Sulfation behavior of CaO during sequential SO2/CO2 capture process

Abstract：The sulfation behavior of CaO and SO2 after the carbonation/calcination cycles was evaluated in a fixed-bed and a thermogravimetic analyzer. The effects of cycle number, particle size, sulfation temperature and microstructure on sulfation conversion of CaO were investigated. The results show that the sulfation conversion of CaO decreases rapidly with the cycle number during the previous 20 cycles, and then it keeps stably with increasing the cycle number fur- ther. However, after 130 cycles, the sulfation conversion of CaO begins to increase with the number of cycles. The sul- fation conversions of initial CaO ,CaO after 40 cycles and 150 cycles are 0. 480,0. 207 and 0. 243 ,respectively. The particle size has the same effect on CaO sulfation conversion at the different cycles. The bigger the particle size is, the smaller the CaO sulfation conversion is. The reaction temperature between 800 and 950 ℃ has a little effect on the sul- fation conversion of initial CaO. However, the reaction temperature shows an obvious effect on the sulfation conversion of CaO with the number of cycles. Moreover, higher reaction temperature results in greater sulfation conversion of CaO with the number of cycles.