Some Observations Regarding the SAFT-VR-Mie Equation of State

Abstract

This study demonstrates that the advanced theoretical basis and the consequential numerical complexity do not always guarantee the success of EOS models in predicting the experimental thermodynamic property data. Although one of the best versions of SAFT, namely SAFT-VR-Mie might have doubtless advantages in predicting the data of nonspherical molecules, once again it is shown that there is a price to pay for the excessive model's complexity. In particular, the present study reveals a previously unnoticed kind of numerical pitfalls, yet generated by the chain term of the SAFT-VR-Mie EOS. A possible way of avoiding the numerical pitfall under consideration is proposed.

Implementation of CP-PC-SAFT and CS-SAFT-VR-Mie for Predicting Thermodynamic Properties of C1–C3 Halocarbon Systems. I. Pure Compounds and Mixtures with Nonassociating Compounds

“…Such behavior resembles the well-known numerical pitfall caused by multiple volume roots, which leads to appearance of an additional artificial phase equilibria. However, analysis indicates that in the current case, this behavior is originated by a discontinuity of isotherms, previously detected for another version of SAFT-VR-Mie Figure shows that at some very low negative pressures, the isotherms cease and reappear at some very high positive pressures.…”

Modeling the viscosity of pure imidazolium-based ionic liquids using SAFT-VR-Mie EoS

“…It has also been proved by Kalikhman et al [51] that some possible printing errors have appeared in the previous publications of SAFT-VR Mie's chain term. In addition, a possible way of avoiding the numerical pitfalls for the chain term of SAFT VR Mie has been proposed by them that are used in the current work.…”

“…In addition, a possible way of avoiding the numerical pitfalls for the chain term of SAFT VR Mie has been proposed by them that are used in the current work. For details, the reader is referred to a complete review by ref [43,51].…”

Implementation of SAFT + Cubic, PC-SAFT, and Soave–Benedict–Webb–Rubin Equations of State for Comprehensive Description of Thermodynamic Properties in Binary and Ternary Mixtures of CH4, CO2, and n-C16H34

“…Unlike the entirely empirical SBWR and the semiempirical SAFT + Cubic, the structures of the theoretically advanced SAFT models and the related approaches − are focused on representing the molecular simulation rather than the experimental results. As a consequence, they are typically unable to fit the pure compound critical and subcritical data simultaneously. − In addition, they might be affected by the undesired numerical pitfalls, such as predicting the unrealistic phase equilibria and the nonphysical negative values of heat capacities. − Nevertheless, these models are particularly important for both science and industry. PC-SAFT is one of the most successful and widely used theoretically based fluid phase equations.…”