Phase equilibria involved in extractive distillation of 2-methoxy-2-methylpropane plus methanol using 1-butanol as entrainer

Consistent vapour-liquid equilibrium (VLE) data at 101.32 kPa have been det ermined for the ternary system 1-butanol + methanol + 2-methoxy-2-methylpro pane, correlated by means of the Wilson, NRTL, and UNI-QUAC equations, and compared with the results predicted by using the same equations with intera ction parameters obtained from data for the relevant binary systems. The pr edictions deviated only slightly from the experimental data. The Wilson equ ation provided the most satisfactory prediction. Moreover, deviations were smaller than those obtained when the equilibrium data were predicted using the ASOG-KT and the original and modified UNIFAC group-contribution methods . The results obtained with a commercial simulator (ChemCAD IV) indicate th at extractive distillation with l-butanol as entrainer is a feasible method for the separation of 2-methoxy-2-methylpropane (MTBE) and methanol. (C) 2 000 Elsevier Science B.V. All rights reserved.