The effects of O2 concentration

CO2 concentration

temperature and limestone addition on SO2/NO emission characteristics from Xuzhou bituminous coal and Longyan anthracite coal combustion in O2/CO2 atmosphere were studied in a horizontal tube furnace.The results showed that the release characteristics of SO2 /NO were different between O2/CO2 combustion and air combustion

and with the same O2 concentration

SO2 and NO emissions were lower in O2/CO2 combustion than those in air combustion.As O2 concentration increased

SO2/NO emission during O2/CO2 combustion increased and with increasing CO2 concentration

SO2/NO emission decreased.In O2/CO2 atmosphere

the sulfur retention ability of limestone addition was lower than that in air atmosphere

while limestone addition could reduce the NO emission.The element composition of coal ash indicated that the reduction of SO2 during O2/CO2 coal combustion was due to improved sulfur retention ability of coal ash

and the reduction of NO was due to intensified transformation of fuel-N to other N-containing gaseous species.