Experimental study on the generation characteristics and emission patterns of nitrogen oxides in clean coal
In order to study the generation characteristics and emission laws of nitrogen oxides in civil clean coal,the effects of combustion temperature,combustion atmosphere,oxygen concentration,primary air ratio,simulated flue gas recirculation,and semi coke blending ratio on nitrogen oxide emissions from clean coal were studied using a tube furnace combustion experimental device.The results show that within the range of 900~1 200 ℃,NOx decreases linearly with increasing combustion temperature;Under O2/N2 and O2/CO2 atmospheres,the nitrogen conversion rate generally decreases with the increase of oxygen concentration,and the overall nitrogen oxide generation trend increases with the increase of primary air ratio;The use of flue gas recirculation is beneficial for reducing nitrogen conversion rate,but only when the proportion of flue gas recirculation is large,nitrogen oxides show a significant decrease;Half coke was prepared at three temperatures:600 ℃,800 ℃,and 1 000 ℃.When the coking temperature was 600 ℃,the nitrogen oxide emissions were the lowest when half coke was mixed with shaped coal,and the nitrogen conversion rate decreased with the increase of half coke ratio.