Two-stage hydrotreating and hydroisomerizing process for vegetable oil using at least one hydrotreating catalyst based on metals from groups VIB and VIII.

Abstract

The present invention describes a two-stage process for treating a feedstock from a renewable source, employing in a hydrotreating stage a specific hydrodeoxygenation catalyst comprising at least one metal from group VIII, in combination with at least one metal from group VIB of the periodic table, the atomic ratio between the elements of group VIB and VIII being between 0.02 mol / mol and 0.2 mol / mol, at least one organic additive and an oxide support comprising at least alumina followed by a gas / liquid separation stage of the effluent from the hydrotreating and then a hydroconversion stage, to produce at least one diesel fraction.

Description

Title of the invention: Two-step hydrotreating and hydroisomerizing process for vegetable oil using at least one hydrotreating catalyst based on metals from groups VIB and VIII. Scope of the invention

[0001] The search for new renewable energy sources for fuel production is a major challenge in order to both meet fuel demand and take into account environmental concerns and the decarbonisation of the road and air transport sector.

[0002] As such, the use of feedstocks from renewable sources in fuels has seen a significant resurgence of interest in recent years. Examples of these feedstocks include vegetable oils such as rapeseed or soybean oil, animal fats, used cooking oils, and mixtures of such feedstocks. These feedstocks contain chemical structures such as triglycerides, esters, or fatty acids. The fatty acid chains consist of a hydrocarbon structure with variable chain lengths and generally comprise 16 to 18 carbon atoms. Other types of feedstocks containing fatty acids include tall oil from the paper industry and fats derived from cover crops such as camelina and carinata oils.

[0003] One possible route is the catalytic transformation of these feedstocks from renewable sources by hydrotreating (in the presence of hydrogen) into deoxygenated paraffinic fuel. Numerous metallic or sulfide catalysts are known to be active for this type of reaction. Depending on the length of the hydrocarbon chains, the linear paraffins obtained are compatible in terms of boiling points with the hydrocarbons present in fossil diesel and kerosene base fuels.

[0004] These hydrotreating processes for feedstock from renewable sources are already well known and are described in numerous patents. Examples include patents: US 4,992,605, US 5,705,722, EP 1,681,337 and EP 1,741,768.

[0005] Transition metal sulfide-based catalysts enable the production of linear paraffins by transforming oxygenated compounds via two reaction pathways:

[0006] - hydrodeoxygenation (HDO) leading to the formation of water by consumption of hydrogen and the formation of hydrocarbons with a carbon number (Cn) equal to that of the initial fatty acid chains,

[0007] - decarboxylation / decarbonylation (DCO) leading to the formation of oxides of carbon (carbon monoxide and carbon dioxide: CO and CO2) and to the formation of hydrocarbons with one less carbon (Cn-i) compared to the initial fatty acid chains.

[0008] This transformation also leads to the formation of by-products such as propane (from the glyceric structure of fats) and methane (by methanation reaction of carbon oxides under hydrotreating conditions).

[0009] The liquid effluent from these hydrotreating processes, after gas separation, consists essentially of n-paraffins and is substantially free of sulfur, nitrogen, and oxygen impurities. This effluent typically has a sulfur content between 1 and 20 ppm wt., a nitrogen content generally between 0.2 and 30 ppm wt., and an oxygen content generally less than 2000 ppm wt. The paraffins typically have a carbon atom number between 9 and 25, which is mainly dependent on the fatty acid chain distribution of the renewable feedstock to be hydrotreated.

[0010] However, this liquid effluent cannot generally be incorporated as is into the kerosene or diesel pool because it does not directly meet all fuel specifications, for example, due to insufficient cold-weather properties and / or excessively high boiling points. Indeed, the linear paraffins present lead to high pour points and therefore to freezing phenomena for low-temperature applications. For example, eicosane (a linear paraffin with 20 carbon atoms, C2OH) has a boiling point of 340°C and a melting point of 37°C. The boiling point of eicosane is thus compatible with incorporation into a diesel pool, but its melting point can generate freezing problems and limit its use. By way of illustration, the maximum filter plugging point for winter diesel is -15°C according to French regulations (EN590 standard).Furthermore, the boiling point of eicosane makes it unsuitable for use in the kerosene pool, for which the final temperature of the D86 distillation curve must be less than 300°C (ASTM D1655 standard).

[0011] Depending on the type of fuel targeted (kerosene or diesel) and the fuel specifications, it may be necessary to carry out an additional hydroconversion step (hydroisomerization and / or hydrocracking reactions) to transform the linear paraffins in the hydrotreated liquid effluent. Hydroisomerization allows the conversion of a linear paraffin into a branched paraffin while conserving the number of carbon atoms in the molecule. This improves the cold properties of the effluent because branched paraffins exhibit better cold properties and a lower boiling point than corresponding linear paraffins with the same number of carbon atoms. For example, nonadecane has a melting point of 32°C. While one of its monobranch isomers, 7-methyloctadecane, has a melting point of -16°C, hydrocracking allows the conversion of linear paraffin into linear or branched paraffins of lower molecular weights. This enables the distillation curve of the effluent to be adjusted as needed to make it compatible with the kerosene pool, which has more stringent cold-weather property and maximum boiling point specifications. For example, hydrocracking one molecule of eicosane can lead to the production of two molecules of 2-methylnonane. The boiling point of 2-methylnonane is 167°C, which is compatible with its incorporation into the kerosene pool in terms of boiling point. The hydroconversion step is carried out on a bifunctional catalyst exhibiting both a hydro / dehydrogenating function and a Brønsted acid function. The operating conditions can be adapted to favor hydroisomerization or hydrocracking reactions as required. In all cases, it is desirable to minimize the production of excessively light cracking products that cannot be incorporated into the kerosene and diesel fractions, in order to maximize their yield.

[0012] The appropriate choice of acidic phase promotes the isomerization of long linear paraffins and minimizes cracking. Thus, the shape selectivity of medium-pore (10 MR) or large-pore (12 MR) zeolites makes their use particularly suitable for obtaining catalysts selective for isomerization and hydroconversion. Other acidic phases such as halogenated aluminas (particularly chlorinated or fluorinated), phosphorus aluminas, silica-aluminas, or silicified aluminas can also be used.

[0013] However, it is well known that factors other than the acid phase have an impact on the activity and selectivity of a bifunctional catalyst. Hydroisomerization and hydrocracking of normal paraffins have thus been the subject of numerous academic studies since the original work of Weisz (Weisz P, Adv catal 1962, 13, 137) or Coonradt and Garwood (HL Coonradt, WE Garwood Ind. Eng. Chem. Process Des. Dev., 3 (1) (1964), pp. 38-45).

[0014] The most commonly accepted mechanism first involves the n-paraffin being dehydrogenated to n-olefin at a hydro-dehydrogenating site and then, after diffusion to a Brønsted acid site, being protonated to a carbenium ion. After structural rearrangement and / or [3-cleavage], the carbenium ions desorb from the acid phase as olefins after deprotonation. Then, after diffusion to a hydro-dehydrogenating site, the olefins are hydrogenated to form the final reaction products. It is therefore necessary to have a hydro / dehydrogenating function that is sufficiently active with respect to the acid function in order to, on the one hand, rapidly supply the acid phase with olefins and, on the other hand, to rapidly hydrogenate the olefinic intermediates after their reaction with the acid phase. This allows The aim is twofold: firstly, to maximize catalyst activity, and secondly, to maximize the production of isomerized paraffins while limiting overcracking to light hydrocarbons. The use of a sufficiently active hydrogenating function is also desirable to limit the deactivation of the bifunctional catalyst by coking during the hydroconversion of n-paraffins (Alvarez et al., Journal of Catalysis, 162, 2, 179-189) under a range of defined operating conditions.

[0015] Noble metals (Pt, Pd) or transition metals of group VIB (Mo, W) combined with transition metals of group VIII (Ni, Co) can act as hydro / dehydrogenating functional groups for the catalyst. The noble metals are used in their reduced form, while the transition metals of groups VIB and VIII are used in their sulfide form.

[0016] The choice of the type of hydro / dehydrogenating function, whether a noble metal or a transition metal sulfide, depends on various criteria, including economic factors (the price of noble metals is significantly higher than that of transition metals in groups VIB and VIII) and factors related to the nature of the feedstock to be converted (impact of the presence of contaminants). Thus, the hydro / dehydrogenating activity of noble metals is higher than that of transition metal sulfides when the partial pressure of hydrogen sulfide (H2S) in the reaction medium is low or even zero.

[0017] US patent 8809610 (SHELL) claims a process for the production of paraffinic hydrocarbons from a feed containing triglycerides, diglycerides, monoglycerides, and / or fatty acids. The process comprises (a) a hydrodeoxygenation step in the presence of hydrogen and a catalyst to obtain an effluent comprising water and paraffins, (b) a separation step of the effluent from (a) to obtain a liquid effluent rich in paraffins, and (c) a hydroisomerization step of said paraffin-rich effluent in the presence of hydrogen and a catalyst comprising nickel sulfide and tungsten sulfide and / or molybdenum sulfide as hydrogenating phases and a support comprising silica-alumina and / or a zeolite. It is taught that the use of sulfide phases instead of noble metals as hydrogenating phases makes it possible not to have to completely remove impurities from the effluent from step (a).

[0018] US patent 8039682 describes a process for producing kerosene from a renewable feedstock, comprising a hydrotreating, isomerization, and selective hydrocracking step in the presence of a multifunctional catalyst or a series of catalysts, a gas / liquid separation step of the resulting effluent followed by a fractionation step to produce a jet effluent, naphtha, and a residual effluent heavier than the jet, and then recycling this residual effluent back into the reaction zone with a recycle ratio relative to the fresh feedstock of between 0.1 and 8. The deoxygenation and hydrogenation function of the catalyst or series of The catalysts that can be used in the process according to the invention can be provided by a noble metal such as platinum, palladium, rhodium, and ruthenium, or by sulfide metals such as a sulfide-containing NiMo or NiW active phase. The acid function required for the isomerization and / or selective hydrocracking reactions can be provided by a zeolite such as, for example, 10MR and 12MR zeolites, such as structural zeolites BEA, MOR, MFI, or FAU, or by amorphous alumina silica. The patent cites numerous examples of catalysts that can be used in the process according to the invention: a Pt-based catalyst dispersed on a support comprising a Y zeolite (FAU), and a catalyst comprising Pt and Pd on a support comprising a Y zeolite and amorphous alumina silica.In another embodiment, a catalyst comprising Pt and / or Pd on a zeolite Y, ZSM-5 (MFI), amorphous alumina silica, MOR, SAPO-11, and / or SM3 can be used to catalyze all types of reactions. In yet another embodiment, a catalyst comprising a sulfide-containing NiMo phase on a zeolite Y, ZSM-5, amorphous alumina silica, MOR, SAPO-11, and / or SM3 can also be used. A catalyst series can also consist of a sequence of sulfide-containing NiMo supported on amorphous alumina silica followed by a Pt-based catalyst supported on amorphous alumina silica. Numerous other catalysts for deoxygenation, isomerization, and selective hydrocracking are also mentioned.For example, a long list of hydrocracking / isomerization catalysts is cited and includes a Group VIII metal such as Pt and / or Pd, and a support which may be amorphous or crystalline, said support being able to include aluminas, amorphous alumina silica, and ferrierite-type zeolites, ALPO-31, SAPO-II, SAPO-31, SAPO-37, SAPO-41, SM-3, MgAPSO-31, FU-9, NU-IO, NU-23, ZSM-12, ZSM-22, ZSM-23, ZSM-35, ZSM-48, ZSM-50, ZSM-57, MeAPO-II, MeAPO-31, MeAPO-41, MeAPSO-11, MeAPSO-31, MeAPSO-41, MeAPSO-46, ELAPO-II, ELAPO-31, ELAPO-41, ELAPSO-II, ELAPSO-31, ELAPSO-41. This patent also demonstrates that it is possible to carry out the hydroisomerization and hydrocracking steps without prior removal of the water and carbon oxides generated during the hydrotreatment step. The patent example does indeed describe the sequence of two catalysts without specifying their nature or the presence of zeolite.

[0019] US patent application 2022 / 0127537 discloses a hydrotreating process for a renewable feedstock. The process comprises a hydrotreating step of the feedstock in the presence of hydrogen and a hydrotreating catalyst to deoxygenate the feedstock and thus produce a hydrotreated effluent. The process also comprises a hydroisomerization step, in the presence of hydrogen and a hydroisomerization catalyst, of an effluent derived from the hydrotreated effluent to obtain a hydroisomerized effluent. In the case of a two-step process, the catalyst The hydroisomerizing agent used may include a Group VIII metal selected from Pt and Pd, alone or in combination, and a support which may be amorphous or crystalline selected from alumina, silica, amorphous alumina, ferrierite, ALPO-31, SAPO-11, SAPO-31, SAPO-37, SAPO-41, SM-3, MgAPSO-31, FU-9, NU-10, NU-23, ZSM-12, ZSM-22, ZSM-23, ZSM-35, ZSM-48, ZSM-50, ZSM-57, MeAPO-11, MeAPO-31, MeAPO-41, MgAPSO-11, MgAPSO-31, MgAPSO-41, MgAPSO-46, ELAPSO-11, ELAPSO-3, EMAPSO-41, ELAPSO-11, ELAPSO-31, ELAPSO-41, laumontite, cancrinite, offretite, stillbite in hydrogen form, mordenite in magnesium or calcium form, and partheite in calcium or magnesium form, alone or in combination.

[0020] Patent application WO23126564 describes a process for producing kerosene comprising a pretreatment step of the renewable feedstock to reduce impurities, a hydrodeoxygenation step of the pretreated feedstock, a gas / liquid separation step of the hydrotreated effluent and then hydroisomerization of the separated liquid effluent in the presence of a hydroisomerization catalyst comprising a noble metal (preferably platinum) and a support comprising a specific 12MR zeolite (preferably ZSM-12) having a pore size of less than 0.7 nm, an acidity between 180 micromol / g and 500 micromol / g measured by the NH3-TPD method in which the acidity is calculated from the amount of NH3 adsorbed at 200 °C and desorbed between 100 °C and 500 °C.The process also optionally includes a step of stabilizing the hydroisomerized effluent and a step of separating the hydroisomerized effluent or the stabilized effluent to recover a C10-C16 kerosene cut and a C5-C9 gasoline cut.

[0021] In attempting to develop a process for treating feedstocks from renewable sources to produce middle distillates, the applicant has shown, surprisingly, that the use in at least one hydrotreating step of said feedstock of a specific hydrodeoxygenation catalyst comprising at least one metal from group VIII, in combination with at least one metal from group VIB of the periodic table, an atomic ratio between the elements of group VIB and VIII of between 0.02 mol / mol and 0.2 mol / mol, at least one organic additive and an oxide support comprising at least alumina followed by a step of separating the gases and liquids from the hydrotreating step and then a hydroisomerization step made it possible to increase the yields in middle distillates and preferably in diesel cut, compared to the implementation of catalysts conventionally used in the prior art in a process operating in two steps.

[0022] An advantage of the present invention is to maximize the biogenic carbon yield of the two-step process.

[0023] In the sense of the present invention, the different embodiments presented can be used alone or in combination with each other, without limitation of combination.

[0024] In the sense of the present invention, the different ranges of operating parameters for a given step, such as pressure ranges and temperature ranges, can be used alone or in combination. For example, in the sense of the present invention, a preferred range of pressure values ​​can be combined with a more preferred range of temperature values.

[0025] In the following text, the groups of chemical elements are given according to the CAS classification (CRC Handbook of Chemistry and Physics, publisher CRC Press, editor-in-chief DR Lide, 81st edition, 2000-2001). For example, group VIII according to the CAS classification corresponds to the metals of columns 8, 9 and 10 according to the new IUP AC classification, and group VIB to the metals of column 6.

[0026] In the following text, the expressions "between ... and ..." and "between ... and ..." are equivalent and mean that the limit values ​​of the interval are included in the range of values ​​described. If this were not the case and the limit values ​​were not included in the range described, such clarification will be provided by the present invention.

[0027] In this description, the expression "greater than..." is understood as strictly greater than, and symbolized by the sign ">", and the expression "less than" as strictly less than, and symbolized by the sign "<". Object of the invention

[0028] More specifically, the present invention relates to a method for processing a feedstock from a renewable source comprising at least: a. a hydrotreating step of said feed in the presence of at least one fixed-bed catalyst, said hydrodeoxygenation catalyst comprising at least one metal of Group VIII, in combination with at least one metal of Group VIB of the periodic table, the atomic ratio between the elements of Group VIB and VIII being between 0.02 mol / mol and 0.2 mol / mol, at least one organic additive and a support comprising at least one oxide, at a temperature between 200 and 450°C, at a pressure between 1 MPa and 10 MPa, at a space-hour velocity between 0.1 h₁ and 10 h₁ and in the presence of a total quantity of hydrogen mixed with the feed such that the hydrogen / feed ratio is between 70 and 1700 Nm³ of hydrogen / m³ of feed,

[0029] b) a step of separating at least a portion of the effluent from step a) into at least a light gaseous fraction, at least a hydrocarbon liquid effluent consisting of n-paraffins, and at least one aqueous liquid effluent,

[0030] c) a hydroconversion step of at least a portion of the hydrocarbon liquid effluent from step b) in the presence of at least one fixed-bed bifunctional hydroconversion catalyst, said catalyst comprising at least one metal from Group VIII and / or Group VIB of the periodic table, taken alone or in mixture, and a support comprising at least one alumina silica and / or one or more zeolites, said hydroconversion step being carried out at a temperature between 250 and 500°C, at a pressure between 1 and 10 MPa, at an hourly spatial velocity between 0.1 and 10 h-1 and in the presence of a total quantity of hydrogen mixed with the feed such that the hydrogen / feed ratio is between 70 and 1500 Nm3 / m3 of feed,

[0031] c) a step of fractionating the effluent from step b) to obtain at least a diesel fraction. Detailed description of the invention Charges

[0032] The present invention is particularly dedicated to the preparation of diesel fuel bases and possibly kerosene fuel bases corresponding to the new environmental standards, from feedstocks from renewable sources.

[0033] The feedstocks from renewable sources used in the process according to the present invention are advantageously selected from oils and fats of vegetable or animal origin, or mixtures of such feedstocks, containing triglycerides and / or free fatty acids and / or esters. The vegetable oils may advantageously be crude or refined, wholly or partially, and derived from the following plants: rapeseed, sunflower, soybean, palm, palm kernel, olive, coconut, jatropha, this list not being exhaustive. Algae or fish oils are also suitable. The animal fats are advantageously selected from lard or fats composed of residues from the food industry or from the catering industry.

[0034] These fillers essentially contain triglyceride-type chemical structures, also known to those skilled in the art as fatty acid triesters, as well as free fatty acids. A fatty acid triester is thus composed of three fatty acid chains. These fatty acid chains, whether in triester form or as free fatty acids, have a number of unsaturations per chain, also called the number of carbon-carbon double bonds per chain, generally between between 0 and 3 but which can be higher, particularly for oils derived from algae which generally have a number of unsaturations per chain of 5 to 6.

[0035] The molecules present in the feeds from renewable sources used in the present invention therefore have a number of unsaturations, expressed per triglyceride molecule, advantageously between 0 and 18. In these feeds, the degree of unsaturation, expressed as the number of unsaturations per hydrocarbon fatty chain, is advantageously between 0 and 6.

[0036] Feedstocks from renewable sources generally also contain various impurities, including heteroatoms such as nitrogen. Nitrogen content in vegetable oils, used cooking oils, and animal fats is generally between approximately 1 ppm and 300 ppm by weight, depending on their nature.

[0037] Other types of fillers containing fatty acids can also be mentioned, such as Tall Oil fillers from the paper industry. Process and catalysts

[0038] Advantageously, the feedstock may undergo a pretreatment or pre-refining step prior to step a) of the process according to the invention in order to remove, by appropriate treatment, contaminants such as metals, alkali compounds (for example, on ion-exchange resins), alkaline earth metals, and phosphorus. Appropriate treatments may, for example, be thermal and / or chemical treatments well known to those skilled in the art.

[0039] According to step a) of the process according to the invention, the feed, optionally pretreated, is brought into contact with at least one fixed-bed hydrotreating catalyst at a temperature between 200 and 450°C, preferably between 220 and 350°C, most preferably between 220 and 320°C, and even more preferably between 220 and 310°C. The pressure is between 1 MPa and 10 MPa, most preferably between 1 MPa and 6 MPa, and even more preferably between 1 MPa and 4 MPa. The hourly spatial velocity, i.e., the feed volume per catalyst volume per hour, is between 0.1 h⁻¹ and 10 h⁻¹. The feed is brought into contact with the catalyst in the presence of hydrogen. The total amount of hydrogen mixed with the feed is such that the hydrogen / feed ratio is between 70 and 1700 Nm3 of hydrogen / m3 of feed and preferably between 150 and 1500 Nm3 of hydrogen / m3 of feed.

[0040] In step a) of the process according to the invention, the hydrodeoxygenation catalyst comprises at least one metal from group VIII, in combination with at least one metal from group VIB of the periodic table, the atomic ratio between the elements of group VIB and VIII being between 0.02 mol / mol and 0.2 mol / mol, at least one organic additive and an oxide support.

[0041] Preferably the support comprises at least one oxide selected from titanium oxide, alumina, silica and zirconia, alone or in mixture. Preferably, said oxide support comprises at least alumina and preferably, said support is made of alumina and preferably comprises and is preferably made of alumina r|, ô or y and preferably made of alumina p, ô or y.

[0042] Said hydrotreating catalyst is advantageously a catalyst comprising at least one metal from group VIII preferably chosen from nickel and cobalt, taken alone or in mixture, preferably in association with at least one metal from group VIB preferably chosen from molybdenum and tungsten, taken alone or in mixture.

[0043] The content of metal oxides of groups VIII and preferably of nickel oxide is advantageously between 0.1 and 10% by weight and preferably between 0.5 and 10% by weight of nickel oxide (NiO) and preferably between 0.7 and 5% by weight of nickel oxide and the content of metal oxides of groups VIB and preferably of molybdenum trioxide is advantageously between and 35% by weight of molybdenum oxide (MoO3), preferably from 5 to 30% by weight, the percentages being expressed as % by weight in relation to the total mass of the catalyst.

[0044] The total content of metal oxides of groups VIB and VIII in the catalyst used in step a) is advantageously between 5 and 45% by weight and preferably between 6 and 35% by weight relative to the total mass of the catalyst.

[0045] According to the invention, said catalyst comprises at least one organic additive. Preferably, said catalyst comprises at least one organic additive selected from organic compounds containing oxygen, organic compounds containing nitrogen, organic compounds containing oxygen and nitrogen, and organic compounds containing sulfur, alone or in mixture.

[0046] The oxygen-containing organic compound may be one or more compounds selected from among those having one or more chemical functions selected from among a carboxyl group, alcohol, ether, aldehyde, ketone, ester, or carbonate, or compounds including a furan ring, or sugars. An oxygen-containing organic compound is understood here to be a compound not containing any other heteroatom.As an example, the oxygen-containing organic compound may be one or more of the following selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol (with a molecular weight between 200 and 1500 g / mol), propylene glycol, 2-butoxyethanol, 2-(2-butoxyethoxy)ethanol, 2-(2-methoxyethoxy)ethanol, triethylene glycol dimethyl ether, glycerol, acetophenone, 2,4-pentanedione, pentanone, acetic acid, oxalic acid, maleic acid, malic acid, malonic acid, oxalic acid, gluconic acid, tartaric acid, citric acid, . γ-Ketovaleric acid, a C1-C4 dialkyl succinate and more particularly dimethyl succinate, methyl acetoacetate, ethyl acetoacetate, 2-methoxyethyl 3-oxobutanoate, 2-methacryloyloxyethyl 3-oxobutanoate, dibenzofuran, a crown ether, orthophthalic acid, glucose, fructose, sucrose, sorbitol, xylitol, γ-valerolactone, 2-acetylbutyrolactone, propylene carbonate, 2-furaldehyde (also known as furfural), 5-hydroxymethylfurfural (also known as 5-(hydroxymethyl)-2-furaldehyde or 5-HMF), 2-acetylfuran, 5-methyl-2-furaldehyde, 2-furoate methyl, furfuryl alcohol (also known as furfuranol), furfuryl acetate, ascorbic acid, butyl lactate, ethyl lactate, butyl butyryllactate, ethyl 3-hydroxybutanoate, ethyl 3-ethoxypropanoate, methyl 3-methoxypropanoate, 2-ethoxyethyl acetate, 2-butoxyethyl acetate,2-Hydroxyethyl acrylate, 2-Hydroxyethyl methacrylate, 1,5-Pentanediol, 3-Methyl-1,5-Pentanediol, 1,5-Hexanediol, 3-Ethyl-1,5-Pentanediol, 2,4-Diethyl-1,5-Pentanediol, 5-Methyl-2(3H)-Furanone, butyl glycolate, ethyl 4-oxo-pentanoate, diethyl maleate, dimethyl maleate, dimethyl fumarate, diethyl fumarate, dimethyl adipate, dimethyl 3-oxoglutarate, dimethyl tartrate, diethyl tartrate, diisopropyl tartrate, di-tert-butyl tartrate, dimethyl malate, diethyl malate, Diisopropyl malate and dibutyl malate.

[0047] Preferably, the organic compound contains oxygen; preferably, it is selected from γ-valerolactone, 2-acetylbutyrolactone, triethylene glycol, diethylene glycol, ethylene glycol, ethylenediaminetetraacetic acid (EDTA), maleic acid, malonic acid, citric acid, acetic acid, oxalic acid, gluconic acid, glucose, fructose, sucrose, sorbitol, xylitol, γ-ketovaleric acid, a C1-C4 dialkyl succinate, and more particularly dimethyl succinate, dimethylformamide, γ-methyl-2-pyrrolidinone, propylene carbonate, 2-methoxyethyl 3-oxobutanoate, bicine, tricine, 2-furaldehyde (also known as furfural), the 5-Hydroxymethylfurfural (also known as 5-(hydroxymethyl)-2-furaldehyde or 5-HMF), 2-Acetylfuran, 5-Methyl-2-furaldehyde, ascorbic acid, butyl lactate, ethyl lactate, butyl butyryllactate, ethyl 3-Hydroxybutanoate,ethyl 3-ethoxypropanoate, 2-ethoxyethyl acetate, 2-butoxyethyl acetate, 2-hydroxyethyl acrylate, l-vinyl-2-pyrrolidinone, l,3-dimethyl-2-imidazolidinone, 1,5-pentanediol, lal-(2-hydroxyethyl)-2-pyrrolidinone, l-(2-hydroxyethyl)-2,5-pyrrolidinedione, 5-methyl-2(3H)-furanone, l-methyl-2-piperidinone, 4-aminobutanoic acid, butyl glycolate, ethyl 2-mercaptopropanoate, ethyl 4-oxopentanoate, diethyl maleate, dimethyl maleate, fumarate, dimethyl, diethyl fumarate, dimethyl adipate and dimethyl 3-oxoglutarate.

[0048] Preferably, the organic compound is chosen from levulinic acid, citric acid, triethylene glycol, diethylene glycol, ethylene glycol, a mixture of acetic acid and dimethyl succinate.

[0049] The nitrogen-containing organic compound may be one or more compounds selected from among those having one or more chemical functions selected from an amine or nitrile group. Here, a nitrogen-containing organic compound is understood to mean a compound not containing any other heteroatom. By way of example, the nitrogen-containing organic compound may be one or more compounds selected from the group consisting of ethylenediamine, diethylenetriamine, hexamethylenediamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, acetonitrile, octylamine, guanidine, or a carbazole.

[0050] The organic compound containing oxygen and nitrogen may be one or more of the following compounds having one or more chemical functions selected from among a carboxylic acid, alcohol, ether, aldehyde, ketone, ester, carbonate, amine, nitrile, imide, amide, urea, or oxime function. An organic compound containing oxygen and nitrogen is understood here to be a compound not containing any other heteroatom.As an example, the organic compound containing oxygen and nitrogen may be one or more chosen from the group consisting of 1,2-cyclohexanediaminetetraacetic acid, monoethanolamine (MEA), l-methyl-2-pyrrolidinone, dimethylformamide, ethylenediaminetetraacetic acid (EDTA), alanine, glycine, nitrilotriacetic acid (NTA), N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid (HEDTA), diethylenetriaminepentaacetic acid (DTPA), tetramethylurea, glutamic acid, dimethylglyoxime, bicine, tricine, 2-methoxyethyl cyanoacetate, l-ethyl-2-pyrrolidinone, 1-vinyl-2-pyrrolidinone, the l,3-dimethyl-2-imidazolidinone, l-(2-hydroxyethyl)-2-pyrrolidinone, l-(2-hydroxyethyl)-2,5-pyrrolidinedione, l-methyl-2-piperidinone, l-acetyl-2-azepanone, l-vinyl-2-azepanone and 4-aminobutanoic acid.

[0051] The sulfur-containing organic compound may be one or more of the compounds having one or more chemical functions selected from a thiol, thioether, sulfone, or sulfoxide function. By way of example, the sulfur-containing organic compound may be one or more of the following selected from the group consisting of thioglycolic acid, 2,2'-thiodiethanol, 2-hydroxy-4-methylthiobutanoic acid, a sulfonated derivative of a benzothiophene or a sulfoxidized derivative of a benzothiophene, ethyl 2-mercaptopropanoate, methyl 3-(methylthio)propanoate, and ethyl 3-(methylthio)propanoate.

[0052] When present, the total content of organic compound(s) containing oxygen and / or nitrogen and / or sulfur present in the catalyst is generally between 1 and 30% by weight, preferably between 1.5 and 25% by weight, and more preferably between 2 and 20% by weight relative to the total weight of the catalyst.

[0053] The metals are advantageously introduced into the oxide support by any method known to those skilled in the art, such as co-mixing, dry impregnation, excess impregnation, or exchange impregnation. The organic compound(s) are introduced by dry or excess impregnation onto the support before, simultaneously with, or after the introduction of the metals.

[0054] During the preparation of the catalyst requiring a drying step, the drying step(s) following the introduction of the organic compound is / are advantageously carried out at a temperature below 200°C so as to retain preferably at least 30%, preferably at least 50%, and most preferably at least 70% of the quantity of at least said organic additive introduced, calculated on the basis of the carbon remaining on the catalyst. The remaining carbon is measured by elemental analysis according to ASTM D5373.

[0055] According to the invention, the molar ratio of metal(ux) of groups VIB and VIII in the catalyst used in step a) is advantageously between 0.02 mol / mol and 0.2 mol / mol, preferably between 0.05 mol / mol and 0.15 mol / mol, and preferably between 0.06 and 0.12 mol / mol.

[0056] The organic compound(s) is / are advantageously introduced into an impregnation solution which, depending on the method of preparation, may be the same solution or a different solution from that containing the precursors of the metals of groups VIB and VIII, in a corresponding quantity:

[0057] - to a molar ratio of the organic compound to the sum of the elements of the group VIB of catalyst precursors ranging from 0.01 to 30 mol / mol, preferably from 0.03 to 15 mol / mol, preferably from 0.05 to 10 mol / mol, and most preferably from 0.1 to 8 mol / mol, calculated on the basis of the components introduced into the impregnation solution(s), and

[0058] - to a molar ratio of the organic compound to the element(s) of group VIII of the catalyst precursor (Ni) of between 0.02 to 300 mol / mol, preferably between 0.1 to 150 mol / mol, preferably between 0.5 and 100 mol / mol and most preferably between 1 and 80 mol / mol, calculated on the basis of the components introduced into the impregnation solution(s).

[0059] When several organic compounds are present, the different molar ratios apply to each of the organic compounds present.

[0060] The hydrotreating catalyst used in step a) of the process according to the invention is to be chosen so as to orient the selectivity of the reaction as much as possible towards the deoxygenation reaction that conserves the number of carbon atoms in the fatty acid chains, i.e., the hydrodeoxygenation (HDO) pathway. This is in order to maximize the recovery of the renewable feedstock into fuel fractions and the yield of hydrocarbons suitable for kerosene and / or diesel distillation, and thus limit carbon loss in the form of carbon oxides and methane. Therefore, it is preferably operated at a relatively low temperature. Maximizing the hydrogenating function also helps to limit polymerization and / or condensation reactions leading to coke formation, which would degrade the stability of the catalytic performance.

[0061] The catalyst used in step a) of the hydrotreating process according to the invention may also advantageously contain a dopant element selected from phosphorus and boron, alone or in a mixture, and preferably phosphorus. This dopant element may be introduced into the matrix or, preferably, deposited on the support. Silicon may also be deposited on the support, alone or with phosphorus and / or boron and / or fluorine.

[0062] The weight content of oxide of said dopant element in relation to the total weight of said catalyst is advantageously less than 20% and preferably less than 10% and is advantageously at least 0.001% and preferably between 0.01 and 8% by weight.

[0063] The metals of the catalysts used in step a) of hydrotreating of the process according to the invention are sulfide metals or metallic phases and preferably sulfide metals.

[0064] It would not depart from the scope of the present invention to use, in step a) of the process according to the invention, simultaneously or successively, a single catalyst or several identical or different catalysts. This step can be carried out industrially in one or more reactors with one or more catalytic beds.

[0065] Said step a) of hydrotreatment allows the hydrodeoxygenation, hydrodeazotation and hydrodesulfurization of said feed.

[0066] In accordance with step b) of the process according to the invention, a separation step is carried out to separate at least part, and preferably all, of the effluent from step a). This step b) separates at least one hydrogen-rich, so-called light gaseous fraction, at least one hydrocarbon liquid effluent consisting of n-paraffins, and at least one aqueous liquid effluent.

[0067] Said light gaseous fraction comprises at least the hydrogen not converted by the reactions carried out in step a), at least the gases with one or more atoms of oxygen resulting from the decomposition of oxygenated compounds in step a) and at least the C4- compounds, i.e., the Cl to C4 compounds preferably having a final boiling point below 20°C. The aim of this step is to separate the gases from the liquids. More specifically, the aim is to recover at least the hydrogen-rich gases, which may also contain compounds such as CO and CO2, at least one liquid hydrocarbon effluent consisting of n-paraffins, and at least one aqueous liquid effluent containing the water produced by the reactions carried out in step a). Said liquid hydrocarbon effluent preferably has a sulfur content of less than 10 ppm w / w and a nitrogen content of less than 2 ppm w / w.

[0068] The hydrocarbon liquid effluent consisting of n-paraffins from said step b) advantageously comprises a content of compounds boiling at a temperature above 370°C strictly above 50%, preferably above 60%, preferably above 70% and most preferably above 90% by weight relative to the total mass of said effluent.

[0069] Step b) of separation can advantageously be implemented by any method known to the person skilled in the art such as, for example, the combination of one or more high and / or low pressure separators operated hot or cold, and / or high pressure and / or low pressure stripping.

[0070] Step b) also allows the separation of at least one aqueous liquid effluent, preferably water. The removal of at least some of the water, and preferably all of it, can be carried out by any methods and techniques known to those skilled in the art. Preferably, the water removal is carried out by settling in a separatory vessel, by drying, by passing through a desiccant, by flash drying, or by a combination of at least two of these techniques. The atomic oxygen content of the hydrocarbon liquid effluent containing the paraffinic hydrocarbons from step b) of the process according to the invention, expressed in parts per million by weight (ppm), is preferably less than 10,000 ppm, most preferably less than 6,000 ppm, most preferably less than 1,000 ppm by weight, and most preferably less than 500 ppm by weight.The atomic oxygen content in ppm weight in said hydrocarbon liquid effluent is measured by the infrared absorption technique such as, for example, the technique described in patent application US2009 / 0018374A1.

[0071] In a preferred embodiment, at least part of the hydrocarbon liquid effluent consisting of n-paraffins from said step a) is recycled to hydrotreating step a), so that the recycle rate, i.e. the mass ratio between the flow of said recycled liquid effluent and the feed flow introduced into hydrotreating step a), is less than or equal to 2, preferably less than or equal to 1.7, preferably less than or equal to 1.5.

[0072] It is known that using a high liquid recycle rate allows for better exothermic control and, in particular, maintains the temperature difference between the outlet and inlet temperatures of each catalytic zone within a range acceptable for industrial operation of the process. Surprisingly, despite the implementation of a low liquid recycle rate, the present invention allows for optimized exothermic control within the different catalytic zones thanks to the combination of said low recycle rate and a high hydrogen flow rate at the inlet of the first bed.

[0073] Furthermore, the use of a low-consumption recycled liquid facilitates the revamping of existing units. Revamping, in Anglo-Saxon terminology, refers to the revision of the design of equipment already in operation in order to increase its production, technical, economic and environmental performance, as well as its reliability.

[0074] According to the invention, the process comprises a hydroconversion step of at least a part and preferably all of the hydrocarbon liquid effluent from step b) of the process in the presence of at least one fixed-bed bifunctional hydroconversion catalyst, said catalyst comprising at least one metal from Group VIII and / or at least one metal from Group VIB of the periodic table taken alone or in mixture and a support comprising at least one silica alumina and / or one or more zeolites, said hydroconversion step being carried out at a temperature between 250 and 500°C, at a pressure between 1 and 10 MPa, at a spatial velocity hourly between 0.1 and 10 h 1 and in the presence of a total quantity of hydrogen mixed with the feed such that the hydrogen / feed ratio is between 70 and 1500 Nm3 / m3 of feed.

[0075] The operating conditions of step c) of hydroconversion are adjusted to promote hydroisomerization and / or hydrocracking reactions. Preferably, step c) of hydroconversion of the process according to the invention operates at a temperature between 250°C and 450°C, and most preferably between 250 and 400°C, at a pressure between 2 MPa and 10 MPa and most preferably between 1 MPa and 9 MPa, at an hourly volumetric rate advantageously between 0.2 and 7 h⁻¹ and most preferably between 0.5 and 5 h⁻¹, at a hydrogen flow rate such that the hydrogen / feed volume ratio is advantageously between 100 and 1000 normal m³ of hydrogen per m³ of feed and most preferably between 150 and 1000 normal m³ of hydrogen per m³ of feed.

[0076] According to the invention, the hydroconversion catalyst is a bifunctional catalyst comprising at least one metal from group VIII and / or at least one metal of group VIB of the periodic classification and a support comprising alumina silica and / or one or more zeolites.

[0077] The metals of group VIII are advantageously chosen from iron, cobalt, nickel, platinum, and palladium, taken alone or in mixture, and preferably from nickel, cobalt, platinum, and palladium.

[0078] The metals of group VIB are chosen from tungsten and molybdenum, taken alone or in mixture.

[0079] If the Group VIII metals are chosen from among the non-noble metals, the following metal combinations are preferred: nickel-molybdenum, cobalt-molybdenum, nickel-tungsten, cobalt-tungsten, and, most preferably, nickel-molybdenum, nickel-tungsten. Combinations of three metals, such as nickel-cobalt-molybdenum or nickel-molybdenum-tungsten, may also be used. The Group VIII and / or Group VIB metals are introduced by any method known to those skilled in the art, for example, by dry impregnation of the substrate with the metal precursor(s) dissolved in a solvent, which may be water. One or more organic compounds may also be added during this impregnation step or in a subsequent impregnation step. These organic compounds may contain oxygen and / or nitrogen and / or sulfur.For example, in the case of the use of oxygenated compounds, one can cite compounds comprising one or more functions chosen from among a carboxylic function, alcohol, ether, ketone, ester or carbonate or even furanic compounds or even sugars.

[0080] The content of the catalyst in non-noble group VIII metal is advantageously between 0.5% and 10% by weight of oxide relative to the total weight of said catalyst, preferably between 1% and 8% by weight of oxide and most preferably between 1.5% and 6% by weight of oxide.

[0081] In the case where the metals of group VIII are chosen from among the noble metals, the content of noble metal of group VIII, and preferably the platinum content, in the catalyst used in step c) is between 0.01% and 4% weight, preferably between 0.05% and 2% weight, relative to the total weight of said catalyst.

[0082] The content of the catalyst in metal of group VIB is advantageously between 1% and 50% by weight of oxide relative to the total weight of said catalyst, preferably between 10% and 40% by weight of oxide, most preferably between 15% and 35% by weight of oxide.

[0083] The catalyst used in step c) may also advantageously comprise further at least one additional metal selected from the group formed by the metals of groups IIIA, IVA and VIIB of the periodic table of elements and preferably chosen from gallium, indium, tin and rhenium. Said additional metal is preferably chosen from indium, tin and rhenium.

[0084] Preferably, the content of at least one additional metal in the catalyst used in step c) is between 0.01% and 2% by weight, preferably between 0.05% and 1% by weight, relative to the total weight of said catalyst.

[0085] In a preferred embodiment, the catalyst comprises at least one metal from group VIII and preferably nickel and at least one metal from group VIB and preferably tungsten, preferably active in their sulfide form.

[0086] In another embodiment, the catalyst comprises at least one Group VIII metal, and preferably a Group VIII noble metal selected from platinum and palladium. Preferably, the Group VIII metal of the catalyst used in step c) is platinum, preferably active in its reduced form.

[0087] The metallic function is advantageously introduced into the catalyst by any method known to those skilled in the art, such as co-mixing, dry impregnation or exchange impregnation.

[0088] In one embodiment, the sulfur content in the hydroconversion catalyst comprising a Group VIII noble metal is such that the ratio of the number of moles of sulfur to the number of moles of at least one Group VIII noble metal is between 0.3 and 3. In one or more embodiments, the presence of sulfur in the catalyst originates from an optional sulfidation step of the hydroisomerization catalyst. In one or more embodiments, the presence of sulfur in the catalyst originates from potentially present impurities, such as, for example, in the alumina binder. In another embodiment, the catalyst does not contain sulfur.

[0089] The catalyst used in step c) of the hydroconversion of the process according to the invention may also advantageously contain a dopant element selected from phosphorus and boron, alone or in a mixture, and preferably phosphorus. This dopant element may be introduced into the matrix or, preferably, deposited on the support. Silicon may also be deposited on the support, alone or with phosphorus and / or boron and / or fluorine.

[0090] The weight content of the oxide of said dopant element is advantageously less than 20% and preferably less than 10% and is advantageously at least 0.001% and preferably between 0.01 and 8% by weight.

[0091] The metals are advantageously introduced into the catalyst by any method known to those skilled in the art, such as co-mixing, dry impregnation, excess impregnation or exchange impregnation.

[0092] Preferably, the hydroconversion catalyst support comprises at least one zeolite selected from 10 MR and / or 12 MR zeolites, preferably selected from structural zeolites of type MTT, MTW, *BEA, MOR, *MRE, MFI, FAU and zeolite IZM-2, and / or a silica-alumina.

[0093] According to one embodiment, the hydroconversion catalyst advantageously comprises at least one zeolite selected from structural type MTT zeolites, preferably selected from ZSM-23, EU-13, alone or in mixtures; structural type MTW zeolites, preferably selected from ZSM-12, TPZ-12, Theta-3, NU-13, CZH-5, taken alone or in mixtures; structural type *BEA zeolites, preferably selected from Beta or Tschemichite alone or in mixtures; structural type MOR zeolites, preferably selected from mordenite or LZ-211, taken alone or in mixtures; structural type MFI zeolites, preferably ZSM-5; structural type *MRE zeolites, preferably ZSM-48; structural type FAU zeolites, preferably... zeolite Y and zeolite IZM-2 and possibly at least one oxide binder.

[0094] Structural codes are defined in the International Zeolite Association (IZA: http: / / www.iza-structure.org / databases / ) classification.

[0095] Zeolite may also be IZM-2, the structural code of which is not known.

[0096] Preferably, the zeolite is chosen from among the zeolites ZSM-12, IZM-2 and ZSM-23, alone or in mixture and preferably among the zeolites ZSM-12 and IZM-2.

[0097] Preferably, the catalyst used in step c) comprises a zeolite content of between 1% and 90% by weight, preferably between 3% and 80% by weight, and more preferably between 4% and 60% by weight, preferably between 4% and 30% by weight and even more preferably between 6% and 30% by weight relative to or total weight of said catalyst.

[0098] Optionally, the catalyst support used in step c) may also include a binder. Preferably, the support includes a binder when it comprises a zeolite. The binder is advantageously selected from silica (SiO2), alumina (Al2O3), clays, titanium dioxide (TiO2), boron dioxide (B2O3), and zirconia (ZrO2), alone or in mixtures. Preferably, the binder is selected from silica and alumina, and even more preferably, the binder is alumina in all its forms known to those skilled in the art, such as, for example, gamma alumina.

[0099] Preferably, the catalyst used in step c) comprises a binder content of between 10% and 99% by weight, relative to or total weight of said catalyst i.e., so as to ensure the complement to 100% by weight of the elements constituting the catalyst used in step e).

[0100] A preferred catalyst for step d) comprises and is preferably made of platinum, and a support comprising and preferably made of an IZM-2 zeolite and an alumina binder. In this case, said catalyst is in reduced form.

[0101] Another preferred catalyst for step d) comprises and is preferably made of nickel and tungsten, and a support comprising and preferably made of an IZM-2 zeolite and an alumina binder. In this case, said catalyst is in sulfide form.

[0102] Another preferred catalyst for step d) comprises and is preferably made of nickel and tungsten, and a support comprising and preferably made of a ZSM-12 zeolite and an alumina binder. In this case, said catalyst is in sulfide form.

[0103] Another preferred catalyst for step d) comprises and is preferably made of platinum, and a support comprising and preferably made of a ZSM-12 zeolite and an alumina binder. In this case, said catalyst is in reduced form.

[0104] According to the invention, the support for the hydroconversion catalyst comprises and is preferably made of silica-alumina.

[0105] A preferred hydroconversion catalyst used in said hydroconversion step c) comprises and preferably consists of at least one noble metal, said noble metal being platinum, and a silica-alumina as an acid support, without any other binder. In this case, said catalyst is in reduced form.

[0106] Another preferred hydroconversion catalyst used in the hydroconversion step (d) comprises and preferably consists of at least tungsten and / or molybdenum and at least nickel and / or cobalt, and preferably nickel and tungsten, and silica-alumina as an acid support, without any other binder. In this case, said catalyst is in sulfide form.

[0107] The silica-alumina support advantageously has a total pore volume of between 0.1 and 1.5 cm³.g', preferably between 0.2 and 0.8 cm³.g' and particularly preferably between 0.3 and 0.6 cm³.g'. The total pore volume is measured by mercury porosimetry according to ASTM D4284 with a wetting angle of 140°, as described in the book Rouquerol F.; Rouquerol J.; Singh K. "Adsorption by Powders & Porous Solids: Principle, methodology and applications", Academy Press, 1999, for example using an Autopore III™ instrument from Micromeritics™.

[0108] The specific surface area of ​​the silica-alumina support is advantageously between 5 and 400 m².g', preferably between 100 and 350 m².g', and more preferably between 200 and 300 m².g'. The specific surface area is determined in the present invention by the BET method according to ASTM D3663, a method described in the same work cited above.

[0109] The silica content in the support is at most 50% by weight relative to the total weight of the support, most often less than or equal to 45% by weight, preferably less than or equal to 40%. Preferably, the silica content in the support is between 10 and 50% wt, preferably between 15 and 40% wt and particularly preferably between 20 and 35% wt relative to the total weight of the support.

[0110] Sources of silicon are well known to those skilled in the art. Examples include silicic acid, silica in powder form or in colloidal form (silica sol), and tetraethyl orthosilicate Si(OEt)4.

[0111] According to another embodiment, the support for the hydroconversion catalyst is a silica-alumina which may also advantageously contain a zeolite. In this case, all sources of zeolites and all associated preparation methods known to those skilled in the art may be incorporated. Preferably, the zeolite is selected from the FAU, BEA, ISV, IWR, IWW, MEI, and UWY groups, and more preferably, the zeolite is selected from the FAU and BEA groups, such as Y and / or beta zeolite, and particularly preferably such as USY and / or beta zeolite. When the zeolite is present, its content is from 0.1 to 50 wt% relative to the total weight of the support, preferably from 0.1 to 10 wt%.

[0112] The support is advantageously in the form of irregular and non-spherical beads, extrudates, pellets or agglomerates whose specific shape may result from a crushing step.

[0113] In a highly preferred embodiment, step c) of hydroconversion is carried out in the presence of a chain of a first catalyst comprising and preferably made up of at least one noble metal, said noble metal being platinum, and a silica-alumina, without any other binder, said first catalyst being in reduced form and a second catalyst comprising and preferably made up of platinum, and a support comprising a ZSM-12 zeolite and an alumina binder, in reduced form.

[0114] In another highly preferred embodiment, the hydroconversion step c) is carried out in the presence of a chain of a first catalyst comprising and preferably made up of at least nickel and tungsten, and a silica-alumina, without any other binder, said first catalyst being in sulfide form and a second catalyst comprising and preferably made up of nickel and tungsten, and a support comprising and preferably made up of a ZSM-12 zeolite and an alumina binder, in sulfide form.

[0115] In accordance with step c) of the process according to the invention, the effluent from step b) undergoes a fractionation step allowing at least one diesel fraction to be recovered.

[0116] Preferably said step c) comprises a gas / liquid separation step followed by a water removal step.

[0117] Said step c) may also advantageously include an atmospheric distillation step and optionally a vacuum distillation step, to obtain at least a middle distillate fraction.

[0118] Said step c) is intended to separate the gases from the liquid, to remove the water and in particular, to recover the hydrogen-rich gases which may also contain light gases such as the Ci-C4 cut and at least one diesel cut, possibly at least one kerosene cut and possibly at least one naphtha cut.

[0119] At least a portion of the middle distillate fraction can advantageously be recycled in step a) of hydrotreating.

[0120] The examples below illustrate the invention without limiting its scope. EXAMPLES

[0121] Examples 1 to 4 describe the preparation of Cl to C4 catalysts.

[0122] Examples 5 to 11 describe the evaluation in hydrotreating and hydroisomerization of a feed from a renewable source implementing a catalyst chain comprising the hydrotreating catalyst Cl with respectively the hydroisomerization catalysts C2 to C6.

[0123] Example 1: preparation of a hydrotreating catalyst (Cl) (not according to the invention)

[0124] Nickel, molybdenum, and phosphorus are added to 100 grams of an alumina (Al) support having a loss on ignition (LOI) of 4.1% by weight, a BET surface area of ​​263 m² / g, a pore volume measured by mercury porosimetry of 0.66 mL / g, and a mean pore diameter of 9.7 nm, defined as the median diameter by volume by mercury porosimetry, and which is in extruded form. The Al support has a water absorption volume of 0.72 mL / g. The impregnation solution is prepared by dissolving at 90°C 29.2 grams of molybdenum oxide (Merck™, purity > 99.5 wt.), 2.4 grams of nickel hydroxycarbonate (Merck™, purity 99.9 wt.), and 11.2 grams of orthophosphoric acid solution (Merck™, 85 wt. in water) in 64.2 mL of distilled water. The molar ratio between the elements of groups VIII and VIB is 0.1 mol / mol.After dry impregnation, the extrudates are left to mature in a water-saturated atmosphere for 24 h at room temperature, then they are dried at 90°C for 2 h, before being calcined in air at 450°C for 4 hours. The calcined catalyst thus obtained is denoted CL. The final composition of the catalyst Cl, expressed as oxides, is as follows: MoO3 = 22 + / - 0.2 (wt.%), NiO = 1.1 + / - 0.1 (wt.%) and P2O5 = 5.2 + / - 0.1 (wt.%).

[0125] Example 2: preparation of a hydrotreating catalyst (C2) (not according to the invention)

[0126] Nickel, molybdenum, and phosphorus are added to the same alumina (Al) support as shown in Example 1. The impregnation solution is prepared by dissolving 31.1 grams of molybdenum oxide (Merck™, purity > 99.5 wt.), 10.1 grams of nickel hydroxycarbonate (Merck™, purity 99.9 wt.), and 11.9 grams of orthophosphoric acid solution (Merck™, 85 wt. in water) at 90°C in 63.9 mL of distilled water. The molar ratio between the elements of Groups VIII and VIB is 0.4 mol / mol. After dry impregnation, the extrudates are left to mature in a water-saturated atmosphere for 24 h at room temperature, then they are dried at 160°C for 1 hour before being dry impregnated again with an aqueous solution containing 26.1 grams of triethylene glycol (TEG, Merck™) so that the TEG / Mo molar ratio is 0.8 and the TEG / Ni molar ratio is 2. A final drying is then applied to the extrudates for one hour under air at 90°C.The resulting additive catalyst is denoted C2. The final composition of catalyst C2, expressed as oxides, is as follows: MoO3 = 22 + / - 0.2 (weight %), NiO = 4.6 + / - 0.1 (weight %) and P2O5 = 5.2 + / - 0.1 (weight %).

[0127] Example 3: preparation of a hydrotreating catalyst (C3) (not according to the invention)

[0128] Nickel, molybdenum, and phosphorus are added to the same alumina Al support as shown in Example 1. The impregnation solution is prepared by dissolving 29.2 grams of molybdenum oxide (Merck™, purity > 99.5 wt.), 0.5 grams of nickel hydroxycarbonate (Merck™, purity 99.9 wt.), and 11.2 grams of orthophosphoric acid solution (Merck™, 85 wt. in water) at 90°C in 65.3 mL of distilled water. The molar ratio between the elements of Groups VIII and VIB is 0.01 mol / mol. After dry impregnation, the extrudates are left to mature in a water-saturated atmosphere for 24 hours at room temperature, then dried at 160°C for 1 hour before being dry-impregnated again with an aqueous solution containing triethylene glycol (TEG, Merck™) so that the TEG / Mo molar ratio is 0.8. A final drying process is then applied to the extrudates for one hour in air at 90°C. The resulting additive-treated catalyst is designated C3.The final composition of the C3 catalyst expressed as oxides is then as follows: MoO3 = 22 + / - 0.2 (weight %), NiO = 0.2 + / - 0.1 (weight %) and P2O5 = 5.2 + / - 0.1 (weight %).

[0129] Example 4: preparation of a hydrotreating catalyst (C4) (according to the invention)

[0130] Nickel, molybdenum, and phosphorus are added to the same alumina Al support as shown in Example 1. The impregnation solution is prepared by dissolving 29.2 grams of molybdenum oxide (Merck™, purity > 99.5%) at 90°C. weight), 2.4 grams of nickel hydroxycarbonate (Merck™, 99.9% wt. purity), and 11.2 grams of orthophosphoric acid solution (Merck™, 85% wt. in water) in 64.2 mL of distilled water. The molar ratio between the elements of groups VIII and VIB is 0.1 mol / mol. After dry impregnation, the extrudates are left to mature in a water-saturated atmosphere for 24 h at room temperature, then dried at 160°C for 1 hour before being dry-impregnated again with an aqueous solution containing 26.1 grams of triethylene glycol (TEG, Merck™) so that the TEG / Mo molar ratio is 0.8. A final drying is then applied to the extrudates for one hour in air at 90°C. The resulting additive catalyst is designated C4. The final composition of the C4 catalyst expressed in terms of oxides is then as follows: MoO3= 22 + / - 0.2 (% by weight), NiO = 1.1 + / - 0.1 (% by weight) and P2 O5= 5.2 +- 0.1 (% by weight).

[0131] Example 5: preparation of a hydrotreating catalyst (C5) (according to the invention)

[0132] On the same alumina Al support as presented in Example 1, nickel, molybdenum and phosphorus are added. The impregnation solution is prepared by dissolving at 90°C 29.2 grams of molybdenum oxide (Merck™, purity > 99.5% wt), 2.4 grams of nickel hydroxycarbonate (Merck™, purity 99.9% wt), 11.2 grams of an orthophosphoric acid solution (Merck™, 85% wt in water) and 26.1 grams of triethylene glycol (TEG, Merck™) in 41.9 mL of distilled water. After dry impregnation, the extrudates are left to mature in a water-saturated atmosphere for 24 h at room temperature, then they are dried at 90°C for 2 h. The molar ratio between the elements of groups VIII and VIB is 0.1 mol / mol and 0.8 mol / mol between triethylene glycol and molybdenum and 8 between triethylene glycol and nickel.After dry impregnation, the extrudates are left to mature in a water-saturated atmosphere for 24 hours at room temperature, then they are dried at 120°C for 1 hour. The resulting additive catalyst is designated C5. The final composition of catalyst C5, expressed as oxides, is as follows: MoO3 = 22 + / - 0.2 (wt.%), NiO = 1.1 + / - 0.1 (wt.%) and P2O5 = 5.2 + / - 0.1 (wt.%).

[0133] Example 6: preparation of a hydrotreating catalyst (C6) (according to the invention)

[0134] Nickel, molybdenum, and phosphorus are added to the same alumina (Al) support as shown in Example 1. The impregnation solution is prepared by dissolving 29.6 grams of molybdenum oxide (Merck™, purity > 99.5 wt.), 2.4 grams of nickel hydroxycarbonate (Merck™, purity 99.9 wt.), and 11.3 grams of orthophosphoric acid solution (Merck™, 85 wt. in water) at 90°C in 64.2 mL of distilled water. The molar ratio between the elements of The concentration of groups VIII and VIB is 0.1 mol / mol. After dry impregnation, the extrados are left to mature in a water-saturated atmosphere for 24 h at room temperature, then dried at 160°C for 1 hour. The dried, impregnated support of the C6 catalyst is then treated by dry impregnation with a solution containing a mixture of dimethyl succinate (DMSU) and acetic acid (75% purity), with a DMSU / Mo molar ratio of 0.85 mol / mol, an acetic acid / Mo molar ratio of 5.7 mol / mol, a DMSU / Ni molar ratio of 8.5 mol / mol, and an acetic acid / Ni molar ratio of 57.1 mol / mol. The catalyst undergoes a further maturation step of 3 h at 20°C in air, followed by drying in a flow-through bed oven at 120°C for 3 h. A final drying process is then applied to the extrudates for one hour under air at 90°C. The resulting additive-enhanced catalyst is designated C6.The final composition of the C6 catalyst expressed as oxides is then as follows: MoO3 = 22 + / - 0.2 (weight %), NiO = 1.1 + / - 0.1 (weight %) and P2O5 = 5.2 + / - 0.1 (weight %).

[0135] Example 7: Preparation of a hydroconversion catalyst according to the invention (C7)

[0136] For the preparation of the support for catalyst C7, a mixture of alumina gel and ZSM-12 zeolite is shaped by kneading and extrusion through a die with 1.5 mm diameter quadrilobe orifices, dried at 80°C, and calcined at 550°C. The ZSM-12 content in the support is 19 wt%. The support is in extruded form. Nickel and tungsten are added. The zeolite-containing support has a water absorption volume of 0.77 mL / g. The impregnation solution is prepared by dissolving 38.9 grams of ammonium metatungstate and 17.3 grams of nickel nitrate in 75.3 mL / g. After dry impregnation, the extrudates are left to mature in a water-saturated atmosphere for 24 hours at room temperature, then dried at 120°C for 5 hours, before being calcined in air at 450°C for 4 hours. The resulting calcined catalyst is designated C8.The final composition of the C7 catalyst, expressed as oxides, is as follows: WO3 = 25 + / - 0.2 (weight %) and NiO = 3.2 + / - 0.1 (weight %).

[0137] Example 8: Preparation of a hydroconversion catalyst according to the invention (C8)

[0138] Nickel and tungsten are added to 100 grams of an amorphous silica-alumina support having a loss on ignition of 1.5% by weight, a BET surface area of ​​240 m² / g, a pore volume measured by mercury porosimetry of 0.46 mL / g, and which is in extruded form. The silica-alumina support has a water absorption volume of 0.54 mL / g. The impregnation solution is prepared by dissolving 38.9 grams of ammonium metatungstate and 17.3 grams of nickel nitrate. in 56.0 mL of distilled water. After dry impregnation, the extradoses are left to mature in a water-saturated atmosphere for 24 h at room temperature, then dried at 120°C for 5 hours, before being calcined in air at 450°C for 4 hours. The calcined catalyst thus obtained is designated C8. The final composition of catalyst C8, expressed as oxides, is as follows: WO3 = 25 + / - 0.2 (wt.%) and NiO = 3.2 + / - 0.1 (wt.%).

[0139] Examples 9 to 14: Evaluation by hydrotreating and hydroconversion of a feed from a renewable source implementing the sequence of hydrotreating catalysts Cl to C6 respectively with the hydroconversion catalyst C7

[0140] The hydrotreating catalyst Cl was evaluated in a pilot unit, representative in terms of implementation (reaction operating conditions, effluent separation quality) of the industrial process according to the invention. The various steps and unit operations of the pilot unit mimicking the industrial implementation of the process according to the invention are described below. In a temperature-controlled reactor designed to ensure isothermal and fixed-bed operation, the hydrotreating catalyst CL is loaded. Prior to the hydrotreating step of the feed, the catalysts are sulfided in-situ in the unit with isane to which 2% by weight of dimethyl disulfide has been added, under a total pressure of 7 MPa, at a hydrogen / diesel fuel ratio of 1000 Nm3 per m3. The volume of feed to be sulfided per total volume of catalyst per hour is set at 1.The sulfurization process is carried out for 12 hours at 350°C, with a temperature ramp of 10°C per hour.

[0141] Since the catalyst is sulfurized, pre-refined rapeseed oil with a density of 920 kg / m³ and an oxygen content of 11% by weight is hydrotreated. The fatty acid distribution of the rapeseed oil is detailed in Table 1. During the hydrotreating step, the feedstock is treated with dimethyl disulfide to adjust its sulfur content to 50 ppm by weight to maintain the catalyst in the sulfurized state.

[0142] [Tables 1] Fatty acid composition (%) 14:0 0.1 16:0 5.0 16:1 0.3 17:0 0.1 17:1 0.1 18:0 1.5 18:1 trans <0.1 18:1 cis 60.1 18:2 trans <0.1 18:2 cis 20.4 18:3 trans <0.1 18:3 cis 9.6 20:0 0.5 20:1 1.2 22:0 0.3 22:1 0.2 24:0 0.1 24:1 0.2

[0143] Table 1: Characteristics of rapeseed oil used as feedstock for hydrotreating

[0144] After sulfidation, the operating conditions of the unit are adjusted in order to perform the hydrotreatment of the feed: - WH (charge volume / total catalyst volume / hour): 0.41 h - Total working pressure: 7 MPa, - hydrogen / charge ratio: 1000 Nm3 of hydrogen / m3 of charge,

[0145] The hydrogen used is supplied by Air Product and has a purity greater than 99.999% by volume.

[0146] The entire hydrotreated effluent from the hydrotreatment step is separated using a gas / liquid separator to recover a light fraction consisting mainly of hydrogen, propane, water in vapor form, carbon oxides (CO and CO2), and ammonia, and a liquid hydrocarbon effluent consisting mainly of linear hydrocarbons. The water present in the liquid hydrocarbon effluent is removed by sedimentation. The liquid hydrocarbon effluent thus obtained contains an atomic oxygen content of less than 80 ppm by weight, said atomic oxygen content being measured by the infrared adsorption technique described in US patent application 2009 / 0018374, and a sulfur content of 2 ppm by weight and a nitrogen content of less than 1 ppm by weight, said nitrogen and sulfur contents being measured respectively by chemiluminescence and UV fluorescence.

[0147] The hydroconversion catalyst was evaluated in another pilot unit representative in terms of implementation (reaction operating conditions, effluent separation quality) of the industrial process according to the invention and supplied with the liquid hydrocarbon effluent obtained after separation.

[0148] Temperature steps at 250 to 400°C are carried out in order to vary the severity of the hydroconversion and achieve a target value of liquid effluent cloud point of -7°C.

[0149] At the unit outlet, an online analysis by gas chromatography and a gas counter make it possible to calculate the mass of light hydrocarbons produced and present in the hydrogen stream.

[0150] The liquid effluent is accumulated for 12 hours. Said liquid effluent is then weighed and analyzed by simulated distillation (ASTM D2887) to determine the yield of average distillate (120°C+ cut, corresponding to hydrocarbons present in the gas and liquid fraction whose boiling point is greater than 120°C).

[0151] The average distillate yield is calculated as follows:

[0152] Yield (average distillate) = [(mass of liquid effluent * % cut 120°C 7100 + mass of [C8-C13] gas) / (mass of liquid effluent + mass of light hydrocarbons (gas) + mass of water + mass of COX)] * 100

[0153] The mass of liquid effluent corresponds to the mass of the liquid receipt accumulated over 12 hours

[0154] Furthermore, the trouble point is determined by the ASTM D5773 method.

[0155] According to example 9 (not in accordance with the invention), the hydrotreating unit is charged with the Cl catalyst and the hydroconversion unit with the C7 catalyst.

[0156] According to example 10 (not in accordance with the invention), the hydrotreating unit is charged with catalyst C2 and the hydroconversion unit with catalyst C7

[0157] According to example 11 (not in accordance with the invention), the hydrotreating unit is charged with catalyst C3 and the hydroconversion unit with catalyst C7

[0158] According to example 12 (according to the invention), the hydrotreating unit is charged with catalyst C4 and the hydroconversion unit with catalyst C7

[0159] According to example 13 (according to the invention), the hydrotreating unit is charged with catalyst C5 and the hydroconversion unit with catalyst C7

[0160] According to example 14 (according to the invention), the hydrotreating unit is charged with catalyst C6 and the hydroconversion unit with catalyst C7

[0161] The sequence between catalyst Cl and catalyst C7 is defined as the reference. The performance criteria are as follows: - Conversion activity expressed as the temperature increase relative to the reference required to reach a cloud point of -7°C in the liquid effluent. A negative value indicates an increase in activity. - Average distillate yields obtained for a liquid effluent cloud point of -7°C. This is expressed as a deviation from the reference. A negative value indicates a yield loss.

[0162] The main characteristics of the effluents produced and the associated operating conditions are reported in Table 3.

[0163] [Tables3] Example Hydrotreatment catalyst Hydrosomeization catalyst Temperature deviation ( °C) for -7 °C troubleshooting point Average distillate yield deviation at -7°C troubleshooting point (wt%) Example 9 (non-conforming) C7 NiW / ZSM-12-A12 03 BASE BASE Example 1 0 (non-con forme) C2 NiMoP / A12O3 Ni / Mo = 0.4 C7 NiW / ZSM-12-A12 03 0 -4 Example 1 1(non-conform) C3 NiMoPTEG / A13 / Mo NiW / ZSM-12-A12 03 0 -3 Exemple 1 2(confor me) C4 NiMoPTEG / A12O 3 Ni / Mo = 0.1 C7 NiW / ZSM-12-A12 03 0 +2 Exemple 1 3(confor me) C5 NiMoPTEG / A12O 3 0, Ni / Mo 17 = C4 NiW / ZSM-12-A12 03 0 +2 Example 1 4(confor me) C6 NiMoDMSU / A12 03 Ni / Mo = 0,l C7 NiW / ZSM-12-A12 03 0 +2

[0164] Table 3: Main Characteristics of Effluents Produced by Hydrotreating and Hydroisomerization

[0165] The combination of catalyst C2 and catalyst C7 (example 10 not in accordance with the invention) allows the production of a middle distillate cut having a cloud point of -7°C compared to the base case with a yield in middle distillate is reduced by 4 points.

[0166] The combination of catalyst C3 and catalyst C7 (example 11 not in accordance with the invention) allows the production of a middle distillate cut having a cloud point of -7°C compared to the base case by increasing the yield in middle distillate by 3 points.

[0167] The combination of catalyst C4 and catalyst C7 (example 12 according to the invention) allows the production of a middle distillate cut having a cloud point of -7°C compared to the base case by increasing the yield of middle distillate by 2 points.

[0168] The combination of catalyst C4 and catalyst C7 (example 13 according to the invention) allows the production of a middle distillate cut having a cloud point of -7°C compared to the base case by increasing the yield of middle distillate by 2 points.

[0169] The combination of catalyst C5 and catalyst C7 (example 14 according to the invention) allows the production of a middle distillate cut having a cloud point of -7°C compared to the base case by increasing the yield of middle distillate by 2 points.

[0170] It therefore appears that the implementation of a catalyst chain in a two-stage hydrotreating and hydroconversion process of a vegetable oil according to the present invention, and in particular that the implementation in the hydrotreating stage of a specific catalyst comprising at least one metal from group VIII, in combination with at least one metal from group VIB and having an atomic ratio between the elements of group VIB and VIII of between 0.02 mol / mol and 0.2 mol / mol, at least one specific organic additive and an oxide support comprising at least alumina makes it possible to obtain a yield in average distillates without modification of the activity of said hydroconversion catalyst, compared to the implementation of hydrotreating catalysts conventionally used in the prior art in a two-stage process.

[0171] Examples 15 and 16: Evaluation by hydrotreating and hydroconversion of a feed from a renewable source implementing the sequence of hydrotreating catalysts Cl or C4 respectively and with the hydroconversion catalyst C8

[0172] The operating conditions, analyses and calculations carried out are reproduced from examples 9 to 14.

[0173] According to example 15 (not in accordance with the invention), the hydrotreating unit is charged with the Cl catalyst, then the hydroconversion unit is charged with the C8 catalyst.

[0174] According to Example 16 (according to the invention), the hydrotreating unit is charged with catalyst C4 and the hydroconversion unit with catalyst C8. The sequence between catalyst Cl and catalyst C8 is defined as reference

[0175] The main characteristics of the effluents produced and the associated operating conditions are reported in Table 4.

[0176] [Tables4] Example Hydrotreating Catalyst Hydroconversion Catalyst Temperature difference (°C) for a cloud point of -7°C Average distillate yield difference at a cloud point of -7°C (% wt) Example 15 (non-compliant) Cl NiMoP / Al12O3 Ni / Mo = 0.1l C8 NiW / SiAl BASE BASE Example 16 (compliant) C4 NiMoPTEG / Al12O3 Ni / Mo = 0.1l C8 NiW / SiAl 0 +5

[0177] Table 4: Main characteristics of effluents produced by hydrotreatment and hydroisomerization

[0178] The combination of the C4 catalyst and the C8 catalyst (example 16 according to the invention) allows the production of a diesel cut having a cloud point of -7°C compared to the base case by increasing the average distillate yield by 5 points.

Claims

Demands

1. A process for treating a feedstock from a renewable source comprising at least: a) a hydrotreating step of said feedstock in the presence of at least one fixed-bed catalyst, said hydrodeoxygenation catalyst comprising at least one metal of Group VIII, in combination with at least one metal of Group VIB of the periodic table, the atomic ratio between the Group VIB and VIII elements being between 0.02 mol / mol and 0.2 mol / mol, at least one organic additive, and a support comprising at least one oxide, at a temperature between 200 and 450°C, at a pressure between 1 MPa and 10 MPa, at a space-hour velocity between 0.1 h⁻¹ and 10 h⁻¹, and in the presence of a total amount of hydrogen mixed with the feedstock such that the hydrogen / feedstock ratio is between 70 and 1700 Nm³ of hydrogen / m³ of feedstock; b) a separation step of at least a portion of the effluent from step a) in at least a light gaseous fraction,at least one hydrocarbon liquid effluent consisting of n-paraffins, and at least one aqueous liquid effluent, c) a hydroconversion step of at least a portion of the hydrocarbon liquid effluent from step b) in the presence of at least one fixed-bed bifunctional hydroconversion catalyst, said catalyst comprising at least one metal from Group VIII and / or Group VIB of the periodic table, alone or in mixtures, and a support comprising at least one alumina silica and / or one or more zeolites, said hydroconversion step being carried out at a temperature between 250 and 500°C, at a pressure between 1 and 10 MPa, at a spatial rate between 0.1 and 10 h⁻¹, and in the presence of a total quantity of hydrogen mixed with the feed such that the hydrogen / feed ratio is between 70 and 1500 Nm³ / m³ of feed, d) a fractionation step of the effluent from step b) to obtain at least a fraction of diesel fuel.

2. A method according to claim 1 wherein the feedstock from renewable sources is selected from oils and fats of vegetable or animal origin, or mixtures of such feedstocks, containing triglycerides and / or free fatty acids and / or esters.

3. A method according to claim 1 or 2 wherein in step a), the feed is brought into contact with a fixed-bed catalyst at a temperature between 220 and 350°C, at a pressure between 1 MPa and 6 MPa, at a spatial velocity between 0.1 h₁ and 10 h₁. The feed is brought into contact with the catalyst in the presence of hydrogen and in the presence of a total amount of hydrogen mixed with the feed such that the hydrogen / feed ratio is between 150 and 1500 Nm³ of hydrogen / m³ of feed.

4. A method according to any one of claims 1 to 3 wherein the hydrotreating catalyst support implemented in step a) comprises at least one oxide selected from titanium oxide, alumina, silica and zirconia, alone or in mixture, preferably said support comprises at least alumina and preferably, said support is made of alumina and preferably comprises and is preferably made of alumina q, ô or y and preferably made of alumina p, ô or y.

5. A process according to any one of claims 1 to 4 wherein said hydrotreating catalyst implemented in step a) comprises at least one metal from group VIII selected from nickel and cobalt, in combination with at least one metal from group VIB selected from molybdenum and tungsten, taken alone or in mixture.

6. A process according to any one of claims 1 to 5 wherein said hydrotreating catalyst implemented in step a) comprises at least one organic additive selected from organic compounds containing oxygen, organic compounds containing nitrogen, organic compounds containing oxygen and nitrogen and organic compounds containing sulfur, alone or in mixture.

7. A process according to claim 6 wherein said hydrotreating catalyst comprises an organic compound selected from levulinic acid, citric acid, triethylene glycol, diethylene glycol, ethylene glycol, a mixture of acetic acid and dimethyl succinate.

8. A process according to any one of the preceding claims wherein the molar ratio of metal(ux) of groups VIB and VIII in the hydrotreating catalyst used in step a) is between 0.05 mol / mol and 0.15 mol / mol, and preferably between 0.06 and 0.12 mol / mol.

9. A method according to any one of claims 1 to 8, wherein the organic compound(s) is / are introduced into an impregnation solution, which may be the same or a different solution from that containing the precursors of the metals of groups VIB and VIII, in an amount corresponding to: - a molar ratio of the organic compound to the sum of the group VIB elements of the catalyst precursors of between 0.01 and 30 mol / mol, preferably between 0.03 and 15 mol / mol, preferably between 0.05 and 10 mol / mol, and most preferably between 0.1 and 8 mol / mol, calculated on the basis of the components introduced into the impregnation solution(s), and - a molar ratio of the organic compound to the group VIII element(s) of the catalyst precursor (Ni) of between 0.02 and 300 mol / mol, preferably between 0.1 to 150 mol / mol, preferably between 0.5 and 100 mol / mol, and most preferablybetween 1 and 80 mol / mol, calculated based on the components introduced into the impregnation solution(s).

10. A process according to any one of claims 1 to 9, wherein the hydroconversion catalyst support used in hydroconversion step c) comprises at least one zeolite selected from the following structural-type zeolites: MTT, preferably selected from ZSM-23, EU-13, alone or in mixtures; MTW, preferably selected from ZSM-12, TPZ-12, Theta-3, NU-13, CZH-5, alone or in mixtures; BEA, preferably selected from Beta or Tschernichite alone or in mixtures; MOR, preferably selected from mordenite or LZ-211, alone or in mixtures; MRE, preferably ZSM-48; MFI, preferably ZSM-5; FAU, preferably zeolite Y and zeolite IZM-2; and preferably a zeolite selected from ZSM-12 and the IZM-2.

11. A process according to any one of claims 1 to 10 wherein a catalyst of step c) comprises and is preferably made of nickel and tungsten, and a support comprising and preferably made of ZSM-12 zeolite and an alumina binder, said catalyst being in sulfide form.

12. A method according to any one of claims 1 to 10 wherein a catalyst of step c) comprises and is preferably made up of of at least tungsten and / or molybdenum and at least nickel and / or cobalt and preferably nickel and tungsten, and a silica-alumina as an acid support, without any other binder, said catalyst being in sulfide form.