Process for reducing NOx and/or SOx in feed gas streams

Claim 1

In a process for removing SO x components from an industrial stack gas stream also comprising O 2 and water vapor, said water vapor being present in a concentration in excess of three times the molar percentage of SO x components, wherein said SO x components are converted to H 2 s, which H 2 s is subsequently removed, the improvement comprising: 1. contacting said stack gas stream with a solid carbonaceous material in a combustion zone maintained at a peak temperature between about 900° and 1600° F so as to (a) convert at least some of said SO x components to H 2 S and COS, (b) consume essentially all of said O 2 in combustion of said carbonaceous material, and (c) consume a portion of said water vapor by reaction with said carbonaceous material to form CO and H 2 , thereby producing a gaseous effluent of reduced SO x content but containing water vapor, H 2 S, COS, residual SO x components, and at least sufficient H 2 and CO for the reduction of said residual SO x components to H 2 S in step (2) hereinafter; 2. contacting said gaseous effluent from step (1) with a solid catalyst comprising cobalt and molybdenum at a temperature between about 300° and 800° F so as to (a) reduce at least some of said residual SO x components to H 2 S and (b) convert essentially all of said COS and H 2 S and essentially all of said CO to CO 2 and H 2 by reaction with water vapor; 3. withdrawing a purified gas stream containing H 2 S as essentially the only gaseous sulfur component therein; and 4. removing said H 2 S from said purified gas stream.