NH_3选择性非催化还原NO的实验研究

在电加热的管式反应炉上进行了NH3选择性非催化还原(SNCR)NO气相均相反应的实验研究,结果表明:最佳脱硝温度约为925℃,最大脱硝效率约为83%。综合考虑脱硝效率、NH3漏失和运行成本,最佳氨氮摩尔比为1.5。NO初始浓度从300μL/L降到100μL/L,脱硝效率由83%降到57%,但是脱硝后NO的排放浓度几乎不变,约为50μL/L。当O2浓度从1%增加到10%,脱硝效率由91%降到75%,反应后剩余的NH3由43μL/L减少到10μL/L。925℃时SNCR反应完全进行需要1s以上的停留时间,而1000℃时只需0.4s。

Experimental Study of Selective Non-catalytic Reduction of NO by NH_3

On an electrically-heated tubular reaction stove, an experimental study was performed of a gas phase homogeneous reaction of NH_3 to selectively and non-catalytically reduce NO. The test results show that the optimum denitration temperature is around 925 ℃ with the maximum denitration efficiency being 83%. With the denitration efficiency, NH_3 leakage loss and operation cost being taken into account as a whole, the optimum ammonia mol ratio is 1.5. When the initial concentration of NO decreases from 300 μL/L to 100 μL/L, the denitration efficiency will go down from 83% to 57%. The NO_x emissions concentration after the denitration, however, is about 50 μL/L, almost without any changes. When the oxygen concentration increases from 1% to 10%, the denitration efficiency will decline from 91% to 75% and the remaining NH_3 after the reaction will diminish from 43 μL/L to 10 μL/L. At 925 ℃, to complete a SNCR (selective non-catalytic reduction) reaction process will require more than 1 second of residence time, while at 1 000 ℃, the process will need only 0.4 seconds.