Removal of sulfur during the combustion of coal by adding limestone

The main objective of this paper has been to formulate a mathematical model for the study of the absorption of SO/sub 2/ in limestone, based on a detailed description of the fundamental chemical and physical steps. In particular, an original chemical mechanism has been proposed. It hypothesizes that the sulfur dioxide is oxidized to sulfur trioxide in the combustion chamber because of the catalytic action of tract compounds such as V/sub 2/O/sub 5/ and Cr/sub 2/O/sub 3/ in the coal. Then SO/sub 3/ diffuses into the calcium oxide particles to form calcium sulfate. This mechanism seems to account for the behavior of the desulfurization efficiency in terms of the parameters of interest, as found in experimental work.