Development of Monoethanolamine Chloride-Ethylene Diamine Deep Eutectic Solvent for Ffficient Carbon Dioxide Capture

Deep eutectic solvents (DES) emerge as a compelling class of ionic liquids, with distinct advantages over traditional solvents, particularly in the realm of CO2 capture. In the present study, [MEACl][EDA] is synthesized across various molar ratios (1:3 to 1:10) and combined with the results of Differential Scanning Calorimetry (DSC) to identify DESs. The DESs are further characterized using Fourier Transform Infrared Spectroscopy (FTIR), and the properties and performance of the DESs with diverse water contents (30–60 wt%) are systematically studied for CO2 capture. The optimal aqueous solution is identified based on the CO2 uptake and viscosity, followed by the evaluation of the cyclic absorption experiments. Results demonstrate that 40 wt% of [MEACl][EDA] DES with (1:5) molar ratio exhibits higher CO2 uptake (22.09 wt%) and comparable viscosity (4.401 mPa·s before and 13.330 mPa·s after CO2 capture at 25 °C) compared to aqueous 40 wt% MEA (15.74 wt% CO2 capture capacity, viscosity of 3.318 mPa·s before and 8.413 mPa·s after CO2 capture), and its absorption rate is also more favorable than the aqueous MEA. Furthermore, recycling studies reveal ∼ 88 % regeneration of the aqueous DES solution at 100 °C.