Method for treating a composition comprising an oil derived from plastic waste

Abstract

The present invention relates to a method for treating a composition comprising a liquefied-plastic oil, said composition containing at least 5 ppm by mass of silicon and / or at least 2 ppm by mass of chlorine as measured according to the ISO20884 standard, said treatment method comprising: a) a step of bringing said composition into contact, under hot conditions, with a strong base; then c) a step of washing with a polar solvent that is immiscible with the product obtained, said polar solvent being chosen from water and a polar organic solvent, and mixtures thereof; then d) a step of mixing the product of the preceding step with a petroleum product comprising at least one petroleum distillation fraction, the mixture obtained comprising between 1% by mass and 98% by mass of the product of the preceding step; then e) a step of catalytic hydrotreatment, in the presence of hydrogen, of the mixture obtained in the preceding step.

Description

[0001] DESCRIPTION

[0002] TITLE: Method for treating a composition comprising an oil from plastic waste

[0003] The present invention relates to a method for treating a composition comprising a liquefied plastic oil, in particular produced from plastic waste.

[0004] Chemical recycling of plastic, for example by pyrolysis, allows the recovery of this type of waste. The material is thermally decomposed to produce a hydrocarbon oil containing various impurities, including compounds comprising metals and / or heteroatoms, such as silicon, chlorine, nitrogen and oxygen.

[0005] It is advantageous to process oils from plastic waste for use as fuel, for example for thermal engines.

[0006] For this purpose, hydrotreatments, or hydrorefining, designate catalytic treatment processes in the presence of hydrogen, preferably hot and / or under pressure. Hydrotreatments make it possible to eliminate numerous impurities such as unsaturated hydrocarbons, metals and compounds comprising heteroatoms. Hydrotreatments are notably part of the known processes for refining petroleum fractions for the production of fuels, as described for example in document WO2014 / 096704.

[0007] However, some impurities present in oils from plastic waste cause deactivation of catalysts used in hydrotreatment and / or operational problems such as fouling and corrosion. These impurities include chlorine and silicon, particularly in the form of siloxanes.

[0008] To refine oils from plastic waste using a conventional hydrotreatment process, it is possible to pre-mix these oils with a petroleum product such as a petroleum distillation cut. This type of process is known as co-processing.

[0009] To limit the deactivation of hydrotreatment catalysts and operational problems in existing processes / units, the quantity of oil mixed with a petroleum product generally does not exceed 1% to 2% by mass. Such a constraint severely limits the prospects for recycling oils from plastic waste. Applications FR 21 04616, FR 21 04617 and FR 21 09395, not yet published, in the name of the Applicant, describe a process for purifying plastic pyrolysis oils prior to a steam cracking step. This purification process makes it possible to drastically reduce the content of compounds comprising heteroatoms and silicon in these oils.

[0010] The present invention aims to feed the oils thus purified into hydrotreatment processes in a mixture with petroleum products.

[0011] For this purpose, the subject of the invention is a treatment method of the aforementioned type, in which: the composition comprising a liquefied plastics oil contains at least 5 ppm by mass of silicon as measured according to the ISO20884 standard and / or at least 2 ppm by mass of chlorine as measured according to the ASTM D7359 standard; and the method comprises the following steps: a) a step of bringing the composition into contact, while hot, with a strong base; then c) a step of washing with a polar solvent immiscible with the product obtained, said polar solvent being chosen from water, a polar organic solvent and mixtures thereof; then d) a step of mixing the product of the preceding step with a petroleum product comprising at least one petroleum distillation fraction, the mixture obtained comprising between 1% by mass and 98% by mass of the product of the preceding step; then e) a step of catalytic hydrotreatment, in the presence of hydrogen, of the mixture obtained in the preceding step.

[0012] In this description, the term "liquefied plastic oil" refers to liquid products obtained from the processing of thermoplastic, thermosetting or elastomeric polymers, alone or in a mixture and generally in the form of waste. The processing is, for example, pyrolysis or HTL (HydroThermal Liquefaction) processing. The plastic processed is, for example, polyethylene, polypropylene, polystyrene, a polyester, a polyamide, a polycarbonate or their mixtures.

[0013] Pyrolysis is a thermal cracking process, carried out in the presence or absence of a catalyst.

[0014] The composition of liquefied plastic oil depends on the nature of the plastic being processed and is typically composed of more than 80% by mass of hydrocarbons having 1 to 150 carbon atoms. Liquefied plastic oils contain, in particular, compounds such as paraffins, iso-paraffins, dienes, alkynes, olefins, naphthenes and aromatics. Liquefied plastic oils also contain impurities such as chlorinated, oxygenated and / or silylated organic compounds, metals, salts, phosphorus, sulfur and nitrogen compounds.

[0015] According to an advantageous embodiment, the composition comprising a liquefied plastics oil comprises at least 25% by mass of liquefied plastics oil, preferably at least 50% by mass of liquefied plastics oil, more preferably at least 90% by mass of liquefied plastics oil. According to a particular embodiment, the composition comprises only a liquefied plastics oil.

[0016] According to an advantageous embodiment, the composition comprising a liquefied plastics oil further comprises an oil derived from biomass. Said oil derived from biomass is for example chosen from: a Panicum virgatum oil, a tall oil (from paper mills), a used edible oil, an animal fat, a vegetable oil such as rapeseed oil, canola oil, castor oil, palm oil, soybean oil, an oil extracted from an algae, an oil extracted from a fermentation of oleaginous microorganisms such as oleaginous yeasts, a biomass pyrolysis oil such as a lignocellulosic biomass such as a wood, paper and / or cardboard pyrolysis oil, an oil obtained by pyrolysis of crushed used furniture, an elastomer pyrolysis oil, for example optionally vulcanized latex or tires, as well as mixtures thereof.

[0017] In the present description, it is considered that the composition subjected to the process of the invention initially contains at least 5 ppm by mass of silicon, as measured according to the ISO20884 standard, and / or at least 2 ppm by mass of chlorine as measured according to the ASTM D7359 standard. Silicon is notably present in liquefied plastic oils in the form of siloxanes, in particular cyclic siloxanes of type D3, D4 and / or D5. Chlorine is notably present in liquefied plastic oils in the form of inorganic chlorine, but also of organic chlorine such as chloroethane, dichloroethane, chlorobenzene or vinyl chloride.

[0018] According to an advantageous embodiment, the strong base of contacting step a) comprises an oxide, a hydroxide, a bicarbonate or an alcoholate of an alkali metal cation or an alkaline earth metal cation, or a hydroxide or bicarbonate of a quaternary ammonium cation, alone or as a mixture. More preferably, the strong base is chosen from LiOH, NaOH, CsOH, Ba(OH)2, Na2O, KOH, K2O, CaO, Ca(OH)2, MgO, Mg(OH)2, NH4OH, TMAOH, TEAOH, TBuOH, MeONa, EtONa and mixtures thereof. Even more preferably, the strong base is chosen from KOH, NaOH and mixtures thereof. Alternatively, the strong base is chosen from Na2O, K2O, CaO, MgO and mixtures thereof with each other and / or with the hydroxide bases mentioned above.

[0019] An example of estimating a minimum amount of strong base to use in step a) will be described later.

[0020] According to an advantageous embodiment, step a) of contacting is carried out at a temperature of at least 85°C, preferably at least 100°C, more preferably at least 150°C, even more preferably at least 180°C.

[0021] Preferably, step a) of contacting is carried out at a pressure of between 1 bar and 50 bars, more preferably between 1 bar and 30 bars, even more preferably between 1 bar and 25 bars.

[0022] The duration of step a) of contacting is preferably at least 1 minute, more preferably between 5 minutes and 2 hours, even more preferably between 10 minutes and 1 hour.

[0023] According to a first advantageous embodiment, step a) of contacting is carried out in the presence of water. Preferably, step a) is carried out in the presence of a concentrated aqueous solution of the strong base, more preferably in the presence of a saturated aqueous solution of the strong base.

[0024] According to a second advantageous embodiment, step a) of contacting is carried out in the presence of a polar organic solvent comprising an alcohol function and / or an ether function. Preferably, said polar organic solvent is chosen from (i) C1 to C4 alcohols, preferably from methanol, ethanol, propan-1-ol, propan-2-ol, butan-1-ol, butan-2-ol, 2-methylpropan-1-ol, ethylene glycol, propylene glycol, (ii) alcohols comprising an ether function, preferably diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol and (iii) cyclic ethers, preferably tetrahydrofuran, 2-methyltetrahydrofuran, cyclopentylmethylether, tetrahydropyran, 1,4-dioxane, eucalyptol; and mixtures thereof.

[0025] The term “polar organic solvent” within the meaning of this description covers all chemical species, alone or in a mixture, capable of solvating a composition comprising a liquefied plastic oil, and comprising at least one carbon-hydrogen, carbon-halogen, carbon-chalcogen or carbon-nitrogen covalent bond and having a non-zero dipole moment.

[0026] According to a third advantageous embodiment, the strong base of step a) of contacting is in solid form, for example in the form of soda pellets.

[0027] According to one embodiment, the treatment method comprises, between steps a) and c), a step b) of separating the composition from the strong base. Said separation step b) is carried out by any methods known to those skilled in the art, including centrifugation, decantation, filtration or by the combination of these methods.

[0028] Preferably, in the case of implementation of the treatment process in a reactor, the strong base recovered in step b) is recycled to the top of said reactor for step a).

[0029] In the first and second advantageous embodiments described above for step a), the separation step b) makes it possible to separate a first liquid phase called oily, corresponding to the product resulting from step a), and a second liquid phase containing the majority of the strong base. According to the third advantageous embodiment described above for step a), the separation step b) makes it possible to separate a liquid phase, corresponding to the product resulting from step a), and a solid phase, comprising the majority of the strong base.

[0030] According to an alternative embodiment, the mixture formed by the composition and the strong base in step a) is directly subjected to washing step c). The omission of step b) is, for example, advantageous in the case of a quantity of strong base chosen in slight excess compared to the minimum quantity, the method of calculation of which is described later.

[0031] In the present description, in particular concerning the washing step c), it is considered that a polar solvent is immiscible with the product resulting from step b) when its recovery rate is greater than or equal to 0.95. The recovery rate is defined as the ratio of the volume of extract to the volume of initial solvent, this extract being a phase containing the solvent, immiscible with the composition containing a liquefied plastic oil, recovered after stirring then decanting a mixture of one part by volume of solvent with twenty-five parts by volume of the composition containing a liquefied plastic oil to be purified, at atmospheric pressure and at a temperature of 20°C. A method for determining the recovery rate is for example described in the application FR2109395 cited above.

[0032] According to an embodiment in which the polar solvent of washing step c) comprises a polar organic solvent, said polar organic solvent is advantageously chosen from (i) glycol ethers, including in particular polyethylene glycol of chemical formula HO-(CH2-CH2-O) n -H with a mass average molar mass of 90 to 800g / mol, for example diethylene glycol and tetraethylene glycol, polypropylene glycol with the chemical formula H[OCH(CH3)CH2] nOH of mass average molar mass of 130 to 800g / mol, for example dipropylene glycol and tetrapropylene glycol, (ii) dialkyl formamides, in which the alkyl group may comprise from 1 to 8 or from 1 to 3 carbon atoms, in particular / V, / V-dimethyl formamide (DMF), (iii) dialkyl sulfoxides, in which the alkyl group may comprise from 1 to 8 or from 1 to 3 carbon atoms, in particular dimethyl sulfoxide (DMSO) and sulfolane, (iv) compounds comprising a furan ring, (v) cyclic carbonate esters, in particular comprising from 3 to 8 or from 3 to 4 carbon atoms, in particular propylene carbonate and ethylene carbonate; and mixtures thereof.

[0033] According to an advantageous embodiment, the polar solvent of washing step c) is water at neutral pH (pH=7) or acidic pH (pH<7). Preferably, said water does not contain any base and in particular any hydroxide base. The acidic pH of the water is for example obtained by adding one or more organic or inorganic acids. Examples of organic acids that can be used include citric acid (CeHsO?), formic acid (CH2O2), acetic acid (CH3COOH), sulfamic acid (H3NSO3). Examples of inorganic acids are hydrochloric acid (HCl), nitric acid (HNO3), sulfuric acid (H2SO4), phosphoric acid (H3PO4).

[0034] According to an advantageous embodiment, during washing step c), a polar solvent / composition volume ratio is between 10 / 90 and 90 / 10, preferably between 20 / 80 and 80 / 20, more preferably between 30 / 70 and 70 / 30, even more preferably between 40 / 60 and 60 / 40.

[0035] According to an advantageous embodiment, washing step c) is carried out at a temperature between 0°C and 120°C, preferably between 10°C and 90°C, more preferably at room temperature.

[0036] Preferably, washing step c) is carried out at a pressure of between 1 bar and 50 bars, more preferably between 1 bar and 30 bars, more preferably between 1 bar and 10 bars, even more preferably at atmospheric pressure.

[0037] Washing step c) is carried out, for example, by stirring the product from step a) or b) and the washing solvent in the same container, or by countercurrent circulation. The duration of step c) is preferably at least 1 minute, more preferably between 1 minute and 10 minutes.

[0038] Advantageously, washing step c) is repeated several times, for example two or three times, with identical or different solvents.

[0039] Steps a) to c) make it possible to significantly reduce the silicon and / or chlorine content of the composition comprising the liquefied plastic oil. In particular, according to numerous experimental results, the silicon content of the composition resulting from step c) is less than 2 ppm by mass, for an initial value of between 9 ppm and 150 ppm. According to one embodiment, before mixing step d), the product resulting from washing step c) is subjected to an additional step of drying on an adsorbent such as NasSC and / or distillation and / or any other means for extracting free water.

[0040] In mixing step d), the product from washing step c) is mixed with a petroleum product comprising at least one petroleum cut, i.e. at least one petroleum distillation fraction. Preferably, the petroleum product consists of one or more petroleum distillation fractions.

[0041] Said one or more petroleum distillation fractions are preferably chosen from the following cuts or mixtures of cuts, characterized by their start and end distillation temperatures. Said temperatures, given for information purposes, correspond to distillation at atmospheric pressure:

[0042] - a naphtha / gasoline cut, the start of distillation temperature of which is less than 45°C and the end of distillation temperature is between 145°C and 180°C;

[0043] - a naphtha / gasoline-LPG cut, comprising a naphtha cut as defined above and further comprising C3 and C4 alkanes, such as propane and butane;

[0044] - a kerosene cut, the start of distillation temperature of which is between 145°C and 180°C and the end of distillation temperature is between 240°C and 300°C;

[0045] - a diesel cut, the start of distillation temperature of which is between 225°C and 250°C and the end of distillation temperature is between 360°C and 380°C;

[0046] - a mixed kerosene-diesel cut, with a distillation start temperature between 145°C and 180°C and a distillation end temperature between 360°C and 380°C;

[0047] - an atmospheric residue, which includes distillation products at temperatures greater than or equal to 360°C.

[0048] Preferably, the petroleum product introduced in step d) comprises only one of the cuts or mixtures of cuts described above, and not several of these cuts or mixtures of cuts.

[0049] According to an advantageous embodiment, the product from step c) undergoes a distillation step f) before being mixed in step d) with a petroleum product. Distillation step f) is carried out with start and end distillation temperatures close to the start and end distillation temperatures of the petroleum product from step d). Preferably, the start and end distillation temperatures of step f) are equal to the start and end distillation temperatures of the petroleum product.

[0050] The mixture produced in step d) comprises between 1% by mass and 98% by mass of the product from the previous step, i.e. step c) or f). The percentage by mass of the product obtained in said step c) or f) in the mixture obtained in step d) is preferably at least 3%, more preferably at least 5%, more preferably at least 10%, more preferably at least 15% and even more preferably at least 20%.

[0051] In the case where the product of step c) has not undergone distillation step f) before being mixed with the petroleum product, said distillation may be carried out on the mixture of step d) before carrying out step e).

[0052] Indeed, as will be described below, the characteristics of implementation of step e) of catalytic hydrotreatment depend preferentially on the characteristics of the petroleum product introduced in step d), in particular its start and end distillation temperatures.

[0053] Step e) is a hydrotreatment or hydrorefining step of the mixture obtained in the previous step. Hydrotreatment step e) is a catalytic treatment step in the presence of hydrogen or dihydrogen (H2), of the mixture obtained in step d), said mixture having optionally then been distilled, as indicated above.

[0054] More specifically, step e) is a hydrotreatment step aimed at removing all or part of the sulfur, nitrogen, oxygen compounds, and other impurities present in the mixture obtained in step d). Hydrotreatment includes, among other things, hydrodesulfurization (or HDS), hydrodenitrogenation (or HDN), hydrodeoxygenation (HDO), hydrogenation (HYD), hydrodearomatization or hydrodemetalation (HDM) reactions.

[0055] Hydrotreatment step e) is preferably carried out in a reactor, which is considered in the following description.

[0056] The hydrotreatment catalysts used are preferably supported catalysts comprising an oxide support and at least one hydrogenating function. Such catalysts are known from the state of the art.

[0057] Preferably, these catalysts may be catalysts containing at least one element from group VIB (Cr, Mo, W) and / or one element from group VIII (Fe, Ru, Os, Co, Rh, Ir, Pd, Ni, Pt). More preferably, these catalysts are sulfur-type catalysts containing at least one element from group VIB (Cr, Mo, W) and / or one element from group VIII (Fe, Co, Ni).

[0058] Preferably, the catalyst of step e) comprises a sulfur-type catalyst based on cobalt-molybdenum C0M0 and / or nickel-molybdenum NiMo and / or NiW, or a mixture of these catalysts.

[0059] The oxide support is for example chosen from the group consisting of alumina, silica, silica-aluminas, zirconia, titanium oxide, clays and mixtures of at least two of these minerals. Advantageously, this support may contain other doping compounds, such as boron, phosphorus, or a mixture of these dopants.

[0060] Preferably, step e) is carried out hot and / or under pressure. In particular, step e) is carried out at a temperature of between 200°C and 450°C, preferably between 250 and 420°C, more preferably between 250°C and 400°C; and at an absolute pressure of between 5 and 200 bars, preferably between 5 and 80 bars, more preferably between 20 and 60 bars.

[0061] The space velocity of the feedstock, called LHSV, which is defined as the volumetric flow rate of liquid hydrocarbon feedstock divided by the total volume of catalyst, can be between 0.5 and 5 h' 1 , preferably 1 to 4 hours -1 The quantity of hydrogen mixed with the charge, defined as the ratio between the volumetric flow rate of hydrogen measured under normal temperature and pressure conditions by the volumetric flow rate of liquid hydrocarbon charge, can be between 100 and 1600 Nm 3 / m 3, preferably between 100 and 800 Nm 3 / m 3 , more preferably between 200 and 600 Nm 3 / m 3 .

[0062] For example, step e) is carried out in a fixed-bed reactor, comprising one or more catalytic beds, each bed comprising at least one hydrotreatment catalyst. The reactor is fed on the one hand with a stream of the mixture obtained in step d), and on the other hand with a hydrogen-rich gas stream, in a similar manner to the hydrodesulfurization step described in document WO2014 / 096704.

[0063] Optionally, one or more pretreatment steps or sections may be used upstream of the hydrodesulfurization (HDS). This or these pretreatment steps, called hydrodemetallization (HDM), aim to eliminate the majority of the metals from the feedstock or other impurities by using one or more hydrodemetallization catalysts. To do this, a succession of catalysts with different porosity between the HDM section and the HDS section may be used, making it possible to optimize at each step the accessibility of the active phase, the porosity and the active phase content, in a manner similar to that described in document US2006 / 0060509 for example. In this case, the HDM catalysts used are preferably catalysts known to those skilled in the art.They generally comprise a Group VIB metal component, preferably molybdenum, on a porous oxide support, generally alumina used alone or in admixture with other oxides such as silicon, titanium or zirconia. The catalyst may also contain or not contain a Group VIII metal component, preferably nickel and / or cobalt, for reasons of economy and performance, preferably nickel. The hydrodemetallization catalyst may contain limited amounts of other ingredients known to those skilled in the art, such as phosphorus, boron, alkali metal components and alkaline earth metal components.The porosity of the support of the catalysts considered can then either be a broad average pore distribution or a bimodal pore distribution combining mesopores allowing the surface area to be maximized and macropores allowing the diffusion of large molecules, as described in patents US7119045 or EP1060794.

[0064] Alternatively, demetallation reactions in the presence of hydrogen are carried out in separate reactors, before hydrotreatment step e).

[0065] Preferably, the implementation characteristics of the catalytic hydrotreatment step e) depend on the characteristics of the petroleum product introduced in step d). In particular, step e) is preferably carried out on known catalytic hydrotreatment units, intended for the refining of specific petroleum cuts or specific mixtures such as the naphtha / gasoline, naphtha / gasoline-LPG, kerosene, diesel, kerosene-diesel and atmospheric residue cuts described above.

[0066] It is therefore preferable that the petroleum product introduced in step d) contains only one of these cuts or mixtures of cuts. Similarly, it is preferable that the composition mixed in step d) with said petroleum product has previously undergone distillation step f), or alternatively that the mixture obtained in step d) is distilled before step e) with the appropriate start and end distillation temperatures.

[0067] The low silicon and chlorine content of the product obtained in step c) makes it possible to carry out the mixture of step d) with a significant proportion of liquefied plastic oil, without impacting the hydrotreatment catalyst(s) during step e).

[0068] The product obtained at the end of step e) is intended to be used as fuel. According to one embodiment, said product of step e) is then subjected to an additivation step suitable for said use as fuel. Additives such as corrosion inhibitors, antioxidants, antifoaming agents, demulsifiers and / or chelating agents are for example added to the product of step e).

[0069] The process described above thus allows efficient recycling of liquefied plastic oils, among other things in the form of fuel.

[0070] Examples of embodiments of the invention

[0071] Embodiments of the present invention are illustrated by the following non-limiting examples. Example 1: Calculation of a minimum amount of strong base to be brought into contact with the liquefied plastic oil composition in step a)

[0072] A minimum quantity of strong base to be used in step a) can be estimated in particular as follows:

[0073] Let a be the mass percentage of oxygen and let b, c and d be the respective contents in parts per million for nitrogen, chlorine and silicon, in the composition to be treated.

[0074] Let A, B, C and D be the respective molar masses of oxygen, nitrogen, chlorine and silicon.

[0075] Let M be the molar mass of the strong base to be used (approximately 40 g / mol for sodium hydroxide) and m a percentage linked to the consumption of strong base.

[0076] This latter value is calculated as follows: m = [% + (% + 7c + %)■ 10-4 ] x M

[0077] Assuming that not all heteroatoms react with the strong base, as may be the case with a carboxylic acid which will consume one equivalent of base for every two oxygen atoms, the minimum mass concentration of base a is calculated as follows: a = exm where £ is a factor being at least equal to 0.5.

[0078] Example 2: Purification of a plastic pyrolysis oil in the presence of a strong base and water followed by washing with water

[0079] The physicochemical characteristics of the plastic pyrolysis oil used are described in Table 1, below:

[0080] [Table 1] Table 1 Test protocol:

[0081] A 1.5 L AISI-316L grade stainless steel autoclave equipped with mechanical stirring is charged with HPP4 pyrolysis oil, a strong base in the form of NaOH and water, the strong base being solubilized in water before its introduction into the autoclave (Table 2). The sum of the volume of pyrolysis oil and the volume of water introduced is approximately 600 mL at room temperature, without taking into account the possible effects of volume variation during their mixing. The autoclave is closed and the gaseous headspace in the autoclave is flushed with nitrogen for 30 minutes. The autoclave is then heated under autogenous pressure with stirring at a speed of 400 to 1500 rpm to a temperature of 225 °C for a period of 30 minutes, once the target temperature has been reached. The heating rate is set at 30 °C / 10 minutes.

[0082] [Table 2] Table 2

[0083] After the reaction, the autoclave was cooled to room temperature and then the mixture was discharged and washed three times with water, each time with a water / feed volume ratio of 40 / 60, to remove strong base residues and water-soluble impurities. The resulting purified and washed pyrolysis oil was analyzed for residual impurity content (Table 3). [Table 3] Table 3

[0084] The data in Table 3 show that the use of soda in the presence of water followed by washing makes it possible to significantly reduce the impurities initially contained in the pyrolysis oil as well as the sodium introduced by the soda treatment.

[0085] The pyrolysis oil is either used as is or optionally dried over an adsorbent such as a molecular sieve or an anhydrous salt, e.g. NasSC, and then distilled under reduced pressure to remove any possible traces of solids, e.g. strong base, adsorbent residue, anhydrous / hydrated salt or gums.

[0086] Example 3: Mixture of the product of example 2 with a petroleum product

[0087] We consider a petroleum product of the SGRO (Straight Run Gas Oil) type with the following characteristics (Table 4): [Table 4] Table 4

[0088] The silicon and chlorine contents of SGRO are considered negligible.

[0089] The mixtures below are considered of said SGRO with the product from step 2 (treated HPP4) or with the initial untreated HPP4 (HPP4), according to their silicon and chlorine levels (Table 5). The mixtures are expressed as a mass percentage of HPP4, treated or not. The "HDS Specification" column corresponds to the maximum admissible values ​​of silicon and chlorine levels in a product, before passing through an industrial catalytic hydrodesulfurization reactor:

[0090] [Table 5] Table 5

[0091] The treatment process according to the invention of HPP4 oil allows it to be introduced at a rate of 10% by mass in a mixture with SGRO, while satisfying the requirements for the catalytic hydrodesulfurization step.

[0092] On the contrary, in the absence of treatment according to the invention, the 10% HPP4 mixture exceeds the specifications for silicon and chlorine, and the 2% HPP4 mixture exceeds the specifications for chlorine.

[0093] The treatment method according to the invention therefore makes it possible to increase the quantity of oil from plastic recycling in mixtures with petroleum products, in particular intended to produce fuels.

Claims

CLAIMS 1. A method of treating a composition comprising a liquefied plastics oil, said composition containing at least 5 ppm by mass of silicon as measured according to the ISO20884 standard, and / or at least 2 ppm by mass of chlorine as measured according to the ASTM D7359 standard, said treatment method comprising: a) a step of bringing said composition into contact, while hot, with a strong base; then c) a step of washing with a polar solvent immiscible with the product obtained, said polar solvent being chosen from water, a polar organic solvent and mixtures thereof; then d) a step of mixing the product of the preceding step with a petroleum product comprising at least one petroleum distillation fraction, the mixture obtained comprising between 1% by mass and 98% by mass of the product of the preceding step; then e) a step of catalytic hydrotreatment, in the presence of hydrogen, of the mixture obtained in the preceding step.

2. Treatment method according to claim 1, wherein the strong base of step a) comprises an oxide, a hydroxide, a bicarbonate or an alcoholate of an alkali metal cation or an alkaline earth metal cation, or a hydroxide or a bicarbonate of a quaternary ammonium cation, alone or as a mixture.

3. Treatment method according to claim 1 or claim 2, comprising, before step c), a step b) of separating the composition from the strong base.

4. Treatment method according to one of the preceding claims, in which the polar solvent of step c) is water at neutral or acidic pH.

5. Treatment method according to one of the preceding claims, in which step a) is carried out in the presence of water, preferably in the presence of a concentrated aqueous solution of the strong base, more preferably in the presence of a saturated aqueous solution of the strong base.

6. Treatment method according to one of claims 1 to 4, in which step a) is carried out in the presence of a polar organic solvent comprising an alcohol function and / or an ether function.

7. Method according to one of claims 1 to 4, in which the strong base of step a) is in solid form.

8. Treatment method according to one of the preceding claims, in which step a) is carried out at a temperature of at least 85°C, preferably at least 100°C, more preferably at least 150°C, even more preferably at least 180°C.

9. Treatment method according to one of the preceding claims, in which: the petroleum product from mixing step d) is characterized by distillation start and end temperatures; and before mixing step d), the product obtained in step c) undergoes a distillation step f), with distillation start and end temperatures similar to the distillation start and end temperatures of said petroleum product.

10. Treatment method according to one of the preceding claims, in which the mixture obtained in step d) comprises at least 3% by mass, preferably at least 5% by mass, more preferably at least 10% by mass, more preferably at least 15% by mass, even more preferably at least 20% by mass, of the product obtained in the previous step.

11. Treatment method according to one of the preceding claims, in which the composition comprising a liquefied plastic oil further comprises a biomass oil.

12. Treatment method according to one of the preceding claims, then comprising a step of adding additives to the product obtained in step e) of catalytic hydrotreatment, so as to make said product suitable for use as fuel.

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