EP4419627A1

EP4419627A1 - Method for processing pyrolysis oils from plastics and/or solid recovered fuels, loaded with impurities

Info

Publication number: EP4419627A1
Application number: EP22802907.0A
Authority: EP
Inventors: Marisa DE SOUSA DUARTE; Wilfried Weiss; Duc NGUYEN-HONG
Original assignee: IFP Energies Nouvelles IFPEN
Current assignee: IFP Energies Nouvelles IFPEN
Priority date: 2021-10-19
Filing date: 2022-10-10
Publication date: 2024-08-28
Also published as: FR3128120A1

Abstract

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

Description

METHOD FOR TREATMENT OF PYROLYSIS OILS FROM PLASTICS AND/OR SOLID RECOVERY FUELS LOADED WITH IMPURITIES

TECHNICAL AREA

The present invention relates to a process for treating an oil from the pyrolysis of plastics and/or solid recovered fuels (SRC), loaded with impurities in order to obtain a hydrocarbon effluent which can be recovered by being at least partly directly integrated to a naphtha or diesel pool or as feed to a steam cracker. More particularly, the present invention relates to a process for treating a charge resulting from the pyrolysis of plastic waste and/or CSR, in order to eliminate at least part of the impurities that said charge may contain in large quantities, and in a to hydrogenate the charge in order to be able to recover it.

PRIOR TECHNIQUE

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

Solid recovered fuels (CSR), also called "refuses derived fuel" or RDF according to the Anglo-Saxon terminology, are solid non-hazardous waste prepared for energy recovery, whether they come from household and similar waste, waste from economic activities or construction and demolition waste. CSR is generally a mixture of any combustible waste such as used tires, food by-products (fats, animal meal, etc.), viscose and wood waste, light fractions from shredders (for example of used vehicles, electrical and electronic equipment (WEEE), household and commercial waste, residues from the recycling of various types of waste, including certain municipal waste, plastic waste, textiles, wood among others. can also be made up of just one of the wastes mentioned above, for example used tires. CSR generally contains plastic waste. Today, CSR is mainly recovered as energy. They can be directly used as substitutes for fuels. fossils in co-incineration facilities (coal and lignite thermal power plants, cement works, lime kilns) or in household waste incineration units, or indirectly in pyrolysis units dedicated to energy recovery: pyrolysis oils CSR are thus generally burned to generate electricity, or even used as fuel in industrial boilers or district heating. Another way of recovering plastic or CSR pyrolysis oils is to be able to use these pyrolysis oils as feedstock for a steam cracking unit in order to (re)create olefins, the latter being constituent monomers of certain polymers . However, plastic waste or CSR are generally mixtures of several polymers, for example mixtures of polyethylene, polypropylene, polyethylene terephthalate, polyvinyl chloride, polystyrene. In addition, depending on the uses, plastics can contain, in addition to polymers, other compounds, such as plasticizers, pigments, dyes or residues of polymerization catalysts, as well as other very varied impurities, organic and mineral materials from sorting center separation operations, an operation whose selectivity may not be total. The oils resulting from the pyrolysis of plastics or CSR thus contain many impurities, in particular diolefins, metals, silicon, or even halogenated compounds, in particular chlorine-based compounds, heteroelements such as sulphur, oxygen and nitrogen, insolubles, at levels that are often high and incompatible with steam cracking units or units located downstream of steam cracking units, in particular polymerization processes and selective hydrogenation processes. These impurities can generate problems of operability and in particular problems of corrosion, coking or catalytic deactivation, or even problems of incompatibility in the uses of the target polymers. The presence of diolefins very often leads to problems of instability of the pyrolysis oil, characterized by the formation of gums. The gums and insolubles that may be present in the pyrolysis oil can cause clogging problems in the processes.

In addition, during the steam cracking step, the yields of light olefins sought after for petrochemicals, in particular ethylene and propylene, depend very heavily on the quality of the feeds sent to the steam cracking. The BMCI index (Bureau of Mines Correlation Index according to the Anglo-Saxon terminology) is often used to characterize hydrocarbon cuts. This index, developed for hydrocarbon products derived from crude oils, is calculated from the measurement of the density and the average boiling temperature: it is equal to 0 for a linear paraffin and 100 for benzene. Its value is therefore all the higher when the product analyzed has an aromatic condensed structure, naphthenes having a BMCI intermediate between paraffins and aromatics.

Overall, the yields of light olefins increase when the paraffin content increases and therefore when the BMCI decreases. Conversely, the yields of unwanted heavy compounds and/or coke increase when the BMCI increases.

Document WO 2018/055555 proposes an overall, very general and relatively complex plastic waste recycling process, ranging from the very step of pyrolysis of plastic waste to the steam cracking stage. The process comprises, among other things, a step of hydrotreating the liquid phase resulting directly from the pyrolysis, preferably under fairly stringent conditions, in particular in terms of temperature, for example at a temperature of between 260 and 300° C., a step separation of the hydrotreatment effluent followed by a stage of hydrodealkylation of the heavy effluent separated at a temperature which is preferably high, for example between 260 and 400°C.

Due to the impurity content of pyrolysis oils, especially when they are heavily loaded with impurities, one can observe a deactivation of the catalysts of the hydrotreating unit which is operated in a fixed bed, which reduces the cycle time. Indeed, the main constraint of fixed bed units is the fact of having to shut down the unit to replace the catalysts. In addition, pyrolysis oils, especially those heavily loaded with impurities, can create clogging problems especially in preheating furnaces, charge/effluent exchangers or on the bed heads of catalytic reactors.

It would therefore be advantageous to propose a process for treating pyrolysis oils having long-lasting catalytic cycles by allowing the replacement of the catalysts without shutting down the unit, while producing a cut rich in alkanes which can be easily upgraded in a steam cracking unit.

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

Unpublished patent application FR 20/09.750 describes such a method for treating an oil from the pyrolysis of plastics and/or CSR comprising in particular: a) optionally a stage of selective hydrogenation of said feedstock in the presence of hydrogen and a selective hydrogenation catalyst to obtain a hydrogenated effluent; b) a hydroconversion step implementing at least one bubbling bed, entrained bed and/or moving bed reactor, comprising at least one hydroconversion catalyst, said hydroconversion reaction section being fed at least by said feed or by said hydrogenated effluent from step a) and a gas stream comprising hydrogen, to obtain a hydroconverted effluent; c) a separation stage, supplied with the hydroconverted effluent from stage b) and an aqueous solution, said stage being carried out at a temperature between 50 and 450° C., to obtain at least one gaseous effluent, an aqueous effluent and a hydrocarbon effluent; d) a step of fractionating all or part of the hydrocarbon effluent from step c), to obtain at least one gas stream, a hydrocarbon cut comprising compounds having a boiling point less than or equal to 385°C and a hydrocarbon cut comprising compounds having a boiling point greater than 385°C, e) a hydrotreatment step implementing at least one fixed-bed reactor comprising at least one hydrotreatment catalyst, said reaction section of hydrotreatment being supplied with at least a portion of said hydrocarbon cut comprising compounds having a boiling point less than or equal to 385°C from step d) and a gas stream comprising hydrogen, to obtain a hydrotreated effluent ; f) a separation step, supplied with the hydrotreated effluent from step e) to obtain at least one gaseous effluent and one hydrotreated liquid hydrocarbon effluent.

The unpublished patent application FR 21/04.873, which is based on the process of FR 20/09.750, describes another process for treating an oil from the pyrolysis of plastics and/or CSR in which the hydroconversion step involving implements at least one bubbling bed, entrained bed and/or moving bed reactor is followed by a hydrotreatment step implementing at least one fixed bed reactor without an intermediate separation step between the hydroconversion step and the hydrotreating step.

Research work has led the applicant to discover that, surprisingly, a simplification of existing processes is possible by eliminating the hydrotreatment step after the hydroconversion step. By applying more severe operating conditions and/or by choosing very active catalysts in the hydroconversion stage, it is possible to obtain a pyrolysis oil which can be directly upgraded by incorporating it into a fuel pool and/or which is directly compatible with treatment in a steam cracking unit without the need to carry out a hydrotreatment step after the hydroconversion. Indeed, by choosing the operating conditions and/or suitable catalysts, the hydrotreatment reactions, in particular hydrodenitrogenation, are sufficiently carried out in the hydroconversion stage. SUMMARY OF THE INVENTION

The invention relates to a process for treating a charge comprising an oil from the pyrolysis of plastics and/or solid recovered fuels comprising, preferably in the order given: a) optionally, a stage of selective hydrogenation implemented in a reaction section supplied at least with said charge and a gas stream comprising hydrogen, in the presence of at least one selective hydrogenation catalyst, at a temperature between 100 and 280°C, a partial pressure of hydrogen between 1.0 and 20.0 MPa abs. and an hourly volume rate between 0.3 and 10.0 h ^-1 , to obtain a hydrogenated effluent; b) a hydroconversion step implemented in a hydroconversion reaction section, implementing at least one bubbling bed, entrained bed and/or moving bed reactor, comprising at least one hydroconversion catalyst, said section hydroconversion reaction section being fed at least by said feed or by said hydrogenated effluent from step a) and a gas stream comprising hydrogen, said hydroconversion reaction section being implemented at a temperature between 300 and 450 ° C, a partial pressure of hydrogen between 5.0 and 20.0 MPa abs and an hourly volume rate between 0.03 and 2.0 h ^-1 , to obtain a hydroconverted effluent; c) a separation stage, supplied with the hydroconverted effluent from stage b) and an aqueous solution, said stage being carried out at a temperature between 20 and 450° C., to obtain at least one gaseous effluent, an aqueous effluent and a hydrocarbon effluent, d) optionally a step of fractionating all or part of the hydrocarbon effluent from step c), to obtain at least one gaseous effluent and at least at least one hydrocarbon cut comprising compounds having a point boiling point less than or equal to 150°C and a hydrocarbon cut comprising compounds having a boiling point greater than 150°C.

In the rest of the text, the term "pyrolysis oil" means an oil resulting from the pyrolysis of plastics and/or CSR, unless otherwise indicated.

An advantage of the process according to the invention is to purify a pyrolysis oil of at least some of its impurities, which makes it possible to hydrogenate it and thus to be able to enhance it, in particular by incorporating it directly into a fuel pool and/ or else by making it compatible with a treatment in a steam cracking unit in order to be able to obtain in particular light olefins which can be used as monomers in the manufacture of polymers. Another advantage of the invention is to prevent risks of clogging and/or corrosion of the processing unit in which the method of the invention is implemented, the risks being exacerbated by the presence, often in large quantities , diolefins, metals and halogenated compounds in the pyrolysis oil.

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

Performing a hydroconversion step using a system for adding fresh catalyst and withdrawing used catalyst without stopping the unit makes it possible in particular to treat pyrolysis oils heavily loaded with impurities.

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

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

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

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

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

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

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

According to a variant, the method further comprises a hydrotreatment step, said hydrotreatment step being carried out before or after step c) of separation, or even after step d) of fractionation, said hydrotreatment step being implemented in a hydrotreating reaction section, implementing at least one fixed bed reactor having n catalytic beds, n being an integer greater than or equal to 1, each comprising at least one hydrotreating catalyst, said reaction section hydrotreatment being supplied with at least part of said hydroconverted effluent from step b), or at least part of said hydrocarbon effluent from step c) or at least part of said hydrocarbon cut comprising compounds having a boiling point above 150°C from step d) and a gas stream comprising hydrogen, said hydrotreating reaction section being implemented at a temperature between 250 and 430°C, a pressure partial hydrogen between 1.0 and 20.0 MPa abs. and an hourly volume rate between 0.1 and 10.0 h ^-1 , to obtain a hydrotreated effluent.

According to this variant, said hydrotreating catalyst comprises a support chosen from the group consisting of alumina, silica, silica-aluminas, magnesia, clays and their mixtures, and a hydro-dehydrogenating function comprising at least one element from group VIII and/or at least one element from group VIB.

According to one variant, the process further comprises a hydrocracking step, said hydrocracking step being carried out either after a hydrotreating step, or after fractionation step d), said hydrocracking step being implemented in a hydrocracking reaction section, implementing at least one fixed bed having n catalytic beds, n being an integer greater than or equal to 1, each comprising at least one hydrocracking catalyst, said hydrocracking reaction section being fed by at least a portion of said hydrotreated effluent and/or by the hydrocarbon fraction comprising compounds having a boiling point above 150° C. resulting from stage d) and a gas stream comprising hydrogen, said reaction section of hydrocracking being implemented at an average temperature between 250 and 450° C., a partial pressure of hydrogen between 1.5 and 20.0 MPa abs. and an hourly volumetric speed between 0.1 and 10.0 IT ¹ , to obtain a hydrocracked effluent.

According to this variant, the process further comprises a second hydrocracking step implemented in a hydrocracking reaction section, implementing at least one fixed bed having n catalytic beds, n being an integer greater than or equal to 1, each comprising at least one hydrocracking catalyst, said hydrocracking reaction section being fed with a hydrocarbon cut comprising compounds having a boiling point above 150°C from the first hydrocracking stage and a gas stream comprising hydrogen, said hydrocracking reaction section being implemented at a temperature between 250 and 450° C., a partial pressure of hydrogen between 1.5 and 20.0 MPa abs. and an hourly volumetric speed between 0.1 and 10.0 IT ¹ , to obtain a hydrocracked effluent.

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

According to a variant, the method comprises said stage a) of selective hydrogenation.

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

According to a variant, the filler has the following properties:

- an aromatic content of between 0 and 90% by weight,

- a halogen content of between 2 and 5000 ppm by weight,

- a content of metallic elements between 10 and 10,000 ppm by weight,

- including an iron element content of between 0 and 100 ppm by weight,

- a content of silicon element between 0 and 1000 ppm by weight,

- a content of heteroelements provided by sulfur compounds, oxygenated compounds and/or nitrogen compounds of between 0 and 20,000 ppm by weight.

The invention also relates to the product capable of being obtained by the treatment process according to the invention.

According to a variant, the product comprises with respect to the total weight of the product:

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

- of which an iron element content less than or equal to 200 ppb by weight,

- a content of silicon element less than or equal to 5.0 ppm by weight,

- a sulfur content less than or equal to 500 ppm by weight,

- a nitrogen content less than or equal to 50 ppm by weight,

- a content of chlorine element less than or equal to 10 ppm by weight.

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

According to the present invention, the expressions "between .... and ..." and "between .... and ..." are equivalent and mean that the limit values of the interval are included in the range of values described . If this was not the case and the limit values were not included in the range described, such precision will be provided by the present invention.

Within the meaning of the present invention, the various ranges of parameters for a given stage such as the pressure ranges and the temperature ranges can be used alone or in combination. For example, within the meaning of the present invention, a range of preferred pressure values can be combined with a range of more preferred temperature values.

In the following, particular and/or preferred embodiments of the invention can be described. They may be implemented separately or combined with each other, without limitation of combination when technically feasible. In the following, the groups of chemical elements are given according to the CAS classification (CRC Handbook of Chemistry and Physics, publisher CRC press, editor-in-chief DR Lide, ^81st edition, 2000-2001). For example, group VIII according to the CAS classification corresponds to the metals of columns 8, 9 and 10 according to the new IUPAC classification.

The metal content is measured by X-ray fluorescence.

LIST OF FIGURES

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

DETAILED DESCRIPTION

Load

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

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 , preferably between 0.75 and 0.95 g/cm ³ .

The pyrolysis oil can also comprise, and most often comprises, impurities such as metals, in particular iron, silicon, halogenated compounds, in particular chlorinated compounds. These impurities may be present in the pyrolysis oil at high levels, for example up to 500 ppm weight or even 1000 ppm weight or even 5000 ppm weight of halogen elements provided by halogenated compounds, and up to 2500 ppm weight , or even 10,000 ppm by weight of metallic or semi-metallic elements. THE alkali metals, alkaline earths, transition metals, poor metals and metalloids can be assimilated to contaminants of a metallic nature, called metals or metallic or semi-metallic elements. The pyrolysis oil can comprise up to 200 ppm by weight or even 1000 ppm by weight of silicon, and up to 15 ppm by weight or even 100 ppm by weight of iron. The pyrolysis oil may also include other impurities such as heteroelements provided in particular by sulfur compounds, oxygenated compounds and/or nitrogen compounds, at levels generally below 20,000 ppm by weight of heteroelements and preferably below 10,000 ppm weight of heteroelements.

The method according to the invention is particularly well suited for treating a pyrolysis oil loaded with impurities. By this is meant a filler having the following properties:

- an aromatic content of between 0 and 90% by weight, often between 20 and 90% by weight, and possibly between 50 and 90% by weight;

- a halogen content of between 2 and 5000 ppm by weight, often between 200 and 5000 ppm by weight, and possibly between 500 and 5000 ppm by weight;

- a content of metallic elements between 10 and 10,000 ppm by weight, often between 2,000 and 10,000 ppm by weight, and possibly between 2,250 and 5,000 ppm by weight;

- including an iron element content between 0 and 100 ppm by weight, often between 10 and 100 ppm by weight, and possibly between 15 and 100 ppm by weight;

- a silicon element content of between 0 and 1000 ppm by weight, often between 100 and 1000 ppm by weight, and possibly between 200 and 1000 ppm by weight

- a content of heteroelements provided in particular by sulfur compounds, oxygenated compounds and/or nitrogen compounds of between 0 and 20,000 ppm by weight, and often be between 1,000 and 10,000 ppm by weight.

The process according to the invention is particularly well suited for treating a pyrolysis oil heavily loaded with impurities. By this is meant a filler having the following properties:

- an aromatic content of between 30 and 70% by weight;

- a halogen content of between 500 and 5000 ppm by weight;

- a content of metallic elements of between 300 and 5000 ppm by weight;

- including an iron element content of between 15 and 100 ppm by weight;

- a content of silicon element between 200 and 1000 ppm by weight;

- a content of heteroelements provided in particular by sulfur compounds, oxygenated compounds and/or nitrogen compounds of between 1000 and 10000 ppm by weight. The charge of the process according to the invention comprises at least one oil for the pyrolysis of plastics and/or CSR. Said charge may consist solely of plastics pyrolysis oil(s) or solely of CSR pyrolysis oil(s) or solely of a mixture of plastics pyrolysis oil(s) and CSR. Preferably, said filler comprises at least 50% by weight, preferably between 50 and 100% by weight, and particularly preferably between 75 and 100% by weight of plastic pyrolysis oil and/or CSR.

Plastics and/or CSR pyrolysis oil can come from a thermal or catalytic pyrolysis treatment or even be prepared by hydropyrolysis (pyrolysis in the presence of a catalyst and hydrogen).

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

The conventional petroleum feed can advantageously be a cut or a mixture of naphtha, vacuum gas oil, atmospheric residue or vacuum residue type cuts.

The feed resulting from the conversion of the biomass can advantageously be chosen from vegetable oils, algae or algal oils, fish oils, used food oils, and fats of vegetable or animal origin; or mixtures of such fillers. Said vegetable oils can advantageously be raw or refined, totally or partly, and derived from plants chosen from rapeseed, sunflower, soy, palm, olive, coconut, copra, castor, cotton , peanut, linseed and crambe oils and all oils derived, for example, from sunflower or rapeseed by genetic modification or hybridization, this list not being exhaustive. Said animal fats are advantageously chosen from lard and fats composed of residues from the food industry or from catering industries. Frying oils, various animal oils such as fish oils, tallow, lard can also be used.

The feed resulting from the conversion of the biomass can also be chosen from feeds resulting from thermal or catalytic conversion processes of biomass and/or organic waste, such as oils which are produced from biomass, in particular from lignocellulosic biomass, with various liquefaction methods, such as hydrothermal liquefaction or pyrolysis. The term “biomass” refers to material derived from recently living organisms, which includes plants, animals and their by-products. The term “lignocellulosic biomass” refers to biomass derived from plants or their by-products. Lignocellulosic biomass is composed of carbohydrate polymers (cellulose, hemicellulose) and an aromatic polymer (lignin).

The feed resulting from the conversion of the biomass can also advantageously be chosen from feeds resulting from the paper industry.

Pretreatment (optional)

Said feed comprising a pyrolysis oil can advantageously be pretreated in an optional pretreatment step aO), prior to step a) of optional selective hydrogenation or to step b) of hydroconversion when step a) does not is not present, to obtain a pretreated feed which feeds step a) or step b).

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

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

Said optional pretreatment step aO) is advantageously carried out at a temperature between 0 and 150° C., preferably between 5 and 100° C., and at a pressure between 0.15 and 10.0 MPa abs, preferably between 0 .2 and 1.0 MPa abs.

According to a variant, said optional pretreatment step aO) is implemented in an adsorption section operated in the presence of at least one adsorbent, preferably of the alumina type, having a specific surface greater than or equal to 100 m ² /g , preferably greater than or equal to 200 m ² /g. The specific surface of said at least one adsorbent is advantageously less than or equal to 600 m ² /g, in particular less than or equal to 400 m ² /g. The specific surface of the adsorbent is a surface measured by the BET method, i.e. the specific surface determined by nitrogen adsorption in accordance with the ASTM D 3663-78 standard established from the BRUNAUER-EMMETT method. -TELLER described in the periodical 'The Journal of the American Chemical Society', 6Q, 309 (1938). Advantageously, said adsorbent comprises less than 1% by weight of metallic elements, preferably is free of metallic elements. By metallic elements of the adsorbent, we mean the elements of groups 6 to 10 of the periodic table of elements (new IUPAC classification). The residence time of the charge in the adsorbent section is generally between 1 and 180 minutes.

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

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

According to another variant, said optional pretreatment step aO) is implemented in a washing section with an aqueous solution, for example water or an acid or basic solution. This washing section may include equipment making it possible to bring the load into contact with the aqueous solution and to separate the phases so as to obtain the pretreated load on the one hand and the aqueous solution comprising impurities on the other hand. Among this equipment, there may for example be a stirred reactor, a settler, a mixer-settler and/or a co- or counter-current washing column.

Said optional pretreatment step aO) can also optionally be fed with at least a fraction of a recycle stream, advantageously from step c) or step d) of the process, mixed or separately from the feed comprising a pyrolysis oil.

Said optional pretreatment step aO) thus makes it possible to obtain a pretreated feed which then feeds the selective hydrogenation step a) when it is present, or the hydroconversion step b).

Stage a) of selective hydrogenation (optional)

According to the invention, the method may comprise a stage a) of selective hydrogenation of the feedstock comprising a pyrolysis oil carried out in the presence of hydrogen, under conditions of hydrogen pressure and temperature making it possible to maintain said feedstock in the liquid phase and with a quantity of soluble hydrogen just necessary for selective hydrogenation of the diolefins present in the pyrolysis oil. The selective hydrogenation of diolefins in the liquid phase thus makes it possible to avoid or at least limit the formation of "gums", i.e. the polymerization of diolefins and therefore the formation of oligomers and polymers. Styrenic compounds, in particular styrene, optionally present in the filler can also behave like diolefins in terms of gum formation because the double bond of the vinyl group is conjugated with the aromatic nucleus. Said stage a) of selective hydrogenation makes it possible to obtain a selectively hydrogenated effluent, that is to say an effluent with a reduced content of olefins, in particular of diolefins and optionally of styrenic compounds.

According to the invention, said step a) of selective hydrogenation is implemented in a reaction section fed at least by said feed comprising a pyrolysis oil, or by the pretreated feed resulting from the optional step aO) of pretreatment, and a gas stream comprising hydrogen (H ₂ ).

Optionally, the reaction section of said step a) can also be additionally supplied with at least a fraction of a recycle stream, advantageously from step c) and/or from step d).

Said reaction section implements selective hydrogenation, preferably in a fixed bed, in the presence of at least one selective hydrogenation catalyst, advantageously at an average temperature (or WABT as defined below) between 100 and 280°C. , preferably between 120 and 260°C, preferably between 130 and 250°C, a pressure partial hydrogen between 1.0 and 20.0 MPa abs, preferably between 5.0 and 15.0 MPa abs and at an hourly volume rate (WH) between 0.3 and 10.0 h′ ¹ , of preferably between 0.5 and 5.0 h- ¹ .

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

WABT - (T "i, *, * T _S j: _K 1'2 with Titrée: the temperature of the effluent at the inlet of the reaction section and T _SO rtie: the temperature of the effluent at the outlet of the reaction section.

The hourly volume velocity (WH) is defined here as the ratio between the hourly volume flow of the feed comprising the pyrolysis oil, possibly pretreated, by the volume of catalyst(s).

The quantity of the gas stream comprising hydrogen (H ₂ ), supplying said reaction section of step a), is advantageously such that the hydrogen coverage is between 1 and 200 Nm ³ of hydrogen per m ³ of charge (Nm ³ /m ³ ), preferably between 1 and 50 Nm ³ of hydrogen per m ³ of charge (Nm ³ /m ³ ), preferably between 5 and 20 Nm ³ of hydrogen per m ³ of charge ( Nm ³ /m ³ ).

The hydrogen coverage is defined as the ratio of the volume flow rate of hydrogen taken under normal conditions of temperature and pressure compared to the volume flow rate of "fresh" load, that is to say the load to be treated, possibly pretreated , without taking into account any recycled fraction, at 15° C. (in normal m ³ , denoted Nm ³ , of H ₂ per m ³ of charge).

The gaseous stream comprising hydrogen, which supplies the reaction section of step a), can consist of a make-up of hydrogen and/or recycled hydrogen advantageously from step c) and/or step d).

Stage a) of selective hydrogenation is preferably carried out in a fixed bed. It can also be carried out in a bubbling bed or in a moving bed.

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

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

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

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

According to a variant, the hydro-dehydrogenating function comprises in particular at least one element from group VIII, preferably chosen from nickel and cobalt, and at least one element from group VI B, preferably chosen from molybdenum and tungsten. According to this variant, the total content expressed as oxides of the metal elements of groups VI B and VIII is preferably between 1% and 40% by weight, preferably from 5% to 30% by weight relative to the total weight of the catalyst. When the metal is cobalt or nickel, the metal content is expressed as CoO and NiO respectively. When the metal is molybdenum or tungsten, the metal content is expressed as MoChet WO3 respectively.

The weight ratio expressed as metal oxide between the metal (or metals) of group VI B relative to the metal (or metals) of group VIII is preferably between 1 and 20, and preferably between 2 and 10.

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

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

The support of said at least selective hydrogenation catalyst is preferably chosen from alumina, silica, silica-aluminas, magnesia, clays and mixtures thereof. Said support may contain doping compounds, in particular oxides chosen from boron oxide, in particular boron trioxide, zirconia, ceria, titanium oxide, phosphoric anhydride and a mixture of these oxides. Preferably, said at least selective hydrogenation catalyst comprises an alumina support, optionally doped with phosphorus and optionally boron. When phosphoric anhydride P2O5 is present, its concentration is less than 10% by weight relative to the weight of the alumina and advantageously at least 0.001% by weight relative to the total weight of the alumina. When boron trioxide B2O5 is present, its concentration is less than 10% by weight relative to the weight of the alumina and advantageously at least 0.001% relative to the total weight of the alumina. The alumina used may for example be a y (gamma) or q (eta) alumina.

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

Very preferably, in order to hydrogenate the diolefins as selectively as possible, step a) can implement, in addition to the selective hydrogenation catalysts described above, in addition at least one selective hydrogenation catalyst used in the process. step a) comprising less than 1% by weight of nickel and at least 0.1% by weight of nickel, preferably 0.5% by weight of nickel, expressed as nickel oxide NiO relative to the weight of said catalyst, and less than 5% by weight of molybdenum and at least 0.1% by weight of molybdenum, preferably 0.5% by weight of molybdenum, expressed as molybdenum oxide MoOs relative to the weight of said catalyst, on an alumina support. This catalyst with a low metal content is preferably placed upstream of the selective hydrogenation catalysts described above.

The content of impurities, in particular of diolefins, of the hydrogenated effluent obtained at the end of stage a) is reduced compared to that of the same impurities, in particular of diolefins, included in the charge of the process. Stage a) of selective hydrogenation generally makes it possible to convert at least 90% and preferably at least 99% of the diolefins contained in the initial charge. Step a) also allows the elimination, at least in part, of other contaminants, such as for example silicon. The hydrogenated effluent, obtained at the end of stage a) of selective hydrogenation, is sent, preferably directly, to stage b) of hydroconversion. Stage b) of hydroconversion

According to the invention, the treatment process comprises a step b) of hydroconversion implemented in a reaction section of hydroconversion, implementing at least one reactor with an ebullated bed, with a bed in an entrained bed and/or even with a mobile, comprising at least one hydroconversion catalyst, said hydroconversion reaction section being fed at least by said feed or by said hydrogenated effluent from step a), to obtain a hydroconverted effluent.

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

Advantageously, said hydroconversion reaction section is implemented at a pressure equivalent to that used in the reaction section of stage a) of selective hydrogenation when it is present, but at a higher temperature than that of the section reaction of stage a) of selective hydrogenation. Thus, said hydroconversion reaction section, regardless of whether a bubbling bed, entrained bed or/or moving bed reaction section is used, is advantageously implemented at a hydroconversion temperature between 300 and 450° C. , preferably between 350 and 420°C, at a partial pressure of hydrogen between 5.0 and 20.0 MPa abs., more preferably between 6.0 and 15.0 MPa abs, and at an hourly volumetric speed (WH ) between 0.03 and 2.0 h′ ¹ , preferably between 0.1 and 1.0 h′ ¹ .

According to the invention, the “hydroconversion temperature” corresponds to an average temperature in the hydroconversion reaction section of stage b). The hydroconversion temperature is advantageously determined according to the catalytic systems, the equipment, the configuration thereof, by a person skilled in the art. For example, the bubbling bed hydroconversion temperature is determined by taking the arithmetic mean of the temperature measurements in the catalytic bed. The hourly volumetric speed (WH) is defined here as the ratio between the hourly volumetric flow rate of the hydrogenated effluent from stage a) per volume of catalyst(s). The hydrogen coverage in step b) is advantageously between 50 and 1000 Nm ³ of hydrogen per m ³ of fresh charge, and preferably between 60 and 500 Nm ³ of hydrogen per m ³ of fresh charge, preferably between 100 and 300 Nm ³ of hydrogen per m ³ of fresh charge. The hydrogen coverage is defined as the ratio of the volume flow rate of hydrogen taken under normal conditions of temperature and pressure compared to the volume flow rate of "fresh" load, that is to say the load to be treated, possibly pretreated , without taking into account any recycled fraction, at 15° C. (in normal m ³ , denoted Nm ³ , of H ₂ per m ³ of charge). The gaseous stream comprising hydrogen, which supplies the reaction section of step b), can consist of a make-up of hydrogen and/or recycled hydrogen advantageously from step c) and/or step d).

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

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

Advantageously, the hydroconversion step allows the hydrogenation of at least 80%, and preferably of all of the remaining olefins, but also the conversion at least in part of other impurities present in the feed, such as aromatic compounds , metallic compounds, sulfur compounds, nitrogen compounds, halogenated compounds (in particular chlorinated compounds), oxygenated compounds. Preferably, the nitrogen content at the outlet of step b) is less than 10 ppm by weight. Step b) can also make it possible to further reduce the content of contaminants, such as that of metals, in particular the silicon content. Preferably, the metal content at the outlet of step b) is less than 10 ppm by weight, and preferably less than 2 ppm by weight, and the silicon content is less than 5 ppm by weight.

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

Stage b) hydroconversion in an ebullated bed

Thus, according to a first variant, step b) of hydroconversion is implemented in a reaction section of hydroconversion implementing at least one boiling bed reactor.

The operation of the ebullated bed reactor, including the recycling of reactor liquids upwards through the stirred bed of catalyst is generally well known. A mixture of feedstock and hydrogen is passed from bottom to top over a bed of catalytic particles at a rate such that the particles are subjected to forced random motion as the liquid and gas pass through the bed from bottom to top. The movement of the catalyst bed is controlled by a flow of recycle liquid so that, at steady state, the mass of the catalyst does not rise above a definable level in the reactor. The vapors and liquid being hydrogenated pass through the upper level of the bed of catalytic particles to reach a zone substantially free of catalyst, and then they are discharged from the upper part of the reactor. A fraction of the reactor liquids is continuously recycled to the reactor. The bubbling bed technologies use supported catalysts, generally in the form of extrudates or beads whose diameter is generally of the order of 1 mm or less than 1 mm. The catalysts remain inside the reactors and are not evacuated with the products. Catalyst activity can be kept constant by in-line catalyst replacement. It is therefore not necessary to stop the unit to change the used catalyst, nor to increase the reaction temperatures along the cycle to compensate for the deactivation. In addition, the fact of working under constant operating conditions makes it possible to obtain constant yields and product qualities throughout the cycle. Also, because the catalyst is kept in agitation by a significant recycling of liquid, the pressure drop on the reactor remains low and constant, and the reaction exotherms are rapidly averaged over the catalytic bed.

The used catalyst is partly replaced by fresh catalyst by drawing off at the bottom of the reactor and introducing, either at the top of the reactor or at the bottom of the reactor, fresh or new catalyst at regular time intervals, that is to say by example by puff or almost continuously. One can for example introduce fresh catalyst every day. The rate of replacement of spent catalyst with fresh catalyst can be, for example, from about 0.01 kilogram to about 10 kilograms per cubic meter of charge. This withdrawal and this replacement are carried out using devices allowing the continuous operation of this hydroconversion step. The unit usually comprises an internal recirculation pump enabling the catalyst to be maintained in an ebullated bed by continuous recycling of at least part of the liquid drawn off at the top of the reactor and reinjected at the bottom of the reactor. It is also possible to send the spent catalyst withdrawn from the reactor to a regeneration zone in which the carbon and the sulfur which it contains are eliminated, then to return this regenerated catalyst to the hydroconversion stage. It is also possible to send the regenerated catalyst to a rejuvenation zone in which a treatment aimed at improving the activity of the catalyst is carried out (presulphurization, additivation, etc.), then to return this rejuvenated catalyst to the step of hydro conversion.

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

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

The support for said hydroconversion catalyst is advantageously chosen from alumina, silica, silica-aluminas, magnesia, clays and mixtures thereof. Said support may also contain doping compounds, in particular oxides chosen from boron, in particular boron trioxide, zirconia, ceria, titanium oxide, phosphoric anhydride and a mixture of these oxides. Preferably, said hydroconversion catalyst comprises an alumina support, preferably an alumina support doped with phosphorus and optionally boron. When phosphoric anhydride P2O5 is present, its concentration is less than 10% by weight relative to the weight of the alumina and advantageously at least 0.001% by weight relative to the total weight of the alumina. When boron trioxide B ₂ O ₅ is present, its concentration is less than 10% by weight relative to the weight of the alumina and advantageously at least 0.001% relative to the total weight of the alumina. The alumina used may for example be a y (gamma) or q (eta) alumina.

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

Advantageously, said hydroconversion catalyst used in step b) 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 of said hydroconversion 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 of the hydroconversion catalyst is measured by the BET method, that is to say the specific surface determined by nitrogen adsorption in accordance with the ASTM D 3663 standard established from the BRUNAUER-EMMETT-TELLER method described in the periodical 'The Journal of the American Chemical Society', 6Q, 309 (1938). Such a specific surface makes it possible to further improve the removal of contaminants, in particular of metals such as silicon.

Hydroconversion catalysts are distinguished from hydrotreatment catalysts in particular by a porosity adapted to the treatment of impurities, in particular metal, and in particular by the presence of macroporosity.

According to another aspect of the invention, the hydroconversion catalyst as described above further comprises one or more organic compounds containing oxygen and/or nitrogen and/or sulfur. Such a catalyst is often designated by the term "additive catalyst". Generally, the organic compound is chosen from a compound comprising one or more chemical functions chosen from a carboxylic function, alcohol, thiol, thioether, sulphone, sulphoxide, ether, aldehyde, ketone, ester, carbonate, amine, nitrile, imide, oxime, urea and amide or even compounds including a furan ring or even sugars. Stage b) of hydroconversion into an entrained bed

According to a second variant, step b) of hydroconversion is implemented in a reaction section of hydroconversion implementing at least one reactor with an entrained bed, also called a slurry reactor according to Anglo-Saxon technology. Feedstock, hydrogen and catalyst are injected from below and flow in an updraft. The hydroconverted effluent and the unconsumed hydrogen as well as the catalyst are withdrawn from the top. Slurry hydroconversion technologies use catalyst dispersed in the form of very small particles, the size of which is a few tens of microns or less (usually 0.001 to 100 µm). The catalysts, or their precursors, are injected with the feed to be converted at the inlet of the reactors. The catalysts pass through the reactors with the charges and the products being converted, then they are driven with the reaction products out of the reactors. They are found after separation in the heaviest fraction.

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

The catalysts used can be powders of heterogeneous solids (such as natural ores, iron sulphate, etc.), dispersed catalysts resulting from water-soluble precursors ("water soluble dispersed catalyst" according to the English terminology -Saxon) such as phosphomolybdic acid, ammonium molybdate, or a mixture of Mo or Ni oxide with aqueous ammonia.

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

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

The concentration of the catalyst, expressed as a metallic element, is generally between 1 and 10,000 ppm relative to the charge. In general, the catalysts are prepared before being injected into the charge. The preparation process is adapted according to the state in which the precursor is and its nature. In all cases, the precursor is sulfurized (ex-situ or in-situ) to form the catalyst dispersed in the charge.

For the preferred case of so-called oil-soluble catalysts, in a typical process, the precursor is mixed with a carbonaceous charge (which may be part of the charge to be treated, an external charge, a recycled fraction, etc.), the mixture is optionally dried at least in part, then or simultaneously sulfurized by adding a sulfur compound (H ₂ S preferred) and heated. Preparations of these catalysts are described in the prior art.

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

The preferred solid additives are mineral oxides such as alumina, silica, mixed Al/Si oxides, spent catalysts supported (for example, on alumina and/or silica) containing at least one group VIII element (such as Ni, Co) and/or at least one element from group VI B (such as Mo, W). Mention will be made, for example, of the catalysts described in application US2008/177124. Carbonaceous solids with a low hydrogen content (for example 4% hydrogen) such as coke, optionally pretreated, can also be used. It is also possible to use mixtures of such additives. Their particle sizes are preferably less than 1 mm. The content of any solid additive present at the inlet of the entrained bed hydroconversion reaction zone is between 0 and 10% by weight, preferably between 1 and 3% by weight, and the content of the catalytic solutions is between 0 and 10% wt, preferably between 0 and 1 wt% relative to the weight of the injected filler.

When hydroconversion stage b) is carried out in an entrained bed reactor, a filtration stage in order to recover the catalyst is necessary before sending the hydroconverted effluent to stage c).

Moving bed hydroconversion step b)

According to a third variant, step b) of hydroconversion is implemented in a hydroconversion reaction section implementing at least one moving bed reactor.

The feedstock and hydrogen can flow upwards in moving bed reactors (countercurrent processes) or downward flow (cocurrent processes). The catalyst flows progressively by gravity from top to bottom and in plug flow inside the catalytic zone. It is withdrawn from below by any appropriate means, for example an elevator (called a "lift" according to Anglo-Saxon terminology). An in-line device ensures the semi-continuous renewal of the catalyst of the moving bed reactors: part of the spent catalyst is drawn off at the bottom of the reactor while fresh catalyst is introduced at the top of the reactor. The temperature there is controlled by inter- or intra-reactor quenching.

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

The hydroconversion catalyst used in the moving bed of step b) of the process according to the invention is advantageously a catalyst comprising a support, preferably amorphous and very preferably alumina and at least one group VIII metal. chosen from nickel and cobalt and preferably nickel, said element from group VIII preferably being used in combination with at least one metal from group VIB chosen from molybdenum and tungsten and preferably, the metal from group VIB is molybdenum. Preferably, the hydroconversion catalyst comprises nickel as a group VIII element and molybdenum as a group VIB element. The nickel content is advantageously between 0.5 and 10% expressed by weight of nickel oxide (NiO) and preferably between 0.7 and 6% by weight, and the molybdenum content is advantageously between 1 and 30% expressed by weight of molybdenum trioxide (MoOs), and preferably between 4 and 20% by weight, the percentages being expressed as percentage by weight relative to the total weight of the catalyst. This catalyst is advantageously in the form of extrudates or beads. This catalyst may also advantageously contain phosphorus and preferably a content of phosphoric anhydride P ₂ 0 ₅ of less than 20% and preferably less than 10% by weight, the percentages being expressed as weight percentage relative to the total weight of the catalyst. The catalyst can also be a catalyst containing an organic compound as described above.

According to yet another variant, step b) of hydroconversion can be implemented in a reaction section of hydroconversion implementing a combination of at least one bubbling bed reactor, at least one bed reactor in entrained bed and/or at least one moving bed reactor, in any order.

Preferably, step b) is implemented in a hydroconversion reaction section implementing at least one boiling bed reactor.

Separation step c)

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

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

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

This separation step c) makes it possible in particular to eliminate the ammonium chloride salts, which are formed by reaction between the chloride ions, released by the hydrogenation of the chlorinated compounds in the HCl form, in particular during steps a) and b). then dissolution in water, and the ammonium ions, generated by the hydrogenation of the nitrogenous compounds in the form of NH ₃ in particular during step b) and/or provided by injection of an amine then dissolution in water, and thus to limit the risks of clogging, in particular in the transfer lines and/or in the sections of the process of the invention and/or the transfer lines to the steam cracker, due to the precipitation of ammonium chloride salts . It also eliminates the hydrochloric acid formed by the reaction of hydrogen ions and chloride ions as well as part of the CO and CO2 if there is oxygen in the plastic pyrolysis oil and/ or CSR. Depending on the content of chlorinated compounds in the initial charge to be treated, a stream containing an amine such as, for example, monoethanolamine, diethanolamine and/or monodiethanolamine can be injected upstream of stage a) of selective hydrogenation and /or stage b) of hydroconversion and/or stage c) of separation, preferably upstream of stage a) of selective hydrogenation when it is present in order to ensure a sufficient quantity of ammonium ions to combine the chloride ions formed during the hydroconversion step, thus making it possible to limit the formation of hydrochloric acid and thus to limit the corrosion downstream of the separation section.

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

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

The washing/separation section of step c) can at least partly be carried out in common or separate washing and separation equipment, this equipment being well known (separator drums which can operate at different pressures and temperatures, pumps, heat exchangers heat pumps, washing columns, etc.).

In a possible embodiment of the invention, step c) of separation comprises the injection of an aqueous solution into the hydroconverted effluent from step b), followed by the washing/separation section advantageously comprising a separation phase making it possible to obtain at least one aqueous effluent charged with ammonium salts, a washed liquid hydrocarbon effluent and a partially washed gaseous effluent. The aqueous effluent charged with ammonium salts and the washed liquid hydrocarbon effluent can then be separated in a settling flask in order to obtain said hydrocarbon effluent and said aqueous effluent. Said partially washed gaseous effluent can be introduced in parallel into a washing column where it circulates countercurrent to an aqueous flow, preferably of the same nature as the aqueous solution injected into the hydrocarbon effluent, which makes it possible to eliminate at least partly, preferably totally, the hydrochloric acid contained in the partially washed gaseous effluent and thus to obtain said gaseous effluent, preferably comprising mostly hydrogen, and an acidic aqueous stream. Said aqueous effluent from the settling flask can optionally be mixed with said acid aqueous stream, and be used, optionally mixed with said acid aqueous stream in a water recycling circuit to supply stage c) of separation with said aqueous solution upstream of the washing/separation section and/or in said aqueous stream in the washing column. Said water recycling circuit may comprise a make-up of water and/or of a basic solution and/or a purge making it possible to evacuate the dissolved salts.

The gas fraction(s) resulting from step c) of separation may (may) be subject to purification(s) and additional separation(s) with a view to recovering at least one gas rich in hydrogen which can be recycled upstream of steps a) and/or b) and/or light hydrocarbons, in particular ethane, propane and butane, which can advantageously be sent separately or as a mixture to one or more furnaces of the step e) of steam cracking so as to increase the overall yield of olefins.

The hydrocarbon effluent from step c) separation is sent, in part or in whole, to step d) fractionation. Part of the hydrocarbon effluent from stage c) can also be sent directly to the inlet of a steam cracking unit or even be recycled in stages a) and/or b).

Step d) splitting (optional)

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

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

Fractionation step d) is advantageously carried out at a pressure of less than or equal to 1.0 MPa abs., preferably between 0.1 and 1.0 MPa abs. According to one embodiment, step d) can be carried out in a section advantageously comprising at least one stripping column equipped with a reflux circuit comprising a reflux drum. Said stripping column is fed by the liquid hydrocarbon effluent from step c) and by a stream of steam. The liquid hydrocarbon effluent from step c) can optionally be reheated before entering the stripping column. Thus, the lightest compounds are entrained at the top of the column and in the reflux circuit comprising a reflux drum in which a gas/liquid separation takes place. The gaseous phase, which includes the light hydrocarbons, is withdrawn from the reflux drum, in a gas stream. The cut comprising compounds having a boiling point of less than or equal to 150° C. is advantageously withdrawn from the reflux drum. The hydrocarbon cut comprising compounds having a boiling point above 150° C. is advantageously drawn off at the bottom of the stripping column.

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

The cut comprising compounds having a boiling point lower than or equal to 150°C and the cut comprising compounds having a boiling point higher than 150°C, optionally mixed, can be sent, in whole or part, to a steam cracking unit, at the end of which olefins can be (re)formed to participate in the formation of polymers. Preferably, only part of said cuts is sent to a steam cracking unit; at least a fraction of the remaining part is optionally recycled in at least one of the process steps and/or sent to a fuel storage unit, for example a naphtha storage unit, a diesel storage unit or a kerosene storage unit, from conventional petroleum feedstocks.

According to a preferred mode, the hydrocarbon cut comprising compounds having a boiling point of less than or equal to 150° C., all or part, is sent to a steam cracking unit, while the hydrocarbon cut comprising compounds having a boiling point of boiling above 150° C. is recycled in stage a) and/or b), and/or sent to a fuel storage unit.

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

In another particular embodiment, fractionation step d) can make it possible to obtain, in addition to a gas stream, a naphtha cut comprising compounds having a boiling point less than or equal to 150° C., preferably between 80 and 150°C, and a kerosene cut comprising compounds having a boiling point above 150°C and less than or equal to 280°C, a diesel cut comprising compounds having a boiling point above 280°C and lower than 360° C. and a hydrocarbon cut comprising compounds having a boiling point greater than or equal to 360° C., referred to as a heavy hydrocarbon cut. The naphtha cut, the kerosene cut and/or the diesel cut can be, in whole or in part, either sent to a steam cracking unit, or respectively to a naphtha, kerosene or diesel pool from conventional petroleum feedstocks, or be recycled; the heavy cut can for its part be sent, at least in part, to a steam cracking unit, or be recycled, in particular in stage b) of hydroconversion.

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

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

The hydrocarbon effluent from step c) of separation, or at least one of the two liquid hydrocarbon stream(s) from step d), can be wholly or partly sent to a step e ) of steam cracking.

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

Said step e) of steam cracking is advantageously carried out in at least one pyrolysis furnace at a temperature of between 700 and 900° C., preferably between 750 and 850° C., and at a pressure of between 0.05 and 0.3 MPa relative. The residence time of the hydrocarbon compounds is generally less than or equal to 1.0 second (denoted s), preferably between 0.1 and 0.5 s. Advantageously, steam is introduced upstream of step e) of optional steam cracking and after the separation (or fractionation). The quantity of water introduced, advantageously in the form of steam, is advantageously between 0.3 and 3.0 kg of water per kg of hydrocarbon compounds at the inlet of stage e). Preferably, optional step e) is carried out in several pyrolysis furnaces in parallel so as to adapt the operating conditions to the different flows supplying step e) in particular from step d), and also to manage the decoking of the tubes. A furnace comprises one or more tubes arranged in parallel. An oven can also refer to a group of ovens operating in parallel. For example, a furnace can be dedicated to cracking the cut comprising compounds with a boiling point less than or equal to 150°C.

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

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

Variants of the process

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

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

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

All embodiments can comprise and preferably consist of more than one pretreatment step aO).

All embodiments can comprise and preferably consist of more than one steam cracking step f).

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

• Stage c) of hydrotreatment (optional)

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

Advantageously, the hydrotreatment step implements the hydrotreatment reactions well known to those skilled in the art, and more particularly hydrotreatment reactions such as the hydrogenation of aromatics, hydrodesulphurization and hydrodenitrogenation. In addition, the hydrogenation of the remaining olefins and halogenated compounds as well as the hydrodemetallization are continued.

The hydrotreating step is implemented in a hydrotreating reaction section, implementing at least one fixed bed reactor having n catalytic beds, n being an integer greater than or equal to 1, each comprising at least one catalyst of hydrotreating.

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

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

When the hydrotreating step is carried out after step d) of fractionation, said hydrotreating reaction section is supplied with at least a part of said hydrocarbon cut comprising compounds having a boiling point above 150° C. of step d) and a gas stream comprising hydrogen, to obtain a hydrotreated effluent.

Said hydrotreating reaction section is advantageously carried out at an average hydrotreating temperature between 250 and 430° C., preferably between 300 and 400° C., at a partial pressure of hydrogen between 1.0 and 20.0 MPa abs., preferably between 3.0 and 15.0 MPa abs, and at a volumetric hourly rate (VVH) between 0.1 and 10.0 h' ¹ , preferably between 0.1 and 5.0 h' ¹ , preferably between 0.2 and 2.0 h′ ¹ , preferably between 0.2 and 1.0 h' ¹ . The hydrogen coverage in the hydrotreatment stage is advantageously between 50 and 2000 Nm ³ of hydrogen per m ³ of feed which feeds the hydrotreatment stage, and preferably between 100 and 1000 Nm ³ of hydrogen per m ³ of charge, preferably between 120 and 800 Nm ³ of hydrogen per m ³ of charge.

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

The gaseous stream comprising hydrogen, which supplies the reaction section of the hydrotreatment stage, may consist of a make-up of hydrogen and/or recycled hydrogen advantageously from stage c) and/or step d).

Advantageously, said hydrotreating step is implemented in a hydrotreating reaction section comprising at least one, preferably between one and five, fixed-bed reactor(s) having n catalytic beds, n being an integer greater than or equal to to one, preferably between one and ten, preferably between two and five, said bed(s) each comprising at least one, and preferably not more than ten, catalyst(s) of hydrotreating. When a reactor comprises several catalytic beds, that is to say at least two, preferably between two and ten, preferably between two and five catalytic beds, said catalytic beds are preferably arranged in series in said reactor.

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

In another embodiment of the invention, said hydrotreating reaction section comprises a single fixed-bed reactor containing n catalytic beds, n being an integer greater than or equal to one, preferably between one and ten, so favorite between two and five.

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

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

The support for said hydrotreating catalyst is advantageously chosen from alumina, silica, silica-aluminas, magnesia, clays and mixtures thereof. Said support may also advantageously contain doping compounds, in particular oxides chosen from boron oxide, in particular boron trioxide, zirconia, ceria, titanium oxide, phosphoric anhydride and a mixture of these oxides. Preferably, said hydrotreating catalyst comprises an alumina support, more preferably an alumina support doped with phosphorus and optionally boron. When phosphoric anhydride P2O5 is present, its concentration is less than 10% by weight relative to the weight of the alumina and advantageously at least 0.001% by weight relative to the total weight of the alumina. When boron trioxide B2O5 is present, its concentration is less than 10% by weight relative to the weight of the alumina and advantageously at least 0.001% relative to the total weight of the alumina. The alumina used may for example be a y (gamma) or q (eta) alumina. Said hydrotreating catalyst is for example in the form of extrudates.

Advantageously, said hydrotreatment catalyst used in the hydrotreatment step 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 of said 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 of the hydrotreating catalyst is measured by the BET method, that is to say the specific surface determined by nitrogen adsorption in accordance with the ASTM D 3663 standard established from the BRUNAUER-EMMETT-TELLER method described in the periodical 'The Journal of the American Chemical Society', 6Q, 309 (1938). Such a specific surface makes it possible to further improve the removal of contaminants, in particular of metals such as silicon.

According to another aspect of the invention, the hydrotreating catalyst as described above further comprises one or more organic compounds containing oxygen and/or nitrogen and/or sulfur. Such a catalyst is often designated by the term "additive catalyst". Generally, the organic compound is chosen from a compound comprising one or more chemical functions chosen from a carboxylic function, alcohol, thiol, thioether, sulphone, sulphoxide, ether, aldehyde, ketone, ester, carbonate, amine, nitrile, imide, oxime, urea and amide or even compounds including a furan ring or even sugars.

When the hydrotreatment step is carried out before step c) of separation and after step b) of hydroconversion, and according to a first variant, said hydrotreatment step is carried out without an intermediate separation step between step hydroconversion b) and the hydrotreating step. The effluent from the hydroconversion stage b) does not undergo any stage of intermediate separation of a gas stream between the hydroconversion stage b) and the hydrotreatment stage. This configuration can be qualified as an integrated diagram. By "without intermediate separation step", is meant in the present invention the fact that at least part of the effluent from the hydroconversion step b) is introduced into the section allowing the implementation of the hydrotreating step without changing chemical composition and without significant pressure loss. The term “separation” is understood to mean one or more separating drums and/or one or more stripping or distillation columns, these equipment being able to operate at different temperatures or pressures. “Significant pressure loss” means a pressure loss caused by a valve or an expansion turbine, which could be estimated at a pressure loss of more than 10% of the total pressure. A person skilled in the art generally uses these pressure losses or expansions during the separation stages. In one embodiment, all of the effluent from the hydroconversion stage b) is introduced into the section allowing the implementation of the hydrotreatment stage.

In another embodiment, only part of the effluent from the hydroconversion step b) is introduced into the section allowing the implementation of the hydrotreatment step. This embodiment is however not contradictory with the fact that the process is without intermediate separation step. This embodiment may consist in dividing the effluent from the hydroconversion step b) into two streams having the same composition, one going to the hydrotreatment step located downstream of it. This embodiment can therefore be similar to a partial short-circuit of the hydrotreatment section but, for the part of the effluent from the hydroconversion section b) going to the hydrotreatment section, there is no has no separation, change in chemical composition, or significant pressure loss. Another variant of this short-circuit embodiment may consist in dividing the effluent from the hydroconversion stage b) into several streams having the same composition, and in sending one or more of these streams to the inlet of a first hydrotreating reactor and one or more other such streams to one or more downstream hydrotreating reactors.

When the hydrotreatment step is carried out before step c) of separation and after step b) of hydroconversion, and according to a second variant, said hydrotreatment step is carried out with an intermediate separation step between the hydroconversion step b) and the hydrotreating step. Advantageously, said intermediate separation step comprises a step of fractionating all or part of the hydrocarbon effluent from step c), to obtain at least one gas stream, a hydrocarbon cut comprising compounds having a lower boiling point or equal to 360°C and a hydrocarbon cut comprising compounds having a boiling point above 360°C. Said hydrocarbon cut comprising compounds having a boiling point less than or equal to 360° C. is then introduced into the hydrotreatment stage, while the cut comprising compounds having a boiling point higher than 360° C. is preferably recycled in stage b) of hydroconversion.

When the hydrotreatment stage is carried out before stage c) of separation and after stage b) of hydroconversion and in order to avoid entraining fine catalysts and/or catalysts resulting from stage b ) hydroconversion in said hydrotreatment reaction section, recovery means can be placed upstream or at the inlet of said hydrotreatment reaction section, for example one or more filter(s) or even reactor internals, for example of the filter plate type, can be used. An example of a filter plate is described in patent FR3051375. • Hydrocracking stage (optional)

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

Advantageously, the hydrocracking step implements hydrocracking reactions well known to those skilled in the art, and more particularly makes it possible to convert heavy compounds, for example compounds having a boiling point above 150° C. into compounds having a boiling point less than or equal to 150° C. contained in the hydrotreated effluent or separated during fractionation step d). Other reactions, such as hydrogenation of olefins, aromatics, hydrodemetallization, hydrodesulfurization, hydrodenitrogenation, etc. can continue.

Compounds with a boiling point above 150°C have a high BMCI and contain, compared to lighter compounds, more naphthenic, naphtheno-aromatic and aromatic compounds leading to a higher C/H ratio. This high ratio is a cause of coking in the steam cracker, thus requiring steam cracking furnaces dedicated to this cut. When it is desired to minimize the yield of these heavy compounds (diesel cut) and maximize the yield of light compounds (naphtha cut), these compounds can be transformed at least in part into light compounds by hydrocracking, a cut generally favored for a steam cracking unit .

The hydrocracking step is implemented in a hydrocracking reaction section, implementing at least one fixed-bed reactor having n catalytic beds, n being an integer greater than or equal to 1, each comprising at least one catalyst of hydrocracking.

When the hydrocracking step is carried out after a hydrotreating step, said hydrocracking reaction section is supplied with at least a portion of said hydrotreated effluent and a gas stream comprising hydrogen, to obtain a hydrocracked effluent, said step hydrotreatment which can be carried out before or after step c) of separation, or even after step d) of fractionation as described above.

When the hydrocracking step is carried out after step d) of fractionation, said hydrocracking reaction section is supplied with at least part of said hydrocarbon cut comprising compounds having a boiling point above 150° C. of step d) and a gas stream comprising hydrogen, to obtain a hydrocracked effluent. Said hydrocracking reaction section is advantageously carried out at an average temperature between 250 and 450° C., preferably between 320 and 440° C., at a partial pressure of hydrogen between 1.5 and 20.0 MPa abs., preferably between 2 and 18.0 MPa abs, and at an hourly volume velocity (WH) between 0.1 and 10.0 h' ¹ , preferably between 0.1 and 5.0 h' ¹ , preferably between 0, 2 and 4 ^o'clock . The hydrogen coverage in the hydrocracking stage is advantageously between 80 and 2000 Nm ³ of hydrogen per m ³ of fresh feed which feeds stage a) or b), and preferably between 200 and 1800 Nm ³ d hydrogen per m ³ of fresh charge which feeds stage a) or b). The definitions of the mean temperature (WABT), of the WH and of the hydrogen coverage correspond to those described above in the selective hydrogenation step a).

Advantageously, said hydrocracking reaction section is implemented at a pressure equivalent to that used in the reaction section of the hydrotreating stage.

Advantageously, said hydrocracking step is implemented in a hydrocracking reaction section comprising at least one, preferably between one and five, fixed-bed reactor(s) having n catalytic beds, n being an integer greater than or equal to to one, preferably between one and ten, preferably between two and five, said bed(s) each comprising at least one, and preferably not more than ten, catalyst(s) of hydrocracking. When a reactor comprises several catalytic beds, that is to say at least two, preferably between two and ten, preferably between two and five catalytic beds, said catalytic beds are preferably arranged in series in said reactor.

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

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

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

The second hydrocracking step is implemented in a hydrocracking reaction section, implementing at least one fixed bed having n catalytic beds, n being an integer greater than or equal to 1, each comprising at least one catalyst of hydrocracking, said hydrocracking reaction section is fed with the hydrocarbon cut comprising compounds having a boiling point above 150° C. resulting from the first hydrocracking stage and a gas stream comprising hydrogen, said reaction section the hydrocracking being carried out at an average temperature between 250 and 450° C., a partial pressure of hydrogen between 1.5 and 20.0 MPa abs. and an hourly volume rate between 0.1 and 10.0 h ^-1 , to obtain a hydrocracked effluent which can be sent to stage c) of separation. The preferred operating conditions and catalysts used in the second hydrocracking stage are those described for the first hydrocracking stage. The operating conditions and catalysts used in the two hydrocracking stages can be identical or different.

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

These operating conditions used in the hydrocracking step(s) generally make it possible to achieve a conversion per pass greater than 15% by weight, and even more preferably between 20 and 95% by weight, into products having at least 80 % by weight of compounds having boiling points less than or equal to 150°C. When the process is carried out in two hydrocracking stages, the conversion per pass in the second stage is kept moderate in order to maximize the selectivity for compounds of the naphtha cut (having a boiling point less than or equal to 150°C, in particular between 80 and less than or equal to 150°C). Conversion per pass is limited by the use of a high recycle rate on the second stage hydrocracking loop. This rate is defined as the ratio between the feed rate of the second hydrocracking step and the feed rate of step a), preferably this ratio is between 0.2 and 4, preferably between 0 .5 and 2.5.

The hydrocracking step(s) thus does not necessarily make it possible to transform all the compounds having a boiling point above 150° C. into compounds having a boiling point boiling point less than or equal to 150°C. After fractionation step d), there may therefore remain a greater or lesser proportion of compounds having a boiling point above 150°C. To increase the conversion, at least a part of this unconverted cut can be recycled as described below to the first hydrocracking stage or else be sent to a second hydrocracking stage. Another part can be purged.

Depending on the operating conditions of the process, said purge may be between 0 and 10% by weight of the cut comprising compounds having a boiling point above 150° C. relative to the incoming feed, and preferably between 0.5 % and 5% weight.

In accordance with the invention, the hydrocracking step(s) operate(s) in the presence of at least one hydrocracking catalyst.

The hydrocracking catalyst(s) used in the hydrocracking step(s) are conventional hydrocracking catalysts known to those skilled in the art, of the bifunctional type combining an acid function with a hydro-dehydrogenating agent and optionally at least one binding matrix. The acid function is provided by supports with a large surface area (generally 150 to 800 m ² /g) exhibiting surface acidity, such as halogenated aluminas (chlorinated or fluorinated in particular), combinations of boron and aluminum oxides, amorphous silica-aluminas and zeolites. The hydrodehydrogenating function is provided by at least one metal from group VI B of the periodic table and/or at least one metal from group VIII.

Preferably, the hydrocracking catalyst(s) comprise a hydro-dehydrogenating function comprising at least one group VIII metal chosen from iron, cobalt, nickel, ruthenium, rhodium, palladium and platinum, and preferably among cobalt and nickel. Preferably, said catalyst(s) also comprise at least one metal from group VIB chosen from chromium, molybdenum and tungsten, alone or as a mixture, and preferably from molybdenum and tungsten. Hydro-dehydrogenating functions of the NiMo, NiMoW, NiW type are preferred.

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

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

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

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

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

Preferably, the hydrocracking catalyst(s) also optionally comprise a zeolite chosen from Y zeolites, preferably from USY zeolites, alone or in combination, with other zeolites from beta zeolites, ZSM-12, IZM-2, ZSM-22, ZSM-23, SAPO-11, ZSM-48, ZBM-30, alone or as a mixture. Preferably, the zeolite is USY zeolite alone.

In the case where said catalyst comprises a zeolite, the zeolite content in the hydrocracking catalyst(s) is advantageously between 0.1 and 80% by weight, preferably between 3 and 70% by weight, the percentages being expressed as a percentage of zeolite relative to the total weight of the catalyst.

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

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

Another preferred catalyst includes, and preferably consists of, nickel, tungsten, alumina and silica-alumina. Another preferred catalyst includes, and preferably consists of, nickel, tungsten, USY zeolite, alumina and silica-alumina.

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

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

According to another aspect of the invention, the hydrocracking catalyst as described above further comprises one or more organic compounds containing oxygen and/or nitrogen and/or sulfur. Such a catalyst is often designated by the term "additive catalyst". Generally, the organic compound is chosen from a compound comprising one or more chemical functions chosen from a carboxylic function, alcohol, thiol, thioether, sulphone, sulphoxide, ether, aldehyde, ketone, ester, carbonate, amine, nitrile, imide, oxime, urea and amide or even compounds including a furan ring or even sugars.

The preparation of selective hydrogenation (stage a), hydroconversion (stage b), hydrotreating and hydrocracking catalysts is known and generally includes a stage of impregnation of group VIII and group VIB metals when is present, and optionally phosphorus and/or boron on the support, followed by drying, then optionally by calcination. In the case of an additive catalyst, the preparation is generally carried out by simple drying without calcination after introduction of the organic compound. Here, calcination means a heat treatment under a gas containing air or oxygen at a temperature greater than or equal to 200°C. Before their use in a step of the process, the catalysts are generally subjected to sulfurization in order to form the active species. The catalyst of step a) can also be a catalyst used in its reduced form, thus involving a reduction step in its preparation.

Depending on the content of sulfur compounds in the initial charge to be treated, a stream containing a sulfurizing agent can be injected upstream of stage a) of selective hydrogenation and/or stage b) of hydroconversion and/or the hydrotreating step and/or the hydrocracking step when they are present, preferably upstream of step a) of selective hydrogenation when it is present and/or step b) of hydroconversion in order to ensure a sufficient quantity of sulfur to form or maintain the active species of the catalyst (in sulfur form). This activation or sulfurization step is carried out by methods well known to those skilled in the art, and advantageously under a sulphur-reducing atmosphere in the presence of hydrogen and hydrogen sulphide. Sulfurizing agents are H2S gas, elemental sulphur, CS2, mercaptans, sulphides and/or polysulphides, hydrocarbon cuts with a boiling point below 400°C containing sulfur compounds or any other compound containing sulfur used for the activation of the hydrocarbon charges in order to sulfurize the catalyst. Said sulfur-containing compounds are advantageously chosen from alkyl disulphides such as, for example, dimethyl disulphide (DM DS), alkyl sulphides, such as, for example, dimethyl sulphide, thiols such as, for example, n -butylmercaptan (or 1-butanethiol) and polysulphide compounds of the tertiononylpolysulphide type. The catalyst can also be sulfurized by the sulfur contained in the charge to be desulfurized. Preferably, the catalyst is sulfurized in situ in the presence of a sulfurizing agent and a hydrocarbon charge. Very preferably, the catalyst is sulfurized in situ in the presence of the charge containing dimethyl disulfide.

The gas stream comprising hydrogen, which feeds the reaction section of the selective hydrogenation stage (stage a), hydroconversion stage (stage b), and the hydrotreating and/or hydrocracking stages when they are present may consist of a make-up of hydrogen and/or of hydrogen which is advantageously recycled from stage c) and/or from stage d). Preferably, an additional gas stream comprising hydrogen is advantageously introduced at the inlet of each reactor, in particular operating in series, and/or at the inlet of each catalytic bed from the second catalytic bed of the reaction section. These additional gas streams are also called cooling streams. They make it possible to control the temperature in the reactor in which the reactions implemented are generally very exothermic.

Figure 1 represents this diagram of a particular embodiment of the method of the present invention, comprising:

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

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

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

- a stage d) of fractionation of the liquid hydrocarbon fraction 11 making it possible to obtain at least one gaseous fraction 12, a hydrocarbon fraction 13 comprising compounds having a boiling point less than or equal to 150° C. and a hydrocarbon fraction 14 comprising compounds having a boiling point above 150°C.

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

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

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

Instead of injecting the amine stream 3 and/or the sulphurizing agent 4 at the inlet of stage a) of selective hydrogenation, it is possible to inject it at the inlet of each of the reaction stages, in particular at the inlet of the hydroconversion step b) and optionally as an input to the hydrotreating and/or hydrocracking steps when they are present. It is also possible not to inject the amine stream 3 and/or the sulfurizing agent 4, depending on the characteristics of the charge.

Only the main steps, with the main flows, are shown in Figure 1, in order to allow a better understanding of the invention. It is understood that all the equipment necessary for operation is present (balloons, pumps, exchangers, ovens, columns, etc.), even if not shown. It is also understood that streams of hydrogen-rich gas (top-up or recycle), as described above, can be injected at the inlet of each reactor or catalytic bed or between two reactors or two catalytic beds. Means well known to those skilled in the art for purifying and recycling hydrogen can also be implemented. Recycling of the hydrocarbon cut comprising compounds having a boiling point above 150°C.

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

The recycle stream can supply said reaction stages in a single injection or can be divided into several fractions to supply the reaction stages in several injections, that is to say at the level of different catalytic beds when the reactors are bed reactors fixed.

Advantageously, the quantity of the recycle stream of the cut comprising compounds having a boiling point above 150° C. is adjusted so that the weight ratio between the recycle stream and the charge comprising a pyrolysis oil is that is to say the charge to be treated supplying the overall process, is less than or equal to 10, preferably less than or equal to 5, and preferably greater than or equal to 0.001, preferably greater than or equal to 0.01, and preferably greater than or equal to 0.1. Very preferably, the quantity of recycle stream is adjusted so that the weight ratio between the recycle stream and the charge comprising a pyrolysis oil is between 0.2 and 5.

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

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

According to another preferred variant, at least a fraction of the cut comprising compounds having a boiling point above 150° C. resulting from stage d) of fractionation is sent to a second stage of hydrocracking when it is present . The recycling of part of the cut comprising compounds having a boiling point above 150° C. towards or upstream of at least one of the reaction stages of the process according to the invention, and in particular towards stage b) d hydroconversion and/or to hydrocracking stages when they are present advantageously makes it possible to increase the yield of naphtha cut having a boiling point below 150°C. Recycling also makes it possible to dilute the impurities and, on the other hand, to control the temperature in the reaction step(s), in which reaction(s) involved can be highly exothermic.

A purge can be installed on the recycle of said cut comprising compounds with a boiling point above 150°C. Depending on the operating conditions of the process, said purge may be between 0 and 10% by weight of the cut comprising compounds having a boiling point above 150° C. relative to the incoming feed, and preferably between 0.5 % and 5%weight.

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

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

Advantageously, the quantity of the recycle stream, that is to say the fraction of product obtained that is recycled, is adjusted so that the weight ratio between the recycle stream and the charge comprising a pyrolysis oil, that is to say to say the load to be treated supplying the overall process, is less than or equal to 10, preferably less than or equal to 5, and preferably greater than or equal to 0.001, preferably greater than or equal to 0.01, and preferably greater than or equal to equal to 0.1. Very preferably, the quantity of recycle stream is adjusted so that the weight ratio between the recycle stream and the charge comprising a pyrolysis oil is between 0.2 and 5.

Advantageously, for the start-up phases of the process, a hydrocarbon cut external to the process can be used as recycle stream. A person skilled in the art will then know how to choose said hydrocarbon cut. The recycling of part of the product obtained towards or upstream of at least one of the reaction stages of the process according to the invention advantageously makes it possible on the one hand to dilute the impurities and on the other hand to control the temperature in the stage or stages. (s) reaction (s), in which (the) which (s) of the reactions involved can be strongly exothermic.

Said hydrocarbon effluent or said hydrocarbon stream(s) thus obtained by treatment according to the process of the invention of an oil from the pyrolysis of plastics and/or CSR, exhibit(s) a composition compatible with the specifications of an inlet feed of a steam cracking unit. In particular, the composition of the hydrocarbon effluent or of said hydrocarbon stream(s) is preferably such that:

- the total content of metallic elements is less than or equal to 10.0 ppm by weight, preferably less than or equal to 2.0 ppm by weight, preferably less than or equal to 1.0 ppm by weight and preferably less than or equal to 0, 5 ppm by weight, with: a content of the element silicon (Si) less than or equal to 5.0 ppm by weight, preferably less than or equal to 0.6 ppm by weight, and a content of the element iron (Fe) less than or equal to 200 ppb weight,

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

- the nitrogen content is less than or equal to 50 ppm by weight, preferably less than or equal to 50 ppm by weight and preferably less than or equal to 5 ppm by weight

- the asphaltene content is less than or equal to 5.0 ppm by weight,

- the total chlorine element content is less than or equal to 10 ppm by weight, preferably less than 1.0 ppm by weight,

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

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

The process according to the invention therefore makes it possible to treat the pyrolysis oils of plastics and/or CSR to obtain an effluent which can be injected, in whole or in part, into a steam cracking unit.

Analytical methods used

The analysis methods and/or standards used to determine the characteristics of the various streams, in particular of the feed to be treated and of the effluents, are known to those skilled in the art. In particular, they are listed below for information. others methods deemed equivalent may also be used, in particular IP, EN or ISO equivalent methods:

Table 1

(1) MAV method described in the article: C. Lôpez-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 , p. 57-68 EXAMPLE (in accordance with the invention)

Charge 1 treated in the process is a plastic pyrolysis oil having the characteristics indicated in Table 2.

Table 2: characteristics of the load Charge 1 is subjected to a step b) of hydroconversion carried out in an ebullated bed and in the presence of hydrogen 6, and of a catalyst of the NiMo type (1 wt% NiO and 6 wt% MoOa) on alumina under the conditions presented in table 3.

Table 3: conditions of stage b) of hydroconversion Effluent 7 from stage b) of hydroconversion is sent to stage c) of separation. A flow of water is injected upstream of stage c) of separation. The characteristics of effluent 11 (PI+) obtained after stage c) of separation are presented in Table 5.

Effluent 11 (PI+) is then sent to stage d) fractionation. Table 4 gives the yields of the various fractions obtained at the output of stage d) of fractionation, with respect to charge 1 at the input of the process chain.

Table 4: Yields of the various products and fractions obtained at the output of stage d) of fractionation

The H ₂ S and NH ₃ compounds are mainly eliminated in the form of salts in the aqueous phase eliminated in stage c) of separation. The characteristics of the PI-150°C and 150°C+ liquid fractions obtained after fractionation step d) are presented in Table 5: Table 5: characteristics of the PI-150°C and 150°C+ fractions after stage d) of fractionation and of the PI+ fraction after stage c) of separation

Effluent 11 (PI+) and liquid fractions 13 and 14 (PI-150°C and 150°C+) all three have compositions compatible with a steam cracking unit since: - they do not contain olefins (mono- and di-olefins);

- they have very low chlorine element contents below the limit required for a steam cracker charge;

- the metal contents, in particular iron (Fe), are also very low and below the limits required for a steam cracker charge (< 5.0 ppm by weight, very preferred <1 ppmw for metals; < 100 ppb weight for Fe);

- finally, they contain sulfur at levels well below the limits required for a steam cracker charge (<500 ppm by weight, preferably <200 ppm by weight for S and N). The PI-150°C and 150°C+ liquid fractions obtained are advantageously then sent to a steam cracking process.

Claims

55 CLAIMS

1. Process for treating a feed comprising an oil from the pyrolysis of plastics and/or solid recovered fuels, comprising: a) optionally, a selective hydrogenation step implemented in a reaction section fed at least by said feed and a gas stream comprising hydrogen, in the presence of at least one selective hydrogenation catalyst, at a temperature between 100 and 280°C, a partial pressure of hydrogen between 1.0 and 20.0 MPa abs. and an hourly volumetric speed between 0.3 and 10.0 h' ¹ , to obtain a hydrogenated effluent; b) a hydroconversion step implemented in a hydroconversion reaction section, implementing at least one bubbling bed, entrained bed and/or moving bed reactor, comprising at least one hydroconversion catalyst, said section hydroconversion reaction section being fed at least by said feed or by said hydrogenated effluent from step a) and a gas stream comprising hydrogen, said hydroconversion reaction section being implemented at a temperature between 300 and 450 ° C, a partial pressure of hydrogen between 5.0 and 20.0 MPa abs and an hourly volume rate between 0.03 and 2.0 h ^-1 , to obtain a hydroconverted effluent; c) a separation stage, supplied with the hydroconverted effluent from stage b) and an aqueous solution, said stage being carried out at a temperature between 20 and 450° C., to obtain at least one gaseous effluent, an aqueous effluent and a hydrocarbon effluent, d) optionally, a step of fractionating all or part of the hydrocarbon effluent from step c), to obtain at least one gaseous effluent and at least at least one hydrocarbon cut comprising compounds having a boiling point lower than or equal to 150°C and a hydrocarbon cut comprising compounds having a boiling point higher than 150°C.

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

3. Method according to one of the preceding claims, in which when step b) is carried out in an ebullated bed or in a moving bed, said hydroconversion catalyst of step b) comprises a supported catalyst comprising a metal from the group VIII chosen from the group formed by Ni, Pd, Pt, Co, Rh and/or Ru, optionally a group VIB metal chosen from the group Mo and/or W, on an amorphous mineral support chosen from the group 56 formed by alumina, silica, silica-aluminas, magnesia, clays and mixtures of at least two of these minerals, and when step b) is implemented in an entrained bed, said catalyst d The hydroconversion of step b) comprises a dispersed catalyst containing at least one element chosen from the group formed by Mo, Fe, Ni, W, Co, V, Ru.

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

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

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

7. Method according to one of the preceding claims, which further comprises a hydrotreatment step, said hydrotreatment step being carried out before or after step c) of separation, or even after step d) of fractionation, said hydrotreating step being implemented in a hydrotreating reaction section, implementing at least one fixed bed reactor having n catalytic beds, n being an integer greater than or equal to 1, each comprising at least one catalyst hydrotreating, said hydrotreating reaction section being supplied with at least part of said hydroconverted effluent from step b), or at least part of said hydrocarbon effluent from step c) or at least part of said hydrocarbon fraction comprising compounds having a boiling point above 150° C. resulting from step d) and a gas stream comprising hydrogen, said hydrotreating reaction section being implemented at a temperature between 250 and 430°C, a partial pressure of hydrogen between 1.0 and 57

20.0 MPa abs. and an hourly volumetric speed between 0.1 and 10.0 h' ¹ , to obtain a hydrotreated effluent.

8. Process according to the preceding claim, in which said hydrotreating catalyst comprises a support chosen from the group consisting of alumina, silica, silica-aluminas, magnesia, clays and mixtures thereof, and a hydro-dehydrogenating function. comprising at least one element from group VIII and/or at least one element from group VIB.

9. Process according to one of claims 7 to 8, which further comprises a hydrocracking step, said hydrocracking step being carried out either after a hydrotreating step, or after step d) of fractionation, said step hydrocracking being implemented in a hydrocracking reaction section, implementing at least one fixed bed having n catalytic beds, n being an integer greater than or equal to 1, each comprising at least one hydrocracking catalyst, said hydrocracking reaction section being supplied with at least a portion of said hydrotreated effluent and/or with the hydrocarbon fraction comprising compounds having a boiling point above 150° C. from stage d) and a gas stream comprising hydrogen, said hydrocracking reaction section being implemented at an average temperature between 250 and 450° C., a partial pressure of hydrogen between 1.5 and 20.0 MPa abs. and an hourly volume rate between 0.1 and 10.0 h ^-1 , to obtain a hydrocracked effluent.

10. Process according to claim 9, which further comprises a second hydrocracking step implemented in a hydrocracking reaction section, implementing at least one fixed bed having n catalytic beds, n being an integer greater than or equal to to 1, each comprising at least one hydrocracking catalyst, said hydrocracking reaction section being fed with a hydrocarbon cut comprising compounds having a boiling point above 150° C. resulting from the first hydrocracking stage and a stream gas comprising hydrogen, said hydrocracking reaction section being carried out at a temperature between 250 and 450°C, a partial pressure of hydrogen between 1.5 and 20.0 MPa abs. and an hourly volumetric speed between 0.1 and 10.0 h' ¹ , to obtain a hydrocracked effluent.

11. Process according to one of Claims 9 and 10, in which the said hydrocracking catalyst comprises a support chosen from halogenated aluminas, combinations of boron and aluminum oxides, amorphous silica-aluminas and zeolites and a hydro-dehydrogenating function comprising at least one metal from group VIB chosen from chromium, molybdenum and tungsten, alone or as a mixture, and/or at least one metal from group VIII chosen from iron, cobalt, nickel, ruthenium, rhodium, palladium and platinum. 58

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

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

14. Method according to one of the preceding claims, in which the filler has the following properties: