PROCESS FOR CONVERTING PLASTIC WASTE WITH NO PRODUCTION OF SOLIDS

Abstract

The invention relates to a process for converting plastic waste, comprising the following steps: a) a plastic waste melting step, b) a thermal cracking step of the molten plastic waste produced in step a) in a thermal cracking reactor, this step being carried out at a temperature of 360 to 465 °C, a pressure of 1 to 10 bar gauge and a residence time of 20 minutes to 1 hour, and during which volatile products and a liquid residue are formed under the conditions of implementation of step b), c) a rapid cooling step of the volatile products, d) a withdrawal step of the liquid residue. Figure: NONE.

Description

Title of the invention: METHOD FOR CONVERTING PLASTIC WASTE WITHOUT PRODUCTION OF SOLIDS Technical field

[0001] The present invention relates to the field of plastics recycling. In particular, the present invention relates to a thermal conversion process for plastic waste without the production of solids. State of the art

[0002] Plastics are commonly used because of their low price and versatility. However, they are often single-use and represent a significant portion of household waste. There is therefore a strong need, also encouraged by regulations, to limit plastic waste in landfills and to recycle it.

[0003] It is known to valorize plastic waste by using it as an initial feedstock in chemical processes (gasification, pyrolysis, depolymerization, dissolution) or in mechanical processes (shredding). In the initial feedstock, plastic waste can also be combined with waste from biomass.

[0004] High-temperature pyrolysis processes make it possible to transform plastic waste into several products in varying proportions depending on the nature of the waste used and the pyrolysis conditions: - an oil, consisting of the condensable volatile products formed during pyrolysis, - a gaseous mixture, - and coke (or "char").

[0005] The oil from the pyrolysis of plastic can be used in other processes, possibly after being separated into several fractions. However, the coke, which can represent 10 to 20% by mass of the pyrolysis products, is difficult to valorize. Its chemical composition and mechanical properties make it difficult to use in metallurgy and cement production. Thus, current solutions for coke valorization are limited to thermal energy recovery or landfilling.

[0006] Furthermore, the formation of this solid coke requires specific treatment to discharge it from the pyrolyzer at the end of the process, which complicates process continuity. It may indeed be necessary to provide a solids extraction system specifically designed for a pressurized reactor, allowing the solids to be separated from the liquid phase and the solids-free product to be returned to the pyrolyzer, as described in document ES2759939B2. This document describes, in particular, a a relatively complex system which may consist of a heat exchanger, a buffer tank, a safety filter, an automatic filter with a mesh size of 1 to 40 microns, a pumping system to the reactor, a second heat exchanger and an auxiliary cleaning and maintenance system.

[0007] Finally, the thermal recovery of coke at the end of pyrolysis strongly impacts the carbon balance of the process.

[0008] There is a need to limit the production of coke during a plastic pyrolysis process.

[0009] There is also a need to increase the quantity of valuable products obtained by pyrolysis of plastic.

[0010] There is also a need to facilitate the implementation of a plastic pyrolysis process, and in particular to allow continuous operation of the process. Summary of the invention

[0011] A first object of the invention relates to a waste conversion process plastics including the following steps:

[0012] a) a step of melting plastic waste,

[0013] b) a thermal cracking step of the melted plastic waste produced in the step a) in a thermal cracking reactor, this step being carried out at a temperature of 360 to 465 °C, a pressure of 1 to 10 bar gauge and a residence time of 20 minutes to 1 hour, and during which volatile products and a liquid residue are formed, in particular only, under the conditions of implementation of step b),

[0014] c) a rapid cooling step for volatile products,

[0015] d) a step of drawing off the liquid residue.

[0016] The implementation conditions of step b) according to the invention allow for the thermal cracking of plastic waste without coking of the products formed. Thus, during step b), no coke is formed, or a very small amount of coke is formed and ends up in the residue. The residue may then contain at most 5% coke by mass, most often at most 3% by mass, or even at most 1% by mass. Thus, during step b), no solid products are formed separately from the volatile products and the residue; only two phases are formed: a vaporized phase and a liquid phase. This allows for the continuous recovery of the volatile products and the liquid residue under the conditions of step b).

[0017] Advantageously, prior to step a), the process may include a plastic waste conditioning step comprising one or more optical separation, grinding, chopping, screening, magnetic and / or eddy separation, centrifugation, density separation and / or agglomeration operations.

[0018] Advantageously, the plastic waste treated in the process according to the invention may comprise one or more of the following characteristics:

[0019] - a mineral content measured according to ASTM D6375 of 0 to 7% preferably 0 to 5% by mass, more preferably 1 to 2% by mass, the remainder being made up of polymers,

[0020] - at least 80% by mass, preferably at least 85% by mass, more than preferably at least 90% by mass, even more preferably at least 95% by mass of polyolefins,

[0021] - at most 20% by mass, preferably at most 10% by mass, more than preference of at most 5% by mass, of aromatic polymers.

[0022] The residue formed in step b) may have one or more of the following characteristics:

[0023] - a content of xylene insolubles measured according to ASTM D5630 of 0 at 7% by mass, preferably from 0 to 3% by mass, more preferably from 1 to 2% by mass,

[0024] - the residue is liquid at temperatures ranging from 90 to 180 °C, preferably from 90 to 140 °C,

[0025] - a final melting temperature measured by thermal analysis (DSC), during a second heating ramp between -80 °C and 180 °C at 10 °C / min, ranging from 90 to 180 °C, preferably from 90 to 140 °C,

[0026] - 40% to 70% by mass of the residue, preferably 40% to 60% by mass of the residue, exhibits a boiling point of 650 °C or higher, preferably 660 °C or higher, but not more than 760 °C, according to ASTM D7169:20,

[0027] - an initial boiling point of at least 250 °C measured according to ASTM standard D7169:20,

[0028] - a boiling point at 20% by mass, measured according to ASTM standard D7169:20, from 530 to 580 °C,

[0029] - a total metal content, measured according to standard IP 501, of no more than 7% in mass, preferably not more than 1% by mass, more preferably not more than 8000 ppm by mass, and preferably not more than 5000 ppm by mass.

[0030] Step b) may include one or more of the following features:

[0031] - step b) is carried out under an inert atmosphere,

[0032] - step b) is carried out in the absence of a catalyst, in particular in the absence of a catalyst inseparable from the residue,

[0033] - the temperature, pressure and residence time conditions of step b) are controlled to obtain a residue with a xylene insolubles content measured according to ASTM D5630 of 0 to 7% by mass, preferably 0 to 3% by mass, more preferably 1 to 2% by mass.

[0034] Advantageously, steps a) to d) of the process can be implemented continuously.

[0035] The method according to the invention may further comprise one or more of the following steps:

[0036] - a step of incorporating at least a portion of the residue recovered in step d) to a bitumen base or a waterproofing membrane,

[0037] - a viscoreduction step of at least part of the residue recovered in step d), alone or mixed with a fossil hydrocarbon feedstock,

[0038] - a coking step of at least a portion of the residue recovered in step d), alone or mixed with a fossil hydrocarbon feedstock.

[0039] The invention also relates to a thermal conversion residue of plastic waste, which can be obtained by the process according to the invention, said residue being liquid at temperatures ranging from 90 to 180 °C, preferably from 90 to 140 °C, and of which 40% to 70% by mass, preferably 40 to 60% by mass, has a boiling point of 650 °C or more, preferably 660 °C or more, in particular not more than 760 °C according to ASTM D7169:20.

[0040] In particular, said residue may exhibit one or more of the following characteristics:

[0041] - a content of xylene insolubles measured according to ASTM D5630 of 0 at 7% by mass, preferably from 0 to 3% by mass, more preferably from 1 to 2% by mass,

[0042] - a final melting temperature measured by thermal analysis, during a second heating ramp between -80 °C and 180 °C at 10 °C / min, ranging from 90 to 180 °C, preferably from 90 to 140 °C,

[0043] - an initial boiling point of at least 250 °C measured according to ASTM standard D7169:20,

[0044] - a boiling point at 20% by mass, measured according to ASTM standard D7169:20, from 530 to 580 °C,

[0045] - a total metal content, measured according to standard IP 501, of no more than 7% in mass, preferably not more than 1% by mass, more preferably not more than 8000 ppm by mass, and preferably not more than 5000 ppm by mass.

[0046] The invention further relates to the use of the thermal conversion residue according to the invention in a bituminous composition, in particular in mixture with a bitumen base and / or a bitumen / polymer composition; or in a waterproofing membrane.

[0047] The invention further relates to the use of the thermal conversion residue according to the invention as a feed in a coking or viscoeduction unit, alone or in a mixture with a fossil hydrocarbon feed. Detailed description of the invention

[0048] Unless explicitly stated otherwise, the standards mentioned in the rest of the description correspond to the standard in force on July 12, 2024.

[0049] The term "boiling point" used here refers to the boiling point generally used in the oil and gas industry. Boiling points are measured at atmospheric pressure. The initial boiling point is defined as the temperature at which the first vapor bubble forms. The final boiling point is the highest temperature achievable during standard distillation. At this temperature, no more vapor can be drawn into the condensing units. The determination of the initial and final boiling points is known per se. Depending on the boiling range of the mixture, they can be determined using various standardized methods, such as ASTM D2887:2019, which relates to the distribution of the boiling range of petroleum fractions by gas chromatography.

[0050] For compositions containing heavier hydrocarbons, ASTM D7169:2020 or D2892-20:2020 may also be used. The boiling ranges of distillates may also be advantageously measured using ASTM D7500:2019.

[0051] The invention relates firstly to a method for converting plastic waste, comprising the following steps:

[0052] a) a step of melting plastic waste,

[0053] b) a step of thermal cracking the molten plastic waste produced in the step a) in a thermal cracking reactor, this step being carried out at a temperature of 360 to 465 °C, a pressure of 1 to 10 gauge bar (relative bar) and a residence time of 20 minutes to 1 hour, and during which volatile products and a liquid residue are formed under the conditions of implementation of step b),

[0054] c) a step of rapid cooling of the volatile products,

[0055] d) a step of withdrawal of the liquid residue. Plastic waste

[0056] In principle, all types of plastic waste can be converted by the process according to the invention. However, a preliminary step of sorting non-organic waste may be desirable.

[0057] Plastic waste is a complex and heterogeneous material due to several factors. First, plastic as a material refers to many different polymers with varying chemical properties that can be separated from one another before recycling or recycled as a complex mixture. The main polymers present in the Plastics derived from municipal solid waste include polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), and polystyrene (PS). Other polymers primarily include polyurethanes, polyamides (PA), polycarbonates, polyethers, and polyesters other than PET. Furthermore, numerous additives, different from the base polymers, are introduced during the plastic production phase to adjust or improve the plastic's properties or to meet specific requirements. These include functional additives such as stabilizers, antistatic agents, flame retardants, plasticizers, lubricants, sliding agents, curing agents, foaming agents, biocides, and antioxidants.), colorants and pigments, fillers (e.g., glass fibers, talc, carbon fibers, carbon nanotubes), commonly used in plastic packaging, as well as additives such as flame retardants, frequently used in plastics for electronics. In addition, several metallic compounds are intentionally added during plastic production (often in the form of oxides, carbonates, acids, etc.). Additives containing heteroatoms other than metals are also used in plastics manufacturing, for example, halogens such as bromine in flame retardants, plasticizers, stabilizers, etc.

[0058] Silicone polymers, which are organic materials containing silicon, are often used in plastic formulations. Thanks to their surface characteristics, the applications of silicones range from silicone rubbers, used as sealants for joints, to silicone surfactants for cosmetic products, while they are increasingly used in the plastics sector as process-improving additives (manufacturing auxiliaries), and for polymer modification.

[0059] In addition to these heteroelements, used plastic waste may have been contaminated during its lifetime by residues of liquids with which it has been in contact (beverages, personal care products, etc.) and food, which can also contaminate the plastic. Finally, some plastic waste may be present in the form of partially decomposed waste, such as partially burned plastic.

[0060] Polyolefins, namely polyethylene and polypropylene, typically represent 60 to 70% by mass of the plastics present in municipal solid waste. Polystyrene typically represents 10-20% by mass of this waste.

[0061] Typically, the plastic waste used in the present process includes bags, bottles, films, sheets, fibers, textiles, pipes or other molded or extruded products.

[0062] Preferably, the plastic waste used in the present process has a polyolefin content of at least 80% by mass, for example from 80 to 100% by mass, preferably at least 85% by mass, more preferably at least 90% by mass, even more preferably at least 95% by mass, or even at least 99% by mass. Preferably, the polyolefins are polyethylene and / or polypropylene.

[0063] Polyethylene includes all forms of polyethylene, including high-density polyethylene (HDPE) and low-density polyethylene (LDPE). High-density and low-density polyethylenes are ethylene polymers with the formula (CH2CH2)n. LDPE typically has a molecular mass of 30,000 to 50,000 g / mol and a density of 0.910 to 0.925 g / cm³, while HDPE typically has a molecular mass of 200,000 to 500,000 g / mol and a density of 0.941 to 0.980 g / cm³.

[0064] Polypropylene is a propylene polymer with the formula (CH(CH3)CH2)n. It typically has a density of 0.895 to 0.92 g / cm3 and a melting point of 130 to 170 °C.

[0065] Polypropylene and polyethylene can be copolymerized with other polymers such as vinyl acetate or an acrylate.

[0066] Other plastics are preferably present in plastic waste in quantities of not more than 20% by mass, for example from 0 to 20% by mass, preferably not more than 10% by mass, more preferably not more than 5% by mass, or even in a quantity of not more than 1% by mass. These other plastics include aromatic polymers, for example polystyrene, halogenated polymers, for example polyvinyl chloride and polytetrafluoroethylene, and polyester-based polymers, for example polyethylene terephthalate.

[0067] Preferably, aromatic polymers, in particular polystyrene, are present in quantities of at most 20% by mass, for example from 0 to 20% by mass, preferably at most 10% by mass, more preferably at most 5% by mass or even in an amount of at most 1% by mass.

[0068] Preferably halogenated polymers, and in particular chlorinated polymers, are present in small quantities in plastic waste, preferably in a content of no more than 0.1% by mass, for example from 0 to 0.1% by mass, more preferably in an amount of no more than 0.07% by mass.

[0069] Plastic waste may include contaminants such as metals, pigments, etc. Preferably, these contaminants are present in the waste in quantities of no more than 5% by mass, preferably no more than 1% by mass.

[0070] Preferably, the plastic waste used has a mineral filler content measured according to ASTM D6375 of 0 to 7%, preferably 0 to 5% % by mass, preferably more like 1 to 2% by mass, the rest being made up of polymers.

[0071] Preferably, the plastic waste used in the present process has a size ranging from 1 to 40 mm. Optional preliminary conditioning step

[0072] The conditioning step may include one or more operations of optical separation, grinding, chopping, screening, magnetic and / or eddy separation, centrifugation, density separation and / or agglomeration.

[0073] In this way, undesirable compounds, such as the organic fraction, paper, cardboard, metal, glass, etc. possibly present in plastic waste are at least partially eliminated.

[0074] In particular, the conditioning may include the agglomeration or densification of plastic waste up to a density of 200-450 kg / m3.

[0075] The conditioned waste thus obtained may include one or more of the following characteristics: - a density of 200-450 kg / m3, - a size ranging from 10 to 30 mm, - maximum moisture content of 15% by mass, - a mineral filler content measured according to ASTM D6375 of 0 to 7%, preferably 0 to 5% by mass, preferably more than 1 to 2% by mass, the remainder being composed of polymers, - a polyolefin content, in particular polyethylene and / or polypropylene, of at least 80% by mass, preferably at least 85% by mass, more preferably at least 90% by mass, even more preferably at least 95% by mass, or even at least 99% by mass. - A content of aromatic polymers, in particular polystyrene, of not more than 20% by mass, for example from 0 to 20% by mass, preferably not more than 10% by mass, more preferably not more than 5% by mass or even in a quantity of not more than 1% by mass. - Plastic waste can be in the form of granules, flakes, threads, fibers, films or shreds. Step a) of merging

[0076] During this step the previously defined plastic waste, possibly conditioned, is melted, and optionally homogenized.

[0077] For this purpose, the plastic waste is heated to a temperature above the melting point of the various polymers present in the waste, typically from 200 to 400 °C, preferably from 250 to 350 °C, more preferably from 265 to 325 °C, which allows obtaining a mixture of molten polymers.

[0078] This step can be carried out at a pressure greater than or equal to the implementation pressure of step b). Step a) can thus be pressurized with an inert gas, for example nitrogen or argon, preferably nitrogen, until the pressure reaches a pressure value between 1 and 5 gauge bar above the operating pressure of the thermal cracking reactor of step b).

[0079] The melting, and optionally the homogenization, of the plastic waste can advantageously be carried out continuously, for example in an extruder. The extruder can advantageously comprise a screw extruder heated by any suitable means (electric heating, microwave heating, or other).

[0080] For example, a heated extruder or piston can be used to cyclically introduce plastic waste in alternating sequences into two previously inert (preferably nitrogen) transfer chambers equipped with agitators. Alternatively, a screw extruder or a flap-gate silo capable of directly receiving pellets can be used.

[0081] Step a) may include several sub-steps:

[0082] - a step of filling a first transfer chamber;

[0083] - when the first transfer chamber is full, stop filling the first transfer chamber and begin filling a second transfer chamber;

[0084] - simultaneously with the filling of the second transfer chamber, heat the raw material in the first transfer chamber and pressurize it with nitrogen;

[0085] - after reaching the appropriate temperature and pressure, introduce the material first melted in the cracking reactor of step b);

[0086] - cyclically repeat the previous steps, alternating the filling, the heating and pressurization of the first and second transfer chambers.

[0087] At the end of step a), the melted plastic waste is transferred to the thermal cracking reactor.

[0088] This transfer can be carried out from one of the transfer chambers, during the filling of the other transfer chamber, in particular by means of a pressure gradient.

[0089] The use of two transfer chambers also helps to homogenize and stabilize the operation, since the presence of two chambers dampens any potential failures or changes in the material conditions from the extruder. Furthermore, this system allows the use of a pressure gradient to transfer the molten polymers, thus eliminating the need for mechanical components such as augers, etc.

[0090] According to one embodiment of the invention, the chambers consist of cylindrical steel tanks with a klopper bottom and the heating system of these tanks can be achieved by means of hot gases from the burner (used for the energy use of the gas generated during the thermal cracking process) or by means of a thermal oil jacket. Step b) of thermal cracking

[0091] During this step, the melted plastic waste exiting step a) undergoes thermal cracking in a thermal cracking reactor.

[0092] This reaction is carried out at a temperature of 360 to 465 °C, a pressure of 1 to 10 bar gauge and a residence time of 20 minutes to 1 hour, under conditions allowing the formation of volatile products and a liquid residue, without however leading to coking of the products and the formation of non-liquefiable char.

[0093] The volatile products contain condensable hydrocarbon compounds, which form a pyrolysis oil, and a non-condensable gaseous fraction.

[0094] The residue obtained is liquid under the implementation conditions of step b).

[0095] In order to ensure that step b) takes place without coking, one could, for example control the content of the residue insoluble in xylene measured according to ASTM D5630.

[0096] Preferably, the temperature, pressure and residence time will be controlled so that the content of the residue in xylene insolubles is 0 to 7% by mass, preferably 0 to 3% by mass, more preferably 1 to 2% by mass.

[0097] Step b) of cracking is preferably exclusively thermal, carried out in the absence of any catalyst, which avoids the risk associated with its deactivation (by coke deposition and poisoning due to the presence of elements such as chlorine, sulfur, nitrogen, and metals contained in some of the additives used to improve the properties of polymers), its consumption, its recovery, and its management as waste. This also reduces the costs associated with the process of the present invention. If a catalyst is present, a catalyst separable from the residue may be used.

[0098] Step b) is typically carried out in the absence of oxygen. It can be carried out in the presence of an inert gas (nitrogen or argon) or not. However, the use of an inert carrier gas is not necessary to perform the thermal cracking step. The pressure obtained in the reactor autogenously, with the gases formed during the degradation of the polymer materials, is in fact sufficient to carry the volatile products produced to the next step c) of the process.

[0099] Step b) can be carried out in the presence of calcium oxide to remove hydrochloric acid (HCl) present or formed during the process. The amount of calcium oxide can be from 1 to 5% by mass relative to the mass of plastic waste. treated, preferably 2 to 4% by mass, more preferably 2.5 to 3.5% by mass. Calcium oxide may be added to the plastic waste during step a) or b), preferably during step a).

[0100] Step b) is carried out in a thermal cracking reactor. For example, a continuously stirred tank reactor, a rotary kiln, or any other suitable reactor may be used. This reactor, typically cylindrical in shape, can advantageously be arranged vertically to facilitate the removal of the residue from a lower section and the evacuation of volatile products from an upper section. The reactor can also be arranged horizontally and include a screw conveyor that advances the residue towards the removal point progressively during the thermal cracking reaction. This reactor can be heated by any suitable means, for example, by burners or electric heating, or by the presence of a solid support such as silicon carbide and microwave heating, or by the presence of metallic components and induction heating.

[0101] The molten waste from step b) can be introduced into the cracking reactor by any suitable means, for example through a suitable pipe. Step c) Rapid cooling

[0102] During this step, the volatile products formed during step b) are rapidly cooled.

[0103] Rapid cooling is achieved, for example, by using one or more condensers connected to an outlet of the cracking reactor.

[0104] Any type of condenser can be used, such as indirectly cooled condensers, for example shell and core heat exchangers (using, for example, a mixture of water and monoethylene glycol at 30% by volume as a coolant), or directly cooled or quenching condensers using, for example, pyrolysis liquids generated in the process itself.

[0105] Cooling in step c) yields an outlet stream at a temperature typically below 80 °C, preferably below 50 °C, consisting of pyrolysis liquids and non-condensable gases. The pyrolysis liquids are collected in a tank equipped with a mechanical stirring system, where they are stored in an inert atmosphere and at a temperature above the cloud point to prevent the paraffins from freezing. These pyrolysis liquids, also called pyrolysis oils, can be fractionated into several cuts depending on their subsequent use.

[0106] Non-condensable gases may include dihydrogen and C1-C6 hydrocarbons (mainly rich in C4 compounds). These gases have a high calorific value and can be used as fuel, for example to meet the energy requirements of the process according to the invention, in particular to heat the cracking reactor and / or to provide the thermal energy needed for the fusion step a). Step d) of removing the residue

[0107] Insofar as the residue is liquid under the implementation conditions of step b), the withdrawal can be carried out in the usual way from a lower part of the thermal cracking reactor used.

[0108] Due to the absence of formation of a solid phase under the implementation conditions of step b), it is not necessary to set up a complex system for extracting solids and / or filtration, or to operate the reactor in batches (batch operation).

[0109] On the contrary, the process according to the invention can be implemented continuously in a simple manner.

[0110] Thus, advantageously, the process according to the invention does not include solid extraction steps and / or solid separation steps. Products of the thermal conversion process

[0111] The process according to the invention thus produces, in particular only: - volatile products, which, after cooling, are separated into pyrolysis oil and non-condensable gases, as previously described, - the residue, liquid under the implementation conditions of step b).

[0112] As already explained, there is no formation of solids under the implementation conditions of step b) because step b) is carried out under conditions that do not produce coking of the products formed.

[0113] The residue is solid at room temperature and liquefiable at temperatures above approximately 90 °C. Hereafter, this residue is referred to interchangeably as a residue or liquefiable solid residue.

[0114] Under the implementation conditions of step b), the residue obtained may exhibit one or more of the properties described below.

[0115] The residue may have a xylene insoluble content measured according to ASTM D5630 of 0 to 7% by mass, preferably 0 to 3% by mass, more preferably 1 to 2% by mass.

[0116] These insolubles may include coke and / or heteroatoms such as metals and / or other elements such as phosphorus, chlorine and / or fluorine.

[0117] The metal content of the residue, typically measured by ICP-OES plasma emission spectrometry according to ASTM D5185 or IP 501, can vary depending on the plastic waste being processed

[0118] The residue according to the invention may have a total metal content, measured by ICP-OES according to standard IP 501, of at most 7% by mass, preferably at most 1 % by mass, preferably not more than 8000 ppm by mass, and preferably not more than 5000 ppm by mass. One or more of the following metals may be present: aluminum Al, barium Ba, calcium Ca, iron Fe, potassium K, magnesium Mg, titanium Ti, sodium Na, zinc Zn. In particular, the residue may contain significant amounts of one or more of the following metals: Al, Ba, Fe, Mg, Ti, and possibly Ca.

[0119] The residue of the invention may have a calcium (Ca) content greater than or equal to 1500 ppm, typically ranging from 1500 ppm to 80000 ppm. This content may be higher, for example typically from less than 30000 ppm up to 80000 ppm.

[0120] The residue of the invention may have an aluminum Al content greater than or equal to 1500 ppm, typically ranging from 1500 ppm to 6000 ppm.

[0121] The residue of the invention may have an iron content Fe greater than or equal to 1000 ppm, typically ranging from 1000 ppm to 4000 ppm.

[0122] The residue of the invention may have a barium Ba content greater than or equal to 150 ppm, often greater than or equal to 300 ppm, typically ranging from 150 ppm to 4000 ppm.

[0123] The residue of the invention may have a magnesium Mg content greater than or equal to 1000 ppm, typically ranging from 1000 ppm to 4000 ppm.

[0124] The residue of the invention may have a titanium element content Ti, greater than or equal to 1000 ppm, often greater than or equal to 5000 ppm, typically ranging from 1000 ppm to 18000 ppm.

[0125] According to one embodiment, the residue of the invention has a silicon (Si) content greater than or equal to 5 ppm, more preferably greater than or equal to 10 ppm, typically ranging from 10 to 15,000 ppm. The silicon content is typically determined by X-ray fluorescence (XRF) after homogenization of the material and appropriate calibration.

[0126] The total metal content of the residue can therefore be relatively high, in particular on the order of 4000 ppm or more. However, it is preferred that it be at most 7% by mass or less, as described above.

[0127] The residue of the invention may also have a phosphorus (P) content greater than or equal to 500 ppm, more preferably greater than or equal to 550 ppm, typically ranging from 500 to 1300 ppm. The phosphorus content is typically determined by acid digestion in a closed microwave instrument due to its volatility. The resulting solution is then analyzed by ICP-OES under conventional acidic conditions.

[0128] The residue can be liquid at temperatures ranging from 90 to 180 °C, preferably from 90 to 140 °C.

[0129] The liquid residue can exhibit a final melting temperature measured by thermal analysis (DSC), during a second heating ramp between -80 °C and 180 °C at 10 °C / min, ranging from 90 to 180 °C, preferably from 90 to 140 °C.

[0130] Distillation is known to be carried out by progressively heating a product. In the case of a pure compound, the entire product is distilled at a constant temperature. Conversely, in the case of a mixture, fractions with different boiling points are evaporated progressively. These boiling points increase during the distillation. The boiling points of the residue according to the invention are determined by simulated distillation in accordance with ASTM D7169:20.

[0131] Simulated distillation of a residue according to the invention shows that 30 to 60% by mass of the residue, preferably 40 to 60% by mass of the residue, more preferably 50 to 60% by mass of the residue, does not distill at a boiling point of 650 °C or more, preferably 660 °C or more, typically 650 to 760 °C according to ASTM D7169:20. In other words, only 40 to 70% by mass of the residue, preferably 40 to 60% by mass of the residue, more preferably 40 to 50% by mass of the residue, has a boiling point of 650 °C or more, preferably 660 °C or more, typically at most 760 °C, according to ASTM D7169:20.Put another way, the boiling point of the remaining portion of the residue once 40 to 70% of the mass of the starting residue, preferably 40 to 60% by mass of the starting residue, more preferably 50 to 60% by mass of the starting residue, has evaporated, is 650 °C or more, preferably 660 °C or more, typically not more than 760 °C according to ASTM D7169:20.

[0132] The residue of the invention may have an initial boiling temperature, measured according to ASTM D7169:20, greater than or equal to 250 °C, more preferably from 250 °C to 400 °C, even more preferably from 275 °C to 390 °C.

[0133] By "boiling point at X% of product Y", we mean, in the sense of the invention, the boiling point of the remaining part of product Y once X% by mass of the starting product has been evaporated.

[0134] Preferably, the residue of the invention has a boiling point at 5% by mass, measured according to ASTM D7169:20, greater than or equal to 400 °C and / or less than or equal to 470 °C.

[0135] Preferably, the residue of the invention has a boiling point at 10% by mass, measured according to ASTM D7169:20, greater than or equal to 440 °C and / or less than or equal to 510 °C.

[0136] Preferably, the residue of the invention has a boiling point at 15% by mass, measured according to ASTM D7169:20, greater than or equal to 480 °C and / or less than or equal to 550 °C.

[0137] Preferably, the residue of the invention has a boiling point at 20% by mass, measured according to ASTM D7169:20, greater than or equal to 530 °C and / or less than or equal to 580 °C.

[0138] Preferably, the residue of the invention has a boiling point at 30% by mass, measured according to ASTM D7169:20, greater than or equal to 600 °C and / or less than or equal to 650 °C.

[0139] Preferably, the residue of the invention has a boiling point at 40% by mass, measured according to ASTM D7169:20, greater than or equal to 650 °C and / or less than or equal to 730 °C.

[0140] Preferably, the residue of the invention has a boiling point at 50% by mass, measured according to ASTM D7169:20, greater than or equal to 720 °C and / or less than or equal to 760 °C.

[0141] The residue of the invention typically exhibits a penetrability at 25°C, measured according to EN 1426, of less than or equal to 40 1 / 10 mm, preferably less than or equal to 35 1 / 10 mm. The residue of the invention may exhibit a penetrability at 25°C, measured according to EN 1426, of greater than or equal to 10 1 / 10 mm, preferably greater than or equal to 15 1 / 10 mm. More preferably, the residue of the invention exhibits a penetrability at 25°C, measured according to EN 1426, ranging from 10 to 40 1 / 10 mm, preferably from 15 to 35 1 / 10 mm.

[0142] The residue of the invention may have a ball and ring softening temperature (BRT), measured according to EN 1427, greater than or equal to 85°C, more preferably ranging from 85°C to 120°C, typically ranging from 90°C to 115°C.

[0143] The residue of the invention has a Cleveland flash point, measured according to ASTM D 92, greater than or equal to 200°C, more preferably greater than or equal to 220°C, typically ranging from 220°C to 350°C, for example from 230°C to 340°C. Applications

[0144] The liquid residue recovered during this drawing-off step can then be stored, possibly hot to prevent its solidification, or sent to other units, such as a coking unit, a viscoelastic reduction unit and / or a unit for manufacturing bituminous compositions or waterproofing membranes.

[0145] In particular, the residue may undergo a coking or visbreaking step, alone or mixed with the usual hydrocarbon feedstocks of these steps. This may, in particular, allow the production of carbonaceous products (coke or visbreaking products), comprising a significant proportion of recycled or waste-derived materials.

[0146] Viscoreduction and coking are reactions well known to those skilled in the art.

[0147] Visbreaking is a thermal cracking reaction carried out under moderate conditions to achieve partial cracking of the feed to be treated. It reduces the viscosity and pour point of the treated feed. Typical visbreaking conditions include a temperature of 370 to 500 °C, preferably 420 to 480 °C, for a duration generally of 1 to 60 minutes, preferably 10 to 45 minutes, and a total pressure generally less than 10 MPa, preferably less than 5 MPa, and more preferably less than 2 MPa.

[0148] Coking is a thermal cracking reaction carried out under severe conditions capable of reducing the viscosity and pour point of the processed feed. Typical coking conditions include a temperature of 400 to 650 °C and a pressure of 0 to 10 bar gauge, preferably 0.3 to 3 bar gauge.

[0149] The proportion of residue according to the invention treated by coking or visbreaking can be from 0.1 to 30% by mass relative to the total mass of feed. The remainder of the feed can be a common fossil feed from these processes, such as, for example, a vacuum distillation residue, or any other heavy feed from a refinery process, such as a heavy hydrocracking residue (commonly called "bleed"), deasphalting pitch, or the like.

[0150] The residue according to the invention can also be incorporated into one or more bitumen bases or into a bitumen / polymer composition to prepare a bituminous composition. For example, 0.1 to 30% by mass of the residue can be incorporated into a bitumen or bitumen / polymer composition.

[0151] These bituminous compositions can then exhibit a high eco-material index. The eco-material index is defined by the following equation:

[0152] Eco-material index = 100% - [% of non-bio-based, non-biodegradable, non-recycled or non-waste materials]. It may be at least 5% by mass, relative to the total mass of product formed, preferably at least 10%, preferably at least 15%.

[0153] Such bituminous compositions can be used as a bituminous binder to prepare a bituminous mix, particularly for roads, in a mixture with aggregates and optionally mineral and / or synthetic fillers. This type of mix is ​​used as a material for the construction and maintenance of roadbeds and their surfacing, as well as for carrying out all roadworks. The aggregates are mineral and / or synthetic aggregates, in particular recycled material, with dimensions greater than 2 mm, preferably between 2 mm and 20 mm.

[0154] These bituminous compositions can advantageously be used to prepare a surface dressing, hot mix asphalt, cold mix asphalt, cold-applied asphalt, or emulsion-treated aggregate. With regard to road applications, the invention aims to Asphalt is also used as a material for manufacturing and covering sidewalks. Asphalt is defined as a mixture of bituminous binder with mineral and / or synthetic fillers.

[0155] With regard to the industrial applications of bituminous compositions, one can mention the manufacture of waterproofing membranes, noise-reducing membranes, insulation membranes, surface coatings, carpet tiles, impregnation layers.

[0156] The invention thus relates, more generally, to the use of a thermal conversion residue of plastic as defined above, in a refinery to reduce the carbon footprint of the refinery's products.

[0157] The "carbon footprint" of a product, as defined in this invention, means the amount of carbon (generally expressed in kg of CO2 equivalent per kg of product) required to produce said product. This amount of carbon equivalent takes into account both energy consumption, particularly related to heating, and raw material consumption. The carbon footprint of a product is typically determined according to either ISO 14040 or ISO 14044.

[0158] The invention is advantageous in that the use of the residue of the invention makes it possible to significantly reduce the content of fossil-based materials produced by a refinery, and in particular bituminous compositions, coking products, and visbreaking products. It is further advantageous in that it makes it possible to increase the quantity of products from the thermal conversion of plastics that can be recovered.

[0159] The invention is illustrated by the following examples given by way of non-limiting example. EXAMPLES

[0160] 1. Characterization of residues

[0161] The physicochemical properties of different residues were evaluated according to the methods detailed in Table 1 below:

[0162] [Tables 1] Property Abbreviation Unit Measurement Method Needle penetration at 25°C P25 1 / 10 mm NF EN 1426 Softening temperature ball and ring TBA °C NF EN 1427 Cleveland flash point TA flash °C ASTM D92 Fraass temperature Fraass °C NF EN12593 Boiling point (initial, 5% by mass, 10% by mass, ... final) Teb(X) With X = ini., 5, 10, ...,fin) °C ASTM D7169:20 Metal content ppm (by mass) By calcination of the material, acidification of the ash and analysis by ICP-OES (IP 501). Phosphorus content P PPm (by mass) By acid digestion in a closed microwave instrument and analysis by ICP-OES under classical acid conditions. Silicon content Si PPm (by mass) By X-ray fluorescence (XRF) after homogenization of the material and appropriate calibration. Initial melting temperature TT A -1 melting °C DSC (second heating ramp between -80°C and 180°C at 10°C / min) Final melting temperature TFfusiOn °C DSC (second heating ramp between -80°C and 180°C at 10°C / min) Viscosity at 100°C, 100 s 1 V100 mPa.S NF EN 13302 Viscosity at 140°C, 100 s 1 V140 mPa.S NF EN 13302

[0163] The following residues were characterized. - Thermal conversion residue of RI plastic, - Plastic thermal conversion residue R2, - Plastic thermal conversion residue R3, - Distillation residue of pyrolysis oils Rdl, - Distillation residue of pyrolysis oils Rd2.

[0164] The residues Rdl and Rd2 are not residues within the meaning of the invention: they are distillation residues of two different plastic pyrolysis oils.

[0165] The physical characteristics of the different residues RI, R2 and R3 according to the invention, and Rdl, Rd2 are given in the following table 2:

[0166] [Tables2] Residual Rdl Residual Rd2 Residual RI Residual R2 Residual R3 P25 (in 1 / 10 mm ) 158 40 19 20 29 TB A (in °C) 82.7 84.6 100 Te 9528 276 TA clear (this) 288 456 302 366 322 Teb (5%) 378 487 418 452 430 Teb (10%) 432 499 467 494 476 Teb (15%) 458 507 509 427 560 550 Teb (30%) 503 528 633 627 620 Teb (40%) 527 541 709 691 684 Teb (50%) 549 554 748 740 Teb (60%) 0 Teb% 573 6 (570%) Teb 667 618 Teb (90%) 738 661 Teb (final) >738 743 TIfusion -12 -10 -10 -11 -10 TFfusion 94 105 107 103 107 Tenors in elements9 per Temne Al1 in mass (3 pp) 2832 4161 2139 Tenure in Ba <LQ <LQ 334 538 341 Teneur en Ca 669 1,7 53297 69012 42522 Teneur en Fe 111 296 1746 2323 1431 Teneur en K 53 <LQ 1003 1336 1095 Teneur en Mg 92 1,4 2208 3380 2240 Mn content 4 1.8 <50 62.3 <50 Na content 84 1.2 140 179 132 Ni content 2 25 73.5 <50 <50 Ti content 836 1 10018 13911 9288 Zn content <LQ 2,8 384 556 363 Teneur en P 56 61 800 956 615 Teneur en Si 286 15 8252 12730 6573

[0167] LQ: limit of quantification 1. Use of residue to prepare bituminous compositions#

[0168] Bituminous compositions were prepared from a B1 Bitumen Base having a penetration at 25°C, measured according to standard NF EN 1426, equal to 76 1 / 10 mm, and a ball and ring softening temperature (BRT), measured according to standard NF EN 1427, equal to 46.4°C, commercially available from TotalEnergies under the reference AZALT® 70-100; and the previously characterized RI, R2, R3, Rdl and Rd2 residues.

[0169] The bituminous compositions Cl to C9 were prepared according to the following protocol:

[0170] The bitumen base is preheated to 130°C for 30 min + / - 15 min. The residue is also preheated, independently, to a temperature above the melting temperature of said residue.

[0171] In a 1 kg reactor, the preheated bitumen base is introduced first, followed by the heated residue. The reactor is then placed in a heating reactor with a mixing temperature of 150°C. The mixture is stirred using a glass paddle and mechanically at a speed of 200 rpm for 30 minutes.

[0172] The details of the compositions are given in the following table 3.

[0173] [Tables3] CO Cl C2 C3 C4 C5 C6 C7 C8 C9 Bitumen B1 (in % w / w) 100 90 85 90 90 85 90 85 90 85 85 Residue RI (in % w / w) - 10 15 - - - - - - - Residue R2 (in % w / w) - - - 10 - - - - - - Residue R3 (in % w / w) - - - - 10 15 - - - - Residue Rdl (in % w / w) - - - - - - 10 15 - - Residue Rd2 (in % w / w) - - - - - - - - 10 15

[0174] Compositions CO and C6 to C9 are comparative bituminous compositions in that they do not include any plastic thermal conversion residue according to the invention. Compositions Cl to C5 are according to the invention.

[0175] The physicochemical properties of the CO₂ to CIO₃ bituminous compositions were evaluated according to the protocols detailed above. The results are reported in Tables 4 and 5 below.

[0176] [Tables4] CO Cl C2 C3 C4 C5 P25 (1 / 10 mm) 76 77 82 79 77 76 TBA (°C) 46.4 58.0 63.4 54.2 56.8 61.2 V100 (mPa.s) 3269.0 1986.6 1512.8 2028.5 2117.7 1289.7 V140 (mPa.s) 330.4 236.2 195.6 246.1 249.9 166.0 Fraass -13 ND ND -12 ND ND

[0177] ND: not determined

[0178] [Tables5] CO C6 C7 C8 C9 P25 (1 / 10 mm) 76 139 179 72 63 TBA (°C) 46.4 50.6 54.4 54.2 62.6 V100 (mPa.s) 3269.0 1033.1 649.3 1429.4 977.1 V140 (mPa.s) 330.4 151.7 109.8 181.4 139.1 Fraass -13 ND ND ND ND Compositions C0 to C5

[0179] It is observed that compositions C1 to C5 according to the invention exhibit increased or equivalent penetration at 25°C to that of residue-free composition C0, despite the very low penetration at 25°C of the residue. They exhibit a higher softening temperature compared to residue-free composition C0. Furthermore, they exhibit significantly lower viscosities at 100°C and 140°C compared to those of composition C0.

[0180] It is thus observed that the gain in TB A is not accompanied by a hardening of the bitumen base, so that the grade of bitumen used is not modified. In other words, the addition of the residue according to the invention does not change the grade of the bitumen to which it is added.

[0181] It is also observed that the cold properties of the compositions are not degraded by the introduction of the residue: the Fraass temperature results are analogous. Comparative compositions C6 to C9

[0182] It is observed that compositions C6 and C7 exhibit higher penetrability at 25°C compared to composition CO, while compositions C8 and C9 exhibit lower penetrability at 25°C compared to composition CO. The effects of distillation residues therefore differ depending on the nature of the residue and, for compositions C6, C7, and C9, lead to a change in the grade of the bitumen base to which they are added.

Claims

Demands

1. A process for converting plastic waste, comprising the following steps: a) a plastic waste melting step, b) a thermal cracking step of the molten plastic waste produced in step a) in a thermal cracking reactor, this step being carried out at a temperature of 360 to 465 °C, a pressure of 1 to 10 bar gauge and a residence time of 20 minutes to 1 hour, and during which volatile products and a liquid residue are formed under the conditions of implementation of step b), c) a rapid cooling step of the volatile products, d) a withdrawal step of the liquid residue.

2. A conversion process according to claim 1, comprising, prior to step a), a plastic waste conditioning step comprising one or more operations of optical separation, grinding, chopping, screening, magnetic and / or eddy separation, centrifugation, density separation and / or agglomeration.

3. A conversion process according to claim 1 or 2, wherein the plastic waste comprises one or more of the following characteristics: - a mineral filler content measured according to ASTM D6375 of 0 to 7%, preferably 0 to 5% by mass, more preferably 1 to 2% by mass, the remainder being composed of polymers, - at least 80% by mass, preferably at least 85% by mass, more preferably at least 90% by mass, even more preferably at least 95% by mass, of polyolefins, - at most 20% by mass, preferably at most 10% by mass, more preferably at most 5% by mass, of aromatic polymers.

4. A conversion process according to any one of the preceding claims, wherein the residue has one or more of the following characteristics: - a xylene insolubles content measured according to ASTM D5630 of 0 to 7% by mass, preferably 0 to 3% by mass, more preferably 1 to 2% by mass, - the residue is liquid at temperatures from 90 to 180 °C, preferably from 90 to 140 °C, - a final melting temperature measured by thermal analysis, during a second heating ramp between -80 °C and 180 °C at 10 °C / min, ranging from 90 to 180 °C, preferably from 90 to 140 °C, - 40% to 70% by mass of the residue, preferably 40% to 60% by mass of the residue, has a boiling point of 650 °C or higher, preferably 660 °C or higher, in particular not exceeding 760 °C, according to ASTM D7169:20, - an initial boiling point of at least 250 °C measured according to ASTM D7169:20, - a boiling point at 20% by mass, measured according to ASTM D7169:20, of 530 to 580 °C, - a total metal content, measured according to IP 501, not more than 7% by mass, preferably not more than 1% by mass, more preferably not more than 8000 ppm by mass, and preferably not more than 5000 ppm by mass.

5. A conversion process according to any one of the preceding claims, wherein step b) comprises one or more of the following features: - step b) is carried out under an inert atmosphere, - step b) is carried out in the absence of a catalyst, - the temperature, pressure and residence time conditions of step b) are controlled so as to obtain a residue having a xylene insolubles content measured according to ASTM D5630 of 0 to 7% by mass, preferably 0 to 3% by mass, more preferably 1 to 2% by mass.

6. A conversion method according to any one of the preceding claims, wherein steps a) to d) are carried out continuously.

7. A conversion process according to any one of the preceding claims, further comprising one or more of the following steps: - a step of incorporating at least a part of the residue recovered in step d) into a bitumen base or a waterproofing membrane, - a step of visbreaking reduction of at least a part of the residue recovered in step d), alone or in a mixture with a fossil hydrocarbon feedstock, - a step of coking of at least a part of the residue recovered in step d), alone or in a mixture with a fossil hydrocarbon feedstock.

8. Thermal conversion residue of plastic waste, which can be obtained by the process according to any one of claims 1 to 6, said residue being liquid at temperatures from 90 to 180 °C, preferably from 90 to 140 °C, and of which 40% to 70% by mass, preferably 40% to 60% by mass, has a boiling point of 650 °C or more, preferably 660 °C or more, in particular not more than 760 °C, according to ASTM D7169:

20.

9. Thermal conversion residue according to claim 8, having one or more of the following characteristics: - a xylene insolubles content measured according to ASTM D5630 of 0 to 7% by mass, preferably 0 to 3% by mass, more preferably 1 to 2% by mass, - a final melting temperature measured by thermal analysis, during a second heating ramp between -80 °C and 180 °C at 10 °C / min, ranging from 90 to 180 °C, preferably from 90 to 140 °C, - an initial boiling point of at least 250 °C measured according to ASTM D7169:20, - a boiling point at 20% by mass, measured according to ASTM D7169:20, of 530 to 580 °C, - a total metals content, measured according to IP 501, not more than 7% by mass, preferably not more than 1% by mass, more preferably not more than 8000 ppm by mass, and preferably not more than 5000 ppm by mass.

10. Use of the thermal conversion residue according to claim 8 or 9 in a bituminous composition or in a waterproofing membrane.

11. Use of the thermal conversion residue according to claim 8 or 9 as a feed in a coking or visbreaking unit, alone or in a mixture with a fossil hydrocarbon feed.