Lalit Kumar Singh, PhD, FWRA was educated at Harcourt Butler Technological Institute in Kanpur, India and received his doctorate from the Indian Institute of Technology in Roorkee. He has more than 18 years of teaching and research experience. He researched fractionation of lignocellulosic biomass to extract soluble sugars and developed a novel sequential-co-culture technique for the efficient bioconversion of sugar to bioethanol and important innovation in the field of biofuels and fermentation technology. He has more than 70 publications in international journals, conference proceedings, chapters in books and edited and authored books. Gaurav Chaudhary, PhD, has more than seven years of experience of teaching and research in the field of bioenergy and biochemical engineering. He is currently an assistant professor in the Department of Renewable and Bio-Energy Engineering at the College of Agricultural Engineering and Technology. He received his PhD from the Indian Institute of Technology in Roorkee in the field of biofuel and bioenergy. He has published many research articles in peer-reviewed scientific journals and presented his research work at conferences in these areas. The areas of research he is involved with currently are lignin fractionation and its valorization, bioenergy, and other value-added products.

• Preface xv1 Biogas, Biomethane and BioCNG: Definitions, Technologies and Solutions 1Alessandra Lee Barbosa Firmo, Fabrícia Maria Santana Silva, Ingrid Roberta de F.S. Alves, Ericka Patrícia Lima de Brito and Leandro Cesar Santos da Silva1.1 Definitions and Sources of Production of Biogas, Biomethane and BioCNG 21.2 Production Chains, Utilization and Valorization of Biogas 51.2.1 Anaerobic Digesters 81.2.1.1 Techniques for Optimization of Anaerobic Digestion 121.2.1.2 Biogas Recovery Plants 141.2.1.3 Biofertilizers – Material Valorization 151.2.2 Landfills: Final Disposal and Biogasvalorization 161.3 Uses of Biomethane: Practice Examples 201.4 Challenges and Opportunities 21References 252 Biomethanisation: Biogas Production Technologies 33Gabor Z. Szelenyi2.1 Relevance 342.2 Oxidation without Oxygen – Anaerobic Biodegradation of the Organic Matter 352.3 Bifurcating Metabolic Pathways 352.4 Methanogenesis 372.5 Imitation of Nature – Improvement through Controlled Environment 402.6 Operational Challenges 442.7 Post-Treatment 472.8 Outlook – Fields of Further Research and Technological Development 492.9 Conclusion – Development Goals 55Acknowledgments 60References 603 Effect of Process Parameters on Biogas Yield: A Systematic Review 65H.O. Omoregbee, M. O. Okwu, L.K. Tartibu, A.E. Ivbanikaro, M.U. Olanipekun and A.B. Edward3.1 Introduction 663.2 Effect of Process Parameters on Biogas Yield 673.2.1 Temperature Effect on Biogas Yield 673.2.2 Effect of pH on Biogas Yield 693.2.3 Effect of Hydraulic Retention Time (HRT) on Biogas Yield 703.2.4 Effect of Agitation or Stirring on Biogas Yield 713.3 Pre-Treatment Process 723.3.1 Mechanical Treatment 733.3.2 Microwave Irradiation 733.3.3 Thermal Pre-Treatment Process 733.3.4 Chemical Treatment 743.3.4.1 Acid 743.3.4.2 Alkali 743.3.5 Biological Treatment 753.3.6 Biochemical Methane Potential 763.4 Effect of Co-Digestion of Two or More Substrates 763.5 Effect of Total Solid ContenT (TSC) 783.5.1 Acidogenesis 793.5.2 Hydrolysis 793.5.3 Methanogenesis 803.5.4 Acetogenesis 803.6 Addressing AD Bottlenecks Caused by the Physicochemical Properties of Substrate 803.6.1 Carbon Dioxide Removal Technologies for Upgrading Biogas 813.7 Conclusion 83References 844 Biogas for Electricity Generation in Nigeria: A Systematic Review of the Prospects, Efforts and Contemporary Challenges 91Victor M. Mbachu, Modestus O. Okwu, Celine C. Chiabuotu and Lagouge K. Tartibu4.1 Introduction 924.2 Bioenergy and Biogas Technology 934.3 Chronicle of Research Efforts in Biogas Technology 944.3.1 Assessment of Biomass Potential for Biogas and Electricity Generation 944.3.2 Use of Co-Digestion for Enhanced Production 954.3.3 Enhancement of Biogas Production Using Pre-Treatment of Feedstock 964.3.4 Inoculation of Substrate for Biogas Production 964.3.5 Optimization of Biogas Production Process Parameters 974.3.6 Digester Design 974.3.7 Upgrading and Purification of Biogas 984.3.8 Modeling of Biogas Production 994.4 Current Research and Developmental Trend in Biogas Technology 1004.5 Conclusion 101References 1015 Biohydrogen Production Technologies: Current Status, Challenges, and Future Perspectives 115Akanksha Jain, Eeshita Das, Venkata Giridhar Poosarla and Gobinath Rajagopalan5.1 Introduction 1165.2 Hydrogen vs. Biohydrogen 1165.3 Biohydrogen from Light Dependent Processes 1195.3.1 Photo-Fermentation (PF) 1195.3.1.1 Biocatalysts Involved in PF 1205.3.1.2 General Mechanism of Biohydrogen Production from PF 1235.3.1.3 Current Status of PF 1245.3.1.4 Major Factors that Influence the PF Process 1245.3.1.5 Challenges Reported 1345.3.2 Biophotolysis (BP) 1345.3.2.1 General Mechanism of Hydrogen Production from Biophotolysis 1365.3.2.2 Current Status of BP 1365.3.2.3 Major Factors Influence BP 1375.3.2.4 Challenges Reported 1415.4 Biohydrogen Production from Dark Fermentation 1415.4.1 Dark Fermentation (DF) 1415.4.2 Biocatalysts Involved in DF 1435.4.2.1 Formate Lyase Complex 1445.4.3 General Mechanism and Biochemistry of Biohydrogen Production from DF 1445.4.3.1 Clostridia 1445.4.3.2 Non-Clostridia 1465.4.4 Current Status 1465.4.4.1 Feedstock 1465.4.4.2 Process Design 1485.4.4.3 Factors Influencing DF 1505.4.4.4 DF by Mixed Consortia 1525.4.4.5 Biohydrogen Production by Using Pure Culture 1545.4.5 Challenges Reported 1545.5 Other Methods of Biohydrogen Production 1545.5.1 Bioelectrolysis 1545.6 Future Perspectives of Biohydrogen Production 157Acknowledgment 158References 1586 Biomass Gasification, Some Theory, and Practical Examples 169Eduardo C. M. Loureiro, Isabella A. Garrett, Clériston Vieira Junior and Sérgio Peres6.1 Introduction 1706.2 Fixed-Bed Reactors 1716.3 Fluidized-Bed Reactors 1736.4 Biomass Characterization 1756.5 Production of Syngas from Wood in a Downdraft Fixed Bed 1766.5.1 Methodology 1766.5.2 Results 1836.6 Construction and Hydrodynamic Characterization of a Bubbling Fluidized-Bed Gasifier 1846.6.1 Introduction 1846.6.2 Methodology 1856.6.2.1 Bed Characterization 1856.6.2.2 Cold Flow Model – CFM 1866.6.2.3 Experimental Vmf 1876.6.2.4 Theoretical Vmf 1896.6.3 Results and Discussions 1906.6.3.1 Velocity of Minimal Fluidization - Vmf 1916.6.3.2 Gasifier Construction 2006.6.3.3 Gasification Experiments 201References 2047 Experimental Investigation on Producer Gas Generation Through Briquettes Using Agricultural Wastes 207Senthil Ramlingam, Balamurugan Rajendiran,Thendral T. and Sudagar S.7.1 Introduction 2087.2 Materials for Present Work 2107.2.1 Feedstock 2107.2.1.1 Sesame Plant 2107.2.1.2 Maize Cob (MC) 2117.2.2 Binder Material 2117.2.3 Briquette Preparation 2127.2.4 Physical Properties of Briquette 2137.2.4.1 Proximate Analysis 2137.2.4.2 Bulk Density 2157.2.5 Ultimate Analysis 2157.2.6 Calorific Value of Feedstock 2157.2.7 Mechanical Properties of Briquette 2167.2.7.1 Compressive Strength 2167.2.7.2 Shatter Index 2167.3 Result and Discussion 2167.3.1 Proximate Analysis 2177.3.1.1 Ash 2177.3.1.2 Moisture 2177.3.1.3 Fixed Carbon 2177.3.1.4 Volatile Matter 2187.3.2 Ultimate Analysis 2187.3.3 Density 2197.3.4 Compressive Strength of Briquette 2197.3.5 Calorific Value 2207.3.6 Comparative Analysis of Properties 2217.4 Generation of Producer Gas 2227.4.1 Effect of Temperature on Producer Gas 2237.5 Producer Gas Suitability in Engines 2247.6 Conclusion 224Bibliography 2258 Biomass Gasification for Distributed Generation and Biochar Production: An Application to the Olive Oil Supply Chain 229Roque Aguado, Antonio Escámez, David Vera, Dolores Eliche-Quesada and Luis Pérez-Villarejo8.1 Introduction 2308.1.1 By-Products of the Olive Oil Industry 2308.1.2 Gasification for Distributed Generation 2328.1.3 Gasification for Biochar Production 2368.2 Methodology 2378.2.1 Description of the Experimental Gasification Plant 2378.2.2 Physicochemical Properties of the By-Products from the Olive Oil Industry 2398.2.3 Experimental Procedure 2438.2.4 Biochar Physicochemical Characterization 2458.3 Results 2458.3.1 Assembly and Installation of the Gasification Plant 2458.3.2 Experimental Results 2468.3.3 Biochar Characterization and Potential for the Olive Oil Industry 2508.4 Economic Impact of Gasification in the Olive Oil Industry 2528.5 Conclusions 256Acknowledgements 257References 2589 Conversion of Agro Wastes to Solid and Gaseous Biofuels through Thermal Cracking Technique 263Senthil Ramlingam, Sudagar Subramanian and Pranesh Ganesan9.1 Introduction 2649.1.2 Energy Resources 2649.2 Biomass 2669.3 Biomass Energy Conversion Technologies 2679.3.1 Thermal Cracking Process 2689.3.1.1 Gasification 2689.3.1.2 Pyrolysis Process 2689.4 Types of Pyrolysis Process 2699.4.1 Conventional or Slow Pyrolysis 2699.4.2 Fast Pyrolysis 2709.4.3 Flash Pyrolysis 2709.5 Mechanism Involved During Pyrolysis 2709.5.1 Mechanism in Hemicelluloses 2709.5.2 Mechanism in Cellulose 2729.5.3 Mechanism in Lignin 2729.6 Pyrolysis Products 2729.6.1 Bio-Oil 2739.6.2 Residue 2739.6.3 Syngas 2749.7 Present Investigation 2749.7.1 Materials and Methods 2759.7.1.1 Cashew Nut Shell 2759.7.1.2 Sawdust 2759.7.1.3 Sugarcane Bagasse 2769.7.1.4 Binder 2779.7.2 Preparation of Briquetting 2789.7.3 Sources for Briquetting 2789.8 Methodology 2789.8.1 Bio-Oil Extraction Process 2819.9 Result and Discussion 2819.9.1 Analysis of Briquette 2819.9.2 Thermo Gravimetric Analysis 2829.9.3 Products of Pyrolysis Process 2839.9.4 Fuel Properties 2849.9.4.1 FTIR 2849.9.4.2 Biochar and Syngas Analysis 2859.9.4.3 Biochar 2859.9.4.4 Syngas 2869.10 Conclusion 286Bibliography 28710 Insights Into the Production of Biochar from Organic Waste 291Jaskiran Kaur and Gaurav Chaudhary10.1 Introduction 29210.2 Organic Waste as Feedstocks for Biochar Production 29310.3 Thermochemical Conversion of Organic Waste into Biochar 29410.4 Factors Affecting Biochar Yield and Properties 29510.4.1 Feedstock Type and Composition 29510.4.2 Pyrolysis Temperature 29610.5 Utilization of Biochar 31010.5.1 As a Soil Amendment 31010.5.2 Carbon Sequestration 31010.5.3 Remediation of Pollutants from Soil 31110.5.4 Water and Wastewater Treatment 31110.6 Conclusion 312References 31311 Thermo-Economic Study of öNORM M7 133 Chips in a Pilot Scale Reactor 321Alok Dhaundiya and Divine AtsuNotation 32111.1 Introduction 32211.2 Material and Methods 32411.2.1 Installation of the Experimental Unit 32411.2.2 Physical Exergy of the System 32711.2.3 Sinking Fund Method 32911.3 Results and Discussion 33111.3.1 Exergy Analysis 33111.3.2 Valuation of Pyrolysis Unit 33711.4 Conclusion 338References 33812 Production and Characterization of Briquettes Produced from Blend of Rice Husk and Water-Hyacinth 341Modestus O. Okwu, Omonigho B. Otanocha, Olusegun D. Samuel and E. E. Akporhonor12.1 Background of the Study 34212.2 Review of Literature 34312.2.1 Renewable Energy Demand 34312.2.2 Briquette Production 34412.2.3 Feedstock for Briquette Production 34412.2.4 Proximate Analysis of Briquettes 34512.3 Materials and Method 34512.3.1 Material Processing, Measurement and Blending 34512.3.2 Proximate Analysis of Sample Materials 34612.3.3 Moisture Content MC (%) 34712.3.4 Ash Content AC (%) 34712.3.5 Volatile Matter (VM) Content 34812.3.6 Fixed Carbon Content FC (%) 34812.3.7 Calorific Value 34812.4 Results and Analysis 34912.4.1 Moisture Content 34912.4.2 Volatile Matter Content 34912.4.3 Ash Content 35012.4.4 Fixed Carbon Content 35012.5 Discussion 35112.6 Conclusion 352Acknowledgement 352References 35213 Torrefaction and Pelletization of Lignocellulosic Biomass for Energy Intensified Fuel Substitute 357Chitra Devi Venkatachalam, Mothil Sengottian and Sathish Raam Ravichandran13.1 Introduction – Biomass as Fuel 35813.2 Torrefaction 35913.2.1 Reaction Mechanism 35913.2.2 Characterization of Torrefied Biomass 36013.2.2.1 Moisture Content 36013.2.2.2 Bulk Density 36013.2.2.3 Grindability 36113.2.2.4 High Heating Value 36113.2.2.5 Mass Yield, Energy Yield and Enhancement Factor 36213.2.2.6 Particle Size Distribution 36313.2.3 Reactors for Torrefaction 36413.2.3.1 Fixed Bed Reactor 36413.2.3.2 Moving Bed Reactor 36413.2.3.3 Entrained Flow Reactor 36413.2.3.4 Fluidized Bed Reactor 36413.2.3.5 Rotary Drum Reactor 36513.2.3.6 Microwave Reactor 36513.2.3.7 Hydrothermal Reactor 36513.3. Pelletization 36513.3.1 Pelletization of Torrefied Biomass 36513.3.2 Types of Pelletizers 36713.3.2.1 Flat Die Pellet Mill 36713.3.2.2 Round Die Pellet Mill 36713.3.3 Influence of Process Parameters during the Pelletization 36813.3.3.1 Moisture Content 36813.3.3.2 Pelletization Temperature 36813.3.3.3 Particle Size 36813.3.3.4 Press Channel Dimensions 36813.3.3.5 Pelletization Pressure 36813.3.3.6 Torrefaction Temperature 36913.4 Application of Torrefaction Process 36913.4.1 Using Torrefaction as Pre-Treatment Step for Biomass Gasification 36913.4.2 Blending Torrefied Biomass with Coal and Co-Firing for Energy Production 36913.4.3 Fuel for Steel Making in Blast Furnace 37013.5 Conclusion 370References 370Index 375

Lalit Kumar Singh, PhD, FWRA was educated at Harcourt Butler Technological Institute in Kanpur, India and received his doctorate from the Indian Institute of Technology in Roorkee. He has more than 18 years of teaching and research experience. He researched fractionation of lignocellulosic biomass to extract soluble sugars and developed a novel sequential-co-culture technique for the efficient bioconversion of sugar to bioethanol and important innovation in the field of biofuels and fermentation technology. He has more than 70 publications in international journals, conference proceedings, chapters in books and edited and authored books. Gaurav Chaudhary, PhD, has more than seven years of experience of teaching and research in the field of bioenergy and biochemical engineering. He is currently an assistant professor in the Department of Renewable and Bio-Energy Engineering at the College of Agricultural Engineering and Technology. He received his PhD from the Indian Institute of Technology in Roorkee in the field of biofuel and bioenergy. He has published many research articles in peer-reviewed scientific journals and presented his research work at conferences in these areas. The areas of research he is involved with currently are lignin fractionation and its valorization, bioenergy, and other value-added products.

• Preface xv1 Biogas, Biomethane and BioCNG: Definitions, Technologies and Solutions 1Alessandra Lee Barbosa Firmo, Fabrícia Maria Santana Silva, Ingrid Roberta de F.S. Alves, Ericka Patrícia Lima de Brito and Leandro Cesar Santos da Silva1.1 Definitions and Sources of Production of Biogas, Biomethane and BioCNG 21.2 Production Chains, Utilization and Valorization of Biogas 51.2.1 Anaerobic Digesters 81.2.1.1 Techniques for Optimization of Anaerobic Digestion 121.2.1.2 Biogas Recovery Plants 141.2.1.3 Biofertilizers – Material Valorization 151.2.2 Landfills: Final Disposal and Biogasvalorization 161.3 Uses of Biomethane: Practice Examples 201.4 Challenges and Opportunities 21References 252 Biomethanisation: Biogas Production Technologies 33Gabor Z. Szelenyi2.1 Relevance 342.2 Oxidation without Oxygen – Anaerobic Biodegradation of the Organic Matter 352.3 Bifurcating Metabolic Pathways 352.4 Methanogenesis 372.5 Imitation of Nature – Improvement through Controlled Environment 402.6 Operational Challenges 442.7 Post-Treatment 472.8 Outlook – Fields of Further Research and Technological Development 492.9 Conclusion – Development Goals 55Acknowledgments 60References 603 Effect of Process Parameters on Biogas Yield: A Systematic Review 65H.O. Omoregbee, M. O. Okwu, L.K. Tartibu, A.E. Ivbanikaro, M.U. Olanipekun and A.B. Edward3.1 Introduction 663.2 Effect of Process Parameters on Biogas Yield 673.2.1 Temperature Effect on Biogas Yield 673.2.2 Effect of pH on Biogas Yield 693.2.3 Effect of Hydraulic Retention Time (HRT) on Biogas Yield 703.2.4 Effect of Agitation or Stirring on Biogas Yield 713.3 Pre-Treatment Process 723.3.1 Mechanical Treatment 733.3.2 Microwave Irradiation 733.3.3 Thermal Pre-Treatment Process 733.3.4 Chemical Treatment 743.3.4.1 Acid 743.3.4.2 Alkali 743.3.5 Biological Treatment 753.3.6 Biochemical Methane Potential 763.4 Effect of Co-Digestion of Two or More Substrates 763.5 Effect of Total Solid ContenT (TSC) 783.5.1 Acidogenesis 793.5.2 Hydrolysis 793.5.3 Methanogenesis 803.5.4 Acetogenesis 803.6 Addressing AD Bottlenecks Caused by the Physicochemical Properties of Substrate 803.6.1 Carbon Dioxide Removal Technologies for Upgrading Biogas 813.7 Conclusion 83References 844 Biogas for Electricity Generation in Nigeria: A Systematic Review of the Prospects, Efforts and Contemporary Challenges 91Victor M. Mbachu, Modestus O. Okwu, Celine C. Chiabuotu and Lagouge K. Tartibu4.1 Introduction 924.2 Bioenergy and Biogas Technology 934.3 Chronicle of Research Efforts in Biogas Technology 944.3.1 Assessment of Biomass Potential for Biogas and Electricity Generation 944.3.2 Use of Co-Digestion for Enhanced Production 954.3.3 Enhancement of Biogas Production Using Pre-Treatment of Feedstock 964.3.4 Inoculation of Substrate for Biogas Production 964.3.5 Optimization of Biogas Production Process Parameters 974.3.6 Digester Design 974.3.7 Upgrading and Purification of Biogas 984.3.8 Modeling of Biogas Production 994.4 Current Research and Developmental Trend in Biogas Technology 1004.5 Conclusion 101References 1015 Biohydrogen Production Technologies: Current Status, Challenges, and Future Perspectives 115Akanksha Jain, Eeshita Das, Venkata Giridhar Poosarla and Gobinath Rajagopalan5.1 Introduction 1165.2 Hydrogen vs. Biohydrogen 1165.3 Biohydrogen from Light Dependent Processes 1195.3.1 Photo-Fermentation (PF) 1195.3.1.1 Biocatalysts Involved in PF 1205.3.1.2 General Mechanism of Biohydrogen Production from PF 1235.3.1.3 Current Status of PF 1245.3.1.4 Major Factors that Influence the PF Process 1245.3.1.5 Challenges Reported 1345.3.2 Biophotolysis (BP) 1345.3.2.1 General Mechanism of Hydrogen Production from Biophotolysis 1365.3.2.2 Current Status of BP 1365.3.2.3 Major Factors Influence BP 1375.3.2.4 Challenges Reported 1415.4 Biohydrogen Production from Dark Fermentation 1415.4.1 Dark Fermentation (DF) 1415.4.2 Biocatalysts Involved in DF 1435.4.2.1 Formate Lyase Complex 1445.4.3 General Mechanism and Biochemistry of Biohydrogen Production from DF 1445.4.3.1 Clostridia 1445.4.3.2 Non-Clostridia 1465.4.4 Current Status 1465.4.4.1 Feedstock 1465.4.4.2 Process Design 1485.4.4.3 Factors Influencing DF 1505.4.4.4 DF by Mixed Consortia 1525.4.4.5 Biohydrogen Production by Using Pure Culture 1545.4.5 Challenges Reported 1545.5 Other Methods of Biohydrogen Production 1545.5.1 Bioelectrolysis 1545.6 Future Perspectives of Biohydrogen Production 157Acknowledgment 158References 1586 Biomass Gasification, Some Theory, and Practical Examples 169Eduardo C. M. Loureiro, Isabella A. Garrett, Clériston Vieira Junior and Sérgio Peres6.1 Introduction 1706.2 Fixed-Bed Reactors 1716.3 Fluidized-Bed Reactors 1736.4 Biomass Characterization 1756.5 Production of Syngas from Wood in a Downdraft Fixed Bed 1766.5.1 Methodology 1766.5.2 Results 1836.6 Construction and Hydrodynamic Characterization of a Bubbling Fluidized-Bed Gasifier 1846.6.1 Introduction 1846.6.2 Methodology 1856.6.2.1 Bed Characterization 1856.6.2.2 Cold Flow Model – CFM 1866.6.2.3 Experimental Vmf 1876.6.2.4 Theoretical Vmf 1896.6.3 Results and Discussions 1906.6.3.1 Velocity of Minimal Fluidization - Vmf 1916.6.3.2 Gasifier Construction 2006.6.3.3 Gasification Experiments 201References 2047 Experimental Investigation on Producer Gas Generation Through Briquettes Using Agricultural Wastes 207Senthil Ramlingam, Balamurugan Rajendiran,Thendral T. and Sudagar S.7.1 Introduction 2087.2 Materials for Present Work 2107.2.1 Feedstock 2107.2.1.1 Sesame Plant 2107.2.1.2 Maize Cob (MC) 2117.2.2 Binder Material 2117.2.3 Briquette Preparation 2127.2.4 Physical Properties of Briquette 2137.2.4.1 Proximate Analysis 2137.2.4.2 Bulk Density 2157.2.5 Ultimate Analysis 2157.2.6 Calorific Value of Feedstock 2157.2.7 Mechanical Properties of Briquette 2167.2.7.1 Compressive Strength 2167.2.7.2 Shatter Index 2167.3 Result and Discussion 2167.3.1 Proximate Analysis 2177.3.1.1 Ash 2177.3.1.2 Moisture 2177.3.1.3 Fixed Carbon 2177.3.1.4 Volatile Matter 2187.3.2 Ultimate Analysis 2187.3.3 Density 2197.3.4 Compressive Strength of Briquette 2197.3.5 Calorific Value 2207.3.6 Comparative Analysis of Properties 2217.4 Generation of Producer Gas 2227.4.1 Effect of Temperature on Producer Gas 2237.5 Producer Gas Suitability in Engines 2247.6 Conclusion 224Bibliography 2258 Biomass Gasification for Distributed Generation and Biochar Production: An Application to the Olive Oil Supply Chain 229Roque Aguado, Antonio Escámez, David Vera, Dolores Eliche-Quesada and Luis Pérez-Villarejo8.1 Introduction 2308.1.1 By-Products of the Olive Oil Industry 2308.1.2 Gasification for Distributed Generation 2328.1.3 Gasification for Biochar Production 2368.2 Methodology 2378.2.1 Description of the Experimental Gasification Plant 2378.2.2 Physicochemical Properties of the By-Products from the Olive Oil Industry 2398.2.3 Experimental Procedure 2438.2.4 Biochar Physicochemical Characterization 2458.3 Results 2458.3.1 Assembly and Installation of the Gasification Plant 2458.3.2 Experimental Results 2468.3.3 Biochar Characterization and Potential for the Olive Oil Industry 2508.4 Economic Impact of Gasification in the Olive Oil Industry 2528.5 Conclusions 256Acknowledgements 257References 2589 Conversion of Agro Wastes to Solid and Gaseous Biofuels through Thermal Cracking Technique 263Senthil Ramlingam, Sudagar Subramanian and Pranesh Ganesan9.1 Introduction 2649.1.2 Energy Resources 2649.2 Biomass 2669.3 Biomass Energy Conversion Technologies 2679.3.1 Thermal Cracking Process 2689.3.1.1 Gasification 2689.3.1.2 Pyrolysis Process 2689.4 Types of Pyrolysis Process 2699.4.1 Conventional or Slow Pyrolysis 2699.4.2 Fast Pyrolysis 2709.4.3 Flash Pyrolysis 2709.5 Mechanism Involved During Pyrolysis 2709.5.1 Mechanism in Hemicelluloses 2709.5.2 Mechanism in Cellulose 2729.5.3 Mechanism in Lignin 2729.6 Pyrolysis Products 2729.6.1 Bio-Oil 2739.6.2 Residue 2739.6.3 Syngas 2749.7 Present Investigation 2749.7.1 Materials and Methods 2759.7.1.1 Cashew Nut Shell 2759.7.1.2 Sawdust 2759.7.1.3 Sugarcane Bagasse 2769.7.1.4 Binder 2779.7.2 Preparation of Briquetting 2789.7.3 Sources for Briquetting 2789.8 Methodology 2789.8.1 Bio-Oil Extraction Process 2819.9 Result and Discussion 2819.9.1 Analysis of Briquette 2819.9.2 Thermo Gravimetric Analysis 2829.9.3 Products of Pyrolysis Process 2839.9.4 Fuel Properties 2849.9.4.1 FTIR 2849.9.4.2 Biochar and Syngas Analysis 2859.9.4.3 Biochar 2859.9.4.4 Syngas 2869.10 Conclusion 286Bibliography 28710 Insights Into the Production of Biochar from Organic Waste 291Jaskiran Kaur and Gaurav Chaudhary10.1 Introduction 29210.2 Organic Waste as Feedstocks for Biochar Production 29310.3 Thermochemical Conversion of Organic Waste into Biochar 29410.4 Factors Affecting Biochar Yield and Properties 29510.4.1 Feedstock Type and Composition 29510.4.2 Pyrolysis Temperature 29610.5 Utilization of Biochar 31010.5.1 As a Soil Amendment 31010.5.2 Carbon Sequestration 31010.5.3 Remediation of Pollutants from Soil 31110.5.4 Water and Wastewater Treatment 31110.6 Conclusion 312References 31311 Thermo-Economic Study of öNORM M7 133 Chips in a Pilot Scale Reactor 321Alok Dhaundiya and Divine AtsuNotation 32111.1 Introduction 32211.2 Material and Methods 32411.2.1 Installation of the Experimental Unit 32411.2.2 Physical Exergy of the System 32711.2.3 Sinking Fund Method 32911.3 Results and Discussion 33111.3.1 Exergy Analysis 33111.3.2 Valuation of Pyrolysis Unit 33711.4 Conclusion 338References 33812 Production and Characterization of Briquettes Produced from Blend of Rice Husk and Water-Hyacinth 341Modestus O. Okwu, Omonigho B. Otanocha, Olusegun D. Samuel and E. E. Akporhonor12.1 Background of the Study 34212.2 Review of Literature 34312.2.1 Renewable Energy Demand 34312.2.2 Briquette Production 34412.2.3 Feedstock for Briquette Production 34412.2.4 Proximate Analysis of Briquettes 34512.3 Materials and Method 34512.3.1 Material Processing, Measurement and Blending 34512.3.2 Proximate Analysis of Sample Materials 34612.3.3 Moisture Content MC (%) 34712.3.4 Ash Content AC (%) 34712.3.5 Volatile Matter (VM) Content 34812.3.6 Fixed Carbon Content FC (%) 34812.3.7 Calorific Value 34812.4 Results and Analysis 34912.4.1 Moisture Content 34912.4.2 Volatile Matter Content 34912.4.3 Ash Content 35012.4.4 Fixed Carbon Content 35012.5 Discussion 35112.6 Conclusion 352Acknowledgement 352References 35213 Torrefaction and Pelletization of Lignocellulosic Biomass for Energy Intensified Fuel Substitute 357Chitra Devi Venkatachalam, Mothil Sengottian and Sathish Raam Ravichandran13.1 Introduction – Biomass as Fuel 35813.2 Torrefaction 35913.2.1 Reaction Mechanism 35913.2.2 Characterization of Torrefied Biomass 36013.2.2.1 Moisture Content 36013.2.2.2 Bulk Density 36013.2.2.3 Grindability 36113.2.2.4 High Heating Value 36113.2.2.5 Mass Yield, Energy Yield and Enhancement Factor 36213.2.2.6 Particle Size Distribution 36313.2.3 Reactors for Torrefaction 36413.2.3.1 Fixed Bed Reactor 36413.2.3.2 Moving Bed Reactor 36413.2.3.3 Entrained Flow Reactor 36413.2.3.4 Fluidized Bed Reactor 36413.2.3.5 Rotary Drum Reactor 36513.2.3.6 Microwave Reactor 36513.2.3.7 Hydrothermal Reactor 36513.3. Pelletization 36513.3.1 Pelletization of Torrefied Biomass 36513.3.2 Types of Pelletizers 36713.3.2.1 Flat Die Pellet Mill 36713.3.2.2 Round Die Pellet Mill 36713.3.3 Influence of Process Parameters during the Pelletization 36813.3.3.1 Moisture Content 36813.3.3.2 Pelletization Temperature 36813.3.3.3 Particle Size 36813.3.3.4 Press Channel Dimensions 36813.3.3.5 Pelletization Pressure 36813.3.3.6 Torrefaction Temperature 36913.4 Application of Torrefaction Process 36913.4.1 Using Torrefaction as Pre-Treatment Step for Biomass Gasification 36913.4.2 Blending Torrefied Biomass with Coal and Co-Firing for Energy Production 36913.4.3 Fuel for Steel Making in Blast Furnace 37013.5 Conclusion 370References 370Index 375

Lalit Kumar Singh, PhD, FWRA was educated at Harcourt Butler Technological Institute in Kanpur, India and received his doctorate from the Indian Institute of Technology in Roorkee. He has more than 18 years of teaching and research experience. He researched fractionation of lignocellulosic biomass to extract soluble sugars and developed a novel sequential-co-culture technique for the efficient bioconversion of sugar to bioethanol and important innovation in the field of biofuels and fermentation technology. He has more than 70 publications in international journals, conference proceedings, chapters in books and edited and authored books. Gaurav Chaudhary, PhD, has more than seven years of experience of teaching and research in the field of bioenergy and biochemical engineering. He is currently an assistant professor in the Department of Renewable and Bio-Energy Engineering at the College of Agricultural Engineering and Technology. He received his PhD from the Indian Institute of Technology in Roorkee in the field of biofuel and bioenergy. He has published many research articles in peer-reviewed scientific journals and presented his research work at conferences in these areas. The areas of research he is involved with currently are lignin fractionation and its valorization, bioenergy, and other value-added products.

• Preface xv1 Biogas, Biomethane and BioCNG: Definitions, Technologies and Solutions 1Alessandra Lee Barbosa Firmo, Fabrícia Maria Santana Silva, Ingrid Roberta de F.S. Alves, Ericka Patrícia Lima de Brito and Leandro Cesar Santos da Silva1.1 Definitions and Sources of Production of Biogas, Biomethane and BioCNG 21.2 Production Chains, Utilization and Valorization of Biogas 51.2.1 Anaerobic Digesters 81.2.1.1 Techniques for Optimization of Anaerobic Digestion 121.2.1.2 Biogas Recovery Plants 141.2.1.3 Biofertilizers – Material Valorization 151.2.2 Landfills: Final Disposal and Biogasvalorization 161.3 Uses of Biomethane: Practice Examples 201.4 Challenges and Opportunities 21References 252 Biomethanisation: Biogas Production Technologies 33Gabor Z. Szelenyi2.1 Relevance 342.2 Oxidation without Oxygen – Anaerobic Biodegradation of the Organic Matter 352.3 Bifurcating Metabolic Pathways 352.4 Methanogenesis 372.5 Imitation of Nature – Improvement through Controlled Environment 402.6 Operational Challenges 442.7 Post-Treatment 472.8 Outlook – Fields of Further Research and Technological Development 492.9 Conclusion – Development Goals 55Acknowledgments 60References 603 Effect of Process Parameters on Biogas Yield: A Systematic Review 65H.O. Omoregbee, M. O. Okwu, L.K. Tartibu, A.E. Ivbanikaro, M.U. Olanipekun and A.B. Edward3.1 Introduction 663.2 Effect of Process Parameters on Biogas Yield 673.2.1 Temperature Effect on Biogas Yield 673.2.2 Effect of pH on Biogas Yield 693.2.3 Effect of Hydraulic Retention Time (HRT) on Biogas Yield 703.2.4 Effect of Agitation or Stirring on Biogas Yield 713.3 Pre-Treatment Process 723.3.1 Mechanical Treatment 733.3.2 Microwave Irradiation 733.3.3 Thermal Pre-Treatment Process 733.3.4 Chemical Treatment 743.3.4.1 Acid 743.3.4.2 Alkali 743.3.5 Biological Treatment 753.3.6 Biochemical Methane Potential 763.4 Effect of Co-Digestion of Two or More Substrates 763.5 Effect of Total Solid ContenT (TSC) 783.5.1 Acidogenesis 793.5.2 Hydrolysis 793.5.3 Methanogenesis 803.5.4 Acetogenesis 803.6 Addressing AD Bottlenecks Caused by the Physicochemical Properties of Substrate 803.6.1 Carbon Dioxide Removal Technologies for Upgrading Biogas 813.7 Conclusion 83References 844 Biogas for Electricity Generation in Nigeria: A Systematic Review of the Prospects, Efforts and Contemporary Challenges 91Victor M. Mbachu, Modestus O. Okwu, Celine C. Chiabuotu and Lagouge K. Tartibu4.1 Introduction 924.2 Bioenergy and Biogas Technology 934.3 Chronicle of Research Efforts in Biogas Technology 944.3.1 Assessment of Biomass Potential for Biogas and Electricity Generation 944.3.2 Use of Co-Digestion for Enhanced Production 954.3.3 Enhancement of Biogas Production Using Pre-Treatment of Feedstock 964.3.4 Inoculation of Substrate for Biogas Production 964.3.5 Optimization of Biogas Production Process Parameters 974.3.6 Digester Design 974.3.7 Upgrading and Purification of Biogas 984.3.8 Modeling of Biogas Production 994.4 Current Research and Developmental Trend in Biogas Technology 1004.5 Conclusion 101References 1015 Biohydrogen Production Technologies: Current Status, Challenges, and Future Perspectives 115Akanksha Jain, Eeshita Das, Venkata Giridhar Poosarla and Gobinath Rajagopalan5.1 Introduction 1165.2 Hydrogen vs. Biohydrogen 1165.3 Biohydrogen from Light Dependent Processes 1195.3.1 Photo-Fermentation (PF) 1195.3.1.1 Biocatalysts Involved in PF 1205.3.1.2 General Mechanism of Biohydrogen Production from PF 1235.3.1.3 Current Status of PF 1245.3.1.4 Major Factors that Influence the PF Process 1245.3.1.5 Challenges Reported 1345.3.2 Biophotolysis (BP) 1345.3.2.1 General Mechanism of Hydrogen Production from Biophotolysis 1365.3.2.2 Current Status of BP 1365.3.2.3 Major Factors Influence BP 1375.3.2.4 Challenges Reported 1415.4 Biohydrogen Production from Dark Fermentation 1415.4.1 Dark Fermentation (DF) 1415.4.2 Biocatalysts Involved in DF 1435.4.2.1 Formate Lyase Complex 1445.4.3 General Mechanism and Biochemistry of Biohydrogen Production from DF 1445.4.3.1 Clostridia 1445.4.3.2 Non-Clostridia 1465.4.4 Current Status 1465.4.4.1 Feedstock 1465.4.4.2 Process Design 1485.4.4.3 Factors Influencing DF 1505.4.4.4 DF by Mixed Consortia 1525.4.4.5 Biohydrogen Production by Using Pure Culture 1545.4.5 Challenges Reported 1545.5 Other Methods of Biohydrogen Production 1545.5.1 Bioelectrolysis 1545.6 Future Perspectives of Biohydrogen Production 157Acknowledgment 158References 1586 Biomass Gasification, Some Theory, and Practical Examples 169Eduardo C. M. Loureiro, Isabella A. Garrett, Clériston Vieira Junior and Sérgio Peres6.1 Introduction 1706.2 Fixed-Bed Reactors 1716.3 Fluidized-Bed Reactors 1736.4 Biomass Characterization 1756.5 Production of Syngas from Wood in a Downdraft Fixed Bed 1766.5.1 Methodology 1766.5.2 Results 1836.6 Construction and Hydrodynamic Characterization of a Bubbling Fluidized-Bed Gasifier 1846.6.1 Introduction 1846.6.2 Methodology 1856.6.2.1 Bed Characterization 1856.6.2.2 Cold Flow Model – CFM 1866.6.2.3 Experimental Vmf 1876.6.2.4 Theoretical Vmf 1896.6.3 Results and Discussions 1906.6.3.1 Velocity of Minimal Fluidization - Vmf 1916.6.3.2 Gasifier Construction 2006.6.3.3 Gasification Experiments 201References 2047 Experimental Investigation on Producer Gas Generation Through Briquettes Using Agricultural Wastes 207Senthil Ramlingam, Balamurugan Rajendiran,Thendral T. and Sudagar S.7.1 Introduction 2087.2 Materials for Present Work 2107.2.1 Feedstock 2107.2.1.1 Sesame Plant 2107.2.1.2 Maize Cob (MC) 2117.2.2 Binder Material 2117.2.3 Briquette Preparation 2127.2.4 Physical Properties of Briquette 2137.2.4.1 Proximate Analysis 2137.2.4.2 Bulk Density 2157.2.5 Ultimate Analysis 2157.2.6 Calorific Value of Feedstock 2157.2.7 Mechanical Properties of Briquette 2167.2.7.1 Compressive Strength 2167.2.7.2 Shatter Index 2167.3 Result and Discussion 2167.3.1 Proximate Analysis 2177.3.1.1 Ash 2177.3.1.2 Moisture 2177.3.1.3 Fixed Carbon 2177.3.1.4 Volatile Matter 2187.3.2 Ultimate Analysis 2187.3.3 Density 2197.3.4 Compressive Strength of Briquette 2197.3.5 Calorific Value 2207.3.6 Comparative Analysis of Properties 2217.4 Generation of Producer Gas 2227.4.1 Effect of Temperature on Producer Gas 2237.5 Producer Gas Suitability in Engines 2247.6 Conclusion 224Bibliography 2258 Biomass Gasification for Distributed Generation and Biochar Production: An Application to the Olive Oil Supply Chain 229Roque Aguado, Antonio Escámez, David Vera, Dolores Eliche-Quesada and Luis Pérez-Villarejo8.1 Introduction 2308.1.1 By-Products of the Olive Oil Industry 2308.1.2 Gasification for Distributed Generation 2328.1.3 Gasification for Biochar Production 2368.2 Methodology 2378.2.1 Description of the Experimental Gasification Plant 2378.2.2 Physicochemical Properties of the By-Products from the Olive Oil Industry 2398.2.3 Experimental Procedure 2438.2.4 Biochar Physicochemical Characterization 2458.3 Results 2458.3.1 Assembly and Installation of the Gasification Plant 2458.3.2 Experimental Results 2468.3.3 Biochar Characterization and Potential for the Olive Oil Industry 2508.4 Economic Impact of Gasification in the Olive Oil Industry 2528.5 Conclusions 256Acknowledgements 257References 2589 Conversion of Agro Wastes to Solid and Gaseous Biofuels through Thermal Cracking Technique 263Senthil Ramlingam, Sudagar Subramanian and Pranesh Ganesan9.1 Introduction 2649.1.2 Energy Resources 2649.2 Biomass 2669.3 Biomass Energy Conversion Technologies 2679.3.1 Thermal Cracking Process 2689.3.1.1 Gasification 2689.3.1.2 Pyrolysis Process 2689.4 Types of Pyrolysis Process 2699.4.1 Conventional or Slow Pyrolysis 2699.4.2 Fast Pyrolysis 2709.4.3 Flash Pyrolysis 2709.5 Mechanism Involved During Pyrolysis 2709.5.1 Mechanism in Hemicelluloses 2709.5.2 Mechanism in Cellulose 2729.5.3 Mechanism in Lignin 2729.6 Pyrolysis Products 2729.6.1 Bio-Oil 2739.6.2 Residue 2739.6.3 Syngas 2749.7 Present Investigation 2749.7.1 Materials and Methods 2759.7.1.1 Cashew Nut Shell 2759.7.1.2 Sawdust 2759.7.1.3 Sugarcane Bagasse 2769.7.1.4 Binder 2779.7.2 Preparation of Briquetting 2789.7.3 Sources for Briquetting 2789.8 Methodology 2789.8.1 Bio-Oil Extraction Process 2819.9 Result and Discussion 2819.9.1 Analysis of Briquette 2819.9.2 Thermo Gravimetric Analysis 2829.9.3 Products of Pyrolysis Process 2839.9.4 Fuel Properties 2849.9.4.1 FTIR 2849.9.4.2 Biochar and Syngas Analysis 2859.9.4.3 Biochar 2859.9.4.4 Syngas 2869.10 Conclusion 286Bibliography 28710 Insights Into the Production of Biochar from Organic Waste 291Jaskiran Kaur and Gaurav Chaudhary10.1 Introduction 29210.2 Organic Waste as Feedstocks for Biochar Production 29310.3 Thermochemical Conversion of Organic Waste into Biochar 29410.4 Factors Affecting Biochar Yield and Properties 29510.4.1 Feedstock Type and Composition 29510.4.2 Pyrolysis Temperature 29610.5 Utilization of Biochar 31010.5.1 As a Soil Amendment 31010.5.2 Carbon Sequestration 31010.5.3 Remediation of Pollutants from Soil 31110.5.4 Water and Wastewater Treatment 31110.6 Conclusion 312References 31311 Thermo-Economic Study of öNORM M7 133 Chips in a Pilot Scale Reactor 321Alok Dhaundiya and Divine AtsuNotation 32111.1 Introduction 32211.2 Material and Methods 32411.2.1 Installation of the Experimental Unit 32411.2.2 Physical Exergy of the System 32711.2.3 Sinking Fund Method 32911.3 Results and Discussion 33111.3.1 Exergy Analysis 33111.3.2 Valuation of Pyrolysis Unit 33711.4 Conclusion 338References 33812 Production and Characterization of Briquettes Produced from Blend of Rice Husk and Water-Hyacinth 341Modestus O. Okwu, Omonigho B. Otanocha, Olusegun D. Samuel and E. E. Akporhonor12.1 Background of the Study 34212.2 Review of Literature 34312.2.1 Renewable Energy Demand 34312.2.2 Briquette Production 34412.2.3 Feedstock for Briquette Production 34412.2.4 Proximate Analysis of Briquettes 34512.3 Materials and Method 34512.3.1 Material Processing, Measurement and Blending 34512.3.2 Proximate Analysis of Sample Materials 34612.3.3 Moisture Content MC (%) 34712.3.4 Ash Content AC (%) 34712.3.5 Volatile Matter (VM) Content 34812.3.6 Fixed Carbon Content FC (%) 34812.3.7 Calorific Value 34812.4 Results and Analysis 34912.4.1 Moisture Content 34912.4.2 Volatile Matter Content 34912.4.3 Ash Content 35012.4.4 Fixed Carbon Content 35012.5 Discussion 35112.6 Conclusion 352Acknowledgement 352References 35213 Torrefaction and Pelletization of Lignocellulosic Biomass for Energy Intensified Fuel Substitute 357Chitra Devi Venkatachalam, Mothil Sengottian and Sathish Raam Ravichandran13.1 Introduction – Biomass as Fuel 35813.2 Torrefaction 35913.2.1 Reaction Mechanism 35913.2.2 Characterization of Torrefied Biomass 36013.2.2.1 Moisture Content 36013.2.2.2 Bulk Density 36013.2.2.3 Grindability 36113.2.2.4 High Heating Value 36113.2.2.5 Mass Yield, Energy Yield and Enhancement Factor 36213.2.2.6 Particle Size Distribution 36313.2.3 Reactors for Torrefaction 36413.2.3.1 Fixed Bed Reactor 36413.2.3.2 Moving Bed Reactor 36413.2.3.3 Entrained Flow Reactor 36413.2.3.4 Fluidized Bed Reactor 36413.2.3.5 Rotary Drum Reactor 36513.2.3.6 Microwave Reactor 36513.2.3.7 Hydrothermal Reactor 36513.3. Pelletization 36513.3.1 Pelletization of Torrefied Biomass 36513.3.2 Types of Pelletizers 36713.3.2.1 Flat Die Pellet Mill 36713.3.2.2 Round Die Pellet Mill 36713.3.3 Influence of Process Parameters during the Pelletization 36813.3.3.1 Moisture Content 36813.3.3.2 Pelletization Temperature 36813.3.3.3 Particle Size 36813.3.3.4 Press Channel Dimensions 36813.3.3.5 Pelletization Pressure 36813.3.3.6 Torrefaction Temperature 36913.4 Application of Torrefaction Process 36913.4.1 Using Torrefaction as Pre-Treatment Step for Biomass Gasification 36913.4.2 Blending Torrefied Biomass with Coal and Co-Firing for Energy Production 36913.4.3 Fuel for Steel Making in Blast Furnace 37013.5 Conclusion 370References 370Index 375