二苯醚水解耦合苯酚氧化羰基化合成碳酸二苯酯的热力学分析

以碳酸二甲酯和碳酸二乙酯的热力学数据为基础,结合Benson、Joback和马沛生基团贡献法估算了碳酸二苯酯(DPC)的热力学性质,进而计算了苯酚氧化羰基化合成DPC反应和二苯醚水解反应的焓变、熵变、吉布斯自由能变和平衡常数。计算结果表明,两个反应均为放热反应;在5 MPa、353～413 K下,两个反应均为自发过程,其中苯酚氧化羰基化反应的平衡常数较大,且随温度的升高而降低;二苯醚水解反应的平衡常数较小,且随温度的升高而增大。为达到耦合除水的目的,两个反应的反应速率需维持合适的比例。

Thermodynamic Analysis of Coupling of Oxidative Carbonylation of Phenol with Hydrolysis of Diphenyl Ether

Based on the thermodynamic data of dimethyl carbonate and diethyl carbonatethe,thermodynamic properties of diphenyl carbonate were estimated by using Benson,Joback and Ma Peisheng group contribution methods,and then the enthalpy changes,entropy changes,Gibbs free energy changes and equilibrium constants in the oxidative carbonylation of phenol to diphenyl carbonate and the hydrolysis of diphenyl ether were calculated.The results show that the two reactions are exothermic and spontaneous under the conditions of 5 MPa and 353-413 K.The equilibrium constant of the oxidative carbonylation of phenol is larger than that of the hydrolysis of diphenyl ether.With the rise of temperature,the former decreases but the latter increases.It is necessary for the rates of the two reactions to maintain an appropriate proportion to remove water by the hydrolysis.