Thermodynamics Research Center / ThermoML | Fluid Phase Equilibria

ABSTRACT

Isothermal vapor liquid equilibrium (VLE) at 333.15K and 353.15K for four binary mixtures of benzene + toluene, benzene +N-methylformamide, toluene + m-xylene and toluene +N-methylformamide have been obtained at pressures ranged from 0 kPa to 101.3 kPa. The NRTL, UNIQUAC and Wilson activity coefficient models have beenemployed to correlate experimental pressures and liquid mole fractions. The non-ideal behavior of the vapor phase has been considered by using the Soave Redlich Kwong equation of state in calculating the vapor mole fraction. Liquid and vapor densitieswere also measured by using two vibrating tube densitometers. The P x y diagram and the activity coefficient indicate that two mixtures of benzene + toluene and toluene + m-xylenewere close to the ideal solution. However, two mixtures containing N-methylformamide present a large positive deviation from the ideal solution. The excess Gibbs energy in the benzene + toluene mixture is negative indicates that it is an exothermic system.