Application of the excess entropy scaling to the transport properties of n-alkanes, jet fuels, and a biodiesel over the entire vapor-liquid phase equilibria

In this study, the entropy scaling developed for the transport properties, namely the thermal conductivity, dynamic viscosity, and self-diffusion coefficient, has been extended and applied to the dense gas and liquid regions, when the configurational entropy is the only requirement. Two approaches are proposed in the excess entropy scaling. First, the general formula Gamma aSex Gamma 0(Gamma/Gamma 0)HS = bexp with reducing quantity Gamma 0 - representing the Boltzmann dilute gas properties - is used to provide universal exponents for the thermal conductivity and viscosity. Model predictions with excess entropies calculated simultaneously via the multiparameter Helmholtz energy equations of state (EoS) and the Peng-Robinson (PR) cubic EoS were compared to the experimental data by achieving qualitative agreement over the entire phase diagram. In the second approach, for a single-component model derivation, the transport property formula was decomposed into dilute, background, and critical enhancement terms. The excess entropy is hidden in the background term, which was regressed against the density. Moreover, the proposed universal formula for the excess entropy scaling was tested against the molecular dynamics' viscosity data for the Lennard-Jones fluid. The viscosity and thermal conductivity of carbon dioxide + hydrogen and methane + hydrogen were also predicted using the entropy scaling of pure-compounds. The methods were developed and examined based on a broad variety of fluids including refrigerants, alcohols, ethers, alkanes, jet fuels, and a biodiesel.