U.S. patent application number 15/631540 was filed with the patent office on 2018-07-05 for block processing with bulk catalysts for base stock production from deasphalted oil.
The applicant listed for this patent is ExxonMobil Research and Engineering Company. Invention is credited to Michael B. Carroll, Kendall S. Fruchey, Sara K. Green, Timothy L. Hilbert, Doron Levin.
Application Number | 20180187102 15/631540 |
Document ID | / |
Family ID | 59270182 |
Filed Date | 2018-07-05 |
United States Patent
Application |
20180187102 |
Kind Code |
A1 |
Fruchey; Kendall S. ; et
al. |
July 5, 2018 |
BLOCK PROCESSING WITH BULK CATALYSTS FOR BASE STOCK PRODUCTION FROM
DEASPHALTED OIL
Abstract
Systems and methods are provided for block operation during
lubricant and/or fuels production from deasphalted oil. During
"block" operation, a deasphalted oil and/or the hydroprocessed
effluent from an initial processing stage can be split into a
plurality of fractions. The fractions can correspond, for example,
to feed fractions suitable for forming a light neutral fraction, a
heavy neutral fraction, and a bright stock fraction, or the
plurality of fractions can correspond to any other convenient split
into separate fractions. The plurality of separate fractions can
then be processed separately in the process train (or in the sweet
portion of the process train) for forming fuels and/or lubricant
base stocks. The initial stage can optionally include a bulk
hydrotreating catalyst to assist with increasing the space velocity
in the initial stage.
Inventors: |
Fruchey; Kendall S.;
(Easton, PA) ; Carroll; Michael B.; (Center
Valley, PA) ; Hilbert; Timothy L.; (Middleburg,
VA) ; Green; Sara K.; (Flemington, NJ) ;
Levin; Doron; (Highland Park, NJ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ExxonMobil Research and Engineering Company |
Annandale |
NJ |
US |
|
|
Family ID: |
59270182 |
Appl. No.: |
15/631540 |
Filed: |
June 23, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62439943 |
Dec 29, 2016 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C10G 65/00 20130101;
C10M 2203/1006 20130101; C10G 2400/08 20130101; C10M 101/02
20130101; C10M 2207/10 20130101; C10G 1/086 20130101; B01D 3/16
20130101; C10N 2020/017 20200501; C10M 175/0033 20130101; B01D 3/10
20130101; C10N 2030/20 20130101; C10M 171/02 20130101; C10G 2300/10
20130101; C10N 2020/02 20130101; C10M 2201/06 20130101; C10N
2040/25 20130101; C10N 2070/00 20130101; C10G 65/12 20130101; C10G
2300/1062 20130101; C10M 2201/062 20130101; C10M 2203/1065
20130101; C10G 21/14 20130101; C10G 45/38 20130101; C10G 67/0454
20130101; C10G 2400/10 20130101; C10N 2020/011 20200501; B01L 3/10
20130101; B01D 3/14 20130101; C08L 95/00 20130101; C10N 2030/02
20130101; B01J 23/74 20130101; C10C 3/06 20130101; C10C 3/08
20130101; C10G 2300/1077 20130101; C10G 67/00 20130101 |
International
Class: |
C10G 65/12 20060101
C10G065/12; C10G 67/04 20060101 C10G067/04; C10M 101/02 20060101
C10M101/02; C10M 171/02 20060101 C10M171/02; C10M 175/00 20060101
C10M175/00 |
Claims
1. A method for making lubricant base stock, comprising: performing
solvent deasphalting, optionally using a C.sub.4+ solvent, under
effective solvent deasphalting conditions on a feedstock having a
T5 boiling point of at least about 370.degree. C., the effective
solvent deasphalting conditions producing a yield of deasphalted
oil of at least about 50 wt % of the feedstock; hydroprocessing at
least a portion of the deasphalted oil under first effective
hydroprocessing conditions to form a hydroprocessed effluent, the
hydroprocessing comprising exposing the at least a portion of the
deasphalted oil to a mixed metal catalyst under the hydroprocessing
conditions, the at least a portion of the deasphalted oil having an
aromatics content of at least about 50 wt %, 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 the hydroprocessed effluent to form at least a fuels
boiling range fraction, a first fraction having a T.sub.5
distillation point of at least 370.degree. C., and a second
fraction having a T.sub.5 distillation point of at least
370.degree. C., the second fraction having a higher kinematic
viscosity at 100.degree. 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 first catalytically dewaxed effluent
comprising a 370.degree. C.+ portion having a first kinematic
viscosity at 100.degree. C.; and 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
catalytically dewaxed effluent comprising a 370.degree. C.+ portion
having a second kinematic viscosity at 100.degree. C. that is
greater than the first kinematic viscosity at 100.degree. C.,
wherein the second effective hydroprocessing conditions are
different from the third effective hydroprocessing conditions, and
wherein the mixed metal catalyst comprises a sulfided mixed metal
catalyst formed by sulfiding a mixed metal catalyst precursor
composition, the mixed metal catalyst precursor composition being
produced by a) heating a composition comprising at least one metal
from Group 6 of the Periodic Table of the Elements, at least one
metal from Groups 8-10 of the Periodic Table of the Elements, and a
reaction product formed from (i) a first organic compound
containing at least one amine group, and (ii) a second organic
compound separate from said first organic compound and containing
at least one carboxylic acid group to a temperature from about
195.degree. C. to about 260.degree. C. for a time sufficient for
the first and second organic compounds to form a reaction product
in situ that contains an amide moiety, unsaturated carbon atoms not
present in the first or second organic compounds, oxygen atoms not
present in the first or second organic compounds, or a combination
thereof; b) heating a composition comprising one metal from Group 6
of the Periodic Table of the Elements, at least one metal from
Groups 8-10 of the Periodic Table of the Elements, and a reaction
product formed from (iii) a first organic compound containing at
least one amine group and at least 10 carbon atoms or (iv) a second
organic compound containing at least one carboxylic acid group and
at least 10 carbon atoms, but not both (iii) and (iv), wherein the
reaction product contains additional unsaturated carbon atoms,
relative to (iii) the first organic compound or (iv) the second
organic compound, wherein the metals of the catalyst precursor
composition are arranged in a crystal lattice, and wherein the
reaction product is not located within the crystal lattice, to a
temperature from about 195.degree. C. to about 260.degree. C. for a
time sufficient for the first or second organic compounds to form a
reaction product in situ that contains unsaturated carbon atoms not
present in the first or second organic compounds, oxygen atoms not
present in the first or second organic compounds, or a combination
thereof; or c) heating a composition comprising at least one metal
from Group 6 of the Periodic Table of the Elements, at least one
metal from Groups 8-10 of the Periodic Table of the Elements, and a
pre-formed amide formed from (v) a first organic compound
containing at least one amine group, and (vi) a second organic
compound separate from said first organic compound and containing
at least one carboxylic acid group, to form at least one of
additional in situ unsaturated carbon atoms or in situ added oxygen
atoms not present in the first organic compound, the second organic
compound, or both, but not for so long that the pre-formed amide
substantially decomposes, thereby forming a catalyst precursor
containing at least one of in situ formed unsaturated carbon atoms
or in situ added oxygen atoms.
2. The method of claim 1, wherein the catalyst precursor
composition is treated first with said first organic compound and
second with said second organic compound, or wherein the catalyst
precursor composition is treated first with said second organic
compound and second with said first organic compound, or wherein
the catalyst precursor composition is treated simultaneously with
said first organic compound and with said second organic
compound.
3. The method of claim 1, wherein said at least one metal from
Group 6 is Mo, W, or a combination thereof, and wherein said at
least one metal from Groups 8-10 is Co, Ni, or a combination
thereof.
4. The process of claim 1, wherein the mixed metal catalyst
precursor composition is a bulk metal hydroprocessing catalyst
precursor composition consisting essentially of the reaction
product, an oxide form of the at least one metal from Group 6, an
oxide form of the at least one metal from Groups 8-10, and
optionally about 20 wt % or less of a binder.
5. The method of claim 1, wherein the second effective
hydroprocessing conditions further comprise hydrocracking
conditions and the third effective hydroprocessing conditions
further comprise hydrocracking conditions, the second effective
hydroprocessing conditions and third effective hydroprocessing
conditions being different based on a difference in at least one of
a hydrocracking pressure, a hydrocracking temperature, a dewaxing
pressure, and a dewaxing temperature.
6. The method of claim 1, further comprising at least one of: a)
solvent extracting at least a portion of the second catalytically
dewaxed effluent to form a solvent processed effluent, or b)
solvent dewaxing at least a portion of the second catalytically
dewaxed effluent to form a solvent processed effluent, wherein the
solvent processed effluent comprises a T5 distillation point of at
least 482.degree. C., a VI of at least 80, a pour point of
-6.degree. C. or less, and a cloud point of -2.degree. C. or
less.
7. The method of claim 1, wherein the process further comprises
recycling at least a portion of a) the third fraction, b) the
fourth fraction, c) the first catalytically dewaxed effluent, d)
the first fraction, e) the second fraction, or f) a combination of
a plurality of a)-e), as part of i) the at least a portion of the
deasphalted oil, ii) the at least a portion of the first fraction,
iii) the at least a portion of the second fraction, or iv) a
combination of a plurality of i), ii), and iii).
8. The method of claim 1, wherein the hydroprocessing at least a
portion of the first fraction and the hydroprocessing at least a
portion of the second fraction comprises block operation of a
processing system.
9. The method of claim 1, wherein at least one of the second
effective hydroprocessing conditions and the third effective
hydroprocessing conditions further comprises performing aromatic
saturation.
10. The method of claim 1, wherein the yield of deasphalted oil is
at least 55 wt %; or wherein the deasphalted oil has an aromatics
content of at least 55 wt % based on a weight of the deasphalted
oil; or a combination thereof.
11. The method of claim 1, wherein the C.sub.4+ solvent comprises a
C.sub.5+ solvent, a mixture of two or more C.sub.5 isomers, or a
combination thereof.
12. The method of claim 1, wherein a combined conversion of the
feedstock across the first effective hydroprocessing conditions and
the second effective hydroprocessing conditions is at least 70 wt %
relative to 370.degree. C., the second catalytically dewaxed
effluent having a viscosity index of at least 90.
13. The method of claim 12, wherein a combined conversion of the
feedstock across the first effective hydroprocessing conditions and
the third effective hydroprocessing conditions is at least 70 wt %
relative to 370.degree. C., the third catalytically dewaxed
effluent and/or the fourth fraction having a viscosity index of at
least 90.
14. The method of claim 1, wherein at least a portion of the first
fraction, at least a portion of the second fraction, at least a
portion of the first catalytically dewaxed effluent, at least a
portion of the second catalytically dewaxed effluent, or a
combination thereof is used as a feed for a steam cracker.
15. The method of claim 1, wherein at least a portion of the second
catalytically dewaxed effluent is used as an asphalt blend
component.
16. The method of claim 1, wherein separating the hydroprocessed
effluent further comprises forming an additional fraction having a
T.sub.5 distillation point of at least 370.degree. 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.degree. C.+ portion
having a kinematic viscosity at 100.degree. C. of 3.5 cSt or
more.
17. A method for making lubricant base stock, comprising:
performing solvent deasphalting, optionally using a C.sub.4+
solvent, under effective solvent deasphalting conditions on a
feedstock having a T5 boiling point of at least about 370.degree.
C., the effective solvent deasphalting conditions producing a yield
of deasphalted oil of at least about 50 wt % of the feedstock;
hydroprocessing at least a portion of the deasphalted oil under
first effective hydroprocessing conditions to form a hydroprocessed
effluent, the hydroprocessing comprising exposing the at least a
portion of the deasphalted oil to a bulk multimetallic catalyst
under the hydroprocessing conditions, the at least a portion of the
deasphalted oil having an aromatics content of at least about 50 wt
%, 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 the hydroprocessed effluent to form
at least a fuels boiling range fraction, a first fraction having a
T.sub.5 distillation point of at least 370.degree. C., and a second
fraction having a T.sub.5 distillation point of at least
370.degree. C., the second fraction having a higher kinematic
viscosity at 100.degree. 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 first catalytically dewaxed effluent
comprising a 370.degree. C.+ portion having a first kinematic
viscosity at 100.degree. C.; and 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
catalytically dewaxed effluent comprising a 370.degree. C.+ portion
having a second kinematic viscosity at 100.degree. C. that is
greater than the first kinematic viscosity at 100.degree. C.,
wherein the second effective hydroprocessing conditions are
different from the third effective hydroprocessing conditions, and
wherein the bulk multimetallic catalyst comprises of at least one
Group VIII non-noble metal and at least two Group VIB metals and
wherein the ratio of Group VIB metal to Group VIII non-noble metal
is from about 10:1 to about 1:10.
18. The method of claim 17, wherein the Group VIII non-noble metal
is selected from Ni and Co and the Group VIB metals are selected
from Mo and W.
19. The method of claim 17, wherein the bulk multimetallic is
represented by the formula: (X).sub.b(Mo)c(W).sub.dO.sub.x wherein
X is a Group VIII non-noble metal, and the molar ratio of b:(c+d)
is 0.5/1 to 3/1.
20. The method of claim 19, wherein the molar ratio of b:(c+d) is
0.75/1 to 1.5/1.
21. The method of claim 19, wherein the molar ratio of c:d is
>0.01/1.
22. The method of claim 17 wherein the bulk multimetallic catalyst
is essentially an amorphous material having a unique X-ray
diffraction pattern showing crystalline peaks at d=2.53 Angstroms
and d=1.70 Angstroms.
23. The method of claim 17 wherein the bulk multimetallic catalyst
also contains an acid function.
24. The method of claim 17, wherein the second effective
hydroprocessing conditions further comprise hydrocracking
conditions and the third effective hydroprocessing conditions
further comprise hydrocracking conditions, the second effective
hydroprocessing conditions and third effective hydroprocessing
conditions being different based on a difference in at least one of
a hydrocracking pressure, a hydrocracking temperature, a dewaxing
pressure, and a dewaxing temperature.
25. The method of claim 17, further comprising at least one of: a)
solvent extracting at least a portion of the second catalytically
dewaxed effluent to form a solvent processed effluent, or b)
solvent dewaxing at least a portion of the second catalytically
dewaxed effluent to form a solvent processed effluent, wherein the
solvent processed effluent comprises a T5 distillation point of at
least 482.degree. C., a VI of at least 80, a pour point of
-6.degree. C. or less, and a cloud point of -2.degree. C. or
less.
26. The method of claim 17, wherein the process further comprises
recycling at least a portion of a) the third fraction, b) the
fourth fraction, c) the first catalytically dewaxed effluent, d)
the first fraction, e) the second fraction, or f) a combination of
a plurality of a)-e), as part of i) the at least a portion of the
deasphalted oil, ii) the at least a portion of the first fraction,
iii) the at least a portion of the second fraction, or iv) a
combination of a plurality of i), ii), and iii).
27. The method of claim 17, wherein at least a portion of the first
fraction, at least a portion of the second fraction, at least a
portion of the first catalytically dewaxed effluent, at least a
portion of the second catalytically dewaxed effluent, or a
combination thereof is used as a feed for a steam cracker; or
wherein at least a portion of the second catalytically dewaxed
effluent is used as an asphalt blend component.
28. The method of claim 17, wherein separating the hydroprocessed
effluent further comprises forming an additional fraction having a
T.sub.5 distillation point of at least 370.degree. 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.degree. C.+ portion
having a kinematic viscosity at 100.degree. C. of 3.5 cSt or
more.
29. A system for producing a lubricant boiling range product,
comprising: a solvent deasphalting unit comprising a deasphalting
inlet and a deasphalting outlet; a first hydroprocessing stage
comprising a first hydroprocessing inlet and a first
hydroprocessing outlet, the first hydroprocessing inlet being in
fluid communication with the deasphalting outlet, the first
hydroprocessing stage further comprising a sulfided mixed metal
catalyst, a bulk multimetallic catalyst, or a combination thereof;
a first separation stage comprising a first separation inlet and a
plurality of first separation outlets, the first separation inlet
being in fluid communication with the first stage outlet; a
plurality of storage tanks in fluid communication with the
plurality of first separation outlets; a second hydroprocessing
stage comprising a second hydroprocessing inlet and a second
hydroprocessing outlet, the second hydroprocessing inlet being in
intermittent fluid communication with the plurality of storage
tanks; and a second separation stage comprising a second separation
inlet and a plurality of second separation outlets, the second
separation inlet being in fluid communication with the second
hydroprocessing outlet, wherein a) the deasphalting inlet is in
fluid communication with at least one separation outlet of the
plurality of first separation outlets, b) the deasphalting inlet is
in fluid communication with at least one of the plurality of
storage tanks, c) the deasphalting outlet is in fluid communication
with at least one of the plurality of second separation outlets, or
d) a combination thereof.
30. The system of claim 29, wherein the system further comprises a
solvent extraction stage in fluid communication with one or more of
the plurality of second separation outlets.
31. The system of claim 29, wherein the sulfided mixed metal
catalyst comprises a catalyst formed by sulfiding a mixed metal
catalyst precursor composition, the mixed metal catalyst precursor
composition being produced by a) heating a composition comprising
at least one metal from Group 6 of the Periodic Table of the
Elements, at least one metal from Groups 8-10 of the Periodic Table
of the Elements, and a reaction product formed from (i) a first
organic compound containing at least one amine group, and (ii) a
second organic compound separate from said first organic compound
and containing at least one carboxylic acid group to a temperature
from about 195.degree. C. to about 260.degree. C. for a time
sufficient for the first and second organic compounds to form a
reaction product in situ that contains an amide moiety, unsaturated
carbon atoms not present in the first or second organic compounds,
oxygen atoms not present in the first or second organic compounds,
or a combination thereof; b) heating a composition comprising one
metal from Group 6 of the Periodic Table of the Elements, at least
one metal from Groups 8-10 of the Periodic Table of the Elements,
and a reaction product formed from (iii) a first organic compound
containing at least one amine group and at least 10 carbon atoms or
(iv) a second organic compound containing at least one carboxylic
acid group and at least 10 carbon atoms, but not both (iii) and
(iv), wherein the reaction product contains additional unsaturated
carbon atoms, relative to (iii) the first organic compound or (iv)
the second organic compound, wherein the metals of the catalyst
precursor composition are arranged in a crystal lattice, and
wherein the reaction product is not located within the crystal
lattice, to a temperature from about 195.degree. C. to about
260.degree. C. for a time sufficient for the first or second
organic compounds to form a reaction product in situ that contains
unsaturated carbon atoms not present in the first or second organic
compounds, oxygen atoms not present in the first or second organic
compounds, or a combination thereof; or c) heating a composition
comprising at least one metal from Group 6 of the Periodic Table of
the Elements, at least one metal from Groups 8-10 of the Periodic
Table of the Elements, and a pre-formed amide formed from (v) a
first organic compound containing at least one amine group, and
(vi) a second organic compound separate from said first organic
compound and containing at least one carboxylic acid group, to form
at least one of additional in situ unsaturated carbon atoms or in
situ added oxygen atoms not present in the first organic compound,
the second organic compound, or both, but not for so long that the
pre-formed amide substantially decomposes, thereby forming a
catalyst precursor containing at least one of in situ formed
unsaturated carbon atoms or in situ added oxygen atoms.
32. The system of claim 29, wherein the bulk multimetallic catalyst
comprises of at least one Group VIII non-noble metal and at least
two Group VIB metals and wherein the ratio of Group VIB metal to
Group VIII non-noble metal is from about 10:1 to about 1:10.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional
Application Ser. No. 62/439,943 filed Dec. 29, 2016, which is
herein incorporated by reference in its entirety.
[0002] This application is related to three other co-pending U.S.
applications, filed on even date herewith, and identified by the
following Attorney Docket numbers and titles: 2017EM196 entitled
"Block Processing Configurations For Base Stock Production From
Deasphalted Oil"; 2016EM406-US2 entitled "Block Processing For Base
Stock Production From Deasphalted Oil" and 2017EM195 entitled "Base
Stocks And Lubricant Compositions Containing Same". Each of these
co-pending U.S. applications is hereby incorporated by reference
herein in its entirety.
FIELD
[0003] Systems and methods are provided for production of lubricant
oil base stocks from deasphalted oils produced by low severity
deasphalting of resid fractions.
BACKGROUND
[0004] Lubricant base stocks are one of the higher value products
that can be generated from a crude oil or crude oil fraction. The
ability to generate lubricant base stocks of a desired quality is
often constrained by the availability of a suitable feedstock. For
example, most conventional processes for lubricant base stock
production involve starting with a crude fraction that has not been
previously processed under severe conditions, such as a virgin gas
oil fraction from a crude with moderate to low levels of initial
sulfur content.
[0005] In some situations, a deasphalted oil formed by propane
deasphalting of a vacuum resid can be used for additional lubricant
base stock production. Deasphalted oils can potentially be suitable
for production of heavier base stocks, such as bright stocks.
However, the severity of propane deasphalting required in order to
make a suitable feed for lubricant base stock production typically
results in a yield of only about 30 wt % deasphalted oil relative
to the vacuum resid feed.
[0006] U.S. Pat. No. 3,414,506 describes methods for making
lubricating oils by hydrotreating pentane-alcohol-deasphalted short
residue. The methods include performing deasphalting on a vacuum
resid fraction with a deasphalting solvent comprising a mixture of
an alkane, such as pentane, and one or more short chain alcohols,
such as methanol and isopropyl alcohol. The deasphalted oil is then
hydrotreated, followed by solvent extraction to perform sufficient
VI uplift to form lubricating oils.
[0007] U.S. Pat. No. 7,776,206 describes methods for catalytically
processing resids and/or deasphalted oils to form bright stock. A
resid-derived stream, such as a deasphalted oil, is hydroprocessed
to reduce the sulfur content to less than 1 wt % and reduce the
nitrogen content to less than 0.5 wt %. The hydroprocessed stream
is then fractionated to form a heavier fraction and a lighter
fraction at a cut point between 1150.degree. F.-1300.degree. F.
(620.degree. C.-705.degree. C.). The lighter fraction is then
catalytically processed in various manners to form a bright
stock.
SUMMARY
[0008] In various aspects, systems and methods are provided for
block operation during lubricant and/or fuels production from
deasphalted oil, such as deasphalted oil from a solvent
deasphalting process with a yield of deasphalted oil of at least 50
wt %. During "block" operation, a deasphalted oil and/or the
hydroprocessed effluent from an initial processing stage can be
split into a plurality of fractions. The fractions can correspond,
for example, to feed fractions suitable for forming a light neutral
fraction, a heavy neutral fraction, and a bright stock fraction, or
the plurality of fractions can correspond to any other convenient
split into separate fractions. The plurality of separate fractions
can then be processed separately in the process train (or in the
sweet portion of the process train) for forming fuels and/or
lubricant base stocks. The initial stage can optionally include a
bulk hydrotreating catalyst to assist with increasing the space
velocity in the initial stage.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 schematically shows an example of a configuration for
block catalytic processing of deasphalted oil to form lubricant
base stocks.
[0010] FIG. 2 schematically shows an example of a configuration for
block catalytic processing of deasphalted oil to form lubricant
base stocks.
[0011] FIG. 3 schematically shows an example of a configuration for
block catalytic processing of deasphalted oil to form lubricant
base stocks.
[0012] FIG. 4 shows results from processing a pentane deasphalted
oil at various levels of hydroprocessing severity.
[0013] FIG. 5 shows results from processing deasphalted oil in
configurations with various combinations of sour hydrocracking and
sweet hydrocracking.
[0014] FIG. 6 schematically shows an example of a configuration for
catalytic processing of a deasphalted oil to form lubricant base
stocks.
[0015] FIG. 7 schematically shows an example of a configuration for
block catalytic processing of deasphalted oil to form lubricant
base stocks.
DETAILED DESCRIPTION
[0016] All numerical values within the detailed description and the
claims herein are modified by "about" or "approximately" the
indicated value, and take into account experimental error and
variations that would be expected by a person having ordinary skill
in the art.
Overview
[0017] In various aspects, methods are provided for producing Group
I and Group II lubricant base stocks, including Group I and Group
II bright stock, from deasphalted oils generated by low severity
C.sub.4+ deasphalting. Low severity deasphalting as used herein
refers to deasphalting under conditions that result in a high yield
of deasphalted oil (and/or a reduced amount of rejected asphalt or
rock), such as a deasphalted oil yield of at least 50 wt % relative
to the feed to deasphalting, or at least 55 wt %, or at least 60 wt
%, or at least 65 wt %, or at least 70 wt %, or at least 75 wt %.
In contrast with conventional bright stock produced from
deasphalted oil formed at low severity conditions, the Group I and
Group II bright stock described herein can be substantially free
from haze after storage for extended periods of time. This haze
free Group II bright stock can correspond to a bright stock with an
unexpected composition.
[0018] In various additional aspects, methods are provided for
catalytic processing of C.sub.3 deasphalted oils to form Group II
bright stock. Forming Group II bright stock by catalytic processing
can provide a bright stock with unexpected compositional
properties.
[0019] In some conventional processing schemes, a resid fraction
can be deasphalted, with the deasphalted oil used as part of a feed
for forming lubricant base stocks. In conventional processing
schemes a deasphalted oil used as feed for forming lubricant base
stocks is produced using propane deasphalting. This propane
deasphalting corresponds to a "high severity" deasphalting, as
indicated by a typical yield of deasphalted oil of roughly 40 wt %
or less, and often 30 wt % or less, relative to the initial resid
fraction. In a typical lubricant base stock production process, the
deasphalted oil can then be solvent extracted to reduce the
aromatics content, followed by solvent dewaxing to form a base
stock. The low yield of deasphalted oil is based in part on the
inability of conventional methods to produce lubricant base stocks
from lower severity deasphalting that do not form haze over
time.
[0020] In some aspects, it has been discovered that lubricant base
stocks can be produced from deasphalted oil generated at high lift
(i.e., high yield of deasphalted oil) while also producing base
stocks that have little or no tendency to form haze over extended
periods of time. The deasphalted oil can be produced by
deasphalting process that uses a C.sub.4 solvent, a C.sub.5
solvent, a C.sub.6+ solvent, a mixture of two or more C.sub.4+
solvents, or a mixture of two or more C.sub.5+ solvents. The
deasphalting process can further correspond to a process with a
yield of deasphalted oil of at least 50 wt % for a vacuum resid
feed having a T10 distillation point (or optionally a T5
distillation point) of at least 510.degree. C., or a yield of at
least 60 wt %, or at least 65 wt %, or at least 70 wt %. It is
believed that the reduced haze formation is due in part to the
reduced or minimized differential between the pour point and the
cloud point for the base stocks and/or due in part to forming a
bright stock with a cloud point of -5.degree. C. or less.
[0021] In some aspects a deasphalted oil can be hydroprocessed
(hydrotreated and/or hydrocracked and/or demetallated), so that
.about.700.degree. F.+(370.degree. C.+) conversion is 10 wt % to 40
wt %. The hydroprocessed effluent can be fractionated to separate
lower boiling portions from a lubricant base stock boiling range
portion. The lubricant boiling range portion can then be
hydrocracked, dewaxed, and hydrofinished to produce a catalytically
dewaxed effluent. Optionally but preferably, the lubricant boiling
range portion can be underdewaxed, so that the wax content of the
catalytically dewaxed heavier portion or potential bright stock
portion of the effluent is at least 6 wt %, or at least 8 wt %, or
at least 10 wt %. This underdewaxing can also be suitable for
forming light or medium or heavy neutral lubricant base stocks that
do not require further solvent upgrading to form haze free base
stocks. In this discussion, the heavier portion/potential bright
stock portion can roughly correspond to a 538.degree. C.+ portion
of the dewaxed effluent. The catalytically dewaxed heavier portion
of the effluent can then be solvent dewaxed to form a solvent
dewaxed effluent. The solvent dewaxed effluent can be separated to
form a plurality of base stocks with a reduced tendency (such as no
tendency) to form haze over time, including at least a portion of a
Group II bright stock product.
[0022] In other aspects a deasphalted oil can be hydroprocessed
(hydrotreated and/or hydrocracked and/or demetallated), so that
370.degree. C.+ conversion is at least 40 wt %, or at least 50 wt
%. The hydroprocessed effluent can be fractionated to separate
lower boiling portions from a lubricant base stock boiling range
portion. The lubricant base stock boiling range portion can then be
hydrocracked, dewaxed, and hydrofinished to produce a catalytically
dewaxed effluent. The catalytically dewaxed effluent can then be
solvent extracted to form a raffinate. The raffinate can be
separated to form a plurality of base stocks with a reduced
tendency (such as no tendency) to form haze over time, including at
least a portion of a Group I and/or Group II bright stock
product.
[0023] In other aspects, it has been discovered that catalytic
processing can be used to produce Group II bright stock with
unexpected compositional properties from C.sub.3, C.sub.4, C.sub.5,
and/or C.sub.5+ deasphalted oil. The deasphalted oil can be
hydrotreated to reduce the content of heteroatoms (such as sulfur
and nitrogen), followed by catalytic dewaxing under sweet
conditions. Optionally, hydrocracking can be included as part of
the sour hydrotreatment stage and/or as part of the sweet dewaxing
stage.
[0024] Optionally, the systems and methods described herein can be
used in "block" operation to allow for additional improvements in
yield and/or product quality. During "block" operation, a
deasphalted oil and/or the hydroprocessed effluent from the sour
processing stage can be split into a plurality of fractions. The
fractions can correspond, for example, to feed fractions suitable
for forming a light neutral fraction, a heavy neutral fraction, and
a bright stock fraction, or the plurality of fractions can
correspond to any other convenient split into separate fractions.
The plurality of separate fractions can then be processed
separately in the process train (or in the sweet portion of the
process train) for forming lubricant base stocks. For example, the
light neutral portion of the feed can be processed for a period of
time, followed by processing of the heavy neutral portion, followed
by processing of a bright stock portion. During the time period
when one type of fraction is being processed, storage tanks can be
used to hold the remaining fractions.
[0025] Block operation can allow the processing conditions in the
process train to be tailored to each type of lubricant fraction.
For example, the amount of sweet processing stage conversion of the
heavy neutral fraction can be lower than the amount of sweet
processing stage conversion for the light neutral fraction. This
can reflect the fact that heavy neutral lubricant base stocks may
not need as high a viscosity index as light neutral base stocks. In
some aspects, the amount of conversion in the first (sour) stage
can be 25 wt % to 75 wt %, or 30 wt % to 70 wt %, or 25 wt % to 60
wt %, or 40 wt % to 75 wt %. After blocking to form separate feeds
for production of light neutral base stock, heavy neutral base
stock, and bright stock, the amount of second (sweet) stage
conversion can vary depending on the desired product. For light
neutral production, the amount of second stage conversion can be 15
wt % to 50 wt %. For heavy neutral production, the second stage
conversion can be 5 wt % to 25 wt %. For bright stock production,
the second stage conversion can be 40 wt % to 70 wt %. Optionally,
the amount of conversion for the light neutral can be at least 10
wt % greater than the amount of conversion for the heavy neutral,
or at least 15 wt % greater. Optionally, the amount of conversion
for the bright stock can be at least 10 wt % greater than the
amount of conversion for any light neutral or heavy neutral base
stocks derived from blocking of a single feed, or at least 20 wt %
greater.
[0026] Another option for modifying the production of base stocks
can be to recycle a portion of at least one lubricant base stock
product for further processing in the process train. This can
correspond to recycling a portion of a base stock product for
further processing in the sour stage and/or recycling a portion of
a base stock product for further processing in the corresponding
sweet stage. Optionally, a base stock product can be recycled for
further processing in a different phase of block operation, such as
recycling light neutral base stock product formed during block
processing of the heavy neutral fraction for further processing
during block processing of the light neutral fraction. The amount
of base stock product recycled can correspond to any convenient
amount of a base stock product effluent from the fractionator, such
as 1 wt % to 50 wt % of a base stock product effluent, or 1 wt % to
20 wt %.
[0027] Recycling a portion of a base stock product effluent can
optionally be used while operating a lube processing system at
higher than typical levels of fuels conversion. When using a
conventional feed for lubricant production, total conversion of
feed relative to 370.degree. C. can be limited to 65 wt % or less.
Conversion of more than 65 wt % of a feed relative to 370.degree.
C. is typically not favored due to loss of viscosity index with
additional conversion. At elevated levels of conversion, the loss
of VI with additional conversion is believed to be due to cracking
and/or conversion of isoparaffins within a feed. For feeds derived
from deasphalted oil, however, the amount of isoparaffins within a
feed is lower than a conventional feed. As a result, additional
conversion can be performed without loss of VI. In some aspects,
converting at least 70 wt % of a feed, or at least 75 wt %, or at
least 80 wt % can allow for production of lubricant base stocks
with substantially improved cold flow properties while still
maintaining the viscosity index of the products at a similar value
to the viscosity index at a conventional conversion of 60 wt %.
[0028] In various aspects, a variety of combinations of catalytic
and/or solvent processing can be used to form lubricant base
stocks, including Group II bright stock, from deasphalted oils.
These combinations include, but are not limited to:
[0029] a) Hydroprocessing of a deasphalted oil under sour
conditions (i.e., sulfur content of at least 500 wppm); separation
of the hydroprocessed effluent to form at least a lubricant boiling
range fraction; and catalytic dewaxing of the lubricant boiling
range fraction under sweet conditions (i.e., 500 wppm or less
sulfur). The catalytic dewaxing can optionally correspond to
catalytic dewaxing using a dewaxing catalyst with a pore size
greater than 8.4 Angstroms. Optionally, the sweet processing
conditions can further include hydrocracking, noble metal
hydrotreatment, and/or hydrofinishing. The optional hydrocracking,
noble metal hydrotreatment, and/or hydrofinishing can occur prior
to and/or after or after catalytic dewaxing. For example, the order
of catalytic processing under sweet processing conditions can be
noble metal hydrotreating followed by hydrocracking followed by
catalytic dewaxing.
[0030] b) The process of a) above, followed by performing an
additional separation on at least a portion of the catalytically
dewaxed effluent. The additional separation can correspond to
solvent dewaxing, solvent extraction (such as solvent extraction
with furfural or n-methylpyrollidone), a physical separation such
as ultracentrifugation, or a combination thereof.
[0031] Group I base stocks or base oils are defined as base stocks
with less than 90 wt % saturated molecules and/or at least 0.03 wt
% sulfur content. Group I base stocks also have a viscosity index
(VI) of at least 80 but less than 120. Group II base stocks or base
oils contain at least 90 wt % saturated molecules and less than
0.03 wt % sulfur. Group II base stocks also have a viscosity index
of at least 80 but less than 120. Group III base stocks or base
oils contain at least 90 wt % saturated molecules and less than
0.03 wt % sulfur, with a viscosity index of at least 120.
[0032] In some aspects, a Group III base stock as described herein
may correspond to a Group III+base stock. Although a generally
accepted definition is not available, a Group III+base stock can
generally correspond to a base stock that satisfies the
requirements for a Group III base stock while also having at least
one property that is enhanced relative to a Group III
specification. The enhanced property can correspond to, for
example, having a viscosity index that is substantially greater
than the required specification of 120, such as a Group III base
stock having a VI of at least 130, or at least 135, or at least
140. Similarly, in some aspects, a Group II base stock as described
herein may correspond to a Group II+base stock. Although a
generally accepted definition is not available, a Group II+base
stock can generally correspond to a base stock that satisfies the
requirements for a Group II base stock while also having at least
one property that is enhanced relative to a Group II specification.
The enhanced property can correspond to, for example, having a
viscosity index that is substantially greater than the required
specification of 80, such as a Group II base stock having a VI of
at least 103, or at least 108, or at least 113.
[0033] In the discussion below, a stage can correspond to a single
reactor or a plurality of reactors. Optionally, multiple parallel
reactors can be used to perform one or more of the processes, or
multiple parallel reactors can be used for all processes in a
stage. Each stage and/or reactor can include one or more catalyst
beds containing hydroprocessing catalyst. Note that a "bed" of
catalyst in the discussion below can refer to a partial physical
catalyst bed. For example, a catalyst bed within a reactor could be
filled partially with a hydrocracking catalyst and partially with a
dewaxing catalyst. For convenience in description, even though the
two catalysts may be stacked together in a single catalyst bed, the
hydrocracking catalyst and dewaxing catalyst can each be referred
to conceptually as separate catalyst beds.
[0034] In this discussion, conditions may be provided for various
types of hydroprocessing of feeds or effluents. Examples of
hydroprocessing can include, but are not limited to, one or more of
hydrotreating, hydrocracking, catalytic dewaxing, and
hydrofinishing/aromatic saturation. Such hydroprocessing conditions
can be controlled to have desired values for the conditions (e.g.,
temperature, pressure, LHSV, treat gas rate) by using at least one
controller, such as a plurality of controllers, to control one or
more of the hydroprocessing conditions. In some aspects, for a
given type of hydroprocessing, at least one controller can be
associated with each type of hydroprocessing condition. In some
aspects, one or more of the hydroprocessing conditions can be
controlled by an associated controller. Examples of structures that
can be controlled by a controller can include, but are not limited
to, valves that control a flow rate, a pressure, or a combination
thereof; heat exchangers and/or heaters that control a temperature;
and one or more flow meters and one or more associated valves that
control relative flow rates of at least two flows. Such controllers
can optionally include a controller feedback loop including at
least a processor, a detector for detecting a value of a control
variable (e.g., temperature, pressure, flow rate, and a processor
output for controlling the value of a manipulated variable (e.g.,
changing the position of a valve, increasing or decreasing the duty
cycle and/or temperature for a heater). Optionally, at least one
hydroprocessing condition for a given type of hydroprocessing may
not have an associated controller.
[0035] In this discussion, unless otherwise specified a lubricant
boiling range fraction corresponds to a fraction having an initial
boiling point or alternatively a T5 boiling point of at least about
370.degree. C. (.about.700.degree. F.). A distillate fuel boiling
range fraction, such as a diesel product fraction, corresponds to a
fraction having a boiling range from about 193.degree. C.
(375.degree. F.) to about 370.degree. C. (.about.700.degree. F.).
Thus, distillate fuel boiling range fractions (such as distillate
fuel product fractions) can have initial boiling points (or
alternatively T5 boiling points) of at least about 193.degree. C.
and final boiling points (or alternatively T95 boiling points) of
about 370.degree. C. or less. A naphtha boiling range fraction
corresponds to a fraction having a boiling range from about
36.degree. C. (122.degree. F.) to about 193.degree. C. (375.degree.
F.) to about 370.degree. C. (.about.700.degree. F.). Thus, naphtha
fuel product fractions can have initial boiling points (or
alternatively T5 boiling points) of at least about 36.degree. C.
and final boiling points (or alternatively T95 boiling points) of
about 193.degree. C. or less. It is noted that 36.degree. C.
roughly corresponds to a boiling point for the various isomers of a
C5 alkane. A fuels boiling range fraction can correspond to a
distillate fuel boiling range fraction, a naphtha boiling range
fraction, or a fraction that includes both distillate fuel boiling
range and naphtha boiling range components. Light ends are defined
as products with boiling points below about 36.degree. C., which
include various C1-C4 compounds. When determining a boiling point
or a boiling range for a feed or product fraction, an appropriate
ASTM test method can be used, such as the procedures described in
ASTM D2887, D2892, and/or D86. Preferably, ASTM D2887 should be
used unless a sample is not appropriate for characterization based
on ASTM D2887. For example, for samples that will not completely
elute from a chromatographic column, ASTM D7169 can be used.
Process Variations
[0036] In various aspects, hydroprocessing of deasphalted oil to
form lubricant base stocks can result in formation of a variety of
products. In addition to light neutral, heavy neutral, and bright
stock products formed by block processing, additional fuels and
lubricant products can be formed. The fuels products can include
naphtha and diesel fractions formed due to conversion in the sour
stage and conversion in the sweet stage. The sour stage fuels
products can optionally be processed further, if necessary, in
order to satisfy desired standards for sulfur and nitrogen content.
The additional lubricant products can include additional light
neutral and heavy neutral products that are formed during block
processing. For example, sweet stage processing of the heavy
neutral block feed can result in some "conversion" of heavy neutral
base stock to light neutral base stock. Similarly, sweet stage
processing of the bright stock block feed can result in some
"conversion" of bright stock to light neutral base stock and/or
heavy neutral base stock.
[0037] In some aspects, alternative types of products and/or
product dispositions can be generated in conjunction with
hydroprocessing of a deasphalted oil. For example, various sour
stage and/or sweet stage effluents can be suitable for use as a
steam cracker feed. Both the sour stage hydrocrackate and the
basestock products, particularly the heavy diesel and naphtha,
and/or any narrow boiling range fractions that may be distilled in
between lube cuts to manage lube properties, can make suitable
steam cracker feeds. It could be a single component, a blend of a
few components, or the entire sour stage product which may be sent
to a steam cracker. Such a steam cracker feed can have 98 wt % or
more saturates for the sweet products and 75 wt % or more saturates
for the hydrocrackates, which can be beneficial in a steam cracker
feed. Additionally, such a feed can be low in sulfur which can
reduce or minimize tar formation.
[0038] As another example, the bright stock product can be used as
an unexpectedly beneficial fluxant for asphalt production. The
bright stock is sufficiently heavy to avoid mass loss, has low
viscosity, and although the saturates content is relatively high,
because it is dewaxed it has very low wax. Wax is a detrimental
quality for asphalt, and most low viscosity fluxes for asphalt type
streams that are also non-toxic, like vacuum gas oils, have
significant quantities of wax. This can make a bright stock made
according to the processes described herein a suitable flux for a
high asphaltene, high viscosity asphalt blend component, such as
deasphalter rock, or deasphalter rock from a high-lift
deasphalter.
[0039] In various aspects, the sweet stage of the reaction system
can include a hydrocracking catalyst followed (downstream) by a
dewaxing catalyst followed by an aromatic saturation catalyst. For
example, the sweet stage of a reaction system can include a first
reactor containing hydrocracking catalyst, a second reactor
containing dewaxing catalyst, and a third reactor containing
aromatic saturation catalyst. In some aspects, other types of
catalyst configurations in the sweet stage can be beneficial.
[0040] As an example, the first reactor in the sweet stage can
include a hydrocracking catalyst followed by an aromatic saturation
catalyst. Including both hydrocracking and aromatic saturation
functionality in the initial part of the sweet stage can be
beneficial for allowing boiling point conversion and/or viscosity
index upgrading that can be tailored for each type of blocked feed.
Because this reactor is a sweet processing stage, the temperature
can be relatively low, thus allowing effective aromatic saturation
(reduced amount of constraint due to equilibrium) while still being
able to achieve desired boiling point conversion and/or viscosity
index upgrading.
[0041] As another example, the initial reactor or portion of the
sweet stage can include an aromatic saturation catalyst without the
presence of a hydrocracking catalyst. This type of configuration
can provide superior yield for basestocks that do not require
additional viscosity index upgrade in the sweet stage. Additionally
or alternately, at end of run, the lack of a hydrocracking catalyst
can allow the sweet stage reactors (or at least the initial
reactor) to be operated to be operated at higher temperature to
achieve desired aromatic saturation without excessive cracking.
[0042] In various aspects, the sour stage of the reaction system
can include one or more optional demetallization catalysts followed
(downstream) by a hydrotreating catalyst followed by a
hydrocracking catalyst. In some aspects, a large pore catalyst,
such as a demetallization catalyst, can be included downstream from
the hydrocracking catalyst. Such a large pore catalyst downstream
from the hydrocracking catalyst can be beneficial due to the
differences between a feed corresponding to a high yield
deasphalted oil and a conventional feed for lubricant production.
During processing of a conventional feed for lubricant production,
removal of mercaptans can potentially pose a challenge at the end
of a sour stage. A conventional hydrotreating catalyst after a
hydrocracking catalyst can be suitable for removal of such
mercaptans. For a feed based on a deasphalted oil, the
substantially higher percentage of multi-ring structures in the
feed can result in formation of polynuclear aromatics during
hydrocracking. Such polynuclear aromatics are not as readily
treated using a conventional hydrotreating catalyst. However, the
larger pore size of a demetallization catalyst (such as 200 nm or
greater median pore size) can be allow demetallization catalysts to
be effective for saturation of polynuclear aromatics. Such
demetallization catalysts can also be effective for mercaptan
removal.
Feedstocks
[0043] In various aspects, at least a portion of a feedstock for
processing as described herein can correspond to a vacuum resid
fraction or another type 950.degree. F.+(510.degree. C.+) or
1000.degree. F.+(538.degree. C.+) fraction. Another example of a
method for forming a 950.degree. F.+(510.degree. C.+) or
1000.degree. F.+(538.degree. C.+) fraction is to perform a high
temperature flash separation. The 950.degree. F.+(510.degree. C.+)
or 1000.degree. F.+(538.degree. C.+) fraction formed from the high
temperature flash can be processed in a manner similar to a vacuum
resid.
[0044] A vacuum resid fraction or a 950.degree. F.+(510.degree.
C.+) fraction formed by another process (such as a flash
fractionation bottoms or a bitumen fraction) can be deasphalted at
low severity to form a deasphalted oil. Optionally, the feedstock
can also include a portion of a conventional feed for lubricant
base stock production, such as a vacuum gas oil.
[0045] A vacuum resid (or other 510.degree. C.+) fraction can
correspond to a fraction with a T5 distillation point (ASTM D2892,
or ASTM D7169 if the fraction will not completely elute from a
chromatographic system) of at least about 900.degree. F.
(482.degree. C.), or at least 950.degree. F. (510.degree. C.), or
at least 1000.degree. F. (538.degree. C.). Alternatively, a vacuum
resid fraction can be characterized based on a T10 distillation
point (ASTM D2892/D7169) of at least about 900.degree. F.
(482.degree. C.), or at least 950.degree. F. (510.degree. C.), or
at least 1000.degree. F. (538.degree. C.).
[0046] Resid (or other 510.degree. C.+) fractions can be high in
metals. For example, a resid fraction can be high in total nickel,
vanadium and iron contents. In an aspect, a resid fraction can
contain at least 0.00005 grams of Ni/V/Fe (50 wppm) or at least
0.0002 grams of Ni/V/Fe (200 wppm) per gram of resid, on a total
elemental basis of nickel, vanadium and iron. In other aspects, the
heavy oil can contain at least 500 wppm of nickel, vanadium, and
iron, such as up to 1000 wppm or more.
[0047] Contaminants such as nitrogen and sulfur are typically found
in resid (or other 510.degree. C.+) fractions, often in
organically-bound form. Nitrogen content can range from about 50
wppm to about 10,000 wppm elemental nitrogen or more, based on
total weight of the resid fraction. Sulfur content can range from
500 wppm to 100,000 wppm elemental sulfur or more, based on total
weight of the resid fraction, or from 1000 wppm to 50,000 wppm, or
from 1000 wppm to 30,000 wppm.
[0048] Still another method for characterizing a resid (or other
510.degree. C.+) fraction is based on the Conradson carbon residue
(CCR) of the feedstock. The Conradson carbon residue of a resid
fraction can be at least about 5 wt %, such as at least about 10 wt
% or at least about 20 wt %. Additionally or alternately, the
Conradson carbon residue of a resid fraction can be about 50 wt %
or less, such as about 40 wt % or less or about 30 wt % or
less.
[0049] In some aspects, a vacuum gas oil fraction can be
co-processed with a deasphalted oil. The vacuum gas oil can be
combined with the deasphalted oil in various amounts ranging from
20 parts (by weight) deasphalted oil to 1 part vacuum gas oil
(i.e., 20:1) to 1 part deasphalted oil to 1 part vacuum gas oil. In
some aspects, the ratio of deasphalted oil to vacuum gas oil can be
at least 1:1 by weight, or at least 1.5:1, or at least 2:1. Typical
(vacuum) gas oil fractions can include, for example, fractions with
a T5 distillation point to T95 distillation point of 650.degree. F.
(343.degree. C.)--1050.degree. F. (566.degree. C.) or 650.degree.
F. (343.degree. C.)--1000.degree. F. (538.degree. C.) or
650.degree. F. (343.degree. C.)--950.degree. F. (510.degree. C.),
or 650.degree. F. (343.degree. C.)--900.degree. F. (482.degree.
C.), or -700.degree. F. (370.degree. C.)--1050.degree. F.
(566.degree. C.), or -700.degree. F. (370.degree. C.)--1000.degree.
F. (538.degree. C.) or -700.degree. F. (370.degree.
C.)--950.degree. F. (510.degree. C.) or -700.degree. F.
(370.degree. C.)--900.degree. F. (482.degree. C.), or 750.degree.
F. (399.degree. C.)--1050.degree. F. (566.degree. C.), or
750.degree. F. (399.degree. C.)--1000.degree. F. (538.degree. C.),
or 750.degree. F. (399.degree. C.)--950.degree. F. (510.degree.
C.), or 750.degree. F. (399.degree. C.)--900.degree. F.
(482.degree. C.). For example a suitable vacuum gas oil fraction
can have a T5 distillation point of at least 343.degree. C. and a
T95 distillation point of 566.degree. C. or less; or a T10
distillation point of at least 343.degree. C. and a T90
distillation point of 566.degree. C. or less; or a T5 distillation
point of at least 370.degree. C. and a T95 distillation point of
566.degree. C. or less; or a T5 distillation point of at least
343.degree. C. and a T95 distillation point of 538.degree. C. or
less.
Solvent Deasphalting
[0050] Solvent deasphalting is a solvent extraction process. In
some aspects, suitable solvents for methods as described herein
include alkanes or other hydrocarbons (such as alkenes) containing
4 to 7 carbons per molecule. Examples of suitable solvents include
n-butane, isobutane, n-pentane, C.sub.4+ alkanes, C.sub.5+ alkanes,
C.sub.4+ hydrocarbons, and C.sub.5+ hydrocarbons. In other aspects,
suitable solvents can include C.sub.3 hydrocarbons, such as
propane. In such other aspects, examples of suitable solvents
include propane, n-butane, isobutane, n-pentane, C.sub.3+ alkanes,
C.sub.4+ alkanes, C.sub.5+ alkanes, C.sub.3+ hydrocarbons, C.sub.4+
hydrocarbons, and C.sub.5+ hydrocarbons
[0051] In this discussion, a solvent comprising C.sub.n
(hydrocarbons) is defined as a solvent composed of at least 80 wt %
of alkanes (hydrocarbons) having n carbon atoms, or at least 85 wt
%, or at least 90 wt %, or at least 95 wt %, or at least 98 wt %.
Similarly, a solvent comprising C.sub.n+ (hydrocarbons) is defined
as a solvent composed of at least 80 wt % of alkanes (hydrocarbons)
having n or more carbon atoms, or at least 85 wt %, or at least 90
wt %, or at least 95 wt %, or at least 98 wt %.
[0052] In this discussion, a solvent comprising C.sub.n alkanes
(hydrocarbons) is defined to include the situation where the
solvent corresponds to a single alkane (hydrocarbon) containing n
carbon atoms (for example, n=3, 4, 5, 6, 7) as well as the
situations where the solvent is composed of a mixture of alkanes
(hydrocarbons) containing n carbon atoms. Similarly, a solvent
comprising C.sub.n+ alkanes (hydrocarbons) is defined to include
the situation where the solvent corresponds to a single alkane
(hydrocarbon) containing n or more carbon atoms (for example, n=3,
4, 5, 6, 7) as well as the situations where the solvent corresponds
to a mixture of alkanes (hydrocarbons) containing n or more carbon
atoms. Thus, a solvent comprising C.sub.4+ alkanes can correspond
to a solvent including n-butane; a solvent include n-butane and
isobutane; a solvent corresponding to a mixture of one or more
butane isomers and one or more pentane isomers; or any other
convenient combination of alkanes containing 4 or more carbon
atoms. Similarly, a solvent comprising C.sub.5+ alkanes
(hydrocarbons) is defined to include a solvent corresponding to a
single alkane (hydrocarbon) or a solvent corresponding to a mixture
of alkanes (hydrocarbons) that contain 5 or more carbon atoms.
Alternatively, other types of solvents may also be suitable, such
as supercritical fluids. In various aspects, the solvent for
solvent deasphalting can consist essentially of hydrocarbons, so
that at least 98 wt % or at least 99 wt % of the solvent
corresponds to compounds containing only carbon and hydrogen. In
aspects where the deasphalting solvent corresponds to a C.sub.4+
deasphalting solvent, the C.sub.4+ deasphalting solvent can include
less than 15 wt % propane and/or other C.sub.3 hydrocarbons, or
less than 10 wt %, or less than 5 wt %, or the C.sub.4+
deasphalting solvent can be substantially free of propane and/or
other C.sub.3 hydrocarbons (less than 1 wt %). In aspects where the
deasphalting solvent corresponds to a C.sub.5+ deasphalting
solvent, the C.sub.5+ deasphalting solvent can include less than 15
wt % propane, butane and/or other C.sub.3-C.sub.4 hydrocarbons, or
less than 10 wt %, or less than 5 wt %, or the C.sub.5+
deasphalting solvent can be substantially free of propane, butane,
and/or other C.sub.3-C.sub.4 hydrocarbons (less than 1 wt %). In
aspects where the deasphalting solvent corresponds to a C.sub.3+
deasphalting solvent, the C.sub.3+ deasphalting solvent can include
less than 10 wt % ethane and/or other C.sub.2 hydrocarbons, or less
than 5 wt %, or the C.sub.3+ deasphalting solvent can be
substantially free of ethane and/or other C.sub.2 hydrocarbons
(less than 1 wt %).
[0053] Deasphalting of heavy hydrocarbons, such as vacuum resids,
is known in the art and practiced commercially. A deasphalting
process typically corresponds to contacting a heavy hydrocarbon
with an alkane solvent (propane, butane, pentane, hexane, heptane
etc and their isomers), either in pure form or as mixtures, to
produce two types of product streams. One type of product stream
can be a deasphalted oil extracted by the alkane, which is further
separated to produce deasphalted oil stream. A second type of
product stream can be a residual portion of the feed not soluble in
the solvent, often referred to as rock or asphaltene fraction. The
deasphalted oil fraction can be further processed into make fuels
or lubricants. The rock fraction can be further used as blend
component to produce asphalt, fuel oil, and/or other products. The
rock fraction can also be used as feed to gasification processes
such as partial oxidation, fluid bed combustion or coking
processes. The rock can be delivered to these processes as a liquid
(with or without additional components) or solid (either as pellets
or lumps).
[0054] During solvent deasphalting, a resid boiling range feed
(optionally also including a portion of a vacuum gas oil feed) can
be mixed with a solvent. Portions of the feed that are soluble in
the solvent are then extracted, leaving behind a residue with
little or no solubility in the solvent. The portion of the
deasphalted feedstock that is extracted with the solvent is often
referred to as deasphalted oil. Typical solvent deasphalting
conditions include mixing a feedstock fraction with a solvent in a
weight ratio of from about 1:2 to about 1:10, such as about 1:8 or
less. Typical solvent deasphalting temperatures range from
40.degree. C. to 200.degree. C., or 40.degree. C. to 150.degree.
C., depending on the nature of the feed and the solvent. The
pressure during solvent deasphalting can be from about 50 psig (345
kPag) to about 500 psig (3447 kPag).
[0055] It is noted that the above solvent deasphalting conditions
represent a general range, and the conditions will vary depending
on the feed. For example, under typical deasphalting conditions,
increasing the temperature can tend to reduce the yield while
increasing the quality of the resulting deasphalted oil. Under
typical deasphalting conditions, increasing the molecular weight of
the solvent can tend to increase the yield while reducing the
quality of the resulting deasphalted oil, as additional compounds
within a resid fraction may be soluble in a solvent composed of
higher molecular weight hydrocarbons. Under typical deasphalting
conditions, increasing the amount of solvent can tend to increase
the yield of the resulting deasphalted oil. As understood by those
of skill in the art, the conditions for a particular feed can be
selected based on the resulting yield of deasphalted oil from
solvent deasphalting. In aspects where a C.sub.3 deasphalting
solvent is used, the yield from solvent deasphalting can be 40 wt %
or less. In some aspects, C.sub.4 deasphalting can be performed
with a yield of deasphalted oil of 50 wt % or less, or 40 wt % or
less. In various aspects, the yield of deasphalted oil from solvent
deasphalting with a C.sub.4+ solvent can be at least 50 wt %
relative to the weight of the feed to deasphalting, or at least 55
wt %, or at least 60 wt % or at least 65 wt %, or at least 70 wt %.
In aspects where the feed to deasphalting includes a vacuum gas oil
portion, the yield from solvent deasphalting can be characterized
based on a yield by weight of a 950.degree. F.+(510.degree. C.)
portion of the deasphalted oil relative to the weight of a
510.degree. C.+ portion of the feed. In such aspects where a
C.sub.4+ solvent is used, the yield of 510.degree. C.+ deasphalted
oil from solvent deasphalting can be at least 40 wt % relative to
the weight of the 510.degree. C.+ portion of the feed to
deasphalting, or at least 50 wt %, or at least 55 wt %, or at least
60 wt % or at least 65 wt %, or at least 70 wt %. In such aspects
where a C.sub.4- solvent is used, the yield of 510.degree. C.+
deasphalted oil from solvent deasphalting can be 50 wt % or less
relative to the weight of the 510.degree. C.+ portion of the feed
to deasphalting, or 40 wt % or less, or 35 wt % or less.
Multimetallic Catalyst and Forming Multimetallic Catalyst from a
Precursor Including Organic Components
[0056] As used herein, the term "bulk", when describing a mixed
metal oxide catalyst composition, indicates that the catalyst
composition is self-supporting in that it does not require a
carrier or support. It is well understood that bulk catalysts may
have some minor amount of carrier or support material in their
compositions (e.g., about 20 wt % or less, about 15 wt % or less,
about 10 wt % or less, about 5 wt % or less, or substantially no
carrier or support, based on the total weight of the catalyst
composition); for instance, bulk hydroprocessing catalysts may
contain a minor amount of a binder, e.g., to improve the physical
and/or thermal properties of the catalyst. In contrast,
heterogeneous or supported catalyst systems typically comprise a
carrier or support onto which one or more catalytically active
materials are deposited, often using an impregnation or coating
technique. Nevertheless, heterogeneous catalyst systems without a
carrier or support (or with a minor amount of carrier or support)
are generally referred to as bulk catalysts and are frequently
formed by co-precipitation or solid-solid reactions in
slurries.
[0057] In various aspects, the methods described herein can include
use of a catalyst formed from a catalyst precursor composition
comprising at least one metal from Group 6 of the Periodic Table of
the Elements, at least one metal from Groups 8-10 of the Periodic
Table of the Elements. The catalyst precursor compositions can
either further include a reaction product, or the catalyst
precursor can be treated with compounds used to form such a
reaction product in situ.
[0058] The reaction product can be formed in various manners. In
some aspects, the reaction product can be formed from (i) a first
organic compound containing at least one amine group and at least
10 carbons or (ii) a second organic compound containing at least
one carboxylic acid group and at least 10 carbons, but not both (i)
and (ii), wherein the reaction product contains additional
unsaturated carbon atoms, relative to (i) the first organic
compound or (ii) the second organic compound, wherein the metals of
the catalyst precursor composition are arranged in a crystal
lattice, and wherein the reaction product is not located within the
crystal lattice. Additionally or alternately, in some aspects the
reaction product can be formed from (i) a first organic compound
containing at least one amine group, and (ii) a second organic
compound separate from said first organic compound and containing
at least one carboxylic acid group. More broadly, this type of
aspect relates to use of a catalyst formed from a catalyst
precursor composition comprising at least one metal from Group 6 of
the Periodic Table of the Elements, at least one metal from Groups
8-10 of the Periodic Table of the Elements, and a condensation
reaction product formed from (i) a first organic compound
containing at least one first functional group, and (ii) a second
organic compound separate from said first organic compound and
containing at least one second functional group, wherein said first
functional group and said second functional group are capable of
undergoing a condensation reaction and/or a (decomposition)
reaction causing an additional unsaturation to form an associated
product. Though the description above and herein often refers
specifically to the condensation reaction product being an amide,
it should be understood that any in situ condensation reaction
product formed can be substituted for the amide described herein.
For example, if the first functional group is a hydroxyl group and
the second functional group is a carboxylic acid or an acid
chloride or an organic ester capable of undergoing
transesterification with the hydroxyl group, then the in situ
condensation reaction product formed would be an ester. When this
reaction product is an amide, the presence of the reaction product
in any intermediate or final composition can be determined by
methods well known in the art, e.g., by infrared spectroscopy
(FTIR) techniques. When this reaction product contains additional
unsaturation(s) not present in the first and second organic
compounds, e.g., from at least partial
decomposition/dehydrogenation at conditions including elevated
temperatures, the presence of the additional unsaturation(s) in any
intermediate or final composition can be determined by methods well
known in the art, e.g., by FTIR and/or nuclear magnetic resonance
(.sup.13C NMR) techniques. This catalyst precursor composition can
be a bulk metal catalyst precursor composition or a heterogeneous
(supported) metal catalyst precursor composition.
[0059] This catalyst precursor composition can be a bulk metal
catalyst precursor composition or a supported metal catalyst
precursor composition. When it is a bulk mixed metal catalyst
precursor composition, the reaction product can be obtained by
heating the composition (though specifically the amine-containing
compound or the carboxylic acid-containing compound) to a
temperature from about 195.degree. C. to about 260.degree. C. for a
time sufficient for the first or second organic compounds to react
to form additional in situ unsaturated carbon atoms and/or become
more oxidized than the first or second organic compounds, but not
for so long that more than 50% by weight of the first or second
organic compound is volatilized, thereby forming a catalyst
precursor composition that contains in situ formed unsaturated
carbon atoms and/or that is further oxidized.
[0060] A bulk mixed metal hydroprocessing catalyst composition can
be produced from this bulk mixed metal catalyst precursor
composition by sulfiding it under sufficient sulfiding conditions,
which sulfiding should begin in the presence of the in situ
additionally unsaturated reaction product (which may result from at
least partial decomposition, e.g., via oxidative dehydrogenation in
the presence of oxygen and/or via non-oxidative dehydrogenation in
the absence of an appropriate concentration of oxygen, of
typically-unfunctionalized organic portions of the first or second
organic compounds, e.g., of an aliphatic portion of an organic
compound and/or through conjugation/aromatization of unsaturations
expanding upon an unsaturated portion of an organic compound).
[0061] When the catalyst precursor is a bulk mixed metal catalyst
precursor composition that includes an ex situ or in situ formed
amide, the thermal treatment of the amide-impregnated metal oxide
component is carried out by heating the impregnated composition to
a temperature and for a time which does not result in gross
decomposition of the amide, although additional unsaturation may
arise from partial in situ decomposition; the temperature is
typically from about 195.degree. C. to about 250.degree. C. (or
optionally about 195.degree. C. to about 260.degree. C.), but
higher temperatures, e.g. in the range of 250 to 280.degree. C.,
can be used in order to abbreviate the duration of the heating
although due care is required to avoid the gross decomposition of
the pre-formed amide, as discussed further below. The bulk mixed
metal hydroprocessing catalyst can be produced from this precursor
by sulfiding it with the sulfiding taking place with the amide
present on the metal oxide component (i.e., when the thermally
treated amide, is substantially present and/or preferably not
significantly decomposed by the beginning of the sulfiding step).
Additional unsaturation may be present in the organic component of
the catalyst precursor resulting from a variety of mechanisms
including partial decomposition, (e.g., via oxidative
dehydrogenation in the presence of oxygen and/or via non-oxidative
dehydrogenation in the absence of an appropriate concentration of
oxygen), of typically-unfunctionalized organic portions of the
amide and/or through conjugation/aromatization of unsaturations
expanding upon an unsaturated portion the amide. The treated
organic component may also contain additional oxygen in addition to
the unsaturation when the treatment is carried out in an oxidizing
atmosphere.
[0062] Catalyst precursor compositions and hydroprocessing catalyst
compositions useful in various aspects of the present invention can
advantageously comprise (or can have metal components that consist
essentially of) at least one metal from Group 6 of the Periodic
Table of Elements and at least one metal from Groups 8-10 of the
Periodic Table of Elements, and optionally at least one metal from
Group 5 of the Periodic Table of Elements. Generally, these metals
are present in their substantially fully oxidized form, which can
typically take the form of simple metal oxides, but which may be
present in a variety of other oxide forms, e.g., such as
hydroxides, oxyhydroxides, oxycarbonates, carbonates, oxynitrates,
oxysulfates, or the like, or some combination thereof. In one
preferred embodiment, the Group 6 metal(s) can be Mo and/or W, and
the Group 8-10 metal(s) can be Co and/or Ni. Generally, the atomic
ratio of the Group 6 metal(s) to the metal(s) of Groups 8-10 can be
from about 2:1 to about 1:3, for example from about 5:4 to about
1:2, or from about 20:19 to about 3:4. When the composition further
comprises at least one metal from Group 5, that at least one metal
can be V and/or Nb. When present, the amount of Group 5 metal(s)
can be such that the atomic ratio of the Group 6 metal(s) to the
Group 5 metal(s) can be from about 99:1 to about 1:1, for example
from about 99:1 to about 5:1, from about 99:1 to about 10:1, or
from about 99:1 to about 20:1. Additionally or alternately, when
Group 5 metal(s) is(are) present, the atomic ratio of the sum of
the Group 5 metal(s) plus the Group (6) metal(s) compared to the
metal(s) of Groups 8-10 can be from about 2:1 to about 1:3, for
example from about 5:4 to about 1:2, or from about 20:19 to about
3:4.
[0063] The metals in the catalyst precursor compositions and in the
hydroprocessing catalyst compositions according to the invention
can be present in any suitable form prior to sulfiding, but can
often be provided as metal oxides. When provided as bulk mixed
metal oxides, such bulk oxide components of the catalyst precursor
compositions and of the hydroprocessing catalyst compositions
according to the invention can be prepared by any suitable method
known in the art, but can generally be produced by forming a
slurry, typically an aqueous slurry, comprising (1) (a) an oxyanion
of the Group 6 metal(s), such as a tungstate and/or a molybdate, or
(b) an insoluble (oxide, acid) form of the Group 6 metal(s), such
as tungstic acid and/or molybdenum trioxide, (2) a salt of the
Group 8-10 metal(s), such as nickel carbonate, and optionally, when
present, (3) (a) a salt or oxyanion of a Group 5 metal, such as a
vanadate and/or a niobate, or (b) insoluble (oxide, acid) form of a
Group 5 metal, such as niobic acid and/or diniobium pentoxide. The
slurry can be heated to a suitable temperature, such as from about
60.degree. C. to about 150.degree. C., at a suitable pressure,
e.g., at atmospheric or autogenous pressure, for an appropriate
time, e.g., about 4 hours to about 24 hours.
[0064] Non-limiting examples of suitable mixed metal oxide
compositions can include, but are not limited to, nickel-tungsten
oxides, cobalt-tungsten oxides, nickel-molybdenum oxides,
cobalt-molybdenum oxides, nickel-molybdenum-tungsten oxides,
cobalt-molybdenum-tungsten oxides, cobalt-nickel-tungsten oxides,
cobalt-nickel-molybdenum oxides, cobalt-nickel-tungsten-molybdenum
oxides, nickel-tungsten-niobium oxides, nickel-tungsten-vanadium
oxides, cobalt-tungsten-vanadium oxides, cobalt-tungsten-niobium
oxides, nickel-molybdenum-niobium oxides,
nickel-molybdenum-vanadium oxides,
nickel-molybdenum-tungsten-niobium oxides,
nickel-molybdenum-tungsten-vanadium oxides, and the like, and
combinations thereof.
[0065] Suitable mixed metal oxide compositions can advantageously
exhibit a specific surface area (as measured via the nitrogen BET
method using a Quantachrome Autosorb.TM. apparatus) of about 20
m.sup.2/g to about 500 m.sup.2/g, or about 30 m.sup.2/g to about
300 m.sup.2/g, or about 50 m.sup.2/g to about 150 m.sup.2/g.
[0066] In some aspects, after separating and drying the mixed metal
oxide (slurry) composition, it can be treated, generally by
impregnation with the reaction product and/or the reagents that are
suitable for forming the reaction product.
[0067] In some aspects, the first and/or second organic compound
can comprise at least 10 carbon atoms, for example can comprise
from 10 to 20 carbon atoms or can comprise a primary monoamine
having from 10 to 30 carbon atoms. Additionally or alternately, the
second organic compound can comprise at least 10 carbon atoms, for
example can comprise from 10 to 20 carbon atoms or can comprise
only one carboxylic acid group and can have from 10 to 30 carbon
atoms. Further additionally or alternately, the total number of
carbon atoms comprised among both the first and second organic
compounds can be at least 15 carbon atoms, for example at least 20
carbon atoms, at least 25 carbon atoms, at least 30 carbon atoms,
or at least 35 carbon atoms, such as optionally up to 70 carbon
atoms, or optionally up to 100 carbon atoms.
[0068] Representative examples of organic compounds containing
amine groups can include, but are not limited to, primary and/or
secondary, linear, branched, and/or cyclic amines, such as
triacontanylamine, octacosanylamine, hexacosanylamine,
tetracosanylamine, docosanylamine, erucylamine, eicosanylamine,
octadecylamine, oleylamine, linoleylamine, hexadecylamine,
sapienylamine, palmitoleylamine, tetradecylamine, myristoleylamine,
dodecylamine, decylamine, nonylamine, cyclooctylamine, octylamine,
cycloheptylamine, heptylamine, cyclohexylamine, n-hexylamine,
isopentylamine, n-pentylamine, t-butylamine, n-butylamine,
isopropylamine, n-propylamine, adamantanamine,
adamantanemethylamine, pyrrolidine, piperidine, piperazine,
imidazole, pyrazole, pyrrole, pyrrolidine, pyrroline, indazole,
indole, carbazole, norbornylamine, aniline, pyridylamine,
benzylamine, aminotoluene, alanine, arginine, aspartic acid,
glutamic acid, glutamine, glycine, histidine, isoleucine, leucine,
lysine, phenylalanine, serine, threonine, valine,
1-amino-2-propanol, 2-amino-1-propanol, diaminoeicosane,
diaminooctadecane, diaminohexadecane, diaminotetradecane,
diaminododecane, diaminodecane, 1,2-diaminocyclohexane,
1,3-diaminocyclohexane, 1,4-diaminocyclohexane, ethylenediamine,
ethanolamine, p-phenylenediamine, o-phenylenediamine,
m-phenylenediamine, 1,2-propylenediamine, 1,3-propylenediamine,
1,4-diaminobutane, 1,3diamino-2-propanol, and the like, and
combinations thereof. In an embodiment, the molar ratio of the
Group 6 metal(s) in the composition to the first organic compound
during treatment can be from about 1:1 to about 20:1.
[0069] Additionally or alternately, in some aspects the amine
portion of the first organic compound can be a part of a larger
functional group in that compound, so long as the amine portion
(notably the amine nitrogen and the constituents attached thereto)
retains its operability as a Lewis base. For instance, the first
organic compound can comprise a urea, which functional group
comprises an amine portion attached to the carbonyl portion of an
amide group. In such an instance, the urea can be considered
functionally as an "amine-containing" functional group for the
purposes of the present invention herein, except in situations
where such inclusion is specifically contradicted. Aside from
ureas, other examples of such amine-containing functional groups
that may be suitable for satisfying the at least one amine group in
the first organic compound can generally include, but are not
limited to, hydrazides, sulfonamides, and the like, and
combinations thereof.
[0070] The amine functional group from the first organic compound
can include primary or secondary amines, as mentioned above, but
generally does not include tertiary or quaternary amines, as
tertiary and quaternary amines tend not to be able to form amides.
Furthermore, the first organic compound can contain other
functional groups besides amines, whether or not they are capable
of participating in forming an amide or other condensation reaction
product with one or more of the functional groups from second
organic compound. For instance, the first organic compound can
comprise an amino acid, which possesses an amine functional group
and a carboxylic acid functional group simultaneously. In such an
instance, the amino acid would qualify as only one of the organic
compounds, and not both; thus, in such an instance, either an
additional amine-containing (first) organic compound would need to
be present (in the circumstance where the amino acid would be
considered the second organic compound) or an additional carboxylic
acid-containing (second) organic compound would need to be present
(in the circumstance where the amino acid would be considered the
first organic compound). Aside from carboxylic acids, other
examples of such secondary functional groups in amine-containing
organic compounds can generally include, but are not limited to,
hydroxyls, aldehydes, anhydrides, ethers, esters, imines, imides,
ketones, thiols (mercaptans), thioesters, and the like, and
combinations thereof.
[0071] Representative examples of organic compounds containing
carboxylic acids can include, but are not limited to, primary
and/or secondary, linear, branched, and/or cyclic amines, such as
triacontanoic acid, octacosanoic acid, hexacosanoic acid,
tetracosanoic acid, docosanoic acid, erucic acid, docosahexanoic
acid, eicosanoic acid, eicosapentanoic acid, arachidonic acid,
octadecanoic acid, oleic acid, elaidic acid, stearidonic acid,
linoleic acid, alpha-linolenic acid, hexadecanoic acid, sapienic
acid, palmitoleic acid, tetradecanoic acid, myristoleic acid,
dodecanoic acid, decanoic acid, nonanoic acid, cyclooctanoic acid,
octanoic acid, cycloheptanoic acid, heptanoic acid, cyclohexanoic
acid, hexanoic acid, adamantanecarboxylic acid, norbornaneacetic
acid, benzoic acid, salicylic acid, acetylsalicylic acid, citric
acid, maleic acid, malonic acid, glutaric acid, lactic acid, oxalic
acid, tartaric acid, cinnamic acid, vanillic acid, succinic acid,
adipic acid, phthalic acid, isophthalic acid, terephthalic acid,
ethylenediaminetetracarboxylic acids (such as EDTA), fumaric acid,
alanine, arginine, aspartic acid, glutamic acid, glutamine,
glycine, histidine, isoleucine, leucine, lysine, phenylalanine,
serine, threonine, valine, 1,2-cyclohexanedicarboxylic acid,
1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid,
and the like, and combinations thereof. In an embodiment, the molar
ratio of the Group 6 metal(s) in the composition to the second
organic compound during treatment can be from about 3:1 to about
20:1.
[0072] In some aspects, the second organic compound can optionally
contain other functional groups besides carboxylic acids. For
instance, the second organic compound can comprise an aminoacid,
which possesses a carboxylic acid functional group and an amine
functional group simultaneously. Aside from amines, other examples
of such secondary functional groups in carboxylic acid-containing
organic compounds can generally include, but are not limited to,
hydroxyls, aldehydes, anhydrides, ethers, esters, imines, imides,
ketones, thiols (mercaptans), thioesters, and the like, and
combinations thereof. In some embodiments, the second organic
compound can contain no additional amine or alcohol functional
groups in addition to the carboxylic acid functional group(s).
[0073] Additionally or alternately, the reactive portion of the
second organic compound can be a part of a larger functional group
in that compound and/or can be a derivative of a carboxylic acid
that behaves similarly enough to a carboxylic acid, such that the
reactive portion and/or derivative retains its operability as a
Lewis acid. One example of a carboxylic acid derivative can include
an alkyl carboxylate ester, where the alkyl group does not
substantially hinder (over a reasonable time scale) the Lewis acid
functionality of the carboxylate portion of the functional
group.
[0074] For aspects involving formation of a condensation product
(including aspects involving ex situ formation of an amide), while
there is not a strict limit on the ratio between the first organic
compound and the second organic compound, because the goal of the
addition of the first and second organic compounds is to attain a
condensation reaction product, it may be desirable to have a ratio
of the reactive functional groups within the first and second
organic compounds, respectively, from about 1:4 to about 4:1, for
example from about 1:3 to about 3:1 or from about 1:2 to about 2:1.
In some optional aspects, tt has been observed that catalysts made
with amides from equimolar quantities of the amine and carboxylic
acid reactants compounds show performance improvements in
hydroprocessing certain feeds and for this reason, amides made with
an equimolar ratio are preferred.
[0075] In certain aspects, the organic compound(s)/additive(s)
and/or the reaction product(s) are not located/incorporated within
the crystal lattice of the mixed metal oxide precursor composition,
e.g., instead being located on the surface and/or within the pore
volume of the precursor composition and/or being associated with
(bound to) one or more metals or oxides of metals in a manner that
does not significantly affect the crystalline lattice of the mixed
metal oxide precursor composition, as observed through XRD and/or
other crystallographic spectra. It is noted that, in these certain
embodiments, a sulfided version of the mixed metal oxide precursor
composition can still have its sulfided form affected by the
organic compound(s)/additive(s) and/or the reaction product(s),
even though the oxide lattice is not significantly affected.
[0076] Practically, the treating step (a) above can comprise one
(or more) of three methods: (1) first treating the catalyst
precursor composition with the first organic compound and second
with the second organic compound; (2) first treating the catalyst
precursor composition with the second organic compound and second
with the first organic compound; and/or (3) treating the catalyst
precursor composition simultaneously with the first organic
compound and with the second organic compound.
[0077] In certain advantageous embodiments, the heating step (b)
above can be conducted for a sufficiently long time so as to form
an amide, but not for so long that the amide so formed
substantially decomposes. Additionally or alternately, the heating
step (b) above can be conducted for a sufficiently long time so as
to form additional unsaturation(s), which may result from at least
partial decomposition (e.g., oxidative and/or non-oxidative
dehydrogenation and/or aromatization) of some
(typically-unfunctionalized organic) portions of the organic
compounds, but generally not for so long that the at least partial
decomposition (i) substantially decomposes any condensation
product, such as amide, and/or (ii) volatilizes more than 50% by
weight of the combined first and second organic compounds.
[0078] It is contemplated that the specific lower and upper
temperature limits based on the above considerations can be highly
dependent upon a variety of factors that can include, but are not
limited to, the atmosphere under which the heating is conducted,
the chemical and/or physical properties of the first organic
compound, the second organic compound, the reaction product, and/or
any reaction byproduct, or a combination thereof. In one
embodiment, the heating temperature can be at least about
120.degree. C., for example about 150.degree. C. or more, or about
210.degree. C. or more, or about 250.degree. C. or more.
Additionally or alternately, the heating temperature can be not
greater than about 400.degree. C., for example not greater than
about 350.degree. C., not greater than about 300.degree. C., not
greater than about 250.degree. C., or not greater than about
200.degree. C.
[0079] In one embodiment, the heating can be conducted in a low- or
non-oxidizing atmosphere (and conveniently in an inert atmosphere,
such as nitrogen). In an alternate embodiment, the heating can be
conducted in a moderately- or highly-oxidizing environment. In
another alternate embodiment, the heating can include a multi-step
process in which one or more heating steps can be conducted in the
low- or non-oxidizing atmosphere, in which one or more heating
steps can be conducted in the moderately- or highly-oxidizing
environment, or both. Of course, the period of time for the heating
in the environment can be tailored to the first or second organic
compound, but can typically extend from about 5 minutes to about
168 hours, for example from about 10 minutes to about 96 hours,
from about 20 minutes to about 48 hours, from about 30 minutes to
about 24 hours, or from about 1 hour to about 4 hours.
[0080] Additionally or alternately, in aspects where an ex situ
formed amide is used, the amide can be formed prior to impregnation
into the metal oxide component of the catalyst precursor by
reaction of the amine component and the carboxylic acid component.
Reaction typically takes place readily at mildly elevated
temperatures up to about 200.degree. C. with liberation of water as
a by-product of the reaction at temperatures above 100.degree. C.
and usually above 150.degree. C. The reactants can usually be
heated together to form a melt in which the reaction takes place
and the melt impregnated directly into the metal oxide component
which is preferably pre-heated to the same temperature as the melt
in order to assist penetration into the structure of the metal
oxide component. The reaction can also be carried out in the
presence of a solvent if desired and the resulting solution used
for the impregnation step. In certain embodiments, the amide and
its heat treated derivative may not be located/incorporated within
the crystal lattice of the mixed metal oxide precursor, e.g., may
instead be located on the surface and/or within the pore volume of
the precursor and/or be associated with (bound to) one or more
metals or oxides of metals in a manner that does not significantly
affect the crystalline lattice of the mixed metal oxide precursor
composition, as observed through XRD and/or other crystallographic
spectra. A sulfided version of the mixed metal oxide precursor
composition can still have its sulfided form affected by the
organic compound(s)/additive(s) and/or the reaction product(s),
even though the oxide lattice is not significantly affected.
[0081] In an embodiment, the organically treated catalyst precursor
composition and/or the catalyst precursor composition containing
the reaction product can contain from about 4 wt % to about 20 wt
%, for example from about 5 wt % to about 15 wt %, carbon resulting
from the first and second organic compounds and/or from the
condensation product, as applicable, based on the total weight of
the relevant composition.
[0082] Additionally or alternately, as a result of the heating
step, the reaction product from the organically treated catalyst
precursor can exhibit a content of unsaturated carbon atoms (which
includes aromatic carbon atoms), as measured according to peak area
comparisons using .sup.13C NMR techniques, of at least 29%, for
example at least about 30%, at least about 31%, at least about 32%,
or at least about 33%. Further additionally or alternately, the
reaction product from the organically treated catalyst precursor
can optionally exhibit a content of unsaturated carbon atoms (which
includes aromatic carbon atoms), as measured according to peak area
comparisons using .sup.13C NMR techniques, of up to about 70%, for
example up to about 65%, up to about 60%, up to about 55%, up to
about 50%, up to about 45%, up to about 40%, or up to about 35%.
Still further additionally or alternately, as a result of the
heating step, the reaction product from the organically treated
catalyst precursor can exhibit an increase in content of
unsaturated carbon atoms (which includes aromatic carbon atoms), as
measured according to peak area comparisons using .sup.13C NMR
techniques, of at least about 17%, for example at least about 18%,
at least about 19%, at least about 20%, or at least about 21%
(e.g., in an embodiment where the first organic compound is
oleylamine and the second organic compound is oleic acid, such that
the combined unsaturation level of the unreacted compounds is about
11.1% of carbon atoms, a .about.17% increase in unsaturated carbons
upon heating corresponds to about 28.1% content of unsaturated
carbon atoms in the reaction product). Yet further additionally or
alternately, the reaction product from the organically treated
catalyst precursor can optionally exhibit an increase in content of
unsaturated carbon atoms (which includes aromatic carbon atoms), as
measured according to peak area comparisons using .sup.13C NMR
techniques, of up to about 60%, for example up to about 55%, up to
about 50%, up to about 45%, up to about 40%, up to about 35%, up to
about 30%, or up to about 25%.
[0083] Again further additionally or alternately, as a result of
the heating step, the reaction product from the organically treated
catalyst precursor can exhibit a ratio of unsaturated carbon atoms
to aromatic carbon atoms, as measured according to peak area ratios
using infrared spectroscopic techniques of a deconvoluted peak
centered from about 1700 cm.sup.-1 to about 1730 cm.sup.-1 (e.g.,
at about 1715 cm.sup.-1), compared to a deconvoluted peak centered
from about 1380 cm.sup.-1 to about 1450 cm.sup.-1 (e.g., from about
1395 cm.sup.-1 to about 1415 cm.sup.-1), of at least 0.9, for
example at least 1.0, at least 1.1, at least 1.2, at least 1.3, at
least 1.4, at least 1.5, at least 1.7, at least 2.0, at least 2.2,
at least 2.5, at least 2.7, or at least 3.0. Again still further
additionally or alternately, the reaction product from the
organically treated catalyst precursor can exhibit a ratio of
unsaturated carbon atoms to aromatic carbon atoms, as measured
according to peak area ratios using infrared spectroscopic
techniques of a deconvoluted peak centered from about 1700
cm.sup.-1 to about 1730 cm.sup.-1 (e.g., at about 1715 cm.sup.-1),
compared to a deconvoluted peak centered from about 1380 cm.sup.-1
to about 1450 cm.sup.-1 (e.g., from about 1395 cm.sup.-1 to about
1415 cm.sup.-1), of up to 15, for example up to 10, up to 8.0, up
to 7.0, up to 6.0, up to 5.0, up to 4.5, up to 4.0, up to 3.5, or
up to 3.0.
[0084] A (sulfided) hydroprocessing catalyst composition can then
be produced by sulfiding the catalyst precursor composition
containing the reaction product. Sulfiding is generally carried out
by contacting the catalyst precursor composition containing the
reaction product with a sulfur-containing compound (e.g., elemental
sulfur, hydrogen sulfide, polysulfides, or the like, or a
combination thereof, which may originate from a fossil/mineral oil
stream, from a biocomponent-based oil stream, from a combination
thereof, or from a sulfur-containing stream separate from the
aforementioned oil stream(s)) at a temperature and for a time
sufficient to substantially sulfide the composition and/or
sufficient to render the sulfided composition active as a
hydroprocessing catalyst. For instance, the sulfidation can be
carried out at a temperature from about 300.degree. C. to about
400.degree. C., e.g., from about 310.degree. C. to about
350.degree. C., for a period of time from about 30 minutes to about
96 hours, e.g., from about 1 hour to about 48 hours or from about 4
hours to about 24 hours. The sulfiding can generally be conducted
before or after combining the metal (oxide) containing composition
with a binder, if desired, and before or after forming the
composition into a shaped catalyst. The sulfiding can additionally
or alternately be conducted in situ in a hydroprocessing reactor.
Obviously, to the extent that a reaction product of the first or
second organic compounds contains additional unsaturations formed
in situ, it would generally be desirable for the sulfidation
(and/or any catalyst treatment after the organic treatment) to
significantly maintain the in situ formed additional unsaturations
of said reaction product.
[0085] The sulfided catalyst composition can exhibit a layered
structure comprising a plurality of stacked YS.sub.2 layers, where
Y is the Group 6 metal(s), such that the average number of stacks
(typically for bulk organically treated catalysts) can be from
about 1.5 to about 3.5, for example from about 1.5 to about 3.0,
from about 2.0 to about 3.3, from about 2.0 to about 3.0, or from
about 2.1 to about 2.8. For instance, the treatment of the metal
(oxide) containing precursor composition according to the invention
can afford a decrease in the average number of stacks of the
treated precursor of at least about 0.8, for example at least about
1.0, at least about 1.2, at least about 1.3, at least about 1.4, or
at least about 1.5, as compared to an untreated metal (oxide)
containing precursor composition. As such, the number of stacks can
be considerably less than that obtained with an equivalent sulfided
mixed metal (oxide) containing precursor composition produced
without the first or second organic compound treatment. The
reduction in the average number of stacks can be evidenced, e.g.,
via X-ray diffraction spectra of relevant sulfided compositions, in
which the (002) peak appears significantly broader (as determined
by the same width at the half-height of the peak) than the
corresponding peak in the spectrum of the sulfided mixed metal
(oxide) containing precursor composition produced without the
organic treatment (and/or, in certain cases, with only a single
organic compound treatment using an organic compound having less
than 10 carbon atoms) according to the present invention.
Additionally or alternately to X-ray diffraction, transmission
electron microscopy (TEM) can be used to obtain micrographs of
relevant sulfided compositions, including multiple microcrystals,
within which micrograph images the multiple microcrystals can be
visually analyzed for the number of stacks in each, which can then
be averaged over the micrograph visual field to obtain an average
number of stacks that can evidence a reduction in average number of
stacks compared to a sulfided mixed metal (oxide) containing
precursor composition produced without the organic treatment
(and/or, in certain cases, with only a single organic compound
treatment) according to the present invention.
Multimetallic Catalyst and Forming Multimetallic Catalyst from
Reactants at Least Partially in the Solid State
[0086] In various aspects, another option for a bulk multimetallic
catalyst is to use a bulk multimetallic catalyst comprised of at
least one Group VIII non-noble metal and at least two Group VIB
metals and wherein the ratio of Group VIB metal to Group VIII
non-noble metal is from about 10:1 to about 1:10. It is preferred
that the catalyst be a bulk trimetallic catalyst comprised of one
Group VIII non-noble metal, preferably Ni or Co and the two Group
VIB metals Mo and W. It is preferred that the ratio of Mo to W be
about 9:1 to about 1:9.
[0087] The preferred bulk trimetallic catalyst compositions used in
the practice of the present invention is represented by the
formula:
(X).sub.b(Mo).sub.c(W).sub.dO.sub.x
[0088] wherein X is one or more Group VIII non-noble metal, the
molar ratio of b:(c+d) is 0.5/1 to 3/1, preferably 0.75/1 to 1.5/1,
more preferably 0.75/1 to 1.25/1; The molar ratio of c:d is
preferably >0.01/1, more preferably >0.1/1, still more
preferably 1/10 to 10/1, still more preferably 1/3 to 3/1, most
preferably substantially equimolar amounts of Mo and W, e.g., 2/3
to 3/2; and z=[2b+6(c+d)]/2.
[0089] The essentially amorphous material has a unique X-ray
diffraction pattern showing crystalline peaks at d=2.53 Angstroms
and d=1.70 Angstroms.
[0090] The mixed metal oxide is readily produced by the
decomposition of a precursor having the formula:
(NH.sub.4).sub.a(X).sub.b(Mo).sub.c(W).sub.dO.sub.x
[0091] wherein the molar ratio of a:b is .ltoreq.1.0/1, preferably
0-1; and b, c, and d, are as defined above, and z=[a+2b+6(c+d)]/2.
The precursor has similar peaks at d=2.53 and 1.70 Angstroms.
[0092] Decomposition of the precursor may be effected at elevated
temperatures, e.g., temperatures of at least about 300.degree. C.,
preferably about 300-450.degree. C., in a suitable atmosphere,
e.g., inerts such as nitrogen, argon, or steam, until decomposition
is substantially complete, i.e., the ammonium is substantially
completely driven off. Substantially complete decomposition can be
readily established by thermogravimetric analysis (TGA), i.e.,
flattening of the weight change curve.
[0093] The catalyst compositions used in the practice of the
present invention can be prepared by any suitable means. One such
means is a method wherein not all of the metals are in solution.
Generally, the contacting of the metal components in the presence
of the protic liquid comprises mixing the metal component and
subsequently reacting the resulting mixture. It is essential to the
solid route that at least one metal components is added at least
partly in the solid state during the mixing step and that the metal
of at least one of the metal components which have been added at
least partly in the solid state, remains at least partly in the
solid state during the mixing and reaction step. "Metal" in this
context does not mean the metal in its metallic form but present in
a metal compound, such as the metal component as initially applied
or as present in the bulk catalyst composition.
[0094] Generally, during the mixing step either at least one metal
component is added at least partly in the solid state and at least
one metal component is added in the solute state, or all metal
components are added at least partly in the solid state, wherein at
least one of the metals of the metal components which are added at
least partly in the solid state remains at least partly in the
solid state during the entire process of the solid route. That a
metal component is added "in the solute state" means that the whole
amount of this metal component is added as a solution of this metal
component in the protic liquid. That a metal component is added "at
least partly in the solid state" means that at least part of the
metal component is added as solid metal component and, optionally,
another part of the metal component is added as a solution of this
metal component in the protic liquid. A typical example is a
suspension of a metal component in a protic liquid in which the
metal is at least partly present as a solid, and optionally partly
dissolved in the protic liquid.
[0095] To obtain a bulk catalyst composition with high catalytic
activity, it is therefore preferred that the metal components,
which are at least partly in the solid state during contacting, are
porous metal components. It is desired that the total pore volume
and pore size distribution of these metal components is
approximately the same as those of conventional hydrotreating
catalysts. Conventional hydrotreating catalysts generally have a
pore volume of 0.05-5 ml/g, preferably of 0.1-4 ml/g, more
preferably of 0.1-3 ml/g and most preferably of 0.1-2 ml/g
determined by nitrogen adsorption. Pores with a diameter smaller
than 1 nm are generally not present in conventional hydrotreating
catalysts. Further, conventional hydrotreating catalysts have
generally a surface area of at least 10 m.sup.2/g and more
preferably of at least 50 m.sup.2/g and most preferably of at least
100 m.sup.2/g, determined via the B.E.T. method. For instance,
nickel carbonate can be chosen which has a total pore volume of
0.19-0.39 ml/g and preferably of 0.24-0.35 ml/g determined by
nitrogen adsorption and a surface area of 150-400 m.sup.2/g and
more preferably of 200-370 m.sup.2/g determined by the B.E.T.
method. Furthermore these metal components should have a median
particle diameter of at least 50 nm, more preferably at least 100
nm, and preferably not more than 5000 .mu.m and more preferably not
more than 3000 .mu.m. Even more preferably, the median particle
diameter lies in the range of 0.1-50 .mu.m and most preferably in
the range of 0.5-50 .mu.m. For instance, by choosing a metal
component which is added at least partly in the solid state and
which has a large median particle diameter, the other metal
components will only react with the outer layer of the large metal
component particle. In this case, so-called "core-shell" structured
bulk catalyst particles are obtained.
[0096] An appropriate morphology and texture of the metal component
can either be achieved by applying suitable preformed metal
components or by preparing these metal components by the
above-described precipitation under such conditions that a suitable
morphology and texture is obtained. A proper selection of
appropriate precipitation conditions can be made by routine
experimentation.
[0097] As has been set out above, to retain the morphology and
texture of the metal components which are added at least partly in
the solid state, it is essential that the metal of the metal
component at least partly remains in the solid state during the
whole process of this solid route. It is noted again that it is
essential that in no case should the amount of solid metals during
the process of the solid route becomes zero. The presence of solid
metal comprising particles can easily be detected by visual
inspection at least if the diameter of the solid particles in which
the metals are comprised is larger than the wavelength of visible
light. Of course, methods such as quasi-elastic light scattering
(QELS) or near forward scattering which are known to the skilled
person can also be used to ensure that in no point in time of the
process of the solid route, all metals are in the solute state.
[0098] The protic liquid to be applied in the solid or solution
route of this invention for preparing catalyst can be any protic
liquid. Examples include water, carboxylic acids, and alcohols such
as methanol or ethanol. Preferably, a liquid comprising water such
as mixtures of an alcohol and water and more preferably water is
used as protic liquid in this solid route. Also different protic
liquids can be applied simultaneously in the solid route. For
instance, it is possible to add a suspension of a metal component
in ethanol to an aqueous solution of another metal component.
[0099] The Group VIB metal generally comprises chromium,
molybdenum, tungsten, or mixtures thereof. Suitable Group VIII
non-noble metals are, e.g., iron, cobalt, nickel, or mixtures
thereof. Preferably, a combination of metal components comprising
nickel, molybdenum and tungsten or nickel, cobalt, molybdenum and
tungsten is applied in the process of the solid route. If the
protic liquid is water, suitable nickel components which are at
least partly in the solid state during contacting comprise
water-insoluble nickel components such as nickel carbonate, nickel
hydroxide, nickel phosphate, nickel phosphite, nickel formate,
nickel sulfide, nickel molybdate, nickel tungstate, nickel oxide,
nickel alloys such as nickel-molybdenum alloys, Raney nickel, or
mixtures thereof. Suitable molybdenum components, which are at
least partly in the solid state during contacting, comprise
water-insoluble molybdenum components such as molybdenum (di- and
tri) oxide, molybdenum carbide, molybdenum nitride, aluminum
molybdate, molybdic acid (e.g. H.sub.2MoO.sub.4), molybdenum
sulfide, or mixtures thereof. Finally, suitable tungsten components
which are at least partly in the solid state during contacting
comprise tungsten di- and trioxide, tungsten sulfide (WS.sub.2 and
WS.sub.3), tungsten carbide, tungstic acid (e.g.
H.sub.2WO.sub.4--H.sub.2O, H.sub.2W.sub.2O.sub.3--H.sub.2O),
tungsten nitride, aluminum tungstate (also meta-, or polytungstate)
or mixtures thereof. These components are generally commercially
available or can be prepared by, e.g., precipitation. e.g., nickel
carbonate can be prepared from a nickel chloride, sulfate, or
nitrate solution by adding an appropriate amount of sodium
carbonate. It is generally known to the skilled person to choose
the precipitation conditions in such a way as to obtain the desired
morphology and texture.
[0100] In general, metal components, which mainly contain C, O,
and/or H besides the metal, are preferred because they are less
detrimental to the environment. Nickel carbonate is a preferred
metal component to be added at least partly in the solid state
because when nickel carbonate is applied, CO.sub.2 evolves and
positively influences the pH of the reaction mixture. Further, due
to the transformation of carbonate into CO.sub.2, the carbonate
does not end up in the wastewater.
[0101] Preferred nickel components which are added in the solute
state are water-soluble nickel components, e.g. nickel nitrate,
nickel sulfate, nickel acetate, nickel chloride, or mixtures
thereof. Preferred molybdenum and tungsten components which are
added in the solute state are water-soluble molybdenum and tungsten
components such as alkali metal or ammonium molybdate (also
peroxo-, di-, tri-, tetra-, hepta-, octa-, or tetradecamolybdate),
Mo--P heteropolyanion compounds, Wo-Si heteropolyanion compounds,
W--P heteropolyanion compounds, W--Si heteropolyanion compounds,
Ni--Mo--W heteropolyanion compounds, Co--Mo--W heteropolyanion
compounds, alkali metal or ammonium tungstates (also meta-, para-,
hexa-, or polytungstate), or mixtures thereof.
[0102] Preferred combinations of metal components are nickel
carbonate, tungstic acid and molybdenum oxide. Another preferred
combination is nickel carbonate, ammonium dimolybdate and ammonium
metatungstate. It is within the scope of the skilled person to
select further suitable combinations of metal components. It must
be noted that nickel carbonate always comprises a certain amount of
hydroxy-groups. It is preferred that the amount of hydroxy-groups
present in the nickel carbonate be high.
[0103] An alternative method of preparing the catalysts used in the
practice of the present invention is to prepare the bulk catalyst
composition by a process comprising reacting in a reaction mixture
a Group VIII non-noble metal component in solution and a Group VIB
metal component in solution to obtain a precipitate. As in the case
of the solid route, preferably, one Group VIII non-noble metal
component is reacted with two Group VIB metal components. The molar
ratio of Group VIB metals to Group VIII non-noble metals applied in
the process of the solution route is preferably the same as
described for the solid route. Suitable Group VIB and Group VIII
non-noble metal components are, e.g. those water-soluble nickel,
molybdenum and tungsten components described above for the solid
route. Further Group VIII non-noble metal components are, e.g.,
cobalt or iron components. Further Group VIB metal components are,
e.g. chromium components. The metal components can be added to the
reaction mixture in solution, suspension or as such. If soluble
salts are added as such, they will dissolve in the reaction mixture
and subsequently be precipitated. Suitable Group VIB metal salts
which are soluble in water are ammonium salts such as ammonium
dimolybdate, ammonium tri-, tetra-, hepta-, octa-, and
tetradeca-molybdate, ammonium para-, meta-, hexa-, and
polytungstate, alkali metal salts, silicic acid salts of Group VIB
metals such as molybdic silicic acid, molybdic silicic tungstic
acid, tungstic acid, metatungstic acid, pertungstic acid,
heteropolyanion compounds of Mo--P, Mo--Si, W--P, and W--Si. It is
also possible to add Group VIB metal-containing compounds which are
not in solution at the time of addition, but where solution is
effected in the reaction mixture. Examples of these compounds are
metal compounds which contain so much crystal water that upon
temperature increase they will dissolve in their own metal water.
Further, non-soluble metal salts may be added in suspension or as
such, and solution is effected in the reaction mixture. Suitable
non-soluble metals salts are heteropolyanion compounds of Co--Mo--W
(moderately soluble in cold water), heteropolyanion compounds of
Ni--Mo--W (moderately soluble in cold water).
[0104] The reaction mixture is reacted to obtain a precipitate.
Precipitation is effected by adding a Group VIII non-noble metal
salt solution at a temperature and pH at which the Group VIII
non-noble metal and the Group VIB metal precipitate, adding a
compound which complexes the metals and releases the metals for
precipitation upon temperature increase or pH change or adding a
Group VIB metal salt solution at a temperature and pH at which the
Group VIII non-noble metal and Group VIB metal precipitate,
changing the temperature, changing the pH, or lowering the amount
of the solvent. The precipitate obtained with this process appears
to have high catalytic activity. In contrast to the conventional
hydroprocessing catalysts, which usually comprise a carrier
impregnated with Group VIII non-noble metals and Group VIB metals,
said precipitate can be used without a support. Unsupported
catalyst compositions are usually referred to as bulk catalysts.
Changing the pH can be done by adding base or acid to the reaction
mixture, or adding compounds, which decompose upon temperature,
increase into hydroxide ions or H+ ions that respectively increase
or decrease the pH. Examples of compounds that decompose upon
temperature increase and thereby Increase or decrease the pH are
urea, nitrites, ammonium cyanate, ammonium hydroxide, and ammonium
carbonate.
[0105] In an illustrative process according to the solution route,
solutions of ammonium salts of a Group VIB metal are made and a
solution of a Group VIII non-noble metal nitrate is made. Both
solutions are heated to a temperature of approximately 90.degree.
C. Ammonium hydroxide is added to the Group VIB metal solution. The
Group VIII non-noble metal solution is added to the Group VIB metal
solution and direct precipitation of the Group VIB and Group VIII
non-noble metal components occurs. This process can also be
conducted at lower temperature and/or decreased pressure or higher
temperature and/or increased pressure.
[0106] In another illustrative process according to the solution
route, a Group VIB metal salt, a Group VIII metal salt, and
ammonium hydroxide are mixed in solution together and heated so
that ammonia is driven off and the pH is lowered to a pH at which
precipitation occurs. For instance when nickel, molybdenum, and
tungsten components are applied, precipitation typically occurs at
a pH below 7.
[0107] The bulk catalyst composition can generally be directly
shaped into hydroprocessing particles. If the amount of liquid of
the bulk catalyst composition is so high that it cannot be directly
subjected to a shaping step, a solid liquid separation can be
performed before shaping. Optionally the bulk catalyst composition,
either as such or after solid liquid separation, can be calcined
before shaping.
[0108] The median diameter of the bulk catalyst particles is at
least 50 nm, more preferably at least 100 nm, and preferably not
more than 5000 .mu.m and more preferably not more than 3000 .mu.m.
Even more preferably, the median particle diameter lies in the
range of 0.1-50 .mu.m and most preferably in the range of 0.5-50
.mu.m.
[0109] If a binder material is used in the preparation of the
catalyst composition it can be any material that is conventionally
applied as a binder in hydroprocessing catalysts. Examples include
silica, silica-alumina, such as conventional silica-alumina,
silica-coated alumina and alumina-coated silica, alumina such as
(pseudo)boehmite, or gibbsite, titania, zirconia, cationic clays or
anionic clays such as saponite, bentonite, kaoline, sepiolite or
hydrotalcite, or mixtures thereof. Preferred binders are silica,
silica-alumina, alumina, titanic, zirconia, or mixtures thereof.
These binders may be applied as such or after peptization. It is
also possible to apply precursors of these binders that, during the
process of the invention are converted into any of the
above-described binders. Suitable precursors are, e g., alkali
metal aluminates (to obtain an alumina binder), water glass (to
obtain a silica binder), a mixture of alkali metal aluminates and
water glass (to obtain a silica alumina binder), a mixture of
sources of a di-, tri-, and/or tetravalent metal such as a mixture
of water-soluble salts of magnesium, aluminum and/or silicon (to
prepare a cationic clay and/or anionic clay), chlorohydrol,
aluminum sulfate, or mixtures thereof.
[0110] If desired, the binder material may be composited with a
Group VIB metal and/or a Group VIII non-noble metal, prior to being
composited with the bulk catalyst composition and/or prior to being
added during the preparation thereof. Compositing the binder
material with any of these metals may be carried out by
impregnation of the solid binder with these materials. The person
skilled in the art knows suitable impregnation techniques. If the
binder is peptized, it is also possible to carry out the
peptization in the presence of Group VIB and/or Group VIII
non-noble metal components.
[0111] Generally, the binder material to be added in the process of
the invention has less catalytic activity than the bulk catalyst
composition or no catalytic activity at all. Consequently, by
adding a binder material, the activity of the bulk catalyst
composition may be reduced. Therefore, the amount of binder
material to be added in the process of the invention generally
depends on the desired activity of the final catalyst composition.
Binder amounts from 0-95 wt. % of the total composition can be
suitable, depending on the envisaged catalytic application.
However, to take advantage of the resulting unusual high activity
of the composition of the present invention, binder amounts to be
added are generally in the range of 0.5-75 wt. % of the total
composition.
[0112] The catalyst composition can be directly shaped. Shaping
comprises extrusion, pelletizing, beading, and/or spray drying. It
must be noted that if the catalyst composition is to be applied in
slurry type reactors, fluidized beds, moving beds, expanded beds,
or ebullating beds, spray drying or beading is generally applied
for fixed bed applications, generally, the catalyst composition is
extruded, pelletized and/or beaded. In the latter case, prior to or
during the shaping step, any additives that are conventionally used
to facilitate shaping can be added. These additives may comprise
aluminum stearate, surfactants, graphite or mixtures thereof. These
additives can be added at any stage prior to the shaping step.
Further, when alumina is used as a binder, it may be desirable to
add acids prior to the shaping step such as nitric acid to increase
the mechanical strength of the extrudates.
[0113] It is preferred that a binder material is added prior to the
shaping step. Further, it is preferred that the shaping step is
carried out in the presence of a liquid, such as water. Preferably,
the amount of liquid in the extrusion mixture, expressed as LOI is
in the range of 20-80%.
[0114] The resulting shaped catalyst composition can, after an
optional drying step, be optionally calcined. Calcination however
is not essential to the process of the invention. If a calcination
is carried out in the process of the invention, it can be done at a
temperature of, e.g., from 100-600.degree. C. and preferably 350 to
500.degree. C. for a time varying from 0.5 to 48 hours. The drying
of the shaped particles is generally carried out at temperatures
above 100.degree. C.
[0115] In a preferred embodiment of the invention, the catalyst
composition is subjected to spray drying (flash) drying, milling,
kneading, or combinations thereof prior to shaping. These
additional process steps can be conducted either before or after a
binder is added, after solid-liquid separation, before or after
calcination and subsequent to re-wetting. It is believed that by
applying any of the above-described techniques of spray drying,
(flash) drying, milling, kneading, or combinations thereof, the
degree of mixing between the bulk catalyst composition and the
binder material is improved. This applies to both cases where the
binder material is added before or after the application of any of
the above-described methods. However, it is generally preferred to
add the binder material prior to spray drying and/or any
alternative technique. If the binder is added subsequent to spray
drying and/or any alternative technique, the resulting composition
is preferably thoroughly mixed by any conventional technique prior
to shaping. An advantage of, e.g., spray drying is that no
wastewater streams are obtained when this technique is applied.
[0116] The processes of the present invention for preparing the
bulk catalyst compositions may further comprise a sulfidation step.
Sulfidation is generally carried out by contacting the catalyst
composition or precursors thereof with a sulfur containing compound
such as elementary sulfur, hydrogen sulfide or polysulfides. The
sulfidation can generally be carried out subsequently to the
preparation of the bulk catalyst composition but prior to the
addition of a binder material, and/or subsequently to the addition
of the binder material but prior to subjecting the catalyst
composition to spray drying and/or any alternative method, and/or
subsequently to subjecting the composition to spray drying and/or
any alternative method but prior to shaping, and/or subsequently to
shaping the catalyst composition. It is preferred that the
sulfidation is not carried out prior to any process step that
reverts the obtained metal sulfides into their oxides. Such process
steps are, e.g., calcination or spray drying or any other high
temperature treatment in the presence of oxygen. Consequently, if
the catalyst composition is subjected to spray drying and/or any
alternative technique, the sulfidation should be carried out
subsequent to the application of any of these methods.
[0117] Additionally to, or instead of, a sulfidation step, the bulk
catalyst composition may be prepared from at least one metal
sulfide. If, e.g. the solid route is applied in step (i), the bulk
catalyst component can be prepared form nickel sulfide and/or
molybdenum sulfide and/or tungsten sulfide.
Additional Components for Bulk Catalysts
[0118] The sulfided catalyst composition described above can be
used as a hydroprocessing catalyst, either alone or in combination
with a binder. If the sulfided catalyst composition is a bulk
catalyst, then only a relatively small amount of binder may be
added. However, if the sulfided catalyst composition is a
heterogeneous/supported catalyst, then usually the binder is a
significant portion of the catalyst composition, e.g., at least
about 40 wt %, at least about 50 wt %, at least about 60 wt %, or
at least about 70 wt %; additionally or alternately for
heterogeneous/supported catalysts, the binder can comprise up to
about 95 wt % of the catalyst composition, e.g., up to about 90 wt
%, up to about 85 wt %, up to about 80 wt %, up to about 75 wt %,
or up to about 70 wt %. Non-limiting examples of suitable binder
materials can include, but are not limited to, silica,
silica-alumina (e.g., conventional silica-alumina, silica-coated
alumina, alumina-coated silica, or the like, or a combination
thereof), alumina (e.g., boehmite, pseudo-boehmite, gibbsite, or
the like, or a combination thereof), titania, zirconia, cationic
clays or anionic clays (e.g., saponite, bentonite, kaoline,
sepiolite, hydrotalcite, or the like, or a combination thereof),
and mixtures thereof. In some preferred embodiments, the binder can
include silica, silica-alumina, alumina, titania, zirconia, and
mixtures thereof. These binders may be applied as such or after
peptization. It may also be possible to apply precursors of these
binders that, during precursor synthesis, can be converted into any
of the above-described binders. Suitable precursors can include,
e.g., alkali metal aluminates (alumina binder), water glass (silica
binder), a mixture of alkali metal aluminates and water glass
(silica-alumina binder), a mixture of sources of a di-, tri-,
and/or tetravalent metal, such as a mixture of water-soluble salts
of magnesium, aluminum, and/or silicon (cationic clay and/or
anionic clay), chlorohydrol, aluminum sulfate, or mixtures
thereof.
[0119] Generally, the binder material to be used can have lower
catalytic activity than the remainder of the catalyst composition,
or can have substantially no catalytic activity at all (less than
about 5%, based on the catalytic activity of the bulk catalyst
composition being about 100%). Consequently, by using a binder
material, the activity of the catalyst composition may be reduced.
Therefore, the amount of binder material to be used, at least in
bulk catalysts, can generally depend on the desired activity of the
final catalyst composition. Binder amounts up to about 25 wt % of
the total composition can be suitable (when present, from above 0
wt % to about 25 wt %), depending on the envisaged catalytic
application. However, to take advantage of the resulting unusual
high activity of bulk catalyst compositions according to the
invention, binder amounts, when added, can generally be from about
0.5 wt % to about 20 wt % of the total catalyst composition.
[0120] If desired in bulk catalyst cases, the binder material can
be composited with a source of a Group 6 metal and/or a source of a
non-noble Group 8-10 metal, prior to being composited with the bulk
catalyst composition and/or prior to being added during the
preparation thereof. Compositing the binder material with any of
these metals may be carried out by any known means, e.g.,
impregnation of the (solid) binder material with these metal(s)
sources.
[0121] A cracking component may also be added during catalyst
preparation. When used, the cracking component can represent from
about 0.5 wt % to about 30 wt %, based on the total weight of the
catalyst composition. The cracking component may serve, for
example, as an isomerization enhancer. Conventional cracking
components can be used, e.g., a cationic clay, an anionic clay, a
zeolite (such as ZSM-5, zeolite Y, ultra-stable zeolite Y, zeolite
X, an AlPO, a SAPO, or the like, or a combination thereof),
amorphous cracking components (such as silica-alumina or the like),
or a combination thereof. It is to be understood that some
materials may act as a binder and a cracking component at the same
time. For instance, silica-alumina may simultaneously have both a
cracking and a binding function.
[0122] If desired, the cracking component may be composited with a
Group 6 metal and/or a Group 8-10 non-noble metal, prior to being
composited with the catalyst composition and/or prior to being
added during the preparation thereof. Compositing the cracking
component with any of these metals may be carried out by any known
means, e.g., impregnation of the cracking component with these
metal(s) sources. When both a cracking component and a binder
material are used and when compositing of additional metal
components is desired on both, the compositing may be done on each
component separately or may be accomplished by combining the
components and doing a single compositing step.
[0123] The selection of particular cracking components, if any, can
depend on the intended catalytic application of the final catalyst
composition. For instance, a zeolite can be added if the resulting
composition is to be applied in hydrocracking or fluid catalytic
cracking. Other cracking components, such as silica-alumina or
cationic clays, can be added if the final catalyst composition is
to be used in hydrotreating applications. The amount of added
cracking material can depend on the desired activity of the final
composition and the intended application, and thus, when present,
may vary from above 0 wt % to about 80 wt %, based on the total
weight of the catalyst composition. In a preferred embodiment, the
combination of cracking component and binder material can comprise
less than 50 wt % of the catalyst composition, for example, less
than about 40 wt %, less than about 30 wt %, less than about 20 wt
%, less than about 15 wt %, or less than about 10 wt %.
[0124] If desired, further materials can be added, in addition to
the metal components already added, such as any material that would
be added during conventional hydroprocessing catalyst preparation.
Suitable examples of such further materials can include, but are
not limited to, phosphorus compounds, boron compounds,
fluorine-containing compounds, sources of additional transition
metals, sources of rare earth metals, fillers, or mixtures
thereof.
Hydrotreating and Hydrocracking
[0125] After deasphalting, the deasphalted oil (and any additional
fractions combined with the deasphalted oil) can undergo further
processing to form lubricant base stocks. This can include
hydrotreatment and/or hydrocracking to remove heteroatoms to
desired levels, reduce Conradson Carbon content, and/or provide
viscosity index (VI) uplift. Depending on the aspect, a deasphalted
oil can be hydroprocessed by hydrotreating, hydrocracking, or
hydrotreating and hydrocracking. Optionally, one or more catalyst
beds and/or stages of demetallization catalyst can be included
prior to the initial bed of hydrotreating and/or hydrocracking
catalyst. Optionally, the hydroprocessing can further include
exposing the deasphalted oil to a base metal aromatic saturation
catalyst. It is noted that a base metal aromatic saturation
catalyst can sometimes be similar to a lower activity hydrotreating
catalyst.
[0126] The deasphalted oil can be hydrotreated and/or hydrocracked
with little or no solvent extraction being performed prior to
and/or after the deasphalting. As a result, the deasphalted oil
feed for hydrotreatment and/or hydrocracking can have a substantial
aromatics content. In various aspects, the aromatics content of the
deasphalted oil feed can be at least 50 wt %, or at least 55 wt %,
or at least 60 wt %, or at least 65 wt %, or at least 70 wt %, or
at least 75 wt %, such as up to 90 wt % or more. Additionally or
alternately, the saturates content of the deasphalted oil feed can
be 50 wt % or less, or 45 wt % or less, or 40 wt % or less, or 35
wt % or less, or 30 wt % or less, or 25 wt % or less, such as down
to 10 wt % or less. In this discussion and the claims below, the
aromatics content and/or the saturates content of a fraction can be
determined based on ASTM D7419.
[0127] The reaction conditions during demetallization and/or
hydrotreatment and/or hydrocracking of the deasphalted oil (and
optional vacuum gas oil co-feed) can be selected to generate a
desired level of conversion of a feed. Any convenient type of
reactor, such as fixed bed (for example trickle bed) reactors can
be used. Conversion of the feed can be defined in terms of
conversion of molecules that boil above a temperature threshold to
molecules below that threshold. The conversion temperature can be
any convenient temperature, such as .about.700.degree. F.
(370.degree. C.) or 1050.degree. F. (566.degree. C.). The amount of
conversion can correspond to the total conversion of molecules
within the combined hydrotreatment and hydrocracking stages for the
deasphalted oil. Suitable amounts of conversion of molecules
boiling above 1050.degree. F. (566.degree. C.) to molecules boiling
below 566.degree. C. include 30 wt % to 90 wt % conversion relative
to 566.degree. C., or 30 wt % to 80 wt %, or 30 wt % to 70 wt %, or
40 wt % to 90 wt %, or 40 wt % to 80 wt %, or 40 wt % to 70 wt %,
or 50 wt % to 90 wt %, or 50 wt % to 80 wt %, or 50 wt % to 70 wt
%. In particular, the amount of conversion relative to 566.degree.
C. can be 30 wt % to 90 wt %, or 30 wt % to 70 wt %, or 50 wt % to
90 wt %. Additionally or alternately, suitable amounts of
conversion of molecules boiling above .about.700.degree. F.
(370.degree. C.) to molecules boiling below 370.degree. C. include
10 wt % to 70 wt % conversion relative to 370.degree. C., or 10 wt
% to 60 wt %, or 10 wt % to 50 wt %, or 20 wt % to 70 wt %, or 20
wt % to 60 wt %, or 20 wt % to 50 wt %, or 30 wt % to 70 wt %, or
30 wt % to 60 wt %, or 30 wt % to 50 wt %. In particular, the
amount of conversion relative to 370.degree. C. can be 10 wt % to
70 wt %, or 20 wt % to 50 wt %, or 30 wt % to 60 wt %.
[0128] The hydroprocessed deasphalted oil can also be characterized
based on the product quality. After hydroprocessing (hydrotreating
and/or hydrocracking), the hydroprocessed deasphalted oil can have
a sulfur content of 200 wppm or less, or 100 wppm or less, or 50
wppm or less (such as down to .about.0 wppm). Additionally or
alternately, the hydroprocessed deasphalted oil can have a nitrogen
content of 200 wppm or less, or 100 wppm or less, or 50 wppm or
less (such as down to .about.0 wppm). Additionally or alternately,
the hydroprocessed deasphalted oil can have a Conradson Carbon
residue content of 1.5 wt % or less, or 1.0 wt % or less, or 0.7 wt
% or less, or 0.1 wt % or less, or 0.02 wt % or less (such as down
to .about.0 wt %). Conradson Carbon residue content can be
determined according to ASTM D4530.
[0129] In various aspects, a feed can initially be exposed to a
demetallization catalyst prior to exposing the feed to a
hydrotreating catalyst. Deasphalted oils can have metals
concentrations (Ni+V+Fe) on the order of 10-100 wppm. Exposing a
conventional hydrotreating catalyst to a feed having a metals
content of 10 wppm or more can lead to catalyst deactivation at a
faster rate than may desirable in a commercial setting. Exposing a
metal containing feed to a demetallization catalyst prior to the
hydrotreating catalyst can allow at least a portion of the metals
to be removed by the demetallization catalyst, which can reduce or
minimize the deactivation of the hydrotreating catalyst and/or
other subsequent catalysts in the process flow. Commercially
available demetallization catalysts can be suitable, such as large
pore amorphous oxide catalysts that may optionally include Group VI
and/or Group VIII non-noble metals to provide some hydrogenation
activity.
[0130] In various aspects, the deasphalted oil can be exposed to a
hydrotreating catalyst under effective hydrotreating conditions.
The catalysts used can include conventional hydroprocessing
catalysts, such as those comprising at least one Group VIII
non-noble metal (Columns 8-10 of IUPAC periodic table), preferably
Fe, Co, and/or Ni, such as Co and/or Ni; and at least one Group VI
metal (Column 6 of IUPAC periodic table), preferably Mo and/or W.
Such hydroprocessing catalysts optionally include transition metal
sulfides that are impregnated or dispersed on a refractory support
or carrier such as alumina and/or silica. The support or carrier
itself typically has no significant/measurable catalytic activity.
Substantially carrier- or support-free catalysts, commonly referred
to as bulk catalysts, generally have higher volumetric activities
than their supported counterparts.
[0131] The catalysts can either be in bulk form or in supported
form. In addition to alumina and/or silica, other suitable
support/carrier materials can include, but are not limited to,
zeolites, titania, silica-titania, and titania-alumina. Suitable
aluminas are porous aluminas such as gamma or eta having average
pore sizes from 50 to 200 .ANG., or 75 to 150 .ANG.; a surface area
from 100 to 300 m.sup.2/g, or 150 to 250 m.sup.2/g; and a pore
volume of from 0.25 to 1.0 cm.sup.3/g, or 0.35 to 0.8 cm.sup.3/g.
More generally, any convenient size, shape, and/or pore size
distribution for a catalyst suitable for hydrotreatment of a
distillate (including lubricant base stock) boiling range feed in a
conventional manner may be used. Preferably, the support or carrier
material is an amorphous support, such as a refractory oxide.
Preferably, the support or carrier material can be free or
substantially free of the presence of molecular sieve, where
substantially free of molecular sieve is defined as having a
content of molecular sieve of less than about 0.01 wt %.
[0132] The at least one Group VIII non-noble metal, in oxide form,
can typically be present in an amount ranging from about 2 wt % to
about 40 wt %, preferably from about 4 wt % to about 15 wt %. The
at least one Group VI metal, in oxide form, can typically be
present in an amount ranging from about 2 wt % to about 70 wt %,
preferably for supported catalysts from about 6 wt % to about 40 wt
% or from about 10 wt % to about 30 wt %. These weight percents are
based on the total weight of the catalyst. Suitable metal catalysts
include cobalt/molybdenum (1-10% Co as oxide, 10-40% Mo as oxide),
nickel/molybdenum (1-10% Ni as oxide, 10-40% Co as oxide), or
nickel/tungsten (1-10% Ni as oxide, 10-40% W as oxide) on alumina,
silica, silica-alumina, or titania.
[0133] The hydrotreatment is carried out in the presence of
hydrogen. A hydrogen stream is, therefore, fed or injected into a
vessel or reaction zone or hydroprocessing zone in which the
hydroprocessing catalyst is located. Hydrogen, which is contained
in a hydrogen "treat gas," is provided to the reaction zone. Treat
gas, as referred to in this invention, can be either pure hydrogen
or a hydrogen-containing gas, which is a gas stream containing
hydrogen in an amount that is sufficient for the intended
reaction(s), optionally including one or more other gasses (e.g.,
nitrogen and light hydrocarbons such as methane). The treat gas
stream introduced into a reaction stage will preferably contain at
least about 50 vol. % and more preferably at least about 75 vol. %
hydrogen. Optionally, the hydrogen treat gas can be substantially
free (less than 1 vol %) of impurities such as H.sub.2S and
NH.sub.3 and/or such impurities can be substantially removed from a
treat gas prior to use.
[0134] Hydrogen can be supplied at a rate of from about 100 SCF/B
(standard cubic feet of hydrogen per barrel of feed) (17
Nm.sup.3/m.sup.3) to about 10000 SCF/B (1700 Nm.sup.3/m.sup.3).
Preferably, the hydrogen is provided in a range of from about 200
SCF/B (34 Nm.sup.3/m.sup.3) to about 2500 SCF/B (420
Nm.sup.3/m.sup.3). Hydrogen can be supplied co-currently with the
input feed to the hydrotreatment reactor and/or reaction zone or
separately via a separate gas conduit to the hydrotreatment
zone.
[0135] Hydrotreating conditions can include temperatures of
200.degree. C. to 450.degree. C., or 315.degree. C. to 425.degree.
C.; pressures of 250 psig (1.8 MPag) to 5000 psig (34.6 MPag) or
300 psig (2.1 MPag) to 3000 psig (20.8 MPag); liquid hourly space
velocities (LHSV) of 0.1 hr.sup.-1 to 10 hr.sup.-1; and hydrogen
treat rates of 200 scf/B (35.6 m.sup.3/m.sup.3) to 10,000 scf/B
(1781 m.sup.3/m.sup.3), or 500 (89 m.sup.3/m.sup.3) to 10,000 scf/B
(1781 m.sup.3/m.sup.3).
[0136] In various aspects, the deasphalted oil can be exposed to a
hydrocracking catalyst under effective hydrocracking conditions.
Hydrocracking catalysts typically contain sulfided base metals on
acidic supports, such as amorphous silica alumina, cracking
zeolites such as USY, or acidified alumina. Often these acidic
supports are mixed or bound with other metal oxides such as
alumina, titania or silica. Examples of suitable acidic supports
include acidic molecular sieves, such as zeolites or
silicoaluminophophates. One example of suitable zeolite is USY,
such as a USY zeolite with cell size of 24.30 Angstroms or less.
Additionally or alternately, the catalyst can be a low acidity
molecular sieve, such as a USY zeolite with a Si to Al ratio of at
least about 20, and preferably at least about 40 or 50. ZSM-48,
such as ZSM-48 with a SiO.sub.2 to Al.sub.2O.sub.3 ratio of about
110 or less, such as about 90 or less, is another example of a
potentially suitable hydrocracking catalyst. Still another option
is to use a combination of USY and ZSM-48. Still other options
include using one or more of zeolite Beta, ZSM-5, ZSM-35, or
ZSM-23, either alone or in combination with a USY catalyst.
Non-limiting examples of metals for hydrocracking catalysts include
metals or combinations of metals that include at least one Group
VIII metal, such as nickel, nickel-cobalt-molybdenum,
cobalt-molybdenum, nickel-tungsten, nickel-molybdenum, and/or
nickel-molybdenum-tungsten. Additionally or alternately,
hydrocracking catalysts with noble metals can also be used.
Non-limiting examples of noble metal catalysts include those based
on platinum and/or palladium. Support materials which may be used
for both the noble and non-noble metal catalysts can comprise a
refractory oxide material such as alumina, silica, alumina-silica,
kieselguhr, diatomaceous earth, magnesia, zirconia, or combinations
thereof, with alumina, silica, alumina-silica being the most common
(and preferred, in one embodiment).
[0137] When only one hydrogenation metal is present on a
hydrocracking catalyst, the amount of that hydrogenation metal can
be at least about 0.1 wt % based on the total weight of the
catalyst, for example at least about 0.5 wt % or at least about 0.6
wt %. Additionally or alternately when only one hydrogenation metal
is present, the amount of that hydrogenation metal can be about 5.0
wt % or less based on the total weight of the catalyst, for example
about 3.5 wt % or less, about 2.5 wt % or less, about 1.5 wt % or
less, about 1.0 wt % or less, about 0.9 wt % or less, about 0.75 wt
% or less, or about 0.6 wt % or less. Further additionally or
alternately when more than one hydrogenation metal is present, the
collective amount of hydrogenation metals can be at least about 0.1
wt % based on the total weight of the catalyst, for example at
least about 0.25 wt %, at least about 0.5 wt %, at least about 0.6
wt %, at least about 0.75 wt %, or at least about 1 wt %. Still
further additionally or alternately when more than one
hydrogenation metal is present, the collective amount of
hydrogenation metals can be about 35 wt % or less based on the
total weight of the catalyst, for example about 30 wt % or less,
about 25 wt % or less, about 20 wt % or less, about 15 wt % or
less, about 10 wt % or less, or about 5 wt % or less. In
embodiments wherein the supported metal comprises a noble metal,
the amount of noble metal(s) is typically less than about 2 wt %,
for example less than about 1 wt %, about 0.9 wt % or less, about
0.75 wt % or less, or about 0.6 wt % or less. It is noted that
hydrocracking under sour conditions is typically performed using a
base metal (or metals) as the hydrogenation metal.
[0138] In various aspects, the conditions selected for
hydrocracking for lubricant base stock production can depend on the
desired level of conversion, the level of contaminants in the input
feed to the hydrocracking stage, and potentially other factors. For
example, hydrocracking conditions in a single stage, or in the
first stage and/or the second stage of a multi-stage system, can be
selected to achieve a desired level of conversion in the reaction
system. Hydrocracking conditions can be referred to as sour
conditions or sweet conditions, depending on the level of sulfur
and/or nitrogen present within a feed. For example, a feed with 100
wppm or less of sulfur and 50 wppm or less of nitrogen, preferably
less than 25 wppm sulfur and/or less than 10 wppm of nitrogen,
represent a feed for hydrocracking under sweet conditions. In
various aspects, hydrocracking can be performed on a thermally
cracked resid, such as a deasphalted oil derived from a thermally
cracked resid. In some aspects, such as aspects where an optional
hydrotreating step is used prior to hydrocracking, the thermally
cracked resid may correspond to a sweet feed. In other aspects, the
thermally cracked resid may represent a feed for hydrocracking
under sour conditions.
[0139] A hydrocracking process under sour conditions can be carried
out at temperatures of about 550.degree. F. (288.degree. C.) to
about 840.degree. F. (449.degree. C.), hydrogen partial pressures
of from about 1500 psig to about 5000 psig (10.3 MPag to 34.6
MPag), liquid hourly space velocities of from 0.05 h.sup.-1 to 10
h.sup.-1, and hydrogen treat gas rates of from 35.6 m.sup.3/m.sup.3
to 1781 m.sup.3/m.sup.3 (200 SCF/B to 10,000 SCF/B). In other
embodiments, the conditions can include temperatures in the range
of about 600.degree. F. (343.degree. C.) to about 815.degree. F.
(435.degree. C.), hydrogen partial pressures of from about 1500
psig to about 3000 psig (10.3 MPag-20.9 MPag), and hydrogen treat
gas rates of from about 213 m.sup.3/m.sup.3 to about 1068
m.sup.3/m.sup.3 (1200 SCF/B to 6000 SCF/B). The LHSV can be from
about 0.25 h.sup.-1 to about 50 h.sup.-1, or from about 0.5
h.sup.-1 to about 20 h.sup.-1, preferably from about 1.0 h.sup.-1
to about 4.0 h.sup.-1.
[0140] In some aspects, a portion of the hydrocracking catalyst can
be contained in a second reactor stage. In such aspects, a first
reaction stage of the hydroprocessing reaction system can include
one or more hydrotreating and/or hydrocracking catalysts. The
conditions in the first reaction stage can be suitable for reducing
the sulfur and/or nitrogen content of the feedstock. A separator
can then be used in between the first and second stages of the
reaction system to remove gas phase sulfur and nitrogen
contaminants. One option for the separator is to simply perform a
gas-liquid separation to remove contaminant. Another option is to
use a separator such as a flash separator that can perform a
separation at a higher temperature. Such a high temperature
separator can be used, for example, to separate the feed into a
portion boiling below a temperature cut point, such as about
350.degree. F. (177.degree. C.) or about 400.degree. F.
(204.degree. C.), and a portion boiling above the temperature cut
point. In this type of separation, the naphtha boiling range
portion of the effluent from the first reaction stage can also be
removed, thus reducing the volume of effluent that is processed in
the second or other subsequent stages. Of course, any low boiling
contaminants in the effluent from the first stage would also be
separated into the portion boiling below the temperature cut point.
If sufficient contaminant removal is performed in the first stage,
the second stage can be operated as a "sweet" or low contaminant
stage.
[0141] Still another option can be to use a separator between the
first and second stages of the hydroprocessing reaction system that
can also perform at least a partial fractionation of the effluent
from the first stage. In this type of aspect, the effluent from the
first hydroprocessing stage can be separated into at least a
portion boiling below the distillate (such as diesel) fuel range, a
portion boiling in the distillate fuel range, and a portion boiling
above the distillate fuel range. The distillate fuel range can be
defined based on a conventional diesel boiling range, such as
having a lower end cut point temperature of at least about
350.degree. F. (177.degree. C.) or at least about 400.degree. F.
(204.degree. C.) to having an upper end cut point temperature of
about 700.degree. F. (371.degree. C.) or less or 650.degree. F.
(343.degree. C.) or less. Optionally, the distillate fuel range can
be extended to include additional kerosene, such as by selecting a
lower end cut point temperature of at least about 300.degree. F.
(149.degree. C.).
[0142] In aspects where the inter-stage separator is also used to
produce a distillate fuel fraction, the portion boiling below the
distillate fuel fraction includes, naphtha boiling range molecules,
light ends, and contaminants such as H.sub.2S. These different
products can be separated from each other in any convenient manner.
Similarly, one or more distillate fuel fractions can be formed, if
desired, from the distillate boiling range fraction. The portion
boiling above the distillate fuel range represents the potential
lubricant base stocks. In such aspects, the portion boiling above
the distillate fuel range is subjected to further hydroprocessing
in a second hydroprocessing stage.
[0143] A hydrocracking process under sweet conditions can be
performed under conditions similar to those used for a sour
hydrocracking process, or the conditions can be different. In an
embodiment, the conditions in a sweet hydrocracking stage can have
less severe conditions than a hydrocracking process in a sour
stage. Suitable hydrocracking conditions for a non-sour stage can
include, but are not limited to, conditions similar to a first or
sour stage. Suitable hydrocracking conditions can include
temperatures of about 500.degree. F. (260.degree. C.) to about
840.degree. F. (449.degree. C.), hydrogen partial pressures of from
about 1500 psig to about 5000 psig (10.3 MPag to 34.6 MPag), liquid
hourly space velocities of from 0.05 h.sup.-1 to 10 h.sup.-1, and
hydrogen treat gas rates of from 35.6 m.sup.3/m.sup.3 to 1781
m.sup.3/m.sup.3 (200 SCF/B to 10,000 SCF/B). In other embodiments,
the conditions can include temperatures in the range of about
600.degree. F. (343.degree. C.) to about 815.degree. F.
(435.degree. C.), hydrogen partial pressures of from about 1500
psig to about 3000 psig (10.3 MPag-20.9 MPag), and hydrogen treat
gas rates of from about 213 m.sup.3/m.sup.3 to about 1068
m.sup.3/m.sup.3 (1200 SCF/B to 6000 SCF/B). The LHSV can be from
about 0.25 h.sup.-1 to about 50 h.sup.-1, or from about 0.5
h.sup.-1 to about 20 h.sup.-1, preferably from about 1.0 h.sup.-1
to about 4.0 h.sup.-1.
[0144] In still another aspect, the same conditions can be used for
hydrotreating and hydrocracking beds or stages, such as using
hydrotreating conditions for both or using hydrocracking conditions
for both. In yet another embodiment, the pressure for the
hydrotreating and hydrocracking beds or stages can be the same.
[0145] In yet another aspect, a hydroprocessing reaction system may
include more than one hydrocracking stage. If multiple
hydrocracking stages are present, at least one hydrocracking stage
can have effective hydrocracking conditions as described above,
including a hydrogen partial pressure of at least about 1500 psig
(10.3 MPag). In such an aspect, other hydrocracking processes can
be performed under conditions that may include lower hydrogen
partial pressures. Suitable hydrocracking conditions for an
additional hydrocracking stage can include, but are not limited to,
temperatures of about 500.degree. F. (260.degree. C.) to about
840.degree. F. (449.degree. C.), hydrogen partial pressures of from
about 250 psig to about 5000 psig (1.8 MPag to 34.6 MPag), liquid
hourly space velocities of from 0.05 h.sup.-1 to 10 h.sup.-1, and
hydrogen treat gas rates of from 35.6 m.sup.3/m.sup.3 to 1781
m.sup.3/m.sup.3 (200 SCF/B to 10,000 SCF/B). In other embodiments,
the conditions for an additional hydrocracking stage can include
temperatures in the range of about 600.degree. F. (343.degree. C.)
to about 815.degree. F. (435.degree. C.), hydrogen partial
pressures of from about 500 psig to about 3000 psig (3.5 MPag-20.9
MPag), and hydrogen treat gas rates of from about 213
m.sup.3/m.sup.3 to about 1068 m.sup.3/m.sup.3 (1200 SCF/B to 6000
SCF/B). The LHSV can be from about 0.25 h.sup.-1 to about 50
h.sup.-1, or from about 0.5 h.sup.-1 to about 20 h.sup.-1, and
preferably from about 1.0 h.sup.-1 to about 4.0 h.sup.-1.
Additional Hydroprocessing--Hydrocracking, Catalytic Dewaxing, and
Hydrofinishing
[0146] In some alternative aspects, at least a lubricant boiling
range portion of the hydroprocessed deasphalted oil can be exposed
to further hydroprocessing (including catalytic dewaxing) to form
either Group I and/or Group II base stocks, including Group I
and/or Group II bright stock. In some aspects, a first lubricant
boiling range portion of the hydroprocessed deasphalted oil can be
solvent dewaxed as described above while a second lubricant boiling
range portion can be exposed to further hydroprocessing. In other
aspects, only solvent dewaxing or only further hydroprocessing can
be used to treat a lubricant boiling range portion of the
hydroprocessed deasphalted oil.
[0147] Optionally, the further hydroprocessing of the lubricant
boiling range portion of the hydroprocessed deasphalted oil can
also include exposure to hydrocracking conditions before and/or
after the exposure to the catalytic dewaxing conditions. At this
point in the process, the hydrocracking can be considered "sweet"
hydrocracking, as the hydroprocessed deasphalted oil can have a
sulfur content of 200 wppm or less.
[0148] Suitable hydrocracking conditions can include exposing the
feed to a hydrocracking catalyst as previously described above.
Optionally, it can be preferable to use a USY zeolite with a silica
to alumina ratio of at least 30 and a unit cell size of less than
24.32 Angstroms as the zeolite for the hydrocracking catalyst, in
order to improve the VI uplift from hydrocracking and/or to improve
the ratio of distillate fuel yield to naphtha fuel yield in the
fuels boiling range product.
[0149] Suitable hydrocracking conditions can also include
temperatures of about 500.degree. F. (260.degree. C.) to about
840.degree. F. (449.degree. C.), hydrogen partial pressures of from
about 1500 psig to about 5000 psig (10.3 MPag to 34.6 MPag), liquid
hourly space velocities of from 0.05 h.sup.-1 to 10 h.sup.-1, and
hydrogen treat gas rates of from 35.6 m.sup.3/m.sup.3 to 1781
m.sup.3/m.sup.3 (200 SCF/B to 10,000 SCF/B). In other embodiments,
the conditions can include temperatures in the range of about
600.degree. F. (343.degree. C.) to about 815.degree. F.
(435.degree. C.), hydrogen partial pressures of from about 1500
psig to about 3000 psig (10.3 MPag-20.9 MPag), and hydrogen treat
gas rates of from about 213 m.sup.3/m.sup.3 to about 1068
m.sup.3/m.sup.3 (1200 SCF/B to 6000 SCF/B). The LHSV can be from
about 0.25 h.sup.-1 to about 50 h.sup.-1, or from about 0.5
h.sup.-1 to about 20 h.sup.-1, and preferably from about 1.0
h.sup.-1 to about 4.0 h.sup.-1.
[0150] For catalytic dewaxing, suitable dewaxing catalysts can
include molecular sieves such as crystalline aluminosilicates
(zeolites). In an embodiment, the molecular sieve can comprise,
consist essentially of, or be ZSM-22, ZSM-23, ZSM-48. Optionally
but preferably, molecular sieves that are selective for dewaxing by
isomerization as opposed to cracking can be used, such as ZSM-48,
ZSM-23, or a combination thereof. Additionally or alternately, the
molecular sieve can comprise, consist essentially of, or be a
10-member ring 1-D molecular sieve, such as EU-2, EU-11, ZBM-30,
ZSM-48, or ZSM-23. ZSM-48 is most preferred. Note that a zeolite
having the ZSM-23 structure with a silica to alumina ratio of from
about 20:1 to about 40:1 can sometimes be referred to as SSZ-32.
Optionally but preferably, the dewaxing catalyst can include a
binder for the molecular sieve, such as alumina, titania, silica,
silica-alumina, zirconia, or a combination thereof, for example
alumina and/or titania or silica and/or zirconia and/or
titania.
[0151] Preferably, the dewaxing catalysts used in processes
according to the invention are catalysts with a low ratio of silica
to alumina. For example, for ZSM-48, the ratio of silica to alumina
in the zeolite can be about 100:1 or less, such as about 90:1 or
less, or about 75:1 or less, or about 70:1 or less. Additionally or
alternately, the ratio of silica to alumina in the ZSM-48 can be at
least about 50:1, such as at least about 60:1, or at least about
65:1.
[0152] In various embodiments, the catalysts according to the
invention further include a metal hydrogenation component. The
metal hydrogenation component is typically a Group VI and/or a
Group VIII metal. Preferably, the metal hydrogenation component can
be a combination of a non-noble Group VIII metal with a Group VI
metal. Suitable combinations can include Ni, Co, or Fe with Mo or
W, preferably Ni with Mo or W.
[0153] The metal hydrogenation component may be added to the
catalyst in any convenient manner. One technique for adding the
metal hydrogenation component is by incipient wetness. For example,
after combining a zeolite and a binder, the combined zeolite and
binder can be extruded into catalyst particles. These catalyst
particles can then be exposed to a solution containing a suitable
metal precursor. Alternatively, metal can be added to the catalyst
by ion exchange, where a metal precursor is added to a mixture of
zeolite (or zeolite and binder) prior to extrusion.
[0154] The amount of metal in the catalyst can be at least 0.1 wt %
based on catalyst, or at least 0.5 wt %, or at least 1.0 wt %, or
at least 2.5 wt %, or at least 5.0 wt %, based on catalyst. The
amount of metal in the catalyst can be 20 wt % or less based on
catalyst, or 10 wt % or less, or 5 wt % or less, or 2.5 wt % or
less, or 1 wt % or less. For embodiments where the metal is a
combination of a non-noble Group VIII metal with a Group VI metal,
the combined amount of metal can be from 0.5 wt % to 20 wt %, or 1
wt % to 15 wt %, or 2.5 wt % to 10 wt %.
[0155] The dewaxing catalysts useful in processes according to the
invention can also include a binder. In some embodiments, the
dewaxing catalysts used in process according to the invention are
formulated using a low surface area binder, a low surface area
binder represents a binder with a surface area of 100 m.sup.2/g or
less, or 80 m.sup.2/g or less, or 70 m.sup.2/g or less.
Additionally or alternately, the binder can have a surface area of
at least about 25 m.sup.2/g. The amount of zeolite in a catalyst
formulated using a binder can be from about 30 wt % zeolite to 90
wt % zeolite relative to the combined weight of binder and zeolite.
Preferably, the amount of zeolite is at least about 50 wt % of the
combined weight of zeolite and binder, such as at least about 60 wt
% or from about 65 wt % to about 80 wt %.
[0156] Without being bound by any particular theory, it is believed
that use of a low surface area binder reduces the amount of binder
surface area available for the hydrogenation metals supported on
the catalyst. This leads to an increase in the amount of
hydrogenation metals that are supported within the pores of the
molecular sieve in the catalyst.
[0157] A zeolite can be combined with binder in any convenient
manner. For example, a bound catalyst can be produced by starting
with powders of both the zeolite and binder, combining and mulling
the powders with added water to form a mixture, and then extruding
the mixture to produce a bound catalyst of a desired size.
Extrusion aids can also be used to modify the extrusion flow
properties of the zeolite and binder mixture. The amount of
framework alumina in the catalyst may range from 0.1 to 3.33 wt %,
or 0.1 to 2.7 wt %, or 0.2 to 2 wt %, or 0.3 to 1 wt %.
[0158] Effective conditions for catalytic dewaxing of a feedstock
in the presence of a dewaxing catalyst can include a temperature of
from 280.degree. C. to 450.degree. C., preferably 343.degree. C. to
435.degree. C., a hydrogen partial pressure of from 3.5 MPag to
34.6 MPag (500 psig to 5000 psig), preferably 4.8 MPag to 20.8
MPag, and a hydrogen circulation rate of from 178 m.sup.3/m.sup.3
(1000 SCF/B) to 1781 m.sup.3/m.sup.3 (10,000 scf/B), preferably 213
m.sup.3/m.sup.3 (1200 SCF/B) to 1068 m.sup.3/m.sup.3 (6000 SCF/B).
The LHSV can be from about 0.2 to about 10 h.sup.-1, such as from
about 0.5 h.sup.-1 to about 5 and/or from about 1 h.sup.-1 to about
4 h.sup.-1.
[0159] Before and/or after catalytic dewaxing, the hydroprocessed
deasphalted oil (i.e., at least a lubricant boiling range portion
thereof) can optionally be exposed to an aromatic saturation
catalyst, which can alternatively be referred to as a
hydrofinishing catalyst. Exposure to the aromatic saturation
catalyst can occur either before or after fractionation. If
aromatic saturation occurs after fractionation, the aromatic
saturation can be performed on one or more portions of the
fractionated product. Alternatively, the entire effluent from the
last hydrocracking or dewaxing process can be hydrofinished and/or
undergo aromatic saturation.
[0160] Hydrofinishing and/or aromatic saturation catalysts can
include catalysts containing Group VI metals, Group VIII metals,
and mixtures thereof. In an embodiment, preferred metals include at
least one metal sulfide having a strong hydrogenation function. In
another embodiment, the hydrofinishing catalyst can include a Group
VIII noble metal, such as Pt, Pd, or a combination thereof. The
mixture of metals may also be present as bulk metal catalysts
wherein the amount of metal is about 30 wt. % or greater based on
catalyst. For supported hydrotreating catalysts, suitable metal
oxide supports include low acidic oxides such as silica, alumina,
silica-aluminas or titania, preferably alumina. The preferred
hydrofinishing catalysts for aromatic saturation will comprise at
least one metal having relatively strong hydrogenation function on
a porous support. Typical support materials include amorphous or
crystalline oxide materials such as alumina, silica, and
silica-alumina. The support materials may also be modified, such as
by halogenation, or in particular fluorination. The metal content
of the catalyst is often as high as about 20 weight percent for
non-noble metals. In an embodiment, a preferred hydrofinishing
catalyst can include a crystalline material belonging to the M41S
class or family of catalysts. The M41S family of catalysts are
mesoporous materials having high silica content. Examples include
MCM-41, MCM-48 and MCM-50. A preferred member of this class is
MCM-41.
[0161] Hydrofinishing conditions can include temperatures from
about 125.degree. C. to about 425.degree. C., preferably about
180.degree. C. to about 280.degree. C., a hydrogen partial pressure
from about 500 psig (3.4 MPa) to about 3000 psig (20.7 MPa),
preferably about 1500 psig (10.3 MPa) to about 2500 psig (17.2
MPa), and liquid hourly space velocity from about 0.1 hr.sup.-1 to
about 5 hr.sup.-1 LHSV, preferably about 0.5 hr.sup.-1 to about 1.5
hr.sup.-1. Additionally, a hydrogen treat gas rate of from 35.6
m.sup.3/m.sup.3 to 1781 m.sup.3/m.sup.3 (200 SCF/B to 10,000 SCF/B)
can be used.
Solvent Processing of Catalytically Dewaxed Effluent or Input Flow
to Catalytic Dewaxing
[0162] For deasphalted oils derived from propane deasphalting, the
further hydroprocessing (including catalytic dewaxing) can be
sufficient to form lubricant base stocks with low haze formation
and unexpected compositional properties. For deasphalted oils
derived from C.sub.4+ deasphalting, after the further
hydroprocessing (including catalytic dewaxing), the resulting
catalytically dewaxed effluent can be solvent processed to form one
or more lubricant base stock products with a reduced or eliminated
tendency to form haze. The type of solvent processing can be
dependent on the nature of the initial hydroprocessing
(hydrotreatment and/or hydrocracking) and the nature of the further
hydroprocessing (including dewaxing).
[0163] In aspects where the initial hydroprocessing is less severe,
corresponding to 10 wt % to 40 wt % conversion relative to
.about.700.degree. F. (370.degree. C.), the subsequent solvent
processing can correspond to solvent dewaxing. The solvent dewaxing
can be performed in a manner similar to the solvent dewaxing
described above. However, this solvent dewaxing can be used to
produce a Group II lubricant base stock. In some aspects, when the
initial hydroprocessing corresponds to 10 wt % to 40 wt %
conversion relative to 370.degree. C., the catalytic dewaxing
during further hydroprocessing can also be performed at lower
severity, so that at least 6 wt % wax remains in the catalytically
dewaxed effluent, or at least 8 wt %, or at least 10 wt %, or at
least 12 wt %, or at least 15 wt %, such as up to 20 wt %. The
solvent dewaxing can then be used to reduce the wax content in the
catalytically dewaxed effluent by 2 wt % to 10 wt %. This can
produce a solvent dewaxed oil product having a wax content of 0.1
wt % to 12 wt %, or 0.1 wt % to 10 wt %, or 0.1 wt % to 8 wt %, or
0.1 wt % to 6 wt %, or 1 wt % to 12 wt %, or 1 wt % to 10 wt %, or
1 wt % to 8 wt %, or 4 wt % to 12 wt %, or 4 wt % to 10 wt %, or 4
wt % to 8 wt %, or 6 wt % to 12 wt %, or 6 wt % to 10 wt %. In
particular, the solvent dewaxed oil can have a wax content of 0.1
wt % to 12 wt %, or 0.1 wt % to 6 wt %, or 1 wt % to 10 wt %, or 4
wt % to 12 wt %.
[0164] In other aspects, the subsequent solvent processing can
correspond to solvent extraction. Solvent extraction can be used to
reduce the aromatics content and/or the amount of polar molecules.
The solvent extraction process selectively dissolves aromatic
components to form an aromatics-rich extract phase while leaving
the more paraffinic components in an aromatics-poor raffinate
phase. Naphthenes are distributed between the extract and raffinate
phases. Typical solvents for solvent extraction include phenol,
furfural and N-methyl pyrrolidone. By controlling the solvent to
oil ratio, extraction temperature and method of contacting
distillate to be extracted with solvent, one can control the degree
of separation between the extract and raffinate phases. Any
convenient type of liquid-liquid extractor can be used, such as a
counter-current liquid-liquid extractor. Depending on the initial
concentration of aromatics in the deasphalted oil, the raffinate
phase can have an aromatics content of 5 wt % to 25 wt %. For
typical feeds, the aromatics contents can be at least 10 wt %.
[0165] Optionally, the raffinate from the solvent extraction can be
under-extracted. In such aspects, the extraction is carried out
under conditions such that the raffinate yield is maximized while
still removing most of the lowest quality molecules from the feed.
Raffinate yield may be maximized by controlling extraction
conditions, for example, by lowering the solvent to oil treat ratio
and/or decreasing the extraction temperature. In various aspects,
the raffinate yield from solvent extraction can be at least 40 wt
%, or at least 50 wt %, or at least 60 wt %, or at least 70 wt
%.
[0166] The solvent processed oil (solvent dewaxed or solvent
extracted) can have a pour point of -6.degree. C. or less, or
-10.degree. C. or less, or -15.degree. C. or less, or -20.degree.
C. or less, depending on the nature of the target lubricant base
stock product. Additionally or alternately, the solvent processed
oil (solvent dewaxed or solvent extracted) can have a cloud point
of -2.degree. C. or less, or -5.degree. C. or less, or -10.degree.
C. or less, depending on the nature of the target lubricant base
stock product. Pour points and cloud points can be determined
according to ASTM D97 and ASTM D2500, respectively. The resulting
solvent processed oil can be suitable for use in forming one or
more types of Group II base stocks. The resulting solvent dewaxed
oil can have a viscosity index of at least 80, or at least 90, or
at least 95, or at least 100, or at least 110, or at least 120.
Viscosity index can be determined according to ASTM D2270.
Preferably, at least 10 wt % of the resulting solvent processed oil
(or at least 20 wt %, or at least 30 wt %) can correspond to a
Group II bright stock having a kinematic viscosity at 100.degree.
C. of at least 14 cSt, or at least 15 cSt, or at least 20 cSt, or
at least 25 cSt, or at least 30 cSt, or at least 32 cSt, such as up
to 50 cSt or more. Additionally or alternately, the Group II bright
stock can have a kinematic viscosity at 40.degree. C. of at least
300 cSt, or at least 320 cSt, or at least 340 cSt, or at least 350
cSt, such as up to 500 cSt or more. Kinematic viscosity can be
determined according to ASTM D445. Additionally or alternately, the
Conradson Carbon residue content can be about 0.1 wt % or less, or
about 0.02 wt % or less. Conradson Carbon residue content can be
determined according to ASTM D4530. Additionally or alternately,
the resulting base stock can have a turbidity of at least 1.5 (in
combination with a cloud point of less than 0.degree. C.), or can
have a turbidity of at least 2.0, and/or can have a turbidity of
4.0 or less, or 3.5 or less, or 3.0 or less. In particular, the
turbidity can be 1.5 to 4.0, or 1.5 to 3.0, or 2.0 to 4.0, or 2.0
to 3.5.
[0167] The reduced or eliminated tendency to form haze for the
lubricant base stocks formed from the solvent processed oil can be
demonstrated by the reduced or minimized difference between the
cloud point temperature and pour point temperature for the
lubricant base stocks. In various aspects, the difference between
the cloud point and pour point for the resulting solvent dewaxed
oil and/or for one or more Group II lubricant base stocks,
including one or more bright stocks, formed from the solvent
processed oil, can be 22.degree. C. or less, or 20.degree. C. or
less, or 15.degree. C. or less, or 10.degree. C. or less, such as
down to about 1.degree. C. of difference.
[0168] In some alternative aspects, the above solvent processing
can be performed prior to catalytic dewaxing.
Group II Base Stock Products
[0169] For deasphalted oils derived from propane, butane, pentane,
hexane and higher or mixtures thereof, the further hydroprocessing
(including catalytic dewaxing) and potentially solvent processing
can be sufficient to form lubricant base stocks with low haze
formation (or no haze formation) and novel compositional
properties. Traditional products manufactured today with kinematic
viscosity of about 32 cSt at 100.degree. C. contain aromatics that
are >10% and/or sulfur that is >0.03% of the base oil.
[0170] In various aspects, base stocks produced according to
methods described herein can have a kinematic viscosity of at least
14 cSt, or at least 20 cSt, or at least 25 cSt, or at least 30 cSt,
or at least 32 cSt at 100.degree. C. and can contain less than 10
wt % aromatics/greater than 90 wt % saturates and less than 0.03%
sulfur. Optionally, the saturates content can be still higher, such
as greater than 95 wt %, or greater than 97 wt %.
[0171] Base oils of the compositions described above have further
been found to provide the advantage of being haze free upon initial
production and remaining haze free for extended periods of time.
This is an advantage over the prior art of high saturates heavy
base stocks that was unexpected.
[0172] Additionally, it has been found that these base stocks can
be blended with additives to form formulated lubricants, such as
but not limited to marine oils, engine oils, greases, paper machine
oils, and gear oils. These additives may include, but are not
restricted to, detergents, dispersants, antioxidants, viscosity
modifiers, and pour point depressants. More generally, a formulated
lubricating including a base stock produced from a deasphalted oil
may additionally contain one or more of the other commonly used
lubricating oil performance additives including but not limited to
antiwear agents, dispersants, other detergents, corrosion
inhibitors, rust inhibitors, metal deactivators, extreme pressure
additives, anti-seizure agents, wax modifiers, viscosity index
improvers, viscosity modifiers, fluid-loss additives, seal
compatibility agents, friction modifiers, lubricity agents,
anti-staining agents, chromophoric agents, defoamants,
demulsifiers, emulsifiers, densifiers, wetting agents, gelling
agents, tackiness agents, colorants, and others. For a review of
many commonly used additives, see Klamann in Lubricants and Related
Products, Verlag Chemie, Deerfield Beach, Fla.; ISBN 0-89573-177-0.
These additives are commonly delivered with varying amounts of
diluent oil, that may range from 5 weight percent to 50 weight
percent.
[0173] When so blended, the performance as measured by standard low
temperature tests such as the Mini-Rotary Viscometer (MRV) and
Brookfield test has been shown to be superior to formulations
blended with traditional base oils.
[0174] It has also been found that the oxidation performance, when
blended into industrial oils using common additives such as, but
not restricted to, defoamants, pour point depressants,
antioxidants, rust inhibitors, has exemplified superior oxidation
performance in standard oxidation tests such as the US Steel
Oxidation test compared to traditional base stocks.
[0175] Other performance parameters such as interfacial properties,
deposit control, storage stability, and toxicity have also been
examined and are similar to or better than traditional base
oils.
[0176] In addition to being blended with additives, the base stocks
described herein can also be blended with other base stocks to make
a base oil. These other base stocks include solvent processed base
stocks, hydroprocessed base stocks, synthetic base stocks, base
stocks derived from Fisher-Tropsch processes, PAO, and naphthenic
base stocks. Additionally or alternately, the other base stocks can
include Group I base stocks, Group II base stocks, Group III base
stocks, Group IV base stocks, and/or Group V base stocks.
Additionally or alternately, still other types of base stocks for
blending can include hydrocarbyl aromatics, alkylated aromatics,
esters (including synthetic and/or renewable esters), and or other
non-conventional or unconventional base stocks. These base oil
blends of the inventive base stock and other base stocks can also
be combined with additives, such as those mentioned above, to make
formulated lubricants.
Configuration Examples
[0177] FIGS. 1 to 3 show examples of using blocked operation and/or
partial product recycle during lubricant production based on a feed
including deasphalted resid. In FIGS. 1 to 3, after initial sour
stage processing, the hydroprocessed effluent is fractionated to
form light neutral, heavy neutral, and brightstock portions. FIG. 1
shows an example of the process flow during processing to form
light neutral base stock. FIG. 2 shows an example of the process
flow during processing to form heavy neutral base stock. FIG. 3
shows an example of the process flow during processing to form
brightstock.
[0178] In FIG. 1, a feed 705 is introduced into a deasphalter 710.
The deasphalter 710 generates a deasphalted oil 715 and deasphalter
rock or residue 718. The deasphalted oil 715 is then processed in a
sour processing stage 720. Optionally, a portion 771 of recycled
light neutral base product 762 can be combined with deasphalted oil
715. Sour processing stage 720 can include one or more of a
deasphalting catalyst, a hydrotreating catalyst, a hydrocracking
catalyst, and/or an aromatic saturation catalyst. The conditions in
sour processing stage 720 can be selected to at least reduce the
sulfur content of the hydroprocessed effluent 725 to 20 wppm or
less. This can correspond to 15 wt % to 40 wt % conversion of the
feed relative to 370.degree. C. Optionally, the amount of
conversion in the sour processing stage 720 can be any convenient
higher amount so long as the combined conversion in sour processing
stage 720 and sweet processing stage 750 is 90 wt % or less.
[0179] The hydroprocessed effluent 725 can then be passed into
fractionation stage 730 for separation into a plurality of
fractions. In the example shown in FIG. 1, the hydroprocessed
effluent is separated into a light neutral portion 732, a heavy
neutral portion 734, and a brightstock portion 736. To allow for
blocked operation, the light neutral portion 732 can be sent to
corresponding light neutral storage 742, the heavy neutral portion
734 can be sent to corresponding heavy neutral storage 744, and the
brightstock portion 736 can be sent to corresponding brightstock
storage 746. A lower boiling range fraction 731 corresponding to
fuels and/or light ends can also be generated by fractionation
stage 730. Optionally, fractionation stage can generate a plurality
of lower boiling range fractions 731.
[0180] FIG. 1 shows an example of the processing system during a
light neutral processing block. In FIG. 1, the feed 752 to sweet
processing stage 750 corresponds to a feed derived from light
neutral storage 742. The sweet processing stage 750 can include at
least dewaxing catalyst, and optionally can further include one or
more of hydrocracking catalyst and aromatics saturation catalyst.
The dewaxed effluent 755 from sweet processing stage 750 can then
be passed into a fractionator 760 to form light neutral base stock
product 762. A lower boiling fraction 761 corresponding to fuels
and/or light ends can also be separated out by fractionator 760.
Optionally, a portion of light neutral base stock 762 can be
recycled. The recycled portion of light neutral base stock 762 can
be used as a recycled feed portion 771 and/or as a recycled portion
772 that is added to light neutral storage 742. Recycling a portion
771 for use as part of the feed can be beneficial for increasing
the lifetime of the catalysts in sour processing stage 720.
Recycling a portion 772 to light neutral storage 742 can be
beneficial for increasing conversion and/or VI.
[0181] FIG. 2 shows the same processing configuration during
processing of a heavy neutral block. In FIG. 2, the feed 754 to
sweet processing stage 750 is derived from heavy neutral storage
744. The dewaxed effluent 755 from sweet processing stage 750 can
be fractionated 760 to form lower boiling portion 761, heavy
neutral base stock product 764, and light neutral base stock
product 762. Because block operation to form a heavy neutral base
stock results in production of both a light neutral product 762 and
a heavy neutral product 764, various optional recycle streams can
also be used. In the example shown in FIG. 2, optional recycle
portions 771 and 772 can be used for recycle of the light neutral
product 762. Additionally, optional recycle portions 781 and 784
can be used for recycle of the heavy neutral product 764. Recycle
portions 781 and 784 can provide similar benefits to those for
recycle portions 771 and/or 772.
[0182] FIG. 3 shows the same processing configuration during
processing of a bright stock block. In FIG. 3, the feed 756 to
sweet processing stage 750 is derived from bright stock storage
746. The dewaxed effluent 755 from sweet processing stage 750 can
be fractionated 760 to form lower boiling portion 761, bottoms
product 766, heavy neutral base stock product 764, and light
neutral base stock product 762. Bottoms product 766 can then be
extracted 790 to form a bright stock product 768. The aromatic
extract 793 produced in extractor 790 can be recycled for use, for
example, as part of the feed to deasphalter 710.
[0183] Because block operation to form a bright stock results in
production of a bright stock product 768 as well as a light neutral
product 762 and a heavy neutral product 764, various optional
recycle streams can also be used. In the example shown in FIG. 3,
optional recycle portions 771 and 772 can be used for recycle of
the light neutral product 762, while optional recycle portions 781
and 784 can be used for recycle of the heavy neutral product 764.
Additionally, optional recycle portions 791 and 796 can be used for
recycle of the bottoms product 766. Recycle portions 791 and 796
can provide similar benefits to those for recycle portions 771,
772, 781, and/or 784.
[0184] Recycle of a portion of the products can also be used in
conjunction with wide cut processing of a larger portion of the
lubricant boiling range feed to the second stage, such as
processing substantially all of the feed to the second stage for
lubricant production as a wide cut feed. FIG. 6 shows an example of
a configuration for processing of a wide cut lubricant feed in the
second (sweet) stage, with various optional recycle streams. The
configuration is similar to the configuration shown in FIG. 3.
However, instead of using a feed 756 derived from feed storage 746
for forming a brightstock, the configuration in FIG. 6 uses the
bottoms 738 from fractionator 730 as the feed to the sweet stage
750.
[0185] Recycle of intermediate products from the sour stage can
also be beneficial in some circumstances. FIG. 7 shows an example
of a configuration for block processing to form lubricant products
where various recycle options are available within the sour
processing stage. Of course, the recycle options shown in FIG. 7
can be used in conjunction with any of the configurations shown in
FIGS. 3 to 6.
[0186] In FIG. 7, feed 805 is introduced into deasphalter 810.
Optionally, a portion of recycled bottoms 893 from fractionator 830
can be included as part of feed 805. This can generate a
deasphalter rock fraction 818 and a deasphalted oil 815.
Deasphalted oil 815 can be passed into sour processing stage 820,
which can include (for example) catalysts for demetallization,
hydrotreating, and hydrocracking. Sour processing stage 820 can
produce a sour stage effluent 825, which is passed into
fractionator 830. Fractionator 830 can generate various feeds for
production of lubricant boiling range products, such as a light
neutral base stock feed 832 (for storage 842), a heavy neutral base
stock feed 834 (for storage 844), and a brightstock feed 836 (for
storage 846). Optionally, a portion of light neutral base stock
feed 832 can be recycled 871 for combination with deasphalted oil
815. Additionally or alternately, a portion of heavy neutral base
stock feed 834 can optionally be recycled 881 for combination with
deasphalted oil 815. Additionally or alternately, a portion of
brightstock feed 836 can optionally be recycled 891 for combination
with deasphalted oil 815.
[0187] After the sour stage, the configuration in FIG. 7 can
operate in a manner similar to the configurations shown in FIGS. 3
to 5. In FIG. 7, the block operation of the configuration is shown
during a time period when brightstock is being produced. Thus, the
feed 856 to the sweet processing stage 850 is derived from
brightstock storage 846. The effluent 855 from sweet processing
stage 850 can then be fractionated 860 to form, for example, light
ends fraction 861, a light neutral base stock product 862, a heavy
neutral base stock product 864, and a brightstock product 866.
Optionally, the brightstock product 866 can be extracted 890 to
form an extracted brightstock product 868.
Example 1--Viscosity and Viscosity Index Relationships
[0188] FIG. 4 shows an example of the relationship between
processing severity, kinematic viscosity, and viscosity index for
lubricant base stocks formed from a deasphalted oil. The data in
FIG. 4 corresponds to lubricant base stocks formed from a pentane
deasphalted oil at 75 wt % yield on resid feed. The deasphalted oil
had a solvent dewaxed VI of 75.8 and a solvent dewaxed kinematic
viscosity at 100.degree. C. of 333.65.
[0189] In FIG. 4, kinematic viscosities (right axis) and viscosity
indexes (left axis) are shown as a function of hydroprocessing
severity (510.degree. C.+ conversion) for a deasphalted oil
processed in a configuration similar to FIG. 4. As shown in FIG. 4,
increasing the hydroprocessing severity can provide VI uplift so
that deasphalted oil can be converted (after solvent dewaxing) to
lubricant base stocks. However, increasing severity also reduces
the kinematic viscosity of the 510.degree. C.+ portion of the base
stock, which can limit the yield of bright stock. The 370.degree.
C.-510.degree. C. portion of the solvent dewaxed product can be
suitable for forming light neutral and/or heavy neutral base
stocks, while the 510.degree. C.+ portion can be suitable for
forming bright stocks and/or heavy neutral base stocks.
Example 2--Variations in Sweet and Sour Hydrocracking
[0190] In addition to providing a method for forming Group II base
stocks from a challenged feed, the methods described herein can
also be used to control the distribution of base stocks formed from
a feed by varying the amount of conversion performed in sour
conditions versus sweet conditions. This is illustrated by the
results shown in FIG. 5.
[0191] In FIG. 5, the upper two curves show the relationship
between the cut point used for forming a lubricant base stock of a
desired viscosity (bottom axis) and the viscosity index of the
resulting base stock (left axis). The curve corresponding to the
circle data points represents processing of a C.sub.5 deasphalted
oil using a configuration similar to FIG. 6, with all of the
hydrocracking occurring in the sour stage. The curve corresponding
to the square data points corresponds to performing roughly half of
the hydrocracking conversion in the sour stage and the remaining
hydrocracking conversion in the sweet stage (along with the
catalytic dewaxing). The individual data points in each of the
upper curves represent the yield of each of the different base
stocks relative to the amount of feed introduced into the sour
processing stage. It is noted that summing the data points within
each curve shows the same total yield of base stock, which reflects
the fact that the same total amount of hydrocracking conversion was
performed in both types of processing runs. Only the location of
the hydrocracking conversion (all sour, or split between sour and
sweet) was varied.
[0192] The lower pair of curves provides additional information
about the same pair of process runs. As for the upper pair of
curves, the circle data points in the lower pair of curves
represent all hydrocracking in the sour stage and the square data
points correspond to a split of hydrocracking between sour and
sweet stages. The lower pair of curves shows the relationship
between cut point (bottom axis) and the resulting kinematic
viscosity at 100.degree. C. (right axis). As shown by the lower
pair of curves, the three cut point represent formation of a light
neutral base stock (5 or 6 cSt), a heavy neutral base stock (10-12
cSt), and a bright stock (about 30 cSt). The individual data points
for the lower curves also indicate the pour point of the resulting
base stock.
[0193] As shown in FIG. 5, altering the conditions under which
hydrocracking is performed can alter the nature of the resulting
lubricant base stocks. Performing all of the hydrocracking
conversion during the first (sour) hydroprocessing stage can result
in higher viscosity index values for the heavy neutral base stock
and bright stock products, while also producing an increased yield
of heavy neutral base stock. Performing a portion of the
hydrocracking under sweet conditions increased the yield of light
neutral base stock and bright stock with a reduction in heavy
neutral base stock yield. Performing a portion of the hydrocracking
under sweet conditions also reduced the viscosity index values for
the heavy neutral base stock and bright stock products. This
demonstrates that the yield of base stocks and/or the resulting
quality of base stocks can be altered by varying the amount of
conversion performed under sour conditions versus sweet
conditions.
Example 3--Feedstocks and DAOs
[0194] Table 1 shows properties of two types of vacuum resid feeds
that are potentially suitable for deasphalting, referred to in this
example as Resid A and Resid B. Both feeds have an API gravity of
less than 6, a specific gravity of at least 1.0, elevated contents
of sulfur, nitrogen, and metals, and elevated contents of carbon
residue and n-heptane insolubles.
TABLE-US-00001 TABLE 1 Resid Feed Properties Resid (566.degree.
C.+) Resid A Resid B API Gravity (degrees) 5.4 4.4 Specific Gravity
(15.degree. C.) (g/cc) 1.0336 1.0412 Total Sulfur (wt %) 4.56 5.03
Nickel (wppm) 43.7 48.7 Vanadium (wppm) 114 119 TAN (mg KOH/g)
0.314 0.174 Total Nitrogen (wppm) 4760 4370 Basic Nitrogen (wppm)
1210 1370 Carbon Residue (wt %) 24.4 25.8 n-heptane insolubles (wt
%) 7.68 8.83 Wax (Total--DSC) (wt %) 1.4 1.32 KV @ 100.degree. C.
(cSt) 5920 11200 KV @ 135.degree. C. (cSt) 619 988
[0195] The resids shown in Table 1 were used to form deasphalted
oil. Resid A was exposed to propane deasphalting (deasphalted oil
yield <40%) and pentane deasphalting conditions (deasphalted oil
yield .about.65%). Resid B was exposed to butane deasphalting
conditions (deasphalted oil yield .about.75%). Table 2 shows
properties of the resulting deasphalted oils.
TABLE-US-00002 TABLE 2 Examples of Deasphalted Oils C.sub.3 DAO
C.sub.4 DAO C.sub.5 DAO API Gravity (degrees) 22.4 12.9 12.6
Specific Gravity (15.degree. C.) (g/cc) 0.9138 0.9782 0.9808 Total
Sulfur (wt %) 2.01 3.82 3.56 Nickel (wppm) <0.1 5.2 5.3 Vanadium
(wppm) <0.1 15.6 17.4 Total Nitrogen (wppm) 504 2116 1933 Basic
Nitrogen (wppm) 203 <N/A> 478 Carbon Residue (wt %) 1.6 8.3
11.0 KV @ 100.degree. C. (cSt) 33.3 124 172 VI 96 61 <N/A>
SimDist (ASTM D2887) .degree. C. 5 wt % 509 490 527 10 wt % 528 515
546 30 wt % 566 568 588 50 wt % 593 608 619 70 wt % 623 657 664 90
wt % 675 <N/A> <N/A> 95 wt % 701 <N/A>
<N/A>
[0196] As shown in Table 2, the higher severity deasphalting
provided by propane deasphalting results in a different quality of
deasphalted oil than the lower severity C.sub.4 and C.sub.5
deasphalting that was used in this example. It is noted that the
C.sub.3 DAO has a kinematic viscosity @100.degree. C. of less than
35, while the C.sub.4 DAO and C.sub.5 DAO have kinematic
viscosities greater than 100. The C.sub.3 DAO also generally has
properties more similar to a lubricant base stock product, such as
a higher API gravity, a lower metals content/sulfur
content/nitrogen content, lower CCR levels, and/or a higher
viscosity index.
Example 4--Sour Stage Processing Using Bulk Metal Catalyst
[0197] One of the difficulties with processing of feeds based on
deasphalted oils for forming lubricant base stocks is that the
feeds have an increased susceptibility to forming polynuclear
aromatics (PNAs) during processing. The tendency to form PNAs can
increase with the length of exposure to sufficiently severe
hydroprocessing conditions. As a result, during sour stage
processing for removal of contaminants and/or viscosity index
uplift, it can be beneficial to use higher activity catalysts so
that the space velocity in the sour stage can be increased while
still achieving desired properties for the sour stage effluent.
[0198] The impact of using a bulk metal catalyst as part of sour
stage hydroprocessing of a feed was investigated by processing a
feed in a laboratory scale two reactor configuration. The first
reactor included the two commercially available
demetallization/hydrotreating catalyst beds described in Example
13. In various processing runs, the second reactor included three
different combinations of hydrotreating catalyst. One option for
the second reactor catalyst was to use a commercially available
hydrotreating catalyst. In a second option, the commercially
available hydrotreating catalyst was used in conjunction with a
first bulk multimetallic catalyst formed from reactants at least
partially in the solid state, as described above. In a third
option, the commercially available hydrotreating catalyst was used
in conjunction with a second bulk multimetallic catalyst formed
from a precursor including organic components, as described
above.
[0199] Table 3 shows the feed used for the first reactor, and the
resulting first reactor product that was used as a feed for the
second reactor. It is believed that the feed to the first reactor
and the feed to the second reactor is representative of the
feeds/inputs that would be used during formation of a lubricant
base stock from high lift deasphalted oil. During such production,
a sour hydrocracking reactor would be used to further process the
output generated from the second reactor. The raw DAO shown in
Table 14 corresponds to a deasphalted oil formed by C.sub.5
deasphalting.
TABLE-US-00003 TABLE 3 Feed to First and Second Reactors of Sour
Processing Stage Prepared feed to second stage HDT (Optionally
including Raw DAO bulk metal catalyst) Specific gravity at 0.9839
0.9212 15.degree. C. (g/cm.sup.3) H, wt % 10.76 12.73 S, wppm 34600
726 N, wppm 2562 113 Conradson Carbon 12.1 1.22 Residue, wt %
[0200] After processing the raw DAO from Table 3 in the first
reactor to form the feed for hydrotreatment in the second reactor,
the feed to the second reactor was processed in the presence of one
of the three catalyst options. The processing conditions included a
pressure of 2200 psig (.about.15.2 MPag) and a hydrogen treat gas
rate of 8000 SCF/b (.about.1400 Nm.sup.3/m.sup.3). The temperature
and LHSV were varied to provide processing conditions 1-5 shown in
Table 4.
TABLE-US-00004 TABLE 4 Second Reactor Processing Conditions and
Product Properties Condition 1 2 3 Pressure psig 2200 2200 2200 TGR
scf/bbl 8000 8000 8000 Gas Flow sccm 128.2 128.2 128.2 Liq Flow
cc/hr 5.4 5.4 5.4 Temp C. 343 356 371 Temp F. 649.4 672.8 699.8 3
cc supported Sulfur ppm 400 287 144 Nitrogen ppm 78.2 60 34.1
Density g/ml 0.8799 0.8803 0.8765 3 cc supported/ 2 cc bulk cat 1
Sulfur ppm 232 133 45.3 Nitrogen ppm 56 38 15 Density g/ml 0.8787
0.8762 0.8701 3 cc supported/ 2 cc bulk cat 2 Sulfur ppm 157 76 22
Nitrogen ppm 43 24 7 Density g/ml 0.8760 0.8735 0.8647
[0201] As shown in Table 4, the configurations including both the
commercial supported catalyst and a bulk catalyst included more
total catalyst volume than the configuration using just the
commercially available supported catalyst. As a result, the space
velocities are different. As shown in Table 4, both bulk catalysts
provided improved activity relative to using a commercially
available supported catalyst. Although the space velocities are
different in the examples including both bulk and supported
catalyst versus supported catalyst alone, those of skill in the art
will recognize that based on a first order model, it is clear that
the bulk catalysts provide superior activity for sulfur removal.
Additionally, use of bulk catalyst 2 (formed from a precursor
including an organic component) provides a significant activity
advantage over use of bulk catalyst 1.
Example 5--Production of Base Stocks (Including Brightstock) at
High Conversion
[0202] Another series of processing runs were performed using a
C.sub.5 DAO (75 wt % yield) as a feed for lubricant production. The
configuration was similar to FIG. 13. Block processing was used for
the sweet processing stage. The light neutral, heavy neutral, and
brightstock portions were processed under conditions to produce two
levels of conversion relative to 370.degree. C. In a first set of
runs, the combined sour stage and sweet stage conversion was 60 wt
%. In a second set of runs, the combined sour stage and sweet stage
conversion was 82 wt %. It is noted that at high rates of
conversion during a single pass, any portions of a lubricant
product that are recycled could potentially undergo conversion
amounts of greater than 70 wt %, or greater than 75 wt %, or
greater than 80 wt %, such as up to 90 wt % or more.
[0203] Conventionally, conversion of greater than roughly 70 wt %
of a feedstock during lubricant product is believed to lead to
large reductions in viscosity index for resulting lubricant
products. Without being bound by any particular theory, this is
believed to be due in part to conversion of isoparaffins with the
feed at elevated levels of conversion. It has been surprisingly
discovered that feeds derived from high yield deasphalted oils
(such as deasphalting yields of at least 50 wt %) can be undergo
greater than 70 wt % conversion without having substantial
reductions in VI. This is believed to be related to the unusually
high aromatic content of lubricant feeds derived from high yield
deasphalted oils.
[0204] Table 5 shows results from processing the C.sub.5 DAO feed
in this example at conversion amounts of 60 wt % and 82 wt %
(combined conversion across initial sour stage and second sweet
stage) for production during block operation of a light neutral
product, a heavy neutral product, and a brightsock product. As
shown in Table 5, increasing the combined conversion results in
products with comparable (or potentially higher) viscosity index
values, while also generating products with substantially reduced
pour point values.
TABLE-US-00005 TABLE 5 Product properties at varying conversion 82
wt % 60 wt % combined conversion combined conversion (relative to
370.degree. C.) (relative to 370.degree. C.) Light Neutral VI 106
106 Pour Point (.degree. C.) -64 -34 KV @ 100.degree. C. (cSt) 4.9
4.3 Heavy Neutral VI 100.9 100.5 Pour Point (.degree. C.) -48 -34
KV @ 100.degree. C. (cSt) 11.9 12.6 Brightstock VI 109 106.3 Pour
Point (.degree. C.) -32 -20 KV @ 100.degree. C. (cSt) 34.6 43.2
Additional Embodiments
Embodiment 1
[0205] A method for making lubricant base stock, comprising:
performing solvent deasphalting, optionally using a C.sub.4+
solvent, under effective solvent deasphalting conditions on a
feedstock having a T5 boiling point of at least about 370.degree.
C. (or at least about 400.degree. C., or at least about 450.degree.
C., or at least about 500.degree. C.), the effective solvent
deasphalting conditions producing a yield of deasphalted oil of at
least about 50 wt % of the feedstock; hydroprocessing at least a
portion of the deasphalted oil under first effective
hydroprocessing conditions to form a hydroprocessed effluent, the
hydroprocessing comprising exposing the at least a portion of the
deasphalted oil to a mixed metal catalyst under the hydroprocessing
conditions, the at least a portion of the deasphalted oil having an
aromatics content of at least about 50 wt %, 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 the hydroprocessed effluent to form at least a fuels
boiling range fraction, a first fraction having a T.sub.5
distillation point of at least 370.degree. C., and a second
fraction having a T.sub.5 distillation point of at least
370.degree. C., the second fraction having a higher kinematic
viscosity at 100.degree. 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 first catalytically dewaxed effluent
comprising a 370.degree. C.+ portion having a first kinematic
viscosity at 100.degree. C.; and 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
catalytically dewaxed effluent comprising a 370.degree. C.+ portion
having a second kinematic viscosity at 100.degree. C. that is
greater than the first kinematic viscosity at 100.degree. C.,
wherein the second effective hydroprocessing conditions are
different from the third effective hydroprocessing conditions, and
wherein the mixed metal catalyst comprises a sulfided mixed metal
catalyst formed by sulfiding a mixed metal catalyst precursor
composition, the mixed metal catalyst precursor composition being
produced by a) heating a composition comprising at least one metal
from Group 6 of the Periodic Table of the Elements, at least one
metal from Groups 8-10 of the Periodic Table of the Elements, and a
reaction product formed from (i) a first organic compound
containing at least one amine group, and (ii) a second organic
compound separate from said first organic compound and containing
at least one carboxylic acid group to a temperature from about
195.degree. C. to about 260.degree. C. for a time sufficient for
the first and second organic compounds to form a reaction product
in situ that contains an amide moiety, unsaturated carbon atoms not
present in the first or second organic compounds, oxygen atoms not
present in the first or second organic compounds, or a combination
thereof; b) heating a composition comprising one metal from Group 6
of the Periodic Table of the Elements, at least one metal from
Groups 8-10 of the Periodic Table of the Elements, and a reaction
product formed from (iii) a first organic compound containing at
least one amine group and at least 10 carbon atoms or (iv) a second
organic compound containing at least one carboxylic acid group and
at least 10 carbon atoms, but not both (iii) and (iv), wherein the
reaction product contains additional unsaturated carbon atoms,
relative to (iii) the first organic compound or (iv) the second
organic compound, wherein the metals of the catalyst precursor
composition are arranged in a crystal lattice, and wherein the
reaction product is not located within the crystal lattice, to a
temperature from about 195.degree. C. to about 260.degree. C. for a
time sufficient for the first or second organic compounds to form a
reaction product in situ that contains unsaturated carbon atoms not
present in the first or second organic compounds, oxygen atoms not
present in the first or second organic compounds, or a combination
thereof; or c) heating a composition comprising at least one metal
from Group 6 of the Periodic Table of the Elements, at least one
metal from Groups 8-10 of the Periodic Table of the Elements, and a
pre-formed amide formed from (v) a first organic compound
containing at least one amine group, and (vi) a second organic
compound separate from said first organic compound and containing
at least one carboxylic acid group, to form at least one of
additional in situ unsaturated carbon atoms or in situ added oxygen
atoms not present in the first organic compound, the second organic
compound, or both, but not for so long that the pre-formed amide
substantially decomposes, thereby forming a catalyst precursor
containing at least one of in situ formed unsaturated carbon atoms
or in situ added oxygen atoms.
Embodiment 2
[0206] The method of Embodiment 1, wherein the catalyst precursor
composition is treated first with said first organic compound and
second with said second organic compound, or wherein the catalyst
precursor composition is treated first with said second organic
compound and second with said first organic compound, or wherein
the catalyst precursor composition is treated simultaneously with
said first organic compound and with said second organic
compound.
Embodiment 3
[0207] The method of Embodiment 1 or 2, wherein said at least one
metal from Group 6 is Mo, W, or a combination thereof, and wherein
said at least one metal from Groups 8-10 is Co, Ni, or a
combination thereof.
Embodiment 4
[0208] The process of any of Embodiments 1 to 3, wherein the mixed
metal catalyst precursor composition is a bulk metal
hydroprocessing catalyst precursor composition consisting
essentially of the reaction product, an oxide form of the at least
one metal from Group 6, an oxide form of the at least one metal
from Groups 8-10, and optionally about 20 wt % or less of a
binder.
Embodiment 5
[0209] A method for making lubricant base stock, comprising:
performing solvent deasphalting, optionally using a C.sub.4+
solvent, under effective solvent deasphalting conditions on a
feedstock having a T5 boiling point of at least about 370.degree.
C. (or at least about 400.degree. C., or at least about 450.degree.
C., or at least about 500.degree. C.), the effective solvent
deasphalting conditions producing a yield of deasphalted oil of at
least about 50 wt % of the feedstock; hydroprocessing at least a
portion of the deasphalted oil under first effective
hydroprocessing conditions to form a hydroprocessed effluent, the
hydroprocessing comprising exposing the at least a portion of the
deasphalted oil to a bulk multimetallic catalyst under the
hydroprocessing conditions, the at least a portion of the
deasphalted oil having an aromatics content of at least about 50 wt
%, 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 the hydroprocessed effluent to form
at least a fuels boiling range fraction, a first fraction having a
T.sub.5 distillation point of at least 370.degree. C., and a second
fraction having a T.sub.5 distillation point of at least
370.degree. C., the second fraction having a higher kinematic
viscosity at 100.degree. 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 first catalytically dewaxed effluent
comprising a 370.degree. C.+ portion having a first kinematic
viscosity at 100.degree. C.; and 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
catalytically dewaxed effluent comprising a 370.degree. C.+ portion
having a second kinematic viscosity at 100.degree. C. that is
greater than the first kinematic viscosity at 100.degree. C.,
wherein the second effective hydroprocessing conditions are
different from the third effective hydroprocessing conditions, and
wherein the bulk multimetallic catalyst comprises of at least one
Group VIII non-noble metal and at least two Group VIB metals and
wherein the ratio of Group VIB metal to Group VIII non-noble metal
is from about 10:1 to about 1:10.
Embodiment 6
[0210] The method of Embodiment 5, wherein the Group VIII non-noble
metal is selected from Ni and Co and the Group VIB metals are
selected from Mo and W.
Embodiment 7
[0211] The method of Embodiment 5 or 6, wherein the bulk
multimetallic is represented by the formula:
(X).sub.b(Mo).sub.c(W).sub.dO.sub.x, and wherein X is a Group VIII
non-noble metal, and the molar ratio of b:(c+d) is 0.5/1 to
3/1.
Embodiment 8
[0212] The method of any of Embodiments 5 to 7, wherein the molar
ratio of b:(c+d) is 0.75/1 to 1.5/1; or wherein the molar ratio of
c:d is >0.01/1; or a combination thereof.
Embodiment 9
[0213] The method of any of Embodiments 5 to 8 wherein the bulk
multimetallic catalyst is essentially an amorphous material having
a unique X-ray diffraction pattern showing crystalline peaks at
d=2.53 Angstroms and d=1.70 Angstroms; or wherein the bulk
multimetallic catalyst also contains an acid function; or a
combination thereof.
Embodiment 10
[0214] The method of any of the above embodiments, wherein the
second effective hydroprocessing conditions further comprise
hydrocracking conditions and the third effective hydroprocessing
conditions further comprise hydrocracking conditions, the second
effective hydroprocessing conditions and third effective
hydroprocessing conditions being different based on a difference in
at least one of a hydrocracking pressure, a hydrocracking
temperature, a dewaxing pressure, and a dewaxing temperature.
Embodiment 11
[0215] The method of any of the above embodiments, further
comprising at least one of: a) solvent extracting at least a
portion of the second catalytically dewaxed effluent to form a
solvent processed effluent, or b) solvent dewaxing at least a
portion of the second catalytically dewaxed effluent to form a
solvent processed effluent, wherein the solvent processed effluent
comprises a T5 distillation point of at least 482.degree. C., a VI
of at least 80, a pour point of -6.degree. C. or less, and a cloud
point of -2.degree. C. or less (or optionally -5.degree. C. or
less).
Embodiment 12
[0216] The method of any of the above embodiments, wherein the
process further comprises recycling at least a portion of a) the
third fraction, b) the fourth fraction, c) the first catalytically
dewaxed effluent, d) the first fraction, e) the second fraction, or
c) a combination of a plurality of a)-e), as part of i) the at
least a portion of the deasphalted oil, ii) the at least a portion
of the first fraction, iii) the at least a portion of the second
fraction, or iv) a combination of a plurality of i), ii), and
iii).
Embodiment 13
[0217] The method of any of the above embodiments, wherein the
hydroprocessing at least a portion of the first fraction and the
hydroprocessing at least a portion of the second fraction comprises
block operation of a processing system.
Embodiment 14
[0218] The method of any of the above embodiments, wherein at least
one of the second effective hydroprocessing conditions and the
third effective hydroprocessing conditions further comprises
performing aromatic saturation.
Embodiment 15
[0219] The method of any of the above embodiments, wherein the
yield of deasphalted oil is at least 55 wt %, or at least 60 wt %,
or at least 65 wt %, or at least 70 wt %, or at least 75 wt %; or
wherein the deasphalted oil has an aromatics content of at least 55
wt %, or at least 60 wt %, or at least 65 wt %, or at least 70 wt %
based on a weight of the deasphalted oil; or a combination
thereof.
Embodiment 16
[0220] The method of any of the above embodiments, wherein the
C.sub.4+ solvent comprises a C.sub.5+ solvent, a mixture of two or
more C.sub.5 isomers, or a combination thereof.
Embodiment 17
[0221] The method of any of the above embodiments, wherein a
combined conversion of the feedstock across the first effective
hydroprocessing conditions and the second effective hydroprocessing
conditions is at least 70 wt % relative to 370.degree. C., or at
least 75 wt %, or at least 80 wt %, the second catalytically
dewaxed effluent having a viscosity index of at least 90, or at
least 100; or wherein a combined conversion of the feedstock across
the first effective hydroprocessing conditions and the third
effective hydroprocessing conditions is at least 70 wt % relative
to 370.degree. C., or at least 75 wt %, or at least 80 wt %, the
third catalytically dewaxed effluent and/or the fourth fraction
having a viscosity index of at least 90, or at least 100; or a
combination thereof.
Embodiment 18
[0222] The method of any of the above embodiments, wherein
separating the hydroprocessed effluent further comprises forming an
additional fraction having a T.sub.5 distillation point of at least
370.degree. 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.degree. C.+
portion having a kinematic viscosity at 100.degree. C. of 3.5 cSt
or more.
Embodiment 19
[0223] The method of any of the above embodiments, wherein at least
a portion of the first fraction, at least a portion of the second
fraction, at least a portion of the first catalytically dewaxed
effluent, at least a portion of the second catalytically dewaxed
effluent, or a combination thereof is used as a feed for a steam
cracker; or wherein at least a portion of the second catalytically
dewaxed effluent is used as an asphalt blend component.
Embodiment 20
[0224] A system for producing a lubricant boiling range product,
comprising: a solvent deasphalting unit comprising a deasphalting
inlet and a deasphalting outlet; a first hydroprocessing stage
comprising a first hydroprocessing inlet and a first
hydroprocessing outlet, the first hydroprocessing inlet being in
fluid communication with the deasphalting outlet, the first
hydroprocessing stage further comprising a sulfided mixed metal
catalyst, a bulk multimetallic catalyst, or a combination thereof;
a first separation stage comprising a first separation inlet and a
plurality of first separation outlets, the first separation inlet
being in fluid communication with the first stage outlet; a
plurality of storage tanks in fluid communication with the
plurality of first separation outlets; a second hydroprocessing
stage comprising a second hydroprocessing inlet and a second
hydroprocessing outlet, the second hydroprocessing inlet being in
intermittent fluid communication with the plurality of storage
tanks; and a second separation stage comprising a second separation
inlet and a plurality of second separation outlets, the second
separation inlet being in fluid communication with the second
hydroprocessing outlet, wherein a) the deasphalting inlet is in
fluid communication with at least one separation outlet of the
plurality of first separation outlets, b) the deasphalting inlet is
in fluid communication with at least one of the plurality of
storage tanks, c) the deasphalting outlet is in fluid communication
with at least one of the plurality of second separation outlets, or
d) a combination thereof.
Embodiment 21
[0225] The system of Embodiment 20, wherein the system further
comprises a solvent extraction stage in fluid communication with
one or more of the plurality of second separation outlets.
Embodiment 22
[0226] The system of Embodiment 20 or 21, wherein the sulfided
mixed metal catalyst comprises a catalyst formed by sulfiding a
mixed metal catalyst precursor composition, the mixed metal
catalyst precursor composition being produced by a) heating a
composition comprising at least one metal from Group 6 of the
Periodic Table of the Elements, at least one metal from Groups 8-10
of the Periodic Table of the Elements, and a reaction product
formed from (i) a first organic compound containing at least one
amine group, and (ii) a second organic compound separate from said
first organic compound and containing at least one carboxylic acid
group to a temperature from about 195.degree. C. to about
260.degree. C. for a time sufficient for the first and second
organic compounds to form a reaction product in situ that contains
an amide moiety, unsaturated carbon atoms not present in the first
or second organic compounds, oxygen atoms not present in the first
or second organic compounds, or a combination thereof; b) heating a
composition comprising one metal from Group 6 of the Periodic Table
of the Elements, at least one metal from Groups 8-10 of the
Periodic Table of the Elements, and a reaction product formed from
(iii) a first organic compound containing at least one amine group
and at least 10 carbon atoms or (iv) a second organic compound
containing at least one carboxylic acid group and at least 10
carbon atoms, but not both (iii) and (iv), wherein the reaction
product contains additional unsaturated carbon atoms, relative to
(iii) the first organic compound or (iv) the second organic
compound, wherein the metals of the catalyst precursor composition
are arranged in a crystal lattice, and wherein the reaction product
is not located within the crystal lattice, to a temperature from
about 195.degree. C. to about 260.degree. C. for a time sufficient
for the first or second organic compounds to form a reaction
product in situ that contains unsaturated carbon atoms not present
in the first or second organic compounds, oxygen atoms not present
in the first or second organic compounds, or a combination thereof;
or c) heating a composition comprising at least one metal from
Group 6 of the Periodic Table of the Elements, at least one metal
from Groups 8-10 of the Periodic Table of the Elements, and a
pre-formed amide formed from (v) a first organic compound
containing at least one amine group, and (vi) a second organic
compound separate from said first organic compound and containing
at least one carboxylic acid group, to form at least one of
additional in situ unsaturated carbon atoms or in situ added oxygen
atoms not present in the first organic compound, the second organic
compound, or both, but not for so long that the pre-formed amide
substantially decomposes, thereby forming a catalyst precursor
containing at least one of in situ formed unsaturated carbon atoms
or in situ added oxygen atoms.
Embodiment 23
[0227] The system of Embodiment 20 or 21, wherein the bulk
multimetallic catalyst comprises of at least one Group VIII
non-noble metal and at least two Group VIB metals and wherein the
ratio of Group VIB metal to Group VIII non-noble metal is from
about 10:1 to about 1:10.
[0228] When numerical lower limits and numerical upper limits are
listed herein, ranges from any lower limit to any upper limit are
contemplated. While the illustrative embodiments of the invention
have been described with particularity, it will be understood that
various other modifications will be apparent to and can be readily
made by those skilled in the art without departing from the spirit
and scope of the invention. Accordingly, it is not intended that
the scope of the claims appended hereto be limited to the examples
and descriptions set forth herein but rather that the claims be
construed as encompassing all the features of patentable novelty
which reside in the present invention, including all features which
would be treated as equivalents thereof by those skilled in the art
to which the invention pertains.
[0229] The present invention has been described above with
reference to numerous embodiments and specific examples. Many
variations will suggest themselves to those skilled in this art in
light of the above detailed description. All such obvious
variations are within the full intended scope of the appended
claims.
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