PROCESS FOR TREATMENT OF PYROLYSIS OILS FROM PLASTICS AND / OR RECOVERED SOLID FUEL CONTAINING IMPURITIES

Abstract

The invention relates to a process for treating a pyrolysis oil from plastics and / or solid recovered fuels comprising: a) optionally a selective hydrogenation of the feed; b) a boiling bed, entrained bed and / or moving bed hydroconversion, to obtain a hydroconvert effluent; c) a separation of the effluent from step b) in the presence of an aqueous stream, to obtain a gaseous effluent, an aqueous effluent and a hydrocarbon liquid effluent; d) optionally a fractionation to obtain at least a gaseous stream and a cut having a boiling point less than or equal to 150°C and a cut having a boiling point greater than 150°C.

Description

Title of the invention: PROCESS FOR TREATING PYROLYSIS OILS FROM PLASTICS AND / OR RECOVERED SOLID FUELS LOADED WITH IMPURITIES Technical field

[0001] The present invention relates to a method for treating a pyrolysis oil from plastics and / or solid recovered fuels (SRF), loaded with impurities in order to obtain a hydrocarbon effluent which can be recovered by being at least partly directly integrated into a naphtha or diesel pool or as a feedstock for a steam cracking unit. More particularly, the present invention relates to a method for treating a feedstock resulting from the pyrolysis of plastic waste and / or SRF, in order to eliminate at least partly impurities that said feedstock may contain in significant quantities, and so as to hydrogenate the feedstock so that it can be recovered. Prior art

[0002] Plastics from collection and sorting channels can undergo a pyrolysis step in order to obtain, among other things, pyrolysis oils. These plastic pyrolysis oils are generally burned to generate electricity and / or used as fuel in industrial or district heating boilers.

[0003] Solid recovered fuels (SRF), also called "refuse derived fuel" or RDF in English terminology, 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. SRFs 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 (for example 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. SRFs can also consist of just one of the wastes mentioned above, for example used tires.SRFs generally contain plastic waste. SRFs are currently mainly used for energy. They can be used directly as substitutes for fossil fuels in co-incineration plants (coal and lignite thermal power plants, cement plants, lime kilns) or in household waste incineration units, or indirectly in pyrolysis units dedicated to energy recovery: SRF pyrolysis oils are thus generally burned to generate electricity, or even . used as fuel in industrial or district heating boilers.

[0004] Another way of recovering plastic pyrolysis oils or CSR is to be able to use these pyrolysis oils as a feedstock for a steam cracking unit in order to (re)create olefins, the latter being monomers constituting certain polymers. However, plastic waste or CSR are generally mixtures of several polymers, for example mixtures of polyethylene, polypropylene, polyethylene terephthalate, polyvinyl chloride, polystyrene. In addition, depending on the uses, plastics may contain, in addition to polymers, other compounds, such as plasticizers, pigments, dyes or even residues of polymerization catalysts, as well as other very varied impurities, organic and mineral, originating from the separation operations of sorting centers, an operation whose selectivity may not be total.Oils from the pyrolysis of plastics or CSR thus contain many impurities, in particular diolefins, metals, silicon, or halogenated compounds, including chlorine-based compounds, heteroelements such as sulfur, oxygen and nitrogen, and insolubles, often at high levels and incompatible 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, coking or catalytic deactivation problems, or even problems of incompatibility in the uses of the target polymers. The presence of diolefins very often leads to problems of instability of the pyrolysis oil characterized by the formation of gums.Gums and insolubles possibly present in pyrolysis oil can cause clogging problems in the processes.

[0005] Furthermore, during the steam cracking stage, the yields of light olefins sought for petrochemicals, in particular ethylene and propylene, depend very strongly on the quality of the feedstocks sent to steam cracking. The BMCI index (Bureau of Mines Correlation Index) is often used to characterize hydrocarbon cuts. This index, developed for hydrocarbon products derived from crude oils, is calculated from the measurement of the density and the average boiling point: it is equal to 0 for a linear paraffin and to 100 for benzene. Its value is therefore higher when the product analyzed has an aromatic condensed structure, naphthenes having a BMCI intermediate between paraffins and aromatics. Overall, the yields of light olefins increase when the paraffin content increases and therefore when the BMCI decreases.Conversely, the yields of unsought heavy compounds and / or . in coke increase when the BMCI increases.

[0006] Document WO 2018 / 055555 proposes a global, very general and relatively complex process for recycling plastic waste, ranging from the actual step of pyrolysis of the plastic waste to the steam cracking step. The process comprises, among other things, a step of hydrotreatment of the liquid phase resulting directly from the pyrolysis, preferably under fairly advanced conditions, particularly in terms of temperature, for example at a temperature of between 260 and 300°C, a step of separation of the hydrotreatment effluent and then a step of hydrodealkylation of the separated heavy effluent at a preferably high temperature, for example of between 260 and 400°C.

[0007] Due to the impurity content of pyrolysis oils, particularly when they are heavily loaded with impurities, deactivation of the catalysts in the hydrotreatment unit which is operated in a fixed bed can be observed, which reduces the cycle time. Indeed, the main constraint of fixed bed units is the fact of having to stop the unit to replace the catalysts. In addition, pyrolysis oils, particularly those heavily loaded with impurities, can create clogging problems, particularly in preheating furnaces, charge / effluent exchangers or on the bed heads of catalytic reactors.

[0008] It would therefore be advantageous to propose a process for treating pyrolysis oils having long-lasting catalytic cycles by allowing the replacement of the catalysts without stopping the unit, while producing an alkane-rich cut which can be easily recovered in a steam cracking unit.

[0009] Hydroconversion units operated in an ebullated bed, entrained bed or moving bed are capable of treating this type of feedstock thanks to a system for adding fresh catalyst and withdrawing used catalyst without stopping the unit. The addition of fresh catalyst and the withdrawal of used catalyst are generally carried out continuously, semi-continuously or periodically. These systems, which compensate for the deactivation of the catalysts due to impurities in the plastic or CSR pyrolysis oils and solve the problems of clogging of the catalyst beds of reactors operated in a fixed bed, allow the hydroconversion units to have a long cycle duration without having to stop to replace the catalysts.

[0010] Unpublished patent application FR 20 / 09.750 describes such a process for treating a plastic and / or CSR pyrolysis oil comprising in particular:

[0011] a) optionally a step of selective hydrogenation of said feedstock in the presence of hydrogen and a selective hydrogenation catalyst to obtain a hydrogenated effluent;

[0012] b) a hydroconversion step using at least one ebullated bed, entrained bed and / or moving bed reactor, comprising at least one catalyst hydroconversion, said hydroconversion reaction section being supplied at least by said feedstock or by said hydrogenated effluent from step a) and a gas stream comprising hydrogen, to obtain a hydroconverted effluent;

[0013] c) a separation step, fed with the hydroconverted effluent from step b) and an aqueous solution, said step being carried out at a temperature between 50 and 450°C, to obtain at least one gaseous effluent, one aqueous effluent and one hydrocarbon effluent;

[0014] d) a step of fractionating all or part of the hydrocarbon effluent from step c), to obtain at least one gas stream, a hydrocarbon cut comprising compounds having a boiling point less than or equal to 385°C and a hydrocarbon cut comprising compounds having a boiling point greater than 385°C,

[0015] e) a hydrotreatment step using at least one fixed bed reactor comprising at least one hydrotreatment catalyst, said hydrotreatment reaction section being

[0016] fed with at least a portion of said hydrocarbon fraction comprising compounds having a boiling point less than or equal to 385°C from step d) and a gas stream comprising hydrogen, to obtain a hydrotreated effluent;

[0017] f) a separation step, fed with the hydrotreated effluent from step e) to obtain at least one gaseous effluent and one hydrotreated liquid hydrocarbon effluent.

[0018] Unpublished patent application FR 21 / 04.873 which is based on the process of FR 20 / 09.750 describes another process for treating a plastics and / or CSR pyrolysis oil in which the hydroconversion step using at least one ebullated bed, entrained bed and / or moving bed reactor is followed by a hydrotreatment step using at least one fixed bed reactor without an intermediate separation step between the hydroconversion step and the hydrotreatment step.

[0019] The research work led the applicant to discover that, surprisingly, a simplification of existing processes is possible by eliminating the hydrotreatment step after the hydroconversion step. By applying more severe operating conditions and / or by choosing highly active catalysts in the hydroconversion step, it is possible to obtain a pyrolysis oil which can be directly recovered by incorporating it into a fuel pool and / or which is directly compatible with treatment in a steam cracking unit without the need to carry out a hydrotreatment step after the hydroconversion. Indeed, by choosing the operating conditions and / or suitable catalysts, the hydrotreatment reactions, in particular hydrodenitrogenation, are sufficiently carried out in the hydroconversion step. Summary of the invention

[0020] The invention relates to a method for treating a feedstock comprising a pyrolysis oil from recovered plastics and / or solid fuels, preferably comprising in the given order:

[0021] a) optionally, a selective hydrogenation step carried out in a reaction section supplied at least by said feedstock and a gas stream comprising hydrogen, in the presence of at least one selective hydrogenation catalyst, at a temperature between 100 and 280°C, a partial pressure of hydrogen between 1.0 and 20.0 MPa abs. and an hourly volumetric velocity between 0.3 and 10.0 h1, to obtain a hydrogenated effluent;

[0022] b) a hydroconversion step carried out in a hydroconversion reaction section, using at least one ebullated bed, entrained bed and / or moving bed reactor, comprising at least one hydroconversion catalyst, said hydroconversion reaction section being fed at least by said feedstock or by said hydrogenated effluent from step a) and a gas stream comprising hydrogen, said hydroconversion reaction section being carried out at a temperature between 300 and 450°C, a hydrogen partial pressure between 5.0 and 20.0 MPa abs and an hourly volumetric flow rate between 0.03 and 2.0 h1, to obtain a hydroconverted effluent;

[0023] c) a separation step, fed with the hydroconverted effluent from step b) and an aqueous solution, said step being carried out at a temperature between 20 and 450°C, to obtain at least one gaseous effluent, one aqueous effluent and one hydrocarbon effluent,

[0024] d) optionally a step of fractionating all or part of the hydrocarbon effluent from step c), to obtain at least one gaseous effluent and at least one hydrocarbon cut comprising compounds having a boiling point less than or equal to 150°C and a hydrocarbon cut comprising compounds having a boiling point greater than 150°C.

[0025] In the remainder of the text, the term “pyrolysis oil” means an oil resulting from the pyrolysis of plastics and / or CSR, unless otherwise indicated.

[0026] An advantage of the process according to the invention is to purify a pyrolysis oil from at least part 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 a fuel pool and / or by making it compatible with treatment in a steam cracking unit in order to be able to obtain, in particular, light olefins which can be used as monomers in the manufacture of polymers.

[0027] 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 pyrolysis oil.

[0028] The process of the invention thus makes it possible to obtain a hydrocarbon effluent from a pyrolysis oil freed at least in part from the impurities of the starting pyrolysis oil, thus limiting the operability problems, such as the problems of corrosion, coking or catalytic deactivation, which these impurities can cause, in particular in the steam cracking units and / or in the units located downstream of the steam cracking units, in particular the polymerization and selective hydrogenation units. The elimination of at least part of the impurities from the pyrolysis oils will also make it possible to increase the range of applications of the target polymers, the incompatibilities of use being reduced.

[0029] Carrying out a hydroconversion step using a system for adding fresh catalyst and withdrawing used catalyst without stopping the unit makes it possible in particular to treat pyrolysis oils that are heavily loaded with impurities.

[0030] Carrying out a hydroconversion step using a system for adding fresh catalyst and withdrawing used catalyst without stopping the unit also makes it possible to transform at least part of the heavy compounds into lighter compounds, which makes it possible to obtain improved yields in a cut suitable for the steam cracking unit and, when this cut is sent for steam cracking, into light olefins.

[0031] On the other hand, the process according to the invention is characterized by the fact that it does not require a hydrotreatment step after the hydroconversion step, which represents a saving in reactor, equipment and energy.

[0032] According to a variant, the hydrocarbon effluent from separation step c), or at least one of the two liquid hydrocarbon streams from step d), is sent in whole or in part to a steam cracking step e) 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.

[0033] According to a variant, when step b) is carried out in an ebullated bed or in a moving bed, said hydroconversion catalyst of step b) comprises a supported catalyst comprising a metal from group VIII chosen from the group formed by Ni, Pd, Pt, Co, Rh and / or Ru, optionally a metal from group VIB chosen from the group Mo and / or W, on an amorphous mineral support chosen from the group formed by alumina, silica, silica-aluminas, magnesia, clays and mixtures of at least two of these minerals, and when step b) is carried out in an entrained bed, said hydroconversion catalyst of step b) comprises a dispersed catalyst containing at least one element chosen from the group formed by Mo, Fe, Ni, W, Co, V, Ru.

[0034] According to a variant, the method comprises a step aO) of pretreatment of the load, said pretreatment step being implemented upstream of step a) hydrogenation and comprising a filtration step and / or an electrostatic separation step and / or a washing step using an aqueous solution and / or an adsorption step.

[0035] According to a variant, the fractionation step d) further comprises a fractionation making it possible to obtain, in addition to a gas stream, a naphtha cut comprising compounds having a boiling point less than or equal to 150°C, and a kerosene cut comprising compounds having a boiling point greater than 150°C and less than or equal to 280°C, a diesel cut comprising compounds having a boiling point greater than 280°C and less than 360°C and a hydrocarbon cut comprising compounds having a boiling point greater than or equal to 360°C, called a heavy hydrocarbon cut.

[0036] According to a variant, the fractionation step d) further comprises a fractionation of the hydrocarbon cut comprising compounds having a boiling point less than or equal to 150°C into a light naphtha cut comprising compounds having a boiling point less than 80°C and a heavy naphtha cut comprising compounds having a boiling point between 80 and 150°C.

[0037] According to a variant, the method further comprises a hydrotreatment step, said hydrotreatment step being carried out before or after the separation step c), or after the fractionation step d), said hydrotreatment step being 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 with at least a portion of said hydroconverted effluent from step b), or at least a portion of said hydrocarbon effluent from step c) or at least a portion of said hydrocarbon cut comprising compounds having a boiling point greater than 150°C from step d) and a gas stream comprising hydrogen,said hydrotreatment reaction section being carried out at a temperature between 250 and 430°C, a hydrogen partial pressure between 1.0 and 20.0 MPa abs. and an hourly volumetric flow rate between 0.1 and 10.0 h1, to obtain a hydrotreated effluent.

[0038] According to this variant, said hydrotreatment catalyst comprises a support chosen from the group consisting of 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.

[0039] According to a variant, the process further comprises a hydrocracking step, said hydrocracking step being carried out either after a hydrotreatment step or after fractionation step d), said hydrocracking step being carried out in a hydrocracking reaction section, using at least one fixed bed 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 hydrotreated effluent and / or with the hydrocarbon fraction comprising compounds having a boiling point greater than 150°C from step d) 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 h1, to obtain a hydrocracked effluent.

[0040] According to this variant, the method further comprises a second hydrocracking step implemented in a hydrocracking reaction section, implementing at least one fixed bed 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 a hydrocarbon fraction comprising compounds having a boiling point greater than 150°C from the first hydrocracking step and a gas stream comprising hydrogen, said hydrocracking reaction section being implemented at a temperature between 250 and 450°C, a hydrogen partial pressure between 1.5 and 20.0 MPa abs. and an hourly volumetric flow rate between 0.1 and 10.0 h1, to obtain a hydrocracked effluent.

[0041] According to a variant, said hydrocracking catalyst comprises a support chosen from halogenated aluminas, combinations of boron and aluminum oxides, amorphous silica-aluminas and zeolites and a hydro-dehydrogenating function comprising at least one metal from group VIB chosen from chromium, molybdenum and tungsten, alone or as a mixture, and / or at least one metal from group VIII chosen from iron, cobalt, nickel, ruthenium, rhodium, palladium and platinum.

[0042] According to one variant, the process comprises said step a) of selective hydrogenation.

[0043] According to one variant, said selective hydrogenation catalyst 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.

[0044] According to one variant, the filler has the following properties: - an aromatic content of between 0 and 90% by weight, - a halogen content of between 2 and 5000 ppm by weight, - a metallic element content of between 10 and 10000 ppm by weight, - including an iron element content of between 0 and 100 ppm by weight, - a silicon element content of between 0 and 1000 ppm by weight, - a content of heteroelements provided by sulfur compounds, oxygenated compounds and / or nitrogen compounds of between 0 and 20,000 ppm by weight.

[0045] The invention also relates to the product capable of being obtained by the treatment method according to the invention.

[0046] According to a variant, the product 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, - including an iron element content less than or equal to 200 ppb by weight, - a silicon element content less than or equal to 5.0 ppm by weight, - a sulfur content less than or equal to 500 ppm by weight, - a nitrogen content less than or equal to 50 ppm by weight, - a chlorine element content less than or equal to 10 ppm by weight.

[0047] 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.

[0048] 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.

[0049] In the sense of the present invention, the different parameter ranges for a given step such as pressure ranges and temperature ranges can be used alone or in combination. For example, in the sense of the present invention, a range of preferred pressure values ​​can be combined with a range of more preferred temperature values.

[0050] 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 this is technically feasible.

[0051] 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, 81st edition, 2000-2001). For example, group VIII according to the CAS classification corresponds to the metals of columns 8, 9 and 10 according to the new IUP AC classification.

[0052] The metal content is measured by X-ray fluorescence. LIST OF FIGURES

[0053] The mention of the elements referenced in [Fig.l] allows a better understanding of the invention, without it being limited to the particular embodiments illustrated in [Fig.l]. The different embodiments presented can be used alone or in combination with each other, without limitation of combination. DETAILED DESCRIPTION The charge

[0054] According to the invention, a “plastic pyrolysis oil or CSR pyrolysis oil” is an oil, advantageously in liquid form at room temperature, resulting from the pyrolysis of plastics, preferably from plastic waste originating in particular from collection and sorting channels, or resulting from the pyrolysis of CSR, for example from the pyrolysis of used tires. It comprises in particular a mixture of hydrocarbon compounds, in particular paraffins, olefins, naphthenes and aromatics. At least 80% by weight of these hydrocarbon compounds preferably have a boiling point below 700°C, and preferably below 550°C. In particular, depending on the origin of the pyrolysis oil, it may comprise up to 70% by weight of paraffins, up to 90% by weight of olefins and up to 90% by weight of aromatics, it being understood that the sum of paraffins, olefins and aromatics is 100% by weight of the hydrocarbon compounds.

[0055] The density of the pyrolysis oil, measured at 15°C according to the ASTM D4052 method, is generally between 0.75 and 0.99 g / cm3, preferably between 0.75 and 0.95 g / cm3.

[0056] The pyrolysis oil may comprise, and most often does comprise, in addition impurities such as metals, in particular iron, silicon, halogenated compounds, in particular chlorinated compounds. These impurities may be present in the pyrolysis oil at high levels, for example up to 500 ppm by weight or 1000 ppm by weight or even 5000 ppm by weight of halogenated elements provided by halogenated compounds, and up to 2500 ppm by weight or even 10000 ppm by weight of metallic or semi-metallic elements. Alkali metals, alkaline earth metals, transition metals, poor metals and metalloids may be assimilated to contaminants of a metallic nature, called metals or metallic or semi-metallic elements. The pyrolysis oil may comprise up to 200 ppm by weight or 1000 ppm by weight of silicon, and up to 15 ppm by weight or 100 ppm by weight of iron.The pyrolysis oil may also include other impurities such as hetero-elements provided in particular by sulfur compounds, oxygenated compounds and / or nitrogen compounds, at contents generally less than 20,000 ppm by weight of hetero-elements and preferably less than 10,000 ppm by weight of hetero-elements.

[0057] The process according to the invention is particularly well suited to treating a pyrolysis oil loaded with impurities. This means a charge having the following properties: - an aromatic content of between 0 and 90% by weight, often between 20 and 90% by weight, and which may be between 50 and 90% by weight; - a halogen content of between 2 and 5000 ppm by weight, often between 200 and 5000 ppm by weight, and possibly between 500 and 5000 ppm by weight; - a content of metallic elements between 10 and 10,000 ppm by weight, often between 2,000 and 10,000 ppm by weight, and which may be between 2,250 and 5,000 ppm by weight; - with an iron element content of between 0 and 100 ppm by weight, often between 10 and 100 ppm by weight, and which may be between 15 and 100 ppm by weight; - a silicon element content of between 0 and 1000 ppm by weight, often between 100 and 1000 ppm by weight, and which may be between 200 and 1000 ppm by weight - a heteroelement content provided in particular by sulphur compounds, oxygenated compounds and / or nitrogen compounds of between 0 and 20000 ppm by weight, and often between 1000 and 10000 ppm by weight.

[0058] The process according to the invention is particularly well suited to treating pyrolysis oil heavily laden with impurities. This means a charge having the following properties: - an aromatic content of between 30 and 70% by weight; - a halogen content of between 500 and 5000 ppm by weight; - a metallic element content of between 300 and 5000 ppm by weight; - with an iron element content of between 15 and 100 ppm by weight; - a silicon element content of between 200 and 1000 ppm by weight; - a content of heteroelements provided in particular by sulfur compounds, oxygenated compounds and / or nitrogen compounds of between 1000 and 10000 ppm by weight.

[0059] The feedstock of the process according to the invention comprises at least one plastics and / or CSR pyrolysis oil. Said feedstock may consist solely of plastics pyrolysis oil(s) or solely of CSR pyrolysis oil(s) or solely of a mixture of plastics and CSR pyrolysis oil(s). Preferably, said feedstock comprises at least 50% by weight, preferably between 50 and 100% by weight, and particularly preferably between 75 and 100% by weight of plastics and / or CSR pyrolysis oil.

[0060] The pyrolysis oil from plastics and / or CSR can come from a thermal or catalytic pyrolysis treatment or can be prepared by hydropyrolysis (pyrolysis in the presence of a catalyst and hydrogen).

[0061] The feedstock of the process according to the invention may further comprise a conventional petroleum feedstock and / or a feedstock resulting from the conversion of biomass which is then co-treated with the plastics pyrolysis oil and / or CSR.

[0062] The conventional petroleum feedstock may advantageously be a cut or a mixture of cuts of the naphtha, vacuum gas oil, atmospheric residue or residue type. under a vacuum.

[0063] 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 limiting. 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.

[0064] The feedstock from biomass conversion may also be selected from feedstocks from thermal or catalytic conversion processes of biomass and / or organic waste, such as oils that are produced from biomass, in particular 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).

[0065] The feedstock resulting from the conversion of biomass can also advantageously be chosen from feedstocks resulting from the paper industry. Pre-treatment (optional)

[0066] Said feedstock comprising a pyrolysis oil may advantageously be pretreated in an optional pretreatment step aO), prior to the optional selective hydrogenation step a) or to the hydroconversion step b) when step a) is not present, to obtain a pretreated feedstock which feeds step a) or step b).

[0067] This optional pretreatment step aO) makes it possible to reduce the quantity of contaminants, in particular the quantity of silicon and metals, possibly present in the feed comprising the pyrolysis oil. Thus, an optional step aO) of pretreatment of the feed comprising a pyrolysis oil can be carried out in particular when said feed comprises more than 50 ppm by weight, in particular more than 100 ppm by weight, more particularly more than 200 ppm by weight of metallic elements.

[0068] Said optional pretreatment step aO) may be implemented by any method known to those skilled in the art making it possible to reduce the quantity of contaminants. It may in particular comprise a filtration step and / or an electrostatic separation step and / or a washing step using an aqueous solution and / or an adsorption step.

[0069] Said optional pretreatment step aO) is advantageously carried out at a temperature between 0 and 150°C, preferably between 5 and 100°C, and at a pressure between 0.15 and 10.0 MPa abs, preferably between 0.2 and 1.0 MPa abs.

[0070] According to a variant, said optional pretreatment step aO) is carried out in an adsorption section operated in the presence of at least one adsorbent, preferably of the alumina type, having a specific surface area greater than or equal to 100 m2 / g, preferably greater than or equal to 200 m2 / g. The specific surface area of ​​said at least one adsorbent is advantageously less than or equal to 600 m2 / g, in particular less than or equal to 400 m2 / g. The specific surface area of ​​the adsorbent is a surface area measured by the BET method, i.e. the specific surface area determined by nitrogen adsorption in accordance with the ASTM D 3663-78 standard established from the BRUNAUER-EMMETT-TELLER method described in the periodical 'The Journal of the American Chemical Society', 6Q, 309 (1938).

[0071] 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 6 to 10 of the periodic table of elements (new IUP AC classification). The residence time of the load in the adsorbent section is generally between 1 and 180 minutes.

[0072] Said adsorption section of the optional step aO) comprises at least one adsorption column, preferably comprises at least two adsorption columns, preferably between two and four adsorption columns, containing said adsorbent. When the adsorption section comprises two adsorption columns, an operating mode may be a so-called "swing" operation, according to the established English term, in which one of the columns is online, i.e. in operation, while the other column is in reserve. When the absorbent of the online column is used up, this column is isolated while the column in reserve is put online, i.e. in operation. The used absorbent can then be regenerated in situ and / or replaced with fresh absorbent so that the column containing it can be put back online once the other column has been isolated.

[0073] Another mode of operation is to have at least two columns operating in series. When the absorbent in the column placed at the head is worn, this first column is isolated and the worn absorbent is either regenerated in situ or replaced by new ones. the fresh absorbent. The column is then put back online in the last position and so on. This operation is called permutable mode, or according to the English term "PRS" for Permutable Reactor System or even "lead and lag" according to the English term. The association of at least two adsorption columns makes it possible to overcome the possible and possibly rapid poisoning and / or clogging of the adsorbent under the joint action of metallic contaminants, diolefins, gums from diolefins and insolubles possibly present in the pyrolysis oil to be treated. The presence of at least two adsorption columns facilitates the replacement and / or regeneration of the adsorbent, advantageously without stopping the pretreatment unit, or even the process, thus making it possible to reduce the risks of clogging and therefore to avoid stopping the unit due to clogging, to control costs and to limit the consumption of adsorbent.

[0074] According to another variant, said optional pretreatment step aO) is implemented in a washing section with an aqueous solution, for example water or an acidic or basic solution. 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.

[0075] Said optional pretreatment step aO) may also optionally be supplied with at least a fraction of a recycle stream, advantageously from step c) or step d) of the process, in a mixture or separately from the feedstock comprising a pyrolysis oil.

[0076] Said optional pretreatment step aO) thus makes it possible to obtain a pretreated feedstock which then feeds the selective hydrogenation step a) when it is present, or the hydroconversion step b). Step a) of selective hydrogenation (optional)

[0077] According to the invention, the process may comprise a step a) of selective hydrogenation of the feedstock comprising a pyrolysis oil carried out in the presence of hydrogen, 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 the pyrolysis oil. 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. The styrenic compounds, in particular styrene, possibly present in the feedstock may also behave like the diolefins in terms of the formation of gums. fact that the double bond of the vinyl group is conjugated with the aromatic nucleus. Said selective hydrogenation step a) makes it possible to obtain a selectively hydrogenated effluent, i.e. an effluent with a reduced content of olefins, in particular diolefins and possibly styrene compounds.

[0078] According to the invention, said selective hydrogenation step a) is carried out in a reaction section supplied at least with said feedstock comprising a pyrolysis oil, or with the pretreated feedstock resulting from the optional pretreatment step aO), and a gas stream comprising hydrogen (H2).

[0079] Optionally, the reaction section of said step a) may also be further supplied with at least a fraction of a recycle stream, advantageously from step c) and / or step d).

[0080] Said reaction section implements a selective hydrogenation, preferably in a fixed bed, in the presence of at least one selective hydrogenation catalyst, advantageously at an average temperature (or WABT as defined below) between 100 and 280°C, preferably between 120 and 260°C, preferably between 130 and 250°C, a hydrogen partial pressure between 1.0 and 20.0 MPa abs, preferably between 5.0 and 15.0 MPa abs and at an hourly volumetric velocity (WH) between 0.3 and 10.0 h1, preferably between 0.5 and 5.0 h1.

[0081] According to the invention, the “average temperature” of a reaction section comprising at least one fixed-bed reactor corresponds to the Weight Average Bed Temperature (WABT) according to the established English term, well known to those skilled in the art. The average temperature is advantageously determined as a function of the catalytic systems, the equipment, and the configuration thereof, used. The average temperature (or WABT) is calculated as follows:

[0082] [Math.l]

[0083] with Tinput: the temperature of the effluent at the inlet of the reaction section and Toutput: the temperature of the effluent at the outlet of the reaction section.

[0084] The hourly volumetric flow rate (WH) is defined here as the ratio between the hourly volumetric flow rate of the feedstock comprising the pyrolysis oil, possibly pretreated, by the volume of catalyst(s).

[0085] The quantity of the gaseous flow comprising hydrogen (H2), feeding said reaction section of step a), is advantageously such that the hydrogen coverage is between 1 and 200 Nm3 of hydrogen per m3 of feed (Nm3 / m3), preferably between 1 and 50 Nm3 of hydrogen per m3 of feed (Nm3 / m3), more preferably between 5 and 20 Nm3 of hydrogen per m3 of feed (Nm3 / m3).

[0086] Hydrogen coverage is defined as the ratio of the volume flow rate of hydrogen taken under normal temperature and pressure conditions in relation to the volume flow rate of “fresh” load, i.e. the load to be treated, possibly pre-treated, without taking into account the possible recycled fraction, at 15°C (in normal m3, noted Nm3, of H2 per m3 of load).

[0087] The gaseous flow comprising hydrogen, which feeds the reaction section of step a), may consist of a hydrogen supplement and / or recycled hydrogen advantageously originating from step c) and / or from step d).

[0088] Step a) of selective hydrogenation is preferably carried out in a fixed bed. It can also be carried out in an ebullating bed or in a moving bed.

[0089] Advantageously, the reaction section of said step a) 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 according to the English term "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, to unload the spent catalyst, to reload the reactor with fresh catalyst and to put said reactor back into service without stopping the process. The PRS technology is described, in particular, in patent FR2681871.

[0090] According to a particularly preferred variant, the selective hydrogenation reaction section of step a) comprises two reactors operating in switchable mode.

[0091] 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.

[0092] Advantageously, said selective hydrogenation catalyst comprises a support, preferably mineral, and a hydro-dehydrogenating function.

[0093] 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 VIB, preferably chosen from molybdenum and tungsten. According to this variant, the total content expressed as oxides 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. 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 MoO3 and WO3 respectively.

[0094] The weight ratio expressed in metal oxide between the metal (or metals) of group VIB relative to the metal (or metals) of group VIII is preferably between 1 and 20, and preferably between 2 and 10.

[0095] According to this variant, the reaction section of said step a) comprises for example a hydrogenation catalyst comprising between 0.5% and 12% by weight of nickel, preferably between 1% 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 MoO3 relative to the weight of said catalyst) on a preferably mineral support, preferably on an alumina support.

[0096] According to another variant, the hydro-dehydrogenating function comprises, and is preferably constituted of, at least one element from group VIII, preferably nickel. According to this variant, the nickel content, expressed as NiO, 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.

[0097] 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 at least one selective 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 B2O5 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 y (gamma) or q (eta) alumina.

[0098] Said selective hydrogenation catalyst is for example in the form of extrudates.

[0099] Very preferably, in order to hydrogenate the diolefins as selectively as possible, step a) may use, in addition to the selective hydrogenation catalysts described above, also at least one selective hydrogenation catalyst used in step a) 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 MoO3 relative to the weight of said catalyst, on an alumina support. This catalyst, which is lightly loaded with metals, is preferably placed upstream of the selective hydrogenation catalysts described above.

[0100] The content of impurities, in particular diolefins, in the hydrogenated effluent obtained at the end of step a) is reduced compared to that of the same impurities, in particular diolefins, included in the process feedstock. Selective hydrogenation step a) generally allows at least 90% and preferably at least 99% of the diolefins contained in the initial feedstock to be converted. Step a) also allows the elimination, at least in part, of other contaminants, such as silicon. The hydrogenated effluent, obtained at the end of selective hydrogenation step a), is sent, preferably directly, to hydroconversion step b). Hydroconversion step b)

[0101] According to the invention, the treatment method comprises a hydroconversion step b) implemented in a hydroconversion reaction section, using at least one ebullated bed, entrained bed and / or moving bed reactor, comprising at least one hydroconversion catalyst, said hydroconversion reaction section being fed at least with said feedstock or with said hydrogenated effluent from step a), to obtain a hydroconverted effluent.

[0102] Advantageously, step b) implements hydroconversion reactions well known to those skilled in the art, and more particularly hydrotreatment reactions such as the hydrogenation of olefins, aromatics, halogenated compounds, hydrodemetallation, hydrodesulfurization, hydrodenitrogenation, etc. and hydrocracking reactions (HCK) which lead to the opening of the naphthenic ring or the fractionation of paraffins into several fragments of lower molecular weight, thermal cracking and polycondensation reactions (formation of coke) although the latter are not desired.

[0103] Advantageously, said hydroconversion reaction section is carried out at a pressure equivalent to that used in the reaction section of step a) of selective hydrogenation when it is present, but at a higher temperature than that of the reaction section of step a) of selective hydrogenation. Thus, said hydroconversion reaction section, regardless of whether an ebullated bed, entrained bed or / or moving bed reaction section is used, is advantageously carried out at a hydroconversion temperature between 300 and 450°C, preferably between 350 and 420°C, at a hydrogen partial pressure between 5.0 and 20.0 MPa abs., more preferably between 6.0 and 15.0 MPa abs., and at an hourly volumetric flow rate (WH) between 0.03 and 2.0 h1, preferably between 0.1 and 1.0 h1.

[0104] According to the invention, the “hydroconversion temperature” corresponds to an average temperature in the hydroconversion reaction section of step b). The hydroconversion temperature is advantageously determined as a function of the catalytic systems, the equipment, the configuration thereof, by a person skilled in the art. For example, the ebullated bed hydroconversion temperature is determined by taking the arithmetic mean of the temperature measurements in the catalytic bed. The hourly volumetric flow rate (WH) is defined here as the ratio between the hourly volume flow rate of the hydrogenated effluent from step a) per volume of catalysts). The hydrogen coverage in step b) is advantageously between 50 and 1000 Nm3 of hydrogen per m3 of fresh feedstock, and preferably between 60 and 500 Nm3 of hydrogen per m3 of fresh feedstock, more preferably between 100 and 300 Nm3 of hydrogen per m3 of fresh feedstock. The 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 "fresh" feedstock, i.e. the feedstock to be treated, possibly pretreated, without taking into account the possible recycled fraction, at 15°C (in normal m3, noted Nm3, of H2 per m3 of feedstock). The gas stream comprising hydrogen, which feeds the reaction section of step b), may consist of a hydrogen supplement and / or recycled hydrogen advantageously originating from step c) and / or step d).

[0105] An important characteristic of the process according to the invention is the fact that the hydroconversion step is carried out in a reaction section allowing the addition of fresh catalyst and withdrawal of used catalyst without stopping the unit. Such systems are hydroconversion units operated in an ebullated bed, an entrained bed and / or a moving bed. The addition of fresh catalyst and withdrawal of used catalyst can thus be carried out continuously, semi-continuously or periodically.

[0106] The operating conditions used in hydroconversion step b) generally make it possible to achieve a conversion per pass of at least 5% by weight, preferably between 5 and 40% by weight, into products having at least 80% by weight of compounds having boiling points less than or equal to 150°C.

[0107] Advantageously, the hydroconversion step allows the hydrogenation of at least 80%, and preferably of all of the remaining olefins, 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, halogenated compounds (in particular chlorinated compounds), oxygenated compounds. Preferably, the nitrogen content at the outlet of step b) is less than 10 ppm by weight. Step b) 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 b) 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.

[0108] By applying fairly severe operating conditions and / or by choosing very active catalysts in the hydroconversion step, it is possible to obtain at least one hydrocarbon cut which can be directly recovered by incorporating it into a fuel pool and / or which is directly compatible with treatment in a steam cracking unit without the need to carry out a hydrotreatment step after the hydroconversion. Indeed, by the choice of operating conditions and / or ca suitable alysers, hydrotreatment reactions, in particular hydrodenitrogenation, are sufficiently carried out in the hydroconversion stage. Step b) of hydroconversion in ebullated bed

[0109] Thus, according to a first variant, the hydroconversion step b) is implemented in a hydroconversion reaction section using at least one ebullated bed reactor.

[0110] The operation of the ebullated bed reactor, including the recycling of reactor liquids upwards through the stirred catalyst bed, is generally well known. A mixture of feedstock and hydrogen is passed upwards over a bed of catalyst particles at a flow rate such that the particles are subjected to forced random motion while the liquid and gas pass upwards through the bed. The movement of the catalyst bed is controlled by a flow of recycle liquid such that, in steady-state operation, the mass of the catalyst does not rise above a definable level in the reactor. The vapors and liquid being hydrogenated pass through the upper level of the bed of catalyst particles to reach a zone substantially free of catalyst and are then discharged from the upper part of the reactor. A fraction of the reactor liquids is continuously recycled into the reactor.Ebullated bed technologies use supported catalysts, usually in the form of extrudates or beads whose diameter is generally of the order of 1 mm or less. The catalysts remain inside the reactors and are not evacuated with the products. Catalytic activity can be maintained constant thanks to on-line catalyst replacement. It is therefore not necessary to shut down the unit to change the used catalyst, nor to increase reaction temperatures along the cycle to compensate for deactivation. In addition, working at constant operating conditions allows for consistent yields and product qualities throughout the cycle. Also, because the catalyst is kept agitated by significant liquid recycling, the pressure drop across the reactor remains low and constant, and reaction exotherms are quickly averaged over the catalyst bed.

[0111] The used catalyst is partly replaced by fresh catalyst by withdrawal from the bottom of the reactor and introduction, either at the top of the reactor or at the bottom of the reactor, of fresh or new catalyst at regular time intervals, that is to say for example by burst or almost continuously. For example, fresh catalyst can be introduced every day. The replacement rate of the used catalyst by fresh catalyst can be for example from about 0.01 kilograms to about 10 kilograms per cubic meter of feed. This withdrawal and replacement are carried out using devices allowing the continuous operation of this hydroconversion step. The unit usually includes an internal recirculation pump allowing the maintenance of the bubbling bed catalyst by continuous recycling of at least part of the liquid withdrawn from the top of the reactor and reinjected into the bottom of the reactor. It is also possible to send the spent catalyst withdrawn from the reactor to a regeneration zone in which the carbon and sulfur it contains are removed, then to return this regenerated catalyst to the hydroconversion stage. It is also possible to send the regenerated catalyst to a rejuvenation zone in which a treatment is carried out to improve the activity of the catalyst (presulfurization, additivation, etc.), then to return this rejuvenated catalyst to the hydroconversion stage.

[0112] Catalysts used in ebullated beds are widely commercialized. They are granular catalysts whose size never reaches that of catalysts used in entrained beds. The catalyst is most often in the form of extrudates or beads. Typically, they contain at least one hydro-dehydrogenating element deposited on an amorphous support. Generally, the supported catalyst comprises a metal from group VIII chosen from the group formed by Ni, Pd, Pt, Co, Rh and / or Ru, optionally a metal from group VIB chosen from the group Mo and / or W, on an amorphous mineral support chosen from the group formed by alumina, silica, silica-aluminas, magnesia, clays and mixtures of at least two of these minerals. CoMo / alumina and NiMo / alumina catalysts are the most common.

[0113] The total content of oxides of the metal elements of groups VIB 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. 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 hydroconversion reaction section of step b) of the process comprises a hydroconversion catalyst comprising between 0.5% and 10% by weight of nickel, preferably between 0.7% and 8% by weight of nickel, and particularly preferably between 0.8% and 5% by weight of nickel, expressed as nickel oxide NiO relative to the total weight of the hydroconversion catalyst, and between 1.0% and 30% by weight of molybdenum, preferably between 3.0% and 29% by weight of molybdenum, and particularly preferably between 5.0% and 25% by weight of molybdenum, expressed as molybdenum oxide MoO3 relative to the total weight of the hydroconversion catalyst, on a mineral support, preferably on an alumina support.

[0114] The support of said hydroconversion catalyst is advantageously chosen from alumina, silica, silica-aluminas, magnesia, clays and mixtures thereof. Said support may further 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 hydroconversion 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 B2O5 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 y (gamma) or q (eta) alumina.

[0115] Said hydroconversion catalyst is for example in the form of extrudates or beads.

[0116] Advantageously, said hydroconversion catalyst used in step b) of the process has a specific surface area greater than or equal to 250 m2 / g, preferably greater than or equal to 300 m2 / g. The specific surface area of ​​said hydroconversion catalyst is advantageously less than or equal to 800 m2 / g, preferably less than or equal to 600 m2 / g, in particular less than or equal to 400 m2 / g. The specific surface area of ​​the hydroconversion catalyst is measured by the BET method, i.e. the specific surface area determined by nitrogen adsorption in accordance with ASTM D 3663 established from the BRUNAUER-EMMETT-TELLER method described in the periodical 'The Journal of the American Chemical Society', 6Q, 309 (1938). Such a specific surface area makes it possible to further improve the removal of contaminants, in particular metals such as silicon.

[0117] Hydroconversion catalysts are distinguished from hydrotreatment catalysts in particular by a porosity adapted to the treatment of impurities, in particular metallic ones, and in particular by the presence of macroporosity.

[0118] According to another aspect of the invention, the hydroconversion 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. Step b) of hydroconversion in entrained bed

[0119] According to a second variant, the hydroconversion step b) is carried out in a hydroconversion reaction section using at least one entrained bed reactor, also called a slurry reactor according to Anglo-Saxon technology. The feedstock, hydrogen and catalyst are injected from below and circulate in an ascending current. The hydroconverted effluent and the unconsumed hydrogen as well as the catalyst are withdrawn from the top. Slurry hydroconversion technologies use a catalyst dispersed in the form of very small particles, whose size is a few tens of microns or less (generally 0.001 to 100 qm). The catalysts, or their precursors, are injected with the feedstock to be converted at the inlet of the reactors. The catalysts pass through the reactors with the feedstocks and products being converted, then they are carried along with the reaction products out of the reactors. They are found after separation in the heaviest fraction.

[0120] The slurry catalyst is a catalyst preferably containing at least one element chosen from the group formed by Mo, Fe, Ni, W, Co, V, Ru. These catalysts are generally monometallic or bimetallic (for example by combining a non-noble element from group VIII (Co, Ni, Fe) and an element from group VIB (Mo, W).

[0121] The catalysts used may be powders of heterogeneous solids (such as natural ores, iron sulfate, etc.), dispersed catalysts derived from water-soluble precursors ("water soluble dispersed catalyst" according to English terminology) such as phosphomolybdic acid, ammonium molybdate, or a mixture of Mo or Ni oxide with aqueous ammonia.

[0122] Preferably, the catalysts used are derived from precursors soluble in an organic phase ("oil soluble dispersed catalyst" according to English terminology). The precursors are organometallic compounds such as naphthenates of Mo, Co, Fe, or Ni or such as multi-carbonyl compounds of these metals, for example 2-ethylhexanoates of Mo or Ni, acetylacetonates of Mo or Ni, salts of C7-C12 fatty acids of Mo or W, etc. They can be used in the presence of a surfactant to improve the dispersion of the metals, when the catalyst is bimetallic.

[0123] The catalysts are in the form of dispersed particles, colloidal or not depending on the nature of the catalyst. Such precursors and catalysts usable in the process according to the invention are widely described in the literature.

[0124] The concentration of the catalyst, expressed in metallic element, is generally between 1 and 10,000 ppm relative to the charge.

[0125] In general, catalysts are prepared before being injected into the feedstock. The preparation process is adapted according to the state in which the precursor is found and its nature. In all cases, the precursor is sulfurized (ex-situ or in-situ) to form the catalyst dispersed in the feedstock.

[0126] For the preferred case of so-called oil-soluble catalysts, in a typical process, the precursor is mixed with a carbonaceous feedstock (which may be a part of the feedstock to be treated, an external feedstock, a recycled fraction, etc.), the mixture is optionally dried at least in part, then or simultaneously sulfurized by addition of a sulfur compound (preferably H2S) and heated. The preparations of these catalysts are described in the prior art.

[0127] Additives may be added during catalyst preparation or to the slurry catalyst before it is injected into the reactor. These additives are described in the literature.

[0128] Preferred solid additives are mineral oxides such as alumina, silica, mixed Al / Si oxides, used catalysts supported (for example, on alumina and / or silica) containing at least one element from group VIII (such as Ni, Co) and / or at least one element from group VIB (such as Mo, W). Examples include the catalysts described in application US2008 / 177124. Carbonaceous solids with a low hydrogen content (for example 4% hydrogen) such as coke, optionally pretreated, may also be used. Mixtures of such additives may also be used. Their particle sizes are preferably less than 1 mm. The content of any solid additive present at the inlet of the entrained bed hydroconversion reaction zone is between 0 and 10% by weight, preferably between 1 and 3% by weight, and the content of the catalytic solutions is between 0 and 10% by weight, preferably between 0 and 1% by weight relative to the weight of the injected feedstock.

[0129] When hydroconversion step b) is carried out in an entrained bed reactor, a filtration step to recover the catalyst is necessary before sending the hydroconverted effluent to step c). Step b) of hydroconversion in moving bed

[0130] According to a third variant, the hydroconversion step b) is carried out in a hydroconversion reaction section using at least one moving bed reactor.

[0131] The feedstock and hydrogen can circulate in ascending flow in moving bed reactors (countercurrent processes) or in descending flow (cocurrent processes). The catalyst flows progressively by gravity from top to bottom and in plug flow inside the catalytic zone. It is withdrawn from the bottom by any suitable means, for example a lift. An in-line device ensures the semi-continuous renewal of the catalyst in moving bed reactors: part of the spent catalyst is withdrawn from the bottom of the reactor while fresh catalyst is introduced at the top of the reactor. The temperature is controlled by inter- or intra-reactor quenching.

[0132] Preferably, spherical catalysts with a diameter of between 0.5 and 6 mm and preferably between 1 and 3 mm are used rather than extruded catalysts to obtain a better flow. When withdrawing the used catalyst from the bottom of the reactor, the entire catalytic bed moving in plug flow moves downwards by a height corresponding to the volume of catalyst withdrawn. The expansion rate of the catalytic bed operating in a moving bed is advantageously less than 15%, preferably less than 10%, preferably less than 5% and more preferably less than 2%. The expansion rate is measured according to a method known to those skilled in the art.

[0133] The hydroconversion catalyst used in the moving bed of step b) of the process according to the invention is advantageously a catalyst comprising a support, preferably amorphous and very preferably alumina and at least one metal from group VIII chosen from nickel and cobalt and preferably nickel, said group VIII element preferably being used in association with at least one metal from group VIB chosen from molybdenum and tungsten and preferably, the group VIB metal is molybdenum. Preferably, the hydroconversion catalyst comprises nickel as a group VIII element and molybdenum as a group VIB element.The nickel content is advantageously between 0.5 and 10% expressed by weight of nickel oxide (NiO) and preferably between 0.7 and 6% by weight, and the molybdenum content is advantageously between 1 and 30% expressed by weight of molybdenum trioxide (MoO3), and preferably between 4 and 20% by weight, the percentages being expressed as a percentage by weight relative to the total weight of the catalyst. This catalyst is advantageously in the form of extrudates or beads. This catalyst may also advantageously contain phosphorus and preferably a content of phosphoric anhydride P205 of less than 20% and preferably less than 10% by weight, the percentages being expressed as a percentage by weight relative to the total weight of the catalyst. The catalyst may also be a catalyst with the addition of an organic compound as described above.

[0134] According to yet another variant, the hydroconversion step b) can be carried out in a hydroconversion reaction section using a combination of at least one ebullated bed reactor, at least one entrained bed reactor and / or at least one moving bed reactor, and this in any order.

[0135] Preferably, step b) is carried out in a hydroconversion reaction section using at least one ebullated bed reactor. Separation step c)

[0136] According to the invention, the treatment method comprises a separation step c), advantageously implemented in at least one washing / separation section, fed at least with the hydroconverted effluent from step b), and an aqueous solution, to obtain at least one gaseous effluent, one aqueous effluent and one hydrocarbon effluent.

[0137] The gaseous effluent obtained at the end of step c) advantageously comprises hydrogen, preferably comprises at least 80% by volume, preferably at least 85% by volume, of hydrogen. Advantageously, said gaseous effluent can at least partly be recycled to steps a) of selective hydrogenation and / or b) of hydroconversion, the recycling system being able to comprise a purification section- fication.

[0138] The aqueous effluent obtained at the end of step c) advantageously comprises ammonium salts and / or hydrochloric acid.

[0139] This separation step c) 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 steps a) and b) then dissolution in water, and the ammonium ions, generated by the hydrogenation of the nitrogen compounds in the form of NH3, in particular during step b) 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. It also allows the elimination of hydrochloric acid formed by the reaction of hydrogen ions and chloride ions as well as part of the CO and CO2 if there is oxygen in the plastic and / or CSR pyrolysis oil.

[0140] Depending on the content of chlorinated compounds in the initial feedstock to be treated, a stream containing an amine such as, for example, monoethanolamine, diethanolamine and / or monodiethanolamine may be injected upstream of the selective hydrogenation step a) and / or the hydroconversion step b) and / or the separation step c), preferably upstream of the selective hydrogenation step a) when it is present in order to ensure a sufficient quantity of ammonium ions to combine the chloride ions formed during the hydroconversion step, thus making it possible to limit the formation of hydrochloric acid and thus to limit corrosion downstream of the separation section.

[0141] Advantageously, separation step c) comprises an injection of an aqueous solution, preferably an injection of water, into the hydroconverted effluent from step b), upstream of the washing / separation section, so as to dissolve at least in part ammonium chloride salts and / or hydrochloric acid and thus improve the elimination of chlorinated impurities and reduce the risks of blockages due to an accumulation of ammonium chloride salts.

[0142] Separation step c) is advantageously carried out at a temperature between 20 and 450°C, preferably between 50 and 450°C, preferably between 100 and 440°C, more preferably between 200 and 420°C. It is important to operate in this temperature range (and therefore not to cool the hydroconverted effluent too much) at the risk of blockage in the lines due to the precipitation of ammonium chloride salts. Advantageously, separation step c) is carried out at a pressure close to that used in steps a) and / or b), preferably between 1.0 and 20.0 MPa, so as to facilitate the recycling of hydrogen.

[0143] The washing / separation section of step c) can at least partly 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.).

[0144] In a possible embodiment of the invention, separation step c) comprises the injection of an aqueous solution into the hydroconverted effluent from step b), followed by the washing / separation section advantageously comprising a separation phase making it possible to obtain at least one aqueous effluent loaded with ammonium salts, a washed liquid hydrocarbon effluent and a partially washed gaseous effluent. The aqueous effluent loaded with ammonium salts and the washed liquid hydrocarbon effluent can then be separated in a settling tank in order to obtain said 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 hydrocarbon 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 step c) of separation into said aqueous solution upstream of the washing / separation section and / or into said aqueous stream in the washing column.Said water recycling circuit may include a water top-up and / or a basic solution and / or a purge to evacuate dissolved salts.

[0145] The gas fraction(s) resulting from separation step c) may be subject to additional purification(s) and separation(s) in order to recover at least one hydrogen-rich gas that can be recycled upstream of steps a) and / or b) and / or 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 e) so as to increase the overall yield of olefins.

[0146] The hydrocarbon effluent from separation step c) is sent, in part or in full, to fractionation step d). Part of the hydrocarbon effluent from step c) can also be sent directly to the inlet of a steam cracking unit or even be recycled in steps a) and / or b). Step d) of splitting (optional)

[0147] The process according to the invention may comprise a step of fractionating all or part, preferably all, of the hydrocarbon effluent from step c), to obtain at least one gaseous stream and at least two liquid hydrocarbon streams, said two liquid hydrocarbon streams being at least one hydrocarbon cut comprising compounds having a boiling point less than or equal to 150°C, in particular between 80 and 150°C, and a hydrocarbon cut comprising compounds having a boiling point greater than 150°C.

[0148] Step d) makes it possible in particular to eliminate gases dissolved in the liquid hydrocarbon effluent, such as for example ammonia, hydrogen sulfide and light hydrocarbons having 1 to 4 carbon atoms.

[0149] Fractionation step d) 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.

[0150] According to one embodiment, step d) can be carried out in a section advantageously comprising at least one stripping column equipped with a reflux circuit comprising a reflux drum. Said stripping column is fed with the liquid hydrocarbon effluent from step c) and with a stream of water vapor. The liquid hydrocarbon effluent from step c) can optionally be reheated before entering the stripping column. Thus, the lightest compounds are entrained at the top of the column and into 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 gaseous stream. The cut comprising compounds having a boiling point less than or equal to 150°C is advantageously withdrawn from the reflux drum.The hydrocarbon fraction comprising compounds having a boiling point above 150°C is advantageously withdrawn at the bottom of the stripping column.

[0151] According to other embodiments, the fractionation step d) can implement a stripping column followed by a distillation column or only a distillation column.

[0152] The cut comprising compounds having a boiling point less than or equal to 150°C and the cut comprising compounds having a boiling point greater than 150°C, 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.

[0153] According to a preferred embodiment, the hydrocarbon fraction comprising compounds having a boiling point less than or equal to 150°C, all or part, is sent to a steam cracking unit, while the hydrocarbon fraction comprising compounds having a boiling point above 150°C is recycled in step a) and / or b), and / or sent to a fuel storage unit.

[0154] In a particular embodiment, fractionation step d) can make it possible to obtain, in addition to a gas stream, a naphtha cut comprising compounds having a boiling point less than or equal to 150°C, preferably between 80 and 150°C, and a middle distillate cut comprising compounds having a boiling point greater than 150°C and less than 360°C, and a hydrocarbon cut comprising compounds having a boiling point greater than or equal to 360°C, called a heavy hydrocarbon cut.The naphtha cut can be sent, in whole or in part, to a steam cracking unit and / or to the naphtha pool from conventional petroleum feedstocks, it can still be recycled; the middle distillate cut can also be, in whole or in part, either sent to a steam cracking unit, or to a diesel pool from conventional petroleum feedstocks, or be recycled; the heavy cut can be sent, at least in part, to a steam cracking unit, or be recycled, in particular in hydroconversion step b).

[0155] In another particular embodiment, the fractionation step d) can make it possible to obtain, in addition to a gas stream, a naphtha cut comprising compounds having a boiling point less than or equal to 150°C, preferably between 80 and 150°C, and a kerosene cut comprising compounds having a boiling point greater than 150°C and less than or equal to 280°C, a diesel cut comprising compounds having a boiling point greater than 280°C and less than 360°C and a hydrocarbon cut comprising compounds having a boiling point greater than or equal to 360°C, called a heavy hydrocarbon cut.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 be recycled; the heavy cut may be sent, at least in part, to a steam cracking unit, or be recycled, in particular in hydroconversion step b).

[0156] In another particular embodiment, the hydrocarbon fraction comprising compounds having a boiling point less than or equal to 150°C from step d) is fractionated into a heavy naphtha fraction comprising compounds having a boiling point between 80 and 150°C and a light naphtha fraction comprising compounds having a boiling point less than 80°C, at least a portion of said heavy naphtha fraction being sent to an aromatic complex comprising at least one step of reforming the naphtha in order to produce aromatic compounds. According to this embodiment, at least a portion of the light naphtha fraction is sent to the steam cracking step e) described below.

[0157] The gas fraction(s) resulting from fractionation step d) may be the subject of additional purification(s) and separation(s) with a view to recovering at least light hydrocarbons, in particular ethane, propane and butane, which can advantageously be sent separately or as a mixture to one or more furnaces of steam cracking stage e) so as to increase the overall yield of olefins. Steam cracking stage e) (optional)

[0158] The hydrocarbon effluent from separation step c), or at least one of the two liquid hydrocarbon streams from step d), may be sent in whole or in part to a steam cracking step e).

[0159] Advantageously, the gas fraction(s) resulting from separation step c) and / or fractionation step d) and containing ethane, propane and butane, may also be sent in whole or in part to steam cracking step e).

[0160] Said steam cracking step e) 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 e) 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 at the inlet of step e). Preferably, the optional step e) is carried out in several pyrolysis furnaces in parallel so as to adapt the operating conditions to the different flows feeding step e), in particular from step d), and also to manage the decoking times of the tubes.A furnace comprises one or more tubes arranged in parallel. A furnace can also refer to a group of furnaces operating in parallel. For example, a furnace may be dedicated to cracking the cut comprising compounds having a boiling point less than or equal to 150°C.

[0161] 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 e) 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 recycling 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 fraction comprising pyrolysis oil.Columns are used to separate the different constituents of the light fractionation fraction in order to recover at least one cut rich in ethylene (C2 cut) and one cut rich in propylene (C3 cut) and possibly one 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.

[0162] This steam cracking step e) 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. Process variations

[0163] According to a preferred embodiment of the invention, the method for treating a load comprising a pyrolysis oil comprises, preferably consists of, the sequence of steps, and preferably in the given order: b) hydroconversion, c) separation.

[0164] According to another preferred embodiment of the invention, the method for treating a load comprising a pyrolysis oil comprises, preferably consists of, the sequence of steps, and preferably in the given order: b) hydroconversion, c) separation, d) fractionation.

[0165] According to another preferred embodiment of the invention, the method for treating a load comprising a pyrolysis oil comprises, preferably consists of, the sequence of steps, and preferably in the given order: a) selective hydrogenation, b) hydroconversion, c) separation, d) fractionation.

[0166] All embodiments may comprise and preferably consist of more than one pretreatment step aO).

[0167] All embodiments may comprise and preferably consist of more than one steam cracking step f).

[0168] Although the process according to the invention makes it possible to obtain a pyrolysis oil which can be directly recovered by incorporating it into a fuel pool and / or which is directly compatible with treatment in a steam cracking unit without the need to carry out other hydrogen-based treatments apart from hydroconversion, the process can further include a hydrotreatment step and possibly a hydrocracking step which can be carried out at different points in the process according to the invention.

[0169] • Step c) of hydrotreatment (optional)

[0170] According to the invention, the treatment process may comprise a hydrotreatment step which may be carried out before or after step c) of separation, or after step d) of fractionation, in particular of the hydrocarbon cut comprising compounds having a boiling point above 150°C.

[0171] Advantageously, the hydrotreatment step 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.

[0172] The hydrotreatment step is carried out 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.

[0173] When the hydrotreatment step is carried out before the separation step c), said hydrotreatment reaction section is fed with at least a portion of said hydroconverted effluent from step b) and a gas stream comprising hydrogen, to obtain a hydrotreated effluent.

[0174] When the hydrotreatment step is carried out after the separation step c), said hydrotreatment reaction section is fed with at least a portion of said hydrocarbon effluent from step c) and a gas stream comprising hydrogen, to obtain a hydrotreated effluent.

[0175] When the hydrotreatment step is carried out after the fractionation step d), said hydrotreatment reaction section is fed with at least a portion of said hydrocarbon cut comprising compounds having a boiling point above 150°C from step d) and a gas stream comprising hydrogen, to obtain a hydrotreated effluent.

[0176] Said hydrotreatment reaction section is advantageously carried out at an average hydrotreatment temperature between 250 and 430°C, preferably between 300 and 400°C, at a hydrogen partial pressure between 1.0 and 20.0 MPa abs., preferably between 3.0 and 15.0 MPa abs., and at an hourly volumetric flow rate (WH) between 0.1 and 10.0 h1, preferably between 0.1 and 5.0 h1, preferably between 0.2 and 2.0 h1, more preferably between 0.2 and 1.0 h1. The hydrogen coverage in the hydrotreatment step is advantageously between 50 and 2000 Nm3 of hydrogen per m3 of feed which feeds the hydrotreatment step, and preferably between 100 and 1000 Nm3 of hydrogen per m3 of feed, preferably between 120 and 800 Nm3 of hydrogen per m3 of feed.

[0177] The definitions of average temperature (WABT), WH and hydrogen coverage correspond to those described above in the hydrogenation step selective a).

[0178] The gas stream comprising hydrogen, which feeds the reaction section of the hydrotreatment stage, may consist of a hydrogen make-up and / or recycled hydrogen advantageously originating from stage c) and / or stage d).

[0179] Advantageously, said hydrotreatment step is carried out in a hydrotreatment 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, hydrotreatment catalyst(s). When a reactor comprises several catalytic beds, i.e. at least two, preferably between two and ten, preferably between two and five catalytic beds, said catalytic beds are preferably arranged in series in said reactor.

[0180] When the hydrotreatment step is implemented in a hydrotreatment reaction section comprising several, preferably two, reactors, these reactors can operate in series and / or in parallel and / or in permutable mode (or PRS) and / or in “swing” mode. The various possible operating modes, PRS mode (or lead and lag) and swing mode, are well known to those skilled in the art and are advantageously defined above.

[0181] In another embodiment of the invention, 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.

[0182] Advantageously, said hydrotreatment catalyst used in said hydrotreatment step may be chosen from known hydrodemetallization, hydrotreatment, 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.

[0183] 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 VIB, preferably selected from the group consisting of molybdenum and tungsten. The total content of oxides of the metal elements of groups VIB 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. 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 of step c) of the process 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 total weight of molybdenum and / or tungsten, preferably between 3.0% and 29% by weight, expressed as molybdenum oxide MoO3 or tungsten oxide WO3 relative to the total weight of the hydrotreatment catalyst, on a mineral support.

[0184] The support of said hydrotreatment catalyst is advantageously chosen from alumina, silica, silica-aluminas, magnesia, clays and mixtures thereof. Said support may also advantageously 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 B2O5 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 y (gamma) or q (eta) alumina.

[0185] Said hydrotreatment catalyst is for example in the form of extrudates.

[0186] Advantageously, said hydrotreatment catalyst used in the hydrotreatment step has a specific surface area greater than or equal to 250 m2 / g, preferably greater than or equal to 300 m2 / g. The specific surface area of ​​said hydrotreatment catalyst is advantageously less than or equal to 800 m2 / g, preferably less than or equal to 600 m2 / g, in particular less than or equal to 400 m2 / 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 established from the BRUNAUER-EMMETT-TELLER method described in the periodical 'The Journal of the American Chemical Society', 6Q, 309 (1938). Such a specific surface area makes it possible to further improve the removal of contaminants, particularly metals such as silicon.

[0187] 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. 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.

[0188] When the hydrotreatment step is carried out before the separation step c) and after the hydroconversion step b), and according to a first variant, said hydrotreatment step is carried out without an intermediate separation step between the hydroconversion step b) and the hydrotreatment step. The effluent from the hydroconversion step b) does not undergo any intermediate separation step of a gas stream between the hydroconversion step b) and the hydrotreatment step. This configuration can be described as an integrated scheme. By "without an intermediate separation step", is meant in the present invention the fact that at least a portion of the effluent from the hydroconversion step b) is introduced into the section allowing the implementation of the hydrotreatment step without changing chemical composition and without significant pressure loss."Separation" means one or more separating drums and / or one or more stripping or distillation columns, which may operate at different temperatures or pressures. "Significant pressure loss" means a pressure loss caused by an expansion valve or turbine, which could be estimated at a pressure loss of more than 10% of the total pressure. Those skilled in the art generally use these pressure losses or expansions during the separation stages.

[0189] In one embodiment, all of the effluent from the hydroconversion step b) is introduced into the section allowing the implementation of the hydrotreatment step.

[0190] In another embodiment, only a portion of the effluent from the hydroconversion step b) is introduced into the section allowing the implementation of the hydrotreatment step. This embodiment is however not contradictory with the fact that the process is without an intermediate separation step. This embodiment may consist of dividing the effluent from the hydroconversion step b) into two streams having the same composition, one going to the hydrotreatment step located downstream of it. This embodiment may therefore be similar to a partial short-circuit of the hydrotreatment section but, for the portion of the effluent from the hydroconversion section b) going to the hydrotreatment section, there is neither separation nor change in chemical composition, nor significant pressure loss. Another variant of this short-circuit embodiment may consist of dividing the effluent from hydroconversion step b) into several streams having the same composition, and sending one or more of these streams to the inlet of a first hydrotreatment reactor and one or more other of these streams to one or more downstream hydrotreatment reactors.

[0191] When the hydrotreatment step is carried out before the separation step c) and after the hydroconversion step b), and according to a second variant, said hydrotreatment step is carried out with an intermediate separation step between the hydroconversion step b) and the hydrotreatment step. Advantageously, said intermediate separation step comprises a step of fractionating all or part of the hydrocarbon effluent from step c), to obtain at least one gas stream, a hydrocarbon cut comprising compounds having a boiling point less than or equal to 360°C and a hydrocarbon cut comprising compounds having a boiling point greater than 360°C.Said hydrocarbon fraction comprising compounds having a boiling point less than or equal to 360°C is then introduced into the hydrotreatment stage, while the fraction comprising compounds having a boiling point greater than 360°C is preferably recycled into the hydroconversion stage b). When the hydrotreatment step is carried out before the separation step c) and after the hydroconversion step b) and in order to avoid carrying catalyst fines and / or catalysts from the hydroconversion step b) into said hydrotreatment reaction section, recovery means may be placed upstream or at the inlet of said hydrotreatment reaction section, for example one or more filters or even reactor internals, for example of the filter tray type, may be used. An example of a filter tray is described in patent FR3051375.

[0192] • Hydrocracking step (optional)

[0193] According to the invention, the treatment process may comprise a hydrocracking step carried out either after a hydrotreatment step or after step d) of fractionation, in particular of the hydrocarbon cut comprising compounds having a boiling point above 150°C.

[0194] Advantageously, the hydrocracking step uses 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 150°C into compounds having a boiling point less than or equal to 150°C contained in the hydrotreated effluent or separated during fractionation step d). Other reactions, such as the hydrogenation of olefins, aromatics, hydrodemetallization, hydrodesulfurization, hydrodenitrogenation, etc. can continue.

[0195] Compounds with a boiling point above 150°C have a high BMCI and 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 it is desired to minimize the yield of these heavy compounds (diesel cut) and maximize the yield of light compounds (naphtha cut), these compounds can be transformed at least in part into light compounds by hydrocracking, a cut generally favored for a steam cracking unit.

[0196] The hydrocracking step is 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.

[0197] When the hydrocracking step is carried out after a hydrotreatment step, said hydrocracking reaction section is fed with at least a portion of said hydrotreated effluent and a gas stream comprising hydrogen, to obtain a hydrocracked effluent, said hydrotreatment step being able to be carried out before or after step c) of separation, or after step d) of fractionation as described above.

[0198] When the hydrocracking step is carried out after the fractionation step d), said hydrocracking reaction section is fed with at least a portion of said hydrocarbon cut comprising compounds having a boiling point above 150°C from step d) and a gas stream comprising hydrogen, to obtain a hydrocracked effluent.

[0199] Said hydrocracking reaction section is advantageously carried out at an average temperature between 250 and 450°C, preferably between 320 and 440°C, at a hydrogen partial pressure between 1.5 and 20.0 MPa abs., preferably between 2 and 18.0 MPa abs., and at an hourly volumetric flow rate (WH) between 0.1 and 10.0 h1, preferably between 0.1 and 5.0 h1, preferentially between 0.2 and 4 h1. The hydrogen coverage in the hydrocracking step is advantageously between 80 and 2000 Nm3 of hydrogen per m3 of fresh feedstock which feeds step a) or b), and preferably between 200 and 1800 Nm3 of hydrogen per m3 of fresh feedstock which feeds step a) or b). The definitions of average temperature (WABT), WH and hydrogen coverage correspond to those described above in the selective hydrogenation step a).

[0200] Advantageously, said hydrocracking reaction section is implemented at a pressure equivalent to that used in the reaction section of step hydrotreatment.

[0201] Advantageously, said hydrocracking step 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). When a reactor comprises several catalytic beds, i.e. at least two, preferably between two and ten, preferably between two and five catalytic beds, said catalytic beds are preferably arranged in series in said reactor.

[0202] The hydrotreatment step and the hydrocracking step can advantageously be carried out in the same reactor or in different reactors. In the case where they are carried out in the same reactor, the reactor comprises several catalytic beds, the first catalytic beds comprising the hydrotreatment catalyst(s) and the following catalytic beds comprising the hydrocracking catalyst(s).

[0203] The hydrocracking step can be carried out in one or two stages.

[0204] When carried out in two stages, a fractionation of the effluent from the first hydrocracking stage is carried out to obtain a hydrocarbon cut comprising compounds having a boiling point above 150°C, which is introduced into the second hydrocracking stage comprising a second dedicated hydrocracking reaction section, different from the first hydrocracking reaction section. This configuration is particularly suitable when it is desired to produce only a naphtha cut.

[0205] The second hydrocracking step is carried out in a hydrocracking reaction section, using at least one fixed bed 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 is fed with the hydrocarbon fraction comprising compounds having a boiling point greater than 150°C from the first hydrocracking step and a gas stream comprising hydrogen, said hydrocracking reaction section being carried out 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 h1, to obtain a hydrocracked effluent which can be sent to the separation step c). 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.

[0206] 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).

[0207] These operating conditions used in the hydrocracking step(s) generally make it possible to achieve a conversion per pass of greater than 15% by weight, and even more preferably between 20 and 95% by weight, into products having at least 80% by weight of compounds having boiling points less than or equal to 150°C. When the process is carried out in two hydrocracking steps, the conversion per pass in the second step is kept moderate in order to maximize the selectivity for compounds of the naphtha cut (having a boiling point less than or equal to 150°C, in particular between 80 and less than or equal to 150°C). The conversion per pass is limited by the use of a high recycle rate on the loop of the second hydrocracking step.This rate is defined as the ratio between the feed flow rate of the second hydrocracking stage and the flow rate of the feed of stage a), preferably this ratio is between 0.2 and 4, more preferably between 0.5 and 2.5.

[0208] The hydrocracking step(s) thus do not necessarily make it possible to transform all the compounds having a boiling point above 150°C into compounds having a boiling point less than or equal to 150°C. After the fractionation step d), there may therefore remain a more or less significant proportion of compounds having a boiling point above 150°C. To increase the conversion, at least a portion of this unconverted cut may be recycled as described below to the first hydrocracking step or even sent to a second hydrocracking step. 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 150°C relative to the incoming feed, and preferably between 0.5% and 5% by weight.

[0209] According to the invention, the hydrocracking step(s) operate(s) in the presence of at least one hydrocracking catalyst.

[0210] 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 (generally 150 to 800 m2 / g) 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 at least one metal from group VIB of the periodic table and / or at least one metal from group VIII.

[0211] 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 VIB 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.

[0212] 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.

[0213] Preferably, the content of group VIB 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 MoO3 and WO3 respectively.

[0214] The hydrocracking catalyst(s) may also optionally comprise at least one promoter element deposited on the catalyst and chosen from the group formed by phosphorus, boron and silicon, optionally at least one element from group VIIA (chlorine, fluorine preferred), optionally at least one element from group VIIB (manganese preferred), and optionally at least one element from group VB (niobium preferred).

[0215] 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.

[0216] Preferably, the silica-alumina contains more than 50% by weight of alumina, preferably more than 60% by weight of alumina.

[0217] Preferably, the hydrocracking catalyst(s) also optionally comprise a zeolite chosen from Y zeolites, preferably from US Y 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.

[0218] 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.

[0219] 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.

[0220] An even more preferred catalyst comprises, and preferably consists of, nickel, molybdenum, phosphorus, a USY zeolite, and optionally also a beta zeolite, and alumina.

[0221] Another preferred catalyst comprises, and preferably consists of, nickel, tungsten, alumina and silica-alumina.

[0222] Another preferred catalyst comprises, and preferably consists of, nickel, tungsten, USY zeolite, alumina and silica-alumina.

[0223] Said hydrocracking catalyst is for example in the form of extrudates.

[0224] In a 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.

[0225] According to another aspect of the invention, the hydrocracking 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, alcohol, thiol, thioether, sulfone, sulfoxide, ether, aldehyde, ketone, ester, carbonate, amine, nitrile, imide, oxime, urea and amide function or compounds including a furan cycle or sugars.

[0226] The preparation of selective hydrogenation (step a), hydroconversion (step b), hydrotreatment and hydrocracking catalysts is known and generally comprises a step of impregnation of the metals of group VIII and group VIB when present, and optionally phosphorus and / or boron on the support, followed by drying, then optionally 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. Here, calcination is understood to mean 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 process step, the catalysts are generally subjected to sulfurization in order to form the active species. The catalyst in step a) may also be a catalyst used in its reduced form, thus involving a reduction step in its preparation.

[0227] 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 selective hydrogenation step a) and / or the hydroconversion step b) and / or the hydrotreatment step and / or the hydrocracking step when they are present, preferably upstream of the selective hydrogenation step a) when it is present and / or the hydroconversion step b) in order to ensure a sufficient quantity of sulfur to form or maintain the active species of the catalyst (in sulfur form). 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 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-onyl-polysulfide type. The catalyst may 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 additive charge of dimethyl disulfide.

[0228] The gas stream comprising hydrogen, which feeds the reaction section of the selective hydrogenation step (step a), hydroconversion (step b), and the hydrotreatment and / or hydrocracking steps when they are present, may consist of a hydrogen make-up and / or recycled hydrogen advantageously from step c) and / or step d). 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. [Fig 1]

[0229] [Fig. 1] represents this diagram of a particular embodiment of the method of the present invention, comprising:

[0230] - a step a) of optional selective hydrogenation of a feedstock comprising a pyrolysis oil from plastics and / or CSR 1, in the presence of a hydrogen-rich gas 2, and optionally an amine supplied by stream 3 and optionally a sulfurizing agent supplied by stream 4, carried out in at least one fixed-bed reactor comprising at least one selective hydrogenation catalyst, to obtain an effluent 5;

[0231] - a step b) of hydroconversion of the effluent 5 from step a), in the presence of hydrogen 6 carried out in at least one ebullated bed, entrained bed and / or moving bed reactor comprising at least one hydroconversion catalyst, to obtain a hydroconverted effluent 7;

[0232] - a step c) of separation of the effluent 7 carried out in the presence of a solution aqueous washing fraction 8 and making it possible to obtain at least one gaseous fraction 9 comprising hydrogen, an aqueous fraction 10 containing dissolved salts, and a liquid hydrocarbon fraction 11;

[0233] - a step d) of fractionation of the liquid hydrocarbon fraction 11 allowing to obtain at least one gaseous fraction 12, a hydrocarbon fraction 13 comprising compounds having a boiling point less than or equal to 150°C and a hydrocarbon fraction 14 comprising compounds having a boiling point greater than 150°C.

[0234] At the end of step d), at least a portion of the liquid hydrocarbon effluents 13 and / or 14 is sent to a steam cracking process (not shown).

[0235] Optionally, a portion of said hydrocarbon fraction 13 comprising compounds having a boiling point less than or equal to 150°C constitutes a recycle stream which feeds steps a) and / or b) respectively (not shown).

[0236] Optionally, a portion of said hydrocarbon fraction 14 comprising compounds having a boiling point above 150°C constitutes a recycle stream which feeds step b) (not shown).

[0237] Instead of injecting the amine stream 3 and / or the sulfurizing agent 4 at the inlet of the selective hydrogenation step a), it is possible to inject it at the inlet of each of the reaction steps, in particular at the inlet of the hydroconversion step b) and possibly at the inlet of the hydrotreatment and / or hydrocracking steps when they are present. It is also possible not to inject the amine stream 3 and / or the sulfurizing agent 4, depending on the characteristics of the feedstock.

[0238] Only the main steps, with the main flows, are shown in [Fig.l], in order to allow a better understanding of the invention. It is understood that all the equipment necessary for operation is present (balloons, pumps, exchangers, furnaces, columns, etc.), even if not shown. It is also understood that hydrogen-rich gas streams (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.

[0239] Recycling of the hydrocarbon fraction comprising compounds having a boiling point above 150°C.

[0240] At least a fraction of the hydrocarbon cut comprising compounds having a boiling point above 150°C from fractionation step d) can be recovered to constitute a recycle stream which is sent upstream of or directly to at least one of the reaction steps of the process according to the invention, in particular to selective hydrogenation step a) and / or hydroconversion step b), and / or a hydrotreatment step and / or at least one hydrocracking step when they are present. Optionally, a fraction of the recycle stream can be sent to the optional step aO).

[0241] The recycle stream can feed said reaction stages in a single injection or can be divided into several fractions to feed the reaction stages in several injections, i.e. at different catalytic beds when the reactors are fixed bed reactors.

[0242] Advantageously, the quantity of the recycle stream of the cut comprising compounds having a boiling point above 150°C is adjusted so that the weight ratio between the recycle stream and the feed comprising a pyrolysis oil, i.e. the feed to be treated feeding the overall process, is less than or equal to 10, preferably less than or equal to 5, 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. Very preferably, the quantity of the recycle stream is adjusted so that the weight ratio between the recycle stream and the feed comprising a pyrolysis oil is between 0.2 and 5.

[0243] According to a preferred variant, at least a fraction of the cut comprising compounds having a boiling point above 150°C from fractionation step d) is sent to hydroconversion step b).

[0244] According to another preferred variant, at least a fraction of the cut comprising compounds having a boiling point above 150°C from fractionation step d) is sent to a hydrocracking step when it is present.

[0245] According to another preferred variant, at least a fraction of the cut comprising compounds having a boiling point above 150°C from fractionation step d) is sent to a second hydrocracking step when it is present.

[0246] The recycling of a portion of the cut comprising compounds having a boiling point above 150°C to or upstream of at least one of the reaction stages of the process according to the invention, and in particular to the hydroconversion stage b) and / or to the hydrocracking stages when they are present, advantageously makes it possible to increase the yield of naphtha cut having a boiling point below 150°C. The recycling also makes it possible to dilute the impurities and, on the other hand, to control the temperature in the reaction stage(s), in which the reactions involved may be highly exothermic.

[0247] A purge may be installed on the recycle of said cut comprising compounds having a boiling point above 150°C. 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 150°C relative to the incoming feed, and preferably between 0.5% and 5% by weight.

[0248] Recycling of the hydrocarbon effluent from step c) and / or of the hydrocarbon fraction having a boiling point less than or equal to 150°C from step d)

[0249] A fraction of the hydrocarbon effluent from separation step c) or a fraction of the cut having a boiling point less than or equal to 150°C from fractionation step d) can be recovered to constitute a recycle stream which is sent upstream of or directly to at least one of the reaction steps of the process according to the invention, in particular to selective hydrogenation step a) and / or a hydrotreatment step when it is present. Optionally, a fraction of the recycle stream can be sent to the optional pretreatment step a0).

[0250] Advantageously, the quantity of the recycle stream, i.e. the fraction of product obtained recycled, is adjusted so that the weight ratio between the recycle stream and the feed comprising a pyrolysis oil, i.e. the feed to be treated feeding the overall process, is less than or equal to 10, preferably less than or equal to 5, 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. Very preferably, the quantity of the recycle stream is adjusted so that the weight ratio between the recycle stream and the feed comprising a pyrolysis oil is between 0.2 and 5.

[0251] Advantageously, for the start-up phases of the process, a hydrocarbon cut external to the process can be used as a recycle stream. A person skilled in the art will then know how to choose said hydrocarbon cut.

[0252] The recycling of a portion of the product obtained to or upstream of at least one of the reaction stages of the process according to the invention 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 may be highly exothermic.

[0253] Said hydrocarbon effluent or said hydrocarbon stream(s) thus obtained by treatment according to the process of the invention of a plastics and / or CSR pyrolysis oil, has(have) a composition compatible with the specifications of an inlet feedstock of a steam cracking unit. In particular, the composition of the hydrocarbon effluent or said hydrocarbon stream(s) is preferably such that: - 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, preferably less than or equal to 1.0 ppm by weight and preferably less than or equal to 0.5 ppm by weight, with: a silicon (Si) element content of less than or equal to 5.0 ppm by weight, preferably less than or equal to 0.6 ppm by weight, and an iron (Fe) element content of less than or equal to 200 ppb by weight, - the sulfur content is less than or equal to 500 ppm by weight, preferably less than or equal to 200 ppm by weight, - the nitrogen content is less than or equal to 50 ppm by weight, preferably less than or equal to 50 ppm by weight and more preferably less than or equal to 5 ppm by weight - the asphaltene content is less than or equal to 5.0 ppm by weight, - the total chlorine element content is less than or equal to 10 ppm by weight, preferably less than 1.0 ppm by weight, - 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. 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.

[0254] The process according to the invention therefore makes it possible to treat plastic and / or CSR pyrolysis oils to obtain an effluent which can be injected, in whole or in part, into a steam cracking unit. Analysis methods used

[0255] 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 in particular listed below for information purposes. Other methods deemed equivalent may also be used, in particular equivalent IP, EN or ISO methods: Description Methods Density @15°C ASTM D4052 Sulfur Content ISO 20846 Nitrogen Content ASTM D4629 Acid Number ASTM D664 Bromine Number ASTM DI 159 Di-olefins Content from Maleic Anhydride Number MAV Method (1) Oxygenates Content Combustion + Infrared Paraffins Content UOP990-11 Naphthenes and Olefins Content UOP990-11 Aromatics Content UOP990-11 Halogens Content ASTM D7359 Chloride Content ASTM D7536 Metals Content: ASTM D5185 P Fe Si Na B Simulated Distillation ASTM D2887

[0257] (1) MAV method described in the article: C. Lôpez-Garcla et al., Near Infrared Mo- nitoring 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 EXAMPLE (in accordance with the invention)

[0258] Feedstock 1 treated in the process is a plastic pyrolysis oil having the characteristics indicated in Table 2.

[0259] Table 2: load characteristics Description Methods Unit Pyrolysis Oil Density @15°C ASTM D4052 g / cm3 0.80 Sulfur Content ISO 20846 ppm wt 300 Nitrogen Content ASTM D4629 ppm wt 600 Acid Number ASTM D664 mg KOH / g 0.1 Bromine Number ASTM DI 159 g / 100g 100 Di-olefins Content from Maleic Anhydride Number MAV Method % wt 3.0 Oxygenates Content Combustion + Infrared ppm wt 11000 Paraffins Content UOP990-11 % wt 30 Naphthenes and Olefins Content UOP990-11 % wt 65 Aromatics Content UOP990-11 % wt 5 Halogens Content ASTM D7359 ppm wt 150 Chloride Content ASTM D7536 ppm weight 100 Metal Content: ASTM D5185 P ppm weight 15 Fe ppm weight 10 Si ppm weight 60 Na ppm weight 1 B ppm weight 1 Simulated distillation ASTM D2887 0% °C 40 10% °C 90 30% °c 145 50% °c 200 70% °c 250 90% °c 310 100% °c 400

[0261] Charge 1 is subjected to a hydroconversion step b) carried out in an ebullated bed and in the presence of hydrogen 6, and a NiMo type catalyst (1% wt. NiO and 6% wt. MoO3) on alumina under the conditions presented in table 3.

[0262] Table 3: conditions of hydroconversion step b)

[0263] [Tables3] Hydroconversion temperature °C 380 Partial Pressure of Hydrogen MPa abs 11.0 H2 / HC (Volume coverage of hydrogen relative to the volume of feed) NmVm3 300 WH (volume flow rate of feed step b) / volume of catalysts) h1 1.5

[0264] Effluent 7 from hydroconversion step b) is sent to separation step c). A water stream is injected upstream of separation step c). The characteristics of effluent 11 (PI+) obtained after separation step c) are presented in table 5.

[0265] Effluent 11 (PI+) is then sent to fractionation step d). Table 4 gives the yields of the different fractions obtained at the outlet of fractionation step d), compared to feed 1 at the inlet of the process chain.

[0266] Table 4: yields of the different products and fractions obtained at the output of fractionation step d) h2s+ nh3 % weight 0.1 C1-C4 % weight 1.5 Fraction PL150°C % weight 35.5 Fraction 150°C+ % weight 63.8 Total % weight 100.9

[0268] The compounds H2S and NH3 are mainly eliminated in the form of salts in the aqueous phase eliminated in separation step c).

[0269] The characteristics of the liquid fractions PL150°C and 150°C+ obtained after fractionation step d) are presented in table 5:

[0270] Table 5: characteristics of the PI-150°C and 150°C+ fractions after fractionation step d) and of the PI+ fraction after separation step c) Fraction PI-150°C Fraction 150 °C+ PI+ Density @ 15°C (ASTM D4052) g / cm3 0.750 0.820 0.793 Content of: Sulfur (ASTM D5453) ppm wt <3 <5 <5 Nitrogen (ASTM D4629) PPm wt <5 < 10 < 10 Fe (ASTM D5185) PPb wt Not detected <50 <50 Total Metals (ASTM D5185) PPm wt Not detected <1 Not detected Chlorine (ASTM D7536) PPb wt Not detected <25 <25 Paraffins (UOP990-11) % wt 55 50 52 Naphthenes (UOP990-11) % wt 45 46 46 Olefins (UOP990-11) % wt Not detected Not detected Not detected Aromatics (UOP990-11) % weight <1 4 3 Simulated Distillation (ASTM D2887) in % 0 °C 25 140 25 5 °C 32 162 46 10 °c 40 174 74 30 °c 82 226 132 50 °c 108 281 195 70 °c 126 346 284 90 °c 142 365 358 95 °c 146 385 372 100 °c 160 390 390

[0272] Effluent 11 (PI+) and liquid fractions 13 and 14 (PI-150°C and 150°C+) all three have compositions compatible with a steam cracking unit since: - they do not contain olefins (mono- and di-olefins); - they have very low chlorine element contents and are below the limit required for a steam cracker load; - the metal contents, in particular iron (Fe), are also very low and below the limits required for a steam cracker feed (< 5.0 ppm by weight, very preferably < 1 ppm by weight for metals; < 100 ppb by weight for Fe); - finally they contain sulphur at levels well below the limits required for a steam cracker charge (< 500 ppm by weight, preferably < 200 ppm by weight for S and N).

[0273] The liquid fractions PL150°C and 150°C+ obtained are advantageously then sent to a steam cracking process.

Claims

Claims

1. A method of treating a feedstock comprising a pyrolysis oil from recovered plastics and / or solid fuels, comprising: a) optionally, a selective hydrogenation step carried out in a reaction section supplied at least by said feedstock and a gas stream comprising hydrogen, in the presence of at least one selective hydrogenation catalyst, at a temperature between 100 and 280°C, a partial pressure of hydrogen between 1.0 and 20.0 MPa abs. and an hourly volumetric flow rate between 0.3 and 10.0 h1, to obtain a hydrogenated effluent; b) a hydroconversion step carried out in a hydroconversion reaction section, using at least one ebullated bed, entrained bed and / or moving bed reactor, comprising at least one hydroconversion catalyst, said hydroconversion reaction section being fed at least by said feedstock or by said hydrogenated effluent from step a) and a gas stream comprising hydrogen, said hydroconversion reaction section being carried out at a temperature between 300 and 450°C, a hydrogen partial pressure between 5.0 and 20.0 MPa abs and an hourly volumetric flow rate between 0.03 and 2.0 h1, to obtain a hydroconverted effluent; c) a separation step, fed with the hydroconverted effluent from step b) and an aqueous solution, said step being carried out at a temperature between 20 and 450°C, to obtain at least one gaseous effluent, one aqueous effluent and one hydrocarbon effluent, d) optionally, a step of fractionation of all or part of the hydrocarbon effluent from step c), to obtain at least one gaseous effluent and at least one hydrocarbon cut comprising compounds having a boiling point less than or equal to 150°C and a hydrocarbon cut comprising compounds having a boiling point greater than 150°C.

2. Process according to claim 1, in which the hydrocarbon effluent from separation step c), or at least one of the two liquid hydrocarbon streams from step d), is sent in whole or in part to a steam cracking step e) carried out in at least one pyrolysis furnace at a temperature between 700 and 900°C and at a pressure between 0.05 and 0.3 MPa relative.

3. Process according to one of the preceding claims wherein when step b) is carried out in an ebullated bed or in a moving bed, said hydroconversion catalyst of step b) comprises a supported catalyst comprising a metal from group VIII chosen from the group formed by Ni, Pd, Pt, Co, Rh and / or Ru, optionally a metal from group VIB chosen from the group Mo and / or W, on an amorphous mineral support chosen from the group formed by alumina, silica, silica-aluminas, magnesia, clays and mixtures of at least two of these minerals, and when step b) is carried out in an entrained bed, said hydroconversion catalyst of step b) comprises a dispersed catalyst containing at least one element chosen from the group formed by Mo, Fe, Ni, W, Co, V, Ru.

4. Method according to one of the preceding claims, comprising a step aO) of pretreatment of the feedstock, said pretreatment step being carried out upstream of step a) of hydrogenation and comprising a filtration step and / or an electrostatic separation step and / or a step of washing using an aqueous solution and / or an adsorption step.

5. Method according to one of the preceding claims, in which the fractionation step d) further comprises a fractionation making it possible to obtain, in addition to a gas stream, a naphtha cut comprising compounds having a boiling point less than or equal to 150°C, and a kerosene cut comprising compounds having a boiling point greater than 150°C and less than or equal to 280°C, a diesel cut comprising compounds having a boiling point greater than 280°C and less than 360°C and a hydrocarbon cut comprising compounds having a boiling point greater than or equal to 360°C, called a heavy hydrocarbon cut.

6. Process according to one of the preceding claims, in which the fractionation step d) further comprises a fractionation of the hydrocarbon cut comprising compounds having a boiling point less than or equal to 150°C into a light naphtha cut comprising compounds having a boiling point less than 80°C and a heavy naphtha cut comprising compounds having a boiling point between 80 and 150°C.

7. A method according to any preceding claim, which further comprises a hydrotreatment step, said hydrotreatment step being carried out before or after separation step c), or after fractionation step d), said hydrotreatment step being 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 with at least a portion of said hydroconverted effluent from step b), or at least a portion of said hydrocarbon effluent from step c) or at least a portion of said hydrocarbon cut comprising compounds having a boiling point greater than 150°C from step d) and a gas stream comprising hydrogen, said hydrotreatment reaction section being carried out at a temperature between 250 and 430°C, a hydrogen partial pressure between 1.0 and 20.0 MPa abs.and an hourly volumetric flow rate between 0.1 and 10.0 h1, to obtain a hydrotreated effluent.

8. Process according to the preceding claim in which said hydrotreatment catalyst comprises a support chosen from the group consisting of 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.

9. Process according to one of claims 7 to 8, which further comprises a hydrocracking step, said hydrocracking step being carried out either after a hydrotreatment step or after the fractionation step d), said hydrocracking step being carried out in a hydrocracking reaction section, using at least one fixed bed 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 hydrotreated effluent and / or with the hydrocarbon cut comprising compounds having a boiling point greater than 150°C from step d) 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 h1, to obtain a hydrocracked effluent.

10. A process according to claim 9, which further comprises a second hydrocracking step carried out in a reaction section- hydrocracking reaction section, implementing at least one fixed bed 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 a hydrocarbon fraction comprising compounds having a boiling point greater than 150°C from the first hydrocracking stage and a gas stream comprising hydrogen, said hydrocracking reaction section being implemented at a 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 h1, to obtain a hydrocracked effluent.

11. Process according to one of claims 9 and 10, in which said hydrocracking catalyst comprises a support chosen from halogenated aluminas, combinations of boron and aluminum oxides, amorphous silica-aluminas and zeolites and a hydro-dehydrogenating function comprising at least one metal from group VIB chosen from chromium, molybdenum and tungsten, alone or in a mixture, and / or at least one metal from group VIII chosen from iron, cobalt, nickel, ruthenium, rhodium, palladium and platinum.

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

13. Process according to one of the preceding claims in which said selective hydrogenation catalyst 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.

14. Method according to one of the preceding claims, in which the feedstock has the following properties: - an aromatic content of between 0 and 90% by weight, - a halogen content of between 2 and 5000 ppm by weight, - a metallic element content of between 10 and 10000 ppm by weight, - including an iron element content of between 0 and 100 ppm by weight, - a silicon element content of between 0 and 1000 ppm by weight, - a heteroelement content provided by sulfur compounds, oxygenated compounds and / or nitrogen compounds of between 0 and 20000 ppm weight.