Analysis of the flame formed during oxidation of pulverized coal by an O2CO2 mixture

Pulverized coal combustion with oxygen and recycled flue gas constitutes a promising system to recover CO2 from the exhaust gases of boilers. Our previous combustion tests on this system suggest emissions of smaller amounts of NOx than in conventional combustion and reduced ignition stability of the burner. In order to improve the combustibility of the O2/CO2-pulverized-coal burner, numerical simulations and combustion tests were performed. An oxygen-injection nozzle was added to the burner. Simulation results predicted the effectiveness of direct oxygen injection and were confirmed qualitatively by bench-scale combustion tests on gas temperatures.