Taconite BART AnalysisSO2 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.

Reference No.

1SO2Pollution 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 Principle1Wet Scrubbing (HighEfficiency)Y Y Y YAbsorption and reaction using an alkaline reagent to produce a solid compound2Wet Scrubbing (LowEfficiency)Y Y Y YAbsorption and reaction using an alkaline reagent to produce a solid compound3Wet Walled ElectrostaticPrecipitator (WWESP)Y Y Y YSuspended particles are separated from the flue gasstream, attracted to plates, andcollected in hoppers4 Dry sorbent injectionY Y Y NPulverized lime or limestone is directly injected into the duct upstream of the fabricfilter. Dry sorption of SO2onto the lime or limestone particle occurs and thesolidparticles are collected with a fabric filter5 Spray Dryer Absorption (SDA)Y Y Y NLime slurry is sprayed into an absorption tower where SO2is absorbed by theslurry, forming CaSO3/CaSO46 Alternative FuelsY YY(for furnacescapable ofmultiple fuels)Y(not requiredby BART)Natural gas is base case Use a fuel with lower sulfur content.7 Load ReductionN --- --- ---Power plant technologyThis is a strategy to reduce load on a power plantby reducing the electrical demandthrought efficiency projects.8 Energy Efficiency ProjectsY YY(for largeprojects likeheat-recoup)Y(for largeprojects likeheat-recoup)decrease amount of fuel required to make an acceptable product9 Coal DryingY N --- ---Applies only to facilities that burn coalDry coal will increase the as-burned BTU value, andtherefore less fuel is requiredto be burned. Specific energy efficiency project10 Bio FiltersN --- --- ---Research levelGas stream passes through a packed bed of speciallyengineered biomedia whichsupports the growth of active bacterial species. The pollutants in the gas stream arebiodegraded or biotransformed into innocuous products, such as carbon dioxide,water, chloride ion in water, sulfate or nitrate ions in water.11CANSOLV Regenerable SO2N --- --- ---Research levelAn aqueous solution of proprietary diamine capturesSO2from the feed gas in acountercurrent absorption tower. The rich solvent is regenerated by steam stripping,giving a byproduct of pure, water saturated SO2gas and lean solvent for recyclingto the absorber.12 Pahlman ProcessN --- --- ---Research levelGas stream is passed through a filter baghouse in which specially-developed, smallparticle, high-surface area metal oxide sorbent have been deployed. Pollutants areremoved from the gases by adsorption.Taconite BART AnalysisSO2 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.

Reference No.

1SO2Pollution 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 SOx-NOx-Rox-BoxN --- --- ---Technology has not been demonstratedDry sorbent injection upstream of the baghouse forremoval of SOx and ammoniainjection upstream of a zeolitic selective catalytic reduction (SCR) catalystincorporated in the baghouse to reduce NOx emissions.14 Electron (E-Beam) ProcessN --- --- ---No operating commercial applications oncoalElectron beam irradiation in the presence of ammonia to initiate chemicalconversion of sulfur and nitrogen oxides into components which can be easilycollected by conventional methods such as an ESP orbaghouse.15 Electrocatalytic OxidationN --- --- ---Similar to cold plasma. Will keep watch foravailability of this technologyUtilizes a reactor in which SO2, NOx, and mercury are oxidized to nitrogen dioxide(NO2), sulfuric acid, and mercuric oxide respectively using non-thermal plasma.On recent project, the vender was doing final trials on full-scale applications.16 NOXSON --- --- ---Commercial version of adsorption. Limitedexperience (proof-of-concept tests).Uses a regenerable sorbent to simultaneously adsorbSO2and NOx from flue gasfrom coal-fired utility and industrial boilers. Inthe process, the SO2is converted toa saleable sulfur by-product (liquid SO2, elemental sulfur, or sulfuric acid) and theNOx is converted to nitrogen and oxygen.17 Copper-OxideN --- --- ---Absorption and SCR. Experience limited topilot scale.SO2in the flue gas reacts with copper oxide, supported on small spheres ofalumina, to form copper sulfate. Ammonia is injected into the flue gas before theabsorption reactor and a selective catalytic reduction-type reaction occurs thatreduces the nitric oxides in the flue gas. In the regeneration step, the copper sulfateis reduced in a regenerator with a reducing agent,such as natural gas, producing aconcentrated stream of SO2.18 SNOXN --- --- ---Early commercial development stageCatalytic reduction of NOx in the presence of ammonia (NH3), followed bycatalytic oxidation of SO2to SO3. The exit gas from the SO3converter passesthrough a novel glass-tube condenser in which the SO3is hydrated to H2SO4vaporand then condensed to a concentrated liquid sulfuric acid (H2SO4).19 Cold PlasmaN --- --- ---Research level1) 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.htm2) c) New and Emerging Environmental Technologies,http://neet.rti.org/2) d) ND BART Reports