Phase equilibrium in binary systems of ionic liquids, or deep eutectic solvents with 2-phenylethanol (PEA), or water

•Separation processes of 2-phenylethanol from water.•Phase equilibria in binary systems of (IL, or DES + 2-phenylethanol, or water) were measured.•Pyrrolidynium-, imidazolium-, and phosphonium-based ILs were used.•Three ILs may be suggest to the further technological investments: [BMPYR][FAP] > [P6,6,6,14][TCM] > [BMPYR][TCB].•Two DES is proposed as entrainer: (choline chloride + oxalic acid) < (acetylocholine chloride + 1,10-decanediol).

The production of 2-phenylethanol (PEA), an important flavor and fragrance compound, with a rose-like odor has been significantly increased last decade. The aim of this study was to propose a new ionic liquids (ILs) and Deep Eutectic Solvents (DES) as an entrainers in a biphasic systems in possible bioproduction of PEA. ILs and DESs reveal many unique properties which make them very interesting for applications in modern ‘green’ technologies. In present contribution we have reported new experimental results on (solid, or liquid + liquid) phase equilibrium (SLE/LLE) measurements of eight binary systems composed of pyrrolidinium-based, imidazolium-based and phosphonium-based ILs (namely: 1-butyl-1-methylpyrrolidinium tricyanomethanide, [BMPYR][TCM], 1-butyl-1-methylpyrrolidinium tetracyanoborate, [BMPYR][TCB], 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate (triflate), [BMPYR][CF3SO3], 1-butyl-1-methylpyrrolidinium tris(pentafluoroethyl)trifluorophosphate, [BMPYR][FAP], and 1-butyl-1-methylpyrrolidinium dicyanamid, [BMPYR][DCA], 1-butyl-1-methylimidazolium tricyanomethanide, [BMIM][TCM] and trihexyl-tetradecyl-phosphonium tricyanomethanide, [P6,6,6,14][TCM] with PEA and water. The complete miscibility with PEA was observed for [BMPYR][FAP], [BMPYR][DCA] and [BMIM][TCM]. The best solubility of solid IL in PEA was found for [BMPYR][TCM]. Complete miscibility with water was observed for [BMPYR][CF3SO3] and [BMPYR][DCA]. Moreover, new results on SLE/LLE of six binary systems of DES: {choline chloride + resorcinol (1:4), or phenylacetic acid (1:1), or phenylacetic acid (1:2), or oxalic acid (1:1), or malonic acid (1:1)} and {acetylocholine chloride + 1,10-decanediol} are shown. The initial information of the eutectic temperature and composition was found for {acetylocholine chloride + 1,10-decanediol}. Complete miscibility with PEA was observed only for {choline chloride + malonic acid (1:1)}. Simple eutectic systems of phase behavior with complete miscibility in the liquid phase for all the later mixtures were observed. The solubility of DES in water reveals SLE/LLE phase equilibrium. The best solvent was {choline chloride + malonic acid (1:1)}. The modeling of liquidus curves of ILs in PEA was proposed with excess Gibbs energy model, NRTL. It correlates the solubility with the average root mean square deviation, σT = 0.78 K. To our best knowledge this is the very first paper when the SLE/LLE of PEA and water have been tested for systems with ILs and DESs.

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