CO_2和丙三醇合成丙三醇碳酸酯的热力学分析

Thermodynamic analysis on synthesis of glycerol carbonate from CO_2 and glycerol

采用Benson基团贡献法计算了298.15K丙三醇碳酸酯的液态标准摩尔生成焓和标准熵,利用Joback基团贡献法及Sternling-Brown方程计算了丙三醇碳酸酯的液态摩尔等压热容随温度变化的函数关系式。结合文献中的其它热力学数据,计算了由CO2和丙三醇合成丙三醇碳酸酯反应体系中涉及到的反应焓变、吉布斯自由能变和标准平衡常数以及反应压力。结果表明,该反应在热力学上是不可行的,耦合反应是实现该合成过程的有效方法。

The standard enthalpy and standard entropy of liquid glycerol carbonate at 298.15K were calculated by the method of Benson group contribution,and the functional correlation between the heat capacity of the liquid glycerol carbonate and temperature was calculated by the method of Joback group contribution and Sternling-Brown equation.Based on the above thermodynamic data and those from literature,the thermodynamic data for glycerol carbonate synthesis from CO2 and glycerol,including reaction enthalpy,Gibbs free energy,standard equilibrium constant and reaction pressure were calculated.The results showed that the synthesis reaction was not feasible thermodynamically,and the coupling reaction was an effective method to promote the synthesis reaction.