Pyrolysis oil treatment process including a pre-fractionation

Abstract

Process for treating a feedstock comprising a pyrolysis oil from plastics and / or tyres and / or solid recovered fuels, said process comprising the following steps: a) a pre-fractionation step of the feedstock to obtain a cut having a boiling point less than or equal to 120 °C and a cut having a boiling point greater than 120 °C containing olefins having 9 or more carbon atoms, b) a fluid catalytic cracking step carried out in a fluid catalytic cracking reaction section fed with at least said cut having a boiling point greater than 120 °C to produce propylene.

Description

[0001] PYROLYSIS OIL TREATMENT PROCESS INCLUDING PREFRACTIONATION

[0002] TECHNICAL FIELD

[0003] The present invention relates to the field of recycling plastics and / or tires and / or solid recovered fuels (SRF). More particularly, the present invention concerns a process for treating a feedstock comprising pyrolysis oil from plastics and / or tires and / or SRF, including, in particular, pre-fractionation of the feedstock to extract a heavy fraction with a boiling point above 120°C for transmission to a fluidized bed catalytic cracking stage. This pre-fractionation retains the C9+ olefins, precursors of propylene, in this heavy fraction while removing most of its impurities, thereby increasing the propylene yield in the fluidized bed catalytic cracking stage.

[0004] PREVIOUS TECHNIQUE

[0005] Plastics from collection and sorting streams, recycled tires, and solid recovered fuels (SRF) can undergo pyrolysis to recover their value. Pyrolysis involves heating a feedstock containing plastic and / or recycled tires and / or SRF, with or without a catalyst, in the absence of oxygen. This process leads to the formation of three main products: a liquid hydrocarbon phase at room temperature, also called pyrolysis oil; a light gas phase, also called pyrolysis gas; and a solid residue, also called char.

[0006] The liquid hydrocarbon phase, pyrolysis oil, can after fractionation be used in fuel storage units for gasoline, kerosene or diesel.

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

[0008] Another way to valorize pyrolysis oils is by using them as feedstock in fluidized bed catalytic cracking (FCC) units to produce olefins, particularly propylene. Such processes are described, for example, in US10442997, WO2021 / 133893, WO2021 / 133889, and WO2021 / 133895. Recent developments in FCC technology often focus on increasing propylene production at the expense of gasoline production, given the growing global demand for propylene.

[0009] However, pyrolysis oils often contain high levels of impurities, making them unsuitable for direct storage in fuel storage facilities or in steam cracking and FCC units, or downstream units such as polymerization and selective hydrogenation processes. These impurities can lead to operability issues, including corrosion (particularly due to the presence of chlorine), coking, catalytic deactivation, and incompatibility with the target polymers. The presence of diolefins can also cause pyrolysis oil instability, characterized by gum formation. Gums and other insolubles present in pyrolysis oil can lead to clogging problems in the processes.

[0010] One way to remove these impurities from pyrolysis oils of plastics and / or tires is to perform hydrotreatment (HDT) in the presence of catalysts. Such processes are described, for example, in WO2018 / 055555, WO2021 / 165178, and WO2022 / 144235. All these processes have in common that the entire pyrolysis oil is hydrotreated (without pre-fractionation).

[0011] However, the various impurities contained in pyrolysis oil, which we seek to eliminate, are generally found in different fractions of this oil. Indeed, depending on the origin of the pyrolysis oil, it can have a fairly wide range of boiling points (for example, between 40°C and 700°C). Some impurities, notably chlorine, silicon, and diolefins and monoolefins, are generally found in the lighter fraction of the oil (naphtha cut), while other impurities, such as sulfur, nitrogen, and metals, are more concentrated in the heavier fractions of the oil.

[0012] Thus, those skilled in the art are familiar with pyrolysis oil treatment processes involving pre-fractionation, allowing them to adapt the impurity removal treatment to the different fractions obtained after pre-fractionation. Pyrolysis oil treatment processes involving pre-fractionation of the pyrolysis oil are described, for example, in WO2018 / 069794, EP4108737, WO2022 / 034287, US2022 / 340824, and WO2022 / 144491.

[0013] All documents describing a pyrolysis oil processing method with prefractionation generally include fractionation of the pyrolysis oil into a naphtha cut and at least one heavier cut, the cut point of which is typically around 175 °C. The objective of this prefractionation is generally to obtain a naphtha cut for use as feedstock in a steam cracker. Indeed, compared to a heavier cut, the naphtha cut is more suitable for producing light olefins by steam cracking.

[0014] Thus, few documents describing a pyrolysis oil treatment process with pre-fractionation pay particular attention to the fate of the heavy fraction. This fraction is generally sent to hydrotreating and / or hydrocracking, steam cracking, or even to a FCC without any attempt to adapt it for the unit in question.

[0015] The present invention aims to improve this type of pyrolysis oil treatment process with pre-fractionation in order to obtain a heavy fraction suitable for FCC processing. The applicant has observed that by lowering the pre-fractionation cutting point to around 120°C, it is possible to retain the C9+ olefins, which are propylene precursors in the heavy fraction, while significantly reducing the impurities contained in this fraction. Indeed, thanks to pre-fractionation, certain impurities, particularly chlorine, silicon, and diolefins, which are especially harmful to the FCC unit, are more concentrated in the light fraction. The 120°C cutting point allows the 120°C+ fraction to retain the C9+ olefins, which have boiling points above 145°C, and in particular the C9 olefins, which are present in large quantities.Lowering the cut point compared to pre-fractionation carried out at a "classic" cut point around 175°C makes it possible in particular to keep the C9+ olefins in the "heavy" cut intended to be sent to FCC, which ultimately increases the propylene yield at the FCC outlet.

[0016] Pre-fractionation simultaneously allows obtaining a light cut which can be sent to refining for fuel production or to petrochemicals (steam cracking or catalytic reforming), often after having carried out at least one hydrogen treatment (selective hydrogenation, hydrogenation, hydrometallation, hydrotreating) in order to reduce its impurity content (particularly diolefins, olefins, sulfur, nitrogen, chlorine and silicon) to be compatible with these units.

[0017] SUMMARY OF THE INVENTION

[0018] More specifically, the invention relates to a process for treating a feed comprising a pyrolysis oil from plastic and / or tires and / or solid recovered fuels, said process comprising the following steps: a) a pre-fractionation step of the feed to obtain a cut having a boiling point less than or equal to 120°C and a cut having a boiling point greater than 120°C containing olefins having 9 or more carbon atoms, b) a catalytic fluidized bed cracking step carried out in a catalytic fluidized bed cracking reaction section in a substantially vertical reactor either in upstream or downstream mode in the presence of a zeolite catalyst at a reactor temperature between 450°C and 600°C, fed by at least said cut having a boiling point greater than 120°C to produce propylene.

[0019] According to one variant, the process according to the invention comprises at least one pretreatment step carried out on the feed before step a) of pre-fractionation or carried out on the cut having a boiling point less than or equal to 120°C or the cut having a boiling point greater than 120°C directly after step a) of pre-fractionation, said pretreatment step comprising an adsorption step and / or a filtration step and / or a centrifugation step and / or a decantation step and / or an electrostatic separation step and / or a washing step using an aqueous solution and / or a gas stripping step.

[0020] According to one variant, the fraction having a boiling point above 120°C, optionally pretreated, is subjected to a hydrotreating step before step b) of catalytic fluidized bed cracking, said hydrotreating step being carried out in a hydrotreating reaction section comprising at least one hydrotreating catalyst, said hydrotreating reaction section being fed at least by the fraction having a boiling point above 120°C and a gas stream comprising hydrogen, optionally pretreated, said hydrotreating reaction section being carried out at an average temperature between 100 and 250°C, a partial pressure of hydrogen between 1.0 and 5.0 MPa abs. and an hourly volumetric rate between 0.05 and 5 h -1 , the hydrogen blanket being between 5 and 200 Nm 3 of hydrogen per m 3of charge, to obtain a cut having a boiling point above 120°C partially hydrotreated.

[0021] According to one variant, said hydrotreating catalyst comprises a support selected from alumina, silica, silica-aluminas, magnesia, clays and mixtures thereof, and a hydro-dehydrogenating function comprising at least one element from group VIII and / or at least one element from group VIB.

[0022] According to one variant, the partially hydrotreated cut with a boiling point above 120°C is subjected to a separation step before step b) of catalytic cracking in a fluidized bed, advantageously implemented in at least one separation section, to obtain at least one gaseous effluent and a cut with a boiling point above 120°C partially freed of its impurities.

[0023] According to one variant, the separation step includes an injection of an aqueous solution.

[0024] According to one variant, the charge consists of pyrolysis oil from plastics and / or tires and / or solid recovered fuels.

[0025] According to one variant, a co-load chosen from a fossil feed and / or a feed from biomass conversion is introduced in step b) of catalytic fluidized bed cracking.

[0026] According to this variant, the fossil feedstock is chosen from among gasoline, diesel, vacuum diesel, atmospheric residues, vacuum residues, atmospheric distillates, vacuum distillates, heavy fuel oils, oils, waxes and paraffins, used oils, residues or deasphalted crudes, deasphalted oils, petroleum feedstocks from thermal or catalytic conversion processes, or mixtures of such feedstocks.

[0027] According to this variant, the feed from biomass conversion is chosen from vegetable oils, algae or algal oils, fish oils, used food oils, and fats of vegetable or animal origin; methyl esters of fatty acids of vegetable and / or animal origin, methyl esters of fatty acids from used food vegetable oils, feeds from thermal or catalytic biomass conversion processes, or mixtures of such feeds.

[0028] According to one variant, the cut having a boiling point less than or equal to 120°C is at least partly subjected to a steam cracking step carried out in at least one pyrolysis oven at a temperature between 700 and 900°C and at a pressure between 0.05 and 0.3 MPa relative in the presence of steam.

[0029] According to one variant, the cut having a boiling point less than or equal to 120°C is at least partially subjected to a catalytic reforming step in the presence of a reforming catalyst carried out at a temperature between 400 and 700°C, a pressure between 0.1 and 4 MPa and a mass flow rate of feed treated per unit mass of catalyst per hour between 0.1 and 10 h -1 .

[0030] In one variant, the fraction having a boiling point of 120°C or lower is at least partially introduced into a fuel storage unit. In another variant, the fraction having a boiling point of 120°C or lower is, prior to the steam cracking step, the catalytic reforming step, and / or its introduction into a fuel storage unit, subjected to at least one hydrorefining step.

[0031] According to one variant, the cut having a boiling point less than or equal to 120°C is introduced as a co-feed with a fossil feed and / or a feed from the conversion of biomass in a hydrotreating or hydrocracking process.

[0032] In the following text, "pyrolysis oil" refers to oil obtained from the pyrolysis of plastics and / or tires and / or RDF, unless otherwise specified. When the origin of the pyrolysis oil is important, its source is added (e.g., tire pyrolysis oil).

[0033] In the following text, the cup having a boiling point less than or equal to 120°C will also be called the 120°C- cup and the cup having a boiling point greater than 120°C will also be called the 120°C+ cup.

[0034] C9+ olefins are defined as olefins with 9 or more carbon atoms. C8- olefins are defined as olefins with 8 or fewer carbon atoms.

[0035] Monoolefins are defined as olefins containing one carbon-carbon double bond. Diolefins are defined as olefins containing two carbon-carbon double bonds.

[0036] 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 within the described range of values. If this were not the case and the limit values ​​were not included within the described range, this clarification will be provided by the present invention.

[0037] In this description, the term "include" is synonymous with (means the same as) "include" and "contain," and is inclusive or open-ended, not excluding other elements not mentioned. It is understood that the term "include" includes the exclusive and closed term "consist."

[0038] In the context of the present invention, the various parameter ranges for a given step, such as pressure ranges and temperature ranges, can be used alone or in combination. For example, in the context of the present invention, a preferred pressure range can be combined with a preferred temperature range. Specific and / or preferred embodiments of the invention may be described below. These may be implemented separately or in combination, without limitation as to whether they can be combined, when technically feasible.

[0039] In what follows, the groups of chemical elements are given according to the CAS classification (CRC Handbook of Chemistry and Physics, publisher CRC press, editor-in-chief DR Lide, 81 èmeedition, 2000-2001). For example, group VIII (or VI 11 B) according to the CAS classification corresponds to the metals of columns 8, 9 and 10 according to the new IIIPAC classification.

[0040] The metal content is measured by X-ray fluorescence.

[0041] DETAILED DESCRIPTION

[0042] The charge

[0043] According to the invention, the charge comprises a pyrolysis oil of plastic and / or tire and / or solid recovered fuels.

[0044] Plastic waste is generally a mixture of several polymers. It can include polyethylene (low and / or high density), polypropylene, polyethylene terephthalate, polyvinyl chloride, and polystyrene, either alone or in mixtures. Furthermore, depending on its use, plastics may contain, in addition to polymers, other compounds such as plasticizers, pigments, dyes, or residues of polymerization catalysts. Plastic waste may also contain, in small quantities, biomass originating, for example, from household waste.

[0045] As for tires, they are mainly made of rubber for their elastic properties (a mixture of elastomers such as natural and synthetic cross-linked rubbers, with added additives such as silica, resin, sulfur, zinc oxide, carbon black, etc.) and textile and metallic fibers for their reinforcing properties.

[0046] Solid recovered fuels (SRF), also known as refuse derived fuel (RDF) or solid recovered fuels (SRF) in English, are non-hazardous solid wastes prepared for energy recovery. These wastes originate from household and similar waste, waste from economic activities, or construction and demolition waste. SRF is generally a mixture of various combustible waste materials, such as used tires, food by-products (fats, animal meal, etc.), viscose and wood waste, light fractions from shredders (e.g., end-of-life vehicles), waste electrical and electronic equipment (WEEE), household and commercial waste, and recycling residues from various types of waste, including certain municipal waste, plastics, textiles, and wood, among others. SRF typically contains plastic waste.

[0047] The pyrolysis oil included in the feed, whether it comes from tires, plastics and / or RDF, comes from a pyrolysis step of a feed containing tires, plastic(s) and / or RDF in a pyrolysis unit.

[0048] The pyrolysis step can be carried out by a thermal pyrolysis treatment, catalytic or even be prepared by hydropyrolysis (pyrolysis in the presence of a catalyst and hydrogen).

[0049] The pyrolysis step is generally carried out at a temperature between 250°C and 750°C. The pyrolysis step can be performed under varying degrees of severity. The low-severity pyrolysis step is carried out at a temperature between 250°C and 450°C, preferably between 275°C and 425°C, and particularly preferably between 300°C and 400°C. The low-severity pyrolysis step produces pyrolysis oils rich in mono- and diolefins, as well as a significant amount of aromatics, which may include chlorinated compounds.

[0050] The high-severity pyrolysis step is carried out at a temperature between 450°C and 750°C, preferably between 500°C and 700°C, and particularly preferably between 550°C and 650°C. The high-severity pyrolysis step produces pyrolysis oils rich in aromatics, which may include chlorinated compounds.

[0051] The pyrolysis unit may include one or more reactors configured to convert the feed into gaseous and liquid-phase products (for example, simultaneously). The reactor(s) may contain one or more beds of inert materials or pyrolysis catalysts, including sand, zeolite, or combinations thereof. Typically, the pyrolysis catalyst is capable of transferring heat to the components undergoing pyrolysis within the pyrolysis unit.

[0052] The pyrolysis unit may include one or more pieces of equipment, for example one or more heated extruders, a heated rotary kiln, heated tank-type reactors, empty heated containers, enclosed heated surfaces where the charge flows along the wall, containers surrounded by kilns, or other equipment providing a heated surface.

[0053] In one or more embodiments of the pyrolysis unit, a purge gas is used in all or part of the pyrolysis stage(s) to enhance plastic cracking, produce valuable products, provide feed for steam cracking, or combinations thereof. The purge gas may comprise hydrogen (H2), nitrogen (N2), steam, product gases, or combinations thereof.

[0054] Pyrolysis oil, whether derived from tires, plastics and / or RDF, generally has a boiling point range of 40°C to 1000°C, preferably between 45°C and 650°C, preferably between 45°C and 550°C.

[0055] The density of pyrolysis oil, whether derived from tires, plastics, and / or RDF, generally ranges from 0.75 to 1.05 g / cm³ when measured at 15°C according to ASTM D4052. 3 , preferably between 0.75 and 0.95 g / cm³ 3.

[0056] Pyrolysis oil, advantageously in liquid form at ambient temperature, comprises in particular a mixture of hydrocarbon compounds, notably paraffins (n- and i-paraffins), olefins (mono- and / or diolefins), naphthenes, and aromatics. Specifically, depending on the origin of the feedstock processed by the pyrolysis unit, the pyrolysis oil may comprise up to 70% by weight of paraffins, up to 90% by weight of naphthenes, up to 90% by weight of olefins, and up to 90% by weight of aromatics, it being understood that the sum of the paraffins, naphthenes, olefins, and aromatics equals 100% by weight of the hydrocarbon compounds.

[0057] Pyrolysis oil may contain diolefins. The diolefin content is commonly determined indirectly as the maleic anhydride value (MAV). The method is based on the Diels-Alder addition reaction between conjugated diolefins and maleic anhydride. The method for determining MAV is described in C. López-Garcia et al., "Near Infrared Monitoring of Low Conjugated Diolefins Content in Hydrotreated FCC Gasoline Streams," Oil & Gas Science and Technology - Rev. IFP, Vol. 62 (2007), No. 1, pp. 57-68. MAV is expressed as mg of maleic anhydride that reacted with 1 g of sample (mg / g). MAV varies between 5 and 100 mg / g in pyrolysis oils.

[0058] Pyrolysis oil, whether derived from tires, plastics, and / or RDF (Refuse-Derived Fuel), may contain some compounds of biological origin. For example, tire pyrolysis oil is produced from natural rubber elastomers, while plastic and / or RDF pyrolysis oil is produced from plastic and / or RDF waste and may contain, to a lesser extent, biomass from sources such as household waste. The biological carbon content (according to the radiocarbon dating method) is determined by the analytical method of carbon-14. 14 (according to ASTM D6866) may be between 0 and 70% by weight, preferably between 0.1 and 60% by weight relative to the total weight of the pyrolysis oil. In the case of tire pyrolysis oil, it may include a biological carbon content (according to the radiocarbon analytical method of carbon-14). 14(according to ASTM D6866) comprising between 20 and 70% by weight, preferably between 30 and 60% by weight relative to the total weight of the pyrolysis oil. This allows for the incorporation of a biological composition into the products of the process according to the invention.

[0059] Pyrolysis oil can contain, and most often does, impurities such as metals, particularly iron and silicon, and halogenated compounds, especially chlorinated compounds. These impurities can be present at high levels, for example up to 500 ppm by weight, or even 700 ppm by weight, 1000 ppm by weight, or even 5000 ppm by weight, of halogenated elements (particularly chlorine, but also bromine, fluorine, or iodine) supplied by halogenated compounds, and generally between 1 and 1000 ppm by weight, or between 1 and 700 ppm by weight, or between 1 and 500 ppm by weight of halogenated elements. Pyrolysis oil can contain up to 500 ppm by weight or even 700 ppm by weight or even 1000 ppm by weight and even 5000 ppm by weight of chlorine element supplied by chlorinated compounds, and generally between 1 and 1000 ppm by weight or between 1 and 700 ppm by weight or between 1 and 500 ppm by weight of chlorine element.Pyrolysis oil can contain up to 50 ppm by weight or even 100 ppm by weight of bromine element supplied by brominated compounds, and generally between 1 and 100 ppm by weight or between 1 and 50 ppm by weight of bromine element.

[0060] The oil may contain up to 200 ppm by weight, or even 1500 ppm by weight, of metallic or semi-metallic elements, and generally between 1 and 200 ppm by weight or between 1 and 1500 ppm by weight of metallic or semi-metallic elements. Alkali metals, alkaline earth metals, transition metals, post-transition metals, and metalloids can be considered contaminants of a metallic nature, referred to as metallic or semi-metallic metals or elements. In particular, metallic or semi-metallic metals or elements include silicon, iron, or both. Pyrolysis oil may contain up to 200 ppm by weight or even 1000 ppm by weight of silicon, and generally between 1 and 200 ppm by weight, or between 1 and 1000 ppm by weight, or between 1 and 500 ppm by weight of silicon. Pyrolysis oil may include up to 50 ppm by weight or 100 ppm by weight of iron, and generally between 1 and 50 ppm by weight or between 1 and 100 ppm by weight of iron.Pyrolysis oil may also include phosphorus, sodium, calcium, potassium, and magnesium.

[0061] Pyrolysis oil may also contain other impurities such as heteroatoms, notably sulfur compounds, oxygenated compounds, and / or nitrogenous compounds, at levels generally below 40,000 ppm by weight of heteroatoms and preferably below 15,500 ppm by weight of heteroatoms, and generally between 1 and 40,000 ppm by weight or between 1 and 15,500 ppm by weight of heteroatoms. Sulfur compounds are generally present at a level below 15,000 ppm by weight and preferably below 10,000 ppm by weight, and generally between 1 and 15,000 ppm by weight or between 1 and 10,000 ppm by weight of sulfur compounds.

[0062] Oxygenated compounds are generally present in a content of less than 15000 ppm by weight and preferably less than 10000 ppm by weight, and generally between 1 and 15000 ppm by weight or between 1 and 10000 ppm by weight of oxygenated compounds.

[0063] Nitrogen compounds are generally present in a content of less than 10000 ppm by weight and preferably less than 5000 ppm by weight, and generally between 1 and 10000 ppm by weight or between 1 and 5000 ppm by weight of nitrogen compounds.

[0064] The levels of sulfur, oxygen, and / or nitrogen compounds often depend on the origin of the processed material. Thus, pyrolysis oils from tires generally contain more heteroatoms than pyrolysis oils from plastics, particularly sulfur compounds.

[0065] Pyrolysis oil may also include other impurities such as heavy metals like mercury, arsenic, zinc and lead, for example up to 100 ppb by weight or 200 ppb by weight of mercury or arsenic, and usually between 1 and 200 ppb by weight or between 1 and 100 ppb by weight of heavy metals.

[0066] The feedstock for the process according to the invention comprises at least one pyrolysis oil derived from plastic and / or tires and / or solid recovered fuels, in any proportion. This feedstock may consist solely of pyrolysis oil(s). Preferably, this feedstock comprises at least 50% by weight, and more preferably between 70% and 100% by weight, of pyrolysis oil relative to the total weight of the feedstock, i.e., preferably between 50% and 100% by weight, and more preferably between 70% and 100% by weight of pyrolysis oil. Preferably, the feedstock consists of a pyrolysis oil derived from plastic and / or tires and / or solid recovered fuels.

[0067] The feed of the process according to the invention may further comprise, at a low content, typically between 1% and 50% by weight of the feed, or even between 1% and 30% or between 1% and 10% by weight, in addition to the pyrolysis oil, a conventional petroleum feed or a feed from biomass conversion which is then co-treated with the pyrolysis oil of the feed.

[0068] The conventional petroleum feedstock may advantageously be a cut or a blend of cuts of the naphtha, gas oil, or vacuum gas oil type. The feedstock derived from biomass conversion may advantageously be selected from vegetable oils, algae or algal oils, fish oils, used cooking oils, and fats of vegetable or animal origin; or blends of such feedstocks. These vegetable oils may advantageously be crude or refined, wholly or partially, and derived from plants selected from rapeseed, sunflower, soybean, palm, olive, coconut, copra, castor, cottonseed, peanut, linseed, and crambe oils, and all oils derived, for example, from sunflower or rapeseed by genetic modification or hybridization; this list is not exhaustive.These animal fats are advantageously chosen from lard and fats composed of residues from the food industry or from the catering industry. Frying oils, various animal oils such as fish oil, tallow, and lard can also be used. The feedstock resulting from biomass conversion can also advantageously be chosen from methyl esters of fatty acids of vegetable and / or animal origin, or from methyl esters of fatty acids from used edible vegetable oils.

[0069] The feedstock resulting from biomass conversion can also be selected from feedstocks produced by thermal or catalytic biomass conversion processes, such as oils derived from biomass, particularly lignocellulosic biomass, using various liquefaction methods, such as hydrothermal liquefaction or pyrolysis. The term "biomass" refers to material derived from recently living organisms, including plants, animals, and their byproducts. "Lignocellulosic biomass" refers to biomass derived from plants or their byproducts. Lignocellulosic biomass is composed of carbohydrate polymers (cellulose, hemicellulose) and an aromatic polymer (lignin).

[0070] The feedstock from biomass conversion can also advantageously be chosen from feedstocks from the paper industry.

[0071] Pre-treatment step (optional)

[0072] The process according to the invention may include a pretreatment step carried out on the feed before step a) of pre-fractionation or carried out on the cut having a boiling point less than or equal to 120°C or the cut having a boiling point greater than 120°C directly after step a) of pre-fractionation.

[0073] Thus, according to the embodiment of carrying out the pretreatment before step a) of prefractionation, the feed comprising a pyrolysis oil can advantageously be pretreated in an optional pretreatment step, to obtain a pretreated feed that feeds step a) of prefractionation.

[0074] Depending on the embodiment of carrying out the pretreatment after step a) of prefractionation, the 120°C+ slice from the prefractionation step can advantageously be pretreated in an optional pretreatment step to obtain a pretreated 120°C+ slice which feeds into step b) of fluidized bed catalytic cracking (FCC).

[0075] The pretreatment step can also be carried out before and after step a) prefractionation and before step b) FCC. In this case, the feed containing pyrolysis oil is pretreated before prefractionation, then the 120°C+ cut is pretreated a second time before being introduced into the FCC; the pretreatment can be the same as or different from the first.

[0076] The pretreatment step can also be performed on the 120°C- slice. When the pretreatment step is performed on the 120°C- slice, it is carried out independently of the pretreatment step on the 120°C+ slice.

[0077] According to one variant, this optional pretreatment step reduces the amount of contaminants and solid particles. This optional pretreatment step specifically allows for the removal of sediments that can form due to the instability of pyrolysis oils and / or compatibility issues between two different feedstocks.

[0078] This optional pretreatment step can be implemented by any method known to those skilled in the art that reduces the quantity of contaminants. It may include, in particular, an adsorption step and / or a filtration step and / or a centrifugation step and / or a settling step and / or an electrostatic separation step and / or a washing step using an aqueous solution and / or a gas stripping step.

[0079] The optional pretreatment step is advantageously carried out at a temperature between 20 and 400°C, preferably between 40 and 350°C, and at a pressure between 0.15 and 10.0 MPa abs, preferably between 0.2 and 7.0 MPa abs.

[0080] According to one variant, the optional pretreatment step is carried out in an adsorption section operated in the presence of at least one adsorbent. The adsorbent can be chosen from zeolite, activated carbon, clay, silica, or alumina.

[0081] Advantageously, the adsorbent comprises less than 1% by weight of metallic elements and is preferably free of metallic elements. Metallic elements of the adsorbent are understood to mean elements of groups VI B, VII B, and VIII. According to another variant, the optional pretreatment step is carried out in a washing section with an aqueous solution, for example, water, an acidic or basic solution, or an organic solvent. This washing section may include equipment for contacting the feed, or the 120°C+ or 120°C- fraction obtained after pre-fractionation, with the aqueous solution and separating the phases to obtain the pretreated feed or fraction on the one hand, and the aqueous solution containing impurities on the other. This equipment may include, for example, a stirred reactor, a decanter, a mixer-decanter, and / or a co-current or counter-current washing column.

[0082] According to another variant, the optional pretreatment step is implemented by filtration. The filtration step removes inorganic solids, sediments, and / or fines contained in the feed, or in the 120°C+ or 120°C- fraction obtained after pre-fractionation, including metals, metal oxides, and metal chlorides. A filter with a pore size (e.g., diameter or equivalent diameter) of less than 25 pm is generally used, preferably less than or equal to 10 pm, and even more preferably less than or equal to 5 pm. Alternatively, a series of filters with different pore sizes can be used, including a series of filters with decreasing pore sizes in the direction of feed flow. These filter media are well-known for industrial applications. Cartridge filters and self-cleaning filters are suitable examples.

[0083] According to one variant, filtration aids, for example diatomaceous earth, can be used in the filtration system, either as seeding, i.e. in suspension in the load or as a pre-coat on the filter.

[0084] Regardless of the type of filters, especially those with additives, two filters can be used in parallel to perform cleaning and maintenance on one, while the other is in operation.

[0085] According to another variant, the said optional pretreatment step is implemented by centrifugation, decantation or electrostatic separation.

[0086] According to another variant, the optional pretreatment step is implemented by gas stripping, thereby reducing the oxygen content. Gas stripping can remove oxygen (O2) that may be dissolved in the feed, or the 120°C+ or 120°C- cut obtained after pre-fractionation, thus reducing the likelihood of free radical formation leading to polymerization in downstream steps. The process generally involves contacting the feed, or the 120°C+ or 120°C- cut obtained after pre-fractionation, with a stripping gas (e.g., H2, N2, or a mixture thereof), thereby transferring at least some of the dissolved oxygen from the feed or cut to the stripping gas, followed by separation of the stripping gas from the feed or cut.

[0087] This optional pretreatment step generally includes one or more, preferably several, of the treatments described above.

[0088] The pretreatment does not include a hydrorefining step using hydrogen to remove impurities.

[0089] Step a) of pre-fractionation

[0090] The process according to the invention includes a step a) of pre-fractionating the charge to obtain a cut having a boiling point less than or equal to 120°C (or 120°C- cut) and a cut having a boiling point greater than 120°C containing olefins having 9 or more carbon atoms (or 120°C+ cut).

[0091] A "cut with a boiling point above 120°C" is defined as a hydrocarbon cut comprising compounds with a boiling point generally above 120°C, particularly between 120 and 1000°C, preferably between 120 and 650°C, and more preferably between 120 and 550°C. This cut may include heavy naphtha and middle distillates such as diesel and / or kerosene. It may also include heavier compounds such as vacuum gas oil (VGO). Kerosene typically has initial and final boiling points in the range of approximately 175 to 250°C, and diesel typically has initial and final boiling points in the range of approximately 250°C to 370°C. As for vacuum diesel, it generally has boiling points above 370°C.

[0092] The term "cut having a boiling point less than or equal to 120°C" refers to a hydrocarbon cut comprising compounds having a boiling point generally less than or equal to 120°C, particularly between 45 and 120°C. This cut notably includes light naphtha (boiling ranges between 45 and 80 °C) and a portion of heavy naphtha (boiling range between 80 and 175 °C).

[0093] The person skilled in the art understands that the cutting point of 120°C is a cutting point around 120°C with a variation of ± 10 °C.

[0094] Choosing a cutting point around 120°C also helps preserve the C9+ olefins in the 120°C+ cut, which generally have a boiling point of at least 145°C. C9+ olefins, and especially the C9 olefins present in large quantities in this cut, are precursors of the propylene produced by fluidized bed catalytic cracking. Their presence in the 120°C+ cut thus increases the propylene yield during the FCC step.

[0095] The pre-fractionation step is advantageously carried out at a pressure less than or equal to 1.0 MPa abs., preferably between 0.1 and 1.0 MPa abs.

[0096] The pre-fractionation step can advantageously be carried out by any method known to those skilled in the art, such as, for example, a combination of one or more separators (flasks), and / or one or more stripping columns, and / or a distillation column, these separators (flasks) and / or columns optionally being supplied with a stripping gas, for example, a hydrogen-rich gas stream. Preferably, the pre-fractionation step uses a distillation column.

[0097] The impurities in the initial pyrolysis oil are not distributed evenly in the different fractions after pre-fractionation. The 120°C- fraction generally contains the majority of diolefins, light monoolefins (C8-), chlorinated compounds, and silica compounds. The 120°C+ fraction, on the other hand, generally contains few or no diolefins. Furthermore, it generally contains fewer chlorinated and silica compounds than the 120°C- fraction. However, sulfur and / or nitrogen-based impurities are generally concentrated in the 120°C+ fraction.

[0098] Pre-fractionation thus allows the majority of impurities harmful to an FCC to be concentrated in the 120°C- cut to obtain a 120°C+ cut free of most impurities (chlorinated compounds, silicon, monoolefins and diolefins) so that it can preferably be sent without any further treatment to the FCC unit.

[0099] Chlorine is indeed generally the limiting contaminant for treating pyrolysis oils in existing FCC units. Chlorine, even at low concentrations (< 10 or even < 5 ppm w / w), is responsible for corrosion (in the form of HCl) that can occur in existing units whose metallurgy is generally not designed to withstand chlorine levels exceeding 10 or even 5 ppm w / w in the feed.

[0100] The other impurities contained in the 120°C+ fraction (sulfur, metals, nitrogen, etc.) are less critical for introduction into a FCC unit. The remaining impurities will be converted or removed in downstream FCC units, as the residual impurity levels are generally compatible with these units. Depending on the residual impurity levels, particularly halogenated compounds (chlorine), the 120°C+ fraction from pre-fractionation step a) may therefore have a composition suitable for direct introduction into an FCC unit.

[0101] According to another embodiment, the 120°C+ cut can undergo pretreatment as described above.

[0102] According to another embodiment, the 120°C+ cut can undergo a hydrotreatment step followed by a separation step as described below.

[0103] According to another embodiment, the 120°C+ cut can undergo pretreatment followed by a hydrotreatment step and a separation step as described above.

[0104] Pretreatment and / or hydrotreatment followed by a separation step is / are carried out in particular when the content of impurities, in particular halogenated compounds, is too high for direct introduction into step b) of FCC.

[0105] According to another embodiment, when the impurity content, particularly halogenated compounds, is too high for direct introduction into step b) of FCC, the 120°C+ cut can be introduced as a co-feed with a fossil feed and / or a feed from biomass conversion in step b) of FCC. Indeed, when the chlorinated compound content is greater than 10 ppm, or even 5 ppm by weight, in the 120°C+ cut, a chlorine content below 10 ppm, or even 5 ppm, can be achieved by dilution at the inlet of the FCC unit with a fossil feed and / or a feed from biomass conversion.

[0106] According to another embodiment, the 120°C+ cut can be introduced as a co-feed with a fossil feed and / or a feed from biomass conversion in step b) of FCC even if the 120°C+ cut has a composition compatible (low levels of impurities in halogenated compounds, in particular chlorine) to be introduced directly into an FCC unit.

[0107] Step d) Gentle hydrotreatment (optional)

[0108] After pre-fractionation, and after possible pretreatment, the 120°C+ cut can undergo a hydrotreatment step followed generally by a separation step before being sent to the FCC unit.

[0109] The hydrotreatment step is a mild hydrotreatment which notably reduces the content of halogenated compounds, and in particular chlorine, of the 120°C+ cut in order to obtain a cut free of most of the halogenated compounds and which can then be sent alone or as a co-feed with fossil feedstocks and / or feedstocks from biomass conversion in step b) of FCC.

[0110] "Gentle" hydrotreating is hydrotreating carried out under carefully chosen pressure, temperature, and flow rate conditions, generally more moderate than conventional hydrotreating methods known in the prior art, which aim to remove all impurities. The hydrotreating method of the present invention, in particular, allows for the significant removal of halogenated compounds while preserving olefins as much as possible.

[0111] The hydrotreating step is primarily focused on removing halogenated compounds to make the 120°C+ cut compatible as feedstock in downstream FCC units. The hydrotreating step does not aim for complete hydrotreating of the 120°C+ cut. Other impurities contained in the 120°C+ cut (metals, silicon, nitrogen, etc.) are not necessarily completely removed during the hydrotreating step, although the operating conditions allow for the removal of at least some of them. Thus, partial hydrogenation of aromatics, hydrodesulfurization and hydrodeazotation, as well as partial hydrogenation of monoolefins and diolefins (although the goal is to retain them in the cut), are also observed. The remaining impurities will eventually be converted or removed in the downstream FCC units, as the residual impurity levels are compatible with these units.

[0112] The hydrotreating step of the 120°C+ cut is carried out in a hydrotreating reaction section comprising at least one hydrotreating catalyst, said hydrotreating reaction section being fed at least by the 120°C+ cut and a gas stream comprising hydrogen, said hydrotreating reaction section being carried out at an average temperature between 100 and 250°C, a partial pressure of hydrogen between 1.0 and 5.0 MPa abs. and an hourly volumetric rate between 0.05 and 5 h -1 , the hydrogen blanket being between 5 and 200 Nm 3 of hydrogen per m 3 of charge, to obtain a 120°C+ partially hydrotreated cut having hydrocarbon compounds with a reduced halogen content compared to the 120°C+ non-hydrotreated cut.

[0113] The said hydrotreating reaction section is advantageously implemented at a mean average temperature (or WABT as defined below) of hydrotreating between 100 and 250°C, preferably between 110 and 230°C, preferably between 120 and 210°C, at a partial pressure of hydrogen between 1.0 and 5.0 MPa abs., preferably between 1.0 and 4 MPa abs., preferably between 1.2 and 3 MPa abs., and at a volumetric flow rate per hour (WH) between 0.1 and 5 h -1 preferably between 0.1 and 2 hours -1 , preferably between 0.1 and 1.0 h -1 The hydrogen coverage in the hydrotreating stage is advantageously between 5 and 200 Nm 3 of hydrogen per m 3 load, and preferably between 10 and 100 Nm 3 of hydrogen per m 3 load, preferably between 15 and 50 Nm 3 of hydrogen per m 3 dump.

[0114] According to the invention, the "average temperature" of a reaction section corresponds to the Weight Average Bed Temperature (WABT), a term well known to those skilled in the art. The average temperature is advantageously determined based on the catalytic systems, equipment, and their configuration used. The average temperature (or WABT) is calculated as follows:

[0115] WABT = (Tgijjig, + TæifigJS) where Tinlet: the temperature of the flow at the inlet of the reaction section and Toutlet: the temperature of the effluent at the outlet of the reaction section. Unless otherwise specified, the "average temperature" of a reaction section is given at the start of the cycle.

[0116] The hourly volumetric velocity (WH) is defined here as the ratio between the hourly volumetric flow rate of the charge (120°C+ cut), possibly pre-treated, and the volume of catalyst(s).

[0117] Hydrogen coverage is defined as the ratio of the volumetric flow rate of hydrogen under standard temperature and pressure conditions to the volumetric flow rate of the "fresh" feed, i.e., the 120°C+ cut, possibly pretreated, without taking into account a recycled fraction or a gaseous diluent (recycled hydrogen), at 15°C (under standard conditions). 3 , noted Nm 3 , of H2par m 3 dump).

[0118] The hydrogen-containing gas stream that feeds the hydrotreating reaction section can consist of fresh hydrogen and / or recycled hydrogen. Preferably, an additional hydrogen-containing gas stream is advantageously introduced at the inlet of each reactor, particularly those operating in series, and / or at the inlet of each catalytic bed from the second catalytic bed in the reaction section. These additional gas streams are also called cooling streams. They allow for temperature control in the reactor, where the reactions carried out are generally highly exothermic. The hydrogen-containing gas stream can originate from a fossil fuel source or a renewable source, for example, from the gasification of plastic waste or produced by electrolysis.

[0119] Preferably, the hydrotreating step is implemented in a hydrotreating reaction section, employing at least one fixed-bed reactor having n catalytic beds, n being an integer greater than or equal to 1, preferably between one and ten, preferably between two and five, each comprising at least one hydrotreating catalyst.

[0120] The hydrotreating reaction section employing at least one fixed-bed reactor can operate with downward or upward flow of gas and liquid.

[0121] Advantageously, the reaction section of said hydrotreating step comprises between 1 and 5 reactors, preferably between 2 and 5 reactors, and particularly preferably comprises two reactors. The advantage of a hydrotreating reaction section comprising several reactors lies in optimized feedstock treatment, while reducing the risk of clogging and / or deactivation of the catalytic bed(s), and thus avoiding excessively frequent unit shutdowns due to clogging and / or deactivation.

[0122] In one embodiment, the hydrotreating reaction section comprises two reactors operating in a switchable mode, known as a "Permutable Reactor System" (PRS) or "lead and lag" system. Combining at least two reactors in PRS mode allows one reactor to be isolated, the spent catalyst to be discharged, the reactor to be refilled with fresh catalyst, and the reactor to be restarted without interrupting the process. The PRS technology is described, in particular, in patent FR2681871.

[0123] According to another embodiment, 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, preferably between two and five.

[0124] Advantageously, reactor internals, for example filter trays, can be used to prevent clogging of the reactor(s). An example of a filter tray is described in patent FR3051375. Any reaction section employing at least one fixed-bed reactor can operate with either a downward or upward flow of gas and liquid, preferably with a downward flow.

[0125] To control the highly exothermic reactions in this reaction section, a liquid and / or gaseous diluent (also called a quench) can be injected. This allows for the dilution of impurities and temperature control. The liquid diluent (or liquid quench) can be an external liquid (e.g., a fossil naphtha fraction) or internal to the process. Preferably, the liquid diluent is a portion of the C120°C+ fraction obtained in the separation (recycle) step. The gaseous diluent (or gaseous quench) is generally a gas stream containing fresh and / or recycled hydrogen. Preferably, the gaseous diluent is at least a portion of the gaseous effluent obtained in the separation (recycle) step performed after the hydrotreating step, which contains hydrogen, possibly purified.

[0126] Preferably, the hydrotreating step may implement upstream of the hydrotreating catalyst(s) at least one guard bed containing adsorbents of the type alumina, silica, silica-alumina, zeolite and / or activated carbon possibly containing metals of group VIB and / or VIII. A series of guard beds with particles of different diameters may also be used, in particular a series of guard beds having diameters decreasing in the direction of the flow of the feed (also called "grading" according to Anglo-Saxon terminology).

[0127] Advantageously, said hydrotreating catalyst comprises a support, preferably mineral, and a hydro-dehydrogenating function.

[0128] According to one variant, the hydro-dehydrogenating function comprises, in particular, at least one element from Group VIII, preferably selected from nickel and cobalt, and at least one element from Group VIB, preferably selected from molybdenum and tungsten. According to this variant, the total content, expressed as oxides of the metallic elements from Groups VIB and VIII, is preferably between 1% and 40% by weight, and preferably between 5% and 30% by weight, relative to the total weight of the catalyst. When the metal is cobalt or nickel, the metal content is expressed as CoO and NiO, respectively. When the metal is molybdenum or tungsten, the metal content is expressed as MoChet WO3, respectively. The catalyst generally comprises a content of group VIII elements of between 0.5% and 12% by weight (expressed as oxide) and a content of group VIB elements of between 0.5% and 28% by weight (expressed as oxide) relative to the weight of the catalyst.The weight ratio expressed in metal oxide between the metal (or metals) of group VI B and the metal (or metals) of group VIII is preferably between 1 and 20, and preferably between 2 and 10.

[0129] According to this variant, the reaction section of said hydrotreating step comprises, for example, a hydrotreating catalyst comprising between 0.5% and 12% by weight of nickel, preferably between 0.9% and 10% by weight of nickel (expressed as nickel oxide NiO relative to the weight of said catalyst), and between 1% and 30% by weight of molybdenum, preferably between 3% and 20% by weight of molybdenum (expressed as molybdenum oxide MoOa relative to the weight of said catalyst) on a support, preferably mineral, preferably on an alumina support.

[0130] The catalyst may contain phosphorus and boron. When phosphorus pentoxide (P₂O₅) is present, its content is between 0.001 and 10% by weight relative to the weight of the catalyst. When boron trioxide (B₂O₃) is present, its content is between 0.001 and 10% by weight relative to the weight of the catalyst.

[0131] It may also further comprise one or more organic compounds containing oxygen and / or nitrogen and / or sulfur, such a catalyst often being referred to as an "additized catalyst".

[0132] 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 variant, the nickel oxide content is preferably between 1 and 50% by weight, preferably between 10% and 30% by weight relative to the weight of the catalyst. This type of catalyst is preferably used in its reduced form, on a support that is preferably mineral, preferably an alumina support.

[0133] The support for said hydrotreating catalyst is preferably selected from alumina, silica, silica-aluminas, magnesia, clays, and mixtures thereof. This support may contain dopant compounds, in particular oxides selected from boron oxide, especially boron trioxide, zirconia, cerium, titanium dioxide, phosphoric anhydride, and mixtures thereof. Preferably, said hydrotreating catalyst comprises an alumina support. The alumina used may, for example, be gamma (γ) or eth (β) alumina.

[0134] The hydrotreating catalyst is, for example, in the form of extrudates or beads. Preferably, the hydrotreating step may also employ, in addition to the hydrotreating catalyst(s) described above, at least one low-concentration hydrotreating catalyst comprising between 0.1 and 1 wt% nickel (expressed as oxide), preferably between 0.5 and 1 wt% nickel, and between 0.1 and 5 wt% molybdenum (expressed as oxide), preferably between 0.5 and 1 wt% molybdenum, relative to the weight of the catalyst, on an alumina support. This low-concentration catalyst may preferably be placed upstream or downstream of the hydrotreating catalyst(s) described above, preferably upstream.

[0135] The preparation of the catalyst for the hydrotreating step is well-established and generally includes an impregnation step with Group VIII and Group VI B metals (when present), and possibly phosphorus and / or boron on the support, followed by drying and then possibly calcination. The catalyst for the hydrotreating step may also be a catalyst used in its reduced form, thus requiring a reduction step in its preparation.

[0136] Before their use in a process step, catalysts are generally subjected to sulfidation to form the active species. Depending on the sulfur content of the initial feedstock, a stream containing a sulfiding agent can be injected upstream of the optional pretreatment step or the hydrotreating step, preferably upstream of the hydrotreating step to ensure a sufficient quantity of sulfur to form the catalyst's active species (in sulfide form). This activation or sulfidation step is carried out using methods well known to those skilled in the art, and advantageously under a sulfur-reducing atmosphere in the presence of hydrogen and hydrogen sulfide.The sulfurizing agents are preferably hydrogen sulfide (H₂S), elemental sulfur, CS₂, mercaptans, sulfides and / or polysulfides, hydrocarbon fractions with a boiling point below 400°C containing sulfur compounds, or any other sulfur-containing compound used for activating hydrocarbon feedstocks to sulfide the catalyst. These sulfur-containing compounds are advantageously selected from alkyl disulfides, such as dimethyl disulfide (DMDS), alkyl sulfides, such as dimethyl sulfide, thiols, such as n-butylmercaptan (or 1-butanethiol), and polysulfide compounds of the tertiononyl polysulfide type. The catalyst can also be sulfided by the sulfur contained in the feedstock to be desulfurized. Preferably, the catalyst is sulfided in situ in the presence of a sulfurizing agent and a hydrocarbon feedstock.In one variant, the catalyst is sulfided in situ in the presence of the dimethyl disulfide feedstock. The sulfiding agent can be injected continuously. In another, preferred variant, the catalyst is sulfided in situ in the presence of H2S, preferably recycled from the gaseous effluent obtained in the separation stage after the hydrotreating stage.

[0137] The partially hydrotreated 120°C+ cut obtained at the end of the hydrotreatment step is sent, preferably directly, to a separation step.

[0138] Separation step (optional)

[0139] According to one variant, the partially hydrotreated cut with a boiling point above 120°C is subjected to a separation step before step b) of catalytic fluidized bed cracking, advantageously implemented in at least one separation section, to obtain at least one gaseous effluent and a cut with a boiling point above 120°C partially freed of its impurities.

[0140] This separation step makes it possible in particular to eliminate halogens (chlorine) in the form of hydrogen halides (HCl in particular) formed by the reaction of hydrogen ions and halide ions released by the hydrogenation of halogenated compounds during the hydrotreating step.

[0141] The separation step is advantageously carried out at a temperature between 20 and 250°C, preferably between 50 and 180°C, preferably between 80 and 150°C.

[0142] Advantageously, the separation step is carried out at a pressure close to that used in the hydrotreating step, preferably between 1.0 and 5.0 MPa, to facilitate hydrogen recycling if necessary. When several successive separation steps are performed, the pressure can be reduced to atmospheric pressure in the last separation step(s).

[0143] The separation step can advantageously be implemented by any method known to those skilled in the art, such as, for example, the combination of one or more separator(s) (balloon(s)), and / or one or more stripping column(s), this or these separator(s) (balloon(s)) and / or columns optionally being supplied by a stripping gas, for example a hydrogen-rich gas stream.

[0144] The separation section may also include means for washing the partially hydrotreated 120°C+ section by contact with an aqueous solution. The separation section may be at least partially carried out in shared or separate washing and separation equipment.

[0145] Advantageously, the separation step includes an injection of an aqueous solution, preferably an injection of water, into the partially hydrotreated 120°C+ cut from the hydrotreatment step, upstream of the separation section, so as to dissolve at least part and preferably all of the hydrogen halides (especially HCl) and any salts present.

[0146] The aqueous solution can be water. It can also be a basic aqueous solution (by adding NaOH, Na3CO3, NaHCO3, Ca(OH)2, CaSCl, or CaCO3, for example). Using a basic solution neutralizes hydrogen halides and any dissolved salts.

[0147] In a possible embodiment of the invention, the separation step comprises injecting an aqueous solution into the partially hydrotreated 120°C+ cut obtained from the hydrotreatment step, followed by the separation section advantageously comprising a separation phase enabling the production of at least one aqueous effluent containing hydrogen halides (in particular HCl) and any dissolved salts, the washed partially hydrotreated 120°C+ cut, and a partially washed gaseous effluent. The aqueous effluent and the washed partially hydrotreated 120°C+ cut can then be separated in a settling tank to obtain the washed partially hydrotreated 120°C+ cut and the aqueous effluent.The partially washed gaseous effluent can simultaneously be introduced into a scrubbing column where it flows counter-currently to an aqueous stream, preferably of the same nature as the aqueous solution injected into the partially hydrotreated 120°C+ section. This allows for the removal, at least in part, and preferably entirely, of the hydrochloric acid contained in the partially washed gaseous effluent, thus obtaining the gaseous effluent, preferably consisting primarily of hydrogen, and an acidic aqueous stream. The aqueous effluent from the settling tank can optionally be mixed with the acidic aqueous stream and used, possibly mixed with the acidic aqueous stream, in a water recycling circuit to supply the separation stage with the aqueous solution upstream of the separation section and / or with the aqueous stream in the scrubbing column.The said water recycling circuit may include a water top-up and / or a basic solution and / or a purge to remove impurities.

[0148] The hydrotreating stage mainly implements hydrogenation reactions of halogenated compounds, and to a lesser extent also other hydrotreating reactions such as hydrodeazotation which generates NH3 by hydrogenation of nitrogen compounds and hydrodesulfurization which generates H2S by hydrogenation of sulfur compounds.

[0149] When NH3 is present in the 120°C+ partially hydrotreated cut, the separation step also allows the removal of ammonium chloride salts, which are formed by reaction between chloride ions, released by the hydrogenation of chlorinated compounds in the form of HCl, particularly during the hydrotreatment step, and ammonium ions, generated by the hydrogenation of nitrogen compounds in the form of NH3 during the hydrotreatment step by dissolving them in the aqueous solution.

[0150] When H2S is present in the partially hydrotreated 120°C+ cut, the separation step also allows the removal of ammonium sulfide salts ((NH^S) which are formed by reaction between H2S from the hydrodesulfurization of sulfide compounds and NH3 by dissolving them in the aqueous solution.

[0151] According to one embodiment, and depending on the content of chlorinated compounds in the 120°C+ section, a stream containing a nitrogenous compound such as ammonia or an amine, for example monoethanolamine, diethanolamine and / or monodiethanolamine, can be injected upstream of the hydrotreating step to ensure a sufficient quantity of ammonium ions to combine the chloride ions formed during the hydrotreating step in the form of ammonium chloride salts, thus limiting the formation of hydrochloric acid and thus limiting corrosion downstream of the separation section.

[0152] The gaseous effluent obtained from the separation step advantageously contains hydrogen, preferably at least 80% by volume, and preferably at least 85% by volume, of hydrogen. The gaseous effluent obtained from the separation step contains very little chlorine, generally less than 5 ppm by weight of chlorine, which allows it to be sent to a refining unit requiring hydrogen.

[0153] According to one embodiment, said gaseous effluent can at least partly be recycled to the hydrotreatment stage, the recycling system being able to include a purification section (for example, for the adsorption of heavy metals such as mercury).

[0154] Regarding the 120°C+ fraction from the separation stage, and according to one variant, a portion of this fraction can be recycled upstream of the hydrotreating stage. Recycling a portion of the 120°C+ fraction from the separation stage to or upstream of the hydrotreating stage advantageously allows for the dilution of impurities and the control of the temperature in the hydrotreating stage, where reactions can be highly exothermic. Advantageously, the quantity of the 120°C+ cut from the recycled separation step is adjusted so that the weight ratio between the recycled stream from the separation step and the 120°C+ cut feeding the hydrotreating step is between 0.01 and 10, preferably between 0.1 and 7, and particularly preferably between 0.2 and 5.Injection can be performed at the first catalytic bed of the reaction section of the hydrotreating step or between the different catalytic beds. When the hydrotreating reaction section of the hydrotreating step comprises two reactors operating in switchable mode, at least a portion of the 120°C+ cut from the separation step can be recycled between the two reactors.

[0155] According to another preferred embodiment, the 120°C+ cut partially freed of its impurities from the separation step is sent in part and preferably in whole, directly into step b) of FCC.

[0156] The said 120°C+ cut from the separation step thus obtained has a composition compatible for being introduced alone or as a co-charge of a fossil feed and / or a feed from biomass conversion in an FCC unit.

[0157] The 120°C+ partially hydrotreated cut from the separation step is notably a cut with reduced content of halogenated compounds, and in particular chlorine.

[0158] Preferably, at least 50%, and more preferably at least 75% of the halogenated compounds (especially chlorine) of the 120°C+ cut obtained after pre-fractionation are removed during the hydrotreating step.

[0159] Preferably, at least 30%, and more preferably at least 50% of the metallic elements (especially silicon) of the 120°C+ cut obtained after pre-fractionation are removed during the hydrotreating step.

[0160] Generally, a maximum of 60%, and more preferably a maximum of 50%, of the diolefins in the 120°C+ cut obtained after pre-fractionation are eliminated during the hydrotreatment step.

[0161] Preferably, at least 80%, and more preferably at least 90%, of the monoolefins are retained during the hydrotreating step.

[0162] The contents are given as relative weight concentrations, percentage (%) by weight, part(s) per million (ppm) by weight or part(s) per billion (ppb) by weight, relative to the total weight of the stream considered.

[0163] Step b) of FCC

[0164] According to the invention, the process comprises a fluidized bed catalytic cracking step implemented in a fluidized bed catalytic cracking reaction section within a substantially vertical reactor, either in upward or downward mode, in the presence of a zeolite catalyst at a reactor temperature between 450°C and 600°C, fed by at least one of said fractions having a boiling point above 120°C to produce propylene. The fluidized bed catalytic cracking (FCC) process is widely used in the refining industry for the conversion of atmospheric diesel, vacuum diesel and atmospheric residues, lignocellulosic feedstock, or more generally, feedstock derived from biomass conversion, alone or in mixtures, into high-octane gasoline, light fuel oil, heavy fuel oil, light olefin-rich gas (propylene, butylene), and coke.

[0165] Recent developments in the field of FCC (Fused Combustion Process) often point towards increased propylene production in response to growing global demand for propylene. This increase in propylene yield can be achieved through the selection of suitable catalysts and operating conditions, as well as by choosing a feedstock specifically designed for propylene production, such as a cut containing C9+ olefins, and in particular C9 olefins.

[0166] The FCC unit uses a high-activity zeolite catalyst to crack heavy hydrocarbon molecules. A conventional FCC unit is used. A summary description of catalytic cracking (the first industrial implementation of which dates back to 1936 (HOUDRY process) or 1942 for the use of a fluidized bed catalyst) can be found, for example, in ULLMANS ENCYCLOPEDIA OF INDUSTRIAL CHEMISTRY VOLUME A 18, 1991, pages 61 to 64. The choice of catalyst and operating conditions depends on the desired products and the feedstock being processed, as described, for example, in the article by M. MARCILLY, pages 990-991, published in the journal of the French Petroleum Institute, Nov.-Dec. 1975, pages 969-1006.

[0167] The fluidized bed catalytic cracking step is generally carried out in a fluidized bed catalytic cracking reaction section within a substantially vertical reactor, either in a riser or downer configuration, in the presence of a zeolite catalyst at a reactor temperature between 450°C and 600°C. The contact time in the reactor is generally less than 1 minute, often ranging from 0.1 to 50 seconds.

[0168] A conventional zeolite catalyst, comprising a matrix, possibly an additive, and at least one zeolite, is typically used in the FCC process. The amount of zeolite varies but is usually 3 to 60% by weight, often 6 to 50% by weight, and most commonly 10 to 45% by weight relative to the catalyst weight. The zeolite is usually dispersed within the matrix. The amount of additive is usually 0 to 30% by weight and often 0 to 20% by weight relative to the catalyst weight. The matrix quantity makes up the difference to 100% by weight. The additive is generally selected from the group formed by the oxides of HA metals in the periodic table, such as magnesium oxide or calcium oxide, rare earth oxides, and HA metal titanates.The matrix is ​​most often silica, alumina, silica-alumina, silica-magnesia, clay, or a mixture of two or more of these products. The most commonly used zeolite is zeolite Y.

[0169] According to one embodiment, the feed introduced into the FCC step can be the 120°C+ cut alone. In this case, and in order to be compatible with an FCC unit, it preferably has a halogen content less than or equal to 10 ppm by weight, preferably less than 5 ppm by weight.

[0170] In another embodiment, the feed introduced into the FCC stage can be a mixture of the 120°C+ cut with a fossil feed and / or a feed from biomass conversion. In this case, the 120°C+ cut may have a content too high for an FCC unit. Indeed, when the halogenated compound content is greater than 10 ppm, or even 5 ppm by weight in the 120°C+ cut, a chlorine content below 10 ppm, or even 5 ppm, can be achieved by diluting the unit inlet with the fossil feed and / or the feed from biomass conversion.

[0171] Preferably, given the conventional capabilities of a CFC unit, the 120°C+ cut is introduced as a co-feed with a fossil feed and / or a feed from biomass conversion.

[0172] Generally, the mass ratio between the 120°C+ cut flow rate and the flow rate of fossil feed and / or feed from biomass conversion introduced into the FCC unit in the process according to the invention is generally less than 1, and preferably between 0.01 and 0.9, and preferably between 0.02 and 0.5, and preferably between 0.03 and 0.1.

[0173] The fossil feed used in the fluidized bed catalytic cracking unit can be selected from gasoline, gas oils, vacuum gas oils, atmospheric residues, vacuum residues, atmospheric distillates, vacuum distillates, heavy fuel oils, oils, waxes and paraffins, used oils, residues or deasphalted crudes, deasphalted oils, petroleum feeds from thermal or catalytic conversion processes, or mixtures of such feeds.

[0174] The biomass feedstock used in the fluidized bed catalytic cracking unit can be selected from vegetable oils, algae or algal oils, fish oils, used cooking oils, and fats of vegetable or animal origin; methyl esters of fatty acids of vegetable and / or animal origin, methyl esters of fatty acids from used cooking vegetable oils, feedstocks from thermal or catalytic biomass conversion processes, or mixtures of such feedstocks. It may, in particular, be a feedstock such as that described in the pyrolysis oil feedstock section above.

[0175] The FCC step allows the production of olefins, notably propylene (C3), which can subsequently be (re)polymerized. The process according to the invention thus contributes to the circular economy of plastics.

[0176] The 120°C cup

[0177] One or more further processing steps of the 120°C- cut from step a) of pre-fractionation, possibly pre-treated, can be carried out in order to valorize it in petrochemicals (steam cracking or catalytic reforming), or in the production of fuels.

[0178] The 120°C cut, containing the majority of halogenated compounds, silicon, diolefins, and C8 monoolefins, often has high levels of impurities incompatible with direct storage in a fuel storage facility or with steam cracking units or units located downstream of steam cracking units. Steam cracking units require very high feedstock purities, particularly low levels of chlorine, diolefins, olefins, metals, and sulfur. The specification for the chlorine content at the inlet of a steam cracking unit is typically a maximum of 3 ppm by weight, preferably a maximum of 1 ppm by weight.

[0179] Thus, the 120°C fraction is generally subjected to hydrogen treatment, also called hydrorefining, which removes most impurities before it is used in petrochemicals (steam cracking or catalytic reforming) or for fuel production. Hydrorefining here refers to selective hydrogenation and / or hydrogenation and / or hydrotreatment. Hydrorefining can be carried out in several ways.

[0180] According to a first embodiment, the 120°C- cut is subjected to a selective hydrogenation step, then to a hydrogenation step, then possibly to a hydrotreatment step, then to a separation step.

[0181] According to a second embodiment, the 120°C- fraction is subjected to a hydrogenation step in a mixture with a portion of the 120°C- fraction from the downstream separation step (recycle), then optionally to a hydrotreating step, and finally to a separation step. According to a third embodiment, the 120°C- fraction is subjected to a mild hydrotreating step, followed by a separation step.

[0182] Further processing steps can be carried out on the 120°C cut alone or mixed with a fossil feed and / or a feed from biomass conversion.

[0183] Hydrorefining with selective hydrogenation

[0184] According to this first embodiment, the 120°C- fraction is subjected to a selective hydrogenation step to remove at least some, and preferably all, of the diolefins, followed by a further hydrogenation step to remove at least some, and preferably all, of the silicon, chlorine, and monoolefins. Depending on the impurity content of the hydrogenated 120°C- fraction, it may then be subjected to a hydrotreating step to remove at least some, and preferably all, of the sulfur and nitrogen. The hydrogenated and possibly hydrotreated 120°C- fraction then undergoes a separation step, possibly in the presence of an aqueous solution. The 120°C- fraction thus treated meets the specifications of a steam cracker feedstock.

[0185] This embodiment allows, in particular, for the control of the strong reaction exotherms generated by the concentration of monoolefins / diolefins within the 120°C section through a selective hydrogenation step. Indeed, it is the high concentration of olefins, and especially diolefins, in this section that necessitates temperature control of the reaction medium, as the hydrogenation reactions, particularly of a portion of the monoolefins and diolefins, are highly exothermic.

[0186] The selective hydrogenation step is carried out under hydrogen pressure and temperature conditions that maintain the 120°C fraction in the liquid phase with just enough soluble hydrogen to selectively hydrogenate the diolefins present in the fraction. Selective hydrogenation of diolefins in the liquid phase thus prevents, or at least limits, the formation of "gums," i.e., the polymerization of diolefins and therefore the formation of oligomers and polymers, which can clog the downstream reaction section. This selective hydrogenation step yields a 120°C fraction that is selectively hydrogenated, i.e., a fraction with a reduced olefin content, particularly diolefins, and preferably free of diolefins.

[0187] The selective hydrogenation step is carried out in a reaction section, preferably a fixed-bed section, fed by said 120°C- cut, and a gas stream comprising hydrogen, in the presence of at least one selective hydrogenation catalyst, at an average temperature between 100 and 260°C, preferably between 110 and 250°C, preferably between 120 and 220°C, a partial pressure of hydrogen between 1.0 and 10.0 MPa abs., preferably between 1.5 and 8.0 MPa abs., and most preferably between 2.0 and 6.0 MPa abs., and an hourly volumetric rate between 0.1 and 10.0 h -1 , preferably between 0.2 and 5.0 h' 1 , and most preferably between 0.3 and 3.0 h _ 1, to obtain a 120°C-selectively hydrogenated cut. The quantity of the gas stream containing hydrogen (H2), feeding said reaction section, is advantageously such that the hydrogen coverage is between 1 and 200 Nm 3 of hydrogen per m3 load (Nm 3 / m 3 ), preferably between 1 and 150 Nm 3 of hydrogen per m 3 load (Nm 3 / m 3 ), preferably between 5 and 100 Nm 3 of hydrogen per m 3 load (Nm 3 / m 3 ). The definitions of mean temperature (WABT), WH and hydrogen cover correspond to those described above.

[0188] The other conditions of the selective hydrogenation step (nature of the gas flow, reaction section (number of reactors, number of catalytic beds, internal, PRS, ...), presence of a diluent, presence of a guard bed, nature of the catalyst) are those described in the hydrotreatment section of the 120°C+ cut above.

[0189] The impurity content, particularly diolefins, of the selectively hydrogenated 120°C fraction obtained after the selective hydrogenation step is reduced compared to that of the same impurities, particularly diolefins, in the 120°C fraction obtained after pre-fractionation. The selective hydrogenation step converts at least 60% and preferably at least 70% of the diolefins contained in the 120°C fraction.

[0190] The 120°C- selectively hydrogenated cut, obtained at the end of the selective hydrogenation step, is sent at least in part and preferably in whole, preferably directly, to a hydrogenation step.

[0191] The hydrogenation step is carried out under hydrogen pressure and temperature conditions that allow for the hydrodemetallation of at least some of the metals, notably the retention of silicon, and hydrodechlorination by removing at least some, and preferably all, of the chlorine. It also allows for the hydrogenation of monoolefins. This step helps to limit the catalytic deactivation of the reaction section of the downstream hydrotreating step, when present.

[0192] The hydrogenation step is carried out in a hydrogenation reaction section, employing at least one fixed-bed reactor having n catalytic beds, n being an integer greater than or equal to 1, each comprising at least one hydrogenation catalyst, said hydrogenation reaction section being fed at least by said 120°C- selectively hydrogenated cut from the selective hydrogenation step and a gas stream comprising hydrogen, said hydrogenation reaction section being carried out at an average temperature between 180 and 380°C, preferably between 200 and 350°C, and particularly preferably between 240 and 330°C, a partial pressure of hydrogen between 0.5 and 10.0 MPa abs., preferably between 0.5 and 8.0 MPa abs. and preferably between 0.5 and 6.0 MPa abs., and an hourly volumetric velocity between 0.1 and 10.0 h' 1 , preferably between 0.2 and 5.0 h -1and preferably between 0.3 and 3.0 h'1, to obtain a 120°C-hydrogenated cut. The quantity of the gas stream containing hydrogen (H2) feeding said reaction section is advantageously such that the hydrogen coverage is between 100 and 1500 Nm 3 of hydrogen per m 3 load (Nm 3 / m 3 ), preferably between 120 and 1000 Nm 3 of hydrogen per m 3 load (Nm 3 / m 3 ), preferably between 150 and 800 Nm 3 of hydrogen per m 3 load (Nm 3 / m 3 ). The definitions of mean temperature (WABT), WH and hydrogen cover correspond to those described above.

[0193] The other conditions of the hydrogenation step (nature of the gas flow, reaction section (number of reactors, number of catalytic beds, internal, PRS, ...), presence of a diluent, presence of a guard bed, nature of the catalyst) are those described in the hydrotreatment section of the 120°C+ cut above.

[0194] According to a particular embodiment, all or part of the charge (120°C- cut) can be injected in a staged manner at the inlet of each catalytic bed in order to manage the exotherms as described in FR2969642. In this case, the total flux of the charge (120°C- cut) is divided into a number of different partial fluxes equal to the number of catalytic beds in the reactor, the different partial fluxes are injected at the inlet of successive catalytic beds in increasing proportions.

[0195] The hydrogenation step yields a hydrogenated 120°C fraction, meaning a fraction with reduced metal content, particularly silicon, and halogen content, particularly chlorine. It also hydrogenates monoolefins. The hydrogenation step typically converts at least 40%, and preferably at least 60%, of the monoolefins in the 120°C fraction. Preferably, at least 50%, and more preferably at least 75%, of the chlorine and silicon in the 120°C fraction are removed during the hydrogenation step. Generally, the silicon content is less than 10 ppm wt. Depending on the residual impurity content in the 120°C- hydrogenated cut obtained after the hydrogenation step) and its final destination, this cut may be subjected to a hydrotreatment step.When this fraction is to be used as feed for a steam cracker to produce olefins, a hydrotreating step is generally necessary to meet the sulfur and nitrogen specifications. In this case, the 120°C hydrogenated fraction obtained from the hydrogenation step is sent, at least partially and preferably entirely, directly to a hydrotreating step.

[0196] When it is desired to send this fraction to a fuel storage unit, a hydrotreating step may not be necessary. In this case, the 120°C hydrogenated fraction obtained at the end of the hydrogenation step is sent at least partially, and preferably entirely, directly to a separation step.

[0197] Advantageously, the hydrotreating step implements hydrotreating reactions well known to those skilled in the art, and more particularly hydrotreating reactions such as aromatic hydrogenation, hydrodesulfurization and hydrodeazotation.

[0198] The hydrotreating step is implemented in a hydrotreating reaction section, employing 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 hydrotreating reaction section being fed at least by the 120°C- hydrogenated cut from the hydrogenation step and a gas stream comprising hydrogen, said hydrotreating reaction section being implemented at an average temperature between 200 and 400°C, preferably between 250 and 360°C, a partial pressure of hydrogen between 0.5 and 10.0 MPa abs., preferably between 0.5 and 8.0 MPa abs. and most preferably between 0.5 and 6.0 MPa abs., and an hourly volumetric rate 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 h' 1to obtain a 120°C hydrotreated cut. The hydrogen blanket is advantageously between 100 and 1500 Nm 3 of hydrogen per m 3 of the charge that feeds the hydrotreatment stage, and preferably between 120 and 1000 Nm 3 / m 3 , preferably between 150 and 800 Nm 3 / m 3 The definitions of mean temperature (WABT), WH and hydrogen cover correspond to those described above.

[0199] The other conditions of the hydrotreating step (nature of the gas flow, reaction section (number of reactors, number of catalytic beds, internal, PRS, ...), presence of a diluent, presence of a guard bed, nature of the catalyst) are those described in the hydrotreating section of the 120°C+ section above.

[0200] The 120°C hydrotreated cut from the hydrotreatment step is then sent, in part or in whole, to a separation step.

[0201] The separation step, advantageously implemented in at least one separation section, is fed at least by the 120°C- partially hydrogenated cut from the hydrogenation step or by the 120°C- partially hydrotreated cut from the hydrotreatment step to obtain at least a gaseous effluent and a 120°C- cut free of its impurities.

[0202] This separation step is carried out in the same manner as the 120°C+ cut separation step described above. The separation step is advantageously performed at a temperature between 20 and 400°C, preferably between 50 and 300°C, and most preferably between 80 and 280°C. Advantageously, the separation step is carried out at a pressure close to that used in the hydrotreating step, preferably between 0.5 and 10.0 MPa, to facilitate hydrogen recycling if required. When several successive separation steps are performed, the pressure can be reduced to atmospheric pressure in the last separation step(s).

[0203] Advantageously, the washing / separation step includes an injection of an aqueous solution, preferably an injection of water, into the 120°C- hydrogenated or hydrotreated section, upstream of the separation section, so as to dissolve at least part and preferably all of the hydrogen halides (especially HCl) and any salts present.

[0204] This separation step makes it possible in particular to eliminate ammonium chloride salts, which are formed by reaction between chloride ions, released by the hydrogenation of chlorinated compounds in the form of HCl, particularly during the hydrogenation step and subsequent dissolution in water, and ammonium ions, generated in particular by the hydrogenation of nitrogen compounds in the form of NH3 during the hydrogenation and / or hydrotreating step and / or supplied by the injection of an amine and subsequent dissolution in water, and thus to limit the risks of clogging, particularly 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. This step also allows the elimination of hydrochloric acid formed by the reaction of hydrogen ions and halide ions released by the hydrogenation of halogenated compounds during the hydrogenation step which dissolve in the aqueous solution.When H2S is formed, the separation step also allows the removal of ammonium sulfide salts ((NH^S) which are formed by reaction between H2S from the hydrodesulfurization of sulfide compounds and NH3 by dissolving them in the aqueous solution.

[0205] After the separation of the gaseous effluent, said 120°C- cut, freed from its impurities and preferably washed, is preferably sent to a steam stripping stage operating preferably at a pressure between 0.5 and 2 MPa abs, to carry out a separation of the hydrogen sulfide (H2S) dissolved in said 120°C- cut freed from its impurities.

[0206] Preferably, said 120°C- cut obtained after the separation step has a nitrogen content of less than 10 ppm by weight, preferably less than 5 ppm by weight.

[0207] Preferably, said 120°C- cut obtained after the separation step has a sulfur content of less than 10 ppm by weight.

[0208] Preferably, said 120°C- cut obtained after the separation step has an oxygen content of less than 10 ppm by weight.

[0209] Preferably, said 120°C- cut obtained after the separation step has a metal content of less than 10 ppm by weight, preferably less than 2 ppm by weight, and the silicon content is less than 5 ppm by weight.

[0210] Preferably, said 120°C- cut obtained after the separation step has a halogen content (in particular chlorine) of less than 3 ppm by weight.

[0211] The contents are given as relative weight concentrations, percentage (%) by weight, part(s) per million (ppm) by weight or part(s) per billion (ppb) by weight, relative to the total weight of the stream considered.

[0212] Part of said 120°C- cut from the separation step can be recycled within the selective hydrogenation step and / or the hydrogenation step, and possibly within the hydrotreating step in order to constitute a liquid recycle or a quench allowing the control of exotherms.

[0213] According to another embodiment, said 120°C cut, freed from its impurities, can also be sent in part or in whole to a fuel storage unit, for example a naphtha storage unit, from conventional petroleum feedstocks.

[0214] According to another preferred embodiment, the 120°C cut, freed from its impurities, is partially, and preferably entirely, sent directly to the inlet of a steam cracking unit. According to another embodiment, the 120°C cut, freed from its impurities, is partially, and preferably entirely, sent directly to the inlet of a catalytic reforming unit for the production of aromatic compounds.

[0215] Hydrorefining with recycling

[0216] In another embodiment, the strong reaction exotherms generated by the concentration of monoolefins / diolefins within the 120°C- section are controlled by recycling a portion of the treated 120°C- section. It is known that recycling a portion of the product obtained to or upstream of at least one of the reaction steps advantageously allows, on the one hand, for the dilution of impurities and, on the other hand, for temperature control in the reaction step(s) where reactions may be strongly exothermic.

[0217] According to this second embodiment, the 120°C- fraction is subjected, in a mixture with at least a portion of the 120°C- fraction from the separation (recycle) step and a gas stream containing hydrogen, to a hydrogenation step that removes, in particular, at least partially and preferably completely, silicon and chlorine, diolefins, and C8- monoolefins. Depending on the impurity content of the hydrogenated 120°C- fraction, it may then be subjected to a hydrotreating step to remove, in particular, at least partially and preferably completely, sulfur and nitrogen. The hydrogenated and optionally hydrotreated 120°C- fraction then undergoes a separation step, possibly in the presence of an aqueous solution. The 120°C- fraction thus treated meets the specifications of a steam cracker feedstock.

[0218] Unlike the first embodiment involving a selective hydrogenation step to eliminate diolefins, this second embodiment involves recycling in the hydrogenation step in which the diolefins are hydrogenated, which allows control of the exothermic reaction.

[0219] The hydrogenation step according to this embodiment is carried out in the same way as that according to the first embodiment, except that it can be carried out at a lower temperature. In particular, the hydrogenation step according to this embodiment is carried out under hydrogen pressure and temperature conditions that allow the hydrogenation of diolefins and monoolefins to occur at the beginning of the hydrogenation reaction section, while a rising temperature profile allows hydrometallation and hydrodechlorination to occur, particularly at the end of the hydrogenation reaction section.Thus, the hydrogenation step is carried out in a hydrogenation reaction section, employing at least one fixed-bed reactor having n catalytic beds, n being an integer greater than or equal to 1, each comprising at least one hydrogenation catalyst, said hydrogenation reaction section being fed at least by said 120°C- cut from the pre-fractionation step, optionally pretreated, mixed with at least a portion of the 120°C- cut from the downstream separation step and a gas stream comprising hydrogen, said hydrogenation reaction section being carried out at an average temperature between 120 and 380°C, preferably between 180 and 350°C, and particularly preferably between 200 and 330°C, a partial pressure of hydrogen between 0.5 and 10.0 MPa abs., preferably between 0.5 and 8.0 MPa abs.and very preferably between 0.5 and 6.0 MPa abs, and an hourly volumetric velocity between 0.1 and 10.0 h'. 1 , preferably between 0.2 and 5.0 h' 1 , and most preferably between 0.3 and 3.0 h' 1 to obtain a 120°C hydrogenated cut. The quantity of the gas stream containing hydrogen (H2) feeding said reaction section is advantageously such that the hydrogen coverage is between 100 and 1500 Nm 3 of hydrogen per m 3 load (Nm 3 / m 3 ), preferably between 120 and 1000 Nm 3 of hydrogen per m 3 load (Nm 3 / m 3 ), preferably between 150 and 800 Nm 3 of hydrogen per m 3 load (Nm 3 / m 3 ). The definitions of mean temperature (WABT), WH and hydrogen cover correspond to those described above.

[0220] The other conditions of the hydrogenation step (nature of the gas flow, reaction section (number of reactors, number of catalytic beds, internal, PRS, ...), presence of a diluent, presence of a guard bed, nature of the catalyst) are those described in the hydrotreatment section of the 120°C+ cut above.

[0221] To manage exothermicity in the reaction section, a portion of the 120°C- fraction from the separation step must be recycled to the hydrogenation step. Advantageously, the amount of recycled 120°C- fraction from the separation step is adjusted so that the weight ratio between the 120°C- fraction from the separation step recycled to the hydrogenation step and the 120°C- fraction from the pre-fractionation step introduced into the hydrogenation step is between 0.01 and 10, preferably between 0.1 and 7, and particularly preferably between 0.2 and 5. This recycle ratio allows control of the temperature rise in the hydrogenation step. In addition, a liquid and / or gaseous diluent can be injected into the hydrogenation step (also called quench according to Anglo-Saxon terminology) in addition to the 120°C cut from the separation step in the same way as described above.

[0222] The 120°C cut, thus hydrogenated, can then be subjected to a hydrotreatment step as described for the first embodiment, allowing the removal of sulfur and nitrogen in particular.

[0223] The hydrogenated and optionally hydrotreated 120°C fraction then undergoes a separation step, possibly in the presence of an aqueous solution, as described for the first embodiment. The 120°C fraction resulting from the separation step contains impurities (N, S, O, metals, halogens) similar to those of the 120°C fraction obtained with selective hydrogenation described above. It meets the specifications of a steam cracker feedstock.

[0224] According to another embodiment, said 120°C cut, freed from its impurities, can also be sent in part or in whole to a fuel storage unit, for example a naphtha storage unit, from conventional petroleum feedstocks.

[0225] According to another preferred embodiment, said 120°C cut, freed from its impurities, is partly and preferably totally sent directly to the inlet of a steam cracking unit.

[0226] According to another embodiment, said 120°C- cut, freed from its impurities, is partly and preferably totally sent directly to the inlet of a catalytic reforming unit for the production of aromatic compounds.

[0227] Gentle hydrotreatment

[0228] Depending on the impurity levels, the 120°C cut can also undergo a mild hydrotreatment step followed by a separation step before being sent to a fuel storage unit or to a steam cracking unit.

[0229] The objective of this "mild" hydrotreating of the 120°C- cut is identical to that of the "mild" hydrotreating of the 120°C+ cut: the removal of halogenated compounds to make the 120°C- cut compatible, either alone or as a co-feed with fossil fuel and / or biomass conversion feed in a steam cracker. This "mild" hydrotreating does not aim for complete hydrotreating. Other impurities contained in the 120°C- cut (metals, silicon, nitrogen, etc.) are not necessarily completely removed during the mild hydrotreating step, although the operating conditions allow for the removal of at least some of them. The residual impurity levels in the cut can be made compatible with the specifications for a steam cracker, particularly through possible dilution of the cut with fossil fuel and / or biomass conversion feed.

[0230] The gentle hydrotreating step of the 120°C- cut is carried out in the same way (same operating conditions, same catalysts, ...) as the gentle hydrotreating step of the 120°C+ cut described above.

[0231] The 120°C- partially hydrotreated cut is then subjected to a separation step carried out in the same way as the separation step described for the 120°C+ cut.

[0232] Steam cracking

[0233] According to a first embodiment, the 120°C- fraction, possibly cleaned by hydrogen treatment as described in the three modes above, can be sent in whole or in part to a steam cracking stage, possibly mixed with a fossil feedstock and / or a feedstock from biomass conversion suitable for the steam cracker. Indeed, the 120°C- fraction is particularly well-suited for processing in a steam cracker to produce light olefins sought after for the petrochemical industry, notably ethylene and propylene.

[0234] The steam cracking step is advantageously carried out in at least one pyrolysis furnace at a temperature between 700 and 900°C, preferably between 750 and 850°C, and at a pressure 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 the steam cracking step and after 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 entering the steam cracking step. Preferably, the steam cracking step is carried out in several pyrolysis furnaces in parallel in order to adapt the operating conditions to the different flow rates, and also to manage the decoking times of the tubes. A furnace comprises one or more tubes arranged in parallel.A furnace can also refer to a group of furnaces operating in parallel. For example, one furnace might be dedicated to cracking the naphtha cut and another to the middle distillates cut.

[0235] The effluents from the various steam cracking furnaces are generally recombined before separation to form a final effluent. It is understood that the steam cracking stage includes not only the steam cracking furnaces themselves but also the substages associated with steam cracking that are well known to those skilled in the art. These substages may include, in particular, heat exchangers, columns and catalytic reactors, and recirculation to the furnaces. A column typically allows the effluent to be fractionated in order to recover at least a light fraction containing hydrogen and compounds with 2 to 5 carbon atoms, a fraction containing pyrolysis gasoline, and possibly a heavier fraction. Columns are used to separate the different components of the light fraction to recover at least an ethylene-rich cut (C2 cut), a propylene-rich cut (C3 cut), and possibly a butene-rich cut (C4 cut).Catalytic reactors are particularly useful for hydrogenating C2, C3, and even C4 fractions, as well as pyrolysis gasoline. Saturated compounds, especially those with 2 to 4 carbon atoms, are advantageously recycled to steam cracking furnaces to increase overall olefin yields.

[0236] This steam cracking step yields at least one effluent containing olefins comprising 2, 3, and / or 4 carbon atoms (i.e., C2, C3, and / or C4 olefins) at satisfactory levels, particularly greater than or equal to 30% by weight, especially greater than or equal to 40% by weight, and even greater than or equal to 50% by weight of total olefins comprising 2, 3, and 4 carbon atoms relative to the weight of the steam cracking effluent. These C2, C3, and C4 olefins can then be advantageously used as polyolefin monomers.

[0237] When the residual impurity levels contained in the 120°C- cut are not compatible with the specifications for a steam cracking unit, the cut can be used as a co-feed with a fossil feed and / or a feed from biomass conversion.

[0238] The petroleum feedstock used in the steam cracking unit is preferably chosen from naphtha, kerosene, diesel, or mixtures of such feedstocks.

[0239] The load resulting from biomass conversion is a load as described below in the "load" section.

[0240] In this case, the 120°C fraction is introduced into the steam cracking unit along with a fossil feedstock and / or a biomass feedstock in such a quantity that the chlorine content in the fossil feedstock / biomass mixture and the 120°C fraction is less than or equal to 3 ppm by weight, preferably less than or equal to 1 ppm by weight. Generally, the mass ratio between the flow rate of the 120°C fraction and the flow rate of the fossil feedstock / biomass introduced into the steam cracking unit is generally less than 1, and preferably between 0.01 and 0.9, and preferably between 0.02 and 0.5.

[0241] Catalytic reforming

[0242] According to a second embodiment, the 120°C- cut, possibly cleared by hydrogen treatment as described in the three modes described above, can be sent to an aromatic complex comprising at least one catalytic reforming step in order to produce aromatic compounds.

[0243] This embodiment is particularly advantageous for a 120°C blend derived from tire pyrolysis oil, which is generally highly aromatic. Such a blend exhibits a high octane rating (RON / MON) and a high naphthenes and paraffins content, and can therefore be sent to a catalytic reforming unit. The purpose of catalytic reforming is to transform the naphthenic constituents (low octane rating) into high-octane aromatic constituents, which serve as the basis for gasoline blends.

[0244] The reaction conditions for contacting the 120°C- cup with a reforming catalyst are generally a temperature between 400 and 700°C, a pressure between 0.1 and 4 MPa, and a mass flow rate of feed treated per unit mass of catalyst per hour between 0.1 and 10 h -1Reforming catalysts generally include pure alumina as a support, chlorine, platinum and at least one additional metal chosen from the group formed by the metals of groups VI IB, VIIIB, IIIA and IVA.

[0245] Hydrorefining for fuel production in co-processing with a fossil feedstock and / or a feedstock from biomass conversion

[0246] According to a third embodiment, the 120°C fraction from step a) of pre-fractionation can preferably be sent directly to hydrorefining for fuel production in co-processing with fossil feedstocks and / or feedstocks from biomass conversion. In this case, the 120°C fraction generally does not undergo prior hydrogen treatment. It may be pre-treated. Hydrorefining processes using hydrogen from fossil feedstocks and / or feedstocks from biomass conversion are known to those skilled in the art and include processes such as hydrotreating or hydrocracking, which are well known to those skilled in the art.

[0247] The incorporation rate of the 120°C- cut in the fossil feed and / or in the feed from biomass conversion is not critical. The 120°C- cut can represent between 1% and 90% by weight of the hydroprocessing feed, or even between 1% and 50% by weight or between 1% and 30% by weight.

[0248] The 120°C cut can be introduced as a co-feed in a hydrotreating process with a fossil feed and / or a feed from biomass conversion. Such feeds are gasoline, diesel, vacuum diesel, atmospheric residues, vacuum residues, atmospheric distillates, vacuum distillates, heavy fuel oils, oils, waxes and paraffins, used oils, residues or deasphalted crudes, deasphalted oils, feeds from thermal or catalytic conversion processes, lignocellulosic feeds or more generally feeds from biomass such as vegetable oils, algae or algal oils, fish oils, used edible oils, and fats of vegetable or animal origin, taken alone or in mixtures.

[0249] A hydrotreating process particularly suitable for introducing the 120°C cut is a hydrotreating process of a vacuum gas oil, diesel, kerosene or gasoline feed and / or a feed from biomass chosen from vegetable oils, algae or algal oils, fish oils, used cooking oils, and fats of vegetable or animal origin.

[0250] The operating conditions used in these processes implementing the hydrotreating reactions of the feedstocks described above, preferably in a fixed bed, are generally as follows: the average temperature is advantageously between 180 and 450°C, and preferably between 250 and 440°C; the pressure is advantageously between 0.5 and 30 MPa, and preferably between 1 and 18 MPa; the hourly volumetric velocity is advantageously between 0.1 and 20 h -1 and preferably between 0.2 and 5 hours -1and a hydrogen blanket between 50 and 5000 Nm 3 of hydrogen per m 3 load, preferably between 80 and 2000 Nm 3 The definitions of mean temperature (WABT), WH, and hydrogen cover correspond to those described above. Conventional hydrotreating catalysts generally comprise an oxide support such as alumina, silica, silica-alumina, or titanium or magnesium oxides used alone or in mixtures with alumina or silica-alumina, and an active phase based on group VI B and VIII metals in their oxide forms, as well as phosphorus.

[0251] The 120°C cut can be introduced as a co-feed in a hydrocracking process with a fossil feed and / or a feed from biomass conversion.

[0252] The fossil feed used in a hydrocracking process is generally a hydrocarbon feed of which at least 50% by weight of the compounds have an initial boiling point above 300°C and a final boiling point below 650°C.It can be chosen from HCOs (Heavy Cycle Oil, according to Anglo-Saxon terminology (heavy gas oils from a catalytic cracking unit)), vacuum distillates, and atmospheric distillates, for example, gas oils from the direct distillation of crude oil or from conversion units such as catalytic cracking, coking, or visbreaking; feedstocks from aromatic extraction units, lubricating oil bases, or from the solvent dewaxing of lubricating oil bases; distillates from desulfurization or hydroconversion processes in fixed or bubbling beds of atmospheric residues and / or vacuum residues and / or deasphalted oils; or the feedstock can be deasphalted oil, include vegetable oils, or come from the conversion of biomass-derived feedstocks. It can also be paraffins from the Fischer-Tropsch process.The hydrocarbon feedstock treated according to the hydrocracking process of the invention may also be a mixture of the aforementioned feedstocks. Preferably, the feedstock is a vacuum distillate.

[0253] A hydrocracking process particularly suitable for introducing the 120°C cut is a hydrocracking process of a diesel feed under vacuum.

[0254] Hydrocracking processes are generally carried out in a fixed bed at an average temperature between 250 and 480°C, advantageously between 320 and 450°C, preferably between 330 and 435°C, under a pressure between 2 and 25 MPa, preferably between 3 and 20 MPa. The hourly volumetric rate of the feed relative to the volume of each catalyst (Wh) is advantageously between 0.1 and 40 h⁻¹. -1 preferably between 0.2 and 12 a.m. -1 , preferably between 0.4 and 6 a.m. -1 and a hydrogen blanket between 50 and 5000 Nm3 of hydrogen per m 3 load, preferably between 100 and 2000 Nm 3 The definitions of mean temperature (WABT), WH and hydrogen cover correspond to those described above.

[0255] Vacuum hydrocracking processes for distillates cover pressure and conversion ranges from mild to high-pressure hydrocracking. Mild hydrocracking refers to hydrocracking that results in moderate conversions, generally less than 40%, and operates at low pressures, typically between 2 MPa and 6 MPa.

[0256] The hydrocracking process can be either a "one-stage" or a "two-stage" process. A "one-stage" hydrocracking process generally begins with advanced hydrotreatment, the purpose of which is to achieve high levels of natural hardness (HDN), dry hardness (HDS), and high aerobic hardness (HDA) of the feed before it is sent to the hydrocracking catalyst(s). A "two-stage" hydrocracking process includes a first stage which, like the "one-stage" process, aims to hydrotreat the feed and achieve a conversion rate, typically between 40% and 60%. The effluent from the first stage then undergoes separation, usually by distillation, most often called intermediate separation, which aims to separate the conversion products from the unconverted fraction.In the second stage of the two-stage hydrocracking process, only the fraction of the feed not converted in the first stage is processed.

[0257] Hydrocracking catalysts are bifunctional: they combine an acidic function with a hydro-dehydrogenating function. The acidic function is provided by porous supports such as halogenated aluminas (particularly chlorinated or fluorinated), combinations of boron and aluminum oxides, amorphous or crystalline mesoporous aluminosilicates, and zeolites dispersed in an oxide binder. The hydro-dehydrogenating function is provided by the presence of an active phase based on at least one metal from group VIB and possibly at least one metal from group VIII of the periodic table. The most common formulations are nickel-molybdenum (NiMo) and nickel-tungsten (NiW), and more rarely cobalt-molybdenum (CoMo).

[0258] Storage in a fuel storage unit

[0259] According to a fourth embodiment, the 120°C cut, optionally pretreated and / or purified of impurities by hydrorefining as described in the embodiments above, can be sent to a fuel storage unit, for example a naphtha storage unit, derived from conventional petroleum feedstocks. Analytical methods used

[0260] The analytical methods and / or standards used to determine the characteristics of the various flows, particularly the load to be treated and the effluents, are known to those skilled in the art. They are listed below for information purposes in Table 1. Other methods considered equivalent may also be used, including equivalent IP, EN, or ISO methods.

[0261] Table 1

[0262] (1) MAV method described in the article: C. Lôpez-Garcia et al., Near Infrared Monitoring of Low Conjugated Diolefins Content in Hydrotreated FCC Gasoline Streams, Oil & Gas Science and Technology - Rev. IFP, Vol. 62 (2007), No. 1, pp. 57-68

[0263] LIST OF FIGURES

[0264] Mentioning the elements referenced in Figures 1 and 2 allows for a better understanding of the invention, without the latter being limited to the particular embodiments illustrated in Figures 1 and 2. The different embodiments presented can be used alone or in combination with each other, without limitation of combination.

[0265] Figure 1 shows a diagram of a particular embodiment of the process of the present invention, comprising:

[0266] - a step a) of pre-fractionation of a feed comprising plastic pyrolysis oil and / or tires and / or solid recovered fuels 1 to obtain a cut 2 having a boiling point less than or equal to 120°C (120°C- cut) and a cut 3 having a boiling point greater than 120°C (120°C+ cut). The 120°C cut point allows the C9+ olefins to be retained in the 120°C+ cut while reducing impurities harmful to step b);

[0267] - a step b) of catalytic cracking in fluidized bed of the 120°C+ 3 cut, possibly in the presence of a fossil feedstock and / or a feedstock from the conversion of biomass 4 in order to produce FCC products 5 (in particular propylene).

[0268] Figure 2 represents a diagram of a particular embodiment of the process of the present invention which is based on the diagram of Figure 1. This diagram shows the integration of the optional steps into the process according to the invention.

[0269] After the pre-fractionation step a), the 120°C+ 3 cut is subjected to a pretreatment 6, for example filtration or adsorption, allowing to obtain a pre-treated 120°C+ cut 7 with fewer impurities.

[0270] When the residual content of impurities, particularly chlorinated compounds, is incompatible with direct introduction into step b) of FCC, the pre-treated 120°C+ cut 7 is introduced into a hydrotreating step 8. The hydrotreating step 8 is implemented in a reaction section fed by said pre-treated 120°C+ cut 7 and a gas stream including hydrogen 9, in the presence of at least one hydrotreating catalyst, and optionally an amine supplied by stream 10 and optionally a sulfur compound by stream 11, to obtain a partially hydrotreated 120°C+ cut 12. The hydrotreating step is carried out under mild operating conditions aimed essentially at removing chlorinated compounds by hydrodechlorination (formation of HCl) while preserving the olefins.

[0271] The partially hydrotreated 120°C+ cut 12 is then introduced into a separation step 13 to obtain a gaseous effluent 14 (containing in particular the unreacted hydrogen from the hydrotreatment step 8 and the HCl formed by hydrodechlorination) and a purified 120°C+ cut 15. In order to extract the HCl in the form of a liquid solution, an aqueous solution 16 is preferentially injected into the separation step, preferably upstream, in order to recover an aqueous effluent 17 containing the HCl and any salts formed.

[0272] The purified 120°C+ cut 15 is then introduced into step b) of FCC, possibly in the presence of a fossil feed and / or a feed from biomass conversion 4 in order to produce FCC products 5 (including propylene).

[0273] The 120°C-2 cut, on the other hand, can be introduced, after possibly hydrogen treatment (hydrorefining) in a steam cracking or catalytic reforming unit, or as a co-feed with a fossil feed and / or from the conversion of biomass in hydrorefining (not shown).

[0274] Only the main stages, with the principal flows, are shown in Figures 1 and 2 to facilitate a better understanding of the invention. It is understood that all the equipment necessary for operation is present (tanks, pumps, heat exchangers, furnaces, columns, etc.), even if not shown. It is also understood that hydrogen-rich gas flows (make-up or recycled), as described above, can be injected at the inlet of each reactor or catalytic bed, or between two reactors or two catalytic beds. Methods well known to those skilled in the art for hydrogen purification and recycling can also be implemented.

[0275] EXAMPLES

[0276] Examples 1 and 2 do not require chlorine specifications for an FCC in order to highlight olefin yields from a full load and a 120°C+ cut.

[0277] Example 1 (not in accordance with the invention)

[0278] The feed 1 treated in the process is a plastics pyrolysis oil (i.e. comprising 100% by weight of said plastics pyrolysis oil).

[0279] The characteristics of load 1 are shown in Table 2.

[0280] Table 2

[0281] Load 1 is not subjected to a pre-fractionation step (a) and is processed entirely in a FCC step (b). Table 3 indicates the operating conditions of the FCC step.

[0282] Table 3

[0283] Table 4 shows the yields of the FCC products processing charge 1.

[0284] Table 4

[0285] Example 2 (according to the invention)

[0286] The feed 1 processed in the process is the same plastic pyrolysis oil as in Example 1.

[0287] The feed 1 undergoes a pre-fractionation step (a) to obtain a cut 2 with a boiling point less than or equal to 120°C (120°C- cut) and a cut 3 with a boiling point greater than 120°C (120°C+ cut). The characteristics of the feed and the cuts are shown in Table 5.

[0288] Thanks to pre-fractionation at 120°C, C9+ olefins, especially C9 olefins which are present in large quantities, are preserved in the heavy 120°C+ distillate cut intended for catalytic cracking.

[0289] Thanks to pre-fractionation, certain impurities that are particularly harmful to the catalytic cracking unit become more concentrated in the light naphtha fraction. This notably concerns chlorinated compounds, silica compounds, and diolefins.

[0290] Conversely, these same compounds are deconcentrated from the heavier 120°C+ fraction, which facilitates their processing in downstream units, either directly or via coprocessing. Table 5: Characteristics of the feed and sections after pre-fractionation

[0291] Table 5

[0292] The cut 3 having a boiling point above 120°C (cut 120°C+) is subjected to a step b) of catalytic cracking under the conditions indicated in table 6.

[0293] Table 6 Table 7 shows the yields of FCC products processing cut 3 with a boiling point above 120°C (cut 120°C+).

[0294] Table 7 Compared to the non-compliant example processing feed 1 in the FCC, processing cut 3 (120°C+) in the FCC results in a 1% weight increase in propylene (C3 olefins) yield and a 1.5% weight increase in C4 olefins yield. These yields are expressed relative to the weight of the incoming FCC stream, i.e., feed 1 for the non-compliant example, or cut 3 for the compliant example. Considering the 95.05% weight yield for cut 3 (120°C+) in pre-fractionation step a), the yield of C3 and C4 olefins of interest relative to the weight of feed 1 before pre-fractionation is 1.5% weight higher than the yield of these same olefins obtained using the non-compliant example.

Claims

DEMANDS 1. A process for treating a feedstock comprising a pyrolysis oil of plastic and / or tires and / or solid recovered fuels, said process comprising the following steps: a) a pre-fractionation step of the feedstock to obtain a cut having a boiling point less than or equal to 120°C and a cut having a boiling point greater than 120°C containing olefins having 9 or more carbon atoms, b) a fluidized bed catalytic cracking step carried out in a fluidized bed catalytic cracking reaction section in a substantially vertical reactor either in upstream or downstream mode in the presence of a zeolite catalyst at a reactor temperature between 450°C and 600°C, fed by at least said cut having a boiling point greater than 120°C to produce propylene.

2. A process according to claim 1, comprising at least one pretreatment step carried out on the feed before step a) of pre-fractionation or carried out on the cut having a boiling point less than or equal to 120°C or the cut having a boiling point greater than 120°C directly after step a) of pre-fractionation, said pretreatment step comprising an adsorption step and / or a filtration step and / or a centrifugation step and / or a decantation step and / or an electrostatic separation step and / or a washing step using an aqueous solution and / or a gas stripping step.

3. A process according to any one of the preceding claims, wherein the cutting material having a boiling point above 120°C, optionally pretreated, is subjected to a hydrotreating step before step b) of catalytic fluidized bed cracking, said hydrotreating step being carried out in a hydrotreating reaction section comprising at least one hydrotreating catalyst, said hydrotreating reaction section being fed at least by the cutting material having a boiling point above 120°C, optionally pretreated, and a gas stream comprising hydrogen, said hydrotreating reaction section being carried out at an average temperature between 100 and 250°C, a partial pressure of hydrogen between 1.0 and 5.0 MPa abs. and an hourly volumetric velocity between 0.05 and 5 h' 1 , the hydrogen blanket being between 5 and 200 Nm 3 of hydrogen per m 3of charge, to obtain a cut having a boiling point above 120°C partially hydrotreated.

4. A process according to the preceding claim, wherein said hydrotreating catalyst comprises a support selected from alumina, silica, silica-aluminas, magnesia, clays and mixtures thereof, and a hydro-dehydrogenating function comprising at least one element from group VIII and / or at least one element from group VIB.

5. A process according to claims 3 or 4, wherein the partially hydrotreated cut having a boiling point above 120°C is subjected to a separation step before step b) of catalytic cracking in a fluidized bed, advantageously carried out in at least one separation section, to obtain at least one gaseous effluent and a cut having a boiling point above 120°C partially freed of its impurities.

6. A method according to the preceding claim, wherein the separation step comprises an injection of an aqueous solution.

7. A method according to any one of the preceding claims, wherein the feedstock consists of a pyrolysis oil from plastics and / or tires and / or solid recovered fuels.

8. A method according to any one of the preceding claims, wherein a co-feed selected from a fossil feed and / or a feed from biomass conversion is introduced in step b) of fluidized bed catalytic cracking.

9. A process according to the preceding claim, wherein the fossil feedstock is selected from gasoline, gas oils, vacuum gas oils, atmospheric residues, vacuum residues, atmospheric distillates, vacuum distillates, heavy fuel oils, oils, waxes and paraffins, used oils, residues or deasphalted crudes, deasphalted oils, petroleum feedstocks from thermal or catalytic conversion processes, or mixtures of such feedstocks.

10. A process according to claims 8 or 9, wherein the feedstock from biomass conversion is selected from vegetable oils, algae or algal oils, fish oils, used food oils, and fats of vegetable or animal origin; methyl esters of fatty acids of vegetable and / or animal origin, methyl esters of fatty acids from used food vegetable oils, feedstocks from thermal or catalytic biomass conversion processes, or mixtures of such feedstocks.

11. A method according to any one of the preceding claims, wherein the cut having a boiling point less than or equal to 120°C is at least partially subjected to a steam cracking step carried out in at least one pyrolysis furnace at a temperature between 700 and 900°C and at a pressure between 0.05 and 0.3 MPa relative in the presence of steam.

12. A process according to claims 1 to 10, wherein the cutting material having a boiling point less than or equal to 120°C is at least partially subjected to a catalytic reforming step in the presence of a reforming catalyst carried out at a temperature between 400 and 700°C, a pressure between 0.1 and 4 MPa, and a mass flow rate of feed treated per unit mass of catalyst per hour between 0.1 and 10 h⁻¹ 1 .

13. A method according to any one of claims 1 to 10, wherein the cut having a boiling point less than or equal to 120°C is at least partially introduced into a fuel storage unit.

14. A process according to any one of claims 11 to 13, wherein the cut having a boiling point less than or equal to 120°C is prior to the steam cracking step, the catalytic reforming step and / or its introduction into a fuel storage unit subjected to at least one hydrorefining step.

15. A process according to claims 1 to 10, wherein the cutting material having a boiling point less than or equal to 120°C is introduced as a co-feed with a fossil feed and / or a feed from the conversion of biomass in a hydrotreating or hydrocracking process.

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