Removal of SO₂from Low Sulfur Coal Combustion Gases by Limestone Scrubbing

Abstract

An analysis of the limestone scrubbing process for SO/sub 2/ removal was carried out. It was found that low concentrations of SO/sub 2/ in power plart flue gas (<1,000 ppM) tend to minimize the solidliquid mass transfer resistance, and the S02 absorption process approaches gas phase cortrol. Gas phase cortrol has a favorable effect on the important parameters of limestone blinding, scaling, slurry pH stability, sulfite oxidation, solids settling, and slurry recirculation rate. It is concluded that operational reliability increases for lower SO/sub 2/ gas concentrations. A discussion of scrubber designs and corresponding mass transfer coefficients for limestone scrubbing is given, and a process design procedure is presented. (auth)