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2732Vol.27No.32Nov.2007200711ProceedingsoftheCSEE©2007Chin.Soc.forElec.Eng.0258-8013(2007)32-0018-06TK16X513A470⋅20(100084)ExperimentalStudyontheEmissionCharacteristicsofLeadDuringCombustionZHANGXiao-feng,YAOQiang,SONGQiang,LiShui-qing(KeyLaboratoryofThermalScienceandPowerEngineeringofMinistryofEducation,TsinghuaUniversity,HaidianDistrict,Beijing100084,China)ABSTRACT:Theemissioncharacteristicsoflead,suchasaerodynamicparticlesizedistribution(PSD),chemicalcompositionandmorphology,wereinvestigatedexperimentallyusingalaboratoryone-dimensionfurnace.Alsotheformationmechanismsandpathwaysofleadparticleswereanalyzedanddiscussed.Aqueoussolutionofleadacetatewasintroducedintofurnacethroughaliquefiedpetroleumgasflameviaairatomization.PSDswereobtainedbyisokineticsamplingusingThermoAndersenimpactoraccordingtostandardmethodofU.S.EPA.Theresultsshowthat:About2/3ofleadparticleshavetheaerodynamicdiameterlessthan480nm,massconcentrationdistributionisasinglemodalPSDwithpeakbetween0.2~0.6µm,andthechemicalcompositionofparticlesisPbO;Inthepresenceofchlorine,thePSDofleadparticlesisnotobviouslychange,thechemicalcomponentofparticlesbecomestoPbCl2,itindicatesthatchlorinehashighlyreactivitywithlead.Itisfoundfrommicrographsofleadparticlesthatthereexistsomebasicparticles,havingabout50nmsizeandclearboundary,whicharebasicunitscomposingonewholeparticlegroup.Thesebasicparticleslinktogetherandbecomeachain.Thechainscrosswitheachotherandbecomeanetwork.Ultimately,aparticlegrouphavingseveralhundredsnanometersizecomeintobeing,whichisthemainconfigurationofleadparticlereleased.Theformationpathwaysofleadparticleswerespecifiedaccordingtotheobservationofmicrographs.Thebasicparticlesmaybeanimportantpointduringtheparticleformationprocess.KEYWORDS:lead;emissioncharacteristics;particulatematters;particlesizedistribution;particleformation:(2002CB211606)ProjectSubsidizedbytheSpecialFundsforMajorStateBasicResearchProjectsofChina(2002CB211606).EPAAndersen2/3480nm0.2~0.6µmPbOPbCl250nm:0[1-3]3[4-5]()()()——[1][6]32192()[7][8-11]Mulholland[8]33Owens[10]Scotto[9]Davis[11]800~1400K[12-18]Andersen11.1153.4m150mm700mm(LPG)MADURGA-40(DCS)Ι1Fig.1Theschematicoflaboratoryscaleone-dimensionfurnacesystem1.26h0.8m3/h()100Pa3.5%10mL/min0.017mol/h0.116mol/h201.02.0L/m80010001200140016002Fig.2Temperatureprofileofone-dimensionfurnace1.3(EPA)Method17[19]ThermoAndersenATS88d5012.637.885.323.652.371.180.720.48µmThermoAndersen1202719.8L/min403K1.4Andersen0.1mg(FESEM)(TEM)X(XRD)22.1Andersen2/3480nm8dM/dlogDP-DPdM/dlogDPPPd/dlog(log)MMDD∆=∆(1)DPµm∆Mmg/m3()∆(logDP)30.2~0.6µmMulholland[8]Pb(NO3)2MulhollandScotto[9]Owens[10]Davis[11]Davis403KDavis800~1400K2.230.3~0.6µmScotto[9]110Dp/µm01020304050PbPb+Cl3Fig.3Massconcentrationdistributions2.3[20-21]PbO2Pb3O4PbCl4Owens[10]X(1273K)2PbCO3·Pb(OH)2CO2(773K)PbOAndersenX42XRD4(a)XRD2θ=29.0°32.5°37.6°PbO4(b)XRD2θ=23.0°25.1°32.4°PbCl21.2100µL/L32211030502θ/(°)(a)Pb(b)Pb−ClPbOPbCl24XRDFig.4XRDspectraofleadparticlesPbCl22.45(FESEM)10µm50005(a)(b)68FESEM0.72d1.18µmd0.48µm5(a)1~2µm1~2µm5(b)0.5µm5(c)(d)68FESEM5(c)5(a)PbCl25.98g/cm3PbO8.00g/cm3Andersen5(d)(a)Pb6(b)Pb8(c)Pb+Cl6(d)Pb+Cl85FESEMFig.5FESEMimagesofleadparticles0.5µm8(TEM)6(a)(b)TEM50nm650nm6(a)50nm6(b)6(a)(a)Pb(b)Pb+Cl6TEMFig.6TEMimagesofleadparticles2.5[1,3]BiswasPbOPbCl2PbOPbCl222271µm31Andersen8480nmdM/dlogDP-DP0.2~0.6µm2Andersen8dM/dlogDPDP0.3~0.6µm3XRDPbOPbCl24TEMFESEM50nm1µm5[1]LinakWPWendtJOLToxicmetalemissionfromincinerationmechanismsandcontrol[J]ProgressinEnergyandCombustionScience199319(2)145-185[2][J]200121(10)33-38XuMinghouZhengChuguangFengRongetalOverviewoftraceelementsresearchincoalcombustionprocess[J]ProceedingsoftheCSEE200121(10)33-38(inChinese)[3]BiswasPWuCYControloftoxicmetalemissionsfromcombustorsusingsorbentsareview[J]JournaloftheAir&WasteManagementAssociation199848(2)113-127[4]ClarkeLBSlossLLTraceelements-emissionsfromcoalcombustionandgasification[R]IEACR/49LondonIEACoalResearch1992[5]RiaeqRGHansellDWSeekerWRPredictionofmetalsemissionsandpartitioningincoal-firedcombustionsystems[J]FuelProcessingTechnology199439(1-3)219-236[6]PirkleJLBrodyDJGunterEWetalThedeclineinbloodleadlevelsintheunitedstates[J]JAMA1994272(7)284-291[7]Ratafia-BrownJAOverviewoftraceelementspartitioninginflamesandfurnacesofutilitycoal-firedboilers[J]FuelProcessingTechnology199439(1-3)139-157[8]MulhollandJASarofimAFMechanismsofinorganicparticleformationduringsuspensionheatingofsimulatedaqueouswastes[J]EnvironmentalScienceandTechnology199125(2)268-274[9]ScottoMVPetersonTWWendtJOLHazardouswasteincinerationthein-situcaptureofleadbysorbentsinalaboratorydown-flowcombustor[C]Proceedingsof24thSymposiumonCombustionPittsburgh1992[10]OwensTMBiswasPReactionsbetweenvaporphaseleadcompoundsandinsitugeneratedsilicaparticlesatvariouslead-siliconfeedratiosapplicationstotoxicmetalcaptureincombustors[J]JournaloftheAir&WasteManagementAssociation199646(6)530-538[11]DavisSBThomasKGaleTKetalMulti-componentcoagulationandcondensationoftoxicmetalsincombustors[C]Proceedingsof27thSymposiumonCombustionPittsburgh19981785-1792[12][J]1