UNIVERSITI TEKNIKAL MALAYSIA MELAKA

FIBER OPTIC SENSOR FOR PALM OIL DETECTION

This report submitted in accordance with requirement of the Universiti Teknikal Malaysia

Melaka (UTeM) for the Bachelor Degree of Electronic Engineering Technology

(Telecommunications) with Honours

by

MUHAMMAD FAIZ HAFIZUDDIN BIN MOHD NAWI

B071210065

930425-03-5155

FACULTY OF ENGINEERING TECHNOLOGY

2015

BORANG PENGESAHAN STATUS LAPORAN PROJEK SARJANA MUDA

TAJUK: Fiber Optic Sensor for Palm Oil Detection

SESI PENGAJIAN: 2015/16 Semester 2

Saya MUHAMMAD FAIZ HAFIZUDDIN BIN MOHD NAWI

mengaku membenarkan Laporan PSM ini disimpan di Perpustakaan Universiti

Teknikal Malaysia Melaka (UTeM) dengan syarat-syarat kegunaan seperti

berikut:

1. Laporan PSM adalah hak milik Universiti Teknikal Malaysia Melaka dan penulis.

2. Perpustakaan Universiti Teknikal Malaysia Melaka dibenarkan membuat salinan untuk tujuan pengajian sahaja dengan izin penulis.

3. Perpustakaan dibenarkan membuat salinan laporan PSM ini sebagai bahan pertukaran antara institusi pengajian tinggi.

4. **Sila tandakan ( )

SULIT

TERHAD

TIDAK TERHAD

(Mengandungi maklumat yang berdarjah keselamatan

atau kepentingan Malaysia sebagaimana yang termaktub

dalam AKTA RAHSIA RASMI 1972)

(Mengandungi maklumat TERHAD yang telah ditentukan

oleh organisasi/badan di mana penyelidikan dijalankan)

(TANDATANGAN PENULIS)

Alamat Tetap:

No 23, Jalan Kuala Krai,

Kampung Pek, 18500 Machang,

Kelantan Darul Naim.

Tarikh:

Disahkan oleh:

(TANDATANGAN PENYELIA)

Cop Rasmi:

Tarikh: _______________________

UNIVERSITI TEKNIKAL MALAYSIA MELAKA

** Jika Laporan PSM ini SULIT atau TERHAD, sila lampirkan surat daripada pihak berkuasa/organisasi

berkenaan dengan menyatakan sekali sebab dan tempoh laporan PSM ini perlu dikelaskan sebagai

SULIT atau TERHAD.

FAKULTI TEKNOLOGI KEJURUTERAAN Tel : +606 234 6623 | Faks : +606 23406526

Rujukan Kami (Our Ref) : Rujukan Tuan (Your Ref) :

28 JAN 2016

Pustakawan Perpustakaan UTeM Universiti Teknikal Malaysia Melaka Hang Tuah Jaya, 76100 Durian Tunggal, Melaka. Tuan/Puan, PENGKELASAN LAPORAN PSM SEBAGAI SULIT/TERHAD LAPORAN PROJEK SARJANA MUDA TEKNOLOGI KEJURUTERAAN ELEKTRONIK (TELEKOMUNIKASI)(BETT): MUHAMMAD FAIZ HAFIZUDDIN BIN MOHD NAWI Sukacita dimaklumkan bahawa Laporan PSM yang tersebut di atas bertajuk “Fiber Optic Sensor for Palm Oil Detection” mohon dikelaskan sebagai *SULIT / TERHAD untuk tempoh LIMA (5) tahun dari tarikh surat ini. 2. Hal ini adalah kerana IANYA MERUPAKAN PROJEK YANG DITAJA OLEH SYARIKAT LUAR DAN HASIL KAJIANNYA ADALAH SULIT. Sekian dimaklumkan. Terima kasih. Yang benar, _________________________ Tandatangan dan Cop Penyelia * Potong yang tidak berkenaan

NOTA: BORANG INI HANYA DIISI JIKA DIKLASIFIKASIKAN SEBAGAI SULIT DAN TERHAD. JIKA LAPORAN DIKELASKAN SEBAGAI TIDAK TERHAD, MAKA BORANG INI TIDAK PERLU DISERTAKAN DALAM LAPORAN PSM.

iv

DECLARATION

I hereby, declared this report entitled “Fiber Optic Sensor for Palm Oil Detection” is the results of my own research except as cited in references.

Signature :………………………………………….

Author’s Name :.........................................................

Date :………………………………………….

v

APPROVAL

This report is submitted to the Faculty of Engineering Technology of UTeM as a

partial fulfillment of the requirements for the degree of Bachelor of Engineering

Technology (Type your department’s name here) (Hons.). The member of the

supervisory is as follow:

………………………………………………

(Mr. Md Ashadi Bin Md Johari)

vi

ABSTRACT

50 years ago, sensor fibre optics had become one of the most successful and

most most powerful application for both optic fiber and also technology for sensor.

Recently, with rapid expansion in micro or nano technology have increased request

that is high in fiber optic sensor. With higher performance and versatility, space

utilisation that is small also is one of the current trends for optic fiber sensor. This

project to analyze power measurement value in palm oil concentration that is different

and using this fiber optic detector is to know which detector over detector sensitivity.

This analysis may be useful for technology in oil and industrial gas.

vii

ABSTRAK

Pada 50 tahun lepas, serat optik penderia telah menjadi salah satu permohonan

paling berjaya dan paling berkuasa untuk kedua-dua fiber optik dan juga teknologi

untuk penderia. Baru-baru ini, dengan perkembangan pesat di mikro atau teknologi

nano telah meningkat permintaan yang tinggi di penderia gentian optik. Dengan

prestasi lebih tinggi dan keserbabolehan, penggunaan ruang yang kecil juga ialah

salah satu trend-trend semasa untuk penderia fiber optik. Projek ini untuk

menganalisis nilai pengukuran kuasa di dalam kepekatan minyak sawit yang berbeza

dan menggunakan alat pengesan gentian optik ini adalah untuk mengetahui alat

pengesan mana yang lebih sensitiviti alat pengesan. Analisis ini mungkin berguna

bagi teknologi dalam minyak dan gas perindustrian.

viii

DEDICATIONS

This humble effort specially dedicated to my beloved parents, family, lecturers and

friends, whose love can never be forgotten for their support, guidance and

encouragement upon completing this project and report.

Special dedicated to my family

MOHD NAWI BIN UMAR

JUHASWITA BINTI JUNOH

ix

ACKNOWLEDGMENTS

In the name of Allah S.W.T, The most Merciful and The most Passionate, I am

thankful to Allah for enabling me to complete this report.

First and foremost, I would like to thanks to Mr. Md Ashadi Bin Md Johari as my

supervisor, lecturer of Faculty Technology Engineering for giving me a full

cooperation and supervision during the making of this final year report. Not to be

forgotten, I would like to thanks my family and my friends for contributing their ideas

and also encourage me by giving moral support in completing this report.

Lastly, I wish to say deepest gratitude to party directly involved and indirect

to complete my project. All good offices you very I valued.

x

TABLE OF CONTENTS

DECLARATION......................................................................................................iv

APPROVAL.............................................................................................................v

ABSTRACT..............................................................................................................vi

ABSTRAK................................................................................................................vii

DEDICATION...........................................................................................................viii

ACKNOWLEDGEMENT..........................................................................................ix

TABLE OF CONTENTS...........................................................................................x

LIST OF FIGURE.....................................................................................................xiii

LIST OF TABLE.................................................................................................................xvi

CHAPTER 1 INTRODUCTION...........................................................................1

1.1 Project Background...................................................................................................1

1.2 Objective...................................................................................................................2

1.3 Problem Statement....................................................................................................3

1.4 Scope.........................................................................................................................3

1.5 Limitation..................................................................................................................3

CHAPTER 2 THEORETICAL BACKGROUND..............................................4

2.1 Fiber Optical & Fiber Optical Sensor.......................................................................4

2.1.1 Optical Fiber Basics......................................................................................4

2.1.2 Fiber Optic Sensor Principles.......................................................................6

xi

2.2 Biodiesel....................................................................................................................7

2.2.1 Overview.......................................................................................................7

2.2.2 Transesterification Process............................................................................8

2.2.3 Biodiesel Demand.........................................................................................11

2.3 Palm Oil.....................................................................................................................11

2.3.1 Overview.......................................................................................................11

2.3.2 Palm Biodiesel..............................................................................................13

2.4 Light Source..............................................................................................................15

2.4.1 Light Emitting Diodes (LED).......................................................................15

2.4.4.1 Overview...........................................................................................15

2.4.1.2 Input – Output Response...................................................................15

2.4.1.3 Advantages Using LED....................................................................16

2.4.2 Lasers............................................................................................................16

2.4.2.1 Overview...........................................................................................16

2.4.2.2 Semiconductors Lasers.....................................................................17

2.5 Splicing Technology.................................................................................................19

2.5.1 Core Alignment Fusion Splicer....................................................................19

2.5.2 Mass Fusion Splicer for Ribbon Fiber..........................................................21

2.5.3 Specialty Fiber Fusion Splicer......................................................................24

CHAPTER 3 SYSTEM DESIGN AND DEVELOPMENT................................27

3.1 Background...............................................................................................................27

3.2 Overview of Proposal...............................................................................................27

3.3 Research of Title.......................................................................................................28

3.4 Literature Review.....................................................................................................29

3.5 Research The Best Hardware and Equipment Needed.............................................29

3.5.1 OSA (Optical Spectrum Analyzer)...............................................................29

3.5.2 ASE (Amplified Spontaneous Emission).....................................................30

3.5.3 Single Pigtails Optical Fiber and Fiber Optic Cable....................................31

3.5.4 Palm Oils......................................................................................................32

3.5.5 Splicer...........................................................................................................33

3.5.6 Concentration Solvent is Hexane.................................................................34

xii

3.6 Overview of Fiber Optical Sensor.............................................................................35

3.7 Testing & Experiment in Laboratory........................................................................36

CHAPTER 4 RESULT & DISCUSSION.............................................................45

4.1 Introduction...............................................................................................................45

4.2 Block Diagram of Project..........................................................................................45

4.3 Experiment Result.....................................................................................................46

4.3.1 The Power Measurement Fiber Optics Sensor for Palm Oil………………..46

4.3.2 The Sensitivity (W/%) and Linearity (%) in Fiber Optics

Sensor for Palm Oil Detection………………………………………………48

CHAPTER 5 CONCLUSION & FUTURE WORK...........................................52

5.1 Introduction..............................................................................................................52

5.2 Conclusion for Chapter 1........................................................................................52

5.3 Conclusion for Chapter 2........................................................................................52

5.4 Conclusion for Chapter 3........................................................................................53

5.5 Conclusion for Chapter 4........................................................................................53

5.3 Suggestion for Future Work....................................................................................54

APPENDIX.........................................................................................................................55

REFERENCES...................................................................................................................75

xiii

LIST OF FIGURE

CHAPTER 2

Figure 2.1: Basic structure of an optical fiber………………………………………………..4

Figure 2.2: Total internal reflection in an optical fiber………………………………………5

Figure 2.3: Different types of optical fibers………………………………………………….5

Figure 2.4: Basic components of an optical fiber sensor system…………………………….6

Figure 2.5: Extrinsic and intrinsic types of fiber optic sensors……………………………...6

Figure 2.6: Procedure of manufacturing biodiesel through

transesterification with vegetable oil……………………………………………9

Figure 2.7: Transesterification reaction of methanol and triglyceride

in manufacturing of biodiesel…………………………………………………..10

Figure 2.8: Flowchart of commercialized palm biodiesel production……………………….13

Figure 2.9: An LED is a p-n semiconductor device that emits light

when a voltage is applied across its two terminals……………..........................15

Figure 2.10: An LED behaves like a diode………………………………………………….16

Figure 2.11: Core Position Measurement……………………………………………………19

Figure 2.12: Alignment with Movable V-groove and Fusion Splice………………………..20

Figure 2.13: Core Alignment Fusion Splicer FSM-60S……………………………………..21

Figure 2.14: Splicing Method with Fixed V-groove………………………………………...22

Figure 2.15: Self-alignment effect by Surface Melting Tension…………………………….22

Figure 2.16: Heating Ribbon Fiber with Electric Discharge………………………………...23

Figure 2.17: FTTH Application Fusion Splicer……………………………………………..23

Figure 2.18: Specialty Fiber Fusion Splicer…………………………………………………25

Figure 2.19: Adjustable Clamping Mechanism for Optical Fibers………………………….25

Figure 2.20: Discharge Electrodes Vibrating Mechanism…………………………………..26

Figure 2.21: Optical Fiber End-View Image………………………………………………..26

xiv

CHAPTER 3

Figure 3.1: Flow Chart of Proposal........................................................................................28

Figure 3.2: Block Diagram of Fiber Optic Sensor…………………………………………...29

Figure 3.3: Optical Spectrum Analyzer (OSA)......................................................................30

Figure 3.4: Amplified Spontaneous Emission (ASE) ............................................................31

Figure 3.5: Single Mode Pigtails……………………………………………………………..32

Figure 3.6: Fiber Optical........................................................................................................32

Figure 3.7: Palm Oils………………………..........................................................................33

Figure 3.8: Splicer Optical Fiber……………………………………………………………..33

Figure 3.9: Concentration solvent is hexane..........................................................................34

Figure 3.10: Flow Chart of Project.........................................................................................36

Figure 3.11: The equipments needed to construct the fiber sensor

for detections of palm oil.................................................................................37

Figure 3.12: The pigtails fiber optical cable was cut by cutter

to remove of cladding for the core……………………………………………..37

Figure 3.13: The single mode optical cable was cut by cutter

to remove of cladding for the core……………………………………………..38

Figure 3.14: The core for both fibers optical cables was cut

by fiber cleaver to avoid the core of optical cables inverse when

grafted use splicer……………………………………………………………...38

Figure 3.15: The both of fiber optic cables were clean up by using the alcohol

to avoid the dust on the core…………………………………………………...39

Figure 3.16: The two core alignment with Movable V-groove and Fusion Splice………….39

Figure 3.17: Splicing Method the two ore fiber optic cables with Fixed V-groove…………40

Figure 3.18: Self-alignment the core effect by Surface Melting Tension……………………40

Figure 3.19: Core Alignment Fusion Splicer………………………………………………...41

Figure 3.20: Heating Ribbon Fiber the two of core fiber cables

with Electric Discharge………………………………………………………...41

Figure 3.21: The two cores apply on the fusion splicer with the loss measurement………...42

Figure 3.22: The core single mode fiber optic cable combine together

with pigtails cable after process fusion splicer………………………………...42

Figure 3.23: The connection fiber optics sensors for palm oils detections…………………..43

Figure 3.24: A drop concentration palm oil with solvent of hexane…………………………43

xv

Figure 3.25: The value measurement of fiber optic sensors for palm oils

detection in power measurement (dB………………………………………….44

CHAPTER 4

Figure 4.1: Block Diagram of the Fiber Optic Sensor for Palm Oil Detection……………..45

Figure 4.2: Power vs. PPM………………………………………………………………….47

Figure 4.3: The graph shows the 1st slope 850nm in sensitivity and linearity………………49

Figure 4.4: The graph shows the 2nd slope 850nm in sensitivity and linearity……………...49

Figure 4.5: The graph shows the 1st slope 1300nm in sensitivity and linearity……………..50

Figure 4.6: The graph shows the 2nd slope 1300nm in sensitivity and linearity…………….50

Figure 4.7: The graph shows the 1st slope 1550nm in sensitivity and linearity……………..51

Figure 4.8: The graph shows the 2nd slope 1550nm in sensitivity and linearity…………….51

xvi

LIST OF TABLE

CHAPTER 2

Table 1: Sources of fuels of plant origin and their yields in alcohol and oil………………..12

Table 2: Composition of fatty acids in palm oil……………………………………………..12

Table 3: Physical-chemical properties of palm biodiesel and petroleum diesel…………….14

CHAPTER 4

Table 4: Power fiber optic sensor value for palm oil detection use palm oil

that is different the concentration..........................................................................46

Table 5: The table shows the sensitivity (W/%) and linearity (%) in

different the light sources......................................................................................48

1

CHAPTER 1

INTRODUCTION

1.1 PROJECT BACKGROUND

In the past 50 years, fiber-optical sensing has been one of the most successful

and powerful applications of both fiber optics and sensing technology [Spillman, 2001].

Fiber optic sensing is facilitated by its salient features, which make it prominent among

other sensing methods. These fiber optic sensors successfully meet the requirements

like high sensitivity and quick response in sensing different chemical and physical

variables. Using optical fiber sensing devices one can measure or monitor different

physical and chemical parameters in terms of one of the principal parameters that

describes the light beams. These principal parameters include light intensity, phase,

polarization and wavelength. The characteristic features and promising capabilities of

fiber optic sensors make them attractive and place them in the forefront of the

Photonics technology. In the fiber optic sensing system, the sensed signal is immune to

electromagnetic interference (EMI) and radio frequency interference (RFI). Since

optical fibers offer low loss to the signal propagating through it we can use this method

for remote sensing applications.

After the energy crisis in the mid 1970s, every country has tried to find a new

energy that can replace petroleum by using their district energy; specifically, vegetable

oil, the most promising alternative fuels. Vegetable oils cannot be used directly in

diesel engines because of the problem associated with it of the using pure vegetable oils

as fuels in diesel engines. There are more than 350 oil bearing crops identified, among

which only sunflower, soybean, cottonseed, rapeseed and peanut oils are considered as

potential alternative fuels for diesel engines [C. Charoenphonphanich, 2004]. The most

detrimental properties of these oils are their high viscosity, low volatility, poor

atomization and auto-oxidation [C. Y. May, 2005].

Recently considerable attention in developing countries such as Malaysia,

Indonesia and Thailand has been drawn to the production of bio-fuels from domestic,

renewable resources. Bio-fuels are currently being considered from multidimensional

perspectives, i.e. depleting fossil fuels, resources, environmental health, energy,

2

security and agricultural economy. The two most common types of bio-fuels are

ethanol and bio-diesel [A. A. Aziz, 2006]. Chiyuki and Jun-ichi (1998) concluded that

de-acidified rapeseed oil could be used in a single cylinder Yanmar IDI diesel engine

but degummed and crude rapeseed oil were unsuitable for use as fuel due to the high

level of incombustible materials in the oil. Suporn (1987) found that using 100%

refined palm oil in a Kubota diesel engine model KND 5B resulted in the best power

output and best emission while using 70% refined palm oil blended with 25% diesel

resulted in the best specific fuel consumption [T. Apichato, 2003]. For vehicles

powered with diesel engines, an alternative substitute of diesel fuel has been developed

namely, biodiesel. It is produced from the chemical bonding of an alcohol with oils,

fats, greases or chemically known alkyl esters [R. Zanzi, 2006]. These esters have

similar properties as the mineral diesel fuel and even better in terms of its cetane

number. In addition, biodiesel is better than diesel fuel in terms of sulfur content, flash

point and aromatic content [C. Y. May, 2005]. As a liquid fuel, biodiesel is simple to

use and can be used in compression ignition (diesel) engines without modifications. It

also can be blended at any level with petroleum diesel to create a biodiesel blend [A.

Aziz, 2005]. Regarding these qualities of vegetable oils, Malaysia has committed to

investigate the use of biodiesel with blends of palm oil as an alternative fuel for diesel

engines. This paper presents palm biodiesel as an alternative green renewable bio-fuel

for diesel engines.

This project is about to develop the palm oil concentration detection using the

fiber sensor. The main part is the functional of optical fiber in telecommunication

system. The optical fiber can use to detect the concentration of palm oil using the high-

index of oil.

1.2 OBJECTIVE

The main objective of this project:

a. To study fiber optical sensor for palm oil concentration detection.

b. To development fiber optical sensor for palm oil concentration

detection.

c. To analyze the performance of fiber optic sensor for concentration

detection activity.

3

1.3 PROBLEM STATEMENT

Nowadays, the use biomass as an energy source should be part of the climate

change solution as long as it is developed in a truly sustainable way. The problem occur

in our world is the production of biodiesel or bio-fuels are decrease. The biochemistry

makes research and analysis to find new liquor fuels to replace biodiesel using biomass.

Palm oil is now starting to be used as an ingredient in bio-diesel and as a fuel to be

burnt in power stations to produce electricity. This project is implementation using the

application of fiber optical sensor to detect the concentration of palm oil. Reason why

we must detect different concentration? This is because very different power value in

every concentration for performance of palm oil biodiesel as bio-fuel energy.

1.4 SCOPE

The scope of this project is to study and develop fiber optical sensor for palm oil

concentration detection. This project to ensure the project is heading in the right

direction to achieve its objective. The scopes of this project are to study and develop

the Fiber Optical Sensor, Fiber Optical Sensor for Liquor and also Concentration of

Palm Oil.

1.5 LIMITATION

The limitations of the study are those characteristics of design or methodology

that impacted or influenced the interpretation of the findings from a research. They are

the constraints on generalize ability, applications to practice, and/or utility of findings

that are the result of the ways in which there initially chose to design the study and/or

the method used to establish internal and external validity. Some of limitations are:

a. Fiber optical sensor is going too used. b. Sensor can detect the palm oils.

4

CHAPTER 2

THEORETICAL BAKGROUND

2.1 FIBER OPTICAL & FIBER OPTICAL SENSOR

2.1.1 Optical Fiber Basics

An optical fiber is composed of three parts; the core, the cladding, and the

coating or buffer. The basic structure is shown in Figure 2.1. The core is a cylindrical

rod of dielectric material and is generally made of glass. Light propagates mainly along

the core of the fiber [Jones, 1998].

Figure 2.1: Basic structure of an optical fiber.

The cladding layer is made of a dielectric material with an index of refraction.

The index of refraction of the cladding material is less than that of the core material.

The cladding is generally made of glass or plastic. The cladding executes such

functions as decreasing loss of light from core into the surrounding air, decreasing

scattering loss at the surface of the core, protecting the fiber from absorbing the surface

contaminants and adding mechanical strength [Jones, 1998].

The coating or buffer is a layer of material used to protect an optical fiber from

physical damage. The material used for a buffer is a type of plastic. The buffer is elastic

in nature and prevents abrasions [Jones, 1998]. The light-guiding principle along the

fiber is based on the “total internal reflection”. The angle at which total internal

reflection occurs is called the critical angle of incidence. At any angle of incidence,

greater than the critical angle, light is totally reflected back into the glass medium (see

Figure 2.2). The critical angle of incidence is determined by using Snell's Law. Optical

fiber is an example of electromagnetic surface waveguide [Jones, 1998].

5

Figure 2.2: Total internal reflection in an optical fiber.

Optical fibers are divided into two groups called single mode and multimode. In

classifying the index of refraction profile, we differentiate between step index and

gradient index. Step index fibers have a constant index profile over the whole cross

section. Gradient index fibers have a nonlinear, rotationally symmetric index profile,

which falls off from the center of the fiber outwards [Jenny, 2005]. Figure 2.3 shows

the different types of fibers.

Figure 2.3: Different types of optical fibers.

6

2.1.2 Fiber Optic Sensor Principles

The general structure of an optical fiber sensor system is shown in Figure 2.4. It

consists of an optical source (Laser, LED, Laser diode etc), optical fiber, sensing or

modulator element (which transducers the measured to an optical signal), an optical

detector and processing electronics (oscilloscope, optical spectrum analyzer etc.).

Figure 2.4: Basic components of an optical fiber sensor system.

Fiber optic sensors can be classified under three categories: The sensing

location, the operating principle, and the application. Based on the sensing location, a

fiber optic sensor can be classified as extrinsic or intrinsic. In an extrinsic fiber optic

sensor (see Figure 2.5), the fiber is simply used to carry light to and from an external

optical device where the sensing takes place. In these cases, the fiber just acts as a

means of getting the light to the sensing location.

Figure 2.5: Extrinsic and intrinsic types of fiber optic sensors.

7

On the other hand, in an intrinsic fiber optic sensor one or more of the physical

properties of the fiber undergo a change (see Figure 2.5). Perturbations act on the fiber

and the fiber in turn changes some characteristic of the light inside the fiber [Tracey,

1991].

Based on the operating principle or modulation and demodulation process, a fiber optic

sensor can be classified as intensity, a phase, a frequency, or a polarization sensor. All

these parameters may be subject to change due to external perturbations. Thus, by

detecting these parameters and their changes, the external perturbations can be sensed

[Yu, 2002]. Based on the application, a fiber optic sensor can be classified as follows:

Physical sensors: Used to measure physical properties like temperature,

stress, etc.

Chemical sensors: Used for pH measurement, gas analysis, spectroscopic

studies, etc.

Bio-medical sensors: Used in bio-medical applications like measurement of

blood flow, glucose content etc.

2.2 BIODIESEL

2.2.1 Overview

Biodiesel has a major advantage over petroleum diesel, since, it is derived from

renewable sources it is a clean burning fuel that does not contribute to the increase of

carbon dioxide, being environmentally friendly [S. L. Cheah, 2004]. Biodiesel is an

oxygenate, sulphur-free and biodegradable fuel, and its content of oxygen helps

improve its combustion efficiency Therefore, fewer green house gases such as carbon

dioxide are released into the atmosphere. Biodiesel has positive performance attributes

such as increased cetane, high fuel lubricity, and high oxygen content [A. Aziz, 2005].

Since, biodiesel is more lubricating than diesel fuel, it increases engine life and it can

be used to replace sulphur, a lubricating agent, that when burned, produces sulphur

oxide; the primary component in acid rain.

8

2.2.2 Transesterification Process

Biodiesel is a very versatile transport fuel and can be produced from local raw

material or collection of used vegetable or frying oil in rural regions of developing

countries. There are three basic routes to biodiesel production from oils and fats [R.

Ranzi, 2006]:

Base catalyzed transesterification of the oil

Direct acid catalyzed transesterification of the oil

Conversion of oil to its fatty acids and then to biodiesel

Transesterification reaction is a stage of converting oil or fat into methyl or

ethyl esters of fatty acid, which constitutes to biodiesel. Biodiesel (methyl ester) is

obtained through the reaction of triglycerides of vegetable oils with an active

intermediary, formed by the reaction of an alcohol with a catalyst. The general reaction

for obtaining biodiesel through transesterification is [U. H. Bezerra, 2007]:

Oil or Fat + Methanol ⎯⎯→ Methyl Esters +Glycerol

Or

Oil or Fat + Methanol ⎯⎯→ Ethyl Esters +Glycerol

Transesterification reactions may employ various types of alcohols, preferably,

those with low molecular weight, with the most studied ones being the methylated and

ethylated alcohols. Studies have shown that transesterification with methanol is more

viable technically than with ethanol. Ethanol may be used as long as it is anhydrous

(with a water content of less than 2%), since the water acts as an inhibitor reaction.

Another advantage in using methanol is the separation of glycerin (obtained as a by-

product of the reaction) from the reactive medium, since, in the case of synthesis of the

methylated ester, this separation may be easily obtained through simple decantation [U.

H. Bezerra, 2007]. Figure 2.6 illustrates the simplest procedure of manufacturing

biodiesel through transesterification with vegetable oil.