Process for the desulfurization of heavy oils and bitumens
AssigneeExxonMobil Research and Engineering Company
InventorsMichael Siskin, Rustom M. Billimoria, David W. Savage, Roby Bearden, JR.
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Abstract
The present invention relates to a process for desulfurizing bitumen and other heavy oils such as low API gravity, high viscosity crudes, tar sands bitumen, or shale oils with alkali metal compounds under conditions to promote in-situ regeneration of the alkali metal compounds. The present invention employs the use of superheated water and hydrogen under conditions to improve the desulfurization and alkali metal hydroxide regeneration kinetics at sub-critical temperatures.
Claims28
A process for removing sulfur from a sulfur-containing heavy oil feedstream, comprising:
- a) contacting a sulfur-containing heavy oil feedstream with a hydrogen-containing gas and potassium hydroxide in a superheated water solution in a reaction zone to produce a reaction effluent stream;
- b) separating the reaction effluent stream into a degassed effluent stream and an overhead light gas stream;
- and
- c) conducting at least a portion of the degassed effluent stream to an initial gravity settler, thereby producing a desulfurized heavy oil product stream and an initial potassium salts solution;
- wherein the reaction zone is operated at temperature from about 482° F. to about 698° F. (250 to 370° C.) and a pressure of about 600 to about 3000 psig (4,137 to 20,684 kPa) and the sulfur content of the desulfurized heavy oil product stream is at least 35 wt % lower than the sulfur content of the sulfur-containing heavy oil feedstream.
A process for removing sulfur from a sulfur-containing heavy oil feedstream, comprising:
- a) contacting a sulfur-containing heavy oil feedstream with a hydrogen-containing gas and potassium hydroxide in a superheated water solution in a reaction zone to produce a reaction effluent stream;
- b) separating the reaction effluent stream into a degassed effluent stream and an overhead light gas stream;
- c) conducting at least a portion of the degassed effluent stream to an initial gravity settler, thereby producing a desulfurized heavy oil product stream and an initial potassium salts solution;
- and
- d) conducting at least a portion of the initial potassium salts solution to a second gravity settler, wherein the second gravity settler is operated at a temperature from about 212 to about 482° F. (100 to 250° C.), thereby producing an asphaltene-rich hydrocarbon stream and a second potassium salts solution;
- wherein the reaction zone is operated at temperature from about 482° F. to about 698° F. (250 to 370° C.) and a pressure of about 600 to about 3000 psig (4,137 to 20,684 kPa) and the sulfur content of the desulfurized heavy oil product stream is at least 35 wt % lower than the sulfur content of the sulfur-containing heavy oil feedstream.
A process for removing sulfur from a sulfur-containing heavy oil feedstream, comprising:
- a) contacting a sulfur-containing heavy oil feedstream with a hydrogen-containing gas and potassium hydroxide in a superheated water solution in a reaction zone to produce a reaction effluent stream;
- b) separating the reaction effluent stream into a degassed effluent stream and an overhead light gas stream;
- and
- c) conducting at least a portion of the degassed effluent stream to an initial gravity settler wherein the initial gravity settler is operated at a temperature from about 212 to about 482° F. (100 to 250° C.), thereby producing an asphaltene-containing aqueous solution stream and an intermediate desulfurized heavy oil product stream;
- wherein the reaction zone is operated at temperature from about 482° F. to about 698° F. (250 to 370° C.) and a pressure of about 600 to about 3000 psig (4,137 to 20,684 kPa) and the sulfur content of the intermediate desulfurized heavy oil product stream is lower than the sulfur content of the sulfur-containing heavy oil feedstream.
Dependencies are inferred from the claim text.