Abstract:

1,6-Hexanediol is an important building-block chemical and applied widely in the synthesis of specialty chemicals and a variety of polymers, primarily in polyesters, polyurethanes and polyamides. Industrially, a most common route for 1,6-hexanediol production is catalytic hydrogenation of dimethyl adipate. Thermodynamic analysis and kinetic study are important links in the study of chemical process, but few reports have been reported on the dimethyl adipate hydrogenation. Hence, thermodynamic data of dimethyl adipate (DMA) and 1,6-hexanediol were calculated by group contribution method in this work, and the enthalpy, entropy, Gibbs free energy and equilibrium constant of reaction under different reaction conditions were calculated. As can be seen from the calculated results that the decreases of temperature and increases of pressure are beneficial to increasing the reaction equilibrium constant. Besides, kinetic study of DMA hydrogenation was preformed in the fixed bed tubular reactor. Experiments were carried out under the following conditions: temperature 473.15—514.15 K, pressure 2.0—6.1 MPa, LHSV 1.28—2.55 h^-1, molar ratio of H₂ to DMA 150—270. The exponential model was employed to describe the reaction rate and the obtained activation energy for dimethyl adipate hydrogenation was 63.55 kJ·mol^-1. The reaction order of dimethyl adipate and hydrogen are 0.63 and 0.40 respectively. The statistical test results show that the model can better describe the DMA hydrogenation reaction.

Key words: thermodynamics, kinetics, hydrogenation, reaction engineering, group contribution method

摘要：

采用基团贡献法计算了己二酸二甲酯（DMA）和1,6-己二醇（HDOL）的热力学相关数据，在不同反应条件下，计算了DMA加氢生成HDOL反应的焓变、熵变、Gibbs自由能变和平衡常数，探讨了反应温度、压力对Gibbs自由能变和平衡常数的影响。利用固定床管式反应器，对DMA加氢反应本征动力学进行研究，采用幂函数型动力学方程对实验结果进行拟合，得到了反应的活化能为63.55 kJ·mol^-1，DMA和H₂的反应级数分别为0.63和0.40。统计学检验结果表明，该模型能较好地描述DMA加氢反应。

关键词: 热力学, 动力学, 加氢, 反应工程, 基团贡献法