First Foreword................................................... 5
Second Foreword ................................................. 7
Preface ........................................................ 19
Chapter 1
Introduction ................................................... 21
1.1 The cellulose molecule ..................................... 21
1.1.1 Molecular structure .................................. 21
1.1.2 Glucose chemistry .................................... 23
1.1.3 Related di- and polysaccharides ...................... 25
Disaccharides ........................................ 25
Polysaccharides ...................................... 26
1.2 Structure of the book ...................................... 30
1.3 References ................................................. 31
Chapter 2
Biosynthesis of Cellulose ...................................... 33
2.1 Introduction ............................................... 33
2.2 Selective principles of botany ............................. 34
2.2.1 Classification of green plants ....................... 34
2.2.2 Plant cells .......................................... 36
2.3 Cellulose-related biology .................................. 38
2.3.1 From genes to proteins ............................... 38
2.3.2 DNA cloning and PCR .................................. 41
2.4 Terminal complexes ......................................... 41
2.5 Glucose polymerization by cellulose synthases .............. 46
2.5.1 Cellulose synthase substrate ......................... 46
2.5.2 Cellulose synthases .................................. 47
Processive β-glycosyltransferases .................... 47
Conserved motifs ..................................... 48
Cellulose synthase family ............................ 49
2.5.3 Polymerization models ................................ 51
2.5.4 Polymerization of cellulose
in Acetobacter xylinum ............................... 54
Biosynthetic pathway of cellulose .................... 54
UniProt description .................................. 57
Other bacteria ....................................... 57
2.5.5 Polymerization of cellulose in plants ................ 58
Genes encoding cellulose synthases ................... 58
Korrigan ............................................. 64
Sitosterol-β-glucoside primer ........................ 66
Other non-catalytic molecules ........................ 67
2.6 Chain assembly into microfibrils ........................... 68
2.6.1 Chain assembly in Acetobacter xylinum ................ 69
2.6.2 Chain assembly in plants ............................. 70
2.7 Status of non-in-vivo cellulose synthesis .................. 75
2.7.1 In vitro synthesis ................................... 75
Synthesis by bacterial synthases ..................... 75
Synthesis by plant synthases ......................... 75
Enzymatic polymerization ............................. 76
2.7.2 Chemical synthesis ................................... 79
2.8 References ................................................. 80
Chapter 3
Structure and Properties of Cellulose .......................... 87
3.1 Introduction ............................................... 87
3.2 Supramolecular structure ................................... 88
3.2.1 Crystallinity of cellulose materials ................. 88
3.2.2 Crystal polymorphs ................................... 89
3.2.3 Coordinate system .................................... 90
3.2.4 Cellulose 1 .......................................... 90
3.2.5 Cellulose II ........................................ 101
3.2.6 Cellulose III and IV ................................ 105
3.2.7 Soda celluloses ..................................... 107
3.2.8 Summary of crystal structures ....................... 108
3.3 Morphological structure ................................... 109
3.3.1 Introduction ........................................ 109
3.3.2 Microfibrils ........................................ 110
Types of microfibrils ............................... 110
Crystalline features ................................ 111
Chain polarity and biosynthesis ..................... 117
Amorphous domains ................................... 117
3.3.3 Plant cell walls .................................... 118
Extracellular matrix ................................ 118
Primary cell wall ................................... 119
Microtubules ........................................ 121
Wall proteins ....................................... 122
Pores ............................................... 123
Biosynthesis ........................................ 123
Representative examples ............................. 124
3.3.4 Bacterial cellulose ................................. 127
3.4 Properties ................................................ 130
3.4.1 Mechanical properties ............................... 130
Theoretical values .................................. 130
Experimental values ................................. 130
3.4.2 Physical properties and liquid crystals ............. 132
Thermal, electrical and optical properties .......... 132
Liquid crystals ..................................... 134
3.4.3 Environmental properties ............................ 137
3.4.4 Nanocomposites ...................................... 138
3.5 References ................................................ 140
Chapter 4
Swelling and Dissolution of Cellulose ......................... 147
4.1 Introduction .............................................. 147
4.2 Intercrystalline swelling ................................. 148
4.2.1 Water ............................................... 148
Water sorption isotherms ............................ 149
Bound water ......................................... 151
Water retention value, fiber saturation point
and solute exclusion ................................ 153
Cellulose plasticization with water ................. 155
4.2.2 Organic liquids ..................................... 156
Interaction of cellulose with organic liquids ....... 156
Inclusion compounds ................................. 158
4.3 Intracrystalline swelling ................................. 158
4.3.1 Alkali metal hydroxides ............................. 159
Mercerization ....................................... 159
Alkali celluloses ................................... 159
Changes in fiber dimensions on swelling ............. 161
Supramolecular and morphological structure .......... 162
Mechanism of swelling by alkalis .................... 164
4.3.2 Inorganic acids and salts ........................... 167
4.3.3 Amines .............................................. 170
Swelling of cellulose by amines ..................... 170
Effect of amines on cellulose properties ............ 172
4.3.4 Ammonia ............................................. 173
Swelling of cellulose by liquid ammonia ............. 173
Effect of liquid ammonia on cellulose properties .... 174
4.3.5 Hydrazine ........................................... 175
4.4 Dissolution ............................................... 175
4.4.1 Non-derivatizing solvents ........................... 176
Aqueous solutions of transition metal complexes ..... 176
Non-aqueous LiCI/DMA system ......................... 177
Organic amine oxides ................................ 178
Aqueous sodium hydroxide ............................ 188
Ionic liquids ....................................... 192
4.4.2 Derivatizing solvents ............................... 194
Viscose process ..................................... 196
N204/DMF system ..................................... 200
DMSO/paraformaldehyde system ........................ 201
4.5 References ................................................ 201
Chapter 5
Enzymatic Hydrolysis of Cellulose ............................. 209
5.1 Introduction .............................................. 209
5.2 Cellulases ................................................ 210
5.2.1 Organism source ..................................... 210
5.2.2 Endo- and exo-action ................................ 210
5.2.3 Modular structure ................................... 211
Catalytic module .................................... 211
Carbohydrate-binding module ......................... 213
5.2.4 Mechanism ........................................... 217
5.2.5 Nomenclature ........................................ 218
5.3 Noncomplexed cellulase systems ............................ 219
5.3.1 Solubilization of native cellulose .................. 219
5.3.2 Trichoderma reesei (Hypocrea jecorina) .............. 220
Cel7A ............................................... 221
Cel6A ............................................... 222
Endoglucanases ...................................... 226
CBMs ................................................ 226
5.3.3 Humicola insolens ................................... 228
Cel7A ............................................... 228
Cel6A ............................................... 229
Endoglucanases ...................................... 229
Cellulose digestion ................................. 231
5.3.4 Kinetics and activity ............................... 232
5.3.5 Synergism ........................................... 233
5.4 Multienzyme complexes ..................................... 234
5.4.1 The cellulosome concept ............................. 234
5.4.2 Types of cellulosome ................................ 234
5.4.3 Scaffoldin carbohydrate-binding modules ............. 235
5.4.4 Cohesin-dockerin interaction ........................ 236
5.4.5 Representative examples of cellulosome .............. 240
Clostridium cellulolyticum .......................... 240
Clostridium thermocellum ............................ 241
Acetivibrio cellulolyticus .......................... 245
Ruminococcus flavefaciens ........................... 246
Bacteroides cellulosolvens .......................... 247
5.4.6 Designer cellulosomes ............................... 247
5.5 References ................................................ 248
Chapter 6
Non-Biological Degradation of Cellulose ....................... 257
6.1 Introduction .............................................. 257
6.2 Acid hydrolysis ........................................... 258
6.2.1 Mechanism and kinetics .............................. 258
6.3 Alkaline degradation ...................................... 260
6.3.1 Action of alkalis on monosaccharides ................ 260
6.3.2 Action of alkalis on cellulose ...................... 261
Endwise degradation (peeling) ....................... 261
Alkaline hydrolysis ................................. 262
6.4 Oxidative degradation ..................................... 263
6.4.1 Oxidation by sodium hypochlorite .................... 264
6.4.2 Oxidation by atmospheric oxygen and by hydrogen
peroxide ............................................ 265
6.5 Thermal degradation ....................................... 266
6.6 Mechanical and radiation degradation ...................... 268
6.6.1 Mechanical degradation .............................. 268
6.6.2 Radiation degradation ............................... 270
IR, visible and UV radiation ........................ 270
High-energy radiation ............................... 271
6.7 References ................................................ 272
Chapter 7
Cellulose Derivatives ......................................... 275
7.1 Introduction .............................................. 275
7.2 Esterification ............................................ 277
7.2.1 Inorganic cellulose esters .......................... 277
Cellulose nitrate ................................... 277
Cellulose nitrite ................................... 278
Cellulose sulfate ................................... 279
Phosphorus-containing cellulose derivatives ......... 279
Cellulose borates ................................... 280
Deoxycelluloses ..................................... 280
Esters of carbonic acid derivatives ................. 281
7.2.2 Organic cellulose esters ............................ 282
Cellulose formate ................................... 282
Cellulose acetate ................................... 282
Esters of higher aliphatic acids .................... 284
Cellulose carbamates ................................ 286
Cellulose sulfonates ................................ 286
7.2.3 Summary ............................................. 287
7.3 Etherification ............................................ 287
7.3.1 Alkyl ethers of cellulose ........................... 288
7.3.2 Carboxymethylcellulose .............................. 289
7.3.3 Hydroxyalkyl ethers of cellulose .................... 290
7.3.4 Cyanoethylcellulose ................................. 293
7.3.5 Other ethers of cellulose ........................... 293
7.3.6 Summary ............................................. 294
7.4 Crosslinking of cellulose ................................. 295
7.4.1 Chemical finishing of textiles and paper ............ 295
7.4.2 Crosslinking agents ................................. 296
7.5 Grafting of cellulose ..................................... 298
7.6 References ................................................ 299
Chapter 8
Fuels and Chemicals from Biomass .............................. 303
8.1 Cellulosic biomass for renewable energy and products ...... 303
8.1.1 Biomass ............................................. 303
8.1.2 Biorefinery and global warming ...................... 304
8.1.3 Bioethanol and biodiesel ............................ 305
8.1.4 Conversion pathways ................................. 306
8.2 Biochemical conversion of cellulosic biomass .............. 307
8.2.1 Enzymatic hydrolysis ................................ 308
8.2.2 Acid hydrolysis ..................................... 312
Dilute acid hydrolysis .............................. 312
Concentrated acid hydrolysis ........................ 313
8.3 Thermochemical conversion of cellulosic biomass ........... 315
8.3.1 Primary routes for thermochemical conversion ........ 315
8.3.2 Gasification ........................................ 316
Gasification followed by Fischer-Tropsch
synthesis ........................................... 316
Gasification followed by fermentation ............... 319
8.3.3 Fast pyrolysis ...................................... 321
8.3.4 Hydrothermal upgrading .............................. 322
8.4 Integrated biorefineries .................................. 323
8.5 References ................................................ 324
Chapter 9
Perspectives .................................................. 327
9.1 Cellulosic Biomass: the petroleum of the future? .......... 327
9.1.1 Planned reductions in greenhouse gas (GHG)
emissions ........................................... 327
European Union ...................................... 328
United States of America ............................ 328
9.1.2 Global biofuel production ........................... 329
9.1.3 Bioethanol costs and yields ......................... 330
9.1.4 Cellulosic biomass conversion technologies .......... 331
9.2 Biosynthesis of cellulose ................................. 333
9.3 Cellulose nanofibers ...................................... 334
9.4 Ionic liquids as new cellulose solvents ................... 335
9.5 Worldwide R&D projects .................................... 336
9.6 References ................................................ 337
Glossary ...................................................... 339
Keyword Index ................................................. 359
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