The operational and economic constraints suffered by amine solvents for CO2 removal have motivated the research on an alternative solvent with better performance and cost-effectiveness. Amino acid salt (AAS) has been identified as an interesting green solvent, an alternative to commercial amine solvents. The present work evaluated the physicochemical and CO2-solubility properties of potassium L-cysteine (K-CYS), a naturally occurring amino-acid-based solvent for CO2 removal from natural gas. Its physicochemical properties, including density, viscosity, and refractive index, were measured at different temperatures ranging between 298.15 and 333.15 K and a concentration range of 5 to 30 wt.%. Based on the experiment, all properties were found to decrease with increasing temperature and increase with increasing concentration. The experiments also demonstrated a significant reduction of CO2 loading from 2.4190 to 1.1802 mol of CO2/mol of K-CYS with increasing solvent concentration from 10 to 30 wt% at 313.15 K and 20 bar (g).
- amino acid salts
- CO removal
- L-cysteine (K-CYS)
- sterically hindered amino acids (SHAA)