US20130074398A1

US20130074398A1 - Aviation fuel

Info

Publication number: US20130074398A1
Application number: US13/700,787
Authority: US
Inventors: Theis Brock-Nannestad; Anne Sophie Vinther Hansen
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-05-30
Filing date: 2011-05-30
Publication date: 2013-03-28
Also published as: EP2576736A1; EP2576736A4; WO2011150924A1

Abstract

A jet aviation fuel based on aliphatic ethers is disclosed wherein the fuel comprises a compound according to the invention, a mixture of compounds according to the invention, a mixture of the pure or mixed aliphatic ethers admixed with conventional jet aviation fuel, or a mixture of said ethers with conventional hydrocarbon fuel, thus giving a product conforming to a jet aviation fuel standard.

Description

This application is an international application claiming priority from Danish patent application no. PA2010 00471. All patent and non-patent references cited in the present application, are hereby incorporated by reference in their entirety.

FIELD OF INVENTION

The present invention relates to the field of fuels, specifically aviation fuels for use in jet engines.

BACKGROUND OF INVENTION

Aviation fuel specifications are among the most restrictive among all fuel specifications, reflecting the combination of extreme temperatures encountered during flight, and the consequence of failure characteristic of the aviation industry. A car engine failing may be a major nuisance whereas the failure of a plane engine can lead to disaster. As a consequence of these fuel specifications are stringent, rarely changed and in general based on a very cautious approach towards modification. The same viewpoint is reflected in implementation of e.g. new engine technologies be that jet or internal combustion engines.
Chief requirements according to jet aviation fuel specifications are concerned with performance at low temperature, imposed to reduce the risk of fuel lines clogging due to precipitation of compounds at low temperature. Commercial jet aviation fuel is a complex mixture of hydrocarbons, varying according to production locale and feedstock, all complying with common specifications.
Currently, offerings in bio-fuels are either bio-ethanol, which do not live up to current engine technology as ethanol is hygroscopic, cannot form homogenous mixtures with jet aviation fuel and that lastly have an energy density that is approximately 70% of current jet aviation fuel. Other fuel types are bio-Diesel, made by the transesterification of fatty materials be that from plants or from animal sources. The long chain esters composing bio-Diesel are only partially compatible with current use in jet aviation, not only due to unfavourable physical properties, but also due to the fact that ester hydrolysis can lead to clogging of fuel lines due to precipitation of fatty acids. Further detracting from possible use in jet aviation applications are the fact that fatty acids are surface active agents, and can thus act as surfactants in situations where this in decidedly unwanted. Thus current regulations limit the allowed content of fatty acid esters to less than 5 ppm in fuel pipeline systems—used in e.g. larger airports.
The application of ethers as fuel additives is not unknown in transportation fuels. Methyl-tert-butyl ether has seen extensive application as an anti-knock additive to petrol since its introduction in the seventies. Ethers have been prepared by a variety of routes, such as condensation of alcohols in the presence of catalysts such as concentrated sulphuric acid, ferric chloride and acid zeolites (Kirk-Othmer Encyclopedia of Chemical Technology, ISBN 9780471238966 vol. 10 p 567-583). A new route for the preparation of dibutyl ether has been disclosed in patent application US20100204522, utilizing an ionic liquid reaction medium. The document describes the industrial utility of dibutyl ether: “Ethers, such as the dialkyl ethers produced by the processes hereof, are useful as solvents, plasticizers and as additives in transportation fuels such as gasoline, diesel fuel and jet fuel.”
EP1218472 (U.S. Pat. No. 7,014,668) teaches the use of a complex mixture of different organic compounds, with different oxygen containing functionalities for a fuel replacement for both diesel- and jet-fuel. Specifically the document discloses that one should use a mixture containing “A total of at least four different oxygen-containing functional groups are present in at least two different oxygen-containing organic compounds.”, thus excluding systems derived from less complex compounds or mixtures.
US2009013591A1 teaches the use of more complex glycol ethers, also containing hydroxy functionalities, either as glycol or glycerol ethers, for improvement of vapour pressure and cetane value of the blended fuel of the invention. For use in jet-fuel the document teaches the use of the additives in the replacement of conventional de-icing additives, either in full or in part.
CN101423781 teaches the application of mixtures containing substituted ethers as fuel additives, specifying the use of a complex mixture containing terpene, 2-propanone, alkylene glycol ethers, dibasic methyl ester, nonyl phenol ethoxylate, and 0-15% mineral oil. The additives serve to eliminate deposit formation.
JP10316979A teaches the use of ethers, including aromatic and benzylic ethers for increasing engine power in internal combustion gasoline engines. The ethers are characterized by all being methyl ethers, and further in that the long chain of the ether is 5-6C alkyl, phenyl or benzyl; the aliphatic ethers of the document being examples of known anti-knock additives for gasoline. Further the document teaches possibility of adding further 0-30% of an aromatic compound, other than an ether, presumably in order to further enhance the octane number of the gasoline fuel of the invention.
The use of alkyl-ethers, either as pure compounds or in mixtures with variation of the chain-length of the substituted ethers allows for a simpler fuel formulation, where the ethers can be obtained directly from alcohols of biological origin. Furthermore a formulation based on ethers, or ethers in conjunction with conventional fuel components will be simpler in relation to fuel infrastructure, as only interaction of one type of functional group with said infrastructure (pumps, gaskets, fuellines etc.) will have to be investigated. Furthermore the ethers have the advantage of very low ability to solubilise water, thus reducing problems with water absorbtion. Lastly the ethers are fully miscible with conventional fuel components in all proportions.
The term “comprising” in the present application is intended to convey the idea of a collection of items that are relevant for the present invention, but it does not exclude that further items may be present and/or relevant. The term “comprising” is not intended to convey the idea of a completeness to the exclusion of other items, which would be better described by the expression “consisting of”.

SUMMARY OF THE INVENTION

In a main aspect the present invention relates to a jet aviation fuel comprising one or more aliphatic ether compound having the general formula (I):
R1-O—R2
wherein R1 and R2 individually are selected from aliphatic carbon chains.
In other aspects the invention relates to containers and aerial vehicles comprising said jet aviation fuel.

DETAILED DESCRIPTION OF THE INVENTION

The present invention discloses ethers that can be used directly in jet aviation fuel applications, or in jet aviation fuel applications when admixed with conventional jet aviation fuel, or in jet aviation fuel application when admixed with conventional hydrocarbon fuel, where the ensuing product conforms to jet aviation fuel specification. By the expression ‘conventional hydrocarbon fuel’ is intended a fuel distillate that does not conform to jet aviation fuel standards. Ethers are hydrolytically robust, non-hygroscopic and exhibit physical chemical properties that are compatible with specifications for jet aviation fuel. Not only the melting point but also the boiling point of the fuel can be controlled by choice of chain lengths or proportion of different ethers in the fuel. Furthermore the ethers can find application in mixtures with standard jet aviation fuel, or the ethers can be used to change the physical properties of fuel, not conforming to standards in the pure state, so that said fuel can fit within jet aviation specifications.
In the Table 1 is shown the physical properties of selected examples of the compounds disclosed in the invention, in comparison with two different jet-fuel specifications (conventional jet aviation fuel) and Bio-Diesel.

TABLE 1

			Boiling	Melting	Density
Name, systematic	Name	Formula	Point ° C.	point ° C.	g/cm3

Butane, 1-propoxy-	Propyl butyl ether	C₇H₁₆O	118.1		0.772 ± 0.06
Butane, 1,1′-	Diisopentyl ether	C₁₀H₂₂O	172-174		0.7777
oxybis[3-methyl-
Pentane, 1-propoxy-	Propyl pentyl ether	C₈H₁₈O	142.2 ± 3.0		0.780 ± 0.06
Pentane, 1-(1-	Isopropyl pentyl	C₈H₁₈O	129.9 ± 3.0		0.778 ± 0.06
methylethoxy)-	ether
Pentane, 1-butoxy-	Butyl pentyl ether	C₉H₂₀O	163.8 ± 8.0		0.772
Pentane, 1,1′-oxybis-	Pentyl ether	C₁₀H₂₂O	184-186	−69	0.791 ± 0.06
Hexane, 1-methoxy-	Methyl hexyl ether	C₇H₁₆O	125.9 ± 3.0		0.772 ± 0.06
Hexane, 1-ethoxy-	Ethyl hexyl ether	C₈H₁₈O	135.5 ± 2.0		0.7700
Hexane, 1-propoxy-	Propyl hexyl ether	C₉H₂₀O	165.4 ± 3.0		0.786 ± 0.06
Hexane, 1-(1-	Isopropyl hexyl	C₉H₂₀O	152.3 ± 3.0		0.784 ± 0.06
methylethoxy)-	ether
Hexane, 1-butoxy-	Butyl hexyl ether	C₁₀H₂₂O	184.4 ± 8.0		0.791 ± 0.06
Hexane, 1-(1-	(1-Methylpropyl)	C₁₀H₂₂O	175.7 ± 8.0		0.790 ± 0.06
methylpropoxy)-	hexyl ether
Hexane, 1-	Pentyl hexyl ether	C₁₁H₂₄O	204.1 ± 8.0		0.795 ± 0.06
(pentyloxy)-
Hexane, 1,1′-oxybis-	Hexyl ether	C₁₂H₂₆O	221-224		0.7936
Heptane, 1-methoxy-	Methyl heptyl	C₈H₁₈O	150.5 ± 3.0		0.780 ± 0.06
	ether
Heptane, 1-ethoxy-	Ethyl heptyl ether	C₉H₂₀O	165.5 ± 3.0	−68.3	0.786 ± 0.06
Heptane, 1-propoxy-	Propyl heptyl ether	C₁₀H₂₂O	187.1 ± 3.0		0.791 ± 0.06
Heptane, 1-butoxy-	Butyl heptyl ether	C₁₁H₂₄O	204.1 ± 8.0		0.795 ± 0.06
Heptane, 1-	Pentyl heptyl ether	C₁₂H₂₆O	222.9 ± 8.0		0.799 ± 0.06
(pentyloxy)-
Heptane, 1-(3-	Isoamyl heptyl	C₁₂H₂₆O	214.9 ± 8.0		0.798 ± 0.06
methylbutoxy)-	ether
Octane, 1-methoxy-	Methyl octyl ether	C₉H₂₀O	173.5 ± 3.0		0.786 ± 0.06
Octane, 1-ethoxy-	Ethyl octyl ether	C₁₀H₂₂O	186.7 ± 3.0		0.791 ± 0.06
Octane, 1-propoxy-	Propyl octyl ether	C₁₁H₂₄O	204.0 ± 3.0	−46.0	0.7883
Octane, 1-butoxy-	Butyl octyl ether	C₁₂H₂₆O	222.9 ± 8.0	−44.0	0.7925
Octane, 1-(2-	Isobutyl octyl ether	C₁₂H₂₆O	217.0 ± 3.0	−43.0	0.7856
methylpropoxy)-
Octane, 1-(1-	(1-Methylpropyl)	C₁₂H₂₆O	215-217	−54.0	0.7891
methylpropoxy)-	octyl ether
Octane, 1-	Pentyl octyl ether	C₁₃H₂₈O	240.9 ± 8.0		0.803 ± 0.06
(pentyloxy)-
Octane, 1-(3-	Isopentyl octyl	C₁₃H₂₈O	235 ± 3.0	−56.5	0.7938
methylbutoxy)-	ether
Nonane, 1-butoxy-	Butyl nonyl ether	C₁₃H₂₈O	240.9 ± 8.0		0.803 ± 0.06
Decane, 1-methoxy-	Methyl decyl ether	C₁₁H₂₄O	215.2 ± 3.0		0.795 ± 0.06
Decane, 1-ethoxy-	Ethyl decyl ether	C₁₂H₂₆O	225.1 ± 3.0		0.799 ± 0.06
Decane, 1-propoxy-	Propyl decyl ether,	C₁₃H₂₈O	243.9 ± 3.0		0.803 ± 0.06
Decane, 1-butoxy-	Butyl decyl ether	C₁₄H₃₀O	258.3 ± 8.0		0.806 ± 0.06
Dodecane, 1-	Propyl dodecyl	C₁₅H₃₂O	276.3 ± 3.0		0.808 ± 0.06
propoxy-	ether
Dodecane, 1-butoxy-	Butyl dodecyl	C₁₆H₃₄O	291.4 ± 8.0		0.810 ± 0.06
	ether
Jet Fuel A1		C₈-C₁₆	NA -	<−47	0.775-0.840
(specification)			mixture		g/cm3
Jet Fuel A		C₈-C₁₆	NA -	<−40	0.775-0.840
(specification)			mixture
Bio-Diesel (example)		C₁₆-C₂₂	NA -	~0	0.870-0.890
			mixture

As can be readily seen from table 1, the variation in boiling point follows the number of carbon atoms whereas, surprisingly, the melting point does not, allowing for synthesis of low-melting ethers with high boiling point. From the physical data presented it can be seen that the family of compounds disclosed can be varied to allow for specific combinations of melting point and vapour pressure (boiling point). The invention relates to these variations in physical properties, by variation of the number of carbon atoms, and the degree of branching in the aliphatic chains utilized. Indeed the necessary physical properties may be obtained by following the routes disclosed in the following, pertaining specifically to the pure ethers—composite properties can be obtained by blending of aliphatic ethers with different structures, or by admixing of aliphatic ethers or the mixture thereof with jet fuel, or by admixture of aliphatic ethers or mixtures thereof with hydrocarbon fuel not specified to jet aviation regulations, but where the fuel mixture obtained does conform to jet aviation fuel specification.
The overall boiling point of the fuel can be optimized for a specific application by controlling the overall number of carbon atoms in the aliphatic ether. Thus one can, as an example but not limited to; Butyl propyl ether with seven carbon atoms BP 118° C., Ethyl pentyl ether with 7 carbon atoms BP 119-120° C., Ethyl hexyl ether with eight carbon atoms BP 136-137° C., Isopropyl pentyl ether with eight carbon atoms BP (calc.) 130±3, Methyl octyl ether with nine carbon atoms BP 170-172° C., Dipentyl ether with ten carbon atoms BP 188° C., Methyl n-decyl ether with eleven carbon atoms BP 189° C., 1-Methyl-propyl)-octyl ether with twelve carbon atoms BP 215-217° C., Iso-pentyl octyl ether with thirteen carbon atoms BP 235° C.
The melting point of the aliphatic ethers, and thus the low-temperature properties can be modified by selecting the chain-length and branching of the aliphatic chains. Examples according to the invention being, but not limited to; Dipentyl ether with ten carbon atoms MP −69° C., Iso-pentyl octyl ether with thirteen carbon atoms MP −56.5° C., 1-Methyl-propyl)-octyl ether with twelve carbon atoms MP −54° C., Methyl octyl ether with nine carbon atoms MP −52.5° C. As can be seen the melting point surprisingly does not follow the number of carbon atoms, and indeed in the examples given Methyl octyl ether with nine carbon atoms exhibit a melting point of −52.5° C., while Iso-pentyl octyl ether with thirteen carbon atoms exhibit a melting point of −56.5° C. One can thus directly control the melting point by preparing ethers where the shortest chain of the aliphatic ether has one, two, three, four, five, or six carbon atoms, and where the chain can be either un-branched as in e.g. Dipentyl ether or branched as in Iso-pentyl octyl ether. The longer chain of the ether can, following the same rules, have four, five, six, seven, eight, nine, eleven, twelve, thirteen or fourteen carbon atoms, and said chain can be either un-branched as in e.g. Dipentyl ether or branched as in Iso-pentyl octyl ether. Furthermore the aliphatic ethers can be symmetrical such as Dipentyl ether or unsymmetrical such as Methyl octyl ether.
The aliphatic ethers may be used as an jet aviation fuel in the pure form as single compounds, or they may be used as a mixture of different ethers of the type disclosed. The aliphatic ether or mixtures of aliphatic ethers may be used as an jet aviation fuel (100%) or they may be used in mixtures such as, but not limited to, 50%, 25%, 10% or until 5% of the aliphatic ether or mixtures of aliphatic ethers, admixed with conventional jet aviation fuel.
The aliphatic ether or mixtures of aliphatic ethers may be used as a jet aviation fuel in mixtures such as, but not limited to, 50%, 25%, 10% or until 5% of the aliphatic ether or mixtures of aliphatic ethers, admixed with conventional hydrocarbon fuel where the fuel obtained conforms to jet aviation fuel standards even when the conventional hydrocarbon fuel admixed does not.
Accordingly, in one aspect the present invention relates to a jet aviation fuel comprising one or more aliphatic ether compounds having the general formula (I):
R1-O—R2
wherein R1 and R2 individually are selected from aliphatic carbon chains.
In one embodiment of the present invention the jet aviation fuel of the present invention, the total number of carbon atoms of the aliphatic ether compound is at least 6.
In another embodiment of the present invention the total number of carbon atoms of the aliphatic ether compound is at least 7.
In another embodiment of the present invention the total number of carbon atoms of the aliphatic ether compound is at least 8.
In another embodiment of the present invention the total number of carbon atoms of the aliphatic ether compound is at least 9.
In another embodiment of the present invention the total number of carbon atoms of the aliphatic ether compound is at least 10.
In another embodiment of the present invention the total number of carbon atoms of the aliphatic ether compound is at least 11.
In another embodiment of the present invention the total number of carbon atoms of the aliphatic ether compound is at least 13.
In one embodiment of the present invention the aliphatic carbon chain of formula I comprising the lowest number of carbon atoms comprises at least one carbon atom. In one embodiment the aliphatic carbon chain comprising the lowest number of carbon atoms is R1. In another embodiment the aliphatic carbon chain comprising the lowest number of carbon atoms is R2.
In one embodiment of the present invention the carbon chain of formula (I) comprising the lowest number of carbon atoms comprises at least two carbon atoms.
In one embodiment of the present invention the carbon chain of formula (I) comprising the lowest number of carbon atoms comprises at least three carbon atoms.
In one embodiment of the present invention R1 and R2 of formula (I) comprises the same number of carbon atoms.
In one embodiment of the present invention R1 and R2 are both un-branched.
In another embodiment of the present invention R1 is branched while R2 is un-branched.
In another embodiment of the present invention R2 is branched while R1 is un-branched.
In one embodiment of the present invention the one or more aliphatic ether compounds are two, three, four, five, six, seven, eight, nine, ten, eleven, twelve or more different aliphatic ether compounds, wherein the two, three, four, five, six, seven, eight, nine, ten, eleven, twelve or more different aliphatic ether compounds individually are as defined herein above.
In one embodiment of the present invention the one or more aliphatic ether compounds are 13 or more different aliphatic ether compounds, such as 14 or more different aliphatic ether compounds, for example 15 or more different aliphatic ether compounds, such as 16 or more different aliphatic ether compounds, for example 17 or more different aliphatic ether compounds, such as 18 or more different aliphatic ether compounds, for example 19 or more different aliphatic ether compounds, such as at least 20 or more different aliphatic ether compounds, and wherein said different aliphatic ether compounds individually are as defined herein above.
In one embodiment of the present invention the one or more aliphatic ether compound is selected from the group consisting of Propyl butyl ether, Diisopentyl ether, Propyl pentyl ether, Isopropyl pentyl ether, Butyl pentyl ether, Pentyl ether, Methyl hexyl ether, Ethyl hexyl ether, Propyl hexyl ether, Isopropyl hexyl ether, Butyl hexyl ether, (1-Methylpropyl) hexyl ether, Pentyl hexyl ether, Hexyl ether, Methyl heptyl ether, Ethyl heptyl ether, Propyl heptyl ether, Butyl heptyl ether, Pentyl heptyl ether, Isoamyl heptyl ether, Methyl octyl ether, Ethyl octyl ether, Propyl octyl ether, Butyl octyl ether, Isobutyl octyl ether, (1-Methylpropyl) octyl ether, Pentyl octyl ether, Isopentyl octyl ether, Butyl nonyl ether, Methyl decyl ether, Ethyl decyl ether, Propyl decyl ether, Butyl decyl ether, Propyl dodecyl ether and Butyl dodecyl ether.
In one embodiment of the present invention the one or more aliphatic ether compound is selected from the group consisting of aliphatic ether compounds having a boiling point between 115° C. and 300° C., preferably between 200° C. and 300° C.
In one embodiment of the present invention the one or more aliphatic ether compound is selected from the group consisting of aliphatic ether compounds having a density of between 0.71 and 0.82 g/cm³.
In one embodiment of the present invention the jet aviation fuel as defined herein above contains a 50% admixture of conventional jet aviation fuel.
In another embodiment the present invention the jet aviation fuel consists entirely of one or more aliphatic ether compounds wherein said different aliphatic ether compounds are as defined herein above.
In one embodiment of the present invention the jet aviation fuel as defined herein above contains at least a 55% admixture of conventional jet aviation fuel, such as at least a 60% admixture of conventional jet aviation fuel, for example at least a 65% admixture of conventional jet aviation fuel.
In one embodiment the jet aviation fuel of the present invention contains a 75% admixture of conventional jet aviation fuel, such as at least a 80% admixture of conventional jet aviation fuel, for example at least a 85% admixture of conventional jet aviation fuel, such as at least a 87% admixture of conventional jet aviation fuel,
In one embodiment of the present invention the jet aviation fuel as defined herein above contains a 90% admixture of conventional jet aviation fuel, such as at least a 91% admixture of conventional jet aviation fuel, for example at least a 92% admixture of conventional jet aviation fuel, such as at least a 93% admixture of conventional jet aviation fuel, for example at least a 94% admixture of conventional jet aviation fuel, such as at least a 95% admixture of conventional jet aviation fuel, for example at least a 96% admixture of conventional jet aviation fuel, such as at least a 97% admixture of conventional jet aviation fuel, for example at least a 98% admixture of conventional jet aviation fuel, such as at least a 99% admixture of conventional jet aviation fuel.
In one embodiment of the present invention the jet aviation fuel as defined herein above contains an at least 50% admixture of a conventional hydrocarbon fuel, and wherein the fuel mixture thus obtained conforms to jet aviation fuel standards.
In one embodiment of the present invention the jet aviation fuel as defined herein above contains an at least 55% admixture of a conventional hydrocarbon fuel, and wherein the fuel mixture thus obtained conforms to jet aviation fuel standards.
In one embodiment of the present invention the jet aviation fuel as defined herein above contains an at least 60% admixture of a conventional hydrocarbon fuel, and wherein the fuel mixture thus obtained conforms to jet aviation fuel standards.
In one embodiment of the present invention the jet aviation fuel as defined herein above contains an at least 65% admixture of a conventional hydrocarbon fuel, and wherein the fuel mixture thus obtained conforms to jet aviation fuel standards.
In one embodiment of the present invention the jet aviation fuel as defined herein above contains an at least 70% admixture of a conventional hydrocarbon fuel, and wherein the fuel mixture thus obtained conforms to jet aviation fuel standards.
In one embodiment of the present invention the jet aviation fuel as defined herein above an at least 75% admixture of a conventional hydrocarbon fuel, and wherein the fuel mixture thus obtained conforms to jet aviation fuel standards.
In one embodiment of the present invention the jet aviation fuel as defined herein above contains an at least 80% admixture of a conventional hydrocarbon fuel, and wherein the fuel mixture thus obtained conforms to jet aviation fuel standards.
In one embodiment of the present invention the jet aviation fuel as defined herein above contains an at least 85% admixture of a conventional hydrocarbon fuel, and wherein the fuel mixture thus obtained conforms to jet aviation fuel standards.
In one embodiment of the present invention the jet aviation fuel as defined herein above contains an at least 90% admixture of a conventional hydrocarbon fuel, and wherein the fuel mixture thus obtained conforms to jet aviation fuel standards.
In one embodiment of the present invention the jet aviation fuel as defined herein above contains an at least 95% admixture of a conventional hydrocarbon fuel, and wherein the fuel mixture thus obtained conforms to jet aviation fuel standards.
In one embodiment of the present invention the jet aviation fuel as defined herein above is not for use for increasing the engine power in internal combustion gasoline engines.
In one embodiment of the present invention defined herein above, R1 is not methyl, when R2 is C5 or C6 alkyl, phenyl or benzyl.
In one embodiment of the present invention defined herein above, R2 is not methyl, when R1 is C5 or C6 alkyl, phenyl or benzyl.
Similarly, in one aspect the present invention relates to the use of the jet aviation fuel as defined herein above in a jet engine.
In one embodiment, said jet engine is selected from the group consisting of turbojet engine, turboprop jet engine, turbofan jet engine, and turboshaft jet engine.
In one aspect the present invention relates to a container comprising the jet aviation fuel as defined herein above.
In another aspect the present invention relates to an aerial vehicle comprising the container defined herein above.
In yet another aspect the present invention concerns an aerial vehicle comprising the jet aviation fuel as defined herein above.

EXAMPLES

In the following is given examples of jet aviation fuel compositions of the current invention. It is to be understood that the examples in the following are by no means exhaustive or limiting for the invention, and are only provided to illustrate some embodiments of the invention.
Jet aviation fuel compositions vary widely according to geographical variation and intended application. As an example the requirements for fuel used for long distance flying such as e.g. transatlantic crossings poses stricter limits as to low temperature performance as compared to less demanding application. Below in Table 2 are shown pertinent parameters for some of the commonly used jet-fuel specifications:

TABLE 2

Fuel specification	Jet A	Jet A-1	TS-1	Jet B

Initial boiling point ° C.	—	Report	150	Report
10% recovery max ° C.	205	205	165	Report
50% recovery max ° C.	Report	Report	195	Min 125-max 190
90% recovery max ° C.	Report	Report	230	Report
End point ° C.	300	300	250	Report
Freezing point, max ° C.	−40	−47	−50	−51

It should be emphasized that the current standards are aimed at qualifying fuels from hydrocarbon stock, and that work is currently in progress within the auspices of national bodies of standardization such as ASTM to develop standards specifically targeting bio-fuel. (Kirk-Othmer Encyclopedia of Chemical Technology, ISBN 9780471238966, “Jet-Fuels”, p1-31 and Chevron, Aviation Fuels Technical Review (FTR-3), 2006)
The examples below serving to illustrate how distillation and melting profile of commercial offerings can be accommodated by the fuel formulations of the invention, either as ether only fuel or admixed with fossil fuel.

Example 1


	Propyl butyl ether	15%
	Ethyl heptyl ether	10%
	Butyl decyl ether	25%
	Methyl decyl ether	25%

Example 2


	Fuel according to specification Jet B	75%
	Formulation example 1	25%

Example 3


	Fuel according to specification Jet B	25%
	Formulation example 1	75%

Example 4


	Methyl heptyl ether	10%
	Methyl octyl ether	40%
	(1-Methylpropyl) octyl ether	40%
	Isopentyl octyl ether	10%

Example 5


	Fuel according to specification TS-1	75%
	Formulation example 4	25%

Example 6


	Fuel according to specification TS-1	25%
	Formulation example 4	75%

Example 7


	Propyl hexyl ether	10%
	Hexyl ether	90%

Example 8


	Fuel according to specification Jet A-1	25%
	Formulation example 7	75%

Example 9


	Fuel according to specification Jet A-1	25%
	Formulation example 7	75%

Example 10


	Propyl hexyl ether	10%
	Hexyl ether	40%
	Ethyl decyl ether	50%

Example 11


	Fuel according to specification Jet A	25%
	Formulation example 10	75%

Example 12


	Fuel according to specification Jet A	25%
	Formulation example 10	15%

Thus in summary a jet aviation fuel based on aliphatic ethers is disclosed where the fuel consist of one or more compounds according to the invention, a mixture of compounds according to the invention, a mixture of the pure or mixed aliphatic ethers admixed with conventional jet aviation fuel, or a mixture of said ethers with conventional hydrocarbon fuel, giving a product conforming to a jet aviation fuel standard.
The foregoing description of the specific embodiments will so fully reveal the general nature of the present invention that others skilled in the art can, by applying current knowledge, readily modify or adapt for various applications such specific embodiments without undue experimentation and without departing from the generic concept, and therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. The means, materials, and steps for carrying out various disclosed functions may take a variety of forms without departing from the invention.

Claims

1-55. (canceled)

56. A jet aviation fuel comprising an aliphatic ether compound of formula (I):

R1-O—R2

wherein R1 and R2 individually are aliphatic carbon chains.

57. The jet aviation fuel of claim 56, the aliphatic ether compound of formula (I) having a total number of carbon atoms in the range of 6 to 16.

58. The jet aviation fuel of claim 56, R1 having 1 to 10 carbon atoms.

59. The jet aviation fuel of claim 58, R1 having 1 to 3 carbon atoms and R2 having 4 to 10 carbon atoms.

60. The jet aviation fuel of claim 56, R2 having 1 to 10 carbon atoms.

61. The jet aviation fuel of claim 60, R2 having 1 to 3 carbon atoms and R1 having 4 to 10 carbon atoms.

62. The jet aviation fuel of claims 56, R1 and R2 individually being un-branched aliphatic carbon chains.

63. The jet aviation fuel of claim 56, the aliphatic ether compound of formula (I) being selected from the group consisting of propyl butyl ether, diisopentyl ether, propyl pentyl ether, isopropyl pentyl ether, butyl pentyl ether, pentyl ether, methyl hexyl ether, ethyl hexyl ether, propyl hexyl ether, isopropyl hexyl ether, butyl hexyl ether, (1-methylpropyl) hexyl ether, pentyl hexyl ether, hexyl ether, methyl heptyl ether, ethyl heptyl ether, propyl heptyl ether, butyl heptyl ether, pentyl heptyl ether, isoamyl heptyl ether, methyl octyl ether, ethyl octyl ether, propyl octyl ether, butyl octyl ether, isobutyl octyl ether, (1-methylpropyl) octyl ether, pentyl octyl ether, isopentyl octyl ether, butyl nonyl ether, methyl decyl ether, ethyl decyl ether, propyl decyl ether, butyl decyl ether, propyl dodecyl ether and butyl dodecyl ether.

64. The jet aviation fuel of claim 56, the aliphatic ether compound of formula (I) having a boiling point between 115° C. and 300° C.

65. The jet aviation fuel of claim 56, the aliphatic ether compound of formula (I) having a density of between 0.71 and 0.82 g/cm³.

66. The jet aviation fuel of claim 56, further comprising at least 25% of a conventional jet aviation fuel.

67. The jet aviation fuel of claim 66, the conventional jet aviation fuel being at least 75% to 99% of the jet aviation fuel.

68. The jet aviation fuel of claim 66, the conventional jet aviation fuel being selected from the group consisting of Jet A, Jet A-1, TS-1, Jet B or combinations thereof.

69. The jet aviation fuel of claim 66, the conventional jet aviation fuel being a hydrocarbon fuel having a mixture of components each having a total number of carbon atoms in the range of 8 to 16.

70. The jet aviation fuel of claim 66, the jet aviation fuel having more than one aliphatic ether compound of formula (I).

71. The jet aviation fuel of claim 70, the more than one aliphatic ether compound of formula (I) being selected from the group consisting of propyl butyl ether, diisopentyl ether, propyl pentyl ether, isopropyl pentyl ether, butyl pentyl ether, pentyl ether, methyl hexyl ether, ethyl hexyl ether, propyl hexyl ether, isopropyl hexyl ether, butyl hexyl ether, (1-methylpropyl) hexyl ether, pentyl hexyl ether, hexyl ether, methyl heptyl ether, ethyl heptyl ether, propyl heptyl ether, butyl heptyl ether, pentyl heptyl ether, isoamyl heptyl ether, methyl octyl ether, ethyl octyl ether, propyl octyl ether, butyl octyl ether, isobutyl octyl ether, (1-methylpropyl) octyl ether, pentyl octyl ether, isopentyl octyl ether, butyl nonyl ether, methyl decyl ether, ethyl decyl ether, propyl decyl ether, butyl decyl ether, propyl dodecyl ether and butyl dodecyl ether.

72. The jet aviation fuel of claim 56, the jet aviation fuel being not for use in internal combustion gasoline engines.

73. The jet aviation fuel of claim 56, the jet aviation fuel being for use in a jet engine.

74. A jet aviation fuel comprising:

i. at least 25% of a hydrocarbon jet fuel admixture, wherein the hydrocarbon jet fuel admixture being not for use in an internal combustion gasoline engine, and

ii. at least 25% of two or more aliphatic ether compounds.

75. The jet aviation fuel of claim 74, the two or more aliphatic ether compounds being selected from the group consisting of propyl butyl ether, diisopentyl ether, propyl pentyl ether, isopropyl pentyl ether, butyl pentyl ether, pentyl ether, methyl hexyl ether, ethyl hexyl ether, propyl hexyl ether, isopropyl hexyl ether, butyl hexyl ether, (1-methylpropyl) hexyl ether, pentyl hexyl ether, hexyl ether, methyl heptyl ether, ethyl heptyl ether, propyl heptyl ether, butyl heptyl ether, pentyl heptyl ether, isoamyl heptyl ether, methyl octyl ether, ethyl octyl ether, propyl octyl ether, butyl octyl ether, isobutyl octyl ether, (1-methylpropyl) octyl ether, pentyl octyl ether, isopentyl octyl ether, butyl nonyl ether, methyl decyl ether, ethyl decyl ether, propyl decyl ether, butyl decyl ether, propyl dodecyl ether and butyl dodecyl ether.