Ionic liquids have awakened a big interest as solvents in the last years. In this work, the possibility of using an ionic liquid as solvent for the citrus essential oil deterpenation by liquid-liquid extraction has been studied. Citrus essential oil was simulated as the binary mixture (limonene + linalool) and equilibrium data for limonene + linalool + 1-ethyl-3-methylimidazolium ethylsulfate ([emim][EtSO4]) have experimentally been measured at 298.15 and 318.15 K. The experimental technique is based on direct analysis of phases at equilibrium using 1H NMR, which allows quantitative analysis of the three compounds. Linalool distribution ratios and selectivities have been calculated from experimental data. Slightly bigger values of these parameters were found at the lowest temperature. Correlation of the experimental LLE data was done by means of the non-random two-liquid (NRTL) equation. The nonrandomness parameter ([alpha]) was fixed to 0.1, 0.2, and 0.3, and the best results were obtained with [alpha] = 0.1. Correlation is performed for each temperature data set and also for both data sets simultaneously, getting in all the cases an adequate correlation.

(Liquid + liquid) equilibrium (LLE) data for 1-methyl-3-octylimidazolium bis[trifluoromethylsulfonyl]imide + thiophene + n-dodecane and 1-methyl-3-octylimidazolium bis[trifluoromethylsulfonyl]imide + thiophene + cyclohexane ternary systems have been determined experimentally at 298.15 K. The compositions of the tie-lines ends have been obtained by gas chromatographic analysis of phases at equilibrium, being distribution coefficients and separation factors calculated from them. The experimental results have been correlated by means of the NRTL model but considerable deviations from experimental data were found.

Abstract: Isothermal vapor-liquid equilibrium data were measured at 333.15 and 363.15 K for the systems toluene + phenol, toluene + 2-cresol, toluene + 3-cresol, toluene + 4-cresol, octane + 2-cresol, octane + 3-cresol, water + phenol, and water + 3 cresol. Additionally, heteroazeotropic data of water + 2-cresol and water + 4-cresol were determined. The solubility of water in 2-cresol, 3-cresol, and 4-cresol was measured by photometric turbidity titration. Excess molar volumes for the systems toluene + phenol or cresols and octane + 2 cresol or + 3 cresol are presented together with Redlich-Kister polynomial fits. The VLE data and, if present, LLE data have been regressed according to the models NRTL, UNIQUAC, and Elliott Suresh Donohue equation of state together with data from the literature.

Experimental data on solid-liquid equilibrium for three cuts in the ternary system acetic acid-propanoic acid-formamide are presented. In the system two adductive compounds exist: 2:1 adduct (CH3COOH)2·HCONH2 and 1:2 adduct CH3CH2COOH·(HCONH2)2. Liquidus for acetic acid-propanoic acid mole ratios 1:1, 1:3 and 3:1 is given and confronted with liquidus calculated on the basis of binary systems behavior. \copyright 2007 Elsevier B.V. All rights reserved.

Solid-liquid equilibria in the system propanoic acid-formamide were determined from time-temperature cooling and warming curves. In the system, two solid adducts, stable and metastable, were found and their equilibrium dissociation constants were calculated. \copyright 2007 Institute of Organic Chemistry and Biochemistry.

Solid-liquid (s-l) and liquid-liquid (l-l) equilibrium was determined in the binary system formamide-acetophenone. The s-l equilibrium was measured by recording time-temperature cooling and warming curves. The l-l equilibrium was obtained in a wide range of temperatures by the turbidity method. A considerable supercooling preceding solidification made it possible to examine metastable l-l equilibrium yet at temperatures lower than the solidus ones. Activity coefficients evaluated from the stable region of l-l equilibrium were correlated by Nova?k?s modification of the Wilson equation. Calculation of the s-l equilibrium was performed with the obtained parameters. Heat capacity of solid and liquid acetophenone was measured and its dependence on temperature is given. The transition enthalpy betwen two solid modifications of acetophenone is also given. \copyright 2006 Institute of Organic Chemistry and Biochemistry.

Solid-liquid equilibrium in the binary systems acetic acid-cyclohexane and acetic acid-trichloroacetic acid was determined from time-temperature cooling and heating curves. The first system shows an eutectic point at x1?0.08 and T=271.9K. In the second system, a solid compound (1:1) was found and an equilibrium constant of the compound dissociation was calculated. \copyright 2003 Elsevier B.V. All rights reserved.