Process and apparatus for separating a catalyst from a product gas

Abstract

A process and apparatus for the catalytic conversion of a feedstock and separation of the catalyst from the product gas includes contacting a first hydrocarbon feedstock with a first catalyst stream in a first riser to produce a first mixture of catalyst and product gas. A second hydrocarbon feedstock is contacted with a second catalyst stream in a second riser to produce a second mixture of catalyst and product gas. The first riser and / or the second riser may terminate within a reaction vessel. The first mixture of catalyst and product gas from the first riser enters a first liberation chamber within the reaction vessel. The second mixture of catalyst and product gas from the second riser enters a second liberation chamber within the same reaction vessel.

Description

Technical Field

[0001] (Priority Claim) This application claims priority to U.S. Provisional Patent Application No. 63 / 389,345, filed on July 14, 2022, the entire content of which is incorporated herein by reference.

[0002] (Field of the Invention) The technical field is the reaction of feedstock and a fluid catalyst. Specifically, the technical field relates to separating product gas from a fluid catalyst.

Background Art

[0003] The cyclone method for separating solids from gases is well-known and commonly used in fluid catalytic processes. A particularly well-known application of such a method is in the hydrocarbon processing industry where particulate catalysts contact gaseous reactants to effect chemical conversion of the gas stream components or physical changes of the particles in contact with the gas stream.

[0004] Among fluid catalytic processes, the FCC process presents a well-known example of a process that uses a gas stream to contact a finely divided stream of catalyst particles and effect catalytic conversion of the gas stream in contact with the particles.

[0005] Efficiently separating particulate catalyst from product vapor is very important in the FCC process. Particulate catalyst that is not efficiently separated from product vapor in an FCC unit must be separated downstream either by filtration or by additional separation devices that increase the separation devices utilized in the FCC unit. Furthermore, catalyst that is not recovered from the FCC process represents a double loss. The catalyst requires replacement and represents a material cost. Also, unrecovered catalyst can erode downstream equipment. Severe erosion can cause equipment failure and subsequent loss of production time. Therefore, a method for efficiently separating particulate catalyst material from a gaseous fluid in the FCC process is very useful.

[0006] In the FCC process, the product gas is separated from the particulate catalyst solids upon discharge from the reaction conduit. The most common method of separating particulate solids from the gas stream is to use centrifugal separation. A centrifugal separator operates by imparting a tangential velocity to the gas containing entrained solid particles, and this tangential velocity pushes the heavier solid particles outward and away from the lighter gas in order to pull the gas upward and collect the solids downward.

[0007] The apparatus for the initial rapid centrifugal separation discharges the mixture of product gas and solid catalyst tangentially from the riser into a disengagement vessel. The disengagement vessel effects a first separation of the solids from the gas. In these apparatuses, after the initial stage of separation, typically a second more competitive separation of the solids from the gas in a conventional cyclone apparatus follows.

[0008] Another way to obtain this initial rapid separation involves discharging the product gas from the riser through an arcuate tubular vortex duct that imparts a swirling helical motion to the product gas and granular catalyst as they enter the disengagement vessel. The swirling helical motion of the substances in the disengagement vessel effects an initial separation of the particulate catalyst from the gas. The product gas containing a small amount of entrained catalyst rises through a gas recovery conduit and is drawn into a cyclone to further separate the particulate catalyst from the product gas.

[0009] A cyclone typically has an inlet that is tangential to the outside of a cylindrical container that forms the outer wall of the cyclone. In the operation of an FCC cyclone, the inlet and the inner surface of the outer wall cooperate to form a helical flow path for the gaseous substance and catalyst that establishes a vortex within the cyclone. The centripetal acceleration associated with the outside of the vortex moves the catalyst particles toward the outside of the barrel while the gaseous substance enters the inside of the vortex and is finally discharged through an upper outlet. The heavier catalyst particles accumulate on the side wall of the cyclone barrel and finally fall to the bottom of the cyclone and exit through an outlet and a dip leg conduit to recirculate through the FCC unit.

[0010] U.S. Patent Application Publication No. 20150005553 (A1) provides a release device that can accommodate the effluent of two or more reactors or other sources of solid particles mixed with gas to cause separation.

[0011] There is a need for a single separation process and apparatus that can accommodate two or more distinct streams of product gas and solid catalyst particles. SUMMARY OF THE INVENTION

[0012] The present disclosure relates to processes and apparatuses for the catalytic conversion of feedstock and the separation of catalyst from product gas. A first hydrocarbon feedstock contacts a first catalyst stream in a first riser to produce a first mixture of catalyst and product gas. A second hydrocarbon feedstock contacts a second catalyst stream in a second riser to produce a second mixture of catalyst and product gas. The first riser and / or the second riser may terminate within a reaction vessel. The first mixture of catalyst and product gas from the first riser enters a first release chamber within the reaction vessel. The second mixture of catalyst and product gas from the second riser enters a second release chamber within the same reaction vessel.

[0013] Further details and embodiments of the present invention will become apparent from the following detailed description of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0014]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

[0015] DEFINITIONS The term "downstream communication" means that at least a portion of the fluid flowing to the object in downstream communication can flow operably from the object in fluid communication.

[0016] The term "upstream communication" means that at least a portion of the fluid flowing from the object in upstream communication can flow operably to the object in fluid communication.

[0017] The term "direct communication" means that the flow of fluid from the upstream component enters the downstream component without passing through any other intervening container.

[0018] The term "indirect communication" means that the flow of fluid from the upstream component enters the downstream component after passing through an intervening container.

[0019] The term "bypass" means that the object is out of downstream communication with the bypass target to at least the extent of bypassing.

[0020] As used herein, the term "predominant" or "predominant" means more than 50%, preferably more than 75%, more preferably more than 90%.

[0021] As used herein, the term "tangential direction" means in the tangential direction or substantially tangential direction, but not in the radial direction.

DETAILED DESCRIPTION OF THE INVENTION

[0022] Referring to FIG. 1, this schematic diagram shows a release device within the reaction vessel 10. The first reactor riser 12 extends upward from the lower part of the reaction vessel 10 within the FCC unit. The first riser 12 preferably has a vertical orientation within the reaction vessel 10 and can extend upward from the bottom of the reaction vessel, i.e., downward from the top of the reaction vessel.

[0023] The first hydrocarbon feedstock is distributed into the first riser 12 from one or more feedstock distributors 13 near the base of the riser. The first catalyst stream can be fluidized by the steam distributed from the distributor 18 at the bottom of the first riser 12. The first hydrocarbon feedstock contacts the first catalyst stream within the first riser 12. The first catalyst stream can be provided by a mixture of a first high-temperature catalyst stream from the first high-temperature catalyst tube 20 and a first recycle catalyst stream from the first recycle catalyst tube 22. The first hydrocarbon feedstock vaporizes and is converted to a product gas containing hydrocarbons with a lower molecular weight than the feedstock or is decomposed. Due to molar expansion and evaporation, the first hydrocarbon feedstock and the product gas accompany the first catalyst stream as a first mixture of the catalyst and the product gas and rapidly ascend the riser 12.

[0024] The first riser 12 terminates at the upper end of a first release chamber 11 located within the reaction vessel 10 in a curved tube 14 or a plurality of tubes. As best shown in FIG. 2, the one or more curved tubes 14 include a first outlet 16 contained in the first release chamber 11. The first riser 12 is longitudinally positioned at the center of the first release chamber 11. The first outlet 16 centrifugally discharges the first mixture of the product gas and the catalyst into the first release chamber 11. Due to the centrifugal discharge, the first mixture is discharged from the inside to the outside.

[0025] The centrifugal discharge of gas and catalyst from the first discharge port 16 generates a spiral pattern inside the first release chamber 11 below the first discharge port 16. The centrifugal acceleration associated with the spiral motion pushes the heavier catalyst particles towards the wall 17 of the first release chamber 11 during the upward movement of the product gas. The wall 17 of the first release chamber 11 can be cylindrical. By the dynamic action, the first mixture of catalyst and product gas is released into the first product gas stream and the first released catalyst stream within the first release chamber 11. The first released catalyst stream from the discharge port 16 exits through the first lower outlet 19 of the first release chamber 11 and accumulates in the high-concentration catalyst bed 28 at the bottom and below the first release chamber 11. The first product gas stream passes upward through the first upper outlet 24 and is discharged from the first release chamber 11. In another embodiment, the first release chamber 11 may not use a centrifugal separator, but a gravity separator or an inertial separator such as a ballistic separator may be used. The wall 17 of the first release chamber 11 does not necessarily have to be cylindrical.

[0026] A separate second reactor riser 50 extends outside the reaction vessel 10. The second mixture of product gas and catalyst passes through the second riser 50 and reaches the upper end 46 of the second riser 50. The upper end 46 transitions at a 90° elbow to provide a substantially horizontal transfer conduit 48. The transfer conduit 48 intersects the wall 15 of the reaction vessel 10 and the wall 63 of the second release chamber 60. The wall of the reaction vessel 10 and the wall 63 of the second release chamber 60 can be cylindrical.

[0027] The second hydrocarbon feedstock is distributed into the second riser 50 from one or more feedstock distributors 53 near the base of the second riser. The second catalyst stream can be fluidized by the steam distributed from the distributor 58 at the bottom of the second riser 50. A steam flow rate of 5 wt% to 25 wt% of the second hydrocarbon stream can be added to the second riser 50. The second hydrocarbon feedstock contacts the second catalyst stream within the second riser 50. The second catalyst stream can be provided by a mixture of a second high-temperature catalyst stream from the second high-temperature catalyst tube 62 and a second recirculation catalyst stream from the second recirculation catalyst tube 71. The second hydrocarbon feedstock vaporizes and is converted into a product gas containing hydrocarbons with a lower molecular weight than the feedstock or decomposed. Due to molar expansion and evaporation, the second hydrocarbon feedstock and the product gas rapidly rise through the second riser 50 accompanying the second catalyst stream as a second mixture of the catalyst and the product gas. The second catalyst stream can contain 0.005 wt% to 1.2 wt% of coke.

[0028] The second riser 50 terminates at the upper end of a second release chamber 60 located within the reaction vessel 10 in the horizontal transfer conduit 48. The horizontal transfer conduit 48 includes a second discharge port 49 contained within the second release chamber 60. In one embodiment, the horizontal transfer line 48 of the second riser 50 terminates at the second release chamber 60. The second discharge port 49 discharges the second mixture of the product gas and the catalyst tangentially into the second release chamber 60. In other embodiments, the horizontal transfer line 48 can be replaced with alternative connectors such as more acute or more obtuse T-shaped connectors or elbows. The eccentric scroll of the discharge inlet 49 of the transfer conduit 48 can be from 0 degrees to 180 degrees. The aspect ratio of the discharge inlet 49 can be from 0.1 to 10 and can have a rectangular cross-sectional shape. The wall 63 of the second release chamber 60 can be 1 to 5 times the height of the discharge port below the discharge port 49.

[0029] As best seen in FIG. 2, the horizontal transfer line 48 enters the reaction vessel 10 through the wall 15 and then tangentially enters the wall 63 of the second release chamber 60 at the second outlet 49. The second outlet 49 is located in the wall 63 of the second release chamber 60. The tangential discharge of the second mixture of catalyst and product gas through the second outlet 49 from the second riser 50 generates a spiral vortex pattern around the inside of the second release chamber 60. The second outlet 49 and the transfer line 48 can be tangential or substantially tangential to the wall 63 of the second release chamber 60, but not radial. The liberation of the first mixture of catalyst and product gas into the first product gas stream and the first liberated catalyst stream is carried out concentrically inside the liberation of the second mixture of catalyst and product gas into the second product gas stream and the second liberated catalyst stream.

[0030] The wall 17 of the first release chamber 11 functions as the outer wall of the first release chamber 11 and also as the inner wall of the second release chamber 60. The second release chamber 60 is a ring that surrounds the first release chamber 11 and / or is annular with respect to the first release chamber 11. Wear-resistant linings or coatings are provided on both sides of the wall 17 of the first release chamber 11 and inside the wall 63 of the second release chamber 60 to protect the metal from wear due to the movement of the catalyst.

[0031] Generally, the cross-sectional area of the second outlet 49 can be smaller than or equal to the cross-sectional area of the upper end 46 of the second riser 50. The upper end 46 of the second riser 50 can be from 0.3 meters (1 foot) to 2.74 meters (9 feet) in diameter. Preferably, the upper end of the reactor riser 50 can be from 0.91 meters (3 feet) to 2.1 meters (7 feet) in diameter.

[0032] The product gas discharged from the second discharge port 49 and the vortical spiral pattern followed by the catalyst can follow a vortex in the same direction as the substance from the first riser. The centripetal acceleration associated with the spiral motion pushes the heavier catalyst particles towards the wall 63 of the second release chamber 60 while the product gas easily changes direction and rises. By the dynamic action, a second mixture of catalyst and product gas is released into a second product gas stream and a second released catalyst stream within the second release chamber 60. The release of the second mixture of catalyst and product gas within the second release chamber 60 is carried out separately from the release of the first mixture of catalyst and product gas within the first release chamber 11.

[0033] Returning to FIG. 1, the second released catalyst stream from the second discharge port 49 exits through the second lower outlet 67 of the second release chamber 60 and collects in the high-concentration catalyst bed 28 at the bottom and below the second release chamber 60. The first lower outlet 19 of the first release chamber 11 is located adjacent to the second lower outlet 67 of the second release chamber 60 at the lower end of the reaction vessel 10. The second lower outlet 67 of the second release chamber 60 is annular with respect to the first lower outlet 19 of the first release chamber 11. The first released catalyst stream from the first release chamber 11 and the second released catalyst stream from the second release chamber 60 are mixed in the high-concentration catalyst bed 28 below each release chamber after the release of the first product gas stream from the first released catalyst stream and the release of the second product gas stream from the second released catalyst stream. The bottom edge or a part thereof of the second release chamber 60 and the bottom edge or a part thereof of the first release chamber 11 are spaced apart from the shell 15 of the reaction vessel 10 to enable the first released catalyst stream and the second released catalyst stream to be mixed within the high-concentration catalyst bed 28 and provide a mixed stream of the released catalyst. The second product gas stream passes upward through the second upper outlet 66 and is discharged from the second release chamber 60.

[0034] The first upper outlet 24 of the first liberation chamber 11 is positioned close to the second upper outlet 66 of the second liberation chamber 60. Both the first upper outlet 24 and the second upper outlet 66 are located below the gas recovery conduit 26. The first product gas stream from the first upper outlet 24 and the second product gas stream from the second upper outlet 66 both exit from below the gas recovery conduit 26. The first product gas stream and the second product gas stream are both mixed within the gas recovery conduit 26 after the liberation of the first product gas stream from the first liberated catalyst stream and the liberation of the second product gas stream from the second liberated catalyst stream. The mixed product gas stream containing the first product gas stream and the second product gas stream will typically contain a small amount of catalyst particles. The gas recovery conduit 26 recovers the mixed product gas stream in the same manner as the stripping gas described below. The amount of catalyst particles in the gas entering the conduit 26 is usually less than 16 grams per liter (1 lb / ft 3 ) and typically less than 1.6 grams per liter (0.1 lb / ft 3 ).

[0035] The first upper outlet 24 and the second upper outlet 66 are below one or more cyclone inlets 40 near the upper end of the gas recovery conduit 26, which may include a wider portion of the gas recovery conduit. The gas recovery conduit 26 passes the mixed product gas stream from the first upper outlet 24 and the second upper outlet 66 through the cyclone inlets 40 into the cyclone 28 or through the inlet ducts leading to the respective cyclones 28 through a plurality of cyclone inlets 40. The cyclone 28 further removes particulate matter from the mixed product gas stream from the gas recovery conduit 26. Each cyclone 28 can operate in a conventional manner as a conventional direct-connected cyclone, with the gas flowing in tangentially to create a swirling action within the cyclone and establishing an inner vortex and an outer vortex for separating the catalyst from the gas. The cyclone 28 supplies the product gas containing a smaller amount of catalyst through the outlet duct to the plenum 29, from where the product stream relatively free of catalyst particles exits the reaction vessel 10 through the reactor outlet 30.

[0036] The catalyst recovered by cyclone 28 exits the bottom of the cyclone through dipleg conduit 27, proceeds to the bottom of reaction vessel 10, and is collected together with the released catalyst in high concentration bed 28 that has exited first release chamber 11 and second release chamber 60. The lower edge or a part of the wall 63 of the second release chamber 60 does not extend down to the wall 15 of the reaction vessel, allowing the catalyst from dipleg 27 to move to the bottom of reaction vessel 10 and be collected within high concentration catalyst bed 28.

[0037] The first lower outlet 19 of the first release chamber 11 and the second lower outlet 67 of the second release chamber 60 may be located above the catalyst stripper section 32. The mixed flow of released catalyst from high concentration catalyst bed 28 passes downward through stripping section 32. Stripping fluid, typically steam, enters the lower part of stripping section 32 through distributor 34. Countercurrent contact of the catalyst with the stripping fluid through a series of stripping baffles, packing, or grids removes product gas from the catalyst as the product gas continues to flow downward through stripping section 32. The first stripped catalyst stream from stripping section 32 passes through regenerator conduit 36 and reaches catalyst heater or regenerator 38, which heats the catalyst by heat exchange or regenerates the catalyst by contact with oxygen-containing gas. Catalyst heater or regenerator 38 provides a first high-temperature catalyst stream in first high-temperature catalyst tube 20 supplied to first riser 12 and a second high-temperature catalyst stream in second high-temperature catalyst tube 62 supplied to second riser 50.

[0038] The second stripped catalyst stream from high concentration bed 28 passes through recirculation conduit 42, supplies a first recirculation catalyst stream in first recirculation catalyst tube 22 to first riser 12, and supplies a second recirculation catalyst stream in second recirculation catalyst tube 71 to second riser 50.

[0039] The support lug 64 extends between the first release chamber 11 and the second release chamber 60 within the second release chamber. The support lug 64 is radially oriented such that the second product gas stream is prevented from swirling within the second release chamber 60 after an initial release from the second released catalyst stream. One or more support lugs 64 may be located above the second outlet 49 so as not to prevent swirling during the initial release. By using the support lug 64, the first release chamber 11 may be supported by the second release chamber 60 which may be supported by the reaction vessel 10. For example, the second release chamber 60 may have support lugs (not shown) fixed to the shell 15 of the reaction vessel 10 to support the second release chamber, or the second release chamber may be fixed to the plenum 29 through the upper portion of the gas recovery conduit 26. On the other hand, the second release chamber 60 may be supported by the first release chamber by using the support lug 64. Support lugs (not shown) may be fixed to the wall 17 of the first release chamber 11 and to the shell 15 of the reaction vessel for supporting thereby. Alternatively, the first release chamber 11 and the second release chamber 60 may be independently fixed to the shell 15 of the reaction vessel 10 for supporting thereby. The support lug 64 may be configured for the purpose of preventing vortices.

[0040] Figure 3 shows a cross-sectional elevation view of an FCC reaction vessel similar to the FCC reactor shown in Figure 1, in which, in accordance with the present invention, two or more additional separate third FCC reactor risers 70 are shown. In Figure 3, the second riser 50 and the separate third riser 70 extend outside the reaction vessel 10, although the use of more or fewer outer risers is contemplated. The third riser 70 includes a third discharge port 69 within the second release chamber 60. Similar to the second discharge port 49, the second release chamber 60 includes the third discharge port 69. In one embodiment, the second horizontal transfer line 68 of the third riser 70 terminates at the second release chamber 60. The third discharge port 69 discharges a second mixture of product gas and catalyst tangentially into the second release chamber 60. In other embodiments, the second horizontal transfer line 68 may be replaced with alternative connectors such as more acute or more obtuse T-connectors or elbows. The discharge ports 49 and 69 are symmetrically disposed about the second release chamber 60.

[0041] The third hydrocarbon feedstock is distributed into the third riser 70 from one or more feedstock distributors 73 near the base of the third riser. The third catalyst stream may be fluidized by the steam distributed from the distributor 65 at the bottom of the third riser 70. A steam flow rate of 25 wt% to 50 wt% of the third hydrocarbon feedstock can be added to the third riser 312. The third hydrocarbon feedstock contacts the third catalyst stream within the third riser 70. The third catalyst stream may be provided by a mixture of a third high-temperature catalyst stream from the third high-temperature catalyst tube 72 and a third recycle catalyst stream from the third recycle catalyst tube 74. The third hydrocarbon feedstock vaporizes and converts to or decomposes into a product gas containing hydrocarbons of a lower molecular weight than the feedstock. Due to molar expansion and evaporation, the third hydrocarbon feedstock and the product gas rise rapidly through the third riser 70 entraining the third catalyst stream as a third mixture of catalyst and product gas. The third catalyst stream may contain 0.005 wt% to 1.2 wt% of coke.

[0042] As best seen in FIG. 4, the second horizontal transfer line 68 enters the reaction vessel 10 through the wall 15 and then enters tangentially into the wall 63 of the second release chamber 60 at the third outlet 69, which is 180° from the second outlet 49. The third outlet 69 is located in the wall 63 of the second release chamber 60. Discharging the third mixture of catalyst and product gas tangentially through the third outlet 69 from the third riser 70 generates a spiral vortex pattern around the inside of the second release chamber 60, along with discharging the second mixture of catalyst and product gas tangentially through the second outlet 49 from the second riser 50. Releasing the second mixture of catalyst and product gas into the second product gas stream and releasing the third mixture of catalyst and product gas into the third product gas stream is done concentrically outside of releasing the first mixture of catalyst and product gas into the first product gas stream and the first released catalyst stream.

[0043] FIG. 5 shows an alternative embodiment of FIG. 2 using a transfer line 48' for transferring the catalyst and product gas from the second riser 50' to the second release chamber 60'. The transfer line 48' includes a riser outlet tube 45 and a release inlet tube 44 that slide relative to each other. A reaction tube 43 formed from the wall 15', extending from and communicating with the reaction vessel 10', includes the riser outlet tube 45 and the release inlet tube 44. An inert fluidizing gas, such as steam, can be supplied into the annulus between the reactor tube 43 and the riser outlet tube 45 and / or the release inlet tube 44 to contain gas and catalyst within its flow path. The arrangement of the transfer line 48' allows for independent thermal expansion of the transfer line 48', the riser 50', and the second release chamber 60'. FIG. 5 shows the release inlet tube 44 around the riser outlet tube 45, but this may be reversed.

Example

[0044] To confirm the separation efficiency of the device described in the present disclosure, a computational fluid dynamics (CFD) study was conducted. The separation efficiency is defined as the amount of catalyst particles separated by the release system from the total amount of catalyst particles entering the system. The separated catalyst particles return to the high-concentration catalyst bed below the release system. This study considered a reactor under typical operating conditions of 138 kPa gauge (20 psig) and 582 °C (1080 °F). In a conventional release system including an independent first release chamber, the estimated separation efficiency by CFD was 96.0%.

[0045] In the device described in the present disclosure, the first release chamber (11) had an estimated separation efficiency of 95.4%, and the second release chamber (60) had an estimated separation efficiency of 99.2%. The total separation efficiency of the device described in the present disclosure was observed to be 96.5%, which is superior to that of a conventional separation system having an independent first release chamber.

[0046] Specific Embodiments The following will be described in conjunction with specific embodiments, it being understood that this description is illustrative of the foregoing description and the scope of the appended claims and is not intended to limit them.

[0047] The first embodiment of the present invention is a process for the catalytic conversion of a hydrocarbon feedstock, the process comprising contacting a first hydrocarbon feedstock with a first catalyst stream in a first riser to produce a first mixture of catalyst and product gas, the first riser terminating within a reaction vessel, contacting a second hydrocarbon feedstock with a second catalyst stream in a second riser to produce a second mixture of catalyst and product gas, discharging the first mixture of catalyst and product gas from the first riser into a first liberation chamber within the reaction vessel, and discharging the second mixture of catalyst and product gas from the second riser into a second liberation chamber. One embodiment of the present invention is one, any, or all of the embodiments of this paragraph up to and including the first embodiment of this paragraph, further comprising liberating the first mixture of catalyst and product gas in the first liberation chamber into a first product gas stream and a first liberated catalyst stream, and separately liberating the second mixture of catalyst and product gas in the second liberation chamber into a second product gas stream and a second liberated catalyst stream. One embodiment of the present invention is one, any, or all of the embodiments of this paragraph up to and including the first embodiment of this paragraph, further comprising mixing the first product gas stream and the second product gas stream after liberation of the first product gas stream from the first liberated catalyst stream and liberation of the second product gas stream from the second liberated catalyst stream. One embodiment of the present invention is one, any, or all of the embodiments of this paragraph up to and including the first embodiment of this paragraph, further comprising mixing the first liberated catalyst stream and the second liberated catalyst stream after liberation of the first product gas stream from the first liberated catalyst stream and liberation of the second product gas stream from the second liberated catalyst stream. One embodiment of the present invention is one, any, or all of the embodiments of this paragraph up to and including the first embodiment of this paragraph, further comprising liberating the first mixture of catalyst and product gas into a first product gas stream and a first liberated catalyst stream, and liberating the second mixture of catalyst and product gas into a second product gas stream and a second liberated catalyst stream, concentrically with each other.One embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph up to and including the first embodiment of this paragraph, and further includes centrifugally discharging a first mixture of catalyst and product gas from a riser through a vortex tube into a first release chamber. One embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph up to and including the first embodiment of this paragraph, and further includes tangentially discharging a second mixture of catalyst and product gas from a second riser into a second release chamber.

[0048] A second embodiment of the present invention is an apparatus for separating a catalyst from a product gas, the apparatus comprising a first riser having a first discharge port, the first riser terminating within a reaction vessel, the first riser, a second riser having a second discharge port, a first release chamber located within the reaction vessel and including the first discharge port, and a second release chamber located within the same reaction vessel and including the second discharge port. One embodiment of the present invention is one, any, or all of the embodiments so far in this paragraph up to the second embodiment of this paragraph, the first riser is located at the center within the first release chamber, and the second discharge port is located on the wall of the second release chamber. One embodiment of the present invention is one, any, or all of the embodiments so far in this paragraph up to the second embodiment of this paragraph, the second release chamber surrounds the first release chamber. One embodiment of the present invention is one, any, or all of the embodiments so far in this paragraph up to the second embodiment of this paragraph, the second release chamber is annular with respect to the first release chamber. One embodiment of the present invention is one, any, or all of the embodiments so far in this paragraph up to the second embodiment of this paragraph, the inner wall of the second release chamber is the outer wall of the first release chamber. One embodiment of the present invention is one, any, or all of the embodiments so far in this paragraph up to the second embodiment of this paragraph, further comprising a first upper outlet of the first release chamber located in proximity to the second upper outlet of the second release chamber. One embodiment of the present invention is one, any, or all of the embodiments so far in this paragraph up to the second embodiment of this paragraph, the first upper outlet and the second upper outlet are below the cyclone inlet. One embodiment of the present invention is one, any, or all of the embodiments so far in this paragraph up to the second embodiment of this paragraph, the first release chamber is supported by a second release chamber supported by the reaction vessel, or the second release chamber is supported by a first release chamber supported by the reaction vessel.One embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph up to the second embodiment of this paragraph. The support lag extends between the first release chamber 11 and the second release chamber 60 within the second release chamber, and the lag is radially oriented to prevent the mixture of catalyst and product gas from swirling within the second release chamber 60. One embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph up to the second embodiment of this paragraph, and further includes a third riser having a third discharge port and a second release chamber including the third discharge port. One embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph up to the second embodiment of this paragraph. The second riser includes a transfer conduit for transferring the catalyst and product gas to the second release chamber, and the transfer conduit includes a riser outlet pipe and a release inlet pipe that slide relative to each other. One embodiment of the present invention is one, any, or all of the previous embodiments of this paragraph up to the second embodiment of this paragraph, and further includes a first lower outlet of the first release chamber located adjacent to the second lower outlet of the second release chamber. Embodiments of the present invention are one, any, or all of the previous embodiments of this paragraph up to the second embodiment of this paragraph. The first lower outlet and the second lower outlet are above the catalyst stripper.

[0049] A third embodiment of the present invention is an apparatus for separating a catalyst from a product gas, the apparatus comprising: a first riser having a first outlet, the first riser terminating within a reaction vessel; a second riser having a second outlet; a first release chamber located within the reaction vessel and including the first outlet; and a second release chamber located within the same reaction vessel, surrounding the first release chamber and including the second outlet. One embodiment of the present invention is one, any, or all of the embodiments thus far in this paragraph up to the third embodiment of this paragraph. The first riser is located at the center of the first release chamber, and the second outlet is located on the side wall of the second release chamber. One embodiment of the present invention is one, any, or all of the embodiments thus far in this paragraph up to the third embodiment of this paragraph. The second release chamber is annular with respect to the first release chamber. One embodiment of the present invention is one, any, or all of the embodiments thus far in this paragraph up to the third embodiment of this paragraph. The inner wall of the second release chamber is the outer wall of the first release chamber.

[0050] Without further elaboration, using the foregoing description, one skilled in the art should be able to utilize the present invention to its fullest extent without departing from the spirit and scope of the present invention and should be able to readily ascertain the essential characteristics of the present invention, make various changes and modifications to the present invention, and adapt it to various uses and conditions. Accordingly, the foregoing preferred specific embodiments should be construed as merely illustrative and not in any way limiting the remainder of the disclosure, which is intended to cover various modifications and equivalent constructions within the scope of the appended claims.

[0051] In the above, all temperatures are given in degrees Celsius, and all parts and percentages are by weight unless otherwise indicated.

Claims

1. A process for the catalytic conversion of a hydrocarbon feedstock, said process comprising: contacting a first hydrocarbon feedstock with a first catalyst stream in a first riser to produce a first mixture of catalyst and product gas, said first riser terminating within a reaction vessel; contacting a second hydrocarbon feedstock with a second catalyst stream in a second riser to produce a second mixture of catalyst and product gas; discharging said first mixture of catalyst and product gas from said first riser into a first liberation chamber within said reaction vessel; discharging said second mixture of catalyst and product gas from said second riser into a second liberation chamber; a process for the catalytic conversion of a hydrocarbon feedstock.

2. The process of claim 1, further comprising separately liberating said first mixture of catalyst and product gas in said first liberation chamber into a first product gas stream and a first liberated catalyst stream, and separately liberating said second mixture of catalyst and product gas in said second liberation chamber into a second product gas stream and a second liberated catalyst stream.

3. The process of claim 2, further comprising mixing said first product gas stream and said second product gas stream after said liberation of said first product gas stream from said first liberated catalyst stream and said liberation of said second product gas stream from said second liberated catalyst stream.

4. The process of claim 2, further comprising mixing said first liberated catalyst stream and said second liberated catalyst stream after said liberation of said first product gas stream from said first liberated catalyst stream and said liberation of said second product gas stream from said second liberated catalyst stream.

5. The process of claim 2, further comprising concentrically liberating said first mixture of catalyst and product gas into said first product gas stream and said first liberated catalyst stream, and liberating said second mixture of catalyst and product gas into said second product gas stream and said second liberated catalyst stream.

6. An apparatus for separating catalyst from product gas, said apparatus comprising: a first riser having a first outlet, said first riser terminating within a reaction vessel; a first riser; a second riser having a second outlet; a first liberation chamber located within said reaction vessel and including said first outlet; An apparatus for separating a catalyst from a product gas, comprising a second release chamber located within the same reaction vessel and including the second discharge port. **Claim 7** The apparatus according to claim 6, wherein the first riser is located at the center of the first release chamber, and the second discharge port is located on the wall of the second release chamber. **Claim 8** The apparatus according to claim 6, wherein the second release chamber surrounds the first release chamber. **Claim 9** The apparatus according to claim 6, wherein the second release chamber is annular with respect to the first release chamber. **Claim 10** The apparatus according to claim 6, wherein the inner wall of the second release chamber is the outer wall of the first release chamber.

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