FUEL COMPOSITION WITH LOW IMPACT ON CO2 EMISSIONS AND USE OF IT, ESPECIALLY IN NEW VEHICLES
Patent Information
- Application Number
- DE602023012704
- Authority / Receiving Office
- DE · DE
- Patent Type
- Patents
- Current Assignee / Owner
- Priority Date
- 2022-06-23
- Filing Date
- 2023-06-20
- Publication Date
- 2026-02-25
- Estimated Expiration
- 2043-06-20
AI Technical Summary
Existing gasoline-type fuels for new engines face challenges in meeting stringent requirements for cleanliness, storage stability, climate adaptability, safety, and environmental impact, particularly when formulated from bio-based sources, while avoiding toxic additives like organometallic compounds.
A fuel composition comprising 70-95% hydrocarbons (70-95% of aromatic compounds, non-cyclic paraffins, and naphthenes) and 5-30% ethers, with a high bio-based content, achieving high octane ratings and stability, and being free from harmful additives.
The composition ensures engine cleanliness, long-term storage stability, immediate start-up in varied climates, high safety, and significant reduction in greenhouse gas emissions, while meeting EN 228 specifications without toxic additives.
Description
[0001] The present invention relates to a fuel composition intended for vehicles with a spark-ignition engine (or petrol engine), and which has particular properties.
[0002] The invention also relates to the use of such a composition to power a spark-ignition engine, both in a conventional vehicle, particularly a car, and in a racing vehicle. The invention is especially concerned with the use of this composition as a primary fuel in a new engine.
[0003] Gasoline-type fuels marketed in Europe and usable in spark-ignition engines, particularly those in motor vehicles, must meet the specifications of the EN 228 standard, which defines a number of criteria such as, for example, a motor octane number (MON) greater than 85 and a research octane number (RON) of at least 95. As is well known, the octane number measures the resistance of a fuel used in a spark-ignition engine to auto-ignition.
[0004] These fuels are suitable for the vast majority of automotive engines.
[0005] However, special requirements arise when the petrol fuel is a so-called "first fill fuel", i.e. a fuel intended to power a new engine such as typically an engine equipping a new vehicle.
[0006] A new engine is defined as an engine that has not yet been used since its manufacture.
[0007] In particular, at the exit of the motor vehicle assembly lines, the tanks of new vehicles are filled in whole or in part with original equipment fuel, which corresponds to the very first fuel that powers the engine when the vehicle is put into circulation.
[0008] These original equipment fuels must meet very specific technical requirements.
[0009] A first set of requirements is imposed by the numerous starts and stops of vehicles that occur without the vehicle being driven as it leaves the assembly line, and which must be carried out without generating any engine fouling. Under these conditions, the original equipment fuels must protect new engines, guaranteeing their cleanliness and proper functioning until the vehicle is delivered to the first customer.
[0010] Furthermore, after manufacturing, motor vehicles are often stored and shipped worldwide before their first use. Original equipment fuel is thus stored for extended periods, often several months, in the vehicle before being consumed by the end user. Original equipment fuel must therefore exhibit excellent long-term storage stability, and in particular, perfect oxidation resistance.
[0011] Furthermore, the vehicle is often put into circulation in a sales location far removed from its place of manufacture: this may involve different continents with fundamentally different climatic conditions. However, starting the vehicle by the end user must not present any difficulty. To this end, the original equipment fuel must allow for immediate starting and smooth running of the vehicle regardless of its sales location, whether in hot regions or very cold countries.
[0012] Finally, because engines are started and stopped multiple times on the assembly lines and until final sale, assembly line operators are particularly exposed to emissions generated by fuel combustion. For this reason, it is also important that the original equipment fuel (OEM) has a high level of safety. In particular, the health, safety, and environmental requirements imposed by some car manufacturers can be stringent to prevent any fuel toxicity for operators who handle it regularly.
[0013] Thus, original equipment fuels are subject to technical, logistical and environmental requirements that are much higher than conventional fuels sold at service stations.
[0014] Furthermore, for all vehicles, and especially those intended for mass-market applications, there is a growing trend towards using fuels formulated from plant-based sources, particularly so-called "bio-based" fuels, in order to address environmental concerns and limit the use of fossil fuels. Thus, current environmental concerns are driving consumers to seek out more environmentally friendly fuels.
[0015] However, the use of fuel compositions based on bio-based materials must not be at the expense of fuel performance.
[0016] There is therefore a need to develop new fuel compositions to power spark-ignition engines that meet the requirements of modern vehicles, while being formulated from bases and / or compounds of renewable origin, also known as bio-based bases and compounds.
[0017] There is also a need to formulate fuels that meet the specific requirements of original equipment fuels, which can also be formulated from bio-based bases.
[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 those containing iron, lead, or manganese, are well-known octane-enhancing agents.
[0019] Thus, tetraethyl lead (TEL) was widely used as a highly effective octane-boosting agent. However, in most parts of the world, TEL and other organometallic compounds can now only be used in fuels in very small quantities, or not at all, because they can be toxic, damage engines, and are harmful to the environment.
[0020] Non-metal-based octane-improving agents include oxygenated compounds (e.g., ethers and alcohols) and aromatic amines. However, these additives also suffer from various drawbacks. 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 base fuel) to have a significant effect on the fuel's octane rating. NMA can also be toxic.
[0021] As an example, document US-A-4812146 describes compositions of unleaded gasoline fuels for racing engines that include 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 dialkylated benzenes, 5 to 6% by volume of at least one linear paraffin having 3 to 5 carbon atoms (denoted C3-C5), and one or more alkanols having 2 to 4 carbon atoms (denoted C2-C4), in sufficient quantity 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. Documents WO 2016 / 016336 A1 and US 2005 / 279018 A1 represent other examples of earlier fuel compositions.
[0023] 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 rating such as those described above.
[0024] Continuing its research into the development of fuel formulations for gasoline engines, the Applicant has now discovered a composition that meets the above objectives.
[0025] The present invention therefore relates to a fuel composition comprising: (i) 70 to 95% by mass of a hydrocarbon mixture comprising: (a) 5 to 30% by mass of aromatic compounds; (b) 50 to 90% by mass of non-cyclic paraffins containing at least 4 carbon atoms, consisting of a mixture of n-paraffins and iso-paraffins with a mass ratio of iso-paraffins to n-paraffins greater than or equal to 8; and (c) 1 to 15% by mass of naphthenes; and (ii) 5 to 30% by mass of one or more ethers, This composition has a density at 15°C, measured according to EN ISO 12185, within the range of 720 to 745 kg / m³ 3 and an olefin content of less than or equal to 2% by mass, relative to the total mass of the composition.
[0026] The compositions according to the invention are intended to power spark-ignition engines (or gasoline engines). These engines can be found in any vehicle equipped with an internal combustion engine, including conventional vehicles as well as plug-in and non-plug-in hybrid electric vehicles. The compositions according to the invention are also useful for powering a compression-ignition engine with mixed fuel (or "dual-fuel" engine).
[0027] These compositions comply with the specifications of the EN 228 standard. In particular, they have high RON and MON octane ratings.
[0028] The compositions according to the invention are particularly suitable for applications where constraints and requirements are extremely high, for example, in vehicles equipped with new engines. Thus, the compositions according to the invention constitute particularly high-performance original equipment fuels.
[0029] They are extremely stable during storage and withstand very wide temperature variations. They can be used in a wide range of climatic conditions, from hot to very cold regions. They do not clog engines and are safe to use.
[0030] The composition according to the invention also offers significant advantages for uses other than in vehicles equipped with new engines, such as, for example, consumer applications, particularly for passenger cars (or light vehicles). Where applicable, it must comply with the specifications of standard EN 228.
[0031] According to a particularly advantageous embodiment, the composition according to the invention can be prepared, in whole or in part, from biomass, and in particular from bases and / or compounds of plant origin. Specifically, the composition according to the invention can contain at least 30% by mass of one or more bio-based bases, preferably at least 50% by mass, more preferably at least 80% by mass, and even better at least 90% by mass of one or more bio-based bases. According to a particular embodiment, the composition according to the invention is entirely composed of bio-based bases (content exceeding 99.9% by mass).
[0032] Thus, it allows a very substantial gain in carbon dioxide equivalent (CO2) compared to a fossil base, on the order of at least 20% compared to a conventional fuel not containing hydrocarbons from biomass such as a fuel based on fossil (petroleum) hydrocarbons.
[0033] This CO2 equivalent gain is calculated over the entire life cycle of the fuel composition, from its manufacture to its use. It corresponds to a reduction in greenhouse gas emissions and can be determined by life cycle analysis, in accordance with ISO 14040-44.
[0034] The composition according to the invention also makes it possible to reduce greenhouse gas emissions. This reduction is 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.
[0035] The invention also relates to the use of the fuel composition defined above to power a spark-ignition engine.
[0036] According to a particularly advantageous embodiment, the composition according to the invention is used as initial fuel for a new engine, that is to say, as "original equipment" fuel. In other words, the composition is used to power a new engine of a motor vehicle.
[0037] Other objects, features, aspects and advantages of the invention will become even clearer upon reading the description and examples that follow.
[0038] In what follows, and unless otherwise indicated, the boundaries of a range of values are included in that range, in particular in the expressions: "between... and...", "within the range from ... to...", and "ranging from ... to ...".
[0039] 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 to".
[0040] Finally, in a manner known in itself, a compound in CN is designated as a compound containing in its chemical structure N carbon atoms. Fuel composition
[0041] The composition according to the invention contains a mixture (i) of hydrocarbons containing: a) 5 to 30% by mass of aromatic compounds; b) 50 to 90% by mass of non-cyclic paraffins containing at least 4 carbon atoms; and c) 1 to 15% by mass of naphthenes.
[0042] These contents are expressed in mass, relative to the mass of the mixture (i) of hydrocarbons.
[0043] The mixture (i) of hydrocarbons represents from 70 to 95% by mass, relative to the total mass of the fuel composition, preferably from 75 to 85% by mass, relative to the total mass of the fuel composition.
[0044] The aromatic compound(s) (i)a) are preferably chosen from alkylbenzenes comprising 7 to 12 carbon atoms. Alkylbenzenes are defined as derivatives of benzene in which one or more hydrogen atoms are replaced by one or more alkyl groups.
[0045] The aromatic compound(s) may in particular be chosen from 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), 1-ethyl-3-methylbenzene, mesitylene (1,3,5-trimethylbenzene), 1-ethyl-3,5-dimethylbenzene, and mixtures of these compounds.
[0046] We particularly prefer mixtures of aromatic compounds, and more specifically mixtures of alkyl-benzenes comprising 8 to 10 carbon atoms such as 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.
[0047] The content of aromatic compounds (i)a) represents from 5 to 30% by mass, preferably from 10 to 30% by mass, better from 15 to 25% by mass, and better still from 18 to 22% by mass, relative to the mass of the hydrocarbon mixture (i).
[0048] The composition according to the invention further contains non-cyclic paraffins (i)b) containing at least 4 carbon atoms.
[0049] The term "paraffins" refers, in a manner known per se, to branched alkanes (also called isoparaffins or isoalkanes) and unbranched alkanes (also called n-paraffins or n-alkanes). According to the invention, non-cyclic paraffins (i)b) are entirely composed of a mixture of n-paraffins and isoparaffins with a mass ratio of isoparaffins to n-paraffins greater than or equal to 8.
[0050] The said paraffins (i)b) are preferably chosen from those comprising 5 to 12 carbon atoms, more preferably 5 to 10 carbon atoms.
[0051] We particularly prefer mixtures of n-paraffins and iso-paraffins chosen from those described above, with a mass ratio of the quantity of iso-paraffins to the quantity of n-paraffins greater than or equal to 10, and preferably greater than or equal to 12. According to a preferred embodiment, this ratio is in the range of 8 to 20, preferably 10 to 18, and even better 12 to 17.
[0052] The hydrocarbon mixture (i) advantageously contains 3 to 10% by mass of n-paraffins and 40 to 87% by mass of iso-paraffins.
[0053] Preferably, the content of paraffins (i)b) is from 50 to 90% by mass, more preferably from 60 to 80% by mass, relative to the mass of the hydrocarbon mixture (i).
[0054] The composition according to the invention further contains naphthenes (i)c).
[0055] The term "naphthenes" refers, in a well-known manner, to cyclic alkanes (or cycloalkanes) containing 5 to 12 carbon atoms. Preferably, naphthenes are chosen from among cyclic alkanes containing 5 to 12 carbon atoms, and more preferably from 6 to 9 carbon atoms.
[0056] Preferably, the content of naphthenes(i)c is from 2 to 10% by mass, more preferably from 3 to 6% by mass, and even better from 3 to 5% by mass, relative to the mass of the hydrocarbon mixture (i).
[0057] According to a preferred embodiment, the mixture (i) of hydrocarbons is capable of being obtained at least 20% of its mass from the transformation of vegetable raw materials, preferably at least 30% of its mass, more preferably at least 50% of its mass, more preferably still at least 70% of its mass, and better still at least 80% of its mass.
[0058] In this embodiment, preferably the mixture (i) of hydrocarbons is derived at least 20% by mass from the transformation of vegetable raw materials, preferably at least 30% by mass, more preferably at least 50% by mass, more preferably still at least 70% by mass, and better still at least 80% by mass.
[0059] Thus, the mixture (i) is advantageously composed entirely or partially of bio-based hydrocarbons, and preferably entirely of bio-based hydrocarbons. The raw materials of plant origin can be chosen for example from cereals (wheat, corn), rapeseed, sunflower, soybeans, palm oil, sugar cane, beetroot, plant waste such as wood waste, straw, bagasse, grape pomace, used vegetable cooking oils, algae, lignocellulosic materials.
[0060] The composition according to the invention also contains one or more ethers.
[0061] Ethers, also known as ether-oxides or alkoxyalkyls, are compounds of formula RO-R', in which R and R', identical or different, represent an alkyl radical, typically a C1 to C7 radical.
[0062] The ether(s) are preferably chosen from the following compounds: methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE), methyl tert-amyl ether (TAME), ethyl tert-amyl ether (TAEE), diisopropyl ether (DIPE), and mixtures of these compounds. Methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE), and mixtures thereof are particularly preferred, and ethyl tert-butyl ether (ETBE) is even better.
[0063] According to a preferred embodiment, one or more bio-based ethers, i.e. of plant origin, are used.
[0064] The composition has an ether content ranging from 5 to 30% by mass, preferably from 15 to 25% by mass, and more preferably from 20 to 25% by mass, relative to the total mass of the fuel composition.
[0065] According to an advantageous embodiment, the composition according to the invention has an olefin content of less than or equal to 1.5% by mass, preferably less than or equal to 1% by mass, relative to the total mass of the fuel composition.
[0066] According to a preferred embodiment, the composition according to the invention comprises at most 1% by mass of benzene, preferably at most 0.5% by mass, and even better at most 0.1% by mass of benzene. In other words, its benzene content is less than or equal to 1% by mass, preferably less than or equal to 0.5% by mass, and even better less than or equal to 0.1% by mass, relative to the total mass of the composition.
[0067] The composition according to the invention may further comprise one or more alcohols, preferably selected from monoalcohols comprising 1 to 6 carbon atoms, more preferably from monoalcohols comprising 1 to 4 carbon atoms. Methanol and ethanol are preferred, with ethanol being particularly preferred.
[0068] The composition has a density at 15°C, measured according to EN ISO 12185, in the range of 720 to 745 kg / m³. Preferably, the density is in the range of 720 to 730 kg / m³.
[0069] According to a preferred embodiment, the composition according to the invention has a distillation endpoint, measured according to EN ISO 3405, greater than 190°C, preferably greater than or equal to 195°C.
[0070] The composition as described above generally has a research octane rating (RON) 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 EN ISO 5164.
[0071] It generally has a motor octane rating (MON rating) of 85 or higher, preferably 88 or higher, and more preferably 90 or higher, with MON being measured according to EN ISO 5163.
[0072] The above values refer to the intrinsic octane rating of the composition, i.e. without the addition of additional compounds such as octane booster additives.
[0073] In addition to the basic compounds described above, the fuel composition according to the invention may also include one or more additives, chosen from those commonly used in gasoline fuels.
[0074] In particular, the composition according to the invention may include at least one detergent additive ensuring the cleanliness of the intake circuit. Such an additive may, for example, be chosen from the group consisting of succinimides possibly substituted with a polyisobutylene group, polyetheramines, betaines, Mannich bases and quaternary ammonium salts, for example those described in documents US4171959 and WO2006135881.
[0075] The composition may also include at least one lubrication additive or anti-wear agent, including (but not limited to) those selected 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.
[0076] Other additives may also be incorporated into the fuel composition according to the invention, such as valve recession inhibitors and antioxidants, and octane improvers where appropriate.
[0077] The additives described above may be added in quantities ranging, for each of them, from 10 to 5000 ppm by mass, preferably from 50 to 1000 ppm by mass in the fuel composition.
[0078] According to a preferred embodiment, the composition comprises an additive package, that is, a combination of at least two different additives, advantageously selected from detergent additives, lubricant additives, valve anti-recession additives, and antioxidant additives. These additives are advantageously selected from those mentioned above.
[0079] The fuel compositions according to the invention generally have a lead content of less than or equal to 5mg / L (present for example in the form of tetraethyl lead) and preferably are lead-free, i.e. they do not contain lead or lead-containing compounds. Fuel composition preparation
[0080] The composition according to the invention can be prepared by simply mixing its constituents.
[0081] A non-exhaustive embodiment includes the following steps: 1) preparation of a mixture of hydrocarbons (i) comprising from 5 to 30% by mass of aromatic compounds, from 50 to 90% by mass of non-cyclic paraffins containing at least 4 carbon atoms consisting of a mixture of n-paraffins and iso-paraffins with a mass ratio of the quantity of iso-paraffins to the quantity of n-paraffins greater than or equal to 8, and from 1 to 15% by mass of naphthenes; then 2) mixing of 70 to 95% by mass of said mixture (i) with from 5 to 30% by mass of one or more ethers.
[0082] The hydrocarbon mixture (i) preferably comprises one or more bio-based bases at least 20% by mass, meaning that at least 20% by mass of the hydrocarbons were obtained from plant-based raw materials. More preferably, the hydrocarbon mixture (i) comprises one or more bio-based bases at least 30% by mass, more preferably at least 50% by mass, even more preferably at least 70% by mass, and even more preferably at least 80% by mass. These quantities are expressed as a percentage of the total mass of the hydrocarbon mixture (i).
[0083] The hydrocarbon mixture (i) may further include non-bio-based hydrocarbons, such as fossil (petroleum) hydrocarbons, preferably in a minor quantity, typically less than 80% by mass, preferably less than 70% by mass, more preferably less than 50% by mass, and better still less than 20% by mass. These quantities are expressed relative to the total mass of the hydrocarbon mixture (i).
[0084] According to a particularly preferred embodiment, the hydrocarbon mixture (i) is entirely made up of one or more bio-based bases.
[0085] Preferred bio-based bases include those produced from biomass, converted into bio-hydrocarbons by known catalytic conversion processes.
[0086] Similarly, the ether(s) are preferably derived from biomass.
[0087] Thus, the composition according to the invention can be entirely prepared from raw materials of plant origin. Uses
[0088] The invention also relates to the use of the composition as described above to power a spark-ignition engine. The engine may be of the direct injection type or of the indirect injection type.
[0089] The fuel composition can be used to power both a conventional (or "mainstream") motor vehicle engine and a high-power spark-ignition engine, such as a motor racing engine. This can include naturally aspirated or turbocharged engines used in racing vehicles (circuits or rallies), or hybrid engines, meaning internal combustion engines coupled with an electric motor, either plug-in hybrid (PHEV) or non-plug-in hybrid electric (HEV).
[0090] This disclosure also describes the use of the composition according to the invention as "original equipment" fuel, that is, as the initial fuel used in a vehicle with a new engine. In other words, the composition is used to power a new engine in a vehicle, including a motor vehicle or other type of vehicle (heavy goods vehicle, commercial vehicle, public transport vehicle, or other), preferably a motor vehicle.
[0091] The invention also relates to the use of the composition as described above to reduce carbon dioxide equivalent emissions, measured by life cycle analysis in accordance with ISO 14040-44. This reduction is typically determined relative to a fossil reference, in particular an equivalent petroleum-based fuel composition, such as a composition comprising identical levels of fossil-based hydrocarbons and the same ether(s) at the same level.
[0092] This disclosure finally describes the use of the composition as described above to reduce 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.
[0093] The examples below are intended solely to illustrate the invention, and should not be interpreted as limiting its scope. Examples
[0094] The following examples were carried out using a base B comprising 22% by mass of bio-based hydrocarbons from the transformation of bio-alcohol itself derived from the transformation of biomass.
[0095] Base B has the following composition: [Table 1] Compounds Content (% by mass) Olefins 0,7 Aromatic compounds in the C6 to C11 range 20,5 N-paraffins in C5 to C9 5,3 C5 to C11 isoparaffins 69,8 Nathenes 3,7
[0096] A fuel composition C was prepared by mixing: 77.6% by mass of base B, and 22.4% by mass of ETBE prepared from ethanol derived from biomass.
[0097] This composition has a density at 15°C, measured according to the EN ISO 12185 standard, of 722 kg / m³.
[0098] Its final distillation point, measured according to EN ISO 3405, is 195°C.
[0099] It has a research octane rating (RON, measured according to EN ISO 5164) of 101 and a motor octane rating (MON, measured according to EN ISO 5163) of 92.5.
[0100] Compared to a fuel of equivalent composition in which the hydrocarbons are of petroleum origin (i.e., comprising 77.6% by mass of fossil hydrocarbons and 22.4% by mass of ETBE), the C composition described above resulted in a 20% reduction in CO2 equivalents. This reduction was calculated by life cycle analysis, in accordance with ISO 14040-44.
Claims
1. A fuel composition comprising: (i) from 70 to 95% by mass of a hydrocarbon mixture comprising: a) from 5 to 30% by mass of aromatic compounds; b) from 50 to 90% by mass of noncyclic paraffins having at least four carbon atoms made up of a mixture of n-paraffins and iso-paraffins, with a ratio by mass of the quantity of iso-paraffins to the quantity of n-paraffins greater than or equal to 8; and c) from 1 to 15% by mass of naphthenes; and (ii) from 5 to 30% by mass of one or several of ethers, where this composition has a density at 15°C, measured according to the EN ISO 12185 standard, included in the range going from 720 to 745 kg / m3, and an olefin concentration less than or equal to 2% by mass, relative to the total mass of the composition.
2. The composition according to the preceding claim, characterized in that the hydrocarbon mixture (i) represents 75 to 85% by mass, relative to the total mass of the fuel composition.
3. The composition according to any one of the preceding claims, characterized in that the aromatic compounds (i)a) are selected from the alkyl-benzenes comprising 7 to 12 carbon atoms, and preferably from the alkyl-benzene mixtures comprising 8 to 10 carbon atoms.
4. The composition according to any one of the preceding claims, characterized in that the concentration of aromatic compounds (i)a) goes from 10 to 30% by mass, preferably from 15 to 25% by mass, and even more preferably from 18 to 22% by mass, relative to the total mass of the hydrocarbon mixture (i).
5. The composition according to any one of the preceding claims, characterized in that the noncyclic paraffins (i)b) are made up of a mixture of n-paraffins and iso-paraffins with the ratio by mass of the quantity of iso-paraffins to the quantity of n-paraffins greater than or equal to 10, preferably greater than or equal to 12.
6. The composition according to any one of the preceding claims, characterized in that the ratio by mass of the quantity of iso-paraffins to the quantity of n-paraffins is included in the range going from 8 to 20, preferably from 10 to 18 and even more preferably from 12 to 17.
7. The composition according to any one of the preceding claims, characterized in that the paraffin (i)b) concentration goes from 60 to 80% by mass, relative to the total mass of the hydrocarbon mixture (i).
8. The composition according to any one of the preceding claims, characterized in that the naphthenes (i)c) are selected from the cyclic alkanes having from 5 to 12 carbon atoms, and more preferably from 6 to 9 carbon atoms.
9. The composition according to any one of the preceding claims, characterized in that the concentration of naphthenes (i)c) goes from 2 to 10% by mass, preferably from 3 to 6% by mass, and more preferably from 3 to 5% by mass, relative to the mass of the hydrocarbon mixture (i).
10. The composition according to any one of the preceding claims, characterized in that the ether(s) are selected from the compounds with formula R-O-R', wherein R and R', identical or different, represent a C1 to C7 alkyl radical; preferably selected from methyl tert-butyl ether (MTBE), methyl tert-butyl ether (ETBE), tert-amyl methyl ether (TAME), tert-amyl ethyl ether (TAEE), di-isopropyl ether (DIPE), and mixtures of these compounds; more preferably methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE), and mixtures thereof; and even more preferably ethyl tert-butyl ether (ETBE).
11. The composition according to any one of the preceding claims, characterized in that the ether concentration thereof goes from 15 to 25% by mass, preferably from 20 to 25% by mass, relative to the total mass of the fuel composition.
12. The composition according to any one of the preceding claims, characterized in that the olefin concentration thereof is less than or equal to 1.5% by mass, preferably is less than or equal to 1% by mass, relative to the total mass of the fuel composition.
13. The composition according to any one of the preceding claims, characterized in that the benzene concentration thereof is less than or equal to 1% by mass, preferably less than or equal to 0.5% by mass, and more preferably less than 0.1% by mass, relative to the total mass of the fuel composition.
14. The composition according to any one of the preceding claims, characterized in that at least 20% of the mass of the hydrocarbon mixture (i) comes from the transformation of primary vegetable materials, preferably at least 30% of the mass thereof, more preferably at least 50% of the mass thereof, still more preferably at least 70% of the mass thereof and even more preferably at least 80% of the mass thereof.
15. A use of the composition as defined in any one of the preceding claims for supplying a spark-ignition engine.
16. The use of the composition as defined in any one of claims 1 to 14, as firstfilling fuel in a vehicle comprising a new engine, preferably an automotive vehicle.
17. The use of the composition as defined in claim 14 for reducing equivalent carbon dioxide emissions, measured by analysis of the lifecycle compliant with the ISO 14040-44 standard, compared to a fuel of equivalent composition in which the hydrocarbons are of petroleum origin.