Liquid–Liquid Equilibrium Data of 2‑Propanol + Sodium Sulfate/Nitrate/Acetate + Water Systems

• Published in: Journal of chemical and engineering data 2020-04, Vol.65 (4), p.1369-1378
• Main Authors: Souza, Pedro P. A, Julião, Igor B, Mendes, Marisa F
• Format: Article
• Language: English
• ISSN: 0021-9568; 1520-5134
• DOI: 10.1021/acs.jced.9b00537

In this study, ternary liquid–liquid equilibrium of systems composed of 2-propanol, sodium salts, and water as 2-propanol + sulfate/nitrate/sodium acetate + water were successfully measured at 298.15 K and 101.3 kPa. The cloud-point method was used to determine the binodal curve of aqueous two-phase systems, formed by 2-propanol and an inorganic salt. According to this technique, it was found that the use of initial saline solutions at a maximum concentration provided more reliable results than with a salt solution with a minimum concentration. The binodal points obtained experimentally were adjusted by Mistry or Merchuk models. The Othmer–Tobias and Bancroft equations were used to evaluate that the tie line data were reliable. The strength of the salting-out effect of the different salts was evaluated by the effective excluded volume theory and the Setschenow-type equation. The Othmer–Tobias equation exhibited excellent results for sulfate systems, while the Setschenow-type equation showed the best values for nitrate and acetate. It was found that for 2-propanol + sodium salts + water systems, the power of the saline effect of the anions investigated followed the order of sulfate > nitrate > acetate. Two water-rich phases were observed in the sulfate systems, in spite of the nitrate and acetate systems, which had an extremely alcoholic phase and a salt-rich and a water-rich phase.