Abstract: The vapor liquid equilibrium (VLE) data of benzene-n-heptane-ethanol ternary system under pressure of 101. 3, 302. 5, 506. 8, 709. 3, 810. 6 kPa were determined with the double circulating VLEdevice under pressure. The ternary VLEdata were predicted with multicomponent Wilson equation, and the energy paired parameters were obtained from the correlation of VLEfor three binary systems i. e. benzene-n-heptane, benzene-ethanol, n-heptane-ethanol under corresponding pressure. The good agreements between predicted values and experimental data were obtained.

Key words: Vapor liquid equilibrium under pressure, Benzene-n-heptane-ethanol system, Energy paired parameters