Carbon dioxide absorption into aqueous potassium salt solutions of glutamine amino acid

Abstract

Amino acid salts (AAS) are mentioned as potential solvents for the separation and capture of carbon dioxide (CO2). This study investigates the aqueous solution of Potassium Glutaminate (K-Glu) solvent from different viewpoints including equilibrium solubility of carbon dioxide varying the concentration and absorption temperature at different pressures, reaction kinetics and mechanism between K-Glu and CO2, heat of absorption and cyclic absorption and regeneration efficiency. The reaction rate was calculated using the obtained experimental data and quasi first order overall reaction rate is proposed. The successive absorption-desorption preliminary tests showed a negligible drop in CO2 capture capacity over consecutive cycles through regeneration at 343.15 K. The proposed solvent has the advantages of high absorption rate and capacity (compared with monoethanolamine and N-methyldiethanolamine) with interesting aspects such as lower corrosion rate, environmental biening and high resistance against thermal and oxidative degradation covering the shortcomings of conventional amines, which considers it as a potential new solvent.