Preface ...................................................... XIII
1 Introduction to Biofuels and Bioenergy ....................... 1
1.1 Definition .............................................. 1
1.2 Global Energy Outlook ................................... 2
1.3 Sustainability .......................................... 8
1.4 Biomass Feedstocks ...................................... 9
1.5 Processes and Technologies ............................. 12
1.5.1 Feedstock Preparation and Pretreatments ......... 12
1.5.2 Chemical and Biochemical Reactions .............. 13
1.5.3 Heat Transfer Enhancement and Management ........ 13
1.5.4 Downstream Processing of Raw or Intermediate
Biofuel Products ................................ 13
1.5.5 Energy Integration and Energy Efficiency
Enhancement ..................................... 14
1.5.6 Product Purification and Separation ............. 14
1.6 Environment and Ecology ................................ 14
References .................................................. 15
2 Crop Oils, Biodiesel, and Algae Fuels ....................... 17
2.1 Vegetable Oils ......................................... 17
2.1.1 Background ...................................... 17
2.1.2 Production and Use of Vegetable Oils ............ 19
2.1.3 Extraction of Vegetable Oils .................... 19
2.1.4 Composition of Vegetable Oils ................... 20
2.1.5 Use of Vegetable Oil as Alternative Diesel
Fuel ............................................ 21
2.1.6 Use of Vegetable Oil in Direct Heating .......... 24
2.1.7 Use of Vegetable Oil for Combined Heat and
Power (CHP) ..................................... 26
2.1.8 Use of Vegetable Oil for Biodiesel Manufacture .. 26
2.2 Algae Oil Extraction of Straight Vegetable Oil ......... 27
2.2.1 Introduction .................................... 27
2.2.2 Microalgae and Growth ........................... 28
2.2.3 Algae Harvesting ................................ 28
2.2.3.1 Microscreening Harvesting of Algae ..... 29
2.2.3.2 Algae Harvesting by Flocculation ....... 31
2.2.3.3 Algae Harvesting by Centrifugation ..... 31
2.2.4 Algae Oil Extraction ............................ 32
2.2.5 By-Product Utilization .......................... 40
2.3 Manufacture of Biodiesel ............................... 40
2.3.1 Historical Background of Biodiesel Manufacture .. 41
2.3.2 Transesterification Process for Biodiesel
Manufacture ..................................... 42
2.3.3 Properties of Biodiesel ......................... 44
2.3.4 Prospects and Economics ......................... 47
References .................................................. 48
3 Ethanol from Corn ........................................... 53
3.1 Fuel Ethanol from Corn ................................. 53
3.2 Corn Ethanol as Oxygenated Fuel ........................ 59
3.2.1 Industrial Significance of Grain Ethanol ........ 59
3.2.2 Clean Air Act Amendments of 1990 ................ 60
3.2.3 Energy Independence and Security Act (EISA) of
2007 ............................................ 61
3.2.4 Net Energy Balance of Corn Ethanol Production ... 62
3.2.5 Food versus Fuel ................................ 63
3.2.6 Corn Ethanol Production Technologies ............ 64
3.3 Chemistry of Ethanol Fermentation ...................... 69
3.3.1 Sugar Content of Biological Materials ........... 69
3.3.2 Conversion of Sugars to Ethanol ................. 70
3.4 Corn-to-Ethanol Process Technology ..................... 72
3.4.1 Wet Milling Corn Ethanol Technology ............. 72
3.4.2 Dry Milling Corn Ethanol Process ................ 76
3.4.3 Industrial Cleaning of Ethanol Plant ............ 80
3.5 By-Products/Coproducts of Corn Ethanol ................. 81
3.6 Ethanol as Oxygenated and Renewable Fuel ............... 82
3.7 Ethanol Vehicles ....................................... 85
3.8 Other Uses of Ethanol .................................. 87
References .................................................. 89
4 Ethanol from Lignocellulose ................................. 93
4.1 Lignocellulose and Its Utilization ..................... 93
4.1.1 Lignocellulose .................................. 93
4.1.2 Cellulose Degradation, Conversion, and
Utilization ..................................... 96
4.2 Lignocellulose Conversion .............................. 98
4.2.1 Ethanol ......................................... 98
4.2.2 Sources for Fermentable Sugars ................. 103
4.3 Historical Perspective of Alcohol Fermentation
Technology ............................................ 104
4.4 Agricultural Lignocellulosic Feedstock ................ 107
4.5 Cellulosic Ethanol Technology ......................... 110
4.5.1 Acid or Chemical Hydrolysis .................... 110
4.5.2 Enzymatic Hydrolysis ........................... 113
4.5.3 Enzymatic Processes ............................ 115
4.5.4 Lignin Conversion .............................. 133
4.5.5 Coproducts of Cellulosic Ethanol Technology .... 136
4.6 Energy Balance for Ethanol Production from Biomass .... 136
4.7 Process Economics and Strategic Direction ............. 139
References ................................................. 140
5 Fast Pyrolysis and Gasification of Biomass ................. 147
5.1 Biomass and Its Utilization ......................... 147
5.1.1 Definition of the Term Biomass ................. 147
5.1.2 Renewability and Sustainability of Biomass
Feedstock ...................................... 148
5.1.3 Woody Biomass and Its Utilization .............. 149
5.2 Analysis and Composition of Biomass ................... 151
5.2.1 Similarities and Differences between Biomass
and Coal as Feedstock .......................... 151
5.2.2 Analysis of Biomass ............................ 155
5.2.3 Thermochemical Conversion of Biomass ........... 156
5.2.4 Analysis of Biomass Feedstock and Product
Compositions ................................... 158
5.3 Chemistry of Biomass Gasification ..................... 160
5.3.1 Chemical Reactions Taking Place during
Biomass Gasification ........................... 161
5.3.2 Biosyngas ...................................... 172
5.3.3 Tar Formation .................................. 173
5.4 Fast Pyrolysis of Biomass ............................. 175
5.5 Biomass Gasification Processes ........................ 186
5.6 Utilization of Biomass Synthesis Gas .................. 196
References ................................................. 198
6 Conversion of Waste to Biofuels, Bioproducts, and
Bioenergy .................................................. 205
6.1 Introduction .......................................... 205
6.2 Types of Waste and Their Distributions ................ 206
6.3 Strategies for Waste Management ....................... 208
6.4 Waste Preparation and Pretreatment for Conversion ..... 210
6.5 Technologies for Conversion of Waste to Energy and
Products .............................................. 211
6.5.1 Combustion/Incineration ........................ 213
6.5.2 Gasification ................................... 217
6.5.3 Pyrolysis ...................................... 220
6.5.4 Plasma Technology .............................. 221
6.5.5 Liquefaction ................................... 226
6.5.6 Supercritical Technology ....................... 230
6.5.7 Transesterification ............................ 234
6.5.8 Anaerobic Digestion ............................ 236
6.5.9 Fermentation ................................... 238
6.5.10 Products Upgrading Technologies ................ 241
6.6 Economic and Environmental Issues Related to Waste
Conversion ............................................ 241
6.7 Future of the Waste Industry .......................... 242
References ................................................. 243
7 Mixed Feedstock ............................................ 251
7.1 Introduction .......................................... 251
7.2 Advantages and Disadvantages of Mixed Feedstock ....... 255
7.3 Transportation, Storage, and Pretreatment ............. 258
7.3.1 Pretreatment ................................... 258
7.4 Gasification Technologies ............................. 265
7.4.1 Literature Studies ............................. 265
7.4.2 Reactor Technology ............................. 267
7.4.3 Handling of Product Streams .................... 273
7.4.4 Process Configurations for Gasification
Technologies ................................... 276
7.4.5 Industrial Processes ........................... 279
7.5 Liquefaction Technologies ............................. 284
7.5.1 Direct Liquefaction ............................ 285
7.5.2 Pyrolysis ...................................... 286
7.5.3 Supercritical Extraction ....................... 287
7.6 Summary ............................................... 288
7.7 Future of Mixed Feedstock ............................. 291
References ................................................. 292
Index ......................................................... 303
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