苯胺氧化羰化反应体系热力学计算与分析

Thermodynamic calculation and analysis of the oxidative carbonylation of aniline reactive system

苯胺氧化羰化合成二苯脲或氨基甲酸酯是直接由CO出发替代污染严重的光气法的绿色工艺.对苯胺氧化羰化所涉及的主要主副反应采用基团贡献法进行热力学计算,求得相关反应焓、反应熵和Gibbs自由能数据,根据计算结果,副反应苯胺甲基化反应的平衡常数比主反应低3～5个数量级,另一副产物1,3-二氮杂萘为次要副产物.升高温度,主产物选择性会降低,而增大反应压力有利于主反应进行,提高主产物的选择性.图3,表9,参9.

The synthesis of diphenyl urea or methyl N-phenyl carbamate by oxidative carbonylation of aniline is a green process replacing the polluting phosgene route, which starts from CO as raw material. The corresponding data of reaction enthalpy, entropy and Gibbs free energy of the main and side reaction involved in oxidative carbonylation of aniline were calculated based on the group contribution method. The results indicate that the equilibrium constant of the side reaction methylation of aniline is lower by 3-5 amount lever than the main reaction. Another by-product, quinazoline is the minor product in the product distribution. The selectivity of the main product is decreased when promoting the reaction temperature, while the increase in the pressure is advantageous to the proceeding of main reaction and the selectivity of main product. 3figs., 9tabs., 9refs.