Abstract: Coke and silicon deposition has a great but different influence on the activity of hydrotreating catalyst and regenerated catalyst. The properties of the catalysts after deactivation and regeneration were characterized by TG-DSC, Raman spectroscopy, N2 adsorption-desorption, TPR and SEM-EDS techniques. It is found that the sulfur and carbon compounds is easy to decompose on the deactivated catalyst caused by carbon deposition, the pore structure can be restored close to 90% of fresh catalyst, while the pore structure of deactivated catalyst caused by deposition of silicon has a great loss, and large particles of MoS2 as well as the graphitized carbon appears. TPR tests show that the interaction between the metal and the carrier increases after silicon deposition, resulting in higher reduction temperature and difficult to be sulfided completely. The results of activity evaluation show that the activity of coke-deactivated catalyst can be recovered after regeneration, while the activity of silicon-deactivated catalyst is much poor.

Key words: hydrotreating catalyst, coking, silicon deposition, deactivation, regeneration