Combustion Engineering Issues for Solid Fuel Systems

cover.jpg......Page 1
Dedication......Page 2
Preface......Page 3
List of Authors......Page 7
Overview......Page 9
A Perspective on Solid Fuel Utilization......Page 10
Fuels and Combustion Technology Development......Page 12
Characteristics of Solid Fuels......Page 13
Some Economic Considerations of Solid Fuels......Page 16
The Combustion Process for Solid Fuels......Page 19
Heating and Drying......Page 20
Pyrolysis or Devolatilization......Page 23
Volatile Oxidation Reactions......Page 26
Char Oxidation Reactions......Page 27
Formation of Airborne Emissions......Page 29
Reactions of Inorganic Matter......Page 30
Combustion and Heat Release......Page 32
Fuel Quality and Fuel Management......Page 34
Fuel Preparation......Page 35
Burners and the Combustion Systems......Page 36
Post-Combustion Controls......Page 37
References......Page 38
Introduction to Coal......Page 41
Coal Formation and Coalification......Page 42
Coal Rank......Page 45
Coal Type......Page 46
International Classification System......Page 49
World Coal Reserves......Page 52
United States Coal Resources and Reserves......Page 55
Coal Production......Page 56
World Coal Production......Page 59
United States Coal Production......Page 60
Traditional Coal Characterization Methods and Their Industrial Application......Page 69
Proximate Analysis......Page 77
Heating Value......Page 78
Ash Composition......Page 79
Free-Swelling Index (FSI)......Page 80
Nontraditional Characterization Methods and Their Industrial Application......Page 81
Coal Reactivity......Page 82
Volatile Matter Evolution Patterns......Page 85
References......Page 88
Introduction......Page 90
The Use of Alternative Fuels in Electric Utility Boilers......Page 91
Cofiring Alternative Fuels in Process Industries and Independent Power Producers......Page 93
Petroleum Coke......Page 94
Fuel Characteristics of Petroleum Coke......Page 95
Proximate and Ultimate Analysis of Petroleum Coke......Page 96
Ash Characteristics of Petroleum Coke......Page 97
Petroleum Coke Utilization in Cyclone Boilers......Page 99
Cofiring Petroleum Coke in Pulverized Coal Boilers......Page 100
Petroleum Coke Utilization in Fluidized-Bed Boilers......Page 101
Woody Biomass......Page 103
Types of Woody Biomass Fuels......Page 105
Physical and Chemical Characteristics of Woody Biomass Fuels......Page 106
Inorganic Matter in Woody Biomass......Page 107
Trace Metal Concentrations......Page 108
Using Woody Biomass in Dedicated Boilers......Page 109
Woody Biomass in Pulverized Coal Firing Applications......Page 113
Cofiring Woody Biomass in Cyclone Boilers......Page 114
Conclusions Regarding Using Woody Biomass as an Alternative Fuel......Page 115
Tire-Derived Fuel (TDF)......Page 117
General Description of Tire-Derived Fuel......Page 118
Proximate and Ultimate Analysis of Tire-Derived Fuel......Page 119
Ash Constituents of TDF......Page 120
Cofiring Applications with Tire-Derived Fuel......Page 121
Summary Regarding TDF as an Alternative Fuel......Page 122
Types of Herbaceous Biomass Fuels......Page 123
Sources and Uses of Herbaceous Materials......Page 124
Density of Switchgrass and Related Materials......Page 125
Proximate and Ultimate Analysis of Switchgrass and Related Agricultural Materials......Page 126
Ash Chemistry for Herbaceous Biomass Fuels......Page 128
Herbaceous Crop Summary......Page 130
References......Page 131
Introduction......Page 139
Distribution of Inorganic Constituents in Coal......Page 142
Methods of Determining Inorganic Composition......Page 143
Subbituminous Coals......Page 154
Bituminous Coals......Page 155
World-Traded Coals......Page 156
Ash Formation: Transformation of Coal Inorganic Constituents......Page 157
Deposition Phenomena in Utility Boilers......Page 159
Slagging Deposits......Page 161
Fouling Deposits......Page 162
High-emperature Fouling......Page 163
Low-Temperature Fouling......Page 164
Ash Impacts on SCR Catalyst......Page 165
Deposit Thermal Properties......Page 166
Deposit Strength Development......Page 167
Deposit Characterization......Page 168
References......Page 173
Introduction......Page 177
Types of Fuel Blending......Page 178
The Reasons for Fuel Blending......Page 179
Issues for Fuel Blending......Page 180
Equipment and Controls Issues Associated with Fuel Blending......Page 181
The Blending System at Monroe Power Plant......Page 182
Alternative Blending Systems......Page 183
Fuel and Combustion Effects of Blending......Page 187
Development of Combustion Models as an Analytical Tool......Page 188
Volatility and Volatile Release Patterns......Page 191
Ash Chemistry......Page 193
Operational Issues with Fuel Blending......Page 199
Managing Blend Changes......Page 200
References......Page 202
Fuel Preparation......Page 204
Fuel Types......Page 205
Fuel Issues......Page 206
Coal......Page 207
Petroleum-Based Products......Page 209
Biomass......Page 210
Storage Capacity......Page 211
Silo/Bunker Design Considerations......Page 213
Solid Fuel Flow Control......Page 216
Fuel Sizing Equipment......Page 219
Pulverized Coal System Analysis Guidelines......Page 230
Mill Sizing and Standard Ratings......Page 231
Coal Mill Capacity and Capability Analysis......Page 234
Coal Throughput Capability......Page 235
Air Heater Leakage......Page 237
Thermal Requirements......Page 239
Coal Mill Capability Test Plan......Page 242
References......Page 244
Overview......Page 246
Pulverized Firing Systems......Page 247
Electricity Generation......Page 248
Industrial Boilers, Kilns, and Process Heaters......Page 251
Fuel Selection......Page 252
Operational Considerations......Page 254
NOx......Page 255
Other Emissions (Hazardous Air Pollutants)......Page 256
Basic Description and Identification of Types......Page 257
Fuel Selection for Stokers......Page 258
Design Parameters......Page 259
Functioning of Grates......Page 260
Applications......Page 261
Wall-Fired Pulverized Coal Boilers and Firing Systems......Page 262
Tangentially Fired Pulverized Coal Boilers......Page 267
Pulverized Coal Burner Systems......Page 269
Fuel Preparation......Page 270
Overfire Air Systems as Burner-Based Emissions Control......Page 272
Basic Description and Identification of Types......Page 273
Design and Operating Parameters......Page 274
Concluding Statements......Page 276
References......Page 277
Introduction......Page 280
Fluidized-Bed Combustion Systems......Page 281
Bubbling Fluidized-Bed Combustion (BFBC)......Page 283
Circulating Fluidized-Bed Combustion (CFBC)......Page 285
Pressurized Fluidized-Bed Combustion (PFBC)......Page 287
Heat Transfer......Page 288
Fuel Flexibility......Page 289
Pollutant Formation and Control......Page 293
Transformation of Sorbents in the FBC Process......Page 294
Bed Temperature......Page 296
Combustor Pressure......Page 297
Porosity......Page 298
Particle Size......Page 299
NOx Formation......Page 300
Combustion Temperature......Page 301
NOx Reduction Techniques......Page 302
Carbon Monoxide/Hydrocarbons......Page 303
Trace Elements......Page 304
Ash Chemistry and Agglomeration Issues......Page 306
Chemical Fractionation of Biomass......Page 308
Results of the Chemical Fractionation Study......Page 309
Thermodynamic Modeling to Predict Inorganic Phases......Page 316
Viscosity of Inorganic Melt Phases......Page 321
Viscosity Results......Page 324
Conclusions......Page 325
FBC Boilers and Their Role in Clean Coal Technology Development......Page 326
Clean Coal Technology Development Program (CCTDP)......Page 327
Worldwide......Page 329
Unique Opportunities for FBCs......Page 330
Background of Opportunity/Food Industry Issue......Page 331
Disposal Options......Page 333
Summary of ATB/Coal Cofiring in a Pilot-Scale Fluidized-Bed Combustor......Page 334
NCBA/Cargill Food Solutions Tests......Page 335
DOE Oxygen-Enhanced Combustion Testing......Page 337
References......Page 338
Introduction......Page 346
Introduction......Page 347
Collection......Page 348
Equipment Arrangement......Page 350
Resistivity......Page 351
Process Control......Page 352
Operating an Electrostatic Precipitator......Page 356
Excess Air......Page 358
Stack Gas Temperature......Page 359
Coal Chemistry......Page 360
Diagnostics......Page 361
Resistivity Conditioning......Page 365
Overview......Page 366
Basic Principles......Page 367
Shaker Design......Page 368
Reverse-Air Design......Page 369
Collection Efficiency......Page 370
Acid Gases of Importance: SO2, HCl......Page 371
Typical Designs/Scale of Operations......Page 372
Typical Designs/Scale of Operation......Page 374
Efficiencies......Page 375
Basic Principles......Page 376
Reactions......Page 377
Kinetics and Thermodynamics......Page 379
Introduction......Page 381
Selective Noncatalytic Reduction (SNCR)......Page 382
System Designs......Page 383
Catalyst Types......Page 384
Mercury Emissions from Existing Control Technologies from Coal-Fired Power Plants......Page 385
Technologies for Mercury Control......Page 388
Overview of Powdered Activated Carbon Injection for Mercury Control......Page 389
Balance-of-Plant Issues......Page 392
Wet Flue Gas Desulfurization......Page 393
Post-Combustion Carbon Dioxide Scrubbing......Page 394
References......Page 395
Introduction......Page 397
Analytical Modeling......Page 398
Background......Page 400
Identify Current Fuels Opportunities......Page 401
Validate Objectives and Develop Effective Design......Page 403
Successfully Applying Computer Technology to Fuels Control......Page 407
AccuTrack Situation Challenges and Response......Page 412
Discrete Element Modeling (DEM)......Page 414
Stochastic Model......Page 415
Bunker Geometry......Page 416
Validation of Bunker Modeling......Page 419
Conclusions Regarding the AccuTrack Approach to Computer Management of Fuel Properties......Page 424
Summary......Page 425
Introduction to Gasification......Page 426
Gasification Theory......Page 427
Bed Type......Page 430
Other Configurations and Processes......Page 432
Feed Preparation......Page 433
Operating Temperature......Page 434
Oxidant......Page 435
Primary Syngas Cooling......Page 436
Fuel Issues......Page 438
Shell......Page 439
Siemens (formerly Future Energy GSP)......Page 442
KBR Transport Gasifier......Page 444
Lurgi......Page 445
Sulfur Compounds......Page 446
Oxygen......Page 447
Mercury......Page 448
Introduction......Page 449
Desulfurization......Page 450
Physical Washes......Page 451
Selexol......Page 452
Rectisol......Page 453
COS Hydrolysis......Page 456
CO Shift......Page 457
High-Temperature (HT) Shift......Page 458
Raw Gas Shift......Page 459
Integrated Gasification-Combined Cycle (IGCC)......Page 460
Gasification Block......Page 462
Gas Treatment and Sulfur Recovery......Page 463
Combined Cycle Power Plant......Page 464
Methanol......Page 465
Environmental Impact......Page 467
Start-up Emissions......Page 468
Capital Requirements......Page 469
References......Page 470
Introduction......Page 472
Combustion Engineers Do Not Make Policy......Page 474
Combustion Engineers Respond to Policy......Page 475
Environmental Policy and the Engineering Response......Page 476
Environmental Policy and Legislation Since 1990......Page 477
Mechanisms of Engineering Response to Environmental Policy......Page 480
Energy Policy and Combustion Engineering......Page 483
Deregulation and Its Precursors......Page 484
Other Federal, State, Local, and Private Policies Impacting Combustion Engineers......Page 485
References......Page 487
Index......Page 488