Process for producing a jet fuel from lignin oil

Abstract

The present invention relates to a process for producing a jet fuel from a mixture of phenolic compounds, preferably from lignin oil, comprising a step of hydrodeoxygenation under specific conditions. The present invention also relates to a mixture of hydrocarbons and to a jet fuel obtained using this process.

Description

[0001] Process for preparing jet fuel from lignin oil

[0002] The present invention relates to a process for preparing jet fuel from a mixture of phenolic compounds, preferably from lignin oil, comprising a hydrodeoxygenation step under particular conditions.

[0003] The present invention also relates to a mixture of hydrocarbons and a jet fuel obtained according to this process.

[0004] Decarbonizing the aviation sector requires the increasing use of renewable fuels (RFs), which have a significantly lower carbon footprint compared to the fossil fuels currently used. However, the quantities of raw materials currently used (used cooking oils, first-generation vegetable oils) to produce RFs are limited and will not be sufficient to meet the entire RF demand in the near future. These raw materials also require a cracking / isomerization step because the chain lengths of the resulting compounds are too long (C18) to meet the fuel's cold-weather properties.

[0005] It is therefore necessary to use other biomass sources to produce SAF, for example, lignocellulosic biomass (wood, forestry residues, or agricultural byproducts). Lignocellulose, as its name suggests, is composed of cellulose, hemicellulose, and lignin. These components need to be separated and then processed, but lignin is difficult to process due to the very different nature of its components. Following conventional processes, lignin is very often polymerized (by condensation) and is difficult to convert into liquid fuel. This polymerized lignin is mainly used for combustion for its energy content, with little added value.

[0006] The reductive catalytic fractionation (RCF) process, as described in application WO 2022 / 90364, is a process that separates the different constituents of lignocellulosic biomass without damaging them. In particular, it yields carbohydrate pulp and lignin oil. However, RCF lignin oil is not directly usable as a solid alkali (SAF), primarily due to the presence of various oxygenated functional groups, such as methoxy, hydroxyl, and carbonyl groups. Furthermore, it differs significantly from other lignins produced by conventional processes, which are often solid at ambient conditions and / or contain sulfur. RCF lignin oil is, notably, liquid at ambient conditions, has a high monomer content, and a low molecular weight.

[0007] There is therefore a need for a process to produce a mixture of hydrocarbons or jet fuel from biomass derived from lignocellulose, in particular from RCF lignin oil.

[0008] In particular, there is a need for a process to produce a hydrocarbon mixture or jet fuel from lignocellulose biomass, especially from RCF lignin oil, reducing the mass oxygen content of said biomass by at least 60%, and preferably at least 70%. There is also a need for such a process to involve a minimum number of steps, specifically a process comprising a single hydrodeoxygenation step.

[0009] In particular, there is a need for a process to produce a mixture of hydrocarbons or jet fuel from biomass derived from lignocellulose, especially from RCF lignin oil, having a good yield in hydrocarbon mixture or jet fuel and / or producing jet fuel containing mainly aromatic and naphthenic compounds and / or having a very low oxygen content.

[0010] The present invention therefore relates to a process for preparing a mixture of hydrocarbons, comprising a step of hydrodeoxygenation of a mixture to be treated, the mixture to be treated comprising a mixture of phenolic compounds and a diluent, the mass content of the mixture of phenolic compounds being between 0.5% and 70% by mass, relative to the total mass of the mixture to be treated.

[0011] The inventors discovered that such a process makes it possible to obtain, from a mixture of phenolic compounds, a hydrocarbon typically comprising at least 50%, preferably at least 60%, and preferably at least 70% by mass of C9-C16 compounds, mainly representing a mixture of aromatic and / or naphthenic compounds, with a very low oxygen content (typically less than 1% by mass, and even less than 0.4% by mass). This process exhibits a very high yield and can advantageously be carried out in a single step.

[0012] The present invention further relates to a mixture of hydrocarbons obtained by the process according to the invention, comprising from 50% to 95% by mass of C9-C16 compounds relative to the total mass of the hydrocarbon mixture and / or having an average number of carbon atoms between 7 and 18, preferably between 8 and 15, preferably between 9 and 12.

[0013] Process for preparing a mixture of hydrocarbons

[0014] Hydrodeoxygenation stage

[0015] The process according to the invention includes a step of hydrodeoxygenation of a mixture to be treated, the mixture to be treated comprising a mixture of phenolic compounds and a diluent.

[0016] Hydrodeoxygenation, as used in the present invention, refers to a hydrogenolysis reaction that removes oxygenated functional groups (e.g., hydroxyl, ether (methoxy, for example), carboxyl, etc.) from a hydrocarbon. This reaction is preferably carried out under high hydrogen pressure and in the presence of a catalyst.

[0017] Preferably, the hydrodeoxygenation step is carried out at a temperature less than or equal to 350°C, preferably less than or equal to 330°C, preferably less than or equal to 325°C, preferably less than or equal to 320°C, preferably less than or equal to 300°C, preferably less than or equal to 299°C, preferably less than or equal to 290°C, preferably between 200°C and 350°C.

[0018] The reaction temperature preferably corresponds to the average temperature of the adiabatic catalytic bed, or, as used by those skilled in the art, the WABT (weighted average bed temperature). The WABT per adiabatic catalytic bed is defined as WABT = (inlet temperature - 2 x outlet temperature) / 3.

[0019] Preferably, the hydrodeoxygenation step is carried out in the presence of a catalyst comprising nickel, cobalt, molybdenum, tungsten, or mixtures thereof, preferably comprising oxides, sulfides, or phosphides of nickel, cobalt, molybdenum, tungsten, or mixtures thereof, preferably in metallic, oxide, phosphide, or sulfuric form. The catalyst preferably has an active phase selected from (i) the metals, oxides, phosphides, or sulfides of Ni, Mo, W, Co, or mixtures of NiCo, NiW, NiMo, CoMo, NiCoW, NiCoMo, NiMoW, and CoMoW, preferably comprising molybdenum or nickel, preferably molybdenum, preferably the catalyst being selected from NiMoS, CoMoS, and Ni x P y , where the x / y ratio is between 0.3 and 3, advantageously from NiMoS and CoMoS, (ii) metals or mixtures of metal alloys from Group 10 and Group 11 of the periodic table. Alternatively, the catalyst is Ni x P y.

[0020] The main drawback of using NiMo / CoMo sulfide catalysts is the need to introduce sulfide reagents to maintain catalyst activity and stability. Transition metal phosphide-based catalysts introduced for hydrotreating reactions can be attractive alternatives to expensive noble metal-based catalysts. One advantage of this class of catalysts is that the use of a sulfur-introducing reagent is not required to maintain activity.

[0021] A phosphide is a compound containing the P ion 3-Binary phosphides, composed solely of phosphorus and a less electronegative element, and polyphosphides, composed of anionic chains and / or phosphorus clusters, are two main types of phosphides. Used as catalytic materials, metal-rich phosphides exhibit excellent activity in hydrogenation, hydrodesulfurization (HDS), hydrodenitrogenation (HDN), and hydrodeoxygenation (HDO) reactions. Hydrogenation and hydrogenolysis (bond breaking) reactions are necessary for HDS, HDN, and HDO. Many metallic phosphides possess metallic properties and can therefore be used as HDS, HDN, and HDO catalysts. The composition of binary transition metal phosphides ranges from metal-rich M4P to phosphorus-rich MP15 (for example, nickel forms eight phosphides, from Ni3P to Ni5P2, Ni12P5, Ni2P, Ni5P4, NiP, NiP2 and NiP3).Many binary and ternary metal phosphides have metallic or semiconducting properties and are therefore potential catalysts for hydrogenation and hydrolysis.

[0022] The catalyst may have a supported or unsupported catalytic active phase.

[0023] Preferably, the catalyst is supported.

[0024] When the catalyst includes a support for the catalytic active phase, it is preferable for the support to have a high specific surface area. In one embodiment, the specific surface area should be at least 75 m². 2 / g, preferably at least 150 m 2 / g and more preferably at least 200 m 2 / g, this specific surface area can be measured by methods known in the art such as the BET method where the adsorption of nitrogen allows the specific surface area of ​​the solid material to be estimated.

[0025] Preferably, the catalyst is supported, for example on a refractory metal oxide, such as silica (SiO2, amorphous and / or mesoporous), alumina (Al2O3, crystalline, amorphous and / or mesoporous), cerium oxide (CeO2), titanium oxide (TiO2) and zirconium oxide (ZrO2), a carbon support (such as activated carbon, graphite, graphene, carbon black), silicon carbide, amorphous silica-aluminas, amorphous silica-aluminas-titaniums, phosphated alumina or phosphated silica alumina, sulfated zirconias, tungsten zirconias and zeolites, diatomite, hydroxyapatite, or a mixture of these, preferably chosen from silica (SiO2, amorphous and / or mesoporous), alumina (Al2O3, crystalline, amorphous and / or mesoporous), a carbon support (such as activated carbon, graphite, graphene, black carbon), or a mixture of these.Preferably, the support is chosen from silica, alumina, titanium oxide, zirconium oxide, carbon, cerium oxide, silicon carbide, silica-alumina, silica-alumina-titanium, phosphated alumina or phosphated silica alumina, sulfated zirconia, tungsten zirconia, a zeolite, or mixtures thereof.

[0026] According to one embodiment, the active phase of the catalyst does not include molybdenum carbide (MoC or Mo2C), preferably does not include Ni, Mo, W, Co carbide, preferably does not include any metal carbide.

[0027] Preferably, the hydrodeoxygenation step is carried out under a partial pressure of dihydrogen greater than or equal to 1.10 5 Pa, preferably greater than or equal to 20.10 5 Pa, preferably between 1.10 5 and 200.10 5 Pa, preferably between 10 and 10 5 Pa and 150.10 5 Pa, preferably between 20.10 5Pa and 120.10 5 Pa, preferably between 30.10 5 Pa and 100.10 5 Pa, preferably between 50.10 5 Pa and 90.10 5 Pa, preferably between 70.10 5 Pa and 90.10 5 Pa.

[0028] The high hydrogen pressure allows for the advantageous adjustment of the ratio between aromatic and naphthenic compounds in the resulting hydrocarbon mixture, thereby optimizing the properties of the final jet fuel. Furthermore, varying the hydrogen pressure allows for the formation of naphthenic compounds in the hydrocarbon mixture, which have a less negative impact on combustion emissions than aromatic compounds, primarily on the formation of fine particles and the presence of contrails.

[0029] Preferably, the hydrodeoxygenation step is carried out under a total pressure greater than or equal to 1.10 5 Pa, preferably between 1.10 5and 250.10 5 Pa, preferably between 10 and 10 5 Pa and 180.10 5 Pa, preferably between 30.10 5 Pa and 150.10 5 Pa, preferably between 50.10 5 Pa and 120.10 5 Pa, preferably between 70.10 5 Pa and 90.10 5 Pa.

[0030] Preferably, if the process is carried out in batches, the hydrodeoxygenation step is carried out with a mass ratio of lignin to catalyst in the reactor of 1.0 to 10, for a duration of 1 to 10 hours, preferably 2 to 5 hours, preferably 4 hours.

[0031] Alternatively, if the process is implemented continuously, the hydrodeoxygenation step has a mass flow rate per hour (WHSV) defined by the ratio of the mass flow rate of liquid feed to the mass of catalyst loaded into the reactor, ranging from 0.1 to 10 h -1preferably ranging from 0.2 to 5 hours -1 , preferably ranging from 0.25 to 2.5 h' 1 .

[0032] Preferably, the hydrodeoxygenation step is carried out in a single step. Therefore, the hydrodeoxygenation step is preferably implemented in a single reactor. Consequently, it is preferably unnecessary to use two or more reactors to transform the mixture of phenolic compounds into a mixture of hydrocarbons.

[0033] In one embodiment, the hydrodeoxygenation step is implemented in a reactor operating in batch mode or in continuous mode, preferably in continuous mode.

[0034] In one embodiment, the hydrodeoxygenation step is carried out in a fixed bed reactor.

[0035] In one embodiment, the hydrodeoxygenation step is implemented in a continuously stirred tank reactor (CSTR).

[0036] In one embodiment, the hydrodeoxygenation step is carried out in a bubbling bed reactor or a slurry-type reactor.

[0037] According to one embodiment, the process according to the invention further includes a step of fractionating the hydrocarbon mixture, in particular to produce jet fuel.

[0038] The fractionation stage can also produce a naphtha fraction and a diesel fraction.

[0039] In one embodiment, the process may further include a step of stripping the hydrocarbon mixture obtained at the end of the hydrodeoxygenation step, and before the optional fractionation step. This step removes light compounds, such as C1-C4 hydrocarbons, and gaseous components including H2, H2S, CO2, and possibly CO and NH3. In another embodiment, the process may further include a step of recycling the excess dihydrogen remaining at the end of the hydrodeoxygenation step.

[0040] Mixture to be treated

[0041] The mixture to be treated in the process of the invention comprises, in relation to the total mass of the mixture to be treated, between 0.5% and 70% by mass of the mixture of phenolic compounds.

[0042] Preferably, the mixture to be treated comprises, relative to the total mass of the mixture to be treated, between 1% and 60% by mass of the mixture of phenolic compounds, preferably between 1.5% and 50% by mass, preferably between 2% and 40% by mass, preferably between 3% and 30% by mass, preferably between 4% and 20% by mass, preferably between 5% and 15% by mass. Preferably, the mixture to be treated comprises, relative to the total mass of the mixture to be treated, between 0.5% and 20% by mass of the mixture of phenolic compounds.

[0043] Diluent

[0044] The mixture to be treated in the process of the invention includes, in particular, a diluent.

[0045] The diluent is preferably an organic solvent, preferably having a boiling point greater than or equal to 15 °C and preferably less than or equal to 400 °C, preferably comprising one or more linear or branched alkanes and / or one or more naphthenic compounds and / or one or more aromatic compounds, preferably one or more linear alkanes, advantageously dodecane. It may also comprise a mixture of alkanes, such as, for example, a naphtha cut, kerosene, diesel fuel, or distillate from a refinery, or have a composition such as that of the hydrocarbon mixture obtained by the process according to the invention, or a fraction of the hydrocarbon mixture consisting of the mixture of hydrodeoxygenated phenolic compounds, or a mixture obtained after treatment and / or distillation or otherwise of the hydrocarbon mixture obtained by the process according to the invention.

[0046] In one embodiment, the diluent comprises, relative to the total mass of the diluent, at least 30% by mass, preferably at least 40% by mass, preferably at least 50% by mass, preferably at least 60% by mass, preferably from 40% to 100% by mass, preferably from 50% to 80% by mass, of C8-C24 compounds, preferably of C9-C16 compounds. Optionally, the diluent consists of C8-C24 compounds, preferably of C9-C16 compounds. This is advantageous because the diluent can then potentially be used in jet fuel (C8-C24 cut, preferably C9-C16).Furthermore, if the diluent contains functional groups that can react during the hydrodeoxygenation step (such as unsaturated bonds), it will necessarily react. The fact that the diluent contains a number of carbon atoms compatible with jet fuel production ensures that this byproduct is not lost but can be utilized in the jet fuel fraction. Conversely, a diluent containing fewer than 8 carbon atoms will consume dihydrogen but will not be utilized in the jet fuel fraction that we are trying to optimize.

[0047] In one embodiment, the diluent may consist of hydrocarbons of fossil origin. In this case, it does not include components of renewable origin.

[0048] Fossil-derived hydrocarbons usable in the process can advantageously be chosen from naphtha cuts, diesel cuts, kerosene cuts and distillate cuts, notably from the distillation of crude oil.

[0049] A fossil-derived naphtha cut typically has boiling points ranging from 15°C to 220°C. According to ASTM D86-12, it typically has an initial boiling point of 15°C to 42°C and a final boiling point of 220°C or lower. Such a naphtha cut generally originates from the direct distillation of crude oil or from fractionation after hydrotreating, hydroisomerization, and / or hydrocracking, and typically comprises C5-C12 compounds.

[0050] A fossil-based diesel fraction typically has boiling points ranging from 80°C to 360°C. According to ASTM D86-12, it typically has an initial boiling point of 180 to 240°C and a final boiling point of 360°C or lower. Such a diesel fraction generally originates from the direct distillation of crude oil or from fractionation after hydrotreating, hydroisomerization, and / or hydrocracking, and typically comprises C13-C25 compounds.

[0051] A fossil-based kerosene fraction typically has boiling points ranging from 130 °C to 300 °C. According to ASTM D86-12, it typically has an initial boiling point of 130 to 160 °C and a final boiling point of 220 °C to 300 °C. Such a kerosene fraction generally originates from the direct distillation of crude oil or from fractionation after hydrotreating and / or hydroisomerization and / or hydrocracking, and typically comprises C9-C15 compounds.

[0052] Fossil-derived distillate fractions typically have boiling points ranging from 375 to 600 °C. According to ASTM D86-12, they typically have an initial boiling point of 375 to 450 °C and a final boiling point of 500 to 600 °C. Such distillate fractions are generally obtained from the vacuum distillation of an atmospheric residue of crude oil, also known as vacuum distillates, and typically contain C20-C55 compounds.

[0053] Preferably, the diluent is the mixture of hydrocarbons obtained by the process according to the invention or the fraction of the mixture of hydrocarbons obtained by the process according to the invention consisting of the mixture of hydrodeoxygenated phenolic compounds.

[0054] Preferably, the diluent has an oxygen atom content of 5% or less by mass, relative to the total mass of the diluent, preferably 3% or less by mass, preferably 1% or less by mass, preferably 0.5% or less by mass, preferably between 0.01% and 5% by mass, and preferably the diluent is completely free of oxygen atoms. The oxygen atom mass content is defined by ASTM 5622, May 2017. The oxygen atom mass content is determined by elemental analysis of the diluent, according to the protocol defined below for determining the oxygen content of the hydrocarbon mixture.

[0055] The inventors made a surprising discovery: the presence of a diluent improves the yield of the hydrodeoxygenation step, even when carried out in a single step within a single reactor. Specifically, it reduces the mass concentration of oxygen atoms in the mixture being treated by at least 60%. It also improves the efficiency of the hydrodeoxygenation step, resulting in a hydrocarbon mixture with a low oxygen content. Furthermore, the dilution limits exothermicity, which is particularly important when the HDO reaction is performed in a single step.

[0056] Mixture of phenolic compounds

[0057] A mixture of phenolic compounds is understood to be a mixture of at least two phenolic compounds.

[0058] A phenolic compound is defined as any compound containing at least one hydroxyl group directly bonded to an aromatic ring, preferably a phenyl group. Therefore, it is any compound containing at least one phenoxy group, that is, a phenyl group substituted by at least one -OR group, where R is H, or an alkyl group in the C1-C4 position, preferably a methyl group. Preferably, phenolic compounds are either monomeric, that is to say they comprise one and only one phenoxy motif, that is to say one and only one aromatic ring bearing at least one -OR group, or dimeric, that is to say comprising two aromatic rings of which at least one phenoxy motif, or oligomeric, that is to say containing an assembly of at least two monomeric phenolic compounds assembled by covalent bonds typically having a molecular weight between 250 and 5000 g / mol and / or comprising at least three aromatic rings.Oligomeric phenolic compounds preferentially contain 3 or 4 monomeric phenolic compounds.

[0059] Preferably, monomeric phenolic compounds comprise between 6 and 12 carbon atoms, preferably between 8 and 12 carbon atoms, preferably between 8 and 11 carbon atoms.

[0060] Preferably, dimeric phenolic compounds comprise between 14 and 24 carbon atoms, preferably between 18 and 22 carbon atoms.

[0061] Preferably, oligomeric phenolic compounds comprise at least 26 carbon atoms.

[0062] Preferably, the mixture of phenolic compounds comprises 20% to 80% by mass, preferably 25% to 60% by mass, preferably 30% to 50% by mass, preferably 30% to 40% by mass, of monomeric phenolic compounds, relative to the total mass of the mixture of phenolic compounds.

[0063] Thus, preferably, the mixture of phenolic compounds comprises, relative to the total mass of the mixture of phenolic compounds, 20% to 80% by mass, preferably 25% to 60% by mass, preferably 30% to 50% by mass, preferably 30% to 40% by mass, of monomeric phenolic compounds comprising between 8 and 12 carbon atoms, preferably between 8 and 11 carbon atoms.

[0064] The mixture of phenolic compounds thus defined is preferably a lignin oil, preferably as defined below according to any one of the embodiments.

[0065] Monomeric phenolic compounds are preferably phenolic compounds of formula (I) as defined below.

[0066] The mixture of phenolic compounds preferably comprises a mixture of compounds of the following formula (I):

[0067] in which each and R2 is independently chosen from -O-CH3 and H, and each R3 is independently chosen from H, a methyl, an ethyl, a propyl, a propenyl, a 1-alkoxypropyl, a 2-hydroxyethyl and a 3-hydroxypropyl, preferably each RT and R2 is independently chosen from -O-CH3 and H, and each R3 is independently chosen from H, a methyl, an ethyl, a propyl, a propenyl, a 1-alkoxypropyl, and a 3-hydroxypropyl.

[0068] In particular, in formula (I):

[0069] - R2= - O- CH3 and / or

[0070] - R3 is independently chosen from a propyl and a 3-hydroxypropyl (-CH2-CH2-CH2-OH).

[0071] Preferably, the mixture of phenolic compounds comprises at least two, preferably at least three compounds of formula (I), preferably chosen from the compounds

[0072] Preferably, the mixture of phenolic compounds comprises at least two, preferably at least three compounds of formula (I), preferably chosen from compounds (la), (lb), (lc), (ld).

[0073] Preferably, the mixture of phenolic compounds includes the four phenolic compounds (la), (lb), (lc), and (ld) described above.

[0074] Preferably, the mixture of phenolic compounds includes the eight phenolic compounds (la), (lb), (lc), (ld), (le), (lf), (lg) and (lh) described above.

[0075] Compounds (la) to (lg), particularly (la) to (ld), are especially advantageous for the process. Indeed, these are C8-C12 compounds, and their presence in the mixture to be treated allows the formation, during the hydrodeoxygenation step, of hydrocarbons with a carbon number corresponding to that expected in jet fuel (C8-C24 cut, preferably C9-C16), which are therefore directly usable as jet fuel. Furthermore, they are at least partially transformed into naphthenic derivatives, which improve the properties of the jet fuel, particularly its freezing point.

[0076] Preferably, the mixture of phenolic compounds is a lignin oil, preferably an RCF lignin oil, i.e., obtained from a catalytic reduction fractionation process of lignocellulosic biomass, or an AAF lignin oil, i.e., obtained from an aldehyde-assisted fractionation process of lignocellulosic biomass, or a DAF lignin oil, i.e., obtained from a diol-assisted fractionation process of lignocellulosic biomass.

[0077] Preferably, the mixture of phenolic compounds is a lignin oil, preferably an RCF lignin oil, i.e., one obtained from a catalytic reduction fractionation process of a lignocellulosic biomass.

[0078] Lignin oil, preferably from one of the three processes listed above, preferably from a catalytic fractionation process, is more stable than other raw materials derived from lignin, for example from the paper industry, or pyrolysis oil from biomass, is more easily processable and allows a very high yield of the hydrodeoxygenation step to be obtained.

[0079] Preferably, the lignin oil, preferably RCF, has an average molecular weight of between 200 and 950 g / mol, preferably between 350 and 830 g / mol. The molecular weight distribution ranges from 150 to 2000 g / mol. The molecular weight distribution (and therefore the average molecular weight) is determined by gel permeation-size chromatography (GPC-SEC), for example, according to the following procedure: a lignin sample is solubilized in THF (5 mg.mL) 1) then filtered with a 0.2 µm PTFE membrane to remove any particles and prevent column clogging. GPC-SEC analyses are performed at 40 °C on a Waters E2695 equipped with a 300 mm long PL-Gel 3 µm Mixed-E column, using THF as the solvent at a flow rate of 1 mL / min 1 Detection is based on UV at a wavelength of 280 nm. Calibrations are performed with commercial polystyrene standards from Agilent.

[0080] Lignin oil, preferably RCF, with such a high molecular weight, is more fluid than other lignin-derived raw materials, for example those from the paper industry, or pyrolysis oil from biomass. As a result, it is more easily processed.

[0081] Lignin oil, preferably RCF, generally contains between 6 and more than 100 oxygenated hydrocarbons and an average number of carbon atoms between 20 and 60, preferably between 25 and 50, preferably between 30 and 45, and preferably between 35 and 40. The average number of carbon atoms represents the average number of carbon atoms per molecule. It can be calculated by dividing the molecular mass of the lignin oil by the carbon content of the lignin oil, determined by elemental analysis.

[0082] The lignin oil, preferably RCF, preferably used in the present invention, contains oxygen essentially in hydroxyl, etheric (including alkoxys), carboxylic, and carbonyl forms (aldehyde or ketone, optionally conjugated with the aromatic ring or carbon-carbon double bonds). Preferably, the mass of oxygen atoms in carboxylic and carbonyl forms in the lignin oil is less than or equal to 20% of the total mass of oxygen atoms present in the lignin oil, preferably less than or equal to 10%, preferably less than or equal to 5%, and even more preferably less than or equal to 2%, preferably between 0.1 and 20% by mass.Preferably, the lignin oil, preferably RCF, comprises, relative to the total mass of the lignin oil, an amount greater than or equal to 95% by mass, preferably between 97% and 100% by mass, preferably between 99% and 99.99% by mass, of carbon, hydrogen, and oxygen atoms. Preferably, the lignin oil comprises an undetectable amount of heteroatoms other than oxygen. By heteroatoms other than oxygen, we mean atoms other than carbon, hydrogen, and oxygen atoms. The lignin oil will therefore be less likely to deactivate catalysts, particularly the hydrodeoxygenation catalyst.

[0083] According to one embodiment, the lignin oil, preferably RCF, comprises, relative to the total mass of the lignin oil, less than 10% by mass, preferably less than 3% by mass, of sugars. Sugars are understood to mean carbohydrates and their derivatives composed of carbon (C), hydrogen (H), and oxygen (O) atoms without aromatic groups, generally with a hydrogen-oxygen ratio of about 2:1 and an oxygen-carbon ratio of about 1:1. This is then referred to as refined lignin oil.

[0084] According to another embodiment, the hydrodeoxygenation step can also be carried out on crude lignin oil, preferably RCF, i.e., lignin oil obtained before separation of water-soluble compounds, in particular sugars. According to this embodiment, the lignin oil is crude lignin oil and then comprises between 15 and 60% by mass of water-soluble compounds, relative to the total mass of crude lignin oil, preferably between 20 and 50% by mass, preferably between 30 and 40% by mass, and in particular between 10 and 50% by mass of sugars, preferably between 15% and 30% by mass.

[0085] Surprisingly, the presence of water-soluble compounds, particularly sugars in crude lignin oil, has a positive effect on the hydrodeoxygenation step, notably improving its yield.

[0086] Preferably, the lignin oil, preferably RCF, comprises from 9% to 80% by mass, preferably from 11% to 60% by mass, preferably from 13% to 50% by mass, preferably from 13% to 40% by mass, preferably from 25% to 40% by mass, of monomeric phenolic compounds, relative to the total mass of the lignin oil.

[0087] Preferably, the lignin oil, preferably RCF, comprises 0.4% to 25% by mass, preferably 1% to 20% by mass, preferably 2% to 18% by mass, preferably 5% to 18% by mass, preferably 8% to 15% by mass, of phenolic dimers, relative to the total mass of the lignin oil. Preferably, the lignin oil, preferably RCF, comprises 9% to 80% by mass, preferably 13% to 70% by mass, preferably 18% to 60% by mass, of lignin oligomers, relative to the total mass of the lignin oil.

[0088] Indeed, lignin oil, preferably RCF, is obtained by a catalytic reduction fractionation process of a lignocellulosic biomass, and comprises, at the end of this catalytic reduction fractionation process, a mixture of monomeric phenolic compounds (lignin monomers having a single aromatic ring, therefore a single phenolic motif), phenolic dimers and lignin oligomers, as defined above for the mixture of phenolic compounds.

[0089] So :

[0090] - preferably monomeric phenolic compounds comprise between 6 and 12 carbon atoms, preferably between 8 and 12 carbon atoms, preferably between 8 and 11 carbon atoms;

[0091] - preferably, the dimeric phenolic compounds comprise between 14 and 24 carbon atoms, preferably between 18 and 22 carbon atoms;

[0092] - preferably, oligomeric phenolic compounds comprise at least 26 carbon atoms.

[0093] A high content of monomeric phenolic compounds, such as that of the lignin oil defined in this application, improves the processability of the oil because these compounds are more soluble than dimers or oligomers. Consequently, a greater proportion of the lignin oil can be utilized, thereby increasing the carbon yield of the process. A high content of dimeric phenolic compounds also improves the processability of the lignin oil because they are more soluble than oligomeric phenolic compounds.

[0094] Furthermore, C8-C12 monomers, preferably C8-C11, are particularly advantageous for the process because they allow the formation, during the hydrodeoxygenation step, of compounds with a carbon number corresponding to that expected in jet fuel (C8-C24 cut, preferably C9-C16), which can therefore be directly used as jet fuel. Their presence in large quantities thus increases the jet fuel yield.

[0095] According to one embodiment, the lignin oil, preferably RCF, is a refined lignin oil and comprises, relative to the total mass of the refined lignin oil, 20% to 80% by mass, preferably 25% to 60% by mass, preferably 30% to 50% by mass, preferably 30% to 40% by mass, of monomeric phenolic compounds; and / or 1% to 25% by mass, preferably 3% to 20% by mass, preferably 5% to 18% by mass, of phenolic dimers; and / or 20% to 80% by mass, preferably 30% to 70% by mass, preferably 40% to 60% by mass, of lignin oligomers.

[0096] According to one embodiment, the lignin oil, preferably RCF, is a crude lignin oil and comprises, relative to the total mass of the crude lignin oil, 9% to 36% by mass, preferably 11% to 27% by mass, preferably 13% to 23% by mass, preferably 13% to 18% by mass, of monomeric phenolic compounds and / or 0.4% to 12% by mass, preferably 1% to 9% by mass, preferably 2% to 9% by mass, of phenolic dimers and / or 9% to 36% by mass, preferably 13% to 32% by mass, preferably 18% to 27% by mass, of lignin oligomers.

[0097] Monomeric phenolic compounds are preferably phenolic compounds of formula (I) as defined above.

[0098] Thus, preferably, the lignin oil (preferably the monomeric phenolic compounds of lignin oil) comprises a mixture of compounds of the following formula (I): in which each RT and R2 is independently chosen from -O-CH3 and H, and each R3 is independently chosen from H, a methyl, an ethyl, a propyl, a propenyl, a 1-alkoxypropyl, a 2-hydroxyethyl and a 3-hydroxypropyl, preferably each RT and R2 is independently chosen from -O-CH3 and H, and each R3 is independently chosen from H, a methyl, an ethyl, a propyl, a propenyl, a 1-alkoxypropyl, and a 3-hydroxypropyl.

[0099] In particular, in formula (I):

[0100] - R2= - O- CH3 and / or - R3 is independently chosen from a propyl and a 3-hydroxypropyl (-CH2- CH2-CH2-OH).

[0101] Preferably, the lignin oil, preferably RCF, (preferably monomeric phenolic compounds of lignin oil) comprises a mixture of at least two, preferably at least three compounds of formula (I), preferably selected

[0102] Preferably, the lignin oil, preferably RCF, (preferably monomeric phenolic compounds of lignin oil) comprises a mixture of at least two, preferably at least three compounds of formula (I), preferably selected from compounds (la), (lb), (lc), (ld).

[0103] Preferably, the lignin oil, preferably RCF, comprises, in relation to the total mass of the lignin oil, 9% to 80% by mass, preferably 20% to 80% by mass, preferably 11% to 60% by mass, preferably 25% to 60% by mass, preferably 13% to 50% by mass, preferably 30% to 50% by mass, preferably 13% to 40% by mass, preferably 25% to 40% by mass, preferably 30% to 40% by mass, of compounds of formula (I). Preferably, the lignin oil, preferably RCF, comprises, relative to the total mass of the lignin oil, from 0.5% to 20% by mass, preferably from 2% to 15% by mass, preferably from 3% to 11% by mass, of a compound of formula (la).

[0104] Preferably, the lignin oil, preferably RCF, comprises, relative to the total mass of the lignin oil, 2% to 25% by mass, preferably 3% to 20% by mass, preferably 5% to 18% by mass, of compound of formula (lb).

[0105] Preferably, the lignin oil, preferably RCF, comprises, relative to the total mass of the lignin oil, 0% to 8% by mass, preferably 0.2% to 5% by mass, preferably 0.4% to 3% by mass, of a compound of formula (lc).

[0106] Preferably, the lignin oil, preferably RCF, comprises, relative to the total mass of the lignin oil, 0.2% to 12% by mass, preferably 0.4% to 8% by mass, preferably 2% to 7% by mass, of a compound of formula (ld).

[0107] According to one embodiment, the lignin oil, preferably RCF, is a refined lignin oil, and it comprises:

[0108] - from 2% to 20% by mass, preferably from 5% to 15% by mass, preferably from 7% to 11% by mass, of a compound of formula (la), and / or

[0109] - from 5% to 25% by mass, preferably from 8% to 20% by mass, preferably from 12% to 18% by mass, of compound of formula (lb), and / or

[0110] - from 0.1% to 8% by mass, preferably from 0.5% to 5% by mass, preferably from 1% to 3% by mass, of a compound of formula (lc), and / or

[0111] - from 0.5% to 12% by mass, preferably from 1% to 8% by mass, preferably from 3% to 7% by mass, of compound of formula (ld), the percentages being related to the total mass of the refined lignin oil

[0112] According to another embodiment, the lignin oil, preferably RCF, is a crude lignin oil and comprises:

[0113] - from 0.5% to 9% by mass, preferably from 2% to 7% by mass, preferably from 3% to 5% by mass, of a compound of formula (la), and / or

[0114] - from 2% to 12% by mass, preferably from 3% to 9% by mass, preferably from 5% to 9% by mass, of compound of formula (lb), and / or

[0115] - from 0% to 4% by mass, preferably from 0.2% to 3% by mass, preferably from 0.4% to 2% by mass, of a compound of formula (lc), and / or

[0116] - from 0.2% to 6% by mass, preferably from 0.4% to 4% by mass, preferably from 2% to 4% by mass, of compound of formula (ld), the percentages being referred to the total mass of crude lignin oil.

[0117] Compounds (la) to (ld) are particularly advantageous for the process, since their presence in the mixture to be treated allows the formation, during the hydrodeoxygenation step, of hydrocarbons with a carbon number corresponding to that expected in jet fuel (C8-C24 cut, preferably C9-C16), which are therefore directly usable as jet fuel. Furthermore, they are at least partially transformed into naphthenic derivatives, which improve the properties of the jet fuel, particularly the freezing point. Finally, their presence in large quantities increases the jet fuel yield.

[0118] Preferably, the lignin oil (preferably the phenolic dimers of lignin oil) comprises a mixture of compounds of formulas selected from the following formulas (ll-a), (ll-b), (ll-c), (ll-d), (ll-e) and (ll-f):

[0119] and wherein each R4, R2, R4 and R5 is independently chosen from -O-CH3 and H, each R3 and R6 is independently chosen from H, a methyl, an ethyl, a propyl, a propenyl, a 1-alkoxypropyl, a 2-hydroxyethyl and a 3-hydroxypropyl, and each R7 is independently chosen from H, a methyl, and -CH2-OH, preferably each R^ R2, R4 and R5 is independently chosen from -O-CH3 and H, each R3 and R6 is independently chosen from H, a methyl, an ethyl, a propyl, a propenyl, a 1-alkoxypropyl, and a 3-hydroxypropyl, and each R7 is independently chosen from H, and -CH2-OH.

[0120] Preferably, the lignin oil, preferably RCF, contains oxygen, and the mass of oxygen atoms in carboxylic (carboxyl function) and carbonyl (carbonyl functions) form is less than or equal to 20% of the total mass of oxygen atoms present in the lignin oil, preferably less than or equal to 10%, preferably less than or equal to 5%, and even more preferably less than or equal to 2%, preferably between 0.1 and 20% by mass.

[0121] This explains at least in part the high chemical stability of RCF lignin oil compared to other lignin oils.

[0122] Preferably, the lignin oil, preferably RCF, has a viscosity at 25 °C less than or equal to 25 Pa.s, preferably between 0.010 and 20 Pa.s, preferably between 0.5 and 15 Pa.s, preferably between 1 and 10 Pa.s, preferably between 2.0 and 5.0 Pa.s, preferably between 3.0 and 4.0 Pa.s.

[0123] Viscosity at 25 °C can be determined according to the following protocol: Viscosity measurements were performed on a controlled-stress rheometer (Anton Paar MCR501). The sample temperature was controlled using a Peltier system (P-PTD200) with a solvent plate base and an evaporation blocker, with an accuracy of approximately 0.1 °C. For viscosities above 0.1 Pa·s, a PP25 geometry was used, while for viscosities below 0.1 Pa·s, a PP50 geometry was used. Viscosity was determined as a function of the shear rate at a rate of 5 measurement points per decade. The shear rate range was adjusted according to the temperature and the sample so that the measurements were performed in the Newtonian regime and above the instrument's minimum torque level. In the Newtonian regime, the average was calculated over 5 measurement points (1 decade).The RheoPlus software (Anton Paar GmbH, Austria) was used for data acquisition and analysis.

[0124] Preferably, the lignin oil, preferably RCF, is soluble in organic solvents or oily compounds, such as vegetable oils. By soluble, it is understood that at least 85% of the lignin oil in a mixture of lignin oil and an organic solvent consisting of 30% by mass of lignin oil relative to the total mass of the mixture, forms a homogeneous mixture at a temperature greater than or equal to 100°C, preferably greater than or equal to 150°C, preferably greater than or equal to 200°C.

[0125] Stage of catalytic reduction fractionation of a lignocellulosic biomass

[0126] Lignin oil, preferably RCF, which is preferably used in the process according to the invention, is obtained by catalytic reduction fractionation of a lignocellulosic biomass.

[0127] The term "lignocellulosic biomass" refers to biomass derived from plants or their by-products. Lignocellulosic biomass is composed of carbohydrate polymers (cellulose, hemicellulose) and an aromatic polymer (lignin).

[0128] The term "reductive catalytic fractionation" refers to a process that separates the different components of lignocellulose, as described above, into a solid carbohydrate pulp and a lignin oil. This separation is achieved by cleaving ester and ether bonds following high-temperature tandem solvolysis, hydrogenation, and hydrogenolysis, either batchwise or (semi-)continuously over a metallic catalyst in the presence of a reducing agent, such as hydrogen, or continuously. Near-complete delignification of hardwoods, such as birch and poplar, can be obtained without significant carbohydrate degradation and by limiting lignin condensation (the formation of C-C bonds, which makes lignin difficult to process due to its insoluble and highly viscous or solid state).

[0129] Preferably, catalytic reduction fractionation is carried out at a temperature between 180°C and 400°C, preferably between 200°C and 280°C.

[0130] Preferably, the catalytic reduction fractionation is carried out in the presence of a metallic catalyst, preferably supported, preferably comprising a platinum group metal (ruthenium Ru, rhodium Rh, palladium Pd, osmium Os, iridium Ir, platinum Pt) or nickel or cobalt or mixtures of these metals, preferably comprising ruthenium, preferably ruthenium supported on carbon.

[0131] Preferably, catalytic reduction fractionation is carried out under hydrogen pressure. Preferably, catalytic reduction fractionation is carried out at a hydrogen pressure between 5 and 150 bar, preferably between 10 and 80 bar, preferably between 25 and 50 bar (1 bar = 1 x 10⁻³). 5 Pa).

[0132] Preferably, the catalytic reductive fractionation is carried out for a duration of 1 hour to 8 hours, preferably from 2 hours to 4 hours.

[0133] Preferably, the catalytic reduction fractionation is carried out in the presence of a solvent, preferably an organic solvent, preferably selected from (1) linear or branched alcohols, preferably linear alcohols, advantageously methanol or ethanol, (2) acids, preferably acetic acid or propionic acid, and (3) esters, preferably methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, methyl butyrate, ethyl butyrate, or mixtures thereof. Optionally, the catalytic reduction fractionation is carried out in the presence of water or mixtures of water and the alcohols, acids, and / or esters mentioned above.

[0134] Preferably, the process according to the invention comprises a catalytic reduction fractionation step of a lignocellulosic biomass to obtain the mixture of phenolic compounds, preferably lignin oil. The catalytic reduction fractionation step of a lignocellulosic biomass is as described above.

[0135] The process according to the invention may further include a step of separating the solid pulp fractions from carbohydrates and lignin oil, produced at the end of the catalytic reduction fractionation step of a lignocellulosic biomass. The separation step is preferably a filtration or hydrocyclone separation of the solid pulp (the lignin oil being located in the liquid fraction), optionally followed by washing the solid residue and combining the different liquid fractions.

[0136] The catalytic reduction fractionation of lignocellulosic biomass (and the separation of the solid pulp fractions of carbohydrates and lignin oil) is for example as described in application WO 2022 / 090364.

[0137] An example of a general procedure for the catalytic reduction fractionation of lignocellulosic biomass, followed by the separation of the solid pulp fractions from carbohydrates and lignin oil, on a laboratory scale, in batches, is as described below:

[0138] A 2 L stirred batch reactor is loaded with 150 g of lignocellulosic biomass (particle size <10 mm), 800 mL of organic solvent, and 15 g of catalyst. The reaction vessel is sealed and flushed three times with N2 (8 bar) to remove residual oxygen. High-pressure H2 is applied to the reaction mixture before heating, and the reactor is stirred at 720 rpm. The reaction proceeds at 235 °C. After several hours, the reaction is stopped by rapid cooling with a stream of compressed air and water. The reactor contents are filtered to separate the solid fraction, containing carbohydrate pulp and catalyst, from the liquid fraction, containing lignin oil and some soluble sugar products. To collect all the liquid fraction, the solid residue is washed with ethanol.Next, the organic solvent used in the reaction and ethanol are removed from the liquid phase by rotary evaporation to give a brownish crude lignin oil of phenolic compounds, lignin oligomers and some soluble sugars.

[0139] According to a first embodiment, a triple liquid-liquid extraction with water and ethyl acetate at a mass ratio of 1 / 3 / 3 (crude lignin oil / ethyl acetate / water) can be carried out to separate the soluble sugars from the lignin derivatives. Evaporation of the ethyl acetate yields a lignin oil substantially free of sugars, composed of monomeric phenolic compounds, phenolic dimers, and phenolic oligomers.

[0140] According to another embodiment, the process for preparing a hydrocarbon mixture of the invention can also be carried out on a "crude" lignin oil, that is, the lignin oil obtained before the triple liquid-liquid extraction. The process according to the invention may further include a step of mixing the mixture of phenolic compounds (preferably lignin oil, preferably RCF lignin oil) and the diluent, preferably before the hydrotreating step.

[0141] mixture of hydrocarbons

[0142] The process according to the invention produces a mixture of hydrocarbons.

[0143] The present invention therefore also relates to a mixture of hydrocarbons obtained by the process according to the invention.

[0144] By hydrocarbon mixture is meant a mixture consisting essentially of hydrocarbon compounds comprising at least three carbon atoms, preferably at least five carbon atoms.

[0145] Since the mixture to be treated from which the hydrocarbon mixture is derived comprises a mixture of phenolic compounds and a diluent, the hydrocarbon mixture comprises a fraction consisting of the diluent and a fraction consisting of the hydrodeoxygenated mixture of phenolic compounds.

[0146] Preferably, the hydrocarbon mixture is bio-based, that is, derived from renewable organic matter.

[0147] The bio-based nature of the hydrocarbon mixture can be characterized by its carbon-14 content.

[0148] In the embodiment in which the diluent corresponds to the mixture of phenolic compounds hydrodeoxygenated by the process according to the invention, the composition of the hydrocarbon mixture is preferably expressed in relation to the total mass of the hydrocarbon mixture.

[0149] In embodiments where the diluent differs from a mixture of phenolic compounds hydrodeoxygenated by the process according to the invention, the composition of the product obtained by the process of the invention is preferably expressed as a percentage of the mass of the fraction of the hydrocarbon mixture consisting of the hydrodeoxygenated mixture of phenolic compounds. This allows, in these embodiments, the composition of the fraction resulting from the hydrodeoxygenation of the mixture of phenolic compounds (preferably lignin oil) to be highlighted without taking the diluent into account.Preferably, the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture) comprises 50% to 95% by mass, preferably 50% to 90% by mass, preferably 60% to 80% by mass, and preferably 65% ​​to 75% by mass of C9-C16 compounds relative to the total mass of the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture). C9-C16 compounds are defined as all compounds in the hydrocarbon mixture comprising 9 to 16 carbon atoms.

[0150] Preferably, the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture) has an average number of carbon atoms between 7 and 18, preferably between 8 and 15, preferably between 9 and 12.

[0151] The advantage of the process is also that it reduces the average number of carbon atoms in the mixture of phenolic compounds. It is thought that the process reduces the average number of carbon atoms in each molecule by preferentially breaking CO-carbon-oxygen bonds.

[0152] According to a first embodiment, the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture) comprises, relative to the total mass of the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture), aromatic compounds, preferably at least 90% by mass, preferably 93% to 100% by mass, preferably 95% to 100%, preferably 97% to 99.9% by mass, preferably 98% to 99% by mass, and less than 10% by mass, preferably 0% to 7% by mass, preferably 0% to 5% by mass, preferably 0.1% to 3% by mass, preferably 1% to 2% of naphthenic compounds.

[0153] According to a second embodiment, the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture) comprises, relative to the total mass of the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture), naphthenic compounds, preferably at least 90% by mass, preferably 93% to 100% by mass, preferably 95% to 100%, preferably 97% to 99.9% by mass, preferably 98% to 99% by mass, and less than 10% by mass, preferably 0% to 7% by mass, preferably 0% to 5% by mass, preferably 0.1% to 3% by mass, preferably 1% to 2%, of aromatic compounds.

[0154] According to a third embodiment, the hydrocarbon mixture (or the fraction consisting of the mixture of hydrodeoxygenated phenolic compounds) comprises a mixture of aromatic and naphthenic compounds. Preferably, the hydrocarbon mixture (or the fraction consisting of the mixture of hydrodeoxygenated phenolic compounds) comprises from 0.5% to 30% by mass, preferably from 0.8% to 20% by mass, preferably from 1% to 15% by mass, preferably from 2% to 10% by mass, of aromatic compounds relative to the total mass of the hydrocarbon mixture (or the fraction consisting of the mixture of hydrodeoxygenated phenolic compounds).

[0155] Preferably, the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture) comprises 30% to 95% by mass, preferably 40% to 90% by mass, preferably 50% to 80% by mass, preferably 60% to 75% by mass of naphthenic compounds relative to the total mass of the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture).

[0156] According to one embodiment, the catalyst for the hydrodeoxygenation step comprises a nickel-based active phase, preferably selected from NiMoS and Ni-P, and:

[0157] - the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture) comprises from 1% to 25% by mass, preferably from 2% to 20% by mass, preferably from 3% to 15% by mass of aromatic compounds relative to the total mass of the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture) and / or

[0158] - the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture) comprises from 75% to 99% by mass, preferably from 80% to 98% by mass, preferably from 85% to 97% by mass of naphthenic compounds relative to the total mass of the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture).

[0159] In particular, if the catalyst is NiMoS, preferably supported:

[0160] - the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture) comprises from 3% to 30% by mass, preferably from 4% to 25% by mass, preferably from 5% to 20% by mass of aromatic compounds relative to the total mass of the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture) and / or

[0161] - the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture) comprises 70% to 97% by mass, preferably 75% to 96% by mass, preferably 80% to 95% by mass of naphthenic compounds relative to the total mass of the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture).

[0162] In particular, if the catalyst is Ni-P, preferably supported:

[0163] - the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture) comprises from 1% to 15% by mass, preferably from 2% to 10% by mass, preferably from 3% to 5% by mass of aromatic compounds relative to the total mass of the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture) and / or

[0164] - the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture) comprises 85% to 99% by mass, preferably 90% to 98% by mass, preferably 95% to 97% by mass of naphthenic compounds relative to the total mass of the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture).

[0165] According to another embodiment, the catalyst for the hydrodeoxygenation step comprises an active phase based on CoMoS, and:

[0166] - the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture) comprises from 20% to 60% by mass, preferably from 30% to 50% by mass, preferably from 25% to 40% by mass of aromatic compounds relative to the total mass of the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture) and / or

[0167] - the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture) comprises 40% to 80% by mass, preferably 50% to 70% by mass, preferably 60% to 65% by mass of naphthenic compounds relative to the total mass of the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture).

[0168] According to another embodiment, the partial pressure of dihydrogen ranges from 3 to 150 bar, preferably from 20 to 120 bar, preferably from 30 to 100 bar and:

[0169] - the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture) comprises from 50% to 100% by mass, preferably from 70% to 99.9% by mass of aromatic compounds relative to the total mass of the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture) and / or - the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture) comprises from 0% to 50% by mass, preferably from 0.1% to 30% by mass of naphthenic compounds relative to the total mass of the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture).

[0170] According to another embodiment, the partial pressure of dihydrogen ranges from 60 to 100 bar, and:

[0171] - the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture) comprises from 0% to 40% by mass, preferably from 0.1% to 10% by mass of aromatic compounds relative to the total mass of the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture) and / or

[0172] - the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture) comprises from 60% to 100% by mass, preferably from 90% to 99.9% by mass of naphthenic compounds relative to the total mass of the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture).

[0173] Preferably, the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture) comprises, relative to the total mass of the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture), less than 5% by mass, preferably less than 3% by mass, preferably less than 2% by mass, preferably less than 1% by mass, preferably less than 0.5% by mass, preferably less than 0.4% by mass, preferably less than 0.2% by mass, preferably less than 0.05% by mass, preferably from 0.001% to 5% by mass of oxygen atoms. Oxygen atom mass content is defined as the ratio between the mass of all oxygen atoms present in the hydrocarbon mixture (or in the fraction consisting of the hydrodeoxygenated phenolic compound mixture) and the total mass of the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture).

[0174] The mass content of oxygen atoms is defined by elemental analysis of the hydrocarbon mixture, according to the following protocol:

[0175] Oxygen content was measured using the internal oxygen pyrolysis method. This method is based on ASTM 5622 of May 2017, and calibration was performed with BBOT (2,5-Bis(5-tert-butyl-benzoxazol-2-yl)thiophene), with the sample introduced directly into the pyrolysis tube.

[0176] Preferably, the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture, respectively) comprises, relative to the total mass of the hydrocarbon mixture (or the fraction consisting of the hydrodeoxygenated phenolic compound mixture, respectively), less than 8% by mass, preferably less than 5% by mass, preferably less than 3% by mass, preferably less than 1% by mass, preferably from 0% to 8% by mass, and preferably from 0.1% to 8% by mass of linear hydrocarbons. The remaining hydrocarbons are therefore cyclic hydrocarbons, with a saturated ring (preferably naphthenic compounds) or an unsaturated ring (preferably aromatic compounds).

[0177] Jet fuel

[0178] When the process according to the invention further includes a step of fractionating the hydrocarbon mixture, it produces in particular a jet fuel.

[0179] The present invention therefore also relates to a jet fuel obtained by the process according to the invention.

[0180] Jet fuel includes in particular the C9-C16 compounds of the hydrocarbon mixture.

[0181] Preferably, jet fuel is bio-based, that is, derived from renewable organic matter.

[0182] The bio-based nature of jet fuel can be characterized by its carbon-14 content.

[0183] Preferably, the jet fuel comprises, relative to the total mass of the jet fuel, preferably less than 4% by mass, preferably less than 3% by mass, preferably less than 2% by mass, preferably less than 1% by mass, preferably less than 0.5% by mass, preferably less than 0.4% by mass, preferably less than 0.2% by mass, preferably less than 0.1% by mass, preferably less than 0.05% by mass, preferably less than 0.01% by mass, preferably from 0.001% to 4% by mass of oxygen.

[0184] The mass content of oxygen atoms in the jet fuel is defined by the method described above for the hydrocarbon mixture. Preferably, the jet fuel comprises at least 50% by mass, preferably at least 60% by mass, preferably at least 70% by mass, preferably at least 80% by mass, preferably between 50% and 99.9% by mass, of aromatic and naphthenic compounds, relative to the total mass of the jet fuel.

[0185] Preferably, the jet fuel comprises from 0% to 40% by mass, preferably from 2% to 30% by mass, preferably from 3% to 20% by mass, preferably from 4% to 10% by mass, of aromatic compounds relative to the total mass of the jet fuel.

[0186] Preferably, the jet fuel comprises 60% to 100% by mass, preferably 70% to 98% by mass, preferably 80% to 97% by mass, preferably 90% to 96% by mass of naphthenic compounds relative to the total mass of the jet fuel.

[0187] The present invention further relates to the use of jet fuel as defined above,

[0188] (i) in a mixture with jet fuel resulting from the distillation and hydrotreating of petroleum, or

[0189] (ii) in a mixture with a synthetic jet fuel, preferably produced from the hydrotreated esters and fatty acids (HEFA) conversion process, the alcohols to jet conversion process, or the Fischer-Tropsch process, to power at least one aircraft engine.

[0190] The expressions "between ... and ..." and "ranging from ... to ..." should be understood inclusive of limits, unless otherwise specified.

[0191] The following examples will help to better understand the invention, but are not intended to be exhaustive.

[0192] EXAMPLES

[0193] 1: Viscosity and solubility of lignin oils

[0194] The viscosity of a lignin oil as used in the process of the invention was determined by the following protocol and compared with the viscosity of other oils: Viscosity measurements were performed on a controlled-strain rheometer (Anton Paar MCR501). The sample temperature was controlled using a Peltier system (P-PTD200) with a solvent plate base and an evaporation blocker with an accuracy of approximately 0.1°C.

[0195] For viscosities above 0.1 Pa·s, a PP25 geometry was used, while for viscosities below 0.1 Pa·s, a PP50 geometry was used. Viscosity was determined based on the shear rate at 5 measurement points per decade. The shear rate range was adjusted according to temperature and sample so that measurements were performed in the Newtonian regime and above the instrument's minimum torque level. In the Newtonian regime, the average was calculated over 5 measurement points (1 decade). RheoPlus software (Anton Paar GmbH, Austria) was used for data acquisition and analysis.

[0196] The viscosities of vegetable oils are taken from the following reference: Thermophysical Properties of Cotton, Canola, Sunflower and Soybean Oils as a Function of Temperature Edwin E. Garcia Rojas, Jane SR International Journal of Food Properties.

[0197] The results are summarized in the following table:

[0198] [Table 1] RCF lignin oil has a low viscosity compared to other lignin oils, such as those produced using the organosolv process. Its viscosity is closer to that of crude oil. This makes RCF lignin oil unique because it is more easily processed.

[0199] Furthermore, the solubility of RCF lignin oil in dodecane was compared with that of other lignin oils obtained by other biorefinery processes.

[0200] Conditions: Dodecane (22ml); temperature (220°C); lignin oil (0.150 g); time (1 h); rpm (700).

[0201] The results are presented in the following table:

[0202] [Table 2]

[0203] *ECCL: Early-stage Catalytic Conversion of Lignin (ECCL) reproduced from Z. Cao,

[0204] M. Dierks, MT Clough, IB Daltro de Castro and R. Rinaldi, Joule, 2018, 2, 1118-1133.

[0205] Example 2: Hydrodeoxygenation of lignin oil by a process according to the invention - effect of the temperature of the hydrodeoxygenation step on the distribution of compounds according to their carbon number

[0206] The RCF lignin oil used in this example was obtained from poplar wood in the presence of Ru / C as a catalyst and methanol as a solvent, by a process as described in WO 2022 / 090364 (example 1). It is therefore a refined RCF lignin oil obtained after a liquid-liquid extraction of crude RCF lignin oil, which removes the sugars present in the crude RCF lignin oil. It has the following characteristics:

[0207] [Table 3]

[0208] Lignin oil contains on average 39 carbon atoms per molecule before H₂DO: Calculation:

[0209] Average molar mass of lignin oil: 712 g / mol Elemental analysis of lignin oil: (%C= 64.5%; %H=7.4%; %O=25.6%)

[0210] Each molecule contains on average 459 g / mol of carbon = Average molar mass x percentage of mass corresponding to carbon. This corresponds to an average of 38 carbon atoms: average mass of carbon atoms per molecule / per atomic mass of carbon.

[0211] Before the hydrodeoxygenation step, the catalysts are synthesized: A Ni-P / SiO2 catalyst containing 65% by weight of Nickel and 5% by weight of Phosphorus on a SiO2 support (designated as Ni-P) was prepared according to the following procedure:

[0212] A commercial 65%Ni / SiO2 catalyst precursor was purchased from Strem Chemicals Inc. The catalyst precursor, as received, was impregnated with phosphorus using a phosphoric acid solution (H3PO4, 83% by weight aqueous solution).

[0213] The phosphoric acid solution (0.98 g) is dissolved in deionized water (1 mL) to which the catalyst precursor 65% Ni / SiO2 (2 g) has been added, and the mixture is mechanically stirred for 1 hour to obtain a uniformly mixed solution. The resulting uniformly mixed solution has a phosphorus / nickel (P / Ni) molar ratio of 0.1.

[0214] The mixture is then aged at room temperature for 12 hours, then heated in an oven at 80°C under an air atmosphere for 12 hours, thus preparing the dried Ni-P precursor.

[0215] A U-tube reactor was then filled with 1 gram of dried Ni-P precursor. The reactor temperature was increased to 550 °C at 1 °C / min with a H2 flow rate of 30 mL / min (standard milliliters). Once the temperature reached 550 °C, activation was carried out for 4 h. After activation, the U-tube was cooled to room temperature, and a gas mixture containing approximately 1% oxygen mixed with nitrogen was introduced for 1 h to obtain passivated Ni-P.

[0216] To maintain the activity and stability of the Ni-P catalyst, it is not necessary to introduce sulfide reagents into the mixture to be treated for the hydrodeoxygenation step.

[0217] Regenerated NiMo / Al₂O₃ or CoMo / Al₂O₃ catalysts were activated by a sulfidation process. The regenerated NiMo / Al₂O₃ or CoMo / Al₂O₃ catalysts were ground and sieved into a fine powder. Two g of powdered NiMo / Al₂O₃ or CoMo / Al₂O₃ catalyst were then loaded into the 50 mL reactor (Parr Instruments). The reactor was pre-purged with nitrogen. Optionally, when the reaction is performed in batch mode, 5 mL of dimethyl disulfide (DMDS, grade >99%, Sigma-Aldrich) in 25 mL of dodecane solvent can be added to the reactor. The H₂ pressure in the reactor is 35 bar. The reactor temperature is first increased (25°C / hour) to 230°C and maintained at this temperature for 4 hours (continuous stirring at 700 rpm). The temperature is then increased to 340°C (25°C / hour) and maintained at this temperature for 6 hours (continuous stirring at 700 rpm). The DMDS decomposes and reacts with hydrogen to generate H2S, which acts as a sulfurizing agent.The amount of DMDS used was greater than what was required for the complete sulfidation of the nickel and molybdenum phases. To maintain the activity and stability of the CoMoS and NiMoS catalysts, sulfide reagents can optionally be introduced into the mixture to be treated for the hydrodeoxygenation step.

[0218] The hydrodeoxygenation step is carried out in a 50 mL Parr reactor supplied by Parr Instrument Company, model 4590. The reactor vessel was loaded with 0.08 g of activated catalyst (80% by mass of lignin oil), 0.1 g of poplar lignin oil (0.7% by mass of the total feed), and 15.1 g of dodecane as the carrier liquid (97% by mass of the total feed). The poplar wood lignin was prepared according to the methods described in 2019 / 0233743 A1. The main characteristics of the poplar wood RCF lignin oil used in the invention are shown in Table 2.

[0219] The hydrodeoxygenation stage includes the following steps:

[0220] (i) Addition of lignin oil to the reactor vessel.

[0221] (ii) Addition of a diluent (dodecane) to the reactor vessel.

[0222] (iii) Addition of an activated catalyst to the mixture and hermetically sealing of the reactor vessel to the reactor head assembly.

[0223] (iv) Maintaining reactor pressure and temperature, including

[0224] (a) Purge the nitrogen gas in the mixture obtained in step (iii) at 0.5-0.7 bar three times and add hydrogen gas to achieve the desired pressure of between 0.5-100 bar in the reactor vessel.

[0225] (b) Heat the reactor vessel to the desired temperature of 250 to 340 °C and stir the reaction mixture at 600-700 rpm for 3 to 22 hours.

[0226] (v) Cool the reactor vessel to a temperature between 25 and 30 °C, release the unreacted hydrogen gas, remove the reactor vessel from the head assembly and separate the catalyst to obtain the liquid hydrocarbon product.

[0227] The conditions for the hydrodeoxygenation step in this example are as follows: [Table 4] Four temperatures were tested: 300 °C, 320 °C, 325 °C, and 340 °C. The distribution of compounds according to their carbon number in the products obtained was determined by the following method:

[0228] The product mixture obtained after the hydrodeoxygenation step in a batch reactor comprises a gaseous phase, a liquid phase containing water and hydrocarbon products, and a solid phase consisting of the catalyst. The gaseous products were collected in a Teldar bag and analyzed using a ThermoScientific Trace 1610 gas chromatograph equipped with a flame ionization detector (FID) and two thermal conductivity detectors (TCDs). The chromatograph is equipped with an RTX-1 3u capillary column and Molsieve 5A and Hayesep N packed columns to quantitatively determine the content of light C1-C4 hydrocarbons and permanent gases, including carbon monoxide and carbon dioxide, formed during the hydrodeoxygenation of RCF lignin oil.

[0229] The hydrocarbon product was separated from the catalyst and water by centrifugation.

[0230] The recovered catalyst was washed with ethanol and dried overnight at 80 °C. The coke present on the surface of the catalyst after the hydrodeoxygenation reactions was assessed by thermogravimetry.

[0231] An aliquot of the liquid phase containing the hydrocarbon product (1 mL) was added to phenanthrene as an internal standard (4–8 mg) and injected into a gas chromatograph (Agilent) equipped with a flame ionization detector (FID) and an HP-5 column to quantify the hydrocarbon content formed following the hydrodeoxygenation reaction. The GC furnace temperature was initially maintained at 40 °C for 1 min, then increased to 150 °C using a heating rate of 15 °C / min and maintained at this temperature for 3 min. The furnace temperature was then further increased to 305 °C using a heating rate of 10 °C / min and maintained at this temperature for 5 min. The injector and detector temperatures were maintained at 300 °C and 310 °C, respectively.

[0232] Gas chromatography / mass spectrometry (GC-MS) was performed to identify hydrocarbons present in the liquid phase and the mass spectra of each hydrocarbon product were compared to spectra available in the NIST and Wiley standard library.

[0233] Les hydrocarbures de la phase liquide comprennent des dérivés alkylés du cyclohexane et des composés naphténiques alkylés bi- et tri-cycliques de la gamme C5- C25, notamment cyclopentane, cyclopentane methyl-, cyclohexane, cyclohexane methyl-, cyclopentane ethyl-, cyclohexane ethyl-, cyclohexane propyl-, cyclohexane propenyl-, 1- Ethyl-4-methylcyclohexane, 1 H-lndene, octahydro-, Cyclohexane, butyl-, (2- Methylbutyl)cyclohexane, Cyclohexane, hexyl, Cyclohexane, (cyclopentylmethyl)-, Heptyl cyclohexane, Cyclohexane, 1 ,1 methylene bis-, Cyclohexane, octyl-, Cyclohexane, 1 ,1'- (1 ,2-ethanediyl)bis, 1-Cyclopentyl-4-(1-methylethyl)cyclohexane, Cyclohexane, 1 ,1'- ethylidenebis-, 1-Cyclohexyl-1-(4-methylcyclohexyl)ethane, Cyclohexane, 1,1'-(1-methyl- 1 ,2-ethanediyl)bis-, Cyclohexane, 1 ,T-(1 ,3-propanediyl)bis-, Cyclohexane, 1 ,1'-(1 ,4- butanediyl)bis-, Cyclohexane, 1 ,T-(1 ,4-butanediyl)bis-, Cyclohexane, 1 ,1'-(1- methylethylidene)bis-, 1-Cyclohexyl-1-(4-methylcyclohexyl)ethane,Cyclohexane, 1,1'- propylidenebis-, 1,1'-Bicyclohexyl, 2-propyl-, trans-, Cyclohexane, 1,1'-propylidenebis, Cyclohexane, 1,1'-(1,2-dimethyl-1,2-ethanediyl)bis-, 1 -Cyclohexyl- 1 -(4- ethylcyclohexyl)ethane, Cyclohexane, 1, 1'-(1-thyl-1,2-ethanediyl)bis-, Cyclohexane, 1,1'-hexylidenebis-, 1,1':3',1"-Tercyclohexane, Cyclohexane, 1,1',1"-(1-ethanyl-2-ylidene)tris-.,

[0234] Hydrocarbon yield calculations were based on the following equations:

[0235] [Math 1]

[0236] Where Area x represents the surface area of ​​the hydrocarbon product "x" in the GC-FID chromatogram, Mw x is the molar mass of the hydrocarbon product "x" and

[0237] Response factor xis the effective carbon number (ECN) response factor of hydrocarbon product "x". The "maximum theoretical yield (% by mass)" of hydrocarbons obtainable from lignin oil after the hydrodeoxygenation process was determined by considering the carbon, hydrogen, and oxygen content of the oil as determined by elemental analysis; it allows us to know the maximum theoretical yield of hydrocarbons, i.e., compounds having at least 3 carbon atoms; it does not take into account other by-products, in particular water and methane. The calculation of the maximum theoretical yield of hydrocarbons from lignin oil involved certain assumptions made for the sake of simplicity. First, it was assumed that the total composition of the lignin oil consisted of lignin monomers, propyl guaiacol and propyl syringol. NMR 1 H- 13HSQC allowed the proportions of propyl guaiacol and propyl syringol in lignin oil to be determined, which were then used to establish the empirical formula of lignin oil. The calculations are based on the following reaction scheme:

[0238] C x H y O z + aH2- > C9H18 + bCH4+ cH2O

[0239] Empirical formula of lignin oil: C₆H₁₅O₁₃O₆ Molecular weight = 204.89 g / mol

[0240] Maximum theoretical yield (C9H 18 ) = 61.55%

[0241] The table below summarizes the results of these analyses. The concentrations are expressed relative to the total mass of hydrocarbons obtained (without taking into account the by-products water and methane, i.e. relative to the maximum theoretical yield).

[0242] [Table 5]

[0243] Other lines<C8, autre C9-C16, et autre > C16 represents detected but unidentified molecules. The estimated carbon number is based on the retention time of the molecules in GC. [Table 6]

[0244] * The overall yield corresponds to the mass quantity of the hydrocarbon mixture obtained (without the dodecane) divided by the mass of lignin oil introduced weighted by the maximum theoretical yield, as defined above.

[0245] These results demonstrate that a temperature of 300 °C or 320 °C yields a better C9-C16 compound yield than higher temperatures, with an overall higher yield as well. This is surprising given that prior art processes generally operate at temperatures of at least 350 °C to properly deoxygenate lignin oil, especially in a single step.

[0246] Furthermore, the average number of carbon atoms per molecule of the hydrodeoxygenated lignin oil was calculated for test 2.1 and is estimated at 10.5 carbon atoms. For this purpose, compounds "Other < C8" were considered C7, compounds "Other C9-C16" were considered C16, compounds "Other > C16" were considered C25, and undetected compounds were disregarded.

[0247] This result shows that the process according to the invention not only deoxygenates the lignin oil, but also reduces its average number of carbon atoms per molecule, thereby increasing the yield of usable carbon for jet fuel. This result is all the more surprising given that the hydrodeoxygenation is carried out in a single step. Example 3: Hydrodeoxygenation of RCF lignin oil by a process according to the invention – effect of the nature of the catalyst on the distribution of compounds according to their carbon number. The RCF lignin oil used in this example is identical to that used in Example 2, and the hydrodeoxygenation protocol is also identical.

[0248] The conditions for the hydrodeoxygenation step in this example are as follows: [Table 7]

[0249] The distribution of compounds according to their carbon number of the products obtained was determined by the same method as that detailed in example 2.

[0250] The table below summarizes the results of these analyses. The concentrations are expressed relative to the total mass of hydrocarbons obtained (excluding water and methane by-products). Each catalyst was tested twice (reference XXX-R1 and XXX-R2).

[0251] [Table 8]

[0252]

[0253] The table below shows in particular the mass contents of fractions < C8, C9-C16 and > C16 of the hydrocarbon mixtures obtained (two tests by catalysts were carried out, named R1 and R2).

[0254] [Table 9]

[0255] * The overall yield corresponds to the mass quantity of the hydrocarbon mixture obtained (without the dodecane) divided by the mass of lignin oil introduced weighted by the maximum theoretical yield, as defined above.

[0256] These results show that the three catalysts are capable of deoxygenating lignin oil obtained by reductive catalytic fractionation, providing a product comprising a very high content of C9-C16 compounds.

[0257] Example 4: Hydrodeoxygenation of RCF lignin oil by a process according to the invention - effect of the nature of the catalyst in the hydrodeoxygenation step on the aromatic compound content

[0258] The RCF lignin oil used in this example is identical to that used in Example 2, and the hydrodeoxygenation protocol is also identical.

[0259] The conditions for the hydrodeoxygenation step in this example are as follows: [Table 10]

[0260] The aromatic and naphthenic compound content of the products obtained was determined using the same method as described in Example 2. The table below summarizes the results of these analyses (two tests per catalyst were performed). The concentrations are expressed relative to the total mass of hydrocarbons obtained (excluding the by-products water and methane).

[0261] [Table 11]

[0262] These results show that all catalysts allow for the production of a mixture of aromatic and naphthenic compounds, with a significant proportion of naphthenic compounds, and that the choice of catalyst allows for adjusting the quantity of aromatics in the product.

[0263] Example 5: Hydrodeoxygenation of RCF lignin oil by a process according to the invention - effect of the dilution rate

[0264] The RCF lignin oil used in this example is identical to that used in Example 2, and the hydrodeoxygenation protocol is also identical.

[0265] The conditions for the hydrodeoxygenation step in this example are as follows: [Table 12]

[0266] The content of aromatic and naphthenic compounds in the products obtained was determined by the same method as that described in Example 2.

[0267] The table below shows in particular the mass contents of fractions < C8, C9-C16 and > C16 of the hydrocarbon mixtures obtained (two tests by catalysts were carried out), as well as the oxygen content of the resulting hydrocarbon mixture.

[0268] [Table 13]

[0269] * The overall yield corresponds to the mass quantity of the hydrocarbon mixture obtained (without the dodecane) divided by the mass of lignin oil introduced, weighted by the maximum theoretical yield, as defined above.

[0270] These results show that diluting lignin oil has a positive impact on the hydrodeoxygenation yield. Dilution also helps to limit exothermicity, which is particularly important when the HDO reaction is carried out in a single step.

[0271] Example 6: Hydrodeoxygenation of RCF lignin oil by a process according to the invention - comparison between crude RCF lignin oil and purified RCF lignin oil

[0272] The same experiments (under the same conditions) as those described in Example 3 were performed on crude RCF lignin oil, i.e., oil obtained before the liquid-liquid extraction step. The crude RCF lignin oil was obtained by the same process as that used to obtain the refined RCF lignin oil of Example 2, except that this process does not include the liquid-liquid extraction step described on p. 18, 1.20-29 of WO 2022 / 090364. For analysis, the crude RCF lignin oil was separated into refined RCF lignin oil and a water-soluble fraction. The mass percentage of refined RCF lignin oil in the crude RCF lignin oil is approximately 66% (± 5%), and the percentage of the soluble fraction is 34% by mass (± 5%). The composition of the lignin oil fraction, which reflects the portion of the composition of crude lignin oil, is described below.

[0273] [Table 14] Composition of the refined oil fraction

[0274] The table below shows the total hydrocarbon yield, mass contents of < C8, C9-C16 and > C16 fractions, and mass contents of aromatic and naphthenic compounds of hydrocarbon mixtures obtained from crude lignin oil (two catalyst tests were carried out).

[0275] [Table 15]

[0276] * The overall yield corresponds to the mass quantity of the hydrocarbon mixture obtained (without the dodecane) divided by the mass of lignin oil introduced, weighted by the maximum theoretical yield of the lignin oil introduced, as defined above.

[0277] The sum of aromatic and naphthenic compounds is less than 100% because there are compounds that are detected and whose carbon number is measured, but which are not identified and therefore cannot be classified as aromatic or naphthenic.

[0278] These results show that the process according to the invention can also be implemented on crude RCF lignin oil. The overall yield is better than when starting with refined RCF lignin oil, and this results in a more efficient overall process since it eliminates the need for a purification step on the crude RCF lignin oil to remove sugars.

[0279] Example 7: Oxygen content in hydrodeoxygenated hydrocarbon mixtures

[0280] The oxygen content of hydrocarbon mixtures obtained after hydrodeoxygenation of RCF lignin oil, according to some of the tests in the examples above, was determined by elemental analysis, as described above. This method is based on ASTM 5622 of May 2017, and calibration was performed with BBOT (2,5-Bis(5-tert-butyl-benzoxazol-2-yl)thiophene).

[0281] [Table 16]

[0282] *Expressed relative to the total mass of the hydrocarbon mixture (including diluent)

[0283] These results show that the lignin oil was almost completely deoxygenated in each test (the value < 0.4 is the detection limit of the method used), regardless of the catalyst used (tests 3.1, 3.2 and 3.3), the dilution ratio (3.1, 5.2 and 5.3) or the purity of the lignin oil (crude or refined, tests 3.1 and 6.1). Example 8: Hydrodeoxygenation of lignin oil by a process according to the invention

[0284] - effect of the nature of the oil

[0285] The lignin oils used in this example are identical to those described in Example 1, and the hydrodeoxygenation protocol is identical to that of Example 2.

[0286] The conditions for the hydrodeoxygenation step in this example are as follows: [Table 17]

[0287] The table below shows the total hydrocarbon yield and mass contents of < C8, C9-C16 and > C16 fractions of hydrocarbon mixtures obtained from RCF, ECCL and Organosolv lignin oils (one ECCL oil and two Organosolv oils with different properties, described in Example 1, were tested).

[0288] [Table 18]

[0289] * The overall yield corresponds to the mass of the hydrocarbon mixture obtained (excluding dodecane) divided by the mass of lignin oil introduced, weighted by the maximum theoretical yield, as defined above. These results show that the properties of the lignin oil, which depend in particular on its manufacturing process (RCF or non-RCF), affect the HDO yield. In particular, using an oil produced by RCF, which contains a high proportion of monomers and dimers, results in a higher overall yield, and a higher yield of the C9-C16 fraction, than oils produced by the ECCL and Organosolv processes.

Claims

DEMANDS 1. Process for preparing a mixture of hydrocarbons, comprising a step of hydrodeoxygenation of a mixture to be treated, the mixture to be treated comprising a lignin oil and a diluent, the mass content of the lignin oil being between 0.5% and 70% by mass, relative to the total mass of the mixture to be treated, and the lignin oil comprising, relative to the total mass of the lignin oil, from 9% to 80% by mass of monomeric phenolic compounds comprising between 8 and 12 carbon atoms.

2. A process according to claim 1, wherein the hydrodeoxygenation step is carried out in the presence of a catalyst comprising nickel, cobalt, molybdenum, tungsten or mixtures thereof, preferably comprising oxides, sulfides or phosphides of nickel, cobalt, molybdenum, tungsten or mixtures thereof, preferably supported on a support having a specific surface area of ​​at least 75 m² 2 / g, and preferably being selected from silica, alumina, titanium oxide, zirconium oxide, carbon, cerium oxide, silicon carbide, silica-alumina, silica-alumina-titanium, phosphated alumina or silica-alumina-phosphate, sulfated zirconia, tungsten zirconia, a zeolite, or mixtures thereof.

3. A process according to claim 1 or 2, wherein the hydrodeoxygenation step is carried out under a partial pressure of dihydrogen greater than or equal to 1.10 5 Pa, preferably greater than or equal to 20.10 5 Pa.

4. A process according to any one of the preceding claims, wherein the hydrodeoxygenation step is carried out in a single step, preferably in a single reactor.

5. A process according to any one of the preceding claims, wherein the lignin oil comprises at least one mixture of compounds of the following formula (I): in which each and R2 is independently chosen from -O-CH3 and H, and each R3 is independently chosen from H, a methyl, an ethyl, a propyl, a propenyl, a 1-alkoxypropyl, a 2-hydroxyethyl and a 3-hydroxypropyl.

6. A process according to any one of the preceding claims, wherein the lignin oil comprises at least two, preferably at least three compounds of formula (I), selected from the following compounds (la), (lb), (lc), (ld), (le), (lf), (lg) and (lh):

7. A process according to any one of the preceding claims, wherein the lignin oil is a lignin oil obtained by a catalytic reduction fractionation process of a lignocellulosic biomass.

8. A process according to claim 7, wherein the lignin oil contains oxygen, and the mass of oxygen atoms in carboxylic and carbonyl form in the lignin oil is less than or equal to 20% of the total mass of oxygen atoms present in the lignin oil, preferably less than or equal to 10%, preferably less than or equal to 5%, and even more preferably less than or equal to 2%.

9. A process according to claim 7 or 8, wherein the lignin oil has: - a viscosity at 25 °C less than or equal to 25 Pa.s and / or . - an average molecular mass between 200 and 950 g / mol, preferably between 350 and 830 g / mol, and / or - an average number of carbon atoms between 20 and 60, preferably between 25 and 50, preferably between 30 and 45, preferably between 35 and 40.

10. A process according to any one of claims 7 to 9, wherein the lignin oil comprises, relative to the total mass of the lignin oil, 13% to 50% by mass, preferably 25% to 40% by mass of monomeric phenolic compounds, preferably monomeric phenolic compounds comprising between 8 and 12 carbon atoms.

11. A process according to any one of claims 7 to 10, wherein the lignin oil comprises from 0.4% to 25% by mass, preferably from 1% to 20% by mass, preferably from 2% to 18% by mass, from 5% to 18% by mass, preferably from 8% to 15% by mass of phenolic dimers, relative to the total mass of the lignin oil.

12. A process according to any one of the preceding claims, further comprising a step of catalytic reduction fractionation of a lignocellulosic biomass to obtain lignin oil.

13. A process according to any one of the preceding claims, further comprising a step of fractionating the hydrocarbon mixture, to produce in particular a jet fuel.

14. Hydrocarbon mixture obtained by the process according to any one of claims 1 to 13, comprising from 50% to 95% by mass of C9-C16 compounds relative to the total mass of the hydrocarbon mixture and / or having an average number of carbon atoms between 7 and 18, preferably between 8 and 15, preferably between 9 and 12.

15. Hydrocarbon mixture according to claim 14, comprising less than 5% by mass, preferably less than 2% by mass, preferably less than 0.5% by mass of oxygen atoms relative to the total mass of the hydrocarbon mixture.

16. Jet fuel obtained by the process according to claim 13.

17. Use of jet fuel according to claim 16, (i) in a mixture with jet fuel resulting from the distillation and hydrotreating of petroleum, or (ii) in a mixture with a synthetic jet fuel, to power at least one aircraft engine.

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