U.S. patent application number 10/811564 was filed with the patent office on 2004-10-28 for fuel composition containing molybdenum source and metal-containing detergent, and its use in two-stroke engines.
Invention is credited to Clague, Nicholas P., Growcott, Peter, Haynes, Michael A..
Application Number | 20040211112 10/811564 |
Document ID | / |
Family ID | 32946936 |
Filed Date | 2004-10-28 |
United States Patent
Application |
20040211112 |
Kind Code |
A1 |
Clague, Nicholas P. ; et
al. |
October 28, 2004 |
Fuel composition containing molybdenum source and metal-containing
detergent, and its use in two-stroke engines
Abstract
A fuel composition, and a method and an apparatus for combusting
it in a two-stroke engine, in which molybdenum introduced from the
fuel will interact with alkaline earth metal originating from a
detergent or other co-ingredient of the fuel in the combustion
products to increase detergency without increasing the level of
alkaline earth metal or compounds present in the fuel or combustion
products thereof. In this manner, the engine operates more cleanly
and efficiently without increasing the risk of harmful alkaline
earth materials and compounds thereof blocking and poisoning
catalysts, sensors and/or automotive on-board diagnostic devices,
and it can lead to improved durability of exhaust after treatment
systems.
Inventors: |
Clague, Nicholas P.;
(Bracknell, GB) ; Haynes, Michael A.; (Oxford,
GB) ; Growcott, Peter; (Hartley Wintney, GB) |
Correspondence
Address: |
DENNIS H. RAINEAR
CHIEF PATENT COUNSEL, ETHYL CORPORATION
330 SOUTH FOURTH STREET
RICHMOND
VA
23219
US
|
Family ID: |
32946936 |
Appl. No.: |
10/811564 |
Filed: |
March 29, 2004 |
Current U.S.
Class: |
44/354 ; 44/358;
44/363; 44/365; 44/367 |
Current CPC
Class: |
C10L 10/08 20130101;
C10L 1/14 20130101; C10L 10/06 20130101; C10M 2215/28 20130101;
C10L 1/2383 20130101; C10N 2010/12 20130101; C10M 163/00 20130101;
C10L 10/02 20130101; C10L 1/301 20130101; C10L 1/2437 20130101;
C10N 2040/255 20200501; C10M 2207/026 20130101; C10N 2040/26
20130101; C10M 2215/064 20130101; C10M 2219/046 20130101; C10M
2227/09 20130101; C10L 1/1832 20130101; C10M 169/045 20130101; C10L
1/143 20130101; C10M 2229/02 20130101; C10N 2030/50 20200501; C10L
1/285 20130101; C10N 2030/04 20130101; C10N 2010/04 20130101; C10L
1/223 20130101 |
Class at
Publication: |
044/354 ;
044/358; 044/365; 044/367; 044/363 |
International
Class: |
C10L 001/30; C10L
001/12; C10L 001/22; C10L 001/24; C10L 001/18 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 23, 2003 |
EP |
03252539.6 |
Claims
1. Fuel composition for two-stroke engines, comprising: combustible
hydrocarbonaceous liquid fuel; lubricant comprising an oil of
lubricating viscosity; a detergent comprising an alkaline earth
metal-containing compound; and a molybdenum source.
2. The fuel composition of claim 1, wherein the alkaline earth
metal-containing compound comprises a salt selected-from the group
consisting of calcium sulphonate, calcium phenate, magnesium
sulphonate, and magnesium phenate, or combinations and mixtures
thereof.
3. The fuel composition of claim 1 or claim 2, wherein the
detergent comprises a detergent selected from the group consisting
of neutral calcium sulphonate detergents and neutral calcium
phenate detergents, or combinations and mixtures thereof.
4. The fuel composition of any one of claims 1 to 3, wherein the
molybdenum source is selected from the group consisting of
molybdenum trioxide, molybdenum sulfonates, molybdenum phenates,
molybdenum salicylates, molybdenum carboxylates, mono-nuclear and
di-nuclear and tri-nuclear molybdenum dithiocarbamates, neutral and
overbased molybdenum salicylates, overbased molybdenum phenates,
overbased molybdenum sulfonates, ammonium mclybdate, sodium
molybdate and potassium molybdate, and molybdenum halides,
compounds derived from molybdenum reacted with amines and alcohols,
and combinations and mixtures thereof.
5. The fuel composition of any one of claims 1 to 4, wherein the
molybdenum source comprises an organomolybdenum complex prepared by
reacting fatty oil, diethanolamine, and a molybdenum source.
6. The fuel composition of any one of claims 1 to 5, wherein the
liquid fuel is selected from the group consisting of diesel fuel,
biodiesel fuel, biodiesel-derived fuel, synthetic diesel, jet fuel,
alcohols, ethers, kerosene, Fischer-Tropsch fuels, liquid petroleum
gas, fuels derived from coal, genetically engineered biofuels and
crops and extracts therefrom, unleaded motor gasolines,
reformulated gasolines which contain both hydrocarbons of the
gasoline boiling range and fuel-soluble oxygenated blending agents,
gasoline, bunker fuel, and mixtures thereof, and emulsions,
suspensions, and dispersions thereof in water, alcohol, and other
carrier fluids.
7. The fuel composition of any one of claims 1 to 6, comprising
about 95 to about 99 wt. % combustible hydrocarbonaceous liquid
fuel, about 1 to about 5 wt. % lubricant comprising an oil of
lubricating viscosity, about 0.001 to about 0.05 wt. % alkaline
earth metal-containing compound, and about 1 ppm to about 10 ppm Mo
from the molybdenum source.
8. A method for controlling the deleterious effect on exhaust
emissions after-treatment and control devices of at least one metal
contaminant and compounds thereof in an exhaust stream from the
combustion of a combustible fuel composition in a combustion system
of a two-stroke engine, said method comprising the steps of: (a)
intaking a fuel composition into a combustion system of a
two-stroke engine, wherein the fuel composition comprises i)
combustible hydrocarbonaceous liquid fuel, ii) lubricant comprising
an oil of lubricating viscosity, iii) a detergent comprising an
alkaline earth metal-containing compound, and iv) a molybdenum
source; (b) combusting in the combustion system the
hydrocarbonaceous fuel to produce combustion products comprising at
least one material selected from the group consisting of alkaline
earth metal and compounds thereof; (c) contacting the molybdenum
with at least one of the alkaline earth metal, and compounds
thereof, in the combustion products, (d) flowing the combustion
products over at least one of a catalyst, a sensor, and an on-board
diagnostic device, or a combination of these; wherein the
molybdenum interacts with at least one of the alkaline earth metal
or compounds thereof effective to increase detergency, as compared
to conducting the same method without including the molybdenum
source in the fuel composition, and without blocking the catalyst,
sensor and/or on-board diagnostic device.
9. The method of claim 8, wherein the fuel composition is a
composition according to any one of claims 2 to 7.
10. The method of claim 8 or claim 9 wherein the alkaline earth
metal comprises calcium, and the alkaline earth metal compound in
reduced level is calcium sulphate.
11. The method of any one of claims 8 to 10, wherein the alkaline
earth metal and compounds thereof in the combustion products
originate from the detergent contained in the fuel composition.
12. The method of any one of claims 8 to 11, wherein the combustion
system further comprises flowing the combustion products through an
after-treatment system.
13. The method of claim 12, wherein the combustion system further
comprises flowing the combustion products through an
after-treatment system, wherein the after-treatment system is
selected from the group consisting of a catalyzed diesel
particulate filter and a continuously regenerating technology
diesel particulate filter.
14. An apparatus for performing the method of any one of claims 8
to 13, said apparatus comprising: (a) a two-stroke engine including
a combustion chamber adapted to combust a fuel composition; (b) a
means to introduce the fuel composition into the combustion
chamber; (c) means to initiate combustion of the fuel composition
in the combustion chamber; (d) a means to convey combustion
products from the combustion chamber; (e) means to reduce the
amount of at least one pollutant from the combustion product.
15. The apparatus of claim 14 comprising storage means containing a
fuel composition according to any one of claims 1 to 7.
16. The apparatus of claim 14 or claim 15, wherein the means (e)
comprises an after treatment system selected from the group
consisting of a diesel oxidation catalyst, a catalyzed diesel
particulate matter filter, and a continuously regenerating
technology diesel particulate filter.
17. The apparatus of any one of claims 14 to 16, wherein the
apparatus is selected from the group consisting of a motorcycle, a
moped, a snow mobile, an all terrain vehicle, tractor, mining
equipment, construction equipment, a marine outboard motor, a lawn
mower, a chain saw, a pump, an electrical generator, a garden
tiller, a landscaping hedge trimmer, and a back pack blower.
18. The apparatus of any one of claims 14 to 17, wherein the
apparatus is selected from the group consisting of a gasoline
engine and a diesel engine.
19. A method for improving the durability of an after-treatment
device for a two-stroke engine combustion system, said method
comprising contacting a fuel composition containing
hydrocarbonaceous fuel, oil of lubricating viscosity, alkaline
earth metal-containing detergent compound, and a molybdenum source,
and its combustion products a combustion system, with the
molybdenum source in an amount sufficient for the molybdenum to
interact with one or more contaminants comprising an alkaline earth
metal or alkaline earth metal compounds thereof in said fuel
composition and combustion products thereof effective to thereby
increase detergency without increasing the amount of alkaline earth
metal compound contaminants contacting the after-treatment
device.
20. The method according to claim 19 wherein the fuel composition
is a composition according to any one of claims 2 to 7.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of priority under 35
U.S.C. .sctn.119 to European patent application serial no.
03252539.6, filed Apr. 23, 2003, the entire disclosure and contents
of which are incorporated herein by reference for all purposes.
Description
[0002] 1. Field of the Invention
[0003] The present invention relates to a fuel composition for
two-stroke engines containing a molybdenum source and an alkaline
earth metal-containing detergent compound, and a method of its use
for delivering molybdenum and the alkaline earth metal-containing
detergent into a fuel combustion system and to the exhaust
therefrom of a two-stroke engine. By the present invention, the
molybdenum increases the detergent action of an alkaline earth
metal detergent compound included in the fuel composition. This
enhancement permits use of lower yet still effective levels of
metal-based detergent in the fuel composition, and thus lower
levels of alkaline earth metals are present in the fuel composition
and resulting fuel combustion products. The decreased introduction
level of alkaline earth metal as detergent, in turn, directly
results in reduced levels of deposition of alkaline earth metal
compounds upon engine monitoring components such as sensors and
automotive on-board diagnostic devices and blocking of catalysts in
the exhaust system. The invention thus provides an improved
combustion fuel composition for two-stroke engines containing an
alkaline earth metal-containing detergent and a molybdenum source,
and a method and apparatus for its use in improving combustion
efficiency in a combustion unit and durability of associated
exhaust after-treatment systems.
[0004] 2. Background of the Invention
[0005] Two-stroke combustion engines are widely used in
transportation and recreational vehicles such as motorcycles,
mopeds, snow mobiles and marine outboard motors, and also in
landscaping equipment such as lawn mowers and chain saws.
Two-stroke engines operate by combusting a mixture of fuel and a
lubricant in prescribed proportions. The lubricant side of the
two-stroke engine fuel composition typically includes mineral oil
or a synthetic base fluid of lubricating viscosity, and
performance-enhancing lubricant additives such as a detergent
and/or dispersant. The detergent has been used to help provide
cleaner combustion, reduce carbon deposits, and reduce smoke in the
exhaust from the combustion system.
[0006] Two-stroke combustion engines generally operate in a facile,
reliable, and power-efficient manner. However, the fuel-lubricant
mixtures used as the combustion fuel in these two-stroke combustion
engines also tend to form combustion products with relatively
higher amounts of unburned fuel components, particulate matter, or
other pollutants than when combusted in four-cycle engines of
comparable power. Consequently, two-stroke engines have come under
greater scrutiny and regulation from an emission control
standpoint. To meet emission standards already applicable to or
planned for vehicles or devices operating on two-stroke engines,
the exhaust systems are being developed or retrofitted to
incorporate catalytic units such as diesel oxidation catalysts,
catalyzed particulate matter filters, continuous regenerating
filter systems, and the like. The development and refinement of
practical and economical versions of these emission control devices
is still ongoing, especially with respect to meeting stricter
emission standards under consideration or adopted for
implementation in the near future in important markets including
the EU.
[0007] A number of patent references describe various chemistries
of two-stroke engine fuels.
[0008] For instance, U.S. Pat. No. 5,498,353 describes a
semi-synthetic two-stroke engine oil formulation with high
lubricity and high detergency meeting low smoke and low exhaust
system blocking requirements, comprising a base oil consisting of a
high-viscosity mineral oil, medium-viscosity mineral oil, a solvent
and a mixture of three polyisobutylenes with different molecular
weights, and appropriate detergents, such as phenates and
sulfonates of calcium, and dispersants.
[0009] U.S. Pat. No. 6,528,459 B1 describes a marine lubricant for
a two-stroke engine powered with a fuel having a sulfur content
less than 1%, in which the lubricant consists of a mixture of
distillates used as lubricating bases containing amounts of
dispersing additive of succinimide type, an overbased detergent
additive of sulfonate type, an overbased detergent additive of the
phenate type, in respective amounts satisfying certain stated
proportional relationships. Alkaline earth sulfonates and phenates
are described relative to the last two mentioned components.
[0010] The addition of molybdenum compounds to liquid fuels
containing lubricating oils has been described in the patent
literature. For instance, U.S. Pat. Nos. 5,445,749 describes a
method for lubricating metal-ceramic interfaces in hybrid engines
by supplying a composition to the interface comprising a carrier
fluid and a thiocarbamate, such as molybdenum dithiocarbamates. The
carrier fluid is described as being a lubricating oil supplied from
a sump, or alternatively a liquid fuel. U.S. Pat. Nos. 5,445,749
includes examples of compositions prepared of molybdenum
dithiocarbamates in liquid fuel as the carrier fluid, and base oil
and diluent oil are the only other indicated ingredients of those
lubricated fuel compositions.
[0011] The addition of molybdenum compounds together with or
without a metal-containing detergent to crankcase lubrication oils
has been described in the patent literature. U.S. Pat. No.
6,300,291 describes a lubricating oil composition for use in an
engine crankcase to improve low temperature anti-wear performance
and fuel economy containing an oil of lubricating viscosity, at
least one calcium detergent providing calcium in an amount of 0.058
to 0.58 wt. %, at least one soluble molybdenum compound providing
Mo in amount of up to 350 ppm Mo, at least one nitrogen containing
friction modifier, and at least one zinc
dihydrocarbyldithiophosphate compound providing phosphorous in
amount of about 0.1 wt. %, where the composition has a NOACK
volatility of about 15.5 wt % or less.
[0012] U.S. Pat. No. 6,074,993 also describes a lubricating
composition for use in an engine crankcase to improve fuel economy
and wet clutch friction properties containing an oil of lubricating
viscosity, at least one overbased calcium or magnesium detergent,
and oil soluble dimeric molybdenum compound providing Mo in an
amount of up to 2000 ppm Mo, an oil soluble trinuclear molybdenum
compound providing Mo in an amount of up to 350 ppm Mo, at least
one organic friction modifier, and at least one zinc
dihydrocarbyldithiophosphate compound, where the composition has a
TBN of at least 3.6 from the overbased detergent and a NOACK
volatility of about 0.15 wt % or less.
[0013] European Patent EP 0 874 040 B1 describes synergistic
organomolybdenum antiwear compositions consisting of (a) an
organomolybdenum complex prepared by reacting about 1 mole fatty
oil, 1.0 to 2.5 moles diethanolamine and a molybdenum source
sufficient to yield 0.1 to 12.0 percent of molybdenum based on the
weight of the complex, and (b) an organic sulfur compound selected
from the group consisting of 1,3,4-thiadiazole compounds of a
specified formula. EP 0 874 040 B1 also describes lubricating
compositions containing 0.1 to 10.0 percent by weight of the
antiwear composition in combination with a major portion of oil of
lubricating viscosity.
[0014] U.S. Pat. Nos. 6,509,303; 6,528,461; and 6,528,463 describe
organic soluble molybdenum complex additives and lubricating motor
oils containing them.
[0015] However, among other things, the above-mentioned patent
references fail to describe any recognition that certain
metal-based detergents, if used as described therein, can be a
source of contaminants having a detrimental effect on the
combustion system's catalysts, after treatment system, and/or other
emission control systems. It is desirable to increase the
performance of a fuel composition for two-stroke engines by use of
performance-enhancing additives yet without causing undesirable
increases in contaminants emanating from additives that may result
in catalyst build up and poisoning, after treatment system
malfunction, and/or in increased emissions of pollutants.
SUMMARY OF THE INVENTION
[0016] The present invention relates to an improved fuel
composition for two-stroke engines containing a hydrocarbonaceous
fuel, a lubricant of lubricating viscosity, an alkaline earth
metal-containing detergent compound, and a molybdenum source. The
invention also relates to method of using, and apparatus for use
of, the fuel composition to improve combustion efficiency in a
combustion unit, and which additionally or alternatively improves
durability of an associated exhaust after-treatment system.
[0017] By the present invention, a fuel composition comprises a
fuel-lubricant admixture including an alkaline earth
metal-containing detergent compound and a source of molybdenum that
interact to yield increased detergency when the fuel composition is
combusted in two-stroke engine. This synergism permits use of lower
levels of alkaline earth metal-containing detergent in the fuel
composition to meet a desired minimal level of detergency. The
lower alkaline earth metal content made possible by the addition of
the molybdenum source in turn serves to reduce the amount of
alkaline earth metal available for deposition as alkaline earth
metal compounds upon catalysts deployed in the exhaust and
combustion after-treatment systems, or engine monitoring components
such as sensors and automotive on-board diagnostic devices. This
reduces blocking or glazing of the catalysts, and thereby increases
the durability and effective lifespan of the catalysts used in the
exhaust treatment system(s). The reduction in the detergent treat
rate required for detergent action can also permit cost reductions
in the overall fuel additive package, depending on the comparative
cost of the small addition rate of molybdenum source needed to
induce the boost in detergency.
[0018] In another embodiment of this invention, the fuel
composition is formulated by the addition of the molybdenum source
without any concomitant reduction in the level of detergent. In
this approach, the level of detergency achieved is significantly
increased beyond that obtained without inclusion of the molybdenum
source in the fuel composition without incurring any drawbacks such
as increased deposition of alkaline earth metal compounds on
catalysts in the exhaust or after-treatment system.
[0019] In one embodiment of this invention, the fuel composition
having these advantages and capabilities comprises about 95 to
about 99.5 wt. % combustible hydrocarbonaceous liquid fuel, about 1
to about 5 wt. % lubricant comprising an oil of lubricating
viscosity, about 0.001 to about 0.05 wt. % detergent comprising an
alkaline earth metal-containing compound, and about 1 ppm to about
10 ppm Mo from a molybdenum source. An amount of the molybdenum
source is provided adequate for the purpose of increasing
detergency upon interaction with the detergent in the fuel
composition before, during and/or after combustion. That amount of
Mo needed for that purpose can vary, but generally will be in an
amount effective to deliver Mo in amount of about 1 ppm to about 10
ppm. Other performance enhancing additives optionally can be
included as well in the fuel composition to the extent they do not
interfere with the interaction of the molybdenum and detergent as
described herein. In one embodiment, the combustion apparatus
including the two-stroke engine combusting the fuel composition
described herein has an after-treatment system selected from the
group consisting of a diesel oxidation catalyst, a catalyzed diesel
particulate matter filter, and a continuously regenerating
technology diesel particulate filter. The two-stroke engine may be
a gasoline combustion engine or a diesel combustion engine. The
apparatus having the two-stroke engine operable using the fuel
composition described herein may be, for example, a motorcycle, a
moped, a snow mobile, an all terrain vehicle, tractor, mining
equipment, construction equipment, a marine outboard motor, a lawn
mower, a chain saw, a pump, an electrical generator, a garden
tiller, a landscaping hedge trimmer, back pack blower, and so
forth.
[0020] It is to be understood that both the foregoing general
description and the following detailed description are exemplary
and explanatory only and are intended to provide further
explanation of the present invention, as claimed.
DETAILED DESCRIPTION OF THE INVENTION
[0021] The present invention relates to a fuel composition, and a
method and an apparatus for combusting it in a two-stroke engine,
and in which molybdenum delivered from the fuel will interact with
alkaline earth metal originating from a detergent or other
co-ingredient of the fuel effective to increase detergency without
increasing the level of alkaline earth metal or compounds present
in the fuel or combustion products thereof. In this manner, the
engine operates more cleanly and efficiently without increasing the
risk of harmful alkaline earth materials and compounds thereof
blocking and poisoning catalysts, sensors and/or automotive
on-board diagnostic devices. That is, the molybdenum acts as a
significant detergency booster without causing an adverse effect
upon emission control systems. In another embodiment, the present
invention makes it possible to maintain adequate detergency while
decreasing the level of alkaline earth metal-based detergents
needed in a two-stroke fuel composition. That is, since the
molybdenum added will boost the detergent effect of the alkaline
earth metal-containing detergent, the amount of alkaline earth
metal-containing detergent needed is reduced for a given minimal
desired level of detergency. The resulting reduced level of
alkaline earth metal translates into the reduced presence of
alkaline earth metal by-product compounds, such as sulphates
thereof, in the exhaust stream such that less blocking and other
contaminant-related problems occur on exhaust emissions
after-treatment devices and/or control devices. These beneficial
results include maintaining catalyst performance, maintaining
sensor performance, maintaining LNT performance, and maintaining
diesel particulate filter (DPF) performance for longer periods of
time. The present invention therefore also can be used to improve
durability of exhaust after-treatment systems.
[0022] In one embodiment of this invention, a fuel-oil mixture is
introduced into the combustion chamber and burned in a two-stroke
engine, and the combustion products thereof pass over a catalyst of
an oxidation catalyst or catalyzed particulate matter filter where
alkaline earth metal can deposit onto the catalyst surface, such as
in the form of an alkaline earth metal sulphate. The formation of
this alkaline earth sulfate and the like, if not inhibited or not
controlled while other enhancements are made in the fuel
performance, then mechanically blocks the catalyst, preventing it
from functioning properly. The inclusion of a small amount of
molybdenum has been discovered to increase the detergency of the
fuel composition containing an alkaline earth metal-containing
compound without causing an increase in the amount of alkaline
earth metal in the formulation and formation and build up of
alkaline earth sulphate on the catalyst. By impeding the formation
of impermeable or permeability-reducing glazes on the catalyst, the
catalyst life can be extended by the present invention. Molybdenum
is present in the fuel composition as an oil-soluble and
fuel-soluble additive that can volatilise and thereby be present in
the combustion chamber and exhaust stream. By "molybdenum" herein
is meant any molybdenum compound, source or material, including but
not limited to molybdenum trioxide, mono-nuclear and di-nuclear and
tri-nuclear molybdenum sulfonate, molybdenum phenate, molybdenum
salicylate, molybdenum carboxylates, molybdenum dithiocarbamates,
neutral and overbased molybdenum salicylates, neutral and overbased
molybdenum phenates, neutral and overbased NT molybdenum
sulfonates, ammonium molybdate, sodium molybdate, potassium
molybdate, and molybdenum halides, compounds derived from
molybdenum reacted with amines and alcohols, and combinations and
mixtures thereof. In one particular embodiment, the molybdenum
source comprises an organomolybdenum complex prepared by reacting
fatty oil, diethanolamine, and a molybdenum source. Other suitable
molybdenum sources includes of molybdenum complexes described in
U.S. Pat. Nos. 6,509,303, 6,528,461, and 6,528,463, which teachings
are incorporated herein by reference.
[0023] Examples of useful commercial oil soluble molybdenum
compounds are Sakura-Lube 100, Sakura-Lube 155, Sakura-Lube 165,
and Sakura-Lube 180 from Asahi Denka Kogyo K. K., Molyvan.RTM. A,
Molyvan.RTM. 807 and Molyvan.RTM. 822 from R. T. Vanderbilt
Company, and Naugalube MolyFM from Crompton Corporation. Examples
of commercial sulfur- and phosphorus-free oil soluble molybdenum
compounds or complexes are Sakura-Lube 700 from Asahi Denka Kogyo
K. K., and Molyvan.RTM. 856 B and Molyvan.RTM. 855 from R. T.
Vanderbilt Company, Inc.
[0024] The fuel composition also includes a detergent compound that
is an alkaline earth metal-containing compound. These detergents
are metallic additives containing charged polar groups, such as
sulfonates, phenates, carboxylates, or phosphonates, with
aliphatic, cycloaliphatic, or alkylaromatic chains, and several
metal ions that will include at least one alkaline earth metal ion.
These detergents function by lifting deposits in the combustion
chamber, which can include related injection valves, injection
ports, and so forth. The alkaline earth metal-containing detergent
compound includes calcium, magnesium, barium and strontium salts
imparting detergent action in a fuel-oil composition. Examples
include neutral and overbased alkaline earth metal sulphonates, and
neutral and overbased alkaline earth metal phenates. These
detergents may include alkaline earth metal salts of petroleum
sulphonic acids and long chain mono- or di-alkylarylsulphonic acids
with each alkyl group comprising 12-18 carbon atoms and the aryl
group being benzyl, tolyl, and xylyl. These detergents also may
include alkaline earth metal phenates of alkylphenols and
alcylmercaptophenols in which the linear or branched alkyl groups
comprising from 4-50 carbon atoms and more particularly from 8-20
carbon atoms.
[0025] Particular examples of the detergent include salts such as
selected from the group consisting of neutral calcium sulphonate,
overbased calcium sulphonate, neutral calcium phenate, overbased
calcium phenate, neutral magnesium sulphonate, neutral magnesium
sulphonate, overbased magnesium phenate, overbased magnesium
phenate, or combinations and mixtures thereof. In one preferred
embodiment, the detergent comprises a neutral calcium salt.
[0026] The combustible hydrocarbonaceous fuel and lubricant of
lubricating viscosity are not particularly limited to the extent
they can be proportioned with the alkaline earth metal-containing
detergent compound and the molybdenum source to function as
necessary in a two-stroke engine.
[0027] By "hydrocarbonaceous fuel" herein means a liquid fuel that
can introduced into a combustion chamber and combusted in a
two-stroke engine. Examples include, but are not limited to, diesel
fuels, biodiesel fuels, biodiesel-derived fuels, alcohols, ethers,
kerosene, jet fuels, low sulfur fuels, synthetic fuels, such as
Fischer-Tropsch fuels, liquid petroleum gas, fuels derived from
coal, genetically engineered biofuels and crops and extracts
therefrom, natural gas, propane, butane, unleaded motor gasolines,
aviation gasolines, and so-called reformulated gasolines which
typically contain both hydrocarbons of the gasoline boiling range
and fuel-soluble oxygenated blending agents, such as alcohols,
ethers and other suitable oxygen-containing organic compounds. In
one embodiment, it is preferred that the hydrocarbonaceous fuel is
substantially sulfur-free, by which is meant a sulfur content not
to exceed on average about 30 ppm of the fuel.
[0028] The oil of lubricating viscosity generally is a base oil. It
can be a mineral base oil or synthetic base oil, or a combination
thereof, supplied in fluid form. The mineral base oil can be a
high-viscosity mineral oil, medium mineral oil, or combination
thereof. A suitable high viscosity mineral oil includes
paraffinic-based oil comprising naphthenic and aromatic groups.
Heavy neutral base oils can be used. This heavy mineral oil may
have a viscosity of about 75-150 cSt at 40.degree. C. and about
8-16 cSt at 1000 cSt (D445). It generally also will have a flash
point about 250.degree. C., a pour point of less than about
12.degree. C., and a specific gravity of about 0.9 at 16.degree. C.
(D1198). Medium neutral base oils can be used. This medium mineral
oil may have a viscosity of about 20-60 cSt at 40.degree. C. and
about 4-8 cSt at 1000 cSt (D445). It generally also will have a
flash point about 220.degree. C., a pour point of less than about
12.degree. C., and a specific gravity of about 0.9 at 16.degree. C.
(DI 298).
[0029] Synthetic base fluid oils can be selected, for example, from
the group consisting of paraffinic, naphthenic, aromatic,
poly-alpha-olefins, synthetic esters, and polyol esters, and
mixtures thereof. In a preferred embodiment, the base oil contains
less than or equal to 0.03 wt. % sulfur, and greater than or equal
to 90 wt. % saturates, and has a viscosity index greater than or
equal to 80 and less than or equal to 120. In another embodiment,
the oil contains less than or equal to 0.03 wt. % sulfur, and
greater than or equal to 90 wt. % saturates, and has a viscosity
index greater than or equal to 120. In a more preferred embodiment,
the base oil is substantially sulfur-free.
[0030] In one embodiment of this invention, the fuel composition
having these advantages and capabilities comprises about 95 to
about 99 wt. % combustible hydrocarbonaceous liquid fuel, about 1
to about 5 wt. % lubricant comprising an oil of lubricating
viscosity, about 0.001 to about 0.05 wt. % detergent comprising an
alkaline earth metal compound, and about 1 ppm to about 10 ppm Mo
from a molybdenum source. An amount of the molybdenum source is
provided adequate for the purpose of increasing detergency upon
interaction with the detergent in the fuel composition before,
during and/or after combustion. That amount of Mo can vary but
generally will be in an amount effective to deliver Mo in amount of
about 1 ppm to about 10 ppm.
[0031] These four important fuel-oil mixture ingredients, i.e.,
fuel, oil, detergent comprising alkaline earth metal-containing
compound, and molybdenum source, can be combined in any convenient
order or manner. For example, the oil, detergent comprising
alkaline earth metal-containing compound, and molybdenum source can
be combined as an oil concentrate or package, which in turn is
combined with the fuel package in a prescribed ratio to provide the
fuel composition (i.e., the fuel-oil mixture).
[0032] In addition to the fuel composition ingredients and
additives mentioned thus far, there may be a need or advantage for
other supplemental additives that perform other specific functions
not provided at all or sufficiently by the main components. These
supplemental additives include, for example, ashless or polymeric
dispersants, co-dispersants, antioxidants, lubricity solvents,
viscosity index improvers, pour point depressants, corrosion
inhibitors, rust inhibitors, foam inhibitors, frictional modifiers,
and other additives including those commonly used in the fuel
package, oil package, or both parts of fuel-oil compositions for
two-stroke engines. These various additives can be added into the
respective oil or fuel packages before their admixture, or added
after admixture of fuel and oil package components has been
commenced. The additives must be dissolvable or dispersible the
fuel package or oil package, or the fuel composition, and it must
be stable in the fuel composition.
[0033] For example, dispersants can be introduced, for example, in
the oil package of the fuel composition. Ashless dispersants
include N-substituted long chain alkenyl succinimides, Mannich
bases, and so forth, including those known and used generally in
combustible fuel-oil compositions. Polymeric dispersants generally
are hydrocarbon-based polymers, which contain polar functionality.
Examples include, for example, materials that include, as their
main component, one or more of mono-, bi- or boronated polybutene
succinimides, borated or non-borated polybutene anines and
polybutene succinimides. If used, the total amount of dispersant in
the fuel composition can be in the range of about 2-15 wt. %.
[0034] Lubricity solvents can be used including a suitable solvent
having a flash point of higher than 100.degree. F., a boiling point
of lower than 570.degree. F., and a distillation range of from
about 360-572.degree. F. The solvent can be introduced, for
example, in the oil package. If used, the amount of solvent may
range from about 5-30 wt. % of the total fuel composition.
[0035] An antifoaming agent can be included. The antifoaming agent
generally will be used in an amount of less than 1 wt. %. The
antifoaming agent can be introduced, for example, in the oil
package.
[0036] Oxygenates used in the oil package can comprise phenolic
antioxidants such as hindered phenols, or an aminic antioxidant
such as alkyl diphenylwanine.
[0037] Oxygenates suitable for use in the fuels contained in the
fuel compositions of the present invention include methanol,
ethanol, isopropanol, t-butanol, mixed alcohols, methyl tertiary
butyl ether, tertiary amyl methyl ether, ethyl tertiary butyl ether
and mixed ethers. Oxygenates, when used, will normally be present
in the reformulated gasoline fuel in an amount below about 25% by
volume, and preferably in an amount that provides an oxygen content
in the overall fuel in the range of about 0.5 to about 5 percent by
volume.
[0038] The preparation method of the two-stroke fuel composition
can be as follows. In preparing the oil package, the base oil and
any solvent are mixed at room temperature. The detergent,
molybdenum source, and any other oil additives (such as
dispersants) are blended and preheated, such as to a temperature of
about 50-70.degree. C., and then mixed into the base oil with
mixing. The resulting oil package can be combined with mixing with
the fuel package, including any fuel additives previously added to
it, in a prescribed ratio to obtain the compositions described
herein. A substantially uniform resulting fuel-oil mixture is
preferred. This fuel-oil mixture usually is prepared before
introducing the fuel composition components into the two-stroke
engine. For example, the admixture could be performed before it is
supplied to the fuel tank or in the fuel tank itself. For purposes
herein, by "combustion system" and "apparatus" herein is meant, for
example and not by limitation herein, any diesel-electric hybrid
vehicle, a gasoline-electric hybrid vehicle, a two-stroke engine,
any and all burners or combustion units, including for example and
without limitation herein, stationary burners, waste incinerators,
diesel fuel burners, diesel fuel engines, automotive diesel
engines, gasoline fuel burners, gasoline fuel engines, power plant
generators, and the like.
[0039] The hydrocarbonaceous fuel combustion systems that may
benefit from the present invention include all combustion units,
systems, devices, and/or engines that burn fuels. By "combustion
system" herein is also meant any and all internal and external
combustion devices, machines, engines, turbine engines, jet
engines, boilers, incinerators, evaporative burners, plasma burner
systems, plasma arc, stationary burners, and the like which can
combust or in which can be combusted a hydrocarbonaceous fuel.
[0040] By "after treatment system" or "after treatment device"
herein is meant any system or device which contacts the combustion
product(s) from a combustion chamber in a manner designed to
oxidize, reduce or otherwise treat the combustion product(s).
Examples, but not by way of limitations herein, of such after
treatment systems include a vehicular oxidation catalytic
converter, lean NO.sub.X traps, catalyzed diesel particulate filter
("C-DPF") and a continuously regenerating technology diesel
particulate filter. "After treatment system" also includes
associated sensors like O.sub.2 sensors and NO.sub.x sensors.
Analogous gasoline combustion after treatment systems are known and
are included herein as deriving benefit from the present
invention.
[0041] The practice and advantages of this invention are
demonstrated by the following examples, which are presented for
purposes of illustration and not limitation. Unless indicated
otherwise, all amounts, percentages, ratios, and the like, are by
weight.
EXAMPLE
[0042] Detergency tests were carried out using a modified ISO EGD 3
hour detergency test procedure. A commercial oil from the market
was first run against the standard JATRE 1 reference oil and then
the commercial oil was used as the reference for which the
candidates were compared. The testing evaluated the high
temperature detergency of two-stroke spark ignition gasoline engine
lubricants.
[0043] The test was carried out on a 50 cc air cooled motor cycle
engine for a specified period of time to evaluate ring sticking,
piston deposits and cylinder head deposits. A reference was carried
out at the start of each day and usually two candidates were
evaluated each day. For these experiments:
[0044] the detergent used was calcium sulphonate;
[0045] the dispersant was a succinimide dispersant;
[0046] the antifoarning additive was a silicon based antifoaming
agent;
[0047] the Mo source was Molyvan.RTM. 855, R. T. Vanderbilt;
[0048] Antioxidant 1 (AO 1) was a sulphur based antioxidant;
[0049] Antioxidant 2 (AO2) was an amine type antioxidant; and
[0050] Antioxidant 3 (AO3) was a phenolic antioxidant.
[0051] The detergency index and piston skirt index values reported
in Table 1 were generated by comparisons against a commercial
oil.
1TABLE 1 Packages Sample Run Ingredient A1 B1 C1 D1 E1 F1 G1 H1 I1
Detergent 16.04 8.02 -- 8.02 -- -- 8.02 -- 8.02 AO1 2.33 2.33 2.33
2.33 2.33 2.33 2.33 2.33 2.33 Dispersant 70 70 70 70 70 70 70 70 70
AO2 1.33 1.33 1.33 1.33 1.33 1.33 1.33 1.33 1.33 Process Oil 10.26
18.28 26.3 16.78 24.8 23.8 15.78 22.3 14.28 Antifoam 0.04 0.04 0.04
0.04 0.04 0.04 0.04 0.04 0.04 MoSource 0 0 0 1.5 1.5 0 0 1.5 1.5
AO3 0 0 0 0 0 2.5 2.5 2.5 2.5 TOTAL 100 100 100 100 100 100 100 100
100 Package Full Half No Half No Ca + No Ca + Half No Ca + Half
Description Ca Ca Ca Ca + Mo AO3 Ca + Mo + Ca + Mo AO3 AO3 Mo + AO3
Package 8 8 8 8 8 8 8 8 8 Priorlube 5 5 5 5 5 5 5 5 5 1929 Exxsol
D80 20 20 20 20 20 20 20 20 20 Napvis D10 25 25 25 25 25 25 25 25
25 Mobil 19 19 19 19 19 19 19 19 19 Jurong 500SN Mobil 23 23 23 23
23 23 23 23 23 Jurong 150SN Detergency 117 113 94 136 135 121 100
122 149 Index Piston Skirt 101 97 91 103 86 86 97 93 100 Index
Catalyst Blocking Kv 100, cSt 10.05 9.84 9.69 9.81 9.69 9.68 9.83
9.75 9.85 Kv 40, cSt 64.31 62.2 61.38 62 60.92 60.96 62.02 61.53
62.27 VI 142 142 141 142 142 142 143 142 143 Ca, % .0347 .0181
.0009 .0175 .0009 .0006 .0179 .0009 .0165 P, % .0009 .0012 .0009
.0014 .0012 .0008 .0012 .0016 .001 S, % .0826 .0641 .0448 .064 .44
.0429 .0639 448 .0583 Mo, % 0 0 0 .0092 .0091 0 0 .0091 .09
[0052] These data results in Table 1 demonstrate that the addition
of molybdenum to the fuel-oil compositions effectively increased
detergency in a significant manner without an attendant undesirable
increase in the contaminant levels of alkaline earth metal and
compounds thereof in the emissions stream. The molybdenum acted as
a detergency booster without causing an adverse effect upon
emission control systems.
[0053] Other embodiments of the present invention will be apparent
to those skilled in the art from consideration of the specification
and practice of the invention disclosed herein. It is intended that
the specification be considered as exemplary only, with a true
scope and spirit of the invention being indicated by the following
claims.
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