Coal Gasification: Direct Applications and Syntheses of Chemicals and Fuels

Coal Gasification: Direct Applications and Syntheses of Chemicals and Fuels - 1987

Abstract				xiii
Acknowledgements				xiii
1	SUMMARY OF RESEARCH RECOMMENDATIONS			1

2	OVERVIEW OF COAL-GASIFICATION R&D NEEDS			5
	2.1	Introduction		5
	2.2	Process Synthesis		6
	2.3	Gasifiers for Electricity Generation		8
	2.4	Gasification for Syngas Production		9
	2.5	Gasification for Syntheses of Fuels and Chemicals		10
	2.6	Gasifiers for Fuel Cells (FCs)		15
	2.7	Gasification Catalysts		15
	2.8	Gas Cleanup		16
	2.9	Summary of Research Recommendations on Environmental Issues		21
	2.10	Coal Beneficiation and Feed Preparation: Solids Processing		25
	2.11	Applications of Advanced Diagnostics to Coal Gasification Systems		29
	2.12	Fundamentals of Coal Conversion and Relation to Coal Properties		31

3	Gasification for Electricity Generation			37
	Sections 3.1 and 3.2 were written by S. B. Alpert, S. S. Penner and D. F. Wiesenhahn, Sec 3.3-3 by P.B. Tarman, and the remaining subsections of Sec 3.3, as well as Sec 3.4, by S. S. Penner and D. F. Wiesenhahn with advice in puts from correspondents identified in the subsections.
	3.1	Integrated Coal-Gasification Combined Cycles (IGCC)		37
		3.1-1	Introduction	37
		3.1-2	IGCC System Status	38
		3.1-3	Advantages IGCCs	42
		3.1-4	Future Utilization of IGCCs	44
		References for Section 3.1		44

	3.2	The Cool Water IGCC		44
		3.2-1	General Features	44
		3.2-2	Process Description	45
		3.2-3	Performance Results	47
		References for Section 3.2		49

	3.3	Selected Gasifiers for IGCC Plants		49
		3.3-1	The Texaco Coal-Gasification Process (TCGP)	49
		3.3-2	The Shell Coal-Gasification Process (SCGP)	53
		3.3-3	The U-GAS Process	58
		3.3-4	Other Gasifiers	73
		References for Section 3.3		74

	3.4	Research Recommendations for Improving Gasifiers		74
		3.4-1	Fouling and Slagging	74
		3.4-2	Corrosion and Fatigue	75
		3.4-3	High-Temperature Sulfur Removal	76
		3.4-4	Gasifiers for Low-Rank Coals	76
		3.4-5	Low-Cost Gas Separation and Air Enrichment	76
		References for Section 3.4		76

4	COAL GASIFICATION FOR SNG PRODUCTION			77
	This chapter has been written by Kermit E. Woodcock and Vernon L. Hill
	4.1	Introduction		77
		4.1-1	The Great Plains Coal Gasification Plant (GPCGP)	77
		4.1-2	General Thermodynamic Considerations	78
		4.1-3	General Flow Sheets	81

	4.2	Advanced Gasification Technology for SNG		83
		4.2-1	BGC/Lurgi Slagging Gasifier	84
		4.2-2	KRW (Kellogg-Rust-Westinghouse) Ash-Agglomerating, Fluidized-Bed Gasifier	85
		4.2-3	Rheinbraun AG, Hydrogasification	87
		4.2-4	Catalytic Coal Gasification	90

	4.3	Catalytic Methanation		90
		4.3-1	Chemistry and Thermodynamics	90
		4.3-2	Catalysis	92
		4.3-3	Commercial Processes	94
		4.3-4	Direct Methanation	94
		4.3-5	Comflux Process (Fluid-Bed Methanation)	98
		4.3-6	HICOM	99
		4.3-7	Liquid-Phase Methanation	104

	4.4	Acid-Gas Removal		105
		4.4-1	Commercial Processes	105
		4.4-2	Advanced Technologies	106

	4.5	SNG Economics		110
	4.6	Research and Development Needs		112
		4.6-1	Engineering Development and Testing	112
		4.6-2	Technology Base Data for Design	113
		4.6-3	Basic Research Needs for Advanced Systems	114
	References			114

5	GASIFICATION FOR THE SYNTHESES OF FUELS AND CHEMICALS			117
	This chapter has been written by W. O. Haag, J. C. Kuo and I. Wender
	5.1	Catalytic Conversion of Synthesis Gas to Fuels and Chemicals		117
		5.1-1	Introduction	117
		5.1-2	Synthesis of Methanol and Higher Oxygenated Compounds	120
		5.1-3	SG as a Source of Chemicals	139
		5.1-4	Fischer-Tropsch Synthesis	144
		5.1-5	Syntheses of Chemicals Using SG, CO or Methanol Plus Other Chemicals	160
		5.1-6	Other Chemicals from SG, Methanol and CO; Emerging Process	164

	5.2	Catalytic Processing of Synthesis-Gas-Derived Products		168
		5.2-1	Introduction	168
		5.2-2	Methanol-to-Gsaoline (MTG)	169
		5.2-3	Methanol Conversion to Olefins and Diesel	173
		5.2-4	Processing of Fischer-Tropsch Products	175

	5.3	Interaction of Coal Gasifiers with Synthesis Gas Conversion Processes		179
		5.3-1	Introduction	179
		5.3-2	H₂ + CO Partial Pressure Requirements	180
		5.3-3	H₂/CO Ratio Requirement	184
		5.3-4	Purity Requirements for Synthesis Gas	187

	5.4	Zeolites as Shape-Selective Catalysts		188
		5.4-1	Introduction	188
		5.4-2	Classification fo Zeolites	189
		5.4-3	Intrinsic Catalytic Properties of Zeolites	194
		5.4-4	Shape Selectivity	194
	References			197

6	COAL GASIFICATION IN FUEL-CELL APPLICATION			207
	6.1	Overview of FCs		207
		This section has been written by A. J. Appleby
		6.1-1	Introduction	207
		6.1-2	The FC as a Direct Energy-Conversion Device	209
		6.1-3	Alkaline Fuel Cells (AFCs)	213
		6.1-4	Acid Fuel Cells	217
		6.1-5	Molten Carbonate Fuel Cells (MCFCs)	221
		6.1-6	Solid Oxide Fuel Cells (SOFCs)	226
		6.1-7	Conclusions	229

	6.2	Coal Gasifiers for FCs		230
		This section has been abstracted by S. S. Penner and D. F. Wisenhahn from viewgraphs presented by D. Rastler at the Second Technical Meeting of COGARN
		6.2-1	The Site-Specific UPA Design	230
		6.2-2	The Site-Specific SCE Design	234
		6.2-3	Conclusions	236
		6.2-4	Research Needs on Gasifier-PAFC Systems	239
		6.2-5	Other Gasifier-FC Systems	239
	References			239

7	USE OF CATALYSTS DURING GASIFICATION			243
	This chapter has been prepared by S. S. Penner and D. F. Wiesenhahn
	7.1	Selected Examples of Current Research		243
		7.1-1	Introduction	243
		7.1-2	Results from the 1985 International Coal Science Conference	244
		7.1-3	Catalytic Conversions at Reduced Temperatures	249
		References for Section 7.1		257

	7.2	The Exxon Process for Catalytic Coal Gasification		258
		7.2-1	Process Features	258
		7.2-2	Development Work	261
		7.2-3	Fluid-Bed Slurry Dryer (FBSD)	266
		7.2-4	Mechanisms of Catalysis and Selection of Alternative Catalysts	266
		7.2-5	Environmental Aspects of CCG	270
		7.2-6	Large Pilot Plant	271
		References for Section 7.2		271

	7.3	Recommended Research for Syngas Production from Coal		271

8	GAS-CLEANING PROCESSES FOR COAL GASIFICATION			273
	This chapter has been written by Robert A. Magee. The Appendix to this chapter has been written by J. F. Elliot.
	8.1	Introduction		273
	8.2	Gas Cleanup Systems		274
	8.3	Quenching, Cooling and Heat Recovery		276
	8.4	Removal of Particles, Aerosols and Inorganic Compounds		277
	8.5	Acid-Gas Removal and Sulfur Recovery		278
		8.5-1	Solid Sorbents and In-Bed Desulfurization	279
		8.5-2	Sulfur-Redox Processes	282

	References			283

	Appendix: Slag for In-Bed Sulfur Removal			285

9	ENVIRONMENTAL ISSUES			291
	This chapter has been written by Edward S. Rubin.
	9.1	Introduction		291
	9.2	Overview of US Regulatory Policy		291
		9.2-1	Trends in Environmental Regulation	291
		9.2-2	Elements of Current Policy	292
		9.2-3	Future Regulatory Directions	293

	9.3	Environmental Emissions from Coal Gasification		299
		9.3-1	Process Overview	300
		9.3-2	Recent Characterization	302
		9.3-3	Methods of Environmental Control	319

	9.4	Experience at Commercial Facilities		324
		9.4-1	The Great Plains Gasification Plant	324
		9.4-2	The Cool Water Gasification Facility	325

	9.5	Research Needs and Priorities		327
		9.5-1	Current Control Technology	328
		9.5-2	Future Environmental Requirements	329
		9.5-3	Advances Control Technology	332

	References			333

10	COAL BENEFICIATION			335
	This chapter has been written by Suman P. N. Singh
	10.1	Background		335
	10.2	Current Commercial Practice		338
	10.3	Recent Advances in Coal Cleaning		343
	10.4	Conclusions		344

	References			346

11	OPTICAL DIAGNOSTICS FOR IN SITU MEASUREMENTS IN COMBUSTION ENVIRONMENTS CONTAINING COAL PARTICLES			349
	This chapter has been written by D. R. Hardesty and D. K. Ottesen

	Abstract			349

	11.1	Introduction		350
	11.2	Diagnostics Requirements		350
		11.2-1	Characteristics of Class I Flows	351
		11.2-2	Diagnostics Considerations for Class I Flows	353
		11.2-3	Characteristics of Class II Flows	355
		11.2-4	Diagnostics Considerations for Class II Flows	355

	11.3	Gas-Phase Temperature Measurement		356
		11.3-1	Raman Scattering Techniques	356
		11.3-2	Fluorescence and Absorption Techniques	363

	11.4	Gas-Phase Species Concentration Measurement		366
		11.4-1	Raman Scattering Techniques	366
		11.4-2	Fluorescence and Absorption Techniques	367

	11.5	Particle Size, Number Density and Temperature Measurements		370
		11.5-1	Single Particle Counter, SPC (Scattering) Instruments	371
		11.5-2	Imaging Methods for Analysis of Particulates	381
		11.5-3	Ensemble Methods for Analysis of Particulates	382

	11.6	Velocity Measurements in Particle-Laden Flows		383
		11.6-1	Application of Laser-Doppler Velocimetry to Coal-Derived Flow	384

	11.7	Particulate Composition Measurement by Laser-Spark Spectroscopy (LASS)		385

	References			394

12	FUNDAMENTALS OF COAL CONVERSION AND RELATION TO COAL PROPERTIES			397
	This chapter has been written by P. R. Solomon and J. M. Beer. The Appendix is by J.P. Longwell.
	12.1	Introduction		397
	12.2	Coal Characterization		399
		12.2-1	Organic Structure (Functional Groups)	399
		12.2-2	Viscosity	400
		12.2-3	Pyrolysis	400
		12.2-4	Reactivity	400
		12.2-5	Mineral Matter	401

	12.3	Fundamental Processes in Gasification and Partial Gasification		402
		12.3-1	Heat Transfer	402
		12.3-2	Pyrolysis Rates	406
		12.3-3	Devolatilization: Formation of Gases, Condensables and Char	408

	12.4	The Behavior of Coal Mineral in Gasification		423
		12.4-1	The Nature of Mineral Matter in Coal and Its Characteristics	423
		12.4-2	Behavior During Heating	424
		12.4-3	Mineralogical Transformations at High Temperatures	425
		12.4-4	Ash Agglomeration	425

	12.5	Mathematical Modeling		426
		12.5-1	Status of Model Development	426

	12.6	Research Recommendations		429
		12.6-1	Coal Characterization	429
		12.6-2	Fundamental Processes in Gasification and Partial Gasification	430
		12.6-3	Mathematical Modeling of Gasification Processes	432

		References		433

		Appendix: Effect of CaO on Combined Fluidized-Bed Gasification and Pyrolysis		440

13	GAS SUPPLIES AND SEPARATION ASH DISPOSAL, MATERIALS FOR GASIFIERS			443
	13.1	Gas Supplies and Separation		443
		This section has been abstracted by S. S. Penner and D. F. Wiesenhahn from viewgraphs and references supplies by A. Smith.

		13.1-1	Introduction	443
		13.1-2	Cryogenic Air Separation	444
		13.1-3	The MOLTOX System	446
		13.1-4	Other Air-Separation Systems	450
		13.1-5	Research Needs	450

		References for Section 13.1		451

	13.2	Utilization and Disposal of Ash from Gasifiers		452
		This section has been written by S. B. Alpert.

		13.2-1	Environmental-Impact Studies	454

	13.3	Construction Materials for Coal Gasification		455
		This section has been written by M. T. Simmad

		13.3-1	Introduction	455
		13.3-2	High-Temperature Corrosion	455
		13.3-3	Low-Temperature Corrosion	463
		13.3-4	Erosive Wear	464
		13.3-5	Mechanical Properties	465
		13.3-6	Materials for Syngas Coolers of Slagging Gasifiers	468
		13.3-7	Nuclear Heat Steam-Gasification of Coal	470

		References for Section 13.3		475

14	INTRODUCTION TO COSTING			477

	This chapter has been written by D. Pescarolo

APPENDIX
	GENERAL REMARKS ON COAL-GASIFICATION SYSTEMS			483

	This appendix has been prepared by S. S> Penner and D. F. Weisenhahn and is based on a presentation by R. Shinnar

	A-1	Stoichiometry of Coal Conversion		483
	A-2	Gasifier Efficiency		486
	A-3	Fluidized-Bed Gasifiers		490

	References			492

GLOSSARY OF SYMBOLS AND ABBREVIATIONS				493

FORMAL REVIEWS OF THE COGARN REPORT				499