Kinetics of CO₂ absorption into a novel 1‐diethylamino‐2‐propanol solvent using stopped‐flow technique

Abstract

A stopped‐flow apparatus was used to measure the kinetics of carbon dioxide (CO2) absorption into aqueous solution of 1‐diethylamino‐2‐propanol (1DEA2P) in terms of observed pseudo‐first‐order rate constant (ko) and second‐order reaction rate constant (k2), in this work. The experiments were conducted over a 1DEA2P concentration range of 120–751 mol/m3, 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 CO2 absorption rate constants obtained from stopped‐flow apparatus. In addition, the pKa 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 pKa 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

Experimental study of the kinetics of the homogenous reaction of CO2 into a novel aqueous 3-diethylamino-1,2-propanediol solution using the stopped-flow technique

“…It is worth mentioning that the experimental technique used in this work has already been validated in our previous work [6,8] on the kinetics of CO 2 absorption into aqueous DEA solutions at 298 K. The results showed that the kinetics data in terms of pseudo firstorder constant (k 0 ) were in good agreement with the works of Ali et al [23,24].…”

“…All of these processes were achieved by using ''Kinetasyst'' software. Further details of the procedure have been reported in our previous work [6,8].…”

“…(32) were found to be in very good agreement with the experimental results with an AAD of 0.07%. The temperature dependency correlations pKa for MDEA, DMMEA, DEMEA, and DEA2P, obtained from the work of Hamborg and Versteeg [43], Kamps and Maurer [25], and Liu [8], are also displayed in Fig. 10.…”

“…The pH meter was used to measure the pH values of the amine solutions. The details of the procedure and equipment used in this work as well as the validation of the experimental technique and calculation procedures can be found in our published work [6,8].…”

“…The results were compared to MDEA and seven amine absorbents with faster kinetics, higher cyclic capacities and lower reaction heat were identified. 1-diethylamino-2-propanol (1DEA2P), one of the tested amines, whose chemical structure is similar to that of DEAB, was then comprehensively investigated for its reaction kinetics by Liu [8], using the stopped-flow technique. The 1DEA2P molecule contains a 2-propanol group in the place of the 2-butanol group in DEAB.…”