Effects of Temperature and CO Concentration on Reduction of Calcium Sulfate in Fixed Bed and Circulating Fluidized Bed

For qualitative understanding of the sulphur capture process in a circulating fluidized bed furnace, the effects of temperature and CO concentration on the reactivity of partially sulfated CaO were experimentally examined. The tests were performed in a fixed bed reactor and lab-scale circulating fluidized bed reactor. The materials used were partially sulfated domestic limestone and bottom ash drained from commercial circulating fluidized bed furnaces. The re-emission of SO2 from partially sulfated limestone and bottom ash increases with temperature as well as with the concentration of the reducing agent CO. From the results of this study, the temperature dependence of sulfation could be explained by reduction theory.