Exxonmobil Research and Engineering Company

Exxon Research and Engineering Company

Janet Renee Clark

Robert J Wittenbrink

Michel A Daage

Russell John Koveal

Charles John Mart

Jennifer Schaefer Feeley

Thomas R Halbert

Daniel Francis Ryan

Garland B Brignac

William C Baird, Jr

Charles H Mauldin

Kenneth L Riley

Stephen M Davis

Bruce R Cook

Michele Sue Touvelle

Richard A Demmin

Albert Edward Schweizer

John P Greeley

David O Marler

Albert E Schweizer

Craig A McKnight

Robert Jay Wittenbrink

David Owen Marler

Charles Harrison Mauldin

There is provided a process for renewing the activity of supported metal catalysts for the hydrogenation of carbon monoxide to form a mixture of hydrocarbons comprising decreasing the hydrocarbon content of the catalyst, preferably by contact with hydrogen-containing gas at elevated temperatures, impregnating under a non-oxidizing atmosphere with a solution of at least one of an ammonium salt and an alkyl ammonium salt, optionally in combination with up to five moles of ammonia per liter of solution to the point where it has absorbed a volume of solution equal to at least about 10% of its calculated pore volume; oxidizing the catalyst with a gaseous oxidant in the presence of the impregnating solution and activating the catalyst by reduction with hydrogen at elevated temperatures. Optionally, the catalyst is calcined after the oxidation step, and passivated after the activation step.

Supported catalyst treatment

A process for enhancing metal catalysts for carbon monoxide hydrogenation comprising reducing the catalyst so that at least a portion is in the metallic state, impregnating under a non-oxidative atmosphere with a solution of a salt of at least one metal, optionally in combination with at least one of an ammonium salt, an alkyl ammonium salt, a weak organic acid and ammonia, oxidizing with a gaseous oxidant in the presence of the impregnating solution, and reducing to form an active catalyst. Used catalysts enhanced by the process are initially treated to decrease their hydrocarbon content. The treatment may be carried out in a single reactor, or by carrying out up to all steps after catalyst may be withdrawn from a reactor and returned to at least one reactor, both preferably during operations. Up to all steps may be effected in a subsequent reactor, or in specialized apparatus.

Catalyst enhancement

A process for activating a supported metal catalyst or catalyst precursor useful for the hydrogenation of carbon monoxide to form a mixture of hydrocarbons, comprising reducing with a hydrogen-containing gas at elevated temperature so that at least a portion is in the metallic state, impregnating under a non-oxidizing atmosphere with a solution of at least one member selected from the group consisting of ammonium salts, alkyl ammonium salts and weak organic acids, optionally further including ammonia, to the point where it has absorbed a volume of solution equal to at least about 10% of its calculated pore volume, oxidizing with a gaseous oxidant in the presence of the impregnating solution and reducing with hydrogen-containing gas at elevated temperatures to form an active catalyst. The steps beginning with the impregnation may be repeated. Optionally, the catalyst may be calcined after the oxidation step and/or passivated after activation.

Supported catalyst activation

There is provided a process for renewing the activity of used, supported metal catalysts for the hydrogenation of carbon monoxide to form a mixture of hydrocarbons comprising decreasing the hydrocarbon content of the catalyst, impregnating said catalyst under an non-oxidative atmosphere with a solution at least one weak organic acid, preferably a mono- or di-carboxylic acid, to the point where it has absorbed a volume of said solution equal to at least about 10% of its calculated pore volume, oxidizing the catalyst with a gaseous oxidant in the presence of the impregnating solution and activating the catalyst by reduction with hydrogen at elevated temperatures. Optionally, the catalyst is calcined after the oxidation step, and passivated after the activation step. A preferred means of decreasing the hydrocarbon content of the catalyst is contacting it with a hydrogen-containing gas at elevated temperatures.

Supported catalyst regeneration

A slurry Fischer-Tropsch hydrocarbon synthesis process for synthesizing liquid hydrocarbons from synthesis gas in a synthesis reactor also hydroisomerizes the synthesized hydrocarbon liquid, which comprises the slurry liquid, in one or more lift reactors immersed in the slurry body in the synthesis reactor. A monolithic catalyst is preferably used for the hydroisomerization, and slurry circulation up through the lift reactors from the surrounding slurry body, is achieved at least in part by the lift action of the hydroisomerization treat gas. Preferably, catalyst particles are also removed before the slurry contacts the catalyst. Hydroisomerization occurs while the synthesis reactor is producing hydrocarbons, without interfering with the synthesis reaction. A gas bubble reducing downcomer may be used to produce and feed the gas bubble reduced slurry into the lift reactor, thereby providing a hydraulic head assist in the slurry circulation up through and out of the lift reactor.

Slurry hydrocarbon synthesis with liquid hydroisomerization in the synthesis reactor

A slurry Fischer-Tropsch hydrocarbon synthesis process for synthesizing liquid hydrocarbons from synthesis gas in a synthesis reactor also hydroisomerizes the synthesized hydrocarbons in one or more external lift reactor hydroisomerizing loops outside of the reactor, but which are a part of the reactor. A monolithic catalyst is used for the hydroisomerization and slurry circulation between the synthesis reactor and one or more loops is achieved, at least in part, by the lift action of a hydrogen treat gas injected into each loop.

Slurry hydrocarbon synthesis with isomerization zone in external lift reactor loop

A slurry Fischer-Tropsch hydrocarbon synthesis process for synthesizing liquid hydrocarbons from synthesis gas, in a hydrocarbon synthesis reactor, also hydroisomerizes the synthesized hydrocarbons in one or more external downcomer reactor hydroisomerizing loops outside of the reactor, but which are a part of the synthesis reactor. A monolithic catalyst is used for the hydroisomerization, and slurry circulation between the synthesis reactor and the one or more hydroisomerization loops is achieved, at least in part, by density-difference driven hydraulics created by removing gas bubbles from the slurry passed into the loop. Preferably, catalyst particles are also removed before the slurry contacts the monolithic hydroisomerization catalyst.

Slurry hydrocarbon synthesis with external hydroisomerization in downcomer reactor loop

A slurry Fischer-Tropsch hydrocarbon synthesis process for synthesizing liquid hydrocarbons from synthesis gas in a hydrocarbon synthesis reactor also hydroisomerizes the synthesized hydrocarbon liquid, which comprises the slurry liquid, in one or more downcomer reactors immersed in the slurry body in the synthesis reactor. A monolithic catalyst is preferably used for the hydroisomerization, and slurry circulation down through the downcomer reactors from the surrounding slurry body, is achieved at least in part by density-difference driven hydraulics created by removing gas bubbles from the slurry passed into the downcomers. Preferably, catalyst particles are also removed before the slurry contacts the catalyst. Hydroisomerization occurs while the synthesis reactor is producing hydrocarbons, without interfering with the hydrocarbon synthesis reaction.

In-situ hydroisomerization of synthesized hydrocarbon liquid in a slurry fischer-tropsch reactor

Naphtha desulfurization with reduced product mercaptans is achieved by reacting a naphtha feed containing sulfur compounds and olefins with hydrogen in the presence of a hydrosesulfurization catalyst at reaction conditions including a temperature of from 290-425&deg; C., a pressure of from 60-150 psig, and a hydrogen gas ratio of from 2000-4000 scf/b. It has been found that desulfurizing within these narrow conditions permits deep desulfurization with reduced mercaptan reversion, to produce a naphtha product with low total sulfur and low mercaptan sulfur levels.

Naphtha desulfurization with reduced mercaptan formation

A high VI and low pour point lubricant base stock is made by hydroisomerizing a high purity, waxy, paraffinic Fischer-Tropsch synthesized hydrocarbon fraction having an initial boiling point in the range of 650-750&deg; F., followed by catalytically dewaxing the hydroisomerate using a dewaxing catalyst comprising a catalytic platinum component and an H-mordenite component. The hydrocarbon fraction is preferably synthesized by a slurry Fischer-Tropsch using a catalyst containing a catalytic cobalt component. This combination of the process, high purity, waxy paraffinic feed and the Pt/H-mordenite dewaxing catalyst, produce a relatively high yield of premium lubricant base stock.

Isoparaffinic base stocks by dewaxing fischer-tropsch wax hydroisomerate over Pt/H-mordenite

Nickel-copper catalysts supported on an amorphous silica-alumina acidic carrier, preferably containing a binder, and having an iso-electric point of &gE;6.5 are used to hydroisomerize paraffins, particularly Fischer-Tropsch paraffins, boiling at 350&deg; F.&plus; into lighter, more valuable products.

Supported Ni-Cu hydroconversion catalyst

A high temperature naphtha desulfurization process with reduced olefin saturation employs a partially spent and low metals content hydrodesulfurization catalyst having from 2-40% the activity of a new catalyst. The catalytic metals preferably include Co and Mo in an atomic ratio of from 0.1 to 1. The catalyst is preferably at least partially regenerable, has less than 500 wppm of a total of one or more of nickel, iron and vanadium and preferably has no more than 12 wt. % catalytic metal calculated as the oxide. This permits selective deep desulfurization, with reduced olefin saturation, low product mercaptan levels and little or need for downstream mercaptan removal.

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Baton Rouge, LA, United States of America

Janet Renee Clark