Thermochemical Processing of Biomass

Editor Robert C. Brown, Distinguished Professor of Engineering, Iowa State University, Ames, USA Series Editor Christian Stevens, Faculty of Bioscience Engineering, Ghent University, Belgium For more information on the Wiley Series in Renewable Resources, visit www.wiley.com/go/rrs

List of Contributors xv Series Preface xvii Preface xix 1 Introduction to Thermochemical Processing of Biomass into Fuels, Chemicals, and Power 1 Xiaolei Zhang and Robert C. Brown 1.1 Introduction 1 1.2 Thermochemical Conversion Technologies 5 1.2.1 Direct Combustion 5 1.2.2 Gasification 6 1.2.3 Pyrolysis 7 1.2.4 Solvent Liquefaction 8 1.3 Diversity of Products: Electric Power, Transportation Fuels, and Commodity Chemicals 8 1.3.1 Biopower 9 1.3.2 Biofuels 10 1.3.3 Bio-Based Chemicals 11 1.4 Economic Considerations 11 1.5 Environmental Considerations 12 1.6 Organization of This Book 13 References 14 2 Condensed Phase Reactions During Thermal Deconstruction 17 Jake K. Lindstrom, Alexander Shaw, Xiaolei Zhang, and Robert C. Brown 2.1 Introduction to Condensed Phase Reactions During Thermal Deconstruction of Biomass 17 2.2 Thermochemical Processes 19 2.2.1 Processes Yielding Chiefly Solids 20 2.2.2 Processes Yielding Chiefly Liquids 22 2.2.3 Processes Yielding Chiefly Gases 24 2.3 Understanding Condensed Phase Reactions 28 2.3.1 Challenges in Investigating Condensed Phase Reactions 28 2.3.2 The Role of Cell Wall Structure in Thermal Deconstruction 30 2.3.3 Use of Computational Chemistry to Understand Thermal Deconstruction 34 2.4 Conclusions 41 References 42 3 Biomass Combustion 49 Bryan M. Jenkins, Larry L. Baxter, and Jaap Koppejan 3.1 Introduction 50 3.2 Combustion Systems 51 3.2.1 Fuels 51 3.2.2 Types of Combustors 53 3.3 Fundamentals of Biomass Combustion 59 3.3.1 Combustion Properties of Biomass 59 3.3.2 Combustion Stoichiometry 65 3.3.3 Equilibrium 68 3.3.4 Rates of Reaction 68 3.4 Pollutant Emissions and Environmental Impacts 71 3.4.1 Oxides of Nitrogen and Sulfur 72 3.4.2 Products of Incomplete Combustion 74 3.4.3 Particulate Matter 74 3.4.4 Dioxin-Like Compounds 74 3.4.5 Heavy Metals 76 3.4.6 Radioactive Species 76 3.4.7 Greenhouse Gas Emissions 77 References 77 4 Gasification 85 Karl M. Broer and Chad Peterson 4.1 Introduction 85 4.1.1 History of Gasification 85 4.1.2 Gasification Terminology 87 4.2 Fundamentals of Gasification 88 4.2.1 Heating and Drying 89 4.2.2 Pyrolysis 89 4.2.3 GasSolid Reactions 90 4.2.4 Gas-Phase Reactions 91 4.3 Feed Properties 91 4.4 Classifying Gasifiers According to Method of Heating 95 4.4.1 Air-Blown Gasifiers 95 4.4.2 Oxygen/Steam-Blown Gasifiers 96 4.4.3 Indirectly Heated Gasifiers 96 4.5 Classifying Gasifiers According to Transport Processes 98 4.5.1 Fixed Bed 99 4.5.2 Bubbling Fluidized Bed (BFB) 101 4.5.3 Circulating Fluidized Bed (CFB) 103 4.5.4 Entrained Flow 104 4.6 Pressurized Gasification 106 4.7 Products of Gasification 106 4.7.1 Gaseous Products 106 4.7.2 Char and Tar 109 4.8 System Applications 110 4.8.1 Process Heat 110 4.8.2 Combined Heat and Power (CHP) 117 4.8.3 Fuel and Chemical Synthesis 117 Acknowledgement 118 References 118 5 Syngas Cleanup, Conditioning, and Utilization 125 David C. Dayton, Brian Turk, and Raghubir Gupta 5.1 Introduction 125 5.2 Syngas Cleanup and Conditioning 126 5.2.1 Particulates 128 5.2.2 Sulfur 130 5.2.3 Ammonia Decomposition and HCN Removal 132 5.2.4 Alkalis and Heavy Metals 132 5.2.5 Chlorides 133 5.2.6 Tars and Soot 134 5.3 Syngas Utilization 137 5.3.1 Syngas to Gaseous Fuels 138 5.3.2 Syngas to Liquid Fuels 145 5.4 Summary and Conclusions 159 References 164 6 Fast Pyrolysis 175 Robbie H. Venderbosch 6.1 Introduction 175 6.2 Fundamentals of Pyrolysis 175 6.2.1 Effects of the Chemical and Physical Structure of Biomass and Intermediate Products 176 6.2.2 Effects of Ash 179 6.3 Properties of Pyrolysis Liquids 184 6.4 Fast Pyrolysis Process Technologies 186 6.4.1 Ensyn (CFB) 186 6.4.2 Valmet/UPM (CFB) 188 6.4.3 BTG-BtL (Rotating-cone) 188 6.4.4 Dynamotive Technologies Corp 190 6.5 Applications of Pyrolysis Liquids 192 6.5.1 Combustion 192