Process for purifying a plastic liquefaction oil composition by basic treatment under microwave irradiation

Abstract

The invention relates to a process for purifying a composition comprising a plastic liquefaction oil containing at least 20 ppm by mass of heteroatoms, including silicon, comprising: (a) contacting said composition with a basic medium consisting of a basic compound in a polar solvent selected from (i) water, (ii) a polar solvent comprising an alcohol and / or an ether functional group, and mixtures thereof, and irradiating the reaction medium with microwaves under conditions effective in heating the basic medium to a temperature at least equal to its boiling point, (b) separating the basic compound from the product obtained by contacting said composition. (Short figure: Fig. 1)

Description

Title of the invention: Process for purifying a plastic liquefaction oil composition by basic treatment under microwave irradiation Technical field of the invention

[0001] The present invention relates to a purification process by basic treatment under microwave irradiation of 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 fillers from plastic waste, notably for 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 dienes and heteroatoms, including silicon and metals. These numerous heteroatoms, including silicon and metals, are contaminants for the catalysts in the hydrotreating processes typically 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 treat the plastic liquefaction oils in order to recycle them.

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

[0005] Some of them consist of heating the plastic oil in the presence of a basic compound, generally in aqueous solution.

[0006] Patent application WO2012 / 069467 describes a process for removing siloxanes The siloxanes contained in a plastic pyrolysis oil are extracted by heat treatment between 200 and 350°C in the presence of a solid or dissolved alkali metal hydroxide. The use of 5% (wt) calcium hydroxide at 225°C does not result in a reduction of the siloxane content (Table 5, p. 12 and lines 9 to 11, p. 13). Following 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, notably to allow for the efficient removal of heteroatoms, particularly silicon. While treatments in a basic medium allow for the efficient removal of silicon, chlorine, and other heteroatoms, such as oxygen and nitrogen, the high temperatures involved can lead to secondary reactions such as the formation of gums by diene polymerization.

[0011] There is therefore a need to improve existing purification processes, and in particular to eliminate heteroatoms, especially silicon, by limiting side reactions. Summary of the invention

[0012] The invention aims to provide a process for purifying plastic liquefaction oil that significantly reduces the quantities of heteroatoms, and in particular silicon, initially present while limiting secondary reactions such as diene polymerization.

[0013] To this end, the invention proposes a method for purifying a composition comprising a plastic liquefaction oil containing at least 20 ppm by mass of heteroatoms including silicon, comprising:

[0014] (a) contacting said composition with a basic medium consisting of a basic compound in a polar solvent selected from (i) water, (ii) a polar solvent comprising an alcohol and / or an ether function, and mixtures thereof, and irradiation of the reaction medium by microwaves under conditions effective in heating the basic medium to a temperature at most equal to its boiling point at the pressure applied,

[0015] (b) a separation between the basic compound and the product resulting from the contact of said composition.

[0016] By irradiating the reaction medium with microwaves, the basic medium, and in particular the polar solvent with its ions, will absorb these microwaves and heat up rapidly. This rapid heating will improve contact by increasing the exchange surface area between the basic medium and the composition, thus facilitating the modification and processing of the composition without heating it to high temperatures. This makes it possible to process the composition while limiting, or even eliminating, secondary reactions, particularly those leading to gum formation. It also leads to increased energy efficiency through specific heating of the basic medium, as the plastic liquefaction oil has low polarity and absorbs virtually no microwaves.

[0017] The composition treated in the process according to the invention may comprise at least one of the following characteristics: - 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, preferably at most 600°C, preferably further at most 560°C, preferably at most 450°C, preferably further at most 350°C, preferably 250°C, - said plastic liquefaction oil contains more than 2 ppm by weight of metals, 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, preferably at most 5000 ppm by weight of Si, and / or at least 1 ppm by weight of Si, 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, preferably at most 5000 ppm by weight relative to the total weight of said plastic liquefaction oil, - prior to step (a), said composition may be subjected to (i) filtration, (ii) washing with water or a polar solvent immiscible with the composition, (iii) distillation, (iv) decantation, or (v) a combination of two, three or four of steps (i) to (iv).

[0018] Step (a) according to the invention may include one or more of the following features: - step (a) is carried out in the presence of 0.1 to 50% by mass of basic compound relative to the total mass of said composition, preferably from 0.1 to 15% by mass, more preferably from 1 to 15% by mass, even more preferably from 1 to 10% by mass, - the mass ratio of the basic medium to the composition is 0.1 / 99.9 to 80 / 20, preferably 1 / 99 to 60 / 40, more preferably 5 / 85 to 50 / 50, and even more preferably 10 / 90 to 45 / 55. - 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, TBAOH, MeONA, EtONA and their mixtures, - Contact is established for a duration of 1 minute to 48 hours, preferably from 5 minutes to 2 hours. - the polar solvent is chosen from (i) water, (ii) alcohols in Cl to C4, preferably methanol, ethanol, propan-l-ol, propan-2-ol, butan-l-ol, butan-2-ol, 2-methylpropan-l-ol, ethylene glycol, propylene glycol, (iii) alcohols comprising an ether function, preferably glycol ethers such as polyethylene glycol, polypropylene glycol, tetraethylene glycol, diethylene glycol, triethylene glycol, (iv) cyclic ethers, preferably tetrahydrofuran, 2-methyltetrahydrofuran, tetrahydropyran, 1,4-dioxane, and mixtures thereof, - contact is made at an absolute pressure of 0.1 to 100 bar, preferably 1 to 50 bar.

[0019] In one embodiment, the contact can be carried out continuously in a reaction zone in which the basic medium and the composition flow in co-current or counter-current flow, the basic medium being introduced in the form of droplets. This can improve the contact surface area between the phases.

[0020] In another embodiment, the contact can be made in a reaction zone in which the basic medium forms a lower phase and the composition forms an upper phase, and the microwaves irradiate the basic medium from a position located above the lower phase. This can promote contact between the basic medium evaporating under the effect of the microwaves and the composition. In particular, agitation of the phases may be expected, this agitation remaining moderate so as to maintain a superposition of the two phases.

[0021] Advantageously, during contact, the reaction medium or a contact zone can be maintained at a target temperature depending on the irradiation power and / or duration. This can further limit side reactions. The target temperature can be chosen from a range of 40 °C to 150 °C, preferably from 60 to 115 °C.

[0022] Step (b) may be preceded or followed by a solids separation step by (i) filtration, (ii) centrifugation, (iii) hydrocyclone or (iv) a combination of two or more of these steps.

[0023] The separation of step (b) can be carried out by (i) washing with a polar solvent, (ii) distillation, or (iii) by a combination of these steps (i), (ii).

[0024] When step (b) includes a washing step (i), it can be carried out with water at neutral, basic or acidic pH, or with an alcohol, in particular a C1-C3 alcohol.

[0025] The product resulting from the separate contact in step (b) may advantageously undergo a purification step (c) 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.

[0026] Advantageously, the product obtained from separate contact in step (b), optionally purified in step (c), can undergo (d) catalytic hydrotreatment, namely catalytic treatment under hydrogen, in one or two steps to provide a purified hydrotreated composition.

[0027] The hydrotreatment of step (d):

[0028] can be carried out in a single step in which the product resulting from the separate contact in step (b), optionally purified in 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 bar, preferably 30 to 100 bar, and in the presence of at least one hydrotreating catalyst, or

[0029] can be carried out in a first step (d-1) in which the product from the separate contact in step (b), optionally purified in 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 bar, preferably 20 to 50 bar, and in the presence of at least one first hydrotreating 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 bar, preferably 30 to 100 bar, and in the presence of at least one second catalyst hydrotreatment.

[0030] Advantageously, the hydrotreated composition exiting step (d) can further be washed with water to remove inorganic compounds such as hydrosulfide, hydrogen chloride, ammonia.

[0031] Advantageously, the product resulting from the separate contact in step (b), optionally purified in step (c), or the hydrotreated composition from step (d), optionally washed with water, can be:

[0032] (e) subjected, pure or diluted, optionally after separation into usable streams, to a steam cracking step, and / or,

[0033] (f) subjected, pure or diluted, optionally after separation into usable streams, to a catalytic cracking step in a fluidized bed, and / or,

[0034] (g) subjected, pure or diluted, optionally after separation into usable streams, to a hydrocracking step, and / or,

[0035] (h) subjected, pure or diluted, optionally after separation into usable streams, to a catalytic hydrogenation step, and / or,

[0036] (i) used as is or separated into usable streams for fuel preparation and fuels such as LPG, petrol, diesel, heavy fuel oil and / or for the preparation of lubricants and / or base oils.

[0037] In a preferred embodiment, the product obtained from the separate contact in step (b), optionally purified in step (c), or the hydrotreated composition of step (d), 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, optionally after a hydro cracking step.

[0038] The olefins thus produced can then be used to manufacture new polymers by polymerization.

[0039] 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.

[0040] The use of the purification process according to the invention makes it possible to reduce the heteroatom content, and in particular silicon, of a composition comprising a plastic liquefaction oil as defined in this application. The reduction of the content of other heteroatoms, such as nitrogen, chlorine, and / or oxygen, can also be achieved by the process according to the invention. Definitions

[0041] For the purposes of this description, the following definitions are given:

[0042] 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.

[0043] 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.).

[0044] 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.

[0045] 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.

[0046] Unless otherwise indicated, measurements given in parts per million (ppm) are expressed by weight.

[0047] The terms "alkane" or "alkanes" used herein describe branched or unbranched acyclic hydrocarbons having the general formula CnH2n+2, and thus consisting entirely of saturated hydrogen and carbon atoms; see, for example, IUP AC. Compendium of Chemical Terminology, 2nd edition (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-".

[0048] The terms "olefin" or "alkene" used here refer to an unsaturated hydrocarbon compound containing at least one carbon-carbon double bond. They are sometimes designated by the symbol "HC=".

[0049] The term "alkyne" used here refers to an unsaturated hydrocarbon compound containing at least one carbon-carbon triple bond.

[0050] The term "hydrocarbon" refers to both alkanes (saturated hydrocarbons), cycloalkanes, aromatics and unsaturated hydrocarbons.

[0051] The Hourly Volumetric Velocity (WH) is defined as the hourly volume of charge flux per unit catalytic volume and is expressed here in h*.

[0052] By "heteroatom" is meant any element of an organic compound other than carbon and hydrogen.

[0053] The concentration of heteroatoms 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 are able to identify the most suitable method for measuring each metal and, more generally, each heteroatom, depending on the matrix. The hydrocarbon content is considered. 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.

[0054] The diene value (DV) or maleic anhydride value (MAV) corresponds to the amount of maleic anhydride (expressed in 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 in grams of diiodine per 100 grams 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.

[0055] The term "Bramine Number" refers to the amount of bromine in grams that reacted with 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.

[0056] The term "Bramine value" is the number of milligrams of bromine that react with 100 g of sample. It is determined in milligrams of Br2 per 100 g of solution (mg Br2 / 100g) and can be measured according to ASTM D2710 or ASTM D5776 methods.

[0057] 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 relies on techniques known in the trade, and several methods adapted according to the distillation temperature range are applicable, for example, NF EN 15199-1 (version 2020) or ASTM D2887 for measuring the boiling points of petroleum fractions by gas chromatography, ASTM D7169 for heavy hydrocarbons, and ASTM D7500, D86, or DI 160 for distillates.

[0058] The term "polar solvent" as used in this patent application covers all chemical species, alone or in mixtures, comprising at least one bond covalent carbon-hydrogen, carbon-halogen, carbon-chalcogen or carbon-nitrogen and having a non-zero dipole moment, as well as water.

[0059] The term "solvent" includes the aforementioned "polar solvents" and nonpolar 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.

[0060] 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.

[0061] 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.

[0062] 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, steam pyrolysis,....).

[0063] The hydrothermal liquefaction (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 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.

[0064] The expression "plastic liquefaction oil" or "oil resulting from the liquefaction of plastic" or "plastic waste liquefaction oil" or "plastic oil" refers to liquid hydrocarbon products obtained from the pyrolysis or hydrothermal liquefaction of plastics, namely thermoplastic and / or thermosetting polymers, alone or in mixtures, and generally in waste form, optionally mixed with at least one other feedstock, in particular in waste form, such as biomass, for example chosen from lignocellulosic biomass, paper and cardboard, and / or an elastomer, for example possibly vulcanized latex or tires.

[0065] 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 defined as 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), acrylonitrile-butadiene-styrene (ABS), polybutylene, poly(butylene terephthalate) (PBT), polyvinyl chloride (PVC), polyvinylidene chloride, polyester, polyamide, polycarbonate, polyether, epoxy polymer, polyacetal, polyimide, polyesteramide, silicone, etc.In general, any polymer or mixture of polymers capable of producing hydrocarbons by liquefaction can be used.

[0066] 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 food: 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, vineyards, orchards, olive groves, fruits and vegetables, food processing 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.).(viii) algal biomass, namely biomass formed from algae, for example microalgae (algal biomass can be an algal suspension obtained by harvesting algae from, for example, a bioreactor, or an algal residue obtained by dehydrating an algal suspension) or macroalgae; (ix) herbaceous biomass; (x) vegetable oils contained in certain waste (cashew nut shells or other); (xi) industrial waste (type B wood), (xii) sewage sludge, (xiii) digestate from methanizers; (xiv) vinasse from the production of alcohols by fermentation.

[0067] 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 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 polychloroprenes (CR), polyurethanes, silicone elastomers, etc.

[0068] By "hydrotreating" is meant any process in which hydrocarbons react with dihydrogen, typically under pressure, in the presence or not of 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).

[0069] 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.

[0070] 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

[0071] Description of the composition comprising a plastic liquefaction oil

[0072] The composition dealt with in the present invention comprises a plastic liquefaction oil.

[0073] In one embodiment, the plastic liquefaction oil is obtained from waste comprising at least 50% by mass, preferably at least 60% by mass, more preferably at least 70% by mass, more preferably at least 80% by mass, and up to 100% by mass, of plastic waste, the remainder being elastomer and / or biomass waste, in particular lignocellulosic biomass, herbaceous biomass, aquifer biomass, paper, cardboard, organic waste (forestry, agricultural, industrial and / or household waste), food waste, alone or in mixture.

[0074] Preferably, the plastic liquefaction oil is obtained:

[0075] - from waste containing no more than 50% by mass of tires and / or vulcanized polymers, for example from 0 to 50% by mass, preferably no more than 30% by mass, preferably more but no more than 10% by mass of tires and / or vulcanized polymers, and / or

[0076] - from waste containing no more than 30% biomass by mass, by example of 0 to 30% by mass of biomass, preferably no more than 10% by mass of biomass.

[0077] In one embodiment, the composition may comprise only a plastic liquefaction oil, in particular only a plastic pyrolysis oil and / or only a plastic hydrothermal liquefaction oil.

[0078] Alternatively, the composition may include at least 1% by mass of plastic liquefaction oil. The remainder may then consist of up to 99% by mass 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.

[0079] 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.

[0080] The composition may further include a component derived from biomass, biomass waste or elastomeric waste, such as tall oil, used cooking oil, animal fat, vegetable oil such as rapeseed, canola, castor, palm, soybean oil, oil extracted from algae, 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, elastomeric liquefaction oil, for example latex, possibly vulcanized, or tires, as well as mixtures thereof.

[0081] The composition may further comprise a diluent miscible with the plastic liquefaction oil. This diluent preferably has a diene value of at most 0.5 g I₂ / 100 g, for example from 0 to 0.5 g I₂ / 100 g, measured according to UOP 326, and a bromine value of at most 5 g Br₂ / 100 g, for example from 0 to 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 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 a boiling range between 150°C and 250°C or a boiling range between 200°C and 350°C, preferably having a bromine value of at most 5 gBr2 / 100g, for example from 0 to 5 g Br2 / 100 g, and / or a diene value of at most 0.5 gI2 / 100g, for example from 0 to 0.5 g I2 / 100 g, and / or the effluent from the optional hydrotreating step of the process according to the invention, or any combination thereof.

[0082] The diluent can be added at a concentration of up to 80% by weight, preferably up to 50% by weight, for example from 1 to 50% by weight, preferably from 1 to 30% by weight, and even more preferably from 1 to 10% by weight. Optionally, the diluent can be separated at the outlet of the optional hydrotreating step by flash or distillation and, preferably, recycled at the inlet of this hydrotreating step.

[0083] The composition addressed in the present invention may have a bromine value of at most 150 g Br2 / 100g, preferably of at most 100 g Br2 / 100g, even more preferably of at most 80 g Br2 / 100g, the most preferred being at most 50 g Br2 / 100g, as measured according to ASTM DI 159. In general, the composition addressed in the present invention has a bromine value of at least 1 g Br2 / 100g.

[0084] The composition used in the present invention may have a heteroatom content of at least 20 ppm, including silicon, and generally of at most 30% by mass of heteroatoms, most often at most 10% by mass of heteroatoms.

[0085] In the composition dealt with in the present invention, at least 10% by weight, preferably at least 15% by weight, preferably at least 25% by weight, preferably still at least 50% by weight of said composition may have a boiling point of at least 150 °C relative to the total weight of said composition.

[0086] The process according to the invention may further include a step of supplying the composition, comprising:

[0087] (al) a step of supplying a stream of plastic waste,

[0088] (a2) a waste liquefaction step and obtaining a product of hydrocarbons comprising a gaseous phase, a liquid phase and a solid phase,

[0089] (a3) ​​a step of recovering the liquefaction effluent and separating the liquid phase of said product, said liquid phase forming a plastic liquefaction oil,

[0090] (a4) an optional step of mixing the plastic liquefaction oil with a thinner or solvent.

[0091] The liquefaction step (a2) may include a pyrolysis step, typically carried out at a temperature of 300 to 1000°C or 400 to 700°C, this pyrolysis being by for example, rapid pyrolysis, flash pyrolysis, catalytic pyrolysis, or hydropyrolysis.

[0092] Alternatively or in combination, the liquefaction step (a2) 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.

[0093] The waste supplied at step (al) may be plastic waste possibly mixed with biomass and / or elastomers, as previously described.

[0094] The recovery and separation step (a3) ​​eliminates the gaseous phase, essentially C1-C4 hydrocarbons and the solid phase (typically char) to recover only the liquid organic phase (also called "remaining fraction" in this application) forming a liquefaction oil.

[0095] Plastic liquefaction oils contain, in particular, paraffins, i-paraffins (isoparaffins), 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, and phosphorus compounds.

[0096] The composition of the plastic liquefaction oil depends on the nature of the plastic liquefied, and optionally on any other waste (biomass and / or elastomers) liquefied with the plastic, and is essentially (in particular more than 80% by mass, most often more than 90% by mass) made up of hydrocarbons having from 1 to 150 carbon atoms and impurities.

[0097] A plastic liquefaction oil typically comprises 5 to 80% by mass of paraffins (including cycloparaffins), 10 to 95% by mass of unsaturated compounds (including olefins, dienes, and acetylenes), and 5 to 70% by mass of aromatics. These contents can be determined by gas chromatography.

[0098] 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 (UOP 326) of 1 to 55 mg Maleic Anhydride / lg.

[0099] A plastic liquefaction oil may have a diene index of at most 50 g I2 / 100 g, preferably of at most 25 g I2 / 100 g, preferably even more of at most 10 g I2 / 100 g, measured according to UOP 326. A plastic liquefaction oil may typically have a diene index of at least 0.5 g I2 / 100 g measured according to UOP 326.

[0100] 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 standard NF EN 15199-1 / 2).

[0101] A plastic liquefaction oil typically comprises at least 20 ppm of heteroatoms, or even at least 30 ppm of heteroatoms, including silicon, and typically at most 30% by mass of heteroatoms, most often at most 10% by mass of heteroatoms.

[0102] A plastic liquefaction oil may, in particular, further comprise one or more of the following heteroatom contents: 0 to 8% w / w oxygen (e.g., measured according to ASTM D5622), 1 to 20,000 ppm nitrogen (e.g., measured according to ASTM D4629), 2 to 20,000 ppm sulfur (e.g., measured according to ISO 20846), 1 to 10,000 ppm metals, in particular more than 2 ppm (e.g., measured by ICP), 1 to 6,000 ppm chlorine, preferably not more than 5,000 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 D4629). D7359-18), 1 to 5000 ppm of silicon, preferably at most 1000 ppm (e.g. measured by XRF), at least 1 ppm of P, preferably at most 5000 ppm of P.

[0103] Detailed description of the optional pre-treatment step _ of the composition treated in step (a)

[0104] Before step (a), the invention may include an optional pretreatment step in which the composition is subjected to (i) filtration, (ii) washing with a polar solvent immiscible with the composition, (iii) distillation, (iv) decantation, or (v) a combination of two, three, or four of steps (i) through (iv). 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 a subsequent hydrotreatment step.

[0105] During the additional washing step (ii), the polar solvent / composition volume ratio 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.

[0106] When water is used for washing (ii), it may have an acidic, basic, or neutral pH. An acidic pH may 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 may be obtained by adding oxides of alkali and alkaline earth metals, and hydroxides of alkali and alkaline earth metals. earths (e.g. NaOH, KOH, Ca(OH)2), alkali and alkaline-earth metal bicarbonates and amines (e.g. triethylamine, ethylenediamine, ammonia).

[0107] The polar solvent may have a density higher or lower than the density of the composition comprising a plastic liquefaction oil.

[0108] In particular, the density of the polar solvent may be 3 to 50% higher or lower than that of the composition.

[0109] The polar solvent is a solvent that is not miscible with the composition comprising a plastic liquefaction oil to be purified.

[0110] By way of example, a solvent for which a ratio is obtained defined as the ratio of the volume of polar solvent after washing to the initial volume of polar solvent greater than or equal to 0.95, the volume of polar solvent after washing corresponding to a phase containing said polar solvent, immiscible with the composition and recovered after stirring and decanting a mixture of one part by volume of polar solvent with twenty-five parts by volume of said product at atmospheric pressure and at a temperature of 20°C, may be considered as immiscible with the composition.

[0111] Acceptable immiscible polar solvents include, in addition to water, (i) sulfur compounds, for example dimethyl sulfoxide, (ii) nitrogen compounds, for example N,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.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] Description of step (a) of treatment with a basic medium under microwave irradiation

[0116] Step (a) is a step of processing the composition in the presence of a basic medium under microwave irradiation, the product of which contains the modified composition.

[0117] This treatment makes it possible, in particular, to modify compounds containing heteroatoms, especially those containing silicon, in the composition and to promote their subsequent removal. In particular, despite the complexity of the hydrocarbon matrix, microwave irradiation makes it possible to selectively heat the basic medium due to the presence of a polar solvent, and thus reduce the temperature increase of the composition, reducing, or even eliminating, side reactions.

[0118] Microwaves are electromagnetic waves of a specific wavelength and frequency range, situated between infrared and radio frequencies in the electromagnetic spectrum. Microwaves typically have a frequency of 300 MHz to 300 GHz (wavelength from 1 m to 1 mm). Examples of usable microwave frequencies are 0.915 GHz, 2.45 GHz, 5.8 GHz, 24 GHz, or any other frequency within the range of 300 MHz to 300 GHz.

[0119] Microwaves can be generated by one or more microwave generators, for example, arranged around or within a reaction zone containing the reaction medium. Optionally, one or more waveguides may be provided to guide the microwaves towards the reaction medium. The microwaves are generated by a system at a specific frequency; it may be a magnetron or any other electronic system, corresponding to a specific wavelength. Wave propagation within the reaction zone can be single-mode or multi-mode depending on the dimensions of the reaction zone.

[0120] The treatment of step (a) can be implemented in any device allowing contact between the basic medium and the composition, and comprising one or more microwave generators or magnetrons, and optionally one or more waveguides.

[0121] The reaction zone in which the composition and the basic medium are brought into contact may include one or more reactors equipped with microwave generator(s), operating continuously in co-current or counter-current, or one or more reactors equipped with microwave generator(s) and optionally with one or more mixers, operating discontinuously (in batch).

[0122] When contact is continuous, it is generally preferable to circulate the basic medium in a downward direction, while the hydrocarbon charge can circulate in either an upward or downward direction. Preferably, the basic medium is contacted with the composition in the form of droplets. This can be achieved using one or more suitable injection devices or one or more static mixers, possibly under turbulent flow conditions.

[0123] A turbulent flow regime can be 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 flow regime can advantageously be achieved using at least one static mixer. That is to say, the composition and the basic medium are introduced into at least one tube equipped with at least one internal element capable of generating the turbulent flow regime having a Reynolds number of at least 2000.

[0124] Due to the difference in polarity between the basic medium and the compound, microwave irradiation will selectively heat the compound droplets efficiently and rapidly. These droplets are thus likely to explode by superheating into smaller droplets, promoting exchange and reaction, and this with a low amount of energy.

[0125] When contact is carried out discontinuously (in batch mode), in the reaction zone, the basic medium forms a lower phase and the composition forms an upper phase. It is then preferable to irradiate the basic medium from a position located above the lower phase, in order to promote heating of the basic medium near the interface with the upper phase and mixing with the latter. In particular, when the basic medium begins to boil near its interface with the composition, droplets of basic medium are projected into the composition and explode inside the composition causing agitation of the reaction medium and promoting the reaction.

[0126] As an example, devices sold by the companies Sairem or Tomocon can be used to implement step (a).

[0127] According to the invention, the composition to be treated is brought into contact with a basic medium consisting of a basic compound in a polar solvent chosen from (i) water, (ii) a polar solvent comprising an alcohol function and / or an ether function, and mixtures thereof.

[0128] Advantageously, the amount of basic compound used can be from 0.1 to 50% by mass, preferably from 0.1 to 15% by mass, more preferably from 1 to 15% by mass, even more preferably from 1 to 10% by mass, in particular from 1 to 5% by mass, relative to the total mass of the composition treated.

[0129] 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 of a tetramethylammonium (TMA+), tetraethylammonium (TEA+), tetrapropylammonium (TPA+), tetrabutylammonium (TBA+) cation, alone or in mixture.

[0130] The basic compound can, for example, be chosen from LiOH, NaOH, CsOH, Ba(OH)2, Na2O, KOH, K2O, CaO, Ca(OH)2, MgO, Mg(OH)2, EtONa, MeONa, NH4OH, TEAOH, TBAOH, TMAOH, and mixtures thereof. Their concentrations will be limited, in particular, by their solubilities in the chosen solvents.

[0131] In the preferred embodiment, the basic compound may comprise an oxide or hydroxide of an alkali metal cation or an alkaline earth metal cation, alone or in mixture, preferably a hydroxide of an alkali metal cation or an alkaline earth metal cation.

[0132] A particularly preferred basic compound may be selected from NaOH, KOH and their mixtures, advantageously in a polar solvent selected from water and / or methanol.

[0133] The basic compound can be added to the composition in suspension or in solution in the polar solvent.

[0134] Polar solvents, due to their ability to be polarized, are capable of absorbing microwaves, which increases their temperature. The ability of a material to be polarized can be expressed by the electrical permittivity (denoted e*) of the material, which is a complex number having a real part and an imaginary part, usually expressed by the equation e*=e'-je”, where e': real permittivity (F / m), e”: imaginary permittivity (F / m), e*: complex permittivity (F / m).

[0135] The tangent delta (δ), or loss tangent, or loss factor, is the dissipation factor of the sample, or the efficiency with which microwave energy is converted into thermal energy. This delta angle, or loss angle, corresponds to the angle at which the material is out of phase with respect to the electric field. The delta tangent parameter thus represents the capacity of a substance to convert electromagnetic energy into heat at a given frequency and temperature. It is defined as the ratio of the imaginary and real parts of the permittivity: tan δ = δ' / ε'.

[0136] The real permittivity is considered to be in phase with the alternating electric current, and the imaginary permittivity represents the phase lag, that is, the tangent of the angle between the sum of the two parts (complex permittivity). The real permittivity is equal to the imaginary part divided by the real part. The loss tangent (tan θ) can be used to represent the fraction of stored energy lost per oscillation period of the field.

[0137] The choice of the polar solvent can thus be made according to the loss tangent of this solvent at the microwave frequency used in the process, the solvent having the highest loss tangent value being able to be heated the fastest, which makes it possible to reduce the contact time.

[0138] Furthermore, the relationship between the dielectric properties and the intensity of the microwave power within the product is characterized by the penetration depth. The penetration depth with respect to microwave power is defined as the distance within the product at which the incident power is reduced to 1 / e (e = 2.7183) of its value at the surface; that is, approximately 65% ​​of the incident power is reduced between the surface and this distance. When the material absorbs very little, it is considered transparent; this is the case, for example, with polyethylene and polystyrene. In general, the penetration depth decreases as the frequency increases. Temperature also plays a role. In the case of water, at a frequency of 2.45 GHz, the penetration depth is 2.88 cm at room temperature and increases to 55 mm at 100 °C. At a frequency of 915 MHz, the water penetration depth is 76.51 cm at room temperature.Furthermore, for a given solvent at a given frequency, the penetration depth will also vary depending on its basic compound content. This penetration depth is generally greater when the basic compound concentration decreases. In addition, the density of the basic medium increases with its basic compound concentration, which can make contact more difficult. It may therefore be advantageous to limit the concentration of the basic compound in the basic medium (i.e., to use a more dilute basic medium). It may then be preferable to increase the volume of basic medium used.

[0139] It is thus understood that a person skilled in the art can choose the microwave frequency according to the depth of penetration of the basic medium considered and the dimensions of the reaction zone.

[0140] The polar solvent used in the present invention is chosen from (i) water, (ii) a polar solvent comprising an alcohol function and / or an ether function, and mixtures thereof.

[0141] When the polar solvent includes an alcohol functional group, it is preferably a primary or secondary alcohol, more preferably a primary alcohol, for example methanol. This can further reduce side reactions.

[0142] A polar solvent comprising an alcohol functional group and / or an ether functional group may advantageously be chosen from: - alcohols in the C1 to C4 groups, preferably methanol, ethanol, propan-l-ol, propan-2-ol, butan-l-ol, butan-2-ol, 2-methylpropan-l-ol, ethylene glycol, propylene glycol, and more preferably alcohols in the C1-C3 groups, and in particular primary alcohols, for example methanol, - alcohols comprising an ether function, preferably glycol ethers such as polyethylene glycol (PEG), tetraethylene glycol, polypropylene glycol, for example a PEG with an average molar mass of 200g / mol, more preferably diethylene glycol, triethylene glycol, polyethylene glycol, - cyclic ethers, preferably tetrahydrofuran, 2-methyltetrahydrofuran, tetrahydropyran, 1,4-dioxane, - and mixtures thereof.

[0143] Preferably, the polar solvent may be chosen from water and / or an alcohol, in particular a C1-C3 or C1-C4 alcohol, optionally mixed with a cyclic ether to improve the homogeneity of the solvent mixture.

[0144] Advantageously, the basic compound can be added in step (a) in solution or in suspension in the polar solvent, and the content of the basic compound in the polar solvent can be from 0.1 to 50% by mass, preferably from 1% to 30% by mass, more preferably from 5 to 25% by mass.

[0145] When the solvent is water, it may advantageously have a pH greater than 7, for example from 7.1 up to a pH approaching the saturation of the compound in water, preferably from 8 to 14, more preferably from 9 to 14, or within any range defined by two of these limits. Preferably, a pH greater than 10 or greater than 12 is chosen, more preferably a pH of at least 12.5.

[0146] The conditions for implementing step (a) may nevertheless advantageously allow the amount of basic compound used to be reduced.

[0147] The mass ratio of the basic medium / composition, i.e. the mass ratio of the mixture (basic compound + polar solvent) / composition, may be from 0.1 / 99.9 to 80 / 20, preferably from 1 / 99 to 60 / 40, more preferably from 5 / 85 to 50 / 50, even more preferably from 10 / 90 to 45 / 55.

[0148] During step a), the reaction medium, comprising the composition to be treated and the basic medium, is irradiated by microwaves under conditions effective in heating the basic medium to a temperature at most equal to its boiling point at the pressure applied.

[0149] Thus, in general, the basic medium can be heated to a temperature high enough to vaporize at least part of the solvent, for example, by being heated to a temperature at which solvent vapor bubbles appear, but at most equal to the boiling point of the basic medium, at the pressure applied. This temperature at which vapor bubbles appear corresponds approximately to a temperature 5 to 15 °C lower, for example 10 °C lower, than the boiling point of the polar solvent (taken alone, without a basic compound). Since temperature can only be measured on a more global scale, this phenomenon is due to a temperature gradient between the surface and the core of the solvent or basic solution.

[0150] Thus, advantageously, the basic medium can advantageously be heated to a (minimum) temperature 5 to 15 °C lower than the boiling point of the polar solvent (without the basic compound), for example a minimum temperature 10 °C lower than the boiling point of the polar solvent (without the basic compound).

[0151] It may happen that, at the applied pressure, the polar solvent, or one of its components, decomposes at its boiling point. In this case, it is advantageous to heat the polar solvent to a temperature of maximum stability, namely to the highest possible temperature before decomposition. For example, the temperature can be set 5 to 15 °C, preferably 10 °C, below the decomposition temperature of the polar solvent (taken alone, without any basic compound) at the applied pressure.

[0152] The implementation temperature of step (a) thus depends on the nature of the basic medium. It is typically in the range of 40 to 150 °C, preferably from 60 to 115 °C.

[0153] The conditions for implementing step (a) can be determined by a person skilled in the art through tests and / or modeling, depending on the basic compound, the nature of the polar solvent, the power of the irradiated microwaves, the duration of irradiation, and the basic medium / composition ratio.

[0154] By way of example, these conditions include one or more of the following: - microwave frequencies in the range of 300 MHz to 300 GHz, for example 0.915 GHz, 2.45 GHz, 5.8 GHz, 24 GHz, - an absolute pressure of 0.1 to 100 bar, preferably from 1 to 50 bar, preferably more at atmospheric pressure, - a contact duration of 1 minute to 48 hours, preferably from 5 minutes to 2 hours, preferably longer from 5 minutes to 1 hour.

[0155] When the basic medium reaches a temperature at most equal to its boiling point at the applied pressure, the solvent vapor bubbles formed in the medium increase the contact surface area between the composition and the basic compound, thus promoting the treatment. Since microwave irradiation heating is rapid and localized, the temperature of the reaction medium can remain relatively low during the contact time, for example below 150 °C, or even below 130 °C, for example on the order of 100 °C, which considerably limits side reactions.

[0156] Preferably, during contact, the reaction medium or a contact zone can be maintained at a target temperature depending on the irradiation power and / or duration. This target temperature can be chosen from the range of 40 to 150 °C, preferably from 60 to 115 °C.

[0157] This control can be achieved by placing a thermocouple inside the reaction zone and regulating the irradiation power and / or the duration of irradiation so as to maintain the desired temperature inside the reaction zone.

[0158] Alternatively or in combination, the control can be achieved by measuring the incident microwave power and the microwave power reflected by the reaction medium, and by regulating the incident microwave power and / or the irradiation time so as to maintain a reflected microwave power / incident microwave power ratio at a target ratio for which the reaction medium, or a contacting reaction zone, is at the target temperature. This target ratio can be determined beforehand by tests.

[0159] For example, a high irradiation power can be applied at the beginning of the contact, and then, once the target temperature is reached, this power can be reduced. The reaction medium can then be irradiated intermittently. Advantageously, the ratio of basic medium to composition can be as high as possible, which can make it possible to reduce the power and / or duration of irradiation to reach the desired temperature, particularly when the concentration of the basic compound in the basic medium is low.

[0160] The product resulting from the contacting, which thus includes the modified composition, can then be separated, and possibly further processed.

[0161] Detailed description of the optional additional step of separating solids

[0162] Step (b) may be preceded or 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 solids separation step may facilitate phase separation in step (b) by removing all or part of the solids present in the product from step (a).

[0163] Detailed description of separation step (b)

[0164] The separation of step (b) can be carried out by (i) washing with a polar solvent, (ii) distillation, or (iii) by combining these steps (i), (ii).

[0165] This step makes it possible to separate a phase containing the purified composition having a reduced content of heteroatoms, and in particular at least of silicon, and advantageously a reduced content of other heteroatoms, and in particular of chlorine, nitrogen, oxygen.

[0166] Step (c) may include a washing step (i) to recover a phase containing the purified composition and a phase containing the solvent used for washing, salt and impurities.

[0167] In other words, at the exit of the washing stage, 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 stage.

[0168] This step (i) makes it possible to remove impurities containing heteroatoms, and in particular silicon, present in the effluent exiting step (b) by solubilizing them in a polar solvent (water or an organic solvent).

[0169] The solvent may be a polar solvent selected from (i) water, (ii) a polar solvent comprising an alcohol function and / or an ether function, (iii) a solvent immiscible with the product of contacting, and mixtures thereof.

[0170] A polar solvent comprising an alcohol function and / or an ether function is advantageously as defined in step (a).

[0171] The same solvent as that used in step (a) may or may not be used.

[0172] A usable immiscible polar solvent is described for example in the optional pretreatment step.

[0173] In a preferred embodiment, the polar solvent is chosen by water or an alcohol, preferably a C1-C3 alcohol.

[0174] The water used may have an acidic pH (pH<7), basic pH (pH >7) or neutral pH (pH=7), preferably a neutral pH.

[0175] In one embodiment, the water used has an acidic or neutral pH. In particular, the water used does not contain any basic compound and, specifically, does not contain any basic compound comprising an alkali metal or alkaline earth metal cation.

[0176] An acidic pH can be obtained by adding one or more organic or inorganic acids. Examples are given with reference to washing (ii) of the optional pretreatment step. Preferably, the water can have a pH of 0.1 to 6.9.

[0177] A basic pH can be obtained by adding a basic compound, for example those used in step a). Preferably, the water can have a pH of 7.1 to 14.

[0178] 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.

[0179] During step (b), the polar solvent / effluent volume ratio 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 in any interval defined by any two of the aforementioned bounds.

[0180] Step (b)(i) may include, or consist of, contacting the effluent from step (a) with a polar solvent by any means known in the prior art.

[0181] For example, the effluent from step (a) and the polar solvent can be introduced into tanks, reactors, or mixers commonly used in the industry, and the two components can be mixed. 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, 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 contact between the phase of the treated composition and the polar solvent. Alternatively, contacting may be carried out in a static mixer in co-current mode or in a cavitation section.

[0182] This contact may occur more than once, particularly under the conditions described above. For example, two or more washes may be carried out, for example two to four washes.

[0183] The washing step (b)(i) can be carried out continuously or in batch.

[0184] Step (b) may include a distillation step (ii). A person skilled in the art will be able to implement this step under appropriate conditions to recover the purified composition. Step (ii) of distillation can be carried out at atmospheric pressure or under reduced pressure, preferably at atmospheric pressure. This step can be carried out in a distillation column or similar equipment.

[0185] Step (b) may include one or more of steps (i) to (ii) depending on the desired separation objective. In preferred embodiments, step (b) may include:

[0186] at least one washing step (i), optionally followed by at least one distillation step (ii), or

[0187] at least one distillation step (ii), optionally followed by at least one washing step (i)

[0188] The product resulting from the contact of step a) separated in step b) thus forms a modified composition having a reduced content of heteroatoms.

[0189] The sequence of steps (a) and (b) can make it possible to remove at least 20% by mass of the silicon content, or even at least 30% by mass of silicon, particularly without having to heat the composition to be treated or at a moderate temperature. Steps (a) and (b) may optionally be repeated in order to further reduce the silicon content, and possibly also the content of other heteroatoms.

[0190] Detailed description of the optional purification step (c)

[0191] The process may also include a purification step (c) by passing over a solid adsorbent. This is thus a trapping step.

[0192] The modified composition from step (b) 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.

[0193] Typically, the modified composition of step (b) can be contacted with silica gel, clays, alkali or alkaline earth metal oxide, iron oxide, ion exchange resins, activated carbon, activated aluminum oxide, molecular sieves, alkali oxide and / or porous supports containing modified or unmodified double lamellar hydroxide and silica gel, or any mixture thereof, to trap silicon and / or metals and / or phosphorus and / or halogenates.

[0194] 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, or even at room temperature, for example chosen from: (i) silica gel, (ii) clay, (iii) crushed clay, (iv) apatite, (v) hydroxyapatite and their combinations, (vi) alumina, for example, alumina obtained by boehmite precipitation, calcined alumina such as Sasol's Ceralox®, (vii) boehmite, (viii) bayerite, (ix) hydrotalcite, (x) spinel such as Sasol's Pural® or Puralox®, (xi) promoted alumina, for example, BASF's Selexsorb®, acid-promoted alumina, alumina promoted by a zeolite and / or by a metal such as Ni, Co, Mo, or a combination of at least two among 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, 4A, 5A, 13X sieves,for example marketed under the brand name Siliporite ® by Ceca, (xiv) a zeolite, (xv) an activated charcoal, or the , 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.

[0195] 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, for example from ambient temperature to 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.

[0196] The purification step (iii) 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 suitable reactor or device.

[0197] Detailed description of the optional catalytic hydrotreating step (d)

[0198] The hydrotreating in step (d) can be carried out in one step or in two steps. When carried out in one step, the product obtained from the separate contact in step (b), optionally purified in 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 bar, preferably 30 to 100 bar, and in the presence of at least one hydrotreating catalyst, for example a NiMo (0.1-60 wt.%) and / or CoMo (0.1-60 wt.%) type catalyst, generally on a support.

[0199] Alternatively, the hydrotreating of step (d) can be carried out in a first step (d-1) in which the product from the separate contacting in step (b), optionally purified in 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 bar, preferably 20 to 50 bar, and in the presence of at least one 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% 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 250 to 340°C in the presence of hydrogen at an absolute pressure of 20 to 160 bar, preferably 30 to 100 bar and in the presence of at least one second hydrotreating catalyst, for example a NiMo (0.1-60% by weight) and / or CoMo (0.1-60% by weight) type catalyst.

[0200] When carried out in two steps, the first hydrotreating step 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 hydrotreating step is typically at least 10%, preferably of at least 25%, measured according to UOP 326. In the second step, a catalyst known to hydrogenate olefins and convert the sulfur and nitrogen components into H2S and NH3 respectively may be advantageously used.

[0201] During the first step, the composition may pass through one or more catalytic beds, preferably with an overall temperature increase of at most 150°C, preferably at most 100°C, and / or a temperature increase of at most 100°C, preferably at most 50°C, for each catalytic bed. Advantageously, an intermediate quenching step may be provided between the catalytic beds, preferably carried out with H2 or with the hydrotreated composition recovered in step (d). This first 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 at least one metal from groups 8-10, preferably chosen from the Pt, Pd, Ni group and / or mixtures thereof on a support such as alumina, titanium, silica, zirconia, magnesia, carbon and / or mixtures thereof.For example, a passivated Ni-based catalyst will be used after its reduction, preferably using a di-alkyl sulfide such as Dimethyl Sulfide (DMS) or Diethyl Sulfide (DES), or thiophenic compounds. It may also be a catalyst comprising at least one metal from group 6, such as Mo, W, in combination or not with a promoter chosen from at least one metal from groups 8-10, such as Ni and / or Co, and / or a mixture thereof, these metals being used in sulfide form and preferably supported on alumina, titanium, zirconia, silica, carbon and / or mixtures thereof.

[0202] During the second step, the composition may pass through one or more catalytic beds, preferably with an overall temperature increase of no more than 100°C, and / or a temperature increase of no more than 50°C on each catalytic bed. Advantageously, an intermediate quenching step 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.This may be a catalyst comprising a hydrogenating function, namely at least one metal from group 6 such as Mo, W, in combination or not with a promoter chosen from at least one metal from groups 8-10 such as Ni and / or Co, and / or a mixture thereof, these metals preferably being used in sulfide form and supported on alumina, titanium, zirconia, silica, carbon and / or mixtures thereof. The catalyst may also have a trapping function and for this purpose have a BET surface area of ​​150 m² / g to 400 m² / g.

[0203] Guard reactors may also be provided to remove any chlorine, metals, and silicon that may still be present. A silicon trap may be provided (for example, at the inlet of the hydrotreating stage or at the inlet of the second hydrotreating 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 water activity (Wh) of 1 to 10 h-l, and / or at an absolute pressure of 10 to 160 bar in the presence of H2; optionally with a metal trap operating at a temperature of at least 200°C, at a water activity (Wh) of 1 to 10 h-l, and at an absolute pressure of 10 to 160 bar in the presence of H2.

[0204] Thus, in general, step (d) can be carried out in a single reactor with several catalytic beds connected in series with possibly additional hydrogen between the beds or in several reactors in series depending on the objective sought.

[0205] This hydrotreating step can also have a demetallization, cracking, dearomatization function depending on the characteristics of the catalyst and the hydrotreating conditions.

[0206] The feedstock for hydrotreating, containing at least a portion of the product obtained from the separate contact in step (b), optionally purified in step (c), can advantageously be heated by a heat exchanger which is fed by the effluent from the hydrotreatment (since hydrotreatment is exothermic, the effluent from the hydrotreatment will have a higher temperature than the feed entering the hydrotreatment).

[0207] Preferably, the feed for hydrotreating, containing at least a portion of the product from the separate contact in step (b), optionally purified in step (c), can be diluted with a portion of the hydrotreating effluent, which still has a temperature higher than the desired temperature at the hydrotreating inlet. This at least partial recycling of the hydrotreating effluent allows for the dilution of unsaturated solids present in the purified composition and preheats the feed.

[0208] At the outlet of the hydrotreating step, the concentration of olefins, 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, preferably even at most 0.5 gBr2 / 100g, or even undetectable, measured according to the ASTM D1159 standard.

[0209] Detailed description of the optional washing step

[0210] The effluent exiting the hydrotreatment step (d), namely the hydrotreated purified composition, can be washed with water to remove inorganic compounds such than hydrosulfide, hydrogen chloride and ammonia before being subjected to further treatments.

[0211] Use of the purified composition

[0212] The product resulting from the separate contact in step (b), optionally purified in step (c) and / or hydrotreated in step (d), and optionally washed with water, can be fractionated into usable streams whose cut points are typically chosen according to the subsequent processing. This fractionation is carried out according to distillation temperature ranges, for example, to separate streams such as LPG, gasoline, diesel, heavy fuel oil, and kerosene, which can then be processed in a steam cracker and / or a catalytic cracker and / or a hydrocracker (and then possibly in a steam cracker) and / or 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.

[0213] The product obtained from separate contacting in step (b), optionally purified in step (c) and / or hydrotreated in step (d), optionally washed with water, can also be used diluted, for example mixed with naphtha, diesel or crude oil to obtain a concentration of purified plastic liquefaction oil ranging from 0.01% by weight to a maximum of 50% by weight; 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 next treatment.

[0214] Detailed description of the optional steam cracking step

[0215] The steam cracking step can be carried out on the product obtained from the contacting process, separated in step (b), optionally purified in step (c) and / or hydrotreated in 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 steam cracking furnace technology.

[0216] This steam cracking step makes it possible to produce 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.

[0217] The steam cracking step consists of thermally cracking a mixture of the purified composition and steam in one or more furnaces 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 cracking The carbon-carbon bonds are broken, and unsaturated hydrocarbons with molecules smaller than the feedstock introduced into the reactor(s) are produced. The effluents exiting the reactor(s) are 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 effluents are then fractionated to recover light C2-C5 olefins, such as ethylene, propylene, butadiene, isobutene, n-butene, and isoprene.

[0218] The product obtained from the separate contacting in step (b), optionally purified in step (c) and / or hydrotreated in step (d), and optionally washed with water, can be sent to the steam cracker undiluted or can be mixed with naphtha, diesel fuel, or crude oil to obtain a purified plastic liquefaction oil concentration ranging from 0.01% by weight to a maximum of 50% by weight; preferably from 0.1% by weight to 25% by weight, and even more preferably from 1% by weight to 20% by weight at the steam cracker inlet. The diluted purified composition is then converted into olefins, such as ethylene and propylene, as well as aromatics.

[0219] In a preferred embodiment, the product from the separate contacting in step (b), optionally purified in step (c) and / or hydrotreated in step (d), optionally washed with water, can be sent at least partially directly into a steam cracker without any dilution other than the steam used for the 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.

[0220] 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).

[0221] 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.

[0222] 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.

[0223] 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 seconds.

[0224] 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.

[0225] 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-to-feedstock ratio can be maintained at a level sufficient to limit coke formation.

[0226] Since the purified 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 composition can then be preheated to a temperature at least 10 °C below the decomposition temperature and subsequently separated from the hydrocarbon vapors produced by the 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.

[0227] Detailed description of the optional hydrocracking step

[0228] Prior to the steam cracking step, the product obtained from the contacting separated in step (b), optionally purified in step (c) and / or hydrotreated in 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.

[0229] 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*.

[0230] A usable hydrocracking catalyst includes, for example, a support selected 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 selected from chromium, molybdenum and tungsten, alone or in mixture, and / or at least one metal from groups 8-10 selected from iron, cobalt, nickel, ruthenium, rhodium, palladium and platinum.

[0231] 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

[0232] [Fig-1] [Fig.1] describes one possible embodiment of the invention. In this In a possible embodiment, the plastic liquefaction oil composition (1) is first optionally pretreated in a pretreatment section (SI) by (i) filtration, (ii) washing with a polar solvent, (iii) distillation, (iv) decantation, or (v) a combination of two, three, or four of steps (i) to (iv). The pretreated composition (2) is then sent to a treatment section (A) for basic microwave irradiation treatment (TTbase) according to step (a) of the invention. The treatment can be carried out in an enclosure comprising one or more microwave generators, and optionally waveguides, for example, of the type described with reference to the process.

[0233] The effluent (3) exiting this treatment section (A) can then be sent to an optional solids separation section (S2), or directly to a separation section (B) to carry out step (b) TTsep, for example by washing and / or distillation. Section (B) can thus include a washing section and / or a distillation section to carry out one or more of steps (i) to (ii) as described by reference to the process.

[0234] The effluent (5), exiting the TTsep step, can then be sent to a second optional solids separation section (S3), or be sent directly to a purification section (C) to implement step (c), or be sent directly to an optional hydrotreatment section (D) to implement an HDT hydrotreatment step corresponding to step (d) of the invention.

[0235] The effluent (7) exiting the hydrotreatment section (D), possibly 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 hydro cracker, an optional section of treatment (S-FCC) in a fluidized bed catalytic cracker, an optional preparation section (S-Pool) of a fuel, lubricant, or base oil. In a preferred embodiment, the effluent (7) exiting the hydrotreating section (D) is then steam cracked to obtain olefins that can subsequently be polymerized. In another preferred embodiment, the effluent exiting the hydrocracking section (S-HC) is then steam cracked to obtain olefins that can subsequently be polymerized.

Claims

Demands

1. A process for purifying a composition comprising a plastic liquefaction oil containing at least 20 ppm by mass of heteroatoms including silicon, comprising: (a) contacting said composition with a basic medium consisting of a basic compound in a polar solvent selected from (i) water, (ii) a polar solvent comprising an alcohol and / or an ether function, and mixtures thereof, and irradiating the reaction medium with microwaves under conditions effective in heating the basic medium to a temperature at most equal to its boiling point at the pressure applied, (b) separating the basic compound from the product obtained from contacting said composition.

2. A process according to claim 1, characterized in that said composition comprises at least one of the following characteristics: - 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, preferably at most 600°C, preferably further at most 560°C, preferably at most 450°C, preferably further at most 350°C, preferably 250°C, - said plastic liquefaction oil contains more than 2 ppm by weight of metals, - 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,preferably not more than 5000 ppm by weight of Si, and / or at least 1 ppm by weight of Si, preferably not more than 1000 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, preferably not more than 5000 ppm by weight, and / or at least 1 ppm by weight of P, preferably not more than 5000 ppm by weight relative to the total weight of said plastic liquefaction oil, - prior to step (a), said composition is subjected to (i) filtration, (ii) washing with water or a polar solvent immiscible with the composition, (iii) distillation, (iv) decantation, or (v) a combination of two, three or four of steps (i) to (iv).

3. A process according to claim 1 or 2, characterized in that step (a) comprises one or more of the following features: - step (a) is carried out in the presence of 0.1 to 50% by mass of basic compound relative to the total mass of said composition, preferably from 0.1 to 15% by mass, more preferably from 1 to 15% by mass, even more preferably from 1 to 10% by mass, - the mass ratio of basic medium to composition is 0.1 / 99.9 to 80 / 20, preferably from 1 / 99 to 60 / 40, more preferably from 5 / 85 to 50 / 50, even more preferably from 10 / 90 to 45 / 55, - the basic compound is selected from LiOH, NaOH, CsOH, Ba(OH)2, Na2O, KOH, K2O, CaO, Ca(OH)2, MgO, Mg(OH)2, NH4OH, TMAOH, TEAOH, TBAOH, MeONA, EtONA and their mixtures, - contact is made for a duration of 1 minute to 48 hours, preferably from 5 minutes to 2 hours, more preferably from 5 minutes to 1 hour, - the polar solvent is chosen from (i) water,(ii) alcohols in the C4 to C1 groups, preferably methanol, ethanol, propan-1-ol, propan-2-ol, butan-1-ol, butan-2-ol, 2-methylpropan-1-ol, ethylene glycol, propylene glycol, (iii) alcohols comprising an ether function, preferably glycol ethers such as polyethylene glycol, polypropylene glycol, tetraethylene glycol, diethylene glycol, triethylene glycol, (iv) cyclic ethers, preferably tetrahydrofuran, 2-methyltetrahydrofuran, tetrahydropyran, 1,4-dioxane, and mixtures thereof, - contact is carried out at an absolute pressure of 0.1 to 100 bar, preferably 1 to 50 bar.

4. A method according to any one of claims 1 to 3, characterized in that the contact is made continuously in a reaction zone in which the basic medium and the composition flow in co-current or counter-current, the basic medium being introduced in the form of droplets.

5. A method according to any one of claims 1 to 3, characterized in that the contact is made in a reaction zone in which the basic medium forms a lower phase and the composition forms an upper phase, and microwaves irradiate the basic medium from a position above the lower phase.

6. A method according to any one of claims 1 to 5, characterized in that, during contacting, the reaction medium or a reaction contact zone is maintained at a target temperature as a function of an irradiation power and / or an irradiation time.

7. A method according to claim 6, characterized in that the target temperature is chosen in a temperature range from 40 °C to 150 °C.

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

9. A method according to any one of claims 1 to 8, characterized in that the separation of step (b) is carried out by (i) washing with a polar solvent, (ii) distillation, or (iii) by a combination of these steps (i), (ii).

10. A process according to claim 9, characterized in that the washing step (b)(i) is carried out with water at neutral, basic or acidic pH, or with an alcohol.

11. A process according to any one of claims 1 to 10, characterized in that the product obtained from the separate contact in step (b) undergoes a purification step (c) 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.

12. A process according to any one of claims 1 to 11, wherein: (d) the product obtained from separate contacting in step (b), optionally purified in step (c), undergoes catalytic hydrotreatment in one or two steps to provide a purified hydrotreated composition.

13. A process according to claim 12, characterized in that the hydrotreating of step (d): - is carried out in a single step in which the product resulting from the contacting is separated in step (b), optionally purified in step (c),

14.

15. 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 bar, preferably 30 to 100 bar, and in the presence of at least one hydrotreating catalyst, or - is carried out in a first step (d-1) in which the product from the separate contact in step (b), optionally purified in 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 bar, preferably 20 to 50 bar, and in the presence of at least one first hydrotreating 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 bar, preferably 30 to 100 bar, and in the presence of at least one second hydrotreating catalyst. A process according to any one of claims 12 or 13, wherein the hydrotreated composition exiting step (d) is washed with water to remove inorganic compounds such as hydrosulfide, hydrogen chloride, ammonia. A process according to any one of claims 1 to 14, wherein the product obtained from the separate contact in step (b), optionally purified in step (c), or the hydrotreated composition of step (d), optionally washed with water, is: (e) subjected, pure or diluted, optionally after separation into usable streams, to a steam cracking step, and / or, (f) subjected, pure or diluted, optionally after separation into usable streams, to a catalytic fluidized bed cracking step, and / or, (g) subjected, pure or diluted, optionally after separation into usable streams, to a hydrocracking step, and / or, (h) subjected, pure or diluted, optionally after separation into usable streams, to a catalytic hydrogenation step, and / or, (i) used as is or separated into usable streams for the preparation of fuels and combustibles such as LPG, gasoline, diesel, heavy fuel oil and / or for the preparation of lubricants and / or base oils.

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