Extended NRTL model for PEG + salt based aqueous two-phase system

ABSTRACT: Liquid–liquid equilibrium (LLE) data of aqueous poly(ethylene glycol) (PEG) 2000–sodium citrate
systems were determined experimentally at 25◦, 35◦ and 45 ◦C. Experimental techniques and analytical methods were
described in the previous article (T. Murugesan, M. Perumalsamy. J. Chem. Eng. Data. 2005; 50, 1392–1395 [22]).
The NRTL (nonrandom, two-liquid) model, expressed in mass fraction, was used to correlate the LLE of aqueous twophase
systems (ATPS). The interaction energy parameters of the NRTL model were adjusted using these experimental
LLE data. The model described experimental equilibrium data with a good agreement.  2009 Curtin University of
Technology and John Wiley & Sons, Ltd.