Behavior of Sulphur Compounds during Pyrolysis and Gasification of Coals

Abstract

Three kinds of coals were pyrolyzed under H2 or He and gasified under CO2 atmospheres by use of a temperature programmed reaction (TPR) method. The evolution patterns of H2S and COS, the sulphur removal and the changes of sulphur forms were investigated to examine the effects of the reaction atmosphere and the type of coal on the behavior of sulphur compounds during the reaction. It was shown that the sulphur removal and the evolution patterns of H₂S and COS varied from coal to coal. The effect of atmosphere on sulphur removal was dependent on the coal type. The changes of inorganic sulphur in coal during reaction were found to be independent on reaction atmospheres, while the behavior of the organic sulphur was strongly affected by the atmospheres especially for Datong coal. The total sulphur removal mainly depends on the amount of the organic sulphur removed. The different behaviors of the sulphur forms especially that of the organic sulphur among the coals could be attributed to the differences in structure of sulphur compounds contained in the coals.