9.2.3 Ethanol Purification and Product Separation........... 236
9.2.4 Byproducts and Coproducts ..................................... 237
9.2.5 Environmental Implications..................................... 237
9.3 Corn to Ethanol Process Technologies.................................. 237
9.3.1 Wet Milling Technology for Conversion of
Corn to Ethanol ........................................................ 237
9.3.2 Dry Milling Corn-to-Ethanol Process ..................... 239
9.4 Cellulosic Ethanol.................................................................. 241
9.4.1 Pretreatment .............................................................244
9.4.1.1 Rapid Steam Hydrolysis............................ 245
9.4.1.2 Dilute Acid Prehydrolysis......................... 245
9.4.1.3 Organosolv Pretreatment .......................... 245
9.4.1.4 Combined RASH and Organosolv
Pretreatment..............................................246
9.4.1.5 Ionic Liquid Pretreatment......................... 247
9.4.2 Hydrolysis................................................................. 247
9.4.2.1 Acid or Chemical Hydrolysis.................... 247
9.4.2.2 Enzymatic Hydrolysis...............................248
9.4.2.3 Mechanism of Cellulose Hydrolysis ......... 250
9.4.3 Fermentation............................................................. 251
9.4.3.1 Separate Hydrolysis and Fermentation ..... 251
9.4.3.2 Simultaneous Saccharification and
Fermentation ............................................. 252
9.4.3.3 Comparison between SSF and SHF
Processes................................................... 253
9.4.3.4 xylose Fermentation ................................. 253
9.4.4 Ethanol Extraction during Fermentation.................. 254
9.4.5 Lignin Conversion .................................................... 255
9.4.6 Coproducts of Cellulosic Ethanol Technology......... 255
9.4.7 Future Directions for Cellulosic Ethanol ................. 256
9.5 Fermentation of Sugar to Isobutanol ..................................... 256
References ........................................................................................ 257
Chapter 10 Fuel Production by Supercritical Water ........................................... 261
10.1 Introduction ........................................................................... 261
10.2 Properties of SCW................................................................. 262
10.3 Role of SCW in Chemical Synthesis..................................... 265
10.4 Oxidation in SCW .................................................................266
10.4.1 Catalysts for SCWO ................................................. 268
10.5 Decomposition and Extraction of Materials by SCW ........... 268
10.6 Gasification in SCW .............................................................. 272
10.7 Reforming in SCW................................................................ 277
10.7.1 Liquid Fuels.............................................................. 277
10.7.2 Biomass .................................................................... 279
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Contents
9.2.4 Byproducts and Coproducts ..................................... 237
9.2.5 Environmental Implications..................................... 237
9.3 Corn to Ethanol Process Technologies.................................. 237
9.3.1 Wet Milling Technology for Conversion of
Corn to Ethanol ........................................................ 237
9.3.2 Dry Milling Corn-to-Ethanol Process ..................... 239
9.4 Cellulosic Ethanol.................................................................. 241
9.4.1 Pretreatment .............................................................244
9.4.1.1 Rapid Steam Hydrolysis............................ 245
9.4.1.2 Dilute Acid Prehydrolysis......................... 245
9.4.1.3 Organosolv Pretreatment .......................... 245
9.4.1.4 Combined RASH and Organosolv
Pretreatment..............................................246
9.4.1.5 Ionic Liquid Pretreatment......................... 247
9.4.2 Hydrolysis................................................................. 247
9.4.2.1 Acid or Chemical Hydrolysis.................... 247
9.4.2.2 Enzymatic Hydrolysis...............................248
9.4.2.3 Mechanism of Cellulose Hydrolysis ......... 250
9.4.3 Fermentation............................................................. 251
9.4.3.1 Separate Hydrolysis and Fermentation ..... 251
9.4.3.2 Simultaneous Saccharification and
Fermentation ............................................. 252
9.4.3.3 Comparison between SSF and SHF
Processes................................................... 253
9.4.3.4 xylose Fermentation ................................. 253
9.4.4 Ethanol Extraction during Fermentation.................. 254
9.4.5 Lignin Conversion .................................................... 255
9.4.6 Coproducts of Cellulosic Ethanol Technology......... 255
9.4.7 Future Directions for Cellulosic Ethanol ................. 256
9.5 Fermentation of Sugar to Isobutanol ..................................... 256
References ........................................................................................ 257
Chapter 10 Fuel Production by Supercritical Water ........................................... 261
10.1 Introduction ........................................................................... 261
10.2 Properties of SCW................................................................. 262
10.3 Role of SCW in Chemical Synthesis..................................... 265
10.4 Oxidation in SCW .................................................................266
10.4.1 Catalysts for SCWO ................................................. 268
10.5 Decomposition and Extraction of Materials by SCW ........... 268
10.6 Gasification in SCW .............................................................. 272
10.7 Reforming in SCW................................................................ 277
10.7.1 Liquid Fuels.............................................................. 277
10.7.2 Biomass .................................................................... 279
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Contents