Kinetics of CO 2 absorption into a novel 1‐diethylamino‐2‐propanol solvent using stopped‐flow technique

A stopped‐flow apparatus was used to measure the kinetics of carbon dioxide (CO 2 ) absorption into aqueous solution of 1‐diethylamino‐2‐propanol (1DEA2P) in terms of observed pseudo‐first‐order rate constant (k o ) and second‐order reaction rate constant (k 2 ), in this work. The experiments were conducted over a 1DEA2P concentration range of 120–751 mol/m 3 , and a temperature range of 298–313 K. As 1DEA2P is a tertiary amine, the base‐catalyzed hydration mechanism was, then, applied to correlate the experimental CO 2 absorption rate constants obtained from stopped‐flow apparatus. In addition, the pK a of 1DEA2P was experimentally measured over a temperature range of 278–333 K. The Brønsted relationship between reaction rate constant (obtained from stopped‐flow apparatus) and pK a was, then, studied. The results showed that the correlation based on the Brønsted relationship performed very well for predicting the absorption rate constant with an absolute average deviation of 5.2%, which is in an acceptable range of less than 10%. © 2014 American Institute of Chemical Engineers AIChE J , 60: 3502–3510, 2014