广东工业大学刘敬勇Behavior of lead compounds during municipal solid waste incineration

Combustion

Available online at doc.xuehai.net

ProceedingsCombustionInstitute

doc.xuehai.net

ofthe

ProceedingsoftheCombustionInstitute32(2009)

2685–2691

Behaviorofleadcompoundsduringmunicipal

solidwasteincineration

HongYaoa,IchiroNaruseb,*

a

StateKeyLaboratoryofCoalCombustion,HuazhongUniversityofScienceandTechnology,Wuhan430074,China

b

DepartmentofMechanicalScience&Engineering,NagoyaUniversity,Nagoya464-8603,Japan

Abstract

Inordertodepresstheconcentrationofheavymetalsinthebottomashintheincinerator,thebehaviorofleadcompoundsduringsimulatedmunicipalsolidwaste(MSW)incinerationwasinvestigated,usinganelectricallyheateddroptubefurnace.Intheexperiments,specialtypeof shfoodwaschosenasthesim-ulatedwaste,whichwasburnedaloneandalsoblendedwithpureleadcompounds,suchasPbO,PbCl2andPbSO4.ForthesimulatedwasteblendingwithPbO,testwithadditionofHClgasintothecombustionairwasalsoconducted.Thefurnacetemperatureandcombustionairstoichiometrywerevariedfrom873to1273Kand0.5to1.2,respectively.Ashparticleswereisokineticallysampledatthefurnaceexitbyawater-cooledsamplingprobe,atthetipofwhichN2gaswasinjectedtoquenchthecombustiongasandparticles.Thoseparticleswerethenseparatedbyalowpressureimpactorwith13stages.Theresultsshowthatthetendencyoftheleadenrichmentinthe neparticleslessthan1lmdependsonthemeltingtemperaturesoftheleadcompounds.Ofthethreeleadcompounds,PbCl2isenrichedthemostintothe neparticles,andPbSO4isthemostdi cultatthelow-temperaturesexamined.However,whenHClgaswasmixedwiththecombustionair,morePbisenrichedin neparticlesevenatlowtemperatures.Thelowcombustionairstoichiometryenhancesformationofalargeamountof neparticlescontaininghighconcentrationsoflead.ThemechanismofPbenrichmentinthecoarseparticlesiscontrolledbythesurfacereactionofvaporofPbcompoundswiththeashparticles.Two-stageincineratorincludinga rst-stagegasi cationzonewithhighertemperatureandlowerstoichiometricairratio,ispreferabletoshiftthePbenrichmentfrombottomashinto yashduringwasteincineration.

Ó2009TheCombustionInstitute.PublishedbyElsevierInc.Allrightsreserved.

Keywords:Bottomash;Leadcompounds;Municipalsolidwaste;Incineration

1.Introduction

Whilethevolumeofmunicipalsolidwaste(MSW)graduallyincreases,itishardto ndnew naldisposalsites.ThermalrecycleoftheMSWisrecognizedtobeoneofthesuitablewaysto

*

Correspondingauthor.Fax:+81527895123.

E-mailaddress:naruse@mech.nagoya-u.ac.jp(I.Naruse).

decreaseitsvolume[1].Forexample,morethan70%oftheMSWinJapanisincineratedsincethereisnospaceforland ll.MSWcontainshighercon-centrationsofheavymetalsthanfossilfuels,there-fore,thecontrolofemissionsoftheseheavymetalsisanimportantissuewhentheMSWisincineratedorco- redwithotherfuels[2–6].

InMSWincinerators,about90%oftheashleavesasthebottomashcontainingrelativelycoarserparticles.Inrecenttime,thebottomash

1540-7489/$-seefrontmatterÓ2009TheCombustionInstitute.PublishedbyElsevierInc.Allrightsreserved.doi:10.1016/j.proci.2008.07.026

第1页下一页