在一维管式炉上进行高温下NH3还原NOx特性实验研究，并基于化学反应动力学模型对实验工况进行模拟计算，分析在近零氧工况下NH3/NOx反应过程中关键基元反应及主要活性基团变化规律，探究高温下氨还原NOx反应机理。结果表明：在无氧或者氧气体积分数为0.1%工况时，反应温度窗口明显向高温偏移，NH3/NOx还原反应进行的拐点温度为1 100 ℃，反应过程中关键的基元反应为NH2/NOx还原反应，温度对这组基元反应的一阶敏感性系数决定了最佳反应温度窗口；OH与NH2自由基是反应中重要的活性基团，其浓度的积累也影响反应温度窗口，无氧工况下最佳反应温度窗口为1 300~1 400 ℃；无氧工况下NH2自由基主要由3条反应路径还原NOx，NH与NNH自由基是最重要的中间产物，而HNO的存在会造成NOx质量浓度增加。

The NOx reduction characteristics by NH3 at high temperature was studied experimentally in a one dimensional tubular furnace, and the experimental conditions were simulated based on the chemical reaction kinetics model. The varieties of key elementary reactions and main active groups in the NH3/NOx reaction process under near zero oxygen conditions were analyzed, and the reaction mechanism of NOx reduction by NH3 at high temperature was explored. The experimental results show that the reaction temperature window obviously shifts to high temperature zone under anaerobic condition or when the oxygen volume fraction is 0.1%, and the inflection point temperature of NH3/NOx reduction reaction is 1 100 ℃. The key elementary reaction in the reaction process is NH2/NOx reduction reaction, and the optimal reaction temperature window is determined by the influence of temperature on the firstorder sensitivity coefficient of this group reactions; OH and NH2 free radical are important active groups in the reactions, and their concentration accumulation also affects the reaction temperature window. The optimum reaction temperature window under anaerobic condition is 1 300 to 1 400 ℃; under anaerobic conditions, NOx is reduced by NH2 free radical mainly through three reaction paths, NH and NNH free radicals are the most important intermediates, and the presence of HNO will increase the NOx emission mass concentration.

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