VAPOR-LIQUID-EQUILIBRIUM FOR THE ACETONE METHANOL INORGANIC SALT SYSTEM

Isobaric VLE data were measured for the acetone-methanol binary system at 101.32 kPa and for the acetone-methanol-salt system at the same pr essure at different salt concentrations using a modified Othmer equili brium still. Both salts investigated in this work, KI and NaI, exhibit ed a salting-out effect on acetone. The experimental data for the salt -free system were correlated by Wilson, NRTL and UNIQUAC models. For t he salt systems, the experimental data were correlated by the electrol ytic NRTL model of Mock et al. [Mock, B., Evans, L.B. and Chen, C.C., 1986. AIChE J., 32: 1655-1664], the extended UNIQUAC equation of Sande r et al. [Sander, B., Fredenslund, A. and Rasmussen, P., 1986. Chem. E ng. Sci., 41: 1171-1183], and the modified Wilson and NRTL models prop osed by Tan [Tan, T.C., 1985. AIChe J., 31: 2083-2085; Tan, T.C., 1987 . Chem. Eng. Res. Des., 65: 355-366; Tan, T.C., 1990. Trans. Ind. Eng. Chem., 68: 93-102]. The results were compared with the data predicted by the modified Wilson and NRTL models of Tan. The mean absolute devi ations in vapour-phase mole fraction and bubble points for the salt-fr ee system were about 0.002 and 0.02, respectively. The mean absolute d eviations in vapour-phase mole fraction and bubble points for both sal t systems, over 252 data points, were about 0.004 and 0.21, respective ly, using the electrolytic NRTL model of Mock et al., 0.009 and 0.44 u sing the extended UNIQUAC model of Sander et al., 0.024 and 0.38 using Tan's modified Wilson model, and 0.019 and 0.15 using Tan's modified NRTL model. Both the modified Wilson and the NRTL models proposed by T an predict the vapour composition of both salt systems with a mean abs olute error of about 0.024-0.019, and the bubble points with a mean ab solute error of about 0.56.