New method for producing carbon (nano) structures from pyrolysis oil

Abstract

The present invention relates to a method for producing a crystalline carbon nanofiber network from a pyrolysis oil in a furnace black reactor 3 equipped with a reaction zone 3b and a termination zone 3c, in which a thermodynamically stable pyrolysis oil-containing microemulsion c containing metal catalyst nanoparticles is injected into the reaction zone 3b, which is at a temperature above 600°C, preferably above 700°C, more preferably above 900°C, even more preferably above 1000°C, more preferably above 1100°C, preferably at most 3000°C, more preferably at most 2500°C, and most preferably at most 2000°C, to produce crystalline carbon structure networks e, which are then transferred to the termination zone 3c, in which the formation of the crystalline carbon structure networks is quenched or terminated by spraying water d.

Description

Technical Field

[0001] The present invention relates to the field of porous chemically interconnected carbon nanofiber-containing carbon networks from sustainable resources, and aims at a new method for manufacturing such sustainable structural networks and composites containing such sustainable structures. The present invention relates in particular to the field of carbon black production.

Background Art

[0002] The carbon black industry focuses on providing mainly graphite and amorphous carbon and allotropes of carbon with different physical arrangements thereof for use in the manufacture of rubber articles (e.g., tires), polygraphy, electronic devices and cable coatings, varnishes and paints, including applications where the reinforcing and / or pigment properties of carbon black are required. Various different methods or techniques for manufacturing carbon black are known in the art. Carbon black is mainly produced by the partial combustion method starting from carbon-containing gases such as methane or acetylene. This method is sometimes referred to as the furnace carbon black production method, which utilizes a reactor following a furnace with burners or a combustion chamber. The furnace method is usually characterized by a small amount of oxygen, low density, high temperature and short residence time.

[0003] As a first step in the process for manufacturing furnace carbon black, as described in Ullmanns Encyklopadie der technischen Chemie, Volume 14, page 637-640 (1977), hydrocarbons are usually atomized at 1200 to 1900 °C. For this purpose, a zone having a high energy density is generated by burning a fuel gas or liquid fuel with oxygen or air, and a carbon black raw material is injected thereinto. The carbon black raw material is atomized under these high-temperature combustion conditions; the amount of oxygen is supplied, on average, at a ratio of about 1 volume of oxygen to 2 volumes of carbon black raw material in order to achieve complete consumption of the oxygen in the combustion process. The structure and / or porosity of the final carbon black product may be affected by the presence of alkali metal or alkaline earth metal ions during carbon black formation, and thus such additives are often added in the form of an aqueous solution that is sprayed onto the carbon black raw material agglomerates. The reaction is terminated (quenched) by injection of water only, and the carbon black is recovered at about 200 to 250 °C and separated from the waste gas using a conventional separator or filter. Due to its low bulk density, the obtained carbon black is then granulated, for example, in a granulator with addition of water, to which a small amount of granulation aid may also be added.

[0004] In chronological order, without in any way limiting the technical fields related to furnace carbon black technology, U.S. Patent Nos. 2,672,402, 4,292,291, 4,636,375, International Publication No. 2000 / 032701 and U.S. Patent Application Publication No. 2004 / 0248731 describe traditional or conventional carbon black production. These are incorporated herein by reference. Regarding carbon black raw materials, approximately 17.5 million tons of carbon black per year are produced worldwide using anthracene oil, coal tar oil and FCC slurry or pitch from steam crackers as the main raw materials for manufacturing carbon black. Assuming a 50% conversion rate, this would require supplying 35 million tons of crude oil / coal-derived raw materials to the market each year. By replacing these raw materials with sustainable raw material sources, potentially 150 million tons of CO 2 emissions can be reduced.

[0005] U.S. Patent Application Publication No. 2011 / 0200518 describes a method for producing pyrolytic carbon black (pCB) from rubber composites, such as tire rubber. However, pyrolysis is applied to the tire to produce char that ultimately leads to carbon black; the pyrolysis oil is not used as a carbon black raw material. Okoye et al., Journal of Cleaner Production, 2020 (https: / / doi.org / 10.1016 / j.jclepro.2020.123336) outlines and discloses that tire pyrolysis oil can be used as a potential raw material for carbon black (Item 6, Spent tyre pyrolysis oil as a potential feedstock for carbon black). However, the evaluation is based on laboratory-scale experiments, and thus, the issues arising from its industrial-scale application, such as the yield and grade of the produced carbon black and the detailed planning of operations with pyrolysis oil, have not been evaluated. For example, this literature refers to the laboratory studies of Wojtowicz et al., Advanced Fuel Research, Inc, 2004, which shows that carbon black can be obtained using the oil fraction of the spent tire pyrolysis process in a furnace reactor operated at 1100 °C for residence times of 5 and 20 seconds; and Toth et al., Green Chemistry, 2018, 20, 3981 - 3992 (https: / / doi.org / 10.1039 / c8gc01539b), which reports the production of CB from a furnace reactor using pyrolysis bio-oil from a mixture of dry wood chips in a simulated furnace reactor operated at 1100 - 1700 °C with a residence time of around 30 seconds. Still, Okoye concludes that there are currently no studies examining the absorption or structural properties of carbon black from pyrolysis oil (Item 6, last line). This, combined with the fact that there is currently no commercial method for utilizing pyrolysis oil for carbon black production, demonstrates the lack of knowledge regarding carbon black production based on pyrolysis oil.

[0006] WO 2013 / 170358 describes the production of carbon black with a very low polycyclic aromatic hydrocarbon (PAH) content from pyrolysis oil in a furnace reactor. However, this document generally claims, without providing specific methods or product data for practicing the present invention, that N-series carbon black can be produced from oil derived from waste tire pyrolysis. In fact, using the described method to produce carbon black from pyrolysis oil is generally recognized in the industry as being too low in yield and leading to low quality to be commercially viable, especially with regard to obtaining the same range of grades that can be produced using ordinary carbon black raw materials. Derived from carbon black-based manufacturing, WO 2018 / 002137 describes a method for producing a crystalline carbon structure network using a carbon source in the form of a thermodynamically stable microemulsion containing metal catalyst nanoparticles in a furnace black reactor. WO 2019 / 224396 relates to the use of a porous chemically interconnected carbon nanofiber-containing carbon network for reinforcing elastomers, which are used in many technical fields such as tires, conveyor belts, hoses, etc. Regarding the carbon source, pyrolysis oil is not specifically mentioned.

[0007] EP 3486212 A1 describes a method for producing crystalline carbon nanostructures and / or networks of crystalline carbon nanostructures using different techniques. This involves contacting a bicontinuous microemulsion containing metal nanoparticles with a substrate, where the metal nanoparticles and a gaseous carbon source are subjected to chemical vapor deposition.

[0008] Pyrolysis oil is a liquid blend of molecules derived from different sources, such as end-of-life tires, waste plastics, or biomass. The exact composition of pyrolysis oil depends greatly on both the source and the processing conditions. The large compositional variations between batches and the need for several upgrading steps to obtain high-quality oil (Zhang et al., Energy Conversion and Management, 2007, 48, 87-92 and Miandad et al., Process Safety and Environmental Protection, 2016, 102, 822-838) limit the commercial use of pyrolysis oil to heat and power generation. Depending on the source and processing conditions, there are significant variations in the amounts of sulfur and water. The same is true for the aromatic content, and these variations hinder the setting of industrially controllable carbon black production for pyrolysis oil from carbon feedstock sources.

[0009] There remains a direct need to update traditional carbon black manufacturing methods from a sustainability perspective, where sustainability is understood as striving to improve the efficiency of natural resource use in order to meet human needs for chemical products and services through the design, manufacture, and use of efficient, effective, safe, and more environmentally friendly chemical products and manufacturing methods (OECD definition). The pyrolysis purification process is not an attractive candidate for making carbon black production more sustainable; rather, it adds cost to the manufacturing process. Therefore, the direct use of pyrolysis oil in commercial methods for carbon black production represents the achievement of sustainability. SUMMARY OF THE INVENTION

[0010] The inventors have introduced the concept of single-phase emulsification using a thermodynamically stable microemulsion of the w / o type, o / w type or bicontinuous type, preferably the w / o type or bicontinuous type, most preferably the bicontinuous type, containing metal catalyst nanoparticles and an oil phase containing or consisting of pyrolysis oil, into the conventional (furnace) carbon black production. By using a well-established reduction (pyrolysis) or oxidation (combustion) carbon black production method, it has been found that pyrolysis oil can be converted into a novel carbon filler composed of a network of porous chemically interconnected carbon nanofiber-containing carbon structures having various advantageous improved electrical, mechanical and thermal properties. The advantages associated with single-phase emulsification applied in the present invention lie not only in using abundantly available and economically attractive raw materials without the need for large-scale processing, but also in enabling the production of carbon black materials from recycled oil from the pyrolysis process, making it sustainable (circular), which can be commercialized as a product as sustainable as its technical characteristics. It has also been found that a carbon network with improved wettability characteristics can be obtained by this method.

[0011] Accordingly, the present invention relates to a method for preparing a thermodynamically stable single-phase emulsion containing pyrolysis oil, water and at least one surfactant, and further metal catalyst nanoparticles, and subjecting the emulsified pyrolysis oil to a carbon black production method, carbonizing the emulsified pyrolysis oil at a high temperature of more than 600 °C, preferably more than 700 °C, more preferably more than 900 °C, even more preferably more than 1000 °C, most preferably more than 1100 °C, preferably 3000 °C or less, more preferably 2500 °C or less, particularly 2000 °C or less, to produce a network of porous chemically interconnected carbon nanofiber-containing carbon structures.

[0012] The above method is an industrial method, characterized in that the reactor residence time of the single-phase emulsion (and thus the pyrolysis oil supplied in emulsion form in this step) is less than 5 seconds, preferably less than 2 seconds, more preferably 1 to 1000 milliseconds, most preferably 10 to 500 milliseconds.

[0013] In a related aspect, the present invention relates to the use of such a single-phase emulsion of pyrolysis oil for carbonizing the emulsion in a carbon black production process, preferably a furnace carbon black production process, thereby obtaining a sustainable porous chemically interconnected carbon nanofiber-containing carbon structure network. The emulsion is preferably sprayed and atomized into the reactor at the high temperature described above.

[0014] In a preferred embodiment, the pyrolysis oil is the dominant carbon source in the above process, preferably accounting for at least 50%, more preferably 75 - 100% of all the carbon sources supplied in this process. In the most preferred embodiment, the pyrolysis oil is the sole carbon source.

[0015] The term "pyrolysis oil" is understood to be any oil directly derived from different streams from chemical processes, such as the pyrolysis of biomass (e.g., wood, algae, rice, nut shells), end-of-life tires or non-recyclable plastics, and provided to the process of the present invention without prior processing. Pyrolysis oil does not refer to the char obtained from the pyrolysis of these raw materials. The sulfur content of the pyrolysis oil usually varies from 0.002% to 3% (according to ASTM D1619), the water content is usually 1 - 40 wt%, the oxygen content is 0.2% - 50 wt%, and the carbon content is preferably at least 40 wt%. The aromaticity of the carbon source is irrelevant; the method of the present invention functions with any of aliphatic, aromatic or a combination of the two types of carbon. Considering the above, the pyrolysis oil supplied to this process is unpurified, i.e., not pre-purified.

[0016] Throughout this specification and the claims, "single-phase emulsion" is a thermodynamically stable water-in-oil (w / o) or oil-in-water (o / w) microemulsion or bicontinuous microemulsion containing metal catalyst nanoparticles. The bicontinuous microemulsion containing metal catalyst nanoparticles is most preferred.

[0017] The inventors recognized that there is a preconception regarding the use of pyrolysis oil as a carbon black raw material on a commercial scale. In the eyes of those skilled in the art, (unrefined) pyrolysis oil is considered not to be a suitable raw material for carbon black production for several reasons. First, in traditional carbon black production methods, the use of water should be at least minimized and preferably prohibited in the reaction zone in order to obtain an appropriate yield and a preferred spherical carbon black structure. As a result, during traditional carbon black production, it has become widespread to refrain from using water except for quenching purposes in the final stage. Similarly, some pyrolysis oils may contain an excessive amount of sulfur or oxygen atoms to ensure the formation of an appropriate carbon black structure, while other pyrolysis oils do not contain sufficient precursors (aromatic content) to form a significant amount of carbon black in an industrial-scale reactor due to the short residence time of an industrial furnace black reactor that does not provide enough time to form graphite layers from non-ideal precursors. Due to the combination of high water content, low aromaticity, high oxygen content and / or high sulfur content, as well as the need for a long residence time, the use of (unrefined) pyrolysis oil for the production of carbon black in a furnace reactor (which requires a short residence time to produce a carbon structure of appropriate quality) is not suitable on an industrial scale, and this has deterred those skilled in the art from switching to this sustainable raw material.

[0018] The inventors found that by changing conventional carbon black production by atomizing a stable single-phase emulsion containing metal catalyst particles, it becomes possible to handle pyrolysis oil without the need for a prior purification step. The inventors believe that the orientation and structuring of surfactant molecules, pyrolysis oil phase and aqueous phase with metal catalyst nanoparticles give rise to a network formation method specific to the new materials and production methods. The inventors found that it is important to provide the pyrolysis oil in the form of the above single-phase emulsion during the atomization process.

[0019] The metal catalyst nanoparticles are essential for the present invention. The atomized and then carbonized single-phase emulsion should contain metal nanoparticles that act as catalysts in the formation of these porous chemically interconnected carbon nanofiber-containing carbon networks. An increase in the concentration of the metal catalyst nanoparticles further improves the yield. It is essential to use either a bicontinuous or water-in-oil (w / o) microemulsion where the emulsion contains the metal catalyst nanoparticles and the emulsion contains a continuous oil / surfactant phase and thus already forms a network structure, or an oil-in-water (o / w) microemulsion where the emulsion contains the metal catalyst nanoparticles. The bicontinuous microemulsion is most preferred. The microstructure of the emulsion (either water-in-oil type, oil-in-water type, or bicontinuous) is thought to act as a precursor / prototype of the final carbon structure network, in which the carbon-containing fractions (pyrolytic oil phase and surfactant) form fibers and junctions, while the water fraction serves to orient the pyrolytic oil / surfactant phase and network porosity. The presence of the metal catalyst promotes the carbonization of the carbon component into a fiber structure instead of the usually obtained spherical orientation. A blend of immiscible pyrolytic oil and water phases does not result in these structures, i.e., there is no metal catalyst in a thermodynamically stable matrix. When the emulsion is atomized at a high temperature, the carbonization process causes the carbon fraction in the emulsion structure to "solidify" immediately in the presence of the metal catalyst, while the water evaporates, leaving behind a network of (nano)fibers.

[0020] Using the aforementioned emulsion containing the active ingredient and thus driving the manufacturing process by catalysis (kinetics) rather than thermodynamics, the inventors were able to produce graphite layers on a millisecond time scale, thereby enabling the manufacturing process to be carried out on an industrial furnace black reactor scale. This is based on the inventors' understanding of carbon black formation based on a narrow crystallite size and particle size distribution, a one-way crystallite alignment, or filament formation. Furthermore, the catalyst enables the conversion of different raw materials (aromatic and aliphatic) and thus enables the use of pyrolytic oil for the production of carbon black products with appropriate technical properties.

[0021] The pyrolysis oil can be obtained from several waste streams, such as biomass (wood, algae, rice, nut shells, etc.), end-of-life tires or non-recyclable plastics. Therefore, the method for manufacturing the carbon filler according to the present invention can be considered a recycling method, and even more an upcycling, for two reasons. First, considering that the pyrolysis oil is a lower-grade product, using it to produce a higher-grade carbon filler brings much value to the source. Second, due to the significant improvement in the properties that the carbon filler brings to the polymer, such as mechanical strengthening, electrical conductivity (target for ESD or EMI shielding range) and control of thermal conductivity, the properties of these recycled polymers (usually with low properties) combined with the carbon filler of the present invention can be equivalent to or better than the properties of virgin polymers and / or virgin polymers containing carbon fillers made from raw materials derived from crude oil.

[0022] Furthermore, due to the present invention, the method for manufacturing the carbon filler becomes circular by upcycling the waste stream, increasing the sustainability of the method and further increasing the sustainability of the products obtained by the method. For example, considering tires as a source of pyrolysis oil, this means that tires containing carbon fillers are used as a source for manufacturing the same carbon fillers, thus reducing the carbon footprint of the final product. Furthermore, this carbon filler can be manufactured cyclically on an industrial scale and becomes the first upcycled carbon filler made from waste streams on a commercial scale. The application fields of this circular carbon filler are diverse: rubber (tires and technical rubber products), thermoplastics, 3D printing, thermosetting resins, coatings and inks, battery electrodes, energy storage materials or water purification membranes. Therefore, the present invention also relates to the use of a sustainable porous chemically interconnected carbon nanofiber-containing carbon network in increasing the sustainability of, in particular, rubber (tires and technical rubber products), thermoplastics, 3D printing, thermosetting resins, coatings and inks, battery electrodes, energy storage materials or water purification membranes.

Brief Description of the Drawings

[0023]

FIG. 1A

[0024] Claims 1. A method for producing a crystalline carbon nanofiber network from pyrolysis oil in a reactor 3 equipped with a reaction zone 3b and a quenching zone 3c, comprising injecting a single-phase emulsion c, which is a microemulsion containing the pyrolysis oil and metal catalyst nanoparticles according to the present invention, into the reaction zone 3b at a temperature above 600 °C, preferably above 700 °C, more preferably above 900 °C, even more preferably above 1000 °C, more preferably above 1100 °C, preferably below 3000 °C, more preferably below 2500 °C, and most preferably below 2000 °C to produce a crystalline carbon structure network e, transferring these networks e to the quenching zone 3c, and quenching or stopping the formation of the crystalline carbon structure network by spraying water d in the quenching zone. 2. The reactor is a furnace carbon black reactor 3 having a combustion zone 3a, a reaction zone 3b, and a quenching zone 3c along the axis of reactor 3. Fuel a is burned in an oxygen-containing gas b, and waste gas a1 is moved from the combustion zone 3a to the reaction zone 3b to generate a flow of hot waste gas a1 in the combustion zone. A microemulsion c containing pyrolysis oil and metal catalyst nanoparticles is sprayed into the reaction zone 3b containing the hot waste gas. The microemulsion is carbonized at a temperature above 600 °C, preferably above 700 °C, more preferably above 900 °C, even more preferably above 1000 °C, more preferably above 1100 °C, preferably 3000 °C or lower, more preferably 2500 °C or lower, and most preferably 2000 °C or lower. The reaction is quenched or stopped by spraying water d in the quenching zone 3c to obtain a crystalline carbon structure network e. The method according to clause 1. 3. The pyrolysis oil phase in the emulsion has a carbon content of at least 40% by weight, an added water content of 50% by weight or less, a sulfur content of 4% by weight or less, and an oxygen content of 50% by weight or less based on the total weight of the pyrolysis oil. The method according to any one of the preceding clauses. 4. The emulsion contains at least 1 mM of metal catalyst nanoparticles with an average particle size preferably of 1 to 100 nm. The method according to any one of the preceding clauses. 5. At least 50% by weight, preferably all, of the carbon raw material of the network is provided as pyrolysis oil in a single-phase emulsion. The method according to any one of the preceding clauses. 6. The reactor residence time of the pyrolysis oil in the single-phase emulsion c is less than 5 seconds, preferably less than 2 seconds, more preferably 1 to 1000 milliseconds, and most preferably 10 to 500 milliseconds. The method according to any one of the preceding clauses. 7. The sulfur content of the pyrolysis oil supplied to the reactor 3 is 0.5 to 4.0% by weight based on the weight of the pyrolysis oil. The method according to any one of the preceding clauses. 8. The oxygen content of the pyrolysis oil supplied to the reactor 3 is 10 to 50% by weight based on the weight of the pyrolysis oil. The method according to any one of the preceding clauses. 9. A sustainable porous carbon network material comprising chemically interconnected carbon nanofibers that can be obtained by the method described in any one of the preceding clauses, wherein the intra-particle pore diameter of the pores in the network is 5 to 150 nm as determined by mercury intrusion porosimetry according to ASTM D4404-10, at least 20% by weight of the carbon in the carbon network is in crystalline form, the average aspect ratio of the fiber length to thickness of the carbon nanofibers is at least 2, the pH of the resulting carbon network is at most 8.5, preferably 4 to 8.5, most preferably 5.5 to 7.5, and the carbon is provided by pyrolysis oil. A sustainable porous carbon network material. 10. Use of emulsified pyrolysis oil in a carbon black production process, preferably a furnace carbon black production process, for producing a sustainable crystalline carbon structure network. 11. A sustainable product comprising the sustainable porous carbon network described in clause 9.

Embodiments for Carrying out the Invention

[0025] Detailed Description The present invention relates to a sustainable porous chemically interconnected carbon nanofiber-containing carbon network, which can preferably be obtained by a method for producing a porous chemically interconnected carbon nanofiber-containing carbon network. In a reactor 3, preferably a furnace black reactor, having a reaction zone 3b and a quenching zone 3c, an oil-in-water type, water-in-oil type or bicontinuous microemulsion c containing metal catalyst nanoparticles and pyrolysis oil is injected into the reaction zone 3b at a temperature above 600°C, preferably above 700°C, more preferably above 900°C, even more preferably above 1000°C, still more preferably above 1100°C, preferably below 3000°C, more preferably below 2500°C, and most preferably below 2000°C to produce a sustainable porous chemically interconnected carbon nanofiber-containing carbon network e. These networks e are transferred to the quenching zone 3c, and water d is sprayed in the quenching zone to quench or stop the formation of the porous chemically interconnected carbon nanofiber-containing carbon network.

[0026] In a more preferred embodiment, the network is such that the reactor is a furnace carbon black reactor 3 having a combustion zone 3a, a reaction zone 3b and a quenching zone 3c along the axis of the reactor 3. Fuel a is burned in an oxygen-containing gas b to generate a flow of hot waste gas a1 in the combustion zone, and the hot waste gas is transferred from the combustion zone 3a to the reaction zone 3b. An oil-in-water type, water-in-oil type or bicontinuous microemulsion c containing metal catalyst nanoparticles and pyrolysis oil is sprayed into the reaction zone 3b containing the hot waste gas. The emulsion is carbonized at a temperature above 600°C, preferably above 700°C, more preferably above 900°C, even more preferably above 1000°C, still more preferably above 1100°C, preferably below 3000°C, more preferably below 2500°C, and most preferably below 2000°C. The reaction is quenched or stopped by spraying water d in the quenching zone 3c to obtain a porous chemically interconnected carbon nanofiber-containing carbon network e, which can be obtained by the above method.

[0027] The above method is an industrial method. The typical production rate of an industrial reactor is a sustainable porous chemically interconnected carbon nanofiber-containing carbon network of 1 to 5 tons per hour. The typical residence time in reactor 3 is 1 to 1000 milliseconds.

[0028] The network can preferably be obtained by the above method, and further processing details are shown in the section "Method for Obtaining a Carbon Nanofiber-Containing Carbon Network" and the drawings below.

[0029] Throughout this specification and the claims, the terms "carbon structure network", "carbon network", "carbon nanofiber-containing carbon network" and "carbon nanofiber network" are used in the same meaning. Details of the network formed from carbon nanofibers and details of the manufacture are shown below.

[0030] Method for obtaining a carbon nanofiber-containing carbon network The method for obtaining a sustainable porous chemically interconnected carbon nanofiber-containing carbon network can best be described as a modified carbon black production method, where the pyrolysis oil is provided to the reaction zone of a carbon black reactor as part of a single-phase emulsion that is a thermodynamically stable microemulsion containing metal catalyst nanoparticles. Preferably, the emulsion is provided to the reaction zone by spraying, thus atomizing the emulsion into droplets. The method for producing modified carbon black is advantageously carried out as a continuous process.

[0031] On one side, the present invention relates to a method for producing a carbon structure network from pyrolysis oil, in a reactor 3 comprising a reaction zone 3b and a quenching zone 3c, by injecting a single-phase emulsion c, which is a microemulsion containing pyrolysis oil according to the present invention and metal catalyst nanoparticles, into the reaction zone 3b at a temperature above 600 °C, preferably above 700 °C, more preferably above 900 °C, even more preferably above 1000 °C, more preferably above 1100 °C, preferably below 3000 °C, more preferably below 2500 °C, most preferably below 2000 °C to produce a porous chemically interconnected carbon nanofiber-containing carbon network e, transferring these networks e to the quenching zone 3c, and quenching or stopping the formation of the porous chemically interconnected carbon nanofiber-containing carbon network by spraying water d in the quenching zone. The single-phase emulsion is preferably sprayed into the reaction zone. See Figure 1.

[0032] In a preferred embodiment, the present invention provides a method for producing a porous chemically interconnected carbon nanofiber-containing carbon network according to the present invention in a furnace carbon black reactor 3 having a combustion zone 3a, a reaction zone 3b, and a quenching zone 3c along the axis of the reactor 3. Fuel a is burned in an oxygen-containing gas b, and waste gas a1 is transferred from the combustion zone 3a to the reaction zone 3b to generate a flow of hot waste gas a1 in the combustion zone. In the reaction zone 3b containing the hot waste gas, a single-phase emulsion c containing pyrolysis oil and metal catalyst nanoparticles according to the present invention, preferably a microemulsion containing pyrolysis oil and metal catalyst nanoparticles, is sprayed (atomized). The emulsion is carbonized at a high temperature (above 600 °C, preferably above 700 °C, more preferably above 900 °C, even more preferably above 1000 °C, more preferably above 1100 °C, preferably below 3000 °C, more preferably below 2500 °C, most preferably below 2000 °C). By spraying water d in the quenching zone 3c, the reaction (i.e., the formation of a porous chemically interconnected carbon nanofiber-containing carbon network e) is quenched or stopped. The reaction zone 3b preferably includes at least one inlet (preferably a nozzle) for introducing the emulsion by atomization. Refer to Figure 1. The residence time of the emulsion in the reaction zone of the furnace carbon black reactor is relatively short, preferably 1 to 1000 milliseconds, more preferably 10 to 500 milliseconds. A long residence time may affect the properties of the carbon network. For example, a long residence time may increase the size of the crystallites.

[0033] The pyrolysis oil phase may be aromatic and / or aliphatic. The single-phase emulsion containing metal catalyst nanoparticles enables those skilled in the art to use various pyrolysis sources without a purification process. Preferred examples are oils obtained from the pyrolysis of biomass, plastics, or end-of-life tires. The carbon content of this pyrolysis oil should be at least 40% by weight, the water content may be 1 to 40% by weight, the sulfur content is 4% by weight or less, and the oxygen content is 0.2 to 50%. In one embodiment, the oxygen content is preferably 10 to 50%.

[0034] In conventional carbon black processing, sulfur has an adverse effect on the product quality, leading to low yields and corrosion of equipment. Therefore, it is preferable that the sulfur content of the pyrolysis oil is low. The sulfur content of the pyrolysis oil according to ASTM D1619 is less than 8.0% by weight, preferably less than 4.0% by weight, and more preferably less than 2.0% by weight. In one aspect, the sulfur content of the pyrolysis oil according to ASTM D1619 is 0.5 - 8% by weight, preferably 0.5 - 4.0% by weight; in the method of the present invention, it is not necessary to handle the amount of sulfur relative to the amount of purified pyrolysis oil less than 0.002% by weight.

[0035] The raw materials used to produce the inventors' network, which is a porous chemically interconnected carbon nanofiber-containing carbon network, are provided in the form of the oil component in an emulsion containing at least pyrolysis oil, surfactant, and water. The oil content of the emulsion is at least 50% by weight, the added water may be 1 - 50% by weight, and the surfactant content varies depending on the oil and water contents. In a preferred embodiment, all carbon raw materials are provided by one or more pyrolysis oils from one or various pyrolysis oil sources. In other words, the oil in the emulsion preferably consists of pyrolysis oil. The water content of the pyrolysis oil is also a parameter to be considered when formulating the emulsion. This emulsion is a single-phase emulsion in the sense that physical separation cannot be seen with the naked eye. When examined under a microscope, the separated oil and water phases can be distinguished. More precisely, an oil-in-water type, water-in-oil type, or bicontinuous microemulsion is observed. The emulsion is thermodynamically stable, that is, no external force is required to maintain it constant for at least 1 minute. Preferably, the pH of the water phase is maintained within the frame of ±1 pH unit, and the viscosity of the emulsion shows variation only within the frame of ±20%.

[0036] The aqueous phase of the emulsion contains an active ingredient, which has a catalytic function during the formation of a porous chemically interconnected carbon nanofiber-containing carbon network. The active ingredient is composed of metal particles or metal complexes having a size of 1 to 100 nm. The metal may be a noble metal (such as Au, Ag, Pd, Pt), a transition metal (such as Fe, Ru), or other metals, such as Ti or Cu. Suitable metal complexes include, but are not limited to, platinum precursors, such as H 2 PtCl 6 ; ruthenium precursors, such as Ru(NO)(NO 3 ) 3 ; or (iii) palladium precursors, such as Pd(NO 3 ) 2 , or nickel precursors, such as NiCl 2 . The concentration of the active metal in the aqueous phase should be greater than 1 mM.

[0037] The pyrolysis oil emulsion is a "single-phase emulsion", which is understood to mean that the pyrolysis oil phase and the aqueous phase optically appear as one miscible mixture that does not show physical separation of the pyrolysis oil, water, or surfactant to the naked eye. The single-phase emulsion is a microemulsion. The process by which the emulsion completely breaks down (coalesces), i.e., the system separates into the bulk oil and aqueous phases, is generally thought to be controlled by four different droplet loss mechanisms, namely Brownian aggregation, creaming, flocculation sedimentation, and disproportionation.

[0038] As long as a stable single-phase emulsion can be obtained, the amounts of added water and pyrolysis oil are considered not to be limited, but it should be noted that the yield is improved by reducing the amount of water (and increasing the amount of pyrolysis oil). The added water content (i.e., excluding the water content of the pyrolysis oil) is usually 5 to 50% by weight of the emulsion, preferably 10 to 40% by weight, more preferably 30% by weight or less, and more preferably 10 to 20% by weight of the emulsion. The amount of added water should take into account how much water has already been provided together with the pyrolysis oil. Larger amounts of water are conceivable, but the yield is sacrificed. Without wishing to be bound by theory, the inventors believe that the aqueous phase contributes to the shape and morphology of the network thus obtained.

[0039] Based on the weight of the emulsion provided in step a), usually 5 to 30 wt%, preferably 10 to 20 wt% of a surfactant is present. The surfactant may be a non-ionic surfactant having a hydrophilic-lipophilic balance (HLB) value of at least 7, preferably an HLB value of 10. Ionic surfactants that stabilize water-in-oil mixtures, such as (but not limited to) sodium dioctyl sulfosuccinate (AOT), can also be used. The choice of surfactant is not considered a limiting factor as long as the combination of pyrolysis oil, water and surfactant results in a stable microemulsion as described above. As a further guide to those skilled in the art, the surfactant can be selected based on the hydrophobicity or hydrophilicity of the system, i.e., the hydrophilic-lipophilic balance (HLB). The HLB of a surfactant is a measure of hydrophilicity or lipophilicity and is determined by calculating the values of different regions of the molecule according to the Griffin or Davies method. The appropriate HLB value depends on the type of pyrolysis oil and the amounts of pyrolysis oil and water in the emulsion, and those skilled in the art can easily determine it based on the requirement to maintain a thermodynamically stable single-phase emulsion as described above. Emulsions containing more than 50 wt% of pyrolysis oil and preferably having a water phase of less than 30 wt% are considered to be best stabilized with surfactants having an HLB value greater than 7, preferably greater than 8, more preferably greater than 9, most preferably greater than 10. On the other hand, emulsions containing up to 50 wt% of pyrolysis oil are considered to be best stabilized with surfactants having an HLB value of less than 12, preferably less than 11, more preferably less than 10, most preferably less than 9, especially less than 8.

[0040] The surfactant is preferably selected to be compatible with the pyrolysis oil phase. When the pyrolysis oil has a high BMCI, surfactants with high aromaticity are preferred, while pyrolysis oils with low BMCI, e.g., those characterized by a BMCI of less than 15, are thought to be best stabilized using aliphatic surfactants. The surfactant may be cationic, anionic or non-ionic or a mixture thereof. Since no ions remain in the final product, one or more non-ionic surfactants are preferred to increase the yield. To obtain a clean tail gas stream, the surfactant preferably has low sulfur and nitrogen and is preferably sulfur- and nitrogen-free. Non-limiting examples of representative non-ionic surfactants that can be used to obtain a stable emulsion are commercially available Tween®, Span®, Hypermer®, Pluronic®, Emulan, Neodol®, Triton® X and Tergitol®.

[0041] In the present invention, the microemulsion is a dispersant composed of water, pyrolysis oil and a surfactant, which is a single optically isotropic and thermodynamically stable liquid with a dispersed domain diameter varying from approximately 1 to 500 nm, preferably 1 to 100 nm, and typically 10 to 50 nm. In the microemulsion, the domains of the dispersed phase are either spherical (i.e., droplets) or interconnected (resulting in a bicontinuous microemulsion). In a preferred embodiment, the surfactant forms a continuous network in the oil phase of the water-in-oil (w / o) type or oil-in-water type emulsion or bicontinuous microemulsion. The water domains contain a metal catalyst with an average particle size preferably of 1 nm to 100 nm.

[0042] The single-phase emulsion, i.e., the w / o type, o / w type, or bicontinuous microemulsion, preferably the bicontinuous microemulsion, further contains metal catalyst nanoparticles with an average particle size preferably of 1 to 100 nm. Those skilled in the art can find various guides for manufacturing and using such nanoparticles in the field of carbon nanotubes (CNT). These metal nanoparticles are found to improve the formation and reproducibility of the network with respect to both speed and yield. Methods for manufacturing suitable metal nanoparticles are described in Vinciguerra et al. "Growth mechanisms in chemical vapour deposited carbon nanotubes" Nanotechnology (2003) 14, 655; Perez-Cabero et al. “Growing mechanism of CNTs: a kinetic approach" J. Catal. (2004) 224, 197-205; Gavillet et al. “Microscopic mechanisms for the catalyst assisted growth of single-wall carbon nanotubes” Carbon. (2002) 40, 1649-1663 and Amelinckx et al. "A formation mechanism for catalytically grown helix-shaped graphite nanotubes" Science (1994) 265, 635-639, and the contents of these regarding the manufacture of metal nanoparticles are incorporated herein by reference. In one aspect, the weight ratio of water:surfactant is from 2:1 to 1:5, preferably from 1:1 to 1:4.

[0043] The metal catalyst nanoparticles are used in a thermally cracked oil-containing bicontinuous, w / o or o / w microemulsion. In one embodiment, the bicontinuous microemulsion is most preferred. Advantageously, the uniformity of the metal particles is controlled in the (bicontinuous) microemulsion by mixing a first (bicontinuous) microemulsion in which the aqueous phase contains a metal complex salt capable of being reduced to metal particles, and a second (bicontinuous) microemulsion in which the aqueous phase contains a reducing group capable of reducing the metal complex salt. When mixed, the metal complex is reduced to form metal particles. The controlled (bicontinuous) emulsion environment stabilizes the particles against calcination or Ostwald ripening. The size, concentration and durability of the catalyst particles are easily controlled. For example, it is considered an everyday experimental method to adjust the average metal particle size within the above range by changing the molar ratio of the metal precursor to the reducing agent. An increase in the relative amount of the reducing agent results in smaller particles. The metal particles thus obtained are monodisperse, and the deviation from the average particle size is preferably within 10%, more preferably within 5%. Also, the current technology does not limit the metal precursor as long as it is reduced.

[0044] Non-limiting examples of nanoparticles contained in the carbon nanofiber-containing carbon network are noble metals (Pt, Pd, Au, Ag), iron group elements (Fe, Co and Ni), Ru and Cu. Suitable metal complexes include, but are not limited to, (i) platinum precursors such as H 2 PtCl 6 ; H 2 PtCl 6 .xH 2 O; K 2 PtCl 4 ; K 2 PtCl 4 .xH 2 O; Pt(NH 3 ) 4 (NO 3 ) 2 ; Pt(C 5 H 7 O 2 ) 2 , (ii) ruthenium precursors such as Ru(NO)(NO 3 ) 3 ; Ru(dip)3 Cl 2 [dip = 4,7-diphenyl-1,10-phenanthroline]; RuCl 3 , (iii) a palladium precursor such as Pd(NO 3 ) 2 , or (iv) a nickel precursor such as NiCl 2 or NiCl 2 .xH 2 O; Ni(NO 3 ) 2 ; Ni(NO 3 ) 2 .xH 2 O; Ni(CH 3 COO) 2 ; Ni(CH 3 COO) 2 .xH 2 O; Ni(AOT) 2 [AOT = bis(2-ethylhexyl)sulfosuccinate], where x may be an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10, and is usually 6, 7 or 8. Non-limiting and suitable reducing agents are hydrogen gas, sodium borohydride, sodium bisulfate, hydrazine or hydrazine hydrate, ethylene glycol, methanol and ethanol. Also, citric acid and dodecylamine are suitable. The type of metal precursor is not an essential part of the present invention.

[0045] (Bicontinuous) The metal of the particles of the microemulsion preferably is selected from the group consisting of Pt, Pd, Au, Ag, Fe, Co, Ni, Ru, and Cu, and mixtures thereof, to control the morphology of the ultimately formed carbon structure network. The metal nanoparticles are ultimately embedded within these structures, and the metal particles physically adhere to the structures. The metal particles are necessary for the formation of these networks, and in fact, it has been found that the networks are formed using the modified carbon black production method according to the present invention, and the yield increases with the metal particle concentration. In a preferred embodiment, the concentration of the active metal is at least 1 mM, preferably at least 5 mM, preferably at least 10 mM, more preferably at least 15 mM, more preferably at least 20 mM, particularly at least 25 mM, most preferably 3500 mM or less, preferably 3000 mM or less. In one embodiment, the concentration of the metal nanoparticles is 250 mM or less. These are the concentration of the catalyst relative to the amount of the aqueous phase of the (bicontinuous) microemulsion.

[0046] The atomization of the pyrolysis oil-containing single-phase emulsion is preferably achieved by spraying using the nozzle system 4, whereby the droplets of the emulsion contact the hot waste gas a1 in the reaction zone 3b, and traditional carbonization, network formation, and subsequent condensation occur, making it possible to produce the porous chemically interconnected carbon nanofiber-containing carbon network e according to the present invention. The injection step is preferably carried out at a high temperature above 600 °C, preferably 700 - 3000 °C, more preferably 900 - 2500 °C, more preferably 1100 - 2000 °C.

[0047] Sustainable porous carbon network The network of the present invention can be characterized as follows.

[0048] The terms "sustainable porous carbon network" and "sustainable porous carbon network material" are used in the same meaning.

[0049] First of all, these networks are circular, that is, carbon is produced from waste products (i.e., end-of-life tires, non-recyclable plastics or biomass waste). By converting this waste into useful carbon products, up to 150 million tons of CO 2 can be reduced annually. This does not include the benefits that carbon products can bring when used in composites with elastomers or plastics. Circular or sustainable carbon products, when used in tires, can reduce rolling resistance and / or wear resistance, or can be used to enhance the mechanical and electrical properties of recycled plastics; opening the way to truly sustainable high-performance plastics and tires. At the end of life, the product can be fully recycled or used again as a pyrolysis feedstock to close the loop. In this context, the terms "sustainable" and "circular" in the present invention are used in the same meaning, and this term has a commercial and technical meaning beyond its manufacturing method. Products obtained from unrefined pyrolysis oil can be recognized as such and can also be described as products with a reduced carbon footprint.

[0050] In the present invention, sustainability is preferably understood as striving to improve the efficiency of the use of natural resources in order to meet human needs for chemical products and services through the design, manufacture and use of efficient, effective, safe and more environmentally friendly chemical products and manufacturing methods (OECD definition). The pyrolysis refining process is not an attractive candidate for making pyrolysis more sustainable for carbon black production, but rather adds cost to the manufacturing process. Therefore, the direct use of pyrolysis oil in commercial methods for carbon black production results in the achievement of sustainability. Products that are the result of such processing of unrefined recycled pyrolysis are understood by those skilled in the art and consumers to be sustainable products (i.e., carbon network products are made from unrefined pyrolysis oil).

[0051] Compared with the carbon from crude oil, the carbon produced from pyrolysis oil has a low pH and has a significant amount of polar groups, such as carboxyl, hydroxyl and epoxy, on the surface of these networks. These groups increase the affinity between the network structure in polar polymers (i.e., epoxy resins, polyamides and polyesters, SSBR functionalized for silica) and acidic reactive molecules (maleic anhydride grafted polypropylene of polyethylene, silanes and aminosilanes). In particular, the carbon produced from pyrolysis oil has a maximum pH of 7.5. Without being bound by theory, this results in a better interaction with the matrix and thus leads to products with improved characteristics, for example, the interaction between the filler and the matrix can be improved. The pH of the final product is preferably 4 to 7.5, most preferably 5.5 to 7.5, more preferably 5.5 to 7.3, and most preferably 5.5 to 7.0.

[0052] One skilled in the art will understand that a porous network refers to a three-dimensional structure through which liquids or gases can pass. A porous network may also be referred to as a porous medium or a porous material. The pore volume of the porous carbon network according to the present invention, when measured by the Brunauer, Emmett and Teller (BET) method (ASTM D6556-09), is 0.1 to 1.5 cm 3 / g, preferably 0.2 to 1.5 cm 3 / g, more preferably 0.3 to 1.3 cm 3 / g, most preferably 0.4 to 1.5 cm 3 / g.

[0053] The pore diameter inside the particles of the carbon network containing carbon nanofibers may be 5 to 150 nm, preferably 10 to 120 nm, and most preferably 10 to 100 nm when measured by mercury intrusion porosimetry (ASTM D4404-10).

[0054] The internal volume of the particles of the carbon network containing carbon nanofibers is 0.10 to 1.1 cm when measured by mercury intrusion porosimetry (ASTM D4404-10).3 / g, preferably 0.51 to 1.0 cm 3 / g, most preferably 0.59 to 0.91 cm 3 It may also be / g.

[0055] The porous carbon network (or porous carbon network particles) according to the present invention can be considered as a large molecule in which carbon atoms are interconnected essentially by covalent bonds. Here, in contrast to the interparticle pores called porous networks made up of a plurality of molecules or particles formed by the space between physically aggregated particles or molecules, the porous carbon network particles are understood to be particles containing chemically interconnected (i.e., covalently bonded) fibers having intraparticle pores. Since the carbon network particles according to the present invention can be considered as large molecules with pores embedded therein, in the present invention, the intraparticle pores may be understood as intramolecular pores. Therefore, the intraparticle pores and the intramolecular pores have the same meaning in this specification and may be used interchangeably when explaining the porous network of the present invention. Compared with traditional carbon black without an intraporous structure within the carbon black particles, the aggregates of carbon black particles can have interparticle pore characteristics. Interparticle / intermolecular is the space between physically aggregated particles (networks), while intraparticle / intramolecular is the space inside the network itself.

[0056] Without being bound by theory, the benefit of having a network containing intraparticle pores rather than a network containing interparticle pores is thought to be that the latter is more robust and more elastic against breakage and fracture when a force is applied. Intraparticle pores refer to pores existing inside (nano) particles. Interparticle pores refer to pores resulting from stacking individual particles. Interparticle pores are weak due to the particle-particle interface and tend to collapse. Intraparticle pores are strong due to the surrounding covalently bonded structure and can withstand large forces and high pressures without collapsing.

[0057] As described above, known reinforcing agents, such as carbon black, consist of aggregates or agglomerates of spherical particles, which may form a three-dimensional structure without covalent bonds (without "chemically interconnecting") between the individual particles, and thus have interparticle pores. In summary, intraparticle pores refer to a state in which carbon atoms surrounding the pores are covalently bonded, and interparticle pores refer to pores existing between physically aggregated or coagulated particles.

[0058] Since the network of the present invention can be considered as one large molecule, it is not necessary to fuse particles or parts of the network together. Thus, the porous network of chemically interconnected carbon nanofibers is a carbon network containing unfused intraparticle porous chemically interconnected carbon nanofibers having intraparticle porosity. In a preferred embodiment, the intraparticle pore volume can be characterized as further described below with respect to, for example, mercury intrusion porosimetry (ASTM D4404-10) or the Brunauer, Emmett and Teller (BET) method (ISO9277:10).

[0059] It will be readily understood by those skilled in the art that the term "chemically interconnected" in the porous network containing chemically interconnected carbon nanofibers means a state in which carbon nanofibers are interconnected with other nanofibers by chemical bonds. It is also understood that chemical bonds are synonymous with molecular bonds or covalent bonds. Usually, the location where carbon nanofibers are connected is called a joint or a fiber joint, and thus it may also be simply called a "shared joint". These terms are used with the same meaning in this specification. In the carbon network according to the present invention, the joints are formed by covalently bonded carbon atoms. Further, the fiber length is defined as the distance between joints connected by a fibrous carbon material.

[0060] At least a part of the fibers of the carbon nanofiber-containing network of the present invention is crystalline carbon nanofibers. In the present invention, preferably at least 20% by weight, more preferably at least 40% by weight, even more preferably at least 60% by weight, even more preferably at least 80% by weight, and most preferably at least 90% by weight of the carbon in the carbon network is crystalline. Alternatively, the amount of crystalline carbon is 20 to 90% by weight, more preferably 30 to 70% by weight, and more preferably 40 to 50% by weight based on the total carbon of the carbon network of the present invention. Here, crystallinity has its ordinary meaning and refers to the degree of structural regularity in the material. In other words, the carbon atoms in the nanofibers are arranged regularly and periodically to some extent. Crystalline flakes or masses can be called crystallites. Therefore, carbon crystallites are individual carbon crystals. The scale of the size of carbon crystallites is the stacking height of the graphite layers. Carbon black that meets the ASTM standard has a stacking height of the graphite layers in the crystallite of 11 to 13 Å. The stacking height of the carbon nanofiber-containing carbon network of the present invention is at least 15 Å, preferably at least 16 Å, more preferably at least 17 Å, even more preferably at least 18 Å, even more preferably at least 19 Å, and even more preferably at least 20 Å. If necessary, a carbon network having crystallites with a size of 100 Å can be produced. Therefore, the stacking height of the carbon network of the present invention is at most 100 Å or less, more preferably 80 Å or less, even more preferably 60 Å or less, even more preferably 40 Å or less, and even more preferably 30 Å or less. Therefore, it is understood that the stacking height of the graphite layers in the crystallites in the carbon network of the present invention is 15 to 90 Å, more preferably 16 to 70 Å, even more preferably 17 to 50 Å, even more preferably 18 to 30 Å, and most preferably 19 to 25 Å.

[0061] The porous chemically interconnected carbon nanofiber-containing carbon network can be defined as having chemically interconnected carbon nanofibers, where the carbon nanofibers are interconnected via junctions and several (usually 3 or more, preferably at least 10 or more) nanofibers are covalently bonded. The carbon nanofibers are part of the network between the junctions. The fibers are usually solid (i.e., non-hollow) and preferably have an average diameter or thickness of 1 to 500 nm, preferably 5 to 350 nm, more preferably 100 nm or less, and in one aspect 50 to 100 nm, compared to an average particle size of 10 to 400 nm of carbon black particles. In one aspect, the average fiber length (i.e., the average distance between two junctions) can be measured, for example, by SEM and is preferably 30 to 10,000 nm, more preferably 50 to 5,000 nm, more preferably 100 to 5,000 nm, more preferably at least 200 to 5,000 nm.

[0062] The nanofiber or structure can preferably be described by an average aspect ratio of fiber length to thickness of at least 2, preferably at least 3, more preferably at least 4, most preferably at least 5, and preferably less than 50, in good contrast to amorphous (physically associated) aggregates formed from spherical particles obtained by conventional carbon black production.

[0063] The carbon nanofiber structure can be defined as a carbon network formed by chemically interconnected carbon nanofibers. The carbon network has openings between the carbon nanofibers and has a three-dimensional structure accessible to a continuous phase which may be a liquid phase such as a solvent or an aqueous phase, a gas phase or other phases. The carbon network has a diameter of at least 0.5 μm, preferably at least 1 μm, preferably at least 5 μm, more preferably at least 10 μm, even more preferably at least 20 μm, most preferably 25 μm in all dimensions. Alternatively, the carbon network has a diameter of at least 1 μm in two dimensions and a diameter of at least 5 μm, preferably at least 10 μm, more preferably at least 20 μm, most preferably 25 μm in the other dimension. Throughout this specification, the term "dimension" is used in its ordinary meaning and refers to spatial dimensions. There are three spatial dimensions orthogonal to each other, which define space in its ordinary physical sense. Further, the carbon network can have a diameter of at least 10 μm in two dimensions and a diameter of at least 15 μm, preferably at least 20 μm, more preferably at least 25 μm, more preferably at least 30 μm, most preferably at least 50 μm in the other dimension.

[0064] When measured by laser diffraction (ISO13320) or dynamic light scattering analysis, the aggregate size of the carbon nanofiber-containing carbon network may be 0.1 to 100 μm, preferably 1 to 50 μm, more preferably 4 to 40 μm, most preferably 5 to 35 μm, more preferably 6 to 30 μm, more preferably 7 to 25 μm, most preferably 8 to 20 μm.

[0065] When measured by the Brunauer, Emmett and Teller (BET) method (ISO9277:10), the surface area of the carbon nanofiber-containing carbon network is preferably 40 to 120 m 2 / g, more preferably 45 to 110 m 2 / g, even more preferably 50 to 100 m 2 / g, most preferably 50 to 90 m 2 / g.

[0066] The porous chemically interconnected carbon nanofiber-containing carbon network may also include carbon black particles incorporated as part of the network. These particles are found at the junctions between the carbon nanofibers, although carbon black particles may also be present in other parts of the network. The diameter of the carbon black particles is preferably at least 0.5 times the diameter of the carbon nanofibers, more preferably at least the same diameter as the carbon nanofibers, even more preferably at least 2 times the diameter of the carbon nanofibers, even more preferably at least 3 times the diameter of the carbon nanofibers, still more preferably at least 4 times the diameter of the carbon nanofibers, and most preferably at least 5 times the diameter of the carbon nanofibers. The diameter of the carbon black particles is preferably at most 10 times the diameter of the carbon nanofibers. Such a mixed network is referred to as a hybrid network.

[0067] The porous chemically interconnected carbon nanofiber-containing carbon network has a functionalized surface. In other words, the surface contains groups that change the hydrophobicity of the surface typical of carbon to a more hydrophilic nature. The surface of the carbon network contains carboxylic acid groups, hydroxyl groups, and phenols. These groups impart a certain degree of polarity to the surface and can modify the properties of the material in which the functionalized carbon network is embedded. Without wishing to be bound by theory, the functional groups are thought to bind to the elastomer, for example, by forming hydrogen bonds, and thus increase the elasticity of the material. Accordingly, at least the stiffness and durability of the material are modified, which can result in lower rolling resistance and increased operating life of the reinforced elastomer, particularly a tire or conveyor belt containing said reinforced elastomer.

[0068] The porous chemically interconnected carbon nanofiber-containing carbon network may contain metal catalyst nanoparticles. These are fingerprints of the preparation method. The average particle size of these particles may be from 1 nm to 100 nm. Preferably, the particles are monodisperse particles having a variation within 10%, more preferably within 5% of their average particle size. Non-limiting examples of the nanoparticles contained in the carbon nanofiber-containing carbon network include noble metals (Pt, Pd, Au, Ag), iron group elements (Fe, Co, and Ni), Ru, and Cu. Suitable metal complexes are (i) platinum precursors such as H 2 PtCl 6 ; H 2 PtCl 6 .xH 2 O; K 2 PtCl 4 ; K 2 PtCl 4 .xH 2 O; Pt(NH 3 ) 4 (NO 3 ) 2 ; Pt(C 5 H 7 O 2 ) 2 , (ii) ruthenium precursors such as Ru(NO)(NO 3 ) 3 ; Ru(dip) 3 Cl 2 [dip = 4,7-diphenyl-1,10-phenanthroline]; RuCl 3 , (iii) palladium precursors such as Pd(NO 3 ) 2 , or (iv) nickel precursors such as NiCl 2 or NiCl 2 .xH 2 O; Ni(NO 3 ) 2 ; Ni(NO 3 ) 2 .xH 2 O; Ni(CH 3 COO) 2 ; Ni(CH 3 COO) 2 .xH 2 O; Ni(AOT)2 It may be [AOT = bis(2-ethylhexyl)sulfosuccinate], where x may be an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10, and usually may be 6, 7 or 8.

[0069] The use of these sustainable porous networks is not limited, but the present invention relates in particular to the use of these networks in composites and to sustainable composites comprising the carbon structure network according to the invention and one or more polymers, the network being added to the polymer-based composite for mechanical strength, electrical conductivity or thermal conductivity. The network may be added in an amount adapted to the desired performance, for example 1 to 70% by weight, more preferably 10 to 50% by weight, even more preferably 20 to 40% by weight, based on the total polymer weight in the composite. On one side, the composite exhibits a network concentration-dependent modulus of elasticity (E modulus of elasticity, i.e., an increase with increasing concentration of the network), for example when measured according to ISO527.

Examples

[0070] Example 1 Preparation of a crystalline carbon structure network Thermal decomposition oil o / w type microemulsions were prepared by the method of the present invention from the following: a) Tire pyrolysis oil (TPO) obtained from Scandinavian Enviro systems with a carbon content of 86 - 85% by weight, a sulfur content of 0.7 - 0.9% by weight, and a water content of 9 - 13% by weight b) An aqueous phase containing iron chloride as a catalyst c) A polyethylene oxide-based surfactant having an aromatic hydrophobic group as a surfactant.

[0071] For different compositions of the microemulsion, the appearance of the elongated structure observed by SEM was analyzed. The cases where the elongated structure was observed were as follows:

[0072]

Table 1

[0073] Using the method of the present invention for injecting the pyrolysis oil emulsion described above, a crystalline carbon structure network can be produced. The furnace reactor used in this example was a Carcass N550 reactor with a residence time of 294 milliseconds, operating at 1200 - 2000 °C, and a raw material production rate of 3.65 tons per hour. The characteristics of this network obtained by this method are as follows:

[0074]

Table 2

[0075] The low pH of the products obtained by this method improves the interaction with the surface active groups on the surface of these networks, thereby improving the interaction between the filler and the matrix for the carbon produced from the pyrolysis oil. Therefore, it is considered to be a better filler than carbon from anthracene oil.

[0076] Example 2 pH of carbon from different oils Three batches of carbon networks were synthesized using three emulsions containing polyethylene oxide-based surfactant with aromatic hydrophobic groups (70 wt%), water (10 wt%) and FeCl 3 (less than 1 wt%), with the oil components varying respectively: - Composition 1: Anthracene oil; - Composition 2: Tire pyrolysis oil (Scandinavian Enviro systems); and - Composition 3: Bio-pyrolysis oil (obtained from BTG).

[0077] 30 mg of the produced network powder was ground, and the ground powder was mixed with demineralized water (demi-water) and 2 drops of acetone. After the mixture was sonicated for 1 minute, the pH was measured.

[0078] The pH values obtained were 7.7, 7.3 and 6.8 respectively.

[0079] The surfaces of the pyrolysis oil-based carbon networks of Compositions 2 and 3 had carboxylic acid, hydroxyl and / or epoxy groups. These polar groups increased the affinity of such structures in polar polymers (i.e., epoxy resins, polyamides and polyesters, SSBR functionalized for silica) with acidic reactive molecules (maleic anhydride grafted polypropylene of polyethylene, silanes and aminosilanes).

Claims

1. A method for producing a crystalline carbon nanofiber network from pyrolysis oil in a reactor 3 having a reaction zone 3b and a quenching zone 3c, comprising injecting a single-phase emulsion c, which is a microemulsion containing pyrolysis oil and metal catalyst nanoparticles, into the reaction zone 3b at a temperature above 600 °C and below 3000 °C to produce a crystalline carbon nanofiber network e, transferring the network e to the quenching zone 3c, and quenching or terminating the formation of the crystalline carbon nanofiber network by spraying water d in the quenching zone, wherein the pyrolysis oil phase in the emulsion has a carbon content of at least 40 wt%, an added water content of 50 wt% or less, a sulfur content of 4 wt% or less, and an oxygen content of 50 wt% or less based on the total weight of the pyrolysis oil.

2. The reactor is a furnace carbon black reactor 3 having a combustion zone 3a, a reaction zone 3b, and a quenching zone 3c along its axis, burning fuel a in an oxygen-containing gas b, and moving waste gas a1 from the combustion zone 3a to the reaction zone 3b to generate a flow of hot waste gas a1 in the combustion zone, spraying a microemulsion c containing pyrolysis oil and metal catalyst nanoparticles into the reaction zone 3b containing the hot waste gas, carbonizing the microemulsion at a temperature above 600 °C and below 3000 °C, and quenching or terminating the reaction by spraying water d in the quenching zone 3c to obtain a crystalline carbon nanofiber network e. The method according to claim 1.

3. The method according to claim 1 or 2, wherein the temperature is above 1000 °C and below 2000 °C.

4. The method according to any one of claims 1 to 3, wherein the emulsion contains at least 1 mM of metal catalyst nanoparticles.

5. The method according to claim 4, wherein the average particle size of the metal catalyst nanoparticles is 1 to 100 nm.

6. The method according to any one of claims 1 to 5, wherein at least 50 wt% of the carbon source of the network is provided as pyrolysis oil in the single-phase emulsion.

7. The method according to any one of claims 1 to 5, wherein all of the carbon source of the network is provided as pyrolysis oil in the single-phase emulsion.

8. The method according to any one of claims 1 to 7, wherein the reactor residence time of the pyrolysis oil in the single-phase emulsion c is less than 5 seconds.

9. The method according to claim 8, wherein the reactor residence time is 10 to 500 milliseconds.

10. The method according to any one of claims 1 to 9, wherein the sulfur content of the pyrolysis oil supplied to the reactor 3 is 0.5 to 4.0% by weight based on the weight of the pyrolysis oil.

11. The method according to any one of claims 1 to 10, wherein the oxygen content of the pyrolysis oil supplied to the reactor 3 is 10 to 50% by weight based on the weight of the pyrolysis oil.

12. A sustainable porous carbon network material comprising chemically interconnected carbon nanofibers, wherein the intra-particle pore diameter of the pores in the network is 5 to 150 nm by mercury intrusion porosimetry according to ASTM D4404-10, at least 20% by weight of the carbon in the carbon network is in crystalline form, the average aspect ratio of the fiber length to thickness of the carbon nanofibers is at least 2, the pH of the obtained carbon network is at most 7.5, and the carbon is provided by pyrolysis oil.

13. The sustainable porous carbon network material according to claim 12, wherein the pH of the carbon network is 5.5 to 7.

5.

14. A sustainable product, sustainable plastic or tire product comprising the sustainable porous carbon network according to claim 12.

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