燃煤烟气中喷氨脱硝对氧化亚氮(N_2O)生成的影响

The Effect of De-NO_x Process with Ammonia Injection on N_2O Formation in Flue Gas

实验研究发现,喷氨脱硝过程中是否会产生大量的N_2O,在很大程度上取决于喷氨处的烟气的成分,氧化性气氛有利于N_2O的产生.对喷氨脱硝的均相化学反应过程进行的动力学模拟表明,在混合良好的还原性烟气中喷入氨气不会导致N_2O排放量大幅度增加,但如果喷入的氨气与烟气和空气混合不良,或者烟气中存在由NH_3转化的氰基成分,那么N_2O的排放量会有所增加.

Although N2O emission from pulverized coal combustion is very low because of the high combustion temperature, the de-NOx process with ammonia injection can result in an increase of N2O emission under certain conditions. Experiments show that the N2O formation with ammonia injection depends on the composition of flue gas, and an oxidizing atmosphere is favorable to the formation. It is shown by kinetic modeling on homogeneous chemical reaction that a good mixing of reductive flue gas, ammonia and air will not result in a large amount of N2O emission. However, if there appears in the flue gas the cyano-constituent converted from ammonia, the N2O emission will increase. It is concluded that the de-NOx process with ammonia injection can still be used if ammonia is injected into a well mixed and completely combusted flue gas.