1Keys to Success: SCR Installationsat Dominions Brayton PointUnits 1 and 3Brian Wright–Dominion New EnglandClayton Erickson–Babcock PowerMatthew Phillipo–Babcock PowerElectric PowerMay 20082Agenda• Background Data• Scope of Supply• SCR Design Parameters – Performance• SCR Design Parameters – Site Issues• Startup and Commissioning• Performance Test Results3Background DataUnit 1:250 MWC.E., balanced draftboiler, firing low sulfurcompliant coal(0.98%)SCR Design:Reduce NOx by 90%Aqueous Ammonia(19% ammonia inwater)4Scope of SupplyUnit 1• One 2+1 layer reactor• Cormetech honeycomb – 7.0 mm pitch catalyst• Aqueous Ammonia System with direct ammoniainjection• Seven injectors per reactor – Delta wing mixingtechnology• Sonic Horns – 6 per layer• Economizer Bypass – for low load• Structural Steel and platforms• Construction• Catalyst and Air Heater Hoist System5Cross SectionR"0\!J.ITIONCONFERENCEUNIT1VIEWCROSSSVENVI6Background DataUnit 3:650 MWB & W opposed fired,balanced draft boiler,firing low sulfurcompliant coal (0.98%)SCR Design:Reduce NOx by 90%Aqueous ammoniareagent7SCR Reactor SystemUnit 3• Two identical 2+1 layer reactors• Cormetech honeycomb – 7.0 mm pitch catalyst• Aqueous Ammonia System with direct ammoniainjection• Four injectors per reactor – delta wing mixingtechnology• Sonic Horns – 6 per layer• Economizer Bypass – for low load• Structural Steel and Platforms• Construction• Catalyst and Air Heater Hoist System8Cross Section0BabcockPowerENVIRONMENTALSCRARRANGEMENTUNIT3BRAYTONPOINT9Design Parameters –Performance for Both UnitsParameterValueNOxRemoval Efficiency >90%Based on Inlet NOx = 0.40 lb/MBtuNH3Slip <2 ppm at end of catalyst life of16,000 hrsSO2to SO3conversion rate <1.0%, initial layers of catalystinstalledNH3/NOxDistribution 5% rmsFlue Gas Inlet TemperatureDistributionOver 100% surface: +/-27°F10SCR Design ParametersSite Issues• No loads to existing building steel on Unit 3• Extensive reinforcement of boiler steel on Unit 1• Short distance between Economizer Outlet andAirheater• Derrick crane on roof of Unit 3 for Unit 3 andfuture Unit 2 construction• Column locations required relocation of existingplant facilities (column in Men’s Room)11Site Issues - Design• No loads to existing building steel on Unit 3• Unit 1 existing internal steel work mods12Site Issues - Design• Short distancebetweenEconomizerOutlet andAirheater13Site Issues -Construction• Derrick crane on roof at Unit 314Site Issues -Construction• Main steel required office space relocation15Startup andCommissioning Unit 1• Requirement for fast startup andcommissioning• ScheduleDay 1: Initial calibration and baseline testingDay 2: Installation of NH3 supply system softwareDay 3: Mixing performance metDay 4: Performance confirmed and removalefficiency met, ready for acceptance testing,Unit in automatic16Performance – TestResults Unit 1-8οF Min+8οF Max-9οF Min+5οF Max+/-27οFοFTemperature VariationUpstream of the 1stcatalystlayer0.160.05<1.0%SO2to SO3Conversion Ratewith Initial Catalyst (totalconversion)0.080.08<2.0ppmvAmmonia Slip at 3% O22.92.355.0% rmsNH3/NOx variation95.091.1>90%NOxRemoval Efficiency RatePart Load(150 MWgross)Full Load(260 MWgross)GuaranteeParameter17Startup andCommissioning Unit 3• Requirement for fast startup andcommissioning• ScheduleDay 1: Initial calibration and instrument setupDay 2: Initial NH3 injection, tuned Reactor 31,mixing performance metDay 3: Tuned Reactor 32, mixing performance metDay 4: NOx removal performance met, ready foracceptance testing, Unit in automatic18Performance – TestResults Unit 3Full Load (640 Mwgross)-2οF Min+2οF Max-2οF Min+3οF Max+/-27οFοFTemperature VariationUpstream of the 1stcatalystlayer0.300.24<1.0%SO2to SO3Conversion Ratewith Initial Catalyst (totalconversion)0.090.07<2.0ppmvAmmonia Slip at 3% O20.81.05.0% rmsNH3/NOx variation90.791.5>90%NOxRemoval Efficiency RateReactor 32Reactor 31GuaranteeParameter19Conclusion• Difficult site conditions to overcome• Construction completed on time• All outage schedules met• Startup and commissioning within– 4 days Unit 1– 4 days Unit 3• All guarantees and schedules met• OTAG Season 2007, both units 0.04lbs/Mbtu –Long term performance