Effect of ionic liquids on (vapor + liquid) equilibrium behavior of (water + 2-methyl-2-propanol)

Isobaric T, x, y data were reported for ternary systems of {water + 2-methyl-2-propanol (tert-butyl alcohol, TBA) + ionic liquid (IL)} at p = 100 kPa. When the mole fraction of TBA on IL-free basis was fixed at 0.95, measurements were performed at IL mass fractions from 0.6 down to 0.05, in a way of repeated synthesis. The vapor-phase compositions were obtained by analytical methods and the liquid-phase compositions were calculated with the aid of mass balances. Activity coefficients of water and TBA were obtained without the need of a thermodynamic model of the liquid-phase. Six ILs, composed of an anion chosen from [OAc]^? or [Cl]^?, and a cation from [emim]⁺, or [bmim]⁺, or [hmim]⁺, were studied. Relative volatility and activity coefficients were presented in relation with the IL mole fraction, showing the effect of the ILs on a molar basis. The effect of the ILs on relative volatility of TBA to water was depicted by the effect of anions and cations on, respectively, the activity coefficients of water and TBA. The results indicated that, among the six ILs studied, [emim][Cl] has the most significant effect on enhancement of the relative volatility, which reaches a value of 7.2 at an IL mass fraction of 0.58. Another IL, [emim][OAc], has also significant effect, with an appreciable value of 5.2 for the relative volatility when the IL mass fraction is 0.6. Considering the relatively low viscosity and melting point of [emim][OAc], it might be a favorable candidate as solvent for the separation of water and TBA by extractive distillation. Simultaneous correlation by the NRTL model was presented for both systems of (water + ethanol + IL) and (water + TBA + IL), using consistent binary parameters for water and IL.     

Phase equilibria for liquid mixtures of (benzonitrile + a carboxylic acid + water) atT = 298.15 K

(Liquid  +  liquid) equilibrium data are presented for mixtures of {benzonitrile(1)  +  acetic acid or propanoic acid or butanoic acid or 2-methylpropanoic acid or pentanoic acid or 3-methylbutanoic acid(2)  +  water(3)} atT =  298.15 K. The relative mutual solubility of each of the carboxylic acids is higher in the benzonitrile layer than in the aqueous layer. The influence of 3-methylbutanoic acid, pentanoic acid, 2-methylpropanoic acid, and butanoic acid on the solubility of the hydrocarbons in benzonitrile is greater than that of the acetic and propanoic acids. Three three-parameter equations have been fitted to the binodal curve data. These equations are compared and discussed in terms of statistical consistency. The NRTL and UNIQUAC models were used to correlate the experimental tie lines and to calculate the phase compositions of the ternary systems. The NRTL equation fitted the experimental data far better than the UNIQUAC equation. Selectivity values for solvent separation efficiency were derived from the tie line data.     

(Liquid + liquid) equilibrium for the ternary systems {heptane + toluene + 1-allyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide} and {heptane + toluene + 1-methyl-3-propylimidazolium bis(trifluoromethylsulfonyl)imide} ionic liquids

The (liquid + liquid) equilibrium (LLE) data for two systems containing heptane, toluene, and 1-methyl-3-propylimidazolium bis(trifluoromethylsulfonyl)imide ([mpim][Tf₂N]) or 1-allyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([amim][Tf₂N]) ionic liquids (ILs) were determined at T = 313.2 K and atmospheric pressure. The effect of a double bond in an alkyl side chain in the imidazolium cation was evaluated in terms of selectivity and extractive capacity. The results show a decrease of the amount of toluene and heptane dissolved in the IL with the allyl group. Thus, the distribution ratios of toluene and heptane of [mpim][Tf₂N] IL are higher than those of [amim][Tf₂N] IL. On the other hand, the separation factor of the [amim][Tf₂N] IL increases comparing to [mpim][Tf₂N] IL. The NRTL model was used to correlate satisfactorily the experimental LLE data for the two studied ternary systems.     

(Vapour + liquid) equilibria,volumetric and compressibility behaviour of binary and ternary aqueous solutions of 1-hexyl-3-methylimidazolium chloride,methyl potassium malonate,and ethyl potassium malonate

(Vapour + liquid) equilibrium data (water activity, vapour pressure, osmotic coefficient, and activity coefficient) of binary aqueous solutions of 1-hexyl-3-methylimidazolium chloride ([C₆mim][Cl]), methyl potassium malonate, and ethyl potassium malonate and ternary {[C₆mim][Cl] + methyl potassium malonate} and {[C₆mim][Cl] + ethyl potassium malonate} aqueous solutions were obtained through the isopiestic method at T = 298.15 K. These results reveal that the ionic liquid behaves as surfactant-like and aggregates in aqueous solutions at molality about 0.4 mol · kg⁻¹. The constant water activity lines of all the ternary systems investigated show small negative deviations from the linear isopiestic relation (Zdanovskii–Stokes–Robinson rule) derived using the semi-ideal hydration model. The density and speed of sound measurements were carried out on solutions of methyl potassium malonate and ethyl potassium malonate in water and of [C₆mim][Cl] in aqueous solutions of 0.25 mol · kg⁻¹ methyl potassium malonate and ethyl potassium malonate at T = (288.15 to 308.15) K at atmospheric pressure. From the experimental density and speed of sound data, the values of the apparent molar volume, apparent molar isentropic compressibility and excess molar volume were evaluated and from which the infinite dilution apparent molar volume and infinite dilution apparent molar isentropic compressibility were calculated at each temperature. Although, there are no clear differences between the values of the apparent molar volume of [C₆mim][Cl] in pure water and in methyl potassium malonate or ethyl potassium malonate aqueous solutions, however, the results show a positive transfer isentropic compressibility of [C₆mim][Cl] from pure water to the methyl potassium malonate or ethyl potassium malonate aqueous solutions. The results have been interpreted in terms of the solute–water and solute–solute interactions.     

Ternary (liquid + liquid) equilibria of {trifluorotris(perfluoroethyl)phosphate based ionic liquids + thiophene + heptane}

Ternary (liquid + liquid) equilibria for three systems containing ionic liquids {(4-(2-methoxyethyl)-4-methylmorpholinium trifluorotris(perfluoroethyl)phosphate, 1-(2-methoxyethyl)-1-methylpiperidinium trifluorotris(perfluoroethyl)phosphate, 1-(2-methoxyethyl)-1-methylpyrrolidinium trifluorotris(perfluoroethyl)phosphate) + thiophene + heptane} have been determined at T = 298.15 K. All systems showed high solubility of thiophene in the ionic liquid and low solubility of heptane. The solute distribution coefficient and the selectivity were calculated for all systems. High values of selectivity were obtained. The experimental results have been correlated using NRTL model. The influence of ionic liquid structure on phase equilibria is discussed.     

(Liquid + liquid) equilibria for ternary mixtures of (alkane + benzene + [EMpy] [ESO4]) at several temperatures and atmospheric pressure

In this work, the separation of benzene from aliphatic hydrocarbons (hexane, or heptane) is investigated by extraction with 1-ethyl-3-methylpyridinium ethylsulphate ionic liquid, [EMpy][ESO₄]. (Liquid + liquid) equilibria (LLE) data are determined for the ternary systems: {hexane (1) + benzene (2) + [EMpy][ESO₄] (3)} at T = (283.15, 293.15, 298.15, and 303.15) K and {heptane (1) + benzene (2) + [EMpy][ESO₄] (3)} at T = (283.15 and 298.15) K and atmospheric pressure. The selectivity and distribution coefficient, derived from the tie line data, were used to determine whether the ionic liquid is a good solvent for the extraction of aromatic from aliphatic compounds. The consistency of the tie line data was ascertained by applying the Othmer–Tobias and Hand equations. The experimental results for the ternary systems were well correlated with the NRTL equation. A study of the temperature effect and the influence of the chain length of the alkanes were realized. The results obtained were compared with other ionic liquids. There are no literature data for the mixtures discussed in this paper.     

Effect of tri-potassium phosphate on volumetric,acoustic, and transport behaviour of aqueous solutions of 1-ethyl-3-methylimidazolium bromide at T = (298.15 to 318.15) K

Density, sound velocity, and viscosity of 1-ethyl-3-methylimidazolium bromide, [Emim][Br], in aqueous solutions of tri-potassium phosphate with salt weight fractions (w_s = 0.00, 0.10, 0.15, and 0.20) have been measured as a function of concentration of [Emim][Br] at atmospheric pressure and T = (298.15, 303.15, 308.15, 313.15, and 318.15) K. The apparent molar volume, isentropic compressibility, apparent isentropic compressibility, and relative viscosity values have been evaluated from the experimental data. The partial molar volume and isentropic compressibility at infinite dilution, and viscosity B-coefficient obtained from these data have been used to calculate the corresponding transfer parameters for the studied IL from water to the aqueous tri-potassium phosphate solutions. Also, an empirical equation was satisfactorily used to correlate the experimental viscosity data.     

Binary and ternary (liquid + liquid) equilibrium for {methylcyclohexane (1) + toluene (2) + 1-hexyl-3-methylimidazolium tetracyanoborate (3)/1-butyl-3-methylimidazolium tetracyanoborate (3)}

This paper focuses on the study of the solubility behaviour of 1-hexyl-3-methylimidazolium tetracyanoborate [HMIM][TCB] and 1-butyl-3-methylimidazolium tetracyanoborate [BMIM][TCB] in combination with methylcyclohexane and toluene as representatives for non-aromatic and aromatic components. Binary and ternary (liquid + liquid) equilibrium data were collected at three different temperatures and at atmospheric pressure (0.1 MPa). The experimental data were well-correlated with the NRTL and UNIQUAC thermodynamic models; however, the UNIQUAC model gave better predictions than the NRTL, with a root mean square error below 0.97%. The non-aromatic/aromatic selectivities of the ionic liquids make them suitable solvents to be used in extractive distillation processes.     

Boiling temperature measurement for water,methanol, ethanol and their binary mixtures in the presence of a hydrochloric or acetic salt of mono-, di- or tri-ethanolamine at 101.3 kPa

The boiling temperature at atmospheric pressure were measured for 12 binary systems within the range T = (316 to 379) K and 7 ternary systems using a dual circulation. The systems studied contained water, methanol or ethanol with the following ionic liquids (ILs): monoethanolammonium acetate ([HEMA][Ac]), diethanolammonium acetate ([HDEA][Ac]), triethanolammonium acetate ([HTEA][Ac]) and diethanolammonium chloride ([HDEA]Cl). The experimental VLE results of the IL-containing binary systems were correlated by NRTL equation, and the binary NRTL parameters were used for the prediction of VLE of ternary systems with average absolute deviation of 0.73 K in boiling temperature. The results indicate that [HDEA]Cl can be used as an efficient solvent for the extractive distillation of (ethanol + water) mixture due to its notable salting-out effect, which lower the vapour pressure of water, increase the volatility of ethanol and eliminate the azeotropic phenomenon of the (water + ethanol) mixture at definite IL concentration.     

Extraction of toluene from aliphatic compounds using an ionic liquid as solvent: Influence of the alkane on the (liquid + liquid) equilibrium

In this paper, the feasibility of using 1-ethyl-3-methylimidazolium ethylsulfate ionic liquid, [EMim][ESO₄], as solvent for the extraction of toluene from aliphatic compounds (hexane, heptane, octane, or nonane) was analyzed. (Liquid + liquid) equilibrium (LLE) data for the ternary systems {alkane (1) + toluene (2) + [EMim][ESO₄] (3)} were measured at T = 298.15 K and atmospheric pressure. Selectivity and solute distribution ratio were calculated from the experimental LLE data, and the obtained values were compared to those previously reported using other ionic liquids and sulfolane. The degree of consistency of the experimental LLE data was ascertained using the Othmer–Tobias equation. Finally, the experimental LLE data were satisfactorily correlated with NRTL and UNIQUAC models.     

Phase equilibria study of {N-butylquinolinium bis{(trifluoromethyl)sulfonyl}imide + aromatic hydrocarbons,or an alcohol} binary systems

Quinolinium ionic liquid has been prepared from 1-butylquinolinium bromide as a substrate. The work includes specific basic characterization of synthesized compound by NMR spectra, elementary analysis and water content. The basic thermal properties of the pure IL, i.e. melting and glass-transition temperatures, as well as the enthalpy of fusion have been measured using a differential scanning microcalorimetry technique (DSC). (Solid + liquid) phase equilibria (SLE) and (liquid + liquid) phase equilibria (LLE) for the binary systems: ionic liquid (IL) N-butylquinolinium bis{(trifluoromethyl)sulfonyl}imide, {([BQuin][NTf₂]) + aromatic hydrocarbon (benzene, or toluene, or methylbenzene, or propylbenzene, or thiophene), or an alcohol (ethanol, or 1-butanol, or 1-hexanol, or 1-octanol, or 1-dodecanol)} have been determined at ambient pressure. A dynamic method was used over a broad range of mole fractions and temperatures from (260 to 330) K. For the binary systems, the simple eutectic diagrams were observed with immiscibility in the liquid phase with an upper critical solution temperature (UCST). For mixtures with alcohols, it was observed that with increasing chain length of an alcohol the solubility decreases and the UCST increases. In the case of mixture (IL + benzene, or alkylbenzene, or thiophene) the eutectic systems with mutual immiscibility in the liquid phase with very high UCSTs were observed. These points were not detectable with our method and they were observed at low ionic liquid mole fraction. Densities at high temperatures were determined and extrapolated to T = 298.15 K. Well-known UNIQUAC, and NRTL equations have been used to correlate experimental SLE data sets. For the systems containing immiscibility gaps {IL + an alcohol} parameters of the LLE correlation equation have been derived using only the NRTL equation.     

(Liquid + liquid) equilibria of (water + linalool + limonene) ternary system at T = (298.15, 308.15, and 318.15) K

(Liquid + liquid) equilibrium (LLE) data for {water (1) + linalool (2) + limonene (3)} ternary system at T = (298.15, 308.15, and 318.15 ± 0.05) K are reported. The organic chemicals were quantified by gas chromatography using a flame ionisation detector while water was quantified using a thermal conductivity detector. The effect of the temperature on (liquid + liquid) equilibrium is determined and discussed. Experimental data for the ternary mixture are compared with values calculated by the NRTL and UNIQUAC equations, and predicted by means of the UNIFAC group contribution method. It is found that the UNIQUAC and NRTL models provide a good correlation of the solubility curve at these three temperatures, while comparing the calculated values with the experimental ones, the best fit is obtained with the NRTL model. Finally, the UNIFAC model provides poor results, since it predicts a greater heterogeneous region than experimentally observed.     

Separation of toluene from cyclic hydrocarbons using 1-butyl-3-methylimidazolium methylsulfate ionic liquid at T = 298.15 K and atmospheric pressure

In this paper the extraction of toluene from cyclic hydrocarbons (cyclohexane, or methylcyclohexane, or cyclooctane, or cyclohexene) was analyzed by liquid extraction with 1-butyl-3-methylimidazolium methylsulfate ionic liquid, [BMim][MSO₄], as solvent. The experimental (liquid + liquid) equilibrium (LLE) data were determined at T = 298.15 K and atmospheric pressure. Solubility curves were obtained by the cloud point method and tie-line compositions were determined by density measurement. An analysis of the influence of different cyclic hydrocarbons on the extraction was performed.The effectiveness of the extraction of toluene from cyclic hydrocarbons was evaluated by means of the solute distribution ratio and selectivity values. The degree of consistency of the experimental LLE data was ascertained using the Othmer–Tobias and Hand equations. The experimental data for the (liquid + liquid) equilibria of the ternary systems were correlated with the Non-Random Two-Liquid (NRTL) and UNIversal QUAsi-Chemical (UNIQUAC) thermodynamic models.     

Solubility and thermodynamic function of a new anticancer drug ibrutinib in 2-(2-ethoxyethoxy)ethanol + water mixtures at different temperatures

Ibrutinib is a recently approved anticancer drug recommended for the treatment of mantle cell lymphoma and chronic lymphocytic leukemia. It has been reported as practically insoluble in water and hence it is available in the market at higher doses. Poor solubility of ibrutinib limits its development to oral solid dosage forms only. In this work, the solubilities of ibrutinib were measured in various 2-(2-ethoxyethoxy)ethanol (Carbitol) + water mixtures at T = (298.15 to 323.15) and p = 0.1 MPa. The solubility of ibrutinib was measured using an isothermal method. The thermodynamics function of ibrutinib was also studied. The measured solubilities of ibrutinib were correlated and fitted with Van’t Hoff, the modified Apelblat and Yalkowsky models. The results of curve fitting of all three models showed good correlation of experimental solubilities of ibrutinib with calculated ones. The mole fraction solubility of ibrutinib was observed highest in pure 2-(2-ethoxyethoxy)ethanol (2.67 · 10⁻² at T = 298.15 K) and lowest in pure water (1.43 · 10⁻⁷ at T = 298.15 K) at T = (298.15 to 323.15) K. Thermodynamics data of ibrutinib showed an endothermic, spontaneous and an entropy-driven dissolution behavior of ibrutinib in all 2-(2-ethoxyethoxy)ethanol + water mixtures. Based on these results, ibrutinib has been considered as practically insoluble in water and freely soluble in 2-(2-ethoxyethoxy)ethanol. Therefore, 2-(2-ethoxyethoxy)ethanol could be used as a physiologically compatible cosolvent for solubilization and stabilization of ibrutinib in an aqueous media. The solubility data of this work could be extremely useful in preformulation studies and formulation development of ibrutinib.     

Phase equilibria study of the binary systems (1-butyl-3-methylimidazolium tosylate ionic liquid + water,or organic solvent)

(Solid + liquid) phase equilibria (SLE) and (liquid + liquid) phase equilibria (LLE) for the binary systems: ionic liquid (IL) 1-butyl-3-methylimidazolim tosylate (p-toluenesulfonate) {[BMIM][TOS] + water, an alcohol (ethanol, or 1-butanol, or 1-hexanol, or 1-octanol, or 1-decanol), or n-hexane, or an aromatic hydrocarbons (benzene, or toluene, or ethylbenzene, or propylbenzene, or thiophene)} have been determined at ambient pressure. A dynamic method was used over a broad range of mole fractions and temperatures from (230 to 340) K. For the binary systems containing water, or an alcohol, simple eutectic diagrams were observed with complete miscibility in the liquid phase. As usual, with increasing chain length of the alcohol the solubility decreases. In the case of mixtures {IL + n-hexane, or benzene, or alkylbenzene, or thiophene} the eutectic systems with mutual immiscibility in the liquid phase with an upper critical solution temperature (UCST) were detected. The basic thermal properties of the pure IL, i.e. melting and glass-transition temperatures, as well as the enthalpy of fusion have been measured using a differential scanning microcalorimetry technique (DSC). Density at high temperatures was determined and extrapolated to 298.15 K. Well-known UNIQUAC, Wilson and NRTL equations have been used to correlate experimental SLE data sets for alcohols and water. For the systems containing immiscibility gaps {IL + n-hexane, or benzene, or alkylbenzene, or thiophene}, parameters of the LLE correlation equation have been derived using only the NRTL equation.     

(Solid + liquid) equilibria predictions of ionic liquid containing systems using COSMO-RS

(Solid + liquid) equilibria (SLE) prediction are an important phase equilibria property for ionic liquid (IL) mixtures especially when the IL exists as a solid. In this work, the SLE for the binary systems of (IL + thiophene) consisting of the ILs: n-butyl-4-methylpyridinium tosylate [BM₄Py][TOS], n-butyl-3-methylpyridinium tosylate [BM₃Py][TOS], n-hexyl-3-methylpyridinium tosylate [HM₃Py][TOS], and 1,4-dimethylpyridinium tosylate [M_1,4Py][TOS] are predicted using the quantum chemical based COSMO-RS (COnductor like Screening MOdel for Real Solvents) model. Initially, benchmarking studies are performed on binary mixtures which are known beforehand. The values of the predicted solubility are then compared with the experimental results by calculating the root mean square error (RMSE). The SLE predictions of the solubility of pyrene and dibenzothiophene in five different solvents were carried out giving an average RMSE of 4%. Further the applicability of COSMO-RS to binary systems consisting of (ionic liquid + alcohol) mixtures and (ionic liquid + hydrocarbons) are predicted. The ionic liquids concerned are n-butyl-3-methylpyridinium tosylate [BM₃Py][TOS] while the alcohols and hydrocarbons are 1-butanol, 1-hexanol, 1-octanol, 1-decanol, and benzene, toluene, ethylbenzene, n-propylbenzene respectively. The experimental data for the ionic liquid [BM₄Py][TOS] with thiophene gave the smallest deviation of 10.2%. The overall RMSE for IL–thiophene, IL–alcohol, and IL–hydrocarbons were 15%, 17.2% and 12.9% respectively. Thus the predicted solubility values were found to be in reasonable agreement with the experimental values.     

Thermodynamic studies of the ionic liquid 1-hexyl-3-methylimidazolium chloride [C6mim][Cl] in polyethylene glycol aqueous solutions

Vapour pressure osmometery (VPO) measurements at T = 308.15 K for {[C₆mim][Cl] + water}, {[C₆mim][Cl] + (0.005, 0.0155, and 0.0263) mol · kg⁻¹ PEG2000 + water} and {[C₆mim][Cl] + (0.0017, 0.0052, and 0.0088) mol · kg⁻¹ PEG6000 + water} systems and isopiestic measurements at T = 298.15 K for {[C₆mim][Cl] + PEG2000 + water} and {[C₆mim][Cl] + PEG6000 + water} systems have been carried out. The VPO measurements were carried out at very low concentrations of PEG and from which the values of the water activities, osmotic coefficients, vapour pressure and activity coefficients were obtained. The data obtained from the VPO method show that over the whole concentration range of the ionic liquid (IL), the activity coefficients of [C₆mim][Cl] in the presence of PEG2000 are increased. Although, at high IL concentrations, the values of the activity coefficient of [C₆mim][Cl] in the presence of PEG6000 are also increased, however for low concentrations of IL the values of the activity coefficient of [C₆mim][Cl] in pure water are larger than those in aqueous PEG6000 solutions. For a known IL concentration, the values of water activity coefficient for the binary {[C₆mim][Cl] + water} system are larger than those for the ternary {[C₆mim][Cl] + PEG + water} systems and decrease by increasing the concentration of PEG or decreasing the molar mass of PEG. The constant water activity lines of the all ternary systems obtained from the isopiestic method show positive deviation from the linear isopiestic relation (Zdanovskii–Stokes–Robinson rule) derived using the semi-ideal hydration model. The results have been interpreted in terms of the solute–water and solute–solute interactions.     

(Liquid + liquid) equilibrium data for the ternary systems (cycloalkane + ethylbenzene + 1-ethyl-3-methylimidazolim ethylsulfate) at T = 298.15 K and atmospheric pressure

In this paper, (liquid + liquid) equilibrium (LLE) data for the ternary systems (cyclohexane, or cyclooctane, or methylcyclohexane + ethylbenzene + 1-ethyl-3-methylimidazolium ethylsulfate) have been determined experimentally at T = 298.15 K and atmospheric pressure. The solubility curves and the tie-line compositions of the conjugate phases were obtained by means of density. The degree of consistency of the tie-lines was tested using the Othmer–Tobias equation, and the Non-Random Two-Liquid (NRTL) and the Universal Quasi-Chemical (UNIQUAC) models were used to correlate the phase equilibrium in the systems. Selectivity and solute distribution ratio were evaluated for the immiscible region.     

Solubilities and liquid–liquid equilibria of (water + ethanol + α,α,α-trifluorotoluene) at temperatures T = (288.15, 298.15, and 308.15) K and pressure p = 101.2 kPa

New solubility and liquid–liquid equilibrium (LLE) data of solutions of (water + ethanol + α,α,α-trifluorotoluene) are determined at three temperatures (288.15, 298.15, and 308.15) K and atmospheric pressure. The solubility and LLE data are correlated quantitatively by empirical equations, NRTL, and UNIQUAC models. The effect of temperature upon miscibility of the ternary systems is small. Practically, α,α,α-trifluorotoluene is capable to extract efficiently ethanol from its dilute aqueous solutions to obtain absolute alcohol.