1-甲基萘加氢饱和反应热力学平衡分析及实验研究

双环芳烃定向转化为单环芳烃能有效提升催化裂化轻循环油(LCO)品质并缓解柴油产能过剩的问题。以1-甲基萘(1-MN)为模型化合物，通过热力学理论计算和实验对其加氢饱和反应热力学平衡特性及反应路径进行研究。热力学理论计算表明：四氢萘的加氢饱和反应自由能比1-甲基萘的加氢饱和反应自由能对于反应温度更为敏感；反应体系中1-甲基四氢萘(1-MTL)和5-甲基四氢萘(5-MTL)摩尔分数随反应温度、反应总压或氢/烃摩尔比的单独变化均存在最高值，当反应温度为650 K、反应压力为4.0 MPa及氢/烃摩尔比为5时，平衡体系中四氢萘类(MTLs)摩尔分数高达到47.2%。采用Ni-Mo/γ-Al₂O₃催化剂的加氢饱和反应实验结果与热力学理论计算的结果相一致，提高反应温度(高于623 K)能够抑制MTLs加氢饱和生成1-甲基十氢萘(1-MD)；提高H₂分压(高于4.0 MPa)虽能提高1-MN的转化率却使MTLs选择性降低，因此1-MN加氢饱和生成MTLs适宜的H₂分压为4.0 MPa。

Thermodynamic Equilibrium Analysis and Experimental Research on Hydrogenation Saturation Reaction of 1-Methylnaphthalene

The oriented conversion of bicyclic aromatic hydrocarbons to the monocyclic aromatic hydrocarbons can effectively improve the quality of FCC light cycle oil (LCO) and alleviate the problem of diesel overcapacity. In this study, 1-methylnaphthalene was set as the model compound and its thermodynamic equilibrium characteristics and reaction paths of hydrogenation saturation reaction were explored by thermodynamic theoretical calculations and experiments. The results of thermodynamic theoretical calculations show that the hydrogenation saturation reaction free energy of tetralin is more sensitive to temperature than that of 1-methylnaphthalene; there is a maximum when the molar fractions of 1-MTL and 5-MTL in the reaction system separately change with reaction temperature, total reaction pressure or hydrogen/hydrocarbon molar ratio, so that the molar fraction of MTLs in the equilibrium system is as high as 47.2% under the reaction temperature of 650 K, reaction pressure of 4.0 MPa and hydrogen/hydrocarbon molar ratio of 5. The experimental results of the hydrocarbon saturation reaction with Ni-Mo/γ-Al₂O₃ as catalyst are consistent with the results of thermodynamic theoretical calculations, indicating that increasing the reaction temperature (higher than 623 K) can inhibit the formation of 1-methyldecalin (1-MD) from MTLs by hydrogenation saturation; increasing the hydrogen partial pressure (higher than 4.0 MPa) can improve the conversion rate of 1-MN, but reduce the selectivity of MTLs, so that the suitable hydrogen partial pressure for the hydrogenation saturation of 1-MN to generate MTLs is 4.0 MPa.