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The experimental liquid – liquid equilibrium (LLE) data for three ternary mixtures containing an ionic liquid (IL) (1-butyl-3-methyl imidazolium thiocyanate [Bmim][SCN]), alkanes ( n -hexane, n -octane and n -decane) and sulfur compound (thiophene) have been measured experimentally. Distribution and selectivity coefficients have been calculated using experimental data. The LLE data have been obtained at 25 °C and ambient pressure. The experimental LLE data of ternary mixtures have been compared with our previous works. It has been shown that the IL with higher molecular weight of cation has higher solute distribution and lower selectivity coefficients. It has been found that the solubility decreases as the cation length decreases, meanwhile ILs cation chain length has a remarkable effect on solubility of alkanes. Moreover, the experimental data have been demonstrated that the selectivity decreases as alkane chain length of alkane decreases while the solubility of alkanes in the ILs increases, hence the removal costs of aromatic sulfur components will be increased. The results show that [Bmim][SCN] has the lowest alkane solubility and highest selectivity coefficient, in the system containing n -decane and thiophene. A comparative study reveals that compared to other ILs, [Bmim][SCN] is a more suitable solvent. Finally, the experimental data have been correlated utilizing non-randomness two liquid (NRTL) model. The binary energy parameters were obtained, it can be seen that the model can correlate the experimental data efficiently. [ABSTRACT FROM AUTHOR]

In this study, liquid–liquid equilibrium measurements were performed for the ternary (water/non-ionic surfactant/decane) systems at T = 298.15 K and atmospheric pressure. Propylene glycol mono propyl ether and ethylene glycol monobutyl ether were selected as surfactant; the first one is propylene glycol ether, while the second one is ethylene glycol ether. New experimental liquid–liquid equilibrium data were presented for the corresponding systems. Effect of salinity and surfactant structure (EO or PO functional group) on the phase behavior of such systems has been studied by both experimental measurements and thermodynamic modeling. The experimental phase behavior data were predicted by the perturbed hard sphere chain (PHSC) equation of state. In the presence of electrolyte, mean spherical approximation (MSA) term has been coupled with the PHSC EoS to account the contribution of long-range interactions. The calculated results indicate acceptable qualitative agreement of PHSC results with the experimental data. [ABSTRACT FROM AUTHOR]

Ionic Liquids (IL's) are now considered as useful alternative solvent for the desulfurization of gasoline and diesel oils by liquid–liquid extraction. In this work, 1-hexyl-3-methylimidazolium thiocyanate([Hmim][SCN]) and 1-octyl-3-methylimidazolium thiocyanate([Omim][SCN]) as ionic liquids were investigated as model solvents for removal of thiophene from some aliphatic hydrocarbons ( n -hexane, n -octane and n -decane) as fuel model. Liquid–liquid phase equilibrium data were measured for ternary systems containing one ionic liquid as solvent, thiophene as sulfur component and one aliphatic hydrocarbon as fuel model at 298.15 K under ambient pressure. It was found that the IL with lower molecular weight of cation has higher selectivity but lower solute distribution coefficients. Besides, the experimental data demonstrates that the selectivity increases as alkane chain length of fuel model increases while the solubility of ionic liquids decreases, hence the costs of desulfurization process will be decreased. Our results show that for the case of [Hmim][SCN](1) + n -decane(2) + thiophene(3) the highest selectivity and lowest alkane solubility were obtained. In other words [Hmim][SCN] is a more suitable solvent than [Omim][SCN] for desulfurization of higher alkane. Finally in order to find the model parameters, the nonrandom two liquid (NRTL) was used to correlate the experimental data. The results show the model can successfully correlate the experimental data. [ABSTRACT FROM AUTHOR]

In this study, vapor-liquid and liquid-liquid equilibrium in mixtures containing glycol ether surfactant, non-polar and polar compounds are calculated using Perturbed Hard Sphere Chain (PHSC) equation of state (EoS). Pure liquid density and vapor pressure of surfactants are used for parameter estimation of glycol ether surfactants. The PHSC parameters are calculated for both ethylene glycol ether and propylene glycol ether surfactants. Glycol ether surfactant molecules are modeled as associating components by considering two association sites for each molecule. The results show that the PHSC model is capable of correlating thermodynamic behavior of binary (polar + surfactant) and (non-polar + surfactant) systems. Upper critical solution temperature (UCST) for hydrocarbon + surfactant and lower critical solution temperature (LCST) for water + surfactant systems are accurately calculated. The critical temperatures and the extent of immiscibility are in good agreement with the available experimental data. [ABSTRACT FROM AUTHOR]

Abstract: In this work, the capability of the Perturbed Hard Sphere Chain (PHSC) equation of state (EOS) in liquid–liquid equilibrium calculations of salt–polyethylene glycol (PEG)–water systems is investigated. In order to present a comprehensive model, association as well as electrostatic contributions have been added to the original PHSC EOS. In this work 47 systems including PEG (with different molecular weights) and various salts have been modeled at different temperatures. Only two adjustable parameters between salt and PEG and between water and PEG have been employed. Good agreement between experimental data and calculation results is observed. Overall average deviation for all of the systems considered is 6.81%. This study shows that the PHSC EOS can be employed for correlation of phase behavior in aqueous two phase systems. [Copyright &y& Elsevier]

Abstract: In this work, the phase behavior of mixed solvent electrolyte systems containing 1-butanol+water+ammonium chloride at temperatures of 298.15, 308.15 and 318.15K and at atmospheric pressure have been studied experimentally and theoretically. For the studied systems, liquid–liquid equilibrium has been observed throughout the studied temperature range. Ammonium chloride shows a salting out effect in the two phase region, while temperature has a minor effect on the liquid–liquid equilibria in the studied temperature range. The measured experimental data have been modeled using a modified version of the extended UNIQUAC model. The model has been found to give a satisfactory description of LLE data obtained in this work, with an average absolute deviation of less than 1.5% in calculated mass fractions compared to experimental data. [Copyright &y& Elsevier]

Abstract: In this work liquid–liquid equilibria (LLE) in the system containing 1-butanol–water–sodium nitrate at temperatures of 25 and 35°C has been investigated experimentally and theoretically. The extended UNIQUAC model has previously been used for correlation of liquid–liquid equilibrium in aqueous salt systems containing alcohols. In that model the excess Gibbs energy consists of two terms, the original UNIQUAC term and Debye–Hückel term which considers the alcohol as a non-electrolyte solute. In this work, a modified extended UNIQUAC model is used by taking into account mixed solvent theories. The model consists of three terms, the original UNIQUAC term, a Pitzer–Debye–Hückel term and a Born term. The model has been found to give a satisfactory description of LLE data obtained in this work, with an average absolute deviation of less than 0.5 in calculated mass percent compared to experimental data. [ABSTRACT FROM AUTHOR]

Abstract: Experimental measurements have been performed for liquid–liquid equilibria in aqueous systems containing 1-pentanol and sodium nitrate at temperatures of 298.15 and 308.15K and at atmospheric pressure. The results have been modeled using the extended UNIQUAC model and also a modified version of this model. Relevant model parameters have been adjusted using the experimental data. Both models are capable of correlating the experimental data with an average deviation of less than 0.8 weight percent, with the modified model producing slightly better results. The predictive nature of the models has also been verified. [Copyright &y& Elsevier]