Catalyst configuration for increased hydrocracking activity

Patent metadata

Field	Value
Publication number	US-9938475-B2
Application number	US-201514877018-A
Country	US
Kind code	B2
Filing date	Oct 7, 2015
Priority date	Oct 28, 2014
Publication date	Apr 10, 2018
Grant date	Apr 10, 2018

Abstract

Systems and methods are provided for producing an improved product slate during hydrocracking of a feedstock for production of naphtha and distillate fuels. The methods can include use of stacked beds and/or sequential reactors so that a feedstock is exposed to a suitable catalyst under aromatic saturation conditions prior to exposing the feedstock to the hydrocracking catalyst. The catalyst for performing the aromatic saturation process can be a catalyst including a Group VIII noble metal, such as Pt, Pd, or a combination thereof, while the hydrocracking catalyst can include Group VIB and Group VIII non-noble metals.

First claim

What is claimed is:

1. A method for processing a feedstock to form a distillate product, comprising:
first exposing a feedstock having a T50 boiling point of at least about 430° F. (221° C.), a first aromatics content of at least about 5 wt %, and a sulfur content of about 500 wppm or less to an aromatic saturation catalyst comprising a Group VIII noble metal under effective aromatic saturation conditions to produce an aromatic saturation effluent, the aromatic saturation effluent having a second aromatics content of less than about 10 wt %, the second aromatics content being less than the first aromatics content; and then
exposing at least a portion of the aromatic saturation effluent to a hydrocracking catalyst under effective hydrocracking conditions to produce a hydrocracked effluent, the effective hydrocracking conditions being effective for converting at least about 5 wt % of the at least a portion of the aromatic saturation effluent relative to a conversion temperature of 430° F. (221° C.), the hydrocracking catalyst comprising at least one Group VIII non-noble metal, at least one Group VIB metal, or a combination thereof,
wherein the hydrocracked effluent comprises at least a naphtha fuel product fraction and a distillate fuel product fraction; wherein the hydrocracked effluent includes a C 4 product fraction having an iso-C 4 to n-C 4 ratio of at least about 5.

2. The method of claim 1 , wherein a ratio of the second aromatics content to the first aromatics content is about 0.5 or less.

3. The method of claim 1 , wherein the second aromatics content is less than about 5 wt %.

4. The method of claim 1 , wherein the first aromatics content is at least about 10 wt %.

5. The method of claim 1 , wherein the feedstock has a T5 boiling point of at least about 430° F. (221° C.).

6. The method of claim 1 , wherein the feedstock has a T95 boiling point of about 800° F. (427° C.) or less.

7. The method of claim 1 , further comprising fractionating at least a portion of the hydrocracked effluent to form at least a naphtha product fraction and a bottoms fraction.

8. The method of claim 7 , wherein the feedstock comprises at least a portion of the bottoms fraction.

9. The method of any of claim 7 , wherein the bottoms fraction comprises the distillate fuel product fraction.

10. The method of any of claim 7 , wherein fractionating at least a portion of the hydrocracked effluent further comprises separating a C 4 product stream from the hydrocracked effluent, the separated C 4 product stream having an iso-C 4 to n-C 4 ratio of at least about 5.

11. The method of claim 1 , further comprising exposing a feed having a sulfur content of greater than about 500 wppm to a hydroprocessing catalyst under effective hydroprocessing conditions to form a hydroprocessed effluent; and
separating the hydroprocessed effluent to form at least a hydroprocessed fraction having a T95 boiling point of about 1050° F. (566° C.) or less,
wherein the feedstock having a T50 boiling point of at least about 430° F. (221° C.) comprises at least a portion of the hydroprocessed fraction having a T95 boiling point of about 1050° F. (566° C.) or less.

12. The method of claim 11 , wherein separating the hydroprocessed effluent comprises fractionating the hydroprocessed effluent, the fractionating optionally further forming a second naphtha fuel product fraction.

13. The method of claim 11 , wherein the hydroprocessed effluent and the hydrocracked effluent are fractionated in a common fractionation process.

14. The method of claim 11 , wherein exposing the feed having a sulfur content of at least about 500 wppm to a hydroprocessing catalyst under effective hydroprocessing conditions comprises:
exposing the feed having a sulfur content of greater than about 500 wppm to a hydrotreating catalyst under effective hydrotreating conditions, exposing the feed having a sulfur content of greater than about 500 wppm to a hydrocracking catalyst under effective hydrocracking conditions, or a combination thereof.

15. The method of claim 11 , wherein the feed having a sulfur content of greater than about 500 wppm has a T5 boiling point of at least about 430° F. (221° C.) and a T95 boiling point of about 1050° F. (566° C.) or less.

16. The method of claim 11 , wherein at least about 50 wt % of the feedstock having a T50 boiling point of at least about 430° F. (221° C.) comprises the at least a portion of the hydroprocessed fraction having a T95 boiling point of about 1050° F. (566° C.) or less.

17. The method of claim 1 , wherein aromatic saturation catalyst comprises about 0.1 wt % to about 1.8 wt % of Pt, Pd, or a combination thereof.

18. The method of claim 1 , further comprising dewaxing the hydrocracked effluent prior to fractionating the at least a portion of the hydrocracked effluent.

19. A method for processing a feedstock to form a distillate product, comprising:
first exposing a feedstock having a T50 boiling point of at least about 430° F. (221° C.), a first aromatics content, and a sulfur content of about 500 wppm or less to an aromatic saturation catalyst comprising a Group VIII noble metal under effective aromatic saturation conditions to produce an aromatic saturation effluent, the aromatic saturation effluent having a second aromatics content, a ratio of the second aromatics content to the first aromatics content being about 0.6 or less; and then
exposing at least a portion of the aromatic saturation effluent to a hydrocracking catalyst under effective hydrocracking conditions to produce a hydrocracked effluent, the effective hydrocracking conditions being effective for converting at least about 5 wt % of the at least a portion of the aromatic saturation effluent relative to a conversion temperature of 430° F. (221° C.), the hydrocracking catalyst comprising at least one Group VIII non-noble metal, at least one Group VIB metal, or a combination thereof;
wherein the hydrocracked effluent comprises at least a naphtha fuel product fraction and a distillate fuel product fraction; wherein the hydrocracked effluent includes a C 4 product fraction having an iso-C 4 to n-C 4 ratio of at least about 5.

20. The method of claim 19 , wherein the ratio of the second aromatics content to the first aromatics content is about 0.3 or less.

Assignees

• Xu Xiaochun
• Miller Amanda K
• Exxonmobil Res & Eng Co

Inventors

• Xu Xiaochun
• Miller Amanda K

Classifications

• C10G45/46

  characterised by the catalyst used · CPC title

• C10G65/12 Primary

  including cracking steps and other hydrotreatment steps · CPC title

• C10G47/02

  characterised by the catalyst used · CPC title

• C10G2300/1096

  Aromatics or polyaromatics · CPC title

• C10G2300/202

  Heteroatoms content, i.e. S, N, O, P · CPC title