Hydrocracking of heavy hydrocarbon oils with improved gas and liquid distribution

• US 6,517,706 B1
• Filed: 05/01/2000
• Issued: 02/11/2003
• Est. Priority Date: 05/01/2000
• Status: Active Grant

• Current Assignee: Her Majesty The Queen In Right Of Canada As Represented By The Minister Or Natural Resources
• Original Assignee: Petro-Canada (Suncor Energy Incorporated)
• Inventors: Pruden, Barry B., Benham, N. Kelly
• Primary Examiner(s): GRIFFIN, WALTER DEAN
• Application Number:
  US09/561,942
• Time in Patent Office: 1,016 Days
• Field of Search: 208/108,158 422/214,215
• US Class Current: 208/108
• CPC Class Codes: C10G 47/26 suspended in the oil, e.g. slurries

Abstract

A slurry feed of a heavy hydrocarbon feedstock and coke-inhibiting additive particles together with a hydrogen-containing gas, are fed upward through a confined hydrocracking zone in a vertical, elongated, cylindrical vessel with a generally dome-shaped bottom head. A mixed effluent is removed from the top containing hydrogen and vaporous hydrocarbons and liquid heavy hydrocarbons. The slurry feed mixture and a portion of the hydrogen-containing gas are fed into the hydrocracking zone through an injector at the bottom of the dome-shaped bottom head and the balance of the hydrogen-containing gas is fed into the hydrocracking zone through injection nozzles arranged within of the hydrocracking zone at a location above the slurry-feed injector. The combined slurry feed and hydrogen-containing gas are injected at a velocity whereby the additive particles are maintained in suspension throughout the vessel and coking reactions are prevented.

Claims

1. A process for hydrocracking a heavy hydrocarbon oil which comprises passing (a) a slurry feed comprising a mixture of a heavy hydrocarbon oil feedstock a substantial proportion of which boils above 524°

C. and from about 0.01-4.0% by weight (based on fresh feedstock) of coke-inhibiting additive particles having an average size of less than about 30 μ

m and (b) a hydrogen-containing gas, upward through a confined hydrocracking zone in a vertical, elongated, cylindrical vessel with a dome-shaped bottom head, said hydrocracking zone being maintained at a temperature between about 350°

C. and 600°

C. and a pressure of at least 3.5 MPa and removing from the top of the hydrocracking zone a mixed effluent containing a gaseous phase comprising

hydrogen and vaporous hydrocarbons and a liquid phase comprising heavy hydrocarbons,

wherein the slurry feed mixture and a portion of the hydrogen-containing gas are fed into the hydrocracking zone through a feed injector at the bottom of the dome-shaped bottom head and the balance of the hydrogen-containing gas is fed into the hydrocracking zone through a plurality of injection nozzles arranged within the hydrocracking zone at a location above the slurry-feed injector, with the temperature of the hydrogen-containing gas entering through the nozzles being at a temperature higher than the temperature of the combined slurry feed and hydrogen-containing gas entering through said bottom feed injector and the combined slurry feed and hydrogen-containing gas entering through the bottom feed injector at a velocity of at least 5 m/s whereby the additive particles are maintained in suspension throughout the vessel and coking reactions are prevented.

2. A process according to claim 1 wherein the hydrogen containing gas being fed to the hydrocracking zone is a process recycle gas stream containing hydrogen.

3. A process according to claim 1 wherein the hydrogen-containing gas being fed to the injection nozzles has a temperature in the range of about 450 to 600°

C. and the combined slurry feed and hydrogen-containing gas being fed in through the bottom feed injector has a temperature in the range of about 300 to 430°

C.

4. A process according to claim 1 wherein the hydrogen injection nozzles are arranged in a lower, axial circular array having a diameter less than one half the diameter of the vessel and a higher, axial circular array adjacent the outer wall of the vessel.

5. A process according to claim 4 wherein the lower nozzles are within the dome-shaped bottom head and the higher nozzles are in the region of the bottom end of the cylindrical portion of the vessel.

6. A process according to claim 5 wherein a majority of the higher nozzles are directed upwardly, with the remainder directed downwardly and inwardly.

7. A process according to claim 6 wherein the upwardly directed nozzles are tilted inwardly from the vessel walls by an angle of up to about 6°

and the downwardly and inwardly directed nozzles are at an angle of about 45°

.

8. A process according to claim 6 wherein the lower nozzles are directed upwardly and outwardly.

9. A process according to claim 8 wherein the lower nozzles are at an angle of about 45°

.

10. A process according to claim 2 wherein the hydrogen injection nozzles comprise vertical tubes with top outlets, uniformly spaced across the cross-section of the hydrocracking zone.

11. A process according to claim 10 wherein the hydrogen injection nozzles give a flat gas profile across the hydrocracking zone and a velocity of at least about 120 m/sec.

12. A process according to claim 11 wherein the hydrogen injection nozzle top outlets have a diameter of about 6 to 25 mm.

13. A process according to claim 3 wherein the hydrogen-containing gas combined with the slurry feed comprises about 10-35% by volume of the hydrogen-containing gas being fed to the hydrocracking zone.

14. A process according to claim 13 wherein the combined slurry feed and hydrogen-containing gas is fed into the vessel through an injector having a plurality of side openings which direct flow in an outward direction.