In the present work, a comprehensive numerically solved reaction rate/kinetics model that takes into account the coupling between chemical equilibrium, mass transfer, and chemical kinetics of all possible chemical reactions for CO2 absorption into aqueous 4-diethylamino-2-butanol (DEAB) was successfully developed. The second order reaction rate constant of DEAB (k(2,DEAB)) was extracted from the model and can be expressed and ranked as: k(2,DEAB) = (4.01 x 10(13))exp(-7527.7/T) and PZ >> MEA >> DEAB similar to AMP similar to DEA>MDEA, respectively. The predicted CO2 absorption rates obtained from the developed reaction rate/kinetics model fit favourably with the experimental results with an AAD of 6.5%. In addition, k(2,DEAB) can also be simply predicted using a predictive correlation developed based on the Br phi nsted plot with an AAD of 7.6%. (C) 2012 Published by Elsevier Ltd.