U.S. patent application number 12/481903 was filed with the patent office on 2010-04-01 for method for predicting a property of a base oil.
This patent application is currently assigned to Chevron U.S.A. Inc.. Invention is credited to Scott C. Deskin, Kathy A. Helling, Brent K. Lok, John M. Rosenbaum, Ryan J. Schexnaydre.
Application Number | 20100077842 12/481903 |
Document ID | / |
Family ID | 42055981 |
Filed Date | 2010-04-01 |
United States Patent
Application |
20100077842 |
Kind Code |
A1 |
Rosenbaum; John M. ; et
al. |
April 1, 2010 |
METHOD FOR PREDICTING A PROPERTY OF A BASE OIL
Abstract
A method for predicting a property of a base oil, and a blend
chart, are provided. The method for predicting a property of a base
oil includes selecting two base stocks, and preparing a chart
having the viscometric property under low temperature and the
volatility of both base stocks and curves between them that is used
to predict whether blends of two base stocks will meet requirements
for a finished lubricant.
Inventors: |
Rosenbaum; John M.;
(Richmond, CA) ; Lok; Brent K.; (San Francisco,
CA) ; Helling; Kathy A.; (Santa Rosa, CA) ;
Schexnaydre; Ryan J.; (Richmond, CA) ; Deskin; Scott
C.; (Alameda, CA) |
Correspondence
Address: |
CHEVRON CORPORATION
P.O. BOX 6006
SAN RAMON
CA
94583-0806
US
|
Assignee: |
Chevron U.S.A. Inc.
|
Family ID: |
42055981 |
Appl. No.: |
12/481903 |
Filed: |
June 10, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61101674 |
Oct 1, 2008 |
|
|
|
Current U.S.
Class: |
73/54.01 |
Current CPC
Class: |
G01N 11/00 20130101;
G01N 33/26 20130101 |
Class at
Publication: |
73/54.01 |
International
Class: |
G01N 11/00 20060101
G01N011/00 |
Claims
1. A method for predicting a property of a base oil, comprising: a.
selecting a first base stock and a second base stock; b. preparing
a chart having: i. a first point with a first viscometric property
under low temperature and a first volatility of the first base
stock; ii. a second point with a second viscometric property under
low temperature and a second volatility of the second base stock;
c. blending the first base stock and the second base stock in
varying proportions to construct a curve between the first point
and the second point on the chart; wherein the curve predicts
whether a base oil that is a blend of the first base stock and the
second base stock will meet base oil requirements for a finished
lubricant; d. if the curve falls below a point representing the
base oil requirements for the finished lubricant, then the base oil
blend of the first base stock and the second base stock are capable
of making the finished lubricant; e. if the curve falls above the
point representing the base oil requirements for the finished
lubricant, then the correct type of a trim stock is ascertained by
a direction and a distance one would need to shift the curve.
2. The method of claim 1, wherein the finished lubricant is a
multigrade engine oil.
3. The method of claim 2, wherein the multigrade engine oil is a
5W-XX grade, a 10W-XX grade, or a 15W-XX grade, wherein XX is
selected from the group consisting of 20, 30, 40, 50, and 60.
4. The method of claim 2, wherein the multigrade engine oil meets
an engine oil specification selected from the group of API CJ-4,
ACEA E9, or a combination thereof.
5. The method of claim 1, wherein the first viscometric property
under low temperature and the second viscometric property under low
temperature are CCS VIS at -25.degree. C.
6. The method of claim 1, wherein the first volatility and the
second volatility are Noack volatility.
7. The method of claim 1, wherein the first base stock and the
second base stock are petroleum derived.
8. The method of claim 1, wherein the first base stock and the
second base stock are Group II or Group III.
9. The method of claim 1, wherein the trim stock is a Group II, a
Group III or a Group IV.
10. The method of claim 1, wherein the first base stock, the second
base stock, and the trim stock are Group II.
11. A blend chart, comprising: a. a first point defined by a first
viscometric property and a first volatility of a first base stock:
b. a second point defined by a second viscometric property and a
second second volatility of a second base stock; c. a curve drawn
between the first point and the second point that predicts a third
viscometric property and a third volatility of one or more blends
of the first base stock and the second base stock; and d. one or
more target ranges enclosing desired values of a fourth viscometric
property and a fourth volatility that are required to meet a
specification for a finished lubricant; wherein the position of the
curve relative to the one or more target ranges predicts whether a
blend of the first base stock and the second base stock will meet
the specification for the finished lubricant.
12. The blend chart of claim 11, additionally comprising one or
more additional points defined by an additional viscometric
property and an additional volatility of one or more other base
stocks; and a position of one or more of the additional points
instructs a user of the chart how much of the one or more other
base stocks may be blended with the blend of the first base stock
and the second base stock to meet the specification for the
finished lubricant.
13. The blend chart of claim 11, wherein the first, second, third,
and fourth viscometric properties are CCS VIS.
14. The blend chart of claim 13, wherein the CCS VIS is measured at
-25.degree. C.
15. The blend chart of claim 11, wherein the first, second, third,
and fourth volatilities are Noack volatility.
16. The blend chart of claim 11, wherein the finished lubricant is
an engine oil.
17. The blend chart of claim 11, wherein the one or more target
ranges enclose desired values of CCS VIS and Noack volatility for
one or more multigrade engine oils selected from the group of 5W-XX
grade, 10W-XX grade, 15W-XX grade, and combinations thereof.
18. The blend chart of claim 17, wherein the CCS VIS is measured at
-25.degree. C.
19. The blend chart of claim 11, wherein the target range is a
point.
20. The blend chart of claim 12, additionally comprising a second
curve between the first point and the additional point and a third
curve between the additional point and the second point; wherein
the three curves enclose a ternary blending space; and wherein the
one or more target ranges fall within the ternary blending space.
Description
[0001] This application claims the benefit of provisional
Application No. 61/101,674, filed Oct. 1, 2008, herein incorporated
in its entirety.
[0002] This application is related to co-filed patent applications
titled "A 110 Neutral Base Oil with Improved Properties", "A
Process to Make a 110 Neutral Base Oil with Improved Properties",
"A 170 Neutral Base Oil with Improved Properties", and "A Process
to Manufacture a Base Stock and a Base Oil Manufacturing Plant";
herein incorporated in their entirety.
FIELD OF THE INVENTION
[0003] This invention is directed to a method for predicting a
property of a base oil and to a blend chart.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 illustrates a blend chart having curves defining the
typical relationship between CCS VIS @-25.degree. C. and Noack
volatility of blends of Chevron 100R with Chevron 220R, Chevron
110RLV and Chevron 220R, Chevron 5R and Chevron 220R, Chevron 4R
and Chevron 220R, and Chevron 110 RLV and Chevron 7R. The circle to
the left encompasses the target range of CCS VIS and Noack
volatility needed for 5W multigrade engine oils. The circle in the
center encompasses the target range of CCS VIS and Noack volatility
needed for 10W multigrade engine oils. The circle to the right
encompasses the target range of CCS VIS and Noack volatility needed
for 15W multigrade engine oils.
[0005] Chevron 110RLV is a new base oil with improved properties.
Chevron 100R, 150R, and Chevron 220R are commercial Group II base
oils. Chevron 4R, 5R, and 7R are commercial highly paraffinic
unconventional base oils. Chevron 4R and Chevron 7R are Group III
base oils, and Chevron 5R is a Group II base oil.
[0006] FIG. 2 illustrates a blend chart having a first point
defined by the CCS VIS and Noack volatility of Chevron 100R. The
blend chart has a second point defined by the CCS VIS and Noack
volatility of Chevron 7R. The blend chart has a third point defined
by the CCS VIS and Noack volatility of Chevron 220R. Curves are
drawn between the three points. A target point of a CCS VIS of 3342
and a Noack volatility of 11.73 is placed on the chart. The chart
instructs a user how much of each of the three base oils may be
blended to meet the target point properties.
DETAILED DESCRIPTION OF THE INVENTION
Definitions
[0007] The term "comprising" means including the elements or steps
that are identified following that term, but any such elements or
steps are not exhaustive, and an embodiment may include other
elements or steps.
[0008] "Consecutive numbers of carbon atoms" means that the base
oil has a distribution of hydrocarbon molecules over a range of
carbon numbers, with every number of carbon numbers in-between. For
example, the base oil may have hydrocarbon molecules ranging from
C22 to C36 or from C30 to C60 with every carbon number in-between.
The hydrocarbon molecules of the base oil differ from each other by
consecutive numbers of carbon atoms, as a consequence of the waxy
feed used to make the base oil also having consecutive numbers of
carbon atoms. For example, in the Fischer-Tropsch hydrocarbon
synthesis reaction, the source of carbon atoms is CO and the
hydrocarbon molecules are built up one carbon atom at a time.
Petroleum-derived waxy feeds have consecutive numbers of carbon
atoms. In contrast to an oil based on polyalphaolefin, the
molecules of a base oil made from a waxy feed and having
consecutive numbers of carbon atoms have a more linear structure,
comprising a relatively long backbone with short branches. The
classic textbook description of a polyalphaolefin is a star-shaped
molecule, and in particular tridecane, which is illustrated as
three decane molecules attached at a central point. While a
star-shaped molecule is theoretical, nevertheless polyalphaolefin
molecules have fewer and longer branches that the hydrocarbon
molecules that make up the base oil disclosed herein.
[0009] A "base stock" is a lubricant component that is produced by
a single manufacturer to the same specifications (independent of
feed source or manufacturer's location): that meets the same
manufacturer's specification; and that is identified by a unique
formula, product identification number, or both. Base stocks may be
manufactured using a variety of different processes including but
not limited to distillation, solvent refining, hydrogen processing,
oligomerization, esterification, and rerefining.
[0010] A "base oil" is a base stock or blend of different base
stocks. It is suitable for blending with additives into finished
lubricants meeting desired specifications.
[0011] A "base stock slate" is a product line of base stocks that
have different viscosities but are in the same base stock grouping
and from the same manufacturer.
[0012] A "light neutral base oil" has a boiling range of
approximately 650.degree. F. to 900.degree. F. (343.degree. C. to
482.degree. C.), a pour point not greater than about -5.degree. C.,
and a kinematic viscosity at 100.degree. C. of about 4 to about 5
mm.sup.2/s.
[0013] A "highly paraffinic unconventional base oil" is a Group II
or Group III base oil having greater than 72% paraffinic carbon and
less than 30% naphthenic carbon by n-d-M analysis.
[0014] N-d-M analysis is done by ASTM D3238-95 (Reapproved 2005)
with normalization. ASTM D3238-95 (Reapproved 2005) is the Standard
Test Method for Calculation of Carbon Distribution and Structural
Group Analysis of Petroleum Oils by the n-d-M Method. This method
is for "olefin free" feedstocks which are assumed in this
application to mean that that olefin content is 2 wt % or less. The
normalization process consists of the following: A) If the Ca value
is less than zero, Ca is set to zero, and Cn and Cp are increased
proportionally so that the sum is 100%. B) If the Cn value is less
than zero, Cn is set to zero, and Ca and Cp are increased
proportionally so that the sum is 100%; and C) If both Cn and Ca
are less than zero, Cn and Ca are set to zero, and Cp is set to
100%.
Test Method Descriptions:
[0015] "Boiling range" is the 5 wt % boiling point to the 95 wt %,
inclusive of the end points, as measured by ASTM D 6352-04 and
referred to herein as SimDist. A hydrocarbon with a boiling range
of 700 to 900.degree. F., for example has a 5 wt % boiling point
greater than 700.degree. F. and a 95 wt % boiling point less than
900.degree. F.
[0016] "Kinematic viscosity" is a measurement in mm.sup.2/s of the
resistance to flow of a fluid under gravity, determined by ASTM
D445-06.
[0017] "Viscosity index" (VI) is an empirical, unit-less number
indicating the effect of temperature change on the kinematic
viscosity of the oil. The higher the VI of an oil, the lower its
tendency to change viscosity with temperature. VI is measured
according to ASTM D 2270-04.
[0018] "Cold-cranking simulator apparent viscosity" (CCS VIS) is a
measurement in millipascal seconds, mPas, to measure the
viscometric properties of lubricating base oils under low
temperature and low shear. CCS VIS is determined by ASTM D 5293-04.
CCS VIS may be measured at different temperatures, such as -25 C or
-35 C.
[0019] "Noack volatility" is defined as the mass of oil, expressed
in weight %, which is lost when the oil is heated at 250.degree. C.
with a constant flow of air drawn through it for 60 minutes,
measured according to ASTM D5800-05, Procedure B.
[0020] "Pour point" is a measurement of the temperature at which a
sample of base oil will begin to flow under certain carefully
controlled conditions, which can be determined as described in ASTM
D 5950-02.
[0021] "Flash point" is a measure of the tendency of the base oil
to form a flammable mixture with air under controlled laboratory
conditions. It is measured using a Cleveland open cup apparatus
(manual or automated), by ASTM D 92-05a.
[0022] "Oxidator BN" measures the response of a base oil in a
simulated application. High values, or long times to adsorb one
liter of oxygen, indicate good stability. Oxidator BN can be
measured via a Dornte-type oxygen absorption apparatus (R. W. Domte
"Oxidation of White Oils," Industrial and Engineering Chemistry,
Vol. 28, page 26, 1936), under 1 atmosphere of pure oxygen at
340.degree. F. The time, in hours, to absorb 1000 ml of O.sub.2 by
100 grams of oil is reported. In the Oxidator BN test, 0.8 ml of
catalyst is used per 100 grams of oil. The catalyst is a mixture of
soluble metal-naphthenates simulating the average metal analysis of
used crankcase oil. The additive package is 80 millimoles of zinc
bispolypropylenephenyldithiophosphate per 100 grams of oil.
[0023] "Weight percent aromatics" gives an indication of the UV and
oxidation stability of a base oil. It can be measured by HPLC-UV.
In one embodiment, the test is conducted using a Hewlett Packard
1050 Series Quaternary Gradient High Performance Liquid
Chromatography (HPLC) system, coupled with a HP 1050 Diode Array
UV-Vis detector interfaced to an HP Chem-station. Identification of
the individual aromatic classes in the base oil can be made on the
basis of the UV spectral pattern and the elution time. The amino
column used for this analysis differentiates aromatic molecules
largely on the basis of their ring-number (or double-bond number).
Thus, the single ring aromatic containing molecules elute first,
followed by the polycyclic aromatics in order of increasing double
bond number per molecule. For aromatics with similar double bond
character, those with only alkyl substitution on the ring elute
sooner than those with naphthenic substitution. Unequivocal
identification of the various base oil aromatic hydrocarbons from
their UV absorbance spectra can be accomplished recognizing that
their peak electronic transitions are all red-shifted relative to
the pure model compound analogs to a degree dependent on the amount
of alkyl and naphthenic substitution on the ring system.
Quantification of the eluting aromatic compounds can be made by
integrating chromatograms made from wavelengths optimized for each
general class of compounds over the appropriate retention time
window for that aromatic. Retention time window limits for each
aromatic class can be determined by manually evaluating the
individual absorbance spectra of eluting compounds at different
times and assigning them to the appropriate aromatic class based on
their qualitative similarity to model compound absorption
spectra.
Base Oil
[0024] We have developed an improved base oil comprising
hydrocarbons with consecutive numbers of carbon atoms. In one
embodiment, the base oil has a boiling range from 700 to
925.degree. F. (371 to 496.degree. C.), a VI from 105 to 115, and a
Noack volatility less than 18 wt %.
[0025] In a second embodiment, the base oil has a boiling range
from 700 to 925.degree. F. (371 to 496.degree. C.), a VI from 105
to 115, and a CCS VIS at -25.degree. C. less than 1500 mPas.
[0026] In a third embodiment, the base oil has a boiling range from
700 to 925.degree. F. (371 to 496.degree. C.), a CCS VIS at
-25.degree. C. of at least 1100 mPas, and a ratio of Noack
volatility to CCS VIS at -25.degree. C. multiplied by 100 from 0.80
to 1.55.
[0027] The base oil has a VI that is less than 120, such that the
base oil falls with the VI range of a Group II base oil. In some
embodiments the VI is from 105 to 115, such as from 107 to 115, 107
to 113, 109 to 114, or 110 to 115.
[0028] The base oil has a low Noack volatility, generally less than
25 wt % or less than 20 wt %. In some embodiments the Noack
volatility is less than 18 wt %, less than 17 wt %, or less than
16.5 wt %.
[0029] In one embodiment the base oil has an Oxidator BN that is
greater than 18, 20, 22, or 24 hours. In some embodiments the
Oxidator BN of the base oil is higher than the original Oxidator BN
of an original base oil from which the base oil is made.
[0030] In one embodiment the base oil has a high flash point, such
as greater than 210.degree. C., greater than 215.degree. C., or
greater than 220.degree. C. Generally, the base oil has a flash
point less than 275.degree. C.
[0031] In one embodiment the base oil has a low wt % total
aromatics, such as less than 0.20 wt %, less than 0.10 wt %, or
less than 0.05 wt %.
[0032] One feature of the base oil is that it can be blended into a
wide variety of high quality finished lubricants by blending the
base oil with one or more additives. Examples of finished
lubricants that can be made from the base oil include engine oils,
greases, heavy duty motor oils, passenger car motor oils,
transmission and torque fluids, natural gas engine oils, marine
lubricants, railroad lubricants, aviation lubricants, food
processing lubricants, paper and forest products, metalworking
fluids, gear lubricants, compressor lubricants, turbine oils,
hydraulic oils, heat transfer oils, barrier fluids, and other
industrial products. In one embodiment the base oil can be blended
into a multigrade engine oil. Examples of multigrade engine oils
that can be blended with the base oil are 5W-XX, 10W-XX, and
15W-XX, wherein XX is selected from the group consisting of 20, 30,
40, 50, and 60.
[0033] The base oil may additionally comprise a second base oil. In
one embodiment the second base oil is a Group II base oil. Group
II, Group III, and Group IV base oils are defined in Appendix E of
the API 1509 specification, April 2008. A Group II base oil has
greater than or equal to 90 percent saturates and less than or
equal to 0.03 percent sulfur and has a VI greater than or equal to
80 and less than 120. A Group III base oil has greater than or
equal to 90 percent saturates and less than or equal to 0.03
percent sulfur and has a VI greater than or equal to 120. A Group
IV base oil is a polyalphaolefin. The second base oil, for example
can be one having a kinematic viscosity at 40.degree. C. from 40.00
to 46.00, such as a 220 neutral. In some embodiments the base oil
additionally comprises a second base oil. In one embodiment the
base oil contains less than 20 wt %, less than 10 wt % Group III or
Group IV base oil, less than 5 wt % Group III or Group IV base oil,
or no Group III or Group IV base oil. In another embodiment the
base oil contains less than 20 wt %, less than 10 wt %, or no
highly paraffinic unconventional base oil. One example of a base
oil that can be made without any Group III or Group IV base oil, is
base oil having a kinematic viscosity at 40.degree. C. from 28.00
to 32.00 mm.sup.2/s. This base oil could be referred to as a 150
neutral base oil. This 150 neutral base oil has perfect properties
for blending with additives, and even with no other base oils, into
engine oils. It can be blended into 10W engine oils that meet
modern specifications, including low Noack volatility. Examples of
modern specifications that these engine oils can meet are the ACEA
2007 limits for A3/B3, A3/B4, and A5/B5 for gasoline and diesel
engine oils.
[0034] In one embodiment the base oil can be blended into a 5W
grade, a 10W grade, and a 15W grade engine oil without a high
amount of Group III or Group IV base oil in the blend. In another
embodiment the base oil can be blended into a 5W grade, a 10W
grade, and a 15W grade without a high amount of highly paraffinic
unconventional base oil. Group III, Group IV, and highly paraffinic
unconventional base oils are often considerably more expensive than
other Group II base oils. In another embodiment, the 5W, 10W and
15W grades are all multigrade engine oils. In the context of this
disclosure, a high amount of Group III or Group IV base oil is
considered to be greater than 20 wt %, or in some embodiments a
high amount can be greater than 10 wt %. In one embodiment the base
oil can be blended into a 5W grade, a 10W grade, and a 15W grade
engine oil without any Group III or Group IV base oil in the blend.
In another embodiment the base oil can be blended into a 5W grade,
a 10W grade, and a 15W grade engine oil without any highly
paraffinic unconventional base oil. 5W, 10W, and 15W grades and
multigrade 5W-XX, 10W-XX, and 15W-XX engine oil viscosities are
defined by the SAE J300 specification, published Nov. 1, 2007.
Process to Manufacture Base Oil
[0035] We provide a process to manufacture a base oil, comprising
selecting an original base oil having an original VI from 95 to
115, an original Noack volatility from 20 to 30 wt %, and an
original CCS VIS at -25.degree. C. from 1100 to 1500 mPas. We
remove a lower boiling fraction from the original base oil, whereby
a base oil is made having a kinematic viscosity at 100.degree. C.
from 4.2 to 4.6 mm.sup.2/s, a VI that is at least 4 higher than the
original VI, a Noack volatility that is at least 3 wt % lower than
the original Noack volatility, and a CCS VIS at -25.degree. C. that
is within 200 mPas of the original CCS VIS at -25.degree. C.
[0036] In one embodiment, the base oil has a ratio of Noack
volatility to CCS VIS at -25.degree. C. multiplied by 100 within a
desired range. The desired range may be from 0.80 to 1.55, from
0.90 to 1.40, from 0.90 to 1.30, or from 1.0 to 1.30.
[0037] In one embodiment, the original base oil has an original
kinematic viscosity at 100.degree. C. from 3.75 to 4.45 mm.sup.2/s.
When the lower boiling fraction is removed this raises the
kinematic viscosity of the base oil. In one embodiment the base oil
has a kinematic viscosity at 100.degree. C. from 4.05 to 4.75
mm.sup.2/s.
[0038] In one embodiment the lower boiling fraction is all of the
hydrocarbons in the original base oil boiling below a certain
temperature, such as for example 625.degree. F., 650.degree. F.,
655.degree. F., or 660.degree. F. The lower boiling fraction is
removed by carefully controlled vacuum distillation having a tower
top temperature, a tower bottom temperature, a tower top pressure
and a tower bottom pressure that are selected to remove all of the
hydrocarbons in the original base oil boiling below the certain
temperature. Various different types of vacuum distillation control
systems may be employed, such as those taught in U.S. Pat. Nos.
3,365,386, 4,617,092, or 4,894,145; in order to provide the highest
yields of desired fractions and exact cut points.
[0039] In one embodiment the VI of the base oil is at least 5
higher than the original VI of the original base oil. For example,
in this embodiment if the original VI is 105, the VI of the base
oil is at least 110. The VI of the base oil is less than 120, such
that the base oil is a Group II base oil. In one embodiment, the
base oil has a VI from 105 to 119, or 105 to 115.
[0040] The Noack volatility of the base oil is at least 3 wt %
lower, and up to 20 wt % lower, than the original Noack volatility
of the original base oil. In one embodiment the Noack volatility of
the base oil is at least 5 wt % lower than the original Noack
volatility. In another embodiment the base oil has a Noack
volatility less than 18 wt %.
[0041] The CCS VIS at -25.degree. C. of the base oil is within 200
mPas of the original CCS VIS at -25.degree. C. In one embodiment
the CCS VIS at -25.degree. C. of the base oil is within 175, 150,
or 125 mPas of the original CCS VIS at -25.degree. C. In one
embodiment the base oil has a CCS VIS at -25.degree. C. less than
1500 mPas.
[0042] In another embodiment the base oil has a CCS VIS at
-25.degree. C. greater than 1100 mPas.
[0043] In one embodiment the base oil has a boiling range from 700
to 925.degree. F. (371 to 496.degree. C.).
[0044] In one embodiment the base oil is made by a process
including the additional step of hydrocracking a heavy hydrocarbon
feedstock in a hydrocracking zone to obtain a greater amount of the
original base oil. The heavy hydrocarbon feedstock has hydrocarbon
molecules with a carbon number of C20+, and has a 5 wt % boiling
point greater than 600.degree. F. (316.degree. C.). Suitable
examples of heavy hydrocarbon feedstocks include vacuum gas oil,
deoiled vacuum gas oil, slack wax, Fischer-Tropsch derived waxy
feed, petroleum wax, high pour point polyalphaolefin, foots oil,
normal alpha olefin wax, deoiled wax, microcrystalline wax, and
mixtures thereof.
[0045] Hydrocracking
[0046] In one embodiment the operating conditions in the
hydrocracking zone are those typical of commercial hydrocracking
operations. In another embodiment the operating conditions in the
hydrocracking zone are selected to convert a heavy hydrocarbon
feedstock to a product slate containing greater than 20 wt %,
greater than 25 wt %, or greater than 30 wt % of a waxy
intermediate fraction which is upgraded to the original base oil.
In different embodiments the operating conditions in the
hydrocracking zone can be selected to convert a heavy hydrocarbon
feedstock to a product slate containing from greater than 20 wt %,
from greater than 25 wt %, from greater than 30 wt %, from greater
than 32 wt %, or from greater than 34 wt % of a waxy intermediate
fraction. In different embodiments the operating conditions in the
hydrocracking zone can be selected to convert a heavy hydrocarbon
feedstock to a product slate containing less than 60 wt %, less
than 50 wt %, less than 40 wt %, or less than 35 wt % of a waxy
intermediate fraction. In one embodiment the operating conditions
in the hydrocracking zone are selected to convert a heavy
hydrocarbon feedstock to a product slate containing from greater
than 30 wt % to less than 40 wt % of a waxy intermediate.
[0047] The original base oil has an original VI from 95 to 115, an
original Noack volatility from 20 to 30 wt %, and an original CCS
VIS at -25.degree. C. from 1100 to 1500 mPas. The temperature in
the hydrocracking zone will be within the range of from about
500.degree. F. (260.degree. C.) to about 900.degree. F.
(480.degree. C.), such as within the range of from about
650.degree. F. (345.degree. C.) to about 800.degree. F.
(425.degree. C.). A total pressure above 1000 psig is used. For
example the total pressure can be above about 1500 psig, or above
about 2000 psig. Although greater maximum pressures have been
reported in the literature and may be operable, the maximum
practical total pressure generally will not exceed about 3000 psig.
In some embodiments, more severe hydrocracking conditions such as
higher temperature or pressure will result in producing an original
base oil product with a higher viscosity index.
[0048] Liquid hourly space velocity (LHSV) will usually fall within
the range of from about 0.2 to about 5.0, such as from about 0.5 to
about 1.5. The supply of hydrogen (both make-up and recycle) is
preferably in excess of the stoichiometric amount needed to crack
the target molecules and will usually fall within the range of from
about 500 to about 20,000 standard cubic feet (SCF) per barrel. In
one embodiment the hydrogen will be within the range from about
2000 to about 10,000 SCF per barrel.
[0049] The catalysts used in the hydrocracking zone are composed of
natural and synthetic materials having hydrogenation and
dehydrogenation activity. These catalysts are well known in the art
and are pre-selected to crack the target molecules and produce the
desired product slate. The hydrocracking catalyst is selected to
convert a heavy hydrocarbon feedstock to a product slate containing
a commercially significant amount of a waxy intermediate fraction
which will be upgraded to the original base oil. Exemplary
commercial cracking catalysts generally contain a support
consisting of alumina, silica, silica-alumina composites,
silica-alumina-zirconia composites, silica-alumina-titania
composites, acid treated clays, crystalline aluminosilicate
zeolitic molecular sieves, such as zeolite A, faujasite, zeolite X,
zeolite Y, and various combinations of the above. The
hydrogenation/dehydrogenation components generally consist of a
metal or metal compound of Group VIII or Group VIB of the periodic
table of the elements. Metals and their compounds such as, for
example, cobalt, nickel, molybdenum, tungsten, platinum, palladium
and combinations thereof are known hydrogenation components of
hydrocracking catalysts.
[0050] In one embodiment, the upgrading of the waxy intermediate
fraction includes the steps of hydroisomerization dewaxing in an
isomerization reactor and hydrofinishing in a hydrofinishing
reactor. Hydroisomerization dewaxing and hydrofinishing are well
known in the art. One example of a suitable upgrading process is
described in U.S. Pat. No. 6,337,010, where the isomerization of
the waxy intermediate feedstock is carried out at a lower total
pressure than the hydrocracking operation.
Base Oil by Process
[0051] We provide a base oil having a kinematic viscosity at
100.degree. C. from 4.2 to 4.6 mm.sup.2/s, a VI from 105 to 115,
and a Noack volatility less than 18 wt % by a process comprising
selecting an original base oil and removing a lower boiling
fraction. The original base oil has an original VI from 95 to 115,
an original Noack volatility from 20 to 30 wt %, and an original
CCS VIS at -25.degree. C. from 1000 to 1500 mPas. The base oil
properties and processes are the same as described earlier. For
example, the original base oil may optionally be made by
hydrocracking a heavy hydrocarbon feedstock in a hydrocracking
zone, wherein the operating conditions in the hydrocracking zone
are selected to convert the heavy hydrocarbon feedstock to a
product slate containing greater than 20 wt %, greater than 25 wt
%, or greater than 30 wt % of a waxy intermediate fraction which is
upgraded to the original base oil. In another embodiment, the base
oil can have a ratio of Noack volatility to CCS VIS at -25.degree.
C. multiplied by 100 from 0.80 to 1.55, from 0.90 to 1.45, or from
0.95 to 1.35.
[0052] In one embodiment, the removing is done by selecting a
distillation cut point that produces a yield of the base oil that
corresponds to a target yield based on a commercial demand for a
light neutral base oil. The higher the distillation cut point the
lower the yield of light neutral base oil that is produced. This
can be an advantage when commercial demand for light neutral base
oil is low, yet demand for higher quality base oil is increasing,
as it leads to overall better base oil plant profitability. As
commercial demand for light neutral base oil changes, the
distillation cut point can be selected to meet a new target
yield.
[0053] In another embodiment, the operating conditions in the
hydrocracking zone can also be selected to produce a yield of the
base oil that corresponds to the target yield based on commercial
demand for light neutral. More severe hydrocracking raises the VI
of the waxy intermediate fraction, while cracking more of the waxy
intermediate fraction into lower boiling hydrocarbons (some of
which will be subsequently distilled out of the original base oil
that is produced).
A Method for Predicting a Property of a Base Oil
[0054] We provide a method for predicting a property of a base oil
that comprises selecting a first base stock and a second base
stock. A chart is prepared having a first point that is a first
viscometric property under low temperature and a first volatility
of the first base stock. The chart also has a second point that is
a second viscometric property under low temperature and a second
volatility of the second base stock. The first base stock and the
second base stock are blended in varying proportions to construct a
curve between the first point and the second point on the chart.
The curve predicts whether a base oil that is a blend of the first
base stock and the second base stock will meet base oil
requirements for a finished lubricant. If the curve falls below a
point representing the base oil requirements for the finished
lubricants, then the base oil blend of the first base stock and the
second base stock are capable of making the finished lubricant. If
the curve falls above the point representing the base oil
requirements for the finished lubricant, then the correct type of a
trim stock is ascertained by a direction and a distance one would
need to shift the curve.
[0055] In this disclosure the position of the curve as being either
`above` or `below` is relative to how the chart is drawn. For this
description, it is assumed that the chart is drawn with the y-axis
having the volatility from low to high as one moves away from the
origin of the chart. It is also assumed that the chart is drawn
with the x-axis having the viscometric property charted from low to
high as one moves away from the origin of the chart. If the chart
is drawn with the y-axis having the volatility from high to low as
one moves away from the origin of the chart and with the
viscometric property from high to low as one moves away from the
origin, then the position of the curve being `above` in fact means
that the curve is on the upper value side for the volatility and
the viscometric property rather than visually on the upper side in
the chart. If the chart is drawn with the y-axis having the
volatility from high to low as one moves away from the origin of
the chart and with the viscometric property from high to low as one
moves away from the origin of the chart, then the position of the
curve being `below` in fact means that the curve is on the lower
value side for the volatility and the viscometric property rather
than visually on the lower side in the chart.
[0056] In one embodiment the finished lubricant is an engine oil.
In some embodiments the finished lubricant is a multigrade engine
oil, such as 5W-XX, 10W-XX, or 15W-XX, where XX is selected from
the group consisting of 20, 30, 40, 50, and 60.
[0057] In one embodiment the first and second viscometric
properties under low temperature are CCS VIS at -25.degree. C. In
another embodiment the first volatility and the second volatility
are Noack volatility.
[0058] In one embodiment the curve falls above the point
representing the base oil requirements for the finished lubricant,
and a trim stock is needed to shift the curve below the point. The
trim stock is a base oil that has properties that bring the curve
in the correct direction. For example, the trim stock may be a
Group II, a Group III, or a Group IV base oil; as long as it has
desired properties that bring the curve in the correct direction.
Generally, less of the trim stock is needed the closer the curve is
to the point representing the base oil requirements for the
finished lubricant.
[0059] In one embodiment, the first base stock, the second base
stock, and the trim stock are all Group II. There can be advantages
to using all Group II for reducing formulation costs and for
simplifying engine oil qualifications.
[0060] For the purposes of this specification and appended claims,
unless otherwise indicated, all numbers expressing quantities,
percentages or proportions, and other numerical values used in the
specification and claims, are to be understood as being modified in
all instances by the term "about." Furthermore, all ranges
disclosed herein are inclusive of the endpoints and are
independently combinable. Whenever a numerical range with a lower
limit and an upper limit are disclosed, any number falling within
the range is also specifically disclosed.
[0061] Any term, abbreviation or shorthand not defined is
understood to have the ordinary meaning used by a person skilled in
the art at the time the application is filed. The singular forms
"a," "an," and "the," include plural references unless expressly
and unequivocally limited to one instance.
[0062] All of the publications, patents and patent applications
cited in this application are herein incorporated by reference in
their entirety to the same extent as if the disclosure of each
individual publication, patent application or patent was
specifically and individually indicated to be incorporated by
reference in its entirety.
[0063] This written description uses examples to disclose the
invention, including the best mode, and also to enable any person
skilled in the art to make and use the invention. Many
modifications of the exemplary embodiments of the invention
disclosed above will readily occur to those skilled in the art.
Accordingly, the invention is to be construed as including all
structure and methods that fall within the scope of the appended
claims.
EXAMPLES
Example 1
[0064] Samples of Chevron Neutral Oil 100R were received from the
Chevron Richmond Lubricants Oil Plant. Chevron 110RLV base oils
were made by vacuum distilling off a lower boiling fraction from
the Chevron Neutral Oil 100R. The distillation cut points were
approximately 660 to 670.degree. F. The average properties of the
Chevron Neutral Oil 100R base oil, and the properties of two
different Chevron 110RLV base oils are shown below, in Table I:
TABLE-US-00001 TABLE I 110RLV Base 110RLV Base 100R Base Property
Oil Oil Oil Viscosity Index 112 118 106 SimDist (Wt %), .degree. F.
0.5 668 661 619 5 713 711 672 10 727 731 691 20 745 751 714 30 760
766 732 40 773 780 748 50 785 793 764 60 797 807 779 70 810 822 795
80 825 840 813 90 844 864 838 95 859 885 857 99.5 907 945 904
Kinematic Vis @100.degree. C., 4.391 4.540 4.041 mm.sup.2/s Noack
Volatility, wt % 16.2 14.9 23.2 CCS VIS at -25.degree. C. 1367 1414
1233 Flash Point, COC, .degree. C. 216 211 206 Pour Point, .degree.
C. -16 -15 -14 Oxidator BN, hours 25.6 29.1 19.1 Total Aromatics
0.0675 0.0538 0.2264 Noack Volatility/CCS VIS 1.19 1.06 1.88 at
-25.degree. C. .times. 100
[0065] The removal of the low boiling fraction of the Chevron 100R
gave improvements in a number of different desired base oil
properties, including lowering of the Noack volatility, raising of
the flash point, lowering of the pour point, increasing of the
oxidation stability, and reducing of the aromatics. Another benefit
was that the CCS VIS at -25.degree. C. was still maintained well
below 1500 mPas. Prior to this invention, it had been expected that
the removal of the lower boiling fraction would increase the CCS
VIS at -25.degree. C. to well above 1700 mPas.
Example 2
[0066] Others have manufactured base oils having a SUS viscosity at
100.degree. F. of approximately 110, otherwise known as 110N base
oils. One example is ConocoPhillips 110N. Another example is a
"110N" blended with Fischer-Tropsch derived base oil, Chevron 220R,
and Ergon Hygold 100. This example is fully described in U.S.
patent application Ser. No. 12/047,887, filed Mar. 13, 2008.
Kinematic viscosity in mm.sup.2/s at 100.degree. F. can be
converted to SUS viscosity at 100.degree. F. according to the
arithmetic and the reference table provided in ASTM D 2161-05.
[0067] The properties of these two comparison base oils are shown
in Table II.
TABLE-US-00002 TABLE II ConocoPhillips "110N" Example Typical
Property 110N from 12/047,887 Viscosity Index 95 104 Kinematic Vis
@100.degree. C., 4.10 4.067 mm.sup.2/s Noack Volatility, wt % 26.5
40.56 CCS VIS at -25.degree. C. 1500 1259 Flash Point, COC,
.degree. C. 199 -- Pour Point, .degree. C. -12 -23 Vol % Distilled
at 700.degree. F. 14 (Max.) -- Noack Volatility/CCS VIS 1.76 3.22
at -25.degree. C. .times. 100
Example 3
[0068] Blends of 10W-30 multigrade engine oil were made with blends
of different base stocks. They were blended to all have
approximately the same kinematic viscosity at 100.degree. C. An
additive package was selected that was designed to formulate engine
oils meeting both API CJ-4 and ACEA E9 heavy duty engine oil
specifications.
[0069] The composition of these engine oil blends, and their
properties, are described in Table III. The "X"s in the table
indicate what base stocks were included in each of the blends.
TABLE-US-00003 TABLE III Base Stocks, wt % Ref. Blend 1 Blend 2
Blend 3 Chevron 5R >40 Chevron 110RLV X X X Chevron 220R X X X X
Chevron 600R X X Chevron 7R <10 6 cSt Group III Base <20
Stock Additive Package X X X X Properties Spec. Measurements
Viscosity Index 139 140 140 139 Kinematic Vis @100.degree. C.,
11.6-12.4 12.0 12.0 12.0 12.0 mm.sup.2/s API Gravity 31(typical)
31.1 30.9 31.0 31.1 Noack Volatility, wt % 13(Max) 12.28 12.55
12.60 12.21 CCS VIS at -25.degree. C. 5800-7000 6453 6804 6705 6603
Pour Point, .degree. C. -27(Max) -34 -36 -35 -35 HTHS, mPa s
3.4(Min) 3.6 3.6 3.6 3.6 MRV @-30.degree. C., mPa s 60000(Max)
18657 19974 20781 19234 Yield Stress Pass Pass Pass Pass Pass
Scanning Brookfield @ 18657 33361 32172 29805 -30.degree. C., mPa s
Gelation Index 12(Max) 5.4 6.1 6.8 5.6
[0070] The Chevron 110RLV gave a technical advantage, in that much
lower quantities of the more expensive and highly processed Chevron
5R or Chevron 7R were needed to blend excellent 10W-30 engine oils
meeting both API CJ-4 and ACEA E9 heavy duty engine oil
specifications. Blend 1 had no Group III base oil or Group IV base
oil. Blend 2 had less than 10 wt % Group III or Group IV base oil.
Blend 3 had less than 20 wt % Group III or Group IV base oil.
Blends 1, 2, and 3 all contained no highly paraffinic
unconventional base oil.
Example 4
[0071] The chart shown in FIG. 1 was prepared by selecting
different pairs (having a first base stock and a second base stock)
of petroleum derived Chevron base stocks, measuring the CCS VIS at
-25.degree. C. and the Noack volatility of each base stock and
plotting the points (a first point and a second point) on a x-y
chart. Blends of the paired Chevron base stocks were made in
varying proportions and the CCS VIS at -25.degree. C. and the Noack
volatility of each of the blends were measured and used to
construct a curve connecting the first and second points.
[0072] The chart shown in FIG. 1 also includes points where current
commercial multigrade engine oils were tested for CCS VIS at
-25.degree. C. and Noack volatility. They tended to cluster into
areas on the chart. The area circling the small triangles on the
left side of the chart are 5W-XX engine oils, the area circling the
small squares in the center of the chart are 10W-XX engine oils,
and the area circling the small circles on the right side of the
chart are 15W-XX engine oils.
[0073] In this example, base oil requirements for a 10W engine oil
were set having a CCS VIS at -25.degree. C. of 2800 and a Noack
volatility of 14 wt %. The chart in FIG. 1 was referred to, and it
was found that the curve between Chevron 110RLV base oil and
Chevron 220R base oil fell below and close to the point
representing the base oil requirements for the 10W engine oil. This
gave a good prediction that the 10W engine oil requirements could
be met with a blend of only these two base oils, and not requiring
any trim stock.
[0074] If it was desired that the engine oil have mostly Chevron
100R and Chevron 220R base oil, then an amount of trim stock would
need to be used to meet the same base oil requirements. Based on
the chart one would predict that blending in of Chevron 7R trim
stock would be a good choice to bring down the Noack volatility of
the base oil blend to within the desired range. Based on the chart
one would also predict that blending in of Chevron 5R or Chevron 4R
trim stock would be a good choice to bring down the CCS VIS at
-25.degree. C. of the base oil blend to within the desired
range.
Example 5
[0075] A target point with a CCS VIS at -25.degree. C. and Noack
volatility of 3342 and 11.73 was selected. This target point
defined properties that will meet a 10W-XX grade engine oil
specification. This target point was placed on a blend chart. Three
different base stocks were selected that have CCS VIS at
-25.degree. C. and Noack volatilities different from this point,
and their CCS VIS at -25.degree. C. and Noack volatilities were
placed on the chart. This blend chart is demonstrated in FIG. 2.
Curves were drawn between the points defining the CCS VIS at
-25.degree. C. and the Noack volatility of each of the three base
oils. The curves defined a space inside the curves, where the
target point was positioned. This blend chart demonstrates that
these three base oils can be used to make a base oil blend having
approximately the CCS VIS at -25.degree. C. and Noack volatility of
the target point.
[0076] FIG. 2 illustrates a blend chart having a first point
defined by CCS VIS and Noack volatility of Chevron 100R. The blend
chart has a second point defined by the CCS VIS and Noack
volatility of Chevron 7R. The blend chart has a third point defined
by the CCS VIS and Noack volatility of Chevron 220R. Curves are
drawn between the three points to form a ternary blending space. A
target point of a CCS VIS of 3350 and a Noack volatility of 11.75
is placed on the chart. This target point is characteristic of a
typical 10W-XX finished lubricant product base oil blend. The
target point is positioned within the ternary blending space
defined by the three curves drawn between the three different
points. The blend chart instructs a user as to how much of each of
the three base oils may be blended to meet the target point
properties.
[0077] The series of lines constructed between the three edges of
the ternary blending space represent three degrees of distance away
from each base oil component. For instance, going away from 100R
towards the 7R/220R blend curve, a user will encounter three lines
along the way that are specific 75%, 50%, and 25% tie-lines between
100R/220R and 100R/7R blend curves.
[0078] The composition of each blend component at the target point
is defined as a ratio of distances, namely, the distance from the
component point to a perpendicular line through the target point
divided by the distance from the component point to the opposite
edge of the ternary blending space. For example, the amount of 7R
in the base oil blend of 100R/220R/7R would be in between 25% and
50% based on the fact that a perpendicular line through the target
lies in between the tie-lines that are composed of 50% (closer) and
25% (further away) 7R. A similar process is done for 100R and 220R
such that the sum of these compositions is 100%.
* * * * *