Decomposition behavior and mechanism of calcium sulfate under the condition of O-2/CO2 pulverized coal combustion

The decomposition behavior and mechanism of calcium sulfate in O-2/CO2 pulv erized coal combustion were studied in an entrained flow reactor. A reactio n rate expression correlating the influence of various factors was proposed for CaSO4 decomposition and it is able to predict CaSO4 decomposition sati sfactorily. Under the conditions investigated, the decomposition of CaSO4 w as found to be a regime of chemically controlled shrinking core reaction. A CO2-rich atmosphere enhances CaSO4 decomposition in absence of oxygen. CaS O4 particles have catalytic effect on formation of CO from CO2. A high SO2 concentration inhibits CaSO4 decomposition. The kinetics of CaSO4 decomposi tion has obvious dependence on experimental facilities and conditions, wher eas the activation energy has much lower dependence. The kinetics derived i n this work is more appropriate for investigating desulfurization in O-2/CO 2 pulverized coal combustion because an entrained flow reactor has a much c loser condition to that in O-2/CO2 pulverized coal combustion than a TGA.