VAPOR-LIQUID-EQUILIBRIUM OF THE METHANOL-TERT-BUTYL METHYL-ETHER (MTBE) SYSTEM

Vapor-liquid equilibrium data for the methanol-tert-butyl methyl ether (MTBE) system have been measured covering the whole concentration ran ge at six temperatures between 298.15 and 338.15 K. A Gibbs-Van Ness t ype apparatus for total vapor-pressure measurements of binary mixtures has been used. Data reduction has been carried out by means of a modi fied Barker's method using a Pade approximant to describe the excess G ibbs energy. The methanol-MTBE mixtures show positive deviations from ideality. The calculated values for the excess Gibbs energy are modera tely positive and only slightly temperature dependent. Excess enthalpy values calculated from the temperature dependence of the excess Gibbs energy are in agreement with experimental data found in the literatur e. The experimental data are analyzed in terms of the UNIQUAC model, s everal versions of the UNIFAC model, the Lattice-Fluid model and the L attice-Fluid Associated Solution Model.