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A detailed test of the group-contribution hole models is used to predict thermodynamic properties of pure n-alkanes aliphatic monoethanes, 1-Chloroalkanes and their mixtures with n-alkane. The model however, in spite of being universal is applicable only to a few properties and limited range of parameters.

• Trivial and non-physical solutions of the binary LLE were discussed. • The Equal Area Rule approach in its modified form avoids some difficulties. • The NRTL parameter ranges leading to various types of the LLE were determined. • The shape of the objective function to fit the parameters may cause some problems. Model calculations of the liquid-liquid equilibria encounter several considerable serious difficulties due to the relatively complicated requirements that must be met in the equilibrium state. These requirements can prevent a solution from being obtained or lead to false solutions. In this paper, we investigate the possibility that the numerical procedure aimed at looking for concentrations of coexisting phases in an isothermal binary system will fall into a trivial solution or end up with a solution lacking the physical sense. The model system is generated on the basis of the NRTL equation. We propose the modified Equal Area Rule (EAR) algorithm to overcome some of these difficulties. The advantages of the EAR over the traditional approach are shown and discussed for binary systems. Using this method, we determined a range of the NRTL parameters leading to different kinds of immiscibility regions in the liquid-liquid equilibrium (LLE). The shape of the objective function during the fitting of the NRTL parameters to the LLE experimental data was determined and discussed. This has a potentially strong impact on the convergence of the optimization algorithm. [Display omitted] [ABSTRACT FROM AUTHOR]

Highlights: [•] New apparatus measuring liquid–liquid and solid–liquid-equilibria was constructed. [•] LLE data for isomeric C8 aliphatic ethers and nitromethane were measured. [•] Influence of the position of ether group on the solubility curve was discussed. [ABSTRACT FROM AUTHOR]

Densities of pure 1-butyl-3-methylimidazolium methylsulfate, [Cmim][MeSO], and its mixtures with methanol have been measured. Measurements were made with an accuracy of ±0.2 kg·m, using a vibrating-tube densimeter, over the temperature and pressure ranges (283.15-333.15) K and (0.1-35) MPa, respectively. The experimental densities for the pure ionic liquid and alcohol have been correlated by the Tait equation. The results for the { x[Cmim][MeSO] + (1 − x)MeOH} system have been correlated by a van Laar equation involving parameters that are dependent on temperature and pressure. Excess volumes have been obtained directly from the experimental densities, while isobaric expansivities, isothermal compressibilities, and related excess properties were calculated from the correlation equation. Exceptionally strong pressure and temperature influences on these properties were observed. [ABSTRACT FROM AUTHOR]

Abstract: Densities of pure ionic liquids, 1-hexyl-3-methylimidazolium methylsulfate [C6mim][MeSO4], 1-hexyl-3-methylimidazolium ethylsulfate, [C6mim][EtSO4], 1-butyl-3-methylimidazolium ethylsulfate [C4mim][EtSO4] and their mixtures with either methanol or ethanol, were measured at temperatures T/K=(283.15, 298.15, 313.15, 328.15) at ambient pressure. The excess volumes V E were correlated by the van Laar equation with the temperature-dependent parameters. Isobaric expansivity and excess isobaric expansivity were described as functions of temperature and composition. The negative deviations from ideal mixing were observed for excess volume V E and the excess isobaric expansivity α E. [Copyright &y& Elsevier]

Abstract: Pressure–density–temperature measurements of the following pure ionic liquids—1-butyl-3-methylimidazolium tetrafluoroborate, [C4mim][BF4], 1-butyl-3-methylimidazolium methylsulfate [C4mim][MeSO4] and 1-ethyl-3-methylimidazolium ethylsulfate [C2mim][EtSO4] were performed using a vibrating tube densimeter over the temperature range (283.15 to 353.15)K and the pressure range (0.1 to 35)MPa. Experimental densities have been correlated by the Tait equation with the temperature dependent parameters. The isobaric expansivity and isothermal compressibility have been calculated. The influence of the cation alkyl chain length and the character of anion on the measured properties were discussed. [Copyright &y& Elsevier]

• Over 2500 ternary systems were checked in terms of liquid–liquid equilibria appearing. • Salt/carbohydrate induced phase split in more than 300 nonaqueous systems. • Phase split inducing abilities of ions were matched with reversed Hofmeister series. More than 2500 ternary systems containing binary nonaqueous solvents and a salt or carbohydrate were checked experimentally under ambient conditions to demonstrate the liquid–liquid phase split. The binary solvents consisted of one strongly polar component and another significantly less polar. Phase separation has been observed in more than 300 systems. These systems are direct analogues of the aqueous two-phase systems (ATPS) that have been extensively studied and found numerous applications. The obtained data were analyzed and some correlations were observed. Possibilities of creating the liquid–liquid miscibility gap depending on the solvents' polarity and the solute properties were discussed. This phenomenon most often occurs with binary solvents containing a strongly polar component, such as formamide, dimethyl sulfoxide, ethane-1,2-diol, or N -methylformamide. Carbohydrates have been found to be better liquid–liquid phase split inducers than salts. Among the latter, calcium and lithium chlorides, and sodium iodide turned out to be the most effective. A strict correspondence of the decreasing probability of creating a miscibility gap by different ions with the reversed Hofmeister series was confirmed. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract: Solid–liquid, liquid–liquid and vapour–liquid equilibrium measurements for binary and ternary systems containing building blocks of biomass origin such as propionic acid, lactic acid and alternative solvents like carbon dioxide and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ionic liquid have been carried out at 313.15K. The binary solid–liquid and liquid–liquid equilibrium measurements were performed at ambient pressure. The vapour–liquid equilibrium was studied in the range of pressure from 3.54 to 12MPa while ternary systems were examined at 9, 10 and 12MPa. The samples from the coexisting phases were taken and the compositions of both liquid and vapour phases were determined experimentally. The three-phase system was observed for lactic acid+ionic liquid+CO2 as well. The achieved results were correlated using the Peng–Robinson equation of state with the Mathias–Klotz–Prausnitz mixing rule. The set of interaction parameters for the employed equations of state and the mixing rule for the investigated systems were obtained. [Copyright &y& Elsevier]

Abstract: Vapour–liquid equilibrium measurements for binary and ternary systems containing carbon dioxide, 1-propanol, and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide or 1-decyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide or 1-ethyl-3-methylimidazolium trifluoromethanesulfonate ionic liquids are presented in this work. The binary CO2 +1-decyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide system at 313.15K at pressure range from 2 to 14.4MPa was examined. The obtained phase envelop shows that even at low pressure of CO2 the solubility of the gas in the ionic liquid is high. The ternary phase equilibria were studied at 313.15K and pressures in the range from 9 to 12MPa. The ternary phase diagrams show that higher CO2 pressure diminishes the miscibility gap. The experimental samples from the coexisting phases were taken and compositions of both liquid and vapour phases were determined experimentally. The results were correlated using the Peng–Robinson and the Soave–Redlich–Kwong equations of state with the Mathias–Klotz–Prausnitz mixing rule. The set of interaction parameters for the employed equations of state and the mixing rule for the investigated systems were obtained. [Copyright &y& Elsevier]