Preface ........................................................ ix
1 Introduction
Tong-Qi Yuan and Run-Cang Sun
References ................................................... 5
2 Structure, infrastructure, and Chemical Composition
Feng Xu
2.1 Anatomical Structure .................................... 9
2.2 Ultrastructure ......................................... 10
2.2.1 Ultrastructure of Wood .......................... 10
2.2.2 Ultrastructure of Grass ......................... 15
2.3 Distribution of Polysaccharides and Lignin ............. 18
2.3.1 Polysaccharides Distribution .................... 18
2.3.2 Lignin Distribution ............................. 21
2.4 Chemical Composition ................................... 29
2.4.1 Cellulose ....................................... 31
2.4.2 Hemicelluloses .................................. 34
2.4.3 Lignin .......................................... 37
2.4.4 Pectic Substances ............................... 39
2.4.5 Proteins ........................................ 40
2.4.6 Cutins, Suberins, Waxes and Other Extracts ...... 40
2.4.7 Ash ............................................. 43
References .................................................. 43
3 Extractives
Pai Peng, Jing Bian and Run-Cang Sun
3.1 Isolation and Purification ............................. 50
3.1.1 Procedures for Isolation of Extractives ......... 50
3.1.2 Purification of Extractives ..................... 51
3.2 Structural Characterization ............................ 52
3.2.1 Chemical Composition of Extractives ............. 52
3.2.2 Spectroscopic and Thermal Characterization ...... 62
References .................................................. 70
4 Hemicelluloses
Jun-Li Ren and Run-Cang Sun
4.1 Introduction ........................................... 73
4.2 Occurrence, Nature, and Classification ................. 73
4.2.1 Occurrence, Nature, and Classification of
Hemicelluloses .................................. 74
4.2.2 Occurrence, Nature, and Classification of
Straw Hemicelluloses ............................ 76
4.3 Isolation, Analysis, and Structure ..................... 77
4.3.1 Isolation ....................................... 77
4.3.2 Structural Analysis of Straw Hemicelluloses ..... 85
4.3.3 Structure ....................................... 89
4.4 Physicochemical Properties ............................. 96
4.4.1 Solubility ...................................... 96
4.4.2 Mw and Mw Distribution .......................... 96
4.4.3 Rheological Behavior ............................ 97
4.4.4 Surface Tension ................................. 98
4.4.5 Thermal Behavior ................................ 99
4.4.6 Biological Activity ............................ 100
4.5 Interactions with Cellulose ........................... 100
4.5.1 Interaction of Hemicelluloses with Celluloses
in Production of Celluloses .................... 101
4.5.2 Interaction of Hemicelluloses with Celluloses
in Papermaking Process ......................... 103
4.5.3 Effect of Interaction of Hemicelluloses with
Celluloses on the Bioethanol Production ........ 104
4.5.4 The Assembly Characteristics of
Hemicelluloses on Cellulose .................... 105
4.6 Modification of Hemicelluloses and its Application .... 105
4.6.1 The Potential Modification of Hemicelluloses ... 105
4.6.2 Chemical Modification and its Application ...... 106
4.6.3 Straw Hemicelluloses and their Application ..... 117
4.7 Summary .......................................... 118
References ................................................. 119
5 Cellulose
Chuan-Fu Liu and Run-Cang Sun
5.1 Occurrence ............................................ 131
5.2 Isolation ............................................. 132
5.2.1 Delignification and Alkali Extraction .......... 132
5.2.2 Steam Explosion ................................ 134
5.2.3 Alkaline Peroxide Extraction ................... 135
5.2.4 Organic Solvent Extraction ..................... 135
5.2.5 Other Isolation Methods ........................ 136
5.3 Structure and the Crystalline Lattice of
Cellulose I ........................................... 138
5.3.1 Supermolecular Structure ....................... 138
5.3.2 Cellulose Lattice I ............................ 138
5.3.3 Conversion of Cellulose I to Cellulose II ...... 142
5.4 Physico-Chemical Properties ........................... 143
5.4.1 Structural Properties .......................... 143
5.4.2 Dissolution of Cellulose ....................... 146
5.4.3 Regeneration of Cellulose ...................... 151
5.4.4 Hydrolysis of Cellulose ........................ 153
5.5 Chemical Modification and its Utilization ............. 154
5.5.1 Acetylation .................................... 155
5.5.2 Acylation with Other Linear Anhydrides or
Chlorides ...................................... 157
5.5.3 Esterification with Cyclic Anhydrides .......... 157
5.5.4 Carboxymethylation ............................. 158
5.5.5 Other Chemical Modification .................... 161
5.6 Concluding Remarks .................................... 162
References ................................................. 162
6 Lignin
FaChuang Lu and John Ralph
6.1 Introduction .......................................... 169
6.2 Monolignols, and Lignification in Grass Cell Walls .... 170
6.2.1 Biosynthesis of Monolignols .................... 170
6.2.2 Lignin Deposition and Topochemistry ............ 171
6.2.3 Lignification - Polymerization of
Monolignols .................................... 173
6.3 Isolation and Purification of Lignins ................. 174
6.3.1 Milled Wood Lignin ............................. 175
6.3.2 Enzyme Lignin .................................. 177
6.3.3 Alkali Lignins ................................. 178
6.3.4 Organosolv Lignin .............................. 180
6.3.5 Purification of Lignins ........................ 182
6.4 Analytical Methods for Lignin Characterization ........ 183
6.4.1 Thioacidolysis ................................. 183
6.4.2 DFRC Method .................................... 184
6.4.3 Nuclear Magnetic Resonance Spectroscopy ........ 185
6.5 Structural Characteristics of Straw Lignins ........... 187
6.5.1 Ferulates in Grass Lignins ..................... 188
6.5.2 ρ-Coumarates in Grass Lignins .................. 192
6.5.3 Lignin-Carbohydrate Complexes in Grasses ....... 193
6.6 Utilization of Lignins ................................ 194
6.6.1 Wood Adhesives Made from Lignins ............... 195
6.6.2 Biochemicals/Biofuel from Lignins .............. 196
6.7 Concluding Remarks .................................... 197
References ................................................. 198
7 Chemical Modification of Straw as Novel Materials for
Industries
7.1 Chemical Modification of Cereal Straws as Natural
Sorbents in Oil Spill Cleanup ......................... 209
Diao She, Run-Cang Sun and Gwynn Lloyd Jones
7.1.1 Hazard of Oil Spill ............................ 209
7.1.2 Methods for Controlling Oil Spills ............. 209
7.1.3 Classification of Oil Sorbents ................. 209
7.1.4 Principles of Sorbency ......................... 210
7.1.5 Influence of Sorptive Capacity ................. 210
7.1.6 Chemical Modification of Cereal Straws as Oil
Sorbents ....................................... 211
7.1.7 Types of Catalysts in Chemical Modification .... 212
7.1.8 Agro-Based Sorbent Application ................. 213
References ................................................. 216
7.2 Modification of Cereal Straws as Natural Sorbents
for Removing Metal Ions from Industrial Waste Water
Feng Peng and Run-Cang Sun
7.2.1 Introduction ................................... 219
7.2.2 Mechanism of Metal Biosorption ................. 220
7.2.3 Adsorption Models .............................. 220
7.2.4 Methods of Chemical Modification ............... 221
7.2.4.1 The Methods of Direct Chemical
Modification .......................... 222
7.2.4.2 Chemical Grafting Modification ........ 223
7.2.5 Chemically Modified Straw ...................... 227
7.2.5.1 Sugarcane Bagasse ..................... 227
7.2.5.2 Rice Straw/Husks/Hulls ................ 230
7.2.5.3 Wheat Straw/Wheat Bran ................ 231
7.2.5.4 Corncobs .............................. 231
7.2.5.5 Soybean Straw/Hull .................... 232
7.2.5.6 Other Straw/Hulls ..................... 233
7.2.6 Summary ........................................ 233
References ................................................. 234
7.3 Modification of Straw for Activated Carbon
Preparation and Application for the Removal of Dyes
from Aqueous Solutions
Tong-Qi Yuan and Run-Cang Sun
7.3.1 Introduction ................................... 239
7.3.2 Technologies Available for Dye Removal ......... 239
7.3.2.1 Biological Treatments ................. 240
7.3.2.2 Chemical Methods ...................... 240
7.3.2.3 Physical Methods ...................... 240
7.3.3 Dye Removal Using Commercial Activated
Carbons ........................................ 241
7.3.4 Dye Removal Using Agricultural Wastes or
Byproducts ..................................... 242
7.3.5 Production of Acs from Agricultural
Byproducts ..................................... 244
7.3.5.1 Physical Activation ................... 245
7.3.5.2 Chemical Activation ................... 245
7.3.5.3 Dye Removal Using Acs from
Agricultural Byproducts ............... 245
7.3.6 Summary ........................................ 247
References ................................................. 248
7.4 Liquefaction and Gasification of Cereal Straws
Ming-Fei Li and Run-Cang Sun
7.4.1 Hydrothermal Liquefaction ...................... 253
7.4.2 Solvolytic Liquefaction ........................ 256
7.4.3 Thermal Gasification ........................... 259
7.4.4 Hydrothermal Gasification ...................... 261
References ................................................. 263
7.5 Biorefinery Straw for Bioethanol
Кun Wang and Run-Cang Sun
7.5.1 Introduction ................................... 267
7.5.2 Lignocellulosic Biomass Recalcitrance .......... 268
7.5.3 Biorefinery Straw for Bioethanol Production .... 270
7.5.3.1 Acid Hydrolysis ....................... 270
7.5.3.2 Enzymatic Hydrolysis .................. 272
7.5.4 Summary ........................................ 282
References ................................................. 283
Index ......................................................... 289
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