计算离子液体溶液汽液相平衡的分子热力学模型  

A molecular thermodynamic model for calculating vapor liquid equilibrium of ionic liquid containing systems

作　　者：宋红艳[1,2] 王均凤[3] 沈冲[1,2] 赵瑾[4] 何静[1,2] 李春喜[1,2] 

机构地区：[1]化工资源有效利用国家重点实验室 [2]北京化工大学,北京100029 [3]中国科学院过程工程研究所,北京100190 [4]北京化工研究院,北京100013

出　　处：《中国科学：化学》2010年第9期1297-1303,共7页SCIENTIA SINICA Chimica

基　　金：国家自然科学基金(20376004);教育部博士点基金(20090010110001)的资助

摘　　要：用平均球近似理论、微扰理论和UNIFAC基团贡献方法分别考虑离子之间的长程静电作用、离子与溶剂之间的中程静电作用以及所有粒子之间的短程作用,本文提出了一种新的分子热力学模型,可用于离子液体溶液中溶剂活度系数的计算.通过对含烷基咪唑磷酸酯类离子液体与水、甲醇或乙醇组成的9个二元体系的饱和蒸汽压数据进行关联,获得了相关的模型参数,即溶剂的分子直径和基团之间的交互作用能参数.溶剂活度系数及饱和蒸汽压的计算结果与实验值的平均偏差为1.40%,符合良好,因此本模型可望用于含离子液体体系汽液相平衡的预测.A group contribution based molecular thermodynamic model is developed for calculating solvent activity coefficients of ionic liquid solutions.In this model the long range electrostatic interactions among ions,the middle range electrostatic interactions between ion and solvent,and the short range interactions among all species were considered and treated respectively with mean spherical approximation,perturbation theory and UNIFAC group contribution models.The applicability of the model is studied by correlating vapor pressure data for 9 binary systems containing an ionic liquid and water or methanol or ethanol,and the model parameters were determined,viz.molecular diameter of solvent and interaction parameters of all group pairs.It is showed that the activity coefficients of solvents and vapor pressure of the solutions can be represented successfully with average deviation of 1.40% for the binary systems studied,and accordingly prediction of vapor liquid equilibria might be expected for multi-component systems containing ionic liquids.

关 键 词：平均球近似理论 微扰理论 UNIFAC模型 离子液体 汽液平衡 

分 类 号：O642.42[理学—物理化学]