Taconite BART AnalysisNOx ControlAvailable and Applicable ReviewRevised: August 23, 2006Step 1 Step 2This table is part of the Taconite BART Report andshould not bedistributed without the full text of the report sothat the information isnot taken out of context.

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1NOxPollution ControlTechnology Is this a generally available control technology? Is the control technology available to indurating furnaces? Is the control technology applicable to this specific source? Is it technically feasible for this source?CommentsBasic PrincipleCombustion Controls1 Overfire Air (OFA) Y N --- ---NOx formation front is not stationary inan indurating furnaceCombustion air is separated into primary and secondary flow sections toachieve complete burnout and to encourage the formation of N2ratherthan NOx2External Flue GasRecirculation (EFGR)Y Y N ---Mixes flue gas with combustion air which reduces oxygen content andtherefore reduces flame temperature3 Low-NOx Burners Y YY(preheatburners)Y(preheatburners)Higher control efficiency at the burner,but the listed control efficiency is forthe entire furnace.Burners are designed to reduce NOx formation through restriction ofoxygen, flame temperature, and/or residence time4Induced Flue GasRecirculation BurnersY Y N ---Need to be upfired. Need convectiveloop to get gas recirculatedDraws flue gas to dilute the fuel in order to reduce the flame temperature5 Low Excess Air Y N --- ---Need high O2for process requirementsand product qualityReduces oxygen content in flue gas and reduces flame temperature6Burners out of Service(BOOS)Y N --- ---Need capacity of all burners for worstcase scenarioShut off the fuel flow from one burner or more to create fuel rich and fuellean zones7 Fuel Biasing Y N --- --- Power plant technologyCombustion is staged by diverting fuel from the upper level burners to thelower ones or from the center to the side burners to create fuel-rich andfuel-lean zones8 Reburning Y N --- ---Kiln configuration not correct for thistechnology.Part of the total fuel heat input is injected intothe furnace in a regionabove the primary (main burners) flames to create areducing atmosphere(re-burn zone), where hydrocarbon radicals react with NOx to produceelemental nitrogen9 Load Reduction N --- --- ---Power plant technology -productdemand side solutionThis is a strategy to reduce load on a power plantby reducing theelectrical demand throught efficiency projects.10 Energy Efficiency Projects Y YY(for largeprojects likeheat-recoup)Y(for largeprojects likeheat-recoup)decrease amount of fuel required to make an acceptable product11 Coal Drying Y N --- --- Applies only to facilities that burn coalDry coal will increase the as-burned BTU value, andtherefore less fuel isrequired to be burned. Specific energy efficiencyproject12Coal Addition to Pellets withLow Excess Air in theInduration FurnaceN --- --- --- Check on status of research Reduce flame temperature and energy requirementsTaconite BART AnalysisNOx ControlAvailable and Applicable ReviewRevised: August 23, 2006Step 1 Step 2This table is part of the Taconite BART Report andshould not bedistributed without the full text of the report sothat the information isnot taken out of context.

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1NOxPollution ControlTechnology Is this a generally available control technology? Is the control technology available to indurating furnaces? Is the control technology applicable to this specific source? Is it technically feasible for this source?CommentsBasic Principle13 Ported Kilns Y YY(grate-kilnsonly)N(Metso saysno NOximprovement)Applicable to grate kilns.Provides additional oxygen for pellet oxidation which reduces the overallenergy use of the kiln14 Combustion Zone Cooling Y N --- --- Boiler technologyCooling of the primary flame zone by heat transferto surroundingsurfaces15 Alternate Fuels Y YY(for furnacescapable ofmultiple fuels)Y(not requiredby BART)Requires case by case analysis.Typically, facilities experience lowerNOx when burning solid fuels.Lower combustion temps with solid fuels vs gas. May also reduce fuelNOx by using a fuel with less nitrogen.16Oxygen EnhancedCombustionN --- --- --- Research level A small fraction of the combustion air is replaced with oxygen.17 Preheat Combustion N --- --- --- Research levelPulverized coal preheated and volatiles and fuel-bound nitrogencompounds are released in a controlled reducing atmosphere where thenitrogen compounds are reduced to N2.18 ROFA-ROTAMIX Y N --- ---Can't achieve correct temperaturewindow (1400-1800F). Too hot in kilntoo cold in reheatCombination of OFA and SCR. Wall-fired or tangentially-fired furnace thatutilizes high velocity overfire air. Additional NOxreductions are achievedwith ammonia injection (Rotamix)19 NOx CEMS Y N --- ---Optimization of combustion20 Parametric Monitoring Y N --- ---Optimization of combustion38Catalyst Injection(EPS Technologies)N --- --- --- Research LevelA combustion catalyst is directly injected into theair intake stream anddelivered to the combustion site, initiating chemical reactions that changethe dynamics of the flame.Post Combustion Controls21Non-Selective CatalyticReduction (NSCR)Y N --- ---For clean services. Too much stuff influe gas would poison catalystUnder near stoichiometric conditions, in the presence of a catalyst, NOx isreduced by CO, resulting in nitrogen (N2) and carbon dioxide (CO2).22Low Temperature Oxidation(LTO) - Tri-NOx®Y N --- --- Used for higher flue gas concentrationsUtilizes an oxidizing agent such as ozone to oxidize various pollutantsincluding NOxTaconite BART AnalysisNOx ControlAvailable and Applicable ReviewRevised: August 23, 2006Step 1 Step 2This table is part of the Taconite BART Report andshould not bedistributed without the full text of the report sothat the information isnot taken out of context.

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1NOxPollution ControlTechnology Is this a generally available control technology? Is the control technology available to indurating furnaces? Is the control technology applicable to this specific source? Is it technically feasible for this source?CommentsBasic Principle23Low Temperature Oxidation(LTO) - LoTOxY N --- ---Has been included as an "applicableand available" technology in recentBACT analyses from multiple facilities.Utilizes an oxidizing agent such as ozone to oxidize various pollutantsincluding NOx24Selective CatalyticReduction (SCR)Y Y Y YNeed to inject at appropriatetemperature (reheat will be required).Applicable on clean side only.Although this hasn't beendemonstrated on an induratingfurnace, the stream characteristicsappear to make this technologyfeasible.Ammonia (NH3) is injected into the flue gas stream in the presence of acatalyst to convert NOx into N2and water25 Regenerative SCR Y N --- --- Clean side only26Selective Non-CatalyticReduction (SNCR)Y N --- ---Can't achieve correct temperaturewindow (1400-1800F). Too hot in kilntoo cold in reheatUrea or ammonia-based chemicals are injected into the flue gas stream toconvert NO to molecular nitrogen, N2, and water27 Adsorption N --- --- --- Still in research stages. Useof char (activated carbon) to adsorb oxides of nitrogen28 Absorption Y N --- --- Similar to TriNOxUse of water, hydroxide and carbonate solutions, sulfuric acid, organicsolutions, molten alkali carbonates, or hydroxidesto absorb oxides ofnitrogen.29 Oxidizer Y N --- --- Redundant to regenerative SCRGas stream is sent through the regenerative, recuperative, catalytic ordirect fired oxidizer where pollutants are heated to a combustion point anddestroyed.30 SNOX N --- --- --- Early commercial development stageCatalytic reduction of NOx in the presence of ammonia (NH3), followed bycatalytic oxidation of SO2to SO3. The exit gas from the SO3converterpasses through a novel glass-tube condenser in which the SO3ishydrated to H2SO4vapor and then condensed to a concentrated liquidsulfuric acid (H2SO4).31 SOx-NOx-Rox-Box N --- --- ---Technology has not beendemonstratedDry sorbent injection upstream of the baghouse forremoval of SOx andammonia injection upstream of a zeolitic selectivecatalytic reduction(SCR) catalyst incorporated in the baghouse to reduce NOx emissions.Taconite BART AnalysisNOx ControlAvailable and Applicable ReviewRevised: August 23, 2006Step 1 Step 2This table is part of the Taconite BART Report andshould not bedistributed without the full text of the report sothat the information isnot taken out of context.

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1NOxPollution ControlTechnology Is this a generally available control technology? Is the control technology available to indurating furnaces? Is the control technology applicable to this specific source? Is it technically feasible for this source?CommentsBasic Principle32 Electron (E-Beam) Process N --- --- ---No operating commercial applicationson coalElectron beam irradiation in the presence of ammonia to initiate chemicalconversion of sulfur and nitrogen oxides into components which can beeasily collected by conventional methods such as anESP or baghouse.33 Electrocatalytic Oxidation N --- --- ---Similar to cold plasma. Will keepwatch for availability of this technologyUtilizes a reactor in which SO2, NOx, and mercury are oxidized to nitrogendioxide (NO2), sulfuric acid, and mercuric oxide respectively using nonthermal plasma.On recent project, the vender was doing final trials on full-scaleapplications.34 NOXSO N --- --- ---Commercial version of adsorption.Limited experience (proof-of-concepttests).Uses a regenerable sorbent to simultaneously adsorbSO2and NOx fromflue gas from coal-fired utility and industrial boilers. In the process, theSO2is converted to a saleable sulfur by-product (liquid SO2, elementalsulfur, or sulfuric acid) and the NOx is convertedto nitrogen and oxygen.35 Copper-Oxide N --- --- ---Absorption and SCR. Experiencelimited to pilot scale.SO2in the flue gas reacts with copper oxide, supported on small spheresof alumina, to form copper sulfate. Ammonia is injected into the flue gasbefore the absorption reactor and a selective catalytic reduction-typereaction occurs that reduces the nitric oxides in the flue gas. In theregeneration step, the copper sulfate is reduced ina regenerator with areducing agent, such as natural gas, producing a concentrated stream ofSO2.36 Cold Plasma N --- --- --- Research Level37 Biofilters Y N --- --- Not applicable to furnaces.Gas stream is passed through a filter medium of soil and microbes.Pollutants are adsorbed and degraded by microbial metabolism formingthe products carbon dioxide and water.38 Pahlman Process N --- --- --- Research LevelGas stream is passed through a filter baghouse in which speciallydeveloped, small-particle, high-surface area metaloxide sorbent havebeen deployed. Pollutants are removed from the gases by adsorption.1) This number is for reference only. It does notin any way rank the control technologies.2) a) Air Pollution: Its Origin And Control. Wark,Kenneth; Warner, Cecil F.; and Davis, Wayne T. 1998. Addison Wesley Longman, Inc.2) b) US EPA Basic Concepts in Environmental Science, Module 6, http://www.epa.gov/eogapti1/module6/index.htmTaconite BART AnalysisNOx ControlAvailable and Applicable ReviewRevised: August 23, 2006Step 1 Step 2This table is part of the Taconite BART Report andshould not bedistributed without the full text of the report sothat the information isnot taken out of context.

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1NOxPollution ControlTechnology Is this a generally available control technology? Is the control technology available to indurating furnaces? Is the control technology applicable to this specific source? Is it technically feasible for this source?CommentsBasic Principle2) c) New and Emerging Environmental Technologies,http://neet.rti.org/2) d) ND BART Reports