Plant Biomass Conversion

A whole host of motivations are driving the development of the “renewables” industry— ranging from the desire to develop sustainable energy resources to the reduction of dangerous greenhouse gases that contribute to global warming. All energy utilized on the earth is ultimately derived from the sun through photosynthesis—the only truly renewable commodity. As concerns regarding increasing energy prices, global warming and renewable resources continue to grow, so has scientific discovery into agricultural biomass conversion. Plant Biomass Conversion addresses both the development of plant biomass and conversion technology, in addition to issues surrounding biomass conversion, such as the affect on water resources and soil sustainability. This book also offers a brief overview of the current status of the industry and examples of production plants being used in current biomass conversion efforts.

Table of Contents:
Contributors xi Preface xiii 1 The Bioeconomy: A New Era of Products Derived from Renewable Plant-Based Feedstocks 3 Peter Nelson, Elizabeth Hood, and Randall Powell 1.1 Introduction 3 1.2 Market Opportunity for Biofuels and Biobased Products 5 1.3 Feedstocks 6 1.3.1 Biobased Feedstock Availability and Issues 6 1.3.2 Characterization of Lignocellulosic Feedstocks 8 1.3.3 The Role of Agricultural Biotechnology 9 1.3.4 Biomass Agricultural Equipment Development 11 1.4 The Biochemical Technology Platform 11 1.5 Investment and Major Players 12 1.6 The Role of the Farmer 14 1.7 Opportunities for Rural Development 16 1.8 Environmental Benefits 17 1.9 Economic Comparison of the Biochemical and Thermochemical Technology Platforms 17 1.10 Conclusions and Future Prospects 18 References 19 2 Agricultural Residues 21 James Hettenhaus 2.1 Introduction 21 2.1.1 Key Issues 22 2.2 Feedstock Supply 23 2.2.1 Residue Markets 26 2.2.2 Harvest Window 27 2.2.3 Residue Removal 27 2.2.4 Residue Management 28 2.2.5 Ag Equipment Needs 29 2.2.6 Operating Costs 33 2.2.7 Residue Nutrient Value 33 2.2.8 Land for Energy Crops 33 2.2.9 Farmer Outlook 34 2.2.10 Crop Research and Development 34 2.3 Feedstock Logistics 34 2.3.1 Bulk Density 35 2.3.2 Storage 36 2.3.3 Regional Biomass Processing Centers 43 2.4 Conclusion 48 Endnotes 49 References 49 3 Growing Systems for Traditional and New Forest-Based Materials 51 Randall Rousseau, Janet Hawkes, Shijie Liu, and Tom Amidon 3.1 Introduction 51 3.2 Natural Regeneration 54 3.3 Overall Growing Systems 54 3.3.1 The Beginnings of Biomass Plantation Production 55 3.3.2 Short Rotation Woody Crops 56 3.3.3 Other Types of Hardwood Plantations 59 3.3.4 Southern Pine 61 3.4 New Genetic Tools 62 3.5 Agroforestry 63 3.6 Products from Woody Biomass 67 3.6.1 Hemicellulosic Products 69 3.6.2 Biorefineries Using Woody Biomass 71 3.6.3 Hot-Water Extraction of Hemicellulose 73 3.6.4 Wood Extracts: Processing and Conversion 75 3.6.5 Residual Solid Wood Biomass: Processing and Conversion of the wood mass after extraction, an example 78 3.7 Summary 78 References 78 4 Dedicated Herbaceous Energy Crops 85 Keat (Thomas) Teoh, Shivakumar Pattada Devaiah, Deborah Vicuna Requesens, and Elizabeth E. Hood 4.1 Introduction 85 4.2 Miscanthus 85 4.2.1 Characteristics That Make Miscanthus a Potential Biomass Crop 87 4.2.2 Agronomy 87 4.3 Sweet Sorghum 90 4.3.1 Biology of Sweet Sorghum 92 4.3.2 Production 92 4.3.3 Potential Yields 94 4.3.4 Economic and Environmental Advantages of Sweet Sorghum 94 4.3.5 Production Challenges 96 4.4 Switchgrass 97 4.4.1 Physiology 97 4.4.2 Switchgrass Ecotypes 98 4.4.3 Advantages 98 4.4.4 Disadvantages 99 4.4.5 Yields 100 4.4.6 Switchgrass as a Bioenergy Crop 101 4.5 Conclusions and Future Prospects 101 References 104 5 Municipal Solid Waste as a Biomass Feedstock 109 David J. Webster 5.1 Introduction 109 5.2 Definitions 110 5.2.1 Second-Generation Conversion Technologies for Biofuels 110 5.3 Disposal Infrastructure and Transfer Stations 110 5.3.1 Collection Practices 112 5.3.2 Cost Parameters 112 5.4 Waste Generation 113 5.5 Waste Characterization 114 5.5.1 Composition of Generated MSW Prior to Disposal or Processing 114 5.5.2 Landfilled Waste Compared to Waste Generation 115 5.5.3 Water in MSW 116 5.5.4 Heavy Metals in MSW 117 5.6 Preparing MSW for Conversion Processing—Mixed Waste Material Recovery Facilities (MRFs) 119 5.6.1 Presorting 121 5.6.2 Mechanical Sorting Operations 122 5.6.3 Manual Sorting Operations 123 5.6.4 Recovery Rates of the MRF System 123 5.7 Cellulosic Content of MSW 124 5.7.1 Glucose and Ethanol Yields from MSW 124 5.8 Framing the Potential 125 References 126 6 Water Sustainability in Biomass Cropping Systems 129 Jennifer L. Bouldin and Rodney E. Wright 6.1 Introduction 129 6.2 Water Use in Bioenergy Production 130 6.3 Water Quality Issues in Bioenergy Crops 133 6.3.1 AGNPS Watershed Model 135 6.3.2 Water Quality and the Gulf Hypoxic Zone 138 6.4 Conclusions—Water Quantity and Quality 138 References 139 7 Soil Sustainability Issues in Energy Crop Production 143 V. Steven Green 7.1 Soil Sustainability Concepts 143 7.2 Bioenergy Crops and Soil Sustainability 145 7.2.1 Crop Residues 145 7.2.2 Dedicated Energy Crops 146 7.3 Resource Use in Biomass Production 149 7.3.1 Water and Soil 149 7.3.2 Land Use 150 7.4 Soil Sustainability Solutions 150 7.5 Conclusion 154 References 154 8 Fermentation Organisms for 5- and 6-Carbon Sugars 157 Nicholas Dufour, Jeffrey Swana, and Reeta P. Rao 8.1 Introduction 157 8.2 Fermentation 159 8.3 Metabolic Pathways 160 8.4 Fermenting Species 161 8.4.1 Brief Description of Major Species 175 8.5 Other Relevant Products 180 8.6 Summary 183 Endnotes 183 References 184 9 Pretreatment Options 199 Bradley A. Saville 9.1 Overview of Pretreatment Technologies 199 9.1.1 History 199 9.1.2 Mechanistic Assessment of Pretreatment 200 9.1.3 Severity Factor Concept 203 9.2 Pretreatment Classification 205 9.2.1 Mechanical Pretreatment Processes 206 9.2.2 Chemical Pretreatment Processes 206 9.2.3 Thermochemical Pretreatment Processes 209 9.2.4 Impact on Moisture Content and Hydraulic Load 210 9.3 Laboratory vs. Commercial Scale Pretreatment—What Do We Really Know? 211 9.3.1 Laboratory Studies 211 9.3.2 Pilot/Demonstration Scale Studies 211 9.3.3 Limitations of Laboratory-Scale Comparisons of Pretreatment Methods 214 9.4 Process Issues and Trade-Offs 215 9.4.1 Inhibitors 215 9.4.2 Hydrolysis Efficiency and Enzyme Loadings 218 9.4.3 Solvent/Catalyst Recovery 218 9.4.4 Viscosity Reduction and Hydraulic Load 218 9.5 Economics 220 9.6 Conclusions 224 References 224 10 Enzyme Production Systems for Biomass Conversion 227 John A. Howard, Zivko Nikolov, and Elizabeth E. Hood 10.1 Introduction 227 10.2 The Challenge: Volume and Cost of Enzymes Required 227 10.3 Theoretical Ways to Address the Challenge of Quantity of Enzyme and Cost Requirements 228 10.3.1 Increase Susceptibility for Biomass Deconstruction 229 10.3.2 Decrease Exogenous Enzyme Load 231 10.3.3 Increase Accumulation of Enzymes in Production Host 236 10.4 Cost of Producing Exogenous Enzymes 240 10.4.1 Cost Analysis 242 10.5 Summary and Future Prospects 245 References 246 11 Fermentation-Based Biofuels 255 Randy Kramer and Helene Belanger 11.1 Introduction 255 11.2 First-Generation Biofuels 256 11.2.1 Starch-Based Ethanol—United States 256 11.2.2 Sugar-Based Ethanol—Brazil 257 11.2.3 Biodiesel 258 11.3 Policy and Biofuel Implementation Status 260 11.3.1 North America 260 11.3.2 South America 262 11.3.3 Europe 262 11.3.4 Asia 263 11.4 Second-Generation Biofuels 265 11.4.1 Cellulosic Ethanol 265 11.4.2 Biobutanol 268 11.5 Issues for Biofuels Commercial Success 269 11.5.1 Transport by Pipeline 269 11.5.2 Decentralized Production and Local Distribution 270 11.5.3 Optimized Engine Performance 271 11.5.4 Value of Biorefinery Co-products 272 11.6 Summary 272 References 272 12 Biobased Chemicals and Polymers 275 Randall W. Powell, Clare Elton, Ross Prestidge, and Helene Belanger 12.1 Introduction 275 12.2 Biobased Feedstock Components 276 12.3 Biomass Conversion Technologies 277 12.3.1 Technology Platforms Overview 277 12.3.2 Lignocellulose Fractionation Overview 279 12.4 Biobased Products 287 12.4.1 Oil-Based Products 287 12.4.2 Sugar/Starch-Based Products 289 12.4.3 Polymer Products 293 12.4.4 Lignin Products 299 12.5 Summary 303 References 304 13 Carbon Offset Potential of Biomass-Based Energy 311 Gauri-Shankar Guha 13.1 Emerging Public Interest in Carbon 311 13.1.1 Overview 311 13.1.2 Initiatives to Address Anthropogenic Climate Change 311 13.1.3 GHG Mitigation and Carbon Sequestration Strategies 314 13.2 Theory of Carbon Markets 314 13.2.1 Tradable Permits and the Market for Emissions 314 13.2.2 Concept of Carbon Markets 315 13.2.3 Demand and Supply of Carbon Credits 316 13.3 Creation of Carbon Markets 317 13.3.1 Carbon Credits 317 13.3.2 Global Carbon Trade 318 13.3.3 Carbon Trading in the United States 318 13.3.4 The CCX Offset Program 318 13.4 Role of Biomass-Based Energy in Carbon Markets 319 13.4.1 Economic Significance of Bioenergy 319 13.4.2 Bioenergy Policies, Practices, and Trends 321 13.4.3 Carbon Offset Opportunities for Biofuels 323 13.5 Prognosis of Carbon Markets 324 References 325 14 Biofuel Economics 329 Daniel Klein-Marcuschamer, Brad Holmes, Blake A. Simmons, and Harvey W. Blanch 14.1 Introduction 329 14.2 Production Processes 330 14.3 Biomass Transportation and Handling 331 14.4 Conversion of Biomass into Sugars 332 14.5 Conversion of Sugars into Biofuels 335 14.6 Separation and Purification 337 14.7 Co-product Handling 337 14.8 Major Cost Drivers 338 14.8.1 Biomass-Associated Costs 338 14.8.2 Capital Expenses 340 14.8.3 Operating Costs 342 14.9 Risks 343 14.10 Policy Support 345 14.11 Infrastructure and Vehicle Modifications 346 14.12 Conclusions 347 14.13 Acknowledgments 348 References 348 Index 355

About the Author :
Elizabeth Hood, Ph.D, is a Distinguished Professor of Agriculture at Arkansas State University. Peter Nelson is a principal in BioDimensions, providing services for startup companies developing green technology. Randy Powell, Ph.D, is the president of Powell Consulting, LLC, a construction consulting firm promoting biofuel and bioproducts.

Review :
"Overall it gives very good insights on biomass feedstocks for all uses of biomass as well as fermentation technologies mainly for biofuels." (Encyclopedia of Industrial Biotechnology, 30 August 2011)