Biofuels: Biotechnology, Chemistry, and Sustainable Development Book

Preface     xi
Author     xix
Historical Development of Bioethanol as a Fuel     1
Ethanol from Neolithic Times     1
Ethanol and Automobiles, from Henry Ford to Brazil     4
Ethanol as a Transportation Fuel and Additive: Economics and Achievements     11
Starch as a Carbon Substrate for Bioethanol Production     17
The Promise of Lignocellulosic Biomass     26
Thermodynamic and Environmental Aspects of Ethanol as a Biofuel     33
Net energy balance     33
Effects on emissions of greenhouse gases and other pollutants     40
Ethanol as a First-Generation Biofuel: Present Status and Future Prospects     42
References     44
Chemistry, Biochemistry, and Microbiology of Lignocellulosic Biomass     49
Biomass as an Energy Source: Traditional and Modern Views     49
"Slow Combustion" - Microbial Bioenergetics     52
Structural and Industrial Chemistry of Lignocellulosic Biomass     56
Lignocellulose as a chemical resource     56
Physical and chemical pretreatment of lignocellulosic biomass     57
Biological pretreatments     63
Acid hydrolysis to saccharify pretreated lignocellulosic biomass     64
Cellulases:Biochemistry, Molecular Biology, and Biotechnology     66
Enzymology of cellulose degradation by cellulases     66
Cellulases in lignocellulosic feedstock processing     70
Molecular biology and biotechnology of cellulase production     71
Hemicellulases: New Horizons in Energy Biotechnology     78
A multiplicity of hemicellulases     78
Hemicellulases in the processing of lignocellulosic biomass     80
Lignin-Degrading Enzymes as Aids in Saccharification     81
Commercial Choices of Lignocellulosic Feedstocks for Bioethanol Production     81
Biotechnology and Platform Technologies for Lignocellulosic Ethanol     86
References     86
Biotechnology of Bioethanol Production from Lignocellulosic Feedstocks     95
Traditional Ethanologenic Microbes     95
Yeasts     96
Bacteria     102
Metabolic Engineering of Novel Ethanologens     104
Increased pentose utilization by ethanologenic yeasts by genetic manipulation with yeast genes for xylose metabolism via xylitol     104
Increased pentose utilization by ethanologenic yeasts by genetic manipulation with genes for xylose isomerization     111
Engineering arabinose utilization by ethanologenic yeasts     112
Comparison of industrial and laboratory yeast strains for ethanol production     114
Improved ethanol production by naturally pentose-utilizing yeasts     118
Assembling Gene Arrays in Bacteria for Ethanol Production     120
Metabolic routes in bacteria for sugar metabolism and ethanol formation     120
Genetic and metabolic engineering of bacteria for bioethanol production     121
Candidate bacterial strains for commercial ethanol production in 2007     133
Extrapolating Trends for Research with Yeasts and Bacteria for Bioethanol Production     135
"Traditional" microbial ethanologens     135
"Designer" cells and synthetic organisms     141
References     142
Biochemical Engineering and Bioprocess Management for Fuel Ethanol     157
The Iogen Corporation Process as a Template and Paradigm     157
Biomass Substrate Provision and Pretreatment     160
Wheat straw - new approaches to complete saccharification     161
Switchgrass     162
Corn stover     164
Softwoods     167
Sugarcane bagasse     170
Other large-scale agricultural and forestry biomass feedstocks     171
Fermentation Media and the "Very High Gravity" Concept     172
Fermentation media for bioethanol production     173
Highly concentrated media developed for alcohol fermentations     174
Fermentor Design and Novel Fermentor Technologies     179
Continuous fermentations for ethanol production     179
Fed-batch fermentations     184
Immobilized yeast and bacterial cell production designs     185
Contamination events and buildup in fuel ethanol plants     187
Simultaneous Saccharification and Fermentation and Direct Microbial Conversion     189
Downstream Processing and By-Products     194
Ethanol recovery from fermented broths     194
Continuous ethanol recovery from fermentors     195
Solid by-products from ethanol fermentations     196
Genetic Manipulation of Plants for Bioethanol Production     199
Engineering resistance traits for biotic and abiotic stresses     199
Bioengineering increased crop yield     200
Optimizing traits for energy crops intended for biofuel production     203
Genetic engineering of dual-use food plants and dedicated energy crops     205
A Decade of Lignocellulosic Bioprocess Development: Stagnation or Consolidation?     206
References     211
The Economics of Bioethanol     227
Bioethanol Market Forces in 2007      227
The impact of oil prices on the "future" of biofuels after 1980     227
Production price, taxation, and incentives in the market economy     228
Cost Models for Bioethanol Production     230
Early benchmarking studies of corn and lignocellulosic ethanol in the United States     231
Corn ethanol in the 1980s: rising industrial ethanol prices and the development of the "incentive" culture     238
Western Europe in the mid-1980s: assessments of biofuels programs made at a time of falling real oil prices     239
Brazilian sugarcane ethanol in 1985: after the first decade of the Proalcool Program to substitute for imported oil     242
Economics of U.S. corn and biomass ethanol economics in the mid-1990s     243
Lignocellulosic ethanol in the mid-1990s: the view from Sweden     244
Subsequent assessments of lignocellulosic ethanol in Europe and the United States     246
Pilot Plant and Industrial Extrapolations for Lignocellulosic Ethanol     251
Near-future projections for bioethanol production costs     251
Short- to medium-term technical process improvements with their anticipated economic impacts     253
Bioprocess economics: a Chinese perspective     257
Delivering Biomass Substrates for Bioethanol Production: The Economics of a New Industry      258
Upstream factors: biomass collection and delivery     258
Modeling ethanol distribution from production to the end user     259
Sustainable Development and Bioethanol Production     260
Definitions and semantics     260
Global and local sustainable biomass sources and production     261
Sustainability of sugar-derived ethanol in Brazil     264
Impact of fuel economy on ethanol demand for gasoline blends     269
Scraping the Barrel: an Emerging Reliance on Biofuels and Biobased Products?     271
References     279
Diversifying the Biofuels Portfolio     285
Biodiesel: Chemistry and Production Processes     285
Vegetable oils and chemically processed biofuels     285
Biodiesel composition and production processes     287
Biodiesel economics     293
Energetics of biodiesel production and effects on greenhouse gas emissions     295
Issues of ecotoxicity and sustainability with expanding biodiesel production     299
Fischer-Tropsch Diesel: Chemical Biomass-to-Liquid Fuel Transformations     301
The renascence of an old chemistry for biomass-based fuels?     301
Economics and environmental impacts of FT diesel     303
Methanol, Glycerol, Butanol, and Mixed-Product "Solvents"     305
Methanol: thermochemical and biological routes     305
Glycerol: fermentation and chemical synthesis routes     307
ABE (acetone, butanol, and ethanol) and "biobutanol"     309
Advanced Biofuels: A 30-Year Technology Train     311
References     314
Radical Options for the Development of Biofuels     321
Biodiesel from Microalgae and Microbes     321
Marine and aquatic biotechnology     321
"Microdiesel"     324
Chemical Routes for the Production of Monooxygenated C6 Liquid Fuels from Biomass Carbohydrates     324
Biohydrogen     325
The hydrogen economy and fuel cell technologies     325
Bioproduction of gases: methane and H[subscript 2] as products of anaerobic digestion     328
Production of H[subscript 2] by photosynthetic organisms     334
Emergence of the hydrogen economy     341
Microbial Fuel Cells: Eliminating the Middlemen of Energy Carriers     343
Biofuels or a Biobased Commodity Chemical Industry?     346
References     347
Biofuels as Products of Integrated Bioprocesses     353
The Biorefinery Concept     353
Biomass Gasification as a Biorefinery Entry Point      356
Fermentation Biofuels as Biorefinery Pivotal Products     357
Succinic acid     361
Xylitol and "rare" sugars as fine chemicals     364
Glycerol - A biorefinery model based on biodiesel     367
The Strategic Integration of Biorefineries with the Twenty-First Century Fermentation Industry     369
Postscript: What Biotechnology Could Bring About by 2030     372
Chicago, Illinois, October 16-18, 2007     373
Biotechnology and strategic energy targets beyond 2020     375
Do biofuels need - rather than biotechnology - the petrochemical industry?     377
References     379
Index     385