Methods of reducing NO/sub chi/ and SO/sub chi/ emissions from combustion systems

This patent describes a process for selectively reducing nitrogen oxides in combustion effluent streams. It comprises the steps of: introducing cyanuric acid into a gaseous decomposition zone wherein the decomposition zone is substantially oxygen deficient and contains CO and H/sub 2/0, and is maintained at a temperature in the range of from approximately 1000{sup 0}F. to approximately 3000{sup 0}F.; allowing the cyanuric acid sufficient residence time within the decomposition zone to allow for substantial mixing of the cyanuric acid and gaseous species within the decomposition zone; introducing the resulting gaseous mixture from the decomposition zone to a reaction zone containing combustion effluents, the reaction zone having an excess of oxygen; and allowing the gaseous mixture from the decomposition zone sufficient residence time within the reaction zone to achieve substantial reduction of the nitrogen oxides within the combustion effluents.