HIGH-POWER AND ECO-FRIENDLY FUEL COMPOSITION

Abstract

The present invention relates to a fuel composition comprising:from 35% to 75% by weight of cyclopentane,from 10% to 25% by weight of one or more aromatic hydrocarbon(s), andup to 55% by weight of one or more branched alkane(s) chosen from 2-methylbutane and trimethylpentanes, with a weight ratio of the cyclopentane content to the aromatic hydrocarbon content greater than or equal to 2. The invention also relates to the use of such a composition for supplying a spark ignition engine, in particular for increasing the engine power and/or for reducing the specific fuel consumption of the engine and/or for increasing the octane number (RON).

Claims

1. A fuel composition comprising from 35% to 75% by weight of cyclopentane, from 10% to 25% by weight of one or more aromatic hydrocarbons, and up to 55% by weight of one or more branched alkanes chosen from 2-methylbutane and trimethylpentanes, with a weight ratio of the cyclopentane amount to the aromatic hydrocarbon amount greater than or equal to 2.

2. The fuel composition according to claim 1, characterised in that the cyclopentane amount ranges from 36 to 62% by weight relative to the total weight of the composition.

3. The fuel composition according to claim 1, characterised in that the one or more aromatic hydrocarbons are chosen from among C.sub.7 to C.sub.10 hydrocarbons containing a benzene ring.

4. The fuel composition according to claim 3, characterised in that the one or more aromatic hydrocarbons are chosen from those including, on the benzene ring: a single substituent; or two substituents in the meta or para position; or three substituents in the meta position.

5. The fuel composition according to claim 4, characterised in that the one or more aromatic hydrocarbons are chosen from among toluene, ethylbenzene, xylenes, 1-ethyl-3-methylbenzene, mesitylene (1,3,5-trimethylbenzene), 1-ethyl-3,5-dimethylbenzene, and mixtures of these compounds.

6. The fuel composition according to claim 1, characterised in that the aromatic hydrocarbon amount ranges from 13 to 24% by weight, relative to the total weight of the composition.

7. The fuel composition according to claim 1, characterised in that it has a weight ratio of its cyclopentane amount to its aromatic hydrocarbon amount that lies in the range of 2 to 7.

8. The fuel composition according to claim 1, characterised in that the one or more branched alkanes are chosen from among trimethylpentanes, 2,3,3-trimethylpentane, 2,3,4-trimethylpentane and mixtures thereof.

9. The fuel composition according to claim 1, characterised in that the branched alkane contained therein is 2,2,4-trimethylpentane (isooctane).

10. The fuel composition according to claim 1, characterised in that it contains said one or more branched alkanes in an amount of up to 50% by weight relative to the total weight of the composition.

11. Use of a composition as defined in claim 1 to increase the RON of a gasoline fuel composition.

12. The use of the fuel composition as defined in claim 1 to supply a spark ignition direct injection engine or an indirect injection engine.

13. The use according to claim 12 to increase the power of the engine.

14. The use according to claim 12 to reduce the specific fuel consumption of the engine.

15. The use according to claim 12, wherein the engine is a high-efficiency and high-power spark ignition engine, preferably an engine of a motor racing vehicle.

16. The fuel of claim 5, where the xylenes comprise 1,3-dimethylbenzene or meta-xylene and 1,4-dimethylbenzene or para-xylene.

17. The fuel of claim 5, characterised in that the one or more aromatic hydrocarbons are chosen from among toluene, xylenes and mixtures of these compounds.

18. The fuel composition of claim 7, where the weight ratio of its cyclopentane amount to its aromatic hydrocarbon amount lies in the range of 2 to 6.5.

19. The fuel composition of claim 7, where the weight ratio of its cyclopentane amount to its aromatic hydrocarbon amount lies in the range of 2.5 to 4.

20. The fuel composition according to claim 10, characterised in that it contains said one or more branched alkanes in an amount in the range of 15 to 50% by weight relative to the total weight of the composition.

Description

DETAILED DESCRIPTION

[0043] The Fuel Composition

[0044] As stated hereinabove, the composition according to the invention contains cyclopentane, in an amount ranging from 35% to 75% by weight, relative to the total weight of the composition.

[0045] Preferably, the amount of cyclopentane ranges from 36 to 62% by weight relative to the total weight of the composition.

[0046] The composition according to the invention further contains one or more aromatic hydrocarbons, in an amount ranging from 10 to 25% by weight, relative to the total weight of the composition.

[0047] Preferably, the aromatic hydrocarbon amount ranges from 13 to 24% by weight, relative to the total weight of the composition.

[0048] The aromatic hydrocarbons are advantageously monocyclic. They are preferably chosen from among C7 to C10 hydrocarbons containing a benzene ring.

[0049] According to one preferred embodiment, the one or more aromatic hydrocarbons are chosen from those including, on the benzene ring: a single substituent; or two substituents in the meta or para position; or three substituents in the meta position.

[0050] The one or more aromatic hydrocarbons are more preferably chosen from among toluene, ethylbenzene, xylenes (and in particular 1,2-dimethylbenzene or ortho-xylene, 1,3-dimethylbenzene or meta-xylene and 1,4-dimethylbenzene or para-xylene, preferably meta-xylene and para-xylene), 1-ethyl-3-methylbenzene, mesitylene (1,3,5-trimethylbenzene), 1-ethyl-3,5-dimethylbenzene, and mixtures of these compounds.

[0051] Toluene, xylenes and mixtures of these compounds are particularly preferred.

[0052] Moreover, the composition according to the invention has a weight ratio of its cyclopentane amount to its aromatic hydrocarbon amount that is greater than or equal to 2. Preferably, this weight ratio lies in the range 2 to 7, more preferably in the range 2 to 6.5, and even more preferably in the range 2.5 to 4.

[0053] According to one particularly preferred embodiment, this weight ratio lies in the range 2.8 to 3.2 and more preferably in the range 3 to 3.2.

[0054] Finally, the composition according to the invention contains one or more branched alkanes chosen from among 2-methylbutane and trimethylpentanes, the amount whereof can reach up to 55% by weight, preferably up to 50% by weight, relative to the total weight of the composition. Preferably, this amount lies in the range 15 to 50% by weight, relative to the total weight of the composition.

[0055] Preferably, the one or more branched alkanes are chosen from among trimethylpentanes, and more preferably from among 2,2,4-trimethylpentane (or isooctane), 2,3,3-trimethylpentane, 2,3,4-trimethylpentane and mixtures thereof.

[0056] 2,2,4-trimethylpentane (isooctane) is particularly preferred.

[0057] The composition as described hereinabove has a research octane number (RON number) greater than or equal to 95, preferably greater than or equal to 100, and more preferably greater than or equal to 101, the RON being measured according to the standard ASTM D 2699-86.

[0058] The aforementioned values relate to the intrinsic octane number of the composition, that is to say without the addition of additional compounds, in particular such as octane boosting additives, for example those described above.

[0059] In addition to the base compounds described hereinabove, the fuel composition according to the invention can further comprise one or more additives, chosen from among those conventionally used in gasoline fuels.

[0060] In particular, the composition according to the invention can comprise at least one detergent additive ensuring the cleanliness of the intake circuit. Such an additive can for example be chosen from within the group consisting of succinimides, polyetheramines and quaternary ammonium salts, for example those described in the patent documents U.S. Pat. No. 4,171,959 and WO2006135881.

[0061] The composition can also comprise at least one lubricity additive or anti-wear agent, in particular (but in a non-limiting manner) chosen from within the group consisting of fatty acids and the ester or amide derivatives thereof, in particular glycerol monooleate, and derivatives of mono- and polycyclic carboxylic acids. Examples of such additives are given in the following patent documents: EP680506, EP860494, WO98/04656, EP915944, FR2772783 and FR2772784.

[0062] Other additives can also be incorporated into the fuel composition according to the invention, such as additives protecting against valve seat recession and anti-oxidant additives.

[0063] For use in a racing vehicle, in order to ensure maximum safety when refuelling, the electrical conductivity of the fuel is moreover preferably greater than 200 pS/m. For this purpose, at least one additive can be added to lower the electrical conductivity.

[0064] The additives described hereinabove can be added in amounts ranging, for each thereof, from 10 to 1,000 ppm by weight, preferably from 100 to 500 ppm by weight, to the fuel composition.

[0065] The fuel compositions according to the invention have a lead concentration that is generally less than or equal to 0.5 g/L (present for example in the form of tetraethyl lead), and are preferably unleaded, i.e. they do not contain lead or any lead-containing compound.

[0066] The composition according to the invention can be prepared by simply mixing the constituents thereof.

[0067] One non-limiting example of a preparation method comprises the following steps of:

[0068] preparing a mixture A containing 75% by weight of cyclopentane and 25% by weight of one or more aromatic hydrocarbons as described hereinabove; then

[0069] adding the one or more branched alkanes to the mixture A, to a maximum concentration of 55% by weight of the final mixture.

[0070] This example provides a composition according to the invention that has a cyclopentane/aromatic hydrocarbon weight ratio of 3. It goes without saying that a person skilled in the art will know how to adapt this method to the preparation of other compositions in the formulation field of the invention.

[0071] Uses

[0072] The invention further relates to the use of the composition as described hereinabove to supply a spark ignition engine. The engine can be of the direct injection type or of the indirect injection type.

[0073] According to a first embodiment, the composition according to the invention is used to increase the power of the engine.

[0074] In this embodiment, the fuel composition can be advantageously used to supply a high-efficiency and high-power spark ignition engine, preferably an engine of a motor racing vehicle. It can in particular be a naturally-aspirated or turbocharged engine used in a racing vehicle (race track or rally vehicles).

[0075] According to a second embodiment, the composition according to the invention is used to reduce the specific fuel consumption of the engine.

[0076] In this embodiment, the use according to the invention is of the fuel economy type, i.e. the specific fuel consumption thereof is reduced.

[0077] This use also allows the amount of CO2 emitted into the atmosphere to be reduced.

[0078] The invention further relates to the use of the composition as described hereinabove to increase the RON (also known as the research octane number) of a gasoline fuel composition.

[0079] The examples hereafter are solely intended to illustrate the invention, and must not be interpreted as limiting the scope thereof.

EXAMPLES

Example 1: Preparing a Composition According to the Invention

[0080] The composition C, according to the invention, was prepared from the following starting compounds A and B: [0081] A: a mixture of 75.5% by weight of cyclopentane with 24.5% by weight of aromatic hydrocarbons formed by a mixture of toluene and xylenes, having the following detailed composition:

TABLE-US-00001 Composition of the mixture A % by weight cyclopentane 75.5 toluene 6.8 paraxylene 6.3 orthoxylene 2.8 metaxylene 6.6 ethylbenzene 2 [0082] B: isooctane (2,2,4-trimethylpentane).

[0083] The composition C was obtained by simply mixing 50% by weight of A with 50% by weight of B. The final composition thereof is as follows: [0084] 37.75% by weight of cyclopentane, [0085] 12.25% by weight of aromatic hydrocarbons, [0086] 50% by weight of isooctane, [0087] Cyclopentane amount/aromatic hydrocarbon amount weight ratio=3.1.

Example 2: Properties of the Fuel Composition C

[0088] The following parameters were measured for the composition C of the invention, as well as for each of the starting compounds A and B:

[0089] Octane number RON, according to the protocol described in the standard ASTM D 2699-86: [0090] RON(A)=102.7 [0091] RON(B)=100 [0092] RON(C)=104.9

[0093] It is clear that:

RON(C)>RON(A),

RON(C)>RON(B), and

RON(C)>(RON(A)+RON(B))/2

[0094] Specific power P, and specific fuel consumption SFC (the latter corresponding to the mass of fuel needed to produce 1 kW.Math.h of useful energy output):

[0095] The measurements were carried out under the same conditions for the three compositions, at constant fuel flow rate, on the same single-cylinder spark ignition engine, with a cubic capacity 350 cm3 and provided with direct fuel injection.

[0096] Results obtained, in terms of specific power: [0097] P(A)=13.6 kW [0098] P(B)=12.9 kW [0099] P(C)=13.9 kW

[0100] It is clear that:

P(C)>P(A),

P(C)>P(B), and

P(C)>(P(A)+P(B))/2

[0101] Results obtained, in terms of specific fuel consumption: [0102] SFC(A)=232.5 g/kW.Math.h [0103] SFC(B)=247.9 g/kW.Math.h [0104] SFC(C)=227.6 g/kW.Math.h

[0105] It is clear that:

SFC(C)<SFC(A),

SFC(C)<SFC(B), and

SFC(C)<(SFC(A)+SFC(B))/2

[0106] These results show that the composition C according to the invention procures synergistic results as regards both the octane number RON and the specific power and specific fuel consumption, relative to each of the starting components A and B.

[0107] These improved performance levels are the result of the particular combination of the compounds claimed in the specific proportions defined in the present application, as well as of the choice of the higher weight ratio of the cyclopentane amount to the aromatic hydrocarbon amount.