采用立式高温管式炉研究了O2/CO2气氛下选择性非催化还原脱硝特性,以及添加剂碳酸钠、乙醇和氯化铁对脱硝特性的影响。实验得出O2/COe气氛下氨气脱硝适宜的反应参数:温度窗口841-1184℃,最佳反应温度约为900℃,停留时间为1~1.2s,氨氮比为1.5。增加氨氮比、停留时间和初始NO体积分数都会提高脱硝效率。氧体积分数超过3%,脱硝效率随氧体积分数升高降低明显;CO2体积分数超过20%,脱硝效率随CO2体积分数增大降幅减弱。三种添加剂均可以提高脱硝效率,碳酸钠和氯化铁可以拓宽温度窗口,使其向低温方向移动。
A corundum drop tube furnace was carried out to evaluate the characteristics of selective non-catalytic reduction (SNCR) in O2/CO2 atmosphere and the influence of additives including Na2CO3, CH3CH2OH and FeCl3 on NO reduction. Results showed that the optimum temperature window was 841-1184℃, the optimum reaction temperature was about 900℃, the optimum residence time was 1-1.2 s, and the optimum [NH3]/[NO] molar ratio was 1.5. Increasing [NH3]/[NO] ratio, prolonging the residence time and keeping higher initial NO concentration can enhance the efficiency respectively. The efficiency decreases obviously when O2 concentration is above 3% and weakly when CO2 concentration is above 20%. It can be seen that all the additives can increase the efficiency and the addition of Na2CO3 and FeCl3 are useful to widen the temperature window and shift the reaction temperature to lower points.