Sequential deasphalting for base stock production

Patent metadata

Field	Value
Publication number	US-10550341-B2
Application number	US-201615390896-A
Country	US
Kind code	B2
Filing date	Dec 27, 2016
Priority date	Dec 28, 2015
Publication date	Feb 4, 2020
Grant date	Feb 4, 2020

Abstract

Methods are provided for producing lubricant base stocks from deasphalted oils formed by sequential deasphalting. The deasphalted oil can be exposed a first deasphalting process using a first solvent that can provide a lower severity of deasphalting and a second deasphalting process using a second solvent that can provide a higher severity of deasphalting. This can result in formation of at least a deasphalted oil and a resin fraction. The resin fraction can represent a fraction that traditionally would have been included as part of a deasphalter rock fraction.

First claim

The invention claimed is:

1. A method for making lubricant base stock, comprising:
performing solvent deasphalting using a C 5+ solvent under first effective solvent deasphalting conditions on a feedstock having a T5 boiling point of at least about 400° C. to produce a first deasphalted oil and a first deasphalter residue, the first effective solvent deasphalting conditions producing a yield of first deasphalted oil of at least 70 wt % of the feedstock;
performing solvent deasphalting on at least a portion of the first deasphalted oil under second effective solvent deasphalting conditions using a C 3 solvent, a C 4 solvent, or a combination thereof to form a second deasphalted oil and a second deasphalter resin;
hydroprocessing at least a portion of the second deasphalted oil under first effective hydroprocessing conditions to form a hydroprocessed effluent, the at least a portion of the second deasphalted oil having an aromatics content of at least about 50 wt %, the hydroprocessed effluent having a sulfur content of 300 wppm or less, and a nitrogen content of 100 wppm or less;
separating the hydroprocessed effluent to form at least a fraction comprising a fuels boiling range fraction and a bottoms fraction;
hydroprocessing at least a portion of the bottoms fraction under second effective hydroprocessing conditions, the second effective hydroprocessing conditions comprising catalytic dewaxing conditions, to form a catalytically dewaxed effluent; and
hydrotreating at least a portion of the second deasphalter resin under hydrotreating conditions to form a hydrotreated resin effluent having a sulfur content of 500 wppm to 10,000 wppm.

2. The method of claim 1 , wherein the catalytically dewaxed effluent comprises a 950° F.+ (510° C.+) portion having a viscosity index of at least 80, a pour point of −6° C. or less, and a cloud point of −2° C. or less; or wherein the 950° F.+ (510° C.+) portion has a difference between a cloud point temperature and a pour point temperature of 25° C. or less; or a combination thereof.

3. The method of claim 1 , wherein hydroprocessing at least a portion of the second deasphalted oil comprises hydrotreating the at least a portion of the second deasphalted oil, hydrocracking the at least a portion of the second deasphalted oil, or a combination thereof.

4. The method of claim 1 , further comprising using the second deasphalter resin as a blend component to produce a fuel oil.

5. The method of claim 1 , further comprising performing a boiling point separation on at least a portion of the hydrotreated resin effluent to form a 566° C.-hydrotreated resin fraction and a bottoms resin fraction, wherein hydroprocessing at least a portion of the second deasphalted oil further comprises hydroprocessing at least a portion of the 566° C.-hydrotreated resin fraction.

6. The method of claim 1 , further comprising performing solvent deasphalting on at least a portion of the hydrotreated resin effluent under third solvent deasphalting conditions using a C 3 solvent, a C 4 solvent, or a combination thereof to form a third deasphalted oil and third deasphalter residue, wherein hydroprocessing at least a portion of the second deasphalted oil further comprises hydroprocessing at least a portion of the third deasphalted oil.

7. The method of claim 1 , wherein the C 5+ solvent comprises a mixture of two or more C 5 isomers.

8. The method of claim 1 , wherein a yield of the first deasphalted oil is at least 75 wt %.

9. The method of claim 1 , wherein the second effective solvent deasphalting conditions comprise using a C 3 solvent.

10. The method of claim 1 , wherein a yield of the second deasphalted oil is at least 40 wt % of the at least a portion of the first deasphalted oil.

11. The method of claim 1 , wherein the second deasphalted oil has an aromatics content of at least 55 wt % based on a weight of the second deasphalted oil.

12. The method of claim 2 , wherein the 950° F.+ (510° C.+) portion has a pour point of −10° C. or less; or wherein the 950° F.+ (510° C.+) portion has a cloud point of −5° C. or less; or a combination thereof.

13. The method of claim 2 , wherein the 950° F.+ (510° C.+) portion has a viscosity index of at least 90.

14. The method of claim 1 , further comprising using the first deasphalter residue as a blend component to produce at least one of asphalt and fuel oil.

15. The method of claim 1 , further comprising at least one of
a) solvent extracting at least a portion of the catalytically dewaxed effluent to form a solvent processed effluent,
b) solvent dewaxing at least a portion of the catalytically dewaxed effluent to form a solvent processed effluent, wherein the catalytically dewaxed effluent is underdewaxed,
wherein the solvent processed effluent comprises a 950° F.+ (510° C.+) portion having a viscosity index of at least 80, a pour point of −6° C. or less, and a cloud point of −2° C. or less.

16. The method of claim 15 , wherein at least a portion of the catalytically dewaxed effluent is solvent extracted, the solvent processed effluent comprising a 950° F.+ (510° C.+) portion having an aromatics content of less than 10 wt %.

17. The method of claim 16 , wherein the solvent extracting comprises solvent extracting with n-methylpyrrolidone, furfural, or a combination thereof.

18. The method of claim 17 , wherein the catalytically dewaxed effluent comprises a 950° F.+ (510° C.+) portion having a viscosity index of at least 80, a pour point of −6° C. or less, and a cloud point of −2° C. or less; or wherein the 950° F. + (510° C.+) portion has a difference between a cloud point temperature and a pour point temperature of 25° C. or less; or a combination thereof.

Assignees

• Exxonmobil Res & Eng Co

Inventors

• Harandi Mohsen N
• Levin Doron
• Gupta Himanshu
• Lattner James R
• Wood Glenn C
• Aldous Keith K
• Hilbert Timothy L
• Carroll Michael B
• Dandekar Ajit B
• Yohe Sara L
• Brown Stephen H
• Owens Tracie L
• Ross April D
• Senzer Eric B
• Pyl Steven

Classifications

• C10G55/02

  plural serial stages only · CPC title

• C10G67/0463

  The hydrotreatment being a hydrorefining · CPC title

• C10N2030/02

  Pour-point; Viscosity index · CPC title

• C10N2020/02

  Viscosity; Viscosity index · CPC title

• C10N2020/011

  Cloud point · CPC title