Exxon Research and Engineering Company

Willard N Mitchell

Stephen C Leviness

Edward L Wilson

Hermann E Von Rosenberg

J Robert Sims, Jr

Charles W Williamson

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

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

A fresh, reduced hydrocarbon synthesis catalyst is activated by contact with hydrogen at elevated temperatures and pressures and in the presence of liquid hydrocarbons, preferably, sufficient to immerse the catalyst therein.

Activation of hydrocarbon synthesis catalyst

A cobalt- or ruthenium-containing hydrocarbon synthesis catalyst, subjected to short term, reversible, partial deactivation in a slurry synthesis process can be rejuvenated, i.e., at least about 80+% catalyst activity recovery, by treating the catalyst in the presence of liquid hydrocarbons, preferably the slurry hydrocarbons, with hydrogen at elevated temperatures and pressures.

Rejuvenation of hydrocarbon synthesis catalyst

Improved liquid yields are obtained during the hydrogen-donor solvent liquefaction of coal and similar carbonaceous solids by maintaining a higher concentration of material having hydrogenation catalytic activity in the downstream section of the liquefaction reactor system than in the upstream section of the system.

Hydrogen-donor coal liquefaction process

Substantial and commercially important increases in polypropylene film production rates without adversely affecting film quality are obtained in a tubular water film process. The improvements comprise modifications in the die lip, in the mandrel air (fluid) slot affecting the cooling gas velocity, and in the upper bubble pressure control. The improvements are especially useful to obtain mill rolls 60 to 80 inches wide.

Process for tubular water-bath polypropylene films

In a fluidized bed process for the gasification of coal or similar carbonaceous solids wherein char particles are withdrawn from a fluidized bed reaction vessel, transported to a second vessel, and later returned to the initial vessel, char particles of high ash content are separated from particles to be returned to the fluidized bed reaction vessel by injecting a dense phase stream of char particles including particles of both high and low ash content into a vertically moving gas stream having a velocity sufficient to transport relatively light particles of low ash content upwardly into the fluidized bed reaction vessel but insufficient to suspend relatively dense particles of high ash content, collecting the high ash content particles which are not entrained by the gas stream, and periodically withdrawing the collected particles from the system.

Coal gasification ash removal system

Feed coal particles are mixed with fine particles of devolatilized carbonaceous material having an average particle diameter less than about 25% of that of the coal and then injected into a high temperature fluidized bed gasification zone. The devolatilized material adheres to the coal particles as they soften and forms a nonsticky coating which hinders the formation of large coal agglomerates. During the gasification process the adhering particles are retained in the bed and at least partially gasified, resulting in better carbon utilization than might otherwise be obtained.

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Ridgeland, MS, United States of America

Willard N Mitchell