EOS-CG-2021: A Mixture Model for the Calculation of Thermodynamic Properties of CCS Mixtures

Abstract

Thermodynamic properties for CCS-relevant mixtures can be calculated with the fundamental equation of state presented in this work over wide ranges of pressure, temperature, and composition for gas, liquid, and supercritical states, as well as for phase equilibria. The mixture model is formulated in terms of the Helmholtz energy and is based on the EOS-CG model of Gernert and Span (J Chem Thermodyn 93:274, 2016]. The new model presented here (EOS-CG-2021) is an update and extension of the previous version, and covers the following sixteen components: carbon dioxide, water, nitrogen, oxygen, argon, carbon monoxide, hydrogen, methane, hydrogen sulfide, sulfur dioxide, monoethanolamine, diethanolamine, hydrogen chloride, chlorine, ammonia, and methyl diethanolamine. Previously published elements of the model are summarized, and new elements are validated and analyzed with the use of comparisons to experimental data and by assessing the physical and extrapolation behavior of the equations. A comprehensive study on the representation of multicomponent mixture data was carried out to show the high accuracy and application range of the EOS-CG-2021.