SO2 Pickup by Limestone and Dolomite Particles in Flue Gas

Abstract

An investigation was made of the reaction between SO2 and limestone and dolomite particles in flue gas. Reaction data were generated by exposing the particles to flue gas in a dispersed-phase reactor that simulates localized boiler-furnace conditions. Variables included in the study were residence time, temperature, particle size, SO2 concentration, and chemical state of the stone. A model is hypothesized for the SO2 - particle reaction that is consistent with the experimental data. The hypothesis states that the initial reaction products are sulfites, and that as the particle temperature rises above about 1400 deg F, SO2 is lost by thermal decomposition of the sulfite. Concurrently the sulfite can oxidize and/or disproportionate to form sulfate.