Method of manufacture

Abstract

Present invention concerns stepwise processing of post-consumer waste (for instance collected from recycling), consisting of a polyolefin polymer fraction, contaminated with a non-polyolefin polymer fraction and (non-)polymer contaminants, where the polyolefin fraction is converted into hydrocarbon products (alkanes, alkenes, naphthenes, aromatics). The first step comprises contacting the contaminated polyolefin fraction in a liquid medium at elevated temperature to access the non-polyolefin fraction and non-polymer fraction from the melt. The second step comprises the separation of the cleaner polyolefin melt from the non-polyolefin fraction and non-polymer fraction that is dispersed in the liquid medium. The final step comprises the conversion of the cleaner polyolefin fraction to a hydrocarbon stream composed of a mixture of alkanes, alkenes, naphthenes, and / or aromatics, using a catalytic process. Present invention describes a consecutive approach as a solution for the problem where catalytic conversion of post-consumer plastic waste is deactivated as a result of the direct contact between contaminants in the feedstock and the active sites of the catalyst.

Description

[0001] METHOD OF MANUFACTURE

[0002] FIELD OF THE INVENTION

[0003] In general, the present disclosure relates to a method for mixed recycling plastic products or mixed plastic article, such as waste plastics. More particularly, the present invention relates to a method of recycling of mixtures of different plastic products (for instance plastic waste) and transforming at least one polymer fraction, the polyolefin fraction, into hydrocarbon products (alkanes, alkenes, naphthenes, aromatics) to be further reprocessed, for instanced by chemical industry.

[0004] For instance, a plastic waste feedstock comprises a polyolefin fraction and non-polyolefin constituents. The polyolefin fraction could be targeted for depolymerization via a catalytic process, where the catalyst acts in direct contact with the plastic feedstock. Unfortunately, the presence of the non- polyolefin constituents in the feedstock leads to catalyst deactivation and should be mitigated.

[0005] Thus, there exists a need for an upgrading process for recycling plastic products that does not require extensive preliminary sorting and expensive pretreatments and that may be used for recycling mixtures different plastic materials that comprise polyolefins.

[0006] Current invention thus provides a solution to overcome catalyst deactivation in chemical recycling of plastic waste, supporting the valorisation of plasticbased carbon into secondary high-value products.

[0007] BACKGROUND OF THE INVENTION

[0008] The plastic waste feedstock can for example be a mixture of a reclaimed plastic waste or a post-consumer plastic waste (PCW), composed of a polyolefin fraction, a non-polyolefin polymer fraction and non-polymer contaminants. Within the polyolefin fraction, HDPE (High-Density Polyethylene), LDPE (Low-Density Polyethylene), PP (Polypropylene) and PS (Polystyrene) are polyolefins that are typically found in postconsumer wastes. HDPE is a type of plastic known for its strength and durability. It is commonly used in products like milk jugs, detergent bottles, and piping. LDPE is a more flexible and softer plastic, used in products like plastic bags, squeeze bottles, and some types of packaging. PP is a versatile plastic used in products like food containers, automotive parts, and textiles. In addition, PS is a plastic that is used in products like disposable cups, plastic food containers, and packaging materials (like Styrofoam).

[0009] Typical non-polyolefin polymers among other in such post-consumer waste, for instance collected from recycling or collected waste that has been used and discarded by consumers, are polymers of the group consisting of Polyvinyl Chloride (PVC), Acrylonitrile Butadiene Styrene (ABS), Polyethylene Terephthalate (PET), Polyamide (PA), Ethylene Vinyl Alcohol (EVOH), Ethylene Vinyl Acetate (EVA), Nylon (Polyamide, PA6; PA6,6), Polycarbonate (PC), Polyoxymethylene (POM, Acetal), Polyurethane (PU), Polyether Ether Ketone (PEEK) and Polyvinylidene Fluoride (PVDF) or mixtures thereof. Polyvinyl Chloride (PVC) is frequently used in construction (pipes, windows) and medical applications, becoming waste from these sectors. PET from beverage and food packaging constitutes a large portion of the global recycling and waste stream due to its widespread use in bottles. Polyamide (PA), Ethylene Vinyl Alcohol (EVOH) and Ethylene Vinyl Acetate (EVA) are often found in multilayer packaging applications. Polyurethane (PU) and ABS are present in long-lasting goods like furniture, electronics, and automotive parts, contributing to both household and industrial waste.

[0010] Non-polymer contaminants can also be present in the post-consumer waste feedstock as organic or inorganic compounds, which were for example added in the manufacturing process (e.g., pigments, stabilizers, antistatic agents, slip agents, lubricants, flame retardants, fillers, antioxidants, plasticizers, etc.) or arise from the post-consumer phase (food residues). There is a problem in the art to depolymerize polyolefin into hydrocarbon products when such polyolefin materials are mixed with non-polyolefin constituents in mixtures of reclaimed plastic or post-consumer waste. Acid catalysis can be used in direct contact with the polyolefin fraction to facilitate depolymerization, giving a molecular weight reduction at reduced temperatures compared to thermal cracking. However, depolymerization of a polyolefin fraction mixed with non-polyolefin constituents is complicated as the active sites of the catalyst are deactivated due to the direct contact with non-polyolefin constituents.

[0011] SUMMARY OF THE INVENTION

[0012] Present invention solves this problem by implementing a pretreatment prior to the depolymerization, comprising the steps 1) stirring or agitating the feedstock in a polar solvent (extractant) at a temperature from the range of 175°C to 300°C under increased pressure conditions, to transform the mix in immiscible phases of i) polyolefin polymers in a non-dissolved molten state and ii) non-polyolefin constituents dispersed in the extractant phase, and optionally iii) solid particles sediment dispersed in the liquid, 2) separation of the immiscible phases, and 3) heating the separated upgraded feedstock in the presence of a catalyst at a temperature in the range of 200°C - 700°C, preferably at temperatures in the range of 250 - 500°C and in an atmosphere with not more than 5, or not more than 4, or not more than 3, or not more than 2, or not more than 1, or not more than 0.5, in each case wt % of oxygen gas or it concerns an atmosphere having an oxygen content below 5 %, or below 4%, or below 3, or below 2% or below 1% of the total interior gas volume in the reactor or in the absence of O2.

[0013] The present invention overcomes the problems encountered in in-situ catalytic conversion (i.e., direct contact between the catalyst and the plastic feedstock; catalytic pyrolysis in the melt) of the polyolefin polymer fraction in reclaimed plastic or post-consumer waste plastic feedstock to hydrocarbon products of the class alkanes, alkenes, naphthenes, aromatics, or a mixture thereof, by pre-treating the feedstock composed of polyolefin polymers in mixtures with non-polyolefin constituents.

[0014] The present invention solves the problems of the related art of overcoming catalyst deactivation in chemical recycling of plastic waste by a stepwise process where a pretreatment step is first applied to the plastic feedstock, including stirring or agitating the feedstock in a polar solvent at elevated temperature (175 - 300 °C) and elevated pressure to access the non- polyolefin fraction from the melt. The second step comprises the separation of the cleaner polyolefin melt from the non-polyolefin fraction that is dispersed in the solvent. The third and final step comprises the catalytic molecular weight reduction of the cleaner polyolefin melt via direct contact with a catalyst. The consecutiveness of the steps, where non-polyolefin constituents are removed from the polyolefin fraction in the first two steps, protects the catalyst from deactivation, thus leading to more effective catalytic actions in the final step to selectively produce higher quality hydrocarbon products for the chemical industry.

[0015] In accordance with the purpose of the invention, as embodied and broadly described herein, the invention is broadly drawn to a method of producing hydrocarbon products of the class of alkanes, alkenes, naphthenes, aromatics, or mixtures thereof, from polyolefin polymers comprised a mixture with other non-polyolefin constituents, the method comprising the steps 1) a pretreatment of stirring or agitating the feedstock in a polar solvent under increased pressure conditions at a temperature in the range of 175 - 300 °C and preferably of 220 - 270 °C, thereby transforming the mix in immiscible phases of i) polyolefin polymers in a non-dissolved molten state and ii) other non-polyolefin constituents dispersed in the solvent and optionally iii) solid particles, 2) separation of the immiscible phases, and 3) heating the separated polyolefin polymers in the presence of a catalyst at a temperature in the range of 200 - 700 °C, preferably at temperatures in the range of 250 - 500 °C and in an atmosphere with not more than 5, or not more than 4, or not more than 3, or not more than 2, or not more than 1, or not more than 0.5, in each case wt % of oxygen gas or it concerns an atmosphere having an oxygen content below 5 %, or below 4%, or below 3, or below 2% or below 1% of the total interior gas volume in the reactor or in the absence of O2

[0016] The invention provides a method of producing hydrocarbon products from a feedstock comprising polyolefin polymers and non-polyolefin constituents, whereby the method comprises the steps: 1) a pretreatment of stirring or agitating the feedstock in a polar solvent under increased pressure conditions at a temperature in the range of 175 to 300°C, thereby transforming the mix into at least two immiscible liquid phases comprising: i) a first liquid phase comprising the polyolefin polymers in a non-dissolved molten state, and ii) a second liquid phase comprising the polar solvent having the non-polyolefin constituents dispersed or dissolved therein, 2) separating the first liquid phase from the second liquid phase; and 3) heating the separated first liquid phase comprising the polyolefin polymers in the presence of a catalyst in an atmosphere having an oxygen content below 5 percent based on the total interior volume of the reactor, and at a temperature in the range of 200 to 700°C.

[0017] This embodiment of the invention advantageously comprises that the polar solvent is an aqueous medium or that the polar solvent is water, an alcohol or a mixture thereof or that the polar solvent is an alcohol in water and the volume of the water is 99% to 50% of the volume of the alcohol. It is also desirable that the alcohol is of the group consisting of methanol, ethanol, propanol and butanol.

[0018] With respect to the polar solvent to the polymer ratio, it is noted that it is advantageous if the ratio of polar solvent on the one hand to the polymer on the other hand is in the range of 20 to 5 mL / g, and preferably 12 to 8 mL / g. The object of the present invention is achieved by means of pressurizing the reaction vessel. Hereby the pressure condition of step 1) is regulated around a predefined set-point by the introduction / extraction of gas by means of the pressurization system or it is formed by the heating in a pressure reactor and the pressure inside the reaction vessel is further regulated around a predefined set-point by the introduction / extraction of gas by means of the pressurization system. In another aspect, the present invention provides that the pressure reactor is a mixer-extruder or that the pressure reactor is a twin screw extruder. A further disadvantageous aspect is also that the starting pressure condition in step 1) is between 0.1 to 4 mega Pascal (MPa) and preferably between 0,2 to 2 MPa. According to the present invention there is provided absence of O2 (oxygen below 5 part per million (ppm) and preferably below 1 part per million (ppm)) in the atmosphere of the reaction vessel during the pretreatment step 1).

[0019] In a practical embodiment, the pretreatment step 1) is under an inert atmosphere of argon or nitrogen gas, preferably nitrogen gas or it is under a hydrogen atmosphere. Some of the techniques described above may be embodied as in step 2 the phases are separated under flow over a mesh pad liquid-liquid coalesce or a flow in a hydrocyclone or in step 2 the melted state polyolefin polymer is separated by an electrostatic coalescer or in step 2 after the stirring or agitating the mixture is remained still or undisturbed for gravity separation in a decanter or a plate separator or in step 2 the melted state polyolefin polymer is separated by counter-current separation, preferably countercurrent extruder separation.

[0020] In another aspect, the present invention provides that the catalyst of the above described method is an acid catalyst for instance the acid catalyst is solid acid catalyst or the acid catalyst is a crystalline or non-crystalline aluminosilicate material, preferably an acid zeolite or the acid catalyst is a homogeneous acid catalyst, such as Friedel-Crafts catalysts, Brpnsted acids, and Lewis acids or the acid catalyst is a solid bifunctional catalyst whereby an acidic component is configured to promote acid-catalysed reactions including isomerization and cracking, and a metallic component is configured to promote metal-catalysed reactions including hydrogenation and dehydrogenation for instance such metallic component can comprise a transition metal selected from the group consisting of Platinum (Pt), Palladium (Pd), Ruthenium (Ru), Rhodium (Rh), Nickel (Ni), Cobalt (Co), Molybdenum (Mo), Tungsten (W), Iron (Fe), and Copper (Cu) or combinations thereof, in a dispersed phase over a suitable support to enhance metal dispersion and catalytic activity. In an advantageous embodiment, the method according to the present invention the bifunctional catalyst is configured to perform combined hydrocracking, hydro-isomerization, or hydro-dealkylation processes to convert the polyolefin polymer feedstock into saturated C5-C20 hydrocarbons which includes gasoline-range or diesel-range products with an optimized selectivity towards isomerized alkanes.

[0021] As discussed above, the method of producing hydrocarbon products according to the present invention is from a feedstock comprising polyolefin polymers and non-polyolefin constituents. Hereby the hydrocarbon products can be alkanes, alkenes, naphthenes, aromatics, and mixtures thereof, with a molecular weight lower than the original polyolefin polymer. The feedstock can be any of these. It is a mixture comprising polyolefin polymers, nonpolyolefin polymers and non-polyolefin (in)organic constituents. The polyolefin polymers of the plastic feedstock are of a group consisting of PE (Polyethylene), PP (Polypropylene) and PS (Polystyrene), or mixtures thereof. Hereby the PE (Polyethylene) can be of the group consisting of a HDPE (High- Density Polyethylene), LDPE (Low-Density Polyethylene), LLDPE (Linear Low- Density Polyethylene), MDPE (Medium-Density Polyethylene), VLDPE (Very Low-Density Polyethylene) and UHMWPE (Ultra-High-Molecular-Weight Polyethylene) or a combination thereof. Hereby the PP (Polypropylene) can be of the group consisting of IPP (Isotactic Polypropylene), SPP (Syndiotactic Polypropylene), APP (Atactic Polypropylene), COPP (Copolymers of Polypropylene), or a combination thereof. Hereby the PS (Polystyrene) can be of the group consisting of IPS (Isotactic Polystyrene), SPS (Syndiotactic Polystyrene), APS (Atactic Polystyrene), COPS (Copolymers of Polystyrene), or a combination thereof.

[0022] In the method described hereabove the non-polyolefin polymers can comprise a compound selected of the group consisting of PET (Polyethylene Terephthalate), PVC (Polyvinyl Chloride), PC (Polycarbonate), PA (Polyamide, commonly known as Nylon), PMMA (Polymethyl Methacrylate, also known as Acrylic), ABS (Acrylonitrile Butadiene Styrene), PBT (Polybutylene Terephthalate), PLA (Polylactic Acid) and PU (Polyurethane), thermoplastic polyurethane elastomers, polyamides polymethacrylates, polyvinylidene fluoride, polycarbonates, polyesters, polystyrene, polyacrylonitrile, acrylonitrile-butadiene-styrene copolymer, or a combination thereof.

[0023] According to the method present invention there is provided that the non- polyolefin (in)organic constituents can comprise (in)organic salts and / or (in)organic additives selected of the group consisting of pigments, stabilizers, antistatic agents, slip agents, lubricants, flame retardants, fillers, antioxidants, plasticizers or contaminants coming from the use phase. Another aspect is the method present invention providing that the feedstock is a mixture of a reclaimed plastic or post-consumer waste.

[0024] Yet another aspect is the method present invention providing that the feedstock is a post-consumer mixture with a polyolefin polymer fraction, nonpolyolefin polymer contaminants fraction, and non-polymer (in)organic constituents fraction whereby the polyolefin polymer fraction comprises a compound of PE (Polyethylene), PP (Polypropylene), PS (Polystyrene), or mixtures thereof.

[0025] Yet another aspect is the method present invention providing that feedstock is a post-consumer mixture with a polyolefin polymer fraction, non-polyolefin polymer contaminants fraction, and non-polymer (in)organic constituents fraction whereby the non-polyolefin polymer contaminants comprise a compound selected of the group consisting of PET (Polyethylene Terephthalate), PVC (Polyvinyl Chloride), PC (Polycarbonate), PA (Polyamide, commonly known as Nylon), PMMA (Polymethyl Methacrylate, also known as Acrylic), ABS (Acrylonitrile Butadiene Styrene), PBT (Polybutylene Terephthalate), PI_A (Polylactic Acid) and PU (Polyurethane), thermoplastic polyurethane elastomers, polyamides polymethacrylates, polyvinylidene fluoride, polycarbonates, polyesters, polystyrene, polyacrylonitrile, acrylonitrile-butadiene-styrene copolymer, or a combination thereof.

[0026] Yet another aspect is the method present invention providing that feedstock is a post-consumer mixture with a polyolefin polymer fraction, non-polyolefin polymer contaminants fraction, and non-polymer (in)organic constituents fraction whereby the non-polymer (in)organic constituents comprise (in)organic salts and / or (in)organic additives.

[0027] Detailed Description

[0028] The present invention will become more fully understood from the detailed description given herein below and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention.

[0029] As used herein, "oxygen removal" includes (i) reducing oxygen concentration by displacement / dilution, (ii) separating oxygen by adsorption or membranes, (iii) converting oxygen by reaction / combustion, (iv) binding oxygen by reversible oxygen carriers, (v) removing oxygen by cryogenic separation, and / or (vi) oxygen reduction in biological or integrated purge / separator systems.

[0030] Present invention concerns method of producing hydrocarbon products from a feedstock comprising polyolefin polymers and non-polyolefin constituents, whereby the method comprises the steps: 1) a pretreatment of stirring or agitating the feedstock in a polar solvent under increased pressure conditions at a temperature in the range of 175 to 300°C, thereby transforming the mix into at least two immiscible liquid phases comprising:!) a first liquid phase comprising the polyolefin polymers in a non-dissolved molten state, and ii) a second liquid phase comprising the polar solvent having the non-polyolefin constituents dispersed or dissolved therein, 2) separating the first liquid phase from the second liquid phase; and 3) heating the separated first liquid phase comprising the polyolefin polymers in the presence of a catalyst in an atmosphere having an oxygen content below 5 percent based on the total interior volume of the reactor, and at a temperature in the range of 200 to 700°C.

[0031] In an embodiment or in combination with any of the embodiments mentioned herein, the separated first liquid phase comprising the polyolefin polymers in the presence of a catalyst is in a reactor heated in an atmosphere that is in the absence of oxygen or substantially free of oxygen or in an atmosphere that contains less oxygen relative to ambient air. In an embodiment or in combination with any of the embodiments mentioned herein, such atmosphere may comprise not more than 5, or not more than 4, or not more than 3, or not more than 2, or not more than 1, or not more than 0.5, in each case wt % of oxygen gas or it concerns an atmosphere having an oxygen content below 5 %, or below 4%, or below 3, or below 2% or below 1% of the total interior gas volume in the reactor, for instance inert gas atmosphere, such as nitrogen, carbon dioxide. Hereby absence of 02 is oxygen below 5 part per million (ppm) and preferably below 1 part per million (ppm)). Such gasses suitable for the present invention are available as for instance PHARGALIST 1 (5 ppm 02), AlphaGaz™ 1 (<2 ppm 02), AlphaGaz 2 N2 (<0.1 ppm 02), Industrial N2 (<100 ppm 02), ALIGAL™ 2 (<30 ppm 02), ALIGAL™ 1 (<20 ppm 02), ALIGAL™ 13 (<20 ppm 02), ALIGAL™ 12 (<20 ppm 02), Nitrogen 3.0 (<1000 ppm 02), Nitrogen 5.0 (<5 ppm 02), CO2 food grade (<100 ppm 02), Carbon dioxide 2.7(<500 ppm 02), Carbon dioxide 4.0 (<15 ppm 02) and Carbon dioxide 4.5(<15 ppm 02).

[0032] Such suitable atmospheres can also be obtained by oxygen removal. For instance, the atmosphere in the reactor made inert by introducing an inert gas rich stream (e.g., nitrogen-rich) and withdrawing a waste gas stream containing oxygen, optionally using phased concentration purging (increasing inert concentration during introduction) until the oxygen concentration is below these predetermined oxygen thresholds. Or an inert gas rich stream is produced on-site by a pressure swing adsorption (PSA) nitrogen generator with upstream air treatment (filtration / drying) and delivered to the reactor headspace / volume as a blanketing / inerting gas that at least has not more than 5 wt % oxygen. Furthermore, recirculated atmosphere stream can be contacted with a reversible oxygen sorbent that selectively and reversibly binds oxygen, and the sorbent is regenerated by heating and / or reducing oxygen partial pressure, thereby maintaining low oxygen levels during steady-state operation.

[0033] FIGURE 1 shows the DSC signals for Virgin (A) and Waste (B) polyolefins in two panels (1A and IB) of differential scanning calorimetry (DSC) experiments on virgin and waste polyolefin feedstock to determine the melting of a polymer feedstock. Panel A shows the DSC signals for virgin polymers; these have narrow melting peaks due to the high purity of the materials. These melting peaks are used as an identification of polymer types in waste feedstock. Panel B shows the DSC signals for the waste polyolefin feedstock. In these DSC signals, more melting peaks can be differentiated due to imperfect sorting of different polyolefin polymers. To obtain the feedstock in a molten phase, the minimal temperature for the pre-treatment is taken as the peak end of the highest melting polymer (i.e., PP at 175°C). The DSC measurements were carried out with a Thermal Analysis System TGA / DSC 3+ / LF (Mettler-Toledo) at a temperature range of 25 - 225°C with a heating rate of 10°C / min, with gas flow of 90 mL Nz / min.

[0034] FIGURE 2 shows the TGA breakdown curves of Virgin (A) and Waste (B) polyolefin in two panels 2A and 2B to determine the degradation temperature of the polymer type. In both panels A and B, it is demonstrated that there are substantial differences in the thermal breakdown of polymers. Furthermore, the main breakdown region for both virgin and waste polyolefin is in the region between 375 - 475 °C. To avoid the polymer feedstock to break down during the pre-treatment step, the maximal temperature for the pre-treatment is taken as the onset temperature of the least thermally stable polyolefin polymer (i.e., PS at 300°C). The TGA measurements were carried out with a Thermal Analysis System TGA / DSC 3+ / LF (Mettler-Toledo) at a temperature range of 25 - 600°C with a heating rate of 10°C / min, with gas flow of 90 mL Nz / min.

[0035] FIGURE 3 shows the thermal and catalytic breakdown curves of Virgin (A) and Waste (B) LDPE in two panels 3A and 3B. Panel A shows the potential impact of acid catalysis in in-situ catalytic pyrolysis of virgin LDPE feedstock for example catalyst SIRAL40HPV, hereafter named ASA

[0040] HPV. The catalytic breakdown curve starts to decrease at much lower temperatures compared to the case without the addition of the ASA

[0040] HPV catalyst. Panel B shows the impact of the use of polluted waste LDPE feedstock with the example catalyst ASA

[0040] HPV. Here, the positive effects of the acid catalyst as observed for virgin LDPE feedstock almost completely disappears. FIGURE 4 is a visual representation of the activity restoration parameter AT activity restoration parameter for ASA

[0040] HPV (A) and HZSM-5(25) (B) in two panels 4A and 4B. This parameter is calculated as the difference in the temperature between the optimal case (i.e., catalytic pyrolysis of virgin LDPE feedstock) and the catalytic pyrolysis of the (pre-treated) waste feedstock. The temperature parameter corresponds to the 50% weight loss in the temperature region between 125 - 575°C.

[0036] The lower the value for AT, the more efficient the pre-treatment procedure is evaluated. The AT value is calculated as:

[0037] AT = T°5Oo / oCatalytic waste) — T°5Oo / o(Catalytic virgin)

[0038] FIGURE 5 represents a two-dimensional scatterplot in which the catalysts are presented based on their activity (represented by ATA) and stability (represented by the coke content as wt.% of the feed). This data has been collected through a small-scale screening approach using Thermogravimetric Analysis (TGA), where virgin LDPE feedstock was mixed with the heterogeneous catalyst in a 3 to 1 ratio, to reach a total sample mass of 20 mg. The sample was subjected to a heating profile composed of a pyrolysis segment under N2 from RT - 600 °C and a coke segment under O2 from 150 - 900 °C. Both segments show weight loss events that are used to attribute quantitative parameters about the catalyst activity and stability.

[0039] The ATA value and the coke content as wt.% of the feed are calculated as:

[0040] Where T°so% (Catalytic / Thermal virgin feedstock) stands for the temperature at which 50% of the mass loss of the pyrolysis segment under N2 is reached; mend stands for the mass at the end of the TGA method (i.e., only catalyst); mi5o°c stands for the mass before the start of the coke segment under O2 gas and mstart stands for the mass at the beginning of the TGA method (i.e., catalyst and plastic feedstock).

[0041] FIGURE 6 represents a two-dimensional scatterplot in which the catalysts are presented based on their activity (represented by ATA) and stability (represented by the coke content as wt.% of the feed). This data has been collected through a small-scale screening approach using Thermogravimetric Analysis (TGA), where virgin PP feedstock was mixed with the heterogeneous catalyst in a 3 to 1 ratio, to reach a total sample mass of 20 mg. The sample was subjected to a heating profile composed of a pyrolysis segment under N2 from RT - 600 °C and a coke segment under O2 from 150 - 900 °C. Both segments show weight loss events that are used to attribute quantitative parameters about the catalyst activity and stability. The TA value and the coke content as wt.% of the feed are calculated as: ermal virgin) °C 100 %

[0042] Where T°so% (Catalytic / Thermal virgin feedstock) stands for the temperature at which 50% of the mass loss of the pyrolysis segment under N2 is reached; mend stands for the mass at the end of the TGA method (i.e., only catalyst); mi5o°c stands for the mass before the start of the coke segment under O2 gas and mstart stands for the mass at the beginning of the TGA method (i.e., catalyst and plastic feedstock).

[0043] FIGURE 7 represents a two-dimensional scatterplot in which the catalysts are presented based on their activity (represented by ATA) and stability (represented by the coke content as wt.% of the feed). This data has been collected through a small-scale screening approach using Thermogravimetric Analysis (TGA), where virgin PS feedstock was mixed with the heterogeneous catalyst in a 3 to 1 ratio, to reach a total sample mass of 20 mg. The sample was subjected to a heating profile composed of a pyrolysis segment under N2 from RT - 600 °C and a coke segment under O2 from 150 - 800 °C. Both segments show weight loss events that are used to attribute quantitative parameters about the catalyst activity and stability.

[0044] The ATA value and the coke content as wt.% of the feed are calculated as: ermal virgin) °C 100 %

[0045] Where T°so% (Catalytic / Thermal virgin feedstock) stands for the temperature at which 50% of the mass loss of the pyrolysis segment under N2 is reached; mend stands for the mass at the end of the TGA method (i.e., only catalyst); mi5o°c stands for the mass before the start of the coke segment under O2 gas and mstart stands for the mass at the beginning of the TGA method (i.e., catalyst and plastic feedstock).

[0046] FIGURE 8 shows the effects of pre-treatment procedures on polluted LDPE using 100vol. % H2O in three panels 8A, 8B and 80 for the example catalyst ASA

[0040] HPV (SIRAL

[0040] HPV, SASOL). Panel A shows the AT value for the non-treated waste LDPE feedstock. Panel B shows the evolution of the AT value as a function of the pre-treatment temperature for the case of 100vol. % H2O extractant compositions. Panel C shows the AT for the optimal case without deactivation of the solid acid catalyst (ASA

[0040] HPV). Relevant reaction parameters displayed in panel B. The AT value is calculated as:

[0047] AT = T°sOo / o(C at aly tic waste) — T°5Oo / o(Catalytic virgin )

[0048] FIGURE 9 shows the effects of pre-treatment procedures on polluted LDPE using 100vol. % H2O in three panels 9A, 9B and 90 for the example catalyst HZSM-5(25) (CBV5524G, Zeolyst). Panel A shows the AT value for the nontreated waste LDPE feedstock. Panel B shows the evolution of the AT value as a function of the pre-treatment temperature for the case of 100vol. % H2O extractant compositions. Panel C shows the AT for the optimal case without deactivation of the solid acid catalyst (HZSM-5(25)). Relevant reaction parameters displayed in panel B. The AT value is calculated as: AT = T°5Oo / oCataly tic waste) — T°5Oo / o(Catalytic virgin)

[0049] FIGURE 10 shows the effects of pre-treatment procedures on polluted LDPE using 50 / 50vol.% hhO / n-butanol in three panels 10A, 10B and IOC for the example catalyst ASA

[0040] HPV (SIRAL

[0040] HPV, SASOL).. Panel A shows the AT value for the non-treated waste LDPE feedstock. Panel B shows the evolution of the AT value as a function of the pre-treatment temperature for the case of 50 / 50vol.% hhO / n-butanol extractant compositions. Panel C shows the AT for the optimal case without deactivation of the solid acid catalyst (ASA

[0040] HPV).

[0050] Relevant reaction parameters displayed in panel B. The AT value is calculated as:

[0051] AT = T°5Oo / o(Catalytic waste) — T°5Oo / o(Catalytic virgin)

[0052] FIGURE 11 shows the effects of pre-treatment procedures on polluted LDPE using 50 / 50vol.% hhO / n-butanol in three panels 11A, 11B and 11C for the example catalyst HZSM-5(25) (CBV5524G, Zeolyst). Panel A shows the AT value for the non-treated waste LDPE feedstock. Panel B shows the evolution of the AT value as a function of the pre-treatment temperature for the case of 50 / 50vol. % hhO / n-butanol extractant compositions. Panel C shows the AT for the optimal case without deactivation of the solid acid catalyst (HZSM- 5(25)). Relevant reaction parameters displayed in panel B. The AT value is calculated as:

[0053] AT = T°5Oo / o(Catalytic waste) — T°5Oo / o(Catalytic virgin)

[0054] FIGURE 12 shows the effects of pre-treatment procedures on polluted PS using 100vol. % H2O in three panels 12A, 12B and 12C for the example catalyst ASA

[0070] HPV (SIRAL

[0070] HPV, SASOL). Panel A shows the AT value for the non-treated waste LDPE feedstock. Panel B shows the evolution of the AT value as a function of the pre-treatment temperature for the case of 50 / 50vol. % hhO / n-butanol extractant compositions. Panel C shows the AT for the optimal case without deactivation of the solid acid catalyst (ASA

[0070] HPV). Relevant reaction parameters displayed in panel B. The AT value is calculated as: AT = T°5Oo / oCataly tic waste) — T°5Oo / o(Catalytic virgin )

[0055] FIGURE 13 shows the effects of pre-treatment procedures on polluted PS using 100vol. % H2O in three panels 12A, 12B and 12C for the example catalyst FER(9) (HSZ720NHA, TASOH). Panel A shows the AT value for the non-treated waste LDPE feedstock. Panel B shows the evolution of the AT value as a function of the pre-treatment temperature for the case of 50 / 50vol. % HzO / n-butanol extractant compositions. Panel C shows the AT for the optimal case without deactivation of the solid acid catalyst (FER(9)) Relevant reaction parameters displayed in panel B. The AT value is calculated as:

[0056] AT = T°5Oo / o(Catalytic waste) — T°5Oo / o(Catalytic virgin )

[0057] FIGURE 14 shows the reactor setup for lab scale verification of the small scale TGA trends in two panels 14A and 14B with the experimental setup for the lab scale performance tests. Panel 14A shows the process conditions of thermocouple furnace temperature in °C and the stirring speed profile in RPM as functions of time. Panel 14B shows a schematic representation of the reactor setup. Volatilized compounds leave the reactor to the condenser after which condensates end up in the liquid collector. Non-condensable products are collected in a gas bag.

[0058] FIGURE 15 shows the broad product selectivity (i.e., gas-, liquid- and solid fractions) for the two example catalysts ASA

[0040] HPV (SIRAL

[0040] HPV, SASOL) and HZSM-5(25) (CBV5524G, Zeolyst) for non-treated, 100vol. % H2O pretreated and 50 / 50vol.% FhO / n-butanol pre-treated polluted LDPE waste feedstocks. The pre-treatment conditions used to produce the feedstocks are 2 hours, 250°C, 700RPM, 7g / 70mL plastic / extractant. Afterwards, the pretreated waste plastic was rotor milled for use in the lab scale reactor.

[0059] FIGURE 16 demonstrates improved hydrocracking on a pretreated PCW PE (15 g) with a Pt / CBV901 bifunctional catalyst (1.5 g).

[0060] DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION The following detailed description of the invention refers to the accompanying drawings. The same reference numbers in different drawings identify the same or similar elements. In addition, the following detailed description does not limit the invention. Instead, the scope of the invention is defined by the appended claims and equivalents thereof.

[0061] Several documents are cited throughout the text of this specification. Each of the documents herein (including any manufacturer's specifications, instructions etc.) are hereby incorporated by reference; however, there is no admission that any document cited is indeed prior art of the present invention.

[0062] The present invention will be described with respect to particular embodiments and with reference to certain drawings but the invention is not limited thereto but only by the claims. The drawings described are only schematic and are non-limiting. In the drawings, the size of some of the elements may be exaggerated and not drawn to scale for illustrative purposes. The dimensions and the relative dimensions do not correspond to actual reductions to practice of the invention.

[0063] Furthermore, the terms first, second, third and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein.

[0064] It is to be noticed that the term "comprising", used in the claims, should not be interpreted as being restricted to the means listed thereafter; it does not exclude other elements or steps. It is thus to be interpreted as specifying the presence of the stated features, integers, steps or components as referred to, but does not preclude the presence or addition of one or more other features, integers, steps or components, or groups thereof. Thus, the scope of the expression "a device comprising means A and B" should not be limited to the devices consisting only of components A and B. It means that with respect to the present invention, the only relevant components of the device are A and B.

[0065] Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment, but may. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner, as would be apparent to one of ordinary skill in the art from this disclosure, in one or more embodiments.

[0066] Similarly, it should be appreciated that in the description of exemplary embodiments of the invention, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding the understanding of one or more of the various inventive aspects. This method of disclosure, however, is not to be interpreted as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive aspects lie in less than all features of a single foregoing disclosed embodiment. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.

[0067] Furthermore, while some embodiments described herein include some but not other features included in other embodiments, combinations of features of different embodiments are meant to be within the scope of the invention, and form different embodiments, as would be understood by those in the art. For example, in the following claims, any of the claimed embodiments can be used in any combination.

[0068] In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the invention may be practiced without these specific details. In other instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description. Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only.

[0069] Each and every claim is incorporated into the specification as an embodiment of the present invention. Thus, the claims are part of the description and are a further description and are in addition to the preferred embodiments of the present invention. Each of the claims set out a particular embodiment of the invention. The following terms are provided solely to aid in the understanding of the invention.

[0070] Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

[0071] In one aspect of the invention, the feedstock is a mixture of a reclaimed plastic or post-consumer waste, composed of a mixture of a polyolefin fraction and non-polyolefin constituents. The polyolefin can be of the of the group consisting of PP (Polypropylene), IPP (Isotactic Polypropylene), SPP (Syndiotactic Polypropylene), APP (Atactic Polypropylene) and COPP (Copolymers of Polypropylene) or a combination thereof, or the polyolefin can be a PE (Polyethylene) of the group consisting of a HDPE (High-Density Polyethylene), LDPE (Low-Density Polyethylene), LLDPE (Linear Low-Density Polyethylene), MDPE (Medium-Density Polyethylene), VLDPE (Very Low- Density Polyethylene) and UHMWPE (Ultra-High-Molecular-Weight Polyethylene) or a combination thereof, or the polyolefin can be a PS (Polystyrene), IPS (Isotactic Polystyrene), SPS (Syndiotactic Polystyrene), APS (Atactic Polystyrene), or a mixture thereof.

[0072] In another aspect of the invention, the non-polyolefin constituents can be polymers of the group of PET (Polyethylene Terephthalate), PVC (Polyvinyl Chloride), PC (Polycarbonate), PA (Polyamide, commonly known as Nylon), PMMA (Polymethyl Methacrylate, also known as Acrylic), ABS (Acrylonitrile Butadiene Styrene), PBT (Polybutylene Terephthalate), PLA (Polylactic Acid) and PU (Polyurethane), Ethylene Vinyl Alcohol (EVOH), Ethylene Vinyl Acetate (EVA), thermoplastic polyurethane elastomers, polyamides polymethacrylates, polyvinylidene fluoride, polycarbonates, polyesters, polyacrylonitrile, acrylonitrile-butadiene-styrene copolymer, or a combination thereof.

[0073] In another aspect of the invention, the feedstock includes food-packaging plastics comprising of polymers specifically selected for their safety, durability, and ability to protect food from contamination, moisture, and other environmental factors. For example abundant food packaging plastics are polyethylene terephthalate (PET) that is commonly used in beverage bottles and food containers, polypropylene (PP) that is commonly used in food containers, yogurt cups, and microwave-safe dishes, and polystyrene (PS): Used in disposable cutlery, plates, and foam food containers. However, the polyolefin, low-density polyethylene (LDPE) is also used in plastic wraps and squeezable bottles. A combination of materials in multilayers can occur, comprised of possible mixtures of PE, PP, PS, and / or PET, with customized tie layers comprised of nitrocellulose or PUR. based colourants, EVA, EVOH, and / or PA(6). Reclaimed plastics (or recycled plastics) contains materials that have been recovered and reprocessed from waste products, such as postconsumer waste or industrial scraps. These plastics are processed into new materials and products, reducing the need for virgin plastic production, but are subjected to strict legislation in order to be used for food-contact applications. Common reclaimed plastics are Recycled PET (rPET) for instance from reclaimed PET bottles, used in clothing, carpeting, and new packaging or the recycled polypropylene (rPP), for instance used in automotive parts, containers, and packaging. However also recycled polyolefins are used such as recycled HDPE for instance used in products like outdoor furniture, piping, and new non-food application bottles. They can be all part of the postconsumer waste.

[0074] In another aspect of the invention, the non-polyolefin constituents can be organic or inorganic compounds, which were for example added in the manufacturing process (e.g. pigments, flame retardants, fillers, antioxidants, plasticizers, processing aids, adhesive materials, papers, or combinations thereof) or arise from the post-consumer phase (e.g. food residues, oil residues, decomposition products of the polymer, or combinations thereof).

[0075] In one aspect of the invention, the hydrocarbon products consists of the group of alkanes, alkenes, naphthenes, aromatics, or mixtures thereof, and can be used for the manufacture of base chemicals for the chemical industry, for example naphtha, light olefins (ethylene, propylene, butenes), fuels, plastics, and synthetic fibres, lubricants, carbon (e.g. carbon nanotubes), hydrogen.

[0076] In one aspect of the invention, in step 1, a pressure reactor is a closed vessel designed to perform chemical reactions under elevated pressure for instance to facilitate reactions that occur at conditions different from ambient. These conditions can increase reaction rates, improve yields, or allow reactions that are not feasible at atmospheric pressure. An extruder can function as a pressure reactor when modified for pressure build-up as the confined geometry of an extruder, combined with its screw mechanism, can generate significant pressure, especially in twin-screw extruders. Extruders are equipped with heaters and screw designs that allow for thorough mixing and controlled thermal input, making them suitable for certain chemical processes. Particular suitable for such processes are the twin-screw extruders.

[0077] In embodiments of methods of the present invention the starting pressing at room temperature is 30 bar for experiments performed between 25-250°C, for experiments performed at 300°C a starting pressure of 45 bar is applied. For example with a starting pressure of 30 bar at room temperature, and a reacting temperature at 250°C, the final pressure is typically around 80 bar. An increased pressure in the reactor above the vapor pressure of water prevents boiling of the water.

[0078] , but this value varies if we take 200°C or when we start at 45 bar and go to 300°C.

[0079] Typically the starting pressure is 2.5 - 4.5 MPa, more typically 2.8 - 3.3 MPa, whereby the operating pressure is above the autogenous pressure at the operating temperature. This pressure inside the reaction vessel can be regulated around a predefined set-point by the introduction / extraction of gas by means of the pressurization system.

[0080] In another aspect of the invention, in step 1 the polar solvent is an aqueous phase consisting of water, alcohol (e.g. methanol, ethanol, propanol, butanol, etc.), or a mixture thereof.

[0081] In still another aspect of the invention, step 1 is performed in an atmosphere with not more than 5, or not more than 4, or not more than 3, or not more than 2, or not more than 1, or not more than 0.5, in each case wt % of oxygen gas or it concerns an atmosphere having an oxygen content below 5 %, or below 4%, or below 3, or below 2% or below 1% of the total interior gas volume in the reactor or in the absence of O2. The preferred atmosphere is N2.

[0082] In one aspect of the invention, in step 2 the phases are separated under flow over a mesh pad liquid-liquid coalesce or a flow in a hydrocyclone, or in in step 2 the melted state polyolefin polymers is separated by an electrostatic coalesce, or in step 2 after the stirring or agitating the mixture is remained still or undisturbed for gravity separation for instance in a decanter or a plate separator.

[0083] In one aspect of the invention, in step 3 the catalysts belong to, but are not limited to, the class of heterogeneous catalyst, wherein particular interest is given to aluminosilicate and aluminosilicophosphate type catalysts (e.g. instance zeolites and amorphous silica-alumina, ASA)); acidic solid oxides; acidic silicoaluminophosphates; Group IVB, VB, and VIB metal oxides; hydroxide or free metal forms of Group VIII metals; and any combination thereof. Zeolite topologies of interest are for example characterized by a 10 membered-ring pore size (e.g. MFI, FER, TON, MEL, MTT, AEL, MWW, HEU) or 12 membered-ring pore size (e.g. FAU, *BEA, MOR.). Other catalysts can belong to, but are not limited to homogeneous acid catalysts, such as Friedel- Crafts catalysts, Brpnsted acids, and Lewis acids; acidic resins; and any combination thereof. As regards the solid acid catalyst, its structure is based on an organic or inorganic support, Brpnsted acid or Lewis acid is attached to the organic or inorganic support. The organic carrier may be a polymeric carrier including polystyrene, polyamide, polyethylene glycol, and the like. The inorganic support may be based on silica, alumina, zeolites, and the like. As the catalytically active component chemically attached to the support, the acid may be Brpnsted acids, including sulphonic acids, phosphoric acids, and the like; or a Lewis acid comprising a metal ion coordinated to a ligand. For use in the present disclosure, the solid acid catalyst may comprise sulphuric acid introduced into an amorphous carbon support formed by incomplete carbonization of biomass. Amorphous carbon can be obtained by incomplete carbonization of biomass. In some embodiments of the invention, the biomass may be a lignocellulosic biomass, examples of which include, but are not limited to, wood and straw. In particular, the lignocellulosic biomass may comprise lignin in an amount of 10 - 40 wt.%. The incomplete carbonization can be carried out chemically (using dehydrating agents) or thermally. The heat treatment for incomplete carbonization may be performed at 400 - 600 °C. Subsequently, sulphur trioxide (SO3) is added to the amorphous carbon to introduce sulphonic acid into the amorphous carbon. In particular, the sulphuric acid contains sulphur trioxide in an amount of 15 - 50 wt.%. The solid acid catalyst may contain sulphonic acid in an amount of 0.4 to 0.8 mmol.g'1of amorphous carbon due to being prepared in the form of amorphous carbon having sulphonic acid introduced thereto. In still another aspect of the invention, step 3 is performed in absence of O2. Possible atmospheres are for example N2 or steam (in case of pyrolysis), or a H2 containing atmosphere (in case of hydrocracking).

[0084] In this text, the term "Brpnsted acid" means, for example Brpnsted - Lowry as defined, donate a proton (H+) in the environment of an acid-base reaction. The term "Lewis acid" refers to a substance that accepts an electron pair in an acid-base reaction as defined by Lewis.

[0085] EXAMPLES

[0086] Materials and methods: hydrothermal pre-treatment

[0087] For the experimental procedure, 4 grams of waste LDPE pellets were weighed and transferred to the lOOmL Parr reactor. Secondly, 40 mL of solvent (i.e., Milli-Q or Milli-Q / n-butanol) was added to the reactor and the stirring speed was set to 700 - 750 RPM. To eliminate the presence of O2 in the reactor system, the reactor was flushed three times with N2. Hereafter, the reactor was brought up to 30 bar of N2 at room temperature. An exception was made for experiments at 300 °C, where the starting pressures amounted to 45 bar. After the pressurizing step, the reactor was heated to the pre-programmed temperature (i.e., 25 up to 300 °C). Time was started upon reaching the set point temperature value. After the reaction was finished, the reactor is cooled down while maintaining continuous stirring at 750 rpm. Stirring was stopped when the inner reactor temperature reached 100 °C after which it was depressurized and the stirring was set to zero. The pre-treated plastics were collected and put into an oven at 60 °C to dry overnight. Sample preparation for activity testing on TGA was done using a RETSCH cryogenic grinder. Here, a 50 mL stainless steel grinding jar was filled up to 50% with plastic pellets and a 20 mm diameter stainless steel grinding ball. A pre-cooling step (auto time, ±10 minutes) at 5 Hz was installed to bring the grinding jar at the desired temperature, using liquid N2 as coolant (LN, -196°C). Upon sufficient cooling of the grinding jar, a cryo-grinding step at 30 Hz was maintained for 10 minutes to powder the material. After this process, the plastic was collected and left to dry overnight at 60 °C. TGA experiments

[0088] For catalytic activity experiments, a 3 / 1 plastic / catalyst mixture was prepared (i.e. 15 mg of polyolefin plastic together with 5 mg of catalyst powder) in a 1, 5 mL Eppendorf. Hereafter, the powders were thoroughly mixed using a spatula maximizing the homogeneity of the mixture. This mixture was then transferred to 150pL alumina crucibles. TGA experiments were carried out on a Mettler Toledo TGA / DSC 3+ with a large furnace.

[0089] Lab scale performance tests

[0090] For the semi-batch experiments, 10 grams of waste LDPE and 1 gram of catalyst (10 wt.%) is added to a 100 mL Parr reactor. This mixture was then thoroughly mixed using a spatula. To eliminate the presence of O2 in the reactor, it was flushed three times up to 20 bar of N2 gas. After flushing the reactor, a pre-defined temperature program was followed.

[0091] Quantification of the different gases was made possible by converting the added volume of N2 via a mass flow controller (MFC) into molar fractions within the gas sampling bags (i.e., using the ideal gas law). Molar fraction calibration curves of the pyrolysis products were used to calculate its molar fraction. This was in turn translated into mass fraction within the gassampling bag. At specific time intervals, liquids samples were taken. The glass vials were weighed before and after liquid sampling to calculate the liquid product yield as function of time. Liquid products were further analysed using GC-MS-FID. Solid product yields were calculated using the difference of the weight of the reactor, stirring rod and dip tube before and after the reaction. To calculate the total solid product yield, the difference in mass needs to be corrected for the weight of catalyst added at the start of the reaction.

[0092] Particular and preferred aspects of the invention are set out in the accompanying independent and dependent claims. Features from the dependent claims may be combined with features of the independent claims and with features of other dependent claims as appropriate and not merely as explicitly set out in the claims. Thus, the claims following the detailed description are hereby expressly incorporated into this detailed description, with each claim standing on its own as a separate embodiment of this invention.

[0093] EXAMPLE 1 : Virgin LDPE feedstock catalyst screening

[0094] Figure 5 represents a two-dimensional scatterplot in which the catalysts are presented based on their activity (represented by AT; the temperature difference between the catalytic and thermal pyrolysis of the feedstock) and stability (represented by the coke content as wt.% of the feed). This data has been collected through a small-scale screening approach using Thermogravimetric Analysis (TGA), where virgin LDPE feedstock was mixed with the heterogeneous catalyst in a 3 to 1 ratio, to reach a total sample mass of 20 mg. The sample was subjected to a heating profile composed of a pyrolysis segment under N2 from RT - 600 °C (heating rate 10°C / min) and a coke segment under O2 from 150 - 900 °C (heating rate 10°C / min). Both segments show weight loss events that are used to attribute quantitative parameters about the catalyst activity and stability. Zeolites with MFI topology include materials known as Zeolite Socony Mobil 5 or ZSM-5, which can be used in various Si / AI ratios ranging from 10 - 00. For low Si / AI in a range between 10 - 40, ZSM-5 zeolites are characterized by high activity in conversion of LDPE with major selectivity to gaseous products, with excellent stability. Similarly, ZSM-11 zeolite with MEL topology is characterized by high activity and stability. When other zeolite materials 10 membered-ring micropores are considered, for instance ferrierite and ZSM-35 (FER), ZSM-22 (TON), ZSM-23 (MTT), SAPO-11 (AEL), MCM-22 (MWW), moderate to low activity is observed simultaneously with high stability, independent of the Si / AI. Moreover, ZSM-5 zeolites with high Si / AI also show moderate to low activity, while high stability is preserved.

[0095] Among the class of 12 membered-ring zeolite topologies, Y-zeolite and Ultra- Stable-Y zeolite (USY) (FAU), Beta (*BEA) and mordenite (MOR) are included. The 12 membered ring micropores makes the catalyst more prone to coke formation, which can lead to catalyst deactivation. In general, these catalysts show high catalyst activity. Amorphous silica-alumina materials of interest are for instance provided by SASOL as the SIRAL series (ASA(XX) series), comprising SIRAL1, SIRAL5, SIRAL10, SIRAL20, SIRAL20HPV, SIRAL28, SIRAL30, SIRAL40, SIRAL40HPV, SIRAL70HPV. Additionally, AI-MCM-41 can form an interesting choice. The aforementioned catalysts are generally stable against coke formation, while the activity depends on the composition and relative distribution of SiO2 and AI2O3.

[0096] Example 2: Virgin PP feedstock catalyst screening

[0097] Figure 6 represents a two-dimensional scatterplot in which the catalysts are presented based on their activity (represented by AT; the temperature difference between the catalytic and thermal pyrolysis of the feedstock) and stability (represented by the coke content as wt.% of the feed). This data has been collected through a small-scale screening approach using Thermogravimetric Analysis (TGA), where LDPE feedstock was mixed with the heterogeneous catalyst in a 3 to 1 ratio, to reach a total sample mass of 20 mg. The sample was subjected to a heating profile composed of a pyrolysis segment under N2 from RT - 600 °C (heating rate 10°C / min) and a coke segment under O2 from 150 - 900 °C (heating rate 10°C / min). Both segments show weight loss events that are used to attribute quantitative parameters about the catalyst activity and stability.

[0098] Example 3: Virgin PS feedstock catalyst screening

[0099] Figure 7 represents a two-dimensional scatterplot in which the catalysts are presented based on their activity (represented by AT; the temperature difference between the catalytic and thermal pyrolysis of the feedstock) and stability (represented by the coke content as wt.% of the feed). This data has been collected through a small-scale screening approach using Thermogravimetric Analysis (TGA), where LDPE feedstock was mixed with the heterogeneous catalyst in a 3 to 1 ratio, to reach a total sample mass of 20 mg. The sample was subjected to a heating profile composed of a pyrolysis segment under N2 from RT - 600 °C (heating rate 10°C / min) and a coke segment under O2 from 150 - 900 °C (heating rate 10°C / min). Both segments show weight loss events that are used to attribute quantitative parameters about the catalyst activity and stability.

[0100] The scatterplot highlights acidic Ferrierite (FER) and ZSM-35 catalysts as topperformers, scoring excellent on both the activity and stability criteria. These materials follow the FER. topology, a zeolite class with 10 membered-ring (MR) pore channels oscillating along 1 direction. Other 10 MR zeolite materials maintain a high stability but show mostly reduced activity. Low- acidic catalysts have a positive AT value, indicating an inhibitive effect compared to thermal pyrolysis. The tested 12 MR zeolites, including Y, USY, BEA and MOR, are generally more prone to catalyst deactivation compared to 10 MR zeolites. A high acidity is required in order to achieve gain in activity over thermal pyrolysis. The activity of mesoporous ASA catalysts again is largely influenced by their acidity, reaching the highest activity using the most acidic ASA 70HPV catalysts.

[0101] Example 4: Virgin and polluted LDPE catalytic pyrolysis for example catalysts Figures 4A and 4B show the effects of the use of polluted LDPE feedstock compared to the use of virgin LDPE feedstocks for example catalysts SIRAL

[0040] HPV (SASOL) and HZSM-5(25) (CBV5524G, Zeolyst).

[0102] SIRAL

[0040] HPV is a material from the amorphous silica-alumina type which predominantly produces liquid products. HZSM-5(25) (CBV5524G, Zeolyst) is a crystalline aluminosilicate zeolite material with a MFI topology and a silicon to aluminium ratio (Si / AI) of 25 which predominantly produces gaseous products.

[0103] From the small-scale TGA screening, the large deactivation for both example catalysts can be readily observed as the delayed mass loss for the case of the polluted LDPE feedstock (i.e., mass loss at higher temperatures). Deactivation for the amorphous silica-alumina catalyst is more severe than the crystalline aluminosilicate zeolite, which can be seen from the higher AT- value.

[0104] Example 5: Effect of ore-treatment with 100voL% water extractant phase (LDPE) Figures 8B and 9B show the temperature effects of the pre-treatment step of polluted LDPE feedstocks in the 100vol. % H2O liquid phase compared to the use of virgin LDPE feedstock for example catalysts SIRAL

[0040] HPV (SASOL) and HZSM-5(25) (CBV5524G, Zeolyst). SIRAL

[0040] HPV is a material from the amorphous silica-alumina type which predominantly produces liquid products. HZSM-5(25) (CBV5524G) is a crystalline aluminosilicate zeolite material with a MFI topology and a silicon to aluminium ratio (Si / AI) of 25 which predominantly produces gaseous products.

[0105] For both example catalysts, the pre-treatment of the polluted LDPE feedstock in 100vol. % H2O liquid phase does not yield large benefits in the region between 25 - 150 °C. At temperatures from 200 °C, decreases in catalyst deactivation are visualized as lower values of AT.

[0106] Example 6: Effect of pre-treatment with 50 / 50vol.% water / n-butanol extractant phase (LDPE)

[0107] Figures 10B and 11B show the temperature effects of the pre-treatment step of polluted LDPE feedstocks in the 50 / 50vol.% FhO / n-butanol liquid phase compared to the use of virgin LDPE feedstock for example catalysts SIRAL

[0040] HPV (SASOL) and HZSM-5(25) (CBV5524G, Zeolyst).

[0108] SIRAL

[0040] HPV is a material from the amorphous silica-alumina type which predominantly produces liquid products. HZSM-5(25) (CBV5524G) is a crystalline aluminosilicate zeolite material with a MFI topology and a silicon to aluminium ratio (Si / AI) of 25 which predominantly produces gaseous products.

[0109] For both example catalysts, the pre treatment of the polluted LDPE feedstock shows lower AT values for the entire tested temperature range (i.e., higher pre-treatment temperatures).

[0110] 7: Effect of pre-treatment with 100vol. % water extractant

[0111] Figures 12B and 13B show the temperature effects of the pre-treatment step of polluted PS feedstocks in the 100vol. % H2O liquid phase compared to the use of virgin PS feedstock for example catalysts SIRAL

[0070] HPV (SASOL) and FER(9) (HSZ720NHA, TASOH).

[0112] For example catalyst SIRAL

[0070] HPV, activity improvements are observed for the entire temperature range of 25-300 °C. Higher activity is observed for higher pre-treatment temperatures. For example catalyst FER(9), little to no activity improvements are observed for temperatures 25 and 100 °C. at 250- 300 °C, higher activity is translated as lower value for AT.

[0113] Example 8: levels of oxygen gas during pyrolysis - calculations for the amount of oxygen present.A formula to calculate the remaining amount of oxygen as volume percent after inertization in the catalytic pyrolysis experiments was as follows

[0114] In this, the average amount of oxygen in the supplied N2 flush is 2 ppm. After the first inertization step, the total amount of oxygen in the system was equal to :

[0115] (1 * 0 21 + 20 * (2 * 10“6))

[0116] Similar oxygen gas dilution is carried out in a second and third flush. Numerical values are given as:

[0117] Second flush:

[0118] > (10001.9 * 10“6* 0.21 + 20 * (2 * 10“6)) > _6476.3 * 10

[0119] Third flush:

[0120] > (476.3 * 10“6 * 0.21 + 20 * (2 * 10“6)) > _622.7 * 10

[0121] From these calculations, the start of the catalytic reactions include around 23 ppm of residual oxygen gas in the ideal case.

[0122] :-consumer waste

[0123] Figure 16 demonstrates improved hydrocracking on a pretreated PCW PE (15 g) with a Pt / CBV901 bifunctional catalyst (1.5 g). Hydrocracking was performed in a 100 mL batch reactor under a dynamic temperature profile (Figure 14A), under a 10 bar hydrogen pressure. Hydrocracking of virgin PE gives a high C5-C12 yield (52%), which drastically decreased with PCW PE (24 wt%). Applying the pretreatment to the PCW PE leads to improved hydrocracking, given the C5-C12 yield that increased to 32 wt%. This indicates that the pretreatment was successful to partially overcome catalyst deactivation due to the removal of contaminants. This is also represented by the Bromine number (determined viaXH-NMR), which is a measure for the degree of unsaturation (olefin content) in the liquid fraction, calculated as the amount of grams Br2 absorbed per 100 gram sample. Hydrocracking of virgin PE yields a predominantly saturated pyrolysis oil with a Bromine number of 21. Hydrocracking of PCW PE yields a substantially higher Bromine number of 97 (olefin rich), demonstrating deactivation of the (de)hydrogenation functionality in the bifunctional catalyst. Application of the pretreatment decreased the Bromine number again to 41, indicating that catalyst deactivation has been partially overcome as a result of contaminant removal.

Claims

33METHOD OF MANUFACTURECLAIMS1. A method of producing hydrocarbon products from a feedstock comprising polyolefin polymers and non-polyolefin constituents, whereby the method comprises the steps:1) a pretreatment of stirring or agitating the feedstock in a polar solvent under increased pressure conditions at a temperature in the range of 175-300°C, thereby transforming the mix into at least two immiscible liquid phases comprising:1) a first liquid phase comprising the polyolefin polymers in a nondissolved molten state, and ii) a second liquid phase comprising the polar solvent having the non- polyolefin constituents dispersed or dissolved therein,2) separating the first liquid phase from the second liquid phase; and3) heating the separated first liquid phase comprising the polyolefin polymers in the presence of a catalyst in an atmosphere having an oxygen content below 5 percent based on the total interior volume of the reactor, and at a temperature in the range of 200-700°C.

2. The method according to claim 1, whereby the polar solvent is water, an alcohol or a mixture thereof.

3. The method according to any one of claims 1 to 2, whereby the volume ratio of polar solvent on the one hand to the polymer on the other hand is in the range of 20 to 5 mL solvent / g polymer, and preferably 12 to 8 mL solvent / gram polymer.

4. The method according to any one of claims 1 to 3, whereby in step 2 the melted state polyolefin polymer is separated by countercurrent separation, preferably by countercurrent extruder separation.

345. The method according to any one of claims 1 to 4, whereby the catalyst is an acid catalyst.

6. The method according to claim 5, whereby the acid catalyst is a crystalline or non-crystalline aluminosilicate material, preferably an acid zeolite.

7. The method according to claim 5, whereby the acid catalyst is a solid bifunctional catalyst whereby an acidic component is configured to promote acid-catalysed reactions including isomerization and cracking, and a metallic component is configured to promote metal-catalysed reactions including hydrogenation and dehydrogenation.

8. The method according to any one of claims 1 to 7, whereby absence of O2 is oxygen below 5 part per million (ppm) and preferably below 1 part per million (ppm).

9. The method according to any one of claims 1 to 8, whereby pretreatment or starting pressure conditions in step 1) are at a pressure between 0,2 to 2 MPa.

10. The method according to any of claims 1 to 9, whereby the feedstock further comprises non-polyolefin (in)organic constituents.

11. The method according to any one of claims 1 to 10, whereby the feedstock is a mixture of a reclaimed plastic or post-consumer waste.

12. The method according to any one of the claims 1 to 10, whereby the polyolefin polymer of the feedstock comprises one or more of PE (Polyethylene), PP (Polypropylene) and PS (Polystyrene).

13. The method according to any one of the claims 1 to 11, whereby the non-polyolefin polymer of the feedstock comprises one or more of a compound selected of the group consisting of PET (Polyethylene Terephthalate), PVC (Polyvinyl Chloride), PC (Polycarbonate), PA (Polyamide, commonly known as Nylon), PMMA (Polymethyl Methacrylate), ABS (Acrylonitrile Butadiene Styrene), PBT (Polybutylene Terephthalate), PI_A (Polylactic Acid) PU (Polyurethane), thermoplastic polyurethane elastomers, polyamides polymethacrylates, polyvinylidene fluoride, polycarbonates, polyesters, polystyrene, polyacrylonitrile, and acrylonitrile-butadiene- styrene copolymer.

14. The method according to any one of the claims 1 to 13, whereby nonpolymer (in)organic constituents in the feedstock comprise (in)organic salts and / or (in)organic additives.

15. Use of hydrocarbon products obtained by the method according to any one of claims 1 to 13, for the manufacture of base chemicals for the chemical industry of the group consisting of naphtha, light olefins (ethylene, propylene, butene), fuels, plastics, and synthetic fibres, lubricants, carbon (e.g., carbon nanotubes), and hydrogen.

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