乙二醇-1,2-丁二醇二元体系汽液平衡数据的测定及关联

为解决合成气经由草酸酯制乙二醇反应过程中产生的副产物1,2-丁二醇与乙二醇的分离问题,利用改进的Ellis汽液平衡釜测定了乙二醇-1,2丁二醇二元体系常压下汽液平衡数据,并通过Herington规则验证了实验结果符合热力学一致性。分别用Wilson和NRTL模型对实验数据进行热力学关联,得到了相关的模型参数并计算了该二元体系不同摩尔分数2种组分的活度系数值,预测了该二元体系的共沸点组成(摩尔分数)为乙二醇47.0%,1,2-丁二醇53.0%,共沸点温度为465.91 K。汽相组成的计算值与实验值平均相对偏差均小于0.2%,说明2种模型均适用于该二元体系,为工业分离工艺的设计提供了参考。

Determination and correlation of VLE data for ethylene glycol and 1,2-butanediol system

Instead of the conventional route from petroleum,the development of the process to produce ethylene glycol(EG) from the syn-gas has risen to a new level.Vapor-liquid equilibrium data of ethylene glycol and 1,2-butanediol were measured by using an improved Ellis vapor-liquid equilibrium pot at atmosphere pressure.The thermodynamic consistency for experimental data of EG-1,2-BDO system was confirmed by means of Herington method.Wilson and NRTL models were used for the correlation of vapor-liquid equilibrium data by Aspen Plus.With the model parameters obtained,the activity coefficients and the azeotropic point which was 465.91 K with 47.0% of EG and 53.0% of 1,2-BDO were also calculated.After the calculation of the mole fraction of gas phase,the mean relative deviation of calculated data and that of experimental data for both Wilson and NRTL were less than 0.2%.The result shows that both Wilson and NRTL models are applicable for EG-1,2-BDO system.This research is helpful for further industry process design.