高体积分数CO_2气氛下NO-煤焦反应特性

Study on NO-Char Reaction Characteristics in High-CO_2 Concentration Atmosphere

以李家塔烟煤和锦界烟煤煤焦为研究对象,利用固定床反应器系统,研究了高体积分数CO2气氛下煤焦异相还原NO的反应特性,分析了反应气氛、CO2体积分数、O2体积分数、NO初始体积分数和热解温度等对煤焦还原NO的影响.结果表明:反应气氛中高体积分数CO2的存在不利于煤焦还原NO,且CO2体积分数越大,越不利于NO还原;当反应温度较低时,反应气氛中O2对煤焦还原NO具有一定的促进作用,但当反应温度较高时则不利于NO还原;随着NO初始体积分数增大,NO还原率降低;随着热解温度的升高,煤焦还原NO的能力下降.

Taking Lijiata and Jinjie bituminous char as the object of study, the characteristics of NO-char reaction in high-CO2 concentration atmosphere were investigated in a fixed-bed reactor, so as to analyze the effects of following factors on the NO reduction by char, such as the reaction atmosphere, CO2 concentra- tion, O2 concentration, initial NO concentration and the pyrolysis temperature, etc. Results show that high concentration of CO2 existing in reaction atomphere is detrimental to the NO reduction by char, and with the rise of CO2 concentration, the effect becomes more obvious. At low reaction temperatures, the presence of O2 in reaction atmosphere has a certain promotion effect on the reduction of NO, whereas at high temperatures, it＇s the opposite. The reduction rate of NO reduces with the increase of initial NO con- centration. The reactivity of char decreases with increasing pyrolysis temperature.