List of Contributors xi
1 Introductory Remarks 1
Tilman J. Schildhauer
1.1 Why Produce Synthetic Natural Gas? 1
1.2 Overview 3
2 Coal and Biomass Gasification for SNG Production 5
Stefan Heyne, Martin Seemann, and Tilman J. Schildhauer
2.1 Introduction - Basic Requirements for Gasification in the Framework of SNG Production 5
2.2 Thermodynamics of Gasification 6
2.2.1 Gasification Reactions 7
2.2.2 Overall Gasification Process - Equilibrium Based Considerations 7
2.2.3 Gasification - A Multi?]step Process Deviating from Equilibrium 11
2.2.4 Heat Management of the Gasification Process 13
2.2.5 Implication of Thermodynamic Considerations for Technology Choice 18
2.3 Gasification Technologies 18
2.3.1 Entrained Flow 19
2.3.2 Fixed Bed 20
2.3.3 Direct Fluidized Bed 22
2.3.4 Indirect Fluidized Bed Gasification 27
2.3.5 Hydrogasification and Catalytic Gasification 34
References 37
3 Gas Cleaning 41
Urs Rhyner
3.1 Introduction 41
3.2 Impurities 42
3.2.1 Particulate Matter 42
3.2.2 Tars 43
3.2.3 Sulfur Compounds 43
3.2.4 Halide Compounds 44
3.2.5 Alkali Compounds 44
3.2.6 Nitrogen Compounds 44
3.2.7 Other Impurities 44
3.3 Cold, Warm and Hot Gas Cleaning 45
3.3.1 Example of B?]IGFC Gas Cleaning Process Chains 45
3.4 Gas Cleaning Technologies 47
3.4.1 Particulate Matter 47
3.4.2 Tars 52
3.4.3 Sulfur Compounds 57
3.4.4 Hydrodesulfurization 59
3.4.5 Chlorine (Halides) 60
3.4.6 Alkali 61
3.4.7 Nitrogen?]containing Compounds 61
3.4.8 Other Impurities 62
3.5 Reactive Hot Gas Filter 62
References 65
4 Methanation for Synthetic Natural Gas Production - Chemical Reaction Engineering Aspects 77
Tilman J. Schildhauer
4.1 Methanation - The Synthesis Step in the Production of Synthetic Natural Gas 77
4.1.1 Feed Gas Mixtures for Methanation Reactors 79
4.1.2 Thermodynamic Equilibrium 82
4.1.3 Methanation Catalysts: Kinetics and Reaction Mechanisms 88
4.1.4 Catalyst Deactivation 97
4.2 Methanation Reactor Types 107
4.2.1 Adiabatic Fixed Bed Reactors 109
4.2.2 Cooled Reactors 117
4.2.3 Comparison of Methanation Reactor Concepts 129
4.3 Modeling and Simulation of Methanation Reactors 132
4.3.1 How to Measure (Intrinsic) Kinetics? 133
4.3.2 Modeling of Fixed Bed Reactors 136
4.3.3 Modeling of Isothermal Fluidized Bed Reactors 139
4.4 Conclusions and Open Research Questions 146
4.5 Symbol List 148
References 149
5 SNG Upgrading 161
Renato Baciocchi, Giulia Costa, and Lidia Lombardi
5.1 Introduction 161
5.2 Separation Processes for SNG Upgrading 163
5.2.1 Bulk CO2/CH4 Separation 163
5.2.2 Removal of other Compounds and Impurities 169
5.3 Techno?]Economical Comparison of Selected Separation Options 174
References 176
6 SNG from Wood - The GoBiGas Project 181
Jörgen Held
6.1 Biomethane in Sweden 181
6.2 Conditions and Background for the GoBiGas Project in Gothenburg 184
6.3 Technical Description 185
6.4 Technical Issues and Lessons Learned 188
6.5 Status 188
6.6 Efficiency 188
6.7 Economics 188
6.8 Outlook 189
Acknowledgements 189
References 189
7 The Power to Gas Process: Storage of Renewable Energy in the Natural Gas Grid via Fixed Bed Methanation of CO2/H2 191
Michael Specht, Jochen Brellochs, Volkmar Frick, Bernd Stürmer, and Ulrich Zuberbühler
7.1 Motivation 191
7.1.1 History "Renewable Fuel Paths at ZSW" 191
7.1.2 Goal "Energiewende" 192
7.1.3 Goal "Power Based, Carbon Based Fuels" 192
7.1.4 Goal "P2G(r)" 192
7.1.5 Goal "Methanation" 193
7.2 The Power to Fuel Concept: Co?]utilization of (Biogenic) Carbon and Hydrogen 193
7.3 P2G(r) Technology 196
7.3.1 Methanation Characteristics for CO2 Based Syngas 197
7.3.2 P2G(r) Plant Layout of 25 kWel, 250 kWel, and 6000 kWel Plants 202
7.4 Experimental Results 206
7.4.1 Methanation Catalysts: Screening, Cycle Resistance, Contamination by Sulfur Components 206
7.4.2 Results with the 25 kWel P2G(r) Plant 209
7.4.3 Results with the 250 kWel P2G(r) Plant 210
7.4.4 Results with the 250 kWel P2G(r) Plant in Combination with Membrane Gas Upgrade 213
7.5 P2G(r) Process Efficiency 214
7.6 Conclusion and Outlook 217
Acknowledgements 219
References 219
8 Fluidized Bed Methanation for SNG Production - Process Development at the Paul?]Scherrer Institut 221
Tilman J. Schildhauer and Serge M.A. Biollaz
8.1 Introduction to Process Development 221
8.2 Methane from Wood - Process Development at PSI 223
References 229
9 MILENA Indirect Gasification, OLGA Tar Removal, and ECN Process for Methanation 231
Luc P.L.M. Rabou, Bram Van der Drift, Eric H.A.J. Van Dijk, Christiaan M. Van der Meijden, and Berend J. Vreugdenhil
9.1 Introduction 231
9.2 Main Process Steps 233
9.2.1 MILENA Indirect Gasification 233
9.2.2 OLGA Tar Removal 236
9.2.3 HDS and Deep S Removal 237
9.2.4 Reformer 238
9.2.5 CO2 Removal 239
9.2.6 Methanation and Upgrading 239
9.3 Process Efficiency and Economy 240
9.4 Results and Status 241
9.4.1 MILENA 241
9.4.2 OLGA 242
9.4.3 HDS, Reformer, and Methanation 243
9.5 Outlook 245
9.5.1 Pressure 245
9.5.2 Co?]production 245
9.5.3 Bio Carbon Capture and Storage 246
9.5.4 Power to Gas 246
Acknowledgements 246
References 247
10 Hydrothermal Production of SNG from Wet Biomass 249
Frédéric Vogel
10.1 Introduction 249
10.2 Historical Development 252
10.3 Physical and Chemical Bases 253
10.3.1 Catalysis 254
10.3.2 Phase Behavior and Salt Separation 259
10.3.3 Liquefaction of the Solid Biomass, Tar, and Coke Formation 263
10.4 PSI's Catalytic SNG Process 266
10.4.1 Process Description and Layout 266
10.4.2 Mass Balance 268
10.4.3 Energy Balance 269
10.4.4 Status of Process Development at PSI 269
10.4.5 Comparison to other SNG Processes 271
10.5 Open Questions and Outlook 273
References 274
11 Agnion's Small Scale SNG Concept 279
Thomas Kienberger and Christian Zuber
References 291
12 Integrated Desulfurization and Methanation Concepts for SNG Production 293
Christian F.J. König, Maarten Nachtegaal, and Tilman J. Schildhauer
12.1 Introduction 293
12.2 Concepts for Integrated Desulfurization and Methanation 295
12.2.1 Sulfur?]Resistant Methanation 295
12.2.2 Regeneration of Methanation Catalysts 297
12.2.3 Discussion of the Concepts 300
12.3 Required Future Research 301
12.3.1 Sulfur Resistant Methanation 301
12.3.2 Periodic Regeneration 302
References 303
Index 307
