INTEGRATION OF BIOGAS TECHNOLOGY INTO POWER GENERATION IN SRI LANKA

Transcription

1 INTEGRATION OF BIOGAS TECHNOLOGY INTO POWER GENERATION IN SRI LANKA H.A.S.C. WIJENAYAKE (118364P) Degree of Master of Science Department of Mechanical Engineering University of Moratuwa Sri Lanka September 2014

2 INTEGRATION OF BIOGAS TECHNOLOGY INTO POWER GENERATION IN SRI LANKA H.A.S.C. Wijenayake (118364P) Thesis/ Dissertation submitted in partial fulfillment of the requirements for the Degree Master of Science Department of Mechanical Engineering University of Moratuwa Sri Lanka September 2014

3 DECLARATION I declare that this is my own work and this thesis/ dissertation does not incorporate without acknowledgement any material previously submitted for a Degree or Diploma in any other university or institute of higher learning and to the best of my knowledge and belief it does not contain any material previously published or written by another person except where the acknowledgement is made in the text. Also, I hereby grant to University of Moratuwa the non-exclusive right to reproduce and distribute my thesis/ dissertation, in whole or in part in print, electronic or other medium. I retain the right to use this content in whole or part in future works (Such as articles or books). Signature: Date: The above candidate has carried out research for the masters Dissertation under my supervision. Signature: Date: I

4 ABSTRACT The integration of biogas technology into power generation system in Sri Lanka, is studied and analysed, as a possible solution to raising problematic situation in Colombo city from generating MSW. To fulfill this requirement, present energy scenario in Sri Lanka, literature review and global development of biogas to power, case studies related to biogas technology, data collection of MSW to estimate the potential of biogas from OFMSW in Colombo city, analysis of data, developing a plan for a biogas power plant and evaluation of the proposed plant, are discussed. It is investigated and identified the biogas potential from OFMSW generating in Colombo city and electricity potential from produced biogas. It is synthesized to select the suitable digester technology and conversion technology to generate electricity from OFMSW, to continue the study. Further it is calculated and compared the key financial indexes such as NPV, IRR and payback period for the selected scenario, for several cases, to find out the financial viability of the proposed power project as well as evaluated the project under several aspects, to conclude the objective of this study. Further, it is revealed that the integration of biogas technology into power generation system is financially viable for all cases. II

5 DEDICATION I dedicate my thesis work to my family and many friends. A special feeling of gratitude to my loving parents, H.A.A. Wijenayake and M. Kusumawathi whose words of encouragement and push for tenacity ring in my ears. My wife G. Kumari Wijenayake has never left my side and is very special. I dedicate this work and give special thank to my wife, G. Kumari Wijenayake for being helping there for me throughout the entire master programme. I also dedicate this thesis to my many friends who have supported me throughout the process. I will always appreciate all they have carried out on behalf of me. III

6 ACKNOWLEDGEMENT This research project was successfully completed due to the guidance of my project supervisor. I would like to sincerely thank Professor Ajith de Alwis, supervisor of this research project, professor of Chemical and Process Engineering, University of Moratuwa, for his valuable time and patience. It is for his guidance, supervision & encouragement, this project became a reality. I would also like to thank Professor R.A. Attalage, Professor K.K.C.K. Perera and Dr. A.G.T. Sugathapala, senior lectureres of the Department of Mechanical Engineering, UOM, for their support and instructions at the initial stage of this research project. I would like to thank Dr. H.K.G. Punchihewa, course coordinator of MEng. Programme (2011/2012), and Dr. M.M.I.D Manthilake, senior lecturer of Department of Mechanical Engineering, for allocating their valuable time and for providing information required for this study. I wish to thank all engineers in Generation Planning and Design unit of CEB, for sharing their knowledge & experience on LTGEP. I express my deepest gratitude to manager, Online Knowledge Services, Mrs. Chandrika Kularathna of Practical Action, Colombo 5, for her support, encouragement & sharing knowledge and experience on biogas power plants. I also express my gratitude to DGM Asset Management Thermal Mechanical Eng. Lalith De Silva of CEB Asset Management Branch, for giving me the opportunity to follow this MEng Energy technology course. I sincerely thank my colleagues at Samanalawewa Power Station, CEB for their support to compile this research thesis. Finally I greatly appreciate & thank all my family members, all members in the staff of Samanalawewa Power Station, CEB, all staff members who engaged in MEng. Energy Technology Programme 2011/2012, university of Moratuwa & all members of MEng. Energy Technology batch 2011/2012 for helping me in numerous ways in different stages of this study. IV

7 TABLE OF CONTENTS Declaration of the candidate & supervisor i Abstract ii Dedication iii Acknowledgement iv Table of content v List of Figures viii List of Tables ix List of abbreviations x List of appendices xii 1. Introduction Background Supply of Energy Generation of Electricity Consumption of Electricity Problem Identification Goal Objectives Methodology Literature Review Background Microbiology & Biochemistry of Anaerobic Digestion Hydrolysis Acedogenesis Acetogenesis Methanogesis Factors Affect to Biogas Production Composition and Characteristics of Biogas General Information on Biogas Biogas Digester Technology Batch Type Digesters 32 V

8 Continuous Type Digesters Biogas to Power Conversion Technology Internal Combustion Engines Gas Turbines Combine Heat and Power Fuel Cells Summary Global Development of Biogas to Power Case Studies Community Biogas Plant at Fateh Singh-Ka-Purwa Community Biogas Plant at Jainpur Community Biogas Plant at the KCP Sugar Factory, Vuyyuru Community Biogas Plant at Bidhlam, Sonepat Data Collection and Analysis Data of MSW Biogas Potential from MSW in Colombo Power Production Fertilizer Production Green House Gas Emission Analysis of Data Assumptions Financial Analysis Analysis of Scenario Sensitivity Analysis Summary of Analysis Developing a Plan for Biogas Power Plant Setting up a Biogas Plant Project Schematic Diagram of a Biogas Power Plant Evaluation Economic Aspect Electricity Fertilizer 83 VI

9 6.2. Social Aspect Environmental Aspect Financing of Biogas Project Economic Forecast of a Biogas Power Plant Discussion and Conclusion Discussion Conclusion 90 Reference List 92 Appendices 95 Appendix 1: MSW Data 95 Appendix 2: General Details of the Plant 97 Appendix 3-6: Case Studies 98 Appendix 7-14: Sensitivity Analysis of Case Studies 106 VII

10 LIST OF FIGURES Page Figure 1.1 Evolution of Energy Supply Forms 3 Figure 1.2 Variations of Percentage Shares of the Primary Energy Supply 3 Figure 1.3 Gross Generation to CEB Grid 5 Figure 1.4 Evolution of Generation mix 5 Figure 1.5 Gross Generation of Renewable Energy Power Plants 6 Figure 1.6 Electricity Sales by Consumer Category 8 Figure 1.7 Total Energy Demand by Sector 9 Figure 1.8 Evolution of Total Energy Demand by Sectors 9 Figure 1.9 Energy Balance in Figure 2.1 Degradation Steps of Anaerobic Digestion Process 14 Figure 2.2 Schematic Representation of the Individual Microorganisms 16 Figure 2.3 Efficiencies of Biogas in Various Equipments 20 Figure 2.4 Schematic Diagram of Batch type Digester 33 Figure 2.5 Schematic Diagram of Vertical type Digesters 35 Figure 2.6 Schematic Diagram of Plug Flow Digester 37 Figure 2.7 Expansion of Biogas Fuelled Power Plants in Germany 48 Figure 2.8 Expansion of Biogas Power Plants in Poland 50 Figure 5.1 Schematic Diagram of a Power Generating System 82 Figure 7.1 A comparison between 3 Tier Tariff & Cost 89 VIII

11 LIST OF TABLES Page Table 1.1 Primary Energy Supply by Source 2 Table 1.2 Gross Generation to the CEB grid 4 Table 1.3 Total Gross Generation in Sri Lanka 6 Table 1.4 Electricity Sales by End Use Category 7 Table 1.5 Total Energy Demand by Sector 8 Table 2.1 Factors affect biogas production 18 Table 2.2 Chemical Composition of Biogas 19 Table 2.3 General Information of Biogas 20 Table 2.4 Energy Equivalent of Biogas 21 Table 2.5 Guide Values for Gas Consumption in Household Use 21 Table 2.6 Raw Materials Suitable for Biomethanation 22 Table 2.7 Biodegradability of Some Substrates 23 Table 2.8 Biogas Generation Rates of Some Substrates 24 Table 2.9 Gas Generation Guide Values 25 Table 2.10 Biogas Yields of Organic Matters 28 Table 2.11 C/N Ratios of Some Substrates 30 Table 2.12 Fuel Comparison Values 31 Table 2.13 Digester Types 34 Table 2.14 Comparison of Main Generator Options 45 Table 2.15 Typical Costs of Installing a Generation System use Biogas 46 Table 2.16 Air Emissions for Typical Generator Systems use Biogas 46 Table 2.17 Typical Noise Levels for Generator systems use Biogas 46 Table 3.1 Cost Benefits Analysis of Plant at Fateh-Singh-Ka-Purwa 65 Table 4.1 District-wise MSW Quantities 69 Table 4.2 Parameters Used as Input to Predict the Amount of Biogas 70 Table 4.3 Parameters Used as Input to Predict the Power Generation 71 Table 4.4 Fertilizer Production 72 Table 4.5 GHG Emission from Power Production from Biogas 72 Table 4.6 GHG Avoided by Using Biogas for Power Generation 73 IX

12 LIST OF ABBREVIATIONS AAS AD BOD BWEP CCY CCHP CEB CG CHP CISIR COD CO x DE DER DHW DOC DSM EPA ESDP ESMAP FIT GDP GEMIS GIS GOSL GTZ GWh IAEA IC IGEN Advanced Animal Science Co. Ltd Anaerobic Digestion Biological Oxygen Demand Boland Waste Energy Project Combined Cycle Power Plant Combined Cooling Heat & Power Ceylon Electricity Board Centralised Generation Combined Heat and Power Ceylon Institute of Scientific and Industrial Research Chemical Oxygen Demand Carbon Monoxide/Dioxide Distributed Energy Distributed Energy Resource Domestic Hot Water Degradable Organic Carbon Demand Side Management Environmental Protection Agency Energy Service Delivery Project Energy Sector Management Assistant Programme Feed In Tariff Gross Domestic Product Global Emission Model for Integrated Systems Geographic Information Software Government of Sri Lanka German Agency for Technical Corporation Giga watt hours International Atomic Energy Agency Internal Combustion Indo German Energy Program X

13 LNG LOLP MCFC MSW OFMSW MT MW NNFC NCRE NO x NORAD NRE NREL ORC OTEC O&M PDP PEMFC PPP PSDA PUCSL RERED SOFC SO x SPM SS T&D UNEP UNIDO VS Liquid Nitrogen Gas Loss of Load Probability Molten Carbonate Fuel Cell Municipal Solid Waste Organic Fraction of Municipal Solid Waste Metric Tone Mega watt National Non Food Crop Centre (UK) Non Conventional Renewable Energy Nitrogen Oxide/Dioxide Royal Norwegian Embassy Non-conventional Renewable Energy National Renewable Energy Laboratory Organic Rankine Cycle Ocean Thermal Energy Conversion Operation & Maintenance Project Development Programme Proton Exchange Membrane Fuel Cell Public Private Partnership Private Sector Development in Agriculture Public Utility Commission of Sri Lanka Renewable Energy Rural Economic Development Solid Oxide Fuel Cell Sulphur Oxides Suspended Particulate Matter Suspended Solids Transmission & Distribution United Nations Environment Programe United Nations Industrial Development Organization Volatile Solids XI

14 LIST OF APPENDICES Appendix 1 MSW Data 95 Appendix 2 General Details of the Plant 97 Appendix 3-6 Four Cases 98 Appendix 7-14 Sensitivity Analysis of Cases 1 to XII