Abstract:

Vapor-liquid equilibrium (VLE) data for ternary system of α-pinene(1) + β-pinene(2)+ p-cymene(3) were measured at 53.3 kPa and 80.0 kPa using the modified Dvorak-Boublik equilibrium still. The experimental data of ternary systems were found to be thermodynamically consistent by the McDermott-Ellis method. The ternary system data at reduced pressure were predicted with the parameters of NRTL model obtained from the pertinent binary systems. The maximum absolute deviations in temperature at two pressures were 0.80 and 0.86 K respectively, average absolute deviations were 0.30 and 0.39 K respectively. The ternary absolute deviation and average absolute deviation in vapor-phase mole fraction of α-pinene were 0.0096 and 0.0033 respectively, and those of β-pinene were 0.0102 and 0.0028 respectively at 53.3 kPa. The max absolute deviation and average absolute deviations in vaporphase mole fraction of α-pinene were 0.0083 and 0.0049 respectively, and those of β-pinene were 0.0081 and 0.0025 respectively at 80.0 kPa. These results provide the basis data for the separation of main components of turpentine.

Key words: vapor-liquid equilibrium, activity coefficient, model, NRTL, prediction

摘要：

用Dvorak-Boublik双循环汽液平衡釜测定了三元体系α-蒎烯（1）+β-蒎烯（2）+对伞花烃（3）在53.3和80.0 kPa下的汽液平衡数据，采用McDermott-Ellis对三元体系的实验数据进行热力学一致性检验，所有数据均通过一致性检验。采用相关二元体系的NRTL模型参数预测α-蒎烯+β-蒎烯+对伞花烃三元体系在53.3和80.0 kPa下的汽液平衡数据。结果表明：三元体系在两个压力下平衡温度的最大绝对偏差分别是0.80和0.86 K，平均绝对偏差分别为0.30和0.39 K。该体系在53.3 kPa下α-蒎烯和β-蒎烯在汽相中的最大绝对偏差分别为0.0096和0.0102，平均绝对偏差分别为0.0033和0.0028；在80.0 kPa下α-蒎烯和β-蒎烯在汽相中的最大绝对偏差分别为0.0083和0.0081，平均绝对偏差为0.0049和0.0025。实验结果为松节油体系主要成分的分离提纯提供了基础数据。

关键词: 汽液平衡, 活度系数, 模型, NRTL, 预测