Sequential slurry hydroconversion of heavy oils

Patent metadata

Field	Value
Publication number	US-9605217-B2
Application number	US-201414308912-A
Country	US
Kind code	B2
Filing date	Jun 19, 2014
Priority date	Jun 20, 2013
Publication date	Mar 28, 2017
Grant date	Mar 28, 2017

Abstract

Systems and methods are provided for sequential slurry hydroconversion of heavy oil feedstocks. One or more low pressure slurry hydroconversion stages can be used to perform a majority of the conversion of a heavy oil feedstock. The bottoms from the low pressure stages can then be slurry hydroconverted in one or more high pressure stages to further convert the feedstock.

First claim

What is claimed is:

1. A method for processing a heavy oil feedstock, comprising:
providing a heavy oil feedstock having a 10% distillation point of at least about 650° F. (343° C.);
exposing the heavy oil feedstock to a catalyst under first effective slurry hydroconversion conditions to form an effluent comprising at least a first plurality of liquid products and a bottoms product, the first effective slurry hydroconversion conditions comprising a hydrogen partial pressure of about 1500 psig (10.3 MPag) or less;
exposing at least a portion of the bottoms product to the catalyst under second effective slurry hydroconversion conditions comprising hydrogen partial pressure of at least about 2000 psig (13.8 MPag) to form at least a second plurality of liquid products and a second bottoms product; and
recycling at least a portion of the second bottoms product, the recycled portion of the second bottoms product being combined with the heavy oil feedstock prior to exposing the heavy oil feedstock under the first slurry hydroconversion conditions.

2. A method for processing a heavy oil feedstock, comprising:
providing a heavy oil feedstock having a 10% distillation point of at least about 650° F. (343° C.);
exposing the heavy oil feedstock to a catalyst under first effective slurry hydroconversion conditions to form an effluent comprising at least a first plurality of liquid products and a bottoms product, the first effective slurry hydroconversion conditions comprising a hydrogen partial pressure of about 1500 psig (10.3 MPag) or less;
exposing at least a portion of the bottoms product to a second catalyst under second effective slurry hydroconversion conditions comprising hydrogen partial pressure of at least about 2000 psig (13.8 MPag) to form at least a second plurality of liquid products and a second bottoms product; and
recycling at least a portion of the second bottoms product, the recycled portion of the second bottoms product being combined with the heavy oil feedstock prior to exposing the heavy oil feedstock under the first slurry hydroconversion conditions.

3. The method of claim 2 , wherein the bottoms product comprises a portion of the first catalyst corresponding to at least about 50% of the first catalyst in the effluent, wherein exposing the bottoms product to the second catalyst comprises exposing at least a portion the bottoms product to the second catalyst.

4. The method of claim 2 , wherein the second catalyst is the portion of the first catalyst contained in the bottoms product.

5. The method of claim 2 , further comprising separating the bottoms product to form a first catalyst fraction and a catalyst-depleted resid or bottoms fraction, the catalyst-depleted bottoms fraction containing about 25 wt % or less of the catalyst in the bottoms fraction prior to separation, wherein exposing at least a portion of the slurry resid or bottoms fraction to the second catalyst comprises exposing at least a portion of the catalyst-depleted bottoms fraction to the second catalyst.

6. The method of claim 5 , further comprising introducing the second catalyst into the catalyst-depleted bottoms fraction.

7. The method of claim 1 , wherein the 10% distillation point of the heavy oil feedstock is at least about 900° F.

8. The method of claim 1 , wherein the heavy oil feedstock has a Conradson carbon residue of greater than about 5 wt %.

9. The method of claim 1 , wherein the heavy oil feedstock has a Conradson carbon residue of less than about 30 wt %.

10. The method of claim 1 , further comprising:
combining at least a portion of one or more of the first plurality of liquid products with at least a portion of one or more of the second plurality of liquid products;
hydroprocessing the combined liquid products; and
fractionating the combined liquid products.

11. The method of claim 10 , wherein hydroprocessing the combined liquid products comprises hydrotreating the combined liquid products.

12. The method of claim 1 , wherein the first effective slurry hydroconversion conditions are effective for conversion of about 25 wt % to about 60 wt % of the heavy oil feedstock relative to a conversion temperature of at least about 975° F. (524° C.).

13. The method of claim 1 , wherein the first effective slurry hydroconversion conditions and the second slurry hydroconversion conditions are effective for a combined conversion of at least about 90 wt % of the heavy oil feedstock relative to a conversion temperature of at least about 975° F. (524° C.).

14. The method of claim 1 , wherein the second effective slurry hydroconversion conditions comprise a catalyst concentration that is at least twice a catalyst concentration of the first effective slurry hydroconversion conditions.

15. The method of claim 1 , wherein the hydrogen partial pressure of the first effective slurry hydroconversion conditions is about 500 psig (3.4 MPag) or less.

16. The method of claim 1 , wherein a temperature of the second effective slurry hydroconversion conditions is greater than a temperature of the first effective slurry hydroconversion conditions by about 10° C. to about 80° C.

17. The method of claim 16 , wherein a temperature of the second effective slurry hydroconversion conditions is greater than a temperature of the first effective slurry hydroconversion conditions by at least about 20° C.

18. The method of claim 1 , further comprising fractionating the first slurry hydroconversion effluent to form at least one of a naphtha fraction or a distillate fuel fraction, and the bottoms fraction.

19. The method of claim 18 , wherein the first slurry hydroconversion effluent is fractionated in a divided wall fractionator, the method further comprising fractionating the second slurry hydroconversion effluent in the divided wall fractionator.

Assignees

• Sundararaman Ramanathan
• Degnan Jr Thomas Francis
• Billimoria Rustom Merwan
• Smiley Randolph J
• Exxonmobil Res & Eng Co

Inventors

• Sundararaman Ramanathan
• Degnan Jr Thomas Francis
• Billimoria Rustom Merwan
• Smiley Randolph J

Classifications

• C10G49/12

  suspended in the oil, e.g. slurries · CPC title

• C10G47/26

  suspended in the oil, e.g. slurries · CPC title

• C10G45/16

  suspended in the oil, e.g. slurries · CPC title

• C10G65/02 Primary

  plural serial stages only · CPC title

• C10G65/12

  including cracking steps and other hydrotreatment steps · CPC title