In this work, the kinetic, of the reaction between CO2 and aqueous piperazine (PZ) have been estimated over the temperature range of 298-313 K from the absorption data obtained in a wetted wall contactor. The absorption data are obtained for the PZ concentrations of 0.2-0.8 kmol m(-3) and for CO2 partial pressures up to 5 kPa. A coupled mass transfer-kinetics-equilibrium, mathematical model based on Higbie's penetration theory has been developed with the assumption that all reactions are reversible. The model is used to estimate the rate constants from the experimental data for absorption of CO2 in aqueous PZ. The estimated rate constants of this study are in good agreement with those reported in the literature. (C) 2007 Published by Elsevier Ltd.