Sulphur pollutant formation during coal combustion

A laboratory-scale pulverized coal combustor was used to determine the effects of secondary air swirl, stoichiometric ratio ( O 2 fuel ) , and coal type on the formation and reaction of sulphur pollutants (SO 2, H 2S, COS and CS 2). Detailed local measurements within the reactor were obtained by analysing solid-liquid-gas samples collected with a water-quenched probe. Increasing the stoichiometric ratio increased sulphur conversion and SO 2 levels, and decreased H 2S, COS, and CS 2 levels. Swirl of secondary combustion air had a pronounced effect on the distribution of sulphur species formed at an O 2-coal stoichiometric ratio of 0.8, but had very little effect at stoichiometric ratios of 0.57 and 1.17. Combustion of a bituminous coal produced more SO 2 and less H 2S, COS, and CS 2 compared with a subbituminous coal.