Investigation On The Simultaneously Carbonation And Desulfurization Of CaO Under Oxy-fuel Fired In CFB

With oxy-fuel CFB firing, the CO2 content is high (>80%), Therefore, decomposition of limestone does not occur in general. When burning anthracites and petroleum cokes, it is possible that combustor temperature can rise to above 900℃, at which decomposition of limestone will occur. As there is high concentration of CO2 and a certain concentration of SO2 in flue gas, carbonation and sulfuration of CaO in the ash deposits was occurred, making the ash deposits on the heat transfer surfaces more difficult to remove, may cause operational problems and boiler maintenance issues. In this paper, the simultaneously carbonation and desulfurization of CaO under oxy-fuel fired was investigated. The research showed, the temperature, the concentrations of CO2, SO2 and water vapor played an important role on the reaction. A model was presented to describe the process of the reaction. The calculation results are of agreement with the experimental data.