U.S. patent application number 10/571741 was filed with the patent office on 2007-02-22 for low temperature operable fatty acid ester fuel composition and method thereof.
Invention is credited to Robert H. Barbour, Carlos L. Cerda de Groote, David R. Forester, David Price, Barton J. Schober.
Application Number | 20070039239 10/571741 |
Document ID | / |
Family ID | 34375317 |
Filed Date | 2007-02-22 |
United States Patent
Application |
20070039239 |
Kind Code |
A1 |
Forester; David R. ; et
al. |
February 22, 2007 |
Low temperature operable fatty acid ester fuel composition and
method thereof
Abstract
A fuel composition comprises (A) a major amount of a fatty
carboxylic acid ester composition from at least one naturally
occurring triglyceride and (B) a minor amount of a low temperature
operability composition. A method for improving the low temperature
operability of a fuel composition comprises admixing (A) with a low
temperature improving amount of (B). The fuel composition is
derived from a renewable resource and is especially useful in
internal combustion engines such as compression-ignited diesel
engines.
Inventors: |
Forester; David R.;
(Weatherford, TX) ; Price; David; (Littleover,
GB) ; Barbour; Robert H.; (Ashbourne, GB) ;
Cerda de Groote; Carlos L.; (Lakewood, OH) ; Schober;
Barton J.; (Perry, OH) |
Correspondence
Address: |
THE LUBRIZOL CORPORATION;ATTN: DOCKET CLERK, PATENT DEPT.
29400 LAKELAND BLVD.
WICKLIFFE
OH
44092
US
|
Family ID: |
34375317 |
Appl. No.: |
10/571741 |
Filed: |
September 14, 2004 |
PCT Filed: |
September 14, 2004 |
PCT NO: |
PCT/US04/29979 |
371 Date: |
October 19, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60503150 |
Sep 15, 2003 |
|
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|
Current U.S.
Class: |
44/307 ;
44/393 |
Current CPC
Class: |
C10L 1/19 20130101; Y02E
50/10 20130101; C10L 1/1963 20130101; C10L 1/1883 20130101; C10L
1/196 20130101; C10L 1/1881 20130101; C10L 1/1905 20130101; C10L
1/1824 20130101; C10L 1/026 20130101; C10L 1/1966 20130101; Y02E
50/13 20130101; C10L 1/1608 20130101; C10L 1/1802 20130101; C10L
1/1817 20130101; C10L 1/143 20130101 |
Class at
Publication: |
044/307 ;
044/393 |
International
Class: |
C10L 1/00 20060101
C10L001/00 |
Claims
1. A fuel composition for an internal combustion engine,
comprising: (A) a major amount of a fatty carboxylic acid ester
composition from the transesterification of at least one naturally
occurring triglyceride; and (B) a minor amount of a low temperature
operability composition comprising an esterified copolymer of an
alpha-olefin or styrene and an alpha, beta-unsaturated
monocarboxylic or dicarboxylic acid or anhydride, wherein the
copolymer of (B) is esterified with a mixture of two or more
alcohols having 5 to 28 carbon atoms wherein the mixture of the two
or more alcohols has an average carbon length of 9.2 to 11.8 on a
weight % basis.
2. The fuel composition of claim 1 wherein the naturally occurring
triglyceride is a vegetable oil.
3. The fuel composition of claim 2 wherein the vegetable oil is a
rapeseed oil, a soybean oil, a palm oil, or a mixture thereof.
4. The fuel composition of claim 1 wherein the naturally occurring
triglyceride is transesterified with at least one monohydric
alcohol having 1 to 22 carbon atoms.
5. The fuel composition of claim 3 wherein the rapeseed oil, the
soybean oil, the palm oil, or the mixture thereof is
transesterified with methanol.
6. The fuel composition of claim 1 wherein the alpha,
beta-unsaturated monocarboxylic or dicarboxylic acid or anhydride
is maleic acid, maleic anhydride, fumaric acid, itaconic acid,
itaconic anhydride, acrylic acid, or methacrylic acid.
7. The fuel composition of claim 6 wherein the copolymer of (B) is
formed from styrene and maleic anhydride.
8. The fuel composition of claim 7 wherein the copolymer of (B)
prior to esterification has a reduced specific viscosity of 0.05 to
2.
9. The fuel composition of claim 1 wherein the copolymer of (B)
further comprises an additional comonomer selected from the group
consisting of a C.sub.1-4 alkyl alpha, beta-unsaturated
monocarboxylic acid ester, a di(C.sub.1-4 alkyl) alpha,
beta-unsaturated dicarboxylic acid ester, a vinyl monocarboxylic
acid ester, an alkyl vinyl ether, and a mixture thereof.
10. The fuel composition of claim 9 wherein the additional
comonomer is methyl methacrylate.
11. The fuel composition of claim 1 wherein the copolymer of (B) is
esterified with a mixture of two or more alcohols having 5 to 20
carbon atoms.
12. The fuel composition of claim 1 wherein the esterified
copolymer of (B) is further reacted with an amine having only one
amino group that is a primary or a secondary amino group.
13. The fuel composition of claim 1 wherein the ester composition
(A) is present in the fuel composition from 30 to 99.99% by weight
and the low temperature operability composition (B) is present in
the fuel composition from 100 to 10,000 ppm by weight.
14. The fuel composition of claim 1, further comprising: (C) at
least one additional fuel additive.
15. The fuel composition of claim 1, further comprising: (D) a
normally liquid fuel.
16. The fuel composition of claim 15 wherein the normally liquid
fuel is a diesel fuel.
17. A method for improving the low temperature operability of a
fuel composition, comprising: admixing the ester composition (A)
with a low temperature improving amount of the composition (B) of
claim 1.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention involves a fuel composition that
comprises a fatty carboxylic acid ester from at least one naturally
occurring triglyceride and a low temperature operability
composition. The low temperature operability composition improves
the low temperature operability of the fuel composition.
[0003] 2. Description of the Related Art
[0004] Esterified fatty carboxylic acids, where the fatty
carboxylic acids are derived from naturally occurring
triglycerides, can be used as a partial or total replacement for a
petroleum distillate and/or oxygenate in fuels for combustion in
internal combustion engines and furnaces for locomotion, heating
and power generation. The use of fatty carboxylic acid esters,
which are derived from naturally occurring triglycerides, for
combustion in fuels is particularly advantageous since naturally
occurring triglycerides are renewable resources. Fuel compositions
containing a major amount of a fatty carboxylic acid ester
composition, about 30 wt. % or more of the ester composition,
usually require a higher temperature for operability in terms of
flow and filterability.
[0005] Erner in U.S. Pat. No. 4,364,743 discloses a synthetic fuel
of fatty acid esters that provides a novel source of energy when
burned alone or in combination with other known fuels such as
diesel oil, heating, etc. in oil-burning devices.
[0006] Tack et al. in U.S. Pat. No. 4,863,486 disclose middle
distillate fuel compositions with improved low temperature
properties from polymers or copolymers having a narrow carbon
number range of alkyl ester groups and containing a n-alkyl ester
of a mono-ethylenically unsaturated C.sub.4 to C.sub.8 mono- or
dicarboxylic acid wherein the average number of carbon atoms in the
n-alkyl groups is from 12 to 14.
[0007] Dishong et al. in U.S. Pat. No. 5,157,088 disclose low
molecular weight terpolymers containing nitrogen and ester groups
where the terpolymers are shear stable and maintain desired high
and low temperature viscosity characteristics in functional fluids
such as automotive power transmission fluids.
[0008] Lal in European Patent Publication No. EP626442 discloses
pour point treated fatty acid esters as biodegradable combustion
engine fuels.
[0009] Corkwell et al. in U.S. patent application Ser. No.
10/640,448, filed 13 Aug. 2003, disclose a low temperature stable
concentrate composition containing a fatty carboxylic acid based
composition and a low temperature stability improving composition,
and also discloses a fuel composition and method that employs the
concentrate composition.
[0010] It has now been found that certain low temperature
operability compositions are extremely effective in improving the
operability temperature of fuel compositions containing fatty
carboxylic acid ester compositions derived from naturally occurring
triglycerides by reducing the temperature required for operation in
terms of flow and filterability, thus making these fuel
compositions useful in the colder climates of Asia, Europe and
North America.
SUMMARY OF THE INVENTION
[0011] An object of the present invention is to provide a low
temperature operable fuel composition containing a composition from
a renewable resource for use in an internal combustion engine
and/or furnace for locomotion, heating and power generation.
[0012] Another object of the present invention is to provide a low
temperature operable fuel composition containing a composition from
a renewable resource for use in a spark-ignited and/or
compression-ignited internal combustion engine.
[0013] Still a further object of this invention is a method to
improve the low temperature operability of a fuel composition
containing a composition from a renewable resource.
[0014] Additional objects and advantages of the present invention
will be set forth in the Detailed Description which follows and, in
part, will be obvious from the Detailed Description or may be
learned by the practice of the invention. The objects and
advantages of the invention may be realized by means of the
instrumentalities and combinations pointed out in the appended
claims.
[0015] To achieve the foregoing objects in accordance with the
present invention as described and claimed herein, a fuel
composition for an internal combustion engine comprises (A) a major
amount of a fatty carboxylic acid ester composition from the
transesterification of at least one naturally occurring
triglyceride, and (B) a minor amount of a low temperature
operability composition comprising an esterified copolymer of an
alpha-olefin or styrene and an alpha, beta-unsaturated
monocarboxylic or dicarboxylic acid or anhydride, wherein the
copolymer of (B) is esterified with a mixture of two or more
alcohols having 5 to 28 carbon atoms wherein the mixture of the two
or more alcohols has an average carbon length of 9.2 to 11.8 on a
weight % basis.
[0016] In an embodiment of the invention the above described fuel
composition comprises the fatty carboxylic acid ester composition
of (A) and the low temperature operability composition of (B)
comprising the esterified copolymer from two comonomers wherein the
esterified copolymer further comprises an additional comonomer
selected from the group consisting of a C.sub.1-4 alkyl alpha,
beta-unsaturated monocarboxylic acid ester, a di(C.sub.1-4 alkyl)
alpha, beta-unsaturated dicarboxylic acid ester, a vinyl
monocarboxylic acid ester, an alkyl vinyl ether, and a mixture
thereof.
[0017] In a further embodiment of this invention a method to
improve the low temperature operability of the above-described fuel
composition for an internal combustion engine comprises admixing
the ester composition of (A) with a low temperature improving
amount of the low temperature operability composition of (B).
DETAILED DESCRIPTION OF THE INVENTION
[0018] A fuel composition of the present invention comprises (A) a
major amount of a fatty carboxylic acid ester composition derived
from at least one naturally occurring triglyceride, and (B) a minor
amount of a low temperature operability composition comprising an
esterified copolymer of an alpha-olefin or styrene and an alpha,
beta-unsaturated monocarboxylic or dicarboxylic acid or anhydride,
wherein the copolymer of (B) is esterified with a mixture of two or
more alcohols having 5 to 28 carbon atoms wherein the mixture of
the two or more alcohols has an average carbon length of 9.2 to
11.8 on a weight % basis.
[0019] The naturally occurring triglycerides of the present
invention can be obtained from a renewable resource to include
vegetable or plant fats and oils, animal fats and oils, and
mixtures thereof. Vegetable or plant fats and oils include rapeseed
oil, soybean oil, palm oil, corn oil, coconut oil, cottonseed oil,
peanut oil, safflower oil, linseed oil, tung oil, castor oil,
sunflower oil, meadowfoam oil, and mixtures thereof. In an
embodiment of this invention the naturally occurring triglyceride
is a rapeseed oil, a soybean oil, a palm oil, or a mixture thereof.
Animal fats and oils include lard, lard oil, tallow, various fish
oils, and mixtures thereof.
[0020] The fatty carboxylic acid ester composition (A) of the
present invention can be derived from at least one naturally
occurring triglyceride, as described above, by transesterification
of the triglyceride with an alcohol. In an embodiment of the
invention the alcohol is at least one monohydric alcohol. The
alcohol can be linear, branched, cyclic, or a mixture thereof. The
alcohol can have 1 to 22 carbon atoms, and in other instances can
have 1 to 18 carbon atoms, and 1 to 10 carbon atoms. Useful
alcohols for transesterifying naturally occurring triglycerides
include methanol, ethanol, propanol and butanol. The
transesterification can be done using either an acid or base
catalyst. Acid catalysts include dry hydrogen chloride and sulfuric
acid. Base catalysts include alkali metal and alkaline earth metal
alkoxides such as sodium methoxide, alkali metal hydroxides such as
potassium hydroxide, and titanium alkoxides such as titanium
tetraisopropoxide. The transesterification is generally run using
an excess of the alcohol reactant and/or removing one of the
products to drive the reaction toward completion. The fatty
carboxylic acid esters from the transesterification of the
triglyceride are usually isolated from the glycerol by-product and
any excess alcohol reactant by physical separation and distillation
or fractional distillation. In an embodiment of the invention
rapeseed oil, soybean oil, palm oil, or a mixture thereof is
transesterified with an excess of methyl alcohol using a sodium
methoxide catalyst, as described in U.S. Pat. No. 4,364,743 and
European Patent Publication No. EP626442, to form fatty acid methyl
esters which can be used in a fuel composition for an internal
combustion engine to include a compression-ignited engine. In
another embodiment of the invention fatty acid methyl esters are
prepared by separate transesterifications of different
triglycerides and then each fatty acid methyl ester can be used in
a fuel composition as a single component or two or more of the
fatty acid methyl esters can be used as a blend in a fuel
composition. Fatty acid methyl esters such as rapeseed methyl
ester, soy methyl ester and palm methyl ester are commercially
available and are referred to as biodiesel fuels since they
originate from naturally occurring triglycerides which are
renewable resources.
[0021] The fatty carboxylic acid ester composition (A) of this
invention can also be derived from at least one naturally occurring
triglyceride, as described above, by esterification of one or more
fatty carboxylic acids obtained from at least one naturally
occurring triglyceride. A fatty carboxylic acid or mixture of fatty
carboxylic acids can be obtained from naturally occurring
triglycerides by a saponification process and are commercially
available. The fatty carboxylic acid or mixture of acids, obtained
by saponification of at least one naturally occurring triglyceride,
can be saturated, unsaturated to include mono- and polyunsaturates,
or a mixture thereof. The fatty carboxylic acid or mixture of acids
can be linear, branched or a mixture thereof, but usually they are
linear. The fatty carboxylic acid or mixture of acids can have 4 to
24 carbon atoms, and in other instances 8 to 22 carbon atoms, and
10 to 22 carbon atoms. The fatty carboxylic acid or mixture of
acids can be esterified with an excess of an alcohol, where the
alcohol is as described above for the transesterification of a
triglyceride, using an acid catalyst such as sulfuric acid and
removing the water by-product by azeotropic distillation usually
with an aromatic solvent. The sulfuric acid catalyst in the crude
product can be neutralized, and the ester or esters can be
recovered by fractional distillation as described in the
esterification procedure in U.S. Pat. No. 4,364,743. Alternatively,
esterified fatty carboxylic acids or mixtures of esterified fatty
carboxylic acids from naturally occurring triglycerides are
commercially available. In an embodiment of the invention the fatty
carboxylic acid or mixture of fatty carboxylic acids are esterified
with an olefin such as ethylene.
[0022] The low temperature operability composition (B) of the
present invention comprises an esterified copolymer of an
alpha-olefin or styrene and an alpha, beta-unsaturated
monocarboxylic or dicarboxylic acid or anhydride. The alpha-olefin
can have 2 to 30 carbon atoms, and in other instances can have 2 to
24 carbon atoms, and 2 to 20 carbon atoms. Useful alpha-olefins
include ethylene, propylene, 1-butene, isobutylene, 1-hexene,
1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene and
1-octadecene. The alpha, beta-unsaturated monocarboxylic acid or
anhydride can have 3 or more carbon atoms, and in other instances
can have 3 to 6 carbon atoms, and 3 to 5 carbon atoms. Useful
alpha, beta-unsaturated monocarboxylic acids include acrylic acid,
methacrylic acid, crotonic acid and 2-pentenoic acid. The alpha,
beta-unsaturated dicarboxylic acid or anhydride can have 4 or more
carbon atoms, and in other instances can have 4 to 6 carbon atoms,
and 4 to 5 carbon atoms. Useful alpha, beta-unsaturated
dicarboxylic acids and anhydrides include maleic acid, maleic
anhydride, fumaric acid, itaconic acid and itaconic anhydride. In
an embodiment of the invention the alpha, beta-unsaturated
monocarboxylic or dicarboxylic acid or anhydride is maleic acid,
maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride,
acrylic acid, or methacrylic acid. In another embodiment of the
invention the low temperature operability composition (B) comprises
an esterified copolymer where the copolymer is formed from styrene
and maleic anhydride. The copolymer of (B) can be prepared by a
free radical polymerization of its two comonomers in a mole ratio
of 0.25:1 to 1:0.25, and in other instances of 0.5:1 to 1:0.5,
0.75:1 to 1:0.75, and 1:1. The copolymer of (B) prior to
esterification can have a reduced specific viscosity of 0.05 to 2,
and in other embodiments can have a reduced specific viscosity of
0.05 to 1, and 0.07 to 0.8. The reduced specific viscosity of a
polymer and its relation to the molecular weight of that polymer
are defined and described in U.S. Pat. No. 5,413,725 and in
"Principles of Polymer Chemistry", Paul J. Flory, 1953 edition,
page 308 and following pages. The copolymer of (B) is esterified
with a mixture of two or more alcohols. The alcohols can be linear,
branched, or a mixture thereof, but they are generally linear
alcohols to include commercially available alcohols such as
synthetic primary straight-chain alcohols made by Ziegler-type
reaction of aluminum alkyls with ethane and hydrogen. The alcohols
used to esterify the copolymer of (B) can have 5 to 28 carbon
atoms, and in other embodiments can have 5 to 20 carbon atoms, 5 to
18 carbon atoms, and 5 to 16 carbon atoms. The copolymer of (B) can
be esterified by the above described mixture of two or more
alcohols to 50% or greater, and in other instances can be
esterified to 65% or greater, 80% or greater, and 95% or greater.
The copolymer of (B) can be esterified with a mixture of two or
more alcohols or a copolymer of (B) can be esterified separately
with each alcohol and the separately esterified copolymers
combined, but usually the copolymer of (B) is esterified with a
mixture of alcohols. In an embodiment of the present invention the
copolymer of (B) is esterified with the above described mixture of
two or more alcohols wherein the mixture of two or more alcohols
has an average carbon length of 9.2 to 11.8 on a weight % basis,
and in other embodiments has an average carbon length on a weight %
basis of 9.8 to 11.7, 10.4 to 11.6, and 10.7 to 11.8. In another
embodiment of the invention the esterification of the copolymer (B)
with the above described mixture of two or more alcohols can be
driven toward completion by including up to 20 mole %, based on
carbonyl group equivalents, of lower molecular weight alcohols
having 1 to 4 carbon atoms, and in other embodiments up to 15 mole
% and up to 10 mole % of the lower molecular weight alcohols can be
included.
[0023] In an embodiment of the invention the esterified copolymer
of (B) can have an unesterified portion remaining which can be
reacted with up to 6 mole % of an amine, and in other instances up
to 4 mole % and up to 2 mole % of the amine. The amine can be a
monoamine or a polyamine, and usually the amine has only one amino
group that is a primary or a secondary amino group. Examples of
useful amines include ammonia, butylamine, diethylamine,
N,N-dimethylethylenediamine, and aminoalkyl substituted
heterocyclic compounds such as 4-(3-aminopropyl)morpholine.
[0024] In another embodiment of the invention the copolymer of (B),
as described above, can further comprise an additional comonomer
selected from the group consisting of a C.sub.1-4 alkyl alpha,
beta-unsaturated monocarboxylic acid ester, a di(C.sub.1-4 alkyl)
alpha, beta-unsaturated dicarboxylic acid ester, a vinyl
monocarboxylic acid ester, an alkyl vinyl ether, and a mixture
thereof. In still another embodiment of the invention the copolymer
of (B) further comprises an additional comonomer which is methyl
methacrylate. The additional comonomer is usually present in a
minor amount relative to the other two comonomers that are used to
form the copolymer of (B). The additional comonomer can be present
at 0.3 mole or less per mole of either of the other two comonomers,
and in other instances can be present at 0.2 mole or less and at
0.1 mole or less per mole of either of the other two comonomers.
Examples of useful additional third comonomers include methyl
methacrylate, methyl acrylate, diethyl fumarate, dimethyl maleate,
vinyl acetate, vinyl propionate, and ethyl vinyl ether.
[0025] The above described esterified copolymer of (B) can be
prepared by a free radical polymerization of the two or three
comonomers to form a copolymer, an acid catalyzed esterification of
the copolymer with a mixture of alcohols which optionally can
include lower molecular weight C.sub.1-4 alcohols to drive the
esterification toward completion, usually neutralization of the
esterification acid catalyst with a base such as an alkali metal
hydroxide, and optionally reaction of remaining unesterified
portions of the copolymer with an amine that has only one amino
group that is a primary or a secondary amino group. During the
esterification, azeotropic distillation with a solvent such as
toluene is generally used to remove the water by-product and to
drive the esterification toward completion. Prior to a final
distillation and filtration of the crude esterified copolymer, an
oxidation inhibitor can be added at levels of 0.05 to 1% by weight
of the final esterified copolymer product. The oxidation inhibitor
can include hindered phenols and alkylated diarylamines. Also prior
to the final distillation and filtration of the crude esterified
copolymer, a diluent is typically added at a level of 5 to 50% by
weight of the final esterified copolymer product, and in other
instances at a level of 10 to 40% by wt., and 15 to 30% by wt. The
diluent can be a mineral oil, a solvent, or a mixture thereof. The
solvent can be an aromatic hydrocarbon, an aliphatic hydrocarbon,
an alcohol, or a mixture thereof. U.S. Pat. No. 5,157,088 and
European Patent Publication No. EP626442 provide a description of a
general procedure for preparing esterified copolymers from two or
three comonomers of this invention.
[0026] The fatty carboxylic acid ester composition (A) can be
present in the fuel composition of this invention from 1 to 99.99%
by weight. The ester composition (A) is usually present in the fuel
composition in a major amount from 10 to 99.99% by weight, and in
other embodiments from 30 to 99.99% by weight, 55 to 99.99% by
weight, and 80 to 99.99% by weight. The low temperature operability
composition (B) can be present in the fuel composition in a minor
amount from 100 to 10,000 ppm (parts per million) by weight, and in
other embodiments from 500 to 9,000 ppm by wt., 1000 to 8000 ppm by
wt., 1500 to 7000 ppm by wt., 2000 to 6000 ppm by wt., and 2000 to
5000 ppm by wt.
[0027] The above described fuel composition of the present
invention can further comprise (C) at least one additional fuel
additive. The at least one additional fuel additive included in the
fuel composition will generally depend on the application that the
fuel composition is to be used for. A fuel composition intended for
use in an internal combustion engine can further comprise at least
one additional fuel additive to include nitrogen-containing
detergents, amine-containing polyethers, metal-containing
detergents, antioxidants such as hindered phenols, rust inhibitors
such as alkenylsuccinic acids, corrosion inhibitors such as
alkylamines, combustion improvers such as nitroalkanes,
demulsifiers, antifoaming agents, valve seat recession additives,
metal deactivators, supplementary lubricity agents, bacteriostatic
agents, gum inhibitors, anti-icing agents, anti-static agents,
organometallic fuel-borne catalysts for improved combustion
performance, supplementary low temperature flow improvers, and
fluidizers such as mineral oils, polyolefins and polyethers. The
additional fuel additive or additives can be present in the fuel
composition depending on the function of each additive from 0.1 to
10,000 ppm by weight.
[0028] The fuel composition, of this invention can further comprise
(D) a normally liquid fuel. The normally liquid fuel can be a
hydrocarbon fuel, a nonhydrocarbon fuel, or a mixture thereof. The
hydrocarbon fuel can be a petroleum distillate to include a
gasoline as defined by ASTM specification D4814 or a diesel fuel as
defined by ASTM specification D975. The hydrocarbon fuel can be a
hydrocarbon prepared by a gas to liquid process to include the
Fischer-Tropsch Process, the Lurgi Process, the Oil/Gas Process,
and the SASOL Process. The nonhydrocarbon fuel can be an
oxygen-containing composition to include an alcohol, an ether, a
nitroalkane, a plant or animal oil or fat, or a mixture thereof.
The nonhydrocarbon fuel can be an oxygenated derivative of a
hydrocarbon prepared by a gas to liquid process to include those
listed above for hydrocarbon fuels such as the Fischer-Tropsch
Process. Useful nonhydrocarbon fuels include methanol, ethanol,
diethyl ether, methyl t-butyl ether, and nitromethane. Useful
mixtures of fuels include a mixture of hydrocarbon fuels such as a
mixture of a petroleum distillate and a gas to liquid process
hydrocarbon, a mixture of nonhydrocarbon fuels such as a mixture of
ethanol and methanol, and a mixture of hydrocarbon and
nonhydrocarbon fuels such as a mixture of gasoline and ethanol
and/or methanol, a mixture of a diesel fuel and ethanol, and a
mixture of a gas to liquid process hydrocarbon and an alcohol
and/or an ether and/or a nitroalkane. In an embodiment of the
invention the normally liquid fuel is an emulsion of water in a
hydrocarbon fuel, a nonhydrocarbon fuel, or a mixture thereof as
described hereinabove. This emulsion can be prepared by a
mechanical mixing, by including one or more emulsifiers and/or
surfactants in the emulsion, or by a combination of mechanical
mixing and inclusion of emulsifiers and/or surfactants. The
normally liquid fuel can comprise a hydrocarbon fuel that has a
reduced sulfur content such as a gasoline having a sulfur content
at or below 1,000 ppm by wt. or a diesel fuel having a sulfur
content at or below 500 ppm by wt. In an embodiment of the
invention the normally liquid fuel (D) is a diesel fuel. The
normally liquid fuel can be present in the fuel composition of the
invention up to 98% by weight, and in other embodiments can be
present in the fuel composition up to 69% by wt., up to 44% by wt.,
and up to 19% by wt.
[0029] The fuel composition of the present invention can be
prepared by simply combining the above described components (A),
(B), and optionally (C) and (D) at ambient temperature. In another
embodiment of the invention the fuel composition can be prepared by
combining components (A), (B), and optionally (C) and (D), and
mixing the combined components at an elevated temperature of 40 to
100.degree. C. until the composition is homogeneous.
[0030] A method of the present invention for improving the low
temperature operability of a fuel composition, as described above,
comprises admixing the above described ester composition (A) with a
low temperature improving amount of the above described composition
(B). The amount of the composition (B) to add can vary from 100 to
10,000 ppm by weight, and will normally increase as the amount of
(A) increases in the fuel composition. In an embodiment of the
invention the amount of composition (B) to improve the low
temperature operability of the fuel composition containing (A) is
an amount of (B) that lowers the cold filter plugging point (CFPP),
as measured by the ASTM D6371 standard test method for cold filter
plugging point of diesel and heating fuels, of the fuel composition
below the CFPP of an untreated sample of (A). In another embodiment
of the invention the amount of (3) to improve the low temperature
operability of the fuel composition is an amount that lowers the
CFPP of the fuel composition to -20.degree. C. or lower since most
esterified fatty acids from plant and animal fats and oils,
including transesterified naturally occurring triglycerides, have
CFPP values well above -20.degree. C.
[0031] The following examples are provided to demonstrate
advantages of the present invention, but they are not intended to
nor should they be used to limit the scope of the invention.
TABLE-US-00001 CFPP Evaluation of Biodiesel Fuel Compositions.sup.1
RME1.sup.3 RME2.sup.3 RME3.sup.3 RME4.sup.3 Example ACL.sup.2
.degree. C.(ppm) .degree. C.(ppm) .degree. C.(ppm) .degree. C.(ppm)
1 -- -14 -15.5 -13 -14 comparative 2 9.1 -14(6k) -- -16(4k) --
comparative 3 10.4 -13(6k) -15(6k) -24(3.5k) -12(6k) 4 11.3
-20(2.5k) -22(2.5k) -21(2.5k) -22(6k) 5 12.8 -18(4k) -- -13.5(6k)
-- comparative .sup.1The cold filter plugging points (CFPP) of
biodiesel fuel compositions in examples 1-5 were measured per the
ASTM D6371 standard test method. Example 1 provides CFPP values of
four untreated rapeseed methyl ester samples as a comparative
baseline. In examples 2-5 the CFPP values were measured for
biodiesel fuel compositions containing the rapeseed methyl ester
samples and varying levels of maleic anhydride-styrene copolymer
esterified with alcohol mixtures that varied in # average carbon
length with examples 2 and 5 being comparative since their average
carbon length is outside the present invention. Each of the
esterified copolymers contained 20% by weight of an aromatic
solvent. .sup.2ACL is average carbon length of the alcohol mixture
on a weight percent basis that was used to esterify the maleic
anhydride-styrene copolymer. .sup.3RME1 through RME4 are the
rapeseed methyl ester samples obtained from different suppliers and
used in examples 1-5. The CFPP values are given in degrees
centigrade and the values in parentheses are levels of esterified
copolymers including aromatic solvent used to treat the rapeseed
methyl esters in thousands of ppm by weight. For example, 6k
represents a 6000 ppm by weight treatment level.
[0032] Each of the documents referred to in this Detailed
Description of the Invention section is incorporated herein by
reference. All chemical treatments or contents throughout this
application regarding the present invention are understood to be as
actives unless indicated otherwise even though solvents or diluents
may be present.
* * * * *