【摘要】 利用固定床反应器研究了煤焦吸附和还原NO的动力学,分析了热解温度(500℃~900℃)和矿物质对煤焦脱除NO的影响。结果表明,在程序升温反应(TPR)和等温反应中,随着温度的升高(30℃~600℃),煤焦-NO经历了从化学吸附到还原反应的转变。低温时煤焦脱除NO的动力学符合E lov ich方程,原煤焦的起始吸附速率随着温度的升高而增大,脱灰煤焦的起始吸附速率先增大后减小,等温吸附过程中煤焦的活化能随着吸附量的增大而增大。随着热解温度的升高,TPR中煤焦的NO转化率降低,等温还原反应的速率常数减小,高温热解导致煤焦脱除NO的活性降低。矿物质对煤焦-NO的吸附和还原反应存在催化作用。更多还原

【Abstract】 The kinetics of chemisorption and reduction reaction of NO on coal chars was investigated using a fixed bed reactor.The effect of pyrolysis temperature(500℃~900℃) and mineral matter on the removal of NO by coal chars was also analyzed.The results indicated that coal char and NO both in temperature programmed reaction(TPR) and isothermal reaction experienced a transition from chemisorption to reduction reaction with increasing temperature(30℃~600℃).The kinetics of coal chars and NO at low temperature could be well described by Elovich equation.The initial chemisorption rate of raw coal chars increased with elevated temperature,but the value of demineralized ones first increased and then declined.The activation energy of chemisorption during isothermal process increased with the increase of NO uptakes.The NO conversions during TPR and rate constants in isothermal reduction reaction varied inversely with pyrolysis temperature.Therefore,deactivation of coal char towards NO was caused by pyrolysis at high temperature.Additionally,the mineral matter played a catalytic role both in chemisorption and reduction reaction of NO on coal chars.更多还原