分别以氨水和尿素溶液作为还原剂,在管式反应器上详细研究了CO含量对烟气SNCR(选择性非催化还原)脱硝性能的影响。结果表明,CO含量增加导致:(1)SNCR脱硝温度窗口和最佳脱硝温度向低温方向移动,同时脱硝温度窗口宽度变窄、最大脱硝效率降低,尤其是以氨水作为还原剂时更为突出;(2)N2O排放的峰值升高;当以尿素溶液作还原剂时,N2O排放温度窗口主要向低温方向扩展;当以氨水作还原剂时,N2O排放温度窗口向低温和高温两个方向扩展;(3)NH3及HNCO残留量曲线向低温方向移动。维持相同的φ(CO)/φ(urea),氨氮比增加将导致最佳脱硝温度略微降低。氨氮比或氧含量的变化对NOx、N2O、NH3及HNCO的排放趋势没有影响。
An experimental study on the effects of CO content on selective non-catalytic reduction (SNCR) of NOx was performed in a quartz tube reactor, using ammonia and urea solution as N-agent. The results showed that as the CO content increased: (1) Both the SNCR temperature window and the optimal DeNOx temperature shifted towards a lower temperature. Simultaneously, the temperature window was narrowed and the optimal DeNOx efficiency decreased, especially when using ammonia as reductant. (2) The peak of N2O emission became higher. When using urea solution as the reductant, N2O emission temperature window extended towards a lower temperature mainly. In the case of ammonia, N2O emission temperature window extended to both higher and lower temperatures. (3) The slip emission curves of both NH3 and HNCO shifted to a lower temperature. When setting φ(CO)/φ(urea) constant, the,optimal DeNOx temperature dropped slightly with the increase of ratio of ammonia to nitrogen in the feed (β), and there was no change of the emission regime profiles about NOx, N2O, NH3 and HNCO as β or oxygen content changed.