Abstract: A combustion system with provisions to minimize undesired exhaust products including carbon monoxide, incompletely burned fuel, and oxides of nitrogen. Air entering the combustion zone of the combustion apparatus is mixed with a relatively large amount of recirculated combustion products, preferably about twice the weight of the fresh air entering the combustion zone. The combustion products which are recirculated are cooled by heat exchange with air flowing to a dilution zone of the combustion apparatus where the combustion products and air are mixed to provide the high temperature gas output of the system which is the motive fluid of a gas turbine.The recirculated combustion products are cooled to reduce temperature in the combustion zone and thereby nitrogen oxide formation and the heat extracted from the recirculated combustion products is transferred to the dilution air. The combustion products delivered from the combustion zone to the dilution zone may be diverted ahead of or after the heat exchange.