环烷酸乙二醇酯的HDO热力学分析

以选取的环烷酸乙二醇酯模型化合物为基础,利用热力学方法分析其加氢脱氧反应发生的可能性。由于环烷酸乙二醇酯及双环环烷烃的结构复杂,无法直接获得其热力学数据,故采用基团贡献法估算了环烷酸乙二醇酯及双环环烷烃在298.15 K标准状态下的生成焓、标准熵及热容随温度的变化关系,进而得到不同温度条件下环烷酸乙二醇酯HDO的焓变、吉布斯自由能变及平衡常数。计算结果表明,环烷酸乙二醇酯的HDO反应在指定条件下为放热反应并可自发进行,且其平衡常数很大,可视为不可逆反应。该方法也可用于其它酯类物质HDO的热力学分析。

Thermodynamics Analysis on HDO Reaction of Naphthenic Acid Glycol Ester

Taking naphthenic acid glycol ester as model compound, the possibility of the hydrogenation reaction of the model compound was analyzed by thermodynamics method. Due to the complexity of the structures of naphthenic acid glycol ester and bicycloalkane, their thermodynamic data could not be obtained from literatures directly. Therefore, the method of group contribution was applied to estimate the enthalpy and entropy of naphthenic acid glycol ester and bicycloalkane under the standard state. Meanwhile, the functional correlation between the heat capacity of these organic compounds and temperature was established. Furthermore, the enthalpy change, the Gibbs free energy change and equilibrium constant of the HDO reaction were calculated under the different reaction conditions. The results illustrate that the HDO reaction of the naphthenic acid glycol ester may occur and its equilibrium constant is very large, therefore it can be considered as an irreversible reaction. The method set up in this paper can also be used in the thermodynamic analysis of HDO reaction of other esters.