Modeling of Vapor Liquid Equilibrium Data for Thyme Essential Oil Based on UNIQUAC Thermodynamic Model

Abstract

Vapor Liquid Equilibrium (VLE) data for natural ingredients and essential oils has not studied at all yet. It is because of the complexity of these mixtures. In this study, the equilibrium concentration of the mixture components was studied by using UNIQUAC model at different pressures. This model is capable of determining the temperature between 70°C to 170°C and the pressure limits 30 Kpa to 202 Kpa. The Modeling results showed Thymol in the liquid phase was increased from 50% molar to 90% molar in constant pressure by increasing the temperature from bubble point to dew point temperature. Thymol concentration in the liquid phase was increased from 42% molar to 78% molar by increasing the water concentration of the mixture at a constant pressure of 100 Kpa and constant temperature 177°C. Another obtaining result showed that Thymol concentration in the triple mixture, which includes 30% molar water, 35% molar Thymol, and 35% molar Cymene in liquid phase, was increased from 60% molar to 82% molar at constant temperature of 177°C by decreasing the pressure from 100 Kpa to 20 Kpa.

KEYWORDS: Essential oil, VLE, UNIQUAC, Modeling