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

Abstract

The sulfidation behaviors of iron-based sorbent with MgO and MgO-TiO2 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 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 N2, 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 can shift the optimal sulfidation temperature lower. The iron-based sorbent with 3% MgO and 10% TiO2 (MFT) is active to the deep removal of H2S 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.

Testing of hydrotalcite-based sorbents for CO2 and H2S capture for use in sorption enhanced water gas shift

“…Similar competitive adsorption has been reported for ZnO (Novochinskii et al, 2004;Fan et al, 2003). Type B sites would exclusively take up H 2 S reversibly, involving the formation of a metal sulphide (Toops and Crocker, 2008;Bao et al, 2009). The metal sulphide would be formed from the metal oxide at H 2 S-rich conditions, while the presence of steam and the absence of H 2 S during regeneration would result in partial backformation of the metal oxide and release of H 2 S according to the following reaction equation:…”

Removal of Hydrogen Sulfide and Ammonia by Goethite-Rich Limonite in the Coexistence of Coke Oven Gas Components

“…[19][20][21][22][23] Thus, it is possible that limonite-derived α-Fe will be a good adsorbent for H 2 S in COG. However, only a few studies have reported H 2 S removal in COG by iron-based adsorbents, such as iron oxide and/or iron-bearing sorbents combined with other metals.…”

H2S adsorption and decomposition on the gradually reduced α-Fe2O3(001) surface: A DFT study

“…Based on this, there were many investigations of single metal oxide and mixed metal oxides as sorbents in the past [7][8][9][10][11]. And iron oxide has become the study focus for advantages of low cost, high sulfurization rate, good regeneration ability and superior sulfur capacity [12][13][14][15].…”