U.S. patent application number 10/634291 was filed with the patent office on 2005-04-28 for composition.
Invention is credited to Green, Derek Richard, Henry, Cyrus Pershing, Pinch, David Leonard, Sneddon, Andrea.
Application Number | 20050086856 10/634291 |
Document ID | / |
Family ID | 9949770 |
Filed Date | 2005-04-28 |
United States Patent
Application |
20050086856 |
Kind Code |
A1 |
Henry, Cyrus Pershing ; et
al. |
April 28, 2005 |
Composition
Abstract
The present invention provides a jet fuel composition comprising
(i) a jet fuel; (ii) a compound of Formula I 1 wherein m is at
least 1; wherein n is 0 or 1; wherein when m is 1, n is 0; wherein
the or each R.sub.1 is a hydrocarbyl group with the proviso that
the or each R.sub.1 is free of carboxylic acid and carboxylic ester
groups; and wherein when m is 1, R.sub.1 is a polymeric group
comprising at least 12 carbon atoms.
Inventors: |
Henry, Cyrus Pershing;
(Wilmington, DE) ; Pinch, David Leonard; (Wirral,
GB) ; Sneddon, Andrea; (Wirral, GB) ; Green,
Derek Richard; (Preston, GB) |
Correspondence
Address: |
Scott A. McCollister
Fay, Sharpe, Fagan, Minnich & McKee LLP
7th Floor
1100 Superior Avenue
Cleveland
OH
44114-2518
US
|
Family ID: |
9949770 |
Appl. No.: |
10/634291 |
Filed: |
August 5, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60401568 |
Aug 6, 2002 |
|
|
|
Current U.S.
Class: |
44/421 ;
44/450 |
Current CPC
Class: |
C10L 1/14 20130101; C10L
1/2283 20130101; C10L 1/1981 20130101; C10L 1/2608 20130101; C10L
1/1835 20130101; C10L 1/2225 20130101; C10L 1/198 20130101; C10L
1/1832 20130101 |
Class at
Publication: |
044/421 ;
044/450 |
International
Class: |
C10L 001/22; C10L
001/18 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 16, 2002 |
GB |
GB 0229286.0 |
Claims
1. A jet fuel composition comprising (i) a jet fuel; and (ii) a
compound of Formula I 22wherein m is at least 1; wherein n is 0 or
1; wherein when m is 1, n is 0; wherein the or each R.sub.1 is a
hydrocarbyl group with the proviso that the or each R.sub.1 is free
of carboxylic acid and carboxylic ester groups; and wherein when m
is 1, R.sub.1 is a polymeric group comprising at least 12 carbon
atoms.
2. A jet fuel composition according to claim 1 further comprising
(iii) an antioxidant.
3. A jet fuel composition according to claim 1 further comprising
(iv) a metal deactivator.
4. A jet fuel composition according to wherein m is 1.
5. A jet fuel composition according to claim 1 wherein R.sub.1 is a
hydrocarbon group.
6. A jet fuel composition according to claim 1 wherein R.sub.1 is a
linear or branched alkyl group.
7. A jet fuel composition according to claim 1 wherein R.sub.1 is a
C.sub.1-C.sub.200 group.
8. A jet fuel composition according to claim 1 wherein R.sub.1 is a
C.sub.10-C.sub.200 group.
9. A jet fuel composition according to claim 1 wherein R.sub.1 is a
C.sub.40-C.sub.180 group.
10. A jet fuel composition according to claim 1 wherein R.sub.1 is
a branched alkyl group.
11. A jet fuel composition according to claim 1 wherein R.sub.1 is
a polyalkenyl group.
12. A jet fuel composition according to claim 1 wherein R.sub.1 is
polyisobutene (PIB).
13. A jet fuel composition according to claim 1 wherein R.sub.1 has
a molecular weight of from 200 to 2500.
14. A jet fuel composition according to claim 1 wherein R.sub.1 has
a molecular weight of 500 to 2500.
15. A jet fuel composition according to claim 1 wherein R.sub.1 has
a molecular weight of approximately 750.
16. A jet fuel composition according to claim 1 wherein R.sub.1 has
a molecular weight of approximately 1000.
17. A jet fuel composition according to claim 1 wherein R.sub.1 has
a molecular weight of approximately 2300.
18. A jet fuel composition according to claim 1 comprising (i) a
jet fuel (ii) a compound of Formula I 23wherein m is 1 and n is 0;
wherein R.sub.1 is a polyisobutene with a molecular weight of from
200 to 2500; (iii) an antioxidant; and (iv) a metal
deactivator.
19. A jet fuel composition according to claim 1 wherein m is
greater than 1.
20. A jet fuel composition according to claim 19 wherein R.sub.1 is
a hydrocarbon group.
21. A jet fuel composition according to claim 19 wherein R.sub.1 is
a linear or branched alkyl group.
22. A jet fuel composition according to claim 19 wherein R.sub.1 is
a C.sub.1-C.sub.50 group.
23. A jet fuel composition according to claim 19 wherein R.sub.1 is
a C.sub.1-C.sub.25 group.
24. A jet fuel composition according to claim 19 wherein R.sub.1 is
a C.sub.5-C.sub.15 group.
25. A jet fuel composition according to claim 19 wherein m is at
least 4.
26. A jet fuel composition according to claim 19 comprising (i) a
jet fuel (ii) a compound of Formula I 24wherein m is greater than 1
and n is 1; wherein each R.sub.1 is a C.sub.1-C.sub.50 hydrocarbyl
group free of carboxylic acid and carboxylic ester groups. (iii) an
antioxidant; and (iv) a metal deactivator.
27. A jet fuel composition according to claim 18 wherein R.sub.1 is
para substituted relative to the OH group.
28. A jet fuel composition according to claim 18 wherein the
(CH.sub.2).sub.n group is ortho substituted relative to the OH
group.
29. A jet fuel composition according to claim 2 wherein the
antioxidant is a hindered phenol antioxidant.
30. A jet fuel composition according to claim 29 wherein the
antioxidant is 2,6-di-t-butyl-4-methyl phenol (BHT).
31. A jet fuel composition according to claim 2 wherein the
antioxidant is a phosphonate.
32. A jet fuel composition according to claim 31 wherein the
antioxidant is dilauryl phosphonate.
33. A jet fuel composition according to claim 3 wherein the metal
deactivator is N,N'-disalicylidene 1,2-propanediamine.
34. A jet fuel composition according to claim 1 wherein the
compound of Formula I is present in an amount of 50-200 mg/L.
35. A jet fuel composition according to claim 1 wherein the
compound of Formula I is present in an amount of 80-120 mg/L.
36. A jet fuel composition according to claim 2 wherein the
antioxidant is present in an amount of 1-50 mg/L.
37. A jet fuel composition according to claim 36 wherein the
antioxidant is present in an amount of 1-30 mg/L.
38. A jet fuel composition according to claim 3 wherein the metal
deactivator is present in an amount of 0.05-10 mg/L.
39. A jet fuel composition according to claim 38 wherein the metal
deactivator is present in an amount of 0.5-5 mg/L.
40. A jet fuel composition according to claim 1 wherein the
compound of Formula I is a compound of Formula II 25wherein the or
each R.sub.2 is an optional hydrocarbyl group with the proviso that
the or each R.sub.2 is free of carboxylic acid and carboxylic ester
groups; and wherein m, n and R.sub.1 are as defined in any one of
the preceding claims.
41. Use of a compound of Formula I as defined in claim 1 for the
inhibition of oxidation of a jet fuel composition as defined in any
one of the preceding claims.
42. Use of a compound of Formula I as defined in claim 1 for the
inhibition of deposit formation in a jet fuel composition as
defined in any one of the preceding claims.
43. Use of a compound of Formula I as defined in claim 1 for the
inhibition of particulate formation from the oxidation product(s)
of a jet fuel composition as defined in any one of the preceding
claims.
44. Use of a compound of Formula I as defined in claim 1 for the
solubilisation of deposits and/or deposit precursors in a jet fuel
composition as defined in any one of the preceding claims.
45. A method for inhibiting deposit formation in a jet fuel at a
temperature of from 100 to 335.degree. C., the method comprising
combining with the jet fuel a compound of Formula I 26wherein m is
at least 1; wherein n is 0 or 1; wherein when m is 1, n is 0;
wherein the or each R.sub.1 is a hydrocarbyl group with the proviso
that the or each R.sub.1 is free of carboxylic acid and carboxylic
ester groups; and wherein when m is 1, R.sub.1 is a polymeric group
comprising at least 12 carbon atoms.
46. (canceled)
47. (canceled)
48. (canceled)
49. (canceled)
Description
[0001] The present invention relates to a composition. In
particular, the present invention relates to a jet fuel composition
comprising a deposit inhibiting compound.
[0002] Hydrocarbon fuels, such as fuels boiling in the gasoline
boiling range, kerosene, middle distillate fuels, home heating oils
etc. are known to exhibit certain undesirable characteristics such
as the formation of solid deposits. These undesirable
characteristics may develop more readily during prolonged periods
of storage or when the hydrocarbon fuel remains at a high
temperature over a period of time, for example during use.
[0003] As discussed in U.S. Pat. No. 5,621,154, turbine combustion
fuel oils i.e. jet fuels, such as JP-4, JP-5, JP-7, JP-8, Jet A,
Jet A-1 and Jet B are ordinarily middle boiling distillates, such
as kerosene or combinations of naphtha and kerosene. Military grade
JP-4, for instance, is used in military aircraft and is a possible
blend of naphtha and kerosene. Military grades JP-7 and JP-8 are
primarily highly refined kerosenes, as are Jet A and Jet A-1, which
are used for commercial aircraft. Civil grades of jet fuel are
defined in ASTM D1655, DefStan 91-91, and other similar
specifications. Such jet fuel are produced from a variety of
sources including crude oil, oil sands, oil shales, Fischer Tropsch
processes and gas to liquid processes. Refinery processing includes
fuels produced by straight distillation, sometimes processed by
chemical sweetening, or hydrogen processing including hydrocracking
operations, and may contain <1 to 3000 ppm sulphur.
[0004] As discussed in WO 99/25793, in high speed aircraft, both
civilian and military, liquid fuel is combusted to produce power,
but is also circulated in the aircraft as a heat exchange fluid to
remove the excess heat generated at such speeds e.g. in lubricating
oils. In current aircraft, bulk fuel temperatures may be raised to
as high as 425.degree. F. at the inlet to the mainburner fuel
nozzles and above 500.degree. F. inside the fuel nozzle passages.
In the augmentor or afterburner systems, skin temperatures up to
1100.degree. F. are experienced. In future aircraft, these
temperatures are expected to be 100.degree. F. higher. The fuel is
thus maintained for long periods at high temperatures.
[0005] At these high temperatures (425.degree. F.-1100.degree. F.)
and oxygen-rich atmospheres in aircraft and engine fuel system
components, the fuel discolours and decomposes to produce soluble
coloured products and insoluble products such as gums, sediments
and granular material. These insoluble products can form deposits
that reduce the heat exchange capacity and plug-up the components
leading to operational problems including reduced thrust and
performance anomalies in the augmentor, poor spray patterns and
premature failure of mainburner combustors and problems with fuel
controls. Further, the engine exhaust becomes smoky and sooty and
engine noise increases, both of which are undesirable
characteristics for jet engines.
[0006] Detergent additives for inhibiting the oxidation of
hydrocarbons and liquid hydrocarbon fuels and for inhibiting
deposit formation in engines have been proposed.
[0007] U.S. Pat. No. 3,849,085 discloses a motor fuel composition
for a spark-ignited reciprocating internal combustion engine
containing a high molecular weight aliphatic hydrocarbon
substituted or alkylated phenol in which the aliphatic hydrocarbon
radical has a molecular weight in the range from about 500 to 3,500
effective to prevent or inhibit intake manifold and intake valve
and port deposits. The base fuel of the invention comprises a
mixture of hydrocarbons boiling in the gasoline boiling range.
[0008] U.S. Pat. No. 5,221,461 discloses a method for inhibiting
fouling during the elevated temperature processing of hydrocarbons
comprising adding to the hydrocarbons a composition comprising a
catechol having the structure 2
[0009] wherein R is H and C.sub.1-C.sub.10 alkyl and, an organic
acid.
[0010] WO-A-99/25793 discloses compounds which are taught to be
thermal stabilising additives for fuels comprising kerosene and jet
fuels. The compounds are oil soluble macromolecules and comprise a
hydroxy-carboxylic acid functionality. Typically compounds of
WO-A-99/25793 are of the formula 3
[0011] wherein Y.sup.1 and Y.sup.2 are divalent bridging groups,
which may be the same or different; R.sup.3 is hydrogen, a
hydrocarbyl or a hetero-substituted hydrocarbyl group; each of
R.sup.1, R.sup.2 and R.sup.4, which may be the same or different,
is hydroxyl, hydrogen, hydrocarbyl or hetero-substituted
hydrocarbyl, with the proviso that at least one of R.sup.1,
R.sup.2, R.sup.4 is hydroxyl, and m+n is 4 to 20, m is 1-8 and n is
at least 3.
[0012] The present invention alleviates the problems of the prior
art.
[0013] In one aspect the present invention provides a jet fuel
composition comprising (i) a jet fuel and (ii) a compound of
Formula I 4
[0014] wherein m is at least 1; wherein n is 0 or 1; wherein when m
is 1, n is 0; wherein the or each R.sub.1 is a hydrocarbyl group
with the proviso that the or each R.sub.1 is free of carboxylic
acid and carboxylic ester groups; and wherein when m is 1, R.sub.1
is a polymeric group comprising at least 12 carbon atoms.
[0015] In one aspect the present invention provides use of a
compound of Formula I as herein defined for:
[0016] the inhibition of oxidation of a jet fuel composition as
herein defined
[0017] the inhibition of deposit formation in a jet fuel
composition as herein defined
[0018] the inhibition of particle formation from the oxidation
product(s) of a jet fuel composition as herein defined
[0019] the solubilisation of deposits and/or deposit precursors in
a jet fuel composition as herein defined.
[0020] In one aspect the present invention provides a method for
inhibiting deposit formation in a jet fuel at a temperature of from
100 to 335.degree. C., the method comprising combining with the jet
fuel a compound of Formula I 5
[0021] wherein m is at least 1; wherein n is 0 or 1; wherein when m
is 1, n is 0; wherein the or each R.sub.1 is a hydrocarbyl group
with the proviso that the or each R.sub.1 is free of carboxylic
acid and carboxylic ester groups; and wherein when m is 1, R.sub.1
is a polymeric group comprising at least 12 carbon atoms.
[0022] It has surprisingly been found that a jet fuel composition
according to the present invention has improved properties as
compared to a jet fuel. In particular, it has been found that
compounds of Formula I are capable of inhibiting deposit and/or
particle formation in a jet fuel composition. The present compounds
may also be capable of inhibiting the pre-combustion oxidation of a
jet fuel composition. Furthermore, compounds of Formula I are
capable of improving the solubility of deposits and/or deposit
precursors in a jet fuel composition. Addition of a compound of
Formula I to a jet fuel may typically improve the properties of the
jet fuel such that it meets industry standards, for example those
relating to deposit formation. The improvements to a jet fuel on
addition of a compound of Formula I may be studied for example
using the Isothermal Corrosion Oxidation Test (ICOT) apparatus
following Protocol I set out below and/or the Hot Liquid Process
Simulator (HLPS) apparatus following Protocol II set out below.
[0023] The term "jet fuel composition" as used herein relates to a
fuel suitable for use as an aviation fuel. In particular, the term
"jet fuel composition" relates to a fuel complying with at least
one of
[0024] ASTM D 1655 Specification for Aviation Turbine Fuels
[0025] Defence Stan 91-91 Turbine Fuel, Aviation Kerosene Type, Jet
A-1
[0026] NATO code F-35, F-34, F-37
[0027] Aviation Fuel Quality Requirements for Jointly Operated
Systems (Joint
[0028] Checklist) A combination of ASTM and Def Stan
requirements
[0029] GOST 10227 Jet Fuel Specifications (Russia)
[0030] Canadian CAN/CGSB-3.22 Aviation Turbine Fuel, Wide Cut
Type
[0031] Canadian CAN/CGSB-3.23 Aviation Turbine Fuel, Kerosene
Type
[0032] MIL-DTL-83133, JP-8
[0033] MIL-DTL-5624, JP-4, JP-5
[0034] QAV-1 (Brazil) Especifcacao de Querosene de Aviacao
[0035] No. 3 Jet Fuel (Chinese) according to GB6537
[0036] DCSEA 134A (France) Carbureacteur Pour Turbomachines
D'Aviation, Type Kerosene
[0037] Aviation Turbine Fuels of other countries, meeting the
general grade requirements for Jet A, Jet A-1, Jet B, and TS-1
fuels as described in the IATA Guidance Material for Aviation
Turbine Fuel Specifications.
[0038] The term "jet fuel" as used herein relates to a liquid
hydrocarbon fuel.
[0039] The jet fuel typically comprises paraffins as a major
component and may comprise aromatics and naphthenes. The main
component of the jet fuel is usually a middle boiling distillate
having a boiling point in the range 150-300.degree. C. at
atmospheric pressure. The jet fuel may comprise mixtures of naphtha
and light petroleum distillate, e.g. in weight amounts of
20-80:80-20 such as 50-75:50-25 which weight amounts may also be
used for mixtures of naphtha and kerosene.
[0040] The jet fuels for military use are designated JP-4 to 8 e.g.
JP-4 as 65% naphtha/35% light petroleum distillate (according to US
Mil. Spec. (MIL 5624G)), JP-5, a kerosene fuel but of higher flash
point, JP-7, a high flash point special kerosene for advanced
supersonic aircraft and JP-8, a kerosene similar to Jet AI
(according to MIL 83133C).
[0041] Jet fuel for civilian use is usually a kerosene type fuel
and designated Jet A or Jet AI Jet Fuel No.3 TS-1. The jet fuel may
have a boiling point of 66-343.degree. C. or 66-316.degree. C.
(150-650.degree. F. e.g. 150-600.degree. F.), initial boiling point
of 149-221.degree. C., e.g. 204 C (300-430.degree. F., e.g.
400.degree. F.), a 50% boiling point of 221-316.degree. C.
(430-600.degree. F.) and a 90% boiling point of 260-343.degree. C.
(500-650.degree. F.) and API Gravity of 30-40. Jet fuel for
turbojet use may boil at 93-260.degree. C. (200-500.degree. F.)
(ASTM D1655-006).
[0042] Further details on aviation fuels may be obtained from
"Handbook of Aviation Fuel Properties", Co-ordinating Research
Council Inc., CRC Report No. 530 (Society of Automotive Engineers
Inc., Warrendale, Pa., USA, 1983) and on US military fuels, from
"Military Specification for Aviation Turbine Fuels",
MIL-T-5624P.
[0043] The jet fuel may be the straight run kerosene optionally
with added gasoline (naphtha), but frequently has been purified to
reduce its content of components contributing to or encouraging
formation of coloured products and/or precipitates. Among such
components are aromatics, olefins, mercaptans, phenols and various
nitrogen compounds. Thus the jet fuel may be purified to reduce its
mercaptan content e.g. Merox fuel and copper sweetened fuel or to
reduce its sulphur content e.g. hydrogen treated fuel or Merifined
fuel.
[0044] Merox fuels are made by oxidation of the mercaptans and have
a low mercaptan S content (e.g. less than 0.005% wt S) such as
0.0001-0.005% but a higher disulphide S content (e.g. at most 0.4%
or at most 0.3% wt S such as 0.05-0.25 e.g. 0.1-2%); their aromatic
(e.g. phenolics) and olefins content are hardly changed. Hydrogen
processed jet fuels are ones in which the original fuel has been
hydrogenated to remove at least some of sulphur compounds e.g.
thiols and under severe conditions to saturate the aromatics and
olefins; hydrofined jet fuels have very low sulphur contents (e.g.
less than 0.01% S by weight). Merifined fuels are fuels that have
been extracted with an organic extractant to reduce or remove their
contents of sulphur compounds and/or phenols.
[0045] The jet fuel may also contain metals, either following
contact with metal pipes or carried over from the crude oil, oil
sands, shale oil or sources; examples of such metals are copper,
nickel, iron and chromium usually in amounts of less than 1 ppm
e.g. each in 10-150 ppb amounts.
[0046] Merox, straight run and hydrogen processed are preferred and
may be used in JP-4-8 jet fuels.
[0047] The jet fuel composition of the present invention may
contain at least one conventional additive for jet fuels such as an
antioxidant, a corrosion inhibitor, a lubricity improver, a metal
deactivators (MDA), a leak detection additive, a "special purpose"
additive such as a drag reducing agent, an anti-icing additive and
a static dissipater such as Stadis.RTM., especially in amounts of
1-2000 ppm each.
[0048] The term "hydrocarbyl" as used herein relates to a group
comprising at least C and H that may optionally comprise one or
more other suitable substituents. Examples of such substituents may
include halo-, alkoxy-, nitro-, an alkyl group, or a cyclic group.
In addition to the possibility of the substituents being a cyclic
group, a combination of substituents may form a cyclic group. If
the hydrocarbyl group comprises more than one C then those carbons
need not necessarily be linked to each other. For example, at least
two of the carbons may be linked via a suitable element or group.
Thus, the hydrocarbyl group may contain heteroatoms. Suitable
heteroatoms will be apparent to those skilled in the art and
include, for instance, sulphur, nitrogen, oxygen, silicon and
phosphorus.
[0049] Any substituent is preferably inert under the reaction
conditions employed in the preparation of the compounds of Formula
I and preferably should not give unfavourable interactions with the
jet fuel or other additives employed in the jet fuel composition.
Substituents meeting these conditions will be readily apparent to a
person skilled in the art.
[0050] There is a proviso that the or each R.sub.1 is free of
carboxylic acid and carboxylic ester groups. The term carboxylic
acid refers to the functional group --COOH and the term carboxylic
ester refers to the functional group --COOR wherein R is a
C.sub.1-6 alkyl group.
[0051] Hydrocarbon jet fuels are known to be subject to
deterioration when in contact with oxygen, either on standing in
air or, more importantly during pre-combustion heating. Such
deterioration is thought to be due to the presence in the fuel of
constituents that undergo oxidative changes resulting in the
formation of non-volatile resinous substances. In addition, the
high temperatures and oxygen-rich atmospheres in aircraft and
engine fuel system components encourage the degradation of the jet
fuel resulting in particulate formation. The resinous substances
and particulates may typically be insoluble and may therefore be
deposit precursors. These deposit precursors may unfavourably
agglomerate and/or form deposits. Additionally, the particulates
may collect in filters leading to partial or total blockage of such
filters. Such deposits once formed may undergo further pyrolysis
and oxidation.
[0052] The term "inhibition of oxidation of a jet fuel composition"
as used herein means reducing the rate of one or more oxidative
reactions and/or preventing one or more oxidative reactions as
compared to a jet fuel not containing a compound of Formula I. It
will be readily understood that by the term oxidation is meant
pre-combustion oxidation.
[0053] The term "inhibition of deposit formation in a jet fuel
composition" as used herein means a reduction of the mass of
deposit formed under prescribed conditions over a prescribed period
of time as compared to a jet fuel not containing a compound of
Formula I.
[0054] The term "inhibition of particulate formation from the
oxidation product(s) of a jet fuel composition" as used herein
means a reduction in particulate formation formed under prescribed
conditions over a prescribed period of time as compared to a jet
fuel not containing a compound of Formula I.
[0055] The term "solubilisation of deposits and/or deposit
precursors in a jet fuel composition" as used herein means
increasing the solubility of deposits and/or deposit precursors
under prescribed conditions as compared to a jet fuel not
containing a compound of Formula I.
PREFERRED EMBODIMENTS
[0056] As previously mentioned, in one aspect the present invention
provides a jet fuel composition comprising (i) a jet fuel and (ii)
a compound of Formula I 6
[0057] wherein m is at least 1; wherein n is 0 or 1; wherein when m
is 1, n is 0; wherein the or each R.sub.1 is a hydrocarbyl group
with the proviso that the or each R.sub.1 is free of carboxylic
acid and carboxylic ester groups; and wherein when m is 1, R.sub.1
is a polymeric group comprising at least 12 carbon atoms.
[0058] Antioxidant
[0059] In one aspect, the present invention provides a jet fuel
composition further comprising (iii) an antioxidant.
[0060] The term "antioxidant" as used herein means a substance
capable of reducing the rate of one or more oxidative reactions
and/or preventing one or more oxidative reactions.
[0061] In one aspect, preferably the antioxidant is a hindered
phenol antioxidant. By the term "hindered phenol" is meant a
compound comprising a phenol moiety wherein the aromatic ring of
the phenol moiety is substituted by at least one hydrocarbyl group.
The at least one hydrocarbyl group is preferably ortho to the
hydroxy group of the phenol moiety. The at least one hydrocarbyl
group is preferably a hydrocarbon group, more preferably an alkyl
group, more preferably a branched alkyl group.
[0062] Preferably the antioxidant is 2,6-di-t-butyl-4-methyl phenol
(BHT). 7
[0063] Other preferred antioxidants include
[0064] 2,6-ditertiary butyl phenol
[0065] 2,4-dimethyl-6-tertiary butyl phenol
[0066] mixtures of 2,6-ditertiary butyl phenol, and tertiary and
tritertiary butyl phenols, such as 75% minimum 2,6-ditertiary butyl
phenol/25% maximum tertiary and tritertiary butyl phenols
[0067] mixtures of 2,4-dimethyl-6 tertiary butyl phenol,
4-methyl-2,6-ditertiary butyl phenol, monomethyl-tertiary butyl
phenols and dimethyl-tertiary butyl phenols, such as 55% minimum
2,4-dimethyl-6 tertiary butyl phenol/15% minimum
4-methyl-2,6-ditertiary butyl phenol/remainder 30% maximum as a
mixture of monomethyl and dimethyl-tertiary butyl phenols
[0068] mixtures of 2,4-dimethyl-6-tertiary butyl phenol, tertiary
butyl methyl phenols and tertiary butyl dimethyl phenols, such as
72% minimum 2,4-dimethyl-6-tertiary butyl phenol/28% maximum
mixture of tertiary butyl methyl phenols and tertiary butyl
dimethyl phenols.
[0069] In one aspect the antioxidant of the present invention is a
phosphorus-containing antioxidant.
[0070] Preferably the phosphorus-containing antioxidant is an
organophosphorus-containing antioxidant.
[0071] By the term "organophosphorus-containing antioxidant" it is
meant a compound comprising at least P and C and may optionally
comprise one or more other suitable atoms. Examples of such atoms
may include hydrogen, sulphur and oxygen. Preferably the
organophosphorus-containing antioxidant is a compound containing a
C--P bond and/or a C--O--P bond and/or a C--S--P bond.
[0072] Preferably the phosphorus-containing antioxidant is or is
derived from an organophosphorus acid. Preferably the
organophosphorus acid is selected from phosphorus acid, phosphonous
acid, phosphinous acid, phosphoric acid, phosphonic acid or
phosphinic acid.
[0073] In one preferred aspect the phosphorus-containing
antioxidant is or is derived from an ester of an organophosphorus
acid. Preferably the organophosphorus acid is selected from
phosphorus acid, phosphonous acid, phosphinous acid, phosphoric
acid, phosphonic acid or phosphinic acid.
[0074] In a preferred aspect the phosphorus-containing antioxidant
is an ester of an organophosphorus acid. More preferably the
phosphorus-containing antioxidant is an ester of an
organophosphorus acid selected from phosphorus acid, phosphonous
acid, phosphinous acid, phosphoric acid, phosphonic acid or
phosphinic acid.
[0075] In a highly preferred aspect the phosphorus-containing
antioxidant is or is an ester of a phosphonic acid. In a highly
preferred aspect the phosphorus-containing antioxidant is an ester
of a phosphonic acid.
[0076] In one aspect, preferably the antioxidant is a
phosphonate.
[0077] In a preferred aspect the antioxidant is of the formula
8
[0078] wherein x and y are independently selected from 1 to 15,
preferably 5 to 15, preferably 7 to 13, preferably 8 to 12,
preferably 9, 10 or 11.
[0079] In a highly preferred aspect the antioxidant is of the
formula 9
[0080] This compound is commonly known as di-dodecyl hydrogen
phosphonate or dilauryl phosphonate.
[0081] Metal Deactivator
[0082] In another aspect, the present invention provides a jet fuel
composition further comprising (iv) a metal deactivator.
[0083] Preferably the metal deactivator is a substance capable of
chelating to at least one metal ion. More preferably the metal
deactivator is N,N'-disalicylidene 1,2-propanediamine. 10
[0084] In one preferred aspect the present invention provides a jet
fuel composition further comprising (iii) an antioxidant and (iv) a
metal deactivator. Preferably, the present invention provides a jet
fuel composition further comprising (iii) an antioxidant and (iv)
N,N'-disalicylidene 1,2-propanediamine.
[0085] In one preferred aspect the present invention provides a jet
fuel composition further comprising (iii) 2,6-di-t-butyl-4-methyl
phenol (BHT) and (iv) N,N'-disalicylidene 1,2-propanediamine.
[0086] In one preferred aspect the present invention provides a jet
fuel composition further comprising (iii) dilauryl phosphonate
(DLP) and (iv) N,N'-disalicylidene 1,2-propanediamine.
[0087] Compound of Formula I
[0088] As previously mentioned, in one aspect the present invention
provides a jet fuel composition comprising (i) a jet fuel and (ii)
a compound of Formula I 11
[0089] wherein m is at least 1; wherein n is 0 or 1; wherein when m
is 1, n is 0; wherein the or each R.sub.1 is a hydrocarbyl group
with the proviso that the or each R.sub.1 is free of carboxylic
acid and carboxylic ester groups; and wherein when m is 1, R.sub.1
is a polymeric group comprising at least 12 carbon atoms.
[0090] In one preferred aspect, m is 1 or at least 3. In this
aspect preferably m is 1 or 3 to 50, such as 1 or 3 to 20, 1 or 3
to 10, or 1 or 3 to 8. In a highly preferred aspect, m is 1 or 3 to
5. In this aspect, preferably m is 1 or 3 or 4. In one aspect, m is
1 or 3. In another aspect, m is 1 or at least 4, preferably m is 1
or 4.
[0091] In one preferred aspect m is 1.
[0092] In this aspect, preferably R.sub.1 is a hydrocarbon
group.
[0093] The term "hydrocarbon" as used herein means any one of an
alkyl group, an alkenyl group, an alkynyl group, an acyl group,
which groups may be linear, branched or cyclic, or an aryl group.
The term hydrocarbon also includes those groups but wherein they
have been optionally substituted. If the hydrocarbon is a branched
structure having substituent(s) thereon, then the substitution may
be on either the hydrocarbon backbone or on the branch;
alternatively the substitutions may be on the hydrocarbon backbone
and on the branch.
[0094] In this aspect, preferably R.sub.1 is a linear or branched
alkyl group.
[0095] In this aspect, preferably R.sub.1 is a C.sub.1-C.sub.200
group, preferably a C.sub.1-C.sub.180 group, preferably a
C.sub.10-C.sub.200 group, preferably a C.sub.20-C.sub.200 group,
preferably a C.sub.30-C.sub.200 group, preferably a
C.sub.40-C.sub.200 group, preferably a C.sub.10-C.sub.180 group,
preferably a C.sub.20-C.sub.180 group, preferably a
C.sub.30-C.sub.180 group, more preferably a C.sub.40-C.sub.180
group.
[0096] In this aspect, preferably R.sub.1 is a branched alkyl
group. Preferably, R.sub.1 is a polyalkenyl group. Preferably the
polyalkenyl is a polymer of a C.sub.2 to C.sub.6 alkenyl group,
more preferably a C.sub.4 alkenyl group.
[0097] Preferably R.sub.1 is polyisobutene (PIB).
[0098] Conventional PIBs and so-called "high-reactivity" PIBs (see
for example EP 0565285) are suitable for use in the invention. High
reactivity in this context is defined as a PIB wherein at least
50%, preferably 70% or more, of the terminal olefinic double bonds
are of the vinylidene type.
[0099] In this aspect, preferably R.sub.1 has a molecular weight of
from 200 to 2500, preferably from 500 to 2500, more preferably from
600 to 2400 such as approximately 750 or approximately 1000 or
approximately 2300.
[0100] In one preferred embodiment, the present invention provides
a jet fuel composition comprising
[0101] (i) a jet fuel
[0102] (ii) a compound of Formula I 12
[0103] wherein m is 1 and n is 0;
[0104] wherein R.sub.1 is a polyisobutene with a molecular weight
of from 200 to 2500;
[0105] (iii) an antioxidant; and
[0106] (iv) a metal deactivator.
[0107] As previously mentioned, in one aspect the present invention
provides a jet fuel composition comprising (i) a jet fuel and (ii)
a compound of Formula I 13
[0108] wherein m is at least 1; wherein n is 0 or 1; wherein when m
is 1, n is 0; wherein the or each R.sub.1 is a hydrocarbyl group
with the proviso that the or each R.sub.1 is free of carboxylic
acid and carboxylic ester groups; and wherein when m is 1, R.sub.1
is a polymeric group comprising at least 12 carbon atoms.
[0109] In one preferred aspect m is greater than 1. In this aspect
preferably n is 1. Preferably m is at least 4, or is from 3 to 5,
more preferably m is 4.
[0110] In this aspect, preferably R.sub.1 is a hydrocarbon group,
more preferably a linear or branched alkyl group.
[0111] In this aspect, preferably R.sub.1 is a C.sub.1-C.sub.50
group, preferably a C.sub.1-C.sub.40 group, preferably a
C.sub.1-C.sub.30 group, preferably a C.sub.1-C.sub.25 group,
preferably a C.sub.1-C.sub.15 group. A typical example of R.sub.1
is a dodecyl group.
[0112] In this aspect, preferably R.sub.1 is a C.sub.5-C.sub.50
group, preferably a C.sub.5-C.sub.40 group, preferably a
C.sub.5-C.sub.30 group, preferably a C.sub.5-C.sub.25 group,
preferably a C.sub.5-C.sub.15 group such as a C.sub.5-C.sub.10
group or a C.sub.10-C.sub.15 group or a C.sub.12 group.
[0113] In one preferred embodiment, the present invention provides
a jet fuel composition comprising
[0114] (i) a jet fuel
[0115] (ii) a compound of Formula I 14
[0116] wherein m is greater than 1 and n is 1;
[0117] wherein each R.sub.1 is a C.sub.1-C.sub.50 hydrocarbyl group
free of carboxylic acid and carboxylic ester groups.
[0118] (iii) an antioxidant; and
[0119] (iv) a metal deactivator.
[0120] In one preferred aspect R.sub.1 is para substituted relative
to the OH group.
[0121] In one preferred aspect the (CH.sub.2).sub.n group is ortho
substituted relative to the OH group.
[0122] Preferably R.sub.1 is para substituted relative to the OH
group and the (CH.sub.2).sub.n group is ortho substituted relative
to the OH group.
[0123] In one broad aspect n of the compound of the present
invention may be other than 0 or 1. For example n may be from 0 to
10 such as 0 to 8, 0 to 5 or 0, 1, 2 or 3.
[0124] It will appreciated by one skilled in the art that the each
of the "units" of Formula I may contain one or more further
substituents. The "units" of Formula I independently of each other
may be optionally substituted. In a preferred aspect at least one
of the "units" is unsubstituted. In a further preferred aspect each
of the "units" is unsubstituted. A typical optional substituent may
be a hydrocarbyl group.
[0125] Thus, in one aspect, the compound of Formula I is a compound
of Formula II 15
[0126] wherein the or each R.sub.2 is an optional hydrocarbyl group
with the proviso that the or each R.sub.2 is free of carboxylic
acid and carboxylic ester groups; and wherein m, n and R.sub.1 are
as herein defined.
[0127] There is a proviso that the or each R.sub.2 is free of
carboxylic acid and carboxylic ester groups. The term carboxylic
acid refers to the functional group --COOH and the term carboxylic
ester refers to the functional group --COOR wherein R is a
C.sub.1-6 alkyl group.
[0128] In this aspect preferably R.sub.2 is an optional hydrocarbon
group, more preferably an optional linear or branched alkyl
group.
[0129] In this aspect, preferably R.sub.2 is a C.sub.1-C.sub.50
group, preferably a C.sub.1-C.sub.40 group, preferably a
C.sub.1-C.sub.30 group, preferably a C.sub.1-C.sub.25 group,
preferably a C.sub.1-C.sub.15 group.
[0130] A typical example of R.sub.2 is a tertiary alkyl group, such
as a tertiary butyl group.
[0131] When m is greater than 1, one or more of the terminal units
of the compound of Formula may be substituted. A preferred
substituent for a terminal units is a Mannich Group. Thus in a
preferred aspect the present invention provides a compound on the
formula 16
[0132] wherein R1 and m are as defined herein and p is from 1 to
10, 1 to 5, or 1, 2 or 3.
[0133] Composition
[0134] In one preferred aspect, the compound of Formula I is
present in the jet fuel composition in an amount of 1-500 mg/L,
preferably 1-400 mg/L, preferably 1-300 mg/L, preferably 1-200
mg/L. In a preferred aspect, the compound of Formula I is present
in the jet fuel composition in an amount of 5-200 mg/L, preferably
10-200 mg/L, preferably 25-200 mg/L, preferably 50-200 mg/L,
preferably 50-150 mg/L, more preferably 80-120 mg/L.
[0135] In one aspect, the jet fuel composition of the present
invention further comprises (iii) an antioxidant.
[0136] Preferably the antioxidant is present in the jet fuel
composition in an amount of 1-50 mg/L preferably 1-40 mg/L,
preferably 1-30 mg/L such as 1-25 mg/L or 1-15 mg/L.
[0137] In one aspect, the jet fuel composition of the present
invention further comprises (iv) a metal deactivator.
[0138] Preferably the metal deactivator is present in an amount of
0.05 to 10 mg/L, preferably 0.05 to 8 mg/L, preferably 0.05 to 5
mg/L, preferably 0.1 to 5 mg/L preferably 0.3 to 5 mg/L, preferably
0.5 to 5 mg/L such as 1 mg/L, 2 mg/L or 3 mg/L.
[0139] Use
[0140] As previously mentioned, in one aspect the present invention
provides use of a compound of Formula I as herein defined for:
[0141] the inhibition of oxidation of a jet fuel composition as
herein defined
[0142] the inhibition of deposit formation in a jet fuel
composition as herein defined
[0143] the inhibition of particle formation from the oxidation
product(s) of a jet fuel composition as herein defined
[0144] the solubilisation of deposits and/or deposit precursors in
a jet fuel composition as herein defined.
[0145] As previously discussed, hydrocarbon jet fuels are known to
be subject to deterioration when in contact with oxygen, especially
during pre-combustion heating. During pre-combustion heating the
jet fuel composition typically reaches temperatures of from 25 to
335.degree. C., such as from 50 to 335.degree. C., or from 100 to
335.degree. C., for example from 150 to 335.degree. C., such as
from 180 to 335.degree. C. or from 150 to 260.degree. C.
[0146] Thus, in a preferred aspect, the present invention provides
use of a compound of Formula I as herein defined for
[0147] the inhibition of oxidation of a jet fuel composition as
herein defined at temperatures of from 25 to 335.degree. C.,
preferably from 50 to 335.degree. C., more preferably from 100 to
335.degree. C. such as from 150 to 335.degree. C., or from 180 to
335.degree. C. or from 150 to 260.degree. C.;
[0148] the inhibition of deposit formation in a jet fuel
composition as herein defined at temperatures of from 25 to
335.degree. C., preferably from 50 to 335.degree. C., more
preferably from 100 to 335.degree. C. such as from 150 to
335.degree. C., or from 180 to 335.degree. C. or from 150 to
260.degree. C.;
[0149] the inhibition of particle formation from the oxidation
product(s) of a jet fuel composition as herein defined at
temperatures of from 25 to 335.degree. C., preferably from 50 to
335.degree. C., more preferably from 100 to 335.degree. C. such as
from 150 to 335.degree. C., or from 180 to 335.degree. C. or from
150 to 260.degree. C.;
[0150] the solubilisation of deposits and/or deposit precursors in
a jet fuel composition as herein defined at temperatures of from 25
to 335.degree. C., preferably from 50 to 335.degree. C., more
preferably from 100 to 335.degree. C. such as from 150 to
335.degree. C., or from 180 to 335.degree. C. or from 150 to
260.degree. C.
[0151] Method
[0152] As previously mentioned, in one aspect the present invention
provides a method for inhibiting deposit formation in a jet fuel at
a temperature of from 100 to 335.degree. C., the method comprising
combining with the jet fuel a compound of Formula I as herein
defined.
[0153] In a broad aspect, the present invention provides a method
for inhibiting deposit formation in a jet fuel at a temperature of
from 25 to 335.degree. C., the method comprising combining with the
jet fuel a compound of Formula I as herein defined.
[0154] In a preferred embodiment, the present invention provides a
method for inhibiting deposit formation in a jet fuel at a
temperature of from 25 to 335.degree. C., preferably from 50 to
335.degree. C., more preferably from 100 to 335.degree. C. such as
from 150 to 335.degree. C., or from 180 to 335.degree. C. or from
150 to 260.degree. C., the method comprising combining with the jet
fuel a compound of Formula I as herein defined.
[0155] Highly Preferred Aspects
[0156] As previously mentioned, in one aspect the present invention
provides a jet fuel composition comprising (i) a jet fuel and (ii)
a compound of Formula I 17
[0157] wherein m is at least 1; wherein n is 0 or 1; wherein when m
is 1, n is 0; wherein the or each R.sub.1 is a hydrocarbyl group
with the proviso that the or each R.sub.1 is free of carboxylic
acid and carboxylic ester groups; and wherein when m is 1, R.sub.1
is a polymeric group comprising at least 12 carbon atoms.
[0158] In one preferred aspect, the present invention provides a
jet fuel composition comprising (i) a jet fuel and (ii) a compound
of Formula I wherein m is 1; n is 0; and R.sub.1 is a polymeric
hydrocarbyl group comprising at least 12 carbon atoms, with the
proviso that R.sub.1 is free of carboxylic acid and carboxylic
ester groups.
[0159] In one preferred aspect, the present invention provides a
jet fuel composition comprising (i) a jet fuel and (ii) a compound
of Formula I wherein m is 1; n is 0; and R.sub.1 is a polymeric
hydrocarbon group comprising at least 12 carbon atoms.
[0160] In one preferred aspect, the present invention provides a
jet fuel composition comprising (i) a jet fuel and (ii) a compound
of Formula I wherein m is 1; n is 0; and R.sub.1 is a polymeric
linear or branched alkyl group, preferably a polymeric branched
alkyl group, comprising at least 12 carbon atoms.
[0161] In one preferred aspect, the present invention provides a
jet fuel composition comprising (i) a jet fuel and (ii) a compound
of Formula I wherein m is 1; n is 0; and R.sub.1 is a polyisobutene
(PIB) comprising at least 12 carbon atoms.
[0162] In one preferred aspect, the present invention provides a
jet fuel composition comprising (i) a jet fuel and (ii) a compound
of Formula I wherein m is 1; n is 0; and R.sub.1 is a polyisobutene
(PIB) with a molecular weight of from 200 to 2500.
[0163] In one preferred aspect, the present invention provides a
jet fuel composition comprising (i) a jet fuel and (ii) a compound
of Formula I wherein m is 1; n is 0; and R.sub.1 is a polyisobutene
(PIB) with a molecular weight of from 500 to 2500.
[0164] In one preferred aspect, the present invention provides a
jet fuel composition comprising (i) a jet fuel and (ii) a compound
of Formula I wherein m is 1; n is 0; and R.sub.1 is a polyisobutene
(PIB) with a molecular weight of from 600 to 2400.
[0165] In one preferred aspect, the present invention provides a
jet fuel composition comprising (i) a jet fuel and (ii) a compound
of Formula I wherein m is 1; n is 0; and R.sub.1 is a polyisobutene
(PIB) with a molecular weight of about 750.
[0166] In one preferred aspect, the present invention provides a
jet fuel composition comprising (i) a jet fuel and (ii) a compound
of Formula I wherein m is 1; n is 0; and R.sub.1 is a polyisobutene
(PIB) with a molecular weight of about 1000.
[0167] In one preferred aspect, the present invention provides a
jet fuel composition comprising (i) a jet fuel and (ii) a compound
of Formula I wherein m is 1; n is 0; and R.sub.1 is a polyisobutene
(PIB) with a molecular weight of about 2300.
[0168] In a further aspect the present invention provides a jet
fuel composition comprising (i) a jet fuel and (ii) a compound of
Formula I 18
[0169] wherein m is at least 3; wherein n is 0 or 1; and wherein
each R.sub.1 is a hydrocarbyl group with the proviso that each
R.sub.1 is free of carboxylic acid and carboxylic ester groups.
[0170] In a further aspect the present invention provides a jet
fuel composition comprising (i) a jet fuel and (ii) a compound of
Formula I wherein m is at least 3; wherein n is 1; and wherein each
R.sub.1 is a hydrocarbon group.
[0171] In a further aspect the present invention provides a jet
fuel composition comprising (i) a jet fuel and (ii) a compound of
Formula I wherein m is at least 3; wherein n is 1; and wherein each
R.sub.1 is a C.sub.1-50 hydrocarbon group, preferably a
C.sub.1-C.sub.40 group, preferably a C.sub.1-C.sub.30 group,
preferably a C.sub.1-C.sub.25 group, preferably a C.sub.1-C.sub.15
group.
[0172] In a further aspect the present invention provides a jet
fuel composition comprising (i) a jet fuel and (ii) a compound of
Formula I wherein m is at least 3; wherein n is 1; and wherein each
R.sub.1 is a C.sub.1-50 linear or branched alkyl group, preferably
a C.sub.1-C.sub.40 group, preferably a C.sub.1-C.sub.30 group,
preferably a C.sub.1-C.sub.25 group, preferably a C.sub.1-C.sub.15
group.
[0173] In a further aspect the present invention provides a jet
fuel composition comprising (i) a jet fuel and (ii) a compound of
Formula I wherein m is at least 3; wherein n is 1; and wherein each
R.sub.1 is a C.sub.1-C.sub.15 branched alkyl group.
[0174] In a further aspect the present invention provides a jet
fuel composition comprising (i) a jet fuel and (ii) a compound of
Formula I wherein m is 3; wherein n is 1; and wherein each R.sub.1
is a C.sub.1-50 hydrocarbon group, preferably a C.sub.1-C.sub.40
group, preferably a C.sub.1-C.sub.30 group, preferably a
C.sub.1-C.sub.25 group, preferably a C.sub.1-C.sub.15 group.
[0175] In a further aspect the present invention provides a jet
fuel composition comprising (i) a jet fuel and (ii) a compound of
Formula I wherein m is 3; wherein n is 1; and wherein each R.sub.1
is a C.sub.1-50 linear or branched alkyl group, preferably a
C.sub.1-C.sub.40 group, preferably a C.sub.1-C.sub.30 group,
preferably a C.sub.1-C.sub.25 group, preferably a C.sub.1-C.sub.15
group.
[0176] In a further aspect the present invention provides a jet
fuel composition comprising (i) a jet fuel and (ii) a compound of
Formula I wherein m is 3; wherein n is 1; and wherein each R.sub.1
is a C.sub.1-15 branched alkyl group.
[0177] In a further aspect the present invention provides a jet
fuel composition comprising (i) a jet fuel and (ii) a compound of
Formula I wherein m is 4; wherein n is 1; and wherein each R.sub.1
is a C.sub.1-50 hydrocarbon group, preferably a C.sub.1-C.sub.40
group, preferably a C.sub.1-C.sub.30 group, preferably a
C.sub.1-C.sub.25 group, preferably a C.sub.1-C.sub.15 group.
[0178] In a further aspect the present invention provides a jet
fuel composition comprising (i) a jet fuel and (ii) a compound of
Formula I wherein m is 4; wherein n is 1; and wherein each R.sub.1
is a C.sub.1-50 linear or branched alkyl group, preferably a
C.sub.1-C.sub.40 group, preferably a C.sub.1-C.sub.30 group,
preferably a C.sub.1-C.sub.25 group, preferably a C.sub.1-C.sub.15
group.
[0179] In a further aspect the present invention provides a jet
fuel composition comprising (i) a jet fuel and (ii) a compound of
Formula I wherein m is 4; wherein n is 1; and wherein each R.sub.1
is a C.sub.1-C.sub.15 branched alkyl group.
[0180] In another aspect the present invention provides a jet fuel
composition comprising (i) a jet fuel and (ii) a compound of
Formula II 19
[0181] wherein m is at least 3; wherein n is 0 or 1; wherein each
R.sub.1 is a hydrocarbyl group with the proviso that each R.sub.1
is free of carboxylic acid and carboxylic ester groups; and wherein
each R.sub.2 is an optional hydrocarbyl group with the proviso that
each R.sub.2 is free of carboxylic acid and carboxylic ester
groups.
[0182] In another aspect the present invention provides a jet fuel
composition comprising (i) a jet fuel and (ii) a compound of
Formula II, wherein m is at least 3; wherein n is 1; wherein each
R.sub.1 is a hydrocarbon group and wherein each R.sub.2 is an
optional hydrocarbon group.
[0183] In another aspect the present invention provides a jet fuel
composition comprising (i) a jet fuel and (ii) a compound of
Formula II, wherein m is at least 3; wherein n is 1; wherein each
R.sub.1 is a C.sub.1-50 hydrocarbon group, preferably a
C.sub.1-C.sub.40 group, preferably a C.sub.1-C.sub.30 group,
preferably a C.sub.1-C.sub.25 group, preferably a C.sub.1-C.sub.15
group; and wherein each R.sub.2 is an optional C.sub.1-50
hydrocarbon group, preferably a C.sub.1-C.sub.40 group, preferably
a C.sub.1-C.sub.30 group, preferably a C.sub.1-C.sub.25 group,
preferably a C.sub.1-C.sub.15 group.
[0184] In another aspect the present invention provides a jet fuel
composition comprising (i) a jet fuel and (ii) a compound of
Formula II, wherein m is at least 3; wherein n is 1; wherein each
R.sub.1 is a C.sub.1-50 linear or branched alkyl group, preferably
a C.sub.1-C.sub.40 group, preferably a C.sub.1-C.sub.30 group,
preferably a C.sub.1-C.sub.25 group, preferably a C.sub.1-C.sub.15
group; and wherein each R.sub.2 is an optional Cl.sub.50 linear or
branched alkyl group, preferably a C.sub.1-C.sub.40 group,
preferably a C.sub.1-C.sub.30 group, preferably a C.sub.1-C.sub.25
group, preferably a C.sub.1-C.sub.15 group.
[0185] In another aspect the present invention provides a jet fuel
composition comprising (i) a jet fuel and (ii) a compound of
Formula II, wherein m is at least 3; wherein n is 1; wherein each
R.sub.1 is a C.sub.1-15 linear or branched alkyl group; and wherein
each R.sub.2 is an optional C.sub.1-15 linear or branched alkyl
group.
[0186] In another aspect the present invention provides a jet fuel
composition comprising (i) a jet fuel and (ii) a compound of
Formula II, wherein m is 3; wherein n is 1; wherein each R.sub.1 is
a C.sub.1-50 hydrocarbon group, preferably a C.sub.1-C.sub.40
group, preferably a C.sub.1-C.sub.30 group, preferably a
C.sub.1-C.sub.25 group, preferably a C.sub.1-C.sub.15 group; and
wherein each R.sub.2 is an optional C.sub.1-50 hydrocarbon group,
preferably a C.sub.1-C.sub.40 group, preferably a C.sub.1-C.sub.30
group, preferably a C.sub.1-C.sub.25 group, preferably a
C.sub.1-C.sub.15 group.
[0187] In another aspect the present invention provides a jet fuel
composition comprising (i) a jet fuel and (ii) a compound of
Formula II, wherein m is 3; wherein n is 1; wherein each R.sub.1 is
a C.sub.1-50 linear or branched alkyl group, preferably a
C.sub.1-C.sub.40 group, preferably a C.sub.1-C.sub.30 group,
preferably a C.sub.1-C.sub.25 group, preferably a C.sub.1-C.sub.15
group; and wherein each R.sub.2 is an optional C.sub.1-50 linear or
branched alkyl group, preferably a C.sub.1-C.sub.40 group,
preferably a C.sub.1-C.sub.30 group, preferably a C.sub.1-C.sub.25
group, preferably a C.sub.1-C.sub.15 group.
[0188] In another aspect the present invention provides a jet fuel
composition comprising (i) a jet fuel and (ii) a compound of
Formula II, wherein m is 3; wherein n is 1; wherein each R.sub.1 is
a C.sub.1-15 linear or branched alkyl group; and wherein each
R.sub.2 is an optional C.sub.1-15 linear or branched alkyl
group.
[0189] In another aspect the present invention provides a jet fuel
composition comprising (i) a jet fuel and (ii) a compound of
Formula II, wherein m is 3; wherein n is 1; wherein each R.sub.1 is
a C.sub.1-15 tertiary alkyl group, preferably a tertiary butyl
group; and wherein each R.sub.2 is an optional C.sub.1-15 tertiary
alkyl group, preferably a tertiary butyl group.
[0190] In another aspect the present invention provides a jet fuel
composition comprising (i) a jet fuel and (ii) a compound of
Formula II, wherein m is 4; wherein n is 1; wherein each R.sub.1 is
a C.sub.1-50 hydrocarbon group, preferably a C.sub.1-C.sub.40
group, preferably a C.sub.1-C.sub.30 group, preferably a
C.sub.1-C.sub.25 group, preferably a C.sub.1-C.sub.15 group; and
wherein each R.sub.2 is an optional C.sub.1-50 hydrocarbon group,
preferably a C.sub.1-C.sub.40 group, preferably a C.sub.1-C.sub.30
group, preferably a C.sub.1-C.sub.25 group, preferably a
C.sub.1-C.sub.15 group.
[0191] In another aspect the present invention provides a jet fuel
composition comprising (i) a jet fuel and (ii) a compound of
Formula II, wherein m is 4; wherein n is 1; wherein each R.sub.1 is
a C.sub.1-50 linear or branched alkyl group, preferably a
C.sub.1-C.sub.40 group, preferably a C.sub.1-C.sub.30 group,
preferably a C.sub.1-C.sub.25 group, preferably a C.sub.1-C.sub.15
group; and wherein each R.sub.2 is an optional C.sub.1-50 linear or
branched alkyl group, preferably a C.sub.1-C.sub.40 group,
preferably a C.sub.1-C.sub.30 group, preferably a C.sub.1-C.sub.25
group, preferably a C.sub.1-C.sub.15 group.
[0192] In another aspect the present invention provides a jet fuel
composition comprising (i) a jet fuel and (ii) a compound of
Formula II, wherein m is 4; wherein n is 1; wherein each R.sub.1 is
a C.sub.1-15 linear or branched alkyl group; and wherein each
R.sub.2 is an optional C.sub.1-15 linear or branched alkyl
group.
[0193] In another aspect the present invention provides a jet fuel
composition comprising (i) a jet fuel and (ii) a compound of
Formula II, wherein m is 4; wherein n is 1; wherein each R.sub.1 is
a C.sub.1-15 tertiary alkyl group, preferably a tertiary butyl
group; and wherein each R.sub.2 is an optional C.sub.1-15 tertiary
alkyl group, preferably a tertiary butyl group.
[0194] Aspects of the invention are defined in the appended claims.
The present invention will now be described in further detail by
way of example only with reference to the accompanying figures in
which:--
[0195] FIG. 1 shows the Isothermal Corrosion Oxidation Test (ICOT)
apparatus; and
[0196] FIG. 2 shows the Hot Liquid Process Simulator (HLPS)
apparatus.
[0197] The present invention will now be described in further
detail in the following examples.
EXAMPLES
[0198] Syntheses
[0199] Preparation of Polyisobutene-Substituted Phenol
1 Polyisobutene-Substituted Phenol A Compound of Formula I 20
[0200] The following synthetic route is described in
EP-A-0831141.
[0201] 203.2 g (2.16 mol) of phenol was melted at 40.degree. C. and
added to boron trifluoride etherate (73.5 ml, 0.60 mol) in a 5
litre round bottomed flask. Ultravis.TM. 10 (1040 g, 1.09 mol), a
"highly reactive" polyisobutene (PiB) (Mw=1000), was dissolved in
hexane (1863 ml) and the solution added to the flask containing the
phenol via a pressure equalising dropping funnel, at a rate
sufficient to maintain the temperature of the reaction mixture at
22-27.degree. C. This took three hours. The solution was stirred
for a further 16 hours at room temperature before ammonia (400 ml
of 30% w/w aqueous, 2.88 mol) was added. The solution turned a deep
blue colour. 1000 ml of water was added and the mixture stirred,
after which it was separated in a five litre separating funnel and
the aqueous layer extracted with 4.times.500 ml hexane. The organic
layers were combined and dried over MgSO.sub.4 overnight, then
filtered through a 12 mm Celite pad. The solvent was removed from
the filtrate at 80.degree. C./23"Hg on a rotary evaporator. The
product was found to comprise polyisobutene-substituted phenol with
a para to ortho ratio of about 3:1.
[0202] Preparation of Alkylated Phenol Resins
[0203] The resin is a simple condensation product of an alkyl
phenol with formaldehyde or other lower aldehydes. The condensate
can be prepared by reacting an alkylphenol with formaldehyde in the
presence of an alkali catalyst and optionally a solvent suitable to
aid the removal of water azeotropically.
[0204] For example, a C15-20 alkyl phenol (500 g) was mixed with
NaOH (5 g) and heated to 93.degree. C. for 45 minutes. On cooling
paraformaldehyde (34.6 g) was added and the reactants heated to
115.degree. C. to remove water. Solvent was added and the solution
washed with acid and water to remove NaOH.'
[0205] An alkylated phenol resin was prepared from 2,6-ditertiary
butyl phenol (2,6DTBP) and 2-tertiary butyl phenol (2TBP). The
reaction product was a mixture of trimer products with two main
trimer products based on 2,6DTBP-2TBP-2,6DTBP. A sample structure
of such a trimer product is: 21
[0206] The reaction product also contained minor products based on
2,6DTBP-2TBP-2TBP and 2TBP-2TBP-2TBP. This alkylated phenol resin
is named Phenol Resin 2 in the test results below.
[0207] Test Protocols
[0208] The deposit inhibiting compounds according to the present
invention were tested as jet fuel additives using the ICOT and the
HLPS. Protocols for these two tests are set out below.
Protocol I--ICOT
[0209] Scope--The ICOT is used to investigate the effectiveness of
additives in jet fuel. This is carried out by stressing base and
additised fuels at constant temperature with a controlled volume of
air flowing though the sample. On cooling, the fuels are filtered
and the thermal stability is measured by the weight of solid on a
filter.
[0210] Summary--The ICOT is run under the following conditions, 100
ml of fuel is stressed at 180.degree. C. with an air flow of 1.3
litres/hour for 5 hours. The fuel sample is then left to cool for
16 hours. The cooled fuel is then filtered using a 0.7 to 1 .mu.m
glass microfibre filter. The weight of solid on the filter is a
measurement of the fuels thermal stability under stress. By
comparing base fuels to additised fuels, the effectiveness of
different additives can be compared.
[0211] Apparatus--See ASTM Method D4871-88 for description of
apparatus. The filter to be used is a 0.7 to 1 .mu.m glass
micro-fibre filter. For cleaning of glassware a furnace anneals the
glass inlet tubes and the test cell at 600.degree. C. Filtration is
done under suction using an appropriate funnel.
[0212] Materials
[0213] Base fuels--fuels not containing additives
[0214] Additised fuels--base fuels that have been treated with a
specified additive or additive package.
[0215] Preparation--Clean glassware must be used for each
experiment. The cleaning of the glass inlet tubes and the test
cells is done by annealing in a furnace at 600.degree. C. then
allowing cooling in air. The condensers are washed out with acetone
with a small brush and wiped to ensure that no fuel residues are
present, then allowed to dry in air.
[0216] Test Procedure
[0217] 1. Turn heating block on and allow to heat up to a constant
temperature of 180.degree. C.
[0218] 2. Number test cells and place in corresponding sites.
[0219] 3. Inlet tubes and condensers are set up as shown in FIG.
3
[0220] 4. Sites 1-5 are used for test fuel samples. Place 100 mls
of test fuel in each cell by carefully releasing the condenser and
inserting a glass funnel.
[0221] 5. Repeat for site 6 using a control fuel.
[0222] 6. Set the flows for each site to 1.3 It/hour by adjusting
the glass bead floats. (Refer to calibration chart for correct
setting.
[0223] 7. Reflux the fuels for 5 hours at 180.degree. C.
[0224] 8. After the 5 hours remove the inlet tubes and
condensers.
[0225] 9. Remove the test cells and place in a suitable stand.
[0226] 10. Allow to cool for 16 hours (overnight).
[0227] 11. Place all used glassware in furnace for cleaning.
[0228] 12. For each sample pre-weigh a 0.7-1 .mu.m glass
micro-fibre filter. Place the test cells in a ultrasonic bath for 3
minutes to release any deposit adhered to the sides of the cell,
then filter the fuel under vacuum. Rinse the test cell rinsed with
heptane or 2-2-4 trimethylpentane and also filter.
[0229] 13. Place the filters on petri dishes and dry in a oven at
60.degree. C. for 3 hours
[0230] 14. Re-weigh the filter papers and perform the calculation
below.
[0231] Calculation--The information is required in mg per litre. 1
( weight of filter with deposits in g ) - ( weight of filter in g )
.times. 1000 ( 0.1 litre )
Protocol II--HLPS
[0232] Scope--HLPS is a self-contained testing apparatus designed
to test the thermal properties of base and additised jet fuels. The
test involves the flow of the test fuel over a heated test surface
(at 335.degree. C.) under high pressure (500 psi).
[0233] Summary--The HLPS is run in accordance with ASTM D-3241. The
conditions for testing are set to those used by the USAF in
extensive thermal stability programmes.
[0234] The basic principles of the HLPS are shown in FIG. 2. As
shown in FIG. 2, 1 litre of test fuel is pressurised in a stainless
steel reservoir to 500 psi. The fuel is then pumped via a
pre-filter over a heated test section (at 335.degree. C.). As
deposition occurs on both the tube and in the fuel bulk the bulk
deposit is measured as a filter drop change across a 17 micron
filter. A pressure transducer cell measures the rate of pressure
drop (in mmHg min.sup.-1). Finally the spent fuel is returned to
the top of the reservoir, separated by an appropriate seal.
[0235] Apparatus
[0236] Alcor HLPS is a modular version of the equipment set up as
defined in ASTM D-3241. The test section must be of stainless steel
316 and free from grease. The filter to be used must be of 17
micron mesh as supplied by Alcor.
[0237] Materials
[0238] Base fuels--fuels free of additives
[0239] Additised fuels--base fuels that have been treated with a
specified additive or additive package.
[0240] Main Test Procedure
[0241] Sample Preparation:
[0242] 1. Filter 1 litre of base test fuel through a 0.7 micron
filter.
[0243] 2. If fuel is to be additised transfer the known weight of
additive(s) to a 1 litre volumetric flask using base test fuel.
[0244] 3. Transfer the test fuel to a 2 litre beaker. Aerate using
the glass bubbler attachment for a minimum of 6 minutes. Test run
must be initiated within 1 hour of aeration.
[0245] 4. Transfer the test fuel to the stainless steel
reservoir.
[0246] 5. Check the piston seal for degradation. If OK place the
piston head on the surface of the fuel and push down using the
supplied handle until fuel begins to seep up from the
reservoir.
[0247] 6. Place the large `O` ring seal in the reservoir top and
secure to the top of the reservoir using a socket wrench.
[0248] 7. Connect the connector tube from the filter unit to the
test cell using new `O` ring.
[0249] 8. Connect all remaining pipe-work using new `O` rings.
[0250] Main Test Run Procedure:
[0251] 1. Close BLEED valve on front of HLPS and open PRESSURISE
valve. Ensure that system is pressurised to 500 psi.
[0252] 2. Ensure that lower knob on delta P cell is turned to
BYPASS and upper knob is VENT CLOSED.
[0253] 3. Switch on PUMP. Red indicator light will come on. Ensure
that FUEL FLOW CONTROL is set to 230. This equates to a flow rate
of 3 mls/min.
[0254] 4. Allow fuel to pump round system until a steady drop rate
is seen through the perspex window on top of the fuel reservoir.
When steady, count the time taken for 20 drops. If the time is 9
secs. +/-1 second this is acceptable for 3 mls/min.
[0255] 5. Ensure that HEATER TUBE TEMP. CONTROL is set to
335.degree. C. Switch on HEATER. Red indicator light will come on.
Needle will then rise to the vertical. Heater power is controlled
by using the POWER CONTROL dial. A typical setting for this
procedure is 82+/-10 volts.
[0256] 6. Switch on the differential pressure module (DPM) by
depressing the POWER button.
[0257] 7. When needle reads correct temperature switch the delta P
lower knob to RUN. This will divert the fuel flow through the
differential pressure cell.
[0258] 8. Allow the pressure read out on the differential pressure
module to equilibrate and press RECORD. The differential pressure
will be recorded every 5 minutes on the in-built printer.
[0259] 9. Allow the test to run whilst monitoring the differential
pressure change. The DPM has an alarm setting that will cause
multi-point printing at 125 mmHg. If the differential pressure
rises above 300 mmHg turn the lower DPM knob to bypass and note the
time.
[0260] 10. In all cases allow the test run to complete a 5 hour
test sequence. The HLPS will shut down automatically after 5
hours.
[0261] Analysis--Analysis is carried out on the Leco Carbon
Analyser RC412.
[0262] Results
[0263] The results are quoted as 2 readings.
[0264] Filter blockage--Record the change in differential pressure
during the run. Results are quoted in mmHg min.sup.-1, e.g. 300/45,
0/300. The first figure is the change in differential pressure in
mmHg the latter the time in minutes
[0265] Carbon deposit weight--Record the value in
.mu.gcm.sup.-2.
[0266] Results
[0267] ICOT
[0268] A number of different jet fuels were tested using the ICOT.
The jet fuels were tested in the absence of additives, in the
presence of an antioxidant and a metal deactivator (MDA) and in the
presence of an antioxidant, an MDA and a variety of deposit
inhibiting compounds of the present invention. The antioxidant, the
MDA and the deposit inhibiting compounds were used in the following
concentrations:
2 Antioxidant 25 mg/l active ingredient MDA 2 mg/l active
ingredient Deposit inhibiting compound 100 mg/l active ingredient
The antioxidant used was 2,6-di-t-butyl-4-methyl phenol (BHT). Test
Sample Mass of deposit in each fuel - mg/l Deposit POSF POSF
inhibiting 3684 3219 Shell Antioxidant MDA compound Shell HT (USAF
B) (USAF A) BP Merox Merox -- -- -- 124 112 81 24 35 BHT MDA -- 70
34 -- -- -- BHT MDA PIB phenol 97 47 -- -- -- (750 mwt) BHT MDA PIB
phenol 62 33 22 19 9 (1000 mwt) BHT MDA PIB phenol 63 18 33 10 8
(2300 mwt) BHT MDA Phenol 63 25 27 3 5 resin BHT MDA Phenol 56 31
33 5 3 resin Mannich
[0269] In the following test the antioxidant, the MDA and the
deposit inhibiting compounds were used in the following
concentrations:
3 Antioxidant 25 mg/l active ingredient MDA 2 mg/l active
ingredient Deposit inhibiting compound 10 mg/l active ingredient
Test Sample Deposit Mass of deposit in each inhibiting fuel - mg/l
Antioxidant MDA compound Shell HT BHT MDA Phenol 45 resin 2
[0270] In the following test the antioxidant, the MDA and the
deposit inhibiting compounds were used in the following
concentrations:
4 Antioxidant 25 mg/l active ingredient MDA 2 mg/l active
ingredient Deposit inhibiting compound 50 mg/l active ingredient
Test Sample Deposit Mass of deposit in each inhibiting fuel - mg/l
Antioxidant MDA compound Shell HT BHT MDA Phenol 24 resin 2
[0271] These data shows that there is a reduction in the mass of
deposit recorded for test samples comprising a deposit inhibiting
compound of the present invention as compared with the test sample
comprising base fuel alone.
[0272] HLPS
[0273] HLPS was used to test a base fuel in the absence of
additives, in the presence of an antioxidant and a metal
deactivator (MDA) and in the presence of an antioxidant, an MDA and
a variety of deposit inhibiting compounds of the present invention.
The antioxidant, the MDA and the deposit inhibiting compounds were
used in the following concentrations:
5 Antioxidant 10 mg/l active ingredient MDA 2 mg/l active
ingredient Deposit inhibiting compound 100 mg/l active ingredient
The antioxidant used was dilauryl phosphonate (DLP). Test Sample
Shell HT USAF B USAF A Deposit .DELTA.P Carbon .DELTA.P Carbon
.DELTA.P Carbon inhibiting (mmHg/ Burn off (mmHg/ Burn off (mmHg/
Burn off Antioxidant MDA compound min) (.mu.g/cm.sup.2) min)
(.mu.g/cm.sup.2) min) (.mu.g/cm.sup.2) -- -- -- 300/230 39 300/45
125 300/148 95 DLP -- -- 3/300 86.5 -- -- -- -- -- MDA -- 0/300 62
-- -- -- -- DLP MDA -- 2/300 21 -- -- -- -- -- -- Phenol 2/300 45
-- -- -- -- resin DLP MDA Phenol 0/300 12 300/255 24 4/300 28 resin
DLP MDA PIB phenol 3/300 11 -- -- -- -- (1000 mwt) DLP MDA PIB
phenol 0/300 9 300/158 23 66/300 28 (2300 mwt) Phenol 0/300 20
112/300 24 0/300 28 resin Mannich
[0274] These data shows that test samples comprising a deposit
inhibiting compound of the present invention have reduced filter
block as compared with the base fuel. Test samples comprising a
combination of a deposit inhibiting compound, an antioxidant and a
metal deactivator according to the present invention have reduced
filter block and reduced carbon burn-off as compared with the base
fuel.
[0275] All publications mentioned in the above specification are
herein incorporated by reference. Various modifications and
variations of the described methods and system of the invention
will be apparent to those skilled in the art without departing from
the scope and spirit of the invention. Although the invention has
been described in connection with specific preferred embodiments,
it should be understood that the invention as claimed should not be
unduly limited to such specific embodiments. Indeed, various
modifications of the described modes for carrying out the invention
which are obvious to those skilled in chemistry or related fields
are intended to be within the scope of the following claims.
* * * * *