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US 10,865,352 B2Granted
Removal of polynuclear aromatics from severely hydrotreated base stocks
AssigneeExxonMobil Research and Engineering Company
InventorsWilliam R. Gunther, Kendall S. Fruchey, Vinit Choudhary, Adrienne R. Diebold, Jason M. McMullan
Life of this patent
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Abstract
Adsorbents for aromatic adsorption are used to improve one or more properties of base stocks derived from deasphalted oil fractions. The adsorbents can allow for removal of polynuclear aromatics from an intermediate effluent or final effluent during base stock production. Removal of polynuclear aromatics can be beneficial for improving the color of heavy neutral base stocks and/or reducing the turbidity of bright stocks.
Claims18
A method for making lubricant base stock, comprising:
- performing solvent deasphalting, under effective solvent deasphalting conditions on a feedstock having a T5 boiling point of 370° C. or more and a T50 of 510° C. or more, the effective solvent deasphalting conditions producing a yield of deasphalted oil of 40 wt % or more of the feedstock;
- hydroprocessing at least a portion of the deasphalted oil under first effective hydroprocessing conditions to form a hydroprocessed effluent, the at least a portion of the deasphalted oil having an aromatics content of 60 wt % or more, the hydroprocessed effluent comprising a sulfur content of 300 wppm or less, a nitrogen content of 100 wppm or less, or a combination thereof;
- separating, from the hydroprocessed effluent, at least a fuels boiling range fraction, a first fraction comprising polynuclear aromatics and having a T5 distillation point of at least 370° C., and a second fraction having T5 distillation point of at least 370° C., the second fraction having a higher kinematic viscosity at 100° C. than the first fraction;
- hydroprocessing at least a portion of the first fraction under second effective hydroprocessing conditions, the second effective hydroprocessing conditions comprising catalytic dewaxing conditions, to form a twice-hydroprocessed effluent comprising a 370° C.+ portion having a first kinematic viscosity at 100° C.;
- and
- i) exposing the at least a portion of the first fraction, prior to the hydroprocessing under second effective hydroprocessing conditions, to an adsorbent under aromatic adsorbent conditions to form an adsorbent effluent having a reduced content of polynuclear aromatics relative to the at least a portion of the first fraction prior to the exposing;
- ii) exposing at least a portion of the twice-hydroprocessed effluent, during or after the hydroprocessing under second effective hydroprocessing conditions, to an adsorbent under aromatic adsorbent conditions to form an adsorbent effluent having a reduced content of polynuclear aromatics relative to the at least a portion of the twice-hydroprocessed effluent prior to the exposing;
- or iii) a combination of i) and ii);
- and further comprising separating a third fraction and a fourth fraction from the at least a portion of the twice-hydroprocessed effluent, the fourth fraction having a higher kinematic viscosity at 100° C. than the third fraction and adding a diluent stream to the twice-hydroprocessed effluent or the at least a portion of the twice-hydroprocessed effluent prior to separating the third fraction and the fourth fraction.
6 more elements
A method for making lubricant base stock, comprising:
- performing solvent deasphalting, under effective solvent deasphalting conditions on a feedstock having a T5 boiling point of 370° C. or more and a T50 of 510° C. or more, the effective solvent deasphalting conditions producing a yield of deasphalted oil of 40 wt % or more of the feedstock;
- hydroprocessing at least a portion of the deasphalted oil under first effective hydroprocessing conditions to form a hydroprocessed effluent, the at least a portion of the deasphalted oil having an aromatics content of 60 wt % or more, the hydroprocessed effluent comprising a sulfur content of 300 wppm or less, a nitrogen content of 100 wppm or less, or a combination thereof;
- separating, from the hydroprocessed effluent, at least a fuels boiling range fraction, a first fraction comprising polynuclear aromatics and having a T5 distillation point of at least 370° C., and a second fraction having a T5 distillation point of at least 370° C., the second fraction having a higher kinematic viscosity at 100° C. than the first fraction;
- hydroprocessing at least a portion of the first fraction under second effective hydroprocessing conditions, the second effective hydroprocessing conditions comprising catalytic dewaxing conditions, to form a twice-hydroprocessed effluent comprising a 370° C.+ portion having a first kinematic viscosity at 100° C.;
- and
- i) exposing the at least a portion of the first fraction, prior to the hydroprocessing under second effective hydroprocessing conditions, to an adsorbent under aromatic adsorbent conditions to form an adsorbent effluent having a reduced content of polynuclear aromatics relative to the at least a portion of the first fraction prior to the exposing, ii) exposing at least a portion of the twice-hydroprocessed effluent, during or after the hydroprocessing under second effective hydroprocessing conditions, to an adsorbent under aromatic adsorbent conditions to form an adsorbent effluent having a reduced content of polynuclear aromatics relative to the at least a portion of the twice-hydroprocessed effluent prior to the exposing;
- or iii) a combination of i) and ii);
- and further comprising hydroprocessing at least a portion of the second fraction under third effective hydroprocessing conditions, the third effective hydroprocessing conditions comprising catalytic dewaxing conditions, to form a second twice-hydroprocessed effluent comprising a 370° C.+ portion having a second kinematic viscosity at 100° C.;
- separating from at least a portion of the second twice-hydroprocessed effluent a fifth fraction and a sixth fraction, the sixth fraction having a higher kinematic viscosity at 100° C. than the fifth fraction;
- and
- exposing;
- at least a portion of the fifth fraction to an adsorbent under aromatic adsorbent conditions to form an effluent having a reduced content of polynuclear aromatics relative to the at least a portion of the fifth fraction.
9 more elements
A method for making lubricant base stock, comprising:
- performing solvent deasphalting, under effective solvent deasphalting conditions on a feedstock having a T5 boiling point of 370° C. or more and a T50 of 510° C. or more, the effective solvent deasphalting conditions producing a yield of deasphalted oil of 40 wt % or more of the feedstock;
- hydroprocessing at least a portion of the deasphalted oil under first effective hydroprocessing conditions to form a hydroprocessed effluent, the at least a portion of the deasphalted oil having an aromatics content of 60 wt % or more, the hydroprocessed effluent comprising a sulfur content of 300 wppm or less, a nitrogen content of 100 wppm or less, or a combination thereof;
- separating, from the hydroprocessed effluent, at least a fuels boiling range fraction, a first fraction comprising polynuclear aromatics and having a T5 distillation point of at least 370° C., and a second fraction having a T5 distillation point of at least 370° C., the second fraction having a higher kinematic viscosity at 100° C. than the first fraction;
- hydroprocessing at least a portion of the first fraction under second effective hydroprocessing conditions, the second effective hydroprocessing conditions comprising catalytic dewaxing conditions, to form a twice-hydroprocessed effluent comprising a 370° C.+ portion having a first kinematic viscosity at 100° C.;
- and
- i) exposing the at least a portion of the first fraction, prior to the hydroprocessing under second effective hydroprocessing conditions to an adsorbent under aromatic adsorbent conditions to form an adsorbent effluent having a reduced content of polynuclear aromatics relative to the at least a portion of the first fraction prior to the exposing;
- ii) exposing at least a portion of the twice-hydroprocessed effluent, during or after the hydroprocessing under second effective hydroprocessing conditions, to an adsorbent under aromatic adsorbent conditions to form an adsorbent effluent having a reduced content of polynuclear aromatics relative to the at least a portion of the twice-hydroprocessed effluent prior to the exposing;
- or iii) a combination of i) and ii);
- and wherein separating the hydroprocessed effluent further comprises forming an additional fraction having a T5 distillation point of at least 370° C., the method further comprising:
- hydroprocessing at least a portion of the additional fraction under third effective hydroprocessing conditions, the third effective hydroprocessing conditions comprising catalytic dewaxing conditions, to form a third catalytically dewaxed effluent comprising a 370° C.+ portion having a kinematic viscosity at 100° C. of 3.5 cSt or more.
7 more elements
A method for making lubricant base stock, comprising:
- performing solvent deasphalting, under effective solvent deasphalting conditions on a feedstock having a T5 boiling point of 370° C. or more and a T50 of 510° C. or more, the effective solvent deasphalting conditions producing a yield of deasphalted oil of 40 wt % or more of the feedstock;
- hydroprocessing at least a portion of the deasphalted oil under first effective hydroprocessing conditions to form a hydroprocessed effluent, the at least a portion of the deasphalted oil having an aromatics content of 60 wt % or more, the hydroprocessed effluent comprising a sulfur content of 300 wppm or less, a nitrogen content of 100 wppm or less, or a combination thereof;
- separating, from the hydroprocessed effluent, at least a fuels boiling range fraction, a first fraction comprising 6+ ring aromatics and having a T5-distillation point of at least 370° C., and a second fraction having a T5-distillation point of at least 370° C., the second fraction having a higher kinematic viscosity at 100° C. than the first fraction;
- hydroprocessing at least a portion of the second fraction under second effective hydroprocessing conditions, the second effective hydroprocessing conditions comprising catalytic dewaxing conditions, to form a twice-hydroprocessed effluent comprising a 370° C.+ portion having a kinematic viscosity at 100° C. of 16 cSt or greater;
- and
- i) exposing the at least a portion of the second fraction, prior to the hydroprocessing under second effective hydroprocessing conditions, to an adsorbent under aromatic adsorbent conditions to form an adsorbent effluent having a reduced content of polynuclear aromatics relative to the at least a portion of the second fraction prior to the exposing;
- ii) exposing at least a portion of the twice-hydroprocessed effluent, during or after the hydroprocessing under second effective hydroprocessing conditions, to an adsorbent under aromatic adsorbent conditions to form an adsorbent effluent having a reduced content of polynuclear aromatics relative to the at least a portion of the twice-hydroprocessed effluent prior to the exposing;
- or iii) a combination of i) and ii);
- and further comprising adding a diluent stream to the at least a portion of the twice-hydroprocessed effluent prior to the exposing at least a portion of the twice-hydroprocessed effluent to an adsorbent, the diluent stream comprising at least a portion of the fuels boiling range fraction, at least a portion of the first fraction, or a combination thereof.
6 more elements
Dependencies are inferred from the claim text.