Desulfurization Behavior of Iron-based Sorbent with MgO and TiO2 Additive in Hot Coal Gas

The sulfidation behaviors of iron-based sorbent With MgO and MgO-TiO2 are studied under different isothermal conditions from 623 to 973 K in a fixed bed reactor. The results of sorbents sulfidation experiments indicate that the sorbents with MgO and TiO2 additives are more attractive than those without additives for desulfurization of hot coal gas. The sulfur capacity (16.17, 18.45, and 19.68 g S/100 g sorbent) of M1F, M3F, and M5F sorbent containing 1, 3, and 5% MgO, respectively, is obviously bigger than that (15.02 g S/100 g sorbent) of M0F without additive. The feasible sulfidation temperature range for M3F sorbent is 773-873 K. The M3F sorbent is optimally regenerated at the temperature of 873 K, under the gas containing 2% oxygen, 15% steam and N-2, in the space velocity of 2500 h(-1). The sorbent regenerated is also well performed in the second sulfidation (the effective sulfur capacities of 17.98 g S/100 g sorbents and the efficiency of removal Sulfur of 99%). The capacity to remove sulfur decreases with steam content increasing in feeding gas from 0 to 10%, but it can restrain the formation of carbon and iron carbide. The addition of TiO2 in sorbent call shift the optimal sulfidation temperature lower. The iron-based sorbent with 3%, MgO and 10% TiO2 (MFT) is active to the deep removal of H,S and COS, especially in the temperature range of 673-723 K. The sulfur removal capacity of MFT sorbent is 21.60 g S/100 g sorbent.