Texaco Inc.

John C Strickland

Dorrance P Bunn, Jr

Robert M Steinberg

John P MacLean

Ting Y Chan

George K Perry

Douglas H May, Jr

Vijay Anant Deshpande

Dale Williams

Lalit S Shah

Edward K Liu

Jacquelyn Gayle Niccum

Internal components for a vertical downflow reactor include a closed-ended conduit having an internal baffle and longitudinal exit slots proximate its closed end for the symmetrical introduction of quench fluid into a quench zone. An interzone mixing configuration is in vertical communication with the bottom of the quench zone. An inwardly sloping collector tray has an opening concentric with the vertical axis of the reactor vessel. A mixing device is provided for mixing the liquid and vapor components entering from above the collector tray and conveying the mixed vapor and liquid downwardly through the opening. Flow deflectors are positioned immediately below the collector tray opening for directing liquid flow towards the axial centerline of the reactor. The flow deflectors take the form of four pie-shaped plates which are configured to collectively occupy between 25 to 75 percent of the concentric circular opening the collector tray and may slope downwardly at an angle of from about 30.degree. to about 60.degree. from the horizontal. A collection pan is positioned below and in axial alignment with the collector tray to capture and retain the liquid. A radially outwardly flared downwardly extending skirt is provided to disperse the liquid flowing from the collector pan toward the reactor walls. A continuous vertical spiral weir is provided on the surface of the collector tray to add residence time to the liquid on the tray for mixing of the liquid thereon.

Fluids mixing and distributing apparatus

Internal components for a vertical downflow reactor include a quench nozzle for the symmetrical introduction of a quench fluid into a quench zone. An interzone mixing configuration is in vertical communication with the bottom of the quench zone. An inwardly sloping collector tray has an opening concentric with the vertical axis of the reactor vessel. A mixing device is provided for mixing the liquid and vapor components entering from above the collector tray and conveying the mixed vapor and liquid downwardly through the opening. Flow deflectors are positioned immediately below the collector tray opening for directing liquid flow towards the axial centerline of the reactor. A collection pan is positioned below and in axial alignment with the collector tray to capture and retain the liquid. A radially outwardly flared downwardly extending skirt is provided to disperse the liquid flowing form the collector pan toward the reactor walls. A pair of continuous vertical spiral weirs is provided on the surface of the collector tray to add residence time to the liquid on the tray for mixing of the liquid thereon.

In an ebullated bed process for hydrotreating a distillate hydrocarbon feedstock it has been found that a catalyst addition slurry is made up with catalyst and feedstock. A control system provides for a constant distillate feedstock rate during intermittent catalyst addition.

Process and system for catalyst addition to an ebullated bed reactor

Internal components for a vertical downflow reactor include a closed-ended conduit having an internal baffle and longitudinal exit slots proximate its closed end for the symmetrical introduction of quench fluid into a quench zone. An interzone mixing configuration is in vertical communication with the bottom of the quench zone. An inwardly sloping collector tray has an opening concentric with the vertical axis of the reactor vessel. A mixing device is provided for mixing the liquid and vapor components entering from above the collector tray and conveying the mixed vapor and liquid downwardly through the opening. Flow deflectors are positioned immediately below the collector tray opening for directing liquid flow towards the axial centerline of the reactor. A collection pan is positioned below and in axial alignment with the collector tray to capture and retain the liquid. A radially outwardly flared downwardly extending skirt is provided to disperse the liquid flowing from the collector pan toward the reactor walls. A continuous vertical spiral weir is provided on the surface of the collector tray to add residence time to the liquid on the tray for mixing of the liquid thereon.

In an ebullated bed process the feedstock conduit is provided with at least 50 psi (4.4 atm) head in excess of a liquid-vapor separation pressure. The excess head is used in combination with an eductor to recycle a reactor effluent liquid. The expanded catalyst bed is thereby maintained at 110 vol % to vol % of a settled catalyst volume. A separate pump to expand (ebullate) the catalyst bed is not required.

Ebullated bed process with recycle eductor

In ebullated bed hydroprocessing of a distillate hydrocarbon feedstock, it has been found that high pressure and low pressure heat exchange can be separated. Both the high pressure heat exchange and the fired heater fuel consumption are reduced. A control system provides for a constant distillate feedstock temperature in cooperation with heat integration.

Ebullated bed hydroprocessing of petroleum distillates

The invention is an improvement in an ebullated bed process. Gas is removed from the vertically oriented reaction vessel until the vessel, including the recycle conduit is liquid filled. Foam, generated around the recycle cup and riser conduits is floated to the top of the reaction vessel by liquid and is prevented from entering the recycle conduit. A more stable hydrodynamic system is thereby achieved.

Controlling foam circulation in an ebullated bed process

A vortex breaker has been invented for a liquid draw off tray with horizontal liquid draw off. Liquid is removed from the sump of the tray horizontally through a port. A first vertically oriented baffle has a top edge above the port, a bottom edge below the port and a side edge adjacent the port. A second vertically oriented baffle is perpendicular to the first baffle. The second baffle has a top edge above the port and a bottom edge spaced from the sump bottom a distance to about one-half port diameter, allowing for the flow of liquid thereunder. The vortex breaker is useful for a liquid spare horizontal liquid draw off tray.

Vortex breaker for horizontal liquid draw off tray sump

The invention is an improvement in an ebullated bed process. Gas is removed the ebullated bed reactor preferentially to liquid. Gas is removed by material balance control until the reactor, including the recycle conduit is liquid full. Foam, generated around the recycle cup and riser conduits is floated upward by liquid and does not enter the recycle conduit. When steady state is achieved, liquid and gas are both removed from the reactor under material balance control.

Liquid inventory control in an ebullated bed process

An improved method of controlling catalyst inventory in the reactor of an ebullated bed process has been discovered. Pressure differentials are measured to calculate a catalyst inventory characterization factor. Aged catalyst is withdrawn and fresh catalyst added in an amount to reestablish the value of the factor. The catalyst to oil ratio is maintained despite changes in bed ebullation, gas and liquid holdups and oil residence time changes.

Catalyst inventory control in an ebullated bed process

A fluid catalytic cracking process and apparatus in which a plurality of hydrocarbon feedstocks including at least one normally gaseous paraffinic hydrocarbon feedstock and at least one normally liquid hydrocarbon feedstock are subjected to cracking reaction conditions in a common transport type reaction zone in the presence of a zeolite cracking catalyst. Fresh hot regenerated catalyst is first contacted with a normally gaseous paraffinic hydrocarbon under dehydrogenation reaction conditions effecting conversion to normally gaseous olefins, and fresh normally liquid cracking charge stock is contacted in the reaction zone under cracking reaction conditions with the gaseous paraffinic and olefinic hydrocarbons.

Catalytic cracking

In a fluidized catalytic cracking unit a riser discharge head for discharging catalyst and hydrocarbon vapor from a riser conduit substantially vertically downward into a vertical reaction vessel such that erosion of the discharge head and the reaction walls is avoided.

Apparatus for fluidized catalytic cracking

A temperature-sensitive instrument assembly for removable mounting within a vessel, flowline or the like including a flange plate for mounting onto a vessel or flowline nozzle; a hollow mounting tube mounted within and extending through the flange plate into the interior of the vessel, flowline nozzle or the like; a temperature-sensitive element positioned in and extending with the mounting tube into the interior of the vessel, flowline nozzle or the like, the mounting tube having an opening on the downstream side thereof to expose the temperature-sensitive element to fluid conditions within the vessel; and, a shield mounted on the mounting tube opposite from the mounting tube opening for protective positioning upstream of any fluid flow in the vessel, flowline nozzle or the like.

Instrument assembly

A process is described herein for regeneration of spent, coke contaminated fluidized cracking catalyst by burning coke therefrom with a molecular oxygen containing regeneration gas in a fluidized dense phase bed, and for burning substantially all carbon monoxide formed to carbon dioxide. A method is provided for supplying additional oxygen to a dilute phase above the dense phase bed for combustion of carbon monoxide. Additionally, a method is provided for transferring heat from the dilute phase back to the bottom of the fluidized dense phase bed.

Fluidized catalytic cracking regeneration process

Apparatus for regeneration of spent, coke contaminated fluidized cracking catalyst by burning coke therefrom with a molecular oxygen containing regeneration gas in a fluidized dense phase bed, and for burning substantially all carbon monoxide to carbon dioxide. Means are provided for transferring heat from the top to the bottom of the regeneration apparatus, employing catalyst as the transfer medium. Also, conical standpipe means is provided for deaerating regenerated catalyst.

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Houston, TX, United States of America

John C Strickland