A simple calculation of the pressure and liquid mole fraction at the VLE of ethane/light hydrocarbon binary mixtures

An analytical expression for the calculation of the pressure and liquid mol e fraction at the VLE of ethane/light hydrocarbon binary mixtures is propos ed. The model is based on a simple analytical expression for the vapor pres sure of pure non-polar fluids, which, for a given temperature, only require s as input the values of the Lennard-Jones molecular parameters and the ace ntric factor. A properly modified Lorentz-Berthelot mixing rule is used, th e interaction parameters being given as simple functions of the temperature and composition with eight constants for each binary mixture. The model is shown to reproduce accurately and simply the pressure (for a given liquid mole fraction) or the liquid composition (for a given pressure) of six etha ne + hydrocarbon systems at different temperatures.