000000湿法烟气脱硫系统的pH值及控制步骤分析

:2004212208:(19762),,,,,.E2mail:[e-mail]:167223961(2005)0520037204pH,,,(,250013):,25,pH,SO2,-SO2.,,.:;;pH;:TK09:AAnalysisonpHvalueandcontrolstepinwetFGD(fluegasdesulfurization)HOUQing2wei,SHIRong2gui,LIYong2chen,GAOShan2bin(ShandongElectricPowerEngineeringConsultingInstitute,Jinan250013,China)Abstract:Bythemethodofphysicalchemistry,thesystemoflimestonewetFGDwith25isinvestigated.ThecontrolrangeofpHvaluehasbeenpresented,thedesulfurizationutmostofSO2ispracticallyascertainedandthemaincontrolstepofFGDsystemthatSO2diffusionisconcretelyindicatedduringthesystemoperation.Theanalysisofphysicalchemistrycanbeusedasthedefinitereferenceoftheoryresearchandtherelevantdi2rectionfortheselectionofoperationparametersinFGD.Keywords:wetfluegasdesulfurization(WFGD);physicalchemistry;pHvalue;controlstep0SO2,FGD70%.,,,,SO2;,,SO2.SO2,,1.,FGD.,,,,pH.1pH1.1SO2pHSO2,pH,355Vol.35No.5()JOURNALOFSHANDONGUNIVERSITY(ENGINEERINGSCIENCE)200510Oct.2005,.,pHCaCO3,.,SO2+H2O,SO2pH.SO2+H2O,2524:SO2(g)ZSO2(aq),H(SO2)=(SO2(aq))P(SO2)=1.22810-5mol/(lPa),(1)SO2(aq)+H2OZH++HSO-3,KS1=(H+)(HSO-3)(SO2(aq))=1.38910-2mol/l,(2)HSO-3ZH++SO2-3,KS2=(H+)(SO2-3)(HSO-3)=6.71710-8mol/l.(3):(H+)=(HSO-3)+2(SO2-3)+(OH-)(4)(1)(2):(HSO-3)=H(SO2)KS1P(SO2)(H+),(5)(1)(2)(3):(SO2-3)=H(SO2)KS1KS2P(SO2)(H+)(H+),(6):(OH-)(H+)=10-14,(7)(5),(6),(7)(4):((H+))3=(H(SO2)KS1P(SO2)+10-14)(H+)+2H(SO2)KS1KS2P(SO2).(8),SO28.910-5mol/l,P(SO2)=2.0102Pa.(8):(H+)=5.84410-3mol/(lpH)=2.233,pH2.233,.1.2CaCO3pH,,CaCO3+H2O+CO2,CaCO3pH.CaCO3+H2O+CO22524:CACO3(s)ZCa2++CO2-3,Kspc=(Ca2+)(CO2-3)=2.810-9mol2/l2,(9)HCO-3ZCO2-3+H+KC1=(CO2-3)(H+)(HCO-3)=4.810-11mol/l,(10)H2O+CO2(g)ZHCO-3+H+,KC2=(HCO-3)(H+)P(CO2)=4.310-7mol/l.(11):(H+)+2(Ca2+)=(HCO-3)+2(CO-3)+(OH-),(12)(11):(HCO-3)=KC2P(CO2)(H+),(13)(10),(11):(CO2-3)=KC1KC2P(CO2)(H+)(H+),(14)(9),(10),(11):(Ca2+)=Kspc/(CO2-3)=KspcKC1KC2P(CO2)((H+))2,(15)(7),(13),(14),(15)(12),:2KspcKC1KC2P(CO2)((H+))4=2KC1KC2P(CO2)+(KC2P(CO2)+10-14)(H+)-((H+))3.(16)CO215%,CO21.5104Pa,(13),:(H+)=3.21710-6mol/lpH=5.483,pH2.2335.483.,,pH.1.3pH,,,.pH,38()35HSO-3SO2-3(pH1.82,H2SO3),15.1pHFig.1RelationshipbetweenionfractionandpHvalueinsolution1,pH4.85.6,HSO-3,,,;CaCO3pH,pH4.85.48SO2CaCO36.,,pH.22.1SO2(6)(15):(SO2-3)(Ca2+)=H(SO2)KS1KS2P(SO2)KSPCKC1KC2P(CO2),,(17)SO2-3+Ca2+ZCaSO3,25,KSPS=(SO2-3)(Ca2+)=3.110-7mol2/l2.(17)(SO2)=1.2410-7mol/l,.,CaCO3,SO2,CaCO3,,,pH.,.2.2CaCO3pHCaCO3,.:(H+)+2(Ca2+)=(HSO-3)+2(SO2-3)+(HCO-3)+2(CO2-3)+(OH-),(18)(17):(Ca2+)=KSPS(SO2-3),(5),(6),(7),(13),(14),(15)(18):2KSPSH(SO2)KS1KS2P(SO2)((H+))4=2H(SO2)KS1KS2P(SO2)+2KC1KC2P(CO2)+KC2P(CO2)(H+)+H(SO2)KS1P(SO2)(H+)+10-14(H+)-((H+))3.(19)P(CO2)=1.5104Pa,P(SO2)=2.0102Pa(19),:(H+)=5.00910-4mol/lpH=3.300.2.3SO2pHSO2,.(15)(SO2-3)=KSPS(Ca2+),(HSO-3)=(H+)(SO2-3)KS2=KSPS(Ca2+)KS2(H+)(7),(13),(14),(15)(18):2KSPCKC1KC2KCO2(H+)4=2KSPSKSPCKC1KC2P(CO2)+2KC1KC2P(CO2)+KC2P(CO2)(H+)+KSPSKC1KC2P(CO2)(H+)KSPCKS2+10-14(H+)-((H+))3,(20),:(H+)=3.29710-6mol/lpH=5.475.CaCO3pH.,SO2.3,.,,5,:pH39,pH,.:[1],./[J].,2002,18(1):123.HANQi,LIZhong2hua.ResearchonlimestonegypsumWFGD[J].ElectricPowerEnvironmentalProtection,2002,18(1):123.[2].[D].:,2001.KONGHua.ExperimentalandtheoreticalstudyonlimestoneWFGD[D].Hangzhou:TheCollegeofMechanicalandEnergyEngineering,ZhejiangUniversity,2001.[3]BROGRENC,HANNATK.Theimpactoftheelectricalpo2tentialgradientonlimestonedissolutionunderwetFGDcondi2tions[J].ChemicalEngineeringScience,1997,52(3):310123106.[4]WALLISM,BERGERI.Amodelforabsorptionofsulphurdioxideintolimestoneslurry[J].ChemicalEngineeringJour2nal,1993,51(2):209922108.[5].[M].:,2002.ZHONGQin.RemovaltechnologyofSO2andNOxinfluegasandengineeringinstances[M].Beijing:ChemicalIndustryPress,2002.[6].[D].:,2001.PENGChao2hui.Studyoncalciumsulfitedesulfurization[D].Xiangtan:TheCollegeofEnvironmentEngineering,XiangtanUniversity,2001.(:)(32)HUANGXing2hua,SHENKun2quan,SHIJian2ji,etal.Numericalsimulationofsteamflowandheattransferforpowerstationcondenser[J].PowerEngineering,1998,18(3):79286.[2],,,.125MW[J].,2001,21(3):126321266.WANGGuo2shan,MAOXin2qing,TIANZi2ping,etal.NumericalanalysisofthefluidflowandheattransferpropertiesofThecondenserof125MWsteamturbine[J].PowerEngineering,2001,21(3):126321266.[3],,,.PPOC3.0[J].,2001,21(5):145021454.WANGGuo2shan,MAOXin2qing,HUGuo2xin,etal.Developmentofaquasi2three2dimensionalcomputerprogramforfluidflowfieldsandheattransferperformanceofpowerplantcondensers:PPOC3.0W[J].PowerEngineering,2001.21(5):145021454.[4].[M].:,1988.FANWei2deng.Computersimulationofthefluidflow,heatandmasstransferandcombustionprocess[M].Beijing:UniversityofScienceandTechnologyofChinaPress,1988.(:)40()35