The Retention of Sulfur in Fly Ash from Coal-Fired Boilers

Abstract

Graphical and statistical analyses of the study presented showed that the sulfur retention in fly ash emitted from coal-fired boilers is a function of the alkaline metal oxide content of the fly ash. Further, it was shown that the correlations between sulfur retention and the relative concentrations of the specific alkaline metal oxides were improved significantly, when the data sets were reduced to include only those data obtained from coal-fired boilers which had similar combustion characteristics and particulate collection systems. Excellent correlations were obtained for the wide range of fly ashes that were studied, but the range of observed values of sulfur retention at any specific value of alkaline metal content is greater than a factor of two in most cases. This variation is due to the combined effects of many factors including boiler characteristics, particle size effects, and other mass transfer parameters. (JMT)