Method for treating a tyre pyrolysis oil

Abstract

The present invention relates to a method for treating a feedstock comprising at least 5% by weight, relative to the total weight of the feedstock, of a tyre pyrolysis oil, the tyre pyrolysis oil having a sulfur content of between 2000 and 10,000 ppm by weight relative to the total weight of the oil, the method comprising: a) an optional selective hydrogenation step, b) a step of hydrogenation in the presence of hydrogen and a catalyst in order to obtain a hydrogenated effluent, c) a step of hydrotreating the hydrogenated effluent in the presence of hydrogen and a catalyst in order to obtain a hydrotreated effluent, and d) a separation step, carried out between steps b) and c) and / or after step c), the step being fed with the hydrogenated effluent from step b) and / or with the hydrotreated effluent from step c), and an aqueous solution, in order to obtain at least one gaseous effluent, an aqueous effluent and a hydrocarbon effluent.

Description

[0001] PROCESS FOR TREATING TIRE PYROLYSIS OIL

[0002] TECHNICAL FIELD

[0003] The present invention relates to the field of tire recycling. More particularly, the present invention relates to a method for treating a feedstock comprising a pyrolysis oil of which at least 5% by weight of the pyrolysis oil is derived from tires. Tire pyrolysis oils generally contain a significant sulfur content. The method makes it possible to eliminate at least in part the impurities that said feedstock may contain in relatively large quantities while reducing, by using a pyrolysis oil highly loaded with sulfur compounds, the consumption of sulfurizing agent to be added in order to maintain the catalysts in sulfide form in the catalytic stages of the method.

[0004] PRIOR TECHNIQUE

[0005] Plastics from collection and sorting channels, recycled tires, or solid recovered fuels (SRF) can undergo a pyrolysis step for recovery. Pyrolysis consists of heating, with or without a catalyst, a feedstock containing plastic and / or recycled tires and / or SRF in the absence of oxygen, leading to the formation of three main products: a liquid hydrocarbon phase at room temperature, also called pyrolysis oil, a light gas phase, also called pyrolysis gas, and a solid residue, also called char.

[0006] The liquid hydrocarbon phase, pyrolysis oil, can be recovered in a gasoline, kerosene or diesel fuel storage unit.

[0007] Another way of recovering pyrolysis oils is to use them as feedstock for a steam cracking unit in order to (re)create olefins, the latter being monomers that make up certain polymers.

[0008] However, pyrolysis oils contain impurities that are often at high levels and are incompatible with direct storage in a fuel storage unit or with steam cracking units or units located downstream of steam cracking units, in particular polymerization processes and selective hydrogenation processes. These impurities can generate operability problems, including corrosion problems (particularly due to the presence of chlorine), coking or catalytic deactivation, or even incompatibility problems in the uses of the target polymers. The presence of diolefins can also lead to instability problems in the pyrolysis oil, characterized by the formation of gums. Gums and insolubles possibly present in the pyrolysis oil can generate clogging problems in the processes.

[0009] One way to remove these impurities from pyrolysis oils is to carry out hydrotreatment (H DT) in the presence of catalysts. Such processes are described, for example, in WO2018 / 055555, WO2021 / 165178 or WO2022 / 144235.

[0010] Application WO2022 / 144235 describes a process for treating plastic pyrolysis oil aimed at reducing and / or eliminating impurities contained in the pyrolysis oil in order to obtain an effluent compatible with a steam cracker.The process comprises the following steps: a) hydrogenation of said feedstock in the presence of at least hydrogen and at least one hydrogenation catalyst at an average temperature of between 140 and 340°C, the outlet temperature of step a) being at least 15°C higher than the inlet temperature of step a), to obtain a hydrogenated effluent; b) hydrotreatment of said hydrogenated effluent in the presence of at least hydrogen and at least one hydrotreatment catalyst, to obtain a hydrotreated effluent, the average temperature of step b) being higher than the average temperature of step a); c) separation of the hydrotreated effluent in the presence of an aqueous stream, at a temperature of between 50 and 370°C, to obtain at least one gaseous effluent, one aqueous liquid effluent and one hydrocarbon liquid effluent.

[0011] One way to eliminate impurities contained in pyrolysis oils is to carry out hydrotreatment in the presence of catalysts which are active in the form of sulfides.

[0012] In the feedstock containing plastic pyrolysis oil, we generally have feedstocks that are quite low in sulfur. However, a minimum ppH2S is necessary in the hydrotreatment reactor to keep the catalysts in sulfide form and thus not reduce them. To maintain a sufficient ppH2S in the reactor and given that ex-plastic feedstocks do not contain sufficient sulfur, a sulfurizing agent is generally, or even obligatorily, added continuously, typically DMDS (dimethyl disulfide) in the feedstock. The sulfurizing agent decomposes very quickly into H2S by the action of temperature and hydrogen at the reactor inlet and therefore provides the quantity of H2S necessary to ensure a minimum and sufficient ppH2S. The contents of sulfur, oxygenated and / or nitrogenous compounds often depend on the origin of the pyrolysis oil.Thus, tire pyrolysis oils generally contain more heteroelements than plastic and / or CSR pyrolysis oils, including sulfur compounds.

[0013] The process according to the invention takes advantage in particular of the significant quantity of sulfur impurities contained in a tire pyrolysis oil by using the sulfur impurities as a sulfurizing agent in order to maintain the catalysts in sulfide form in the catalytic stages of the process. The fact of using a tire pyrolysis oil thus allows a significant minimization of the consumption of sulfurizing agent conventionally to be added, generally of the DM DS type.

[0014] SUMMARY OF THE INVENTION

[0015] More specifically, the invention relates to a method for treating a feedstock comprising at least 5% by weight of a tire pyrolysis oil relative to the total weight of the feedstock, said tire pyrolysis oil having a sulfur content of between 2000 and 10000 ppm by weight relative to the total weight of the tire pyrolysis oil, said method comprising the following steps: a) optionally a selective hydrogenation step carried out in a reaction section using at least one fixed bed reactor having n catalytic beds, n being an integer greater than or equal to 1, each comprising at least one selective hydrogenation catalyst, said selective hydrogenation reaction section being supplied at least by said feedstock and a gas stream comprising hydrogen, in the presence of at least one selective hydrogenation catalyst, at an average temperature between 100 and 280°C, a hydrogen partial pressure between 1.0 and 10.0 MPa abs.and an hourly volumetric velocity between 0.1 and 10.0 h. -1 , to obtain a selectively hydrogenated effluent; b) a hydrogenation step carried out in a hydrogenation reaction section, using at least one fixed-bed reactor having n catalytic beds, n being an integer greater than or equal to 1, each comprising at least one hydrogenation catalyst, said hydrogenation reaction section being supplied at least with said feedstock or said selectively hydrogenated effluent from step a) and a gas stream comprising hydrogen, said hydrogenation reaction section being carried out at an average temperature between 140 and 400°C, a partial pressure of hydrogen between 1.0 and 10.0 MPa abs. and an hourly volumetric flow rate between 0.1 and 10.0 h -1, to obtain a hydrogenated effluent, c) a hydrotreatment step carried out in a hydrotreatment reaction section, using at least one fixed-bed reactor having n catalytic beds, n being an integer greater than or equal to 1, each comprising at least one hydrotreatment catalyst, said hydrotreatment reaction section being fed at least by said hydrocarbon effluent from step d) when the separation step d) is carried out between steps b) and c), and / or at least by the hydrogenated effluent from step b) when the separation step d) is carried out after step c), and a gas stream comprising hydrogen, said hydrotreatment reaction section being carried out at an average temperature between 250 and 430°C, a hydrogen partial pressure between 1.0 and 10.0 MPa abs. and an hourly volumetric velocity between 0.1 and 10.0 h' 1, to obtain a hydrotreated effluent, d) a separation step, carried out between steps b) and c) and / or after step c), said step being fed with the hydrogenated effluent from step b) when separation step d) is carried out between steps b) and c), and / or with the hydrotreated effluent from step c) when separation step d) is carried out after step c), and an aqueous solution, said step being carried out in a separation section, to obtain at least one gaseous effluent, one aqueous effluent and one hydrocarbon effluent.

[0016] The present invention therefore relates to a process for purifying an oil resulting from the pyrolysis of tires, possibly supplemented with pyrolysis oil resulting from plastics and / or CSR, from at least some of its impurities, which makes it possible to hydrogenate it and thus to be able to recover it, in particular by incorporating it directly into the fuel storage unit or by making it compatible with treatment in a steam cracking unit while being able to considerably reduce the consumption of the sulfurizing agent.

[0017] Another advantage of the invention is to prevent risks of blockage and / or corrosion of the treatment unit, in which the method of the invention is implemented, the risks being exacerbated by the presence, often in significant quantities, of diolefins, metals and halogenated compounds in a pyrolysis oil. These risks of blockage and / or corrosion are notably reduced by a separation step involving washing with an aqueous solution.This washing / separation step makes it possible in particular to eliminate the ammonium chloride salts, which are formed by reaction between the chloride ions, released by the hydrogenation of the chlorinated compounds in HCl form, in particular during the hydrogenation step and then dissolution in water, and the ammonium ions, generated by the hydrogenation of the nitrogen compounds in the form of NH3 during the hydrotreatment step and / or supplied by injection of an amine when the content of chlorinated compounds is high, then dissolution in water. The high content of nitrogen compounds in a tire pyrolysis oil makes it possible to reduce or even eliminate the need to add a nitrogen compound, which presents another advantage of the invention.

[0018] The process of the invention thus makes it possible to obtain a hydrocarbon effluent from a tire pyrolysis oil freed at least in part from the impurities of the starting tire pyrolysis oil, thus limiting the operability problems, such as corrosion, coking or catalytic deactivation problems, which these impurities can cause, in particular in the steam cracking units and / or in the units located downstream of the steam cracking units.

[0019] Alternatively, the feedstock comprises plastic pyrolysis oil and / or recovered solid fuels.

[0020] According to one variant, the feedstock consists of tire pyrolysis oil and plastic pyrolysis oil(s) and / or recovered solid fuels.

[0021] According to one variant, the feedstock comprises a tire pyrolysis oil in a content of between 5 and 99% by weight and a plastics and / or CSR pyrolysis oil in a content of between 1 and 95% by weight relative to the total weight of the feedstock.

[0022] According to a variant, separation step d) comprises the following steps: d1) a separation step, fed with the hydrogenated effluent from step b) when separation step d) is carried out between steps b) and c), and / or with the hydrotreated effluent from step c) when separation step d) is carried out after step c), said step being carried out at a temperature higher than the precipitation temperature of the ammonium halides and at a pressure substantially identical to the pressure of step b) to obtain at least a first gaseous effluent and a liquid effluent, a part of which is optionally recycled, as recycled effluent, upstream of step b), d2) a separation step, fed with the first gaseous effluent and optionally at least a part of the liquid effluent from step d 1 ), and an aqueous solution,said step being carried out at a temperature lower than the precipitation temperature of the ammonium halides and at a pressure substantially identical to or lower than the pressure of step b), to obtain at least a second gaseous effluent, an aqueous effluent and a hydrocarbon effluent. According to a variant, step d1) is carried out at a temperature between 200 and 450°C and step d2) is carried out at a temperature greater than or equal to 20°C and less than 200°C.,

[0023] According to a variant, said method comprises at least one step of pretreatment of the feedstock comprising a tire pyrolysis oil, said pretreatment step being carried out upstream of step a) and / or upstream of step b) and comprises an adsorption step and / or a filtration step and / or a centrifugation step and / or a decantation step and / or an electrostatic separation step and / or a step of washing using an aqueous solution and / or a gas stripping step.

[0024] According to a variant, said process comprises a step e) of fractionation of all or part of the hydrocarbon effluent from step d) when the separation step d) is carried out after step c), and / or of all or part of the hydrotreated effluent from step c) when the separation step d) is carried out between steps b) and c), to obtain at least one gas stream, a naphtha cut and at least one middle distillate cut.

[0025] According to a variant, said method comprises a hydrocracking step f) implemented in a hydrocracking reaction section, using at least one fixed-bed reactor having n catalytic beds, n being an integer greater than or equal to 1, each comprising at least one hydrocracking catalyst, said hydrocracking reaction section being fed with at least a portion of said hydrocarbon effluent from step d) when the separation step d) is carried out after step c), and / or with at least a portion of the hydrotreated effluent from step c) when the separation step d) is carried out between steps b) and c), and / or with at least a portion of the middle distillate cut from the fractionation step e) and a gas stream comprising hydrogen, said hydrocracking reaction section being implemented at an average temperature between 250 and 450°C, a hydrogen partial pressure between 1.5 and 20.0 MPa abs.and an hourly volumetric velocity between 0.1 and 10.0 h. -1 to obtain a first hydrocracked effluent.

[0026] According to a variant, said hydrogenation catalyst of step b) comprises a support chosen from alumina, silica, silica-aluminas, magnesia, clays and their mixtures and a hydro-dehydrogenating function comprising either at least one element from group VIII and at least one element from group VIB, or at least one element from group VIII.

[0027] According to one variant, said hydrotreatment catalyst of step c) comprises a support chosen from alumina, silica, silica-aluminas, magnesia, clays and their mixtures, and a hydro-dehydrogenating function comprising at least one element from group VIII and / or at least one element from group VIB. According to a variant, at least a portion of the hydrocarbon effluent from step d) when the separation step d) is carried out after step c), and / or at least a portion of the hydrotreated effluent from step c) when the separation step d) is carried out between steps b) and c) and / or at least one of the cuts from the fractionation step e) is sent to a steam cracking step g) carried out in at least one pyrolysis furnace at a temperature of between 700 and 900°C and at a pressure of between 0.05 and 0.3 MPa relative.

[0028] According to one variant, the process comprises step a) of selective hydrogenation.

[0029] According to one variant, said selective hydrogenation catalyst of step a) comprises a support chosen from alumina, silica, silica-aluminas, magnesia, clays and mixtures thereof, and a hydro-dehydrogenating function comprising at least one element from group VIII and / or at least one element from group VIB.

[0030] The present invention also relates to the product obtained by the process according to the invention.

[0031] According to one variant, the product comprises, in relation to the total weight of the product:

[0032] - a total content of metallic elements less than or equal to 10.0 ppm by weight,

[0033] - with an iron element content of less than or equal to 200 ppb by weight, and / or

[0034] - a silicon element content less than or equal to 5.0 ppm by weight, and / or

[0035] - a sulfur content less than or equal to 100 ppm by weight, and / or

[0036] - a nitrogen content less than or equal to 100 ppm by weight, and / or

[0037] - a chlorine element content of less than or equal to 10 ppm by weight, and / or

[0038] - a mercury content less than or equal to 5 ppb by weight.

[0039] Alternatively, the product has a bio-carbon content according to ASTM D6866 of between 1 and 70% by weight.

[0040] According to the present invention, 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 precision will be provided by the present invention.

[0041] In this description, the term "include" is synonymous with (means the same as) "include" and "contain", and is inclusive or open and does not exclude other elements not mentioned. It is understood that the term "include" includes the exclusive and closed term "consist".

[0042] For the purposes of the present invention, the different parameter ranges for a given step such as pressure ranges and temperature ranges may be used alone or in combination. For example, for the purposes of the present invention, a range of preferred pressure values ​​may be combined with a range of preferred temperature values.

[0043] According to the present invention, the pressures are absolute pressures, also noted abs., and are given in absolute MPa (or MPa abs.), unless otherwise indicated.

[0044] In the following, particular and / or preferred embodiments of the invention may be described. They may be implemented separately or combined with each other, without limitation of combination when technically feasible.

[0045] In the following, 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, 81 ème edition, 2000-2001). For example, group VIII (or VI 11 B) according to the CAS classification corresponds to the metals of columns 8, 9 and 10 according to the new IIIPAC classification.

[0046] The metal content is measured by X-ray fluorescence.

[0047] DETAILED DESCRIPTION

[0048] The charge

[0049] According to the invention, the feedstock comprises at least 5% by weight of a tire pyrolysis oil having a sulfur content of between 2000 and 15000 ppm by weight relative to the total weight of the tire pyrolysis oil.

[0050] The feedstock may also include any other pyrolysis oil, including plastic pyrolysis oil and / or solid recovered fuels (SRF).

[0051] In addition, the feedstock can optionally be supplemented with a conventional petroleum feedstock and / or a feedstock from biomass conversion.

[0052] In the following text, "pyrolysis oil" means oil from the pyrolysis of plastics and / or tires and / or CSR, unless otherwise stated. Where the origin of the pyrolysis oil is important, its origin is added (e.g., tire pyrolysis oil).

[0053] Tires are mainly made of rubber for their elastic properties (a mixture of crosslinked natural and synthetic rubber elastomers, with additives such as silica, resin, sulfur, zinc oxide, carbon black, etc.) and textile and metal fibers for their reinforcing properties. As for plastic waste, it is generally a mixture of several polymers. It can include, alone or in a mixture, polyethylene (low and / or high density), polypropylene, polyethylene terephthalate, polyvinyl chloride and polystyrene. In addition, depending on the uses, plastics can contain, in addition to polymers, other compounds, such as plasticizers, pigments, dyes or even residues from polymerization catalysts. Plastic waste can also contain, to a minor extent, biomass from, for example, household waste.

[0054] Solid recovered fuels (SRF), also known as refuse derived fuel (RDF), or solid recovered fuels (SRF), are solid non-hazardous waste prepared for energy recovery, whether they come from household and similar waste, waste from economic activities or construction and demolition waste. SRF are generally a mixture of any combustible waste such as used tires, food by-products (fats, animal meal, etc.), viscose and wood waste, light fractions from shredders (e.g. from used vehicles, electrical and electronic equipment (WEEE), household and commercial waste, residues from the recycling of various types of waste, including certain municipal waste, plastic waste, textiles, wood among others. SRF generally contains plastic waste.

[0055] The pyrolysis oil included in the feedstock, whether derived from tires, plastics and / or CSR, comes from a pyrolysis step of a feedstock containing tires, plastic(s) and / or CSR in a pyrolysis unit.

[0056] The pyrolysis step can be carried out by thermal or catalytic pyrolysis treatment or can be prepared by hydropyrolysis (pyrolysis in the presence of a catalyst and hydrogen).

[0057] The pyrolysis step is generally carried out at a temperature between 250°C and 750°C. The pyrolysis step can be carried out under more or less severe conditions. The low severity pyrolysis step is carried out at a temperature between 250°C and 450°C, preferably between 275°C and 425°C, and particularly preferably between 300°C and 400°C. The low severity pyrolysis step produces pyrolysis oils rich in mono- and diolefins as well as a significant amount of aromatics, and which may include chlorinated compounds.

[0058] The high severity pyrolysis step is carried out at a temperature between 450°C and 750°C, preferably between 500°C and 700°C, and particularly preferably between 550°C and 650°C. The high severity pyrolysis step produces pyrolysis oils rich in aromatics, which may include chlorinated compounds.

[0059] The pyrolysis unit may include one or more reactors configured to convert the feedstock into gas-phase and liquid-phase products (e.g., simultaneously). The reactor(s) may contain one or more beds of inert materials or pyrolysis catalysts including sand, zeolite, or combinations thereof. Typically, the pyrolysis catalyst is capable of transferring heat to the components undergoing the pyrolysis process in the pyrolysis unit.

[0060] The pyrolysis unit may include one or more pieces of equipment, for example, one or more heated extruders, a heated rotary kiln, heated tank-type reactors, empty heated vessels, closed heated surfaces where the feedstock flows along the wall, vessels surrounded by ovens or furnaces, or other equipment providing a heated surface.

[0061] In one or more embodiments of the pyrolysis unit, a purge gas is used in all or part of the pyrolysis stage(s) to enhance the cracking of plastics and / or tires and / or CSR, produce valuable products, provide feed for steam cracking, or combinations thereof. The purge gas may include hydrogen (H2), nitrogen (N2), steam, product gases, or combinations thereof.

[0062] Pyrolysis oil, whether from tires, plastics and / or CSR, generally has a boiling point range of between 40°C and 1000°C, preferably between 45 and 650°C. Tire pyrolysis oil generally has a boiling point range of between 100°C and 1000°C, preferably between 150°C and 650°C. Plastic pyrolysis oil, which is generally lighter, generally has a boiling point range of between 40°C and 700°C, preferably between 45°C and 550°C.

[0063] It is also possible to use only a part of the pyrolysis oil obtained by pyrolysis, for example a pyrolysis oil which has been topped and / or trimmed beforehand by a prefractionation step.

[0064] The density of pyrolysis oil, whether from tires, plastics and / or CSR, generally has a density, measured at 15°C according to the ASTM D4052 method, between 0.75 and 1.05 g / cm 3, preferably between 0.75 and 0.95 g / cm 3 The density of tire pyrolysis oil, measured at 15°C according to ASTM D4052, is generally between 0.75 g / cm 3 and 1.05 g / cm 3 , preferably between 0.80 g / cm 3 and 0.98 g / cm 3 The density of plastic and / or CSR pyrolysis oil, measured at 15°C according to ASTM D4052, is generally lower and is generally between 0.75 and 0.99 g / cm 3 , preferably between 0.75 and 0.95 g / cm 3 .

[0065] The pyrolysis oil, whether from tires, plastics and / or CSR, is advantageously in liquid form at room temperature and comprises in particular a mixture of hydrocarbon compounds, in particular paraffins (n- and i-paraffins), olefins (mono- and / or diolefins), naphthenes and aromatics. In particular, depending on the origin of the feedstock treated by the pyrolysis unit, the pyrolysis oil may comprise up to 70% by weight of paraffins, up to 90% by weight of naphthenes, up to 90% by weight of olefins and up to 90% by weight of aromatics, it being understood that the sum of the paraffins, naphthenes, olefins and aromatics is equal to 100% by weight of the hydrocarbon compounds.

[0066] The tire pyrolysis oil generally contains a significant content of aromatic compounds, for example an aromatic compound content greater than 30 wt%, preferably greater than 40 wt%, and particularly preferably greater than 50 wt% relative to the weight of the tire pyrolysis oil.

[0067] Pyrolysis oil, whether from tires, plastics, and / or CSR, may contain diolefins. The diolefin content is commonly determined indirectly as the maleic anhydride value (MAV). The method is based on the Diels-Alder addition reaction between conjugated diolefins and maleic anhydride. The method for determining MAV is described in C. Lôpez-Garcia et al., Near Infrared Monitoring of Low Conjugated Diolefins Content in Hydrotreated FCC Gasoline Streams, Oil & Gas Science and Technology - Rev. IFP, Vol. 62 (2007), No. 1, pp. 57-68. MAV is expressed in mg of maleic anhydride reacted with 1 g of sample (mg / g). MAV preferably ranges between 5 and 100 mg / g in pyrolysis oils.

[0068] Pyrolysis oil, whether from tires, plastics and / or CSR, may contain some of the compounds of biological origin, such as for example tire pyrolysis oil which is produced from natural rubber type elastomers, or plastic and / or CSR pyrolysis oil produced from plastic and / or CSR waste which may contain, to a minor extent, biomass from, for example, household waste. The biological carbon content (according to the analytical method of radiocarbon isotope C 14 according to ASTM D6866) may be between 0 and 70% by weight, preferably between 0.1 and 60% by weight relative to the total weight of the pyrolysis oil. In the case of a tire pyrolysis oil, this may include a content of biological carbon (according to the analytical method of radiocarbon isotope C 14according to ASTM D6866) between 20-70% by weight, preferably between 30 and 60% by weight relative to the total weight of the pyrolysis oil. This makes it possible to incorporate a biological composition into the products of the process according to the invention.

[0069] The impurity levels in pyrolysis oils often depend on the origin of the oil. Thus, tire pyrolysis oils generally contain more heteroelements than plastic and / or CSR pyrolysis oils, including sulfur compounds, but also nitrogen, oxygen, and halogenated (especially chlorinated) compounds. They also generally contain more metals (especially silicon).

[0070] Pyrolysis oil, whether from tires, plastics and / or CSR, may include, and most often does include, in addition impurities such as metals, in particular iron, silicon, halogenated compounds, in particular chlorinated compounds. These impurities may be present at high levels, for example up to 500 ppm by weight or 700 ppm by weight or even 1000 ppm by weight, and even 5000 ppm by weight, of halogenated elements (in particular chlorine but also bromine, fluorine or iodine) provided by halogenated compounds, and generally between 1 and 1000 ppm by weight or between 1 and 700 ppm by weight or between 1 and 500 ppm by weight of halogenated elements. Pyrolysis oil can contain up to 500 ppm by weight or 700 ppm by weight or even 1000 ppm by weight or even 5000 ppm by weight of chlorine element provided by chlorinated compounds, and generally between 1 and 1000 ppm by weight or between 1 and 700 ppm by weight or even between 1 and 500 ppm by weight of chlorine element.Pyrolysis oil can contain up to 50 ppm by weight or 100 ppm by weight of bromine element provided by brominated compounds, and generally between 1 and 100 ppm by weight or between 1 and 50 ppm by weight of bromine element.

[0071] Pyrolysis oil, whether from tires, plastics and / or CSR, can contain up to 200 ppm by weight, or even 1500 ppm by weight of metallic or semi-metallic elements, and generally between 1 and 1500 ppm by weight or between 1 and 200 ppm by weight of metallic or semi-metallic elements. Alkali metals, alkaline earth metals, transition metals, poor metals and metalloids can be considered as contaminants of a metallic nature, called metals or metallic or semi-metallic elements. In particular, metals or metallic or semi-metallic elements include silicon, iron or both of these elements. Pyrolysis oil can contain up to 200 ppm by weight or even 1000 ppm by weight of silicon, and generally between 1 and 1000 ppm by weight or between 1 and 500 ppm by weight or even between 1 and 200 ppm by weight of silicon.Pyrolysis oil may contain up to 50 ppm by weight or 100 ppm by weight of iron, and generally between 1 and 100 ppm by weight or between 1 and 50 ppm by weight of iron. Pyrolysis oil may also contain phosphorus, sodium, calcium, potassium and magnesium.

[0072] Pyrolysis oil, whether from tires, plastics and / or CSR, may also include other impurities such as heteroelements provided in particular by sulfur compounds, oxygenated compounds and / or nitrogen compounds, at contents generally less than 40,000 ppm by weight of heteroelements and preferably less than 15,500 ppm by weight of heteroelements, and generally between 1 and 40,000 ppm by weight or between 1 and 15,500 ppm by weight of heteroelements.

[0073] Oxygenated compounds are generally present in a content of less than 15,000 ppm by weight and preferably less than 10,000 ppm by weight, and generally between 1 and 15,000 ppm by weight or between 1 and 10,000 ppm by weight of oxygen.

[0074] Nitrogen compounds are generally present in a content of less than 10,000 ppm by weight and preferably less than 8,000 ppm by weight, and generally between 1 and 10,000 ppm by weight or between 1 and 8,000 ppm by weight of nitrogen. Tire pyrolysis oils are generally more loaded with nitrogen compounds than plastic and / or CSR pyrolysis oils. The nitrogen compounds present in a tire pyrolysis oil are generally present in a content of less than 10,000 ppm by weight and preferably less than 8,000 ppm by weight, and generally between 2,000 and 10,000 ppm by weight or between 2,500 and 8,000 ppm by weight of nitrogen compounds.

[0075] The nitrogen compounds present in a plastic pyrolysis oil are generally present in a content of less than 5000 ppm by weight and preferably less than 2500 ppm by weight, and generally between 5 and 5000 ppm by weight or between 10 and 2500 ppm by weight of nitrogen compounds.

[0076] The sulfur content varies greatly depending on the origin of the pyrolysis oil.

[0077] The sulfur compounds present in a tire pyrolysis oil are generally present in a content of less than 15,000 ppm by weight and preferably less than 10,000 ppm by weight, and generally between 2,000 and 15,000 ppm by weight or between 2,500 and 12,000 ppm by weight of sulfur compounds, preferably between 3,000 and 11,000 ppm by weight of sulfur compounds.

[0078] The sulfur compounds present in a plastic pyrolysis oil are generally present in a content of less than 2000 ppm by weight and preferably less than 500 ppm by weight, and generally between 5 and 2000 ppm by weight or between 10 and 500 ppm by weight of sulfur compounds. The pyrolysis oil, whether from tires, plastics and / or CSR, may also include other impurities such as heavy metals such as mercury, arsenic, zinc and lead, for example up to 500 ppb by weight of mercury or arsenic, and generally between 1 and 300 ppb by weight or between 1 and 200 ppb by weight of heavy metals.

[0079] The feedstock of the process according to the invention comprises at least 5% by weight of a tire pyrolysis oil relative to the total weight of the feedstock. Said feedstock may consist solely of tire pyrolysis oil(s).

[0080] The feedstock may also comprise, in addition to at least 5% by weight of tire pyrolysis oil, any other pyrolysis oil, in particular a plastic pyrolysis oil and / or solid recovered fuels (SRF), and this in any proportion. Said feedstock may consist solely of tire pyrolysis oil(s) and plastic pyrolysis oil(s) and / or SRF. In this case, the feedstock comprises a tire pyrolysis oil in a content of between 5 and 99% by weight, preferably between 5 and 80% by weight, and particularly preferably between 5 and 50% by weight, and a plastic pyrolysis oil and / or SRF in a content of between 1 and 95% by weight relative to the total weight of the feedstock, preferably between 20 and 95% by weight, and particularly preferably between 50 and 95% by weight.

[0081] Said charge may comprise at least 50% by weight, preferably between 70 and 100% by weight, of pyrolysis oil, including at least 5% by weight of tire pyrolysis oil, relative to the total weight of the charge, i.e. preferably between 50 and 100% by weight, preferably between 70% and 100% by weight of pyrolysis oil including at least 5% by weight of tire pyrolysis oil.

[0082] The feedstock of the process according to the invention may further comprise, at a low content, typically between 1% and 50% by weight of the feedstock, or even between 1% and 30% or between 1 and 10% by weight, in addition to the tire pyrolysis oil and possibly the plastic and / or CSR pyrolysis oil, a conventional petroleum feedstock or a feedstock resulting from the conversion of biomass which is then co-treated with the pyrolysis oil of the feedstock.

[0083] The conventional petroleum feedstock can advantageously be a cut or a mixture of cuts of the naphtha, diesel or vacuum diesel type.

[0084] The feedstock resulting from the conversion of biomass may advantageously be chosen from vegetable oils, algae or algal oils, fish oils, used edible oils, and fats of vegetable or animal origin; or mixtures of such feedstocks. Said vegetable oils may advantageously be crude or refined, totally or partially, and derived from plants chosen from rapeseed, sunflower, soybean, palm, olive, coconut, copra, castor oil, cottonseed, peanut, linseed and crambe oils and all oils derived for example from sunflower or rapeseed by genetic modification or hybridization, this list not being exhaustive. Said animal fats are advantageously chosen from lard and fats composed of residues from the food industry or from the catering industries.Frying oils, various animal oils such as fish oils, tallow, lard can also be used. The feedstock resulting from biomass conversion can also advantageously be chosen from fatty acid methyl esters of vegetable and / or animal origin or fatty acid methyl esters from used edible vegetable oils.

[0085] The feedstock from biomass conversion may also be selected from feedstocks from thermal or catalytic biomass conversion processes, such as oils that are produced from biomass, particularly lignocellulosic biomass, with various liquefaction methods, such as hydrothermal liquefaction or pyrolysis. The term "biomass" refers to material derived from recently living organisms, which includes plants, animals and their by-products. The term "lignocellulosic biomass" refers to biomass derived from plants or their by-products. Lignocellulosic biomass is composed of carbohydrate polymers (cellulose, hemicellulose) and an aromatic polymer (lignin).

[0086] The feedstock from biomass conversion can also advantageously be chosen from feedstocks from the paper industry.

[0087] Pre-treatment (optional)

[0088] Said feedstock comprising a tire pyrolysis oil may advantageously be pretreated in at least one optional pretreatment step, prior to step a) of optional selective hydrogenation and / or step b) of hydrogenation, to obtain a pretreated feedstock which feeds step a) and / or step b).

[0089] Alternatively, this optional pretreatment step can reduce the amount of contaminants and solid particles. This optional pretreatment step can notably eliminate sediments that may form due to the unstable nature of pyrolysis oils and / or a compatibility problem between two different feedstocks.

[0090] Said optional pretreatment step may be implemented by any method known to those skilled in the art for reducing the quantity of contaminants. It may in particular comprise an adsorption step and / or a filtration step and / or a centrifugation step and / or a decantation step and / or an electrostatic separation step and / or a washing step using an aqueous solution and / or a gas stripping step.

[0091] The optional pretreatment step is advantageously carried out at a temperature between 20 and 400°C, preferably between 40 and 350°C, and at a pressure between 0.15 and 10.0 MPa abs, preferably between 0.2 and 7.0 MPa abs.

[0092] According to a variant, said optional pretreatment step is implemented in an adsorption section operated in the presence of at least one adsorbent. The adsorbent may be chosen from a zeolite, activated carbon, a clay, a silica or an alumina. Advantageously, said adsorbent comprises less than 1% by weight of metallic elements, preferably is free of metallic elements. By metallic elements of the adsorbent, it is meant the elements of groups VI B, VII B and VIII.

[0093] According to another variant, said optional pretreatment step is implemented in a washing section with an aqueous solution, for example water or an acidic or basic solution, or with an organic solvent. This washing section may comprise equipment for bringing the feedstock into contact with the aqueous solution and separating the phases so as to obtain the pretreated feedstock on the one hand and the aqueous solution comprising impurities on the other hand. Among this equipment, there may be for example a stirred reactor, a decanter, a mixer-decanter and / or a co- or counter-current washing column.

[0094] According to another variant, said optional pretreatment step is implemented by filtration. The filtration step makes it possible to remove inorganic solids, sediments and / or fines contained in the feed, in particular metals, metal oxides and metal chlorides. A filter is generally used whose pore size (for example the diameter or equivalent diameter) is less than 25 μm, preferably less than or equal to 10 μm, even more preferably less than or equal to 5 μm. It is also possible to use a series of filters with different pore sizes, in particular a series of filters having decreasing pore sizes in the direction of flow of the feed. These filter media are well known for industrial uses. Cartridge filters, self-cleaning filters, for example, are suitable.

[0095] Alternatively, filter aids, for example diatomaceous earth, can be used in the filtration system, as seeding, i.e. suspended in the load or as a pre-coat (coating according to English terminology) on the filter.

[0096] Regardless of the filters, especially those with additives, two filters can be used in parallel to clean and maintain one while the other is in operation.

[0097] According to another variant, said optional pretreatment step is implemented by centrifugation, by decantation or by electrostatic separation.

[0098] In another variant, said optional pretreatment step is implemented by gas stripping, thereby reducing the oxygen content in the feed. Gas stripping can remove oxygen (O2) that may be dissolved in the feed thereby reducing the likelihood of free radical formation leading to polymerization in downstream steps. The process typically involves contacting the feed with a stripping gas (e.g. H2, N2 or a mixture thereof), thereby transferring at least some of the dissolved oxygen from the feed or cut to the stripping gas, followed by separation of the stripping gas from the feed. Any dissolved H2 remaining in the feed after the gas stripping step is not a concern, given the hydrogenation steps performed downstream.

[0099] Said optional pre-treatment step generally comprises one or more, preferably several treatments described above.

[0100] Said optional pretreatment step thus makes it possible to obtain a pretreated feedstock which then feeds step b) of hydrogenation and / or step a) of selective hydrogenation when it is present.

[0101] Step a) of selective hydrogenation (optional)

[0102] According to the invention, the method optionally comprises a step a) of selective hydrogenation carried out in a reaction section using at least one fixed-bed reactor having n catalytic beds, n being an integer greater than or equal to 1, each comprising at least one selective hydrogenation catalyst, said selective hydrogenation reaction section being supplied at least by said feedstock and a gas stream comprising hydrogen, in the presence of at least one selective hydrogenation catalyst, at an average temperature between 100 and 280°C, a partial pressure of hydrogen between 1.0 and 10.0 MPa abs. and an hourly volumetric flow rate between 0.3 and 10.0 h- 1, to obtain a selectively hydrogenated effluent. The selective hydrogenation step is carried out under hydrogen pressure and temperature conditions making it possible to maintain said feedstock in the liquid phase and with a quantity of soluble hydrogen just necessary for selective hydrogenation of the diolefins present in said feedstock. The selective hydrogenation of the diolefins in the liquid phase thus makes it possible to avoid or at least limit the formation of "gums", i.e. the polymerization of the diolefins and therefore the formation of oligomers and polymers, which can block the reaction section of steps b) and c) downstream. Said selective hydrogenation step makes it possible to obtain a selectively hydrogenated effluent, i.e. an effluent with a reduced content of olefins, in particular diolefins, preferably free of diolefins.

[0103] Said reaction section implements a selective hydrogenation, in a fixed bed, in the presence of at least one selective hydrogenation catalyst, advantageously at an average temperature between 100 and 280°C, preferably between 110 and 250°C, preferably between 130 and 200°C, a hydrogen partial pressure between 1.0 and 10.0 MPa abs., preferably between 1.5 and 8.0 MPa abs. and very preferably between 2.0 and 6.0 MPa abs. and at an hourly volumetric flow rate (WH) between 0.1 and 10.0 h' 1 , preferably between 0.2 and 5.0 h' 1 , and very preferably between 0.3 and 3.0 h' 1 .

[0104] According to the invention, the "average temperature" of a reaction section corresponds to the Weight Average Bed Temperature (WABT) according to the established Anglo-Saxon term, well known to those skilled in the art. The average temperature is advantageously determined according to the catalytic systems, the equipment, and the configuration thereof, used. The average temperature (or WABT) is calculated as follows:

[0105] WABT = (Tætgg + T SfiJ flg) 2 with Tinput: the temperature of the flow at the inlet of the reaction section and Toutput: the temperature of the effluent at the outlet of the reaction section. Unless otherwise indicated, the “average temperature” of a reaction section is given at start-of-cycle conditions.

[0106] The hourly volume flow rate (WH) is defined here as the ratio of the hourly volume flow rate of the feedstock to the volume of catalyst(s).

[0107] The quantity of the gas flow comprising hydrogen (H2), feeding said reaction section of step a), is advantageously such that the hydrogen coverage is between 1 and 200 Nm 3 of hydrogen per m 3 load (Nm 3 / m 3 ), preferably between 1 and 150 Nm 3 of hydrogen per m 3 load (Nm 3 / m 3 ), preferably between 5 and 100 Nm 3 of hydrogen per m 3 load (Nm 3 / m 3 ). Hydrogen coverage is defined as the ratio of the volume flow rate of hydrogen taken under normal temperature and pressure conditions to the volume flow rate of the charge, without taking into account a recycled fraction, at 15°C (in normal m 3 , noted Nm 3 , of H2 per m 3 dump).

[0108] The gas stream comprising hydrogen, which feeds the reaction section of step a), may consist of a hydrogen supplement and / or recycled hydrogen originating in particular from separation step d).

[0109] Advantageously, the reaction section of said selective hydrogenation step comprises between 1 and 5 reactors. According to a particular embodiment of the invention, the reaction section comprises between 2 and 5 reactors, which operate in permutable mode, called "PRS" for Permutable Reactor System or "lead and lag". The association of at least two reactors in PRS mode makes it possible to isolate a reactor, unload the spent catalyst, reload the reactor with fresh catalyst and put said reactor back into service without stopping the process. The PRS technology is described, in particular, in patent FR2681871.

[0110] Advantageously, reactor internals, for example of the filter tray type, can be used to prevent clogging of the reactor(s). An example of a filter tray is described in patent FR3051375.

[0111] Advantageously, said at least one selective hydrogenation catalyst comprises a support, preferably mineral, and a hydro-dehydrogenating function.

[0112] The hydro-dehydrogenating function comprises in particular at least one element from group VIII, preferably chosen from nickel and cobalt, and / or at least one element from group VI B, preferably chosen from molybdenum and tungsten. The total content of oxides of the metal elements from groups VIB and VIII (i.e. the sum of the metal elements from groups VIB and VIII) is preferably between 1% and 40% by weight, preferably from 5% to 30% by weight relative to the total weight of the catalyst. The weight ratio, expressed as metal oxide, between the metal (or metals) from group VIB relative to the metal (or metals) from group VIII is preferably between 1 and 20, and preferably between 2 and 10.For example, the selective hydrogenation catalyst comprises between 0.5% and 10% by weight of nickel, preferably between 1% and 5% by weight of nickel (expressed as nickel oxide NiO relative to the weight of said catalyst), and between 1% and 30% by weight of molybdenum, preferably between 3% and 20% by weight of molybdenum (expressed as molybdenum oxide MoOa relative to the weight of said catalyst) on a preferably mineral support. The support of said at least one selective hydrogenation catalyst is preferably chosen from alumina, silica, silica-aluminas, magnesia, clays and mixtures thereof. Said support may contain doping compounds, in particular oxides chosen from boron oxide, in particular boron trioxide, zirconia, ceria, titanium oxide, phosphoric anhydride and a mixture of these oxides.Preferably, said selective hydrogenation catalyst comprises an alumina support, preferably doped with phosphorus and optionally boron. When phosphoric anhydride P2Os is present, its concentration is less than 10% by weight relative to the weight of the alumina and advantageously at least 0.001% by weight relative to the total weight of the alumina. When boron trioxide B2O3 is present, its concentration is less than 10% by weight relative to the weight of the alumina and advantageously at least 0.001% relative to the total weight of the alumina. The alumina used may be, for example, a γ (gamma) or γ (eta) alumina.

[0113] Said selective hydrogenation catalyst is for example in the form of extrudates.

[0114] According to another aspect of the invention, the selective hydrogenation catalyst as described above further comprises one or more organic compounds containing oxygen and / or nitrogen and / or sulfur. Such a catalyst is often referred to as an "additive catalyst". Generally, the organic compound is chosen from a compound comprising one or more chemical functions chosen from a carboxylic function, alcohol, thiol, thioether, sulfone, sulfoxide, ether, aldehyde, ketone, ester, carbonate, amine, nitrile, imide, oxime, urea and amide or compounds including a furan cycle or sugars.

[0115] Preferably, the selective hydrogenation step may use, upstream of the selective hydrogenation catalyst(s), at least one guard bed containing adsorbents of the alumina, silica-alumina, zeolite and / or activated carbon type, optionally containing metals from group VIB and / or VIII in the selective hydrogenation section. It is also possible to use a series of guard beds with particles of different diameters, in particular a series of guard beds having decreasing diameters in the direction of circulation of the feedstock (also called "grading" according to English terminology).

[0116] The content of impurities, in particular diolefins, in the selectively hydrogenated effluent obtained at the end of the selective hydrogenation step is reduced compared to that of the same impurities, in particular diolefins, included in the feedstock. The selective hydrogenation step a) makes it possible to convert at least 60% and preferably at least 70% of the diolefins contained in the feedstock. The selectively hydrogenated effluent, obtained at the end of the selective hydrogenation step a), is sent at least in part and preferably in full, preferably directly, to the hydrogenation step b).

[0117] Step b) hydrogenation

[0118] According to the invention, the method comprises a hydrogenation step b) carried out in a hydrogenation reaction section, using at least one fixed-bed reactor having n catalytic beds, n being an integer greater than or equal to 1, each comprising at least one hydrogenation catalyst, said hydrogenation reaction section being fed at least with said feedstock or said selectively hydrogenated effluent from step a) and a gas stream comprising hydrogen, said hydrogenation reaction section being carried out at an average temperature between 140 and 400°C, a hydrogen partial pressure between 1.0 and 10.0 MPa abs. and an hourly volumetric flow rate between 0.1 and 10.0 h -1 , to obtain a hydrogenated effluent.

[0119] Step b) is carried out in particular under hydrogen pressure and temperature conditions enabling the hydrogenation of the diolefins, possibly remaining after the optional selective hydrogenation step, and of the olefins at the start of the hydrogenation reaction section, while enabling, by means of a rising temperature profile, the hydrodemetallation and hydrodechlorination to be carried out, in particular at the end of the hydrogenation reaction section. A necessary quantity of hydrogen is injected so as to enable the hydrogenation of at least a portion of the diolefins and olefins present in the pyrolysis oil, the hydrodemetallation of at least a portion of the metals, in particular the retention of silicon, and also the conversion of at least a portion of the chlorine (into HCl).The hydrogenation of diolefins and olefins thus makes it possible to avoid or at least limit the formation of "gums", i.e. the polymerization of diolefins and olefins and therefore the formation of oligomers and polymers, which can block the reaction section of hydrotreatment step c). In parallel with hydrogenation, hydrodemetallation, and in particular the retention of silicon during step b), makes it possible to limit the catalytic deactivation of the reaction section of hydrotreatment step c). In addition, the conditions of step b) make it possible to convert at least part of the chlorine.

[0120] The person skilled in the art will easily understand that, in hydrogenation step b), hydrogenation reactions are carried out as described above but also in parallel a part of the other hydrotreatment reactions, and in particular hydrodesulfurization and hydrodenitrogenation, even if these reactions are rather favored in hydrotreatment step c), which is generally carried out at a higher temperature. The temperature in step b), whether the average temperature (WABT), the temperature at the inlet of the reaction section or the rise in temperature in step b) between the inlet and outlet of the reaction section, can in particular be controlled by injecting a diluent into step b), preferably a recycle of a part of the hydrocarbon effluent from step d) (or d1)) and / or at least a part of one or more cuts from step e), in particular by the recycle rate and / or by the temperature of the recycled effluent.

[0121] Said reaction section carries out hydrogenation in the presence of at least one hydrogenation catalyst, advantageously at an average temperature (or WABT as defined below) between 140 and 400°C, preferably between 240 and 350°C, and particularly preferably between 260 and 330°C, a hydrogen partial pressure between 1.0 and 10.0 MPa abs, preferably between 1.5 and 8.0 MPa abs. and at an hourly volumetric flow rate (WH) between 0.1 and 10.0 h' 1 , preferably between 0.2 and 5.0 h' 1 , and very preferably between 0.3 and 3.0 h' 1 .

[0122] The quantity of the gas flow comprising hydrogen (H2), feeding said reaction section of step b), is advantageously such that the hydrogen coverage is between 100 and 1500 Nm 3 of hydrogen per m 3 load (Nm 3 / m 3 ), preferably between 200 and 1000 Nm 3 of hydrogen per m 3load (Nm 3 / m 3 ), preferably between 250 and 800 Nm 3 of hydrogen per m 3 load (Nm 3 / m 3 ).

[0123] The definitions of mean temperature (WABT), WH and hydrogen coverage correspond to those described above in step a).

[0124] Hydrogen can come from a fossil source or a renewable source, for example from the gasification of plastic waste or produced by electrolysis.

[0125] Advantageously, the reaction section of said step b) comprises between 1 and 5 reactors, preferably between 2 and 5 reactors, and particularly preferably it comprises two reactors. The advantage of a hydrogenation reaction section comprising several reactors lies in an optimized treatment of the feedstock, while making it possible to reduce the risks of clogging of the catalytic bed(s) and therefore to avoid stopping the unit due to clogging.

[0126] According to a preferred variant, these reactors operate in permutable mode, called "PRS" for Permutable Reactor System or "lead and lag". The association of at least two reactors in PRS mode makes it possible to isolate a reactor, unload the spent catalyst, reload the reactor with fresh catalyst and put said reactor back into service without stopping the process. The PRS technology is described, in particular, in patent FR2681871.

[0127] According to a particularly preferred variant, the hydrogenation reaction section of step b) comprises two reactors operating in switchable mode.

[0128] The hydrogenation reaction section using at least one fixed bed reactor can operate with a descending or ascending flow of gas and liquid.

[0129] Advantageously, reactor internals, for example of the filter tray type, can be used to prevent clogging of the reactor(s). An example of a filter tray is described in patent FR3051375.

[0130] Advantageously, said hydrogenation catalyst comprises a support, preferably mineral, and a hydro-dehydrogenating function.

[0131] According to one variant, the hydro-dehydrogenating function comprises in particular at least one element from group VIII, preferably chosen from nickel and cobalt, and at least one element from group VI B, preferably chosen from molybdenum and tungsten. According to this variant, the total content expressed as oxides of the metal elements from groups VI B and VIII is preferably between 1% and 40% by weight, preferably from 5% to 30% by weight relative to the total weight of the catalyst. When the metal is cobalt or nickel, the metal content is expressed as CoO and NiO respectively. When the metal is molybdenum or tungsten, the metal content is expressed as MoCh and WO3 respectively. The weight ratio expressed as metal oxide between the metal (or metals) from group VI B relative to the metal (or metals) from group VIII is preferably between 1 and 20, and preferably between 2 and 10.

[0132] According to this variant, the reaction section of said step b) comprises for example a hydrogenation catalyst comprising between 0.5% and 12% by weight of nickel, preferably between 0.9% and 10% by weight of nickel (expressed as nickel oxide NiO relative to the weight of said catalyst), and between 1% and 30% by weight of molybdenum, preferably between 3% and 20% by weight of molybdenum (expressed as molybdenum oxide MoOa relative to the weight of said catalyst) on a preferably mineral support, preferably on an alumina support.

[0133] According to another variant, the hydro-dehydrogenating function comprises, and is preferably made up of, at least one element from group VIII, preferably nickel. According to this variant, the content of nickel oxides is preferably between 1 and 50% by weight, preferably between 10% and 30% by weight relative to the weight of said catalyst. This type of catalyst is preferably used in its reduced form, on a preferably mineral support, preferably on an alumina support.

[0134] The support of said hydrogenation catalyst is preferably chosen from alumina, silica, silica-aluminas, magnesia, clays and mixtures thereof. Said support may contain doping compounds, in particular oxides chosen from boron oxide, in particular boron trioxide, zirconia, ceria, titanium oxide, phosphoric anhydride and a mixture of these oxides. Preferably, said hydrogenation catalyst comprises an alumina support, optionally doped with phosphorus and optionally boron. When phosphoric anhydride P2O5 is present, its concentration is less than 10% by weight relative to the weight of the alumina and advantageously at least 0.001% by weight relative to the total weight of the alumina. When boron trioxide B2O3 is present, its concentration is less than 10% by weight relative to the weight of the alumina and advantageously at least 0.001% relative to the total weight of the alumina.The alumina used can be, for example, a y (gamma) or q (eta) alumina.

[0135] Said hydrogenation catalyst is for example in the form of extrudates.

[0136] Very preferably, step b) may use, in addition to the hydrogenation catalyst(s) described above, also at least one hydrogenation catalyst used in step b) comprising less than 1% by weight of nickel and at least 0.1% by weight of nickel, preferably 0.5% by weight of nickel, expressed as nickel oxide NiO relative to the weight of said catalyst, and less than 5% by weight of molybdenum and at least 0.1% by weight of molybdenum, preferably 0.5% by weight of molybdenum, expressed as molybdenum oxide MoOa relative to the weight of said catalyst, on an alumina support. This catalyst, which is lightly loaded with metals, may preferably be placed upstream or downstream of the hydrogenation catalyst(s) described above, preferably upstream.

[0137] Preferably, step b) may use upstream of the hydrogenation catalyst(s) at least one guard bed containing adsorbents of the alumina, silica-alumina, zeolite and / or activated carbon type possibly containing metals from group VI B and / or VIII. It is also possible to use a series of guard beds with particles of different diameters, in particular a series of guard beds having decreasing diameters in the direction of circulation of the feedstock (also called "grading" according to English terminology).

[0138] Said hydrogenation step b) makes it possible to obtain a hydrogenated effluent, i.e. an effluent with a reduced content of olefins, in particular diolefins, and metals, in particular silicon, and halogens, in particular chlorine. Hydrogenation step b) generally makes it possible to convert at least 40%, and preferably at least 60% of the diolefins as well as at least 40%, and preferably at least 60% of the olefins contained in the initial feedstock. The heat released by the saturation of the double bonds makes it possible to raise the temperature of the reaction medium and to initiate the hydrotreatment reactions, in particular the elimination, at least in part, of other contaminants, such as for example silicon and chlorine or nitrogen. Preferably, at least 50%, and more preferably at least 75% of the chlorine and silicon of the initial feedstock are respectively eliminated during step a).Generally, the silicon content is less than 10 ppm by weight in the hydrogenated effluent from step b).

[0139] When separation step d) is carried out after hydrotreatment step c), the hydrogenated effluent obtained at the end of hydrogenation step b) is sent at least in part and preferably in full, preferably directly, to hydrotreatment step c).

[0140] When separation step d) is carried out between steps b) and c), the hydrogenated effluent obtained at the end of hydrogenation step b) is sent, at least in part and preferably in full, preferably directly, to separation step d).

[0141] Step c) of hydrotreatment

[0142] According to the invention, the treatment method comprises a hydrotreatment step c) implemented in a hydrotreatment reaction section, implementing at least one fixed-bed reactor having n catalytic beds, n being an integer greater than or equal to 1, each comprising at least one hydrotreatment catalyst, said hydrotreatment reaction section being fed at least by said hydrocarbon effluent from step d) when the separation step d) is carried out between steps b) and c), and / or at least by the hydrogenated effluent from step b) when the separation step d) is carried out after step c), and a gas stream comprising hydrogen, said hydrotreatment reaction section being implemented at an average temperature between 250 and 430°C, a hydrogen partial pressure between 1.0 and 10.0 MPa abs. and an hourly volumetric flow rate between 0.1 and 10.0 h -1 , to obtain a hydrotreated effluent.

[0143] Advantageously, step c) implements hydrotreatment reactions well known to those skilled in the art, and more particularly hydrotreatment reactions such as the hydrogenation of aromatics, hydrodesulfurization and hydrodenitrogenation. In addition, the hydrogenation of the remaining olefins and halogenated compounds as well as the hydrodemetalation are continued. Said hydrotreatment reaction section is advantageously carried out at a pressure equivalent to that used in the reaction section of hydrogenation step b), and generally at a higher average temperature than that of the reaction section of hydrogenation step b). Thus, said hydrotreatment reaction section is advantageously carried out at an average hydrotreatment temperature between 250 and 430°C, preferably between 280 and 380°C, at a hydrogen partial pressure between 1.0 and 10.0 MPa abs. and at an hourly volumetric flow rate (WH) between 0.1 and 10.0 h-1 , preferably between 0.1 and 5.0 h -1 , preferably between 0.2 and 2.0 h -1 , preferably between 0.2 and 1h' 1 The hydrogen coverage in step c) is advantageously between 100 and 1500 Nm 3 of hydrogen per m 3 fresh load, and preferably between 200 and 1000 Nm 3 of hydrogen per m 3 fresh load, preferably between 250 and 800 Nm 3 of hydrogen per m 3 fresh charge. The definitions of average temperature (WABT), WH and hydrogen coverage correspond to those described above.

[0144] Advantageously, the reaction section of said step c) comprises between 1 and 5 reactors, preferably between 2 and 5 reactors. These reactors can operate in series and / or in parallel and / or in permutable mode (or PRS).

[0145] In a preferred embodiment, said hydrotreatment reaction section comprises a single fixed-bed reactor containing n catalytic beds, n being an integer greater than or equal to one, preferably between one and ten, more preferably between two and five. In a particularly preferred embodiment, the hydrogenation reaction section of step b) comprises two reactors operating in switchable mode followed by the hydrotreatment reaction section of step c) which comprises a single fixed-bed reactor.

[0146] The hydrotreatment reaction section using at least one fixed bed reactor can operate with a descending or ascending flow of gas and liquid.

[0147] Advantageously, reactor internals, for example of the filter tray type, can be used to prevent clogging of the reactor(s).

[0148] Advantageously, said hydrotreatment catalyst used in said step c) may be chosen from known hydrodemetallization, hydrotreatment and silicon capture catalysts, used in particular for the treatment of petroleum fractions, and combinations thereof. Known hydrodemetallization catalysts are, for example, those described in patents EP 0113297, EP 0113284, US 5221656, US 5827421, US 7119045, US 5622616 and US 5089463. Known hydrotreatment catalysts are, for example, those described in patents EP 0113297, EP 0113284, US 6589908, US 4818743 or US 6332976. Known silicon capture catalysts are, for example, those described in patent applications CN 102051202 and US 2007 / 080099.

[0149] In particular, said hydrotreatment catalyst comprises a support, preferably mineral, and at least one metallic element having a hydro-dehydrogenating function. Said metallic element having a hydro-dehydrogenating function advantageously comprises at least one element from group VIII, preferably chosen from the group consisting of nickel and cobalt, and / or at least one element from group VI B, preferably chosen from the group consisting of molybdenum and tungsten. The total content expressed as oxides of the metallic elements from groups VI B and VIII is preferably between 0.1% and 40% by weight, preferably from 5% to 35% by weight, relative to the total weight of the catalyst. When the metal is cobalt or nickel, the metal content is expressed as CoO and NiO respectively. When the metal is molybdenum or tungsten, the metal content is expressed as MoOa and WO3 respectively.The weight ratio expressed as metal oxide between the metal (or metals) of group VIB relative to the metal (or metals) of group VIII is preferably between 1.0 and 20, preferably between 2.0 and 10. For example, the hydrotreatment reaction section comprises a hydrotreatment catalyst comprising between 0.5% and 10% by weight of nickel, preferably between 1% and 8% by weight of nickel, expressed as nickel oxide NiO relative to the total weight of the hydrotreatment catalyst, and between 1.0% and 30% by weight of molybdenum, preferably between 3.0% and 29% by weight of molybdenum, expressed as molybdenum oxide MoOs relative to the total weight of the hydrotreatment catalyst, on a mineral support, preferably on an alumina support.

[0150] The support of said hydrotreatment catalyst is advantageously chosen from alumina, silica, silica-aluminas, magnesia, clays and mixtures thereof. Said support may also contain doping compounds, in particular oxides chosen from boron oxide, in particular boron trioxide, zirconia, ceria, titanium oxide, phosphoric anhydride and a mixture of these oxides. Preferably, said hydrotreatment catalyst comprises an alumina support, preferably an alumina support doped with phosphorus and optionally boron. When phosphoric anhydride P2O5 is present, its concentration is less than 10% by weight relative to the weight of the alumina and advantageously at least 0.001% by weight relative to the total weight of the alumina.When boron trioxide B2O3 is present, its concentration is less than 10% by weight relative to the weight of the alumina and advantageously at least 0.001% relative to the total weight of the alumina. The alumina used may be, for example, a γ (gamma) or (eta) alumina. Said hydrotreatment catalyst is, for example, in the form of extrudates.

[0151] Advantageously, said hydrotreatment catalyst of the process has a specific surface area of ​​between 200 and 800 m 2 / g, preferably between 250 and 600 m 2 / g, preferably between 300 and 400 m 2 / g. The specific surface area of ​​the hydrotreatment catalyst is measured by the BET method, i.e. the specific surface area determined by nitrogen adsorption in accordance with ASTM D 3663-78 based on the BRUNAUER-EMMETT-TELLER method described in the periodical 'The Journal of the American Chemical Society", 6Q, 309 (1938). Such a specific surface area allows for further improvement in the removal of contaminants, particularly metals such as silicon.

[0152] According to another aspect of the invention, the hydrotreatment catalyst as described above further comprises one or more organic compounds containing oxygen and / or nitrogen and / or sulfur as described above (additive catalyst).

[0153] Preferably, step c) can implement upstream of the hydrotreatment catalyst(s) at least one guard bed or a series of guard beds of the “grading” type as described above for step b).

[0154] Advantageously, hydrotreatment step c) allows the hydrogenation of at least 80%, and preferably of all of the olefins and halogenated compounds remaining after hydrogenation step b), but also the conversion at least in part of other impurities present in the feedstock, such as aromatic compounds, metallic compounds, sulfur compounds, nitrogen compounds, oxygenated compounds. Preferably, the nitrogen content at the outlet of step c) is less than 100 ppm by weight, and preferably less than 10 ppm by weight. Preferably, the sulfur content at the outlet of step c) is less than 100 ppm by weight, and preferably less than 10 ppm by weight. Step c) can also make it possible to further reduce the contaminant content, such as that of metals, in particular the silicon content.Preferably, the metal content at the outlet of step d) is less than 10 ppm by weight, and preferably less than 2 ppm by weight, and the silicon content is less than 5 ppm by weight. Preferably, the halogen element content at the outlet of step c) is less than 5 ppm by weight.

[0155] The preparation of catalysts for the selective hydrogenation, hydrogenation, hydrotreatment and hydrocracking stages (see below) is known and generally comprises a step of impregnation of the metals of group VIII and group VIB when present, and possibly phosphorus and / or boron on the support, followed by drying, then possibly calcination. In the case of an additive catalyst, the preparation is generally carried out by simple drying without calcination after introduction of the organic compound. Calcination here means a heat treatment under a gas containing air or oxygen at a temperature greater than or equal to 200°C. Before their use in a stage of the process, the catalysts are generally subjected to sulfurization in order to form the active species.

[0156] Depending on the content of sulfur compounds in the initial feedstock to be treated, a stream containing a sulfurizing agent may be injected upstream of the optional pretreatment step, the optional selective hydrogenation step a) and / or the hydrogenation step b) and / or the hydrotreatment step c) and / or upstream of one of the optional hydrocracking steps when they are present, preferably upstream of the hydrogenation step b) and / or the hydrotreatment step c) in order to ensure a sufficient quantity of sulfur to form the active species of the catalyst (in sulfide form).

[0157] This activation or sulfurization step is carried out by methods well known to those skilled in the art, and advantageously under a sulfide-reducing atmosphere in the presence of hydrogen and hydrogen sulfide. The sulfurizing agents are preferably H2S gas, elemental sulfur, CS2, mercaptans, sulfides and / or polysulfides, hydrocarbon fractions with a boiling point below 400°C containing sulfur compounds or any other compound containing sulfur used for the activation of hydrocarbon feedstocks in order to sulfurize the catalyst. Said sulfur-containing compounds are advantageously chosen from alkyl disulfides such as, for example, dimethyl disulfide (DMDS), alkyl sulfides, such as, for example, dimethyl sulfide, thiols such as, for example, n-butyl mercaptan (or 1-butanethiol) and polysulfide compounds of the tert-onylpolysulfide type.The catalyst can also be sulfurized by the sulfur contained in the feedstock to be desulfurized. Preferably, the catalyst is sulfurized in situ in the presence of a sulfurizing agent and a hydrocarbon feedstock. Very preferably, the catalyst is sulfurized in situ in the presence of the feedstock with added dimethyl disulfide.

[0158] The injection of a sulfurizing agent is particularly necessary at the beginning of the catalytic cycle, while the hLS is forming. Additional injections throughout the catalytic cycle may be necessary to compensate for the natural loss. However, using a tire pyrolysis oil with a high sulfur content can significantly reduce the consumption of the sulfurizing agent, or even eliminate its use completely. Step d) separation

[0159] According to the invention, the treatment method comprises a separation step d) carried out between steps b) and c) and / or after step c), said step being fed with the hydrogenated effluent from step b) when the separation step d) is carried out between steps b) and c), and / or with the hydrotreated effluent from step c) when the separation step d) is carried out after step c), and an aqueous solution, said step being carried out in a separation section, to obtain at least one gaseous effluent, one aqueous effluent and one hydrocarbon effluent.

[0160] This washing / separation step makes it possible in particular to eliminate the ammonium chloride salts, which are formed by reaction between the chloride ions, released by the hydrogenation of the chlorinated compounds in HCl form, in particular during the hydrogenation step then dissolution in water, and the ammonium ions, generated by the hydrogenation of the nitrogen compounds in the form of NH3 during the hydrotreatment step and / or supplied by injection of an amine then dissolution in water, and thus to limit the risks of blockage, in particular in the transfer lines and / or in the sections of the process of the invention and / or the transfer lines to the steam cracker, due to the precipitation of the ammonium chloride salts.This step also removes the hydrochloric acid formed by the reaction of hydrogen ions and halide ions released by the hydrogenation of halogenated compounds during the hydrogenation and possibly hydrotreatment step, which dissolve in the aqueous solution. When H2S is present in the hydrotreated effluent from the hydrotreatment step, the washing / separation step also removes ammonium sulfide salts ((NH4)2S) which are formed by reaction between the H2S from the hydrodesulfurization of sulfur compounds and the NH3 by dissolving them in the aqueous solution.

[0161] The washing / separation step is advantageously carried out at a temperature between 50 and 450°C, preferably between 100 and 440°C, preferably between 200 and 420°C, and particularly preferably between 250 and 420°C. It is important to operate in this temperature range (and therefore not to cool the hydrotreatment effluent too much) to avoid the risk of blockage in the lines due to the precipitation of ammonium chloride salts. Advantageously, the washing / separation step is carried out at a pressure close to that used in the hydrogenation step or the hydrotreatment step, preferably between 1.0 and 10.0 MPa abs, so as to facilitate the recycling of hydrogen. The aqueous solution may be water. It may also be a basic aqueous solution (by adding NaOH for example). Using a basic solution helps neutralize hydrogen halides and any dissolved salts.

[0162] Said separation section may comprise any separation means known to those skilled in the art, in particular one or more expansion tanks arranged in series, and / or one or more steam and / or hydrogen stripping columns, and / or an atmospheric distillation column, and / or a vacuum distillation column. The washing / separation step may advantageously be carried out in common or separate washing and separation equipment, this equipment being well known (separator tanks which can operate at different pressures and temperatures, pumps, heat exchangers, washing columns, etc.).

[0163] Advantageously, the washing / separation step comprises an injection of an aqueous solution, preferably an injection of water, into the hydrogenated effluent and / or the hydrotreated effluent, upstream of the washing / separation section, so as to dissolve at least in part and preferably all of the hydrogen halides (HCl in particular) and any salts present.

[0164] In a possible embodiment of the invention, the washing / separation step comprises the injection of an aqueous solution into the hydrogenated effluent and / or the hydrotreated effluent, followed by the washing / separation section advantageously comprising a separation phase making it possible to obtain at least one aqueous effluent loaded with hydrogen halides (HCl in particular) and any dissolved salts, said hydrocarbon effluent and a partially washed gaseous effluent. Said aqueous effluent and said hydrocarbon effluent can then be separated in a settling tank in order to obtain said washed hydrocarbon effluent and said aqueous effluent.Said partially washed gaseous effluent may in parallel be introduced into a washing column where it circulates countercurrently to an aqueous stream, preferably of the same nature as the aqueous solution injected into the hydrogenated and / or hydrotreated effluent, which makes it possible to eliminate at least in part, preferably in full, the hydrochloric acid contained in the partially washed gaseous effluent and thus to obtain said gaseous effluent, preferably comprising essentially hydrogen, and an acidic aqueous stream. Said aqueous effluent from the settling tank may optionally be mixed with said acidic aqueous stream, and be used, optionally in a mixture with said acidic aqueous stream in a water recycling circuit to supply the washing / separation step with said aqueous solution upstream of the washing / separation section and / or with said aqueous stream in the washing column.Said water recycling circuit may comprise a water make-up and / or a basic solution and / or a purge allowing the impurities to be removed. According to one embodiment, and depending on the content of chlorinated compounds in said feed, a stream containing a nitrogen compound such as ammonia or an amine, for example monoethanolamine, diethanolamine, monodiethanolamine and / or aniline, may be injected upstream of the selective hydrogenation step and / or upstream of the hydrogenation step and / or upstream of the hydrotreatment step in order to ensure a sufficient quantity of ammonium ions to combine the chloride ions formed during the hydrotreatment step in the form of ammonium chloride salts, thus making it possible to limit the formation of hydrochloric acid and thus to limit corrosion downstream of the separation section.The high content of nitrogen compounds in tire pyrolysis oil reduces or even eliminates the need to add a nitrogen compound.

[0165] The aqueous effluent obtained from the washing / separation step advantageously comprises ammonium salts and / or hydrochloric acid.

[0166] Said gaseous effluent obtained at the end of the washing / separation step advantageously comprises hydrogen, preferably comprises at least 60% by volume, preferably at least 70% by volume, of hydrogen. Said gaseous effluent obtained at the end of the washing / separation step contains very little chlorine, generally at a content of less than 3 ppm by weight of chlorine, which makes it possible to send it to a refining unit requiring hydrogen. According to one embodiment, said gaseous effluent can at least partly be recycled to one of the steps of the process according to the invention requiring hydrogen (steps a), b), c)) and optionally at least one hydrocracking step when it is / are present), the recycling system being able to comprise a purification section (for example adsorption of heavy metals such as mercury).

[0167] According to one variant, the separation step d) is carried out after the hydrotreatment step c). When the separation step d) is carried out after the hydrotreatment step c), the hydrocarbon effluent from the separation step d) may be sent, in part or in full, either directly to the inlet of a steam cracking unit or to an optional fractionation step e). Preferably, the hydrocarbon effluent is sent, in part or in full, to a fractionation step e). Preferably, the separation step d) is carried out after the hydrotreatment step c).

[0168] According to another variant, the separation step d) is carried out between steps b) and c). When the separation step d) is carried out between steps b) and c), the hydrocarbon effluent from the separation step d) is sent, at least in part and preferably in full, preferably directly, to the hydrotreatment step c). This variant is advantageous when the feed contains a lot of halogenated compounds, in particular chlorinated compounds. Indeed, the chlorine (in the form of HCl) contained in the effluent from the hydrogenation step b) can be deposited on the hydrotreatment catalyst of step c), thus leading to a drop in activity and a reduction in the duration of the catalytic cycle.

[0169] According to another variant, the separation step d) can be carried out after step c) and between steps b) and c). In this case, step d) is carried out twice. This variant is of interest for feeds heavily loaded with halogenated compounds, and in particular with chlorinated compounds.

[0170] At least a portion of the hydrocarbon effluent from separation step d) when separation step d) is carried out after hydrotreatment step c), and / or at least a portion of the hydrotreated effluent from step c) when separation step d) is carried out between steps b) and c), can be recycled upstream of step b) and / or step c) and / or upstream of the selective hydrogenation step a). Recycling to or upstream of at least one of the reaction steps advantageously makes it possible, on the one hand, to dilute the impurities and, on the other hand, to control the temperature in the reaction step(s), in which the reactions involved can be highly exothermic. The injection of the recycle stream can be carried out at the level of the first catalytic bed of the reaction section of steps a), b) and / or c) or between the different catalytic beds of each section.When the reaction section comprises two reactors operating in switchable mode, at least part of the recycle stream can be recycled between the two reactors.

[0171] Advantageously, the quantity of recycled effluent is adjusted so that the weight ratio between the recycle stream and the feed, i.e. the feed to be treated feeding the overall process, is less than or equal to 10, preferably less than or equal to 7, and preferably greater than or equal to 0.001, preferably greater than or equal to 0.01, and more preferably greater than or equal to 0.1. Preferably, the quantity of recycle is adjusted so that the weight ratio between the recycle stream and the feed is between 0.01 and 10, preferably between 0.1 and 7, and more preferably between 0.2 and 5.

[0172] This recycle rate makes it possible in particular to control the temperature rise in step b). Indeed, when the recycle rate is high, the dilution rate of the feedstock is high, and the temperature rise at the start of the reaction section of step b), in particular due to the hydrogenation reactions of the diolefins, is thus controllable by the dilution effect. Preferably, an additional gas stream comprising hydrogen is advantageously introduced at the inlet of each reactor, in particular operating in series, and / or at the inlet of each catalytic bed from the second catalytic bed of the reaction section. These additional gas streams are also called cooling streams. They make it possible to control the temperature in the reactor in which the reactions carried out are generally very exothermic. This cooling stream can be injected into the reaction section of step a), b), c) or f).

[0173] According to a preferred variant, at least a portion of the recycled effluent can advantageously be either cooled, or preheated, if necessary, or kept at the same temperature as at the outlet of separation step d) when separation step d) is carried out after hydrotreatment step c), and / or as at the outlet of hydrotreatment step c) when separation step d) is carried out between steps b) and c), before reintroducing it into the process according to the invention.

[0174] According to a variant, the feedstock, before being preferably mixed with at least a portion of the recycled effluent, may be preheated by direct heating to a temperature of up to 200°C, preferably up to 180°C, and particularly preferably up to 150°C. Above this temperature, contact with a wall during direct heating may induce the formation of gums and / or coke, which may cause fouling and an increase in the pressure drop of the feedstock heating system and of the catalyst bed(s), in particular when a selective hydrogenation step a) is not carried out. Heating the feedstock to a temperature above 150°C, preferably above 180°C, and particularly preferably above 200°C is preferably carried out by indirect heating with a hot diluent, preferably with at least a portion of the recycled effluent.Thus, the temperature rise above 150°C, preferably above 180°C and particularly preferably above 200°C of the feedstock is caused by mixing with a hotter liquid, and not by contact with a heated wall. This makes it possible to locally limit high temperatures. This type of heating by mixing with an inert hot liquid therefore makes it possible to limit undesirable reactions such as the polymerization of diolefins (gum formation) and / or the formation of coke, and to adjust the inlet temperature of the stream in step b) so as to initiate the hydrogenation reaction of the unsaturations, preferably at the lowest possible temperature, while controlling the exothermicity of these reactions by a dilution effect of the reactive species. According to another variant, the feedstock is entirely heated by indirect heating by at least part of the recycled effluent.In this case, the feed is not preheated before being mixed with at least part of the recycled effluent.

[0175] Another heating stream advantageously consists of a hydrogen-rich gaseous effluent from the hydrogen supplement and / or the gaseous effluent from separation step d).

[0176] Variant step d) of two-step separation

[0177] In a possible embodiment of the invention, the separation step d) which can be carried out after step c) and / or between steps b) and c) can comprise two steps, a first separation step carried out "hot", followed by a second separation step carried out "cold".

[0178] This embodiment makes it possible to eliminate, by the combination of hot separation step d1) followed by cold separation / washing step d2), the chlorine in the form of ammonium chloride salts in a clever way. The chloride ions, released by the hydrogenation of the chlorinated compounds in HCl form during steps b) and c) (hydrodechlorination) and the ammonia generated by the hydrogenation of the nitrogen compounds in the form of NH3 during step c) in particular (hydrodenitrogenation), largely leave in the gaseous effluent thanks to the hot separation of step d1). Indeed, the high temperature of this separation step d1) prevents the precipitation of ammonium chloride salts which are formed by reaction between the chloride ions and the ammonium ions. The separation at a lower temperature in step d2) of the gaseous effluent and a portion of the liquid effluent causes these ammonium chloride salts to precipitate.The water washing in this step d2) allows these salts to be dissolved in the aqueous effluent. This produces a hydrocarbon effluent free of chlorine.

[0179] According to this embodiment, separation step d) may comprise the following steps: d1) a separation step, fed with the hydrogenated effluent from step b) when separation step d) is carried out between steps b) and c), and / or with the hydrotreated effluent from step c) when separation step d) is carried out after step c), said step being carried out at a temperature higher than the precipitation temperature of the ammonium halides and at a pressure substantially identical to the pressure of step b) to obtain at least a first gaseous effluent and a liquid effluent, a part of which is optionally recycled, as recycled effluent, upstream of step b), d2) a separation step, fed with the first gaseous effluent and optionally at least a part of the liquid effluent from step d 1 ), and an aqueous solution,said step being carried out at a temperature lower than the precipitation temperature of the ammonium halides and at a pressure substantially identical to or lower than the pressure of step b), to obtain at least a second gaseous effluent, an aqueous effluent and a hydrocarbon effluent.,

[0180] When the separation step d) is carried out after step c) and between steps b) and c), it is possible in particular to carry out a (first) separation step d1) "hot" (without step d2)), followed by a (second) separation step d1) and / or d2) after step c). Thus, in the first separation d1) "hot" between steps b) and c), at least a first gaseous effluent and a liquid effluent are obtained, a part of which is recycled, as recycled effluent, upstream of step b). The gaseous effluent and the other part of the liquid effluent are then introduced into the hydrotreatment step c). The hydrotreated effluent is then treated according to step d2) ("cold" separation with washing), optionally supplemented by a step d1) after step c). This configuration has the advantage of obtaining a hot recycle allowing the load to be preheated and the exothermicity of this step b) to be controlled while only requiring one wash (after step c) to eliminate the salts.

[0181] Step d1) hot separation

[0182] The high temperature of this separation step d1) prevents the precipitation of ammonium halide salts which are formed by reaction between the halide ions and the ammonium ions in order to recover a gaseous effluent containing the majority of the halides in the form of hydrogen halides (HCl) and gaseous ammonia, and a liquid effluent containing very little halides and ammonia.

[0183] The precipitation temperature of ammonium halides is understood to mean the temperature (under given conditions, such as concentration and pressure) at which gaseous ammonia and hydrogen halides precipitate, either by reacting to form solid crystals of ammonium halides or by dissolving in water. The precipitation temperature depends on the halide concentrations and the pressure according to thermodynamic principles. The precipitation temperature of ammonium halides is generally between 150 and 300°C, often between 180 and 295°C, and particularly between 200° and 290°C, under the conditions of use of the present process.

[0184] The temperature at which the separation of step d1) is carried out must be higher than the precipitation temperature of the ammonium halides in order to recover a gaseous effluent containing the majority of the halides in the form of hydrogen halides (HCl) and gaseous ammonia, and a liquid effluent containing very little halides and ammonia. The temperature at which the separation of step d1) is carried out is generally between 200 and 450°C, preferably between 220 and 330°C, and particularly preferably between 240 and 300°C.

[0185] The term "pressure substantially equal to the pressure of step b)" means the pressure of step b) with a pressure difference of between 0 and 1 MPa, preferably of between 0.005 and 0.3 MPa, and particularly preferably of between 0.01 and 0.3 MPa relative to the pressure of step b). Preferably, the pressure of step d1) is the pressure of step b) less the pressure losses.

[0186] Separation step d1) can advantageously be implemented by any method known to those skilled in the art such as, for example, the combination of one or more separator(s) (balloon(s)), and / or one or more stripping column(s), this or these separator(s) (balloon(s)) and / or columns optionally being able to be supplied with a stripping gas, for example a hydrogen-rich gas stream. Preferably, step d1) is implemented with a single separator (balloon).

[0187] The separation step d1) is a so-called high pressure or medium pressure high temperature separation step, also known to those skilled in the art under the name HHPS (for “Hot High Pressure Separator” according to English terminology). Thus, this step d1) preferably uses a so-called “hot high pressure” separator, the pressure being substantially equal to the operating pressure of step b).

[0188] The gas / liquid separation has an efficiency corresponding to the solubility and Henry's law. This means that an equilibrium quantity of halides in the form of hydrogen halides will remain in the liquid effluent obtained in step d1). These halides will be released into the gaseous effluent during the cold separation step d2) and then evacuated by dissolution in the aqueous effluent.

[0189] Advantageously, a portion of the liquid effluent from step d1) is recycled upstream of step b) and / or possibly upstream of step a) as recycled effluent in the recycle quantities described above. Apart from the advantages of dilution of impurities and temperature control as described above, the recycle notably allows indirect heating of the feedstock or the selectively hydrogenated effluent, by simple mixing of the “cold” feedstock or the “cold” selectively hydrogenated effluent with the hot recycle.

[0190] According to a preferred variant, at least a portion of the recycled effluent can advantageously be either cooled, or preheated, if necessary, or kept at the same temperature as at the outlet of separation step d1) when separation step d) is carried out after hydrotreatment step c), and / or as at the outlet of hydrotreatment step c) when separation step d) is carried out between steps b) and c), before reintroducing it into the process according to the invention.

[0191] The high pressure and high temperature separation makes it possible on the one hand to maximize energy recovery by hot recycling of a portion of the liquid effluent. Indeed, the energy to reach the necessary inlet temperature in step b), and / or possibly in step a) is at least partly provided by the heat of a portion of the recycled effluent from step d1) and also makes it possible to reduce or even eliminate any preheating by direct heating of the feedstock beyond a temperature above 200°C to avoid the formation of gums. In addition, the fact of preferably recycling at least a portion of the liquid effluent at high pressure makes it possible to save energy for its pressurization in step b).

[0192] High pressure and high temperature separation also makes it possible to minimize the quantity of light fraction (naphtha cut) contained in the liquid effluent. At this temperature, almost all of the light fraction of the effluent (naphtha) leaves as gaseous effluent to the cold separation / washing step d2) while in the liquid phase we have mainly the heavy fraction of the feed (middle distillate cut). When recycling part of the liquid effluent to step b), ppH2 is favored in step b) because the light fraction (naphtha) could partially vaporize and lower the ppH2 if it were not at least partially eliminated during the high pressure and high temperature separation. The elimination of the light fraction comprising the naphtha can optionally be increased by a slight expansion upstream of at least one separator implemented in step d2), even if this implementation is not preferred due to the energy loss linked to the expansion.Another option to increase the removal of the light fraction including naphtha may be to perform stripping, for example by injecting a hydrogen-rich gas into step d1).

[0193] Step d2) cold separation and washing

[0194] According to the invention, the treatment method may comprise a separation step d2), supplied with the first gaseous effluent and optionally at least part of the liquid effluent from step d1) and an aqueous solution, said step being carried out at a temperature lower than the precipitation temperature of the ammonium halides, and at a pressure substantially identical to or lower than the pressure of step b), to obtain at least a second gaseous effluent, an aqueous effluent and a hydrocarbon effluent.

[0195] The separation of step d2) at a temperature lower than the precipitation temperature of the ammonium halides from the gaseous effluent and possibly at least part of the liquid effluent from step d1) causes the ammonium halide salts to precipitate, which are formed by reaction between the halide ions and the ammonium ions contained in particular in the gaseous effluent.

[0196] Cold separation step d2) is fed with the gaseous effluent alone from step d1) or with the gaseous effluent mixture and at least part of the liquid effluent from step d1). Preferably, cold separation step d2) is fed with the gaseous effluent mixture and at least part of the liquid effluent. According to a variant, cold separation step d2) is fed with the gaseous effluent mixture and all of the liquid effluent. Carrying out cold separation step d2) on the gaseous effluent and liquid effluent mixture has the advantage of extracting not only the contaminants from the gaseous effluent, but also the hydrogen halides (HCl) dissolved in the liquid effluent. Indeed, the hydrogen halides dissolved in the liquid effluent from step d1) are released and also form ammonium halides with the ammonia present in the gaseous effluent.

[0197] Washing with an aqueous solution in this step d2) allows these salts to be dissolved in the aqueous effluent. This produces a hydrocarbon effluent freed from halides, a gaseous effluent freed from halides and an aqueous effluent in which the ammonium halide salts are dissolved.

[0198] The temperature at which the separation of step d2) is carried out must be lower than the precipitation temperature of the ammonium halides in order to precipitate the ammonium halide salts. The temperature at which the separation of step d2) is carried out is greater than or equal to 20°C and less than 200°C, preferably between 25 and 120°C, and particularly preferably between 30 and 70°C.

[0199] The term "pressure substantially equal to the pressure of step b)" means the pressure of step b) with a pressure difference of between 0 and 1 MPa, preferably of between 0.005 and 0.3 MPa, and particularly preferably of between 0.01 and 0.3 MPa relative to the pressure of step b). Preferably, the pressure of step d2) is the pressure of step b) less the pressure losses. The fact of operating at least part of the separation step d2) at a pressure substantially identical to the operating pressure of step b) also facilitates the recycling of hydrogen contained in the gaseous effluent.

[0200] The separation step d2) may also be carried out at a pressure lower than the pressure of step b). The separation step d2) may also comprise a (first) separation step at a pressure substantially equal to the operating pressure of step b), followed by at least one further separation step carried out at the same or lower temperature and at a lower pressure than each separation step of the preceding step d2).

[0201] Separation step d2) may advantageously be implemented by any method known to those skilled in the art, such as, for example, the combination of one or more separator(s) (drum(s)), and / or one or more stripping column(s), this or these separator(s) (drum(s)) and / or columns optionally being fed with a stripping gas, for example a hydrogen-rich gas stream. Separation step d2) may, for example, comprise a sour water stripping column (also called a "sour water stripper" in English terminology) of the withdrawn aqueous effluent, an acid gas scrubbing column to purify the hydrogen-rich gas before recycling, a column for stabilising the washed liquid effluent to remove dissolved gases.

[0202] Preferably, step d2) is implemented with a single separator (balloon). The separation step d2) is preferably implemented in at least one so-called high pressure or medium pressure low temperature separator ball, also known to those skilled in the art as CHPS (for “Cold High Pressure Separator” according to English terminology). Thus, this step d2) preferably implements a so-called “cold high pressure” separator, the pressure being substantially equal to the operating pressure of step b).

[0203] Step e) of splitting (optional)

[0204] The process according to the invention may comprise a step of fractionation of all or part, preferably all, of the hydrocarbon effluent from step d) when the separation step d) is carried out after step c), and / or of all or part, preferably all, of the hydrotreated effluent from step c) when the separation step d) is carried out between steps a) and c), to obtain at least one gas stream, a naphtha cut and at least one middle distillate cut.

[0205] The term "naphtha cut" means a hydrocarbon cut comprising compounds having a boiling point generally less than or equal to 175°C, in particular between 80 and 175°C.

[0206] The term "middle distillate cut" refers to a hydrocarbon cut comprising compounds with a boiling point generally above 175°C. The heavy cut may include middle distillates such as a diesel cut and / or a kerosene cut. It may also include heavier compounds.

[0207] Depending on the destination or use of the cuts from fractionation step e), the person skilled in the art will adjust the cut points in the stripping and / or distillation operations. For example, it may be necessary to adjust the end point of the naphtha cut to 150, 175 or 200°C, or even 250°C.

[0208] Step e) makes it possible in particular to eliminate gases dissolved in the hydrotreated liquid effluent, such as for example ammonia, hydrogen sulfide and light hydrocarbons having 1 to 4 carbon atoms.

[0209] The optional fractionation step e) is advantageously carried out at a pressure less than or equal to 1.0 MPa abs., preferably between 0.1 and 1.0 MPa abs.

[0210] According to one embodiment, step e) can be carried out in a section advantageously comprising at least one stripping column equipped with a reflux circuit comprising a reflux drum. Thus, the lightest compounds are entrained at the top of the column and in the reflux circuit comprising a reflux drum in which a gas / liquid separation takes place. The gaseous phase which comprises the light hydrocarbons is withdrawn from the reflux drum, in a gas stream. The naphtha cut is advantageously withdrawn from the reflux drum, in a liquid stream. The middle distillate cut is advantageously withdrawn at the bottom of the stripping column.

[0211] According to another embodiment, step e) can be carried out in a section comprising one or more separator tank(s). Advantageously, at least one so-called low-pressure, low-temperature separator tank will be used in order to eliminate the gases dissolved in the hydrotreated liquid effluent.

[0212] According to other embodiments, fractionation step e) may implement a stripping column or a balloon separator followed by a distillation column or only a distillation column.

[0213] The naphtha cut and the middle distillate cut, optionally mixed, may be sent, in whole or in part, to a steam cracking unit, at the end of which olefins may be (re)formed to participate in the formation of polymers. Preferably, only a portion of said cuts is sent to a steam cracking unit; at least a fraction of the remaining portion is optionally recycled in at least one of the steps of the process and / or sent to a fuel storage unit, for example a naphtha storage unit, a diesel storage unit or a kerosene storage unit, derived from conventional petroleum feedstocks.

[0214] According to a preferred embodiment, the naphtha cut, all or part, is sent to a steam cracking unit, while the middle distillate cut is sent to a hydrocracking step f) and / or sent to a fuel storage unit.

[0215] In a particular embodiment, the optional fractionation step e) can make it possible to obtain, in addition to a gas stream, a naphtha cut (generally comprising compounds having a boiling point less than or equal to 175°C, preferably between 80 and 175°C), and a middle distillate cut (generally comprising compounds having a boiling point greater than 175°C and less than 385°C), and a heavy hydrocarbon cut (generally comprising compounds having a boiling point greater than or equal to 385°C).The naphtha cut may be sent, in whole or in part, to a steam cracking unit and / or to the naphtha storage unit from conventional petroleum feedstocks, it may still be recycled; the middle distillate cut may also be, in whole or in part, either sent to a steam cracking unit, or to a diesel storage unit from conventional petroleum feedstocks, or to the hydrocracking stage f) when it is present, or still be recycled; the heavy cut may, for its part, be sent, at least in part, to a steam cracking unit, or be sent to the hydrocracking stage when it is present.

[0216] In another particular embodiment, the optional fractionation step e) can make it possible to obtain, in addition to a gas stream, a naphtha cut (generally comprising compounds having a boiling point less than or equal to 175°C, preferably between 80 and 175°C), and a kerosene cut (generally comprising compounds having a boiling point greater than 175°C and less than or equal to 280°C), a diesel cut (generally comprising compounds having a boiling point greater than 280°C and less than 385°C) and a heavy hydrocarbon cut (generally comprising compounds having a boiling point greater than or equal to 385°C). The naphtha cut, the kerosene cut and / or the diesel cut may be, in whole or in part, either sent to a steam cracking unit, or respectively to a naphtha, kerosene or diesel pool from conventional petroleum feedstocks, or recycled.The diesel and / or kerosene cuts may also be sent to the hydrocracking step f) when present. The heavy cut may be sent, at least in part, to a steam cracking unit, or be sent to the hydrocracking step f) when present. In another particular embodiment, the naphtha cut from step e) is split into a heavy naphtha cut (generally comprising compounds having a boiling point between 80 and 175°C) and a light naphtha cut (generally comprising compounds having a boiling point below 80°C), at least a portion of said heavy naphtha cut being sent to an aromatic complex comprising at least one naphtha reforming step in order to produce aromatic compounds. According to this embodiment, at least a portion of the light naphtha cut is sent to the steam cracking step g) described below.

[0217] When the content of tire pyrolysis oil is high in the feedstock (i.e. greater than 50% by weight of the feedstock), the naphtha cut from the process according to the invention can also be sent to a catalytic reforming unit. Indeed, the high aromatic content in tire pyrolysis oils makes it possible to obtain a very aromatic and naphthenic naphtha cut which has a high octane number (high RON / MON (RON = Research Octane Number and Motor Octane Number according to English terminology)).

[0218] The gaseous effluent(s) from fractionation step e) may be subject to additional purification(s) and separation(s) in order to recover at least light hydrocarbons, in particular ethane, propane and butane, which may advantageously be sent separately or as a mixture to one or more furnaces of steam cracking step g) so as to increase the overall yield of olefins.

[0219] Step f) hydrocracking (optional)

[0220] According to a variant, the process of the invention may comprise a hydrocracking step f) with at least a portion of said effluent from step d) when the separation step d) is carried out after step c), and / or with at least a portion of the hydrotreated effluent from step c) when the separation step d) is carried out between steps b) and c), and / or with at least a portion of the middle distillates cut from the fractionation step e).

[0221] Advantageously, step f) implements the hydrocracking reactions well known to those skilled in the art, and more particularly makes it possible to convert heavy compounds, for example compounds having a boiling point above 175°C, into compounds having a boiling point less than or equal to 175°C. Other reactions, such as the hydrogenation of olefins, aromatics, hydrodemetallation, hydrodesulfurization, hydrodenitrogenation, etc. can continue. Compounds having a boiling point above 175°C contain, compared to lighter compounds, more naphthenic, naphtheno-aromatic and aromatic compounds, thus leading to a higher C / H ratio. This high ratio is a cause of coking in the steam cracker, thus requiring steam cracking furnaces dedicated to this cut.When we want to minimize the yield of these heavy compounds (middle distillate cut) and maximize the yield of light compounds (naphtha cut), we can transform these compounds at least in part into light compounds by hydrocracking, a cut generally favored for a steam cracking unit.

[0222] Thus, the process of the invention may comprise a hydrocracking step f) implemented in a hydrocracking reaction section, implementing at least one fixed-bed reactor having n catalytic beds, n being an integer greater than or equal to 1, each comprising at least one hydrocracking catalyst, said hydrocracking reaction section being fed with at least a portion of said effluent from step d) when the separation step d) is carried out after step c), and / or with at least a portion of the hydrotreated effluent from step c) when the separation step d) is carried out between steps b) and c), and / or with at least a portion of the middle distillate cut from the fractionation step e) and a gas stream comprising hydrogen, said hydrocracking reaction section being implemented at an average temperature between 250 and 450°C, a hydrogen partial pressure between 1.5 and 20.0 MPa abs.and an hourly volumetric velocity between 0.1 and 10.0 h. -1 to obtain a first hydrocracked effluent.

[0223] Thus, said hydrocracking reaction section is advantageously carried out at an average temperature between 250 and 480°C, preferably between 320 and 450°C, at a hydrogen partial pressure between 1.5 and 20.0 Mpa abs., preferably between 3 and 18.0 Mpa abs., and at an hourly volumetric flow rate (WH) between 0.1 and 10.0 h -1 , preferably between 0.1 and 5.0 h' 1 , preferably between 0.2 and 4 h -1 The hydrogen coverage in step f) is advantageously between 80 and 2000 Nm 3 of hydrogen per m 3 of fresh charge which feeds step f), and preferably between 200 and 1800 Nm 3 of hydrogen per m 3of fresh feedstock that feeds step f). The definitions of the average temperature (WABT), the WH and the hydrogen coverage correspond to those described above. Advantageously, said hydrocracking reaction section is operated at a pressure equivalent to that used in the reaction section of step b) of hydrogenation or step c) of hydrotreatment.

[0224] Advantageously, said step f) is carried out in a hydrocracking reaction section comprising at least one, preferably between one and five, fixed bed reactor(s) having n catalytic beds, n being an integer greater than or equal to one, preferably between one and ten, preferably between two and five, said bed(s) each comprising at least one, and preferably not more than ten, hydrocracking catalyst(s).

[0225] The hydrocracking reaction section using at least one fixed bed reactor can operate with a descending or ascending flow of gas and liquid.

[0226] The hydrocracked effluent may at least partly be recycled in steps b), c), d) or e).

[0227] The hydrocracking step can be carried out in one (step f) or two steps (step f) and f')). When it is carried out in two steps, a separation of the effluent from the first hydrocracking step f) is carried out, making it possible to obtain a hydrocarbon cut comprising compounds having a boiling point above 175°C (middle distillate cut), which is introduced into the second hydrocracking step f') comprising a second dedicated hydrocracking reaction section, different from the first hydrocracking reaction section f). This configuration is particularly suitable when it is desired to produce only a naphtha cut.

[0228] The second hydrocracking step f') implemented in a hydrocracking reaction section, implementing at least one fixed bed reactor having n catalytic beds, n being an integer greater than or equal to 1, each comprising at least one hydrocracking catalyst, said hydrocracking reaction section being fed with at least a portion of the first hydrocracking effluent from the first hydrocracking step f) and a gas stream comprising hydrogen, said hydrocracking reaction section being implemented at an average temperature between 250 and 450°C, a partial pressure of hydrogen between 1.5 and 20.0 Mpa abs. and an hourly volumetric velocity between 0.1 and 10.0 h- 1, to obtain a second hydrocracked effluent. The preferred operating conditions and catalysts used in the second hydrocracking stage are those described for the first hydrocracking stage. The operating conditions and catalysts used in the two hydrocracking stages may be the same or different.

[0229] Said second hydrocracking step is preferably carried out in a hydrocracking reaction section comprising at least one, preferably between one and five, fixed bed reactor(s) having n catalytic beds, n being an integer greater than or equal to one, preferably between one and ten, more preferably between two and five, said bed(s) each comprising at least one, and preferably not more than ten, hydrocracking catalyst(s). These operating conditions used in the hydrocracking step(s) generally make it possible to achieve conversions per pass, into products having at least 80% by volume of compounds having boiling points less than or equal to 175°C, preferably less than 160°C and more preferably less than 150°C, and greater than 15% by weight and even more preferably between 20 and 95% by weight.When the process is carried out in two hydrocracking stages, the conversion per pass in the second stage is kept moderate in order to maximize the selectivity for compounds of the naphtha cut (having a boiling point less than or equal to 175°C, in particular between 80 and less than or equal to 175°C). The conversion per pass is limited by the use of a high recycle rate on the loop of the second hydrocracking stage. This rate is defined as the ratio between the feed flow rate of stage f') and the flow rate of the feed of stage b), preferably this ratio is between 0.2 and 4, more preferably between 0.5 and 2.5.

[0230] The hydrocracked effluent from the second hydrocracking stage f') may at least partly be recycled into stages b), c), d) or e).

[0231] The hydrocracking step(s) thus do not necessarily allow all the hydrocarbon compounds of the middle distillate cut to be transformed into hydrocarbon compounds having a boiling point less than or equal to 175°C (naphtha cut). After the fractionation step e), there may therefore remain a more or less significant proportion of compounds having a boiling point above 175°C. At least a portion of this unconverted cut may be introduced into a second hydrocracking step f'). Another portion may be purged. Depending on the operating conditions of the process, said purge may be between 0 and 10% by weight of the cut comprising compounds having a boiling point above 175°C relative to the incoming feed, and preferably between 0.5% and 5% by weight.

[0232] According to the invention, the hydrocracking step(s) operate in the presence of at least one hydrocracking catalyst.

[0233] The hydrocracking catalyst(s) used in the hydrocracking step(s) are conventional hydrocracking catalysts known to those skilled in the art, of the bifunctional type combining an acid function with a hydro-dehydrogenating function and optionally at least one binding matrix. The acid function is provided by supports with a large surface area (150 to 800 m 2 / g generally) having a surface acidity, such as halogenated aluminas (chlorinated or fluorinated in particular), combinations of boron and aluminum oxides, amorphous silica-aluminas and zeolites. The hydro-dehydrogenating function is provided by at least one metal from group VI B of the periodic table and / or at least one metal from group VIII. Preferably, the hydrocracking catalyst(s) comprise a hydro-dehydrogenating function comprising at least one metal from group VIII chosen from iron, cobalt, nickel, ruthenium, rhodium, palladium and platinum, and preferably from cobalt and nickel. Preferably, said catalyst(s) also comprise at least one metal from group VI B chosen from chromium, molybdenum and tungsten, alone or as a mixture, and preferably from molybdenum and tungsten. Hydro-dehydrogenating functions of the NiMo, NiMoW, NiW type are preferred.

[0234] Preferably, the content of group VIII metal in the hydrocracking catalyst(s) is advantageously between 0.5 and 15% by weight and preferably between 1 and 10% by weight, the percentages being expressed as a percentage by weight of oxides relative to the total weight of the catalyst. When the metal is cobalt or nickel, the metal content is expressed as CoO and NiO respectively.

[0235] Preferably, the content of group VI B metal in the hydrocracking catalyst(s) is advantageously between 5 and 35% by weight, and preferably between 10 and 30% by weight, the percentages being expressed as a percentage by weight of oxides relative to the total weight of the catalyst. When the metal is molybdenum or tungsten, the metal content is expressed as MoOa and WO3 respectively.

[0236] The hydrocracking catalyst(s) may also optionally comprise at least one promoter element deposited on the catalyst and selected from the group formed by phosphorus, boron and silicon, optionally at least one element from group VI IA (chlorine, fluorine preferred), optionally at least one element from group VI IB (manganese preferred), and optionally at least one element from group VB (niobium preferred).

[0237] Preferably, the hydrocracking catalyst(s) comprise at least one amorphous or poorly crystallized porous mineral matrix of oxide type chosen from aluminas, silicas, silica-aluminas, aluminates, alumina-boron oxide, magnesia, silica-magnesia, zirconia, titanium oxide, clay, alone or as a mixture, and preferably aluminas or silica-aluminas, alone or as a mixture.

[0238] Preferably, the silica-alumina contains more than 50% by weight of alumina, preferably more than 60% by weight of alumina.

[0239] Preferably, the hydrocracking catalyst(s) also optionally comprise a zeolite chosen from Y zeolites, preferably from USY zeolites, alone or in combination, with other zeolites from beta zeolites, ZSM-12, IZM-2, ZSM-22, ZSM-23, SAPO-11, ZSM-48, ZBM-30, alone or as a mixture. Preferably, the zeolite is USY zeolite alone. In the case where said catalyst comprises a zeolite, the zeolite content in the hydrocracking catalyst(s) is advantageously between 0.1 and 80% by weight, preferably between 3 and 70% by weight, the percentages being expressed as a percentage of zeolite relative to the total weight of the catalyst.

[0240] A preferred catalyst comprises, and preferably consists of, at least one Group VIB metal and optionally at least one non-noble Group VIII metal, at least one promoter element, and preferably phosphorus, at least one Y zeolite and at least one alumina binder.

[0241] An even more preferred catalyst comprises, and preferably consists of, nickel, molybdenum, phosphorus, a USY zeolite, and optionally also a beta zeolite, and alumina.

[0242] Another preferred catalyst comprises, and preferably consists of, nickel, tungsten, alumina and silica-alumina.

[0243] Another preferred catalyst comprises, and preferably consists of, nickel, tungsten, USY zeolite, alumina and silica-alumina.

[0244] Said hydrocracking catalyst is for example in the form of extrudates.

[0245] In one variant, the hydrocracking catalyst used in the second hydrocracking step comprises a hydro-dehydrogenating function comprising at least one noble metal from group VIII chosen from palladium and platinum, alone or as a mixture. The content of noble metal from group VIII is advantageously between 0.01 and 5% by weight and preferably between 0.05 and 3% by weight, the percentages being expressed as a percentage by weight of oxides (PtO or PdO) relative to the total weight of the catalyst.

[0246] According to another aspect of the invention, the hydrocracking catalysts as described above further comprise one or more organic compounds containing oxygen and / or nitrogen and / or sulfur as described above (additive catalyst).

[0247] Said hydrocarbon effluent or said hydrocarbon fraction(s) thus obtained by treatment according to the process of the invention, has a composition compatible with the specifications of an input feedstock of a steam cracking unit. In particular, the composition of the hydrocarbon effluent or said hydrocarbon fraction(s) resulting from the process is preferably such that:

[0248] - the total content of metallic elements is less than or equal to 10.0 ppm by weight, preferably less than or equal to 2.0 ppm by weight, preferentially less than or equal to 1.0 ppm by weight and preferably less than or equal to 0.8 ppm by weight, with: a content of silicon element (Si) less than or equal to 5.0 ppm by weight, preferably less than or equal to 1 ppm by weight, and preferably less than or equal to 0.6 ppm by weight and a content of iron element (Fe) less than or equal to 200 ppb by weight,

[0249] - the sulfur content is less than or equal to 500 ppm by weight, preferably less than or equal to 200 ppm by weight,

[0250] - the nitrogen content is less than or equal to 100 ppm by weight, preferably less than or equal to 50 ppm by weight, preferably less than or equal to 10 ppm by weight, and particularly preferably less than or equal to 5 ppm by weight

[0251] - the total chlorine element content is less than or equal to 5.0 ppm by weight, preferably less than 1.0 ppm by weight,

[0252] - the content of olefinic compounds (mono- and di-olefins) is less than or equal to 5.0% by weight, preferably less than or equal to 2.0% by weight, more preferably less than or equal to 0.1% by weight.

[0253] - the mercury content is less than or equal to 5 ppb by weight, preferably less than 3 ppb by weight.

[0254] The contents are given in relative weight concentrations, percentage (%) by weight, part(s) per million (ppm) by weight or part(s) per billion (ppb) by weight, relative to the total weight of the stream considered.

[0255] The process according to the invention therefore makes it possible to treat pyrolysis oils to obtain at least one effluent which can be injected, in whole or in part, into at least one steam cracking unit.

[0256] Step g) of steam cracking (optional)

[0257] At least a portion of the effluent from step d) when the separation step d) is carried out after step c), and / or at least a portion of the hydrotreated effluent from step c) when the separation step d) is carried out between steps b) and c) and / or at least one of the liquid hydrocarbon cuts from the optional fractionation step e), may be sent in whole or in part to a steam cracking step g).

[0258] Advantageously, the gaseous effluent(s) from separation step d) and / or fractionation step e) and containing ethane, propane and butane, may also be sent in whole or in part to steam cracking step g). Said steam cracking step g) is advantageously carried out in at least one pyrolysis furnace at a temperature of between 700 and 900°C, preferably between 750 and 850°C, and at a pressure of between 0.05 and 0.3 MPa relative. The residence time of the hydrocarbon compounds is generally less than or equal to 1.0 seconds (denoted s), preferably between 0.1 and 0.5 s. Advantageously, water vapor is introduced upstream of the optional steam cracking step g) and after the separation (or fractionation). The quantity of water introduced, advantageously in the form of water vapor, is advantageously between 0.3 and 3.0 kg of water per kg of hydrocarbon compounds entering step g).Preferably, the optional step g) is carried out in several pyrolysis furnaces in parallel so as to adapt the operating conditions to the different streams feeding step g), in particular from step e), and also to manage the decoking times of the tubes. A furnace comprises one or more tubes arranged in parallel. A furnace can also designate a group of furnaces operating in parallel. For example, a furnace can be dedicated to the cracking of the middle distillate cut.

[0259] The effluents from the various steam cracking furnaces are generally recombined before separation in order to constitute an effluent. It is understood that the steam cracking step g) comprises the steam cracking furnaces but also the sub-steps associated with steam cracking well known to those skilled in the art. These sub-steps may include in particular heat exchangers, columns and catalytic reactors and recycles to the furnaces. A column generally makes it possible to fractionate the effluent in order to recover at least a light fraction comprising hydrogen and compounds having 2 to 5 carbon atoms, and a fraction comprising pyrolysis gasoline, and possibly a heavier fraction. Columns make it possible to separate the different constituents of the light fractionation fraction in order to recover at least one cut rich in ethylene (C2 cut) and a cut rich in propylene (C3 cut) and possibly a cut rich in butenes (C4 cut).Catalytic reactors are used in particular to carry out hydrogenation of C2, C3 and even C4 cuts and pyrolysis gasoline. Saturated compounds, particularly saturated compounds with 2 to 4 carbon atoms, are advantageously recycled to steam cracking furnaces in order to increase overall olefin yields.

[0260] This steam cracking step g) makes it possible to obtain at least one effluent containing olefins comprising 2, 3 and / or 4 carbon atoms (i.e. C2, C3 and / or C4 olefins), at satisfactory contents, in particular greater than or equal to 30% by weight, in particular greater than or equal to 40% by weight, or even greater than or equal to 50% by weight of total olefins comprising 2, 3 and 4 carbon atoms relative to the weight of the steam cracking effluent in question. Said C2, C3 and C4 olefins can then be advantageously used as polyolefin monomers.

[0261] (Optional) heavy metal adsorption step

[0262] Any gaseous effluent and / or any liquid effluent from at least one of the separation steps d) or from the fractionation step e) may be subjected to an optional heavy metal adsorption step.

[0263] The optional adsorption step makes it possible to eliminate or reduce the quantity of metallic impurities, in particular the quantity of heavy metals such as arsenic, zinc, lead, and in particular mercury, possibly present in said gaseous and liquid effluents. The metallic impurities, and in particular the heavy metals, are present in the feedstock. Certain impurities, in particular mercury-based, can be transformed in one of the steps of the process according to the invention. Their transformed form is easier to trap. Their elimination or reduction may in particular be necessary when at least part of said gaseous and liquid effluents is intended to be sent, either directly or after having undergone one or more optional additional steps such as the fractionation step e), to a step having severe metallic impurity specifications, such as a steam cracking step.

[0264] Thus, an optional step of adsorption of a gaseous effluent and / or a hydrocarbon effluent from the process according to the invention is advantageously carried out in particular when at least one of these effluents or the feed respectively comprises more than 20 ppb by weight, in particular more than 15 ppb by weight of heavy metal metallic elements (As, Zn, Pb, Hg, etc.), and in particular when at least one of these effluents or the feed respectively comprises more than 10 ppb by weight of mercury, more particularly more than 15 ppb by weight of mercury.

[0265] Said optional adsorption step is advantageously carried out at a temperature between 20 and 250°C, preferably between 40 and 200°C, and at a pressure between 0.15 and 10.0 MPa abs, preferably between 0.2 and 1.0 MPa abs.

[0266] Said optional adsorption step can be implemented by any adsorbent known to those skilled in the art making it possible to reduce the quantity of such contaminants.

[0267] According to a variant, said optional adsorption step is implemented in an adsorption section operated in the presence of at least one adsorbent comprising a porous support, and optionally at least one active phase which may be based on sulfur in elemental form, or in the form of metal sulfide or metal oxide, or even in metallic form in elemental form.

[0268] The porous support can be chosen indifferently from the families of aluminas, silica-aluminas, silicas, zeolites and / or activated carbons. Advantageously, the porous support is based on alumina

[0269] Said adsorption section may comprise one or more adsorption columns. When the adsorption section comprises two adsorption columns, one operating mode may be a so-called "swing" operation, in which one of the columns is online, i.e. in operation, while the other column is in reserve. Another operating mode is to have at least two columns operating in series in a switchable mode.

[0270] Preferably, said adsorption section comprises an adsorption column for the gaseous effluent(s) and an adsorption column for the liquid effluent(s).

[0271] ANALYSIS METHODS USED

[0272] The analysis methods and / or standards used to determine the characteristics of the various flows, in particular the load to be treated and the effluents, are known to those skilled in the art. They are listed below for information purposes. Other methods deemed equivalent may also be used, in particular equivalent IP, EN or ISO methods:

[0273] Table 1

[0274] (1) MAV method described in the article: C. Lôpez-Garcia et al., Near Infrared Monitoring of Low Conjugated Diolefins Content in Hydrotreated FCC Gasoline Streams, Oil & Gas Science and Technology - Rev. IFP, Vol. 62 (2007), No. 1, pp. 57-68.

[0275] LIST OF FIGURES

[0276] The mention of the elements referenced in Figures 1 to 4 allows a better understanding of the invention, without it being limited to the particular embodiments illustrated in Figures 1 to 4. The different embodiments presented can be used alone or in combination with each other, without limitation of combination.

[0277] Figures 1 and 2 refer to the embodiment in which separation step d) is carried out after hydrotreatment step c). Figures 3 and 4 refer to the embodiment in which separation step d) is carried out between hydrogenation step b) and hydrotreatment step c).

[0278] Figure 1 represents the diagram of a particular embodiment of the method of the present invention, comprising:

[0279] - a step a) of selective hydrogenation (optional) of a feedstock 1 comprising at least 5% by weight of a tire pyrolysis oil relative to the total weight of the feedstock, said tire pyrolysis oil having a sulfur content of between 2000 and 10000 ppm by weight relative to the total weight of the oil, in the presence of a hydrogen-rich gas 2, to obtain a selectively hydrogenated effluent 3;

[0280] - a step b) of hydrogenation of said selectively hydrogenated effluent 3 from step a) in the presence of a hydrogen-rich gas 4 and optionally an amine supplied by stream 5 and optionally a sulfurizing agent by stream 6, to obtain a hydrogenated effluent 7;

[0281] - a step c) hydrotreatment supplied by the hydrogenated effluent 7 from step b) hydrogenation and by a flow of a hydrogen-rich gas 8, to obtain a hydrotreated effluent 9;

[0282] - a separation step d) supplied with the effluent 9 from the hydrotreatment step c) and in the presence of an aqueous solution 12 to obtain at least one gaseous effluent 13, one aqueous effluent 14 and one hydrocarbon effluent 15.

[0283] Figure 2 represents the diagram of another particular embodiment of the process of the present invention which is based on the diagram of Figure 1. This diagram comprises a step d) carried out in two stages, steps d1) and d2), then a step e) of fractionation and a step f) of hydrocracking in addition.

[0284] The elective hydrogenation step a) (optional), the hydrogenation step b) and the hydrotreatment step c) are carried out as described in Figure 1. The separation step d), carried out in two stages, includes in particular:

[0285] - a step d1) of separation of the hydrotreated effluent 9 carried out at high pressure and high temperature (HH PS) to obtain at least a first gaseous effluent 10 and a liquid effluent 11 of which a part 11a can be recycled upstream of step b) or upstream of step a) (not shown),

[0286] - a separation step d2) carried out at high pressure and low temperature (CH PS) and supplied with the gaseous effluent 10 and the other part of the liquid effluent 11b from step d1) and an aqueous solution 12 and making it possible to obtain at least one gaseous effluent 13 comprising hydrogen, an aqueous effluent 14 containing dissolved salts and dissolved H2S and NHs, and a hydrocarbon effluent 15; Optionally, a step e) of fractionation of the effluent 15 is carried out making it possible to obtain at least one gaseous effluent 16, a naphtha cut 17 and a middle distillate cut 18.

[0287] At the end of step e), a portion of the naphtha cut 17 may be sent to a steam cracking process (not shown). Another portion of the naphtha cut 17 may feed the selective hydrogenation step a), the hydrogenation step b) and / or the hydrotreatment step c) (recycling not shown).

[0288] In Figure 2, at least a portion of middle distillate cut 18 from step e) feeds a hydrocracking step f) which is carried out in at least one fixed-bed reactor comprising at least one hydrocracking catalyst and is supplied with hydrogen 19. The hydrocracked effluent 20 can be recycled between separation steps d1) and d2) or upstream of separation step d) (not shown).

[0289] Figure 3 represents the diagram of a particular embodiment of the method of the present invention, comprising:

[0290] - a step a) of selective hydrogenation (optional) of a feedstock 1 comprising at least 5% by weight of a tire pyrolysis oil relative to the total weight of the feedstock, said tire pyrolysis oil having a sulfur content of between 2000 and 10000 ppm by weight relative to the total weight of the oil, in the presence of a hydrogen-rich gas 2, to obtain a selectively hydrogenated effluent 3;

[0291] - a step b) of hydrogenation of said selectively hydrogenated effluent 3 from step a) in the presence of a hydrogen-rich gas 4 and optionally an amine supplied by stream 5 and optionally a sulfurizing agent by stream 6, to obtain a hydrogenated effluent 7;

[0292] - a separation step d) supplied with the hydrogenated effluent 7 from the hydrogenation step b) and in the presence of an aqueous solution 12 to obtain at least one gaseous effluent 13, one aqueous effluent 14 and one washed hydrocarbon effluent 23 freed in particular from chlorine impurities.

[0293] - a hydrotreatment step c) fed by the washed hydrogenated effluent 23 freed in particular from chlorine impurities from separation step d) and by a flow of a hydrogen-rich gas 8, to obtain a hydrotreated hydrocarbon effluent 15. Figure 4 represents the diagram of another particular embodiment of the process of the present invention which is based on the diagram of figure 3. This diagram comprises a step d) carried out in two stages, steps d1) and d2), then a fractionation step e) and a hydrocracking step f) in addition.

[0294] Selective hydrogenation step a) (optional) and hydrogenation step b) are carried out as described in Figure 3. Separation step d), carried out in two stages, includes in particular:

[0295] - a step d1) of separation of the hydrogenated effluent 7 carried out at high pressure and high temperature (HH PS) to obtain at least a first gaseous effluent 21 and a liquid effluent 22 of which a part 22a can be recycled upstream of step b) or upstream of step a) (not shown),

[0296] - a separation step d2) carried out at high pressure and low temperature (CH PS) and supplied with the gaseous effluent 21 and the other part of the liquid effluent 22b from step d1) and an aqueous solution 12 and making it possible to obtain at least a second gaseous effluent 13 comprising hydrogen, an aqueous effluent 14 containing dissolved salts and dissolved H2S and NHs, and a washed hydrocarbon effluent 23;

[0297] - a step c) hydrotreatment supplied by the washed hydrocarbon effluent 23 freed in particular from the chlorine impurities from the separation step d) and by a flow of a hydrogen-rich gas 8, to obtain a hydrotreated hydrocarbon effluent 15.

[0298] Optionally, a step e) of fractionation of the hydrotreated hydrocarbon effluent 15 is carried out, making it possible to obtain at least one gaseous effluent 16, a naphtha cut 17 and a middle distillate cut 18.

[0299] At the end of step e), a portion of the naphtha cut 17 may be sent to a steam cracking process (not shown). Another portion of the naphtha cut 17 may feed the selective hydrogenation step a), the hydrogenation step b) and / or the hydrotreatment step c) (recycling not shown).

[0300] In Figure 4, at least a portion of middle distillate cut 18 from step e) feeds a hydrocracking step f) which is carried out in at least one fixed-bed reactor comprising at least one hydrocracking catalyst and is supplied with hydrogen 19. The hydrocracked effluent 20 can be recycled between separation steps d1) and d2) or upstream of separation step d) (not shown).

[0301] Only the main steps, with the main flows, are shown in Figures 1 to 4, in order to allow a better understanding of the invention. It is understood that all the equipment necessary for operation is present (tanks, pumps, exchangers, furnaces, columns, etc.), even if not shown. It is also understood that hydrogen-rich gas flows (make-up or recycle), as described above, can be injected at the inlet of each reactor or catalytic bed or between two reactors or two catalytic beds. Means well known to those skilled in the art for purifying and recycling hydrogen can also be implemented.

[0302] EXAMPLES

[0303] Example 1 (in accordance with the invention)

[0304] The feedstock treated in the process with a flow rate of 10000 kg / h (10 T / h) is a tire pyrolysis oil (i.e. comprising 100% by weight of said tire pyrolysis oil) having the characteristics indicated in Table 2.

[0305] Table 2: Load characteristics

[0306] The feedstock is mixed with a liquid recycle, i.e. a portion of the liquid effluent from a hot drum from separation step d), in proportions 80 / 20 by mass, i.e. 40 T / h of liquid recycle for 10 T / h of feedstock. The mixture obtained is subjected to a hydrogenation step b) carried out in a fixed-bed reactor and in the presence of hydrogen and a NiMo-on-alumina hydrogenation catalyst under the conditions indicated in Table 3.

[0307] Table 3: Conditions for hydrogenation step b)

[0308] The conditions indicated in Table 3 correspond to cycle start conditions.

[0309] At the end of hydrogenation step b), the conversion rates (= (initial concentration - final concentration) / initial concentration) observed are indicated in Table 4.

[0310] Table 4: Conversions of species during step b) of hydrogenation

[0311] The effluent from hydrogenation step b) is subjected directly, without separation, to a hydrotreatment step b) carried out in a fixed bed and in the presence of hydrogen and a NiMo-on-alumina hydrotreatment catalyst under the conditions presented in table 5. Table 5: conditions of hydrotreatment step c)

[0312] The conditions indicated in Table 5 correspond to cycle start conditions.

[0313] The effluent from hydrotreatment step c) is subjected to a separation step d) comprising a separation step d1) and a separation step d2). The effluent from hydrotreatment step c) is subjected to separation step d1) comprising a high-pressure separator drum operated at 300°C and 5.2 MPa abs. The fraction obtained at the bottom of the high-pressure hot drum allows, via a pump, the recycling of part of the effluent to the inlet of hydrogenation step b). The fraction obtained at the top of the high-pressure hot drum is mixed with the part obtained at the bottom of the high-pressure hot drum which is not recycled to the inlet of hydrogenation step b). This hydrocarbon mixture is subjected to separation step d2) into which a water stream is injected.The hydrocarbon mixture and the water stream are then treated in an acid gas scrubbing column and separator drums to obtain a gas fraction, an aqueous effluent comprising salts and a liquid effluent. The yields and quality of the different fractions obtained after separation are indicated in Table 6 (the yields correspond to the ratios of the mass quantities of the different products obtained relative to the mass of feed upstream of step b), expressed as a percentage and noted % m / m).

[0314] Table 6: Yields and quality of the different products obtained after separation

[0315] All or part of the liquid fraction obtained can then be used in a steam cracking stage to form olefins which can be polymerized to form recycled plastics.

[0316] The tire pyrolysis oil feedstock contains a lot of sulfur (4892 ppm by weight). This sulfur, which is in the form of sulfur molecules, is hydrogenated in the reaction section and is transformed into hydrogen sulfide H2S. This H2S, in the form of a partial pressure of H2S (PPH2S) of 0.019 MPa abs at the outlet of the hydrotreatment reactor, contributes to maintaining the sulfide phase of the NiMo-on-alumina catalysts and therefore to the catalyst activity. As a result, the loss of catalytic activity in hydrotreatment step c) is low (< 1°C per month) and it is not necessary to inject hydrogen sulfide or a sulfur compound such as DMDS to maintain catalytic activity.

[0317] Example 2 (in accordance with the invention)

[0318] The feedstock treated in the process with a flow rate of 10000 kg / h (10 T / h) is a 6 / 94 m / m mixture of tire pyrolysis oil from Example 1 and plastic pyrolysis oil (i.e. comprising 6% by weight of said tire pyrolysis oil and 94% by weight of said plastic pyrolysis oil) having the characteristics indicated in Table 7. Table 7: Feedstock characteristics

[0319] The feedstock is mixed with a liquid recycle, i.e. a portion of the liquid effluent from a hot drum from separation step d), in the proportions 80 / 20 by mass, i.e. 40 T / h of liquid recycle for 10 T / h of feedstock. The mixture obtained is subjected to a hydrogenation step b) carried out in a fixed bed reactor and in the presence of hydrogen and a NiMo-on-alumina hydrogenation catalyst under the conditions indicated in Table 8.

[0320] Table 8: Conditions for hydrogenation step b)

[0321] The conditions indicated in Table 8 correspond to cycle start conditions.

[0322] At the end of hydrogenation step b), the conversion rates (= (initial concentration - final concentration) / initial concentration) observed are indicated in Table 9.

[0323] Table 9: Conversions of species during step b) of hydrogenation

[0324] The effluent from hydrogenation step b) is subjected directly, without separation, to a hydrotreatment step b) carried out in a fixed bed and in the presence of hydrogen and a NiMo-on-alumina hydrotreatment catalyst under the conditions presented in table 10. Table 10: conditions of hydrotreatment step c) The conditions indicated in Table 10 correspond to cycle start conditions.

[0325] The effluent from hydrotreatment step c) is subjected to a separation step d) comprising a separation step d1) and a separation step d2). The effluent from hydrotreatment step c) is subjected to separation step d1) comprising a high-pressure separator drum operated at 300°C and 5.2 MPa abs. The fraction obtained at the bottom of the high-pressure hot drum allows, via a pump, the recycling of part of the effluent to the inlet of hydrogenation step b). The fraction obtained at the top of the high-pressure hot drum is mixed with the part obtained at the bottom of the high-pressure hot drum which is not recycled to the inlet of hydrogenation step b). This hydrocarbon mixture is subjected to separation step d2) into which a water stream is injected.The hydrocarbon mixture and the water stream are then treated in an acid gas scrubbing column and separator drums to obtain a gas fraction, an aqueous effluent comprising salts and a liquid effluent. The yields and quality of the different fractions obtained after separation are indicated in Table 11 (the yields correspond to the ratios of the mass quantities of the different products obtained relative to the mass of feed upstream of step b), expressed as a percentage and noted % m / m).

[0326] Table 11: Yields and quality of the different products obtained after separation

[0327] All or part of the liquid fraction obtained can then be used in a steam cracking step to form olefins that can be polymerized to form recycled plastics. The feedstock consisting of the mixture of plastic pyrolysis oil and tire pyrolysis oils has a significant sulfur content (355 ppm by weight). This sulfur, which is in the form of sulfur molecules, is hydrogenated in the reaction section and is transformed into hydrogen sulfide H2S. This H2S, in the form of a partial pressure of H2S (ppH2S) of 0.0027 MPa abs at the outlet of the hydrotreatment reactor, contributes to maintaining the sulfide phase of the NiMo catalysts on alumina and therefore to the activity of the catalyst. As a result, the loss of catalytic activity in hydrotreatment step c) is low (< 1°C month) and there is no need to inject hydrogen sulfide or a sulfur compound such as DMDS to maintain catalytic activity.

[0328] Example 3 (not in accordance with the invention)

[0329] According to Example 3, the treated feedstock is a plastic pyrolysis oil (i.e. comprising 100% by weight of said plastic pyrolysis oil) having the characteristics indicated in Table 12. Table 12: Characteristics of the feedstock The plastic pyrolysis oil according to Example 3 is treated under the same conditions as tire pyrolysis oil according to Example 1.

[0330] The plastic pyrolysis oil feedstock contains very little sulfur (67 ppm by weight). This sulfur, which is in the form of sulfur molecules, is hydrogenated in the reaction section and is transformed into H2S. This H2S, in the form of a partial pressure of H2S (ppH2S) of 0.0004 MPa abs at the outlet of the hydrotreatment reactor, partially contributes to maintaining the sulfide phase of the NiMo-on-alumina catalysts. However, the ppH2S obtained with this sulfur content in the feedstock (67 ppm by weight) is insufficient to maintain the catalysts in the sulfide phase throughout the cycle. This results in a rapid deactivation of the catalyst activity.

[0331] Example 4 (not in accordance with the invention)

[0332] According to Example 4, the treated feedstock is identical to the plastic pyrolysis oil treated in Example 3. The feedstock according to Example 4 is treated under the same conditions as in Example 3 but H2S is added to the reaction system in order to achieve a sufficient ppH2S. This addition of H2S can be done in the form of an injection at the inlet of the unit into the dimethyl disulfide (DMDS) pyrolysis oil feedstock. DMDS decomposes easily upon contact with the catalyst into ChL and H2S, thus generating a sufficient ppH2S to maintain the catalysts in sulfide form. This method results in a high consumption of DMDS which is detrimental to the economy of the process.

[0333] Given the sulfur content of the feedstock, the DMDS is injected at a content of 800 ppm (content equivalent to 544 ppm by weight of sulfur) so as to achieve the same partial pressure of hydrogen sulfide as that obtained in example 2, i.e. 0.0027 MPa abs. For a capacity of 10 T / h of treated feedstock, this represents a DMDS consumption of 8.0 kg / h and therefore a significant operating and environmental cost.

[0334] Example 5 (not in accordance with the invention)

[0335] According to Example 5, the treated feedstock is identical to the plastic pyrolysis oil treated in Example 3 except for having a very high chlorine content (2000 ppm by weight) and a nitrogen content of 700 ppm by weight. The plastic pyrolysis oil according to Example 5 is treated under the same conditions as the tire pyrolysis oil according to Example 3. An injection of 16.5 kg / h of aniline is necessary in order to capture all the Cl ions.

[0336] Example 6 (in accordance with the invention)

[0337] According to Example 6, the treated feedstock is a mixture comprising 15% by weight of tire pyrolysis oil from Example 1 (with a nitrogen content of 2720 ppm by weight) and 85% by weight of plastic pyrolysis oil from Example 5 (with a sulfur content of 2000 ppm by weight and 700 ppm by weight of nitrogen). The feedstock according to Example 6 is treated under the same conditions as the feedstock (100% by weight of plastic oil) according to Example 5. It is not necessary to inject an amine since the tire pyrolysis oil provides the nitrogen necessary to capture all the Cl ions. In addition, it is not necessary to inject hydrogen sulfide or a sulfur compound such as DMDS to maintain the catalytic activity.

Claims

CLAIMS 1. A method for treating a feedstock comprising at least 5% by weight of a tire pyrolysis oil relative to the total weight of the feedstock, said tire pyrolysis oil having a sulfur content of between 2000 and 10000 ppm by weight relative to the total weight of the oil, said method comprising the following steps: a) optionally a selective hydrogenation step carried out in a reaction section using at least one fixed-bed reactor having n catalytic beds, n being an integer greater than or equal to 1, each comprising at least one selective hydrogenation catalyst, said selective hydrogenation reaction section being supplied at least by said feedstock and a gas stream comprising hydrogen, in the presence of at least one selective hydrogenation catalyst, at an average temperature between 100 and 280°C, a hydrogen partial pressure between 1.0 and 10.0 MPa abs. and an hourly volumetric velocity between 0.1 and 10.0 h'1 , to obtain a selectively hydrogenated effluent; b) a hydrogenation step carried out in a hydrogenation reaction section, using at least one fixed-bed reactor having n catalytic beds, n being an integer greater than or equal to 1, each comprising at least one hydrogenation catalyst, said hydrogenation reaction section being fed at least with said feedstock or said selectively hydrogenated effluent from step a) and a gas stream comprising hydrogen, said hydrogenation reaction section being carried out at an average temperature between 140 and 400°C, a partial pressure of hydrogen between 1.0 and 10.0 MPa abs. and an hourly volumetric flow rate between 0.1 and 10.0 h -1, to obtain a hydrogenated effluent, c) a hydrotreatment step carried out in a hydrotreatment reaction section, using at least one fixed-bed reactor having n catalytic beds, n being an integer greater than or equal to 1, each comprising at least one hydrotreatment catalyst, said hydrotreatment reaction section being fed at least by said hydrocarbon effluent from step d) when the separation step d) is carried out between steps b) and c), and / or at least by the hydrogenated effluent from step b) when the separation step d) is carried out after step c), and a gas stream comprising hydrogen, said hydrotreatment reaction section being carried out at an average temperature between 250 and 430°C, a hydrogen partial pressure between 1.0 and 10.0 MPa abs. and an hourly volumetric velocity between 0.1 and 10.0 h' 1 , to obtain a hydrotreated effluent, d) a separation step, carried out between steps b) and c) and / or after step c), said step being fed with the hydrogenated effluent from step b) when separation step d) is carried out between steps b) and c), and / or with the hydrotreated effluent from step c) when separation step d) is carried out after step c), and an aqueous solution, said step being carried out in a separation section, to obtain at least one gaseous effluent, one aqueous effluent and one hydrocarbon effluent.

2. A method according to claim 1, wherein the feedstock comprises plastic pyrolysis oil and / or solid recovered fuels.

3. Method according to one of the preceding claims, in which the feedstock consists of a tire pyrolysis oil and plastic pyrolysis oil(s) and / or solid recovered fuels.

4. Method according to one of the preceding claims, in which the feedstock comprises a tire pyrolysis oil in a content of between 5 and 99% by weight and a plastic pyrolysis oil and / or solid recovered fuels in a content of between 1 and 95% by weight relative to the total weight of the feedstock.

5. Method according to one of the preceding claims, in which the separation step d) comprises the following steps: d1) a separation step, fed with the hydrogenated effluent from step b) when the separation step d) is carried out between steps b) and c), and / or with the hydrotreated effluent from step c) when the separation step d) is carried out after step c), said step being carried out at a temperature higher than the precipitation temperature of the ammonium halides and at a pressure substantially identical to the pressure of step b) to obtain at least a first gaseous effluent and a liquid effluent, a part of which is optionally recycled, as recycled effluent, upstream of step b), d2) a separation step, fed with the first gaseous effluent and optionally at least a part of the liquid effluent from step d 1 ), and an aqueous solution,said step being carried out at a temperature lower than the precipitation temperature of the ammonium halides and at a pressure substantially identical to or lower than the pressure of step b), to obtain at least a second gaseous effluent, an aqueous effluent and a hydrocarbon effluent., 6. Method according to the preceding claim, in which step d1) is carried out at a temperature between 200 and 450°C and step d2) is carried out at a temperature greater than or equal to 20°C and less than 200°C.

7. Method according to one of the preceding claims, comprising at least one step of pretreatment of the feedstock comprising a tire pyrolysis oil, said pretreatment step being carried out upstream of step a) and / or upstream of step b) and comprises an adsorption step and / or a filtration step and / or a centrifugation step and / or a decantation step and / or an electrostatic separation step and / or a step of washing using an aqueous solution and / or a gas stripping step.

8. Process according to one of the preceding claims, comprising a step e) of fractionation of all or part of the hydrocarbon effluent from step d) when the separation step d) is carried out after step c), and / or of all or part of the hydrotreated effluent from step c) when the separation step d) is carried out between steps b) and c), to obtain at least one gas stream, a naphtha cut and at least one middle distillate cut.

9. Process according to one of the preceding claims, comprising at least one hydrocracking step f) carried out in a hydrocracking reaction section, using at least one fixed-bed reactor having n catalytic beds, n being an integer greater than or equal to 1, each comprising at least one hydrocracking catalyst, said hydrocracking reaction section being fed with at least a portion of said hydrocarbon effluent from step d) when the separation step d) is carried out after step c), and / or with at least a portion of the hydrotreated effluent from step c) when the separation step d) is carried out between steps b) and c), and / or with at least a portion of the middle distillate cut from the fractionation step e) and a gas stream comprising hydrogen, said hydrocracking reaction section being carried out at an average temperature between 250 and 450°C, a partial pressure of hydrogen between 1 ,5 and 20.0 MPa abs. and an hourly volumetric flow rate between 0.1 and 10.0 h, -1 to obtain a first hydrocracked effluent.

10. Process according to one of the preceding claims, in which said hydrogenation catalyst of step b) comprises a support chosen from alumina, silica, silica-aluminas, magnesia, clays and their mixtures and a hydro-dehydrogenating function comprising either at least one element from group VIII and at least one element from group VIB, or at least one element from group VIII.

11. Method according to one of the preceding claims, in which said hydrotreatment catalyst of step c) comprises a support chosen from alumina, silica, silica-aluminas, magnesia, clays and their mixtures, and a hydro-dehydrogenating function comprising at least one element from group VIII and / or at least one element from group VIB.

12. Process according to one of the preceding claims, in which at least a portion of the hydrocarbon effluent from step d) when the separation step d) is carried out after step c), and / or at least a portion of the hydrotreated effluent from step c) when the separation step d) is carried out between steps b) and c) and / or at least one of the cuts from the fractionation step e) is sent to a steam cracking step g) carried out in at least one pyrolysis furnace at a temperature of between 700 and 900°C and at a pressure of between 0.05 and 0.3 MPa relative.

13. Process according to one of the preceding claims comprising step a) of selective hydrogenation.

14. Process according to the preceding claim, in which said selective hydrogenation catalyst of step a) comprises a support chosen from alumina, silica, silica-aluminas, magnesia, clays and mixtures thereof, and a hydro-dehydrogenating function comprising at least one element from group VIII and / or at least one element from group VI B.

15. Product obtained by the process according to one of claims 1 to 14.

16. Product according to claim 15, which comprises, relative to the total weight of the product: - a total content of metallic elements less than or equal to 10.0 ppm by weight, - with an iron element content of less than or equal to 200 ppb by weight, and / or - a silicon element content less than or equal to 5.0 ppm by weight, and / or - a sulfur content less than or equal to 100 ppm by weight, and / or - a nitrogen content less than or equal to 100 ppm by weight, and / or - a chlorine element content of less than or equal to 10 ppm by weight, and / or - a mercury content less than or equal to 5 ppb by weight.

17. Product according to claims 15 and 16 comprising a biological carbon content according to ASTM D6866 of between 1 and 70% by weight.

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