Liquid–liquid equilibrium (LLE) data for the methyl isobutyl ketone + o-cresol + water ternary system have been experimentally measured from 298.2 to 323.2 K below 101 kPa. The measured LLE data were verified to be highly consistent through the Othmer–Tobias and Hand equations. The extraction efficiency of methyl isobutyl ketone for o-cresol was assessed by the distribution coefficient and separation factor. The experimental results correlated well with two excess Gibbs energy models: non-random two-liquid and universal quasi chemical, which also yielded binary interaction parameter.

•Mesityl oxide extraction of carboxylic acids showing considerably high efficiency.•General guidelines for screening extractants were derived from comparisons of mesityl oxide with other extractants.•The influence of temperature, solute type and concentration was studied.•Thermodynamic models were used to correlate the experimental data.In this work, liquid-liquid equilibrium (LLE) data for the water + propionic acid or butyric acid + mesityl oxide ternary systems were measured at (298.2 and 323.2) K under atmospheric pressure. The reliability of the experimental tie-line data was verified by the Othmer-Tobias and Hand equations. The distribution coefficient and selectivity, calculated from the LLE data, showed high efficiency for mesityl oxide extracting propionic or butyric acid from the aqueous solution. A comprehensive comparison with various other extractants not only confirmed the high extraction efficiency of mesityl oxide, but also revealed some general guide lines for further screening extractants for carboxylic acids. The experimental data were successfully correlated by both UNIQUAC and NRTL models, yielding binary interaction parameters for relevant process simulations.

•Screening of 40 organic solvents using COSMO-SAC for removing phenol from aqueous systems.•Determining removal abilities of screened solvent to phenol.•Phase behavior further confirmed by using the COSMO-SAC model.•Extraction process simulation was performed for the screened solvents.Solvent extraction is an energy-efficient process to treat phenolic effluents in the industry, and a key step in designing an industrial extraction process is to screen a proper extraction solvent with high extraction efficiency and good physical properties. In this work, COSMO-SAC model was employed to screen the most promising extractant from 40 organic solvents, including alkanes, arenes, ethers, esters and ketones. The screening was performed based on a comparison of selectivity and solvent power, which were derived from the activity coefficient at infinite dilution. Moreover, the σ-profiles of the solvents were used to analyze the interaction between solvents and phenol. Based on the results of screening, three ketones were selected for conducting LLE experiment, and all of them performed very well with high distribution coefficient and high selectivity. The NRTL and UNIQUAC models were successfully applied to correlate the experimental LLE data, with root mean square deviation less than 1.5%. The COSMO-SAC was also used to predict the tie-line data, showing quite good agreement with corresponding experimental data. Finally, the extraction process simulation was performed for the screened solvents. It showed that, the studied ketones are promising solvents for extracting phenol from wastewater. The extraction process treating an effluent with phenol concentration of 5000 ppm was simulated. High separation efficiency (the phenol concentration in the treated water < 10 ppm) can be reached with low stage number (e.g. 4) and solvent usage (e.g. extractant: wastewater = 1:25).

Liquid-liquid equilibrium (LLE) data for the ternary systems, methyl isopropyl ketone (MIPK) + (resorcinol, or hydroquinone) + water, were measured at 298.2, 313.2 and 323.2 K under atmospheric pressure by gas chromatography. The efficiency of MIPK to extract resorcinol or hydroquinone was assessed by the distribution coefficients and separation factors. The LLE data were correlated by the NRTL and UNIQUAC models to yield binary interaction parameters. MIPK was proven to be very promising to extract phenols by comparing its extraction efficiency and physical properties with other extractants used for extracting phenols in industry. The binary interaction parameters of solute pairs, e.g. MIPK-water, calculated from the NRTL or UNIQUAC models were found to agree with corresponding parameters in other LLE systems.