Cyclonic gas stripping deoiling and gas flow acceleration classification for the resource utilization of spent catalysts in residue hydrotreating process

Abstract The resource utilization of spent catalysts is one of the keys to enabling ebullated bed hydrotreating technology to be environmentally friendly, resource-saving and process sustainable. Spent residue hydrotreating catalysts contain a large amount of oil and highly active catalysts, if cannot be efficiently recycled will lead to waste of resources and huge catalyst consumption. In this study, the novel cyclonic gas stripping was first developed to spent catalysts deoiling, in which the removal of oil filled in the catalyst nanopores was enhanced by particle high speed self-rotation. Meanwhile, gas flow acceleration classification was developed for catalyst activity classification according to the particle density differences. This technology was successfully applied to the SINOPEC's first set of ebullated bed residue hydrotreating industrial demonstration unit, the total oil content of spent catalysts can reduce to 1.7% from 31.8%, with the deoiling efficiency reaching 96.7%. Moreover, 30% of the catalysts after deoiling were classified as highly active catalysts with lower particle density and higher pore volume. The successful implementation of this technology can reduce 25% of fresh catalyst consumption and 52% of hazardous waste discharge in residue hydrotreating process. This technique also can be extended to the resource utilization of spent catalysts in other petrochemical production.