PROCESS AND APPARATUS FOR MIXING FLUID CATALYTIC CRACKING HYDROCARBON FEED AND CATALYST

摘要

A process and apparatus for mixing fluid catalytic cracking hydrocarbon feed and catalyst is disclosed. Lift gas passes through a first conduit which is axially aligned with a second conduit. A downstream end of the first conduit and an upstream end of the second conduit are located within a catalyst bed enclosed by a chamber. The second conduit axially injects catalyst and lift gas into an upstream end of an elongated fluid catalytic cracking riser while passing hydrocarbon feed into the riser through an annular zone about the upstream end of the riser. Preferably steam also passes through this annular zone. The process and apparatus achieves substantially uniform catalyst-to-oil ratio across a horizontal cross-section of the riser. A process and apparatus for control of the level of the catalyst bed in the enclosed chamber by employing a control gas stream is also disclosed.