Measurement and correlation of the vapor–liquid equilibrium for methanol + acetonitrile + imidazolium-based ionic liquids at 101.3 kPa. (October 2016)

• Record Type: Journal Article
• Authors: Li, Qing; Zhu, Wei; Liu, Bing; Fan, Zenglu; Zhu, Yumeng; Gao, Ziwei
• Is Part Of: Journal of chemical thermodynamics. Volume 101(2016:Oct.)
• Page Start: 25
• Page End: 30
• Publication Date: 2016-10
• Subjects: Vapor–liquid equilibrium -- Methanol -- Acetonitrile -- 1-Ethyl-3-methylimidazolium tetrafluoroborate -- 1-Octyl-3-methylimidazolium tetrafluoroborate; Thermodynamics -- Periodicals; Thermochemistry -- Periodicals; Thermodynamique -- Périodiques; Thermochimie -- Périodiques; Thermochemistry; Thermodynamics; Periodicals; 541.369
• DOI: 10.1016/j.jct.2016.05.011
• Languages: English
• ISSNs: 0021-9614

Abstract

Highlights: Isobaric VLE data for methanol + acetonitrile + imidazolium-IL were studied. The addition of imidazolium-IL could eliminate the azeotropic point of azeotrope. The separation capacity order for imidazolium-ILs is [OMIM][BF4 ] > [EMIM][BF4 ]. All VLE data were correlated with NRTL and UNIQUAC. Abstract: Two imidazolium-based ionic liquids: 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM][BF4 ]) and 1-octyl-3-methylimidazolium tetrafluoroborate ([OMIM][BF4 ]) were studied as entrainer candidates for the separation of methanol + acetonitrile system. Isobaric vapor–liquid equilibrium (VLE) for the binary methanol + acetonitrile and the ternary mixtures containing imidazolium-based ionic liquids were determined at atmospheric pressure (101.3 kPa). The experimental VLE results indicated ionic liquids (ILs) studied both showed a crossover salting effect for methanol. More importantly, when the amount of IL added increases, the azeotropic point of methanol + acetonitrile will disappear at one specific content. Meanwhile, the separation capacity of imidazolium-based ionic liquids follows the order: [OMIM][BF4 ] > [EMIM][BF4 ]. Finally, two different excess Gibbs free energy models were used to correlate the VLE data: the non-random two-liquid (NRTL), and the universal quasi-chemical (UNIQUAC).