O2/CO2条件下煤焦-NO生成特性的实验研究

摘要

In order to reveal NO formation characteristics and the effect of CO2 concentrated and CO on NO heterogeneous reduction with char during the process of O2/CO2 combustion,the combustion experiments for Shanxi lignite were carried out on a horizontal furnace.The results show that,compared with O2/N2 atmosphere,NO emissions from coal-nitrogen can be effectively suppressed in O2/CO2 combustion conditions.O2/CO2 atmosphere can inhibit converting volatile-nitrogen to NO remarkably,while the conversion of char-nitrogen to NO is relatively less restrained.The conversion of char-nitrogen to NO is significantly promoted with O2 concentration increasing.Char-NO heterogeneous reduction reaction is obviously improved by a moderate amount of CO2 and the promoting effect can be cancelled out to a certain extent by excess of CO2.The effect of CO addition on NO reduction is remarkable.The highest NO reduction efficient is reached when CO concentration is 0.5%,however,continuing rising of CO concentration can weaken the effect of NO reduction.%以山西褐煤为样品在固定床反应器上研究O2/CO2燃烧方式下NO的生成特性,分析了CO2,CO体积分数变化对于煤焦NO异相还原的影响。研究结果表明：与O2/N2气氛相比,O2/CO2燃烧条件下,煤粉NO的排放能够被有效抑制;O2/CO2气氛下挥发分N向NO的转化明显被抑制,而焦炭N向NO转化的抑制作用较弱;O2体积分数的升高对焦炭N向NO转化有明显的促进作用;适量CO2的存在对于煤焦-NO异相还原反应有明显促进作用,CO2体积分数过高则会抑制CO-NO还原反应的进行;CO的加入对NO还原效果明显,在CO体积分数为0.5%时NO还原效率最高,CO体积分数继续升高,还原效果有所减弱。