Industrial & Engineering Chemistry Research, Vol.55, No.19, 5736-5747, 2016
Separation of 2-Phenylethanol from Water by Liquid-Liquid Extraction with Ionic Liquids: New Experimental Data and Modeling with Modern Thermodynamic Tools
In this work, ionic liquids (ILs) are proposed as candidates for extractive removal of 2-phenylethanol (PEA) (well-known rose-like aroma compound) from its aqueous solutions. Four ILs based on different cations, namely, 1-hexyl-1-methylpyrrolidinium, 1-hexyl-1,4-diaza [2.2.2]-bicyclooctanium, 1- (2-meth oxyethyl)-3-m ethylimidazolium, and 1-(2-methoxyethyl)-1-methylpyrrolidinium, and bis(trifluoromethylsulfonyl)imide anion were under study. Thermodynamic data at ambient pressure are presented for pure ILs (including temperature-dependent density data and thermal characterization with DSC) as well as for binary systems {IL + water} and ternary systems {IL + PEA + water}. For the binary systems, (liquid + liquid) equilibrium phase diagrams were determined in temperature range T = (280-370) K. For ternary systems, (liquid + liquid) equilibrium was investigated at T = 308.15 K. An impact of the cation structure on the studied properties is established. The data obtained are discussed in terms of the selectivity and distribution ratio of separation of PEA from water. Modeling of the measured properties with two modern chemical engineering thermodynamic tools, namely, nonrandom two liquid (NRTL) model and perturbed-chain statistical associating fluid theory (PC-SAFT), is demonstrated. The NRTL model is applied in a purely correlative fashion in the case of both binary and ternary systems. In turn, the predictive capacity of the PC-SAFT is tested for ternary (liquid + liquid) equilibrium using the combining rules corrections transferred from binary data.