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在固定床反应器上考察了高温下不同氧浓度气氛下NO-煤焦还原反应的还原效果,并采用XPS分析了不同氧浓度预处理后的煤焦表面的含氧官能团。研究结果表明,高温下氧气对于NO-煤焦还原反应依然有显著的促进作用,也同样存在临界氧浓度(0.25%)的现象,比低温下临界氧浓度(1%)有所提前。由XPS分析结果发现,高温下氧气对煤焦表面的影响是产生促进NO还原的表面含氧官能团(C(O)),适量的氧气浓度能形成饱和的C(O)活性位,使得还原效果达到最佳。随着温度的升高,C(O)的总量略有减少。有可能是温度过高致使煤焦表面的C(O)极易达到饱和,多余的氧气以O的形式排出。
The reduction effect of NO-char reduction under different oxygen concentrations at high temperature was investigated on a fixed-bed reactor. The oxygen functional groups on the surface of char were pretreated with different oxygen concentrations by XPS. The results show that oxygen still has a significant effect on NO-char reduction at high temperature, and the critical oxygen concentration (0.25%) also exists, which is earlier than the critical oxygen concentration (1%) at low temperature. The results of XPS analysis showed that the effect of oxygen on the surface of coal char under high temperature was due to the production of oxygen-containing functional groups (C (O)) that promoted the reduction of NO, and the oxygen concentration could form saturated C (O) Reach the best. As the temperature increases, the total amount of C (O) decreases slightly. It is possible that the temperature is too high to make C (O) on the char surface extremely easily saturated, and the excess oxygen is discharged as O.