Desulphurization of coal-derived char using mixtures of steam and methane

Results of a laboratory scale experimental study on the desulphurization of coal char by steam-methane mixtures are presented. The char was prepared from a high sulphur, medium volatile, bituminous coal. The variables studied were temperature and reacting gas composition. The concentration of sulphur, specific surface area, pore size distribution and char reactivity were determined before and after the desulphurization reaction. A significant amount of sulphur was removed when coal char was reacted with 3-20 mol% steam in steam-methane mixtures in the temperature range 703-823 K. Carbon gasification was effectively eliminated by this technique. Although small increases in both the specific surface area and pore volume occurred, the reactivity of the char was practically unaffected by the desulphurization reaction.