Analytical and experimental research for decreasing nitrogen oxides emissions

This paper presents analytical as well as experimental research methods focused on decreasing nitrogen oxides formation while burning natural gas in a furnace of an 80 MW boiler. For this work different methods are investigated such as: the recirculation of smoke gases in the burners both in hot air and fuel; injection of water in the burning zone with the simultaneous decrease of the excess air coefficient into the burning zone including the organization of two stage burning in a furnace. The effects of combining these methods are investigated in order to obtain the maximum reduction in the concentration of nitrogen oxides exiting the burning zone. Operating modes of the boiler with the recirculation of smoke gases in hot air are used as a reference in calculating NOx formation and NOx emissions are measured from the stack of the boiler.