Method for treating impurity-laden pyrolysis oil from plastics and / or solid recycled fuels

Abstract

The present invention relates to a method for processing pyrolysis oil from plastics and / or solid recovered fuels, comprising the steps of: a) optional selective hydrogenation of the feedstock; b) hydroconversion in an ebullated, entrained and / or moving bed; obtaining a hydroconverted effluent; c) separation of the effluent from step b) in the presence of an aqueous stream; obtaining a gaseous effluent, an aqueous effluent and a hydrocarbon liquid effluent; d) optional fractionation; obtaining at least one gaseous stream and a fraction having a boiling point less than or equal to 150° C. and a fraction having a boiling point greater than 150° C.

Description

[Technical field]

[0001] The present invention relates to a method for the treatment of impurity-laden pyrolysis oils of plastics and / or solid recovery fuels (SRF), at least in part, to obtain a hydrocarbon effluent that can be upgraded by being directly incorporated into naphtha or diesel pools or as a feedstock for a steam cracking unit. More particularly, the present invention relates to a method for the treatment of a feedstock obtained from the pyrolysis of plastic waste and / or SRF, removing at least a portion of the impurities that said feedstock may contain in large amounts and hydrotreating the feedstock to upgrade it. [Background technology]

[0002] The plastics resulting from the collection and sorting channels can undergo a process of pyrolysis to obtain, among other things, pyrolysis oils. These plastic pyrolysis oils are generally incinerated to generate electricity and / or used as fuel in industrial or municipal heating boilers.

[0003] Solid recovered fuels (SRF), also known as "refuse-derived fuels" or RDF, are solid non-hazardous waste materials prepared for energy recovery, whether they are from household and similar waste, waste from economic activity, or construction and demolition waste. SRF is generally a mixture of any combustible waste, such as used tyres, food by-products (fats, animal meals, etc.), viscose and wood waste, light debris from shredders (e.g. used vehicles, electrical and electronic equipment (WEEE), household and commercial waste, residues from the recycling of different types of waste, including certain municipal waste, plastic waste, textiles, and wood, etc. SRF can also consist of only one of these above-mentioned types of waste, such as used tyres. SRF generally contains plastic waste. Currently, SRF are mainly recovered for energy. They can be used directly as a replacement for fossil fuels in co-combustion plants (coal and lignite power plants, cement plants, lime kilns) or household waste incineration units, or indirectly in pyrolysis units dedicated to energy recovery: SRF pyrolysis oil is thus generally burned to generate electricity or further used as fuel in boilers for industrial or urban heating.

[0004] Another route for upgrading the pyrolysis oils of plastics and / or SRF consists in using these pyrolysis oils as feedstock for steam cracking units to (re)produce olefins, said olefins being the constituent monomers of certain polymers. However, plastic waste or SRF is generally a mixture of several polymers, for example a mixture of polyethylene, polypropylene, polyethylene terephthalate, polyvinyl chloride and polystyrene. Furthermore, depending on the application, the plastics may contain, in addition to the polymers, other compounds, for example plasticizers, pigments, dyes or polymerization catalyst residues, as well as other very diverse organic and inorganic impurities from the separation operations in the sorting centers (the selectivity of which may not be complete). The oils obtained from the pyrolysis of plastics or SRF therefore contain many impurities, especially diolefins, metals, silicon or halogenated compounds, especially chlorine-based compounds, heteroelements such as sulfur, oxygen and nitrogen, as well as insolubles, often in high contents that are incompatible with the steam cracking units or with units located downstream of the steam cracking units, especially the polymerization and selective hydrogenation processes. These impurities can cause problems of operability, especially corrosion, coking or catalyst deactivation, or also incompatibility in the use of the target polymer. The presence of diolefins very often causes problems of instability of the pyrolysis oil, characterized by the formation of gums. Gums and insoluble materials that may be present in pyrolysis oil can cause clogging problems in the processing process.

[0005] Furthermore, during the steam cracking process, the yield of light olefins required for petrochemistry, especially ethylene and propylene, is highly dependent on the quality of the feedstock sent to the steam cracking. The BMCI (Bureau of Mines Correlation Index) is often used to characterize the hydrocarbon fractions. This index was developed for the hydrocarbon products obtained from crude oil and is calculated from measurements of density and average boiling point: it is equal to 0 for normal paraffins and 100 for benzene. Its value therefore increases in proportion to the condensed aromatic structure of the product analyzed, naphthenes having an intermediate BMCI between paraffins and aromatics.

[0006] Overall, higher yields of light olefins occur when the paraffin content is higher and therefore the BMCI is reduced, whereas higher yields of undesirable heavy compounds and / or coke occur when the BMCI is increased.

[0007] In the patent application WO 2005 / 023331 A1 a total process for recycling plastic waste is proposed, which is very general and relatively complex, ranging from the very step of pyrolysis of plastic waste to a steam cracking step, which comprises, inter alia, a step of hydrotreating the liquid phase obtained directly from the pyrolysis, preferably under fairly stringent conditions, in particular stringent in terms of temperature, for example at a temperature of 260-300° C., a step of separation of the hydrotreating effluent and a subsequent step of hydrodealkylation of the separated heavy effluent, preferably at high temperature, for example at 260-400° C.

[0008] Due to the content of impurities in pyrolysis oils, deactivation of the catalysts of hydrotreating units operated in fixed beds can be observed, especially when they are highly loaded with impurities, which reduces the cycle time. In fact, the main limitation of fixed bed units is the fact that the units must be shut down to replace the catalyst. Furthermore, pyrolysis oils, especially those with a high impurity loading, can create clogging problems, especially in the preheater furnace, the feed / effluent exchanger or on the bed head of the catalytic reactor.

[0009] It would therefore be advantageous to propose a method for processing pyrolysis oil that has a long lasting catalytic cycle by allowing replacement of the catalyst without shutting down the unit, while at the same time producing an alkane-rich fraction that can be easily upgraded in a steam cracking unit.

[0010] Hydroconversion units operated with ebullated, entrained or even moving beds can process this type of feedstock thanks to systems for adding fresh catalyst and withdrawing spent catalyst without shutting down the unit. The addition of fresh catalyst and withdrawal of spent catalyst are generally carried out continuously, semi-continuously or periodically. These systems compensate for catalyst deactivation caused by impurities in the pyrolysis oil of plastics or SRF, solve the problem of catalyst bed plugging in reactors operated with fixed beds and allow hydroconversion units to have long cycle times without the need to shut down for catalyst replacement.

[0011] The unpublished patent application FR 20 / 09.750 describes such a method for treating pyrolysis oils of plastics and / or SRF, which method comprises, inter alia: a) optionally, a step of selective hydrogenation of said feedstock in the presence of hydrogen and a selective hydrogenation catalyst; obtaining a hydrogenated effluent; b) a step of hydroconversion using at least one ebullated bed reactor, entrained bed reactor and / or moving bed reactor containing at least one hydroconversion catalyst, said hydroconversion reaction section being fed at least with said feedstock or said hydrogenated effluent obtained from step a) and a gas stream containing hydrogen; obtaining a hydroconverted effluent; c) a separation step, feeding the hydroconverted effluent from step b) and an aqueous solution, said step being carried out at a temperature between 50 and 450°C; obtaining at least one gaseous effluent, an aqueous effluent and a hydrocarbon effluent; d) fractionating all or a portion of the hydrocarbon effluent obtained from step c) to obtain at least one gas stream, a hydrocarbon fraction comprising compounds having a boiling point less than or equal to 385° C. and a hydrocarbon fraction comprising compounds having a boiling point greater than 385° C.; e) a hydrotreating step, using at least one fixed bed reactor containing at least one hydrotreating catalyst, said hydrotreating reaction section being fed with at least a portion of said hydrocarbon fraction containing compounds having a boiling point below 385° C. from step d) and with a gas stream containing hydrogen; obtaining a hydrotreated effluent; f) a separation step, which is fed with the hydrotreated effluent obtained from step e) to obtain at least a gaseous effluent and a hydrotreated liquid hydrocarbon effluent.

[0012] Unpublished patent application FR 21 / 04873, which is based on the process of FR 20 / 09750, describes another process for treating pyrolysis oils of plastics and / or SRF, in which a hydroconversion step using at least one ebullated bed reactor, entrained bed reactor 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 and hydrotreatment steps.

[0013] As a result of research, the applicant has surprisingly come to the discovery that it is possible to simplify the existing process by omitting the hydrotreating step after the hydroconversion step. By applying more severe operating conditions in the hydroconversion step and / or choosing a very active catalyst, it is possible to obtain a pyrolysis oil, which can be directly upgraded by blending it into the fuel pool and / or can be directly adapted for processing in a steam cracking unit, without the need to carry out a hydrotreating step after hydroconversion. This is because, through the choice of operating conditions and / or appropriate catalysts, the hydrotreating reactions, in particular hydrodenitrification, are fully carried out in the hydroconversion step. [Prior art documents] [Patent documents]

[0014] [Patent Document 1] International Publication No. 2018 / 055555 Summary of the Invention [Means for solving the problem]

[0015] (Summary of the invention) The present invention relates to a method for processing a feedstock comprising pyrolysis oil of plastics and / or solid recycled fuels, the method comprising the following steps, preferably in the given order: a) an optional selective hydrogenation step, carried out in the presence of at least one selective hydrogenation catalyst in at least a reaction section fed with said feedstock and a gas stream containing hydrogen, the temperature being between 100 and 280° C., the partial pressure of hydrogen being between 1.0 and 20.0 MPa (abs) and the hourly space velocity being between 0.3 and 10.0 h -1 to obtain a hydrogenated effluent; b) a hydroconversion step, carried out in a hydroconversion reaction section using at least one ebullated bed reactor, entrained bed reactor and / or moving bed reactor, containing at least one hydroconversion catalyst, said hydroconversion reaction section being fed at least with said feedstock or said hydrogenated effluent obtained from step a) and a gas stream containing hydrogen, said hydroconversion reaction section being operated at a temperature between 300 and 450° C., with a partial pressure of hydrogen between 5.0 and 20.0 MPa (abs), and with an hourly space velocity between 0.03 and 2.0 h -1 obtaining a hydroconverted effluent; c) a separation step, feeding the hydroconverted effluent from step b) and an aqueous solution, said step being carried out at a temperature between 20 and 450° C.; obtaining at least one gaseous effluent, an aqueous effluent and a hydrocarbon effluent; d) optionally fractionating all or part of the hydrocarbon effluent obtained from step c); obtaining at least one gaseous effluent, at least one hydrocarbon fraction comprising compounds having a boiling point less than or equal to 150° C. and at least one hydrocarbon fraction comprising compounds having a boiling point greater than 150° C.

[0016] In the following text, the term "pyrolysis oil" means, unless otherwise stated, oil obtained from the pyrolysis of plastics and / or SRF.

[0017] One advantage of the process according to the invention is that it purifies the pyrolysis oil from at least a portion of its impurities, making it possible to hydrogenate it and therefore upgrade it, in particular by incorporating it directly into the fuel pool and / or adapting it to a treatment in a steam cracking unit in order to be able to obtain in particular light olefins that may function as monomers in the manufacture of polymers.

[0018] Another advantage of the present invention is that it prevents the risk of clogging and / or corrosion of the processing units in which the method of the present invention is carried out, which risk is exacerbated by the presence (often in large amounts) of diolefins, metals and halogenated compounds in the pyrolysis oil.

[0019] The process of the invention thus makes it possible to obtain a hydrocarbon effluent obtained from pyrolysis oil, which is free of the impurities of the starting pyrolysis oil, thus limiting the operability problems, such as corrosion, coking or catalyst deactivation, that these impurities may cause, in particular in the steam cracking unit and / or in the units located downstream of the steam cracking unit, in particular in the polymerization and selective hydrogenation units. The removal of at least a portion of the impurities from the pyrolysis oil also makes it possible to increase the range of applications of the target polymer, the incompatibility of the applications being reduced.

[0020] Carrying out the hydroconversion process with a system for adding fresh catalyst and withdrawing spent catalyst without shutting down the unit makes it particularly possible to process pyrolysis oils heavily loaded with impurities.

[0021] By carrying out the hydroconversion step using a system for adding fresh catalyst and withdrawing spent catalyst without shutting down the unit, it is also possible to convert at least a portion of the heavy compounds to lighter compounds, thereby obtaining an improved yield of a fraction suitable for a steam cracking unit and, if this fraction is sent for steam cracking, an improved yield of light olefins.

[0022] Furthermore, the process according to the invention is characterized in that it does not require any hydrotreating step after the hydroconversion step, which represents a saving in terms of reactors, equipment and energy.

[0023] According to one variant, the hydrocarbon effluent obtained from the separation step c) or at least one of the two liquid hydrocarbon streams obtained from step d) is sent, in whole or in part, to a steam cracking step e), which is carried out in at least one pyrolysis furnace at a temperature of 700-900° C. and a pressure of 0.05-0.3 MPa (relative).

[0024] According to one variant, when step b) is carried out in an ebullated or moving bed, said hydroconversion catalyst of step b) comprises a supported catalyst comprising a group VIII metal selected from the group formed by Ni, Pd, Pt, Co, Rh and / or Ru, and optionally a group VIB metal selected from the group formed by Mo and / or W, on an amorphous mineral support selected from the group formed by alumina, silica, silica-alumina, magnesia, clay and mixtures of at least two of these minerals; 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 selected from the group formed by Mo, Fe, Ni, W, Co, V and Ru.

[0025] According to one variant, the process comprises a step a0) of pretreating the feedstock, said pretreatment step being carried out upstream of the hydrogenation step a) and comprising a filtration step and / or an electrostatic separation step and / or a washing step with an aqueous solution and / or an adsorption step.

[0026] According to one variant, the fractionation step d) also comprises a fractionation making it possible to obtain, in addition to the gas stream, a naphtha fraction comprising compounds having a boiling point below 150° C., a kerosene fraction comprising compounds having a boiling point above 150° C. and below 280° C., a diesel fraction comprising compounds having a boiling point above 280° C. and below 360° C. and a hydrocarbon fraction comprising compounds having a boiling point above 360° C., known as the heavy hydrocarbon fraction.

[0027] According to one variant, the fractionation step d) also comprises fractionating the hydrocarbon fraction comprising compounds having a boiling point below 150°C, to give a light naphtha fraction comprising compounds having a boiling point below 80°C and a heavy naphtha fraction comprising compounds having a boiling point between 80 and 150°C.

[0028] According to one variant, the process also comprises a hydrotreating step, which is carried out before or after the separation step c) or else after the fractionation step d), said hydrotreating step being carried out in a hydrotreating reaction section, carrying out at least one fixed bed reactor with n catalyst beds, n being an integer greater than or equal to 1, each containing at least one hydrotreating catalyst, said hydrotreating reaction section being fed with at least a portion of the hydroconverted effluent from step b) or at least a portion of the hydrocarbon effluent obtained from step c) or at least a portion of the hydrocarbon fraction obtained from step d) comprising compounds with a boiling point above 150° C., and with a gas stream comprising hydrogen, said hydrotreating reaction section being carried out at a temperature between 250 and 430° C., with a hydrogen partial pressure between 1.0 and 20.0 MPa (abs) and with an hourly volumetric rate between 0.1 and 10.0 h -1 and obtaining a hydrotreated effluent.

[0029] According to this variant, the hydrotreating catalyst comprises a support selected from the group consisting of alumina, silica, silica-alumina, magnesia, clay and mixtures thereof, and a hydrodehydrogenation functional group comprising at least one element from group VIII and / or at least one element from group VIB.

[0030] According to one variant, the process also comprises a hydrocracking step, which is carried out either after the hydrotreating step or after the fractionation step d), said hydrocracking step being carried out in a hydrocracking reaction section using at least one fixed bed containing n catalyst beds, n being an integer equal to or greater than 1, each containing at least one hydrocracking catalyst, said hydrocracking reaction section being fed with at least a portion of said hydrotreated effluent and / or a hydrocarbon fraction obtained from step d) comprising compounds with a boiling point above 150° C., and a gas stream comprising hydrogen, said hydrocracking reaction section being used at an average temperature between 250 and 450° C., the partial pressure of hydrogen being between 1.5 and 20.0 MPa (abs) and the hourly space velocity being between 0.1 and 10.0 h -1 and obtaining a hydrocracked effluent.

[0031] According to this variant, the process also comprises a second hydrocracking step, which is carried out in a hydrocracking reaction section using at least one fixed bed containing n catalyst beds, n being an integer equal to or greater than 1, each containing at least one hydrocracking catalyst, said hydrocracking reaction section being fed with a hydrocarbon fraction containing compounds with a boiling point above 150° C. obtained from the first hydrocracking step and a gas stream containing hydrogen, the temperature at which said hydrocracking reaction section is used being between 250 and 450° C., the partial pressure of hydrogen being between 1.5 and 20.0 MPa (abs) and the hourly space velocity being between 0.1 and 10.0 h -1 and obtaining a hydrocracked effluent.

[0032] According to one variant, the hydrocracking catalyst comprises a support chosen from halogenated aluminas, combinations of oxides of boron and aluminium, amorphous silica-alumina and zeolites, and a hydrodehydrogenation functional group comprising at least one metal from group VIB chosen alone or in mixtures from chromium, molybdenum and tungsten, and / or at least one metal from group VIII chosen from iron, cobalt, nickel, ruthenium, rhodium, palladium and platinum.

[0033] According to one variant, the process comprises said selective hydrogenation step a).

[0034] According to one variant, the selective hydrogenation catalyst comprises a support chosen from alumina, silica, silica-alumina, magnesia, clay and mixtures thereof, and a hydrodehydrogenation functional group 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.

[0035] According to one variant, the feedstock has the following characteristics: - the content of aromatic compounds is 0 to 90% by weight; - the content of halogenated compounds is 2 to 5000 ppm by weight; - the content of metallic elements is 10 to 10,000 ppm by weight; - containing iron element, the content of which is 0 to 100 ppm by weight; - The content of silicon element is 0 to 1000 ppm by weight; the content of heteroelements provided by sulfur compounds, oxygen compounds and / or nitrogen compounds is between 0 and 20,000 ppm by weight;

[0036] The present invention also relates to products which may be obtained via the process according to the invention.

[0037] According to one variant, the product comprises, relative to the total weight of the product: - The total content of metallic elements is less than or equal to 10.0 ppm by weight; - Contains iron element, the content of which is 200 ppb by weight or less; - The content of silicon element is 5.0 ppm by weight or less; - The sulfur content is less than or equal to 500 ppm by weight; - the nitrogen content is less than or equal to 50 ppm by weight; - The chlorine content is 10 ppm by weight or less.

[0038] According to the invention, pressure is absolute pressure, also expressed as abs., and is given in MPa absolute (or MPa(abs)), unless otherwise indicated.

[0039] According to the present invention, the expressions "of between A and B" and "between A and B" are equivalent and mean that both limits of the interval (A, B) are included in the stated range of values. If this is not the case and if both limits are not included in the stated range, such an explanation is introduced by the present invention.

[0040] For the purposes of the present invention, various ranges of parameters for a given process, such as pressure ranges and temperature ranges, may be used alone or in combination, for example, a range of preferred pressure values ​​may be combined with a more preferred range of temperature values ​​within the meaning of the present invention.

[0041] In the following text, specific and / or preferred embodiments of the present invention may be described, which may be implemented separately or in combination together, without limitation to combinations where technically feasible.

[0042] The groups of chemical elements are then given according to the CAS classification (CRC Handbook of Chemistry and Physics, published by CRC Press, editor DR Lide, 81st edition, 2000-2001). For example, group VIII according to the CAS classification corresponds to the metals in columns 8, 9 and 10 according to the new IUPAC classification.

[0043] The metal content is measured by X-ray fluorescence. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0044] (List of Drawings) The information regarding the elements referenced in Figure 1 allows for a better understanding of the invention, but said invention is not limited to the specific embodiment illustrated in Figure 1. The various embodiments presented may be used alone or in combination with each other, without any limitations on the combinations.

[0045] (Detailed Description) (Feed material) According to the invention, "plastic pyrolysis oil or SRF pyrolysis oil" is an oil obtained from the pyrolysis of plastics, preferably plastic waste, especially originating from collection and sorting channels or from the pyrolysis of SRF, for example from the pyrolysis of used tires, advantageously in liquid form at ambient temperature. It comprises in particular a mixture of hydrocarbon compounds, in particular paraffins, olefins, naphthenes, aromatics. The boiling point of at least 80% by weight of these hydrocarbon compounds is preferably below 700°C, 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, with the sum of paraffins, olefins and aromatics being understood to be 100% by weight of hydrocarbon compounds.

[0046] The density of pyrolysis oil is generally between 0.75 and 0.99 g / cm, measured at 15 °C according to ASTM D4052 method. 3 , preferably 0.75 to 0.95 g / cm 3 It is.

[0047] Pyrolysis oil may contain, and usually contains, impurities such as metals, especially iron, silicon, or halogenated compounds, especially chlorinated compounds. These impurities may be present in high concentrations in pyrolysis oil, for example halogen elements provided by halogenated compounds up to 500 ppm by weight, even up to 1000 ppm by weight, even up to 5000 ppm by weight, and metallic or semimetallic elements up to 2500 ppm by weight, even up to 10,000 ppm by weight. Alkali metals, alkaline earth metals, transition metals, post-transition metals and metalloids may be placed in the same category as metallic contaminants, and are called metals or metallic or semimetallic elements. Pyrolysis oil may contain up to 200 ppm by weight, even up to 1000 ppm by weight of silicon, and up to 15 ppm by weight, even up to 100 ppm by weight of iron. The pyrolysis oil may also contain other impurities, such as heteroelements, provided in particular by sulfur compounds, oxygen compounds and / or nitrogen compounds, generally having a content of less than 20,000 ppm by weight of heteroelements, preferably less than 10,000 ppm by weight of heteroelements.

[0048] The method according to the invention is particularly suitable for treating pyrolysis oils loaded with impurities, which means a feedstock having the following characteristics: the aromatic content is between 0 and 90% by weight, often between 20% and 90% by weight, and may be between 50% and 90% by weight; the halogen content is between 2 and 5000 ppm by weight, often between 200 and 5000 ppm by weight, and may be between 500 and 5000 ppm by weight; the content of metallic elements is between 10 and 10,000 ppm by weight, often between 2000 and 10,000 ppm by weight, and may be between 2250 and 5000 ppm by weight; - containing elemental iron, the content of which is between 0 and 100 ppm by weight, often between 10 and 100 ppm by weight, and may be between 15 and 100 ppm by weight; the silicon element content is between 0 and 1000 ppm by weight, often between 100 and 1000 ppm by weight, and may be between 200 and 1000 ppm by weight; the content of heteroelements, in particular those provided by sulfur compounds, oxygen compounds and / or nitrogen compounds, is between 0 and 20,000 ppm by weight, often between 1000 and 10,000 ppm by weight;

[0049] The process according to the invention is particularly suitable for treating pyrolysis oils heavily laden with impurities, which means a feedstock having the following characteristics: - the content of aromatic compounds is between 30% and 70% by weight; - the content of halogenated compounds is from 500 to 5000 ppm by weight; - the content of metallic elements is 300-10,000 ppm by weight; - the metallic element includes iron element, the content of which is 15 to 100 ppm by weight; - the content of silicon element is 200-1000 ppm by weight; the content of heteroelements, in particular those provided by sulfur compounds, oxygen compounds and / or nitrogen compounds, is between 1000 and 10,000 ppm by weight;

[0050] The feedstock for the process according to the invention comprises at least one plastic and / or pyrolysis oil of SRF. The feedstock may consist exclusively of one or more pyrolysis oils of plastics or of one or more pyrolysis oils of SRF or of a mixture of plastics and one or more pyrolysis oils of SRF. Preferably, the feedstock comprises at least 50% by weight, preferably 50% to 100% by weight, particularly preferably 75% to 100% by weight, of plastics and / or pyrolysis oil of SRF.

[0051] The pyrolysis oils of plastics and / or SRF may be obtained from the process of thermal, catalytic pyrolysis or else may be prepared by hydropyrolysis (pyrolysis in the presence of a catalyst and hydrogen).

[0052] The feedstock for the process according to the invention may comprise a feedstock obtained from the conversion of conventional petroleum-based feedstocks and / or biomass and then co-processed with plastics and / or SRF pyrolysis oil.

[0053] The conventional petroleum-based feedstock may advantageously be a fraction or a mixture of fractions of the naphtha, vacuum gas oil, atmospheric residue or vacuum residue type.

[0054] The feedstock resulting from the conversion of biomass may advantageously be chosen from vegetable oils, oils from algae or algae oils, fish oils, waste cooking oils, and fats of vegetable or animal origin, or mixtures of such feedstocks. The vegetable oils may advantageously be crude or refined, and may come completely or partially from plants chosen from rapeseed, sunflower, soybean, palm, olive, coconut, copra, castor oil plants, cotton plants, peanut oil, linseed oil and sea kale oil, and all oils derived from sunflower or rapeseed, for example by genetic modification or breeding, although this list is not limiting. The animal fats are advantageously chosen from fats composed of fats and residues from the food industry or fats derived from the catering industry. Frying oils, various animal oils, for example fish oil, tallow or lard, may also be used.

[0055] The feedstock resulting from the conversion of biomass can also be selected from feedstocks originating from processes for thermal or catalytic conversion of biomass and / or organic waste, for example oils derived from biomass, in particular lignocellulosic biomass, by various liquefaction processes, for example hydrothermal liquefaction or pyrolysis. The term "biomass" refers to material derived from recently living organisms, including 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 aromatic polymers (lignin).

[0056] The feedstock resulting from the conversion of biomass can also advantageously be chosen from feedstocks resulting from the paper industry.

[0057] (Preprocessing (optional)) Said feedstock comprising pyrolysis oil may advantageously be pretreated in an optional pretreatment step a0), prior to the optional selective hydrogenation step a) or, if step a) is not present, the hydroconversion step b), to obtain a pretreated feedstock, which is fed to step a) or step b).

[0058] This optional pretreatment step a0) makes it possible to reduce the amount of contaminants, in particular the amount of silicon and metals, that may be present in the feedstock comprising pyrolysis oil. The optional step a0) of pretreatment of the feedstock comprising pyrolysis oil may therefore be carried out in particular when said feedstock comprises more than 50 ppm by weight, in particular more than 100 ppm by weight and more particularly more than 200 ppm by weight of metallic elements.

[0059] Said optional pretreatment step a0) may be carried out by any method known to the person skilled in the art making it possible to reduce the amount of contaminants. It may in particular comprise a filtration step and / or an electrostatic separation step and / or a step of washing with an aqueous solution and / or an adsorption step.

[0060] The optional pretreatment step a0) is advantageously carried out at a temperature of 0 to 150° C., preferably 5 to 100° C., and at a pressure of 0.15 to 10.0 MPa (abs), preferably 0.2 to 1.0 MPa (abs).

[0061] According to a variant, said optional pretreatment step a0) is carried out in an adsorption section which is operated in the presence of at least one adsorbent, preferably of the alumina type and having a specific surface area of ​​at least 100 m 2 / g or more, preferably 200m 2 The specific surface area of ​​said at least one adsorbent is advantageously greater than or equal to 600 m2 / g or less, especially 400m 2 The specific surface area of ​​the adsorbent is the specific surface area measured by the BET method, i.e. the specific surface area determined by nitrogen adsorption according to standard ASTM D 3663-78, which is derived from the Brunauer-Emmett-Teller method described in the periodical The Journal of the American Chemical Society, 6Q, 309 (1938).

[0062] Advantageously, said adsorbent contains less than 1% by weight of metallic elements, preferably it is devoid of metallic elements. Metallic elements of the adsorbent should be understood as meaning elements from groups 6 to 10 of the Periodic Table of the Elements (new IUPAC classification). The residence time of the feedstock in the adsorbent section is generally between 1 and 180 minutes.

[0063] The adsorption section of optional step a0) comprises at least one adsorption column, preferably at least two adsorption columns, preferentially 2 to 4 adsorption columns, containing the adsorbent. When the adsorption section comprises two adsorption columns, one operation mode can be a "swing" operation, where one of the columns is online, i.e. in operation, while the other column is in reserve. When the adsorbent in the online column is used up, this column is isolated, while the in-reserve column is placed online, i.e. in operation. The used adsorbent can then be regenerated in situ and / or replaced with fresh adsorbent, and the column containing it can again be replaced and placed back online where the other column was isolated.

[0064] Another mode of operation is to have at least two columns operating in series. When the adsorbent of the first column is worn out, this first column is isolated and the spent adsorbent is either regenerated in situ or replaced with fresh adsorbent. The column is then put back on-line in the last position, and so on. This operation is known as the sequence variable mode, or by the term "PRS" for Permutable Reactor System, or alternatively "lead-lag". The combination of at least two adsorption columns makes it possible to overcome possible rapid poisoning and / or clogging of the adsorbent due to the combined action of metallic contaminants, diolefins, gums derived from diolefins and insolubles that may be present in the pyrolysis oil to be treated. This is because the presence of at least two adsorption columns advantageously facilitates replacement and / or regeneration of the adsorbent without shutdown of the pretreatment unit, indeed of the process, which therefore makes it possible to reduce the risk of clogging and therefore to avoid shutdowns of the unit due to clogging, to control costs and to limit the consumption of adsorbent.

[0065] According to another variant, said optional pretreatment step a0) is carried out in a section for washing with an aqueous solution, for example water or an acidic or basic solution. This washing section can comprise equipment making it possible to contact the feedstock with the aqueous solution and to separate the phases in order to obtain, on the one hand, a pretreated feedstock and, on the other hand, an aqueous solution containing impurities. These equipment can comprise, for example, stirred reactors, decanters, mixer-decanters and / or cocurrent or countercurrent scrub washing columns.

[0066] Said optional pretreatment step a0) may optionally be fed with at least a portion of a recycle stream, advantageously obtained from step c) or step d) of the present process, either in a mixture with the feedstock comprising pyrolysis oil or separately therefrom.

[0067] Said optional pretreatment step a0) therefore makes it possible to obtain a pretreated feedstock which is then fed to the selective hydrogenation step a), if present, or to the hydroconversion step b).

[0068] (Selective hydrogenation step a) (optional) According to the invention, the process may comprise a step a) of selective hydrogenation of the feedstock comprising pyrolysis oil, carried out in the presence of hydrogen, under conditions of hydrogen pressure and temperature making it possible to maintain said feedstock in the liquid phase, with the exact amount of soluble hydrogen required for the selective hydrogenation of the diolefins present in the pyrolysis oil. The selective hydrogenation of diolefins in the liquid phase therefore makes it possible to avoid or at least limit the formation of "gums", i.e. the polymerization of diolefins and therefore the formation of oligomers and polymers. Styrene compounds, in particular styrene, may be present in the feedstock, which may also behave like diolefins with respect to the formation of gums, due to the fact that the double bond of the vinyl group is conjugated with an aromatic nucleus. The 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 optionally styrene compounds.

[0069] According to the invention, the selective hydrogenation step a) is carried out in a reaction section which is fed at least with the feedstock comprising the pyrolysis oil or with a pretreated feedstock obtained from the optional pretreatment step a0) and with a gas stream comprising hydrogen (H2).

[0070] Optionally, said reaction section of step a) may likewise be fed with a recycle stream, advantageously at least a part of the recycle stream obtained from step c) and / or step d).

[0071] The reaction section comprises a selective hydrogenation, preferably carried out in a fixed bed, in the presence of at least one selective hydrogenation catalyst, wherein the average temperature (or WABT as defined below) is advantageously between 100 and 280°C, preferably between 120 and 260°C, preferably between 130 and 250°C, the hydrogen partial pressure is advantageously between 1.0 and 20.0 MPa (abs), preferably between 5.0 and 15.0 MPa (abs), and the hourly space velocity (HSV) is advantageously between 0.3 and 10.0 h -1 , preferably 0.5 to 5.0 h -1 It is.

[0072] According to the invention, the "average temperature" of the reaction section containing at least one fixed bed reactor corresponds to the weight-average bed temperature (WABT), which is well known to the person skilled in the art. The average temperature is advantageously determined depending on the catalyst system used, the equipment and their configuration. The average temperature (or WABT) is calculated in the following way:

[0073]

number

[0074] In the formula, T inlet : temperature of the effluent at the inlet of the reaction section, T outlet : The temperature of the effluent at the outlet of the reaction section.

[0075] Hourly space velocity (HSV) is defined herein as the ratio of the hourly volumetric flow rate of the feedstock, including pyrolysis oil, optionally pretreated pyrolysis oil, to the volume of the catalyst or catalysts.

[0076] The amount of gas stream containing hydrogen (H2) fed to said reaction section of step a) is advantageously determined so that the hydrogen coverage is equal to or greater than the feed volume (m 3 ) Hydrogen 1-200Sm 3 (Sm 3 / m 3 ), preferably the feedstock volume (m 3) Hydrogen 1~50Sm 3 (Sm 3 / m 3 ), preferably the feedstock volume (m 3 ) Hydrogen 5~20Sm 3 (Sm 3 / m 3 ) is set to be.

[0077] Hydrogen coverage is defined as the ratio at 15°C of the volumetric flow rate of hydrogen obtained under standard temperature and pressure conditions relative to the volumetric flow rate of the "fresh" feed, i.e. the feed to be treated, possibly pretreated, not taking into account possible recycled fractions (per volume of feed (m 3 ) per m of H2 standard 3 (Sm 3 (Indicated by).

[0078] The hydrogen-containing gas stream feeding the reaction section of step a) may consist of a hydrogen feed and / or recycled hydrogen, advantageously recycled hydrogen obtained from step c) and / or step d).

[0079] The selective hydrogenation step a) is preferably carried out in a fixed bed. It can also be carried out in an ebullated or moving bed.

[0080] Advantageously, the reaction section of step a) comprises 1 to 5 reactors. According to a particular embodiment of the invention, the reaction section comprises 2 to 5 reactors, operated in a permutable manner, also referred to by the term PRS (Permutable Reactor System) or otherwise by "Lead-lag". The combination of at least two reactors in a PRS mode allows isolating the reactors, discharging the spent catalyst, recharging the reactors with fresh catalyst and returning said reactors to operation without shutting down the process. The PRS technology is particularly described in patent FR 2 681 871.

[0081] According to a particularly preferred variant, the selective hydrogenation reaction section of step a) comprises two reactors operated in variable sequence mode.

[0082] Advantageously, reactor internals can be used to prevent clogging of the reactor or reactors, for example internals of the filter plate type. Examples of filter plates are described in patent FR 3 051 375.

[0083] Advantageously, said selective hydrogenation catalyst comprises a support, preferably a mineral support, and a hydrodehydrogenation functional group.

[0084] According to a variant, the hydrodehydrogenation functional group comprises in particular at least one element from group VIII and at least one element from group VIB, the at least one element from group VIII being preferably selected from nickel and cobalt, and the at least one element from group VIB being preferably selected from molybdenum and tungsten. According to this variant, the total content of metal elements from groups VIB and VIII, expressed as oxides, is preferably between 1% and 40% by weight, preferentially between 5% and 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.

[0085] The weight ratio of one or more metals from group VIB relative to one or more metals from group VIII, expressed as metal oxides, is preferably 1-20, suitably 2-10.

[0086] According to this variant, the reaction section of step a) for example comprises a hydrogenation catalyst comprising 0.5% to 12% by weight of nickel (expressed as nickel oxide NiO relative to the weight of the catalyst), preferably 1% to 10% by weight of nickel, and 1% to 30% by weight of molybdenum (expressed as molybdenum oxide MoO3 relative to the weight of the catalyst), preferably 3% to 20% by weight of molybdenum, preferably on an inorganic support, preferably on an alumina support.

[0087] According to another variant, the hydrodehydrogenation functional group comprises, preferably consists 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 the catalyst. This type of catalyst is preferably used in its reduced form, preferably on an inorganic support, preferably on an alumina support.

[0088] The support of the at least one selective hydrogenation catalyst is preferably selected from alumina, silica, silica-alumina, magnesia, clay and mixtures thereof. The support may contain a dopant compound, in particular an oxide selected from boron oxide, in particular boron trioxide, zirconia, ceria, titanium oxide, phosphorus pentoxide and mixtures thereof. Preferably, the at least one selective hydrogenation catalyst comprises an alumina support, possibly doped with phosphorus and optionally with boron. If present, the concentration of phosphorus pentoxide P2O5 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. If present, the concentration of boron trioxide B2O5 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. The alumina used can be, for example, γ (gamma) or η (eta) alumina.

[0089] The selective hydrogenation catalyst is, for example, in the form of extrudates.

[0090] Highly preferably, in order to hydrogenate diolefins as selectively as possible, step a) may use at least one selective hydrogenation catalyst used in step a) which, in addition to the selective hydrogenation catalysts described above, contains 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 the 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 the catalyst, on an alumina support. This catalyst, with a modest metal loading, is preferably placed upstream of the selective hydrogenation catalyst described above.

[0091] The content of impurities, especially diolefins, of the hydrogenated effluent obtained at the end of step a) is reduced relative to the content of the same impurities, especially diolefins, contained in the feedstock of the process.The selective hydrogenation step a) generally allows for conversion of at least 90%, preferably at least 99%, of the diolefins contained in the initial feedstock.The step a) also allows for at least partial removal of other contaminants, such as silicon.The hydrogenated effluent obtained at the end of the selective hydrogenation step a) is preferably sent directly to hydroconversion step b).

[0092] (Hydroconversion step b) According to the invention, the process comprises a hydroconversion step b), which is carried out in a hydroconversion reaction section, comprising at least one ebullated bed reactor, entrained bed reactor and / or moving bed reactor, containing at least one hydroconversion catalyst, said hydroconversion reaction section being fed at least with said feedstock or said hydrogenated effluent obtained from step a) to obtain a hydroconverted effluent.

[0093] Advantageously, step b) comprises hydroconversion reactions well known to the person skilled in the art, more particularly hydrotreating reactions, such as hydrogenation of olefins, aromatics, halogenated compounds, hydrodemetallization, hydrodesulfurization, hydrodenitrification, etc., and hydrocracking reactions leading to the opening of naphthenic rings (HCK) or fractionation of paraffins into several fragments of lower molecular weight, pyrolysis and polycondensation reactions (formation of coke), although polycondensation reactions are not desired.

[0094] Advantageously, said hydroconversion reaction section is operated at a pressure equivalent to that used in the reaction section of the selective hydrogenation step a), if present, but at a temperature higher than that of the reaction section of the selective hydrogenation step a). Thus, said hydroconversion reaction section, regardless of whether it uses ebullated bed, entrained bed and / or moving bed reaction sections, advantageously has a hydroconversion temperature of 300-450°C, preferably 350-420°C, a hydrogen partial pressure of 5.0-20.0 MPa (abs), more preferentially 6.0-15.0 MPa (abs), an hourly space velocity (HSV) of 0.03-2.0 h -1 , preferably 0.1 to 1.0 h -1 It is operated with.

[0095] According to the invention, the "hydroconversion temperature" corresponds to the average temperature in the hydroconversion reaction section of step b). The hydroconversion temperature is advantageously determined by the skilled person depending on the catalyst system, the installation and its configuration. For example, the ebullated bed hydroconversion temperature is determined by taking the arithmetic mean of the temperature measurements in the catalyst bed. The hourly space velocity (HSV) is defined here as the ratio of the hourly flow rate by the volume of hydrogenated effluent resulting from step a) per volume of catalyst(s). The hydrogen coverage in step b) is advantageously determined by the volume of fresh feedstock (m 3 ) Hydrogen 50~1000Sm 3 , preferably the volume of fresh feedstock (m 3 ) Hydrogen 60~500Sm 3 , preferably the volume of fresh feedstock (m 3) Hydrogen 100~300Sm 3 The hydrogen coverage is defined as the ratio of the volumetric flow rate of hydrogen taken under standard temperature and pressure conditions to the volumetric flow rate at 15°C of the "fresh" feed, i.e. the feed to be treated (possibly pretreated feed), without taking into account possible recycled portions (per volume of feed (m 3 ) per m of H2 standard 3 (Sm 3 The hydrogen-containing gas stream fed to the reaction section of step b) may consist of a hydrogen feed and / or recycled hydrogen, advantageously obtained from step c) and / or step d).

[0096] An important feature of the process according to the invention is the fact that the hydroconversion step is carried out in a reaction section which allows the addition of fresh catalyst and the withdrawal of spent catalyst without shutting down the unit. Such systems are hydroconversion units operated in an ebullated bed, in an entrained bed and / or even in a moving bed. The addition of fresh catalyst and the withdrawal of spent catalyst can therefore be carried out continuously, semi-continuously or periodically.

[0097] The operating conditions used in the 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, to a product having a minimum of 80% by weight of compounds having a boiling point below 150° C.

[0098] Advantageously, the hydroconversion step allows hydrogenation of at least 80%, preferably all, of the remaining olefins, but also allows at least partial conversion of other impurities present in the feedstock, such as aromatic compounds, metal compounds, sulfur compounds, nitrogen compounds, halogenated compounds (especially 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 allow further reduction of the contaminant content, such as the metal content, especially the silicon content.Preferably, the metal content at the outlet of step b) is less than 10 ppm by weight, preferably less than 2 ppm by weight, and the silicon content is less than 5 ppm by weight.

[0099] By applying very severe operating conditions in the hydroconversion step and / or by choosing a very active catalyst, it is possible to obtain at least one hydrocarbon fraction which can be directly upgraded by incorporating it in the fuel pool and / or which is directly suitable for processing in a steam cracking unit without the need to carry out a hydrotreating step after hydroconversion, because through the operating conditions and / or the choice of a suitable catalyst, the hydrotreating reactions, in particular hydrodenitrification, are sufficiently carried out in the hydroconversion step.

[0100] (Ebullated bed hydroconversion process b) Therefore, according to a first variant, the hydroconversion step b) is carried out in a hydroconversion reaction section comprising at least one ebullated bed reactor.

[0101] The functioning of ebullated bed reactors is generally known, including the recycling of the reactor liquid upwards through a stirred bed of catalyst. A mixture of feedstock and hydrogen is passed from the bottom up over a bed of catalyst particles, with a flow rate such that the particles are subjected to a forced random motion, causing liquid and gas to pass through the bed from the bottom up. The movement of the catalyst bed is controlled by the flow of the recycled liquid, so that, under steady conditions, the catalyst mass does not rise above a definable level in the reactor. The hydrogenated vapors and liquid pass through the upper level of the bed of catalyst particles, reaching a zone substantially free of catalyst, which are then discharged from the top of the reactor. A portion of the reactor liquid is continuously recycled to the reactor. The ebullated bed technology uses supported catalysts, generally in the form of extrudates or beads, the diameter of which is generally of the order of 1 mm or less. The catalyst remains inside the reactor and is not discharged with the product. The catalyst activity can be kept constant by online replacement of the catalyst. It is thus not necessary to shut down the unit to replace the spent catalyst or to increase the reaction temperature along the cycle to compensate for deactivation. Moreover, operation under constant operating conditions makes it possible to obtain constant product yields and qualities along the cycle. Also, because the catalyst is kept stirred by significant liquid recycle, the pressure drop over the reactor remains low and constant, and the heat release of the reaction is quickly averaged over the catalyst bed.

[0102] The spent catalyst is partially replaced with fresh catalyst at regular time intervals, i.e. for example bursty or almost continuously, by withdrawing it from the bottom of the reactor and introducing fresh or new catalyst either at the top of the reactor or at the bottom of the reactor. Fresh catalyst can be introduced, for example, daily. The rate of exchange of spent catalyst with fresh catalyst can be, for example, from about 0.01 kilograms to about 10 kilograms per cubic meter of feedstock. This withdrawal and this exchange is carried out with a device that allows the continuous functioning of this hydroconversion step. This unit usually includes an internal recirculation pump to maintain the catalyst in a boiling bed by continuous recycling of at least a portion of the liquid withdrawn at the top of the reactor and reinjected at the bottom of the reactor. It is also possible to send the spent catalyst withdrawn from the reactor to a regeneration zone, where the carbon and sulfur it contains are removed and then the regenerated catalyst is returned to the hydroconversion step. It is also possible to send the regenerated catalyst to a rejuvenation zone, where treatments are carried out with the aim of improving the activity of the catalyst (presulfiding, doping, etc.), and then return this regenerated catalyst to the hydroconversion process.

[0103] The catalysts used in ebullated beds are widely available commercially. They are granular catalysts whose size never reaches that of the catalysts used in spouted beds. The catalysts are usually in the form of extrudates or beads. Typically, they contain at least one hydrodehydrogenation element deposited on an amorphous support. In general, supported catalysts contain a group VIII metal and optionally a group VIB metal on an amorphous mineral support, the group VIII metal being selected from the group formed by Ni, Pd, Pt, Co, Rh and / or Ru, the group VIB metal being selected from the group formed by Mo and / or W, and the amorphous mineral support being selected from the group formed by alumina, silica, silica-alumina, magnesia, clay and mixtures of at least two of these minerals. CoMo / alumina and NiMo / alumina catalysts are the most common.

[0104] The total content of oxides of metallic elements from groups VIB and VIII is preferably between 0.1% and 40% by weight, preferentially between 5% and 35% by weight, relative to the total weight of the catalyst. The weight ratio of the metal(s) from group VIB relative to the metal(s) from group VIII, expressed as metal oxides, is preferably between 1.0 and 20, suitably between 2.0 and 10. For example, the hydroconversion reaction section of step b) of the method comprises a hydroconversion catalyst comprising 0.5% to 10% by weight of nickel, preferably 0.7% to 8% by weight of nickel, particularly preferably 0.8% to 5% by weight of nickel, expressed as nickel oxide NiO relative to the total weight of the hydroconversion catalyst, and 1.0% to 30% by weight of molybdenum, preferably 3.0% to 29% by weight of molybdenum, particularly preferably 5.0% to 25% by weight of molybdenum, expressed as molybdenum oxide MoO3, relative to the total weight of the hydroconversion catalyst, on a mineral support, preferably an alumina support.

[0105] The support for the hydroconversion catalyst is advantageously selected from alumina, silica, silica-alumina, magnesia, clay and mixtures thereof. The support may further comprise a dopant compound, in particular an oxide selected from boron oxide, in particular boron trioxide, zirconia, ceria, titanium oxide, phosphorus pentoxide and mixtures of these oxides. Preferably, the hydroconversion catalyst comprises an alumina support, preferably an alumina support doped with phosphorus and optionally with boron. If present, the concentration of phosphorus pentoxide P2O5 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. If present, the concentration of boron trioxide B2O5 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. The alumina used can be, for example, γ (gamma) or η (eta) alumina.

[0106] The hydroconversion catalyst may be, for example, in the form of extrudates or beads.

[0107] Advantageously, the hydroconversion catalyst used in step b) of the process has a specific surface area of ​​250 m 2 / g or more, preferably 300m 2 The specific surface area of ​​the hydroconversion catalyst is advantageously 800 m 2 / g or less, preferably 600m 2 / g or less, especially 400m 2 / g or less. The specific surface area of ​​the hydroconversion catalyst is measured by the BET method, i.e., the surface area is determined by nitrogen adsorption according to the standard ASTM D 3663, which is derived 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 pollutants, in particular metals, such as silicon.

[0108] Hydroconversion catalysts are distinguished from hydrotreating catalysts notably by a porosity adapted for the treatment of impurities, especially metallic impurities, and in particular by the presence of macroporosity.

[0109] According to another aspect of the invention, the hydroconversion catalyst also includes one or more organic compounds containing oxygen and / or nitrogen and / or sulfur. Such catalysts are often referred to by the term "additivated catalyst". In general, the organic compounds are selected from compounds containing one or more chemical functional groups selected from carboxylic acid, alcohol, thiol, thioether, sulfone, sulfoxide, ether, aldehyde, ketone, ester, carbonate, amine, nitrile, imide, oxime, urea and amide groups, or compounds containing a furan ring, or sugars.

[0110] (Entrained bed hydroconversion process b) According to a second variant, the hydroconversion step b) is carried out in a hydroconversion reaction section comprising at least one entrained bed reactor, also called a slurry reactor. The feedstock, hydrogen and catalyst are injected from below and flow as an ascending stream. The hydroconverted effluent and unconsumed hydrogen and catalyst are withdrawn from the top. The slurry hydroconversion technique uses a catalyst dispersed in the form of very small particles, the size of which is less than a few tens of microns (typically between 0.001 and 100 μm). The catalyst or its precursor is injected at the inlet of the reactor together with the feedstock to be converted. The catalyst passes through the reactor together with the feedstock and the converted products, which then leave the reactor entrained with the reaction products. After separation, they are found in the heaviest fraction.

[0111] The slurry catalysts are catalysts which preferably contain at least one element selected from the group formed by Mo, Fe, Ni, W, Co, V and Ru. These catalysts are generally monometallic or bimetallic, the bimetallic being for example due to the combination of non-noble group VIII elements (Co, Ni, Fe) and group VIB elements (Mo, W).

[0112] The catalysts used may be powders of heterogeneous solids (e.g. natural ores, iron sulfate, etc.), dispersed catalysts obtained from water-soluble precursors ("water-soluble dispersed catalysts"), such as phosphomolybdic acid, ammonium molybdate, or mixtures of Mo or Ni oxides with aqueous ammonia.

[0113] Preferably, the catalysts used are derived from precursors soluble in the organic phase ("oil-soluble dispersed catalysts"). The precursors are organometallic compounds, such as naphthenates of Mo, Co, Fe or Ni, or multicarbonyl compounds of these metals, such as 2-ethylhexanoate of Mo or Ni, acetylacetonate of Mo or Ni, C7-C12 fatty acid salts of Mo or W, etc. They can be used in the presence of surfactants to improve the dispersion of the metals, if the catalyst is bimetallic.

[0114] The catalyst is in the form of dispersed particles, which may or may not be colloidal depending on the nature of the catalyst. Such precursors and catalysts which may be used in the process according to the invention are widely described in the literature.

[0115] The catalyst concentration, expressed as metallic element, relative to the feedstock is generally between 1 and 10,000 ppm.

[0116] Generally, the catalyst is prepared before it is injected into the feedstock. The preparation method is adapted according to the state and nature of the precursor. In all cases, the precursor is sulfided (ex-situ or in-situ) to form the catalyst dispersed in the feedstock.

[0117] For the preferred case of "oil-soluble" catalysts, in a typical process, the precursor is mixed with a carbon-based feedstock (which may be part of the feedstock to be treated, an external feedstock, a recycle fraction, etc.), the mixture is optionally at least partially dried and then or simultaneously sulfurized by adding a sulfur compound (preferably H2S) and heated. The preparation of these catalysts is described in the prior art.

[0118] Additives may be added during the preparation of the catalyst or to the slurried catalyst before it is injected into the reactor. These additives are described in the literature.

[0119] Suitable solid additives are mineral oxides, such as alumina, silica, mixed Al / Si oxides, supported spent catalysts (for example alumina and / or silica supported) containing at least one group VIII element (for example Ni, Co) and / or at least one element of group VIB (for example Mo, W). Mention will be made, for example, of the catalysts described in patent application US 2008 / 177124. Carbon-based solids with a low hydrogen content (for example 4% hydrogen), such as coke, possibly pretreated, may be used. Mixtures of such additives may be used. Their particle size is 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, preferentially between 1% and 3% by weight, and the content of the catalyst solution is between 0 and 10% by weight, preferably between 0 and 1% by weight, relative to the weight of the injected feedstock.

[0120] If the hydroconversion step b) is carried out in an entrained bed reactor, a filtration step is necessary to recover the catalyst before passing the hydroconverted effluent to step c).

[0121] (Moving bed hydroconversion process b)) According to a third variant, the hydroconversion step b) is carried out in a hydroconversion reaction section comprising at least one moving bed reactor.

[0122] The feedstock and hydrogen can flow upwards (countercurrent method) or downwards (cocurrent method) in the moving bed reactor. The catalyst flows gradually from top to bottom by gravity and in plug flow inside the catalytic zone. It is withdrawn from below by any suitable means, for example an elevator (called a "lift"). An in-line device ensures semi-continuous renewal of the catalyst in the moving bed reactor: a part of the used catalyst is withdrawn at the bottom of the reactor, while fresh catalyst is introduced at the top of the reactor. The temperature is then controlled by a quenching process outside or inside the reactor.

[0123] Preferably, spherical catalysts with a diameter of 0.5-6 mm, preferably 1-3 mm, are used rather than extruded catalysts to obtain better fluidization. When the catalyst used is withdrawn from the bottom of the reactor, the entire catalyst bed moving in plug flow moves downwards by a height corresponding to the volume of the withdrawn catalyst. The swelling degree of the catalyst bed operating as a moving bed is advantageously less than 15%, preferably less than 10%, preferably less than 5%, more preferably less than 2%. The swelling degree is measured according to methods known to those skilled in the art.

[0124] 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 an amorphous support, highly preferably alumina, and at least one group VIII metal selected from nickel and cobalt, preferably nickel, said group VIII element being preferably used in combination with at least one group VIB metal selected from molybdenum and tungsten, preferably the group VIB metal being molybdenum. Preferably, the hydroconversion catalyst comprises nickel as group VIII element and molybdenum as group VIB element. The nickel content, expressed by the weight of nickel oxide (NiO), is advantageously between 0.5% and 10% by weight, preferably between 0.7% and 6% by weight, and the molybdenum content, expressed by the weight of molybdenum trioxide (MoO3), is advantageously between 1% and 30% by weight, preferably between 4% and 20% by weight, the percentages being expressed as percentages by weight relative to the total weight of the catalyst. The catalyst is advantageously in the form of extrudates or beads. The catalyst may advantageously contain phosphorus, preferably with a content of phosphorus pentoxide P2O5 of less than 20% by weight, preferably less than 10% by weight, percentages expressed as percentages by weight relative to the total weight of the catalyst. The catalyst may be a catalyst supplemented with an organic compound as described above.

[0125] According to yet another variant, the hydroconversion step b) may be carried out in a hydroconversion reaction section comprising a combination of at least one ebullated bed reactor, at least one entrained bed reactor and / or at least one moving bed reactor, in any order.

[0126] Preferably, step b) is carried out in a hydroconversion reaction section comprising at least one ebullated bed reactor.

[0127] (Separation step c)) According to the invention, the process comprises a separation step c), advantageously carried out in at least one washing / separation section, to which is fed at least the hydroconverted effluent obtained from step b) and the aqueous solution, to obtain at least one gaseous effluent, an aqueous effluent and a hydrocarbon effluent.

[0128] The gaseous effluent obtained on the conclusion of step c) advantageously comprises hydrogen, preferably at least 80% by volume, preferably at least 85% by volume of hydrogen. Advantageously, said gaseous effluent may be at least partially recycled to the selective hydrogenation step a) and / or to the hydroconversion step b), the recycling system optionally comprising a purification section.

[0129] The aqueous effluent obtained at the end of step c) advantageously contains ammonium salts and / or hydrochloric acid.

[0130] This separation step c) makes it possible in particular to remove ammonium chloride salts, thus limiting the risk of clogging due to precipitation of ammonium chloride salts, in particular in the transfer lines and / or in the sections of the method of the invention and / or in the lines for transfer to the steam cracker. Ammonium chloride salts are formed by reaction between chloride ions and ammonium ions, the chloride ions being released in the form of HCl by hydrogenation of chlorinated compounds, in particular during steps a) and b), and subsequently dissolved in water, and the ammonium ions being generated in the form of NH3 by hydrogenation of nitrogenous compounds, in particular during step b), and / or being introduced by injection of amines, and subsequently dissolved in water. It also makes it possible to remove the hydrochloric acid formed by reaction of the hydrogen ions with the chloride ions, and also part of the CO and CO2, if oxygen is present in the pyrolysis oil of the plastic and / or SRF.

[0131] Depending on the content of chlorinated compounds in the initial feedstock to be treated, a solvent containing amines, for example monoethanolamine, diethanolamine and / or monodiethanolamine, can 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), if present, to ensure a sufficient amount of ammonium ions to bind the chloride ions formed during the hydroconversion steps, thus making it possible to limit the formation of hydrochloric acid and therefore the corrosion downstream of the separation section.

[0132] Advantageously, separation step c) comprises the injection of an aqueous solution, preferably water, into the hydroconverted effluent obtained from step b), upstream of the washing / separation section, so as to at least partially dissolve the ammonium chloride salts and / or hydrochloric acid, thus improving the removal of chlorinated impurities and reducing the risk of clogging caused by the accumulation of ammonium chloride salts.

[0133] The temperature at which separation step c) is advantageously carried out is between 20 and 450° C., preferentially between 50 and 450° C., preferably between 100 and 440° C., preferably between 200 and 420° C. Carrying out said step in this temperature range (and therefore not cooling the hydroconverted effluent too much) is important given the risk of clogging in the lines due to 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, facilitating the recycling of hydrogen.

[0134] The washing / separation section of step c) can be carried out at least in part in common or separate washing and separation equipment, which are well known (separation drums, pumps, heat exchangers, washing columns, etc. which can be operated at various pressures and temperatures).

[0135] In one optional embodiment of the invention, the separation step c) comprises the injection of an aqueous solution into the hydroconverted effluent obtained from step b) and is followed by a washing / separation section, which advantageously comprises separate phases for obtaining 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 are subsequently separated in a knock-down drum to obtain said hydrocarbon effluent and said aqueous effluent. The partially washed gaseous effluent can be introduced in parallel into a washing column, where it flows countercurrently against an aqueous stream, preferably of the same nature as the aqueous solution injected into the hydrocarbon effluent, which makes it possible to at least partially, preferably completely, remove the hydrochloric acid contained in the partially washed gaseous effluent and thus to obtain said gaseous effluent, preferably a gaseous effluent essentially containing hydrogen, and an acidic aqueous stream. The aqueous effluent resulting from the knock-out drum may optionally be mixed with the acidic aqueous stream and may be used, optionally as a mixture with the acidic aqueous stream, in a water recycle circuit for feeding the aqueous stream to separation step c) in the aqueous solution and / or wash column upstream of the washing / separation section. The water recycle circuit may include a bleed allowing to discharge the feed of water and / or basic solution and / or dissolved salts.

[0136] The gas fraction or fractions obtained from the separation step c) may undergo one or more further purification and separation steps with the aim of recovering at least one hydrogen-rich gas and / or light hydrocarbons, in particular ethane, propane and butanes, the hydrogen-rich gas being recycled upstream of steps a) and / or b) and the light hydrocarbons being advantageously sent, separately or as a mixture, to one or more furnaces of a steam cracking step e) in order to increase the overall yield of olefins.

[0137] The hydrocarbon effluent resulting from fractionation step c) is sent partially or completely to fractionation step d). A portion of the hydrocarbon effluent obtained from step c) can be sent directly to the inlet of the steam cracking unit or alternatively recycled to steps a) and / or b).

[0138] (Fractionation step d) (optional) The process according to the invention may comprise a step of fractionating all or part, preferably all, of the hydrocarbon effluent obtained from step c) to obtain at least one gas stream and at least two liquid hydrocarbon streams, said two liquid hydrocarbon streams being at least one hydrocarbon fraction comprising compounds having a boiling point below 150°C, in particular between 80 and 150°C, and one hydrocarbon fraction comprising compounds having a boiling point above 150°C.

[0139] Step d) makes it possible in particular to remove gases dissolved in the liquid hydrocarbon effluent, such as ammonia, hydrogen sulfide and light hydrocarbons having 1 to 4 carbon atoms.

[0140] The pressure at which the fractionation step d) is carried out is advantageously below 1.0 MPa (abs), preferably between 0.1 and 1.0 MPa (abs).

[0141] According to one embodiment, step d) may be carried out in a section advantageously comprising at least one stripping tower, the stripping tower being equipped with a reflux circuit comprising a reflux drum. Said stripping tower is fed with the liquid hydrocarbon effluent resulting from step c) and with a stream of water vapor. The liquid hydrocarbon effluent resulting from step c) may optionally be heated before entering the stripping tower. The lightest compounds are therefore entrained in the top of the tower and enter a reflux circuit comprising a reflux drum, where gas / liquid separation takes place. The gas phase comprising light hydrocarbons is withdrawn as a gas stream from the reflux drum. The fraction comprising compounds with a boiling point below 150° C. is advantageously withdrawn from the reflux drum. The hydrocarbon fraction comprising compounds with a boiling point above 150° C. is advantageously withdrawn at the bottom of the stripping tower.

[0142] According to another embodiment, the fractionation step d) can use a stripping column followed by a distillation column or a distillation column only.

[0143] The fractions containing compounds with a boiling point below 150° C. and the fractions containing compounds with a boiling point above 150° C. may optionally be mixed and sent in whole or in part to a steam cracking unit, at the outlet of which olefins may be (re)formed and precipitated in the form of polymers. Preferably, only a portion of said fractions is sent to the steam cracking unit; at least a portion 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 derived from conventional petroleum-based feedstocks, such as a unit for the storage of naphtha, a unit for the storage of diesel or a unit for the storage of kerosene.

[0144] According to a preferred embodiment, the hydrocarbon fraction comprising compounds having a boiling point below 150° C. is sent in whole or in part to a steam cracking unit, and the hydrocarbon fraction comprising compounds having a boiling point above 150° C. is recycled to steps a) and / or b) and / or sent to a fuel storage unit.

[0145] In a particular embodiment, the fractionation step d) may make it possible to obtain, besides the gas stream, a naphtha fraction comprising compounds with a boiling point below 150° C., preferably between 80 and 150° C., a middle distillate fraction comprising compounds with a boiling point above 150° C. and below 360° C., and a hydrocarbon fraction comprising compounds with a boiling point above 360° C., known as the heavy hydrocarbon fraction. The naphtha fraction may be sent, in whole or in part, to a steam cracking unit and / or to a naphtha pool obtained from conventional petroleum-based feedstocks: it may be recycled; the middle distillate fraction may be sent, in whole or in part, to either a steam cracking unit or to a diesel pool obtained from conventional petroleum-based feedstocks or may be recycled; the heavy fraction may, for its part, at least in part, be sent to a steam cracking unit or may be recycled, in particular to the hydroconversion step b).

[0146] In another particular embodiment, the fractionation step d) may make it possible to obtain, in addition to the gas stream, a naphtha fraction comprising compounds with a boiling point below 150° C., preferably between 80 and 150° C., a kerosene fraction comprising compounds with a boiling point above 150° C. and below 280° C., a diesel fraction comprising compounds with a boiling point above 280° C. and below 360° C. and a hydrocarbon fraction comprising compounds with a boiling point above 360° C., known as the heavy hydrocarbon fraction. The naphtha, kerosene and / or diesel fractions may be sent, in whole or in part, to a steam cracking unit or to the naphtha, kerosene or diesel pools, respectively, obtained from conventional petroleum-based feedstocks, or may be recycled; the heavy fraction may, for its part, at least in part, be sent to a steam cracking unit or recycled, in particular to the hydroconversion step b).

[0147] In another particular embodiment, the hydrocarbon fraction resulting from step d) containing compounds with a boiling point less than or equal to 150° C. is fractionated to give a heavy naphtha fraction containing compounds with a boiling point between 80 and 150° C. and a light naphtha fraction containing compounds with a boiling point less than 80° C., at least a portion of said heavy naphtha fraction being sent to an aromatics complex comprising at least one step of naphtha reforming with the purpose of obtaining aromatics. According to this embodiment, at least a portion of the light naphtha fraction is sent to the steam cracking step e) described below.

[0148] The gas fraction or fractions resulting from the fractionation step d) may be subjected to one or more further purification steps and one or more separation steps with the aim of at least recovering the light hydrocarbons, in particular ethane, propane and butanes, which may advantageously be sent, separately or as a mixture, to one or more furnaces of a steam cracking step e) in order to increase the overall yield of olefins.

[0149] (Steam cracking step e) (optional) The hydrocarbon effluent resulting from the separation step c) or at least one of the two liquid hydrocarbon streams resulting from step d) may be sent completely or partly to a steam cracking step e).

[0150] Advantageously, the ethane-, propane- and butane-containing gas fraction(s) resulting from the separation step c) and / or the fractionation step d) may also be sent, completely or partly, to the steam cracking step e).

[0151] Said steam cracking step e) is advantageously carried out in at least one pyrolysis furnace, the temperature being between 700 and 900°C, preferably between 750 and 850°C, the pressure being between 0.05 and 0.3 MPa (relative). The residence time of the hydrocarbon compounds is generally less than or equal to 1.0 second (denoted s), preferably between 0.1 and 0.5 s. Steam is advantageously introduced upstream of the optional steam cracking step e), after separation (or fractionation). The amount of water introduced, advantageously in the form of steam, at the inlet of step e) is advantageously between 0.3 and 3.0 kg of water per kg of weight of hydrocarbon compounds. Optional step e) is preferably carried out in several pyrolysis furnaces in parallel, with the operating conditions adapted to the various streams feeding step e), in particular those obtained from step d), and also to manage the decoking times of the tubes. The furnace comprises one or several tubes arranged in parallel. A furnace may also represent a group of furnaces operating in parallel, for example a furnace may be dedicated to the cracking of a fraction containing compounds with a boiling point below 150° C.

[0152] The effluents from the various steam cracking furnaces are generally recombined before separation for the purpose of constituting the effluent. It is understood that the steam cracking step e) includes not only the steam cracking furnaces but also sub-steps related to steam cracking that are well known to those skilled in the art. These sub-steps may include, inter alia, heat exchangers, columns and catalytic reactors and recycle to the furnaces. The columns generally make it possible to fractionate the effluent for the purpose of recovering at least one light fraction comprising hydrogen and compounds having 2 to 5 carbon atoms, a fraction comprising pyrolysis gasoline and optionally a fraction comprising pyrolysis oil. The columns make it possible to separate the various components of the fractionated light fractions in order to recover at least a fraction rich in ethylene (C2 fraction) and a fraction rich in propylene (C3 fraction) and possibly a fraction rich in butenes (C4 fraction). The catalytic reactors make it possible in particular to carry out hydrogenation of the C2, C3 and indeed even C4 fractions and pyrolysis gasoline. Saturated compounds, especially those having from 2 to 4 carbon atoms, are advantageously recycled to the steam cracking furnace to increase the overall yield of olefins.

[0153] This steam cracking step e) makes it possible to obtain at least one effluent containing olefins containing 2, 3 and / or 4 carbon atoms (i.e. C2, C3 and / or C4 olefins) in a satisfactory content, in particular of 30% by weight or more, in particular 40% by weight or more, or even 50% by weight or more of the total olefins containing 2, 3 and 4 carbon atoms relative to the weight of the steam cracking effluent under consideration. Said C2, C3 and C4 olefins can then advantageously be used as polyolefin monomers.

[0154] (Variations of the method) According to a preferred embodiment of the present invention, the method for processing a feedstock comprising pyrolysis oil comprises, and preferably consists of, the following sequence of steps, preferably performed in the given order: b) hydroconversion, c) separation.

[0155] According to another preferred embodiment of the present invention, the method for processing a feedstock comprising pyrolysis oil comprises, and preferably consists of, the following sequence of steps, preferably performed in the given order: b) hydroconversion, c) separation, d) fractionation.

[0156] According to another preferred embodiment of the present invention, the method for processing a feedstock comprising pyrolysis oil comprises, and preferably consists of, the following sequence of steps, preferably performed in the given order: a) selective hydrogenation; b) hydroconversion; c) separation; d) fractionation.

[0157] All embodiments can further comprise, and preferably consist of, a pretreatment step a0).

[0158] All embodiments may further comprise, and preferably consist of, a steam cracking step f).

[0159] The process according to the invention makes it possible to obtain a pyrolysis oil which can be directly upgraded by incorporation into a fuel pool and / or directly suitable for processing in a steam cracking unit without the need to carry out other hydrogen-based processes apart from hydroconversion, although the process can also include hydrotreating and optional hydrocracking steps, which may be carried out at various points during the process according to the invention.

[0160] (Hydrotreatment step c) (optional) According to the invention, the processing method may comprise a hydrotreatment step which may be carried out before or after the separation step c) or else after the fractionation step d), in particular the treatment of the hydrocarbon fraction comprising compounds with a boiling point above 150° C.

[0161] Advantageously, the hydrotreating step uses hydrotreating reactions well known to those skilled in the art, more particularly hydrotreating reactions such as hydrogenation, hydrodesulfurization and hydrodenitrification of aromatic compounds, followed by hydrogenation and also hydrodemetallization of the remaining halogenated compounds and olefins.

[0162] The hydrotreating step is carried out in a hydrotreating reaction section, which comprises at least one fixed bed reactor having n catalyst beds, n being an integer equal to or greater than 1, each containing at least one hydrotreating catalyst.

[0163] If a hydrotreating step is carried out prior to separation step c), said hydrotreating reaction section is fed with at least a portion of said hydroconverted effluent from step b) and with a gas stream comprising hydrogen to obtain a hydrotreated effluent.

[0164] In case separation step c) is followed by a hydrotreating step, said hydrotreating reaction section is fed with at least a portion of said hydrocarbon effluent obtained from step c) and with a gas stream comprising hydrogen to obtain a hydrotreated effluent.

[0165] If fractionation step d) is followed by a hydrotreating step, said hydrotreating reaction section is fed with at least a portion of said hydrocarbon fraction comprising compounds having a boiling point above 150° C. resulting from step d) and with a gas stream comprising hydrogen to obtain a hydrotreated effluent.

[0166] The average hydrotreating temperature when the hydrotreating reaction section is advantageously operated is 250 to 430°C, preferably 300 to 400°C, the hydrogen partial pressure is 1.0 to 20.0 MPa (abs), preferably 3.0 to 15.0 MPa (abs), and the hourly space velocity (HSV) is 0.1 to 10.0 h -1 , preferably 0.1 to 5.0 h -1 , preferentially 0.2~2.0h -1 , preferably 0.2 to 1.0 h -1The hydrogen coverage in the hydrotreating step is advantageously determined by the volume (m ) of the feedstock fed to the hydrotreating step. 3 ) Hydrogen 50~2000Nm 3 , preferably the volume of the feedstock (m 3 ) Hydrogen 100-1000Nm 3 , preferably the volume of the feedstock (m 3 ) Hydrogen 120~800Nm 3 It is.

[0167] The definitions of average temperature (WABT), HSV and hydrogen coverage correspond to those given above in the selective hydrogenation step a).

[0168] The hydrogen-containing gas stream feeding the reaction section of the hydrotreating step may consist of a hydrogen feed and / or recycled hydrogen, advantageously recycled hydrogen obtained from step c) and / or step d).

[0169] Advantageously, said hydrotreating step is carried out in a hydrotreating reaction section, said section comprising at least one, preferably between 1 and 5, fixed bed reactors, said reactors having n catalyst beds, n being an integer greater than or equal to 1, preferably between 1 and 10, suitably between 2 and 5, said bed or beds each comprising at least one and preferably not more than 10 hydrotreating catalysts. When a reactor comprises several catalyst beds, i.e. at least 2, preferably between 2 and 10, suitably between 2 and 5, said catalyst beds are preferably arranged in series in said reactor.

[0170] If the hydrotreating step is carried out in a hydrotreating reaction section comprising several reactors, preferably two reactors, these reactors can be operated in series and / or in parallel and / or in variable sequence (or PRS) mode and / or in swing mode. The various optional operating modes, PRS mode (or lead and lag) and swing mode, are well known to the person skilled in the art and are advantageously as defined above.

[0171] In another embodiment of the invention, the hydrotreating reaction section comprises a single fixed bed reactor containing n catalyst beds, n being an integer equal to or greater than 1, preferably between 1 and 10, suitably between 2 and 5.

[0172] Advantageously, the hydrotreating catalyst used in the hydrotreating step can be selected from known hydrodemetallization, hydrotreating or silicon capture catalysts, and combinations thereof, which are particularly used for the treatment of petroleum-based fractions. Known hydrodemetallization catalysts are, for example, those described in patents EP 0 113 297, EP 0 113 284, US 5 221 656, US 5 827 421, US 7 119 045, US 5 622 616 and US 5 089 463. Known hydrotreating catalysts are, for example, those described in patents EP 0 113 297, EP 0 113 284, US 6 589 908, US 4 818 743 or US 6 332 976. Known silicon capture catalysts are, for example, those described in patent applications CN 102051202 and US 2007 / 080099.

[0173] In particular, said hydrotreating catalyst comprises a support, preferably an inorganic support, and at least one metallic element having hydrodehydrogenation function. Said metallic element having hydrodehydrogenation function advantageously comprises at least one element from group VIII and / or at least one element from group VIB, the element from group VIII being preferably selected from the group consisting of nickel and cobalt, and the element from group VIB being preferably selected from the group consisting of molybdenum and tungsten. The total content of oxides of metallic elements from groups VIB and VIII is preferably between 0.1% and 40% by weight, preferentially between 5% and 35% by weight, relative to the total weight of the catalyst. The weight ratio of one or more metals from group VIB relative to one or more metals from group VIII, expressed as metal oxides, is preferably between 1.0 and 20, advantageously between 2.0 and 10. For example, the hydrotreating reaction section of step c) of the method comprises a hydrotreating catalyst comprising, on a mineral support, 0.5% to 10% by weight of nickel, expressed as nickel oxide NiO relative to the total weight of the hydrotreating catalyst, preferably 1% to 8% by weight of nickel, and 1.0% to 30% by weight, preferably 3.0% to 29% by weight of a total weight of molybdenum and / or tungsten, expressed as molybdenum oxide MoO3 or tungsten oxide WO3 relative to the total weight of the hydrotreating catalyst.

[0174] The support of the hydrotreating catalyst is advantageously selected from alumina, silica, silica-alumina, magnesia, clay and mixtures thereof. The support may advantageously contain a dopant compound, in particular an oxide selected from boron oxide, in particular boron trioxide, zirconia, ceria, titanium oxide, phosphorus pentoxide and mixtures of these oxides. Preferably, the hydrotreating catalyst comprises an alumina support, preferably an alumina support doped with phosphorus and optionally boron. If phosphorus pentoxide 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. If 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% by weight, relative to the total weight of the alumina. The alumina used can be, for example, γ (gamma) or η (eta) alumina.

[0175] The hydrotreating catalyst is, for example, in the form of extrudates.

[0176] Advantageously, the specific surface area of ​​the hydrotreating catalyst used in the hydrotreating step is less than 250 m 2 / g or more, preferably 300m 2 The specific surface area of ​​the hydrotreating catalyst is advantageously greater than or equal to 800 m 2 / g or less, preferably 600m 2 / g or less, especially 400m 2 / g or less. The specific surface area of ​​the hydrotreating catalyst is measured by the BET method, i.e., it is determined by nitrogen adsorption according to the standard ASTM D 3663, which is derived 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 pollutants, in particular metals, such as silicon.

[0177] According to another aspect of the invention, the hydrotreating catalyst as described above further comprises one or more organic compounds containing oxygen and / or nitrogen and / or sulfur. Such catalysts are often referred to by the term "additivated catalyst". In general, the organic compounds are selected from compounds containing one or more chemical functional groups selected from carboxylic acid, alcohol, thiol, thioether, sulfone, sulfoxide, ether, aldehyde, ketone, ester, carbonate, amine, nitrile, imide, oxime, urea and amide groups, or from compounds containing a furan ring, or from sugars.

[0178] If a hydrotreating step is carried out before the separation step c) and after the hydroconversion step b), according to a first variant, said hydrotreating step is carried out without an intermediate separation step between the conversion step b) and the hydrotreating step. The effluent from the hydroconversion step b) does not undergo any step of intermediate separation of the gas stream between the hydroconversion step b) and the hydrotreating step. This configuration can be described as an integrated scheme. In the present invention, the expression "without any intermediate separation step" is understood to mean the fact that at least a part of the effluent from the hydroconversion step b) is introduced into a section that allows the implementation of a hydrotreating step without changing its chemical composition and without significant pressure losses. The term "separation" is understood to mean one or more separation drums and / or one or more stripping or distillation columns, which equipment can be operated at different temperatures or pressures. The expression "significant pressure loss" is understood to mean the pressure loss caused by the expansion turbine or valves, which could be estimated at a pressure loss of more than 10% of the total pressure. Those skilled in the art commonly use these pressure losses or expansions during the separation process.

[0179] In one embodiment, the entire effluent from the hydroconversion step b) is introduced into a section making it possible to carry out a hydrotreatment step.

[0180] In another embodiment, only a part of the effluent from the hydroconversion step b) is introduced into the section allowing the implementation of a hydrotreating step. However, this embodiment does not contradict the fact that the method does not contain any intermediate separation steps. This embodiment may consist of splitting the effluent from the hydroconversion step b) into two streams having the same composition, one of which goes to a hydrotreating step located downstream. This embodiment may therefore be likened to a partial bypass of the hydrotreating section, but with a part of the effluent of the hydroconversion section b) going to the hydrotreating section, without separation, modification of chemical composition and without significant pressure loss. Another variant of this bypass embodiment may consist of splitting the effluent from the hydroconversion step b) into several streams having the same composition, and sending one or more of these streams to the inlet of the first hydrotreating reactor and one or more others of these streams to one or more downstream hydrotreating reactors.

[0181] If a hydrotreating step is carried out before the separation step c) and after the hydroconversion step b), according to a second variant, said hydrotreating step is carried out with an intermediate separation step between the hydroconversion step b) and the hydrotreating step. Advantageously, said intermediate separation step comprises a step of fractionating all or part of the hydrocarbon effluent obtained from step c) to obtain at least one gas stream and a hydrocarbon fraction comprising compounds with a boiling point below 360° C. and a hydrocarbon fraction comprising compounds with a boiling point above 360° C. The said hydrocarbon fraction comprising compounds with a boiling point below 360° C. is then introduced into a hydrotreating step, while the fraction comprising compounds with a boiling point above 360° C. is preferably recycled to the hydroconversion step b).

[0182] If a hydrotreating step is carried out before the separation step c) and after the hydroconversion step b), in order to avoid carrying catalyst fines and / or catalyst from the hydroconversion step b) into said hydrotreating reaction section, recovery means may be arranged upstream or at the inlet of said hydrotreating reaction section, for example using one or more filters or even reactor internals, for example of the filter plate type. Examples of filter plates are described in patent FR 3 051 375.

[0183] (Hydrocracking step (optional)) According to the invention, the processing method may comprise a hydrocracking step, which is carried out either after the hydrotreating step or after the fractionation step d), in particular the treatment of a hydrocarbon fraction comprising compounds with a boiling point above 150° C.

[0184] Advantageously, the hydrocracking step makes it possible to carry out hydrocracking reactions well known to those skilled in the art and, more particularly, to convert the heavy compounds contained in the hydrotreated effluent or separated during the fractionation step d), such as compounds with a boiling point above 150° C., into compounds with a boiling point below 150° C. Other reactions can be pursued, such as hydrogenation of olefins or aromatics, hydrodemetallization, hydrodesulfurization, hydrodenitrogenation etc.

[0185] Compounds with boiling points above 150° C. have a high BMCI and contain more naphthenic, naphthenic-aromatic and aromatic compounds relative to the lighter compounds, thus leading to a higher C / H ratio. This high ratio is the cause of coking in the steam cracker, hence the need for a dedicated steam cracking furnace for this fraction. If it is desired to minimize the yield of these heavy compounds (diesel fraction) and maximize the yield of light compounds (naphtha fraction), these compounds can be at least partially converted to light compounds by hydrocracking, the fraction generally preferred for the steam cracking unit.

[0186] The hydrocracking step is carried out in a hydrocracking reaction section using at least one fixed bed reactor containing n catalyst beds, n being an integer equal to or greater than 1, each containing at least one hydrocracking catalyst.

[0187] If a hydrocracking step is carried out after the hydrotreating step, said hydrocracking reaction section is fed with at least a portion of said hydrotreated effluent and with a gas stream comprising hydrogen to obtain a hydrocracked effluent, said hydrotreating step being able to be carried out before or after separation step c) or else after fractionation step d), as described above.

[0188] If fractionation step d) is followed by a hydrocracking step, said hydrocracking reaction section is fed with at least a portion of said hydrocarbon fraction comprising compounds having a boiling point above 150° C. resulting from step d) and with a gas stream comprising hydrogen to obtain a hydrocracked effluent.

[0189] The average temperature when the hydrocracking reaction section is advantageously used is 250 to 450°C, preferably 320 to 440°C, the hydrogen partial pressure is 1.5 to 20.0 MPa (abs), preferably 2 to 18.0 MPa (abs), and the hourly space velocity (HSV) is 0.1 to 10.0 h -1 , preferably 0.1 to 5.0 h -1 , preferentially 0.2~4h -1 The hydrogen coverage in the hydrocracking step is advantageously determined by the volume (m ) of fresh feedstock fed to step a) or b). 3 ) Hydrogen 80~2000Sm 3 , preferably the volume (m ) of fresh feedstock fed to step a) or b). 3 ) Hydrogen 200~1800Sm 3 The definitions of the average temperature (WABT), HSV and hydrogen coverage correspond to those given in the selective hydrogenation step a) above.

[0190] Advantageously, said hydrocracking reaction section is carried out at a pressure similar to that used in the reaction section of the hydrotreating step.

[0191] Advantageously, said hydrocracking step is carried out in a hydrocracking reaction section comprising at least one, preferably between 1 and 5, fixed bed reactors having n catalyst beds, n being an integer greater than or equal to 1, preferably between 1 and 10, suitably between 2 and 5, said bed or beds each comprising at least one and preferably not more than 10 hydrocracking catalysts. When a reactor comprises several catalyst beds, i.e. at least 2, preferably between 2 and 10, suitably between 2 and 5, said catalyst beds are preferably arranged in series in said reactor.

[0192] The hydrotreating and hydrocracking steps may advantageously be carried out in one and the same reactor or in different reactors, in which case the reactor comprises several catalyst beds, the first of which comprises one or more hydrotreating catalysts and the subsequent catalyst beds comprising one or more hydrocracking catalysts.

[0193] The hydrocracking step can be carried out in one or two steps.

[0194] When it is carried out in two steps, a fractionation of the effluent obtained from the first hydrocracking step is carried out, making it possible to obtain a hydrocarbon fraction comprising compounds with a boiling point above 150° C., which fraction is introduced into a second hydrocracking step, which step comprises a dedicated second hydrocracking reaction section different from the first hydrocracking reaction section. This configuration is particularly suitable when it is desired to produce only a naphtha fraction.

[0195] The second hydrocracking step is carried out in a hydrocracking reaction section using at least one fixed bed containing n catalyst beds, n being an integer equal to or greater than 1, each containing at least one hydrocracking catalyst, the hydrocracking reaction section being fed at least with the hydrocarbon fraction containing compounds having a boiling point above 150° C. obtained from the first hydrocracking step and a gas stream containing hydrogen, the average temperature used in the hydrocracking reaction section being 250-450° C., the partial pressure of hydrogen being 1.5-20.0 MPa (abs), and the hourly space velocity being 0.1-10.0 h -1 to obtain a hydrocracked effluent, which may be sent to a separation step c). Suitable operating conditions and catalysts used in the second hydrocracking step are those described for the first hydrocracking step. The operating conditions and catalysts used in the two hydrocracking steps may be the same or different.

[0196] The second hydrocracking step is preferably carried out in a hydrocracking reaction section comprising at least one, preferably from 1 to 5, fixed bed reactors, the fixed bed reactor(s) having n catalyst beds, n being an integer equal to or greater than 1, preferably from 1 to 10, suitably from 2 to 5, and the one or more beds each comprising at least one, and preferably not more than 10, hydrocracking catalysts.

[0197] These operating conditions used in one or more hydrocracking steps generally make it possible to obtain a conversion per pass of more than 15% by weight, even more preferably between 20% and 95% by weight, to a product having a minimum of 80% by weight of compounds boiling below 150° C. If the process is carried out in two hydrocracking steps, the conversion per pass in the second step is kept moderate so as to maximize the selectivity for compounds of the naphtha fraction (boiling below 150° C., in particular between 80° C. and 150° C.). The conversion per pass is limited by the use of a high recycle rate over the loop of the second hydrocracking step. This rate is defined as the ratio of the feed flow rate of the second hydrocracking step to the flow rate of the feedstock of step a); preferentially, this ratio is between 0.2 and 4, preferably between 0.5 and 2.5.

[0198] The hydrocracking step or steps therefore do not necessarily make it possible to convert all compounds with a boiling point above 150° C. into compounds with a boiling point below 150° C. After fractionation step d), a more or less significant proportion of compounds with a boiling point above 150° C. may therefore remain. To increase the conversion, at least a part of this unconverted fraction can be recycled to the first hydrocracking step or else sent to a second hydrocracking step, as described below. Another part can be taken off. Depending on the operating conditions of the process, said take-off can be between 0% and 10% by weight, preferably between 0.5% and 5% by weight, of the fraction containing compounds with a boiling point above 150° C., relative to the incoming feedstock.

[0199] According to the present invention, the hydrocracking step or steps proceed in the presence of at least one hydrocracking catalyst.

[0200] The hydrocracking catalyst or catalysts used in the hydrocracking step or steps are conventional hydrocracking catalysts known to those skilled in the art and are of the bifunctional type, combining an acid function with a hydrodehydrogenation function and optionally at least one binding matrix. The acid function is a high surface area (typically 150-800 m2) that exhibits surface acidity. 2 The hydrodehydrogenation function is contributed by at least one metal from group VIB and / or at least one metal from group VIII of the periodic table, such as halogenated (especially chlorinated or fluorinated) aluminas, combinations of oxides of aluminium and boron, amorphous silica-alumina and zeolites.

[0201] Preferably, the hydrodehydrogenation functional group of the hydrocracking catalyst or catalysts comprises at least one metal from group VIII selected from iron, cobalt, nickel, ruthenium, rhodium, palladium and platinum, preferably from cobalt and nickel. Preferably, said catalyst or catalysts also comprise at least one metal from group VIB selected from chromium, molybdenum and tungsten, alone or in a mixture, preferably from molybdenum and tungsten. Hydrodehydrogenation functional groups of the NiMo, NiMoW or NiW type are preferred.

[0202] Preferably, the content of metal from group VIII in the hydrocracking catalyst or catalysts is advantageously between 0.5% and 15% by weight, preferably between 1% and 10% by weight, the percentages being expressed as percentages by weight of the oxide 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.

[0203] Preferably, the content of metal from group VIB in the hydrocracking catalyst or catalysts is advantageously between 5% and 35% by weight, preferably between 10% and 30% by weight, the percentages being expressed as percentages by weight of the oxide 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.

[0204] The one or more hydrocracking catalysts may optionally also comprise at least one promoter element deposited on the catalyst, the promoter element being selected from the group formed by phosphorus, boron and silicon, and the hydrocracking catalyst may optionally comprise at least one element from group VIIa (preferably chlorine, fluorine), and optionally at least one element from group VIIB (preferably manganese) and optionally at least one element from group VB (preferably niobium).

[0205] Preferably, the hydrocracking catalyst or catalysts comprise at least one amorphous or poorly crystalline porous inorganic matrix of the oxide type and are chosen from alumina, silica, silica-alumina, aluminates, alumina-boron oxide, magnesia, silica-magnesia, zirconia, titanium oxide or clays, either alone or in mixtures, and preferably from alumina or silica-alumina, either alone or in mixtures.

[0206] Preferably, the silica-alumina contains more than 50% by weight of alumina, preferably more than 60% by weight of alumina.

[0207] Preferably, the hydrocracking catalyst or catalysts optionally also comprise a zeolite, the zeolite being selected from Y zeolites, preferably from USY zeolites, alone or in combination with other zeolites, alone or as mixtures, from Beta, ZSM-12, IZM-2, ZSM-22, ZSM-23, SAPO-11, ZSM-48 or ZBM-30 zeolites. Preferably, the zeolite is USY zeolite alone.

[0208] In the case where the catalyst comprises a zeolite, the content of zeolite in the hydrocracking catalyst or catalysts is advantageously between 0.1% and 80% by weight, preferably between 3% and 70% by weight, the percentages being expressed as the percentage of zeolite relative to the total weight of the catalyst.

[0209] Suitable catalysts comprise, preferably consist of, at least one metal from Group VIB and optionally at least one non-noble metal from Group VIII, at least one promoter element, preferably phosphorus, at least one Y zeolite and at least one alumina binder.

[0210] An even more preferred catalyst comprises, and preferably consists of, nickel, molybdenum, phosphorus, USY zeolite, optionally also beta zeolite, and alumina.

[0211] Other suitable catalysts include, and preferably consist of, nickel, tungsten, alumina and silica-alumina.

[0212] Other suitable catalysts include, and preferably consist of, nickel, tungsten, USY zeolite, alumina and silica-alumina.

[0213] The hydrocracking catalyst is, for example, in the form of extrudates.

[0214] In one variant, the hydrocracking catalyst used in the second hydrocracking step comprises a hydrodehydrogenation functional group which comprises at least one noble metal from group VIII, chosen alone or in a mixture from palladium and platinum, the content of noble metal from group VIII being advantageously between 0.01% and 5% by weight, preferably between 0.05% and 3% by weight, the percentages being expressed as percentages by weight of oxide (PtO or PdO) relative to the total weight of the catalyst.

[0215] According to another aspect of the invention, the hydrogenolysis catalyst also comprises one or more organic compounds containing oxygen and / or nitrogen and / or sulfur. Such catalysts are often referred to by the term "additivated catalyst". In general, the organic compounds are selected from compounds containing one or more chemical functional groups selected from carboxylic acid, alcohol, thiol, thioether, sulfone, sulfoxide, ether, aldehyde, ketone, ester, carbonate, amine, nitrile, imide, oxime, urea and amide groups, or from compounds containing a furan ring, or from sugars.

[0216] The preparation of catalysts for selective hydrogenation (step a)), hydroconversion (step b), hydrotreating and hydrocracking is known and generally comprises a step of impregnation on the support of a group VIII metal and, if present, a group VIB metal, and optionally phosphorus and / or boron, followed by drying and then optionally calcination. In the case of additive type catalysts, the preparation is generally carried out by simple drying without calcination after the introduction of the organic compound. The term "calcination" is understood here to mean a heat treatment at a temperature of 200° C. or higher under air or a gas containing oxygen. Before their use in the steps of the method, the catalysts are generally subjected to sulfurization to form the active body. The catalysts of step a) can also be catalysts used in their reduced form, thus comprising a reduction step during their preparation.

[0217] Depending on the content of sulfur compounds in the initial feedstock to be treated, a stream containing a sulfiding agent can be injected upstream of the selective hydrogenation step a) and / or the hydroconversion step b) and / or the hydrotreating step and / or the hydrocracking step, if present, and preferably upstream of the selective hydrogenation step a) and / or the hydroconversion step b), if present, to ensure a sufficient amount of sulfur to form or maintain the active species (sulfided form) of the catalyst. This activation or sulfiding step is carried out by methods well known to those skilled in the art, advantageously under a sulfo-reducing atmosphere in the presence of hydrogen and hydrogen sulfide. The sulfiding agent can be H2S gas, elemental sulfur, CS2, thiols, sulfides and / or polysulfides, hydrocarbon fractions with a boiling point below 400° C. containing sulfur compounds or any other sulfur-containing compound used for the activation of the hydrocarbon feedstock with the purpose of sulfiding the catalyst. The sulfur-containing compound is advantageously selected from alkyl disulfides, such as dimethyl disulfide (DMDS), alkyl sulfides, such as dimethyl sulfide, thiols, such as n-butylthiol (or 1-butanethiol), and polysulfide compounds of the tert-nonyl polysulfide type. The catalyst can also be sulfurized by the sulfur contained in the feedstock to be desulfurized. Preferably, the catalyst is sulfurized in situ in the presence of a sulfurizing agent and a hydrocarbon feedstock. Highly preferably, the catalyst is sulfurized in situ in the presence of a feedstock doped with dimethyl disulfide.

[0218] The hydrogen-containing gas stream is fed to the reaction section of the selective hydrogenation step (step a)), the hydroconversion step (step b)) and, if present, the hydrotreating and / or hydrocracking steps, and may consist of the hydrogen feed and / or recycled hydrogen, advantageously from step c) and / or step d). Preferably, an additional hydrogen-containing gas stream is advantageously introduced at the inlet of each reactor, in particular of reactors operating in series, and / or at the inlet of each catalyst bed starting from the second catalyst bed of the reaction section. These additional gas streams are also called cooling streams. They make it possible to control the temperature in the reactors in which the reactions taking place are generally highly exothermic.

[0219] FIG. 1 represents a diagram of a particular embodiment of the method of the present invention, which includes: - optional step a): selective hydrogenation of a feedstock (1) comprising pyrolysis oils of plastics and / or SRF, carried out in the presence of a hydrogen-rich gas (2) and of an amine provided by optional stream (3) and a sulfiding agent provided by optional stream (4), in at least one fixed bed reactor, said reactor comprising at least one selective hydrogenation catalyst, to obtain an effluent (5); - step b); hydroconversion of the effluent (5) obtained from step a), carried out in the presence of hydrogen (6) in at least one ebullated bed, entrained bed and / or moving bed reactor, said reactor comprising at least one hydroconversion catalyst, to obtain a hydroconverted effluent (7); - step c); separation of the effluent (7), carried out in the presence of an aqueous wash solution (8) and making it possible to obtain at least one gas fraction (9) containing hydrogen, an aqueous fraction (10) containing dissolved salts and a hydrocarbon liquid fraction (11); - step d): fractionation of the hydrocarbon liquid fraction (11); making it possible to obtain at least one gas fraction (12), a hydrocarbon fraction (13) comprising compounds with a boiling point below 150° C. and a hydrocarbon fraction (14) comprising compounds with a boiling point above 150° C.

[0220] At the end of step d), at least a portion of the hydrocarbon liquid effluents (13) and / or (14) is sent to a steam cracking process (not shown).

[0221] Optionally, a portion of said hydrocarbon fraction (13) comprising compounds with a boiling point below 150° C. constitutes a recycle stream which is fed to steps a) and / or b), respectively (not shown).

[0222] Optionally, a portion of said hydrocarbon fraction (14) comprising compounds with a boiling point above 150° C. constitutes a recycle stream, which is fed to step b) (not shown).

[0223] 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 carry out their injection at the inlet of each of the reaction steps, in particular at the inlet of the hydroconversion step b) and optionally at the inlet of the hydrotreating and / or hydrocracking steps, if these are present. Depending on the characteristics of the feedstock, it is also possible not to inject the amine stream (3) and / or the sulfurizing agent (4).

[0224] Only the main steps, together with the main flows, are shown in Figure 1 to allow a better understanding of the invention. It is clearly understood that all the equipment required for the operation (drums, pumps, exchangers, ovens / furnaces, columns, etc.) is present, even if not shown. It is also understood that a hydrogen-rich gas stream (feed or recycle) can be injected at the inlet of each reactor or catalyst bed or between two reactors or two catalyst beds, as described above. Means for hydrogen purification and recycling well known to those skilled in the art can also be used.

[0225] (Recycling of hydrocarbon fractions containing compounds with boiling points above 150°C) At least a portion of the hydrocarbon fraction comprising compounds with a boiling point above 150° C. obtained from fractionation step d) can be recovered to constitute a recycle stream which is sent upstream of at least one of the reaction steps of the process according to the invention, in particular the selective hydrogenation step a) and / or the hydroconversion step b), and / or the hydrotreating step and / or at least one hydrocracking step, if present, or directly to such a reaction step. In some cases, a portion of the recycle stream can optionally be sent to step a0).

[0226] The recycle stream may be fed to said reaction step in a single injection or may be split into several portions and fed to the reaction step in multiple injections, i.e. to different catalyst beds if the reactor is a fixed bed reactor.

[0227] Advantageously, the amount of the recycle stream of the fraction containing compounds with a boiling point above 150° C. is adjusted so that the weight ratio between the recycle stream and the feedstock containing pyrolysis oil that is fed to the overall process, i.e. the feedstock to be treated, is less than or equal to 10, preferably less than or equal to 5, and preferentially greater than or equal to 0.001, preferably greater than or equal to 0.01, preferably greater than or equal to 0.1. Highly preferably, the amount of the recycle stream is adjusted so that the weight ratio between the recycle stream and the feedstock containing pyrolysis oil is between 0.2 and 5.

[0228] According to one preferred variant, at least a portion of the fraction comprising compounds with a boiling point above 150° C. obtained from fractionation step d) is sent to a hydroconversion step b).

[0229] According to another preferred variant, at least a portion of the fraction comprising compounds with a boiling point above 150° C. obtained from fractionation step d) is sent to a hydrocracking step, if present.

[0230] According to another preferred variant, at least a portion of the fraction comprising compounds with a boiling point above 150° C. obtained from fractionation step d) is sent to a second hydrocracking step, if present.

[0231] Recycling of part of the cut comprising compounds with a boiling point above 150° C. to or upstream of at least one of the reaction steps of the process according to the invention, in particular the hydroconversion step b) and / or the hydrocracking step, if present, advantageously makes it possible to increase the yield of naphtha cuts with a boiling point below 150° C. Recycling also makes it possible to dilute impurities and to control the temperature during one or more reaction steps in which the reactions involved may be highly exothermic.

[0232] A purge may be installed on the recycle of the fraction containing compounds with a boiling point above 150° C. Depending on the operating conditions of the process, said purge may be 0-10% by weight, preferably 0.5% to 5% by weight, of the fraction containing compounds with a boiling point above 150° C. relative to the incoming feedstock.

[0233] (Recycling of the hydrocarbon effluent obtained from step c) and / or the hydrocarbon fraction obtained from step d) having a boiling point of ≦150° C.) A portion of the hydrocarbon effluent obtained from the separation step c) or a portion of the cut having a boiling point below 150° C. obtained from the fractionation step d) may 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 the selective hydrogenation step a) and / or the hydrotreating step, if such a step is present. Optionally, a portion of the recycle stream may be sent to the optional pretreatment step a0).

[0234] Advantageously, the amount of the recycle stream, i.e. the recycled proportion of the product obtained, is adjusted so that the weight ratio of the recycle stream to the feedstock comprising pyrolysis oil feeding the entire process, i.e. the feedstock to be treated, is less than or equal to 10, preferably less than or equal to 5, and preferentially greater than or equal to 0.001, preferably greater than or equal to 0.01, suitably greater than or equal to 0.1. Highly preferably, the amount of the recycle stream is adjusted so that the weight ratio between the recycle stream and the feedstock comprising pyrolysis oil is between 0.2 and 5.

[0235] Advantageously, for the initial stage of the process, a hydrocarbon cut external to the process can be used as a recycle stream. The person skilled in the art will then know how to select said hydrocarbon cut.

[0236] Recycling of a portion of the product obtained into or upstream of at least one of the reaction steps of the process according to the invention advantageously makes it possible, on the one hand, to dilute impurities and, on the other hand, to control the temperature during one or more reaction steps in which the reactions involved may be highly exothermic.

[0237] The hydrocarbon effluent or said hydrocarbon stream(s) thus obtained by the treatment of the pyrolysis oil of plastics and / or SRF according to the method of the invention exhibits a composition that is capable of meeting the feedstock specifications at the inlet of the 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, preferentially less than or equal to 1.0 ppm by weight and suitably less than or equal to 0.5 ppm by weight, whereby: The content of silicon (Si) element is 5.0 ppm by weight or less, preferably 0.6 ppm by weight or less, and The iron (Fe) element content is 200 ppb by weight or less. 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, 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 content of elemental chlorine 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 diolefins) is less than or equal to 5.0% by weight, preferably less than or equal to 2.0% by weight, and advantageously less than or equal to 0.1% by weight;

[0238] The content is given as a relative weight concentration, that is, weight percentage (%), part(s) per million (ppm) or part(s) per billion (ppb), relative to the total weight of the stream under consideration.

[0239] The method according to the invention thus makes it possible to process pyrolysis oils of plastics and / or SRF, completely or partially obtaining an effluent which can be injected into a steam cracking unit.

[0240] (Analysis methods used) The analytical methods and / or standards used to determine the characteristics of the various streams, in particular the feedstocks to be treated and the effluents, are known to the person skilled in the art. They are in particular listed below for information. Other methods that are considered equivalent may also be used, in particular the equivalent IP, EN or ISO methods.

[0241] [Table 1]

[0242] (1) MAV method: described in the paper C. Lopez-Garcia et al., Near Infrared Monitoring of Low Conjugated Diolefins Content in Hydrotreated FCC Gasoline Streams, Oil & Gas Science and Technology - Rev. IFP, Vol. 62 (2007), No. 1, pp. 57-68.

[0243] (Example (according to the present invention)) The feedstock (1) treated in this process is a plastic pyrolysis oil having the characteristics indicated in Table 2.

[0244] [Table 2]

[0245] The feedstock (1) is subjected to a hydroconversion step b) which is carried out in a boiling bed in the presence of hydrogen (6) and an alumina-supported NiMo type catalyst (1% by weight NiO and 6% by weight MoO3) under the conditions presented in Table 3.

[0246] [Table 3]

[0247] The effluent (7) from the hydroconversion step b) is sent to the separation step c). A water stream is injected upstream of the separation step c). The characteristics of the effluent (11) (PI+) obtained after the separation step c) are presented in Table 5.

[0248] The effluent (11) (PI+) is then sent to the fractionation step d). In table 4 the yields of the different fractions obtained at the outlet of the fractionation step d) are shown relative to the feedstock (1) at the inlet of the process chain.

[0249] [Table 4]

[0250] The compounds H2S and NH3 are removed mainly in the form of salts in the aqueous phase which is removed in separation step c).

[0251] The characteristics of the PI-150°C and 150°C+ liquid fractions obtained after fractionation step d) are shown in Table 5.

[0252] [Table 5]

[0253] All three compositions of the effluent (11) (PI+) and the liquid fractions (13) and (14) (PI-150°C and 150°C+) are compatible with a steam cracking unit, for the following reasons: - they do not contain olefins (mono- and di-olefins); - Their elemental chlorine content is very low, below the limit required for steam cracking feedstocks; - the metals, especially iron (Fe), content is as such very low, below the limits required for steam cracker feed (≦5.0 ppm by weight for metals, highly preferably ≦1 ppm by weight; ≦100 ppb by weight for Fe); - Finally, they contain sulfur at a content much lower than the limit required for steam cracking feedstocks (≦500 ppm by weight, preferably ≦200 ppm by weight for S and N).

[0254] The resulting PI-150°C and 150°C+ liquid fractions are advantageously sent to a steam cracking process. [Brief description of the drawings]

[0255] [Figure 1] 1 illustrates a particular embodiment of the method of the present invention.

Claims

1. 1. A method for processing a feedstock containing pyrolysis oil of plastic and / or solid recycled fuel, the method comprising the steps of: a) an optional selective hydrogenation step, which is carried out in the presence of at least one selective hydrogenation catalyst in at least one reaction section fed with the feedstock and a hydrogen-containing gas stream, wherein the temperature is between 100 and 280°C, the hydrogen partial pressure is between 1.0 and 20.0 MPa (abs), and the hourly space velocity is between 0.3 and 10.0 h －１ obtaining a hydrogenated effluent; b) a hydroconversion step carried out in a hydroconversion reaction section using at least one ebullated bed reactor, entrained bed reactor and / or moving bed reactor containing at least one hydroconversion catalyst, to which the feedstock or the hydrogenated effluent obtained from step a) and a gas stream containing hydrogen are fed, the hydroconversion reaction section being operated at a temperature of 300 to 450°C, a hydrogen partial pressure of 5.0 to 20.0 MPa (abs), and an hourly space velocity of 0.03 to 2.0 h －１ obtaining a hydroconverted effluent; c) a separation step, wherein the hydroconverted effluent from step b) and an aqueous solution are fed, said step being carried out at a temperature of 20 to 450°C, to obtain at least one gaseous effluent, an aqueous effluent and a hydrocarbon effluent; d) optionally fractionating all or part of the hydrocarbon effluent obtained from step c) to obtain at least one gaseous effluent, at least one hydrocarbon fraction comprising compounds having a boiling point less than or equal to 150°C, and at least one hydrocarbon fraction comprising compounds having a boiling point greater than 150°C.

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

3. 2. The method of claim 1, wherein when step b) is carried out in an ebullated bed or a moving bed, the hydroconversion catalyst of step b) comprises a supported catalyst comprising a Group VIII metal selected from the group formed by Ni, Pd, Pt, Co, Rh and / or Ru, and optionally a Group VIB metal selected from the group formed by Mo and / or W, on an amorphous mineral support selected from the group formed by alumina, silica, silica-alumina, magnesia, clay and mixtures of at least two of these minerals, and when step b) is carried out in an entrained bed, the hydroconversion catalyst of step b) comprises a dispersed catalyst containing at least one element selected from the group formed by Mo, Fe, Ni, W, Co, V and Ru.

4. 2. The process according to claim 1, further comprising a step a0) of pretreatment of the feedstock, said pretreatment step a0) being carried out upstream of the hydrogenation step a), said pretreatment step a0) comprising a filtration step and / or an electrostatic separation step and / or a washing step with an aqueous solution and / or an adsorption step.

5. 2. The process according to claim 1, wherein the fractionation step d) also comprises fractionation making it possible to obtain, in addition to the gas stream, a naphtha fraction comprising compounds having a boiling point of less than or equal to 150° C., a kerosene fraction comprising compounds having a boiling point of more than 150° C. and less than or equal to 280° C., a diesel fraction comprising compounds having a boiling point of more than 280° C. and less than 360° C., and a hydrocarbon fraction comprising compounds having a boiling point of more than or equal to 360° C., known as the heavy hydrocarbon fraction.

6. 2. The process according to claim 1, wherein the fractionation step d) also comprises fractionating the hydrocarbon fraction containing compounds having a boiling point of 150°C to give a light naphtha fraction containing compounds having a boiling point of less than 80°C and a heavy naphtha fraction containing compounds having a boiling point of 80 to 150°C.

7. The process also includes a hydrotreating step, which is carried out before or after separation step c) or alternatively after fractionation step d), and which is carried out in a hydrotreating reaction section using at least one fixed bed reactor having n catalyst beds, n being an integer greater than or equal to 1, each containing at least one hydrotreating catalyst, and which is supplied with at least a portion of the hydroconverted effluent from step b), or at least a portion of the hydrocarbon effluent obtained from step c), or at least a portion of the hydrocarbon fraction obtained from step d) comprising compounds with a boiling point above 150°C, and a gas stream containing hydrogen, and which is carried out in the hydrotreating reaction section at a temperature of 250 to 430°C, a hydrogen partial pressure of 1.0 to 20.0 MPa (abs), and an hourly volumetric rate of 0.1 to 10.0 h －１ and obtaining a hydrotreated effluent.

8. 8. The method of claim 7, wherein the hydrotreating catalyst comprises a support selected from the group consisting of alumina, silica, silica-alumina, magnesia, clay, and mixtures thereof, and a hydrodehydrogenation functional element comprising at least one element from Group VIII and / or at least one element from Group VIB.

9. The process also includes a hydrocracking step, which is carried out either after the hydrotreating step or after the fractionation step d), and which is carried out in a hydrocracking reaction section using at least one fixed bed containing n catalyst beds, n being an integer greater than or equal to 1, each containing at least one hydrocracking catalyst, and which is fed with at least a portion of the hydrotreated effluent and / or a hydrocarbon fraction obtained from step d) containing compounds having a boiling point above 150°C, and a gas stream containing hydrogen, and which is fed with at least a portion of the hydrotreated effluent and / or a hydrocarbon fraction obtained from step d) containing compounds having a boiling point above 150°C, and a gas stream containing hydrogen, and which is fed with at least a portion of the hydrocracking reaction section using at least a hydrogen partial pressure of 1.5 to 20.0 MPa (abs), and which is fed with at least a hydrogen partial pressure of 0.1 to 10.0 h －１ and obtaining a hydrocracked effluent.

10. The process also includes a second hydrocracking step, which is carried out in a hydrocracking reaction section using at least one fixed bed containing n catalyst beds, where n is an integer greater than or equal to 1, each containing at least one hydrocracking catalyst. The hydrocracking reaction section is fed with the hydrocarbon fraction containing compounds having a boiling point greater than 150°C obtained from the first hydrocracking step and a gas stream containing hydrogen. The hydrocracking reaction section is used at a temperature of 250 to 450°C, a hydrogen partial pressure of 1.5 to 20.0 MPa (abs), and an hourly space velocity of 0.1 to 10.0 h －１ and obtaining a hydrocracked effluent.

11. 10. The method of claim 9, wherein the hydrocracking catalyst comprises a support selected from halogenated alumina, a combination of oxides of boron and aluminum, amorphous silica-alumina, and a zeolite, and a hydrodehydrogenation functional metal comprising at least one metal from Group VIB selected from chromium, molybdenum, and tungsten, either alone or in admixture, and / or at least one metal from Group VIII selected from iron, cobalt, nickel, ruthenium, rhodium, palladium, and platinum.

12. 2. The process of claim 1, comprising the selective hydrogenation step a).

13. 2. The method of claim 1, wherein the selective hydrogenation catalyst comprises a support selected from alumina, silica, silica-alumina, magnesia, clay, and mixtures thereof, and a hydrodehydrogenation functional element 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. 10. The method of claim 1, wherein the feedstock has the following characteristics: the content of aromatic compounds is between 0 and 90% by weight, the content of halogenated compounds is between 2 and 5000 ppm by weight, the content of metallic elements is between 10 and 10,000 ppm by weight; - containing iron element, the content of which is 0 to 100 ppm by weight; the content of elemental silicon is 0 to 1000 ppm by weight; The content of heteroelements provided by sulfur, oxygen and / or nitrogen compounds is between 0 and 20,000 ppm by weight.

15. A product obtainable via the method according to any one of claims 1 to 14.

16. 16. The product of claim 15, comprising, relative to the total weight of the product: the total content of metal elements is less than or equal to 10.0 ppm by weight; - containing iron element, the content of which is 200 ppb by weight or less; - The content of elemental silicon is 5.0 ppm by weight or less; the sulfur content is less than or equal to 500 ppm by weight; the nitrogen content is less than or equal to 50 ppm by weight; The content of elemental chlorine is less than or equal to 10 ppm by weight.