FGD Flue Gas Desulfurization FHWA Federal Highway Administration FRP Flood Risk Profile ft-msl Feet Mean Sea Level gpm Gallons per Minute I-40 Interstate Highway 40 i.e. CIE (Cambridge International) A level chemistry syllabus learning outcomes 9.6(e), 9.6(f), 9.6(g), 9.6(h), 9.6(i) ... but there are ways of removing this from the flue gases, known as "flue gas desulphurisation". Flue gas desulfurization equipment The boiler is the furnace where fossil fuels as coal and wood moistures are burned. The information in this section was obtained from a US EPA published fact sheet. The use of instrument configurations and/or accessories designed to accommodate samples with high dissolved solids levels is highly recommended. The wet flue gas desulfurization (FGD) process, a commonly applied technology for the removal of SO 2 from flue gas, can also remove some heavy metals 5; thus, the generation of large amounts of FGD wastewater can also contain various heavy metals, (e.g., arsenic, lead, mercury and selenium) 5,6. In this study, a simulated limestone–gypsum WFGD platform was used to study the emission characteristics of water-soluble ions in flue gas after desulfurization. ***ARE YOU NERVOUS FOR YOUR GCSE's...PREDICTIONS*** How did that exam go?! A new, emerging flue gas desulfurization technology has been described by the IAEA. The impact of these parameters on mercury vapor pressure was studied under controlled laboratory conditions in model scrubber suspensions. Applicable Pollutants: Sulfur dioxide (SO 2) Achievable Emission Limits/Reductions: Scrubbers are capable of reduction efficiencies in the range of 50% to 98%. The best of these methods allow the sulphur dioxide to be recovered and then converted into sulphuric acid. These feeder lines extend within the flue gas flow path in an alternating and staggered configuration within the same plane. rate, unit cost, technology maturity level, example analysis of reconstruction costs in existing units FGD（wet flue gas desulfurization system） and investment costs in new unit FGD. Reviews in Chemical Engineering 2015, 31 (4) DOI: 10.1515/revce-2015-0002. The lime reacts with the SO2 to form sulfates which become part of the ash. Scottish Power are spending £400 million installing FGD at Longannet power station, which has a capacity of over 2 GW. The action of the electron beam is to promote the oxidation of sulfur dioxide to sulfur(VI) compounds. The limestone slurry sucked from the absorber sump is finely sprayed co-currently and counter-currently to the flue gas through the spraying levels. Flue Gas Desulfurization is a widely adapted technology for removing sulfur dioxide from the exhaust flue gas in coal- and oil-fired power plants. This method has been developed by Paqell, a joint venture between Shell Global Solutions and Paques. No radioactivity is required or created in the process. Approximately 85% of the flue gas desulfurization units installed in the US are wet scrubbers, 12% are spray dry systems, and 3% are dry injection systems. The electron beam is generated by a device similar to the electron gun in a TV set. EPS launched the project for the installation of flue gas desulfurization unit at its coal-fired thermal power plant Nikola Tesla B (TENT B). Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)  However, the accelerator design principles and manufacturing quality need further improvement for continuous operation in industrial conditions.. Flue-gas desulfurization (FGD) is the removal process of sulfur dioxide (SO 2) from flue gas emissions, often chemically.Sulfur dioxide in gases is produced by the combustion of fossil fuels and many industrial processes such as gasoline refining as well as cement, paper, glass, steel, iron … The cocurrent contact of slurry and flue gas allows for a. The flue gas flows into the absorber above the fluid level and then through the absorption zone, which comprises overlapping spraying levels and a mist eliminator. The reason why it is difficult to predict sulfur dioxide removal efficiency in flue gas is that it is related to many factors. It is important to consider this question both in light of the recent large increase in knowledge of FGD technologies and also with sober regard to the disappointments anad failures that have contributed to the new knowledge. It is allowed to react with an wet mixture of calcium carbonate to form solid calcium sulfite. Dry sorbent injection systems that introduce powdered hydrated lime (or other sorbent material) into exhaust ducts to eliminate SO2 and SO3 from process emissions. Chemical Equation: CaCO3 (s) + SO2 (g) → CaSO3 (s) + CO2 (g) 2CaSO3 (s) + O2 (g) → 2CaSO4 (s). The inlet flue gas was 140 °C with SO 2 concentration of 773.4 ppm and the Ca/S molar ratio was 1.3. Chemineer distinguishes itself from the compe-tition through the … Flue gas desulfurization refers to a technology that is utilized in the removal of sulphur dioxide (SO2) from flue gas. The total jet water flow rates were 52 kg/h and 2-level … While a chemical change does occur during the extraction of the sulfur dioxide from the gas mixture, it is the case that the extraction equilibrium is shifted by changing the temperature rather than by the use of a chemical reagent. A flue-gas stack, also known as a smoke stack, chimney stack or simply as a stack, is a type of chimney, a vertical pipe, channel or similar structure through which combustion product gases called flue gases are exhausted to the outside air. 2H2O) which is marketable for use in the building products industry. In the case of the normally used absorption additive lime, the oxidation of S(IV) is an essential step in quantitatively producing the final product, gypsum (CaSO 4 - 2H 2 O). The limestone–gypsum wet flue gas desulfurization (WFGD) process has a significant influence on the emission characteristics of soluble ions in particulates. The capital, operating and maintenance costs per short ton of SO2 removed (in 2001 US dollars) are: An alternative to removing sulfur from the flue gases after burning is to remove the sulfur from the fuel before or during combustion. Since the sodium sulfite solution is not consumed, it is called a regenerative treatment. Safety is one of the greatest benefits of this method, as the whole process takes place at atmospheric pressure and ambient temperature. This reaction is of great interest in the study of wet flue gas desulfurization processes. Legislation in the United States and worldwide requires increasingly high levels of SO 2 removal, driving the need for efficient applications of FGD technology. The ammonia reacts with the sulfur compounds thus formed to produce ammonium sulfate, which can be used as a nitrogenous fertilizer. The limestone slurry sucked from the absorber sump is finely sprayed co-currently and counter-currently to the flue gas …  It is a radiation technology where an intense beam of electrons is fired into the flue gas at the same time as ammonia is added to the gas. Besides, it delivers a complete assessment of several industry segments to provide a clear picture of the top revenue prospects of this industry vertical. Reactor flue gas desulfurization method is a new type of wet technology. For Flue gas desulfurization in Chem1, do i need to know about calcium oxide only or calcium carbonate, calcium hydroxide and gypsum? This paper introduced the fundamental principle of the simultaneous desulfurization and denitrification by combining ozone oxidation and the NaOH double alkali method. Both plants are reported to be operating successfully. FGD has been fitted by RWE npower at Aberthaw Power Station in south Wales using the seawater process and works successfully on the 1580MW plant. Beside detoxication of S(IV) the dewatering properties of gypsum are improved when a high oxidation yield is achieved. A simplified representation structure of the desulfurization tower based on plant data was presented in Fig. Level and Flow Instrumentation for Flue Gas Desulfurization Systems. It produces a "spent caustic" solution of sodium sulfite/bisulfite (depending on the pH), or sodium sulfate that must be disposed of. However, the newer designs for dry scrubbers are capable of achieving efficiencies in the order of 90%. Simultaneously, fluid absorbent is also divided into two shares, and dispersed into mist by the pressure nozzles, exhaled through the gas diversion tube exit and mixed with the gas. All wet scrubbers require mist elimination, and most require reheat of the cleaned flue gas. In Proceedings: Symposium on Flue Gas Desulfurization—Hollywood, FL Vol. Designing FGD treatment units hugely depends on the capital cost and operational and management (O&M) costs. Name of Technology: Flue Gas Desulfurization (FGD) - Wet, Spray Dry, and Dry Scrubbers Type of Technology: Control Device - absorption and reaction using an alkaline reagent to produce a solid compound. Chemical Equation: CaO (s) + SO2 (g) → CaSO3 (s) 2CaSO3 (s) + O2 (g) → 2CaSO4 (s), Balancing of Chemical Equations – 2012/P1/Q12 [Online Video], Mole Concept and Chemical Calculation – Empirical Formula – 2015/P1/Q15 & 2008/P1/13 [Online Video], Atomic Structure – 2016/P1/Q4 [Online Video], Acids, Bases, Salts – 2014/P1/Q29 [Online Video], Chemical Bonding – Drawing Dot and Cross Diagram 2012/P1/Q9 [Online Video], Electrolysis – Parts of an electrolytic Cell, 40 Chemical Substances All Students Must Know [Online Video]. Level and Flow Solutions For Flue Gas Desulfurization. The Chendu power plant in China started up such a flue gas desulfurization unit on a 100 MW scale in 1998. This is an example of a radiation chemistry process where the physical effects of radiation are used to process a substance. Not what you're looking for? In the “wet limestone-gypsum” form of FGD, an aqueous slurry of finely ground limestone is introduced into an absorber tower and contacted with the flue gas. This spray level incorporates multiple headers with each header having a plurality of feeder lines connected thereto. The particulate collector is designed and operated as an integral part of the acid gas removal process as the solids continue to react with SO 2, SO 3, HCl and HF in the humidified flue gas. According to Grcic, the new desulfurization unit will reduce the level of air pollution from the current 80,000 tons of sulfur-dioxide annually to 4,500 tons, namely SO2 emissions will be reduced 20 times. In the “wet limestone-gypsum” form of FGD, an aqueous slurry of finely ground limestone is introduced into an absorber tower and contacted with the flue gas. For wet scrubbers larger than 400 MW, the cost is $200 to $500 per ton, For wet scrubbers smaller than 400 MW, the cost is $500 to $5,000 per ton, For spray dry scrubbers larger than 200 MW, the cost is $150 to $300 per ton, For spray dry scrubbers smaller than 200 MW, the cost is $500 to $4,000 per ton, This page was last edited on 16 October 2020, at 06:23. The process of removing sulfur dioxide from flue gases is called flue gas desulfurisation. Introduction Flue gas desulfurization (FGD) processes are usually categorized as wet and dry or semi-dry systems. Waste gases are called flue gas. Hydrodesulfurization of fuel has been used for treating fuel oils before use. equations were developed. 15Ponder, W. H. "Status of Flue Gas Desulfurization Technology for Power Plant Pollution Control." Chemical Equation: CaCO 3 (s) + SO 2 (g) → CaSO 3 (s) + CO 2 (g) 2CaSO 3 (s) + O 2 (g) → 2CaSO 4 (s) Alternatively, the acidic sulfur dioxide is allowed to react with basic calcium oxide to form calcium sulfite, which is then oxidised to calcium sulfate. Statement 13.2(a) This statement is about the formation of atmospheric sulphur dioxide from burning fossil fuels. After fly ash removal, the flue gas (seen in Figure 1) is bubbled through the scrubber, and the slurry is added from above.The lime or limestone reacts with the SO 2 in the flue gas to create insoluble calcium sulfite (CaSO 3) as in the equations below. In spray drying and dry injection systems, the flue gas must first be cooled to about 10–20 °C above adiabatic saturation to avoid wet solids deposition on downstream equipment and plugging of baghouses. The design temperature to operate the furnace is ideally above the meting point of the ash, as the buildup of hard slag increases maintenance costs. The shape of the spray dryer requires that a body fitted orthogonal coordinate system be used for the numerical model. It is a control device that absorbs and react using the alkaline reagent to produce a solid compound. 0. reply. Fluidized bed combustion adds lime to the fuel during combustion. ----- Flue gas/off-gas Cleaned flue gas Absorption liquor Sulfur products Other systems Off-site disposal Settling pond Waste solids Figure 4. Learning outcomes 13.2(a) and 13.2(b) These statements are about the environmental consequences of the formation of sulphur dioxide. In wet FGD processes flue gas is contacted with a slurry consisting of a sorbent in an aqueous medium, such that the flue gas … At the arbitrary level, the variables are Y, X and X', while at the top they are Yout, Xin and Xin'. Dry scrubbers and spray scrubbers have generally been applied to units smaller than 300 MW. Presented at the Thermal Power Conference, Washington State University, Oct. 1 974. ･ 670 MW desulfurization capacity per unit will reduce SO 2 and particulates emissions, to aid compliance with EU environmental standards and support Serbia’s quest to join EU ･ Second FGD system order from Serbia, and third from Western Balkans region. The better desulfurization properties of the low‐grade manganese ores are ascribed to the highly active γ‐MnO 2, the porous structure, and the high specific surface area as well as the SiO 2 bridge‐like effects. Flue-Gas Desulfurization (“Scrubbers”) (Nazaroff & Alvarez-Cohen, Se ction 7.C.2, much augmented) ... tower, from an arbitrary level to the top. DOI: 10.1016/j.cej.2013.03.084. Introduction Flue gas desulfurization (FGD) processes are usually categorized as wet and dry or semi-dry systems. The chemistry of desulfurization The liquid used to “wash” the flue gas is a water-based calcium solution. http://www.dakotagas.com http://www.basinelectric.com Carbon dioxide gas is also formed. 1. Chemguide: Support for CIE A level Chemistry. ----- Technology Transfer EPA 625/8-80-004 Summary Report Sulfur Oxides Control Technology Series: Flue Gas Desulfurization Dual Alkali Process October 1 980 LIBRARY U S. ENVIRONMENTAL PfittTECTlOH EDISON, H. J- 08817 This report was developed by the Industrial Environmental Research Laboratory Research Triangle Park NC 27711 S-EPA United States Environmental Protection Agency Municipal Environmental Research Laboratory Cincinnati OH 45268 Research and Development EPA-600/S2-81-062 July 1981 Project Summary Chemical Speciation of Flue Gas Desulfurization (FGD) Sludge Constituents James Lu This project studies the problem of flue gas desulfurization (FGD) sludge disposal to land. The application of this reaction is also known as the Wellman–Lord process. Limestone (CaCO3) is cheap and creates an alkaline environment in water: Dublin, Oct. 28, 2020 (GLOBE NEWSWIRE) -- The "Asia Pacific Flue Gas Desulfurization Market By Type (Dry FGD System, Semi-dry FGD System, Wet FGD System), By Installation (Greenfield, Brownfield), By End User (Power generation, Chemical, Iron & Steel Industry, Others), By Country, Forecast & Opportunities, 2025" report has been added to ResearchAndMarkets.com's offering. The desulfurization product adheres to the surface of coarse particles after water is vaporized. With the increasing coal prices, the decreasing coal quality, the operation and maintenance cost of the desulfurization system was increasing greatly  You can also choose from high pressure flue gas desulfurization fgd, as well as from 1 year flue gas desulfurization fgd, and whether flue gas desulfurization fgd is none, united kingdom, or egypt. Xiaoping Wang, Zhongjian Li, Lecheng Lei. flue gas spray level gas desulfurization spray level Prior art date 1991-07-26 Legal status (The legal status is an assumption and is not a legal conclusion. We investigated the effect of several operating parameters, such as enzyme concentration, biogas flow rate, amount of packing material, and periodic enzyme replenishment, on the enzymatic biogas desulfurization performance. Try… What would you give your GCSE exams out of 10? This method was developed on an Agilent 7700 ICP/MS using the High Matrix … , Scrubbing with an alkali solid or solution, Gas phase oxidation followed by reaction with ammonia, Alternative methods of reducing sulfur dioxide emissions, ASME, 2017, "Flue Gas Desulfurization Units", ASME PTC 40-2017, exhaust flue gases of fossil-fuel power plants, United Nations Convention on the Law Of the Sea, Flue-gas emissions from fossil-fuel combustion, https://www.nol-tec.com/products/dry-sorbent-injection-dsi/, "Flue Gas Desulfurization - FGD Wastewater Treatment | Compositech Filters Manufacturer", "Experience curves for power plant emission control technologies", http://www.imo.org/en/OurWork/Environment/PollutionPrevention/AirPollution/Pages/Index-of-MEPC-Resolutions-and-Guidelines-related-to-MARPOL-Annex-VI.aspx, "Removal of Sulphur Dioxide from Flue Gases in Thermal Plants", "Steam Electric Power Generating Effluent Guidelines - 2015 Final Rule", "Lowering Cost and Waste in Flue Gas Desulfurization Wastewater Treatment", "Electron beam application in gas waste treatment in China", "Application of ionizing radiation to environment protection", "Air Pollution Control Technology Fact Sheet: Flue Gas Desulfurization", Alstom presentation to UN-ECE on air pollution control, https://en.wikipedia.org/w/index.php?title=Flue-gas_desulfurization&oldid=983782175, Environmental impact of the energy industry, All Wikipedia articles written in American English, Creative Commons Attribution-ShareAlike License. Calcium sulfite then further oxidises to calcium sulfate by atmospheric oxygen, which is then dumped. The 2016 GCSE Exam Sentiment Thread! In the “wet limestone-gypsum” form of FGD, an aqueous slurry of finely ground limestone is introduced into an absorber tower and contacted with the flue gas. By utilizing laboratory testing and industry-leading technology, Chemineer can design the ideal mixing system for your process. Many countries rely on coal resources to maintain low energy costs and ensure a level of energy security. YOKOHAMA, JAPAN (October 22, 2020) – Mitsubishi Power, a subsidiary of Mitsubishi Heavy Industries (MHI) Group, has received an … This device is called an accelerator. coal-fired plant or for lean-sulfur flue gas, while regenerative FGD is well suited for plants producing high SO 2 content, e.g., flue gas prevailing from copper converting units (Roy and Sardar 2015). Wet flue gas desulfurization is widely used in power plants because of its high desulfurization efficiency. The highest SO2 removal efficiencies (greater than 90%) are achieved by wet scrubbers and the lowest (less than 80%) by dry scrubbers. Numerical flue gas flow analysis in wet limestone Flue Gas Desulfurization installation using Computational Fluid Dynamics Kamil Bogdan Chłosta Thesis to obtain the Master of Science Degree in Energy Engineering and Management Supervisors: Prof. Luís Rego da Cunha de Eça Dr. Karol Sztekler Examination Committee Chairperson: Prof. Edgar Caetano Fernandes Supervisor: Prof. Luís Rego da … Chemical Equation: CaO (s) + SO 2 (g) → CaSO 3 (s) 2CaSO 3 (s) + O 2 (g) → 2CaSO 4 (s) Due to the high dissolved solids content of this wastewater stream, recycling for reuse internally in the power plant is normally quite challenging. In some ways this can be thought of as being similar to the reversible liquid–liquid extraction of an inert gas such as xenon or radon (or some other solute which does not undergo a chemical change during the extraction) from water to another phase. The newly ordered FGD systems each have a flue gas desulfurization capacity of 670 megawatts (MW), with operation scheduled to commence in 2024. Flue gas desulphurization scrubber systems create a wastewater stream that is difficult to handle because of its high suspended solids, metals and chlorides content. The cooled and treated flue gas exits the SDA and is directed to a particulate collector, typically a fabric filter. Flue gas desulfurization scrubbers have been applied to combustion units firing coal and oil that range in size from 5 MW to 1500 MW. The Pomorzany power plant in Poland also started up a similar sized unit in 2003 and that plant removes both sulfur and nitrogen oxides. In addition, it can be used to lower the nitrogen oxide content of the flue gas. The Wet Flue Gas Desulfurization Process. Sulfur dioxide is one of the waste gases from combustion of fossil fuels. Sulfite oxidation in seawater flue gas desulfurization by plate falling film corona-streamer discharge. "Status of SO2 and NOX Removal Systems in Japan." This method has attained industrial plant scale.. This is not a problem in a kraft pulp mill for example, where this can be a source of makeup chemicals to the recovery cycle. trickles down while the gas bubbles up through it, and (2) the fumes encounter increasingly less loaded liquid as they get progressively cleaner on their way upward. B&W uses both advanced numerical modeling and physical modeling to design the most efficient wet flue gas desulfurization systems. It is possible to scrub sulfur dioxide by using a cold solution of sodium sulfite; this forms a sodium hydrogen sulfite solution. Before you go on, you should find and read the statements in your copy of the syllabus. The effect of such regulations was a trend toward the use of low-sulfur oil and coal, and, where possible, of the cleanest fuel, natural gas. Latin term, id est, meaning “that is” IC 25 25 percent inhibition concentration ISC3 Industrial Source Complex 3 KIF Kingston Fossil Plant km Kilometer kV Kilovolt lb Pound 1. Lime/Limestone FGD Process: (a) Absorption, (b) Solids Precipitation, and (c) Concentration and Disposal Mist Elimination and Stack Gas Reheat. In this paper we evaluate the effects of the pH level, different gypsum qualities, and iron in flue gas desulfurization (FGD) scrubber suspensions. 16Ando, J. Desulfurization of simulated biogas containing high levels of H 2 S (3009 or 3020 ppm) is demonstrated in a semi-batch reactor using a novel enzyme. Alternatively, the acidic sulfur dioxide is allowed to react with basic calcium oxide to form calcium sulfite, which is then oxidised to calcium sulfate. The operation parameters of corresponding experiments are listed as follows: the flue gas flux was 1831 N m 3 /h. One industrial process that produces synthetic gypsum is flue‐gas desulfurization (FGD), which is used to remove gaseous sulfur dioxide from boiler exhaust gas derived from coal‐fired power plants, steel plants, and other heating plants. The Wet Flue Gas Desulfurization Process Flue Gas Desulfurization is a widely adapted technology for removing sulfur dioxide from the exhaust flue gas in coal- and oil-fired power plants. In wet FGD processes flue gas is contacted with a slurry consisting of a sorbent in an aqueous medium, such that the flue gas is cooled to the adiabatic saturation temperature. In this paper, the SO2 was removed by absorbing with ammonia solution in a packed tower. products for Flue Gas Desulfurization (FGD) systems throughout the world for over 30 years. Waste gases are produced when fossil fuels undergo combustion. The governing equations are developed in the general orthogonal coordinates and discretized to yield a system of algebraic equations. 9. Caustic soda is limited to smaller combustion units because it is more expensive than lime, but it has the advantage that it forms a solution rather than a slurry. A wide variety of flue gas desulfurization fgd options are available to you, such as energy & mining, building material shops. Shaojuan Zeng, Hongshuai Gao, Xiaochun Zhang, Haifeng Dong, Xiangping Zhang, Suojiang Zhang. a) Wet FGD Without B&W Tray b) Wet FGD With B&W Tray Outlet Outlet Gas Velocity Magnitude (ft/s) 30 28 26 24 22 20 18 16 14 10 8 6 4 2 0 Slurry Level Slurry Level Flue Gas Desulfurization: The State of the Art [J] January 2002; ... downflow absorber with a single level of grid packing. Explaining the flue gas desulfurization process at Great Plains Synfuels Plant. Are flue gas desulfurization (FGD) systems reliable and operable for scrubbing stack gas effluents from the combustion of high sulfur coal of the eastern United States? By heating this solution it is possible to reverse the reaction to form sulfur dioxide and the sodium sulfite solution. The expanding global demand for energy has led to growth in the power generation market. And the total chemical reaction equations were achieved by analyzing the process of the absorption of the productions of ozone oxidation by NaOH double alkali method. The level of lime in the feed slurry provided to the dry scrubber is thus increased, which enhances removal of sulfur oxide species in the dry scrubber. While many power generation companies have moved away from coal due to an increasingly stringent regulatory environment and/or concerns with climate change, many countries … This makes it easier to operate. This elemental sulfur is then separated and finally recovered at the end of the process for further usage in, for example, agricultural products. Global Flue Gas Desulphurization Market: Overview Flue gas desulfurization refers to a technology that is utilized in the removal of sulphur dioxide (SO2) from flue gas. Sulfur dioxide gas is an acidic oxide. The latest Flue Gas Desulfurization market report offers a detailed analysis of growth driving factors, challenges, and opportunities that will govern the industry expansion in the ensuing years. ----- FLUE GAS DESULFURIZATION Answers to Basic Questions INTRODUCTION In the late 1960's, many state and local jurisdictions enacted regulations to curb 5)0*2 emissions from coal- and oil-burning power plants. Flue-gas desulfurization (FGD) is a set of technologies used to remove sulfur dioxide (SO2) from exhaust flue gases of fossil- fuel power plants, and from the emissions of other sulphur oxide emitting processes. The influences of liquid-to-gas ratio, SO2 concentration of inlet flue gas, and combination mode of different spray levels to the desulfurization efficiency were analyzed. substantially reduced by the use of flue gas desulfurization (FGD) technology in coal-fired power plants. 8. EPA-452/F-03-034 Air Pollution Control Technology Fact Sheet EPA-CICA Fact Sheet Flue Gas Desulfurization1 Name of Technology: Flue Gas Desulfurization (FGD) - Wet, Spray Dry, and Dry Scrubbers Type of Technology: Control Device - absorption and reaction using an alkaline reagent to produce a solid compound. Posted by Magnetrol International November 17, 2015 November 17, 2015 Posted in Flue Gas Desulfurization Tags: Flue Gas Desulfurization. The highest removal … Based on a foundation of past findings, a simplified three-step reaction pathway was hypothesized for the formation of the plume-discoloring constituent, NO2. 1. This study supports the cooperative use of sulfur‐containing flue gases and low‐grade natural manganese oxides.