PROCESS FOR PURIFYING A PLASTIC LIQUEFACTION OIL COMPOSITION BY TREATMENT IN THE PRESENCE OF SALTS OF A FLUORIDE-CONTAINING ANION

Abstract

The invention relates to a process for purifying a composition comprising a plastic liquefaction oil, including a step of contacting it with a fluorine-containing anion salt followed by a purification step. The purified composition thus obtained can then be sent for further processing such as hydrotreating, cracking, hydrocracking, and steam cracking. (Short figure: Fig. 1)

Description

Title of the invention: METHOD FOR PURIFYING A PLASTIC LIQUEFACTION OIL COMPOSITION BY TREATMENT IN THE PRESENCE OF SALTS OF AN ANION CONTAINING FLUORINE Technical field of the invention

[0001] The present invention relates to a method for purifying by treatment in the presence of salts of a fluorine-containing anion a composition comprising a plastic liquefaction oil and its subsequent use in refining and petrochemical processes. The method according to the invention makes it possible in particular to reduce the heteroatom concentration of feedstocks originating from plastic waste, in particular with a view to their use in a steam cracking process. Technological background

[0002] Plastic waste is most often directed to landfills or incinerated, and a smaller portion is directed to recycling. However, there is a significant need, encouraged by regulations, to limit plastic waste in landfills. On the other hand, the disposal of plastic waste in landfills is becoming increasingly difficult. It is therefore necessary to recycle plastic waste.

[0003] One possible way to recycle plastic is to liquefy the plastic by pyrolysis or hydrothermal liquefaction. However, the resulting plastic oil typically contains large amounts of dienes and heteroatoms, including silicon and metals. These many heteroatoms, including silicon and metals, are contaminants for the catalysts in the hydrotreatment processes usually used to recycle plastics. In addition, dienes readily react to form gums. Dienes are also precursors to coke in a steam cracker. Therefore, it is necessary to treat plastic liquefaction oils in order to recycle them.

[0004] There are many treatment processes for reducing the heteroatom content of plastic liquefaction oils.

[0005] Some of these involve heating the plastic oil in the presence of a basic compound, usually in aqueous solution.

[0006] Patent application WO2012 / 069467 claims a method for removing siloxanes contained in a plastic pyrolysis oil by heat treatment between 200 and 350°C in the presence of an alkali metal hydroxide in solid or solution form. The use of 5% by weight calcium hydroxide at 225°C does not allow to obtain a reduction in the siloxane content (Table 5, p.12 and lines 9 to 11, p.13). At the end of the reaction, the pyrolysis oil is separated by distillation under reduced pressure.

[0007] Patent FI128848 describes a process sequence comprising a heat treatment of a plastic pyrolysis oil at at least 200°C in the presence of an alkaline aqueous solution. At the end of the reaction, the pyrolysis oil is separated from the alkaline aqueous phase. A final hydrotreatment makes it possible to obtain a steam cracker feedstock which is optionally washed with an acid solution before introduction into the steam cracker.

[0008] Patent application WO2020 / 020769 claims a process sequence for purifying a composition comprising at least 20 ppm of chlorine. Many recyclable liquid wastes can be treated, including plastic pyrolysis oils. The process sequence comprises a thermal treatment of the feedstock in the presence of an alkali metal hydroxide in order to obtain a reduction of at least 50% of the chlorine content relative to the feedstock, followed by hydrotreatment in order to obtain a further reduction of at least 50% of the chlorine content.

[0009] Patent application WO2021 / 105326 claims a method for recovering liquefied plastic waste comprising a step of pretreating the liquefied plastic waste by contacting it with an aqueous medium having a pH of at least 7 at a temperature of 200°C or higher, followed by a liquid-liquid separation in which the aqueous phase is separated from the organic phase, to produce a pretreated liquefied waste plastic material. The proposed solution comprises the use of a solution of NaOH in water. The separation of the aqueous and organic phases is carried out by physical (centrifugation) or chemical methods (addition of separation aid additives, for example non-aqueous solvents, addition of additional quantity of the aqueous medium used for contacting or of an aqueous medium having a different alkaline substance concentration), or by gravity.

[0010] Most existing purification treatments are carried out at relatively high temperatures, in particular to allow efficient removal of heteroatoms and in particular silicon. If treatments in basic media allow silicon, chlorine and other heteroatoms, such as oxygen and nitrogen, to be removed with good efficiency, a loss of carbonaceous material is observed which reduces the material balance of the treatment.

[0011] There is thus a need to improve existing purification processes, and in particular to selectively eliminate silicon, and advantageously chlorine, while leaving the oxygenated compounds in the medium. Summary of the invention

[0012] The invention aims to propose a process for purifying plastic liquefaction oil making it possible to significantly reduce the quantities of heteroatoms, and in particular silicon, initially present while improving the overall material balance of the reaction in terms of carbon compounds.

[0013] For this purpose, the invention provides a method for purifying a composition comprising a plastic liquefaction oil comprising the following steps:

[0014] (a) providing a composition comprising a plastic liquefaction oil, said composition containing at least 20 ppm by mass of heteroatoms including silicon,

[0015] (b) contacting the composition of step (a) with a salt of an anion containing fluorine to obtain an effluent containing the modified composition,

[0016] (c) subjecting the effluent from step (b) to (i) washing in the presence of water or a solvent immiscible with the modified composition, (ii) distillation, (iii) purification by passage over a solid adsorbent, or a combination of two or more of steps (i), (ii), (iii), and recovering a purified composition having a reduced content of silicon and other heteroatoms.

[0017] The sequence of steps of the process according to the invention makes it possible to purify the composition to be treated, and in particular to eliminate heteroatoms and in particular silicon.

[0018] Said composition provided in step (a) of the process according to the invention may comprise at least one of the following characteristics:

[0019] - said composition contains at least 10% by weight of liquefaction oil of plastic, the other part of said composition being a diluent or said composition contains only plastic liquefaction oil,

[0020] - said plastic liquefaction oil in said composition has a point initial boiling point of at least 15°C and a final boiling point of at most 700°C, preferably at most 600°C, more preferably 560°C, preferably 450°C, more preferably 350°C, preferably 250°C,

[0021] - said plastic liquefaction oil contains more than 2 ppm by weight of metals,

[0022] - said plastic liquefaction oil contains at least 5 ppm by weight of Si, preferably at most 5000 ppm by weight of Si, and / or at least 1 ppm by weight of Si, of preferably at most 5000 ppm by weight of Si, and / or at least 1 ppm by weight of Si, of preferably at most 1000 ppm by weight of Si, and / or at least 1 ppm by weight of Cl, preferably at most 5000 ppm by weight, and / or at least 1 ppm by weight of P, of preferably at most 5000 ppm by weight relative to the total weight of said plastic liquefaction oil.

[0023] Step (b) according to the invention may comprise one or more of the following characteristics:

[0024] - prior to step (b), the first effluent is subjected to (i) filtration, (ii) a washing with water or a polar solvent immiscible with the composition, (iii) distillation, (iv) decantation, or (v) the combination of two, three or four of steps (i) to (iv),

[0025] - prior to step (b) or during step (b), the following is added to composition (i): said salt in solid form, (ii) said salt previously solubilized in an aqueous medium, preferably water, or (iii) said salt previously solubilized in an organic solvent, - the ratio of the number of moles of said salt to the number of moles of silicon present in the composition is from 3:1 to 1000:1, preferably from 4:1 to 500:1, more preferably from 5:1 to 100:1, even more preferably from 5:1 to 50:1,

[0026] - said salt comprises an anion chosen from a fluoride ion and a fluorophosphate ion, in particular a monofluorophosphate ion, and a cation chosen from an alkali metal cation, the ammonium ion and a quaternary ammonium cation,

[0027] - said salt is chosen from CsF, NaF, KF, Na2PFO3, tetra-n fluoride - butylammonium, tetramethylammonium fluoride, tetraethylammonium fluoride, tetrapropylammonium fluoride, ammonium fluoride, and mixtures thereof,

[0028] - step b) is carried out at a temperature below 250°C,

[0029] - step b) is carried out for a period of 15 minutes to 72 hours, preferably 30 minutes to 72 hours, more preferably 30 minutes to 48 hours or 30 minutes to 36 hours.

[0030] Step (c) according to the invention may comprise one or more of the following characteristics: - step (c) is preceded or followed by a step of separation of the solids by (i) filtration, (ii) centrifugation, (iii) hydrocyclone or (iv) a combination of two or more of these steps, - washing step (c) (i) is carried out in the presence of water at neutral, basic or acidic pH, or in the presence of an organic solvent immiscible with the composition, preferably in the presence of water, - purification step (c) (iii) is carried out by passing over a solid adsorbent in order to reduce the content of at least one element among F, Cl, Br, I, O, N, S, Se, Si, P, As, Fe, Ca, Na, K, Mg and Hg and / or the water content.

[0031] Advantageously, the purified composition of step (c) may undergo (d) a catalytic hydrotreatment, namely a catalytic treatment under hydrogen, in one or two stages to provide a hydrotreated purified composition.

[0032] The hydrotreatment of step (d): - can be carried out in a single step in which the purified composition of step (c) is hydrotreated at a temperature of 200 to 450°C, preferably from 200 to 340°C in the presence of hydrogen at an absolute pressure of 20 to 160 bars, preferably 30 to 100 bars and in the presence of at least one hydrotreatment catalyst, or - can be carried out in a first step (d-1) in which the purified composition of step (c) is hydrotreated, preferably selectively hydrogenated, at a temperature of 80 to 250°C, preferably 130 to 250°C in the presence of hydrogen at an absolute pressure of 5 to 60 bars, preferably 20 to 50 bars and in the presence of at least one first hydrotreatment catalyst, and in a second step (d-2) in which the effluent from step (d-1) is hydrotreated at a temperature of 200 to 450°C, preferably 250 to 340°C in the presence of hydrogen at an absolute pressure of 20 to 160 bars, preferably 30 to 100 bars and in the presence of at least one second hydrotreatment catalyst.

[0033] Advantageously, the purified and hydrotreated composition leaving step (d) can also be washed with water to remove inorganic compounds such as hydrosulfide, hydrogen chloride, ammonia.

[0034] Advantageously, the purified composition of step (c), or the hydrotreated purified composition of step (d) optionally washed with water, can be used as such or separated into streams usable for the preparation of fuels and combustibles such as LPG, gasoline, diesel, heavy fuel oil, kerosene and / or for the preparation of lubricants and / or base oils.

[0035] Advantageously, the purified composition of step (c), or the hydrotreated purified composition of step (d) optionally washed with water, can be treated, pure or diluted, optionally after separation into usable streams, in a steam cracker to produce olefins, and / or a fluidized bed catalytic cracker, and / or a hydrocracker, then optionally in a steam cracker, and / or a hydrotreatment reactor, in particular a catalytic hydrogenation reactor.

[0036] Preferably the purified composition of step (c), or the hydrotreated purified composition of step (d) optionally washed with water, can be subjected, pure or diluted, optionally after separation into usable streams, to a steam cracking step to produce olefins such as ethylene and propylene, which can then be used to manufacture new polymers by polymerization.

[0037] Advantageously, step a) may comprise the preliminary step a1) of providing a plastic waste stream; a2) liquefying said plastic waste stream by pyrolysis or hydrothermal liquefaction at a temperature of at least 200°C; a3) recovering a liquefaction effluent and separating said liquefaction effluent into a C1 to C4 hydrocarbon fraction and a remaining fraction forming said plastic liquefaction oil; a4) optionally mixing said remaining fraction with a solvent or thinner.

[0038] The previously described steps of the method according to the invention can be implemented one after the other without an intermediate step except for the optional additional steps described. Definitions

[0039] For the purposes of the description, the following definitions are given:

[0040] The terms "comprising" and "comprises" as used herein are synonymous with "including," "includes," or "contains," "containing," and are inclusive or unbounded and do not exclude additional features, elements, or method steps not specified.

[0041] The specification of a numeric domain without decimals includes all whole numbers and, where appropriate, fractions thereof (e.g., 1 to 5 may include 1, 2, 3, 4, and 5 when referring to a number of elements, and may also include 1.5, 2, 2.75, and 3.80, when referring to, for example, a measurement.).

[0042] The specification of a decimal also includes the decimal itself (e.g., "from 1.0 to 5.0" includes 1.0 and 5.0). Any range of numeric values ​​recited herein also includes any subrange of numeric values ​​mentioned above.

[0043] The expressions % by weight and % by mass have an equivalent meaning and refer to the proportion of the mass of a product relative to 100g of a composition comprising it.

[0044] Unless otherwise indicated, measurements given in parts per million (ppm) are expressed by weight.

[0045] The terms "alkane" or "alkanes" as used herein describe branched or unbranched acyclic hydrocarbons having the general formula CnH2n+2, and thus consisting entirely of hydrogen atoms and saturated carbon atoms; see, for example, IUP AC. Compendium of Chemical Terminology, 2nd ed. (1997). The term "alkanes" therefore refers to unbranched alkanes ("normal paraffins" or "n-paraffins" or "n-alkanes" or "paraffins") and branched alkanes ("iso-paraffins" or "iso-alkanes"), but excludes naphthenes (cycloalkanes). They are sometimes designated by the symbol "HC-".

[0046] The terms "olefin" or "alkene" as used herein denote an unsaturated hydrocarbon compound containing at least one carbon-carbon double bond. They are sometimes denoted by the symbol "HC=".

[0047] The term "alkyne" as used herein refers to an unsaturated hydrocarbon compound containing at least one carbon-carbon triple bond.

[0048] The term "hydrocarbon" refers to alkanes (saturated hydrocarbons), cycloalkanes, aromatics and unsaturated hydrocarbons.

[0049] Hourly Volume Velocity (WH) is defined as the hourly volume of flow of charge per unit of catalytic volume and is expressed here in h *.

[0050] By "heteroatom" is meant any element of an organic compound other than carbon and hydrogen.

[0051] The heteroatom concentration in the hydrocarbon matrix can be determined by any method known in the art. In particular, relevant characterization methods include X-ray fluorescence (XRF), inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma atomic emission spectrometry (ICP-AES). Analytical scientists know how to identify the most suitable method for measuring each metal and generally each heteroelement depending on the hydrocarbon matrix considered. The oxygen content can be measured according to the standard: ASTM D5622-17 / D2504-88(2015). The nitrogen content can be measured according to the standard: ASTM D4629-17. The sulfur content can be measured according to the standard ISO 20846:2011. The content of halogens, including chlorine, bromine, fluorine, can be measured according to the standard: ASTM D7359-18.

[0052] Diene Value (DV) or Maleic Anhydride Value (MAV) is the amount of maleic anhydride (expressed as iodine equivalents) that reacts with 100 parts of oil under specific conditions. It is a measure of the conjugated double bonds in the oil. One mole of maleic anhydride corresponds to one conjugated double bond. A known method for quantifying diene is UOP 326-17: Diene Value by Maleic Anhydride Addition Reaction. The term "diene value" (DV) refers to the analytical method by titration expressed as g of iodine per 100 g of sample. The term maleic anhydride value (MAV) refers to the analytical method by titration expressed in mg of maleic acid per g of sample. There is a correlation between MAV = DV *3.863 since 2 moles of iodine correspond to 1 mole of maleic anhydride.

[0053] The term "Bromine Number" refers to the amount of bromine in grams reacted per 100 g of sample. This number indicates the amount of olefins in a sample. It is determined in grams of Br2 per 100 grams of solution (gBr2 / 100g) and can be measured according to ASTM DI 159-07, reapproved in 2017.

[0054] The term "Bromine Index" is the number of milligrams of bromine that react with 100 g of sample. It is determined as milligrams of Br2 per 100 g of solution (mg Br2 / 100g) and can be measured according to ASTM D2710 or ASTM D5776 methods.

[0055] Boiling points as mentioned herein are measured at atmospheric pressure unless otherwise stated. An initial boiling point is defined as the temperature value at which a first vapor bubble is formed. A Final boiling point is the highest temperature achievable during distillation. At this temperature, no more vapor can be transported to a condenser. The determination of the initial and final points uses techniques known in the trade and several methods adapted according to the distillation temperature range are applicable, for example NF EN 15199-1 (2020 version) or ASTM D2887 for the measurement of boiling points of petroleum fractions by gas chromatography, ASTM D7169 for heavy hydrocarbons, ASTM D7500, D86 or DI 160 for distillates.

[0056] The expression "polar solvent" within the meaning of the present patent application covers all chemical species, alone or in mixture, comprising at least one carbon-hydrogen, carbon-halogen, carbon-chalcogen or carbon-nitrogen covalent bond and having a non-zero dipole moment. It is understood that the term "polar solvent" within the meaning of the present definition specifically excludes water.

[0057] The term "solvent" includes the aforementioned "polar solvents" and non-polar solvents, which include, for example, any type of linear, branched, cyclic and / or aromatic saturated or unsaturated hydrocarbon such as pentane, cyclohexane, olefins, toluene or xylene or certain other solvents with zero or almost zero dipole moment such as tetrachloromethane or carbon disulfide.

[0058] The term "naphtha" refers to the general definition used in the oil and gas industry. In particular, it is a hydrocarbon derived from the distillation of crude oil and whose boiling point is between 15 and 250°C, according to ASTM D2887. Naphtha contains virtually no olefins because the hydrocarbons are derived from crude oil. It is generally considered that a naphtha has a carbon number between C5 and Cl 1, although the carbon number can reach Cl5 in some cases. It is also generally accepted that the density of naphtha is between 0.65 and 0.77 g / mL.

[0059] The term "liquefaction oil" means an oil resulting from a pyrolysis process and / or a hydrothermal liquefaction process of a hydrocarbon feedstock. This hydrocarbon feedstock may comprise plastics, biomass and / or elastomers, alone or in a mixture, in particular in the form of waste. A liquefaction oil may be formed from a mixture of two or more liquefaction oils resulting from the liquefaction of different hydrocarbon feedstocks.

[0060] The pyrolysis process must be understood as a thermal cracking process, typically carried out at a temperature of 300 to 1000°C or 400 to 700°C, carried out in the presence or absence of a catalyst and / or a gas (fast pyrolysis, flash pyrolysis, catalytic pyrolysis, hydropyrolysis, steam pyrolysis, etc.).

[0061] The hydrothermal liquefaction process (or HTL for "Hydrothermal Liquefaction" in English) is a thermochemical conversion process using water as a solvent, reagent and catalyst for the degradation reactions of a hydrocarbon feedstock, water typically being in a subcritical or supercritical state. The hydrothermal liquefaction process is typically carried out at a temperature of 250 to 500 °C and at pressures of 10 to 25-40 MPa in the presence of water.

[0062] The expression "plastic liquefaction oil" or "oil resulting from the liquefaction of plastic" or "plastic waste liquefaction oil" or "plastic oil" refers to the liquid hydrocarbon products obtained at the end of pyrolysis or hydrothermal liquefaction of plastics, namely thermoplastic and / or thermosetting polymers, alone or in a mixture, and generally in the form of waste, optionally in a mixture with at least one other filler, in particular in the form of waste, such as biomass, for example chosen from lignocellulosic biomass, paper and cardboard, and / or an elastomer, for example possibly vulcanized latex or tires.

[0063] The plastic can be of any type, including any type of new or used plastic, included in household (post-consumer) or industrial waste. Plastics are understood to mean materials consisting of polymers and optionally auxiliary components such as plasticizers, fillers, colorants, catalysts, flame retardants, stabilizers, etc. For example, these polymers can be polyethylene, halogenated polyethylene (Cl, F), polypropylene, polystyrene, polybutadiene, polyisoprene, poly(ethylene terephthalate) (PET), acrylonitrile-butadiene-styrene (ABS), polybutylene, poly(butylene terephthalate) (PBT), polyvinyl chloride (PVC), polyvinylidene chloride, a polyester, a polyamide, a polycarbonate, a polyether, an epoxy polymer, a polyacetal, a polyimide, a polyesteramide, silicone, etc.Generally speaking, any polymer or mixture of polymers capable of producing hydrocarbons by liquefaction can be used.

[0064] Biomass can be defined as an organic plant or animal product. Biomass thus includes (i) biomass produced by surplus agricultural land, not used for human or animal food: dedicated crops, called energy crops; (ii) biomass produced by deforestation (forest maintenance) or the clearing of agricultural land; (iii) agricultural residues from cereal crops, vines, orchards, olive trees, fruits and vegetables, agri-food residues, etc.; (iv) forest residues from forestry and wood processing; (v) agricultural residues from livestock farming (manure, slurry, bedding, droppings, etc.); (vi) household organic waste (paper, cardboard, green waste, etc.); (vii) ordinary industrial organic waste (paper, cardboard, wood, putrescible waste, etc.).The plastic liquefaction oil treated by the invention may come from the liquefaction of waste containing at least 1% m / m, optionally from 1 to 50% m / m, from 2 to . 30%m / m or within a range defined by any two of these limits, of one or more of the aforementioned biomasses, residues and organic waste, and the remainder consisting of plastic waste, optionally mixed with elastomers, in particular in the form of waste.

[0065] Elastomers are linear or branched polymers transformed by vulcanization into a weakly crosslinked, infusible and insoluble three-dimensional network. They include natural or synthetic rubbers. They may be part of tire-type waste or any other household or industrial waste containing elastomers, natural and / or synthetic rubber, whether or not mixed with other components, such as plastics, plasticizers, fillers, vulcanizing agents, vulcanization accelerators, additives, etc. Examples of elastomeric polymers include ethylene-propylene copolymers, ethylene-propylene-diene terpolymer (EPDM), polyisoprene (natural or synthetic), polybutadiene, styrene-butadiene copolymers, isobutene-based polymers, isobutylene isoprene copolymers, chlorinated or brominated, butadiene acrylonitrile copolymers (NBR), and polychloroprenes (CR), polyurethanes, silicone elastomers, etc.The plastic liquefaction oil treated by the invention may come from the liquefaction of waste containing at least 1% m / m, optionally from 1 to 50% m / m, from 2 to 30% m / m or in a range defined by any two of these limits, of one or more of the aforementioned elastomers, in particular in the form of waste, the remainder being made up of plastic waste, optionally mixed with biomass, residues and organic waste.

[0066] By "hydrotreatment" is meant any process during which hydrocarbons react with dihydrogen, typically under pressure, in the presence of a catalyst or not. Hydrotreatment may thus comprise one or more reactions chosen from hydrodesulfurization (HDS), hydrodenitrogenation (HDN), hydrodeoxygenation (HDO), hydrodemetalation (HCM), hydrocracking, hydroisomerization and hydrogenation (hydrogenation of unsaturated compounds into saturated compounds).

[0067] By "hydrotreatment catalyst" is meant a catalyst promoting the incorporation of hydrogen into the products. This type of catalyst is typically a metal catalyst comprising one or more metals from groups 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 and 14 of the periodic table.

[0068] The particular features, structures, properties, embodiments of the invention may be freely combined into one or more embodiments not specifically described herein, as may be apparent to those skilled in the art in the processing of plastic liquefaction oils using their general knowledge. Detailed description of the invention

[0069] Description of the composition comprising a plastic liquefaction oil

[0070] The composition provided in step (a) comprises a plastic liquefaction oil.

[0071] In one embodiment, the composition may comprise only a plastic liquefaction oil, in particular only a plastic pyrolysis oil or only a plastic hydrothermal liquefaction oil.

[0072] Alternatively, the composition may comprise at least 1 wt% of plastic liquefaction oil. The remainder may then be composed of at most 99 wt% of a diluent or solvent such as a hydrocarbon, and / or one or more of the components listed below, preferably a component derived from biomass, biomass waste or elastomeric waste.

[0073] In one embodiment, the composition may comprise at least 5% by weight, preferably 10% by weight, more preferably at least 25% by weight, even more preferably at least 50% by weight, more preferably 75% by weight, even more preferably at least 90% by weight of plastic liquefaction oil. The composition may comprise at most 80% by weight or 90% by weight or 95% by weight or 100% by weight of plastic liquefaction oil. The mass content of plastic liquefaction oil(s) in the composition may be within any range defined by two of the limits previously set.

[0074] The composition may further comprise a component derived from biomass, biomass waste or elastomeric waste, such as tall oil, used edible oil, animal fat, vegetable oil such as rapeseed, canola, castor, palm, soybean oil, oil extracted from algae, oil extracted from fermentation of oleaginous microorganisms such as oleaginous yeasts, biomass liquefaction oil, in particular biomass liquefaction oil such as Panicum virgatum or lignocellulosic biomass liquefaction oil, for example wood, paper and / or cardboard liquefaction oil, oil obtained by liquefaction of crushed used furniture, elastomer liquefaction oil for example optionally vulcanized latex or tires, and mixtures thereof.

[0075] The composition may further comprise a diluent miscible with the plastic liquefaction oil. This diluent preferably has a diene number of at most 0.5 g I2 / 100 g, measured according to UOP 326, a bromine number of at most 5 g Br2 / 100 g measured according to ASTM DI 159. The diluent is preferably selected from a naphtha and / or a paraffinic solvent and / or a straight-run diesel or gas oil, containing at most 1% by weight of sulfur, preferably at most 0.1% by weight of sulfur, and / or a hydrocarbon stream having a boiling range between 50°C and 150°C or an in boiling range between 150°C and 250°C or a boiling range between 200°C and 350°C, preferably having a bromine index of at most 5 gBr2 / 100g, and / or a diene index of at most 0.5 gI2 / 100g, and / or the effluent from the optional hydrotreatment step of the process according to the invention, or any combination thereof.

[0076] The diluent may be added at a concentration of at most 80% by weight, preferably at most 50% by weight. Optionally, the diluent may be separated at the outlet of the optional hydrotreatment step by flash or by distillation and, preferably, recycled to the inlet of this hydrotreatment step.

[0077] The composition provided in step (a) may have a bromine index of at most 150 g Br2 / 100g, preferably at most 100 g Br2 / 100g, even more preferably at most 80 g Br2 / 100g, most preferably at most 50 g Br2 / 100g, as measured according to ASTM DI 159. The composition may further have a heteroatom content of at least 20 ppm.

[0078] In the composition provided in step (a), at least 10% by weight, preferably at least 15% by weight, preferably at least 25% by weight, more preferably at least 50% by weight of said composition has a boiling point of at least 150°C relative to the total weight of said composition.

[0079] Step (a) of providing the composition may comprise:

[0080] (al) a step of providing a stream of plastic waste,

[0081] (a2) a step of liquefying waste containing plastics and obtaining a hydrocarbon product comprising a gaseous phase, a liquid phase and a solid phase,

[0082] (a3) ​​a step of recovering the liquefaction effluent and separating the liquid phase of said product, said liquid phase forming a plastic liquefaction oil,

[0083] (a4) an optional step of mixing the plastic liquefaction oil with a thinner or solvent.

[0084] The liquefaction step (a2) may comprise a pyrolysis step, typically carried out at a temperature of 300 to 1000°C or 400 to 700°C, this pyrolysis being for example a rapid pyrolysis or a flash pyrolysis or a catalytic pyrolysis or a hydropyrolysis.

[0085] Alternatively or in combination, the liquefaction step (a2) may comprise a hydrothermal liquefaction step, typically carried out at a temperature of 250 to 500°C and at pressures of 10 to 25-40 MPa.

[0086] The waste supplied in step (al) may be plastic waste optionally mixed with biomass and / or elastomers, as previously described.

[0087] The recovery and separation step (a3) ​​makes it possible to eliminate the gaseous phase, essentially the C1-C4 hydrocarbons and the solid phase (typically char) to recover only the liquid organic phase (also called “remaining fraction” in the present application) forming a liquefaction oil.

[0088] Plastic liquefaction oils contain, in particular, paraffins, i-paraffins (iso-paraffins), dienes, alkynes, olefins, naphthenes and aromatics. Plastic liquefaction oils also contain impurities containing heteroatoms, such as chlorinated, oxygenated, sulfurous, nitrogenous and / or silylated organic compounds, metals, salts, phosphorus compounds.

[0089] The composition of the plastic liquefaction oil depends on the nature of the liquefied plastic, and optionally on any other waste (biomass and / or elastomers) liquefied with the plastic, and is essentially (in particular at more than 80% m / m, most often at more than 90% m / m) made up of hydrocarbons having from 1 to 150 carbon atoms and impurities.

[0090] A plastic liquefaction oil typically comprises from 5 to 80% m / m of paraffins (including cycloparaffins), from 10 to 95% m / m of unsaturated compounds (including olefins, dienes and acetylenes), from 5 to 70% m / m of aromatics. These contents can be determined by gas chromatography.

[0091] In particular, a plastic liquefaction oil may comprise a Bromine number of 10 to 130 g Br / 100 g, as measured according to ASTM DI 159, and / or a maleic anhydride number (UOP 326) of 1 to 55 mg maleic anhydride / 1 g.

[0092] A plastic liquefaction oil may have a diene index of at most 50 gI2 / 100 g, preferably at most 25 gI2 / 100 g, more preferably at most 10 gI2 / 100 g, measured according to the UOP 326 standard. A plastic liquefaction oil may typically have a diene index of at least 0.5 g I2 / 100 g measured according to the UOP326 standard.

[0093] In a preferred embodiment, said plastic liquefaction oil has an initial boiling point of at least 15°C, generally at least 80°C, and a final boiling point of at most 700°C, preferably at most 600°C, even more preferably at most 560°C, more preferably at most 450°C, even more preferably at most 350°C, preferably at most 250°C (measured according to NFEN 15199-1 / 2).

[0094] A plastic liquefaction oil typically comprises at least 20 ppm of heteroatoms, or even at least 30 ppm of heteroatoms, including silicon.

[0095] A plastic liquefaction oil may in particular further comprise one or more of the following heteroatom contents: from 0 to 8% m / m of oxygen (e.g. measured according to ASTM D5622), from 1 to 13000 ppm of nitrogen (e.g. measured according to ASTM D4629), from 2 to 10000 ppm of sulfur (e.g. measured according to ISO 20846), from 1 to 10000 ppm of metals, in particular more than 2 ppm (e.g. measured by ICP), 50 to 6000 ppm chlorine, preferably at most 5000 ppm (e.g. measured according to ASTM D7359-18), 0 to 200 ppm bromine (e.g. measured according to ASTM D7359-18), 1 to 40 ppm fluorine (e.g. measured according to ASTM D7359-18), 1 to 2000 ppm silicon, preferably at most 1000 ppm (e.g. measured by XRF), at least 1 ppm P, preferably at most 5000 ppm P.

[0096] Detailed description of the optional step of processing the composition provided in step (a)

[0097] Between step (a) and (b), the invention may also comprise an optional pretreatment step, in which the composition is subjected, in particular immediately before step (v), to (i) filtration, (ii) washing with water or a polar solvent immiscible with the composition, (iii) distillation, (iv) decantation, or (v) the combination of two, three or four of steps (i) to (iv). This additional step may make it possible to reduce some of the impurities contained in the composition such as oxygen, nitrogen, chlorine, sulfur or other heteroatoms. In particular, the reduction in the amount of oxygen may make it possible to avoid the formation of solids and / or gels during a subsequent hydrotreatment step.

[0098] In the additional washing step (ii), the polar solvent or water / composition volume ratio may be from 1 / 99 to 90 / 10, from 10 / 90 to 90 / 10, from 20 / 80 to 80 / 20, from 30 / 70 to 70 / 30, from 35 / 65 to 65 / 35, from 35 / 65 to 60 / 40, or from 40 / 60 to 60 / 40.

[0099] When water is used for washing (ii), it may have an acidic, basic or neutral pH. An acidic pH may be obtained by the addition of one or more organic or inorganic acids. Examples of suitable organic acids include citric acid (C6H8O7), formic acid (CH2O2), acetic acid (CH3COOH). Examples of inorganic acids are sulfamic acid (H3NSO3), hydrochloric acid (HCl), nitric acid (HNO3), sulfuric acid (H2SO4), phosphoric acid (H3PO4). A basic pH can be achieved by the addition of alkali and alkaline earth metal oxides, alkali and alkaline earth metal hydroxides (e.g. NaOH, KOH, Ca(OH)2), alkali and alkaline earth metal bicarbonates and amines (e.g. triethylamine, ethylenediamine, ammonia).

[0100] The polar solvent may have a density greater or less than the density of the composition comprising a plastic liquefaction oil.

[0101] In particular, the density of the polar solvent may be 3 to 50% higher or lower than that of the composition.

[0102] The polar solvent is a solvent immiscible with the composition comprising a plastic liquefaction oil to be purified.

[0103] For example, it may be considered that the polar solvent (or a mixture of polar solvents where appropriate) is immiscible when its recovery rate is greater than or equal to 0.95. This recovery rate is defined as the ratio of the volume of extract over the initial volume of solvent, this extract being a phase containing the solvent, immiscible with the composition containing a liquefaction oil, recovered after stirring then decanting a mixture of one part by volume of solvent with twenty-five parts by volume of the composition containing a liquefaction oil to be purified, at atmospheric pressure and at a temperature of 20°C.

[0104] This recovery rate can be determined in particular by following the following procedure: • Introduction of 50 mL of composition containing a liquefaction oil into a flat-bottomed flask with a volume of 100 mL, using a precision pipette of + / -0.5 mL, • Introduce 2 mL of solvent into the flask, using a precision pipette + / -0.1 mL, • Insert a magnetic bar, close the balloon with a polypropylene stopper, • Stir the mixture on a mechanical stirrer plate at a speed of 500 rpm for 5 min, • At the end of 5 minutes, stop stirring, remove the magnetic bar using a magnetic rod, • Transfer the contents of the flask into a graduated tube with an accuracy of + / -0.05 mL for a volume less than or equal to 2 mL and an accuracy of + / -0.1 mL for a volume greater than 2 mL. Wait for complete demixing by decantation and measure the volume of the 2 phases using the graduations. Complete demixing is considered to be achieved when the volumes of the two phases no longer vary.

[0105] Acceptable immiscible polar solvents include (i) sulfur compounds, for example dimethyl sulfoxide, (ii) nitrogen compounds, for example A, A-dimethylformamide, (iii) halogenated compounds, for example dichloromethane or chloroform, (iv) ethylene glycol, or: - glycol ethers, including in particular polyethylene glycol of chemical formula HO-(CH2-CH2-O)nH with a mass average molar mass of 90 to 800g / mol, for example diethylene glycol and tetraethylene glycol, polypropylene glycol of chemical formula H[OCH(CH3)CH2]nOH with a mass average molar mass of 130 to 800g / mol, for example dipropylene glycol and tetrapropylene glycol, - dialkyl formamides, in which the alkyl group may comprise from 1 to 8 or from 1 to 3 carbon atoms, in particular dimethyl formamide (DMF), - dialkyl sulfoxides, in which the alkyl group may comprise from 1 to 8 or from 1 to 3 carbon atoms, in particular dimethyl sulfoxide (DMSO) and sulfolane - compounds comprising a furan ring, - cyclic carbonate esters, comprising in particular from 3 to 8 or from 3 to 4 carbon atoms, in particular propylene carbonate and ethylene carbonate.

[0106] One or more of the above-mentioned solvents may be used. However, advantageously, only one of the above-mentioned solvents may be used provided that it is immiscible with the composition containing a liquefaction oil to be purified.

[0107] Preferably, the polar solvent may be ethylene glycol or a glycol ether, in particular polyethylene glycol of chemical formula HO-(CH2-CH2-O)nH with a mass average molar mass of 90 to 800g / mol or polypropylene glycol of chemical formula H[OCH(CH3)CH2]nOH with a mass average molar mass of 130 to 800g / mol, or a compound comprising a furan ring, or a cyclic carbonate ester, in particular propylene or ethylene carbonate, alone or as a mixture, preferably alone.

[0108] In a preferred embodiment, the polar solvent is chosen from propylene carbonate, ethylene carbonate, ethylene glycol and polyethylene glycol of chemical formula HO-(CH2-CH2-O)nH with a mass average molar mass of 90 to 800g / mol, alone or as a mixture, preferably alone.

[0109] Description of step fb) of treatment with a salt of a fluorine-containing anion

[0110] Step (b) is a step of treating the composition provided in step (a) in the presence of a salt of a fluorine-containing anion to obtain an effluent containing the modified composition.

[0111] This treatment makes it possible in particular to modify compounds containing hetero- atoms, and in particular those containing silicon, and to promote their subsequent elimination. In particular, despite the complexity of the hydrocarbon matrix, the presence of fluoride ions seems to lead to the breaking of at least some of the Si-O bonds present in the hydrocarbon matrix to form other silicon compounds, such as alkylsilanes, arylsilanes, alkylarylsilanes, which can then be eliminated. This treatment is thus more selective than treatments in basic media, which can improve the material balance.

[0112] The salt may be added to the composition provided in step (a) either before step (b) or during step (b).

[0113] The salt may be added to the composition in solid form or dissolved in an aqueous medium, preferably water, or else dissolved in a solvent, miscible or immiscible with said composition.

[0114] A miscible solvent that can be used may be a polar solvent comprising an alcohol function and / or an ether function, ideally chosen from C1 to C4 alcohols, preferably among methanol, ethanol, propan-1-ol, propan-2-ol, butan-1-ol, butan-2-ol, 2-methylpropan-1-ol, propylene glycol.

[0115] A usable immiscible solvent may be an immiscible polar solvent, for example those cited for the optional pre-treatment step.

[0116] In one embodiment, the solvent may be chosen from tetrahydrofuran (THF), DMSO, sulfolane, α,α-dimethylformamide, pyridine, water.

[0117] The amount of salt used to treat the composition may advantageously be chosen so that the number of moles of anions containing fluorine is greater than the number of moles of silicon present in the composition to be treated.

[0118] In one embodiment, the ratio of the number of moles of said salt to the number of moles of silicon present in the composition may advantageously be from 3:1 to 1000:1, preferably from 4:1 to 500:1, more preferably from 5:1 to 100:1, even more preferably from 5:1 to 50:1.

[0119] The salt used in this step is capable of forming fluoride ions or fluorine-containing anions.

[0120] For example, a salt comprising a fluoride ion (F) or a fluorophosphate ion, in particular a monofluorophosphate ion (FPO3), may be selected. The counterion may advantageously be an alkali metal cation (for example Cs+, Na+, K+), the ammonium ion (NH4+) or a quaternary ammonium cation (for example a tetramethylammonium cation (TMA+), tetraethylammonium cation (TEA+), tetrapropylammonium cation (TPA+), tetrabutylammonium cation (TBA+ of formula N(CH3CH2CH2CH2) 4+)*

[0121] In one embodiment, the salt is chosen from cesium fluoride (CsF), sodium fluoride (NaF), potassium fluoride (KF), sodium monofluorosulfate (Na2PFO3), tetra-n-butylammonium fluoride of formula (CH3CH2CH2CH 2)4NF also noted TB AF, tetramethylammonium fluoride (TMAF), tetraethylammonium fluoride (TEAF), tetrapropylammonium fluoride (TPAF), ammonium fluoride (NH4F), and mixtures thereof, preferably TB AF.

[0122] When the salt is dissolved in a solvent, a temperature lower than the boiling point of the solvent at the pressure considered may be chosen for the implementation of step (b).

[0123] Step (b) may typically be carried out at a temperature below 250°C, although higher temperatures are possible depending on the solvent used.

[0124] Step (b) may in particular be carried out at a temperature ranging from room temperature to a temperature below 250°C. In one embodiment, step (b) may be carried out without the use of external heating. In another embodiment, step (b) may be carried out at a temperature of at least 50°C, and preferably at most 250°C.

[0125] The duration of contacting the salt with the composition may be from 15 minutes to 72 hours, preferably from 30 minutes to 72 hours, more preferably from 30 minutes to 48 hours or from 30 minutes to 36 hours, for example from 30 minutes to 25 hours or in any interval defined by two of these limits.

[0126] Treatment step (b) may be carried out at atmospheric pressure.

[0127] The treatment of step (b) can be carried out in any device allowing contact between the salt and the composition. This can be a reactor, preferably equipped with a mixing device or a liquid-liquid extraction column.

[0128] Step (b) may further be carried out under turbulent regime conditions or under cavitation conditions, in particular hydrodynamic cavitation, in order to improve mixing while reducing the contact time.

[0129] The turbulent regime is obtained when the flow has a Reynolds number of at least 2000, preferably at least 3000, more preferably at least 4000, or even at least 10000. The turbulent regime can advantageously be achieved by using at least one static mixer. That is to say, the composition and the aqueous medium are introduced into at least one tube equipped with at least one internal element capable of generating the turbulent regime having a Reynolds number of at least 2000.

[0130] Hydrodynamic cavitation occurs in all hydraulic systems in which considerable pressure differences occur, such as turbines, pumps, and high-pressure nozzles. The effective conditions for generating cavitation characteristics depend on the properties of the fluid flow, the design of the cavitation device, the flow velocity, e.g., achieved by a pump, the temperature of the fluid flow, and can be readily determined by those skilled in the art. A suitable hydrodynamic cavitation device may have a throttling (constriction) section formed by a plate having one or more orifices, a venturi tube, a rotor-stator system, or a liquid whistle. Instead of a constriction section, a vortex diode having a tangential inlet and an axial outlet may also be used to generate the cavitation bubbles.Examples of usable technologies include vortex-type hydrodynamic cavitation generators, such as the VoDca® generator from Water Knight in the Netherlands, a high-pressure homogenizer, e.g. the Sonolator® high-pressure homogenizers, and rotor-stator rotating equipment, e.g. the Rotocav® from Cavimax in the UK.

[0131] Detailed description of the optional additional step of separating the solids

[0132] Step (c) may be preceded or followed by a step of separating the solids by (i) filtration, (ii) centrifugation, (iii) hydrocyclone or (iv) a combination of two or three of these steps. This solids separation step can facilitate phase separation in step (c) by removing all or part of the solids present in the effluent from step (b). Detailed description of step (c)

[0133] During step (c), the effluent from step (b) is (i) subjected to washing with water at neutral, basic or acidic pH, or with a solvent immiscible with the modified composition, (ii) distillation, (iii) purification by passage over a solid adsorbent, or to a combination of two or more of steps (i), (ii), (iii).

[0134] This step is a purification step making it possible to recover a phase containing the purified composition having a reduced content of heteroatoms, and in particular at least silicon, and advantageously a reduced content of other heteroatoms, and in particular chlorine, nitrogen, oxygen.

[0135] Step (c) may comprise a washing step (i) making it possible to recover a phase containing the purified composition and a phase containing the water or the immiscible solvent used for washing, the salt and the impurities.

[0136] In other words, at the end of the washing step, these phases are recovered separately, for example following a liquid / liquid separation (centrifugation and / or decantation and / or other) carried out at the end of the washing step.

[0137] This step (i) makes it possible to eliminate the impurities containing heteroatoms, and in particular silicon, present in the effluent leaving step (b) by solubilizing them in a solvent (water or an organic solvent).

[0138] The water used in step (c) may have an acidic pH (pH<7), basic (pH >7) or neutral (pH=7), preferably a neutral pH.

[0139] In one embodiment, the water used has an acidic or neutral pH. In particular, the water used does not contain a basic compound and in particular does not contain a basic compound comprising an alkali metal or alkaline earth metal cation.

[0140] An acidic pH may be obtained by adding one or more organic or inorganic acids. Examples are cited with reference to washing (ii) of the optional pre-treatment step. Preferably, the water may have a pH of 0.1 to 6.9.

[0141] A basic pH may be obtained by adding a basic compound, for example those mentioned above with reference to washing (ii) or those used in step c). Preferably, the water may have a pH of 7.1 to 14.

[0142] The immiscible solvent may be any organic solvent immiscible with the treated effluent, in particular in which the impurities containing heteroatoms are soluble. A usable immiscible solvent is for example a polar solvent, in particular those described in the optional pre-treatment step.

[0143] Step (c) may be carried out at a temperature of 10°C to 120°C, preferably 15°C to 95°C, more preferably 15°C to 80°C, or in any range defined by any two of these limits, advantageously without external heating. Step (c) is typically carried out at atmospheric pressure.

[0144] During step (c), the solvent or water / effluent volume ratio may be from 1 / 99 to 90 / 10, from 20 / 80 to 80 / 20, from 30 / 70 to 70 / 30, from 35 / 65 to 65 / 35, from 35 / 65 to 60 / 40, from 40 / 60 to 60 / 40, or in any interval defined by any two of the above-mentioned limits.

[0145] Step (c) may comprise, or consist of, bringing the effluent from step (b) into contact with water or an immiscible solvent by any means known in the prior art.

[0146] For example, the effluent from step (b) and the solvent or water may be introduced into tanks, reactors or mixers commonly used in the profession and the two components may be mixed. The contacting may comprise vigorous agitation of the two components by a mixing device. For example, the two components may be mixed together by stirring or shaking. Alternatively, the contacting may be carried out in an enclosure in which the two components circulate countercurrently, for example in contact columns with suitable packing in order to increase the contact between the phase of the composition being treated and the water or an immiscible solvent. Alternatively, the contacting may be carried out in a static mixer in cocurrent mode or in a cavitation section.

[0147] This contacting can occur more than once, in particular under the conditions presented above. For example, two or more washes can be carried out, for example two to four washes.

[0148] The washing step (c) (i) can be carried out continuously or in batch.

[0149] Step (c) may comprise a distillation step (ii). Those skilled in the art will know carrying out this step under conditions suitable for recovering the purified composition. Distillation step (ii) may be carried out at atmospheric pressure or under reduced pressure, preferably at atmospheric pressure. This step may be carried out in a distillation column or the like.

[0150] Step (c) may also comprise a step (iii) of purification by passage over a solid adsorbent. This is thus a trapping step.

[0151] The modified composition resulting from step (b) can be purified by passing it over a solid adsorbent in order to reduce the content of at least one element among F, Cl, Br, I, O, N, S, Se, Si, P, As, Fe, Ca, Na, K, Mg and Hg and / or the water content.

[0152] Typically, the modified composition of step (b) may be contacted with silica gel, clays, alkali or alkaline earth metal oxide, oxide iron, ion exchange resins, activated carbon, activated aluminum oxide, molecular sieves, alkali oxide and / or porous supports containing modified or unmodified layered double hydroxide and silica gel, or any mixture thereof for trapping silicon and / or metals and / or phosphorus and / or halogenates.

[0153] The adsorbent may be operated in regenerative or non-regenerative mode, at a temperature below 400°C, preferably below 100°C, more preferably below 60°C, for example chosen from: (i) a silica gel, (ii) a clay, (iii) a crushed clay, (iv) apatite, (v) hydroxyapatite and combinations thereof, (vi) an alumina, for example an alumina obtained by boehmite precipitation, a calcined alumina such as Ceralox ® from Sasol, (vii) boehmite, (viii) bayerite, (ix) hydrotalcite, (x) a spinel such as Pural ® or Puralox from Sasol, (xi) a promoted alumina, for example Selexsorb ® from BASF, an acid promoted alumina, an alumina promoted by a zeolite and / or by a metal such as Ni, Co, Mo or a combination of at least two of them, (xii) an acid-treated clay such as Tonsil ® from Clariant,(xiii) a molecular sieve in the form of an aluminosilicate containing an alkali or alkaline-earth cation, for example sieves 3A, 4A, 5A, 13X, for example marketed under the brand Siliporite ® from Ceca, (xiv) a zeolite, (xv) an activated carbon, or the combination of at least two adsorbents, the adsorbent or the at least two adsorbents retaining at least 20% by weight, preferably at least 50% by weight of at least one element among F, Cl, Br, I, O, N, S, Se, Si, P, As, Fe, Ca, Na, K, Mg and Hg and / or water.

[0154] According to a preferred embodiment, the adsorbent is regenerable, has a specific surface area of ​​at least 200 m2 / g and is operated, for example in a fixed bed reactor, at a temperature below 100°C and / or a WH of 0.1 to 10 h 1 and / or at a pressure of 1 to 90 bar in the presence of H2 or in the absence of H2.

[0155] Step (iii) of purification on adsorbent can be carried out continuously or in batch, in one or more reactors, such as fixed bed reactors, fluidized bed reactors or any other type of reactor or suitable device.

[0156] Step (c) may comprise one or more of steps (i) to (iii) depending on the desired purification objective. In preferred embodiments, step (c) may comprise: - at least one washing step (i), optionally followed by at least one purification step (iii) on an adsorbent, - at least one step (iii) of purification by absorbent, - at least one distillation step (ii), optionally followed by at least one step (iii) of purification on an adsorbent.

[0157] The sequence of steps (b) and (c) can make it possible to eliminate at least 20% m of the silicon content, or even at least 30% by mass of silicon, in particular without having to heat the composition to be treated or at a moderate temperature. It will be possible to repeat steps (b) and (c) in order to further reduce the silicon content, and possibly also other heteroatoms.

[0158] Detailed description of the optional catalytic hydrotreatment step (d)

[0159] The hydrotreatment of step (d) can be carried out in a single step or in two steps. When carried out in a single step, the purified composition resulting from step (c) is hydrotreated at a temperature of 200 to 450°C, preferably 200 to 340°C in the presence of hydrogen at an absolute pressure of 20 to 160 bars, preferably 30 to 100 bars and in the presence of at least one hydrotreatment catalyst, for example a catalyst of the NiMo (0.1-60% by mass) and / or CoMo (0.1-60% by mass) type generally on a support.

[0160] Alternatively, the hydrotreatment of step (d) can be carried out in a first step (d-1) in which the purified composition from step (c) is hydrotreated, preferably selectively hydrogenated, at a temperature of 80 to 250°C, preferably 130 to 250°C in the presence of hydrogen at an absolute pressure of 5 to 60 bars, preferably 20 to 50 bars, and in the presence of at least one first hydrotreatment catalyst, preferably a hydrogenation catalyst, for example a hydrogenation catalyst comprising Pd (0.1-10% by weight) and / or Ni (0.1-60% by weight) and / or NiMo (0.1-60% by weight), and in a second step (d-2) in which the effluent from step (d-1) is hydrotreated at a temperature of 200 to 450°C, preferably from 250 to 340°C in the presence of hydrogen at an absolute pressure of 20 to 160 bars, preferably from 30 to 100 bars and in the presence of at least one second hydrotreatment catalyst, for example a NiMo type catalyst (0.1-60% by weight) and / or CoMo (0.1-60% by weight).

[0161] When carried out in two stages, the first hydrotreatment stage can hydrogenate dienes, and in particular conjugated dienes, and acetylenic bonds. The decrease in diene value observed between the inlet and outlet of the first hydrotreatment stage is typically at least 10%, preferably at least 25%, measured according to UOP 326. During the second stage, a known catalyst can advantageously be used to hydrogenate olefins and convert sulfur and nitrogen components into H2S and NH3 respectively.

[0162] During the first step, the composition may pass through one or more catalytic beds, preferably with an overall increase in temperature of at most 150°C, preferably at most 100°C, and / or an increase in temperature of at most 100°C, preferably at most 50°C for each catalytic bed. Advantageously, an intermediate quench may be provided between the catalytic beds, preferably carried out with H2 or with the hydrotreated composition recovered in step (d). This first step can be carried out in a fixed bed reactor, preferably in the presence of at least one catalyst, typically a hydrogenation catalyst. This may be a catalyst comprising at least one metal from groups 8-10, preferably chosen from the group Pt, Pd, Ni and / or their mixture on a support such as alumina, titanium, silica, zirconia, magnesia, carbon and / or their mixtures. For example, a Ni-based catalyst passivated after its reduction will be used, preferably using a di-alkyl-sulfide such as Dimethylsulfide (DMS) or DiEthylSulfide (DES), or thiophene compounds.It may also be a catalyst comprising at least one metal from group 6, such as for example Mo, W, in combination or not with a promoter chosen from at least one metal from groups 8-10, such as for example Ni and / or Co, and / or a mixture thereof, these metals being used in sulphide form and preferably supported on alumina, titanium, zirconia, silica, carbon and / or mixtures thereof.

[0163] During the second step, the composition may pass through one or more catalytic beds, preferably with an overall increase in temperature of at most 100°C, and / or an increase in temperature of at most 50°C on each catalytic bed. Advantageously, an intermediate quench may be provided between the catalytic beds, this quenching preferably being carried out with H2 or with the hydrotreated composition recovered in step d). This second step may be carried out in a fixed bed reactor, preferably in the presence of at least one catalyst, typically a hydrogenation catalyst.It may be a catalyst comprising a hydrogenating function, namely at least one metal from group 6 such as for example Mo, W, in combination or not with a promoter chosen from at least one metal from groups 8-10 such as for example Ni and / or Co, and / or a mixture thereof, these metals preferably being used in sulphide form and supported on alumina, titanium, zirconia, silica, carbon and / or mixtures thereof. The catalyst may also have a trap function and for this purpose have a BET surface area of ​​150 m2 / g to 400 m2 / g.

[0164] Guard reactors may also be provided to remove any chlorine, metals and silicon that may still be present. Thus, a silicon trap may be provided (for example at the inlet of the hydrotreatment stage or at the inlet of the second hydrotreatment stage when there are two stages) which may be in a separate reactor or form the upper bed of a reactor. This trap may operate at a temperature of at least 200°C, and / or at a WH of 1 to 10h-l, and / or at an absolute pressure of 10 to 160 bar in the presence of H2; possibly with a metal trap operating at a temperature of at least 200°C, at a WH of between 1 and 10h-l, at an absolute pressure of 10 to 160 bar in the presence of H2.

[0165] Thus, generally speaking, step (d) can be carried out in a single reactor with several catalytic beds placed in series with possible additions of di-hydrogen between the beds or in several reactors in series depending on the desired objective.

[0166] This hydrotreatment step can also have a demetallation, cracking, dearomatization function depending on the characteristics of the catalyst and the hydrotreatment conditions.

[0167] The feedstock for hydrotreatment, containing at least a portion of the composition purified, can be advantageously heated by a heat exchanger which is fed by the hydrotreatment effluent (since hydrotreatment is exothermic, the hydrotreatment effluent will have a higher temperature than the feed entering the hydrotreatment).

[0168] Preferably, the feedstock for the hydrotreatment, containing at least a portion of the purified composition, may be diluted with a portion of the effluent from the hydrotreatment, still having a higher temperature than the desired temperature at the inlet to the hydrotreatment. This at least partial recycling of the effluent from the hydrotreatment makes it possible to dilute the unsaturates present in the purified composition and to preheat the feedstock.

[0169] At the outlet of the hydrotreatment step, the olefin concentration, measured by the bromine index in the purified composition, is typically at most 5.0, preferably at most 2.0 gBr2 / 100g, preferably at most 1.5 gBr2 / 100g, more preferably at most 0.5 gBr2 / 100g, measured according to the ASTM DI 159 standard. Optional washing step

[0170] The effluent leaving the hydrotreatment step (d), namely the hydrotreated purified composition, can be washed with water to remove inorganic compounds such as hydrosulfide, hydrogen chloride and ammonia before being subjected to further treatments. Use of the purified composition

[0171] The purified composition of step (c), or the hydrotreated purified composition of step (d) optionally washed with water, can be fractionated into usable streams whose cut points are typically chosen according to the subsequent treatment. This fractionation is carried out according to distillation temperature ranges, for example to separate streams of the LPG, gasoline, diesel, heavy fuel oil, kerosene type, which can then be treated in a steam cracker and / or in a catalytic cracker and / or in a hydrocracker (then possibly in a steam cracker) and / or in a hydrotreatment reactor and / or used as such for the preparation of fuels, combustibles, lubricants or base oils. A person skilled in the art knows how to select the most suitable cuts for the subsequent treatment units according to of the desired objective.

[0172] The purified composition of step (c), or the hydrotreated purified composition of step (d) optionally washed with water can also be used diluted, for example mixed with naphtha, diesel or crude oil in order to obtain a concentration of purified plastic liquefaction oil ranging from 0.01% by weight to 50% by weight at the most; preferably from 0.1% by weight to 25% by weight, even more preferably from 1% by weight to 20% by weight at the inlet of the following treatment.

[0173] Detailed description of the optional steam cracking step

[0174] The steam cracking step can be carried out on the purified composition of step (c), or the hydrotreated purified composition of step (d) optionally washed with water, with or without dilution with a conventional steam cracking feedstock. Prior to this steam cracking step, a separation step by distillation can be carried out depending on the technology of the steam cracking furnaces.

[0175] This steam cracking step makes it possible to produce olefins such as ethylene and propylene and aromatics. Ethylene and propylene can then advantageously be converted respectively into polyethylene and polypropylene in a polymerization section.

[0176] The steam cracking step consists of thermally cracking in one or more furnaces a mixture of the purified composition and water vapor at high temperatures of the order of 650 to 1000°C, preferably 700 to 900°C, typically 750 to 850°C, under low pressures (1 to 3 bars). The cracking reaction is carried out in the absence of oxygen. The reaction time is usually very short, of the order of a few hundred milliseconds. These conditions make it possible to break the carbon-carbon bonds and to produce unsaturated hydrocarbons with molecules smaller than the feedstock introduced into the reactor(s). The effluents leaving the reactor(s) are then cooled rapidly to temperatures of 400 to 550°C in order to limit secondary reactions such as the polymerization of olefins, dienes and acetylenes.The cooled effluents are finally fractionated to recover light C2-C5 olefins, such as ethylene, propylene, butadiene, isobutene, n-butene and isoprene.

[0177] The purified composition of step (c), or the hydrotreated purified composition of step (d) optionally washed with water, may be sent to the steam cracker without dilution or may be mixed with naphtha, gas oil or crude oil in order to obtain a concentration of purified plastic liquefaction oil ranging from 0.01% by weight to 50% by weight at the maximum; preferably from 0.1% by weight to 25% by weight, even more preferably from 1% by weight to 20% by weight at the inlet of the steam cracker. The diluted purified composition is then converted into olefins, such as ethylene and propylene, as well as aromatics.

[0178] In a preferred embodiment, the purified composition of step (c), or the The hydrotreated purified composition of step (d) optionally washed with water, may be sent at least partially directly into a steam cracker without any further dilution than the steam used for steam cracking, and preferably as the only stream sent at least partially into the steam cracker, to produce olefins, such as ethylene and propylene, and aromatics.

[0179] The steam cracker is known per se in the art. The feedstock to the steam cracker, in addition to the stream obtained by the inventive process, may be ethane, liquefied petroleum gas, naphtha, or gas oils. Liquefied petroleum gas (LPG) consists essentially of propane and butanes. Gas oils have a boiling range of about 200 to 350°C, and consist of C10 to C22 hydrocarbons, including essentially linear and branched paraffins, cyclic paraffins, and aromatics (including mono-, naphtho-, and polyaromatics).

[0180] In particular, the cracking products obtained at the outlet of the steam cracker may comprise ethylene, propylene and benzene, and optionally hydrogen, toluene, xylenes and 1,3-butadiene.

[0181] In a preferred embodiment, the outlet temperature of the steam cracker may be between 800 and 1200°C, preferably between 820 and 1100°C, more preferably between 830 and 950°C, more preferably between 840 and 920°C. The outlet temperature may influence the content of high-value chemicals in the cracking products obtained by the present process.

[0182] In a preferred embodiment, the residence time in the steam cracker, through the radiation section of the reactor where the temperature is between 650 and 1200°C, may be between 0.005 and 0.5 seconds, preferably between 0.01 and 0.4 seconds.

[0183] In a preferred embodiment, the steam cracking is carried out in the presence of water vapor in a ratio of 0.1 to 1.0 kg of steam per kg of hydrocarbon feedstock, preferably 0.25 to 0.7 kg of steam per kg of hydrocarbon feedstock in the steam cracker, preferably in a ratio of 0.35 kg of steam per kg of feedstock mixture, to obtain cracking products as defined above.

[0184] In a preferred embodiment, the reactor outlet pressure may be between 500 and 1500 mbar, preferably between 700 and 1000 mbar, more preferably may be about 850 mbar. The residence time of the feedstock in the reactor and the temperature must be considered together. A lower operating pressure helps to facilitate the formation of light olefins and to reduce coke formation. The lowest possible pressure is achieved by (i) keeping the reactor outlet pressure as close as possible to atmospheric pressure at the cracking gas compressor suction (ii) reducing the pressure hydrocarbons by dilution with steam (which has a substantial influence on slowing down coke formation). The steam / raw material ratio can be maintained at a level sufficient to limit coke formation.

[0185] Since the purified composition has a broad distribution in terms of carbon numbers (or boiling points), the vaporization of such a feedstock may be incomplete at the inlet of the reactors at the temperature where certain hydrocarbon molecules begin to decompose. The purified composition may then be preheated to a temperature at least 10°C below the decomposition temperature, and then subjected to separation of the produced hydrocarbon vapors and the residual hydrocarbon liquid in a flash vessel. In this flash vessel, the liquid exits from the bottom by gravity and the hydrocarbon vapors from the top. Optionally, the hydrocarbon liquid may be returned to the plastics liquefaction unit or to the optional hydrocracking step.

[0186] Detailed description of the optional hydrocracking step

[0187] Prior to the steam cracking step, the purified composition of step (c), or the hydrotreated purified composition of step (d) optionally washed with water, may be subjected to a cracking reaction in order to reduce the length of the carbon chains of the paraffins present.

[0188] Typically, this cracking reaction is a hydrocracking reaction carried out at a temperature of 250 to 480°C, a hydrogen partial pressure of 1.5 to 25 MPa abs. and an hourly volumetric flow rate of 0.1 to 10 h *.

[0189] A usable hydrocracking catalyst comprises, for example, a support chosen from halogenated aluminas, combinations of boron and aluminum oxides, amorphous silica-aluminas and zeolites and a hydro-dehydrogenating function comprising at least one metal from group 6 chosen from chromium, molybdenum and tungsten, alone or as a mixture, and / or at least one metal from groups 8-10 chosen from iron, cobalt, nickel, ruthenium, rhodium, palladium and platinum.

[0190] In one embodiment, the hydrocracking step may be performed by adding a bed of hydrocracking catalyst downstream of the last hydroprocessing catalyst bed of the hydroprocessing section. Description of figures

[0191] [Fig-1] [Fig.l] describes a possible embodiment of the invention. In this embodiment of possible embodiment, The plastic liquefaction oil composition (1) is first optionally pretreated in a pretreatment section (A) to be subjected therein to a pretreatment (PTT) by (i) filtration, (ii) washing with water or a polar solvent, (iii) distillation, (iv) decantation, or (v) the combination of two, three or four of steps (i) to (iv). The pretreated composition (2) is then sent to a treatment section (B) for carrying out the salt treatment step (TTsalt) in accordance with step (b) of the invention. The effluent (3) leaving this treatment section (B) can then be sent to a solids separation section (SI), or else be sent directly to a purification section (C) to carry out step (c) TTPur, for example step (c) (i) of the invention. Section (C) can comprise a washing section, a distillation section or a purification section by passage over adsorbent, or several of these sections to carry out one or more of steps (i) to (iii) as described with reference to the method.The effluent (5), leaving the TTpur stage, can then be sent to a second optional section (S2) for separating the solids, or else be sent directly to an optional hydrotreatment section (D) for the implementation of an HDT hydrotreatment stage corresponding to stage (d) of the invention.

[0192] The effluent (7) leaving the hydrotreatment section (D), optionally after fractionation and / or dilution, can be sent to one or more of the following optional sections: an optional hydrotreatment section (S-HDT), an optional treatment section (S-VAPO) in a steam cracker, an optional treatment section (S-HC) in a hydrocracker, an optional treatment section (S-FCC) in a fluidized bed catalytic cracker, an optional preparation section (S-Pool) of a fuel or a combustible or a lubricant or a base oil. Preferably, the effluent (7) leaving the hydrotreatment section (D) is then steam cracked to obtain olefins which can then be polymerized. Preferably, the effluent (7) leaving the hydrocracking section (S-HC) is then steam cracked to obtain olefins which can then be polymerized. Examples Example 1

[0193] A test of contacting a plastic pyrolysis oil HPP1 with TBAF (CAS 429-41-4) followed by washing with water was carried out (TEST 1).

[0194] For this purpose, the HPP1 oil was brought into contact with a solution of TBAF in THF for 24 hours at room temperature and atmospheric pressure, then washed three times with water, the mixture / water mass ratio being 60 / 40. The ratio of the number of moles of TBAF used to the number of moles of silicon in the HPP1 oil is 9.2.

[0195] A comparative test (Comparative 1) consisted of subjecting the same HPP1 oil to a simple wash with water, the mixture / water mass ratio being 50 / 50.

[0196] Each oil sample is analyzed to measure its heteroatom content (chlorine, silicon, nitrogen, oxygen). Knowing the initial concentration of impurities in the HPP1 oil, the reductions in each of the elements mentioned were calculated. results are collected in Table 1.

[0197] [Tables] Element Silicon Chlorine Nitrogen Oxygen Content (ppm) Abatement Content (ppm) Abatement Content (ppm) Abatement Content (% m) Abatement HPP1 95 466 1701 1.49 Comp. 1 — — 440 6% 961 44% 1.21 19% TEST 1 62 35% 434 7% 749 56% 1.19 20%

[0198] The reductions in oxygen, chlorine and nitrogen obtained for TEST 1 are similar to those obtained following washing with water. On the other hand, while washing with water does not remove silicon, the treatment of TEST 1 allows a reduction of 35% to be obtained. Example 2

[0199] Another HPP2 plastic pyrolysis oil was contacted with TB AF dissolved in THF for 5 hours at 60°C (TEST 2), at atmospheric pressure. The maximum temperature used is lower than the boiling point of THF (66°C). The ratio of the number of moles of TB AF used to the number of moles of silicon in the HPP2 oil is approximately 8.

[0200] Table 2 summarizes the operating conditions of the test. After bringing the HPP2 oil into contact with the TB AF, the mixture was washed three times with water, the mixture / water mass ratio being 60 / 40.

[0201] At the end of the test, each oil sample is analyzed to measure its heteroatom content (chlorine, silicon, nitrogen, oxygen, fluorine, bromine). Knowing the initial concentration of impurities, the reductions in each of the elements mentioned are then calculated. The results are gathered in Table 3.

[0202] [Tables2] TEST TBAF mass (g) Initial HPP1 mass (g) Temp. (°C) Quantity of oil recovered after the TBAF step Quantity of oil recovered after washing Overall yield Mass (g) % Mass (g) % % TEST 2 2.0 164.4 60 164.5 98.8 156.15 94.9 95.0

[0203] Despite the numerous impurities present in the HPP2 treated oil, an overall yield of approximately 95% could be obtained with the process according to the invention.

[0204] [Tables3] Element Si Cl NOFB Content (ppm) Abatement Content (PPm) Abatement Content (ppm) Abatement Content (% m) Abatement PPm HPP2 44 135 3780 1.62 <5 <5 TEST 2 30 32% 118 13% 2371 37% 1.24 23% - - Example 3

[0205] Another HPP3 plastic pyrolysis oil was contacted with sodium monofluorophosphate Na2PFO3 in solution in water at 225°C for 30 minutes. The ratio chosen is 1% by mass of Na2PFO3 relative to the mass of HPP3 oil treated. The ratio of the number of moles of Na2PFO3 used to the number of Si of the HPP3 oil is approximately 43. After contacting the HPP3 oil with the Na2PFO3, the mixture was washed three times with water, the mass ratio of mixture to water being 60 / 40. Table 4 summarizes the calculated quantities and yields. An overall yield of approximately 94% is obtained.

[0206] At the end of the test (Test 3), the oil sample was analyzed to measure its heteroatom content (chlorine, silicon, nitrogen, oxygen, fluorine, bromine). Knowing the initial concentration of impurities, the reductions in each of the elements mentioned are then calculated. The results are gathered in Table 5. Nearly a quarter of the heteroatoms are eliminated after 30 minutes of treatment with Na2PFO3.

[0207] [Tables4] Charge Water volume Mass Na 2PFO3 Charge mass Quantity of oil recovered after step Na2PFO3 Quantity of oil recovered after washing Overall yield (mL) (g) (g) (g) % (g) % (%) HPP3 15.72 3.98 400.02 396.85 99 376.47 95 94

[0208] [Tables5] Element Si Cl NO Content (ppm) Abatement Content (ppm) Abatement Content (ppm) Abatement Content (% m) Abatement HPP3 44 136 2700 1.37 Test 3 33 25% 103 24% 2014 25% 1.18 14%

Claims

Claims

1. A method of purifying a composition comprising a plastic liquefaction oil comprising the following steps: (a) providing a composition comprising a plastic liquefaction oil, said composition containing at least 20 ppm by mass of heteroatoms including silicon, (b) contacting the composition of step (a) with a salt of a fluorine-containing anion to obtain an effluent containing the modified composition, (c) subjecting the effluent of step (b) to (i) washing in the presence of water or a solvent immiscible with the modified composition, (ii) distillation, (iii) purification by passage over a solid adsorbent, or a combination of two or more of steps (i), (ii), (iii), and recovering a purified composition having a reduced content of silicon and other heteroatoms.

2. A method according to claim 1, characterized in that said composition provided in step (a) comprises at least one of the following features: - said composition contains at least 10% by weight of plastic liquefaction oil, the other part of said composition being a diluent or said composition contains only plastic liquefaction oil, - said plastic liquefaction oil in said composition has an initial boiling point of at least 15°C and a final boiling point of at most 700°C,, - said plastic liquefaction oil contains more than 2 ppm by weight of metals, - said plastic liquefaction oil contains at least 1 ppm by weight of Si relative to the total weight of said plastic liquefaction oil, - said plastic liquefaction oil contains at least 1 ppm by weight of Cl,, and / or at least 1 ppm by weight of P, relative to the total weight of said plastic liquefaction oil plastic.

3. Method according to claim 1 or 2, characterized in that step (b) comprises one or more of the following characteristics: - prior to step (b), the first effluent is subjected to (i) filtration, (ii) washing with water or an immiscible polar solvent with the composition, (iii) distillation, (iv) decantation, or (v) the combination of two, three or four of steps (i) to (iv), - prior to step (b) or during step (b), there is added to the composition (i) said salt in solid form, (ii) said salt previously solubilized in an aqueous medium or (iii) said salt previously solubilized in an organic solvent, - the ratio of the number of moles of said salt to the number of moles of silicon present in the composition is from 3:1 to 1000:1, - said salt comprises an anion chosen from a fluoride ion and a fluorophosphate ion, and a cation chosen from an alkali metal cation, the ammonium ion and a quaternary ammonium cation, - said salt is chosen from cesium fluoride CsF, sodium fluoride NaF, potassium fluoride KF, sodium monofluorophosphate Na2PFO3, tetra-n-butylammonium fluoride, tetramethylammonium fluoride, tetraethylammonium fluoride,tetrapropylammonium fluoride, ammonium fluoride, and mixtures thereof, - step b) is carried out at a temperature below 250°C, - step b) is carried out for a period of 15 minutes to 72 hours.,

4. Method according to any one of claims 1 to 3, characterized in that step (c) comprises at least one of the following characteristics: - step (c) is preceded or followed by a step of separation of the solids by (i) filtration, (ii) centrifugation, (iii) hydrocyclone or (iv) a combination of two or more of these steps, - step (c) (i) of washing is carried out in the presence of water at neutral, basic or acidic pH, or in the presence of an organic solvent immiscible with the composition, - step (c) (iii) of purification is carried out by passage over a solid adsorbent in order to reduce the content of at least one element among F, Cl, Br, I, O, N, S, Se, Si, P, As, Fe, Ca, Na, K, Mg and Hg and / or the water content.

5. A process according to any one of claims 1 to 4, wherein: (d) the purified composition of step (c) undergoes a one or two-step catalytic hydrotreatment to provide a hydrotreated purified composition.

6. Process according to claim 5, characterized in that the hydrotreatment of step (d): - is carried out in a single step in which the purified composition of step (c) is hydrotreated at a temperature of 200 to 450°C, preferably 200 to 340°C in the presence of hydrogen at an absolute pressure of 20 to 160 bars, preferably 30 to 100 bars and in the presence of at least one hydrotreatment catalyst, or - is carried out in a first step (d-1) in which the purified composition of step (c) is hydrotreated at a temperature of 80 to 250°C, preferably 130 to 250°C in the presence of hydrogen at an absolute pressure of 5 to 60 bars, preferably 20 to 50 bars and in the presence of at least one first hydrotreatment catalyst, and in a second step (d-2) in which the effluent from step (d-1) is hydrotreated at a temperature of 200 to 450°C, preferably 250 to 340°C in the presence of hydrogen at an absolute pressure of 20 to 160 bars, preferably 30 to 100 bars and in the presence of at least one second hydrotreatment catalyst.

7. A process according to any one of claims 1 to 6, wherein the hydrotreated purified composition leaving step (d) is washed with water to remove inorganic compounds such as hydrosulfide, hydrogen chloride, ammonia.

8. A process according to any one of claims 1 to 7, wherein the purified composition of step (c), or the hydrotreated purified composition of step (d) optionally washed with water, is used as such or separated into streams usable for the preparation of fuels and combustibles such as LPG, gasoline, diesel, heavy fuel oil, kerosene and / or for the preparation of lubricants and / or base oils.

9. A process according to any one of claims 1 to 7, wherein the purified composition of step (c), or the hydrotreated purified composition of step (d), is subjected, neat or diluted, optionally after separation into usable streams, to a steam cracking step to produce olefins such as ethylene and propylene, which can then be used to manufacture new polymers by polymerization.

10. A process according to any one of claims 1 to 7, wherein the purified composition of step (c), or the hydrotreated purified composition of step (d), is treated, pure or diluted, optionally after separation into usable streams, in a steam cracker to produce olefins, and / or a fluidized bed catalytic cracker, and / or a hydrocracker, then optionally in a steam cracker, and / or a hydrotreatment reactor, in particular a catalytic hydrogenation reactor. talytic.

11. A method according to any one of the preceding claims wherein step a) comprises the preliminary step a1) of providing a plastic waste stream; a2) liquefying said plastic waste stream by pyrolysis or hydrothermal liquefaction at a temperature of at least 200°C; a3) recovering a liquefaction effluent and separating said liquefaction effluent into a C1 to C4 hydrocarbon fraction and a remaining fraction forming said plastic liquefaction oil; a4) optionally mixing said remaining fraction with a solvent or diluent.

Images