Distillation Troubleshooting

by Kister, Henry Z.

• ISBN13: 9780471690726
• ISBN10: 0471690724
• Edition: 1st
• Format: eBook
• Copyright: 2010-08-26
• Publisher: Wiley-AIChE

Summary

THE FIRST BOOK OF ITS KIND ON DISTILLATION TECHNOLOGY

The last half-century of research on distillation has tremendously improved our understanding and design of industrial distillation equipment and systems. High-speed computers have taken over the design, control, and operation of towers. Invention and innovation in tower internals have greatly enhanced tower capacity and efficiency. With all these advances, one would expect the failure rate in distillation towers to be on the decline. In fact, the opposite is the case: the tower failure rate is on the rise and accelerating.

Distillation Troubleshooting collects invaluable hands-on experiences acquired in dealing with distillation and absorption malfunctions, making them readily accessible for those engaged in solving today's problems and avoiding tomorrow's. The first book of its kind on the distillation industry, the practical lessons it offers are a must for those seeking the elusive path to trouble-free distillation.

Distillation Troubleshooting covers over 1,200 case histories of problems, diagnoses, solutions, and key lessons. Coverage includes:
* Successful and unsuccessful struggles with plugging, fouling, and coking
* Histories and prevention of tray, packing, and internals damage
* Lessons taught by incidents and accidents during shutdowns, commissioning, and abnormal operation
* Troubleshooting distillation simulations to match the real world
* Making packing liquid distributors work
* Plant bottlenecks from intermediate draws, chimney trays, and feed points
* Histories of and key lessons from explosions and fires in distillation towers
* Prevention of flaws that impair reboiler and condenser performance
* Destabilization of tower control systems and how to correct it
* Discoveries from shutdown inspections
* Suppression of foam and accumulation incidents

A unique resource for improving the foremost industrial separation process, Distillation Troubleshooting transforms decades of hands-on experiences into a handy reference for professionals and students involved in the operation, design, study, improvement, and management of large-scale distillation.

Author Biography

Henry Z. Kister is a Senior Fellow and director of fractionation technology at Fluor Corporation. He has 30 years of experience in troubleshooting, revamping, field consulting, design, control, and startup of fractionation processes and equipment. Previously, he was Brown & Root's staff consultant on fractionation and also worked for ICI Australia and Fractionation research, Inc. (FRI). He is the author of the textbooks Distillation Design and Distillation Operation, as well as 80 published technical articles, and has taught the IChemE-sponsored "Practical Distillation Technology" Course more than 260 times. A recipient of Chemical Engineering magazine 2002 award for personal achievement in chemical engineering, and of the technology, Kister obtained his BE and ME degrees from the University of NSW in Australia. he is a Fellow of IChyemE, a Member of the AICHE, and serves on the FRI Technical Advisory and Design Practices Committees.

Table of Contents

Preface	p. xxiii
Acknowledgments	p. xxvii
How to Use this Book	p. xxix
Abbreviations	p. xxxi
Distillation Troubleshooting Database of Published Case Histories
Troubleshooting Distillation Simulations	p. 398
VLE	p. 398
Close-Boiling Systems	p. 398
Nonideal Systems	p. 399
Nonideality Predicted in Ideal System	p. 400
Nonideal VLE Extrapolated to Pure Products	p. 400
Nonideal VLE Extrapolated to Different Pressures	p. 401
Incorrect Accounting for Association Gives Wild Predictions	p. 401
Poor Characterization of Petroleum Fractions	p. 402
Chemistry, Process Sequence	p. 402
Does Your Distillation Simulation Reflect the Real World?	p. 404
General	p. 404
With Second Liquid Phase	p. 406
Refinery Vacuum Tower Wash Sections	p. 406
Modeling Tower Feed	p. 406
Simulation/Plant Data Mismatch Can Be Due to an Unexpected Internal Leak	p. 406
Simulation/Plant Data Mismatch Can Be Due to Liquid Entrainment in Vapor Draw	p. 407
Bug in Simulation	p. 407
Graphical Techniques to Troubleshoot Simulations	p. 407
McCabe-Thiele and Hengstebeck Diagrams	p. 407
Multicomponent Composition Profiles	p. 407
Residue Curve Maps	p. 407
How Good Is Your Efficiency Estimate?	p. 407
Simulator Hydraulic Predictions: To Trust or Not to Trust	p. 409
Do Your Vapor and Liquid Loadings Correctly Reflect Subcool, Superheat, and Pumparounds?	p. 409
How Good Are the Simulation Hydraulic Prediction Correlations?	p. 409
Where Fractionation Goes Wrong	p. 410
Insufficient Reflux or Stages; Pinches	p. 410
No Stripping in Stripper	p. 412
Unique Features of Multicomponent Distillation	p. 412
Accumulation and Hiccups	p. 413
Intermediate Component, No Hiccups	p. 413
Intermediate Component, with Hiccups	p. 414
Lights Accumulation	p. 416
Accumulation between Feed and Top or Feed and Bottom	p. 417
Accumulation by Recycling	p. 418
Hydrates, Freeze-Ups	p. 418
Two Liquid Phases	p. 419
Azeotropic and Extractive Distillation	p. 421
Problems Unique to Azeotroping	p. 421
Problems Unique to Extractive Distillation	p. 423
Energy Savings and Thermal Effects	p. 424
Energy-Saving Designs and Operation	p. 424
Excess Preheat and Precool	p. 424
Side-Reboiler Problems	p. 424
Bypassing a Feed around the Tower	p. 424
Reducing Recycle	p. 425
Heat Integration Imbalances	p. 426
Subcooling: How It Impacts Towers	p. 428
Additional Internal Condensation and Reflux	p. 428
Less Loadings above Feed	p. 429
Trapping Lights and Quenching	p. 429
Others	p. 430
Superheat: How It Impacts Towers	p. 430
Tower Sizing and Material Selection Affect Performance	p. 431
Undersizing Trays and Downcomers	p. 431
Oversizing Trays	p. 431
Tray Details Can Bottleneck Towers	p. 433
Low Liquid Loads Can Be Troublesome	p. 434
Loss of Downcomer Seal	p. 434
Tray Dryout	p. 435
Special Bubble-Cap Tray Problems	p. 436
Misting	p. 437
Undersizing Packings	p. 437
Systems Where Packings Perform Different from Expectations	p. 437
Packed Bed Too Long	p. 438
Packing Supports Can Bottleneck Towers	p. 439
Packing Hold-downs Are Sometimes Troublesome	p. 440
Internals Unique to Packed Towers	p. 440
Empty (Spray) Sections	p. 440
Feed Entry Pitfalls in Tray Towers	p. 441
Does the Feed Enter the Correct Tray?	p. 441
Feed Pipes Obstructing Downcomer Entrance	p. 441
Feed Flash Can Choke Downcomers	p. 441
Subcooled Feeds, Refluxes Are Not Always Trouble Free	p. 442
Liquid and Unsuitable Distributors Do Not Work with Flashing Feeds	p. 442
Flashing Feeds Require More Space	p. 443
Uneven or Restrictive Liquid Split to Multipass Trays at Feeds and Pass Transitions	p. 443
Oversized Feed Pipes	p. 444
Plugged Distributor Holes	p. 444
Low [Delta]P Trays Require Decent Distribution	p. 445
Packed-Tower Liquid Distributors: Number 6 on the Top 10 Malfunctions	p. 446
Better Quality Distributors Improve Performance	p. 446
Original Distributor Orifice or Unspecified	p. 446
Original Distributor Weir Type	p. 447
Original Distributor Spray Type	p. 447
Plugged Distributors Do Not Distribute Well	p. 448
Pan/Trough Orifice Distributors	p. 448
Pipe Orifice Distributors	p. 449
Spray Distributors	p. 450
Overflow in Gravity Distributors: Death to Distribution	p. 451
Feed Pipe Entry and Predistributor Problems	p. 454
Poor Flashing Feed Entry Bottleneck Towers	p. 455
Oversized Weep Holes Generate Undesirable Distribution	p. 456
Damaged Distributors Do Not Distribute Well	p. 457
Broken Flanges or Missing Spray Nozzles	p. 457
Others	p. 457
Hole Pattern and Liquid Heads Determine Irrigation Quality	p. 458
Gravity Distributors Are Meant to Be Level	p. 459
Hold-Down Can Interfere with Distribution	p. 460
Liquid Mixing Is Needed in Large-Diameter Distributors	p. 460
Notched Distributors Have Unique Problems	p. 461
Others	p. 461
Vapor Maldistribution in Trays and Packings	p. 462
Vapor Feed/Reboiler Return Maldistributes Vapor to Packing Above	p. 462
Chemical/Gas Plant Packed Towers	p. 462
Packed Refinery Main Fractionators	p. 463
Experiences with Vapor Inlet Distribution Baffles	p. 465
Packing Vapor Maldistribution at Intermediate Feeds and Chimney Trays	p. 465
Vapor Maldistribution Is Detrimental in Tray Towers	p. 466
Vapor Cross-Flow Channeling	p. 466
Multipass Trays	p. 467
Others	p. 467
Tower Base Level and Reboiler Return: Number 2 on the Top 10 Malfunctions	p. 468
Causes of High Base Level	p. 468
Faulty Level Measurement or Level Control	p. 468
Operation	p. 469
Excess Reboiler Pressure Drop	p. 470
Undersized Bottom Draw Nozzle or Bottom Line	p. 470
Others	p. 470
High Base Level Causes Premature Tower Flood (No Tray/Packing Damage)	p. 470
High Base Liquid Level Causes Tray/Packing Damage	p. 471
Impingement by the Reboiler Return Inlet	p. 472
On Liquid Level	p. 472
On Instruments	p. 473
On Tower Wall	p. 473
Opposing Reboiler Return Lines	p. 474
On Trays	p. 474
On Seal Pan Overflow	p. 474
Undersized Bottom Feed Line	p. 475
Low Base Liquid Level	p. 475
Issues with Tower Base Baffles	p. 476
Vortexing	p. 476
Chimney Tray Malfunctions: Part of Number 7 on the Top 10 Malfunctions	p. 477
Leakage	p. 477
Problem with Liquid Removal, Downcomers, or Overflows	p. 478
Thermal Expansion Causing Warping, Out-of-Levelness	p. 479
Chimneys Impeding Liquid Flow to Outlet	p. 480
Vapor from Chimneys Interfering with Incoming Liquid	p. 480
Level Measurement Problems	p. 481
Coking, Fouling, Freezing	p. 482
Other Chimney Tray Issues	p. 482
Drawoff Malfunctions (Non-Chimney Tray): Part of Number 7 on the Top 10 Malfunctions	p. 484
Vapor Chokes Liquid Draw Lines	p. 484
Insufficient Degassing	p. 484
Excess Line Pressure Drop	p. 485
Vortexing	p. 486
Leak at Draw Tray Starves Draw	p. 486
Draw Pans and Draw Lines Plug Up	p. 488
Draw Tray Damage Affects Draw Rates	p. 488
Undersized Side-Stripper Overhead Lines Restrict Draw Rates	p. 488
Degassed Draw Pan Liquid Initiates Downcomer Backup Flood	p. 489
Other Problems with Tower Liquid Draws	p. 489
Liquid Entrainment in Vapor Side Draws	p. 490
Reflux Drum Malfunctions	p. 490
Reflux Drum Level Problems	p. 490
Undersized or Plugged Product Lines	p. 490
Two Liquid Phases	p. 490
Tower Assembly Mishaps: Number 5 on the Top 10 Malfunctions	p. 491
Incorrect Tray Assembly	p. 491
Downcomer Clearance and Inlet Weir Malinstallation	p. 491
Flow Passage Obstruction and Internals Misorientation at Tray Tower Feeds and Draws	p. 492
Leaking Trays and Accumulator Trays	p. 493
Bolts, Nuts, Clamps	p. 493
Manways/Hatchways Left Unbolted	p. 493
Materials of Construction Inferior to Those Specified	p. 494
Debris Left in Tower or Piping	p. 494
Packing Assembly Mishaps	p. 495
Random	p. 495
Structured	p. 496
Grid	p. 496
Fabrication and Installation Mishaps in Packing Distributors	p. 496
Parts Not Fitting through Manholes	p. 498
Auxiliary Heat Exchanger Fabrication and Assembly Mishaps	p. 498
Auxiliary Piping Assembly Mishaps	p. 498
Difficulties during Start-Up, Shutdown, Commissioning, and Abnormal Operation: Number 4 on the Top 10 Malfunctions	p. 499
Blinding/Unblinding Lines	p. 499
Backflow	p. 500
Dead-Pocket Accumulation and Release of Trapped Materials	p. 501
Purging	p. 501
Pressuring and Depressuring	p. 502
Washing	p. 502
On-Line Washes	p. 504
Steam and Water Operations	p. 506
Overheating	p. 506
Cooling	p. 507
Overchilling	p. 507
Water Removal	p. 508
Draining at Low Points	p. 508
Oil Circulation	p. 508
Condensation of Steam Purges	p. 508
Dehydration by Other Procedures	p. 508
Start-Up and Initial Operation	p. 509
Total-Reflux Operation	p. 509
Adding Components That Smooth Start-Up	p. 509
Siphoning	p. 509
Pressure Control at Start-Up	p. 510
Confined Space and Manhole Hazards	p. 510
Water-Induced Pressure Surges: Part of Number 3 on the Top 10 Malfunctions	p. 512
Water in Feed and Slop	p. 512
Accumulated Water in Transfer Line to Tower and in Heater Passes	p. 513
Water Accumulation in Dead Pockets	p. 513
Water Pockets in Pump or Spare Pump Lines	p. 514
Undrained Stripping Steam Lines	p. 515
Condensed Steam or Refluxed Water Reaching Hot Section	p. 516
Oil Entering Water-Filled Region	p. 517
Explosions, Fires, and Chemical Releases: Number 10 on the Top 10 Malfunctions	p. 518
Explosions Due to Decomposition Reactions	p. 518
Ethylene Oxide Towers	p. 518
Peroxide Towers	p. 519
Nitro Compound Towers	p. 520
Other Unstable-Chemical Towers	p. 521
Explosions Due to Violent Reactions	p. 523
Explosions and Fires Due to Line Fracture	p. 524
C[subscript 3]-C[subscript 4] Hydrocarbons	p. 524
Overchilling	p. 525
Water Freeze	p. 526
Other	p. 527
Explosions Due to Trapped Hydrocarbon or Chemical Release	p. 527
Explosions Induced by Commissioning Operations	p. 528
Packing Fires	p. 529
Initiated by Hot Work Above Steel Packing	p. 529
Pyrophoric Deposits Played a Major Role, Steel Packing	p. 530
Tower Manholes Opened While Packing Hot, Steel Packing	p. 532
Others, Steel Packing Fires	p. 532
Titanium, Zinconium Packing Fires	p. 533
Fires Due to Opening Tower before Cooling or Combustible Removal	p. 533
Fires Caused by Backflow	p. 534
Fires by Other Causes	p. 535
Chemical Releases by Backflow	p. 536
Trapped Chemicals Released	p. 536
Relief, Venting, Draining, Blowdown to Atmosphere	p. 537
Undesired Reactions in Towers	p. 539
Excessive Bottom Temperature/Pressure	p. 539
Hot Spots	p. 539
Concentration or Entry of Reactive Chemical	p. 539
Chemicals from Commissioning	p. 540
Catalyst Fines, Rust, Tower Materials Promote Reaction	p. 540
Long Residence Times	p. 541
Inhibitor Problems	p. 541
Air Leaks Promote Tower Reactions	p. 542
Impurity in Product Causes Reaction Downstream	p. 542
Foaming	p. 543
What Causes or Promotes Foaming?	p. 543
Solids, Corrosion Products	p. 543
Corrosion and Fouling Inhibitors, Additives, and Impurities	p. 544
Hydrocarbon Condensation into Aqueous Solutions	p. 545
Wrong Filter Elements	p. 546
Rapid Pressure Reduction	p. 546
Proximity to Solution Plait Point	p. 546
What Are Foams Sensitive To?	p. 546
Feedstock	p. 546
Temperature	p. 547
Pressure	p. 547
Laboratory Tests	p. 547
Sample Shake, Air Bubbling	p. 547
Oldershaw Column	p. 547
Foam Test Apparatus	p. 548
At Plant Conditions	p. 548
Antifoam Injection	p. 548
Effective Only at the Correct Quantity/Concentration	p. 548
Some Antifoams Are More Effective Than Others	p. 549
Batch Injection Often Works, But Continuous Can Be Better	p. 549
Correct Dispersal Is Important, Too	p. 550
Antifoam Is Sometimes Adsorbed on Carbon Beds	p. 550
Other Successful Antifoam Experiences	p. 550
Sometimes Antifoam Is Less Effective	p. 551
System Cleanup Mitigates Foaming	p. 551
Improving Filtration	p. 551
Carbon Beds Mitigate Foaming But Can Adsorb Antifoam	p. 553
Removing Hydrocarbons from Aqueous Solvents	p. 553
Changing Absorber Solvent	p. 553
Other Contaminant Removal Techniques	p. 554
Hardware Changes Can Debottleneck Foaming Towers	p. 555
Larger Downcomers	p. 555
Smaller Downcomer Backup (Lower Pressure Drop, Larger Clearances)	p. 556
More Tray Spacing	p. 556
Removing Top Two Trays Does Not Help	p. 556
Trays Versus Packings	p. 556
Larger Packings, High-Open-Area Distributors Help	p. 557
Increased Agitation	p. 557
Larger Tower	p. 557
Reducing Base Level	p. 557
The Tower as a Filter: Part A. Causes of Plugging-Number 1 on the Top 10 Malfunctions	p. 558
Piping Scale/Corrosion Products	p. 558
Salting Out/Precipitation	p. 559
Polymer/Reaction Products	p. 560
Solids/Entrainment in the Feed	p. 561
Oil Leak	p. 561
Poor Shutdown Wash/Flush	p. 562
Entrainment or Drying at Low Liquid Rates	p. 562
Others	p. 562
The Tower as a Filter: Part B. Locations of Plugging-Number 1 on the Top 10 Malfunctions	p. 563
Trays	p. 563
Downcomers	p. 564
Packings	p. 565
How Packings and Trays Compare on Plugging Resistance	p. 565
Trays versus Trays	p. 565
Trays versus Packings	p. 566
Packings versus Packings	p. 567
Limited Zone Only	p. 567
Draw, Exchanger, and Vent Lines	p. 569
Feed and Inlet Lines	p. 570
Instrument Lines	p. 570
Coking: Part of Number 1 on Tower Top 10 Malfunctions	p. 571
Insufficient Wash Flow Rate, Refinery Vacuum Towers	p. 571
Other Causes, Refinery Vacuum Towers	p. 572
Slurry Section, FCC Fractionators	p. 573
Other Refinery Fractionators	p. 574
Nonrefinery Fractionators	p. 574
Leaks	p. 575
Pump, Compressor	p. 575
Heat Exchanger	p. 575
Reboiler Tube	p. 575
Condenser Tube	p. 576
Auxiliary Heat Exchanger (Preheater, Pumparound)	p. 576
Chemicals to/from Other Equipment	p. 577
Leaking from Tower	p. 577
Leaking into Tower	p. 577
Product to Product	p. 578
Atmospheric	p. 578
Chemicals to Atmosphere	p. 578
Air into Tower	p. 579
Relief and Failure	p. 580
Relief Requirements	p. 580
Controls That Affect Relief Requirements and Frequency	p. 580
Relief Causes Tower Damage, Shifts Deposits	p. 581
Overpressure Due to Component Entry	p. 581
Relief Protection Absent or Inadequate	p. 582
Line Ruptures	p. 583
All Indication Lost When Instrument Tap Plugged	p. 584
Trips Not Activating or Incorrectly Set	p. 584
Pump Failure	p. 585
Loss of Vacuum	p. 585
Power Loss	p. 585
Tray, Packing, and Tower Damage: Part of Number 3 on the Top 10 Malfunctions	p. 586
Vacuum	p. 586
Insufficient Uplift Resistance	p. 587
Uplift Due to Poor Tightening during Assembly	p. 587
Uplift Due to Rapid Upward Gas Surge	p. 589
Valves Popping Out	p. 590
Downward Force on Trays	p. 590
Trays below Feed Bent Up, above Bent Down and Vice Versa	p. 591
Downcomers Compressed, Bowed, Fallen	p. 592
Uplift of Cartridge Trays	p. 593
Flow-Induced Vibrations	p. 593
Compressor Surge	p. 594
Packing Carryover	p. 595
Melting, Breakage of Plastic Packing	p. 595
Damage to Ceramic Packing	p. 595
Damage to Other Packings	p. 595
Reboilers That Did Not Work: Number 9 on the Top 10 Malfunctions	p. 596
Circulating Thermosiphon Reboilers	p. 596
Excess Circulation	p. 596
Insufficient Circulation	p. 596
Insufficient [Delta]T, Pinching	p. 596
Surging	p. 596
Velocities Too Low in Vertical Thermosiphons	p. 597
Problems Unique to Horizontal Thermosiphons	p. 597
Once-Through Thermosiphon Reboilers	p. 597
Leaking Draw Tray or Draw Pan	p. 597
No Vaporization/Thermosiphon	p. 598
Slug Flow in Outlet Line	p. 599
Forced-Circulation Reboilers	p. 599
Kettle Reboilers	p. 599
Excess [Delta]P in Circuit	p. 599
Poor Liquid Spread	p. 601
Liquid Level above Overflow Baffle	p. 602
Internal Reboilers	p. 602
Kettle and Thermosiphon Reboilers in Series	p. 603
Side Reboilers	p. 603
Inability to Start	p. 603
Liquid Draw and Vapor Return Problems	p. 603
Hydrates	p. 603
Pinching	p. 604
Control Issues	p. 604
All Reboilers, Boiling Side	p. 604
Debris/Deposits in Reboiler Lines	p. 604
Undersizing	p. 604
Film Boiling	p. 604
All Reboilers, Condensing Side	p. 605
Non condensables in Heating Medium	p. 605
Loss of Condensate Seal	p. 605
Condensate Draining Problems	p. 606
Vapor/Steam Supply Bottleneck	p. 606
Condensers That Did Not Work	p. 607
Inerts Blanketing	p. 607
Inadequate Venting	p. 607
Excess Lights in Feed	p. 608
Inadequate Condensate Removal	p. 608
Undersized Condensate Lines	p. 608
Exchanger Design	p. 609
Unexpected Condensation Heat Curve	p. 609
Problems with Condenser Hardware	p. 610
Maldistribution between Parallel Condensers	p. 611
Flooding/Entrainment in Partial Condensers	p. 611
Interaction with Vacuum and Recompression Equipment	p. 612
Others	p. 612
Misleading Measurements: Number 8 on the Top 10 Malfunctions	p. 613
Incorrect Readings	p. 613
Meter or Taps Fouled or Plugged	p. 614
Missing Meter	p. 615
Incorrect Meter Location	p. 615
Problems with Meter and Meter Tubing Installation	p. 616
Incorrect Meter Installation	p. 616
Instrument Tubing Problems	p. 616
Incorrect Meter Calibration, Meter Factor	p. 617
Level Instrument Fooled	p. 617
By Froth or Foam	p. 617
By Oil Accumulation above Aqueous Level	p. 618
By Lights	p. 619
By Radioactivity (Nucleonic Meter)	p. 619
Interface-Level Metering Problems	p. 619
Meter Readings Ignored	p. 619
Electric Storm Causes Signal Failure	p. 619
Control System Assembly Difficulties	p. 620
No Material Balance Control	p. 620
Controlling Two Temperatures/Compositions Simultaneously Produces Interaction	p. 621
Problems with the Common Control Schemes, No Side Draws	p. 622
Boil-Up on TC/AC, Reflux on FC	p. 622
Boil-Up on FC, Reflux on TC/AC	p. 623
Boil-Up on FC, Reflux on LC	p. 624
Boil-Up on LC, Bottoms on TC/AC	p. 625
Reflux on Base LC, Bottoms on TC/AC	p. 626
Problems with Side-Draw Controls	p. 626
Small Reflux below Liquid Draw Should Not Be on Level or Difference Control	p. 626
Incomplete Material Balance Control with Liquid Draw	p. 628
Steam Spikes with Liquid Draw	p. 628
Internal Vapor Control makes or Breaks Vapor Draw Control	p. 628
Others	p. 628
Where Do Temperature and Composition Controls Go Wrong?	p. 629
Temperature Control	p. 629
No Good Temperature Control Tray	p. 629
Best Control Tray	p. 630
Fooling by Nonkeys	p. 630
Averaging (Including Double Differential)	p. 631
Azeotropic Distillation	p. 631
Extractive Distillation	p. 631
Other	p. 632
Pressure-Compensated Temperature Controls	p. 632
[Delta]T Control	p. 632
Other Pressure Compensation	p. 633
Analyzer Control	p. 633
Obtaining a Valid Analysis for Control	p. 633
Long Lags and High Off-Line Times	p. 633
Intermittent Analysis	p. 634
Handling Feed Fluctuations	p. 635
Analyzer-Temperature Control Cascade	p. 635
Analyzer On Next Tower	p. 635
Misbehaved Pressure, Condenser, Reboiler, and Preheater Controls	p. 636
Pressure Controls by Vapor Flow Variations	p. 636
Flooded Condenser Pressure Controls	p. 637
Valve in the Condensate, Unflooded Drum	p. 637
Flooded Drum	p. 637
Hot-Vapor Bypass	p. 637
Valve in the Vapor to the Condenser	p. 639
Coolant Throttling Pressure Controls	p. 640
Cooling-Water Throttling	p. 640
Manipulating Airflow	p. 640
Steam Generator Overhead Condenser	p. 640
Controlling Cooling-Water Supply Temperature	p. 640
Pressure Control Signal	p. 641
From Tower or from Reflux Drum?	p. 641
Controlling Pressure via Condensate Temperature	p. 641
Throttling Steam/Vapor to Reboiler or Preheater	p. 641
Throttling Condensate from Reboiler	p. 642
Preheater Controls	p. 643
Miscellaneous Control Problems	p. 644
Interaction with the Process	p. 644
[Delta]P Control	p. 644
Flood Controls and Indicators	p. 644
Batch Distillation Control	p. 645
Problems in the Control Engineer's Domain	p. 645
Advanced Controls Problems	p. 646
Updating Multivariable Controls	p. 646
Advanced Controls Fooled by Bad Measurements	p. 646
Issues with Model Inaccuracies	p. 647
Effect of Power Dips	p. 647
Experiences with Composition Predictors in Multivariable Controls	p. 647
References	p. 649
Index	p. 669
About the Author	p. 713
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