用修正的UNIFAC模型参数及HVOS规则预测汽液平衡

Prediction of Vapor-Liquid Equilibrium Using Modified UNIFAC Model Parameters Combined with the Mixing Rule of HVOS

利用Orbey和Sandler提出的HVOS混合规则,PR状态方程与Larsen的活度系数模型相结合建立了无限压力下汽液平衡模型,模型给定状态方程中不随温度变化的参数C*=-0.623 23。用大量的汽液平衡数据在广泛的温度范围内修正了12组MLUNIFAC基团相互作用参数,并用修正的和原始的参数分别对含醇、酸、酮、水、腈和胺等极性二元体系进行了预测。结果表明,体系预测精度显著提高,大部分体系汽相组成的绝对偏差低于4.00×10-2,压力的相对偏差低于6.00%。

The model for predicting vapor-liquid equilibria of mixtures at an infinite pressure reference state was presented by PR equation of state combined with Larsen UNIFAC activity coefficient model using the Orbey and Sandler＇s mixing rule of HVOS. In this model the parameter C^＊ in equation of state was given without the change of temperature, C^＊ = - 0.623 23. A revision of total 12 pairs of group interaction parameters of Larsen UNIFAC model was clone by using the latest vapor-liquid equilibrium data in large range of temperature and wide range of systems. And predictions of vapor-liquid equilibria including alcohol, acid, ketone, water, nitrile and amine systems were made by using the new parameters and original parameters respectively. The results show that a significant improvement of prediction was achieved for many systems. The mean absolute deviations of calculation of vapor-composition were less than 4.00 × 10^-2 , and the mean relative deviations of bubble-pressure was less than 6.00 %.