Multi-temperature-zone coupled waste plastic and carbon dioxide co-production carbon nanotube device and test method
By constructing a multi-temperature coupling design in a single reactor, the problems of high energy consumption and low product selectivity of waste plastic pyrolysis and CO2 conversion are solved, and efficient carbon nanotube production and CO2 utilization are achieved, achieving maximum carbon recovery and improving catalyst stability.
Patent Information
- Application Number
- CN202510563038.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-30
- Publication Date
- 2025-07-11
AI Technical Summary
In the prior art, waste plastic pyrolytic products have low added value and insufficient conversion efficiency. The production of carbon nanotubes depends on fossil energy and has high energy consumption. CO2 conversion is limited by hydrogen source cost and reaction kinetic barriers. The unoptimized catalyst design leads to product selectivity and low system energy efficiency.
Four functional areas of medium-temperature-high temperature-medium-temperature-high temperature-high temperature are constructed in a single reactor through a gradient induction coil design, so as to achieve efficient coordination of plastic pyrolysis-pyrolysis gas catalytic reforming-reforming gas methanation-methane secondary cracking, and multi-reaction coupling is performed using electromagnetic induction devices and Fe/Ni metal pores.
Significantly reduce energy consumption, improve reaction efficiency, maximize carbon recovery, eliminate the risk of catalyst deactivation, achieve the economic effect of 1+1>2, and build a plastic chemical circulation system with zero carbon emissions.
Smart Images
Figure CN120285934A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of solid waste resource utilization and carbon emission reduction, and particularly to a device for co-producing carbon nanotubes from waste plastics and carbon dioxide. Background Art
[0002] With the acceleration of the global industrialization process, the large-scale application of plastic products and the continuous increase in carbon dioxide (CO2) emissions have become two core environmental problems restricting sustainable development. Against this background, how to achieve the coordinated conversion and high-value utilization of waste carbon resources through technological innovation has become an important research direction in the field of circular economy.
[0003] In the field of traditional waste plastic treatment, pyrolysis has attracted much attention because it can convert high molecular polymers into oil and gas products. However, in the conventional pyrolysis process, the added value of the products is low and the conversion efficiency is insufficient. On the other hand, as a high-value-added nano-carbon material, the industrial production of carbon nanotubes (CNTs) mostly relies on the cracking of fossil fuels, which has problems such as non-renewable raw materials, high process energy consumption, and complex equipment.
[0004] In the field of CO2 conversion, methanation reaction is regarded as one of the key paths to achieve carbon cycle, but its industrialization is limited by the cost of hydrogen source acquisition and reaction kinetics obstacles. Existing technologies mostly rely on electrolyzing water to produce green hydrogen as a reducing agent, but the power consumption and equipment investment cost are high, and the industrial by-product hydrogen has problems of insufficient supply stability.
[0005] The cross-system coupling technology provides a new idea for the coordinated conversion of waste carbon resources. Co-converting the pyrolysis gas of waste plastics and CO2 can construct a carbon closed-loop cycle system. First, the hydrocarbons in the pyrolysis gas can be used as a carbon source to synthesize CNTs, and the by-product hydrogen is used for CO2 reduction. However, the existing research still has the following technical bottlenecks: (1) The coupling degree of multiple reaction systems is insufficient, and the cascade utilization of matter and energy cannot be achieved; (2) The catalyst structure and reactor design are not optimized for complex gas-solid reactions, resulting in low product selectivity and system energy efficiency; (3) There is a lack of systematic research on the matching between the growth mechanism of CNTs and methanation kinetics, making it difficult to ensure process stability.
[0006] The present invention is proposed based on a breakthrough thinking for the above-mentioned technical challenges. By designing a gradient induction coil, four functional regions of medium temperature - high temperature - medium temperature - high temperature are formed in a single reactor, which are respectively used for plastic pyrolysis - catalytic reforming of pyrolysis gas - methanation of reforming gas - secondary cracking of methane, so as to achieve the efficient coordination of multiple reactions. Compared with the traditional reactor system, it can significantly reduce energy consumption, improve reaction efficiency, and for the first time achieve the deep coupling of waste plastics and CO2 at the atomic economy level. This "hydrogen-carbon interlocking" coordination mechanism not only eliminates the risk of catalyst deactivation caused by coke accumulation in the traditional process, but also enables the system carbon recovery rate to reach the theoretical maximum recovery efficiency through the cascade conversion of carbon elements, truly realizing the carbon atom economic effect of 1 + 1 > 2, and providing a paradigm breakthrough for building a zero-carbon plastic chemical recycling system. Summary of the Invention
[0007] In view of the core environmental problems such as the continuous increase in the emissions of waste plastics and carbon dioxide, the present invention constructs a full-chain treatment model for waste plastic pyrolysis - catalytic reforming - methanation - recycling. The cascade conversion of carbon elements can enable the system carbon recovery rate to reach the theoretical maximum recovery efficiency. Based on this, a device for co-producing carbon nanotubes from waste plastics and carbon dioxide with multi-temperature zone coupling is proposed. The device includes: An electromagnetic induction device, a variable-diameter quartz glass tube, a copper crucible, an induction coil, Fe / Ni metal porous, a three-way valve, an upper flange, a lower flange, a feeding device, a carbon dioxide inlet device, an argon inlet device, the upper part of the variable-diameter quartz glass tube, the middle part of the variable-diameter quartz glass tube, the lower part of the variable-diameter quartz glass tube, the feeding port of the three-way valve and the gas inlet of the three-way valve; The electromagnetic induction device is used to generate an alternating electromagnetic field and control the magnetic field intensity by adjusting the power; the variable-diameter quartz glass tube has an upper flange at the upper part connected to the three-way valve, a carbon dioxide inlet at the middle part, and the lower part is connected to the lower flange; the copper crucible is a cylindrical structure with an open upper end, made of copper, and placed above the Fe / Ni metal porous; the induction coil is wound around the outside of the variable-diameter quartz glass tube and is connected to the electromagnetic induction device to receive the alternating electromagnetic field; the Fe / Ni metal porous is composed of a plurality of cylindrical FeNi metal porous foams stacked from top to bottom and is arranged in the variable-diameter quartz glass tube; the feeding device is connected to the variable-diameter quartz glass tube through the feeding port of the three-way valve and is used to convey plastic raw materials into the copper crucible; the carbon dioxide inlet device is connected to the gas inlet at the middle part of the variable-diameter quartz glass tube; the argon inlet device is connected to the variable-diameter quartz glass tube through the gas inlet of the three-way valve.
[0008] Furthermore, the overall variable-diameter quartz glass tube has a variable-diameter structure, and the upper diameter is larger than the lower diameter, and the Fe / Ni metal porous is placed at the variable-diameter part.
[0009] Further, the copper crucible forms a medium-temperature zone through heat transfer of the Fe / Ni metal porous material for plastic pyrolysis.
[0010] Further, the height of the induction coil is the same as the height of the FeNi metal porous material.
[0011] Further, the induction coil is arranged in a gradient manner: the upper part of the induction coil is relatively dense, the middle part is sparse, and it is only connected to the upper and lower dense area coils through a single copper wire, and the lower part is dense; three functional regions of high temperature - medium temperature - high temperature are formed at the Fe / Ni metal porous material through connection with the electromagnetic induction device.
[0012] Further, the Fe / Ni metal porous material has a diameter of 43 mm, a porosity of 0.97, a PPI of not less than 10, and the ratio of Fe:Ni elements is 7:3.
[0013] Further, the three-way valve 6 includes a three-way valve feed port connected to the feeding device; a three-way valve air inlet connected to the argon gas inlet device; and the bottom end of the three-way valve connected to the upper flange inlet.
[0014] Further, the feeding device has a conveying rate of 1 g / min.
[0015] Further, the carbon dioxide inlet device is used for the cooperation of plastic and carbon dioxide.
[0016] According to another aspect of the present invention, a test method for using the above device for co-producing carbon nanotubes from waste plastics and carbon dioxide with multi-temperature zone coupling is provided, including the following steps: S1, Open the argon gas inlet device and introduce an inert gas into the variable-diameter quartz glass tube through the three-way valve connected by a tetrafluoroethylene tube at a rate of 200 ml / min for 30 min to maintain an inert atmosphere for the reaction; S2, Adjust the height of the electromagnetic induction device so that the central height of the electromagnetic induction device is equivalent to the center of the Fe / Ni metal porous material, and at the same time, the induction coil completely wraps the Fe / Ni metal porous material; S3, Turn on the electromagnetic induction device, and the gradient induction coil design will form three regions of high temperature - medium temperature - high temperature from top to bottom in the Fe / Ni metal porous material; the upper high-temperature region transfers heat to the copper crucible, thereby forming four functional regions of medium temperature - high temperature - medium temperature - high temperature; S4, Turn on the feeding device and convey waste plastic particles to the copper crucible in the variable-diameter quartz glass tube at a rate of 1 g / min; S5, The waste plastic is initially pyrolyzed into volatiles in the copper crucible; the volatiles are further catalytically reformed into carbon nanotubes and hydrogen in the upper high-temperature region of the Fe / Ni metal porous material; S6. Open the carbon dioxide inlet device and introduce carbon dioxide into the sparse area in the middle of the induction coil at a rate of 100 ml / min. Methanation reaction occurs between carbon dioxide and the catalytic reforming gas in the middle temperature zone of the Fe / Ni metal porous to produce methane. S7. Methane further cracks in the high temperature zone at the lower part of the Fe / Ni metal porous. S8. After the feeding is completed, collect the gas product through the lower flange outlet and introduce it into a gas chromatograph GC for analyzing the gas product; the prepared carbon nanotubes are attached to the Fe / Ni metal porous and are collected by mechanical vibration separation.
[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention adopts a multi-temperature zone coupling design, and precisely constructs four functional zones of medium temperature - high temperature - medium temperature - high temperature in a single reactor through a gradient induction coil, realizing the efficient coordination of plastic pyrolysis - pyrolysis gas catalytic reforming - reforming gas methanation - methane secondary cracking. The waste heat in the upper high temperature zone is directly conducted to the copper crucible to drive plastic pyrolysis, greatly reducing the energy consumption of traditional electric heating; in the medium temperature zone, the by-product hydrogen and CO2 in the pyrolysis catalytic reforming react to achieve in-situ utilization of energy and substances; in the lower high temperature zone, methane is subjected to secondary cracking, further improving the carbon nanotube yield. This "hydrogen-carbon interlock" coordination mechanism not only eliminates the risk of catalyst deactivation caused by coke accumulation in the traditional process, but also enables the system carbon recovery rate to reach the theoretical maximum recovery efficiency through the cascade conversion of carbon elements, truly realizing the carbon atom economic effect of 1 + 1 > 2. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings: Figure 1 is a schematic structural diagram of a device for co-producing carbon nanotubes from waste plastics and carbon dioxide with multi-temperature zone coupling according to the present invention; Figure 2 is a flow chart of the test method of a device for co-producing carbon nanotubes from waste plastics and carbon dioxide with multi-temperature zone coupling according to the present invention; Wherein: 1 represents an electromagnetic induction device; 2 represents a variable diameter quartz glass tube; 3 represents a copper crucible; 4 represents an induction coil; 5 represents Fe / Ni metal porous; 6 represents a three-way valve; 61 represents the three-way valve feed port; 62 represents the three-way valve gas inlet; 7 represents an upper flange; 8 represents a lower flange; 9 represents a feeding device; 10 represents a carbon dioxide inlet device; 11 represents an argon inlet device; 21 represents the upper part of the variable diameter quartz glass tube; 22 represents the middle part of the variable diameter quartz glass tube; 23 represents the lower part of the variable diameter quartz glass tube. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments may be combined with each other. The described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.
[0020] It should be noted that the descriptions of directions such as "upper part", "middle part", "lower part", "upper end", "middle end", "bottom end", etc. in the present invention are all defined based on the orientation or position relationship shown in the accompanying drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the described structure must be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. In the description of the present invention, the meaning of "a plurality" is more than two, unless otherwise specifically defined.
[0021] In the description of the present invention, unless otherwise clearly specified and limited, the terms "mounted", "connected" and "connected" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.
[0022] Referring to the accompanying drawings to illustrate this embodiment, according to one aspect of the present invention, a device for co-producing carbon nanotubes from waste plastics and carbon dioxide with multi-temperature zone coupling is provided, including: An electromagnetic induction device 1, which can adjust the generated alternating electromagnetic field by adjusting the power.
[0023] A variable-diameter quartz glass tube 2, including a variable-diameter quartz glass tube upper part 21, a variable-diameter quartz glass tube middle part 22, and a variable-diameter quartz glass tube lower part 23; the overall material of the glass tube is quartz, which can withstand a high temperature of 1300 °C and will not react with the products of plastic pyrolysis and catalytic reforming; the overall glass tube is of a variable-diameter structure, and the upper part has a larger diameter than the lower part. This structural design allows the Fe / Ni metal porous body to be directly placed at the variable-diameter part without other additional supports; the outer diameter of the variable-diameter quartz glass tube upper part 21 is 45 mm, and the inner diameter is 43 mm. The outer diameter of the variable-diameter quartz glass tube middle part 22 is 6 mm, the inner diameter is 4 mm, and its maximum vertical distance from the side wall of the variable-diameter quartz glass tube is 30 mm, forming a virtual included angle of 45°. The outer diameter of the lower inlet 23 is 35 mm, and the inner diameter is 33 mm.
[0024] The copper crucible 3 is a cylindrical structure with an open upper end, an inner diameter of 38 mm, and a wall thickness of 1 mm. This structural design can ensure that all the waste plastics transported by the feeding device to the variable-diameter quartz glass tube enter the copper crucible, and at the same time, the 1-mm wall thickness can ensure a good heat transfer rate when the Fe / Ni metal porous transfers heat to the copper crucible.
[0025] The induction coil 4 is closely and evenly wound around the outside of the glass tube. The coil is made of high-purity copper wire, and the outside of the wire is wrapped with insulating material. The cross-sectional area of the coil is reasonably selected according to the heating power and current density, about 100 square millimeters. The total number of winding turns is 14; the induction coil is arranged in a gradient: the upper part of the induction coil is relatively dense, the middle part is sparse, and the lower part is dense. The number of turns in the upper dense area is 4, the number of turns in the middle sparse area is 0, and it is only connected to the upper and lower dense area coils through a copper wire. The number of turns in the lower dense area is 10; the vertical height of the upper dense area is 40 mm, the vertical height of the middle sparse area is 60 mm, and the vertical height of the lower dense area is 100 mm. The total height matches the height of the Fe / Ni metal porous.
[0026] The preparation process of the Fe / Ni metal porous 5 is as follows: A conductive coating is applied to polyurethane foams with different porosities and different PPIs for conductive treatment, and the conductive-treated sponge enters the electroplating process. In the electroplating bath, the metal (iron: nickel = 1:1) is gradually deposited on the surface of the foam through an electric current to form a uniform metal layer; the electroplated foam mold is sintered at high temperature. The purpose of sintering is to remove the polymer material of the mold and leave a metal skeleton structure; the diameter of a single Fe / Ni metal porous is 43 mm, and the height is 10 mm, in which the Fe:Ni element ratio is 7:3.
[0027] The three-way valve 6 includes a three-way valve feed port connected to the feeding device. A three-way valve air inlet connected to the argon gas inlet device. The bottom end of the three-way valve is connected to the upper flange inlet.
[0028] The upper flange 7 is made of stainless steel 316L material and is connected to the upper part 21 of the variable-diameter quartz glass tube through cooperation with a sealing gasket; the sealing gasket is made of high-temperature and corrosion-resistant polytetrafluoroethylene material, which can effectively improve the airtightness of the device; it is installed using high-strength bolts according to the diagonal tightening method, and the bolts are tightened step by step in multiple times. After each tightening, a hexagon torque wrench is used for detection to ensure that the torque of each bolt is uniform and consistent, and the torque deviation is controlled within ±5 N·m.
[0029] The lower flange 8 is made of stainless steel 316L material and is connected to the lower part 23 of the variable-diameter quartz glass tube through cooperation with a sealing gasket.
[0030] The feeding device 9 is connected to the feeding port of the three-way valve and is used to input plastic into the variable-diameter quartz glass tube.
[0031] The carbon dioxide inlet device 10 is connected to the middle inlet of the variable-diameter quartz glass tube and is used to introduce carbon dioxide into the device.
[0032] The argon inlet device 11 is connected to the inlet of the three-way valve and is used to introduce argon into the variable-diameter quartz glass tube.
[0033] In this embodiment, the upper part of the variable-diameter quartz glass tube has a length of 300 mm, and the lower part has a length of 100 mm. The Fe / Ni metal porous is directly placed at the variable diameter, with a height of 200 mm. The middle inlet of the variable-diameter quartz glass tube is arranged 160 mm above the variable diameter, exactly at the upper end of the sparse area in the middle of the induction coil. This arrangement can extend the reaction time of hydrogen and carbon dioxide and the contact time between the gas and the catalyst, and improve the yield of the methanation reaction.
[0034] In this embodiment, the copper crucible is placed at the central position of the Fe / Ni metal porous. The overall material is copper, which has good thermal conductivity and can efficiently and quickly receive the heat from the high-temperature area above the Fe / Ni metal porous, thereby providing the energy required for plastic pyrolysis.
[0035] In this embodiment, the induction coil is tightly and evenly wound around the outside of the glass tube. Inside the glass tube at the same horizontal height is the Fe / Ni metal porous, and at the same time, the height of the coil matches the height of the Fe / Ni metal porous. This arrangement can not only ensure the full utilization of energy and improve the energy utilization efficiency, but also precisely construct three functional regions of high temperature - medium temperature - high temperature inside the Fe / Ni metal porous.
[0036] In this embodiment, the porosity of the Fe / Ni metal porous is 0.97, and the PPI is not less than 10. Specifically, PPI represents the number of pores per square inch. The larger the PPI value, the smaller the pore diameter. The high porosity and high PPI can provide sufficient active sites and contact time for the catalytic reforming of plastic pyrolysis and the methanation reaction, effectively improving the reaction efficiency.
[0037] In this embodiment, the three-way valve is connected to the feeding device at the upper end through a tetrafluoro tube with an outer diameter of 6 mm, to the argon inlet device at the middle end, and to the upper flange inlet at the bottom end.
[0038] In this embodiment, the flow rate of the argon inlet device is 0 - 200 ml / min. It enters the variable-diameter quartz glass tube through the inlet of the three-way valve to provide an inert atmosphere for the device, and at the same time ensures that the gas flows from top to bottom.
[0039] In this embodiment, the outer diameter of the upper flange inlet is 8 mm, the inner diameter is 6 mm, and the height is 80 mm. The upper flange inlet is connected to the bottom end of the three-way valve through a PTFE tube with an outer diameter of 6 mm.
[0040] In this embodiment, the outer diameter of the lower flange outlet is 8 mm, the inner diameter is 6 mm, and the height is 80 mm. It is connected to the gas collection bag through a PTFE tube with an outer diameter of 6 mm to collect the gas products after the reaction.
[0041] In this embodiment, the waste plastic is processed into granular materials with a diameter between 1 - 2 mm and enters the copper crucible through the PTFE tube connected to the upper end of the three-way valve.
[0042] According to another aspect of the present invention, a test method for using the above-mentioned device for co-producing carbon nanotubes from waste plastics and carbon dioxide with multi-temperature zone coupling is provided, including the following steps: S1. Open the argon inlet device and introduce an inert gas into the variable-diameter quartz glass tube 2 through the three-way valve 6 connected to the PTFE tube at a rate of 200 ml / min for 30 min to maintain an inert atmosphere for the reaction. S2. Adjust the height of the electromagnetic induction device 1 so that the central height of the electromagnetic induction device 1 is equivalent to the center of the Fe / Ni metal porous 5, and at the same time, the induction coil 4 completely wraps the Fe / Ni metal porous 5. S3. Turn on the electromagnetic induction device 1. The gradient induction coil design will cause the Fe / Ni metal porous 5 to form three regions of high temperature - medium temperature - high temperature from top to bottom. The upper high-temperature region transfers heat to the copper crucible 3, and then forms four functional regions of medium temperature - high temperature - medium temperature - high temperature. S4. Turn on the feeding device and transport the waste plastic particles to the copper crucible 3 in the variable-diameter quartz glass tube 2 at a rate of 1 g / min. S5. The waste plastic is initially pyrolyzed into volatiles in the copper crucible 3; the volatiles are further catalytically reformed into carbon nanotubes and hydrogen in the upper high-temperature region of the Fe / Ni metal porous 5. S6. Open the carbon dioxide inlet device and introduce carbon dioxide into the sparse region in the middle of the induction coil 4 at a rate of 100 ml / min. The carbon dioxide reacts with the catalytic reforming gas in the middle medium-temperature region of the Fe / Ni metal porous 5 to produce methane through methanation reaction. S7. Methane further undergoes cracking in the lower high-temperature region of the Fe / Ni metal porous 5. S8. After the feeding is completed, collect the gas products through the outlet of the lower flange 8 and introduce them into a gas chromatograph GC to analyze the gas products; the prepared carbon nanotubes adhere to the Fe / Ni metal porous 5 and are separated and collected by mechanical vibration.
[0043] The embodiments of the present invention disclosed above are only used to help illustrate the present invention. The embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described. According to the content of this specification, many modifications and variations can be made. These embodiments are selected and specifically described in this specification to better explain the principles and practical applications of the present invention, so that those skilled in the art can well understand and utilize the present invention.
Claims
1. A device for co-producing carbon nanotubes from waste plastics and carbon dioxide with multi-temperature zone coupling, characterized in that, Including: Electromagnetic induction device (1), variable-diameter quartz glass tube (2), copper crucible (3), induction coil (4), Fe / Ni metal porous (5), three-way valve (6), upper flange (7), lower flange (8), feeding device (9), carbon dioxide inlet device (10), argon inlet device (11), upper part of the variable-diameter quartz glass tube (21), middle part of the variable-diameter quartz glass tube (22), lower part of the variable-diameter quartz glass tube (23), three-way valve feed port (61) and three-way valve air inlet (62); The electromagnetic induction device (1) is used to generate an alternating electromagnetic field and control the magnetic field intensity by adjusting the power. The variable-diameter quartz glass tube (2) has an upper flange (7) provided at the upper part of the variable-diameter quartz glass tube (21) which is connected to the three-way valve (6), a carbon dioxide inlet provided at the middle part of the variable-diameter quartz glass tube (22), and the lower part of the variable-diameter quartz glass tube (23) is connected to the lower flange (8). The copper crucible (3) is of a cylindrical structure with an open upper end, made of copper material, and placed above the Fe / Ni metal porous (5). The induction coil (4) is wound around the outside of the variable-diameter quartz glass tube (2) and is connected to the electromagnetic induction device (1) to receive the alternating electromagnetic field. The Fe / Ni metal porous (5) is composed of multiple cylindrical FeNi metal porous foams stacked from top to bottom and is arranged inside the variable-diameter quartz glass tube (2). The feeding device (9) is connected to the variable-diameter quartz glass tube (2) through the three-way valve feed port (61) and is used to convey plastic raw materials into the copper crucible (3). The carbon dioxide inlet device (10) is connected to the air inlet of the middle part of the variable-diameter quartz glass tube (22). The argon inlet device (11) is connected to the variable-diameter quartz glass tube (2) through the air inlet (62) of the three-way valve.
2. The apparatus for co-producing carbon nanotubes from waste plastics and carbon dioxide with multi-temperature zone coupling according to claim 1, characterized in that The variable-diameter quartz glass tube (2) is of a variable-diameter structure as a whole, and the diameter of the upper part is larger than that of the lower part, and the Fe / Ni metal porous (5) is placed at the variable-diameter part.
3. The apparatus for co-producing carbon nanotubes from waste plastics and carbon dioxide with multi-temperature zone coupling according to claim 1, characterized in that, The copper crucible (3) forms a medium-temperature zone through heat transfer of the Fe / Ni metal porous (5) for plastic pyrolysis.
4. The apparatus for co-producing carbon nanotubes from waste plastics and carbon dioxide with multi-temperature zone coupling according to claim 1, characterized in that, The height of the induction coil (4) is the same as the height of the FeNi metal porous (5).
5. A device for co-producing carbon nanotubes from waste plastics and carbon dioxide with multi-temperature zone coupling according to claim 1, characterized in that The induction coil (4) is arranged in a gradient: the upper part of the induction coil is more dense, the middle part is sparse, and it is only connected to the upper and lower dense area coils through a single copper wire, and the lower part is dense; by connecting with the electromagnetic induction device (1), three functional areas of high temperature - medium temperature - high temperature are formed at the Fe / Ni metal porous (5).
6. The device for co-producing carbon nanotubes from waste plastics and carbon dioxide with multi-temperature zone coupling according to claim 1, wherein The Fe / Ni metal porous (5) has a diameter of 43 mm, a porosity of 0.97, a PPI of not less than 10, and the ratio of Fe:Ni elements is 7:
3.
7. The apparatus for co-producing carbon nanotubes from waste plastics and carbon dioxide with multi-temperature zone coupling according to claim 1, characterized in that, The three-way valve 6 includes a three-way valve feed port (61) connected to the feeding device (9); a three-way valve air inlet (62) connected to the argon inlet device; and the bottom end of the three-way valve is connected to the inlet of the upper flange (7).
8. The apparatus for co-producing carbon nanotubes from waste plastics and carbon dioxide with multi-temperature zone coupling according to claim 1, characterized in that The feeding device (9) has a conveying rate of 1 g / min.
9. The apparatus for co-producing carbon nanotubes from waste plastics and carbon dioxide with multi-temperature zone coupling according to claim 1, wherein The carbon dioxide inlet device (10) is used for the cooperation of plastic and carbon dioxide.
10. A test method for a device for co-producing carbon nanotubes from waste plastics and carbon dioxide using the above-mentioned multi-temperature zone coupling device, characterized in that, The system is a multi-temperature zone coupled waste plastic and carbon dioxide co-production carbon nanotube device according to any one of claims 1 to 9, and the test method includes the following steps: S1. Open the argon inlet device (11), and introduce an inert gas into the variable-diameter quartz glass tube (2) at a rate of 200 ml / min for 30 min through the three-way valve (6) connected to the tetrafluoroethylene tube to maintain an inert atmosphere for the reaction; S2. Adjust the height of the electromagnetic induction device (1) so that the central height of the electromagnetic induction device (1) is equivalent to the center of the Fe / Ni metal porous body (5), and at the same time, the induction coil (4) completely wraps the Fe / Ni metal porous body (5); S3. Turn on the electromagnetic induction device (1). The gradient induction coil design will form three regions of high temperature - medium temperature - high temperature from top to bottom in the Fe / Ni metal porous body (5); the upper high-temperature region transfers heat to the copper crucible (3), and then forms four functional regions of medium temperature - high temperature - medium temperature - high temperature; S4. Turn on the feeding device (9) and convey waste plastic particles to the copper crucible (3) in the variable-diameter quartz glass tube (2) at a rate of 1 g / min; S5. The waste plastic is preliminarily pyrolyzed into volatiles in the copper crucible (3); the volatiles are further catalytically reformed into carbon nanotubes and hydrogen in the upper high-temperature region of the Fe / Ni metal porous body (5); S6. Open the carbon dioxide inlet device (10) and introduce carbon dioxide into the middle sparse region of the induction coil (4) at a rate of 100 ml / min. The carbon dioxide and the catalytic reforming gas undergo a methanation reaction in the middle temperature region of the Fe / Ni metal porous body (5) to generate methane; S7. Methane further undergoes cracking in the lower high-temperature region of the Fe / Ni metal porous body (5); S8. After the feeding is completed, collect the gas product through the outlet of the lower flange (8) and introduce it into a gas chromatograph GC to analyze the gas product; the prepared carbon nanotubes are attached to the Fe / Ni metal porous body (5) and are separated and collected by mechanical vibration.