Jointly published by React.Kinet.Catal.Lett. Akadémiai Kiadó, Budapest Vol. 82, No. 2, 363-369 and Kluwer Academic Publishers, Dordrecht (2004) 0133-1736/2004/US$ 20.00. © Akadémiai Kiadó, Budapest. All rights reserved. RKCL4526 KINETICS OF CARBON DIOXIDE SORPTION BY THE COMPOSITE MATERIAL K 2 CO 3 IN Al 2 O 3 Vasily E. Sharonov * , Alexey G. Okunev and Yury I. Aristov Boreskov Institute of Catalysis, Novosibirsk 630090, Russia Received March 8, 2204 Accepted March 12, 2004 Abstract The kinetics of the CO 2 sorption by a composite sorbent K 2 CO 3 in Al 2 O 3 was studied in a gradientless adsorber at 295 K. The order of the sorption rate with respect to the CO 2 concentration was found to be n = 1.04 ± 0.07. The sorption rate constants were evaluated for sorbent grains of various sizes between 0.25 and 2.1 mm. It was shown that the rate constant is proportional to the grain reciprocal radius. The dynamic capacity was obtained as a function of the CO 2 concentration. The maximum sorption capacity was found to be 83 mg of CO 2 per 1 g of the sorbent. Keywords: Sorption kinetics, carbon dioxide, potassium carbonate, alumina, gradientless adsorber INTRODUCTION Recently, several reports [1-4] on new CO 2 composite sorbents based on K 2 CO 3 introduced into a porous matrix (silica, alumina, carbons, etc.) have appeared. The CO 2 capture was shown to occur owing to the reversible reaction K 2 CO 3 2 O + CO 2 = 2 KHCO 3 2 These sorbents revealed a high CO 2 sorption capacity within the temperature interval 20–100°C and thus can be viewed as promising materials, which can replace conventional zeolites currently used for the CO 2 removal from wet gases. Furthermore, a high dispersity of confined K 2 CO 3 leads to a high CO 2 sorption rate. Numerous data are reported on the kinetics of CO 2 adsorption on _________________________ *Corresponding author. E-mail: sharonov@catalysis.nsk.su