A new two-parameter cubic equation of state for calculation of phase behavior of pure compounds

A new two-parameter cubic equation of state (CEOS) has been developed for calculation of phase behavior of hydrocarbons and non-hydrocarbons. The Kim et al. expression is used for the repulsive term and a new expression is proposed for the attractive term. The energy, a, and the covolume, b, parameters of the new CEOS are dependent on reduced temperature and acentric factor that are obtained from the criticalproperties of the pure fluids. Using the new CEOS, in comparison with experimental data the overall average deviations are 1.07, 7.2, 2.23, and 2.37%, respectively, for the vapor pressure, liquid density, vapor volume, and enthalpy of vaporization in subcritical regions for 45 pure components. Moreover, the calculation of the compressibility factor shows that the results of the new CEOS with those obtained fromPR and SRK indicate that the new CEOS shows better accuracy with reduction of average deviation for simple and polar components.

کلیدواژه ها:

New Cubic Equation of State ، Vapor-liquid Equilibria ، Saturation properties