Thermophysical Properties of Gaseous H₂S-N₂ Mixtures from First-Principles Calculations

Abstract

The cross second virial coefficient and three dilute gas transport properties (shear viscosity, thermal conductivity, and binary diffusion coefficient) of mixtures of hydrogen sulfide (H2S) and nitrogen (N2) were determined with high accuracy at temperatures up to 1200 K using statistical thermodynamics and the kinetic theory of molecular gases, respectively. The required intermolecular potential energy surface (PES) for the H2S-N2 interaction is presented in this work, while the H2S-H2S and N2-N2 PESs were reported previously. All three PESs are based on high-level quantum-chemical ab initio (i.e. first-principles) calculations. There is only very limited experimental information available on the second virial coefficients of H2S-N2 mixtures, and there appear to be no experimental data at all for the transport properties. Thus, the present predictions constitute a substantial increase in our knowledge of the thermophysical properties of this system, which are of practical relevance for modeling sour natural gas.