Texaco Inc.

Ting Y Chan

John C Strickland

Henry C Chan

Edward K Liu

Vijay Anant Deshpande

James H Colvert

Michael M Dach

Robert M Steinberg

Lalit S Shah

George K Perry

Harold J Ayers

Doyun Kim

The invention is a method for mixing feedstock with fluidized catalyst in a fluid catalytic cracking (FCC) riser reactor. A dispersed catalyst suspension is passed upwardly at a velocity of 0.5 to 4 ft/sec. Atomized feedstock is injected downwardly at a velocity of -30 to -1000 ft./sec to produce a turbulently mixed reaction suspension. Vaporizing feedstock rapidly accelerates the reaction suspension in approximately plug flow. The slip factor between catalyst and hydrocarbon in the reaction suspension defining the departure from ideal plug flow is thereby reduced.

Fluid catalytic cracking feedstock injection process

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.

Fluids mixing and distributing apparatus

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 an ebullated bed process reactor effluent is subjected to high pressure followed by intermediate flash separation. An ebullation liquid is formed by educting high pressure flash separation liquid into an intermediate flash separation liquid. The ebullation liquid is recycled to the reactor to expand the catalyst bed to 110 vol % to 200 vol % of a settled catalyst bed volume. As a result of recycle pressure balance is advantageously maintained. Carry over catalyst and catalyst fines are recycled to the reactor and kept out of downstream equipment.

In a fluid catalytic cracking (FCC) process riser reactor effluent is rapidly separated into spent catalyst and hydrocarbon product. The separated hydrocarbon product is immediately quenched to an unreactive temperature in the absence of quenching spent catalyst. An increase in debutanized naphtha yield is achieved. By avoiding catalyst quenching, heat duty is saved in the catalyst regenerator.

FCC riser discharge separation and quench apparatus

A riser cyclone separator for rapidly separating catalyst from cracked hydrocarbon vapors in a fluid catalytic cracking process. The riser cyclone is provided with an annular port for drawing stripping gas into the riser cyclone to separate entrained catalyst and vent stripper gas from the regenerator vessel. The cyclone is inherently negative pressure to the reactor vessel.

Apparatus and process for withdrawing stripper gas from an FCC reactor

FCC riser discharge separation and quench

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. Two stages of cyclone separators effect the final liquid-vapor separation.

Liquid degasser 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

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. Helical members are positioned within the riser conduits which impart a tangential velocity component to the fluid. Cyclone separators effect the final liquid-vapor separation. Vapor is directed to a vapor rich zone in the reactor.

Liquid degaser in an ebullated bed process

A support assembly for the air distributor in the catalyst regenerator vessel of a fluid catalytic cracking apparatus is revealed. The support assembly comprises a primary support which fixedly connects the air distributor to the catalyst regenerator and a plurality of secondary rigid supports. The secondary rigid supports connect to both the air distributor and catalyst regenerator vessel with ball and socket joints. The support assembly allows for unrestricted multi directional thermal expansion of the air distributor without causing twisting or warping.

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Houston, TX, United States of America

Ting Y Chan