The enhanced enzymatic performance of carbonic anhydrase on the reaction rate between CO2 and aqueous solutions of sterically hindered amines

Abstract

AbstractThe kinetics of the reactions of carbon dioxide (CO2) with aqueous solutions of two different sterically hindered amines (SHAs), 2‐amino‐2‐ethyl‐1,3‐propanediol (AEPD) and 2‐amino‐2‐methyl‐1,3‐propanediol (AMPD), in the presence and absence of carbonic anhydrase (CA) was investigated experimentally using stopped‐flow conductimetry. The amine concentration, CA concentration, and temperature were varied within the ranges of 0.1–0.5 kmol·m–3, 0–125 g·m–3, and 298–353 K, respectively. Based on pseudo first‐order reaction conditions, the intrinsic reaction rate (ko) was obtained according to a modified termolecular reaction mechanism. The obtained results showed that the reaction rate between the SHA solutions (either aqueous AEPD or aqueous AMPD) and CO2 was enhanced significantly upon adding small amounts of CA as a promoter. Such a result supports the use of the aforementioned solvent system as a candidate for CO2 capture. © 2020 Society of Chemical Industry and John Wiley & Sons, Ltd.