Method for reducing NOx from exhaust gases produced by industrial processes

A method for reducing NOx in an exhaust gas, comprising contacting the exhaust gas with a reductant effective for NOx reduction under autocatalytic conditions at a location in the exhaust gas flowpath where the exhaust gas is autothermally heated to achieve said autocatalytic conditions using one or more hydrocarbons, and wherein the reductant comprises urea.

A method for reducing NOx in an exhaust gas, comprising contacting the exhaust gas with a reductant effective for NOx reduction under autocatalytic conditions at a location in the exhaust gas flowpath where the exhaust gas is autothermally heated to achieve said autocatalytic conditions using one or more hydrocarbons, wherein the reductant comprises HNCO.

A method for determining if a pollutant in an exhaust gas stream has been depleted by an autocatalytic process, comprising:

• introducing one or more hydrocarbon(s) into the exhaust gas stream at a first location to autothermally heat the exhaust gas in the presence of a reductant effective for reduction of NOx in the exhaust gas;
• measuring CO at a second location in the exhaust gas stream downstream from the first location;
• determining if the level of CO at the second location exceeds a predetermined level that corresponds to a final temperature of the exhaust gas sufficient for autocatalytic depletion of the pollutant.

A method for determining a level of NOx depletion by an autocatalytic process in an exhaust gas stream, comprising:

• contacting the exhaust gas stream with one or more hydrocarbon(s) and one or more reductant(s) effective for reduction of NOx at a first location so that the exhaust gas is autothermally heated to autocatalytically deplete NOx in the gas stream;
• measuring the amount of NOx at a second location in the exhaust gas stream downstream from the first location.