Note: Descriptions are shown in the official language in which they were submitted.
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LUBRICANT BASE OILS AND LUBRICANT COMPOSITIONS AND METHODS
FOR MAKING THEM
This invention relates to compositions and methods and in particular to
lubricant
base oils and lubricant compositions and to methods for making them.
Lubricant compositions generally comprise a base oil and one or more
additives.
According to API standard 1509, "ENGINE OIL LICENSING AND CERTIFICATION
SYSTEM", November 2004 version 15th edition Appendix E, base stocks which are
used
for base oils are defined as belonging to one of five Groups as set out in
Table I below.
Table I
Saturated
Sulphur content
Group hydrocarbon content
Viscosity Index
(wt%)
(wt%)
< 90 and/or > 0.03 and
> 80 and < 120
11 > 90 and < 0.03 and
> 80 and < 120
111 > 90 and < 0.03 = and > 120
IV polyalpha olefins
V all base stocks not in Groups I, II, III or IV
Group I base stocks are generally preferred to Group II base stocks for the
manufacture of lubricant compositions for marine 2-stroke and 4-stroke
engines,
particularly for engines operating on heavy fuel oil. However, Group II base
stocks are
becoming increasingly more readily available because older manufacturing
capacity for
Group I basestock is being closed and new manufacturing capacity tends to
manufacture
Group II base stock.
Group II base stocks may have some performance disadvantages compared to Group
I base stocks when used in some lubricant compositions, for example in marine
lubricants.
These disadvantages may include poorer dispersancy, poorer seal swell
performance,
poorer solubility of additives, lower compatibility with fuel oil in marine
engine
applications (which can lead to deposit formation, for example in cool parts
of the engine)
and/or in some aspects, poorer oxidative stability.
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Hydroprocessed base stocks may have advantages and disadvantages (Deckman,
D.E. et al., Hart's Lubricants World, July 1997, pages 46 ¨ 50) when used in
industrial
lubricant applications (Deckman D. E. et al., Hart's Lubricants World, Sept
1997, pages
20-26) and in conunercial, personal vehicle and marine engine oils (Deckman D.
E. et al.,
Hart's Lubricants World, Sept 1997, pages 27 ¨ 28).
According to Deckman D. E. et al., in Hart's Lubricants World, Sept 1997,
pages 27
¨ 28, "Because hydrocracking results in a viscosity loss of the base stocks.,
marine oils
cannot generally be formulated solely with hydrocracked base stocks; but
require the use
of significant amounts of bright stock However, the use of bright stock is not
desirable
because of the presence of oxidatively unstable aromatics".
Base stocks which are made by hydroprocessing, including Group II and Group
III
base stocks, have lower aromatics content and lower sulphur content than Group
I base
stocks.
Base stocks which are polyalphaolefins (Group IV) may also have a high degree
of
saturation.
Base stocks derived from Fischer-Tropsch synthesised, waxy, paraffinic
hydrocarbon
materials also have a low aromatics content and so may also exhibit at least
some of the
poorer performance of Group II and Group III base stocks compared to Group I
base
stocks. WO 00/14187 and WO 2005/066314 relate to lubricant compositions
comprising
Fischer Tropsch derived base stock.
, There remains a need for a base oil composition which overcomes, or at least
mitigates these problems.
It has now been found that the use of 0.2 to 30 % by weight of an aromatic
extract in
a base oil comprising base stock, which base stock comprises at least 95 % by
weight
saturated hydrocarbons, can overcome or at least mitigate these problems.
Thus, according to one aspect of the present invention, there is provided a
liquid
lubricant base oil composition comprising (i) a base stock comprising at least
95 % by
weight saturated hydrocarbons and (ii) 0.2 to 30 % by weight, preferably 0.2
to 18 % or 1
to 30 % by weight, more preferably 1.0 to 18 % by weight, of an aromatic
extract, in which
the aromatic extract has a dimethyl sulphoxide extractable polycyclic
aromatics content of
less than 3 weight %.
According to a second aspect of the present invention, there is provided a
method of
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making a liquid lubricant base oil composition as hereindefined which method
comprises
blending a base stock comprising at least 95 % by weight saturated
hydrocarbons with
sufficient aromatic extract which has a dimethyl sulphoxide extractable
polycyclic
aromatics content of less than 3 weight % to make a liquid lubricant base oil
composition
as hereindefined.
According to a third aspect of the present invention there is provided a
liquid
lubricant composition comprising a lubricant base oil composition as
hereindefined and
one or more additives, preferably selected from the group consisting of
detergents,
dispersants, anti-wear additives, anti-oxidants, anti-foams, corrosion
inhibitors, pour point
depressants, friction modifiers, tackifiers and viscosity index improvers.
The present invention solves the problem defined above by the use of 0.2 to 30
%
by weight of an aromatic extract which has a dimethyl sulphoxide extractable
polycyclic
aromatics content of less than 3 weight % in a liquid lubricant base oil
composition which
base oil comprises a base stock comprising at least 95 % by weight saturated
hydrocarbons. This provides a lubricant base oil which overcomes or at least
mitigates, at
least some of the deficiencies which may be associated with such base stocks.
The lubricant base oil composition of the present invention comprises 0.2 to
30 %
by weight of an aromatic extract. Preferably, the lubricant base oil
composition of the
present invention comprises 0.2 to 18 % or 1.0 to 30 % by weight of the
aromatic extract.
More preferably, the lubricant base oil composition of the present invention
comprises 1.0
to 18 % by weight aromatic extract.
Preferably, the base stock comprising at least 95 % by weight saturated
hydrocarbons comprises a hydroprocessed base stock and/or a base stock derived
from
Fischer-Tropsch synthesised, waxy, paraffinic hydrocarbon material. The
present
invention provides a lubricant base oil which overcomes or at least mitigates,
at least one
of the deficiencies which may be associated with such base stocks, for example
those
deficiencies selected from the group consisting of poor dispersancy (for
example, of soot
and/or deposits), poor seal swell performance, poor solubility of additives
and low
compatibility with fuel oil in marine engine applications (which can lead to
deposit
formation, for example in cool parts of the engine), and also in some aspects,
poor
oxidative stability.
Thus, according to a further aspect of the present invention there is provided
the
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use of 0.2 to 30 % by weight of an aromatic extract which has a dirnethyl
sulphoxide=
extractable polycyclic aromatics content of less than 3 weight % in a liquid
lubricant base
oil composition which base oil comprises a base stock comprising at least 95 %
by weight
saturated hydrocarbons, to mitigate at least one of the deficiencies of the
base stock
selected from the group consisting of poor dispersancy, poor seal swell
performance, poor
solubility of additives and low compatibility with fuel oil in marine engine
applications.
In particular, the present invention provides a method which uses a defined
amount
of aromatic extract, to make a base oil using a hydroprocessed base stock
which may
comprise for example, a Group II base stock and/or a Group III base stock,
and/or using a
base stock which may comprise a polyalphaolefin and/or using a base stock
derived from
Fischer-Tropsch synthesised, waxy, paraffinic hydrocarbon material. This base
oil can be
'used in applications where a Group I base stock has conventionally been used,
such as for
example, in marine engine applications, for example in 2-stroke marine diesel
engine
cylinder oils, 2-stroke marine diesel engine system oils and 4-stroke marine
diesel engine
crankcase lubricant compositions.
The aromatic extract is preferably made by the treatment of at least one
refinery
process stream in a solvent extraction process. Suitable solvent extraction
process include
contacting the at least one refinery process stream with a solvent such as
furfural, n-
methylpyrrolidone, sulphur dioxide, DuoSo1TM or phenol to selectively extract
from the
refinery stream, aromatic and heterocyclic materials and to form a solution of
these
materials in the solvent. The solvent is then recovered from the solution for
recycle to the
extraction process; the resultant product being the aromatic extract.
The manufacture of aromatic extracts is known in the art and is described for
example in "Lubricant base oil and wax processing" A. Sequeira, pages 81-118,
pub.
Marcel Dekker Inc. New York, 1994.
The aromatic extract may be a residual aromatic extract, which may be made by
treatment in an extraction process, of solvent deasphalted vacuum residue
(also known as
DAO) made using DuoSo1TM, propane, butane or mixtures thereof as the solvent
for the
deasphalting.
The aromatic extract may be a distillate aromatic extract (DAE) which is an
= aromatic extract made by treatment in an extraction process, of a
distillate stream from a
vacuum distillation process. Preferably, the distillate aromatic extract is a
treated distillate
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arOmatic extract which is a distillate aromatic extract which has been
subjected to at least
one further treatment. Suitably, the at least one further treatment is
selected from the
group consisting of hydrotreatment, hydrogenation, hydrodesulphurisation, clay
treatment,
acid treatment and further solvent extraction.
5 The aromatic extract may have an aromatics content of 60 to 85 weight %,
which
may be measured by ASTM D 2007.
The aromatic extract may have properties such as those described in Concawe
Product Dossier 92/101 "Aromatic Extracts".
The distillate aromatic extract may haye a boiling point in the range 250 ¨
680 C,
which may be measured according to ASTM D 2887. The distillate aromatic
extract may
have a kinematic viscosity at 40 C in the range 5 ¨ 18000 mm2/s, which may be
measured
according to ASTM D 445. The distillate aromatic extract may have a kinematic
viscosity
at 100 C in the range 3 ¨ 60 mm2/s, which may be measured according to ASTM D
445.
The distillate aromatic extract may have an average molecular mass in the
range 300 ¨ 580,
which may be measured according to ASTM D 2887. The distillate aromatic
extract may
have a carbon number range in the range C15 ¨ C54, which may be measured
according to
ASTM D 2887. The distillate aromatic extract may have an aromatic content in
the range
65 ¨ 85 weight %, which may be measured according to ASTM D 2007.
The residual aro,matic extract may have a boiling point of greater than 380
C,
which may be measured according to ASTM D 2887. The residual aromatic extract
may
have a kinematic viscosity at 40 C of greater than 4000 mm2/s, which may be
measured
according to ASTM D 445. The residual aromatic extract may have a kinematic
viscosity
at 100 C in the range 60 ¨ 330 mm2/s, which may be measured according to ASTM
D
445. The residual aromatic extract may have an average molecular mass of
greater than
400, which may be measured according to ASTM D 2887. The residual aromatic
extract
may have a carbon number range of greater than C25, which may be measured
according to
ASTM D 2887. The residual aromatic extract may have an aromatic content in the
range
60 ¨ 85 weight %, which may be measured according to ASTM D 2007.
Aromatic extracts may comprise polycyclic aromatic compounds (PAC's) some of
which are carcinogens. The amount of material (weight %) which can be
extracted into
dimethyl sulphoxide (DMSO) is used as an indication of the amount of
unacceptable
material (including polycyclic aromatic compounds) in the aromatic extracts.
IP 346
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(Institute of Petroleum Test Method 346) is a method used for determining
weight %
DMSO extract. Aromatic extracts with greater that 3 weight % dimethyl
sulphoxide
extractable polycyclic aromatics content are classed as carcinogenic and give
rise to
requirements in several jurisdictions that the material be labelled with
certain symbols and
risk phrases to identify health, safety and environmental hazards. For this
reason at least,
the aromatic extract has less than 3 weight % dimethyl sulphoxide extractable
polycyclic
aromatics content (low PCA extract). More preferably, the aromatic extract is
a residual
aromatic extract or a treated distillate aromatic extract, with less than 3
weight % dimethyl
sulphoxide extractable polycyclic aromatics content.
Preferably, the aromatic extract does not contain any significant amount of
wax,
because if present, wax may deposit in use.
The base stock of the present invention comprising at least 95 % by weight
saturated hydrocarbons may comprise both a hydroprocessed base stock and a
base stock
derived from Fischer-Tropsch synthesised, waxy, paraffinic hydrocarbon
material.
Suitably, base stock of the present invention comprising at least 95 % by
weight saturated
hydrocarbons may comprise a hydroprocessed base stock or a base stock derived
from
Fischer-Tropsch synthesised, waxy, paraffinic hydrocarbon material.
The hydroprocessed base stock is preferably a Group II and/or Group III base
stock, such as defined according to API standard 1509, "ENGINE OIL LICENSING
AND
CERTIFICATION SYSTEM", November 2004 version 15th edition Appendix E.
The base stock comprising at least 95 % by weight saturated hydrocarbons
preferably comprises a Group II and/or Group III base stock, such as defined
according to
API standard 1509, "ENGINE OIL LICENSING AND CERTIFICATION SYSTEM",
November 2004 version 15th edition Appendix E, comprising at least 95% by
weight
saturated hydrocarbons.
Preferably, the Group II base stock or Group III base stock is a
hydroprocessed
base stock which may be made by hydroprocessing, preferably of vacuum
distillate or
deasphalted vacuum residue, or by hydroisomerising the bottoms stream from a
clean fuels
hydrocracker. The manufacture of base stock by hydroprocessing is known in the
art and
is described for example in "Lubricant base oil and wax processing" A.
Sequeira, pages
119 - 152, pub. Marcel Dekker Inc. New York, 1994.
The base stock comprising at least 95 % by weight saturated hydrocarbons may
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=
comprise one or more polyalphaolefm.
The base stock derived from a Pischer-Tropsch synthesised, waxy, paraffinic
hydrocarbon material may be made by any suitable known process for the
manufacture of
.base stock from Fischer Tropsch process. Processes for the manufacture of a
base stock
derived from Fischer-Tropsch synthesised, waxy, paraffinic hydrocarbon
material which
may be used, are described for example in U84943672, EP-A-0668342 and EP-A-
0776959. = Thus, the base stock
=
=
may be made by the steps of (i) producing Syngas, (ii) Fischer-Tropsoh
bynthesis of
hydrocarbons from the Syngas, hydrocracking Of the hydrocarbons to produce
naphtha =
and diesel/kerosene fuel process streams together with a waxy paraffmic
residue and (iv)
.hydroisomerising the waxy residue to produce the base stock. = ==
The liquid lubricant base oil composition according to the present invention
May
be made by blending a base stock comprising at least 95 % by weight saturated
=
hydrocarbons with sufficient an aromatic extract to make the lubricant base
oil
. 15 composition. The *lading may be performed in a batch blending process'
or in a = .
continuous blending process. Batch blending may be performed by introducing
the base
= stock and aromatic extract into a blend kettle whilst alining and/or
agitating the blending
components. Continuous blending may be performed using an in-line mixer to
blend the
base stook and aromatic extract. Heating may be necessary during the blending
to .
facilitate handling of the aromatics extracts.
Preferably, the liquid lubricant base oil composition of the present invention
has a
. == viscosity in the range 7 to 40 cSt at 100 C.
The liquid lubricant base oil composition of the present invention is
particularly
. useful for the manufacture of 2-stroke marine diesel engine cylinder
oils, 2-stroke marine
= 25 diesel 'engine system oils or 4-stroke marine diesel engine crankcase
lubricant
' compositions.
= The liquid lubricant composition according to the present invention
comprises a
liquid lubricant base oil composition as hereindefined and one or more
aaditives,
= preferabli selected from the group consisting of detergents, dispersants,
anti-wear
additives, anti-oxidants, anti-foams, corrosion inhibitors, pour point
depressants, friction
modifiers, tackifiers and viscosity index improvers.
. The concentrations of additives in the lubricant composition
according to the -
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=
present invention depend upon the use for which the lubricant composition is
intended.
One or more anti-oxidants may be present in the lubricant composition at a
total
concentration by weight of 0 to 1 %, usually at a concentration by weight of
not greater
than 0.5 %.
One or more anti-wear additives may be present in the lubricant composition at
a
total concentration by weight of 0 to 2 %, usually at a concentration by
weight of not
greater than 1 %.
One or more high over-based detergents may be present in the lubricant
composition at a total concentration by weight of 0 to 40 %.
One or more low base detergents may be present in the lubricant composition at
a
total concentration by weight of 0 to10 %.
One or more neutral detergents may be present in the lubricant composition at
a
total concentration by weight of 0 to 2 %:
One or more dispersants may be present in the lubricant composition at a total
concentration by weight of 0 to 10%.
One or more anti-foams may be present in the lubricant composition at a total
concentration by weight of 0 to 0.1 %.
One or more corrosion inhibitors may be present in the lubricant composition
at a
total concentration by weight of 0 to 1 %.
One or more pour point depressants may be present in the lubricant composition
at
a total concentration by weight of 0 to 1 %.
One or more friction modifiers may be present in the lubricant composition at
a
total concentration by weight of 0 to 5%.
One or more tackifiers may be present in the lubricant composition at a total
concentration by weight of 0 to 15 %.
One or more viscosity index improvers may be present in the lubricant
composition at a
total concentration by weight of 0 to 20 %.
The concentration ranges for the additives may be independent of each other.
Alternatively, combinations of such concentration ranges may be used for any
particular
lubricant composition.
The liquid lubricant compositions of the present invention may be used as a 2-
stroke marine diesel engine cylinder oil, 2-stroke marine diesel engine system
oil or
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4-stroke marine diesel engine crankcase lubricant composition.
The concentration ranges for additives for such lubricant compositions
according to
the present invention are given in the Table II below. Such concentration
ranges may be
independent of each other. Alternatively, combinations of such concentration
ranges may
be used for any particular lubricant composition.
Table II.
o
t..)
=
=
oe
=
Concentration ranges are expressed in % by weight of the liquid lubricant
composition. t..)
.6.
High Anti-
Viscosity
Lubricant Low base Neutral Anti-
Corrosion Pour Point Anti-
overbased wear Dispersant
Index
Composition detergent detergent foam inhibitor Depressant
oxidant
- detergent additive
Improver
n
0 ¨ 4,
Cylinder oil
0
I.,
5-40 0-10 0 ¨ 2 0 ¨ 2
preferably 0 ¨ 0.1 0 - 1 0 ¨ 1 0-20 0 ¨ 1 0,
-,
lubricant
co
-,
0.5 ¨ 4
0
0
2-stroke
0
c) 0
i
crank case
0
co
1
0 ¨ 5 0 ¨ 5 0 ¨ 1 0 ¨ 2 0 ¨ 1.5 0 ¨
0.1 0 - 0.2 0 ¨ 1 0-20 0 ¨ 1 ,
lubricant
(System Oil) .
4-stroke 0 ¨ 10,
crank case 3-30 0-10 0 ¨ 2 0 ¨ 2
preferably 0 ¨ 0.1 0 ¨ 0.2 0- 1 0-20 0 ¨ 1
.o
n
lubricant 0.3 - 10
to
t..)
=
=
oe
-a
=
=
u,
u,
.6.
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The invention will now be described by way of example only and with reference
to
Figure 1 which is a graph of the performance of base oil with various amounts
of aromatic
extract.
In these experiments a hydroprocessed base stock was a Group II base stock
comprising at least 97 % by weight saturated hydrocarbons was used. The
aromatic extract
was a low PCA brightstock extract (less than 3 % polycyclic aromatics,
brightstock
ftufural extract) provided by Shell. Properties of these components are given
in Table III
below.
Table III General properties of components
Components Test Method Jurong 500N
Aromatic Extract
Base stock (AE)
Type Group II Aromatic Extract
KV40, mm2/s (cSt) IP71 91.58
KV100, min2/s (cSt) IP71 10.64 71.47
VI IP226 99
Density, g/cm3 (15 C) IP365 0.8746 0.9897
Flash point (PMCC), C IP34 232.3 284.3
Flash point (COC) , C IP36 266 308
Pour point, 'V IP15 -18 -12
Colour ASTM D1500 0.1 >8
TAN, mg KOH/g IP1A <0.05 0.09
TBN, mg KOH/g IP276 <0.05 2.14
Sulphur, % ASTM D4951 0.0037 4.13
Nitrogen, % ASTM D5762 0.0027 0.11
Demulsibility, secs IP19 75
Dialysis, % wt BAM72 <0.1 <0.1
Oxidation IP48 IP48 Rams bottom
Viscosity ratio 3.06 carbon - 4.3%
Carbon before, wt. % 0.05
Carbon after, wt. % 0.60
Carbon , A 0.55
Carbon types wt % BAM76
Viscosity too high
Carbon, aromatic CA 1.2
to permit
Carbon, naphthenic CN 67.2
determination
Carbon, paraffinic Cp 31.6
Hydrocarbon types wt % D2007
Saturates 97.9 11.3
Aromatics 2.1 80.2
Polars <0.1 8.5
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The base stock and aromatic extract were shown not to contain any significant
amounts of waxy materials. Base oil compositions were prepared by blending the
aromatic ,
extract (AE) with various amounts of the Group II base stock. Properties of
the base oil
compositions are given in Table IV below.
Table IV
Sample Test Method Example 1 Example 2
Base Oil Composition 88% Group II 76% Group II
(weight %) 12% AE 24%AE
KV40, mm2/s (cSt) IP71 162.4
KV100, mm2/s (cSt) IP71 12.3 14.43
VI IP226 92 85
Density, g/cm3 IP365 0.8870 0.9005
Flash point (PMCC) , IP34 238.3 236.1
C
Flash point (COC) , C IP36 254 264
Pour point, C IP15 -15 -12
Colour ASTM D1500 - 6.1 >8
TAN, mg KOH/g IP1A <0.05 <0.05
TBN, mg KOH/g IP276 0.22 0.47
=
Sulphur, wt. % ASTM D4951 0.49
0.98
Nitrogen, wt. % ASTM D5762 0.019 0.032
Demulsibility, secs IP19 405 630
Dialysis, % wt BAM72 <0.1 <0.1
Oxidation IP48 IP48
Viscosity ratio 1.18 1.40
Carbon before, wt. % 0.31 0.69
Carbon after, wt. % 0.87 2.37
Carbon , A 0.56 1.68
Carbon types wt % BAM76
Carbon, aromatic CA 4.4 7.1
Carbon, naphthenic CN 63.7 63.0
Carbon, paraffinic Cp 31.9 29.9
Viscosity gravity ASTM D2501 0.799 0.902
constant
Further base oils were prepared using the Group II base stock and the aromatic
extract in other amounts. Oxidation properties of the base oils were tested
according to the
Institute of Petroleum procedure IP48 and the results are given in Table V
below:
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=
Table V.
Wt. % Sample A Carbon Carbon A carbon
aromatic viscosity unoxidized oxidized
extract in Ratio
=
base oil
0 Experiment A 3.06 0.05 0.60 0.55
3 Example 3 1.18 0.12 0.33 0.21
6 Example 4 1.11 0.20 0.37 0.17
12 Example 1 1.18 0.31 0.87 0.56
18 Example 5 1.30 0.52 1.35 0.83
24 Example 2 .1.40 0.69 2.37 = 1.68
30 Example 6 1.60 0.87 2.76 1.89
Experiment A is not according to the present invention because it does not
contain
any aromatic extract.
The results of the change in carbon (A carbon) and viscosity ratio at the
different
concentrations of aromatic extract in the base oil are also shown in Figure 1.
The results of the A carbon and viscosity ratio show that the aromatic extract
provides an improvement in A carbon at a concentration of aromatic extract up
to about 12
% by weight and an improvement in viscosity ratio at a concentration of
aromatics extract
of up to 30 % by weight.
These results show the beneficial effect of the presence of 0.2 to 30 % by
weight of
aromatic extract in a base oil composition comprising a base stock comprising
at least 95
weight % saturated hydrocarbons.
Lubricant compositions suitable for use in a marine 4-stroke engine using
heavy
fuel were prepared using a salicylate-rich additive package and base oils
comprising
different amounts of aromatic extract.
Properties of the formulated lubricant compositions are shown in Table VI
below.
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Table VI.
Base oil blend used in Test 100% Group II 88% Group II 76% Group II
lubricant Methods 12% AE . 24% AE
Sample Example 7 Example 8
KV40, mm2/s (cSt) IP71 99.28 124.2 160.4
KV100, inm2/s (cSt) IP71 11.63 13.12 15.04
VI IP226 105 99 93
TBN, mg KOH/g IP276 38.71 40.59 40.29
Pour Point, C IP15 -21 -18 -15
Flash point (PMCC) , IP34 218.8 220.2 226.2
C '
Metals, ppm ICP
Ca 14996 13641 13667
565 481 483
Zn 518 505 503
Si 8 11 12
Na 54 50 50
Foam, ml/ml IP146
Sequence 1 0/0 0/0 0/0
Sequence 2 280/0 350/0 390/0
Sequence 3 0/0 10/0 10/0
Density, g/cm3 IP365 0.9018 0.9123 0.9231
ARV, mins IP313 20.6 25.1 31.7
Demulsibility, ml ASTM 1/0/79 1/0/79 1/0/79
D1401 (60 mins. 82 C) (60 mins. 82 C) (60 mins. 82
C)
Oxidation properties of the lubricant compositions were measured. The results
are
shown in Table VII below.
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Table VII.
Base oil used in Test 100% Group II 88% Group II 76% Group II
lubricant Method 12% AE 24% AE
=
composition
Sample Example 7 Example 8
Isothermal ISOT
oxidation test 72hrs @
(ISOT) 165 C
A BN, % -1.42 -2.60 -2.87
A KV 40, % +3.02 +8.9 +22.8
A KV100, % +0.25 = +0.70 +1.47
Panel Coker BEM144 68.1 121.4 137.1
aluminium
panels 221ns
325 C
Panel Coker In-house
Steel panels method 107.4/147.7 33.3/28.9 10.2/9.4
2x4hrs 320 C
= Average 127.6 31.1 9.8
Cu corrosion ASTM N/A la slight la slight tarnish
3 hrs 120 C D130 tarnish
Cu corrosion ASTM N/A la slight la slight tarnish
3hrs 150 C D130 tarnish
Rusting IP135B N/A No rusting No rusting
characteristics
The results in Table VII show some improvement is observed within the Panel
Coker Test using steel panels undertaken according to the in-house method at
12 and 24 %
5 by weight aromatic extract indicating an improvement within the solvency
of the lubricant
composition when aromatic extract is used.
Wear properties of the lubricant compositions were measured using a Cameron
Plint test. The results are shown in Table VIII below.
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16
=
Table VIII.
Mean
Specific Wear
Wear vol. Wear Rate Scar Pin wear
Test
mm3 (SWR) Depth mm
m3/Nm (MWSD)
jtm
Bad reference 1074 0.0643 5.82E-17 22.7 0.024
Good reference 1082 0.0119 7.35E-18 12.1 0.006
100% Gp II 006A/02 0.00182 1.12E-18 18.9 0.007
88% Group II
010A/01 0 0.00 E+00 0 0.002
12% AE
76% Group II
011A/01 0.0254 1.57E-17 18 0.009
24% AE
The wear properties were compared against reference lubricant formulations
with
good and bad wear performance. The results show an exceptionally good wear
performance for a lubricant composition with a base oil comprising 12 % by
weight
aromatic extract. However, at the higher concentration of 24 % by weight
aromatics
extract in the base oil, there is no significant improvement in wear
performance compared
to the composition with 100% Group II base oil. This data implies that there
is an
optimum concentration of aromatic extract for wear performance. ,
=
