Apparatus and process for reduced formation of nitrogen oxides during combustion

An apparatus for reduced nitrogen oxide formation during combustion, the apparatus comprising:

• a mixing device configured to mix flue gas and oxygen to form a synthetic air for feeding to a combustion device as an oxidant for combustion, the mixing device positionable to receive the flue gas from at least one source of gas having carbon dioxide (CO2) and/or flue gas output from the combustion device that is recycled to the mixing device, the mixing device positioned to receive the oxygen from at least one source of oxygen;
• and
• wherein the synthetic air has a concentration of oxygen (O2) of between 20 mole percent (mol %) O2 and 40 mol % O2, has a concentration of nitrogen (N2) of between 20 mol % N2 and 0 mol % N2, and a concentration of CO2 of between 30 mol % CO2 and 80 mol % CO2;
• the combustion device connected to the mixing device to receive the synthetic air from the mixing device as the oxidant for combustion of a fuel, the combustion device having at least one burner and a flue gas outlet conduit for outputting flue gas formed from the combustion;
• a carbon capture apparatus positioned to receive a first portion of the flue gas from the flue gas outlet conduit to form at least one CO2 product stream having a concentration of CO2 between 90 mol % CO2 and 100 mol % CO2;
• and
• the mixing device positioned to receive a second portion of the flue gas from the flue gas outlet conduit to form the synthetic air, the synthetic air being formable such that combustion of the fuel at full rate operation with the synthetic air results in formation of nitrogen oxides (NOx) that is no more than 15 mg/Nm3 of NOx and is also greater than 0 mg/Nm3 of NOx, wherein Nm3 is a normal cubic meter;
• and
• wherein the first portion is between 30% and 70% of the flue gas and the second portion is a remaining portion of the flue gas that is not passed to the carbon capture apparatus.