U.S. patent application number 11/679566 was filed with the patent office on 2007-09-06 for gasoline fuel compositions having increased oxidative stability.
This patent application is currently assigned to NOVUS INTERNATIONAL INC.. Invention is credited to Ibrahim Abou-Nemeh.
Application Number | 20070204505 11/679566 |
Document ID | / |
Family ID | 38475656 |
Filed Date | 2007-09-06 |
United States Patent
Application |
20070204505 |
Kind Code |
A1 |
Abou-Nemeh; Ibrahim |
September 6, 2007 |
GASOLINE FUEL COMPOSITIONS HAVING INCREASED OXIDATIVE STABILITY
Abstract
The present invention relates to gasoline or a gasoline and
ethanol blend fuel compositions that have improved oxidation
stability. More specifically, the gasoline or a gasoline and
ethanol blend fuel compositions include at least one antioxidant
that increases the oxidative stability of the fuel. The gasoline or
a gasoline and ethanol blend fuel compositions may also include an
antioxidant mixture, or an antioxidant mixture in combination with
a polar and/or nonpolar solvent, that increases the oxidative
stability of the fuel.
Inventors: |
Abou-Nemeh; Ibrahim; (Lake
St. Louis, MO) |
Correspondence
Address: |
POLSINELLI SHALTON FLANIGAN SUELTHAUS PC
700 W. 47TH STREET
SUITE 1000
KANSAS CITY
MO
64112-1802
US
|
Assignee: |
NOVUS INTERNATIONAL INC.
530 Maryville Centre Drive
St. Louis
MO
63141
|
Family ID: |
38475656 |
Appl. No.: |
11/679566 |
Filed: |
February 27, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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60778537 |
Mar 2, 2006 |
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Current U.S.
Class: |
44/333 ;
44/451 |
Current CPC
Class: |
C10L 1/1832 20130101;
C10L 1/23 20130101; C10L 1/28 20130101; C10L 1/189 20130101; C10L
1/223 20130101; C10L 1/226 20130101; C10L 1/2641 20130101; C10L
1/19 20130101; C10L 1/1852 20130101; C10L 1/1857 20130101; C10L
1/183 20130101; C10L 1/1824 20130101; C10L 1/1616 20130101; C10L
1/1855 20130101; C10L 1/14 20130101; C10L 1/1905 20130101; C10L
1/191 20130101; C10L 1/232 20130101; C10L 1/2235 20130101 |
Class at
Publication: |
044/333 ;
044/451 |
International
Class: |
C10L 1/22 20060101
C10L001/22 |
Claims
1. A fuel composition, the composition comprising: (a) A gasoline;
(b) An ethanol; and (c) An antioxidant comprising Formula (I):
##STR5## wherein: R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are
independently selected from the group consisting of hydrogen and an
alkyl group having from 1 to about 6 carbons; R.sup.5 is an alkoxy
group having from 1 to about 12 carbons.
2. The fuel composition of claim 1, comprising at least one
additional antioxidant selected from the group consisting of
butylated hydroxyanisole; butylated hydroxytoluene; octyl gallate;
dodecyl gallate; 3,4,5-trihydroxybenzoic acid n-propyl ester;
1,2,3-trihydroxybenzene; methyl linoleate; methyl oleate; methyl
stearate; 2,2,6,6-tetramethylpiperidinooxy;
2,2,6,6-tetramethyl-4-hydroxypiperidine-1-oxyl;
dimethyl-p-phenylaminophenoxysilane; di-p-anisylazoxides;
p-hydroxydiphenylamine; ascorbyl palmitate; butylated
hydroxyanisole; butylated hydroxytoluene;
phenyl-alpha-naphthylamine; hydroquinone; 2-tert-butylhydroquinone;
3-tertiarybutyl-4-hydroxyanisole;
2,6-di-tert-butyl-4-hydroxymethylphenol;
2-6-di-tert-butyl-4-methylphenol; t-tert-butyl-4-methylphenol;
2-ter-butyl-4-methoxyphenol; polyphosphates; trihydroxy
butyrophenone; and anoxomer.
3. The fuel composition of claim 1, comprising at least one
additional antioxidant selected from the group consisting of
2-tert-butylhydroquinone; 3,4,5-trihydroxybenzoic acid n-propyl
ester; mono tertiary butyl hydroquinone; di-tert-butyl
hydroquinone; 1,2,3-trihydroxybenzene;
2-tert-butyl-4-hydroxyanisole; t-tert-butyl-4-methylphenol; and
2,6-Di-tert-Butyl-1-Hydroxy-4-Methylbenzene.
4. The fuel composition of claim 1, wherein the antioxidant is
6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline.
5. The fuel composition of claim 4, wherein the fuel contains from
about 20 ppm to about 1500 ppm
6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline.
6. The fuel composition of claim 4, wherein the fuel contains from
about 50 ppm to about 500 ppm
6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline.
7. The fuel composition of claim 4, further comprising
2-tert-butylhydroquinone.
8. The fuel composition of claim 4, further comprising
2-tert-butyl-4-hydroxyanisole; and
2,6-Di-tert-Butyl-1-Hydroxy-4-Methylbenzene
9. The fuel composition of claim 4, further comprising
2-tert-butylhydroquinone, and a paraffin oil.
10. The fuel composition of claim 4, further comprising
2-tert-butyl-4-hydroxyanisole,
2,6-Di-tert-Butyl-1-Hydroxy-4-Methylbenzene, and a paraffin
oil.
11. The fuel composition of claim 1, wherein the fuel comprises
from about 60% to about 99% by weight gasoline and from about 1% to
about 40% by weight ethanol.
12. The fuel composition of claim 1, wherein the fuel comprises
from about 80% to about 90% by weight gasoline and from about 10%
to about 20% by weight ethanol.
13. The fuel composition of claim 1, wherein the fuel has
substantially improved oxidative stability.
14. The fuel composition of claim 1, wherein the fuel has an
induction time of greater about than 1400 minutes.
15. The fuel composition of claim 1, wherein the fuel has
substantially reduced gumming.
16. The fuel composition of claim 1, further comprising an additive
selected from the group comprising of octane improvers, drive
ability additives, metal deactivators, corrosion inhibitors,
thermal stabilizers, detergents, and demulsifiers.
17. The fuel composition of claim 1, further comprising a solvent
selected from the group consisting of a polar solvent and a non
polar solvent.
18. A fuel composition, the composition comprising: (a) A gasoline
in an amount ranging from about 60% to about 99% by weight of the
composition; (b) An ethanol in an amount ranging from about 1% to
about 40% by weight of the composition; and (c)
6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline in an amount ranging
from about 20 to about 1500 ppm.
19. The fuel composition of claim 18, wherein the composition
comprises about 80% to about 90% by weight gasoline; from about 10%
to about 20% by weight ethanol; and from about 50 ppm to about 500
ppm 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline.
20. The fuel composition of claim 18, comprising at least one
additional antioxidant selected from the group consisting of
butylated hydroxyanisole; butylated hydroxytoluene; octyl gallate;
dodecyl gallate; 3,4,5-trihydroxybenzoic acid n-propyl ester;
1,2,3-trihydroxybenzene; methyl linoleate; methyl oleate; methyl
stearate; 2,2,6,6-tetramethylpiperidinooxy;
2,2,6,6-tetramethyl-4-hydroxypiperidine-1-oxyl;
dimethyl-p-phenylaminophenoxysilane; di-p-anisylazoxides;
p-hydroxydiphenylamine; ascorbyl palmitate; butylated
hydroxyanisole; butylated hydroxytoluene;
phenyl-alpha-naphthylamine; hydroquinone; 2-tert-butylhydroquinone;
3-tertiarybutyl-4-hydroxyanisole;
2,6-di-tert-butyl-4-hydroxymethylphenol;
2-6-di-tert-butyl-4-methylphenol; t-tert-butyl-4-methylphenol;
2-ter-butyl-4-methoxyphenol; polyphosphates; trihydroxy
butyrophenone; and anoxomer.
21. The fuel composition of claim 18, comprising at least one
additional antioxidant selected from the group consisting of
2-tert-butylhydroquinone; 3,4,5-trihydroxybenzoic acid n-propyl
ester; mono tertiary butyl hydroquinone; di-tert-butyl
hydroquinone; 1,2,3-trihydroxybenzene,
2-tert-butyl-4-hydroxyanisole; t-tert-butyl-4-methylphenol; and
2,6-Di-tert-Butyl-1-Hydroxy-4-Methylbenzene.
22. The fuel composition of claim 18, further comprising
2-tert-butylhydroquinone.
23. The fuel composition of claim 18, further comprising
2-tert-butyl-4-hydroxyanisole; and
2,6-Di-tert-Butyl-1-Hydroxy-4-Methylbenzene
24. The fuel composition of claim 18, further comprising
2-tert-butylhydroquinone, and a paraffin oil.
25. The fuel composition of claim 18, further comprising
2-tert-butyl-4-hydroxyanisole,
2,6-Di-tert-Butyl-1-Hydroxy-4-Methylbenzene, and a paraffin
oil.
26. The fuel composition of claim 18, wherein the fuel has an
improved oxidative stability.
27. The fuel composition of claim 18, wherein the fuel has an
induction time of greater than 1400 minutes.
28. The fuel composition of claim 18, wherein the fuel has
substantially reduced gumming.
29. The fuel composition of claim 18, wherein the ethanol is
produced from a source selected from the group consisting of corn,
plant-derived cellulose material, sugarcane, sugar beet, grain
sorghum, sugar cane, sugar beet, wheat, barley, potatoes, and
biomass.
30. The fuel composition of claim 18, further comprising an
additive selected from the group comprising of octane improvers,
drive ability additives, metal deactivators, corrosion inhibitors,
thermal stabilizers, detergents, and demulsifiers.
31. The fuel composition of claim 18, further a solvent selected
from the group consisting of a polar solvent and a non polar
solvent.
32. A method for increasing the oxidative stability of a fuel
composition, the fuel composition comprising gasoline and ethanol,
the method comprising contacting the fuel composition with an
antioxidant comprising Formula (I): ##STR6## wherein: R.sup.1,
R.sup.2, R.sup.3 and R.sup.4 are independently selected from the
group consisting of hydrogen and an alkyl group having from 1 to
about 6 carbons; R.sup.5 is an alkoxy group having from 1 to about
12 carbons.
33. The method of claim 32, comprising at least one additional
antioxidant selected from the group consisting of butylated
hydroxyanisole; butylated hydroxytoluene; octyl gallate; dodecyl
gallate; 3,4,5-trihydroxybenzoic acid n-propyl ester;
1,2,3-trihydroxybenzene; methyl linoleate; methyl oleate; methyl
stearate; 2,2,6,6-tetramethylpiperidinooxy;
2,2,6,6-tetramethyl-4-hydroxypiperidine-1-oxyl;
dimethyl-p-phenylaminophenoxysilane; di-p-anisylazoxides;
p-hydroxydiphenylamine; ascorbyl palmitate; butylated
hydroxyanisole; butylated hydroxytoluene;
phenyl-alpha-naphthylamine; hydroquinone; 2-tert-butylhydroquinone;
3-tertiarybutyl-4-hydroxyanisole;
2,6-di-tert-butyl-4-hydroxymethylphenol;
2-6-di-tert-butyl-4-methylphenol; t-tert-butyl-4-methylphenol;
2-ter-butyl-4-methoxyphenol; polyphosphates; trihydroxy
butyrophenone; and anoxomer.
34. The method of claim 32, comprising at least one additional
antioxidant selected from the group consisting of
2-tert-butylhydroquinone; 3,4,5-trihydroxybenzoic acid n-propyl
ester; mono tertiary butyl hydroquinone; di-tert-butyl
hydroquinone; 1,2,3-trihydroxybenzene,
2-tert-butyl-4-hydroxyanisole, t-tert-butyl-4-methylphenol; and
2,6-Di-tert-Butyl-1-Hydroxy-4-Methylbenzene.
35. The method of claim 32, wherein the antioxidant is
6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline.
36. The method of claim 35, wherein the fuel contains from about 20
ppm to about 1500 ppm
6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline.
37. The method of claim 35, wherein the fuel contains from about 50
ppm to about 500 ppm
6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline.
38. The method of claim 35, further comprising
2-tert-butylhydroquinone.
39. The method of claim 35, further comprising
2-tert-butyl-4-hydroxyanisole; and
2,6-Di-tert-Butyl-1-Hydroxy-4-Methylbenzene
40. The method of claim 35, further comprising
2-tert-butylhydroquinone, and a paraffin oil.
41. The method of claim 35, further comprising
2-tert-butyl-4-hydroxyanisole,
2,6-Di-tert-Butyl-1-Hydroxy-4-Methylbenzene, and a paraffin
oil.
42. The method of claim 32, wherein the fuel comprises from about
60% to about 99% by weight gasoline and from about 1% to about 40%
by weight ethanol.
43. The method of claim 32, wherein the fuel comprises from about
80% to about 90% by weight gasoline and from about 10% to about 20%
by weight ethanol.
44. The method of claim 32, wherein the fuel has an induction time
of greater about than 1400 minutes.
45. The method of claim 32, wherein the ethanol is produced from a
source selected from the group consisting of corn, plant-derived
cellulose material, sugarcane, sugar beet, grain sorghum, sugar
cane, sugar beet, wheat, barley, potatoes, and biomass.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority from Provisional
Application Ser. No. 60/778,537 filed on Mar. 2, 2006, which is
hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to gasoline or a gasoline and
ethanol blend fuel compositions that have improved oxidation
stability. More specifically, the gasoline and ethanol blend fuel
compositions include at least one antioxidant that increases the
oxidative stability of the fuel.
BACKGROUND OF THE INVENTION
[0003] Gasoline and gasoline and ethanol blends compositions are
typically used as fuels for internal combustion engines. Various
processes including a catalytic cracking process from crude oil and
a catalytic reforming process from low-octane naphthas may be
utilized to produce gasoline. Gasoline fuels, despite their method
of production, easily oxidize in the presence of oxygen, UV light,
and heat. The products formed from this oxidation give rise to
sediment or gum formation within the fuel and may cause corrosion
and plugging of internal combustion engines.
[0004] As such, there is a need for a gasoline or gasoline and
ethanol blend composition having improved oxidation stability that
reduces or eliminates sedimentation and gum formation within the
fuel and concomitantly, reduces or eliminates corrosion or plugging
of internal combustion engines.
SUMMARY OF THE INVENTION
[0005] One aspect of the present invention provides a fuel
composition. The fuel composition comprises gasoline; ethanol; and
an antioxidant comprising Formula (I): ##STR1##
[0006] wherein: [0007] R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are
independently selected from the group consisting of hydrogen and an
alkyl group having from 1 to about 6 carbons; [0008] R.sup.5 is an
alkoxy group having from 1 to about 12 carbons.
[0009] Yet another aspect of the invention encompasses a fuel
composition comprising gasoline in an amount ranging from about 60%
to about 99% by weight of the composition; ethanol in an amount
ranging from about 1% to about 40% by weight of the composition;
and 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline in an amount
ranging from about 20 to about 1500 ppm.
[0010] A further aspect of the invention provides a method for
increasing the oxidative stability of a fuel composition comprising
gasoline and ethanol. The method comprises contacting the fuel
composition with an antioxidant comprising Formula (I):
##STR2##
[0011] wherein: [0012] R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are
independently selected from the group consisting of hydrogen and an
alkyl group having from 1 to about 6 carbons; [0013] R.sup.5 is an
alkoxy group having from 1 to about 12 carbons.
[0014] Other aspects and iterations of the invention will be in
part apparent and in part pointed out hereinafter.
FIGURES
[0015] FIG. 1 is a graph depicting the effect of ethanol on the
induction period of gasoline compositions. Plotted is the induction
time versus the amount of ethanol in each gasoline formulation.
[0016] FIG. 2 is a graph depicting effect of ethoxyquin (labeled as
ETQ) on the induction period of ethanol free gasoline.
[0017] FIG. 3 is a graph depicting the effect of ethoxyquin (ETQ)
and ethanol (ETOH) on the induction period. Plotted is the
induction period in minutes versus level of ethoxyquin in ppm.
DETAILED DESCRIPTION OF THE INVENTION
[0018] The present invention provides gasoline fuel compositions
that have improved oxidative stability. Typically, the gasoline
fuel compositions comprise gasoline, at least one antioxidant that
increases gasoline stability, and optionally, ethanol. In addition
to improved oxidative stability, the gasoline fuel compositions
also may have longer induction times, lower amounts of insolubes,
and lower peroxide values. Advantageously, the gasoline fuel
compositions may also have lower NO.sub.x and CO.sub.2
emissions.
I. Gasoline
[0019] The fuel composition of the invention includes gasoline.
Gasoline suitable for use in the invention is typically a
petroleum-derived liquid mixture consisting mostly of hydrocarbons
used as fuel in internal combustion engines. The hydrocarbons
forming the gasoline generally consist of between 5 to about 12
carbon atoms per molecule. A typical gasoline may include a mixture
of paraffins, naphthenes, aromatics, and olefins. The ratios of
these components forming gasoline suitable for use in the invention
can and will vary depending on a variety of factors, such as, the
oil refining process, the crude oil used, and the grade of
gasoline.
[0020] Exemplary gasoline formulations will generally have a
relatively high octane rating. The gasoline composition, for
example, may have an octane rating of greater than about 85%, about
86%, about 87%, about 88%, about 89%, about 90%, about 91%, about
92%, about 93%, about 94%, about 95%, about 96%, about 97%, about
98%, about 99%, or about 100%. Octane rating may be measured by any
method generally known in the art, such as by the Research Octane
Number (i.e., RON). Generally speaking, in this method octane
rating of gasoline is typically measured relative to a mixture of
isooctane (i.e., 2,2,4-trimethylpentane) and n-heptane by running
the fuel samples through a specific test engine with a variable
compression ratio under controlled conditions. By way of example,
an 87-octane gasoline typically has the same octane rating as a
mixture of 87% (v/v) isooctane and 13% (v/v) n-heptane.
[0021] A variety of methods known in the art may be used to make
the gasoline of the present invention. The gasoline may be produced
through a catalytic cracking process from crude oil. As used
herein, a catalytic cracking process is defined as a refining
process by which certain crude cuts are broken down or "cracked"
into simpler hydrocarbon compounds at the molecular level by means
of extreme heat, pressure, and exposure to a chemical catalyst.
Alternatively, gasoline may be produced by a catalytic reforming
process. A variety of catalytic reforming processes are suitable to
produce gasoline, including but not limited to, platforming,
powerforming, ultraforming, and Thermofor catalytic reforming.
Generally, in a catalytic reforming process low-octane naphthas are
subjected to a high temperatures and relatively mild hydrogen
partial pressures in the presence of multinuclear catalysts, such
as platinum, or rhenium, or on a carrier such as zeolites. During
the process, the naphtha feedstock, mainly consisting of paraffins,
undergoes numerous reactions including hydrogenation, alkylation,
polymerization, cracking, cyclization, isomerization, among others.
The process produces light paraffinic gases (LPG), hydrogen, and
the aromatic and naphthenic compounds that make up the backbone of
high-octane gasoline, such as benzene, toluene, cyclopentane,
cyclohexane, and ethyl-benzene, among others. Alternatively, the
gasoline may be purchased from a commercially available source.
II. Ethanol
[0022] The present invention also contemplates fuels that are
blends of gasoline and ethanol. Generally speaking, ethanol, also
known as ethyl alcohol or grain alcohol, is used as fuel or as an
octane-boosting, pollution-reducing additive to gasoline.
[0023] The ethanol may be present in a gasoline ethanol mixture in
an amount ranging from about 0% to about 5%, from about 5% to about
10%, from about 10% to about 15%, from about 15% to about 20%, from
about 20% to about 25%, from about 25% to about 30%, from about 30%
to about 35%, from about 35% to about 40%, from about 40% to about
45%, from about 45% to about 50%, from about 50% to about 55%, from
about 55% to about 60%, from about 60% to about 65%, from about 65%
to about 70%, from about 70% to about 75%, from about 75% to about
80%, from about 80% to about 85%, from about 85% to about 90%, from
about 90% to about 95%, or greater than about 95% by weight of the
composition. Exemplary compositions may include ethanol in an
amount ranging from about 5% to about 10%, from about 10% to about
15%, from about 15% to about 20%, from about 20% to about 25%, from
about 25% to about 30%, from about 30% to about 35%, or less than
40% by weight of the composition.
[0024] Ethanol may be produced using a variety of feedstocks. For
example, ethanol may be produced from biomass or crops. In one
embodiment, the ethanol is produced from a crop. Suitable crops for
ethanol production include corn, milo, sorghum, wheat, barley,
potatoes, sugarcane, hemp, kenaf, sugar beets, barley, cassaya,
sunflower, seaweed, and eucalyptus. It is, however, envisioned that
other crops may also be used without departing from the scope of
the invention. In another embodiment, the ethanol is produced from
biomass. Suitable biomass for ethanol production may include farm
wastes, agricultural forestry residues, industrial waste, municipal
waste, trees, grasses, sugarcane residues, rice hulls, paper mill
wastes, molasses, and other organic or cellulose materials. In yet
another embodiment, the ethanol is produced from a plant-derived,
cellulose material. Suitable plant-derived, cellulose materials
include switchgrass, corncobs, wheat straw, corn stover, and
sawdust. As will be appreciated by the skilled artisan, ethanol may
also be produced from a combination of different sources. In an
exemplary embodiment, the ethanol is produced from a source
selected from the group consisting of corn, grain sorghum, wheat,
barley, potatoes, sugar cane, plant-derived cellulose material, and
biomass. In a further exemplary embodiment, the ethanol is produced
from corn. In another exemplary embodiment, the ethanol is produced
from a plant-derived cellulose material.
[0025] Several methods generally known in the art may be used to
produce ethanol without departing from the scope of the invention.
In general, ethanol may be produced by chemical synthesis or
biological fermentation. Chemical synthesis involves the hydrolysis
of ethylene obtained from coal gasification or other mineral
livestock. This method is generally used for low volume
applications that need unusually high purity, anhydrous ethanol and
fills a niche market found in the chemical industry. Fermentation
for the production of ethanol utilizes microorganisms, most
commonly yeast, for the conversion of sugars to alcohols. This
process occurs in the absence of oxygen forcing the microorganisms
to utilize an anaerobic metabolic pathway. This pathway converts
sugars into ethanol, carbon dioxide, chemical energy, and kinetic
(heat) energy. Typically, a dry mill process produces fuel grade
ethanol from grains. Such a process typically includes milling,
liquefaction, saccharification, fermentation, distillation,
dehydration, and denaturing. Another embodiment that may be used to
produce ethanol includes contacting a biomass with genetically
engineered Escherichia Coli strains, as disclosed in U.S. Pat. No.
5,000,000, herein incorporated by reference. Alternatively, the
ethanol may be purchased from a commercially available source.
II. Antioxidants
[0026] The gasoline composition of the invention also includes one
or more antioxidants. Suitable antioxidants for use in the present
invention substantially inhibit the oxidation process and thus,
enhance the fuel composition's oxidative stability. Methods for
measuring oxidative stability of a gasoline composition are
described in more detail below, and in particular, in the
Examples.
(a) Individual Antioxidants
[0027] Those skilled in the art will appreciate that several
suitable antioxidants may be used depending on the type of fuel to
be stabilized. In one embodiment, the antioxidant may be selected
from the group comprising of hindered amines, such as diphenyl
amines; butylated hydroxyanisole; butylated hydroxytoluene;
gallates such as octyl gallate, dodecyl gallate, and
3,4,5-trihydroxybenzoic acid n-propyl ester (propyl gallate);
1,2,3-trihydroxybenzene (pyrogallol); fatty acid esters including,
but not limited to, methyl esters such as methyl linoleate, methyl
oleate, methyl stearate, 2,2,6,6-tetramethylpiperidinooxy, also
referred to as tanan;
2,2,6,6-tetramethyl-4-hydroxypiperidine-1-oxyl, also referred to as
tanol; dimethyl-p-phenylaminophenoxysilane; di-p-anisylazoxides;
p-hydroxydiphenylamine, and carbonates, phthalates, and adipates
thereof; and diludin, a 1,4-dihydropyridine derivative.
[0028] In another embodiment, the antioxidant may be selected from
the group comprising oil-soluble antioxidants, including, but not
limited to ascorbyl palmitate, butylated hydroxyanisole, butylated
hydroxytoluene, phenyl-alpha-naphthylamine, and hydroquinone.
[0029] In a further embodiment, the antioxidant may be a synthetic
antioxidants selected from the phenolic acids and derivatives;
2-tert-butylhydroquinone (TBHQ); mixtures of TBHQ and
2-tertiarybutyl-4-hydroxyanisole; 3-tertiarybutyl-4-hydroxyanisole;
2,6-di-tert-butyl-4-hydroxymethylphenol;
2-6-di-tert-butyl-4-methylphenol (BHT) and
t-tert-butyl-4-methylphenol (t-BHT); 2-ter-butyl-4-methoxyphenol
(BHA); mono tertiary butyl hydroquinone, di-tert-butyl
hydroquinone, polyphosphates; trihydroxy butyrophenone; anoxomer;
and combinations thereof. Other suitable synthetic antioxidants
include the antioxidants marketed under the names VANLUBE, IONOL,
and BAYNOX.
[0030] In another embodiment, the antioxidant may be a quinoline or
a substituted quinoline. In an exemplary embodiment, the quinoline
is a substituted 1,2-dihydroquinoline compound. Substituted
1,2-dihydroquinoline compounds suitable for use in the invention
may correspond to formula (I): ##STR3##
[0031] wherein: [0032] R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are
independently selected from the group consisting of hydrogen and an
alkyl group having from 1 to about 6 carbons; [0033] R.sup.5 is an
alkoxy group having from 1 to about 12 carbons.
[0034] In another embodiment, the substituted 1,2-dihydroquinoline
will have formula (I) wherein: [0035] R.sup.1, R.sup.2, R.sup.3 and
R.sup.4 are independently selected from the group consisting of
hydrogen and an alkyl group having from 1 to about 4 carbons; and
[0036] R.sup.5 is an alkoxy group having from 1 to about 4
carbons.
[0037] An exemplary substituted 1,2-dihydroquinoline is
6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline having the formula:
##STR4## 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, commonly
known as ethoxyquin, is sold under the trademark SANTOQUIN.RTM. (by
Novus International Inc. of Saint Louis Mo.). The present invention
also encompasses salts of ethoxyquin and other compounds having
formula (I). Ethoxyquin and other compounds having formula (I) may
be purchased commercially from Novus International, Inc. or made in
accordance with methods generally known in the art, for example, as
detailed in U.S. Pat. No. 4,772,710, which is hereby incorporated
by reference in its entirety. (b) Antioxidant Formulations
[0038] The antioxidant may be a blend of any of the antioxidants
detailed in II(a). For example, the antioxidant may include, two,
three, four, five or more of any of the aforementioned
antioxidants. In an exemplary embodiment, the antioxidant blend
will include a compound having formula (I). Non-limiting examples
of suitable antioxidant blends are detailed in Table A.
TABLE-US-00001 TABLE A First Antioxidant Second Antioxidant or
Antioxidant Mixture 6-ethoxy-1,2-dihydro-2,2,4-
2-tert-butylhydroquinone trimethylquinoline
6-ethoxy-1,2-dihydro-2,2,4- 3,4,5-trihydroxybenzoic acid n-propyl
ester trimethylquinoline 6-ethoxy-1,2-dihydro-2,2,4-
1,2,3-trihydroxybenzene trimethylquinoline
6-ethoxy-1,2-dihydro-2,2,4- 2-tert-butyl-4-hydroxyanisole
trimethylquinoline 6-ethoxy-1,2-dihydro-2,2,4-
t-tert-butyl-4-methylphenol trimethylquinoline
6-ethoxy-1,2-dihydro-2,2,4-
2,6-Di-tert-Butyl-1-Hydroxy-4-Methylbenzene trimethylquinoline
6-ethoxy-1,2-dihydro-2,2,4- dodecyl gallate trimethylquinoline
6-ethoxy-1,2-dihydro-2,2,4- octyl gallate trimethylquinoline
6-ethoxy-1,2-dihydro-2,2,4- 2-tert-butylhydroquinone and 3,4,5-
trimethylquinoline trihydroxybenzoic acid n-propyl ester
6-ethoxy-1,2-dihydro-2,2,4- 2-tert-butylhydroquinone and 1,2,3-
trimethylquinoline trihydroxybenzene 6-ethoxy-1,2-dihydro-2,2,4-
1,2,3-trihydroxybenzene and 2-tert-butyl-4- trimethylquinoline
hydroxyanisole 6-ethoxy-1,2-dihydro-2,2,4- 1,2,3-trihydroxybenzene
and t-tert-butyl-4- trimethylquinoline methylphenol
6-ethoxy-1,2-dihydro-2,2,4- 1,2,3-trihydroxybenzene and
2,6-Di-tert-Butyl-1- trimethylquinoline Hydroxy-4-Methylbenzene
6-ethoxy-1,2-dihydro-2,2,4- 1,2,3-trihydroxybenzene and dodecyl
gallate trimethylquinoline 6-ethoxy-1,2-dihydro-2,2,4-
1,2,3-trihydroxybenzene and octyl gallate trimethylquinoline
6-ethoxy-1,2-dihydro-2,2,4- 3,4,5-trihydroxybenzoic acid n-propyl
ester and trimethylquinoline 1,2,3-trihydroxybenzene
6-ethoxy-1,2-dihydro-2,2,4- 3,4,5-trihydroxybenzoic acid n-propyl
ester and trimethylquinoline 2-tert-butyl-4-hydroxyanisole
6-ethoxy-1,2-dihydro-2,2,4- 3,4,5-trihydroxybenzoic acid n-propyl
ester and trimethylquinoline t-tert-butyl-4-methylphenol
6-ethoxy-1,2-dihydro-2,2,4- 3,4,5-trihydroxybenzoic acid n-propyl
ester and trimethylquinoline
2,6-Di-tert-Butyl-1-Hydroxy-4-Methylbenzene
6-ethoxy-1,2-dihydro-2,2,4- 3,4,5-trihydroxybenzoic acid n-propyl
ester and trimethylquinoline dodecyl gallate
6-ethoxy-1,2-dihydro-2,2,4- 3,4,5-trihydroxybenzoic acid n-propyl
ester and trimethylquinoline octyl gallate
6-ethoxy-1,2-dihydro-2,2,4- 1,2,3-trihydroxybenzene and
2-tert-butyl-4- trimethylquinoline hydroxyanisole
6-ethoxy-1,2-dihydro-2,2,4- 1,2,3-trihydroxybenzene and
t-tert-butyl-4- trimethylquinoline methylphenol
6-ethoxy-1,2-dihydro-2,2,4- 1,2,3-trihydroxybenzene and
2,6-Di-tert-Butyl-1-Hydroxy- trimethylquinoline 4-Methylbenzene
6-ethoxy-1,2-dihydro-2,2,4- 1,2,3-trihydroxybenzene and dodecyl
gallate trimethylquinoline 6-ethoxy-1,2-dihydro-2,2,4-
1,2,3-trihydroxybenzene and octyl gallate trimethylquinoline
6-ethoxy-1,2-dihydro-2,2,4- 2-tert-butyl-4-hydroxyanisole and
2,6-Di-tert- trimethylquinoline Butyl-1-Hydroxy-4-Methylbenzene
6-ethoxy-1,2-dihydro-2,2,4- 2-tert-butyl-4-hydroxyanisole and
dodecyl trimethylquinoline gallate 6-ethoxy-1,2-dihydro-2,2,4-
2-tert-butyl-4-hydroxyanisole and t-tert-butyl-4-
trimethylquinoline methylphenol 6-ethoxy-1,2-dihydro-2,2,4-
2-tert-butyl-4-hydroxyanisole and octyl gallate trimethylquinoline
6-ethoxy-1,2-dihydro-2,2,4- t-tert-butyl-4-methylphenol and
2,6-Di-tert-Butyl- trimethylquinoline 1-Hydroxy-4-Methylbenzene
6-ethoxy-1,2-dihydro-2,2,4- t-tert-butyl-4-methylphenol and dodecyl
gallate trimethylquinoline 6-ethoxy-1,2-dihydro-2,2,4-
t-tert-butyl-4-methylphenol and octyl gallate trimethylquinoline
6-ethoxy-1,2-dihydro-2,2,4-
2,6-Di-tert-Butyl-1-Hydroxy-4-Methylbenzene trimethylquinoline and
dodecyl gallate 6-ethoxy-1,2-dihydro-2,2,4-
2,6-Di-tert-Butyl-1-Hydroxy-4-Methylbenzene trimethylquinoline and
octyl gallate 6-ethoxy-1,2-dihydro-2,2,4- dodecyl gallate and octyl
gallate trimethylquinoline 6-ethoxy-1,2-dihydro-2,2,4-
2-tert-butyl-4-hydroxyanisole and 2,6-Di-tert-Butyl-
trimethylquinoline 1-Hydroxy-4-Methylbenzene
6-ethoxy-1,2-dihydro-2,2,4- 2-tert-butyl-4-hydroxyanisole and
2,6-Di-tert- trimethylquinoline Butyl-1-Hydroxy-4-Methylbenzene and
2-tert- butylhydroquinone 6-ethoxy-1,2-dihydro-2,2,4-
2-tert-butylhydroquinone and paraffin oil trimethylquinoline
6-ethoxy-1,2-dihydro-2,2,4- 2-tert-butyl-4-hydroxyanisole and
2,6-Di-tert- trimethylquinoline Butyl-1-Hydroxy-4-Methylbenzene and
paraffin oil 6-ethoxy-1,2-dihydro-2,2,4- 2-tert-butylhydroquinone,
1,2-Propanediol, and paraffin trimethylquinoline oil
(c) Solvents
[0039] The antioxidant composition may further comprise a polar
solvent or a non-polar solvent. Generally speaking, a polar solvent
may be utilized to solubilize any of the antioxidants that are
water-soluble and the non-polar solvent may be utilized to
solubilize hydrophobic antioxidants. Suitable examples of polar
solvents include, but are not limited to, alcohols such as
methanol, glycerol, isopropyl alcohol, ethyl alcohol, propylene
glycol, erythritol, xylitol, sorbitol, maltitol, mannitol, water,
or combinations thereof. In one embodiment, the polar solvent is
glycerol. In another embodiment, the polar solvent is propylene
glycol. Other suitable solvents include hexane, xylene, octane, and
paraffins. The concentration of the solvent will vary depending
upon the combination of antioxidants in the composition. In
general, the percent by volume of the solvent may range from about
5% to about 50%. The percent by volume of glycerol may be about 5%,
10%, 15%, 20%, or 25%. The percent by volume of propylene glycol
may be about 5%, 10%, 15%, 20%, or 25%.
III. Fuel Compositions
[0040] The invention provides several suitable combinations of
gasoline, ethanol, and antioxidants. In one alternative, the fuel
composition may comprise gasoline and one antioxidant. In another
alternative, the fuel composition may comprise gasoline, ethanol,
and one antioxidant. In yet a further alternative, the fuel
composition may comprise gasoline and at least two antioxidants. In
this embodiment, the fuel composition may be gasoline in
combination with any of the antioxidants described in Part II other
than 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline. Suitable
combinations of each type of fuel composition are detailed
below.
(a) Fuel Composition with Gasoline and One Antioxidant
[0041] Examples of exemplary fuel compositions having gasoline and
one antioxidant are presented in Table 1 below. Alternatively, each
fuel composition detailed in Table 1 may also include
6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline. TABLE-US-00002 TABLE
1 Fuel Antioxidants Gasoline 2-tert-butylhydroquinone Gasoline
3,4,5-trihydroxybenzoic acid n-propyl ester Gasoline
1,2,3-trihydroxybenzene Gasoline 2-tert-butyl-4-hydroxyanisole
Gasoline t-tert-butyl-4-methylphenol Gasoline
2,6-Di-tert-Butyl-1-Hydroxy-4-Methylbenzene Gasoline dodecyl
gallate Gasoline octyl gallate
(b) Fuel Composition with Gasoline, Ethanol and One Antioxidant
[0042] In another embodiment, the fuel composition of the invention
comprises a blend of gasoline, ethanol, and one antioxidant that
increases the oxidative stability of the fuel composition. In this
embodiment, the fuel composition may be any of the ethanols
described in Part I in combination with a gasoline and any of the
antioxidants described in Part II. Generally speaking, the fuel
composition may comprise from about 15% to about 95% by weight
gasoline and from about 5% to about 85% by weight ethanol. In
another embodiment, the fuel composition may comprise from about
80% to about 95% by weight gasoline and from about 5% to about 20%
by weight ethanol. In an alternative embodiment, the fuel
composition may comprise from about 90% to about 95% by weight
gasoline and from about 5% to about 10% by weight ethanol. Examples
of exemplary fuel compositions are presented in Table 2 below.
Alternatively, each fuel composition detailed in Table 2 may also
include 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline.
TABLE-US-00003 TABLE 2 Ethanol Fuel Fuel Raw Material Antioxidants
Gasoline Corn 2-tert-butylhydroquinone Gasoline Corn
3,4,5-trihydroxybenzoic acid n-propyl ester Gasoline Corn
1,2,3-trihydroxybenzene Gasoline Corn 2-tert-butyl-4-hydroxyanisole
Gasoline Corn t-tert-butyl-4-methylphenol Gasoline Corn
2,6-Di-tert-Butyl-1-Hydroxy-4- Methylbenzene Gasoline Corn dodecyl
gallate Gasoline Corn octyl gallate Gasoline Plant-derived
2-tert-butylhydroquinone cellulose material Gasoline Plant-derived
3,4,5-trihydroxybenzoic acid n-propyl ester cellulose material
Gasoline Plant-derived 1,2,3-trihydroxybenzene cellulose material
Gasoline Plant-derived 2-tert-butyl-4-hydroxyanisole cellulose
material Gasoline Plant-derived t-tert-butyl-4-methylphenol
cellulose material Gasoline Plant-derived
2,6-Di-tert-Butyl-1-Hydroxy-4- cellulose Methylbenzene material
Gasoline Plant-derived dodecyl gallate cellulose material Gasoline
Plant-derived octyl gallate cellulose material Gasoline Sugarcane
2-tert-butylhydroquinone Gasoline Sugarcane 3,4,5-trihydroxybenzoic
acid n-propyl ester Gasoline Sugarcane 1,2,3-trihydroxybenzene
Gasoline Sugarcane 2-tert-butyl-4-hydroxyanisole Gasoline Sugarcane
t-tert-butyl-4-methylphenol Gasoline Sugarcane
2,6-Di-tert-Butyl-1-Hydroxy-4- Methylbenzene Gasoline Sugarcane
dodecyl gallate Gasoline Sugarcane octyl gallate Gasoline Grain
sorghum 2-tert-butylhydroquinone Gasoline Grain sorghum
3,4,5-trihydroxybenzoic acid n-propyl ester Gasoline Grain sorghum
1,2,3-trihydroxybenzene Gasoline Grain sorghum
2-tert-butyl-4-hydroxyanisole Gasoline Grain sorghum
t-tert-butyl-4-methylphenol Gasoline Grain sorghum
2,6-Di-tert-Butyl-1-Hydroxy-4- Methylbenzene Gasoline Grain sorghum
dodecyl gallate Gasoline Grain sorghum octyl gallate Gasoline Wheat
2-tert-butylhydroquinone Gasoline Wheat 3,4,5-trihydroxybenzoic
acid n-propyl ester Gasoline Wheat 1,2,3-trihydroxybenzene Gasoline
Wheat 2-tert-butyl-4-hydroxyanisole Gasoline Wheat
t-tert-butyl-4-methylphenol Gasoline Wheat
2,6-Di-tert-Butyl-1-Hydroxy-4- Methylbenzene Gasoline Wheat dodecyl
gallate Gasoline Wheat octyl gallate Gasoline Barley
2-tert-butylhydroquinone Gasoline Barley 3,4,5-trihydroxybenzoic
acid n-propyl ester Gasoline Barley 1,2,3-trihydroxybenzene
Gasoline Barley 2-tert-butyl-4-hydroxyanisole Gasoline Barley
t-tert-butyl-4-methylphenol Gasoline Barley
2,6-Di-tert-Butyl-1-Hydroxy-4- Methylbenzene Gasoline Barley
dodecyl gallate Gasoline Barley octyl gallate Gasoline Potatoes
2-tert-butylhydroquinone Gasoline Potatoes 3,4,5-trihydroxybenzoic
acid n-propyl ester Gasoline Potatoes 1,2,3-trihydroxybenzene
Gasoline Potatoes 2-tert-butyl-4-hydroxyanisole Gasoline Potatoes
t-tert-butyl-4-methylphenol Gasoline Potatoes
2,6-Di-tert-Butyl-1-Hydroxy-4- Methylbenzene Gasoline Potatoes
dodecyl gallate Gasoline Potatoes octyl gallate Gasoline Biomass
2-tert-butylhydroquinone Gasoline Biomass 3,4,5-trihydroxybenzoic
acid n-propyl ester Gasoline Biomass 1,2,3-trihydroxybenzene
Gasoline Biomass 2-tert-butyl-4-hydroxyanisole Gasoline Biomass
t-tert-butyl-4-methylphenol Gasoline Biomass
2,6-Di-tert-Butyl-1-Hydroxy-4- Methylbenzene Gasoline Biomass
dodecyl gallate Gasoline Biomass octyl gallate
[0043] In one preferred embodiment, the fuel composition comprises
a gasoline, an ethanol produced from corn, and
6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline. In another preferred
embodiment, the fuel composition comprises a gasoline, an ethanol
produced from sugarcane, and
6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline. In yet another
preferred embodiment, the fuel composition comprises a gasoline, an
ethanol produced from a plant-derived, cellulose material and
6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline. In another preferred
embodiment, the fuel composition comprises a gasoline, an ethanol
produced from a biomass, and
6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline. Those skilled in the
art will appreciate that the concentration of antioxidants added to
the gasoline and ethanol blend can and will vary depending on the
source of ethanol. In one embodiment, the fuel composition
comprises a gasoline, an ethanol produced from a plant-derived,
cellulose material, and from about 20 ppm to about 1500 ppm of
6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline. In another
embodiment, the fuel composition comprises a gasoline, an ethanol
produced from corn, and from about 50 ppm to about 500 ppm of
6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline.
(c) Fuel Composition with Gasoline and at least two
Antioxidants
[0044] The present invention is also directed to a fuel composition
comprising a gasoline and an antioxidant mixture comprising at
least two antioxidants. In one embodiment, the fuel composition
comprises the gasoline as described in Part I and an antioxidant
mixture comprising at least two antioxidants as described in Part
II of the specification above. Of course those skilled in the art
will appreciate that the antioxidant mixtures will vary
considerably depending on the desired stabilization of the
gasoline. Examples of exemplary fuel compositions are presented in
Table 3 below. TABLE-US-00004 TABLE 3 Fuel Antioxidants Gasoline
2-tert-butylhydroquinone and 6-ethoxy-1,2-dihydro-
2,2,4-trimethylquinoline Gasoline 2-tert-butyl-4-hydroxyanisole and
2,6-Di-tert-Butyl-1- Hydroxy-4-Methylbenzene Gasoline
2-tert-butyl-4-hydroxyanisole and 2,6-Di-tert-Butyl-1-
Hydroxy-4-Methylbenzene and 6-ethoxy-1,2-dihydro-
2,2,4-trimethylquinoline Gasoline 2-tert-butyl-4-hydroxyanisole and
2,6-Di-tert-Butyl-1- Hydroxy-4-Methylbenzene and
6-ethoxy-1,2-dihydro- 2,2,4-trimethylquinoline and
2-tert-butylhydroquinone Gasoline 2-tert-butylhydroquinone and
6-ethoxy-1,2-dihydro- 2,2,4-trimethylquinoline and paraffin oil
Gasoline 2-tert-butyl-4-hydroxyanisole and 2,6-Di-tert-Butyl-1-
Hydroxy-4-Methylbenzene and paraffin oil Gasoline
6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline and 2-
tert-butylhydroquinone, 1,2-Propanediol, and paraffin oil
[0045] In one embodiment, the fuel composition comprises a gasoline
and an antioxidant mixture comprising 2-tert-butylhydroquinone
(TBHQ) and 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline (EQ). Such
an antioxidant mixture is sold under the trademark SANTOQUIN Q.RTM.
and may be purchased commercially from Novus International, Inc. In
another embodiment, the fuel composition comprises a gasoline and
an antioxidant mixture comprising 2-tert-butyl-4-hydroxyanisole
(BHA) and 2,6-Di-tert-Butyl-1-Hydroxy-4-Methylbenzene (BHT). In yet
another embodiment, the fuel composition comprises a gasoline and
an antioxidant mixture comprising 2-tert-butyl-4-hydroxyanisole,
2,6-Di-tert-Butyl-1-Hydroxy-4-Methylbenzene and
6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline. In a further
embodiment, the fuel composition comprises a gasoline and an
antioxidant mixture comprising 2-tert-butylhydroquinone,
6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline,
2-tert-butyl-4-hydroxyanisole, and
2,6-Di-tert-Butyl-1-Hydroxy-4-Methylbenzene.
[0046] In another embodiment, the fuel composition comprises a
gasoline and an antioxidant mixture comprising
2-tert-butylhydroquinone,
6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, and a paraffin oil.
In yet another embodiment, the fuel composition comprises a
gasoline and an antioxidant mixture comprising
2-tert-butyl-4-hydroxyanisole,
2,6-Di-tert-Butyl-1-Hydroxy-4-Methylbenzene, and a paraffin oil. In
a further embodiment, the fuel composition comprises a gasoline and
an antioxidant mixture comprising
6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline,
2-tert-butylhydroquinone, 1,2-Propanediol, and a paraffin oil.
[0047] Those skilled in the art will appreciate that the
concentration of antioxidants added to the gasoline can and will
vary depending on the desired stability of the fuel. In one
embodiment, the fuel composition comprises a gasoline and an
antioxidant mixture comprising from about 20 ppm to about 500 ppm
of 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, from about 20 ppm
to about 500 ppm of a mixture of 2-tert-butyl-4-hydroxyanisole and
2,6-Di-tert-Butyl-1-Hydroxy-4-Methylbenzene, and from about 10 to
about 60 ppm of 2-tert-butylhydroquinone. In another embodiment,
the fuel composition comprises a gasoline and an antioxidant
mixture comprising about 400 ppm of
6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, about 40 ppm of a
mixture of 2-tert-butyl-4-hydroxyanisole and
2,6-Di-tert-Butyl-1-Hydroxy-4-Methylbenzene, and about 50 ppm of
2-tert-butylhydroquinone. In yet another embodiment, the fuel
composition comprises a gasoline and an antioxidant mixture
comprising about 40 ppm of
6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, about 40 ppm of a
mixture of 2-tert-butyl-4-hydroxyanisole and
2,6-Di-tert-Butyl-1-Hydroxy-4-Methylbenzene, and about 50 ppm of
2-tert-butylhydroquinone.
(d) Fuel Composition with Gasoline, Ethanol and at Least Two
Antioxidants
[0048] In another embodiment, the fuel composition of the invention
comprises a gasoline and an ethanol blend in combination with an
antioxidant mixture comprising at least two antioxidants wherein
the fuel composition has substantially improved oxidative
stability. The fuel composition may comprise from about 15% to
about 95% by weight gasoline and from about 5% to about 85% by
weight ethanol. In another embodiment, the fuel composition may
comprise from about 80% to about 95% by weight gasoline and from
about 5% to about 20% by weight ethanol. In an alternative
embodiment, the fuel composition may comprise from about 90% to
about 95% by weight gasoline and from about 5% to about 10% by
weight ethanol. In one embodiment, the fuel composition comprises
any of the ethanols described in Part I in combination with a
gasoline and an antioxidant mixture comprising at least two
antioxidants as described in Part II of the specification above.
Exemplary fuel compositions are presented in Table 4 below.
TABLE-US-00005 TABLE 4 Ethanol Fuel Raw Fuel Material Antioxidants
Gasoline Corn 2-tert-butylhydroquinone and 6-ethoxy-1,2-
dihydro-2,2,4-trimethylquinoline Gasoline Corn
2-tert-butyl-4-hydroxyanisole and 2,6-Di-
tert-Butyl-1-Hydroxy-4-Methylbenzene Gasoline Corn
2-tert-butyl-4-hydroxyanisole, 2,6-Di-tert-
Butyl-1-Hydroxy-4-Methylbenzene and 6-
ethoxy-1,2-dihydro-2,2,4-trimethylquinoline Gasoline Corn
2-tert-butyl-4-hydroxyanisole, 2,6-Di-tert-
Butyl-1-Hydroxy-4-Methylbenzene, 6-
ethoxy-1,2-dihydro-2,2,4-trimethylquinoline and
2-tert-butylhydroquinone Gasoline Corn 2-tert-butylhydroquinone,
6-ethoxy-1,2- dihydro-2,2,4-trimethylquinoline and paraffin oil
Gasoline Corn 2-tert-butyl-4-hydroxyanisole, 2,6-Di-tert-
Butyl-1-Hydroxy-4-Methylbenzene and paraffin oil Gasoline Corn
6-ethoxy-1,2-dihydro-2,2,4- trimethylquinoline, 2-tert-
butylhydroquinone, 1,2-Propanediol, and paraffin oil Gasoline
Plant-derived 2-tert-butylhydroquinone and 6-ethoxy-1,2- Cellulose
dihydro-2,2,4-trimethylquinoline Material Gasoline Plant-derived
2-tert-butyl-4-hydroxyanisole and 2,6-Di- Cellulose
tert-Butyl-1-Hydroxy-4-Methylbenzene Material Gasoline
Plant-derived 2-tert-butyl-4-hydroxyanisole, 2,6-Di-tert- Cellulose
Butyl-1-Hydroxy-4-Methylbenzene and 6- Material
ethoxy-1,2-dihydro-2,2,4-trimethylquinoline Gasoline Plant-derived
2-tert-butyl-4-hydroxyanisole, 2,6-Di-tert- Cellulose
Butyl-1-Hydroxy-4-Methylbenzene, 6- Material
ethoxy-1,2-dihydro-2,2,4-trimethylquinoline and
2-tert-butylhydroquinone Gasoline Plant-derived
2-tert-butylhydroquinone, 6-ethoxy-1,2- Cellulose
dihydro-2,2,4-trimethylquinoline and Material paraffin oil Gasoline
Plant-derived 2-tert-butyl-4-hydroxyanisole, 2,6-Di-tert- Cellulose
Butyl-1-Hydroxy-4-Methylbenzene and Material paraffin oil Gasoline
Plant-derived 6-ethoxy-1,2-dihydro-2,2,4- Cellulose
trimethylquinoline, 2-tert- Material butylhydroquinone,
1,2-Propanediol, and paraffin oil Gasoline Sugarcane
2-tert-butylhydroquinone and 6-ethoxy-1,2-
dihydro-2,2,4-trimethylquinoline Gasoline Sugarcane
2-tert-butyl-4-hydroxyanisole and 2,6-Di-
tert-Butyl-1-Hydroxy-4-Methylbenzene Gasoline Sugarcane
2-tert-butyl-4-hydroxyanisole, 2,6-Di-tert-
Butyl-1-Hydroxy-4-Methylbenzene and 6-
ethoxy-1,2-dihydro-2,2,4-trimethylquinoline Gasoline Sugarcane
2-tert-butyl-4-hydroxyanisole, 2,6-Di-tert-
Butyl-1-Hydroxy-4-Methylbenzene, 6-
ethoxy-1,2-dihydro-2,2,4-trimethylquinoline and
2-tert-butylhydroquinone Gasoline Sugarcane
2-tert-butylhydroquinone, 6-ethoxy-1,2-
dihydro-2,2,4-trimethylquinoline and paraffin oil Gasoline
Sugarcane 2-tert-butyl-4-hydroxyanisole, 2,6-Di-tert-
Butyl-1-Hydroxy-4-Methylbenzene and paraffin oil Gasoline Sugarcane
6-ethoxy-1,2-dihydro-2,2,4- trimethylquinoline, 2-tert-
butylhydroquinone, 1,2-Propanediol, and paraffin oil Gasoline Grain
sorghum 2-tert-butylhydroquinone and 6-ethoxy-1,2-
dihydro-2,2,4-trimethylquinoline Gasoline Grain sorghum
2-tert-butyl-4-hydroxyanisole and 2,6-Di-
tert-Butyl-1-Hydroxy-4-Methylbenzene Gasoline Grain sorghum
2-tert-butyl-4-hydroxyanisole, 2,6-Di-tert-
Butyl-1-Hydroxy-4-Methylbenzene and 6-
ethoxy-1,2-dihydro-2,2,4-trimethylquinoline Gasoline Grain sorghum
2-tert-butyl-4-hydroxyanisole, 2,6-Di-tert-
Butyl-1-Hydroxy-4-Methylbenzene, 6-
ethoxy-1,2-dihydro-2,2,4-trimethylquinoline and
2-tert-butylhydroquinone Gasoline Grain sorghum
2-tert-butylhydroquinone, 6-ethoxy-1,2-
dihydro-2,2,4-trimethylquinoline and paraffin oil Gasoline Grain
sorghum 2-tert-butyl-4-hydroxyanisole, 2,6-Di-tert-
Butyl-1-Hydroxy-4-Methylbenzene and paraffin oil Gasoline Grain
sorghum 6-ethoxy-1,2-dihydro-2,2,4- trimethylquinoline, 2-tert-
butylhydroquinone, 1,2-Propanediol, and paraffin oil Gasoline Wheat
2-tert-butylhydroquinone and 6-ethoxy-1,2-
dihydro-2,2,4-trimethylquinoline Gasoline Wheat
2-tert-butyl-4-hydroxyanisole and 2,6-Di-
tert-Butyl-1-Hydroxy-4-Methylbenzene Gasoline Wheat
2-tert-butyl-4-hydroxyanisole, 2,6-Di-tert-
Butyl-1-Hydroxy-4-Methylbenzene and 6-
ethoxy-1,2-dihydro-2,2,4-trimethylquinoline Gasoline Wheat
2-tert-butyl-4-hydroxyanisole, 2,6-Di-tert-
Butyl-1-Hydroxy-4-Methylbenzene, 6-
ethoxy-1,2-dihydro-2,2,4-trimethylquinoline and
2-tert-butylhydroquinone Gasoline Wheat 2-tert-butylhydroquinone,
6-ethoxy-1,2- dihydro-2,2,4-trimethylquinoline and paraffin oil
Gasoline Wheat 2-tert-butyl-4-hydroxyanisole, 2,6-Di-tert-
Butyl-1-Hydroxy-4-Methylbenzene and paraffin oil Gasoline Wheat
6-ethoxy-1,2-dihydro-2,2,4- trimethylquinoline, 2-tert-
butylhydroquinone, 1,2-Propanediol, and paraffin oil Gasoline
Barley 2-tert-butylhydroquinone and 6-ethoxy-1,2-
dihydro-2,2,4-trimethylquinoline Gasoline Barley
2-tert-butyl-4-hydroxyanisole and 2,6-Di-
tert-Butyl-1-Hydroxy-4-Methylbenzene Gasoline Barley
2-tert-butyl-4-hydroxyanisole, 2,6-Di-tert-
Butyl-1-Hydroxy-4-Methylbenzene and 6-
ethoxy-1,2-dihydro-2,2,4-trimethylquinoline Gasoline Barley
2-tert-butyl-4-hydroxyanisole, 2,6-Di-tert-
Butyl-1-Hydroxy-4-Methylbenzene, 6-
ethoxy-1,2-dihydro-2,2,4-trimethylquinoline and
2-tert-butylhydroquinone Gasoline Barley 2-tert-butylhydroquinone,
6-ethoxy-1,2- dihydro-2,2,4-trimethylquinoline and paraffin oil
Gasoline Barley 2-tert-butyl-4-hydroxyanisole, 2,6-Di-tert-
Butyl-1-Hydroxy-4-Methylbenzene and paraffin oil Gasoline Barley
6-ethoxy-1,2-dihydro-2,2,4- trimethylquinoline, 2-tert-
butylhydroquinone, 1,2-Propanediol, and paraffin oil Gasoline
Potatoes 2-tert-butylhydroquinone and 6-ethoxy-1,2-
dihydro-2,2,4-trimethylquinoline Gasoline Potatoes
2-tert-butyl-4-hydroxyanisole and 2,6-Di-
tert-Butyl-1-Hydroxy-4-Methylbenzene Gasoline Potatoes
2-tert-butyl-4-hydroxyanisole, 2,6-Di-tert-
Butyl-1-Hydroxy-4-Methylbenzene and 6-
ethoxy-1,2-dihydro-2,2,4-trimethylquinoline Gasoline Potatoes
2-tert-butyl-4-hydroxyanisole, 2,6-Di-tert-
Butyl-1-Hydroxy-4-Methylbenzene, 6-
ethoxy-1,2-dihydro-2,2,4-trimethylquinoline and
2-tert-butylhydroquinone Gasoline Potatoes
2-tert-butylhydroquinone, 6-ethoxy-1,2-
dihydro-2,2,4-trimethylquinoline and paraffin oil Gasoline Potatoes
2-tert-butyl-4-hydroxyanisole, 2,6-Di-tert-
Butyl-1-Hydroxy-4-Methylbenzene and paraffin oil Gasoline Potatoes
6-ethoxy-1,2-dihydro-2,2,4- trimethylquinoline, 2-tert-
butylhydroquinone, 1,2-Propanediol, and paraffin oil Gasoline
Biomass 2-tert-butylhydroquinone and 6-ethoxy-1,2-
dihydro-2,2,4-trimethylquinoline Gasoline Biomass
2-tert-butyl-4-hydroxyanisole and 2,6-Di-
tert-Butyl-1-Hydroxy-4-Methylbenzene Gasoline Biomass
2-tert-butyl-4-hydroxyanisole, 2,6-Di-tert-
Butyl-1-Hydroxy-4-Methylbenzene, and 6-
ethoxy-1,2-dihydro-2,2,4-trimethylquinoline Gasoline Biomass
2-tert-butyl-4-hydroxyanisole, 2,6-Di-tert-
Butyl-1-Hydroxy-4-Methylbenzene, 6-
ethoxy-1,2-dihydro-2,2,4-trimethylquinoline and
2-tert-butylhydroquinone Gasoline Biomass 2-tert-butylhydroquinone,
6-ethoxy-1,2- dihydro-2,2,4-trimethylquinoline and paraffin oil
Gasoline Biomass 2-tert-butyl-4-hydroxyanisole, 2,6-Di-tert-
Butyl-1-Hydroxy-4-Methylbenzene and paraffin oil Gasoline Biomass
6-ethoxy-1,2-dihydro-2,2,4- trimethylquinoline and 2-tert-
butylhydroquinone, 1,2-Propanediol, and paraffin oil
[0049] In one embodiment, the fuel composition comprises a
gasoline, an ethanol produced from a plant-derived cellulose
material, and an antioxidant mixture comprising
2-tert-butylhydroquinone (TBHQ) and
6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline (EQ). In another
embodiment, the fuel composition comprises a gasoline, an ethanol
produced from a plant-derived cellulose material, and an
antioxidant mixture comprising 2-tert-butyl-4-hydroxyanisole (BHA)
and 2,6-Di-tert-Butyl-1-Hydroxy-4-Methylbenzene (BHT). In yet
another embodiment, the fuel composition comprises a gasoline, an
ethanol produced from a plant-derived cellulose material, and an
antioxidant mixture comprising 2-tert-butyl-4-hydroxyanisole,
2,6-Di-tert-Butyl-1-Hydroxy-4-Methylbenzene and
6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline. In a further
embodiment, the fuel composition comprises a gasoline, an ethanol
produced from a plant-derived cellulose material, and an
antioxidant mixture comprising 2-tert-butylhydroquinone,
6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline,
2-tert-butyl-4-hydroxyanisole, and
2,6-Di-tert-Butyl-1-Hydroxy-4-Methylbenzene.
[0050] In another embodiment, the fuel composition comprises a
gasoline, an ethanol produced from a plant-derived cellulose
material, and an antioxidant mixture comprising
2-tert-butylhydroquinone,
6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, and a paraffin oil.
In yet another embodiment, the fuel composition comprises a
gasoline, an ethanol produced from a plant-derived cellulose
material, and an antioxidant mixture comprising
2-tert-butyl-4-hydroxyanisole,
2,6-Di-tert-Butyl-1-Hydroxy-4-Methylbenzene, and a paraffin oil. In
a further embodiment, the fuel composition comprises a gasoline, an
ethanol produced from a plant-derived cellulose material, and an
antioxidant mixture comprising
6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline,
2-tert-butylhydroquinone, 1,2-Propanediol, and a paraffin oil.
Gumming
[0051] Those skilled in the art will appreciate that the
concentration of antioxidants added to the gasoline and ethanol
blend will generally be the amount needed to achieve an induction
period of greater than about 1400 minutes. In one embodiment, the
fuel composition comprises a gasoline and ethanol blend, and an
antioxidant mixture comprising from about 20 ppm to about 500 ppm
of 6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, from about 20 ppm
to about 500 ppm of a mixture of 2-tert-butyl-4-hydroxyanisole and
2,6-Di-tert-Butyl-1-Hydroxy-4-Methylbenzene, and from about 10 to
about 60 ppm of 2-tert-butylhydroquinone.
IV. Additional Agents
[0052] The fuel compositions of the invention may contain
additional agents that enhance one or more characteristics of the
fuel. Those skilled in the art will appreciate that the selection
of the particular agent may vary considerably depending on the type
of fuel used. Suitable additives, for example, may include, but are
not limited to, one or more octane improvers, demulsifiers,
corrosion inhibitors and/or metal deactivators, cold flow
improvers, and the like, as described below.
[0053] Thermal stabilizers may optionally be added to the gasoline
composition. Suitable thermal stabilizers known in the art include
liquid mixtures of alkyl phenols, including 2-tert-butylphenol,
2,6-di-tert-butylphenol, 2-tert-butyl-4-n-butylphenol,
2,4,6-tri-tert-butylphenol, and 2,6-di-tert-butyl-4-n-butylphenol.
Other commercially available hindered phenolic antioxidants that
also exhibit a thermal stability effect include
2,6-di-t-butyl-4-methylphenol; 2,6-di-t-butylphenol;
2,2'-methylene-bis(6-t-butyl-4-methylphenol); n-octadecyl
3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate;
1,1,3-tris(3-t-butyl-6-methyl-4-hydroxyphenyl)butane;
pentaerythrityl
tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate];
di-n-octadecyl (3,5-di-t-butyl-4-hydroxybenzyl)phosphonate;
2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)mesitylene; and
tris(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate. Additional
suitable thermal stabilizers include: pentaerythritol co-esters
derived from pentaerythritol, (3-alkyl-4-hydroxyphenyl)-alkanoic
acids and alkylthioalkanoic acids or lower alkyl esters of such
acids which are useful as stabilizers of organic material normally
susceptible to oxidative and/or thermal deterioration.
[0054] Certain lubricating fluid base stocks are known in the art
to exhibit high thermal stability and as such, may be beneficial in
certain embodiments of the invention. Suitable base stocks include
polyalphaolefins, dibasic acid esters, polyol esters, alkylated
aromatics, polyalkylene glycols, and phosphate esters.
[0055] A variety of polyalphaolefins may be utilized in the fuel
composition of the invention. Polyalphaolefins are hydrocarbon
polymers that contain no sulfur, phosphorus, or metals.
[0056] In another embodiment, the fuel composition may optionally
include a carburetor detergent. Carburetor deposits may form in the
throttle body and plate, idle air circuit, and in the metering
orifices and jets. These deposits are a combination of contaminants
from dust and engine exhaust, held together by gums formed from
unsaturated hydrocarbons in the fuel. They can alter the air/fuel
ratio, cause rough idling, increased fuel consumption, and
increased exhaust emissions. Carburetor detergents appropriate for
use in the invention typically prevent deposits from forming and
remove deposits already formed.
[0057] In yet another embodiment, the fuel composition may
optionally include a fuel injector detergent. Fuel injectors are
very sensitive to deposits that can reduce fuel flow and alter the
injector spray pattern. These deposits can make vehicles difficult
to start, cause severe drive ability problems, and increase fuel
consumption and exhaust emissions. Suitable detergents include
amine detergents and polymeric dispersants.
[0058] In another embodiment, the fuel composition may optionally
include an agent to minimize combustion chamber deposits.
Combustion chamber deposits can cause an increase in the octane
number requirement for vehicles as they accumulate miles. These
deposits accumulate in the end-gas zone and injection port area.
Suitable agents that minimize combustion chamber deposits include
polyetheramine and other proprietary additives are known to reduce
the magnitude of combustion chamber deposits.
[0059] The gasoline fuel compositions of various embodiments
advantageously may contain one or more drive ability additives,
such as anti-knock, anti-run-on, anti-pre-ignition, and
anti-misfire additives that directly affect the combustion process.
Anti-knock additives include lead alkyls that are no longer used in
the United States. These and other metallic anti-knock additives
are typically used at dosages of roughly 0.2 g metal/liter of fuel
(or about 0.1 wt % or 1000 ppm). A typical octane number
enhancement at this dosage level is 3 units for both Research
Octane Number (RON) and Motor Octane Number (MON). Several organic
compounds are also known to have anti-knock activity. These include
aromatic amines, alcohols, and ethers that can be employed at
dosages in the 1000 ppm range. These additives work by transferring
hydrogen to quench reactive radicals. Oxygenates such as methanol
and MTBE also increase octane number but these are used at such
high dosages that they are not really additives but blend
components. Pre-ignition is generally caused by the presence of
combustion chamber deposits and is treated using combustion chamber
detergents and by raising octane number.
[0060] The fuel composition may include a variety of demulsifiers.
Demulsifiers are molecules that aid the separation of oil from
water usually at very low concentrations. They prevent formation of
a water and oil mixture. Several demulsifiers are available for use
in the fuel formulations of various embodiments, including, for
example, organic sulfonates, polyoxyalkylene glycols, oxyalkylated
phenolic resins, and like materials. Exemplary formulations include
alkylaryl sulfonates, polyoxyalkylene glycols and oxyalkylated
alkylphenolic resins, such as are available commercially from Baker
Petrolite Corporation of Sugar Land, Tex. as TOLAD.RTM..
[0061] Several corrosion inhibitors are suitable for use in the
fuel formulations of various embodiments. Suitable corrosion
inhibitors include dimer and trimer acids, such as are produced
from tall oil fatty acids, oleic acid, linoleic acid, or the like.
Other suitable corrosion inhibitors are the alkenyl succinic acid
and alkenyl succinic anhydride corrosion inhibitors such as, for
example, tetrapropenylsuccinic acid, tetrapropenylsuccinic
anhydride, tetradecenylsuccinic acid, tetradecenylsuccinic
anhydride, hexadecenylsuccinic acid, hexadecenylsuccinic anhydride,
and the like. Also useful are the half esters of alkenyl succinic
acids having 8 to 24 carbon atoms in the alkenyl group with
alcohols such as the polyglycols.
[0062] If desired, the fuel compositions may contain a metal
deactivator of the type having the ability to form complexes with
heavy metals such as copper and the like. Typically, the metal
deactivators used are gasoline soluble
N,N'-disalicylidene-1,2-alkanediamines or
N,N'-disalicylidene-1,2-cycloalkanediamines, or mixtures thereof.
Examples include N,N'-disalicylidene-1,2-ethanediamine,
N,N'-disalicylidene-1,2-propanediamine,
N,N'-disalicylidene-1,2-cyclo-hex-anediamine, and
N,N''-disalicylidene-N'-methyl-dipropylene-triamine.
[0063] The fuel composition may include a variety of oxygenates.
Oxygenates are added to gasoline to improve octane number and to
reduce emissions of CO. These include various alcohols and ethers
that are typically blended with gasoline to produce an oxygen
content typically of up to about 2 weight percent, although higher
concentrations may be desirable in certain embodiments. Suitable
examples of oxygenates include methanol, ethanol, methyl tertiary
butyl ether (MTBE), ethyl tertiary butyl ether (ETBE), diisopropyl
ether (DIPE), and tertiary amyl methyl ether (TAME).
[0064] The amount of additive that may be included in the various
fuel compositions of the invention can and will vary. The amount
will typically be the amount that is sufficient to impart the
desired functional property to the fuel composition.
V. Methods for Improving Oxidative Stability and Reducing Gum
Formation
[0065] As demonstrated in the examples, the fuel compositions of
the invention typically have increased oxidative stability. In
addition to having increased oxidative stability, depending on the
embodiment, the fuel compositions may also have reduced gumming.
The method of increasing the oxidative stability of a fuel
composition and/or reducing gumming typically comprises contacting
a gasoline with an antioxidant mixture that increases the oxidative
stability of the fuel. In another embodiment, the method of
increasing the oxidative stability of a fuel composition and/or
reducing gumming typically comprises contacting a gasoline and
ethanol blend with an antioxidant mixture that increases the
oxidative stability of the fuel.
[0066] Methods for determining oxidative stability of a fuel
composition and/or a reduction in gum formation may be determined
by methods generally known in the art, such as, for example, by the
ASTM test D525 for Oxidation Stability. Potential gum is indicative
of oxidation, and may be determined by the ASTM test D525 for
Oxidation Stability as described more fully in the Examples. For
automotive gasoline, the potential gum may be expressed as the
"induction period" (sometimes called the breakdown time). This is a
measure of the time (in minutes) elapsed during the accelerated
test until the fuel absorbs oxygen rapidly. The ASTM test D525 for
Oxidation Stability of Gasoline (Induction Period Method) utilizes
accelerated oxidation conditions to determine the oxidation
stability of gasoline. This method may be utilized by a skilled
artisan to formulate blends of antioxidants having a suitable
concentration of each ingredient in order for the antioxidant blend
to impart the desired oxidative stability for the fuel of the
invention. In one embodiment, the fuel compositions of the present
invention have an induction time greater than 450 minutes, greater
than about 500 minutes, greater than about 550 minutes, greater
than about 600 minutes, greater than about 650 minutes, greater
than about 700 minutes, greater than about 750 minutes, greater
than about 800 minutes, greater than about 850 minutes, greater
than about 900 minutes, greater than about 950 minutes, greater
than about 1000 minutes, greater than about 1050 minutes, greater
than about 1100 minutes, greater than about 1150 minutes, greater
than about 1200 minutes, greater than about 1250 minutes, greater
than about 1300 minutes, greater than about 1350 minutes, greater
than about 1400 minutes, or greater than about 1450 minutes.
Definitions
[0067] To facilitate understanding of the invention, a number of
terms and abbreviations as used herein are defined below:
[0068] The term "Induction time" denotes the resistance of the fuel
to oxidation.
[0069] The term "Oxidative Stability" refers to the ability to
decrease the rate of fuel oxidation.
[0070] The term "PPM" stands for parts per million.
[0071] As various changes could be made in the above fuel
compositions, products and methods without departing from the scope
of the invention, it is intended that all matter contained in the
above description shall be interpreted as illustrative and not in a
limiting sense.
EXAMPLES
[0072] The following examples illustrate various iterations of fuel
compositions having improved oxidative stability.
Example 1
Improved Oxidative Stability of Fuel Compositions Comprising
Ethoxyquin
[0073] The ability of the antioxidant
6-ethoxy-1,2-dihydro-2,2,4-trimethylquinoline, also known as
ethoxyquin, to stabilize gasoline mixtures was tested. Ethoxyquin
was added at concentrations of 0.01% (100 ppm) or 0.005% (50 ppm)
to gasoline compositions comprising from 0% to 85% of ethanol. The
base fuel used for blending was an ethanol blending Reformulated
gasoline Blendstock for Oxygen Blending (RBOB). The fuel was
obtained from the terminal prior to the addition of any detergent
additives or oxygenates. The fuel was filtered through Alumina to
remove any antioxidant additives that would be present from the
refinery blendstock fuels. (See Examples 2 and 3 for additional
information about the base fuel used in this study.)
[0074] The oxidative stability of each of the formulations (see
Table 1) was tested using the ASTM D 525 Test Method for Oxidation
Stability of Gasoline (Induction Period Method). Analyses were
performed according to the listed ASTM test procedures with no
modifications or deviations. Briefly, a sample of gasoline was
placed in a glass sample container in a pressure vessel and oxygen
was introduced to a pressure of about 100 psi. The charged pressure
vessel was placed in a 100.degree. C. (212.degree. F.) bath and the
pressure was continuously monitored for 24 hours (1440 minutes).
The break point of the fuel was determined when a specified drop in
pressure in 15 minutes was observed. The number of minutes required
to reach this point was the induction period.
[0075] Table 1 presents the induction periods, maximum and minimum
pressures, and indicates whether or not a break point was observed.
Ethoxyquin (ETX) increased the induction period of fuels comprising
0%, 10%, and 20% ethanol about three-fold. Fuels comprising 40% or
more ethanol were stable with and without the antioxidant. FIGS.
1-3 present pressure versus time plots in the absence or presence
of ethoxyquin of the different fuel compositions. The plots clearly
indicate the breaking points or lack of breaking points in the
various formulations. TABLE-US-00006 TABLE 1 ASTM D 525 Test
Results. Sample Induction Max Min Run Composition (%) Period
Pressure Pressure # Fuel EtOH ETX (min) Break (psi) (psi) 1 100 0 0
238 YES 148.9 54.5 2 99.99 0 0.01 718 YES 150.5 54.4 3 89.99 10
0.01 894 YES 163.7 68.3 4 90 10 0 315 YES 162.9 64.4 5 79.99 20
0.01 >1440 No Break 172.7 80.8 6 80 20 0 582 YES 168.0 68.3 7
59.99 40 0.01 >1440 No Break 168.8 114.7 8 60 40 0 >1440 No
Break 166.9 66.4 9 39.99 60 0.01 >1440 No Break 166.1 164.4 10
40 60 0 >1440 No Break 166.0 81.8 11 14.99 85 0.01 >1440 No
Break 158.3 157.4 12 15 85 0 >1440 No Break 161.1 150.2 13
14.995 85 0.005 >1440 No Break 158.5 157.0 14 39.995 60 0.005
>1440 No Break 165.0 1337 15 79.995 20 0.005 >1440 No Break
169.0 68.2 16 89.995 10 0.005 563 YES 170.4 69.3
Example 2
Distillation Profile of Base Fuel
[0076] The base fuel used in Example 1 was characterized by
determining its distillation profile. This was determined using the
ASTM D 86 Standard Test Method for Distillation of Petroleum
Products at Atmospheric Pressure. For this, a sample was placed in
a round bottom flask and heated at a rate specified for samples
with its vapor pressure characteristics. Temperatures (.degree. F.)
were recorded when the first drop was collected (initial boiling
point; IBP), at recovered volumes representing 5% to 95% of the
initial volume, and at the end of the test (final boiling point;
FBP).
[0077] The distillation profile is presented in Table 2, as well as
the percentages of recovery, residue, and loss. TABLE-US-00007
TABLE 2 ASTM D 86 Distillation Profile of Fuel. Measured Unit Value
IBP .degree. F. 83.7 5% .degree. F. 100.3 10% .degree. F. 114.7 15%
.degree. F. 124.5 20% .degree. F. 134.2 30% .degree. F. 154.8 40%
.degree. F. 177.4 50% .degree. F. 201.5 60% .degree. F. 227.9 70%
.degree. F. 258.6 80% .degree. F. 299.0 90% .degree. F. 349.5 95%
.degree. F. 383.6 FBP .degree. F. 421.9 Recovery % 96.5 Residue %
0.9 Loss % 2.6
Example 3
Composition of Base Fuel
[0078] The base fuel used in Example 1 was characterized by
determining its composition of hydrocarbons. This analysis was
performed using the ASTM D 6729 Test Method for Determination of
Individual Components in Spark Ignition Engine Fuels by Capillary
High-Resolution Gas Chromatography. The method uses a 100 meter
capillary column and flame ionization detector. A total of 385
compounds were identified. The compounds are summarized by group in
Table 3. The compounds are summarized by number of carbons in Table
4, and composite in Table 5. TABLE-US-00008 TABLE 3 Base Fuel
Composition: Summary by Group. Group % Weight % Volume % Mole
Paraffin 12.957 14.844 16.232 I-Paraffins 35.824 39.009 36.675
Aromatics 29.550 24.535 24.978 Mono-Aromatics 26.270 22.016 22.559
Naphthalenes 1.400 1.007 1.003 Naphtheno/Olefino-Benz 1.247 1.025
0.920 Indenes 0.520 0.394 0.429 Naphthenes 6.501 6.201 6.239
Mono-Naphthenes 6.046 5.776 5.894 Di/Bicyclo-Naphthenes 0.051 0.046
0.032 Olefins 10.021 10.702 12.018 n-Olefins 3.711 4.066 4.658
Iso-Olefins 4.528 4.877 5.410 Naphtheno-Olefins 0.692 0.649 0.863
Di-Olefins 0.455 0.462 0.497 Oxygenates 0.131 0.129 0.148
[0079] TABLE-US-00009 TABLE 4 Base Fuel Composition: Summary by
Carbon. Carbon # % Weight % Volume % Mole C4 4.343 5.480 7.299 C5
14.084 16.206 19.178 C6 14.295 15.409 16.349 C7 19.729 19.798
19.652 C8 17.146 16.333 15.141 C9 11.800 10.611 9.369 C10 7.890
6.713 5.747 C11 3.242 2.735 2.120 C12 2.083 1.775 1.238 C13 0.371
0.359 0.196
[0080] TABLE-US-00010 TABLE 5 Base Fuel Composition: Composite by
Carbon. Group Carbon # % Weight % Volume % Mole Paraffin C4 3.601
4.549 6.039 C5 2.888 3.372 3.901 C6 2.889 3.204 3.268 C7 1.729
1.849 1.682 C8 0.700 0.728 0.597 C9 0.348 0.355 0.265 C10 0.232
0.233 0.159 C11 0.164 0.162 0.103 C12 0.121 0.118 0.069 C13 0.283
0.274 0.150 I-Paraffins C4 0.396 0.520 0.664 C5 6.697 7.905 9.047
C6 7.629 8.485 8.628 C7 8.657 9.319 8.421 C8 7.634 7.961 6.514 C9
2.539 2.578 1.929 C10 1.177 1.173 0.806 C11 0.810 0.792 0.506 C12
0.198 0.192 0.113 C13 0.088 0.085 0.047 Aromatics C12 0.113 0.093
0.068 Mono-Aromatics C6 0.715 0.595 0.892 C7 4.284 3.613 4.532 C8
7.001 5.899 6.428 C9 7.429 6.233 6.025 C10 3.866 3.238 2.807 C11
1.502 1.227 0.991 C12 1.474 1.211 0.885 Naphthalenes C10 0.662
0.478 0.500 C11 0.738 0.529 0.502 Naphtheno/Olefino-Benzs C10 1.247
1.025 0.920 Indenes C10 0.520 0.394 0.429 Naphthenes C8 0.054 0.050
0.047 C9 0.322 0.302 0.249 C11 0.028 0.026 0.018 Mono-Naphthenes C5
0.434 0.426 0.604 C6 0.580 0.544 0.671 C7 2.954 2.848 2.933 C8
1.264 1.200 1.098 C9 0.559 0.526 0.432 C10 0.079 0.071 0.055 C12
0.176 0.161 0.102 Di/Bicyclo-Naphthenes C10 0.051 0.046 0.032
Olefins C4 0.000 0.000 0.000 C6 0.046 0.049 0.053 C7 0.240 0.250
0.231 C8 0.170 0.169 0.163 C9 0.179 0.181 0.142 n-Olefins C4 0.334
0.400 0.580 C5 1.650 1.860 2.293 C6 0.881 0.942 1.021 C7 0.432
0.448 0.429 C8 0.182 0.185 0.158 C9 0.216 0.214 0.167 C10 0.017
0.017 0.012 Iso-Olefins C5 2.015 2.246 2.800 C6 1.048 1.115 1.214
C7 1.217 1.255 1.208 C9 0.208 0.221 0.161 C10 0.040 0.040 0.028
Naphtheno-Olefins C5 0.180 0.171 0.258 C6 0.496 0.463 0.589 C7
0.016 0.015 0.016 Di-Olefins C5 0.101 0.109 0.145 C6 0.011 0.012
0.013 C7 0.200 0.201 0.201 C8 0.143 0.141 0.138 Oxygenates C4 0.012
0.011 0.016 C5 0.119 0.117 0.132
* * * * *