Abstract: Process for the removal of sulfur oxides from sulfur oxide-containing gas with simultaneous production of ammonium sulfate. The process is carried out by first passing hot sulfur oxide-containing gas through a prescrubber wherein the gas contacts saturated aqueous ammonium sulfate liquor which is recycled in the prescrubber, followed by passing the prescrubbed gas through an absorber wherein the prescrubbed gas contacts dilute aqueous ammonium sulfate liquor. The sulfur oxide in the sulfur oxide-containing gas is absorbed by the dilute aqueous ammonium sulfate liquor in the absorber, and scrubbed gas is removed from the absorber. The dilute aqueous ammonium sulfate liquor is treated with ammonia and air and the absorbed sulfur dioxide is converted to ammonium sulfate in the liquor. The dilute ammonium sulfate liquor is recycled into contact with the prescrubbed gas in the absorber.

Abstract: Process and apparatus for the removal of sulfur oxides from sulfur oxide-containing gas with simultaneous production of ammonium sulfate. The process is carried out in a single vessel having an ammonium sulfate scrubbing zone; an ammonium sulfate liquor reservoir having a neutralization zone, a sulfur oxide oxidation zone, and a product removal zone; and a scrubbed gas removal zone. The sulfur oxide-containing gas is introduced into the ammonium sulfate scrubbing zone and passes countercurrent to droplets or a spray of ammonium sulfate liquor. The ammonium sulfate liquor absorbs the sulfur oxide in the scrubbing zone, and the liquor having the absorbed sulfur oxide therein collects in the ammonium sulfate liquor reservoir where aqueous ammonia is introduced into the neutralization zone and an oxygen-containing gas is introduced into the sulfur oxide oxidation zone.