2kPa下γ-丁内酯-二乙二醇二元系汽液平衡研究

Study on Vapor-Liquid Equilibrium of a γ-Butyrolactone-Diethylene Glycol Binary System at 2 kPa

采用自制的Rose釜在绝压2 kPa下测定γ-丁内酯-二乙二醇二元系的汽液平衡数据,并对所测得的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。以汽相组成的误差平方和作为目标函数,分别用Wilson和NRTL方程关联实验数据,得到分子交互作用能量参数,并对汽液平衡计算值与实验值进行比较,发现二者最大偏差为0.0143,平均偏差0.0063。采用溶液浓度三次方程分别对Wilson和NRTL方程进行修正,修正后二者最大偏差0.0094,平均偏差0.0036,明显优于修正前的结果,可满足工程上分离设计的需要。

The vapor-liquid equilibrium （VLE） data of the γ-butyrolactone-diethylene glycol system were measured at 2kPa using a home-made Rose vapor-liquid equilibrium device, and the thermodynamic consistency of the experimental data were examined. The results show that the experimental data are thermodynamically consistent. The VLE data obtained were correlated with Wilson and NRTL equation respectively, and model parameters were determined. Comparison of the experimental data with fitting equation results shows that the maximum deviation and the average absolute deviation are 0.0143 and 0.0063, respectively. A cubic polynomial modification of the Wilson and NRTL equation considering the molar composition of the liquid phase was proposed. The results show that the maximum deviation and the average absolute deviation of the modified equations are 0.0094 and 0.0036, which indicates that the modified models are better for engineering separation design.