油酸甲酯催化加氢制备生物烷烃的热力学分析

采用Benson基团贡献法对油酸甲酯加氢脱氧、加氢脱羰和加氢脱羧制备生物烷烃的热力学进行了分析，计算了613~653 K温度区间内油酸甲酯加氢体系的反应热、反应熵变、反应Gibbs自由能变和标准平衡常数，在此基础上采用PRO/Ⅱ软件中的平衡反应器模型分析了温度对油酸甲酯加氢产物分布的影响并和实验数据进行了对比验证。结果表明，油酸甲酯加氢脱氧、加氢脱羧和加氢脱羰制备生物烷烃的反应均为放热反应，放热量依次递减，各反应在613~653 K范围内均能够自发进行且反应完全。升高温度能够提高平衡产物中油酸甲酯加氢脱羰/羧产物的选择性，降低温度则有利于加氢脱氧产物的选择性，加氢脱氧与脱羰/羧产物选择性的比例随温度从613 K升高到653 K相应从1.92降低到0.56，与实验测得的反应数据变化趋势吻合。

Thermodynamic analysis of catalytic hydrogenation of methyl oleate to produce bio-paraffins

The thermodynamic analysis of the hydrogenation of methyl oleate to bio-paraffins via hydrodeoxygenation (HDO), hydrodecarbonylation (HDCO) or hydrodecarboxylation (HDCO₂) routes was carried out by the Benson group-contribution method. Changes of enthalpy, entropy and Gibbs free energy, as well as the standard equilibrium constants, for each reaction were calculated in the temperature range of 613—653 K. The equilibrium distribution of products as a function of temperature was also simulated based on an equilibrium reactor of PRO/Ⅱ software and compared with the experimental data. The calculated thermodynamics indicates that HDO, HDCO and HDCO₂ of methyl oleate are exothermic processes, with the released heat decreasing in the order of HDO>HDCO₂>HDCO, and each reaction can take place spontaneously and proceed completely. Moreover, improving temperature prefers HDC to HDO products at equilibrium, results in a decreasing HDO/HDC ratio from 1.92 to 0.56 as the temperature rises from 613 K to 653 K, consisting well with the experimental data collected in the catalytic hydrogenation of methyl oleate.