Ni-Mg复合催化剂催化裂解CH_4制氢动力学研究

基于定温热重实验,建立了甲烷催化裂解反应动力学模型和催化剂表面积炭失活动力学模型。其中,甲烷催化裂解动力学模型将初始产氢速率视为催化剂未积炭条件下的动力学基础数据;催化剂表面积炭失活动力学则基于甲烷催化裂解速率的降低。实验使用Ni-Mg复合催化剂,分别在535、585、635℃,甲烷分压10~4、2×10~4、3×10~4Pa条件下展开甲烷催化裂解动力学特性研究。结果表明,甲烷催化裂解的反应级数为0.5,活化能为82 k J/mol;Ni-Mg复合催化剂反应失活级数为0.5,催化剂失活活化能为118 k J/mol。实验条件下均制得了多壁碳纳米管。

Kinetic study of the decomposition of methane over Ni-Mg composite catalyst for hydrogen production

The kinetic and deactivation kinetic models of methane catalytic cracking were established based on the data of thermal gravimetric analyzer.The kinetic model of methane catalytic cracking was established by the data of initial hydrogen production rate under the condition of no carbon deposition.The deactivation kinetic model was established by the reduced rate of methane catalytic cracking.The experiment was carried out over Ni-Mg composite catalyst, at the temperature of 535, 585, 635℃ and the methane partial pressures were 10⁴, 2×10⁴, 3×10⁴ Pa.The result shows that the reaction order and activation energy were 0.5 and 82 kJ/mol, the deactivation order and activation energy were 0.5 and 118 kJ/mol respectively.The multi-walled carbon nanotubes were all produced under the experimental conditions.