A methodology to parameterize SAFT-type equations of state for solid precursors of deep eutectic solvents: the example of cholinium chloride

resumo

Given the recent boom of applications for deep eutectic solvents (DES), there is a need for robust and accurate thermodynamic models that are able to describe them. Recent works have used molecular-based equations of state, derived from the Statistical Associating Fluid Theory (SAFT), to model DES due to their ability to explicitly account for hydrogen bonding, which is thought to govern the formation of a DES. However, the application of these association models to DES is a non-trivial task, because pure fluid data for several DES precursors are not available to be used in the model parameterization. The alternative parameterization procedures currently employed have evident flaws including the use of oversimplified association schemes, lack of transferability, inability to provide fundamental solid-liquid equilibrium data, and an overall poor accuracy. This work highlights the disadvantages of the current approaches while providing a novel methodology for the development of coarse-grained models applicable to DES. By proposing a more realistic association scheme and regressing the model parameters from experimental data that can be easily measured for a representative DES, a new coarse-grained model for [Ch]Cl, the most used DES precursor, was developed for soft-SAFT. The good performance and versatility of the new model were then successfully demonstrated through the modelling of a wide variety of [Ch] Cl-based DES, providing accurate descriptions of densities, vapor-liquid equilibria and solid-liquid equilibria data, for both binary and ternary systems. Furthermore, the novel approach can easily be applied to other SAFT-type models and extended to other solid DES precursors such as urea.

palavras-chave

VAPOR-LIQUID-EQUILIBRIA; DIRECTIONAL ATTRACTIVE FORCES; IONIC LIQUIDS; OF-STATE; PHASE-EQUILIBRIA; ACTIVITY-COEFFICIENTS; PERTURBATION-THEORY; CO2 SOLUBILITIES; ETHYLENE-GLYCOL; HEAT-CAPACITIES

categoria

Chemistry; Physics

autores

Crespo, EA; Silva, LP; Lloret, JO; Carvalho, PJ; Vega, LF; Llovell, F; Coutinho, JAP

Grupos

G4 - Materiais Renováveis e Economia Circular

Projectos

CICECO - Aveiro Institute of Materials (UID/CTM/50011/2019)

Projeto de Investigação Exploratória: Pedro Carvalho (IF/00758/2015)

agradecimentos

We thank Ruben M. Ojeda for providing some preliminary calculations for pure glycerol. This work was developed within the scope of the project CICECO - Aveiro Institute of Materials, FCT Ref. UID/CTM/50011/2019, financed by national funds through the FCT/MCTES. E. A. Crespo acknowledges FCT for the PhD Grant SFRH/BD/130870/2017 and L. P. Silva for the PhD Grant SFRH/BD/135976/2018. P. J. Carvalho also acknowledges FCT for a contract under the Investigador FCT 2015, contract number IF/00758/2015. Additional funding was provided by Khalifa University through project RC2-2019-007. This research is also supported by Project KET4F-Gas -SOE2/P1/P0823, which is co-financed by the European Regional Development Fund within the framework of the Interreg Sudoe Programme.