CO_2气氛下煤焦对NO还原作用的试验研究

Experimental Investigation of Char Effect on NO Reduction under CO_2 Atmosphere

为了探讨O2/CO2燃烧方式下高浓度CO2对煤焦-NO还原反应的影响,使用悬浮床反应器在N2和CO2气氛下对煤焦-NO还原反应进行了试验研究。结果表明:在N2和CO2气氛下,煤阶和温度都对煤焦-NO还原反应有很大影响,煤阶越低,温度越高,焦对NO还原作用越强;流化床锅炉中较高浓度的煤焦对降低NOX排放有重要作用;与N2气氛相比,CO2气氛下高浓度的CO2会抑制NO被煤焦和CO有效还原,因此O2/CO2燃烧方式下高浓度的CO可能并非是其低NOX排放的主因。

Experiments on NO reduction under both N2 and CO2 atmosphere have been carried out. The results indicate that char-NO reaction is greatly influenced by coal rank and temperature under both N2 and CO2 atmosphere. The lower the coal rank is and the higher the temperature is, the stronger the effect of char on NO reduction will be. The high concentration of char in CFB plays an important role in NOx emission reduction. In CO2 condition, the high CO2 concentration can inhibit the reduction of NO by char and CO, therefore, the high CO concentration in oxy-fuel combustion may not be the main cause of its low NOx emission.