Enhanced carbon dioxide membrane‐based absorption with amino acid solutions

Abstract Background Current technologies for carbon dioxide (CO 2 ) capture are based on a variety of physical and chemical processes using absorption towers. Overcoming the high energy consumption of conventional absorption is essential to develop a process that makes sense in terms of CO 2 captured versus CO 2 emitted. In this work, we propose the use of a membrane contactor that allows an efficient gas–liquid contact and an aqueous alkaline solution with several amino acids (i.e. arginine, methionine, valine, serine, 6‐aminohexanoic acid) as the absorption liquid. Results Results show clear differences in absorption performance among the studied amino acids, with arginine as the best choice. Using arginine does not only lead to the highest mass transfer coefficient ( ca 0.004 m 3 m −2 min −1 ) in the membrane contactor but also a remarkable CO 2 absorption capacity without the need for an alkaline component that enhances the reaction and the mass transfer. Conclusion The use of membrane contactors with a green solvent is a promising step that needs further studies. As the results demonstrate, arginine has shown a great performance; thus, it has been chosen for further investigation. © 2023 Society of Chemical Industry.