Exxon Research and Engineering Company

Min Chang

Constantine A Coulaloglou

Edward C Hsu

Charles John Mart

Charles W Degeorge

Larry E Pedrick

Stephen J Hsia

A gas distribution grid for a slurry reactor includes a plurality of gas injectors horizontally arrayed across, and extending through, an otherwise gas and liquid impervious plate. The injectors have a throat open at both ends, with a gas pressure reducing bore at one end which is the entrance end and with the other end opening into an upward opening cone. Flow diverting means in the injectors prevents slurry solids from entering the throat and being attrited by the high velocity gas jet exiting the bore into the throat. It is preferred that the gas injectors not protrude above the top surface of the grid and flat space is eliminated by means such as angular fillers, to prevent solids accumulation top of the grid. A chamfer may be present at the junction of the bore and throat to prevent unrestricted expansion of the gas jet entering the throat. This is useful for injecting gas into a reactive hydrocarbon synthesis slurry in a slurry reactor, with reduced catalyst attrition and deactivation.

Throat and cone gas injector and gas distribution grid for slurry reactor (LAW646)

Throat and cone gas injector and gas distribution grid for slurry reactor

A slurry hydrocarbon synthesis process with reduced catalyst attrition is achieved by injecting a synthesis gas comprising a mixture of H.sub.2 and CO up into the reactive slurry with a gas distribution grid having gas injectors horizontally arrayed across, and vertically extending through, an otherwise gas and liquid impervious plate. The injectors have a throat with a gas pressure reducing orifice at one end, which is the bottom and gas entrance end, and the other end opening into an open cone in which the uprising gas contacts the slurry. Flow diverting means in the injectors prevents slurry from entering the throat and being attrited. The gas injectors do not protrude above the top surface of the plate and flat space is eliminated by means such as angular fillers, to prevent solids accumulation top of the tray.

Slurry hydrocarbon synthesis with reduced catalyst attrition and

A reversibly deactivated hydrocarbon synthesis catalyst in a hydrocarbon synthesis slurry is rejuvenated by successively passing the slurry through at least two rejuvenation stages external of the slurry reactor, each of which comprises a rejuvenation zone followed by an offgas removal zone. This is accomplished by using a lift pipe outside the reactor into which slurry from the reactor is passed and contacts a catalyst rejuvenating gas to partially rejuvenate the catalyst particles and form a rejuvenation offgas. The gas and slurry mixture are passed into a vessel in which the gas is removed from the slurry. Rejuvenation gas is bubbled into the slurry in the vessel to further rejuvenate the catalyst. A gas removing downcomer removes gas from the slurry in the vessel before it is passed back into the reactor. The rejuvenation gas also acts as a lift gas in the lift pipe.

Slurry hydrocarbon synthesis process with multistage catalyst

A reversibly deactivated, particulate catalyst in a hydrocarbon synthesis slurry is rejuvenated by circulating the slurry from a slurry body through (i) a gas disengaging zone to remove gas bubbles from the slurry and increase its density, (iii) a downcomer which feeds the gas reduced, dense slurry into the bottom of a rejuvenating tube and applies a positive hydrostatic pressure to the tube, (iii) a catalyst rejuvenation zone in which a catalyst rejuvenating gas, which also acts as a lift gas, contacts the catalyst in slurry to form a catalyst rejuvenated slurry and, (iv) back into the slurry body. Removing gas bubbles prior to rejuvenation improves the rejuvenation efficiency and the downcomer reduces the amount of rejuvenation gas required to maintain slurry circulation through the tube.

Combination gas disengaging downcomer-rejuvenation tube for in-situ

A slurry hydrocarbon synthesis process employs a slurry filtration vessel external of the slurry reactor. Slurry from the reactor is passed through one or more gas and solids disengaging zones, one or more of which may be present in the reactor and vessel, to reduce the gas and solids content of the slurry before it contacts the filter in the vessel. The filter separates the slurry hydrocarbon liquid from the gas and solids as a filtrate which is sent to upgrading. Valves in gas and fluid conduits enable the filtration vessel to be isolated from the reactor for maintenance, to replace filters and to aid in controlling slurry flow through the vessel. A hydrogen rich gas may be injected into the filtration vessel to prevent catalyst deactivation. Slurry is hydraulically circulated between the reactor and vessel due to density differences while the reactor is operating.

Slurry hydrocarbon synthesis with external product filtration

Slurry bubble columns equipped with downcomers which have high efficiency gas disengagement means fitted on top of the slurry liquid reaction mixture comprising an inverted channel having a gas vent extending out of the apex of the inverted channel and a liquid by-pass pipe extending from the side of the inverted channel at a point below the apex to under the liquid level and emptying into the downcomer. The inverted channel is fitted to the top of said downcomer and the bottom edge of which inverted channel is in contact with the surface of the slurry mixture in the slurry bubble column reaction zone. Improved catalyst distribution and circulation, mass and heat transfer results from catalyst in gas-lean slurry flowing through the liquid by-pass tubes in the inverted channel and flowing into and down the downcomer to the bottom of the bubble column reactor. Hydrogen or any rejuvenating gas can be introduced into the bottom of the downcomer to restore catalyst activity as the catalyst moves down the downcomer.

Enhanced gas separation for bubble column draft tubes

Catalyst particle distribution and mixing in slurry part of bubble columns is improved by introducing a secondary suspending fluid into the columns at locations within the lower 20% of the vertical height of the column but above the gas distributor normally located at or near the bottom of the columns.

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Warren, NJ, United States of America

Min Chang