Cross Second Virial Coefficients and Dilute Gas Transport Properties of the Systems (N₂ + C₃H₈), (C₂H₆ + C₃H₈), and (H₂S + C₃H₈) from Ab Initio-Based Intermolecular Potentials

Abstract

The cross second virial coefficients and the dilute gas shear viscosities, thermal conductivities, and binary diffusion coefficients of the (N₂ + C₃H₈), (C₂H₆ + C₃H₈), and (H₂S + C₃H₈) systems were determined at temperatures from 150 to 1200 K using statistical thermodynamics and the kinetic theory of molecular gases. The required N₂-C₃H₈, C₂H₆-C₃H₈, and H₂S-C₃H₈ intermolecular potential energy surfaces (PESs) were developed as part of this work, while suitable N₂-N₂, H₂S-H₂S, C₂H₆-C₂H₆, and C₃H₈-C₃H₈ PESs were already available from our studies on the respective pure gases. All of these PESs are based on high-level quantum-chemical ab initio calculations and are represented in analytical form by site-site interaction functions. The agreement between the computed values for the investigated properties and the few experimental data available in the literature is satisfactory. In addition to tables of the calculated property values, we provide practical correlations for the cross second virial and dilute gas binary diffusion coefficients of the three investigated systems. The present work completes a series of computational studies covering the 15 binary systems formed by the common natural gas components CH₄, C₂H₆, C₃H₈, N₂, CO₂, and H₂S. Because correlations for the dilute gas binary diffusion coefficients of the systems (CH₄ + N₂), (CH₄ + CO₂), (CH₄ + H₂S), (H₂S + CO₂), (CH₄ + C₃H₈), and (CO₂ + C₃H₈) were not provided in the previous papers, we provide such correlations in the present work.