(Liquid + liquid) equilibrium of (NaNO3 + PEG 4000 + H2O) ternary system at different temperatures

Highlights: → LLE data for the ATPS NaNO3 + PEG 4000 were determined at T = (288.15 and 308.15) K. → The experimental data shown that the temperature increases as STL and biphasic area increase. → The Chen-NRTL, modified Wilson and UNIQUAC models were used to correlate the experimental tie-line data. → The results show that the quality of fitting is better with the UNIQUAC model. - Abstract: Phase diagram and (liquid + liquid) equilibrium (LLE) data for the (NaNO3 + polyethylene glycol 4000 (PEG 4000) + H2O) system have been determined experimentally at T = (288.15 and 308.15) K. The effects of temperature on the binodal curves and tie-lines have been studied and it was found that an increasing in temperature caused the expansion of two-phase region. The Chen-NRTL, modified Wilson and UNIQUAC models were used to correlate the experimental tie-line data. The results show that the quality of fitting is better with the UNIQUAC model.