Catalytic Effects of Minerals on NOx Emission from Coal Combustion

Abstract

The catalytic effects of inherent mineral matters on NO _x emissions from coal combustion have been investigated by a thermo-gravimetric analyzer (TGA) equipped with a gas analyzer. The effect of demineralization and the individual effect of Na, K, Ca, Mg, and Fe on the formation of NO _x are studied as well as the combined catalytic effects of Ca + Na and Ca + Ti. Demineralization causes more Fuel-N to retain in the char, and reduction of NO _x mostly. But the mechanistic effect on NO _x formation varies from coal to coal. Ca and Mg promote NO _x emission. Na, K, Fe suppress NO _x formation to different extents. The effect of transition element Fe is the most obvious. The combination of Ca + Na and Ca + Ti can realize the simultaneous control of sulfur dioxide and nitrogen oxides emissions.