Steag GroupSteag’s Long-Term SCR CatalystOperating Experience and CostOperation &MaintenancePower Generationand District HeatingEngineering 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 GroupSteag‘sPower PlantsBexbach775 MWWeiher710 MWFenne500 MWHerne1,180 MW750 MWCOD 2012Walsum600 MW750 MWCOD 2010Lünen500 MWVoerde2,220 MWBergkamen750 MWGermanyTermopaipa,Columbia165 MWIskenderun,Turkey1.320 MWLeuna158 MWel + eq.Cologne-Godorf215 MWel + eq.InternationalMindanao,Philippines260 MWCOD 2006Steag’s Various SCR Arrangements:High-Duste.g. Voerde 4Low-Duste.g Walsum 7BoilerNH3SCRAir HeaterAirESPStackTail-Ende.g. Herne 3FGDESPAirAir HeaterStackSteamNH3SCRRegenerative GasGas Heat ExchangerSteamReheaterBoilerESPAirAir HeaterSteamNH3SCRRegenerativeGas-Gas HeatExchangerSteamReheaterBoilerESPFGDStackFGDSteag‘sSCR ArrangementsHerne 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 HeatHerneCogeneration PlantHerne Unit 3Tail-End SCR0 20000 40000 60000 80000 100000 120000 140000SCR operating hours

DeNOx potential P NH 3 -slipSCR Commissioning in 1988:- 1 1⁄2 layers of honeycomb catalyst (550 mm length).- 2 1⁄2 spare 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 3Herne Unit 4High-Dust SCR0 20000 40000 60000 80000 100000 120000SCR operation hours

DeNOx potential P NH 3 -slipSCR Commissioning in 1989:- 2 layers of honeycomb catalyst (installed in layers 1 and 3).- 2 spare 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.Herne 44.24.1HHH (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 ofnew platelayer F.Removal oflayer B toregeneration,addition ofnew platelayer G.Removal oflayer C todisposal,addition ofnew platelayer H.Removal oflayer D toregeneration,addition ofnew platelayer I.Removal oflayer E toregeneration,addition ofregeneratedplate layer J.Herne Unit 4High-Dust SCRHerne 4 Catalyst Exchange LogbookComments and Costs:-Honeycomb was found to be unable to withstand the erosionfrom the high ash waste coal burned.-Initial fill of 4 half 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 catalyst replacement 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 half layers andthe removal of 5 half layerswas found to be 11 x 10% ofinitial catalyst cost = 110%.-Total catalyst replacement costs = 347% or 3.15% of initialcost per 1,000 operating hours.-2-Herne Unit 4High-Dust SCRVoerde 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.- Wet CaCO3forced oxidationFGD system producing wallboard quality gypsum, noflue gas reheat, wet stack.- Operator: Steag- Owner: Steag 75%RWE 25%- Power Purchaser: RWEVoerdePower StationVoerde Unit 4High-Dust SCR0 20000 40000 60000 80000 100000 120000SCR operating hours

DeNOx potential P NH 3 -slipSCR Commissioning in 1989:- 3 layers of honeycomb catalyst (installed in layers 1, 2, and 3).- 1 spare 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 44.24.1F (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 and newplate 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 ofnew honeycomb layer F.Removal oflayer A toregeneration,addition ofregeneratedlayer B.Voerde Unit 4High-Dust SCRE (pl)Voerde 4 Catalyst Exchange LogbookVoerde Unit 4High-Dust SCRComments and Costs:-Initial fill of 3 honeycomb layers was set to represent 100%of the initial cost.-Total catalyst exchange cost during the last 107,000 SCRoperating hours was found to be:-For catalyst replacement 5 (3 initial, 2 half plate 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 normal catalyst deactivation.Walsum Cogeneration Plant:-Unit 7 - 150 MW PC 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: RWEEnBWWalsumCogeneration PlantWalsum Unit 9High-Dust SCR0 20000 40000 60000 80000 100000 120000 140000 160000SCR operation hours

DeNOx potential P NH 3 -slipSCR Commissioning in 1988:- 4 half layers of plate catalyst (installed in layers 2, 3 and 4)- 2 spare 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 9DWalsum Unit 9High-Dust SCRKKK (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 ofnew layer I.Removal oflayer H toregeneration,addition ofnew layer J.Removal oflayers C andD to disposal,addition ofregeneratedlayer H andnew layer K .Removal oflayers A andB to disposal,no additiondue to excessinstalledDeNOxpotential.Addition ofregeneratedlayer L fromVoerde Unit 4.Walsum 9 CatalystExchange LogbookWalsum Unit 9High-Dust SCRComments and Costs:-Initial fill of 4 half 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 catalyst replacement 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 initial cost).-For field labor cost for the installation of 7 half layers andthe removal of 5 half layerswas found to be 12 x 10% ofinitial catalyst cost = 120%.-Total catalyst replacement costs = 345% or 2.95% of initialcost per 1,000 operating hours.Weiher Power Station- 710 MW PC wall-fired, drybottom boiler.- Saar regional bituminouscoal, ash < 15%, sulfur< 1.5%.- High-dust SCR system,honeycomb catalyst.- Wet CaCO3forced oxidationFGD system producing wallboard quality gypsum, noreheat, flue gas dischargevia cooling tower- Operator: Steag- Owner: Steag- Power Purchaser: RWEWeiherPower StationWeiher Unit 3High-Dust SCRWeiher Power Station Unit 3- 10,000 20,000 30,000 40,000 50,000 60,000 70,000 80,000SCR operating hours

DeNOx potential PWeiher 3SCR Commissioning in 1990:- 3 layers of honeycomb catalyst (installed in layers 1, 2, and 3).- 1 spare 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 fly ash (similar to PRB).Weiher Unit 3High-Dust SCR4.2FFF (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 ofnew honeycomb layer E.Removal oflayer D toregeneration,addition ofnew honeycomb layer F.Removal oflayer C toregeneration,addition ofregeneratedlayer D.Weiher 3 CatalystExchange LogbookWeiher Unit 3High-Dust SCR-2-Comments and Costs:-Initial fill of 3 honeycomb layers was set to represent 100%of the initial cost.-Total catalyst exchange cost during the last 72,000 SCRoperating hours was found to be:-For catalyst replacement 5 (3initial and 2 replacement)new layers (= 167% of initial cost) plus 6 regeneratedreplacement layers (= 67% of initial cost).-For field labor cost for the removal of 8 and installationof 9 layers was found to be17 x 10% of initial catalystcost = 170%.-Total catalyst replacement costs = 404% or 5.61% of initialcost per 1,000 operating hours.-Note that after the switchto Bexbach coal the catalyst‘sdeactivation rate increased significantly due to rapidformations of strong surface blinding layers.Leuna Refinery Cogeneration Plant-Units 1 – 3 combined:- 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 PlantLeunaCogeneration PlantLeuna Units 1, 2 and 3- 10,000 20,000 30,000 40,000 50,000 60,000 70,000SCR operating hours

DeNOx potential PP U1P U2P U3SCR Commissioning in 1996/97:- 2 layers of plate catalyst (installed in layers 1 and 2).- 1 spare layer (layer 3).Deactivation highly dependent on fuel composition. Fuelcomposition highly variable. Honeycomb catalyst used once,deactivated very rapidly. Sincethen only plate catalyst used.Leuna 1, 2 and 3LeunaCogeneration PlantG used elsewhereA, DA, FHEBA, BAFCout for regen.CCC (reg)HHHHH (new)FFEEE (reg)CCCCC (reg)EEU3HH (reg)FFFFF (reg)DDDII (new)AAA (reg)GGGG (new)CU2F (reg)DDDDD (reg)BBBBBBBB (reg)EEEE (reg)AAU167,00062,25656,19854,57040,47037,77233,99432,81330,1780hoursLeuna 1, 2 and 3 Catalyst Exchange LogbookRemoval oflayer C toregeneration,purchase ofa new honeycomb layerG.Removal oflayers A, E, Ftoregeneration,purchase of anew platelayer H,addition ofregeneratedlayers E, C.Removal oflayer D toregeneration,addition ofregeneratedlayer F.Removal oflayer G,addition ofregeneratedlayer A.Removal of layer A, F toregeneration, additionof new plate layer 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:-Initial fill of 6 plate layers (2per unit) was set to represent100% of the initial cost.-Total catalyst exchange cost during the last 210,000 SCRoperating hours for all 3 units was found to be:-For catalyst replacement 8 (6initial and 3 replacement)new layers (= 133% of initialcost) plus 10 regeneratedreplacement layers (= 83% of initial cost).-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.Summary andConclusionsSummary and Conclusions:Specific catalyst cost vary highly depending on:-The SCR arrangement – tail-end approximately only 1/3 ofhigh-dust despite extensive use of regeneration.-The fuel – high ash (i.e. waste coal) versus high CaO (i.e.PRB) versus high vanadium (i.e. Pet coke).Specific Catalyst Cost0123456Herne 3 Herne 4 Voerde 4 Walsum 9 Weiher 3 Leuna 1-3

% per 1,000 hSummary andConclusionsSummary 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.SteagSteag‘s SCRexperience:~ 2 million hoursof SCR operation?Questions?