Separation of ethanol–water mixtures by liquid–liquid extraction using phosphonium-based ionic liquids

Liquid–liquid equilibria for ternary mixtures of water + 2-propanol + 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ionic liquids at 298.15 K

“…Neves et al [31] showed the separation of ethanol of water using phosphonium-based ILs by liquid-liquid extraction. Dharamashi Rabari et al [34] obtained successful recovery of butanol and propanol from aqueous solution by introducing phosphonium-based ILs that has density lower than water.…”

“…For example, H Ghanadzadeh Gilani et al [7] investigated ternary equilibrium data of mixtures consisting of 2-butanol, water, and heavy alcohols at T = 298.15 K. Amparo Cháfer et al [14] presented LLE data of systems 4-methyl-2-pentanone + water + 1-propanol, 2-propanol. Comparing with the organic solvent, ionic liquids (ILs) have been causing researchers' attention in the application of LLE containing alcohols and water [2,19,[22][23][24][25][26][27][28][29][30][31][32][33][34] for their advantages, such as negligible vapor pressure, non-flammability, and tunable physiochemical properties [35]. For example, Catarina M. S. S.…”

Surface tensions of ionic liquids: Non-regular trend along the number of cyano groups

“…Since then, a large interest on their application has emerged, comprising the application of cyano-based ILs as fluoro-free alternatives in the development of lithium-conducting electrolytes [19,20], and in organic dye-sensitized solar cells [21]. Cyano-based ILs have also been studied as alternative solvents in separation approaches, namely in the extraction of aromatics from aromatic/aliphatic mixtures [22], in the extraction of phenolic compounds from biomass [23], in the selective separation of CO 2 and N 2 (using supported IL membranes) [24], and in the separation and recovery of alcohols from aqueous media [14,25]. For a better design of these processes, the solvation capacity and ability to establish hydrogen bonds with water and ethanol [26,27], the volumetric properties of binary mixtures composed of benzene and cyano-based ILs [28], and thermophysical properties, such as densities, viscosities and refractive index [29] of these CN-based fluids, have been evaluated.…”

“…Furthermore, the possibility of tuning their properties, through the simple combination of different ions, allows the design of specific ILs for target applications. As a result of their tailoring ability and unique properties, ILs have been studied for various application, such as lubricants [7], gas storage media [8,9], solvents in multiphasic homogeneous catalytic reactions [5,10], solvent media and catalysts in heterogeneous reactions [11], extraction solvents of compounds of biotechnological and analytical interest [12,13], potential solvents in extractive distillation processes to separate water-ethanol mixtures [14], enhanced candidates to dissolve and process biomass [15], among many other exploratory purposes. Notwithstanding their academic interest, ILs have caught the industry interest and are currently being used in some industrial processes and products [16,17].…”

Mutual solubilities between water and non-aromatic sulfonium-, ammonium- and phosphonium-hydrophobic ionic liquids

“…For instance, for the latter application, Simoni et al 13 have shown that hydrophobic ILs are capable of extracting 1-butanol from aqueous solutions with a selectivity up to 300-fold. Neves et al 15 suggested that phosphonium-based ILs are also potential alternatives for the extraction of ethanol from fermentation broths. In this respect, mutual solubilities of ILs and water are essential for the design and development of separation processes and they are also important for the evaluation of their environmental impact.…”