Systems and methods for synthesizing carbon nanotubes and hybrid materials via catalytic chemical vapor deposition.

Abstract

A reactor system and associated method configured to produce carbon-containing materials by exposing a carbon-containing reactant gas to catalyst particles. The reactor system includes a reactor including a heated reaction volume in which the reactant gas is exposed to the catalyst, at least one reactant gas inlet port to the reaction volume, and at least one catalyst particle inlet to the reaction volume. The catalyst particles are heated prior to the catalyst particles contacting the reactant gas.

Description

Technical Field

[0001] Cross - reference to Related Applications This application claims priority to U.S. Provisional Patent Application No. 63 / 251,334, filed on October 1, 2021.

[0002] Background This disclosure relates to the synthesis of carbon nanotubes and related hybrid materials.

Background Art

[0003] The chemical and energy industries are facing new technical challenges to significantly reduce the levels of gas emissions in the atmosphere that cause global warming. New processes or catalytic reactors are being developed to maximize the utilization of each molecule such as carbon and hydrogen without emitting CO2. Companies manufacturing various types of carbon (such as carbon nanotubes, carbon black, artificial graphite, activated carbon, etc.) from catalytic processes or thermal processes using methane, ethylene, propylene, acetylene, carbon monoxide, and other carbon sources generate a large amount of CO2 by burning these unreacted molecules or solid wastes during the process. Therefore, it is important to develop new processes, catalysts, and more efficient reactors that can increase the selectivity and yield of products, utilize reaction gases more effectively, avoid combustion that generates CO2, and significantly reduce the production cost of products.

[0004] There are several commercial processes for producing carbon nanotubes. The most commonly used is catalytic chemical vapor deposition (CCVD), because it offers superior control over the chirality distribution in the synthesis of single-walled carbon nanotubes (SWCNTs), resulting in consistent morphological properties of the product and scalability in the production of multi-walled carbon nanotubes (MWCNTs). CCVD methods used for large-scale carbon nanotube production employ either fluidized bed reactors or rotary kiln reactors. Each of these reactors has its advantages and disadvantages. For example, fluidized bed reactors allow for better heat and mass transfer between the reaction gas and catalyst, resulting in more precisely controlled nanotube product structures. Catalytic reactions are also more efficient. The disadvantage is that it is difficult to use finely powdered catalysts due to particle entrapment and fluidization challenges. Rotary kiln reactors are easier to operate continuously even with finely powdered catalysts, but they are limited by the poor contact quality between the reaction gas and catalyst. These constraints can be overcome by an optimized rotary tube reactor design. [Overview of the Initiative]

[0005] This disclosure includes optimized reactor designs, as well as systems, processes, and methods for producing carbon nanotubes (CNTs) and CNT hybrid materials. The reactants are arranged to come into contact at a desired reaction temperature, or at a temperature close to the desired reaction temperature. This improves both the yield and quality of the CNTs and CNT hybrid materials. In some embodiments, the particulate matter (catalyst and other solid materials) and the reaction gas are preheated to the reaction temperature before contact in the reactor. At least the catalyst supply includes means for protecting the catalyst in an inert environment until contact with the reaction gas.

[0006] In some embodiments, a rotating tube catalytic reactor is used. In some embodiments, the catalyst is supplied to the reactor through an inner tube under a flow of an inert gas (e.g., N2, He, Ar), thereby bringing the solid particles into contact with a gaseous carbon source (ethylene, acetylene, methane, ethane, carbon monoxide, etc.) at the same temperature at which the catalytic reaction occurs. Under such conditions, a higher carbon nanotube yield is achieved compared to prior art reactor designs, and the CNTs have a higher aspect ratio (longer tubes with smaller diameters). To improve the quality of gas-solid contact during the reaction, a flyer or other particle distribution structure can be placed inside the rotating tube. In some embodiments, the residence time of the reactants in the reactor is controlled. In some embodiments, the volume of the solid reactants is about 15% to about 30% of the reactor volume, more commonly up to about 30%.

[0007] Another aspect of the process design is the use of an H2-carbon source separation membrane at the reactor outlet. This separation allows for the recycling of the carbon source, improving efficiency and enabling greater utilization of carbon molecules flowing into the process. This makes the process environmentally friendly in that it produces little to no CO2 emissions, and the hydrogen can be used for other industrial applications, such as other chemical processes that require hydrogen, or for the production of thermal or electrical energy. Furthermore, this reactor design allows for the use of unsupported metal catalysts, providing greater flexibility in the production of various carbon nanomaterials.

[0008] The present invention differs from and is advantageous over the prior art in at least the following respects:

[0009] A method for supplying a catalyst to a reactor so that the catalyst particles reach the same temperature as the carbon source in the gas phase.

[0010] Recycling unreacted gases makes the process more economically profitable and avoids the emission of greenhouse gases.

[0011] The use of a hydrogen membrane to selectively separate the carbon source and H2 produced during the reaction.

[0012] Use of hydrogen produced in other processes, or use in heat sources, power generation, and vehicle transport, etc.

[0013] Flexibility to use supported or unsupported active metal catalysts for the synthesis of various carbon nanomaterials.

[0014] Inclusion of other solid particulate materials for generating CNT hybrid materials. CNT hybrid materials in both carpet and mesh forms are disclosed in U.S. Patent Application No. 17 / 515,520, filed October 31, 2021, and U.S. Patent Application No. 17 / 667,373, filed February 8, 2022. The entire disclosures of these two applications are incorporated herein by reference for all purposes.

[0015] A pre-blended catalyst with other solid particulate materials.

[0016] Both the catalyst and the gaseous carbon source are brought to the desired reaction temperature before contact.

[0017] If other particles are endothermic or exothermic, the particles can be pre-treated as desired. For example, the particles can be dried or heated so as not to release moisture or unwanted reactants in the reaction zone. Such pretreatment can be achieved in some embodiments using a second rotary kiln reactor located upstream of the reactor.

[0018] In some embodiments, the reactor is configured to facilitate pre-operation cleaning in terms of both physical cleaning and burnout following each reaction.

[0019] All embodiments and features described below can be combined in any way that is technically possible.

[0020] In one embodiment, a reactor system configured to produce a carbon-containing material by exposing a carbon-containing reaction gas to catalyst particles includes a reactor comprising a heated reaction volume from which the reaction gas is exposed to catalyst particles, at least one reaction gas inlet port to the reaction volume, and at least one catalyst particle inlet to the reaction volume. In this system and method, the catalyst particles are heated before contact with the reaction gas.

[0021] Some embodiments include one of the above and / or below features, or any combination thereof. In embodiments, the carbon-containing material includes at least one of the following: carbon nanotube-containing material, carbon nanotube hybrid material, and carbon nanotube. In embodiments, the carbon nanotube hybrid material includes carbon nanotube-carbon black, carbon nanotube-graphite, carbon nanotube-graphene nanoplatelet, carbon nanotube-silicon, carbon nanotube-alumina, carbon nanotube-magnesium oxide, carbon nanotube-silica, carbon nanotube-activated carbon, carbon nanotube-cementaceous material, and carbon nanotube-SiO x The material comprises at least one of the following: carbon nanotube-carbon fiber material.

[0022] In some embodiments, one of the above and / or below features, or any combination thereof, is included. In embodiments, the catalyst particle inlet includes a duct leading from outside the reactor into the reaction volume. In embodiments, the reactor includes a rotating tube reactor. In embodiments, the reaction volume is heated to the reaction temperature. In embodiments, the catalyst particles are heated to approximately the reaction temperature before contact with the reaction gas. In embodiments, the reactor has an outlet for carbon-containing material, unreacted reaction gas, and reaction byproducts generated within the reactor. In embodiments, the system further includes a gas / solid separator fluidly connected to the reactor outlet and configured to separate the carbon-containing material from unreacted reaction gas and reaction byproducts. During purging of air from the catalyst-containing vessel or during purging of reaction gases (e.g., ethylene and hydrogen) from the reactor, the flow of inert gas may entrain catalyst or product particulate matter. These particles should be captured before being released into the atmosphere. Therefore, in one embodiment, the reactor system includes a purging system for the catalyst and product vessels and a particulate filter located in the gas outlet line of the reactor. In the embodiment, the system further includes a gas / liquid separator container, which is fluidly coupled to the gas outlet and configured to separate the polymerized carbon compound produced by the thermal decomposition of the carbon source from unreacted reaction gases and reaction byproducts by condensation. In the embodiment, the reactor system further includes a gas recycling system configured to return at least a portion of the unreacted reaction gases to the reactor. In the embodiment, the reactor system further includes a gas separator configured to separate the unreacted reaction gases from the reaction byproducts. In one embodiment, the reactor system includes a plurality of gas sampling ports used for compositional analysis by mass spectrometry or other analytical techniques. These gas sampling ports may be located at the reactor inlet and reactor outlet, as well as in the recycling system. In the embodiment, the reaction byproducts include hydrogen. In the embodiment, the reactor system further includes a product container configured to hold the carbon-containing material separated by the gas / solid separator. In the embodiment, the product container is flushed with an inert gas. The process gas can be supplied to the reactor in the same or countercurrent direction as the catalyst supply.

[0023] Some embodiments include one of the features described above and / or below, or any combination thereof. In an embodiment, the catalyst particle inlet includes a catalyst supply pipe leading from outside the reactor into the reaction volume. In an embodiment, the catalyst supply pipe extends along about 1 / 6 to about 1 / 3 of the length of the reactor. In an embodiment, the reactor has a diameter and the catalyst supply pipe has a diameter of about 1 / 3 to about 1 / 2 of the diameter of the reaction volume. In an embodiment, the reactor system further includes a catalyst supply system configured to supply catalyst into and from the supply pipe into the reactor. In an embodiment, the catalyst supply system includes a vibrating feeder configured to move the catalyst along and out of the supply pipe at a controllable rate. In an embodiment, the catalyst supply system further includes a catalyst holding container that is washed with an inert gas and configured to supply the catalyst to the vibrating feeder. In an embodiment, the catalyst supply system further includes a screw feeder configured to supply the catalyst to the holding container at a controllable rate. In an embodiment, the catalyst supply system further includes a screw feeder supply container that is washed with an inert gas and configured to supply the catalyst to the screw feeder. In one embodiment, the temperature of the reaction volume is measured through a thermowell. In this embodiment, the catalyst supply tube has an outlet located within the reaction volume, and the thermowell is positioned close to the outlet of the catalyst supply tube.

[0024] Some embodiments include one of the above and / or below features, or any combination thereof. In the embodiments, the reaction volume is heated to at least about 400°C. In the embodiments, the reaction volume and catalyst are heated to at least about 400°C. In the embodiments, the reaction volume and catalyst are heated to at least about 650°C. In the embodiments, the residence time of the catalyst in the reactor is at least 6 minutes. In the embodiments, the hydrogen composition in the reaction gas is at most about 30%.

[0025] Some embodiments include one or more of the above and / or below features, or any combination thereof. In an embodiment, the carbon-containing material includes carbon nanotubes (CNTs). In an embodiment, the CNTs have a length of at least about 7 microns. In an embodiment, the CNTs have a length-to-diameter ratio of at least about 500. In an embodiment, the CNTs include one or more of multi-walled CNTs, double-walled CNTs, and single-walled CNTs. In an embodiment, when ethylene is the carbon source, the reaction volume and the catalyst are heated to at least 700 °C. In an embodiment, when methane is the carbon source, the reaction volume and the catalyst are heated to at least 950 °C. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The various aspects of at least one embodiment will be described below with reference to the accompanying drawings, which are not intended to be drawn to scale. Each drawing is included to provide an illustration and further understanding of the various aspects and embodiments, and is incorporated herein and constitutes a part of this specification, but is not intended as a definition of the limitation of the present invention. In the drawings, the same or substantially the same components shown in the various drawings may be represented by like reference characters or numerals. For clarity, not all components are shown in all of the drawings.

[0027] [Figure 1] It is a schematic diagram of an exemplary rotary tube reactor design and a CNT production process of the present invention. [Figure 2] It shows the carbon yield at different reaction temperatures. [Figure 3] It shows the influence of the hydrogen composition in the reaction gas on the carbon yield. [Figure 4] It includes a SEM image of multi-walled CNTs (MWCNTs) of Experiment 1. [Figure 5] It includes a SEM image of MWCNTs of Experiment 6. DETAILED DESCRIPTION OF THE INVENTION

[0028] The examples of systems, methods, and apparatus described herein are not limited to the configuration details and arrangement of components described in the following description or illustrated in the accompanying drawings. The systems, methods, and apparatus can be implemented in other embodiments and can be carried out in a variety of ways. Specific examples provided herein are for illustrative purposes only and are not intended to limit the scope of the system, method, and apparatus. In particular, any functions, components, elements, and features discussed in relation to any one or more embodiments are not intended to preclude similar roles in other embodiments.

[0029] The examples disclosed herein can be combined with other examples in any way consistent with at least one of the principles disclosed herein, and references to “examples,” “several examples,” “alternative examples,” “various examples,” “one example,” etc., are not necessarily mutually exclusive and are intended to indicate that a particular feature, structure, or property described may be included in at least one example. Not all such terms in this specification necessarily refer to the same example.

[0030] Furthermore, the expressions and terminology used herein are for illustrative purposes only and should not be considered limiting. Any singular reference herein to an example, component, element, action, or function of a computer program product, system, or method may also include plural embodiments, and any plural reference herein to an example, component, element, action, or function may also include singular examples. Accordingly, singular or plural references are not intended to limit the systems or methods, their components, actions, or elements currently disclosed. The use herein of “includes,” “contains,” “has,” “contains,” “involves,” and variations thereof is intended to include the items listed thereafter and their equivalents, as well as additional items. References to “or” may be interpreted as comprehensive, so as to whether the term using “or” can refer to a single term, multiple terms, or all of the terms described.

[0031] Figure 1 is a schematic diagram of an exemplary rotating tube reactor system 10 configured to be used to achieve the CNT / CNT hybrid production process of this disclosure. The following description illustrates certain aspects of this disclosure but does not limit the scope of this disclosure.

[0032] The catalyst supply system 16 can operate as follows: Powdered catalyst particles are supplied to the catalyst supply storage container 1. Subsequently, air is removed from the catalyst supply storage container 1 using a flow of inert gas. The inert gas can be preheated to a temperature of 60-150°C to remove moisture from the catalyst during the purging process. The catalyst particles are then transferred to a second catalyst supply storage container 2 via a screw feeder. This device controls the amount of catalyst supplied to the reactor 12. The catalyst and reaction gas supply system 14 can operate as follows: Catalyst particles contained in the second catalyst supply storage container are supplied to the rotary tube reactor through a metal tube coupled to a vibrating catalyst particle supply system. The supply system is maintained in an inert gas atmosphere to suppress unwanted reactions. When other materials are added with the catalyst to produce CNT hybrid materials, these other materials can be supplied together with the catalyst, or a separate parallel supply system can be provided for the other materials. The second supply system can be the same as the catalyst supply system, or it can be configured to bring these materials to reaction temperature before supplying them to the reactor. In some embodiments, the catalyst and other materials are pre-blended before being supplied to the reactor in the manner described above for the catalyst and other materials.

[0033] The tubes supplying the catalyst / other materials to the reactor are of sufficient length such that their ends are located inside the rotating tubes in the furnace's preheating zone. In some embodiments, the length of the inner tubes is approximately 1 / 3 to 1 / 6 the length of the rotating tubes in the furnace's high-temperature (reaction) zone. In some embodiments, the diameter of the inner tubes is 1 / 3 to 1 / 2 the diameter of the rotating tubes. In some embodiments, the reactor has multiple heating zones. In some embodiments, the reactor is heated by gas or electricity.

[0034] This arrangement allows the catalyst particles to reach the desired reaction temperature before contact with the reaction gas. The inner tube is made of special corrosion-resistant steel such as Inconel or titanium. The length and diameter of the inner tube relative to the rotating tube are selected to ensure efficient heat transfer during the catalytic process.

[0035] The temperature at the point where the process gas and catalyst particles are in close contact is measured by a thermocouple introduced into a thermowell, indicated by a solid black line in the reactor inlet block. Depending on the type of material being synthesized, a flyer or other mass distribution structure (schematically shown in Figure 1) may be placed in the rotating tube to improve mass and heat transfer between the solid particles and the reaction gas. Flyers can also improve the flow of material within the rotating tube. The residence time of the catalyst in the reactor is controlled by the rotation speed of the tube and its inclination angle.

[0036] The resulting product is separated from the gas at the reactor outlet, for example, using a gas / solid separator 22. A valve system discharges the product into a container (e.g., a purge container 28) with an inert gas injection system to remove ethylene and hydrogen and cool the material before packaging (e.g., in a storage drum 30).

[0037] The liquid condenser 24 is used to remove undesirable reaction by-products before hydrogen separation and recycling of the reaction gases.

[0038] Unreacted ethylene (or other carbon source reaction gases) and hydrogen are subsequently separated using an H2 membrane separator 26, which may contain organic polymers, nanoporous inorganic materials (ceramics, oxides, porous bicore glass, etc.), dense metals (Pd, and metal alloys), and carbon and carbon nanotube-based membranes.

[0039] Next, the unreacted carbon source is recycled by the recycling system 20, and the hydrogen can be used for other catalytic industrial processes or for other purposes such as power generation, heat generation, or transport. The recycled gas may contain ethylene and hydrogen, which promote the production reactions of carbon nanotubes and hybrid materials by improving heat transfer and catalyst activation. The amount of unused ethylene supplied to the reactor depends on the level of ethylene conversion in the production of carbon nanotubes / hybrid materials.

[0040] The gas composition can be detected at several points using a mass spectrometer or other instrument, as shown in Figure 1. Composition data can be used for process control and other purposes, such as recording the gas composition and quality. A controller (not shown in Figure 1) receives the gas composition data (and other variables) and controls valves, heaters, particle feeders, and other process equipment (all not shown in Figure 1) used to maintain desired process conditions.

[0041] The following detailed description of embodiments illustrates, but does not limit, the scope of this disclosure.

[0042] Example 1 The effect of gas-catalyst contact temperature and residence time on the yield of carbon nanotubes.

[0043] To demonstrate the differences between the prior art and the present invention, an FeCoMo / MgO-Al2O3 catalyst prepared according to the prior art (R. Prada Silvy, Y. Tan, U.S. Patent No. 9855551) was used. A series of experiments were conducted to investigate the effects of the contact temperature between the catalyst and the reaction gases (C2H 460%V, H2 10%V, and N2 30%V) and the residence time (minutes) in the rotating tube (results are shown in Table 1).

[0044] In Experiments 1-4, the catalyst was brought into contact with the reaction gas at different temperatures (150, 300, and 500°C), and then the oven was rapidly heated until the reaction temperature (650°C) was reached. In Experiments 1, 3, and 4, the residence time of the catalyst in the rotating tube reactor was 10 minutes, while in Experiment 2 it was 16 minutes. In Experiments 5 and 6, which are representative of the present invention, the catalyst was preheated under a nitrogen stream until the reaction temperature (650°C) was reached, and then brought into contact with the reaction gas for residence times of 6 minutes and 10 minutes, respectively.

[0045] The residence time of the materials in the reactor is a parameter that determines the productivity of the process. Comparing the results obtained in Experiments 2, 3, and 5, similar results are observed in carbon yield (i.e., the proportion of carbon in the product). It is clear that the catalyst, preheated to the reaction temperature, exhibits the same proportion of carbon with a shorter residence time (6 minutes) than the prior art (10 minutes and 16 minutes, respectively). The highest carbon yield is obtained when the catalyst is preheated to 650°C and the residence time is 10 minutes.

[0046] [Table 1]

[0047] Example 2 Reactivity of catalysts at different temperatures

[0048] In another experiment, the effect of reaction temperature was investigated. In this case, the catalyst was exposed to the reaction gas at different temperatures (ranging from 300 to 750°C) for a residence time of 10 minutes. The results are shown in Figure 2. At T ≤ 450°C, no reaction between the catalyst and the carbon source was observed. The carbon yield gradually increased with increasing reaction temperature, reaching a plateau at T ≥ 675°C. Signs of catalyst deactivation were observed at T ≥ 700°C. When catalyst deactivation occurred, the carbon yield decreased, and the diameter of the tube increased due to the sintering of the active metal aggregates.

[0049] Example 3 :

[0050] Another series of experiments were conducted at 675C to investigate how the H2 composition in the reaction gas affects the carbon yield. These results help establish the desired maximum H2 composition in the recycled gas. Figure 3 shows that the carbon yield remains constant up to approximately 30%V of H2, and then gradually decreases as the proportion of H2 in the reaction mixture increases.

[0051] Example 4 Characteristics of CNTs synthesized using prior art and the present invention.

[0052] The diameter and length of the carbon nanotubes were measured using scanning electron microscopy (SEM) analysis. Figures 4 and 5 show SEM images corresponding to Experiment 1 and Experiment 6, respectively, taken at magnifications of 10KX and 100KX. Experiment 6 (Figure 5) shows long MWCNTs (L≧7 microns) with a smaller diameter (11±2 nm) than the CNTs (L=2~3 microns, D=14±2 nm) of the prior art Experiment 1 (Figure 4) (therefore, the L / D ratio is greater than 500).

[0053] Example 5 : Continuous production of multi-walled carbon nanotubes and hydrogen.

[0054] This example demonstrates the production of carbon nanotubes using the system, reactor, and process of the present invention shown in Figure 1. Table 2 shows the amounts of CNTs and H2 produced, as well as the amounts of recycled ethylene and H2, at different catalyst supply rates. The ethylene flow rate at the reactor inlet is 11 L / min. The catalyst residence time in the rotating tube reactor is 10 minutes. The reaction temperature is 675°C, and the carbon yield was 80% under each condition. The H2 composition in the feed gas is 20%V. The catalyst residence time is controlled by the rotation speed and tilt angle of the rotating tube. Increasing the catalyst supply rate to the reactor gradually increases the ethylene consumption and hydrogen production. When the C2H4 / catalyst contact time is 4.6 L / g, higher CNT and hydrogen production rates are obtained, and the recycled C2H4 rate is approximately 20%.

[0055] [Table 2]

[0056] Example 6 : Continuous production of single-walled and double-walled carbon nanotubes from methane.

[0057] This example illustrates the production of SWCNTs and double-walled carbon nanotubes (DWCNTs) from the catalytic decomposition of methane using the system and related processes of the present invention shown in Figure 1.

[0058] Reaction temperature, methane composition in the reaction gas, and catalyst type are important synthetic parameters for the selective production of SWCNTs or DWCNTs. For SWCNT synthesis, the reaction temperature should be 950°C or lower, preferably in the range of 800-900°C. Methane can be diluted with an inert gas such as nitrogen or hydrogen. To selectively produce SWCNTs, the methane composition should be 50%V or lower, preferably 20-30%V.

[0059] In the case of DWCNT synthesis, the reaction temperature is higher than 900°C, preferably in the range of 950 to 1000°C. The methane composition in the reaction gas varies between 25 and 50%V, preferably between 25 and 40%V.

[0060] The types of catalysts used for both SWCNT and DWCNT synthesis include combinations of transition metals (typically Fe, Co, Ni, Mo, etc.) supported on metal oxides such as MgO, Al2O3, TiO2, SiO2, and mixtures thereof. The residence time of the catalyst in the reaction zone for both SWCNT and DWCNT is usually 5 minutes or more.

[0061] An FeMo / MgO catalyst (2% total metal, Fe / Mo atomic ratio = 2) was contacted with a mixed gas CH4+H2 (30% CH4) at a temperature of 975°C and a residence time of 5 minutes in the reactor. The contact time between the methane gas flow and the catalyst was 1.13 L / g per minute of reaction. Table 3 shows the results obtained from the continuous production of DWCNTs. The amount of DWCNT deposited per gram of catalyst, determined from ash content and thermogravimetric analysis, was 0.25 g per gram of catalyst introduced into the reactor. This corresponds to a carbon yield of 20%. The added unused methane was 41%, and the amount of H2 produced for heat, energy, and other industrial uses was 11.2 L / h per gram of catalyst. The selectivity of SWCNTs and DWCNTs in the methane composition reaction depends on the type of catalyst used, the CH4 / H2 composition ratio in the gas supply, and the reaction temperature.

[0062] [Table 3]

[0063] While several aspects of at least one embodiment have been described above, those skilled in the art will understand that various changes, modifications, and improvements are readily possible. Such changes, modifications, and improvements are intended to be part of this disclosure and within the scope of the invention. Accordingly, the foregoing description and drawings are illustrative only, and the scope of the invention should be determined by the proper interpretation of the appended claims and their equivalents.

Claims

1. A reactor system configured to produce a carbon-containing material by exposing catalyst particles to a carbon-containing reaction gas, A reactor containing a heated reaction volume in which the reaction gas is exposed to catalyst particles, A reaction gas inlet port configured to introduce the reaction gas into the reaction volume, It includes at least one catalyst particle inlet configured to introduce catalyst particles into the reaction volume, The catalyst particle inlet includes a duct leading from outside the reactor into the reaction volume, the reactor includes a rotating tube reactor, and the reaction volume is heated to the reaction temperature. A reactor system in which catalyst particles are heated to the reaction temperature before they come into contact with the reaction gas within the reaction volume.

2. The reactor system according to claim 1, wherein the carbon-containing material comprises at least one of a carbon nanotube-containing material, a carbon nanotube hybrid material, and a carbon nanotube.

3. Carbon nanotube hybrid materials include carbon nanotube-carbon black, carbon nanotube-graphite, carbon nanotube-graphene nanoplatelets, carbon nanotube-silicon, carbon nanotube-alumina, carbon nanotube-magnesium oxide, carbon nanotube-silica, carbon nanotube-activated carbon, carbon nanotube-cementaceous material, and carbon nanotube-SiO2. ｘ The reactor system according to claim 2, comprising at least one of the following: carbon nanotube-carbon fiber material.

4. The reactor system according to claim 1, wherein the catalyst particle inlet includes a catalyst supply pipe leading from outside the reactor into the reaction volume, and the catalyst particles are heated to the reaction temperature within the catalyst supply pipe before they exit the catalyst supply pipe and come into contact with the reaction gas.

5. The reactor system according to claim 1, further comprising: a reactor having an outlet for carbon-containing material, unreacted reaction gas, and reaction byproducts generated in the reactor, a gas / solid separator fluidly connected to the reactor outlet and configured to separate the carbon-containing material from the unreacted reaction gas and reaction byproducts, and a gas / liquid separator configured to separate the polymerized carbon compound produced by the thermal decomposition of the carbon source from the unreacted reaction gas and reaction byproducts by condensation.

6. The reactor system according to claim 5, further comprising a gas recycling system configured to return at least a portion of the unreacted reaction gas to the reactor, wherein the gas recycling system comprises a gas separator configured to separate the unreacted reaction gas from the reaction by-products.

7. The reactor system according to claim 6, wherein the reaction byproduct includes hydrogen.

8. The reactor system according to claim 5, further comprising a product container configured to hold a carbon-containing material separated by a gas / solid separator, the product container being washed with an inert gas.

9. The reactor system according to claim 1, wherein the catalyst particle inlet includes a catalyst supply pipe leading from outside the reactor into the reaction volume, the catalyst supply pipe extending along 1 / 6 to 1 / 3 of the length of the reactor.

10. The reactor system according to claim 9, wherein the reactor has a reaction volume diameter, and the catalyst supply tube has a diameter of 1 / 3 to 1 / 2 of the reaction volume diameter.

11. The reactor system according to claim 9, further comprising a catalyst supply system configured to supply a catalyst into a supply pipe and from the supply pipe into a reactor, wherein the catalyst supply system includes a vibrating feeder configured to move the catalyst along and out of the supply pipe at a controllable speed.

12. The reactor system according to claim 11, further comprising: a catalyst holding container configured to be cleaned with an inert gas and to supply the catalyst to a vibrating feeder; a screw feeder configured to supply the catalyst to the holding container at a controllable rate; and a screw feeder supply container configured to be cleaned with an inert gas and to supply the catalyst to the screw feeder.

13. The reactor system according to claim 1, wherein the temperature of the reaction volume is measured through a thermowell.

14. The reactor system according to claim 1, wherein the reaction volume and catalyst are heated to at least 650°C before contact between the reaction volume and the catalyst, and the residence time of the catalyst in the reactor is at least 6 minutes.

15. The reactor system according to claim 1, wherein the hydrogen composition in the reaction gas is a maximum of 30%.

16. The reactor system according to claim 1, wherein the carbon-containing material includes carbon nanotubes (CNTs).

17. The reactor system according to claim 16, wherein the CNT has a length of at least 7 microns.

18. The reactor system according to claim 16, wherein the CNTs have a length-to-diameter ratio of at least 500.

19. The reactor system according to claim 1, wherein both the reaction volume and the catalyst are heated to at least 700°C before contact, and the reaction gas contains ethylene.

20. The reactor system according to claim 1, wherein both the reaction volume and the catalyst are heated to at least 950°C before contact, and the reaction gas contains methane.

21. A method for producing a carbon-containing material by exposing a carbon-containing reaction gas to catalyst particles in a reactor system, wherein the reactor system includes a rotating tube reactor having a heated reaction volume heated to a reaction temperature to expose the reaction gas to catalyst particles, at least one reaction gas inlet port configured to introduce the reaction gas into the reaction volume, and at least one catalyst particle inlet configured to introduce catalyst particles into the reaction volume, The catalyst particle inlet includes a catalyst supply pipe that leads from outside the reactor into the reaction volume. In the method, A method comprising heating catalyst particles to the reaction temperature in a catalyst supply tube before the catalyst particles come into contact with the reaction gas in the reaction volume.

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