Abstract: A method of scrubbing a gaseous mixture comprising NO and SO.sub.2 said method comprising providing a scrubbing solution, said scrubbing solution comprising a solvent and a solute wherein said solute comprises Fe.sup.++ and S.sub.2 O.sub.3.sup.-,scrubbing said gas containing nitric oxide with said scrubbing solution.

Abstract: A method for removing hydrogen sulfide and nitric oxide from gaseous mixtures by adjusting the mol ratio of hydrogen sulfide to nitric oxide to a value from about 0.5 to about 1.1 and thereafter mixing a free oxygen containing gas with the gaseous mixture to provide a quantity of oxygen greater than about 0.5 mols of oxygen per mol of nitric oxide in the gaseous mixture. Either hydrogen sulfide or nitric oxide may be removed substantially completely.

Abstract: A method for producing ammonia and hydrogen sulfide in a molar ratio (NH.sub.3 /H.sub.2 S) from about 2.8 to about 3.7 from an aqueous ammonium thiosulfate solution by a method consisting essentially of: (a) contacting the aqueous ammonium thiosulfate solution with hydrogen sulfide at a temperature from about 260.degree. to about 360.degree. F. (125.degree. to 182.degree. C.) at a pressure greater than 100 psig to react at least about 70 percent of the thiosulfate to produce an aqueous solution containing ammonium polysulfide; and (b) heating the resulting aqueous ammonium polysulfide solution to produce ammonia and hydrogen sulfide in a molar ratio (NH.sub.3 /H.sub.2 S) from about 2.8 to about 3.7 and sulfur.

Abstract: A method for converting calcium sulfoxy compounds selected from the group consisting of CaSO.sub.x and Ca(HSO.sub.x).sub.2 where x is 3 or 4, into calcium carbonate by a method consisting essentially of: (a) converting the Ca(HSO.sub.x).sub.2 compounds into CaSO.sub.x compounds by reacting the CA(HSO.sub.x).sub.2 compounds with CaCO.sub.3 in the presence of water; (b) reacting the CaSO.sub.x compounds with NH.sub.3 and CO.sub.2 in the presence of water to produce NH.sub.4 HSO.sub.x and CaCO.sub.3 ; (c) separating the NH.sub.4 HSO.sub.x and CaCO.sub.3 ; (d) reacting the NH.sub.4 HSO.sub.x with H.sub.2 S to produce ammonium polysulfide (NH.sub.4).sub.2 S.sub..omega. wherein .omega. is from 1 to about 4; (e) decomposing the ammonium polysulfide to produce NH.sub.3, H.sub.2 S, elemental sulfur and water; and (f) recovering the elemental sulfur from the NH.sub.3, H.sub.2 S and water.

Abstract: A method for desulfurizing a gaseous mixture such as flue gas by sequentially contacting the gaseous mixture with an aqueous solution containing ammonium thiosulfate in a first zone; an aqueous solution containing ammonia and ammonium thiosulfate in a second zone; and an aqueous solution containing ammonium thionate or thionic acid in a third zone. The sulfur is optionally recovered as elemental sulfur.

Abstract: An improvement in regenerative SO.sub.2 scrubbing systems which use sodium, potassium or ammonium carbonate to react with the SO.sub.2 to form sulfite, wherein a thiosulfate-rich aqueous solution of the carbonate is used to prevent oxidation of the sulfite to sulfate; to serve both as a source of the carbonate and as a source of sulfite-reducing agent; and finally to increase the salt concentration in the SO.sub.2 absorbent solution, to thereby permit operation of the scrubbing system at higher temperatures than those normally employed.

Abstract: An improvement in wet regenerative SO.sub.2 scrubbing systems using a sulfite-forming additive wherein a thiosulfate-rich aqueous solution is used to prevent oxidation of sulfite to sulfate, to serve as a source of the sulfite-forming additive, and also to increase the salt concentration of the SO.sub.2 absorbent, to thereby permit operation of the scrubbing system at higher temperature.