Catalyst recovery from light olefin FCC effluent

摘要

A method and system for recovering fines from a light FCC-type effluent gas. Cracked gases from the reactor are cooled by direct contact with circulating oil in an oil quench tower. The circulating oil also washes out the catalyst fines carried with the reactor effluent gas. A flow of the oil from the quench tower bottoms is sent through one of a pair of filters to remove fines and recycled to the tower. The other filter is in backwash operation using a compressed gas to remove the fines therefrom and into a surge drum. Fuel oil or quench oil is added to the drum to form a slurry, which carries the catalyst fines to the regenerator where the oil is combusted to supply the FCC system heat requirements. Since a minimum amount of fuel oil is generated in the FCC, fuel oil is imported to inventory the quench tower.