Process Engineering for a Small Planet

NORMAN P. LIEBERMAN is an independent process design engineer and field troubleshooter. His clients are refineries and petrochemical plants. He is well known in the process industry for his seminar "Troubleshooting Process Operations," which has been presented to over 16,000 engineers and plant operators.

• Foreword xvPreface xviiIntroduction: Turning of the Tide 11. Expanding Fractionator and Compressor Capacity 3Reuse of Existing FractionatorChanging Tray Deck PanelsAlternates to New CompressorKeeping Compressor Rotor CleanCalculating Liquid Injection Rates to Compressor2. Vacuum Tower Heater Expansion 17Entrainment Velocity LimitationsMissing Tray Deck ManwaysHeater Draft LimitationImproving Ejector PerformanceVelocity Steam in Heater Passes3. Natural-Draft-Fired Heaters 27Control Excess AirO2 and Combustible AnalyzersImproving Air–Fuel MixingConvective Section Air LeaksAir Preheater LeaksIndirect Air Preheat4. Crude Pre-Flash Towers 37Pre-Flash Tower FloodingEnergy Saving with Pre-Flash TowersCapacity BenefitsPre-Flash Tower External Reflux5. Amine Regeneration and Sulfur Recovery 47Amine Capacity ExpansionSulfur Plant Capacity ExpansionRich Amine Flash Drum DesignCascaded Seal LegsSulfur Recovery from Sour Water Stripper Off-GasAcid Gas of High CO2 ContentSulfur Plant Oxygen Enrichment6. Treating and Drying Hydrocarbons 59Jet Fuel TreatingSalt Dryer OperationWater-Washing Sodium Naphthanates from Jet FuelPipe Distributor DesignTreating Sour NaphthaConverting Mercaptans to Disulfides7. Minimizing Process Water Consumption 71Two-Stage Wastewater StripperSteam Condensate RecoveryCondensate Drum Balance Line LocationWater HammerMeasuring Condensate RecoveryCooling Tower Cycles of Concentration8. Incremental Expansion Design Concept: Reprocessing Waste Lube Oil 79Reprocessing Waste Lube OilVacuum Tower DesignWash Oil Grid CokingVapor Horn Design in Vacuum TowersStripping Tray EfficiencyPrecondenser FoulingPump NPSH Limit in Vacuum ServiceExchanger Fouling in Waste Oil ServiceTransfer-Line Sonic Velocity9. Improving Fractionation Efficiency in Complex Fractionators 91Pre-Flash Tower ConceptIntermediate RefluxStripping Tray EfficiencyMaximizing Diesel Recovery from CrudePicket WeirsAdjusting Pump-aroundsPressure Optimization10. Increasing Centrifugal Pump Capacity and Efficiency 103Hydraulic LimitationsWorn Impeller-to-Case ClearancesImpeller Wear RingUpgrading Impeller SizeMarginal CavitationViscosity Effects on EfficiencyNPSH Limited Condition11. Eliminating Process Control Valves Using Variable-Speed Drivers 113Frequency Control of MotorsEliminating Control Valves on Pump DischargeDirect Speed Control of Steam TurbineVariable-Speed CompressorsSpill-backs Waste EnergyCalculating Incentive for Variable-Speed DriversFloating Tower Pressure Control12. Expanding Refrigeration Capacity 123Centrifugal Compressor Head vs. Flow CurveCalculating Compression WorkHorsepower vs. Suction Pressure LimitedEffect of Increasing Suction PressureReducing Refrigerant Condenser FoulingEffect of NoncondensiblesCondensate Backup in Condenser13. Oversizing Equipment Pitfalls 135Amine H2 S ScrubberOptimizing Number of Trays in AbsorbersConsequences of OverdesignUse of Demister in Knockout DrumLow Demister Velocity Promotes Mist Entrainment14. Optimizing Use of Steam Pressure to Minimize Consumption of Energy 145Preserving the Potential of Steam to Do WorkPower Recovery from Steam to a ReboilerUse of the Mollier DiagramCogeneration PlantsExtracting Work from Reboiler Steam UsingExisting EquipmentUnderstanding Thermodynamics of Flowing SteamSteam Turbine Efficiency Checklist15. Expanding Compressor Capacity and Efficiency 157Reciprocating CompressorsPulsation Dampener PlatesAdjustable Head-End UnloadersNatural Gas EnginesAxial CompressorRotor Fouling of Axial Air CompressorCentrifugal CompressorsCleaning Centrifugal Compressor Rotor16. Vapor–Liquid Separator Entrainment Problems 171Effect of Foam on Indicated Liquid LevelsHydrogen-Heavy Gas Oil SepartorsFoam Induced Carry-OverEnhancing De-Entrainment RatesVapor Distribution Aids De-Entrainment17. Retrofitting Shell-and-Tube Heat Exchangers for Greater Efficiency 179Running Slops Without FoulingFloating Suction in Charge TanksExchanger Online SpallingEffect of Feed InterruptionsTube Velocity and Surface RoughnessShell-Side Seal StripsCooling High-Viscosity FluidsExpanding Water Cooler CapacityHydrocarbon Losses to Cooling Towers18. Reducing Sulfur and Hydrocarbon Emissions 189Sulfur Plant Waste Heat Boiler ModificationsHydrocarbon Leaks in Seawater Cooling SystemsIncinerator Back-Fire in Sulfur Plant MainReaction FurnaceLoss of Draft Due to Air LeaksGlobal Emissions in Perspective19. Hydrocarbon Leaks to the Environment 201Measuring Leaks Through ValvesFixing Leaking Valves On-StreamDetecting Leaking Relief ValvesOn-Stream Repair of Leaking Relief ValvesMeasuring Flows in Flare LinesLeaks into Cooling WaterAir Cooler LeaksValve Stem PackingLeaking Pump Mechanical Seal and Improper Use of Seal FlushFixing Weld Leaks On-Stream20. Composition-Induced Flooding in Packed Towers: FCU Fractionator Expansion 209Fluid Cracking Unit Fractionator ExpansionFlooding of Slurry Oil P/A SectionsFCU Fractionator Vapor Line QuenchMultipump Piping Stress AnalysisPerception vs. Reality in Process Design21. Maintenance for Longer Run Lengths 219Sulfuric Acid RegenerationImportance of Reactor InsulationOn-Stream Piping RepairsPreserving Pump Mechanical SealsConcept of Avoiding Unit Shutdowns22. Instrument Malfunctions 229Control Valve Loss Due to Instrument Air Pressure SignalStuck Flow Control Valve StemMislocated Liquid-Level TapReducing Load to Vacuum System by Correcting False Level Indication23. Summary Checklist for Reuse of Process Equipment 237Fired HeatersHeat ExchangersFin-Fan Air CoolersDistillation Tower TraysVapor–Liquid SeparatorsCentrifugal PumpsFixed-Bed ReactorsElectric MotorsGas and Steam TurbinesReciprocating and Centrifugal CompressorsAir BlowersWater–Hydrocarbon SeparatorsOvercoming Utility System Limits24. Water–Hydrocarbon Separation: Corrosive Effects of Water 245Water–Oil SeparatorsCorrosive Elements from Cracking PlantsWater Traps in StrippersCurrent CO2 LevelsEnvironmental OverviewAppendix: Solar Power Potential 257Index 259