<p>Preface xv</p> <p><b>1 Biogas, Biomethane and BioCNG: Definitions, Technologies and Solutions 1<br /></b><i>Alessandra Lee Barbosa Firmo, Fabrícia Maria Santana Silva, Ingrid Roberta de F.S. Alves, Ericka Patrícia Lima de Brito and Leandro Cesar Santos da Silva</i></p> <p>1.1 Definitions and Sources of Production of Biogas, Biomethane and BioCNG 2</p> <p>1.2 Production Chains, Utilization and Valorization of Biogas 5</p> <p>1.2.1 Anaerobic Digesters 8</p> <p>1.2.1.1 Techniques for Optimization of Anaerobic Digestion 12</p> <p>1.2.1.2 Biogas Recovery Plants 14</p> <p>1.2.1.3 Biofertilizers – Material Valorization 15</p> <p>1.2.2 Landfills: Final Disposal and Biogasvalorization 16</p> <p>1.3 Uses of Biomethane: Practice Examples 20</p> <p>1.4 Challenges and Opportunities 21</p> <p>References 25</p> <p><b>2 Biomethanisation: Biogas Production Technologies 33<br /></b><i>Gabor Z. Szelenyi</i></p> <p>2.1 Relevance 34</p> <p>2.2 Oxidation without Oxygen – Anaerobic Biodegradation of the Organic Matter 35</p> <p>2.3 Bifurcating Metabolic Pathways 35</p> <p>2.4 Methanogenesis 37</p> <p>2.5 Imitation of Nature – Improvement through Controlled Environment 40</p> <p>2.6 Operational Challenges 44</p> <p>2.7 Post-Treatment 47</p> <p>2.8 Outlook – Fields of Further Research and Technological Development 49</p> <p>2.9 Conclusion – Development Goals 55</p> <p>Acknowledgments 60</p> <p>References 60</p> <p><b>3 Effect of Process Parameters on Biogas Yield: A Systematic Review 65<br /></b><i>H.O. Omoregbee, M. O. Okwu, L.K. Tartibu, A.E. Ivbanikaro, M.U. Olanipekun and A.B. Edward</i></p> <p>3.1 Introduction 66</p> <p>3.2 Effect of Process Parameters on Biogas Yield 67</p> <p>3.2.1 Temperature Effect on Biogas Yield 67</p> <p>3.2.2 Effect of pH on Biogas Yield 69</p> <p>3.2.3 Effect of Hydraulic Retention Time (HRT) on Biogas Yield 70</p> <p>3.2.4 Effect of Agitation or Stirring on Biogas Yield 71</p> <p>3.3 Pre-Treatment Process 72</p> <p>3.3.1 Mechanical Treatment 73</p> <p>3.3.2 Microwave Irradiation 73</p> <p>3.3.3 Thermal Pre-Treatment Process 73</p> <p>3.3.4 Chemical Treatment 74</p> <p>3.3.4.1 Acid 74</p> <p>3.3.4.2 Alkali 74</p> <p>3.3.5 Biological Treatment 75</p> <p>3.3.6 Biochemical Methane Potential 76</p> <p>3.4 Effect of Co-Digestion of Two or More Substrates 76</p> <p>3.5 Effect of Total Solid ContenT (TSC) 78</p> <p>3.5.1 Acidogenesis 79</p> <p>3.5.2 Hydrolysis 79</p> <p>3.5.3 Methanogenesis 80</p> <p>3.5.4 Acetogenesis 80</p> <p>3.6 Addressing AD Bottlenecks Caused by the Physicochemical Properties of Substrate 80</p> <p>3.6.1 Carbon Dioxide Removal Technologies for Upgrading Biogas 81</p> <p>3.7 Conclusion 83</p> <p>References 84</p> <p><b>4 Biogas for Electricity Generation in Nigeria: A Systematic Review of the Prospects, Efforts and Contemporary Challenges 91<br /></b><i>Victor M. Mbachu, Modestus O. Okwu, Celine C. Chiabuotu and Lagouge K. Tartibu</i></p> <p>4.1 Introduction 92</p> <p>4.2 Bioenergy and Biogas Technology 93</p> <p>4.3 Chronicle of Research Efforts in Biogas Technology 94</p> <p>4.3.1 Assessment of Biomass Potential for Biogas and Electricity Generation 94</p> <p>4.3.2 Use of Co-Digestion for Enhanced Production 95</p> <p>4.3.3 Enhancement of Biogas Production Using Pre-Treatment of Feedstock 96</p> <p>4.3.4 Inoculation of Substrate for Biogas Production 96</p> <p>4.3.5 Optimization of Biogas Production Process Parameters 97</p> <p>4.3.6 Digester Design 97</p> <p>4.3.7 Upgrading and Purification of Biogas 98</p> <p>4.3.8 Modeling of Biogas Production 99</p> <p>4.4 Current Research and Developmental Trend in Biogas Technology 100</p> <p>4.5 Conclusion 101</p> <p>References 101</p> <p><b>5 Biohydrogen Production Technologies: Current Status, Challenges, and Future Perspectives 115<br /></b><i>Akanksha Jain, Eeshita Das, Venkata Giridhar Poosarla and Gobinath Rajagopalan</i></p> <p>5.1 Introduction 116</p> <p>5.2 Hydrogen vs. Biohydrogen 116</p> <p>5.3 Biohydrogen from Light Dependent Processes 119</p> <p>5.3.1 Photo-Fermentation (PF) 119</p> <p>5.3.1.1 Biocatalysts Involved in PF 120</p> <p>5.3.1.2 General Mechanism of Biohydrogen Production from PF 123</p> <p>5.3.1.3 Current Status of PF 124</p> <p>5.3.1.4 Major Factors that Influence the PF Process 124</p> <p>5.3.1.5 Challenges Reported 134</p> <p>5.3.2 Biophotolysis (BP) 134</p> <p>5.3.2.1 General Mechanism of Hydrogen Production from Biophotolysis 136</p> <p>5.3.2.2 Current Status of BP 136</p> <p>5.3.2.3 Major Factors Influence BP 137</p> <p>5.3.2.4 Challenges Reported 141</p> <p>5.4 Biohydrogen Production from Dark Fermentation 141</p> <p>5.4.1 Dark Fermentation (DF) 141</p> <p>5.4.2 Biocatalysts Involved in DF 143</p> <p>5.4.2.1 Formate Lyase Complex 144</p> <p>5.4.3 General Mechanism and Biochemistry of Biohydrogen Production from DF 144</p> <p>5.4.3.1 Clostridia 144</p> <p>5.4.3.2 Non-Clostridia 146</p> <p>5.4.4 Current Status 146</p> <p>5.4.4.1 Feedstock 146</p> <p>5.4.4.2 Process Design 148</p> <p>5.4.4.3 Factors Influencing DF 150</p> <p>5.4.4.4 DF by Mixed Consortia 152</p> <p>5.4.4.5 Biohydrogen Production by Using Pure Culture 154</p> <p>5.4.5 Challenges Reported 154</p> <p>5.5 Other Methods of Biohydrogen Production 154</p> <p>5.5.1 Bioelectrolysis 154</p> <p>5.6 Future Perspectives of Biohydrogen Production 157</p> <p>Acknowledgment 158</p> <p>References 158</p> <p><b>6 Biomass Gasification, Some Theory, and Practical Examples 169<br /></b><i>Eduardo C. M. Loureiro, Isabella A. Garrett, Clériston Vieira Junior and Sérgio Peres</i></p> <p>6.1 Introduction 170</p> <p>6.2 Fixed-Bed Reactors 171</p> <p>6.3 Fluidized-Bed Reactors 173</p> <p>6.4 Biomass Characterization 175</p> <p>6.5 Production of Syngas from Wood in a Downdraft Fixed Bed 176</p> <p>6.5.1 Methodology 176</p> <p>6.5.2 Results 183</p> <p>6.6 Construction and Hydrodynamic Characterization of a Bubbling Fluidized-Bed Gasifier 184</p> <p>6.6.1 Introduction 184</p> <p>6.6.2 Methodology 185</p> <p>6.6.2.1 Bed Characterization 185</p> <p>6.6.2.2 Cold Flow Model – CFM 186</p> <p>6.6.2.3 Experimental Vmf 187</p> <p>6.6.2.4 Theoretical Vmf 189</p> <p>6.6.3 Results and Discussions 190</p> <p>6.6.3.1 Velocity of Minimal Fluidization - Vmf 191</p> <p>6.6.3.2 Gasifier Construction 200</p> <p>6.6.3.3 Gasification Experiments 201</p> <p>References 204</p> <p><b>7 Experimental Investigation on Producer Gas Generation Through Briquettes Using Agricultural Wastes 207<br /></b><i>Senthil Ramlingam, Balamurugan Rajendiran,Thendral T. and Sudagar S.</i></p> <p>7.1 Introduction 208</p> <p>7.2 Materials for Present Work 210</p> <p>7.2.1 Feedstock 210</p> <p>7.2.1.1 Sesame Plant 210</p> <p>7.2.1.2 Maize Cob (MC) 211</p> <p>7.2.2 Binder Material 211</p> <p>7.2.3 Briquette Preparation 212</p> <p>7.2.4 Physical Properties of Briquette 213</p> <p>7.2.4.1 Proximate Analysis 213</p> <p>7.2.4.2 Bulk Density 215</p> <p>7.2.5 Ultimate Analysis 215</p> <p>7.2.6 Calorific Value of Feedstock 215</p> <p>7.2.7 Mechanical Properties of Briquette 216</p> <p>7.2.7.1 Compressive Strength 216</p> <p>7.2.7.2 Shatter Index 216</p> <p>7.3 Result and Discussion 216</p> <p>7.3.1 Proximate Analysis 217</p> <p>7.3.1.1 Ash 217</p> <p>7.3.1.2 Moisture 217</p> <p>7.3.1.3 Fixed Carbon 217</p> <p>7.3.1.4 Volatile Matter 218</p> <p>7.3.2 Ultimate Analysis 218</p> <p>7.3.3 Density 219</p> <p>7.3.4 Compressive Strength of Briquette 219</p> <p>7.3.5 Calorific Value 220</p> <p>7.3.6 Comparative Analysis of Properties 221</p> <p>7.4 Generation of Producer Gas 222</p> <p>7.4.1 Effect of Temperature on Producer Gas 223</p> <p>7.5 Producer Gas Suitability in Engines 224</p> <p>7.6 Conclusion 224</p> <p>Bibliography 225</p> <p><b>8 Biomass Gasification for Distributed Generation and Biochar Production: An Application to the Olive Oil Supply Chain 229<br /></b><i>Roque Aguado, Antonio Escámez, David Vera, Dolores Eliche-Quesada and Luis Pérez-Villarejo</i></p> <p>8.1 Introduction 230</p> <p>8.1.1 By-Products of the Olive Oil Industry 230</p> <p>8.1.2 Gasification for Distributed Generation 232</p> <p>8.1.3 Gasification for Biochar Production 236</p> <p>8.2 Methodology 237</p> <p>8.2.1 Description of the Experimental Gasification Plant 237</p> <p>8.2.2 Physicochemical Properties of the By-Products from the Olive Oil Industry 239</p> <p>8.2.3 Experimental Procedure 243</p> <p>8.2.4 Biochar Physicochemical Characterization 245</p> <p>8.3 Results 245</p> <p>8.3.1 Assembly and Installation of the Gasification Plant 245</p> <p>8.3.2 Experimental Results 246</p> <p>8.3.3 Biochar Characterization and Potential for the Olive Oil Industry 250</p> <p>8.4 Economic Impact of Gasification in the Olive Oil Industry 252</p> <p>8.5 Conclusions 256</p> <p>Acknowledgements 257</p> <p>References 258</p> <p><b>9 Conversion of Agro Wastes to Solid and Gaseous Biofuels through Thermal Cracking Technique 263<br /></b><i>Senthil Ramlingam, Sudagar Subramanian and Pranesh Ganesan</i></p> <p>9.1 Introduction 264</p> <p>9.1.2 Energy Resources 264</p> <p>9.2 Biomass 266</p> <p>9.3 Biomass Energy Conversion Technologies 267</p> <p>9.3.1 Thermal Cracking Process 268</p> <p>9.3.1.1 Gasification 268</p> <p>9.3.1.2 Pyrolysis Process 268</p> <p>9.4 Types of Pyrolysis Process 269</p> <p>9.4.1 Conventional or Slow Pyrolysis 269</p> <p>9.4.2 Fast Pyrolysis 270</p> <p>9.4.3 Flash Pyrolysis 270</p> <p>9.5 Mechanism Involved During Pyrolysis 270</p> <p>9.5.1 Mechanism in Hemicelluloses 270</p> <p>9.5.2 Mechanism in Cellulose 272</p> <p>9.5.3 Mechanism in Lignin 272</p> <p>9.6 Pyrolysis Products 272</p> <p>9.6.1 Bio-Oil 273</p> <p>9.6.2 Residue 273</p> <p>9.6.3 Syngas 274</p> <p>9.7 Present Investigation 274</p> <p>9.7.1 Materials and Methods 275</p> <p>9.7.1.1 Cashew Nut Shell 275</p> <p>9.7.1.2 Sawdust 275</p> <p>9.7.1.3 Sugarcane Bagasse 276</p> <p>9.7.1.4 Binder 277</p> <p>9.7.2 Preparation of Briquetting 278</p> <p>9.7.3 Sources for Briquetting 278</p> <p>9.8 Methodology 278</p> <p>9.8.1 Bio-Oil Extraction Process 281</p> <p>9.9 Result and Discussion 281</p> <p>9.9.1 Analysis of Briquette 281</p> <p>9.9.2 Thermo Gravimetric Analysis 282</p> <p>9.9.3 Products of Pyrolysis Process 283</p> <p>9.9.4 Fuel Properties 284</p> <p>9.9.4.1 FTIR 284</p> <p>9.9.4.2 Biochar and Syngas Analysis 285</p> <p>9.9.4.3 Biochar 285</p> <p>9.9.4.4 Syngas 286</p> <p>9.10 Conclusion 286</p> <p>Bibliography 287</p> <p><b>10 Insights Into the Production of Biochar from Organic Waste 291<br /></b><i>Jaskiran Kaur and Gaurav Chaudhary</i></p> <p>10.1 Introduction 292</p> <p>10.2 Organic Waste as Feedstocks for Biochar Production 293</p> <p>10.3 Thermochemical Conversion of Organic Waste into Biochar 294</p> <p>10.4 Factors Affecting Biochar Yield and Properties 295</p> <p>10.4.1 Feedstock Type and Composition 295</p> <p>10.4.2 Pyrolysis Temperature 296</p> <p>10.5 Utilization of Biochar 310</p> <p>10.5.1 As a Soil Amendment 310</p> <p>10.5.2 Carbon Sequestration 310</p> <p>10.5.3 Remediation of Pollutants from Soil 311</p> <p>10.5.4 Water and Wastewater Treatment 311</p> <p>10.6 Conclusion 312</p> <p>References 313</p> <p><b>11 Thermo-Economic Study of öNORM M7 133 Chips in a Pilot Scale Reactor 321<br /></b><i>Alok Dhaundiya and Divine Atsu</i></p> <p>Notation 321</p> <p>11.1 Introduction 322</p> <p>11.2 Material and Methods 324</p> <p>11.2.1 Installation of the Experimental Unit 324</p> <p>11.2.2 Physical Exergy of the System 327</p> <p>11.2.3 Sinking Fund Method 329</p> <p>11.3 Results and Discussion 331</p> <p>11.3.1 Exergy Analysis 331</p> <p>11.3.2 Valuation of Pyrolysis Unit 337</p> <p>11.4 Conclusion 338</p> <p>References 338</p> <p><b>12 Production and Characterization of Briquettes Produced from Blend of Rice Husk and Water-Hyacinth 341<br /></b><i>Modestus O. Okwu, Omonigho B. Otanocha, Olusegun D. Samuel and E. E. Akporhonor</i></p> <p>12.1 Background of the Study 342</p> <p>12.2 Review of Literature 343</p> <p>12.2.1 Renewable Energy Demand 343</p> <p>12.2.2 Briquette Production 344</p> <p>12.2.3 Feedstock for Briquette Production 344</p> <p>12.2.4 Proximate Analysis of Briquettes 345</p> <p>12.3 Materials and Method 345</p> <p>12.3.1 Material Processing, Measurement and Blending 345</p> <p>12.3.2 Proximate Analysis of Sample Materials 346</p> <p>12.3.3 Moisture Content MC (%) 347</p> <p>12.3.4 Ash Content AC (%) 347</p> <p>12.3.5 Volatile Matter (VM) Content 348</p> <p>12.3.6 Fixed Carbon Content FC (%) 348</p> <p>12.3.7 Calorific Value 348</p> <p>12.4 Results and Analysis 349</p> <p>12.4.1 Moisture Content 349</p> <p>12.4.2 Volatile Matter Content 349</p> <p>12.4.3 Ash Content 350</p> <p>12.4.4 Fixed Carbon Content 350</p> <p>12.5 Discussion 351</p> <p>12.6 Conclusion 352</p> <p>Acknowledgement 352</p> <p>References 352</p> <p><b>13 Torrefaction and Pelletization of Lignocellulosic Biomass for Energy Intensified Fuel Substitute 357<br /></b><i>Chitra Devi Venkatachalam, Mothil Sengottian and Sathish Raam Ravichandran</i></p> <p>13.1 Introduction – Biomass as Fuel 358</p> <p>13.2 Torrefaction 359</p> <p>13.2.1 Reaction Mechanism 359</p> <p>13.2.2 Characterization of Torrefied Biomass 360</p> <p>13.2.2.1 Moisture Content 360</p> <p>13.2.2.2 Bulk Density 360</p> <p>13.2.2.3 Grindability 361</p> <p>13.2.2.4 High Heating Value 361</p> <p>13.2.2.5 Mass Yield, Energy Yield and Enhancement Factor 362</p> <p>13.2.2.6 Particle Size Distribution 363</p> <p>13.2.3 Reactors for Torrefaction 364</p> <p>13.2.3.1 Fixed Bed Reactor 364</p> <p>13.2.3.2 Moving Bed Reactor 364</p> <p>13.2.3.3 Entrained Flow Reactor 364</p> <p>13.2.3.4 Fluidized Bed Reactor 364</p> <p>13.2.3.5 Rotary Drum Reactor 365</p> <p>13.2.3.6 Microwave Reactor 365</p> <p>13.2.3.7 Hydrothermal Reactor 365</p> <p>13.3. Pelletization 365</p> <p>13.3.1 Pelletization of Torrefied Biomass 365</p> <p>13.3.2 Types of Pelletizers 367</p> <p>13.3.2.1 Flat Die Pellet Mill 367</p> <p>13.3.2.2 Round Die Pellet Mill 367</p> <p>13.3.3 Influence of Process Parameters during the Pelletization 368</p> <p>13.3.3.1 Moisture Content 368</p> <p>13.3.3.2 Pelletization Temperature 368</p> <p>13.3.3.3 Particle Size 368</p> <p>13.3.3.4 Press Channel Dimensions 368</p> <p>13.3.3.5 Pelletization Pressure 368</p> <p>13.3.3.6 Torrefaction Temperature 369</p> <p>13.4 Application of Torrefaction Process 369</p> <p>13.4.1 Using Torrefaction as Pre-Treatment Step for Biomass Gasification 369</p> <p>13.4.2 Blending Torrefied Biomass with Coal and Co-Firing for Energy Production 369</p> <p>13.4.3 Fuel for Steel Making in Blast Furnace 370</p> <p>13.5 Conclusion 370</p> <p>References 370</p> <p>Index 375</p>