基于反应动力学模型的SCR催化剂氨存储特性研究

摘要

A kinetic model for the adsorption-desorption of ammonia on SCR catalyst with single or dual active sites weas established.To this end, the model parameters were identified by ammonia adsorption-desorption tests on powdered SCR catalyst.The experimental results show that the adsorption-desorption process of ammonia on SCR catalyst can be described by the dual active sites reaction kinetic model than the single active site reaction kinetic model.The influences of temperature and ammonia inlet concentration on the ammonia storage capacity of SCR catalyst were studied based on the dual active sites reaction kinetic model.The simulation results show that the higher the temperature, the less the ammonia storage capacity of SCR catalyst, and the higher the ammonia inlet concentration, the higher the ammonia storage capacity with weak adsorption site, while the ammonia storage capacity with strong adsorption site remains the same.%建立NH3在选择性催化还原(selective catalytic reduction, SCR)催化剂上的单活性位和双活性位吸附脱附反应动力学模型.通过粉末状SCR催化剂的NH3吸附脱附试验对模型参数进行辨识.试验结果表明:双活性位反应动力学模型能更好地描述NH3在SCR催化剂上的吸附脱附过程.在双活性位反应动力学模型的基础上,研究了温度和入口NH3浓度对SCR催化剂氨存储量的影响.仿真结果表明:温度越高,SCR催化剂氨存储量越少;入口NH3浓度越高,弱吸附位的氨存储量越高而强吸附位的氨存储量基本保持不变.