Abstract

Analysis of the equations of state of the hard convex body chain and hard spheres has been done for predicting the vapor liquid
equilibrium (VLE) of simple fluids of n-alkanes. The repulsive part of the Boublik equation of state for the hard convex body chain has
been found as an equivalent alternative either for the well known Carnahan-Starling repulsive term or the established van der Waals
repulsive part of hard spheres equations of state. The attractive parts of these equations of state have the similar form as that of the van
der Waals and are obeying the power-law temperature dependency. Add-on separation method of compressibility factor has been used
for these equations of state. The simulated data for VLE densities from these equations of state are found to agree well with the available
experimental data for n-alkane fluids.

Key words: equations of state; vapour liquid equilibrium; critical parameters; hard convex body chain