existing and potential technologies for carbon emissions reductions in the indian cement industry

7/30/2019 Existing and Potential Technologies for Carbon Emissions Reductions in the Indian Cement Industry

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Existing and Potential Technologies

or Carbon Emissions Reductions

in the Indian Cement Industry

A set o technical papers produced or the project

Low Carbon Technology Roadmap or the

Indian Cement Industry


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Introduction ............................................................................................................................................. 5

Partner summaries ................................................................................................................................ 6

Overview o the Indian cement industry ............................................................................................ 9

Best Available Technologies (BAT) or a modern cement plant ...................................................10

Technical papers .....................................................................................................................................13

1. Electrical and thermal energy eciency improvements in kilns and preheaters ................... ............... 13

2. Latest generation high eciency clinker coolers........................ .................... ................... .................... ............ 16

3. Energy eciency in grinding systems ................... .................... ................... .................... .................... .................. 18

4. Retrot uni-ow burner with advanced multi-channel burner ................. .................... .................... ........... 21

5. Energy eciency improvement in process ans .................... .................... ................... .................... .................. 23

6. Energy eciency improvement in auxiliary equipment in the cement manuacturing process ..... 26

7. Energy eciency improvement in Captive Power Plants (CPP) .................. .................... ................... ........... 288. Increased Renewable Energy (RE) use or cement manuacture ................... .................... .................... ....... 31

9. Energy eciency improvement in electrical systems .................... .................... ................... .................... ....... 34

10. Utilization o advanced automation systems in cement manuacture .............................. .................... ... 36

11. Increasing Thermal Substitution Rate (TSR) in Indian cement plants to 25.3% .................. .................... 38

12. Opportunities or exploring development o energy plantation by the cement industry ................. 45

13. Reducing clinker actor in y ash based Portland Pozzolona Cement (PPC)................... ................... ...... 48

14. Reducing clinker actor in slag based Portland Slag Cement (PSC) .................. .................... .................... .. 51

15. Reducing clinker actor by using other blending materials .................................... ................... ................... 54

16. Reducing clinker actor by using low grade limestone .................... ................... .................... .................... ..... 56

17. Belite cement rom low grade limestone .................... ................... .................... .................... ................... ............ 58

18. Alternative de-carbonated raw materials or clinker production.................................................................60

19. Improving the burnability o raw mix by use o mineralizer .................................... ................... .................. 62

20. Fluidized Bed Advanced Cement Kiln System (FAKS) .................................... ................... .................... ........... 65

21. Fuel cell technology .................... .................... ................... .................... .................... .................... .................... .......... 67

22. Futuristic comminution technologies ................... .................... .................... ................... .................... ................. 69

23. Carbon capture through algal growth and use o biouels * .................... .................... .................... ............. 72

24. Waste heat recovery .................. .................... .................... ................... .................... .................... .................... ............. 77

25. Geopolymer cement .................... .................... ................... .................... .................... .................... .................... ......... 80

26. Use o nanotechnology in cement production .................... ................... .................... .................... ................... 82

27. Developing national standards on composite cements ................. .................... ................... .................... ...... 85

Contents

Contd...


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Annexures ............................................................................................................................................. 87

Annexure I Glossary o terms ................... .................... ................... .................... .................... .................... .................... ..... 87

Annexure II Denition o Reerence, Best Available Technology (BAT) and Target plants .................. ............ 88

*To see urther papers on the potential o carbon emissions reductions through carbon capturetechnologies in the cement industry, see Development o State o the Art Techniques in CementManuacturing: Trying to Look Ahead, developed by the European Cement Research Academy (ECRA) in2009.

Authors: Conederation o Indian Industry (CII) lead-authored paper 1 to 12 and paper on Best AvailableTechnologies, and National Council or Cement and Building Material (NCB) lead-authored paper 13 to 27.


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This set o technical papers was commissioned by the Cement Sustainability Initiative (CSI) members inIndia. CSI is a member-led program o the World Business Council or Sustainable Development (WBCSD). Thereport represents the independent work o the CII Godrej Green Business Centre (CII Godrej GBC), a centre oexcellence o Conederation o Indian Industry (CII) and the National Council or Cement and Building Materials(NCB). The author o each paper is shown ater its title. It aims to identiy, describe and evaluate technologies,which may contribute to increased energy eciencies and reduced greenhouse gas emissions rom cementproduction in India today and in the longer-term. The results have been reviewed by CII, NCB, CSI membercompanies and stakeholders like the International Energy Agency (IEA).

The roadmap development has been technically supported and part-unded by the International Finance

Corporation (IFC).These papers are based on a set o technical papers titled Development o State o the Art Techniques in CementManuacturing: Trying to Look Ahead, developed by the European Cement Research Academy (ECRA) in 2009.Where no urther technological developments have been made since the ECRA papers, the 2009 inormation isnot repeated here.

All papers ollow the same ormat, outlining the current status o the technology, the impact on energyconsumption, anticipated benets rom implementation, the CO reduction potential, main parametersinuencing implementation, cost estimation, and the conditions, barriers and constraints o implementation.For the more uturistic technologies, where quantication is dicult, a qualitative summary is provided instead,indicating those technologies elt to be promising or uture implementation and emissions reductions potential.In these papers, only the anticipated impact on energy consumption and barriers to urther development can

be shown. In every paper, a range o potential thermal and electrical savings is provided this range has beenreached through consultation with technical experts. Where INR costs are indicated, approximate USD equivalentcosts have also been given, using exchange rate USD 1 = INR 50.

Introduction


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Low Carbon Technology Roadmap or the Indian Cement Industry partner summaries

Cement Sustainability Initiative (CSI)

The Cement Sustainability Initiative (CSI) is a global efort by 25 major cement producers with operations in

more than 100 countries who believe there is a strong business case or the pursuit o sustainable development.Collectively these companies account or about one-third o the worlds cement production and range in sizerom very large multinationals to smaller local producers. The purpose o the initiative is to:

( Explore what sustainable development means or the cement industry

( Identiy actions and acilitate steps cement companies can take, individually and as a group, to accelerateprogress toward sustainable development

( Provide a ramework or other cement companies to become involved

( Create the content and context or urther stakeholder engagement

To date the CSI remains one o the largest global sustainability programs ever undertaken by a single industry

sector. To nd out more, visit www.wbcsdcement.orgIn India, nine member companies collaborated on the development o these papers. They are: ACC Ltd (projectCo-Chair), Ambuja Cements Ltd, HeidelbergCement India Ltd, Laarge India Private Ltd, My Home Industries Ltd /CRH, Shree Cement (project Co-Chair), Shree Digvijay Cement Co Ltd Cimpor Group, UltraTech Cement (projectCo-Chair) and Zuari Cement. Since the roadmap project began, Dalmia Bharat Cement and Jaypee Cement havehas also joined CSI.

International Energy Agency (IEA)

The International Energy Agency (IEA) works to ensure reliable, afordable and clean energy or its 28 membercountries and beyond. Founded in response to the 1973/4 oil crisis, the IEAs initial role was to help countries co-ordinate a collective response to major disruptions in oil supply through the release o emergency oil stocks to

the markets. While this continues to be a key aspect o its work, the IEA has evolved and expanded to help enablethe transition to a sustainable low-carbon energy uture. It is at the heart o global dialogue on energy, providingreliable and unbiased research, statistics, analysis and recommendations. www.iea.org

Conederation o Indian Industry (CII)

The Conederation o Indian Industry (CII) works to create and sustain an environment conducive to the growth oindustry in India, partnering industry and government alike through advisory and consultative processes.

CII is a non-government, not-or-prot, industry led and industry managed organization, playing a proactiverole in India's development process. Founded over 116 years ago, it is India's premier business association, witha direct membership o over 8,100 organizations rom the private as well as public sectors, including Small andMedium Enterprises (SMEs) and multinationals, and an indirect membership o over 90,000 companies romaround 400 national and regional sectoral associations. www.cii.in

CII - Sohrabji Godrej Green Business Centre (CII - Godrej GBC), a division o CII is India's premier developmentalinstitution, ofering advisory services to the industry on environmental aspects and works in the areas o greenbuildings, energy eciency, water management, environment management, renewable energy, green businessincubation and climate change activities. www.greenbusinesscentre.com


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National Council or Cement and Building Materials (NCB)

National Council or Cement and Building Materials (NCB) is an apex R&D organization unctioning under theadministrative control o Department o Industrial Policy and Promotion (DIPP), Ministry o Commerce andIndustry, Government o India (GoI). NCB, in the service o the nation, is devoted to technology development

and transer, testing and calibration, human resource development and consultancy services or the beneto Cement and Construction Industry or the last about 50 years. Its multi-disciplinary activities are perormedin an integrated and coordinated manner through its two larger units located at Ballabgarh (near Delhi) andHyderabad (Both ISO: 9001-2008 Certied) and the third unit at Ahmedabad, guided by the six corporate centers.www.ncbindia.com

IFC

IFC, a member o the World Bank Group is the largest global development institution ocused exclusively onthe private sector. We help developing countries achieve sustainable growth by nancing investment, providingadvisory services to businesses and governments, and mobilizing capital in the international nancial markets.In scal 2011, amid economic uncertainty across the globe, we helped our clients create jobs, strengthen

environmental perormance, and contribute to their local communities - all while driving our investments to anall-time high o nearly $19 billion.

For more inormation, visit www.ic.org

IFC in South Asia

To grow opportunities or the underserved, IFC in South Asia has concentrated on low-income, rural, and ragileregions while building inrastructure and assisting public-private-partnerships; acilitating renewable energygeneration; promoting cleaner production, energy and water eciency; supporting agriculture; creating growthopportunities or small businesses; reorming investment climate; encouraging low-income housing; and makingafordable healthcare accessible.

Through these strategic interventions in the region, IFC aims to promote economic inclusion at the base o the

pyramid, particularly in the low income states o India; help address climate change impacts; and encourageglobal and regional integration including promoting investments rom South Asia into Arica. In South Asia,IFC works in low-income and rontier regions where our work results in quick outcomes and strong impacts.To promote inclusive growth at the base o the pyramid, we built on previous years experiences to engage inworking with the private sector in the region to develop measures that will increase incomes or the poor andsmall businesses.

IFC tries to support projects that are dicult in nature, rst o its kind and reorm oriented. We are increasinglybeing engaged by governments when they see we bring unique knowledge, experience and access to a widenetwork o investors, and sector expertise.

IFC's Sustainable Business Advisory promotes sustainable business practices specically among rms ininrastructure, extractive industries, manuacturing, agribusiness, and services sectors. We ofer these programs

to companies to promote sustainable management and investment practices to create value and growth whileaddressing climate change through encouraging mitigation and building resilience. IFC's Resource Eciencyteams work with rms to save costs, prevent waste, and reduce green house gas emissions through more ecientuse o energy, water, and materials. At the sector level, we promote broader adoption o good practices throughcase studies and benchmarking energy, water, and material use.


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Disclaimer

These papers are the result o a collaborative efort between members o the WBCSD Cement SustainabilityInitiative (CSI) and a wide range o external stakeholders with technical expertise provided by the Conederationo Indian Industry (CII) and the National Council or Cement and Building Materials (NCB). External stakeholders

were consulted on the technology papers and comments received are reected here.

The individual member companies that make up the CSI, and their subsidiaries, have participated in thedevelopment o these papers in strict compliance with applicable competition laws. No specic commitmentson implementation o any technologies described in the papers have been made. Users o the papers shall maketheir own independent business decisions at their own risk and, in particular, without undue reliance on thisreport.

This publication may contain advice, opinions, and statements o various inormation providers and contentproviders. IFC does not represent or endorse the accuracy or reliability o any advice, opinion, statement or otherinormation provided by any inormation provider or content provider, or any user o this publication or otherperson or entity.

Input to technical papers

Experts in many organizations inputted to the technical papers, including (in alphabetical order):

Industry Co-chairs: KN Rao (ACC), Dominic Fernandes (ACC), R Bhargava (Shree Cement), Daniel Raju (ShreeCement), L Rajasekar (UltraTech), SK Herwadkar (UltraTech)

Industry Working Group: Sandeep Shrivastava (Ambuja Cements Ltd), Jitander Kumar (HeidelbergCementIndia), Sanjay Jain (Laarge), Sajid Khan (My Home Industries Ltd / CRH), AP Gupta (Shree Digvijay Cement Cimpor Group), R Gopi (Zuari Cement)

Cement Sustainability Initiative (CSI): Caroline Twigg

Conederation o Indian Industry: Kiran Ananth, K Muralikrishnan, KS Venkatagiri

National Council or Cement and Building Materials: SK Chaturvedi, SNM Khan, Pradeep Kumar, AK Mishra,YP Sethi

IFC: Michel Folliet, Alan Miller, Yana Gorbatenko, Sushil Anand, Rajesh Miglani, Sivaram Krishnamoorthy

Expertise was also provided by numerous organizations including ABG Cement, ACC Techport, ATS Conveyors,Birla Corporation, Bureau o Energy Eciency (Gol), Bureau o Indian Standards (GoI), Cement ManuacturersAssociation (CMA), Chemtrols Industries Ltd, CP Consultants Ltd, Central Pollution Control Board (Gol), DalmiaBharat Cement, Danoss, Department o Industrial Policy and Promotion (Gol), Emergent Ventures India Ltd, Ernstand Young, Flaktwoods, Gujarat Sidhee Cement, Holtec Consulting Pvt, IKN, India Cements, Institute or IndustrialProductivity, International Energy Agency, Jaypee Group, JFE Engineering, Loesche India, Ministry o Science andTechnology (GoI), Reliance Cement, Schneider Electric, Shakti Sustainable Energy Foundation, Thermax India,Thyssenkrupp Industries India, Transparent Energy Systems, The World Bank.


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Overview o the Indian cement industry

The Indian cement industry, the second largest ater China, has achieved an installed capacity o around 300million tonnes (2011) and is anticipated to reach 320 million tonnes by 2012 and 600 million tonnes by 2020. With99% o the installed capacity using dry process manuacturing, the Indian cement industry has been adopting

latest technologies or energy conservation and pollution control as well as online process and quality controlbased on expert systems and laboratory automation.

On the energy conservation ront, the best levels achieved by the Indian cement industry, at about 680 kcal/kgclinker (cli) (2.85 GJ/ton clinker) and around 66 kWh per tonne cement, are comparable with the best achievedlevels in the world. However, a large number o plants installed beore the 1990s are operating at relatively highenergy consumption levels. Although some o these legacy plants have been modernized to a limited extentby retrotting new technologies, they should, on priority, bring their energy consumption levels closer to thebest achieved levels in the industry by urther modernization and adoption o best available processes andtechnologies.

On the technological ront, Indias cement industry has largely adopted the state-o-the-art manuacturingtechnologies. However, systems or cogeneration o power through waste heat recovery and technologies or

low NOx and SOx emissions have not penetrated signicantly.

The industrys eforts towards emissions control, preservation o ecology and voluntary initiatives, such asCorporate Responsibility or Environmental Protection (CREP) are laudable. The Indian cement industry deservescommendation or its long-standing eforts towards reduction o its carbon ootprint by adopting the bestavailable technologies and environmental practices. This is reected in the industrys achievement o reducingCO emissions to an industrial average o about 0.719 tonne CO per tonne o cement (direct and indirect emissionsrom Scope I and Scope II) rom a substantially higher level o 1.12 tonne CO in 1996.

The initiatives adopted by the Indian cement industry towards utilization o secondary materials are evidentrom the act that production o blended cements (Portland Pozzolana Cement (PPC) and Portland Slag Cement(PSC)) in the country in the year 2010-11 was as high as 67%, as against only 36% in 2000-01. Indias cement

industry annually consumes around 45 million tonnes o y ash rom thermal power plants, as well as consumingthe entire quantity o around 10 million tonnes o granulated blast urnace slag generated by steel plants in thecountry.

The cement industry has also sharpened its ocus on the utilization o alternative uels by increasingly usingnewer industrial, municipal and agricultural wastes. There is a substantial scope to enhance waste utilization,particularly hazardous and combustible wastes, and the industry is soon expected to achieve international bestpractices o waste utilization.

Possibilities o implementation o the technologies covered in these technical papers will depend on existingplant technology, layout and site constraints. The extent o reduction by implementing these technologies willalso depend on several inuencing parameters such as availability and quality o AFR, raw materials properties,etc. Thereore all the technical papers may not be applicable to any given acility. The maximum greenhouse

gas emission reduction potential o each lever is only indicative and may or may not be ully achievable orall acilities. Thereore simply adding up the reduction potential o each technology in order to calculate totalpotential may not be appropriate


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Best Available Technologies (BAT) or a modern cement plant

Introduction

India is the worlds second largest cement producing country ater China. In 2000, the countrys annual capacity

was around 120 million tonnes, and, a decade later in 2011, it is estimated to be around 300 million tonnes. Thisshows a cement capacity growth rate o approximately 10% every year. The Indian cement industry is ar moreadvanced than many other countries in specic energy consumption in both thermal and electrical energy (energyuse per unit o production). (Best achieved numbers being 680 kcal/kg o clinker (2.85 GJ/ton clinker) and 66 kWh/ tonne o cement). Many plants have already retrotted or have chosen a better design at the commissioningstage itsel, thereby creating a better platorm or enhancing energy eciency. For a modern cement plant withthe best available technology, the ollowing eatures have to be taken into consideration:

Mines1

For medium and sot materials, a surace miner with single stage impact crusher and wobblers can be chosen,whereas or hard materials, conventional mining with two-stage crushing can be selected. Advanced mining with

mine plan sotware would result in reduced raw material additives, over-burden handling and enhanced minelie. Overland conveyors to transport crushed limestone will be benecial or long distance transport betweenmines and plants.

Other mine management measures are the installation o mobile crushers or productivity improvement, andradio controlled mines machinery monitoring system or better control and optimization.

Crusher discharge: a cross belt analyzer can be installed to ensure the quality and to enhance the mines lie.Stacker and reclaimer with higher blending ratio (o 10:1) can be adopted by design.

Raw Mill

( For limestone with a moisture content o more than 5% and hardness classied as medium to sot, Vertical

Roller Mills (VRM) with the latest generation classier are being installed with the ollowing:( Mechanical recirculation system

( High eciency ans with High Tension (HT) Variable Frequency Drive (VFD)

( Automatic sampler and cross-belt analyzer in the mill eed or better quality control

( Adaptive predictive control or mill operation

For limestone with low moisture content (less than 3%), roller press with separator in nished mode can beinstalled with the ollowing:

( High eciency separators and cyclones

( Automatic sampler and cross-belt analyzer in the mill eeding or better quality control

( Adaptive predictive control or mill operation

Silo

( Continuous blending silo with high blending ratio (10:1)

( Mechanical conveying system or all material transport

( For silo extraction, gravimetric eeding system or all ne material with an accuracy o over 1%

1 In India, 'Mine' reers to both open cast / surace mine (in Europe, this is 'quarry') and underground mine


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Coal mill

( Stacker and reclaimer with high blending eciency to use diferent coal grades with alternativeuel

( Vertical roller mill or grinding

( Gravimetric eeding system

( Hot gas source rom preheater to ensure saety and coal drying

( Coal mill ans with VFD and high eciency

( High pressure blowers or ne coal transportation with increased phase density

Cement mill

Preerred options or cement grinding could be among

( Vertical roller mill or grinding using cooler vent air as the hot gas source

( Roller press and ball mill combination with high eciency separator

( Roller press in nish mode

Packing plant

( Cement silo extraction with air slide and blower

( Electronic packers

( Double-decker wagon loader

( Provision or bulk dispatch and bag dispatch, depending on plant context (e.g., rural or urbanlocation)

Minimal Waste Heat Concept

While the current trend among cement plants is to adopt WHR systems by design or retrot, uturecement plants are expected to see the emergence o a minimal waste heat recovery concept, whereinsuitable system design and technology developments would ensure elimination o all waste heatgenerated rom the system itsel. Experts strongly predict that this system would be ar more ecientthan utilizing the waste heat or power generation as in present cement plant designs.

Dust Control Equipment

The installation o pulse-jet baghouses with membrane bags or all process applications, and pulse-jetbag lters with non-membrane bags or non-process applications. For clinker coolers, either ElectrostaticPrecipitator (ESP) or bag lters with a Waste Heat Recovery (WHR) system can be installed.


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Technical paper no.1: Electrical and thermal energy eciency improvements inkilns and preheaters

Current status

Kiln and preheater system in Indian cement industry has achieved very high levels o technology adoption andenergy eciency levels. With signicantly higher productivity levels and installation o latest energy eciencyand automation control devices, these systems are operating at one o the best perormance measures in theworld.

Indias modern cement plant is equipped with six stage (or ve stage in certain clusters having higher moisturelevels in limestone) preheater with in-line or separate-line calciner (depending on the rated kiln output), kilnswith volumetric loading o about 5--6.5 tpd/cu.m and advanced automation systems. Continuous EmissionMonitoring Systems (CEMS) are also being increasingly adopted in new as well as existing kilns. However, while theproductivity levels o existing kilns have been increased to meet growing demand, enhanced energy consumptiondue to increased velocity resulting in higher pressure drop and reduced heat transer ofers potential areas orimprovement.

The installation o high eciency (and low pressure drop) cyclones ofers signicant energy eciency improvementopportunity in cement kilns. With several design innovations, a six-stage preheater system ofers pressure drop oabout 300 mmWC in latest designs. For existing plants, installation o additional preheater stages (wherever civilstructures permit rom 4/5 stages to 6/7 stages) or increased heat recovery and computational uid dynamics(CFD) studies or reducing the pressure drop in preheater cyclones, along with necessary modications oferurther electrical and thermal energy eciency improvement opportunities.

With several advancements in reractory properties, such as thermo-mechanical and alkali resistance, cementkilns today can minimize the radiation losses as well as handle increased AFR substitution rates. The kiln maindrive is also undergoing substantial improvements with better gears and lubrications system. Automation andcontrol systems, such as adaptive-predictive control systems and online control systems or ame, ree-lime, inletNOx are very efective or better throughput, smooth operation and control.

Oxygen enrichment as an option or energy eciency (by reducing the combustion air requirements) as well asincreased alternative uel utilization (or kiln ring uels, by providing better ame temperature and ensuringcomplete combustion) can ofer signicant energy eciency, as well as assist in increased substitution rates.Higher investment costs or installing oxygen separation system rom air, storage and handling systems and therelated saety issues are the deterrents, afecting the economics o increased adoption o oxygen enrichment inthe Indian cement industry today.


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Technology proposed

( Low pressure drop and high eciency cyclones

( High tension variable requency drive or precise control o preheater ans

( Computational Fluid Dynamics (CFD) studies to reduce the pressure drop and improve energy eciency( Installation o additional preheater stages in older kilns

( Improved insulation or minimizing radiation loss in kiln and preheater sections

( Adaptive-predictive control systems or precise control o kiln system, increased productivity and betterenergy eciency

( Online automation systems or ame control, ree-lime and inlet NOx, among others

( Installation o additional preheater string or energy eciency and productivity increase requirements

( Online thermograph scanning and triggering corrective action to reduce kiln heat loss

Future technologies (under R&D)

The Indian cement industry is also keen to explore emerging developments, using kilns with zero waste heatconcept (design to utilize all waste heat in process itsel without a separate WHR system), heat recovery romkiln shell radiation, uidized bed combustion kilns, cogeneration o cement and power, limestone enrichmenttechnology (or utilizing low grade limestone), and so on when it emerges rom design to pilot/implementationstage. These practices are expected to elevate the Indian cement industrys energy and productivity perormancelevels to greater heights.

Anticipated benets

Thermal savings: 15 20 kcal/kg clinker

Electrical savings: 2 3 kWh/mt clinkerCO reduction potential (direct and indirect): 7 10 kg CO

2/mt clinker

Primary inuencing parameters

( Present level o technology adoption and specic energy consumption

( Raw material moisture

( Need or increased throughput rom existing kiln

( Electric power and uel cost

( GHG intensity o present power generation and uel combustion

Cost estimation

( Depending on the extent o absorbing the technology proposed and the inuencing parameters, costcould vary between INR 20 million to 60 million (approximately USD 400,000 to USD 1.2 million)


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Conditions, barriers and constraints

Technical

( Layout constraints/civil structural capability or stage addition

( High moisture limestone restricts the number o stages in the preheater( Burnability o raw mix

Policy

( Indias stringent environmental norms, necessitating installation o additional equipment, might increaseuture energy consumption

( Logistics/availability and quality concerns o coal, and quality concerns o raw materials and poweramong others

Financial

( Longer shutdown time or major modications

( Extended return on investments or certain initiatives, i only energy eciency benets are taken intoaccount

( Higher investment and operating costs or oxygen enrichment


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Technical paper no. 2: Latest generation high eciency clinker coolers

Current status

The Indian cement industry, over the last several years, has increasingly adopted reciprocating grate coolers with

great success. While rotary coolers have been completely phased out, several installations with planetary coolersare still in vogue. With more than 50% o cement produced rom kilns less than 10 years old, reciprocating gratecoolers have become common practice in the industry today, with cooler loading o about 4550 tpd/squaremetre (m2) o cooler area. Enthalpy rom hot clinker is recovered to preheat the incoming secondary and tertiaryair to improve thermal eciency. Based on the cooling eciency, technology adopted, and desired clinkertemperature, the amount o air used in this cooling process is approximately 2.53 kg/kg o clinker.

Conventional grate coolers provide a recuperation eciency o 5065%, depending on the mechanical conditionand process operation o the cooler. This corresponds to a total heat loss rom the cooler o about 120150 kcal/kg clinker. Several cement kilns in India, as a result o continuous productivity increase measures, are operatingat signicantly higher cooler loading range than rated, with a range o 5065 tpd/m o cooler area; increasingthe total heat loss rom the cooler.

The reciprocating cooler has undergone signicant design developments; the latest generation clinker coolersofering better clinker properties, and signicantly lower exit gas and clinker temperatures. As a direct consequence,secondary and tertiary air temperatures ofered by latest generation coolers have also increased to about 1,250Cand 1,000C, respectively. The cooling air requirements o such coolers have also gradually reduced to about 2.22.4 kg/kg clinker.

While it is very attractive to adopt latest generation coolers or new plants by design, retrotting existingconventional reciprocating coolers with latest generation coolers also ofers a signicant potential or electricaland thermal energy saving in the Indian cement industry. The total heat loss o latest generation clinker coolersis less than 100 kcal/kg clinker, and has a recuperation eciency in the range o 7580%.

Future technologies under development

With increasing thermal eciency in the kiln and preheater system, it is necessary or clinker coolers to becapable o supplying reduced secondary and tertiary air volumes with higher recuperation eciency. Severalimprovements in clinker cooler technology in terms o better air distribution or reduced cooling air requirement,efective conveying system or better transport o clinker and mechanical stability o cooler, optimum under-gratepressure and heat shields, are under development. Vertical shat coolers with recuperation eciencies o morethan 80% are under development which could urther result into specic heat and CO reduction. The Indiancement industry can thereore expect urther reductions in cooler heat loss and increased energy eciency.

Anticipated benets

Thermal savings: 1030 kcal/kg clinker

Electrical savings: 01 kWh/mt clinker

CO reduction potential (direct and indirect): 810 kg CO2/mt clinker


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Technical paper no. 3: Energy eciency in grinding systems

Current status

Material grinding is the largest electrical energy consumer in cement manuacture. Thereore the Indian cement

industry, where energy costs contribute to a majority share in overall cement manuacturing costs, has adoptedthe most energy ecient technology or its grinding requirements.

For raw material grinding, the most commonly used grinding technology is Vertical Roller Mills (VRM), while ewolder acilities still operate with either ball mills alone or ball mills with pregrinder (the most commonly usedpregrinder is the mechanical crusher). Coal grinding has also gradually shited to VRM use, while a ew olderacilities still operate with air-swept ball mills. With an increased use o petroleum coke and imported coal and,thereore, enhanced coal neness requirements, VRMs are gradually becoming the most preerred option or coalmills.

Indias cement grinding uses has multiple grinding systems: ball mills; ball mills with pregrinder (the commonlyused pregrinders are High Pressure Grinding Rolls (HPGR) ollowed by vertical mills as a pregrinder to ball mills);VRM or clinker grinding and, in certain grinding locations, ball mills and VRM (grinding clinker and additive

materials separately and blending).

The newest plants in the Indian cement industry (installed in the last 10 years and contributing over 50% ocement manuacturing capacity) have VRM or raw material and coal grinding and VRM/ball mill with HPGR orcement grinding.

The selection o grinding mill type depends mostly on the moisture content and material hardness. VRM, widelyaccepted or the combined drying and grinding o moist raw materials and coal and or low energy consumption,has been widely used or all three grinding requirements. Several improvements in design and operation othe mill and other equipment in the grinding circuit are resulting in less energy consumption and improvedreliability.

The introduction o an external re-circulation system or material, adjustable louvre ring, latest generation

classier and modication o mill body to improve the air and material trajectories are examples o such changeswhich increase throughput and improve energy eciency.

While VRM has been the preerred option or raw material and coal grinding, clinker grinding still provides severaloptions or Indian cement manuacturers. The closed circuit ball mill with high eciency separator is the mostcommon type o clinker grinding system used. A comparative analysis o various options available or cementgrinding compared to a closed circuit ball mill is provided below:


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Comparative analysis

No. Parameters Base case Alternative1 Alternative2 Alternative3

Closed CircuitBall Mill (CCBM)

Semi nishgrinding ballmill and HPGRpregrinder

HPG nish mode VRM

1. Communition technique

Impactandattrition withthe grindingballs

Compressionin RP. Attritionin ball mill

Compression Compression

2. Feed size90% passing25 mm sieve

Up to 2 timesthe gap width

Up to 2 timesthe gap width

Up to 75 mm

3. Air ow requirement Low Low Low High

4. No. o auxiliary equipment More More Less Less

5. Maintenance Low High High Medium

6.Expected specic powerconsumption, kWh/tOPC @ 3,400 cm/gm

32 34 26 28 26 28 24 26

7. Ease o operation High Medium Medium Low

Anticipated benets

Thermal savings: nil

Electrical savings: 6 10 kWh/mt cement

CO reduction (indirect): 7 12 kg CO/mt cement


( Material (raw material, coal and clinker) properties

( Output size requirement (neness and particle size distribution and so on)

( Material science and grinding technology

( Durability o construction material (reliability and maintenance, among others)

Cost estimation

Since cost estimation or individual mills or various grinding requirement is dicult, a typical cost estimate is

compared below:( Ball mill with closed circuit: X (X given as an example unit)

( Vertical roller mill (VRM): 2.3 2.5 X (that is to say, 2.32.5 times more than ball mill)

( Roller press in nish mode: 1.8 2 X (that is to say, 1.82 times more than ball mill)

( Roller press with ball mill: 2 2.2 X (that is to say, 22.2 times more than ball mill)


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Technical

( Roller press circuit could have a capacity limitation, whereas higher capacity is possible with VRM

( Additional undamental research in material science is requiredPolicy

( Absence o policy standards linking strength and neness with application

Financial

( Retrot costs to upgrade grinding technology is very high; long payback periods (o about 6-10 years) ionly energy savings are considered


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Anticipated benets

Thermal savings:3 5 kcal/kg clinker

Electrical savings: 0 0.5 kWh/mt clinker

CO2 reduction: 2 4 kg CO2/mt cement


( Recuperation eciency o clinker cooler

( Energy eciency and throughput increase considerations

( Extent o utilization o alternative uels

( Kiln capacities

( Present electrical and thermal energy cost

Cost estimation

New installation o burner: INR 20 30 million per kiln (approximately USD 400,000 600,000 per kiln)


Technical

( Layout constraints can pose certain barriers in some acilities

Policy

( None to date

Financial

( High retrot costs and long payback periods to replace uni-ow with multi-channel burners


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Technical paper no. 5: Energy eciency improvement in process ans

Current status

Process ans are large electrical energy consumers in cement manuacture, second largest to grinding. Indias

cement industry has ocused on process ans or several years in its pursuit or increased energy eciency, and hasreduced operating costs in the process. Modern cement industry ans are designed or higher energy eciency,higher wear resistance, lower material build-up and efects o erosion, better speed control, low vibrations andhigh operational stability.

In a number o plants, high energy ecient ans have replaced inecient process ans by both design and byretrot o energy saving speed control devices, eliminating the control damper have been a regular eature inseveral plants. Higher pressure drops in inlet and outlet duct systems can be analyzed and reduced by using CFDtechnicques. A ew o the widely used process ans, such as preheater ans, raw mill ans, coal mill ans, coolerans, and so on consume over 40% o the total electrical energy in cement manuacture. With better constructionmaterials or ans and with design optimization, ans with a higher operating eciency are available or all cementindustry applications.

Precise design specications, reduced margins between requirement and procurement, and a choice oappropriate control systems can ofer a signicant energy saving opportunity. Several studies indicate that excessmargins bufered in at various levels are one o the major reasons or deviation between design specicationsand operating requirements. Experts suggest that optimum margins or capacity and heat should not be over10%, resulting in an enhanced power consumption o about 25%. To curtail this margin and ofer precise processcontrols, the choice o an appropriate speed control device becomes essential. Speed control is the most efectiveway o capacity control in centriugal equipment; the choice o right speed control mechanism ofers additionalmargins or eciency improvements.

Among the various options available or speed control o High Temperature (HT) process ans, such as Grid RotorResistance (GRR) control, Slip Power Recovery Systems (SPRS), and so on. HT Variable Frequency Drives (VFD) areound to be the most suitable speed control mechanism, considering the precise control ofered and the low

inherent system energy losses. Hence, or all major ans, the right selection o an with HT VFD as a preerredspeed control ofers the maximum energy saving. Wherever VFDs are installed, the elimination o control damperis preerred. However, wherever the process needs damper control, a low pressure drop damper can be installed,such as aerooil multi-louvered damper or cooler ans.

For all other Low Temperature (LT) process ans, the benets o installing LT VFD have been proven. The inherentmargin that results in additional power consumption o up to 25% can itsel pay back the cost o an LT VFDretrotted or energy saving.


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While emphasizing the operating eciency o ans, it is important to consider the best available ecienciesofered to evaluate economics either by design or or a retrot installation:

No. Fans Efciency

1. Preheater an 82 84%

2. Raw mill an 82 84%3. Cement mill separator an 82 84%

4. Cooler ans > 80%

5. All auxiliary and bag lter ans > 75%

6. Reverse air bag house an 75 80%

7. Cooler vent an 75%

Process ans, with the eciency levels mentioned above and with an appropriate speed control mechanismwould be the preerred option or optimum energy eciency. Retrot to replace low eciency ans with ans ohigher operating eciency, and the installation o appropriate speed control devices, is generally paid back bythe energy saving these can deliver.

It is however important or the industry to constantly monitor the perormance o existing ans, and to evaluatethe cost economics or replacement. Whenever the return on investment meets the organizational norms, it isadvisable to immediately replace existing ans with those o higher operating eciency available at that time. .This will certainly help to signicantly lower the overall cost o ownership o such process ans.

Future technologies (under R&D)

While several studies are underway to urther improve the eciency o process ans through better constructionmaterial, blade angles, gaps, entry velocities, etc, one promising research area underway looks at increasing theoperating pressures o axial ans to replace centriugal ans, wherever easible. Axial ans ofer signicantly higheroperating eciencies than centriugal ans, though the pressure rise o axial ans is signicantly lower than ocentriugal ans. I axial ans could ofer sucient pressure rise to replace a centriugal an, this would certainlyresult in a signicant lowering o power consumption with better operating eciency.

Anticipated benets

Thermal savings: none


CO2

reduction (indirect): 5 8 kg CO2/mt cement


( Present levels o energy eciency and specic energy consumption

( Layout constraints

( Cost o electrical energy


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Cost estimation

( Cost or HT VFD: INR 12,000 15,000 / kW (approximately USD 240 300 / kW)

( Cost or LT VFD: INR 6,000 10,000 / kW (approximately USD 120 200 / kW)

( Cost or an: INR 4,000 6,000 / kW (approximately USD 80 120 / kW)


Technical

( Layout constraints can pose certain barriers in ew acilities, where the ideal duct system cannot beaccommodated

Policy

( None to date

Financial

( Retrot costs in some cases could be high


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Technical paper no. 6: Energy eciency improvement in auxiliary equipment in thecement manuacturing process

Current status

Auxiliary equipment such as conveyors, elevators, blowers, compressors and pumps, consuming about 10% ototal electrical energy o cement manuacturing process, are vital or transporting the material and gases romone manuacturing stage to another. For enhanced energy eciency, the optimum perormance o auxiliaryequipment becomes important within the overall energy perormance o the manuacturing acility.

Technologies proposed

( Pipe conveyor

Pipe conveyors can cause both horizontal and inclined curves in the material ow path. Due to this inherentcharacteristic, a single pipe conveyor can replace several traditional conveyors systems, removing the need ortranser points with relevant steel structures, dust control systems, and so on. Larger riction o material insidethe tubular belt allows a higher slope angle o the conveyor: a single pipe conveyor can replace the combination

o belt conveyor and bucket elevator. The cross-section o a pipe conveyor is smaller than the equivalent beltconveyor, thereore space requirements are minimal and the weight o structures and gantries is lower.

( Centriugal blower

One o the latest advancements in the ne material transport system (ne coal eeding to kiln, calciner, y ashand cement transport) is the use o a centriugal blower, which has a higher design eciency compared withconventional twin lobe blowers. It also comes with an inbuilt Variable Frequency Drives (VFD), which acilitatesprecise control and optimization o phase density (material to air ratio). With these changes, reductions o over30% in specic power can be achieved.

( Centriugal compressor

Centriugal compressors are generally used or high capacity application i.e., compressed air requirement to

more than 2,000 Cubic Feet per Minute (CFM). The specic energy consumption is lowest compared with othertypes (0.13kW/CFM at seven bar pressure against 0.17kW/CFM o screw compressor). With an increased demando compressed air, it is benecial to have a centriugal compressor to cater to the base demand and achieve thelowest specic energy consumption.

( VFD or pumps and screw compressors

One o the best methods o capacity control is the use o VFD. The latest VFD has better reliability (available in bothLow Temperature (LT) and High Temperature (HT) voltages), a higher operating range and reduced harmonics.The installation o VFD in the case o pumps can ensure zero recirculation and valve loss. VFD in a compressor canresult in constant pressure (which improves the system reliability and stability), zero unloading, and thereorepower reduction.

( High efciency pumpsPumps in the cement industry, although small energy consumers, can ofer energy saving opportunities. Thetypical use o pumps (largely centriugal) in the cement industry is or cooling applications, in Gas ConditioningTowers (GCT) (in a ew plants) and transerring raw/resh water to the acility. Studies in several plants indicateineciency on two accounts: mismatch between design parameters and operating requirements, and eciencyimprovement by retrotting with latest pumps.


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( Wobbler screen or crusher

A wobbler eeder with a series o shats installed beore the crusher prevents the undersized material romeeding into the crusher, thereby avoiding the generation o excessive ne materials. They have been successullyoperating with moisture content o less than 5% and the reduction in the specic energy consumption o the

crusher can be as high as 0.5 kWh/mt o material.( Automation or auxiliary equipment

It is gradually becoming a regular practice to incorporate automated auxiliary equipment, comprising pumps,bag lter ans and compressors. Such automation includes the interlocking o auxiliary equipment with the mainprocess equipment; compressed air-purging based on a pressure drop across the bag lter; eliminating idlerunning, and controlling parameters like ow, pressure based on process variation/demand.

Anticipated benets

Thermal savings: none

Electrical savings: 0.5 1 kWh/tonne o cement

CO2 reduction (indirect): 0 1 kg CO2/tonne o cement


( Present levels o energy eciency and technology adoption

( Cost o power

( Layout easibility

Cost estimation

( Cost or pipe conveyor: INR 80,000 100,000 / meter o length (approximately USD 1,600 2,000 / metero length)

( Cost or LT VFD: INR 6,000 10,000 / kW (approximately USD 120 200 / kW)

( High eciency pump: INR 4,000 10,000 / kW (approximately USD 80 200 / kW)

( Turbo blower: INR 23,000 27,000 / kW (approximately USD 460 540 / kW)


Technical

( Layout could pose certain constraints in implementing some o the proposed options

Policy

( None to dateFinancial

( Higher investment and operating costs o latest auxiliary equipment could be a deterrent


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Technical paper no. 7: Energy eciency improvement in Captive Power Plants(CPP)

Current status

In its pursuit or reliable and high quality electrical power, over 53% capacity o Indias cement industry has adoptedCPP or their internal power requirements. The initial trend was to explore heavy oil-red diesel generator sets tomeet part demand in the event o grid ailure. With a sharp rise in uel oil prices and requent outages o the grid,the industry has now completely shited to coal / lignite and petroleum coke-based thermal power plants as thepreerred CPP option. Additionally, multiple uel and biomass approaches are in practice.

The estimated average auxiliary power consumption in cement industry CPPs ranges rom 1013%, whereasthe best operating CPPs in the Indian cement industry operate at 5.86% o auxiliary power consumption. Asimilar range is also observed in the CPP heat rate; the average heat rate o all CPPs installed in the Indian cementindustry is about 3,200 kcal/kWh, and in the range o 2,5502,575 kcal/kWh in the better operating plants.

With such a large share o cement plants operating with CPP and leading to such a wide variation in auxiliarypower consumption and heat rate values, this ofers an excellent lever or energy eciency improvement and

Greenhouse Gas (GHG) emissions reductions. Energy eciency in CPPs could be achieved in two ways: energyeciency by design and energy eciency by retrot.

Energy eciency by design

With Indias cement industry capacity expected to double in the next 10 years, and CPPs becoming integral tocement plants, energy eciency by design or newer CPPs is imperative or low carbon growth o this sector.With coal still the preerred uel source to power CPPs, and considering Indian coals high ash content, the mostsuitable option would be to adopt the Circulating Fluidized Bed Combustion (CFBC) boiler with double/multiple(or increased heat rate) extracting turbine. Lack o availability o water might lead to the selection o Air CooledCondensers (ACCs) by design in orthcoming CPPs. Installation o latest combustion control systems, speedcontrol or major auxiliary equipment, such as boiler eed water pumps, Forced Drat (FD) ans and Induced Drat(ID) ans, auxiliary cooling water pumps and condensate extraction pumps and so on, would be essential bydesign. The target heat rate and auxiliary energy consumption values or newer CPPs should be 2,550 kcal/kWhand 6%, respectively.

Energy eciency by retrot

Renovation and modernization o steam turbines: the rst step in the Indian cement industrys pursuit or lowerGHG emissions in its CPPs would be to carry out a complete steam path audit or relatively old turbines. Isentropiceciency needs to be calculated and, depending on the results, reurbishment / replacement o the turbines canbe evaluated.

Circulating Fluidized Bed Combustion System (CFBC) in place o Atmospheric Fluidized Bed Combustion

System (AFBC)

The most commonly used boilers across CPPs are either AFBC or CFBC. Among the two, the latter is designed towork with a higher ash content coal, which is better suited or the Indian cement industry (Indian coal typicallyhas high ash content). It also results in a lower loss on ignition (LOI) and lower SOx and NOx emission levels.Its capacity ranges (usually available) are 65250 tph and it has an eciency o about 8890%. Usually AFBCboilers do not have eciencies more than 8485%. CFBC also has multi-uel ring capability (70% coal and30% alternative uel). The burner system and uidization system can also be modied to improve combustioneciency and thereby reduce the LOI in y ash.


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Vacuum pumps

Steam ejectors are widely used or maintaining a vacuum inside the condenser. The steam or its operation isusually supplied rom a Pressure Reducing and De-superheating System (PRDS), which reduces the main steampressure to the operating pressure o the ejector. But by doing so, motive steam, that has the potential to generate

more power, is lost. Ejectors could be powered rom the steam at low cost or can be replaced completely with avacuum pump.

Use o low grade steam or Vapor Absorption Machine (VAM)

VAMs are normally available above 100 TR (tonne o rerigeration). The installation o VAM is completely site-specic, and local cost economics must be taken into consideration (steam cost and electricity cost) in easibilityassessment.

Use o VFD in equipment with higher load variation

Most energy intensive equipment is over-designed and is controlled by means o dampers and control valves.Energy loss (due to pressure loss across the control system) can be avoided by optimizing the pressure withvariable requency drives. For example, VFD can be used to optimize the ow in Condensate Extraction Pump

(CEP), Boiler Feed Pump (BFP), Cooling Water Pump (CWP) and Auxiliary Cooling Water Pump (ACWP) (water side)and Primary Air (PA) ans, FD ans and ID ans (air and gas side).

Avoiding steam leakages: steam leakage is a visible indicator o waste and must be avoided. Steam leaks on highpressure mains are prohibitively costlier than on low pressure mains. In act, the plant should consider a regularsurveillance program or identiying leaks at pipelines, valves, anges and joints. By plugging all leakages, uelsavings may be high, reaching up to 5% o the steam consumption in a small or medium scale industry, or evenhigher in installations with several process departments.

Air Cooled Condensers (ACCs) are typically observed in cement industry CPPs due to shortage o water. OptimizingACCs by periodic perormance evaluation, utilization o coil mesh type water sprinkling systems and adoption oFiber Reinorced Plastic (FRP) blades or cooling tower ans (or its better aerodynamic prole and thereby lowerenergy consumption) and so on, could provide opportunities or CPPs to maintain or improve the perormance

o the ACCs and thereby o the complete CPP.Integrating CPP with the cement plant: considering its close proximity to cement manuacturing acilities, a CPPcan explore all possible opportunities or WHR or its preheating applications. Preheating o make-up water oro boiler eed water can be carried out by utilizing waste heat sources in the cement process, such as cooler ventgases (typically at 250300C), preheater hot gases (typically ranging around 280350C) and kiln shell radiationloss. Wherever the WHR option is still not explored, heat recovery to partially meet the CPP requirement ofers anexcellent opportunity at some cement plants.

Anticipated benets

Thermal savings: 100 250 kcal/kWh

Electrical savings: 20 30 kWh/mw o CPP capacityCO

2reduction: 0.05 0.1 kg CO

2/kWh


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( Present level o technology adoption in CPPs

( Cost o coal, thereby CPP generated power

( CO2 intensity o uel( Availability o water or cooling requirements

( Plant Load Factor (PLF)

Cost estimation

Depending on the extent o absorbing the technology proposed and the inuencing parameters, cost could varybetween INR 10 million and 30 million (approximately USD 200,000 600,000)


Technical

( Inconsistent coal quality is a major concern or some CPPs

( Layout constraints can pose certain barriers in some acilities

( Air cooled condenser perormance

Policy

( Grid connectivity or increased PLF o CPPs is a major concern

Financial

( Retrot costs in some cases could be high

( Installation o storage and blending system or multi-uel usage needs high capex, and has a longer

payback period


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Technical paper no. 8: Increased Renewable Energy (RE) use in cementmanuacture

Current status

India today ranks among the worlds top ve countries in terms o Renewable Energy (RE) capacity with around20 GW installed base. This represents about 11% o Indias total power generation capacity (an increase rom 3% 11% in the last decade). Future targets are promising: Government o India (GoI) targets aim to achieve over 20%o the countrys total power generation in the next decade with an installed capacity o over 70,000 MW. GoI hasalso recently launched two unique and ambitious national missions; the National Solar Mission seeks to acilitatethe generation o 20,000 MW o solar power by 2022, and the National Biomass Mission aims to tap bioenergypotential o over 25,000 MW.

A modern one MTPA capacity cement plant requires about 15 MW o installed capacity o electrical energy or itsoperation. The use o renewable energy up to 100% is site-specic and may be possible in some cases. Expereincerom one CSI member company shows that higher renewable energy rates can be achieved i older, smallercapacity wind turbines are replaced by new technology, higher capacity wind turbines, and solar PV systems can

be erected on the same site, to gain rom both wind and solar power in a single system.The estimated potential and the area required to generate power or renewable energy technologies are givenbelow:

No. Technologies

Estimated

potential

(MW)

Tapped

potential

(MW)

Area required

1. Wind power 48,561 14,989 20 25 acres/MW

2. Biomass power 16,881 1,083 1 1.5 acres/MW

3.

Biomass

cogeneration 5,000 1,779 0.75 1.2 acres/MW

4. Waste to power 2,700 73 4 5 acres/MW

5. Solar PV 20,000 17.82 5 acres/MW

6. Solar thermal 35,000 unknown 7 12 acres/MW

7. Small hydro 15,385 3,105.63 unknown

Options available

( Wind power

Several cement plants have installed wind arms in many locations across the country. Wind power also hasthe advantage o wheeling (power transmission through national electricity grid) and banking (eeding powergenerated to the grid or use at a later time), thereby yielding higher benets.


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( Biomass

Stand-alone biomass power generating units; the cost o biomass is increasing, making it expensive or powergeneration.

( Waste to power

Technical and administrative issues mean waste to power is not suitable or installation at all plants, and a plantwill need to carry out a good community engagement process or local acceptance.

( Solar PV

One o the major reasons or very ew solar PV installations is the price constraint and the requirement o large area.Cement plants can install these in a diferent location and can wheel the power, or can install solar PVs in usedmined areas, or or pumping, street lighting and air conditioning. The estimated cost o solar PV is around INR 140million/MW (approximately USD 2.8 million), potentially dropping to around INR 70 million/MW (approximatelyUSD 1.4 million) in the coming decade, making it easier to undertake large installations (the cost o coal basedpower generation today, or comparison, is about INR 45 million/MW) (approximately USD 900,000).

( Solar thermal

Solar thermal can be used or hot water generation and chilling purposes (Vapor Absorption Machine or VAM).There is a good potential or solar thermal installation in cement plants.

( Small hydro power generation

Several initiatives have been conducted to tap larger hydro plants, but ew in small hydro plants, thereby yieldingopportunity to venture more into this area.

Anticipated Benets


Electrical savings: 30% o electrical energy ofset through RE use

CO2 reduction: 24 kg CO2/tonne o cement (or 30% use o RE)


( Availability o appropriate sites or RE installation (on-site/of-site)

( Cost o electrical power

( Government incentives/policies or increased RE utilization

( Innovative developments or integrating RE within the cement manuacturing process


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Cost estimation

No. TechnologiesCapital cost (INR

million / MW)

Capital cost

(approx. USD

/ MW*)

Typical Plant Load

Factor (PLF) (%)

1. Wind power 50 60 1 1.2 million 20 30

2. Biomass power 30 45 600,000 900,000 70 75

3.Bio-mass

cogeneration34 40 680,000 800,000 45 55

4. Waste to power 30 600,000 75 80

5. Solar PV 140 2.8 million 20 30

6. Solar thermal 120 2.4 million 25 40

7. Small hydro 40 50 800,000 1 million 19 40

* USD 1 = INR 50


Technical

( Sites o high wind energy potential have already been utilized; in some cases, with lower capacity windturbines

( Raw material availability or continuous eeding o biomass is a major concern

Policy

( Municipal Solid Waste (MSW) could be an excellent option or power rom waste; but lack o enablingpolicies is a major deterrent

( Enabling policies or increased RE generation, such as attractive eed-in tarifs, wheeling and bankingpolicy, etc are commendable in a ew states, but these are not widespread across the whole country

( Absence o policy or ofshore wind power generation

( Higher import duties and taxes increase initial investment requirements

Financial

( Initial investment or several RE based power plants is very high, and oten cannot meet the companysreturn on investment targets


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Technical paper no. 9: Energy eciency improvement in electrical systems

Current status

Some o the plants in the Indian cement industry are already equipped with the latest available technology in

electrical systems, like intelligent Motor Control Centers (MCC) and Energy Management Systems (EMS); andso on. Such technologies can be replicated in other plants. These systems occupy a prominent role in controlschemes, housing a comprehensive array o control and monitoring devices. MCCs have moved rapidly to includethe latest component technologies, and integrating these advanced technologies presents a major opportunity to transorm islands o data into useul inormation that minimizes operational downtime. The equipment ismostly ound to be loaded at around 5070%; here voltage optimization can yield energy savings. Frequencyoptimization also holds strong potential i the plant is not synchronized with the grid and is running in islandmode. Plants can go as low as 48Hz as the generating requency. Lighting voltage generally observed in industryis on the higher side; but can be reduced to around 210215 V without decreasing the lux levels too much.

Technologies proposed

( Energy Management System (EMS)Measurement is vital in energy eciency improvement activities. Energy management systems help in measuringall important parameters required or better energy management.

( Use o EFF-1 (premium eciency) motors

Motors are the major consumers o electrical energy in any industry. The use o high eciency motors substantiallyreduces energy consumption as a whole. The use o energy ecient motors can be adopted in the design stageas well as a retrot option.

( Light Emitting Diode (LED) and magnetic induction lamps or lighting

The lighting system consumes nearly 5% o the total electrical energy consumption o a plant. The use o LightEmitting Diodes (LEDs) and magnetic induction lamps or illumination has become common practice in many

industries. Both LEDs and magnetic induction lamps consume only one quarter o the energy consumed by otherelectrical light sources.

( Maintaining near to unity power actor in CPP

In a synchronized system, i.e., when the CPP and grid are synchronized, the power actor o the CPP end is usuallymaintained at a lower level, so as to maintain a higher power actor at the grid end. This is done to decreasethe reactive power consumption rom the grid and avoid penalty. However, near to unity power actor can bemaintained at both the ends by installing capacitor banks at the load end. Care should be taken to avoid a leadingpower actor in CPP in partial load or no load conditions to avoid damage to alternator.

( Voltage optimization in motors and lightings

Any voltage supply above the motor rated voltage will result in higher voltage related losses. Thereore, it is

advised to optimize the supply voltage to the motors. All the Low Temperature (LT) motors are rated or 415Vonly, and hence the desired terminal voltage o motors could be in the range o 400415V with sucient reactivepower management. Similarly, or lighting circuits, the optimum voltage level is 208V or general lighting network.It is highly recommended to have a separate transormer or lighting with ne voltage control i possible.


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( Frequency mode optimization

In the case o a CPP operating in an island mode, an opportunity exists to optimize energy consumption othe connected load by reducing the supply requency. Since the power consumption o centriugal equipmentvaries with speed, any reduction in input requency results in reduced speed, thereby reducing the power

consumption.

Anticipated benets



CO reduction: 1.5 4 kg CO/mt cement


( Present level o energy eciency and specic energy consumption

( Current levels o technology adoption

( Cost o electrical power

Cost estimation

Investment costs depend on extent o absorption o energy ecient technologies and hence, overall costestimation is not ascertained.


Technical

( None to date

Policy

( None to date

Financial

( Prolonged return on investment is long or ew projects, such as change to LED lighting or installationo high eciency motors


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Technical paper no. 10: Utilization o advanced automation systems in cementmanuacture

Current status

An efective advanced automation and control system can bring substantial improvements in overall perormanceo the kiln, increased material throughput, better heat recovery and reliable control o ree lime content in clinker.Furthering the scope o automation in process control, quality is also maintained by continuous monitoring othe raw mix composition with the help o x-ray analyzer and automatic proportioning o raw mix components.New types o on-line bulk material analyzers have also been developed based on Prompt-Gamma-ray NeutronActivation Analysis (PGNAA) to give maximum control over the raw mix. The analyzer quickly and reliably analyzesthe entire ow online providing real time results. The latest trends in online quality control include computersand industrial robots or complete elemental analysis by x-ray uorescence, x-ray difraction techniques, onlineree lime detection, and particle size analysis by latest instrumental methods.

A ew other mine management measures could be installation o mobile crushers or productivity improvementand radio controlled mines machinery monitoring system or better control and optimization

The control and operation o kiln systems today is extremely complex, with properties o input uel and eedmaterials varying greatly and with product standards becoming increasingly stringent. Cement kiln operatorstoday encounter such sudden variations that dynamic control o the kiln is vital to achieve optimum results andlower manuacturing costs.

Some o the proven control systems employed or optimal perormance and quality are:

( Adaptive predictive control system

( Online shell scanner and reractory management

( Online NOx control

( Online ame control

( Online ree lime control( Flow measurement with advanced techniques

( Online measurement o kiln health

( Online Energy Management System (EMS) or drives and power generation

( Remote monitoring and operation or split location plants

Grinding systems are also undergoing signicant improvements, more rom their operation as the grindingtechnology has been witnessing only incremental improvements over the last several years. Automation andcontrol systems can signicantly improve the perormance o grinding systems by reducing the variations,maintaining precise particle size distribution and increasing throughput.

The adaptive predictive control system works based on sot sensors input, and the prediction mechanism workson set parameters. The operation o the system is predicted and corrective action is taken. I the correctivemechanism is not as per the requirement (or set value), the mechanism automatically renes itsel. The systemconstantly upgrades itsel to meet the system uctuations and keeps improving with time.


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Anticipated benets

Thermal savings: 6 8 kcal/kg clinker

Electrical savings: 3 6 kWh/mt clinker

CO reduction: 4 8 kg CO/mt cement


( Expert control systems simulate the best operator by using inormation, hence the expertise level ooperators is vital

( Present levels o operation eciency and energy eciency

( Existing plant conguration determines additional equipment requirement

( Uptime o control systems could be a concern

Cost estimation

( Cost o control system per kiln varies rom INR 4 million to 5 million (approximately USD 80,000 100,000)


Technical

( Uptime o control system is a concern. Typical uptime varies rom 70---80%, thereby afecting kiln control,energy eciency and overall return on investment

Policy

( None to date

Financial

( Return on investment could be long (about 4-6 years) in a ew cases (with low energy tarif)


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Technical paper no. 11: Increasing Thermal Substitution Rate (TSR) in Indian cementplants to 30%

Current status

Alternative uel use in the Indian cement industry is at very low levels; the countrys average stands at less than1% o Thermal Substitution Rate (TSR). Several nations globally have utilized cement kilns as an efective optionor their countrys industrial, municipal and hazardous waste disposal. This creates a win-win situation or boththe local administration and the cement plants: the administration utilizes the inrastructure already available atcement kilns, thereby spending less on waste management, and the cement kilns are paid by the polluter or saewaste disposal, as well as having their uel requirements partly met.

Various studies indicate that the Greenhouse Gas (GHG) emissions reduction potential through waste utilizationin cement kilns is extremely high. International experiences highlight extensive opportunities or such AlternativeFuel and Raw Materials (AFR) usage, or example the Japanese cement industry utilizes over 450kg o waste pertonne o cement manuactured, and European cement plants have a TSR average o about 40%. I the TSR in theIndian cement industry could increase to 30% by, or example, 2030, GHG emissions could reduce substantially;

to such an extent that it could make a diference in the overall countrys emissions. The typical types o wastesbeing used as alternative uels are industrial wastes (automotive, pharmaceutical and engineering industrywastes being the most common) and biomass-based uels.

The GHG emissions reduction opportunity through increased TSR is basically on two ronts: rst, biomass-basedalternative uels are considered carbon neutral (as its subsequent growth xes the carbon emitted during itscombustion), and second, the use o other alternative uels reduces the use o primary ossil uel (coal, petroleumcoke, and so on). These alternative uels would have otherwise resulted in equivalent emissions, i other modeso disposal, such as incinerators or land-lling are chosen instead o cement kilns. Both biomass-based and otheralternative uel types must be considered in the Indian scenario: an agrarian economy like India ofers severalbiomass-based alternative uels and the use o other alternative uels in cement kilns reduces the need o localgovernments or separate installations or waste disposal, such as landll sites or expensive incinerator acilities.

Cement kilns can, theoretically, operate with 100% TSR, thereby completely of-setting the need or primary ossiluels. However, several other enabling actors, such as the installation o adequate pre-processing and blendingacilities, and the availability o alternative uels without technical limitations (heat content, larger proportion odetrimental trace elements, chlorine, sulur and so on ) have to be considered.

Cement kilns can exhibit signicantly varying behaviour depending on the type o alternative uel substituted,and hence the technical competence o the industry should be adequate to ace these challenges which comealongside a TSR increase. With extensive national and global expertise available, the Indian cement industrytoday is technically ready or adopting higher TSR rates.

Increased TSR in the cement industry would be possible i the waste legislation in the country progresses in linewith the industrys increased need or alternative uels. First and oremost, a change in perspective amongst policymakers is required, to explore cement kiln utilization o waste disposal. Secondly, stringent waste legislation is

needed, which enables high heat content waste to be co-processed in cement kilns rather than in incinerators,wherein the heat content goes largely unutilized. It is important that the legislation related to cement kilns isas stringent as or dedicated waste acilities. Thirdly, to ensure availability and consistency o alternative uelquantity and quality, waste legislation in the country should enable efective waste collection, treatment andprocessing; by a new service industry sector which works as an efective intermediary between waste generatorsand the cement industry. The pricing o waste is also a key actor, both to ensure waste minimization at source (to


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reduce disposal costs or waste generators) as well as to ensure zero or negative cost to cement manuacturers(encouraging them to install the expensive handling, storage and ring acilities at their premises) or increasedTSR. The th key actor is the social acceptance o using wastes as alternative uels in cement kilns, both in thesociety in which the cement kiln operates, as well as among the cement user community.

Indias Municipal Solid Waste (MSW) management is also a matter o growing concern. The countrys urbanpopulation grew rom 290 million reported in the 2001 census to an estimated 340 million in 2008, and is projectedto reach 590 million by 2030 (McKinsey Global Institute, 2010). While Indias urban population grew by 230 millionin about 40 years (rom 1971 to 2008), the next 20 years is expected to bring a 250 million surge. This emphasizesthe rapid urbanization in India at an unprecedented rate. Such increasing urbanization rates would create higherdemand or MSW management, considering increasing income levels and evolving liestyle choices. Thereore,efective waste management practices become imperative or the sustainable growth o the country. The PrimeMinisters National Action Plan on Climate Change National Mission on Sustainable Habitat has also identiedurban waste management as a major component or ecologically sustainable economic development.

Indias industrial waste is also growing in volume: recent estimates indicate that around 6.2 million tonnes ohazardous waste is generated annually, o which around 3.09 million tonnes is recyclable, 0.41 million tonnescan be incinerated and 2.73 million tonnes can go into landll. Considering such signicant hazardous wastegeneration, local administration, civic bodies and policy makers ace challenges o efective and sae disposal.

There is, thereore, an urgent need to implement appropriate policies and practices in avor o co-processing inIndia, which can contribute towards the countrys waste management needs. It will also help industry to achievereasonable TSR in the cement manuacturing process.

To do this, the cement industry aces two-pronged challenges: rst, technical competence or handling increasedalternative uels needs to be built in the industry, and second, there is a lack o enabling waste legislation thatosters higher TSR. With such enabling legislation, certain cement kilns in India have exhibited peak TSR o up to12%. By virtue o adequate technical capability and enabling policies, the Indian cement industry can target 30%TSR in the years ahead.

Anticipated benets (or thermal substitution rate o 30%)

Thermal savings: 0 - 40 kcal/kg clinker (increase)

Electrical savings: 0 - 3 kWh/tonne o clinker (increase)

CO reduction (PPC): 70 - 150 kg CO/tonne o cement (net reduction)

CO reduction (PSC): 70 - 210 kg CO/tonne o cement (net reduction)

The Indian cement industry has limited experience o increased use o alternative uel in its cement

kilns. Wherever alternative uel has been used in Indian cement kilns (up to 10-12% TSR), alternate

uel is largely dominated by use o biomass. No / very marginal increase in energy consumption is

observed in such kilns at this TSR levels.

For target TSR levels o 30%, given the lack o experience in Indian kilns, increase in thermal

energy consumption o 0-40 kcal/kg clinker is based only on international experiences at increased

alternative uel usage levels.


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( Availability o alternative uels

( Fuel properties, suitability or utilization in cement kilns

( Maximum possible substitution rates( Negative efect on kiln throughput, electrical and thermal energy consumption

( Ease o regulatory procedures

Cost estimation

( Investment cost or increased alternative uel use would largely depend on the type o uel / raw materialsused and the TSR. While certain alternative uels, such as biomass can be relatively inexpensive to use,others may require expensive processing beore it could be used in kiln. Considering the diversity oalternative uels currently available and a TSR o 10% over next 5-10 years, the cost is estimated to varybetween INR 5 to 20 million (approximately USD 100,000 400,000).


Technical

( Efect o increased TSR on kiln production and specic energy consumption

( Complete understanding o impacts o minor constituents on long-term cement perormance

Policy

( Lack o waste legislation encouraging co-processing in the cement industry

( Non-existence o structured waste processing industry

( Lack o source segregation, collection, handling and logistics o MSW

( Lack o policy guidelines on the cost o alternative uels (negative, nil or positive cost)

( Complicated procedural system or co-processing (permits, test runs, inter-state waste transportationchallenges among others )

( Importance in consistency between legislation or cement kilns and or dedicated waste acilities

Financial

( Higher investment and operating costs o waste pre-processing acility

( No established pattern to evaluate the cost o alternative uel (negative, nil or positive cost)


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Impacts o increased use o alternative uels and raw materials in the cementmanuacturing process

Introduction

The potential benets o co-processing alternative uels and raw materials in cement manuacture, whencarried out in a sae and environmentally sound manner, are numerous. However, poor planning or inadequatepreparations, or using alternative uels and raw materials without understan

existing and potential technologies for carbon emissions reductions in the indian cement industry

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