Process for pyrolyzing polyolefin recovered from solid material comprising said polyolefin

Abstract

The invention relates to a process for pyrolyzing a polyolefin recovered from a solid material M containing said polyolefin, to a production plant for carrying out said process, to a pyrolysis oil obtainable or obtained by said process and to the use of said pyrolysis oil.

Description

[0001] The present invention relates to a method for pyrolyzing the polyolefins recovered from a solid material M containing polyolefins and a production apparatus for carrying out the method. The present invention further relates to the pyrolysis oil obtainable or obtained by the foregoing method and the use of said oil.

[0002] Polyolefins such as polyethylene (PE) and polypropylene (PP) can be seen in many materials such as packaging and plastics from automobiles. Therefore, their consumption accounts for a large percentage of the global CO 2 emissions. Therefore, there is a need to recycle polyolefins from such materials. Polyolefins can be chemically recycled by pyrolysis. However, when the waste stream contains a small amount of polyolefins, non-olefin plastics form less of a lower-quality liquid product. Therefore, the product yield of by-products (light gases and solid residues) increases. In addition, these by-products also have a lower quality. For example, the light gases may consist of CO, CO 2 , methane, and ethane, which are contaminated with undesirable components such as acidic gases like HCl, NOx, HCN, etc., and / or the solid residues may contain a large amount of rare earth metals, PAHs, etc. Therefore, the solid residues must be landfilled or incinerated. Due to the presence of polyamides, polyurethanes, polyesters, and polyethers, the pyrolysis oil obtained from such materials generally becomes increasingly oxygen-rich and / or nitrogen-rich, which leads to an increased workload for purification after pyrolysis. These heteroatoms must be removed by hydrogenation reactions in a laborious manner during hydrotreating. Even pre-hydrogenation may be required to consume dienes, styrenes, and chlorine before any hydrotreating is possible. In addition, in the presence of silicones in the waste stream, it is known that the siloxanes formed during pyrolysis interfere with hydrotreating and are also undesirable in steam crackers or in partial oxidation (POX). For example, US2019 / 0322832 A1 relates to a method for recovering polymer and hydrocarbon mixtures from sorted waste feedstock or waste mixtures. The method therein relies on an extraction process that uses a non-polar solvent for extracting polymers from polymer blends, and then reverses the solvent polarity by adding the non-polar solvent-solvated extract to a more polar solvent in order to precipitate the product. However, there is still a need to provide an improved method for recycling polyolefins contained in solid materials such as waste plastic materials.

[0003] Surprisingly, it has been found that the method of the present invention exhibits better yields and is more cost-effective. In fact, the method of the present invention allows for the simplification of the entire polyolefin recycling process, which allows for cost reduction. Therefore, using the method for pyrolyzing the polyolefins recovered from a solid material containing polyolefins according to the present invention allows for a reduction in the CO 2 footprint.

[0004] Therefore, the present invention relates to a method for pyrolyzing the polyolefins recovered from a solid material M containing polyolefins, the method comprising

[0005] (i) Provide a liquid stream S containing a polyolefin dissolved in a non-polar solvent P , comprising:

[0006] (i.1) Provide a solid material M containing a polyolefin;

[0007] (i.2) Provide a liquid stream S comprising a non-polar solvent LS , wherein 80 wt%-100 wt% of S LS consists of a non-polar solvent, and wherein S LS has a temperature T SLS <T ES , T ES is the boiling temperature of the non-polar solvent;

[0008] (i.3) Contact the solid material M provided according to (i.1) with the liquid stream S provided according to (i.2) LS in a reactor unit R D at a temperature T D and a pressure p D , wherein T D <T ES , thereby obtaining a liquid stream S containing a polyolefin dissolved in a non-polar solvent P ;

[0009] (ii) Feed the liquid stream S containing a polyolefin dissolved in a non-polar solvent provided according to (i) P into a solid-liquid separation unit SLU, thereby obtaining a liquid stream S containing a polyolefin dissolved in a non-polar solvent SLU ;

[0010] (iii) Subject the liquid stream S containing a polyolefin dissolved in a non-polar solvent obtained according to (ii) SLU to precipitation conditions, thereby obtaining a solid mixture containing precipitated polyolefin P P ;

[0011] (iv) Subject the solid mixture containing precipitated polyolefin P P obtained according to (iii) to pyrolysis conditions in a pyrolysis reactor R P , thereby obtaining pyrolysis oil O P .

[0012] One of the advantages of the method according to the invention is that the hydrogenation of the obtained pyrolysis oil is not necessary, or the workload of hydrogenation is reduced due to the low concentration of atoms other than carbon or hydrogen. In addition, pretreatment of the polyolefin before pyrolysis is not necessarily required, such as heat treatment to remove PVC, additional washing steps or pre-pyrolysis. Similarly, since the amount of gas is small and the amounts of components such as NOx, sulfur components, halogenated components (HCl, HBr, halogenated hydrocarbons, cyanic acid, CO, CO 2 ) are reduced, the treatment of the gas phase before release into the environment is reduced. Therefore, the method according to the invention is more efficient because it simplifies the recycling of polyolefins and is more cost-effective compared to known methods.

[0013] As described above, the method for pyrolyzing the polyolefin recovered from the solid material M containing polyolefin according to the invention comprises

[0014] (i) providing a liquid stream S containing polyolefin dissolved in a non-polar solvent P , comprising:

[0015] (i.1) providing a solid material M containing polyolefin;

[0016] (i.2) providing a liquid stream S comprising a non-polar solvent LS , wherein 80 wt%-100 wt% of S LS consists of a non-polar solvent, and wherein S LS has a temperature T SLS <T ES , T ES being the boiling temperature of the non-polar solvent;

[0017] (i.3) contacting the solid material M provided according to (i.1) with the liquid stream S provided according to (i.2) LS in a reactor unit R D at a temperature T D and a pressure p D , wherein T D <T ES , thereby obtaining a liquid stream S containing polyolefin dissolved in a non-polar solvent P ;

[0018] (ii) feeding the liquid stream S containing polyolefin dissolved in a non-polar solvent provided according to (i) P into a solid-liquid separation unit SLU, thereby obtaining a liquid stream S containing polyolefin dissolved in a non-polar solvent SLU ;

[0019] (iii) subjecting the liquid stream S containing polyolefin dissolved in a non-polar solvent obtained according to (ii) SLUSubject to precipitation conditions to obtain a solid mixture containing precipitated polyolefin P P ;

[0020] (iv) Subjecting the solid mixture containing precipitated polyolefin P obtained according to (iii) P to pyrolysis conditions in a pyrolysis reactor R P to obtain pyrolysis oil O P .

[0021] Preferably, the polyolefin is selected from the group consisting of: polyethylene (PE), polypropylene (PP), polymethylpentene (PMP), polybutene-1 (PB-1), ethylene-octene copolymer, stereoblock PP, olefin block copolymer, propylene-butane copolymer, polyisobutylene (PIB), ethylene-propylene rubber (EPR), ethylene-propylene-diene monomer rubber (M-class rubber) (EPDM rubber), and mixtures of two or more thereof. More preferably, it is selected from the group consisting of: polyethylene, polypropylene, and mixtures of polyethylene and polypropylene.

[0022] In the context of the present invention, the polyolefin may preferably be a mixture of the same polyolefin, i.e., a mixture of PE or PP, or a mixture of two or more different polyolefins, such as a mixture of PE and PP.

[0023] Preferably, providing the solid material M containing the polyolefin according to (i.1) includes shredding the solid material M containing the polyolefin in a shredding unit US1.

[0024] Preferably, 90 wt%-100 wt%, more preferably 95 wt%-100 wt%, more preferably 99 wt%-100 wt%, more preferably 99.5 wt%-100 wt% of S provided in (i.2) LS consists of a non-polar solvent. In other words, the liquid stream S provided in (i.2) LS preferably consists essentially of a non-polar solvent, and more preferably consists of a non-polar solvent.

[0025] Preferably, the non-polar solvent is selected from the group consisting of: xylene, toluene, n-heptane, amyl acetate, n-amyl acetate, isobutyl acetate, n-propyl propionate, n-butyl propionate, heptan-2-one, methyl-cyclohexane, cyclohexane, and mixtures of two or more thereof. More preferably, it is selected from the group consisting of: xylene, toluene, amyl acetate, cyclohexane, and mixtures of two or more thereof. More preferably, it is xylene.

[0026] Preferably, (i) includes providing a liquid stream S containing a polyolefin dissolved in a non-polar solvent P .

[0027] Preferably, the non-polar solvent is a single solvent selected from the group consisting of xylene, toluene, n-heptane, amyl acetate, n-amyl acetate, isobutyl acetate, n-propyl propionate, n-butyl propionate, heptan-2-one, methyl-cyclohexane, and cyclohexane. More preferably, the non-polar solvent is a single solvent selected from the group consisting of xylene, toluene, amyl acetate, and cyclohexane. Even more preferably, the non-polar solvent is xylene.

[0028] The present invention provides several improvements to systems such as those described in US2019 / 0322832 A1. More specifically, the method of the present invention has an improved polymer extraction and separation method, which is carried out by: using a non-polar solvent to extract the desired polymer preferably at a high temperature, and then precipitating (e.g., by cooling) the desired polyolefin from a supersaturated solution of a single solvent. Without wishing to be bound by any theory, this method allows for the simplification of the entire process (including solvent recycling) and the equipment required to carry out the process on a continuous large scale, while reducing energy consumption compared to the prior art.

[0029] In the context of the present invention, the term "xylene" refers to all isomers of xylene and mixtures thereof, preferably a mixture of ortho-xylene, meta-xylene, and para-xylene isomers.

[0030] Preferably, the method for pyrolyzing the polyolefin recovered from the solid material M containing polyolefin according to the present invention comprises

[0031] (i) providing a liquid stream S containing polyolefin dissolved in a non-polar solvent P , including:

[0032] (i.1) providing a solid material M containing polyolefin;

[0033] (i.2) providing a liquid stream S containing a non-polar solvent LS , wherein 80 wt%-100 wt% of S LS consists of a non-polar solvent, and wherein S LS has a temperature T SLS < T ES , T ES being the boiling temperature of the non-polar solvent;

[0034] (i.3) contacting the solid material M provided according to (i.1) with the liquid stream S provided according to (i.2) LS in a reactor unit R D at a temperature T D and a pressure p D such that T D < T ES, thereby obtaining a liquid stream S containing polyolefin dissolved in a non-polar solvent P ;

[0035] (ii) Feeding the liquid stream S containing polyolefin dissolved in a non-polar solvent provided according to (i) P to a solid-liquid separation unit SLU, thereby obtaining a liquid stream S containing polyolefin dissolved in a non-polar solvent SLU ;

[0036] (iii) Subjecting the liquid stream S containing polyolefin dissolved in a non-polar solvent obtained according to (ii) SLU to precipitation conditions, thereby obtaining a solid mixture containing precipitated polyolefin P P ;

[0037] (iv) Subjecting the solid mixture containing precipitated polyolefin P obtained according to (iii) P to pyrolysis conditions in a pyrolysis reactor R P , thereby obtaining pyrolysis oil O P ;

[0038] wherein the non-polar solvent is selected from the group consisting of: xylene, toluene, n-heptane, amyl acetate, n-amyl acetate, isobutyl acetate, n-propyl propionate, n-butyl propionate, heptan-2-one, methyl-cyclohexane and cyclohexane.

[0039] Preferably, the non-polar solvent has a Hansen solubility parameter δ 1 / 2 in the range of 0 to 10 MPa, more preferably in the range of 0 to 8 MPa 1 / 2 , more preferably in the range of 0 to 7 MPa 1 / 2 . H

[0040] In the context of the present invention, the Hansen solubility parameter δ H is a known parameter characterizing the solubility of a compound. δ H relates to the energy from hydrogen bonds between molecules. For many compounds, such as xylene, toluene and cyclohexane, the Hansen parameter δ H can be found in standard chemical books. The Hansen solubility parameter δ H mentioned in the present invention refers to the values listed in: Hansen, C.M., Hansen Solubility Parameters - A user’s handbook, 2nd Edition, CRC Press, Boca Raton, USA, 2007.

[0041] Preferably, according to (i), no solvent other than the non-polar solvent is involved in the dissolution.

[0042] Preferably, the solid material M provided according to (i.1) contains waste, more preferably consists of waste, wherein the waste more preferably contains plastic waste.

[0043] In the context of the present invention, the term "plastic waste" or "mixed plastic waste" refers to plastic waste containing different types of plastic articles. Usually, plastics are sorted before being processed / recycled, such that plastic waste can be just plastic bags or plastic foils to be processed or recycled. The sorting can be done in advance by different companies. However, in the context of the present invention, there is no such requirement for pre-sorting, and the mixed plastic waste or plastic waste is municipal plastic waste as obtained from households, such as a mixture of plastic bags, plastic packaging, plastic pipes, etc. According to the present invention, high-quality oil can be directly formed from these plastic wastes.

[0044] Preferably, 5 wt%-99 wt%, more preferably 20 wt%-98.5 wt%, more preferably 30 wt%-98 wt%, more preferably 40 wt%-98 wt% of M consists of polyolefins.

[0045] Preferably, in addition to polyolefins, the solid material M contains one or more of the following: polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyurethane (PU), paper, aluminum, and polyamide.

[0046] Preferably, based on the weight of the solid material M in kg, the solid material M has a Cl content of at most 25000 mg / kg, more preferably in the range of 1500 to 15000 mg / kg, more preferably in the range of 1500 to 12000 mg / kg, and the Cl content is determined as described in Analysis 3.

[0047] Preferably, based on the weight of the solid material M, the solid material M has an N content of at most 5 wt%, more preferably in the range of 0.55 wt% to 3 wt%, and the N content is determined as described in Analysis 3.

[0048] Preferably, based on the weight of the solid material M, the solid material M has an O content of at most 20 wt%, more preferably in the range of 4 wt% to 15 wt%, and the O content is determined as described in Analysis 3.

[0049] Preferably, based on the weight of the solid material M, the solid material M has an S content of at most 1000 wppm, more preferably in the range of 0 to 800 wppm, more preferably in the range of 0 to 500 wppm, and the S content is determined as described in Analysis 3.

[0050] Preferably, based on the weight of the solid material M, the solid material M has a Si content in the range of 300 to 15000 wppm, more preferably in the range of 300 to 14500 wppm, and this Si content is determined as described in Analysis 3.

[0051] Preferably, T SLS is in the range of 55 °C to 150 °C, more preferably in the range of 60 °C to 140 °C.

[0052] Preferably, T D is in the range of 55 °C to 150 °C, more preferably in the range of 60 °C to 140 °C.

[0053] Preferably, p D is in the range of 800 to 200000 hPa, more preferably in the range of 800 to 10000 hPa.

[0054] The present invention provides several improvements to systems such as those described in US2019 / 0322832 A1. More specifically, the method of the present invention has an improved polymer extraction and separation method, which is carried out as follows: using a non-polar solvent at a high temperature (i.e., preferably 55 °C to 150 °C) to extract the desired polymer, and then obtaining these polymers by precipitating the desired polyolefin from a supersaturated solution of a single non-polar solvent (e.g., by cooling). This method simplifies the entire process (including solvent recycling) and the equipment required to carry out this process on a continuous large scale, while reducing energy consumption compared to methods known in the art.

[0055] Preferably, before (i.3), the solid material M containing polyolefin is fed into the reactor unit R via gravity or pneumatic conveying D therein.

[0056] Preferably, in the reactor unit R D the weight ratio of the solid material M to the non-polar solvent is in the range of 1:1 to 1:20, more preferably in the range of 1:3 to 1:15, even more preferably in the range of 1:4 to 1:12.

[0057] Preferably, (i.3) includes

[0058] bringing the solid material M provided according to (i.1) into contact and mixing with the liquid stream S provided according to (i.2) LS in the reactor unit R D at a temperature T D and a pressure p D and preferably stirring, where T D <T ES so as to obtain a liquid stream S containing polyolefin dissolved in the non-polar solventP 。

[0059] Preferably, the reactor unit R D comprises z chemical reactors R Di , where i = 1... z, and z ranges from 1 to 5, more preferably from 1 to 3.

[0060] Preferably, when z > 1, at least two reactors R Di are arranged in parallel, and more preferably z reactors R Di are arranged in parallel.

[0061] Preferably, the temperature T of the z reactors R Di is maintained by heating the contents thereof, and more preferably by passing a heating medium through the heating jacket of R Di to keep the temperature T of the z reactors R Di therein. Di 。

[0062] It is also conceivable to directly heat the reactor, for example, by using a heater below the reactor R Di .

[0063] Preferably, the method further comprises, before (ii),

[0064] maintaining the temperature T of the liquid stream S containing polyolefin dissolved in a non-polar solvent obtained according to (i.3) P such that 50 °C < T SP < T SP < T ES 。

[0065] Preferably, the temperature T is substantially maintained, more preferably maintained, via one or more heating tubes for transferring the liquid stream S P to the SLU. SP 。

[0066] Preferably, the solid-liquid separation unit SLU is a filtration unit F1, more preferably a stirred pressure filter, and the filtration unit F1 more preferably has a mesh size in the range of 1 to 100 microns, more preferably in the range of 1 to 20 microns.

[0067] Alternatively, the solid-liquid separation can be accomplished by sedimentation or centrifugation (see Handbuch der mechanischen Fest-Flüssig-Trennung Taschenbuch [Handbook of Mechanical Solid-Liquid Separation]

[0068] - April 2004, Klaus Luckert (editor).

[0069] Preferably, the filtration unit F1 comprises a filter for blocking solid contaminants and a receiving container for a liquid stream S of polyolefin dissolved in a non-polar solvent; wherein these solid contaminants include one or more of polymers other than polyolefin, polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyurethane (PU), and polyamide (PA). SLU The solid contaminants include one or more of polymers other than polyolefin, polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyurethane (PU), and polyamide (PA).

[0070] Preferably, the filtration unit F1 operates at a pressure p F where p F ≥ 1 bar (absolute), more preferably p F is in the range of 1 to 30 bar (absolute), more preferably in the range of 1 to 10 bar (absolute), more preferably in the range of 1 to 6 bar (absolute).

[0071] More preferably, when the non-polar solvent is xylene, p F is in the range of 2 to 4 bar (absolute), more preferably in the range of 2.5 to 3.5 bar (absolute), and T SP is in the range of 110 °C to 130 °C.

[0072] Preferably, (iii) comprises

[0073] (iii.1) subjecting the liquid stream S of polyolefin dissolved in a non-polar solvent obtained according to (ii) to precipitation at a temperature T SLU and a pressure p P where T P < T P and T D < 100 °C, thereby obtaining a solid mixture comprising precipitated polyolefin P P P P of the solid mixture.

[0074] More preferably, (iii.1) comprises

[0075] cooling the liquid stream S of polyolefin dissolved in a non-polar solvent at a temperature T P and a pressure p P for precipitation, where T SLU < T P and T D < 100 °C, thereby obtaining a stream P of polyolefin precipitated in a non-polar solvent. P P

[0076] Preferably, T P < T D ≤ -5 °C, more preferably T P ≤ T D ≤ -10 °C, more preferably T P ≤ T D-30 °C, more preferably T P <T D -30 °C.

[0077] Preferably, the cooling according to (iii.1) comprises

[0078] (iii.1.a) transferring a cooling medium to a cooling jacket of a receiving vessel of the filtration unit containing S SLU ; or

[0079] (iii.1.b) allowing the liquid stream S SLU to stand in the receiving vessel of the filtration unit.

[0080] Preferably, the cooling rate is in the range of 2 to 200 K / h, more preferably in the range of 3 to 150 K / h, and even more preferably 20 to 120 K / h.

[0081] Alternatively, (iii) comprises

[0082] (iii.1’) subjecting the liquid stream S containing polyolefin dissolved in a non-polar solvent obtained according to (ii) to precipitation by contacting the SLU with a polar solvent, thereby obtaining a stream P containing polyolefin precipitated in the polar solvent and the non-polar solvent. SLU

[0083] Preferably, the contacting of the SLU with the polar solvent is carried out at a temperature in the range of 10 °C to 120 °C, more preferably in the range of 20 °C to 60 °C.

[0084] Preferably, the contacting of the SLU with the polar solvent is carried out at a pressure in the range of 0 to 10 bar (absolute), more preferably in the range of 0.5 to 2 bar (absolute).

[0085] Preferably, the polar solvent is selected from the group consisting of water, ethanol, methanol, propanol, butanol, acetone, dimethyl sulfoxide, acetonitrile, dimethylformamide, ethyl acetate, sulfolane, dichloromethane, tetrahydrofuran, and mixtures of two or more thereof, more preferably selected from the group consisting of water, acetone, ethanol, methanol, and mixtures of two or more thereof.

[0086] Preferably, the polar solvent has a Hansen solubility parameter δ greater than 5 MPa 1 / 2 , preferably in the range of 6 to 50 MPa 1 / 2 , more preferably in the range of 10 to 30 MPa 1 / 2 range. H .

[0087] Preferably, (iii) comprises

[0088] ​(iii.1) Subject the liquid stream S containing polyolefin dissolved in a non-polar solvent obtained according to (ii) SLU to precipitation at a temperature T P and a pressure p P wherein T P < T D and T P < 100 °C, thereby obtaining a solid mixture containing precipitated polyolefin P P More preferably, cool the liquid stream S containing polyolefin dissolved in a non-polar solvent at a temperature T P and a pressure p P to effect precipitation, wherein T SLU < T P and T D < 100 °C, thereby obtaining a stream P containing polyolefin precipitated in the non-polar solvent; or P

[0089] (iii.1') Subject the liquid stream S containing polyolefin dissolved in a non-polar solvent obtained according to (ii) to precipitation by contacting SLU with a polar solvent, thereby obtaining a stream P containing polyolefin precipitated in the polar solvent and the non-polar solvent; (iii.1') Subject the liquid stream S containing polyolefin dissolved in a non-polar solvent obtained according to (ii) to precipitation by contacting SLU with a polar solvent, thereby obtaining a stream P containing polyolefin precipitated in the polar solvent and the non-polar solvent; SLU Subject the liquid stream S containing polyolefin dissolved in a non-polar solvent obtained according to (ii) to precipitation by contacting SLU with a polar solvent, thereby obtaining a stream P containing polyolefin precipitated in the polar solvent and the non-polar solvent;

[0090] (iii.2) Transfer the stream P obtained according to (iii.1) or (iii.1'), more preferably (iii.1), to a filtration unit F2, thereby obtaining a solid mixture containing precipitated polyolefin P P separated from the non-polar solvent and the polar solvent (when applicable);

[0091] (iii.3) Optionally wash the solid mixture containing precipitated polyolefin obtained according to (iii.2), more preferably wash the solid mixture with one or more of methanol, ethanol, propanol, isopropanol, acetonitrile, ethyl acetate, acetone, and water;

[0092] (iii.4) Optionally dry the solid mixture containing the washed precipitated polyolefin obtained according to (iii.3).

[0093] Preferably, (iii) further comprises

[0094] (iii.5) Recycling at least a portion of the non-polar solvent obtained according to (iii.2) as a component of the liquid stream S in (i.2) LS ;

[0095] wherein more preferably (iii.5) comprises

[0096] (iii.5.1) Transfer at least a portion of the non-polar solvent obtained according to (iii.2) to distillation unit D to obtain a purified non-polar solvent;

[0097] (iii.5.1) Add the purified non-polar solvent obtained according to (iii.5.1) to the liquid stream S in (i.2) LS therein.

[0098] Preferably, distillation unit D is heated by a heating source, more preferably steam. Such a heating source is preferably generated by a recycled gas stream obtained after pyrolysis.

[0099] Preferably, if (iii.1') is carried out, then (iii.5) further comprises recycling the polar solvent, more preferably in (iii.1'). Recycling the polar solvent more preferably comprises

[0100] (iii.5.3) Transfer at least a portion of the polar solvent obtained according to (iii.2) to distillation unit D' to obtain a purified polar solvent;

[0101] (iii.5.4) Add the purified polar solvent obtained according to (iii.5.3) in (iii.1').

[0102] It is also conceivable to use the same column to recycle both solvents (i.e., polar and non-polar solvents) by fractional distillation.

[0103] Preferably, the precipitated polyolefin is in the form of flakes, the flakes having an average size in the range of 0.05 to 10 cm, more preferably in the range of 0.1 to 5 cm, more preferably in the range of 0.1 to 2 cm, and the average size of the flakes being determined as defined in Reference Example 1.

[0104] Preferably, based on the weight of the precipitated polyolefin in kg, the precipitated polyolefin has a Cl content of at most 600 mg / kg, more preferably in the range of 0 to 5000 mg / kg, more preferably in the range of 0 to 2000 mg / kg, and the Cl content being determined as described in Analysis 3.2.

[0105] Preferably, based on the weight of the precipitated polyolefin, the precipitated polyolefin has an N content of at most 2 wt-%, more preferably at most 1 wt-%, more preferably at most 0.5 wt-%, and the N content being determined as described in Analysis 3.2.

[0106] Preferably, based on the weight of the precipitated polyolefin, the precipitated polyolefin has an O content of at most 2 wt-%, more preferably at most 1 wt-%, more preferably at most 0.5 wt-%, and the O content being determined as described in Analysis 3.2.

[0107] Preferably, based on the weight of the precipitated polyolefin, the precipitated polyolefin has an S content of at most 1000 wppm, more preferably in the range of 0 to 800 wppm, and even more preferably in the range of 0 to 500 wppm, and the S content is determined as described in Analysis 3.2.

[0108] Preferably, based on the weight of the precipitated polyolefin, the precipitated polyolefin has an Si content of at most 300 wppm, more preferably in the range of 0 to 200 wppm, even more preferably in the range of 0 to 100 wppm, and even more preferably in the range of 0 to 70 wppm, and the Si content is determined as described in Analysis 3.2.

[0109] Optionally, (iii) further comprises

[0110] (iii.6) pulverizing the dry solid mixture containing the precipitated polyolefin obtained according to (iii.4) in a pulverizing unit US2 into flakes, which flakes have an average size in the range of 0.05 to 10 cm, more preferably in the range of 0.1 to 5 cm, and even more preferably in the range of 0.1 to 2 cm, and the average flake size is determined as defined in Reference Example 1.

[0111] Preferably, the flakes obtained according to (iii.6) have an average thickness in the range of 0.01 to 5 cm, more preferably in the range of 0.1 to 2 cm. Figure 2 Flakes of the precipitated polyolefin are shown.

[0112] Preferably, the solid mixture obtained according to (iii) contains an amount of precipitated olefin in the range of 90 wt-% to 100 wt-%, more preferably in the range of 95 wt-% to 100 wt-%, based on the weight of the solid mixture.

[0113] Preferably, according to (iii), no solvent other than the non-polar solvent is involved in the precipitation conditions.

[0114] Preferably, the polarity of the non-polar solvent according to (iii) is not changed by adding a solvent having an increased polarity relative to the polarity of the non-polar solvent.

[0115] Preferably, (iv) comprises

[0116] (iv.1) feeding the solid mixture containing the precipitated polyolefin P obtained according to (iii), more preferably according to (iii.2), optionally according to (iii.4), and optionally according to (iii.6) P to a pyrolysis reactor R P ;

[0117] (iv.2) introducing into the pyrolysis reactor R PThe precipitated polyolefin is heated at a temperature in the range of 350 °C to 900 °C, more preferably in the range of 400 °C to 550 °C, and at a pressure in the range of 0.5 to 2 bar (absolute), more preferably in the range of 0.9 to 1.5 bar (absolute);

[0118] (iv.3) Remove the gas stream V from the top of R P and subject V to condensation conditions in a gas-liquid separation unit LGU to obtain pyrolysis oil O P .

[0119] Preferably, the precipitated polyolefin obtained according to (iii), preferably according to (iii.2), optionally according to (iii.4), optionally according to (iii.6) is fed via a metering unit, which is more preferably one or more of a screw, an extruder, and a rotary valve.

[0120] It is also conceivable to feed the precipitated polyolefin into the pyrolysis reactor R via a pneumatic conveyor or a liquid injector P .

[0121] Furthermore, (iv.1) may further comprise

[0122] preferably preheating the solid mixture containing the precipitated polyolefin by internal friction or by a heat exchanger in an extruder. Preferably, the heat exchanger uses the electrical energy of the combustion energy from the pyrolysis gas or other heat sources.

[0123] It is conceivable that, prior to the pyrolysis according to (iv), the solid mixture containing the precipitated polyolefin may be subjected to pre-pyrolysis at a temperature in the range of 220 °C to 360 °C. If PVC is present in the solid mixture, this pyrolysis at a low temperature allows the pyrolysis of PVC. However, in the context of the present invention, this step can be avoided in view of the specific method steps (i) to (iii) prior to (iv) of the method according to the present invention.

[0124] Preferably, the pyrolysis reactor R P is selected from the group consisting of: fluidized bed, moving bed, entrained flow, auger, screw reactor, extruder, stirred tank reactor, and rotary kiln, more preferably a fluidized bed. Preferably, the fluidized bed is bubbling, turbulent, fast, or circulating.

[0125] Preferably, the pyrolysis is carried out in the pyrolysis reactor R P in an oxygen-free atmosphere.

[0126] Preferably, the pyrolysis is carried out by thermal cracking (in the absence of a catalyst) or catalytic cracking, more preferably thermal cracking.

[0127] It should be noted that such catalysts are used to influence the properties of the pyrolysis products as known to the skilled person.

[0128] Preferably, the pyrolysis according to (iv) is not a hydrothermal treatment.

[0129] Optionally, according to (iv), the pyrolysis reactor R P Contains trace amounts of water, wherein preferably the trace amounts of water are based on the precipitated polyolefin P P The total weight of the composition is less than 2 wt.% water, more preferably less than 1 wt.% water, and more preferably less than 0.1 wt.% water.

[0130] Preferably, the pyrolysis reactor R P Does not contain water.

[0131] The precipitated polyolefin obtained according to (iii) of the method of the present invention is advantageously pyrolyzed under thermal conditions in the absence of water at a pressure close to atmospheric pressure. The method of the present invention does not require water or a hydrothermal reactor, which greatly reduces equipment cost and complexity, because it is well known that hydrothermal conditions are corrosive. In addition, hydrothermal conditions are not easy to implement under a continuous process, and a continuous process is often necessary on a large scale. Finally, by avoiding hydrothermal treatment as in US2019 / 0322832 A1, no additional water treatment steps and equipment are required to remove pollutants. In addition, the method of the present invention also reduces undesirable byproducts such as coke that accumulate in a hydrothermal reactor.

[0132] Preferably, in the pyrolysis reactor R P In the process, a solid mixture containing the precipitated polyolefin is mixed with CaO, Ca(OH) 2 and CaCO 3 A mixture of one or more of the above.

[0133] Such additives make it possible to react with the HCl formed and thus remove impurities such as chlorine from the PVC.

[0134] Additionally or alternatively, it is conceivable to pass the gas stream V leaving the pyrolysis reactor through a catalyst bed or an adsorption bed in order to reduce the concentration of impurities and atoms other than C and H.

[0135] Preferably, in (iv.3), in R P After removing V from the LGU and before subjecting V to condensation conditions in the LGU, the gas stream V is passed through a filtration unit, more preferably a filter, or a cyclone separator.

[0136] Such a filter unit or cyclone allows to remove dust particles from the gas stream V before condensation. In addition to such dust removal, a catalyst bed or an adsorption bed can be used upstream or downstream thereof to reduce the concentration of impurities and atoms other than C and H.

[0137] Preferably, according to (iv.3), V is subjected to a condensation step in the LGU at a temperature in the range of 0 °C to 80 °C; wherein more preferably, the LGU is a condenser, a scrubber or a quench cooler.

[0138] Preferably, the gas stream V in (iv.3) is subjected to a first condensation step at a temperature in the range of 50 °C to 150 °C and a second condensation step at a temperature in the range of 35 °C to 0 °C to obtain pyrolysis oil O P ; each of the first and second condensation steps is more preferably carried out in a separate condenser or quench cooler. Alternatively, the gas stream V in (iv.3) is preferably subjected to only one condensation step at a temperature in the range of 0 °C to 80 °C.

[0139] The non-condensable "permanent" gas G leaving the LGU can be used to generate process heat / electricity by burning in a gas burner, a gas engine or a combined heat and power plant. The flue gas from such combustion may need to be cleaned according to emission regulations to remove dust, ash and other components.

[0140] The solid residue SR from the pyrolysis can be disposed of or further processed to recover valuable substances such as fibers, metals, carbon black, depending on the specific properties and composition of the solid material M.

[0141] Preferably, the method further comprises

[0142] (v) transferring the pyrolysis oil O obtained according to (iv), more preferably (iv.3) P as a stream S O to a purification unit PU to obtain purified pyrolysis oil O PP .

[0143] Preferably, the purification unit PU comprises one or more of a filter, a centrifuge, a decanter and a decanter centrifuge, more preferably one or more of a filter, a centrifuge and a decanter.

[0144] The pyrolysis oil obtained according to (iv), more preferably (iv.3) can be filtered, including possibly using a filter aid to remove solids. Alternatively, the pyrolysis oil can be centrifuged to remove solids.

[0145] Furthermore, in the purification unit PU, water residues can be removed from the pyrolysis oil by decantation or centrifugation. Furthermore, the pH can be adjusted to a pH value of at most 3, or alternatively, to a pH value of at least 8, preferably at least 9. Preferably, the adjustment is carried out by adding: an acid or a base, such as an alkali metal hydroxide, for example sodium hydroxide (NaOH), potassium hydroxide (KOH), an alkaline earth metal hydroxide, for example calcium hydroxide (Ca(OH)2 ), NH 3 or a mixture thereof, sulfuric acid (H 2 SO 4 ), nitric acid (HNO 3 ), or phosphoric acid (H 3 PO 4 ).

[0146] Preferably, (v) includes

[0147] (v.1) transferring stream S O to a filter to obtain a liquid phase containing filtered pyrolysis oil and further obtaining a solid phase composed of impurities;

[0148] (v.2) introducing the liquid phase containing filtered pyrolysis oil into a settler or centrifuge for water removal to obtain pyrolysis oil having a water content of at most 0.3 wt.-%, more preferably at most 0.1 wt.-%, more preferably at most 0.01 wt.-%, more preferably 0 wt.-% based on the weight of the pyrolysis oil; and further obtaining water;

[0149] (v.3) optionally adjusting the pH of the pyrolysis oil obtained according to (v.2) such that the pH is at most 3 or at least 8;

[0150] (v.4) introducing the pyrolysis oil obtained according to (v.2) or optionally according to (v.3) into a distillation column to obtain purified pyrolysis oil.

[0151] Preferably, (v) further includes

[0152] (v.5) subjecting the purified pyrolysis oil obtained according to (v.4) to hydrotreating conditions in a reactor to obtain purified pyrolysis oil O PP .

[0153] The pyrolysis oil is preferably further processed to remove halogens, for example by hydrotreating. In the context of the present invention and as known in the art, hydrotreating (or hydroprocessing) is a catalytic reduction process for upgrading hydrocarbons. The purpose of hydrotreating is to hydrogenate while removing unwanted heteroatoms present in the pyrolysis oil, such as but not limited to N, P, O, S, Si, F, Cl, Br, I and reducing the amount of double bonds and (if necessary) aromatic compounds. Such treatments are well known in the art and are disclosed in "CHAPTER TWO - Distillate Hydrotreating", Refinery Refining Processes Handbook, 2003, pages 29 - 61. The hydrotreating may be followed by a hydrocracking step. Additionally, it is conceivable that after hydrotreating / hydrocracking, the pyrolysis oil is further distilled to separate the oil into different fractions.

[0154] Preferably, the method is a continuous method or a semi - continuous method, preferably, the method is a continuous method.

[0155] The present invention further relates to a production apparatus for carrying out the method of the present invention, the production apparatus comprising

[0156] - a reactor unit R D ;

[0157] - means for introducing a solid material M containing polyolefins into R D ;

[0158] - means for introducing a liquid stream S containing a non - polar solvent LS into R D where 80 wt% to 100 wt% of S LS consists of a non - polar solvent, and where S LS has a temperature T SLS < T ES and T ES is the boiling temperature of the non - polar solvent;

[0159] - means for removing from R D a liquid stream S containing dissolved polyolefins P ;

[0160] - a solid - liquid separation unit SLU;

[0161] - means for introducing the liquid stream S P into SLU;

[0162] - a pyrolysis reactor R P ;

[0163] - A precipitation device for obtaining a solid mixture containing precipitated polyolefin P P ;

[0164] - A device for introducing a solid mixture containing precipitated polyolefin P P into R P .

[0165] Preferably, the production device of the present invention further includes the aforementioned listed units and elements for carrying out the method according to the present invention. Preferably, the production device further includes one or more of a chopping unit US1, a grinding unit US2, a distillation column D, a gas - liquid separation unit LGU, and a purification unit PU, wherein the units are as defined herein in the context of the method of the present invention.

[0166] The present invention further relates to a pyrolysis oil obtainable or obtained by the method according to the present invention.

[0167] Preferably, based on the weight of the pyrolysis oil, the pyrolysis oil has a C content of at least 80 wt -%, more preferably in the range of 82 wt-% to 87 wt-%, more preferably in the range of 82 wt-% to 86 wt-%, and the C content is determined as described in Analysis 3.

[0168] Preferably, based on the weight of the pyrolysis oil, the pyrolysis oil has an N content of at most 0.5 wt-%, more preferably at most 0.3 wt-%, more preferably at most 0.1 wt-%, and the N content is determined as described in Analysis 3.2. More preferably, the pyrolysis oil has an N content of at most 500 wppm, more preferably at most 100 wppm, and the N content is determined as described in Analysis 3.2.

[0169] Preferably, based on the weight of the pyrolysis oil, the pyrolysis oil has an O content of at most 2 wt-%, more preferably at most 1 wt-%, more preferably at most 0.5 wt-%, more preferably at most 0.3 wt-%, and the O content is determined as described in Analysis 3.2.

[0170] Preferably, based on the weight of the pyrolysis oil, the pyrolysis oil has an S content of at most 50 wppm, more preferably in the range of 0 to 30 wppm, more preferably in the range of 0 to 20 wppm, and the S content is determined as described in Analysis 3.2.

[0171] The present invention further relates to the use of the pyrolysis oil according to the present invention as a naphtha substitute in a steam cracker or in the production of synthesis gas.

[0172] The present invention is further illustrated by the following groups of examples and combinations of examples obtained from the dependencies and cross-references as shown. In particular, it should be noted that in each case where a series of examples is mentioned, for example, in the context of a term such as "a method as described in any one of Examples 1 to 4", each example in this series is intended to be clearly disclosed to a person skilled in the art, that is, the wording of this term should be understood by a person skilled in the art as being synonymous with "a method as described in any one of Examples 1, 2, 3, and 4". In addition, it should be clearly stated that the following groups of examples represent appropriate structural parts of a general description of preferred aspects of the present invention and thus appropriately support but do not represent the claims of the present invention.

[0173] 1. A method for pyrolyzing the polyolefin recovered from a solid material M containing a polyolefin, the method comprising

[0174] (i) providing a liquid stream S containing the polyolefin dissolved in a non-polar solvent P , comprising:

[0175] (i.1) providing the solid material M containing the polyolefin;

[0176] (i.2) providing a liquid stream S comprising a non-polar solvent LS , wherein 80 wt-% to 100 wt-% of S LS consists of the non-polar solvent, and wherein S LS has a temperature T SLS < T ES , T ES being the boiling temperature of the non-polar solvent;

[0177] (i.3) contacting the solid material M provided according to (i.1) with the liquid stream S provided according to (i.2) LS in a reactor unit R D at a temperature T D and a pressure p D , wherein T D < T ES , thereby obtaining a liquid stream S containing the polyolefin dissolved in the non-polar solvent P ;

[0178] (ii) feeding the liquid stream S containing the polyolefin dissolved in the non-polar solvent provided according to (i) P into a solid-liquid separation unit SLU, thereby obtaining a liquid stream S containing the polyolefin dissolved in the non-polar solvent SLU ;

[0179] (iii) subjecting the liquid stream S containing the polyolefin dissolved in the non-polar solvent obtained according to (ii) SLUSubjected to precipitation conditions to obtain a solid mixture containing precipitated polyolefin P P ;

[0180] (iv) Subjecting the solid mixture containing the precipitated polyolefin P obtained according to (iii) P to pyrolysis conditions in a pyrolysis reactor R P to obtain pyrolysis oil O P .

[0181] 2. The method according to Example 1, wherein the polyolefin is selected from the group consisting of: polyethylene (PE), polypropylene (PP), polymethylpentene (PMP), polybutene-1 (PB-1), ethylene-octene copolymer, stereoblock PP, olefin block copolymer, propylene-butane copolymer, polyisobutylene (PIB), ethylene-propylene rubber (EPR), ethylene-propylene-diene monomer rubber (EPDM rubber), and mixtures of two or more thereof, preferably selected from the group consisting of: polyethylene, polypropylene, and mixtures of polyethylene and polypropylene.

[0182] 3. The method according to Example 1 or 2, wherein providing the solid material M containing the polyolefin according to (i.1) includes

[0183] chopping the solid material M containing the polyolefin in a chopping unit US1.

[0184] 4. The method according to any one of Examples 1 to 3, wherein 90 wt% to 100 wt%, preferably 95 wt% to 100 wt%, preferably 99 wt% to 100 wt%, more preferably 99.5 wt% to 100 wt% of S provided in (i.2) LS consists of the non-polar solvent.

[0185] 5. The method according to any one of Examples 1 to 4, wherein the non-polar solvent is selected from the group consisting of: xylene, toluene, n-heptane, amyl acetate, n-amyl acetate, isobutyl acetate, n-propyl propionate, n-butyl propionate, heptan-2-one, methyl-cyclohexane, cyclohexane, and mixtures of two or more thereof, preferably selected from the group consisting of: xylene, toluene, amyl acetate, cyclohexane, and mixtures of two or more thereof, more preferably selected from the group consisting of: xylene, toluene, amyl acetate, and cyclohexane, and more preferably is xylene.

[0186] 6. The method according to any one of Examples 1 to 5, wherein the non-polar solvent has a Hansen solubility parameter δ in the range of 0 to 10 MPa 1 / 2 preferably in the range of 0 to 8 MPa 1 / 2 more preferably in the range of 0 to 7 MPa 1 / 2 ​H 。

[0187] 7. The method according to any one of embodiments 1 to 6, wherein the solid material M provided according to (i.1) contains waste, more preferably consists of waste, and wherein the waste more preferably contains plastic waste.

[0188] 8. The method according to any one of embodiments 1 to 7, wherein the solid material M contains one or more of the following in addition to the polyolefin: polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyurethane (PU), paper, aluminum, and polyamide.

[0189] 9. The method according to any one of embodiments 1 to 8, wherein T SLS is in the range of 55 °C to 150 °C, preferably in the range of 60 °C to 140 °C.

[0190] 10. The method according to any one of embodiments 1 to 9, wherein T D is in the range of 55 °C to 150 °C, preferably in the range of 60 °C to 140 °C.

[0191] 11. The method according to any one of embodiments 1 to 10, wherein p D is in the range of 800 to 200,000 hPa, preferably in the range of 800 to 10,000 hPa.

[0192] 12. The method according to any one of embodiments 1 to 11, wherein before (i.3), the solid material M containing the polyolefin is fed into the reactor unit R D by gravity or pneumatic conveying.

[0193] 13. The method according to any one of embodiments 1 to 12, wherein, in the reactor unit R D the weight ratio of the solid material M to the non-polar solvent is in the range of 1:1 to 1:20, preferably in the range of 1:3 to 1:15, more preferably in the range of 1:4 to 1:12.

[0194] 14. The method according to any one of embodiments 1 to 13, wherein (i.3) comprises

[0195] bringing the solid material M provided according to (i.1) into contact and mixing with the liquid stream S provided according to (i.2) LS in the reactor unit R D at a temperature T D and a pressure p D and preferably stirring, wherein T D <T ES, thereby obtaining a liquid stream S containing the polyolefin dissolved in the non-polar solvent P .

[0196] 15. The method according to any one of embodiments 1 to 14, wherein the reactor unit R D comprises z chemical reactors R Di , i = 1…z, where z is in the range of 1 to 5, preferably in the range of 1 to 3;

[0197] wherein, preferably, when z>1, at least 2 reactors R Di are arranged in parallel, and more preferably z reactors R Di are arranged in parallel.

[0198] 16. The method according to embodiment 15, wherein the temperature T of the z reactors R Di is maintained by heating the contents thereof, preferably by passing a heating medium through the heating jacket of R Di . Di in the z reactors R Di .

[0199] 17. The method according to any one of embodiments 1 to 16, which comprises, before (ii),

[0200] maintaining the temperature T of the liquid stream S containing the polyolefin dissolved in the non-polar solvent obtained according to (i.3) P such that 50 °C < T SP < T SP < T ES .

[0201] 18. The method according to any one of embodiments 1 to 17, wherein the solid-liquid separation unit SLU is a filtration unit F1, preferably a stirred pressure filter, and the filtration unit F1 preferably has a mesh size in the range of 1 to 100 microns, more preferably in the range of 1 to 20 microns.

[0202] 19. The method according to embodiment 18, wherein the filtration unit F1 comprises a filter for blocking solid contaminants and a receiving container for the liquid stream S containing the polyolefin dissolved in the non-polar solvent SLU .

[0203] wherein the solid contaminants are one or more of polymers other than polyolefin, polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyurethane (PU) and polyamide (PA).

[0204] 20. The method according to embodiment 18 or 19, wherein the filtration unit F1 operates at a pressure p F , where p F≥1 bar (absolute), preferably p F in the range from 1 to 30 bar (absolute), more preferably in the range from 1 to 10 bar (absolute), even more preferably in the range from 1 to 6 bar (absolute).

[0205] 21. The method according to any one of embodiments 1 to 20, wherein (iii) comprises

[0206] (iii.1) subjecting the liquid stream S comprising the polyolefin dissolved in the non-polar solvent obtained according to (ii) SLU at a temperature T P and a pressure p P to precipitation, wherein T P < T D and T P < 100 °C, thereby obtaining a solid mixture comprising the precipitated polyolefin P P .

[0207] 22. The method according to embodiment 21, wherein (iii.1) comprises

[0208] cooling the liquid stream S comprising the polyolefin dissolved in the non-polar solvent P at a temperature T P and a pressure p SLU to effect precipitation, wherein T P < T D and T P < 100 °C, thereby obtaining a stream P comprising the polyolefin precipitated in the non-polar solvent.

[0209] 23. The method according to embodiment 21 or 22, wherein T P < T D -5 °C, preferably T P ≤ T D -10 °C, more preferably T P ≤ T D -30 °C, even more preferably T P < T D < -30 °C.

[0210] 24. The method according to embodiment 22 or 23, wherein the cooling according to (iii.1) comprises

[0211] (iii.1.a) transferring a cooling medium to the cooling jacket of the receiving vessel of the filtration unit containing S SLU ; or

[0212] (iii.1.b) allowing the liquid stream S SLU to stand in the receiving vessel of the filtration unit.

[0213] 25. The method according to any one of embodiments 22 to 24, wherein the cooling rate is in the range of 2 to 200 K / h, preferably in the range of 3 to 150 K / h, more preferably 20 to 120 K / h.

[0214] 26. The method according to any one of embodiments 1 to 20, wherein (iii) comprises

[0215] (iii.1’) contacting the SLU with a polar solvent to subject the liquid stream S comprising the polyolefin dissolved in the nonpolar solvent obtained according to (ii) SLU to precipitation, thereby obtaining a stream P comprising the polyolefin precipitated in the polar solvent and the nonpolar solvent.

[0216] 27. The method according to any one of embodiments 1 to 26, wherein (iii) comprises

[0217] (iii.1) subjecting the liquid stream S comprising the polyolefin dissolved in the nonpolar solvent obtained according to (ii) SLU at a temperature T P and a pressure p P to precipitation, where T P <T D and T P <100 °C, thereby obtaining a solid mixture comprising the precipitated polyolefin P P , preferably cooling the liquid stream S comprising the polyolefin dissolved in the nonpolar solvent P at a temperature T P and a pressure p SLU for precipitation, where T P <T D and T P <100 °C, thereby obtaining a stream P comprising the polyolefin precipitated in the nonpolar solvent; or

[0218] (iii.1') contacting the SLU with a polar solvent to subject the liquid stream S comprising the polyolefin dissolved in the nonpolar solvent obtained according to (ii) SLU to precipitation, thereby obtaining a stream P comprising the polyolefin precipitated in the polar solvent and the nonpolar solvent;

[0219] (iii.2) transferring the stream P obtained according to (iii.1) or (iii.1'), preferably (iii.1), to a filtration unit F2, thereby obtaining a solid mixture comprising the precipitated polyolefin P P separated from the nonpolar solvent and the polar solvent (when applicable);

[0220] (iii.3) Optionally, wash the solid mixture containing the precipitated polyolefin obtained according to (iii.2), preferably wash the solid mixture with one or more of methanol, ethanol, propanol, isopropanol, acetonitrile, ethyl acetate, acetone, and water;

[0221] (iii.4) Optionally, dry the solid mixture containing the washed precipitated polyolefin obtained according to (iii.3).

[0222] 28. The method according to Example 27, wherein (iii) further comprises

[0223] (iii.5) Recycle at least a portion of the nonpolar solvent obtained according to (iii.2) as a component of the liquid stream S in (i.2); LS of.

[0224] wherein preferably (iii.5) comprises

[0225] (iii.5.1) Transfer at least a portion of the nonpolar solvent obtained according to (iii.2) to a distillation unit D to obtain a purified nonpolar solvent;

[0226] (iii.5.1) Add the purified nonpolar solvent obtained according to (iii.5.1) to the liquid stream S in (i.2) LS in.

[0227] 29. The method according to any one of Examples 1 to 28, wherein (iii) further comprises

[0228] (iii.6) In a comminution unit US2, comminute the dry solid mixture containing the precipitated polyolefin obtained according to (iii.4) into flakes having an average size in the range of 0.05 to 10 cm, preferably in the range of 0.1 to 5 cm, more preferably in the range of 0.1 to 1 cm, and the average size of the flakes is measured as defined in Reference Example 1.

[0229] 30. The method according to any one of Examples 1 to 29, wherein the solid mixture obtained according to (iii) contains an amount of the precipitated olefin in the range of 90 wt%-100 wt%, preferably in the range of 95 wt%-100 wt%, based on the weight of the solid mixture.

[0230] 31. The method according to any one of Examples 1 to 30, wherein (iv) comprises

[0231] (iv.1) The polyolefin P containing the precipitate obtained according to (iii), preferably according to (iii.2), optionally according to (iii.4) PThis solid mixture is fed into the pyrolysis reactor R P ;

[0232] (iv.2) The precipitated polyolefin entering the pyrolysis reactor R P is heated at a temperature in the range of 350 °C to 900 °C, preferably in the range of 400 °C to 550 °C, and at a pressure in the range of 0.5 to 2 bar (absolute), preferably in the range of 0.9 to 1.5 bar (absolute).

[0233] (iv.3) A gas stream V is removed from the top of R P and V is subjected to condensation conditions in the gas-liquid separation unit LGU to obtain pyrolysis oil O P .

[0234] 32. The method according to embodiment 31, wherein the feeding of the precipitated polyolefin obtained according to (iii), preferably according to (iii.2), optionally according to (iii.4) is carried out via a metering unit, which is preferably one or more of a screw, an extruder and a rotary valve.

[0235] 33. The method according to embodiment 31 or 32, wherein (iv.1) further comprises

[0236] preferably preheating the solid mixture containing the precipitated polyolefin by internal friction or by a heat exchanger in an extruder.

[0237] 34. The method according to any one of embodiments 29 to 32, wherein the pyrolysis reactor R P is selected from the group consisting of: fluidized bed, moving bed, entrained flow, auger, screw reactor, extruder, stirred tank reactor and rotary kiln, more preferably a fluidized bed.

[0238] 35. The method according to any one of embodiments 1 to 33, wherein the pyrolysis is carried out in the pyrolysis reactor R P in an oxygen-free atmosphere.

[0239] 36. The method according to any one of embodiments 1 to 34, wherein the pyrolysis is carried out by thermal cracking or catalytic cracking, preferably thermal cracking.

[0240] 37. The method according to any one of embodiments 30 to 36, if subordinate to embodiment 35 or 36, then the said embodiment is independent of embodiment 30, wherein in (iv.3), after removing V from R P and before subjecting V to condensation conditions in LGU, V is passed through a filtration unit, preferably a filter, or a cyclone separator.

[0241] 38. The method according to any one of embodiments 30 to 37, if it is subordinate to embodiment 35 or 36, then the said embodiment is independent of embodiment 30, wherein according to (iv.3), V is subjected to a condensation step in the LGU at a temperature in the range of 0 °C to 80 °C; wherein preferably, the LGU is a condenser, a scrubber or a quench cooler.

[0242] 39. The method according to any one of embodiments 1 to 38, which further comprises

[0243] (v) transferring the pyrolysis oil O obtained according to (iv), preferably (iv.3) P as a stream S O to a purification unit PU, thereby obtaining a purified pyrolysis oil O PP .

[0244] 40. The method according to embodiment 39, wherein the purification unit PU comprises one or more of a filter, a centrifuge, a decanter and a decanter centrifuge, preferably one or more of a filter, a centrifuge and a decanter.

[0245] 41. The method according to embodiment 39 or 40, wherein (v) comprises

[0246] (v.1) transferring the stream S O to a filter, thereby obtaining a liquid phase containing the filtered pyrolysis oil and further obtaining a solid phase composed of impurities;

[0247] (v.2) introducing the liquid phase containing the filtered pyrolysis oil into a settler or a centrifuge for water removal, thereby obtaining a pyrolysis oil having a water content of at most 3000 wppm, preferably at most 1000 ppm, more preferably at most 100 wppm, and even more preferably 0 wppm, and further obtaining water;

[0248] (v.3) optionally adjusting the pH of the pyrolysis oil obtained according to (v.2) such that the pH is at most 3 or at least 8;

[0249] (v.4) introducing the pyrolysis oil obtained according to (v.2) or optionally according to (v.3) into a distillation column, thereby obtaining a purified pyrolysis oil.

[0250] 42. The method according to embodiment 41, wherein (v) further comprises

[0251] (v.5) subjecting the purified pyrolysis oil obtained according to (v.4) to hydrotreating conditions in a reactor, thereby obtaining a purified pyrolysis oil O PP .

[0252] 43. The method according to any one of embodiments 1 to 42, wherein the method is a continuous method or a semi - continuous method, preferably the method is a continuous method.

[0253] 44. The method according to any one of embodiments 1 to 43, wherein according to (iii), no other solvent other than the non - polar solvent is involved in these precipitation conditions.

[0254] 45. The method according to any one of embodiments 1 to 44, wherein according to (iii), the polarity of the non - polar solvent does not change due to the addition of a solvent having an increased polarity relative to the polarity of the non - polar solvent.

[0255] 46. The method according to any one of embodiments 1 to 45, wherein according to (iv), these pyrolysis conditions do not include hydrothermal treatment.

[0256] 47. A pyrolysis oil obtainable or obtained by the method according to any one of embodiments 1 to 46.

[0257] 48. The pyrolysis oil according to embodiment 47, based on the weight of the pyrolysis oil, the pyrolysis oil has a C content of at least 80 wt -%, preferably in the range of 82 wt -% to 87 wt -%, more preferably in the range of 82 wt -% to 86 wt -%, and the C content is determined as described in analysis 3.2.

[0258] 49. The pyrolysis oil according to embodiment 47 or 48, based on the weight of the pyrolysis oil, the pyrolysis oil has an N content of at most 0.5 wt -%, more preferably at most 0.3 wt -%, even more preferably at most 0.1 wt -%, and the N content is determined as described in analysis 3.2;

[0259] wherein more preferably, the pyrolysis oil has an N content of at most 500 wppm, more preferably at most 100 wppm, and the N content is determined as described in analysis 3.2.

[0260] 50. The pyrolysis oil according to any one of embodiments 47 to 49, based on the weight of the pyrolysis oil, the pyrolysis oil has an O content of at most 2 wt -%, preferably at most 1 wt -%, more preferably at most 0.5 wt -%, even more preferably at most 0.3 wt -%, and the O content is determined as described in analysis 3.2.

[0261] 51. The pyrolysis oil according to any one of embodiments 47 to 50, based on the weight of the pyrolysis oil, the pyrolysis oil has an S content of at most 50 wppm, preferably in the range of 0 to 30 wppm, more preferably in the range of 0 to 20 wppm, and the S content is determined as described in analysis 3.2.

[0262] Use of the pyrolysis oil as described in any one of Examples 47 to 51 as a naphtha substitute in a steam cracker or in the production of synthesis gas.

[0263] As used in the context of the present invention, the term "bar" refers to "bar (absolute)".

[0264] In the context of the present invention, the term "X is one or more of A, B, and C", where X is a given feature and each of A, B, and C represents a specific implementation of said feature, should be understood to disclose that X is A, or B, or C, or A and B, or A and C, or B and C, or A and B and C. In this regard, it should be noted that a person skilled in the art can translate the above abstract terms into specific examples. For example, where X is a chemical element and A, B, and C are specific elements such as Li, Na, and K, or X is a temperature and A, B, and C are specific temperatures such as 10 °C, 20 °C, and 30 °C. In this regard, it should further be noted that a person skilled in the art can extend the above terms to less specific implementations of said feature, such as "X is one or more of A and B", which discloses that X is A, or B, or A and B, or to more specific implementations of said feature, such as "X is one or more of A, B, C, and D", which discloses that X is A, or B, or C, or D, or A and B, or A and C, or A and D, or B and C, or B and D, or C and D, or A and B and C, or A and B and D, or B and C and D, or A and B and C and D.

[0265] The term "non-polar solvent" used in the present invention refers to a solvent that dissolves non-polar compounds, has a low dielectric constant, and has non-polar bonds. For example, these non-polar solvents can be as described above.

[0266] In the context of the present invention, it should be noted that the terms "gas stream" and "gaseous stream" can be used interchangeably, and both terms mean that the stream is in the gas phase.

[0267] The present invention is further illustrated by the following examples.

[0268] Examples

[0269] Analysis

[0270] Determination of the particle size distribution of the flakes

[0271] The particle size distribution of the polyolefin flakes after solvolysis was determined via from Figure 2Obtained by static image analysis (optical granulometry). Thus, the particles have been dispersed as much as possible and a background with a large contrast to the individual particles has been used. The projected area of the individual particles has been measured with an automatic image analysis tool (imageJ). From the projected area of the individual particles, the diameter of a sphere with the same surface area as the individual particle has been calculated:

[0272]

[0273] where

[0274] D: diameter of the representative sphere

[0275] A: projected surface area of the particle

[0276] From the obtained particle sizes, the number-based and volume-based distributions have been calculated.

[0277] Average particle size (volume-based: exponent 3) Has been calculated by the following:

[0278]

[0279] where

[0280] is the arithmetic mean particle size in the discrete particle size interval x i and x i+1 in the arithmetic mean particle size

[0281] ΔQ 3,i is the amount of particles in the discrete particle size interval (from the cumulative particle size distribution).

[0282] 2NMR

[0283] The content of polyolefin in the sample was determined by quantitative 1H-NMR spectroscopy. All NMR spectra were recorded at T = 298.2 K on a Bruker Avance III 400 spectrometer operating at 400.33 MHz for 1H. The spectrometer was equipped with a 5 mm z-gradient broadband observation smart probe. The chemical shift was referenced to tetramethylsilane (TMS, δ(TMS) = 0 ppm). The 1H 1D spectra were recorded under quantitative conditions using the zg30 pulse program with 128k data points sampled, and the 5 relaxation delay D1 was selected as 40 s for the solvent chloroform-d1 (CDCl3) or 120 s for the solvent sulfuric acid-d2 (D2SO4). Each spectrum totaled 8 transients. For processing in Bruker TopSpin 4.0.9 software, 64k data points were used, and an exponential window function with a line broadening of 0.3 Hz was applied. Automatic baseline correction with a polynomial of 5 was performed, and phase correction and integration were performed manually by the user.

[0284] 3 Elemental analysis

[0285] 3.1 Analysis of mixed municipal solid plastic waste (MMSPW)

[0286]

[0287] 3.2 Elemental analysis of oil samples / polyolefin samples

[0288] C, H, N (combustion) analysis:

[0289] The sample (1 - 10 mg) is combusted in a helium / oxygen atmosphere and the NOx formed is subsequently reduced to N 2 . After separating the combustion gases, nitrogen is determined as N 2 , carbon is determined as CO 2 , and hydrogen is determined as H 2 2O. Detection and quantification are carried out via thermal conductivity. Analyzer: Elementar, model Vario EL Cube

[0290] N (chemiluminescence) analysis: (typically for concentrations below 0.5 g / 100 g)

[0291] The sample (1 - 10 mg or 10 - 30 μl) is combusted in oxygen using argon as the carrier gas at about 1000 °C. Dilution of the sample can be used to extend the linear dynamic range of the method. The combustion gas (NO) reacts with ozone to form the leaving species. The light emitted during relaxation is detected. Analyzer: TE Instruments, e.g., model TN / TS

[0292] O analysis:

[0293] The sample (1 - 10 mg) is pyrolyzed / reduced in a forming gas atmosphere in contact with soot, thereby converting oxygen to carbon monoxide (CO). Carbon monoxide is detected and quantified via IR spectroscopy. Analyzer: Elementar, model rapid OXY cube

[0294] S analysis:

[0295] The sample (1 - 10 mg) is weighed into a tin capsule and placed in the analyzer. The sample is catalytically combusted in an argon / oxygen atmosphere and thereby sulfur is converted to a mixture of SO 2 2 and SO 3 3. Subsequently, the SO 3 2 formed is reduced to SO 2 2. After drying and separating the combustion gases, sulfur is detected via IR spectroscopy and quantified as SO 2 2. Analyzer: Elementar, Unicube

[0296] S(COUS) analysis: (typically for concentrations below 0.05 g / 100 g)

[0297] The sample (1 - 10 mg) is combusted in oxygen using argon as the carrier gas at approximately 1000 °C. The combustion gas (SO 2 ) is transferred to a coulometric cell for detection. (Alternatively, UV fluorescence can be used for post-combustion detection.)

[0298] Analyzer: TE instrument, e.g., model TX / TS (coulometry) (or TN / TS (UV-fluorescence))

[0299] Cl (Rohr and COCL) analysis:

[0300] Chlorine calculated from the sum of chlorine - bromine - iodine (coulometry) (typically for concentrations below 0.5 g / 100 g)

[0301] The sample (1 - 10 mg) is combusted in oxygen using nitrogen as the carrier gas at approximately 1000 °C. The resulting hydrochloric acid in gaseous form is cleaned of combustion by-products (such as water) in concentrated sulfuric acid and then transferred to a coulometric cell for detection. This method does not distinguish between halogens, and thus, the result is presented as a sum parameter (chlorine, bromine, iodine) calculated using the molar mass of chlorine. Analyzer: TE instrument, model TX / TS

[0302] Si analysis:

[0303] An aliquot of 0.3 - 0.4 g of the sample is weighed into a Pt crucible and calcined in a muffle furnace at 600 °C. Then, 0.4 g of K 2 CO 3 -Na 2 CO 3 and 0.1 g of Na 2 B 4 O 7 The mixture is added to the crucible, which is then loaded into an automated digestion system: the crucible is heated by induction to approximately 930 °C while rotating to facilitate dissolution of the sample in the flux mixture. After melting, the digested contents of the crucible are dissolved in dilute HCl, the volume is adjusted to 50 mL, and the Si in the solution is analyzed via ICP - OES. The spectrometer is calibrated with matrix-matched standards. Two aliquots are prepared in parallel, and the average is taken for the final result. Blank subtraction is performed, where blank samples are prepared in a similar manner.

[0304] Example 1 Laboratory-scale experiment

[0305] 60 g of mixed municipal solid plastic waste (the composition of the plastic waste is listed in Table 1 below) was mixed with 300 g of xylene, and the weight ratio of the plastic waste to xylene was thus 1:5. The obtained mixture was stirred in a glass container with a nitrogen blanket at 60 UPM and further heated to 100 °C. Stirring continued for one hour. Then, under a nitrogen pressure of 3 bar (absolute), the mixture was hot-filtered at 100 °C. On the filter, other polymers and contaminants were separated from the mixture. When the xylene in the container below the filter was cooled, the polyolefins began to precipitate at 70 °C. Then they were filtered and dried. 22 g of polyolefins, a mixture of polyethylene (PE) (86% by weight) and polypropylene (PP) (16% by weight), were obtained. The ratio of PE and PP before drying was determined by NMR analysis as defined under Analysis 2 above (NMR: 82% PE, 13% PP, 5% xylene)

[0306] Table 1A Mixed Municipal Solid Plastic Waste (MMSPW)

[0307] Calculated composition kg Weight.-% PE film 159.85 37 PE rigid material 13.91 3.2 PP film 61.41 14.2 PP rigid material 37.39 8.7 PE-PP film 6.69 1.5 PE-PET film 1.77 0.4 Other multilayer films 14.91 3.5 PE-PA film 2.95 0.77 Tetra 1.24 0.3 PU foam 0.76 0.2 Paper and cardboard 1.35 0.3 PVC 9.19 2.1 Black part (unselected plastics) 44.01 10.2 The rest 76.56 17.7 Total 432 100

[0308] Table 1B Elemental analysis of MMSPW and the obtained polyolefins (PO), dry basis

[0309]

[0310] The feedstock composition for the pyrolysis reactor has shown a significant reduction in Cl, O, Si, and ash (as indicated by Si). The reduction factor for Cl was 7.7; for O, the reduction factor > 24 and for Si, the reduction factor was 180. Thus, there was a significant reduction in heteroatom-containing plastics (such as PET, PA, etc.) in the obtained precipitated polyolefins.

[0311] The obtained polyolefin flakes were fed into the pyrolysis autoclave reactor R P (1). The average particle size of the flakes was 15.9 mm. Some flakes had to be cut in order to be fed into the reactor. For the pyrolysis experiment, a laboratory-scale pyrolysis system was used. The flow diagram of the system is shown in Figure 5In the pyrolysis system, a batch reactor (1) with a volume of about 0.14 L, an electric heating oven (5), two condensers (7) and (8), and two washing bottles (10) and (11) are included. As the first step, the reactor (1) is filled with the obtained precipitated polyolefin by weighing. Then a pressure test is carried out to ensure the system is airtight. In addition, the equipment volume is flushed with nitrogen (3) before and during the experiment to ensure an oxygen-free atmosphere in the device. The oven (5) is preheated to 570 °C. After the pressure test and inerting, the oven (5) is raised to enclose the reactor (1). Subsequently, the reactor (1) is heated to a reaction temperature of 550 °C (1.1 bar (absolute)). The reaction temperature is measured via a NiCrNi-thermocouple (4). The reaction temperature is reached after about 15 min, which corresponds to an average heating rate of about 35 K / min. The discharged pyrolysis vapors and gases from the reactor (1) flow through the heated pipe (6) to prevent condensation before the cold traps (7) and (8). The pyrolysis gas stream V condenses in the two cold traps (7) and (8) to obtain the pyrolysis product oil O P . The temperature of the first cold trap (7) is adjusted to 45 °C via a heating plate (9), while the temperature of the second cold trap (8) is adjusted to about 0 °C via a cooling bath (10) with ice water. The non-condensable gases are cleaned with NaOH in the washing bottle (11) and with distilled water in the washing bottle (12). The exhaust gas (13) is led to the exhaust port of the steamer. 30 min after reaching the reaction temperature of 550 °C, the pyrolysis is completed and the oven heating (5) is turned off.

[0312] The obtained pyrolysis oil is analyzed, and the results are shown in Tables 2 and 3.

[0313] Comparative Example 1

[0314] The mixed municipal solid plastic waste with the composition listed in Table 1 is fed into the pyrolysis batch reactor (1), however, the dissolution / precipitation according to the present invention is not carried out before pyrolysis. Additionally, the pyrolysis experiments and conditions are the same for both Example 1 and this Comparative Example 1.

[0315] The obtained pyrolysis oil is analyzed, and the results are shown in Tables 2 and 3.

[0316] Reference Example 1

[0317] LDPE (low-density polyethylene) is fed into the pyrolysis batch reactor (1), however, the dissolution / precipitation according to the present invention is not carried out before pyrolysis. Additionally, the pyrolysis experiments and conditions are the same for all of Example 1, Comparative Example 1, and Reference Example 1.

[0318] The obtained pyrolysis oil is analyzed, and the results are shown in Table 2.

[0319] Table 2 Pyrolysis Yield

[0320]

[0321] As shown in Table 2, the pyrolysis yields obtained by the method according to the invention are very similar to those obtained after pyrolyzing LDPE (raw plastic), which indicates that the method according to the invention allows obtaining yields as high as those obtained for raw polyolefin plastics from mixed municipal plastic waste. In addition, the comparison between Example 1 and Comparative Example 1 shows that the specific pretreatment disclosed in the present invention allows a significant improvement in the oil yield, i.e., from 66.6 wt.-% to 82.4 wt.-%, and a significant reduction in impurities, with the coke being reduced from 14.7 wt.-% to only 0.7 wt.-%.

[0322] Elemental analysis of the pyrolysis oil obtained in Table 3

[0323]

[0324] a Chemiluminescence method; b Combustion method

[0325] As shown in Table 3, the pyrolysis oil obtained by the method according to the invention has a lower Cl content, i.e., about 39.6 times lower than that of Comparative Example 1, and lower N, O, and S contents, for example, the N content and S content are reduced by 66 times and 8 times, respectively.

[0326] Therefore, it has been clearly demonstrated that the method according to the invention exhibits a better pyrolysis oil yield and is more cost-effective, since the further treatment of the oil can be significantly reduced. Compared with the prior art, the improved coke reduction is very important in terms of the CO 2 footprint (reducing the need for landfills / incinerators). Therefore, the method according to the invention allows simplifying the entire polyolefin recycling process, which also allows cost reduction. Thus, the method for recycling polyolefins from solid materials containing polyolefins using pyrolysis according to the invention allows reducing the CO 2 footprint. Description of the drawings

[0327] Figure 1 is a schematic diagram of a production apparatus for the method according to a preferred embodiment of the invention.

[0328] The production apparatus includes a reactor unit R D , a shredding unit US1, a solid-liquid separation unit SLU including a filter F1, a pyrolysis reactor RP, a filter F2, a liquid-gas separation unit LGU, and optionally a distillation unit D, a washing and drying unit W / D, and a purification unit U. A solid material M (e.g., plastic waste) containing polyolefins (preferably PP and PE) is fed into the shredding unit US1. The flakes / fragments of M obtained from US are fed into the reactor unit RD Also, a liquid stream S containing a non-polar solvent is LS fed to a reactor unit R D for dissolving a solid material M at a temperature T D and a pressure p, where T D <T D and T ES is the boiling temperature of the non-polar solvent of S, as ES previously detailed. The liquid stream S is removed from the LS bottom of R, and S contains polyolefin dissolved in the P non-polar solvent. The liquid stream S is fed to a solid-liquid D separation unit SLU to obtain a liquid stream S containing P polyolefin dissolved in the non-polar solvent. The liquid P stream S is preferably subjected to precipitation by SLU cooling the temperature of the solvent in SLU, as SLU previously detailed. The liquid stream P leaving SLU and P containing precipitated polyolefin P and non-polar solvent P is fed to a filter F2, where P is blocked on F2 and the NP non-polar solvent S passes through. The solid waste w1 is P removed from F1, and w1 especially contains other P undissolved polyolefins and contaminants such as those P listed previously. Then the precipitated polyolefin P is Figure 1 not shown in P (flakes) subjected to pyrolysis as previously detailed, P obtaining a gas stream V containing hydrocarbons at the P top of the reactor and a solid residue SR at the bottom of PP the reactor. The stream V is fed to a liquid-gas separation

[0329] Figure 2 unit LGU to obtain a liquid stream of pyrolysis oil O

[0330] Figure 3 and a gas stream G of non-condensable pyrolysis gas. The

[0331] Figure 4 Shows the particle size distribution of the precipitated polyolefin flakes obtained according to (iii) to be pyrolyzed according to (iv). The average particle size of the flakes is 15.9 mm.

[0332] Figure 5 Is a schematic diagram of the pyrolysis device for Example 1, Comparative Example 1 and Reference Example 1 - 1. Reactor; 2. Plastic raw material; 3. Nitrogen (inerting and flushing of the reactor); 4. Thermocouple; 5. Electric heating oven; 6. Heated pipe; 7. First cold trap; 8. Second cold trap; 9. Heating plate; 10. Cooling bath; 11. Washing bottle (NaOH); 12. Washing bottle (distilled water); 13. Exhaust gas.

[0333] Cited literature

[0334] - Hansen, C.M., Hansen Solubility Parameters - A user’s handbook, 2.Edition, CRC Press, Boca Raton, USA, 2007

[0335] - CHAPTER TWO - Distillate Hydrotreating, Refinery Refining Processes Handbook, 2003, Pages 29 - 61

[0336] - US 2019 / 0322832 A1

Claims

1. A method for pyrolyzing the polyolefin recovered from the solid material M containing polyolefin, the method comprising (i) Provide a liquid stream S containing a polyolefin dissolved in a non-polar solvent P , comprising: (i.1) providing the solid material M containing the polyolefin; (i.2) Provide a liquid stream S containing a non-polar solvent LS , where 80 wt-% to 100 wt-% of S LS consists of this non-polar solvent, and where S LS has a temperature T SLS < T ES , T ES is the boiling temperature of this non-polar solvent; (i.3) Bring the solid material M provided according to (i.1) into contact with the liquid stream S provided according to (i.2) LS in the reactor unit R D at a temperature T D and a pressure p D such that T D < T ES to obtain a liquid stream S containing the polyolefin dissolved in the nonpolar solvent P ; (ii) Feed the liquid stream S containing the polyolefin dissolved in the non-polar solvent provided in (i) P into the solid-liquid separation unit SLU to obtain a liquid stream S containing the polyolefin dissolved in the non-polar solvent SLU ; (iii) subjecting the liquid stream S containing the polyolefin dissolved in the non-polar solvent obtained in (ii) SLU to precipitation conditions to obtain a solid mixture containing precipitated polyolefin P P ; (iv) subject the solid mixture containing the precipitate of polyolefin P obtained in (iii) P to pyrolysis conditions in a pyrolysis reactor R P to obtain pyrolysis oil O P .

2. The method according to claim 1, wherein, the polyolefin is selected from the group consisting of: polyethylene (PE), polypropylene (PP), polymethylpentene (PMP), polybutene-1 (PB-1), ethylene-octene copolymer, stereoblock PP, olefin block copolymer, propylene-butane copolymer, polyisobutene (PIB), ethylene-propylene rubber (EPR), ethylene-propylene-diene monomer rubber (M-class rubber) (EPDM rubber), and mixtures of two or more thereof, preferably selected from the group consisting of: polyethylene, polypropylene, and mixtures of polyethylene and polypropylene.

3. The method according to claim 1 or 2, wherein, the non-polar solvent is selected from the group consisting of: xylene, toluene, n-heptane, amyl acetate, n-amyl acetate, isobutyl acetate, n-propyl propionate, n-butyl propionate, heptan-2-one, methyl-cyclohexane, cyclohexane, and mixtures of two or more thereof, preferably selected from the group consisting of: xylene, toluene, amyl acetate, cyclohexane, and mixtures of two or more thereof, more preferably selected from the group consisting of: xylene, toluene, amyl acetate and cyclohexane, and more preferably is xylene.

4. The method according to any one of claims 1 to 3, wherein, 5 wt%-99 wt%, preferably 20 wt%-98.5 wt%, more preferably 30 wt%-98 wt%, more preferably 40 wt%-98 wt% of M consists of the polyolefin.

5. The method according to any one of claims 1 to 4, wherein, T D in the range of 55 °C to 150 °C, preferably in the range of 60 °C to 140 °C; wherein p D preferably in the range of 800 to 200,000 hPa.

6. The method according to any one of claims 1 to 5, wherein, In the reactor unit R D the weight ratio of the solid material M to the nonpolar solvent ranges from 1:1 to 1:20, preferably from 1:3 to 1:15, more preferably from 1:4 to 1:

12.

7. The method according to any one of claims 1 to 6, wherein, (i.3) includes Bring the solid material M provided according to (i.1) into contact and mix it with the liquid stream S provided according to (i.2) LS in a reactor unit R D at a temperature T D and a pressure p D while preferably stirring, where T D < T ES to obtain a liquid stream S containing the polyolefin dissolved in the non-polar solvent P .

8. The method according to any one of claims 1 to 7, which includes before (ii), Maintain the temperature T of the liquid stream S containing the polyolefin dissolved in the non-polar solvent obtained according to (i.3) P such that 50 °C < T SP < T SP < ES .

9. The method according to any one of claims 1 to 8, wherein, The solid-liquid separation unit SLU is the filtration unit F1, which operates at a pressure p F where p F ≥ 1 bar (absolute), preferably p F is in the range from 1 to 30 bar (absolute), more preferably in the range from 1 to 10 bar (absolute), even more preferably in the range from 1 to 6 bar (absolute).

10. The method according to any one of claims 1 to 9, wherein, (iii) includes (iii.1) subject the liquid stream S containing the polyolefin dissolved in the non-polar solvent obtained in (ii) SLU to precipitation at a temperature T P and a pressure p P wherein T P < T D and T P < 100 °C, thereby obtaining a solid mixture containing the precipitated polyolefin P P ​ Preferably at a temperature T P and a pressure p P the liquid stream S containing the polyolefin dissolved in the nonpolar solvent is cooled SLU to effect precipitation, where T P < T D and T P < 100 °C, more preferably T P ≤ T D - 10 °C, more preferably T P ≤ T D - 30 °C, more preferably T P < T D < - 30 °C, thereby obtaining a stream P containing the polyolefin precipitated in the nonpolar solvent; or (iii.1') By bringing the SLU into contact with a polar solvent, the liquid stream S containing the polyolefin dissolved in the non-polar solvent obtained according to (ii) SLU is subjected to precipitation, thereby obtaining a stream P containing the polyolefin precipitated in the polar solvent and the non-polar solvent; (iii.2) The stream P obtained according to (iii.1) or (iii.1'), preferably (iii.1), is fed into the filtration unit F2 so as to obtain a solid mixture containing the precipitate of polyolefin P separated from the non-polar solvent and the polar solvent - when applicable - P thereof; (iii.3) optionally washing the solid mixture containing the precipitated polyolefin obtained according to (iii.2), preferably washing the solid mixture with one or more of methanol, ethanol, propanol, isopropanol, acetonitrile, ethyl acetate, acetone and water; (iii.4) optionally drying the solid mixture containing the washed precipitated polyolefin obtained according to (iii.3).

11. The method according to claim 10, wherein, (iii) further includes (iii.5) Recycle at least a portion of the nonpolar solvent obtained in (iii.2) as a component of the liquid stream S in (i.2). LS ​ 12. The method according to any one of claims 1 to 11, wherein, according to (iii), no solvent other than the non-polar solvent is involved in these precipitation conditions, and preferably the solvent polarity according to (iii) is not changed by adding a solvent having an increased polarity relative to the non-polar solvent.

13. The method according to any one of claims 1 to 12, wherein, (iv) includes (iv.1) The polyolefin P containing the precipitate obtained according to (iii), preferably according to (iii.2), and optionally according to (iii.4) P is fed into the pyrolysis reactor R P therein; (iv.2) The precipitated polyolefin entering the pyrolysis reactor R P is heated at a temperature in the range of 350 °C to 900 °C, preferably in the range of 400 °C to 550 °C, and at a pressure in the range of 0.5 to 2 bar (absolute), preferably in the range of 0.9 to 1.5 bar (absolute); (iv.3) Remove the gas stream V from the top of R P and subject V to condensation conditions in the gas-liquid separation unit LGU to obtain pyrolysis oil O P .

14. The method according to claim 13, wherein, According to (iv.3), subject the gas stream V to a condensation step in the LGU at a temperature in the range from 0 °C to 80 °C; preferably, the GLU is a condenser or a quencher, thereby obtaining the pyrolysis oil O P .

15. The method according to any one of claims 1 to 14, further comprising (v) The pyrolysis oil O obtained according to (iv), preferably (iv.3) P is conveyed as stream S O to a purification unit PU, thereby obtaining purified pyrolysis oil O PP .

16. A pyrolysis oil obtainable or obtained by a method according to any one of claims 1 to 15, the pyrolysis oil preferably having an S content of at most 50 wppm based on the weight of the pyrolysis oil, wherein more preferably, the pyrolysis oil has one or more of the following: a C content of at least 80 weight-% based on the weight of the pyrolysis oil, more preferably in the range of 82 weight-% to 87 weight-%, more preferably in the range of 82 weight-% to 86 weight-%, an N content of at most 0.5 weight-% based on the weight of the pyrolysis oil, more preferably at most 500 wppm, more preferably at most 100 wppm, and an O content of at most 2 weight-% based on the weight of the pyrolysis oil, more preferably at most 1 weight-%, more preferably at most 0.5 weight-%, more preferably at most 0.3 weight-%.

17. Use of the pyrolysis oil according to claim 16 as a naphtha substitute in a steam cracker or in the production of synthesis gas.

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