Aqueous Potassium Salt of L-Cysteine as Potential CO2 Removal Solvent: An Investigation on Physicochemical Properties and CO2 Loading Capacity

• Main Authors: Tengku Hassan, T.N.A., Mohd Shariff, A., Abd Aziz, N.F., Mustafa, N.F.A., Tan, L.S., Abdul Halim, H.N., Mohamed, M., Hermansyah, H.
• Format: Article
• Published: Multidisciplinary Digital Publishing Institute (MDPI) 2023
• Online Access: http://scholars.utp.edu.my/id/eprint/37443/; https://www.scopus.com/inward/record.uri?eid=2-s2.0-85167891926&doi=10.3390%2fsu151511558&partnerID=40&md5=52d41710dfc60340a8fa7c4c0accea0a

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). © 2023 by the authors.