Device for preparing carbon nano tube by using waste polystyrene plastic

Abstract

The utility model provides a device for preparing a carbon nano tube by using waste polystyrene plastic. The device comprises a cutting mechanism, a crushing mechanism and a preparation device connected to a discharge hole of the crushing mechanism. The cutting mechanism is used for cutting waste polystyrene plastic raw materials, and the smashing mechanism is arranged at the output end of the cutting mechanism. The preparation device comprises a first-stage reaction part and a second-stage reaction part which are arranged up and down, and a condensing device connected to a gas outlet of the second-stage reaction part. The first-stage reaction part comprises a first reaction cavity located in the middle and a first ventilation cavity arranged outside the first reaction cavity. The second-stage reaction part comprises a second reaction cavity positioned in the middle and a second ventilation cavity arranged outside the second reaction cavity. And a connecting pipe is arranged between the first ventilation cavity and the second ventilation cavity. Heating parts are further arranged outside the first ventilation cavity and the second ventilation cavity. According to the utility model, the mutual influence of environments in pyrolysis and catalytic reforming procedures is avoided, and the preparation quality of the carbon nanotubes is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of carbon nanotube preparation, and particularly relates to a device for preparing carbon nanotubes by using waste polystyrene plastics. Background Art

[0002] Carbon nanotubes have a wide range of applications. In terms of electrical properties, carbon nanotubes can be used as transistors and quantum wires, and can also be used to prepare supercapacitors. In catalytic chemistry, carbon nanotubes can be used as catalyst carriers to improve the catalytic efficiency of catalysts.

[0003] There are three existing methods for preparing carbon nanotubes: arc discharge method, laser evaporation method, and chemical vapor deposition method. Among them, the basic process of the chemical vapor deposition method is that when a carbon-containing gas flows through the surface of catalyst particles, it is decomposed, and carbon is deposited to form carbon nanotubes. Carbon undergoes a series of processes such as cracking and diffusion from the carbon precursor to grow into carbon nanotubes, that is, the carbon precursor first undergoes thermal cracking, deposits on the surface of the catalyst particles, then carbon or metal carbide diffuses on the surface of the catalyst particles, and finally carbon grows into carbon nanotubes after recombination.

[0004] In the process of preparing carbon nanotubes, in addition to the type of carbon source having a greater impact on the product characteristics, different thermal cracking conditions, such as reaction time, temperature, heating rate, reaction atmosphere and other elements, result in great differences in the growth and quality of the obtained carbon nanotubes.

[0005] In the prior art, most of the thermal decomposition and catalytic reforming processes of carbon nanotubes are set in a quartz reaction tube. However, due to the different temperature environments required for the thermal decomposition and catalytic reforming processes, the gases evolved during the thermal decomposition of the carbon source material cannot all enter the catalytic section for reforming, resulting in a decrease in the purity of the product gas, and further affecting the carbon deposition obtained in the catalytic reforming section, thereby affecting the quality of carbon nanotubes. Summary of the Utility Model

[0006] In view of this, the utility model aims to provide a device for preparing carbon nanotubes by using waste polypropylene plastics, which can facilitate the preparation of carbon nanotubes, avoid the mutual influence of the environments in the thermal decomposition and catalytic reforming processes, and improve the quality of carbon nanotubes.

[0007] To achieve the above object, the technical solution of the utility model is realized as follows:

[0008] A device for preparing carbon nanotubes by using waste polystyrene plastics includes a cutting mechanism, a crushing mechanism, and a preparation device connected to the discharge port of the crushing mechanism;

[0009] The cutting mechanism is used to cut the waste polystyrene plastic raw material, and the crushing mechanism is arranged at the output end of the cutting mechanism;

[0010] The preparation device includes a first-stage reaction part and a second-stage reaction part arranged vertically, and a condensation device connected to the air outlet of the second-stage reaction part;

[0011] The first-stage reaction part includes a first reaction chamber located in the middle and a first ventilation chamber arranged outside the first reaction chamber;

[0012] The second-stage reaction part includes a second reaction chamber located in the middle and a second ventilation chamber arranged outside the second reaction chamber;

[0013] A connecting pipe is provided between the first ventilation chamber and the second ventilation chamber;

[0014] A heating part is further provided outside the first ventilation chamber and the second ventilation chamber.

[0015] Furthermore, the heating part includes a first heating part arranged outside the first ventilation chamber and a second heating part arranged outside the second ventilation chamber;

[0016] The first heating part and the second heating part are electrically connected to a control system, and the control system adjusts the temperatures of the first reaction chamber and the second reaction chamber.

[0017] Furthermore, temperature sensors are arranged in both the first reaction chamber and the second reaction chamber.

[0018] Furthermore, the first-stage reaction part includes a first-stage reaction tube arranged in the middle, and a top cover and a first plugging plate sealed on both sides of the first-stage reaction tube;

[0019] The first heating part is provided with a receiving cavity, the first heating part is arranged at an interval from the first-stage reaction tube, and the first plugging plate is inserted into the receiving cavity at the lower end of the first heating part;

[0020] The inner cavity of the first-stage reaction tube is formed into a first-stage reaction chamber, and a first ventilation chamber is formed between the first heating part and the first-stage reaction tube.

[0021] Furthermore, the first-stage reaction tube is provided with a first ventilation hole, and the first ventilation hole communicates the first-stage reaction chamber and the first ventilation chamber.

[0022] Furthermore, a funnel for containing raw materials is arranged in the first-stage reaction tube, a receiving plate is arranged below the funnel, and a driving part for driving the funnel to move up and down is arranged above the top cover;

[0023] The bottom plate of the funnel is made of a screening plate, and when the funnel stops moving down quickly, part of the raw materials are scattered on the screening plate;

[0024] The first heating part is used to heat the raw material to the temperature required for the pyrolysis reaction.

[0025] Further, the secondary reaction part includes a secondary reaction tube disposed in the middle. A cavity is provided in the second heating part, and the second heating part and the secondary reaction tube are arranged at intervals.

[0026] The upper and lower ends of the cavity are provided with inserted second plug plates, and the two second plug plates seal the secondary reaction tube in the middle.

[0027] The inner cavity of the secondary reaction tube is formed into a secondary reaction cavity, and a secondary ventilation cavity is formed between the second heating part and the secondary reaction tube.

[0028] Further, the secondary reaction tube is provided with a second ventilation hole, and the second ventilation hole communicates the secondary reaction cavity and the secondary ventilation cavity. The gas after pyrolysis enters the secondary ventilation cavity through the connecting pipe.

[0029] A one-way exhaust valve is provided on the second ventilation hole to prevent the gas in the secondary reaction cavity from entering the secondary ventilation cavity.

[0030] An air outlet pipe communicating with the inlet of the condensation device is provided in the secondary reaction cavity.

[0031] Further, a support plate arranged radially is provided in the inner cavity of the secondary reaction tube. A catalyst part for placing a catalyst is arranged above the support plate. The detection end of the temperature sensor is arranged in the catalyst part. The inlet end of the air outlet pipe is arranged between the upper plane of the support plate and the second plug plate.

[0032] Further, both the first reaction cavity and the second reaction cavity are provided with nitrogen delivery pipes communicating with an external nitrogen tank.

[0033] A steam delivery pipe communicating with an injection pump is provided in the second reaction cavity.

[0034] Compared with the prior art, the present utility model has the following advantages:

[0035] For the device for preparing carbon nanotubes by using waste polystyrene plastics according to the present utility model, a cutting mechanism and a crushing mechanism are provided to cut and then crush the existing plastic waste with waste polystyrene, which is convenient for the uniform mixing and feeding of the raw materials. By arranging the preparation device as an upper and lower arranged primary reaction part and secondary reaction part, in the preparation of carbon nanotubes, the waste polystyrene plastic is placed in the primary reaction part and heated by the heating part for pyrolysis. The gas collected after pyrolysis is input into the secondary reaction part through the connecting pipe, and carbon nanotubes are obtained by heating with the heating part and catalysis of the catalyst, avoiding the mutual influence of the environments in the pyrolysis and catalytic reforming processes and improving the preparation quality of carbon nanotubes. Brief Description of the Drawings

[0036] The drawings forming a part of the present utility model are used to provide a further understanding of the present utility model. The schematic embodiments of the present utility model and their descriptions are used to explain the present utility model and do not constitute an improper limitation to the present utility model. In the drawings:

[0037] Figure 1 It is a schematic structural diagram of the device for preparing carbon nanotubes using waste polystyrene plastics according to the embodiment of the present utility model;

[0038] Figure 2 It is a schematic structural diagram of the cutting mechanism according to the embodiment of the present utility model;

[0039] Figure 3 It is a schematic structural diagram of the preparation device according to the embodiment of the present utility model.

[0040] Description of the reference numerals in the drawings:

[0041] 1. Cutting mechanism; 2. Crushing mechanism; 3. Preparation device; 4. Control system;

[0042] 101. Vertical plate; 102. First cylinder; 103. Push plate; 104. Support rod; 105. End plate; 106. Cutting knife; 107. Second cylinder; 108. Bottom frame; 109. Transmission mechanism;

[0043] 301. Primary reaction part; 302. Secondary reaction part; 303. Condensing device; 304. Connecting pipe; 305. First heating part; 306. Second heating part; 307. Temperature sensor; 308. Air outlet pipe; 309. Nitrogen delivery pipe; 310. Steam delivery pipe;

[0044] 3011. First reaction chamber; 3012. First ventilation chamber; 3013. Primary reaction tube; 3014. Top cover; 3015. First plugging plate; 3016. First ventilation hole; 3017. Funnel; 3018. Receiving plate; 3019. Driving part; 3020. Screening plate;

[0045] 3021. Second reaction chamber; 3022. Second ventilation chamber; 3023. Secondary reaction tube; 3024. Second plugging plate; 3025. Second ventilation hole; 3026. Support plate. Detailed Description of the Preferred Embodiments

[0046] It should be noted that, without conflict, the embodiments in the present utility model and the features in the embodiments may be combined with each other.

[0047] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "back", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present utility model. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0048] In addition, in the description of the present utility model, unless otherwise clearly defined, the terms "installation", "connection", "connection", and "connector" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood in combination with specific situations.

[0049] The present utility model will be described in detail below with reference to the drawings and in combination with embodiments.

[0050] This embodiment relates to a device for preparing carbon nanotubes from waste polystyrene plastics, as Figures 1 to 3 shown. The device includes a cutting mechanism 1, a pulverizing mechanism 2, and a preparation device 3 connected to the discharge port of the pulverizing mechanism 2. The cutting mechanism 1 is used to cut the waste polystyrene plastic raw material, and the pulverizing mechanism 2 is arranged at the output end of the cutting mechanism 1. The preparation device 3 includes a first reaction part 301 and a second reaction part 302 arranged up and down, and a condensation device 303 connected to the gas outlet of the second reaction part 302.

[0051] Among them, the first reaction part 301 includes a first reaction chamber 3011 located in the middle and a first ventilation chamber 3012 arranged outside the first reaction chamber 3011. The second reaction part 302 includes a second reaction chamber 3021 located in the middle and a second ventilation chamber 3022 arranged outside the second reaction chamber 3021. A connecting pipe 304 is provided between the first ventilation chamber 3012 and the second ventilation chamber 3022. Heating parts are also provided outside the first ventilation chamber 3012 and the second ventilation chamber 3022.

[0052] The device for preparing carbon nanotubes from waste polystyrene plastics in this embodiment cuts and then crushes the existing plastic waste with waste polystyrene through the cutting mechanism 1 and the crushing mechanism 2, facilitating the uniform mixing and feeding of raw materials. By arranging the preparation device 3 as a vertically arranged primary reaction part 301 and secondary reaction part 302, in the preparation of carbon nanotubes, the waste polystyrene plastics are placed in the primary reaction part 301 and pyrolyzed by heating through the heating part. The gas collected after pyrolysis is input into the secondary reaction part 302 through the connecting pipe 304, and carbon nanotubes are obtained through heating by the heating part and catalysis by the catalyst, avoiding the mutual influence of the environments in the pyrolysis and catalytic reforming processes and improving the preparation quality of carbon nanotubes.

[0053] Based on the above overall introduction, the device for preparing carbon nanotubes from waste polystyrene plastics in this embodiment, as Figure 1 and Figure 2 shown, the raw materials in this embodiment are common plastic wastes in life, such as disposable plastic milk tea cups, disposable transparent lunch boxes, plastic packaging bags, etc. As Figure 2 shown, the cutting mechanism 1 includes a chassis 108 and a transmission mechanism 109 arranged on the chassis 108. The transmission mechanism 109 uses belt transmission, and its specific structure can refer to the prior art. The transmission mechanism 109 is fixed on the chassis 108 through a connecting plate, and a positioning part for fixing the raw materials is also arranged on the connecting plate.

[0054] As Figure 2 shown, the positioning part includes a vertical plate 101 fixed to the connecting plate, a first cylinder 102 connected to the vertical plate 101, and a push plate 103 connected to the piston rod of the first cylinder 102. A support rod 104 and an end plate 105 are also arranged on the vertical plate 101, and the above-mentioned raw materials are sleeved on the end plate 105 and the support rod 104.

[0055] In addition, as Figure 2 shown, a cutter 106 capable of moving up and down and a second cylinder 107 for driving the movement of the cutter 106 are also arranged on the chassis 108. Through the action of the first cylinder 102 and the second cylinder 107, the collected disposable milk tea cups, lunch boxes or packaging bags can be cut into strips one by one to facilitate crushing. As Figure 1 shown, the crushing mechanism 2 in this embodiment uses a liquid nitrogen crusher in the prior art, which can crush the strip-shaped plastics into small particle flakes to facilitate the uniform mixing of raw materials.

[0056] As Figure 1 and Figure 3As shown in the figure, the heating part includes a first heating part 305 arranged outside the cavity of the first ventilation cavity 3012, and a second heating part 306 arranged outside the second ventilation cavity 3022. The first heating part 305 and the second heating part 306 are electrically connected to the control system 4, and the control system 4 adjusts the temperatures of the first reaction cavity 3011 and the second reaction cavity 3021. The first heating part and the second heating part 306 in this embodiment both adopt electric heating furnaces. By setting two electric heating furnaces to control the pyrolysis reaction and the catalytic reaction respectively, the purpose of accurately controlling the temperature can be achieved, and the quality of carbon nanotube preparation can be guaranteed.

[0057] In order to be able to control the temperature more accurately, temperature sensors 307 are provided in both the first reaction cavity 3011 and the second reaction cavity 3021. The temperature sensor 307 in this embodiment adopts a thermocouple. The control system 4 in this embodiment uses an existing system such as a PLC to control each driving part in the device, and the temperature sensor 307 is signal-connected to the control system 4.

[0058] As Figure 3 shown in the figure, the primary reaction part 301 includes a primary reaction tube 3013 arranged in the middle, and a top cover 3014 and a first plug plate 3015 blocking both sides of the primary reaction tube 3013. The first heating part 305 is provided with a receiving cavity, the first heating part 305 is arranged at an interval from the primary reaction tube 3013, and the first plug plate 3015 is inserted into the receiving cavity at the lower end of the first heating part 305. The inner cavity of the primary reaction tube 3013 is formed into a primary reaction cavity, and a primary ventilation cavity is formed between the first heating part 305 and the primary reaction tube 3013.

[0059] As Figure 3 shown in the figure, the primary reaction tube 3013 is provided with a first ventilation hole 3016, and the first ventilation hole 3016 communicates the primary reaction cavity and the primary ventilation cavity. In this embodiment, a plurality of first ventilation holes 3016 are uniformly arranged in a circular axis in the radial direction of the primary reaction tube 3013. The heat transfer of the first heating part 305 first passes through the first ventilation cavity 3012, and then is transferred to the first reaction cavity 3011. After the crushed waste polystyrene plastic is scattered on the receiving plate 3018, when the temperature reaches, the plastic pyrolyzes, and the pyrolysis gas enters the first ventilation cavity 3012 from the first reaction cavity 3011.

[0060] As Figure 3 shown in the figure, a funnel 3017 for containing raw materials is arranged in the primary reaction tube 3013, a receiving plate 3018 is arranged below the funnel 3017, and a driving part 3019 for driving the funnel 3017 to move up and down is arranged above the top cover 3014. The bottom plate of the funnel 3017 adopts a screening plate 3020, and when the funnel 3017 stops moving down quickly, part of the raw materials are scattered on the screening plate 3020. The first heating part 305 is used to heat the raw materials to the temperature required for the pyrolysis reaction.

[0061] AsFigure 1 As shown in the figure, a raw material inlet is provided above the funnel 3017. This inlet is connected to the raw material outlet of the crushing mechanism 2 and can be fed through a screw conveyor or through a blower. Correspondingly, the following catalysts need to be filled in a corresponding proportion with the raw materials.

[0062] In this embodiment, the driving part 3019 adopts a winch. After the required plastic pyrolysis is completed, the funnel 3017 can be lifted up, quickly lowered, and stopped, and the raw materials can be made to fall on the receiving plate 3018 through vibration. In addition, the raw materials provided in the funnel 3017 will also undergo partial pyrolysis due to the temperature reaching the required level, and the unpyrolyzed plastics play a preheating effect, thereby ensuring sufficient pyrolysis gas.

[0063] In addition, as Figure 3 shown in the figure, the secondary reaction part 302 includes a secondary reaction tube 3023 provided in the middle. A cavity is provided inside the second heating part 306. The second heating part 306 and the secondary reaction tube 3023 are arranged at intervals. Plug-in second plug plates 3024 are provided at the upper and lower ends of the cavity, and the two second plug plates 3024 block the secondary reaction tube 3023 in the middle. The inner cavity of the secondary reaction tube 3023 is formed into a secondary reaction cavity, and a secondary ventilation cavity is formed between the second heating part 306 and the secondary reaction tube 3023.

[0064] As Figure 3 shown in the figure, the secondary reaction tube 3023 is provided with a second vent hole 3025. The second vent hole 3025 communicates the secondary reaction cavity and the secondary ventilation cavity. The pyrolyzed gas enters the secondary ventilation cavity through the connecting pipe 304. A one-way exhaust valve is provided on the second vent hole 3025 to prevent the gas in the secondary reaction cavity from entering the secondary ventilation cavity. An air outlet pipe 308 communicating with the inlet of the condensation device 303 is provided in the secondary reaction cavity.

[0065] In this embodiment, the second vent holes 3025 are a plurality of through holes evenly distributed in a circumferential manner on the secondary reaction tube 3023. The carbon precursor first undergoes thermal cracking in the first reaction tube, then is catalyzed by the catalyst particles in the secondary reaction tube 3023, and then carbon or metal carbide diffuses on the surface of the catalyst particles. Finally, it enters the condensation device 303 through the air outlet pipe 308, so that carbon undergoes reorganized growth.

[0066] As Figure 3 shown in the figure, the inner cavity of the secondary reaction tube 3023 is provided with a support plate 3026 arranged radially. Above the support plate 3026, a catalyst part for placing the catalyst is provided. The detection end of the temperature sensor 307 is arranged at the catalyst part. The inlet end of the air outlet pipe 308 is arranged between the upper plane of the support plate 3026 and the second plug plate 3024. By plugging the second plug plate 3024 on the electric heating furnace, it is convenient to disassemble the secondary reaction tube 3023, thereby facilitating the addition or replacement of the catalyst.

[0067] The condensation device 303 of this embodiment adopts a two-stage ice-water condensation system to achieve rapid cooling. Preferably, nitrogen delivery pipes 309 communicating with an external nitrogen tank are provided in both the first reaction chamber 3011 and the second reaction chamber 3021. The input of nitrogen can pre-cool the reaction gas and reduce the energy consumption of the subsequent condensation device 303. In addition, a water vapor delivery pipe 310 communicating with an injection pump is provided in the second reaction chamber 3021.

[0068] Taking the catalyst Ni / ZSM5-30 as an example for research, by adding water vapor to provide a water vapor atmosphere in the catalytic reforming stage, the catalyst can be completely reduced by reducing gases such as H2 , CO, etc. to elemental nickel with stronger catalytic activity, without the need for an additional catalyst reduction pretreatment step before the reaction, simplifying the reaction process and making the process of preparing hydrogen from waste plastics more economical.

[0069] The preparation process of the device for preparing carbon nanotubes from waste polystyrene plastics is as follows:

[0070] Prepare raw materials. The experimental raw materials are common plastic wastes in life, collected from vegetable markets and supermarkets in Wuhan area, including disposable plastic milk tea cups, disposable transparent lunch boxes, and plastic packaging bags. These plastic products are first cut into strips with a length of about 2 - 5 cm and a width of 1 - 2 cm using a cutting device, and then pulverized into small particle flakes using a liquid nitrogen pulverizer for uniform mixing and feeding of the raw materials. The elemental analysis results of the mixed plastics show that the contents of C, H, O, and S are 84.51, 13.85, 1.51, and 0.13 wt.%, respectively. The industrial analysis shows that the ash content is less than 1 wt.%.

[0071] Prepare catalysts. The preparation methods of both single-metal catalysts and bimetallic catalysts are impregnation methods. The nickel source and iron source are both hydrated nitrate compounds of their metals, and the catalyst carriers are two types of alumina powders stable at high temperatures, γ-Al2O3 and α-Al2O3 . Taking the Ni / γ-Al2O3 catalyst preparation as an example, 5.503 g of Ni(NO3)3.6H2O is dissolved in 30 ml of ethanol solution. After complete dissolution, 10 g of γ-Al2O3 powder is added and placed on a magnetic stirrer and stirred continuously at a temperature of 50 ºC. After 4 h, most of the ethanol has evaporated and the mixture is in a slurry state. The mixture is placed in an oven and dried at 50 ºC overnight to remove the remaining ethanol. The obtained catalyst precursor is placed in a muffle furnace at 10 ºC min-1The temperature was raised to 800 °C at a heating rate and calcined in an air atmosphere for 3 h. The particle size of the obtained catalyst powder was between 0.05 and 0.18 mm. The metal loading of the catalyst was 10 wt.%. The catalyst was not subjected to a special reduction treatment before the experiment because the H2 and CO generated during the reaction could reduce it in situ.

[0072] Plastic raw materials and the catalyst were weighed in a ratio of 2:1 and placed at the corresponding positions in the primary reaction section 301 and the secondary reaction section 302. Inert gas nitrogen was introduced as a carrier, and the gas flow rate was 110 ml / min. After detecting the airtightness of the reaction system, the pyrolysis section was heated at a heating rate of 40 °C / min, and the final temperature was set to 500 °C and maintained stable.

[0073] After the plastic raw materials reacted in the first reaction chamber 3011, they passed through the first ventilation chamber 3012, entered the second ventilation chamber 3022 through the connecting pipe 304, and then entered the first reaction chamber 3011 again, raising the catalytic section temperature to 800 °C. After the catalytic temperature was stable, the temperature of the thermal stage was raised at a rate of 10 °C / min, and the final temperature was 500 °C and held for 15 min. The product gas was then condensed in the condensation section and collected by a 25 L gas bag. To provide a steam atmosphere, water was injected into the second-stage reforming section at a rate of 6 ml / h through an automatic injection pump, and the reaction time for each group was 30 min.

[0074] Continue to pass nitrogen until the reaction tube cools to room temperature, and then weigh the mass of the catalytic section to obtain the carbon deposition yield. The liquid yield was calculated from the mass difference of the condensation system before and after the reaction. The mass balance of the experiment was obtained from the ratio of the sum of the gas, liquid, and solid yields to the mass of the raw materials. After the plastic pyrolysis, the remaining mass in the first stage was less than 0.001 g, which means that almost all the plastics were completely converted into volatile components and entered the reforming section after pyrolysis. Therefore, the remaining coke content of the raw material pyrolysis was ignored here.

[0075] The device for preparing carbon nanotubes from waste polystyrene plastics in this embodiment converts waste plastics into hydrogen-rich gas through catalytic pyrolysis, transforms the generally considered undesirable carbon deposition into high-quality carbon materials, can greatly utilize the carbon and hydrogen elements in the waste plastic raw materials, and maximizes the utilization of waste materials.

[0076] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A device for preparing carbon nanotubes using waste polystyrene plastics, characterized in that: It comprises a cutting mechanism (1), a crushing mechanism (2), and a preparation device (3) connected to the discharge port of the crushing mechanism (2); The cutting mechanism (1) is used to cut waste polystyrene plastic raw materials, and the crushing mechanism (2) is arranged at the output end of the cutting mechanism (1); The preparation device (3) comprises a primary reaction part (301) and a secondary reaction part (302) arranged vertically, and a condensing device (303) connected to the gas outlet of the secondary reaction part (302); The primary reaction part (301) comprises a first reaction chamber (3011) located in the middle, and a first ventilation chamber (3012) provided outside the first reaction chamber (3011); The secondary reaction part (302) comprises a second reaction chamber (3021) located in the middle, and a second ventilation chamber (3022) arranged outside the second reaction chamber (3021); A connecting pipe (304) is provided between the first ventilation cavity (3012) and the second ventilation cavity (3022); A heating portion is also provided outside the first ventilation cavity (3012) and the second ventilation cavity (3022).

2. The device for preparing carbon nanotubes using waste polystyrene plastic according to claim 1, characterized in that: The heating portion comprises a first heating portion (305) arranged outside the first ventilation cavity (3012), and a second heating portion (306) arranged outside the second ventilation cavity (3022); The first heating part (305) and the second heating part (306) are electrically connected to a control system (4), and the control system (4) adjusts the temperature of the first reaction chamber (3011) and the second reaction chamber (3021).

3. The device for preparing carbon nanotubes using waste polystyrene plastic according to claim 2, characterized in that: Temperature sensors (307) are provided in both the first reaction chamber (3011) and the second reaction chamber (3021).

4. The device for preparing carbon nanotubes using waste polystyrene plastic according to claim 3, characterized in that: The primary reaction part (301) comprises a primary reaction tube (3013) arranged in the middle, and a top cover (3014) and a first blocking plate (3015) blocking both sides of the primary reaction tube (3013); A containing cavity is provided in the first heating part (305), the first heating part (305) and the first-stage reaction tube (3013) are arranged at a distance, and the first blocking plate (3015) is inserted into the containing cavity at the lower end of the first heating part (305); The inner cavity of the primary reaction tube (3013) is formed as a primary reaction chamber, and a primary ventilation chamber is formed between the first heating portion (305) and the primary reaction tube (3013).

5. The device for preparing carbon nanotubes from waste polystyrene plastic according to claim 4, characterized in that: The first-level reaction tube (3013) is provided with a first air hole (3016), and the first air hole (3016) is connected with the first-level reaction chamber and the first-level ventilation chamber.

6. The device for preparing carbon nanotubes using waste polystyrene plastic according to claim 4, characterized in that: A funnel (3017) for containing raw materials is provided in the first-stage reaction tube (3013), a receiving plate (3018) is provided below the funnel (3017), and a driving unit (3019) for driving the funnel (3017) to move up and down is provided above the top cover (3014); The bottom plate of the funnel (3017) is a screening plate (3020), and the funnel (3017) stops moving downward rapidly, causing part of the raw material to scatter on the screening plate (3020); The first heating part (305) is used to heat the raw material to a temperature required for a pyrolysis reaction.

7. The device for preparing carbon nanotubes using waste polystyrene plastic according to claim 3, characterized in that: The secondary reaction part (302) comprises a secondary reaction tube (3023) arranged in the middle, a cavity is arranged in the second heating part (306), and the second heating part (306) and the secondary reaction tube (3023) are arranged at a distance. The upper and lower ends of the cavity are provided with plugged second blocking plates (3024), and the two second blocking plates (3024) block the secondary reaction tube (3023) in the middle; The inner cavity of the secondary reaction tube (3023) is formed as a secondary reaction cavity, and a secondary ventilation cavity is formed between the second heating portion (306) and the secondary reaction tube (3023).

8. The device for preparing carbon nanotubes using waste polystyrene plastic according to claim 7, characterized in that: The secondary reaction tube (3023) is provided with a second air hole (3025), the second air hole (3025) communicating with the secondary reaction chamber and the secondary ventilation chamber, and the pyrolyzed gas enters the secondary ventilation chamber via the connecting tube (304); A one-way exhaust valve is provided on the second air hole (3025) to prevent the gas in the secondary reaction chamber from entering the secondary ventilation chamber; An air outlet pipe (308) communicating with the inlet of the condensing device (303) is provided in the secondary reaction chamber.

9. The device for preparing carbon nanotubes using waste polystyrene plastic according to claim 8, characterized in that: The inner cavity of the secondary reaction tube (3023) is provided with a support plate (3026) arranged in a radial direction, a catalyst portion for placing a catalyst is provided above the support plate (3026), a detection end of the temperature sensor (307) is provided at the catalyst portion, and an inlet end of the gas outlet pipe (308) is provided between the upper plane of the support plate (3026) and the second blocking plate (3024).

10. The device for preparing carbon nanotubes using waste polystyrene plastic according to claim 1, characterized in that: The first reaction chamber (3011) and the second reaction chamber (3021) are both provided with a nitrogen delivery pipe (309) connected to an external nitrogen tank; A water vapor delivery pipe (310) connected to the injection pump is provided in the second reaction chamber (3021).

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