真空下1,2-丁二醇-乙二醇二元体系气液平衡数据的测定及关联

Measurement and correlation of isobaric vapor-liquid equilibrium for binary system 1, 2-butanediol+ethylene glycol under vacuum

为了解决煤制乙二醇中1,2-丁二醇与乙二醇的分离问题,采用气相单循环法测定了绝压6.67kPa下1,2-丁二醇-乙二醇二元体系的气液平衡数据,结果发现此物系存在共沸物,共沸温度为395.67K,共沸组成为含1,2-丁二醇0.457(摩尔分率)。并用Herrington面积检验法对实验数据进行热力学一致性检验,结果表明实验数据符合热力学一致性。分别用Wilson、NRTL和UNIQUAC模型对气液平衡数据进行关联,得到了各个模型的二元交互作用参数,并对气液平衡数据的模型计算值与实验值进行比较,发现二者偏差较小,可满足工程上分离设计的需要。

In order to separate 1,2-butanediol and ethylene glycol, the method of only vapor phase circulation was used to measure the vapor-liquid equilibrium （VLE） values of the binary system 1,2-butanediol＋ethylene glycol at 6.67kPa. Azeotropic behavior was found for this system： the azeotropic temperature is 395.67K and the azeotropic composition is 0.457 mole fraction 1,2- butanediol. The measured VLE data of the binary system could pass the thermodynamic consistency test according to Herington area method, and were correlated by Wilson, NRTL and UNIQUAC activity coefficient models. And all the models showed rather small deviation from the experimental results, indicating that the experimental data could be suitable for use in the industrial process design.