| A laboratory-scale entrained-coal combustor was used to determine the effects of secondary swirl, stoichiometric ratio, coal type and moisture content on the formation of sulfur pollutants (SO(,2), H(,2)S, COS, and CS(,2)). Detailed local measurements within the reactor were obtained by analyzing solid-liquid-gas samples collected with a water-quenched probe. Increasing the O(,2)/coal ratio increased sulfur conversion and SO(,2) levels while H(,2)S, COS and CS(,2) levels decreased. Secondary swirl controlled the flame location and had a pronounced effect on the distribution of sulfur species formed at a stoichiometric ratio of 0.87. Decreasing coal moisture resulted in increased coal reactivity and sulfur conversion. Comparison of coal types was accomplished using a subbituminous coal containing a greater amount of pyritic sulfur and less organic sulfur than a bituminous coal. Because of differences in the relative conversion rates of organic and inorganic sulfur, the bituminous coal produced more SO(,2) and less H(,2)S, COS, and CS(,2) than the subbituminous coal. |
