Hydrocarbon synthesis using reactor tail gas for catalyst rejuvenation
AssigneeExxon Research & Engineering Co.
InventorsRichard F. Bauman, Charles W. DeGeorge, Rocco A. Fiato, Stephen C. Leviness
Life of this patent
Estimating the term…
Abstract
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.
Claims37
A process for rejuvenating a reversibly deactivated hydrocarbon synthesis catalyst which comprises contacting said catalyst with a rejuvenating gas comprising hydrocarbon synthesis reactor tail gas containing H.sub.2, CO and one or more diluents.
A hydrocarbon synthesis process which comprises reacting a synthesis gas comprising a mixture of H.sub.2 and CO, in the presence of a hydrocarbon synthesis catalyst and one or more catalyst deactivating species, in at least one stage and at reaction conditions effective to form hydrocarbons from said gas and wherein said deactivating species at least partially reversibly deactivate said catalyst during said synthesis reaction, followed by contacting said reversibly deactivated catalyst with a catalyst rejuvenating gas comprising tail gas comprising H.sub.2 and CO in which the H.sub.2 to CO mole ratio is greater than 3:1 to at least partially rejuvenate said catalyst, said tail gas having been obtained from a hydrocarbon synthesis reactor operated at less than 100% CO conversion using a synthesis gas feed in which the H.sub.2 to CO mole ratio is greater than stoichiometric to produce said tail gas containing H.sub.2 and CO, along with water vapor and gaseous hydrocarbons and in which the H.sub.2 to CO mole ratio is greater than 3:1 and from which at least a portion of said water vapor and hydrocarbons have been removed.
A slurry Fischer-Tropsch hydrocarbon synthesis process for producing hydrocarbons from a synthesis gas feed in at least two reaction stages which operate at less than 100% CO conversion, said feed gas for each stage comprising a mixture of H.sub.2 and CO in which the H.sub.2 to CO mole ratio is greater than stoichiometric and wherein said H.sub.2 and CO are reacted in each stage in the presence of one or more catalyst deactivating species and a hydrocarbon synthesis catalyst in a slurry at reaction conditions effective to form hydrocarbons from said feed gas, at least a portion of which are liquid at said reaction conditions, wherein said slurry comprises said catalyst and gas bubbles in a hydrocarbon slurry liquid comprising said synthesized liquid hydrocarbons, wherein said species reversibly deactivate said catalyst and form a deactivated catalyst slurry during said reaction, wherein unreacted H.sub.2 and CO along with gaseous reaction products are removed from each stage as tail gas in which the H.sub.2 :CO mole ratio is greater than that in the feed gas for that stage, wherein said tail gas comprises the synthesis gas feed for the next successive stage, and wherein the H.sub.2 to CO mole ratio in the last stage tail gas is greater than 3:1, said process further comprising:
- (a) passing said last stage tail gas back to the first stage, and
- (b) contacting said first stage deactivated catalyst slurry with said last stage tail gas to at least partially rejuvenate said catalyst in said slurry and form a catalyst rejuvenated slurry.
Dependencies are inferred from the claim text.