Carbon dioxide sorption rate parameters and sorption capacities on two different regenerable sorbents, namely hydrotalcite and activated trona, were investigated in a fixed bed flow adsorber, in the temperature range of 400-527 degrees C and 80-152 degrees C, respectively. Hydrotalcite, which was activated at 550 degrees C, was shown to give total and breakthrough CO2 sorption capacities as high as 1.16 and 0.70 mmol/g, respectively, at 452 degrees C, in the absence of water vapor. In the presence of excess water vapor, the total CO2 Sorption capacity was not affected much, however a decrease in the breakthrough capacity and on the sorption rate constant was observed, especially at lower temperatures. In the presence of water vapor, activated trona was shown to give comparable total and breakthrough CO2 sorption capacities, at much lower temperatures (T < 100 degrees C). The deactivation model gave good predictions of the CO2 breakthrough curves and it was successfully used for the evaluation of the adsorption and the deactivation rate constants. (c) 2006 Elsevier B.V. All rights reserved.