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: A process and system for simultaneously removing from a gaseous mixture, sulfur oxides by a solid sulfur oxide acceptor sorbent on a porous carrier, nitrogen oxides by ammonia gas and particulate matter by filtration and for the regeneration of loaded solid sulfur oxide acceptor sorbent. Finely-divided solid sulfur oxide acceptor sorbent is entrained in a gaseous mixture to deplete sulfur oxides from the gaseous mixture, the finely-divided solid sulfur oxide acceptor sorbent being dispersed on a porous carrier material having a particle size up to about 200 microns. In the process, the gaseous mixture is optionally prefiltered to remove particulate matter and thereafter finely-divided solid sulfur oxide acceptor sorbent is injected into the gaseous mixture to form an entrained bed. Ammonia gas is also injected into the exhaust gas stream. A filter separates spent solid sorbent and particulate matter from clean gas. A classifier is used to separate mixtures of spent sorbent from particulate matter.

Abstract: A process is provided for the removal of HCl and HF from a hot gas stream concurrently with the removal of sulfur compounds. The process involves the introduction of an HCl/HF sorbent such as nahcolite, sodium bicarbonate, sodium carbonate or Trona in powder form into the process stream at any one or all of four alternative locations in an amount sufficient to break down the HCl and HF into solid salts which are subsequently removed from the stream.