U.S. patent application number 12/266395 was filed with the patent office on 2010-05-06 for conductivity-improving additives for fuel.
Invention is credited to Joshua J. Bennett, John Donner.
Application Number | 20100107482 12/266395 |
Document ID | / |
Family ID | 41426577 |
Filed Date | 2010-05-06 |
United States Patent
Application |
20100107482 |
Kind Code |
A1 |
Bennett; Joshua J. ; et
al. |
May 6, 2010 |
CONDUCTIVITY-IMPROVING ADDITIVES FOR FUEL
Abstract
A fuel additive composition, fuel comprising said additive, and
methods of use thereof are provided. The fuel additive composition
comprises a synergistic combination of a hydrocarbyl-substituted
succinimide dispersant and a compound of the following formula:
##STR00001## and tautomers and enantiomers thereof, wherein R.sup.3
is a hydrocarbyl group having a number average molecular weight
ranging from about 100 to about 5000, and wherein the weight ratio
of (a) to (b) ranges from about 5:1 to about 1:5. The fuel additive
composition is present in fuel in an amount sufficient to improve
the conductivity properties of the fuel.
Inventors: |
Bennett; Joshua J.;
(Richmond, VA) ; Donner; John; (Richmond,
VA) |
Correspondence
Address: |
Mannava & Kang, P.C.
11240 Waples Mill Road, Suite 300
Fairfax
VA
22030
US
|
Family ID: |
41426577 |
Appl. No.: |
12/266395 |
Filed: |
November 6, 2008 |
Current U.S.
Class: |
44/403 ;
44/416 |
Current CPC
Class: |
C10L 1/2383 20130101;
C10L 1/238 20130101; C10L 1/232 20130101; C10L 1/22 20130101; C10L
1/143 20130101; C10L 1/224 20130101; C10L 10/18 20130101 |
Class at
Publication: |
44/403 ;
44/416 |
International
Class: |
C10L 1/18 20060101
C10L001/18; C10L 1/22 20060101 C10L001/22 |
Claims
1. A fuel additive composition comprising a synergistic combination
of: (a) a hydrocarbyl-substituted succinimide dispersant, and (b) a
compound of formula (III): ##STR00011## and tautomers and
enantiomers thereof, wherein R.sup.3 is a hydrocarbyl group having
a number average molecular weight ranging from about 100 to about
5000, and wherein the weight ratio of (a) to (b) ranges from about
5:1 to about 1:5.
2. The fuel additive composition of claim 1, wherein the compound
of formula (III) comprises the reaction product of (i) a
hydrocarbyl carbonyl compound; and (ii) an amine compound or salt
thereof of formula (I) ##STR00012## wherein R is selected from the
group consisting of a hydrogen and a hydrocarbyl group containing
from about 1 to about 15 carbon atoms, and R.sup.1 is selected from
the group consisting of hydrogen and a hydrocarbyl group containing
from about 1 to about 20 carbon atoms.
3. The fuel additive composition of claim 1, wherein the
hydrocarbyl carbonyl compound comprises a hydrocarbyl-substituted
dicarboxylic acid or anhydride.
4. The fuel additive composition of claim 3, wherein the
hydrocarbyl substituent of comprises a hydrocarbyl group having a
number average molecular weight ranging from about 100 to about
5,000.
5. The fuel additive composition of claim 3, wherein the
hydrocarbyl substituent comprises a polyisobutylene group derived
from high reactivity polyisobutenes having at least 60% or more
terminal olefinic double bonds.
6. The fuel additive composition of claim 2, wherein (ii) comprises
a salt of aminoguanidine.
7. The fuel additive composition of claim 2, wherein (ii) comprises
a salt of guanidine.
8. The fuel additive composition of claim 2, wherein (ii) comprises
aminoguanidine bicarbonate.
9. The fuel additive composition of claim 1, wherein (a) is present
in an amount ranging from about 1 wt. % to about 70 wt. %, relative
to the total weight of the additive composition.
10. The fuel additive composition of claim 1, wherein (b) is
present in an amount ranging from about 1 wt. % to about 70 wt. %,
relative to the total weight of the additive composition.
11. A fuel composition comprising: a major amount of fuel; and a
minor amount of a synergistic additive composition comprising: (a)
a hydrocarbyl-substituted succinimide dispersant, and (b) a
compound of formula (III): ##STR00013## and tautomers and
enantiomers thereof, wherein R.sup.3 is a hydrocarbyl group having
a number average molecular weight ranging from about 100 to about
5000, and wherein the weight ratio of (a) to (b) ranges from about
5:1 to about 1:5.
12. The fuel composition of claim 11, wherein the compound of
formula (III) comprises the reaction product of (i) a hydrocarbyl
carbonyl compound; and (ii) an amine compound or salt thereof of
formula (I) ##STR00014## wherein R is selected from the group
consisting of a hydrogen and a hydrocarbyl group containing from
about 1 to about 15 carbon atoms, and R.sup.1 is selected from the
group consisting of hydrogen and a hydrocarbyl group containing
from about 1 to about 20 carbon atoms.
13. The fuel composition of claim 11, wherein the hydrocarbyl
carbonyl compound comprises a hydrocarbyl-substituted dicarboxylic
acid or anhydride.
14. The fuel composition of claim 13, wherein the hydrocarbyl
substituent comprises a hydrocarbyl group having a number average
molecular weight ranging from about 100 to about 5,000.
15. The fuel composition of claim 13, wherein the hydrocarbyl
substituent comprises a polyisobutylene group derived from high
reactivity polyisobutenes having at least 60% or more terminal
olefinic double bonds.
16. The fuel composition of claim 12, wherein (ii) comprises a salt
of aminoguanidine.
17. The fuel composition of claim 12, wherein (ii) comprises a salt
of guanidine.
18. The fuel composition of claim 12, wherein (ii) comprises
aminoguanidine bicarbonate.
19. The fuel composition of claim 11, wherein (a) is present in an
amount ranging from about 5 ppm to about 500 ppm.
20. The fuel composition of claim 11, wherein (b) is present in an
amount ranging from about 1 ppm to about 200 ppm.
21. The fuel composition of claim 11, further comprising at least
one additive selected from the group consisting of antifoam agents,
dispersants, detergents, antioxidants, thermal stabilizers, carrier
fluids, metal deactivators, dyes, markers, corrosion inhibitors,
biocides, antistatic additives, drag reducing agents, friction
modifiers, demulsifiers, emulsifiers, dehazers, anti-icing
additives, antiknock additives, surfactants, cetane improvers,
corrosion inhibitors, cold flow improvers, pour point depressants,
solvents, demulsifiers, lubricity additives, extreme pressure
agents, viscosity index improvers, seal swell agents, amine
stabilizers, combustion improvers, dispersants, conductivity
improvers, metal deactivators, marker dyes, organic nitrate
ignition accelerators, manganese tricarbonyl compounds, and
mixtures thereof.
22. A method of improving the conductivity of a fuel comprising:
combining a major amount of fuel, and a minor amount of a
synergistic additive composition comprising: (a) a
hydrocarbyl-substituted succinimide dispersant, and (b) a compound
of formula (III): ##STR00015## and tautomers and entantiomers
thereof, wherein R.sup.3 is a hydrocarbyl group having a number
average molecular weight ranging from about 100 to about 5000, and
wherein the weight ratio of (a) to (b) ranges from about 5:1 to
about 1:5.
Description
FIELD OF THE INVENTION
[0001] This disclosure relates generally to fuel additive
compositions. More specifically, the present disclosure is directed
to fuel additive compositions that are effective to enhance the
conductivity properties of fuel, and methods of use thereof.
BACKGROUND OF THE INVENTION
[0002] It is widely known that electrostatic charges can be
frictionally transferred between two dissimilar, nonconductive
materials. When this occurs, the electrostatic charge thus created
appears at the surfaces of the contacting materials. The magnitude
of the generated charge is dependent upon the nature of and, more
particularly, the respective conductivity of each material. For
example, electrostatic charging occurs when water settles through a
hydrocarbon solution. This situation greatly interests the
petroleum industry, for when such charges are built up in or around
flammable liquids, their eventual discharge can lead to incendiary
sparking, and perhaps to a serious fire or explosion.
[0003] While incendiary sparking is a problem in the petroleum
industry, the potential for fire and explosion is probably at its
greatest during product handling, transfer and transportation. For
example, static charges are known to accumulate in solvents and
fuels when they flow through piping, especially when these liquids
flow through high surface area or "fine" filters and other process
controls, such as is common during tank truck filling.
Countermeasures designed to prevent accumulation of electrostatic
charges on a container being filled and to prevent sparks by
conducting the container to ground can be employed, such as
container grounding (i.e. "earthing") and bonding. But it has been
recognized that these measures are inadequate to deal successfully
with all of the electrostatic hazards presented by hydrocarbon
fuels.
[0004] Alone, grounding and bonding are not sufficient to prevent
electrostatic build-up in low conductivity, volatile organic
liquids such as distillate fuels like diesel, gasoline, jet fuel,
turbine fuels, and kerosene. Similarly, grounding and bonding do
not prevent static charge accumulation in relatively clean (i.e.,
contaminant free) light hydrocarbon oils such as organic solvents
and cleaning fluids. This is because the conductivity of these
organics is so low that a static charge moves very slowly through
these liquids and can take a considerable time to reach the surface
of a grounded, conductive container. Until this occurs, a high
surface-voltage potential can be achieved, which can create an
incendiary spark, thereby causing ignition or explosion.
[0005] One can directly attack the source of the increased hazard
presented by these low conductivity organic liquids by increasing
the conductivity of the liquid with additives. The increased
conductivity of the liquid will substantially reduce the time
necessary for any charges that exist in the liquid to be conducted
away by the grounded inside surface of the container. Various
compositions are known for use as additives to increase the
electrical conductivity of these liquids.
[0006] For example, in the past, halogen-containing additives
introduced into fuels have played a significant role in achieving
improved conductivity properties in fuels. While these
halogen-containing additives are effective as conductivity agents,
in certain situations, some halogen-containing hydrocarbon
compounds have been linked to human and animal health risks, as
well as environmental degradation. Legislative enactments,
including the 1990 amendment to "The Clean Air Act" in the United
States, signal a trend away from the continued permissible use in
media of halogen-containing compounds. Even where the use of
halogen-containing additives is still permitted, stringent
regulations often govern the use, storage and, in particular, the
disposal of and/or treatment of waste streams containing these
compositions. Accordingly, a need exists to find fuel additives
that improve the conductivity of fuel without posing negative risks
to humans, animals, and the environment.
SUMMARY OF DISCLOSURE
[0007] In accordance with the disclosure, there is provided a fuel
additive composition comprising a synergistic combination of (a) a
hydrocarbyl-substituted succinimide dispersant, and (b) a compound
of formula (III):
##STR00002##
and tautomers and enantiomers thereof, wherein R.sup.3 is a
hydrocarbyl group having a number average molecular weight ranging
from about 100 to about 5000, and wherein the weight ratio of (a)
to (b) ranges from about 1:5 to about 5:1.
[0008] Another aspect of the disclosure provides a fuel composition
comprising a major amount of fuel; and a minor amount of a
synergistic additive composition comprising (a) a
hydrocarbyl-substituted succinimide dispersant, and (b) a compound
of formula (III):
##STR00003##
and tautomers and enantiomers thereof, wherein R.sup.3 is a
hydrocarbyl group having a number average molecular weight ranging
from about 100 to about 5000, and wherein the weight ratio of (a)
to (b) ranges from about 1:5 to about 5:1.
[0009] A further aspect of the disclosure provides a method of
improving the conductivity of a fuel comprising combining a major
amount of fuel, and a minor amount of a synergistic additive
composition comprising (a) a hydrocarbyl-substituted succinimide
dispersant, and (b) a compound of formula (III):
##STR00004##
and tautomers and enantiomers thereof, wherein R.sup.3 is a
hydrocarbyl group having a number average molecular weight ranging
from about 100 to about 5000, and wherein the weight ratio of (a)
to (b) ranges from about 1:5 to about 5:1.
[0010] Additional embodiments and advantages of the disclosure will
be set forth in part in the detailed description which follows,
and/or can be learned by practice of the disclosure. It is to be
understood that both the foregoing general description and the
following detailed description are exemplary and explanatory only
and are not restrictive of the disclosure, as claimed.
DETAILED DESCRIPTION OF DISCLOSURE
[0011] The present disclosure relates to a fuel additive
composition comprising (a) a hydrocarbyl-substituted succinimide
dispersant, and (b) a compound of formula (III):
##STR00005##
and tautomers and enantiomers thereof, wherein R.sup.3 is a
hydrocarbyl group having a number average molecular weight ranging
from about 100 to about 5000, and wherein the weight ratio of (a)
to (b) ranges from about 1:5 to about 5:1.
[0012] As used herein, "middle distillate fuel" is understood to
mean one or more fuels selected from the group consisting of diesel
fuel, biodiesel, biodiesel-derived fuel, synthetic diesel, jet
fuels, kerosene, diesel fuel treated with oxygenates for
particulate control, mixtures thereof, and other products meeting
the definitions of ASTM D975. As used herein, "biodiesel" is
understood to mean diesel fuel comprising fuel derived from
biological sources. In an aspect, the middle distillate fuel can
contain up to 30%, for example from about 0.5% to about 30%, such
as from about 10% to about 20%, fuel derived from biological
sources.
[0013] The middle distillate fuel can be derived from biological
sources such as oleaginous seeds, for example rapeseed, sunflower,
soybean seeds, and the like. The seeds can be submitted to grinding
and/or solvent extraction treatments (e.g., with n-hexane) in order
to extract the oil, which comprises triglycerides of saturated and
unsaturated (mono- and poly-unsaturated, in mixture with each
other, in proportions depending on the selected oleaginous seed)
C.sub.16-C.sub.22 fatty acids. The oil can be submitted to a
filtration and refining process, in order to remove any possible
free fats and phospholipids present, and can be submitted to a
transesterification reaction with methanol in order to prepare the
methyl esters of the fatty acids (fatty acid methyl esters, also
known as "FAME" and commonly referred to as biodiesel.)
[0014] As used herein, the term "hydrocarbyl group" or
"hydrocarbyl" is used in its ordinary sense, which is well-known to
those skilled in the art. Specifically, it refers to a group having
a carbon atom directly attached to the remainder of a molecule and
having a predominantly hydrocarbon character. Examples of
hydrocarbyl groups include: [0015] (1) hydrocarbon substituents,
that is, aliphatic (e.g., alkyl or alkenyl), alicyclic (e.g.,
cycloalkyl, cycloalkenyl) substituents, and aromatic-, aliphatic-,
and alicyclic-substituted aromatic substituents, as well as cyclic
substituents wherein the ring is completed through another portion
of the molecule (e.g., two substituents together form an alicyclic
radical); [0016] (2) substituted hydrocarbon substituents, that is,
substituents containing non-hydrocarbon groups which, in the
context of the description herein, do not alter the predominantly
hydrocarbon substituent (e.g., halo (especially chloro and fluoro),
hydroxy, alkoxy, mercapto, alkylmercapto, nitro, nitroso, and
sulfoxy); [0017] (3) hetero-substituents, that is, substituents
which, while having a predominantly hydrocarbon character, in the
context of this description, contain other than carbon in a ring or
chain otherwise composed of carbon atoms. Hetero-atoms include
sulfur, oxygen, nitrogen, and encompass substituents such as
pyridyl, furyl, thienyl, and imidazolyl. In general, no more than
two, or as a further example, no more than one, non-hydrocarbon
substituent will be present for every ten carbon atoms in the
hydrocarbyl group; in some embodiments, there will be no
non-hydrocarbon substituent in the hydrocarbyl group.
[0018] As used herein, the term "major amount" is understood to
mean an amount greater than or equal to 50 wt. %, for example from
about 80 to about 98 wt. % relative to the total weight of the
composition. Moreover, as used herein, the term "minor amount" is
understood to mean an amount less than 50 wt. % relative to the
total weight of the composition.
[0019] The compositions of the present disclosure can comprise a
compound of formula (III) comprising the reaction product of an
amine compound or salt thereof and a hydrocarbyl carbonyl compound.
Suitable amine compounds for use herein can be amine compounds of
salts thereof of formula (I):
##STR00006##
wherein R is selected from the group consisting of a hydrogen and a
hydrocarbyl group containing from about 1 to about 15 carbon atoms,
and R.sup.1 is selected from the group consisting of hydrogen and a
hydrocarbyl group containing from about 1 to about 20 carbon atoms.
Such amine compounds can be chosen from guanidines and
aminoguanidines or salts thereof, wherein R and R.sup.1 are as
defined above. Accordingly, the amine compound can be chosen from
the inorganic salts of aminoguanidienes and guanidines, such as the
halide, carbonate, bicarbonate, nitrate, phosphate, and
orthophosphate salts of aminoguanidines and guanidines. As used
herein, the term "guanidines" is understood to refer to guanidine
and guanidine derivatives, such as aminoguanidine. In an
embodiment, the amine compound for the preparation of the additive
can be aminoguanidine bicarbonate. Aminoguanidine bicarbonates are
readily obtainable from commercial sources, or can be prepared in a
well-known manner.
[0020] Suitable hydrocarbyl carbonyl compounds for use herein can
be any suitable compound having a hydrocarbyl moiety and a carbonyl
moiety, and that is capable of bonding with the amine compound to
form the additives of the disclosure. Non-limiting examples of
suitable hydrocarbyl carbonyl compounds include, but are not
limited to, hydrocarbyl substituted dicarboxylic acids or
anhydrides, such as hydrocarbyl-substituted succinic anhydrides,
hydrocarbyl-substituted succinic acids, and esters of
hydrocarbyl-substituted succinic acids.
[0021] In some aspects, the hydrocarbyl carbonyl compound can be a
hydrocarbyl-substituted succinic anhydride of formula (II):
##STR00007##
[0022] wherein R.sup.2 is a hydrocarbyl group having a number
average molecular weight ranging from about 100 to about 5,000,
such as from about 200 to about 3,000, as measured by gel
permeation chromatograph (GPC). Unless indicated otherwise,
molecular weights in the present disclosure are number average
molecular weights.
[0023] In some aspects, the R.sup.2 group of the hydrocarbyl
carbonyl compound can comprise one or more polymer units chosen
from linear or branched alkenyl units. For example, the alkenyl
units can comprise from about 2 to about 10 carbon atoms. In
embodiments, the R.sup.2 group can comprise one or more linear or
branched polymer units chosen from ethylene radicals, propylene
radicals, butylene radicals, pentene radicals, hexene radicals,
octene radicals, and decene radicals. In some aspects, the R.sup.2
group can be in the form of, for example, a homopolymer, copolymer,
or terpolymer. In an embodiment, the R.sup.2 group can be
isobutylene. Accordingly, in an embodiment, the R.sup.2 group can
be a homopolymer of polyisobutylene comprising from about 10 to
about 60 isobutylene groups, such as from about 20 to about 30
isobutylene groups. The compounds used to form the R.sup.2
hydrocarbyl groups can be formed by any suitable methods, such as
by conventional catalytic oligomerization of alkenes. A
non-limiting example of R.sup.2 can be a polyalkenyl radical, such
as a polyisobutylene radical, having a number average molecular
weight of from about 100 to about 5,000, such as from about 200 to
about 3,000, as measured by GPC.
[0024] In some aspects, the R.sup.2group of the hydrocarbyl
carbonyl compound can be formed from highly reactive
polyisobutylenes (HR-PIB) having relatively high terminal
vinylidene content. As used herein, "terminal vinylidene content"
is understood to mean terminal olefinic double bond content. In an
embodiment, the R.sup.2 group can be formed from HR-PIB having at
least about 60%, such as about 70% to about 90% and above, terminal
vinylidene content. There is a general trend in the industry to
convert to HR-PIB, and well known HR-PIBs are disclosed, for
example, in U.S. Pat. No. 4,152,499, the disclosure of which is
herein incorporated by reference in its entirety.
[0025] The hydrocarbyl carbonyl compounds can be made using any
suitable method. Methods for forming hydrocarbyl carbonyl compounds
are well known in the art. One example of a known method for
forming a hydrocarbyl carbonyl compound comprises blending a
polyolefin and an anhydride, such as maleic anhydride. The
polyolefin and anhydride reactants can be heated to temperatures
of, for example, about 150.degree. C. to about 250.degree. C.,
optionally, with the use of a catalyst, such as chlorine or
peroxide. Another exemplary method of making the hydrocarbyl
carbonyl compounds is described in U.S. Pat. No. 4,234,435, which
is incorporated herein by reference in its entirety.
[0026] In some aspects, approximately one mole of maleic anhydride
can be reacted per mole of polyolefin, such that the resulting
hydrocarbyl-substituted succinic anhydride has about 0.8 to about 1
succinic anhydride group per hydrocarbyl group. In other aspects,
the weight ratio of succinic anhydride groups to hydrocarbyl group
can range from about 0.5 to about 3.5, such as from about 1 to
about 1.1.
[0027] Examples of hydrocarbyl carbonyl compounds useful herein
include, but are not limited to, such compounds as
dodecenylsuccinic anhydrides, C.sub.16-18 alkenyl succinic
anhydride, and polyisobutenyl succinic anhydride (PIBSA). In some
embodiments, the PIBSA can have a polyisobutylene substituent with
a terminal vinylidene content ranging from about 4% to at least
about 60%, such as about 70% to about 90% and above. In some
embodiments, the ratio of the number of carbonyl groups to the
number of hydrocarbyl moieties in the hydrocarbyl carbonyl compound
can range from about 1:1 to about 6:1.
[0028] The hydrocarbyl carbonyl and amine compounds described above
can be mixed together under any suitable conditions to provide the
desired reaction products of the present disclosure. In an aspect,
the reactant compounds can be mixed together in a mole ratio of
hydrocarbyl carbonyl compound to amine compound ranging from about
2:1 to about 1:2.5. For example, the mole ratio of the reactants
can range from about 1:1 to about 1:2.2. Suitable reaction
temperatures can range from about 155.degree. C. to about
200.degree. C. at atmospheric pressure. For example, reaction
temperatures can range from about 160.degree. C. to about
190.degree. C. Any suitable reaction pressures can be used, such as
subatmospheric pressures or superatmospheric pressures. However,
the range of temperatures can be different from those listed where
the reaction is carded out at other than atmospheric pressure. The
reaction can be carried out for a period of time within the range
of about 1 hour to about 8 hours, preferably, within the range of
about 2 hours to about 6 hours.
[0029] Without desiring to be bound by theoretical considerations,
it is believed that the reaction product of the amine and
hydrocarbyl carbonyl compound is an aminotriazole compound, such as
a bis-aminotriazole compound of formula (III):
##STR00008##
including tautomers and enantiomers thereof, wherein R.sup.3 has a
number average molecular weight ranging from about 100 to about
5000, and comprises from about 40 to about 80 carbon atoms. In an
embodiment, R.sup.3 is a polyisobutenyl substituent, for example a
polyisobutenyl substituent formed from HR-PIB having at least about
60%, such as about 70% to about 90% and above, terminal vinylidene
content. The reaction product-can contain at least one
aminotriazole group. The five-membered ring of the triazole is
considered to be aromatic. The aminotriazoles can be fairly stable
to oxidizing agents and can be extremely resistant to hydrolysis.
It is believed, although it is not certain, that the reaction
product is polyalkenyl bis-3-amino-1,2,4-triazole. Such a product
contains a relatively high nitrogen content, within the range of
about 1.8 wt % to about 2.9 wt % nitrogen.
[0030] In some aspects of the present disclosure, the disclosed
fuel compositions can comprise a dispersant, such as an
amine-containing dispersant. Suitable amine-containing dispersants
can comprise hydrocarbyl-substituted succinimide dispersants. The
hydrocarbyl substituent of the dispersant can have a number average
molecular weight ranging from about 100 to about 5000, such as
about 500 to about 5000, as determined by GPC.
[0031] As used herein the term "succinimide" is meant to encompass
the completed reaction product from reaction between an amine and a
hydrocarbyl-substituted succinic acid or anhydride (or like
succinic acylating agent), and is intended to encompass compounds
wherein the product may have amide, and/or salt linkages in
addition to the imide linkage of the type that results from the
reaction of or contact with an amine and an anhydride moiety.
[0032] Suitable hydrocarbyl-substituted succinic anhydrides can be
formed by first reacting an olefinically unsaturated hydrocarbon of
a desired molecular weight with maleic anhydride. Reaction
temperatures of about 100.degree. C. to about 250.degree. C. can be
used. With higher boiling olefinically-unsaturated hydrocarbons,
good results are obtained at about 200.degree. C. to about
250.degree. C. This reaction can be promoted by the addition of
chlorine.
[0033] Typical olefins include, but are not limited to, cracked wax
olefins, linear alpha olefins, branched chain alpha olefins,
polymers and copolymers of lower olefins. The olefins can be chosen
from ethylene, propylene, butylene, such as isobutylene, 1-octane,
1-hexene, 1-decene and the like. Useful polymers and/or copolymers
include, but are not limited to, polypropylene, polybutenes,
polyisobutene, ethylene-propylene copolymers, ethylene-isobutylene
copolymers, propylene-isobutylene copolymers, ethylene-1-decene
copolymers and the like.
[0034] In an aspect, the hydrocarbyl substituents of the
hydrocarbyl-substituted succinic anhydrides can be derived from
butene polymers, for example polymers of isobutylene. Suitable
polyisobutenes for use herein include those formed from HR-PIB
having having at least about 60%, such as about 70% to about 90%
and above, terminal vinylidene content. Suitable polyisobutenes can
include those prepared using BF.sub.3 catalysts. The average number
molecular weight of the hydrocarbyl substituent can vary over a
wide range, for example from about 100 to about 5000, such as from
about 500 to about 5000, as determined by GPC.
[0035] Carboxylic reactants other than maleic anhydride can be
employed such as maleic acid, fumaric acid, malic acid, tartaric
acid, itaconic acid, itaconic anhydride, citraconic acid,
citraconic anhydride, mesaconic acid, ethylmaleic anhydride,
dimethylmaleic anhydride, ethylmaleic acid, dimethylmaleic acid,
hexylmaleic acid, and the like, including the corresponding acid
halides and lower aliphatic esters.
[0036] The mole ratio of maleic anhydride to olefin can vary
widely. It can vary from about 5:1 to about 1:5, for example from
about 3:1 to about 1:3, and as a further example, the maleic
anhydride can be used in stoichiometric excess to force the
reaction to completion. The unreacted maleic anhydride can be
removed by vacuum distillation.
[0037] Any of numerous polyamines can be utilized in preparing the
hydrocarbyl-substituted succinimide dispersant. Non-limiting
exemplary polyamines can include aminoguanidine bicarbonate (AGBC),
diethylene triamine (DETA), triethylene tetramine (TETA),
tetraethylene pentamine (TEPA), pentaethylene hexamine (PEHA) and
heavy polyamines. A heavy polyamine can comprise a mixture of
polyalkylenepolyamines comprising small amounts of lower polyamine
oligomers such as TEPA and PEHA, but primarily oligomers with 7 or
more nitrogens, 2 or more primary amines per molecule, and more
extensive branching than conventional polyamine mixtures.
Additional non-limiting polyamines which can be utilized in
preparing the hydrocarbyl-substituted succinimide dispersant are
disclosed in U.S. Pat. No. 6,548,458, the disclosure of which is
incorporated herein by reference in its entirety. In an embodiment,
the polyamine can comprise tetraethylene pentamine (TEPA).
[0038] In an embodiment, the dispersant can include compounds of
formula (IV):
##STR00009##
wherein n represents 0 or an integer of from 1 to 5, and R.sup.2 is
a hydrocarbyl substituent as defined above. In an embodiment, n is
3 and R.sup.2 is a polyisobutenyl substituent, such as that derived
from polyisobutylenes having at least about 60%, such as about 70%
to about 90% and above, terminal vinylidene content. Compounds of
formula (IV) can be the reaction product of a
hydrocarbyl-substituted succinic anhydride, such as a
polyisobutenyl succinic anhydride (PIBSA), and a polyamine, for
example tetraethylene pentamine (TEPA).
[0039] The presently disclosed dispersants can used in the range of
about 1 wt. % to about 70 wt. %, such as about 5 wt. % to about 50
wt. %, for example about 10 wt. % to about 30 wt. %, relative to
the total weight of the additive composition. In an aspect, the
disclosed aminotriazole compound and dispersant can be present in a
fuel composition at a weight ratio ranging from about 1:5 to about
5:1, such as from about 2:1 to about 1:1.
[0040] In an aspect, the presently disclosed aminotriazoles can
used in the range of about 1 wt. % to about 70 wt. %, such as about
5 wt. % to about 50 wt. %, for example about 10 wt. % to about 30
wt. %, relative to the total weight of the additive
composition.
[0041] In other aspects of the present disclosure, the disclosed
compositions can comprise a fuel soluble carrier. Such carriers can
be of various types, such as liquids or solids, e.g., waxes.
Examples of liquid carriers include, but are not limited to,
mineral oil and oxygenates, such as liquid polyalkoxylated ethers
(also known as polyalkylene glycols or polyalkylene ethers), liquid
polyalkoxylated phenols, liquid polyalkoxylated esters, liquid
polyalkoxylated amines, and mixtures thereof. Examples of the
oxygenate carriers can be found in U.S. Pat. No. 5,752,989, the
description of which carriers is herein incorporated by reference
in its entirety. Additional examples of oxygenate carriers include
alkyl-substituted aryl polyalkoxylates described in U.S. Patent
Publication No. 2003/0131527, published Jul. 17, 2003 to Colucci
et. al., the description of which is herein incorporated by
reference in its entirety.
[0042] In other aspects, compositions of the present application
may not contain a carrier. For example, some compositions of the
present application may not contain mineral oil or oxygenates, such
as those oxygenates described above.
[0043] One or more additional optional additives can be present in
the compositions disclosed herein. For example, the compositions
can contain antifoam agents, dispersants, detergents, antioxidants,
thermal stabilizers, carrier fluids, metal deactivators, dyes,
markers, corrosion inhibitors, biocides, antistatic additives, drag
reducing agents, friction modifiers, demulsifiers, emulsifiers,
dehazers, anti-icing additives, antiknock additives, surfactants,
cetane improvers, corrosion inhibitors, cold flow improvers, pour
point depressants, solvents, demulsifiers, lubricity additives,
extreme pressure agents, viscosity index improvers, seal swell
agents, amine stabilizers, combustion improvers, dispersants,
conductivity improvers, metal deactivators, marker dyes, organic
nitrate ignition accelerators, manganese tricarbonyl compounds, and
mixtures thereof. In some aspects, the fuel additive compositions
described herein can contain about 10 wt. % or less, or in other
aspects, about 5 wt. % or less, based on the total weight of the
additive or fuel composition, of one or more of the above
additives. Similarly, the fuel compositions can contain suitable
amounts of fuel blending components such as methanol, ethanol,
dialkyl ethers, and the like.
[0044] When formulating the presently disclosed compositions, the
disclosed additives can be employed in amounts sufficient to
improve the conductivity properties of a fuel, such as middle
distillate fuel, for example diesel fuel. In some aspects, the
fuels can contain a major amount of a fuel and a minor amount of
the above-described fuel additive composition. In an aspect, fuels
of the present disclosure can comprise, on an active ingredient
basis, an aminotriazole compound as described herein in an amount
ranging from about 1 ppm to about 200 ppm, such as from about 5 ppm
to about 50 ppm. In another aspect, the presently disclosed fuel
compositions can comprise, on an active ingredient basis, a
dispersant as described herein in an amount ranging from about 5 to
about 500 ppm, such as from about 20 ppm to about 200 ppm.
[0045] In aspects where a carrier is employed, the fuel
compositions can contain, on an active ingredients basis, an amount
of the carrier ranging from about 1 mg to about 100 mg of carrier
per kg of fuel, such as about 5 mg to about 50 mg of carrier per kg
of fuel. The active ingredient basis excludes the weight of (i)
unreacted components associated with and remaining in the disclosed
additives as produced and used, and (ii) solvent(s), if any, used
in the manufacture of the disclosed additives either during or
after its formation but before addition of a carrier, if a carrier
is employed.
[0046] The fuel additives of the present disclosure can be blended
into a base fuel individually or in various sub-combinations. In
some embodiments, the additive components of the present disclosure
can be blended into a fuel concurrently using an additive
concentrate, as this takes advantage of the mutual compatibility
and convenience afforded by the combination of ingredients when in
the form of an additive concentrate. Also, use of a concentrate can
reduce blending time and lessen the possibility of blending
errors.
[0047] The fuel compositions of the present disclosure can be
applicable to the operation of both stationary diesel engines
(e.g., engines used in electrical power generation installations,
in pumping stations, etc.) and ambulatory diesel engines (e.g.,
engines used as prime movers in automobiles, trucks, road-grading
equipment, military vehicles, etc.).
[0048] In an aspect, there is provided a method of improving the
conductivity of a fuel comprising: providing a major amount of
fuel, and a minor amount of an additive composition comprising: (a)
a hydrocarbyl-substituted succinimide dispersant, and (b) a
compound of formula (III):
##STR00010##
and tautomers and enantiomers thereof, wherein R.sup.3 is a
hydrocarbyl group having a number average molecular weight ranging
from about 100 to about 5000, and wherein the ratio of (a) to (b)
ranges from about 1:2 to about 2:1. In an aspect, the fuel can
comprise a middle distillate fuel, such as a diesel fuel.
EXAMPLES
[0049] The following examples are illustrative of exemplary
embodiments of the disclosure. In these examples as well as
elsewhere in this application, all parts and percentages are by
weight unless otherwise indicated. It is intended that these
examples are being presented for the purpose of illustration only
and are not intended to limit the scope of the invention disclosed
herein.
Example 1
[0050] A 950 number average molecular weight polybutenyl succinic
anhydride was heated to 95.degree. C. An oil slurry of
aminoguanidine bicarbonate (AGBC) was added over a 45 minute
period. The mixture was heated under vacuum to 160.degree. C. and
held at that temperature for about 6 hours, removing water and
carbon dioxide. The resulting mixture was filtered. It is believed,
without being limited by theory, that the resultant mixture
comprises an aminotriazole as described herein.
[0051] In the following examples, various base diesel fuels were
each combined with a dispersant and an aminotriazole as described
in Table 1 to produce fuel formulations that were evaluated for
fuel conductivity as described below. The dispersant used was a
succinimide formed by the reaction of PIBSA with TEPA on a 1:1 mole
ratio. The aminotriazole used was the aminotriazole mixture
described above,
TABLE-US-00001 TABLE 1 Dispersant Aminotriazole Conductivity (ppmw)
(ppmw) (pS/m) Fuel A 0 0 2 Fuel B 0 60 328 Fuel C 20 40 1013 Fuel D
30 30 691 Fuel E 40 20 525 Fuel F 60 0 121
[0052] Conductivities of the test fuels were evaluated according to
ASTM 2624 using an EMCEE conductivity meter (Model 1152) having a
range of from about 1 to about 2000 picosiemens m.sup.-1 (pS/m).
All conductivity values were measured within a temperature range of
from about 20.degree. C. to about 25.degree. C. All conductivity
measurements are in picosiemens m.sup.-1 (pS/m), also known as CU
or Conductivity Units.
[0053] It was observed that Fuel A (comprising none of the
additives) demonstrated poor conductivity (2 pS/m). Fuel B
(comprising 60 ppm of an aminotriazole) demonstrated a conductivity
of 328 pS/m, and Fuel F (comprising 60 ppm of a dispersant)
demonstrated a conductivity of 121 pS/m.
[0054] However, Fuels C through E (comprising a combination of the
dispersant and aminotriazole) showed unexpected results for fuels
that contain the additive composition, thus illustrating the
synergistic effect of the aminotriazole and dispersant together. In
fact, Fuel C demonstrated over 90% improvement and over 70%
improvement in conductivity values over Fuels F and B,
respectively. The results for Fuels C through E were considered as
being unexpected because, for example, each compound used alone
showed less benefit than the combination. In other words, as seen
from the results, Fuels C through E (each comprising a combination
of aminotriazole and dispersant) surprisingly demonstrated much
higher conductivity values as compared to Fuels B and F, each
comprising the aminotriazole and dispersant alone, respectively.
Accordingly, it is believed that the additive composition as
described herein can be effective for improving the conductivity
properties of fuels.
[0055] It is noted that, as used in this specification and the
appended claims, the singular forms "a," "an," and "the," include
plural referents unless expressly and unequivocally limited to one
referent. Thus, for example, reference to "a dispersant" includes
two or more different dispersants. As used herein, the term
"include" and its grammatical variants are intended to be
non-limiting, such that recitation of items in a list is not to the
exclusion of other like items that can be substituted or added to
the listed items
[0056] For the purposes of this specification and appended claims,
unless otherwise indicated, all numbers expressing quantities,
percentages or proportions, and other numerical values used in the
specification and claims, are to be understood as being modified in
all instances by the term "about." Accordingly, unless indicated to
the contrary, the numerical parameters set forth in the following
specification and attached claims are approximations that can vary
depending upon the desired properties sought to be obtained by the
present disclosure. At the very least, and not as an attempt to
limit the application of the doctrine of equivalents to the scope
of the claims, each numerical parameter should at least be
construed in light of the number of reported significant digits and
by applying ordinary rounding techniques.
[0057] While particular embodiments have been described,
alternatives, modifications, variations, improvements, and
substantial equivalents that are or can be presently unforeseen can
arise to applicants or others skilled in the art. Accordingly, the
appended claims as filed and as they can be amended are intended to
embrace all such alternatives, modifications variations,
improvements, and substantial equivalents.
* * * * *