Power generation wherein sulfur and nitrogen oxides are removed

Claim 1

Improved process for the generation of power through the extraction of heat generated from the combustion of sulfur bearing carbonaceous fuels which comprises: a. combusting the sulfur bearing carbonaceous fuels in the combustion zone of the boiler maintained at a temperature from about 2000° to about 3000° F. of a power generator in a deficiency of air to form a reducing flue gas stream of corresponding high temperature comprising carbon dioxide, carbon monoxide, hydrogen, sulfur dioxide, the oxides of nitrogen and water, the hydrogen and carbon monoxide content of the formed high temperature reducing flue gas stream being at least from about 30 to about 60% in excess of the stoichiometric amount required to reduce the formed sulfur dioxide to hydrogen sulfide; b. cooling the high temperature reducing flue gas stream in said boiler to a temperature of from about 300° to 800° F., to extract heat values therefrom and thermally reduce a portion of the oxides of nitrogen to a nitrogen compound selected from the group consisting of nitrogen, ammonia and mixtures thereof, and a portion of the sulfur dioxide to a mixture of hydrogen sulfide and carbonyl sulfide; c. catalytically converting by reduction residual sulfur dioxide to hydrogen sulfide, the oxides of nitrogen to a nitrogen compound selected from the group consisting of nitrogen ammonia and mixtures thereof and hydrolyzing at least part of the carbonyl sulfide to hydrogen sulfide by passing the cooled reducing flue gas stream through a catalytic conversion zone in the presence of a catalyst capable of converting the sulfur dioxide to hydrogen sulfide, the oxides of nitrogen to nitrogen and ammonia and hydrolyzing carbonyl sulfide to hydrogen sulfide; and d. extracting the formed hydrogen sulfide from the flue gas stream and venting the flue gas stream to the atmosphere.