An investigation of the kinetic parameters of the o-xylene oxidation process carried out in a fixed bed of high-productive vanadia-titania catalyst

The behavior of a reactor of a fixed bed composed by high-productive V2O5-TiO2 (anatase) supported catalysts for oxidation of o-xylene into phthalic anhydride is theoretically and experimentally investigated. A two-dimensional heterogeneous mathematical model, as well as experiments obtained in an industrial multitube fixed bed reactor, is used. The kinetic parameters in the kinetic relations suggested by Calderbank et al. (Chem. Eng. Sci. 32 (1977) 1435) for description of the oxidation process are corrected in a proper way. New formal values of the parameters mentioned are determined. They interpret well the temperature regime and the yields of phthalic anhydride and the main side product (phthalide) obtained in the industrial reactor during the initial periods of the catalyst life. (C) 2002 Elsevier Science Ltd. All rights reserved.