甲醇-碳酸二甲酯-1-辛基-3-甲基咪唑四氟硼酸盐物系的等压汽液平衡测定及UNIFAC关联  

Vapor-Liquid Equilibrium for Methanol-Dimethyl Carbonate-1-Octyl-3-Methylimidazolium Tetrafluoroborate System

作　　者：付永泉[1] 朱炜[1] 王海川[1] 曹玲[1] 李群生[1] 

机构地区：[1]北京化工大学化学工程学院,北京100029

出　　处：《石油化工》2012年第8期911-915,共5页Petrochemical Technology

基　　金：中央高校教育基金项目(JL1101);国家高技术研究发展计划项目(2008AA062401)

摘　　要：在101.32 kPa下,用改进的Othmer汽液平衡釜测定了甲醇-碳酸二甲酯(DMC)-1-辛基-3-甲基咪唑四氟硼酸盐([omim]BF4)物系的等压汽液平衡数据;采用UNIFAC方程对实验数据进行了关联,得到了新基团—OCOO—与—CH2—,CH3OH,—[mim]BF4基团间的UNIFAC作用参数。与传统基团划分的UNIFAC模型关联结果相比,采用新基团划分法推算得到的汽液平衡数据与实验值偏差更小。实验结果表明,加入离子液体[omim]BF4使汽液平衡线偏离甲醇-DMC二组分物系的汽液平衡线,[omim]BF4含量越大,偏离程度越大;[omim]BF4具有明显的盐析效应,能消除甲醇-DMC物系的共沸点;[omim]BF4可作为甲醇-DMC物系萃取精馏的溶剂;UNIFAC方程可用于预测甲醇-DMC-[omim]BF4物系的汽液平衡。Isobaric vapor-liquid equilibrium（VLE） of methanol-dimethyl carbonate（DMC）-1-octyl-3-methylimidazolium tetrafluoroborate（BF4） system was measured at 101.32 kPa using a modified Othmer still.The results show that the ionic liquid BF4 exhibits notable salt-out effect which can enhance the relative volatility and eliminate the azeotropic point.The relative volatility of the system increased with the mole fraction of BF4.It is concluded that BF4 can be used as a solvent in the extractive distillation for methanol-DMC system.The UNIFAC model was used to relate the VLE data,and the UNIFAC interaction parameters between the group —OCOO— and the groups —CH2—,CH3OH,—BF4 are obtained.UNIFAC equation can be employed to predict the vapor-liquid equilibrium of methanol-DMC-BF4 system.

关 键 词：甲醇 碳酸二甲酯 1-辛基-3-甲基咪唑四氟硼酸盐 汽液平衡 离子液体 

分 类 号：TQ013.1[化学工程]