KINETICS OF DESULFURIZATION OF HOT FUEL GAS WITH CALCIUM-OXIDE - REACTION BETWEEN CARBONYL SULFIDE AND CALCIUM-OXIDE

In developing coal gasification processes, removal of the sulfur compounds has been of great concern because of their detrimental effects on air quality, corrosion of equipment, and poisoning of the catalysts used in the processes. The sulfur compounds existing in the fuel gases are mainly hydrogen sulfide (H2S) and carbonyl sulfide (COS) (1). Over the past few years, work on the use of metal oxides as sorbents for H2S removal has been reported in the literature, e. g., in ref 2-5. In particular, studies have been made on the kinetics of the reaction between CaO and H2S (4-7). It is known that H2S exists in a greater concentration than does COS in the fuel gases from the coal gasifiers. The thermodynamic equilibrium ratio of H2S over COS is normally high under the gasification conditions. For example, the ratio is about 50 for the Lurgi process. Nevertheless, the equilibrium is not rapidly reached and, therefore, significant amounts of COS do exist in the raw gases from gasifiers. In addition, COS also exists in the effluents of other industrial processes. For the commercially available coal gasifiers, the typical concentration of COS is 0.01% (1). © 1979, American Chemical Society. All rights reserved.