选择性非催化还原脱除氮氧化物的影响因素分析

Analysis on Impact Factors for Removal of NO_x With Selective Non-catalytic Reduction

进行以NH3作为还原剂的选择性非催化还原(selective non-catalytic reduction,SNCR)转化氮氧化物(NOx)的试验研究。考察SNCR转化NOx的各影响因素:温度,初始NH3和初始NOx摩尔浓度的比值η,NOx体积浓度,O2体积浓度,停留时间等对NOx转化率的影响。结果表明在900～1050℃的温度范围内,SNCR可以得到较高的NOx转化率。并且在该温度范围内,η值由0.8变化到1.6时,NOx转化率显著增加。通过对试验数据进行数理分析,对SNCR转化NOx各因素的影响进行了定量研究,得出NOx转化速率与各因素的关系方程。同时考察了H2O2作为添加剂对SNCR的影响,发现H2O2作为添加剂能够降低SNCR对反应温度的要求,对NH3的逃逸有抑制作用,并从机理上给予了解释。

Research of selective non-catalytic reduction of nitrogen oxides was carried out with NH3 as reducing agent, in order to determine the effects of a series of impact factors such as reaction temperature, η（[NH3]/[NO]）, initial NOx concentration, oxygen concentration and residence time on the efficiency of NOx conversion. Results show that the efficiency of NOx conversion is high, while the reaction temperature is in the range of 900 and 1 050 ℃. At 900-1 050 ℃, the efficiency of NOx conversion was improved significantly with the increase of η from 0.8 to 1.6. The relation between NOx conversion and impact factors was also investigated through the quantitative analysis of impact factors and the mathematic statistics analysis of experimental data. In addition, the influence of H2O2 as an additive on SNCR was researched. It is shown that the efficiency of NOx conversion is improved and the NH3 slip is inhibited with the addition of H2O2. At the mean time ,the relative mechanism is discussed.