A brief overview of four related papers on SAFT-family equation-of-state modeling of ionic liquids (ILs) and deep eutectic solvents (DES), co-authored by Cleiton S. Beraldo, Xiaodong Liang, Georgios M. Kontogeorgis, and Luis A. Follegatti-Romero.
DOI: 10.1016/j.ces.2023.119610 Journal: Chemical Engineering Science, Vol. 285 (2024), Article 119610 Authors: Cleiton S. Beraldo, Xiaodong Liang, Luis A. Follegatti-Romero
Introduces a predictive parametrization strategy for the SAFT-VR Mie equation of state applied to imidazolium-based ionic liquids, using COSMO-derived molecular volume to estimate the segment number, segment diameter, and segment energy — requiring no fitting to experimental phase-equilibrium data. The approach is used to predict the solubility of CO₂ and CH₄ in a range of ionic liquids up to high pressures, showing that the model can accurately capture the phase behavior of these gas + IL systems from molecular structure alone.
Key points:
- Predictive SAFT-VR Mie parametrization based solely on COSMO molecular volume.
- Successfully predicts CO₂ and CH₄ solubility in imidazolium ILs at high pressure.
- Establishes the "volume-based" parametrization concept extended in the next paper.
DOI: 10.1016/j.ces.2024.120748 Journal: Chemical Engineering Science, Vol. 301 (2025), Article 120748 (Open Access) Authors: Cleiton S. Beraldo, Xiaodong Liang, Luis A. Follegatti-Romero
Extends the COSMO-volume-based SAFT-VR Mie parametrization from the previous paper (originally developed for gas solubility) to a broader set of properties: density, isobaric heat capacity, isobaric expansivity, isothermal compressibility, and speed of sound for pure imidazolium ionic liquids, plus speed of sound and excess enthalpy for their mixtures with ethanol or water. Only density data are used in parameter estimation, and ionic liquids are modeled both as non-associating and associating components, testing the transferability/extrapolation power of the method.
Key points:
- Parametrization requires only density data, exploiting the strong correlation between COSMO volume and SAFT-VR Mie molecular parameters.
- Validated against multiple pure-IL and IL + ethanol/water mixture properties.
- Demonstrates good extrapolation power beyond the original estimation domain (density → other properties).
DOI: 10.1016/j.fluid.2025.114479 Journal: Fluid Phase Equilibria, Vol. 598 (2025), Article 114479 (Open Access) Authors: Cleiton S. Beraldo, Luis A. Follegatti-Romero, Georgios M. Kontogeorgis, Xiaodong Liang
Compares SAFT-VR Mie and PC-SAFT for modeling CO₂ solubility in deep eutectic solvents (DES), examining the effect of combining rules and cross-association between CO₂ and DES. The Hudson–McCoubrey combining rule gives solubility predictions comparable to those obtained by fitting an optimized unlike-segment interaction energy parameter, while the classical Lorentz–Berthelot rule fails for hydrophobic DES mixtures. Both EoS provide reliable predictions overall, but the best modeling strategy (combining rule choice, association scheme) depends on the hydrophilicity of the DES.
Key points:
- Hudson–McCoubrey combining rule performs comparably to a fitted unlike-energy parameter for CO₂–DES solubility.
- Lorentz–Berthelot combining rule is inaccurate for hydrophobic DES systems.
- SAFT-VR Mie and PC-SAFT are both reliable, but the optimal strategy depends on DES hydrophilicity.
- CO₂–DES cross-association has negligible impact on predictions, though a detailed hydrogen-bonding description generally improves accuracy.
DOI: 10.1016/j.fluid.2025.114632 Journal: Fluid Phase Equilibria, Vol. 603 (2026), Article 114632 Authors: Cleiton S. Beraldo, Xiaodong Liang, Georgios M. Kontogeorgis, Luis A. Follegatti-Romero
Applies the electrolyte/association-extended SAFT-VRE Mie and eSAFT-VR Mie equations of state to model the thermodynamic properties of imidazolium ionic liquids dissolved in water, methanol, and ethanol. The work builds on the group's earlier SAFT-VR Mie framework for pure and mixed ILs, extending it to explicitly account for association/electrolyte-like interactions relevant to IL behavior in protic solvents.
Key points:
- Extends prior SAFT-VR Mie IL modeling framework to SAFT-VRE Mie and eSAFT-VR Mie variants.
- Focused on IL + water, + methanol, and + ethanol systems.
- Part of the broader research line connecting COSMO-based parametrization, association theory, and IL/DES thermodynamic modeling.
Together, these four papers trace a coherent research arc:
- A predictive, COSMO-volume-based SAFT-VR Mie parametrization for gas solubility in ILs.
- Extension of that same parametrization to pure IL properties and IL/alcohol/water mixtures.
- Application of SAFT-VR Mie and PC-SAFT to CO₂ solubility in deep eutectic solvents, focusing on combining rules and association effects.
- Extension to association/electrolyte-aware SAFT variants (SAFT-VRE Mie, eSAFT-VR Mie) for IL + water/alcohol systems.
This progression reflects a broader effort to build transferable, physically-grounded SAFT-based models for ionic liquids and DES relevant to CO₂ capture applications.