Desulfurization Behavior of Iron-based Sorbent with MgO and TiO2Additive in Hot Coal Gas

The sulfidation behaviors of iron-based sorbent with MgO and MgO-TiO 2 are studied under different isothermal conditions from 623 to 873 K in a fixed bed reactor. The results of sorbents sulfidation experiments indicate that the sorbents with MgO and TiO 2 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 TiO 2 in sorbent can shift the optimal sulfidation temperature lower. The iron-based sorbent with 3% MgO and 10% TiO 2 (MFT) is active to the deep removal of H 2 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.