Steag GroupSteag’s Long-Term CatalystOperating Experience and Cost2005 Workshop on Selective Catalytic ReductionSponsored by EPRINovember 15 –17, 2005Louisville, KentuckySteag GroupOperation &MaintenancePower Generationand DistrictHeatingEngineering andIT SolutionsSteag Group Facts:•Steag is a wholly owned subsidiary of RAG, Europe‘slargest bituminous coal mining company.•Steag is Europe‘s second largest power generator frombituminous coal.•Steag owns and operates morethan 10,000 MW of electricand steam generating capacity.•In 2004 Steag:•had more than 5,000 employees worldwide.•had revenues of more than $ 6 billion worldwide.•operated 28 electric generating units with 24 SCRs.•had 3 electric generating units under construction.•operated 9 waste-to-energy plants (all with SCRs).•operated 20 electric generating units for third parties.•For more info go towww.steag.com.Steag‘sPower PlantsHerne1,180 MW750 MWCOD 2012Fenne500 MWGermanyCologne-Godorf215 MWel +eq.Bergkamen750 MWBexbach775 MWVoerde2,220 MWLünen500 MWWalsum600 MW750 MWCOD 2010Leuna158 MWel +eq.Weiher710 MWTermopaipa,Columbia165 MWMindanao,Philippines260 MWCOD 2005InternationalIskenderun,Turkey1.320 MWSteag‘sSCR ArrangementsSteag’s Various SCR Arrangements:High-Duste.g. Voerde 4Low-Duste.gWalsum 7BoilerNH3SCRAir HeaterAirESPStackTail-Ende.g. Herne 3FGDESPAirAir HeaterStackSteamNH3SCRRegenerative GasGas Heat ExchangerSteamReheaterBoilerESPAirAir HeaterSteamNH3SCRRegenerativeGas-Gas HeatExchangerSteamReheaterBoilerESPFGDStackFGDHerneCogeneration PlantHerne Cogeneration Plant:-Units 1 & 2-150 MW electricity each.-Unit 3-300 MW electricity.-Both PC U-fired, wet bottom boilers.-Tail-end SCRs, honeycomb catalyst.-Unit 4-385 MW electricity.-550 MW district heat.-PC wall-fired, dry bottom boiler.-High-dust SCR system, plate catalyst.-Bone meal, waste bituminous coal,ash > 40%, sulfur < 1.5%.-Wet CaO/CaCO3forced oxidationFGD system producing wall boardquality gypsum, flue gas reheat viarotary gas/gas heat exchanger.-Operator: Steag-Owner: Steag-Power Purchaser: RWESteag District HeatHerne Unit 3Tail-End SCR020000400006000080000100000120000140000SCR operating hours

DeNOx potential P NH 3 -slipHerne 3SCR Commissioning in 1988:-11⁄2layers of honeycomb catalyst(550 mm length).-21⁄2spare layers (still empty).Operation during the past 110,000 operating hours has beenextremely uneventful. No catalystaddition is planned until 2007.Total catalyst replacement cost = 0.9% per 1,000 hours.Herne Unit 4High-Dust SCR020000400006000080000100000120000SCR operation hours

DeNOx potential P NH 3 -slipHerne 4SCR Commissioning in 1989:-2layers of honeycomb catalyst (installed in layers 1 and 3).-2spare layers (layers 2 and 4).Severe erosion problems resulting from waste coal led to thereplacement of both honeycomb layers in 1991. Since then onlyplate catalyst has been used. Operating hours were reset to 0.4.24.1HHH (new)DDDD3.2II (new)DCCCCHC 23.1FFFFF (new)2.2GGGG (new)BE (new)2.1BB1.2J (reg)EEEEAHC 11.1layer96,00075,80060,00045,00031,00016,5000 (plate)Initial(hc)ARemovalof honeycombs;additionof platelayers.Additionof newhalf platelayer E.Removal oflayer A toregeneration,addition ofnewplatelayer F.Removal oflayer B toregeneration,addition ofnewplatelayer G.Removal oflayer C todisposal,addition ofnewplatelayer H.Removal oflayer D toregeneration,addition ofnewplatelayer I.Removal oflayer E toregeneration,addition ofregeneratedplate layer J.Herne Unit 4High-Dust SCRHerne 4 Catalyst ExchangeLogbookComments and Costs:-Honeycomb was found to be unable to withstand the erosionfrom the high ash waste coal burned.-Initial fillof 4half plate layers was set to represent 100% ofthe initial cost.-Total catalyst exchange cost during the last 110,000 SCRoperating hours was found to be:-For catalystreplacement 9 (4initial and 5 replacement)new half layers (= 225% of initial cost) plus 1 regeneratedreplacement layer (= 12% of initial cost).-For field labor cost for the installation of 6 halflayers andthe removal of 5 half layerswas found to be 11 x 10% ofinitialcatalyst cost = 110%.-Total catalyst replacement costs =347% or 3.15% of initialcost per 1,000 operating hours.-2-Herne Unit 4High-Dust SCRVoerdePower StationVoerde Power Station:-Units 1 & 2 –both 350 MW PC U-fired, wet bottom boilers.-Waste bituminous coal, ash > 40%, sulfur < 1.5%.-Both tail-end SCR systems, honeycomb catalyst.-Units 3 & 4 –both 760 MW PCwall-fired, dry bottom boilers.-World market bituminouscoal, ash < 15%,sulfur < 1.5%.-Both high-dust SCRsystems, honeycomb andplate catalyst mixed.- WetCaCO3forced oxidationFGD system producing wallboard quality gypsum, noflue gas reheat, wet stack.-Operator:Steag-Owner: Steag75%RWE 25%-Power Purchaser: RWEVoerde Unit 4High-Dust SCR020000400006000080000100000120000SCR operating hours

DeNOx potential P NH 3 -slipVoerde 4SCR Commissioning in 1989:-3layers of honeycomb catalyst (installed in layers 1, 2, and 3).-1spare layer (layer 4).LPA catalyst pluggage problems appeared unexpectedly in1996. After installation of Steag’s LPA screens, no furtherproblems with LPA intrusion into the SCR reactor occurred.Voerde Unit 4High-Dust SCRVoerde 4 CatalystExchange Logbook4.24.1F (new)B3.2FB (reg)CCC (hc)3.1B (reg)AA2.2AA (reg)BB (hc)2.1EE1.2CCC (reg)DD (pl)A (hc)1.1layer107,00093,00075,00049,00048,00040,000Initial0DRemoval of layer A(plugged) toregeneration, additionof regenerated platesfrom Herne 4 andnewplate layers D and E.Removal oflayer B toregeneration,addition ofregeneratedlayer A.Removal oflayer C toregeneration,addition ofregeneratedlayer B.Removal oflayers D, E toregeneration,addition ofregeneratedlayer C.Removal oflayer B toregeneration,addition ofnewhoneycomb layer F.Removal oflayer A toregeneration,addition ofregeneratedlayer B.E (pl)Voerde Unit 4High-Dust SCRComments and Costs:-Initial fillof 3honeycomb layers was set to represent 100%of the initialcost.-Total catalyst exchange cost during the last 107,000 SCRoperating hours was found to be:-For catalystreplacement 5 (3 initial,2 halfplate and 1honeycomb replacement) new layers (= 167% of initialcost) plus 4 regeneratedhoneycomb replacement layers(=66% of initial cost).-For field labor cost for the removal and installation of 6layers was found to be 6 x 10%of initial catalyst cost =60%.-Total catalyst replacement costs =293% or 2.74% of initialcost per 1,000 operating hours.-Note that 2 catalyst exchanges were caused by LPApluggage and not by normalcatalyst deactivation.WalsumCogeneration PlantWalsum Cogeneration Plant:-Unit 7 -150 MWPC U-fired, wet bottom boiler.-Low dust SCR system,honeycomb catalyst.-Unit 9 -450 MW PC tangentially-fired, dry bottom boiler.-High dust SCR system, plate catalyst.-Bituminous waste coal,ash > 40%, sulfur < 1.5%plus sewage sludge.-Wet CaO/CaCO3forcedoxidation FGD systemsproducing wall board.quality gypsum, flue gasreheat via gas/gas reheater.-Operator: Steag-Owner: Steag-Power Purchaser: RWEEnBWWalsum Unit 9High-Dust SCR020000400006000080000100000120000140000160000SCR operation hours

DeNOx potential P NH 3 -slipWalsum 9SCR Commissioning in 1988:-4half layers of plate catalyst(installed in layers 2, 3 and 4)-2spare half layers (layer 1).Severe erosion resulting fromthe very high ash content (30 –40%) of the waste coal burneddemanded the use of only platecatalyst from initial commissioning on. Half layers used only!Walsum Unit 9High-Dust SCRWalsum 9 CatalystExchange LogbookDKKK (new)DDDD3.2HHH (reg)CCCCC3.1BBBBBB2.2L (reg)AAAAAA2.1JJJJ (new)HH(used)G(used)1.2IIIII (new)1.1layer117,000111,000100,00096,70083,50051,50031,700Initial0GAdditionof usedlayer GfromWalsumUnit 7.Additionof usedlayer HfromWalsumUnit 7.Removal oflayer G toregeneration,addition ofnewlayer I.Removal oflayer H toregeneration,addition ofnewlayer J.Removal oflayers C andD to disposal,addition ofregeneratedlayer H andnewlayer K .Removal oflayers A andB to disposal,no additiondue toexcessinstalledDeNOxpotential.Addition ofregeneratedlayer L fromVoerde Unit 4.Walsum Unit 9High-Dust SCRComments and Costs:-Initial fillof 4half plate layers was set to represent 100% ofthe initial cost.-Total catalyst exchange cost during the last 117,000 SCRoperating hours was found to be:-For catalystreplacement 7 (4initial and 3 replacement)new half layers (= 175% of initial cost) plus 2 usedadditional layers (= 25% ofinitial cost) plus 2regenerated replacement layer(= 25% of initialcost).-For field labor cost for the installation of 7 halflayers andthe removal of 5 half layerswas found to be 12 x 10% ofinitialcatalyst cost = 120%.-Total catalyst replacement costs =345% or 2.95% of initialcost per 1,000 operating hours.WeiherPower StationWeiher Power Station-710 MW PC wall-fired, drybottom boiler.-Saar regional bituminouscoal, ash < 15%, sulfur< 1.5%.-High-dust SCR system,honeycomb catalyst.- WetCaCO3forced oxidationFGD system producing wallboard quality gypsum, noreheat, flue gas dischargevia cooling tower-Operator: Steag-Owner: Steag-Power Purchaser: RWEWeiher Unit 3High-Dust SCRWeiherPowerStationUnit3-10,00020,00030,00040,00050,00060,00070,00080,000SCRoperating hours

D e N O x p o t en t i al PWeiher 3SCR Commissioning in 1990:-3layers of honeycomb catalyst (installed in layers 1, 2, and 3).-1spare layer (layer 4).Coal switch from Weiher coalto Bexbach coal (both Saarregional mines) caused formation of strong surface blindinglayers due to high CaO content inthe flyash (similar to PRB).Weiher Unit 3High-Dust SCRWeiher 3 CatalystExchange Logbook4.2FFF (new)DD (reg)DDD (new)4.13.2EEEE (new)AAA (reg)C3.1B2.2DD (reg)CCCC (reg)B2.11.2A (reg)BBBB (reg)A1.1layer72,00061,52650,56045,85342,62736,68132,86826,631Additionof newhoneycomblayer D.Removal oflayers A, C toregeneration,addition ofregeneratedlayer A.Removal oflayer B toregeneration,addition ofregeneratedlayer C.Addition ofregeneratedlayer B,regenerationof layer D.Removal oflayer A toregeneration,addition ofnewhoneycomblayer E.Removal oflayer D toregeneration,addition ofnewhoneycomb layer F.Removal oflayer C toregeneration,addition ofregeneratedlayer D.Weiher Unit 3High-Dust SCR-2-Comments and Costs:-Initial fillof 3honeycomb layers was set to represent 100%of the initialcost.-Total catalyst exchange cost during the last 72,000 SCRoperating hours was found to be:-For catalystreplacement 5 (3initial and 2 replacement)new layers (= 167% of initial cost) plus 6 regeneratedreplacement layers (= 67% of initialcost).-For field labor cost for the removal of 8 and installationof 9layers was found to be17 x10% of initial catalystcost = 170%.-Total catalyst replacement costs =404% or 5.61% of initialcost per 1,000 operating hours.-Note that after the switch toBexbach coal the catalyst‘sdeactivation rate increased significantly due to rapidformations of strong surface blinding layers.LeunaCogeneration PlantLeuna Refinery Cogeneration Plant-Units 1 –3combined:-178 MW electricity (total).-208 MW process steam (total).-All liquid/slurry wall-fired, dry bottom boilers.-Pet coke and refineryresidues, ash < 5%,sulfur >3.5%.-High-dust SCR systems,plate catalyst.-Wet lime forced oxidationFGD systems producingwall board qualitygypsum, flue gas reheatvia steam coil.-Operator:Steag-Owner: Steag-Power Purchaser: TotalFina ELF RefineryLeunaCogeneration PlantLeuna Units 1,2 and3-10,00020,00030,00040,00050,00060,00070,000SCR operating hours

De NO x p o t e n t i a l PP U1P U2P U3SCR Commissioning in 1996/97:-2layers of plate catalyst (installed in layers 1 and 2).-1spare layer (layer 3).Deactivation highly dependent on fuel composition. Fuelcomposition highlyvariable.Honeycomb catalyst used once,deactivated very rapidly. Sincethen only plate catalyst used.Leuna 1, 2 and3LeunaCogeneration PlantLeuna1, 2 and 3 Catalyst ExchangeLogbookhours030,178 32,81333,99437,772 40,47054,57056,198 62,256 67,000AAE (reg)EEEB (reg)BBBBBBBD (reg)DDDDF (reg)CG (new)GGGA (reg)AAI (new)IDDDF (reg)FFFFH (reg)HEEC (reg)CCCCE (reg)EEFFH (new)HHHHC (reg)CCout for regen.CFAA, BBEHA, FA, DG used elsewhereU3U2U1Removal oflayer C toregeneration,purchase ofa newhoneycomb layerG.Removal oflayers A, E, Ftoregeneration,purchase ofanewplatelayer H,addition ofregeneratedlayers E, C.Removal oflayer D toregeneration,addition ofregeneratedlayer F.Removal oflayer G,addition ofregeneratedlayer A.Removal of layer A, Ftoregeneration, additionof newplatelayer I andregenerated layer H.Removal of layer C, H toregeneration, additionregenerated layers C, E.Removal of layer Dto regeneration,addition ofregenerated layer F.Removal oflayer G,addition ofregeneratedlayer A.LeunaCogeneration PlantComments and Costs:-Initialfill of6 plate layers (2per unit) was set to represent100% of the initialcost.-Total catalyst exchange cost during the last 210,000 SCRoperating hours for all 3units was found to be:-For catalystreplacement 8 (6initial and 3 replacement)new layers (= 133% of initialcost) plus 10 regeneratedreplacement layers (= 83% of initialcost).-For field labor cost for the removal of 13 and installationof 13 layers was found to be26 x 10% of initial catalystcost = 260%.-Total catalyst replacement for costs all 3 units = 476% or2.27% of initial cost per 1,000 operating hours.-Note that honeycomb catalystwas found to deactivate muchmore rapidly than plate catalyst. It was replaced againstplate catalyst, regenerated and used elsewhere.SummaryandConclusionsSummary and Conclusions:Specific CatalystCost0123456Herne 3Herne 4Voerde 4Walsum9Weiher3Leuna 1-3

% pe r 1 , 0 0 0 hSpecific catalyst cost vary highly depending on:-The SCR arrangement –tail-end approximately only 1/3 ofhigh-dust despiteextensive use of regeneration.-The fuel –high ash (i.e.waste coal) versus high CaO (i.e.PRB) versus high vanadium (i.e. Pet coke).SummaryandConclusionsSummary and Conclusions:-Catalyst is viewed and treated by Steag as a commodity,however not all catalyst types are suitable for allapplications.-Each type of catalyst has its distinct advantages anddisadvantages. The selection of the best catalyst typerequires an economic evaluation on a case by case basis.-The use of new versus regenerated catalyst depends solelyon market conditions and prices. The prices of regeneratedcatalyst varied between 25% and 65% of new catalyst,depending on the price of new catalyst and the type ofregeneration process used and required.-Steag found no difference in longevity or deactivation ratebetween regenerated and new catalyst. However, theSO2/SO3conversion rate may differ significantly, dependingon the regeneration process used.Steag?Questions?Steag‘s SCRexperience:~ 2 million hoursof SCR operation