乙醇-甲苯-水-氟化钾液液平衡数据的测定及关联

Liquid-liquid equilibrium determination and correlation for system of ethanol-toluene-water-potassium fluoride

实验采用液液平衡釜测定常压下、298.15 K时乙醇-甲苯-水-氟化钾(KF)四元体系的液液平衡数据,计算了水+KF混合萃取剂对乙醇的选择性系数和分配系数,二者都远大于1。采用Rajendran改进的Eisen-Joffe方程对液液平衡数据进行可靠性检验,计算方程的最大标准差为0.05,最低相关系数为0.993。并使用Aspen数据回归模块,采用NRTL模型对实验体系的液液平衡数据进行回归,得到相应热力学模型参数,将实验值与计算值进行对比,绘制了四元体系的拟三元液液平衡相图,结果表明,NRTL模型可以很好的关联实验数据,相对均方根差最大值为1.4626%。

Liquid-liquid equilibrium data were determined for the quaternary system of ethanol-toluene-water-potassium fluoride at atmospheric pressure and 298.15 K. The selectivity coefficient and partition coefficient of ethanol in water＋potassium fluoride extraction agent were calculated. The experimental results show that the selectivity coefficient and partition coefficient are far greater than 1. The experimental data were correlated by Rajendran＇s improved Eisen-Joffe model. The maximum standard deviation was 0.05, the least correlation coefficient was 0.993. The NRTL equation was used to correlate the experimental data, the thermodynamic model parameters of this systems were obtained, and the calculation and experimental were compared. The results showed that the NRTL model was able to correlate the experimental data well, with the maximum values of root mean square deviation （RMSD） of 1.4626% for NRTL.