak periods. Interestingly, the main cause of transit delay service was found to be vehicular congestion. 4.2 The Bus Service Survey data shows that Diego Martin’s commuting population is primarily comprised of school students and employed persons. An average of 85% of the commuters’ destination is Port of Spain and beyond. Furthermore, 83% of the population do not have access to a private vehicle. This indicates that public transportation demand is highest during the peak morning and evening period which coincide with the standard hours of operation for most schools and places of employment. Transit is the only mode that will sufficiently provide easy mobility for such a magnitude of persons. However, the region is currently underserved by transit.

Diego Martin’s population is 102, 340 (CSO, 2011). The general public: private vehicle usage ratio in T&T is 30:70. This means that an average of 30, 702 persons rely on public transport. The bus service operates on an hourly basis along one central route (Port of Spain – Diego Martin). A total of 16 trips are made between the operating hours of 6am and 9pm. At maximum carrying capacity, the bus transports 65 passengers (45 seated, 20 standing). Thus, the maximum number of passengers that can be transported daily is 1040. This translates to a mere 3% of public transport commuters, thus showing that the current service is unable to adequately provide for the mobility needs of such a population size.

In terms of the quality of the service, the bus was found to be punctual but inconsistent in its operations. Sore points of the service include limited accessibility, low frequency, poor service area coverage, slow service, malfunctioning vehicles and poorly maintained bus stop facilities. In comparison to other transport modes, the bus has the lowest fare which makes it the cheapest and thus most affordable of modes. However, this feature does not work in favour of the bus service.

Being the cheapest mode compounded by having the lowest ridership makes the bus service unprofitable and more of a financial burden borne by the state. Being a service of high economic loss makes it difficult for the responsible authority to justify further financial investments and often undergoes budget cuts instead. Without financial resources to carry out upgrades to the service, the state of the bus service suffers continuous deterioration. In order to secure investments for upgrades, the transit ridership has to increase. However, commuters will not gravitate towards the bus service in its current dysfunctional state unless the love for the automobile is

broken or they are faced with no other option. All of these factors combined have created a long-lasting negative image of the bus service which pervades despite attempts to improve the system. This is reflected in the survey results which showed that 83% of the respondents were unsatisfied with the current level of service. However, there seems to be hope in the fact that 78% of the survey respondents stated that they would make transit their preferred transport mode if the punctuality, frequency and speed issues were rectified. 4.3 The Commuter A hierarchical structure in relation to transport mode prevalence and preference was detected within the transportation system. Private vehicles occupy the highest rung while the bus, which accounts for 10 percent of the modal split, occupies the lowest. Interestingly, as shown in Figure 2, the preferred mode of transport was found to be directly related to the age of the commuter.

Figure 2. Preference of Mode of Transport in Relation to Age of Commuter

The most popular transport mode (taxi) is shown to be preferred mainly by persons between the ages of 26 to 45 years old while the least popular mode (bus) is generally used by persons over 65 and under 18 years old. It must be noted that the 26 to 45 age category is the young working population who are more inclined to purchase personal vehicles for varying reasons and thus have the potential to further contribute to transport challenges. It would therefore be necessary for transit to attract such commuters in order to prevent further increase in private vehicle usage. 5. Discussions Three (3) major factors have led to the downfall of the transit system. These are:

1. Uncontrolled growth of dispersed low density, single-use residential communities, thus increased population, physical size and number of communities;


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2. Failure to upgrade the transportation system to match the rise in population, as well as the change in form and function of the region;

3. Increased automobile ownership among the population due to lowered vehicle purchasing cost.

In order to sustainably provide transit connectivity, a major hindrance in the form of the population’s travel culture, must be changed towards becoming more accepting of, and open to transit usage. Hence, the average commuter’s needs are simple. The commuter must:

1. be able to get to their destination quickly with minimal interruptions;

2. be assured that transport can be accessed when required; and

3. be allowed the ease of usage of any transport mode. However, Diego Martin’s population has been

conditioned into erroneously believing that automobile travel is the best option. This misconception and aversion to public transit has been driven by a few factors which include:

1. experience(s) of poor transit service quality, 2. difficulties in accessing public transport, and 3. cultural influence and the possession of a car being

revered as an indication of economic success. It is recognised that non-transit modes have filled a

void created by the lack of proper public transportation. To fixate on the apparent competition between public and private transport is to overlook the numerous benefits transit has to offer. However, despite upgrades to the transit service, the inability of the authorities to improve in areas that matter to the public has been unable to secure commuters’ buy-in, upon which the success of achieving sustainable transit connectivity is hinged. Commuters gravitate towards the mode of transport that guarantees what are most important to them- speed, reliability and convenience in this case. Their unwillingness to change is attached to the transit service being considered less than the existing preferred mode of transport.

The very low regard with which the bus system is treated by the authorities is doing a disservice to the population; since transit is the best mode of transport to cater to such a large population. There is also a social value that is provided by transit that ought not to be overlooked. More than a mechanism facilitating mobility, the transit environment represents the colourful cosmopolitan society that is T&T. Improved transit connectivity is in no way a panacea for all transportation ills, however this paper strongly argues that it is definitely a move towards sustainable transportation and development.

5. Recommendations Previous failed attempts at fixing transport problems have proven that there exists no single solution to the multi-faceted dilemma that is the current transport system. The

future of sustainable transit connectivity and achieving the highly desired sustainable transportation depends largely on the integration of land use and transportation planning. Thus the strategies developed and presented herein are designed with such goal in mind. Some of the strategies deal specifically with the land use aspect while others target the transit service. However, the proposed strategies were developed based on the practicality, ability to be implemented, and their relevance to the current economic climate in T&T. 5.1 Land use 5.1.1 Plan creation and update of old plans A long-standing hindrance to T&T’s development is the prevalence of and reliance on outdated plans. Both national legislative documents relating to transportation development – the 1984 National Physical Development Plan and 1967 National Transportation Plan- have been in existence in excess of thirty years and have not once been officially updated. Due to the existing plans no longer reflecting the current development trends, use of these plans to guide development are as impractical as it is counterproductive. Such archaic plans, while they are not entirely obsolete, are insufficient to guide the development at the rapid rate at which it is occurring, far removed from the time of the plans’ adoption. In order to have better manage development going forward, a firm commitment to plan revision and creation, as well as policy formulation must be established and adhered to. Additionally, a local connectivity plan should be developed for Diego Martin to further address issues specifically related to the realisation of sustainable transit connectivity. 5.1.2 Revision and amendment of setbacks, zoning and

development standards. Some of the existing standards need to be reviewed in terms of their relevance to current development trends. It is recommended that amendments should be made where possible, for example, to those that can be tweaked to address the current situation. However, those that are found to be obsolete, counterproductive, or no longer applicable such as those that encourage traffic congestion should be revoked.

5.1.3 Design with transit in mind Public transit should be promoted as the main transport mode in existing and future developments. Thus ensuring communities have simple, easy access to, and hassle-free use of the transit system. This must be given a high priority. Providing accessible transit has the potential to reduce automobile dependency which has been shown to be a major culprit in undermining the transportation


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system and rendering it unsustainable. Ultimately, deciding between private and public transport is left entirely up the commuter. However, a notably reliable, well-working transit service can become the best alternative to private vehicle use. Future development in areas within close proximity to the transit route should favour mixed-use, medium-high density housing as opposed to uses that are less likely to generate transit usage. Prohibition of automobile-oriented uses in such areas. 5.2 Transit Service The following strategies address the five (5) major areas that would influence on the quality of transit service provided. 5.2.1 Network planning and services 1. Re-alignment and expansion of route. A major

drawback in terms of service coverage is that Diego Martin’s current bus route simply follows the arterial Diego Main Road entering and exiting the region with a minor switch from main road to highway along part of the route. In order to widen the transit supportive area and serve a larger catchment area, the transit route has to be re-aligned and expanded. Only then will it be able to cater for those communities that are completely isolated or partially connected to the service. Figure 3 presents a comparison between the current and proposed route re-alignment and expansions, from Map 1 to Map 2. It shows the increase in the transit supportive area (shaded white) as a result of the re-aligned and expanded route.

Figure 3. Comparison of Transit-Supportive Area between Current

and Proposed Bus Routes 2. Rescheduling of service, increase in speed, and

frequency. Presented in Table 4 is a proposed rescheduled three-tiered bus service comprised of a local, limited-stop, and all-stop bus. This strategy

using three (3) bus types of varying carrying capacity and speed, along three individual routes simplifies the transporting while increasing the speed and frequency at which the population is transported. The maximum desirable waiting time for a transit service is 15-20 minutes, not 30 minutes and more as in the case of Diego Martin. In order to increase the frequency, the speed at which the bus travels has to be improved. The increase in total number of passengers transported per hour should provide a viable solution for overcrowded taxi stands and unavailability of transport modes.

Table 4. Proposed Three-Tier Service

Time Bus Type Route Speed Reason

6:00 AM Ciao All- stop MediumFewer persons commute at earlier hours, less demand for transit, adequate size of vehicle.

6:20 AM Articulated Limited- stop High

Highest transit demand at this time. High capacity, high speed bus more appropriate to maximise ridership and transit usage.

6:40 AM City service Local LowInter-community service extended to residential communities isolated from tranit service.

Firs

t hou

r

5.2.2 Bus stops and stations 1. Renovation and uniformity of bus stops and stations.

Bus stops, shelters, stations and terminals need to be enhanced to improve the image of the transit service and boost ridership. For increased visibility and easy identification, there should be uniformity in the design and style of the bus stop signs and sheds.

2. Strategic placement of bus stops for better traffic flow. Badly placed, as well as an abundance of bus stops between short distances would have adverse effects on traffic flow. The current locations of bus stops should be reviewed to determine whether they are necessary for the efficient functioning of the bus service. It is recommended that spatial analysis techniques be employed in identifying optimal locations for these stops.

3. Placement of schedule and route information at all bus stops and stations. Information about the bus service should be made readily available via possible means. This should allow captive and choice riders a clearer understanding of, and familiarity with the service and the routes taken. Persons are more inclined to use a service whose route they are familiar with.

5.2.3 Branding and Marketing 1. Social marketing. Changing the population’s travel

behaviour has the potential to effect a reduction in transportation problems. Social marketing should be considered as an area for future research. This is proposed in light of the deluge of negative comments received from the population on the current transit


57

service, compounded by their unapologetic loyalty to automobile transport. Humans tend to gravitate towards the popular. Prominent persons in society such as radio personalities, local “celebrities” and other well-known public figures can be enlisted in the promotion of public transit. Their popularity can be capitalised on, to encourage others to follow suit. Several persons felt relatable to recent images of a current Minister of Government captured using the public ferry. This gave persons a sense of being able to relate to those in authority. Government officials, businessmen, regular people, families can all be involved in the promotion of public transit as the preferred transport mode. This should yield an increase in ridership.

2. Better dissemination of information. A major downfall of the bus service is commuters not having easy access to information for proper journey planning. The use of information technology for information dissemination should be implemented. Android phone applications and programmes can be created giving real-time information on the schedule, routes and location of buses at any given time. This would require buses to have Global Positioning System (GPS) devices installed to facilitate such information being retrieved. This should also be able to assist with determining and monitoring the efficiency of the bus system.

3. Advertising campaign and initiatives. Innovative measures to increase ridership should be sought and implemented. For example, catchy television commercials can be used to show the possibilities of an enjoyable side to transit. Any method being implemented must be tailored to the suit the culture and lifestyle of the population being targeted.

5.2.4 Right-of-way and Transit Priority 1. Road space reallocation- the creation of a reversible

peak-period transit lane. During the peak morning and evening periods, the traffic lane of higher intensity on the Diego Martin main road should be transformed into a transit lane restricting usage of other types of vehicles during such time. The opposite should remain untouched and open for usage by different modes. The intention for such is to cater to the population at times of high demand in the direction of heaviest traffic flow. In the morning period between the hours of 6:00 to 8:00 am, all eastward bound (from within Diego Martin to outside Diego Martin) non-transit vehicles should be required to exit from the main road and proceed onto the highway. In the evening peak period between the hours of 4:00 to 6:00 pm the westward bound (into Diego Martin) lane should be strictly for transit usage. The lanes should be reverted to its normal use outside of peak hours. Traffic wardens should be used to supervise the usage of this lane and ensure compliance of drivers during such time.

2. Designated bus lane. The outermost right lane of the Diego Martin highway should be converted into a lane restricted to bus use. This should allow the free flow of the bus without competition for road space from other transport modes.

5.2.5 Transit Vehicle 1. Equip vehicles with Wi-Fi internet service. Business-

type commuters can keep up-to-date with their daily happenings by having easy communication and access.

2. Equip buses with electronic card swipe or off-payment. This should reduce time spent in entry process. A Travel Card service has already been implemented for some routes. These cards should be converted to electronic payment cards and extended to the Diego Martin buses as well.

3. Disability-friendly buses to be used. Persons faced with difficulties towards physical activity should not be excluded from using the service. Buses with easier entry and exit procedures (no steps) should be used to save time. At-grade entrance should be considered as it has proven to reduce time spent boarding and alighting the vehicle.

5.3 Cost and Evaluation This is by no means an exhaustive list of strategies. The recommendations were selected to address particular issues highlighted within the study, most of which relate to boosting the service quality of the transit system. The relevance of the strategies would be evaluated based on their potential travel impact on the system and the commuters.

The scope of this paper does not extend to monetising the cost of the strategies but rather evaluates them based on their qualitative value in order to highlight their importance. Conventional economic evaluation models are believed to overlook the social value and benefits of transit impacts. This paper focuses on enhancing the overall commuter experience, hence the chosen method of evaluation. Table 5 shows a summary of the evaluation of recommended transit improvements 6. Conclusion Diego Martin communities are in dire need of an efficient transportation system. This paper provides innovative yet practical and implementable measures to improve the sustainability of the transit system and thus alleviate the current transportation problems. It is argued that existing resources and facilities should be utilised before engaging in more expensive plans of action that are not guaranteed to achieve the desired outcome. Recommendations and strategies were derived from careful consideration of the current economic climate, as well as the culture and lifestyle of the residents of the Diego Martin communities. The benefits of improved


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Table 5. Evaluation of Recommended Transit Improvements

Type of Transit ImprovementImproves

Service QualityProvides Basic

Mobility

Attracts Riders & Reduces Personal Automobile Travel

Increases Speed and/ or Punctuality

Re-aligned and expanded route, increased coverage √ √ √ √Rescheduled service with increased speed, frequency and hours of operation √ √ √ √Bus stops and stations renovated, uniformed in appearance, strategically placed to allow better traffic flow √ √Bus stops and stations furnished with route and schedule information √Well-marketed service √ √Better disseminated of information √Advertising campaign and initiatives √ √Reversible peak-period transit lane introduced √ √ √

Designated bus lane √ √ √Wi-Fi enabled vehicles √ √Electronic card swipe on vehicles √Disability-friendly vehicles used √ √Transit-Oriented Development that results in transit-supportive land use √ √ √

transit are many. Among them is a better quality of life for citizens. The value of transit to the sustainable development of communities and the society is of great significance, and must no longer be ignored.

References: Acker, V.V and Witlox, F. (2009), “Why land use patterns affect

travel behaviour (or not)”, Belgian Journal of Geography. Available at: http://belgeo.revues.org/8777 (Accessed on 16 February 2015).

CSO (2011), Trinidad and Tobago 2011 Population and Housing Census Demographic Report, Central Statistical Office, Trinidad and Tobago

Cervero, R. (1994), “Transit villages: From idea to implementation”, Access. Available at: http://www.accessmagazine.org/fall-1994/transit-villages-from-idea-to-implementation/ (Accessed on 13 July 2017)

DMRC (2010), Diego Martin Regional Corporation Spatial Development Plan 2010, Diego Martin Regional Corporation, Trinidad and Tobago

Feng, T. (2010), Transit Sustainability Guidelines, American Public Transportation Association. Available at: https://www.transit.dot.gov/sites/fta.dot.gov/files/docs/Transit_Sustainability_Guidelines_for_APTA_Sept_20_2010.pdf (Accessed on 14 July 2017)

ITDP (2016), Public Transport, Institute for Transportation and Development Policy, Available at: https://www.itdp.org/what-we-do/public-transport/ (Accessed on 06 January 2016).

Litman, T. (2014), Land Use Impacts on Transport: How Land Use Factors Affect Travel Behaviour, Victoria Transport Policy Institute.

OC Transpo (2011), 2011 Marketing Plan. Available at: http://www.octranspo.com/images/files/about_oc/transit_planning/marketing_plan2011.pdf (Accessed on 24 August 2016).

Philipsen, K. (2015), “Ten ways to improve bus transit use and experience”, Sustainable Cities Collective, blog post, 27 May. Available at: http://www.sustainablecitiescollective.com/klaus-philipsen/1074286/ten-ways-improve-bus-transit (Accessed on 14 May 2016)

Shankar, A. (2017), “Transit-oriented development may transform the future of Indian cities”, Financial Express Online. Available

at: http://www.financialexpress.com/money/transit-oriented-development-may-transform-the-future-of-indian-cities/634047/ (Accessed on 15 July 2017)

Sinha, M. (2017), TOD in India, Ministry of Urban Development, Government of India, Availiable at: https://www.slideshare.net/EMBARQNetwork/tod-in-india (Accessed 14 July 2017).

Transport Canada (2012) Improving Bus Service Modest Investments to Increase Transit Ridership. Available at: https://www.fcm.ca/Documents/tools/GMF/Transport_Canada/ImprovingBusService_EN.pdf (Accessed on 26 October 2015).

VTPI (2015a), Public Transit Encouragement, Victoria Transport Policy Institute. Available at: http://www.vtpi.org/tdm/tdm112.htm (Accessed on 11 January 2016).

VTPI (2015b), Transit Evaluation. Determining the Value of Public Transit Service, Victoria Transport Policy Institute. Available at: http://www.vtpi.org/tdm/tdm62.htm#_Toc135020070 (Accessed on 13 May 2016).

Walker, J. (2012), Human Transit. How Clearer Thinking About Public Transit Can Enrich Our Communities and Our Lives, Island Press/ Center for Resource Economics. Available at: http://link.springer.com.ezproxygateway.sastudents.uwi.tt:2048/book/10.5822%2F978-1-61091-174-0 (Accessed on 25 October 2015).

Authors’ Biographical Notes: Hawwa Hassan is formerly MSc Student of the Department of Geomatics Engineering at The University of the West Indies (UWI), St Augustine.

Rae J. Furlonge is Part-time Lecturer in Transportation Planning of the Department of Geomatics Engineering, The University of the West Indies, St Augustine. Dr Furlonge is also Traffic and Transportation Engineer and Managing Director of L F Systems Ltd, Trinidad

Bheshem Ramlal is Senior Lecturer in Geoinformatics, Cartography and Geomatics Engineering and Head of Department of Geomatics Engineering, The University of the West Indies, St Augustine.

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Abstracts of The 2016 APETT Annual Technical Conference (Theme: “Innovative Engineering Solutions for the Caribbean”, 23rd-24th June 2016)

The Association of Professional Engineers of Trinidad and Tobago

Page

1. Improvement of Operations at a Steel Manufacturing Melt Shop: Application of Lean Manufacturing Tools and Techniques 61 by Christopher Fullerton and Boppana V. Chowdary

2. Optimising the Fermentation Period of Trinidad and Tobago Cocoa Beans for Chocolate Production 61 by Ryan R. Roper, Trevor A. James, and Laura Lewis

3. Use of Satellite Images, Remote Sensing, LiDAR, GIS, Hydrological and Hydraulic Software, to Manage Environmental Resources 62 by Pramenath Narinesingh

4. Strategies for Developing Sustainable Transit Connectivity in Diego Martin 62 by Hawwa Hassan, Rae J. Furlonge, and Bheshem Ramlal

5. Improving the Storage of Electricity Produced by Renewable Sources 63 by Ashton Rogers

6. Some Examples of Innovative Projects in the Manufacturing Sector in Trinidad and Tobago 63 by Roger A. Camacho

7. Addition of Waste Polymers in Road Surfaces of Trinidad and Tobago 64 by Areo Hosein, Chris Maharaj, and Rean Maharaj

8. An Investigation into the Efficiency of Chlorinators in Preventing Biofilm Buildup in Seawater Cooling Systems at the Point Lisas Industrial Estate 64 by Andrew Castor and Pramenath Narinesingh

9. The Quadric-Surfaced Sludge Digester for Developing Caribbean Countries 65 by Navin Ramroop, Kiran Tota-Maharaj, Hua-Peng Chen, and Denver Cheddie

10. Improvement of a Cassava Harvester Using Triz 65 by Kristal Sookdeo, Robert A. Birch, and Edwin I. Ekwue

11. Creating the Optimal Product Formula for Use by a Heavy Clay Block Manufacturer 65 by Roger Mylan, Rean Maharaj, and Chris Maharaj

12. Reuse of Slag in the Surface of Road Pavement 66 by Cheryon Morin, Rean Maharaj, and Chris Maharaj

13. Adsorption of Greenhouse Gases from Industrial Flue Gases 66 by Adsorption of Greenhouse Gases from Industrial Flue Gases

14. Life Cycle Cost Analysis of Vapor Compression Cooling Versus Vapor Absorption Cooling for Chiller Plant: A Case Study 67 by Darryl Joseph, Keivin Reece, and Mikhail Kydd

15. Municipal Wastewater Treatment and Associated Bioenergy Generation using Anaerobic Granular Bed Baffled Reactor 68 by Kiran Tota-Maharaj, Joseph Akunna and Denver Cheddie

16. Foundations and Floors on Expansive Clays and Compressible Soils: Post Tension Alternative 68 by Bill Ramrattan and Brendan Inniss

17. Earthquake Loss Estimation in the Caribbean 69 by Ilias Popadopoulos, and Machel Higgins


Vol.45, No.1, July 2017, pp.59-77

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18. Design and Development of an Anatomical Model: Application of CAD and Rapid Prototyping Principles 69

by Nishkal George, Boppana V. Chowdary, and Fahraz Ali

19. The Design of a Children’s Playground Kit to Introduce Design Thinking Through Free Play 69 by Kiran Ragoo, Umesh Persad, and Chris Maharaj

20. Testing Three Cardiovascular Disease Risk Prediction Models for the Trinidad and Tobago Population 70 by Amalia Hosein

21. An Android Application for Detection and Self-Monitoring of the Diabetic Foot Ulcer 70 by Keri Gobin, and Karen Louison

22. Geographical Distribution of Road Traffic Fatalities in Trinidad 71 by Chavin D. Gopaul

23. Establishing a New System of Biomedical Technology Assessment in Trinidad and Tobago 71 by Natasha Ramroop Singh

24. Proposal for the Introduction of a Plant Extracts Industry in Trinidad and Tobago 72 by Sharad Maharaj, Marian J. Watson, Rosemarie Skeene, and David R. McGaw

25. Plastic Waste to Petrochemical Feedstock 72 by Jeffrey V. Smith, Sydney Thomas, Lebert H. Grierson, and Alan J. Harper

26. Industrial Symbiosis and Waste minimisation in the Caribbean: Waste Tyres to Petrochemical Feedstock 73 by Maria Kesse, Lorraine Sobers and Alan Harper

27. Expanding Opportunities for Organic Waste Producers Through Anaerobic Digestion: A Case Study in Moca, Province of Espaillat, The Dominican Republic 73 by Kamel Singh

28. Radiation Shielding Parameters of Concrete Made with Electric Arc Furnace Slag Aggregates 74 by Davatee Maharaj, and Abrahams Mwasha

29. Design of a Special-Effects Wrist-Mounted Flamethrower 75 by Kathryn Maharaj, Chris Maharaj, Umesh Persad

30. The Engineer in the Fourth Industrial Revolution 75 by St. Clair A King and Ronald De Four

31. What Does COP21 Mean for Engineering in the Caribbean? 76 by Lorraine Sobers and Selwyn Lashley

32. Developing Software Objects to Mimic Real World Objects in the Design of Water and Sewer Systems 76 by Rheal Thomas, Donica Mahabir and Clint Sutherland

33. The Advanced Geophysical Monitoring Network of the Eastern Caribbean 77 by Lloyd L. Lynch and Chan Ramsingh

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1. Improvement of Operations at a Steel Manufacturing Melt Shop: Application of

Lean Manufacturing Tools and Techniques Christopher Fullerton1 and Boppana V. Chowdary2

1ArcelorMittal Point Lisas Ltd, Trinidad and Tobago, West Indies 2Department of Mechanical and Manufacturing Engineering, The University of the West Indies, St Augustine, Trinidad and Tobago,

West Indies Abstract: This study used a local steel manufacturer’s case to demonstrate the benefits of lean tools and techniques. In this regard, an in-depth literature review was performed to identify the application of lean principles to steel manufacturing industry. Global best practices were also looked at for benchmarking of steel manufacturing operations. Value Stream Mapping (VSM) tool was used to identify the process wastes. Cause analysis tools such as fish bone and 5-Whys were also developed for analysis of the selected steel-melt process. Future VSM chart was then developed to demonstrate the potentiality of the proposed lean strategies. The derived lean manufacturing benefits were validated at the end. The study identified the process wastes in the selected steel melting shop and helped the company to improve production by 22%, reduction in lead time by 37% and work in progress (WIP) by 77%. The study results will benefit the company which had direct impact on the overall efficiency of the organisation and also benefit the customer with quick delivery of product at lower cost. Keywords: Lean Manufacturing, Operations Improvement, Value Stream Mapping

2. Optimising the Fermentation Period of Trinidad and Tobago Cocoa Beans for

Chocolate Production Ryan R. Roper1, Trevor A. James2, and Laura Lewis3

1,2CADPEC Limited (Trinidad), Trinidad and Tobago, West Indies 3Renge Educational Services, Trinidad and Tobago, West Indies

Abstract. Trinidad and Tobago possesses, arguably, the finest cocoa beans globally. During the nineteenth century, the country was one of the largest producers of cocoa in the world and a rich cocoa plantation heritage still exists today. Many cocoa estates around the country remain viable despite a lack of care due to a cultural shift away from general agriculture and food production. This drastic shift that threatens the rich, local agricultural tradition is due to a number of reasons, the major of these being the growth and expansion of the oil and gas industry in Trinidad. While current annual production of cocoa ranges between 400 and 600 metric tonnes, the potential annual production capacity is circa 350,000 metric tonnes. This potential is due to the existence of dormant cocoa estates around Trinidad and Tobago that can, for the most part, be revived. This re-vitalisation effort is unlikely without a paradigm shift in the way cocoa and cocoa products are currently cultivated, processed and valued. To achieve this paradigm shift, a firm understanding of cocoa, its characteristics and potential products should be developed and recorded. Once the characteristics of the commodity are more fully defined and understood, particularly as it relates to the local varieties of cocoa, focused research that aims to develop niche products can be progressed, branded and marketed as unique, high quality items. This study relates specifically to the production of dark chocolate from cocoa and further developing the data available to local cocoa farmers and chocolate producers. A vital step in terms of readying the bean for chocolate manufacture is the fermentation process. Fermentation is a key to the development of the robust flavours and delicate aromas associated with high quality chocolates. The focus of this study is cocoa bean fermentation and how various lengths of the fermentation period might affect the flavours, aromas and texture of a resultant bar of 70% dark chocolate. Our research measured temperature, pH and the refractive indices of fermented cocoa beans at discrete intervals over a period of 11 days, to determine which fermentation period produces the maximum cocoa butter content and the best “tasting” chocolate bar. Keywords: Chocolate Production, Fermentation, Trinidad and Tobago

3. Use of Satellite Images, Remote Sensing, LiDAR, GIS, Hydrological and

Hydraulic Software, to Manage Environmental Resources Pramenath Narinesingh

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Department of Civil and Environmental Engineering, The University of the West Indies, St Augustine, Trinidad and Tobago, West Indies; E-mails: [email protected]; [email protected]

Abstract. Data is the backbone of planning and development. However, thus far not sufficient use has been made of the present technology to capture and assemble data on our natural resources, and to plan our development and restoration efforts towards a sustainable future. We must realise that sustainable development includes growth that meets the needs of all without endangering the natural resources needed for the future. Therefore, it is essential to consider both conservation and the restoration of threatened resources including soil, water, forest, wetlands, reserves, wild life, biota and land. Restoration does not imply returning to a static point in the past but an adapted present condition that will continue to provide the ‘threatened’ services. Annual reports identify dangerous trends in our environmental resources in qualitative terms but quantitative values are often absent, which provides an avenue for neglect. Known resources are readily listed and conservation measures developed and implemented with limited and incomplete information. However, there is much that we still need to learn about our interdependent relationship with the environment. Furthermore, with technological advances we continue to improve our understanding of our relationship to the earth and its response to our interaction. The Caribbean must take the step forward and grab the present technology as a community and make efficient use of our natural and built resources; water, air, forest, coasts, land, sea, infrastructure development, and industry. The remote sensing technology and the advancement in Geographic Information System make it easy to capture environmental data rapidly, almost anywhere on the planet, and to accurately process it into useful information. This advancement is being used widely outside the Caribbean Islands while we continue to bury significant sums of monies in projects with a paucity of data. The absence of adequate data promotes non-sustainable planning solutions and less than efficient development. Through the integration of information from Satellite and Earth Observation Systems from around the world, better informed decisions may be made regarding biodiversity and ecosystem sustainability, disaster resilience, food security, sustainable urban development, and water resources management given the dramatic fluctuation in weather. Notwithstanding our best efforts to forward sustainable terms of reference for projects, we fail to produce the required results due to the lack of data at the required level of detail or length of record. This presentation describes briefly some sources and environmental data types collected by satellites. It also shows several applications of the technology including rapid and accurate data collection, the study and identification of critical areas on rivers threatened by erosion and needing maintenance, the potential movement of property boundary along rivers, land use change and increase in discharge, and potential severe flooding and drought. Keywords: Satellite Images, Remote Sensing, Environmental Resources

4. Strategies for Developing Sustainable Transit Connectivity in Diego Martin

Hawwa Hassan1, Rae J. Furlonge2, and Bheshem Ramlal3 1,3Department of Geomatics Engineering, The University of the West Indies, St Augustine, Trinidad and Tobago,

West Indies; E-mail: [email protected] 2L F Systems Ltd, Trinidad and Tobago, West Indies; E-mail: [email protected]

Abstract. Diego Martin communities have long suffered from poor transit connectivity which has, for many years, created difficulty for residents engaging in essential daily activities. This deficiency of the transit system arose as a consequence of shortsighted land use planning policies, rapid population growth and uncontrolled increase in automobile ownership. This paper seeks to provide innovative yet practical and implementable measures to alleviate the current transportation problems and thus improve the sustainability of the transit system. Throughout the paper, it is promoted that existing resources and facilities should be utilised before engaging in more expensive plans of action that are not guaranteed to achieve the desired outcome. Data was collected from both primary and secondary sources on three major aspects affecting transit - land use, transport demand, and transport supply. Each factor has been analysed in terms of its ability to influence transit and the contributing role in developing the current transit system and its problems. Results show that the main factor hindering the connectivity and sustainability of the transit system of Diego Martin is the residents’ travel behaviour, ignited by their obsession with automobile ownership and usage, compounded by the poor quality and level of service of the transit service. A hierarchy based on commuter preference exists within the transport system where private transport occupies the highest rung and transit occupies the lowest. Residents have been found to be discouraged from using the transit service due to its failure to function properly and adequately. The overwhelming negative responses received from commuters regarding their perception of the transit service indicate that improvements in its overall performance is not enough to shift ridership from personal vehicles to transit usage. The need for new ideas is evident. This conclusion has informed the recommendations and strategies proposed. These strategies were derived after careful consideration of the current economic climate, as well as the culture and lifestyle of the residents of the Diego Martin communities. The authors of this paper are of the firm belief that the value of transit to the sustainable development of communities and the society on a whole, is of great significance and must no longer be ignored. Keywords: Sustainable Development, Transit Connectivity, Diego Martin communities

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5. Improving the Storage of Electricity Produced by Renewable Sources

Ashton Rogers

The University of Trinidad and Tobago, Trinidad and Tobago, West Indies; E-mail: [email protected] Abstract. Electrical power generation from renewable sources has been increasing worldwide especially with the need to address issues of global warming, air quality deterioration, oil spills, acid rain, chemical water pollution, and climate change, which are the major hazards of fossil fuel power generation. Currently, renewable energy accounts for 30% of global electrical energy production, however, the Caribbean only produces 8% of its electricity from renewable sources despite having an abundance of solar, wind and tidal energy. The major problem with electricity production from renewable sources is its intermittent supply, which presents a significant challenge for load balance maintenance for power grid stability and reliability. This paper seeks to review the most recent advancements for electrical energy storage (EES) in the form of hydrogen. Solar fuel cells and water electrolysis are the two main technologies for producing hydrogen. The most recent innovation to solar fuel cell technology is the recent advent of artificial photosynthesis, which uses cheap earth-abundant catalyst (cobalt and phosphate) to split water into hydrogen and oxygen. Alkaline water electrolysis is the easiest and simplest method for hydrogen production. The modern zero gap system in the Chlor-Alkali electrolyzer introduces superior performance. Other improvements include the use of an ionic liquid electrolyte; electrolyte additives; increased pressure and temperature of the electrolyte; an ultrasonic field around the cell; optimised spacing between the electrodes; wide electrodes in an absolute vertical position; woven or porous sintered electrodes; a diaphragm for separating the electrodes; electrodes with embedded catalysts; and polymer/proton electrolyte membranes. These improvements are cost effective and overcome many of the disadvantages of earlier designs such as low efficiency, maintenance, durability and reliability. Although these improvements are very encouraging, further research is required to fully optimise alkaline hydrolysis systems for long lasting large industrial applications. Keywords: Storage of Electricity, Renewable Sources, Caribbean

6. Some Examples of Innovative Projects in the Manufacturing Sector in Trinidad and

Tobago Roger A. Camacho

Professional Engineer, Trinidad and Tobago, West Indies; E-mail: [email protected] Abstract. There is tremendous opportunity for Engineers in Trinidad & Tobago to create and execute innovative projects in their manufacturing companies. This is in spite of many traditional owners of small, medium and large factories being hesitant to invest in “local talent” due to the fear of failure and the “Colonial” attitude that LOCAL = BAD and FOREIGN = GOOD. These projects need not be massive undertakings that require huge capital investments, but small specialised designs that solve specific problems in the factory. In many cases, the innovative aspect of the design may involve the creative use of materials found in the scrap heaps of the companies. Other innovative solutions may not result in a physical technological device or system but by using a different approach or different method to solve a recurring problem. One of the objectives of this paper and presentation is to stimulate the engineering community and show to the national and regional manufacturing sector that innovative solutions to problems need not require huge sums of money to implement and higher technical degrees to conceive and analyse. Experience has shown that companies with the foresight and willingness to take the risk by implementing many small innovative projects and new ideas over time will have the competitive advantage over other manufacturers of similar products. This paper presents four innovative projects completed over the last few decades that were designed, built, tested and put into service in one factory in Trinidad and Tobago. In each project the following will be presented: (a) the problem that needed to be solved, (b) the design considerations, (c) the engineering and scientific principles used, and (d) the final device/system that was built or implemented. It should be noted that all the design and construction was done by local engineers and technicians. Maximum use was made of locally available or manufactured materials. Imported materials, equipment and devices were only used if they were not made locally. The first project describes a water saving solution that uses a chilled water air handling unit as a “cooling tower”. The second project describes how a four colour flexographic printing press was used to print five colours on an envelope machine. The third project describes the design of a system to detect the absence of a window patch on a window envelope that is manufactured on a “Web” envelope machine. The fourth project describes a management/administrative decision and system taken which eliminated the pilfering of tools from the factory. Keywords: Innovative Projects, Manufacturing, Trinidad and Tobago

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7. Addition of Waste Polymers in Road Surfaces of Trinidad and Tobago Areo Hosein1, Chris Maharaj2, and Rean Maharaj3

1,2Department of Mechanical and Manufacturing Engineering, The University of the West Indies, St Augustine, Trinidad and Tobago, West Indies; E-mails: [email protected]; [email protected]

3Process Engineering, The University of Trinidad and Tobago, Trinidad and Tobago, West Indies; E-mail: [email protected]

Abstract. Synthetic and natural polymeric materials play an essential and ubiquitous role in everyday life in Trinidad and Tobago. These materials include familiar synthetic thermoplastics such as Polyethylene Terephthalate (PET) used in the manufacture of plastic bottles and thermosets like rubber used in the production of automobile tyres. Since PET and shredded tyre rubber (crumb rubber (CR)) take a relatively long period to degrade naturally, the obvious disadvantage of its use is the environmental and ecological challenges it presents. These materials can often be seen along roadsides, in watercourses and in landfills where they take up large amounts of space. The reuse of these waste materials as a solution to mitigate such negative effects has engaged the attention of researchers over the years. Studies have shown that incorporating PET and CR into Trinidad Lake Asphalt (TLA) and Trinidad Petroleum Bitumen (TPB) binders have resulted in improvements of the rheological and mechanical properties of the polymer-asphalt blends. While the rheological studies provided promising results, information involving the influence of PET and CR in the actual road paving formula or Hot Mixed Asphalt which comprises of a 7% binder (75% TPB (60/70 Penetration) and 25% TLA) and 93% aggregate (limestone or gravel) mixture are limited. This study investigated the influence of PET and CR on the mechanical properties (measured by Marshall Stability and Flow studies) of the actual Hot Mixed Asphalt used in road paving in an effort to determine the optimal PET and CR content. The study revealed the optimal contents at 2% CR and 3% PET addition, thus providing supporting evidence that this process is a viable reuse option for these waste materials in Trinidad and Tobago. Keywords: Waste Polymers, Reuse, Road, Trinidad and Tobago

8. An Investigation into the Efficiency of Chlorinators in Preventing Biofilm Buildup in

Seawater Cooling Systems at the Point Lisas Industrial Estate Andrew Castor1 and Pramenath Narinesingh2

1PCS Nitrogen, Trinidad and Tobago, West Indies; E-mail: [email protected] 2Department of Civil and Environmental Engineering, The University of the West Indies, St Augustine, Trinidad and Tobago,

West Indies; E-mails: [email protected]; [email protected]

Abstract. At the Point Lisas Industrial Estate, water treatment programmes are often affected by the limitation of the availability of Sodium Hypochlorite from the electro chlorinator units and associated chlorinator cells. This limitation exposes the cooling system, the tower and the heat exchanger networks, to biological buildup that results in reduced heat transfer efficiency and biofouling of the system. To determine the factor or combination of factors that significantly affect the production of sodium hypochlorite by the chlorinator, the influent water from the Gulf of Paria was tested. The parameters investigated included seasonal variation of water quality (turbidity, pH, organic loading, ammonia concentration), rainfall, precipitation of Fe ions on the electrodes of the chlorinator units, chlorine demand, anions, cations, hardness and chlorinator efficiency. Sampling and analysis of the influent water for the parameters listed was undertaken in accordance with EPA and AWWA procedures. These factors are categorised as external to the mechanical equipment producing the hypochlorite. Parameters directly affecting hypochlorite production due to design of the unit were identified and classified as internalities. These parameters were monitored but not modified, therefore, the analysis was limited to the external factors. Analysis of the external factors consisting of rainfall, precipitation of ions, chlorine demand, alkalinity and anions (sulphates and chlorides) showed no significant correlation with the fluctuation in hypochlorite production. However, comparing the fluctuation of the applied current with the efficiency of chlorine production revealed a direct correlation. Thus, the source of the problem was identified to be the maintenance of an effective range of current supplied to the chlorinator to achieve the design output current range. Field tests proved that it is necessary to increase the current supplied by 9.1% in order to maintain the designed level of chlorine production. Keywords: Seawater Cooling Systems, Chlorinators, Biofilm, Water treatment

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9. The Quadric-Surfaced Sludge Digester for Developing Caribbean Countries Navin Ramroop1, Kiran Tota-Maharaj2, Hua-Peng Chen3, and Denver Cheddie4

1Department of Project Management and Civil Infrastructure Systems, The University of Trinidad and Tobago, Trinidad and Tobago, West Indies; E-mail: [email protected]

2Department of Engineering Science, The University of Greenwich, UK; E-mail: [email protected] 3Department of Civil Engineering, The University of Greenwich, UK; E-mail: [email protected]

4Utilities Engineering Department, University of Trinidad and Tobago, Trinidad and Tobago, West Indies; E-mail: [email protected]

Abstract. The quadric surfaced or egg-shaped sludge digester (ESD) has been widely accepted as efficient and cost effective to operate in secondary treatment of wastewater sludge. Its general shell form can be described as a revolution of a parabola with its tapered ends either curved or conical. Such a shape provides a greater surface area to volume ratio, whilst the plan area of the sludge is considerably small. This results in efficient scraping at the base of the tank thus producing a cost saving mechanism. Various studies on the dynamic response to earthquakes have been conducted via numerical and scaled earthquake simulation laboratory models. In previous studies, it was found that under favourable seismic performances using shake table testing, these sludge reactors withstood a multitude of dynamic responses found in seismic zones. Owing to the nature of the shape of quadric reactors, constructability requires specialised expertise and highly skilled labour which, for smaller economies come at a high price. This translates to a significantly higher cost of construction that is due mainly to the importation of specialised formwork and labour. The use of novel 3D printing technology can be utilised to replace traditional construction techniques and materials to achieve similar results. The versatility of 3D printing can create various forms. With this freedom, exploring morphologies for wastewater treatment plants can be conducted. A finite element analysis is performed on a cross-section of the shell with idealised microstructures with various iterations to determine the optimum forms for particular applied loads. Group efficiencies of these idealised microstructures will ultimately define a final shell cross-section which is then applied to a global ESD model for analysis. This paper outlines ongoing research, illustrating the benefits that a pilot-scale ESD can have on small island developing states and the Caribbean economic territories. Keywords: 3D Printing, Technology, Sludge Digester, Wastewater Treatment Simulation, Caribbean

10. Improvement of a Cassava Harvester Using Triz

Kristal Sookdeo1, Robert A. Birch2, Edwin I. Ekwue3

Department of Mechanical and Manufacturing Engineering, The University of the West Indies, St Augustine, Trinidad and Tobago, West Indies; E-mails: [email protected]; [email protected]; [email protected]

Abstract. The theory of inventive problem solving or “TIPS” is more commonly known as “TRIZ” an acronym that means the same phrase in Russian. TRIZ was developed by Genrich Altshller and his colleagues between 1946 and 1985. The theory is based on the hypothesis that someone sometime, somewhere, has already solved your problem or one that is similar to it. TRIZ is a problem solving method based on logic and data in which its central purpose is to thoroughly apply strategies and tools to find superior solutions that overcome the need for a compromise between two elements. In this paper we applied the TRIZ methodology to solve some of the challenges of a cassava harvester. These challenges included the increase of the working depth of cut and improvement in the soil loosening capabilities. The methodology was applied and changes were suggested on the curvature of the cutting bale, the rake angle and the overall rigidity of the implement. Tests were performed on the modified implement via simulations and actual field test. The test showed improvements in soil loosening resulting in increased field capacity and field efficiency as well as increased harvesting of cassava. Keywords: TRIZ Methodology, Field Capacity, Efficiency, Cassava Harvester, Trinidad and Tobago

11. Creating the Optimal Product Formula for Use by a Heavy Clay Block

Manufacturer Roger Mylan1, Rean Maharaj2, and Chris Maharaj3

1,3 Department of Mechanical and Manufacturing Engineering, The University of the West Indies, St Augustine, Trinidad and Tobago, West Indies; E-mail: [email protected]; [email protected]

2Process Engineering, The University of Trinidad and Tobago, Trinidad and Tobago, West Indies; E-mail: [email protected] Abstract. In order to address major quality defects such as cracking, excessive shrinkage and unsatisfactory product colour in

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the final brick product being produced by a major clay block manufacturer in Trinidad, the non-optimisation of block ingredients was investigated as the possible root cause for the defects. The effect of incremental deviations of the proportion of clay and sand to the original formulation on physical characteristics of compressive strength and modulus of rupture, and the aesthetic property of colour was measured. Twenty four variations were composed and briquettes of dimensions 12mm x 12mm x 50mm and 12mm x 12mm x 25mm were produced for the modulus of rupture and compressive strengths, respectively. Analysis of Scanning Electron Microscopy (SEM) and energy dispersive x-ray spectroscopy was conducted to measure the efficiency of mixing in the preparation of the blends along with the elemental composition and distribution at the surface of the samples. The results indicated that at the 95% confidence level, a 2.5% addition of clay to the original formulation resulted in a significant increase in compressive strength (89%) and modulus of rupture (57.5%). An improvement in the colour aesthetic was also observed. The SEM and elemental mapping studies indicated satisfactory mixing due to the presence of homogenous elemental distributions. The presence of aluminium atoms (from the clay material in the form of kaolinite) suggests that the added clay (kaolinite) facilitates increased inter-particle bridging, increasing adhesion and cohesion characteristics thus, improving compressive strength and modulus of rupture as observed in this study. Keywords: Brick product, Manufacturer, Scanning Electron Microscopy, X-ray Spectroscopy

12. Reuse of Slag in the Surface of Road Pavement

Cheryon Morin1, Rean Maharaj2, and Chris Maharaj3

1,3 Department of Mechanical and Manufacturing Engineering, The University of the West Indies, St Augustine, Trinidad and Tobago, West Indies; E-mail: [email protected]; [email protected]

2Process Engineering, The University of Trinidad and Tobago, Trinidad and Tobago, West Indies; E-mail: [email protected] Abstract. The production of slag, the glass-like by-product left over after the ferrous smelting process in the manufacture of iron and steel in Trinidad, presents disposal and environmental challenges. Research has demonstrated that the possibility of improving the utilisation of this waste material is an important way to resolve these problems and in particular, its use as a recycled raw material as a substitute for sand and limestone aggregates for road construction. The chemistry of the interaction of mineral aggregates with asphaltic materials ultimately determines the mechanical properties of the mixture and its suitability for engineering applications. Since asphaltic materials from different sources vary in chemical composition, these asphalt-aggregate interactions will vary and the properties of the mixtures thus cannot be generalised. A survey of the literature on the utilisation of slag as an aggregate with Trinidad asphaltic materials for road construction has produced limited results. This study investigated the influence of varying compositions of electric arc furnace steel slag (0%-20% of 3/4 inch sized aggregates) on the Marshall stability and durability (measured by accelerated weathering) of blends in an effort to determine the optimal slag content. Results revealed that the optimal slag content of 4% would increase the mechanical properties of road pavement having a stability of 8.85kN and a flow of 3.124mm. Keywords: Road Construction, Slag, Aggregate, Asphaltic Materials, Trinidad and Tobago

13. Optimising Conditions for Maximum Adsorption of Greenhouse Gases Using

Zeolite and Hydrotalcite in Packed Bed Columns Helena Ali-Victor1, and Valerie Stoute2

1,2 Environmental Studies Unit, The University of Trinidad and Tobago, O’Meara Campus, Lots 74-98, O’Meara Industrial Estate Trinidad and Tobago, West Indies; E-mails: [email protected]; [email protected]; [email protected]

Abstract. As a small island developing state, Trinidad and Tobago is particularly vulnerable to the adverse impacts of climate change such as those related to temperature increases, changes in precipitation, sea level rise, salt water intrusion and beach erosion. It has been argued, although not yet established, that the enhanced Greenhouse Gas Effect promotes global warming and that, in turn, impacts on the elements of weather, leading to the adverse effects of Climate Change. Typical industrial flue gases consist of Greenhouse gases, approximately 15% CO2, with trace amounts of Sox (<2000ppm) and NOx (<1000ppm), which would promote this effect. As of 2012, Trinidad and Tobago ranked second highest in the world in terms of CO2 emissions per capita. In 2010, 53 million tonnes of greenhouse gases were emitted from which the majority (80%) originated from the petrochemical and power generation sectors. Options, such as Carbon Capture and Storage (CCS), Renewable Energy (RE), Compressed Natural Gas (CNG), and Dimethyl Ether (DME) are being evaluated as alternatives to reduce this country’s carbon footprint. However, NOx and SOx are not prioritised as major pollutants in those studies. Therefore, this research targets these three major pollutants, CO2, SO2 and NO. The intention is to estimate and compare the optimum conditions for maximum adsorption of CO2, NO, and SO2 present in flue gases, using either zeolite or hydrotalcite in a packed bed column

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design; to estimate the capital, operating and energy costs of using a packed bed column design; and to determine its economic viability against more commonly used absorption technologies such as the MEA scrubbing system. In addition, methods by which the spent adsorbent could be treated in order to ensure that one form of environmental pollution is not swapped for another will be explored. Although actual experimentation is still in its initial assembly phase, the pilot design is expected to be operational by June 2016, after which substantial data should be collected. Response Surface Methodology, based on a Fractional Factorial overlaid with a Central Composite design method, will be implemented to optimise this adsorption process under changes of gas mixture ratios, flow rate, and adsorbent characteristics (chemical structure, packing size and depth) for each of several constant temperatures. Breakthrough curve analysis, kinetic studies and isothermal modelling are other key aspects to be included in the analysis, which would determine the maximum adsorption capacity over time, the gaseous component which has the greatest adsorption affinity, and the best fit of the empirical model with either the Langmuir or Freundlich isotherm models. Keywords: Greenhouse Gases, Adsorption, Industrial Flue Gases

14. Life Cycle Cost Analysis of Vapour Compression Cooling Versus Vapour Absorption Cooling for Chiller Plant in the Range of 50-400 RT: Case Study for

Trinidad and Tobago Darryl Joseph1, Keivin Reece2, and Mikhail Kydd3

1Energy Dynamics Ltd., Trinidad and Tobago, West Indies; E-mail: [email protected] 2Mechanical Engineering, The University of Trinidad and Tobago, Trinidad and Tobago, West Indies

3The National Gas Company of Trinidad and Tobago, Trinidad and Tobago, West Indies Abstract. In Trinidad and Tobago (T&T) air conditioning is an important utility, very much like electricity, water, gas, and telecommunication services which we have grown accustomed to; so much so that we expect a smooth, uninterrupted service when we switch on our AC system. The average temperature for the islands ranges between 26 -28°C with highs of 36.5-37.5 °C and relative humidity (Rh) averaging 70-80% in the rainy season. The American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE) in its guidelines, gives a thermal comfort range between 22-26 °C, with relative humidity (RH) between 30-60 %. Case in point, we see the importance for space cooling to maintain comfortable living and working conditions in the tropics. A study was performed to determine Life Cycle Cost Analysis (LCCA) for Vapor Compression Cooling (VCC) vs. Vapor Absorption Cooling (VAC). The study investigated whether VAC was more economical than VCC by comparing the life cycle cost (LCC) of chiller plant ranging in size from 50-400 RT. The Whole Building Design Guide (WBDG) defined LCCA as a method for assessing the total cost of facility ownership. It goes on to state that LCCA is a useful method to determine which alternatives are the most viable to offer the greatest net savings using a cradle to grave perspective. LCCA is a very versatile method of analysis, as it takes each detail into consideration in the comparison of equipment and facilities. This method provided useful insight into the economic feasibility of comparing and contrasting VCC and VAC cooling technologies. The VAC system studied was the direct-fired, double effect system which utilised natural gas as the heat source for the high temperature generator (HTG). The LCCA was done using Microsoft Excel and Building Life Cycle Costing (BLCC) software from the USDOE. Data for the study was provided by leading suppliers of VAC and VCC chiller plant on island and AC subject matter experts (SMEs). The LCCA compared acquisition, utilisation and disposal costs between the competing technologies to determine which offering would be more economical to implement. The life span for the equipment was taken as 20 years and LCCA considered interest and inflation rates to determine payback periods. Limitations of the work were in the form of (1) comparing efficiencies of the technologies, since the project was solely economical (2) technical parameters were not looked at to determine the varying Coefficient of Performance (COP) (3) overall customer satisfaction and the comfort of individuals (4) types of facilities where base and peak load operations varied for each facility and resulted in a varied operating profile and energy consumption for each type of technology. The results from the analysis showed that the VAC system was capable of being a feasible economic option to provide cooling for buildings. It also found that VAC systems had less environmental impacts when compared to VCC systems. Keywords: Life Cycle Cost, Vapour Absorption Cooling, Systems, Trinidad and Tobago

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15. Domestic Wastewater Treatment and Associated Biogas Generation Using Anaerobic Granular Bed Baffled Reactor (GRABBR)

Denver Cheddie1, Kiran Tota-Maharaj2, and Joseph Akunna3

1Utilties Engineering Division, University of Trinidad and Tobago, Point Lisas Campus, Trinidad, West Indies; Email: [email protected]

2Faculty of Engineering and Science, Department of Engineering Science, University of Greenwich, Medway Campus, Kent, United Kingdom; Email: [email protected]

3Urban Water Technology Centre, School of Science, Engineering & Technology, Abertay University, Dundee, Scotland, United Kingdom; Email: [email protected]

Abstract. This project assessed a pilot scale anaerobic granular bed baffled reactor (GRABBR) for domestic wastewater treatment at high organic loading rates (chemical oxygen demand ≥ 1100 mg/l) under varying temperatures with the associated biogas production. Two mesophilic temperatures were tested (25⁰C and 37⁰C) for steady-state conditions of organic removal rates. The measured effluent chemical oxygen demand (COD) and biochemical oxygen demand (BOD) were approximately 80 to 90 % less than the inflow organic loadings. At lower COD and BOD inflows, the reactor operated as a completely mixed system with most of the treatment occurring in the first two compartments. The GRABBR also showed very high solids retention with low effluent suspended solids concentration for all organic and hydraulic conditions. The applications of GRABBR as a single unit, two-phase treatment system could be an economical option, reducing the cost to achieve similar treatment goals for high strength wastewaters. The findings of this research suggest that the application of GRABBR is suitable for the treatment of multiple pollutants present in domestic wastewater, where each compartment acts as a specialised treatment stage with equivalent biogas production. Keywords: Wastewater Treatment, Biogas Generation, GRABBR

16. Foundations and Floors on Expansive Clays and Compressible Soils: Post Tension

Alternative Bill Ramrattan1 and Brendon Inniss2

1CPML Contractors Limited, Trinidad and Tobago, West Indies Abstract. The Industry continues to build foundations on marginal soils such as expansive clays or compressible soils using details that do not resist the shrinking and swelling of neither the expansive clays nor the compressibility of the soil. In Trinidad and Tobago, almost 70% of our surface geology contains soils that could be classified as expansive or compressible. Piles and raft foundations (without adequate details) have been found to be common types of foundations used to counter these soil factors. Post tensioning of foundations using unbonded pre-stressing cables have been found to be a very useful and economical alternative for counteracting the effects of swelling clays and settlement in compressible soils. A rational raft foundation properly engineered using unbonded post tensioning technology has been developed by analysing the soil parameters to provide an effective solution. In building and slab-on-ground construction, unbonded tendons are typically prefabricated at a plant and delivered to the construction site, ready to install. The tendons are laid out in the forms in accordance with installation drawings that indicate how they are to be spaced, what their profile (height above the form) should be, and where they are to be stressed. After the concrete is placed and has reached its required strength, usually 3000 to 3500 psi (“pounds per square inch”), the tendons are stressed and anchored. The tendons, like rubber bands, want to return to their original length but are prevented from doing so by the anchorages. The fact that tendons are kept in a permanently stressed (elongated) state causes a compressive force to act on the concrete. The compression that results from post-tensioning counteracts the tensile forces created by subsequent applied loading and the moment reversals caused by the swelling and shrinkage of the soil. This significantly increases the load-carrying capacity of the concrete. Keywords: Expansive Clays, Compressible Soil, Tension, Trinidad and Tobago

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17. Earthquake Loss Estimation in the Caribbean Ilias Popadopoulos1, and Machel Higgins2

1,2The UWI Seismic Research Centre, St Augustine, Trinidad and Tobago, West Indies; E-mails: [email protected]; and [email protected]

Abstract. The Caribbean region is a highly active area in regards to subsurface transformations. The eastern part of this region is a triple junction point between the North American, the South American and the Caribbean tectonic plate, creating an explosive geophysical environment with volcanoes and high occurrence of devastating earthquakes. Despite the geophysical procedures that are happening constantly, the region is facing an exponential development of infrastructure and population growth, increasing the exposure of the West Indies to seismic hazard. Given this exposure, it is necessary for all Caribbean governments and stakeholders to investigate and quantify the seismic risk of their respective regions. Seismic Research Centre has initiated the past years' several projects aiming towards the direction of identifying and quantifying the seismic hazard and risk for the region. Example of such work is the seismic risk assessment of the Kingston Metropolitan Area, Jamaica through the identification of the seismic hazard and use of the Earthquake Loss Estimation software Ergo-EQ (formerly known as MAEViz). Assessing building structure types in large areas is prohibitively expensive. In modifying Ergo-EQ we are able to statistically classify building structure type using widely available proxy data sets. Using the building structure type classifications, it is possible to assess damage due to seismic hazard. Another example is the Trinidad and Tobago Microzonation Project, funded by the Ministry of Planning and Development. The project aims to provide the resonance frequency and soil classification of ten major areas in the country, providing engineers with a useful tool with regards to civil construction. Several other projects are under design to cover the rest of the Caribbean region in terms of seismic hazard and risk, in an effort to help the civil community improve building practices. Keywords: Earthquake, Loss Estimation, Seismic Hazard, Risk, Building, Caribbean

18. Design and Development of an Anatomical Model: Application of CAD and Rapid

Prototyping Principles Nishkal George1, Boppana V. Chowdary2, and Fahraz Ali3

1,2,3 Department of Mechanical and Manufacturing Engineering, The University of the West Indies, St Augustine Campus, Trinidad and Tobago, West Indies; E-mails: [email protected]; [email protected];

[email protected] Abstract. The disciplines of engineering and medical sciences are progressively intertwined due to the rapid increase of technology for instructions of medical personnel. The training for medical practitioners requires provision of fully comprehensive knowledge of patient-specific anatomy that traditional models lack considerably. Rapid Prototyping (RP) technology, combined with Computer Aided Design (CAD) principles, has the ability to meet the situation by allowing fabrication of three dimensional (3D) anatomical objects which facilitates a firsthand view of the anatomical build of human body. This study explores the use of Genetic Algorithm (GA) on the design performance of anatomical CAD models. Experiments were conducted on the developed medical CAD model using Central Composite Design combined with Response Surface Methodology. It was found that the selected design approach was successful in producing a RP patella model resulting in 27% material savings, compared to a solid non-refined model and was deemed satisfactory for practical use. Keywords: Anatomical Model, Genetic Algorithm, Computer Aided Design, Rapid Prototyping

19. The Design of a Children’s Playground Kit to Introduce Design Thinking through

Free Play Kiran Ragoo1, Umesh Persad2, and Chris Maharaj3

1,3 Department of Mechanical and Manufacturing Engineering, The University of the West Indies, St Augustine, Trinidad and Tobago, West Indies; E-mails: [email protected]; [email protected]

2The University of Trinidad and Tobago, Trinidad and Tobago, West Indies; E-mail: [email protected] Abstract. This paper details the design of a mechanical playground kit that allows children to use their imagination, physical, cognitive and socialisation skills in assembling the elements. This research builds on constructivist approaches to creativity and

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imagination. The proposed design is envisioned as a learning resource that teachers can use to practically educate children about the principles outlined in the Science curriculum while ensuring the children have fun at the same time. The design supports critical thinking by utilising simple machines covered in the school curriculum, while at the same time instilling a passion for outdoor activity. Research was first conducted on the child’s ability to learn and develop physical and mental skills followed by benchmarking existing products that encourage development. After executing the design process, a final design was selected with special emphasis on safety and environmental factors. The product was constructed around an innovative octagonal connector/fastener. The design was then validated via computational simulation as well as prototype construction and user testing. It is hoped that the design outlined in this paper would contribute to building young designers and a culture of innovation and design through play. The intention is for this design to be manufactured and installed in primary schools throughout Trinidad and Tobago and regionally. Keywords: Constructivist approaches, Design, Mechanical Playground Kit, Children

20. Testing Three Cardiovascular Disease Risk Prediction Models for the Trinidad and

Tobago Population Amalia Hosein1, Natasha Ramroop Singh2, and Valerie Stoute3

1,2,3 Biomedical Engineering Unit, The University of Trinidad and Tobago, Trinidad and Tobago, West Indies; E-mails: [email protected]; [email protected]; [email protected]

Abstract. Cardiovascular diseases (CVD) are the diseases involving the heart and blood vessels, especially the veins and arteries leading to and from the heart. CVD is currently the leading cause of mortality worldwide and Trinidad and Tobago is no exception. The decision about whether to initiate specific preventive action and with what degree of intensity is guided by estimation of the risk for such a vascular event. The risk prediction charts that accompanying these guidelines allow treatment to be targeted according to simple predictions of absolute cardiovascular risk. The main CVD risk prediction algorithms are guided by the Framingham heart study in the United States, SCORE study done in Europe and the Q-risk score used in the United Kingdom, specific for their respective populations. Currently, in Trinidad and Tobago, we use a combination of all three models depending on the preference of the attending cardiologist or institution. This study tested the validity of these three risk prediction models in establishing CVD risk for the Trinidad and Tobago population. In addition, we determined the clinical utility of a genetic risk score in predicting CVD risk from several established common genetic variants (single-nucleotide polymorphisms [SNPs]) that are robustly associated with myocardial infarction (MI), coronary heart disease (CHD), or CVD risk factors. These studies have been done mainly among the Anglo-Saxon population in the United States and Europe. For this study we hope to determine if the Trinidad and Tobago population has similar genetic variants as well as the traditional risk factors robustly associated with CVD. The results of our study will assist physicians in utilising CVD risk prediction models that are better suited to our unique population in Trinidad and Tobago. Keywords: Cardiovascular Disease, Risk Prediction Models, Population, Trinidad and Tobago

21. An Android Application for Detection and Self-Monitoring of the Diabetic Foot

Ulcer Keri Gobin1 and Karen Louison2

Biomedical Engineering, The University of Trinidad and Tobago; O’Meara Campus, Trinidad and Tobago, West Indies. E-mails: [email protected]; [email protected]

Abstract. Trinidad and Tobago has an estimated 140,000 people who suffer from diabetes mellitus and its varied complications. The resultant economic cost to this country is projected to range between 177 million and 296 million US dollars per year. The diabetic foot ulcer, the most common complication of diabetic mellitus, not only contributes in large part to this economic cost because of the increased likelihood of lower limb amputation, disability payments, hospital and other medical costs and loss of earnings, but there is also a coincident loss in the quality of life for many of our citizens. A National Risk study done by the Ministry of Health determined that more than 450 non-traumatic lower limb amputations occurred in people with diabetes in 2011. Previous studies have also found that 50% of people with lower limb amputation go into depression and 20% die within two years. Frequent and regular assessment of the diabetic foot can reduce these complications by improving access to early detection and allowing timely treatment of the diabetic foot ulcer. The objective of this research is to develop an accurate, easy-to-use, non-intrusive method for self-assessment of the diabetic foot. A relatively low cost mobile phone attachment is utilised to generate thermal images of the sole of the foot. These images are then analysed using a specifically designed computer

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application for detection of the development of a new foot ulcer or for monitoring of the healing of an already present ulcer. The patient is then alerted to his or her status and a message generated which can be sent to his preferred medical practitioner at the click of a button. Thermal imaging has already been proven to be a useful technique in the clinical management of the diabetic foot. This work provides a novel method of utilising this promising technology in the provision of necessary telemedicine in Trinidad and Tobago. The initial study uses data from a small sample of diabetic patients, already under physician supervision, for the development and testing of this application. The final product is intended to provide a successful method of self-assessment for diabetic patients. Keywords: Android Application, Detection, Self-Monitoring, Diabetic Foot Ulcer

22. Geographical Distribution of Road Traffic Fatalities in Trinidad

Chavin D. Gopaul

Biomedical Engineering Unit, The University of Trinidad and Tobago, Trinidad and Tobago, West Indies E-mail: [email protected]

Abstract. In the past, studies conducted in Trinidad and Tobago were primarily concerned with patterns of seat belt use by drivers, trends in road crashes and their economic burden. Causes of mortality of young men and various road fatality models were developed but without robust epidemiological data, it is difficult to understand or determine trends or establish models. This paper seeks to examine road fatalities in Trinidad in an effort to provide recommendations on how road accidents and the number of casualties can be mitigated through Geographic Information Systems (GIS). GIS describes topography and time of an event in a defined vector space. In order to achieve this, the paper examines a number of maps of Trinidad. Using data collected from different parts of Trinidad, the following maps were developed using Arc GIS Maps 10. The data analysed was collected from 335 locations within Trinidad and contains information on the occurrence of accident fatalities from 2000 to 2011. This information includes the total number of accidents by administrative area, Municipal Corporation, population distribution and socio-economic status of the community. These factors will be used to determine the trend of accidents using Geographic Information Systems (GIS). Therefore GIS can be perceived as an important tool in analysing road fatalities in a given geographical area. This analysis has led to identifying patterns of road fatalities as well as tangible recommendations that can reduce road fatalities. It was evident that there was a significant relationship between the number of accident fatalities and the administrative area, Municipal Corporation, population distribution and socio-economic status of the community. More importantly, in regions with high population such as City of San Fernando, Tunapuna, Port of Spain, San Juan, Laventille, and Diego Martin, the number of road fatalities was elevated. Therefore, recommendations such as increased patrols, speed cameras and road design changes have been made. Keywords: Road Traffic Fatalities, Geographic Information Systems, Trinidad and Tobago

23. Establishing a New System of Biomedical Technology Assessment in Trinidad and

Tobago Natasha Ramroop Singh2

Biomedical Engineering Unit , The University of Trinidad and Tobago,Trinidad and Tobago, West Indies. E-mail: [email protected]

Abstract. Biomedical engineering (BME) has evolved over the years in response to advancements in science and technology and has only recently emerged as its own study, compared to the “traditional” engineering fields. This evolution from being an interdisciplinary specialisation among already-established fields, to being considered a field in itself is highly significant, and recognition of such is paramount to appreciating and understanding the role this novel engineering discipline can play in the optimisation of healthcare delivery systems in our country. Hospital and Health Centres are the foci of the Healthcare system. These highly specialised structures house clinical labs, offices, operation theatres, consultation and examination rooms, patient quarters, imaging and diagnostic laboratories, kitchens, pharmacies, storage rooms and a host of other specialised areas. Biomedical Engineering is the link that merges technology, infrastructure, human resources and communication systems to create a holistic, sustainable healthcare system. The wide range of diagnostic, technical, therapeutic and direct support services for patient care able to be provided by BME staff is critical to the other Heath sector workers and the patients they serve. In this work, a new method for Technology Assessment is proposed, which provides an analysis framework containing the most important assessment elements for arriving at a concise and high quality evaluation of a particular medical technology. This method applies various assessment tools to a range of medical technologies to determine the clinical utility and the business feasibility of these technologies. This method would be applicable to both companies (any size enterprise that

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designs, manufactures and/or markets medical devices or systems for the worldwide market) and hospitals (any care delivery institution or system, regardless of size, location or specialty). Measurement devices, therapeutic devices and clinical information systems are all able to be assessed using the method described. The method is not intended for the analysis of pharmaceuticals. Moving forward, the five (5) Regional Health Authorities that exist in Trinidad and Tobago (T&T) must restructure their organisational configurations to include a larger number of BME Staff at individial Hospitals and Medical Centres. Training of such staff at our tertiary level institutions must be done in close consultation with the Ministry of Health of T&T, to ensure the Health Industry’s demands are being met. Parallel to this, the Ministry of Health of T&T should consider recommendations made for implementation of policies and procedures in line with internationally acclaimed standards. Proposals suggested based on results of current academic research and development exercises should also be contemplated. Keywords: Biomedical Technology Assessment, Healthcare system, Trinidad and Tobago

24. Development of a Supercritical Fluid Extraction Industry in Trinidad Sharad Maharaj1, Marian Watson2, Rosemarie Skeene3, and David R. McGaw4

1,4Department of Chemical Engineering, The University of the West Indies, St Augustine Campus, Trinidad and Tobago, West Indies; E-mails: [email protected]; [email protected]

2,3The University of Trinidad and Tobago, Trinidad and Tobago, West Indies; E-mails: [email protected]; [email protected]

Abstract. World trade in Essential Oils, Oleoresins and other plant extracts has grown significantly over the years such that trade in such oils has been estimated to be over US$5b in 2014, and rising steadily. Such extracts have a wide variety of uses and are typically used commercially in food additives, neutraceuticals and personal care products including fragrances. The traditional extraction technology is that of steam distillation for essential oils and solvent extraction for oleoresins. However the more modern technology of Supercritical Fluid Extraction, which uses Carbon Dioxide as the extraction fluid, has the capability of producing both types of products. A case is presented for the introduction of a flexible commercial Supercritical Fluid Extraction (SFE) operation in Trinidad, whereby waste carbon dioxide from the ammonia industry is used to extract high value products from indigenous plant materials. The process basically consists of a size reduction unit, a drier and a number of SFE units, and it is projected that it would process a limited range of products based on the availability of raw materials. Typical raw materials would be waste products from food processing such as orange peel and pumpkin seeds, as well as crops currently grown locally such as turmeric and hot peppers, together with new short crops which could be introduced such as basil, patchoulli and vetivier. The potential for the production of very high value extracts such as the perfume base from ylang ylang should also be evaluated, but this being a tree crop, would be longer term. The new crops could utilise land formerly used for sugar cane. Background research on the extraction characteristics of most of the above potential raw materials has been carried out on bench scale SFE units, and typical data for pumpkin seeds and ylang ylang is presented, giving extraction curves (% extraction with time), variation of total quantum of extraction with varying processing conditions (operating pressure and temperature), as well as product quality as evidenced by chromatographic analysis. The potential for producing both essential oil and oleoresin separately from turmeric in a single operation, by changing operating conditions during a run, is also presented. A flowsheet for the envisaged process is presented, together with an order of magnitude estimate of the capital cost of the operation. Preliminary market data is presented giving current relevant commodity prices. This is then used to demonstrate that such an operation could be commercially feasible and a Business Plan should be developed to move the concept forward. The potential for introducing this concept in Dominica, one of the Windward Islands where Bay Oil has been produced by steam distillation for many years, is also discussed. Keywords: Supercritical Fluid Extraction, Chromatographic Analysis, Industry, Trinidad and Tobago

25. Plastic Waste to Petrochemical Feedstock

Jeffrey V. Smith1, Sydney Thomas2, Lebert H. Grierson3, and Alan J. Harper4

1,2 Department of Chemical Engineering, The University of the West Indies, St Augustine, Trinidad and Tobago, West Indies E-mail: [email protected]; [email protected]

3 Department of Chemistry, The University of the West Indies, St Augustine, Trinidad and Tobago, West Indies; E-mail: [email protected]

4School of Engineering and Physical Science, Heriot-Watt University, Riccarton, Edinburgh, Scotland; E-mail: [email protected] Abstract. From the 1.5 million plastic beverage bottles consumed in Trinidad and Tobago on an average day, a total of some 11,000 tonnes of polyethylene terephthalate (PET) waste is generated per annum. A percentage of these bottles is ‘recycled’

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(the rest going to landfill or disposed of indiscriminately in the environment) but even this just amounts to chipping up the bottles and shipping to Asia. Thus a valuable hydrocarbon resource is lost to the Islands’ industries or ends up creating an environmental problem. The recent drop in the international value of oil, with the consequent serious implications for Trinidad and Tobago, makes it necessary to minimise outflows of foreign exchange from the country. The recycling of these plastic bottles (currently treated as waste) could result in the dual benefits of reduction in foreign exchange outflows, as well as negating an adverse environmental situation. The discipline of Industrial Symbiosis is focused on the development of techniques to turn apparent waste into industrial feedstocks. One feature of applying this discipline to any isolated community is to fit techniques of valorisation to industries and technologies already employed. Trinidad and Tobago, renowned as a major international player in methanol synthesis, would be an ideal location for recovery of feedstock from waste PET via a process of methanolysis. The product of this process would be able to be introduced in an upstream position in a petrochemical chain (new to Trinidad and Tobago), involving the manufacture of PET resin. This would provide alternative feedstock while reducing foreign exchange outflows and simultaneously tackling an environmental problem. This presentation will highlight the alternative approaches available for the recycling of waste PET, including physical, chemical and energy valorisation options. The methanolysis of waste PET to produce dimethyl terephthalate (DMT) and ethylene glycol (EG) will be examined in greater detail. At all times a Trinidad and Tobago/Caribbean perspective will be maintained. This continues work previously carried out at The University of the West Indies, St Augustine. Keywords: Plastic Waste, Polyethylene Terephthalate (PET), Petrochemical Feedstock, Trinidad and Tobago

26. Industrial Symbiosis and Waste Minimisation in the Caribbean: Waste Tyres to

Petrochemical Feedstock Maria Kesse1, Lorraine Sobers2 and Alan J.Harper3

1School of Engineering and Physical Science, Heriot-Watt University, Riccarton, Edinburgh, Scotland; E-mail: [email protected]

2Department of Chemical Engineering, The University of the West Indies, St Augustine, Trinidad and Tobago, West Indies; Email:[email protected]

3School of Engineering and Physical Science, Heriot-Watt University, Riccarton, Edinburgh, Scotland; E-mail: [email protected] Abstract. As much as 19,000 tonnes per year of waste tyres and associated rubber has been estimated to be generated in Trinidad and Tobago annually. Only a small fraction of this can be utilised in a second life in marine or agricultural infrastructure, and apart from the aesthetic and landfill capacity issues, there is also a serious public health problem with abandoned tyres being potential breeding ground for insects and vermin. A partial solution is shredding of the tyres but that still means material going to landfill. With the recent drop in the international value of oil, it is necessary to export as high a proportion as possible to earn foreign exchange for the economy and the use of this material currently treated as waste as a petroleum substitute in the petrochemical industry. The discipline of Industrial Symbiosis is focussed on the development of techniques to turn apparent waste into industrial feedstocks. One feature of applying this discipline to any isolated community is to fit techniques of valorisation to industries and technologies already employed. Trinidad and Tobago has a well-developed petrochemical industry which would be capable of receiving as feedstock breakdown products of vulcanised rubber and fabric from chemically recovered tyres. Metal reinforcements could also be recycled to the steel industry. One technology which has been demonstrated in Europe is pyrolysis of tyre fragments. The products of this process would be able to be introduced in an upstream position in a petrochemical chain, providing alternative feedstock and enhancing the export of oil. Sulphur from the vulcanisation bonds can be transformed in the established petrochemical facilities to sulphuric acid and carbon char can be added to asphalt. Keywords: Industrial Symbiosis, Waste Minimisation, Waste Tyres, Petrochemical Feedstock

27. How Energy Dynamics Limited is Expanding Opportunities for Organic Waste

Producers in the Dominican Republic to Become Energy Providers, Waste Treatment Operators and Organic Fertiliser Suppliers

Kamel Singh

Energy Dynamics Ltd., #1 Deane Street, St Augustine, Trinidad and Tobago, West Indies, E-mail: [email protected]; [email protected]

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Abstract. Organic waste producers in the Dominican Republic (DR) such as livestock, fruit and vegetable farmers, slaughter houses, meat processors and packing plants, dairy, juice and beverage manufacturers, hotels, restaurants and canteens, were faced with burgeoning disposal cost for its waste (special processing equipment, collection and haulage, gate/tipping fees at landfill sites, penalties for improper disposal, and conformance with stricter environmental laws). Energy Dynamics Limited (EDL) through its outreach programme and active participation in the EE and RE sector was invited by the DR AMCHAM, Moca Chapter to present solutions to its agro-processors and help to develop project ideas for the disposal of organics and help keep its agricultural sector competitive. After careful consideration of the problem, EDL proposed an anaerobic digestion (AD) model, either farm scale or a larger centralised co-digestion facility processing a wider range of substrates as a multifaceted solution to the sector’s disposal problem. The choice of AD also provided a closed nutrient cycle from the production of organic substrates to application of digestate as fertiliser to the fields. In addition, when the biogas, a byproduct of AD is burnt, the carbon dioxide released is absorbed by plants during photosynthesis (carbon neutral). The AD plant operator will be able to earn income through energy production, waste treatment and organic fertiliser sales: 1) Electricity and heat production from biogas produced by AD sold to the national electricity, heating or cooling grid. 2) Liquid manure, dung and organic waste result in persistent unpleasant odor and attract flies. AD reduces odor by as much as 80%; digestate almost odorless and ammonia odor disappear shortly after application as fertiliser to fields. 3). Production of digestate, a valuable soil fertiliser rich in N2, P, K and micro-nutrients, applied directly to fields with usual equipment for liquid manure. Improved fertiliser efficiency due to better homogeneity, nutrient availability, better C/N ratio and significantly reduced odors. Digestate replaces chemical fertilisers synthesised from fossil fuels. This paper will provide an insight to AD technology, process models proposed, security of supply of organic substrates, renewable energy incentives in the DR and some of the technical, economic, financing, project and safety considerations for successful implementation of an AD plant. In addition, it raises awareness of the technology and demonstrates opportunities to farmers and agro-processors of the opportunities to become energy providers, waste processors and organic fertiliser suppliers. Keywords: Organic Waste, Waste Treatment, Anaerobic Digestion, Plant operation, Energy Production

28. Radiation Shielding Parameters of Concrete Made with Electric Arc Furnace Slag

Aggregates Davatee Maharaj1 and Abrahams Mwasha2

1The Vishnu Boys Hindu College, Trinidad, West Indies; E-mail: [email protected]; 2Department of Civil and Environmental Engineering, The University of the West Indies, St Augustine, Trinidad and Tobago, West

Indies; E-mail: [email protected] Abstract. The most common form of shielding utilised in x-ray rooms is lead. However, in recent times, much focus is being placed on the use of heavyweight concrete for shielding radiation. This work examines the effectiveness of concrete made with electric arc furnace slag aggregates for minimising the intensity of x-ray radiation. Electric arc furnace slag is an industrial by-product from the steel making process and its use as aggregates is expected to make concrete production more cost effective and sustainable. The utilisation of this material as aggregates in concrete to shield radiation is a novel approach and could provide decision makers with insights in designing shielding partitions for x-ray rooms. In this study, different thicknesses of concrete specimens of 15cm, 17cm, 19cm and 22cm are exposed to x- ray energies of 40kV, 60kV, 80kV, 100kV, 125kV and 150kV. It was found that at increased thicknesses of the concrete samples, the linear attenuation, mass attenuation coefficient, half value layer and tenth value layer of the concrete improved. This indicates that it is possible to construct slag concrete shielding partitions with thicknesses of 104.5mm, 156mm and 176mm respectively which give the same transmission factor as the lead thickness usually used. At 125kV, a relation has been created showing that there was good correlation between the theoretical and experimental values of the transmission factors at the different thicknesses of the slag concrete which could be used to design the x-ray partition walls. These results indicate a practical perspective of replacing lead with concrete to reduce the intensity of x-ray radiation. Keywords: Shielding Radiation, Parameters, Concrete, Furnace Slag Aggregates

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29. Design of a Special-Effects Wrist-Mounted Flamethrower Kathryn Maharaj1, Chris Maharaj2, and Umesh Persad3

1,2 Department of Mechanical and Manufacturing Engineering, The University of the West Indies, St Augustine, Trinidad and Tobago, West Indies; E-mail: [email protected]

3The University of Trinidad and Tobago, Trinidad and Tobago, West Indies; E-mail: [email protected] Abstract. Fire is one of the elements that is most used in the entertainment industry, and while there have been significant advances in the computational simulation and rendering of fire, the perfect structure of the element has yet to be captured in a realistic form. Additionally, the cost of creating these effects can become very expensive. Given this, filmmakers sometimes opt to have their special effects teams step in and build realistic devices that actually generate fire from controlled explosions and pyrotechnics. In the era where unrealistic visual effects are being harshly reviewed by the audience and critics alike, it is important for a safe alternative to be made available for future productions. To address this need for a compact and controlled flame throwing device, the design process was executed in phases following accepted design process models customised to the task at hand. Activities included need finding and research (benchmarking, customer needs definitions and design specifications), functional modelling, and conceptual design generation and evaluation using systematic methodologies. In addition, safety was a prime focus and a detailed safety plan utilising FMEA Techniques (Failure Mode and Effects Analysis) was developed. A functional prototype was constructed and tested for utility, usability and safety with visual effects and other entertainment specialists. This work presents the final 5-lb device (called Prometheus) that looks to enhance the special effects industry by creating a flamethrower that is capable of being mounted close to the body and triggered with the single press of a button by making use of a piezoelectric spark generator. Like many conventional flamethrowers, the Prometheus consists of three major working systems: 1) the storage area and propellant system, 2) the spraying mechanism to distribute the fuel (in this case butane gas) and 3) the lighting mechanism. Various features of the Prometheus make it a compact and wearable device, with a maximum working flame height of 3 feet, as outlined in the paper. User testing demonstrated that the device functions as intended, and there is potential for the device to be further developed for use in the special effects industry and elsewhere such as Carnival festivals at a cost-effective price. Keywords: Prometheus, Flamethrower, Functional modelling, Conceptual Design

30. The Engineer in the Fourth Industrial Revolution

St. Clair A. King1, Ronald De Four2

1,2 Department of Electrical and Computer Engineering, The University of the West Indies, St Augustine, Trinidad and Tobago, West Indies; E-mails: [email protected]; [email protected]

Abstract. The recent DAVOS 2016 (world Economic Forum) highlighted the fact that we are entering the fourth industrial revolution. The revolutions the world has already witnessed focussed on improvements in automation and connectivity - the first on early automation via machinery and improved intra-national connectivity via the construction of bridges, roads, railways; the second, wherein automation allowed mass production and fostered more efficient, productive connectivity via the division of labour; the third was driven by the rise of the digital age, of more sophisticated automation and increasing connectivity between humanity and the natural world. The Fourth Industrial Revolution is being driven by extreme automation and connectivity especially through wider implementation of intelligent systems - artificial intelligence. The impact of this revolution on the global economy will be; polarisation of the labour force as low-skilled jobs are automated and the same spreading to middle skilled jobs. Flexibility will be the key to success; economies with the most flexible labour markets, education systems, R&D centres, good infrastructure and legal systems are the likely beneficiaries. Hence developed economies will most likely be the winners at this stage, whereas developing economies will face greater challenges as their abundance of low-skilled labour ceases to be an advantage and becomes a “head wind” restraining development; their limited technological infrastructure will not allow them to reap the full benefits of extreme connectivity. Hence, devaluation of currencies to improve productivity will lose its economic significance. The question that should be on the lips of all at this conference is how will the fourth revolution impact the training/jobs/careers of our engineers? Our traditional engineers could become irrelevant particularly in the production of innovative products and services even though they may understand the associated science and technologies, the mathematics that support these - if they do not become highly skilled, learn how to use/build the digital instructions that allow the extreme connectivity among engineering components and sub systems and users; the creation of intellectual property will drive competitiveness. This paper will expand on these ideas and demonstrate the impact the revolution must have on the training and education of our engineers and define the emerging global economic environment in which local engineers will have to innovate in and diversify, as we must, our economy. This paper will also discuss an on-going project that is anticipating this emerging environment by creating novel control/automating systems that will be required in the

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new transportation and manufacturing products. This project concentrates on automation and connectivity using off the shelf components; the genius is in putting them together using the digital languages to obtain optimum efficiency and performance. Hence, the skills that our engineers have to acquire include the ability to implement novel digital connectivity among components and subsystems and creating innovative products/services. It is insufficient simply to understand and operate the technologies if we are to become globally competitive. Keywords: Fourth Industrial Revolution, Engineers, Trinidad and Tobago

31. What Does COP21 Mean for Engineering in the Caribbean?

Lorraine Sobers1 and Selwyn Lashley2 1Department of Chemical Engineering, The University of the West Indies, St Augustine, Trinidad and Tobago, West Indies

E-mail: [email protected] 2The Ministry of Energy and Energy Affairs, Trinidad and Tobago, West Indies

Abstract. The Paris Agreement signed by 195 countries in December 2015, provides scope for a flexible, supportive framework for climate change adaptation and mitigation for developing countries and small island developing states (SIDS). From the outset, Articles 2 through 4 of the Agreement, the overarching purpose and framework of the agreement signal an era of new investment and opportunities for financing projects, technology transfer and capacity building to support climate change adaptation and mitigation. As signatories to the agreement, Caribbean SIDS have agreed to participate in a global response to the threat of climate change by undertaking ambitious efforts to achieve the purpose of the agreement. The path toward ambitious, economy-wide emission reduction cannot be done without innovative engineering solutions. In Article 2, the Agreement sets out: 1) a limit to the increase in global average temperature, 2) intention to increase low greenhouse gas emissions development and, 3) making finance flows consistent. The agreement also reflects 'the principle of common but differentiated responsibilities and respective capabilities, in light of different national circumstances'. Article 3 explicitly states that 'The effort of all parties will...[recognise] the need to support developing country Parties for the effective implementation of this Agreement'. For Caribbean SIDS, this means that there is the possibility of realising opportunities for the development of new technologies and attracting new investments, particularly for technologies such as renewable energy, coastal engineering, carbon capture and storage. Article 4 Section 5 elaborates on the agreed relationship between developed and developing countries: "Support shall be provided to developing country Parties for the implementation of this Article, in accordance with Articles 9, 10 and 11, recognising that enhanced support for developing country Parties will allow for higher ambition in their actions." Citizens of Caribbean SIDS may argue that the response to the threat of climate change should not weigh heavily on developing countries which contribute less than 1% of total global emissions as they pursue sustainable development. The Paris Agreement recognises this as “differentiated responsibilities”, “respective capabilities” and “national circumstances”. This paper will highlight the potential for Caribbean SIDS to transition to low carbon economies with financial and technical support for developing new technologies. The Paris Agreement is a vehicle to allow Caribbean SIDS to keep pace with global changes production and use of fossil fuels. Other SIDS are recognising this opportunity within their respective contexts and have their countries as spaces for research and development of cutting edge technology on a small scale before wide deployment in larger countries. Keywords: Climate Change, Adaptation, Mitigation, Caribbean, Small Island Developing States (SIDS)

32. Developing Software Objects to Mimic Real World Objects in the Design of Water

and Sewer Systems Rheal Thomas1, Donica Mahabir2 and Clint Sutherland3

1WASA, Operations Division, Trinidad and Tobago, West Indies; E-mail: [email protected]; 2Information and Communications Technology Department, The University of Trinidad and Tobago, West Indies

3Project Management and Civil Infrastructure Systems, The University of Trinidad and Tobago, San Fernando Campus, West Indies; Email: [email protected]

Abstract. The aim of this work is to explore and develop software objects for the purpose of mimicking real world objects for the design and operation of water and sewer networks. Most water and sewer networks are primarily dynamic due to the large variations in operational parameters and design constraints. The optimising and matching of pipe type, size, velocity, slope, and depth to obtain an adequate design can impose significant difficulties particularly when significant changes in site

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topography and soil characteristics are present. The prohibitive cost of design software has resulted in the restriction to manual techniques, which can produce a suitable design, but often not an optimised one. Computer simulations can be a useful tool to aid in managing and analysing the complex non-linear relationships and interactions of these processes. In this work software objects are created and defined as classes so that multiple objects of the same type can be developed. Concepts such as inheritance, polymorphism, mutation and abstraction were then applied to the network structure. A recursive function was created, which maps the flow in the individual pipes thereby simplifying the developmental process. This structure allows the designer to reuse, refine, test, maintain and extend the components of water and sewer networks. As a result, there was significant improvement in computation efficiency and versatility of the network. This software structure can aid a designer in making more informed, rational and cost-effective decisions regarding new and future expansion of networks. Using this flexible design concept, the designer can manipulate and optimise a network while ensuring consistency in the use of design codes. Keywords: Software Objects, Real World Objects, Design, Water and Sewer Systems

33. The Advanced Geophysical Monitoring Network of the Eastern Caribbean

Lloyd L. Lynch1 and Chan Ramsingh2

1The Advanced Geophysical Monitoring Network of the Eastern Caribbean, Trinidad and Tobago, West Indies E-mail: [email protected]

Abstract. Since 2006, members of the earth and ocean science communities of the Caribbean and adjacent regions have been engaged in a concerted effort to build an advanced geophysical monitoring infrastructure to bolster defences in the Caribbean against geological hazards. The initiative to upgrade regional earthquake and volcano monitoring systems could be traced back to the turn of the century, but it was hindered primarily by the limited capabilities of affordable communications technologies that were available in the region. The Sumatra earthquake and associated Indian Ocean tsunami reinforced the point demonstrated almost a decade earlier by the Montserrat volcano eruption – that vulnerability to geological hazards in the region posed a significant threat to lives and livelihood and that an improved monitoring system was needed to reduce risks. Within months after this event, stakeholders in the Caribbean and adjacent areas, led by the UNESCO-IOC (Inter-Governmental Oceanic Commission) set about establishing a regional early warning system for tsunamis. With additional impetus provided by the 2010 Haiti earthquake and support from international stakeholders, this initiative has resulted in the creation of an advanced multi-parameter geophysical monitoring system. Today, the monitoring infrastructure comprises over 100 state-of-the-art high dynamic-range, broad-band seismic monitoring installations, over 50 sea-level monitoring gauges and about 120 high-precision continuous operating GPS reference stations. These instruments are geographically distributed among several nations across the region and are deployed in various configurations to log a wide range of geophysical data including ground motion, transient sea level and even perceptible water vapour in the atmosphere. The communication media is made up of satellite, spread spectrum radios, cellular (GPRS) and Internet. Data are acquired at various latencies, archived and distributed to the research communities from designated repositories. Data streamed in real-time and near real-time formats are used for early warning detection of volcanic activity and tsunamis. This submission provides an overview of the technical specification, design and maintenance strategies and some results obtained from the eastern Caribbean subcomponent of this system. Keywords: Geophysical Monitoring, Network, Caribbean

78 JAPETT; Vol. 45, No.1, July 2017

Association of Professional Engineers of Trinidad and Tobago

Executive Council, 2016- 2017

Eng. Fazir Khan President Eng. Imtiaz Easahak President-Elect Eng. Chris Maharaj Vice President - Strategy Eng. Roger Chan Soo Vice President - Operations Eng. Vince Ramlochan Honorary Secretary Eng. Sarah Scoon Assistant Secretary - Strategy Eng. Vishwanath Maraj Assistant Secretary - Operations Eng. Frances Lum Young Honorary Treasurer Eng. Kester Gabriel Assistant Treasurer Eng. Suzette Baptiste Public Relations Officer Eng. Neil Dookie Immediate Past President Eng. Anna Warner Chair, Chemical Division Eng. Ancile Brewster Chair, Civil Division Eng. Richard Akong Chair, Electrical Division Eng. Jainarine Bansee Chair, Mechanical and Industrial Division

Association of Professional Engineers of Trinidad and Tobago

Executive Council, 2017- 2018

Eng. Imtiaz Easahak President Eng. Valerie Kelsick President-Elect Eng. Vince Ramlochan Vice President, Strategy Eng. Jainarine Bansee Vice President, Operations Eng. Vishwanath Maraj Honorary Secretary Eng. Everson Peters Assistant Secretary, Strategy Eng. Haresh Ramrattan Assistant Secretary, Operations Eng. Frances Lum Young Honorary Treasurer Eng. Karlene Jones Assistant Treasurer Eng. Suzette Baptiste Public Relations Officer Eng. Fazir Khan Immediate Past President Eng. Anna Warner Chair, Chemical Division Eng. Ancile Brewster Chair, Civil Division (till August 2017) Eng. Leighton Ellis Chair, Civil Division (after August 2017) Eng. Laura Lewis Chair, Electrical Division Eng. Michael Merritt Chair, Mechanical/Industrial Division

Author guidelines The Journal of The Association of Professional Engineers of Trinidad and Tobago Copyright: Articles submitted to The APETT Journal (ISSN 1000 7924) should be original contributions and should not be under consideration for any other publication at the same time. Authors submitting articles for publication warrant that the work is not an infringement of any existing copyright and will indemnify the publisher against any breach of such warranty. For ease of dissemination and to ensure proper policing of use, papers and contributions become the legal copyright of the publisher unless otherwise agreed. Submissions should be sent to: The Editor: Professor Kit Fai Pun, c/o Faculty of Engineering, The University of the West Indies, St Augustine, Trinidad and Tobago, West Indies. Tel: 1-868-662-2002 ext-82068/82069; Fax: 1-868-662-4414; E-mails: [email protected] and [email protected]. Editorial Aim and Policy: The journal aims to provide a broad international coverage of subjects relating to engineering. It welcomes the submission of papers in various engineering disciplines and related areas. Emphasis is placed on the publication of articles which seek to link theory with application or critically analyse real situations with the objective of identifying good practice cross different engineering and related disciplines. Preference will be given to papers describing original engineering work, or material of specific interest to engineers and those working in related fields, in Trinidad and Tobago and the Caribbean region.

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publication, e.g. Mulder, K. (2006)(ed), Sustainable Development for Engineers: A Handbook and Resource Guide, Greenleaf Publishing, Sheffield, UK.

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