Reduction of calcium sulfate in a coal-fired circulating fluidized bed furnace

For a quantitative understanding of the sulfur capture process in a CFB furnace, the reactivity of partially sulfated CaO was studied. The material used was bottom ash drained from a 165 MWe commercial CFB boiler furnace. The tests were performed in an electrically heated furnace. Reactivity rate constants were determined from the experimental results. The release of SO2 from CaSO4 increases with temperature as well as with the concentration of the reducing agents CO, char and graphite. Of the reducing agents considered, CO is most reactive, followed by char and then graphite. Copyright (C) 1996 Elsevier Science Ltd.