聚乙烯工藝描述英文模板

年4月19日聚乙烯工藝描述英文模板資料內(nèi)容僅供您學(xué)習(xí)參考，如有不當(dāng)或者侵權(quán)，請聯(lián)系改正或者刪除。UNIPOLPEProcessDescriptionUNIPOLPE工藝描述

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目錄

工藝描述

1.1裝置組成1.1.1PE工藝單元1.1.2配套設(shè)施1.1.3輔助設(shè)施1.2工藝介紹1.2.1PE工藝單元描述1.2.2配套設(shè)施描述1.2.3輔助設(shè)施描述1.1 ContractPlantCompositionTheContractPlantproduces300,000TPYofpelletedLinearLow,Medium,andHighDensityPolyethylenefromethylene,whichmayinvolvetheadditionofacomonomer(butene-1orhexene-1)forsomeProducts.TheContractPlantBatteryLimitsisrepresentedinthediagramprovidedinAttachment11ofthisAppendix.TheContractPlantconsistsofthefollowingsystems.合同裝置組成本合同裝置是用乙烯為單體,可能會引入丁烯-1或己烯-1為共聚單體來生產(chǎn)高、低、中密度聚乙烯樹脂的裝置,產(chǎn)能為30萬噸/年。合同裝置界區(qū)范圍見本附件的附錄1-1。本合同裝置由下列系統(tǒng)組成:1.1.1 PEProcessUnitThePEProcessUnitutilizesUnivationTechnologies’UNIPOL?PEProcess,alowpressuregasphasepolymerizationprocess,andincludesthefollowingprocesssystems: RawMaterialSupplyandPurification EthylenePurification Reaction(includescatalysthandlingandfeeding) ResinDegassing VentRecovery SeedBedSystem ResinAdditiveHandling Pelleting1.1.1PE工藝單元PE工藝單元采用Univation技術(shù)公司的UNIPOL聚乙烯技術(shù),這是一種低壓氣相聚合工藝,包括下列工藝系統(tǒng):--原料供給和精制--乙烯精制--反應(yīng)(包括催化劑處理和進(jìn)料)--樹脂脫氣--排放氣回收--種子床系統(tǒng)--樹脂添加劑處理--造粒1.1.2 SupportingFacilities

TheSupportingFacilitiesforthePEProcessUnitincludethefollowingprocesssystems: ResinHandlingSystem1.1.2配套設(shè)施PE工藝單元的配套設(shè)施包括下列系統(tǒng):--樹脂處理系統(tǒng)1.1.3 AuxiliaryFacilities

TheAuxiliaryFacilitiesforthePEProcessUnitincludethefollowingprocesssystems: SteamandCondensateRecoverySystem FlareSystems WasteWaterCollectionandPretreatmentSystem UtilityDistributionSystem1.1.3輔助設(shè)施PE工藝單元的工藝輔助設(shè)施包括下列系統(tǒng):--蒸汽和冷凝水回收系統(tǒng)--火炬系統(tǒng)--廢水收集和預(yù)處理系統(tǒng)--公用工程配送系統(tǒng)1.2 ProcessIntroduction

ThedesignofthePEProcessUnitwillincorporatethelatestUNIPOLPEProcessKnow-how.

1.2工藝介紹山西焦化聚乙烯裝置的設(shè)計(jì)將采用最新的UNIPOLPE工藝技術(shù)。

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工藝單元描述PE工藝單元由一系列工藝系統(tǒng)組成,下面對這些系統(tǒng)進(jìn)行詳細(xì)描述:原料的供應(yīng)和精制(第1部分)乙烯的精制(第2部分)反應(yīng)(第4部分)樹脂脫氣(第5A部分)排放氣回收(第5B部分)種子床系統(tǒng)(第5E部分)樹脂添加劑處理(第6部分)造粒(第7部分)工藝流程圖(PFD)附于本附件的附錄1-2。下面工藝描述中涉及的所有設(shè)備見附件5中的初步工藝設(shè)備清單。

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.原料的供應(yīng)及精制(第1部分)

氮?dú)夂蜌錃庥晒艿垒斔椭裂b置界區(qū)內(nèi)。

共聚單體(丁烯-1、己烯-1)及誘導(dǎo)冷凝劑(ICA)(異戊烷)由界區(qū)內(nèi)的配套設(shè)施提供。假定裝置界區(qū)外有足夠的丁烯、己烯及誘導(dǎo)冷凝劑(ICA)儲存。

助催化劑烷基鋁用鋼瓶直接運(yùn)至PE工藝單元。共聚單體的精制兩種共聚單體——丁烯-1和己烯-1共用一個精制系統(tǒng)。來自界區(qū)的液相共聚單體直接送入共聚單體脫氣塔(C-1008)。脫氣塔位于共聚單體緩沖罐(C-1007)之上,塔頂有一個水冷的共聚單體冷凝器(E-1009)使共聚單體冷凝,塔底有一個蒸汽加熱的共聚單體再沸器(E-1010)使共聚單體汽化。塔頂脫除的少量的輕組分塔頂氣被排放到火炬。共聚單體緩沖罐的底部產(chǎn)品由共聚單體冷卻器(E-1011)冷卻。冷卻器的主要目的是為共聚單體進(jìn)料泵(G-1002或G-1003,其中一個是在線備用泵)提供足夠的有效氣蝕余量。共聚單體進(jìn)料泵使共聚單體增壓至大約2861kPag(415psig)后進(jìn)入反應(yīng)器。來自共聚單體進(jìn)料泵的共聚單體進(jìn)入共聚單體干燥器(C-1004或C-1005),經(jīng)過物理吸收作用除去共聚單體物流中的水分和其它極性雜質(zhì)。分子篩床層需要用熱氮?dú)舛ㄆ谠偕．?dāng)一個共聚單體干燥器進(jìn)行再生時(shí),就啟用備用的共聚單體干燥器,這樣可使共聚單體不間斷地流入反應(yīng)系統(tǒng)。

氮?dú)獾木茝慕鐓^(qū)來的氮?dú)庠谶M(jìn)入氮?dú)饷撗豕?C-1109或C-1111)之前在氮?dú)忸A(yù)熱器(E-1108)中進(jìn)行預(yù)熱。氮?dú)饷撗豕藓幸粋€游離銅催化劑的固定床,經(jīng)過將游離銅氧化成氧化銅而除去氮?dú)庵械难鯕?。催化劑床需要用含有少量氫氣的熱氮?dú)膺M(jìn)行定期再生。離開氮?dú)饷撗豕薜牡獨(dú)膺M(jìn)入氮?dú)飧稍锲?C-1112)。氮?dú)飧稍锲鲀?nèi)設(shè)有分子篩,經(jīng)過物理吸收作用除去氮?dú)庵械乃趾推渌鼧O性雜質(zhì)。分子篩需要用熱氮?dú)舛ㄆ谠偕Ｒ慌_氮?dú)飧稍锲髟偕鷷r(shí),另外一臺備用干燥器啟動運(yùn)行,以保證氮?dú)獬掷m(xù)地流入反應(yīng)系統(tǒng)。高壓精制的氮?dú)庥糜诜磻?yīng)系統(tǒng),而低壓精制的氮?dú)夤┙o整個PE工藝單元各個不同地方使用。氮?dú)飧稍锲鞯某隹诘木频獨(dú)饨?jīng)過壓縮后即可供反應(yīng)系統(tǒng)使用。精制氮?dú)庥傻獨(dú)鈮嚎s機(jī)(K-1102)增壓至大約3309kPag(480psig)的壓力后經(jīng)由精制氮?dú)膺^濾器(Y-1114)進(jìn)入反應(yīng)系統(tǒng)。氫氣的精制由界區(qū)來的氫氣進(jìn)入甲醇轉(zhuǎn)化器加熱器(E-1204)預(yù)熱后,進(jìn)入甲烷轉(zhuǎn)化器(C-1205)。甲烷轉(zhuǎn)化器內(nèi)有固定的催化劑床,在氫氣的作用下,將一氧化碳和二氧化碳轉(zhuǎn)化成甲烷和水。從甲烷轉(zhuǎn)化器出來的氫氣在甲烷后冷器(E-1206)中冷卻到大約40攝氏度后,進(jìn)入到氫氣干燥器(C-1207)。氫氣干燥器中的分子篩能夠經(jīng)過物理吸附的作用,將氫氣中的水脫除。分子篩需要使用熱氮進(jìn)行周期性的再生。再生時(shí),氫氣干燥器的旁路會打開,以保證氫氣連續(xù)地流入反應(yīng)系統(tǒng)。

從氫氣干燥器出來的氫氣送入反應(yīng)系統(tǒng)或進(jìn)入精制系統(tǒng)內(nèi)的脫氧罐。ICA的精制

UNIPOLPE工藝采用異戊烷作為誘導(dǎo)冷凝劑以增強(qiáng)反應(yīng)系統(tǒng)內(nèi)的除熱速率。來自界區(qū)的異戊烷直接進(jìn)入ICA脫氣塔(C-1421)。此塔安裝在ICA緩沖罐(C-1406)之上,塔頂配有水冷的ICA冷凝器(E-1422)使異戊烷冷凝,塔底有一個蒸汽加熱的ICA再沸器(E-1415)使異戊烷汽化。含有脫除的輕組分的一小股塔頂氣被排放到火炬。從ICA緩沖罐底部出來后,進(jìn)入ICA冷卻器(E-1423)。冷卻器的主要目的是為ICA進(jìn)料泵(G-1412或G-1413,其中一個是在線備用泵)提供足夠的有效氣蝕余量。ICA進(jìn)料泵使ICA增壓至大約3137kPag(455psig)后進(jìn)入反應(yīng)器。被送入反應(yīng)器之前,ICA要經(jīng)過ICA干燥器(C1419或C-1420)。ICA干燥器利用分子篩經(jīng)過物理吸附的方式除去其中的水分和其它極性雜質(zhì)。分子篩床層需要用熱氮?dú)舛ㄆ谠偕．?dāng)一個ICA干燥器進(jìn)行再生時(shí),就啟用備用的ICA干燥器,這樣使ICA連續(xù)地流入反應(yīng)系統(tǒng)。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)來自界區(qū)的乙烯經(jīng)過乙烯級間換熱器(E-2105)的外殼,與來自乙烯CO脫除罐(C-2107)中的乙烯進(jìn)行級間換熱。升溫后的乙烯在進(jìn)入乙烯預(yù)熱器(E-2106)加熱到100℃后,進(jìn)入到乙烯脫氧罐(C-2109),隨后進(jìn)入乙烯CO脫除罐。乙烯經(jīng)過乙烯預(yù)熱器將乙烯加溫到最終溫度后,進(jìn)入到乙烯脫氧器,開車的時(shí)候也會使用乙烯預(yù)熱器來進(jìn)行預(yù)熱。

乙烯脫氧罐內(nèi)有一個游離銅催化劑的固定床,經(jīng)過將游離銅氧化成氧化銅而除去乙烯中的氧氣。這種床需要用氫氣稀釋的氮?dú)膺M(jìn)行定期再生。乙烯CO脫除罐內(nèi)有一個氧化銅固定床。這種床層要用氧氣稀釋的氮?dú)膺M(jìn)行定期再生。從乙烯脫氧罐和乙烯CO脫除罐出來的乙烯,經(jīng)乙烯級間換熱器冷卻到40℃后,進(jìn)入乙烯干燥器(C-2112或C-2113),乙烯干燥器中含有分子篩和活性氧化鋁,這兩種物質(zhì)經(jīng)過物理吸附作用除去乙烯物流中的CO2、水分和其它極性雜質(zhì)。乙烯干燥器需要用熱氮?dú)舛ㄆ谠偕．?dāng)一臺乙烯干燥器再生時(shí),另一臺備用設(shè)備啟用,這樣可使乙烯持續(xù)地流入到反應(yīng)系統(tǒng)。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。再生的周期由計(jì)時(shí)器和邏輯內(nèi)部連鎖控制。閥是現(xiàn)場手動操控的。來自氮?dú)饪偣艿牡獨(dú)庠诹髁靠刂葡逻M(jìn)入再生氮?dú)饧訜崞?E-2114)。氮?dú)獗浑娮杓訜崞骷訜岬降?部分和第2部分中的可再生精制床再生所需的溫度。熱氮?dú)饨?jīng)過輸送管道進(jìn)入需再生床層。所有的干燥器再生時(shí)的冷卻和預(yù)負(fù)荷使用低壓未精制氮?dú)?。精制床再生時(shí)產(chǎn)生的排放氣或者送入火炬或者排入大氣。

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.反應(yīng)(部分4)

反應(yīng)物質(zhì)一般在壓力為2413kPag(350psig)、溫度約80到100℃的流化床反應(yīng)器內(nèi)發(fā)生聚合生產(chǎn)出樹脂。經(jīng)過外部的反應(yīng)氣冷卻循環(huán)使反應(yīng)器床流化,同時(shí)除去反應(yīng)熱。催化劑和精制的反應(yīng)物(乙烯、丁烯-1或己烯-1和氫氣)連續(xù)被送入反應(yīng)器。樹脂從反應(yīng)器間歇地流入到2條交替作業(yè)的產(chǎn)品卸料系統(tǒng)。在產(chǎn)品卸料過程中,一些夾帶的反應(yīng)氣被送到另一個卸料系統(tǒng)。這些在卸料系統(tǒng)臨時(shí)儲存的反應(yīng)氣在下一個卸料周期間接地返回反應(yīng)器,這樣能夠減少反應(yīng)系統(tǒng)中反應(yīng)氣的損失。樹脂被送往產(chǎn)品脫氣倉(第5A部分中的C-5009),同時(shí)輸送氣進(jìn)入排放氣回收系

統(tǒng)(第5B部分)。

出于各種原因會向反應(yīng)器加入某些改性劑。當(dāng)生產(chǎn)齊格勒—那塔樹脂時(shí),向反應(yīng)器內(nèi)連續(xù)地注入烷基鋁。在反應(yīng)出現(xiàn)故障情況時(shí),向反應(yīng)器內(nèi)注入另一種改性劑以快速地”終止”聚合反應(yīng)。這種改性劑是一種可逆的催化劑毒物,它能經(jīng)過手動或終止系統(tǒng)邏輯控制的自動啟動而注入到反應(yīng)器。樹脂產(chǎn)品的性質(zhì)主要由所采用的催化劑的類型和循環(huán)氣的組成所控制。催化劑的類型決定了分子量的分布。循環(huán)氣中共聚單體的量決定了樹脂的密度,循環(huán)氣中氫氣的量決定了樹脂的熔融指數(shù)。工藝計(jì)算機(jī)系統(tǒng)經(jīng)過對反應(yīng)器中的樹脂性質(zhì)進(jìn)行瞬時(shí)的預(yù)測,同時(shí)按需要調(diào)整變量,來達(dá)到對這些性質(zhì)的閉路控制。

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.反應(yīng)系統(tǒng)反應(yīng)系統(tǒng)由反應(yīng)器(C-4001)、循環(huán)氣冷卻器(E-4002A或E-4002B,一個備用,非連接)和循環(huán)氣壓縮機(jī)(K-4003)組成。氣態(tài)反應(yīng)物(乙烯、丁烯-1或己烯-1,和氫氣的混和物)和惰性組分在循環(huán)氣壓縮機(jī)的壓送下連續(xù)地循環(huán)經(jīng)過注入有催化劑的樹脂流化床。聚合反應(yīng)的反應(yīng)熱由循環(huán)氣帶出并被外部的循環(huán)氣冷卻器除去。如果需要的話,少量的循環(huán)氣可經(jīng)過產(chǎn)品脫氣倉排放到火炬,以此來保持反應(yīng)系統(tǒng)內(nèi)適當(dāng)?shù)姆磻?yīng)物濃度。反應(yīng)器是一個圓柱狀帶裙座設(shè)備,頂部帶有一個膨脹的部分以分離循環(huán)氣中的固體顆粒。一個多孔的分布板支撐樹脂粉料床,氣體經(jīng)分布板分布后流入床層底部。有不同標(biāo)高的人孔,以備檢修人員能進(jìn)入反應(yīng)器。循環(huán)氣壓縮機(jī)是一個單級、開式葉輪、恒速、離心式壓縮機(jī)。壓縮機(jī)入口的導(dǎo)向葉片控制循環(huán)氣的循環(huán)速率。循環(huán)氣壓縮機(jī)的設(shè)計(jì)是在干氣體密封系統(tǒng)的條件下運(yùn)行。循環(huán)氣冷卻器是一個單程的管殼式換熱器。循環(huán)氣走管程,同時(shí)調(diào)溫水逆流走殼程。調(diào)溫水系統(tǒng)是一個控制溫度的再循環(huán)系統(tǒng)。經(jīng)過離心式調(diào)溫水泵(G-4004,G-4005,一個備用)使得調(diào)溫水在冷卻系統(tǒng)中循環(huán)。改變調(diào)溫水冷卻器(E-4007)旁路調(diào)溫水的速率控制進(jìn)入循環(huán)氣冷卻器的調(diào)溫水的溫度。調(diào)節(jié)調(diào)溫水系統(tǒng)的溫度設(shè)定點(diǎn)來控制反應(yīng)器溫度。因?yàn)檎{(diào)溫水系統(tǒng)溫度不是一個固定值,而是一個溫度范圍,設(shè)置一個膨脹罐(D-4010)使調(diào)溫水適應(yīng)不同的熱脹。調(diào)溫水系統(tǒng)也用于在裝置初始開車時(shí)加熱反應(yīng)系統(tǒng)。當(dāng)蒸汽經(jīng)過噴霧器送入到調(diào)溫水系統(tǒng)時(shí),調(diào)溫水可作為臨時(shí)熱媒。反應(yīng)器壓力經(jīng)過改變乙烯進(jìn)料速率來控制。共聚單體和氫氣與乙烯的比例經(jīng)過循環(huán)氣在線分析儀來測量,流量根據(jù)需要的循環(huán)氣體組成自動控制。裝置開車前,必須向反應(yīng)器裝入聚乙烯樹脂粉料來作為種子床。樹脂經(jīng)過反應(yīng)器垂直段上部的管嘴加入反應(yīng)器。樹脂經(jīng)過專用的風(fēng)送線從種子床樹脂儲倉(第5E部分)輸送到反應(yīng)器?？山?jīng)過注入改性劑C來終止聚合反應(yīng)或使聚合反應(yīng)減慢。終止系統(tǒng)包括終止劑鋼瓶、輸送管道以及用來將終止劑注入循環(huán)氣管道的氣動閥。當(dāng)以下幾種工況發(fā)生時(shí),終止系統(tǒng)邏輯將會啟動:終止系統(tǒng)可手動啟動也可在反應(yīng)器床溫過高時(shí)自動啟動。改性劑經(jīng)過循環(huán)氣物流在反應(yīng)系統(tǒng)內(nèi)循環(huán)和混合,這樣就可將反應(yīng)器床層的催化劑脫活。終止系統(tǒng)除了在循環(huán)氣壓縮機(jī)機(jī)械故障停車時(shí)自動啟動外還可在循環(huán)氣流量降低時(shí)自動啟動。當(dāng)循環(huán)氣經(jīng)過循環(huán)氣透平(KT-4003)排至火炬時(shí),改性劑被注入循環(huán)氣管道。循環(huán)氣透平以逐漸越小的速率驅(qū)動循環(huán)氣壓縮機(jī),改性劑在反應(yīng)系統(tǒng)內(nèi)循環(huán)和混合,這樣就可將反應(yīng)器床層的催化劑脫活。

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.催化劑處理和加料添加淤漿催化劑生產(chǎn)齊格勒－那塔聚乙烯樹脂時(shí),用的是淤漿催化劑。淤漿催化劑由原質(zhì)催化劑和還原劑混和制得。原質(zhì)催化劑淤漿存儲在可重復(fù)使用的鋼瓶中。在卸料前,要滾動原質(zhì)催化劑輸送鋼瓶以確保固體完全懸浮在礦物油中。設(shè)置鋼瓶滾瓶機(jī)(S-4060)來實(shí)現(xiàn)此目的。滾動后的鋼瓶快速從儲存區(qū)傳送至催化劑供應(yīng)區(qū)。用氮?dú)鈱⒃|(zhì)漿液從鋼瓶中壓至淤漿進(jìn)料罐(C-4050)。淤漿進(jìn)料罐攪拌器(Y-4052)連續(xù)攪拌以保證固體很好地分散,并保持在懸浮狀態(tài)。原質(zhì)漿液需要加入添加劑T3和添加劑DC還原。這些添加劑稀釋于礦物油中存儲在鋼瓶中。氮?dú)鈱⑻砑觿㏕3和添加劑DC從鋼瓶中壓出送入各自的進(jìn)料罐(C-4067和C-4065)。進(jìn)料罐設(shè)計(jì)有一個小的緩沖空間,以實(shí)現(xiàn)在更換鋼瓶時(shí)系統(tǒng)仍能連續(xù)操作。淤漿進(jìn)料罐中的原質(zhì)漿液由可變速控制的淤漿進(jìn)料泵(G-4051或G-4055,一個在線備用)或者以再循環(huán)模式重新返回淤漿進(jìn)料罐或者以注入模式送入反應(yīng)器。原質(zhì)漿液流率由質(zhì)量流量計(jì)測量。DC進(jìn)料泵(G-4053)、T3進(jìn)料泵(G-4054)和它們共用的備用泵T3、DC進(jìn)料泵(G-4058)用于將添加劑T3和添加劑DC連續(xù)不斷的從它們各自的進(jìn)料罐送入淤漿進(jìn)料泵下游的原質(zhì)漿液線。烷基鋁的流量由質(zhì)量流量計(jì)測量,其流量根據(jù)原質(zhì)漿液的質(zhì)量流率來控制。添加劑T3和添加劑DC從不同的注入點(diǎn)注入原質(zhì)漿液線。添加劑T3在緊靠淤漿進(jìn)料泵下游處注入原質(zhì)漿液線。T3和原漿的混和物流入T3停留罐和攪拌器(C-4056),并在那里進(jìn)行反應(yīng)。添加劑DC注入從T3停留罐出來的T3和原漿的混和物流。反應(yīng)在DC停留罐和攪拌器(C-4057)中繼續(xù)進(jìn)行。還原后的催化劑送入反應(yīng)器。作為輸送氣的高壓精制氮?dú)饪蓞f(xié)助將漿液注入到反應(yīng)器。CatalystHandlingandFeeding–MineralOilFlushSystemAmineraloilflushsystemisprovidedtofacilitateperiodicflushingofalllinesandequipmentwithintheSlurryCatalystSystem.MineraloilusedforflushingispumpedfromdrumswiththeMineralOilDrumPump(G4068),intotheMineralOilBlowTank(C4069),wherenitrogenisusedtopressurethemineraloilthroughoutthesystem.PrecursorlinesandequipmentwillbeflusheddirectlytoaportableSlurryDisposalTank.AdditiveT3andAdditiveDClinesandequipmentwillbeflushedtotheSealPot(C4045),andthendrainedintotheportableSealPotDisposalTank.ADisposalTankScale(S4064)isprovidedtomonitortheleveloftheSealPotDisposalTankandSlurryDisposalTankcontents.Periodically,thecontentsoftheSealPotDisposalTankandtheSlurryDisposalTankaresenttoanoffsitedisposalcontractorfordisposal.催化劑處理和加料系統(tǒng)礦物油沖洗系統(tǒng)礦物油沖洗系統(tǒng)用于定期沖洗淤漿催化劑系統(tǒng)內(nèi)的所有管線及生產(chǎn)設(shè)備。用于沖洗的礦物油由礦物油卸料泵(G-4068)從礦物油桶送入礦物油排放罐(C-4069),使用氮?dú)廨斔偷V物油到整個系統(tǒng)。原質(zhì)漿液的管線和設(shè)備經(jīng)過沖洗后,廢礦物油會直接排到一個便攜式的淤漿處理罐內(nèi)。添加劑T3,添加劑DC,的管線及設(shè)備經(jīng)過沖洗后,廢礦物油進(jìn)入密封罐(C-4045),之后被排入便攜式的密封罐處理罐。處理鋼瓶秤(S-4064)用于監(jiān)測密封罐處理鋼瓶及淤漿處理罐的液位和物質(zhì)。密封罐處理罐中的物質(zhì)和淤漿處理罐中的物質(zhì)會定期地送到廠外廢物處理承包商那進(jìn)行處理。CatalystHandlingandFeeding–DryCatalystFullyformulateddrycatalystisfedtotheReactorbytwo(2)ModularCatalystFeeders(V4036andV4037)whichareofproprietaryUnivationdesign.TheModularCatalystFeedersaresufficienttomeetdesignca