CA1314259C - Liquid degaser in an ebullated bed process - Google Patents
Liquid degaser in an ebullated bed processInfo
- Publication number
- CA1314259C CA1314259C CA000600481A CA600481A CA1314259C CA 1314259 C CA1314259 C CA 1314259C CA 000600481 A CA000600481 A CA 000600481A CA 600481 A CA600481 A CA 600481A CA 1314259 C CA1314259 C CA 1314259C
- Authority
- CA
- Canada
- Prior art keywords
- flow
- conduit
- catalyst
- riser
- angle
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Abstract
LIQUID DEGASER IN AN EBULLATED BED PROCESS
(D#78,996-F) ABSTRACT OF THE DISCLOSURE
In an ebullated bed reactor it has been found that an improved gas-liquid separator effectively removes gas from recycle liquid used to ebullate the catalyst bed. The gas-liquid separator comprises a cup with a plurality of riser conduits.
Deflecting members direct the riser conduit outlet flow at an angle to cause horizontal circulation in the cup, thereby causing cyclonic liquid-vapor separation.
(D#78,996-F) ABSTRACT OF THE DISCLOSURE
In an ebullated bed reactor it has been found that an improved gas-liquid separator effectively removes gas from recycle liquid used to ebullate the catalyst bed. The gas-liquid separator comprises a cup with a plurality of riser conduits.
Deflecting members direct the riser conduit outlet flow at an angle to cause horizontal circulation in the cup, thereby causing cyclonic liquid-vapor separation.
Description
\ \
131~25q LIQUID DEGASER IN AN EBULLATED BED PROCESS
(D#78,996-F) BACKGROUND OF THE INVENTION
1. Field of the Invention This invention relates to an improved vapor-liquid separator in an ebullated bed process. The separator comprises a cup with a plurality of riser conduits. Specifically, the invention relates to an additional separation stage comprising directing flow discharged from the riser conduits circularly in the cup.
131~25q LIQUID DEGASER IN AN EBULLATED BED PROCESS
(D#78,996-F) BACKGROUND OF THE INVENTION
1. Field of the Invention This invention relates to an improved vapor-liquid separator in an ebullated bed process. The separator comprises a cup with a plurality of riser conduits. Specifically, the invention relates to an additional separation stage comprising directing flow discharged from the riser conduits circularly in the cup.
2. Desc~ O _____ ther Relevant Methods ln the Field The ebullated bed process comprises the passing of concurrently flowing streams of liquids or slurries of liquids and solids and gas through a ver~ically cylindrical vessel containing catalyst. The catalyst is placed in random motion in the liquid and has a gross volume dispersed through the liquid medium greater than the volume of the mass when stationary. This technology has found commercial application in the upgrading of heavy liquid hydrocarbons or converting coal to synthetic oils.
The process is generally described in U.S. Patent No. Re 25,770 to E. S. Johanson. A mixture of hydrocarbon liquid and hydrogen is passed upwardly through a bed of catalyst particles at a rate such that the particles are forced into random motion as the liquid and gas pass upwardly through the bed. The catalyst 131425q bed motion is controlled by a recycle liquid flow so that at steady state, the bulk of the catalyst does not rise above a definable level in the reactor. Vapors along with the liquid which is being hydrogenated pass through that upper level of catalyst particles into a substantially catalyst free zone and are removed at the upper portion of the reactor.
In an ebullated bed process substantial amounts of hydrogen qas and light hydrocarbon vapors rise through the reaction zone into the catalyst free zone. Liquid is both recycled to the bottom of the reactor and removed from the reactor as product from this catalyst free zone. Vapor is separated from the liquid recycle stream before being passed through the recycle conduit to the recycle pump suction. The recycle pump (ebullation pump) maintains catalyst bed expansion (ebullation) and random motion of catalyst particles at a constant and stable level.
Gases or vapors present in the recycled liquid materially decrease the capacity of the recycle pump as well as reduce the liquid residence time in the reactor and limit hydrogen partial pressure.
. .~,~,.
1 31 425'~
Reactors employed in a catalytic hydrogenation process with an ebullated bed of catalyst particles are designed with a central vertical recycle conduit which serves as the downcomer for recycling liquid from the catalyst free zone above the ebullated catalyst bed to the suction of a recycle pump to recirculate the liquid through the catalytic reaction zone. The recycling of liquid from the upper portion of the reactor serves to ebullate the catalyst bed, maintain temperature uniformity through the reactor and stabilize the catalyst bed.
U. S. Patent No. 4,221,653 to M. C. Chervenak et al~
describes an apparatus for separating vapor from liquid in an ebullated bed process. The apparatus comprises a frusto-conical cup in which are inserted a plurality of riser conduits. The conduits are positioned in two concentric circles within the cup.
The generic term for the recycle gas-liquid separator apparatus in an ebullating bed process is a recycle cup. The recycle cup of the Chervenak et al. patent and those like it with a plurality of riser conduits are referred to as a tubular recycle cup.
It is a critical feature of the recycle cup that the upflowing liquid-gas mixture rising from the reaction zone passes through the riser conduits of the separation apparatus and that lower ends of all conduits are below the reactor liquid level.
After passage through the recycle cup, the gas portion rises to the top of the reactor. Part of the liquid portion is returned through a downcomer conduit and recycled to the reaction zone.
1 3 1 ~259 The remaining liquid portion is withdrawn from the reactor as liquid product. The returned liquid portion passes through the recycle conduit to a recycle pump, then passes through a liquid-gas distribution means, together with fresh liquid and hydrogen feed to maintain uniform upward fluid flow through the ebullated catalyst bed. The liquid and vapor effluent may be withdrawn separately from the upper portion of the reactor. If withdrawn ~eparately, a second interface between liquid and vapor is established. Vapor is withdrawn from above the interface.
The liquid is withdrawn from a point in the reactor free of vapor. If desired, liquid and vapor portions may be withdrawn together through a single conduit extending into the reactor to a position adjacent the separator apparatus.
U. S. Patent No. 4,151,073 to A. G. Comolli and U. S.
Patent No. 4,354,852 to P. H. Kydd recognize the advantages of effecting the recycle liquid-vapor separation in an ebullated bed process by feeding the fluid tangentially to a cylindrical separator. By this method, the hot fluid is fed to the cylindrical separator at conditions to prevent carbonaceous particulate material from depositing on the interior surface of the separator. These conditions include tangential injection of feed to the separator, fluid temperature of 550F to 900F and a separator length/diameter ratio of 20/1 to 50/1. The Kydd patent additionally teaches that a liquid vortex in the cylindrical separator reduces coke deposition.
1 31 4~59 The design of liquid cyclone separators is well known in the art. For example, U.S. Patent Nos. 3,668,116 to C. E. A~ams et al. describe~ the use of a liquid cyclone in an ebullated bed process. An essential feature of any cyclone is tangential feed to a circumferential wall.
U.S. Patent No. 4,443,551 to T. A. Lionetti et al.
teaches a distributor apparatus for delivering high velocity gas from a gas distributor through a nozzle. The nozzles are positioned to direct gas at specified angles in a fluid catalytic cracking process regenerator.
The present invention provides in combination with a high pressure reaction vessel adapted for the reaction of a fluid hydrocarbon feed with a hydrogen rich gas at elevated temperatures and pressures in the presence of a bed of a particulate solid catalyst, said reaction being the type wherein the gas and hydrocarbon feed are passed upwardly through the bed at velocities whereby the hed is expanded to a volume greater than its static volume and the particulate solid catalyst is put in a state of random motlon and wherein the mixture of hydrocarbon feed, gas and catalyst constitute a catalytic reaction zone wherein minimum catalyst settling takes place, the upper portion of which is defined by a liquid continuous, catalyst depleted zone substantially free of catalyst the upper portion of which liquid continuous, catalyst depleted zone is positioned;
a generally vertical recycle conduit having an enlarged upper end of generally circular cross-section in fluid communication 1 3 1 ~259 with a phase separation zone and a lower end in fluld communication with means for recycling liquid from the catalyst depleted zone to the lower end of the catalytic reaction zone and a plurality of generally vertical riser conduits adapted for fluid flow therethrough extending through the enlarged upper end having lower ends in fluid communication with said catalyst depleted zone and upper ends, the improvement to the recycle conduit comprising:
(a) means for directing flow from the upper end of the riser conduit at an angle of 30 to 6C in the horizontal plane from a line constructed between the geometric center of the recycle conduit and the geometric center of the riser conduit.
The present invention also provides in a high pressure reaction vessel adapted for the reaction of a fluid hydrocarbon feed with a hydrogen rich gas at elevated temperatures and pressures in the presence of a hed of a particulate solid catalyst, said reaction being the type wherein the gas and hydrocarbon feed are passed upwardly through the bed at velocities whereby the bed is expanded to a volume greater than its static volume and the particulate solid catalyst is put in a state of random motion and wherein the mixture of hydrocarbon feed, gas and catalyst constitute a catalytic reaction zone, the upper portion of which is defined hy a catalys~ depleted zone in which is positioned; a generally vertical recycle conduit having an enlarged upper end of circular horizontal cross-section in fluid communication with a phase separation zone and a lower end in fluid communication with means for recycling liquid from the 5a 1 31 ~259 68626-232 catalyst depleted zone to the lower end of the catalytic reaction ~one and a plurality of generally vertical riser conduits providing a plurality of vertical rectilinear fluid flows there through, said riser conduits extending through the enlarged upper end having lower ends in fluid communication wi~h said catalyst depleted zone and upper ends, the improvement comprising: flow directing means attached to said upper ends adapted to comhine the plurality of rectilinear flows into a single circular flow in the horizontal plane within said enlarged upper end.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a sectional elevated view of a reaction vessel containing a tubular recycle cup vapor-liquid separation apparatus.
Figure 2 is a cross-sectional view of a riser conduit comprising a flow deflecting member.
Figure 3a is a plan view of flow deflecting members oriented with a recycle conduit. Figure 3b is an enlarged plan view of a deflecting member with orientation.
DETAILED DESCRIPTION OF THE DRAWINGS
In order to demonstrate and provide a better understanding of the invention, reference is made to the drawings.
5b 2 ~,' 9 The invention is further illustrated by reference to Figure 1. Reaction vessel 10 is positioned with its long axis in a vertical position and is generally of a circular cross section.
Although this Figure 1 drawing is schematic in order to show its various features, it will be understood that the reactor is constructed in such a fashion and from such materials that it is suitable for reacting liquids, liquid-solid slurries, fluidized solids and gases at elevated temperatures and pressures and in a preferred embodiment for treating hydrocarbon liquids with hydrogen at high pressures and high temperatures, e.g. 100 to 5000 psi and 300F to 1500DF. The reactor lO is fitted with a suitable inlet conduit 12 for feeding heavy oil and a hydrogen-containing gas. Outlet conduits are located in the upper portion of reactor 10; outlet conduit 40 designed to withdraw vapor and liquid, and optionally outlet conduit 24 to withdraw mainly liquid product. The reactor also contains means for introducing and withdrawing catalyst particles, which are shown schematically as conduit 1~ through which fresh catalyst 16 is flowed and conduit 17 through which spent catalyst 14 is withdrawn.
Heavy oil feedstock is introduced through conduit 11, while hydrogen-containing gas is introduced through conduit 13, and may be combined with the feedstock and fed into reactor 10 through conduit 12 in the bottom of the reactor. The incoming fluid passes through grid tray 18 containing suitable fluid distribution means. In this drawing, bubble caps 19 are shown as t7)1~259 the fluid distribution means, but it is to be understood that any suitable device known in the art which will uniformly distribute the fluid coming from conduit 12 over the entire cross-sectional area of reactor 10 may be utilized.
The mixture of liquid and gas flows upwardly, and the catalyst particles are thereby forced into an ebullated movement by the gas flow and the liquid flow delivered by recycle pump 20 (ebullation pump) which may be either internal or external to the reactor 10. The upward liquid flow delivered by this recycle pump 20 is sufficient to cause the mass of catalyst particles in catalytic reaction zone 22 (catalyst bed) to expand by at least 10~ and usually by 20 to 100% over the static volume, thus permitting gas and liquid flow as shown by direction arrow 21 through reactor 10. Due to the upwardly directed flow provided by the pump and the downward forces provided by gravity, the catalyst bed particles reach an upward level of travel or ebullation while the lighter liquid and gas continue to move upward beyond that level. In this drawing, the upper level of catalyst or catalyst-liquid interface is shown as interface 23, and the catalytic reaction zone 22 extends from grid tray 18 to level 23. Catalyst particles in catalytic reaction zone 22 move randomly and are uniformly distributed through the entire zone in reactor 10.
At steady state, few catalyst particles rise above catalyst-liquid interface 23. The catalyst depleted zone 29, above the interface 2~, is filled with liquid and entrained gas or vapor. Gas and vapor are separated from liquid in the recycle cup 30 to collect and recycle a liquid with a substantially reduced gas and vapor content through recycle conduit 25 of generally circular cross-sectional area. A substantially liquid product may be withdrawn separately from gas and vapor through conduit 24, in which event conduit 40 terminates in a vapor space and is used to withdraw vapor alone. Alternatively gases, vapors, and liquids may be withdrawn together through conduit 40.
The enlarged upper end of recycle conduit 25 is the recycle cup 30 of horizontally circular cross-section. A
plurality of vertically directed riser conduits 27 and 28 provides fluid communication between catalyst depleted zone 29 and phase separation zone 39. Gas-entrained liquid moves upwardly through the riser conduits 27 and 28, and upon leaving the upper ends of these riser conduits, a portion of the fluid reverses direction and flows downward through recycle conduit 25 in the direction of arrow 31 to the inlet of recycle pump 20 and thereby is recycled to the lower portion of reactor 10 below grid tray 18. Gases and vapors which are separated from the liquid, rise to collect in the upper portion of reactor 10 and are removed through outlet conduit 40. The gases and vapors removed at this point are treated using conventional means to recover as much hydrogen as possible for recycle to conduit 13.
Reference is made to Figure 2. Figure 2 is a cross-sectional view of the Figure 1 configuration of a single riser conduit 28 which is positioned in recycle cup 30 in reactor lQ. Gas-entrained liquid 41, represented as a flow arrow coincident with the geometric center 28a of riser conduit 28, moves upwardly into riser conduit 28 where it contacts helical member 42. Helical member 42 imparts a tangential velocity component to the gas-entrained liquid 41 and directs it tangentially toward cyclone separator 50. Cyclone separator 50 effects a vapor-liquid separation. Separated vapor 65 is redirected through directing member 55 through an angle of 30 to to 90 preferably 30 to 60 most preferably 45 to become redirected vapor 65a to a relatively vapor rich zone such as a vapor zone if a vapor-liquid interface exists within reactor 10.
Separated liquid 45 flows downward along the surface toward recycle conduit 25 in the direction of arrow 31.
Reference is made to Figure 3a and Figure 3b.
Figure 3a is a plan view of a plurality of deflecting members 55 oriented with respect to the geometric center 25a of the recycle conduit 25 and with respect to the recycle cup 30. Figure 3b is an enlarged plan view of a single deflecting member 55 with orientation. Deflecting member 55 is oriented such that when a line 80 is constructed between the geometric center 25a of the 131~25'~
6862~-232 recycle conduit 25 and the geometric center 2~a of the riser conduit 28, flow is deflected along flow line 99 at an angle of to 60 preferably 45 in the horizontal plane to the constructed line.
It is found that the deflection of riser conduit flow in the angle of 45 in the horizontal plane and ~5 in the vertical plane takes greatest advantage of the circularity of the recycle cup 30. As seen in Fig. 3a, these angles are effective in combining the plurality of vertical rectilinear flow through the riser conduits into a single coherent circumferential flow in the horizontal plane. The circular cross-section of both the recycle cup 30 and reactor vessel 10 are utilized to greater advantage.
The induced tangential flow enhances liquid-vapor separation by creating a second stage of cyclonic separation within the recycle cup and above the recycle cup within the upper portion of the reactor vessel. The existing equlpment is therefore u~ilized to better process advantage.
While particular embodiments of the invention have been described, it is well understood that the invention is not limited thereto since modifications may be made. For example, elevation angle is adjusted with liquid level in the recycle cup to optimize separation efficiency. It is therefore contemplated to cover by the appended claims any such modifications as fall within the spirit and scope of the claims.
The process is generally described in U.S. Patent No. Re 25,770 to E. S. Johanson. A mixture of hydrocarbon liquid and hydrogen is passed upwardly through a bed of catalyst particles at a rate such that the particles are forced into random motion as the liquid and gas pass upwardly through the bed. The catalyst 131425q bed motion is controlled by a recycle liquid flow so that at steady state, the bulk of the catalyst does not rise above a definable level in the reactor. Vapors along with the liquid which is being hydrogenated pass through that upper level of catalyst particles into a substantially catalyst free zone and are removed at the upper portion of the reactor.
In an ebullated bed process substantial amounts of hydrogen qas and light hydrocarbon vapors rise through the reaction zone into the catalyst free zone. Liquid is both recycled to the bottom of the reactor and removed from the reactor as product from this catalyst free zone. Vapor is separated from the liquid recycle stream before being passed through the recycle conduit to the recycle pump suction. The recycle pump (ebullation pump) maintains catalyst bed expansion (ebullation) and random motion of catalyst particles at a constant and stable level.
Gases or vapors present in the recycled liquid materially decrease the capacity of the recycle pump as well as reduce the liquid residence time in the reactor and limit hydrogen partial pressure.
. .~,~,.
1 31 425'~
Reactors employed in a catalytic hydrogenation process with an ebullated bed of catalyst particles are designed with a central vertical recycle conduit which serves as the downcomer for recycling liquid from the catalyst free zone above the ebullated catalyst bed to the suction of a recycle pump to recirculate the liquid through the catalytic reaction zone. The recycling of liquid from the upper portion of the reactor serves to ebullate the catalyst bed, maintain temperature uniformity through the reactor and stabilize the catalyst bed.
U. S. Patent No. 4,221,653 to M. C. Chervenak et al~
describes an apparatus for separating vapor from liquid in an ebullated bed process. The apparatus comprises a frusto-conical cup in which are inserted a plurality of riser conduits. The conduits are positioned in two concentric circles within the cup.
The generic term for the recycle gas-liquid separator apparatus in an ebullating bed process is a recycle cup. The recycle cup of the Chervenak et al. patent and those like it with a plurality of riser conduits are referred to as a tubular recycle cup.
It is a critical feature of the recycle cup that the upflowing liquid-gas mixture rising from the reaction zone passes through the riser conduits of the separation apparatus and that lower ends of all conduits are below the reactor liquid level.
After passage through the recycle cup, the gas portion rises to the top of the reactor. Part of the liquid portion is returned through a downcomer conduit and recycled to the reaction zone.
1 3 1 ~259 The remaining liquid portion is withdrawn from the reactor as liquid product. The returned liquid portion passes through the recycle conduit to a recycle pump, then passes through a liquid-gas distribution means, together with fresh liquid and hydrogen feed to maintain uniform upward fluid flow through the ebullated catalyst bed. The liquid and vapor effluent may be withdrawn separately from the upper portion of the reactor. If withdrawn ~eparately, a second interface between liquid and vapor is established. Vapor is withdrawn from above the interface.
The liquid is withdrawn from a point in the reactor free of vapor. If desired, liquid and vapor portions may be withdrawn together through a single conduit extending into the reactor to a position adjacent the separator apparatus.
U. S. Patent No. 4,151,073 to A. G. Comolli and U. S.
Patent No. 4,354,852 to P. H. Kydd recognize the advantages of effecting the recycle liquid-vapor separation in an ebullated bed process by feeding the fluid tangentially to a cylindrical separator. By this method, the hot fluid is fed to the cylindrical separator at conditions to prevent carbonaceous particulate material from depositing on the interior surface of the separator. These conditions include tangential injection of feed to the separator, fluid temperature of 550F to 900F and a separator length/diameter ratio of 20/1 to 50/1. The Kydd patent additionally teaches that a liquid vortex in the cylindrical separator reduces coke deposition.
1 31 4~59 The design of liquid cyclone separators is well known in the art. For example, U.S. Patent Nos. 3,668,116 to C. E. A~ams et al. describe~ the use of a liquid cyclone in an ebullated bed process. An essential feature of any cyclone is tangential feed to a circumferential wall.
U.S. Patent No. 4,443,551 to T. A. Lionetti et al.
teaches a distributor apparatus for delivering high velocity gas from a gas distributor through a nozzle. The nozzles are positioned to direct gas at specified angles in a fluid catalytic cracking process regenerator.
The present invention provides in combination with a high pressure reaction vessel adapted for the reaction of a fluid hydrocarbon feed with a hydrogen rich gas at elevated temperatures and pressures in the presence of a bed of a particulate solid catalyst, said reaction being the type wherein the gas and hydrocarbon feed are passed upwardly through the bed at velocities whereby the hed is expanded to a volume greater than its static volume and the particulate solid catalyst is put in a state of random motlon and wherein the mixture of hydrocarbon feed, gas and catalyst constitute a catalytic reaction zone wherein minimum catalyst settling takes place, the upper portion of which is defined by a liquid continuous, catalyst depleted zone substantially free of catalyst the upper portion of which liquid continuous, catalyst depleted zone is positioned;
a generally vertical recycle conduit having an enlarged upper end of generally circular cross-section in fluid communication 1 3 1 ~259 with a phase separation zone and a lower end in fluld communication with means for recycling liquid from the catalyst depleted zone to the lower end of the catalytic reaction zone and a plurality of generally vertical riser conduits adapted for fluid flow therethrough extending through the enlarged upper end having lower ends in fluid communication with said catalyst depleted zone and upper ends, the improvement to the recycle conduit comprising:
(a) means for directing flow from the upper end of the riser conduit at an angle of 30 to 6C in the horizontal plane from a line constructed between the geometric center of the recycle conduit and the geometric center of the riser conduit.
The present invention also provides in a high pressure reaction vessel adapted for the reaction of a fluid hydrocarbon feed with a hydrogen rich gas at elevated temperatures and pressures in the presence of a hed of a particulate solid catalyst, said reaction being the type wherein the gas and hydrocarbon feed are passed upwardly through the bed at velocities whereby the bed is expanded to a volume greater than its static volume and the particulate solid catalyst is put in a state of random motion and wherein the mixture of hydrocarbon feed, gas and catalyst constitute a catalytic reaction zone, the upper portion of which is defined hy a catalys~ depleted zone in which is positioned; a generally vertical recycle conduit having an enlarged upper end of circular horizontal cross-section in fluid communication with a phase separation zone and a lower end in fluid communication with means for recycling liquid from the 5a 1 31 ~259 68626-232 catalyst depleted zone to the lower end of the catalytic reaction ~one and a plurality of generally vertical riser conduits providing a plurality of vertical rectilinear fluid flows there through, said riser conduits extending through the enlarged upper end having lower ends in fluid communication wi~h said catalyst depleted zone and upper ends, the improvement comprising: flow directing means attached to said upper ends adapted to comhine the plurality of rectilinear flows into a single circular flow in the horizontal plane within said enlarged upper end.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is a sectional elevated view of a reaction vessel containing a tubular recycle cup vapor-liquid separation apparatus.
Figure 2 is a cross-sectional view of a riser conduit comprising a flow deflecting member.
Figure 3a is a plan view of flow deflecting members oriented with a recycle conduit. Figure 3b is an enlarged plan view of a deflecting member with orientation.
DETAILED DESCRIPTION OF THE DRAWINGS
In order to demonstrate and provide a better understanding of the invention, reference is made to the drawings.
5b 2 ~,' 9 The invention is further illustrated by reference to Figure 1. Reaction vessel 10 is positioned with its long axis in a vertical position and is generally of a circular cross section.
Although this Figure 1 drawing is schematic in order to show its various features, it will be understood that the reactor is constructed in such a fashion and from such materials that it is suitable for reacting liquids, liquid-solid slurries, fluidized solids and gases at elevated temperatures and pressures and in a preferred embodiment for treating hydrocarbon liquids with hydrogen at high pressures and high temperatures, e.g. 100 to 5000 psi and 300F to 1500DF. The reactor lO is fitted with a suitable inlet conduit 12 for feeding heavy oil and a hydrogen-containing gas. Outlet conduits are located in the upper portion of reactor 10; outlet conduit 40 designed to withdraw vapor and liquid, and optionally outlet conduit 24 to withdraw mainly liquid product. The reactor also contains means for introducing and withdrawing catalyst particles, which are shown schematically as conduit 1~ through which fresh catalyst 16 is flowed and conduit 17 through which spent catalyst 14 is withdrawn.
Heavy oil feedstock is introduced through conduit 11, while hydrogen-containing gas is introduced through conduit 13, and may be combined with the feedstock and fed into reactor 10 through conduit 12 in the bottom of the reactor. The incoming fluid passes through grid tray 18 containing suitable fluid distribution means. In this drawing, bubble caps 19 are shown as t7)1~259 the fluid distribution means, but it is to be understood that any suitable device known in the art which will uniformly distribute the fluid coming from conduit 12 over the entire cross-sectional area of reactor 10 may be utilized.
The mixture of liquid and gas flows upwardly, and the catalyst particles are thereby forced into an ebullated movement by the gas flow and the liquid flow delivered by recycle pump 20 (ebullation pump) which may be either internal or external to the reactor 10. The upward liquid flow delivered by this recycle pump 20 is sufficient to cause the mass of catalyst particles in catalytic reaction zone 22 (catalyst bed) to expand by at least 10~ and usually by 20 to 100% over the static volume, thus permitting gas and liquid flow as shown by direction arrow 21 through reactor 10. Due to the upwardly directed flow provided by the pump and the downward forces provided by gravity, the catalyst bed particles reach an upward level of travel or ebullation while the lighter liquid and gas continue to move upward beyond that level. In this drawing, the upper level of catalyst or catalyst-liquid interface is shown as interface 23, and the catalytic reaction zone 22 extends from grid tray 18 to level 23. Catalyst particles in catalytic reaction zone 22 move randomly and are uniformly distributed through the entire zone in reactor 10.
At steady state, few catalyst particles rise above catalyst-liquid interface 23. The catalyst depleted zone 29, above the interface 2~, is filled with liquid and entrained gas or vapor. Gas and vapor are separated from liquid in the recycle cup 30 to collect and recycle a liquid with a substantially reduced gas and vapor content through recycle conduit 25 of generally circular cross-sectional area. A substantially liquid product may be withdrawn separately from gas and vapor through conduit 24, in which event conduit 40 terminates in a vapor space and is used to withdraw vapor alone. Alternatively gases, vapors, and liquids may be withdrawn together through conduit 40.
The enlarged upper end of recycle conduit 25 is the recycle cup 30 of horizontally circular cross-section. A
plurality of vertically directed riser conduits 27 and 28 provides fluid communication between catalyst depleted zone 29 and phase separation zone 39. Gas-entrained liquid moves upwardly through the riser conduits 27 and 28, and upon leaving the upper ends of these riser conduits, a portion of the fluid reverses direction and flows downward through recycle conduit 25 in the direction of arrow 31 to the inlet of recycle pump 20 and thereby is recycled to the lower portion of reactor 10 below grid tray 18. Gases and vapors which are separated from the liquid, rise to collect in the upper portion of reactor 10 and are removed through outlet conduit 40. The gases and vapors removed at this point are treated using conventional means to recover as much hydrogen as possible for recycle to conduit 13.
Reference is made to Figure 2. Figure 2 is a cross-sectional view of the Figure 1 configuration of a single riser conduit 28 which is positioned in recycle cup 30 in reactor lQ. Gas-entrained liquid 41, represented as a flow arrow coincident with the geometric center 28a of riser conduit 28, moves upwardly into riser conduit 28 where it contacts helical member 42. Helical member 42 imparts a tangential velocity component to the gas-entrained liquid 41 and directs it tangentially toward cyclone separator 50. Cyclone separator 50 effects a vapor-liquid separation. Separated vapor 65 is redirected through directing member 55 through an angle of 30 to to 90 preferably 30 to 60 most preferably 45 to become redirected vapor 65a to a relatively vapor rich zone such as a vapor zone if a vapor-liquid interface exists within reactor 10.
Separated liquid 45 flows downward along the surface toward recycle conduit 25 in the direction of arrow 31.
Reference is made to Figure 3a and Figure 3b.
Figure 3a is a plan view of a plurality of deflecting members 55 oriented with respect to the geometric center 25a of the recycle conduit 25 and with respect to the recycle cup 30. Figure 3b is an enlarged plan view of a single deflecting member 55 with orientation. Deflecting member 55 is oriented such that when a line 80 is constructed between the geometric center 25a of the 131~25'~
6862~-232 recycle conduit 25 and the geometric center 2~a of the riser conduit 28, flow is deflected along flow line 99 at an angle of to 60 preferably 45 in the horizontal plane to the constructed line.
It is found that the deflection of riser conduit flow in the angle of 45 in the horizontal plane and ~5 in the vertical plane takes greatest advantage of the circularity of the recycle cup 30. As seen in Fig. 3a, these angles are effective in combining the plurality of vertical rectilinear flow through the riser conduits into a single coherent circumferential flow in the horizontal plane. The circular cross-section of both the recycle cup 30 and reactor vessel 10 are utilized to greater advantage.
The induced tangential flow enhances liquid-vapor separation by creating a second stage of cyclonic separation within the recycle cup and above the recycle cup within the upper portion of the reactor vessel. The existing equlpment is therefore u~ilized to better process advantage.
While particular embodiments of the invention have been described, it is well understood that the invention is not limited thereto since modifications may be made. For example, elevation angle is adjusted with liquid level in the recycle cup to optimize separation efficiency. It is therefore contemplated to cover by the appended claims any such modifications as fall within the spirit and scope of the claims.
Claims (12)
1. In combination with a high pressure reaction vessel adapted for the reaction of a fluid hydrocarbon feed with a hydrogen rich gas at elevated temperatures and pressures in the presence of a bed of a particulate solid catalyst, said reaction being the type wherein the gas and hydrocarbon feed are passed upwardly through the bed at velocities whereby the bed is expanded to a volume greater than its static volume and the particulate solid catalyst is put in a state of random motion and wherein the mixture of hydrocarbon feed, gas and catalyst constitute a catalytic reaction zone wherein minimum catalyst settling takes place, the upper portion of which is defined by a liquid continuous, catalyst depleted zone substantially free of catalyst the upper portion of which liquid continuous, catalyst depleted zone is positioned;
a generally vertical recycle conduit having an enlarged upper end of generally circular cross-section in fluid communication with a phase separation zone and a lower end in fluid communication with means for recycling liquid from the catalyst depleted zone to the lower end of the catalytic reaction zone and a plurality of generally vertical riser conduits adapted for fluid flow therethrough extending through the enlarged upper end having lower ends in fluid communication with said catalyst depleted zone and upper ends, the improvement to the recycle conduit comprising:
(a) means for directing flow from the upper end of the riser conduit at an angle of 30° to 60° in the horizontal plane from a line constructed between the geometric center of the recycle conduit and the geometric center of the riser conduit.
a generally vertical recycle conduit having an enlarged upper end of generally circular cross-section in fluid communication with a phase separation zone and a lower end in fluid communication with means for recycling liquid from the catalyst depleted zone to the lower end of the catalytic reaction zone and a plurality of generally vertical riser conduits adapted for fluid flow therethrough extending through the enlarged upper end having lower ends in fluid communication with said catalyst depleted zone and upper ends, the improvement to the recycle conduit comprising:
(a) means for directing flow from the upper end of the riser conduit at an angle of 30° to 60° in the horizontal plane from a line constructed between the geometric center of the recycle conduit and the geometric center of the riser conduit.
2. The recycle conduit of Claim 1 additionally comprising:
(b) means for directing flow from the upper end of the riser conduit at an angle of 30° to 90° to the flow within the riser conduit.
(b) means for directing flow from the upper end of the riser conduit at an angle of 30° to 90° to the flow within the riser conduit.
3. The recycle conduit of Claim 1 additionally comprising:
(b) means for directing flow from the upper end of the riser conduit at an angle of 30° to 60° to the flow within the riser conduit.
(b) means for directing flow from the upper end of the riser conduit at an angle of 30° to 60° to the flow within the riser conduit.
4. The recycle conduit of Claim 1 comprising:
(a) means for directing flow from the upper end of the riser conduit at an angle of 45° in the horizontal plane from a line constructed between the geometric center of the recycle conduit and the geometric center of the riser conduit.
(a) means for directing flow from the upper end of the riser conduit at an angle of 45° in the horizontal plane from a line constructed between the geometric center of the recycle conduit and the geometric center of the riser conduit.
5. The recycle conduit of Claim 1 comprising:
(a) means for directing flow from the upper end of the riser conduit at an angle of 45° in the horizontal plane from a line constructed between the geometric center of the recycle conduit and the geometric center of the riser conduit, and (b) means for directing flow from the upper end of the riser conduit at an angle of 45° to the flow within the riser conduit.
(a) means for directing flow from the upper end of the riser conduit at an angle of 45° in the horizontal plane from a line constructed between the geometric center of the recycle conduit and the geometric center of the riser conduit, and (b) means for directing flow from the upper end of the riser conduit at an angle of 45° to the flow within the riser conduit.
6. In a high pressure reaction vessel adapted for the reaction of a fluid hydrocarbon feed with a hydrogen rich gas at elevated temperatures and pressures in the presence of a bed of a particulate solid catalyst, said reaction being the type wherein the gas and hydrocarbon feed are passed upwardly through the bed at velocities whereby the bed is expanded to a volume greater than its static volume and the particulate solid catalyst is put in a state of random motion and wherein the mixture of hydrocarbon feed, gas and catalyst constitute a catalytic reaction zone, the upper portion of which is defined by a catalyst depleted zone in which is positioned;
a generally vertical recycle conduit having an enlarged upper end of circular horizontal cross-section in fluid communication with a phase separation zone and a lower end in fluid communication with means for recycling liquid from the catalyst depleted zone to the lower end of the catalytic reaction zone and a plurality of generally vertical riser conduits providing a plurality of vertical rectilinear fluid flows there through, said riser conduits extending through the enlarged upper end having lower ends in fluid communication with said catalyst depleted zone and upper ends, the improvement comprising:
flow directing means attached to said upper ends adapted to combine the plurality of rectilinear flows into a single circular flow in the horizontal plane within said enlarged upper end.
a generally vertical recycle conduit having an enlarged upper end of circular horizontal cross-section in fluid communication with a phase separation zone and a lower end in fluid communication with means for recycling liquid from the catalyst depleted zone to the lower end of the catalytic reaction zone and a plurality of generally vertical riser conduits providing a plurality of vertical rectilinear fluid flows there through, said riser conduits extending through the enlarged upper end having lower ends in fluid communication with said catalyst depleted zone and upper ends, the improvement comprising:
flow directing means attached to said upper ends adapted to combine the plurality of rectilinear flows into a single circular flow in the horizontal plane within said enlarged upper end.
7. The apparatus of Claim 6 wherein said flow directing means comprises a plurality of first flow directing members adapted for diverting each rectilinear flow at an angle of 30° to 60° in the horizontal plane from a line constructed in the horizontal plane between the geometric center of the recycle conduit and the geometric center of each riser conduit.
8. The apparatus of Claim 6 wherein said flow directing means comprises a plurality of first flow directing members adapted for diverting each rectilinear flow at an angle of 45° in the horizontal plane from a line constructed in the horizontal plane between the geometric center of each recycle conduit and the geometric center of each riser conduit.
9. The apparatus of Claim 6 wherein said flow directing means comprises a plurality of second flow directing members adapted for diverting each rectilinear flow at an angle of 30° to 90° from the vertical.
10. The apparatus of Claim 6 wherein said flow directing means comprises a plurality of second flow directing members adapted for diverting each rectilinear flow at an angle of 30° to 60° from the vertical.
11. The apparatus of Claim 6 wherein said flow directing means comprises a plurality of first flow directing members adapted for diverting each rectilinear flow at an angle of 30° to 60° in the horizontal plane from a line constructed in the horizontal plane between the geometric center of the recycle conduit and the geometric center of each riser conduit, and a plurality of second flow directing members adapted for diverting each rectilinear flow at an angle of 30° to 60° from the vertical.
12. The apparatus of Claim 6 wherein said flow directing means comprises a plurality of first flow directing members adapted for diverting each rectilinear flow at an angle of 45° in the horizontal plane from a line constructed in the horizontal plane between the geometric center of each recycle conduit and the geometric center of each riser conduit, and a plurality of second flow directing members adapted for diverting each rectilinear flow at an angle of 45° from the vertical.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US21174688A | 1988-06-27 | 1988-06-27 | |
| US07/211,746 | 1988-06-27 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1314259C true CA1314259C (en) | 1993-03-09 |
Family
ID=22788194
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000600481A Expired - Fee Related CA1314259C (en) | 1988-06-27 | 1989-05-24 | Liquid degaser in an ebullated bed process |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1314259C (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103100356A (en) * | 2011-11-10 | 2013-05-15 | 中国石油化工股份有限公司 | Boiling bed hydrogenation reactor and applications thereof |
-
1989
- 1989-05-24 CA CA000600481A patent/CA1314259C/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103100356A (en) * | 2011-11-10 | 2013-05-15 | 中国石油化工股份有限公司 | Boiling bed hydrogenation reactor and applications thereof |
| CN103100356B (en) * | 2011-11-10 | 2015-06-17 | 中国石油化工股份有限公司 | Boiling bed hydrogenation reactor and applications thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4886644A (en) | Liquid degaser in an ebullated bed process | |
| US4221653A (en) | Catalytic hydrogenation process and apparatus with improved vapor liquid separation | |
| US4354852A (en) | Phase separation of hydrocarbon liquids using liquid vortex | |
| US7449155B2 (en) | Reactor cup shell-in-shell riser for reaction vessel used in hydroconversion of fossil fuels | |
| CA2192911C (en) | Fluid catalytic cracking of hydrocarbons with integrated apparatus for separating and stripping catalyst | |
| US4874583A (en) | Bubble cap assembly in an ebullated bed reactor | |
| US5624642A (en) | Hydrocarbon processing apparatus | |
| CA2303307C (en) | Throat and cone gas injector and gas distribution grid for slurry reactor | |
| US5066467A (en) | Liquid degasser in an ebullated bed process | |
| US4971678A (en) | Liquid inventory control in an ebullated bed process | |
| US5308476A (en) | Reduced gas holdup in an ebullated bed reactor | |
| US3607126A (en) | Flow-directing device | |
| CA1314259C (en) | Liquid degaser in an ebullated bed process | |
| US4810359A (en) | Gas-liquid separation in an ebullated bed process | |
| JPH10503705A (en) | Catalyst support and use thereof | |
| US4804458A (en) | Process for collecting vapor in ebullated bed reactors | |
| US6667348B2 (en) | Throat and cone gas injector and gas distribution grid for slurry reactor {CJB-0004} | |
| US3475326A (en) | Transfer line apparatus and method | |
| US5098552A (en) | Controlling foam circulation in an ebullated bed process | |
| CA2003081C (en) | Liquid degaser in an ebullated bed process | |
| CA1251130A (en) | Ebullated bed reactor having top-mounted recycle pump | |
| US4406776A (en) | Fluidized catalytic cracking process and apparatus | |
| US4711766A (en) | Apparatus for mixing cracking catalyst with a fluid hydrocarbon | |
| US6486217B2 (en) | Throat and cone gas injector and gas distribution grid for slurry reactor (CJB-0004) | |
| US20030021738A1 (en) | Internal device for separating a mixture that comprises at least one gaseous phase and one liquid phase |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |