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



Tobias Neumann, Stefan Herrig, Ian Bell, Robin Beckmüller, Eric W. Lemmon, Monika Thol, Roland Span


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 phase equilibria states. The mixture model is formulated in terms of the Helmholtz energy and is based on the EOS-CG of Gernert and Span (2016). The new model presented here (EOS-CG-2021) is an update and extension of the previous version, and is composed of 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. Currently available EOS-CG models are summarized and the new model is validated and analyzed with the use of comparisons to experimental data as well as 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.
International Journal of Thermophysics


Neumann, T. , Herrig, S. , Bell, I. , Beckmüller, R. , Lemmon, E. , Thol, M. and Span, R. (2023), EOS-CG-2021: A Mixture Model for the Calculation of Thermodynamic Properties of CCS Mixtures, International Journal of Thermophysics, [online],, (Accessed February 29, 2024)
Created November 16, 2023, Updated December 1, 2023