Chevron U.s.a. Inc.

Chevron Research & Technology Company

Other

Chevron Research Company

James T McCall

David C Kramer

Robert W Bachtel

Bruce E Stangeland

David S Smith

Georgieanna L Scheuerman

David R Johnson

Georgieanne L Scheuerman

This invention makes possible substantially continuous flow of uniformly distributed hydrogen and hydrocarbon liquid across a densely packed catalyst bed to fill substantially the entire volume of a reactor vessel by introducing the fluids as alternate annular rings of gas and liquid (i.e. a mixture of liquid hydrocarbon and a hydrogen-containing gas) at a rate insufficient to levitate or ebullate the catalyst bed. Catalyst are selected by density, shape and size at a design feed rate of liquids and gas to prevent ebullation of the packed bed at the design feed rates. Catalysts are selected by measuring bed expansion, such as in a large pilot plant run, with hydrocarbon, hydrogen, and catalyst at the design pressures and flow velocities. The liquid and gas components of the feed flow into the bed in alternate annular rings across the full area of the bed. At the desired flow rate, such catalyst continually flows in a plug-like manner downwardly through the reactor vessel by introducing fresh catalyst at the top of the catalyst bed by laminarly flowing such catalyst in a liquid stream on a periodic or semicontinuous basis. Catalyst is similarly removed by laminarly flowing catalyst particles in a liquid stream out of the bottom of the catalyst bed. Intake for such flow is out of direct contact with the stream of gas flowing through the bed and the flow path is substantially constant in cross-sectional area and greater in diameter by several times than the diameter of the catalyst particles. The catalyst of this invention produces a plug-flowing substantially packed bed of hydroprocessing catalyst which occupies at least about 75% by volume of the reactor volume.

Catalyst, method and apparatus for an on-stream particle replacement

Catalyst method and apparatus for an on-stream particle replacement

This invention makes possible substantially continuous flow of uniformly distributed hydrogen and hydrocarbon liquid across a densely packed catalyst bed to fill substantially the entire volume of a reactor vessel by introducing the fluids as alternate annular rings of gas and liquid (i.e. a mixture of liquid hydrocarbon and a hydrogen-containing gas) at a rate insufficient to levitate or ebullate the catalyst bed. Catalyst are selected by density, shape and size at a design feed rate of liquids and gas to prevent ebullation of the packed bed at the design feed rates. Catalysts are selected by measuring bed expansion, such as in a large pilot plant run, with hydrocarbon, hydrogen, and catalyst at the design pressures and flow velocities. The liquid and gas components of the feed flow into the bed in alternate annular rings across the full area of the bed. At the desired flow rate, such catalyst continually flows in a plug-like manner downwardly through the reactor vessel by introducing fresh catalyst at the top of the catalyst bed by laminarly flowing such catalyst in a liquid stream on a periodic or semicontinuous basis. Catalyst is similarly removed by laminarly flowing catalyst particles in a liquid stream out of the bottom of the catalyst bed.

On-stream catalyst replacement hydroprocessing method wherein an upstream mixture of hydrogen and hydrocarbon liquid counter flows through a downwardly moving bed of hydroprocessing catalyst in a reactor vessel. The mixed feed stream of hydrogen and liquid hydrocarbon components enters a surge zone between the lower end of the reactor and a plenum zone to form a common pool under a conical support for the lower end of the downflowing catalyst bed. The mixed feed enters the plenum chamber through a plurality of passageways extending downwardly from the plenum zone to the same depth adjacent the lower end of the surge zone so that the liquid component normally prevents hydrogen from establishing independent paths before entering the plenum zone. Separation of the hydrogen and hydrocarbon liquid components from the mixed feed is thus assured to occur in the plenum zone directly below the pervious conical support to form a plurality of stepped concentric local reservoir rings under the conical support. Such rings are spaced apart sufficiently to create adjacent and alternate separate feed rings of hydrogen and hydrocarbon liquid. The depth of the lower end of each ring is intermediate the depth of the two radially adjacent concentric rings to maintain uniform feed of hydrogen and hydrocarbon liquid across the full cross-sectional area of the downflowing catalyst particles.

Method of hydroprocessing

On-stream catalyst replacement apparatus for countercurrent upstream flow of a gas and hydrocarbon liquid through a downward moving catalyst bed in a reactor vessel. A mixed feed stream of gas and liquid hydrocarbon components enters a reservoir formed between the lower end of the reactor and a conical screen supporting the lower end of a catalyst bed. A wall across the vessel divides the reservoir into a lower surge chamber for receiving the mixed feed and an upper plenum chamber for separating the components into alternate feed rings of gas and hydrocarbon liquid under the conical screen. The mixed feed enters the plenum chamber through a plurality of tubes extending downwardly from the wall to the same depth in the surge chamber that prevents establishing preferential paths for gas to independently enter the plenum chamber. Excessive separation of the gas and liquid components from the mixed feed in the plenum chamber is prevented by use of a plurality of concentric baffles abutting the underside of the conical screen and which are closely spaced apart only sufficient to create adjacent and alternate feed rings of gas and liquid. The depth of the lower end of each baffle is intermediate the depth of the two radially adjacent concentric baffles. Catalyst is continuously or periodically added to, or removed from, the vessel through tubing and a full-bore valve having uniform diameters throughout their lengths to maintain laminar flow of catalyst to or from a pressurizable hopper vessel.

Apparatus for an on-stream particle replacement system for

This invention makes possible substantially continuous flow of uniformly distributed hydrogen and hydrocarbon liquid across a densely packed catalyst bed to fill substantially the entire volume of a reactor vessel by introducing the fluids as alternate annular rings of gas and liquid at a rate insufficient to levitate the bed and with catalyst selected by a density, shape and size at a design feed rate of liquids and gas to prevent ebulation of the packed bed at the design feed rates. Catalysts are selected by measuring bed expansion in a large pilot plant run with hydrocarbon, hydrogen, and catalyst at the design pressures and flow velocities. The liquid and gas components of the feed flow into the bed in alternate annular rings across the full area of the bed. At the desired flow rate, such catalyst continually flows in a plug-like manner downwardly through the vessel by introducing fresh catalyst at the top of the bed by laminarly flowing such catalyst in a liquid stream on a periodic or semicontinuous basis. Catalyst is similarly removed by laminarly flowing catalyst particles in a liquid stream out of the bottom of the bed. Intake for such flow is out of direct contact with the stream of gas flowing through the bed and the flow path is substantially constant in cross-sectional area and greater in diameter by several times than the diameter of the catalyst particles.

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Baton Rouge, LA, United States of America

James T McCall