化工专业英语

SpecializedEnglishforchemistry化工专业英语化工专业英语一课件第1页1/35ChemicalEnineeringandTechnology

Lesson3CatalystsforIndustrialProcessesThecriteriaforanindustriallysuccessfulcatalystareverystringent.Criteria（批评、判断等）标准，准则(criterion名词复数Stringentadj. 严格;迫切;（货币）紧缩Thetwomostimportantconsiderationsareactivityanddurability;suitabilityforbasicstudyisnotafactor,andthishasretardedprogressinourunderstandingofhowsuchtechnicalcatalystsreallyoperate.化工专业英语一课件第2页2/35Letusconsiderthetwoprimerequirements.primeadj.最好;首要;最初;基本n.精华;早期;全盛时期;青年vt.使准备好;填装;事先指导First,thecatalystmustbeabletoeffectthedesiredreactionatanacceptablerateunderconditionsoftemperatureandpressurethatarepracticable.化工专业英语一课件第3页3/35Chemicaltechnologyhasadvancedtothepointwheretemperaturesashighas1600Kandpressureupto350atm(35MPa)presentnodifficultiesandthermodynamicconsiderationssometimesnecessitatetheirusetoattainreasonableequilibriumyieldsofproducts.

Necessitatevt. 使…成为必要，需要;强迫，迫使equilibriumn. 平衡，均势;平静化工专业英语一课件第4页4/35Ifhowevergoodyieldscanbeobtainedatlowtemperaturesandpressures,thenthereiseveryincentivetofindacatalystthatwilloperateunderthemildestpossibleconditions,sincetheuseofextremeconditionsisverycostly.Incentiven.动机;刺激;诱因;勉励adj.刺激性;勉励性质Mildest适当适中Itisconcurrentlyimportantthatside-reactionsareminimal,especiallythoseleadingtopoisoningordeactivationthroughcarbondeposition.化工专业英语一课件第5页5/35Second,thecatalystmustbeabletosustainthedesiredreactionoverprolongedperiods:insomeprocesses,acatalystlifeofseveralyearsisnotuncommon,andiseconomicallynecessary.Prolongvt. 延长，拉长;拖延，延期Clearlythelongeritlasts,thesmallerthecontributionthatitsinitialcostmakestotheoverallcostoftheprocesswillbe.initialadj. 最初;开始;首字母化工专业英语一课件第6页6/35Initialcostisrarelyofover-ridingimportance:itisusuallycheaperinthelongruntouseanexpensivecatalystthatwilllastalongtimethanacheaponethathastobereplacedfrequently.Thechiefcausesofdeteriorationinuseare:reversiblepoisoningduetoimpuritiesinthereactantsortoside-reactions,andirreversiblephysicalchangesincludinglossofsurfacearea(sintering)ormechanicalfailure.Deteriorationn.恶化;变坏;退化;堕落Irreversibleadj.不可逆;不能翻转;不能倒置sinteringn.泉华，烧结物，熔渣vt.使烧结化工专业英语一课件第7页7/35Reversiblepoisoningmaywithluckberectifiedbysimpletreatment,suchasoxidationorwashing,withoutremovingthecatalystfromthereactor.Rectifiedadj.[医]矫正，调整v.更正，矫正(rectify过去式和过去分词);精馏Toguardagainstphysicalchanges,carefulattentionhastobegiventothestrengthofthecatalyst.guardn.警卫;狱吏，看管;护卫队;防护装置vt.保卫，守护;看管;加防护装置;慎重使用vi.警觉;警卫化工专业英语一课件第8页8/35Thepreferredphysicalformforacatalystisdeterminedentirelybythemannerinwhichitistobeused.Itsparticlesizeisespeciallyfixed,atleastwithinbroadlimits,bythetypeofreactortobeemployed.Aroughcriterioniswhetherornotonecandistinguishseparateparticleswiththenakedeye.Criterionn.（批评、判断等）标准，准则;规范Whenthereactantsaresolelygasesorvapors,thereareonlytwopossiblebasictypesofreactorthatcanbeused.solelyadv. 唯一地;仅仅;独一无二地;纯粹化工专业英语一课件第9页9/35Whenthereactantsaresolelygasesorvapors,thereareonlytwopossiblebasictypesofreactorthatcanbeused.solelyadv. 唯一地;仅仅;独一无二地;纯粹Fixed-bedreactorFluidized-bedreactor化工专业英语一课件第10页10/35Tubularreactorkettlereactor化工专业英语一课件第11页11/35PackedtowerreactorTowerreactor化工专业英语一课件第12页12/35Afixed-bedreactorisoneinwhichatubeispackedwith“coarse”catalystparticlesthroughwhichthereactantsflow.Coarseadj. 粗鄙;粗糙;粗野;粗制滥造Asaresultoftheobstructiontogasflowbytheparticles,apressuredropoccursacrossthebed,andapositivepressurehastobeappliedattheinlettosecureanadequateflow-rate.化工专业英语一课件第13页13/35Thesizeofthepressuredropincraseswithincreasingflow-rateandbedlength,andwithdecreasingparticlesize.Manydifferentshapesandsizesofcatalystparticlesareusedinfixed-bedreactors,andagreatdealofskillandexperiencegoesintochoosingthemostappropriateforagivensetofconditions.appropriateadj. 适当;恰当;适当v. 盗用;侵吞;拨（专款等）化工专业英语一课件第14页14/35SphericalTrifoliumCylindricalSaddle化工专业英语一课件第15页15/35Dimensionsofmorecommonformsareusuallybetween2mmand2cm.Dimensionsvi.按规格尺寸切割vt.在…上标尺寸n.面积;特点;（长、宽、厚、高等）尺寸;主要性;尺寸(dimension.When,asinthecaseof

ammoniaoxidation,itisdesiredtouseapuremetalcatalystathightemperatureandaveryshorttime.Ammonian.氨;氨水;氨气化工专业英语一课件第16页16/35Soabedof20to30finely

wovenmetalgaugesisused,thisisanothercatalystformsuitedforuseinafixed-bedreactor.Wovenv.编，织，织成(weave过去分词);编排;杜撰;（把…）编成gaugesn.测量标准或范围;尺度，标准;测量仪器;评定vt.（用仪器）测量;确定容量，体积或内容;评定，判断;采取化工专业英语一课件第17页17/35Sincemanycatalyzedreactionsarestronglyexothermic,fixed-bedreactorsmustcontainafacilityforremovingtheunwantedenthalpyofreaction.exothermicadj. 发烧，放出热量Enthalpyn. [热]焓;[物]热函;热含量HJacketSnaketubeTubularheatexchanger化工专业英语一课件第18页18/35Thismaybedoneinoneortwoways.Amultitubularreactorcontainsalargenumberofreactiontubes,typically2.5cmindiameter,withacoolinggasorliquidflowingbetweenthem.tubularadj. 管系组织;管子形，管状;管子做成;发吹管般声音化工专业英语一课件第19页19/35Alternativelythebedmaybesplitintosections,withprovisionforcoolingthegasinthespacesbetween.Alternativelyadv.二者择一地;要不然;或者IntermediateindirectheattransferQuenchingwithfeedgas化工专业英语一课件第20页20/35Afurtherimportantandquitedifferentcatalystformisfindingapplication,especiallyinair-pollutioncontrol.Thisistheso-called

monolithicstructure,whichconsistsofablockofceramicmaterial(α-aluminaormullite),throughwhichrunsfineparallelchannels.

monolithicadj.独块巨石;整体;庞大Ceramicdj.陶器，与陶器相关;陶瓷，陶制;制陶n.陶瓷制品;陶瓷器;制陶艺术;陶瓷装潢艺术aluminan.氧化铝，矾土;铝土Mulliten.多铝红柱石;莫来石paralleladj.平行;相同，类似;[电]并联;[计]并行化工专业英语一课件第21页21/35Thestructurescanbemadeinmanydifferentways,eachofwhichresultsinacharacteristicchannelshape.Theblocksareobtainableinarangeofshapesandsizes,andasingleblockwheninsertedinacontainerthereforebehavesasafixed-bedreactor.化工专业英语一课件第22页22/35Becauseofthelowporosityofthematerialfromwhichthesestructurearemade,itisusuallynecessarytoattachathinlayerofamoreporoussubstancetowhichthecatalyticallyactivephasecanadhere.porosityn. 多孔性，有孔性Adherevi.黏附;附着;坚持;追随vt.使粘附;遵照，坚持;追随，依附化工专业英语一课件第23页23/35Suchmonolithicstructureshaveseveralclearadvantagesoverpelletsorgranulespackedlooselyinatube.Monolithicadj.独块巨石;整体;庞大Pelletsn.小球;小子弹;石弹，炮弹;（货币等）圆浮雕v.用小球扔;用子弹射击;将…制成丸状;把…弄成小球形granulesn.小颗粒，小硬粒(granule名词复数)化工专业英语一课件第24页24/35First,thepressuredropthroughthebedislessforequalquantitiesofcatalyst,thuspermittinghigherspacevelocitiestobeachieved;Velocitiesn. 速度(velocity名词复数);高速，快速化工专业英语一课件第25页25/35secondly,thereisnoattritionofthecatalystduetoparticlesrubbingagainsteachotherandformingfinedust.Attritionn. 消耗;消磨;摩擦;（神学）不彻底忏悔Rubbingn. 拓本，拓印finedust细粉尘;纤尘化工专业英语一课件第26页26/35Theirabilitytowithstand

thermalshockishoweverinsomecaseslimited.Withstandvt.经受，承受，禁得起;反抗vi.反抗;耐得住，禁得起Thesecondbasickindofreactorforgaseousreactionsisthefluidizedbed.Gaseousadj. 气态，似气体;无实质;〈美俚〉不可靠;气性化工专业英语一课件第27页27/35Herethecatalystconsistsoffineparticles.Andwhenthegasflowupwardsthroughabed,suchpowderattainingacritical

velocitythebedappearsto“boil”:itexpandssignificantly,andtheparticlesareincontinuousmotion.Criticaladj.批评，爱挑剔;关键;严重;极主要Velocityn. 速率，速度;周转率;高速，快速化工专业英语一课件第28页28/35Inthisstatethebedissaidtobefluidized.Fluidizedadj.流态化，沸腾v.使液化，流（态）化(fluidize过去式和过去分词)化工专业英语一课件第29页29/35Thebehaviorgivescertainadvantagesoverfixedbeds,forexample,heattransfercharacteriaticsaremuchbetter,andthepressuredropincreasesfarlessquicklywithincreasingflow-rate.

化工专业英语一课件第30页30/35ExercisesVocabulary1Cataystsaresubstanceswhichbytheirmerepresenceevokechemicalreaction.AchangeBimpedeCfortifyDcause2Theessenceofcatalystsisnottheenteringbutthefallingout.AreactionBconsumptionCdepartureDappearance3Inpracticethisdefinitionprovestoorestrictive.AboardBactivatedCvagueDspecific化工专业英语一课件第31页31/354Acatalystisgenerallynotusedupitselfinachemicalreaction.ArequiredBactivatedCconsumedDenergetic5Theactivationenergybarriermustbesurmountedforreactiontotakeplace.AconqueredBpermittedCremovedDdetermined6Catalyststhataccelerate

hydrolysisofestersmustalsoaccelerateesterificationofalchols.AproceedBdevelopCfastenDchain化工专业英语一课件第32页32/357Adistinctionismadebetweenhomogeneouscatalystsandheterogeneouscatalysis.AcomparisonBdifferenceCdecisionDproportion8Anewreactionmechanismpermitsthereactiontooccurviaadifferentactivatedcomplex.AthroughBwithinCbeyondDoutside化工专业英语一课件第33页33/35Fillintheblankswiththefollowingphrases.useup,bereferredto