化学工程与工艺专业英语胡鸣-UNIT-1ppt课件

化学工程与工艺专业英语授课班级：化工05授课教师：郎中敏学时：32.Unit1ChemicalIndustryBeforereadingthetextbelow,trytoanswerfollowingquestions: 1.Whendidthemodernchemicalindustrystart? 2.Canyougiveadefinitionforthechemicalindustry? 3.Whatarethecontributionswhichthechemicalindustryhasmadetomeetandsatisfyourneeds? 4.Isthechemicalindustrycapital-orlabor-intensive?Why?.1.OriginsoftheChemicalIndustryAlthoughtheuseofchemicalsdatesbacktotheancientcivilizations,theevolutionofwhatweknowasthemodernchemicalindustrystartedmuchmorerecently.ItmaybeconsideredtohavebegunduringtheIndustrialRevolution,about1800,anddevelopedtoprovidechemicalsforusebyotherindustries.Examplesarealkaliforsoapmaking,bleachingpowderforcotton,andsilicaandsodiumcarbonateforglassmaking..Itwillbenotedthattheseareallinorganicchemicals.Theorganicchemicalsindustrystartedinthe1860swiththeexploitationofWilliamHenryPerkin’sdiscoveryofthefirstsyntheticdyestuff—mauve.AtthestartofthetwentiethcenturytheemphasisonresearchontheappliedofchemistryinGermanyhadpaidoffhandsomely,andby1914hadresultedintheGermanchemicalindustryhaving75%oftheworldmarketinchemicals.ThiswasbasedonthediscoveryofnewdyestuffsplusthedevelopmentofboththecontactprocessforsulphuricacidandtheHaberprocessforammonia..Thelatterrequiredamajortechnologicalbreakthroughthatofbeingabletocarryoutchemicalreactionsunderconditionsofveryhighpressureforthefirsttime.TheexperiencegainedwiththiswastostandGermanyingoodstead,particularlywiththerapidlyincreaseddemandfornitrogen-basedcompounds(ammoniumsaltsforfertilizersandnitricacidforexplosivesmanufacture)withtheoutbreakofWorldWarIin1914.Thisinitiatedprofoundchangeswhichcontinuedduringtheinter-waryears(1918-1939)..Since1940thechemicalindustryhasgrownataremarkablerate,althoughthishasslowedsignificantlyinrecentyears.Thelion’sshareofthisgrowthhasbeenintheorganicchemicalssectorduetothedevelopmentandgrowthofthepetrochemicalsareasince1950.Theexplosivegrowthinpetrochemicalsinthe1960sand1970swaslargelyduetotheenormousincreaseindemandforsyntheticpolymerssuchaspolyethylene,polypropylene,nylon,polyestersandepoxyresins..Thechemicalindustrytodayisaverydiversesectorofmanufacturingindustry,withinwhichitplaysacentralrole.Itmakesthousandsofdifferentchemicalswhichthegeneralpubliconlyusuallyencounterasendorconsumerproducts.Thesesproductsarepurchasedbecausetheyhavetherequiredpropertieswhichmakethemsuitableforsomeparticularapplication,e.g.anon-sickcoatingforpansoraweedkiller.Thuschemicalsareultimatelysoldfortheeffectsthattheyproduce.. 2.DefinitionoftheChemicalIndustryAttheturnofthecenturytherewouldhavebeenlittledifficultyindefiningwhatconstitutedthechemicalindustrysinceonlyaverylimitedrangeofproductswasmanufacturedandthesewereclearlychemicals,e.g.,alkali,sulphuricacid.Atpresent,however,manythousandsofchemicalsareproduced,fromrawmaterialslikecrudeoilthrough(insomecases)manyintermediatestoproductswhichmaybeuseddirectlyasconsumergoods,orreadilyconverted.intothem.Thedifficultlycomesindecidingatwhichpointinthissequencetheparticularoperationceasestobepartofthechemicalindustry’ssphereofactivities,Toconsideraspecificexampletoillustratethisdilemma,emulsionpaintsmaycontainpoly(vinylchloride)/poly(vinylacetate).Clearly,synthesisofvinylchloride(oracetate)anditspolymerizationarechemicalactivities.However,ifformulationandmixingofthepaint,includingthepolymer,.iscarriedoutbyabranchofthemultinationalchemicalcompanywhichmanufacturedtheingredients,isthisstillpartofthechemicalindustryordoesitnowbelonginthedecoratingindustry?Itisthereforeapparentthat,becauseofitsdiversityofoperationsandcloselinksinmanyareaswithotherindustries,thereisnosimpledefinitionofthechemicalindustry.Insteadeachofficialbodywhichcollectsandpublishesstatisticsonmanufacturingindustrywillhaveitsdefinitionastowhichoperationsareclassifiedas“thechemicalindustry”.Itisimportanttobearthisinmindwhencomparingstatisticalinformationwhichisderivedfromseveralsources.. 3.TheNeedforChemicalIndustryThechemicalindustryisconcernedwithconvertingrawmaterials,suchascrudeoil,firstlyintochemicalintermediates,andthenintoatremendousvarietyofotherchemicals.Thesearethenusedtoproduceconsumerproducts,whichmakeourlivesmorecomfortableor,insomecasessuchaspharmaceuticalproducts,helptomaintainourwell-beingorevenlifeitself.Ateachstageoftheseoperationsvalueisaddedtotheproductandprovidedthisaddedvalue.exceedstherawmaterialplusprocessingcoststhenaprofitwillbemadeontheoperation.Itistheaimofchemicalindustrytoachievethis.Itmayseemstrangeintextbooklikethisonetoposethequestion“doweachemicalindustry?”However,tryingtoanswerthisquestionwillprovide(i)anindicationftherangeofthechemicalindustry’sactivities,(ii)itsinfluenceonourlivesineverydayterms,and(iii)howgreatissociety’sneedforachemicalindustry.Ourapproachinansweringthequestionwillbetoconsidertheindustry’scontributiontomeetingandsatisfyingourmajorneeds.Whatarethese?.Clearlyfood(anddrink)andhealthareparamount.Otherwhichweshallconsiderintheirturnareclothingand(briefly)shelter,leisureandtransport.(1)Food.Thechemicalindustrymakesamajorcontributiontofoodproductioninatleastthreeways.Firstly,bymakingavailablelargequantitiesofartificialfertilizerswhichareusedtoreplacetheelements(mainlynitrogen,phosphorusandpotassium)whichareremovedasnutrientsbythegrowingcropsduringmodernintensivefarming.Secondly,bymanufacturingcropprotectionchemical,i.e.,pesticides,whichmarkedlyreducetheproportionofthecropsconsumedbypests..Thirdly,byproducingveterinaryproductswhichprotectlivestockfromdiseaseorcuretheirinfections.(2)Health.Weareallawareofthemajorcontributionwhichthepharmaceuticalsectoroftheindustryhasmadetohelpkeepusallhealthy,e.g.bycuringbacterialinfectionswithantibiotics,andevenextendinglifeitself,e.g.β-blockerstolowerbloodpressure.(3)Clothing.Theimprovementinpropertiesofmodernsyntheticfibersoverthetraditional.clothingmaterials(e.g.cottonandwool)hasbeenquiteremarkable.Thusshirts,dressesandsuitsmadefrompolyesterslikeTeryleneandpolyamideslikeNylonarecrease-resistant,machine-washable,anddrip-dryornon-iron.Theyarealsocheaperthannaturalmaterials.Paralleldevelopmentsinthediscoveryofmodernsyntheticdyesandthetechnologyto“bond”themtothefiberhasresultedinatremendousincreaseinthevarietyofcolorsavailabletothefashiondesigner.Indeedtheynowspanalmosteverycolorandhueofthevisiblespectrum.Indeedifasuitableshadeisnotavailable,structuralmodificationofanexisting.dyetoachievethiscanreadilybecarriedout,providedthereisasatisfactorymarketfortheproduct.Othermajoradvancesinthisspherehavebeenincolor-fastness,i.e.,resistancetothedyebeingwashedoutwhenthegarmentiscleaned.(4)Shelter,leisureandtransport.Intermsofshelterthecontributionofmodernsyntheticpolymershasbeensubstantial.Plasticsaretendingtoreplacetraditionalbuildingmaterialslikewoodbecausetheyarelighter,maintenance-free(I.e.theyareresistanttoweatheringanddonotneedpainting)..Otherpolymers,e.g.urea-formaldehydeandpolyurethanes,areimportantinsulatingmaterialsforreducingheatlossesandhencereducingenergyusage.Plasticsandpolymershavemadeaconsiderableimpactonleisureactivitieswithapplicationsrangingfromall-weatherartificialsurfacesforathletictracks,footballpitchesandtenniscourtstonylonstringsforracquetsanditemslikegolfballsandfootballsmadeentirelyfromsyntheticmaterials.Likewisethechemicalindustry’scontributiontotransportovertheyearshasledtomajor.improvements.Thusdevelopmentofimprovedadditiveslikeanti-oxidantsandviscosityindeximproversforengineoilhasenabledroutineservicingintervalstoincreasefrom3000to6000to12000miles.Researchanddevelopmentworkhasalsoresultedinimprovedlubricatingoilsandgreases,andbetterbrakefluids.Yetagainthecontributionofpolymersandplasticshasbeenverystrikingwiththeproportionofthetotalautomobilederivedfromthesematerials—dashboard,steeringwheel,seatpaddingandcoveringetc.—nowexceeding40%..Soitisquiteapparentevenfromabrieflookatthechemicalindustry’scontributiontomeetingourmajorneedsthatlifeintheworldwouldbeverydifferentwithouttheproductsoftheindustry.Indeedthelevelofacountry’sdevelopmentmaybejudgedbytheproductionlevelandsophisticationofitschemicalindustry.4.ResearchandDevelopment(R&D)inChemicalIndustriesOneofthemainreasonsfortherapidgrowthofthechemicalindustryinthedevelopedworldhasbeenitsgreatcommitmentto,andinvestmentin.researchanddevelopment(R&D).Atypicalfigureis5%ofsalesincome,i.e.thetotalmoneyreceived,whichhastopayforrawmaterials,overheads,staffsalaries,etc.,aswell.Inthepastthistremendousinvestmenthaspaidoffwell,leadingtomanyusefulandvaluableproductsbeingintroducedtothemarket.Exampleincludesyntheticpolymerslikenylonsandpolyesters,anddrugsandpesticides.Althoughthenumberofnewproductsintroducedtothemarkethasdeclinedsignificantlyinrecentyears,andintimesofrecessiontheresearchdepartmentisusuallyoneofthefirsttosuffercutbacks,thecommitmenttoR&Dremainsatveryhighlevel..Thechemicalindustryisaveryhightechnologyindustrywhichtakesfulladvantageofthelatestadvancesinelectronicsandengineering.Computersareverywidelyusedforallsortsofapplications,fromautomaticcontrolofchemicalplants,tomolecularmodelingofstructuresofnewcompounds,tothecontrolofanalyticalinstrumentsinthelaboratory.Individualmanufacturingplantshavecapacitiesrangingfromjustafewtonnesperyearinthefinechemicalsareatotherealgiantsinthefertilizer.andpetrochemicalsectorswhichrangeupto500,000tonnes.Thelatterrequiresenormouscapitalinvestment,sinceasingleplantofthissizecannowcost$250million!This,coupledwiththewidespreaduseofautomaticcontrolequipment,helpstoexplainwhythechemicalindustryiscapital-ratherthanlabor-intensive.Themajorchemicalcompaniesaretrulymultinationalandoperatetheirsalesandmarketingactivitiesinmostofthecountriesoftheworld,andtheyalsohavemanufacturingunitsinanumberofcountries.Thisinternationaloutlook.foroperations,orglobalization,isagrowingtrendwithinthechemicalindustry,withcompaniesexpandingtheiractivitieseitherbyerectingmanufacturingunitsinothercountriesorbytakingovercompanieswhicharealreadyoperatingthere..