CORRELATION AND PREDICTION OF THE VAPOR-LIQUID-EQUILIBRIA OF THE BINARY AND TERNARY-SYSTEMS INVOLVED IN MTBE SYNTHESIS

The possibility of correlating and predicting the vapor-liquid equilib ria of the binary and ternary systems formed by isobutene, methyl-tert -butyl ether (MTBE) and methanol has been considered. The predictive w ork is based on three methods: (i) Tassios' method, which requires onl y a limiting activity coefficient determined by gas chromatography for each binary system; (ii) the UNIFAC method, based on the application of the group contribution concept and (iii) Vetere's method, which hin ges only on the pure component properties. The literature for the bina ry systems isobutene/methanol and MTBE/methanol have been correlated u sing the NRTL equation or predicted according to the above procedures. The ternary system of isobutene/MTBE/methanol has been studied at thr ee temperatures using an experimental procedure which avoids the analy sis of both phases at the equilibrium. A comparison is reported betwee n the experimental and the predicted equilibrium data in order to eval uate the reliability of the three prediction methods.