US 5,314,611 A · External integrated disengager stripper and its use in fluidized catalytic cracking process

Abstract

A method and apparatus for an FCC process uses dissipator plates at the outlet of a disengaging vessel to provide a quick separation of catalyst from product vapors and to prevent reentrainment of catalyst into the disengaging vessel. The process and apparatus use a riser for the conversion of an FCC feedstock and direct the effluent from the riser directly into a disengaging vessel to separate catalyst from the product vapors. Catalyst is directed downwardly out of the outlet of the disengaging vessel and through a series of dissipator plates that eliminate the tangential velocity that would be otherwise introduced by the vortex and would lead to reentrainment of catalyst. A stripping vessel is located immediately below the disengaging vessel outlet to receive catalyst as it leaves the dissipator plates. The apparatus and process are specifically suited for operation without a reactor vessel for containment of the disengaging vessel and cyclones.

Claims24

Dependent claims

A fluid catalytic cracking apparatus comprising:

(a) a tubular riser having an inlet end for receiving feed and catalyst and an outlet end;
(b) an elongated disengaging vessel having an upper end and a lower end, means for tangentially directing the outlet end of said riser into an upper end of said disengaging vessel, and a gas outlet at the top of said disengaging vessel, said lower end of said disengaging vessel having an open bottom wherein the outermost portion of said open bottom is unoccluded to permit unobstructed fluid and particulate flow;
(c) a stripping vessel located directly below said disengaging vessel, said stripping vessel having an inlet in open communication with said open bottom of said disengaging vessel and an outlet for withdrawing catalyst from the stripping vessel;
(d) means for adding stripping gas to said stripping vessel;
and,
(f) a segregation zone located in said stripping vessel comprising means for dissipating turbulent flow below said open bottom of said disengaging vessel.

3 more elements

A fluid catalytic cracking apparatus comprising:

(a) a tubular riser having an inlet end for receiving feed and catalyst and an outlet end;
(b) an elongated disengaging vessel having an upper end and a lower end, said upper end having a tangential inlet in direct communication with said outlet end of said riser and a central gas outlet at the top of said disengaging vessel and said lower end having a vertically extending sidewall and an open bottom;
(c) a stripper vessel having an upper end into which said lower end of said disengaging vessel extends, at least two dissipator plates extending inwardly from the walls of said stripper vessel with each dissipator plate lying in a common plane with the centerline of said stripper vessel, said dissipator plates having a central portion, with the top of said central portion spaced below said lower end of said disengaging vessel, a catalyst outlet in the lower end of said stripper vessel, at least one inner stripping baffle and at least one outer stripping baffle located between the top of said central portion of said dissipator plates and said catalyst outlet, and means for introducing a stripping fluid into said stripping vessel;
(d) a vortex stabilizer extending into the lower end of said disengaging vessel;
and,
(e) a transfer conduit communicating said gas outlet with a cyclone separator, said cyclone separator having a dip-leg that returns catalyst from said cyclone separator to said stripping vessel.

3 more elements

A fluid catalytic cracking apparatus comprising:

(a) a tubular riser having an inlet end for receiving feed and catalyst and an outlet end;
(b) an elongated disengaging vessel having an upper end and a lower end, said upper end having a tangential inlet in direct communication with said outlet end of said riser and a central gas outlet at the top of said disengaging vessel and said lower end having a vertically extending sidewall, an open bottom and a plurality of circumferentially spaced slots bordering the bottom of said vertically extending sidewall;
(c) a stripper vessel having an upper section fixed to the lower end of said disengaging vessel, said stripping vessel including;
(i) a larger diameter than the lower end of said disengaging vessel, at least two levels of stripping baffles, and at least two dissipator plates extending inwardly from the walls of said stripper vessel with each dissipator plate lying in a common plane with the centerline of said stripper vessel, said dissipator plates having a central portion that extends past the outside of said open bottom of said disengaging vessel with the top of said central portion spaced below said lower end of said disengaging vessel and an outer portion that extends vertically from the top of said central portion above said open bottom of said disengaging vessel, and at least one stripping baffle located at the bottom of said dissipator plates;
(ii) a lower section of said stripping vessel having a catalyst outlet and a distributor for adding stripping gas to said stripper vessel;
and,
(iii) a vortex stabilizer extending into the lower end of said disengaging vessel;
(d) a cyclone separator for receiving product vapors and catalyst from said gas outlet, said cyclone having a dip-leg that returns catalyst to said upper section of said stripping vessel;
(e) a first conduit communicating product vapors directly from said gas outlet to said cyclone separator;
and,
(f) a second conduit for communicating product vapors from said cyclone and to product recovery facilities.

8 more elements

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

(a) passing FCC catalyst and said FCC feedstream to a riser reaction zone and contacting said feedstream with said FCC catalyst in said riser reaction zone to convert said feedstream to product vapors;
(b) discharging a mixture of said product vapors and spent FCC catalyst from said riser directly into a disengaging vessel and directing said mixture tangentially into said disengaging vessel to form at least an outer vortex in said disengaging vessel;
(c) emptying catalyst particles in closed communication from the bottom of said disengaging vessel directly into the top of a subadjacent stripping vessel;
(d) injecting a stripping gas into said stripping vessel and contacting said catalyst particles with said stripping gas to desorb hydrocarbons from said catalyst particles;
(e) discharging a gaseous stream of desorbed hydrocarbons and stripping gas upwardly from said stripping vessel, dissipating the turbulent flow of fluid and catalyst particles at the top of said stripping vessel, and passing said desorbed hydrocarbons and stripping gas out of the top of said stripping vessel and into the bottom of said disengaging vessel;
(f) maintaining a relatively dense bed of catalyst below the top of said stripping vessel;
(g) withdrawing said product vapors and said gaseous stream from the top of said disengaging vessel through an outlet;
(h) passing said product vapor and said gaseous stream from said outlet to a separator to recover additional catalyst particles;
(i) recovering a product stream from said separator;
(j) transferring catalyst particles from said separator to said stripping vessel;
(k) removing spent FCC catalyst from the lower end of said stripping vessel and transferring said spent catalyst to a regeneration zone;
(l) regenerating said FCC catalyst in said regeneration zone by the oxidative removal of coke;
and,
(m) transferring FCC catalyst from said regeneration zone to said riser reaction zone.

11 more elements

Dependencies are inferred from the claim text.

External integrated disengager stripper and its use in fluidized catalytic cracking process

Life of this patent

External integrated disengager stripper and its use in fluidized catalytic cracking process

Life of this patent

Abstract

Claims24