超临界水氧化技术处理含油污泥

JournalofHazardousMaterials165(2009)511–517ContentslistsavailableatScienceDirectJournalofHazardousMaterialsjournalhomepage:∗,FuyiCuia,GuolinJingb,ShengliXuc,WeijingHuob,ShuzhiLiubaSchoolofMunicipal&EnvironmentalEngineering,HarbinInstituteofTechnology,Harbin150090,PRChinabSchoolofChemistryandChemicalEngineering,DaqingPetroleumInstitute,Daqing163318,PRChinacHuayiCorporationofPioneeringGroup,DaqingPetroleumAdministrationBureau,Daqing163000,PRChinaarticleinfoArticlehistory:Received10July2008Receivedinrevisedform6October2008Accepted6October2008Availableonline14October2008Keywords:OilysludgeSupercriticalwateroxidationKineticsabstractTheoxidationofoilysludgeinsupercriticalwaterisperformedinabatchreactoratreactiontemperaturesbetween663and723K,thereactiontimesbetween1and10minandpressurebetween23and27MPa.Effectofreactionparameterssuchasreactiontime,temperature,pressure,O2excessandinitialCODonoxidationofoilysludgeisinvestigated.Theresultsindicatethatchemicaloxygendemand(COD)removalrateof92%canbereachedin10min.CODremovalrateincreasesasthereactiontime,temperatureandinitialCODincrease.PressureandO2excesshavenoremarkableaffectonreaction.BytakingintoaccountthedependenceofreactionrateonCODconcentration,aglobalpower-lawrateexpressionwasregressedfromexperimentaldata.Theresultingpre-exponentialfactorwas8.99×1014(molL−1)−0.405s−1;theacti-vationenergywas213.13±1.33kJ/mol;andthereactionorderforoilysludge(basedonCOD)is1.405.Itwasconcludedthatsupercriticalwateroxidation(SCWO)isarapidlyemergingoilysludgeprocessingtechnology.©2008ElsevierB.V.Allrightsreserved.1.IntroductionOilysludgeisoneofthelargestcategoriesofwastesgener-atedbyoilindustrypetroleumproductionandpetroleumrefineryplant.Themainsourceofoilysludgeistankbottoms.OthersourcesincludeAPIseparatorbottom,operatingslop,oilspills,operatingresiduesandothermiscellaneoussources[1,2].Thecompositionoftheoilysludgeiscomplexanddependsonthetypeofpetroleumanditssource.Generally,itcontainswasteoil5–60wt%,water30–90wt%andmineralparticles5–40wt%[3].Thiswasteoilisamixtureofcompounds,mainlyhydrocarbons.Advanceanaly-sesonwasteoilshowedthatitiscomposedof40–52wt%alkane,28–31wt%aromatics,7–22.4wt%resins,and8–10wt%asphaltenes[4,5].Manyofthesecomponentsaretoxic,mutagenicandcarcino-genic[6–8].Therefore,theirreleasetotheenvironmentisstrictlycontrolledandtheyareclassifiedaspriorityenvironmentalpollu-tantsbytheUSEnvironmentalProtectionAgency,duetoposingaseriousthreattotheenvironment[9].Thetreatmentanddisposalofoilysludgerepresentsmajorchallengesforpetroleumindustries.Theoilysludgeconsumesahighportionofbudgetofoilproductionplantandrefiner.Severalconventionaltechnologies,suchaslandfill,biologicaltreatment,∗Correspondingauthorat:SchoolofMunicipal&EnvironmentalEngineering,HarbinInstituteofTechnology,Harbin150090,PRChina.Tel.:[phone];fax:[phone].E-mailaddress:[e-mail](B.Cui).incinerationandsoon,forthetreatmentanddisposalofoilysludgehavebeenimplemented.Varioustreatmentoptionsarecomparedintermsoftheireffectiveness,easeofoperation,andcost.Ofthetechnologiesmentionedabove,landfillisacheapandstraightfor-wardtreatmentmethodforoilysludge.However,withoutvolumereductionandappropriatetreatmentbeforedisposal,oilysludgewillreducetheservice-lifeoflandfillsitesandmayresultinanodorproblemandcreatetheriskofcontamination,particularlyofgroundwater,thuscausingadversehealtheffects.Biologicaltreat-mentoforganicpollutantsisapromising,reliable,simpleandcheaptechnologyoverchemicalandphysicalprocesses[10–12].How-ever,itisreportedasbeingverydifficultornon-practicalbecauseittakesarelativelylongtimetotreatandtheremovalrateislow[13–15].Incinerationisavaluablemeansofwastedisposalwiththeadvantageofbeinghighlyeffectiveinreducingthevolumeofwaste.Unfortunately,incineratorsgeneratelargevolumesofoff-gasescontainingpolycyclicaromatichydrocarbons.Furthermore,theauxiliaryfuelmustbeaddedtotheincineratortokeeptheincinerationtemperatureconstant[16].Asmentionedabove,notechnologycurrentlyhasreachedasatisfactorysolutionfromtheenvironmentalandhighlyeffectivepointofview.Consequently,thereisaneedforenvironmentallybenigntechnologiescapabletoeffectivelyneutralizetheoilysludgeandreduceitsadverseimpactsontheenvironment.Supercriticalwateroxidation(SCWO)hasbeendrawingmuchattentionduetoitscapabilitytoeffectivelydestroyalargevari-etyofhigh-riskwastesresultingfromcomplexindustrialchemicalandregardedasoneofthepromisingtechnologiesforalternative0304-3894/$–seefrontmatter©2008ElsevierB.V.Allrightsreserved.doi:10.1016/j.jhazmat.2008.10.008512B.Cuietal./JournalofHazardousMaterials165(2009)511–517Table1StudiesonSCWOofpetroleumhydrocarbonsandoilywastesorsewagefoundinliterature.ReactantT(K)p(MPa)Reactiontime(s)OxidantReactortypeResultsReferencesBenzene750–86013.9–27.83–7O2–Benzeneconversionisabove95%[23]Pyrene473–6539.5–22.50–7200H2O2BatchRapiddissolutionandoxidationofpyrenestartedfrom573K[17]Biphenyl,fluorene,hexadecane,eicosane573–65310.5–22.50–3600H2O2BatchConversion