Exxon Research and Engineering Company

Stephen C Leviness

William C Behrmann

Willard N Mitchell

Charles John Mart

Rocco A Fiato

Russell J Koveal

Richard Frank Bauman

Charles W Degeorge

Stephen J Hsia

Daniel Ray Neskora

A slurry catalytic hydrocarbon synthesis process which employs a catalyst comprising a supported cobalt component achieves a short term catalyst half life of more than 10 days, by using a syngas feed which contains less than fifty parts per billion of a combined total amount of HCN and NH,.

Slurry hydrocarbon synthesis process with increased catalyst life

A downcomer for producing at least two slurries having different solids and gas concentrations from a single three phase slurry of particulate solids and gas bubbles in a slurry liquid has two or more concentric gas and solids disengaging zones, each having an open fluid conduit depending from an orifice in the bottom. The downcomer is useful in a slurry hydrocarbon synthesis process for forming a catalyst and gas reduced slurry which is passed to a liquid filter to remove hydrocarbon liquid from the slurry reactor.

Multizone downcomer for slurry hydrocarbon synthesis process

Cyanide and ammonia are removed from a gas, such as a synthesis gas, by catalytically hydrolyzing cyanide in the gas to ammonia, water scrubbing the hydrolyzed gas to dissolve ammonia and at least a portion of remaining cyanide, and optionally, contacting the scrubbed gas with an adsorbent for cyanide and ammonia to form a clean gas containing less than 50 vppb of a combined total of cyanide and ammonia. The clean synthesis gas is then fed into a hydrocarbon synthesis reactor wherein it produces hydrocarbons with substantially reduced catalyst deactivation and cleaner hydrocarbon products.

Cyanide and ammonia removal from synthesis gas

Partially deactivated catalyst in a slurry hydrocarbon synthesis process is rejuvenated employing a cyclic rejuvenation process in which syngas or CO flow into the slurry is stopped to stop the hydrocarbon synthesis reaction, the CO purged out of the slurry with a purge gas in the presence of hydrogen, the catalyst rejuvenated with a hydrogen containing rejuvenating gas and the hydrocarbon synthesis reaction restarted by passing the synthesis gas feed back into the reactor. All or a portion of the purge gas and/or the rejuvenating gas may be recycled during the respective purge and/or rejuvenation. The hydrogen required during the purge is typically part of the purge gas.

Slurry hydrocarbon synthesis with cyclic co purge and catalyst

A reversibly deactivated, particulate catalyst in a slurry 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, (ii) a catalyst rejuvenation zone in which a catalyst rejuvenating gas contacts the catalyst in the slurry to rejuvenate it and form a rejuvenated catalyst slurry and, (iii) back into the slurry body. Removing at least a portion of the gas bubbles improves the rejuvenation process.

Hydrocarbon synthesis catalyst slurry rejuvenation with gas

A downcomer for producing at least two slurries having different solids and gas concentrations from a single three phase slurry of particulate solids and gas bubbles in a slurry liquid has two or more concentric gas and solids disengaging zones, each having an open fluid conduit depending from an orifice in the bottom. The dowwncomer is useful in a slurry hydrocarbon synthesis process for forming a catalyst and gas reduced slurry which is passed to a liquid filter to remove hydrocarbon liquid from the slurry reactor.

Multizone downcomer for slurry hydrocarbon syntheses process

Hydrogen containing tail gas from a hydrocarbon synthesis reactor is used as a hydrogen containing catalyst rejuvenating gas. If CO is present, the CO content, is less than 10 mole % of the gas and the H.sub.2 to CO mole ratio is greater than 3:1. At least a portion of the water and liquid hydrocarbons are removed from the tail gas, before it is used to rejuvenate the reversibly deactivated catalyst.

Hydrocarbon synthesis using reactor tail gas for catalyst rejuvenation

Hydrocarbon synthesis catalyst slurry rejuvenation with gas disengagement

Slurry hydrocarbon synthesis with cyclic CO purge and catalyst

A reversibly deactivated, particulate catalyst in a hydrocarbon synthesis slurry is rejuvenated by circulating the slurry from a slurry body through a rejuvenation zone in which hydrogen contacts the slurry and rejuvenates the catalyst to form a rejuvenated catalyst slurry and an offgas which contains catalyst deactivating species. The offgas is separated and removed from the rejuvenated slurry before it is passed back into the slurry body. This avoids or minimizes contamination and recontamination of the slurry body with the deactivating species produced by the rejuvenation process.

Catalyst rejuvenation in hydrocarbon synthesis slurry with reduced

Hydrocarbon liquid products are filtered and removed from a three phase hydrocarbon synthesis slurry comprising gas bubbles and particulate catalyst solids in a hydrocarbon liquid, by circulating the slurry through a gas disengaging downcomer immersed in the slurry to a filtration zone external or internal of the reactor, and then back into the slurry in the reactor. The gas disengagement densifies the slurry which is passed across the filtration surface under high flow conditions, to reduce solids build up on the filter as filter cake. Circulation through the filtration zone occurs by gravity and hydrostatics due to slurry density differences. The downcomer may also be a gas and solids reducing downcomer.

Slurry hydrocarbon synthesis with downcomer fed product filtration

Catalyst in a slurry phase reactor is rejuvenated in said reactor using a substantially vertical draft tube fully immersed in the slurry which utilizes a rejuvenating gas injected substantially near the bottom of the substantially vertical draft tube whereby catalyst near the bottom of the slurry phase reactor is drawn up the draft tube and discharged from the top of the draft tube near the top of the slurry phase in said reactor, control over the rejuvenation temperature in the substantially vertical draft tube being achieved by means of insulating the draft tube and/or fitting the draft tube with heating or cooling means.

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Baton Rouge, LA, United States of America

Stephen C Leviness