Thermal Safety of Chemical Processes: Risk Assessment and Process Design

Cover......Page 1
Title Page......Page 5
Copyright......Page 6
Contents......Page 9
Preface......Page 23
Acknowledgments......Page 27
Part I General Aspects of Thermal Process Safety......Page 29
 Chapter 1 Introduction to Risk Analysis of Fine Chemical Processes......Page 31
    1.1.1.1 Product Safety......Page 32
    1.1.1.3 Accidents and Risk Perception in Chemical Industry......Page 33
   1.1.2 Responsibility......Page 34
    1.1.3.2 Risk......Page 35
  1.2 Steps of Risk Analysis......Page 36
   1.2.1 Scope of Analysis......Page 37
   1.2.4 Identification of Deviations......Page 38
   1.2.5 Risk Assessment......Page 39
   1.2.6 Risk Matrixes......Page 42
   1.2.7 Risk‐Reducing Measures......Page 43
  1.3 Safety Data......Page 45
   1.3.3 Toxicity......Page 46
   1.3.5 Fire and Explosion Data......Page 48
  1.4 Systematic Identification of Hazards......Page 49
   1.4.1 Checklist Method......Page 50
   1.4.3 Hazard and Operability Study......Page 52
   1.4.5 Event Tree Analysis......Page 54
   1.4.6 Fault Tree Analysis......Page 55
   1.5.1 Preparing the Risk Analysis......Page 57
   1.5.3 The Team Leader......Page 58
  1.6 Exercises......Page 59
  References......Page 60
 Chapter 2 Fundamentals of Thermal Process Safety......Page 63
    2.1.1.1 Heat of Reaction......Page 65
    2.1.1.2 Heat of Decomposition......Page 66
    2.1.1.3 Heat Capacity......Page 67
    2.1.1.4 Adiabatic Temperature Rise......Page 68
   2.2.1 Single Reaction......Page 69
   2.2.2 Multiple Reactions......Page 70
    2.3.1.1 Heat Production......Page 71
    2.3.1.2 Heat Removal......Page 72
    2.3.1.4 Convective Heat Exchange Due to Mass Flow......Page 74
    2.3.1.7 Heat Losses......Page 75
   2.3.2 Simplified Expression of the Heat Balance......Page 76
   2.3.3 Reaction Rate Under Adiabatic Conditions......Page 77
   2.4.1 Thermal Explosions......Page 78
   2.4.2 Semenov Diagram......Page 79
   2.4.3 Parametric Sensitivity......Page 80
   2.4.4 Critical Temperature......Page 81
   2.4.5 Sensitivity Toward Variation of the Coolant Temperature......Page 83
   2.4.6 Time Frame of a Thermal Explosion, the tmrad Concept......Page 84
  2.5 Exercises......Page 85
  References......Page 87
 Chapter 3 Assessment of Thermal Risks......Page 89
   3.1.2 Processes Concerned by Thermal Risks......Page 90
   3.2.1 Cooling Failure Scenario......Page 91
   3.2.2 Severity......Page 94
   3.2.3 Probability......Page 96
   3.3.1 Assessment of the Criticality......Page 98
    3.3.2.2 Criticality Class 2......Page 100
    3.3.2.5 Criticality Class 5......Page 101
   3.3.4 Remarks on Criticality Class 5......Page 104
   3.3.5 Using MTT as a Safety Barrier......Page 105
   3.4.2 Practical Procedure for the Assessment of Thermal Risks......Page 109
  Second Step: Data Measurement......Page 110
  3.5 Exercises......Page 113
  References......Page 115
 Chapter 4 Experimental Techniques......Page 117
   4.1.2 Temperature Control Modes of Calorimeters......Page 118
    4.1.2.3 Adiabatic......Page 119
   4.1.3 Heat Balance in Calorimeters......Page 120
    4.1.3.2 Ideal Heat Flow......Page 121
    4.2.1.1 Sample Mass......Page 122
    4.2.1.4 Calorimetric Cells for Safety Studies......Page 124
   4.3.1 Differential Scanning Calorimetry (DSC)......Page 125
    4.3.1.2 DSC and Safety Studies......Page 126
    4.3.1.3 DSC Crucibles......Page 127
    4.3.1.4 Applications......Page 128
    4.3.1.5 Sample Preparation......Page 130
    4.3.1.6 The Baseline Problem......Page 131
    4.3.2.1 Principle......Page 132
    4.3.2.2 Applications......Page 133
    4.3.3.1 Principle......Page 134
   4.4.1 Purpose of Reaction Calorimeters......Page 135
    4.4.2.1 Heat Flow Calorimeters......Page 136
    4.4.2.4 The Baseline Problem......Page 137
    4.4.3.1 RC1 by Mettler Toledo......Page 138
    4.4.3.6 Reaction Calorimetry at Microscale......Page 139
    4.4.4.1 Thermal Data of Reactions......Page 141
   4.5.1 Principle of Adiabatic Calorimetry......Page 142
   4.5.2 On the Thermal Inertia......Page 143
    4.5.3.1 Measurement Principle......Page 144
    4.5.3.2 Applications......Page 145
    4.5.4.1 Measurement Principle......Page 147
    4.5.4.2 Applications......Page 148
   4.5.5 Vent Sizing Package (VSP)......Page 149
  4.6 Exercises......Page 150
  References......Page 154
 Chapter 5 Assessment of the Energy Potential......Page 159
   5.1.1 Thermal Energy of Synthesis Reactions......Page 160
   5.1.2 Energy Potential of Secondary Reactions......Page 161
    5.1.2.2 Stoichiometry of Decomposition Reactions......Page 162
    5.1.2.4 Specific Problems Linked with Secondary Reactions......Page 163
   5.1.3 Adiabatic Temperature Rise......Page 164
   5.2.1 Gas Release......Page 165
   5.2.2 Vapor Pressure......Page 166
   5.2.3 Amount of Solvent Evaporated......Page 167
   5.3.1 Experimental Techniques......Page 168
    5.3.2.1 Sample Purity......Page 169
    5.3.2.2 Batch or Semi‐Batch Process......Page 170
    5.3.3.1 Effect of Charging Errors......Page 172
    5.3.3.3 Catalytic Effects of Impurities......Page 174
  5.4 Exercises......Page 175
  References......Page 177
Part II Mastering Exothermal Reactions......Page 181
 Chapter 6 General Aspects of Reactor Safety......Page 183
   6.1.2 Sensitivity Toward Temperature: Reaction Number B......Page 185
   6.1.3 Heat Balance......Page 186
    6.1.3.3 Heat Release Rate and Cooling Rate......Page 187
    6.1.3.4 Using Dimensionless Criteria......Page 188
    6.1.3.5 Chaos Theory and Lyapunov Exponents......Page 190
   6.2.1 Potential of the Reaction, the Adiabatic Temperature Rise......Page 191
   6.2.2 Temperature in Case of Cooling Failure: The Concept of MTSR......Page 192
  6.3 Example Reaction System......Page 193
  References......Page 196
 Chapter 7 Batch Reactors......Page 199
   7.1.1 Principles of Batch Reaction......Page 200
   7.1.2 Mass Balance......Page 201
   7.1.4 Strategies of Temperature Control......Page 202
   7.2.2 Design of Safe Isothermal Reactors......Page 203
   7.3.2 Design of a Safe Adiabatic Batch Reactor......Page 206
   7.4.1 Principles......Page 207
   7.4.2 Design of Polytropic Operation: Temperature Control......Page 208
   7.5.3 Safety Assessment......Page 212
   7.6.1 Principles......Page 213
   7.6.2 Design of Temperature‐Controlled Reaction......Page 214
   7.6.3 Safety Assessment......Page 215
   7.7.1 Determination of Safety Relevant Data......Page 216
   7.7.2 Rules for Safe Operation of Batch Reactors......Page 218
  7.8 Exercises......Page 221
  References......Page 223
 Chapter 8 Semi‐batch Reactors......Page 225
   8.1.1 Definition of Semi‐batch Operation......Page 226
   8.1.2 Material Balance......Page 227
    8.1.3.1 Heat Production......Page 228
    8.1.3.4 Heat Accumulation......Page 229
  8.2 Reactant Accumulation in Semi‐batch Reactors......Page 230
   8.2.1 Fast Reactions......Page 231
   8.2.2 Slow Reactions......Page 233
   8.2.3 Design of Safe Semi‐batch Reactors......Page 235
   8.3.2 Design of Isothermal Semi‐batch Reactors......Page 236
  8.4 Isoperibolic, Constant Cooling Medium Temperature......Page 240
  8.5 Non‐isothermal Reaction......Page 242
   8.6.2 Constant Feed Rate......Page 243
   8.6.3 Interlock of Feed with Temperature......Page 245
   8.7.1 General Principle......Page 247
   8.7.2 Scale‐Up from Laboratory to Industrial Scale......Page 248
   8.7.3 Online Detection of Unwanted Accumulation......Page 249
   8.8.1 Feed Control by the Accumulation......Page 250
   8.8.2 Feed Control by the Thermal Stability......Page 252
  8.9 Exercises......Page 254
  References......Page 256
 Chapter 9 Continuous Reactors......Page 259
  9.1 Continuous Stirred Tank Reactors......Page 260
   9.1.2 Heat Balance......Page 261
   9.1.4 Adiabatic CSTR......Page 262
   9.1.5 The Autothermal CSTR......Page 264
    9.1.6.2 Behavior in Case of Cooling Failure......Page 265
   9.2.1 Mass Balance......Page 268
   9.2.2 Heat Balance......Page 269
    9.2.3.1 Parametric Sensitivity......Page 270
    9.2.3.2 Heat Exchange Capacities of Tubular Reactors......Page 271
    9.2.3.3 Passive Safety Aspects of Tubular Reactors......Page 273
   9.2.4 Performance and Safety Characteristics of Ideal Reactors......Page 274
  9.3 Other Continuous Reactor Types......Page 275
   9.3.2 Recycling Reactor......Page 276
   9.3.3 Microreactors......Page 277
   9.3.4 Process Intensification......Page 279
  9.4 Exercises......Page 280
  References......Page 281
Part III Avoiding Secondary Reactions......Page 283
 Chapter 10 Thermal Stability......Page 285
  10.1 Thermal Stability and Secondary Decomposition Reactions......Page 286
   10.2.1 Onset: A Concept Without Scientific Base......Page 288
   10.2.2 Decomposition Kinetics, the tmrad Concept......Page 289
   10.2.4 Assessment Procedure......Page 290
   10.3.2 Conservative Extrapolation......Page 292
   10.3.3 Empirical Rules for the Determination of a “Safe” Temperature......Page 295
   10.3.4 Prediction of Thermal Stability......Page 296
   10.4.2 Determination of q′ = f(T) from Isothermal Experiments......Page 297
   10.4.3 Determination of q′ = f(T) from Dynamic Experiments......Page 301
   10.4.4 Determination of TD24......Page 303
   10.5.1 Complex Reactions......Page 304
  10.6 Exercises......Page 306
  References......Page 309
 Chapter 11 Autocatalytic Reactions......Page 311
    11.1.1.2 Induction Time......Page 312
   11.1.2 Behavior of Autocatalytic Reactions......Page 313
   11.1.3 Rate Equations of Autocatalytic Reactions......Page 314
    11.1.3.1 The Prout–Tompkins Model......Page 315
    11.1.3.3 The Berlin Model......Page 316
   11.1.4 Phenomenological Aspects of Autocatalytic Reactions......Page 317
   11.2.1 Chemical Information......Page 319
   11.2.2 Qualitative Peak Shape in a Dynamic DSC Thermogram......Page 320
   11.2.3 Quantitative Peak Shape Characterization......Page 321
   11.2.4 Double Scan Test......Page 322
   11.3.1 One‐Point Estimation......Page 324
   11.3.2 Characterization Using Zero‐Order Kinetics......Page 325
   11.3.3 Characterization Using a Mechanistic Approach......Page 327
   11.3.4 Characterization by Isoconversional Methods......Page 329
   11.3.5 Characterization by Adiabatic Calorimetry......Page 330
   11.4.1 Specific Safety Aspects of Autocatalytic Reactions......Page 334
   11.4.3 Volatile Products as Catalysts......Page 335
  11.5 Exercises......Page 336
  References......Page 337
 Chapter 12 Heat Accumulation......Page 339
  12.1 Heat Accumulation Situations......Page 340
  12.2 Heat Balance......Page 341
   12.2.2 Forced Convection, the Semenov Model......Page 342
   12.2.3 Natural Convection......Page 343
   12.2.4 High Viscosity Liquids, Pastes, and Solids......Page 344
   12.3.1 Conduction in a Reactive Solid with a Heat Source, the Frank‐Kamenetskii Model......Page 346
   12.3.2 Conduction in a Reactive Solid with Temperature Gradient at the Wall, the Thomas Model......Page 351
   12.3.3 Conduction in a Reactive Solid with Formal Kinetics, the Finite Elements Model......Page 352
   12.4.1 Thermal Explosion Models......Page 353
   12.4.2 Assessment Procedure......Page 354
  12.5 Exercises......Page 360
  References......Page 361
 Chapter 13 Physical Unit Operations......Page 363
   13.1.1 Introduction to Physical Unit Operations......Page 364
   13.1.3 Assessment Procedure for Unwanted Exothermal Reactions......Page 365
  13.2 Specific Testing Procedures......Page 366
   13.2.3 DSC Dynamic......Page 367
   13.2.5 Dynamic Decomposition Test (RADEX)......Page 368
    13.2.7.2 Test in Dewar......Page 369
   13.2.10 Self‐Ignition Test in a 400 ml Basket......Page 370
   13.3.2 Blending......Page 371
    13.3.4.1 Paddle Dryer......Page 372
   13.3.5 Milling and Grinding......Page 373
   13.4.1 Transport Operations......Page 374
   13.4.2 Operations with Heat Exchange......Page 375
   13.4.3 Evaporation and Distillation......Page 376
    13.4.3.2 Continuous Distillation......Page 377
   13.4.4 Failure Modes of Heat Exchangers and Evaporators......Page 378
   13.4.5 Risk Reducing Measures......Page 380
  13.5 Transport of Dangerous Goods and SADT......Page 381
  13.6 Exercises......Page 382
  References......Page 384
Part IV Technical Aspects of Thermal Process Safety......Page 385
 Chapter 14 Heating and Cooling Industrial Reactors......Page 387
    14.1.1.1 Steam Heating......Page 389
    14.1.1.2 Hot Water Heating......Page 390
    14.1.1.6 Other Heat Carriers for Cooling......Page 391
    14.1.2.2 Indirect Heating and Cooling......Page 392
    14.1.2.3 Single Heat Carrier Circulation Systems......Page 393
    14.1.3.1 Isoperibolic Temperature Control......Page 396
    14.1.3.3 Isothermal Control at Reflux......Page 397
    14.1.3.4 Non‐isothermal Temperature Control......Page 398
    14.1.4.1 Thermal Time Constant......Page 399
    14.1.4.2 Heating and Cooling Time......Page 401
    14.1.4.3 Cascade Controller......Page 402
   14.2.1 Two Film Theory......Page 403
   14.2.3 Determination of the Internal Film Coefficient......Page 404
   14.2.4 The Resistance of the Equipment to Heat Transfer......Page 406
   14.2.5 Practical Determination of Heat Transfer Coefficients......Page 407
  14.3 Evaporative Cooling......Page 410
   14.3.2 Vapor Flow Rate......Page 411
   14.3.3 Flooding of the Vapor Tube......Page 412
   14.3.4 Swelling of the Reaction Mass......Page 413
   14.3.5 Practical Procedure for the Assessment of Reactor Safety at the Boiling Point......Page 414
   14.4.1 Background......Page 416
   14.4.2 Modeling the Dynamic Behavior of Industrial Reactors......Page 417
   14.4.3 Experimental Simulation of Industrial Reactors......Page 418
  14.5 Exercises......Page 419
  References......Page 423
 Chapter 15 Risk Reducing Measures......Page 425
  15.1 Strategies of Choice......Page 427
  15.2 Eliminating Measures......Page 428
   15.3.1 Control of Feed......Page 429
   15.3.2 Emergency Cooling......Page 430
   15.3.3 Quenching and Flooding......Page 431
   15.3.4 Dumping......Page 432
   15.3.5 Controlled Depressurization......Page 433
   15.3.6 Alarm Systems......Page 434
   15.3.7 Time Factor......Page 435
   15.4.2 Containment......Page 436
    15.5.1.3 Release......Page 437
    15.5.1.5 Closed Vapor Systems......Page 438
    15.5.1.8 Extended Assessment Criteria for Severity......Page 439
    15.5.2.1 Activity of the Main Reaction......Page 440
    15.5.2.2 Activity of Secondary Reactions......Page 441
    15.5.2.4 Vapor Release Rate......Page 442
   15.5.3 Assessment of Severity and Probability for the Different Criticality Classes......Page 443
    15.5.3.3 Criticality Class 3......Page 444
    15.5.3.4 Criticality Class 4......Page 445
    15.5.3.5 Criticality Class 5......Page 446
  15.6 Exercises......Page 451
  References......Page 453
 Chapter 16 Emergency Pressure Relief......Page 455
   16.1.2 Regulatory Aspects......Page 457
    16.1.3.3 Combined Systems......Page 458
    16.1.3.4 Other Systems......Page 459
   16.2.1 Step 1: Definition of the Design Case......Page 460
    16.2.2.3 External Heating: Maximum Heating......Page 462
    16.2.2.5 Chemical Scenario with Gas Release......Page 463
   16.2.3 Step 2: Determination of the Flow Behavior......Page 465
    16.3.1.1 Mass Flow Rate for Vapor Relief with One‐Phase Flow......Page 467
    16.3.1.4 Mass Flow Rate for Hybrid Systems with Two‐Phase Flow......Page 468
    16.3.2.2 Two‐Phase Flow......Page 469
   16.3.3 Step 5 for Bursting Disk: Correction for Friction Losses......Page 470
   16.3.5 Step 5 for Safety Valve: Calculation of the Required Relief Area......Page 472
    16.3.6.2 Calculation of the Inlet Pressure Loss......Page 473
   16.4.1 Principle of Sizing Procedure......Page 474
   16.4.3 Sensitivity Analysis of the Design Data......Page 475
   16.4.4 Checking the Relief Capacity......Page 477
  16.5 Effluent Treatment......Page 478
   16.5.3 Passive Condenser......Page 479
  16.6 Exercises......Page 480
  References......Page 486
 Chapter 17 Reliability of Risk Reducing Measures......Page 489
    17.1.1.1 Process Control and Protection Systems......Page 491
    17.1.1.3 Failures......Page 492
   17.1.2 Failure Frequency......Page 493
   17.1.3 Failures on the Time Scale......Page 495
   17.2.2 Control Loops......Page 496
   17.3.1 Scenario Structure......Page 497
   17.3.2 Risk Matrix......Page 498
   17.3.3 Risk Reduction......Page 499
    17.3.4.1 The Calibrated Risk Graph......Page 501
  17.4 Exercises......Page 503
  References......Page 504
 Chapter 18 Development of Safe Processes......Page 507
   18.1.1 Principles of Inherent Safety......Page 508
   18.1.2 Safety Along Life Cycle of a Process......Page 510
   18.1.3 Developing a Safe Process......Page 511
   18.2.2 Integrated Process Development......Page 512
   18.3.1 Objectives and Data......Page 513
   18.3.2 Chemists and Engineers......Page 515
  18.4 Concluding Remark......Page 516
  References......Page 517
Solutions of Exercises......Page 519
Symbols......Page 557
Index......Page 565
EULA......Page 576