水蒸气对选择性非催化还原反应影响的实验研究

Investigation on Effects of Water Vapor on Selective Non-Catalytic Reduction of NO_x

在一管式石英反应器上实验研究水蒸气对选择性非催化还原过程脱硝效率、N2O排放、NH3泄漏等因素的影响,实验采用氨气为还原介质。结果表明,水蒸气量增加时:最佳脱硝温度、脱硝温度窗口将向高温方向偏移,温度窗口宽度将逐渐增大,最佳脱硝效率持续升高,但两者的增长幅值都持续降低;NH3泄漏曲线向高温方向稍有移动,N2O排放曲线有所升高,但升高绝对值很小。水蒸气量相同时:温度低于900℃区域,较低氨氮比时的水蒸气脱硝促进作用更显著;温度在1100℃附近时,较高氨氮比时的水蒸气脱硝促进作用更有效;温度高于1000℃但低于1100℃附近区域,水蒸气对较高氧含量工况的脱硝促进作用更为明显。

Experimental study on the influences of water vapor content on selective non-catalytic reduction （SNCR） using ammonia gas was carried out in a quartz tube reactor. The experimental results show that when the water vapor content increases： the optimum NOx reduction temperature and the NOx reduction temperature window both shift towards a higher temperature, the width of NOx reduction temperature window is widened and the optimal NOx reduction efficiency increases. The slip curves of NH3 shift little to a higher temperature and the emission curves of N2O would be somewhat higher. While there is the same water vapor content： Within temperature region lower than 900℃, the promotive effect of water vapor on NOx reduction is more notable as the ratio of NH3 to NOx is smaller. When temperature is about 1 100℃, the promotive effect of water vapor on NOx reduction is more effective as the ratio of NH3 to NOx is larger. The promotive effect of water vapor on NO. reduction is more evident as the oxygen content is larger around temperature region which is between 1 000℃ and 1 1O0℃.