Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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EL-6264
ENVIRONMENTALLY-FRIENDLY FUEL COMPOSITIONS AND
ADDITIVES THEREFOR
This invention relates to middle distillate fuel
compositions such as diesel fuel, home heating oil,
kerosene, jet fuel, aviation fuel, gas turbine engine
fuels, light cycle oils, etc. having improved combustion
characteristics.
It has long been known to use small quantities of
various additives to improve the properties and/or perfor-
mance characteristics of middle distillate fuels. For
example, small quantities of dispersants have been used in
order to improve engine or burner cleanliness and thereby
obtain in time a reduction in the amount of noxious emis-
sions formed on combustion of the fuel. Likewise, anti-
oxidants, corrosion inhibitors, antifoam agents, demulsi-
fiers and similar types of additives have been employed in
such fuels.
This invention involves the surprising discovery
that it is possible to provide a middle distillate fuel
composition which results on combustion in almost imme-
diate substantial reductions of noxious emissions such as,
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unburned hydrocarbons, particulates, and/or carbon monox-
ide. Moreover, it has been found that such fuel composi-
tions can provide substantial improvements in fuel economy
in the operation, for example, of diesel engines.
In the practise of this invention use is made of a
higher concentration of fuel-soluble ashless dispersant
than was customarily employed in fuels heretofore. In
addition, the fuel compositions preferably contain one or
more sterically hindered phenolic compounds, most prefer-
ably a 2,6-dihydrocarbyl-a-dihydrocarbylamino-p- cresol
such as 2,6-di-tert-butyl-a-dimethylamino-p-cresol which
is available from Ethyl Corporation as ETHYL~ antioxidant
703.
Accordingly, in one of its embodiments this inven-
tion provides a fuel composition which comprises liquidmiddle distillate hydrocarbonaceous fuel containing at
least one fuel-soluble ashless dispersant in an amount of
at least 50 ppm sufficient to cause a prompt reduction in
emissions released upon combustion of said fuel composi-
tion. Preferably the fuel contains 75 to 1,000 ppm andmost preferably 100-250 ppm of the ashless dispersant.
Another embodiment of this invention is a method of
achieving an almost immediate reduction in the amount of
noxious emissions formed on combustion of a hydrocarbon-
aceous fuel in the middle distillate boiling range whichcomprises blending in such fuel an ashless dispersant in
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an amount of at least 50 ppm sufficient to achieve such
reduction in emissions.
Other embodiments of this invention will be appa-
rent from the ensuing description and appended claims.
Ashless Dispersants. Ashless dispersants are
described in numerous patent specifications, mainly as
additives for use in lubricant compositions, but their use
in hydrocarbon fuels has also been described. Ashless dis-
persants leave little or no metal-containing residue on
combustion. They generally contain only carbon, hydrogen,
oxygen and in most cases nitrogen, but sometimes contain
in addition other non-metallic elements such as phosphor-
us, sulphur or boron.
The preferred ashless dispersant is an alkenyl suc-
cinimide of an amine having at least one primary aminogroup capable of forming an imide group. Representative
examples are given in U.S. Pat. Nos. 3,172,892; 3,202,678;
3,216,936; 3,219,666; 3,254,025; 3,272,746; and
4,234,435. The alkenyl succinimides may be formed by
conventional methods such as by heating an alkenyl suc-
cinic anhydride, acid, acid-ester, acid halide, or lower
alkyl ester with an amine containing at least one primary
amino group. The alkenyl succinic anhydride may be made
readily by heating a mixture of olefin and maleic anhy-
dride to about 180-220-C. The olefin is preferably a
_ 4 _ 20~382~
polymer or copolymer of a lower monoolefin such as ethyl-
ene, propylene, isobutene and the like. The more pre-
ferred source of alkenyl group is from polyisobutene
having a molecular weight up to 10,000 or higher. In a
still more preferred embodiment the alkenyl group is a
polyisobutenyl group having a molecular weight of about
500-5,000, and preferably about 700-2,000, especially
800-1,200. The isobutene used in making the polyisobutene
is usually (but not necessarily) a mixture of isobutene
and other C4 isomers such as l-butene. Thus, strictly
speaking, the acylating agent formed from maleic anhydride
and "polyisobutene" made from such mixtures of isobutene
and other C4 isomers such as l-butene, can be termed a
"polybutenyl succinic anhydride" and a succinimide made
therewith can be termed a "polybutenyl succinimide". How-
ever, it is common to refer to such substances as "poly-
isobutenyl succinic anhydride" and "polyisobutenyl succin-
imide", respectively. As used herein "polyisobutenyl" and
"polybutenyl" are used interchangably to denote the al-
kenyl moiety whether made from a highly pure isobutene ora more impure mixture of isobutene and other C4 isomers
such as l-butene.
Amines which may be employed in forming the ashless
dispersant include any that have at least one primary
amino group which can react to form an imide group. A few
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representative examples are: ~ethylamine, 2-ethylhexyl-
amine, n-dodecylamine, stearylamine, N,N-dimethylpropane-
diamine, N-(3-aminopropyl)morpholine, N-dodecylpropanedi-
amine, N-aminopropyl-piperazine, ethanolamine, N-ethanol-
ethylenediamine and the like.
The preferred amines are the alkylene polyaminessuch as propylene diamine, dipropylene triamine, di-(1,2-
butylene)triamine, and tetra-(1,2-propylene)pentamine.
The most preferred amines are the ethylene poly-
amines which can be depicted by the formula
H2N (CH2CH2NH) nH
wherein n is an integer from one to about ten. These
include: ethylene diamine, diethylene triamine, tri-
ethylene tetramine, tetraethylene pentamine, pentaethylene
hexamine, and the like, including mixtures thereof in
which case n is the average value of the mixture. These
ethylene polyamines have a primary amine group at each end
so can form mono-alkenylsuccinimides and bis-alkenylsuc-
cinimides. Commercially available ethylene polyamine mix-
tures usually contain minor amounts of branched speciesand cyclic species such as N-aminoethyl piperazine, N,N'-
bis(aminoethyl)piperazine, N,N'-bis- (piperazinyl)ethane,
and like compounds. The preferred commercial mixtures
have approximate overall compositions falling in the range
corresponding to diethylene triamine to pentaethylene hexa-
mine, mixtures generally corresponding in overall makeup
205382~ '
to tetraethylene pentamine being most preferred.
Thus especially preferred ashless dispersants for
use in the present invention are the products of reaction
of a polyethylene polyamine, e.g. triethylene tetramine or
tetraethylene pentamine, with a hydrocarbon-substituted
carboxylic acid or anhydride made by reaction of a poly-
olefin, preferably polyisobutene, having a number average
molecular weight of 500 to 5,000, preferably 700 to 2,000
and especially 800 to 1,200, with an unsaturated polycar-
boxylic acid or anhydride, e.g., maleic anhydride, maleic
acid, fumaric acid, or the like, including mixtures of two
or more such substances.
As used herein the term "succinimide" is meant to
encompass the completed reaction product from reaction
between components (i) and (ii) and is intended to encom-
pass compounds ~herein the product may have amide, ami-
dine, and/or salt linkages in addition to the imide link-
age of the type that results from the reaction of a pri-
mary amino group and an anhydride moiety.
Another class of useful ashless dispersants
includes alkenyl succinic acid esters and diesters of
alcohols containing 1-20 carbon atoms and 1-6 hydroxyl
groups. Representative examples are described in U.S.
Pat. Nos. 3,331,776; 3,381,022; and 3,522,179. The
alkenyl succinic portion of these esters corresponds to
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the alkenyl succinic portion of the succinimides described
above including the same preferred and most preferred sub-
genus, e.g., polyisobutenyl succinic acids wherein the
polyisobutenyl group has a number average molecular weight
of 500 to 5,000, preferably 700-2,000, especially 800 to
1,200.
Alcohols useful in preparing the esters include
methanol, ethanol, isobutanol, octadecanol, eicosanol,
ethylene glycol, diethylene glycol, tetraethylene glycol,
diethylene glycol monoethylether, propylene glycol, tri-
propylene glycol, glycerol, sorbitol, 1,1,1-trimethylol
ethane, 1,1,1-trimethylol propane, l,l,1-trimethylol
butane, pentaerythritol, dipentaerythritol, and the like.
The succinic esters are readily made by merely heat-
in~ a mixture of alkenyl succinic acid, anhydrides or low-
er alkyl (e.g., C1-C4) ester with the alcohol while
distilling out water or lower alkanol. In the case of
acid-esters less alcohol is used. In fact, acid-esters
made from alkenyl succinic anhydrides do not evolve
water. In another method the alkenyl succinic acid or
anhydrides can be merely reacted with an appropriate
alkylene oxide such as ethylene oxide, propylene oxide,
and the like, including mixtures thereof.
In another embodiment the ashless dispersant is an
alkenyl succinic ester-amide mixture. These may be made
(- ~0~3825
by heating the above-described alkenyl succinic acids,
anhydrides or lower alkyl esters with an alcohol and an
amine either sequentially or in a mixture. The alcohols
and amines described above are also useful in this embod-
iment. Alternatively, amino alcohols can be used alone orwith the alcohol and/or amine to form the ester-amide
mixtures. The amino alcohol can contain 1-20 carbon
atoms, 1-6 hydroxy groups and 1-4 amine nitrogen atoms.
Examples are ethanolamine, diethanolamine, N-ethanol-di-
ethylene triamine, and trimethylol aminomethane.
Representative examples of suitable ester-amide
mixtures are described in U.S. Pat. Nos. 3,184,474;
3,576,743; 3,632,511; 3,804,763; 3,836,471; 3,862,981;
3,936,480; 3,948,800; 3,950,341; 3,957,854; 3,957,8S5;
3,991,098; 4,071,548; and 4,173,540.
Such ashless dispersants containing alkenyl
succinic residues may, and as is well known, be post-
reacted with boron compounds, phosphorus derivatives
and/or carboxylic acid acylating agents, e.g. maleic
anhydride-
Another useful class of ashless dispersantsincludes the Mannich condensates of hydrocarbyl- substi-
tuted phenols, formaldehyde or formaldehyde precursors
(e.g. paraformaldehyde) and an amine having at least one
primary amine group and containing 1-10 amine gr~ups and
1-20 car~on atoms. Mannich condensates useful in this
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invention are described in U.S. Pat. Nos. 3,442,808;
3,448,047; 3,539,633; 3,591,598; 3,600,372; 3,634,515;
3,697,574; 3,703,536; 3,704,308; 3,725,480; 3,726,882;
3,736,357; 3,751,365; 3,756,953; 3,793,202; 3,798,165;
3,798,247; 3,803,039: and 3,413,347.
More preferred Mannich condensates are those made
by condensing a polyisobutenyl phenol wherein the poly-
isobutenyl group has an average molecular weight of about
800-3,000 with formaldehyde or a formaldehyde precursor
and an ethylene polyamine having the formula:
H2N (CH2CH2NH) nH
wherein n is an integer from one to ten or mixtures there-
of especially those in which n has an avera~e value of
3-5.
Typical post-treated ashless dispersants such as
succinimides and Mannich condensates are described in U.S.
Pat. Nos. 3,036,003; 3,087,936; 3,200,107; 3,216,936;
3,254,025; 3,256,185; 3,278,550; 3,280,234; 3,281,428;
3,282,955; 3,312,619; 3,366,S69; 3,367,943; 3,373,111;
20 3,403,102; 3,442,808; 3,455,831; 3,455,832; 3,493,520;
3,502,677; 3,513,093; 3,533,945; 3,539,633; 3,573,010;
3,S79,450; 3,591,598; 3,600,372; 3,639,242; 3,649,229;
3,649,659; 3,658,846; 3,697,574; 3,702,575; 3,703,536;
3,704,308; 3,708,422; and 4,857,214.
A further type of ashless dispersants which can be
used comprises interpolymers of oil-solubilising monomers
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such as decyl methacrylate, vir.yl decyl ether and high
molecular weight olefins with monomers containing polar
substituents, e.g., aminoalkyl acrylates or acrylamides
and poly(oxyethylene)-substituted acrylates. These may be
characterised as "polymeric dispersants" and examples
thereof are disclosed in the following U.S. Pat. Nos.:
3,329,658; 3,449,250; 3,519,565; 565; 3,666,730;
3,687,849; and 3,702,300.
Another class of ashless dispersants which can
advantageously be used in the fuel compositions of this
invention are the imidazoline dispersants which can be
represented by the formula:
H2 lC -- IN - R2
H2C ~ ~C - R
N
wherein Rl represents a hydrocarbon group having 1 to 30
carbon atoms, e.g. an alkyl or alkenyl group having 7 to
22 carbon atoms, and R2 represents a hydrogen atoms or a
hydrocarbon radical of 1 to 22 carbon atoms, or an amino-
alkyl, acylaminoalkyl or hydroxyalkyl radical having 2 to
50 carbon atoms. Such long-chain alkyl (or long-chain
alkenyl) imidazoline compounds may be made by reaction of
a corresponding long-chain fatty acid (of formula R1-
COOH), for example oleic acid, with an appropriate poly-
amine. The imidazoline formed is then ordinarily called,
2053825 (~
for example, oleylimidazoline where the radical Rl repre-
sents the oleyl residue of oleic acid. Other suitable
alkyl substituents in the 2-position of these imidazolines
include undecyl, heptadecyl, lauryl and erucyl. Suitable
N-substituents of the imidazolines (i.e. radicals R2)
include hydrocarbyl groups, hydroxyalkyl groups, amino-
alkyl groups, and acylaminoalkyl groups. Examples of the
foregoing groups include methyl, butyl, decyl, cyclohexyl,
phenyl, benzyl, tolyl, hydroxyethyl, aminoethyl, oleyl-
aminoethyl and stearylaminoethyl.
Other suitable ashless dispersants which may be
incorporated in the fuel compositions of this invention
include the products of condensation of a cyclic anhydride
with a straight-chain N-al~ylpolyamine of the formula:
R-(NH-R'-) -NH2
where n is an integer at least equal to 1, usually 3 to 5,
R is a saturated or unsaturated linear hydrocarbon radical
of 10 to 22 carbon atoms and R' is a divalent alkylene or
alkylidene radical of 1 to 6 carbon atoms. Examples of
such polyamines include N-oleyl-1,3-propanediamine,
N-stearyl-1,3-propanediamine, N-oleyl-1,3-butanediamine,
N-oleyl-2-methyl-1,3-propanediamine, N-oleyl-1,3-pentane-
diamine, N-oleyl-2-ethyl-1,3-propanediamine, N-stearyl-
1,3-butanediamine, N-stearyl-2-methyl-1,3-propanediamine,
N-stearyl-1,3-pentanediamine, N-stearyl-2-ethyl-1,3-pro-
panediamine, N-oleyl-dipropylenetriamine and N-stearyl-
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dipropylenetriamine. Such linear N-alkylpolyamines are
condensed with, e.g., a succinic, maleic, phthalic or hexa-
hydrophthalic acid anhydride which may be substituted by
one or more radicals of up to 5 carbon atoms each.
Another class of ashless dispersant which can be
incorporated in the compositions of the present invention
are the products of reaction of an ethoxylated amine made
by reaction of ammonia with ethylene oxide with a carbox-
ylic acid of 8 to 30 carbon atoms. The ethoxylated amine
may be, for example, mono-, di- or tri-ethanolamine or a
polyethoxylated derivative thereof, and the carboxylic
acid may be, for example, a straight or branched chain
fatty acid of 10 to 22 carbon atoms, a naphthenic acid, a
resinic acid or an alkyl aryl carboxylic acid.
Still another type of ashless dispersants which can
be used in the practise of this invention are the ~-
olefin-maleimide copolymers such as are described in U.S.
Pat. No. 3,909,215. Such copolymers are alternating
copolymers of N-substituted maleimides and aliphatic
~-olefins of from 8 to 30 carbon atoms. The copolymers
may have an average of 4 to 20 maleimide groups per mole-
cule. The substituents on the nitrogen of the maleimide
may be the same or different and are organic radicals
composed essentially of carbon, hydrogen and nitrogen
having a total of 3 to 60 carbon atoms. A commercially
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available material which is hishly suitable for use in
this invention is Chevron OFA 425B, and this material is
believed to be or comprise an ~-olefin maleimide copolymer
of the type described in U.S. Pat. No. 3,909,215.
S All the aforesaid types of ashless dispersants are
described in the literature and many are available commer-
cially. Mixtures of various types of ashless dispersants
can, of course, be used.
Because of environmental concerns it is desirable
to employ ashless dispersants which contain little, if
any, halogen atoms such as chlorine atoms. Thus, in order
to satisfy such concerns, it is desirable (although not
necessary from a performance standpoint) to select ashless
dispersants ~as well as the other components used in the
compositions of this invention) such that the total halo-
gen content of the overall fuel composition does not
exceed 10 ppm. Indeed, the lower the better. Most
desirably, the additive composition contains no detectable
amount of halogen.
Typical halogen (chlorine)-free ashless dispersants
suitable for use in the compositions of this invention
include, in addition to various types described herein-
above, those described in the following recently-published
applications: WO 9003359 and EP 365288.
Hindered Phenolic Antioxidants. As noted above it
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is desirable to include in the fuel compositions at least
one fuel-soluble hindered phenolic antioxidant. One
preferred type of compound is comprised of compounds of
the formula
Rl
HO ~ CH2N
R4
R2
wherein R1 is a hydrocarbyl group containing 1 to 12
carbon atoms, R2 is a secondary or tertiary hydrocarbyl
group containing from 3 to 12 carbon atoms, R3 is a
hydrocarbyl group or a group of the formula
HO ~ CH2-
R2
and R4 is a hydrocarbyl group. R3 and R4, when
hydrocarbyl groups, can contain 50 or more carbon atoms
but usually contain 18 or less carbon atoms. Methods
applicable for the synthesis of such compounds are
described for example in U.S. Patent No. 2,962,531.
Another preferred type of phenolic antioxidant
r 2~382~ ~
for use in the practise of this invention is comprised of
methylene bridged phenolic compounds including 2,2'-meth-
ylenebis(4,6-dihydrocarbylphenols), 4,4'-methylenebis(2,6-
dihydrocarbylphenols), and various mixtures of methylene
bridged alkylphenols such as are described in U.S. Patent
No. 3,211,652. Typical 2,2'-methylenebis(4,6-dihydro-
carbylphenols) include 2,2'-methylenebis(4-methyl-6-tert-
butylphenol), 2,Z'-methylenebis(4-ethyl-6-tert-butyl-phe-
nol), 2,2'-methylenebis(4,6-di-tert-butylphenol), and the
like. Exemplary 4,4'-methylenebis(2,6-dihydrocarbyl-phe-
nols) include 4,4'-methylenebis(2,6-di-tert-butylphenol),
4,4'-methylenebis(2-methyl-6-tert-butylphenol), 4,4'-
methylenebis(2,6-diisopropyl-phenol), 4,4'-methylene-
bis(2-tert-amyl-o-cresol), and similar compounds. Synthe-
sis of such compounds are described for example in U.S.
Patent No. 2,807,653. Commercially available methylene-
bridged alkyl phenols include ETHYL~ antioxidant 728 and
ETHYL~ antioxidant 702, both available from Ethyl Corpora-
tion.
Other sterically hindered phenolic antioxidants
which can be used include 2,6-di-tert-butylphenol,
4-methyl-2,6-di-tert-butylphenol, 2,4,6-tri-tert-butyl-
phenol, 2-tert-butylphenol, 2,6-diisopropylphenol,
2-methyl-6-tert-butylphenol, 2,4-dimethyl-6-tert-butyl-
phenol, 4-ethyl-2,6-di-tert-butylphenol, 2-methyl-6-
styrylphenol, 2,6-di-styryl-4-nonylphenol, and their
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analogs and homologs. Mixtures of two or more such phe-
nolic compounds are also suitable such as for example,
ETHYL~ antioxidant 733 available from Ethyl Corporation.
In preferred embodiments of this invention one or
more additional components are included in the fuel com-
positions. These include demulsifying agents, metal
deactivators, antifoam agents, corrosion inhibitors,
lubricity additives, friction modifiers, and/or solvents.
Demulsifyinq Agents. The demulsifying agent
improves the water tolerance level of the fuel composi-
tions by minimizing or preventing excessive emulsion
formation.
Exemplary demulsifiers which may be employed in
the practise of this invention include poly(alkylphenol)
formaldehyde condensates and the polyalkylenoxy modified
reaction products thereof. These compounds are prepared
by reacting an alkylphenol with formaldehyde and there-
after reacting the reaction product of the above with a
C2 to C6 alkylene oxide such as ethylene oxide and
propylene oxide. The demulsifiers have a generalized
structural formula
O(UO)yH O(UO)yH
~ -CH2 ~ H
R5 _ R5 _ x
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- 17 -
wherein U is an alkylene of 2 to 6 carbons; y is an
integer averaging between 4 and 10; x is an integer
averaging between 4 and 10; and R5 is an alkyl having
from 4 to 15 carbon atoms.
S Preferred demulsifiers described by the above for-
mula are polyethyleneoxy modified methylene bridged poly-
(alkylphenol) polymers having a polyethyleneoxy chain of 8
to 20 carbons and preferably from 10 to 16 carbons and at
least about 75 number percent of the polyethyleneoxy
chains being within the range specified. The methylene
bridged poly(alkylphenol) portion of the polymer has from
4 to 10 and preferably from 5 to 8 repeating methylene
bridged alkylphenol units with 4 to 15 and preferably 6 to
12 carbons in the alkyl group. In preferred embodiments,
the alkyl groups are a mixture of alkyls having between 4
and 12 carbon atoms.
Illustrative alkylphenols include p-isobutylphenol,
p-diisobutylphenol, p-hexylphenol, p-heptylphenol, p-octyl-
phenol, p-tripropylenephenol, and p-dipropylenephenol,
etc.
Another type of demulsifier component is an
ammonia-neutralised sulphonated alkylphenol. These
compounds have the general structure:
R1 ~ 5O3NH4
H0
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- 18 -
wherein Rl is a hydrocarbyl grcup having from 4 to 15
carbon atoms, preferably from 6 to 12.
These compounds are prepared by sulphonating an
alkylated phenol and thereafter neutralising the sulpho-
nated product with ammonia.
Another type of demulsifier is an oxyalkylated gly-
col. These compounds are prepared by reacting a polyhy-
droxy alcohol such as ethylene glycol, trimethylene gly-
col, etc., with ethylene or propylene oxide. Many of the10 compounds are commercially available from BASF-Wyandotte
Chemical Company under the PLURONIC trademark. They are
polyethers terminated by hydroxy groups and produced by
the block copolymerisation of ethylene oxide and propylene
oxide. The ethylene oxide blocks act as the hydrophiles
and the propylene oxide blocks as the hydrophobes. They
are available in a wide range of molecular weights and
with varying ratios of ethylene oxide to propylene oxide.
A further type of commercially available demulsi-
fiers comprises a mixture of alkylaryl sulphonates, poly-
oxyalkylene glycols and oxyalkylated alkylphenolic re-
sins. Such products are supplied by Petrolite Corporation
under the TOLAD trademark. One such propriety product,
identified as TOLAD 286K, is understood to be a mixture of
these components dissolved in a solvent composed of alkyl
benzenes. A related product, TOLAD 2B6, is also suit-
able. In this case the product apparently contains the
2~82s
-- 19 --
same kind of active ingredients dissolved in a solvent
composed of heavy aromatic naphtha and isopropanol.
However, other known demulsifiers can be used.
Metal Deactivators. Generally speaking, metal de-
activators fall into two broad categories. One cateqory
comprises the passivators which are considered to react
with the metal surface and thereby passivate the surface.
The other category comprises the chelators, i.e., sub-
stances which have the capability of reacting or complex-
ing with dissolved metal and/or metal ions. An example of
the passivator type is the thiadiazoles such as HITEC~ 314
additive (Ethyl Petroleum Additives, Ltd.; Ethyl Petroleum
Additives, Inc.). Examples of the chelator type of metal
deactivators include 8-hydroxyquinoline, ethylene diamine
tetraacetic acid, ~-diketones such as acetylacetone,
~-ketoesters such as octyl acetoacetate, and the like.
The preferred metal deactivators which are generally
regarded as chelators, are Schiff bases, such as N,N'-di-
salicylidene-1,2-ethanediamine, N,N'-disalicylidene-1,2-
propanediamine, N,N'-disalicylidene-1,2-cyclohexane-di-
amine, and N,N"-disalicylidene-N'-methyl-dipropylene-tri-
amine. Thus a wide variety of known metal deactivators
are available for use in the compositions of this inven-
tion. Mixtures of metal deactivators can be used.
Antifoam Aqents. Suitable antifoam agents include
silicones and organic polymers such as acrylate polymers.
20~3825
- 20 -
Various antifoam agents are described in Foam Control
Agents by H. T. Kerner (Noyes Data Corporation, 1976,
pages 125-176). The use of silicone oils such as are
available as articles of commerce is generally preferred.
Corrosion Inhibitors. It is also preferred pursu-
ant to this invention to employ in the fuel compositions a
suitable quantity of a corrosion or rust inhibitor. This
may be a single compound or a mixture of compounds having
the property of inhibiting corrosion of metallic sur-
faces. In some cases compounds are known which act not
only as corrosion inhibitors but as metal deactivators in
passivating the surface of the metal and thereby inhibit-
ing corrosion.
Among suitable corrosion inhibitors for use in
accordance with preferred embodiments of this invention
are the thiazoles, triazoles and thiadiazoles. Examples
of such compounds include benzotriazole, tolyltriazole,
octyltriazole, decyltriazole, dodecyltriazole, 2-mercapto
benzothiazole, 2,5-dimercapto-1,3,4-thiadiazole, 2-mercap-
to-5-hydrocarbylthio-1,3,4-thiadiazoles, 2-mercapto-5-
hydrocarbyldithio-1,3,4-thiadiazoles, 2,5-bis(hydrocarbyl-
thio)-1,3,4-thiadiazoles, and 2,5-(bis)hydrocarbyldithio)-
1,3,4-thiadiazoles. A number of these materials are avail-
able as articles of commerce.
~5 Other types of useful corrosion inhibitors include
dimer and trimer acids such as are produced from tall oil
2~3825
fatty acids, oleic acid, linoleic acid, etc.; alkenyl
succinic acid and alkenyl succinic anhydride corrosion
inhibitors such as tetrapropenylsuccinic acid, tetrapro-
penylsuccinic anhydride, dodecenylsuccinic acid, dodecenyl-
succinic anhydride, hexadecenylsuccinic acid, and similarcompounds. Also useful are derivatives of alkenyl succi-
nic acids and anhydrides such as half esters of alkenyl
succinic acids having 8 to 24 carbon atoms in the alkenyl
group with alcohols such as diols and polyglycols and
imides and amides of alkenyl succinic acids and anhydrides
having 8 to 24 carbon atoms in the alkenyl group, for
example the reaction product of dodecenyl succinic acid or
anhydride with a polyethylene polyamine, further reacted
with a fatty acid such as oleic acid. Also useful are
aminosuccinic acids or derivatives thereof represented by
the formula:
R6 o
R7- C - C - oR5
R
N - C - C - O
R3 / R2 O
wherein each of R1, R2, R5, R6 and R7 is, independently, a
hydrogen atom or a hydrocarbyl group containing 1 to 30
carbon atoms, and wherein each of R3 and R4 is, inde-
pendently, a hydrogen atom, a hydrocarbyl group containing1 to 30 carbon atoms, or an acyl group containing from 1
2~382~ ~
- 22 -
to 30 carbon atoms. The groups Rl, R2, R3, R4, R5, R6
and R7, when in the form of hydrocarbyl groups, can be,
for example, alkyl, cycloalkyl or aromatic containing
groups. Preferably Rl and R5 are the same or dif-
ferent straight-chain or branched-chain hydrocarbon radi-
cals containing 1-20 carbon atoms. Most preferably, Rl
and R5 are saturated hydrocarbon radicals containing 3-6
carbon atoms. R2, either R3 or R4, R6 and R7, when in the
form of hydrocarbyl groups, are preferably the same or
different straight-chain or branched-chain saturated
hydrocarbon radicals. Preferably a dialkyl ester of an
aminosuccinic acid is used in which R1 and R5 are the
same or different alkyl groups containing 3-6 carbon
atoms, R2 is a hydrogen atom, and either R3 or R4 is
an alkyl group containing 15-20 carbon atoms or an acyl
group which is derived from a saturated or unsaturated
carboxylic acid containing 2-10 carbon atoms.
Most preferred of the aminosuccinic acid derivative
is a dialkylester of an aminosuccinic acid of the above
formula wherein Rl and R5 are isobutyl, R2 is a
hydrogen atom, R3 is octadecyl and/or octadecenyl and
R4 is 3-carboxy-1-oxo-2-propenyl. In such ester R6
and R7 are most preferably hydrogen atoms.
Lubricity Agents The compositions of this inven-
tion may also contain lubricity agents such as sulfurizedfats, sulfurized isobutylene, dialkyl polysulfides, and
2~382~ ~
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sulphur-bridged phenols such as nonylphenol polysulfide.
Also useful as lubricity agents are fatty acids and t.heir
derivatives such as dimer or trimer acids such as are
produced from tall oil fatty acids, oleic acid, linoleic
acid, etc.
Friction Modifiers. Another type of additives
which may be included in the compositions of this inven-
tion are friction modifiers such as aliphatic amines or
ethoxylated aliphatic amines, aliphatic fatty acid amides,
aliphatic carboxylic acids, aliphatic carboxylic esters,
aliphatic carboxylic ester-amides, aliphatic phosphonates,
aliphatic phosphates, aliphatic thiophosphonates, ali-
phatic thiophosphates, etc., wherein the aliphatic group
usually contains above about eight carbon atoms so as to
render the compound suitably soluble in hydrocarbons.
Also suitable are aliphatic substituted succinimides
formed by reacting one or more aliphatic succinic acids or
anhydrides with ammonia such as are described in EP
20,037.
Solvents. Various types of solvents or carriers
are available for use in formulating the compositions of
this invention. These include hydrocarbons of suitable
viscosities and boiling ranges such as high boiling
aromatic naphtha, process oil, kerosene, and the like
including oligomers and hydrogenated oligomers of alkenes
such as hydrogenated decene-1 dimer or trimer. Also
r 20~8%~ -
useful are alcohols and esters especially higher alcohols
such as liquid alkanols having at least eight carbon
atoms. An especialy useful solvent is isodecanol.
Still other components may be utilised in their
customary amounts in the compositions of this invention.
These include aromatic amine antioxidants or stabilizers
such as N,N'-di-sec-butyl-p-phenylenediamine, phenyl-~-
naphthylamine, and 4-isopropylaminodiphenylamine; cetane
improvers such as organic nitrate esters or fuel soluble
peroxides, hydroperoxides or peroxyesters; metal-contain-
ing combustion improvers such as ferrocene and ferrocene
derivatives, cyclopentadienyl manganese carbonyl compounds
such as cyclopentadienyl manganese tricarbonyl and methyl-
cyclopentadienyl manganese tricarbonyl, and metallic salts
such as manganese oleate, iron naphthenate, copper naphthe-
nate, cobalt naphthenate, nickel oleate, and manganese
naphthenate: dyes; and the like.
Concentrations and Proportions. As noted above, a
critical feature of this invention is to employ a suffi-
ciently high concentration of the fuel-soluble ashless dis-
persant to achieve prompt reduction in noxious emissions
on combustion of the fuel. In other words, rather than
relying upon a gradual clean up of engine or burner parts
with concomitant gradual reduction in emissions, this
invention achieves virtually immediate, dramatic reduc-
tions in noxious emissions because of the high concentra-
2os382,5
tion of ashless dispersant employed in the fuel. Theminimum amount of ashless dispersant needed to achieve
such a substantially instantaneous reduction in emissions
will vary to some extent depending upon the character and
makeup of the hydrocarbonaceous middle distillate fuel in
which the dispersant is employed. However, generally
speaking, the minimum amount will fall within the range of
50 to 60 ppm. Ordinarily the fuels will contain no more
than about 5,000 ppm of the dispersant although even
higher concentrations may be used in situtations where
such higher concentrations can be justified or are needed.
In general, the other additive components of the
compositions of this invention are employed in minor
amounts sufficient to improve the performance charac-
teristics and properties of the base fuel. The amountswill thus vary in accordance with such factors as the type
of base fuel, the type of service for which the fuel
composition is intended, and the performance character-
istics desired in the finished fuel. However, generally
speaking, the following concentrations (parts per million
by weight) of the components (active ingredients) in the
fuels are typical:
Typical Preferred
Ranae Ranqe
Hindered phenolic antioxidant 0 - 300 5 - 50
Demulsifying agent 0 - 300 2 - 75
Metal deactivator 0 - 100 0.5 - 25
Foam inhibitor 0 - 100 0.5 - 50
Corrosion inhibitor 0 - 100 0.5 - 50
Lubricity additive 0 - 100 0.5 - 50
20~382~ ~
- 26 -
It will be appreciated that the individual compo-
nents employed can be separately blended into the fuel or
can be blended therein in various subcombinations, if
desired. Ordinarily, the particular sequence of such
blending steps is not critical. Moreover, such components
can be blend~d in the form of separate solutions in a
diluent. It is preferable, however, to blend the compo-
nents used in the form of an additive concentrate of this
invention, as this simplifies the blending operations,
reduces the likelihood of blending errors, and takes
advantage of the compatibility and solubility charac-
teristics afforded by the overall concentrate.
The additive concentrates of this invention will
contain the components used in amounts proportioned to
yield finished fuels consistent with the concentrations
tabulated above. In most cases, the additive concentrate
will contain one or more diluents such as light mineral
oils and/or higher alcohols to facilitate handling and
blending of the concentrate. Thus concentrates containing
up to 90% by weight of one or more diluents or solvents
can be used.
Hydrocarbonaceous Fuels. In principle, the advan-
tages of this invention may be achieved in any distilled
or distillable liquid hydrocarbonaceous fuel derived from
petroleum, coal, shale and/or tar sands. In most in-
2~S382~
- 27 -
stances, at least under present circumstances, the base
fuels will be derived primarily, if not exclusively, from
petroleum.
The invention is thus applicable to such fuels as
kerosene, jet fuel, aviation fuel, diesel fuel, home
heating oil, light cycle oil, heavy cycle oil, light gas
oil, heavy gas oil, and in general, any liquid hydrocar-
bonaceous product suitable for combustion either in an
engine (e.g., diesel fuel, gas turbine fuels, etc.) or in
a burner apparatus ~e.g., gas oils, home heating oils,
etc.). Other suitable fuels may include liquid fuels
derived from biomass, such as vegetable oils (e.g., rape-
seed oil, jojoba oil, cottonseed oil, etc.); or refuse-
derived liquid fuels such as fuels derived from municipal
and/or industrial wastes; or waste oils and/or liquid
waste biomass and its derivatives; or mixtures of any ofthe foregoing substances.
In many cases, specifications exist for various
hydrocarbonaceous fuels or grades thereof, and in any
event the nature and character of such fuels are well-
known and reported in the literature. Generally speaking,so-called middle distillate fuels boil within the range of
about 140~C to about 400C.
~he practise and advantages of this invention will
be still further apparent from the following illustrative
example wherein all percentages are by weight.
20~382~
- 28 -
EXAMPLE
An additive concentrate of this invention was
formed by blending together the following components in
the proportions specified:
5 Succinimide ashless dispersant(l) 37.50%
2,6-Di-tert-butyl-~-dimethylamino-p-cresol 3.75%
N,N'-disalicylidene-1,2-propanediamine(2)0.50%
Corrosion inhibitor(3) 3.75%
Demulsifying agent(4) 4.25%
10 Silicone foam inhibitor 2.50%
Lubricity additive(5) 3.75%
Aromatic naphtha solvent 9.50%
Isodecanol solvent 34.50%
(1) Polyisobutenyl succinimide of tetraethylenepentamine
in which the number average molecular weight of the
polyisobutenyl group is about 950; used as a 75% solution
in high aromatic solvent.
(2) Used as an 80% solution in xylene.
(3) Low molecular weight succinimide type corrosion
inhibitor; used as a 50% solution in process oil.
(4) Used as a 60% solution in kerosene.
(5) Used as a 61.5% solution in a mixture of process oil
and kerosene.
The additive concentrate was blended into commer-
cially available diesel fuels at a concentration of 400
ppm. Thus, the fuels contained approximately ~12.5 ppm of
20~382~
- 29 -
succinimide ashless dispersant (active ingredient) and 15
ppm of 2,6-di-tert-butyl-~-dimethylamino-p-cresol. These
blended fuels were used in the operation of two different
diesel engines. one was a Volvo TD121F 12 litre turbo-
charged intercooled truck engine. The other engine was a4-cylinder Mercedes-Benz 200D passenger car engine with a
displacement of 1.997 litres and a rated power of 53 kw.
The base fuel used in the Volvo truck engine tests had a
cetane number of 48.9 (per ASTM D 976-80), a density at
15C of 0.853 (per ASTM D 1298), an API gravity of ~4.2, a
total sulphur content of 0.125 weight percent, a content
of aromatics of 39% by volume (per ASTM D 1019-68) (Mod)),
an initial boiling point of 176-C and a final boiling
point of 362C (per ASTM D 86).
The Volvo truck engine test was run utilising the
ECE R49 13-mode cyclé test firstly to give triplicate
results on the clear (unadditised) diesel fuel (the
commercially available diesel fuel described above) and
then immediately in triplicate on the above diesel fuel of
this invention. Thereafter, a further triplicate series
of tests were run on the additised fuel, but for this
triplicate series, the measurements were made only after
60 hours of running and the cycle used only for this 60
hours of running employed three typical modes rather than
the full 13 modes employed in the previous two series. A
20~382~
- 30 -
summary of the results so obtained is set forth in Table
1. .
Table 1
Volvo Truck Engine ECE R49-13 Mode Results -
Grams Per Horsepower Hour
Fuel of This Invention
Tested Tested
Clear Fuel Immediately After 60 Hrs.
Emissions
HC, avg. 0.619 0.546 0.487
% change -- -11.8 -21.3
NOX, avg. 8.91 8.88 9.26
% change -- -0.3 +3.4
CO, avg. 3.395 2.996 2.450
% change -- -11.8 -27.8
Particulates, avg. 0.4804 0.4420 0.3779
% change -- -8.0 -21.3
Fuel Consumption
BSFC , avg. 161.47 159.52 159.02
% change -- -1.21 -1.52
* Brake standard fuel consumption
It can be seen from Table 1 that the fuel of this
invention gave an almost immediate dramatic reduction in
emissions of hydrocarbons, CO, and particulates. In addi-
tion, the fuel of this invention gave an almost immediate
improvement in fuel economy. Moreover, these improvements
continued and in some cases became even greater after 6
hours of test.
The Mercedes-Benz 200D passenger car tests were
road tests using a vehicle which had already been driven
- 31 - 20~382~
in normal service for 135,500 ~n with service intervals of
10,000 km and without injector replacement. The fuel was
switched to using the fuel of this invention and the
emissions and fuel consumption change ~ere measured both
immediately and after an additional 1,000 km of driving.
Four different standard driving cycle systems were evalu-
ated; namely Federal Test Procedure 75 ("FTP 75"), Federal
Test Procedure 72 ("FTP 72"), Highway Fuel Economy Test
("HW FET"), and ECE Regulation 15-04 ("ECE 15"). The
results of these tests are summarized in Table 2.
Table 2
Mercedes-Benz Passenger Car Test Results
Fuel of This Invention
Tested Immediately
FTP 75 FTP 72 HW FET ECE 15
Emissions
HC, % change -16 -11 -29 -10
CO, % change -5 -6 -6 -6
Particulates, % change -lS -5 -10 +S
20 Fuel Consumption
Fuel Consumption,
change -1.5 -2.5 -1 -2
Tested After 1000 km
FTP 75 FTP 72 HW FET ECE 15
Emissions
HC, % change -20 -22 -48 -3
CO, % change -6 -8 -11 o
Particulates, % change -11 -1 -2 +3
Fuel Consum~tion
Fuel Consumption,
% change -2 -4 -3 -4.5
20~382~
- 32 -
Tests were also conducte~ using a diesel fuel not
of this invention containing a very similar additive
formulation as described above, but at a lower concen-
tration of ashless dispersant. In this test the fuel was
evaluated in a Peugeot 309 GLD diesel passenger car
equipped with a 1,905 cc 4-cylinder, indirect injection
diesel engine. The additive formulation (deemed suitable
for the practise of this invention if utilised at a suit-
ably high concentration) was as follows:
10 Succinimide ashless dispersant(l) 17.0%
2,6-Di-tert-butyl-~-dimethylamino-p-cresol 2.5%
Methylene-bridged alkyl phenol(2) 10.0%
N,N'-disalicylidene-1,2-propanediamine(3) 1.0%
Corrosion inhibitor(4) 5.0%
15 Demulsifying agent(5) 4-0%
Silicone foam inhibitor 3.8%
Aromatic naphtha solvent 34.0%
Isodecanol solvent 22.7%
(1) Polyisobutenyl succinimide of tetraethylenepentamine
in which the number average molecular weight of the
polyisobutenyl group is about 950; used as a 77% solution
in process oil.
(2) A 50% solution in process oil of a hindered phenol
mixture containing 85% methylene-bridged phenol and 2%
solvent.
~3) Used as an 80% solution in xylene.
(4) Low molecular weight succinimide type corrosion
inhibitor: used as a 50% solution in process oil.
(5) Used as a 60% solution in kerosene.
2~s3s2~
- 33 -
This additive concentrate was blended into the fuel
at a concentration of 200 ppm. Accordingly, the fuel
contained approximately 26.2 ppm of the active ashless
dispersant and 5.0 ppm of the 2,6-di-tert-butyl-~-dimeth-
ylamino-p-cresol.
The test operation involved 967 km dynamometer dis-
tance accumulation using a mixed urban/highway driving
cycle. This was followed by measurements of emissions
according to the ECE 15-04 cycle. The results, expressed
in terms of grams of emissions per test, of duplicate
tests performed in this manner are as follows:
Emissions Untreated Fuel Treated Fuel
C0 3.457 3.915
HC 0.759 0.967
NOX 4.495 4.608
It can be seen that in each instance the treated
fuel not of this invention resulted in an increase in
noxious emissions.
