分级燃烧中固体吸附剂对痕量金属排放的影响

1,1,1,1,1,2(1.,430074,E2mail:[e-mail];2.,100101):.1120,20%,1100.,,(CuNi).,.,,,Co,Cr,Ni,;Be,;CaOCu.,Be,Cr,Ni,;CoCu,.:;;;:X70112:A:025023301(2001)0620520034:(G1999022212):(1974),,,.:2001203208EffectsofAirStagingwithAbsorbentsonTraceMetalduringCoalCom2bustionChengJunfeng1,HanJun1,LiuYinghui1,ZengHancai1,XuMinghou1,LuoKunli2(1.NationalLabofCoalCombustion,HuazhongUniv.ofSci.&Tech.,Wuhan430074,ChinaE2mail:[e-mail];2.InsitituteofGeographicalScienceandNaturalResource,ChineseAcademyofSciences,Beijing100101,China)Abstract:Stagedcombustionwascarriedoutonlaboratory2scalepulverizedcoalcombustionwithdifferentabsorbents.Theexperimentindicatedstagedcombustionincreasedemissionofsubmicronparticles,whichwentagainstthecontroloftraceelements,especiallyforthoseofhighvolatileelements,suchasCu,Ni.Thethermodynamicscalculationalsoindicatethetransformationoftracemetalwasdifferentwithdifferentatmosphere,suboxidizedandreducedspeciesweremoreeasilyformedunderreducedcondition.Inbothconditions,absorbentsshowacertainabsorptiveabilitytotracemetal,anddifferentabsorbenthaddifferentability.Forunstagedcombustion,kaolinitewasthebestforCo,CrandNi;dolomiteforBe,andCaOforCu.Butforunderstagedcondition,HZ2dolomitewasthebestforBe,CrandNi;KaoliniteforCoandCu.Keywords:traceelement;airstagedcombustion;absorbents;coal2fired.[1],,,,,.(99%),,,.,,.226200111ENVIRONMENTALSCIENCEVol.22,No.6Nov.,2001©1995-2004TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved..,,,[23].,,,[47].NOx,[8],.,,SO2NOx,.,.,.1,1.,315m,1193m,6,01175m.,6kW..,.,3.,O2,SO2NOxMAESTER2000.,1120,20%,.115kg/h.:1100,900.1121314151617181911011111211311411Fig.1Theschematicdiagramofoneorderpulverizedcoalfurnace(Wad,0146%;Aad,32122%;Vad,22118%;FCad,45114%),.CaO,,,1.3%.,HNO32HF2HClO4,ICP2AESBeCuCoNiCr.,2.22111Table1Thecompositionandstructuralcharacteristicofabsorbents/%CaO60162CaO29112CaO39120SiO233168MgO1188MgO11168Al2O334161Fe2O31136BET/m2g-16150221192113157352018648/mlg-101004476010010580100281301022058/nm2175335212020931148384127871536©1995-2004TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved.2/gg-1Table2TracemetalconcentrationofcoalandflyashCaOBe312471277169812981367101714761247172Co71241519918114161391811314170161551315715135Cr12127991801041021011298916576149841678718389167Cu20136148195146104144160143142131183135194127111129167Ni2017811619013315611619311619372111851298315889157(2),,,.,,,,.,,,,,,,,,.,2.,.Linak[9],,,.,,,.,Cu2,BeNiCr32,Co3,,CuNiCrCoBe,(2).2Fig.2Effectofstagedandunstagedonsorption212,FACTCrNi,3,4,,,.6322©1995-2004TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved.Cr,1400KCrO3(g),CrO2(g),CrO(g),,1800KCr2O3(s),1800K,Cr2O3(s)CrO2(g)CrO(g),Cr2O3(s),(1).Cr2(SO4)3(s)\Cr2O3(s)\CrO2(g)+CrO3(g)CrO3(g)\CrO2(g)+CrO(g)(1)NiSO46H2O(s),(2),3CrFig.3Crspeciesdistributionwithtemperatureunderdifferentatmosphere4NiFig.4Nispeciesdistributionwithtemperatureunderdifferentatmosphere,(3).,.NiSO4(s)\NiO(s)\NiO(g)+Ni(g)(2)NiS2(s)\NiS0184(s)\Ni3S2(s)Ni3S2(s)\Ni(s)\Ni(g)+NiO(g)(3),[10],,.,,.,,,,.213,.,(Knudenson),,.SiO2,Al2O3,MgO,.,SiO2,Al2O3PbCdCrNiCo,736©1995-2004TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved.,.2,,Co,Cr,Ni,,18114,104102,133156g/g;Be,,8136g/g;CaOCu,148195g/g.,Be,Cr,Ni,,8136,89167,89157g/g;CoCu,,16155,135194g/g.5,.,,,,,,,,[11].,,,,,.,,;,2.CaO,,,,,.3(1),,,,.(2),,,,.(3),,.:1,,.,,,.,1992,20(2):206211.2BiswasP,WuCY.Controloftoxicmetalemissionsfromcombustorusingsorbents:Areview.JournaloftheAir&WasteManagementAssociation,1998,48:113127.3GullettBK,RaghunathanK.Reductionofcoal2basedmetalemissionsbyfurnacesorbentinjection.Energy&Fuels,1994,8(5):10681076.4MohitUberol,FarhangShadman.High2temperaturere2movalofcadmiumcompoundsusingsolidsorbents.Environ.Sci.Technol.,1991,25:12851289.5UberoiM,ShadmanF.Sorbentsforremovalofleadcom2poundsfromhotfluegased.AIChE.Journal,1990,36:307309.6AGhosh2Dastidar,SMahulietal.Seleniumcaptureusingsorbentpowders:mechanismofsorptionbyhydratedlime.EnvironSci.Technol,1996,30:447452.7WendJOL,LinakWP.Environmentalcontroloftoxicmet2alairemissionsfromthecombustionofcoalandwastes.Pro2cedingsofsymposiumonenergyengineeringinthe21stcen2tury(SEE2000),913January,HongKong:16861690.8HartmutSpliethoff,UlrichGreul,HelmutRdigeretal.BasiceffectsonNOxemissionsinairstagingandreburningatabench2scaletestfacility.Fule,1996,75:560565.9LinakWP,PetersonTW.Mechanismsgoverningthecompositionandsizedistributionofashaerosolinalaborato2rypulverizedcoalcombustion.Twenty2firstsymposium(in2ternational)oncombustion.thecombustioninstitute,1986.39941010FrandsenF,Dam2JohansenK,RasmussenP.Traceelmentsfromcombustionandgastificationofcoalanequilibriumapproach.Progressinenergyofcombustionandscience,1994,20:115138.11,,,.SO2NOx.,1998,26(5):486491.8322©1995-2004TsinghuaTongfangOpticalDiscCo.,Ltd.Allrightsreserved.