Production of lubricant oils from thermally cracked resids

Patent metadata

Field	Value
Publication number	US-2016298048-A1
Application number	US-201615096867-A
Country	US
Kind code	A1
Filing date	Apr 12, 2016
Priority date	Apr 13, 2015
Publication date	Oct 13, 2016
Grant date	—

Abstract

Methods are provided for processing deasphalted gas oils derived from thermally cracked resid fractions to form Group I, Group II, and/or Group III lubricant base oils. The yield of lubricant base oils (optionally also referred to as base stocks) can be increased by thermally cracking a resid fraction at an intermediate level of single pass severity relative to conventional methods. By performing thermal cracking to a partial level of conversion, compounds within a resid fraction that are beneficial for increasing both the viscosity and the viscosity index of a lubricant base oil can be retained, thus allowing for an improved yield of higher viscosity lubricant base oils from a thermally cracked resid fraction.

First claim

What is claimed is:

1 . A method for producing a lubricant base oil product, comprising:
providing a feedstock comprising a 650° F.+ (343° C.) fraction, at least 10 wt % of the 650° F.+ fraction comprising a portion having a boiling point of at least 1050° F. (566° C.); exposing at least a portion of the 650° F.+ (343° C.) fraction to effective thermal cracking conditions to form a thermal cracking effluent, the thermal cracking effluent comprising at least a first thermal cracking effluent fraction having a 10% distillation point of at least 700° F. (371° C.) and a second thermal cracking effluent fraction having a lower boiling range, the effective thermal cracking conditions being selected for single pass conversion of 30 wt % to 80 wt % of the portion having a boiling point of at least 1050° F. (566° C.); and deasphalting at least a portion of the first thermal cracking effluent fraction to form at least a deasphalted thermal cracking effluent and a deasphalting residue; wherein at least a first portion of the deasphalted thermal cracking effluent has a viscosity index of at least 50 and a viscosity at 100° C. of at least 7.0 cSt.

2 . The method of claim 1 , wherein the at least a first portion of the deasphalted thermal cracking effluent having a viscosity index of at least 50 and a viscosity of at least 7.0 cSt at 100° C. comprises a raffinate from performing a solvent extraction on at least a second portion of the deasphalted thermal cracking effluent, a raffinate yield from performing the solvent extraction on the at least a second portion of the deasphalted thermal cracking effluent optionally being at least 30 wt %.

3 . The method of claim 1 , the method further comprising:
exposing the at least a first portion of the deasphalted thermal cracking effluent to a dewaxing catalyst under effective catalytic dewaxing conditions and a hydrofinishing catalyst under effective hydrofinishing conditions, to form a dewaxed, hydrofinished effluent, wherein the dewaxed, hydrofinished effluent has a viscosity index that is at least 5 greater than the viscosity index of the at least a portion of the deasphalted thermal cracking effluent.

4 . The method of claim 1 , wherein at least 50 wt % of the 650° F.+ (343° C.) fraction has a boiling point of at least 1050° F. (566° C.), wherein the first thermal cracking effluent fraction has a T95 boiling point of at least 1050° F. (566° C.), or a combination thereof.

5 . The method of claim 1 , wherein the at least a first portion of the deasphalted thermal cracking effluent has a viscosity index of at least 80, or wherein the at least a first portion of the deasphalted thermal cracking effluent has a viscosity at 100° C. of at least 8.0 cSt, or a combination thereof.

6 . The method of claim 1 , further comprising hydrotreating the at least a first portion of the deasphalted thermal cracking effluent under effective hydrotreating conditions to form a hydrotreated deasphalted thermal cracking effluent having a sulfur content of 300 wppm or less.

7 . The method of claim 1 , further comprising hydrocracking at least a second portion of the deasphalted thermal cracking effluent under effective hydrocracking conditions to form a hydrocracked deasphalted thermal cracking effluent having a sulfur content of 300 wppm or less, the at least a first portion of the deasphalted thermal cracking effluent comprising at least a portion of the hydrocracked deasphalted thermal cracking effluent.

8 . The method of claim 1 , wherein the effective thermal cracking conditions comprise hydroconversion conditions, the hydroconversion conditions including a temperature of at least 400° C. and a hydrogen partial pressure of 1500 psig (10.3 MPa) or less.

9 . The method of claim 1 , wherein the effective thermal cracking conditions comprise fluidized coking conditions, including a temperature of at least 500° C. and a pressure of 50 psig (345 kPa) or less.

10 . A method for producing a lubricant base oil product, comprising:
providing a feedstock comprising a 650° F.+ (343° C.) fraction, at least 10 wt % of the 650° F.+ fraction comprising a portion having a boiling point of at least 1050° F. (566° C.); deasphalting a first portion of the feedstock to form at least a first deasphalted oil and a first deasphalting residual product; exposing at least a first portion of first deasphalting residual product to effective thermal cracking conditions to form a thermal cracking effluent, the thermal cracking effluent comprising at least a first thermal cracking effluent fraction having a 10% distillation point of at least 650° F. (343° C.) and a second thermal cracking effluent fraction having a lower boiling range, the effective thermal cracking conditions being selected for single pass conversion of 50 wt % to 80 wt % of the portion having a boiling point of at least 1050° F. (566° C.); deasphalting at least a portion of the first thermal cracking effluent fraction to form at least a deasphalted thermal cracking effluent, the deasphalted thermal cracking effluent having a first viscosity index; exposing at least a portion of the deasphalted thermal cracking effluent to a hydrocracking catalyst under effective hydrocracking conditions to form a hydrocracked effluent; and exposing at least a portion of the hydrocracked effluent to a dewaxing catalyst under effective catalytic dewaxing conditions, and a hydrofinishing catalyst under effective hydrofinishing conditions, to form one or more lubricant products, the one or more lubricant products having a viscosity of at least 6 cSt at 100° C. and a viscosity index of at least 90, a yield of the one or more lubricant products being at least 15 wt % of the 650° F.+ (343° C.) fraction of the feedstock.

11 . The method of claim 10 , further comprising combining a second portion of the feedstock and a second portion of the first deasphalting residual product to form an asphalt feed.

12 . The method of claim 10 , further comprising at least one of:
a) forming a Group I base oil from the first deasphalted oil, the forming a Group I base oil comprising:
solvent extracting at least a portion of the first deasphalted oil to form an extraction raffmate; and
solvent dewaxing at least a portion of the extraction raffmate to form a Group I base oil; or
b) forming a base oil from the first deasphalted oil, the forming a base oil comprising:
hydrocracking at least a portion of the first deasphalted oil in the presence of a hydrocracking catalyst to form a hydrocracked effluent;
dewaxing at least a portion of the hydrocracked effluent in the presence of a dewaxing catalyst and hydrofinishing at least a portion of the hydrocracked effluent in the presence of a hydrofinishing catalyst to form a base oil.

13 . The method of claim 10 , wherein deasphalting a feedstock comprising a 650° F.+ (343° C.) fraction comprises deasphalting a feedstock comprising the 650° F.+ fraction and a recycled fraction,
wherein exposing at least a portion of the deasphalting residual product to effective thermal cracking conditions further comprises forming a third thermal cracking effluent having a 10% distillation point of at least 800° F. (427° C.),
wherein the method further comprises recycling at least a portion of the third thermal cracking effluent as the recycled fraction, and
wherein exposing at least a portion of the deasphalted thermal cracking effluent to a hydrocracking catalyst comprises exposing at least a portion of the deasphalted thermal cracking effluent and at least a portion of the first deasphalted oil.

14 . The method of claim 13 , wherein the effective thermal crac

Assignees

• Exxonmobil Res & Eng Co

Inventors

• Brown Stephen H
• Raich Brenda A
• Gooding Beatrice M
• Davis Stephen M
• Barrai Federico
• Ames Warren B
• Aldous Keith K

Classifications

• C10G53/04

  including at least one extraction step · CPC title

• C10G2300/107

  Atmospheric residues having a boiling point of at least about 538 °C · CPC title

• C10G55/04 Primary

  including at least one thermal cracking step · CPC title

• C10G2400/10

  Lubricating oil · CPC title

• C10G67/00

  Treatment of hydrocarbon oils by at least one hydrotreatment process and at least one process for refining in the absence of hydrogen only · CPC title