Patent ID: 10570825

Abstract:
A fuel, an oxidant, and a diluent can be introduced to a combustion zone, wherein the oxidant comprises air, oxygen-enriched air, or oxygen-lean air. At least a portion of the fuel can be combusted to produce an exhaust gas comprising, nitrogen, nitrogen oxides, and carbon monoxide. The exhaust gas can be expanded to produce mechanical power and an expanded exhaust gas. A concentration of at least one of oxygen, hydrogen, nitrogen oxides and carbon monoxide, in the exhaust gas or the expanded exhaust gas or both can be determined, and an amount of the oxidant or the fuel introduced to the combustion zone, or both, can be adjusted based on the determined concentration to produce an exhaust gas containing a combined amount of oxygen and carbon monoxide of less than about 2 mol % and a nitrogen concentration ranging from 20 mol % to 75 mol %. The diluent to the combustion zone can include at least a portion of the exhaust gas containing a combined amount of oxygen and carbon monoxide of less than 2 mol % and a nitrogen concentration ranging from 20 mol % to 75 mol %.