Experimental investigation of carbon dioxide solubility in the deep eutectic solvent (1 ChCl+3 triethylene glycol) and modeling by the CPA EoS

CO2 solubilities in the deep eutectic solvent (1 choline chloride+3 triethylene glycol) weremeasured at the four temperatures of 303.15, 313.15, 323.15 and 333.15 K and pressures up to 30 bars. Measurements were carried out in a newly designed, built and validated high pressure solubility apparatus. The measured datawere modeled by the cubic plus association (CPA) and the Soave-Redlich-Kwong (SRK) equations of state, with AARD% values of 5.52% and 7.30% for the CPA and SRK EoSs, respectively, showing the good correlative ability of both models. Furthermore, by calculating the standard Gibbs free energies of dissolution, standard enthalpies of dissolution and standard entropies of dissolution at infinite dilution, we found that the dissolution process is nonspontaneous and exothermic, with the CO2 - DES interactions being the stronger interactions. The solution becomes less chaotic and reaches a higher degree of order in the liquid phase after dissolution of CO2. (C) 2021 Published by Elsevier B.V.

Automated summary

In this study, CO2 solubilities in a deep eutectic solvent were measured at various temperatures and pressures, and modeled using mathematical equations. The results indicate that the dissolution process of CO2 is nonspontaneous, exothermic, and results in a higher degree of order in the liquid phase, with stronger CO2 - DES interactions.