PROCESS FOR PRODUCING SULFUR FROM SULFUR DIOXIDE

A process for reducing sulfur dioxide wherein ammonia is used as the reducing agent. The reduction may be accomplished either thermally or catalytically and the principal products obtained will be elemental sulfur and/or hydrogen sulfide, depending principally upon the particular conditions and relative reactant concentrations actually employed. The sulfur dioxide may be derived from flue gas or from any other source. The ammonium salts that are formed when ammonia or an aqueous ammoniacal solution is also used as an absorbent are decomposed at an elevated temperature to obtain, as products, elemental nitrogen and elemental sulfur or hydrogen sulfide or both. The thermal reduction of sulfur dioxide with ammonia is the subject of the claims of this application while the process for the removal of sulfur oxides from a gas stream containing same using ammonia as both absorbent and reducing agent is the subject of claims of a divisional application.