Prediction of liquid-liquid equilibria for PEG 2000-sodium citrate based aqueous two-phase systems

Liquid-liquid equilibrium (LLE) data were obtained for the polyethylene glycol 2000-sodium citrate-water system at 298.15, 308.15 and 318.15 K. Experimental and analytical methods were described in the previous article [T. Murugesan, M. Perumalsamy, J. Chem. Eng. Data 50 (2005) 1392]. The UNIQUAC, NRTL, UNIFAC and ASOG models have been used to fit the experimental LLE data. The interaction parameters of the models were estimated. The Debye-Huckel equation was used to calculate the long-range electrostatic interaction of the ions. The predicted LLE data by the models show good agreement with the experimental data. (c) 2006 Elsevier B.V. All rights reserved.