Pandey / Bhaskar / St”cker Recent Advances in Thermochemical Conversion of Biomass

1. Auflage 2015
ISBN: 978-0-444-63290-6
Verlag: Elsevier Science & Techn.
Format: EPUB
Kopierschutz: 6 - ePub Watermark

E-Book, Englisch, 504 Seiten

This book provides general information and data on one of the most promising renewable energy sources: biomass for its thermochemical conversion. During the last few years, there has been increasing focus on developing the processes and technologies for the conversion of biomass to liquid and gaseous fuels and chemicals, in particular to develop low-cost technologies. This book provides date-based scientific information on the most advanced and innovative processing of biomass as well as the process development elements on thermochemical processing of biomass for the production of biofuels and bio-products on (biomass-based biorefinery). The conversion of biomass to biofuels and other value-added products on the principle biorefinery offers potential from technological perspectives as alternate energy.ÿThe book covers intensive R&D and technological developments done during the last few years in the area of renewable energy utilizing biomass as feedstock and will be highly beneficial for the researchers, scientists and engineers working in the area of biomass-biofuels- biorefinery. - Provides the most advanced and innovative thermochemical conversion technology for biomass - Provides information on large scales such as thermochemical biorefinery - Useful for researchers intending to study scale up - Serves as both a textbook for graduate students and a reference book for researchers - Provides information on integration of process and technology on thermochemical conversion of biomass

Autoren/Hrsg.

Pandey, Ashok

Bhaskar, Thallada

Stöcker, Michael

Sukumaran, Rajeev

Inhaltsverzeichnis

1;Front Cover;1
2;Recent Advances in Thermochemical Conversion of Biomass;4
3;Copyright;5
4;Contents ;6
5;Contributors;10
6;Preface ;12
7;Part I: General ;14
7.1;Chapter 1: Advances in Thermochemical Conversion of Biomass—Introduction;16
7.1.1;1.1. World Energy Demand and Supply/Preamble;16
7.1.2;1.2. Biofuel Policies;19
7.1.2.1;1.2.1. Renewable Fuel Standards in the United States;19
7.1.2.2;1.2.2. EU Biofuels Policy;19
7.1.3;1.3. Biomass—an Opportunity;20
7.1.3.1;1.3.1. Generations of Biofuels;20
7.1.3.2;1.3.2. Components of Lignocellulosic Biomass;20
7.1.3.3;1.3.3. Agricultural Residues;21
7.1.3.4;1.3.4. Forest Residues;21
7.1.3.5;1.3.5. Energy Crops;22
7.1.3.6;1.3.6. Global Biomass Potential;22
7.1.3.6.1;The United States of America;23
7.1.3.6.2;European Union;24
7.1.3.6.3;BRIC (Brazil, Russia, India, and China);24
7.1.3.6.3.1;Brazil;24
7.1.3.6.3.2;Russia;25
7.1.3.6.3.3;India;25
7.1.3.6.3.4;China;26
7.1.4;1.4. Biomass Conversion Methods;26
7.1.5;1.5. Advantages of Thermochemical Conversion of Biomass;26
7.1.5.1;1.5.1. Thermochemical Methods of Conversion;27
7.1.5.2;1.5.2. Feedstock Handling Methods;27
7.1.5.3;1.5.3. Methods of Thermochemical Conversion;27
7.1.5.4;1.5.4. Syngas Platform;34
7.1.5.5;1.5.5. C6 and C6 /C5 Sugar Platforms;35
7.1.5.6;1.5.6. Lignin Platform;35
7.1.5.7;1.5.7. Pyrolysis Oil Platform;35
7.1.6;1.6. Concept of Biorefinery;36
7.1.7;1.7. Scientometric Analysis;38
7.1.8;1.8. Conclusion and Perspectives;42
7.1.9;References;42
7.2;Chapter 2: Feedstock Suitability for Thermochemical Processes;44
7.2.1;2.1. Introduction;44
7.2.1.1;2.1.1. Why Biofuel?;44
7.2.1.2;2.1.2. Biobased Society and Economy;45
7.2.2;2.2. Processes for the Conversion of Biomass into Various Products in a Biorefinery;45
7.2.3;2.3. Thermochemical Conversion;46
7.2.3.1;Feedstocks for Thermochemical Conversion;47
7.2.3.2;Feedstock Classification;48
7.2.3.3;Compositional Analysis of the Feedstock;50
7.2.3.4;2.3.1. Diversity of Feedstock Types that Can Be Utilized for Thermochemical Conversion;50
7.2.4;2.4. Nonprocess Parameters Affecting the Conversion Process;66
7.2.4.1;2.4.1. Process Efficiencies as Affected by Feedstock Properties/Composition;66
7.2.4.1.1;Combustion;68
7.2.4.1.2;Gasification;70
7.2.4.1.3;Pyrolysis;72
7.2.4.2;2.4.2. Ways to Overcome Drawbacks of the Feedstock Composition-Necessity for Pretreatment;75
7.2.4.2.1;Torrefaction as a Biomass Pretreatment for Improvement of Conversion Efficiency;76
7.2.4.2.2;Leaching/Acid or Alkali Pretreatment;78
7.2.5;2.5. Conclusions and Perspectives;79
7.2.6;References;80
7.3;Chapter 3: Analytical Techniques as a Tool to Understand the Reaction Mechanism;88
7.3.1;3.1. Introduction;88
7.3.2;3.2. Composition of Lignocellulosic Biomass Samples;89
7.3.3;3.3. Thermal Analysis;89
7.3.3.1;3.3.1. Reaction Heat of the Biomass Decomposition;89
7.3.3.2;3.3.2. Thermogravimetric Analysis of Biomass;91
7.3.3.3;3.3.3. Thermal Decomposition Products as Measured by Thermogravimetry/Mass spectrometry;95
7.3.3.4;3.3.4. Reaction Kinetic Modeling Using Thermogravimetric Data;97
7.3.4;3.4. Analytical Pyrolysis;99
7.3.4.1;3.4.1. Pyrolysis Techniques;99
7.3.4.2;3.4.2. Pyrolysis of Macromolecular Biomass Constituents;99
7.3.4.3;3.4.3. Pyrolysis of Whole Biomass Samples;101
7.3.5;3.5. Reaction Mechanisms of the Thermal Decomposition;108
7.3.5.1;3.5.1. Cellulose Decomposition;108
7.3.5.2;3.5.2. Hemicellulose Decomposition;110
7.3.5.3;3.5.3. Lignin Decomposition;112
7.3.5.4;3.5.4. Mechanisms of Biomass Pyrolysis;112
7.3.6;3.6. Effect of Inorganic Materials on the Decomposition Mechanism;113
7.3.7;3.7. Effect of Torrefaction on the Composition and Decomposition Mechanisms;115
7.3.8;Acknowledgments;116
7.3.9;References;117
7.4;Chapter 4: Catalysts for Thermochemical Conversion of Biomass;122
7.4.1;4.1. Introduction;122
7.4.2;4.2. Biomass and Biofuels;123
7.4.2.1;4.2.1. Biomass Conversion Methods;123
7.4.3;4.3. Properties of Catalysts;124
7.4.4;4.4. Types of Catalysts;125
7.4.4.1;4.4.1. Zeolites;125
7.4.4.1.1;Three-Dimensional Zeolites;125
7.4.4.1.2;Two-Dimensional Zeolites;125
7.4.4.1.3;Hierarchical Zeolites;125
7.4.4.1.4;Natural Zeolites;126
7.4.4.2;4.4.2. Biomass Conversion Residues as Catalyst/Support;126
7.4.4.2.1;Biochar as a Catalyst Support;126
7.4.4.2.2;Sulfonated Biochar as Catalyst;126
7.4.4.2.3;Fly Ash;126
7.4.4.2.4;Rice Husk Ash;126
7.4.5;4.5. Catalysts for the Conversion of Biomass;127
7.4.5.1;4.5.1. Catalysts for Holocellulose Conversion to Chemicals;127
7.4.5.1.1;Cellulose Hydrolysis;127
7.4.5.1.2;Cellulose Hydrolysis/Hydrogenation for Hexitols Production;127
7.4.5.1.3;Cellulose Biphasic Catalytic Conversion into Furan-Based Biofuels;128
7.4.5.1.4;Catalytic Conversion into Valeric Biofuels and Liquid Alkenes;128
7.4.5.2;4.5.2. Catalysts for Lignin Valorization;129
7.4.5.3;4.5.3. Catalysts for Gasification;129
7.4.5.3.1;Dolomite Catalysts;129
7.4.5.3.2;Nickel and Other Metal Catalysts;130
7.4.5.3.3;Alkali Metal and Other Catalysts;130
7.4.5.4;4.5.4. Catalysts for Hydrothermal Gasification;130
7.4.5.4.1;Activated Carbons;131
7.4.5.4.2;Transition Metals;131
7.4.5.4.3;Oxides;132
7.4.5.5;4.5.5. Catalysts for the Fischer-Tropsch Process;132
7.4.5.6;4.5.6. Catalysts for Hydrothermal Liquefaction;132
7.4.5.7;4.5.7. Catalysts for Pyrolysis;132
7.4.5.7.1;Catalysts for Slow Pyrolysis;133
7.4.5.7.2;Catalysts for Fast Pyrolysis;134
7.4.5.7.3;Catalysts for Microwave Pyrolysis;134
7.4.5.7.4;Catalytic Pyrolysis for Production of Aromatics;135
7.4.5.8;4.5.8. Catalysts for Upgradation of Bio-oil;135
7.4.5.8.1;Zeolites for Hydrotreatment;135
7.4.5.8.2;Metals in Hydrotreating Reactions;136
7.4.5.8.3;Hydrodeoxygenation;136
7.4.5.8.4;Catalytic Cracking of Bio-oil;137
7.4.5.8.5;Catalysts for Py-GC/MS;137
7.4.5.8.6;Catalysts for Ex Situ Bio-oil Upgradation;138
7.4.5.8.7;Catalysts for Aqueous Phase Reforming (APR);139
7.4.5.8.8;Catalysts for Steam Reforming of Bio-oil;139
7.4.6;4.6. Catalysts for Hydropyrolysis of Biomass;139
7.4.7;4.7. Catalysts for Biochar Gasification;140
7.4.8;4.8. Conclusion and Perspectives;140
7.4.9;Acknowledgments;141
7.4.10;References;141
7.5;Chapter 5: Artificial Neural Networks for Thermochemical Conversion of Biomass;146
7.5.1;5.1. Introduction;146
7.5.2;5.2. Modeling Using Artificial Neural Networks;148
7.5.2.1;5.2.1. Fundamental Concepts;148
7.5.2.2;5.2.2. Network Architectures;149
7.5.2.3;5.2.3. Training an Artificial Neural Network;150
7.5.2.3.1;Least Mean Square Error Supervised Training;152
7.5.2.3.2;Activation Function;152
7.5.2.3.3;The Backpropagation Algorithm;153
7.5.2.3.4;Levenberg-Marquardt Algorithm;153
7.5.3;5.3. Development of Artificial Neural Network Models;153
7.5.3.1;5.3.1. Experimental Data Selection;154
7.5.3.2;5.3.2. Artificial Neural Networks Topology;154
7.5.3.3;5.3.3. Proposed ANN Model for Circulating Fluidized Bed Gasifiers;157
7.5.3.3.1;Sensitivity Analysis;159
7.5.3.4;5.3.4. Proposed ANN Model for Bubbling Fluidized Bed Gasifiers;162
7.5.3.4.1;Sensitivity Analysis;162
7.5.3.5;5.3.5. Comparison between the ANN Models and a Modified Equilibrium Model;162
7.5.4;5.4. Conclusions and Perspectives;165
7.5.5;References;168
7.6;Chapter 6: Thermochemical Biorefinery;170
7.6.1;6.1. Introduction;170
7.6.2;6.2. Biomass as a Sustainable Resource;171
7.6.3;6.3. Feedstocks for Thermochemical Biorefinery;172
7.6.4;6.4. Composition of Biomass;173
7.6.5;6.5. Biomass Conversion Methods;174
7.6.6;6.6. Existing Biorefinery Concepts;175
7.6.6.1;6.6.1. Comparison Between Petrorefinery and Biorefinery;175
7.6.6.2;6.6.2. Three-Phase Biorefinery;177
7.6.6.2.1;Whole-Crop Biorefinery;177
7.6.6.2.2;Green Biorefinery;178
7.6.6.2.3;Lignocellulose Feedstock Biorefinery;178
7.6.6.2.4;Integrated Biorefinery;178
7.6.6.2.5;Hybrid Biorefinery;179
7.6.6.3;6.6.3. Thermochemical Biorefinery;179
7.6.7;6.7. Products from Thermochemical Biorefinery;181
7.6.7.1;6.7.1. Synthetic Gas Followed by Fischer-Tropsch Reaction;182
7.6.7.2;6.7.2. Bio-oil;183
7.6.7.3;6.7.3. Biochar;184
7.6.8;6.8. Conclusions and Perspectives;184
7.6.9;Acknowledgments;185
7.6.10;References;185
8;Part II: Primary Processes ;188
8.1;Chapter 7. Fast Pyrolysis of Biomass;190
8.1.1;Recent Advances in Fast Pyrolysis Technology;190
8.1.2;7.1. Introduction;190
8.1.3;7.2. Chemistry of Fast Pyrolysis of Biomass;191
8.1.3.1;7.2.1. Cellulose;191
8.1.3.2;7.2.2. Hemicellulose;192
8.1.3.3;7.2.3. Lignin;193
8.1.4;7.3. Pyrolysis Reactors;194
8.1.4.1;7.3.1. Fixed Bed Reactor;195
8.1.4.2;7.3.2. Fluidized Bed Reactor;195
8.1.4.3;7.3.3. Circulating Fluidized Bed Reactor;195
8.1.4.4;7.3.4. Rotating Cone Reactor;197
8.1.4.5;7.3.5. Ablative Pyrolysis;197
8.1.4.6;7.3.6. Entrained Flow Reactor;197
8.1.4.7;7.3.7. Auger Reactor;198
8.1.4.8;7.3.8. PyRos Reactor;198
8.1.4.9;7.3.9. Plasma Pyrolysis;198
8.1.5;7.4. Recent Advances in Fast Pyrolysis Technology;200
8.1.5.1;7.4.1. Conventional Fast Pyrolysis;201
8.1.5.1.1;Production of Sugar-Rich Bio-oils via Fast Pyrolysis;206
8.1.5.1.2;Commercial-Scale Fast Pyrolysis Units;207
8.1.5.1.3;Conventional Fast Pyrolysis Conclusions;209
8.1.5.2;7.4.2. Catalytic Fast Pyrolysis;209
8.1.5.2.1;Direct Catalytic Fast Pyrolysis;209
8.1.5.2.2;Vapor Catalysis (Catalytic Treatment of Fast Pyrolysis Vapors);216
8.1.5.2.3;Hydropyrolysis;218
8.1.5.2.4;Catalytic Fast Pyrolysis Conclusions;219
8.1.6;7.5. Future Research and Development Challenges;220
8.1.7;References;220
8.2;Chapter 8: Biomass Gasification to Produce Syngas;226
8.2.1;8.1. Introduction;226
8.2.2;8.2. Biomass Gasifiers for Syngas Production;227
8.2.2.1;8.2.1. Fixed Bed Gasifiers;228
8.2.2.1.1;Downdraft Gasifier;229
8.2.2.1.2;Multistage Fixed Bed Gasifiers;230
8.2.2.2;8.2.2. Fluidized Bed Gasifiers;232
8.2.2.2.1;Bubbling Fluidized Bed Gasifier;232
8.2.2.2.2;Dual Fluidized Bed Gasifier;233
8.2.2.3;8.2.3. Advantages and Technical Challenges of the Different Gasification Technologies;234
8.2.3;8.3. Secondary Syngas Cleaning and Conditioning;236
8.2.3.1;8.3.1. Tar Elimination;237
8.2.3.2;8.3.2. Inorganic Compounds Elimination;240
8.2.3.3;8.3.3. Water-Gas Shift Reactors;242
8.2.3.4;8.3.4. Hydrogen Purification;243
8.2.4;8.4. Recent Trends Toward Process Intensification;245
8.2.4.1;8.4.1. Incorporation of Cleaning Up Multifunctional Systems into Existing Fluidized Gasification Reactors;246
8.2.4.2;8.4.2. Implementation of Specific Highly Reactive Gasification Media;250
8.2.4.3;8.4.3. Advanced Catalyst Integration Strategies;253
8.2.5;8.5. Conclusions and Perspectives;257
8.2.6;References;258
8.3;Chapter 9: Hydrothermal Gasification of Biomass;264
8.3.1;9.1. Hydrothermal Treatment Technologies;264
8.3.2;9.2. History;267
8.3.3;9.3. Reactions;268
8.3.4;9.4. Feedstocks;272
8.3.5;9.5. Catalysts;274
8.3.6;9.6. Process Design;275
8.3.7;9.7. Research and Development Topics;275
8.3.8;9.8. Conclusions and Perspectives;276
8.3.9;References;277
8.4;Chapter 10: Hydrothermal Liquefaction of Biomass;282
8.4.1;10.1. Introduction;282
8.4.2;10.2. First-Generation Biofuels;283
8.4.3;10.3. Second-generation biofuels;283
8.4.3.1;10.3.1. Lignocellulosic Biomass;283
8.4.3.1.1;Bonds Between Lignin and Carbohydrates: Lignin-Carbohydrate Complexes;284
8.4.4;10.4. Third-generation biofuels;285
8.4.5;10.5. Biomass Conversion Routes;285
8.4.5.1;10.5.1. Biochemical Conversion Routes;285
8.4.5.2;10.5.2. Acid Pretreatment versus HTU Pretreatment;285
8.4.5.3;10.5.3. Thermochemical Conversion Routes;286
8.4.6;10.6. Hydrothermal Liquefaction: Advantages Over Pyrolysis;287
8.4.7;10.7. Direct Liquefaction Processes;288
8.4.8;10.8. Hydrothermal Upgradation;289
8.4.9;10.9. Properties of Subcritical and Supercritical Water;290
8.4.9.1;10.9.1. Acid-Base Behavior of Subcritical Water Ionic Strength and pH Value;290
8.4.9.2;10.9.2. Dielectric Constant;291
8.4.9.3;10.9.3. Viscosity and Mass Transfer;291
8.4.10;10.10. Reactors;291
8.4.11;10.11. HTU Chemistry: Conceivable Reaction Pathways and Decomposition Mechanism in Hydrothermal Liquefaction;292
8.4.11.1;10.11.1. Lignin Depolymerization During Hydrothermal Liquefaction;292
8.4.11.2;10.11.2. Carbohydrate Conversion to HMF, Levullininc Acid and Other Value-Added Chemicals in Hydrothermal Media;292
8.4.12;10.12. Parameters (Physical and Chemical) Influencing Product Distribution During HTU of Biomass;294
8.4.12.1;10.12.1. Biomass Feedstock Type, Particle Size, and Biomass Substrate Concentration;294
8.4.12.2;10.12.2. Temperature;295
8.4.12.3;10.12.3. Heating Rate and Thermal gradients;296
8.4.12.4;10.12.4. Residence Time;296
8.4.12.5;10.12.5. Pressure;297
8.4.12.6;10.12.6. Solvent;297
8.4.12.7;10.12.7. Mass Ratio of Solvent to Biomass (S/B);298
8.4.12.8;10.12.8. Catalysts;298
8.4.13;10.13. Conclusions and Perspectives;298
8.4.14;Acknowledgments;299
8.4.15;References;299
8.5;Chapter 11: Carbonization of Biomass;306
8.5.1;11.1. Introduction;306
8.5.2;11.2. Biomass Carbonization Process Conditions;307
8.5.3;11.3. Carbonization Products and Their Physicochemical Properties;308
8.5.3.1;11.3.1. Charcoal;308
8.5.3.2;11.3.2. Torrefied Biomass;312
8.5.3.3;11.3.3. Activated Carbon;313
8.5.3.4;11.3.4. Biochar;313
8.5.4;11.4. Chemistry of the Carbonization Process;315
8.5.5;11.5. Relevant Feed Properties in Biomass Carbonization;317
8.5.5.1;11.5.1. Biological Composition of the Feedstock;318
8.5.5.2;11.5.2. Feedstock Moisture Content;318
8.5.5.3;11.5.3. Ash Content;319
8.5.5.4;11.5.4. Feedstock Morphology;320
8.5.6;11.6. Relevant Process Variables in Biomass Carbonization;320
8.5.6.1;11.6.1. Pyrolysis Temperature;321
8.5.6.2;11.6.2. Heat Transfer in Pyrolysis;322
8.5.6.3;11.6.3. Mass Transfer in Pyrolysis;324
8.5.6.4;11.6.4. Biomass Residence Time;325
8.5.6.5;11.6.5. Pressure;325
8.5.7;11.7. Carbonization Pyrolysis Systems and Reactors;326
8.5.7.1;11.7.1. Batch Carbonization (Slow Pyrolysis) Systems;326
8.5.7.1.1;Traditional Pit and Mound Kilns;326
8.5.7.1.2;Steel and Brick Kilns;327
8.5.7.1.3;Retorts;327
8.5.7.2;11.7.2. Continuous Carbonization (Slow Pyrolysis) Systems;329
8.5.7.2.1;Retorts;329
8.5.7.2.2;Multiple-Hearth Kilns;330
8.5.7.2.3;Rotary Kilns and Screw Pyrolyzers;331
8.5.8;11.8. Conclusions and Perspectives;333
8.5.9;References;334
8.6;Chapter 12: Hydrothermal Carbonization of Biomass;338
8.6.1;12.1. Introduction;338
8.6.2;12.2. HTC Chemistry;341
8.6.3;12.3. HTC Chemical Structure;344
8.6.4;12.4. Parameters Affecting the HTC Process;347
8.6.5;12.5. Nanostructuring and Functionalization;350
8.6.6;12.6. Applications of Hydrothermal Carbons;354
8.6.6.1;12.6.1. HTC as Electrodes in Secondary Batteries and Supercapacitors;354
8.6.6.2;12.6.2. HTC Coal as a Solid Fuel;357
8.6.7;12.7. Conclusions;359
8.6.8;References;360
9;Part III: Secondary Processes ;366
9.1;Chapter 13. Coprocessing of Bio-oil in Fluid Catalytic Cracking;368
9.1.1;13.1. General View About Coprocessing Bio-oils in Refineries;368
9.1.2;13.2. Bio-oil Production and Characterization;370
9.1.2.1;13.2.1. Biomass Pyrolysis;370
9.1.2.1.1;Reproducibility of Pyrolysis Processes in the Laboratory;371
9.1.2.2;13.2.2. Composition and Properties of the Liquid Products in the Pyrolysis of Lignocellulosic Biomass;372
9.1.3;13.3. Upgrading of Bio-oils Prior to Coprocessing;374
9.1.3.1;13.3.1. Composition of the Upgraded Bio-oil (Liquid from the Thermal Treatment);376
9.1.3.2;13.3.2. Physicochemical Properties of the Upgraded Bio-oil;377
9.1.4;13.4. Coprocessing Bio-oils and FCC Feedstocks;377
9.1.4.1;13.4.1. Conversion of Crude and Upgraded Bio-oil Over FCC Catalysts;378
9.1.4.1.1;Oxygenated Products;380
9.1.4.1.2;Hydrocarbon Products;381
9.1.4.1.3;Analysis of Coke Yields;383
9.1.4.2;13.4.2. Coprocessing Crude and Upgraded Bio-oil with VGO;383
9.1.4.2.1;Oxygenated Products;386
9.1.4.2.2;Composition of the Gasoline;387
9.1.4.2.3;Analysis of the Paraffins/Olefins Relationship as a Hydrogen Transfer Index;389
9.1.4.2.4;Coke Yield Analysis;389
9.1.5;13.5. Conclusions;390
9.1.6;References;391
9.2;Chapter 14: Biomass Gasification Integrated Fischer-Tropsch Synthesis: Perspectives, Opportunities and Challenges;396
9.2.1;14.1. Introduction;396
9.2.1.1;14.1.1. Concept of Biomass Gasification Integrated Fischer-Tropsch (BGIFT) Synthesis;405
9.2.2;14.2. Facets of FT Synthesis: Chemistry and Engineering;407
9.2.2.1;14.2.1. High-Temperature Mode (HTFT);408
9.2.2.2;14.2.2. Low-Temperature Mode (LTFT);408
9.2.2.3;14.2.3. Chemistry of FT Synthesis;408
9.2.2.4;14.2.4. Chemical Mechanisms for Fischer-Tropsch Synthesis Reaction;409
9.2.2.5;14.2.5. Models for the Profile of FT Products;412
9.2.2.6;14.2.6. Fischer Tropsch Catalysis;414
9.2.3;14.3. Reactors for FT Synthesis;418
9.2.4;14.4. Biomass Power in India;422
9.2.4.1;14.4.1. Biomass as a Coal Substitute;422
9.2.4.2;14.4.2. Biomass Resources and Utilization;423
9.2.5;14.5. Biomass Utilization: Technical Options;424
9.2.6;14.6. Technology for Biomass Gasification;425
9.2.6.1;14.6.1. Chemistry of Biomass Gasification;426
9.2.6.2;14.6.2. Biomass Pretreatment and Properties;428
9.2.6.3;14.6.3. Fixed Bed Gasification;429
9.2.6.4;14.6.4. Fluidized Bed Gasification;431
9.2.6.5;14.6.5. Entrained Flow Gasifier;432
9.2.6.6;14.6.6. Post-Treatment (Cleaning) of Producer Gas;435
9.2.6.6.1;Tar Removal;436
9.2.7;14.7. Coupling of Biomass Gasification and FT Synthesis for BGIFT (or BTL) Process;437
9.2.7.1;14.7.1. Perspectives and Challenges of the BGIFT Process;443
9.2.8;14.8. Conclusion;444
9.2.9;Acknowledgments;444
9.2.10;References;444
9.3;Chapter 15: Utilization of Supercritical Fluid for Catalytic Thermochemical Conversions of Woody-Biomass Related Compounds;450
9.3.1;15.1. Introduction;450
9.3.1.1;15.1.1. Utilization of Biomass as Auxiliary Resources;450
9.3.1.2;15.1.2. Supercritical Fluids as Reaction Media;451
9.3.2;15.2. Gasification of Lignin and Woody Biomass with Supported Ruthenium Catalysts in Supercritical Water;452
9.3.2.1;15.2.1. Gasification of Organosolv Lignin Over Supported Ruthenium Catalysts in Supercritical Water;452
9.3.2.2;15.2.2. Supercritical Gasification of Ethanol Production Residue from Wood;456
9.3.2.3;15.2.3. Effect of Sulfur on Supercritical Gasification with Supported Ruthenium Catalyst;458
9.3.3;15.3. Hydrogenation with Supported Metal Catalysis in Supercritical Carbon Dioxide;460
9.3.3.1;15.3.1. Hydrogenation of Alkylphenol Compounds with Supported Metal Catalysts;460
9.3.3.2;15.3.2. Hydrogenation with Supported Metal Catalysts in Supercritical Carbon Dioxide;460
9.3.3.3;15.3.3. Chemoselective Hydrogenation of Alkylphenols with Supported Rhodium Catalysts in Supercritical Carbon Dioxide;460
9.3.3.4;15.3.4. Carbon Dioxide Pressure Effect;463
9.3.3.5;15.3.5. Hydrogenation of 4-alkylphenols;463
9.3.4;15.4. Conclusions and Perspectives;465
9.3.5;References;465
9.4;Chapter 16: Thermochemical Valorization of Lignin;468
9.4.1;16.1. Introduction;468
9.4.2;16.2. Composition of Lignin;469
9.4.2.1;16.2.1. Structure and Linkages in Lignin;469
9.4.2.1.1;Carbon-Carbon (C-C) Linkages in Lignin;469
9.4.2.1.2; ß -5 Linkages in Lignin;470
9.4.2.2;16.2.2. Physical and Chemical Properties of Lignin;470
9.4.3;16.3. Separation of Lignin from Biomass;471
9.4.4;16.4. Thermochemical Conversion of Lignin;471
9.4.4.1;16.4.1. Pyrolysis;471
9.4.4.1.1;Catalytic Pyrolysis of Lignin;475
9.4.4.1.2;Lignin Pyrolysis Using Py-GC/MS;477
9.4.4.1.3;Hydropyrolysis;477
9.4.4.1.4;Upgradation of Lignin-Derived Bio-oil;478
9.4.4.2;16.4.2. Hydrothermal Upgradation;479
9.4.4.2.1;Hydrothermal Liquefaction;479
9.4.4.2.2;Lignin Decomposition in the Presence of Organic Solvents;480
9.4.4.2.3;Base-Catalyzed Depolymerization (BCD);481
9.4.4.3;16.4.3. Ionic Liquids;482
9.4.4.4;16.4.4. Lignin Conversion Using Nonconventional Sources of Energy;482
9.4.4.4.1;Microwave Pyrolysis;482
9.4.4.4.2;Ultrasonic Treatment;482
9.4.4.5;16.4.5. Lignin Gasification;483
9.4.4.5.1;Hydrothermal Gasification;483
9.4.4.6;16.4.6. Chemical Conversion of Lignin;484
9.4.4.6.1;Reduction;484
9.4.4.6.2;Electrocatalytic Hydrogenation;484
9.4.4.6.3;Oxidation;485
9.4.4.6.4;Wet Oxidation of Lignin;485
9.4.4.6.5;Alkylation/Dealkylation;485
9.4.4.6.6;Hydroxyalkylation;485
9.4.4.6.7;Functionalization of Hydroxyl Groups;486
9.4.5;16.5. Lignin to High-Value Products;486
9.4.6;16.6. Conclusions and Perspectives;486
9.4.7;Acknowledgments;487
9.4.8;References;487
10;Index;492

Leseproben

Chapter 2 Feedstock Suitability for Thermochemical Processes
Rupam Katakia,*; Rahul S. Chutiaa; Mridusmita Mishraa; Neonjyoti Bordoloia; Ruprekha Saikiaa; Thallada Bhaskarb    a Department of Energy, Tezpur University, Tezpur 784 028, India
b Bio-Fuels Division, CSIR-Indian Institute of Petroleum, Dehradun 248 005, India
* Corresponding author: [e-mail], [e-mail] Abstract
Biomass resources and their utilization offer a new paradigm of research in the changing world faced with diverse problems related to fossil fuel use for most of the energy needs of the society. This chapter discusses the unique characteristics of various biomass resources with varied composition and properties. Thermochemical biomass conversion methods offer greater flexibility in terms of usability of almost all types of biomass as feedstock and end product for further conversion to fuels and chemicals. However, thermochemical conversion efficiency is an area requiring attention from researchers, as certain biomass constituents and their inherent properties pose technological challenges during conversion. Various ways to mitigate these problems are being researched and are discussed in this chapter. Keywords: Feedstock Lignocellulosic biomass Thermochemical conversion Combustion Gasification Pyrolysis Torrefaction Leaching Biofuel 2.1 Introduction
The history of human civilization can be directly correlated to the progressive development of new energy sources and their associated conversion technologies. The principal energy sources of antiquity were all derived directly from the sun: human and animal muscle power, wood, flowing water, and wind. About 300 years ago, the industrial revolution began with stationary wind-powered and water-powered technologies, which were essentially replaced by fossil hydrocarbons-coal in the nineteenth century, oil since the twentieth century, and now, increasingly, natural gas. The global use of hydrocarbons for fuel by humans has increased nearly 800-fold since 1750 and about 12-fold in the twentieth century [1]. Along with this, emissions of anthropogenic greenhouse gases (GHG) to the atmosphere has also risen manifoldly, mostly from the production and use of energy, resulting in imbalance of natural C-cycle and creating numerous problems globally. There is new and stronger evidence that most of the global warming observed over the last 50 years is attributable to human activities [2]. To offset these deleterious effects, recent attention has been drawn to biofuels for their inherent C-neutral nature and many other beneficial concurrent socioeconomic gains. 2.1.1 Why Biofuel?
Rapid development in industrialization and motorization of the world has led to the steep rise for the demand of fossil fuels. On the other hand, growing use of fossil-based fuels and environmental concerns, particularly after the Earth Summit 1992 [3,4] has spurred an interest toward renewable resources and subsequent development of biomass, hydroelectric, solar, wave, geothermal, and wind power plants that can potentially limit the use of fossil fuels. In this regard, biomass represents an abundant carbon-neutral renewable resource that can be converted to solid, liquid, and gaseous biofuels using suitable conversion technologies. Biofuels are considered a carbon-neutral alternative to hydrocarbons in the transport sector, and this approach has triggered the scientific community to look forward to the conversion of parts of the global economy to a sustainable biobased economy with bioenergy, biofuels, and biobased products as its main pillars. This will, in turn, ensure a gradual transition from a petroleum-based economy to a diversified economy in which renewable plant biomass will become a significant feedstock for both fuel and chemical production. Thus, biomass and biofuel is poised for a bigger and more significant role in the near future. 2.1.2 Biobased Society and Economy
Biomass, solar (e.g., photovoltaic solar cells and solar heat collectors), wind (e.g., wind turbines), water (e.g., hydropower, tidal energy), and geothermal resources are all sources of renewable energy; however, biomass is the only renewable resource of carbon from which chemicals, materials, and fuels can be produced using appropriate conversion pathways. Renewable feedstocks supplied a significant portion of the global energy and chemical need before the beginning of petrochemical era. In the 1920s through1930s, the Chemurgy movement in the United States promoted the use of biomass as a source of chemicals with the belief that “anything that can be made from a hydrocarbon could be made from a carbohydrate.” The incentive was to find an economic way to use farm surpluses [1]. It is only in the relatively short period between 1920 and 1950 that mankind has witnessed the transition to a nonrenewable based economy that heavily depends on fossil resources. However, since the first oil crisis in the 1970s, decreasing resources, global warming, and environmental pollution associated with the use of fossil fuels have become growing motivations for the transition to renewable energy resources. Among the renewable resources, lignocellulosic biomass is particularly suited as an abundant, low-cost feedstock for production of biobased chemicals, fuels, and energy to substitute fossil resources. A drawback of the growing consumption of biomass for energy is the increase in price for the biomass feedstock. This conflicts with the need of biorefineries for low-cost raw materials. 2.2 Processes for the Conversion of Biomass into Various Products in a Biorefinery
Various processes can be used to convert biomass to energy. The biomass can be burned, transformed into a fuel gas through partial combustion, transformed into a biogas through biochemical processes, converted to bioalcohol through fermentation, converted to biodiesel, pyrolyzed into a bio-oil, or transformed into a syngas from which chemicals and fuels can be synthesized. Figure 2.1 illustrates the various processes to transform a variety of biomass feedstock into liquid hydrocarbons. Figure 2.1 A schematic of various processes to transform a variety of biomass feedstock into liquid hydrocarbons. 2.3 Thermochemical Conversion
In contrast to other renewable sources, which give heat and power, biomass is the only source that can be converted to liquid, solid, and gaseous fuels applying suitable conversion technologies. Wood and other biomass can be treated in a number of different ways to provide such fuels. There are certain technologies for converting feedstocks into commercially viable liquid transportation fuels, as well as bioproducts and biopower. Basically, such methods are divided into biological (anaerobic digestion and fermentation) and thermal. The diversity of the biomass resource requires the development of multiple conversion technologies that can efficiently deal with the broad range of feedstock materials, as well as their physical and chemical characteristics. The combined uses of technologies from both areas (hybrid processing) may also offer a tremendous opportunity for optimizing the conversion of biomass into a variety of different fuels, chemicals, and energy products. The different thermochemical routes of conversion of biomass and their products are shown in Figure 2.2. Figure 2.2 Thermochemical conversion processes and end products. As shown in Figure 2.2, direct combustion of biomass provides heat for steam production and, hence, electricity can be generated. Gasification also provides a fuel gas that can be combusted to generate heat or used in an engine or turbine for electricity generation. The third alternative is fast pyrolysis, which provides a liquid fuel that can substitute for fuel oil in any static heating or electricity generation application. The advantage of fast pyrolysis is that it can directly produce a liquid fuel, which can be readily stored and transported with certain modifications, and it is beneficial when biomass resources are remote from the location where the energy is required. Also, the pyrolysis process is the only renewable energy conversion technique that can convert various types of biomass into solid, liquid, and gaseous fuels as shown in Figure 2.3. However, the product distribution in the pyrolysis process depends greatly on various process parameters; namely, heating rate, final temperature, vapor residence time, and pyrolysis environment. Slow pyrolysis, or carbonization, is well known and is an established process for making charcoal in developing countries. Conversely, bio-oil maximization in the final product distribution of pyrolysis is the aim of some current research agendas in the global thermochemical community. Although research has achieved a desired target, successful commercial application is still a far cry away for several reasons. One of the nonprocess parameters and a major agent affecting its commercialization is availability of feedstocks, their varied compositions, and other logistic issues associated with it. Figure 2.3 Product distribution of pyrolysis and its possible uses. Feedstocks for Thermochemical...