Hybrid SNCR/InHybrid SNCR/In-Duct SCRDuct SCRSystemDale PfaffDale PfaffFUEL TECH, INC.FUEL TECH, INC.Batavia, ILBatavia, ILRich AbramsRich AbramsBABCOCK POWER ENVIRONMENTALBABCOCK POWER ENVIRONMENTALWorcester, MAWorcester, MAEnvironmental Controls Conference – Pittsburgh, PAMay 16 – 18, 2006AgendaHybrid DefinedHybrid DefinedSNCR•TraditionalTraditional•Re-DesignedDesignedCompact SCR DesignCompact SCR Design•ToolsHybrid GoalsHybrid GoalsReal Life ExamplesReal Life ExamplesCostsHybrid NOHybrid NOxControl SystemControl System“CascadeCascade®”STEAM TURBINEAIRPREHEATER(S)ECONOMIZERBYPASSIN-DUCT SCRPULVERIZER(S)BOILERPRIMARY AIRCATALYSTCOALECONOMIZERLOW NOx BURNERSSNCRSNCRAIRUREASTORAGERedesignedRedesignedSNCRSystem with SCRSystem with SCR(using urea)(using urea)Higher NOHigher NOxReduction andReduction andUtilization thanUtilization thanSNCRNH3slip consumedslip consumedin SCRLow SO2to SO3Conversion RatesConversion Rates50-75% overall75% overallNOxreductionreductionLow capital costsLow capital costsTraditional Urea BasedTraditional Urea BasedSelectiveelectiveNon-CatalyticatalyticReduction (SNCR) of NOxeduction (SNCR) of NOxPrimaryCombustionNOxNOxOUT AUreaReagent1,700 -2,400 ° FN2/H2O/CO2(NH3Slip)Post CombustionPost CombustionGas Phase ReactionGas Phase ReactionFurnace is the ReactorFurnace is the ReactorTypical Combustion ProductsTypical Combustion ProductsProcess ParametersProcess Parameters•Time•Temperature and SpeciesTemperature and Species•DistributionDistributionWidely ApplicableWidely ApplicableHybrid1290 1470 1650 1830 2010 2190 2370Low Temperatures• Slow Droplet Evaporation• Slow Kinetics• Low OH Concentration• Ammonia SlipHigh Temperatures• Rapid Droplet Evaporation• Fast Kinetics• Increased OH Concentration• Urea Oxidation to NOxNOx ReductionAmmonia Slip“Right Side of the SlopeRight Side of the Slope”InjectionInjectionHybrid SNCR InjectionHybrid SNCR InjectionCFD ModelingCFD ModelingCold Flow ModelingCold Flow ModelingExpanded Duct SectionExpanded Duct SectionHybrid InHybrid In-DuctCold Flow Models and Flue Gas MixingCold Flow Models and Flue Gas Mixing•1:40 scale flow model1:40 scale flow modelBPI makes extensive use of flow modeling to guideBPI makes extensive use of flow modeling to guidedesigns and to ensure proper distributiondesigns and to ensure proper distributionDelta Wing MixerDelta Wing MixerTypical Hybrid Process GoalsTypical Hybrid Process GoalsMultiple Levels of SNCR Injection forMultiple Levels of SNCR Injection forLoad Following CapabilitiesLoad Following Capabilities50-75% Overall NOx Reduction, 275% Overall NOx Reduction, 2-5ppm NH3SlipOne Catalyst Layer at 1.3 m DepthOne Catalyst Layer at 1.3 m DepthSCR Inlet Temp = 650SCR Inlet Temp = 650°F Norm / 800F Norm / 800°FMaxNo Ammonia Injection GridNo Ammonia Injection GridEfficient Mixing to Achieve UniformEfficient Mixing to Achieve UniformDistributionDistributionSO2to SO3Conversion < 0.5 %Conversion < 0.5 %Fits within the Physical Space LimitationsFits within the Physical Space LimitationsCommercial Compact SCRand Hybrid (SNCR/SCR)ExamplesExample 1:Example 1:Compact InCompact In-Duct SCRDuct SCRExelon Handley Unit 3Exelon Handley Unit 3Turbo BoilerTurbo Boiler–GasFired94% NOx Removal94% NOx RemovalSCRIn-duct Reactorduct ReactorDelta Wing MixingDelta Wing MixingSystemHoneycomb CatalystHoneycomb CatalystBPI-Handley Test ResultsHandley Test ResultsFull load and low load NOx outletFull load and low load NOx outletconcentrations achieved at 0.02 andconcentrations achieved at 0.02 and0.01 lbs/Mmbtu respectively0.01 lbs/Mmbtu respectivelyNOx removal efficiencies of >94%NOx removal efficiencies of >94%Stack ammonia slip <3 ppm measuredStack ammonia slip <3 ppm measuredSCR system pressure loss as predictedSCR system pressure loss as predictedNH3/NOx ratios < 6% RMS, per designNH3/NOx ratios < 6% RMS, per designOptimization of unit in six operating daysOptimization of unit in six operating daysT-fired CE furnace: 1990 BL of 0.78fired CE furnace: 1990 BL of 0.78lb/MMBTUlb/MMBTUFurnace and convective pass injectionFurnace and convective pass injectionDesign Case:Design Case:42% reduction, 0.45 #/42% reduction, 0.45 #/MMBtu, <5ppmNH3slipOperational Case:Operational Case:35% reduction, 0.50 #/35% reduction, 0.50 #/MMBtu, <2ppmNH3slipLess than 10 % in convective passLess than 10 % in convective passHigh Ammonia Slip CaseHigh Ammonia Slip Case54% reduction, 0.36 #/54% reduction, 0.36 #/MMBtu,≈10ppmNH3slipShort-term testingterm testingIncreased chemical in convective passIncreased chemical in convective passExample 2: Fuel TechExample 2: Fuel TechSeward StationSeward Station-147MWg, CoalRequiredRequiredNH3ReductionReductionfrom 20from 20ppmto 2ppmRapid Flue Gas MixingRapid Flue Gas MixingMinimum SOMinimum SO3productionproduction(Ammonium Salts)(Ammonium Salts)Minimum pressure dropMinimum pressure dropWithstand coal fired gas streamWithstand coal fired gas streamSCR Expanded-duct Reactor DesignMaximum Reduction Achieved (>50%)Maximum Reduction Achieved (>50%)•System Tuned to 2, 10, or 20System Tuned to 2, 10, or 20ppmslip•Low-Load Operation at 2Load Operation at 2ppmSlip.Increased Chemical UtilizationIncreased Chemical UtilizationLess than 2Less than 2ppmammonia slip at SCR Outletammonia slip at SCR OutletHybrid SNCR/SCR Operated for more than 5Hybrid SNCR/SCR Operated for more than 5yearsHybrid SNCR/SCR PerformanceHybrid SNCR/SCR PerformanceFuelNOx ControlSystem NSRSNCRReductionSNCRUtilizationSCRReductionTotalReductionOverallUtilizationCoal Standard SNCR 1.19 37.0% 31.1% - 37.0% 31.1%Coal Hybrid 0.79 41.1% 59.2% 16.3% 50.7% 64.2%Coal Hybrid 1.15 36.9% 45.7% 54.2% 71.1% 61.8%Gas Hybrid 1.44 36.1% 38.6% 78.9% 86.5% 60.1%Gas Hybrid 1.56 39.0% 37.1% 83.6% 90.0% 57.7%•Ammonia Slip at 10Ammonia Slip at 10ppmor lessor lessExample 3; High Load (320MWe) HybridExample 3; High Load (320MWe) HybridResultsResultsExample 4; AESExample 4; AESGreenidgeGreenidgeApplicationApplicationHybrid SystemHybrid System115 MW Coal Fired Unit, 2.9% S115 MW Coal Fired Unit, 2.9% SBituminous coalBituminous coalTwo levels of SNCRTwo levels of SNCRIn-duct reactor; single layer of catalystduct reactor; single layer of catalystShort distance between economizer andShort distance between economizer andreactorreactorSNCR provides ~ 40% reductionSNCR provides ~ 40% reductionSCR provides balanceSCR provides balanceOverall system provides ~ 66%Overall system provides ~ 66%reductionreductionAll-In Capital Cost vs. NOx ReductionSCR$70-+$200?/KW+$200?/KW80-90%SNCR$10-$30/KW20-35%Hybrid$35-$80/KW50-75%Hybrid combines redesigned SNCR with SCRHybrid combines redesigned SNCR with SCRControl Flexibility: Operating vs. CapitalControl Flexibility: Operating vs. CapitalCostsHybrid can control slip and improveHybrid can control slip and improveutilizationutilization50% and 75% NOx Reduction with50% and 75% NOx Reduction withsignificantly reduced SCR retrofit capitalsignificantly reduced SCR retrofit capitalEach Unit Must Be Evaluated to DetermineEach Unit Must Be Evaluated to DetermineFeasibility for placement of an INFeasibility for placement of an IN-DUCT orDUCT orCOMPACT SCR.COMPACT SCR.2 Utility and 3 Industrial Hybrid Applications2 Utility and 3 Industrial Hybrid ApplicationsConclusionsContacts:Contacts:Mr. Dale PfaffMr. Dale PfaffFuel Tech, Inc.Fuel Tech, Inc.(630) 845(630) 845-4453dpfaff@fueltechnv.comdpfaff@fueltechnv.comMr. Rich AbramsMr. Rich AbramsBabcock Power EnvironmentalBabcock Power Environmental(508) 854(508) 854-1140rabrams@babcockpower.comrabrams@babcockpower.com