Method of thermal NOx reduction in catalytic combustion systems

A method for operating a catalytic combustor, comprising:

• catalytically combusting a fuel-air mixture in a combustor, wherein at least a portion of the fuel-air mixture is combusted in a homogeneous combustion wave within a post catalyst burnout zone located downstream of a catalyst to form hot combustion gases;
• and
• controlling the residence time of the hot combustion gases within the post catalyst burn out zone to control the production of thermal NOx, wherein the residence time is controlled by controlling the location of the homogeneous combustion wave with respect to an outlet of the combustor.

A method for operating a catalytic combustor, comprising:

• catalytically combusting a fuel-air mixture in a combustor, wherein at least a portion of the fuel-air mixture is combusted in a homogeneous combustion wave within a post catalyst burnout zone located downstream of a catalyst to form hot combustion gases;
• and
• controlling the residence time of the hot combustion gases within the post catalyst burn out zone to control the production of thermal NOx, wherein controlling the residence time includes adjusting the catalyst outlet gas temperature to control the delay time for ignition of the fuel in the homogenous combustion wave.

The method wherein,

• the hot combustion gases have a temperature above 1450° C during the residence time, and
• the residence time is controlled such that the production of NOx is below approximately 3 ppm and the production of CO is below approximately 100 ppm.