Combustion of coal in an oxygen environment (as opposed to air) will facilitate the sequestering of carbon dioxide by minimizing the amount of nitrogen in the exit gas stream. The presence of different levels of gases associated with Oxyfuel combustion (e.g., CO{sub}2, SO{sub}2, and H{sub}2O) may significantly impact the corrosion of waterwalls, superheaters, headers, reheaters, and other boiler components. Research is being conducted on ash-covered boiler tube materials in simulated oxyfuel/recycled flue gas-fired (Oxy/RFG) and air-fired environments at superheater and waterwall temperatures. Alloys T22, T92, 347SS, and Inc 617 were covered with a synthetic ash mixture composed of iron oxide, sodium sulfate, and potassium sulfate and exposed at a superheater temperature of 675°C. Preliminary results show very aggressive corrosion rates with an increase in corrosion of the alloys exposed to the Oxy/RFG-fired environment when compared to the air-fired environment.
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