FCC process with secondary conversion zone

A process for the fluidized catalytic cracking (FCC) of an FCC feedstock and conversion of a secondary feedstream, 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 a riser gaseous product stream and producing partially spent catalyst particles by the deposition of coke on said regenerated catalyst particles;
• b) discharging a mixture of partially spent catalyst particles and riser gaseous products from a discharge end of said riser in an upward direction into a substantially closed disengaging vessel contained in a reactor vessel;
• c) passing separated catalyst downward through said disengaging vessel and collecting catalyst in a first dense catalyst bed contained within said disengaging vessel and contacting said catalyst with a stripping medium in said first dense bed;
• d) discharging partially spent catalyst out of the bottom of said disengaging vessel through a restricted flow opening;
• e) passing said partially spent catalyst downward from said disengaging vessel into said reactor vessel and maintaining a second dense catalyst bed in said reactor vessel and introducing a secondary feedstock into said second dense catalyst bed;
• f) contacting said partially spent catalyst with said secondary feedstock in said dense bed to produce a reactor vessel product stream;
• g) passing spent catalyst from said reactor vessel downward through a subadjacent stripping vessel and passing a stripping medium upwardly through said stripping vessel countercurrently to the flow of said catalyst;
• h) withdrawing stripped catalyst from said stripping vessel and passing stripped catalyst from said stripping vessel into a regeneration zone and contacting said stripped catalyst with a regeneration gas in said regeneration zone to combust coke from said catalyst particles and produce regenerated catalyst particles for transfer to said reactor riser;
• i) withdrawing said riser gaseous products from said disengaging vessel and removing said riser product stream from said disengaging vessel through a first outlet;
• and,
• j) withdrawing said reactor vessel product and stripping medium from said reactor vessel through a second outlet.

A process for the fluidized catalytic cracking (FCC) of an FCC feedstock and conversion of a secondary 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 a gaseous product stream and producing spent catalyst particles by the deposition of coke on said regenerated catalyst particles;
• b) discharging a mixture of partially spent catalyst particles and riser gaseous products from a discharge end of said riser in an upward direction into a disengaging vessel contained in a reactor vessel, said disengaging vessel having substantially closed sidewalls and a substantially closed top, thereby providing an initial separation of the spent catalyst from the gaseous products;
• c) passing separated catalyst downward through said disengaging vessel and collecting catalyst in a first dense catalyst bed located in said disengaging vessel;
• d) passing a first stripping medium into a lower section of said disengaging vessel and passing said stripping medium countercurrently through said dense bed to riser gaseous products from said catalyst and producing a first stripping fluid comprising stripping medium and riser gaseous products;
• e) discharging at least 90 wt. % of said partially spent catalyst out of the bottom of said disengaging vessel through a sealing device;
• f) passing said spent catalyst downward from said sealing device into a second dense catalyst bed maintained in the bottom of said reactor vessel and charging a secondary feedstream to said second dense catalyst bed;
• g) contacting said secondary feedstream with said partially spent catalyst in said second dense catalyst bed to produce a reactor vessel product;
• h) passing catalyst from said second dense catalyst bed into a subadjacent stripping vessel, said stripping vessel having open communication with a lower end of said reactor vessel, countercurrently contacting said spent catalyst with a second stripping medium in said dense catalyst bed and upwardly discharging a second stripping fluid comprising stripping medium and said reactor vessel product from said stripping zone;
• i) passing spent catalyst from said subadjacent stripping vessel into a regeneration zone and contacting said spent catalyst with a regeneration gas in said regeneration zone to combust coke from said catalyst particles and produce regenerated catalyst particles for transfer to said reactor riser;
• j) collecting a first effluent stream comprising said first stripping fluid in an annular chamber located in said disengaging vessel, said annular chamber surrounding the end of the said riser and having a substantially closed bottom and an open top located below the discharge end of said riser;
• k) transferring said first effluent stream in an enclosed conduit from said annular chamber to a cyclone separator located in said reactor vessel outside of the disengager vessel and separating entrained catalyst from said effluent stream;
• l) discharging separated catalyst from said cyclone separator into said second stripping zone;
• m) recovering said first effluent from said cyclone separator through a first outlet;
• and,
• n) withdrawing said second stripping fluid from said the open volume of said reactor vessel as a second effluent through a second outlet.