13.1 Introduction.............................................................................................. 394
13.2 First-Generation Biofuels ........................................................................ 394
13.3 Second Generation Biofuels.................................................................... 395
13.4 Biological Conversion.............................................................................. 396
13.4.1 Bioethanol ................................................................................... 396
13.4.1.1 Chemical Hydrolysis ................................................ 397
13.4.1.2 Enzymatic Hydrolysis .............................................. 398
13.4.1.3 Bioethanol Properties ............................................... 398
13.5 Thermochemical Conversion ................................................................. 399
13.5.1 Gasification .................................................................................400
13.5.1.1 Fixed-Bed Gasifiers ...................................................400
13.5.1.2 Fluidized-Bed Gasifiers............................................ 402
13.5.1.3 Entrained Gasifiers ................................................... 403
13.5.2 Biohydrogen................................................................................405
13.5.2.1 Gasification Process ..................................................405
13.5.2.2 Supercritical Water Gasification (SCWG) .............. 406
13.5.2.3 Fermentation Process ............................................... 406
13.5.2.4 Applications ............................................................... 407
13.5.3 Fischer–Tropsch Diesel ............................................................. 407
13.5.4 Dimethyl Ether ........................................................................... 410
13.5.4.1 DME from Methanol ................................................ 411
13.5.4.2 DME from Coal/Biomass......................................... 412
13.5.4.3 Properties of DME .................................................... 412
13.6 Algae Biodiesel......................................................................................... 414
13.6.1 Cultivation of Algae................................................................... 414
13.6.2 Commercialization .................................................................... 416
13.6.3 Advantages of Algae Biofuel .................................................... 417
13.7 Comparison between First and Second-Generation Biofuels ........... 417
13.8 Challenges for Future Biofuels .............................................................. 417
References............................................................................................................. 418
13
Future Fuels
Arumugam Sakunthalai Ramadhas
CONTENTS
393
13.2 First-Generation Biofuels ........................................................................ 394
13.3 Second Generation Biofuels.................................................................... 395
13.4 Biological Conversion.............................................................................. 396
13.4.1 Bioethanol ................................................................................... 396
13.4.1.1 Chemical Hydrolysis ................................................ 397
13.4.1.2 Enzymatic Hydrolysis .............................................. 398
13.4.1.3 Bioethanol Properties ............................................... 398
13.5 Thermochemical Conversion ................................................................. 399
13.5.1 Gasification .................................................................................400
13.5.1.1 Fixed-Bed Gasifiers ...................................................400
13.5.1.2 Fluidized-Bed Gasifiers............................................ 402
13.5.1.3 Entrained Gasifiers ................................................... 403
13.5.2 Biohydrogen................................................................................405
13.5.2.1 Gasification Process ..................................................405
13.5.2.2 Supercritical Water Gasification (SCWG) .............. 406
13.5.2.3 Fermentation Process ............................................... 406
13.5.2.4 Applications ............................................................... 407
13.5.3 Fischer–Tropsch Diesel ............................................................. 407
13.5.4 Dimethyl Ether ........................................................................... 410
13.5.4.1 DME from Methanol ................................................ 411
13.5.4.2 DME from Coal/Biomass......................................... 412
13.5.4.3 Properties of DME .................................................... 412
13.6 Algae Biodiesel......................................................................................... 414
13.6.1 Cultivation of Algae................................................................... 414
13.6.2 Commercialization .................................................................... 416
13.6.3 Advantages of Algae Biofuel .................................................... 417
13.7 Comparison between First and Second-Generation Biofuels ........... 417
13.8 Challenges for Future Biofuels .............................................................. 417
References............................................................................................................. 418
13
Future Fuels
Arumugam Sakunthalai Ramadhas
CONTENTS
393