The solubility of sodium thioglycolate in five pure solvents of water, methanol, ethanol and isopropyl alcohol, n-propanol and four binary solvent mixtures (water + methanol, water + ethanol, water + isopropyl alcohol, water + n-propanol) was determined within the temperature range from (293.15 to 333.15) K by using the gravimetrical method under atmospheric pressure (p = 0.1 MPa). The solubility of sodium thioglycolate in water, ethanol, isopropyl alcohol, and n-propanol increases with a rise of temperature, but the solubility decreases in methanol with increasing temperature. Meanwhile, in the binary solvent mixtures (water + methanol, water + ethanol, water + isopropyl alcohol, water + n-propanol), the solubility of sodium thioglycolate increases with increasing the mole fraction of water and with temperature. The modified Apelblat equation and van’t Hoff equation were applied to correlate the solubility of sodium thioglycolate in the five pure solvents, while in the binary solvent mixtures, the solubility was correlated by the modified Apelblat equation, CNIBS/R-K model, and Jouyban–Acree model. It was shown that the correlated results were in better agreement with the experimental data. Also, the mixing thermodynamic properties for sodium thioglycolate in the binary solvent mixtures were calculated.

To separate the azeotropes of hexane + ethanol/1-propanol, two ionic liquids [HMIM][BF4] and [HMIM][OTf] were adopted as extractive agents. The corresponding ternary liquid–liquid equilibrium data for the mixtures of hexane + ethanol + [HMIM][BF4], hexane +1-propanol + [HMIM][BF4], and hexane +1-propanol + [HMIM][OTf] were measured at 298.15 K and 101.3 kPa. The distribution coefficient (B) and selectivity (S) were obtained to evaluate the separation performance of the selected extractants to extract ethanol/1-propanol from the azeotropes. Meanwhile, the influence of the ILs’ anions and the alcohol carbon chain length were investigated. In addition, the nonrandom two-liquid (NRTL) and universal quasichemical activity coefficient (UNIQUAC) models were adopted to correlate the ternary liquid–liquid equilibrium data, and the binary interactive parameters were regressed. Also, the calculated results of the models agreeed with the measured data. Meanwhile, the binodal curves of the ternary systems were predicted using the universial functional activity coefficient (UNIFAC) model.

•The LLE data and solubility for water + TGA + different solvents were measured.•The distribution coefficient and selectivity were calculated.•The reliability of LLE data were verified by the Othmer-Tobias and Hand equations.•The NRTL and UNIQUAC models were applied to correlate the experimental LLE data.Liquid-liquid equilibrium (LLE) data for the ternary systems {water + thioglycolic acid + (butyl acetate, isobutyl acetate or isopropyl acetate)} were determined at 293.15 K and 101.3 kPa. The solubility values were obtained by using the titration method. Moreover, the Hand and Othmer-Tobias equations were applied to validate the reliability of the obtained LLE values, and the distribution coefficients and separation factors were calculated to evaluate the solvents performances to extract thioglycolic acid from aqueous solution. The results indicate that isobutyl acetate is the best among the organic solvents studied for the separation of thioglycolic acid from aqueous solution. The thermodynamic NRTL and UNIQUAC models were used to correlate the experimental LLE results for the systems studied, and the binary interaction parameter values of the two models were optimized from the LLE correlation.

•Isobaric VLE data of the systems TFP + water/chloroform/p-xylene were measured at 101.3 kPa.•The thermodynamic consistency of the VLE data was checked by four methods.•The experimental VLE data were well correlated by the NRTL, UNIQUAC, and Wilson model.•The two flowsheets to separate the azeotrope of TFP + water were presented.In this work, chloroform and p-xylene were selected as azeotropic agents to separate the azeotrope of {2,2,3,3-tetrafluoro-1-propanol (TFP) + water} by azeotropic distillation. The isobaric vapour-liquid equilibrium data for the binary systems of (TFP + water), (TFP + chloroform), and (TFP + p-xylene) were determined at 101.3 kPa by a modified Rose type recirculating still. The thermodynamic consistency of the experimental data was checked by the Herington, van Ness, infinite dilution, and pure component consistency method. The experimental results were correlated by the NRTL, UNIQUAC and Wilson activity coefficient models, and the binary interaction parameters of the three models were regressed. All the correlated results by the NRTL, UNIQUAC, and Wilson models show good agreement with the experimental data. Furthermore, the distillation synthesis ternary maps for the systems (TFP + water + chloroform) and the (TFP + water + p-xylene) were obtained with the regressed interaction parameters of the NRTL model, and two distillation processes were presented to separate the azeotrope of (TFP + water).

•Three acidic imidazolium-based ILs were selected to separate pyridine.•LLE data of ILs + pyridine + methylbenzene were determined at 298.15 K under 101.3 kPa.•Interaction energies between the ILs, and pyridine and methylbenzene respectively were calculated.•The phase diagrams for the ternary systems were classified as Treybal's Type 1.For the purpose of selecting the effective solvents to separate basic N-compound pyridine from coal tar, three acidic imidazolium-based ILs, 1-butyl-3-methylimidazolium hydrogen sulfate, [Bmim][HSO4], 1-butyl-3-methylimidazolium dihydrogen phosphate, [Bmim][H2PO4], and 1-butyl-3-methylimidazolium perchlorate, [Bmim][ClO4], were chosen for the extraction process. The liquid-liquid equilibrium tie-line data for the ternary systems of [Bmim][HSO4], [Bmim][H2PO4] and [Bmim][ClO4] + pyridine + methylbenzene were measured at T = 298.15 K under 101.3 kPa. Meanwhile, the interaction energies between the ILs, and pyridine and methylbenzene respectively were calculated. The results indicated that the selected ILs had strong interactions with pyridine than with methylbenzene, which were also verified by the distribution ratio and selectivity calculated from the experimental data. In addition, the experimental LLE data were correlated by the NRTL and UNIQUAC models, and the NRTL model showed good agreement in correlation than the UNIQUAC. The average RMSDs for the NRTL and UNIQUAC models of the investigated systems are 0.0153 and 0.0161, respectively.

The isobaric vapor–liquid equilibrium (VLE) data for the systems (thioglycolic acid + water), (thioglycolic acid + butyl acetate), (thioglycolic acid + butyl formate), and (thioglycolic acid + isobutyl acetate) were measured at P = 101.3 kPa by using a vapor recirculating type (modified Rose) equilibrium still. The thermodynamic consistency test of the experimental data for the four binary systems were confirmed by the method of Van Ness. The experimental VLE data were correlated by the three activity coefficient models of Wilson, nonrandom two-liquid (NRTL), and universal quasi-chemical (UNIQUAC). The results show that all the calculated data by the Wilson, NRTL, and UNIQUAC models are in good agreement with the measured VLE data. Meanwhile, the binary interaction parameters of the three models for the binary systems were regressed.

•The LLE data for water + (ethanol/1-propanol) + [Dmim][NTf2] were determined at 298.15 K under atmospheric pressure.•The phase diagrams for the ternary systems were classified as Treybal’s Type I behavior.•The LLE data were successfully correlated by the NRTL and the UNIQUAC models, respectively.•Influence of alcohols with different length of alkyl chain were revealed by D and S of the alcohols.Liquid-liquid phase equilibria for ternary systems of water + (ethanol/1-propanol) + 1-decyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide ([Dmim][NTf2]) were measured at T = 298.15 K and atmospheric pressure. Influences of alcohols with different length of alkyl chain on the liquid-liquid equilibria were revealed by the distribution coefficient and selectivity of the alcohols. The phase diagrams for the ternary systems were classified as Treybal's Type I behavior. The experimental data of ternary liquid-liquid equilibria were correlated by the nonrandom two liquid (NRTL) and the universal quasi-chemical (UNIQUAC) models, in which the interaction parameters were optimized. The values of root-mean-square deviation between the experimental and the calculated data show that those models can correlate the experimental data of the studied systems with good accuracy.

The ternary liquid–liquid equilibrium (LLE) experimental data for the system isopropyl acetate + ethanol + water have been measured at (293.15, 313.15, 333.15) K under pressure of 101.3 kPa in this work. The quality of the determined experimental data was checked by the Bachman and Hand equations, which the correlation coefficients of the Bachman equation were 0.9964, 0.9997, and 0.9994, and the those of the Hand equation were 0.9717, 0.9846, and 0.9934 for (293.15, 313.15 and 333.15) K. Moreover, the measured data were correlated by the nonrandom two-liquid (NRTL) and universal quasi-chemical (UNIQUAC) activity coefficient equations, and the parameters of the two equations were regressed. The comparison between the correlated values and the measured data was made, which the correlated values agree well with the determined LLE data. Meanwhile, the selectivity (S) and distribution coefficient (D) for this ternary system were calculated from the experimental data.

In this work, the isobaric vapor–liquid equilibrium (VLE) data for binary mixtures of 2,2,3,3-tetrafluoro-1-propanol (TFP) + 2,2,3,3,4,4,5,5-octafluoro-1- pentanol (OFP) were determined at pressures of 53.3, 66.7, and 80.0 kPa by a modified Rose type recirculation still. The thermodynamic consistency of all the VLE data was checked by Herington and Van Ness test to confirm the reliability of the experimental data. No azeotropic behavior was observed for the binary systems at different pressures. Meanwhile, the VLE data were correlated by Wilson and nonrandom two-liquid (NRTL) activity coefficient models, which the calculated results were in good agreement with the experimental data. Also, the binary interaction parameters of the activity models were regressed.

Ternary liquid–liquid equilibrium (LLE) data of 2,2,3,3,4,4,5,5-octafluoro-1-pentanol + methanol + water were measured at (298.15, 308.15, and 318.15) K under atmospheric pressure. Both the Bachman and the Hand equations were applied to check the reliability of the tie-line data, and their correlation coefficient (R2) were all close to 1. Meanwhile, the nonrandom two-liquid (NRTL) activity coefficient model was applied to correlate the experimental data, which the results showed good agreement with the measured LLE data, and the binary interaction parameters were regressed. In addition, the distribution coefficients and separation factors were determined by using the experimental data and discussed in detail.

Isobaric vapor–liquid equilibrium (VLE) data for three binary systems of (allyl alcohol + water), (allyl alcohol + methanol), and (allyl alcohol + ethanol) were measured at atmospheric pressure of 101.3 kPa by a modified Rose vapor recirculating type equilibrium still. The thermodynamic consistency test for the experimental data of the three binary systems containing allyl alcohol were checked by Herington method and van Ness test, respectively. Meanwhile, the measured VLE data were correlated by three activity coefficient models of Wilson, nonrandom two-liquid (NRTL), and universal quasichemical (UNIQUAC), for which all of the calculated results showed good consistency. The binary interaction parameters of the models were also regressed. The azeotropic behavior could not be observed in (allyl alcohol + methanol) and (allyl alcohol + ethanol) systems, but for (allyl alcohol + water) system, the azeotropic behavior was found, and it had the minimum azeotropic point.

•The measurement of density and viscosity for two fluoro alcohols were carried out.•The density and viscosity data were correlated and good agreement were obtained.•Isobaric VLE data of two fluoro alcohol systems were measured at 101.3 kPa.•The experimental VLE data were well correlated with the Wilson and NRTL model.•The excess Gibbs free energies GE were estimated in this work.The measurements of density, viscosity for 2,2,3,3-tetrafluoro-1-propanol, 2,2,3,3,4,4,5,5-octafluoro-1-pentanol are reported at different temperatures and pressure of 101.3 kPa. The experimental values of densities and viscosities of the above two fluoro alcohols were correlated successfully by a second-order polynomial and by a Vogel–Tammann–Fulcher equation, respectively. Meanwhile, isobaric vapour-liquid equilibrium results for two binary systems of (methanol + 2,2,3,3,4,4,5,5-octafluoro-1-pentanol) and (2,2,3,3-tetrafluoro-1-propanol + 2,2,3,3,4,4,5,5-octafluoro-1-pentanol were determined by a modified Rose type still. Both the Herington area method and the van Ness point to point test method were adopted to confirm the thermodynamic consistency of the experimental VLE findings, for which the test results showed good thermodynamic consistency. The Wilson and non-random two-liquid (NRTL) activity coefficient models were used to correlate the measured VLE values at different temperatures. The correlation results indicate good agreement with the experimental values. Also the binary interaction parameters of the two activity coefficients models were regressed. With the calculation of GE, the negative deviation behaviour was observed for the two binary systems.

Liquid–liquid equilibrium (LLE) data for the ternary system 2,2,3,3,4,4,5,5-octafluoro-1-pentanol + ethanol + water have been reported at (298.15, 308.15, and 318.15) K and 0.1 MPa. The Bachman equation and the Hand equation were used to confirm the reliability of the experimental tie-line data. The experimental data were correlated by the nonrandom two-liquid (NRTL) model, for which the calculated results show good agreement with the ternary LLE data, and the binary interaction parameters of NRTL model were also regressed. Moreover, the distribution coefficients and separation factors in the ternary system were determined by the experimental data.

Liquid–liquid equilibrium (LLE) data for the ternary system water + 2-methyl-1-propanol + butyl acetate and water + 2-methyl-2-propanol + butyl acetate were measured at the temperature T = (298.15 and 323.15) K and under atmospheric pressure, respectively. Both the Othmer–Tobias and Bachman equations were used to test the reliability of the experimental data. Moreover, the NRTL and UNIQUAC activity coefficient models were applied to correlate the determined data, and the result showed that the UNIQUAC and the NRTL models both could correlate the two systems studied well at the same conditions. In addition, distribution ratios and separation factors in the two ternary systems were calculated using the equations from the experimental liquid liquid equilibrium data and discussed in detail.

Vapor−liquid equilibria (VLE) data for acetic acid + benzene, chloroacetic acid + benzene, and dichloroacetic acid + benzene binary systems have been measured at 101.33 kPa using a recirculating still. The experimental data were checked with the Herington method, which showed thermodynamic consistency. The Wilson, nonrandom two-liquid (NRTL), and universal quasi-chemical (UNIQUAC) activity coefficient models, combined with the Hayden−O’Connell equation, to account for the nonideality of the vapor phase due to the association of the acetic acid, were used to correlate the VLE data. The Wilson model correlated the experimental results better than the NRTL and UNIQUAC models.

•LLE data of ethyl acetate/isopropyl acetate + 2,2,3,3-tetrafluoro-1-propanol + water were determined.•The biphasic area decreased with the increasing of temperature.•LLE data were correlated by the NRTL and UNIQUAC models.•Distribution coefficients and selectivities were calculated.•Isopropyl acetate shows higher extraction ability at the same composition range.The liquid-liquid equilibrium (LLE) data for the ternary systems of ethyl acetate + 2,2,3,3-tetrafluoro-1-propanol + water and isopropyl acetate + 2,2,3,3-tetrafluoro-1-propanol + water were measured at T = 298.15 K and T = 318.15 K under 101.3 kPa. Bachman and Hand equations were selected to check and confirm the reliability of the measured tie-line data, and the correlation coefficient (R2) were all close to 1. Meanwhile, the distribution coefficient and separation factor were calculated and discussed in detail. In addition, the nonrandom two-liquid (NRTL) and universal quasi-chemical (UNIQUAC) activity coefficient models were applied to correlate the experimental data, and the RMSD values for the two models obtained are 0.0104, 0.0104 correlated by NRTL, and 0.0077, 0.0128 by UNIQUAC, respectively, which indicate that the experimental LLE data can be successfully correlated by both the NRTL and the UNIQUAC models. Also, the corresponding binary interaction parameters were regressed. The correlated model parameters could be applied for the optimization and design of the separation process.

•The selected ILs shows good extraction performance for neutral N-compounds.•The mechanism of the extraction was confirmed to be the formation of hydrogen bond.•BmimCl can be easily regenerated and recycled with good performance even 5 times.•A green approach was provided for the separation of neutral N-compounds from coal tar.Coal tar is one of the valuable chemical materials and energy, from which the nitrogen-containing compounds (N-compounds), indole, carbazole, pyridine, and quinoline, are mainly separated. In the present work, the imidazolium-based ILs with different anions, 1-butyl-3-methyl-imidazolium chloride (BmimCl), 1-butyl-3-methyl-imidazolium bromide (BmimBr), 1-butyl-3-methyl-imidazolium tetrafluoroborate (BmimBF4), 1-butyl-3-methyl-imidazolium disulfate (BmimHSO4), and 1-butyl-3-methyl-imidazolium acetate (BmimCH3COO), were used to separate those N-compounds via extraction. The performances of ILs extraction were evaluated by the extraction efficiency and distribution coefficient. High extraction efficiency and selectivity could be found for the neutral N-compounds, indole and carbazole, by BmimCl than basic N-compounds, pyridine and quinoline. Meanwhile, the optimized conditions were ascertained and the selected ILs could be easily regenerated by water and be sustainable recycled by a back-extraction process. Furthermore, a hydrogen bond was formed between the neutral N-compound and the selected ILs, and the mechanism was confirmed based on the analysis by a molecular simulation. Thus, an approach was provided for the separation of neutral N-compounds from coal tar.