石油工程专业英语8

PetroleumScienceinEnglishInstructor:GuoQingChapterEightPetrochemicalIndustryCrudeoilisarawmaterial,likeironore,whichmustbeprocessedbeforeitcanbeused.Infact,thereareseveraldifferentprocessesthroughwhichoilisprocessed,buttogethertheyarecalledrefining〔炼制〕.Therefiningprocessseparatesthedifferentfractionsofmolecules〔分子组分〕inthecrudeoilmixtureintousableproducts.Italsoremovestheimpurities〔杂质〕fromtheoil.Methodsusedinrefiningprocesses.PhysicalseparationprocessesThemaintechniqueis:Distillation-separation〔蒸馏〕accordingtomolecularsize,makinguseofthedifferentinboilingpoint.Othertechniquesare:Absorption〔吸收〕Solventextraction〔溶剂提取〕Crystallization〔结晶〕Adsorption〔吸附〕Methodsusedinrefiningprocesses.TherearethreemaincategoriesofChemicalConversionProcessesReductionofmolecularsize(cracking)(裂化〕---inwhichfueloilcomponentsareconvertedintolighter,distillateproducts〔馏出产品〕suchasgasoil〔粗柴油〕andgasoline.Changeofmolecularstructurewithoutsizechange---e.g.catalyticreforming〔催化重整〕andisomerisation〔异构化〕.Increaseinmolecularsize---e.g.polymerisation〔叠合〕andalkylation〔烷基化〕Distillation:Thefirststepofrefiningiscalleddistillation.Thetheoryofdistillationisveryeasy.Mostliquidsboil〔沸腾〕whentheyreachacertaintemperature.Whencrudeoilboils,itsendsout〔释放出〕vapor〔蒸汽〕andcondenses〔冷凝〕.Allthedifferenthydrocarbons〔烃〕incrudeoilareboilingatdifferenttemperatures,andtheirvaporsallmakeseparate〔不同的〕liquids.So,inordertoseparate〔别离〕thehydrocarbons,thescientistsdistill〔蒸馏〕thecrude.Whenthedifferenthydrocarbonsboilatdifferenttemperatures,theirvaporscondenseintoitsfractions〔馏分〕andformsdifferentliquids.Theoilisdistilled〔蒸馏〕inaverylargesteeltower〔钢塔〕,thetechnicalname〔技术名称〕ofwhichisthe“fractionatingtower〞〔分馏塔〕.Thetoweristhirtytofiftymeterstallanditsdiameter〔直径〕isonetothreemeters.Itisdividedinto“chambers〞〔室〕,eachofwhichcontainsalayeroftrays〔塔盘〕.Thereareholesinthetrays.Theoilisheatedtoahightemperatureincoilofpipe〔盘管〕thatpassoverafurnace〔热炉〕.Thentheoilispipedintoafractionatingtowerandallbuttheheaviestmolecules〔重分子〕changeintoavapororagas.Thevaporsgothroughtheseholesandcondense〔冷凝〕onthetrays,thatistheyturnintoliquidsagain---ataparticulartemperatureataparticularlevelinthetower.Thechambersareatdifferentheights,andthetemperatureateachheightisdifferent.Thetemperatureinsidethetowerishighestatthebottom,anditislowestatthetop.Soeachlayeroftraysiscoolerthanthelayerbelowit.Therearenotenoughchambersofdifferenttemperaturesinonetower,sotwoorthreetowersareneeded.Cracking〔裂化〕:Sinceonlyabout20%ofcrudeoilcanberefinedintogasolinebydistillation,theoilindustrychemistshadtofindaprocessbywhichmoregasolinecouldbecreatedfromtheotherpetroleumproductsthatwerenotinsuchgreatdemand.Theprocessthattheydevisediscalledcracking.Creakingmeansbreakingdowntheheavymoleculesofsuchpetroleumproductsaskeroseneorlubricatingoilintothelightermoleculesofgasoline.Therearetwobasickindsofcracking,thermalcracking〔热裂化〕andcatalyticcracking〔催化裂化〕.Therefiningprocess(炼制过程〕canbedividedintototheprimaryrefiningprocessandthesecondaryrefiningprocess.Theprimaryrefiningprocess〔粗炼工序〕isthedistillation〔蒸馏〕ofthefeedstock〔进料〕intoitsbasicfractions〔根本组分〕,andthenre-distillationofthese,inseparatetowers,intohighlyconcentratedintermediates〔高浓度的半成品〕,Inasimplerefinery〔简易炼厂〕,thesplit〔馏分〕wouldprobablyconsistofthesesixbasiccuts〔根本组分〕:petroleumgas〔石油气〕(refinerygasandLPG炼厂气和液化石油气),gasoline〔汽油〕,naphtha〔石脑油〕,kerosene〔煤油〕,gasoil〔柴油〕andresidue〔渣油〕.Thesecondaryrefiningprocess〔精练工序〕aredesigned(1)toremoveanyimpurities〔杂质〕fromthedistilledfractions〔已蒸馏的组分〕,and(2)toconvert〔转换〕someofthedistilledhydrocarbonsintodifferentmolecularforms〔分子结构〕.Conversionprocessescanproducehydrocarbonsthatdonotexistinreservoircrude.Refineryproducts〔炼制产品〕Thefuelsrefinedfromcrudeoilcanbedividedintotwogeneraltypes:(1)fuelsthatareexploded〔爆炸〕,whenvaporizedwithair〔与空气雾化后〕,toprovideprimarymovingpower〔原动力〕,includingtheaviationfuels〔航空油〕,industrialanddomesticgases(LPG)〔工业及民用液化石油气〕,motorspirits〔车用汽油〕,dieseloil〔柴油〕andrefinerygases〔炼厂气〕.And(2)thosefuelsthatareeitherburneddirectlyforheatandlightorareconvertedinto〔转化成〕secondaryenergysources〔二次能源〕suchaselectricity,includingtheordinarykerosene〔普通煤油〕andthevariousgradesoffueloils〔各种级别的燃料油〕.ConventionalOilRefineryProducts〔常规石油炼制产品〕MotorSpirit〔发动机动力油〕Kerosene〔煤油〕DieselOil〔柴油〕Lubricatingoils〔润滑油〕Waxes〔蜡〕Bitumen〔沥青〕ProtectingtheenvironmentWhenconsideringarefinery‘sperformanceinprotectingtheenvironment,localconditions〔当地条件〕,e,g,distancefromresidentialarea〔离居民区距离〕,meteorology〔气象状况〕,plantage〔装置寿命〕andcapacity〔加工能力〕,typeofprocessingunits〔工艺装置类型〕,etc,areofoverridingimportance〔首屈一指的重要性〕.Cost-effectivepollutioncontrol〔经济有效的污染控制〕beginsbeforeaplantisbuilt.Problemscanbeminimized〔减少到最低程度〕orevensolvedbeforetheyariseiftheplantiswelldesigned,properlyoperatedandwellmaintained.Potentialimpacts〔潜在的影响〕ontheenvironmentshouldbeidentified〔发现〕and,ifneedbe,attendedtointheearliestpossiblestage〔尽早予以注意〕ofdevelopmentofanewproject.Keywordspetrochemical〔石油化学的〕refining〔炼制〕fractionsofmolecules〔分子组分〕impurities〔杂质〕distillation-separation〔蒸馏〕absorption〔吸收〕solventextraction〔溶剂提取〕crystallization〔结晶〕adsorption〔吸附〕vapor〔蒸汽〕fractionatingtower〔分馏塔〕alayeroftrays〔塔盘〕coilofpipe〔盘管〕chambers〞〔室〕alayeroftrays〔塔盘〕coilofpipe〔盘管〕afurnace〔热炉〕condense〔冷凝〕cracking〔裂化〕thermalcracking〔热裂化〕cata