In practical applications, water vapor always coexists with natural gas. As such, the concentration of the ionic liquids (ILs), as promising absorbents for carbon dioxide (CO2) removal, is a crucial parameter sensitively affecting CO2 solubility. In this work, a novel amino acid anion (Glycinate) based IL was synthesized, characterized, and applied for CO2 uptake. Preliminary physicochemical measurements at temperatures of 303 to 323 K showed that increasing the IL purity has adverse effects on density, viscosity, and surface tension of the [MEA][GLY].The impact of the presence of water in the IL samples was also investigated on the CO2 loadings over the temperature ranges of 303-323 K and up to a pressure of 600 kPa. Among the four aqueous solutions of the IL, the highest CO2 loading of 1.02 (mol CO2/mol IL) was achieved for aqueous IL of 25 wt% at an equilibrium pressure of 1.35 bar and a temperature of 303.15 K. It is found that with increasing equilibrium pressure to about 6.2 bar, the loading rate has reached 1.32 (mol CO2/mol IL), which is almost 2.64 times higher than that of the conventional primary amine (0.5 mol CO2/mol IL). It is found that although the proposed IL is a promising absorbent for the capture of CO2, highly concentrated of the [MEA][GLY] is not the feasible concentration for CO2 uptake.
