Density estimation of normal alkanes from the statistical-thermodynamic perturbation theory based equation of state

Abstract

An analytical equation of state (EoS) proposed by Ihm-Song-Mason (ISM) is employed to calculate the density of normal alkanes from methane to decane. The best available values of the Lennard-Jones (12,6) parameters have been used to evaluate the second virial coefficient of the EoS for each compound. The second virial coefficient is not very sensitive to the feature of the intermolecular potential. The remaining parameters in the EoS depend only on the repulsive part of the potential. Consequently, they are insensitive to the details of the interaction potential. The calculated second virial coefficients in conjunction with other temperature-dependent parameters of the EoS are employed to predict the density of all alkanes (C1-C10). There is a good agreement comparison between the experimental values of density and the calculated values from ISM EoS for all of the compounds.