Process for purifying a plastic liquefaction oil composition

Abstract

The invention relates to a method for purifying a composition comprising a plastic liquefaction oil, wherein: (a) a plastic liquefaction oil composition is supplied, then (b) washed with a first aqueous solution to obtain an organic phase containing the washed composition and a first aqueous effluent, then (c) the organic phase from step (b) is treated in the presence of a basic compound at a temperature of not more than 450°C to obtain an organic effluent comprising a treated composition, and (d) the organic effluent from step (c) is washed with a second aqueous solution to obtain a purified composition having a reduced heteroatom content, and a second aqueous effluent. Furthermore, in step (b), the first aqueous effluent is returned in whole or in part to step (d), and / or in step (d), the second aqueous effluent is returned in whole or in part to step (b). Abstract figure: Fig. 1

Description

Title of the invention: Process for purifying a plastic liquefaction oil composition Technical field of the invention

[0001] The present invention relates to a process for purifying a composition comprising a plastic liquefaction oil and its subsequent use in refining and petrochemical processes. The process according to the invention makes it possible, in particular, to reduce the concentration of heteroatoms in feedstocks from plastic waste, notably for their use in a steam cracking process. Technological background

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

[0003] One possible method for recycling plastic is plastic liquefaction by pyrolysis or hydrothermal liquefaction. However, the resulting plastic oil generally contains large quantities of heteroatoms, including metals, and dienes. Many heteroatoms, including metals, are contaminants for the catalysts in the hydrotreating processes commonly used to recycle plastics. Furthermore, dienes readily react to form gums. Dienes are also precursors to coke in a steam cracker. Therefore, it is necessary to pretreat plastic liquefaction oils before they can be recycled.

[0004] There are many treatment processes that allow the heteroatom content of plastic liquefaction oils to be reduced.

[0005] Patent JP3776335 discloses a process for dechlorinating and deazotizing an oil obtained from the catalytic or thermal cracking of plastic waste which is treated at various temperatures up to 425°C for 30 minutes in the presence of an aqueous solution of an alkali or alkaline earth metal compound at a pH greater than or equal to 7. The reaction product is then separated from the alkaline aqueous solution by liquid-liquid separation with ethyl ether.

[0006] Patent application WO2012 / 069467 claims a process 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 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. Following the reaction, the pyrolysis oil is separated from the alkaline aqueous phase. A final hydrotreatment yields a steam cracker feedstock, which is optionally washed with an acidic solution before being introduced into the steam cracker.

[0008] Patent application WO2020 / 020769 claims a process sequence for purifying a composition containing 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 feed in the presence of an alkali metal hydroxide to achieve a reduction of at least 50% in the chlorine content relative to the feed, followed by hydrotreatment to achieve a further reduction of at least 50% in the chlorine content.

[0009] Patent application WO2021 / 105326 claims a process for valorizing liquefied plastic waste comprising a pretreatment step of 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 includes the use of a NaOH solution in water. The separation of the aqueous and organic phases is carried out by physical methods (centrifugation) or chemical methods (addition of separation aids, for example, non-aqueous solvents, addition of an additional quantity of the aqueous medium used for contacting or of an aqueous medium having a different alkaline concentration), or by gravity.

[0010] Most existing purification treatments are carried out at relatively high temperatures. Furthermore, these treatments do not provide a means of reducing the silicon content, or the alkali / alkaline earth metal content, present in the plastic pyrolysis oil after pretreatment with a base. It is known that the presence of alkali / alkaline earth metals can lead to the deactivation of catalysts used in catalytic recycling processes for purified plastic liquefaction oil. In addition, known purification processes use high quantities of reagents and / or water.

[0011] There is therefore a need to improve existing purification processes. Summary of the invention

[0012] The invention aims to provide a process for purifying plastic liquefaction oil that facilitates its purification and reduces the quantities of reagents and water used, while maintaining high removal performance in heteroatoms, in particular silicon, including for the removal of the content of alkali and / or alkaline earth metals resulting from the treatment of plastic liquefaction oil by a basic compound containing for example an alkali or alkaline earth metal.

[0013] To this end, the invention relates to a method for purifying a composition comprising a plastic liquefaction oil, comprising the following steps:

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

[0015] (b) wash the composition provided in step (a) with a first aqueous solution to obtain an organic phase containing the washed composition and a first aqueous effluent containing the first aqueous solution and at least some of the heteroatoms initially contained in the composition,

[0016] (c) treat the organic phase of step (b) in the presence of a basic compound at a temperature of no more than 450°C to obtain an organic effluent comprising a treated composition

[0017] (d) wash the organic effluent from step (c) with a second aqueous solution and to obtain a purified composition with a reduced heteroatom content, and a second aqueous effluent containing the second aqueous solution, the basic compound and at least some of the heteroatoms initially contained in the treated composition,

[0018] the method further comprising at least one of the following characteristics:

[0019] - during step (b), the first aqueous effluent is returned in whole or in part in step (d) and added to the second aqueous solution,

[0020] - during step (d), the second aqueous effluent is returned in whole or in part in step (b) and added to the first aqueous solution.

[0021] The first washing step (b) makes it possible in particular to reduce the content of the composition in oxygenated compounds and also to limit the amount of solids formed during the step (c), while the second washing step (d) will make it possible to eliminate impurities containing heteroatoms, in particular alkali metals, alkaline earth metals, silicon, chlorine, bromine, iron, aluminum and others, as well as the basic compound used during the treatment step (c).

[0022] Surprisingly, the use of the first aqueous effluent and / or the second aqueous effluent in steps (d) and (b) respectively improves the treatment of the composition while limiting both the amount of water used and the amount of basic compound used. In particular, the process according to the invention It allows for the removal of 65 to 98% of one or more heteroatoms present in the composition. In particular, the process according to the invention makes it possible to obtain a purified composition having a silicon content of less than 2 ppm, and / or a metal content, particularly of alkaline earth metals, of less than 2 ppm.

[0023] This advantage is particularly observed when the first aqueous effluent is returned in whole or in part to step (d) and the second aqueous effluent is returned in whole or in part to step (b). The first and second aqueous effluents can then circulate in a circuit linking the two washing sections implementing the two washing steps, optionally with the possibility of injecting fresh water into this circuit and / or extracting part of the aqueous phase circulating in the circuit.

[0024] Thus, in one embodiment, the first aqueous effluent and the second aqueous effluent circulate in a circuit connecting a first washing section implementing washing step (b) to a second washing section implementing washing step (d). In order to maintain a constant water flow rate in this circuit, water can be replenished by regularly injecting water into the circuit, advantageously upstream of the second washing section. Furthermore, a portion of the fluid circulating in the circuit, preferably a portion of the first aqueous effluent, can be withdrawn upstream of the water injection point.

[0025] Thus, advantageously, water is injected into the circuit, optionally upstream of the second washing section, and optionally a portion of the fluid circulating in the circuit is withdrawn.

[0026] Advantageously, before entering step (c), the organic phase of step (b) can be preheated in a heat exchanger by the second effluent from step (c).

[0027] Step (c) according to the invention may include one or more of the following features: - Step (c) is carried out in the presence of 0.1 to 50% w of basic compound relative to the total mass of the treated organic phase, - prior to step c) or during step c), the following are added to the organic phase of step b): (i) a solid basic compound, (ii) a basic compound previously dissolved in an aqueous medium, preferably water, or (iii) a basic compound previously dissolved in a solvent, - the basic compound comprises an oxide, hydroxide, bicarbonate or alkoxide of an alkali metal cation or an alkaline earth metal cation, or a hydroxide or bicarbonate of a quaternary ammonium cation, alone or in mixture, - The basic compound can be chosen from LiOH, NaOH, CsOH, Ba(OH)2, Na2 O, KOH, K20, CaO, Ca(OH)2, MgO, Mg(OH)2, NH4OH, TBuOH, TEAOH, TMAOH, EtONa, MeONaand their mixtures, - step c) is carried out at a temperature of 50 to 450°C, preferably 50 to 350°C, more preferably 50 to 250°C, even more preferably 50 to 225°C or 50 to 200°C, or even 90°C to 200°C or 150 to 200°C or within any range defined by any two of these limits, - step c) is carried out for a duration of 0.1 seconds to 3 hours, preferably from 0.1 seconds to 2 hours, more preferably from 1 minute to 1 hour, even more preferably from 1 minute to 20 minutes or from 1 minute to 16 minutes.

[0028] Step (c) according to the invention may be followed by a separation step in which the basic compound is separated from the effluent and returned, in whole or in part, upstream of step (c), advantageously at the inlet of step (c), the separation step being carried out by (i) filtration, (ii) centrifugation, (iii) hydrocyclone, (iv) sedimentation, or (v) a combination of two or more of these steps

[0029] Step (d) according to the invention may be followed by a solids separation step by (i) filtration, (ii) centrifugation, (iii) hydrocyclone or (iv) a combination of two or more of these steps,

[0030] Advantageously, prior to processing in step (b), said composition may be subjected to (i) filtration, (ii) distillation, (iii) decantation, or (iv) a combination of two or three of steps (i) to (iii).

[0031] Advantageously, (e) the purified composition of step (d), pure or diluted, can undergo catalytic hydrotreatment, namely catalytic treatment under hydrogen, in one or two steps to provide a purified hydrotreated composition.

[0032] The hydrotreatment of step (e): - can be carried out in a single step in which the purified composition of step (d) is hydrotreated at a temperature of 200 to 450°C, preferably 200 to 380°C in the presence of hydrogen at an absolute pressure of 20 to 140 bar, preferably 30 to 100 bar and in the presence of a hydrotreating catalyst, or - can be carried out in a first step (e-1) in which the purified composition from step (d) 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 150 bar, preferably 20 to 100 bar, and in the presence of a first hydrotreating catalyst, and in a second step (e-2) in which the effluent from step (e-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 150 bar, preferably 30 to 100 bar, and in the presence of a second catalyst hydrotreatment.

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

[0034] Advantageously, the purified composition of step (d) or the hydrotreated purified composition of step (e) may be:

[0035] (f) used as is or separated into usable streams for the preparation of fuels and combustibles such as LPG, petrol, diesel, heavy fuel oil, kerosene and / or for the preparation of lubricants and / or base oils,

[0036] and / or treated, pure or diluted, optionally separated into usable streams, in:

[0037] (g) a steam cracker to produce olefins, and / or

[0038] (h) a fluidized bed catalytic cracker, and / or

[0039] (i) a hydrocracker, then optionally in a steam cracker.

[0040] Preferably, the purified composition of step (d) or the hydrotreated purified composition of step (e) can be subjected, pure or diluted, optionally after separation into usable streams, to a steam cracking step (g) to produce olefins such as ethylene and propylene as well as aromatics such as toluene, xylene and benzene, which can then be used to manufacture new polymers by polymerization.

[0041] The previously described steps of the process according to the invention can be carried out one after the other without intermediate steps except for the optional additional steps described.

[0042] The invention also relates to an installation comprising an optional pretreatment section (A), a first washing section (B), a treatment section (C), an optional separation section (S), a second washing section (D), an optional hydrotreating section (E) and / or an optional fuel or lubricant or base oil preparation section (F) and / or an optional steam cracker treatment section (G) and / or an optional fluidized bed catalytic cracker treatment section (H) and / or an optional hydrocracker treatment section (I), wherein the various sections are fluidly connected to implement the process according to the invention. Definitions

[0043] The Hourly Volumetric Velocity (WH) is defined as the hourly volume of charge flux per unit catalytic volume and is expressed here in h*.

[0044] The terms "including" and "includes" as used herein are synonymous with "including", "includes" or "contains", "containing", and are inclusive or boundless and do not exclude additional features, elements or unspecified method steps.

[0045] The specification of a decimal-free numeric domain includes all integers and, where appropriate, fractions thereof (for example, 1 to 5 may include 1, 2, 3, 4 and 5 when reference is made to a number of elements, and may also include 1.5, 2, 2.75 and 3.80, when reference is made to, for example, a measure.).

[0046] The specification of a decimal also includes the decimal itself (for example, "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.

[0047] The expressions % by weight and % by mass have equivalent meanings and refer to the proportion of the mass in grams of a product relative to 100g of a composition comprising it.

[0048] Unless otherwise indicated, measurements given in parts per million (ppm) are expressed by weight.

[0049] By "heteroatom" is meant any element of an organic compound other than carbon and hydrogen.

[0050] The term "naphtha" refers to the general definition used in the oil and gas industry. In particular, it is a hydrocarbon obtained 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. Naphtha is generally considered to have a carbon number between C5 and Cl1, although the carbon number can in some cases reach Cl5. It is also generally accepted that the density of naphtha is between 0.65 and 0.77 g / mL.

[0051] The term "liquefaction oil" means an oil obtained from a pyrolysis process and / or a hydrothermal liquefaction process of a hydrocarbon feedstock. This hydrocarbon feedstock may include plastics, biomass, and / or elastomers, alone or in mixtures, including waste materials. A liquefaction oil may be formed from a mixture of two or more liquefaction oils obtained from the liquefaction of different hydrocarbon feedstocks.

[0052] The pyrolysis process should be understood as a thermal cracking process, typically carried out at a temperature of 300 to 1000°C or 400 to 700°C, implemented in the presence or without a catalyst and / or a gas (rapid pyrolysis, flash pyrolysis, catalytic pyrolysis, hydropyrolysis, steampyrolysis,....).

[0053] The hydrothermal liquefaction (or HTL) process is a thermochemical conversion process using water as a solvent, reactant, and catalyst for the degradation reactions of a hydrocarbon feedstock, with the 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.

[0054] The expression "plastic liquefaction oil" or "oil resulting from the liquefaction of plastic" or "plastic waste liquefaction oil" or "liquefaction oil resulting from the liquefaction of waste containing plastics" refers to hydrocarbon liquid products obtained from pyrolysis or hydrothermal liquefaction of thermoplastic and / or thermosetting polymers, alone or in mixture, and generally in the form of waste, optionally in mixture with at least one other feedstock, in particular in the form of waste, such as biomass, for example selected from ligno-cellulosic biomass, paper and cardboard, and / or an elastomer, for example latex possibly vulcanized or tires.

[0055] 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 be materials made up of polymers and optionally of 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), polylactic acid (PLA), 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.In general, any polymer or mixture of polymers capable of producing hydrocarbons by liquefaction can be used.

[0056] Biomass can be defined as an organic product of plant or animal origin. Biomass thus includes (i) biomass produced from surplus agricultural land not used for human or animal consumption: dedicated crops, known as 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) forestry residues from silviculture 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 can be derived from the liquefaction of waste containing at least 1% w / w, optionally from 1 to 50% w / w, from 2 to 30% w / w or within a range defined by any two of these limits, from one or more of the aforementioned biomasses, residues and organic waste, and the remainder being made up of plastic waste, optionally mixed with elastomers. particularly in the form of waste.

[0057] Elastomers are linear or branched polymers transformed by vulcanization into a weakly cross-linked, 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, mixed or not 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, acrylonitrile butadiene copolymers (NBR), and polychlorinated polypropylenes (CR), polyurethanes, silicone elastomers, etc.The plastic liquefaction oil treated by the invention can be derived from the liquefaction of waste containing at least 1% w / w, optionally from 1 to 50% w / w, from 2 to 30% w / w or within 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.

[0058] The expression “MAV” (acronym for “Maleic Anhydric Value”) refers to the UOP326-82 method which is expressed in mg of maleic anhydride that react with 1 g of sample to be measured.

[0059] The expression "Number of bromine" corresponds to the quantity of bromine in grams that has reacted on 100 g of sample and can be measured according to the ASTM DI 159-07 method.

[0060] The term "Bramine Index" is the number of milligrams of bromine that react with 100 g of sample and can be measured according to ASTM D2710 or ASTM D5776 methods.

[0061] Boiling points as mentioned herein are measured at atmospheric pressure, unless otherwise specified. An initial boiling point is defined as the temperature at which the first vapor bubble forms. A final boiling point is the highest temperature attainable during distillation. At this temperature, no more vapor can be transported to a condenser. The determination of the initial and final boiling 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 measuring the boiling points of petroleum fractions by gas chromatography, ASTM D7169 for heavy hydrocarbons, ASTM D7500, D86 or DI 160 for distillers.

[0062] The concentration of metals in hydrocarbon matrices can be determined by any known method. Acceptable methods include X-ray fluorescence (XRF), inductively coupled plasma mass spectrometry (ICP-MS), and inductively coupled plasma atomic emission spectrometry (ICP-AES). Analytical scientists can identify the most suitable method for measuring each metal and, more generally, each heteroatom, depending on the hydrocarbon matrix under consideration. Oxygen content can be measured according to ASTM D5622-17 / D2504-88 (2015). Nitrogen content can be measured according to ASTM D4629-17. Sulfur content can be measured according to ISO 20846:2011. Halogen content, including chlorine, bromine, and fluorine, can be measured according to ASTM D7359-18.

[0063] The term “hydrotreating” refers to any process in which hydrocarbons react with dihydrogen, typically under pressure, with or without a catalyst. Hydrotreating may thus include one or more reactions selected from hydrodesulfurization (HDS), hydrodeazotation (HDN), hydrodeoxygenation (HDO), hydrodemetallation (HCM), hydrocracking, hydroisomerization, and hydrogenation (hydrogenation of unsaturated compounds into saturated compounds).

[0064] By "hydrotreating catalyst" is meant a catalyst that promotes the incorporation of hydrogen into the products. This type of catalyst is typically a metallic 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.

[0065] The particular features, structures, properties, embodiments of the invention can be freely combined into one or more embodiments not specifically described here, as may be apparent to specialists in the processing of plastic liquefaction oils implementing their general knowledge. Detailed description of the invention

[0066] Description of the composition comprising a plastic liquefaction oil

[0067] The composition provided in step (a) comprises a plastic liquefaction oil. This plastic liquefaction oil may be a plastic pyrolysis oil, a plastic hydrothermal liquefaction oil, or a mixture of both.

[0068] In a preferred embodiment, the composition may comprise only a plastic liquefaction oil.

[0069] Alternatively, the composition treated by the process according to the invention may comprise at least 1% by mass, or even at least 2% by mass of oil(s) of plastic content. The remainder may then be composed of at most 99% by mass, respectively at most 98% by mass, of a diluent or solvent such as a hydrocarbon and / or of one or more components listed below.

[0070] In one embodiment, the composition may comprise at least 5% by mass, preferably 10% by mass, more preferably at least 25% by mass, even more preferably at least 50% by mass, more preferably 75% by mass, and even more preferably at least 90% by mass of plastic liquefaction oil. The composition may comprise at most 80% by mass, 90% by mass, 95% by mass, or 100% by mass of plastic liquefaction oil. The mass content of plastic liquefaction oil(s) in the composition may fall within any range defined by two of the aforementioned limits.

[0071] The composition may include one or more of the following components: tall oil, used cooking oil, animal fat, vegetable oil such as rapeseed, canola, castor, palm, soybean oil, oil extracted from an alga, oil extracted from the fermentation of oil-bearing 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 liquefying ground-up used furniture, elastomer liquefaction oil, for example latex possibly vulcanized or tires, as well as mixtures thereof.

[0072] The composition may have a bromine content of at most 150 g Br2 / 100g, preferably at most 100 g Br2 / 100g, even more preferably at most 80 g Br2 / 100g, the most preferred being at most 50 g Br2 / 100g, as measured according to ASTM D1159.

[0073] The composition may have a heteroatom content of at least 20 ppm.

[0074] The other component may include any diluent miscible with the plastic liquefaction oil. This diluent preferably has a diene number of not more than 0.5 g I₂ / 100 g, measured according to UOP 326-17, and a bromine number of not more than 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 direct-distillation diesel or gas oil, containing not more than 1 wt% of sulfur, preferably not more than 0.1 wt% of sulfur, and / or a hydrocarbon stream having a boiling range between 50°C and 150°C or between 150°C and 250°C or between 200°C and 350°C, preferably having a bromine number of not more than 5 g Br₂ / 100 g, and / or a diene number of not more than 0.5 gI2 / 100g or any combination thereof.

[0075] Step (a) of supplying the composition may include:

[0076] (al) a step of liquefying waste containing plastics and obtaining a hydrocarbon product comprising a gaseous phase, a liquid phase and a solid phase, (a2) a step of separating the liquid phase of said product, said liquid phase forming a plastic liquefaction oil,

[0077] (a3) ​​an optional step of mixing the plastic liquefaction oil with a thinner or solvent.

[0078] The liquefaction step (al) may include 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.

[0079] Alternatively or in combination, the liquefaction step (al) may include a hydrothermal liquefaction step, typically carried out at a temperature of 250 to 500 °C and at pressures of 10 to 25-40 MPa.

[0080] The waste treated in step (al) may be plastic waste possibly mixed with biomass, as previously described.

[0081] The separation step (a2) allows the gaseous phase, essentially C1-C4 hydrocarbons and the solid phase (typically char) to be removed in order to recover only the liquid organic phase forming a liquefaction oil.

[0082] A plastic liquefaction oil typically comprises 30 to 80 w / w paraffins (including cycloparaffins), 10 to 95 w / w unsaturated compounds (including olefins, dienes, and acetylenes), and 5 to 70 w / w aromatics. These contents can be determined by gas chromatography.

[0083] In particular, a plastic liquefaction oil may comprise a Bromine number of 10 to 130 g Br / lOOg, as measured according to ASTM DI 159, and / or a maleic anhydride number (UOP326-82) of 1 to 55 mg maleic anhydride / lg.

[0084] A plastic liquefaction oil typically comprises at least 20 ppm of heteroatoms, or even at least 30 ppm of heteroatoms,

[0085] A plastic liquefaction oil may in particular comprise one or more of the following heteroatom contents: 0 to 8% w / w of oxygen (measured according to ASTM D5622), 1 to 13000 ppm of nitrogen (measured according to ASTM D4629), 2 to 1000 ppm of sulfur (measured according to ISO 20846), 1 to 1000 ppm of metals (measured by ICP), 50 to 0000 ppm of chlorine (measured according to ASTM D7359-18), 0 to 200 ppm of bromine (measured according to ASTM D7359-18), 1 to 40 ppm of fluorine (measured according to ASTM D7359-18), 1 to 2000 ppm of silicon (measured by XRF).

[0086] Detailed description of the optional pre-treatment step of the composition

[0087] Prior to the washing step (b), generally between steps (a) and (b), The invention may also include an optional pretreatment step in which the composition is subjected, in particular immediately before step (b), to (i) filtration, (ii) distillation, (iii) decantation, or (iv) a combination of two or three of steps (i) to (iii). This additional step may remove some of the impurities in the composition, such as oxygen, nitrogen, chlorine, sulfur, or other heteroatoms. In particular, reducing the amount of oxygen may prevent the formation of solids and / or gels during step (d).

[0088] Detailed description of the first washing step (step (b))

[0089] During this first washing step (b), the composition provided in step (a), optionally pretreated as previously described, is washed with a first aqueous solution to obtain an organic phase containing the washed composition and a first aqueous effluent containing the first aqueous solution and at least some of the heteroatoms initially contained in the composition. In other words, at the outlet of this first washing step, the organic phase and the first aqueous effluent are recovered separately, for example following a liquid / liquid separation (centrifugation and / or decantation and / or other such as hydrocyclone or filtration) carried out at the end of the washing step. The washing step thus incorporates a liquid / liquid separation.

[0090] This first aqueous solution can have a neutral pH (pH=7), basic pH (pH>7) or acidic pH (pH<7).

[0091] This first aqueous solution may comprise water, and optionally some or all of the second aqueous effluent from the second washing step (d). In one embodiment, the first aqueous solution may comprise only the second aqueous effluent.

[0092] When the second aqueous effluent from the second washing step (d) is used in whole or in part as the first aqueous solution in this step, the pH of the second aqueous solution will then generally be basic, which promotes the removal of oxygenated compounds.

[0093] The first aqueous solution used may nevertheless have an acidic, basic, or neutral pH, preferably a basic pH (pH > 7). An acidic pH can be obtained by adding one or more organic or inorganic acids. Examples of usable organic acids include citric acid (C6H8O7), formic acid (CH2O2), and acetic acid (CH3COOH). Examples of inorganic acids are sulfamic acid (H3NSO3), hydrochloric acid (HCl), nitric acid (HNO3), sulfuric acid (H2SO4), and phosphoric acid (H3PO4). A basic pH can be obtained by adding oxides of alkali and alkaline earth metals, hydroxides of alkali and alkaline earth metals (e.g., NaOH, KOH, Ca(OH)2), or bi alkali and alkaline earth metal carbonates and amines (e.g. triethylamine, ethylenediamine, ammonia).

[0094] However, preferably, no basic compound other than that present in the second aqueous effluent is added to the first aqueous solution.

[0095] This first step typically allows the elimination of all or part of the oxygenated compounds (carboxylic acids, esters, carbonyls, alcohols) initially contained in the composition.

[0096] Part, or even all, of the basic compound from the second aqueous solution and present in the first aqueous solution can be neutralized during this first washing step so that the first aqueous effluent can have a neutral, or even acidic, pH, promoting the separation of the basic compound during the implementation of the second washing step.

[0097] During this washing step (b), the volume ratio of first aqueous solution to composition can 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.

[0098] Step (b) can be carried out at a temperature of 10°C to 120°C, preferably from 15°C to 95°C, more preferably from 15°C to 80°C, or within any range defined by any two of these limits, advantageously without external heating. Step (b) is typically carried out at atmospheric pressure.

[0099] Step (b) may include, or consist of, bringing the composition supplied by step (a) into contact with water and / or the second aqueous effluent in a washing section by any means known in the prior art.

[0100] For example, the composition provided by step (a) and the first aqueous solution can be introduced into tanks, reactors, or mixers commonly used in the industry, and the two components can be mixed. The contacting may involve 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 a chamber in which the two components flow in countercurrents, for example, in contact columns with suitable packing 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 co-current mode or in a cavitation chamber.

[0101] Contact may occur more than once, particularly under the conditions described above.

[0102] The washing step (b) can be implemented continuously or in batch. Detailed description of step (c)

[0103] Step (c) is a step in the treatment of the organic phase of step (b) in presence of a basic compound at a temperature of no more than 450°C to obtain an organic effluent comprising a treated composition.

[0104] This treatment makes it possible in particular to modify compounds containing heteroatoms and to promote their subsequent elimination.

[0105] Generally speaking, it should be noted that, since some, or even most, of the oxygenated compounds initially present in the composition are removed during the first washing step, the amount of basic compound required in this treatment step can be reduced compared to a process not including this first washing step. The invention thus makes it possible to save up to 40%, or even more, of the amount of basic compound used in step (c), but also to limit corrosion problems related to the presence of acidic oxygenated compounds and to limit solid formation during the washing step (d), thereby facilitating its implementation. The invention can also make it possible to reduce the amount of impurities to be removed remaining in the organic effluent containing the treated composition exiting step (c), which can make it possible to reduce the amount of water required in step (d).

[0106] Step (c) is carried out in the presence of a basic compound, preferably a nucleophilic basic compound.

[0107] Advantageously, the basic compound can exhibit a pKa in water of at least 7.5.

[0108] Advantageously, the amount of basic compound used is from 0.1 to 50%m, preferably from 0.1 to 40%m, more preferably from 0.1 to 30%m, preferably from 0.1 to 20%m, even more preferably from 0.1 to 15%m relative to the total mass of the composition treated (organic phase supplied by step (b)).

[0109] Preferably, the amount of basic compound used is at least 0.5%m, more preferably at least 1%m, even more preferably at least 3%m, even more preferably at least 5%m or even at least 10%m, and at most 50%m, 40%m, 30%m, 20%m or 15%m, relative to the total mass of the composition treated (organic phase supplied by step (b)).

[0110] In one embodiment, during step (c), the organic phase can be brought into contact with 0.1 to 15% by mass of a basic compound, preferably in the presence of water, more preferably with 0.5 to 15% by mass of a basic compound, even more preferably with 1 to 15% by mass of a basic compound, in particular 3 to 15% by mass, or even 5 to 15% by mass or 10 to 15% by mass relative to the total mass of the composition treated, or in any range defined by two of the preceding limits.

[0111] The basic compound can be added to the organic phase provided by step (b) either before step (c) or during step (c). This addition of the basic compound to the organic phase may optionally be followed by a mixing step before implementation of step (c).

[0112] The basic compound can be added to the organic phase in solid form or solubilized in an aqueous medium, preferably water. In particular, step (c) can be carried out without the addition of any solvent other than water or a solvent that may already be present in the composition.

[0113] Advantageously, the basic compound added in step (c) is in solution in water. Thus, during step (c), the organic phase can be brought into contact with an aqueous solution of a basic compound, preferably a basic compound comprising an alkali or alkaline earth metal cation. A person skilled in the art will then choose a quantity of water sufficient to dissolve / solubilize the basic compound, preferably the smallest possible quantity of water, or just enough to saturate the water with the basic compound.

[0114] Alternatively, the basic compound may be added to the organic phase solubilized in a solvent, miscible or immiscible with said organic phase.

[0115] When the basic compound is solubilized in a solvent or in water, a person skilled in the art will choose a sufficient quantity of solvent / water to dissolve / solubilize it, preferably the smallest possible quantity of solvent / water. The volume ratio of the solvent / water containing the basic compound to the organic phase, i.e., the volume ratio of the mixture (basic compound + solvent or water) to the organic phase, may be from 0.1 / 99.9 to 80 / 20, from 1 / 99 to 80 / 20, from 1 / 99 to 70 / 30, from 1 / 99 to 65 / 35, from 1 / 99 to 60 / 40, from 1 / 99 to 50 / 50, or within any range defined by any two of the aforementioned limits.

[0116] A solution, in particular an aqueous solution, saturated with a basic compound may advantageously be used.

[0117] Advantageously, the basic compound added in step (c) is in solution in water or in a solvent, and the basic compound content of the water or solvent is from 0.1 to 50% by mass, preferably from 15 to 50% by mass, more preferably from 25% to 50% by mass, preferably from 40 to 50% by mass, even more preferably the water (or solvent) is saturated with basic compound, in particular the water (or solvent) contains just enough basic compound to obtain a saturated solution.

[0118] A usable miscible solvent may be a polar solvent comprising an alcohol function and / or an ether function, ideally chosen from alcohols in Cl to C4, preferably from methanol, ethanol, propan-l-ol, propan-2-ol, butan-l-ol, butan-2-ol, 2-methylpropan-l-ol, propylene glycol.

[0119] A usable immiscible solvent may be an immiscible polar solvent.

[0120] By way of example, it may be considered that the polar solvent (or a mixture of polar solvents where applicable) 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 to the initial volume of solvent, this extract being a phase containing the solvent, immiscible with the composition containing a liquefaction oil, recovered after stirring and 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.

[0121] 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-bottom 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 of + / -0.1 mL, • Insert a magnetic rod, close the balloon with a polypropylene stopper, • Stir the mixture on a mechanical stirrer at a speed of 500 rpm for 5 minutes. • At the end of the 5 minutes, stop the 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 volumes less than or equal to 2 mL and an accuracy of + / -0.1 mL for volumes greater than 2 mL. Wait for complete separation by decantation and measure the volume of the two phases using the graduations. Complete separation is considered achieved when the volumes of the two phases no longer change.

[0122] 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 with chemical formula HO-(CH2-CH2-O)nH and average mass molar mass of 90 to 800g / mol, for example diethylene glycol and tetraethylene glycol, polypropylene glycol with chemical formula H[OCH(CH3)CH2]nOH and average mass molar mass of 130 to 800g / mol, for example dipropylene glycol and tetrapropylene glycol, - dialkyl formamides, in which the alkyl group can comprise from 1 to 8 or from 1 to 3 carbon atoms, notably dimethyl formamide (DMF), - dialkyl sulfoxides, in which the alkyl group can comprise from 1 to 8 or from 1 to 3 carbon atoms, notably dimethyl sulfoxide (DMSO) and sulfolane - compounds comprising a furan ring - cyclic carbonate esters, including those with 3 to 8 or 3 to 4 carbon atoms, notably propylene carbonate and ethylene carbonate.

[0123] One or more of the aforementioned solvents may be used. However, advantageously, only one of the aforementioned solvents may be used provided that it is immiscible with the composition containing a liquefaction oil to be purified.

[0124] Preferably, the polar solvent may be ethylene glycol or a glycol ether, in particular polyethylene glycol of chemical formula HO-(CH2-CH2-O)nH of average mass molar mass of 90 to 800g / mol or polypropylene glycol of chemical formula H[OCH(CH3)CH2]nOH of average mass 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 in mixture, preferably alone.

[0125] 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 of average molar mass of 90 to 800g / mol, alone or in mixture, preferably alone.

[0126] In one embodiment, the basic compound may comprise an oxide, hydroxide, bicarbonate, or alkoxide of an alkali metal cation or an alkaline earth metal cation, or a hydroxide or bicarbonate of a quaternary ammonium cation, for example, tetramethylammonium (TMA+), tetraethylammonium (TEA+), tetrapropylammonium (TPA+), or tetrabutylammonium (TBA+). Preferably, the basic compound may comprise one of the aforementioned oxides or hydroxides, alone or in a mixture.

[0127] In a preferred embodiment, the basic compound may be selected from LiOH, NaOH, CsOH, Ba(OH)2, Na2O, KOH, K2O, CaO, Ca(OH)2, MgO, Mg(OH)2, NH4OH, TMAOH, TEAOH, TBuOH, EtONa, MeONa, and mixtures thereof. A preferred basic compound may be selected from NaOH, KOH, and mixtures thereof, preferably in aqueous solution.

[0128] The solvent used to solubilize the basic compound can be water, an alcohol, for example methanol or ethanol, or any other organic solvent suitable for solubilizing the chosen basic compound, preferably water.

[0129] Step (c) can be carried out at a temperature of up to 450°C. In one embodiment, step (c) can be carried out at a temperature of 50 to 450°C, preferably from 50 to 350°C, more preferably from 50 to 250°C, more preferably from 50 to 225°C or from 50 to 200°C, or even from 90°C to 200°C or from 150 to 200°C or in any interval defined by any two of these limits.

[0130] Step c) of treatment can be carried out at an absolute pressure of 0.1 to 100 bars, preferably from 1 to 50 bars.

[0131] In a particularly preferred embodiment, step (c) is carried out for a duration of 1 minute to 3 hours, preferably from 1 minute to 1 or 2 hours, more preferably from 1 minute to 20 minutes, preferably from 1 minute to 16 minutes, at a temperature of at most 250°C, more preferably at most 225°C, and even more preferably at most 200°C. In this particularly preferred embodiment, step (c) may be carried out at a temperature of at least 50°C, preferably at least 90°C, and more preferably at least 150°C. In this particularly preferred embodiment, step (c) may be carried out at an absolute pressure of 0.1 to 100 bar, preferably from 1 to 50 bar.

[0132] In this particularly preferred embodiment, the organic phase can advantageously be brought into contact with:

[0133] - 0.1 to 15% by mass of a basic compound, advantageously comprising a cation of alkali or alkaline earth metal, and preferably in the presence of water, preferably with 0.5 to 15% by mass of a basic compound, more preferably with 1 to 10% by mass of a basic compound (mass percentages of basic compound relative to the organic phase), and / or

[0134] - with water containing 15 to 50% by mass of basic compound, preferably 25% to 50% by mass, preferably 40% to 50% by mass (mass percentages of basic compound relative to water), even more preferably with water saturated with basic compound.

[0135] A preferred strong base may be selected from LiOH, NaOH, CsOH, Ba(OH)2, Na2O, KOH, K2O, CaO, Ca(OH)2, MgO, Mg(OH)2, TMAOH, TEAOH, TBuOH, EtONa, MeONa and mixtures thereof. A further preferred strong base may be selected from NaOH, KOH and mixtures thereof, particularly for the implementation of the particularly preferred embodiment.

[0136] Detailed description of the optional additional separation step

[0137] Step (c) may be followed by a separation step in which the basic compound is separated from the organic effluent and returned, in whole or in part, upstream of step (c), advantageously at the inlet of step (c), the separation step being carried out by (i) filtration, (ii) centrifugation, (iii) hydrocyclone, (iv) sedimentation, or (v) a combination of two or more of these steps. This makes it possible, in particular, to reduce the quantity of basic compound used in step (c).

[0138] This optional step allows the basic compound to be recovered in aqueous solution or in solid form depending on the nature of the basic compound added in step (c). It may therefore be a liquid-liquid or liquid-solid separation depending on the case.

[0139] Detailed description of the optional additional solids separation step

[0140] Step (d) can be followed by a solids separation step by (i) filtration, (ii) centrifugation, (iii) hydrocyclone, or (iv) a combination of two or three of these steps. This optional step can facilitate the implementation of the subsequent processing step (steps (e), (f), (g), (h)), particularly when the previously described optional separation step is not carried out.

[0141] Detailed description of the second washing step (d)

[0142] In step (d), the organic effluent from step (c) is washed with a second aqueous solution. This step (d) recovers an organic phase, which forms the purified composition with a reduced heteroatom content, and a second aqueous effluent containing the second aqueous solution, the basic compound, and at least some, if not all, of the heteroatoms initially present in the treated composition. In other words, at the outlet of this second washing step, the organic phase and the second aqueous effluent are recovered separately, for example, following a liquid / liquid separation (centrifugation and / or decantation and / or other process such as hydrocyclone or filtration) carried out at the end of the washing step. The washing step thus incorporates a liquid / liquid separation.

[0143] This washing step (d) removes impurities containing heteroatoms present in the organic effluent containing the treated composition exiting step (c) by solubilizing them in water. This washing step also separates the basic compound from the purified composition.

[0144] The second aqueous solution may include water, and optionally some or all of the first aqueous effluent from the first washing step (b).

[0145] In one embodiment, the second aqueous solution may comprise only the first aqueous effluent.

[0146] In one embodiment, the second aqueous solution may comprise the first aqueous effluent to which water has been added, in particular water with a neutral or acidic pH.

[0147] The second aqueous solution used in step (d) may have a basic pH, an acidic pH (pH < 7), or a neutral pH (pH = 7). In particular, when the first aqueous solution is returned in whole or in part to the second washing step, and especially when the second aqueous solution is itself returned in whole or in part to the first washing step, the second aqueous solution used may contain some of the basic compound used in step (c) and may thus have a basic pH, generally weakly basic. An acidic pH may be obtained by adding one or Several organic or inorganic acids. Examples of usable organic acids include citric acid (C6H8O7), formic acid (CH2O2), and acetic acid (CH3COOH). Examples of inorganic acids are hydrochloric acid (HCl), sulfamic acid (H3NSO3), nitric acid (HNO3), sulfuric acid (H2SO4), and phosphoric acid (H3PO4). Preferably, the water can have a pH of 0.1 to 6.9.

[0148] In a particularly preferred embodiment, in step (b), the first aqueous effluent is returned, in whole or in part, to step (d) and added to the second aqueous solution, and in step (d), the second aqueous effluent is returned, in whole or in part, to step (b) and added to the first aqueous solution. The first and second aqueous effluents can then circulate in a circuit connecting a first washing section implementing washing step (b) to a second washing section implementing washing step (d). Such a circuit typically includes a fluid circulation device (pump or other) and forms a circulation loop for the aqueous washing media used in steps (b) and (d).Advantageously, this circuit may include a water injection device for injecting water into the circuit and a withdrawal device for extracting a portion of the fluid circulating in the circuit, so as to maintain a substantially constant fluid flow rate between the two washing sections. Preferably, the withdrawal and / or injection are carried out upstream of the second washing section, which can facilitate pH control of the second aqueous solution, as the injected water may advantageously have a neutral or acidic pH.

[0149] Step (d) can be carried out at a temperature of 10°C to 120°C, preferably from 15°C to 95°C, more preferably from 15°C to 80°C, or within any range defined by any two of these limits, advantageously without external heating. Step (d) is typically carried out at atmospheric pressure or at a pressure close to the pressure at which step (c) is carried out.

[0150] Step (d) can be implemented on the effluent directly from step (c), without an intermediate step.

[0151] During step (d), the volume ratio of second aqueous solution to effluent containing the treated composition can 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 within any interval defined by any two of the aforementioned bounds.

[0152] Step (d) may include, or consist of, contacting the effluent from step (c) with water and / or the first aqueous effluent in a washing section by any means known in the prior art. Devices similar to those described with reference to step (b) may be used.

[0153] Contact may occur more than once, particularly under the conditions presented above.

[0154] The washing step (d) can be implemented continuously or in batch.

[0155] Detailed description of the optional catalytic hvdrotreatment step (e)

[0156] The hydrotreating of step (e) can be carried out in one step or in two steps. When carried out in a single step, the purified composition from step (d) with or without dilution is hydrotreated at a temperature of 200 to 450°C, preferably 200 to 380°C in the presence of hydrogen at an absolute pressure of 20 to 140 bar, preferably 30 to 100 bar and in the presence of a hydrotreating catalyst, for example a NiMo (0.1-60% by mass) and / or CoMo (0.1-60% by mass) type catalyst, generally on a support.

[0157] Alternatively, the hydrotreating of step (e) can be carried out in a first step (e-1) in which the purified composition from step (d), with or without dilution, 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 150 bar, preferably 20 to 100 bar, and in the presence of a first hydrotreating catalyst, preferably a hydrogenation catalyst, for example, a hydrogenation catalyst comprising Pd (0.1-10 wt.%) and / or Ni (0.1-60 wt.%) and / or NiMo (0.1-60 wt.%), and in a second step (e-2) in which the effluent from step (e-1) is hydrotreated at a temperature of 200 to 450°C, preferably 250 to 340°C, in the presence of hydrogen at a pressure absolute pressure of 20 to 150 bars, preferably 30 to 100 bars and in the presence of a second hydrotreating catalyst, for example a NiMo (0.1-60% by weight) and / or CoMo (0.1-60% by weight) type catalyst.The first step can then allow the hydrogenation of dienes initially present in the composition.

[0158] The purified composition from step (d) can be hydrotreated pure or diluted, for example with a fossil hydrocarbon such as naphtha, diesel fuel, or crude oil, or another fossil hydrocarbon. For example, a concentration of purified plastic liquefaction oil can be obtained ranging from 0.01 wt% to a maximum of 50 wt%; preferably from 0.1 wt% to 25 wt%, and even more preferably from 1 wt% to 20 wt% at the inlet of the hydrotreating process.

[0159] This step (e) can be carried out in a single reactor with several catalytic beds connected in series with possibly hydrogen additions between the beds or in several reactors in series depending on the objective sought.

[0160] This hydrotreating step can also have a demetallization, cracking, dearomatization function depending on the characteristics of the catalyst and the hydrotreating conditions.

[0161] Preferably, the purified composition obtained after step (d) is sent to the hydrotreating step without being cooled and / or depressurized to the temperature and pressure at the outlet of step (d). The feed for hydrotreating, containing at least part of the purified composition, can advantageously be heated by a heat exchanger which is supplied by the effluent from hydrotreating (since hydrotreating is exothermic, the effluent from hydrotreating will have a higher temperature than the feed entering hydrotreating).

[0162] Preferably, the feed for hydrotreatment, containing at least a portion of the purified composition, can be diluted with a portion of the hydrotreatment effluent, which still has a temperature higher than the desired temperature at the hydrotreatment inlet. This at least partial recycling of the hydrotreatment effluent allows for the dilution of unsaturated solids present in the purified composition and preheats the feed.

[0163] Preferably, the part of the hydrotreatment effluent which is not recycled but still at a high temperature can exchange its sensible heat with the organic phase entering step (c) and thus ensure the preheating of the latter.

[0164] The purified composition from step (d) or the hydrotreated purified composition from step (e) can be purified 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.

[0165] The adsorbent can be operated in regenerative or non-regenerative mode, at a temperature below 400°C, preferably below 100°C, more preferably below 60°C, selected from: (i) a silica gel, (ii) a clay, (iii) crushed clay, (iv) apatite, (v) hydroxyapatite and combinations thereof, (vi) an alumina, for example, alumina obtained by boehmite precipitation, calcined alumina such as Sasol's Ceralox®, (vii) boehmite, (viii) bayerite, (ix) hydrotalcite, (x) a spinel such as Sasol's Pural® or Puralox®, (xi) a promoted alumina, for example, BASF's Selexsorb®, acid-promoted alumina, or zeolite-promoted alumina 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 Clariant's Tonsil®, (xiii) a molecular sieve in the form of an aluminosilicate containing an alkali or alkaline earth cation, for example 3A sieves,4A, 5A, 13X, for example marketed under the brand name Siliporite ® by Ceca, (xiv) a zeolite, (xv) an activated carbon, or a combination of at least two adsorbents, the adsorbent or 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. ,

[0166] According to a preferred embodiment, the adsorbent is regenerable, has a specific surface area of ​​at least 200 m2 / g and is operated in a fixed bed reactor at less than 100°C with a WH of 0.1 at 10 h'.

[0167] The effluent exiting the hydrotreating step (e), namely the purified and hydrotreated composition, optionally further purified by passing over a solid adsorbent, can be washed with water to remove inorganic compounds such as hydrosulfide, hydrogen chloride and ammonia before being subjected to further treatments.

[0168] The purified composition exiting step (d) or the effluent exiting step (e) of hydrotreating, optionally washed with water, can be fractionated into usable streams, the cut points of which are typically chosen according to the subsequent treatment. This fractionation is carried out according to distillation temperature ranges, for example, to separate streams such as LPG, gasoline, diesel, heavy fuel oil, kerosene, which can then be treated in a steam cracker and / or in a catalytic cracker and / or in a hydrocracker (and then possibly in a steam cracker) and / or in a hydrotreating reactor and / or used as is for the preparation of fuels, lubricants, or base oils. Those skilled in the art know how to select the cuts best suited to the subsequent processing units according to the desired objective.

[0169] The purified composition of step (d) or the purified and hydrotreated composition of step (e) can also be used diluted, for example mixed with naphtha, gas oil or crude oil in order to obtain, for example, a concentration of purified plastic liquefaction oil ranging from 0.01 wt% to a maximum of 50 wt%; preferably from 0.1 wt% to 25 wt%, even more preferably from 1 wt% to 20 wt% at the inlet of the next treatment.

[0170] Detailed description of the optional steam cracking step (g)

[0171] The steam cracking step (g) can be carried out on the purified composition of step (d) with or without dilution, or on the hydrotreated purified composition of step (e) with or without dilution. Prior to this step (g), a separation step by distillation can be carried out depending on the steam cracking furnace technology.

[0172] This step (g) allows the production of olefins such as ethylene and propylene and aromatics. The ethylene and propylene can then advantageously be converted into polyethylene and polypropylene respectively in a polymerization section.

[0173] Step (g) of steam cracking consists of thermally cracking, in one or more furnaces, a mixture of the purified composition and / or the purified and hydrotreated composition and steam at high temperatures of approximately 650 to 1000°C, preferably 700 to 900°C, typically 750 to 850°C, under low pressures (1 to 3 bar). The cracking reaction is carried out in the absence of oxygen. The reaction time is usually very short, on the order of a few hundred milliseconds. These conditions allow the carbon-carbon bonds to break and The process produces unsaturated hydrocarbons with molecules smaller than the feedstock introduced into the reactor(s). The effluent exiting the reactor(s) is then rapidly cooled to temperatures of 400 to 550°C to limit secondary reactions such as the polymerization of olefins, dienes, and acetylenes. The cooled effluent is then fractionated to recover light C2-C5 olefins, such as ethylene, propylene, butadiene, isobutene, n-butene, and isoprene.

[0174] The purified composition from step (d) or the purified and hydrotreated composition from step (e) can be sent to the steam cracker without dilution. The purified composition from step (d) or the purified and hydrotreated composition from step (e) can also be blended with naphtha, gas oil, or crude oil to obtain a purified plastic liquefaction oil concentration ranging from 0.01 wt% to a maximum of 50 wt%; preferably from 0.1 wt% to 25 wt%, and even more preferably from 1 wt% to 20 wt% at the steam cracker inlet. The purified composition is then converted into olefins, such as ethylene and propylene, as well as aromatics.

[0175] In a preferred embodiment, the purified composition, or purified and hydrotreated composition, can be sent at least partially directly into a steam cracker without 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.

[0176] The steam cracker is known per se in the art. The feedstock of the steam cracker, in addition to the stream obtained by the inventive process, may be ethane, liquefied petroleum gas, naphtha, or diesel fuels. Liquefied petroleum gas (LPG) is essentially composed of propane and butanes. Diesel fuels have a boiling range of approximately 200 to 350°C and consist of hydrocarbons from C10 to C22, including essentially linear and branched paraffins, cyclic paraffins, and aromatics (including mono-, naphtha-, and poly-aromatics).

[0177] In particular, the cracking products obtained at the outlet of the steam cracker may include ethylene, propylene and benzene, and possibly hydrogen, toluene, xylenes and 1,3-butadiene.

[0178] In a preferred embodiment, the outlet temperature of the steam cracker can 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 can influence the content of high-value chemicals in the cracking products obtained by this process.

[0179] 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, can be between 0.005 and 0.5 seconds, preferably between 0.01 and 0.4 second.

[0180] In a preferred embodiment, steam cracking is carried out in the presence of steam in a ratio of 0.1 to 1.0 kg of steam per kg of hydrocarbon feed, preferably 0.25 to 0.7 kg of steam per kg of hydrocarbon feed in the steam cracker, preferably in a ratio of 0.35 kg of steam per kg of feed mixture, to obtain cracking products as defined above.

[0181] In a preferred embodiment, the reactor outlet pressure can be between 500 and 1500 mbar, preferably between 700 and 1000 mbar, and more preferably around 850 mbar. The residence time of the feedstock in the reactor and the temperature must be considered together. A lower operating pressure facilitates the formation of light olefins and reduces coke formation. The lowest possible pressure is achieved (i) by maintaining the reactor outlet pressure as close as possible to atmospheric pressure at the intake of the cracking gas compressor, and (ii) by reducing the hydrocarbon pressure through dilution with steam (which has a substantial influence on slowing down coke formation). The steam / feedstock ratio can be maintained at a level sufficient to limit coke formation.

[0182] Since the purified and / or purified and hydrotreated composition has a wide carbon number distribution (or boiling points), vaporization of such a feedstock may be incomplete at the reactor inlet temperature, at which point some hydrocarbon molecules begin to decompose. The purified and / or purified and hydrotreated composition can 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 residual hydrocarbon liquid in a flash tank. In this flash tank, the liquid exits by gravity from the bottom and the hydrocarbon vapors from the top. Optionally, the hydrocarbon liquid can be returned to the plastics liquefaction unit or to the optional hydrocracking step.

[0183] Detailed description of the optional hydrocracking step

[0184] Prior to step (g) of steam cracking, the purified effluent from step (d) or the purified and hydrotreated effluent from step (e) may be subjected to a cracking reaction in order to reduce the length of the carbon chains of the paraffins present in the hydrotreated effluent.

[0185] Typically, this cracking reaction is a hydrocracking reaction carried out at a temperature of 250 to 480°C, a partial pressure of hydrogen of 1.5 to 25 MPa abs. and an hourly volumetric rate of 0.1 to 10 h*.

[0186] A usable hydrocracking catalyst includes, for example, a selected support among halogenated aluminas, combinations of boron and aluminum oxides, amorphous silica-aluminas and zeolites and a hydro-dehydrogenating function comprising at least one metal from group VIB selected from chromium, molybdenum and tungsten, alone or in mixture, and / or at least one metal from group VIII selected from iron, cobalt, nickel, ruthenium, rhodium, palladium and platinum.

[0187] In one embodiment, the hydrocracking step can be carried out by adding a hydrocracking catalyst bed downstream of the last catalytic bed of the hydrotreating section. Description of the figures

[0188] [Fig-1] The [Fig. 1] describes one possible embodiment of the invention.

[0189] [Fig. 2] Fig. 2 describes another possible embodiment of the invention.

[0190] In the figures, the same sections are designated by the same reference numerals.

[0191] In the embodiment of [Fig. 1], the plastic liquefaction oil (1) is first optionally pretreated in the pretreatment section (A) by (i) filtration, (ii) distillation, (iii) decantation, or (iv) a combination of two or three of steps (i) to (iii). The pretreated oil (2) is then sent to a first washing section (B) implementing the first washing step (b) of the process to perform a first wash W1 and obtain a first organic phase (3) and a first aqueous effluent (4). The organic phase (3) is then subjected to treatment (TT) implementing step (c) in a treatment section (C) in the presence of a basic compound (5) to produce the effluent (6) containing the treated composition. The effluent (6) from step (c) can then be sent to one or more optional separation sections (S).This may be an optional section for separating the basic compound (7') contained in the effluent by (i) filtration, (ii) centrifugation, (iii) hydrocyclone, (iv) sedimentation, or (v) a combination of two or more of these steps, with this basic compound (7') being at least partially recycled in or upstream of step (c). Alternatively, it may be an optional section for separating solids by (i) filtration, (ii) centrifugation, (iii) hydrocyclone, or (iv) a combination of two or three of these steps (in which case recycling (7') is omitted). This optional solids separation section could be located downstream of section (D). Both separation sections may also be provided.The second effluent (6) exiting section (C) or the effluent (7) exiting section (S) is then sent to a second washing section (D) implementing the second washing step (d) of the process to perform a second wash W2 and obtain a second organic phase (8) and a second aqueous effluent (9). In the embodiment shown, the first aqueous effluent (4) exiting the first washing section (B) is . The second aqueous effluent (9) exiting the second washing section (D) is sent to the first washing section (B). The second organic phase (8) exiting section (D), possibly after fractionation and / or dilution, may be sent to one or more of the following optional sections: an optional hydrotreating section (HDT) (E) for the implementation of step (e), an optional fuel preparation section (Pool) for a fuel, lubricant, or base oil (F), an optional treatment section (SC) in a steam cracker (G), an optional treatment section (FCC) in a fluidized bed catalytic cracker (H), or an optional treatment section (HCK) in a hydrocracker (I). The hydrotreating section may include one or more hydrotreating and / or selective hydrogenation units.Preferably, the effluent (10) exiting the hydrotreating section (E) is then steam cracked to obtain olefins which can then be polymerized. Preferably, the effluent (11) exiting the hydrocracking section (I) is then steam cracked to obtain olefins which can then be polymerized. In the example shown, the second organic phase (8) is sent directly to sections F, H, I, where it can be treated, typically mixed with a hydrocarbon feedstock typical of those sections. Alternatively, the effluent (10) exiting section (E) could be sent directly to sections F, H, I, where it can advantageously be treated without mixing with another feedstock.

[0192] In the embodiment of [Fig. 2], the plastic liquefaction oil (100) is introduced into a first washing section (B) to undergo the first wash W1. A first organic phase (101) and a first aqueous effluent (102) exit the first washing section (B). The first organic phase (101) is sent to the treatment section (C). Upstream of the treatment section (C), a basic compound (103) is added to the first organic phase (101) via a pipe and one or more valves. The mixture (104) of the organic phase (101) and the basic compound (103) then passes through two heat exchangers (105), (106) to be heated before entering the treatment section (C). The effluent (107) exiting the treatment section (C) is used, in particular, to heat the mixture (104) via the first heat exchanger (105).It can then be cooled in a third heat exchanger (108) before entering the second washing section (D) to undergo the second wash W2. A second organic phase (109) and a second aqueous effluent (110) exit the second washing section (D). The organic phase (109) forms the purified composition which can then be treated, for example, as described with reference to [Fig. 1].

[0193] In this embodiment, a circuit (111) connects the first and second sections washing sections (B) and (D) are supplied via a first line (112) running from the second washing section to the first, and a second line (113) running from the first washing section to the second. This circuit (111) includes a pump (114), a water injection line (115), and a withdrawal line (116), here located on the second line (113). Valves (117) and (118) allow the withdrawal line (116) and the water injection line (115) to be closed. The second aqueous effluent (110) can be sent entirely to the first washing section (B) as a washing solution, as shown. As described with reference to [Fig. 1], optional pretreatment and separation sections could be provided. Examples

[0194] Embodiments of the present invention are illustrated by the following non-limiting examples.

[0195] Example 1: Two-stage hydrotreating and steam cracking of a plastic liquefaction oil

[0196] A purified plastic liquefaction oil exiting step d) of the process according to the invention can be hydrotreated in two steps according to the following procedure:

[0197] The purified and washed liquefaction oil can be introduced into a first hydrotreating section (HDT1) primarily to hydrogenate diolefins and acetylenes. This step can include a plurality of reactors in series and / or parallel if guard reactors are used upstream or downstream of the first hydrogenation reactor. These guard reactors can reduce the concentration of certain undesirable chemical species and / or elements such as chlorine, silicon, and metals. Particularly undesirable metals include Na, Ca, Mg, Fe, As, and Hg.

[0198] A second hydrotreating section (HDT2) is dedicated to olefin hydrogenation and demetallation (HDM), desulfurization (HDS), deazolation (HDN), and deoxygenation (HDO). These two sections consist of one or more reactors operated in series, in parallel, or both. Isolated lead-lag, series, and / or parallel guard reactors may be considered depending on the nature and quantity of the contaminant in the stream to be treated.

[0199] If the treatment according to the invention does not achieve sufficient impurity removal, guard reactors to remove chlorine, metals, and silicon can be added. Silicon can also be trapped on the upper bed of a reactor in section HDT2 or separately, upstream.

[0200] Chlorine and mercury can be separated by guard reactors in liquid or gaseous phase.

[0201] Since the hydrotreating reactions in sections HDT1 and HDT2 are exothermic, quenching with cold hydrogen or dilution with an inert filler These methods can be used to moderate the temperature increase and control the reaction. Dilution with an inert feedstock can be achieved by recycling the liquid fraction exiting the reactors.

[0202] There may be intermediate quenching between the beds or between reactors HDT1 and HDT2, or no quenching at all. In the latter case, recycling of a portion of the outgoing flow from HDT1 or HDT2 must be carried out to control the temperature. Strict temperature control in HDT1 must be maintained to prevent reactor clogging and degradation of catalytic hydrogenation conditions.

[0203] The operating pressure in each of the hydrotreatments HDT1 and HDT2 is 5-150 bars, preferably 20-100 bars for HDT1 and 20-150 bars, preferably 30-100 bars for HDT2, typically 30-45 bars for HDT2.

[0204] Typical temperature range at the inlet of HDT1 at the start of run (SOR): 150-250°C. The catalyst for HDT 1 usually comprises Pd (0.1-10 wt%) and / or Ni (0.1-60 wt%) and / or NiMo (0.1-60 wt%).

[0205] Typical temperature range at the inlet of HDT2 at the start of run (SOR): 200-340°C. Typical temperature range at the outlet of HDT2 (SOR): 300-380°C, up to 450°C. The catalyst for HDT2 usually comprises a NiMo (any type of commercial catalyst for refining or petrochemical applications), potentially a CoMo in the very last beds at the bottom of the reactor (any type of commercial catalyst for refining or petrochemical applications).

[0206] The upper bed of the HDT2 should preferably be operated with NiMo having both hydrogenating and silicon-trapping capabilities. Such an upper bed can be considered a metal trap that also has HDM activity and hydrogenating capabilities. It is possible to have two separate beds in an HDT2 reactor, with quenching between the two beds or between the two reactors, if the two beds are in two separate reactors, or no quenching at all. Ideally, the intermediate quenching is carried out using cold HDT2 effluent or by adding cold hydrogen, i.e., at a temperature generally ranging from 15 to 30°C, in order to control the exothermic reaction of the HDT2.

[0207] Depending on the metals present in the liquefaction oil to be hydrotreated, a hydrodemetallation catalyst, for example commercial, can be added to the upper bed of the HDT2 section in order to protect the lower catalytic beds from deactivation.

[0208] The hydrotreated liquefaction oil leaving the HDT2 section, optionally after water washing to remove inorganic compounds (hydrosulfide, hydrogen chloride, ammonia), can be used as is or fractionated according to distillation temperature ranges, to feed a steam cracker, an FCC, a hydro cracker, a catalytic reformer or a fuel pool such as LPG, petrol, jet, diesel, fuel oil or a base oil pool.

[0209] In one embodiment, the hydrotreated liquefaction oil is sent to a hydrocracker. This hydrocracking includes, for example, contacting the hydrotreated effluent with a hydrocracking catalyst, in the presence of H2, to produce an effluent meeting the specifications of a steam cracker in terms of final boiling point (<370°C).

Claims

Demands

1. A process for 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, (b) washing the composition provided in step (a) with a first aqueous solution to obtain an organic phase containing the washed composition and a first aqueous effluent containing the first aqueous solution and at least a portion of the heteroatoms initially contained in the composition, (c) treating the organic phase of step (b) in the presence of a basic compound at a temperature of not more than 450°C to obtain an organic effluent comprising a treated composition, (d) washing the organic effluent of step (c) with a second aqueous solution and obtaining a purified composition having a reduced heteroatom content,and a second aqueous effluent containing the second aqueous solution, the basic compound and at least some of the heteroatoms initially contained in the treated composition, characterized in that: - during step (b), the first aqueous effluent is returned in whole or in part to step (d) and added to the second aqueous solution, or: - during step (b), the first aqueous effluent is returned in whole or in part to step (d) and added to the second aqueous solution, and - during step (d), the second aqueous effluent is returned in whole or in part to step (b) and added to the first aqueous solution.

2. The method according to claim 1, characterized in that the first aqueous effluent and the second aqueous effluent circulate in a circuit connecting a first washing section implementing the washing step (b) to a second washing section implementing the washing step (d).

3. The method according to claim 2, characterized in that water is injected into the circuit, optionally upstream of the second washing section, and optionally a portion of the fluid circulating in the circuit is withdrawn.

4. A method according to any one of claims 1 to 3, characterized in that prior to step (c) or during step (c), the following is added to the organic phase of step b): (i) a solid basic compound, (ii) a basic compound previously solubilized in an aqueous medium, preferably water, or (iii) a basic compound previously solubilized in a solvent.

5. A process according to any one of claims 1 to 4, wherein step (c) comprises one or more of the following features: - step (c) is carried out in the presence of 0.1 to 50 wt% of the basic compound relative to the total mass of the treated organic phase, - step (c) is carried out at a temperature of 50 to 450°C, preferably 50 to 350°C, more preferably 50 to 250°C, more preferably 50 to 225°C or 50 to 200°C, - step (c) is carried out for a duration of 0.1 seconds to 3 hours, preferably 0.1 seconds to 2 hours, more preferably 1 minute to 1 hour, even more preferably 1 minute to 20 minutes or 1 minute to 16 minutes, - the basic compound comprises an oxide, a hydroxide, bicarbonate or alkoxide of an alkali metal cation or an alkaline earth metal cation, or hydroxide or bicarbonate of a quaternary ammonium cation, alone or in mixtures,- The basic compound is chosen from LiOH, NaOH, CsOH, Ba(OH)2, Na2O, KOH, K2O, CaO, Ca(OH)2, MgO, Mg(OH)2, NH4OH, TMAOH, TEAOH, TBuOH, EtONa, MeONa and mixtures thereof.

6. A process according to any one of claims 1 to 5, characterized in that step (c) is followed by a separation step in which the basic compound is separated from the effluent and returned in whole or in part upstream of step (c), advantageously at the inlet of step (c), the separation step being carried out by (i) filtration, (ii) centrifugation, (iii) hydrocyclone, (iv) decantation or (v) a combination of two or more of these steps.

7. A method according to any one of claims 1 to 6, characterized in that step (d) is followed by a step of separating solids by (i) filtration, (ii) centrifugation, (iii) hydrocyclone or (iv) a combination of two or three of these steps.

8. A process according to any one of claims 1 to 7, wherein, prior to processing in step (b), said composition is subjected to (i) filtration, (ii) distillation, (iii) decantation, or (iv) a combination of two or three of steps (i) to (iii).

9. A process according to any one of claims 1 to 8, wherein: (e) the purified composition of step (d), pure or diluted, undergoes catalytic hydrotreatment in one or two steps to provide a purified hydrotreated composition.

10. The process according to claim 9, characterized in that the hydrotreating of step (e): - is carried out in a single step in which the purified composition of step (d) is hydrotreated at a temperature of 200 to 450°C, preferably 200 to 380°C, in the presence of hydrogen at an absolute pressure of 20 to 140 bar, preferably 30 to 100 bar, and in the presence of a hydrotreating catalyst, or - is carried out in a first step (e-1) in which the purified composition of step (d) 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 150 bar, preferably 20 to 100 bar, and in the presence of a first hydrotreating catalyst, and in a second step (e-2) in which the effluent from step (e-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 150 bar,preferably at 30 to 100 bar and in the presence of a second hydrotreating catalyst.

11. A process according to any one of claims 9 or 10, wherein the purified and hydrotreated composition exiting step (e) is further washed with water to remove inorganic compounds such as hydrosulfide, hydrogen chloride, ammonia.

12. A process according to any one of claims 1 to 11, wherein the purified composition of step (d) or the hydrotreated purified composition of step (e) is (f) used as is or separated into usable streams 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, and / or treated, pure or diluted, optionally separated into usable streams, in: (g) a steam cracker for producing olefins, and / or (h) a fluidized bed catalytic cracker, and / or (i) a hydrocracker, and then optionally in a steam cracker.

13. Installation comprising an optional pretreatment section (A), a first washing section (B), a treatment section (C), a optional separation section (S), a second washing section (D), an optional hydrotreating section (E) and / or an optional fuel or lubricant or base oil preparation section (F) and / or an optional steam cracker treatment section (G) and / or an optional fluidized bed catalytic cracker treatment section (H) and / or an optional hydrocracker treatment section (I), wherein the various sections are fluidly connected to implement the process according to any one of the preceding claims.