Solid-liquid equilibria of binary mixtures containing high-value compounds and ethyl lactate were studied. Using the gravimetric method, the solubility of various solutes such as caffeine, vanillic acid, ferulic acid, caffeic acid and thymol in ethyl lactate was measured as a function of temperature (temperature range of 298.2 -343.2 K), at atmospheric pressure. The differences in solubility of a given solute in water-saturated and dry ethyl lactate were observed. The deviation of these binary systems from ideal mixture behaviour was discussed.In order to understand the solubilization process, melting properties of pure solutes were determined by differential scanning calorimetry (DSC). The obtained solubility data were represented using UNIQUAC and UNIFAC-based models as well as with the Cubic-Plus-Association (CPA) equation of state. The results of the modeling indicate that these models are the appropriate tools for representing the solubility behaviour of various solutes in ethyl lactate. association equation of state * Maximal standard uncertainties u are u(Tm) = 0.28 K, u(ΔH fus ) = 0.6, u(ΔC p ) = 6.4. a Solid-solid transition of caffeine b Calculated using a group contribution method as described elsewhere [25]. c Calculated using a group contribution method for the estimation of the heat capacities of liquids [38] and the power-law method to estimate heat capacities of organic solids [39].

The alternative solvents poly(ethyleneglycol)s (PEGs) with various molar masses and room temperature ionic liquids (RTILs) AMMOENG100 and 1-butyl-3-methylimidazolium dicyanamide (bmimDCA) were studied for the purpose of extraction of linoleic acid from soybean oil. Liquid-liquid phase equilibrium was measured for binary (PEG þ soybean oil), (RTIL þ soybean oil) as well as ternary (PEG þ soybean oil þ linoleic acid), (RTIL þ soybean oil þ linoleic acid) mixtures, as a function of temperature and composition. The influence on distribution coefficients and separation factor of temperature, initial acid content of the oil and solvent to oil ratio were studied. The effect of molar mass in the case of the PEGs was also examined. The experimental results were modeled using the Peng-Robinson cubic equation of state coupled with the Mathias-Klotz-Prausnitz mixing rule, with good results.

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