Removal of sulfur and nitrogen oxides with aqueous absorbent

摘要

Sulfur oxides and nitrogen oxides are removed from flue gas by scrubbing the flue gas with an aqueous ammoniacal solution containing ammonium thiosulfate and either ammonium sulfite or ammonium hydroxide. The presence of ammonium thiosulfate in the absorbent solution also inhibits the oxidation of sulfur dioxide to hexavalent sulfur. The scrubber effluent solution or a portion thereof is acidified in order to liberate sulfur dioxide in a concentrated stream.