聚乙烯工艺描述英文模板

年4月19日聚乙烯工艺描述英文模板资料内容仅供您学习参考，如有不当或者侵权，请联系改正或者删除。UNIPOLPEProcessDescriptionUNIPOLPE工艺描述

TableofContentsPROCESSDESCRIPTION1.1 ContractPlantComposition 1.1.1 PEProcessUnit 1.1.2 SupportingFacilities 1.1.3 AuxiliaryFacilities1.2 ProcessIntroduction 1.2.1 DescriptionofPEProcessUnit 1.2.2 DescriptionofSupportingFacilities 1.2.3 DescriptionofAuxiliaryFacilities目录

工艺描述

1.1装置组成1.1.1PE工艺单元1.1.2配套设施1.1.3辅助设施1.2工艺介绍1.2.1PE工艺单元描述1.2.2配套设施描述1.2.3辅助设施描述1.1 ContractPlantCompositionTheContractPlantproduces300,000TPYofpelletedLinearLow,Medium,andHighDensityPolyethylenefromethylene,whichmayinvolvetheadditionofacomonomer(butene-1orhexene-1)forsomeProducts.TheContractPlantBatteryLimitsisrepresentedinthediagramprovidedinAttachment11ofthisAppendix.TheContractPlantconsistsofthefollowingsystems.合同装置组成本合同装置是用乙烯为单体,可能会引入丁烯-1或己烯-1为共聚单体来生产高、低、中密度聚乙烯树脂的装置,产能为30万吨/年。合同装置界区范围见本附件的附录1-1。本合同装置由下列系统组成:1.1.1 PEProcessUnitThePEProcessUnitutilizesUnivationTechnologies’UNIPOL™PEProcess,alowpressuregasphasepolymerizationprocess,andincludesthefollowingprocesssystems: RawMaterialSupplyandPurification EthylenePurification Reaction(includescatalysthandlingandfeeding) ResinDegassing VentRecovery SeedBedSystem ResinAdditiveHandling Pelleting1.1.1PE工艺单元PE工艺单元采用Univation技术公司的UNIPOL聚乙烯技术,这是一种低压气相聚合工艺,包括下列工艺系统:--原料供给和精制--乙烯精制--反应(包括催化剂处理和进料)--树脂脱气--排放气回收--种子床系统--树脂添加剂处理--造粒1.1.2 SupportingFacilities

TheSupportingFacilitiesforthePEProcessUnitincludethefollowingprocesssystems: ResinHandlingSystem1.1.2配套设施PE工艺单元的配套设施包括下列系统:--树脂处理系统1.1.3 AuxiliaryFacilities

TheAuxiliaryFacilitiesforthePEProcessUnitincludethefollowingprocesssystems: SteamandCondensateRecoverySystem FlareSystems WasteWaterCollectionandPretreatmentSystem UtilityDistributionSystem1.1.3辅助设施PE工艺单元的工艺辅助设施包括下列系统:--蒸汽和冷凝水回收系统--火炬系统--废水收集和预处理系统--公用工程配送系统1.2 ProcessIntroduction

ThedesignofthePEProcessUnitwillincorporatethelatestUNIPOLPEProcessKnow-how.

1.2工艺介绍山西焦化聚乙烯装置的设计将采用最新的UNIPOLPE工艺技术。

1.2.1 DescriptionofthePEProcessUnitThePEProcessUnitcomprisesanumberofprocesssystems,whicharedescribedindetailinthefollowingsections: RawMaterialSupplyandPurification(Part1) EthylenePurification(Part2) Reaction(Part4) ResinDegassing(Part5A) VentRecovery(Part5B) SeedBedSystem(Part5E) ResinAdditiveHandling(Part6) Pelleting(Part7)ProcessFlowDiagrams(PFDs)thatrepresenttheseprocesssystemsareprovidedinAttachment12ofthisappendix.AlloftheequipmentdescribedinthefollowingprocessdescriptionisincludedinthepreliminaryequipmentlistprovidedinAppendixPE工艺单元描述PE工艺单元由一系列工艺系统组成,下面对这些系统进行详细描述:原料的供应和精制(第1部分)乙烯的精制(第2部分)反应(第4部分)树脂脱气(第5A部分)排放气回收(第5B部分)种子床系统(第5E部分)树脂添加剂处理(第6部分)造粒(第7部分)工艺流程图(PFD)附于本附件的附录1-2。下面工艺描述中涉及的所有设备见附件5中的初步工艺设备清单。

RawMaterialSupplyandPurification(Part1)NitrogenandhydrogenaredeliveredtotheContractPlantBatteryLimitsbypipeline.Comonomers,butene1andhexene1,andInducedCondensingAgent(ICA),isopentane,aresuppliedtotheContractPlantbypipeline.IthasbeenassumedthatsufficientstoragecapacityisavailablefromtheOutsideBatteryLimits(OSBL)forbutene1,hexene1,andICA.CocatalystalkylisreceivedinshippingcontainersforusedirectlyinthePEProcessUnit.ComonomerPurificationAcommonpurificationsystemisprovidedforthetwocomonomers-butene1andhexene1.LiquidcomonomerfromtheBatteryLimitsisfeddirectlyintotheComonomerDegassingColumn(C1008).Thecolumn,whichismountedontheComonomerSurgeTank(C1007),isequippedwithwatercooledComonomerCondenser(E1009)andsteamheatedComonomerReboiler(E1010).Asmallstreamofoverheadgas,containingstrippedlightgascontaminantsventstotheflare.ThebottomproductfromtheComonomerSurgeTankpassesthroughComonomerCooler(E1011).Thecooler’sprimarypurposeistoprovideadequateNPSHfortheComonomerChargePump(G1002orG1003,aninstalledspare).TheComonomerChargePumpbooststhecomonomerpressuretoapproximately2,861kPag(415psig)forflowintotheReactor.FromtheComonomerChargePump,comonomerflowsthroughtheComonomerDryer(C1004orC1005)toremovewaterandotherpolarimpuritiesfromthecomonomerstreambyphysicaladsorption.Themolecularsievebedsrequireperiodicregenerationwithhotnitrogen.ThespareComonomerDryerisusedwhiletheotherisbeingregenerated,thusallowinguninterruptedcomonomerflow.NitrogenPurificationNitrogenfromtheBatteryLimitspassesthroughtheNitrogenPreheater(E1108)beforeenteringtheNitrogenDeoxoVessel(C1109orC1111).TheNitrogenDeoxoVesselcontainsafixedbedoffreecoppercatalystwhichremovesoxygenfromthenitrogenstreambyoxidationofcoppertocopperoxides.Thecatalystbedrequiresperiodicregenerationwithastreamofhydrogendilutedinhotnitrogen.NitrogenleavingtheNitrogenDeoxoVesselisfedtotheNitrogenDryer(C1112).TheNitrogenDryercontainsmolecularsieveswhichremovewaterandotherpolarimpuritiesfromthenitrogenstreambyphysicaladsorption.Themolecularsievebedrequiresperiodicregenerationwithhotnitrogen.ThespareNitrogenDryerisusedwhiletheotherisbeingregenerated,thusallowinguninterruptednitrogenflow.HighpressurepurifiednitrogenisutilizedintheReactionSystem,whilelowpressurepurifiednitrogenissuppliedtovariousplacesthroughoutthePEProcessUnit.PurifiednitrogentobecompressedforuseintheReactionSystemistakenfromtheoutletoftheNitrogenDryer.ThepressureisboostedbyNitrogenCompressorPackage(K1102)toapressureofabout3,309kPag(480psig).ThehighpressurepurifiednitrogenthenpassesthroughPurifiedNitrogenFilter(Y1114)andflowsontotheReactionSystem.HydrogenPurificationHydrogensupplyfromtheBatteryLimitsispreheatedintheMethanatorHeater(E1204)beforeenteringtheMethanator(C1205).TheMethanatorcontainsafixedbedofcatalystwhichconvertscarbonmonoxideandcarbondioxideinthepresenceofhydrogentoformmethaneandwater.HydrogenleavingtheMethanatoriscooledintheMethanatorAftercooler(E1206)toapproximately40degCandisfedtotheHydrogenDryer(C1207).TheHydrogenDryercontainsmolecularsieveswhichremovewaterfromthehydrogenstreambyphysicaladsorption.Themolecularsievebedrequiresperiodicregenerationwithhotnitrogen.TheHydrogenDryerisbypassedwhilebeingregenerated,thusallowinguninterruptedhydrogenflow.HydrogenfromtheHydrogenDryerisfedtotheReactionSystemortothedeoxovesselswithinthePurificationSystem.ICAPurificationTheUNIPOLPEProcessusesisopentaneasanInducedCondensingAgent(ICA)withintheReactionSystemtoenhanceheatremoval.IsopentanefromtheBatteryLimitsisfeddirectlytotheICADegassingColumn(C1421).Thecolumn,whichismountedontheICASurgeTank(C1406),isequippedwithwatercooledICACondenser(E1422)andsteamheatedICAReboiler(E1415).Asmallstreamofoverheadgas,containingstrippedlightgascontaminantsisventedtoflare.ThebottomproductfromtheICASurgeTankpassesthroughtheICACooler(E1423).TheprimarypurposeofthecooleristoprovideadequateNPSHfortheICAChargePump(G1412orG1413,aninstalledspare).TheICAChargePumpboostsICApressuretoapproximately3,137kPag(455psig)forflowintotheReactor.FromtheICAChargePump,theICAflowsthroughtheICADryer(C1419orC1420)toremovewaterandotherpolarimpuritiesfromtheICAstreambyphysicaladsorption.Themolecularsievebedsrequireperiodicregenerationwithhotnitrogen.ThespareICADryerisusedwhiletheotherisbeingregenerated,thusallowingICAflowtocontinuethroughtheICAPurificationSystem.AlkylAdditiveT2,analkyl,isusedinZiegler-Nattacatalyzedpolymerizationandisconsideredtobeahazardousmaterialinsomelocationsbecauseofitsreactivenature.PurifiednitrogenisusedtopressurethealkylfromtheshippingcontainertotheT2FeedPot(C1505)andthentotheT2ChargePump(G1503orG1504,aninstalledspare).Thesepumpspressurethealkyltoapproximately3,137kPag(455psig)forfeedtotheReactionSystem.AllventsfromtheAdditiveT2SystemareroutedtotheSealPot(C1502)andcombinedwithmineraloiltoproducealessreactivesolution.Periodically,theSealPotcontentsaredrainedtoadisposaltankfordisposalbyanoffsitedisposalcontractor.MineraloilispumpedfromsupplydrumsbyMineralOilDrumPump(G1514)totheSealPotfordilutionofalkyl.Alternately,theMineralOilDrumPumpmaybeusedtotransfermineraloilfromthesupplydrumstotheMineralOilBlowTank(C1512).MineraloilfromtheMineralOilBlowTankisusedforflushingtheAdditiveT2Systemformaintenance.原料的供应及精制(第1部分)

氮气和氢气由管道输送至装置界区内。

共聚单体(丁烯-1、己烯-1)及诱导冷凝剂(ICA)(异戊烷)由界区内的配套设施提供。假定装置界区外有足够的丁烯、己烯及诱导冷凝剂(ICA)储存。

助催化剂烷基铝用钢瓶直接运至PE工艺单元。共聚单体的精制两种共聚单体——丁烯-1和己烯-1共用一个精制系统。来自界区的液相共聚单体直接送入共聚单体脱气塔(C-1008)。脱气塔位于共聚单体缓冲罐(C-1007)之上,塔顶有一个水冷的共聚单体冷凝器(E-1009)使共聚单体冷凝,塔底有一个蒸汽加热的共聚单体再沸器(E-1010)使共聚单体汽化。塔顶脱除的少量的轻组分塔顶气被排放到火炬。共聚单体缓冲罐的底部产品由共聚单体冷却器(E-1011)冷却。冷却器的主要目的是为共聚单体进料泵(G-1002或G-1003,其中一个是在线备用泵)提供足够的有效气蚀余量。共聚单体进料泵使共聚单体增压至大约2861kPag(415psig)后进入反应器。来自共聚单体进料泵的共聚单体进入共聚单体干燥器(C-1004或C-1005),经过物理吸收作用除去共聚单体物流中的水分和其它极性杂质。分子筛床层需要用热氮气定期再生。当一个共聚单体干燥器进行再生时,就启用备用的共聚单体干燥器,这样可使共聚单体不间断地流入反应系统。

氮气的精制从界区来的氮气在进入氮气脱氧罐(C-1109或C-1111)之前在氮气预热器(E-1108)中进行预热。氮气脱氧罐含有一个游离铜催化剂的固定床,经过将游离铜氧化成氧化铜而除去氮气中的氧气。催化剂床需要用含有少量氢气的热氮气进行定期再生。离开氮气脱氧罐的氮气进入氮气干燥器(C-1112)。氮气干燥器内设有分子筛,经过物理吸收作用除去氮气中的水分和其它极性杂质。分子筛需要用热氮气定期再生。一台氮气干燥器再生时,另外一台备用干燥器启动运行,以保证氮气持续地流入反应系统。高压精制的氮气用于反应系统,而低压精制的氮气供给整个PE工艺单元各个不同地方使用。氮气干燥器的出口的精制氮气经过压缩后即可供反应系统使用。精制氮气由氮气压缩机(K-1102)增压至大约3309kPag(480psig)的压力后经由精制氮气过滤器(Y-1114)进入反应系统。氢气的精制由界区来的氢气进入甲醇转化器加热器(E-1204)预热后,进入甲烷转化器(C-1205)。甲烷转化器内有固定的催化剂床,在氢气的作用下,将一氧化碳和二氧化碳转化成甲烷和水。从甲烷转化器出来的氢气在甲烷后冷器(E-1206)中冷却到大约40摄氏度后,进入到氢气干燥器(C-1207)。氢气干燥器中的分子筛能够经过物理吸附的作用,将氢气中的水脱除。分子筛需要使用热氮进行周期性的再生。再生时,氢气干燥器的旁路会打开,以保证氢气连续地流入反应系统。

从氢气干燥器出来的氢气送入反应系统或进入精制系统内的脱氧罐。ICA的精制

UNIPOLPE工艺采用异戊烷作为诱导冷凝剂以增强反应系统内的除热速率。来自界区的异戊烷直接进入ICA脱气塔(C-1421)。此塔安装在ICA缓冲罐(C-1406)之上,塔顶配有水冷的ICA冷凝器(E-1422)使异戊烷冷凝,塔底有一个蒸汽加热的ICA再沸器(E-1415)使异戊烷汽化。含有脱除的轻组分的一小股塔顶气被排放到火炬。从ICA缓冲罐底部出来后,进入ICA冷却器(E-1423)。冷却器的主要目的是为ICA进料泵(G-1412或G-1413,其中一个是在线备用泵)提供足够的有效气蚀余量。ICA进料泵使ICA增压至大约3137kPag(455psig)后进入反应器。被送入反应器之前,ICA要经过ICA干燥器(C1419或C-1420)。ICA干燥器利用分子筛经过物理吸附的方式除去其中的水分和其它极性杂质。分子筛床层需要用热氮气定期再生。当一个ICA干燥器进行再生时,就启用备用的ICA干燥器,这样使ICA连续地流入反应系统。EthylenePurification(Part2)EthylenefromtheBatteryLimitspassesthroughtheshelloftheEthyleneInterchanger(E2105)whereitisinterchangedwithethylenefromtheEthyleneCORemovalVessel(C2107).ThewarmethylenethenpassesthroughtheEthylenePreheater(E2106)whereitisheatedto100degCbeforeenteringtheEthyleneDeoxoVessel(C2109)andthentheEthyleneCORemovalVessel.TheEthylenePreheaterisusedtoachievethefinaltemperaturebeforeenteringtheEthyleneDeoxoVesselandforinitialheatingonplantstart-up.TheEthyleneDeoxoVesselcontainsafixedbedoffreecoppercatalystwhichremovesoxygenfromtheethylenestreambyoxidationofthecoppertocopperoxides.Thisbedrequiresperiodicregenerationwithastreamofhydrogendilutedinnitrogen.TheEthyleneCORemovalVesselcontainsafixedbedofacopperbasedadsorbent.Thisbedrequiresperiodicregenerationwithastreamofoxygendilutedinnitrogen.Ethylene,afterleavingtheEthyleneCORemovalVessel,iscooledtoapproximately40degCintheEthyleneInterchangerbeforepassingthroughtheEthyleneDryer(C2112orC2113).TheEthyleneDryerscontainmolecularsievesandactivatedalumina,whichremovecarbondioxide,water,andotherpolarimpuritiesfromtheethylenestreambyphysicaladsorption.TheEthyleneDryerrequiresperiodicregenerationwithhotnitrogen.ThespareEthyleneDryerisusedwhiletheotherisbeingregenerated,thusallowinguninterruptedethyleneflowtotheReactionSystem.RegenerationofPart1andPart2PurificationBedsThevariouspurificationbedswithinPart1andPart2areregeneratedperiodically.Theregenerationcyclesarecontrolledwithtimersandlogicinterlocks.Valvingisperformedmanuallyinthefield.NitrogenfromthesupplyheaderenterstheRegenerationNitrogenHeater(E2114)onflowcontrol.ThenitrogenisheatedbythiselectricresistanceheatertotherequiredtemperatureforregenerationoftheregenerablepurificationbedsinPart1andPart2.Thehotnitrogenflowstotheselectedbedthroughdistributionpiping.Thecoolingandpreloadstepsoftheregenerationcycleforalldryersuselowpressureunpurifiednitrogen.Theventstreamfromthepurificationbedbeingregeneratediseitherflaredorventedtoatmosphere.乙烯的精制(第2部分)来自界区的乙烯经过乙烯级间换热器(E-2105)的外壳,与来自乙烯CO脱除罐(C-2107)中的乙烯进行级间换热。升温后的乙烯在进入乙烯预热器(E-2106)加热到100℃后,进入到乙烯脱氧罐(C-2109),随后进入乙烯CO脱除罐。乙烯经过乙烯预热器将乙烯加温到最终温度后,进入到乙烯脱氧器,开车的时候也会使用乙烯预热器来进行预热。

乙烯脱氧罐内有一个游离铜催化剂的固定床,经过将游离铜氧化成氧化铜而除去乙烯中的氧气。这种床需要用氢气稀释的氮气进行定期再生。乙烯CO脱除罐内有一个氧化铜固定床。这种床层要用氧气稀释的氮气进行定期再生。从乙烯脱氧罐和乙烯CO脱除罐出来的乙烯,经乙烯级间换热器冷却到40℃后,进入乙烯干燥器(C-2112或C-2113),乙烯干燥器中含有分子筛和活性氧化铝,这两种物质经过物理吸附作用除去乙烯物流中的CO2、水分和其它极性杂质。乙烯干燥器需要用热氮气定期再生。当一台乙烯干燥器再生时,另一台备用设备启用,这样可使乙烯持续地流入到反应系统。第一部分和第二部分精制床的再生第一部分和第二部分精制床需要定期再生。再生的周期由计时器和逻辑内部连锁控制。阀是现场手动操控的。来自氮气总管的氮气在流量控制下进入再生氮气加热器(E-2114)。氮气被电阻加热器加热到第1部分和第2部分中的可再生精制床再生所需的温度。热氮气经过输送管道进入需再生床层。所有的干燥器再生时的冷却和预负荷使用低压未精制氮气。精制床再生时产生的排放气或者送入火炬或者排入大气。

Reaction(Part4)Resinisproducedbypolymerizationofreactantsinafluidizedbedreactoratanominalpressureof2,413kPag(350psig)andnominaltemperaturesof80to100degC.AnexternallycooledcycleofreactantgasfluidizestheReactorbedandremovestheexothermicheatofreaction.Catalystandpurifiedreactants(ethylene,butene1orhexene1,andhydrogen)arefedcontinuouslytotheReactor.ResinflowsintermittentlyfromtheReactorthroughapairofProductDischargeSystemswhichoperateinasequentiallyalternatingmode.Duringtheproductdischargecycle,someoftheentrainedreactiongasistransferredtotheotherdischargesystem.ThistemporarilystoredreactiongasisindirectlyreturnedtotheReactorduringthenextdischargecycle,therebyminimizingthereactorgasreleasedfromtheReactionSystem.TheresinistransportedtotheProductPurgeBin(C5009inPart5A)withtheconveyinggasbeingsentontotheVentRecoverySystem(Part5B).CertainmodifiersareaddedtotheReactorforvariousreasons.Analkyl(AdditiveT2)isfedtotheReactionSystemcontinuouslyduringZiegler-Nattacatalyzedpolymerization.AnothermodifierisinjectedintotheReactorduringupsetconditionstoquickly"kill"thepolymerizationreaction.Thismodifier,areversiblecatalystpoison,canbeinjectedthroughmanualorautomaticactuationoftheKillSystemcontrollogic.Resinpropertiesarecontrolledprimarilybythetypeofcatalystusedandbythecyclegascomposition.Thetypeofcatalystdeterminesthemolecularweightdistribution.Thequantityofcomonomerinthecyclegasdeterminestheresindensityandthequantityofhydrogendeterminesthemeltindex.TheProcessComputingSystemcanmaintainclosed-loopcontrolofthesepropertiesbymakinginstantaneouspredictionsoftheresinpropertiesintheReactor,andadjustingvariablesasnecessary.反应(部分4)

反应物质一般在压力为2413kPag(350psig)、温度约80到100℃的流化床反应器内发生聚合生产出树脂。经过外部的反应气冷却循环使反应器床流化,同时除去反应热。催化剂和精制的反应物(乙烯、丁烯-1或己烯-1和氢气)连续被送入反应器。树脂从反应器间歇地流入到2条交替作业的产品卸料系统。在产品卸料过程中,一些夹带的反应气被送到另一个卸料系统。这些在卸料系统临时储存的反应气在下一个卸料周期间接地返回反应器,这样能够减少反应系统中反应气的损失。树脂被送往产品脱气仓(第5A部分中的C-5009),同时输送气进入排放气回收系

统(第5B部分)。

出于各种原因会向反应器加入某些改性剂。当生产齐格勒—那塔树脂时,向反应器内连续地注入烷基铝。在反应出现故障情况时,向反应器内注入另一种改性剂以快速地”终止”聚合反应。这种改性剂是一种可逆的催化剂毒物,它能经过手动或终止系统逻辑控制的自动启动而注入到反应器。树脂产品的性质主要由所采用的催化剂的类型和循环气的组成所控制。催化剂的类型决定了分子量的分布。循环气中共聚单体的量决定了树脂的密度,循环气中氢气的量决定了树脂的熔融指数。工艺计算机系统经过对反应器中的树脂性质进行瞬时的预测,同时按需要调整变量,来达到对这些性质的闭路控制。

ReactionSystemTheReactionSystemconsistsofaReactor(C4001),aCycleGasCooler(E4002AorE4002B,aninstalledunconnectedspare),andaCycleGasCompressor(K4003).Thegaseousreactants(amixtureofethylene,butene1orhexene1,andhydrogen)andinertsarecontinuouslycycledbytheCycleGasCompressorthroughafluidizedbedofresininwhichcatalystisinjected.TheheatofpolymerizationistransferredtothecyclegasandremovedintheexternalCycleGasCooler.Ifneeded,asmallamountofcyclegasisventedtotheflareviatheProductPurgeBintomaintaintheproperreactantconcentrationsintheReactionSystem.TheReactorisaskirtsupportedcylindricalvesselwithatopexpandedsectionfordisengagementofparticlesfromthecyclegasstream.Aperforateddistributorplatesupportsthebedofgranularresinanddistributesgasflowintothebottomofthebed.ManwaysareprovidedatmultiplelevelstopermitaccesstotheReactorformaintenance.TheCycleGasCompressorisasinglestage,openwheel,constantspeed,centrifugalcompressor.Thecyclegascirculationflowrateiscontrolledbyinletguidevanesatthesuctionofthecompressor.TheCycleGasCompressorisdesignedtooperateutilizingadrygassealsystem.TheCycleGasCoolerisasingle-passshellandtubeheatexchanger.Cyclegasflowsthroughthetubesandtemperedwaterflowscounter-currentthroughtheshell.TheTemperedWaterSystemisatemperaturecontrolledrecirculationsystem.Acentrifugalpump,CycleWaterPump(G4004orG4005,aninstalledspare),circulatesthetemperedwaterthroughoutthecoolingsystem.VaryingtheamountoftemperedwaterbypassedaroundtheTemperedWaterCooler(E4007)controlsthetemperatureofthetemperedwaterenteringtheCycleGasCooler.AdjustingthetemperaturesetpointoftheTemperedWaterSystemcontrolstheReactortemperature.SincetheTemperedWaterSystemwillseearangeoftemperatures,anExpansionTank(D4010)isprovidedtoallowforthermalexpansionofthetemperedwater.TheTemperedWaterSystemisalsousedtoheattheReactionSystemwheninitiallystartingup.ThetemperedwateristemporarilyusedasaheatingmediumwhensteamisintroducedtotheTemperedWaterSystemviaasparger.Reactorpressureiscontrolledbyvaryingtheethylenefeedrate.Theratiosofcomonomerandhydrogentoethylenearemeasuredbyanon-linecyclegasanalyzer,andtheflowsareautomaticallycontrolledasnecessarytomaintaintherequiredcyclegascomposition.Beforestartup,granularpolyethyleneresinmustbechargedintotheReactortoprovideareactionbed.TheresinwillbechargedtotheReactorthroughanozzlenearthetopofthestraightsideoftheReactor.TheconveyinglinetotheReactorprovidesfortransferofresinfromtheSeedBedResinStorageBin(Part5E).Thepolymerizationreactioncanbestoppedorsloweddownbytheintroductionofamodifier(ModifierC)intotheReactionSystem.TheKillSystemconsistsofcylinderbottlescontainingthemodifierandasystemofdistributionpipingandairoperatedvalvesdesignedtoinjectthemodifierintothecyclegaspipingwhentheKillSystemlogicisactuatedinoneofthefollowingscenarios: AkillisinitiatedmanuallyorautomaticallybyhighReactorbedtemperature.ThemodifieriscirculatedandmixedthroughtheReactionSystembythecyclegasflow,therebydeactivatingthecatalystinthebed. AkillisautomaticallyinitiatedbyalossofcyclegasflowforreasonsotherthanaCycleGasCompressorshutdownformechanicalprotection.ThemodifierisinjectedintothecyclegaspipingwhilethecyclegasisventedthroughtheCycleGasTurbine(KT4003)totheflare.TheCycleGasTurbinedrivestheCycleGasCompressoratareducedspeed,circulatingandmixingthemodifierthroughtheReactionSystem,therebydeactivatingthecatalystinthebed.反应系统反应系统由反应器(C-4001)、循环气冷却器(E-4002A或E-4002B,一个备用,非连接)和循环气压缩机(K-4003)组成。气态反应物(乙烯、丁烯-1或己烯-1,和氢气的混和物)和惰性组分在循环气压缩机的压送下连续地循环经过注入有催化剂的树脂流化床。聚合反应的反应热由循环气带出并被外部的循环气冷却器除去。如果需要的话,少量的循环气可经过产品脱气仓排放到火炬,以此来保持反应系统内适当的反应物浓度。反应器是一个圆柱状带裙座设备,顶部带有一个膨胀的部分以分离循环气中的固体颗粒。一个多孔的分布板支撑树脂粉料床,气体经分布板分布后流入床层底部。有不同标高的人孔,以备检修人员能进入反应器。循环气压缩机是一个单级、开式叶轮、恒速、离心式压缩机。压缩机入口的导向叶片控制循环气的循环速率。循环气压缩机的设计是在干气体密封系统的条件下运行。循环气冷却器是一个单程的管壳式换热器。循环气走管程,同时调温水逆流走壳程。调温水系统是一个控制温度的再循环系统。经过离心式调温水泵(G-4004,G-4005,一个备用)使得调温水在冷却系统中循环。改变调温水冷却器(E-4007)旁路调温水的速率控制进入循环气冷却器的调温水的温度。调节调温水系统的温度设定点来控制反应器温度。因为调温水系统温度不是一个固定值,而是一个温度范围,设置一个膨胀罐(D-4010)使调温水适应不同的热胀。调温水系统也用于在装置初始开车时加热反应系统。当蒸汽经过喷雾器送入到调温水系统时,调温水可作为临时热媒。反应器压力经过改变乙烯进料速率来控制。共聚单体和氢气与乙烯的比例经过循环气在线分析仪来测量,流量根据需要的循环气体组成自动控制。装置开车前,必须向反应器装入聚乙烯树脂粉料来作为种子床。树脂经过反应器垂直段上部的管嘴加入反应器。树脂经过专用的风送线从种子床树脂储仓(第5E部分)输送到反应器。可经过注入改性剂C来终止聚合反应或使聚合反应减慢。终止系统包括终止剂钢瓶、输送管道以及用来将终止剂注入循环气管道的气动阀。当以下几种工况发生时,终止系统逻辑将会启动:终止系统可手动启动也可在反应器床温过高时自动启动。改性剂经过循环气物流在反应系统内循环和混合,这样就可将反应器床层的催化剂脱活。终止系统除了在循环气压缩机机械故障停车时自动启动外还可在循环气流量降低时自动启动。当循环气经过循环气透平(KT-4003)排至火炬时,改性剂被注入循环气管道。循环气透平以逐渐越小的速率驱动循环气压缩机,改性剂在反应系统内循环和混合,这样就可将反应器床层的催化剂脱活。

CatalystHandlingandFeeding–SlurryCatalystZiegler-Nattacatalyzedresinsareproducedusingaslurrycatalyst.SlurryCatalystispreparedbymixingcatalystprecursorwithreducingagents.Catalystprecursorslurryisreceivedinreusableshippingcylinders.Priortounloading,theprecursorshippingcylindersarerolledtoensurethesolidsarecompletelysuspendedinthemineraloil.ACylinderRoller(S4060)isprovidedforthispurpose.Therolledcylindersareimmediatelytransportedfromthestorageareatotheslurryprecursorsupplyarea.TheprecursorslurryispressuredoutoftheshippingcylinderwithnitrogentotheSlurryFeedTank(C4050).TheprecursorslurryiscontinuouslystirredbySlurryFeedTankAgitator(Y4052)intheSlurryFeedTanktoensurethatsolidsarewelldispersedandmaintainedinsuspension.ThereductionoftheprecursorslurryrequirestheadditionofAdditiveT3andAdditiveDC.Theseadditivesarereceivedinshippingcontainersdilutedinmineraloil.AdditivesT3andDCarepressuredoutofshippingcontainerswithnitrogentotheirrespectiveFeedPots(C4067andC4065).Thefeedpotsprovideasmallsurgevolumewhichallowscontinuousoperationduringchangeoverofshippingcontainers.TheprecursorslurryfromtheSlurryFeedTankispumpedbythevariablespeedcontrolledSlurryFeedPump(G4051orG4055aninstalledspare)eitherinrecirculationmodebacktotheSlurryFeedTankorinjectionmodeintotheReactor.Theprecursorslurryflowismeasuredbyamassflowmeter.TheDCFeedPump(G4053),T3FeedPump(G4054),andcommoninstalledspareT3/DCFeedPump(G4058),areprovidedforthecontinuouspumpingofAdditiveDCandAdditiveT3fromtherespectiveFeedPottotheprecursorlinedownstreamoftheSlurryFeedPump.Theadditiveflowsaremeasuredbymassflowmeterandareflowcontrolledbasedontheprecursorslurrymassflow.AdditiveDCandAdditiveT3areinjectedintotheprecursorstreamatseparateinjectionpoints.AdditiveT3injectsintotheprecursorstreamimmediatelydownstreamoftheSlurryFeedPump.TheT3/precursormixtureflowstotheT3ResidenceTimePotandAgitator(C4056)whereitisgiventimetoreact.AdditiveDCinjectsintotheT3/precursorstreamexitingtheT3ResidenceTimePot.ReactioncontinuesintheDCResidenceTimePotandAgitator(C4057).ThereducedcatalystissenttotheReactor.Acarrieragent,highpressurepurifiednitrogen,isprovidedtoassistinjectionoftheslurryintotheReactor.催化剂处理和加料添加淤浆催化剂生产齐格勒－那塔聚乙烯树脂时,用的是淤浆催化剂。淤浆催化剂由原质催化剂和还原剂混和制得。原质催化剂淤浆存储在可重复使用的钢瓶中。在卸料前,要滚动原质催化剂输送钢瓶以确保固体完全悬浮在矿物油中。设置钢瓶滚瓶机(S-4060)来实现此目的。滚动后的钢瓶快速从储存区传送至催化剂供应区。用氮气将原质浆液从钢瓶中压至淤浆进料罐(C-4050)。淤浆进料罐搅拌器(Y-4052)连续搅拌以保证固体很好地分散,并保持在悬浮状态。原质浆液需要加入添加剂T3和添加剂DC还原。这些添加剂稀释于矿物油中存储在钢瓶中。氮气将添加剂T3和添加剂DC从钢瓶中压出送入各自的进料罐(C-4067和C-4065)。进料罐设计有一个小的缓冲空间,以实现在更换钢瓶时系统仍能连续操作。淤浆进料罐中的原质浆液由可变速控制的淤浆进料泵(G-4051或G-4055,一个在线备用)或者以再循环模式重新返回淤浆进料罐或者以注入模式送入反应器。原质浆液流率由质量流量计测量。DC进料泵(G-4053)、T3进料泵(G-4054)和它们共用的备用泵T3、DC进料泵(G-4058)用于将添加剂T3和添加剂DC连续不断的从它们各自的进料罐送入淤浆进料泵下游的原质浆液线。烷基铝的流量由质量流量计测量,其流量根据原质浆液的质量流率来控制。添加剂T3和添加剂DC从不同的注入点注入原质浆液线。添加剂T3在紧靠淤浆进料泵下游处注入原质浆液线。T3和原浆的混和物流入T3停留罐和搅拌器(C-4056),并在那里进行反应。添加剂DC注入从T3停留罐出来的T3和原浆的混和物流。反应在DC停留罐和搅拌器(C-4057)中继续进行。还原后的催化剂送入反应器。作为输送气的高压精制氮气可协助将浆液注入到反应器。CatalystHandlingandFeeding–MineralOilFlushSystemAmineraloilflushsystemisprovidedtofacilitateperiodicflushingofalllinesandequipmentwithintheSlurryCatalystSystem.MineraloilusedforflushingispumpedfromdrumswiththeMineralOilDrumPump(G4068),intotheMineralOilBlowTank(C4069),wherenitrogenisusedtopressurethemineraloilthroughoutthesystem.PrecursorlinesandequipmentwillbeflusheddirectlytoaportableSlurryDisposalTank.AdditiveT3andAdditiveDClinesandequipmentwillbeflushedtotheSealPot(C4045),andthendrainedintotheportableSealPotDisposalTank.ADisposalTankScale(S4064)isprovidedtomonitortheleveloftheSealPotDisposalTankandSlurryDisposalTankcontents.Periodically,thecontentsoftheSealPotDisposalTankandtheSlurryDisposalTankaresenttoanoffsitedisposalcontractorfordisposal.催化剂处理和加料系统矿物油冲洗系统矿物油冲洗系统用于定期冲洗淤浆催化剂系统内的所有管线及生产设备。用于冲洗的矿物油由矿物油卸料泵(G-4068)从矿物油桶送入矿物油排放罐(C-4069),使用氮气输送矿物油到整个系统。原质浆液的管线和设备经过冲洗后,废矿物油会直接排到一个便携式的淤浆处理罐内。添加剂T3,添加剂DC,的管线及设备经过冲洗后,废矿物油进入密封罐(C-4045),之后被排入便携式的密封罐处理罐。处理钢瓶秤(S-4064)用于监测密封罐处理钢瓶及淤浆处理罐的液位和物质。密封罐处理罐中的物质和淤浆处理罐中的物质会定期地送到厂外废物处理承包商那进行处理。CatalystHandlingandFeeding–DryCatalystFullyformulateddrycatalystisfedtotheReactorbytwo(2)ModularCatalystFeeders(V4036andV4037)whichareofproprietaryUnivationdesign.TheModularCatalystFeedersaresufficienttomeetdesignca