“Catalytic oxidation of calcium bisulfite in the wet limestone–gypsum flue gas desulfurization process”

A study on the oxidation of calcium sul"te catalyzed by Mn2` is presented in this paper. A laboratory-scale well-mixed thermostated reactor was used, with continuous feeding of both gas and liquid phase. The gas phase was a mixture of oxygen and nitrogen, with O2 partial pressure varying from 5.1 to 40.5 kPa. The liquid phase was obtained by mixing inside the reactor two separate aqueous solutions, one obtained by dissolving Ca(OH)2 into a SO2 solution, and the other one containing manganous sulfate. The temperature was kept constant in all the experiments at 453C. The results show that increasing catalyst concentration, the transition takes place from slow kinetic to slow di!usional and eventually to fast reaction regime