The role of catalyst activity on the steady state and transient behavior of an industrial-scale fixed bed catalytic reactor for the partial oxidation of o-xylene on V2O5/TiO2 catalysts

Steady state and transient observations in industrial-scale fixed-bed catalytic reactors for the partial oxidation of o-xylene on V2O5/TiO2 catalysts, and in general for most of the partial oxidation of hydrocarbons on mixed-oxide catalysts, have not been predicted satisfactorily to date, because two aspects that need to be considered are missing: (1) the proper account of the hydrodynamics on heat transport in the packed bed, and (2) the kinetics of catalytic and deactivation reactions, that have not been accounted for adequately into the reactor model. Our previous papers [Ind. Eng. Chem. Res. 46(23) (2007) 7426–7435, Ind. Eng. Chem. Res. 49 (2010) 6845–6853] have already analyzed the role of hydrodynamics on the heat transport processes in the packed bed. In the present study a redox-based reaction kinetics incorporates the catalyst deactivation by considering the redox dynamics of the catalyst together with a superimposed (empirical) activity profile. Then the model is tested in the prediction of temperature and yield measurements in an industrial-scale fixed-bed catalytic reactor during steady state and transient operations.

► Oxidation of o-X to phthalic PA has been of academic and industrial interest.
► V2O5/TiO2 catalysts have also been the subject of several reviews.
► A redox-based mechanism is used to describe the kinetics of this reaction.
► It improves the prediction of temperature and composition profiles.