【作者】 马利娜；

【导师】 计伟荣； 王建黎；

【作者基本信息】 浙江工业大学 ， 化学工程， 2008， 硕士

【摘要】 离子液体作为一种新型的“绿色溶剂”,正越来越多的应用于萃取分离中。而选择性是萃取分离中的关键性因素,通过溶质在离子液体中的无限稀释活度系数可以得到离子液体的选择性,从而为共沸精馏,萃取精馏和萃取分离中选择适合的离子液体作为萃取剂提供选择依据。本文开展了以下几个方面的研究工作:1.本文采用反相气相色谱法（IGC）测定323.15～353.15K下27种溶质在六种离子液体中的无限稀释活度系数。并对这六种离子液体在有机、含水共沸体系以及一些性质相似的体系中的选择性进行了研究。离子液体[EMIM][N（CN）₂]、[RMIM][OAc]对于有机、含水共沸体系具有很好的选择性。2.离子液体的无限稀释热力学性质计算。用无限稀释活度系数与温度的关系回归出溶质在离子液体中的无限稀释偏摩尔焓;用探针分子比保留体积与温度的关系回归出溶质在离子液体的无限稀释溶解焓。并计算出偏摩尔混合自由能和偏摩尔混合熵。3.用UNIFAC模型对溶质在六种离子液体中的无限稀释活度系数进行关联,总相对平均偏差为9.31%。并对六种离子液体在二元共沸、同分异构体等工业中较难分离体系中的选择性进行预测。结果令人满意。更多还原

【Abstract】 Ionic liquids （ILs）, serving as "green solvents" , are more and more used in extractive separation processes. The selectivity of ILs, which can be described by the ratio of the infinite dilution activity coefficients of different solutes in ILs, are of great significance for selecting appropriate ILs in azeotropic rectify, extractive rectify and other separation processes. In this work, the activity coefficients at infinite dilution and the selecticity of ILs have been studied as follows:1. Activity coefficients at infinite dilution were measured for 27 solutes in six ILs at 323.15～353.15 K by inverse gas chromatography （IGC）. The infinite dilution selectivities of these ILs in separation of organic, aquiferous azeotropic and binary systems with similar property were determined. The results show that [EMIM][N（CN）₂], [RMIM][OAc] are good extractants or entainers for binary aqueous azeotropes and the systems with large asymmetric polarity except isomers.2. The theromadynamic properties at infinite dilution were derived. The partial excess molar enthalpies at infinite dilution of solutes in the ILs were derived from the temperature dependence of the values of infinite dilution activity coefficient; the infinite dilution enthalpies of solutes in the ILs were regressed from the temperature dependence of the values of probe specific retention volume. Additional partial mole free energy of mixing and partial mole entropy of mixing of solutes in the ionic liquid were calculated.3. UNIFAC group contribution method has been used to calculate the infinite dilution activity coefficients of solutes in ILs. The interaction parameters of the fragements were regressed by using the experimental data obtained in this work. The total relative average deviation is 9.31% . The selectivities of binary systems including azeotropes, isomers were predicted and satisfactory results were derived.更多还原