3-羟基丙酸甲酯加氢合成1,3-丙二醇反应的热力学计算

Thermodynamic calculation of the synthesis of 1,3-propanediol by hydrogenation of methyl 3-hydroxypropionate

3-羟基丙酸甲酯催化加氢是合成1,3-丙二醇的一种重要反应,具有工业应用前景.本研究对该反应及其涉及的副反应进行了热力学计算.采用Benson、Joback和Constantinou-Gani 3种基团贡献法,计算了上述反应目前尚缺失的热力学数据.按照Gibbs-Helmholtz方程绘制了相关反应的热力学平衡常数的对数值(lg k)与温度的变化曲线,其中Benson法所得结果与实验结果较好吻合.依据Benson法计算的平衡常数,绘制了压力和温度、压力和氢酯比、底物浓度分别对3-羟基丙酸甲酯加氢合成1,3-丙二醇反应平衡转化率的关系曲面和曲线图,并讨论了上述参数变化对反应的影响.计算数据显示,高压、高氢酯比、低温和低液时空速有利于3-羟基丙酸甲酯向1,3-丙二醇的转化,该结果与实验数据吻合.

Catalytic hydrogenation of methyl 3-hydroxypropionate(3-HMP)is an important reaction in the synthesis of 1,3-propanediol(1,3-PDO),which has application potential in industry.In this study,thermodynamic calculations in detail were carried out of this reaction and other related side reactions.The Benson,Joback,and Constantinou-Gani groups methods were respectively applied to gain the data involved in the reactions that had not been available so far.The curve of lg k(k is thermodynamic equilibrium constant)versus temperature was plotted according to the Gibbs-Helmholtz equation,among which the results obtained using the Benson method were more consistent with the experimental results.The surface diagrams of the equilibrium conversion rate versus pressure and temperature,pressure and hydrogen-ester ratio,and curve diagrams of the concentration of substrate for hydrogenation of 3-HMP to 1,3-PDO were plotted,based on the equilibrium constant calculated using the Benson method.The effects of the above parameters on the reaction were also discussed.The calculated data showed that high pressure,high hydrogen-ester ratio,low temperature and low liquid space velocity were helpful to increase the conversion of 3-HMP to 1,3-PDO.These results were well consistent with the experimental data obtained by experiment.