BTF系统处理硫化氢废气工程设计外文参考文献译文及原文.doc
- 文档编号:1889225
- 上传时间:2023-05-02
- 格式:DOC
- 页数:24
- 大小:314KB
BTF系统处理硫化氢废气工程设计外文参考文献译文及原文.doc
《BTF系统处理硫化氢废气工程设计外文参考文献译文及原文.doc》由会员分享,可在线阅读,更多相关《BTF系统处理硫化氢废气工程设计外文参考文献译文及原文.doc(24页珍藏版)》请在冰点文库上搜索。
本科毕业设计(论文)
外文参考文献译文及原文
学院:
环境科学与工程学院
专业:
环境工程
年级班别:
2004级
(1)班
学号:
3104008168
学生姓名:
谢辉
指导教师:
陈凡植教授
2008年6月11日
1
Biologicalsweeteningofenergygasesmimicsinbiotricklingfilters
MarcFortunya,c,JuanA.Baezaa,XavierGamisansb,CarlesCasasa,JavierLafuentea,
MarcA.Deshussesc,*,DavidGabriela,1
aDepartmentofChemicalEngineering,UniversitatAuto`nomadeBarcelona,EdificiQ,CampusdeBellaterra,08193Bellaterra,Barcelona,Spain
bDepartmentofMiningEngineeringandNaturalResources,UniversitatPolite`cnicadeCatalunya,Manresa,Spain
cDepartmentofChemicalandEnvironmentalEngineering,UniversityofCalifornia,Riverside,CA92520,UnitedStates
Received25July2007;receivedinrevisedform27October2007;accepted29October2007
Availableonline21December2007
Abstract
Removalofhydrogensulfidefromwasteandenergy-richgasesisrequired,notonlybecauseofenvironmentalhealthandsafetyreasons,butalsobecauseofoperationalreasonsifsuchgaseshavetobeusedforenergygeneration.Abiotricklingfilterfortheremovalofultra-highconcentrationsofH2Sfromoxygen-poorgasesisproposedandstudiedinthiswork.Twolaboratory-scalebiotricklingfilterswereusedtostudythestartupperiodandtodeterminethelong-termperformanceofthegassweeteningprocess.TheinletH2Sconcentrationrangedfrom900to12000ppmvandtwodifferentpackingmaterialswereinvestigated.TherewasnotoxicityeffectobservedevenatathehighestH2Sconcentration,andmaximumeliminationcapacitiesof280and250gH2Sm-3h-1wereobtainedatgascontacttimesof167and180s,respectively.Elementalsulfurandsulfatewerefoundtobethemostabundantend-productsofthebiologicaloxidationofsulfidewhenoperatedundermicroaerophilicconditions.Thebiotricklingfilterwasabletoquicklyrecoveritsnominalperformanceafterdifferentloadincreasesandsystemshutdownssimulatingfieldoperation.Theresultsreportedhereshowthatbiotreatmentcanbeaninterestingalternativetoconventionalgassweeteningsystemsnormallyusedforsuchapplications.
Keywords:
Hydrogensulfide;Gassweetening;Biotricklingfilter;Desulfurization;Fuelgas;Biogas
1.Introduction
Hydrogensulfideisacommonreducedsulfurcompoundfoundinseveralindustrialwastegases.Itiseasilyrecognizablebyitsoffensiverotteneggsodor.However,odornuisanceisnotthemainissueinenergy-richgasessuchasbiogasfromanaerobicdigesterswhichmaycontainH2Sconcentrationsexceeding500ppmvandupto20000ppmv(2%v/v)(WoodcockandGottlieb,2004).Insuchcases,H2Sremoval,oftencalledgassweetening,isnecessarytoavoidcorrosionofcombustionenginesandSOxgenerationinthefluegases.Thus,removalofH2Sfromwasteandenergy-richgasesisrequired,notonlyforenvironmentalhealthandsafetyreasonsbutalsoforoperationalreasons.
Sofar,themostcommonlyusedtreatmenttechnologyforH2Sremovalisselectiveabsorptioninaminessuchasdiglycolamine,monoethanolamine,methyldiethanolamineorothercompoundsthathaveahighaffinityforH2S(WoodcockandGottlieb,2004).Althoughtheseprocesseshavebeenextensivelyandsuccessfullyapplied,theyhavemanydrawbackssuchashighenergyandoperatingcostsduetotheregenerationoftheabsorbentphase.Inthiscontext,biologicalprocessesforairpollutioncontrolaregainingpopularity(Deshusses,1997;Devinnyetal.,1999;KennesandVeiga,2001)buthavenotyetbeengenerallyappliedtotreatmentofH2Sinenergy-richgases.
BiologicalH2Sutilizationasenergysourceforlithoautotrophicorganismsisawell-knownprocessthatcanbedescribedwiththefollowingoverallreactions(Eqs.
(2),(3)).Notethatoxidationtoelementalsulfurcanonlyhappenunderoxygenlimitedconditions,andthatexcessoxygenisrequiredfortheformationofsulfate(Kuenen,1975;WoodcockandGottlieb,2004).
Biofilters,bioscrubbersandbiotricklingfiltershavebeenproventobeasuitable,environmentallyfriendlyandcosteffectivealternativeforwastegastreatment,especiallyforthetreatmentoflowconcentrationsofH2S(YangandAllen,1994;Devinnyetal.,1999;GabrielandDeshusses,2003a;KimandDeshusses,2005).However,therehasbeenlimitedsuccessindealingwithhighconcentrationsofH2S(>1000ppmv)usingbiofilters,biotricklingfiltersandbioscrubbersandonlyfewindustrialprocesseshavebeenfullydevelopedforsuchapplication.Amongthem,theThiopaqprocess(Paques,TheNetherlands),andtheBiopuricprocess(Biothane,USA)aretheonlyonesspecificallydevelopedfortheremovalofhighconcentrationsofH2Sfrombiogasorfuelgas.TheThiopaqprocessisatwo-reactorsystemconsistingofaconventionalcausticscrubberfollowedbyanexpandedbedbioreactorfortherecoveryofthespentcausticandforelementalsulfurgeneration.TheBiopuricprocessisalsoatwo-reactorsystem,whichcombinesaconventionalchemicalscrubberfollowedbyabiologicaltreatmentstep.Littleispubliclyknownaboutthelatterprocess.
Alternativeandsustainableprocessesneedtobedeveloped.Thus,thepurposeofthisstudywastoevaluatethetechnicalfeasibilityoftreatinghighconcentrationsofH2Sinlaboratory-simulatedbiogasorfuelgasusingasinglebiotricklingfilterreactor,andattempttoproducemostlyelementalsulfurwhichcanbeeasilydisposedorrecovered.Unliketheabovementionedcommercialsystems,thetreatmentdemonstratedinthispaperreliesonasinglereactorsystem.AlthoughH2Streatmenthadbeenwidelyreportedinbiofiltersandbiotricklingfilters(YangandAllen,1994;Devinnyetal.,1999;GabrielandDeshusses,2003a;KimandDeshusses,2005),thepresentstudyisdifferentbecauseitdealswithultra-highH2Sconcentrationsingasesthatareinitiallyoxygen-free.Operationatclose-to-neutralpHwaschoseninordertoimprovetheH2SabsorptioncapacityoftheliquidphasealthoughmanyoftheH2Sdegradingorganisms,likethegenusThiobacillus,haveacidicoptimumgrowingpH(RobertsonandKuenen,1999,2002).Also,absorptionandoxidationofH2StoelementalsulfurispHneutralasshownbyaddingEqs.
(1)and
(2).
Twolaboratory-scaleprototypeswithdifferentpackingmaterialswereusedtoevaluatetheperformanceintermsofH2Sremovalefficiency(RE=(Cin-Cout)/Cin)andeliminationcapacity(EC=(Cin-Cout)*Q/V,whereQisthegasflowandVisthebedvolume).TheratioofSO42-/S0producedunderdifferentoperatingconditionsaswellastherobustnessofthebioreactorwhenexposedtodifferentperturbationswerealsoassessed.
2.Materialsandmethods
BothexperimentalReactorsAandB(seeTable1)werebasedonthesamedesign(Fig.1)butwithslightlydifferentcharacteristics.Theyconsistedofabiotricklingfilterreactoroperatedinanupflow,counter-currentmode,fedwithamimicofbiogasorfuelgascontainingmostlynitrogen,CO2andH2Sasneeded.Althoughthegasdidnotcontainanymethaneorgaseoushydrocarbon,itwasareasonablemimicoffuelgasorbiogasforH2Streatmentpurposes.ThisisbecauseH2Sisdegradedbylithoautotrophicorganismswhichhavebeenshownnottobeaffectedbythepresenceoforganiccarbonsources(CoxandDeshusses,2002).Evenso,thepresenceofheterotrophicmethanotrophicbacteriawouldresultinsomecompetitionforoxygenwiththeH2Sdegraders.Sincemethaneisonlysparinglysolubleinwater(Sander,1999)andnotwelldegradedinbiofiltersorbiotricklingfilters(Nikiemaetal.,2005),onlyaslightamountofextraoxygenwouldneedtobesuppliedtocompensateforoxygenconsumptionbyheterotrophicorganisms.Duringtheexperiments,asmallmeteredstreamofair(asrequiredfortheaerobicoxidationofH2S)wasaddedtothebiogasorfuelgasmimic.
Mineralmediumcontaining(gl-1)KNO3,1;KH2PO4,1;K2HPO4,1;NaCl,1;MgSO4,0.2;CaCl2,0.02;traceelements(Pfenningetal.,1981),1mll-1forReactorAandNH4Cl,1;KH2PO4,1;K2HPO4,1;MgSO4.7H2O,0.5;CaCl2,0.25;traceelements(Pfenningetal.,1981),1ml1-1forReactorBwasalsocontinuouslyfedtosupplynutrientsandwashoutby-products.InorganiccarbonwassuppliedasCO2viathegasphase(ReactorA)ordissolvedHCO3-intheliquidphase(ReactorB).
ReactorAwaspackedwithrandomlydumped2*2*2cmcubesofopenporepolyurethane(PU)foam(EDT,Eckental,Germany).ThePUfoampackingwasdevelopedspecificallyforbiotricklingfiltration(GabrielandDeshusses,2003a;PhilipandDeshusses,2003;KimandDeshusses,2005).Ithasahighspecificsurfacearea(600m2m-3)andalowdensity(35kgm-3),arelativelyfinemesh(4–6porespercm),andalowcompressionstrength(5–10kPa).ThePUfoambedhadaninitialporosityofabout0.97.
ReactorBwaspackedwithpolypropyleneHDQ-PAC(LantecProductsInc.,CA,USA)witha4*4mmgridopening.TheHDQ-PACisacommonwetscrubberstructuredpackingwithaslightlylowerspecificarea(430m2m-3)thanthefoamandwiderpores.Acylinderofstructuredpackingwascuttotightlyfitinsidethebiotricklingfilterreactor.Theinitialbedporositywas0.88.HDQ-PACwasselectedbecauseofitsstructuralstrengthandbecauseitsopenstructuremayminimizetheretentionofsulfurexpectedfromtheproposedtreatment.
Reactorswereoperatedcontinuouslyforaperiodof3months(ReactorA)and7months(ReactorB)inordertotestarangeofoperatingconditions.Bothreactorswhereinoculatedwithsulfur-oxidizingbiomassinordertospeedupthestartupperiod.ReactorAwaspackedwithPUfoamcubestakenfromalab-scalebiotricklingfiltertreatinglessthan100ppmvH2S,whereasReactorBwaspackedwithcleanHDQ
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- BTF 系统 处理 硫化氢 废气 工程设计 外文 参考文献 译文 原文
![提示](https://static.bingdoc.com/images/bang_tan.gif)