Transient kinetics of n-butane oxidation to maleic anhydride over a VPO catalyst

Transient reaction kinetics is usually needed to model the reactor system operated under unsteady-state mode to improve the performance of the catalyst packed in such a reactor system and to match operating conditions of different reaction steps in this system. The transient reaction kinetics of n-butane oxidation to maleic anhydride over a commercial VPO catalyst was systematically studied, using online MS/GC measurements, transient response, and forced periodic operation methods. A simplified scheme with respect to the reaction network is proposed based on the previous studies and the observations in this work. Combining the results on the roles of lattice and adsorbed oxygen in the reaction process with the data obtained in transient response experiments, a transient kinetic model taking account of the oxygen storage and diffusion in the bulk-phase of the catalyst was introduced and its parameters were estimated. The model was examined by the transient response experimental data and time-average concentrations of butane and maleic anhydride under forced unsteady-state operation.