The desulfuration experiments for activated carbon fibre (ACF) and granular activated carbon(GAC) were performed in three systems including SO2+O2+N2(dry state),SO2+O2+N2+H2O(gas state) and SO2+O2+N2+H2O(liquid state), to investigate the surface structural change caused by desulfuratlon. Using SEM, BET, XPS, the morphology of fiber surface, the specific surface of fiber and the amount of the acidic functional groups on the activated carbon surface were determined respectively. The results showed that desulfurating in SO2+O2+N2+H2O(liquid state), the best desulfuration effect is obtained and the amount of H2O in SO2+O2+N2 favour improving the effect of desulfuration. The increase of the amount of COOH(R) groups on the activated carbon improves the effect of desulfuration. The amount of functional groups on the ACF during desulfuration is larger than GAC.
