铜基催化剂上甲烷催化燃烧反应动力学特性研究

采用固定床微分反应器,在常压、450~500℃、甲烷体积分数10%~35%条件下,进行铜基催化剂上甲烷催化燃烧动力学特性研究。研究表明,甲烷分压对反应速率影响显著,而氧气分压的影响可以忽略。采用最小二乘法进行动力学模型参数估计,建立的反应动力学模型为-rCH4=1.61×107×e-108 000/RT×pCH40.5。检验结果表明,所建模型与实验数据良好相容,是适宜和可信的。根据实验结果推断甲烷催化燃烧分两步进行,首先氧气快速与铜基催化剂上活性空位点反应,形成吸附氧气分子;随后吸附氧气分子和甲烷分子反应,生成二氧化碳和水。

Reaction kinetics of methane combustion on copper-based catalyst

An experimental investigation of methane combustion on copper-based catalyst was carried out in a micro-fixed bed reactor under atmospheric pressure at 450~500℃ with inlet methane volume fraction between 10% and 35%. The influence of methane partial pressure on reaction rate is found to be significant, while that of oxygen is neglectable. Parameters of the kinetic model were estimated using the least squares method. The resulted kinetic model of methane catalytic combustion is -r_CH4=1.61×10⁷×e^{-108 000/RT}×p_CH4^0.5. Predicted and experimental values of methane conversion agree well with each other, which shows the reliability and accuracy of the model. The above reaction can be described as a two-step reaction according to the experimental result. Oxygen reacts quickly with the active vacancy sites of the catalyst to form adsorbed oxygen molecules which reacts with methane molecule to form carbon dioxide and water.