Temperature Effect on the Liquid–Liquid Equilibrium of Isopropanol + Trisodium Citrate + Water Aqueous Two-Phase Systems at T = 288.15, 298.15, 308.15, and 318.15 K

Abstract

In this study, the temperature effect on the aqueous two-phase systems composed of isopropanol + trisodium citrate + water was studied by experimental measurement of the binodal curves and tie-line compositions at T = 288.15, 298.15, 308.15, and 318.15 K temperatures. It was found that the salting-out ability of the system was increased with increasing the temperature so that the extension of the two-phase area, especially in the salt-rich region, was increased by raising the temperature. Correlation of the tie-line compositions to a Seteschenow-type equation also showed that the two-phase formation tendency of the studied systems has a positive correlation with the salting-out parameters, K ca , of this equation so that K ca values were increased with increasing the temperature. Binodal curves at all studied temperatures were successfully fitted to two temperature-dependent equations with only three fitting parameters, simultaneously. Also, the electrolyte-Wilson model was modified as a function of temperature and used for simultaneous correlation of the tie-line data at all studied temperatures. An excellent agreement between the calculated values of the modified electrolyte-Wilson model and the experimental results was obtained.

Temperature Effect on the Phase Equilibrium of Polyethylene Glycol 2000 + Trilithium Citrate + Water Aqueous Two-Phase Systems at T = 288.15, 298.15, 308.15, and 318.15 K

“…The local composition approximation of the excess Gibbs energy ( G ex ) was implemented by Zafarani-Moattar and Sadeghi − to extend the NRTL and Wilson models for the case of polymer + electrolyte + water systems. The e-Wilson model has also been used recently by our group to model the tie-lines of the isopropanol + trisodium citrate + water ATPS at different temperatures . In both m-NRTL and e-Wilson models, G ex is based on the contribution of three terms, that is, in which G ex, Comb is the combinatorial contribution obtained from the changes in the mixing entropy of particles of different size, G ex, LR is the long-range interaction contribution, mainly due to the electrostatic interactions of ionic species, and G ex, SR is the short-range contribution of nonelectrolyte species.…”

“…ρ is a parameter to account for the size of the ions in hard-core approximation. The constant value of ρ = 14.9 was used in this study, following our previous work Table .…”

“…Aqueous two-phase systems (ATPSs) have potential applications in the extraction, purification, and separation of different biological and chemical products and therefore have attracted the attention of the biochemical industry. Various types of ATPSs have been studied in research articles, such as polymer + inorganic salt + water, polymer + polymer + water, polymer + organic salt (i.e., ionic liquid) + water, and alcohol + salt + water . ATPSs of polymer + polymer + water are expensive and viscose; therefore, they were not applied extensively in industrial scales, while the polymer + salt + water systems have a number of advantages such as their selection in density, affordability, adaptability, and selective separation ability of chemicals and biological substances .…”

Effect of Temperature on the Phase Equilibria of Poly(vinylpyrrolidone) 10000 + Trilithium Citrate + Water Aqueous Two-Phase System and Partitioning of Curcumin at T = 298.15, 308.15, and 318.15 K

“…Citrate salts are watersoluble and can be an alternative to nontoxic and inflammable salts to form environmentally friendly ATPSs. 10,15,35 Various thermodynamic or empirical models are used to model the liquid−liquid equilibrium (LLE) of various ATPSs. Binodal models of the polymer/alcohol + electrolyte ATPSs are simple nonlinear empirical equations, in which the fitting function represents the concentration of one component (i.e., polymer/alcohols or electrolyte) as a function of the other one.…”

Experiment and Correlation of Liquid–Liquid Equilibrium Data for Water + 2-Propanol + 1-Octanol or n-Propyl Acetate at 298.2, 308.2, and 318.2 K under 101.3 kPa

“…There are few studies on alcohols as extractants, and this work also studies the liquid–liquid behavior of water + IPA + 1-octanol. However, the current research − on the LLE data of IPA and water systems at different temperatures is still insufficient. Therefore, it is urgent to obtain more reliable LLE data to realize industrial extraction and separation of IPA and water.…”