Biogas Production: Pretreatment Methods in Anaerobic Digestion

Biogas Production covers the most cutting–edge pretreatment processes being used and studied today for the production of biogas.

As an increasingly important piece of the "energy pie," biogas and other biofuels are being used more and more around the world in every conceivable area of industry and could be a partial answer to the energy problem and the elimination of global warming.

This book will highlight the recent advances in the pretreatment and value addition of lignocellulosic wastes (LCW) with the main focus on domestic and agro–industrial residues. Mechanical, physical, and biological treatment systems are brought into perspective. The main value–added products from lignocellulosic wastes are summarized in a manner that pinpoints the most recent trends and the future directions.

Physico–chemical and biological treatment systems seem to be the most favored options while biofuels, biodegradable composites, and biosorbents production paint a bright picture of the current and future bio–based products. Engineered microbes seem to tackle the problem of bioconversion of substrates that are otherwise nonconvertible by conventional wild strains. Although the main challenge facing LCW utilization is the high costs involved in treatment and production processes, some recent affordable processes with promising results have been proposed. Future trends are being directed to nanobiotechnology and genetic engineering for improved processes and products.

This groundbreaking new volume:

Is a comprehensive compilation of anaerobic digestion methods, the treatment processes used for organic wastes and process residues

Covers hydrolysis, the rate–limiting step of anaerobic digestion of semi–solid wastes, in which both solubilization of particulate matter and biological decomposition of organic polymers to monomers or dimers take place

Offers an in–depth study of potential unconventional feedstocks for anaerobic digestion technology and their practical applications

Is in line with the growing green chemistry and green engineering practices, covering research and development of unconventional pretreatment techniques to improve the kinetics of hydrolysis and hence enhance the biogas production rates and yields from lignocellulosic biomass during anaerobic digestion processes.

Preface xv

Acknowledgements xvii

Special Contributor xviii

Editor xix

List of Contributors xxi

1. Anaerobic Digestion: Pretreatments of Substrates1
Tanta Forster–Carnetro, Ricardo Isaac, Montserrat Pérez,and Ciarita Schvartz

1.1 Pretreatments in Anaerobic Digestion Process 2

1.2 Physical Pretreatment 6

1.3 Chemical Pretreatment 15

1.4 Biological Pretreatment 17

1.5 Combined Pretreatment 18

1.6 Concluding Note 19

2. Recalcitrance of Lignocellulosic Biomass to AnaerobicDigestion 27
Mohammad J. Taherzadeh and Azam Jeihanipour

2.1 Introduction 27

2.2 Plant Cell Wall Anatomy 28

2.3 Chemistry of Cell Wall Polymers 30

2.4 Molecular Interactions Between Cell Wall Polymers 39

2.5 Plant Cell Wall Molecular Architecture 40

2.6 Recalcitrance of Plant Cell Wall Cellulose 42

2.7 Reduction of Biomass Recalcitrance 46

2.8 Concluding Note 50

3. The Effect of Physical, Chemical, and BiologicalPretreatments of Biomass on its Anaerobic Digestibility and BiogasProduction 55
Katerina Stamatelatou, Georgia Antonopoulou, loanna Ntaikou, andGerasimos Lyberatos

3.1 Introduction 56

3.2 Pretreatment Methods for Lignocellulosic Biomass 57

3.3 Pretreatment Methods for Sewage Sludge 77

3.4 Concluding Note 84

4. Application of Ultrasound Pretreatment for SludgeDigestion 91
Show Kuan Yeow and Wong Lai Peng

4.1 Introduction 91

4.2 Anaerobic Digestion 93

4.3 Overview of Pretreatment Methods for Anaerobic Digestion95

4.4 Fundamental of Ultrasound 100

4.5 Bubbles Dynamic 103

4.6 Effects of Ultrasound 106

4.7 Ultrasound Applications 109

4.8 Ultrasonication for Anaerobic Digesion 116

4.9 Evaluation on Sludge Disintegration 126

4.10 Conclusions 131

5. Microwave Sludge Irradiation 137
Cigdetn Esktctoglu and Giampiero Galvagno

5.1 Introduction 137

5.2 Microwave Theory 139

5.3 Microwave Irradiation for Waste Sludge Treatment 144

5.4 Industrial Microwave Applications 147

5.5 Microwave Absorbing Materials and Ionic Liquids 148

5.6 Sludge Pretreatment Similar to Microwave Irradiation 151

5.7 Concluding Notes 151

6. Hydrolytic Enzymes Enhancing Anaerobic Digestion157
Teresa Suárez Quiñones, Matthias Plöchl, KatrinPäzolt, Jörn Budde, Robert Kausmann, Edith Nettmann, andMonika Heiermann

6.1 Introduction 158

6.2 Where and How can Enzymes be Applied? 170

6.3 Impact of Enzyme Application 178

6.4 Economic Assessment 191

6.5 Concluding Note 192

7. Oxidizing Agents and Organic Solvents as Pretreatment forAnaerobic Digestion 199
Lise Appels, Jan Van Impe, and Raf Dewil

7.1 Oxidative Pretreatment Methods 199

7.2 Organic Solvents 210

7.3 Concluding Note 212

8. Anaerobic Digestion and Biogas Utilization in Greece:Current Status and Perspectives 215
Avraam Karagiannidis, George Perkoultdts, and ApostólosMalamakts

8.1 Assessment of Existing Biogas Installations 215

8.2 Use of Waste Material for Biogas Production 217

8.3 Feedstock Availability and Agricultural Structures 219

8.4 Purification of Biogas for Insertion in the Natural Gas Grid224

8.5 Biogas Utilization 226

8.6 Concluding Note 227

9. Original Research: Investigating the Potential of UsingBiogas in Cooking Stove in Rodrigues 229
Dinesh Surroop and Osman Dina Bégué

9.1 Energy Crisis and Future Challenges 230

9.2 Case Study of Rodrigues 231

9.3 Rationale of Research Study 233

9.4 Research Methodology 234

9.5 Reactor Design Considerations 241

9.6 Results, Findings and Discussions 247

9.7 Conclusions 257

10. Optimizing and Modeling the Anaerobic Digestion ofLignocellulosic Wastes by Rumen Cultures 259
Zhen–Hu Hu and Han–Qing Yu

10.1 Introduction 260

10.2 Materials and Methods 262

10.3 Optimizing the Anaerobic Digestion of Microwave–PretreatedCattail by Rumen Cultures 266

10.4 Modeling the Anaerobic Digestion of Cattail by RumenCultures 275

10.5 Concluding Note 287

11. Pretreatment of Biocatalyst as Viable Option forSustained Production of Biohydrogen from Wastewater Treatment291
S. Venkata Mohan and R. Kannatah Goud

11.1 Introduction 292

11.2 Pretreatment of Biocatalyst 294

11.3 Combined Pretreatment 300

11.4 Influence of Pretreatment on Wastewater Treatment 302

11.5 Microbial Diversity 303

11.6 Summary and Future Scope 304

Acknowledgements 305

References 305

Index 313

Ackmez Mudhoo, BEng, MPhil, is Lecturer in the Department of Chemical and Environmental Engineering at the University of Mauritius. His main research interests encompass bioremediation of organic wastes and other process residues using composting, anaerobic digestion, and other green tehniques. He has dozens of international journal publications and conference papers to his credit. He is also a peer reviewer on numerous journals, and is the editor for two international research journals.