Manganese-based sorbents for coal gas desulfurization

The intent of this study is to perform a preliminary screening on a particular Mn-based sorbent, CST-939 (from Chemetals), for hot gas desulfurization. The purpose of the preliminary screening is to determine which temperature and type of coal gas this sorbent demonstrates the greatest capacity and efficiency for sulfur removal. The following conclusions were made from the data collected on the CST-939 sorbent: The sorbent efficiency and capacity are much greater at 343{degrees}C (650{degrees}F) than at 871{degrees}C (1,600{degrees}F). The sorbent efficiency and capacity are much greater in the presence of the more highly-reducing Shell gas than with the less-reducing KRW gas. The sorbent showed tremendous capacity for sulfur pickup, with actual loadings as high as 21 weight percent. Oxidative regeneration at 871{degrees}C (1,600{degrees}F) appeared to decompose sulfate; however, unusually high SO{sub 2} release during the second sulfidations and/or reductive regenerations indicated incomplete regeneration. The average crush strength of the reacted sorbent did not indicate any loss of strength as compared to the fresh sorbent. Superior sorbent performance was obtained in the presence of simulated Shell gas at 538{degrees}C (1,000{degrees}F)