Abstract:

The influence of six different solvents on the relative volatility of n-butanol and chlorobenzene system was investigated, which shows that acetophenone has a better performance in this minimum azeotrope system. Isobaric vapor-liquid equilibrium (VLE) data for binary systems of n-butanol-chlorobenzene, n-butanol-acetophenone, chlorobenzene-acetophenone and ternary system of n-butanol-chlorobenzene-acetophenone at 101.33 kPa were measured by using a vapor-liquid equilibrium still. And then, all of the measured VLE values were checked by the area method proposed by Herington and the point-to-point method of Van Ness. Furthermore, the VLE data were correlated by Wilson, NRTL and UNIQUAC activity coefficient, respectively. The binary interaction parameters were used to predict the ternary VLE behavior, which fit with the experimental data. The experimental results indicate that the relative volatility between n-butanol chlorobenzene is changed obviously by adding acetophenone as a solvent at 0.50 mass fraction, which shows that acetophenone is a promising solvent for the separation of the n-butanol and chlorobenzene mixture in extractive distillation. This work provides important engineering data for chemical database and further study in the engineering design.

Key words: vapor-liquid equilibria, n-butanol, chlorobenzene, acetophenone, thermodynamic model

摘要：

正丁醇-氯苯常压下存在最低共沸现象，首先应用汽液平衡法从6种备选溶剂中筛选出苯乙酮作为最佳萃取剂，然后分别测定了正丁醇-氯苯、正丁醇-苯乙酮、氯苯-苯乙酮3个二元体系以及正丁醇-氯苯-苯乙酮三元体系在101.33 kPa下的汽液平衡数据。所有实验数据都通过了Herington法和Van Ness法的热力学一致性检验，采用Wilson、NRTL和UNIQUAC 3种活度系数模型进行关联计算，其二元拟合数据与实验数据吻合较好。使用关联得到的二元交互参数推算三元汽液平衡数据，并与实验值进行对比，偏差在合理范围以内。结果表明，苯乙酮作为萃取剂可以有效地改变正丁醇与氯苯的相对挥发度，在溶剂质量比为1：1时能够使共沸现象消失。为工业上使用萃取精馏分离正丁醇-氯苯体系提供参考，也为汽液平衡数据库补充新的内容。

关键词: 汽液平衡, 正丁醇, 氯苯, 苯乙酮, 热力学模型