The ethylene oxide hydration process in a catalytic fixed-bed tube reactor was studied. A cross-linked styrene-divinylbenzene anion-exchange resin in the HCO3-/CO32- form was used as a catalyst. The deactivation and swelling of the catalyst during the process was detected. The mathematical model of the reactor with determined parameters adequately describing the rate of the reaction, product distribution and catalyst deactivation and swelling has been developed. (c) 2004 Elsevier B.V. All rights reserved.