U.S. patent application number 13/583024 was filed with the patent office on 2013-02-07 for fuel composition comprising detergent and quanternary ammonium salt additive.
This patent application is currently assigned to INNOSPEC LIMITED. The applicant listed for this patent is Vincent Burgess, Jacqueline Reid. Invention is credited to Vincent Burgess, Jacqueline Reid.
Application Number | 20130031828 13/583024 |
Document ID | / |
Family ID | 42136760 |
Filed Date | 2013-02-07 |
United States Patent
Application |
20130031828 |
Kind Code |
A1 |
Reid; Jacqueline ; et
al. |
February 7, 2013 |
FUEL COMPOSITION COMPRISING DETERGENT AND QUANTERNARY AMMONIUM SALT
ADDITIVE
Abstract
A method of reducing deposits in a diesel engine, the method
comprising combusting in the engine a diesel fuel composition
comprising a detergent additive which is not a quaternary ammonium
salt or a Mannich reaction product; and a quaternary ammonium salt
additive comprising the reaction product of nitrogen containing
species having at least one tertiary amine group and a quaternizing
agent; wherein the nitrogen containing species is selected from:
(i) the reaction product of a hydrocarbyl-substituted acylating
agent and a compound comprising at least one tertiary amine group
and a primary amine, secondary amine or alcohol group; (ii) a
Mannich reaction product comprising a tertiary amine group; and (v)
a polyalkylene substituted amine having at least one tertiary amine
group.
Inventors: |
Reid; Jacqueline; (Cymau,
GB) ; Burgess; Vincent; (Ellesmere Port, GB) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Reid; Jacqueline
Burgess; Vincent |
Cymau
Ellesmere Port |
|
GB
GB |
|
|
Assignee: |
INNOSPEC LIMITED
Ellesmere Port, Cheshire
GB
|
Family ID: |
42136760 |
Appl. No.: |
13/583024 |
Filed: |
March 10, 2011 |
PCT Filed: |
March 10, 2011 |
PCT NO: |
PCT/GB2011/050479 |
371 Date: |
October 1, 2012 |
Current U.S.
Class: |
44/386 |
Current CPC
Class: |
C10L 1/189 20130101;
C10L 2200/029 20130101; C10L 10/04 20130101; C10L 1/232 20130101;
C10L 1/18 20130101; C10L 2200/0259 20130101; C10L 1/22 20130101;
C10L 1/1824 20130101; C10L 2200/0446 20130101; C10L 1/1817
20130101; C10L 1/226 20130101; C10L 1/2387 20130101; C10L 2270/026
20130101; C10L 1/1881 20130101; C10L 10/06 20130101; C10L 1/2383
20130101; C10L 1/221 20130101; C10L 2250/04 20130101 |
Class at
Publication: |
44/386 |
International
Class: |
C10L 1/22 20060101
C10L001/22 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 10, 2010 |
GB |
1003973.3 |
Claims
1. A method of reducing deposits in a diesel engine, the method
comprising, combusting in the engine a diesel fuel composition
comprising a detergent additive which is not a quaternary ammonium
salt or a Mannich reaction product; and a quaternary ammonium salt
additive comprising the reaction product of nitrogen containing
species having at least one tertiary amine group and a quaternizing
agent; *herein the nitrogen containing species is selected from:
(i) the reaction product of a hydrocarbyl-substituted acylating
agent and a compound comprising at least one tertiary amine group
and a primary amine, secondary amine or alcohol group; (ii) a
Mannich reaction product comprising a tertiary amine group; and
(iii) a polyalkylene substituted amine having at least one tertiary
amine group,
2. The method according to claim 1 in which formation of deposits
is inhibited or prevented to provide a keep clean performance.
3. The method according to claim 1 in which existing deposits are
removed to provide a clean up performance.
4. The method according to claim 1 wherein the quaternizing agent
is selected from the group consisting of dialkyl sulphates; an
ester of a carboxylic acid; alkyl halides; benzyl halides;
hydrocarbyl substituted carbonates; and hydrocarbyl epoxides.
5. The method according to claim 1 wherein the nitrogen containing
species comprises a compound formed by the reaction of a
hydrocarbyl-substituted acylating agent and an amine of formula (I)
or (II): ##STR00015## wherein R.sup.2 and R.sup.3 are the same or
different alkyl groups having from 1 to 22 carbon atoms; X is an
alkylene group having from 1 to 20 carbon atoms; n is from 0 to 20;
m is from 1 to 5; and R.sup.4 is hydrogen or a C.sub.1 to C.sub.22
alkyl group.
6. The method according to claim 1 wherein the quaternizing agent
comprises a compound of formula (III): ##STR00016## wherein R is a
substituted alkyl, alkenyl, aryl or alkylaryl group; and R.sup.1 is
a C.sub.1 to C.sub.22 alkyl, aryl or alkylaryl group.
7. The method according to claim 1 wherein the detergent additive
is selected from one or more of: (a) the reaction product of a
carboxylic acid-derived acylating agent and an amine; (b) the
reaction product of a carboxylic acid-derived acylating agent and
hydrazine; (c) a salt formed by the reaction of a carboxylic acid
with di-n-butylamine or tri-n-butylamine; (d) the reaction product
of a hydrocarbyl-substituted dicarboxylic acid or abhydride and an
amine compound or salt which product comprises at least one amino
triazole group; and (e) a polyaromatic detergent additive.
8. The method according to claim 7 wherein the detergent additive
comprises component (a) and is made by reacting a
poly(isobutene)-substituted succinic acid-derived acylating agent
(e.g., anhydride, acid, ester, etc.) wherein the poly(isobutene)
substituent has between about 12 to about 200 carbon atoms with a
mixture of ethylene polyamines having 3 to about 9 amino nitrogen
atoms per ethylene polyamine and about 1 to about 8 ethylene
groups.
9. The method according to claim 7 wherein the detergent additive
comprises component (b) and is the reaction product between a
hydrocarbyl-substituted succinic acid or anhydride and
hydrazine.
10. The method according to claim 7 wherein the detergent additive
comprises component (c) and is the di-n-butylamine or
tri-n-butylamine salt of a fatty acid of the formula
[R'(COOH).sub.x].sub.y', where each R' is a independently a
hydrocarbon group of between 2 and 45 carbon atoms, and x is an
integer between 1 and 4.
11. The method according to claim 7 wherein the detergent additive
comprises component (d) and is and is the reaction product of an
amine compound having the formula: ##STR00017## and a hydrocarbyl
carbonyl compound of the formula: ##STR00018## wherein R is
selected from the group consisting of a hydrogen and a hydrocarbyl
group containing from about 1 to about 15 carbon atoms; R.sup.1 is
selected from the group consisting of hydrogen and a hydrocarbyl
group containing from about 1 to about 20 carbon atoms; and R.sup.2
is a hydrocarbyl group having a number average molecular weight
ranging from about 100 to about 5000.
12. The method according to claim 7 wherein the detergent additive
comprises component (e) and comprises at least one compound of
formula (IV) and/or formula (V): ##STR00019## wherein each Ar
independently represents an aromatic moiety having 0 to 3
substituents selected from the group consisting of alkyl, alkoxy,
alkoxyalkyl, aryloxy, aryloxyalkyl, hydroxy, hydroxyalkyl, halo and
combinations thereof; each L is independently a linking moiety
comprising a carbon-carbon single bond or a linking group; each Y
is independently --OR.sup.1'' or a moiety of the formula
H(O(CR.sup.1.sub.2).sub.n).sub.yX--, wherein X is selected from the
group consisting of (CR.sup.1.sub.2).sub.2, O and S: R.sup.1 and
R.sup.1' are each independently selected from H, C.sub.1 to C.sub.6
alkyl and aryl; R.sup.1'' is selected from C.sub.1 to C.sub.100
alkyl and aryl; z is 1 to 10; n is 0 to 10 when X is
(CR.sup.1.sub.2).sub.2, and 2 to 10 when X is O or S; and y is 1 to
30; each a is independently 0 to 3, with the proviso that at least
one Ar moiety bears at least one group Y; and m is 1 to 100;
##STR00020## wherein each Ar' independently represents an aromatic
moiety having 0 to 3 substituents selected from the group
consisting of alkyl, alkoxy, alkoxyalkyl, hydroxy, hydroxyalkyl,
acyloxy, acyloxyalkyl, acyloxyalkoxy, aryloxy, aryloxyalkyl,
aryloxyalkoxy, halo and combinations thereof; each L' is
independently a linking moiety comprising a carbon-carbon single
bond or linking group; each Y' is independently a moiety of the
formula ZO-- or Z(O(CR.sup.2.sub.2).sub.n').sub.y'X'--, wherein X'
is selected from the group consisting of (CR.sup.2'.sub.2).sub.z',
O and S; R.sup.2 and R.sup.2' are each independently selected from
H, C.sub.1 to C.sub.6 alkyl and aryl z' is 1 to 10; n' is 0 to 10
when X' is (CR.sup.2'.sub.2).sub.z, and 2 to 10 when X' is O or S;
y is 1 to 30; Z is H, an acyl group, a polyacyl group, a lactone
ester group, an acid ester group, an alkyl group or an aryl group;
and each a' is independently 0 to 3, with the proviso that at least
one Ar' moiety bears at least one group Y' in which Z is not H; and
m' is 1 to 100.
13. A diesel fuel composition as defined in claim 1.
14. The method according to claim 1 wherein the diesel engine has a
high pressure fuel system.
15. (canceled)
16. An additive composition comprising a detergent additive which
is not a quaternary ammonium salt or a Mannich reaction product;
and a quaternary ammonium salt additive comprising the reaction
product of nitrogen containing species having at least one tertiary
amine group and a quaternizing agent; wherein the nitrogen
containing species is selected from: (i) the reaction product of a
hydrocarbyl-substituted acylating agent and a compound comprising
at least one tertiary amine group and a primary amine, secondary
amine or alcohol group; (ii) a Mannich reaction product comprising
a tertiary amine group; and (iii) a polyalkylene substituted amine
having at least one tertiary amine group.
17. The method according to any preceding claim 1 wherein the
quaternizing agent is combined with an acid or mixtures
thereof.
18. The method according to claim 7 wherein R.sup.2 is a
hydrocarbyl group having a number average molecular weight ranging
from about 200 to 3000.
Description
[0001] The present invention relates to fuel compositions and
additives thereto. In particular the invention relates to additives
for diesel fuel compositions, especially those suitable for use in
modern diesel engines with high pressure fuel systems.
[0002] Due to consumer demand and legislation, diesel engines have
in recent years become much more energy efficient, show improved
performance and have reduced emissions.
[0003] These improvements in performance and emissions have been
brought about by improvements in the combustion process. To achieve
the fuel atomisation necessary for this improved combustion, fuel
injection equipment has been developed which uses higher injection
pressures and reduced fuel injector nozzle hole diameters. The fuel
pressure at the injection nozzle is now commonly in excess of 1500
bar (1.5.times.10.sup.8 Pa). To achieve these pressures the work
that must be done on the fuel also increases the temperature of the
fuel. These high pressures and temperatures can cause degradation
of the fuel.
[0004] Diesel engines having high pressure fuel systems can include
but are not limited to heavy duty diesel engines and smaller
passenger car type diesel engines. Heavy duty diesel engines can
include very powerful engines such as the MTU series 4000 diesel
having 20 cylinder variants designed primarily for ships and
power-generation with power output up to 4300 kW or engines such as
the Renault dXi 7 having 6 cylinders and a power output around 240
kW. A typical passenger car diesel engine is the Peugeot DW10
having 4 cylinders and power output of 100 kW or less depending on
the variant.
[0005] In all of the diesel engines relating to this invention, a
common feature is a high pressure fuel system. Typically pressures
in excess of 1350 bar (1.35.times.10.sup.8 Pa) are used but often
pressures of up to 2000 bar (2.times.10.sup.8 Pa) or more may
exist.
[0006] Two non-limiting examples of such high pressure fuel systems
are: the common rail injection system, in which the fuel is
compressed utilizing a high-pressure pump that supplies it to the
fuel injection valves through a common rail; and the unit injection
system which integrates the high-pressure pump and fuel injection
valve in one assembly, achieving the highest possible injection
pressures exceeding 2000 bar (2.times.10.sup.8 Pa). In both
systems, in pressurising the fuel, the fuel gets hot, often to
temperatures around 100.degree. C., or above.
[0007] In common rail systems, the fuel is stored at high pressure
in the central accumulator rail or separate accumulators prior to
being delivered to the injectors. Often, some of the heated fuel is
returned to the low pressure side of the fuel system or returned to
the fuel tank. In unit injection systems the fuel is compressed
within the injector in order to generate the high injection
pressures. This in turn increases the temperature of the fuel.
[0008] In both systems, fuel is present in the injector body prior
to injection where it is heated further due to heat from the
combustion chamber. The temperature of the fuel at the tip of the
injector can be as high as 250-350.degree. C.
[0009] Thus the fuel is stressed at pressures from 1350 bar
(1.35.times.10.sup.8 Pa) to over 2000 bar (2.times.10.sup.8 Pa) and
temperatures from around 100.degree. C. to 350.degree. C. prior to
injection, sometimes being recirculated back within the fuel system
thus increasing the time for which the fuel experiences these
conditions.
[0010] A common problem with diesel engines is fouling of the
injector, particularly the injector body, and the injector nozzle.
Fouling may also occur in the fuel filter. Injector nozzle fouling
occurs when the nozzle becomes blocked with deposits from the
diesel fuel. Fouling of fuel filters may be related to the
recirculation of fuel back to the fuel tank. Deposits increase with
degradation of the fuel. Deposits may take the form of carbonaceous
coke-like residues or sticky or gum-like residues. Diesel fuels
become more and more unstable the more they are heated,
particularly if heated under pressure. Thus diesel engines having
high pressure fuel systems may cause increased fuel
degradation.
[0011] The problem of injector fouling may occur when using any
type of diesel fuels. However, some fuels may be particularly prone
to cause fouling or fouling may occur more quickly when these fuels
are used. For example, fuels containing biodiesel have been found
to produce injector fouling more readily. Diesel fuels containing
metallic species may also lead to increased deposits. Metallic
species may be deliberately added to a fuel in additive
compositions or may be present as contaminant species.
Contamination occurs if metallic species from fuel distribution
systems, vehicle distribution systems, vehicle fuel systems, other
metallic components and lubricating oils become dissolved or
dispersed in fuel.
[0012] Transition metals in particular cause increased deposits,
especially copper and zinc species. These may be typically present
at levels from a few ppb (parts per billion) up to 50 ppm, but it
is believed that levels likely to cause problems are from 0.1 to 50
ppm, for example 0.1 to 10 ppm.
[0013] When injectors become blocked or partially blocked, the
delivery of fuel is less efficient and there is poor mixing of the
fuel with the air. Over time this leads to a loss in power of the
engine, increased exhaust emissions and poor fuel economy.
[0014] As the size of the injector nozzle hole is reduced, the
relative impact of deposit build up becomes more significant. By
simple arithmetic a 5 .mu.m layer of deposit within a 500 .mu.m
hole reduces the flow area by 4% whereas the same 5 .mu.m layer of
deposit in a 200 .mu.m hole reduces the flow area by 9.8%.
[0015] At present, nitrogen-containing detergents may be added to
diesel fuel to reduce coking. Typical nitrogen-containing
detergents are those formed by the reaction of a
polyisobutylene-substituted succinic acid derivative with a
polyalkylene polyamine. However, newer engines including finer
injector nozzles are more sensitive and current diesel fuels may
not be suitable for use with the new engines incorporating these
smaller nozzle holes.
[0016] The present inventor has developed diesel fuel compositions
which when used in diesel engines having high pressure fuel systems
provide improved performance compared with diesel fuel compositions
of the prior art.
[0017] It is advantageous to provide a diesel fuel composition
which prevents or reduces the occurrence of depositis in a diesel
engine. Such fuel compositions may be considered to perform a "keep
clean" function i.e. they prevent or inhibit fouling.
[0018] However it would also be desirable to provide a diesel fuel
composition which would help clean up deposits that have already
formed in an engine, in particular deposits which have formed on
the injectors. Such a fuel composition which when combusted in a
diesel engine removes deposits therefrom thus effecting the
"clean-up" of an already fouled engine.
[0019] As with "keep clean" properties, "clean-up" of a fouled
engine may provide significant advantages. For example, superior
clean up may lead to an increase in power and/or an increase in
fuel economy. In addition removal of deposits from an engine, in
particular from injectors may lead to an increase in interval time
before injector maintenance or replacement is necessary thus
reducing maintenance costs.
[0020] Although for the reasons mentioned above deposits on
injectors is a particular problem found in modern diesel engines
with high pressure fuels systems, it is desirable to provide a
diesel fuel composition which also provides effective detergency in
older traditional diesel engines such that a single fuel supplied
at the pumps can be used in engines of all types.
[0021] It is also desirable that fuel compositions reduce the
fouling of vehicle fuel filters. It would be useful to provide
compositions that prevent or inhibit the occurrence of fuel filter
deposits i.e, provide a "keep clean" function. It would be useful
to provide compositions that remove existing deposits from fuel
filter deposits i.e. provide a "clean up" function. Compositions
able to provide both of these functions would be especially
useful.
[0022] According to a first aspect of the present invention there
is provided a method of reducing deposits in a diesel engine, the
method comprising combusting in the engine a diesel fuel
composition comprising a detergent additive which is not a
quaternary ammonium salt or a Mannich reaction product; and a
quaternary ammonium salt additive comprising the reaction product
of nitrogen containing species having at least one tertiary amine
group and a quaternizing agent; wherein the nitrogen containing
species is selected from: [0023] (i) the reaction product of a
hydrocarbyl-substituted acylating agent and a compound comprising
at least one tertiary amine group and a primary amine, secondary
amine or alcohol group; [0024] (ii) a Mannich reaction product
comprising a tertiary amine group; and [0025] (iii) a polyalkylene
substituted amine having at least one tertiary amine group.
[0026] Examples of quaternary ammonium salt and methods for
preparing the same are described in the following patents, which
are hereby incorporated by reference, U.S. Pat. No. 4,253,980, U.S.
Pat. No. 3,778,371, U.S. Pat. No. 4,171,959, U.S. Pat. No.
4,326,973, U.S. Pat. No. 4,338,206, and U.S. Pat. No.
5,254,138.
[0027] Component (i) may be regarded as the reaction product of a
hydrocarbyl-substituted acylating agent and a compound having an
oxygen or nitrogen atom capable of condensing with said acylating
agent and further having a tertiary amino group.
[0028] When the nitrogen containing species includes component (i),
the hydrocarbyl substituted acylating agent is preferably a mono-or
polycarboxylic acid (or reactive equivalent thereof) for example a
substituted succinic, phthalic or propionic acid.
[0029] The hydrocarbyl substituent in such acylating agents
preferably comprises at least 8, more preferably at least 12, for
example 30 or 50 carbon atoms. It may comprise up to about 200
carbon atoms. Preferably the hydrocarbyl substituent of the
acylating agent has a number average molecular weight (Mn) of
between 170 to 2800, for example from 250 to 1500, preferably from
500 to 1500 and more preferably 500 to 1100. An Mn of 700 to 1300
is especially preferred, for example from 700 to 1000.
[0030] Illustrative of hydrocarbyl substituent based groups
containing at least eight carbon atoms are n-octyl, n-decyl,
n-dodecyl, tetrapropenyl, n-octadecyl, oleyl, chloroctadecyl,
triicontanyl, etc. The hydrocarbyl based substituents may be made
from homo- or interpolymers (e.g. copolymers, terpolymers) of mono-
and di-olefins having 2 to 10 carbon atoms, for example ethylene,
propylene, butane-1, isobutene, butadiene, isoprene, 1-hexene,
1-octene, etc. Preferably these olefins are 1-monoolefins. The
hydrocarbyl substituent may also be derived from the halogenated
(e.g. chlorinated or brominated) analogs of such homo- or
interpolymers. Alternatively the substituent may be made from other
sources, for example monomeric high molecular weight alkenes (e.g.
1-tetra-contene) and chlorinated analogs and hydrochlorinated
analogs thereof, aliphatic petroleum fractions, for example
paraffin waxes and cracked and chlorinated analogs and
hydrochlorinated analogs thereof, white oils, synthetic alkenes for
example produced by the Ziegler-Natta process (e.g. poly(ethylene)
greases) and other sources known to those skilled in the art. Any
unsaturation in the substituent may if desired be reduced or
eliminated by hydrogenation according to procedures known in the
art.
[0031] The term "hydrocarbyl" as used herein denotes a group having
a carbon atom directly attached to the remainder of the molecule
and having a predominantly aliphatic hydrocarbon character.
Suitable hydrocarbyl based groups may contain non-hydrocarbon
moieties. For example they may contain up to one non-hydrocarbyl
group for every ten carbon atoms provided this non-hydrocarbyl
group does not significantly alter the predominantly hydrocarbon
character of the group. Those skilled in the art will be aware of
such groups, which include for example hydroxyl, halo (especially
chloro and fluoro), alkoxyl, alkyl mercapto, alkyl sulphoxy, etc.
Preferred hydrocarbyl based substituents are purely aliphatic
hydrocarbon in character and do not contain such groups.
[0032] The hydrocarbyl-based substituents are preferably
predominantly saturated, that is, they contain no more than one
carbon-to-carbon unsaturated bond for every ten carbon-to-carbon
single bonds present. Most preferably they contain no more than one
carbon-to-carbon non-aromatic unsaturated bond for every 50
carbon-to-carbon bonds present.
[0033] In some preferred embodiments, the hydrocarbyl-based
substituents are poly-(isobutene)s known in the art. Thus in
especially preferred embodiments the hydrocarbyl substituted
acylating agent is a polyisobutenyl substituted succinic
anhydride.
[0034] The preparation of polyisobutenyl substituted succinic
anhydrides (PIBSA) is documented in the art. Suitable processes
include thermally reacting polyisobutenes with maleic anhydride
(see for example U.S. Pat. No. 3,361,673 and U.S. Pat. No.
3,018,250), and reacting a halogenated, in particular a
chlorinated, polyisobutene (PIB) with maleic anhydride (see for
example U.S. Pat. No. 3,172,892). Alternatively, the polyisobutenyl
succinic anhydride can be prepared by mixing the polyolefin with
maleic anhydride and passing chlorine through the mixture (see for
example GB-A-949,981).
[0035] Conventional polyisobutenes and so-called "highly-reactive"
polyisobutenes are suitable for use in the invention. Highly
reactive polyisobutenes in this context are defined as
polyisobutenes wherein at least 50%, preferably 70% or more, of the
terminal olefinic double bonds are of the vinylidene type as
described in EP0565285. Particularly preferred polyisobutenes are
those having more than 80 mol % and up to 100% of terminal
vinylidene groups such as those described in EP1344785.
[0036] Other preferred hydrocarbyl groups include those having an
internal olefin for example as described in the applicant's
published application WO2007/015080.
[0037] An internal olefin as used herein means any olefin
containing predominantly a non-alpha double bond, that is a beta or
higher olefin. Preferably such materials are substantially
completely beta or higher olefins, for example containing less than
10% by weight alpha olefin, more preferably less than 5% by weight
or less than 2% by weight. Typical internal olefins include Neodene
1518IO available from Shell.
[0038] Internal olefins are sometimes known as isomerised olefins
and can be prepared from alpha olefins by a process of
isomerisation known in the art, or are available from other
sources. The fact that they are also known as internal olefins
reflects that they do not necessarily have to be prepared by
isomerisation.
[0039] Examples of the nitrogen or oxygen containing compounds
capable of condensing with the acylating agent and further having a
tertiary amino group can include but are not limited to:
N,N-dimethylaminopropylamine, N,N-diethylaminopropylamine,
N,N-dimethylamino ethylamine. The nitrogen or oxygen containing
compounds capable of condensing with the acylating agent and
further having a tertiary amino group can further include amino
alkyl substituted heterocyclic compounds such as
1-(3-aminopropyl)imidazole and 4-(3-aminopropyl)morpholine,
1-(2-aminoethyl)piperidine, 3,3-diamino-N-methyldipropylamine, and
3'3-aminobis(N,N-dimethylpropylamine). Other types of nitrogen or
oxygen containing compounds capable of condensing with the
acylating agent and having a tertiary amino group include
alkanolamines including but not limited to triethanolamine,
trimethanolamine, N,N-dimethylaminopropanol,
N,N-dimethylaminoethanol, N,N-diethylaminopropanol,
N,N-diethylaminoethanol, N,N-diethylaminobutanol,
N,N,N-tris(hydroxyethyl)amine, N,N,N-tris(hydroxymethyl)amine,
N,N,N-tris(aminoethyl)amine, N,N-dibutylaminopropylamine and
N,N,N'-trimethyl-N'-hydroxyethyl-bisaminoethylether;
N,N-bis(3-dimethylaminopropyl)-N-isopropanolamine;
N-(3-dimethylaminopropyl)-N,N-diisopropanolamine;
N'-(3-(dimethylamino)propyl)-N,N-dimethyl 1,3-propanediamine;
2-(2-dimethylaminoethoxy)ethanol, and
N,N,N'-trimethylaminoethylethanolamine.
[0040] In some preferred embodiments component (i) comprises a
compound formed by the reaction of a hydrocarbyl-substituted
acylating agent and an amine of formula (I) or (II):
##STR00001##
wherein R.sup.2 and R.sup.3 are the same or different alkyl groups
having from 1 to 22 carbon atoms; X is an alkylene group having
from 1 to 20 carbon atoms; n is from 0 to 20; m is from 1 to 5; and
R.sup.4 is hydrogen or a C.sub.1 to C.sub.22 alkyl group.
[0041] When a compound of formula (I) is used, R.sup.4 is
preferably hydrogen or a C.sub.1 to C.sub.16 alkyl group,
preferably a C.sub.1 to C.sub.10 alkyl group, more preferably a
C.sub.1 to C.sub.6 alkyl group. More preferably R.sup.4 is selected
from hydrogen, methyl, ethyl, propyl, butyl and isomers thereof.
Most preferably R.sup.4 is hydrogen.
[0042] When a compound of formula (II) is used, m is preferably 2
or 3, most preferably 2; n is preferably from 0 to 15, preferably 0
to 10, more preferably from 0 to 5. Most preferably n is 0 and the
compound of formula (II) is an alcohol.
[0043] Preferably the hydrocarbyl substituted acylating agent is
reacted with a diamine compound of formula (I).
[0044] R.sup.2 and R.sup.3 may each independently be a C.sub.1 to
C.sub.16 alkyl group, preferably a C.sub.1 to C.sub.10 alkyl group.
R.sup.2and R.sup.3 may independently be methyl, ethyl, propyl,
butyl, pentyl, hexyl, heptyl, octyl, or an isomer of any of these.
Preferably R.sup.2 and R.sup.3 is each independently C.sub.1 to
C.sub.4 alkyl. Preferably R.sup.2 is methyl. Preferably R.sup.3 is
methyl.
[0045] X is preferably an alkylene group having 1 to 16 carbon
atoms, preferably 1 to 12 carbon atoms, more preferably 1 to 8
carbon atoms, for example 2 to 6 carbon atoms or 2 to 5 carbon
atoms. Most preferably X is an ethylene, propylene or butylene
group, especially a propylene group.
[0046] The preparation of suitable quaternary ammonium salt
additives in which the nitrogen-containing species includes
component (i) is described in WO 2006/135881.
[0047] In preferred embodiments component (i) is the reaction
product of a hydrocarbyl-substituted succinic acid derivative
(suitably a polyisobutylene-substituted succinic anhydride) and an
alcohol or amine also including a tertiary amine group.
[0048] In some embodiments when the succinic acid derivative is
reacted with an amine (also including a tertiary amine group) under
conditions to form a succinimide.
[0049] In an alternative embodiment the reaction of the succinic
acid derivative and the amine may be carried out under conditions
which result in the formulation of a succinamide i.e., a compound
including an amide group and a carboxylic acid group.
[0050] In embodiments in which an alcohol (also including a
tertiary amine group) is reacted with the succinic acid derivative
an ester results. This ester molecule also includes a free
carboxylic acid group.
[0051] Thus in some embodiments component (i) may be the reaction
product of a succinic acid derivative and an amine or alcohol which
is an ester or an amide and which also includes a further unreacted
carboxylic acid group.
[0052] Component (ii) is a Mannich reaction product having a
tertiary amine. The preparation of quaternary ammonium salts formed
from nitrogen-containing species including component (ii) is
described in US 2008/0052985.
[0053] The Mannich reaction product having a tertiary amine group
is prepared from the reaction of a hydrocarbyl-substituted phenol,
an aldehyde and an amine.
[0054] The hydrocarbyl substituent of the hydrocarbyl substituted
phenol can have 6 to 400 carbon atoms, suitably 30 to 180 carbon
atoms, for example 10 or 40 to 110 carbon atoms. This hydrocarbyl
substituent can be derived from an olefin or a polyolefin. Useful
olefins include alpha-olefins, such as 1-decene, which are
commercially available.
[0055] The polyolefins which can form the hydrocarbyl substituent
casn be prepared by polymerizing olefin monomers by well known
polymerization methods and are also commercially available.
[0056] Some preferred polyolefins include polyisobutylenes having a
number average molecular weight of 400 to 3000, in another instance
of 400 to 2500, and in a further instance of 400 or 500 to
1500.
[0057] The hydrocarbyl-substituted phenol can be prepared by
alkylating phenol with an olefin or polyolefin described above,
such as, a polyisobutylene or polypropylene, using well-known
alkylation methods.
[0058] In some embodiments the phenol may include a lower molecular
weight alkyl substituent for example a phenol which carries one or
more alkyl chains having a total of less 28 carbon atoms,
preferably less than 24 carbon atoms, more preferably less than 20
carbon atoms, preferably less than 18 carbon atoms, preferably less
than 16 carbon atoms and most preferably less than 14 carbon
atoms.
[0059] A monoalkyl phenol may be preferred, suitably having from 4
to 20 carbons atoms, preferably 6 to 18, more preferably 8 to 16,
especially 10 to 14 carbon atoms, for example a phenol having a C12
alkyl substituent.
[0060] The aldehyde used to form the Mannich detergent can have 1
to 10 carbon atoms, and is generally formaldehyde or a reactive
equivalent thereof such as formalin or paraformaldehyde.
[0061] The amine used to form the Mannich detergent can be a
monoamine or a polyamine.
[0062] Examples of monoamines include but are not limited to
ethylamine, dimethylamine, diethylamine, n-butylamine,
dibutylamine, allylamine, isobutylamine, cocoamine, stearylamine,
laurylamine, methyllaurylamine, oleylamine, N-methyl-octylamine,
dodecylamine, diethanolamine, morpholine, and octadecylamine.
[0063] Suitable polyamines may be selected from any compound
including two or more amine groups. Suitable polyamines include
polyalkylene polyamines, for example in which the alkylene
component has 1 to 6, preferably 1 to 4, most preferably 2 to 3
carbon atoms. Preferred polyamines are polyethylene polyamines.
[0064] The polyamine has 2 to 15 nitrogen atoms, preferably 2 to 10
nitrogen atoms, more preferably 2 to 8 nitrogen atoms.
[0065] In especially preferred embodiments the amine used to form
the Mannich detergent comprises a diamine. Suitably it includes a
primary or secondary amine which takes part in the Mannich reaction
and in addition a tertiary amine.
[0066] In preferred embodiments component (ii) comprises the
product directly obtained from a Mannich reaction and comprising a
tertiary amine. For example the amine may comprise a single primary
or secondary amine which when reacted in the Mannich reaction forms
a tertiary amine which is capable of being quaternised.
Alternatively the amine may comprise a primary or secondary amine
capable of taking part in the Mannich reaction and also a tertiary
amine capable of being quaternised. However component (ii) may
comprise a compound which has been obtained from a Mannich reaction
and subsequently reacted to form a tertiary amine, for example a
Mannich reaction may yield a secondary amine which is then
alkylated to a tertiary amine.
[0067] The preparation of quaternary ammonium salt additives in
which the nitrogen-containing species includes component (iii) is
described for example in US 2008/0113890.
[0068] The polyalkene-substituted amines having at least one
tertiary amino group of the present invention may be derived from
an olefin polymer and an amine, for example ammonia, momoamines,
polyamines or mixtures thereof. They may be prepared by a variety
of methods such as those described and referred to in US
2008/0113890.
[0069] Suitable preparation methods include, but are not limited
to: reacting a halogenated olefin polymer with an amine; reacting a
hydroformylated olefin with a polyamine and hydrogenating the
reaction product; converting a polyalkene into the corresponding
epoxide and converting the epoxide into the polyalkene substituted
amine by reductive animation; hydrogenation of a
.beta.-aminonitrile; and hydroformylating an polybutene or
polyisobutylene in the presence of a catalyst, CO and H.sub.2 at
elevated pressure and temperatures.
[0070] The olefin monomers from which the olefin polymers are
derived include polymerizable olefin monomers characterised by the
presence of one or more ethylenically unsaturated groups for
example ethylene, propylene, 1-butene, isobutene, 1-octene,
1,3-butadiene and isoprene.
[0071] The olefin monomers are usually polymerizable terminal
olefins. However, polymerizable internal olefin monomers can also
be used to form the polyalkenes.
[0072] Examples of terminal and internal olefin monomers, which can
be used to prepare the polyalkenes according to conventional,
well-known polymerization techniques include: ethylene; propylene;
butenes, including 1-butene, 2-butene and isobutylene; 1-pentene;
1-hexene; 1-heptene; 1-octene; 1-nonene; 1-decene; 2-pentene;
propylene-tetramer; diisobutylene; isobutylene trimer;
1,2-butadiene; 1,3-butadiene; 1,2-pentadiene; 1,3-pentadiene;
1,4-pentadiene; isoprene; 1,5-hexadiene;
2-methyl-5-propyl-1-hexene; 3-pentene; 4-octene; and
3,3-dimethyl-1-pentene.
[0073] Suitably the polyalkene substituent of the
polyalkene-substituted amine is derived from a polyisobutylene.
[0074] The amines that can be used to make the
polyalkene-substituted amine include ammonia, monoamines,
polyamines, or mixtures thereof, including mixtures of different
monoamines, mixtures of different polyamines, and mixtures of
monoamines and polyamines (which include diamines). The amines
include aliphatic, aromatic, heterocyclic and carbocylic
amines.
[0075] The monomers and polyamines suitably include at least one
primary or secondary amine group.
[0076] Suitable monoamines are generally substituted with a
hydrocarbyl group having 1 to about 50 carbon atoms, preferably 1
to 30 carbon atoms. Saturated aliphatic hydrocarbon radicals are
particularly preferred.
[0077] Examples of suitable monoamines include methylamine,
ethylamine, diethylamine, 2-ethylhexylamine,
di-(2-ethylhexyl)amine, n-butylamine, di-n-butylamine, allylamine,
isobutylamine, cocoamine, stearylamine, laurylamine,
methyllaurylamine and oleylamine.
[0078] Aromatic monoamines include those monoamines wherein a
carbon atom of the aromatic ring structure is attached directly to
the amine nitrogen. Examples of aromatic monoamines include
aniline, di(para-methylphenyl)amine, naphthylamine, and
N-(n-butyl)aniline.
[0079] Examples of aliphatic substituted,
cycloaliphatic-substituted, and heterocyclic-substituted aromatic
monoamines include: para-dodecylaniline, cyclohexyl-substituted
naphthylamine, and thienyl-substituted aniline respectively.
[0080] Hydroxy amines are also included in the class of useful
monoamines. Examples of hydroxyl-substituted monoamines include
ethanolamine, di-3-propanolamine, 4-hydroxybutylamine;
diethanolamine, and N-methyl-2-hydroxypropylamine.
[0081] The amine of the polyalkene-substituted amine can be a
polyamine. The polyamine may be aliphatic, cycloaliphatic,
heterocyclic or aromatic.
[0082] Examples of suitable polyamines include alkylene polyamines,
hydroxy containing polyamines, arylpolyamines, and heterocyclic
polyamines.
[0083] Ethylene polyamines, are especially useful for reasons of
cost and effectiveness. Suitable ethylene polyamines are described
in relation to the first aspect.
[0084] Suitable hydroxy containing polyamines include hydroxyalkyl
alkylene polyamines having one o more hydroxyalkyl substituents on
the nitrogen atoms and can be prepared by reacting
alkylenepolyamines with one or more alkylene oxides. Examples of
suitable hydroxyalkyl-substituted polyamines include:
N-(2-hydroxyethyl)ethylene diamine, N,N-bis(2-hydroxyethyl)ethylene
diamine, 1-(2-hydroxyethyl) piperazine,
monohydroxypropl-substituted diethylene triamine,
dihydroxypropyl-substituted tetraethylene pentamine, propyl and
N-(3-hydroxybutyl)tetramethylene diamine.
[0085] Suitable arylpolyamines are analogous to the aromatic
monoamines mentioned above except for the presence within their
structure of another amino nitrogen. Some examples of
arylpolyamines include N,N'-di-n-butyl-para-phenylene diamine and
bis-(para-aminophenyl)methane.
[0086] Suitable heterocyclic mono- and polyamines will be known to
the person skilled in the art. Specific examples of such
heterocyclic amines include N-aminopropylmorpholine,
N-aminoethylpiperazine, and N,N'-diaminoethylpiperazine. Hydroxy
heterocyclic polyamines may also be used for example
N-(2-hydroxyethyl)cyclohexylamine, 3-hydroxycyclopentylamine,
parahydroxy-aniline and N-hydroxyethlpiperazine.
[0087] Examples of polyalkene-substituted amines can include:
poly(propylene)amine, poly(butene)amine,
N,N-dimethylpolyisobutyleneamine; N-polybutenemorpholine,
N-poly(butene)ethylenediamine,
N-poly(propylene)trimethylenediamine,
N-poly(butene)diethylenetriamine,
N',N'-poly(butene)tetraethylenepentamine, and
N,N-dimethyl-N'poly(propylene)-1,3 propylenediamine.
[0088] The number average molecular weight of the
polyalkene-substituted amines can range from 500 to 5000, or from
500 to 3000, for example from 1000 to 1500.
[0089] Any of the above polyalkene-substituted amines which are
secondary or primary amines, may be alkylated to tertiary amines
using alkylating agents. Suitable alkylating agents and method
using these will be known to the person skilled in the art.
[0090] To form the quaternary ammonium salt additives useful in the
present invention, the nitrogen containing species having a
tertiary amine group is reacted with a quaternizing agent.
[0091] The quaternizing agent is suitably selected from the group
consisting of dialkyl sulphates; an ester of a carboxylic acid;
alkyl halides; benzyl halides; hydrocarbyl substituted carbonates;
and hydrocarbyl epoxides in combination with an acid or mixtures
thereof.
[0092] In fuel applications it is often desirable to reduce the
levels of halogen-, sulfur-, and phosphorus-containing species.
Thus if a quaternizing agent containing such an element is used it
may be advantageous to carry out a subsequent reaction to exchange
the counterion. For example a quarternary ammonium salt formed by
reaction with an alkyl halide could be subsequently reacted with
sodium hydroxide and the sodium halide salt removed by
filtration.
[0093] The quaternizing agent can include halides, such as
chloride, iodide or bromide; hydroxides; sulphonates; bisulphites,
alkyl sulphates, such as dimethyl sulphate; sulphones; phosphates;
C1-12 alkylphosphates; di C1-12 alkylphosphates; borates; C1-12
alkylborates; nitrites; nitrates; carbonates; bicarbonates;
alkanoates; O,O-di C1-12 alkyldithiophosphates; or mixtures
thereof.
[0094] In one embodiment the quaternizing agent may be derived from
dialkyl sulphates such as dimethyl sulphate, N-oxides, sulphones
such as propane and butane sulphone; alkyl, acyl or aralkyl halides
such as methyl and ethyl chloride, bromide or iodide or benzyl
chloride, and a hydrocarbyl (or alkyl) substituted carbonates. If
the acyl halide is benzyl chloride, the aromatic ring is optionally
further substituted with alkyl or alkenyl groups. The hydrocarbyl
(or alkyl) groups of the hydrocarbyl substituted carbonates may
contain 1 to 50, 1 to 20, 1 to 10 or 1 to 5 carbon atoms per group.
In one embodiment the hydrocarbyl substituted carbonates contain
two hydrocarbyl groups that may be the same or different. Examples
of suitable hydrocarbyl substituted carbonates include dimethyl or
diethyl carbonate.
[0095] In another embodiment the quaternizing agent can be a
hydrocarbyl epoxide, as represented by the following formula:
##STR00002##
wherein R1, R2, R3 and R4 can be independently H or a C1-50
hydrocarbyl group.
[0096] Examples of hydrocarbyl epoxides can include styrene oxide,
ethylene oxide, propylene oxide, butylene oxide, stilbene oxide and
C2-50 epoxide. Styrene oxide is especially preferred.
[0097] Typically such hydrocarbyl epoxide quaternising agents are
used in combination with an acid, for example acetic acid. However
in embodiments in which component (i) includes the reaction product
of a substituted succinic acid which is an ester or an amide and
which also includes a further unreacted carboxylic acid group, an
additional acid may be omitted and the hydrocarybl epoxide may be
used alone as the quaternising agent. It is believed that formation
of the quaternary ammonium salt is promoted by protonation by the
carboxylic acid group also present in the molecule.
[0098] In such embodiments in which a further acid is not used, the
quaternary ammonium salt is suitably prepared in a protic solvent.
Suitable protic solvents include water, alcohols (including
polyhydric alcohols) and mixtures thereof. Preferred protic
solvents have a dielectric constant of greater than 9.
[0099] Suitable quaternary ammonium salts prepared from amides and
or esters of succinic acid derivatives are described in
WO2010/132259.
[0100] In some preferred embodiments the quaternizing agent
comprises a compound of formula (III):
##STR00003##
wherein R is an optionally substituted alkyl, alkenyl, aryl or
alkylaryl group; and R.sup.1 is a C.sub.1 to C.sub.22 alkyl, aryl
or alkylaryl group.
[0101] The compound of formula (III) is an ester of a carboxylic
acid capable of reacting with a tertiary amine to form a quaternary
ammonium salt.
[0102] Suitable compounds of formula (III) include esters of
carboxylic acids having a pK.sub.a of 3.5 or less.
[0103] The compound of formula (III) is preferably an ester of a
carboxylic acid selected from a substituted aromatic carboxylic
acid, an a-hydroxycarboxylic acid and a polycarboxylic acid.
[0104] In some preferred embodiments the compound of formula (III)
is an ester of a substituted aromatic carboxylic acid and thus R is
a subsituted aryl group.
[0105] Preferably R is a substituted aryl group having 6 to 10
carbon atoms, preferably a phenyl or naphthyl group, most
preferably a phenyl group. R is suitably substituted with one or
more groups selected from carboalkoxy, nitro, cyano, hydroxy,
SR.sup.5 or NR.sup.5R.sup.6. Each of R.sup.5 and R.sup.6 may be
hydrogen or optionally substituted alkyl, alkenyl, aryl or
carboalkoxy groups.
[0106] Preferably each of R.sup.5 and R.sup.6 is hydrogen or an
optionally substituted C.sub.1 to C.sub.22 alkyl group, preferably
hydrogen or a C.sub.1 to C.sub.16 alkyl group, preferably hydrogen
or a C.sub.1 to C.sub.10 alkyl group, more preferably hydrogen
C.sub.1 to C.sub.4 alkyl group. Preferably R.sup.5 is hydrogen and
R.sup.6 is hydrogen or a C.sub.1 to C.sub.4 alkyl group. Most
preferably R.sup.5 and R.sup.6 are both hydrogen. Preferably R is
an aryl group substituted with one or more groups selected from
hydroxyl, carboalkoxy, nitro, cyano and NH.sub.2. R may be a
poly-substituted aryl group, for example trihydroxyphenyl.
Preferably R is a mono-substituted aryl group. Preferably R is an
ortho substituted aryl group. Suitably R is substituted with a
group selected from OH, NH.sub.2, NO.sub.2 or COOMe. Preferably R
is substituted with an OH or NH.sub.2 group. Suitably R is a
hydroxy substituted aryl group. Most preferably R is a
2-hydroxyphenyl group.
[0107] Preferably R.sup.1 is an alkyl or alkylaryl group. R.sup.1
may be a C.sub.1 to C.sub.16 alkyl group, preferably a C.sub.1 to
C.sub.10 alkyl group, suitably a C.sub.1 to C.sub.8 alkyl group.
R.sup.1 may be C.sub.1 to C.sub.16 alkylaryl group, preferably a
C.sub.1 to C.sub.10 alkylgroup, suitably a C.sub.1 to C.sub.8
alkylaryl group. R.sup.1 may be methyl, ethyl, propyl, butyl,
pentyl, benzyl or an isomer thereor. Preferably R.sup.1 is benzyl
or methyl. Most preferably R.sup.1 is methyl.
[0108] An especially preferred compound of formula (III) is methyl
salicylate.
[0109] In some embodiments the compound of formula (III) is an
ester of an a-hydroxycarboxylic acid. In such embodiments the
compound of formula (III) has the structure:
##STR00004##
wherein R.sup.7 and R.sup.8 are the same or different and each is
selected from hydrogen, alkyl, alkenyl, aralkyl or aryl. Compounds
of this type suitable for use herein are described in EP
1254889.
[0110] Examples of compounds of formula (III) in which RCOO is the
residue of an .alpha.-hydroxycarboxylic acid include methyl-,
ethyl-, propyl-, butyl-, pentyl-, hexyl-, benzyl-, phenyl-, and
allyl esters of 2-hydroxyisobutyric acid; methyl-, ethyl-, propyl-,
butyl-, pentyl-, hexyl-, benzyl-, phenyl-, and allyl esters of
2-hydroxy-2-methylbutyric acid; methyl-, ethyl-, propyl-, butyl-,
pentyl-, hexyl-, benzyl-, phenyl-, and allyl esters of
2-hydroxy-2-ethylbutyric acid; methyl-, ethyl-, propyl-, butyl-,
pentyl-, hexyl-, benzyl-, phenyl-, and allyl esters of lactic acid;
and methyl-, ethyl-, propyl-, butyl-, pentyl-, hexyl-, allyl-,
benzyl-, and phenyl esters of glycolic acid. Of the above, a
preferred compound is methyl 2-hydroxyisobutyrate.
[0111] In some embodiments the compound of formula (III) is an
ester of a polycarboxylic acid. In this definition we mean to
include dicarboxylic acids and carboxylic acids having more than 2
acidic moieties. In such embodiments RCOO is preferably present in
the form of an ester, that is the one or more further acid groups
present in the group R are in esterified form. Preferred esters are
C.sub.1 to C.sub.4 alkyl esters.
[0112] Compound (III) may be selected from the diester of oxalic
acid, the diester of phthalic acid, the diester of maleic acid, the
diester of malonic acid or the diester of citric acid. One
especially preferred compound of formula (III) is dimethyl
oxalate.
[0113] In preferred embodiments the compound of formula (III) is an
ester of a carboxylic acid having a pK.sub.a of less than 3.5. In
such embodiments in which the compound includes more than one acid
group, we mean to refer to the first dissociation constant.
[0114] Compound (III) may be selected from an ester of a carboxylic
acid selected from one or more of oxalic acid, phthalic acid,
salicylic acid, maleic acid, malonic acid, citric acid,
nitrobenzoic acid, aminobenzoic acid and 2,4,6-trihydroxybenzoic
acid.
[0115] Preferred compounds of formula (III) include dimethyl
oxalate, methyl 2-nitrobenzoate and methyl salicylate.
[0116] An especially preferred quaternary ammonium salt for use
herein is formed by reacting methyl 2-hydroxybenzoate or styrene
oxide with the reaction product of a polyisobutylene-substituted
succinic anhydride having a PIB molecular weight of 700 to 1000 and
dimethylaminopropylamine.
[0117] The diesel fuel composition used in the method of the
present invention comprises a detergent additive which is not a
quaternary ammonium salt or a Mannich reaction product. The
detergent additive is not a quaternary ammonium salt as defined
herein. The detergent additive is not the product of a Mannich
reaction between an aldehyde, an amine and an optionally
substituted phenol.
[0118] Preferably the detergent additive is selected from one or
more of:
[0119] (a) the reaction product of a carboxylic acid-derived
acylating agent and an amine;
[0120] (b) the reaction product of a carboxylic acid-derived
acylating agent and hydrazine;
[0121] (c) a salt formed by the reaction of a carboxylic acid with
di-n-butylamine or tri-n-butylamine;
[0122] (d) the reaction product of a hydrocarbyl-substituted
dicarboxylic acid or anhydride and an amine compound or salt which
product comprises at least one amino triazole group; and
[0123] (e) a substituted polyaromatic detergent additive.
[0124] When the detergent additive comprises component (a) it is
preferably formed by the reaction of an acylating agent having a
hydrocarbyl substituent of at least 8 carbon atoms and a compound
comprising at least one primary or secondary amine group. The
acylating agent may be a mono- or polycarboxylic acid (or reactive
equivalent thereof) for example a substituted succinic, phthalic or
propionic acid and the amino compound may be a polyamine or a
mixture of polyamines, for example a mixture of ethylene
polyamines. Alternatively the amine may be a
hydroxyalkyl-substituted polyamine. The hydrocarbyl substituent in
such acylating agents is preferably as defined herein in relation
to the nitrogen containing species (i) of the quaternary salts.
[0125] Amino compounds useful for reaction with these acylating
agents include the following:
[0126] (1) polyalkylene polyamines of the general formula:
(R.sup.3).sub.2N[U--N(R.sup.3)].sub.nR.sup.3
wherein each R.sup.3 is independently selected from a hydrogen
atom, a hydrocarbyl group or a hydroxy-substituted hydrocarbyl
group containing up to about 30 carbon atoms, with proviso that at
least one R.sup.3 is a hydrogen atom, n is a whole number from 1 to
10 and U is a C1-18 alkylene group. Preferably each R.sup.3 is
independently selected from hydrogen, methyl, ethyl, propyl,
isopropyl, butyl and isomers thereof. Most preferably each R.sup.3
is ethyl or hydrogen. U is preferably a C1-4 alkylene group, most
preferably ethylene.
[0127] (2) heterocyclic-substituted polyamines including
hydroxyalkyl-substituted polyamines wherein the polyamines are as
described above and the heterocyclic substituent is selected from
nitrogen-containing aliphatic and aromatic heterocycles, for
example piperazines, imidazolines, pyrimidines, morpholines,
etc.
[0128] (3) aromatic polyamines of the general formula:
Ar(NR.sup.3.sub.2).sub.y
wherein Ar is an aromatic nucleus of 6 to 20 carbon atoms, each
R.sup.3 is as defined above and y is from 2 to 8.
[0129] Specific examples of polyalkylene polyamines (1) include
ethylenediamine, diethylenetriamine, triethylenetetramine,
tetraethylenepentamine, tri(tri-methylene)tetramine,
pentaethylenehexamine, hexaethylene-heptamine,
1,2-propylenediamine, and other commercially available materials
which comprise complex mixtures of polyamines. For example, higher
ethylene polyamines optionally containing all or some of the above
in addition to higher boiling fractions containing 8 or more
nitrogen atoms etc. Specific examples of hydroxyalkyl-substituted
polyamines include N-(2-hydroxyethyl)ethylene diamine,
N,N'-bis(2-hydroxyethyl)ethylene diamine,
N-(3-hydroxybutyl)tetramethylene diamine, etc. Specific examples of
the heterocyclic-substituted polyamines (2) are N-2-aminoethyl
piperazine, N-2 and N-3 amino propyl morpholine, N-3(dimethyl
amino)propyl piperazine, 2-heptyl-3-(2-aminopropyl)imidazoline,
1,4-bis(2-aminoethyl)piperazine, 1-(2-hydroxy ethyl)piperazine, and
2-heptadecyl-1-(2-hydroxyethyl)-imidazoline, etc. Specific examples
of the aromatic polyamines (3) are the various isomeric phenylene
diamines, the various isomeric naphthalene diamines, etc.
[0130] Many patents have described useful acylated nitrogen
compounds including U.S. Pat. Nos. 3,172,892; 3,219,666; 3,272,746;
3,310,492; 3,341,542; 3,444,170; 3,455,831; 3,455,832; 3,576,743;
3,630,904; 3,632,511; 3,804,763, 4,234,435 and U.S. Pat. No.
6,821,307.
[0131] One preferred detergent additive of this class is that made
by reacting a poly(isobutene)-substituted succinic acid-derived
acylating agent (e.g., anhydride, acid, ester, etc.) wherein the
poly(isobutene) substituent has between about 12 to about 200
carbon atoms with a mixture of ethylene polyamines having 3 to
about 9 amino nitrogen atoms per ethylene polyamine and about 1 to
about 8 ethylene groups. These acylated nitrogen compounds are
formed by the reaction of a molar ratio of acylating agent : amino
compound of from 10:1 to 1:10, preferably from 5:1 to 1:5, more
preferably from 2:1 to 1:2 and most preferably from 2:1 to 1:1. In
especially preferred embodiments, the acylated nitrogen compounds
are formed by the reaction of acylating agent to amino compound in
a molar ratio of from 1.8:1 to 1:1.2, preferably from 1.6:1 to
1:1.2, more preferably from 1.4:1 to 1:1.1 and most preferably from
1.2:1 to 1:1. This type of acylated amino compound and the
preparation thereof is well known to those skilled in the art and
are described in the above-referenced US patents.
[0132] A further preferred acylated nitrogen compound is one formed
by the reaction of a succinic acid-derived acylating agent having a
C1 to C20 alkyl substituent with an amine. In such embodiments, the
succinic acid acylating agent is preferably substituted with C8 to
C16 substituent, most preferably a C12 substituent. This is
preferably reacted with a polyalkylene polyamine as described above
or especially hydrazine. The ratio of acylating agent to the amine
is preferably from 2:1 to 1:1.
[0133] Another type of detergent additive belonging to this class
is that made by reacting the afore-described alkylene amines with
the afore-described substituted succinic acids or anhydrides and
aliphatic mono-carboxylic acids having from 2 to about 22 carbon
atoms. In these types of acylated nitrogen compounds, the mole
ratio of succinic acid to mono-carboxylic acid ranges from about
1:0.1 to about 1:1. Typical of the monocarboxlyic acid are formic
acid, acetic acid, dodecanoic acid, butanoic acid, oleic acid,
stearic acid, the commercial mixture of stearic acid isomers known
as isostearic acid, tolyl acid, etc. Such materials are more fully
described in U.S. Pat. Nos. 3,216,936 and 3,250,715.
[0134] A further type of detergent additive belonging to this class
suitable for use in the present invention is the product of the
reaction of a fatty monocarboxylic acid of about 12-30 carbon atoms
and the afore-described alkylene amines, typically, ethylene,
propylene or trimethylene polyamines containing 2 to 8 amino groups
and mixtures thereof. The fatty mono-carboxylic acids are generally
mixtures of straight and branched chain fatty carboxylic acids
containing 12-30 carbon atoms. Fatty dicarboxylic acids could also
be used. A widely used type of acylated nitrogen compound is made
by reacting the afore-described alkylene polyamines with a mixture
of fatty acids having from 5 to about 30 mole percent straight
chain acid and about 70 to about 95 percent mole branched chain
fatty acids. Among the commercially available mixtures are those
known widely in the trade as isostearic acid. These mixtures are
produced as a by-product from the dimerization of unsaturated fatty
acids as described in U.S. Pat. Nos. 2,812,342 and 3,260,671.
[0135] The branched chain fatty acids can also include those in
which the branch may not be alkyl in nature, for example phenyl and
cyclohexyl stearic acid and the chloro-stearic acids. Branched
chain fatty carboxylic acid/alkylene polyamine products have been
described extensively in the art. See for example, U.S. Pat. Nos.
3,110,673; 3,251,853; 3,326,801; 3,337,459; 3,405,064; 3,429,674;
3,468,639; 3,857,791. These patents are referenced for their
disclosure of fatty acid/polyamine condensates for their use in
lubricating oil formulations.
[0136] In some preferred embodiments the compositon comprises a
detergent of the type formed by the reaction of a
polyisobutene-substituted succinic acid-derived acylating agent and
a polyethylene polyamine. Suitable compounds are, for example,
described in WO2009/040583.
[0137] Preferred nitrogen-containing detergents comprising
component (a) for use herein include: the compound formed by
reacting a polyisobutylene succinic anhydride (PIBSA) having a PIB
molecular weight of 900 to 1100, for example approximately 1000,
with aminoethyl ethanolamine or triethylene tetramine; and the
compound formed by reacting a PIBSA having a PIB molecular weight
of 650 to 850, for example about 750 with tetraethylene pentamine.
In each case the ratio of PIBSA to amine is from 1.5:1 to 0.9:1,
preferably from 1.2:1 to 1:1.
[0138] When the detergent additive comprises component (b) it may
suitably comprise an additive comprising the reaction product
between a hydrocarbyl-substituted succinic acid or anhydride and
hydrazine.
[0139] Preferably, the hydrocarbyl group of the
hydrocarbyl-substituted succinic acid or anhydride comprises a
C.sub.8-C.sub.36 group, preferably a C.sub.8-C.sub.18 group.
Non-limiting examples include dodecyl, hexadecyl and octadecyl.
Alternatively, the hydrocarbyl group may be a polyisobutylene group
with a number average molecular weight of between 200 and 2500,
preferably between 800 and 1200. Mixtures of species with different
length hydrocarbyl groups are also suitable, e.g. a mixture of
C.sub.16-C.sub.18 groups.
[0140] The hydrocarbyl group is attached to a succinic acid or
anhydride moiety using methods known in the art. Additionally, or
alternatively, suitable hydrocarbyl-substituted succinic acids or
anhydrides are commercially available e.g. dodecylsuccinic
anhydride (DDSA), hexadecylsuccinic anhydride (HDSA),
octadecylsuccinic anhydride (ODSA) and polyisobutylsuccinic
anhydride (PIBSA).
[0141] Hydrazine has the formula NH.sub.2-NH.sub.2. Hydrazine may
be hydrated or non-hydrated. Hydrazine monohydrate is
preferred.
[0142] The reaction between the hydrocarbyl-substituted succinic
acid or anhydride and hydrazine produces a variety of products,
such as is disclosed in EP 1887074. It is believed to be preferable
for good detergency that the reaction product contains a
significant proportion of species with relatively high molecular
weight. It is believed--without the matter having been definitively
determined yet, to the best of our knowledge--that a major high
molecular weight product of the reaction is an oligomeric species
predominantly of the structure:
##STR00005##
where n is an integer and greater than 1, preferably between 2 and
10, more preferably between 2 and 7, for example 3, 4 or 5. Each
end of the oligomer may be capped by one or more of a variety of
groups. Some possible examples of these terminal groups
include:
##STR00006##
[0143] Alternatively, the oligomeric species may form a ring having
no terminal groups:
##STR00007##
[0144] Further preferred features of embodiments in which the
detergent additive comprises component (b) are as defined in EP
1887074.
[0145] When the detergent additive comprises component (c) this is
suitably the di-n-butylamine or tri-n-butylamine salt of a fatty
acid of the formula [R'(COOH).sub.x].sub.y', where each R' is a
independently a hydrocarbon group of between 2 and 45 carbon atoms,
and x is an integer between 1 and 4.
[0146] Preferably R' is a hydrocarbon group of 8 to 24 carbon
atoms, more preferably 12 to 20 carbon atoms. Preferably, x is 1 or
2, more preferably x is 1. Preferably, y is 1, in which case the
acid has a single R' group. Alternatively, the acid may be a dimer,
trimer or higher oligomer acid, in which case y will be greater
than 1 for example 2, 3 or 4 or more. R' is suitably an alkyl or
alkenyl group which may be linear or branched. Examples of
carboxylic acids which may be used in the present invention include
lauric acid, myristic acid, palmitic acid, stearic acid, isostearic
acid, neodecanoic acid, arachic acid, behanic acid, lignoceric
acid, cerotic acid, montanic acid, melissic acid, caproleic acid,
oleic acid, elaidic acid, linoleic acid, linolenic acid, coconut
oil fatty acid, soy bean fatty acid, tall oil fatty acid, sunflower
oil fatty acid, fish oil fatty acid, rapeseed oil fatty acid,
tallow oil fatty acid and palm oil fatty acid. Mixtures of two or
more acids in any proportion are also suitable. Also suitable are
the anhydrides of carboxylic acids, their derivatives and mixtures
thereof. In a preferred embodiment, the carboxylic acid comprises
tall oil fatty acid (TOFA). It has been found that TOFA with a
saturate content of less than 5% by weight is especially
suitable.
[0147] Further preferred features of embodiments in which the
detergent additive comprises component (c) are as defined in EP
1900795.
[0148] When the detergent additive comprises component (d) this is
suitably reaction product of a hydrocarbyl substituted dicarboxylic
acid or anhydride and an amine compound having the formula:
##STR00008##
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.
[0149] Component (d) suitably comprises the reaction product of an
amine compound having the formula:
##STR00009##
and a hydrocarbyl carbonyl compound of the formula:
##STR00010##
wherein R.sup.2 is a hydrocarbyl group having a number average
molecular weight ranging from about 100 to about 5000, preferably
from 200 to 3000.
[0150] Without being bound by theory, it is believed that the
reaction product of the amine and hydrocarbyl carbonyl compound is
an aminotriazole, such as a bis-aminotriazole compound of the
formula:
##STR00011##
including tautomers having a number average molecular weight
ranging from about 200 to about 3000 containing from about 40 to
about 80 carbon atoms. The five-membered ring of the triazole is
considered to be aromatic.
[0151] Examples of suitable hydrocarbyl groups include:
[0152] (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);
[0153] (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);
[0154] (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.
[0155] Non-limiting examples of suitable hydrocarbyl carbonyl
compounds include, but are not limited to, hydrocarbyl substituted
succinic anhydrides, hydrocarbyl substituted succinic acids, and
esters of hydrocarbyl substituted succinic acids. In some preferred
embodiments the hydrocarbyl carbonyl compounds may comprise a
polyisobutenyl-substitued succinic acid or succinic anhydride. Such
compounds are suitably as described in relation to the
hydrocarbyl-substituted acylating agent of the nitrogen-containing
species (i) above.
[0156] Suitable amine compounds of the formula:
##STR00012##
may be chosen from guanidines and aminoguanidines or salts thereof
wherein R and R.sup.1 are as defined above. Accordingly, the amine
compound may be chosen from the inorganic salts of guanidines, such
as the halide, carbonate, nitrate, phosphate, and orthophosphate
salts of guanidines. The term "guanidines" refers to guanidine and
guanidine derivatives, such as aminoguanidine. In one embodiment,
the guanidine compound for the preparation of the additive is
aminoguanidine bicarbonate. Aminoguanidine bicarbonates are readily
obtainable from commercial sources, or can be prepared in a
well-known manner.
[0157] Further preferred features of embodiments in which the
detergent additive comprises component (d) are as defined in
US2009/0282731.
[0158] When the detergent additive comprises component (e) this
preferably comprises at least one compound of formula (IV) and/or
formula (V):
##STR00013##
wherein each Ar independently represents an aromatic moiety having
0 to 3 substituents selected from the group consisting of alkyl,
alkoxy, alkoxyalkyl, aryloxy, aryloxyalkyl, hydroxy, hydroxyalkyl,
halo and combinations thereof;
[0159] each L is independently a linking moiety comprising a
carbon-carbon single bond or a linking group;
[0160] each Y is independently --OR.sup.1'' or a moiety of the
formula H(O(CR.sup.1.sub.2).sub.n).sub.yX--, wherein X is selected
from the group consisting of (CR.sup.1.sub.2).sub.2, O and S:
R.sup.1 and R.sup.1' are each independently selected from H,
C.sub.1 to C.sub.6 alkyl and aryl; R.sup.1'' is selected from
C.sub.1 to C.sub.100 alkyl and aryl; z is 1 to 10; n is 0 to 10
when X is (CR.sup.1.sub.2).sub.2, and 2 to 10 when X is O or S; and
y is 1 to 30;
[0161] each a is independently 0 to 3, with the proviso that at
least one Ar moiety bears at least one group Y; and m is 1 to 100;
preferably Ar is naphthalene, y is HOCH.sub.2CH.sub.2O-- and L is
--CH.sub.2--;
##STR00014##
wherein each Ar' independently represents an aromatic moiety having
0 to 3 substituents selected from the group consisting of alkyl,
alkoxy, alkoxyalkyl, hydroxy, hydroxyalkyl, acyloxy, acyloxyalkyl,
acyloxyalkoxy, aryloxy, aryloxyalkyl, aryloxyalkoxy, halo and
combinations thereof;
[0162] each L' is independently a linking moiety comprising a
carbon-carbon single bond or linking group;
[0163] each Y' is independently a moiety of the formula ZO-- or
Z(O(CR.sup.2.sub.2).sub.n').sub.y'X'--, wherein X' is selected from
the group consisting of (CR.sup.2'.sub.2).sub.z', O and S; R.sup.2
and R.sup.2' are each independently selected from H, C.sub.1 to
C.sub.6 alkyl and aryl z' is 1 to 10; n' is 0 to 10 when X' is
(CR.sup.2'.sub.2).sub.z, and 2 to 10 when X' is O or S; y is 1 to
30; Z is H, an acyl group, a polyacyl group, a lactone ester group,
an acid ester group, an alkyl group or an aryl group;
[0164] each a' is independently 0 to 3, with the proviso that at
least one Ar' moiety bears at least one group Y' in which Z is not
H; and m' is 1 to 100.
[0165] In a preferred embodiment compound of formula (V) is the
reaction product of an ethoxylated naphthol and paraformaldehyde
which is then reacted with a hydrocarbyl substituted acylating
agent.
[0166] Further preferred features of embodiments in which the
detergent additive comprises component (e) are as defined in EP
1884556.
[0167] According to a second aspect of the present invention there
is provided a diesel fuel composition for use in the method of the
first aspect. Preferred features of the second aspect are as
defined in relation to the first aspect.
[0168] Suitable treat rates of the quaternary ammonium salt
additive and the detergent additive will depend on the desired
performance and on the type of engine in which they are used. For
example different levels of additive may be needed to achieve
different levels of performance.
[0169] Suitably the quaternary ammonium salt additive is present in
the diesel fuel composition used in the method of the present
invention in an amount of less than 10000 ppm, preferably less than
1000 ppm, preferably less than 500 ppm, preferably less than 250
ppm.
[0170] Suitably the detergent additive when used is present in the
diesel fuel composition used in the method of the present invention
in an amount of less than 10000 ppm, 1000 ppm preferably less than
500 ppm, preferably less than 250 ppm.
[0171] The weight ratio of the quaternary ammonium salt additive to
the detergent additive is preferably from 1:10 to 10:1, preferably
from 1:4 to 4:1.
[0172] The diesel fuel composition may comprises a mixture of one
or more detergent additives and/or one or more quaternary ammonium
salt additives. In embodiments in which more than one detergent
additive and/or more than one quaternary ammonium salt additive is
present, the above amounts and ratios refer to all additives of
that particular type present in the composition.
[0173] As stated previously, fuels containing biodiesel or metals
are known to cause fouling. Severe fuels, for example those
containing high levels of metals and/or high levels of biodiesel
may require higher treat rates of the quaternary ammonium salt
additive and/or detergent additive than fuels which are less
severe.
[0174] In some preferred embodiments the diesel fuel composition
comprises detergent additive (a) and a quaternary ammonium salt
formed from component (i).
[0175] In some preferred embodiments the diesel fuel composition
comprises detergent additive (b) and a quaternary ammonium salt
formed from component (i).
[0176] In some preferred embodiments the diesel fuel composition
comprises detergent additive (c) and a quaternary ammonium salt
formed from component (i).
[0177] In some preferred embodiments the diesel fuel composition
comprises detergent additive (d) and a quaternary ammonium salt
formed from component (i).
[0178] In some preferred embodiments the diesel fuel composition
comprises detergent additive (e) and a quaternary ammonium salt
formed from component (i).
[0179] In some preferred embodiments the diesel fuel composition
comprises detergent additive (a) and a quaternary ammonium salt
formed from component (ii).
[0180] In some preferred embodiments the diesel fuel composition
comprises detergent additive (b) and a quaternary ammonium salt
formed from component (ii).
[0181] In some preferred embodiments the diesel fuel composition
comprises detergent additive (c) and a quaternary ammonium salt
formed from component (ii).
[0182] In some preferred embodiments the diesel fuel composition
comprises detergent additive (d) and a quaternary ammonium salt
formed from component (ii).
[0183] In some preferred embodiments the diesel fuel composition
comprises detergent additive (e) and a quaternary ammonium salt
formed from component (ii).
[0184] In some preferred embodiments the diesel fuel composition
comprises detergent additive (a) and a quaternary ammonium salt
formed from component (iii).
[0185] In some preferred embodiments the diesel fuel composition
comprises detergent additive (b) and a quaternary ammonium salt
formed from component (iii).
[0186] In some preferred embodiments the diesel fuel composition
comprises detergent additive (c) and a quaternary ammonium salt
formed from component (iii).
[0187] In some preferred embodiments the diesel fuel composition
comprises detergent additive (d) and a quaternary ammonium salt
formed from component (iii).
[0188] In some preferred embodiments the diesel fuel composition
comprises detergent additive (e) and a quaternary ammonium salt
formed from component (iii).
[0189] The diesel fuel composition of the present invention may
include one or more further additives such as those which are
commonly found in diesel fuels. These include, for example,
antioxidants, dispersants, detergents, metal deactivating
compounds, wax anti-settling agents, cold flow improvers, cetane
improvers, dehazers, stabilisers, demulsifiers, antifoams,
corrosion inhibitors, lubricity improvers, dyes, markers,
combustion improvers, metal deactivators, odour masks, drag
reducers and conductivity improvers. Examples of suitable amounts
of each of these types of additives will be known to the person
skilled in the art.
[0190] By diesel fuel we include any fuel suitable for use in a
diesel engine either for road use or non-road use. This includes
but is not limited to fuels described as diesel, marine diesel,
heavy fuel oil, industrial fuel oil, etc.
[0191] The diesel fuel composition of the present invention may
comprise a petroleum-based fuel oil, especially a middle distillate
fuel oil. Such distillate fuel oils generally boil within the range
of from 110.degree. C. to 500.degree. C., e.g. 150.degree. C. to
400.degree. C. The diesel fuel may comprise atmospheric distillate
or vacuum distillate, cracked gas oil, or a blend in any proportion
of straight run and refinery streams such as thermally and/or
catalytically cracked and hydro-cracked distillates.
[0192] The diesel fuel composition of the present invention may
comprise non-renewable Fischer-Tropsch fuels such as those
described as GTL (gas-to-liquid) fuels, CTL (coal-to-liquid) fuels
and OTL (oil sands-to-liquid).
[0193] The diesel fuel composition of the present invention may
comprise a renewable fuel such as a biofuel composition or
biodiesel composition.
[0194] The diesel fuel composition may comprise 1st generation
biodiesel. First generation biodiesel contains esters of, for
example, vegetable oils, animal fats and used cooking fats. This
form of biodiesel may be obtained by transesterification of oils,
for example rapeseed oil, soybean oil, safflower oil, palm 25 oil,
corn oil, peanut oil, cotton seed oil, tallow, coconut oil, physic
nut oil (Jatropha), sunflower seed oil, used cooking oils,
hydrogenated vegetable oils or any mixture thereof, with an
alcohol, usually a monoalcohol, in the presence of a catalyst.
[0195] The diesel fuel composition may comprise second generation
biodiesel. Second generation biodiesel is derived from renewable
resources such as vegetable oils and animal fats and processed,
often in the refinery, often using hydroprocessing such as the
H-Bio process developed by Petrobras. Second generation biodiesel
may be similar in properties and quality to petroleum based fuel
oil streams, for example renewable diesel produced from vegetable
oils, animal fats etc. and marketed by ConocoPhillips as Renewable
Diesel and by Neste as NExBTL.
[0196] The diesel fuel composition of the present invention may
comprise third generation biodiesel. Third generation biodiesel
utilises gasification and Fischer-Tropsch technology including
those described as BTL (biomass-to-liquid) fuels. Third generation
biodiesel does not differ widely from some second generation
biodiesel, but aims to exploit the whole plant (biomass) and
thereby widens the feedstock base.
[0197] The diesel fuel composition may contain blends of any or all
of the above diesel fuel compositions.
[0198] In some embodiments the diesel fuel composition of the
present invention may be a blended diesel fuel comprising
bio-diesel. In such blends the bio-diesel may be present in an
amount of, for example up to 0.5%, up to 1%, up to 2%, up to 3%, up
to 4%, up to 5%, up to 10%, up to 20%, up to 30%, up to 40%, up to
50%, up to 60%, up to 70%, up to 80%, up to 90%, up to 95% or up to
99%.
[0199] In some embodiments the diesel fuel composition may comprise
a secondary fuel, for example ethanol. Preferably however the
diesel fuel composition does not contain ethanol.
[0200] The diesel fuel composition of the present invention may
contain a relatively high sulphur content, for example greater than
0.05% by weight, such as 0.1% or 0.2%.
[0201] However in preferred embodiments the diesel fuel has a
sulphur content of at most 0.05% by weight, more preferably of at
most 0.035% by weight, especially of at most 0.015%. Fuels with
even lower levels of sulphur are also suitable such as, fuels with
less than 50 ppm sulphur by weight, preferably less than 20 ppm,
for example 10 ppm or less.
[0202] Commonly when present, metal-containing species will be
present as a contaminant, for example through the corrosion of
metal and metal oxide surfaces by acidic species present in the
fuel or from lubricating oil. In use, fuels such as diesel fuels
routinely come into contact with metal surfaces for example, in
vehicle fuelling systems, fuel tanks, fuel transportation means
etc. Typically, metal-containing contamination may comprise
transition metals such as zinc, iron and copper; group I or group
II metals such as sodium; and other metals such as lead.
[0203] In addition to metal-containing contamination which may be
present in diesel fuels there are circumstances where
metal-containing species may deliberately be added to the fuel. For
example, as is known in the art, metal-containing fuel-borne
catalyst species may be added to aid with the regeneration of
particulate traps. Such catalysts are often based on metals such as
iron, cerium, Group I and Group II metals e.g., calcium and
strontium, either as mixtures or alone. Also used are platinum and
manganese. The presence of such catalysts may also give rise to
injector deposits when the fuels are used in diesel engines having
high pressure fuel systems.
[0204] Metal-containing contamination, depending on its source, may
be in the form of insoluble particulates or soluble compounds or
complexes. Metal-containing fuel-borne catalysts are often soluble
compounds or complexes or colloidal species.
[0205] In some embodiments, the metal-containing species comprises
a fuel-borne catalyst.
[0206] In some embodiments, the metal-containing species comprises
zinc.
[0207] Typically, the amount of metal-containing species in the
diesel fuel, expressed in terms of the total weight of metal in the
species, is between 0.1 and 50 ppm by weight, for example between
0.1 and 10 ppm by weight, based on the weight of the diesel
fuel.
[0208] According to a third aspect the present invention may also
provide an additive composition which upon addition to a diesel
fuel provides a composition of the second aspect. Preferred
features of the third aspect are as defined in relation to the
first and second aspects.
[0209] The first aspect of the present invention relates to a
method of reducing deposits in a diesel engine. Reducing deposits
may involve reducing or the preventing of the formation of deposits
in a diesel engine compared to when running the engine using
unadditised fuel. Such a method may be regarded as achieving "keep
clean" performance.
[0210] Reducing deposits may involve the removal of existing
deposits in a diesel engine. This may be regarded as achieving
"clean up" performance.
[0211] In especially preferred embodiments the method of the first
aspect of the present invention and the diesel fuel composition of
the second aspeect may be used to provide "keep clean" and "clean
up" performance.
[0212] In some preferred embodiments the method of the present
invention involves reducing deposits in a diesel engine having a
high pressure fuel system.
[0213] Modern diesel engines having a high pressure fuel system may
be characterised in a number of ways. Such engines are typically
equipped with fuel injectors having a plurality of apertures, each
aperture having an inlet and an outlet.
[0214] Such modern diesel engines may be characterised by apertures
which are tapered such that the inlet diameter of the spray-holes
is greater than the outlet diameter.
[0215] Such modern engines may be characterised by apertures having
an outlet diameter of less than 500 .mu.m, preferably less than 200
.mu.m, more preferably less than 150 .mu.m, preferably less than
100 .mu.m, most preferably less than 80 .mu.m or less.
[0216] Such modern diesel engines may be characterised by apertures
where an inner edge of the inlet is rounded.
[0217] Such modern diesel engines may be characterised by the
injector having more than one aperture, suitably more than 2
apertures, preferably more than 4 apertures, for example 6 or more
apertures.
[0218] Such modern diesel engines may be characterised by an
operating tip temperature in excess of 250.degree. C.
[0219] Such modern diesel engines may be characterised by a fuel
pressure of more than 1350 bar, preferably more than 1500 bar, more
preferably more than 2000 bar.
[0220] The method of the present invention is preferably carried
out in an engine having one or more of the above-described
characteristics.
[0221] The present invention is particularly useful in reducing
(deposits on injectors of engines operating at high pressures and
temperatures in which fuel may be recirculated and which comprise a
plurality of fine apertures through which the fuel is delivered to
the engine. The present invention finds utility in engines for
heavy duty vehicles and passenger vehicles. Passenger vehicles
incorporating a high speed direct injection (or HSDI) engine may
for example benefit from the present invention.
[0222] Within the injector body of modern diesel engines having a
high pressure fuel system, clearances of only 1-2 .mu.m may exist
between moving parts and there have been reports of engine problems
in the field caused by injectors sticking and particularly
injectors sticking open. Control of deposits in this area can be
very important.
[0223] According to a fourth aspect of the present invention there
is provided the use in a diesel fuel composition of the combination
of a detergent additive which is not a quaternary ammonium salt or
a Mannich reaction product and a quaternary ammonium salt additive
comprising the reaction product of nitrogen containing species
having at least one tertiary amine group and a quaternizing agent
to improve the performance of a diesel engine when using said
diesel fuel composition; wherein the nitrogen containing species is
selected from: [0224] (i) the reaction product of a
hydrocarbyl-substituted acylating agent and a compound comprising
at least one tertiary amine group and a primary amine, secondary
amine or alcohol group; [0225] (ii) a Mannich reaction product
comprising a tertiary amine group; and [0226] (iii) a polyalkylene
substituted amine having at least one tertiary amine group.
[0227] Preferred features of the fourth aspect are as defined in
relation to the first, second and third aspects.
[0228] Thus as described above the diesel fuel compositions of the
present invention may be used to improve the performance of modern
diesel engines having high pressure fuel systems. The diesel fuel
compositions of the present invention may also provide improved
performance when used with traditional diesel engines. Preferably
the improved performance is achieved when using the diesel fuel
compositions in modern diesel engines having high pressure fuel
systems and when using the compositions in traditional diesel
engines. This is important because it allows a single fuel to be
provided that can be used in new engines and older vehicles.
[0229] The improvement in performance of the diesel engine system
may be measured by a number of ways. Suitable methods will depend
on the type of engine and whether "keep clean" and/or "clean up"
performance is measured.
[0230] One of the ways in which the improvement in performance can
be measured is by measuring the power loss in a controlled engine
test. An improvement in "keep clean" performance may be measured by
observing a reduction in power loss compared to that seen in a base
fuel. "Clean up" performance can be observed by an increase in
power when diesel fuel compositions of the invention are used in an
already fouled engine.
[0231] The improvement in performance of the diesel engine having a
high pressure fuel system may be measured by an improvement in fuel
economy.
[0232] The use of the fourth aspect may also improve the
performance of the engine by reducing deposits in the vehicle fuel
filter. This may be a reduction or prevention of the formation of
deposits or the removal of existing deposits.
[0233] The level of deposits in a vehicle fuel filter may be
measured quantitatively or qualitatively. In some cases this may
only be determined by inspection of the filter once the filter has
been removed. In other cases, the level of deposits may be
estimated during use.
[0234] Many vehicles are fitted with a fuel filter which may be
visually inspected during use to determine the level of solids
build up and the need for filter replacement. For example, one such
system uses a filter canister within a transparent housing allowing
the filter, the fuel level within the filter and the degree of
filter blocking to be observed.
[0235] Using the fuel compositions of the present invention may
result in levels of deposits in the fuel filter which are
considerably reduced compared with fuel compositions not of the
present invention. This allows the filter to be changed much less
frequently and can ensure that fuel filters do not fail between
service intervals. Thus the use of the compositions of the present
invention may lead to reduced maintenance costs.
[0236] In some embodiments the occurrence of deposits in a fuel
filter may be inhibited or reduced. Thus a "keep clean" performance
may be observed. In some embodiments existing deposits may be
removed from a fuel filter. Thus a "clean up" performance may be
observed.
[0237] Improvement in performance may also be assessed by
considering the extent to which the use of the fuel compositions of
the invention reduce the amount of deposit on the injector of an
engine. For "keep clean" performance a reduction in occurrence of
deposits would be observed. For "clean up" performance removal of
existing deposits would be observed.
[0238] Direct measurement of deposit build up is not usually
undertaken, but is usually inferred from the power loss or fuel
flow rates through the injector.
[0239] The use of the fourth aspect may improve the performance of
the engine by reducing, preventing or removing deposits including
gums and lacquers within the injector body.
[0240] In Europe the Co-ordinating European Council for the
development of performance tests for transportation fuels,
lubricants and other fluids (the industry body known as CEC), has
developed a new test, named CEC F-98-08, to assess whether diesel
fuel is suitable for use in engines meeting new European Union
emissions regulations known as the "Euro 5" regulations. The test
is based on a Peugeot DW10 engine using Euro 5 injectors, and will
hereinafter be referred to as the DW10 test. This test is described
in example 1.
[0241] Preferably the use of the fuel composition of the present
invention leads to reduced deposits in the DW10 test. For "keep
clean" performance a reduction in the occurrence of deposits is
preferably observed. For "clean up" performance removal of deposits
is preferably observed. The DW10 test is used to measure the power
loss in modern diesel engines having a high pressure fuel
system.
[0242] For older engines an improvement in performance may be
measured using the XUD9 test. This test is described in example
2.
[0243] Suitably the method of the present invention may provide a
"keep clean" performance in modern diesel engines, that is the
formation of deposits on the injectors of these engines may be
inhibited or prevented. Preferably this performance is such that a
power loss of less than 5%, preferably less than 2% is observed
after 32 hours as measured by the DW10 test.
[0244] Suitably the method of the present invention may provide a
"clean up" performance in modern diesel engines, that is deposits
on the injectors of an already fouled engine may be removed.
Preferably this performance is such that the power of a fouled
engine may be returned to within 1% of the level achieved when
using clean injectors within 8 hours as measured in the DW10
test.
[0245] Preferably rapid "clean-up" may be achieved in which the
power is returned to within 1% of the level observed using clean
injectors within 4 hours, preferably within 2 hours.
[0246] Clean injectors can include new injectors or injectors which
have been removed and physically cleaned, for example in an
ultrasound bath.
[0247] Suitably the method the present invention may provide a
"keep clean" performance in traditional diesel engines, that is the
formation of deposits on the injectors of these engines may be
inhibited or prevented. Preferably this performance is such that a
flow loss of less than 50%, preferably less than 30% is observed
after 10 hours as measured by the XUD-9 test.
[0248] Suitably the method of the present invention may provide a
"clean up" performance in traditional diesel engines, that is
deposits on the injectors of an already fouled engine may be
removed. Preferably this performance is such that the flow loss of
a fouled engine may be increased by 10% or more within 10 hours as
measured in the XUD-9 test.
[0249] Any feature of any aspect of the invention may be combined
with any other feature, where appropriate.
EXAMPLE 1
[0250] The performance of fuel compositions of the present
invention in modern engines may be tested according to the
CECF-98-08 DW 10 method.
[0251] The engine of the injector fouling test is the PSA
DW10BTED4. In summary, the engine characteristics are:
[0252] Design: Four cylinders in line, overhead camshaft,
turbocharged with EGR
[0253] Capacity: 1998 cm.sup.3
[0254] Combustion chamber: Four valves, bowl in piston, wall guided
direct injection
[0255] Power: 100 kW at 4000 rpm
[0256] Torque: 320 Nm at 2000 rpm
[0257] Injection system: Common rail with piezo electronically
controlled 6-hole injectors.
[0258] Max. pressure: 1600 bar (1.6.times.10.sup.8 Pa). Proprietary
design by SIEMENS VDO
[0259] Emissions control: Conforms with Euro IV limit values when
combined with exhaust gas post-treatment system (DPF)
[0260] This engine was chosen as a design representative of the
modern European high-speed direct injection diesel engine capable
of conforming to present and future European emissions
requirements. The common rail injection system uses a highly
efficient nozzle design with rounded inlet edges and conical spray
holes for optimal hydraulic flow. This type of nozzle, when
combined with high fuel pressure has allowed advances to be
achieved in combustion efficiency, reduced noise and reduced fuel
consumption, but are sensitive to influences that can disturb the
fuel flow, such as deposit formation in the spray holes. The
presence of these deposits causes a significant loss of engine
power and increased raw emissions.
[0261] The test is run with a future injector design representative
of anticipated Euro V injector technology.
[0262] It is considered necessary to establish a reliable baseline
of injector condition before beginning fouling tests, so a sixteen
hour running-in schedule for the test injectors is specified, using
non-fouling reference fuel.
[0263] Full details of the CEC F-98-08 test method can be obtained
from the CEC. The coking cycle is summarised below.
[0264] 1. A warm up cycle (12 minutes) according to the following
regime:
TABLE-US-00001 Duration Engine Torque Step (minutes) Speed (rpm)
(Nm) 1 2 idle <5 2 3 2000 50 3 4 3500 75 4 3 4000 100
[0265] 2. 8 hrs of engine operation consisting of 8 repeats of the
following cycle
TABLE-US-00002 Duration Engine Load Torque Boost Air After Step
(minutes) Speed (rpm) (%) (Nm) IC (.degree. C.) 1 2 1750 (20) 62 45
2 7 3000 (60) 173 50 3 2 1750 (20) 62 45 4 7 3500 (80) 212 50 5 2
1750 (20) 62 45 6 10 4000 100 * 50 7 2 1250 (10) 20 43 8 7 3000 100
* 50 9 2 1250 (10) 20 43 10 10 2000 100 * 50 11 2 1250 (10) 20 43
12 7 4000 100 * 50 * for expected range see CEC method
CEC-F-98-08
[0266] 3. Cool down to idle in 60 seconds and idle for 10 seconds
4. 4 hrs soak period
[0267] The standard CEC F-98-08 test method consists of 32 hours
engine operation corresponding to 4 repeats of steps 1-3 above, and
3 repeats of step 4. ie 56 hours total test time excluding warm ups
and cool downs.
EXAMPLE 2
[0268] The performance of fuel compositions of the present
invention in older engine types may be assessed using a standard
industry test--CEC test method No. CEC F-23-A-01.
[0269] This test measures injector nozzle coking using a Peugeot
XUD9 NL Engine and provides a means of discriminating between fuels
of different injector nozzle coking propensity. Nozzle coking is
the result of carbon deposits forming between the injector needle
and the needle seat. Deposition of the carbon deposit is due to
exposure of the injector needle and seat to combustion gases,
potentially causing undesirable variations in engine
performance.
[0270] The Peugeot XUD9 NL engine is a 4 cylinder indirect
injection Diesel engine of 1.9 litre swept volume, obtained from
Peugeot Citroen Motors specifically for the CEC PF023 method.
[0271] The test engine is fitted with cleaned injectors utilising
unflatted injector needles. The airflow at various needle lift
positions have been measured on a flow rig prior to test. The
engine is operated for a period of 10 hours under cyclic
conditions.
TABLE-US-00003 Stage Time (secs) Speed (rpm) Torque (Nm) 1 30 1200
.+-. 30 10 .+-. 2 2 60 3000 .+-. 30 50 .+-. 2 3 60 1300 .+-. 30 35
.+-. 2 4 120 1850 .+-. 30 50 .+-. 2
[0272] The propensity of the fuel to promote deposit formation on
the fuel injectors is determined by measuring the injector nozzle
airflow again at the end of test, and comparing these values to
those before test. The results are expressed in terms of percentage
airflow reduction at various needle lift positions for all nozzles.
The average value of the airflow reduction at 0.1 mm needle lift of
all four nozzles is deemed the level of injector coking for a given
fuel.
EXAMPLE 3
[0273] Additive A1 is a 60% active ingredient solution (in aromatic
solvent) of a polyisobutenyl succinimide obtained from the
condensation reaction of a polyisobutenyl succinic anhydride
(PIBSA) derived from polyisobutene of Mn approximately 1000 with a
polyethylene polyamine mixture of average composition approximating
to triethylene tetramine. The product was obtained by mixing the
PIBSA and polyethylene polyamine at 50.degree. C. under nitrogen
and heating at 160.degree. C. for 5 hours with removal of
water.
EXAMPLE 4
[0274] Additive A2 is a 60% active ingredient solution (in aromatic
solvent) of a polyisobutenyl succinimide obtained from the
condensation reaction of a polyisobutenyl succinic anhydride
derived from polyisobutene of Mn approximately 750 with a
polyethylene polyamine mixture of average composition approximating
to tetraethylene pentamine. The product was obtained by mixing the
PIBSA and polyethylene polyamine at 50.degree. C. under nitrogen
and heating at 160.degree. C. for 5 hours with removal of
water.
EXAMPLE 5
[0275] Additive B1 was prepared as follows:
[0276] 200 g of Dodecylsuccinic anhydride (0.75 mol) and 200 g
toluene were added to a vessel and stirred under nitrogen. The
temperature was raised to 50.degree. C. and hydrazine monohydrate
(112.8 g, 2.25 mol) added dropwise. Once addition was complete, the
mixture was heated to reflux for 5 hours. Toluene was removed at
40.degree. C. until no more bubbling was observed and then the
product was held for 4 hours under vacuum at 180.degree. C.
EXAMPLE 6
[0277] Additive C1 was prepared as follows:
[0278] 50 g of rape seed oil fatty acid (ROFA) (173 mmoles) and
22.4 g Di-n-butylamine (173 mmoles) were mixed with stirring. An
exotherm was observed. FTIR analysis of the reaction product
indicated that a salt had formed: there was a reduction in the
strong carboxylic acid peak at 1710 cm.sup.-1 compared to the
starting acid, and carboxylate antisymmetric and symmetric
stretches at 1553 and 1399 cm.sup.-1 appeared as well a broad range
of peaks 2300-2600 cm.sup.-1 assignable to ammonium species.
EXAMPLE 7
[0279] Additive D1 was prepared as follows:
[0280] A reactor was charged with 250.6 g (0.203 mol) PIBSA (made
from 1000 MW PIB reacted with maleic anhydride), 251.1 g caromax 20
and 56.0 g toluene. The mixture was heated to 95.degree. C. and
55.2 g (0.406 mol) aminoguanidine bicarbonate added slowly over 1
hour. The temperature was increased to 165.degree. C. and held for
3 hours to remove water. Toluene was removed under vacuum.
EXAMPLE 8
[0281] Additive Q1, a quaternary ammonium salt additive was
prepared as follows:
[0282] 33.9 kg (27.3 moles) of a polyisobutyl-substituted succinic
anhydride having a PIB molecular weight of 1000 was heated to
90.degree. C. 2.79 kg (27.3 moles) dimethylaminopropylamine was
added and the mixture stirred at 90 to 100.degree. C. for 1 hour.
The temperature was increased to 140.degree. C. for 3 hours with
concurrent removal of water. 25 kg of 2-ethyl hexanol was added,
followed by 4.15 kg methyl salicylate (27.3 moles) and the mixture
maintained at 140.degree. C. for 9.5 hours.
EXAMPLE 9
[0283] Additive Q2, a quaternary ammonium salt was prepared as
follows:
[0284] A reactor was charged with 687.0 g (0.312 mol) PIBSI (made
from 1000 MW PIB reacted with maleic anhydride, diluted in Caromax
20 then further reacted with DMAPA) and 205.99 g methanol. 35.6 ml
(0.312 mol) styrene oxide and 18.64 g (0.312 mol) acetic acid were
added. The mixture was heated to reflux for 5 hours. Methanol was
removed under vacuum.
EXAMPLE 10
[0285] To a mixture of 1000 MW PIS-substituted phenol (300 g) in
toluene (400 ml), at 50.degree. C. was charged dimethylamine (40%
solution in water, 26 g), followed by paraformaldehyde (7.2 g). The
reaction was heated at 60.degree. C. for 1 hour then to 120.degree.
C. for 4 hours with removal of water using Dean-Stark distillation.
The product was cooled to below 50.degree. C. and the toluene
removed on a rotary evaporator to leave a pale orange clear viscous
liquid (308.1 g).
EXAMPLE 11
[0286] Additive Q3, a quaternary ammonium salt was prepared as
follows:
[0287] 41.45 g (32.6 mMol) of the mannich reaction product prepared
in example 10, methyl salicylate (5.00 g, 32.9 mMol) and
2-ethylhexanol (32.37 g, 41 wt % of total charge) were mixed with
stirring under nitrogen and heated at 136.degree. C. overnight.
After 16 hours the reaction mixture was allowed to cool to below
80.degree. C. and decanted, hot, to suitable storage and sample
jars.
EXAMPLE 12
[0288] To a mixture of 1000 PIB-Chloride (300 g) in Xylenes (400
ml) at 50.degree. C. was added Dimethylaminopropylamine (DMAPA, 70
g, 2.3 mole equivalents). The reaction was heated to reflux
(140.degree. C.) for 5 hours. The product was cooled to below
50.degree. C. and Sodium Hydroxide (50% m/m, 50 g) was added and
mixed for 1 hour at 50.degree. C. The mixture was transferred to a
separating funnel with water (200 ml) and the organics separated
after two days. The organics were washed with further water
(2.times.200 ml), dried over anhydrous MgSO.sub.4 and filtered. The
Xylenes were removed on a rotary evaporator to leave a dark
brown/black viscous liquid (305.6 g).
EXAMPLE 13
[0289] Additive Q4 a quaternary ammonium salt was prepared as
follows:
[0290] 40.50 g (26 mMol) of the polyisobutylamine prepared in
example 12, methyl salicylate (4.07 g, 26.7 mMol) and
2-ethylhexanol (29.54 g, 40 wt % of total charge) were mixed with
stirring under nitrogen and heated at 140-141.degree. C. overnight.
After 16 hours the flask contents were allowed to cool to below
80.degree. C. and decanted, hot, to suitable storage and sample
jars.
EXAMPLE 14
[0291] Additive compositions F1 to F8 were prepared by mixing 50:50
ratios by weight of the crude products from examples 3-11 as
identified table 1.
TABLE-US-00004 TABLE 1 Q1 Q2 Q3 Q4 A1 F1 A2 F2 F4 F7 F8 B1 F5 C1 F6
D1 F3
EXAMPLE 15
[0292] Fuel Compositions were prepared by adding 160 ppm by weight
of the crude product from examples 3-12 in a common batch of RF06
basefuel.
[0293] Table 2 below shows the specification for RF06 base
fuel.
TABLE-US-00005 TABLE 2 Limits Property Units Min Max Method Cetane
Number 52.0 54.0 EN ISO 5165 Density at 15.degree. C. kg/m.sup.3
833 837 EN ISO 3675 Distillation 50% v/v Point .degree. C. 245 --
95% v/v Point .degree. C. 345 350 FBP .degree. C. -- 370 Flash
Point .degree. C. 55 -- EN 22719 Cold Filter Plugging .degree. C.
-- -5 EN 116 Point Viscosity at 40.degree. C. mm.sup.2/sec 2.3 3.3
EN ISO 3104 Polycyclic Aromatic % m/m 3.0 6.0 IP 391 Hydrocarbons
Sulphur Content mg/kg -- 10 ASTM D 5453 Copper Corrosion -- 1 EN
ISO 2160 Conradson Carbon % m/m -- 0.2 EN ISO 10370 Residue on 10%
Dist. Residue Ash Content % m/m -- 0.01 EN ISO 6245 Water Content %
m/m -- 0.02 EN ISO 12937 Neutralisation (Strong mg KOH/g -- 0.02
ASTM D 974 Acid) Number Oxidation Stability mg/mL -- 0.025 EN ISO
12205 HFRR (WSD1,4) .mu.m -- 400 CEC F-06-A-96 Fatty Acid Methyl
Ester prohibited
EXAMPLE 16
[0294] Fuel compositions as detailed in table 3 were prepared by
dosing quaternary ammonium salt additives of the present invention
into an RF06 base fuel meeting the specification given in table 2
(example 15) above. The effectiveness of these compositions in
older engine types was assessed using the CEC test method No. CEC
F-23-A-01, as described in example 2.
TABLE-US-00006 TABLE 3 Additive1 Additive2 XUD-9 (ppm of crude (ppm
of crude % Average Flow Composition product) product) Loss None
None 78.5 1 D1 (240) 69.0 2 D1 (80) Q1 (80) 16.8
* * * * *