分離工程大作業(yè)乙腈與水變壓精餾模擬過程

分離工程大作業(yè)乙腈與

水變壓精餾模擬過程集團標準化工作小組[Q8QX9QT-X8QQB8Q8-NQ8QJ8-M8QMN]流程的確定低壓塔 高壓塔建立如圖所示的流程圖。流程的描述：原料在合適的位置進入低壓塔TOWER1,塔頂出共沸組成，塔底為水出口；塔頂共沸組成經(jīng)泵加壓后進入高壓塔TOWER2,塔底為合格的已經(jīng)產(chǎn)品，塔頂為高壓下共沸物，循環(huán)回一塔TOWER1。物性方法的選擇根據(jù)文獻介紹，用ASPEN物性數(shù)據(jù)庫中的NRTL模型計算得出的乙腈-水共沸物的汽液平衡數(shù)據(jù)和實際值基本一致，故選用NRTL模型為本次模擬的物性方法。模擬參數(shù)進料組成為60%的乙腈和40%的水(質量分數(shù)),假定流量為100kg/h。分離出的產(chǎn)品：％乙腈(質量分數(shù))。兩塔的壓強的確定根據(jù)變壓精餾的原理可得，不同壓力下的共沸組成差別越大，循環(huán)的物流量就越少，循環(huán)量越少，那么能耗就會相應地降低；但是高壓或者是真空下操作又會影響我們塔的投資費用。

經(jīng)過文獻調研，吸取他人的工程經(jīng)驗最終選擇和。作為塔的操作壓力。流程的模擬根據(jù)變壓精餾的原理可得：當壓力確定時，流程中每一股物流的量大致是確定的?？梢愿鶕?jù)公式(書上的公式)計算出。也就是說，塔的塔頂采出率和塔底采出率都是定值，也只有在這個定值下，流程才能夠物料守恒而收斂。同時由于，如果兩塔同時給定塔頂采出率或者塔底采出率時，很難收斂。故選擇TOWER1給定塔頂采出率，TOWER2給定塔底采出率。所以，先計算出大概的初值，然后再在附近調試，是流程能夠順利收斂。最終初次收斂時的參數(shù)如下圖所示：TOWER1的初始參數(shù)如下圖所示：3-PhaseConfiguration!^Streams)/P值飆回VCordenier] ThermosiphonConfig.]4Reboiler)3-PhaseCalculationtppe:Nurnberofstages:: j |40StagewizardCondenser:Total▼Reboiler:KettleTValidphases:Vapor-Liquid▼Convergence:Standard▼OperatingspecificationsRefluwratio 二Mole二4Distillatetofeedratio▼Mass▼0.901Freewaterrefluxratio:1Feedbasis'/CoriHguratioriystreams|'/CoriHguratioriystreams|^Pres：sure|VCordenseF|^ThermosiphoriConfig.|^R&boiler|3-Phase'/CoriHguratioriystreams|'/CoriHguratioriystreams|^Pres：sure|VCordenseF|^ThermosiphoriConfig.|^R&boiler|3-PhaseFeedstreamsNameS^ageConventionFEED25Above-Stage5iaAbove-StageProductstreamsNameStagePhaseBasis Flow UnitsFlowratio21LiquidMolekmol/hrH2040LiquidMolekmd/hryCorifigurstion1ystr&ams1*/Pre￡s：uT/匚口竹膽門總臼ThermosiphoriConhg.|*/Reboiler|3-PhaseyCorifigurstion1ystr&amsView;|lop/Bottom二]Topstage/CondenserpressureStage1/Condenserpressure:Stage2pressureIuptional]—(*Stage2pressure:bar ▼「匚口門de：n&曰pressuredrop:N/sqm _Fressurwdropforrestofcolunnn(uptional)(?Stagepressuredrop:「Columnpressuredrop:N/sqmN/sqmTOWER2初始參數(shù)如下圖所示:^/Configuration*/Sheams|-*/PressureCondenser7herrnosiphonConfig.|^/Reboiler|3-PhaseSetupoptions—Calcuhliontype:Numberof盤白口片京20 當Stmgewizard|Conderiser:Total ▼Reboiler:Kettle 二Validphases:Vapor-Liquid 二Convergence:Standard ▼OperatingspecificationsRefluxratioMole2|口匚|1：1：口「「18et曰|MassTGOkq/hr ▼Freewaterrefluwratio: Fumdb日享iwConfiguration1/StreamsPressure)Condenser|ThermosiphonConfig.|^/Reboilerj3-Phase|NameStageConvention?4Above-StageProductstreamsNameStagePhaseBasis Flow UnitsFlowratioFeedspecs51LiquidMolekmol/hrFeedb.3sisC2H3N10LiquidMolekmoL？hrFeedbasisS-1:S-1:進料位置為3；最終選擇10塊板。3-Phase-JConfiguration|VStreams^Pressure|JCcndenseT|^ThermcsiphonConfig.|VReboiler|3-PhaseView;|Top/BottomView;|Top/Bottom三］Topstage/CondenserpressureStage1/Condenserpressure: Topstage/CondenserpressureStage1/Condenserpressure: 口目|barStage2pressure(optional)百Stage2pressure(optional)百Stage2pressure;C'Condenserpressuredrop:bar ▼N/sqm _□,oaeebar▼N/sqnftJPressuredropfarres^afcolunin[optional]c*Stagepressuredrop:CColumnpressuredrop:流程的優(yōu)化(這個想一想)根據(jù)變壓精餾的原理分離要求對回流比無明顯要求，,，都能滿足分離要求。(可能沒到那個限度吧思考ing)鑒于此，將回流比分別定為和；在此回流比下對塔板數(shù)進行靈敏度分析，觀察塔板數(shù)和進料位置對產(chǎn)品純度的影響。低壓塔的靈敏度分析：S-1：進料位置為3；最終選擇8塊板。Row/CaseStatusVARY1TOWER1PARAMNSTAGEH2OMA1 OKs0.99855912 OK60.99931633.3 OK70.999995214 OK80.999999735 OK90.999399986 OK1017 OK111e ok1219 OK13110 OK14111 OK151▼IS-2：塔板數(shù)為8；最終選擇3.Row^CaseStatusVARY1TOWER1FEEDFEEDSSTAGEH20MA1□K.s0.999999732□K.40.999999513口匕50.999995234OK60.999919565□K.70.99858255高壓塔的靈敏度分析：

Row/CaseStatusVARY1T0WER2PARAMNSTAGEC2H3NMA11OK30.999115262OK90.9997028G3OK100.999900724□K110.999966945□K120.999989016□K130.999996357□K140.999998798□K150.9999996S-2：塔板數(shù)為10；最終選擇3.Row/CaseStatusVARY1TOVER2FEEDSSTAGEC2H3NMA?1□K30.999900792□K40.999703943□K50.999120884□K60.997428075□K10.992752876□K80.981050881OK90.95605027最終優(yōu)化結果為：TOWER1^/ConfiguratiDn^^/ConfiguratiDn^JStreamsj^/ConfiguratiDn^^/ConfiguratiDn^JStreamsj『『Configwmtion] 什emm*]^Pressurej^CondenserjThermosiphonConFig.|^Reboilerj 3-PhaseSetupoptionsCalculationt卯日Numberofstages:Condenser:Reboiler:Validphases:Convergence:■jilibriumEl8S3口已所e4d|T口閆Kettle,Vapor-Liquid色Standard二Operatingspecihcations0.0010.901yConfigurationyStreamsj^Pressure^yCondenserjThermosiphonConfig,jyReboilerj3-PhaseFeedstreamsNameStageConvention?FEED圖EAbove-Stage52Above-StageProductstreamsNameStagePhaseBasis Flow UnitsFlowratioFeedspecs21LiquidMolekmol/hrFeedbasisH208LiquidMolekmol/hrFeedbasisTOWER2

SetupoptionsCalculationtvpe：Numberafstage?;Condenser:Reboiler:Validphases:Reboiler:Convergence:OperatingspecificationsRefluxratio▼Mole▼a.005Elottornsrateh同ass▼OperatingspecificationsRefluxrati