Thisarticlewasdownloadedby:XianJiaotongUniversityOn:13March2013,At:00:54Publisher:Taylor&FrancisInformaLtdRegisteredinEnglandandWalesRegisteredNumber:1072954Registeredoffice:MortimerHouse,37-41MortimerStreet,LondonW1T3JH,UKInternationalJournalofGreenEnergyPublicationdetails,includinginstructionsforauthorsandsubscriptioninformation:/loi/ljge20DehydrationofWasteEdibleOilbyHydrocyclonesZ.Baia,H.Wanga&S.TuaaKeyLabofSafetyScienceofPressurizedSystem,MinistryofEducationSchoolofMechanicalandPowerEngineering,EastChinaUniversityofScienceandTechnology,Shanghai,ChinaVersionofrecordfirstpublished:07Apr2009.Tocitethisarticle:Z.Bai,H.Wang&S.Tu(2009):DehydrationofWasteEdibleOilbyHydrocyclones,InternationalJournalofGreenEnergy,6:2,184-191Tolinktothisarticle:/10.1080/15435070902785001PLEASESCROLLDOWNFORARTICLEFulltermsandconditionsofuse:/page/terms-and-conditionsThisarticlemaybeusedforresearch,teaching,andprivatestudypurposes.Anysubstantialorsystematicreproduction,redistribution,reselling,loan,sub-licensing,systematicsupply,ordistributioninanyformtoanyoneisexpresslyforbidden.Thepublisherdoesnotgiveanywarrantyexpressorimpliedormakeanyrepresentationthatthecontentswillbecompleteoraccurateoruptodate.Theaccuracyofanyinstructions,formulae,anddrugdosesshouldbeindependentlyverifiedwithprimarysources.Thepublishershallnotbeliableforanyloss,actions,claims,proceedings,demand,orcostsordamageswhatsoeverorhowsoevercausedarisingdirectlyorindirectlyinconnectionwithorarisingoutoftheuseofthismaterial.DEHYDRATIONOFWASTEEDIBLEOILBYHYDROCYCLONESZ.Bai,H.Wang,andS.TuKeyLabofSafetyScienceofPressurizedSystem,MinistryofEducationSchoolofMechanicalandPowerEngineering,EastChinaUniversityofScienceandTechnology,Shanghai,ChinaWasteedibleoilisthehighqualitymaterialfromwhichbiodieselfuelscanbemade.Thewaterdropletsinwastededibleoilaffecttheprocessingcoursesandtheproductquality.Anewprocessofwasteedibleoildehydrationbasedonhydrocyclonetechnologyhasbeendesigned.Preliminaryindustrialexperimentshavebeencarriedouttoprovethefeasibilityofdehydrationusingahydrocyclone.Theeffectsofseveraldimensionlessunits,suchasReynoldsnumber,Eulernumber,andpressuredropratio,werestudied.AnincreaseinReynoldsnumberwilldecreasethepressuredropratio.WithanincreaseintheReynoldsnumber,theEulernumberincreasesgradually.UndertheconditionthattheReynoldsnumberofinletisrangingfrom5,000to5,800,thewaterconcentrationcandecreasefrom0.53.0vol.%tolessthan0.30vol.%.Keywords:Hydrocycloneseparation；Dehydration；WasteedibleoilINTRODUCTIONTheamountofwasteedibleoilcollectedinalltheEuropeanUnionwasestimatedtobeabout400,000tons.However,itispredictedthatthecollectionofvegetableoilwillriseandmayreachamountsbetween700,000and1,000,000tons,and90%ofthoseedibleoilswillbedumpedasrefusewithoutcollection(Ayhan,2007；Pintoetal.2005).Itisunreasonablefromtheviewpointofresourcesavingthatmostofthewasteedibleoilisdumpedwithoutbeingutilized(withtheexceptionthatasmallpercentageofwasteedibleoilisrecycledasarawmaterialofsoap).Moreover,whenthewasteedibleoilisincineratedtogetherwithcombustiblerefuse,alargeamountofsuspendedparticulatematter,suchasSOx,NOx,CO2,andCOturningtoairpollutantsareproduced,anditisreportedthatdeadlypoisonousdioxinmaybeproduced.Ontheotherhand,whenthewasteedibleoilisburiedtogetherwithnoncombustiblerefuse,soilpollutionoccurs.Apartofthewasteedibleoildumpedfromrestaurants,foodplantsandhomesisactuallydischargedintoriversandlakesandisoneofthemajorcausesofwaterpollution.Inthissense,transesterificationofwasteedibleoilstoproducebiodieselcoulddecreasethewastedisposalproblem.Thewasteedibleoilsservingasrawmaterialincludewrapeseedoil,sesameoil,soybeanoil,maizeoil,sunfloweroil,palmoil,palmkerneloil,coconutoil,InternationalJournalofGreenEnergy,6:184191,2009CopyrightC211Taylor&FrancisGroup,LLCISSN:1543-5075print/1543-5083onlineDOI:10.1080/15435070902785001AddresscorrespondencetoH.Wang,SchoolofMechanicalandPowerEngineering,EastChinaUniversityofScienceandTechnology,130MeilongRoad,Shanghai200237,PRChina.E-mail:184DownloadedbyXianJiaotongUniversityat00:5413March2013cornoil,saffloweroil,etc.,andeitheroneofthemoramixtureofthementionedoilsisemployedasarawmaterial.Thereisnoparticularrequirementregardingthequalityofoil,butitisgenerallypreferablethatthebleoilhaslowcontentofwaterandsolidcomponent.Thesedimentationmethodisatypicalmethodofdewateringwasteedibleoil.Butlowefficiencyandlargesizearegreatdisadvantagestothesedimentationmethod.Manyresearcheffortshavebeentakentostudythedewateringofwasteedibleoilandgainedconsiderableprogress,includingthecentrifugemethod(Wangetal.1997),filtrationmethod(Guuetal.1997；Tanaka,2004；Tirmizietal.1996),magnetichandlingmethod(Freemanetal.1994；Shenetal.,1990),anddirectcurrenthydrocyclonemethod(Pratarnetal.2005；Pratarnetal.2006).Butthosetechniqueswerelessusedinindustrialproductionbecauseofthecomplexityoftheequipmentandlowreliability.Thenanewprocessofwasteedibleoildehydrationthatisbasedonhydrocyclonetechnologywasdesigned.Preliminaryexperimentshavebeencarriedouttoprovethefeasibilityofdehydrationusinghydrocyclone.Wedemonstrateherethatwaterwasbeingremovedsuccessfullyinwasteedibleoilthroughhydrocyclones.FUNDAMENTALSOFDEHYDRATIONWITHHYDROCYCLONEPrincipleofHydrocycloneSeparationAhydrocycloneisadevicethatcausesthecentrifugalseparationofmaterialscontainedintheliquidfedtoit(Baietal.2006；Cullivan,etal.2003；Firth2003；Habibianetal.2008).Thesematerialsarenormallyintheformofsolidparticlesbutmayalsobegasbubbles,oil,orothers.Thefeedsareseparatedbytheinducedcentrifugalforceinsidethehydrocyclonebodyandmainlyaccordingtotheirdensity,size,andshape.Unlikeothercentrifugalmachines,hydrocycloneshavenomovingparts.Thesepara-tiondrivingforcecomesfromthetransformationofthestaticenergyofthefluid(fluidpressure)intodynamicenergy(fluidvelocity).Ahydrocyclonebodyconsistsoftwoparts:acylindricalpartandaconicalpart.Designdependsonboththenatureoftheseparationandthequalityofeffluentdesired.Theapplicationsofhydrocyclonesareprincipallytheseparationofsolidsuspendedmatterandtheclarificationofliquidphases.Figure1showstheoperationofahydrocyclonedesignedforliquid-liquidseparation.Thefluidisinjectedtangentiallyatthetopofthehydrocycloneandcausecentrifugalforcestoaccelerateparticlestowardthewalls.Asthefluidpassesthroughthehydrocycloneinaspiralfashion,largeordenseparticlesareforcedagainstthewallandmigratedownwardstotheunderflow.Fineorlowdensityparticlesaresweptintoasecondinnerspiralthatmovesupwardtotheoverflow.FlowSplitandPressureDropRatioFlowsplitofthehydrocycloneisdefinedtheratioofthevolumeflowoftheunder-flowtofeed,i.e.,RQu=Qi100%(1)whereRistheflowsplit,andQuandQiareindividuallythevolumeflowoftheunderflowandfeed.Undernormaloperatingconditions,therearetwodistinctpressuredropsacrossthehydrocycloneseparator:DEHYDRATIONOFWASTEEDIBLEOILBYHYDROCYCLONES185Do