GE燃气轮机内部资料3

GEPowerSystemsSupportforEliminationofOxidationCatalystRequirementsforGEPG7241FADLNCombustionTurbinesBrahimRichani,Ph.D.Manager,EnvironmentalandAcousticEngineeringGEPowerSystemsJoelChalfinManager,GT/CCEnvironmentalComplianceGEPowerSystemsWhitePaper(August2001)gGER-4213SUPPORTFORELIMINATIONOFOXIDATIONCATALYSTREQUIREMENTSFORGEPG7241FADLNCOMBUSTIONTURBINESGER-4213GEPowerSystemsWhitePaperAugust2001Page1ApplicabilityThispositionpaperappliestoGEPG7241FAcombustionturbineswithDLNcombustorsfir-ingnaturalgasandlocatedinallattainmentareasandozonenon-attainmentareas.ForallotherGEheavy-dutyframemachines,ownersareadvisedtocontacttheirGEPowerSystemssalesrepresentativeforinformationregardingoxidationcatalystsandrelatedrequirements.AbstractEmissionsregulatoryrequirementshavebecomemorestringentforcombustiontur-bines(CTs),generallyrequiringinstallationofpost-combustioncontrolsregardlessofuncon-trolledemissionlevels,plantlocation,costs,processfeasibility,orresultingenvironmentalimpacts.Federalandstateregulatoryagencieshavesoughttojustifypost-combustioncontrolsprimarilyonthegroundsthatsomeexistinginstallationsarecurrentlyusingoxidationcata-lystsforcarbonmonoxide(CO)control.However,a“one-size-fits-all”approach,whereallunitsarerequiredtoinstallaparticulartech-nologywithoutconsiderationofindividualizedfactors,isindirectconflictwiththeCleanAirAct(CAA)BestAvailableControlTechnology(BACT)analysisproceduresandrequirements.TheBACTanalysisforCO(oranycriteriapol-lutant)mustweighavarietyoffactorsincludingenergy,environmentalandeconomicimpacts.DryLowNOx(DLN)combustorsforGEPG7241FAcombustionturbinesarenowdemonstratinguncontrolledCOemissionsinarangesolowthattherequirementtoaddanoxidationcatalystontheseunitswillonlyservetoreduceefficiencyandoutput;producenega-tiveenvironmentalimpacts;and,inlightofthemeasureddata,willnotyielddetectableCOemissionsreductionbenefitsundernormaloperatingconditions.ThecomparisonwithexistinginstallationsusingCOcatalystsappearstobetheprimaryfactorinfluencingregulatoryagenciestoinsistontheinstallationofoxidationcatalystsonallcombustionturbineunits.However,twoaddi-tionalfactorsarealsoconsideredinthispaper;theimpetusforexpeditedpermitting,andtheanticipatedfederalregulationforhazardousairpollutant(HAP)emissionsfromcombustionturbines.TheobjectiveofthispaperistodemonstratethattheinstallationofanoxidationcatalysttoachievelowerCOlevelsfromGEPG7241FADLNcombustionturbinessitedinCOattain-mentareasandozonenon-attainmentareasshouldnotberequiredbystate,local,and/orfederalregulatoryagencies.Theadditionofoxidationcatalyststotheseunitsresultsinmin-imalCOemissionsreduction,addsunnecessarycosts,andproducesnegativeenvironmentalimpacts.1.0IntroductionStateandfederalregulatoryagenciesarerequir-ingoxidationcatalystsasBACToncombustionturbinesinanattempttoachievelowerCOemissions.Suchrequirementsaremakingitdif-ficultforownerstoavoidtheinstallationofoxi-dationcatalystsasadd-oncontrols,regardlessoftheuncontrolledCOemissionslevels.Thereg-ulatory-mandatedBACTprocessisbeingcir-cumventedandU.S.EPA’sownBACTguidanceisbeingignored.TheCleanAirActclearlyrequiresthataBACTdeterminationbecon-ductedona“case-by-case”basis;howeveritappearsthatinmanycasestheregulatoryagen-ciesareinfluencingapplicants’controltechnol-SUPPORTFORELIMINATIONOFOXIDATIONCATALYSTREQUIREMENTSFORGEPG7241FADLNCOMBUSTIONTURBINESGER-4213GEPowerSystemsWhitePaperAugust2001Page2ogychoicesandtheirBACTdeterminationbasedonthefollowingfactors:Existinginstallationsofvariousmanufactur-ers’unitsthatareusingCOcatalysts(i.e.,“presumptiveBACT”)Applicants’demandsforanexpeditedper-mittingprocessCurrentlynonexistent,butanticipated,MaximumAchievableControlTechnology(MACT)requirementsforHAPSConsequently,theregulatoryagenciesappeartobeexcludingotherimportantfactorsintheirBACTdeterminations,suchas:CosteffectivenessandfeasibilityofcontrolEvaluationofcollateralenvironmentalimpactsEvaluationofexpectedCOemissionsonpublichealthGEPG7241FADLNnaturalgas-firedcombus-tionturbineshaveconsistentlydemonstrateduncontrolledCOemissionsbelow9partspermillionbyvolumedry(ppmvd)atbaseload.ArequirementtoaddanoxidationcatalysttoaGEPG7241FADLNcombustionturbinewithsingledigitCOemissionswillreduceefficiencyandoutput,andproducenegativeenvironmen-talconsequenceswhileyieldinginsignificant(1ppm)reductioninCOemissionsundernormaloperatingconditions.Forareasdesig-natedasattainmentforcarbonmonoxide,itbecomescriticalthattheBACTanalysisforCOincludesenvironmental,costeffectiveness,andpotentialhealthimpacts.Thefollowingpro-videsjustificationofwhyBACTdeterminationsforCOemissionsforGE’sPG7241FADLNunitsshouldresultinaconclusionof“NoAdd-onControls.”2.0ExistingInstallationsAreviewofexistingCTinstallationslocatedinattainmentareaswhichareusingoxidationcat-alystsindicatesthatuncontrolledCOemissionlevelsfromtheseunitsaremuchhigherthanthedemonstratedemissionlevelsfromGE’sPG7241FADLNcombustionturbines.Theexistinginstallationsreviewedhaveuncon-trolledCOemissionratesintherangeof15to25ppmvd,whileGE’sPG7241FADLNshavedemonstrateduncontrolledCOlevelsofle