Abstract: Spent or inactive alumina-supported catalysts removed from a catalytic hydrotreating process and having carbonaceous and metallic deposits thereon are reactivated. After a solvent wash to remove process oils, the spent catalyst is contacted with steam at a temperature of 1000.degree. to about 1250.degree. F. for a period of about 2 to about 5 hours to form a reactivated catalyst suitable for reuse in a catalytic hydrotreating process. Optionally, the steam-treated catalyst can be regenerated by contact with an oxygen-containing gas at a temperature of about 700.degree. to about 900.degree. F. to remove carbon deposits from the catalyst, or, alternatively, the steam-treated catalyst can be acid-leached to remove undesired metals and then contacted with an oxygen-containing gas at an elevated temperature to remove carbon deposits.

Abstract: Spent or inactive alumina-supported catalysts removed from a catalytic hydrotreating process and having carbonaceous and metallic deposits thereon are reactivated. After a solvent wash to remove process oils, the spent catalyst is contacted with steam at a temperature of 1000.degree. to about 1250.degree. F. for a period of about 2 to about 5 hours to form a reactivated catalyst suitable for reuse in a catalytic hydrotreating process. Optionally, the steam-treated catalyst can be regenerated by contact with an oxygen-containing gas at a temperature of about 700.degree. to about 900.degree. F. to remove carbon deposits from the catalyst, or, alternatively, the steam-treated catalyst can be acid-leached to remove undesired metals and then contacted with an oxygen-containing gas at an elevated temperature to remove carbon deposits.

Abstract: Spent hydrotreating catalyst having carbonaceous and metallic deposits and of regular geometric shape after being stripped of process oil is fluidized by flowing air upwardly through the catalyst at a velocity sufficient to expand the bed thereby segregating the catalyst particles into a high activity, upper, less-contaminated fraction and a lower, more-contaminated fraction and recycling the high activity fraction to a hydrotreating process. Optionally, the high activity fraction can be regenerated with carbon burnoff or rejuvenated by acid leaching followed by regeneration with carbon burnoff to further improve catalyst activity.