PC-SAFT Modeling of CO₂ Solubilities in Deep Eutectic Solvents

Abstract

Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT), a physically based model that accounts for different molecular interactions explicitly, was applied to describe for the first time the phase behavior of deep eutectic solvents (DESs) with CO2 at temperatures from 298.15 to 318.15 K and pressures up to 2 MPa. DESs are mixtures of two solid compounds, a hydrogen bond donor (HBD) and a hydrogen bond acceptor (HBA), which form liquids upon mixing with melting points far below that of the individual compounds. In this work, the HBD is lactic acid and the HBAs are tetramethylammonium chloride, tetraethylammonium chloride, and tetrabutylammonium chloride. Two different modeling strategies were considered for the PC-SAFT modeling. In the first strategy, the so-called pseudo-pure component approach, a DES was considered as a pseudo-pure compound, and its pure-component parameters were obtained by fitting to pure DES density data. In the second strategy, the so-called individual-component approach, a DES was considered to consist of two individual components (HBA and HBD), and the pure-component parameters of the HBA and HBD were obtained by fitting to the density of aqueous solutions containing only the individual compounds of the DES. In order to model vapor-liquid equilibria (VLE) of DES + CO2 systems, binary interaction parameters were adjusted to experimental data from the literature and to new data measured in this work. It was concluded that the individual-component strategy allows quantitative prediction of the phase behavior of DES + CO2 systems containing those HBD:HBA molar ratios that were not used for k(ij) fitting. In contrast, applying the pseudo-pure component strategy required DES-composition specific k(ij) parameters.

Measurement and PC-SAFT modeling of solid-liquid equilibrium of deep eutectic solvents of quaternary ammonium chlorides and carboxylic acids

“…Ji et al [38], Nann et al [39] and Passos et al [40] reported the use of PC-SAFT to model IL solutions while Zubeir et al [28] used this EoS to model the CO 2 solubilities in DES with [Ch]Cl, and different symmetrical quaternary ammonium chlorides serving as HBA. The various authors treated ILs as molecules with associative behavior by using a 2B association scheme (according to Huang and Radosz [41]), where to each molecule two association sites (mimicking the cation and the anion) are assigned and association interactions between unlike sites are allowed.…”

“…Additionally, Perturbed-Chain SAFT (PC-SAFT) [26], the most prominent modification of original SAFT, was already successfully applied to systems containing DES. Verevkin et al [27] used PC-SAFT to model infinite dilution activity coefficients of 23 different solutes in [Ch] Cl:glycerol and Zubeir et al [28] used PC-SAFT to model the CO 2 solubility in quaternary ammonium salts þ lactic acid mixtures.…”

Modelling and prediction of the thermophysical properties of aqueous mixtures of choline geranate and geranic acid (CAGE) using SAFT-γ Mie

“…9 In addition to molecular-dynamics simulations, molecularbased equations of state are useful tools to study and predict the thermodynamic properties of complex uid mixtures. The perturbed-chain statistical associating uid theory (PC-SAFT) 10 has been shown to describe accurately the solid-liquid equilibria of a number of DESs [11][12][13] and the liquid-liquid equilibria data of several RTILs. [14][15][16] In these studies, short-range association sites were used to mimic hydrogen bonding interactions between species but the anion and cation were not treated as explicitly charged species.…”

Superbase‐Added Choline Chloride‐Based Deep Eutectic Solvents for CO2 Capture and Sequestration

“…The same group later analyzed the operating conditions for CO 2 capturing process using these DESs . Phase behavior of (alkylammonium chloride + lactic acid) DESs using perturbed‐chain statistical associating fluid theory (PC‐SAFT) were modeled by Held, Kroon and coworkers . DES constituted of (monoethanolamine hydrochloride + ethylenediamine) is recently demonstrated to effectively capture CO 2 by Choi group .…”

“…[28][29][30][31][32] Phase behavior of (alkylammonium chloride + lactic acid) DESs using perturbedchain statistical associating fluid theory (PC-SAFT) were modeled by Held, Kroon and coworkers. [33] DES constituted of (monoethanolamine hydrochloride + ethylenediamine) is recently demonstrated to effectively capture CO 2 by Choi group. [34] It is imperative to mention two review articles that have recently appeared.…”