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,,(,411105):,,,.275m/sL/G=30L/m367%31SO2150010-6pH=80,87%,.:;;;:X7013:A:0250-3301(2001)05-06-0029:(96-910-01-028-05):(1942~),,,.:2001-01-21AMethodofDesulfurizationwithCalciumSulfiteandItsMechanismTongZhiquan,ChenZhaoqiong,PengZhaohui(DepartmentofEnvironmentalEngineeringofXiangtanUn-iversity,Xiangtan411105,China)Abstract:Directingtothescalingproblemlyinginwetdesulfurizationwithlimeslurry,amethodofdesulfurizationwithcalciumsulfitewasproposed.Reactionmechanismandtheeffectsofdifferentconditionsondesulfurizationefficiencywerestudied.Theoptimumconditionswereobtained,i.e.airvelocityof275m/sinemptytower,L/G=30L/m3,solidcontent67%,airtemperature31,concentrationinletofSO2150010-6andinletsuspensionpHof80.Undertheconditions,thedesulfurizationefficiencywasabout87%.Thepresentedmethodtheoreticallyandpracticallysolvedthescalingproblems,whichisanovelindirectlime-methodwithCa-containedmaterialasdesulfurizationagent.Keywords:calciumsulfite;desulfurization;desulfurizationagent;novellimemethod,,8302%,.,Ca/S,,.,,.,.SO2(),..111,2.1,,SO2,,H2SO3,:SO2(g)SO2(aq)SO2(aq)+H2OH2SO3H2SO3H++HSO-3HSO-3H++SO2-3(1)(2)(3)(4)()1SO2,pH[1].1,pH7~8,SO2-3.22520019ENVIRONMENTALSCIENCEVol.22,No.5Sept.,2001Ca(OH)20185g/100gH2O(0),pH=126.,SO2-3.,pH,CO2CO2-3.1pHFig.1TherelationbetweenpHandsulfurionofsolution2,H+Ca(OH)2OH-H2O,Ca(OH)2Ca2+SO2-3(H2O)CaSO31/2H2O,CO2-3CaCO3:Ca(OH)2(s)Ca(OH)2(aq)Ca(OH)2(aq)Ca2++2OH-H++OH-H2OCa2++SO2-3+1/2H2OCaSO31/2H2OCa2++CO2-3CaCO3(5)(6)(7)(8)(9)(),O2,CaSO3CaSO42H2O.CaSO31/2H2OCaCO3CaSO42H2O100gH2O00043g(18)00065g(20)0223g(0),,,.12(1),pH6~8,pH45~56(2).1,pH,HSO-3,(4).,CaSO3SO2-3(3)H+(12)HSO-3,CaSO3Ca2+(3)(12)HSO-3(13)Ca(HSO3)2.:CaSO31/2H2O(s)CaSO3(aq)+1/2H2OCaSO3(aq)Ca2++SO2-3H++SO2-3HSO-3Ca2++2HSO-3Ca(HSO3)2(10)(11)(12)(13)()(),(CaSO31/2H2O)Ca(HSO3)2(Ca(HSO3)2,,).,pH,CO2,(9).,CaSO31/2H2OCaCO3,,.,CaSO31/2H2O,CaSO42H2O,225%CaSO42H2O[2].,CaSO42H2O.(12),CaSO3SO2-3(3)H+,(I),SO2.(12),(L/G=30L/m3v=25m/sSO2150010-6)pH=875%4,pH,2.2,(12),pH,(3)H+,pH309.30222pHFig.2pHofoutputsolutionfromdifferent3CaOpHFig.3TherelationbetweenpHvalueandamountofCaO(CaSO31/2H2O)[3],CaO,3.pH=6Ca(HSO3)2Ca(OH)2CaSO31/2H2O.(2),Ca(OH)2Ca(HSO3)2,CaSO31/2H2O,:Ca(OH)2+Ca(HSO3)22CaSO31/2H2O+H2O,CaSO31/2H2O,,,.2214,SO2SO2,,,SO2.SO2..1SO223456784Fig.4Theexperimentalequipmentandflowchart654mm,9025mm,173%.22(CaSO31/2H2O)CaSO31/2H2O,CaCl2Na2SO3:CaCl2+Na2SO3+1/2H2O=CaSO31/2H2O+2NaCl2h,NaCl,Cl-,.23SO2KaneKM900SN,pHHANNAHI9321pH,SO2-3Ca2+SO2-4EDTA.331(1)L/G=25L/315m3,75%,SO2150010-6,pH=701,5.,,,;,,.,,.5Fig.5Theeffectofairvelocityinemptytowerondesulfurizationefficiency(2)v=20m/s,75%,SO2150010-6,pH=701,L/G6.,L/G,SO2CaSO31/2H2O,SO2Ca(HSO3)2;6Fig.6TheeffectofL/GondesulfurizationefficiencyL/G,,,2.(3)v=185m/s,L/G=30L/m3,SO2150010-6pH=707.SO2-3,CaSO31/2H2O,(12).,,.7Fig.7Theeffectofsolidcontentondesulfurizationefficiency(4)SO2v=20m/s,L/G=30L/m3,75%pH=701,SO28.,SO2,.SO2.8SO2Fig.8TheeffectofinitialconcentrationofSO2ondesulfurizationefficiency(5)pHv=322220m/s,L/G=30L/m3,75%SO2150010-69.pH,(I),.,pH8,;pH9,.pH80,SO2(II)CaSO31/2H2O.pH=7~8,CaSO31/2H2O,.9pHFig.9TheeffectofinitialpHondesulfurizationefficiency,pHSO2,().321L(pH=466),10888gCaO(10%),,t=0,pH(10).10,t5min,pH70.,,6min.10pHFig.10TherelationcurveofpHwithtime33(1)3(644mm),v=20m/s,L/G=55L/m3,10%,26,SO2150010-6pH=801.,,L/G=55L/m3,85%.13Table1TheexperimentresultswiththreepieceofsieveplatesSO210-615061515150015101515SO210-6220228230210220pH504505506502503/%8548584786185(2)XPXP,,3XP,11.275m/s(Q=700m3/h)L/G=30L/m367%31SO2150010-61SO2234567AP11Fig.11Thepilot-plantequipmentandflowchartpH=80pH80,3h,2.:,87%;1,85%~87%,XP335L/G30L/m355L/m3,..23XPTable2TheexperimentresultswiththreepieceofXPtowertraysSO210-615251579152715241626SO210-6187208190181203/%8778688768818754,7203065~130t/h.-XP[4],90%,XPSO2..SO2,,.3.82%~89%,.5(1),..3Table3Afewappliedexamplesinindustry/th-1/mgm-3/mgm-3/%/mgm-3/mgm-3/%6512375103299110304170382165325003029916694823877351325473299472237758895(2),85%,SO2.(3)pH,SO2,.pH,Ca(OH)2SO2CaSO31/2H2O.(4)pH,pH,pH.:1HussAetal.OxidationofAque0usSulfurDioxide.1.Ho-mogeneousManganese(II)andIron(II)CatalysisatLowpH.J.Phys.Chen.,1982,86:4225.2PaulN.Cheremisionff&RichardA.Young.AirPollutionControlandDesignHandbook.Part2,NewYorkandBasel:MarcelDekkerInc.,1977.3,.pH().,1996,17(5):42~44.4,.-XP.:.().:1998.3422