Modeling of supercritical hydrogen thermodynamic properties using cubic and SAFT type equations of state

Abstract

Hydrogen, recognized as a future fuel, is considered one of the most sustainable energy sources. Accurate prediction of its thermophysical properties, particularly at high pressures, is essential for the design and development of industrial applications. Equations of state (EoSs), as practical tools for thermodynamic modeling, provide a reliable means of predicting hydrogen's thermodynamic properties. However, due to the variety of available EoSs comparing their performance in predicting the thermodynamic behavior of supercritical hydrogen can help optimize their application in real systems. This study assessed the accuracy of the PR, SRK, Quantum-corrected PR (QPR), three versions of the PρT-SAFT, and five versions of the PC-SAFT EoSs in predicting the thermodynamic properties of supercritical hydrogen under a vast range of pressures (10–2000 MPa) and temperatures (100–1000 K), including volumetric properties, caloric properties, and the Joule-Thomson effect. Additionally, the accuracy of SAFT type EoSs in reproducing hydrogen’s critical point was evaluated, revealing that the rescaled versions of PρT-SAFT EoS yield the most precise predictions of hydrogen's thermodynamic properties. Additionally, a comparison of SAFT and QPR type EoSs for predicting hydrogen's saturated thermodynamic properties shows that QPR performs best. Lastly, the ability of all eleven EoSs to accurately describe the thermodynamic properties of supercritical hydrogen in a limited range of pressures (10–100 MPa) and temperatures (100–400 K), which are more relevant to industrial applications, were investigated and compared with molecular dynamics simulation results. In these regions, the EoSs show promising results, with SRK and PρT-SAFT delivering the best performance.