Liquid−liquid equilibrium (LLE) data of the solubility curves and tie-line end compositions were examined for mixtures of water (1) + acetic acid (2) + diethyl succinate or diethyl glutarate or diethyl adipate (3) at 298.15 K and 101.3 ± 0.7 kPa. The reliability of the experimental tie-line data was confirmed by using the Othmer−Tobias correlation. The LLE data of the ternary systems were predicted by UNIFAC method. Distribution coefficients and separation factors were evaluated for the immiscibility region.

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Distribution of butyric acid between water and trioctylamine dissolved in 17 solvents (isoamyl alcohol, 1-nonanol, 1-decanol, 1-dodecanol, oleyl alcohol, methyl ethyl ketone, isopropyl methyl ketone, isobutyl methyl ketone, 4-heptanone, ethyl acetate, cyclohexyl acetate, dimethyl phthalate, dibutyl phthalate, tert-butyl methyl ether, kerosene, n-hexane, toluene) and 4 vegetable oils (haselnut, corn, soybean, olive) have been studied at T = 298.15 K. The highest distribution coefficient for butyric acid is shown by trioctylamine dissolved in isoamyl alcohol. As the molar mass of the alcohol increases, the value of the distribution coefficient decreases. In the amine extraction, it was observed that the use of trioctylamine dissolved in alcohol increased the distribution coefficient between 6 and 7 times; dissolving in ketones increased the distribution between 3 and 5 times; dissolving in esters increased it 4 to 9 times; dissolving in tert-butyl methyl ether increased it 2.3 times; dissolving in hydrocarbons increased it 10 to 18 times; and dissolving in vegetable oils increased it 12.5 times, all as compared to use of the pure solvents as extractant.

-Experimental liquid-liquid equilibria of the water-acetic acid-butyl acetate system were studied at temperatures of 298.15±0.20, 303.15±0.20 and 308.15±0.20 K. Complete phase diagrams were obtained by determining solubility and tie-line data. The reliability of the experimental tie-line data was ascertained by using the Othmer and Tobias correlation. The UNIFAC group contribution method was used to predict the observed ternary liquid-liquid equilibrium (LLE) data. It was found that UNIFAC group interaction parameters used for LLE did not provide a good prediction. Distribution coefficients and separation factors were evaluated for the immiscibility region.

Reactive extraction of levulinic acid has been done at 298.15 K. All experiments are reported on the extraction of levulinic acid by trioctylamine (TOA) dissolved in 11 different ester solvents (ethyl propionate, dimethyl phthalate, hexyl acetate, cyclohexyl acetate, dimethyl adipate, propyl acetate,, dimethyl glutarate, dimethyl fumarate, diethyl sebacate, and diethyl carbonate), as well as single solvents. Experimental results of batch extraction experiments are calculated and reported as distribution coefficients (K D= c̅ HA/c HA,total), loading factors (T T), stoichiometric loading factor (T S), separation factor (S f), and extraction efficiency (E). The diethyl carbonate was found to be the most effective solvent with a maximum distribution value of 5.75. Maximum values of possible equilibrium complexation constants for (acid + amine) (1:1) K 11 and (2:1) K 21 were determined as 3.32 and 32.59 for diethyl carbonate, respectively.

The production of organic acids at relatively low concentrations in aqueous solutions is typical of both electrochemical and biochemical syntheses. The recovery of these solute species can be achieved by solvent extraction, and the reactive recovery of carboxylic acids from aqueous solutions has received increasing attention. In this study the reactive extraction of levulinic acid was done at 298.15 K, and all experiments were reported on the extraction of levulinic acid by Amberlite LA-2 dissolved in five different esters (dimethyl phthalate, dimethyl adipate, dimethyl succinate, dimethyl glutarate, and diethyl carbonate), five different alcohols (isoamyl alcohol, hexan-1-ol, octan-1-ol, nonan-1-ol, and decan-1-ol) and two different ketones (diisobutyl ketone (DIBK) and methyl isobutyl ketone (MIBK)). Furthermore, single pure solvents (not containing Amberlite LA-2) were used for physical extraction. Experimental results of batch extraction experiments were calculated and reported as distribution coefficients (K D), loading factors (T T), stoichiometric loading factors (T S), separation factors (S f) and extraction efficiencies (E). The isoamyl alcohol was found to be the most effective solvent with a maximum distribution value (K D) of 68.017. According to the data determined from the experiments, a linear solvation energy relationship (LSER) model equation was found to calculate loading factors (T T) for the alcohols with an R 2 value of 0.98.

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Levulinic acid, which is a carboxylic acid with a ketone structure, is a clear to brownish semisolid; it melts at 37 C and is soluble in alcohol, ether, and chloroform. Levulinic acid can be used as an acidulant in foods and beverages. The extraction of levulinic acid with trioctylamine (TOA), dissolved in five alcohol solvents (isoamyl alcohol, hexan-1-ol, octan-1-ol, nonan-1-ol, and decan-1-ol) and two ketones (diisobutylketone (DIBK) and methylisobutylketone (MIBK)) were investigated. In addition to these amine systems, experiments were also conducted with single solvents. All measurements were performed at 298.15 K. Organic solutions of amines are being used increasingly to separate organic acids from aqueous mixture solutions via reactive extraction. The extent to which the organic phase may be loaded with levulinic acid is explained by calculating the loading ratio (T), extraction efficiency (E), and distribution coefficients (K D). Isoamyl alcohol was determined to be the most effective solvent, with a maximum distribution value of 11.303. Possible equilibrium complexation constants for acid:amine ratios of 1:1 and 2:1 have been determined, with maximum values of 6.530 and 116.608 for K 11 and K 21, respectively, with isoamyl alcohol. Furthermore, a linear solvation energy relationship (LSER) model equation has been obtained to calculate the distribution coefficients for alcohols, with a correlation coefficient of R 2 = 0.97.