Method for the pretreatment by hydrolysis of a hydrocarbon feedstock of natural origin mixed with a feedstock of fossil origin

Abstract

The invention relates to a method for the pretreatment by hydrolysis of a hydrocarbon feedstock of natural origin containing fatty acid esters, wherein the hydrocarbon feedstock of natural origin is brought into contact with water in a hydrolysis zone (10) in order to produce a first effluent enriched with free fatty acids and a second effluent enriched with alcohol and water. A diluent is further introduced into the hydrolysis zone. According to the invention, the diluent is a hydrocarbon effluent comprising a component of fossil origin. This hydrocarbon effluent comprises an effluent from a hydroconversion treatment of a hydrocarbon feedstock of fossil origin and a hydrocarbon feedstock comprising a hydrolysed component of natural origin, and / or a liquid fraction of this effluent. The invention also relates to a method and to a unit for producing hydrocarbon fluids, incorporating the pretreatment of the invention upstream of a hydroconversion step.

Description

TITLE: PROCESS FOR PRETREATMENT BY HYDROLYSIS OF A HYDROCARBON FEED OF NATURAL ORIGIN MIXED WITH A FEED OF FOSSIL ORIGIN Technical field

[0001] The present invention relates to the pretreatment by hydrolysis of hydrocarbon feedstocks of natural origin in admixture with a feedstock resulting from the refining of hydrocarbon feedstocks of fossil origin and a method for manufacturing hydrocarbon fluids from complex mixtures of hydrocarbons of renewable and fossil origin comprising this pretreatment. In particular, the present invention relates to a method for the coprocessing conversion of a biological raw material comprising fatty acid esters (FAE) into free fatty acids (FFA) and then into oxygen-free paraffinic compounds, which can be used as fuels. Background to the invention

[0002] Due to the scarcity of fossil resources and growing environmental concerns, the use of biomass-derived molecules is increasingly sought to replace molecules of fossil origin. In particular, some countries, such as France, are implementing taxes on aviation fuels. In particular, the regulation on establishing a level playing field for a sustainable aviation sector in the European Union (also known as the "ReFuelEU Aviation initiative") aims to increase the use of sustainable fuels by aircraft and ships in order to reduce their environmental footprint. Thus, by 2025, 2% of the jet fuel used in the European Union must be of renewable origin.Thus, the preparation of jet fuel, or other hydrocarbon fuels or fluids, from molecules derived from biomass constitutes a real economic, environmental and strategic challenge. Prior art

[0003] Today, there are many processes for manufacturing fuel that includes a component of biological origin.

[0004] A well-known process for manufacturing renewable fuel and other hydrocarbon fluids involves hydrotreating a vegetable or animal fat or oil and a fossil feedstock in the presence of hydrogen and a catalyst. Such coprocessing limits the high exothermicity of triglyceride hydrotreatment. However, corrosion phenomena are observed due to the acidity of the treated vegetable and / or animal oils.

[0001] Typically, in this type of process, the dihydrogen that has not reacted during the hydrotreatment step is separated from the hydrotreatment effluent and reused. However, when a vegetable or animal fat or oil is co-processed with a fossil feedstock, there is a dilution of the dihydrogen with propane (from glycerol) produced during hydroprocessing, which increases the propane ballast in the unconverted dihydrogen stream to be recycled or the need to separate the dihydrogen-propane gas mixture before recycling the unconverted dihydrogen or the purging of this stream to maintain the propane ballast below a certain concentration (and thus the overall dihydrogen consumption).

[0002] This increase in the overall consumption of dihydrogen is also observed in the hydrotreatment processes of feedstocks of biological origin alone. One way of reducing the formation of propane is then to pretreat the feedstock of biological origin by hydrolysis. Hydrolysis also makes it possible to reduce the consumption of dihydrogen to the extent that the triglycerides present are partly "cut" during this pretreatment and consequently the glycerol is no longer converted during the hydrotreatment.

[0003] Document WO2021 / 028833 describes a hydrolysis pretreatment in which a crude used oil (which may be cooking oil, category 1 animal fats or residual oils) is hydrolyzed in the presence of an effluent containing mono-, di- and triglycerides of fatty acids free of impurities leaving an esterification unit. The addition of this effluent makes it possible to dilute the contaminants present in the used oil, to improve the homogenization of the feedstock and the removal of impurities. The free fatty acids produced during the hydrolysis are then sent to a hydrotreatment unit and then to an isomerization and cracking unit. The glycerol produced during the hydrolysis is sent with a portion of the fatty acids produced by the hydrolysis to an esterification unit producing the effluent which is hydrolyzed with the crude oil.This process, however, requires the integration of an esterification unit in addition to the hydrotreatment and isomerization units.

[0004] Document US 10,071,322 also describes a pretreatment by hydrolysis of a renewable feedstock mixed or not with a feedstock of fossil origin making it possible to reduce the contaminant content of the treated feedstocks. The feedstocks of fossil origin used are crude oil and bottoms from atmospheric or vacuum distillation columns.

[0005] However, there is still a need to improve existing processes.

[0006] The invention aims in particular to propose a process for pretreatment by hydrolysis of a hydrocarbon feedstock of natural origin, intended in particular to be integrated into an existing process for manufacturing hydrocarbon fluids without major modification thereof. Description of the invention

[0007] The invention provides a process for pretreatment by hydrolysis of a hydrocarbon feedstock of natural origin containing fatty acid esters, in which: said hydrocarbon feedstock of natural origin is brought into contact with water in a hydrolysis zone to produce a first effluent enriched in free fatty acids, optionally containing fatty acid esters, and a second effluent rich in alcohol and water, and a diluent is introduced into the hydrolysis zone.

[0008] According to the invention, the diluent is a hydrocarbon effluent comprising a component of fossil origin, and this hydrocarbon effluent comprises an effluent from a hydroconversion treatment of a hydrocarbon feedstock of fossil origin mixed with a hydrocarbon feedstock comprising a hydrolyzed component of natural origin, and / or a liquid fraction of this effluent. In one embodiment, the hydrocarbon effluent consists of such an effluent from a hydroconversion treatment and / or a fraction of this effluent.

[0009] Dilution with a mixture of hydrocarbons thus carried out can allow better phase separation of the polar / apolar phases present in the hydrolysis zone, and thus improve the hydrolysis reaction (for example, promote the completion of the hydrolysis reaction). This dilution also makes it possible to reduce corrosion phenomena and improve the elimination of impurities. In particular, the inorganic species of said feedstock will be detached from the fatty acid esters and, preferably, dissolve in the aqueous phase.

[0010] When the diluent comprises, or consists of, a liquid fraction of the hydrocarbon effluent, this fraction can advantageously be chosen from a naphtha fraction, a kerosene fraction, a diesel fraction.

[0011] The quantity of diluent introduced into the hydrolysis zone may advantageously represent 0.5 to 150% by mass of the total feedstock to be treated introduced into said zone. The total feedstock to be treated consists of said hydrocarbon feedstock of natural origin, and optionally of at least one liquefaction oil of a hydrocarbon feedstock chosen from a biomass oil and a plastic oil.

[0012] Advantageously, the diluent can be introduced into the hydrolysis zone at a temperature of 200°C to 350°C. This can be achieved in particular without preheating the diluent when it is taken directly from the outlet of a treatment or separation zone, without intermediate cooling. In this case, the naturally occurring hydrocarbon feedstock can be introduced into the hydrolysis zone at a temperature of 50 to 250°C.

[0013] Advantageously, the hydrocarbon feedstock of natural origin containing fatty acid esters used in the pretreatment process may comprise, or consist of, an oil of natural origin, an esterified oil of natural origin or mixtures thereof. This oil of natural origin may in particular be chosen from a vegetable oil, an animal oil or fat, a used oil, an oil produced by microorganisms, as well as their mixtures. Used oil should preferably be used.

[0014] In one embodiment, it is also possible to introduce into said hydrolysis zone at least one liquefaction oil of a hydrocarbon feedstock chosen from a biomass oil and a plastics oil, the at least one liquefaction oil of a hydrocarbon feedstock representing at most 10% by mass of the hydrocarbon feedstock of natural origin introduced into said hydrolysis zone.

[0015] Whatever the embodiment, the hydrolysis can be carried out under one or more of the following conditions: a temperature of 130 to 350°C, a pressure of 7 to 100 barg, a water / naturally occurring hydrocarbon feedstock mass ratio of 0.1 to 2, preferably of 0.25 to 1.5

[0016] Another subject of the invention relates to a process for manufacturing hydrocarbon fluids from a hydrocarbon feedstock of natural origin containing fatty acid esters, and from a hydrocarbon feedstock of fossil origin, in particular chosen from a naphtha cut, a kerosene cut, a diesel cut and a distillate cut, the process comprising at least: a) a step of pretreatment by hydrolysis of the hydrocarbon feedstock of natural origin in which said hydrocarbon feedstock of natural origin is brought into contact with water in a hydrolysis zone to produce a first effluent enriched in free fatty acids, optionally containing fatty acid esters, and a second effluent rich in alcohol and water, b) an optional step of separation and / or purification of the first effluent enriched in free fatty acids from step a) during which the alcohols are removed from the first effluent,residual inorganic impurities and / or water to obtain a first purified effluent, c) a hydroconversion step, in which said hydrocarbon feedstock of fossil origin and the first effluent from step a), optionally purified in step b), are brought into contact with dihydrogen in a hydroconversion zone in the presence of at least one catalyst under conditions suitable for carrying out hydroconversion and forming a hydroconverted effluent comprising a hydroconverted liquid fraction and a fraction of incondensable components, d) a step of separating the hydroconverted effluent from step c) during which the fraction of incondensable components is separated from the hydroconverted liquid fraction.,

[0017] According to the invention, step a) is carried out according to the pretreatment method of the invention, said diluent introduced into the hydrolysis zone being chosen from (i) a part of the hydroconverted effluent from step c), (ii) part of the hydroconverted liquid fraction from step d), or (iii) a mixture of (i) and (ii).

[0018] The pretreatment process according to the invention can thus be easily integrated into a conventional hydrocarbon fluid manufacturing process in that it is sufficient to add pipes for recycling the effluent leaving steps c) or d) to the hydrolysis step a), without having to add additional treatment units such as in particular an esterification unit.

[0019] In particular, the portions of the effluents leaving steps c) or d) used as diluent may come directly from steps c) or d) respectively, without intermediate cooling. The effluents leaving steps c) or d) are then sent directly, without intermediate cooling, to the hydrolysis step for better thermal integration. The temperature of the diluent, comprising a portion of one or more of the aforementioned effluents, may then be maintained at a temperature of 200°C to 350°C, which makes it possible to limit the heating of the naturally occurring hydrocarbon feedstock, the latter being able to be heated to a temperature of 50°C to 250°C.

[0020] Thus, advantageously, the temperature of the diluent introduced into the hydrolysis zone can be 200 to 350°C.

[0021] The process according to the invention may further comprise a second step e) of fractionation of the hydroconverted liquid fraction of step d), in which said hydroconverted liquid fraction is separated into at least one liquid fraction chosen from a naphtha fraction, a diesel fraction and a kerosene fraction, and said diluent introduced into the hydrolysis zone comprises a portion of the at least one separated liquid fraction.

[0022] The quantity of first effluent introduced into the hydroconversion zone may advantageously represent from 0.5 to 90% by mass, more preferably from 0.5 to 50% by mass, more preferably from 5 to 25% by mass of the total feed (first effluent and hydrocarbon feed of fossil origin) introduced into the hydroconversion zone of step c).

[0023] In the manufacturing process according to the invention, at least a portion of the incondensable components separated in step d) may be sent to the hydrolysis zone, optionally after removal of components other than dihydrogen.

[0024] The invention also relates to a hydrocarbon fluid manufacturing unit suitable for implementing the manufacturing method according to the invention.

[0025] Thus, another subject of the invention relates to a unit for manufacturing hydrocarbon fluids from a hydrocarbon feedstock of natural origin containing fatty acid esters and a hydrocarbon feedstock of fossil origin, comprising: a hydrolysis zone comprising at least one first inlet pipe for the hydrocarbon feedstock of natural origin containing fatty acid esters, a second inlet pipe for water, a first outlet pipe for a first effluent and a second outlet pipe for a second effluent, and optionally an additional inlet pipe, an optional separation and / or purification treatment zone connected to the first outlet pipe of the hydrolysis zone, a hydroconversion zone comprising at least one inlet connected to the first outlet pipe of the hydrolysis zone or to an outlet of the optional treatment zone, an inlet pipe for a gas containing dihydrogen, an inlet pipe for a feedstock of fossil origin and an outlet pipe for a hydroconverted effluent, a separation zone connected to the outlet pipe of the hydroconversion zone,characterized in that it comprises at least one recycle pipe connected on the one hand to the hydrolysis zone or to an inlet pipe of the hydrolysis zone and on the other hand to the outlet pipe of the hydroconversion zone or to an outlet pipe of the separation zone.,

[0026] In one embodiment, the unit may further comprise a fractionation zone having an inlet connected to an outlet pipe of the first separation zone, and at least one outlet pipe, and the unit comprises at least one recycle pipe connected on the one hand to the hydrolysis zone or to an inlet pipe of the hydrolysis zone and on the other hand to at least one outlet pipe of the fractionation zone.

[0027] Advantageously, the unit's recycle lines are connected directly to the elements they connect, without intermediate cooling equipment. Detailed description of the invention

[0028] The terms "comprising" and "comprises" as used herein are synonymous with "including," "includes," or "contains," "containing," and are inclusive or unbounded and do not exclude additional features, elements, or method steps not specified.

[0029] The expressions % by weight and % by mass (also noted %m) have an equivalent meaning and refer to the proportion of the mass of a product relative to 100g of a composition comprising it.

[0030] Boiling points as mentioned here are measured at atmospheric pressure, unless otherwise stated. An initial boiling point is defined as the temperature value at which a first vapor bubble is formed. A final boiling point is the highest temperature achievable during a distillation. At this temperature, no more vapor can be transported to a condenser. The determination of the initial and final points uses techniques known in the art and several methods adapted according to the distillation temperature range. are applicable, for example NF EN 15199-1 (2020 version) or ASTM D2887 for the measurement of boiling points of petroleum fractions by gas chromatography, ASTM D7169 for heavy hydrocarbons, ASTM D7500, D86 or D1160 for distillates.

[0031] In the following description, the different embodiments described, and in particular the preferred embodiments of each step, can be combined according to the desired objective.

[0032] Naturally occurring hydrocarbon feedstock containing fatty acid esters

[0033] “Naturally occurring hydrocarbon feedstock” means a hydrocarbon feedstock that does not contain components of fossil origin.

[0034] The naturally occurring hydrocarbon feedstock containing fatty acid esters used in the present invention may comprise, or consist of, a naturally occurring oil, an esterified naturally occurring oil, or mixtures thereof.

[0035] The hydrocarbon feedstock of natural origin used in the present invention may thus comprise, or consist of, an oil of natural origin or a mixture of oils of natural origin, esters resulting from the transesterification of fatty acid esters and / or from the esterification of fatty acids contained in one or more oils of natural origin, as well as their mixtures.

[0036] Naturally occurring oil can be chosen from vegetable oil, animal oil or fat, used oil, oil produced by microorganisms, as well as their mixtures.

[0037] A naturally derived oil is defined as an oil that does not contain mineral oil of fossil origin.

[0038] Typically, an oil of natural origin may contain 50%m or more, preferably 60%m or more, preferentially 70%m or more, of fatty acids and / or fatty acid esters (mono-, di-, triglycerides).

[0039] In one embodiment, a naturally occurring oil may contain fatty acid esters (mono-, di-, or triglycerides) and / or free fatty acids, containing one to three C8-C24 acyl groups, saturated or unsaturated. When multiple acyl groups are present, they may be the same or different.

[0040] The vegetable oil can be chosen from pine oil, rapeseed oil, sunflower oil, castor oil, peanut oil, linseed oil, babasu oil, hemp oil, linola oil, jatropha oil, peanut oil, rice bran oil, mustard oil, carinata oil, coconut oil, copra oil, olive oil, palm oil, cottonseed oil, corn oil, palm kernel oil, soybean oil, pumpkin oil, grapeseed oil, argan oil, jojoba oil, sesame oil, walnut oil, hazelnut oil, tung oil, rice bran oil, safflower oil, algae oil, waste oil, nut shell oil (including cashew nut shell oil), and any combination thereof.

[0041] Used oil includes used cooking oils or used edible oils and oils recovered from waste water, such as grease / trap and drain oils, gutter oils, sewer oils, e.g. from water treatment plants, used fats from the food industry, and used cooking oils that are animal by-products.

[0042] Animal fat can be chosen from tallow, lard, fat (yellow and brown fat), fish oil / fat, milk fat, animal fats which are animal by-products.

[0043] In particular, animal fats and used cooking oils which are animal by-products have the status of animal by-products within the meaning of Regulation (EC) No 1069 / 2009 of the European Parliament and of the Council of 21 October 2009 and Commission Regulation (EU) No 142 / 2011 (implementing regulation of Regulation EC No 1069 / 2009).

[0044] Animal fats with animal by-product status are fatty residues of animal origin, other than used cooking oils, originating for example from food industries or rendering plants.

[0045] Used cooking oils with the status of animal by-products are used cooking oils (used cooking oils or UCO), namely residues of fats of vegetable or animal origin used for human consumption, in the food industry, in collective or commercial catering.

[0046] Naturally occurring oil can also be oil produced by microorganisms, whether natural or genetically modified, such as bacteria, yeasts, including oleaginous yeasts, algae, prokaryotes, or eukaryotes. In particular, these oils can be recovered by well-known mechanical or chemical extraction methods.

[0047] The above-mentioned oils, most of which are rich in triglycerides, additionally contain varying amounts of non-triglyceride components such as free fatty acids, mono- and diglycerides, and many other organic and inorganic components, including phosphatides, sterols, tocopherols, tocotrienols, hydrocarbons, pigments (gossypol, chlorophyll), vitamins (carotenoids), sterol glucosides, glycolipids, protein fragments, traces of pesticides and traces of metals, as well as resinous and mucilaginous materials.

[0048] Preferably, the oils of natural origin used in the present invention have not undergone any pretreatment, such as the chemical and physical pretreatments usually carried out by those skilled in the art, similar to those carried out for the treatment of edible oils, such as degumming, neutralization with an alkaline solution (generally NaOH), bleaching, finishing or polishing, steam treatment, cavitation, etc. Thus, in one embodiment, the oils of natural origin treated in the present invention are “crude” oils, not having undergone any pretreatment.

[0049] Compositions resulting from the transesterification of fatty acid esters and / or from the esterification of fatty acids contained in the aforementioned oils of natural origin, such as compositions comprising alkyl esters of fatty acids, and in particular methyl esters of fatty acids or ethyl esters of fatty acids, and comprising impurities originating from the oils, may also form part of the hydrocarbon feedstocks of natural origin considered in the present invention.

[0050] The hydrocarbon feedstock of natural origin used in the present invention may thus contain 50% by weight or more, preferably 60% by weight or more, preferentially 70% by weight or more, of fatty acids and / or fatty acid esters (mono-, di-, triglycerides, alkyl esters of fatty acids, and in particular ethyl esters of fatty acids, methyl esters of fatty acids). In general, the hydrocarbon feedstock of natural origin comprises at most 99% by weight of fatty acids and / or fatty acid esters.

[0051] The phosphorus content of the naturally occurring hydrocarbon feedstock may be 20 ppm or more or 50 ppm or more, for example 50 ppm to 1500 ppm, or 200 ppm to 1200 ppm, measured for example by X-ray fluorescence or ICP using the UOP 389 method, or by ICP AES Dilution or ICP microwave digestion in a closed environment.

[0052] The nitrogen content of the naturally occurring hydrocarbon feedstock may be 20 ppm or more, for example 50 ppm to 1200 ppm or 200 ppm to 2000 ppm, measured for example by X-ray fluorescence or chemiluminescence.

[0053] The naturally occurring hydrocarbon feedstock may further comprise one or more other heteroatoms such as alkali metals, in particular potassium, alkaline earth metals, and / or chlorine. The content of these heteroatoms may vary depending on the constituents of the composition. It may be determined by elemental analysis of the X-ray fluorescence type or by ICP.

[0054] Liquefaction oil of a hydrocarbon feedstock

[0055] "Liquefaction oil" means an oil resulting from a pyrolysis process and / or a hydrothermal liquefaction process of a hydrocarbon feedstock. This hydrocarbon feedstock may include plastics and / or biomass, alone or in a mixture, in particular in the form of waste. A liquefaction oil may be formed from a mixture of two or more liquefaction oils resulting from the liquefaction of different hydrocarbon feedstocks, each obtained by pyrolysis or hydrothermal liquefaction.

[0056] The pyrolysis process should be understood as a thermal cracking process in the absence of air, typically carried out at a temperature of 300 to 1000°C or 400 to 700°C, carried out in the presence or absence of a catalyst and / or a gas (fast pyrolysis, flash pyrolysis, catalytic pyrolysis, hydropyrolysis, steam pyrolysis, etc.).

[0057] Hydrothermal liquefaction (HTL) is a thermochemical conversion process using water as a solvent, reactant, and catalyst for the degradation reactions of a hydrocarbon feedstock, the water typically being in a subcritical or supercritical state. The hydrothermal liquefaction process is typically carried out at a temperature of 250 to 500 °C and at pressures of 10 to 25-40 Mpa in the presence of water.

[0058] The liquefaction oil optionally used in the present invention may comprise, or consist of, a plastics oil, a biomass oil, and mixtures thereof. In one embodiment, the liquefaction oil optionally used in the present invention may comprise, or consist of, a biomass oil.

[0059] The expression "plastic oil" designates liquid hydrocarbon products obtained following pyrolysis or hydrothermal liquefaction of thermoplastic and / or thermosetting and / or elastomeric polymers, alone or in a mixture, and generally in the form of waste, optionally in a mixture with at least one other feedstock, in particular in the form of waste, such as biomass, for example chosen from lignocellulosic biomass, herbaceous biomass, aquifer biomass, paper and cardboard, organic waste (forestry, agricultural, industrial and / or household waste), food waste, alone or in a mixture.

[0060] Plastic can be of any type, including any type of new or used plastic, included in household (post-consumer) or industrial waste. By plastics is meant materials consisting of polymers and optionally auxiliary components such as plasticizers, fillers, colorants, catalysts, flame retardants, stabilizers, etc. For example, these polymers can be polyethylene, halogenated polyethylene (Cl, F), polypropylene, polystyrene, polybutadiene, polyisoprene, poly(ethylene terephthalate) (PET), acrylonitrile-butadiene-styrene (ABS), polybutylene, poly(butylene terephthalate) (PBT), polyvinyl chloride (PVC), polyvinylidene chloride, a polyester, a polyamide, a polycarbonate, a polyether, an epoxy polymer, a polyacetal, a polyimide, a polyesteramide, biopolymers such as polylactic acid, the polyhydroxyacid(s), polyethylene furanate (PEF), polybutylsuccinate (PBS) etc. Elastomers are linear or branched polymers transformed by vulcanization into a weakly crosslinked, infusible and insoluble three-dimensional network. They include natural or synthetic rubbers. They can be part of tire-type waste or any other household or industrial waste containing elastomers, natural and / or synthetic rubber, mixed or not with other components, such as plastics, plasticizers, fillers, vulcanizing agents, vulcanization accelerators, additives, etc.Examples of elastomeric polymers include ethylene-propylene copolymers, ethylene-propylene-diene terpolymer (EPDM), polyisoprene (natural or synthetic), polybutadiene, styrene-butadiene copolymers, isobutene-based polymers, isobutylene isoprene copolymers, chlorinated or brominated, butadiene acrylonitrile copolymers (N BR), and polychloroprenes (CR), polyurethanes, silicone elastomers, etc.

[0061] Generally speaking, any polymer or mixture of polymers capable of producing hydrocarbons by liquefaction can be used.

[0062] In one embodiment, the plastic oil may be derived from the liquefaction of plastic waste that does not include tires and / or latex (vulcanized or not).

[0063] Plastic oils contain paraffins, i-paraffins (isoparaffins), dienes, alkynes, olefins, naphthenes, and aromatics. Plastic liquefaction oils also contain impurities containing heteroatoms, such as chlorinated, oxygenated, sulfurous, nitrogenous, and / or silylated organic compounds, metals, salts, and phosphorus compounds.

[0064] The composition of a plastic oil depends on the nature of the liquefied plastic, and optionally on any other waste liquefied with the plastic, and is essentially (notably at more than 80% m, most often at more than 90% m) made up of hydrocarbons having from 1 to 150 carbon atoms and impurities.

[0065] A plastic oil typically comprises 5 to 80%m of paraffins (including cycloparaffins), 10 to 95%m of unsaturated compounds (including olefins, dienes and acetylenes), 5 to 70%m of aromatics. These contents can be determined by gas chromatography. In particular, a plastic oil may comprise a Bromine number of 10 to 130 g Br2 / 100g, as measured according to ASTM D1159, and / or a Maleic Anhydride Number (UOP326-82) of 1 to 55 mg maleic anhydride / 1g.

[0066] A plastic oil may have an initial boiling point of at least 15°C, and a final boiling point of at most 800°C, preferably at most 600°C, even more preferably at most 560°C, more preferably at most 450°C, even more preferably at most 350°C, preferably 250°C (measured according to standard NF EN 15199-1 / 2).

[0067] A plastic oil typically contains at least 20 ppm of heteroatoms, or even at least 30 ppm of heteroatoms.

[0068] A plastic oil may include one or more of the following heteroatom contents: 0 to 8%m of oxygen (measured according to ASTM D5622), 1 to 13000 ppm of nitrogen (measured according to ASTM D4629), 2 to 10000 ppm of sulfur (measured according to ISO 20846), 1 to 10000 ppm of metals (measured by ICP), 50 to 6000 ppm of chlorine (measured according to ASTM D7359-18), 0 to 200 ppm of bromine (measured according to ASTM D7359-18), 1 to 40 ppm of fluorine (measured according to ASTM D7359-18), 1 to 2000 ppm of silicon (measured by XRF).

[0069] The term "biomass oil" refers to liquid hydrocarbon products obtained from pyrolysis or hydrothermal liquefaction of one or more biomasses.

[0070] Biomass can be defined as an organic plant or animal product.

[0071] In one embodiment, the biomass oil may advantageously be derived from a biomass chosen from lignocellulosic biomass, herbaceous biomass, aquifer biomass, paper and cardboard, organic waste (forestry, agricultural, industrial and / or household waste), alone or as a mixture.

[0072] Biomass can thus include (i) biomass produced from surplus agricultural land, preferably not used for human or animal food: dedicated crops, called energy crops (short rotation coppice (SRC), very short rotation coppice (VRC); (ii) biomass produced by deforestation (forest maintenance) or clearing of agricultural land, etc.; (iii) agricultural residues from crops, in particular cereal crops, vines, orchards, olive trees, fruits and vegetables including nuts, agri-food residues, etc.; (iv) forest residues from forestry and wood processing; (v) agricultural residues from livestock farming (manure, slurry, bedding, droppings, etc.); (vi) household organic waste (paper, cardboard, green waste, etc.); (vii) industrial organic waste (paper, cardboard, wood, putrescible waste, etc.)); (viii) algal biomass, namely biomass formed from algae, for example micro-algae (algal biomass may be an algae suspension obtained by harvesting algae from, for example, a bioreactor, or an algae residue obtained by dehydrating an algae suspension) or macro-algae; (ix) herbaceous biomass; (x) vegetable oils contained in certain waste (cashew nut shells or other), (xi) industrial waste (wood type B), (xii) sludge from sewage treatment plants, (xiii) digestates from methanizers.

[0073] Biomass oil can contain from 8 to 55% by mass of oxygen. This oxygen is present in oxygenated compounds containing at least one hydroxyl group (-OH) and / or at least one carbonyl group (>C=O). Biomass oil may contain, in particular, carboxylic acids, ketones, aldehydes, phenols.

[0074] Hydrocarbon feedstock comprising a hydrolyzed component of natural origin

[0075] By "hydrocarbon feedstock comprising a hydrolyzed component of natural origin" is meant an oil of natural origin, an esterified oil of natural origin or mixtures thereof, having undergone a hydrolysis treatment in a mixture with a hydrocarbon feedstock comprising, or consisting of, a component of fossil origin, and optionally a component of natural origin. The oil of natural origin is as defined above. It may in particular be chosen from a vegetable oil, an animal oil or fat, a used oil, an oil produced by microorganisms.

[0076] The hydrolysis may be as described below with reference to the hydrolysis pretreatment according to the invention. The hydrocarbon feedstock comprising a hydrolyzed component of natural origin may in particular consist of the first effluent from the hydrolysis pretreatment according to the invention, optionally the first purified effluent from the optional step b) of the process for manufacturing hydrocarbon fluids according to the invention.

[0077] The naturally occurring component of the hydrocarbon feedstock comprising a hydrolyzed naturally occurring component is enriched in free fatty acids, and typically contains at least 10% by mass of free fatty acids. This component generally also contains fatty acid esters, typically in a content of at most 90% by mass.

[0078] The feedstock comprising a hydrolyzed component of natural origin may be subjected to a subsequent hydroconversion treatment in a mixture with a feedstock of fossil origin to produce a hydroconversion effluent comprising, and in particular consisting of, a fossil component and a component of natural origin.

[0079] A. Hydrolysis pretreatment process

[0080] The pretreatment process according to the invention makes it possible to hydrolyze at least part of the esters present in a hydrocarbon feedstock of natural origin in order to obtain free fatty acids and alcohols. It is therefore the reverse reaction of an esterification reaction.

[0081] In this step, the naturally occurring hydrocarbon feedstock reacts with water under appropriate conditions to form free fatty acids and alcohols resulting from the dissociation of esters.

[0082] The hydrocarbon feedstock may contain mono-, di- or triglycerides of fatty acids, and / or alkyl esters of fatty acids, and in particular ethyl esters of fatty acids and methyl esters of fatty acids. The alcohols thus include glycerol, alkyl alcohols, and in particular ethanol and methanol, and other alcohols resulting from the partial or total hydrolysis of the fatty acid esters present. The fatty acids released depend on the nature of the natural oil used.

[0083] Typically, the hydrolysis may be carried out at a temperature of 130 to 350°C, preferably 140 to 300°C, more preferably 140 to 250°C, and at a pressure of 7 to 100 barg (bar gauge), preferably 7 to 50 barg.

[0084] The hydrolysis is typically carried out in the presence of excess water. The water / hydrocarbon feedstock mass ratio may be from 0.1 to 2, preferably from 0.25 to 1.5, more preferably from 0.35 to 1 and even more preferably from 0.4 to 0.75 (this corresponds to weight percents of about 9%m to 66%m, preferably from 20%m to 60%m of water in the combined feedstock, preferably from 25%m to 50%m and even more preferably from 28%m to 42%m).

[0085] The water may be introduced in liquid form, for example using a pump or a control valve, and then heated to produce a mixture of liquid water and steam at a high temperature, for example at least 250 °C, this introduction being able to be carried out at one or more points in the hydrolysis zone. Optionally, superheated steam may also be introduced to also provide heat to further heat the feedstock, for example steam at 300 to 500 °C at the hydrolysis pressure (typically 50 barg). This introduction may be carried out at one or more points in the hydrolysis zone. Also, a combination of preheated water and steam may be used and introduced at one or more points in the hydrolysis zone.

[0086] Hydrolysis is typically carried out without a catalyst.

[0087] The hydrolysis products form a mixture of fatty acids and alcohols. This mixture is biphasic and consists of a denser aqueous phase containing some of the alcohols and a less dense phase containing the fatty acids and some of the alcohols. The aqueous phase also contains most of the impurities initially present in the hydrocarbon feedstock, such as, for example, metals, chlorine, sulfur (mainly in the form of sulfate ions) and phosphorus (mainly in the form of phosphate ions).

[0088] The hydrolysis zone may include one or more reactors operating in batch or continuous mode. For example, a countercurrent reactor or a cocurrent reactor equipped with a static mixer may be used. The hydrolysis zone may contain packing to improve contact between the different phases of the reactor.

[0089] Typically, the two phases of the biphasic mixture are extracted separately from the hydrolysis zone, with the phase containing the fatty acids being extracted from a part upper part of the first zone and forming a first effluent enriched in free fatty acids, and optionally containing fatty acid esters, and the denser aqueous phase typically being drawn off from a lower part of the first zone and forming a second effluent rich in alcohol and water.

[0090] According to the invention, a diluent is also introduced into the hydrolysis zone, which may be a hydrocarbon effluent comprising a component of fossil origin, a liquid fraction of a hydrocarbon effluent comprising a component of fossil origin or their mixtures.

[0091] This hydrocarbon effluent is an effluent from a hydroconversion treatment of a hydrocarbon feedstock of fossil origin and a hydrocarbon feedstock comprising a hydrolyzed component of natural origin. A fraction or all of this hydrocarbon effluent may be sent to the hydrolysis zone.

[0092] The hydroconversion treatment may include hydrodesulfurization, hydrocracking or hydrotreatment of a hydrocarbon feedstock of fossil origin chosen from a naphtha cut, a diesel cut, a kerosene cut and a distillate cut.

[0093] The hydroconversion treatment may for example be chosen from (i) a hydrodesulfurization of a diesel cut of fossil origin mixed with a hydrocarbon feedstock comprising a hydrolyzed component of natural origin, (ii) a hydrodesulfurization of a kerosene cut of fossil origin mixed with a hydrocarbon feedstock comprising a hydrolyzed component of natural origin, (iii) a hydrocracking of distillates of fossil origin mixed with a hydrocarbon feedstock comprising a hydrolyzed component of natural origin, (iv) a hydrotreatment of a kerosene cut of fossil origin mixed with a hydrocarbon feedstock comprising a hydrolyzed component of natural origin, (v) a hydroisomerization of a kerosene or diesel cut of fossil origin mixed with a hydrocarbon feedstock comprising a hydrolyzed component of natural origin.

[0094] Advantageously, the hydrocarbon effluent may comprise, or consist of, at least one fraction chosen from a naphtha fraction, a diesel fraction and a kerosene fraction. Preferably, this fraction is obtained from the hydroconversion treatment of a feedstock of fossil origin, typically a naphtha cut, a diesel cut, a distillate cut or a kerosene cut, in a mixture with a hydrocarbon feedstock comprising a hydrolyzed component of natural origin.

[0095] Said hydrocarbon feedstock of natural origin is thus hydrolyzed in the presence of this diluent. This introduction of a diluent can be carried out in a mixture or not with said hydrocarbon feedstock of natural origin.

[0096] Adding a diluent can allow:

[0097] - better phase separation of polar products, such as glycerol and inorganic impurities of non-polar products such as free fatty acids,

[0098] - a limitation of corrosion in the hydrolysis zone due to the free fatty acids present in the naturally occurring hydrocarbon feedstock,

[0099] - better thermal integration when the diluent is introduced into the hydrolysis zone directly at the outlet of a hydroconversion or separation zone, without intermediate cooling.

[0100] In addition, hydrolysis itself allows: elimination of metals and heteroatoms present (notably P) in the hydrocarbon feedstock of natural origin, these contaminants being found in the aqueous phase which is separated from the hydrocarbon feedstock of natural origin, limitation of propane production during subsequent hydroconversion, reduction of dihydrogen consumption during subsequent hydroconversion.

[0101] In one embodiment, the diluent may be introduced into the hydrolysis zone at a temperature of 200 to 350°C, typically 230 to 280°C.

[0102] Advantageously, the diluent can come directly from a hydroconversion step or a separation step, without intermediate cooling. It can then be at a temperature of 200 to 350 °C, typically 230 to 280 °C.

[0103] Introducing the diluent at a temperature of 200°C or more into the hydrolysis zone limits the preheating of the naturally occurring hydrocarbon feedstock before it enters the hydrolysis zone and thus prevents its degradation. The naturally occurring hydrocarbon feedstock can then be introduced into the hydrolysis reaction zone at a temperature sufficient to ensure its fluidity, for example from 50°C to 250°C.

[0104] Advantageously, the amount of diluent introduced into the hydrolysis zone may represent 0.5 to 150% by mass, preferably 5 to 100% by mass, more preferably 5 to 40% by mass, even more preferably 10 to 20% by mass, of the total feedstock introduced into the hydrolysis zone, or in any interval defined by two of these limits. This total feedstock corresponds to the total feedstock to be treated entering the hydrolysis zone and consists of the hydrocarbon feedstock of natural origin alone or in a mixture with a liquefaction oil of a feedstock hydrocarbon selected from a biomass oil and a plastic oil, as previously described.

[0105] In one embodiment of the invention, it is also possible to introduce into said hydrolysis zone at least one liquefaction oil of a hydrocarbon feedstock chosen from a biomass oil and a plastics oil, the at least one liquefaction oil of an introduced hydrocarbon feedstock representing at most 10% by mass of the hydrocarbon feedstock of natural origin introduced into said hydrolysis zone, for example from 0.5 to 10% by mass, more preferably from 0.5 to 5% by mass. This can make it possible to incorporate more components of renewable and / or natural origin, and possibly to add aromatic compounds. This can also make it possible to eliminate during hydrolysis at least some of the impurities present in the liquefaction oil, in particular metallic impurities.

[0106] The first effluent produced by the hydrolysis pretreatment process comprises a naturally occurring component enriched in free fatty acids, typically containing at least 10% by mass of free fatty acids. It generally also contains fatty acid esters, typically in a content of at most 90% by mass.

[0107] The hydrolysis may be partial. In this case, the content of free fatty acids formed may then be limited, for example to at most 20% by mass, the content of fatty acid esters being, for example, at most 80% by mass. Partial hydrolysis may be achieved at moderate temperatures (temperatures close to the lower limit of the above-mentioned ranges, and generally at low pressure) and / or by reducing the reaction time.

[0108] Hydrolysis can be complete. In this case, the content of free fatty acids formed can then be high, for example of the order of 60% by mass. Complete hydrolysis can be achieved at high temperatures (temperatures close to the upper limit of the above-mentioned ranges, generally at high pressure) and / or by increasing the reaction time. In this case, the naturally occurring component of the effluent no longer contains fatty acid esters.

[0109] Hydrolysis can also be carried out in the presence of a catalyst.

[0110] The catalysts that accelerate the hydrolysis reaction are acids, such as sulfuric acid, acids with an organic chain containing a sulfonic group, choric acid. Other heterogeneous catalysts that accelerate the hydrolysis reaction are zinc-based catalysts. Non-exclusively, the catalyst used in the process according to the invention is a solid containing zinc oxide, at least one solid solution of general formula ZnxAhO^+x), and in the presence of at least one heterogeneous catalyst based on a silicic, aluminum or titanium solid containing zinc.

[0111] B. Process for manufacturing hydrocarbon fluids

[0112] The hydrolysis pretreatment process according to the invention is particularly advantageous when it is integrated into a process for manufacturing hydrocarbon fluids from a hydrocarbon feedstock of natural origin containing fatty acid esters and a hydrocarbon feedstock of fossil origin.

[0113] Thus, the invention also relates to a process for manufacturing hydrocarbon fluids from a hydrocarbon feedstock of natural origin containing fatty acid esters as previously defined, and a hydrocarbon feedstock of fossil origin. This process is thus a coprocessing process.

[0114] Hydrocarbon charge of fossil origin

[0115] The fossil fuel feedstock used in the coprocessing process comprises fossil fuels.

[0116] In one embodiment, the fossil-based hydrocarbon feedstock may consist of fossil-based hydrocarbons. In this case, it does not include components of renewable origin.

[0117] Hydrocarbons of fossil origin that can be used in the process can advantageously be chosen from naphtha cuts, diesel cuts, kerosene cuts and distillate cuts, originating in particular from the distillation of crude oil.

[0118] A fossil naphtha cut typically has boiling points ranging from 15°C to 220°C. It typically has, according to ASTM D86-12, an initial boiling point of 15°C to 42°C and a final boiling point less than or equal to 220°C. Such a naphtha cut generally comes from the direct distillation of crude oil or from fractionation after the hydrotreatment and / or hydroisomerization and / or hydrocracking step and typically comprises C5-C12 compounds.

[0119] A fossil fuel gas oil cut typically has boiling points ranging from 180°C to 360°C. It typically has, according to ASTM D86-12, an initial boiling point of 180 to 240°C and a final boiling point less than or equal to 360°C. Such a gas oil cut generally comes from the direct distillation of crude oil or from fractionation after the hydrotreatment and / or hydroisomerization and / or hydrocracking step and typically comprises C13-C25 compounds.

[0120] A fossil-based kerosene cut typically has boiling points ranging from 130 °C to 300 °C. It typically has, according to ASTM D86-12, an initial boiling point of 130 to 160 °C and a final boiling point of 220 °C to 300 °C. Such a kerosene cut generally comes from the direct distillation of crude oil or from fractionation after the hydrotreatment and / or hydroisomerization and / or hydrocracking step and typically comprises C9-C15 compounds.

[0121] Distillate cuts of fossil origin typically have boiling points ranging from 375 to 600 °C. They typically have, according to ASTM D86-12, an initial boiling point of 375 to 450 °C and a final boiling point of 500 °C to 600 °C. Such distillate cuts generally come from the vacuum distillation of an atmospheric residue of crude oil, also called vacuum distillates, and typically include C20-C55 compounds.

[0122] In the context of hydrotreatment, the hydrocarbons of fossil origin are advantageously a kerosene cut or a mixture of kerosene cuts, preferably originating from the direct distillation of crude oil.

[0123] In the context of hydrocracking, the hydrocarbons of fossil origin are advantageously one or more distillate cuts, preferably originating from the direct distillation of crude oil.

[0124] In the context of hydrodesulfurization, the hydrocarbons of fossil origin are advantageously one or more kerosene cuts or one or more diesel cuts, preferably originating from the direct distillation of crude oil.

[0125] In the context of hydroisomerization, the hydrocarbons of fossil origin are advantageously one or more kerosene or diesel cuts.

[0126] Step a) hydrolysis

[0127] According to the invention, step a) of pretreatment by hydrolysis is carried out according to the hydrolysis pretreatment method of the present invention, the diluent introduced into the hydrolysis zone being formed from a portion of the hydroconverted effluent from step c) and / or a portion of the hydroconverted liquid fraction from step d) of the manufacturing process. In particular, these recycled portions can be taken directly from the outlet of the steps concerned and sent directly, in particular without intermediate cooling, to the hydrolysis step, in order to limit the heating to be applied to the hydrocarbon feedstock of natural origin before it enters step a) and thus to limit its degradation.

[0128] Optional step b) of separation and / or purification

[0129] The first effluent from the hydrolysis stage may still contain alcohol residues, inorganic impurities and / or water.

[0130] The manufacturing process according to the invention may then comprise an optional step b) of treatment, in particular separation and / or purification, of the first effluent enriched in free fatty acids, and optionally containing fatty acid esters, produced during step a) during which the free fatty acids are separated from the alcohols, inorganic impurities and / or residual water present in this first effluent. This treatment step b) can be carried out in a treatment zone comprising one or more separation and / or purification zones.

[0131] This treatment zone may comprise, for example, a separation tank making it possible to separate at least a portion of an aqueous phase containing the residual alcohols as well as the contaminants dissolved in the water initially contained in the first effluent, and the first purified effluent containing the free fatty acids.

[0132] The treatment zone may include a water wash zone, preferably implemented in a contactor, typically upstream of the separation tank when present.

[0133] Preferably, the treatment zone may comprise, for example, a contactor for washing the first effluent with water followed by a separation tank for separating at least a portion of an aqueous phase containing the residual alcohols as well as the contaminants dissolved in the water initially contained in the first effluent, and the first purified effluent containing the free fatty acids.

[0134] The treatment zone may include a guard bed purification zone, typically downstream of the separation tank when present, making it possible to retain inorganic impurities present in the effluent.

[0135] This optional purification step may also include a demetallation step (H DM) implemented upstream of the hydroconversion or at the top of the latter, typically downstream of the separation tank. This demetallation may be carried out in one or more guard reactors containing a suitable catalyst located upstream of the hydroconversion or by means of one or more guard beds positioned at the entrance to the hydroconversion zone.

[0136] Step c) of hydroconversion

[0137] During this step, the hydrocarbon feedstock of fossil origin and the first effluent leaving step a), or the first purified effluent leaving step b), are brought into contact with dihydrogen in a hydroconversion zone in the presence of at least one catalyst under conditions suitable for transforming the free fatty acids of the first effluent into paraffins and for carrying out a hydroconversion of the feedstock of fossil origin. This hydroconversion step produces a hydroconverted effluent which thus comprises components of fossil origin and components of natural origin. During this step, the free fatty acids, and optionally the fatty acid esters, present in the first effluent are converted into paraffins.

[0138] The fossil-based hydrocarbon feedstock and the first effluent, optionally purified, can be introduced into the hydroconversion zone separately or as a mixture.

[0139] The hydroconversion step is carried out in a hydroconversion zone comprising one or more reactors. Any type of reactor normally used for this type of reaction may be used, for example a fixed-bed reactor, an ebullated-bed reactor, a slurry reactor, etc. The hydroconversion zone may in particular comprise one or more catalysts promoting the hydroconversion step.

[0140] The quantity of first effluent, purified or not, introduced into the hydroconversion zone can advantageously represent from 0.5 to 90% by mass, more preferably from 0.5 to 50% by mass, more preferably from 0.5 to 25% by mass of the total feed (first effluent and hydrocarbon feed of fossil origin) introduced into the hydroconversion zone.

[0141] This hydroconversion step may comprise, or consist of, a hydrodesulfurization step, a hydroisomerization step, a hydrocracking step, a hydrotreatment step.

[0142] The catalyst may be chosen from (i) oxides, phosphides or sulfides of Ni, Mo, W, Co or mixtures of NiW, NiMo, CoMo, NiCoW, NiCoMo, NiMoW and CoMoW, (ii) metals or mixtures of metal alloys from group 10 and group 11 of the periodic table, (iii) basic oxides such as alkali metal oxides, alkaline earth oxides, lanthanide oxides, zinc oxide, spinels, perovskites, calcium silicates.

[0143] The catalyst may have a supported or unsupported catalytic active phase.

[0144] When the catalyst comprises a support for the catalytic active phase, it is preferable that the support has a high specific surface area. In one embodiment, the specific surface area must be at least 5 m2 / g, preferably at least 50 m2 / g and more preferably at least 75 m2 / g, this specific surface area can be measured by methods known in the art such as the BET method where nitrogen adsorption makes it possible to estimate the specific surface area of ​​the solid material.

[0145] It is also preferable that the support of the catalytic active phase has a low acidity, preferably neutral or basic, in order to avoid hydroisomerization reactions which would give rise to branched paraffins and cracking at high temperature and pressure in the presence of dihydrogen.

[0146] The hydroconverted effluent leaving the hydroconversion zone typically comprises a liquid portion and a gaseous portion. The liquid portion essentially comprises a mixture of n-paraffins, typically comprising 5 to 60 carbon atoms. The gaseous portion comprises H2, H2S, CO2, and possibly CO, NH3. The hydrotreated effluent also contains water.

[0147] In one embodiment, a portion of the entire hydroconverted effluent leaving step c) may be sent, before any separation, to the hydrolysis step as a diluent. This may make it possible to keep the dihydrogen present in the effluent in solution, and thus limit the quantity of dihydrogen that must be separated during separation step d). This may make it possible to promote the hydroconversion reaction.

[0148] Alternatively or in combination, a portion of the entire hydroconverted effluent leaving step c) may be sent, before any separation, to the hydrolysis step, making it possible to manage the exothermicity of this step and to supply more dihydrogen in dissolved form to the hydroconversion zone.

[0149] In addition, during this hydroconversion step, the fatty acid esters and free fatty acids contained in the first effluent (purified or not) are transformed into paraffins, in particular into linear or substantially linear paraffins, via hydrodeoxygenation and / or decarboxylation and / or decarbonylation reactions:

[0150] - hydrodeoxygenation (HDO), removes oxygen from the treated oils and leads to the formation of linear paraffins while preserving the number of carbons of the initial fatty chains and is accompanied by the formation of water and propane, this reaction can be carried out on fatty acid esters, free fatty acids or their mixtures;

[0151] - decarboxylation and / or decarbonylation (COD X ), leads to the formation of paraffins with one carbon atom less than the initial fatty chain and is accompanied by the formation of carbon oxides (CO and CO2) and propane, this reaction can be carried out on glycerides, any esters or with free fatty acids.

[0152] The hydroconverted effluent thus comprises a hydroconverted liquid fraction enriched with paraffins of natural origin and a fraction of non-condensable components. Paraffins of natural origin typically comprise 9 to 24 carbon atoms, depending on the biological feedstock used.

[0153] The hydroconversion step can be carried out at a temperature of 100 to 550 °C in the presence of dihydrogen at pressures ranging from 0.01 to 25 MPa. The ratio of dihydrogen to feedstock can be from 50 to 3000 Nl / I.

[0154] The hydroconversion step can be implemented under hydrocracking conditions, in particular to treat a hydrocarbon feedstock of heavy fossil origin, such as a distillate cut.

[0155] The reactions carried out under hydrocracking conditions are typically hydrotreatment reactions (hydrodesulfurization, denitrogenation, catalytic hydrogenation) and the hydrocracking reactions themselves (cleavage of CC bonds) or CC rearrangement (hydroisomerization).

[0156] Typical hydrocracking conditions include a temperature of 250 to 480°C, a hydrogen partial pressure of 1.5 to 25 MPa abs., and an hourly volumetric flow rate of 0.1 to 10 h'. 1 .

[0157] Typical hydrocracking conditions generally include a dihydrogen content of 100 to 3000 Nm3 / m3 of feed.

[0158] The catalyst used is a typical hydrocracking catalyst. It is generally a bifunctional catalyst comprising a hydro-dehydrogenating function and an acid function.

[0159] A usable hydrocracking catalyst comprises, for example, a support chosen from halogenated aluminas, combinations of boron and aluminum oxides, amorphous silica-aluminas and zeolites and a hydro-dehydrogenating function comprising at least one metal from group 6 chosen from chromium, molybdenum and tungsten, alone or as a mixture, and / or at least one metal from groups 8, 9, 10 chosen from iron, cobalt, nickel, ruthenium, rhodium, palladium and platinum.

[0160] The hydroconversion stage can be implemented under hydrodesulfurization conditions, in particular to treat a hydrocarbon feedstock of fossil origin such as diesel or kerosene cut.

[0161] Reactions carried out under hydrodesulfurization conditions are typically hydrotreatment reactions (hydrodesulfurization, denitrogenation, catalytic hydrogenation). Hydrodesulfurization reactions are characterized by the breaking of CS bonds of sulfur derivatives contained in petroleum, namely mercaptans, sulfides and thiophene compounds.

[0162] Typical hydrodesulfurization conditions include a temperature of 320 to 420 °C, preferably 320 to 400 °C, a hydrogen partial pressure of 1 to 15 MPa abs. and an hourly volumetric flow rate of 0.3 to 5 h' 1 .

[0163] Typical hydrodesulfurization conditions generally include a dihydrogen rate of 100 to 2000 Nm3 / m3 of feed.

[0164] A conventional catalyst promoting hydrodesulfurization reactions may be used. An example of a catalyst that can be used comprises a catalyst based on metal oxides selected from oxides of metals from groups 6 (Mo, W, etc.) and 8-10 (Co, Ni, Pt, Pd, Ru, Rh, etc.) supported on a support selected from alumina, silica-alumina, zeolite, ferrierite, phosphated alumina, phosphated silica-alumina, etc., preferably oxides, phosphides or sulfides of Ni, Mo, W, Co, NiW, CoMo, NiMo, NiCoMo, NiWMo, NiCoW, CoWMo, or PtPd, or a mixture of two or more of these. The most widespread industrial catalysts are of the Co-Mo (cobalt-molybdenum) and Ni-Mo (nickel-molybdenum) type on alumina support.

[0165] The hydroconversion step can be implemented under hydrotreatment conditions, in particular to treat a hydrocarbon feedstock of fossil origin such as kerosene cut.

[0166] Typical hydroprocessing conditions include a temperature of 250 to 380 °C, preferably 280 to 340 °C, a hydrogen partial pressure of 1 to 15 MPa.

[0167] Typically, an hourly volumetric velocity of the liquid of 0.2 to 9 hr-1, preferably 0.5 to 7 hr-1, and more preferably 0.8 to 1.8 hr-1, and a dihydrogen ratio of 50 to 1500 Nm3 / m3 of charge, preferably 120 to 250 Nm3 / m3 and more preferably 120 to 200 Nm3 / m3 may be provided.

[0168] Typical hydrotreating conditions generally include a dihydrogen rate of 120 to 1800 Nm3 / m3 of feed.

[0169] The hydrotreatment catalyst is a conventional hydrotreatment catalyst. Conventional hydrotreatment catalysts include, in particular, an active metal compound such as nickel, platinum, palladium, rhenium, rhodium, nickel tungstate, nickel molybdenate, molybdenum, cobalt molybdenate, nickel molybdenate, this metal compound being able to be deposited or not on a support. This support can generally include oxides such as silicas, aluminas, aluminosilicates (in particular zeolites), titanium oxides, or carbon oxides, molecular sieves, salts or alkaline earth metals. When a support is present, it advantageously has a specific surface area varying from 100 to 550 m2 / g, preferably from 150 to 300 m2 / g.

[0170] Advantageously, the catalyst may comprise at least two or three oxides, phosphides or sulfides of metals from groups 6, 9, 10, 11 of the periodic table of elements, preferably at least two or three oxides, phosphides or sulfides of metals such as Ni, Mo, W, Co, NiW, CoMo, NiMo, NiCoMo, NiWMo NiCoW or CoWMo, preferably on an alumina support.

[0171] The hydroconversion zone may advantageously comprise at least one catalytic bed containing at least in part a catalyst with an isomerizing and / or hydrocracking function, based on oxides, phosphides or sulfides of Ni, Mo, W, Co, NiW, CoMo, NiMo, NiCoMo, NiWMo, NiCoW or CoWMo or precious metals such as Pt, Pd or mixtures, and preferably oxides, phosphides or sulfides of Ni, Mo, W, Co, NiW, CoMo, NiMo, NiCoMo, NiWMo NiCoW or CoWMo on an acid support. Catalytic beds containing oxides, phosphides or sulfides of Ni, Mo, W, Co, NiW, CoMo, NiMo, NiCoMo, NiWMo NiCoW or CoWMo or precious metals such as Pt, Pd or mixtures on acidic support have the advantage of promoting isomerization reactions, which can improve, i.e. reduce, the cloud point of the finished product. This type of catalyst with an isomerizing function will advantageously be placed just before leaving the hydroconversion zone.The presence of a catalyst with an isomerizing function is particularly advantageous when the hydroconversion step is a hydrodesulfurization step.

[0172] The hydroconversion step can involve hydroisomerization and / or hydrocracking.

[0173] Suitable hydroisomerization and / or hydrocracking catalysts used in hydroisomerization and / or hydrocracking processes are typically all of the bifunctional type combining an acid function with a (de)hydrogenating function.

[0174] The acid function is typically provided by a support (amorphous or crystalline) whose specific surfaces are generally between 100 and 700 m2 / g and which has a surface acidity, such as halogenated aluminas (in particular chlorinated or fluorinated), sulfated, phosphated, aluminas, aluminas (possibly containing boron), amorphous silica-aluminas, amorphous silica-aluminas-titaniums, phosphated alumina or phosphated silica-alumina, sulfated zirconias, zirconia-tungsten and zeolites or their mixtures. The acidity can be measured by methods well known to those skilled in the art. It can, for example, be measured by temperature-programmed desorption (TPD) with ammonia, by infrared measurement of the absorbed molecules (pyridine, CO . . .), by a catalytic cracking test or by hydroconversion using a model molecule.

[0175] Hydroisomerization catalysts have a weak acid function, preferably halogenated aluminas (in particular sulfated, phosphated, chlorinated or fluorinated), aluminas (possibly containing boron), amorphous silica-aluminas, phosphated alumina or phosphated silica-alumina and amorphous silica-aluminas-titaniums.

[0176] Hydrocracking catalysts have a strong acid function, preferably sulfated zirconias, tungsten zirconias and zeolites or their mixtures.

[0177] The (de)hydrogenation function is typically performed either by one or more metals from group 6 of the periodic table of elements, or by a combination of at least one metal from group 6 of the periodic table and at least one metal from groups 8, 9, 10.

[0178] The distance between the two functions, acid and (de)hydrogenating, is one of the key parameters governing the activity and selectivity of the catalyst.

[0179] A weak acid function and a strong (de)hydrogenating function give low activity catalysts, generally requiring a high temperature (greater than or equal to 390-400°C), and long residence times or low hourly space velocity (the WH expressed as liquid volume of feedstock to be treated per unit volume of catalyst and per hour is generally less than or equal to 2), but have very good selectivity for middle distillates (jet fuels and gas oils). Generally, the term "middle distillates" as used in the present invention applies to one or more fractions whose initial boiling point is at least 150°C and whose end point is generally less than about 350°C, preferably less than 370°C.

[0180] Conversely, a strong acid function and a weak (de)hydrogenating function give catalysts that are active, but have lower selectivity for middle distillates and the result is more cracked hydrocarbons in the naphtha and jet fuel range.

[0181] A conventional type of hydroisomerization catalyst is based on amorphous supports that are moderately acidic, such as silica-aluminas. These systems are used to maximize middle distillates with good cold flow properties.

[0182] One type of conventional hydrocracking catalyst is based on crystalline supports such as zeolites and sulfated zirconias, which are strongly acidic, such as zeolites. These systems are used to reduce the number of carbons in the chain and have good cold flow properties. Hydrocracking produces non-condensable gases, naphtha, kerosene, and diesel.

[0183] Catalysts and conditions for hydroisomerization and / or hydrocracking are well known in the art.

[0184] Hydrocarbons are contacted with a hydroisomerization and / or hydrocracking catalyst in the presence of dihydrogen under hydroisomerization and / or hydrocracking conditions to isomerize and / or hydrocrack normal paraffins into branched and / or shorter paraffins. The hydroisomerization and / or hydrocracking of the paraffinic product may be accomplished in any manner known in the art or by using any suitable catalyst known in the art.

[0185] The acidic support material can be amorphous or crystalline. Suitable support materials include amorphous alumina, amorphous silica-alumina, amorphous silica borate, amorphous silica-alumina-titanium, zeolites or modified zeolites having the following structures: ferrierite, zeolite beta, zeolite Y, zeolite mordenite and molecular sieves of the type 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-38, ZSM-48, ZSM-50, ZSM-57, theta-1, EU-1, EU-13, ISI-1, KZ-2, ISI-4 and KZ-1, MeAPO-11, MeAPO-31, MeAPO-41, MeAPSO-11, MeAPSO-31, MeAPSO-41, MeAPSO-46, ELAPO-11, ELAPO-31, ELAPO-41, ELAPSO-11, ELAPSO-31, ELAPSO-41, each of which may be used alone or in combination.

[0186] The production of the bifunctional hydroisomerization and / or hydrocracking catalyst can be carried out by any method known in the art. The (de)hydrogenation function can be added to the acidic support by impregnation with metal-containing solutions, by ion exchange and by mixing.

[0187] During a hydroisomerization reaction, hydrocracking side reactions may occur. Similarly, during a hydrocracking reaction, hydroisomerization may occur. A person skilled in the art will be able to choose conditions Suitable for treating the effluent under hydroisomerization conditions, respectively under hydrocracking conditions, namely conditions under which hydroisomerization reactions, respectively hydrocracking reactions, predominantly occur.

[0188] Separation step d)

[0189] The hydroconverted effluent from step c) is subjected, in part or in whole, before being sent to step d) or e), to a separation step d) in which the non-condensable components such as propane, CO2, CO, methane, dihydrogen and vaporized water are separated from the liquid fraction.

[0190] In one embodiment, the dihydrogen may be separated from the other non-condensable components and returned in part or in whole to the hydrolysis step a) to be dissolved in the reaction mixture. This may serve to promote the hydroconversion reaction of step c). Alternatively or in combination, the dihydrogen may be separated and returned, in part or in whole, to the inlet of step c).

[0191] In one embodiment, the effluent from step c) can thus be separated into:

[0192] - a gas flow containing H2, H2S, CO2, and possibly small quantities of CO and NH3,

[0193] - water,

[0194] - a hydroconverted liquid fraction.

[0195] This separation can be implemented in a high pressure separator.

[0196] The gas stream may undergo further treatment to separate the dihydrogen from other gases for reuse in the process.

[0197] The liquid fraction can be sent to a steam stripping column to separate the gases still present in the liquid fraction.

[0198] According to the invention, a part of the separated liquid fraction can serve as a diluent during the hydrolysis step.

[0199] The remaining liquid fraction may then be fractionated into at least one fraction chosen from a naphtha fraction, a diesel fraction and a kerosene fraction, for example during a subsequent fractionation step e).

[0200] This separation step d), implemented in a separation zone, can be a high-pressure separation, a flash separation and / or be carried out in a stripping section. Depending on the operating conditions, part of the remaining water can be condensed and removed in this step by decantation or drainage, for example in a high-pressure separator. The flash separation and the removal of liquid water can be carried out simultaneously or not.

[0201] In particular, a separator tank may be provided to separate the water, gases and a liquid organic phase, the latter then being sent to a stripping section to remove the light hydrocarbons. The gases can be sent to a treatment section, for example to amines, to separate the dihydrogen from the other gaseous components.

[0202] The water produced in the hydroconversion can be used in step a) of hydrolysis or in step b) of purification and thus reduce the net need for water to carry out this step a) and / or b).

[0203] Step e) of splitting

[0204] In one embodiment of the invention, the process for manufacturing hydrocarbon fluids may further comprise a fractionation step e) in which the effluent from step d) is separated into at least one fraction chosen from a naphtha fraction, a diesel fraction and a kerosene fraction.

[0205] The effluent leaving step d) may undergo fractionation, for example by adding a separation column, for example a distillation column, or by lateral withdrawal.

[0206] This fractionation makes it possible to recover at least one fraction chosen from a naphtha fraction, a diesel fraction and a kerosene fraction. This fractionation step can also make it possible to separate non-condensable fractions and / or unreacted dihydrogen, which can optionally be sent to the inlet of step c).

[0207] The recovered naphtha fraction preferably has an initial boiling point of 30°C and a final boiling point of 80°C to 220°C. This fraction can be used as fuel for combustion engines, particularly without the addition of other components such as esters. This fraction can be used as feedstock for a steam cracker, particularly to produce olefins such as ethylene and propylene.

[0208] The recovered diesel fraction preferably has an initial boiling point of 180 to 240°C and a final boiling point less than or equal to 360°C. This fraction can be used as fuel for diesel engines, in particular without the addition of other components such as esters.

[0209] The recovered kerosene fraction preferably has a final boiling point below 300°C. The initial boiling point can be 120 to 185°C. The kerosene fraction can be used as jet fuel, especially without the addition of other components such as esters.

[0210] In particular, the cutting points of the recovered fractions can be adapted in order to obtain products meeting specific specifications, in particular without having to add other components such as esters.

[0211] In one embodiment of the invention, a portion of one or more of these fractions may be used as a diluent during the hydrolysis step. Detailed description of the figures

[0212] Other features and advantages of the invention will emerge from reading the description given below of a particular embodiment of the invention, given for informational purposes but not as a limitation, with reference to the appended drawings in which:

[0213] [Fig.1] schematically represents a unit for manufacturing hydrocarbon fluids according to one embodiment of the invention.

[0214] Figure 1 represents a hydrocarbon fluid manufacturing unit 100 comprising a hydrolysis zone 10, a hydroconversion zone 20, a separation zone 30 and a fractionation zone 40. Depending on the objective sought, the fractionation zone 40 can be omitted.

[0215] The hydrolysis zone 10 may be a co-current mixer reactor or a counter-current reactor. The feedstock to be treated enters the hydrolysis zone 10 via a first pipe 1. This feedstock is a naturally occurring hydrocarbon feedstock containing fatty acid esters as previously defined, and typically containing fatty acid triglycerides and / or fatty acid alkyl esters. This feedstock may be introduced at a temperature above 150°C but preferably below 250°C.

[0216] Via the same line 1 or another line 2, another feedstock can optionally be co-processed. This other feedstock is, for example, a liquefaction oil from a hydrocarbon feedstock, namely a biomass oil and / or a plastics oil.

[0217] Water, typically at a temperature of at least 250°C, is introduced into the hydrolysis zone 10 via a line 3. In the example, an optional line 4 allows steam to be introduced.

[0218] At the outlet of the hydrolysis zone 10, a first effluent enriched in free fatty acids formed during the hydrolysis is recovered via a pipe 5 and a second effluent which is an aqueous phase containing the majority of the alcohols produced during the hydrolysis via a pipe 6. This aqueous phase also contains a majority of the pollutants initially contained in the hydrocarbon feedstock of natural origin.

[0219] The organic phase is then sent to a hydroconversion zone 20 of a hydrocarbon feedstock of fossil origin to be hydrotreated there in coprocessing with the latter and to produce a hydroconverted effluent discharged via line 7.

[0220] The hydroconversion zone 20 thus comprises a pipe 8 for supplying dihydrogen, a pipe 9 for introducing the feedstock of fossil origin and one or more catalytic beds. The hydroconversion zone 20 may comprise one or more reactors operated in series, or in parallel or both.

[0221] In the example shown, line 9 is connected to line 5 before it enters the hydroconversion zone 20, so that the two feeds enter the latter as a mixture. However, provision could be made for these lines 5 and 9 to each be connected directly to the hydroconversion zone.

[0222] The hydroconverted effluent comprises a liquid fraction enriched in paraffins of natural origin, and a fraction of non-condensable components.

[0223] According to one embodiment of the invention, a portion of the hydroconverted effluent may be brought via a pipe 7a into the hydrolysis zone 10. Due to this incorporation, the effluent enriched in free fatty acids leaving the hydrolysis zone also contains components of fossil origin. Thus, the supply of hydroconverted effluent allows a dilution of the hydrocarbon feedstock of natural origin in the hydrolysis zone 10 as well as a dilution of the free fatty acids produced during the hydrolysis and evacuated via the pipe 5.

[0224] Furthermore, the hydroconverted effluent leaving the hydroconversion zone 20, in particular directly, without intermediate cooling, is at a temperature of at least 250°C, so that its introduction into the hydrolysis zone 10 provides part of the heating necessary for the hydrolysis reaction, improving the thermal integration of the unit.

[0225] It will be noted that the hydroconverted effluent can be sent directly to the hydrolysis zone 10, without having undergone prior degassing, so that it contains dihydrogen which has not reacted and which dissolves in the feedstock and is then found in the first effluent 5 then entering the hydroconversion zone 20. This makes it possible to reduce the consumption of dihydrogen in this zone.

[0226] In the example shown, the unit 100 also comprises an optional separator tank 11 located on the pipe 5 for discharging the first effluent enriched in free fatty acids. This separator tank makes it possible to condense a portion of the water contained in the first effluent, as well as the alcohols and pollutants present in this water, discharged via a pipe 12. It is then a first effluent enriched in free fatty acids and having a reduced content of water, alcohols and pollutants which enters the hydroconversion zone 20.

[0227] In the embodiment shown, the hydroconversion zone 20 further has at least one catalytic bed 21 dedicated to demetallation (guard bed) and making it possible to eliminate chlorine, metals and silicon. Isolated guard reactors, lead-lag, in series and / or in parallel can be envisaged depending on the nature and quantity of contaminants in the flow to be treated. Depending on the pollutant content of the first effluent, one or more guard beds can be provided. It is also possible not to provide a guard bed.

[0228] In the embodiment shown, the hydroconversion zone 20 also has a catalytic isomerization zone 22 comprising at least one isomerizing catalytic bed in order to carry out an isomerization of at least a portion of the n-paraffins. This catalytic zone is preferably located in the immediate vicinity of the outlet of the hydroconversion zone so that it is the last catalytic zone crossed by the effluent.

[0229] Note that depending on the fossil fuel load treated, the composition of the first effluent and the desired objective, the guard bed and / or the catalytic isomerization zone may or may not be present.

[0230] The separator tank 11 and / or the guard bed(s) 21 are part of an optional purification zone 15 implementing the optional purification treatment step b),

[0231] At the outlet of the hydroconversion zone 20, the hydroconverted effluent discharged via the pipe 7 comprises a hydroconverted liquid fraction enriched with paraffins of natural origin and a fraction of incondensable components. In this embodiment, the hydroconverted effluent is sent to a separation zone 30 comprising a separator tank 31 and a stripping column 32. The separator tank 31 makes it possible to separate the water present in the effluent via a pipe 33 and incondensable gases (G) via a pipe 34. Note that the water recovered via the pipe 33 could be returned to the hydrolysis zone 10, optionally after having undergone treatment in order to reduce its acidity.

[0232] The liquid organic phase leaves the flask 31 via a pipe 35 to enter the stripping column 32 into which steam is introduced via a pipe 36. The gases are evacuated from the stripping column 32 via a pipe 37 and the liquid fraction is recovered at the bottom of the column 32 via the pipe 38.

[0233] A portion of this liquid fraction is brought to a fractionation zone 40 via the pipe 38b, another portion being returned upstream of the hydrolysis zone 10 via the pipe 38a connected to the pipe 1. Note that the pipe 38a could open directly into the hydrolysis zone 10 via a dedicated inlet.

[0234] Depending on the desired objective, it is also possible to take a portion of the effluent circulating in pipes 7 or 35 and return it upstream of the hydrolysis zone 10 to be mixed with the hydrocarbon feed circulating in pipe 1 (via pipes 7a or 35a) or to return it directly to the hydrolysis zone, via dedicated inlets.

[0235] The fractionation zone 40, for example a distillation column, makes it possible to separate the effluent entering via the pipe 38b into several streams discharged via the pipes 41, 42, 43, typically a naphtha fraction, a kerosene fraction and a diesel fraction. A portion of one or more of these fractions may be returned to the hydrolysis zone 10 via the pipe 44, to be mixed there with the hydrocarbon feedstock of natural origin either before it enters the hydrolysis zone or after it enters the latter.

[0236] Examples of temperatures and pressures of circulating effluents are given in Figure 1. It can be seen that high temperature flows are returned to the hydrolysis zone without having undergone any cooling other than that resulting from their passage through the existing equipment, for better thermal integration of the entire unit.

[0237] Regardless of the embodiment, the diluent may be introduced into the hydrolysis zone 10 via the first inlet pipe 1, via the second inlet pipe 2, or via an additional dedicated inlet (not shown).

Claims

CLAIMS 1. A method for pretreatment by hydrolysis of a hydrocarbon feedstock of natural origin containing fatty acid esters, in which: said hydrocarbon feedstock of natural origin is brought into contact with water in a hydrolysis zone (10) to produce a first effluent enriched in free fatty acids, optionally containing fatty acid esters, and a second effluent rich in alcohol and water, and a diluent is introduced into the hydrolysis zone, said method being characterized in that: said diluent is a hydrocarbon effluent comprising a component of fossil origin, this hydrocarbon effluent comprises an effluent from a hydroconversion treatment of a hydrocarbon feedstock of fossil origin mixed with a hydrocarbon feedstock comprising a hydrolyzed component of natural origin, and / or a liquid fraction of this effluent, and the diluent is introduced into the hydrolysis zone at a temperature of 200°C to 350°C.

2. Pretreatment process according to claim 1, characterized in that the liquid fraction of hydrocarbon effluent is chosen from a naphtha fraction, a kerosene fraction, a diesel fraction.

3. Pretreatment method according to claim 1 or 2, characterized in that the quantity of diluent introduced into the hydrolysis zone represents 0.5 to 150% by mass of the total load to be treated introduced into said zone.

4. Pretreatment process according to any one of claims 1 to 3, characterized in that the hydrocarbon feedstock of natural origin containing fatty acid esters comprises an oil of natural origin, an esterified oil of natural origin or their mixtures.

5. Pretreatment method according to any one of claims 1 to 4, characterized in that at least one liquefaction oil of a hydrocarbon feedstock chosen from a biomass oil and a plastics oil is also introduced into said hydrolysis zone, the at least one liquefaction oil of a hydrocarbon feedstock representing at most 10% by mass of the hydrocarbon feedstock of natural origin introduced into said hydrolysis zone.

6. Pretreatment process according to any one of claims 1 to 5, characterized in that the hydrolysis is carried out under one or more of the following conditions: a temperature of 130 to 350°C, a pressure of 7 to 100 barg, a water / natural hydrocarbon feedstock mass ratio of 0.1 to 2.

0.

7. Process for manufacturing hydrocarbon fluids from a hydrocarbon feedstock of natural origin containing fatty acid esters and a hydrocarbon feedstock of fossil origin, said process comprising at least: a) a pretreatment step by hydrolysis of the hydrocarbon feedstock of natural origin in which said hydrocarbon feedstock of natural origin is brought into contact with water in a hydrolysis zone (10) to produce a first effluent enriched in free fatty acids, optionally containing fatty acid esters, and a second effluent rich in alcohol and water, b) an optional step of separation and / or purification of the first effluent enriched in free fatty acids from step a) during which residual alcohols, inorganic impurities and / or water are removed from the first effluent to obtain a first purified effluent, c) a hydroconversion step, in which said hydrocarbon feedstock of fossil origin is brought into contact with the first effluent from step a), optionally purified in step b),with dihydrogen in a hydroconversion zone (20) in the presence of at least one catalyst under conditions suitable for carrying out a hydroconversion and forming a hydroconverted effluent comprising a hydroconverted liquid fraction and a fraction of incondensable components, d) a step of separating the hydroconverted effluent from step c) during which the fraction of incondensable components is separated from the hydroconverted liquid fraction, said process being characterized in that step a) is carried out according to the pretreatment process of any one of claims 1 to 6, said diluent introduced into the hydrolysis zone being chosen from (i) a portion of the hydroconverted effluent from step c), originating directly from step c), without intermediate cooling, (ii) a portion of the hydroconverted liquid fraction from step d), originating directly from step d), without intermediate cooling, or (iii) a mixture of (i) and (ii)., 8. A process for manufacturing hydrocarbon fluids according to claim 7 further comprising: e) a second step e) of fractionating the hydroconverted liquid fraction of step d), in which said hydroconverted liquid fraction is separated into at least one liquid fraction chosen from a naphtha fraction, a diesel fraction and a kerosene fraction, and said diluent introduced into the hydrolysis zone comprises a portion of the at least one separated liquid fraction.

9. Manufacturing method according to any one of claims 7 to 8, characterized in that the quantity of first effluent introduced into the hydroconversion zone (20) represents from 0.5 to 90% by mass, more preferably from 0.5 to 50% by mass, more preferably from 5 to 25% by mass of the total feedstock introduced into the hydroconversion zone.

10. Manufacturing method according to any one of claims 7 to 9, characterized in that at least part of the incondensable components separated in step d) are sent in the hydrolysis zone, optionally after removal of components other than dihydrogen.

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