Abstract: Spent hydrocracking pretreating catalyst was regenerated under control temperatures; the well regenerated catalysts were further treated with suitable assistant agents under post-processing conditions to obtain reactivated catalysts. Catalysts prior and post to reactivation were characterized by means of nitrogen adsorption, X-ray diffraction, transmission electron microscopy and X-ray photoelectron spectroscopy, as well as evaluation of catalytic activity. Results showed that with the increase of regeneration temperature, the pore structure of the catalyst restored gradually and the number of small pores (less than 4 nm) decreased. The post-processing of regenerated catalyst could improve the catalyst pore structure significantly, help the active components well disperse on the catalyst surface and promote the active metals to be sulfurized, thus the activity of the reactivated catalyst was even higher than that of the fresh catalyst.

Key words: hydrotreating catalyst, reneneration, reactivation, post-processing