(99c) Utilization of Choline Cholire with Levulinic Acid and Phenylacetic Acid Based Deep Eutectic Solvents for Efficient CO2 Capture

Choline chloride ([Ch][Cl]) + levulinic acid [LA] and ([Ch][Cl] + phenylacetic acid [PAA] deep eutectic solvent (DES) is studied as a suitable material for CO2 capturing purposes. The most relevant physicochemical properties of this solvent are reported together with the CO₂ solubility as a function of temperature. A theoretical study using both Density Functional Theory and Molecular Dynamics approaches is carried out to analyze the properties of this fluid from the nanoscopic viewpoint and their relationship with the macroscopic behavior of the system and its ability for CO₂ capturing. The behavior of liquid – gas interface is also studied and its role on the CO₂ absorption mechanism is analyzed. The combined experimental plus theoretical reported approach leads to a complete picture of the behavior of this new sorbent with regard to CO₂, which together with its low pricing, and the suitable environmental and toxicological properties of this natural solvent, lead to a promising candidate for CO2 capturing technological applications. Characterization techniques such as TGA, FTIR, viscosity, density, pH, and thermal conductivity analysis have been performed. Both in-situ FTIR and gas solubility measurements have also indicated the suitability of this material for CO₂ and other gases solubility. Rubotherm® sorption apparatus was employed for very accurate gas solubility experiments up to 30 bars and at 25 ºC and 50 ºC. Initial findings are reported in this communication and CO₂ solubility in [Ch][Cl]:[LA] was found to be as 2.12 mmol/g and [Ch][Cl]:[PAA] as 2.28 mmol/g. Moreover, corrosive behavior of the DES system have been experimented and compared with the most common amine based system and it has been observed that DES system has order of magnitude less corrosive behavior than the classical MEA CO₂ absorbent system.