Characterization and Catalytic Performance of Deactivated and Regenerated TS-1 Extrudates in a Pilot Plant of Propene Epoxidation

Abstract

TS-1 extrudates that were used for propene epoxidation in a pilot plant for about 1700 h deactivated partly. To study the reason for the deactivation, the deactivated and regenerated catalysts were investigated with X-ray diffraction analysis, Fourier-transform infrared, Ultraviolet–visible diffuse reflectance, thermogravimetry–differential thermogravimetry, N2 sorption, n-hexane adsorption, cyclohexane adsorption, and elemental analysis. The catalytic performance of the deactivated and regenerated TS-1 extrudates in the epoxidation of propene was evaluated in a fixed-bed reactor and in a batch reactor. The activity of the deactivated catalyst from the inlet of the pilot-plant reactor was higher than that from the outlet of the reactor in which more propene oxide oligomers were generated than in the pores of catalyst taken from the inlet of the reactor. External and in situ regeneration could reinstate the activity of the deactivated catalysts, while the in situ regeneration was preferred.