화학공학소재연구정보센터
Industrial & Engineering Chemistry Research, Vol.37, No.5, 2039-2044, 1998
Salting effect on the liquid-liquid equilibria for the partially miscible systems of n-propanol-water and i-propanol-water
The liquid-liquid equilibria (LLE) data were experimentally measured for the partially miscible systems of n-propanol-water-NaCl, n-propanol-water-NaBr, n-propanol-water-KCl, and i-propanol-water-NaCl at 25 degrees C. A method of calculation for the prediction of the salting effect on the LLE of organic aqueous solutions was proposed to correlate the experimental tie-line data. In the proposed method, the activity coefficients of the solvents were calculated by Tan's modified Wilson model which was combined with a vapor pressure model of electrolyte solutions, and the mean ionic activity coefficient was calculated by the Gibbs-Duhem equation. The parameters required by the proposed method could be estimated by the vapor pressures of a water-salt system and the alcohol-water interaction parameters in the liquid-phase activity coefficient model. No ternary parameter was required. The proposed method has been used to predict the LLE data measured by this work, and the overall average deviation of tie-line compositions was 0.018.