Influence of Temperature Change on Conversion Characteristics of NOx in the Reburning Zone

Low NO_x reburning combustion is suitable for energy structure dominated by coal in our country, since it is a cost-effective NO_x control technology. Temperature condition is one of the important influential factors of NO_x conversion in reburning zone. The influence characteristics were studied on gas reactor system. Biomass gasification gas was chosen as reburning fuel, and the simulated flue was prepared with N₂, O₂ and NO. The results show that NO conversion efficiency increases in the beginning, then decreases, and again increases sharply with the increase of temperature. When residence time is 0.6s, the higher temperature of reburning atmosphere, the higher NO conversion efficiency can be achieved under lower excess air ratio. But for higher excess air ratio, there exits the optimum temperature, which can result in a maximum conversion efficiency of NO. The results also provide a basis for the technology improvement of Low NO_x reburning combustion.