甲醇-苯-离子液体等压汽液平衡数据的测定  

Isobaric vapor-liquid equilibrium data for methanol-benzene-ionic liquid ternary systems

作　　者：李群生[1] 马各土夫[1] 朱炜[1] 付永泉[1] 李仑[1] 

机构地区：[1]北京化工大学化学工程学院,北京100029

出　　处：《北京化工大学学报（自然科学版）》2011年第3期12-16,共5页Journal of Beijing University of Chemical Technology(Natural Science Edition)

基　　金：国家"863"计划(2006BAI09B07-01);国家"973"计划(2007CB714304)

摘　　要：在101.32kPa下,用改进的Othmer釜测定了甲醇-苯与三种离子液体的三元物系的等压汽液平衡数据,即甲醇-苯-1-乙基-3-甲基咪唑四氟硼酸盐([EMIM]BF4),甲醇-苯-1-丁基-3-甲基咪唑四氟硼酸盐([BMIM]BF4),甲醇-苯-1-辛基-3-甲基咪唑四氟硼酸盐([OMIM]BF4)。实验结果表明,加入离子液体可以使汽液平衡线偏离甲醇-苯二组分物系的汽液平衡线,离子液体摩尔分数越大,偏离程度越大。[OMIM]BF4表现出明显的盐析效应,使甲醇对苯的相对挥发度发生改变,消除了甲醇—苯物系的共沸点。离子液体对甲醇的盐析效应顺序为:[OMIM]BF4>[BMIM]BF4>[EMIM]BF4。因此[OMIM]BF4可以作为甲醇-苯物系萃取精馏的溶剂。Isobaric vapor-liquid equilibrium data for methanol-benzene-ionic liquid ternary systems have been measured at 101.32 kPa using a modified Othmer still.The ionic liquids employed were 1-ethyl-3-methylimidazolium tetrafluoroborate（BF4）,1-butyl-3-methylimidazolium tetrafluoroborate（BF4） and 1-octyl-3-methylimidazolium tetrafluoroborate（BF4）.The vapor-liquid equilibrium curves of the methanol-benzene-ionic liquid systems deviate from that of the IL-free system and the deviation increases with increasing amounts of IL.The BF4 shows a salt-out effect,which increase the volatility of methanol relative to that of benzene,and even leads to an elimination of the azeotropic point.The salting-out effect on methanol decreases in the order： BF4 BF4 BF4.As a result,it is concluded that BF4 can be used as an entrainer for the separation of methanol and benzene,and the VLE data obtained here can be used to optimize the process.

关 键 词：甲醇 苯 汽液相平衡 1-乙基-3-甲基咪唑四氟硼酸盐 1-丁基-3-甲基咪唑四氟硼酸盐 1-辛基-3-甲基咪唑四氟硼酸盐 

分 类 号：TQ013.1[化学工程]