FCC reactor with tube sheet separation

A process for the fluidized catalytic cracking (FCC) of an FCC feedstock, said process comprising:

• a) passing said FCC feedstock and regenerated catalyst particles to a reactor riser and transporting said catalyst and feedstock upwardly through said riser thereby converting said feedstock to product vapors and producing spent catalyst particles by the deposition of coke on said regenerated catalyst particles;
• b) discharging a first mixture of spent catalyst particles and product vapors from a discharge end of said riser upwardly into a dilute phase of a substantially closed disengaging zone at least partially contained within a reactor vessel;
• c) collecting catalyst in said disengaging zone and forming a dense bed of catalyst in said disengaging zone below said discharge end of said riser;
• d) passing a first stripping fluid stream into said disengaging zone and upwardly through said dense bed and stripping hydrocarbons from said catalyst in said dense bed and passing a first stripping effluent fluid upwardly from said dense bed into said dilute phase;
• e) maintaining a vapor seal between said disengaging zone and reactor vessel to restrict the flow of product vapors out of said disengaging zone;
• f) passing catalyst out said disengaging zone from said dense bed to a stripping zone and contacting catalyst in said stripping zone with a second stripping fluid stream, passing a second stripping effluent out of said stripping zone and withdrawing said second stripping effluent from said process;
• and,
• g) collecting a separated stream comprising catalyst particles, having a particle size ranging from 25 to 100 .mu.m said product vapors, and first stripping effluent from said dilute phase of said disengaging zone, said separated stream having a catalyst loading ranging from 0.05 to 0.2 lbs/ft.sup.3 and passing said separated stream to a separation chamber contained within said reaction vessel;
• h) dividing said separated stream in said separation chamber into a plurality of separator inlet streams and passing said separator inlet streams into a plurality of centrifugal separators each having an inlet in said chamber and an upper vapor outlet and a lower catalyst outlet communication with the outside of said chamber;
• i) dropping catalyst from the catalyst outlets of said centrifugal separators into said stripping zone;
• and,
• j) collecting a vapor product stream from the vapor outlets of said centrifugal separators and recovering said product stream from said process.