简介:Inthisstudy,titaniumdioxidesupportedbymulti-walledcarbonnanotubes(MWCNTs/TiO2)andCr-dopedTiO2supportedbyMWCNTs(MWNTs/Cr-TiO2)weresynthesizedbythesol-gelmethod.Thepreparedsampleswerecharacterizedbytransmissionelectronmicroscopy,X-rayphotoelectronspectroscopy,X-raydiffraction,theBrunauerEmmett-Telleranalysis,andtheRamanspectroscopy.TheoxidationandefficiencyforremovalofSO2inasimulatedfluegaswereinvestigatedexperimentallyinafixed-bedreactor.The15%MWCNTs/Cr-Ti02sampledisplayedexcellentadsorptionproperties,andaSO2removalrateequatingto30.4151mg/gfromthesimulatedfluegascontaining2300μg/gofSO2,8%of02,and5%ofH20wasachievedunderoptimalconditionscoveringatemperatureof333.15K,andaspacevelocityof1275h^-1.TheadsorptionprocesswasenhancedbecauseCrdopingmodifiedtheporestructureandinhibitedthegraingrowthofTiO2.Inaddition,theFreundlichandLangmuirmodelsrevealedthatSO2wasmainlyadsorbedthroughchemicaladsorptiononthesamplesurfaces,andthethermodynamicmodelanalysisindicatedthattheadsorptionwasaspontaneous,exothermic,andentropy-reducingprocess.TheadsorptionkineticsofSO2canbedescribedbythepseudosecond-orderkineticandtheBanghamdynamicsmodels.Thepossiblereactionmechanisminvolvedindesulfurizationprocesswasalsoproposed.
简介:随着污染物排放标准的日益提高,为降低硫磺回收装置排放尾气中的SO2浓度,从实际出发,分析和探讨了相应的减排措施:升高反应炉炉膛温度、控制好CLAUSE反应炉配风比例和降低硫冷凝器出口温度等,提高硫磺装置系统的硫收率;将部分自产净化尾气作为液硫鼓泡脱气的汽提气,并把含硫废气进行加氢处理,高效净化硫磺尾气;硫池气和脱硫醇氧化尾气改送至CLAUSE反应炉进行制硫;在硫磺回收装置废热锅炉至尾气焚烧炉间的跨线上增加蝶阀,设置氮封,降低或避免高浓度气体泄漏;提高贫胺液品质,降低吸收塔顶温度,提高吸收塔脱硫效果;碱洗处理吸收塔后尾气或将吸收塔后尾气送至脱硫脱硝系统处理。
简介:Nitrobenzene-containingindustrialwastewaterwasdegradedinthepresenceofozonecoupledwithH2O2byhighgravitytechnology.Theeffectofhighgravityfactor,H2O2concentration,pHvalue,liquidflow-rate,andreactiontimeontheefficiencyforremovalofnitrobenzenewasinvestigated.TheexperimentalresultsshowthatthehighgravitytechnologyenhancestheozoneutilizationefficiencywithO3/H2O2showingsynergisticeffect.ThedegradationefficiencyintermsoftheCODremovalrateandnitrobenzeneremovalratereached45.8%and50.4%,respectively,underthefollowingreactionconditions,viz.:ahighgravityfactorof66.54,apHvalueof9,aH2O2/O3molarratioof1:1,aliquidflowrateof140L/h,anozoneconcentrationof40mg/L,aH2O2multipledosingmodeof6mL/h,andareactiontimeof4h.Comparedwiththeperformanceofconventionalstirredaerationmixers,thehighgravitytechnologycouldincreasetheCODandnitrobenzeneremovalraterelatedwiththenitrobenzene-containingwastewaterby22.9%and23.3%,respectively.
简介:TheesterificationoflauricacidwithmethanolcouldbeefficientlycatalyzedbyZrOCl2·8H2O,andthisreactionwasstudiedtodevelopagreenmethodforbiodieselproduction.Theinfluencingfactors,suchasamountofcatalyst,reactiontimeandmolarratioofacidtomethanol,wereinvestigated.TheresultsindicatedthattheZrOCl2·8H2Ocatalystshowedhighcatalyticactivity,andgavea97.0%methyllaurateconversionrateunderthefollowingoptimizedconditions,viz.:alauricacid/methanolmolarratioof1:10,acatalystdosageof4%,andareactiondurationof2hatmethanolrefluxingtemperature.Thecatalystcouldbeeasilyrecoveredwhileitsactivitycouldbewellretainedafterthreecycles.TheZrOCl2·8H2Ocatalystalsoexhibitedexcellentcatalyticactivityfortheesterificationofdifferentfreelong-chainfattyacids(includingnonedibleoilswithhighacidvalue)withdifferentshortcarbonchainalcohols.Therefore,theZrOCl2·8H2Ocatalysthasgoodpotentialforthesynthesisofbiodieselfromlow-costfeedstockssuchaswastevegetableoilsandnon-edibleoils.
简介:AninnovativeapproachtoH2Scapturehasbeendevelopedusingseveralmetal-basedionicliquids([Bmim]Cl·CuCl2,[Bmim]Cl·FeCl3,[Bmim]Cl·ZnCl2,[Bmim]Br·CuCl2,and[Bmim]Br·FeCl3)immobilizedonthesol-gelderivedsilica,whichissuperiortopurelyviscousionicliquidwithacruciallimitofhightemperature,lowmasstransferrate,andmassloss.TheadsorbentswerecharacterizedbytheFouriertransforminfraredspectrometer,transmissionelectronmicroscope,N2adsorption/desorption,X-rayphotoelectronspectroscopy,andthermalanalysistechniques.TheeffectsofthemetalandhalogeninIL,theloadingamountofIL,andtheadsorptiontemperaturewerestudiedbydynamicadsorptionexperimentsatagasflowrateof100mL/min.TheH2Sadsorptionresultshaveshowedthattheoptimaladsorbentandadsorptiontemperatureare5%[Bmim]Cl·CuCl2/silicageland20-50℃,respectively.H2Scanbecapturedandoxidizedtoelementalsulfur,and[Bmim]Cl·CuCl2/silicagelcanbereadilyregeneratedbyair.TheexcellentefficiencyofH2Sremovalmaybeattributedtotheformationofnano-scaledandhigh-concentration[Bmim]Cl·CuCl2confinedinsilicagel,indicatingthattheimmobilizationof[Bmim]Cl·CuCl2onthesol-gelderivedsilicacanbeusedforH2Sremovalpromisingly.