Research on reaction mechanism between NO and NH_i during low NO_x gas reburning

The reaction mechanisms between free radicals NO and NH_i were studied using quantum chemical density functional theory (DFT) and rate constant for each reaction was calculated combining with classical transition state theory in this paper. The results show that there are six different reaction channels for free radicals NO and NH₂, and the products are N₂+H₂O, N₂O+H₂ and N₂H+OH. The optimum reaction channel is NO+NH₂→→N₂+H₂O from the views of energy change and reaction rate. Similarly, N₂+OH, N₂O+H and N₂H+O will be produced by seven different reaction channels between free radicals NO and NH, and the optimum reaction channel is NO+NH→→N₂+OH. So it is easier for free radical NH reacting with NO to generate N₂ than NH₂. Therefore, an important conclusion was got that the lower NO_x emission could be obtained by making NH₂ turn to NH in the actual operation.