Aqueous Salt Solutions


Liquid-Liquid-Equilibrium in the iso-propanol - Na2SO4 - H2O system

Liquid-liquid equilibrium in the iso-propanol - sodium sulfate - water system at 35°C

Water and iso-propanol are miscible in all proportions. A miscibility split can be caused by a number of salts. One of them is sodium sulfate. The phase diagram below shows experimental data for liquid-liquid equilibrium in the isopropanol - Na2SO4 - H2O system at 35°C. The experimental data were measured by Lynn et al. (ref. 1). The phase diagram shows the binodal curve calculated with the Extended UNIQUAC model together with the experimental data.

The model parameters used for the calculation are those from Thomsen et al. (ref. 2). The calculation was performed with the multi-phase flash (VLLSE) routine developed by Aqueous Solutions Aps and implemented in a DLL callable from Microsoft Excel.

  1. Lynn, S., Schiozer, A. L., Jaecksch, W. L., Cos, R., Prausnitz, J. M., "Recovery of anhydrous Na2SO4 from SO2-scrubbing liquor by extractive crystallization: liquid-liquid equilibria for Aqueous Solutions of Sodium Carbonate, Sulfate, and/or Sulfite Plus Acetone, 2-Propanol, or tert-Butyl Alcohol", Ind. Eng. Chem. Res., 35(1996)4236-4245, DOI:10.1021/ie960094e.
  2. Thomsen, Kaj;  Iliuta, Maria; and Rasmussen, Peter, "Extended UNIQUAC model for correlation and prediction of vapor-liquid-liquid-solid equilibria in aqueous salt systems containing non-electrolytes. Part B. Alcohol (Ethanol, Propanols, Butanols) - water - salt systems". (Chemical Engineering Science 59(2004)3631-3647, issue 17), DOI:10.1016/j.ces.2004.05.024.