Processes of formation and transformation of sulfur oxides during combustion of coals and coal-based compositions

The article presents the analysis of potential mechanisms of formation and neutralization of sulfur oxides in coal combustion products. Based on the generalization of the known studies and the performed experiments, a diagram has been developed that demonstrates the main stages of the formation and conversion of sulfur oxides during thermal conversion of coals. Temperature ranges for the conversion of pyrites and sulfides, the formation of sulfur oxides, their reaction with an oxidizer and other gases have been determined. The performed multicriterial analysis has revealed the most promising fuel mixtures. The approaches aimed at sequestering sulfur oxides by the combined reactions of coal and biomass pyrolysis products, as well as water, are described. The technological concept for sequestering sulfur oxides in flue gases is presented.