| dc.description.abstract | Carbon dioxide (CO2) is a harmful greenhouse gas and a major contributor to global warming. Therefore, removing CO2 from industrial point sources is crucial. Amine solvents are widely used in industry for CO2 removal from flue gas; however, these solvents have significant drawbacks, including corrosiveness, volatility, low biodegradability, and high energy consumption for regeneration. In recent years, deep eutectic solvents (DES) have emerged as promising alternative absorbents for CO2 capture. DESs are composed of two or more purified compounds, including hydrogen-bond acceptors (HBA) and hydrogen-bond donors (HBD), with a eutectic point temperature lower than that of an ideal liquid mixture. These solvents exhibit negligible vapor pressure, high thermal stability, low cost, good regenerability, low toxicity, and tunable properties, which can be adjusted by varying the ratio of the ions. Additionally, they are relatively simple to prepare.
L-arginine is a natural, non-toxic, biodegradable, and environmentally friendly product, with several studies reporting its significant effectiveness in CO2 capture. Glycerol, often considered waste in the petroleum industry due to its surplus, presents an eco-friendly option for recovery. This study selected L-arginine hydrochloride/glycerol as the target deep eutectic solvent (DES) and, by comparing it with the literature, aimed to observe how changes in the hydrogen bond acceptor affect absorption capacity and basic physical properties. The physical properties of L-arginine hydrochloride/glycerol, including freezing point, density, and viscosity, were thoroughly examined. CO2 absorption was measured under varying molar ratios, temperatures, and water contents. The 1:9 DES at 70°C exhibited the highest solubility, reaching 0.754 mol_CO2/mol_DES. Additionally, regeneration experiments were performed on the DES. The interaction mechanism between DES and CO2 was explored using FTIR, 1H NMR, and 13C NMR. | en_US |