Method for processing pyrolysis oil from plastics and / or solid recovered fuels carrying impurities

Abstract

The present invention relates to a method for treating SRF and / or pyrolysis oil of plastics, comprising: a) optionally, selective hydrogenation of the feedstock; b) hydroconversion in a fluidized bed, a entrained flow bed and / or a moving bed to obtain a hydroconverted effluent; c) separating the hydroconverted effluent in the presence of an aqueous stream to obtain a gaseous effluent, an aqueous liquid effluent and a liquid hydrocarbon-based effluent; d) fractionating the liquid hydrocarbon-based effluent to obtain at least one gas stream and a fraction having a boiling point less than or equal to 385 °C and a fraction having a boiling point higher than 385 °C; e) subjecting the fraction containing compounds having a boiling point less than or equal to 385 °C to hydrotreatment to obtain a hydrotreated effluent; f) separating to obtain at least a gaseous effluent and a hydrotreated liquid hydrocarbon-based effluent.

Description

Technical Field

[0001] The present invention relates to a method for treating plastic pyrolysis oil and / or solid recovered fuel carrying impurities to obtain a hydrocarbon effluent that can be incorporated, at least in part, directly into the naphtha or diesel pool or used as a feedstock for a steam cracking unit. More specifically, the present invention relates to a method for treating a feedstock obtained from the pyrolysis of plastic waste and / or SRF to remove at least some of the impurities that the feedstock may contain in large amounts and to hydrogenate the feedstock so as to be able to upgrade it. Background Art

[0002] Plastics obtained from collection and sorting channels can undergo a pyrolysis step to obtain, in particular, pyrolysis oil. These plastic pyrolysis oils are generally used for power generation by combustion and / or as fuel for industrial or urban heating boilers.

[0003] Solid recovered fuel (SRF), also known as "refuse-derived fuel" or RDF, is a solid non-hazardous waste prepared for energy recovery, regardless of whether they come from household and similar wastes, wastes generated by economic activities, or construction and demolition wastes. SRF is generally a mixture of any combustible waste, such as old tires, food by-products (fats, animal powder, etc.), viscose and wood waste, light debris from shredders (e.g., from old vehicles, electrical and electronic equipment (WEEE)), household and commercial wastes, residues from various waste recycling, including certain municipal wastes, plastic wastes, textiles, and wood, etc. SRF generally contains plastic waste. Nowadays, SRF is mainly for energy recovery. They can be directly used as a fossil fuel substitute in co-incineration facilities (coal and lignite power plants, cement plants, lime kilns) or household waste incineration units, or indirectly used in pyrolysis units dedicated to energy recovery: thus, SRF pyrolysis oil is generally burned for power generation and even used as fuel for industrial or urban heating boilers.

[0004] Another way to upgrade SRF and / or pyrolysis oil from plastics is to use these pyrolysis oils as feedstock for a steam cracking unit to (re)produce olefins, which are the constituent monomers of certain polymers. However, plastic waste or SRF is usually a mixture of several polymers, such as a mixture of polyethylene, polypropylene, polyethylene terephthalate, polyvinyl chloride, and polystyrene. In addition, depending on the application, plastics can also contain other compounds in addition to polymers, such as plasticizers, pigments, colorants, or residues of polymerization catalysts, and other very different organic and mineral impurities from the separation operations in sorting centers, and the selectivity of these operations may not be complete. As a result, the oil obtained from the pyrolysis of plastics or SRF contains many impurities, especially diolefins, metals, silicon, or halogenated compounds, especially chlorine-based compounds, heteroelements such as sulfur, oxygen, and nitrogen, and insoluble substances, the content of which is usually high and incompatible with the steam cracking unit or the units located downstream of the steam cracking unit, especially polymerization processes and selective hydrogenation processes. These impurities can cause operational problems, especially problems of corrosion, coking, or catalytic deactivation, or incompatibility problems in the application of the target polymer. The presence of diolefins can also lead to problems of pyrolysis oil instability, which is characterized by the formation of gums. The gums and insoluble substances that may be present in the pyrolysis oil can cause blockage problems in the process.

[0005] In addition, during the steam cracking step, the yields of the light olefins sought in petrochemistry, especially ethylene and propylene, depend greatly on the quality of the feedstock sent to steam cracking. The BMCI (Bureau of Mines Correlation Index) is usually used to characterize hydrocarbon fractions. This index was developed for hydrocarbon products extracted from crude oil and is calculated by measuring density and average boiling point: straight-chain alkanes equal 0, and benzene equals 100. Thus, if the product being analyzed has an aromatic condensed structure and naphthenes have a BMCI intermediate between alkanes and aromatics, its value will be correspondingly higher. Generally speaking, when the alkane content increases, and thus when the BMCI decreases, the yield of light olefins increases. Conversely, when the BMCI increases, the yield of unwanted heavy compounds and / or coke increases.

[0006] WO 2018 / 055555 proposes an overall process for recycling plastic waste, which is very general and relatively complex, from the various steps of the pyrolysis of plastic waste to the steam cracking step. The method of patent application WO 2018 / 055555 especially includes a step of hydrotreating the liquid phase directly obtained from pyrolysis, preferably under very strict conditions, especially in terms of temperature, for example, at 260 - 300 °C, a step of separating the hydrotreating effluent, and then a step of hydrodealkylating the separated heavy effluent, preferably at high temperature, for example, at 260 - 400 °C.

[0007] The unpublished patent application FR 20 / 01758 describes a process for treating pyrolysis oil of plastics, which comprises:

[0008] a) selectively hydrogenating the feedstock in the presence of hydrogen and a selective hydrogenation catalyst to obtain a hydrogenated effluent;

[0009] b) hydrotreating the hydrogenated effluent in the presence of hydrogen and a hydrotreating catalyst to obtain a hydrotreated effluent;

[0010] c) separating the hydrotreated effluent at a temperature of 50 - 370 °C in the presence of an aqueous stream to obtain a gaseous effluent, an aqueous liquid effluent, and a hydrocarbon-based liquid effluent;

[0011] d) optionally, fractionating all or part of the hydrocarbon-based effluent obtained from step c) to obtain a gas stream and at least two hydrocarbon-based streams, which can be a naphtha fraction and a heavy fraction;

[0012] e) a recycling step, which comprises recycling a part of the hydrocarbon-based effluent obtained from the separation step c) or a part of the hydrocarbon-based stream obtained from the fractionation step d) and / or at least one to the selective hydrogenation step a) and / or the hydrotreating step b).

[0013] According to patent application FR 20 / 01758, the naphtha fraction obtained from the fractionation step can be sent in whole or in part to a steam cracking unit or to a naphtha pool obtained from conventional petroleum feedstocks, or can be recycled to step e).

[0014] The heavier fraction obtained from the fractionation step can be sent in whole or in part to a steam cracking unit or to a diesel or kerosene pool obtained from conventional petroleum feedstocks, or can be recycled to step e).

[0015] The unpublished patent applications FR 20 / 08108 and FR20 / 08106 describe a process for treating pyrolysis oils based on the process of FR20 / 01758, which involves adding one or two hydrocracking steps in a fixed bed after the hydrotreating step. By at least partially converting the heavy fractions into hydrocracked naphtha fractions, these processes make it possible to minimize the yield of heavy fractions and maximize the yield of naphtha fractions, which are fractions that are generally favorable for steam cracking units. Although the heavier fractions can be sent to the steam cracking unit, few refineries prefer this option. The reason for this is that the heavier fractions have a high BMCI and contain more naphthenes, naphthenoaromatics, and aromatic compounds relative to the naphtha fractions, resulting in a higher C / H ratio. This high ratio is the cause of coking in the steam cracker, and thus a steam cracking furnace dedicated to this fraction is required. In addition, the steam cracking of such heavy fractions produces a smaller amount of target products (mainly ethylene and propylene), but more cracked gasoline.

[0016] Due to the impurities contained in the pyrolysis oil, especially when they carry a large amount of impurities, catalyst deactivation in the hydrotreating unit operating in a fixed bed may be observed, which shortens the cycle time. In fact, the main limitation of the fixed bed unit is that the unit must be shut down to replace the catalyst. In addition, pyrolysis oils, especially those carrying a large amount of impurities, cause clogging problems, especially at the heads of preheating furnaces, feed / effluent exchangers, or catalytic reactors.

[0017] Therefore, it would be advantageous to propose a process for treating pyrolysis oils with a durable catalytic cycle that allows the replacement of the catalyst without shutting down the unit, while producing a fraction rich in alkanes that can be easily upgraded in a steam cracking unit.

[0018] Hydroconversion units operating with a fluidized bed, an entrained-bed reactor, or even a moving bed are capable of processing such feeds through a system that allows the addition of fresh catalyst and the removal of spent catalyst without shutting down the unit. The addition of fresh catalyst and the removal of spent catalyst are typically carried out continuously, semi-continuously, or periodically. These systems compensate for catalyst deactivation due to impurities in the pyrolysis products and solve the problem of catalyst bed clogging in fixed bed reactors, giving the hydroconversion unit a longer cycle time without the need to shut down for catalyst replacement.

[0019] In addition, when such a hydroconversion unit is placed upstream of the hydrotreating unit, the cycle time of the latter is increased due to the hydrotreating reactions partially carried out in the hydroconversion unit.

[0020] Similarly, the hydrocracking reaction carried out in the hydroconversion unit can convert at least some heavy compounds into lighter compounds, which can firstly provide a fraction that is generally easier to process to the hydrotreating unit, and secondly obtain a fraction with a lower BMCI, and is thus particularly suitable for the steam cracking unit. Summary of the Invention

[0021] The present invention relates to a method for treating a feedstock containing SRF and / or pyrolysis oil of plastics, comprising:

[0022] a) Optionally, a selective hydrogenation step, which is carried out in a reaction section fed at least with the feedstock and a gas stream containing hydrogen, in the presence of at least one selective hydrogenation catalyst, at a temperature of 100 - 280 °C, a hydrogen partial pressure of 1.0 - 20.0 MPa absolute pressure, and a space velocity of 0.3 - 10.0 h -1 to obtain a hydrogenation effluent;

[0023] b) A hydroconversion step, which is carried out in a hydroconversion reaction section using at least one ebullated bed reactor, entrained bed reactor or moving bed reactor, containing at least one hydroconversion catalyst, feeding at least the feedstock to the hydroconversion reaction section, or at least feeding the hydrogenation effluent obtained at the end of step a) and a gas stream containing hydrogen, the hydroconversion reaction section operating at a temperature of 250 - 450 °C, a hydrogen partial pressure of 1.0 - 20.0 MPa absolute pressure, and a space velocity of 0.05 - 10.0 h -1 to obtain a hydroconversion effluent;

[0024] c) A separation step, which is fed with the hydrocracking effluent obtained from step b) and an aqueous solution, the step being carried out at a temperature of 50 - 450 °C to obtain at least one gaseous effluent, an aqueous effluent and a hydrocarbon-based effluent;

[0025] d) A step of fractionating all or part of the hydrocarbon-based effluent obtained from step c) to obtain at least one gas stream, a hydrocarbon fraction containing compounds with a boiling point less than or equal to 385 °C, and a hydrocarbon fraction containing compounds with a boiling point higher than 385 °C;

[0026] e) A hydrotreating step, which is carried out in a hydrotreating reaction section using at least one fixed bed reactor containing n catalytic beds, where n is an integer greater than or equal to 1, each catalytic bed containing at least one hydrotreating catalyst, the hydrotreating reaction section being fed with at least some of the hydrocarbon fraction containing compounds with a boiling point less than or equal to 385 °C obtained from step d), and a gas stream containing hydrogen, the hydrotreating reaction section operating at a temperature of 250 - 430 °C, a hydrogen partial pressure of 1.0 - 20.0 MPa absolute pressure, and a space velocity of 0.1 - 10.0 h -1operate at a space velocity in time to obtain a hydrotreated effluent;

[0027] f) a separation step, feeding the hydrotreated effluent from step e) to obtain at least a gaseous effluent and a hydrotreated liquid hydrocarbon-based effluent.

[0028] Hereinafter, unless otherwise stated, the term "pyrolysis oil" refers to oil obtained from the pyrolysis of plastics and / or SRF.

[0029] One advantage of the method according to the invention is to purify at least some of the impurities of the pyrolysis oil, which makes it possible to hydrogenate the said oil and thus to upgrade it, in particular by directly incorporating it into a fuel cell and / or by making it compatible with the treatment in a steam cracking unit, in order in particular to be able to obtain light olefins that can be used as monomers in polymer manufacture.

[0030] Another advantage of the invention is to prevent the risk of blockage and / or corrosion of the treatment unit in which the method of the invention is carried out, this risk being exacerbated by the usually large amounts of dienes, metals and halogenated compounds present in the pyrolysis oil.

[0031] Thus, the method of the invention makes it possible to obtain a hydrocarbon-based effluent from pyrolysis oil which is at least partially free of the impurities of the starting pyrolysis oil, thus limiting operability problems such as corrosion, coking or catalytic deactivation problems which these impurities may cause, in particular in a steam cracking unit and / or in units located downstream of the steam cracking unit, in particular polymerization and selective hydrogenation units. Removing at least some of the impurities from the pyrolysis oil will also make it possible to increase the scope of application of the target polymer and reduce application incompatibility.

[0032] The invention participates in the recycling of plastics and / or SRF by proposing a method for treating pyrolysis-produced oil to purify it, hydroconvert it and hydrotreat it. Carrying out the hydroconversion step using a system for adding fresh catalyst and removing spent catalyst without shutting down the unit upstream of the fixed-bed hydrotreating step makes it particularly possible to treat large amounts of pyrolysis oil loaded with impurities.

[0033] Carrying out the hydroconversion step using a system for adding fresh catalyst and removing spent catalyst without shutting down the unit upstream of the fixed-bed hydrotreating step makes it possible not only to obtain a long cycle time for hydroconversion but also to extend the cycle time of the hydrotreating step. In addition, the risk of blockage of one or more catalytic beds in the hydrotreating step is reduced.

[0034] Using a system for adding fresh catalyst and removing spent catalyst in the hydroconversion step without shutting down the units upstream of the fixed-bed hydrotreating step also makes it possible to convert at least some of the heavy compounds into lighter compounds, which makes it possible to obtain an increased yield of fractions suitable for the steam cracking unit and, when this fraction is sent to steam cracking, an increased yield of light olefins, while in particular reducing the risk of formation of a large amount of coke and / or corrosion encountered in one or more subsequent steps, such as in the steam cracking step of pyrolysis oil.

[0035] The oil fraction not hydroconverted, corresponding to the hydrocarbon fraction containing compounds with a boiling point above 385 °C obtained from the fractionation step d), is preferably upgraded by recycling it to the hydroconversion step. In addition, the C2-C4 compounds produced during hydroconversion can also be sent to steam cracking, which makes it possible to increase the yield of light olefins (ethylene and propylene).

[0036] According to a variant, the method comprises the selective hydrogenation step a).

[0037] According to a variant, at least part of the hydrocarbon fraction containing compounds with a boiling point above 385 °C obtained from step d) is recycled to step b).

[0038] According to a variant, the method comprises a step a0) of pretreating the feedstock, said pretreatment step being carried out upstream of the optional selective hydrogenation step a) or upstream of the hydroconversion step and comprising a filtration step and / or a step of washing with a detergent. Water and / or adsorption step.

[0039] According to a variant, all or part of the hydrotreated liquid hydrocarbon-based effluent obtained from step f) is sent to the steam cracking step h), carried out in at least one pyrolysis furnace at a temperature of 700 - 900 °C and a relative pressure of 0.05 - 0.3 MPa.

[0040] According to a variant, the method further comprises a recycling step g), in which a part of the hydrotreated liquid hydrocarbon-based effluent produced by the separation step f) is sent to the optional selective hydrogenation step a) and / or the hydroconversion step b) and / or the hydrotreating step e) and / or the hydrocracking step e′).

[0041] According to a variant, the separation step f) comprises fractionation so as to obtain, in addition to the gas stream, a naphtha fraction containing compounds with a boiling point less than or equal to 175 °C and a diesel fraction containing compounds with a boiling point above 175 °C and below 385 °C.

[0042] According to a variant, the method further comprises a hydrocracking step e′) carried out in the hydrocracking reaction section, using at least one fixed bed comprising n catalytic beds, where n is an integer greater than or equal to 1, each comprising: at least one hydrocracking catalyst, the hydrocracking reaction section being fed at least with the hydrotreated effluent obtained from step e) and / or a diesel fraction containing compounds with a boiling point higher than 175 °C and lower than 385 °C obtained from step f), and a gas stream containing hydrogen, the hydrocracking reaction section operating at a temperature of 250 - 450 °C, a hydrogen partial pressure of 1.5 - 20.0 MPa absolute pressure and a space velocity of 0.1 - 10.0 h -1 to obtain a hydrocracking effluent, which is fed to the separation step f).

[0043] According to a variant, the separation step f) further comprises fractionating a naphtha fraction containing compounds with a boiling point less than or equal to 175 °C into a light naphtha fraction containing compounds with a boiling point less than 80 °C and a heavy naphtha fraction containing compounds with a boiling point of 80 to 175 °C.

[0044] According to this variant, at least part of the heavy naphtha fraction is sent to an aromatic complex comprising at least one naphtha reforming step and / or at least part of the light naphtha fraction is sent to a steam cracking step h).

[0045] According to a variant, the selective hydrogenation catalyst of step a) comprises a support selected from alumina, silica, silica - alumina, magnesia, clay and mixtures thereof and a hydro - dehydrogenation function containing at least one Group VIII element and at least one Group VIB element, or at least one Group VIII element.

[0046] According to a variant, when step b) is carried out in a ebullated bed or a moving bed, the hydroconversion catalyst of step b) comprises a supported catalyst, the supported catalyst comprising a Group VIII metal selected from Ni, Pd, Pt, Co, Rh and / or Ru on an amorphous mineral support selected from alumina, silica, silica - alumina, magnesia, clay and mixtures of at least two of these minerals, optionally a Group VIB metal selected from Mo and / or W, and when step b) is carried out in a entrained bed, the hydroconversion catalyst of step b) comprises a dispersed catalyst containing at least one element selected from Mo, Fe, Ni, W, Co, V and Ru.

[0047] According to one variant, the hydrotreating catalyst of step e) comprises a support selected from alumina, silica, silica-alumina, magnesia, clay and mixtures thereof and a hydrodehydrogenation function comprising at least one Group VIII element and / or at least one Group VIB element.

[0048] According to one variant, the hydrocracking catalyst of step e′) comprises a support selected from halogenated alumina, a combination of boron and aluminum oxides, amorphous silica-alumina and zeolites, and a hydro-dehydrogenation function comprising at least one Group VIB metal selected from chromium, molybdenum and tungsten, alone or as a mixture, and / or at least one Group VIII metal selected from iron, cobalt, nickel, ruthenium, rhodium, palladium and platinum.

[0049] According to one variant, the feedstock has the following characteristics:

[0050] - the content of aromatic compounds is between 0% and 90% by weight,

[0051] - the content of halogenated compounds is between 2 and 5000 ppm by weight,

[0052] - the content of metal elements is between 10 and 10000 ppm by weight,

[0053] - the content of iron elements is between 0 and 100 ppm by weight,

[0054] - the content of silicon elements is between 0 and 1000 ppm by weight.

[0055] The present invention also relates to a product obtainable by the treatment process according to the present invention.

[0056] According to one variant, relative to the total weight of the product, the product comprises:

[0057] - the total content of metal elements is less than or equal to 5.0 ppm by weight,

[0058] - the content of iron elements is less than or equal to 100 ppb by weight,

[0059] - the content of silicon elements is less than or equal to 1.0 ppm by weight,

[0060] - the sulfur content is less than or equal to 500 ppm by weight,

[0061] - the nitrogen content is less than or equal to 100 ppm by weight,

[0062] - the content of chlorine elements is less than or equal to 10 ppm by weight.

[0063] According to the present invention, unless otherwise stated, pressure is absolute pressure, also written as abs., and is given in absolute MPa (or MPa abs.).

[0064] According to the present invention, the expressions "comprising between... and..." and "... to..." are equivalent and mean that the limits of the interval are included within the range of the values. If this is not the case and if the limits are not included within the range, the present invention will give such indication.

[0065] For the purposes of the present invention, the various ranges of parameters of a given step, such as pressure ranges and temperature ranges, can be used alone or in combination. For example, for the purposes of the present invention, a range of preferred pressure values can be combined with a range of more preferred temperature values.

[0066] Hereinafter, specific and / or preferred embodiments of the present invention may be described. When technically feasible, they can be implemented alone or in combination without limitation of the combination.

[0067] Hereinafter, the groups of chemical elements are given according to the CAS classification (CRC Handbook of Chemistry and Physics, published by CRC Press, edited by D.R. 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.

[0068] The metal content is measured by X-ray fluorescence.

[0069] Detailed description

[0070] Raw materials

[0071] According to the present invention, "plastic pyrolysis oil or SRF pyrolysis oil" is an oil, advantageously in liquid form at room temperature, obtained by pyrolysis of plastics, preferably plastic waste, especially plastic waste from collection and sorting channels, or from the pyrolysis of SRF. It particularly contains a mixture of hydrocarbon compounds, especially alkanes, alkenes, cycloalkanes and aromatics. At least 80% by weight of these hydrocarbon compounds preferably have a boiling point below 700 °C, preferably below 550 °C. In particular, depending on the source of the pyrolysis oil, the oil may contain up to 70% by weight of alkanes, up to 90% by weight of alkenes and up to 90% by weight of aromatics, it being understood that alkanes, alkenes and aromatics are 100% by weight of the hydrocarbon compounds.

[0072] The density of the pyrolysis oil measured at 15 °C according to the ASTM D4052 method is generally between 0.75 and 0.99 g / cm 3 and preferably between 0.75 and 0.95 g / cm 3 between.

[0073] The pyrolysis oil may also contain and usually does contain impurities, such as metals, especially iron, silicon or halogenated compounds, especially chlorinated compounds. These impurities can be present in the pyrolysis oil in high amounts, such as up to 500 weight ppm or even 1000 weight ppm or even 5000 weight ppm of halogen elements provided by the halogenated compounds, up to 2500 weight ppm, or even 10,000 ppm of metal or metalloid elements by weight. Alkali metals, alkaline earth metals, transition metals, post-transition metals and metalloids can be regarded as contaminants of metallic nature and are referred to as metal or metal or metalloid elements. The pyrolysis oil may contain up to 200 weight ppm or even 1000 weight ppm of silicon, and up to 15 weight ppm or even 100 weight ppm of iron. The pyrolysis oil may also contain other impurities, such as heteroelements mainly provided by sulfur compounds, oxygen compounds and / or nitrogen compounds, the content of which is usually less than 20,000 ppm by weight of the heteroelements and preferably less than 10,000 ppm by weight of the heteroelements.

[0074] The method according to the invention is particularly suitable for treating pyrolysis oil carrying impurities. This means that the feedstock has the following characteristics:

[0075] - An aromatic content between 0 and 90% by weight, usually between 20% and 90% by weight, and can be between 50% and 90% by weight;

[0076] - A halogen content between 2 and 5000 ppm by weight, usually between 200 and 5000 ppm by weight, and can be between 500 and 5000 ppm by weight;

[0077] * The content of metal elements is between 10 and 10,000 ppm by weight, usually between 2000 and 10,000 ppm by weight, and can be between 2250 and 5000 ppm by weight;

[0078] * Including an iron element content between 0 and 100 ppm by weight, usually between 10 and 100 ppm by weight, and can be between 15 and 100 ppm by weight;

[0079] * The silicon element content is from 0 to 1000 weight ppm, usually 100 to 1000 weight ppm, and can be 200 to 1000 weight ppm.

[0080] The method according to the invention is particularly suitable for treating pyrolysis oil containing a large amount of impurities. This means that the feedstock has the following characteristics:

[0081] - The content of aromatic compounds is between 50% and 90% by weight;

[0082] - The content of halogenated compounds is between 500 and 5000 ppm by weight;

[0083] - The content of metal elements is between 2250 and 10000 ppm by weight;

[0084] - Including an iron element content between 15 and 100 ppm by weight;

[0085] - The content of silicon element is between 200 and 1000 ppm by weight.

[0086] The feedstock for the process according to the invention comprises at least one SRF and / or plastic pyrolysis oil. The feedstock can consist only of one or more plastic pyrolysis oils or only of one or more SRF pyrolysis oils or only of a mixture of SRF and one or more plastic pyrolysis oils. Preferably, the feedstock comprises at least 50% by weight, preferably 50% to 100% by weight, particularly preferably 75% to 100% by weight of SRF and / or plastic pyrolysis oil.

[0087] The feedstock for the process according to the invention can also comprise conventional petroleum-based feedstocks and / or feedstocks obtained from the conversion of lignocellulosic resources, which are then co-processed with SRF and / or plastic pyrolysis oil.

[0088] SRF and / or plastic pyrolysis oil can be obtained from thermal, catalytic pyrolysis treatment or can be prepared by hydro-pyrolysis (pyrolysis in the presence of a catalyst and hydrogen).

[0089] Pretreatment (optional)

[0090] The feedstock comprising pyrolysis oil can advantageously be pretreated in an optional pretreatment step a0) before an optional selective hydrogenation step a) or a hydroconversion step b) when step a) is absent, to obtain a pretreated feedstock for feeding to step a) or step b).

[0091] This optional pretreatment step a0) makes it possible to reduce the amount of contaminants that may be present in the feedstock comprising pyrolysis oil, in particular the amount of silicon and metals. Thus, the optional step a0) of pretreating the feedstock comprising pyrolysis oil is advantageously carried out, particularly when the feedstock comprises more than 50 ppm by weight, particularly more than 100 ppm by weight, and more particularly more than 200 ppm by weight of metal elements.

[0092] The optional pretreatment step a0) can be carried out by any method known to those skilled in the art for reducing the amount of contaminants. It can in particular include a filtration step and / or a step of washing with water and / or an adsorption step.

[0093] According to one variant, the optional pretreatment step a0) is carried out in an adsorption section operating in the presence of at least one adsorbent. The optional pretreatment step a0) is carried out at a temperature of 0 - 150 °C, preferably 5 - 100 °C, and at a pressure of 0.15 - 10.0 MPa absolute pressure, preferably 0.2 - 1.0 MPa absolute pressure. The adsorption section is advantageously carried out in the presence of at least one adsorbent having a specific surface area greater than or equal to 100 m 2 / g, preferably greater than or equal to 200 m 2 / g, and preferably an adsorbent of alumina type. The specific surface area of the at least one adsorbent is advantageously less than or equal to 600 m 2 / g, especially less than or equal to 400 m 2 / g. The specific surface area of the adsorbent is the surface area measured by the BET method, i.e., the specific surface area determined by nitrogen adsorption according to the standard ASTM D 3663 - 78 established by the Brunauer - Emmett - Teller method described in the journal The Journal of the American Chemical Society, 60, 309 (1938).

[0094] Advantageously, the adsorbent contains less than 1 wt% of metal elements and preferably contains no metal elements. The term "metal elements of the adsorbent" shall be understood to mean the elements of Groups 6 - 10 of the Periodic Table (new IUPAC classification).

[0095] The adsorption section of the optional step a0) includes at least one adsorption tower containing the adsorbent, preferably includes at least two adsorption towers, preferably two to four adsorption towers. When the adsorption section includes two adsorption towers, one operating mode can be the mode called "swing" operation according to the specialized terminology, where one tower is online, i.e., in use, while the other tower is standby. When the adsorbent in the online tower fails, the tower is isolated, and the standby tower is made online, i.e., in use. Then, the failed adsorbent can be regenerated in situ and / or replaced with fresh adsorbent so that once the other tower is isolated, the tower containing it can be made online again.

[0096] Another operating mode is a tower with at least two towers operating in series. When the adsorbent in the top tower fails, the first tower is isolated and the failed adsorbent is regenerated in situ or replaced with fresh adsorbent. Then, the tower is put back in the on-line state at the last position, and so on. This operating mode is called the replaceable mode, or PRS for a replaceable reactor system, or "lead and lag" according to the specialized term. The combination of at least two adsorption towers makes it possible to overcome the possible and potential rapid poisoning and / or adsorbent plugging due to the combined action of metal contaminants, diolefins, gums obtained from diolefins, and insoluble substances that may be present in the pyrolysis oil to be treated. The reason is that the presence of at least two adsorption towers facilitates the replacement and / or regeneration of the adsorbent, advantageously without stopping the pretreatment unit or even the process, thus making it possible to reduce the risk of plugging and therefore avoid the stoppage of the unit due to plugging, in order to control costs and limit the consumption of the adsorbent.

[0097] The optional pretreatment step a0) may also optionally be fed with at least a portion of the recycle stream, advantageously obtained from step g) of the process, either as a mixture with the feedstock containing pyrolysis oil or separately from the feedstock containing pyrolysis oil.

[0098] The optional pretreatment step a0) is thus capable of obtaining a pretreated feedstock, which is then fed to the selective hydrogenation step a), if present, or the hydroconversion step b).

[0099] Selective hydrogenation step a) (optional)

[0100] According to the present invention, the process comprises a selective hydrogenation step a) of a feedstock containing pyrolysis oil, which is carried out in the presence of hydrogen, under hydrogen pressure and temperature conditions such that the feedstock can be kept in the liquid phase, and with the amount of soluble hydrogen exactly necessary for the selective hydrogenation of the diolefins present in the pyrolysis oil. Thus, the selective hydrogenation of the diolefins in the liquid phase makes it possible to avoid or at least limit the formation of "gums", i.e., the polymerization of diolefins and thus the formation of oligomers and polymers, which can plug the reaction section of the hydrotreating step e). The selective hydrogenation step a) makes it possible to obtain a hydrogenated effluent, i.e., an effluent with a reduced olefin content, especially a reduced diolefin content.

[0101] According to the present invention, the selective hydrogenation step a) is carried out in a reaction section fed at least with the raw material containing pyrolysis oil or with the pretreated raw material obtained from an optional pretreatment step a0), and with a gas stream containing hydrogen (H2). Optionally, the reaction section of step a) can also be fed with at least a portion of a recycle stream, advantageously obtained from an optional step g), either as a mixture with the optionally pretreated raw material or separately from the optionally pretreated raw material, advantageously directly at the inlet of at least one reactor of the reaction section of step a). Introducing at least a portion of the recycle stream into the reaction section of the selective hydrogenation step a) advantageously allows diluting the impurities of the optionally pretreated raw material and controlling in particular the temperature in the reaction section.

[0102] The reaction section comprises selective hydrogenation in the presence of at least one selective hydrogenation catalyst, advantageously at a temperature of 100 - 280 °C, preferably 120 - 260 °C, more preferably 130 - 250 °C, at a hydrogen partial pressure of 1.0 - 20.0 MPa absolute, preferably 5.0 - 15.0 MPa absolute and at a space velocity (HSV) of 0.3 - 10.0 h -1 , preferably 0.5 - 5.0 h -1 , preferably in a fixed bed. Here, the space velocity (HSV) is defined as the ratio of the hourly volume flow of the optionally pretreated raw material containing plastic pyrolysis oil to the volume of one or more catalysts. The amount of the gas stream containing hydrogen (H2) fed to the reaction section of step a) is advantageously such that the hydrogen coverage is 1 - 200 Nm 3 hydrogen / m 3 raw material (Nm 3 / m 3 ), preferably 1 - 50 Nm 3 hydrogen / m 3 raw material (Nm 3 / m 3 ), preferably 5 - 20 Nm 3 hydrogen / m 3 raw material (Nm 3 / m 3 ). The hydrogen coverage is defined as the ratio of the volume flow of hydrogen employed under standard temperature and pressure conditions to the volume flow of the "fresh" raw material (i.e., the raw material to be treated which has optionally been pretreated, without considering any recycle fractions) at 15 °C (in standard m 3 , written as Nm 3 , H2 / m 3 raw material). The gas stream containing hydrogen fed to the reaction section of step a) can consist of a hydrogen supply and / or in particular of recycle hydrogen obtained from the separation step c).

[0103] The selective hydrogenation step a) is preferably carried out in a fixed bed. It can also be carried out in a fluidized bed or a moving bed.

[0104] Advantageously, the reaction section of step a) comprises 1 - 5 reactors. According to a particular embodiment of the invention, the reaction section comprises 2 - 5 reactors which operate in a replaceable mode, denoted by the term PRS for a replaceable reactor system or by the term "lead and lag". The combination of at least two reactors in PRS mode makes it possible to isolate one reactor, discharge the deactivated catalyst, refill the reactor with fresh catalyst and return the reactor to service without stopping the process. The PRS technique is described in particular in patent FR2681871.

[0105] Advantageously, reactor inserts, such as those of the filter plate type, can be used to prevent clogging of one or more reactors. Examples of filter plates are described in patent FR3051375.

[0106] Advantageously, the selective hydrogenation catalyst comprises a support, preferably a mineral support, and a hydrodehydrogenation function.

[0107] According to a variant, the hydrodehydrogenation function particularly comprises at least one Group VIII element, preferably selected from nickel and cobalt, and at least one Group VIB element, preferably selected from molybdenum and tungsten. According to this variant, the total content of the oxides of the Group VIB and Group VIII metal elements is preferably 1 - 40% by weight, preferably 5 - 30% by weight, relative to the total weight of the catalyst. The weight ratio of one or more Group VIB metals to one or more Group VIII metals, expressed as metal oxides, is preferably 1 - 20, preferably 2 - 10.

[0108] According to this variant, the reaction section of step a) comprises, for example, a selective hydrogenation catalyst comprising 0.5 - 12% by weight of nickel, preferably 1 - 10% by weight of nickel, expressed as nickel oxide NiO, relative to the weight of the catalyst, on a support, preferably a mineral support, preferably an alumina support, and 1 - 30% by weight of molybdenum, preferably 3 - 20% by weight of molybdenum, expressed as molybdenum trioxide MoO3, relative to the weight of the catalyst.

[0109] According to another variant, the hydrodehydrogenation function comprises at least one Group VIII element, preferably nickel, and preferably consists of it. According to this variant, the content of nickel oxide is preferably 1 - 50% by weight, preferably 10 - 30% by weight, relative to the weight of the catalyst. Such catalysts are preferably used in their reduced form, on a support which is preferably mineral, preferably on an alumina support.

[0110] The carrier of the at least one selective hydrogenation catalyst is preferably selected from alumina, silica, silica-alumina, magnesia, clays and mixtures thereof. The carrier may contain other dopant compounds, in particular oxides selected from boron oxide, in particular boric anhydride, zirconium dioxide, cerium dioxide, titanium oxide, phosphorus pentoxide and mixtures of these oxides. Preferably, the at least one selective hydrogenation catalyst comprises an alumina carrier, optionally doped with phosphorus and optionally doped with boron. When phosphorus pentoxide P2O5 is present, its concentration is less than 10% by weight relative to the weight of the alumina, advantageously at least 0.001% by weight relative to the total weight of the alumina. When boric anhydride 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 may be, for example, γ (gamma) or η (eta) alumina.

[0111] The selective hydrogenation catalyst is, for example, in the form of an extrudate.

[0112] Very preferably, in order to hydrogenate the diolefins as selectively as possible, in addition to the above selective hydrogenation catalyst, step a) may also use at least one selective hydrogenation catalyst for step a), which catalyst comprises less than 1% by weight of nickel, expressed as nickel oxide NiO, relative to the weight of the catalyst, and at least 0.1% by weight of nickel, preferably 0.5% by weight of nickel, and less than 5% by weight of molybdenum, expressed as molybdenum trioxide MoO3, relative to the weight of the catalyst, and at least 0.1% by weight of molybdenum, preferably 0.5% by weight of molybdenum. This catalyst with a small addition of metals is preferably placed upstream of the above selective hydrogenation catalyst.

[0113] Optionally, a feedstock comprising pyrolysis oil of plastics, which has optionally been pretreated and / or optionally pre-mixed with at least a portion of a recycle stream advantageously obtained from an optional step g), may be mixed with a gaseous stream comprising hydrogen before its introduction into the reaction section.

[0114] The feedstock, which has optionally been pretreated and / or optionally mixed with at least a portion of a recycle stream advantageously obtained from an optional step g) and / or optionally as a mixture with a gaseous stream, may also be heated before its introduction into the reaction section of step a), for example by heat exchange with the hydroconversion effluent from step b), to reach a temperature close to the temperature of the feedstock in the reaction section of the feedstock.

[0115] The impurities in the hydrogenated effluent obtained at the end of step a), in particular the content of diolefins, are reduced relative to the content of the same impurities, in particular diolefins, contained in the feedstock of the process. The selective hydrogenation step a) can generally convert at least 90% and preferably at least 99% of the diolefins contained in the initial feedstock. Step a) can also at least partially remove other contaminants, such as silicon. The hydrogenated effluent obtained at the end of the selective hydrogenation step a) is sent, preferably directly, to the hydroconversion step b).

[0116] Hydroconversion step b)

[0117] According to the invention, the treatment process comprises a hydroconversion step b) carried out in a hydroconversion reaction section which involves at least one ebullated bed reactor, entrained bed reactor and / or moving bed reactor, which contains at least one hydroconversion catalyst, and feeds at least the feedstock or the hydrogenated effluent obtained from step a) (optionally as a mixture with at least a portion of a recycle stream, which advantageously is obtained from an optional step g)) and a gas stream containing hydrogen into the hydroconversion reaction section.

[0118] Advantageously, step b) involves hydroconversion reactions well known to those skilled in the art, more specifically hydrotreating reactions such as the hydrogenation of olefins, aromatics, halogenated compounds, hydrodemetallization, hydrodesulfurization, hydrodenitrogenation, etc. and hydrocracking reactions (HCK), which result in the opening of naphthenic rings or the fractionation of paraffins into several lower molecular weight fragments, thermal cracking and condensation reactions (formation of coke), although the latter are not desired.

[0119] The hydroconversion reaction section of step b) can also be fed with at least a portion of a recycle stream, which advantageously is obtained from an optional step g). The one or more portions of the recycle stream or the total amount of the recycle stream can be introduced into the hydroconversion reaction section as a mixture with the hydrogenated effluent obtained from step a) or separately. Introducing at least a portion of the recycle stream advantageously makes it possible to dilute the impurities still present in the hydrogenated effluent and to control the temperature in one or more catalytic beds of the hydroconversion reaction section involving highly exothermic reactions, in particular to limit the temperature rise.

[0120] Optionally, step b) can include a heating section located upstream of the hydroconversion reaction section and in which the feedstock or hydrogenated effluent obtained from step a) is heated to a temperature suitable for hydroconversion, i.e. a temperature of 250 - 450 °C. Thus, the optional heating section can include one or more exchangers, preferably allowing heat exchange between the feedstock or hydrogenated effluent and the hydroconversion effluent and / or a preheating furnace.

[0121] Advantageously, the hydroconversion reaction section is carried out at a pressure equal to that used in the reaction section (if any) of the selective hydrogenation step a), but at a temperature higher than that of the reaction section of the selective hydrogenation step a). Thus, regardless of whether a ebullated bed reactor, a entrained bed reactor and / or a moving bed reactor is used, the hydroconversion reaction section is advantageously carried out at a hydroconversion temperature of 250 to 450 °C, preferably 350 to 420 °C, at a hydrogen partial pressure of 1.0 - 20.0 MPa absolute (preferably at a hydrogen partial pressure of 5.0 - 15.0 MPa absolute) and at a space velocity (HSV) of 0.05 - 10.0 h -1 , preferably 0.1 - 5.0 h -1 . According to the present invention, the "hydroconversion temperature" corresponds to the average temperature in the hydroconversion reaction section of step b). The hydroconversion temperature is advantageously determined by a person skilled in the art according to the catalytic system used, the equipment 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 space velocity (HSV) is herein defined as the ratio of the hourly volume flow rate of the hydrogenation effluent obtained from step a) to the volume of one or more catalysts. The hydrogen coverage in step b) is advantageously 50 - 1000 Nm 3 hydrogen / m 3 fresh feedstock fed to step a), preferably 60 - 500 Nm 3 hydrogen / m 3 fresh feedstock fed to step a), preferably 100 - 300 Nm 3 hydrogen / m 3 fresh feedstock fed to step a). The hydrogen coverage is herein defined as the ratio of the volume flow rate of hydrogen employed under standard temperature and pressure conditions to the volume flow rate of the fresh feedstock fed to step a) (i.e., the feedstock containing pyrolysis oil or the optionally pre-treated feedstock fed to step a)) (in standard m 3 , denoted as Nm 3 , H2 / m 3 fresh feedstock). The hydrogen can consist of the feed and / or recycled hydrogen obtained especially from the separation step c).

[0122] An important feature of the process according to the present invention is that the hydroconversion step is carried out in a reaction section, allowing the addition of fresh catalyst and the removal of spent catalyst without shutting down the unit. Such a system is a hydroconversion unit operating in an ebullated bed, an entrained bed and / or even a moving bed. Thus, the addition of fresh catalyst and the removal of spent catalyst can be carried out continuously, semi-continuously or periodically.

[0123] Fluidized bed hydroconversion step b)

[0124] Thus, according to the first variant, the hydroconversion step b) is carried out in a hydroconversion reaction section comprising at least one ebullated bed reactor.

[0125] The function of an ebullated bed reactor, which includes upward circulation of reactor liquid through a stirred bed of catalyst, is generally well known. A mixture of feedstock and hydrogen passes upward from the bottom through the bed of catalytic particles at a certain flow rate such that the particles are subject to forced random movement, while the liquid and gas pass upward through the bed from the bottom. The movement of the catalytic bed is controlled by the circulating liquid flow, so that in the steady state, the mass of the catalyst does not rise above a definable level in the reactor. The vapors and the hydrogenated liquid reach a region substantially free of catalyst through the upper layer of the catalytic particle bed and then they are discharged from the upper part of the reactor. A portion of the reactor liquid is continuously recycled to the reactor. The ebullated bed technology uses supported catalysts, usually in the form of extrudates or beads, which typically have a diameter of about 1 mm or less. The catalyst remains within the reactor and is not discharged with the product. The catalytic activity can be kept constant by on-line catalyst replacement. Thus, there is no need to shut down the unit to replace the spent catalyst or to increase the reaction temperature of the entire cycle to compensate for deactivation. In addition, working under constant operating conditions enables a constant product yield and quality to be obtained throughout the cycle. Further, since the catalyst is kept stirred by the large circulation of liquid, the pressure drop across the reactor remains low and constant and the heat of reaction is rapidly averaged over the catalytic bed.

[0126] The spent catalyst is partially replaced by fresh or new catalyst by removing it from the bottom of the reactor and introducing fresh catalyst at the top or bottom of the reactor at regular time intervals, that is to say for example in bursts or almost continuously. For example, fresh catalyst can be introduced daily. The rate of replacement of the spent catalyst by fresh catalyst can be, for example, from about 0.01 kg to about 10 kg per cubic meter of feedstock. The removal and the replacement are carried out using equipment capable of enabling the hydroconversion step to operate continuously. The unit generally includes an internal circulation pump for keeping the catalyst in the ebullated bed by continuously circulating at least a portion of the liquid withdrawn from the top of the reactor and reinjected at the bottom of the reactor. The spent catalyst withdrawn from the reactor can also be sent to a regeneration zone where the carbon and sulfur contained therein are removed and then the regenerated catalyst is returned to the hydroconversion step. The regenerated catalyst can also be sent to a regeneration zone where a treatment (presulfidation, addition, etc.) aimed at increasing the activity of the catalyst is carried out and then the regenerated catalyst is returned to the hydroconversion step.

[0127] Catalysts used in fluidized beds are widely sold. These are granular catalysts, the size of which never reaches that of the catalysts used in entrained beds. The catalysts are usually in the form of extrudates or beads. Usually, they contain at least one hydrodehydrogenation element deposited on an amorphous support. Usually, the supported catalysts contain a Group VIII metal selected from Ni, Pd, Pt, Co, Rh and / or Ru, optionally a Group VIB metal selected from Mo and / or W, on an amorphous mineral support, and the support is selected from 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.

[0128] The total content of the oxides of the Group VIB and Group VIII metal elements is preferably from 0.1% to 40% by weight, more preferably from 5% to 35% by weight, relative to the total weight of the catalyst. The weight ratio of one or more Group VIB metals, expressed as metal oxides, to one or more Group VIII metals is preferably from 1.0 to 20, more preferably from 2.0 to 10. For example, the hydroconversion reaction section of step b) of the process contains a hydroconversion catalyst which contains from 0.5% to 10% by weight of nickel, expressed as nickel oxide NiO, relative to the total weight of the hydroconversion catalyst, preferably from 1% to 8% by weight of nickel, and from 1.0% to 30% by weight of molybdenum, expressed as molybdenum trioxide MoO3, relative to the total weight of the hydroconversion catalyst, preferably from 3.0% to 29% by weight of molybdenum.

[0129] The support of the hydroconversion catalyst is advantageously selected from alumina, silica, silica-alumina, magnesia, clay and mixtures thereof. The support may also contain other dopant compounds, especially oxides selected from boron oxide, especially boric anhydride, zirconium dioxide, cerium dioxide, 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 boron. When phosphorus pentoxide P2O5 is present, its concentration is less than 10% by weight relative to the weight of alumina, advantageously at least 0.001% by weight relative to the total weight of alumina. When boric anhydride B2O5 is present, its concentration is less than 10% by weight relative to the weight of alumina, and advantageously at least 0.001% by weight relative to the total weight of alumina. The alumina used may be, for example, γ or η alumina.

[0130] The hydroconversion catalyst is, for example, in the form of an extrudate.

[0131] Advantageously, the hydroconversion catalyst used in step b) of the process has a surface area greater than or equal to 250 m 2 / g, preferably greater than or equal to 300 m 2The specific surface area per g. The specific surface area of the hydroconversion catalyst is advantageously less than or equal to 800 m 2 / g, preferably less than or equal to 600 m 2 / g, especially less than or equal to 400 m 2 / g. The specific surface area of the hydroconversion catalyst is measured by the BET method, i.e., the specific surface area determined by nitrogen adsorption according to the standard ASTM D 3663 established by the Brunauer - Emmett - Teller method described in the Journal of the American Chemical Society, 60, 309 (1938). This specific surface area enables further improvement in the removal of pollutants, especially the removal of metals such as silicon.

[0132] The hydroconversion catalyst differs from the hydrotreating catalyst mainly in the porosity suitable for treating impurities, especially metal impurities, and especially the presence of large porosity.

[0133] According to another aspect of the present invention, the hydroconversion catalyst as described above further comprises one or more organic compounds containing oxygen and / or nitrogen and / or sulfur. Such catalysts are generally denoted by the term "catalyst with additives". Usually, the organic compounds are selected from compounds containing one or more chemical functional groups selected from carboxyl, alcohol, thiol, thioether, sulfone, sulfoxide, ether, aldehyde, ketone, ester, carbonate, amine, nitrile, imide, oxime, urea, and amide functional groups, or compounds containing a furan ring or sugars.

[0134] Entrained bed hydroconversion step b)

[0135] According to a second variant, the hydroconversion step b) is carried out in a hydroconversion reaction section that includes at least one entrained bed reactor, also known as a slurry reactor. The feedstock, hydrogen, and catalyst are injected from below and flow as an upward flow. The effluent of the hydroconversion, the unconsumed hydrogen, and the catalyst are withdrawn from the top. The slurry hydroconversion technology uses a catalyst dispersed in the form of very small particles, with a size of dozens of microns or less (usually from 0.001 to 100 microns). The catalyst or its precursor is injected together with the feedstock to be converted at the inlet of the reactor. The catalyst is converted together with the feedstock and the products through the reactor and then carried out of the reactor together with the reaction products. They are found after separation of the heaviest parts.

[0136] The slurry catalyst preferably contains a catalyst containing at least one element selected from Mo, Fe, Ni, W, Co, V, and Ru. These catalysts are generally monometallic or bimetallic (for example, by combining non - precious Group VIIIB elements (Co, Ni, Fe) and Group VIB elements (Mo, W)).

[0137] The catalyst used can be a heterogeneous solid powder (such as natural ore, iron sulfate, etc.), a dispersed catalyst obtained from a water-soluble precursor ("water-soluble dispersed catalyst") such as phosphomolybdic acid, ammonium molybdate, or a mixture of ammonia water and molybdenum oxide or nickel oxide.

[0138] Preferably, the catalyst used is from a precursor soluble in the organic phase ("oil-soluble dispersed catalyst"). The precursor is an organometallic compound, such as naphthenates of Mo, Co, Fe or Ni, or polycarbonyl compounds of these metals, such as 2-ethylhexanoates of Mo or Ni, acetylacetonates of Mo or Ni, salts of C7-C12 fatty acids of Mo or W, etc. When the catalyst is bimetallic, they can be used in the presence of a surfactant to improve the dispersion of the metals.

[0139] 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 that can be used in the process according to the present invention are widely described in the literature.

[0140] The concentration of the catalyst, expressed as a metal element, is generally between 1 and 10,000 ppm relative to the feedstock.

[0141] Generally, the catalyst is prepared before injecting the feedstock. The preparation process is adjusted according to the state and nature of the precursor. In all cases, the precursor is sulfided (non-in-situ or in-situ) to form a catalyst dispersed in the feedstock.

[0142] For the preferred case of "oil-soluble" catalysts, in a typical process, the precursor is mixed with a carbonaceous feedstock (which may be part of the feedstock to be treated, an external feedstock, a recycled fraction, etc.), the mixture is optionally at least partially dried, and then or simultaneously sulfided by adding a sulfur compound (preferably H2S) and heating. The preparation of these catalysts is described in the prior art.

[0143] Additives can be added during the preparation of the catalyst or before injecting the slurried catalyst into the reactor. These additives are described in the literature.

[0144] Preferred solid additives are mineral oxides such as alumina, silica, mixed Al / Si oxides, spent catalysts supported (e.g., on alumina and / or silica) which contain at least one Group VIII element (e.g., Ni, Co) and / or at least one Group VIB element (e.g., Mo, W). Reference will be made, for example, to the catalysts described in patent application US 2008 / 177124. Carbon-based solids with a low hydrogen content (e.g., 4% hydrogen), such as optionally pretreated coke, can also be used. Mixtures of these additives can also 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 section is from 0 to 10% by weight, preferably from 1 to 3% by weight, and the content of the catalytic solution is from 0 to 10% by weight, preferably between 0 and 1% by weight based on the weight of the injected feedstock.

[0145] When the hydroconversion step b) is carried out in an entrained bed reactor, a filtration step is required to recover the catalyst before feeding the hydroconverted effluent to step c).

[0146] Moving bed hydroconversion step b)

[0147] According to a third variant, the hydroconversion step b) is carried out in a hydroconversion reaction section comprising at least one moving bed reactor.

[0148] The feedstock and hydrogen can flow upwards (countercurrent process) or downwards (cocurrent process) in the moving bed reactor. The catalyst gradually flows downwards by gravity and exhibits plug flow in the catalytic zone. It can be withdrawn from below by any suitable means, such as a lift (elevator) (referred to as a "hoist"). An on-line unit ensures the semi-continuous renewal of the moving bed reactor catalyst: some spent catalyst is discharged at the bottom of the reactor while fresh catalyst is introduced at the top of the reactor. The temperature therein is controlled by quenching between or within the reactors.

[0149] Preferably, spherical catalysts with a diameter between 0.5 and 6 mm and preferably between 1 and 3 mm are used instead of extruded catalysts to obtain better fluidity. When withdrawing the spent catalyst from the bottom of the reactor, the entire catalytic bed moves in plug flow, descending by a height corresponding to the volume of the withdrawn catalyst. The degree of expansion of the catalytic 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 degree of expansion is measured by methods known to those skilled in the art.

[0150] The hydroconversion catalyst used in the moving bed in step b) of the process according to the invention is advantageously a catalyst comprising a support, preferably an amorphous support and very preferably alumina, and at least one Group VIII metal selected from nickel and cobalt, and preferably nickel, the Group VIII element preferably being used in combination with at least one Group VIB metal selected from molybdenum and tungsten, and preferably the Group VIB metal being molybdenum. Preferably, the hydroconversion catalyst comprises nickel as the Group VIII element and molybdenum as the Group VIB element. The nickel content is advantageously between 0.5% and 10% by weight expressed as nickel oxide (NiO) and preferably between 1% and 6% by weight, and the molybdenum content is advantageously between 1% and 30% by weight (expressed as molybdenum trioxide (MoO3)), preferably from 4% to 20% by weight, the percentages being expressed as weight percentages relative to the total weight of the catalyst. The catalyst is advantageously in the form of extrudates or beads. The catalyst may also advantageously comprise phosphorus and preferably a content of less than 20% by weight and preferably less than 10% by weight of phosphorus pentoxide P2O5, the percentage being expressed as a weight percentage relative to the total weight of the catalyst. The catalyst may also be a catalyst supplemented with an organic compound as described above.

[0151] According to a further variant, the hydroconversion step b) may be carried out in a hydroconversion reaction section comprising a combination in any order of at least one ebullated bed reactor, at least one entrained bed reactor and / or at least one moving bed reactor.

[0152] Preferably, step b) is carried out in a hydroconversion reaction section comprising at least one ebullated bed reactor.

[0153] Separation step c)

[0154] According to the invention, the treatment process comprises a separation step c), which is advantageously carried out in at least one washing / separation section, fed at least with the hydroconversion effluent obtained from step b) and an aqueous solution, to obtain at least one gaseous effluent, an aqueous effluent and a hydrocarbon-based effluent.

[0155] The gaseous effluent obtained at the end of step c) advantageously contains hydrogen, preferably containing at least 90% by volume, preferably at least 95% by volume of hydrogen. Advantageously, the gaseous effluent may be at least partially recycled to the selective hydrogenation step a) and / or the hydroconversion step b) and / or the hydrotreating step e) and / or the hydrocracking step e'), and the recycling system may include a purification section.

[0156] The aqueous effluent obtained at the end of step c) advantageously contains ammonium salts and / or hydrochloric acid. The aqueous effluent may be recycled to step c).

[0157] This separation step c) in particular makes it possible to remove ammonium chloride salts, which are formed by the reaction between chloride ions released by the hydrogenation of chlorinated compounds, in particular in the form of HCl, followed by dissolution in water, during step b), and ammonium ions generated by the hydrogenation of nitrogen-containing compounds, in particular in the form of NH3, during step b) and / or provided by the injection of amines followed by dissolution in water, and thus limits the risk of blockage due to the precipitation of ammonium chloride salts, in particular in the transport pipelines and / or in the sections of the process according to the invention and / or in the transport pipelines of the steam cracker. It also makes it possible to remove hydrochloric acid formed by the reaction of hydrogen ions and chloride ions.

[0158] Depending on the content of chlorinated compounds in the initial feedstock to be treated, a stream containing amines, such as monoethanolamine, diethanolamine and / or methyldiethanolamine, can be injected upstream of the selective hydrogenation step a), between the selective hydrogenation step a) and the hydroconversion step b), and / or between the hydroconversion step b) and the separation step c), preferably upstream of the selective hydrogenation step a) (if present), to ensure that a sufficient amount of ammonium ions binds to the chloride ions formed during the hydroconversion step, so that it is possible to limit the formation of hydrochloric acid and thus limit the corrosion downstream of the separation section.

[0159] Advantageously, the separation step c) includes injecting an aqueous solution, preferably water, into the hydroconversion effluent obtained from step b) upstream of the washing / separation section, in order to at least partially dissolve the ammonium chloride salts and / or hydrochloric acid, and thus improve the removal of chlorinated impurities and reduce the risk of blockage caused by the accumulation of ammonium chloride salts.

[0160] The separation step c) is advantageously carried out at a temperature of 50 to 450 °C, preferably 100 to 440 °C, more preferably 200 to 420 °C. It is important to carry out this step within this temperature range (so as not to overcool the hydroconversion effluent) risking blockage of the pipelines due to the precipitation of ammonium chloride salts. Advantageously, the 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, to facilitate the recycling of hydrogen.

[0161] The washing / separation section of step c) can be carried out at least partially in common or separate washing and separation equipment, which is well-known (separation vessels, pumps, heat exchangers, washing towers, etc. that can operate at various pressures and temperatures).

[0162] In one embodiment of the present invention, separation step c) comprises injecting an aqueous solution into the hydroconversion effluent obtained from step b), followed by a washing / separation section which advantageously includes a separation stage for obtaining at least one aqueous effluent carrying an ammonium salt, a washed hydrocarbon-based liquid effluent, and a partially washed gaseous effluent. Subsequently, the aqueous effluent carrying the ammonium salt and the washed hydrocarbon-based liquid effluent can be separated in a decantation vessel to obtain the hydrocarbon-based effluent and the aqueous effluent. The partially washed gaseous effluent can be introduced in parallel into a washing column, in which it circulates countercurrently with respect to an aqueous stream which preferably has the same properties as the aqueous solution injected into the hydroconversion effluent, which makes it possible to remove at least partially, preferably completely, the hydrochloric acid contained in the partially washed gaseous effluent and thus to obtain the gaseous effluent which preferably consists essentially of hydrogen and an acidic aqueous stream. The aqueous effluent obtained from the decantation vessel can optionally be mixed with the acidic aqueous stream and optionally used as a mixture with the acidic aqueous stream in a water recycle loop for feeding into separation step c), into the aqueous solution upstream of the washing / separation section and / or into the aqueous stream in the washing column. The water recycle loop can include a supply of water and / or an alkaline solution and / or a discharge for removing dissolved salts.

[0163] In another embodiment of the present invention, separation step c) can advantageously include a "high-pressure" washing / separation section which operates at a pressure close to that of the selective hydrogenation step a) and / or the hydroconversion step b), preferably between 1.0 and 20.0 MPa, in order to facilitate the recycling of hydrogen. This "high-pressure" section of step c) can be supplemented by a "low-pressure" part, preferably at a pressure generally between 0.5 and 10.0 MPa, in order to obtain a hydrocarbon-based liquid fraction which does not contain part of the gases dissolved under high pressure and which is intended to be sent to fractionation step d) for treatment.

[0164] One or more gas fractions obtained from separation step c) can be subjected to one or more additional purification and one or more separation operations in order to recover at least one hydrogen-rich gas (which can be recycled upstream of step a) and / or b) and / or e) and / or e')) and / or light hydrocarbons (in particular ethane, propane and butane), which can advantageously be sent, individually or as a mixture, to one or more furnaces of the steam cracking step h).

[0165] Part or all, preferably all, of the hydrocarbon-based effluent obtained from separation step c) is sent to fractionation step d)

[0166] Fractionation step d)

[0167] The process according to the invention comprises fractionating all or part, preferably all, of the hydrocarbon-based 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 higher than 385 °C.

[0168] Step d) can in particular remove gases dissolved in the hydrocarbon-based liquid effluent, such as ammonia, hydrogen sulphide and light hydrocarbons having 1 to 4 carbon atoms.

[0169] The fractionation step d) is advantageously carried out at a pressure of less than or equal to 1.0 MPa absolute, preferably 0.1 - 1.0 MPa absolute.

[0170] According to one embodiment, step d) can be carried out in a section advantageously comprising at least one stripping column equipped with a reflux circuit comprising a reflux vessel. The stripping column is fed with the hydrocarbon-based liquid effluent obtained from step c) and a vapour stream. The hydrocarbon-based liquid effluent obtained from step c) can optionally be heated before entering the stripping column. Thus, the lightest compounds are entrained at the top of the column and enter the reflux circuit comprising the reflux vessel, in which a gas / liquid separation takes place. The gas phase comprising the light hydrocarbons is withdrawn from the reflux vessel as a gas stream. The fraction comprising compounds having a boiling point less than or equal to 385 °C is advantageously withdrawn from the reflux vessel. The hydrocarbon fraction comprising compounds having a boiling point greater than 385 °C is advantageously withdrawn at the bottom of the stripping column.

[0171] According to other embodiments, the fractionation step d) can involve a stripping column followed by a distillation column or only a distillation column.

[0172] All or part of the fraction comprising compounds having a boiling point less than or equal to 385 °C (naphtha fraction and diesel fraction) is sent to a hydrotreating step e).

[0173] The fraction comprising compounds having a boiling point higher than 385 °C (unconverted oil) is advantageously at least partly recycled to the hydroconversion step b). It can also be burned to produce heat and / or electricity.

[0174] A purge can be provided on the recycle of the fraction comprising compounds having a boiling point higher than 385 °C obtained from step d). Depending on the operating conditions of the process, the purge can be from 0 to 50% by weight, and preferably 5 to 20% by weight, of the fraction obtained from step d).

[0175] One or more gas fractions obtained from the fractionation step d) can be subjected to one or more additional purification and one or more separation to recover at least light hydrocarbons, in particular ethane, propane and butane, which can advantageously be sent, alone or as a mixture, to one of the furnaces of the steam cracking step h).

[0176] Hydrotreating step e)

[0177] According to the present invention, the treatment method comprises a hydrotreating step e) carried out in a hydrotreating reaction section, using at least one fixed bed reactor comprising n catalytic beds, where n is an integer greater than or equal to 1, each containing at least one hydrotreating catalyst, feeding into said hydrotreating reaction section at least a portion of a hydrocarbon fraction comprising compounds having a boiling point less than or equal to 385 °C obtained from step d) and a gas stream comprising hydrogen to obtain a hydrotreated effluent.

[0178] Advantageously, step c) involves hydrotreating reactions well known to those skilled in the art, more particularly hydrotreating reactions such as aromatic hydrogenation, hydrodesulfurization and hydrodenitrogenation. In addition, hydrogenation of olefins and remaining halogenated compounds and hydrodemetallization are continued.

[0179] Advantageously, said step e) is carried out in a hydrotreating reaction section comprising at least one, preferably one to five fixed bed reactors each comprising n catalytic beds, where n is an integer greater than or equal to one, preferably one to ten, preferably two to five, and each of said one or more beds contains at least one, preferably not more than ten, hydrotreating catalysts. When the reactor comprises several catalytic beds, i.e. at least two, preferably two to ten, preferably two to five catalytic beds, said catalytic beds are arranged in series in the reactor.

[0180] Feeding into said hydrotreating reaction section at least part of said hydrocarbon fraction, said hydrocarbon fraction comprising compounds having a boiling point less than or equal to 385 °C obtained from step d) and a gas stream comprising hydrogen, advantageously operating at the level of the first catalytic bed of the first reactor.

[0181] The hydrotreating reaction section of step e) may also be fed with at least a portion of a recycle stream, advantageously obtained from an optional step g). The one or more fractions of said recycle stream or the total amount of the recycle stream may be introduced into said hydrotreating reaction section as a mixture with the hydrocarbon fraction comprising compounds having a boiling point less than or equal to 385 °C obtained from step d) or introduced separately. The one or more fractions of said recycle stream or the total amount of the recycle stream may be introduced into said hydrotreating reaction section and into one or more catalytic beds of the hydrotreating reaction section of step e). Introducing at least a portion of said recycle stream advantageously makes it possible to dilute the impurities still present in the hydrotreated effluent and to control the temperature in the catalytic beds of the hydrotreating reaction section, in particular limiting the temperature rise which relates to highly exothermic reactions.

[0182] The hydrotreating reaction section is advantageously carried out at a hydrotreating temperature between 250 and 430 °C, preferably between 300 and 400 °C, at a hydrogen partial pressure between 1.0 and 20.0 MPa absolute, preferably between 3.0 and 15.0 MPa absolute and a space velocity (HSV) between 0.1 and 10.0 h -1 between, preferably between 0.1 and 5.0 h -1 between, preferably between 0.2 and 2.0 h -1 between, preferably between 0.2 and 1.0 h -1 between. According to the invention, the "hydrotreating temperature" corresponds to the average temperature in the hydrotreating reaction section of step e). In particular, it corresponds to the weighted average bed temperature (WABT) according to the terminology known to those skilled in the art. The hydrotreating temperature is advantageously determined according to the catalytic system used, the equipment and its configuration. For example, the hydrotreating temperature (or WABT) is calculated as follows:

[0183] WABT=(T 入口 +2×T 出口 ) / 3

[0184] where T 入口 : the temperature of the effluent at the inlet of the hydrotreating reaction section with a boiling point less than or equal to 385 °C, T 出口 : the effluent temperature at the outlet of the hydrotreating reaction section.

[0185] The space velocity (HSV) is hereby defined as the hourly volume flow rate of the hydrocarbon fraction containing compounds with a boiling point less than or equal to 385 °C obtained from step d) divided by the volume of one or more catalysts. The hydrogen coverage in step e) is advantageously 50 to 2000 Nm 3 hydrogen / m 3 feedstock fed to step e), preferably 100 to 1000 Nm 3 hydrogen / m 3 feedstock fed to step e), preferably preferably 120 and 800 Nm 3 of hydrogen / m 3 feedstock fed to step e). The hydrogen coverage is hereby defined as the ratio of the volume flow rate of hydrogen obtained under standard temperature and pressure conditions to the volume flow rate of the feedstock fed to step e) (in standard m 3 , denoted as Nm 3 , H2 / m 3 fresh feedstock). The hydrogen can consist of the feed and / or in particular the supply and / or recycled hydrogen obtained from the separation step c).

[0186] Preferably, an additional gas stream containing hydrogen is advantageously introduced at the inlet of each reactor operating in particular in series, and / or at the inlet of each catalytic bed starting from the second catalytic bed of the hydrotreating reaction section. These additional gas streams are also referred to as cooling streams. They make it possible to control the temperature in the hydrotreating reactors, where the reactions involved are generally highly exothermic.

[0187] Advantageously, the hydrotreating catalyst used in step e) can be selected from known hydrodemetallation, hydrotreating or silicon scavenging catalysts, in particular catalysts for treating petroleum fractions, and combinations thereof. Known hydrodemetallation catalysts are, for example, those described in patents EP 0113297, EP 0113284, US 5221656, US 5827421, US7119045, US 5622616 and US 5089463. Known hydrotreating catalysts are, for example, those described in patents EP0113297, EP 0113284, US 6589908, US 4818743 or US 6332976. Known silicon scavenging catalysts are, for example, those described in patent applications CN 102051202 and US 2007 / 080099.

[0188] In particular, the hydrotreating catalyst comprises a support, preferably a mineral support, and at least one metal element having a hydrodehydrogenation function. The metal element having a hydrodehydrogenation function advantageously comprises at least one Group VIII element, preferably selected from nickel and cobalt, and / or at least one Group VIB element, preferably selected from molybdenum and tungsten. The total content of the oxides of the Group VIB and Group VIII metal elements is preferably from 0.1% to 40% by weight, preferably from 5% to 35% by weight, relative to the total weight of the catalyst. The weight ratio of one or more Group VIB metals, expressed as metal oxides, to one or more Group VIII metals is preferably from 1.0 to 20, preferably from 2.0 to 10. For example, the hydrotreating reaction section of step b) of the process comprises a hydrotreating catalyst which comprises from 0.5% to 10% by weight of nickel, preferably from 1% to 8% by weight of nickel, expressed as nickel oxide NiO, on a mineral support, and from 1.0% to 30% by weight of molybdenum and / or tungsten, preferably from 3.0% to 29% by weight, expressed as molybdenum oxide MoO3 or tungsten oxide WO3, relative to the total weight of the hydrotreating catalyst.

[0189] The support of the hydrotreating catalyst is advantageously selected from alumina, silica, silica-alumina, magnesia, clays and mixtures thereof. The support may also contain other dopant compounds, in particular oxides selected from boron oxide, in particular boric anhydride, zirconium dioxide, cerium dioxide, 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. When phosphorus pentoxide P2O5 is present, its concentration is less than 10% by weight relative to the weight of alumina, advantageously at least 0.001% by weight relative to the total weight of alumina. When boric anhydride B2O5 is present, its concentration is less than 10% by weight relative to the weight of alumina, and advantageously at least 0.001% by weight relative to the total weight of alumina. The alumina used may be, for example, γ or η alumina.

[0190] The hydrotreating catalyst is, for example, in the form of an extrudate.

[0191] Advantageously, the hydrotreating catalyst used in step e) of the process has a specific surface area greater than or equal to 250 m 2 / g, preferably greater than or equal to 300 m 2 / g. The specific surface area of the hydrotreating catalyst is advantageously less than or equal to 800 m 2 / g, preferably less than or equal to 600 m 2 / g, in particular less than or equal to 400 m 2 / g. The specific surface area of the hydrotreating catalyst is measured by the BET method, i.e. the specific surface area determined by nitrogen adsorption according to the standard ASTM D 3663-78 established by the Brunauer-Emmett-Teller method described in the Journal of the American Chemical Society, 60, 309 (1938). This specific surface area allows for further improvement in the removal of pollutants, in particular the removal of metals such as silicon.

[0192] According to another aspect of the invention, the hydrotreating catalyst as described above also comprises one or more organic compounds containing oxygen and / or nitrogen and / or sulfur. Such catalysts are generally denoted by the term "additive-containing catalysts". Generally, the organic compounds are selected from compounds containing one or more chemical functional groups selected from carboxyl, alcohol, thiol, thioether, sulfone, sulfoxide, ether, aldehyde, ketone, ester, carbonate, amine, nitrile, imide, oxime, urea and amide functional groups, or compounds containing a furan ring or sugars.

[0193] The preparation of the catalyst of step a), b), e) or e') is known and generally comprises the steps of impregnating a support with a Group VIII metal and a Group VIB metal (if present), as well as optionally phosphorus and / or boron, then drying, and then optionally calcining. In the case of the catalyst with additives, the preparation is generally carried out by simple drying without calcining after introducing the organic compound. The term "calcining" as used herein refers to a heat treatment in a gas containing air or oxygen at a temperature of greater than or equal to 200 °C. Before the catalyst is used in the process step, the catalyst is generally sulfided to form the active substance.

[0194] In a preferred embodiment of the present invention, the hydrotreating reaction section comprises several fixed-bed reactors, preferably two to five, very preferably two to four fixed-bed reactors, each comprising n catalytic beds, where n is an integer greater than or equal to one, preferably one to ten, preferably two to five, and is advantageously operated in series and / or in parallel and / or in a replaceable (or PRS) mode and / or in a "switching" mode. The various optional operating modes, the PRS (or leading and lagging) mode and the switching mode, are well known to those skilled in the art and are defined advantageously later. The advantage of a hydrotreating reaction section comprising multiple reactors is to optimize the treatment of the hydrocarbon fraction obtained from step d) containing compounds with a boiling point less than or equal to 385 °C, while making it possible to reduce the risk of clogging of one or more catalytic beds and thus avoid the shutdown of the unit due to clogging.

[0195] According to a very preferred embodiment of the present invention, the hydrotreating reaction section comprises at least one fixed-bed reactor, preferably consisting of one reactor or two reactors in series, the one or more fixed-bed reactors comprising from one to five catalytic beds arranged in series, and each containing from one to ten hydrotreating catalysts, wherein at least one of the hydrotreating catalysts advantageously comprises a support and at least one metal element, the metal element preferably comprising at least one Group VIII element, preferably selected from nickel and cobalt, and / or at least one Group VIB element, preferably selected from molybdenum and tungsten.

[0196] Optionally, step e) may include a heating section located upstream of the hydrotreating reaction section, and wherein the hydrocarbon fraction obtained from step d) containing compounds with a boiling point less than or equal to 385 °C is heated to a temperature suitable for hydrotreating, i.e., a temperature between 250 and 430 °C. Thus, the optional heating section may include one or more exchangers, preferably allowing heat exchange between the hydrocarbon fraction obtained from step d) containing compounds with a boiling point less than or equal to 385 °C and the effluent from the hydrotreating, and / or a preheating furnace.

[0197] Hydrotreating step e) advantageously allows the optimization of the treatment of the hydrocarbon fraction obtained from step d) and containing compounds with a boiling point less than or equal to 385 °C. This makes it possible to significantly remove residual impurities, in particular sulfur and nitrogen compounds and residual metals.

[0198] Hydrocracking step e′) (optional)

[0199] According to a variant, the process of the present invention may include a hydrocracking step e′), either directly after the hydrotreating step e) or after the separation step f) of the heavy fraction (diesel fraction).

[0200] The fraction containing compounds with a boiling point less than or equal to 385 °C includes a fraction containing compounds with a boiling point below 175 °C (naphtha fraction) and a fraction containing compounds with a boiling point above 175 °C and below 385 °C (diesel fraction). When it is desired to minimize the yield of the diesel fraction and maximize the yield of the naphtha fraction, the diesel fraction can be at least partially converted into a naphtha fraction by hydrocracking, and even a part of the heavy naphtha fraction can be converted into light naphtha, i.e., this fraction is generally favorable for a steam cracking unit.

[0201] Therefore, the process of the present invention may include a hydrocracking step e′) carried out in a hydrocracking reaction section, using at least one fixed bed containing n catalytic beds, where n is an integer greater than or equal to 1, each containing at least one hydrocracking catalyst, feeding the hydrotreated effluent obtained from step e) and / or the diesel fraction containing compounds with a boiling point above 175 °C and below 385 °C obtained from step f) and a gas stream containing hydrogen to the hydrocracking reaction section, the hydrocracking reaction section operating at a temperature of 250 to 450 °C, a hydrogen partial pressure of 1.5 to 20.0 MPa absolute pressure and a space velocity of 0.1 - 10.0 h -1 to obtain a hydrocracked effluent that enters the separation step f).

[0202] Advantageously, step e′) involves hydrocracking reactions well known to those skilled in the art, and more particularly makes it possible to convert heavy compounds such as compounds with a boiling point greater than 175 °C into the hydrotreated effluent obtained in step b) with a boiling point less than or equal to 175 °C. Subsequently, other reactions can be carried out, such as the hydrogenation of olefins or aromatics, hydrodemetallization, hydrodesulfurization, hydrodenitrogenation, etc.

[0203] Advantageously, the step e′) is carried out in a hydrocracking reaction section, the hydrocracking reaction section including at least one, preferably one to five fixed bed reactors including n catalytic beds, n being an integer greater than or equal to one, preferably one to ten, preferably two to five, each of the one or more beds containing at least one, preferably no more than ten hydrocracking catalysts.

[0204] Hydrotreating step e) and hydrocracking step e′) can advantageously be carried out in the same reactor or in different reactors. When they are carried out in the same reactor, the reactor contains several catalytic beds, the first catalytic bed contains a hydrotreating catalyst, and the subsequent catalytic beds contain a hydrocracking catalyst.

[0205] The hydrocracking reaction section is advantageously carried out at a hydrotreating temperature of 250 to 450 °C, preferably 320 to 430 °C, a hydrogen partial pressure of 1.5 to 20 MPa absolute pressure, and a space velocity (HSV) between 0.1 and 10.0 h -1 and preferably between 0.1 and 5.0 h -1 and preferably between 0.2 and 4 h -1 According to the present invention, the "hydrocracking temperature" corresponds respectively to the average temperature in the hydrocracking reaction section of step c). In particular, it corresponds to the weighted average bed temperature (WABT) according to the specialized terminology, which is well known to those skilled in the art. The hydrocracking temperature is advantageously determined according to the catalytic system used, the equipment and its configuration. For example, the hydrocracking temperature (or WABT) is calculated as follows:

[0206] WABT = (T 入口 + 2x T 出口 ) / 3

[0207] where T 入口 : the temperature of the hydrotreated effluent at the inlet of the hydrocracking reaction section, T 出口 : the temperature of the effluent at the outlet of the hydrocracking reaction section.

[0208] The space velocity (HSV) is defined herein as the ratio of the hourly volume flow rate of the hydrotreated effluent obtained from step e) / the volume of one or more catalysts. The hydrogen coverage in step e′) is advantageously 80 - 2000 Nm 3 hydrogen / m 3 of the feedstock fed to step e′), preferably 200 - 1800 Nm 3 hydrogen / m 3 of the feedstock fed to step e′). The hydrogen coverage is defined herein as the ratio of the volume flow rate of hydrogen employed under standard temperature and pressure conditions to the volume flow rate of the feedstock fed to step e′) (in standard m 3 , denoted as Nm 3 , H2 / m 3 feedstock). The hydrogen can consist of the feed and / or recycled hydrogen obtained especially from separation steps c) and d).

[0209] Preferably, an additional gas stream containing hydrogen is advantageously introduced at the inlet of each reactor operating especially in series, and / or at the inlet of each catalytic bed starting from the second catalytic bed of the hydrocracking reaction section. These additional gas streams are also called cooling streams. They make it possible to control the temperature in the hydrocracking reactors where the reactions involved are generally highly exothermic.

[0210] The hydrocracking step e′) can be carried out in one or two steps. When carried out in two steps, the effluent from the first hydrocracking step e′) is separated so that a fraction containing compounds with a boiling point higher than 175 °C (diesel fraction) can be obtained, which is introduced into the second hydrocracking step. This configuration is particularly suitable when only a naphtha fraction is desired. The operating conditions and catalysts used in the two hydrocracking steps can be the same or different.

[0211] These operating conditions used in step e′) of the process according to the invention generally make it possible to obtain a single-pass conversion of greater than 15% by weight and even more preferably from 20% to 80% by weight, which is converted into a product containing at least 80% by volume of compounds with a boiling point less than or equal to 175 °C, preferably less than 160 °C and preferably less than 150 °C. When the process is carried out in two hydrocracking steps, the single-pass conversion in the second step remains moderate to maximize the selectivity to the naphtha fraction (boiling point less than or equal to 175 °C, especially between 80 °C and less than or equal to 175 °C). The single-pass conversion is limited by using a high recycle ratio in the second hydrocracking step loop. This ratio is defined as the flow rate of the feed from step f) to the flow rate of the feedstock from step a), and this ratio is preferably from 0.2 to 4, preferably from 0.5 to 2.5.

[0212] Thus, the hydrocracking step e′) is not necessarily able to convert all the compounds with a boiling point higher than 175 °C (diesel fraction) into compounds with a boiling point less than or equal to 175 °C (naphtha fraction). After the fractionation step f), more or less of the majority of the compounds with a boiling point higher than 175 °C may thus be retained. To increase the conversion, at least part of the unconverted fraction can be recycled to step e′) as described below. Another part can be purged. Depending on the operating conditions of the process, the purge can be from 0 to 10% by weight, and preferably from 0.5 to 5% by weight, of the fraction containing compounds with a boiling point higher than 175 °C relative to the incoming feedstock.

[0213] According to the invention, the hydrocracking step e′) is carried out in the presence of at least one hydrocracking catalyst.

[0214] One or more hydrocracking catalysts used in the hydrocracking step e') are conventional hydrocracking catalysts known to those skilled in the art, which are of the bifunctional type combining an acid function and a hydrogenation-dehydrogenation function and optionally at least one binder matrix. The acid function is provided by a large surface area (usually 150 - 800 m 2 / g) support having surface acidity, such as halogenated (especially chlorinated or fluorinated) alumina, a combination of boron and aluminum oxides, amorphous silica-alumina, and zeolites. The hydrogenation-dehydrogenation function is provided by at least one metal of Group VIB of the periodic table and / or at least one metal of Group VIII.

[0215] Preferably, one or more hydrocracking catalysts used in step e') comprise a hydrogenation-dehydrogenation function comprising at least one Group VIII metal selected from iron, cobalt, nickel, ruthenium, rhodium, palladium, and platinum, preferably selected from cobalt and nickel. Preferably, the one or more catalysts further comprise at least one Group VIB metal selected from chromium, molybdenum, and tungsten, individually or as a mixture, and preferably selected from molybdenum and tungsten. Hydrogenation-dehydrogenation functions of the NiMo, NiMoW, or NiW type are preferred.

[0216] Preferably, the content of the Group VIII metal in one or more hydrocracking catalysts is advantageously 0.5 - 15% by weight, preferably 1 - 10% by weight, the percentages being expressed as weight percentages of the oxide relative to the total weight of the catalyst.

[0217] Preferably, the content of the Group VIB metal in one or more hydrocracking catalysts is advantageously 5 - 35% by weight, preferably 10 - 30% by weight, the percentages being expressed as weight percentages of the oxide relative to the total weight of the catalyst.

[0218] One or more hydrocracking catalysts used in step e') may also optionally comprise at least one promoter element deposited on the catalyst, selected from phosphorus, boron, and silicon, optionally at least one Group VIIA element (preferably chlorine and fluorine), optionally at least one Group VIIB element (preferably manganese), and optionally at least one Group VB element (preferably niobium).

[0219] Preferably, one or more hydrocracking catalysts used in step e') comprise at least one amorphous or poorly crystalline porous mineral matrix of the oxide type, selected from alumina, silica, silica-alumina, aluminates, alumina-boron oxide, magnesia, silica-magnesia, zirconia, titania, or clays, individually or as a mixture, and preferably alumina or silica-alumina, individually or as a mixture.

[0220] Preferably, the silica-alumina contains more than 50% by weight of alumina, preferably more than 60% by weight of alumina.

[0221] Preferably, one or more hydrocracking catalysts used in step e') further optionally contain zeolites selected from Y zeolites, preferably USY zeolites, alone or in combination with other zeolites selected from β, ZSM-12, IZM-2, ZSM-22, ZSM-23, SAPO-11, ZSM-48 or ZBM-30 zeolites (alone or as a mixture). Preferably, the zeolite is a single USY zeolite.

[0222] When the catalyst contains zeolites, the content of zeolites in one or more hydrocracking catalysts is advantageously 0.1-80% by weight, preferably 3-70% by weight, and the percentages are expressed as percentages of the zeolite relative to the total weight of the catalyst.

[0223] Preferred catalysts contain at least one Group VIB metal and optionally at least one Group VIII non-noble metal, at least one promoter element, preferably phosphorus, at least one Y zeolite and at least one alumina binder, and are preferably composed of them.

[0224] Even more preferred catalysts contain nickel, molybdenum, phosphorus, USY zeolite and optionally β zeolite and alumina, and are preferably composed of them.

[0225] Another preferred catalyst contains nickel, tungsten, alumina and silica-alumina, and is preferably composed of them.

[0226] Another preferred catalyst contains nickel, tungsten, USY zeolite, alumina and silica-alumina, and is preferably composed of them.

[0227] The hydrocracking catalyst is in the form of extrudates, for example.

[0228] According to another aspect of the invention, the hydrocracking catalyst as described above further contains one or more organic compounds containing oxygen and / or nitrogen and / or sulfur. Such catalysts are generally denoted by the term "catalyst with additives". Generally, the organic compounds are selected from compounds containing one or more chemical functional groups selected from carboxyl, alcohol, thiol, thioether, sulfone, sulfoxide, ether, aldehyde, ketone, ester, carbonate, amine, nitrile, imide, oxime, urea and amide functional groups, or compounds containing a furan ring or sugars.

[0229] Separation step f)

[0230] According to the invention, the treatment method includes a separation step f), feeding the hydrotreating effluent obtained from step e) or the hydrocracking effluent obtained from the optional step e') to obtain at least one gaseous effluent and a hydrotreating liquid hydrocarbon-based effluent.

[0231] The separated part of step f) is advantageously operated in a known separation device (separation vessels, pumps, heat exchangers, scrubbers, etc. that can operate at various pressures and temperatures).

[0232] The gaseous effluent obtained at the end of step f) advantageously contains hydrogen, preferably at least 90% by volume, preferably at least 95% by volume of hydrogen. Advantageously, the gaseous effluent can be at least partially recycled to the selective hydrogenation step a), and / or the hydroconversion step b), and / or the hydrotreating step e), and / or the optional hydrocracking step e′), and the recycling system may include a purification section.

[0233] The gaseous effluent obtained at the end of step f) may also contain light hydrocarbons, especially ethane, propane and butane, which can advantageously be conveyed, individually or as a mixture, to one or more furnaces of the steam cracking step h).

[0234] Step f) can in particular remove gases dissolved in the liquid hydrocarbon-based effluent, such as ammonia, hydrogen sulfide and light hydrocarbons containing from 1 to 4 carbon atoms.

[0235] The fractionation step f) is advantageously carried out at a pressure less than or equal to 1.0 MPa absolute, preferably from 0.1 to 1.0 MPa absolute.

[0236] According to one embodiment, step f) can be carried out in a section advantageously comprising at least one stripping column equipped with a reflux circuit including a reflux vessel. The stripping column is fed with the hydrotreated effluent obtained from step e) and a steam stream. The hydrotreated effluent obtained from step e) can optionally be heated before entering the stripping column. Thus, the lightest compounds are entrained at the top of the column and enter the reflux circuit including the reflux vessel, in which a gas / liquid separation takes place. The gas phase containing light hydrocarbons is withdrawn from the reflux vessel as a gas stream. The hydrotreated liquid hydrocarbon-based effluent is the fraction containing hydrotreated compounds with a boiling point less than or equal to 385 °C (naphtha fraction and diesel fraction), which is advantageously withdrawn at the bottom of the stripping column.

[0237] According to other embodiments, the fractionation step f) can include a stripping column followed by a distillation column or consist only of a distillation column.

[0238] In a particular embodiment, the separation step f) can include fractionation such that, in addition to the gas stream, a naphtha fraction containing compounds with a boiling point less than or equal to 175 °C, preferably from 80 to 175 °C, and a diesel fraction containing compounds with a boiling point greater than 175 °C and less than 385 °C can be obtained.

[0239] The naphtha fraction can 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 can also be sent to recovery step g).

[0240] The diesel fraction can also be sent in whole or in part to a steam cracking unit, or to a jet fuel and diesel pool obtained respectively from conventional petroleum-based feedstocks, or to recycle step g), or introduced into hydrocracking step e′) (when it is present).

[0241] In another specific embodiment, the naphtha fraction containing compounds with a boiling point less than or equal to 175 °C is fractionated into a heavy naphtha fraction containing compounds with a boiling point of 80 - 175 °C and a light naphtha fraction containing compounds with a boiling point less than 80 °C. At least a portion of the heavy naphtha fraction is sent to an aromatics complex unit including at least one naphtha reforming step to produce aromatics. The heavy naphtha fraction can also be sent at least in part to the following steam cracking step h). According to this embodiment, at least a portion of the light naphtha fraction is sent to the following steam cracking step h).

[0242] Step g) (optional) Recycle the hydrotreated liquid hydrocarbon-based effluent obtained from step f)

[0243] The process according to the present invention can include a recycle step g), in which a portion of the hydrotreated liquid hydrocarbon-based effluent obtained from separation step f) is recovered to form a recycle stream, and the recycle stream is sent upstream of at least one of the reaction steps of the process according to the present invention or directly to at least one of the reaction steps of the process according to the present invention, in particular the optional selective hydrogenation step a) and / or the hydroconversion step b) and / or the hydrotreating step e). Optionally, a portion of the recycle stream can be sent to the optional pretreatment step aO).

[0244] Preferably, at least a portion of the hydrotreated liquid hydrocarbon-based effluent obtained from separation step f) is fed to hydrotreating step e).

[0245] Advantageously, the amount of the recycle stream is adjusted such that the weight ratio between the recycle stream and the feedstock containing pyrolysis oil, i.e., the feedstock to be treated in the entire process, is less than or equal to 10, preferably less than or equal to 5, and preferably greater than or equal to 0.001, preferably greater than or equal to 0.01, and preferably greater than or equal to 0.1. Very preferably, the amount of the recycle stream is adjusted such that the weight ratio between the recycle stream and the feedstock containing pyrolysis oil is 0.2 - 5.

[0246] Depending on the feedstock being processed, a portion of the resulting product is recycled to at least one reaction step of the process according to the invention or upstream thereof, which advantageously allows first for dilution of impurities and second for control of the temperature in one or more reaction steps where the reactions involved can be highly exothermic.

[0247] According to a preferred embodiment of the invention, a process for treating a feedstock comprising pyrolysis oil comprises the following sequence of steps, preferably in a given order and preferably consisting of the following sequence of steps:

[0248] b) Hydroconversion,

[0249] c) Separation,

[0250] d) Fractionation,

[0251] e) Hydrotreating,

[0252] f) Separation,

[0253] to produce an effluent, at least a portion of which is suitable for treatment in a steam cracking unit.

[0254] According to a second preferred embodiment of the invention, a process for treating a feedstock comprising pyrolysis oil comprises the following sequence of steps, preferably in a given order and preferably consisting of the following sequence of steps:

[0255] b) Hydroconversion,

[0256] c) Separation,

[0257] d) Recycling at least a portion of the hydrocarbon fraction comprising compounds boiling above 385 °C to the fractionation in step b),

[0258] e) Hydrotreating,

[0259] f) Separation,

[0260] to produce an effluent, at least a portion of which is suitable for treatment in a steam cracking unit.

[0261] According to a third preferred embodiment of the invention, a process for treating a feedstock comprising pyrolysis oil comprises the following sequence of steps, preferably in a given order and preferably consisting of the following sequence of steps:

[0262] b) Hydroconversion,

[0263] c) Separation,

[0264] d) Recycling at least a portion of the hydrocarbon fraction comprising compounds boiling above 385 °C to the fractionation in step b),

[0265] e) Hydrotreating,

[0266] e') Hydrocracking,

[0267] f) Separation,

[0268] to produce an effluent, at least a portion of which is suitable for treatment in a steam cracking unit.

[0269] According to a fourth preferred embodiment of the present invention, a method for treating a feedstock comprising plastics and / or pyrolysis oil of SRF comprises the following sequence of steps, preferably in a given order, and preferably consisting of the following sequence of steps:

[0270] a) Selective hydrogenation,

[0271] b) Hydroconversion,

[0272] c) Separation,

[0273] d) Recycling at least a portion of the hydrocarbon fraction comprising compounds having a boiling point above 385 °C to the fractionation in step b),

[0274] e) Hydrotreating,

[0275] e') Hydrocracking,

[0276] f) Separation,

[0277] g) Recycling at least a portion of the hydrotreated liquid hydrocarbon-based effluent obtained from step f) to step a) and / or b) and / or e),

[0278] to produce an effluent, at least a portion of which is suitable for treatment in a steam cracking unit.

[0279] The hydrotreated liquid hydrocarbon-based effluent or a portion of the effluent thus obtained by treating pyrolysis oil by the method according to the invention has a composition compatible with the specifications of the feedstock entering the steam cracking unit. In particular, the composition of the hydrocarbon-based effluent or the one or more hydrocarbon-based streams is preferably such that:

[0280] - the total content of metal elements is less than or equal to 5.0 ppm by weight, preferably less than or equal to 2.0 ppm by weight, preferably less than or equal to 1.0 ppm by weight and preferably less than or equal to 0.5 ppm by weight, and:

[0281] - the content of iron (Fe) element is less than or equal to 100 ppb by weight,

[0282] - the content of silicon (Si) element is less than or equal to 1.0 ppm by weight, preferably less than or equal to 0.6 ppm by weight, and

[0283] - The sulfur content is less than or equal to 500 ppm by weight, preferably less than or equal to 200 ppm by weight.

[0284] - The nitrogen content is less than or equal to 100 ppm by weight, preferably less than or equal to 50 ppm by weight, preferably less than or equal to 5 ppm by weight.

[0285] - The total chlorine element content is less than or equal to 10 ppm by weight, preferably less than 1.0 ppm by weight.

[0286] - The asphaltene content is less than 5.0 ppm by weight.

[0287] - The content of olefin compounds (monoolefins and diolefins) is less than or equal to 5.0% by weight, preferably less than or equal to 2.0% by weight, preferably less than or equal to 0.1% by weight.

[0288] The content is given as relative weight concentration, weight percentage (%), parts per million by weight (ppm) or parts per billion by weight (ppb), relative to the total weight of the stream under consideration.

[0289] Thus, the process according to the invention can treat SRF and / or plastic pyrolysis oil to obtain an effluent that can be wholly or partly injected into a steam cracking unit.

[0290] Steam cracking step i) (optional)

[0291] The hydrotreated liquid hydrocarbon-based effluent obtained from step f) can be wholly or partly fed to steam cracking step h).

[0292] Advantageously, one or more gas fractions obtained from separation steps c) and / or f) and containing ethane, propane and butane can also be wholly or partly sent to steam cracking step h).

[0293] The steam cracking step h) is advantageously carried out in at least one pyrolysis furnace at a temperature of 700 - 900 °C, preferably 750 - 850 °C and at a relative pressure of 0.05 - 0.3 MPa. The residence time of the hydrocarbon-based compounds is generally less than or equal to 1.0 second (denoted as s), preferably 0.1 - 0.5 s. Advantageously, steam is introduced upstream of the optional steam cracking step h) and after separation (or fractionation). The amount of water introduced (advantageously in the form of steam) is advantageously 0.3 - 3.0 kg of water / kg of hydrocarbon-based compounds entering step h). The optional step h) is preferably carried out in parallel in a plurality of pyrolysis furnaces to adapt the operating conditions to the various streams fed to step h), and in particular the streams obtained from steps c) and / or f), and also to manage the pipe decoking time. The furnace comprises one or more pipes arranged in parallel. The furnace may also represent a set of furnaces operating in parallel. For example, the furnace may be dedicated to cracking a naphtha fraction containing compounds with a boiling point less than or equal to 175 °C.

[0294] The effluents from the various steam cracking furnaces are generally recombined before separation to form the effluent. It should be understood that the steam cracking step h) includes the steam cracking furnace, but also includes sub-steps related to steam cracking known to those skilled in the art. These sub-steps may particularly include heat exchangers, towers and catalytic reactors and recycling to the furnace. The tower generally makes it possible to fractionate the effluent to recover at least one light fraction containing hydrogen and compounds containing 2 - 5 carbon atoms, and a fraction containing pyrolysis gasoline, and optionally a fraction containing pyrolysis oil. The tower makes it possible to separate the various components of the fractionated light fraction to recover at least one fraction rich in ethylene (C2 fraction) and a fraction rich in propylene (C3 fraction) and optionally a fraction rich in butene (C4 fraction). The catalytic reactor particularly makes it possible to carry out selective hydrogenation of the C2, C3 or even C4 fractions and pyrolysis gasoline. Advantageously, saturated compounds, particularly saturated compounds containing 2 - 4 carbon atoms, are recycled to the steam cracking furnace to increase the total olefin yield.

[0295] The steam cracking step h) 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), the content of which is satisfactory, particularly relative to the weight of the steam cracking effluent considered, greater than or equal to 30% by weight, particularly greater than or equal to 40% by weight, or even greater than or equal to 50% by weight of the total olefins containing 2, 3 and 4 carbon atoms. The C2, C3 and C4 olefins can then be advantageously used as polyolefin monomers.

[0296] According to one or more preferred embodiments of the present invention, alone or in combination, the method for treating a raw material containing SRF and / or plastic pyrolysis oil comprises the above sequence of steps, preferably in a given order, and preferably consists of the above sequence of steps, namely:

[0297] b) Hydroconversion,

[0298] c) Separation,

[0299] d) Fractionation,

[0300] e) Hydrotreating,

[0301] f) Separation,

[0302] h) Steam cracking.

[0303] According to a preferred embodiment, the method for treating a feedstock comprising SRF and / or pyrolysis oil of plastics comprises the above sequence of steps, preferably in a given order, and preferably consisting of the above sequence of steps, namely::

[0304] a) Selective hydrogenation,

[0305] b) Hydroconversion,

[0306] c) Separation,

[0307] d) Recycling at least a part of the hydrocarbon fraction comprising compounds having a boiling point higher than 385 °C to the fractionation in step b),

[0308] e) Hydrotreating,

[0309] e′) Hydrocracking,

[0310] f) Separation,

[0311] h) Steam cracking of at least another part of the hydrotreated liquid hydrocarbon-based effluent obtained from step f).

[0312] Analysis methods used

[0313] Analysis methods and / or standards for determining the characteristics of the various streams, in particular the feedstock to be treated and the effluents, are known to those skilled in the art. They are listed specifically below for reference. Other recognized equivalent methods, in particular equivalent IP, EN or ISO methods, may also be used:

[0314] Table 1

[0315]

[0316] (1) The MAV method described in the article: C. López-García 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. BRIEF DESCRIPTION OF THE DRAWINGS

[0317] Information regarding Figure 1 the elements mentioned enables a better understanding of the present invention, which is not limited to the specific embodiments illustrated in the figures. The various embodiments presented can be used alone or in combination with each other without any limitation on such combination.

[0318] Figure 1 A flowchart representing a specific embodiment of the method of the present invention, including:

[0319] - Step a) of selectively hydrogenating a hydrocarbon-based feedstock obtained from the pyrolysis of plastic 1 in at least one fixed-bed reactor containing at least one selective hydrogenation catalyst in the presence of a hydrogen-rich gas 2 and optionally an amine supplied by stream 3 to obtain an effluent 4;

[0320] - Step b) of hydrotreating the effluent 4 obtained from step a) in at least one ebullated-bed, entrained-bed, and / or moving-bed reactor containing at least one hydroconversion catalyst in the presence of hydrogen 5 to obtain a hydrotreated effluent 6;

[0321] - Separation step c) of effluent 6 in the presence of an aqueous washing solution 7, enabling the obtention of at least one fraction 8 containing hydrogen, an aqueous fraction 9 containing dissolved salts, and a hydrocarbon-based liquid fraction 10;

[0322] - Fractionation step d) of the hydrocarbon-based liquid fraction 10, enabling the obtention of at least one gas fraction 11, a hydrocarbon fraction 12 containing compounds with a boiling point less than or equal to 385 °C, and a fraction 13 containing compounds with a boiling point greater than 385 °C, which is preferably at least partially recycled to step b);

[0323] - Hydrotreating at least a portion of the hydrocarbon fraction 12 obtained from step d), which contains compounds with a boiling point less than or equal to 385 °C obtained from step d), in at least one fixed-bed reactor containing at least one hydrocracking catalyst, in a fixed-bed reactor containing at least one hydrotreating catalyst to obtain a hydrotreated effluent 15;

[0324] Step f) of separating the effluent 15 makes it possible to obtain at least one fraction 16 containing hydrogen and a hydrotreated liquid hydrocarbon-based effluent 17.

[0325] At the end of step f), at least a portion of the hydrotreated liquid hydrocarbon 17 is sent to a steam cracking process (not shown).

[0326] Optionally, a portion of the hydrotreated liquid hydrocarbon-based effluent 17 forms recycle streams 17a, 17b, and 17c, which are fed to step a) and / or b) and / or e), respectively.

[0327] Figure 1 Only the main steps and the main streams are shown in order to better understand the present invention. It is clearly understood that all the equipment required to function (vessels, pumps, exchangers, furnaces, towers, etc.) are present, even if they are not shown. It should also be understood that, as described above, the hydrogen-rich gas stream (supply or recycle) can be injected into the inlet of each reactor or catalytic bed, or between two reactors or two catalytic beds. Methods known to those skilled in the art for purifying and recycling hydrogen can also be used. Detailed description

[0328] Example

[0329] Example 1 (according to the present invention)

[0330] The feedstock 1 processed in this method is SRF pyrolysis oil having the characteristics shown in Table 2.

[0331] Table 2: Characteristics of the feedstock

[0332]

[0333] Under the conditions shown in the table, in the presence of a NiMo-type hydrotreating catalyst on hydrogen 5 and alumina, the hydroconversion step b) of the feedstock 1 directly (without the selective hydrogenation step a)) in a ebullated bed was carried out under the conditions shown in Table 3.

[0334] Table 3: Conditions of the hydroconversion step b)

[0335]

[0336] The effluent 6 obtained from the hydroconversion step b) was sent to step c), and then to the fractionation step d). Table 4 gives the yields of the various fractions obtained at the end of the fractionation step d) relative to the feedstock 1 entering the process chain.

[0337] Table 4: Yields of the various products and fractions obtained at the end of step b)

[0338] <![CDATA[H2S+NH3]]> wt% 0.35 C1-C4 wt% 3.70 PI - 175°C fraction wt% 59.0 175°C - 385°C fraction wt% 35.0 385°C+ fraction wt% 3.0 Total wt% 101.05

[0339] Then, the liquid fractions (naphtha fraction and diesel fraction) containing compounds with a boiling point less than or equal to 385 °C are sent to the hydrotreating step e), and carried out under the conditions shown in Table 5 in the presence of hydrogen 2 and a NiMo-type selective hydrotreating catalyst on alumina.

[0340] Table 5: Conditions for the hydrotreating step b)

[0341]

[0342] The effluent 17 obtained from the hydrotreating step e) undergoes the separation and fractionation step f).

[0343] Table 6 gives the total yields of the various fractions obtained at the end of the separation and fractionation step f) (including the stripping column and the distillation column) relative to the feedstock 1 entering the process chain.

[0344] Table 6: Yields of the various products and fractions obtained at the end of step f)

[0345] <![CDATA[H2S+NH3]]> wt% 0.50 C1-C4 wt% 4.50 PI - 175°C fraction wt% 60.5 175°C - 385°C fraction wt% 32.5 385°C+ fraction wt% 2.5 Total wt% 100.50

[0346] The compounds H2S and NH3 are mainly removed in the form of salts in the aqueous phase removed in the separation step d).

[0347] The characteristics of the PI-175 °C and 175 °C - 385 °C liquid fractions obtained after the separation and fractionation step f) are shown in Table 7:

[0348] Table 7: Characteristics of the PI-175 °C and 175 °C - 385 °C fractions

[0349]

[0350]

[0351] Both the PI-175 °C and 175 °C - 385 °C liquid fractions have a composition compatible with the steam cracking unit because:

[0352] - Their chlorine element content is very low (undetectable content and 25 ppb by weight respectively), lower than the limit required for steam cracking feedstock;

[0353] - The metal content, especially the content of iron (Fe), is also very low (the metal content of the PI-175 °C fraction was not detected, and the metal content of the 175 °C - 385 °C fraction < 1 ppm; the content of Fe in the PI-175 °C fraction was not detected and 25 ppb (by weight) in the 175 °C - 385 °C fraction, which is lower than the limit required for steam cracking feedstock (≤ 5.0 ppm by weight, very preferably the metal ≤ 1 ppm (by weight); Fe ≤ 100 ppb (by weight));

[0354] - Finally, they contain sulfur (less than 2 ppm by weight for the PI-175 °C fraction and less than 2 ppm by weight for the 175 °C - 385 °C fraction) and nitrogen (less than 5 ppm by weight for the PI-175 fraction and < 10 ppm by weight for the 175 °C - 385 °C fraction), and their contents are much lower than the limits required for steam cracking feedstock (≤ 500 ppm by weight, preferably ≤ 200 ppm S and N by weight).

[0355] Therefore, the obtained PI-175 °C and 175 °C - 385 °C liquid fractions are then sent to the steam cracking step h) (see Table 8).

[0356] Table 8: Conditions of the steam cracking step

[0357] Unit PI - 175°C fraction 175°C - 385°C+ fraction Furnace outlet pressure Absolute pressure 0.2 0.2 Furnace outlet temperature °C 835 820 Steam / feed ratio kg / kg 0.6 0.8 Residence time in furnace s 0.25 0.2

[0358] The effluents from various steam crackers go through a separation step, recycling the saturated compounds into the steam crackers, and producing the yields shown in Table 9 (yield = mass percentage of the product relative to the mass of the PI-175 °C and 175 °C - 385 °C fractions in the steps upstream of the steam cracking step, expressed in weight %).

[0359] Table 9: Yields of the steam cracking step

[0360]

[0361]

[0362] Considering the yields obtained during the pyrolysis oil treatment of the PI-175 °C and 175 °C - 385 °C liquid fractions at the outlet of the hydroconversion and hydrotreating steps (see Table 6), the overall total yield of the raw material 1 entering the process chain relative to the product obtained from the steam cracking step h) can be determined with respect to the initial raw material of the SRF pyrolysis oil type introduced in step a):

[0363] Table 10: Yields of the products of the steam cracking step for the PI-175 °C fraction and 175 °C - 385 °C fraction

[0364] <![CDATA[H2S+NH3]]> wt% 0.50 Hydrogen, carbon monoxide, chlorine wt% 16.0 C2 wt% 0.6 C3 wt% 1.7 C4 wt% 1.8 Ethylene wt% 28.7 Propylene wt% 15.1 C4 cut wt% 8.4 Cracked gasoline wt% 16.7 Cracked oil wt% 9.5 385°C+ fraction wt% 2.5 Total wt% 101.50

[0365] When fractions in the range of PI - 175 °C and 175 - 385 °C are sent to the steam cracking unit, the method according to the invention can achieve total mass yields of ethylene and propylene of 28.7% and 15.1% respectively, relative to the mass of the initial feedstock of the pyrolysis oil type.

[0366] Furthermore, the specific sequence of steps upstream of the steam cracking step makes it possible to limit coke formation and avoid corrosion problems that would occur if chlorine were not removed.

[0367] Example 2 (according to the invention)

[0368] The feedstock 1 processed in this process is a plastic pyrolysis oil having the characteristics shown in Table 11.

[0369] Table 11: Feedstock characteristics

[0370]

[0371]

[0372] Under the conditions shown in Table 12, in a fixed - bed reactor, in the presence of hydrogen 2 and a NiMo - type selective hydrogenation catalyst on alumina, feedstock 1 is subjected to the selective hydrogenation step a).

[0373] Table 12: Conditions for the selective hydrogenation step a)

[0374]

[0375] At the end of the selective hydrogenation step a), the diolefin content in the feedstock is significantly reduced.

[0376] The effluent 4 obtained from the selective hydrogenation step a) is directly subjected to the hydroconversion step b) without separation. This hydroconversion step b) is carried out in a fluidized - bed in the presence of hydrogen 5 and a NiMo - type hydrogenation catalyst supported on alumina under the conditions provided in Table 13.

[0377] Table 13: Conditions for the hydroconversion step b)

[0378] Hydroconversion temperature °C 380 Hydrogen partial pressure Absolute pressure 9.0 <![CDATA[H2 / HC (Volume coverage rate of hydrogen relative to the volume of the raw material)]]> <![CDATA[cubic meter 3 / m 3 > 300 HSV (feed volume flow rate / catalyst volume) for step b <![CDATA[h -1 > 1.5

[0379] The effluent 6 obtained from the hydroconversion step b) is sent to the separation step c) and then to the fractionation step d). Table 14 gives the yields of the various fractions obtained at the end of the fractionation step d) relative to the feedstock 1 entering the process chain.

[0380] Table 14: Yields of the various products and fractions obtained at the outlet of the fractionation step d)

[0381] <![CDATA[H2S+NH3]]> wt% 0.4 C1-C4 wt% 1.0 PI - 150°C fraction wt% 28.4 150°C+ fraction wt% 70.9 Total wt% 100.7

[0382] Then the liquid fractions (naphtha fraction PI - 150°C and gas oil fraction 150°C+) containing compounds with a boiling point less than or equal to 385°C are sent to the hydrotreating step e), under the conditions shown in Table 15, in the presence of hydrogen and a hydrotreating catalyst of the NiMo - supported alumina type.

[0383] Table 15: Conditions of the hydrotreating step e)

[0384] Hydrotreating temperature °C 350 Hydrogen partial pressure Absolute pressure 9.0 <![CDATA[H2 / HC (Volume coverage rate of hydrogen relative to the volume of the raw material)]]> <![CDATA[cubic meter 3 / m 3 > 300 HSV (feed volume flow rate / catalyst volume flow rate) <![CDATA[h -1 > One

[0385] The effluent 17 obtained at the end of the hydrotreating step e) undergoes the separation and fractionation step f).

[0386] Table 16 gives the total yields of the various fractions obtained at the end of the separation and fractionation step f) (including the stripping column and the distillation column) relative to the feedstock 1 entering the process chain.

[0387] Table 16: Yields of the various products and fractions obtained at the outlet of the separation and fractionation step f)

[0388]

[0389]

[0390] The compounds H2S and NH3 are removed mainly in the aqueous phase removed in the separation step d) in the form of salts.

[0391] The characteristics of the PI - 150°C and 150°C+ liquid fractions obtained after the separation and fractionation step f) are shown in Table 17:

[0392] Table 17: Characteristics of the PI - 150°C and 150°C+ fractions after the separation and fractionation step f)

[0393] PI - 150°C fraction 150°C+ fraction Density at 15°C (ASTM D4052) <![CDATA[g / cm 3 > 0.750 0.820 Content: Sulfur (ASTM D5453) wt ppm ＜2 ＜2 Nitrogen (ASTM D4629) wt ppm ＜5 ＜10 Iron (ASTM D5185) ppb wt Not detected ＜50 Total metals (ASTM D5185) wt ppm Not detected ＜1 Chlorine (ASTM D7536) ppb wt Not detected ＜25 Paraffins (UOP990-11) wt% 75 70 Naphthenes (UOP990-11) wt% 25 28 Olefins (UOP990-11) wt% Not detected Not detected Aromatics (UOP990-11) wt% ＜1 Two Simulated distillation (ASTM D2887), in % 0 ℃ 25 140 5 ℃ 32 162 10 ℃ 40 174 30 ℃ 82 226 50 ℃ 108 281 70 ℃ 126 346 90 ℃ 142 395 95 ℃ 146 404 100 ℃ 160 425

[0394] Both the liquid fractions PI - 150°C and 150°C+ have a composition compatible with the steam cracking unit because:

[0395] - They do not contain any olefins (mono - olefins and di - olefins);

[0396] - They have a very low chlorine element content (non - detectable content and a content of 25 weight ppb respectively) below the limit values required for the steam cracking feedstock;

[0397] - The metal content, especially the iron (Fe) content, is also very low (no metal content is detected in the PI - 150 °C fraction, and < 1 weight ppm in the 150 °C+ fraction; no Fe content is detected in the PI - 150 °C fraction, and < 50 weight ppb in the 150 °C+ fraction), which is lower than the limit values required for steam cracking feedstocks (metal ≤ 5.0 weight ppm, very preferably ≤ 1 weight ppm; Fe ≤ 100 weight ppb);

[0398] - Finally, they contain sulfur (< 2 weight ppm for the PI - 150 °C fraction, < 2 weight ppm for the 150 °C+ fraction) and nitrogen (< 0.5 weight ppm for the PI - 150 °C fraction, < 3 weight ppm for the 150 °C+ fraction), and their contents are much lower than the limit values required for steam cracking feedstocks (for S and N ≤ 500 weight ppm, preferably ≤ 200 weight ppm).

[0399] The obtained PI - 150 °C and 150 °C+ liquid fractions are then advantageously fed to the steam cracking step h).

Claims

1. A method for processing a feedstock containing solid recovered fuel and / or pyrolysis oil of plastics, comprising: a) Optionally, a selective hydrogenation step, which is carried out in a reaction section fed at least with the feedstock and a gas stream containing hydrogen, in the presence of at least one selective hydrogenation catalyst, at a temperature of 100 - 280 °C, at a hydrogen partial pressure of 1.0 - 20.0 MPa absolute pressure and a space velocity of 0.3 - 10.0 h -1 to obtain a hydrogenation effluent; b) A hydroconversion step, in a hydroconversion reaction zone, using at least one ebullated bed reactor, entrained bed reactor or moving bed reactor, comprising at least one hydroconversion catalyst, feeding at least the feedstock to the hydroconversion reaction zone, or at least feeding a hydrotreated effluent obtained at the end of step a) and a gas stream containing hydrogen, the hydroconversion reaction zone operating at a temperature of 250 - 450 °C, a hydrogen partial pressure of 1.0 - 20.0 MPa absolute pressure and a space velocity of 0.05 - 10.0 h -1 to obtain a hydroconversion effluent; c) A separation step, in which the hydroconversion effluent and an aqueous solution obtained from step b) are fed, and the step is carried out at a temperature of 50 - 450 °C to obtain at least one gaseous effluent, an aqueous effluent, and a hydrocarbon effluent; d) A fractionation step, in which all or part of the hydrocarbon effluent obtained from step c) is fractionated to obtain at least one gas stream, a hydrocarbon fraction containing compounds with a boiling point less than or equal to 385 °C, and a hydrocarbon fraction containing compounds with a boiling point higher than 385 °C; e) A hydrotreating step, in which in a hydrotreating reaction section, at least one fixed-bed reactor comprising n catalytic beds is used, where n is an integer greater than or equal to 1, each catalytic bed contains at least one hydrotreating catalyst, the hydrotreating reaction section is fed with at least some hydrocarbon fractions, the hydrocarbon fractions contain compounds with a boiling point less than or equal to 385 °C obtained from step d), and a gas stream containing hydrogen, the hydrotreating reaction section operates at a temperature of 250 - 430 °C, a hydrogen partial pressure of 1.0 - 20.0 MPa absolute pressure, and a space velocity of 0.1 - 10.0 h -1 to obtain a hydrotreated effluent; f) A separation step, in which the hydrotreated effluent obtained from step e) is fed to obtain at least a gaseous effluent and a hydrotreated liquid hydrocarbon effluent.

2. The method according to claim 1, including the selective hydrogenation step a).

3. The method according to any one of claims 1 - 2, wherein at least part of the hydrocarbon fraction containing compounds with a boiling point higher than 385 °C obtained from step d) is recycled to step b).

4. The method according to any one of claims 1 - 2, including a pretreatment step a0) of the feedstock, the pretreatment step being carried out upstream of the optional selective hydrogenation step a) or upstream of the hydroconversion step b), and including a filtration step and / or a water washing step and / or an adsorption step.

5. The method according to any one of claims 1 - 2, wherein the hydrotreated liquid hydrocarbon effluent obtained from step f) is fed to a steam cracking step h) carried out in at least one pyrolysis furnace at a temperature between 700 and 900 °C and a relative pressure between 0.05 and 0.3 MPa.

6. The method according to any one of claims 1 - 2, further including a recycling step g), in which a part of the hydrotreated liquid hydrocarbon effluent obtained from the separation step f) is fed to the optional selective hydrogenation step a) and / or the hydroconversion step b) and / or the hydrotreating step e).

7. The method according to any one of claims 1 - 2, wherein the separation step f) includes fractionation such that in addition to the gas stream, a naphtha fraction containing compounds with a boiling point less than or equal to 175 °C and a diesel fraction containing compounds with a boiling point higher than 175 °C and lower than 385 °C are obtained.

8. The method according to any one of claims 1-2, further comprising a hydrocracking step e') carried out in the hydrocracking reaction section, using at least one fixed bed comprising n catalytic beds, where n is an integer greater than or equal to 1, each comprising: At least one hydrocracking catalyst, wherein the hydrocracking reaction section is fed at least with the hydrotreated effluent obtained from step e) and / or the diesel fraction obtained from step f) comprising compounds having a boiling point higher than 175 °C and lower than 385 °C, and a gas stream comprising hydrogen, and the hydrocracking reaction section operates at a temperature of 250 - 450 °C, a hydrogen partial pressure of 1.5 - 20.0 MPa absolute pressure and a space velocity of 0.1 - 10.0 h -1 to obtain a hydrocracking effluent, which is fed to separation step f).

9. The method according to claim 9, wherein the naphtha fraction containing compounds with a boiling point less than or equal to 175 °C is fractionated into a light naphtha fraction containing compounds with a boiling point less than 80 °C and a heavy naphtha fraction containing compounds with a boiling point of 80 to 175 °C.

10. The method according to claim 9, wherein at least part of the heavy naphtha fraction is sent to an aromatics complex including at least one naphtha reforming step and / or wherein at least part of the light naphtha fraction is sent to the steam cracking step h).

11. The method according to any one of claims 1 - 2, wherein the selective hydrogenation catalyst in step a) comprises a support selected from alumina, silica, silica - alumina, magnesia, clay, and mixtures thereof, and a hydrogenation - dehydrogenation function comprising at least one Group VIII element and at least one Group VIB element, or at least one Group VIII element.

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

13. The method according to any one of claims 1 - 2, wherein the hydrotreating catalyst in step e) comprises a support selected from alumina, silica, silica - alumina, magnesia, clay, and mixtures thereof, and a hydrogenation - dehydrogenation function comprising at least one Group VIII element and / or at least one Group VIB element.

14. The method according to claim 8, wherein the hydrocracking catalyst in step e') comprises a support selected from halogenated alumina, a combination of boron and aluminum oxide, amorphous silica - alumina, and zeolite, and a hydrogenation - dehydrogenation function comprising at least one Group VIB metal selected from chromium, molybdenum, and tungsten, alone or as a mixture, and / or at least one Group VIII metal selected from iron, cobalt, nickel, ruthenium, rhodium, palladium, and platinum.

15. The method according to claim 1, wherein the feedstock has the following properties: - 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 metal elements is between 10 and 10000 ppm by weight, - The content of iron elements is between 0 and 100 ppm by weight, - The content of silicon elements is between 0 and 1000 ppm by weight.

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