Use of carbon generated during pyrolysis processes as a reducing agent in the production of co from co2 in plasma processes

Abstract

The present invention relates to a method for converting CO2 to CO, comprising the steps of: a) exposing a process gas comprising CO2 to a plasma source, whereby a plasma of said process gas comprising CO and O species is generated; b) contacting the plasma of said process gas comprising CO and O species with solid carbon, whereby a gas mixture comprising CO and CO2 is obtained; c) and quenching the gas mixture, whereby a product gas comprising CO and CO2 is obtained; wherein the solid carbon comprises pyrolytic carbon obtained by pyrolysis of i) plastic waste, preferably end-of-life tires (ELT) waste, mixed plastic waste (MPW), automotive-shredder-residue (ASR), plastic solid waste (PSW), present in municipal solid waste (MSW), electronic waste (E-waste) or mixtures thereof; ii) at least one kind of hydrocarbons; or iii) mixtures of i) and ii); and a process for preparing solid carbon, for converting CO2 to CO in a plasma process comprising the steps: A) pyrolyzing components i), ii) or iii) mentioned above, whereby pyrolytic carbon in form of primary particles is obtained; B) optionally further processing the pyrolytic carbon in form of primary particles obtained in step A); C) optionally mixing the pyrolytic carbon obtained in step A) or optionally obtained in step B) with at least one binder; and a reducing agent for a method for converting CO2 to CO by a plasma process comprising solid carbon, preferably in form of particles, being pyrolytic carbon obtained by pyrolysis of components i), ii) or iii) mentioned above.

Description

[0001]Use of carbon generated during pyrolysis processes as a reducing agent in the production of CO from CO2 in plasma processes The present invention relates to a method for converting CO2 to CO, comprising the steps of:a) exposing a process gas comprising CO2 to a plasma source, whereby a plasma of said process gas compris-ing CO and O species is generated;b) contacting the plasma of said process gas comprising CO and O species with solid carbon, preferably in formof carbon particles, whereby a gas mixture comprising CO and CO2 is obtained;c) and quenching the gas mixture, whereby a product gas comprising CO and CO2 is obtained;wherein the solid carbon comprises pyrolytic carbon obtained by pyrolysis ofi) plastic waste, preferably end-of-life tires (ELT) waste, mixed plastic waste (MPW), automotive-shredder-resi-due (ASR), plastic solid waste (PSW), present in municipal solid waste (MSW), electronic waste (E-waste) ormixtures thereof;ii) at least one kind of hydrocarbons, preferably natural gas, methane, ethane, propane, butane, pentane or mix-tures thereof, more preferably natural gas or methane; oriii) mixtures of i) and ii);and a process for preparing solid carbon, preferably in form of carbon particles, for converting CO2 to CO in a plasma pro- cess comprising the steps:A) pyrolyzing components i), ii) or iii) mentioned above, whereby pyrolytic carbon in form of primary particles isobtained;B) optionally further processing the pyrolytic carbon in form of primary particles obtained in step A), preferably byone or more of the following processing steps: Graphitization, purification, activation, chemical modification,carbonization, densification or surface coating;C) optionally mixing the pyrolytic carbon obtained in step A) or optionally obtained in step B) with at least onebinder; anda reducing agent for a method for converting CO2 to CO by a plasma process comprising solid carbon, preferably inform of particles, being pyrolytic carbon obtained by pyrolysis of components i), ii) or iii) mentioned above. Pyrolysis offers a promising route for valorizing plastic waste into fuels, chemicals, and byproducts while addressing the limitations of mechanical recycling and therefore has a great potential to achieve maximum economic and envi- ronmental benefits. Pyrolysis is performed by heating in the absence of oxygen at high temperatures (generally between 350 and900°C). Wherein “absence” in the meaning of the present application means no or essentially no oxygen.Generally, the pyrolysis process generates three different products(i) Oil (pyrolysis oil), e.g. hydrocarbons comprising paraffins, isoparaffins, olefins, naphthenes, and aromatics,(ii) gas (generally noncondensable; pyrolysis gas) with a high calorific value, and(iii) solids (pyrolytic carbon; pyC).The yields and characteristics of the obtained products depend on several parameters such as the raw material char- acteristics, the reactor design (size, fixed bed, fluidized bed, etc.), and the operating conditions (temperature, heating rate, and residence time). The pyrolysis oil is generally a viscous oil containing a mixture of condensed aromatic and aliphatic hydrocarbons and oxygenated compounds. It can be used as a fuel, for chemical production or as a starting material for refining. The pyrolysis gas is generally a combustible gas mixture of hydrocarbons such as methane, ethane, propene and other light hydrocarbons. This gas can be used as a fuel. One opportunity, but also a challenge, is the solid carbon that is generated during the process. It must be bound long-term to prevent the release of CO2. This can be achieved, for example, by using the material in the construction or materials industry, or in road construction. Alternatively, it could also be used to improve the properties of agricul- tural soils. However, in the large-scale (waste) pyrolysis, these carbon sinks can reach their capacity limits, which could ultimately limit the use of pyrolysis until other applications are found. WO 2020 / 016186 A1 describes the use of pyrolytic carbon obtained by pyrolysis of hydrocarbons for the production of anodes for aluminum production by electrolysis of aluminum ores (bauxite). WO 2023 / 117618 A1 relates to the use of a hydrophobic pyrolytic carbon obtained by pyrolysis of hydrocarbons with a density of 1 to 3 g / cc, a carbon content of 95 to 100 weight-%, and an ash content of 0.001 to 5 weight-%, wherein85 weight-% of the carbon is not functionalized, as a protective agent for macro- and megafauna.US 2015 / 0291433 A1 relates to a process and an apparatus for converting carbon dioxide CO2 into carbon monox-ide CO using hydrocarbons. WO2021 / 239831 A1 relates to a circular carbon process comprising a first step wherein hydrogen and carbon mon-oxide are reacted to produce methane and water, a second step wherein methane is decomposed into carbon andhydrogen, a third step wherein carbon is used as reducing agent and / or carbon is used in a carbon-containing mate-rial as reducing agent in a chemical process to produce carbon monoxide and a reduced substance, whereas themethane produced in the first step is used in the second step, whereas the carbon produced in the second step isused in the third step and carbon monoxide produced in the third step is used in the first step. In addition to the already known applications of pyrolytic carbon, there is a need for further applications for ecologi- cally and economically reasonable applications, especially for pyrolytic carbon from waste pyrolysis. It is therefore an object of the present invention to provide applications for pyrolytic carbon. The advantage of the ap- plication of pyrolytic carbon is, among other advantages, to close the carbon cycle. Less carbon loss in a sustainable carbon-based circular economy means fewer CO2emissions.The object is achieved by a method for converting CO2 to CO, comprising the steps of:a) exposing a process gas comprising CO2 to a plasma source, whereby a plasma of said process gas compris-ing CO and O species is generated;b) contacting the plasma of said process gas comprising CO and O species with solid carbon, preferably in formof carbon particles, whereby a gas mixture comprising CO and CO2is obtained;c) and quenching the gas mixture, whereby a product gas comprising CO and CO2 is obtained;wherein the solid carbon comprises pyrolytic carbon obtained by pyrolysis ofi) plastic waste, preferably end-of-life tires (ELT) waste, mixed plastic waste (MPW), automotive-shredder-resi-due (ASR), plastic solid waste (PSW), present in municipal solid waste (MSW), electronic waste (E-waste) ormixtures thereof;ii) at least one kind of hydrocarbons, preferably natural gas, methane, ethane, propane, butane, pentane or mix-tures thereof, more preferably natural gas or methane; oriii) mixtures of i) and ii).It has been found that the pyrolytic carbon obtained in the pyrolysis according to the invention is particularly efficient in the applications of the invention as described herein.US 4190636 A relates to the production of carbon monoxide directly from carbon dioxide and solid carbon at hightemperatures. Carbon monoxide is produced by delivering carbon dioxide to an arc so as to form a plasma, deliver- ing solid carbon to the plasma, and quenching the resultant products. Unreacted carbon may be filtered from the quenched products to yield carbon monoxide. Advantageously, one electrode may be made of solid carbon, which is consumed into the plasma, and which thus delivers some amounts of solid carbon into the plasma. Additional amounts of solid carbon may be added to the plasma. For example, carbon in powdered form, such as commercial lampblack, may be carried into the plasma by a stream of carbon dioxide.WO 2023 / 222708 A1 relates to method for converting CO2 to CO, comprising the steps of: i. providing process gascomprising CO2and optionally CO, to a plasma jet generator; ii. igniting a plasma in the process gas by the plasma jet generator, thereby obtaining a plasma jet comprising CO and O species; iii. introducing the plasma jet into a car- bon reaction chamber comprising carbon donor particles, thereby allowing O species in the plasma jet to preferen- tially bind with carbon to form CO; iv. extracting product gas from the carbon reaction chamber, said product gas comprising said CO and CO2, wherein the method further comprises the step of: v. recycling at least part of the prod- uct gas and providing said product gas comprising CO and CO2 to said plasma jet generator or to a second plasmajet generator. The carbon donor may preferably be natural coal, carbon black, activated coal, carbon fiber, cokes,etc. or any combination thereof. In the context of the present invention, the term "pyrolysis" relates to a thermal decomposition or degradation ofi) plastic waste, preferably end-of-life tires (ELT) waste, mixed plastic waste (MPW), automotive-shredder-resi-due (ASR), plastic solid waste (PSW), present in municipal solid waste (MSW), electronic waste (E-waste) ormixtures thereof;ii) at least one kind of hydrocarbons, preferably natural gas, methane, ethane, propane, butane, pentane or mix-tures thereof, more preferably natural gas or methane; oriii) mixtures of i) and ii),preferably a thermal decomposition or degradation ofi) plastic waste, preferably end-of-life tires (ELT) waste, mixed plastic waste (MPW), automotive-shredder-resi-due (ASR), plastic solid waste (PSW), present in municipal solid waste (MSW), electronic waste (E-waste) ormixtures thereof; oriii) mixtures of i) and at least one kind of hydrocarbons, preferably natural gas, methane, ethane, propane, bu-tane, pentane or mixtures thereof, more preferably natural gas or methane (ii)),generally under oxygen free conditions and results in a (generally noncondensable) gas, an oil and solids (pyrolytic carbon; PyC) fraction. During the pyrolysis, the hydrocarbons and / or plastics are converted into a great variety of chemicals including gases such as H2, C1-C4-alkanes, C2-C4-alkenes, ethyne, propyne, 1-butyne, pyrolysis oil having a boiling temperature ofgenerally 25° C to 500° C and pyrolytic carbon. The specific composition depends on the nature of the hydrocarbonsand / or plastics and the reaction conditions of the pyrolysis (e.g. temperature, pressure, presence of a catalyst).The pyrolytic carbon according to the present invention is obtained by any pyrolysis method known in the art for the pyrolysis ofi) plastic waste, preferably end-of-life tires (ELT) waste, mixed plastic waste (MPW), automotive-shredder-resi-due (ASR), plastic solid waste (PSW), present in municipal solid waste (MSW), electronic waste (E-waste) ormixtures thereof;ii) at least one kind of hydrocarbons, preferably natural gas, methane, ethane, propane, butane, pentane or mix-tures thereof, more preferably natural gas or methane; oriii) mixtures of i) and ii), preferably by any pyrolysis method known in the art for the pyrolysis ofi) plastic waste, preferably end-of-life tires (ELT) waste, mixed plastic waste (MPW), automotive-shredder-resi-due (ASR), plastic solid waste (PSW), present in municipal solid waste (MSW), electronic waste (E-waste) ormixtures thereof; oriii) mixtures of i) and at least one kind of hydrocarbons, preferably natural gas, methane, ethane, propane, bu-tane, pentane or mixtures thereof, more preferably natural gas or methane (ii)).Suitable pyrolysis processes for waste pyrolysis (or mixtures of plastic waste and hydrocarbons) are known in the artand for example described in WO 2010 / 127664 A1, US 4203804 A, EP 0035001 A2, Wilson Uzochukwu Eze et al.AIMS Clean Technologies and Recycling Volume 1, Issue 1, 50–69 and the literature mentioned therein. Suitablepyrolysis processes for hydrocarbon pyrolysis are known in the art and for example described in Stefan Schneider etal. ChemBioEng Rev 2020, 7, No.5, 150–158 (pyrolysis of natural gas), Amrit B. Sahu et al. Published by ElsevierInc. on behalf of The Combustion Institute; open access article under the CC BY license (http: / / creativecom-mons.org / licenses / by / 4.0 / ) (pyrolysis of hydrocarbons) and the literature mentioned therein.The pyrolysis process includes slow pyrolysis, fast pyrolysis and ultra-fast / flash pyrolysis. The processes are known in the art and especially differ in their heating rates. The fast pyrolysis is generally preferred for the pyrolysis of plas- tic waste according to the present invention. Slow pyrolysis (non-isothermal): Slow pyrolysis is the slow heating of the feedstock in absence of oxygen. Instead of combusting, the volatiles from the organic material evaporate partly, and a product (char) remains, consisting for a large part (normally 80%) of carbon. Slow pyrolysis is also called carbonization, and emphasizes the solid char asmain product, instead of fast pyrolysis which emphasizes the liquid product. Heating rates is kept at 10°C / s.Fast pyrolysis (Isothermal): Fast pyrolysis involves rapidly heating the feedstock to moderate temperatures (400– 600°C) at short residence time (few seconds) to yield high amount of pyrolysis liquid fuel. Fast pyrolysis provides a condition to maximize the production of the liquid, the reactor is considered to operate isothermally. It is the most common of the methods, both in research and in practical use in pyrolysis of plastics. Heating rates is kept at 100°C / s. Ultra-fast / flash pyrolysis: Ultra-fast, or flash pyrolysis is an extremely rapid thermal decomposition pyrolysis, with a high heating rate, the main products are gases and bio-oil. Heating rates can vary from 100–10,000°C / s and resi- dence times are short in duration. (See also: Wilson Uzochukwu Eze et al., AIMS Clean Technologies and Recycling Volume 1, Issue 1, 50–69) The pyrolysis includes thermal pyrolysis, catalytic pyrolysis, and microwave-assisted pyrolysis. The processes are known in the art. Thermal pyrolysis: Thermal cracking or pyrolysis involves the depolymerization or cracking of the plastics materialsby heating them to a very high temperature generally in the absence of oxygen or – in some embodiments - in lowoxygen environment. The temperature generally ranges from 350 to 900°C, preferably 400 to 850°C. The products formed include: gaseous, liquid (oil) and carbonized char (pyrolytic carbon (PyC)). The oil is usually recovered fromthe condensable fraction of the volatile product, while the remaining is a noncondensable high calorific value gas.Thermal pyrolysis is a thermochemical treatment (TCT) its oil product is generally a mixture of paraffins, isoparaffins, olefins, naphthenes, and aromatics. The residence time in the thermal pyrolysis varies depending on the specific process and the materials used. Typi- cally, the residence time is 1 min to 120 min, preferably 5 min to 90 min, more preferably 10 min to 60 min. Also, the pressure in the thermal pyrolysis varies depending on the specific process and the materials used. The pressure is typically 0.01 to 20 bar, preferably 0.1 to 10 bar. Catalytic pyrolysis: Catalytic pyrolysis involves the degradation of the polymeric materials by heating them generally in the absence of oxygen and in the presence of at least one catalyst. Catalysts are employed in plastic pyrolysis pri-marily to lower the energy requirement, influence the composition of the product through cracking and reduce theprocess time. Preferred catalysts for plastic waste pyrolysis include silica, alumina, silica-alumina, zeolites (e.g. HZSM-5 zeolite, ZSM-5 zeolite, Y zeolite), fluid catalytic cracking (FCC), mobil classification of materials (MCM) (e.g. MCM-41) or combinations thereof. High conversion is usually achieved with zeolite-based catalysts, like natural / modified zeolites, due to their high acid strength compared to nonzeolitic catalysts, as such tends to give more gaseous product. It is also possible to carry out the pyrolysis in one or more stages, e.g. in two stages using different catalysts or in one not catalyzed stage and one catalyzed stage. Effect of Catalyst Contact Mode: The pyrolysis according to the present invention can be carried out by two basic modes by which catalyst can be used in the pyrolysis of plastics in a reactor: liquid phase contact (in-situ) and vapor phase contact (ex-situ). In the former, the catalyst and polymer are mixed together, and then they are placed in the reactor and heated to appropriate reaction temperature. However, in the later, the polymer is first subjected to ther- molysis to produce the volatile fraction. The catalyst is introduced in the path of the moving vapor, and as the vaporpasses through the catalyst, the hydrocarbon vapor is cracked to get the required product distribution.Effect of polymer to catalyst ratio: The polymer to catalyst ratio has significant effect on both the yield and composi- tion of plastic pyrolysis products. With the increase in the amount of catalyst, a direct proportionality in terms of in- crease in conversion or general effectiveness is not obtained. The increase in catalyst amount increases the conver- sion up to particular limit, but a further increase in the catalyst percentage does not give any appreciable increase in the conversion rate. Generally, the polymer to catalyst weight ratio is from 0.01 to 0.3 : 1, preferably from 0.02 to 0.2 : 1. Effect of temperature: Temperature has a strong effect on the pyrolysis process, if the catalytic pyrolysis is taking place at higher operating temperature or at high heating rates, it enhances bond breaking as such tends to favour the production of smaller molecules. As the extent of conversion increases with increase in temperature, formation of gaseous product is improved with resulting decrease in liquid products. The effect of different catalysts on the liquid yield and the product distribution becomes less significant with increasing temperature this is because the reaction taking place becomes similar to thermal degradation. Basically, catalytic pyrolysis of plastics proceeds at much lowertemperature compared with thermal pyrolysis under the same process condition. Generally, the temperature in thecatalytic pyrolysis is 250 to 600°C, preferably 350 to 550°C. The exact residence time depends on factors such as the type of plastic, temperature, catalyst used, and specific process conditions. In general, the residence time in the catalytic pyrolysis is 3 sec to 60 min, preferably 5 sec to 30 min, more preferably 10 s to 15 min. Also, the pressure in the catalytic pyrolysis varies depending on the specific process and the materials used. The pressure is typically 0.01 to 15 bar, preferably 0.01 to 10 bar. Microwave-assisted pyrolysis: Microwave pyrolysis (also known as microwave-assisted pyrolysis) is pyrolysis that involves microwave dielectric heating. Microwaves interact in three ways with different materials; it is reflected by conductors, transmitted by perfect insulators, or absorbed and decayed on the way inside materials depending on their dielectric properties. The heat is generated in dielectric materials due to agitation of molecules by the alternating electromagnetic fields. The mechanism of plastic microwave pyrolysis is based on absorbing the microwave energy via absorbent and subsequently transferring thermal heat to the plastic via conduction. Typical microwave energies are 1 to 8 KW, preferably 1.8 to 6 KW. The exact residence time depends on factors such as the type of plastic, temperature, microwave energies, and spe- cific process conditions. In general, the residence time in the microwave-assisted pyrolysis is 1 min to 120 min, pref- erably 3 min to 90 min, more preferably 5 min to 80 min. The temperatures in microwave-assisted pyrolysis of waste can vary depending on the waste material and process parameters. Typically, a temperature range of 300 and 1100°C, preferably 400-800°C is targeted to achieve effective pyrolysis. However, the use of microwaves can lead to hot spots in the material, resulting in local temperatures ex- ceeding 1000°C. The pressure in microwave-assisted pyrolysis of waste is generally low to moderate and depends on the process conditions. The pressure can typically be maintained in the range of 0.1 to 20 bar, preferably 0.1 to 10 bar. Since mi- crowave pyrolysis is usually conducted at lower temperatures compared to conventional pyrolysis, the pressure gra- dient within the reactor is also lower. The physical properties and the volume ratio of the absorbent affect the uniformity of heating distribution. However, plastics cannot absorb microwave energy, as it has a very low dielectric loss factor. Therefore, an absorbent is gen- erally mixed with the plastic to aid in heating the plastic in pyrolysis. Materials with high dielectric loss factor are good candidates as absorbents for plastic pyrolysis e.g. tire shredded and silicon carbide, carbon, iron mesh. (See also: Wilson Uzochukwu Eze et al., AIMS Clean Technologies and Recycling Volume 1, Issue 1, 50–69) Further, the pyrolysis is carried out in any suitable reactor. Common reactors used for pyrolysis are rotary kilns, fixed bed, fluidized bed, moving bed, tubular and batch and semi-batch reactors. Plasma is also used for waste pyrolysis, which requires a specialized plasma reactor. Further, a liquid metal process may be used for pyrolysis, this also re-quires a specialized reactor. The reactors and processes are known in the art. Preferred reactors are fixed bed, fluid-ized bed, and moving bed reactors, more preferred are fluidized bed, and moving bed reactors. The pyrolysis process is carried out as batch, semi-batch or continuous process, depending, among others, on the type of waste. Fixed bed, fluidized bed, moving bed reactors: The catalyst is normally packed and palletized in a static bed in a fixed-bed reactor. The key advantage of these is their design simplicity, but on the other hand, there are some limitations, like the irregular shape and size of the plas- tic particles used as feedstock, which during the feeding process cause difficulties. Another disadvantage is that the reaction’s access to the catalyst’s usable surface area is limited. Preferably, fluidized bed or moving bed reactors are used in plastic pyrolysis processes. The reactor generally pro- vides constant temperature with high heat and mass transfer, reliable mean time distribution, and uniform products spectrum.In a fluidized bed reactor, the catalyst – in case of a catalytic pyrolysis – sits on a distributor plate through which thefluidizing gas moves and the particulates are held in a fluid state. Since the catalyst is mixed thoroughly with the sol- vent, there is greater accessibility to the catalyst, resulting in a wider surface area for the reactions to take place. With effective and viable heat transfer, this decreases process volatility. In a moving bed reactor, the material is kept in a (generally shallow) bed that is continuously in motion. The particles in the bed are fluidized at a specific velocity by gas pumped through it. Furthermore, when compared to batch reactors, the fluidized bed or moving bed reactor is more flexible as it does not require regular feedstock charging, which makes the process steady. Therefore, because of the lower operating cost, the fluidized bed or moving bed reactor is preferred as waste pyrolysis reactor. Batch and semi-batch reactors Batch reactors are the most basic reactors used in chemical reactions. They are closed systems that work in an un- steady state, which means that no reactants or products inflow or outflow are possible during the reaction. In batch reactors, high residence time means higher conversion rate, which is one of their main advantages. The downsides of batch reactors are high labor cost and the difficulty in maintaining extensive production. A semi-batch reactor, on the other hand, allows product removal and reactant addition at the same time. Concerning reaction selectivity, the semi-batch reactor has the advantage of being able to incorporate reactants over time. High labor cost and small- scale production are the main downsides of a semi-batch reactor. The batch reactors and semi-batch reactors are favorable and feasible to be utilized in waste plastics pyrolysis pro- cess because it is easy to monitor the parameters of these reactors which promote the high yield of liquid. These re- actors were however not appropriate for catalytic plastic pyrolysis due to the formation of coke on the outer surface of the catalyst which would affect the overall product composition. These reactors are only suitable for laboratory exper- iments because, on a large scale, it is difficult to maintain per unit of production. Spouted bed reactors The spouted bed reactor (CSBR) offers fine amalgamation and can accommodate a broad particle size distribution, different particle densities, and larger particles. The CSBR offers inconsiderable defluidization issues while pro- cessing sticky materials and also provides excellent heat transfer between the phases. However, the main down- sides of this reactor are product collection, entrainment and feeding of the catalyst, and high operating cost The present invention therefore further relates to the inventive electrode material, wherein the pyrolytic carbon is ob- tained by pyrolysis in fixed, moving or fluidized bed reactors, preferably in fluidized bed or moving bed reactors. According to the present invention, the pyrolytic carbon is obtained by pyrolysis ofi) plastic waste, preferably end-of-life tires (ELT) waste, mixed plastic waste (MPW), automotive-shredder-resi-due (ASR), plastic solid waste (PSW), present in municipal solid waste (MSW), electronic waste (E-waste) ormixtures thereof;ii) at least one kind of hydrocarbons, preferably natural gas, methane, ethane, propane, butane, pentane or mix-tures thereof, more preferably natural gas or methane; oriii) mixtures of i) and ii),preferably by pyrolysis ofi) plastic waste, preferably end-of-life tires (ELT) waste, mixed plastic waste (MPW), automotive-shredder-resi-due (ASR), plastic solid waste (PSW), present in municipal solid waste (MSW), electronic waste (E-waste) ormixtures thereof; oriii) mixtures of i) and at least one kind of hydrocarbons, preferably natural gas, methane, ethane, propane, bu-tane, pentane or mixtures thereof, more preferably natural gas or methane (ii)).In the meaning the present invention, plastic (or plastics) means a polymer material to which additives or substances may have been added. IUPAC defines a polymer as a “molecule of high relative molecular mass, the structure of which essentially comprises the multiple repetition of units derived, actually or conceptually, from molecules of low relative molecular mass”. (International Union of Pure and Applied Chemistry. Compendium of polymer terminology and nomenclature: IUPAC recommendations, 2008; RSC Pub.: Cambridge, 2009; p 443.). Plastic waste generally refers to any plastic material discarded after use, e.g., plastic material having reached the end of its useful life, considered post-consumer waste, as well as post-industrial waste. The plastic waste can bepure polymeric plastic waste, mixed plastic waste or film waste, including soiling, adhesive materials, fillers, residuesetc. The plastic waste may have an oxygen content, a nitrogen content, sulfur content, halogen content and option- ally also a heavy metal content. The plastic waste can originate from any plastic material containing source. In an- other aspect, the term “plastic waste” also includes production waste e.g., from polymer processing in factories. Accordingly, the term “plastic waste” includes industrial and domestic plastic waste and including used tires and agri- cultural and horticultural plastic material. Typically, plastic waste is a mixture of different plastic materials, including hydrocarbon plastics, e.g., polyolefins such as polyethylene (HDPE, LDPE) and polypropylene, polystyrene, and copolymers thereof, etc., and polymers composed of carbon, hydrogen, and other elements such as chlorine, fluorine, oxygen, nitrogen, sulfur, silicone, etc., for example chlorinated plastics, such as polyvinylchloride (PVC), polyvinylidene chloride (PVDC), etc., nitrogen-con- taining plastics, such as polyamides (PA), polyurethanes (PU), acrylonitrile butadiene styrene (ABS), etc., oxygen- containing plastics such as polyesters, e.g., polyethylene terephthalate (PET), polycarbonate (PC), etc., silicones and / or sulfur bridges crosslinked rubbers. Typically, the plastic material comprises additives, such as processing aids, plasticizers, flame retardants, pigments, light stabilizers, lubricants, impact modifiers, antistatic agents, antioxidants, etc. These additives may comprise ele- ments other than carbon and hydrogen. For example, bromine is mainly found in connection to flame retardants. Heavy metal compounds may be used as lightfast pigments and / or stabilizers in plastics. Cadmium, zinc, and lead may be present in heat stabilizers and slip agents used in plastics manufacturing. The plastic waste can also contain residues. Residues in the sense of the invention are contaminants adhering to the plastic waste. The additives and residues are usually present in an amount of less than 50 wt.-%, preferably less than 30 wt.-%, more preferably lessthan 20 wt.-%, even more preferably less than 10 wt.-%, based on the total weight of the dry weight plastic.Examples of rubber waste (which is also considered “plastic waste” in the sense of the present invention) include end-of-life tires, rubber waste produced during manufacturing processes and discarded rubber containing products such as latex examining gloves and gaskets. The plastic waste may generally be any kind of plastic waste, preferably end-of-life tires (ELT), mixed plastic waste (MPW), automotive-shredder-residue (ASR), plastic solid waste (PSW), present in municipal solid waste (MSW), electronic waste (E-waste) or mixtures thereof. Mixed plastic waste (MPW) is generally post-consumer plastic packaging waste. It generally has a complex and un- predictable composition (due to high polymer heterogeneity, additives, and contaminants). MPW for example com-prises 50 to 80 wt% of different kinds of plastics, e.g. LDPE, HDPE, PP, PET, PS, EPS, PVC, ABS and 20 to 50 wt%of other fractions (metals, textiles, paper, and inert materials). One example for MPW is the waste from the German yellow bag. One example for MPW is shown in Table 1 in F. Ardolino et al., Waste Management 171 (2023) 662– 675. The table shows a fractional and elementary composition of a reference MPW, composed by 70% of not recy- clable plastic packaging and 30% of other fractions. Said reference waste composition derived from that estimated by Lase et al. (2023) (Lase, et al., 2023. How much can chemical recycling contribute to plastic waste recycling in Eu- rope? An assessment using material flow analysis modelling. Res. Cons. Rec.192, 106916 https: / / doi.org / 10.1016 / j.resconrec.2023.106916. - accessed on April 15, 2024), which is representative of post-consumer plastic packaging waste currently not recycled in Europe and obtained by a material flow analysis (MFA) implemented at European scale. This waste stream contains other fractions (polymers from other sectors, metals, textiles, paper, and inert materials), whose amount and typology are obtained from direct measurements carried out by the Italian Na- tional Consortium for the Collection and Recycling of Plastic Packages (Corepla, 2023. Italian National Consortiumfor the Collection and Recycling of Plastic Packages (https: / / www.corepla.it / en - accessed on April 15, 2024). Per-sonal communication by A. Furiano and D. Pollon.) The automotive shredder residue (ASR) may be obtainable, preferably is obtained, by shredding vehicles. Preferably, the automotive shredder residue is obtainable by depollution of the vehicles, dismantling the vehicles, shredding the vehicles, and separating metal particles from the shredded vehicles. The vehicles are typically end-of-life vehicles (also called “ELV”), which are typically at least 15 years old. The vehi-cles can be passenger cars, light-duty or heavy-duty trucks, motorbikes, a utility vehicle, an agricultural vehicle, orrecreational vehicles. The vehicle can be an electric vehicle, such as a fully electric vehicle or a hybrid electric vehi- cle.In depollution of vehicles hazardous liquids such as fuel, lubricating oil, coolants, brake fluids and batteries can beremoved from the vehicles prior to shredding.The dismantling of vehicles may comprise selective removal of parts, such as engines, gearboxes, tires, glass andplastics, for being reused as spare parts for the second-hand market. The dismantling may also comprise the re- moval of larger plastic components, such as bumpers, dashboard, fluid containers for recycling the plastics sepa- rately. The ASR may comprise further waste from other sources. For examples, garbage from the last owners may remain in the trunk or interior of the vehicles. The advantage of the present process is that it can handle broadly varying compositions of the ASR. The shredding can be made with a vehicle shredder machine. Vehicle shredder machines are manufactured in differ- ent sizes. Typically, a vehicle shredder machine comprises a heavy fast-turning rotor, which may revolve in a vertical or a horizontal plane and is often equipped with swinging hammers. The vehicle shredder machine tears and shreds the car hulk until its parts are reduced to fragments with a desired fragment size, such as up to 30 cm, preferably 1 mm to 15 cm. Then the fragments may pass through grids and leave the rotor housing.After shredding, the metal fragments such as ferrous and non-ferrous metal fragments can be separated from theshredded vehicles. The ferrous metal fragments can be removed by magnetic separators. The non-ferrous metalfragments can be separated from the shredded vehicles by eddy current separators, by heavy media sink / float unitswhich separate on the basis of density, or by manual sorting. Typically, 60 – 90 wt% of the vehicle weight is metal,which can be separated from the shredded vehicle.The automotive shredder residue may represent about 10 - 40 wt%, preferably from 15 - 35, and in particular from 20– 30 wt% of the original vehicle weight.The automotive shredder residue may comprise fragments of various polymeric vehicle parts, such as fragments ofbumpers, interior panels, dashboard, cable insulation, fuel tank, electrical insulation, flexible foam seating, foam insu- lation panels, automotive suspension bushings, electrical potting compounds, car body parts, pillar coverings, spoil- ers polymer parts coated with automotive paint, wheel covers, gears, bushes, cams, bearings, weatherproof coat- ings, interior and exterior trims, fuel systems, gear housings, headlamp retainer, engine cover, connector housings, door handles, carburetor components, exterior mirror components, windscreen wiper components, windscreen wiper protective housings, decorative grilles, cover strips, roof rails, window frames, sliding roof frames, antenna cladding covers, front and rear lights, radiator grill and body exterior parts, engine covers, cylinder head covers, intake pipes, cylinder head covers, engine covers, housings for charge air coolers, charge air cooler valves. The automotive shredder residue may comprise fragments of various polymeric vehicle parts, such as fragments of- bumpers, interior panels, dashboard, cable insulation, where these fragments are often made of polypropylene;- fuel tank, electrical insulation, where these fragments are often made of polyethylene;- flexible foam seating, foam insulation panels, automotive suspension bushings, electrical potting compounds,hard plastic parts, transmission mounts, motor mounts, seals, impact foam parts, where these fragments are of- ten made of polyurethane;- body parts, dashboards, wheel covers, where these fragments are often made of acrylonitrile-butadiene-styrene;- gears, bushes, cams, bearings, charge air coolers, cylinder head covers, oil pans, engine cooling systems, ther-mostat and heater housings, exhaust systems including mufflers and housings for catalytic converters, air intake manifolds, timing chain belt front covers, where these fragments are often made of nylon 6 or nylon 6.6.;- interior and exterior trims, fuel systems, small gears, where these fragments are often made of polyoxymethylene;- wiper arm and gear housings, headlamp retainer, connector housings, where these fragments are often made ofpolyethylene terephthalate; and- door handles, bumpers, carburetor components, where these fragments are often made of polybutylene tereph-thalate. The automotive shredder residue may comprise at least 30 wt%, preferably at least 40 wt%, and in particular at least50 wt% of the fragments of the polymeric vehicle parts.The automotive shredder residue may comprise at least 20 wt%, preferably at least 30 wt%, and in particular at least40 wt% of the fragments of the polymeric vehicle parts, which are black polymeric vehicle parts. The black polymericvehicle parts usually comprise carbon black pigments. The automotive shredder residue may comprise up to 15 wt%, preferably up to 10 wt%, and in particular up to 5 wt% of metal fragments, such as ferrous and non-ferrous metal particles. The automotive shredder residue may comprise up to 15 wt%, preferably up to 10 wt%, and in particular up to 5 wt% of wood and cardboard. The automotive shredder residue may comprise up to 15 wt%, preferably up to 10 wt%, and in particular up to 5 wt% of glass fragments, e.g. broken window glass fragments. The automotive shredder residue can be separated into a shredder light fraction (also called SLF) and a shredder heavy fraction (also called SHF). The separation of the SLF and the SHF can be achieved by air classification. An- other air classification can be made by the rotary movement of the vehicle shredder machine may create a fanningaction that can blow out the shredder light fraction, and the shredder heavy fraction may leave the vehicle shreddermachine through a grid.The SLF can be present in an amount of 55 - 90 wt%, preferably 65 - 85 wt%, and in particular at 70 - 80 wt% of theautomotive shredder residue. The SHF may represent the remaining amount to 100 wt%.The SHF can be present in an amount of 10 - 45 wt%, preferably 15 - 35 wt%, and in particular at 20 - 30 wt% of theautomotive shredder residue. The SLF may represent the remaining amount to 100 wt%. The SLF usually contains a lower weight percentage of rubber particles than the SHF. The SLF usually contains a lower weight percentage of glass particles than the SHF. The SLF usually contains a lower weight percentage of metal particles than the SHF. The SLF usually contains a higher weight percentage of polyurethane foam particles than the SHF. The SLF usually contains a lower weight percentage of solid and sand than the SHF.Figure 1 shows a possible flow scheme with a suitable process sequence for obtaining the automotive shredder resi-due. Starting from the vehicles, followed by optional depollution, followed by optional dismantling, followed by shred- ding the vehicles, followed by optional separating the metal fragments from the shredded vehicle, then the ASR is obtained, followed by optional separation of the ASR in shredder light fraction and shredder heavy fraction. According to https: / / www.etrma.org / wp-content / uploads / 2019 / 09 / appendices-a-framework-for-effective-elt-manage-ment-systems-final-25.6.10.pdf - accessed on April 15, 2024, End of life tire (ELT) is defined as follows:“a tire that can no longer be used for its original purpose; all tires including passenger car, truck, airplane, agricul- tural, 2-wheel & off-road tires result in ELTs; however, most ELTs result from car and truck tires”.Tires are not made only of rubber, which generally represents 35 to 55 wt%, e.g. around 45 wt% of their mass, butalso for example of steels belts, textile overlays, reinforcing fillers and / or additives. The rubber fraction of tires is nat-ural rubber and / or synthetic rubber (mainly butadiene rubber and styrene-butadiene rubber). The composition of pas-senger car and truck tires differs mainly for the higher natural rubber content present in truck tires.In Table 1 in F. Valentini, A. Pegoretti, Advanced Industrial and Engineering Polymer Research 5 (2022) 203-213 anAverage composition of fuel-efficient passenger car and truck tyres is mentioned: Plastic solid waste (PSW) could be categorized depending on its source or point of origin, i.e. municipal, industrial, medical, etc. However, the majority of PSW is generated from households and commercial sources which combined are referred to as municipal plastic waste (MPW) (see above). This type of SW (solid waste) constitutes mainly the following plastic resin types: polyethylene (PE), polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET) and polyvinyl alcohol (PVC) (Miandad et al., 2017). MPW are typically thermoplastics which are thermally recy- clable due to their non-resistance to heat nature. According to the ISO 15270 (2008), PSW could be recycled and treated to produce raw materials and the productions of high calorific compounds which could be used as fuels for energy production. The management of PSW in general will rid the environment of the accumulation of PSW and prevent pollution problems from landfilling such as toxins leaching that can contaminate ground water aquifers (Al-Salem et al., 2015) (see Achilleas Constantinou et al. “Plastic Solid Waste (PSW) in the Context of Life Cycle As-sessment (LCA) and Sustainable Management”, 2019). In a European Commission Proposal for a directive of the European parliament and the council amending directive2008 / 98 / EC on waste, vol.275; 2015, municipal solid waste (MSW) is defined as:“(a) mixed waste and separately collected waste from households including: paper and cardboard, glass, metals, plastics, bio-waste, wood, textiles, waste electrical and electronic equipment, waste batteries and accumulators; bulky waste, including mattresses and furniture; garden waste, including leaves, grass clipping; (b)mixed waste andseparately collected waste from other sources that is comparable to household waste in nature, composition andquantity; (c) market cleansing waste and waste from street cleaning services, including street sweepings, the content of litter containers, waste from park and garden maintenance.” Generally, MSW comprises 5 to 20 wt% of plastics of all kinds like LDPE, HDPE, PP, PET, PS, EPS, PVC, ABS.Electronic waste (E-waste) is any electrical or electronic equipment that has been discarded. This includes workingand broken items that are thrown away. E-waste is particularly dangerous due to toxic chemicals that naturally leach from the metals inside when buried. Common E-waste items are for example home appliances like microwaves, home entertainment devices, electric cookers, heaters, fans, communications and information technology devices like cell phones, smartphones, desktop computers, computer monitors, laptops, circuit boards, hard drives, home entertainment devices like DVDs, Blue Ray Players, stereos, televisions, video game systems, fax machines, copiers, printers, electronic utilities like massage chairs, heating pads, remote controls, television remotes, electrical cords, lamps, smart lights, night lights, treadmills fitness watches, smart watches, heart monitors, diabetic testing equipment, office and medical equipment like copi- ers / printers, IT server racks, IT servers, cords and cables, WiFi dongles, dialysis machines, imaging equipment, phone & PBX systems, audio & video equipment, network hardware (i.e. servers, switches, hubs, etc.), power strips & power supplies, uninterrupted power supplies (UPS Systems), power distribution systems (PDU’s), autoclave, de- fibrillator. However, the definition of E-waste is likely to keep expanding. In an era of rapid technological advance- ment, more and more highly sophisticated electronic goods are being invented and manufactured. E-waste generally contains some form of toxic materials, e.g. beryllium, cadmium, mercury, and lead. Said toxic ma- terials pose serious environmental risks to our soil, water, air, and wildlife. When E-waste gets buried at a landfill, it can dissolve in microscopic traces into the gross sludge that permeates at the landfill. Eventually, these traces of toxic materials pool into the ground below the landfill. This is known as leach- ing. The more E-waste and metals at the landfill, the more of these trace toxic materials show up in the groundwater. The recycling of E-waste therefore serves a lot of useful purposes. Virtually all electronic waste contains some form of recyclable material. That includes materials like plastic, glass, and metals. Pre-treatment (optional): Optionally, the feedstock is pre-treated before entering the pyrolysis reactor. Generally, pre-treatment steps of plastic waste are known in the art. A suitable pre-treatment method or combination of pre-treatment methods in a pre-treat- ment unit should preferably provide a sufficiently homogeneous carbon-based feedstock to the pyrolysis reaction and likewise enable a preferably continuous pyrolysis of the feedstock. A pre-treatment method or a combination of more than one pre-treatment methods in a pre-treatment unit preferably results in a homogenization of the physical and / or chemical properties of the feedstock. The pre-treatment method for the feedstock is preferably selected from the group comprising drying, comminution, classification, sorting, agglomeration, thermochemical methods, and biological methods. Thermochemical methods comprise torrefaction. In case the water content of a feedstock is too high, the preferred pre-treatment method for reducing the water con- tent of the feedstock is drying. In case the particle size of a feedstock is too large, the preferred pre-treatment method is selected from the group comprising grinding, shredding, milling, sieving and combinations thereof. In case the particle size of a feedstock is too small, the preferred pre-treatment for increasing the size of a feedstock is se- lected from the group comprising agglomeration, pelletizing, sieving, and combinations thereof. Preferably, the feedstock is pelletized prior to pyrolysis. Suitable kinds of hydrocarbons are any hydrocarbon comprising compounds known in the art. Preferred hydrocarbon comprising compounds comprise light hydrocarbons, preferably gaseous C1-C5 alkanes, more, preferably natural gas, methane, ethane, propane, butane, pentane or mixtures thereof, even more preferablynatural gas or methane (C1 alkane). Preferably the hydrocarbons are in form of natural gas, associated gas, industryoff-gas and / or biogas / biomethane. Such feed streams typically comprise light hydrocarbons like methane, ethane, ethylene, propane, propylene and butane, carbon monoxide and carbon dioxide, inert gases like nitrogen, and sulfur components. The natural gas, depending on the natural gas reservoir, typically has the following composition: 60% and 99% Vol.- % of methane, 1 to 15 Vol.-% of C2-C4 alkanes, up to 20 Vol.-% sulfur components and up to 30 Vol.-% inert gases, especially nitrogen. Depending on the pipeline specifications, up to 20 Vol.-% of hydrogen might be added to the nat- ural gas. The associated gas typically comprises methane, ethane, ethylene, propane, propylene and butane and having the following composition: from 75 to 85% by volume of methane, from 1 to 10% by volume of ethane, from 1 to 10% by volume of propane, from 1 to 10% by volume of butane, from 0.1 to 5% by volume of nitrogen, from 0.1 to 10 % by volume of sulfur compounds and from 0 to 1% by volume of carbon dioxide. The biogas / biomethane typically has the following composition: from 50 to 75% by volume of methane, from 25 to 50% by volume of CO2, from 0 to 10 % by volume of sulfur compounds and from 0 to 10% by volume of N2. Preferred hydrocarbons ii) are natural gas, methane, ethane, propane, butane, pentane or mixtures thereof, morepreferably natural gas or methane.According to the present invention, the pyrolytic carbon is obtained by pyrolysis of exclusively plastic waste, prefera- bly end-of-life tires (ELT) waste, mixed plastic waste (MPW), automotive-shredder-residue (ASR), plastic solid waste(PSW), present in municipal solid waste (MSW), electronic waste (E-waste), exclusively of hydrocarbons, preferablynatural gas, methane, ethane, propane, butane, pentane or mixtures thereof, more preferably natural gas or methaneor mixtures thereof, orpyrolysis of mixtures of plastic waste with at least one kind of hydrocarbons. The ratio of the plastic waste and atleast one kind of hydrocarbons is generally not critical. The weight ratio of plastic waste and at least one kind of hy- drocarbons is for example from 99:1 to 1:99.Since the pyrolytic carbon directly obtained by the pyrolysis process described above is optionally further processedbefore the inventive application, the carbon particles obtained directly in the pyrolysis process are referred to as pri- mary particles.Generally, the specific nature of the pyrolytic carbon (pyC) obtained directly from the pyrolysis (primary particles) de-pends on the pyrolysis process and on the feedstock used. Preferably, the primary particles are in form of granular carbon, carbon black or carbon powder. The pyrolytic carbonemployed in the method according to the present invention therefore preferably comprises or consists of pyrolyticcarbon directly obtained from pyrolysis as primary particles in form of granular carbon, carbon black or carbon pow- der. More preferably, the pyrolytic carbon directly obtained from pyrolysis as primary particles has at least one of the fol- lowing properties, preferably all of the following properties:- a BET surface area of 10 to 400 m2g-1, preferably 15 to 300 m2g-1, more preferably 40 to 150 m2g-1;- a carbon content of at least 80 wt%, preferably 85 wt% to 100 wt%, more preferably 86 wt% to 98 wt%; mostpreferably 90 wt% to 97 wt%;- a particle diameter D50 of at least 0.05 mm; preferably 0.05 mm to 4 mm, more preferably at least 0.5 mm,most preferably 0.5 mm to 4 mm;- a density of 1 to 3.5 g / cm3, preferably 1.8 to 2.2 g / cm3.Further more preferably, the pyrolytic carbon directly obtained from pyrolysis as primary particles has at least one of the following properties, preferably all of the following properties:- a BET surface area of 40 to 150 m2g-1;- a carbon content of at least 80 wt%, preferably 85 wt% to 100wt%, more preferably 86 wt% to 98 wt%; mostpreferably 90 wt% to 97 wt%;- a particle diameter D50 of at least 0.5 mm, preferably 0.5 mm to 4 mm;- a density of 1.8 to 2.2 g / cm3.The present invention therefore more preferably relates to the inventive method, wherein the pyrolytic carbon directly obtained from pyrolysis as primary particles has at least one of the following properties, preferably all of the following properties:- a BET surface area of 10 to 400 m2g-1, preferably 15 to 300 m2g-1, more preferably 40 to 150 m2g-1;- a carbon content of at least 80 wt%, preferably 85 wt% to 100wt%, more preferably 86 wt% to 98 wt%; mostpreferably 90 wt% to 97 wt%;- a particle diameter D50 of at least 0.05 mm; preferably 0.05 mm to 4 mm, more preferably at least 0.5 mm,most preferably 0.5 mm to 4 mm;- a density of 1 to 3.5 g / cm3, 1.8 to 2.2 g / cm3.The present invention therefore further more preferably relates to the inventive method, wherein the pyrolytic carbon directly obtained from pyrolysis as primary particles has at least one of the following properties, preferably all of the following properties:- a BET surface area of 40 to 150 m2g-1;- a carbon content of at least 80 wt%, preferably 85 wt% to 100wt%, more preferably 86 wt% to 98 wt%; mostpreferably 90 wt% to 97 wt%;- a particle diameter D50 of at least 0.5 mm, preferably 0.5 mm to 4 mm;- a density of 1.8 to 2.2 g / cm3. In the meaning of the present application, the “carbon content” is generally the dry and ash free carbon content. The density is in the meaning of the present application generally the material density. The BET (Brunauer–Emmett–Teller) method is the standard technique used to determine the specific surface area, relying on the physical adsorption of gas molecules—usually nitrogen—on the sample surface. Determination Norm: The standard method is ISO 9277:2020 (“Determination of the specific surface area of solids bygas adsorption — BET method”).The dry and ash-free carbon content of a sample is determined by measuring the carbon C, moisture W and inor-ganic ash content from the sample and calculating the carbon fraction for the dry and ash free sample.Determination Norm: The standard determination of elemental carbon content is performed following ASTM D5373- 21 (“Standard Test Methods for Instrumental Determination of Carbon, Hydrogen, and Nitrogen in Laboratory Sam- ples of Coal and Carbonaceous Material”). For ash content, ASTM D3174-20 (“Ash in the Analysis Sample of Coal and Coke from Coal”) can be used, and moisture is typically determined by ASTM D3173-21 (“Moisture in the Analy- sis Sample of Coal and Coke from Coal”). The “dry and ash-free” basis is then calculated after correcting for water and ash, i.e. Cdaf by Cdaf = 100 * C / (1-W-A), all values in wt%. Material (true) density of pyrolytic carbon particles: Determination Norm: Density is most precisely measured by helium pycnometry following ASTM D2854-21 (“Stand- ard Test Method for Apparent Density of Activated Carbon”). The particle diameter “D50” is also called median particle diameter or median particle size. For example, for a pow- der sample with D50 = 5µm, it means 50% of particles are larger than 5 µm and 50% particles are smaller than 5µm. The D50 can be assessed as a sample size of an SEM (scanning electron microscope) image (DIN66133:2003), such as assessing D50 as a median particle size of 20 or more particles, or measured with a laserscattering particle size analyzer (according to ISO 13320:2020). Sieve analysis may also be used for larger particlesizes, as described in ASTM D6913 / D6913M-17 (“Particle-Size Distribution (Gradation) of Soils Using Sieve Analy- sis”). The primary particles directly obtained from the pyrolysis preferably may be purified. Suitable processes are known inthe art and for example described in US 2020339819 A1.Further, as mentioned above, the preferably purified primary particles may in one embodiment of the invention furtherprocessed. Examples for further processing step are one or more of the following processing steps: Graphitization,purification, activation, chemical modification, carbonization, densification or surface coating. All processes areknown in the art. Suitable further processing of the pyrolysis char is for example described in US 20210317318 A1. Generally, the solid carbon employed in the inventive method comprises the pyrolytic carbon described above.In addition to the pyrolytic carbon described above, further carbon material can be present in the solid carbon, e.g.carbon black, carbon nano tubes (CNT) or a combination thereof. The solid carbon comprises the pyrolytic carbondescribed above generally in an amount of 10 to 100 wt%, preferably 20 to 98 wt%, more preferably 51 to 95 wt%,based on the total amount of the solid carbon. Further components in said solid carbon may be carbon materials as mentioned above and / or binders as mentioned below. In one embodiment of the present invention, the solid carbon consists of the pyrolytic carbon described above.The solid carbon employed in step b) of the inventive method is crucial for its performance. A relevant factor is agood fluidizability. It has been found by the inventor that the pyrolytic carbon obtained according to the present invention effectively helps to improve the fluidizability of the solid carbon.A general description of plasma technology for CO2 conversion is given in Annemie Bogaerts et al. Front. EnergyRes., 07 July 2020, Sec. Carbon Capture, Utilization and Storage, Volume 8 – 2020 (https: / / doi.org / 10.3389 / fenrg.2020.00111) and the literature mentioned therein.A plasma is according to Bogaerts et al. also called the “fourth state of matter,” and is an ionized gas consisting of electrons, various types of ions, radicals, excited atoms, and molecules, besides neutral ground state molecules. Plasma is created by applying electricity to a gas. The light electrons are heated by the applied electric field, and they activate the gas molecules by excitation, ionization, and dissociation, creating the above-mentioned reactive species and allowing chemical reactions to occur at mild conditions (generally ambient temperature and pressure). Step a) of the inventive method comprises: Exposing a process gas comprising CO2 to a plasma source, whereby a plasma of said process gas comprising CO and O species is generated.Suitable plasma sources are known in the art and described in the literature mentioned above. Preferably, theplasma source is selected from the group consisting of a plasma jet generator, a plasma torch, a microwave plasma source, an induction plasma source, arc discharges, glow discharges, and dielectric barrier discharges, preferably a plasma jet generator or an arc discharge, more preferably a plasma jet generator. The plasma sources mentioned before are known in the art. In a more preferred embodiment, the plasma jet generator is chosen from the group consisting of: gliding arc (GA), glow discharge (GD), microwave discharge (MW), radiofrequency discharge (RF), capacitive coupled discharge(CCD) or dielectric barrier discharge, preferably gliding arc (GA) and glow discharge (GD), most preferably glidingarc. In a further preferred embodiment, the plasma jet generator is chosen from a Gliding Arc Plasmatron (GAP), ii. a Dual-Vortex Plasmatron (DVP), or iii. an Atmospheric Pressure Glow Discharge (APGD) plasma generator. These plasma generators are known in the art and differ in their main performance characteristics, i.e. conversion and energy efficiency, as discussed below. The gliding arc plasmatron (GAP) GAP (generally reverse-vortex flow (RVF) stabilized GAP) is a medium to high-powered (generally 500-800W) at- mospheric plasma source, with established conversion performance generally around 6-7% (for pure CO2 splitting) and energy efficiency generally up to 32%, and generally 15% conversion with generally 65% energy efficiency for dry reforming of methane. The atmospheric pressure glow discharge (APGD) The APGD on the other hand can deliver higher conversion (generally around 13%), but its energy efficiency is lim- ited (generally 25%). However, the lower energy efficiency is not a limiting factor in all cases. In a situation where heat recovery is desirable, the lower energy efficiency means that more heat will be available to be recovered from the gas and supplemented to the main process. Furthermore, if the electricity price is low at a given moment (peak trimming of renewable sources), the lower energy efficiency becomes less of a problem, while the high conversion is beneficial. APGD is a low to medium-powered (generally 100-200 W) atmospheric plasma reactor. In its lab scale, the CO2 con- version reaches around 13% with energy efficiency of 25%. Dual-vortex plasmatron (DVP) The DVP can deliver medium conversion (generally 9-10%) at high energy efficiency. This means that it will utilize a larger part of the electrical energy towards CO2 splitting, potentially saving on electricity costs. DVP atmospheric plasma reactor is a type of a GA discharge generally employing simultaneous vortex and reverse-vortex flow stabilization. It is capable of CO2 conversion rate generally around 9.5% and efficiency generally up to41% with generally 450W of power.Since the GAP, DVP and the APGD can run on the same type of power source, the plasma source of the presentinvention may preferably comprise a combination of the three variations. Preferably, the plasma jet is obtained at about atmospheric pressure. Atmospheric pressure refers to a pressureclose to 1 atm, preferably from 500 to 5000 hPa, more preferably at least 900 hPa, still more preferably at least 950hPa, and / or more preferably at most 1100 hPa, still more preferably at most 1070 hPa, most preferably from 970 hPato 1050 hPa, such as around 1013 hPa.According to the present invention, carbon monoxide and oxygen species are produced by delivering a process gascomprising carbon dioxide (CO2) to an arc so as to form a plasma. Suitable reaction conditions are mentioned above.In one preferred embodiment of the invention, the process gas comprises at least 80wt% of CO2 based on the total amount of process gas employed in step a). Preferably, said process gas comprises at least 90wt% of CO2 based on the total amount of process gas employed in step a), more preferably at least 95wt% of CO2 based on the total amount of process gas employed in step a). Preferably, the process gas employed in step a) comprises up to 100wt% CO2. Process gas employed in step a), as used herein, refers to fresh process gas, without recycled part of the product gas, which may optionally be present. However, as purification of CO2is a very energy and equipment intensive process, using exhaust streams comprising a high amount of CO2with minimal purification can be em-ployed and may be preferred from an energetic point of view. The process gas may therefore for example comprisein addition to carbon dioxide one or more of the following compounds: Nitrogen, argon, oxygen, hydrogen, CO, hy-drocarbons, nitrogen oxides, sulfur, sulfur oxides or hydrocarbons comprising sulfur.In one preferred embodiment of the method according to the present invention, a part of the product gas, especiallyat least a part of the CO2 in the product gas, is recycled into the method (generally into step a)).In said embodiment of the invention, with a recycled part of the product gas, the process gas preferably comprisesCO2 and CO in a ratio by weight of at most 9 / 1, more preferably at most 8 / 2, more preferably at most 7 / 3, more pref- erably at most 6 / 4, more preferably at most 5 / 5. In another preferred embodiment of the invention, the process gas comprises CO2 and CO in a ratio by weight of at least 1 / 9, more preferably at least 2 / 8, more preferably at least 3 / 7, more preferably at least 4 / 6, more preferably at least 5 / 5. In another embodiment, the process gas comprises CO2and CO in a ratio from 1 / 9 to 9 / 1, more preferably in a ratio from 2 / 8 to 8 / 2, more preferably in a ratio from 3 / 7 to 7 / 3,more preferably in a ratio from 4 / 6 to 6 / 4, most preferably in a ratio of about 5 / 5. Additionally, the process gas may for example comprise in addition to carbon dioxide one or more of the following compounds: Nitrogen, argon, oxy- gen, hydrogen, CO, hydrocarbons, nitrogen oxides, sulfur, sulfur oxides or hydrocarbons comprising sulfur (as men-tioned above regarding the fresh process gas, without recycled part of the product gas).The high CO concentration in the process gas is typically a result of a possible recycling or recirculation of the prod-uct gas without first separating the CO from said product gas in combination with the removal of oxygen by means of the carbon particles, which inhibits the recombination of O2and CO to CO2. Step b) of the inventive method comprises: Contacting the plasma of said process gas comprising CO and O species with solid carbon, preferably in form of car- bon particles, whereby a gas mixture comprising CO and CO2is obtained.Step b) can for example be carried out by delivering carbon dioxide to an arc to form a plasma into which solid car-bon is delivered, as for example described in US 4190636 A.In this case, it is also possible that, one electrode may be made of solid carbon, which is consumed into the plasma,and which thus delivers some amounts of solid carbon into the plasma. The electrode may be made of the pyrolyticcarbon described in the present application. Additional amounts of solid carbon may be added to the plasma.However, it is preferred according to the present invention that solid carbon in form of carbon particles is added, in- dependent of the electrode material.Step b) can alternatively be carried out by introducing the plasma of the process gas comprising CO and O speciesinto a carbon reaction chamber comprising the solid carbon, preferably in form of carbon particles, thereby formingthe gas mixture comprising CO and CO2, as for example described in WO 2023 / 222708 A1.In any case, the solid carbon comprises pyrolytic carbon obtained by pyrolysis ofi) plastic waste, preferably end-of-life tires (ELT) waste, mixed plastic waste (MPW), automotive-shredder-resi-due (ASR), plastic solid waste (PSW), present in municipal solid waste (MSW), electronic waste (E-waste) ormixtures thereof;ii) at least one kind of hydrocarbons, preferably natural gas, methane, ethane, propane, butane, pentane or mix-tures thereof, more preferably natural gas or methane; oriii) mixtures of i) and ii),preferably obtained by pyrolysis ofi) plastic waste, preferably end-of-life tires (ELT) waste, mixed plastic waste (MPW), automotive-shredder-resi-due (ASR), plastic solid waste (PSW), present in municipal solid waste (MSW), electronic waste (E-waste) ormixtures thereof; oriii) mixtures of i) and at least one kind of hydrocarbons, preferably natural gas, methane, ethane, propane, bu-tane, pentane or mixtures thereof, more preferably natural gas or methane (ii)),as described in the present application.The method comprises converting the CO2 into CO using the reversible Boudouard reaction. The reversible Bou-douard reaction is used to convert CO2to CO based on the addition of carbon at high temperatures. Step b) is therefore carried out at temperatures of at least at 700°C, at least 750°C, more preferably at least 800°C, further more preferably at least 850°C, even further more preferably at least 900°C, most preferably at least 950°C,further most preferably at least 1000°C. The upper temperature limit is for example 5000°C, preferably 4000°C.Step b) is generally carried out at about atmospheric pressure. Atmospheric pressure refers to a pressure close to 1atm (1013.25 hPa), preferably from 500 to 5000 hPa, more preferably at least 900 hPa, still more preferably at least950 hPa, and / or more preferably at most 1100 hPa, still more preferably at most 1070 hPa, most preferably from 970 hPa to 1050 hPa, such as around 1013 hPa.In a preferred embodiment of the invention, the carbon donor particles are carbon particles in the form of a powder.Depending on the embodiment, the solid carbon, preferably in form of a powder, can be carried into the plasma by astream of the carbon dioxide comprising process gas. In this case it is preferred to introduce the solid carbon aheadof the arc, as for example described in US 4190636 A.In the case that step b) is carried out by introducing the plasma of the process gas comprising CO and O species into a carbon reaction chamber comprising the solid carbon, preferably in form of carbon particles, as for example de-scribed in WO 2023 / 222708 A1, the solid carbon can be preferably supplied through an additional inlet with a carriergas, such as air, or together with the main process gas supply.Preferably, the solid carbon, in form of carbon particles, is in a fluidized state. However, it is generally also possiblethat the solid carbon, in form of carbon particles, are positioned in a fixed bed, or a down flow of solid carbon, in formof carbon particles, is created, preferably under the influence of gravity, while the down flow of solid carbon, in formof carbon particles, is exposed to O radicals, preferably in counter-flow to the down flow.In step b), a gas mixture comprising carbon monoxide (CO) and carbon dioxide (CO2) is obtained. Step c) of the inventive method comprises: Quenching the gas mixture, whereby a product gas comprising CO and CO2 is obtained. Quenching of the gaseous products is essential to produce high yields of carbon monoxide, which is thermodynami- cally unstable but kinetically stable with respect to carbon and carbon dioxide at low temperatures. The quenching may be carried out by coolant water, and the heat may be recovered by heat exchangers. Quenching and heat exchanging are known in the art and for example described in US 4190636 A. The quenched products may be filtered to remove carbon therefrom. The carbon may be reused.A part of the product gas comprising carbon monoxide and carbon dioxide may be recycled to step a) of the inventivemethod. The part of the product gas can be recycled with previous separation of the carbon monoxide and carbon dioxide in aseparator, whereby only the separated carbon dioxide is recycled to step a), or without separation.In the case with separation, the recycled carbon dioxide is enriched with fresh process gas comprising carbon diox-ide to enter step a) of the inventive method.In the case without separation, the recycled product gas is enriched with fresh process gas comprising carbon diox-ide to enter step a) of the inventive method; and a second part of the product gas is extracted as extracted productgas comprising carbon dioxide and carbon monoxide and provided to a separation unit. In the separation unit, theextracted product gas is separated into a carbon monoxide gas stream and a carbon dioxide gas stream, which isrecycled in step a) of the inventive method. The present invention further relates to a process for preparing solid carbon, preferably in form of carbon particles, for converting CO2 to CO in a plasma process comprising the steps:A) pyrolyzingi) plastic waste, preferably end-of-life tires (ELT) waste, mixed plastic waste (MPW), automotive-shred-der-residue (ASR), plastic solid waste (PSW), present in municipal solid waste (MSW), electronic waste (E-waste) or mixtures thereof;ii) at least one kind of hydrocarbons, preferably methane, ethane, propane, butane, pentane or mixturesthereof, more preferably methane; or iii) mixtures of a) and b);whereby pyrolytic carbon in form of primary particles is obtained;B) optionally further processing the pyrolytic carbon in form of primary particles obtained in step a), preferably byone or more of the following processing steps: Graphitization, purification, activation, chemical modification,carbonization, densification or surface coating;C) optionally mixing the pyrolytic carbon obtained in step a) or optionally obtained in step b) with at least onebinder. Steps A) and B) of the inventive process are described above. The mixing step C) is generally carried out without heating, usually at ambient temperature and at ambient pressure,e.g. at 20°C to 25°C and pressure close to 1 atm (1013.25 hPa). Suitable mixing devices are known in the art.The binder is generally a material that holds the pyrolytic carbon which is preferably present in form of particles to- gether. Suitable binders are generally known in the art and for example polymer materials such as polyvinylidene fluoride, polytetrafluoroethylene, carboxymethyl cellulose, styrene-butadiene copolymer, polyvinyl alcohol, acryloni-trile-butadiene copolymer, carboxylic acid-modified (meth) acrylate copolymer, phenolic binders and mixtures thereof.The amount of binder is generally up to 35% by weight, preferably 0.1 to 30% by weight, more preferably 1 to 25% by weight, based on the total amount of the pyrolytic carbon (including the binder).In one embodiment no binder (i.e.0% by weight) is present in the solid carbon. I.e. in said embodiment, the processfor preparing solid carbon does not comprise step C).The present invention further relates to a reducing agent for a method for converting carbon dioxide (CO2) to carbonmonoxide (CO) by a plasma process comprising solid carbon, preferably in form of particles, comprising pyrolytic car-bon obtained by pyrolysis ofi) plastic waste, preferably end-of-life tires (ELT) waste, mixed plastic waste (MPW), automotive-shredder-resi-due (ASR), plastic solid waste (PSW), present in municipal solid waste (MSW), electronic waste (E-waste) ormixtures thereof;ii) at least one kind of hydrocarbons, preferably methane, ethane, propane, butane, pentane or mixtures thereof,more preferably methane; oriii) mixtures of i) and ii).The pyrolysis and the components mentioned under i), ii) and iii) as well as a method for converting carbon dioxide (CO2) to carbon monoxide (CO) by a plasma process comprising solid carbon are described above. Further, the present invention relates to the use of pyrolytic carbon obtained by pyrolysis ofi) plastic waste, preferably end-of-life tires (ELT) waste, mixed plastic waste (MPW), automotive-shredder-resi-due (ASR), plastic solid waste (PSW), present in municipal solid waste (MSW), electronic waste (E-waste) ormixtures thereof;ii) at least one kind of hydrocarbons, preferably methane, ethane, propane, butane, pentane or mixtures thereof,more preferably methane; oriii) mixtures of i) and ii);as reducing agent in a method for converting CO2 to CO by a plasma process.The pyrolysis and the components mentioned under i), ii) and iii) as well as a method for converting carbon dioxide (CO2) to carbon monoxide (CO) by a plasma process comprising solid carbon are described above.Further, the present invention relates to a method for converting CO2 to CO, comprising:contacting a process gas comprising CO2with solid carbon, preferably in form of carbon particles, at a temperature of ≥ 800°C, preferably 800 to 1700°C, whereby a gas mixture comprising CO and CO2is obtained, wherein the solid carbon comprises pyrolytic carbon obtained by pyrolysis of end-of-life tires (ELT) waste.The pyrolysis, the solid carbon and the end-of-life tires (ELT) waste are described above. Methods for converting car-bon dioxide (CO2) to carbon monoxide (CO) in the presence of carbon are for example described in US20150291433A1 and US6565824 B1. Preferably, the method additionally comprises a step: cooling the gas mixture comprising CO and CO2, whereby a product gas comprising CO and CO2 is obtained.During the cooling mentioned above, heat is generated. Preferably, at least a portion of said heat is used to preheatthe process gas comprising CO2 prior to the contacting with the solid carbon.In the method for converting CO2 to CO mentioned above, energy has to be introduced. Preferably, the energy is atleast in part, preferably fully, introduced by means of a plasma source, plasma source, whereby a plasma of said pro-cess gas comprising CO and O species is generated.A method for converting carbon dioxide (CO2) to carbon monoxide (CO) by a plasma process comprising solid car-bon is described above.Examples and comparative example The following four samples of solid carbon were investigated in a CO2-atmosphere at temperatures from 20 to 900 °C: CB = Carbon Black (comparative example) TPC = Tire Pyrolysis Char MPW85 = pyrolysis char from Mixed Plastic Waste with ~85% polyolefine content MPW60 = pyrolysis char from Mixed Plastic Waste with ~60% polyolefine content Mass loss of carbon and formation of CO, which indicates conversion of carbon to CO, was measured over time (0 – 300 minutes) in these experiments using thermogravimetric analysis coupled with FTIR spectroscopy: Thermal analysis was conducted using a simultaneous differential thermal analysis and thermogravimetric system (DTA-TG) NETZSCH STA 409 C / CD, coupled with a Bruker Tensor 27 FTIR spectrometer for evolved gas analysis.A sample mass of approx.30 mg was manually weighed and placed in a high purity α-Al₂O₃ crucible. The measure-ment was carried out in DTA-TG mode using a correction run with identical conditions. The furnace was equipped with a standard SiC heating element and S-type thermocouples for both furnace and sample temperature control. The temperature program consisted of a dynamic heating segment from 20 °C to 900 °C at a constant rate of 5 K / min, followed by a 2-hour isothermal hold at 900 °C. The total measurement duration was approximately 5 hours. The analysis was conducted under an inert argon atmosphere, with a flow rate of 70 mL / min and CO2 atmosphere, with a flow rate of 60 mL / min. The gas purity for both gases is consistent with standard evolved gas analysis proto- cols. Evolved gases were transferred from the thermogravimetric system to the FTIR spectrometer via a heated transfer line maintained at 200 °C to prevent condensation. The Bruker Tensor 27 FTIR spectrometer was equipped with a gas cell for continuous monitoring of volatile decomposition products. Spectra were recorded in the mid-infrared range (4000–600 cm⁻¹) with a resolution of 2 cm⁻¹ and a scan rate of 1 spectrum per minute. Thermogravimetric data revealed multiple mass loss events. These events were correlated with FTIR spectral fea- tures to identify characteristic functional groups and gaseous species released during thermal degradation. The resulting TG curves were corrected for potential mass loss due to air leakage into the system and the FTIR-sig-nal for CO was both integrated over its characteristic wavelength band of (2135 - 2040 cm-1) and the TG runtime.The following results were obtained: Table 1: Comparison of mass loss occurring due to reaction with CO2 in TG run with CO2 residual residual residual start tempera- mass af- mass af- mass af- ture for mass ter 150 ter 200 ter 290 sample loss min. in % min. in % min. in % CB 850 °C 99,2 92,1 73,4TPC 800 °C 98,8 80,6 63,6MPW85 700 °C 72,2 57,4 60,6MPW60 700 °C 72,1 44,8 47,0Table 2: Comparison of CO-formation occurring due to reaction with CO2 in TG run with CO2 sum of start tempera- CO; Inte- ture for mass gral sample loss (FTIR) TPC 800 °C 2085MPW85 700 °C 4482MPW60 700 °C 6906In Fig.1, the residual mass and temperature profile during TG run with CO2 of carbon black sample is shown.On the y-axis, the residual mass is displayed in wt.% and on the x-axis, the time is displayed in minutes. The symbols in Fig.1 have the following meanings:● Ash (residual mass in weight percent at 815°C, by TG in air)○ Ash + C-Fix (residual mass in weight percent at 900°C, by TG in Ar (Argon))---- T (Temperature)___ CO2 (residual mass in weight percent, by TG in CO2)In Fig.2, the residual masses and temperature profile during TG runs with CO2 and Ar of MPW60 sample is shown.On the y-axis, the residual mass is displayed in wt.% and on the x-axis, the time is displayed in minutes. The symbols in Fig.1 have the following meanings:● Ash (residual mass in weight percent at 815°C, by TG in air)○ Ash + C-Fix (residual mass in weight percent at 900°C, by TG in Ar (Argon))---- T (Temperature)___ CO2 (residual mass in weight percent, by TG in CO2)_______Ar (residual mass in weight percent, by TG in Ar)The results show that the Boudouard reaction between CO2 and all four samples takes place, as for all samples anadditional mass loss occurs (compared to TG in Ar atmosphere, as shown in example MPW60, Figure 2). Moreover,the formation of CO increases with increasing mass loss during reaction – as shown by the integral of the CO FTIRsignal (Table 2) and the corresponding mass losses (Table 1). It can be clearly seen that the Boudouard reaction is possible with pyrolysis char from tires (TPC sample) and MixedPlastic Waste (MPW samples) as solid carbon. Even more unexpectedly, the TPC- and MPW-samples are signifi-cantly more reactive than Carbon Black (CB), as can be seen by the early reaction on-set (onset-temperature ~50 to 150°C lower than for CB, cf. Table 1) and their higher mass loss over time (cf. Table 1).

Claims

Claims1. A method for converting CO2 to CO, comprising the steps of:a) exposing a process gas comprising CO2 to a plasma source, whereby a plasma of said process gascomprising CO and O species is generated;b) contacting the plasma of said process gas comprising CO and O species with solid carbon, preferablyin form of carbon particles, whereby a gas mixture comprising CO and CO2is obtained; c) and quenching the gas mixture, whereby a product gas comprising CO and CO2 is obtained;wherein the solid carbon comprises pyrolytic carbon obtained by pyrolysis of i) plastic waste, preferably end-of-life tires (ELT) waste, mixed plastic waste (MPW), automotive-shred-der-residue (ASR), plastic solid waste (PSW), present in municipal solid waste (MSW), electronic waste (E-waste) or mixtures thereof;ii) at least one kind of hydrocarbons, preferably natural gas, methane, ethane, propane, butane, pentaneor mixtures thereof, more preferably natural gas or methane; oriii) mixtures of i) and ii).

2. The method according to claim 1, wherein the pyrolytic carbon is obtained by pyrolysis in fixed, moving or fluid-ized bed reactors.

3. The method according to claim 1 or 2, wherein the pyrolytic carbon is obtained by pyrolysis ofi) plastic waste, preferably end-of-life tires (ELT) waste, mixed plastic waste (MPW), automotive-shred-der-residue (ASR), plastic solid waste (PSW), present in municipal solid waste (MSW), electronic waste (E-waste) or mixtures thereof; oriii) mixtures of i) and at least one kind of hydrocarbons, preferably natural gas, methane, ethane, propane,butane, pentane or mixtures thereof, more preferably natural gas or methane (ii)).

4. The method according to any one of claims 1 to 3, wherein the pyrolytic carbon comprises or consists of pyro-lytic carbon directly obtained from pyrolysis as primary particles in form of granular carbon, carbon black orcarbon powder.

5. The method according to claim 4, wherein the pyrolytic carbon directly obtained from pyrolysis as primary parti-cles has at least one of the following properties: -a BET surface area of 10 to 400 m2g-1, preferably 15 to 300 m2g-1, more preferably 40 to 150 m2g-1;- a carbon content of at least 80 wt%, preferably 85 wt% to 100 wt%, more preferably 86 wt% to 98 wt%;most preferably 90 wt% to 97 wt%; -a particle diameter D50 of at least 0.05 mm; preferably 0.05 mm to 4 mm, more preferably at least 0.5 mm,most preferably 0.5 mm to 4 mm;- a density of 1 to 3.5 g / cm3, preferably 1.8 to 2.2 g / cm3.

6. The method according to according to claim 4 or 5, wherein the pyrolytic carbon comprises or consists of pyro-lytic carbon, wherein the primary particles are further processed, preferably by one or more of the following processing steps: Graphitization, purification, activation, chemical modification, carbonization, densification orsurface coating.

7. The method according to any one of claims 1 to 6, wherein the solid carbon comprises in addition to the pyro-lytic carbon at least one binder.

8. The method according to any one of claims 1 to 7, wherein the plasma source is selected from the group con-sisting of a plasma jet generator, a plasma torch, a microwave plasma source, an induction plasma source, arc discharges, glow discharges, and dielectric barrier discharges, preferably a plasma jet generator or an arc dis- charge, more preferably a plasma jet generator.

9. The method according to any one of claims 1 to 8, wherein step b) is carried out byintroducing the plasma of the process gas comprising CO and O species into a carbon reaction chamber com-prising the solid carbon, preferably in form of carbon particles, thereby forming the gas mixture comprising CO and CO2.

10. The method according to any one of claims 1 to 9, wherein a part of the product gas, especially at least a partof the CO2 in the product gas, is recycled into the method according to any one of claims 1 to 9.

11. A process for preparing solid carbon, preferably in form of carbon particles, for converting CO2 to CO in aplasma process comprising the steps: A) pyrolyzingi) plastic waste, preferably end-of-life tires (ELT) waste, mixed plastic waste (MPW), automotive-shredder-residue (ASR), plastic solid waste (PSW), present in municipal solid waste (MSW), electronic waste (E-waste) or mixtures thereof;ii) at least one kind of hydrocarbons, preferably methane, ethane, propane, butane, pentane ormixtures thereof, more preferably methane; or iii) mixtures of i) and ii);whereby pyrolytic carbon in form of primary particles is obtained; B) optionally further processing the pyrolytic carbon in form of primary particles obtained in step A), pref-erably by one or more of the following processing steps: Graphitization, purification, activation, chemi-cal modification, carbonization, densification or surface coating;C) optionally mixing the pyrolytic carbon obtained in step A) or optionally obtained in step B) with at leastone binder.

12. The process according to claim 11, wherein the pyrolytic carbon is obtained by pyrolysis ofii) plastic waste, preferably end-of-life tires (ELT) waste, mixed plastic waste (MPW), automotive-shred-der-residue (ASR), plastic solid waste (PSW), present in municipal solid waste (MSW), electronic waste (E-waste) or mixtures thereof; oriii) mixtures of i) and at least one kind of hydrocarbons, preferably natural gas, methane, ethane, propane, bu-tane, pentane or mixtures thereof, more preferably natural gas or methane (ii)).

13. A reducing agent for a method for converting CO2 to CO by a plasma process comprising solid carbon, prefer-ably in form of particles, being pyrolytic carbon obtained by pyrolysis of i) plastic waste, preferably end-of-life tires (ELT) waste, mixed plastic waste (MPW), automotive-shred-der-residue (ASR), plastic solid waste (PSW), present in municipal solid waste (MSW), electronic waste (E-waste) or mixtures thereof;ii) at least one kind of hydrocarbons, preferably methane, ethane, propane, butane, pentane or mixturesthereof, more preferably methane; or iii) mixtures of i) and ii).

14. Use of pyrolytic carbon obtained by pyrolysis ofi) plastic waste, preferably end-of-life tires (ELT) waste, mixed plastic waste (MPW), automotive-shred-der-residue (ASR), plastic solid waste (PSW), present in municipal solid waste (MSW), electronic waste (E-waste) or mixtures thereof;ii) at least one kind of hydrocarbons, preferably methane, ethane, propane, butane, pentane or mixturesthereof, more preferably methane; or iii) mixtures of i) and ii);as reducing agent in a method for converting CO2 to CO by a plasma process.

15. A method for converting CO2 to CO, comprising:contacting a process gas comprising CO2 with solid carbon, preferably in form of carbon particles, at a tem- perature of ≥ 800°C, preferably 800 to 1700°C, whereby a gas mixture comprising CO and CO2 is obtained, wherein the solid carbon comprises pyrolytic carbon obtained by pyrolysis of end-of-life tires (ELT) waste.

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