Note: Descriptions are shown in the official language in which they were submitted.
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A METHOD OF REDUCING PARTICULATE EMISSIONS IN INTERNAL
COMBUSTION ENGINES
This invention relates to a method for reducing particulate emissions in an
internal combustion engine. More particularly, this invention relates to a
method for reducing particulate emissions in an internal combustion engine
which comprises operating the internal combustion engine with a particulate
emission-reducing fuel composition of the present invention.
BACKGROUND OF THE INVENTION
Millions of internal combustion engines are in operation worldwide for the
purposes of. transportation, power generation, and so on. These engines rely
almost exclusively on hydrocarbon fuels such as gasoline or diesel. One of the
drawbacks of the operation of these types of engines is due to the emissions
they produce. Particulate emissions are solid or liquid emissions (which may
form from emission gases either before or after emission from the engine
exhaust system). Of particular concern are particles which are emitted in the
size range below 100 nanometers. Particles in this size range are referred to
as "ultrafine" and are the focus of a great deal of attention due to potential
environmental and public health concerns.
In the past, changes in engine technology have been relied upon to reduce
particulate emissions. Some examples of this are improved combustion
chamber design, high pressure injection systems, and advanced engine control
strategies. In addition, fuel and Tube oil compositions have been changed in
some cases (primarily through reduction of sulfur levels) to reduce these
emissions. Currently, exhaust particulate filters are being proposed for use
on
a widespread basis to further reduce levels of particulate emissions.
One of the most fundamental methods for reducing particulate emissions is by
improving the combustion properties of a fuel itself. Historically, the use of
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additives has been a common technique for improving the combustion
performance of a given fuel for use in internal combustion engines. Although
such additives (e.g. Ferrocene, Tetra-Ethyl Lead, MTBE, etc.) have been widely
used, they often possess serious drawbacks (harmful to public health and the
environment, excessive cost, hazardous storage/handling issues, damage to
engine and exhaust system components, etc.). The additive disclosed and
employed herein possesses none of these drawbacks, and can be used with a
wide variety of other existing additives.
In order to produce a finished hydrocarbon fuel, the producer must highly
refine
a base feedstock (e.g. crude oil) to create a final product. The final
properties
of this fuel are largely determined by the refining process used in its
production.
By improving combustion performance, the additive employed in the present
invention may be added to lower quality fuels to maintain adequate combustion
performance of the finished fuel composition. This allows for a lower degree
of
base stock refining, thus reducing the total cost per volume required to
produce
a finished fuel.
SUMMARY OF THE INVENTION
The present invention provides a method for reducing particulate emissions in
an internal combustion engine. More particularly, this invention relates to a
method for reducing particulate emissions in an internal combustion engine
which comprises operating the internal combustion engine with a fuel
composition comprising:
a). a major amount of hydrocarbons boiling in the gasoline or diesel
range and
b). an effective particulate emission-reducing amount of an alkylene
oxide-adducted hydrocarbyl amide having from 3 to 50 moles of
alkylene oxide per mole of hydrocarbyl amide.
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In an alternative embodiment, the present invention is directed to the use of
an alkylene oxide-adducted hydrocarbyl amide in a fuel composition to reduce
particulate emissions in an internal combustion engine.
In accordance with another aspect, there is provided a method of reducing the
particulate emissions in an internal combustion engine, said method
comprising operating the internal combustion engine with a fuel composition
comprising a major amount of hydrocarbons boiling in the gasoline or diesel
range and an effective particulate emissions-reducing amount of an alkylene
oxide-adducted hydrocarbyl amide having the following structure:
I I (Ri- 0)`- (Rs O)e- H
R-C--N
(R'- )d .....' (R"- O) -- H
wherein,
R is a hydrocarbyl group having from 4 to 75 carbon atoms;
R' is a divalent alkylene group having from 1 to 10 carbon atoms;
R" is a divalent alkylene group having from 2 to 5 carbon atoms;
c and d are independently 0 or 1; and
e and f are independently integers from 0 to 50, such that the total of e
plus f ranges from 3 to 50,
the alkylene oxide-adducted hydrocarbyl amide having from 3 to 50 moles of
alkylene oxide per mole of hydrocarbyl amide, wherein the alkylene oxide-
adducted hydrocarbyl amide is present in the fuel in the range of from 10 to
1,000 ppm by weight.
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Among other factors, the present invention is based on the discovery that
particulate emissions can be effectively reduced in internal combustion
engines by employing the unique method described herein. Moreover, the
method of the present invention is suitable for use in removing such
particulate emissions in spark ignition engines (including conventional port
fuel injection and direct injection spark ignition engines) and in compression
ignition engines (including direct and indirect injection diesel engines as
well
as homogeneous charge compression ignition engines.
DETAILED DESCRIPTION OF THE INVENTION
As stated above, the present invention involves a method for reducing the
particulate emissions in an internal combustion engine, such as gasoline or
diesel engines, particularly port fuel injected spark ignition engines, direct
injection spark ignition engines or compression ignition engines.
Prior to discussing the present invention in detail, the following terms will
have the following meanings unless expressly stated to the contrary.
Definitions
The term "amino" refers to the group: -NH2.
The term "hydrocarbyl" refers to an organic radical primarily composed of
carbon and hydrogen which may be aliphatic, alicyclic, aromatic or
combinations thereof, e.g., aralkyl or alkaryl. Such hydrocarbyl groups may
also contain aliphatic unsaturation, i.e., olefinic or acetylenic
unsaturation,
and may contain minor amounts of heteroatoms, such as oxygen or nitrogen,
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or halogens, such as chlorine. When used in conjunction with carboxylic fatty
acids, hydrocarbyl will also include olefinic unsaturation.
The term "alkyl" refers to both straight- and branched-chain alkyl groups.
The term "lower alkyl' refers to alkyl groups having 1 to about 6 carbon atoms
and includes primary, secondary and tertiary alkyl groups. Typical lower alkyl
groups include, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl,
sec-butyl, t-butyl, n-pentyl, n-hexyl and the like.
The term "polyalkyl" refers to alkyl groups which are generally derived from
polyolefins which are polymers or copolymers of mono-olefins, particularly
1-mono-olefins, such as ethylene, propylene, butylene, and the like.
Preferably, the mono-olefin employed will have from about 2 to 24 carbon
atoms, and more preferably, from about 3 to 12 carbon atoms. More
preferred mono-olefins include propylene, butylene, particularly isobutylene,
1-octene, and 1-decene. Polyolefins prepared from such mono-olefins
include polypropylene, polybutene, especially polyisobutene, and the
polyalphaolefins produced from 1-octene and 1-decene.
The term "alkenyl" refers to an alkyl group with unsaturation.
The term "alkylene oxide" refers to a compound having the formula:
/0
R1 -C H CH R2
wherein R1 and R2 are each independently hydrogen or lower alkyl having
from 1 to about 6 carbon atoms.
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The term "highly reactive polyisobutene" refers to a polyisobutene wherein at
least about 20% of the residual olefinic double bonds are of the vinylidene
type, i.e., represented by the formula:
-CH2-C=CH2
CH3
The term "succinimide" is understood in the art to include many of the amide,
imide, etc. species that are also formed by the reaction of a succinic
anhydride with an amine and is so used herein. The predominant product,
however, is succinimide and this term has been generally accepted as
meaning the product of a reaction of an alkenyl- or alkyl-substituted succinic
acid or anhydride with a polyamine. Alkenyl or alkyl succinimides are
disclosed in numerous references and are well known in the art. Certain
fundamental types of succinimides and related materials encompassed by the
term of art "succinimide" are taught in U.S. Patent Nos. 2,992,708; 3,018,250;
3,018,291; 3,024,237; 3,100,673; 3,172,892; 3,219,666; 3,272,746;
3,361,673; 3,381,022; 3,912,764; 4,234,435; 4,612,132; 4,747,965;
5,112,507; 5,241,003; 5,266,186; 5,286,799; 5,319,030; 5,334,321;
5,356,552; 5,716,912.
The term "particulate emissions" refers to solid or liquid emissions which may
form either from incomplete oxidation of carbon in the combustion chamber, or
from precursors contained in the emission gases (either before or after
emission from the engine exhaust system). Of particular concern are particles
which are emitted in the size range below 100 nanometers.
The term "fuel" or "hydrocarbon-based fuel" refers to normally liquid
hydrocarbons having boiling points in the range of gasoline and diesel fuels.
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The Alkylene Oxide-Adducted Hydrocarbyl Amide
In its broadest aspect, the present invention employs a fuel composition
containing an alkylene oxide-adducted hydrocarbyl amide having from about
3 to 50 moles, preferably from about 3 to 20 moles, more preferably from
about 4 to 15 moles, of alkylene oxide per mole of hydrocarbyl amide. The
alkylene oxide-adducted hydrocarbyl amides will have the following structure:
/(R'- O)c,- (Ru- O)e- H
R-C-N
(RI- O)d- (Ru- O)r H
wherein,
R is a hydrocarbyl group having from about 4 to 75, preferably
from about 6 to 24, most preferably from about 6 to 20, carbon
atoms;
R' is a divalent alkylene group having from 1 to about 10,
preferably from about 2 to 5, more preferably from about 2 to 3,
carbon atoms;
R" is a divalent alkylene group having from about 2 to 5,
preferably from about 2 to 3, carbon atoms;
c and d are independently 0 or 1, preferably both are 1; and
e and f are independently integers from about 0 to 50, such that
the total of e plus f ranges from about 3 to 50.
Preferably, the hydrocarbyl group, R, is alkyl or alkenyl, more preferably,
alkyl.
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Preferably, e and f are independently integers from about 0 to 20, such that
the total of e plus f ranges from about 3 to 20. More preferably, e and f are
independently integers from about 0 to 15, and that the total of e plus f
ranges
from about 4 to 15.
The hydrocarbyl amide of the present invention is typically the reaction
product of a C4 to C75, preferably C6 to C24, more preferably C6 to C20, fatty
acid or ester, and ammonia, or a mono- or di-hydroxy hydrocarbon amine,
wherein the hydrocarbyl amide has the following structure:
0
!i
R N (R' OH)2-a (H)a
wherein R and R' are as defined above and a is an integer from
about 0 to 2. Preferably, a is 0.
The acid moiety may preferably be RCO- wherein R is preferably an alkyl or
alkenyl hydrocarbon group containing about 5 to 19 carbon atoms typified by
caprylic, caproic, capric, lauric, myristic, palmitic, stearic, oleic,
linoleic, etc.
Preferably the acid is saturated although unsaturated acid may be present.
Preferably, the reactant bearing the acid moiety may be natural oil: coconut,
babassu, palm kernel, palm, olive, castor, peanut, rape, beef tallow, lard,
lard
oil, whale blubber, sunflower, etc. Typically the oils which may be employed
will contain several acid moieties, the number and type varying with the
source of the oil.
The acid moiety may be supplied in a fully esterified compound or one which
is less than fully esterified, e.g., glyceryl tri-stearate, glyceryl di-
laurate,
glyceryl mono-oleate, etc. Esters of polyols, including diols and polyalkylene
glycols may be employed such as esters of mannitol, sorbitol, pentaerythritol,
polyoxyethylene polyol, etc.
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Ammonia or a mono- or di-(hydroxyhydrocarbon) amine with a primary or
secondary amine nitrogen may be reacted to form the hydrocarbyl amides of
the present invention. Typically, the mono- or di-(hydroxyhydrocarbon)
amines may be characterized by the formula:
HN(RyO1)2-bHb
wherein R' is as defined above and b is 0 or 1.
Typical amines may include, but are not limited to, ethanolamine,
diethanolamine, propanolamine, isopropanolamine, dipropanolamine, di-
isopropanola mine, butanolamines etc.
Reaction may be effected by heating the oil containing the acid moiety and
the amine in equivalent quantities to produce the desired product. Reaction
may typically be effected by maintaining the reactants at about 100 C. to 200
C., preferably about 120 C. to 150 C. for 1 to about 10 hours, preferably
about 4 hours. Reaction may be carried out in a solvent, preferably one
which is compatible with the ultimate composition in which the product is to
be
used.
Typical reaction products which may be employed in the practice of this
invention may include those formed from esters having the following acid
moieties and alkanolamines:
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TABLE 1
Acid Moiety in Ester Amine
Lauric Acid propanolamine
Lauric Acid diethanolamine
Lauric Acid ethanolamine
Lauric Acid dipropanolamine
Palmitic Acid diethanolamine
Palmitic Acid ethanolamine
Stearic Acid diethanolamine
Stearic Acid ethanolamine
Other useful mixed reaction products with alkanolamines may be formed from
the acid component of the following oils: coconut, babassu, palm kernel,
palm, olive, castor, peanut, rape, beef tallow, lard, whale blubber, corn,
tall,
cottonseed, etc.
In one preferred aspect of this invention, the desired reaction product may be
prepared by the reaction of (1) a fatty acid ester of a polyhydroxy compound
(wherein some or all of the OH groups are esterified) and (ii) diethanolamine.
Typical fatty acid esters may include esters of the fatty acids containing
about
6 to 20, preferably about 8 to 16, more preferably about 12, carbon atoms.
These acids may be characterized by the formula RCOOH wherein R is an
alkyl hydrocarbon group containing about 7 to 15, preferably about 1.1 to 13,
more preferably about 11 carbon atoms.
Typical of the fatty acid esters which may be employed may be glyceryl tri-
laurate, glyceryl tri-stearate, glyceryl tri-palmitate, glyceryl di-laurate,
glyceryl
mono-stearate, ethylene glycol di-laurate, pentaerythritol tetra-stearate,
pentaerythritol tri-laurate, sorbitol mono-palmitate, sorbitol penta-stearate,
propylene glycol mono-stearate.
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The esters may include those wherein the acid moiety is a mixture as is
typified by the following natural oils: coconut, babassu, palm kernel, palm,
olive, caster, peanut, rape, beef tallow, lard (leaf), lard oil, whale
blubber.
The preferred ester is coconut oil which contains the following acid moieties:
TABLE 2
Fatty Acid Moiety Wt. %
Caprylic 8.0
Capric 7.0
Lauric 48.0
Myristic 17.5
Palmitic 8.2
Stearic 2.0
Oleic 6.0
Linoleic 2.5
Examples of desirable alkyl amides suitable for the present invention include,
but are not limited to, octyl amide (capryl amide), nonyl amide, decyl amide
(caprin amide), undecyl amide dodecyl amide (lauryl amide), tridecyl amide,
teradecyl amide (myristyl amide), pentadecyl amide, hexadecyl amide
(palmityl amide), heptadecyl amide, octadecyl amide (stearyl amide),
nonadecyl amide, eicosyl amide (alkyl amide), or docosyl amide (behenyl
amide). Examples of desirable alkenyl amides include, but are not limited to,
palmitoolein amide, oleyl amide, isooleyl amide, elaidyl amide, linolyl amide,
linoleyl amide. Preferably, the alkyl or alkenyl amide is a coconut oil fatty
acid
amide.
The preparation of hydrocarbyl amides from fatty acid esters and
alkanolamines is described, for example, in U.S. Patent No. 4,729,769 to
Schlicht et al.
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The alkylene oxide which is adducted to the hydrocarbyl amide is derived
from an alkylene group having from about 2 to 5 carbon atoms. Preferably,
the alkylene oxide is selected from the group consisting of ethylene oxide,
propylene oxide, butylene oxide, and pentylene oxide. Ethylene oxide and
propylene oxide are particularly preferred. In addition, mixtures of alkylene
oxides are desirable in which, for example, a mixture of ethylene oxide and
propylene oxide may be used to form the alkylene oxide-adducted
hydrocarbyl amide of the present invention. A respective molar ratio of from
about 1:5 to 5:1 may be used in the case of a mixture of ethylene oxide and
propylene oxide.
A desirable number of moles of the alkylene oxide to be adducted to the
hydrocarbyl amide will be in the range of from about 3 to 50 moles of alkylene
oxide per 1 mole of hydrocarbyl amide. More preferably, the range of from
about 3 to 20 moles is particularly desirable. Most preferably, the range of
from about 4 to 15 moles is most preferable as a molar range of the alkylene
oxide per mole of hydrocarbyl amide.
Preferably, the alkylene oxide-adducted hydrocarbyl amide is derived from an
alkylene oxide-adduction reaction involving a coconut oil fatty acid amide
with
ethylene oxide and propylene oxide. However, the alkylene oxide adducted
2Q hydrocarbyl amides useful as fuel additives in the present invention can be
also a mixed product wherein various types and different moles of aikylene
oxide and can be adducted to various types of hydrocarbyl amides.
The amount of alkylene oxide-adducted hydrocarbyl amide added in a
hydrocarbon-based fuel will typically be in a range of from about 10 to 10,000
ppm by weight per weight (active component ratio). Preferably, the desired
range is from about 10 to 5,000 ppm by weight, more preferably a range of
from about 10 to 1,000 ppm by weight and most preferably a range from
about 50 to 500 ppm by weight, based on the total weight of the fuel
composition.
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Other Additives
The fuel composition employed in the- method of the present invention may
also contain at least one nitrogen-containing detergent additive. Suitable
detergent additives for use in this invention include, for example, aliphatic
hydrocarbyl amines, hydrocarbyl-substituted poly(oxyalkylene) amines,
hydrocarbyl-substituted succinimides, Mannich reaction products, nitro and
amino aromatic esters of polyalkylphenoxyalkanols, polyalkyiphenoxy-
aminoalkanes, polyalkylpyrrolidines, and mixtures thereof.
The aliphatic hydrocarbyl-substituted amines which may be employed in the
present invention are typically straight or branched chain hydrocarbyl-
substituted amines having at least one basic nitrogen atom and wherein the
hydrocarbyl group has a number average molecular weight of about 700 to
3,000. Preferred aliphatic hydrocarbyl-substituted amines include
polyisobutenyl and polyisobutyl monoamines and polyamines.
The aliphatic hydrocarbyl amines employed in this invention are prepared by
conventional procedures known in the art. Such aliphatic hydrocarbyl amines
and their preparations are described in detail in U.S. Patent Nos. 3,438,757;
3,565,804; 3,574,576; 3,848,056; 3,960,515; 4,832,702; and 6,203,584.
Another class of detergent additives suitable for use in the present invention
are the hydrocarbyl-substituted poly(oxyalkylene) amines, also referred to as
polyether amines. Typical hydrocarbyl-substituted poly(oxyalkylene) amines
include hydrocarbyl poly(oxyalkylene) monoamines and polyamines wherein
the hydrocarbyl group contains from 1 to about 30 carbon atoms, the number
of oxyalkylene units will range from about 5 to 100, and the amine moiety is
derived from ammonia, a primary alkyl or secondary dialkyl monoamine, or a
polyamine having a terminal amino nitrogen atom. Preferably, the
oxyalkylene moiety will be oxypropylene or oxybutylene or a mixture thereof.
Such hydrocarbyl-substituted poly(oxyalkylene) amines are described, for
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example, in U.S. Patent No. 6,217,624 to Morris et al., and U.S. Patent
No. 5,112,364 to Rath et al.
A preferred type of hydrocarbyl-substituted poly(oxyalkylene) monoamine is
an alkylphenyl poly(oxyalkylene)monoamine wherein the poly(oxyalkylene)
moiety contains oxypropylene units or oxybutylene units or mixtures of
oxypropylene and oxybutylene units. Preferably, the alkyl group on the
alkylphenyl moiety is a straight or branched-chain alkyl of 1 to about 24
carbon atoms. An especially preferred alkylphenyl moiety is
tetra propenylphenyl, that is, where the alkyl group is a branched-chain alkyl
of
about 12 carbon atoms derived from propylene tetramer.
An additional type of hydrocarbyl-substituted poly(oxyalkylene)amine finding
use in the present invention are hydrocarbyl-substituted poly(oxyalkylene)
aminocarbamates disclosed for example, in U.S. Patent Nos. 4,288,612;
4,236,020; 4,160,648; 4,191,537; 4,270,930; 4,233,168; 4,197,409;
4,243,798 and 4,881,945.
These hydrocarbyl poly(oxyalkylene)aminocarbamates contain at least one
basic nitrogen atom and have an average molecular weight of about 500 to
10,000, preferably about 500 to 5,000, and more preferably about 1,000 to
3,000. A preferred aminocarbamate is alkylphenyl poly(oxybutylene)
aminocarbamate wherein the amine moiety is derived from ethylene diamine
or diethylene triamine.
A further class of detergent additives suitable for use in the present
invention
are the hydrocarbyl-substituted succinimides. Typical hydrocarbyl-substituted
succinimides include polyalkyl and polyalkenyl succinimides wherein the
polyalkyl or polyalkenyl group has an average molecular weight of about 500
to 5,000, and preferably about 700 to 3,000. The hydrocarbyl-substituted
succinimides are typically prepared by reacting a hydrocarbyl-substituted
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succinic anhydride with an amine or polyamine having at least one reactive
hydrogen bonded to an amine nitrogen atom. Preferred hydrocarbyl-
substituted succinimides include polyisobutenyl and polyisobutanyl
succinimides, and derivatives thereof.
The hydrocarbyl-substituted succinimides finding use in the present invention
are described, for example, in U.S. Patent Nos. 5,393,309; 5,588,973;
5,620,486; 5,916,825; 5,954,843; 5,993,497; and 6,114,542, and British
Patent No. 1,486,144.
Yet another class of detergent additives which may be employed in the
present invention is Mannich reaction products which are typically obtained
from the Mannich condensation of a high molecular weight alkyl-substituted
hydroxyaromatic compound, an amine containing at least one reactive
hydrogen, and an aldehyde. The high molecular weight alkyl-substituted
hydroxyaromatic compounds are preferably polyalkylphenols, such as
polypropylphenol and polybutylphenol, especially polyisobutylphenol, wherein
the polyakyl group has an average molecular weight of about 600 to 3,000.
The amine reactant is typically a polyamine, such as alkylene polyamines,
especially ethylene or polyethylene polyamines, for example, ethylene
diamine, diethylene triamine, triethylene tetramine, and the like. The
aldehyde reactant is generally an aliphatic aldehyde, such as formaldehyde,
including paraformaldehyde and formalin, and acetaldehyde. A preferred
Mannich reaction product is obtained by condensing a polyisobutylphenol with
formaldehyde and diethylene triamine, wherein the polyisobutyl group has an
average molecular weight of about 1,000.
The Mannich reaction products suitable for use in the present invention are
described, for example, in U.S. Patent Nos. 4,231,759 and 5,697,988
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A still further class of detergent additive suitable for use in the present
invention are polyalkylphenoxyaminoalkanes. Preferred
polyalkylphenoxyaminoalkanes include those having the formula:
R6 R7 (III)
I
R5 0- O-CH - CH -A
wherein:
R5 is a polyalkyl group having an average molecular weight in the
range of about 600 to 5,000;
R6 and R7 are independently hydrogen or lower alkyl having 1 to about
6 carbon atoms; and
A is amino, N-alkyl amino having 1 to about 20 carbon atoms in the
alkyl group, N,N-dialkyl amino having 1 to about 20 carbon atoms in
each alkyl group, or a polyamine moiety having about 2 to 12 amine
nitrogen atoms and about 2 to 40 carbon atoms.
The polyalkylphenoxyaminoalkanes of Formula III above and their
preparations are described in detail in U.S. Patent No. 5,669,939.
Mixtures of polyalkylphenoxyaminoalkanes and poly(oxyalkylene) amines are
also suitable for use in the present invention. These mixtures are described
in detail in U.S. Patent No. 5,851,242.
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A preferred class of detergent additive finding use in the present invention
are
nitro and amino aromatic esters of polyalkylphenoxyalkanols. Preferred nitro
and amino aromatic esters of polyalkylphenoxyalkanols include those having
the formula:
R$ 0 )
R13 R11 (IV4 )
R9 C p CH CH-O R12
wherein:
R8 is nitro or -(CH2)n-NR13R14, wherein R13 and R14 are independently
hydrogen or lower alkyl having 1 to about 6 carbon atoms and n is 0 or
1;
R9 is hydrogen, hydroxy, nitro or -NR15R16, wherein R15 and R16 are
independently hydrogen or lower alkyl having 1 to about 6 carbon
atoms;
R10 and R11 are independently hydrogen or lower alkyl having 1 to
about 6 carbon atoms; and
R12 is a polyalkyl group having an average molecular weight in the
range of about 450 to 5,000.
The aromatic esters of polyalkylphenoxyalkanols shown in Formula IV above
and their preparations are described in detail in U.S. Patent No. 5,618,320.
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Mixtures of nitro and amino aromatic esters of polyalkylphenoxyalkanols and
hydrocarbyl-substituted poly(oxyalkylene) amines are also preferably
contemplated for use in the present invention. These mixtures are described
in detail in U.S. Patent No. 5,749,929.
Preferred hydrocarbyl-substituted poly(oxyalkylene) amines which may be
employed as detergent additives in the present invention include those having
the formula:
R18 R19 (V)
R17 CH-CH B
m
wherein:
R17 is a hydrocarbyl group having from 1 to about 30 carbon atoms;
R15 and R19 are each independently hydrogen or lower alkyl having
about 1 to about 6 carbon atoms and each R18 and R19 is
independently selected in each -O-CHR18-CHR19- unit;
B is amino, N-alkyl amino having 1 to about 20 carbon atoms in the
alkyl group, N,N-dialkyl amino having 1 to about 20 carbon atoms in
each alkyl group, or a polyamine moiety having about 2 to 12 amine
nitrogen atoms and about 2 to 40 carbon atoms; and
m is an integer from about 5 to 100.
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The hydrocarbyl-substituted poly(oxyalkylene) amines of Formula V above
and their preparations are described in detail in U.S. Patent No. 6,217,624.
The hydrocarbyl-substituted poly(oxyalkylene) amines of Formula V are
preferably utilized either by themselves or in combination with other
detergent
additives, particularly with the polyalkyiphenoxyaminoalkanes of Formula III
or
the nitro and amino aromatic esters of polyalkylphenoxyalkanols. shown in
Formula IV. More preferably, the detergent additives employed in the present
invention will be combinations of the hydrocarbyl-substituted
poly(oxyalkylene) amines of Formula V with the nitro and amino aromatic
esters of polyalkylphenoxyalkanols shown in Formula IV. A particularly
preferred hydrocarbyl-substituted poly(oxyalkylene) amine detergent additive
is dodecylphenoxy poly(oxybutylene) amine and a particularly preferred
combination of detergent additives is the combination of dodecylphenoxy
poly(oxybutylene) amine and 4-polyisobutylphenoxyethyl
para-aminobenzoate.
Another type of detergent additive suitable for use in the present invention
are
the nitrogen-containing carburetor/injector detergents. The
carburetor/injector
detergent additives are typically relatively low molecular weight compounds
having a number average molecular weight of about 100 to 600 and
possessing at least one polar moiety and at least one non-polar moiety. The
non-polar moiety is typically a linear or branched-chain alkyl or alkenyl
group
having about 6 to 40 carbon atoms. The polar moiety is typically nitrogen-
containing. Typical nitrogen-containing polar moieties include amines (for
example, as described in U.S. Patent No. 5,139,534 and PCT International
Publication No. WO 90/10051), ether amines (for example, as described in
U.S. Patent No. 3,849,083 and PCT International Publication
No. WO 90/10051), amides, polyamides and amide-esters (for example, as
described in U.S. Patent Nos. 2,622,018; 4,729,769; and 5,139,534; and
European Patent Publication No. 149,486), imidazolines (for example, as
described in U.S. Patent No. 4,518,782), amine oxides (for example, as
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described in U.S. Patent Nos. 4,810,263 and 4,836,829), hydroxyamines (for
example, as described in U.S. Patent No. 4,409,000), and succinimides (for
example, as described in U.S. Patent No. 4,292,046).
Still other detergent additives useful in the present invention are
polyalkylpyrrolidines, as described in U.S. Patent No. 6,033,446 having
the following formula:
Rj
N- (R2- NH)X R3 (1)
or a fuel-soluble salt thereof;
wherein
R, is a polyalkyl group having an average molecular weight in the
range of from about 500 to 5,000;
R2 is a straight- or branched-chain alkylene group having from about 2
to 6 carbon atoms;
R3 is H or CH3; and
x is an integer from 0 to about 4.
Preferably, R, is a polyalkyl group having an average molecular weight in the
range of from about 500 to 3,000, more preferably from about 700 to 2,000,
and most preferably from about 700 to 1,500.
In addition, R1 is preferably a polyalkyl group derived from polypropylene,
polybutene, or polyalphaolefin oligomers of 1-octene or 1-decene. More
preferably, R1 is a polyalkyl group derived from polyisobutene. Most
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preferably, R, is a polyaikyl group derived from a highly reactive
polyisobutene containing at least about 20% of a methylvinylidene isomer.
Preferably, R2 is a straight- or branched-chain alkylene group having from
about 2 to 4 carbon atoms. Most preferably, R2 contains about 2 or 3 carbon
atoms.
Preferably, R3 is H.
Preferably, x is an integer of from 0 to about 2. Most preferably, x is 0.
The fuel additive composition of the present invention can also be combined
with one, two, or more other additives publicly known to be used in
hydrocarbon-based fuels. Such additives include, but are not limited to,
deposit control additives such as detergents or dispersants, corrosion
inhibitors, oxidation inhibitors, metal deactivators, demulsifiers, static
electricity preventing agents, anti-coagulation agents, anti-knock agents,
oxygenates, flow improvers, pour point depressants, cetane improvers and
auxiliary-solution agents.
Diesel fuels will typically contain various additives in conventional amounts.
The additives include cold flow improvers, pour point depressants, storage
stabilizers, corrosion inhibitors, anti-static agents, biocidal additives,
combustion modifiers or smoke suppressants, dyes, and deodorants.
Examples of such additives are known to the art as well as to the literature.
Accordingly, only a few additives will be discussed in detail. Considering the
storage stabilizers, they can include various antioxidants which prevent the
accumulation of organic peroxides such as hindered phenols, N,N,-dialkyl
paraphenylene diamines, paraamino phenols and the like. Color stabilizers
constitute another group with specific examples including tertiary amines,
secondary amines, imidazolines, tertiary alkyl primary amines, and the like.
Another storage stabilizer group are the various metal deactivators for metals
which serve as catalysts for oxidation during storage. Yet other storage
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stabilizers are the various dispersants which keep gummy, insoluble residues
and other solids dispersed as small particles so that they do not interfere
with
the proper burning of the fuel. Such compounds can be oil soluble
ethoxylated alkyl phenols, polyisobutylene alkylated succinimides, polyglycol
esters of alkylated succinic anhydrides, and the like.
Considering the corrosion inhibitors which generally retard the effects of
oxygen and/or water, they are generally polar organic molecules which form a
monomolecular protective layer over metal surfaces. Chemically, such
corrosion inhibitors fall into three general classes: (1) complex carboxylic
acids or their salts, (2) organic phosphorus acids and their salts, and (3)
ammonium mahogany sulfonates.
Combustion modifiers for diesel fuel have been found to suppress the
formation of black smoke, that is, unburned carbon particles, in the diesel
engine. These additives are believed to not only catalyze the burning of
carbon particles to C02, but also to suppress the formation of free carbon in
the early stages of the combustion cycle. Generally, two different types of
chemicals are effective in suppressing diesel smoke. The first type comprises
barium and calcium salts in amine or sulfonate complexes while the other
type consists of metal alkyls of transition elements such as manganese, iron,
cobalt, nickel, and the like.
Amounts of the various fuel additives in the fuel can vary over a considerable
range. Generally, a suitable amount of a diesel fuel stabilizer is from about
3
to about 300 ppm. A suitable amount of a corrosion inhibitor is from about 1
to about 100 ppm with a suitable amount of a smoke suppressant being from
about 100 to about 5,000 ppm. Naturally, higher or lower amounts can be
utilized depending upon the type of fuel, the type of diesel engine, and the
like.
Diesel fuels may also contain various sulfur-free and sulfur-containing cetane
improvers. Desirably, the sulfur-free compounds are nitrate cetane improvers
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which are known to the art as well as to the literature. For example, a
description of such nitrate cetane improvers are set forth in U.S. Patent Nos.
2,493,284; 4,398,505; 2,226,298; 2,877,749; 3,380,815; an article "Means of
Improving Ignition Quality of Diesel Fuels" by Nygarrd et al, J. Inst.
Petroleum,
27, 348-368 (1941); an article "Preflame Reactions in Diesel Engines", Part 1,
by Gardner et al, The Institute of Petroleum, Vol. 38, 341, May, 1952;.and an
article "Ignition Accelerators for Compression-Ignition Fuels" by Bogen et al,
Petroleum Refiner 23, (7) 118-52 (1944), with regard to various types of
nitrate cetane improvers. Generally, the cetane improvers are alkyl nitrates
having from about 1 to about 18 carbon atoms and desirably from about 2 to
about 13 carbon atoms. Examples of specific nitrate cetane improvers
include ethyl nitrate, butyl nitrate, amyl nitrate, 2-ethylhexyl nitrate,
polyglycol
dinitrate, and the like. Amyl nitrate and 2-ethylhexyl nitrate are preferred.
Sulfur-containing cetane improvers are described, for example, in U.S. Patent
No. 4,943,303. Combinations of sulfur-containing cetane improvers with
sulfur-free cetane improvers, such as nitrate cetane improvers, may also be
employed in diesel fuels.
A fuel-soluble, nonvolatile carrier fluid or oil may also be used with the
alkylene oxide-adducted hydrocarbyl amides employed in the present
invention. The carrier fluid is a chemically inert hydrocarbon-soluble liquid
vehicle which. substantially increases the nonvolatile residue (NVR), or
solvent-free liquid fraction of the fuel composition while not overwhelmingly
contributing to octane requirement increase. The carrier fluid may be a
natural or synthetic oil, such as mineral oil, refined petroleum oils,
synthetic
polyalkanes and alkenes, including hydrogenated and unhydrogenated
polyalphaolefins, synthetic polyoxyalkylene-derived oils, such as those
described, for example, in U.S. Pat. No. 4,191,537 to Lewis, and polyesters,
such as those described, for example, in U.S. Pat. Nos. 3,756,793 and
5,004,478 to Robinson and Vogel et al., respectively, and in European Pat.
Application Nos. 356,726 and 382,159, published Mar. 7, 1990 and Aug. 16,
1990, respectively.
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EXAMPLES.
The invention will be further illustrated by following examples, which set
forth
particularly advantageous method embodiments. While the Examples are
provided to illustrate the present invention, they are not intended to limit
it.
Example I
A method for measuring reduction in particulate emissions from an internal
combustion engine using the current method for reduction of particulate
emissions is described below. This example was performed using a 1998
Mitsubishi Carisma equipped with a 1.8 Liter gasoline direct injection spark
ignition engine. However, this is not limiting and such procedures could be
modified by those with skill in the art to cover other engine types.
In order to simulate on-road operating conditions, the test vehicle is placed
on
a mileage accumulation chassis dynamometer. This dynamometer can be
used to load the vehicle (according to a vehicle-specific road-load model)
corresponding to cruising conditions at any desired speed.
In order to start the test, the vehicle fuel system is first drained, flushed
of any
residual fuel, then re-filled with the test fuel. At this point, the engine is
started and the vehicle is operated at a speed of 50 kilometers per hour for
90
minutes to ensure that the engine and drivetrain are at full operating
temperature.
Following this warm-up phase, the vehicle speed is brought to the first
operating condition (see Table 3). The vehicle is allowed to operate at this
condition for 15 minutes prior to the start of data collection. After the
completion of data collection for the first condition, the vehicle is moved to
each of the three remaining operating conditions sequentially, with data
collection following the same 15 minute stabilization period. At the
conclusion
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CA 02440548 2003-09-11
of data collection for the final operating condition, the vehicle is run for
30
minutes at a speed of 50 kilometers per hour, then is shut down.
TABLE 3
Engine Test Operating Conditions
Operating condition # Vehicle Speed Throttle position
(% open)
1 40 km/h 3.7
2 60 km/h 4.9
3 80 km/h 6.5
4 100 km/h 13.9
To ensure that the vehicle is running properly, a number of critical engine
temperatures and pressures (e.g. engine oil temperature and pressure,
coolant temperature) are monitored throughout the test.
In order to measure particulate emissions, a portion of the engine exhaust
gas is continuously extracted from the vehicle exhaust system (upstream of
the catalytic converter) and is diluted with clean, filtered air to a ratio of
approximately 500:1 in a standard free jet dilution tunnel. A scanning
mobility
particle sizer (SMPS) is then used to measure the number-weighted particle
size distribution in the size range from 5 to 80 nanometers. For each test
operating condition, a total of ten size distribution measurements are
collected; the total particle number concentration in this size range is then
reported as an average of the ten measurements.
In order to evaluate reduction in particulate emissions, tests were conducted
using two fuels. Fuel "A" was a typical, commercially available California
reformulated base gasoline which contained no additives. Fuel "B" was the
same base gasoline as fuel "A", with the addition of a coconut oil fatty acid
diethanol amide adducted with 4 moles of propylene oxide at a concentration
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CA 02440548 2003-09-11
of 130 ppm. Each fuel was tested twice, in the following order: A - B - B - A.
The results are shown in Table 4.
The results in Table 4 show a substantial reduction in the number of particles
emitted by the engine in the size range from 5 to 80, nanometers when
carrying out the method of the present invention.
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CA 02440548 2003-09-11
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