VAPOR-LIQUID-EQUILIBRIUM OF THE ACETONE-METHANOL SYSTEM IN THE PRESENCE OF KSCN AND COMPARISON WITH OTHER SALTS

The effect of KSCN at salt mole fractions of 0.01-0.05 and at saturati on on the VLE of the binary acetone-methanol system has been experimen tally investigated at 101.32 kPa using a modified Othmer equilibrium s till. The experimental data were correlated by the electrolytic NRTL m odel [B. Mock, L.B. Evans and C.C. Chen, AIChE J., 32 (1986) 1655-1664 ], the extended UNIQUAC equation [B. Sander, A. Fredensland and P. Ras mussen, Chem, Eng. Sci., 41 (1986) 1171-1183] and the modified Wilson and NRTL models proposed by Tan [T.C. Tan, AIChE J., 31 (1985) 2083-20 85; Chem. Eng. Res. Des., 65 (1987) 355-366; Trans. Inst. Chem. Eng., 68 (1990) 93-102]. The results were compared with those obtained by Ta n's predictive models. A crossover between the salting-out and salting -in effects on acetone and a non-azeotropic minimum in the temperature -composition diagram were observed at low and high salt concentrations . Based on the solubility data in the mixture, comparisons with the ef fect of other salts on the same mixed solvent were made. (C) 1997 Else vier Science B.V.