Continuous developments of catalyst off-site regenerationand presulfiding

Abstract This paper presents the insight of ex-situ regeneration and ex-situ presulfiding of hydroprocessing catalysts. The ex-situ regeneration of used hydroprocessing catalysts offers a better performance recovery because of the precise temperature control. During the oxidation step, carbon and sulfur removals are optimized to get a maximum surface area and oxygen chemisorption capacity recovery, this last parameter being related to active sulfide phase dispersion. The ex-situ presulfided catalysts having an oxysulfide form of active metals can be converted into a sulfided form during the activation stage in a hydroprocessing reactor, providing a quick and convenient start-up of the commercial units.