O_2/CO_2气氛下CO对煤焦异相还原NO影响的研究

Investigation on Effect of CO on NO Heterogeneous Reduction With Char in O_2/CO_2 Atmosphere

为揭示O_2/CO_2燃烧过程中高浓度的CO对煤焦异相还原NO的影响,在1073 K温度下使用山西褐煤在卧式炉上进行了实验。分别对O_2/CO_2浓度比及CO浓度下NO的还原特性进行详细实验研究。研究结果表明:在O_2/CO_2气氛下,O_2浓度为30%时具有较高的还原率;相同O_2浓度下O_2/CO_2气氛较空气气氛NO还原率高,表明在CO存在的条件下,高浓度的CO_2会促进NO的还原;当CO浓度从1.5%逐渐升高时,NO的还原率逐渐降低,到CO浓度为5%时,NO还原率比没有加入CO时还要低,而在空气气氛下CO浓度的变化对NO的还原率影响较小。

To reveal the effect of high concentrated CO on NO heterogeneous reduction with char during the process of O2/CO2 combustion, combustion experiments of Shanxi lignite were carried out on a horizontal furnace at 1073 K. NO reduction characteristics under different O2/CO2 concentration and CO concentration were discussed. The results showed that high efficiency of NO reduction had been obtained when O2 concentration was 30% in O2/CO2 atmosphere. The reduction efficiency of NO was much higher in O2/CO2 atmosphere than that of in air at the same O2 concentration, which indicated that high CO2 concentration will promote the catalytic reduction of NO on char surface with the presence of CO. Reduction efficiency of NO decreased as the concentration of CO rose from 1.5%. However, the reduction efficiency of NO under 5% CO was even lower than that of no CO was added. In addition, NO reduction was less affected by the variation of CO concentration in air condition.