Process for purifying hydrocarbon feedstock in aqueous medium and use

Abstract

A purification process for a composition comprising a plastic pyrolysis oil includes treatment with a strong base in the presence of water followed by washing with water. The process is useful for reducing the concentration of heteroatoms, and in particular alkali and alkaline earth metal cations, in said composition in order to make it compatible for introduction as a feedstock in conversion processes such as steam cracking, catalytic fluid bed cracking, catalytic hydrogenation, or hydrocracking, notably without deactivating catalysts used in these processes.

Description

Title of the invention: Process for purifying hydrocarbon feedstock in aqueous medium and use Technical field of the invention

[0001] The present invention relates to a process for purifying hydrocarbon feedstock and its subsequent use in refining and petrochemical processes. The process according to the invention makes it possible to purify feedstocks containing plastic pyrolysis oils, in particular with a view to their use in a steam cracking process. Technological background

[0002] Patent JP3776335 discloses a process for dechlorination and denitrogenation of an oil from the catalytic or thermal cracking of plastic waste which is treated at different temperatures up to 425°C for 30 minutes in the presence of an aqueous solution of an alkaline compound of an alkali or alkaline earth metal at a pH greater than or equal to 7. All non-radioactive natural alkali or alkaline earth metal hydroxides are tested. The reaction product is then separated from the alkaline aqueous solution by liquid-liquid separation with ethyl ether.

[0003] Patent application WO2012 / 069467 claims a process for removing siloxanes contained in a plastic pyrolysis oil by heat treatment between 200 and 350°C in the presence of an alkali metal hydroxide in solid or solution form. The use of 5% by weight calcium hydroxide at 225°C does not allow a reduction in the siloxane content to be obtained (Table 5, p. 12 and lines 9 to 11, p. 13). At the end of the reaction, the pyrolysis oil is separated by distillation under reduced pressure.

[0004] Patent FI 128848 describes a process sequence comprising a treatment thermal treatment of a plastic pyrolysis oil at at least 200°C in the presence of an alkaline aqueous solution. At the end of the reaction, the pyrolysis oil is separated from the alkaline aqueous phase. A final hydrotreatment makes it possible to obtain a steam cracker feed which is optionally washed with an acid solution before introduction into the steam cracker.

[0005] Patent application WO2020 / 02769 claims a process sequence for purifying a composition comprising at least 20 ppm of chlorine. Many recyclable liquid wastes can be treated, including plastic pyrolysis oils. The process sequence comprises a thermal treatment of the feedstock in the presence of an alkali metal hydroxide in order to obtain a reduction of at least 50% of the chlorine content relative to the feedstock, followed by hydrotreatment in order to to obtain a further reduction of at least 50% of the chlorine content.

[0006] Patent application WO2021 / 105326 claims a method for recovering liquefied plastic waste comprising a step of pretreating the liquefied plastic waste by contacting it with an aqueous medium having a pH of at least 7 at a temperature of 200°C or higher, followed by a liquid-liquid separation in which the aqueous phase is separated from the organic phase, to produce a pretreated liquefied waste plastic material. The proposed solution comprises the use of a solution of NaOH in water. The separation of the aqueous and organic phases is carried out by physical (centrifugation) or chemical methods (addition of separation aid additives, for example non-aqueous solvents, addition of additional quantity of the aqueous medium used for contacting or of an aqueous medium having a different alkaline substance concentration), or by gravity.

[0007] These documents do not present means for lowering the content of alkali / alkaline earth metals present in the plastic pyrolysis oil after pretreatment with a strong base. However, it is known that the presence of alkali / alkaline earth metals can lead to the deactivation of catalysts used in catalytic processes for treating pretreated plastic pyrolysis oil. Summary of the invention

[0008] The invention aims to propose a method for purifying plastic pyrolysis oil making it possible to facilitate its purification by limiting the quantity of strong base used while maintaining high reduction performance, including for the reduction of the content of alkali and / or alkaline earth metals resulting from the treatment of the plastic pyrolysis oil with a strong base.

[0009] To this end, the invention relates to a method for reducing the heteroatom concentration of a composition comprising a plastic pyrolysis oil containing at least 20 ppm by mass of chlorine as measured according to standard ASTM D7359-18, comprising:

[0010] (a), contacting said composition with 0.1-50% by mass of a base strong comprising an alkali or alkaline earth metal cation in the presence of water, for 1 minute to 20 minutes at a temperature of not more than 450°C,

[0011] (b), washing with water at neutral or acid pH of the product from step (a).

[0012] In particular, step (a) is carried out without adding any solvent other than water or a solvent possibly already present in the composition.

[0013] Advantageously, the strong base added in step a) is in solution in water. Thus, during step (a), the composition may be brought into contact with an aqueous solution of a strong base comprising an alkali or alkaline-earth metal cation. A person skilled in the art will then choose a quantity of water sufficient to dissolve / so- Lubricate the strong base, preferably with the smallest possible amount of water.

[0014] During step (a), the volume ratio of the strong base in solution in water / composition, i.e. the volume ratio of the mixture (strong base + water) / composition, may be from 0.1 / 99.9 to 80 / 20, from 1 / 99 to 80 / 20, from 1 / 99 to 70 / 30, from 1 / 99 to 65 / 35, from 1 / 99 to 60 / 40, from 1 / 99 to 50 / 50, or in any interval defined by any two of the above-mentioned limits.

[0015] The composition may further comprise a biomass pyrolysis oil such as Panicum virgatum, a tall oil, a used edible oil, an animal fat, a vegetable oil such as rapeseed, canola, castor, palm, or 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, and mixtures thereof.

[0016] The composition may comprise at least 2% by mass of a plastic pyrolysis oil. The remainder may then be composed of at most 98% by mass of a diluent or solvent such as a hydrocarbon and / or one or more of the components listed above. In one embodiment, the composition may comprise at least 25% by mass of plastic pyrolysis oil, preferably at least 50% by mass, more preferably 75% by mass, even more preferably at least 90% by mass of plastic pyrolysis oil. It is also possible to use only plastic pyrolysis oil.

[0017] The contacting is preferably carried out for a period of 1 minute to 20 minutes, preferably 1 minute to 16 minutes, at a temperature of 50 to 450°C, preferably 90 to 350°C, more preferably 150 to 350°C and at an absolute pressure of 0.1 to 100 bars, preferably 1 to 50 bars.

[0018] A preferred strong base may be selected from LiOH, NaOH, CsOH, Ba(OH)2, Na2 O, KOH, K2O, CaO, Ca(OH)2, MgO, Mg(OH)2 and mixtures thereof. A more preferred strong base may be selected from NaOH, KOH and mixtures thereof.

[0019] The water used in step (b) may have an acidic pH (PH<7) or neutral pH (pH=7). In particular, the water used does not contain a base and in particular does not contain a strong base comprising an alkali or alkaline-earth metal cation. An acidic pH may be obtained by adding one or more organic or inorganic acids. Examples of organic acids that can be used include citric acid (C6H8O7), 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).

[0020] Step (b) may be carried out at a temperature of 0° to 80°C, for example 0° to 60°C, preferably 0° to 40°C, more preferably 0° to 30°C, in particular without external heating. Step (b) is typically carried out at atmospheric pressure.

[0021] During step (b), the water / composition volume ratio with the strong base may be 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, from 40 / 60 to 60 / 40, or in any interval defined by any two of the aforementioned limits.

[0022] Step (b) may comprise, or consist of, bringing the product from step (a) into contact with water by any means known in the prior art.

[0023] For example, the product from step (a) and the water may be introduced into tanks, reactors or mixers commonly used in the profession and the two components may be mixed. The contacting may comprise vigorous stirring of the two components by a mixing device. For example, the two components may be mixed together by stirring or shaking. Alternatively, the contacting may be carried out in an enclosure in which the two components circulate in countercurrent. This contacting may occur more than once, in particular under the conditions presented above.

[0024] Step (b) can be carried out on the product directly resulting from step (a) (comprising the strong base in solution in water and the product resulting from bringing the composition into contact), without an intermediate step, or on the product resulting from step (a) having undergone a separation step.

[0025] Thus, in one embodiment, the method according to the invention comprises, between step (a) and (b), a step of separation between the strong base comprising the alkali or alkaline-earth metal cation in solution in water and the product resulting from the contacting of said composition. The product resulting from the contacting of said composition corresponds to a composition comprising a plastic pyrolysis oil having a lower heteroatom concentration than the initial composition. It is thus a purified composition.

[0026] The separation between the strong base in solution in water and the product resulting from step (a) is advantageously carried out by (i) centrifugation, (ii) decantation, or (iii) by the combination of these two steps.

[0027] Typically, this separation step makes it possible to separate an organic phase, corresponding to the product resulting from the contacting of step (a), and an aqueous phase containing the strong base comprising the alkali or alkaline-earth metal cation. It may be preceded by a step of separating the solids by (i) filtration, (ii) centrifugation or (iii) a combination of the two steps. This step of separating the solids may make it possible to facilitate the separation of the organic and aqueous phases. by removing all or part of the solids present in the product from step (a).

[0028] Also, advantageously, the strong base in solution in the water separated during this separation step can be returned (recycled), partially or completely, to step (a).

[0029] The separation step makes it possible to reduce part of the alkali or alkaline-earth cation content of the product from step (a). The remaining alkali or alkaline-earth cation content (or all or almost all of the alkali or alkaline-earth cation content when this separation step is absent) is removed during the washing step (b). The composition thus treated can be used without causing deactivation of catalysts used in subsequent catalytic treatment processes.

[0030] Washing step (b) can make it possible to obtain a product having an alkali or alkaline-earth cation content of less than or equal to 2 ppm (by mass).

[0031] The invention may also comprise an additional step prior to step (a) of contacting, in which said composition is subjected, in particular immediately before step (a), to (i) filtration, (ii) washing with a polar solvent, (iii) distillation, (iv) decantation, or (v) the combination of two, three or four of steps (i) to (iv). This preliminary step may make it possible to reduce some of the impurities contained in the composition such as oxygen, nitrogen, chlorine, sulfur or other heteroatoms. In particular, the reduction in the quantity of oxygen may make it possible to avoid the formation of solids and / or gels during step (b).

[0032] During the additional preliminary washing step (ii), the polar solvent / composition volume ratio may be 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, from 40 / 60 to 60 / 40.

[0033] The polar solvent may have a density greater or less than the density of the composition comprising a plastic pyrolysis oil.

[0034] In particular, the density of the polar solvent may be 3 to 50% higher or lower than that of the composition.

[0035] The polar solvent is furthermore a solvent immiscible in the composition comprising a pyrolysis oil to be purified.

[0036] In the present invention, it may be considered that the polar solvent (or a mixture of polar solvents where appropriate) is immiscible when its recovery rate is greater than or equal to 0.95. This recovery rate is defined as the ratio of the volume of extract to the volume of initial solvent, this extract being a phase containing the solvent, immiscible with the composition containing a pyrolysis 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 pyrolysis oil to be purified, at atmospheric pressure and at a temperature of 20°C.

[0037] This recovery rate can be determined in particular by following the following procedure:

[0038] • Introduction of 50 mL of composition containing a pyrolysis oil into a flat-bottomed flask with a volume of 100 mL, using a precision pipette of + / -0.5 mL, • Introduce 2 mL of solvent into the flask, using a precision pipette + / -0.1 mL, • Insert a magnetic bar, close the balloon with a polypropylene stopper, • Stir the mixture on a mechanical stirrer plate at a speed of 500 rpm for 5 min, • At the end of 5 minutes, stop stirring, remove the magnetic bar using a magnetic rod, • Transfer the contents of the flask into a graduated tube with an accuracy of + / -0.05 mL for a volume less than or equal to 2 mL and an accuracy of + / -0.1 mL for a volume greater than 2 mL. Wait for complete demixing by decantation and measure the volume of the 2 phases using the graduations. Complete demixing is considered to be achieved when the volumes of the two phases no longer vary.

[0039] The expression "polar solvent" within the meaning of the present patent application covers all chemical species, alone or in a mixture, capable of solvating a composition comprising a plastic pyrolysis oil, and comprising at least one carbon-hydrogen, carbon-halogen, carbon-chalcogen or carbon-nitrogen covalent bond and having a non-zero dipole moment. The polar solvent may thus contain one or more heteroatoms, in particular chosen from oxygen, sulfur and nitrogen, preferably oxygen.Acceptable polar solvents, immiscible with the composition comprising a pyrolysis oil to be purified, include compositions comprising hydrocarbon compounds which have heteroatoms in their molecular structure, for example (i) alcohols such as methanol and ethanol, and mixtures of alcohols derived from fermentation, for example a mixture of butanol isomers or a mixture of pentanol isomers such as a fusel oil (ii) ethers, for example cyclopentylmethyl ether or 1,4-dioxane, (iii) sulfur compounds, for example thiophene or dimethyl sulfoxide, (iv) nitrogen compounds, for example A / A-dimethylformamide, (v) halogenated compounds, for example dichloromethane or chloroform, or: .

[0040] - water having an acidic, basic or neutral pH. An acidic pH can be obtained by adding one or more organic or inorganic acids. Examples of suitable organic acids include citric acid (C6H8O 7), 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). A basic pH can be obtained by the addition of alkali and alkaline earth metal oxides, alkali and alkaline earth hydroxides (e.g. NaOH, KOH, Ca(OH)2) and amines (e.g. triethylamine, ethylenediamine, ammonia). - glycol ethers, including in particular polyethylene glycol of chemical formula HO-(CH2-CH2-O)nH with a mass average molar mass of 90 to 800g / mol, for example diethylene glycol and tetraethylene glycol, polypropylene glycol of chemical formula H[OCH(CH3)CH2]nOH with a mass average molar mass of 130 to 800g / mol, for example dipropylene glycol and tetrapropylene glycol, - dialkyl formamides, in which the alkyl group may comprise from 1 to 8 or from 1 to 3 carbon atoms, in particular dimethyl formamide (DMF), - dialkyl sulfoxides, in which the alkyl group may comprise from 1 to 8 or from 1 to 3 carbon atoms, in particular dimethyl sulfoxide (DMSO) and sulfolane - compounds comprising a furan ring, - cyclic carbonate esters, comprising in particular from 3 to 8 or from 3 to 4 carbon atoms, in particular propylene carbonate and ethylene carbonate.

[0041] One or more of the above-mentioned solvents may be used. However, advantageously, only one of the above-mentioned solvents may be used provided that it is immiscible with the composition containing a pyrolysis oil to be purified.

[0042] Preferably, the polar solvent may be a glycol ether, in particular polyethylene glycol of chemical formula HO-(CH2-CH2-O)nH with a mass average molar mass of 90 to 800g / mol or polypropylene glycol of chemical formula H[OCH(CH3)CH2]nOH with a mass average molar mass of 130 to 800g / mol, or a compound comprising a furan ring, or a cyclic carbonate ester, in particular propylene or ethylene carbonate, alone or as a mixture, preferably alone.

[0043] In a preferred embodiment, the polar solvent is chosen from propylene carbonate, ethylene carbonate and polyethylene glycol of chemical formula HO-(CH2-CH2-O)nH with a mass average molar mass of 90 to 800g / mol, alone or as a mixture, preferably alone.

[0044] The invention may also comprise an additional step in which:

[0045] (c). the product resulting from the washing of step (b) undergoes catalytic hydrogenation in one or two steps.

[0046] In the case where the catalytic hydrogenation is carried out in two stages, stage (c) is carried out in a first stage (c-1) in which the product resulting from the contacting is hydrogenated at a temperature of between 20 and 200°C, preferably between 30 and 90°C in the presence of hydrogen at an absolute pressure of between 5 and 60 bars, preferably between 20 and 30 bars and in the presence of a hydrogenation catalyst comprising Pd (0.1-10% by weight) and / or Ni (0.1-60% by weight) and / or NiMo (0.1-60% by weight), and in a second stage (c-2) in which the effluent resulting from stage (c-1) is hydrogenated at a temperature of between 200 and 450°C, preferably between 200 and 34 ... between 20 and 140 bars, preferably between 30 and 60 bars and in the presence of a hydrogenation catalyst comprising NiMo (0.1-60% by weight) and / or CoMo (0.1-60% by weight).

[0047] The product from step (b) or the effluent from step (c) is (d) preferably 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.

[0048] The adsorbent may be operated in regenerative or non-regenerative mode, at a temperature below 400°C, preferably below 100°C, more preferably below 60°C, chosen from: (i) a silica gel, (ii) a clay, (iii) a crushed clay, (iv) apatite, (v) hydroxyapatite and combinations thereof, (vi) an alumina, for example an alumina obtained by boehmite precipitation, a calcined alumina such as Ceralox ® from Sasol, (vii) boehmite, (viii) bayerite, (ix) hydrotalcite, (x) a spinel such as Pural ® or Puralox from Sasol, (xi) a promoted alumina, for example Selexsorb ® from BASF, an acid promoted alumina, an alumina promoted by a zeolite and / or by a metal such as Ni, Co, Mo or a combination of at least two of them, (xii) an acid-treated clay such as Tonsil ® from Clariant, (xiii) a molecular sieve in the form of an aluminosilicate containing an alkali or alkaline earth cation for example 3A sieves,4A, 5A, 13X, for example marketed under the brand Siliporite ® from Ceca, (xiv) a zeolite, (xv) an activated carbon, or the combination of at least two adsorbents, the adsorbent or the at least two adsorbents retaining at least 20% by weight, preferably at least 50% by weight of at least one element among F, Cl, Br, I, O, N, S, Se, Si, P, As, Fe, Ca, Na, K, Mg and Hg and / or water.

[0049] According to a preferred embodiment, the adsorbent is regenerable, has a specific surface area of ​​at least 200 m2 / g and is operated in a fixed bed reactor at less than 100°C with a WH of 0.1 to 10 h'.

[0050] According to an additional embodiment, at least a portion of the product from step (b) or the effluent from step (c) or (d) may be:

[0051] (e). treated in a steam cracker, and / or

[0052] (f). treated in a fluidized bed catalytic cracker, and / or

[0053] (g), treated in a hydrocracker, and / or

[0054] (h), treated in a catalytic hydrogenation unit, and / or

[0055] (i). used as is or separated into streams usable for the preparation of fuels and fuels such as LPG, gasoline, diesel, heavy fuel oil and / or for the preparation of lubricants.

[0056] The previously described steps of the method according to the invention can be implemented one after the other without an intermediate step except for the optional additional steps described. Definitions

[0057] Hourly Volume Velocity (WH) is defined as the hourly volume of charge flow per unit of catalytic volume and is expressed here in h *.

[0058] The terms "comprising" and "comprises" as used herein are synonymous with "including," "includes," or "contains," "containing," and are inclusive or unbounded and do not exclude additional features, elements, or method steps not specified.

[0059] The specification of a numeric domain without decimals includes all whole numbers and, where appropriate, fractions thereof (e.g., 1 to 5 may include 1, 2, 3, 4, and 5 when referring to a number of elements, and may also include 1.5, 2, 2.75, and 3.80, when referring to, for example, a measurement.).

[0060] The specification of a decimal also includes the decimal itself (e.g., "from 1.0 to 5.0" includes 1.0 and 5.0). Any range of numeric values ​​recited herein also includes any subrange of numeric values ​​mentioned above.

[0061] 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.

[0062] Unless otherwise indicated, measurements given in parts per million (ppm) are expressed by weight.

[0063] The expression "plastic pyrolysis oil" or "oil resulting from the pyrolysis of plastic" refers to the liquid products obtained at the end of a pyrolysis of thermoplastic, thermosetting or elastomeric polymers, alone or in a mixture and generally in the form of waste. The pyrolysis process must be understood as a thermal cracking process, carried out in the presence or absence of a catalyst (for example, catalytic or non-catalytic fast pyrolysis, etc.). The pyrolyzed plastic can be of any type. For example, the plastic to be pyrolyzed can be polyethylene, polypropylene, polystyrene, a polyester, a polyamide, a poly- carbonate, etc. These plastic pyrolysis oils contain paraffins, i-paraffins (iso-paraffins), dienes, alkynes, olefins, naphthenes and aromatics. Plastic pyrolysis oils also contain impurities such as chlorinated, oxygenated and / or silylated organic compounds, metals, salts, phosphorus, sulfur, and nitrogen compounds.

[0064] The composition of the plastic pyrolysis oil is dependent on the nature of the pyrolyzed plastic and is essentially (in particular at more than 80% m / m, most often at more than 90% m / m) made up of hydrocarbons having from 1 to 150 carbon atoms and impurities.

[0065] The expression "MAV" (acronym for "Maleic Anhydric Value") refers to the UOP326-82 method which is expressed in mg of maleic anhydride which react with 1 g of sample to be measured.

[0066] The term "Bromine Number" refers to the amount of bromine in grams reacted per 100 g of sample and can be measured according to ASTM DI 159-07.

[0067] The term "Bromine Index" is the number of milligrams of bromine that react with 100 g of sample and can be measured according to ASTM D2710 or ASTM D5776 methods.

[0068] Boiling points as mentioned herein are measured at atmospheric pressure, unless otherwise stated. An initial boiling point is defined as the temperature value from which a first vapor bubble is formed. A final boiling point is the highest temperature achievable during a distillation. At this temperature, no more vapor can be transported to a condenser. The determination of the initial and final points uses techniques known in the art and several methods adapted according to the distillation temperature range are applicable, for example NF EN 15199-1 (2020 version) or ASTM D2887 for the measurement of boiling points of petroleum fractions by gas chromatography, ASTM D7169 for heavy hydrocarbons, ASTM D7500, D86 or DI 160 for distillates.

[0069] The concentration of metals in hydrocarbon matrices can be determined by any known method. Acceptable methods include X-ray fluorescence (XRF) and inductively coupled plasma atomic emission spectrometry (ICP-AES). Analytical scientists know how to identify the most suitable method for measuring each metal and heteroelement depending on the hydrocarbon matrix under consideration.

[0070] The particular features, structures, properties, embodiments of the invention may be freely combined into one or more embodiments not specifically described herein, as may be apparent to those skilled in the art. treatment of plastic pyrolysis oils using their general knowledge. Description of the invention Examples

[0071] Embodiments of the present invention are illustrated by the following non-limiting examples.

[0072] Example 1: Purification of a plastic pyrolysis oil in the presence of a base strong and water followed by a water wash

[0073] The physicochemical characteristics of the plastic pyrolysis oil used are described in Table 1, below:

[0074] [Table 1] Table 1 HPP2 Pyrolysis Oil Density (g / mL) 0.800 Kinematic Viscosity (15°C, mm2 / s) 2.1 Distillation, Initial Boiling Point (°C) 69 Distillation, 50% (°C) 214 Distillation, End Boiling Point (°C) 451 Silicon (ppm by mass) 82 Chlorine (ppm by mass) 96 Oxygen (% by mass) 0.87 Nitrogen (ppm by weight) 206

[0075] Test protocol:

[0076] A 1.5 L AISL316L grade stainless steel autoclave equipped with mechanical stirring is charged with HPP2 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 possible effects of volume variation during their mixing. The autoclave is closed and the gaseous headspace in the autoclave is swept 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 1 minute, 10 minutes or 20 minutes depending on the tests, once the target temperature has been reached. The temperature rise rate is set at 30°C / 10 minutes.

[0077] [Table 2] Table 2 Test 1 2 3 Pyrolysis oil HPP2 HPP2 HPP2 Water / charge volume ratio 0.024 0.024 0.024 Temperature (°C) 225 225 225 Time (min) 1 10 20 Water volume (mL) 13.8 13.8 138.0 NaOH mass (g) 14.0 14.0 138.0 Pyrolysis oil mass (g) 467.2 467.2 368.0 Initial pyrolysis oil volume (mL) 584 584 460 NaOH concentration in pyrolysis oil (%m / m) 3 3 3 NaOH concentration in water (%m / m) 50 50 50 Initial density (g / mL) 0.8 0.8 0.8 Final pressure in the autoclave (bars) 10 8 12

[0078] At the end of the reaction, the autoclave is cooled to room temperature and then, for tests 1 and 2, the mixture is discharged and washed three times with water with, at each wash, a water / load volume ratio = 40 / 60, to remove strong base residues and water-soluble impurities. The resulting purified and washed pyrolysis oil is analyzed to measure the residual impurity content (Table 3). For test 3, the mixture discharged from the autoclave is divided into two parts. The first part is washed with water under the same conditions as for tests 1 and 2 and the resulting purified and washed pyrolysis oil is analyzed (test 3A of Table 3). The second part is decanted to recover the organic phase, which is then centrifuged. The resulting decanted and centrifuged pyrolysis oil is analyzed (Test 3B in Table 3).

[0079] [Table 3] Table 3 Test 1 2 3A 3B Initial silicon (ppm weight) 80 80 80 80 Final silicon (ppm weight) <2 <2 <2 <2 Silicon reduction (%) >97 >97 >97 97 Initial chlorine (ppm weight) 115 115 115 115 Final chlorine (ppm weight) 32 24 23 23 Chlorine reduction (%) 72 79 80 80 Initial oxygen (% by weight) 0.90 0.90 0.90 0.90 Final oxygen (% by weight) 0.12 0.13 0.11 0.47 Oxygen reduction (%) 87 86 88 48 Initial nitrogen (ppm by weight) 192 192 192 192 Final nitrogen (ppm by weight) 31 29.8 30.0 43.6 Nitrogen reduction (%) 84 84 84 77 Initial sodium (ppm by weight) <2 <2 2.5 <2 Final sodium (ppm by weight) <2 <2 <2 1536

[0080] 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, even for a short duration of soda treatment.

[0081] In particular, it has been observed that in the absence of washing, for example after simple decantation / centrifugation, the sodium content of the pyrolysis oil is high, in particular greater than 1000 ppm, which is not acceptable for subsequent catalytic treatment.

[0082] The pyrolysis oil can either be used as is or optionally dried on an adsorbent such as a molecular sieve or an anhydrous salt, for example Na2SO4, and then distilled under reduced pressure in order to remove any possible traces of solid, for example strong base, adsorbent residue, anhydrous / hydrated salt or gums.

[0083] Example 2: Two-stage hydrotreatment and steam cracking of the product of Example 1

[0084] One of the purified and washed pyrolysis oils of Example 1 (from Tests 1, 2 or 3A) can be hydrotreated in two stages according to the following procedure:

[0085] The purified and washed pyrolysis oil may be introduced into a first hydrotreatment section (HDT1) primarily to hydrogenate the diolefins and is operated in the liquid phase. This step may comprise a plurality of reactors in series and / or parallel if guard reactors are used upstream or downstream of the first hydrogenation reactor. These guard reactors may make it possible to reduce the concentration of certain undesirable chemical species and / or elements such as chlorine, silicon and metals. Particularly undesirable metals include Na, Ca, Mg, Fe and Hg.

[0086] A second hydrotreatment section (HDT2) is dedicated to the hydrogenation of olefins and demetallization (HDM), desulfurization (HDS), denitrogenation (HDN) and deoxygenation (HDO). HDT2 is operated in the gas phase. This section consists of one or more reactors operated in series, lead-lag or in parallel.

[0087] Since the hydrotreating reactions in sections HDT1 and HDT2 are exothermic, a cold hydrogen quench can be used to moderate the temperature increase and control the reaction.

[0088] Isolated, lead-lag, series and / or parallel guard reactors can be considered depending on the nature and quantity of the contaminant in the flow to be treated.

[0089] In the event that the treatment of Example 1 does not allow sufficient reduction of impurities to be obtained, guard reactors for removing chlorine and silicon can be operated in the gas phase. Silicon can also be trapped on the upper bed of a reactor in section HDT2 or separately, upstream or downstream by the treatment of hot gases leaving section HDT2.

[0090] Chlorine and mercury can be separated by liquid or gas phase guard reactors.

[0091] There may be intermediate quenches between the beds or between the HDT1 and HDT2 reactors or no quenching. In the latter case, recycling of part of the flow leaving HDT1 or HDT2 must be carried out to control the temperature. Strict control of the temperature in HDT1 must be carried out, in order to avoid clogging of the reactor and degradation of the catalytic hydrogenation conditions.

[0092] The operating pressure in each of the hydrotreatments HDT1 and HDT2 is 5-60 bars, preferably 20-30 bars for HDT1 and 20-140 bars, preferably 30-60 bars for HDT2, typically 30-40 bars for HDT2.

[0093] Typical temperature range at the inlet of HDT1 at the start of the cycle (SOR: start of run): 150-200°C. The catalyst for HDT 1 usually comprises Pd (0.1-10% by weight) and / or Ni (0.1-60% by weight) and / or NiMo (0.1-60% by weight).

[0094] Typical temperature range at the inlet of HDT2 at the start of the cycle (SOR: start of run): 200-340°C. Typical temperature range at the outlet of HDT2 (SOR): 300-380°C, up to 450°C. The catalyst for HDT 2 usually comprises a NiMo (any type of commercial catalyst for refining or petrochemical application), potentially a CoMo in the very last beds at the bottom of the reactor (any type of commercial catalyst for refining or petrochemical application).

[0095] The upper bed of the HDT2 should preferably be operated with a NiMo having a hydrogenating capacity as well as a silicon trapping capacity. An upper bed of this type can be considered as an adsorbent as well as a metal trap having also HDN activity and a hydrogenating capacity. An example of an upper bed ac Suitable for this function include commercially available NiMo catalyst adsorbents such as ACT971, ACT981 from Axens or equivalents from Haldor Topsoe, Axens, Criterion, etc. It is possible to have two separate beds in an HDT2 reactor, with quenching between the two beds or between the two reactors, if the two beds are in two separate reactors, or no quenching at all. Ideally, the intermediate quench is carried out using cold HDT2 effluent or by supplying cold hydrogen, i.e. at a temperature typically ranging from 15 to 30°C, in order to control the HDT2 exotherm. Dilution by recycle of the hydrocarbon stream to the upper HDT2 bed is not recommended due to the increased risks of bed fouling. The charge arriving at the HDT2 catalyst should be completely vaporized at all times, including in variable regimes as is the case during start-ups.Sending liquid hydrocarbons to the upper bed of an HDT2 reactor can generate fouling and an increase in the pressure difference between the inlet and outlet of said HDT2 reactor and lead to premature shutdown.

[0096] Depending on the metals present in the pyrolysis oil to be hydrotreated, a hydrodemetallization catalyst, for example commercial, can be added to the upper bed of the HDT2 section in order to protect the lower catalytic beds from deactivation.

[0097] The hydrotreated pyrolysis oil leaving the HDT2 section can be used as is or fractionated according to distillation temperature ranges, to feed a steam cracker, an FCC, a hydrocracker, a catalytic reformer or a pool of fuels or combustibles such as LPG, gasoline, jet, diesel, fuel oil.

[0098] Alternatively, the treated pyrolysis oil leaving section HDT2 undergoes a further purification step by passing over a capture mass such as an adsorbent, for example (i) silica gel, (ii) clay, (iii) crushed clay, (iv) apatite, (v) hydroxyapatite and combinations thereof, (vi) an alumina, for example a boehmite-precipitated alumina, a calcined alumina such as Ceralox ® from Sasol, (vii) boehmite, (viii) bayerite, (ix) hydrotalcite, (x) a spinel such as Pural ® or Puralox from Sasol, (xi) a promoted alumina, for example Selexsorb ® from BASF, an acid-promoted alumina, an alumina promoted by a zeolite and / or by a metal such as Ni, Co, Mo or a combination of at least two of them, (xii) an acid-treated clay such as Tonsil ® from Clariant, (xiii) a molecular sieve in the form of an aluminosilicate containing an alkali or alkaline earth cation, for example sieves 3A, 4A, 5A,13X, for example marketed under the brand Siliporite ® from Ceca, (xiv) a zeolite, (xv) an activated carbon, or the combination of at least two adsorbents, the adsorbent or the at least two adsorbents retaining at least 20% by weight, preferably at least 50% by weight of at least one, element among F, Cl, Br, I, O, N, S, Se, Si, P, As, Fe, Ca, Na, K, Mg and Hg and / or water. Ideally, the adsorbent is regenerable, has a specific surface area of ​​at least 200 m2 / g and is operated in a fixed bed reactor at less than 100°C with a WH of 0.1 to 10 h1.

Claims

Claims

1. A method for reducing the heteroatom concentration of a composition comprising a plastic pyrolysis oil containing at least 20 ppm by mass of chlorine as measured according to ASTM D7359-18, comprising: a. contacting said composition with 0.1-50% by mass of a strong base comprising an alkali or alkaline earth metal cation, in the presence of water, for 1 minute to 20 minutes at a temperature of at most 450°C, b. washing with water at neutral or acidic pH the product resulting from step (a), c. the product resulting from the washing of step (b) undergoes a catalytic hydrogenation in one or two stages.

2. The method of claim 1, wherein the composition further comprises a biomass pyrolysis oil such as Panicum virgatum, tall oil, used edible oil, animal fat, vegetable oil such as rapeseed, canola, castor, palm, soybean oil, oil extracted from algae, oil extracted from fermentation of oleaginous microorganisms such as oleaginous yeasts, biomass pyrolysis oil such as lignocellulosic biomass such as wood, paper and / or cardboard pyrolysis oil, oil obtained by pyrolysis of crushed used furniture, elastomer pyrolysis oil, for example optionally vulcanized latex or tires, and mixtures thereof.

3. Method according to claim 1 or 2, comprising between step (a) and (b) a step of separation between the strong base comprising the alkali or alkaline-earth metal cation in solution in water and the product resulting from the contacting of said composition.

4. A method according to claim 3, wherein the separation step is carried out by (i) centrifugation, (ii) decantation, or (iii) by the combination of these two steps.

5. A method according to claim 3 or 4, wherein the strong base in solution in the water separated during the separation step is returned, partially or completely, to the contacting step (a).

6. A method according to any one of claims 3 to 5, wherein the separation step is preceded by a step of separating the solids by (i) filtration, (ii) centrifugation or (iii) a combination of the two steps.

7. A method according to any one of claims 1 to 6, wherein the contacting is carried out for a period of 1 minute to 20 minutes, preferably 1 minute to 16 minutes, at a temperature of 50 to 450°C, preferably 90 to 350°C, more preferably 150 to 350°C and at an absolute pressure of 0.1 to 100 bars, preferably 1 to 50 bars.

8. A method according to any one of claims 1 to 7, wherein the strong base is selected from LiOH, NaOH, CsOH, Ba(OH)2, Na2O, KOH, K2O, CaO, Ca(OH)2, MgO, Mg(OH)2 and mixtures thereof.

9. A process according to any one of claims 1 to 8, wherein, prior to the contacting of step (a), said composition is subjected to (i) filtration, (ii) washing with a polar solvent, (iii) distillation, (iv) decantation, or (v) the combination of two, three or four of steps (i) to (iv).

10. Process according to any one of claims 1 to 9, in which the catalytic hydrogenation of step (c) is carried out in a first step (c-1) in which the product resulting from the contacting is hydrogenated at a temperature of between 20 and 200°C, preferably between 30 and 90°C in the presence of hydrogen at an absolute pressure of between 5 and 60 bars, preferably between 20 and 30 bars and in the presence of a hydrogenation catalyst comprising Pd (0.1-10% by weight) and / or Ni (0.1-60% by weight) and / or NiMo (0.1-60% by weight), and in a second step (c-2) in which the effluent resulting from step (c-1) is hydrogenated at a temperature of between 200 and 450°C, preferably between 200 and 340°C in the presence of hydrogen at an absolute pressure of between 20 and 140 bars, preferably between 30 and 60 bars and in the presence of a hydrogenation catalyst comprising NiMo (0.1-60% by weight) and / or CoMo (0.1-60% by weight).

11. A process according to any one of claims 1 to 10, wherein the product from step (b) or the effluent from step (c) is (d) 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.

12. A method according to claim 11, wherein the adsorbent is operated in a regenerative or non-regenerative mode, at a temperature below 400°C, preferably less than 100°C, more preferably less than 60°C chosen from: (i) a silica gel, (ii) a clay, (iii) a crushed clay, (iv) apatite, (v) hydroxyapatite and combinations thereof, (vi) an alumina, for example an alumina obtained by boehmite precipitation, a calcined alumina such as Ceralox ® from Sasol, (vii) boehmite, (viii) bayerite, (ix) hydrotalcite, (x) a spinel such as Pural ® or Puralox from Sasol, (xi) a promoted alumina, for example Selexsorb ® from BASF, an acid promoted alumina, an alumina promoted by a zeolite and / or by a metal such as Ni, Co, Mo or a combination of at least two of them, (xii) a acid-treated clay such as Tonsil ® from Clariant, (xiii) a molecular sieve in the form of an aluminosilicate containing an alkali or alkaline earth cation, for example sieves 3A, 4A, 5A, 13X, for example marketed under the brand name Siliporite ® from Ceca, (xiv) a zeolite,(xv) an activated carbon, or the combination of at least two adsorbents, the adsorbent or the at least two adsorbents retaining at least 20% by weight, preferably at least 50% by weight of at least one element among F, Cl, Br, I, O, N, S, Se, Si, P, As, Fe, Ca, Na, K, Mg and Hg and / or water.,

13. A method according to claim 12, wherein the adsorbent is regenerable, has a specific surface area of ​​at least 200 m2 / g and is operated in a fixed bed reactor at less than 100°C with a WH of 0.1 to 10 hi

14. A process according to any one of claims 1 to 13, wherein at least a portion of the product from step (b) or of the effluent from step (c) or (d) is: (e) treated in a steam cracker, and / or (f) treated in a fluidized bed catalytic cracker, and / or (g) treated in a hydrocracker, and / or (h) treated in a catalytic hydrogenation unit, and / or (i) used as such or separated into streams suitable for the preparation of fuels and combustibles such as LPG, gasoline, diesel, heavy fuel oil and / or for the preparation of lubricants.