煤焦燃烧生成NO的特性研究

Characteristics of NO release during coal char combustion

对小屯煤焦中氮的存在形态进行了X射线光电子能谱(XPS)分析。并对小屯煤焦在模拟分解炉中NO释放特性进行了实验研究,考察了气氛、温度、生料对焦炭氮释放特性的影响。研究结果表明:小屯煤焦中氮主要以吡咯五元环形式存在;氧气体积分数对NO的生成速率有明显影响;在无生料催化下,生成量基本随温度的升高而加大,但是,当生料存在时,生成量随温度的升高而减少;生料的加入大大加速了NO的生成速率和生成量,表明生料对NO生成有显著的催化作用。焦炭氮转化为NO的几率主要由2个互相竞争的反应决定:包括N的氧化反应和NO的还原反应。

X-ray photoelectron spectroscopy （XPS） was used to investigate the nitrogen functional forms presented in Xiaotun coal char. It was demonstrated that nitrogen in pyrrolic forms is main. And the characteristics of NO release during coal char combustion were investigated in bench scale prealciner under various conditions. The results indicate that O2 volume fraction has a direct effect on rate of NO release, the amount of NO formation increases with temperature increasing in absence of cement raw meal, however, the law is opposite in presence of cement raw meal. The rate and amount of NO formation clearly rise in presence of cement raw meal, which suggests cement raw meal has distinct catalytic effect on NO formation. NO originates mainly from the oxidation of fuel nitrogen in the industrial precalciner. The conversion of char-N to NO is controlled by two competitive reactions： the oxidation of fuel nitrogen and deoxidization of NO.