Abstract: Investigation on the deactivation and reactivation of precious metal hydrogenation catalyst was carried out on a high pressure fixed bed micro-reactor with simulating industrial conditions. Test results showed that when processing feed containing quadrol for 3 days, the activity of the catalyst dropped rapidly and qualified food grade white oil could not be produced. With the increase of test time, the aromatics saturation function of the catalyst reduced, indicating that nitrogen was gradually accumulated on the catalyst. After substituting by clean feed, the activity of the deactivated catalyst was recovered partially though it was not ready for the production of food grade white oil, which indicated that the nitrogen deactivation was irreversible in a way. In-situ reduction with hydrogen could further recover the aromatics saturation function of the deactivated catalyst, but the reactivated catalyst was still not good enough for food grade white oil production. Therefore, in order to prolong the service life of precious metal hydrogenation catalyst in commercial units, it is important to keep the nitrogen content of the feed low.

Key words: noble metal, catalyst, nitrogen, poisoning, white oil, activity