Fuel composition rich in aromatic compounds, paraffins and ethers and their use in motor vehicles

Description

[0001] The present invention relates to a fuel composition intended for vehicles comprising a spark-ignition engine (or gasoline engine), and which has advantageous properties.

[0002] The invention also relates to the use of such a composition for supplying a spark-ignition engine, both in a conventional vehicle, in particular an automobile, and in a competition vehicle.

[0003] Gasoline-type fuels used in spark-ignition engines, particularly those in motor vehicles, must have sufficiently high octane ratings to avoid knocking.

[0004] As is well known in itself, the octane number measures the resistance to self-ignition of a fuel used in a spark-ignition engine.

[0005] Typically, gasoline fuels sold in Europe, compliant with the EN 228 standard, have a motor octane number (MON) greater than 85 and a research octane number (RON) of at least 95. These fuels are suitable for the vast majority of automobile engines.

[0006] In order to increase their efficiency, modern spark-ignition engines tend to operate with increasingly higher volumetric compression ratios, i.e. with a high compression ratio applied to the fuel / air mixture in the engine before it is ignited.

[0007] However, increasing the volumetric compression ratio in an engine increases the risk of abnormal combustion of the knocking type, generated by local self-ignition of the fuel mixture upstream of the flame front. This phenomenon creates a characteristic noise, and is likely to damage the engine.

[0008] For very high power engines, such as those used in motor racing vehicles, a high volumetric compression ratio is particularly sought.

[0009] For this type of engine, it is therefore essential to use fuels with high resistance to knocking and pre-ignition, which means fuels with the highest possible "research" octane numbers (RON). If the octane numbers are insufficient, the phenomenon of knocking or self-ignition of the fuel is likely to appear, which can significantly reduce engine performance and even cause serious damage to it.

[0010] Furthermore, for all vehicles, and particularly those intended for consumer applications, there is a growing desire to use fuels formulated from renewable sources, particularly so-called "bio-sourced" bases, in order to address environmental concerns and limit the use of fossil resources. Current environmental concerns are therefore pushing consumers to seek more environmentally friendly fuels.

[0011] However, the use of fuel compositions from bio-sourced bases must not be to the detriment of fuel performance, and in particular the octane rating and engine power, which must be maintained or even increased.

[0012] The most commonly used gasoline fuels with a high biocompound content are fuels containing bioethanol, such as E85 fuels. However, the use of these fuels represents a small share of the current automotive market.

[0013] It is known to mix bioethanol with SP95 gasoline fuel. The ethanol content is then limited to a maximum of 10% by volume in order to comply with the specifications of the EN 228 standard, particularly with regard to the incorporation of oxygenated compounds.

[0014] There is therefore a need to develop new fuel compositions intended to power spark-ignition engines that meet the requirements of modern vehicles, whether they are intended for consumer applications (light vehicles, heavy goods vehicles, "off-road" i.e. non-road vehicles, etc.) or for competition.

[0015] Thus, there is a need for fuels for spark-ignition internal combustion engines that have a high octane rating, and in particular a high RON, and which make it possible to maximize the engine power of motor vehicles operating with a high volumetric compression ratio, in particular competition vehicles.

[0016] An objective of the present invention is therefore to improve the performance of gasoline fuel compositions, in particular but not limited to fuel compositions intended for competition vehicles. The objective is to increase the energy content of the fuel, which will lead to an increase in the power of the spark-ignition engine, whether naturally aspirated, turbocharged, hybrid or not, during combustion of the gasoline fuel composition in the engine.

[0017] There is also a growing need to be able to formulate such compositions from bases and / or compounds of renewable origin, also called bio-sourced compounds.

[0018] As is well known in the prior art, octane-enhancing additives (or octane boosters) are typically added to gasoline-type fuel compositions. Organometallic compounds, particularly including iron, lead, or manganese, are well-known octane-enhancing agents.

[0019] Thus, tetraethyl lead (TEL) has been widely used as a very effective octane improver. However, in most parts of the world, TEL and other organometallic compounds can now only be used in fuels in very small quantities, if at all, because they can be toxic, damage the engine, and are harmful to the environment.

[0020] Non-metal-based octane enhancers include oxygenates (e.g., ethers and alcohols) and aromatic amines. However, these amines suffer from various disadvantages. For example, N-methylaniline (NMA), an aromatic amine, must be used at a relatively high treatment rate (1.5 to 2% by mass of additive / mass of fuel base) to have a significant effect on fuel octane. NMA can also be toxic.

[0021] For example, US-A-4812146 describes unleaded gasoline fuel compositions for racing engines which comprise at least four components selected from butane, isopentane, toluene, MTBE (methyl tert-butyl ether) and an alkylate.

[0022] Document WO2010 / 014501 describes unleaded gasoline fuel compositions comprising at least 45% by volume of branched paraffins, at most 34% by volume of one or more mono- and di-alkylated benzenes, from 5 to 6% by volume of at least one linear paraffin having from 3 to 5 carbon atoms (denoted C3-C5), one or more alkanols having from 2 to 4 carbon atoms (denoted C2-C4), in an amount sufficient to increase the AKI (Anti Knock Index) i.e. (RON+MON) / 2 by at least 93. These compositions are presented as having high torque and maximum power.

[0023] FR3080382 A1 discloses a fuel composition and the use of said composition in a motor racing vehicle engine

[0024] Thus, we are looking for fuel compositions with good intrinsic properties, that is to say without it necessarily being necessary to add additives improving the octane number such as those described above.

[0025] Continuing its research into the development of fuel formulations for gasoline engines, the Applicant has now discovered a composition which makes it possible to meet the above objectives.

[0026] The present invention therefore relates to a fuel composition comprising: (i) from 50 to 79% by mass of a mixture of hydrocarbons comprising: a) from 35 to 55% by mass of aromatic compounds; b) from 30 to 50% by mass of non-cyclic paraffins containing at least 5 carbon atoms; and c) from 5 to 15% by mass of naphthenes; (ii) from 20 to 40% by mass of one or more ethers; and (iii) from 1 to 10% by mass of butane.

[0027] These compositions are intended to power spark-ignition engines (or gasoline engines).

[0028] The fuel compositions according to the invention have high RON (Research Octane Number) octane ratings.

[0029] In uses in which the fuel flow rate is capped, particularly in the case of competition vehicles, the use of the composition according to the invention makes it possible to achieve higher engine power levels, at constant fuel flow rate.

[0030] In particular, the formulation of a composition with the compounds and in the specific proportions defined above has been shown to achieve synergistic performance in terms of octane number RON, lower calorific value PCI and engine power.

[0031] These properties are particularly sought after for use in competition vehicles.

[0032] The composition according to the invention also has significant advantages for uses other than in competition vehicles, such as for example so-called general public uses, in particular for light vehicles (or LVs). It can, where appropriate, meet the specifications of standard EN 228.

[0033] It also has a low level of emissions of undesirable compounds, such as nitrogen oxides (NOx).

[0034] The composition according to the invention may advantageously be, in whole or in part, prepared from bases and / or compounds of renewable origin, for example of plant origin. In particular, the composition according to the invention may contain at least 50% by mass of one or more bio-sourced bases, preferably at least 60% by mass, more preferably at least 65% by mass and better still at least 70% by mass of one or more bio-sourced bases.

[0035] It therefore makes it possible to very substantially reduce greenhouse gas emissions, determined in accordance with EU Directive 2018 / 2001 of the European Parliament and of the Council of 11 December 2018 on the promotion of the use of energy produced from renewable sources.

[0036] The reduction in greenhouse gas emissions obtained by means of the fuel composition of the invention is at least 50%, compared to the reference fossil fuel defined in this Directive.

[0037] The invention also relates to the use of the composition according to the invention for supplying a spark-ignition engine.

[0038] According to a particular embodiment, the composition according to the invention is used as fuel to power a high-efficiency, high-power spark-ignition engine, preferably a motor racing vehicle engine.

[0039] Other objects, characteristics, aspects and advantages of the invention will appear even more clearly on reading the description and examples which follow.

[0040] In what follows, and unless otherwise indicated, the limits of a domain of values ​​are included in this domain, notably in the expressions: "between... and...", "in the range from... to...", and "ranging from... to...".

[0041] Furthermore, the expressions “at least one” and “at least” used in this description are respectively equivalent to the expressions “one or more” and “greater than or equal”.

[0042] Finally, in a manner known per se, a CN compound is a compound containing N carbon atoms in its chemical structure. Fuel composition

[0043] The composition according to the invention contains a mixture (i) of hydrocarbons containing: (a) from 35 to 55% by mass of aromatic compounds; (b) from 30 to 50% by mass of non-cyclic paraffins containing at least 5 carbon atoms; and (c) from 5 to 15% by mass of naphthenes.

[0044] These contents are expressed in mass, relative to the mass of the hydrocarbon mixture (i).

[0045] Such a mixture of hydrocarbons represents from 50 to 79% by mass, relative to the total mass of the fuel composition, preferably from 55 to 75% by mass, and more preferably from 60 to 70% by mass, relative to the total mass of the fuel composition.

[0046] The aromatic compound(s) (i)a) are preferably chosen from alkylbenzenes comprising from 7 to 12 carbon atoms. By alkylbenzenes is meant, in a manner known per se, benzene derivatives in which one or more hydrogen atoms are replaced by one or more alkyl groups.

[0047] The aromatic compound(s) may in particular be chosen from toluene (methylbenzene), ethylbenzene, xylenes (and in particular 1,2-dimethylbenzene or ortho-xylene, 1,3-dimethylbenzene or meta-xylene and 1,4-dimethylbenzene or para-xylene), 1-ethyl-3-methylbenzene, mesitylene (1,3,5-trimethylbenzene), 1-ethyl-3,5-dimethylbenzene, and mixtures of these compounds.

[0048] Particularly preferred are mixtures of aromatic compounds, and more particularly mixtures of alkyl-benzenes comprising from 7 to 10 carbon atoms such as methylbenzene, ethylbenzene, xylenes (and in particular 1,2-dimethylbenzene or ortho-xylene, 1,3-dimethylbenzene or meta-xylene and 1,4-dimethylbenzene or para-xylene), 1-ethyl-3-methylbenzene, mesitylene (1,3,5-trimethylbenzene), and 1-ethyl-3,5-dimethylbenzene.

[0049] Preferably, the content of aromatic compounds (i)a) ranges from 40 to 53% by mass, preferably from 45 to 52% by mass, relative to the mass of the hydrocarbon mixture (i).

[0050] The composition according to the invention further contains non-cyclic paraffins (i)b) containing at least 5 carbon atoms.

[0051] The term "paraffins" refers, in a manner known per se, to branched alkanes (also called iso-paraffins or iso-alkanes) and unbranched alkanes (also called n-paraffins or n-alkanes).

[0052] The paraffins are preferably chosen from those comprising from 5 to 12 carbon atoms, more preferably from 5 to 9 carbon atoms, and better still from 5 to 8 carbon atoms.

[0053] Paraffins can be chosen from n-paraffins (or normal-paraffins, i.e. linear alkanes) and iso-paraffins (i.e. branched alkanes).

[0054] Particularly preferred are mixtures of n-paraffins and iso-paraffins chosen from those described above, preferably comprising a major proportion of iso-paraffins, with a mass ratio of the quantity of iso-paraffins to the quantity of n-paraffins greater than or equal to 3, preferably greater than or equal to 4 and better still within the range from 4 to 5.

[0055] The hydrocarbon mixture (i) advantageously contains from 5 to 10% by mass of n-paraffins and from 20 to 45% by mass of iso-paraffins.

[0056] Preferably, the content of paraffins (i)b) ranges from 32 to 45% by mass, more preferably from 35 to 42% by mass, relative to the mass of the hydrocarbon mixture (i).

[0057] The composition according to the invention further contains naphthenes (i)c).

[0058] The term "naphthenes" is used, in a manner known per se, to denote cyclic alkanes (or cycloalkanes) containing from 5 to 10 carbon atoms. Preferably, the naphthenes are chosen from cyclic alkanes containing from 5 to 10 carbon atoms, and more preferably from 6 to 9 carbon atoms.

[0059] Preferably, the content of naphthenes(i)c) ranges from 7 to 13% by mass, more preferably from 8 to 12% by mass, relative to the mass of the hydrocarbon mixture (i).

[0060] According to a preferred embodiment, the hydrocarbon mixture (i) is derived from plant raw materials. Thus, the mixture (i) is advantageously composed entirely of bio-sourced hydrocarbons. The original plant raw materials may be chosen, for example, from cereals (for example wheat, corn), rapeseed, sunflower, soybean, palm oil, sugar cane, beetroot, wood waste, straw, bagasse, grape marc, used vegetable cooking oils, algae, lignocellulosic materials. Particularly preferred are plant raw materials containing carbohydrates, such as cereals, sugar cane, beetroot, wood waste, straw, bagasse, grape marc, lignocellulosic materials which may be derived from the wood industry.

[0061] Preferably, so-called second generation (2G) or advanced plant material is used, in particular plant material that does not compete with the food resource.

[0062] The hydrocarbon mixture (i) is preferably obtained by transforming the plant material into alcohols containing 1 to 5 carbon atoms, preferably methanol and / or ethanol, which are converted into hydrocarbons in the presence of catalysts for dehydrating the alcohols and producing reaction intermediates which, catalytically, are then transformed into hydrocarbons.

[0063] The composition according to the invention also contains at least one ether.

[0064] Ethers, also called ether oxides or alkoxy alkyls, are compounds of formula RO-R', in which R and R', identical or different, represent an alkyl radical.

[0065] According to a preferred embodiment, the ether(s) are chosen from compounds of formula RO-R', in which R and R', identical or different, represent a C1 to C5 alkyl radical.

[0066] Preferably, R represents a C1 or C2 alkyl radical and R' represents a C3, C4 or C5 alkyl radical.

[0067] Particularly preferably, the oxygenated compound(s) (ii) are chosen from methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE), methyl tert-amyl ether (TAME), ethyl tert-amyl ether (TAEE), and mixtures of these compounds.

[0068] Particularly preferred is ethyl tert-butyl ether (ETBE).

[0069] According to a preferred embodiment, one or more ethers of plant origin, or bioethers, are used. The ether can be obtained in a renewable manner using, for example, a renewable alcohol, and an olefin from the thermal, catalytic or steam cracking of a renewable feedstock.

[0070] Bioethers can be produced, for example, by reaction between an alcohol and a generally branched olefin. They can be produced from renewable raw materials (in particular plant raw materials) using, for example, alcohols obtained by transformation (for example fermentation) of renewable raw materials, and olefins from cracking (thermal, catalytic, or steam cracking) of a renewable feedstock, or by dehydration of an alcohol. Preferably, the olefins are produced by steam cracking of bionaphtha which is a by-product from the production of renewable diesel by deoxygenation and isomerization of triglycerides of plant origin.

[0071] The composition has a total content of ether(s) ranging from 20 to 40% by mass, preferably from 22 to 35% by mass, and better still from 25 to 35% by mass, relative to the total mass of the fuel composition.

[0072] The composition according to the invention also contains butane, which can be chosen from n-butane (linear butane), iso-butane (2-methylpropane) and mixtures of these two compounds.

[0073] It is preferable to use a mixture of n-butane and iso-butane.

[0074] Butane can be derived from renewable raw materials. For example, it can be obtained by fractionating light hydrocarbons produced by catalytic cracking during the production of renewable diesel, which is obtained by deoxygenation and isomerization of triglycerides of vegetable origin, animal fats or used cooking oils.

[0075] The composition has a butane content ranging from 1 to 10% by mass, preferably from 1.5 to 8% by mass, and more preferably from 2 to 6% by mass, relative to the total mass of the fuel composition.

[0076] According to a preferred embodiment, the composition according to the invention comprises at most 2.5% by mass of olefins, preferably at most 2% by mass of olefins, more preferably at most 1% by mass of olefins, more preferably still at most 0.5% by mass of olefins.

[0077] The composition as described above generally has a research octane number (RON number) greater than or equal to 95, preferably greater than or equal to 99, and more preferably greater than or equal to 100, the RON being measured according to standard ASTM D 2699-86.

[0078] The above values ​​relate to the intrinsic octane number of the composition, i.e. without the addition of additional compounds such as octane booster additives.

[0079] The composition according to the invention may also contain one or more alcohols, preferably chosen from C1 to C6 alcohols, more preferably from C1 to C4 alcohols.

[0080] Examples include methanol, ethanol, isopropanol, and hexanol. Methanol and ethanol are particularly preferred.

[0081] According to a preferred embodiment, alcohols derived from renewable raw materials, and in particular of plant origin, also called bioalcohols, are used.

[0082] Such alcohols may be present in the composition according to the invention in a content ranging from 1 to 10% by mass, preferably from 2 to 8% by mass.

[0083] In addition to the basic compounds described above, the fuel composition according to the invention may also comprise one or more additives, chosen from those usually used in gasoline fuels.

[0084] In particular, the composition according to the invention may comprise at least one detergent additive ensuring the cleanliness of the engine. Such an additive may be chosen, for example, from the group consisting of succinimides optionally substituted by a polyisobutylene group, polyetheramines, betaines, Mannich bases and quaternary ammonium salts, for example those described in documents US4171959 and WO2006135881.

[0085] The composition may also comprise at least one lubrication additive or anti-wear agent, in particular (but not limited to) chosen from the group consisting of fatty acids and their ester or amide derivatives, in particular glycerol monooleate, and mono- and polycyclic carboxylic acid derivatives. Examples of such additives are given in the following documents: EP680506, EP860494, WO98 / 04656, EP915944, FR2772783, FR2772784.

[0086] Other additives may also be incorporated into the fuel composition according to the invention, such as anti-valve recession additives, anti-oxidant additives, octane number increasing additives, in particular chosen from amines, preferably aromatic, comprising or not oxygen.

[0087] The additives described above may be added to the fuel composition in an amount ranging, for each of them, from 10 to 5,000 ppm by mass, preferably from 50 to 1,000 ppm by mass and better still from 100 to 500 ppm by mass, relative to the total mass of the fuel composition.

[0088] According to a preferred embodiment, the composition comprises at least one additive, advantageously chosen from detergent additives, lubrication additives, anti-valve recession additives, antioxidant additives, octane number increasing additives, and mixtures of such additives.

[0089] The fuel compositions according to the invention have a lead content generally less than or equal to 5 mg / L (present for example in the form of tetraethyl lead) and, preferably, are unleaded, that is to say they do not contain lead or lead-containing compounds. They are also free of sulfur (maximum content of 10 ppm by weight). Preparation of fuel composition

[0090] The composition according to the invention can be prepared by simple mixing of its constituents.

[0091] A first non-limiting embodiment comprises the following steps: 1) preparation of a mixture of hydrocarbons (i) comprising from 35 to 55% by mass of aromatic compounds, from 30 to 50% by mass of non-cyclic paraffins containing at least 5 carbon atoms and from 5 to 15% by mass of naphthenes; then 2) mixing from 50 to 79% by mass of said mixture (i) with 20 to 40% by mass of one or more ethers and from 1 to 10% by mass of butane.

[0092] A second non-limiting embodiment comprises the following steps: 1') preparing a base B comprising the hydrocarbon mixture (i) and butane; then 2') mixing the base B with one or more ethers such that the content of ether(s) in the final composition is in the range of 20 to 40% by mass; and 3') optionally, adding butane, such that the amount of butane in the final mixture is in the range of 1 to 10% by mass.

[0093] A preferred variant of this second embodiment comprises the following steps: 1') preparation of a base B comprising the mixture of hydrocarbons (i) and butane; then 2') mixing 60 to 80% by mass of base B with 20 to 40% by mass of one or more ethers; and preferably 65 to 78% by mass of said base B with 22 to 35% by mass of one or more ethers.

[0094] The second embodiment and its preferred variant described above are preferred.

[0095] In this embodiment, base B is advantageously a bio-sourced base, that is to say it is advantageously obtained from alcohols resulting from the fermentation of plant raw materials, and preferably from plant raw materials containing carbohydrates, such as cereals, sugar cane, beetroot, wood waste, bakery waste, straw, bagasse, grape marc, lignocellulosic materials.

[0096] Such plant raw materials can be converted into biohydrocarbons by known catalytic conversion processes.

[0097] Likewise, the ether(s) are preferably bioethers.

[0098] Thus, the composition according to the invention can be entirely prepared from raw materials of renewable origin. Uses

[0099] The invention also relates to the use of the composition as described above for supplying a spark-ignition engine. The engine may be of the direct injection or indirect injection type.

[0100] The fuel composition can be advantageously used both to power a conventional motor vehicle engine (known as "general public") and a high-performance, high-power spark-ignition engine, such as a motor racing vehicle engine. This may include, in particular, a naturally aspirated or turbocharged engine used in a competition vehicle (circuits or rallies), or a hybrid engine, i.e., a thermal engine coupled to an electric motor.

[0101] The invention also relates to the use of the composition as described above to reduce greenhouse gas emissions, determined in accordance with EU Directive 2018 / 2001 of the European Parliament and of the Council of December 11, 2018 on the promotion of the use of energy produced from renewable sources.

[0102] According to this Directive, the reduction in greenhouse gas emissions is determined in relation to a reference fossil fuel. The method for calculating the percentage reduction is more specifically defined in Annex V, Part C of the Directive.

[0103] The reduction in greenhouse gas emissions obtained by means of the fuel composition of the invention is at least 50%, preferably at least 60% and even better at least 65%, compared to the reference fossil fuel defined in the Directive.

[0104] The following examples are intended only to illustrate the invention, and should not be construed as limiting its scope. Examples

[0105] The following examples were produced using a bio-sourced hydrocarbon base B from the transformation of bio-alcohol from the transformation of biomass.

[0106] Base B has the following composition: [Table 1] Compounds Content (% by mass) Olefins 2,50 Aromatic compounds C6 to C11 46,6 C5 to C9 N-paraffins 6,3 C5 to C11 iso-paraffins, including 29,8 C5 to C7 22,3 Napthenes 12 Butane, of which 2,8 n-butane 1,5 iso-butane 1,3

[0107] A fuel composition C according to the invention was prepared by mixing: 66% by mass of base B; 34% by mass of ethyl tert-butyl ether (ETBE).

[0108] Fuel C according to the invention, containing a bio-sourced base in very high proportion as well as ETBE, made it possible to obtain satisfactory performance in terms of lower calorific value (LCV) and octane number (RON).

[0109] This composition provides a 65% reduction in greenhouse gas emissions, this reduction being determined in accordance with the method defined in Annex V Part C of EU Directive 2018 / 2001 of the European Parliament and of the Council.

Claims

1. Fuel composition comprising: (i) from 50 to 79% by weight of a mixture of hydrocarbons comprising: a) from 35 to 55% by weight of aromatic compounds; b) 30 to 50% by weight of non-cyclic paraffins containing at least 5 carbon atoms; and c) from 5 to 15% by weight of naphthenes; (ii) from 20 to 40% by weight of one or more ethers; and (iii) from 1 to 10% by weight of butane.

2. Composition according to the preceding claim, characterized in that the mixture of hydrocarbons (i) represents from 55 to 75% by weight, preferably from 60 to 70% by weight, with respect to the total weight of the fuel composition.

3. Composition according to either one of the preceding claims, characterized in that the aromatic compounds (i)a) are selected from alkylbenzenes comprising from 7 to 12 carbon atoms, and preferably from alkyl-benzene mixtures comprising from 7 to 10 carbon atoms.

4. Composition according to any one of the preceding claims, characterized in that the amount of aromatic compounds (i)a) ranges from 40 to 53% by weight, preferably from 45 to 52% by weight, with respect to the weight of the mixture of hydrocarbons (i).

5. Composition according to any one of the preceding claims, characterized in that the non-cyclic paraffins (i)b) are selected from paraffins comprising from 5 to 12 carbon atoms, preferably from 5 to 9 carbon atoms, and more preferentially from 5 to 8 carbon atoms.

6. Composition according to any one of the preceding claims, characterized in that the mixture of hydrocarbons (i) contains from 5 to 10% by weight n-paraffins and from 20 to 45% by weight iso-paraffins.

7. Composition according to any one of the preceding claims, characterized in that the amount of paraffins (i)b) ranges from 32 to 45% by weight, preferably from 35 to 42% by weight, with respect to the weight of the mixture of hydrocarbons (i).

8. Composition according to any one of the preceding claims, characterized in that the naphthenes (i)c) are selected from cyclic alkanes containing from 5 to 10 carbon atoms, and more preferentially from 6 to 9 carbon atoms.

9. Composition according to any one of the preceding claims, characterized in that the amount of naphthenes (i)c) ranges from 7 to 13% by weight, preferably from 8 to 12% by weight, with respect to the weight of the mixture of hydrocarbons (i).

10. Composition according to any one of the preceding claims, characterized in that the ether or ethers are selected from the compounds of formula R-O-R', wherein R and R', identical or different, represent a C1 to C5 alkyl radical.

11. Composition according to the preceding claim, characterized in that the ether or ethers are selected from the compounds of formula R-O-R', wherein R represents a C1 or C2 alkyl radical and R' represents a C3, C4 or C5 alkyl radical.

12. Composition according to the preceding claim, characterized in that the ether or ethers are selected from methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE), tert-amyl methyl ether (TAME), tert-amyl ethyl ether (TAEE), and mixtures of these compounds, and preferably the ether is ethyl tert-butyl ether (ETBE).

13. Composition according to any one of the preceding claims, characterized in that its total ether content ranges from 22 to 35% by weight, preferably from 25 to 35% by weight, with respect to the total weight of the fuel composition.

14. Composition according to any one of the preceding claims, characterized in that its butane content ranges from 1.5 to 8% by weight, preferably from 2 to 6% by weight, with respect to the total weight of the fuel composition.

15. Composition according to any one of the preceding claims, characterized in that it comprises no more than 2.5% by weight olefins, preferably no more than 2% by weight olefins, more preferentially no more than 1% by weight olefins, more preferentially still no more than 0.5% by weight olefins.

16. Composition according to any one of the preceding claims, characterized in that it further contains one or more alcohols, preferably selected from C1 to C6 alcohols, more preferentially from C1 to C4 alcohols, and more preferentially still ethanol or methanol.

17. Composition according to the preceding claim, characterized in that the alcohol or alcohols are present in an amount ranging from 1 to 10% by weight, preferably from 2 to 8% by weight.

18. Composition according to any one of the preceding claims, characterized in that the mixture of hydrocarbons (i) comes from plant raw materials, and preferably from second-generation plant materials.

19. Composition according to any one of the preceding claims, characterized in that it contains at least 50% by weight of one or more biosourced bases, preferably at least 60% by weight, more preferentially at least 65% by weight and better still at least 70% by weight of one or more biosourced bases, said biosourced base or bases preferably being of plant origin.

20. Composition according to any one of the preceding claims, characterized in that it further comprises at least one additive, advantageously selected from detergent additives, lubricity additives, additives for preventing valve recession, anti-oxidant additives, additives increasing the octane number, and mixtures of such additives.

21. Use of the composition as defined in any one of the preceding claims for feeding a controlled-ignition engine, preferably a naturally aspirated or turbocompressed controlled-ignition engine, or a hybrid engine, more preferentially an engine used in an automobile competition vehicle.

22. Use of the composition as defined in any one of claims 1 to 20 for reducing greenhouse gas emissions, determined in accordance with the Directive (EU) 2018 / 2001 of the European Parliament and of the Council.