稀薄氨气的燃烧特性及动力学研究

文章通过稀薄氨气在固定床反应器中的燃烧,研究了反应温度、停留时间、氨气浓度和氧气浓度对低浓度氨气燃烧特性的影响,并描述了氨气在氧气过量条件下在陶瓷蜂窝蓄热体中燃烧的动力学过程。研究结果表明:提高反应温度、延长停留时间以及增大氧气浓度和氨气浓度均可以提高NH3转化率,氧气浓度过高会促进NO生成;当反应温度为740~770℃、氨气浓度为1%、氧气浓度为15%时,氨气在陶瓷蓄热体中燃烧的活化能为253.56 kJ/mol;与氨气在自由空间内的燃烧相比,氨气在陶瓷蜂窝蓄热体中主要发生表面燃烧反应。

Study on combustion characteristics and kinetics of lean ammonia

Many enterprises emit low-concentration ammonia gas in the exhaust gas,and the ammonia gas can be used as a fuel.Therefore,the effects of temperature,residence time,ammonia concentration and oxygen concentration on the combustion characteristics were studied by burning lean ammonia gas in a fixed bed reactor under sufficient oxygen conditions.The kinetic process of ammonia combustion in ceramic honeycomb regenerator with excess oxygen was described.The results show that increasing the temperature,prolonging the residence time and increasing the O2 and NH3 concentrations can increase the NH3 conversion rate.The excessive O2 concentration will promote NO production.The kinetic parameters of NH3 combustion in ceramic regenerators were calculated when the oxygen was excessive and the temperature range was from 740 to 770℃,the activation energy was 253.56 kJ/mol.By comparing the combustion of ammonia in free space,it can be proved that the NH3 combustion in porous media was mainly in the surface reaction way.