RENEWABLE JET FUEL COMPOSITION HAVING A HIGH CONTENT OF NAPHTHENIC COMPOUNDS AND ASSOCIATED PREPARATION METHOD

Abstract

The present invention relates to a jet fuel composition obtained from renewable feedstocks comprising, relative to the total volume of the composition: a. from 50 to 90% by volume of at least one paraffinic base obtained from a hydrotreatment of esters and fatty acids, from a Fischer-Tropsch process or from a process for the production of jet fuel from alcohols, and which comprises at least 90% by weight of paraffins relative to the total weight of the paraffinic base, b. from 10 to 50% by volume of at least one C8-C16 naphthenic base, said naphthenic base being obtained from hydrogenation of a C8-C16 aromatic base, said aromatic base corresponding to the C8-C16 fraction of a biofuel produced by a process for converting at least one C1-C6 bioalcohol into fuel, and said aromatic base containing at least 60% by weight of aromatic compounds relative to the total weight of the aromatic base, said aromatic compounds comprising at least 50% by weight, preferably at least 80% by weight of benzene substituted by at least m methyl(s), m being an integer from 1 to 3, and optionally n C2-C5 alkyl(s), n being an integer from 1 to 3,
wherein said jet fuel composition comprises from 10 to 49% by weight of naphthenic compounds relative to the total weight of the composition.

Claims

1. A jet fuel composition obtained from renewable feedstocks comprising, relative to the total volume of the composition: a. from 50 to 90% by volume of at least one paraffinic base obtained from a hydrotreatment of esters and fatty acids, from a Fischer-Tropsch process, or from a process for the production of jet fuel from alcohols, and comprising at least 90% by weight of paraffins relative to the total weight of the paraffinic base, b. from 10 to 50% by volume of at least one C8-C16 naphthenic base, said naphthenic base being obtained from hydrogenation of a C8-C16 aromatic base, said aromatic base corresponding to the C8-C16 fraction of a biofuel produced by a process for converting at least one C1-C6 bioalcohol into fuel, and said aromatic base containing at least 60% by weight of aromatic compounds relative to the total weight of the aromatic base, said aromatic compounds comprising at least 50% by weight of benzene substituted by at least m methyl(s), m being an integer from 1 to 3, and optionally n C2-C5 alkyl(s), n being an integer from 1 to 3, wherein said jet fuel composition comprises from 10 to 49% by weight of naphthenic compounds relative to the total weight of the composition.

2. The jet fuel composition according to claim 1, comprising a quantity less than or equal to 15% by volume of aromatic compounds, relative to the total volume of the composition.

3. The jet fuel composition according to claim 1, wherein the naphthenic base comprises aromatic compounds and naphthenic compounds, and has a mass ratio between the naphthenic compounds and aromatic compounds higher than or equal to 1.

4. The jet fuel composition according claim 1, wherein the naphthenic base has a mass ratio between the mass amount of C9-C10 naphthenic compounds in the naphthenic base and the mass amount of C9-C14 naphthenic compounds in the naphthenic base higher than or equal to 0.10.

5. The jet fuel composition according to claim 1, additionally comprising from 1 to 18% by volume, relative to the total volume of the composition, of at least one C8-C16 aromatic base, said aromatic base corresponding to the C8-C16 fraction of a biofuel produced by a process to convert at least one C1-C6 bioalcohol to fuel, and wherein said aromatic base contains at least 60% by weight of aromatic compounds, said aromatic compounds comprising at least 50% by weight of benzene substituted by at least m methyl(s), m being an integer from 1 to 3, and optionally n C2-C5 alkyl(s), n being an integer from 1 to 3.

6. A method for producing a jet fuel composition obtained from renewable feedstocks, comprising at least the following steps: a) producing at least one paraffinic base from hydrotreatment of esters and fatty acids, from a Fischer-Tropsch process, or from a process to produce jet fuel from alcohols, said at least one paraffinic base comprising at least 90% by weight of paraffins, b) producing at least one C8-C16 naphthenic base comprising at least the following steps: i) producing a biofuel with a process to convert at least one C1-C6 bioalcohol to fuel, ii) hydrogenating the biofuel obtained after step i), to obtain a hydrogenated biofuel, iiii) recovering said C8-C16 naphthenic base by fractionating said hydrogenated biofuel obtained at step ii), and c) mixing from 50% to 90% by volume of the at least one paraffinic base produced at step a) with from 10 to 50% by volume of the naphthenic base produced at step b), to obtain a jet fuel composition comprising a paraffinic base and a naphthenic base.

7. The method for producing a jet fuel composition obtained from renewable feedstocks according to claim 6, wherein the hydrogenation is full.

8. The method for producing a jet fuel composition obtained from renewable feedstocks according to claim 6, wherein the hydrogenation is partial.

9. The method for producing a jet fuel composition obtained from renewable feedstocks according to claim 6, wherein the at least one paraffinic base obtained after step a) is produced from one or more oils chosen from among vegetable oils, animal fats, preferably non-comestible highly saturated oils, waste oils, by-products from the refining of vegetable oils or animal oil(s) containing free fatty acids, tall oils, and oils produced by bacteria, yeasts, algae, prokaryotes or eukaryotes.

10. The method for producing a jet fuel composition according to claim 6, additionally comprising: a step d) to produce at least one C8-C16 aromatic base, comprising at least the following steps: i) producing a biofuel with a process for converting at least one C1-C6 bioalcohol to fuel, ii) recovering said C8-C16 aromatic base by fractionating said biofuel obtained at step i), said C8-C16 aromatic base comprising at least 60% by weight of aromatic compounds, said aromatic compounds comprising at least 50% by weight of benzene substituted by at least m methyl(s), m being an integer from 1 to 3, and optionally n C2-C5 alkyl(s), n being an integer from 1 to 3, and a step e) to add from 1% to 18% by volume, relative to the total volume of the composition of the aromatic base produced at step b) to the jet fuel composition comprising a paraffinic base and a naphthenic base obtained after step c).

11. The method for producing a jet fuel composition according to claim 6, wherein steps a), b), c) are conducted in separate processes.

12. The method for producing a jet fuel composition according to claim 10, wherein steps a), b), c), d) and e) are conducted in separate processes.

Description

DETAILED DESCRIPTION

[0060] The terms comprising and comprises as used herein are synonymous with including, includes or contains, containing, and are inclusive or without limits and do not exclude non-specified additional characteristics, elements, or steps of methods.

[0061] The expressions % by weight, and % by mass, have equivalent meaning and refer to the proportion of the weight of a product per 100 g of a composition comprising the same.

[0062] The expression % by volume refers to the proportion of the volume of a product per 100 L of a composition comprising the same.

[0063] By naphthenic compounds, it is meant C8-C16 cycloalkanes or C8-C16 polycycloalkanes, optionally substituted by C1-C5 alkyl groups.

Paraffinic Base of the Invention

[0064] By paraffinic base, it is meant a synthetic paraffinic fuel produced from raw material of non-petroleum origin.

[0065] Said synthetic paraffinic fuel is advantageously a renewable synthetic paraffinic kerosene (SPK) derived from hydrotreatment of esters and fatty acids (SPK-HEFA), or derived from a Fischer Tropsch (SPK-FT) process, or derived from a process to convert alcohol to isoparaffinic kerosene (SPK-ATJ).

[0066] The synthetic paraffinic fuel of the present invention is therefore a renewable fuel exclusively obtained from compounds of non-fossil origin.

[0067] Renewable synthetic paraffinic fuel SPK-HEFA can be produced from oil(s) of natural origin by a process of hydrogenating and deoxygenating fatty acids esters and free fatty acids, and from subsequent processing of the product including hydrocracking, hydroisomerization or isomerization, or a combination of these steps, and can include other conventional refining processes. In other words, the renewable synthetic paraffinic fuel SPK-HEFA is produced from hydrotreatment of esters and fatty acids from an oil of natural origin. It preferably complies with specification ASTM D7566:21 Annex 2.

[0068] An oil of natural origin is defined as an oil from a biomass source, not containing any mineral oil. In the description oil(s) of natural origin indifferently designates oils, fats and mixtures thereof. The said oil(s) of natural origin can contain one or more oils chosen from among vegetable oils, animals fats, preferably non-comestible highly saturated oils, waste oils, by-products from the refining of vegetable oil(s) or animal oil(s) containing free fatty acids, tall oils, and oils produced by bacteria, yeasts, algae, prokaryotes, or eukaryotes. Suitable vegetable oils are for example palm oil, palm kernel oil, soybean oil, rapeseed oil (rape or canola), sunflower seed oil, flax oil, bran oil, rice oil, corn oil, olive oil, castor oil, sesame oil, pine oil, groundnut oil, mustard oil, carinata oil, hemp oil, coconut oil, babassu oil, cotton oil, linseed oil, jatropha oil. Animal fats comprise tallow, lard, fat (brown and yellow fat), fish oil/fat, fat matter, milk fats.

[0069] The by-products from the refining of vegetable or animal oils are by-products containing free fatty acids which are removed from crude fats and oils by neutralisation, or vacuum or vapour distillation. One typical example is PFAD (Palm Fatty Acid Distillate). Waste oils comprise used cooking oils (waste food oils) and oils recovered from wastewaters such as sump oils/fats, gutter oils, sewage oils for example from water treatment plants, and waste fats from the food industry. Tall oils including crude tall oils, distilled tall oil (DTO), tall oil fatty acids (TOFA), preferably DTO and TOFA, can also be used in the present invention. Tall oil, also known as tallol, is a liquid by-product from the wood conversion Kraft process allowing isolation of the wood pulp used in the papermaking industry. Tall oil is essentially obtained when conifers are used in the Kraft process. After treating wood chippings with sodium sulfide in an aqueous solution, the isolated tall oil is alkaline. It is then acidified with sulfuric acid to produce crude tall oil. The oil(s) of natural origin used in the present invention also comprise oils produced by microorganisms, either natural microorganisms or genetically modified microorganisms, such as bacteria, yeasts, algae, prokaryotes or eukaryotes. In particular, such oils can be recovered using well known mechanical or chemical extraction methods.

[0070] Renewable synthetic paraffinic fuel SPK-FT is derived from the Fischer-Tropsch process and can be produced from solid biomass. It preferably complies with specification ASTM D7566:21 Annex 1. Thermochemical conversion of biomass (gasification and Fisher-Tropsch synthesis), also called BtL (Biomass to Liquid), comprises the following steps: pretreatment of the biomass (preparation, trituration, roasting), gasification of the biomass (to obtain a syngas), purification of the syngas, Fisher-Tropsch synthesis to convert the gas to synthetic biofuel.

[0071] Irrespective of the aforementioned methods used, the synthetic paraffinic fuel can have been subjected to an isomerization step and/or distillation step before being incorporated in the composition of the invention, to remove the heavier linear paraffins which would compromise the cold behaviour properties of the jet fuel, in particular the freeze point which must be below 47 C. for Jet A1. The lightest compounds can also be separated by distillation to heed volatility and flash point requirements of jet A1. Irrespective of the aforementioned methods used, the renewable synthetic paraffinic fuel can have one or more of the following characteristics: [0072] paraffin content higher than 90% by weight, [0073] cycloparaffin content lower than 10% by weight, [0074] freeze point lower than 30 C., preferably lower than 40 C., for example lower than 47 C., [0075] density at 15 C. of between 730 and 780 kg/m.sup.3, [0076] distillation range of 145 C. to 315 C., [0077] isoparaffin content of 70% by weight or higher.

[0078] The renewable synthetic paraffinic fuel SPK-ATJ can correspond to specification ASTM D7566:21 Annex 5, but it can also be produced from any alcohol having 1 to 6 carbon atoms. The renewable fuel SPK-ATJ is obtained by dehydrating alcohols to produce olefins, followed by oligomerization of the olefins to obtain unsaturated hydrocarbon molecules in the boiling temperature range of SAFs. These unsaturated hydrocarbon molecules are then hydrogenated to produce the paraffinic base.

[0079] For implementation of the first method of the invention, the paraffinic base preferably complies with specification ASTM D7566:21.

[0080] The second and third methods of the invention can be implemented whether or not the paraffinic base complies with specification ASTM D7566:21.

Naphthenic Base of the Invention

[0081] The C8-C18 naphthenic base is produced by hydrogenation of a biofuel obtained with a process to convert a least one C1-C6 bioalcohol to fuel, followed by fractionation of the hydrogenated biofuel.

Step i): Production of a Biofuel

[0082] Production of the biofuel can be implemented by converting at least one C1-C6 bioalcohol in a catalytic process. The catalytic process can be performed on an aluminosilicate bed, preferably of zeolite type.

[0083] The C1-C6 bioalcohol mostly contains alcohols such as methanol, ethanol, propanols (n-propanol, i-propanol), butanols (n-butanol, i-butanol), pentanols (n-pentanols, i pentanol) and hexanols. The C1-C6 bioalcohol preferably contains more than 80% by weight of C1 to C6 alcohols, preferably more than 90% by weight of C1 to C6 alcohols.

[0084] The C1-C6 bioalcohol can be: [0085] Methanol obtained from biomass:

[0086] The biomass can particularly comprise wood fuels from forests and natural wooded land (e.g. sawdust), agricultural waste (e.g. rice husks, straw manure), energy crops exclusively grown for energy production (e.g. corn, oil palms), urban waste (e.g. (municipal solid waste and wastewaters) and biomass fuel derived from waste (e.g. wood pellets). The methanol of renewable origin can notably be obtained by converting a syngas high in CO/H2, this syngas being derived from biomass. The biomass can be gasified for example to produce a syngas high in CO/H2, this syngas then being converted to methanol in the presence of a catalyst. A process of this type is described for example in document WO2018134853A1. A syngas suitable for subsequent conversion to methanol can also be obtained by partial oxidization, in the presence of dioxygen, of a biogas containing methane and CO2, this biogas resulting for example from anaerobic digestion of biomass in the presence of one or more microorganisms. A process of this type is described for example in document WO2019060988A1. [0087] Methanol obtained from carbon dioxide:

[0088] There are several routes for conversion. Mention can be made for example of the catalytic conversion of carbon dioxide to methanol in the presence of hydrogen. Another route is to convert carbon dioxide to carbon monoxide by electrochemical conversion or by reverse water-gas shift in the presence of hydrogen. The carbon monoxide is then converted by catalytic conversion to methanol, in the presence of hydrogen. The hydrogen used for the different operations described above is obtained in particular by steam-methane reforming, by water-gas shift, or is produced by electrolysis from renewable energies such as solar energy, wind energy, geothermal energy, waves, or currents. [0089] Bioethanol produced from ethanolic fermentation, via the fermenting action of microorganisms, yeasts and/or bacteria, of at least one raw material of plant origin: Bioethanol can advantageously be obtained by: [0090] anaerobic fermentation of a substrate high in sugars derived from biomass, or [0091] anaerobic fermentation of a gas comprising CO, which may or may not be derived from biomass.

[0092] For anaerobic fermentation of a substrate high in sugars, the sugars are composed of chains of 6 or 5 carbons such as glucose, saccharose (dimer of glucose and fructose), xylose and arabinose.

[0093] This substrate may, for example, comprise or be directly derived from agrifood plants, sugar cane, sugar beet, sweet sorghum, or from depolymerization of starches of corn, wheat, barley, rye, sorghum, triticale, potato, sweet potato, cassava, and/or cellulose and hemicellulose of lignocellulosic biomass.

[0094] The substrate high in sugars can also be derived from lignocellulosic biomass by processing, comprising (i) a step to separate the lignin, cellulose and hemicellulose contained in the lignocellulosic biomass, followed by (ii) a step to convert the cellulose and/or hemicellulose to sugars. The obtaining of this type of substrate from lignocellulosic biomass is well known to persons skilled in the art. The substrate high in sugars is then subjected to fermentation, using microorganisms for example.

[0095] Ethanol can also be produced by anaerobic fermentation of a gas comprising CO. The substrate is then a gaseous substrate (gas) containing CO. This gas substrate can be a by-product from an industrial process such as the manufacture of ferrous metal products in steel-making plants in particular, the manufacture of non-ferrous products, oil refining processes, the gasification of coal and/or biomass or biochar, the production of electrical energy, the production of carbon black, the production of ammonia, the production of methanol, the manufacture of coke, catalytic cracking (in particular, the regeneration of catalysts yields carbon monoxide) and methane reforming.

[0096] In other embodiments, the gaseous substrate can derive from gasification of biomass, such as the by-products of biomass obtained when extracting and processing food products. The gasification process involves partial combustion of the biomass under restricted addition of air or oxygen. The resulting gas generally and mostly comprises CO and H2, with minimum volumes of CO2, methane, ethylene, and ethane. The CO content of the gaseous substrate is typically from 15% to 100% by volume, 15% to 95% by volume, 40% to 95% by volume, 40% to 60% by volume, and 45% to 55% by volume, or lies within a range defined by two of these limits.

[0097] Any microorganism capable of fermenting a gaseous substrate comprising CO to produce ethanol, can be used. [0098] Bioethanol produced from biomass by conversion of a syngas high in CO/H2, this syngas being derived from biomass.

[0099] The biomass can be gasified for example to produce a syngas high in CO/H2, this syngas then being converted to methanol in the presence of a catalyst. A process of this type is described for example in document WO2012003901. [0100] Any other alcohol having 3 to 6 carbon atoms obtained for example by: [0101] catalytic reaction of hydrogen with carbon dioxide or carbon monoxide; [0102] catalytic reaction of hydrogen with carbohydrates; [0103] ABE fermentation, a bacterial fermentation producing a mixture of ethanol, acetone, and butanol from carbohydrates such as glucose or starch; [0104] anaerobic fermentation of sugars derived from biomass, in particular to obtain propanol (iso or n), butanol (iso or n) or isoamyl alcohol; [0105] anaerobic fermentation of a mixture containing at least carbon monoxide, carbon dioxide and hydrogen, particularly to obtain propanol (iso or n), butanol (iso or n) or isoamyl alcohol.

Step ii): Hydrogenation of the Biofuel

[0106] Hydrogenation of the biofuel partially or fully hydrogenates the unsaturated compounds contained in the biofuel, and in particular partially or fully hydrogenates the aromatic compounds contained in the biofuel.

[0107] For example, hydrogenation is conducted in one or more fixed bed reactors (up or down flow) and in mixed phase, the fraction to be hydrogenated chiefly being in liquid phase.

[0108] Hydrogenation is conducted for example at a temperature of between 50 C. and 350 C., in particular between 100 C. and 300 C. It is conducted under a pressure preferably higher than 10 bara and in particular of between 20 bara and 80 bara.

[0109] A stream of hydrogen is fed into the or each reactor mixing with the stream of biofuel to be hydrogenated. The ratio of the volume flow rate of hydrogen to the volume flow rate of biofuel to be hydrogenated (not including recycled flow) is advantageously between 50 NL/L and 3000 NL/L, in particular between 100 NL/L and 500 NL/L. The hydrogen can be added to the flow of biofuel in several stages along the catalytic bed. The hourly space velocity is advantageously between 0.5 and 3 and in particular between 1 and 2 h 1. Excess hydrogen can be recycled back to the reaction zone after separation and compression.

[0110] The reaction is conducted in the presence of at least one catalyst comprising one or more Group VIII metals (typically Pt, Pd, Ni) supported on a substrate such as silica, alumina or any mixture of these two compounds, or carbon. The reaction can also be carried out in the presence of a catalyst of sulfide type containing an element of the VIB group (Cr, Mo, W) and an element of the VIIIB group (Fe, Ru, Co, Os, Co, Rh, Ir, Pd, Ni, Pt), or mixtures of these two groups of metals.

[0111] The hydrogenation step is preferably followed by a separation step of the light compounds, generally via stripping or distillation. This separation step allows the producing of a hydrogenated fraction of C8-C16 type, complying for incorporation in the aviation fuel.

[0112] In one variant, there is full hydrogenation of the biofuel. This means that the aromatic compounds contained in the biofuel are more than 99% hydrogenated.

[0113] In another variant, there is partial hydrogenation of the biofuel. Preferably, between 10% and 99%, more preferably between 10% and 90% by weight of the aromatic compounds contained in the biofuel to be hydrogenated, preferably between 30% by weight and 80% by weight of the aromatic compounds contained in the biofuel to be hydrogenated, are hydrogenated to naphthenic compounds.

[0114] All the above characteristics and variants concerning hydrogenation of the biofuel in the first method also apply to hydrogenation of the mixture in the second method of the invention, and to hydrogenation of the biofuel in the third method of the invention.

Step iii): Recovery of the C8-C16 Naphthenic Base

[0115] The hydrogenated biofuel obtained at step ii) is fractionated to recover the C8-C16 naphthenic fraction.

[0116] In the variant of the method in which the biofuel is partially hydrogenated, the naphthenic base recovered by fractionating the partially hydrogenated biofuel comprises a mixture of aromatic compounds and naphthenic compounds.

[0117] In this variant, the naphthenic base preferably comprises at least 60% by weight of naphthenic compounds, preferably from 70% to 95% by weight of naphthenic compounds, more preferably from 75% to 95% by weight of naphthenic compounds.

[0118] In this variant, the naphthenic base preferably has a mass ratio between the naphthenic compounds and aromatic compounds higher than or equal to 1, preferably higher than or equal to 2, preferably higher than or equal to 5, preferably between 1 and 99, preferably between 5 and 24, preferably between 5 and 10.

[0119] Preferably, the naphthenic base has a mass ratio between the mass amount of C9-C10 naphthenic compounds in the naphthenic base and the mass amount of C9-C14 naphthenic compounds in the naphthenic base higher than or equal to 0.10, preferably higher than or equal to 0.40, preferably higher than or equal to 0.50, preferably higher than or equal to 0.6, preferably between 0.70 and 0.95.

[0120] Preferably, the naphthenic base has a mass ratio between the mass amount of C9-C12 naphthenic compounds in the naphthenic base and the mass amount of C9-C14 naphthenic compounds in the naphthenic base higher than or equal to 0.60, preferably higher than or equal to 0.70, preferably higher than or equal to 0.80, preferably higher than or equal to 0.90, preferably between 0.80 and 0.999.

[0121] In particular, the production of the paraffinic and naphthenic bases according to the invention can use different renewable sources, and in particular using separate processes.

[0122] All the above characteristics and variants concerning the fractionating step of the hydrogenated biofuel in the first method also apply to the fractionating step of the hydrogenated mixture in the second method, and to the fractionating step of the mixture in the third method of the invention.

Aromatic Base of the Invention

[0123] The composition of the invention may additionally comprise a C8-C16 aromatic base. The C8-C16 aromatic base can be produced with the following steps: [0124] i) producing a biofuel by subjecting at least one C1-C6 bioalcohol, derived from at least one renewable feedstock, to alcohol-to-fuel conversion, [0125] ii) recovering, by fractionating, said C8-C16 aromatic base derived from said biofuel obtained at step i). [0126] Step i) to produce the biofuel is the same as the one described above for the production of the naphthenic base.

Step ii): Recovery of the C8-C16 Aromatic Base

[0127] The biofuel obtained at step i) is fractionated to recover the C8-C16 fraction to meet the volatility property requirements of aviation fuels.

[0128] The C8-C16 aromatic base of the invention can have one or more of the following characteristics: [0129] at least 60% by weight of C8-C16 aromatic compounds, in particular monoaromatic compounds, said aromatic compounds comprising at least 50% by weight, preferably at least 80% by weight of benzene substituted by at least m methyl(s), m being an integer from 1 to 3, and optionally n C2-C5 alkyls, n being an integer from 1 to 3, [0130] from 8% by weight to 15% by weight of naphthenic compounds, [0131] from 5% by weight to 15% by weight of isoparaffins, [0132] less than 5% by weight of n-paraffins.

[0133] It will be noted that said aromatic compounds, contained in an amount of at least 60% by weight, comprise benzene substituted by at least m methyl(s), and optionally n C2-C5 alkyl(s). These aromatic compounds can therefore comprise a mixture of benzene molecules substituted by at least m methyl(s), m being an integer from 1 to 3, and optionally benzene molecules substituted by at least m methyl(s), m being an integer from 1 to 3, and/or n C2-C5 alkyls, n being an integer from 1 to 3.

[0134] In particular, the production of paraffinic and naphthenic bases according to the invention can use different renewable sources, and in particular using separate processes.

Jet Fuel Composition of the Invention

[0135] Preferably, the composition of the invention comprises from 50% to 85% by volume, preferably from 55% to 80% by volume, more preferably from 55% to 75% by volume of the at least one paraffinic base.

[0136] Preferably, the composition of the invention comprises from 15% to 50% by volume, preferably from 20% to 45% by volume, more preferably from 25% to 45% by volume of the at least one naphthenic base.

[0137] Preferably, the composition of the invention comprises less than 18% by volume, preferably less than 10% by volume, preferably less than 8% by volume, preferably less than 5% by volume, preferably from 1% to 18% by volume, preferably from 1% to 10% by volume of the at least one aromatic base.

[0138] Preferably, the composition of the invention has a mass ratio of naphthenic compounds/aromatic compounds higher than 1, preferably higher than or equal to 2, preferably higher than or equal to 3, preferably between 3 and 5.

[0139] Preferably, the composition of the invention comprises from 15% to 48% by weight of naphthenic compounds, more preferably from 25% to 45% by weight of naphthenic compounds.

[0140] Preferably, the composition of the invention comprises an amount lower than or equal to 15% by volume of aromatic compounds, preferably lower than or equal to 8% by volume, more preferably lower than or equal to 5% by volume, relative to the total volume of the composition. Preferably, the composition of the invention comprises a quantity of aromatic compounds of between 1 and 15% by volume, preferably between 1 and 8% by volume, relative to the total volume of the composition.

[0141] The quantity of aromatic compounds included in the composition of the invention is defined by volume according to the specifications of standard ASTM D7566:21.

[0142] Advantageously, the fuel composition of the invention can conform to Jet A or Jet A1 requirements as defined by standard ASTM D7566:21 of July 2021, or in the DefStan 91-091 Issue which refers to standard ASTM D7566:21.

[0143] For example, the composition of the invention has a density of between 755 kg/m3 and 840 kg/m.sup.3, preferably between 775 kg/m.sup.3 and 840 kg/m.sup.3.

[0144] In particular, the contents of paraffinic base, naphthenic base, and aromatic base if any, in the jet fuel composition of the invention can be chosen so that the composition of the jet fuel of the invention complies with these requirements.

[0145] In one advantageous embodiment, the at least one paraffinic base and the at least one naphthenic base are obtained from separate treatments of renewable feedstocks, (from separate processes), in particular from separate renewable feedstocks. In one preferred embodiment, the jet fuel composition of the invention is composed of paraffinic, naphthenic, and aromatic (if present) bases obtained from renewable feedstocks.

[0146] In one embodiment, the composition of the jet fuel of the invention is free of components of petroleum origin.

[0147] The examples below illustrate the invention without however limiting the scope thereof.

EXAMPLES

Example 1

[0148] Two compositions C1 and C2 of the invention were prepared.

[0149] C1 comprises 68% by volume of HEFA conforming to the paraffinic base a) of the invention, and 32% by volume of naphthenic base b).

[0150] C2 comprises 61% by volume of HEFA conforming to the paraffinic base a) of the invention, and 39% by volume of the naphthenic base b).

[0151] The composition of the naphthenic base b) is given in following Table 1, and was determined by a GC2D method.

TABLE-US-00001 TABLE 1 Composition of naphthenic base b) C9-C10 C11-C12 C13-C14 content content content Isoparaffin content (wt. %) 3.60 3.19 0.35 0.02 n-paraffin content (wt. %) 0.51 0.36 0.00 0.02 Naphthene content (wt. %) 85.00 72.69 11.84 0.47 Saturates < C9 (wt. %) 4.84 Poly-naphthenes (wt. %) 6.05 Sum 100

[0152] Compositions C1 and C2, the HEFA base conforming to the paraffinic base a), and the naphthenic base b) have the characteristics detailed in the following Table (these characteristics were determined according to the standards specified in each column):

TABLE-US-00002 TABLE 2 Auto- BOCLE ignition pt. Density Viscosity Viscosity (mm) Naphthene ( C.) (kg/m.sup.3) @ 20 C. @ 40 C. ASTM content ASTM ASTM (mm.sup.2/s) (mm.sup.2/s) D5001 (wt. %) E659-15 D1298-06 ASTM D445-21 (19e1) GC2D HEFA 198 760.9 5.794 13.28 0.85 2.86 Naphthenic nd 799.4 2.638 4.262 nd 85.00 base b) (and 6.06 of polynaphthenes) C1 230 773.5 4.274 8.594 0.77 29.96 incl. 25.06 of C9-C10 & 4.53 of C11-C12 & 0.37 of C13-C14 C2 249 776.3 4.024 7.897 0.77 35.30 incl. 29.68 of C9-C10 & 5.24 of C11-C12 & 0.39 of C13-C14

[0153] The addition of the naphthenic base b) to a paraffinic base a) therefore allows compositions to be obtained having improved properties. In particular, the addition of the naphthenic base b) surprisingly improves the viscosity at 40 C. of the paraffinic base, and the lubricity thereof (BOCLE). This shows that it is possible to replace at least part of the aromatic base, frequently used in combination with paraffinic bases, by a naphthenic base and thereby reduce the formation of fine particles and the presence of contrails.

Example 2Comparative Composition Comprising a Naphthenic Base of Fossil Origin

[0154] A comparative composition C3* comprising 61% by volume of HEFA conforming to the paraffinic base a) of the invention (the base in Example 1) and 39% by volume of a fossil naphthenic base b) was prepared.

[0155] The composition of the naphthenic base b) was determined by GC2D and is given in the following table.

TABLE-US-00003 TABLE 3 Composition of naphthenic base b) C9-C10 C11-C12 C13-C14 content content content Isoparaffin content (wt. %) 22.44 0.03 5.75 14.74 n-paraffin content (wt. %) 18.35 0.35 8.66 8.97 Naphthene content (wt. %) 32.96 1.21 16.90 14.27 Saturates < C9 (wt. %) 0.02 Polynaphthenes (wt. %) 26.21 Monoaromatics 0.02 Sum 100

[0156] The comparative composition C3*, the HEFA base and naphthenic base b) have the characteristics detailed in the following Table (these characteristics were determined according to the standards specified in each column):

TABLE-US-00004 TABLE 4 Naphthenic HEFA base b C3* Auto-ignition ASTM E659-15 198 223 232 point ( C.) Density ASTM D4052 760.9 807.4 779.4 (kg/m.sup.3) Viscosity ASTM D445-21 1.484 1.7 1.573 @ 40 C. (mm.sup.2/s) Viscosity ASTM D445-21 2.099 2.415 2.208 @ 20 C. (mm.sup.2/s) Viscosity ASTM D445-21 nd 3.79 3.434 @ 0 C. (mm.sup.2/s) Viscosity ASTM D445-21 5.794 6.820 6.135 @ 20 C. (mm.sup.2/s) Viscosity ASTM D445-21 13.28 16.34 14.02 @ 40 C. (mm.sup.2/s) ABEL flash IP170 53.5 >70 58 point{grave over ()} ( C.) BOCLE (mm) ASTM D5001 0.84 0.74 (19e1) Naphthene 32.96 (incl. nd content (wt. %) 26.21 of polynaphthenes)

[0157] The naphthenic base b) of fossil origin comprises compounds having an average number of carbons higher than the naphthenic base b) of the invention used in Example 1. The viscosity of composition C3* is too high and does not comply with standard ASTM D7566.