6VENTGAS-592

VENTGASRECOVERYSYSTEMDESCRIPTIONANDSTARTUPNOTE:ThisisforTrainingonly,andisnotintendedtobeusedasastepbystepprocedure.PO/MTBEVENTGASSYSTEMSTARTUPVENTGASRECOVERYSYSTEMDESCRIPTIONANDSTARTUPPurposeThisdocumentisonlyaguidelineanddoesnotreplaceanyoftheStartUpProcedures.FollowallStartUpProceduresandthisguidelinewillaidinstartupoftheVentGasRecoverySystem.ThepurposeoftheVentGasRecoverySystemistoprovideameansofrecoveringhydrocarbonvaporsfromtheplantoffgasandusetheventgasforfueltomakesteaminsteadofventingtheventgastotheflare.Themaximumflowrateforthelowpressureventgasheaderis8188kg/hr.BasicFlowsTheVentGasRecoverySystemhasmainlateralsthatflowfromeachblocktotheVentGasCompressorKnockOutDrum.ThisdrumallowstheremovalofanyliquidhydrocarbonorcondensatefromthevaporbeforethevaporreachesthesuctionofVentGasCompressors.NOTE:ThisisforTrainingonly,andisnotintendedtobeusedasastepbystepprocedure.PO/MTBEThesuctionsideoftheVentGasCompressorsistheLowPressureVentGasandthedischargesideoftheVentGasCompressorsistheHighPressureVentGas.TheequipmentthatventsintothemainL.P.VentGaslateralsareasfollows:•TBHPConcentrationColumnVacuumPackage•C5StripperRefluxDrum•MethanolStripperRefluxDrum•LightsRectifierCondenser•MTBERecoveryCondenser•MTBERecoveryTrimCondenser•EGMERegeneratorCondenser•EGMERefluxDrum•MTBERecoveryVentCondenserVENTGASSYSTEMSTARTUPNOTE:ThisisforTrainingonly,andisnotintendedtobeusedasastepbystepprocedure.PO/MTBE•MTBERecoveryRefluxDrum•TBAFeedFractionationTrimCondenser•TBAVacuumPackage•WastewaterDegassingDrum•ResidueEvaporatorVacuumPackage•WastewaterStripperRefluxDrum•TBAPurificationColumnRefluxDrum•TBAPurificationColumnCondenser•CatalystRecoveryDrum•ProcessFuelSurgeDrum•MethanolStripperCondenser•MethanolStripperRefluxDrumVENTGASSYSTEMSTARTUPNOTE:ThisisforTrainingonly,andisnotintendedtobeusedasastepbystepprocedure.PO/MTBE•MethanolFeedSurgeDrum•CatalystSolutionBlowdownPot•CatalystSolutionTanks•AnalyzerSheltersandvarioussamplepoints.TheVentGaslateralshaveN7nitrogenpurgesontheendofthelateralsaswellasontheendofthelowpressureventgasheader.ThelowpressureventgasheaderflowsintotheVentGasCompressorKnockOutDrum.TheliquidhydrocarbonandcondensateispumpedtoProcessFuelSurgeDrumviaVentGasK.O.Pump.ThevaporleavingthetopoftheknockoutdrumgoestothesuctionoftheonlineVentGasCompressors.ThecompressedvaporisthenpumpedtoBoilersasfuelgas.PartofthecompressedvaporisusedasrecyclewhichtiesintothelowpressureventgasheaderafterbeingcooledintheVentGasCompressorRecycleCoolertoholdsuctionpressurewhenthereislowpressureontheLowPressureVentGasHeader.VENTGASSYSTEMSTARTUPNOTE:ThisisforTrainingonly,andisnotintendedtobeusedasastepbystepprocedure.PO/MTBEThedischargesideoftheVentGasCompressorsbecomesthehighpressureventgasheaderanddischargestothemixfuelgasdrum.Theequipmentthatventsintothehighpressureventgasheaderareasfollows:•1stIC4RecycleColumn2ndVentCondenser•1stIC4RecycleVentCondensateDrum•PropyleneRecycleColumnOVHDCondenser•PropyleneRecycleColumnRefluxDrum•PropyleneRecoveryColumnVentCondenser•AlcoholRecycleRefluxDrum•MTBEDryingColumnRefluxDrum•MTBEDryingColumnCondenserVENTGASSYSTEMSTARTUPNOTE:ThisisforTrainingonly,andisnotintendedtobeusedasastepbystepprocedure.PO/MTBE•1stIC4RecycleColumnRefluxDrum•1stIC4RecycleColumnCondensers•EpoxidationPropyleneStorageDrum•HPFlareGasRecoverySystemVENTGASRECOVERYSYSTEMINITIALSTARTUPGUIDELINEConditionsThisprocedureisperformedunderthefollowingconditions:•VentGasCompressorshavebeenthroughT&Iand/ormaintenancerepairsandtheyarecomplete•Boilersareinserviceandreadytoreceiveventgas•LPVentGassystemandhighpressureventgassystemarebothair/oxygenfreeandreadytoreturntoservice•Allcontrolvalvesarelinedupwithcontrolvalvesintheclosedposition.VENTGASSYSTEMSTARTUPNOTE:ThisisforTrainingonly,andisnotintendedtobeusedasastepbystepprocedure.PO/MTBE•Allcontrolvalvebypassesareclosed.•Associatedequipmentinstrumentation/analyzershavebeenconnectedandreadyforservice.•Allcontrolvalveshavebeenverifiedforproperoperation.•AllisolationblindshavebeenturnedtotheproperoperatingpositionaspertheVisualInspectionBlindRemovalProcedure.•Allutilityconnectionshavebeenturnedawayfromthetank,vessels,equipmentandlines,blockedinonthevesselandblinded.•VesselsandassociatedequipmenthasbeenpurgedofoxygenaspertheOxygenRemovalofProcessEquipmentprocedure.•PipinghasbeenpressuretestedaspertheTightnessTestingofProcessEquipmentprocedure.VENTGASSYSTEMSTARTUPNOTE:ThisisforTrainingonly,andisnotintendedtobeusedasastepbystepprocedure.PO/MTBE•EnsureallPSVsareproperlylinedupwiththePSVbypassesclosed.•Lineupallsightglassesforproperoperation.•Ensureallheattracingisplacedbackinservice.Guideline•Ensureventgascompressorisreadyforstart-upbasedonvendorinstructions(coolingwater,lubeoil,etc).•Verifysuctionpotislineduptoliquidpressurepumptoremoveanyliquidfromsystem.•VerifycompressorcaseisfreeofliquidbycheckingdraintoDOhub.•Ensuresuctionanddischargevalvesonliquidpressurepumparelinedupintheopenpositionsandthenitrogenisalsolinedup.•Verifytheoutlet(dischargeside)ofthepressurepumpsarelinedupintotheprocessfuelslineattheliquidremoval