Reaction kinetics of carbon dioxide with 2-amino-2-hydroxymethyl-1,3-propanediol in aqueous solution obtained from the stopped flow method


Abstract: Carbon dioxide (CO_2) capture has attracted great interest these days due to the role of CO_2 in global warming and its effects in industrial processes. Thus, higher energy efficient and affordable technologies are required for its removal so as to address these problems. In this work, the reaction kinetics of CO_2 with 2-amino-2-hyroxymethyl- 1,3-propanediol (AHPD), a sterically hindered amine (SHA), was studied by direct stopped flow method. The aim was to research CO_2 absorbent with better CO_2 absorption capacity and reaction kinetics than the commonly applied amine solvents. The study was carried out at 288, 298, and 303 K in a concentration range of 0.5-2.0 kmol/m^3 of AHPD. Based on the pseudo-first-order for the reaction of CO_2, it was found that the reaction can be modeled by a single termolecular reaction mechanism. The reaction rate between CO_2 and aqueous solution of AHPD was 9.99, 12.03, and 16.05 m^3/kmol.s at 288, 298, and 303 K, respectively, while its activation energy was 31.59 kJ/mol. The results obtained were compared with published reaction rate data of other amines. The present study shows that AHPD is a potential SHA as CO_2 absorbent if the reaction rate is enhanced by an additional amine.

Keywords: AHPD, CO_2 capture, sterically hindered amine, stopped flow method

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