液-液相平衡数据的测定与关联——甲苯-正庚烷-DML三元体系

Liquid-Liquid Equilibrium Determination and Correlation ——Toluene-n-Heptane-DML Ternary System

在自制液液相平衡釜中加入不同比例的甲苯、正庚烷、Ｎ，Ｎ二甲基乙酰胺，在超级恒温水浴中震荡达到平衡，利用气相色谱法测定了常压下２０，３０℃时甲苯－正庚烷－Ｎ，Ｎ－二甲基乙酰胺三元液－液相平衡数据，采用峰面积归一化法定量，所得数据准确、可靠。绘制了三元液－液平衡相图，随着体系温度升高，两相区减小，均相区增大。用ＮＲＴＬ模型对所测数据进行关联，求出了相应的模型参数，关联的结果误差较小，证明ＮＲＴＬ模型适用于本体系液－液平衡的计算。

Toluene, heptane and N,N-dimethy lacetamide are put into a special liquid-liquid equilibrium still with different proportions. The ternary system is oscillated into equilibrium in a super constant temperature water bath. Liquid-Liquid equilibrium (LLE) data of the ternary system at 20℃ and 30℃are determined at the atmospheric pressure by gas chromatography. The quantitative analysis is based on the normalization of peak area%, and the accurate results are acquired. The ternary phase map of LLE is drawed at the two temperatures. The binary phase area decreases and the homogeneous phase area increases. The NRTL model is used to correlate the LLE data of the system. The correlating is carried out in the simplex optimization. The model parameters of the activity coefficient are obtained. The numerical answers are obtained in the direct iteration. The results are satisfactory. The NRTL model is suitable for the calculation of the LLE system.