Sulfur Dioxide → Magnesium bisulfite

Participants

Reaction Steps

U.S. Pat. No. 4,388,238 to Abrams, et al. describes how sulfur dioxide is contacted with a magnesium sulfite solution in a scrubbing zone at a pH in the range of about 6 to 7.5 in order to produce magnesium bisulfite. It also teaches providing a minor regeneration stream which is subjected to oxidation to oxidize bisulfite and sulfite to sulfate. This reference also teaches the use of a type S hydrated dolomitic lime for the spray dryer at a weight percent of 3-15% suspended solids and at a stoichiometric ratio of 1.1 to 1.5 and injected at a temperature of 145° to 165° F. The product is calcium sulfite and sulfate, magnesium sulfite and sulfate, unreacted lime, and flyash. However, the presence of calcium sulfite and sulfate and magnesium sulfate is undesirable.

Provenance & Evidence