WO2021147531A1 - 一种制备碳纳米管和氢气的方法和装置 - Google Patents

一种制备碳纳米管和氢气的方法和装置 Download PDF

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WO2021147531A1
WO2021147531A1 PCT/CN2020/134160 CN2020134160W WO2021147531A1 WO 2021147531 A1 WO2021147531 A1 WO 2021147531A1 CN 2020134160 W CN2020134160 W CN 2020134160W WO 2021147531 A1 WO2021147531 A1 WO 2021147531A1
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reactor
carbon nanotubes
catalyst
carbon
gas
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PCT/CN2020/134160
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English (en)
French (fr)
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李岩
耿磊
吕振华
李龙利
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山东晶石大展纳米科技有限公司
山东大展纳米材料有限公司
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Priority to US17/793,719 priority Critical patent/US20230348264A1/en
Priority to EP20915656.1A priority patent/EP4095095A1/en
Priority to KR1020227026858A priority patent/KR20220129012A/ko
Publication of WO2021147531A1 publication Critical patent/WO2021147531A1/zh

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Definitions

  • the invention relates to a device and method for preparing carbon nanotubes and hydrogen, in particular to a process method and device for preparing carbon nanotubes and hydrogen by stacking a catalyst in a reactor equipped with a discharging device through vapor deposition reaction.
  • Carbon nanotubes have very excellent physical and mechanical properties.
  • the microstructure of carbon nanotubes can be regarded as a seamless hollow tube formed by curling graphite sheets. It has a large aspect ratio, usually between 1-100nm in diameter. , The length is from a few microns to hundreds of microns.
  • Carbon nanotubes have excellent mechanical and electrical properties. Its hardness is equivalent to that of diamond, and its Young's modulus is about 1.8 TPa; its tensile strength is about 200 GPa, which is 100 times higher than that of steel, but its weight is only 1 of the latter. /6 to 1/7. At the same time, the elastic strain of carbon nanotubes can reach up to about 12%, and they have good flexibility like springs.
  • carbon nanotubes can reach 10,000 times that of copper, and the thermal conductivity is also very good. Because of their excellent performance, carbon nanotubes have broad application prospects in many fields such as nanoelectronic devices, catalyst supports, electrochemical materials, composite materials and so on.
  • the production of carbon nanotubes is a prerequisite for the application of carbon nanotube technology, and it is also a bottleneck restricting the industrialization of this technology.
  • Industrial batch production of carbon nanotubes At present, the electric arc method is used to prepare single-walled carbon nanotubes and the CVD method is used to prepare multi-walled carbon nanotubes.
  • the CVD method mostly uses fluidized bed, fixed bed, and moving bed.
  • the carbon sources used in carbon nanotubes are mainly low-carbon alkanes, alkenes, alcohols, etc., and carbon sources with larger molecular weights such as cyclohexane, benzene, and phenanthrene can also be used.
  • low-carbon hydrocarbons such as methane, propane, ethylene, etc.
  • methane is used as a carbon source.
  • the traditional fixed bed can solve the problem of rapid carbon deposition and deactivation of the catalyst to a certain extent, the fixed bed usually adopts the form of spreading a small amount of catalyst in a porcelain boat.
  • the prior art still needs to develop a method and device for preparing carbon nanotubes and hydrogen by CVD reaction using low-carbon hydrocarbons as a carbon source.
  • the device should have a simple structure, low cost, and improve the utilization rate of catalysts and raw materials.
  • the advantages By adopting the method and device, carbon nanotubes can be prepared at a high rate, with large output, high productivity, high utilization rate of carbon sources, and stable product quality, which is suitable for industrialized large-scale production.
  • the purpose of the present invention is to provide a method and device for continuous production of carbon nanotubes and hydrogen.
  • the device has the advantages of simple structure, low cost, easy operation, and high raw material utilization rate, and can be produced in large quantities at one time.
  • Purity carbon nanotubes are suitable for industrialized large-scale production.
  • a method for continuously preparing carbon nanotubes and hydrogen comprising:
  • step (d) Feeding the catalyst obtained in step (b) or the catalyst supported on carbon nanotubes into the reactor;
  • the carrier is carbon nanotubes or carbon black.
  • the method for pretreating the catalyst precursor on the support is selected from the group consisting of precipitation method, dipping method, sol-gel method, melting method or thermal decomposition method.
  • the step of pretreating the catalyst precursor on the carbon nanotube carrier includes using an active metal salt solution to impregnate the carbon nanotube carrier, and then performing precipitation, drying, and roasting.
  • the height of the carbon nanotube stacked bed added in advance is 1/5-4/5 of the reactor height, preferably 1/2-4/5, from Calculated from the bottom of the reactor.
  • the carbon nanotubes are directly energized and heated, and optionally, resistance wire heating, graphite electrode heating, silicon molybdenum rod heating, or a combination thereof is used for auxiliary heating.
  • step (e) a specific proportion of carbon eradicating gas is continuously or intermittently introduced, and the carbon eradicating gas is carbon dioxide, oxygen, water vapor or a combination thereof, preferably carbon dioxide.
  • the volume ratio of the carbon elimination gas to the carbon source gas is 0.02-0.3:1, preferably 0.04-0.15:1.
  • a mixed gas of carbon source gas and carrier gas is introduced into the reactor, and the carrier gas is selected from nitrogen, argon and hydrogen.
  • the volume ratio to the carbon source gas is 0.2-10:1, preferably 1-5:1.
  • the carbon source gas is a hydrocarbon having 6 carbon atoms or less, preferably methane, propane, ethylene, and more preferably methane and propane.
  • Another aspect of the present invention provides a device for continuously preparing carbon nanotubes and hydrogen, the device comprising:
  • a main reactor for CVD reaction the main reactor has a catalyst feed port, a gas inlet, a reaction material outlet, and a gas outlet; a stirring system and a heating temperature control system are set in the reaction zone of the main reactor ;
  • a catalyst storage tank which is arranged above the main reactor and is connected to the main reactor through a catalyst feed port;
  • a discharging device the discharging device is arranged at the bottom of the main reactor, and the carbon nanotube product is discharged out of the reactor through the reaction material outlet;
  • the gas inlet is located at the bottom of the main reactor, and the gas outlet is located at the top of the main reactor for discharging reaction tail gas and hydrogen.
  • the gas inlet is located below the discharging device.
  • the gas inlet is integrated on the discharge device.
  • the discharging device is a tower grate, a flap grate or a star-shaped discharging device.
  • the device further includes a catalyst feeder and distributor arranged at the catalyst feed port of the main reactor.
  • the device further includes a pressure lock device arranged at the catalyst feed inlet and a pressure lock device arranged at the product outlet.
  • the device further includes a filter provided in front of the air outlet.
  • the device further includes a material height display system arranged in the reaction zone of the main reactor.
  • the gas velocity of the gas in the reactor is 0.02-10 m/s, preferably 0.05-3 m/s, more preferably 0.05-1 m/s.
  • the reaction temperature is set to 500°C to 1100°C, preferably 650°C to 900°C, more preferably 700°C to 850°C;
  • the preheating temperature of the protective gas is 550°C to 1100°C, preferably 650°C-900°C;
  • the preheating temperature of the carbon source gas is 500°C-800°C, preferably 650°C-800°C.
  • the pre-reduction temperature of the catalyst precursor is 450°C-650°C, and the volume ratio of the carrier gas to the carbon source gas is 0.2-10:1, preferably 1-5:1.
  • Figure 1 is a schematic diagram of a reaction device using a five-layer tower grate as a discharging device in an embodiment of the present invention
  • FIG. 2 is a schematic diagram of a reaction device using a three-layer tower grate as a discharging device in another embodiment of the present invention
  • Figure 3 is a schematic diagram of a reaction device using a flap grate as a discharging device in another embodiment of the present invention
  • Figure 4 is a schematic diagram of a five-layer tower grate used in a preferred embodiment of the present invention.
  • FIG. 5 is a schematic diagram of a flap valve used in a preferred embodiment of the present invention.
  • 6-9 are respectively SEM pictures of carbon nanotubes prepared in Example 1 to Example 4 of the present invention.
  • carbon nanotubes and hydrogen can be continuously prepared, and the growth rate of the prepared carbon nanotubes can reach more than 120 times, and the purity is ⁇ 99%.
  • the catalyst precursor used to prepare carbon nanotubes can be carried out by methods known in the art, for example, precipitation method, dipping method, sol-gel method, melting method, thermal decomposition method, etc., preferably using active metal salt solution to carry out the support. Impregnation treatment, then precipitation, drying and roasting.
  • the pretreatment of the catalyst precursor on the carrier can be done by impregnation method, gel method, etc.
  • the impregnation method can adopt the active metal salt solution to impregnate the carrier and then precipitate it with a precipitation agent, and then undergo drying, roasting and other treatments to prepare the carbon nanotube catalyst mixture precursor.
  • the precipitating agent can be ammonia, sodium hydroxide aqueous solution, ammonium carbonate solution, and the like.
  • the gel method includes mixing the active metal salt solution and citric acid into the carrier, heating the reaction and distilling water to a specific solution density and viscosity, then stopping the reaction, and then drying and roasting.
  • the carrier may be carbon nanotubes, carbon black, etc., preferably carbon nanotubes.
  • the step of pre-reducing the catalyst precursor or the catalyst precursor supported on the carbon nanotubes can be carried out in advance outside the reactor, or carried out inside the reactor using hydrogen in the reactor.
  • the carbon nanotube catalyst precursor mixture is pre-reduced, which effectively maintains the designed size of the active site of the catalyst, and minimizes the coalescence and maturation effects of the metal particles to the greatest extent, so that the grown carbon nanotubes have a narrow distribution.
  • (c) reactor was added a pre-stacked carbon nanotubes as a height of the bed, in the presence of a protective gas, carbon nanotubes conduction heating to a temperature CVD reaction
  • a certain height of pure carbon nanotubes is preliminarily added to the reactor as a support for the catalyst. Because carbon nanotubes are loose and special materials with gas channels inside, they can be used as a stacked bed to support catalysts. Due to the small particle size and high density of the catalyst, after adding the catalyst or the catalyst supported on the carbon nanotubes into the reactor, the catalyst will be mixed into the pores of the carbon nanotube stacked bed under the action of agitation and gravity to realize the effect of the carbon nanotubes on the catalyst. The second dispersion.
  • the catalyst can achieve better heat transfer and contact with the carbon source, and improve the heat and mass transfer efficiency;
  • the catalyst In the fluidized bed, due to the large fluidization gas velocity, the catalyst is rapidly deactivated, while in the case of a stacked bed, a small gas velocity can be used for continuous growth without catalytic deactivation.
  • a small gas velocity can be used for continuous growth without catalytic deactivation.
  • the use of stacked bed for reaction is the best way to achieve stable quality and maximize productivity.
  • the height of the carbon nanotube stacked bed added in advance is 1/5-4/5 of the reactor height, preferably 1/2-4/5, calculated from the bottom of the reactor.
  • the bed layer is too low, a small amount of carbon tubes are not enough to fully support and disperse the catalyst; when the bed layer is too high, the growth space of the catalyst is limited, and it cannot make effective contact with the carbon source in time.
  • the carbon nanotube bed is a conductive medium that is heated by electricity, and if the amount is too small, it is not enough to provide sufficient heat.
  • a material height monitoring device is arranged in the reactor, which can monitor the material position in real time, and can understand the material height in the reactor in real time, which is convenient for fine automatic operation.
  • the stability of the reaction can be fed back, and the parameters can be adjusted in time to adjust the addition of the catalyst and the discharge of the material.
  • the term "protective gas” refers to a gas that does not interfere with the reaction between the carbon source and the catalyst.
  • Non-limiting examples include nitrogen, helium, argon, etc. or their mixtures.
  • the carbon nanotubes can be directly energized and heated so that the reactor can reach the CVD reaction temperature.
  • the heating process can also be performed by external heating or the carbon nanotubes can be energized to generate heat and externally heated at the same time.
  • the reaction heating mode may be directly heating the carbon tube, preferably a heating mode in which an electrode is used to directly energize the carbon tube.
  • the auxiliary heating can also be performed in the form of resistance wire heating, graphite electrode heating, silicon molybdenum rod heating, external gas firepower heating, and the like.
  • the pre-reduced catalyst or carbon nanotube-supported catalyst is stored in a catalyst storage tank.
  • the catalyst storage tank is set above the main reactor and is connected to the main reactor through a catalyst inlet.
  • the catalyst in the storage tank enters the main reactor through the catalyst inlet. reactor.
  • the pre-reduced catalyst or carbon nanotube-supported catalyst is added to the reactor through a catalyst feed and a cloth distributor.
  • the catalyst feed and distributor is a device for secondary dispersion of the catalyst materials fed to the reactor.
  • the device is an annular clock-like disc with a scraper on the upper part and multiple locations on the bottom. Grooved container with ring holes. After the catalyst continues to fall on a certain position of the disc, the scraper rotates quickly to uniformly scrape the catalyst through the circular holes onto the carbon nanotube bed below, so that the catalyst is evenly dispersed into the carbon nanotube bed below without accumulation Together.
  • the reaction zone in the main reactor of the present invention is provided with a stirring system.
  • the stirring system can be an integrated stirring system from the top to the bottom of the reactor, or two independent stirring systems can be set at the top and bottom of the reactor.
  • the two sets of mixing systems can be set to intermittent opening mode or continuous opening mode, which is more flexible and flexible.
  • the stirring device can mix the materials uniformly and eliminate possible gas channeling and agglomeration of reaction materials.
  • the stirring system is in the form of frame scraping, multiple blades, preferably frame scraping.
  • the mixing system is in the form of frame scraping, multiple blades, preferably frame scraping.
  • the carbon source gas enters the main reactor through the gas inlet at the bottom of the main reactor.
  • the carbon source gas used in the method of the present invention is a hydrocarbon having 6 carbon atoms or less, preferably methane, propane, ethylene, and more preferably methane and propane.
  • a mixed gas of carbon source gas and carrier gas can be introduced.
  • the carrier gas includes but is not limited to nitrogen, argon and hydrogen, and the volume ratio of the carrier gas to the carbon source gas is 0.2-10:1, preferably 1-5:1.
  • the carrier gas is nitrogen or argon, it plays the role of inert protection and diluting the concentration of the carbon source gas.
  • the carrier gas is hydrogen
  • hydrogen can control the concentration of the carbon source gas and the amorphous carbon produced in the etching reaction. To the dilution effect.
  • the carbon source gas and the carrier gas can be introduced in the form of a mixed gas, or a certain volume of the carbon source gas and the carrier gas can be introduced successively.
  • the volume ratio of the carrier gas to the carbon source gas is 0.2-10:1, preferably 1-5:1.
  • a specific proportion of carbon-eliminating gas is continuously or intermittently introduced, and the carbon-eliminating gas is carbon dioxide, oxygen, water vapor or a combination thereof, preferably carbon dioxide.
  • the volume ratio of carbon elimination gas to carbon source gas is 0.02-0.3:1, preferably 0.04-0.15:1.
  • the stacked bed of carbon nanotube particles is matched with a specific ratio of carbon-eliminating gas mixed in the reaction gas, which solves the problem of carbon-coated deactivation of the catalyst when methane is used as the carbon source, and can realize the preparation of carbon nanotubes with high carbon source utilization. And hydrogen.
  • the discharging device is set at the bottom of the main reactor to keep the carbon nanotube bed at a certain material level, for example, to keep the material level at 1/5-4/5 of the reactor height, preferably 1/2-4/5, from the reaction Starting from the bottom of the reactor, part of the carbon nanotube product is discharged out of the reactor through the discharging device.
  • the reaction tail gas and hydrogen exit the reactor through the gas outlet located at the top of the main reactor.
  • the method for continuously preparing carbon nanotubes using the reaction device of the present invention includes the following specific steps:
  • the gas velocity of the gas in the reactor is 0.05-1 m/s.
  • the reaction temperature is set to 700°C to 850°C; the preheating temperature of the protective gas is 650°C to 900°C; and the preheating temperature of the carbon source gas is 650°C to 800°C.
  • the pre-reduction temperature of the catalyst precursor is 450°C-650°C, and the ratio of the carrier gas to the carbon source gas is 0.2-10:1, preferably 1-5:1.
  • the main reactor refers to a reactor suitable for preparing carbon nanotubes by CVD reaction using a catalyst to catalyze and crack a carbon source.
  • a suitable temperature for example, 500-1100°C, preferably 650-1100°C.
  • the carbon source grows carbon nanotubes on the catalyst support under the action of the catalyst.
  • the reactor can be a stacked bed reactor with a stirring system at the top or bottom and pressure locks at the feed and discharge points to achieve high-pressure operation.
  • the length-to-diameter ratio of the height to the diameter of the reactor is 2-25:1, preferably 3-10:1, more preferably 3-6:1.
  • the "stacked bed” reactor refers to a reactor with a carbon nanotube bed reaction zone pre-stacked to a certain height, the catalyst is uniformly dispersed in the pores of the carbon nanotube stacked bed, and the carbon source gas undergoes CVD under the action of the catalyst The reaction generates new carbon nanotubes.
  • the reactor applicable to the present invention, as long as it can provide a reaction zone for the carbon nanotube stacked bed for CVD reaction.
  • the reactor is a stainless steel reactor lined with a high temperature resistant insulating layer, a metal reactor, a quartz tube reactor, a barrel-shaped and kiln-shaped reactor surrounded by high-temperature resistant materials, or a combination thereof, preferably Stainless steel reactor lined with high temperature resistant insulation layer.
  • the main reactor of the present invention has a catalyst inlet, a gas inlet, a reaction material outlet and a gas outlet.
  • the carbon source gas, the shielding gas and the carrier enter the main reactor through the gas inlet at the bottom of the main reactor.
  • the gas inlet may be arranged below the discharging device, or may be arranged above the discharging device, or integrated on the discharging device, and integrated with the discharging device.
  • the gas inlet is integrated in the discharging device. On the discharge device.
  • the gas outlet is arranged at the upper part of the main reactor, and the main reactor further includes a filter arranged in front of the gas outlet.
  • the filter is a filter with micron-level pores made of high-mesh high-temperature stainless steel powder to achieve gas-solid separation.
  • a stirring system and a heating temperature control system are set in the reaction zone of the main reactor.
  • the stirring system is in the form of frame scraping, multiple blades, preferably frame scraping.
  • the heating and temperature control system is arranged on a bed of carbon nanotubes pre-stacked in the reactor, which can be in the form of simple electrodes. Electrodes can be used to directly energize the carbon nanotube bed. Optionally, the carbon nanotube bed can be assisted by resistance wire heating, graphite electrode heating, silicon molybdenum rod heating, and external fuel gas heating.
  • the cathode and anode of the electrode can be arranged in multiple layers and at multiple points to make the temperature zone uniform.
  • the energizing voltage is 12-1000V, preferably 110-380V.
  • the reaction device of the present invention also includes a pressure lock device arranged at the catalyst feed inlet and a pressure lock device arranged at the product outlet to realize high-pressure operation.
  • the feed gas lock valve at the feed point and the discharge gas lock valve at the discharge point ensure that the reactor can continuously react under high pressure, effectively increasing the reaction temperature and increasing the production capacity.
  • the pressure range in the reactor is 0-5Ma, preferably 0-2.0Mpa.
  • the catalyst storage tank is arranged above the main reactor and is connected to the main reactor through a catalyst feed port.
  • the catalyst storage tank is used to place the pretreated catalyst or the catalyst supported on the carbon nanotubes.
  • the catalyst is fed into the main reactor from the catalyst storage tank through the catalyst feed port.
  • a catalyst feed and distributor are provided at the catalyst feed port of the main reactor.
  • the catalyst feed and distributor is a device for secondary dispersion of the catalyst materials fed to the reactor.
  • the device is an annular clock-like disc with a scraper on the upper part and multiple locations on the bottom. Grooved container with ring holes. After the catalyst continues to fall on a certain position of the disc, the scraper rotates quickly to uniformly scrape the catalyst through the circular holes onto the carbon nanotube bed below, so that the catalyst is evenly dispersed into the carbon nanotube bed below without accumulation Together.
  • the discharging device is arranged at the bottom of the main reactor, and the carbon nanotube product is discharged out of the reactor through the reaction material outlet.
  • the discharging device used in the reaction device of the present invention is a tower grate, a flap grate or a star-shaped discharging device.
  • the tower-shaped grate is a multi-layer grate structure with a narrow upper and a wide pagoda shape. There is a certain gap between each upper layer and the lower layer. Each layer has multiple discharge scrapers to remove solid materials from the top. Scrape down, and the gas can be transported from bottom to top through the gaps between the tower grate layers.
  • the multi-layer tower grate has 2-10 layers, preferably 3-5 layers, with multiple discharges on it Scrapers and wear plates.
  • the flap grate is a circular valve grate.
  • the flap with holes is fixed on the reactor along the rotating shaft.
  • the fixed shaft does not move when it is opened, and the rest is turned over to accumulate on the grate.
  • the carbon nanotube product is discharged from the reaction device.
  • the rotating impeller in the star-shaped discharging device plays the role of conveying the material, and the material in the bin is discharged by the gravity of the material and fed into the next device continuously and evenly.
  • the structure of the tower grate, flap grate or star discharger all have voids or holes, so in addition to the discharge function, it can have a gas distribution function. Therefore, in the present invention, the gas inlet of the reactor may be arranged below the discharging device, or may be arranged above the discharging device or integrated on the discharging device, preferably integrated on the discharging device.
  • the gas that enters is discharged from the gap between each layer of the tower grate.
  • a similar gas distribution effect can also be achieved.
  • the discharging method of the present invention is to adopt a flap grate or a multi-layer tower grate followed by a pressure lock.
  • Pressure lock is a kind of equipment that can realize continuous operation under high pressure. It has three parts ABC, where AC is a valve and B is a large material cavity.
  • AC is a valve
  • B is a large material cavity.
  • the device is equipped with a pressure lock, which can realize high-pressure operation of the reaction, is beneficial to reduce the influence of the enlargement of the reactor diameter on heat transfer, and realizes the acceleration of the reaction speed and the increase of the yield of carbon nanotubes per unit volume.
  • the reaction device of the present invention innovatively integrates the mixed gas inlet with the flap valve or the tower grate, which greatly saves the space of the components in the reactor, and is more conducive to the distribution of the reaction gas and the progress of the reaction.
  • Fig. 1 is a schematic diagram of a reaction device using a five-layer tower grate as a discharging device in a preferred embodiment of the present invention.
  • the reaction device shown in Figure 1 includes a main reactor 1.
  • the reaction zone of the main reactor 1 is provided with a stirring system 4 and an electrode heating temperature control system 2, and the bottom of the main reactor 1 is provided with a five-layer tower grate 3, which is located on the five floors.
  • a gas inlet 9 is provided below the tower grate, pressure locks 6 and 6'are provided at the catalyst feed and reaction material outlets at the top of the main reactor 1, and a catalyst cloth is provided at the top of the reactor below the catalyst feed
  • the gas outlet 8 is located on the upper side of the main reactor 1.
  • the catalyst enters the main reactor 1 through the catalyst feed port 5 and the pressure lock 6, passes through the catalyst distributor 7 for secondary dispersion, and then enters the reactor and pre-stacks to the height of the main reactor 3. /4 carbon nanotube stacked bed.
  • the carrier gas and carbon source gas pass through the gas inlet 9 under the five-layer tower grate 3 at the bottom of the main reactor, and enter the main reactor through the tower grate 3
  • the carbon source gas undergoes CVD reaction under the action of a catalyst to generate carbon nanotubes and hydrogen
  • the generated carbon nanotubes gradually increase, which are discharged from the reactor through the scraper discharge of the five-layer tower grate 3, and enter the pressure lock device 6', the pressure lock maintains the high-pressure discharge in the reactor, and discharges the reaction device through the product outlet 10
  • the reaction tail gas and hydrogen are discharged from the outlet 8 at the upper part of the main reactor; keep the reactor at the top of the reactor and continue to discharge at the bottom of the feed, Realize continuous production of carbon nanotubes.
  • Fig. 2 is a schematic diagram of a reaction device using a three-layer tower grate as a discharging device in a preferred embodiment of the present invention.
  • the reaction device shown in Figure 2 includes a main reactor 1, the reaction zone of the main reactor 1 is provided with a stirring system 2, an electrode heating temperature control system 9 and a material height display system 11, and a three-layer tower grate is provided at the bottom of the main reactor 1 3.
  • a gas inlet 13 is provided below the three-layer tower grate, and pressure locks 7 and 7'are provided at the catalyst feed and reaction material outlets at the top of the main reactor 1, and react below the catalyst feed
  • a catalyst distributor 8 is arranged on the top of the reactor, the air outlet 12 is located on the upper side of the main reactor 1, and a filter 6 is arranged before the air outlet.
  • the catalyst enters the main reactor 1 from the catalyst storage tank 5 through the catalyst feed port and the pressure lock 7, passes through the catalyst distributor 8 for secondary dispersion, and then enters the reactor to pre-stack to the main reactor.
  • the reactor height 3/5 carbon nanotube stacked bed, the carrier gas and carbon source gas are preheated in the preheating furnace 4, and then pass through the gas inlet 13 below the three-layer tower grate 3 at the bottom of the main reactor, and then pass through the tower furnace.
  • Grate 3 is fed into the main reactor 1, and the carbon source gas undergoes CVD reaction under the action of the catalyst to generate carbon nanotubes and hydrogen; the material height display system 11 monitors the material height in the reactor in real time, and the carbon nanotubes are generated Gradually increase, the scraper discharge through the three-layer tower grate 3 exits the reactor, enters the pressure lock device 7', the pressure lock maintains the high pressure discharge in the reactor, and exits the reaction device through the product discharge port 10; reaction tail gas and hydrogen It is discharged from the gas outlet 12 at the upper part of the main reactor through the filter 6; the upper part of the reactor is kept continuously feeding and the lower part is continuously discharged to realize continuous production of carbon nanotubes.
  • Fig. 3 is a schematic diagram of a reaction device using a flap grate as a discharging device in a preferred embodiment of the present invention.
  • the reaction device shown in Figure 3 includes a main reactor 1 with an enlarged end.
  • the reaction zone of the main reactor 1 is equipped with a stirring system 2, an electrode heating temperature control system 9 and a material height display system 11, and the bottom of the main reactor 1 is equipped with a mixing system.
  • the gas outlet grate 3 is equipped with pressure locks 7 and 7'at the top of the main reactor 1 at the catalyst feed and at the reaction material outlet, and a catalyst distributor 8 is placed at the top of the reactor below the catalyst feed.
  • the gas outlet 12 is located on the upper side of the main reactor 1, and a filter 6 is provided before the gas outlet.
  • the catalyst enters the main reactor 1 from the catalyst storage tank 5 through the catalyst feed port and the pressure lock 7, and passes through the catalyst distributor 8 for secondary dispersion, and then enters the reactor and pre-stacks to the main reactor.
  • the reactor height is 1/2 of the carbon nanotube stacked bed.
  • the carrier gas and carbon source gas are preheated in the preheating furnace 4 and then enter the main reactor 1 through the mixed gas outlet of the flap grate 3.
  • the carbon source gas is in the catalyst Under the action of CVD, carbon nanotubes and hydrogen are generated by the CVD reaction; the material height in the reactor is monitored in real time through the material height display system 11, and the generated carbon nanotubes gradually increase, open the flap valve, and discharge the carbon nanotubes to the cooling tank , Exit the reactor, enter the pressure lock device 7', the pressure lock maintains the high pressure discharge in the reactor, and exit the reaction device through the product discharge port 10; the reaction tail gas and hydrogen are discharged from the gas outlet 12 on the upper part of the main reactor through the filter 6 ; Maintain continuous feeding at the top of the reactor and continuous discharge at the bottom to achieve continuous production of carbon nanotubes.
  • reaction device is suitable for low-carbon hydrocarbons below 6 carbons, especially methane or propane, and the raw materials are cheap and easy to obtain;
  • the reaction device integrates the flap valve or the tower grate with the reactor, which greatly saves the space of the components in the reactor, and is more conducive to the distribution of reaction gas and the progress of the reaction;
  • the reaction device is equipped with a pressure lock, which can realize high-pressure operation of the reaction, which is beneficial to reduce the influence of the enlargement of the reactor diameter on heat transfer, and can accelerate the reaction speed and increase the yield of carbon nanotubes per unit volume;
  • the present invention adopts a packed bed of carbon nanotube particles with multiple gas pores to mix with a specific proportion of decarbonization gas in the reaction gas, which well solves the problem of carbon-coated deactivation of the catalyst, especially when methane is used as the carbon source. Maintain a high utilization rate of carbon sources to prepare carbon nanotubes and hydrogen;
  • the present invention adopts the method of directly energizing the stacked bed of carbon nanotubes for heating to provide the reaction temperature, which greatly simplifies the supporting facilities of the reaction device, saves space, reduces energy consumption, and controls the temperature more accurately;
  • the method and device of the present invention can prepare high-purity carbon nanotubes at high magnification, with high output, and are suitable for industrialized continuous large-scale production.
  • the methane, propane and ethylene used in the examples were all purchased from Shandong Anze Special Gas Co., Ltd.;
  • Array carbon nanotube powder is GT-210 produced by Shandong Dazhan Nanomaterials Co., Ltd., with a purity of 95.5%;
  • the agglomerated carbon nanotube powder is GT-301 produced by Shandong Dazhan Nanomaterials Co., Ltd., with a purity of 98.8%
  • the ash content of carbon nanotubes is tested.
  • the main ash content is the incombustible magnetic catalyst during the test.
  • Ash determination can determine the carbon phase content in the product and indirectly characterize the purity of carbon nanotubes;
  • the outer diameter and length of carbon nanotubes were determined by scanning electron microscope (SEM) and transmission electron microscope (TEM).
  • the filter cake is granulated, dried at 120°C for 15 hours, and roasted at 400°C for 4 hours;
  • step 2 (3) The particles with a diameter of 10mm obtained in step 2 are blown into a mixture of nitrogen:hydrogen at a ratio of 100L/min:200L/min at 600°C to 630°C, and the reaction is maintained for 10 minutes, and the temperature is lowered for use;
  • the reactor used adopts alumina high-temperature refractory material inside and stainless steel reactor outside. Take 30KG array of carbon nanotubes and put it on top of the five-layer tower grate in advance, and add it to the top of the five-layer tower grate.
  • the tower grate has a gap between layers and a discharge scraper; the main reactor is protected by preheating nitrogen, first turn on the stirring system and then turn on the electrode to heat the carbon nanotube stacked bed and raise it to 820°C-825°C;
  • Step 3 The prepared carbon nanotube catalyst granules are uniformly and continuously fed into the reactor through a pressure lock and a feed distributor;
  • the material is blown into the cooling tank with low-temperature nitrogen for purging and the circulating water coil is cooled to below 50°C, and then transferred to the finished material storage tank.
  • step 2 (2) Pass the precursor obtained in step 1 into an argon:hydrogen mixture with a ratio of 150L/min:200L/min at 580°C-600°C, and keep the reaction for 20min;
  • the reactor used is a quartz reactor, and 20Kg agglomerated carbon nanotubes are added to the quartz reactor beforehand and added to the top of the flap valve.
  • the opening rate of the distributor is 9%, and the hole diameter is 6mm;
  • the main reactor is under the protection of preheating nitrogen, first turn on the stirring system and then turn on the electrode to heat the carbon nanotube composite and raise the temperature to 785°C-800°C;
  • the carbon nanotube catalyst mixture prepared in step 3 is pressure-locked and fed
  • the feed distributor is uniformly and continuously added to the carbon tube bed in the reactor;
  • the material is blown into the cooling tank to purge with low-temperature nitrogen and the circulating water coil is cooled to below 45°C, and then transferred to the finished material storage tank.
  • the weight of the product is weighed to be 72.1Kg. After testing, the purity of the product is ⁇ 99.06%.
  • the SEM photo of the obtained carbon nanotube product is shown in Figure 7, and its morphology is a fiber tubular structure.
  • the reactor used is an all-stainless steel reactor, and the 20Kg array of carbon nanotubes is pre-added to the top of the flap valve in the stainless steel reactor.
  • the opening rate of the distributor is 12%, and the hole diameter is 8mm;
  • the main reactor Under the protection of preheated nitrogen, first turn on the stirring system and then turn on the electrode to heat the carbon nanotubes and raise the temperature to 770°C-780°C; pass the carbon nanotube catalyst granules prepared in step 3 through the pressure lock and feed distributor Evenly and continuously added to the carbon tube bed in the reactor;
  • the material is blown into the cooling tank to purge with low-temperature nitrogen and the circulating water coil is cooled to below 45°C, and then transferred to the finished material storage tank.
  • the weight of the product was weighed to be 54.3Kg, and the product purity was greater than or equal to 99.06% after testing.
  • the SEM photo of the obtained carbon nanotube product is shown in Figure 8, and its morphology is a fiber tubular structure.
  • step 2 The particles obtained in step 2 are blown into a mixture of nitrogen:hydrogen at a ratio of 100L/min:200L/min under the condition of 600°C-630°C, and keep the reaction for 15min, and then wait for use after cooling;
  • the reactor used is a reactor with alumina high-temperature refractory material and stainless steel outside, and 30KG of agglomerated carbon nanotubes is added to the top of the three-layer tower grate in advance.
  • the tower grate has a gas distribution and Discharging scraper: Under the protection of preheated nitrogen, the main reactor first turns on the stirring system and then turns on the electrode to heat the carbon nanotube stacked bed and raise it to 650°C-660°C;
  • the carbon nanotube catalyst granules prepared in step 3 are uniformly and continuously fed into the reactor through the pressure lock and the feed distributor
  • the material is blown into the cooling tank with low-temperature nitrogen purge and the circulating water coil is cooled to below 50°C, and then transferred to the finished material storage tank.
  • the weight of the weighed product is 67.1Kg. After testing, the purity of the product is ⁇ 99.19%.
  • the SEM photo of the obtained carbon nanotube product is shown in Figure 9, and its morphology is a fiber tubular structure.
  • the carbon nanotubes prepared by the method of the present invention have large yield and high purity, and can be widely used in the fields of conductive materials, electromagnetic shielding, solar cells, rubber, and improving the mechanical properties of composite materials. It can be seen from the embodiments of the present invention that the reaction device of the present invention can be used to continuously prepare carbon nanotubes.
  • the method for preparing carbon nanotubes using the reaction device is simple to operate, and has high utilization rates of catalysts and carbon sources, which can meet commercial application requirements , Suitable for industrialized mass production.

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Abstract

一种能连续化生产碳纳米管和氢气的方法，所述方法包括制备催化剂前驱体，对催化剂前驱体进行预还原，在反应器中预先加入一定高度的碳纳米管作为堆积床,在保护性气体的存在下,对碳纳米管进行通电加热至气相沉积炉反应温度，将经过预还原的催化剂或未还原的催化剂前驱体投放至反应器中，在对反应器内固体物料进行搅拌的情况下，向反应器中通入碳源气体,经气相沉积炉反应生成新的碳纳米管和氢气，持续性排出部分碳纳米管和部分氢气，重复上述步骤以实现连续化制备碳纳米管。用于该方法的装置，该装置具有结构简单，成本低，易于操作，原料利用率高的优点，能一次性制得大批量的高纯度碳纳米管，适用于工业化大规模生产。

Description

一种制备碳纳米管和氢气的方法和装置 技术领域
本发明涉及一种制备碳纳米管和氢气的装置及方法,具体涉及一种通过将催化剂堆积在装有出料装置的反应器中经气相沉积反应制备碳纳米管和氢气的工艺方法和装置。
背景技术
碳纳米管具有非常优异的物理机械性能，碳纳米管的微观结构可看作是石墨片卷曲而成的一个无缝中空的管子，它的长径比很大，通常直径在1-100nm之间，长度在几微米到上百微米。碳纳米管具有优异的力学、电学等性能，它的硬度与金刚石相当，杨氏模量约为1.8TPa；拉伸强度约为200GPa，比钢的强度高100倍，重量却只有后者的1/6到1/7。同时，碳纳米管的弹性应变最高可达到12％左右，拥有像弹簧一样良好的柔韧性。碳纳米管的电导率可达到铜的1万倍，导热性也非常好。由于具有优异的性能，碳纳米管在纳米电子器械、催化剂载体、电化学材料、复合材料等诸多领域都有广阔的应用前景。
近年来，随着环保意识的提高和国家政策的引导，氢燃料电池车与锂电池电动车一并成为了未来的发展趋势。随着科技的进步，曾经困扰氢燃料电池发展的诸如安全性、氢燃料的贮存技术等问题已经逐步攻克并不断完善，然而成本问题依然是阻碍氢燃料电池车发展的最大瓶颈。大量高纯度的氢气资源是实现低成本氢燃料电池车的基础资源和保证。
碳纳米管的生产，尤其是批量生产的解决是碳纳米管技术走向应用的前提，同时也是制约该技术产业化的瓶颈。制备碳纳米管的工业化批量制备目前采用电弧法制备单壁碳纳米管以及CVD方式制备多壁碳纳米管，其中CVD法制备多采用流化床、固定床、移动床。碳纳米管所用的碳源主要以低碳的烷烃、烯烃、醇类等为主，也可使用分子量较大的碳源如环己烷、苯、菲等。由于低碳烃类成本低,容易获得,希望采用低碳烃类,例如甲烷、丙烷、乙烯等作为碳源来制备碳纳米管,但由于低碳烃类的特殊性质,在采用甲烷作为碳源进行CVD反应制备碳纳米管的工业化生产时，传统的固定床尽管可以一定程度解决催化剂快速积碳失活问题，但固定床采用的形式通常是将少量的催化剂平铺在瓷舟中，在反应时存在传热传质差的明显短板，产能也较低，使得产 能受到极大限制；而在流化床中因很难解决碳源裂解速度与碳管组装速度不匹配问题而失活。在采用低碳烃类作为碳源制备碳纳米管时,目前传统工艺中存在倍率低、产能小且碳源利用率不高等问题，现有技术很难解决单位体积产能小的技术问题，难以实现大规模工业化生产。
因此，现有技术仍需要开发一种以低碳烃类为碳源通过CVD反应制备碳纳米管和氢气的方法和装置，该装置应具有结构简单，成本低，并能提高催化剂和原料利用率的优点。采用该方法和装置能高倍率地制备得到碳纳米管，产量大，产能高,且碳源利用率高,所得的产品质量稳定，适用于工业化大规模生产。
发明内容
本发明的目的是提供一种能连续化生产碳纳米管和氢气的方法及装置，该装置具有结构简单，成本低，易于操作，原料利用率高的优点，能一次性制得大批量的高纯度碳纳米管，适用于工业化大规模生产。
因此，本发明的一个方面，提供了一种连续化制备碳纳米管和氢气的方法，所述方法包括：
(a)制备催化剂前驱体，或将催化剂前驱体预处理在载体上；
(b)对催化剂前驱体或负载在碳纳米管上的催化剂前驱体进行预还原；
(c)在反应器中预先加入一定高度的碳纳米管作为堆积床,在保护性气体的存在下,对碳纳米管进行通电加热至CVD反应温度；
(d)将步骤(b)得到的催化剂或负载在碳纳米管上的催化剂进料至反应器中；
(e)在对反应器内固体物料进行搅拌的情况下，向反应器中通入碳源气体,经CVD反应生成新的碳纳米管和氢气；
(f)保持碳纳米管床层处于一定料位，持续性排出部分碳纳米管和部分氢气；
(g)重复步骤(d)-(f),以实现连续化制备碳纳米管。
在本发明一个优选的实施方式中，所述载体为碳纳米管或炭黑。
在本发明一个优选的实施方式中，所述将催化剂前驱体预处理在载体上的方法选自沉淀法、浸渍法、溶胶凝胶法、熔融法或热分解法。
在本发明一个优选的实施方式中，所述将催化剂前驱体预处理在碳纳米管载体上的步骤包括采用活性金属盐溶液对碳纳米管载体进行浸渍处理，再进行沉淀、烘干、焙烧。
在本发明一个优选的实施方式中，在步骤(c)中，预先加入的碳纳米管堆积床的高度为反应器高度的1/5-4/5，优选1/2-4/5，从反应器底部起算。
在本发明一个优选的实施方式中，对碳纳米管进行直接通电加热，并任选地采用电阻丝加热、石墨电极加热、硅钼棒加热或其组合形式进行辅助加热。
在本发明一个优选的实施方式中，在步骤(e)中，持续或间歇通入特定比例的消碳气体，所述消碳气体为二氧化碳、氧气、水蒸气或它们的组合，优选二氧化碳。
在本发明一个优选的实施方式中，所述消碳气体与碳源气体的体积比例为0.02-0.3：1，优选0.04-0.15:1。
在本发明一个优选的实施方式中，在步骤(e)中，向反应器中通入碳源气体和载气的混合气体，所述载气选自氮气、氩气和氢气，所述载气与碳源气体的体积比例为0.2-10:1，优选1-5:1。
在本发明一个优选的实施方式中，所述碳源气体为具有等于或小于6个碳原子的烃类，优选甲烷、丙烷、乙烯，更优选甲烷和丙烷。
本发明的另一个方面，提供了一种用于连续化制备碳纳米管和氢气的装置，所述装置包括:
(a)用于进行CVD反应的主反应器，该主反应器具有催化剂进料口、气体进气口、反应物料出口和出气口；在主反应器的反应区域设置搅拌系统、加热控温系统；
(b)催化剂储罐，所述催化剂储罐设置在主反应器上方通过催化剂进料口与主反应器相连；
(c)出料装置，所述出料装置设置在主反应器底部，通过反应物料出口将碳纳米管产品排出反应器；
其中所述气体进气口位于主反应器底部，所述出气口位于主反应器顶部，用于排出反应尾气和氢气。
在本发明一个优选的实施方式中，所述气体进气口位于出料装置下方。
在本发明一个优选的实施方式中，所述气体进气口整合在出料装置上。
在本发明一个优选的实施方式中，所述出料装置为塔型炉箅、翻板炉箅或星型出料器。
在本发明一个优选的实施方式中，所述装置还包括在主反应器的催化剂进料口处设置的催化剂进料和布料器。
在本发明一个优选的实施方式中，所述装置还包括设置在催化剂进料口的压力锁装置，以及设置在产品出口的压力锁装置。
在本发明一个优选的实施方式中，所述装置还包括设置出气口前方的过滤器。
在本发明一个优选的实施方式中，所述装置还包括设置在主反应器反应区域的物料高度显示系统。
在本发明一个优选的实施方式中，反应器内气体的气速为0.02-10m/s，优选0.05-3m/s，更优选0.05-1m/s。
在本发明一个优选的实施方式中，反应温度设置为500℃-1100℃，优选650℃-900℃，更优选700℃-850℃；保护性气体的预热温度为550℃-1100℃，优选650℃-900℃；碳源气体的预热温度为500℃-800℃，优选650℃-800℃。催化剂前驱体的预还原温度为450℃-650℃，所述载气与碳源气体的体积比例为0.2-10:1，优选1-5:1。
附图说明
下面，结合附图对本发明进行说明。
附图中：
图1是本发明的一个实施方式中使用五层塔型炉箅作为出料装置的反应装置示意图；
图2是本发明的另一个实施方式中使用三层塔型炉箅作为出料装置的反应装置示意图；
图3是本发明的另一个实施方式中使用翻板炉箅作为出料装置的反应装置示意图；
图4是本发明的一个优选的实施方式中使用的五层塔型炉箅的示意图；
图5是本发明的一个优选的实施方式中使用的翻板阀的示意图；
图6-9分别是本发明实施例1至实施例4制备的碳纳米管的SEM照片。
具体实施方式
采用本发明的方法和装置可连续化制备碳纳米管和氢气，制备得到的碳纳米管的生长倍率达到120倍以上，纯度≥99％。
以下对所述连续化制备碳纳米管和氢气的方法和使用的反应装置进行描述：
(a) 制备催化剂前驱体，或将催化剂前驱体预处理在载体上
用于制备碳纳米管的催化剂前驱体可采用本领域已知的方法进行，例如，沉淀法、浸渍法、溶胶凝胶法、熔融法、热分解法等，优选采用活性金属盐溶液对载体进行浸渍处理，再进行沉淀、烘干、焙烧。
将催化剂前驱体预处理在载体上可采用浸渍法、凝胶法等。浸渍法可采用活性金属盐溶液对载体进行浸渍处理后用沉淀剂进行沉淀，再经烘干、焙烧等处理制得碳纳米管催化剂混合物前驱体。沉淀剂可采用氨水、氢氧化钠水溶液、碳酸铵溶液等。凝胶法包括将活性金属盐溶液与柠檬酸混合后掺入载体，加热反应后蒸水至特定的溶液密度和粘度后停止反应，然后进行烘干和焙烧。所述载体可以是碳纳米管、炭黑等，优选碳纳米管。
(b) 对催化剂前驱体或负载在碳纳米管上的催化剂前驱体进行预还原
对催化剂前驱体或负载在碳纳米管上的催化剂前驱体进行预还原的步骤可在反应器外预先进行，或者利用反应器内氢气在反应器内部进行。
在本发明中，将碳纳米管催化剂前驱体混合物预先经过还原，有效保持了催化剂活性位点的设计尺寸，最大程度弱化了金属颗粒的聚并和熟化效应，使得生长的碳纳米管具有分布窄的细小管径和更高比表面积。
(c) 在反应器中预先加入一定高度的碳纳米管作为堆积床,在保护性气体 的存在下,对碳纳米管进行通电加热至CVD反应温度
在本发明的方法中，在反应器中预先加入一定高度的纯碳纳米管作为催化剂的支撑体。由于碳纳米管是松散的、内部含有气体通道的特殊材料，可以作为堆积床支撑催化剂。由于催化剂粒径小、密度大，在反应器中加入催化剂或负载在碳纳米管上的催化剂之后，催化剂将在搅拌和重力作用下混入碳纳米管堆积床的孔隙中，实现碳纳米管对催化剂的二次分散。
与采用固定床反应器相比，采用高度合适且疏松多孔的碳纳米管床层进行预填充后，催化剂加入后能够实现更好地传热和接触碳源，提高传热和传质效率；流化床中由于流化气速较大使得催化剂迅速失活，而在堆积床的情况下可以采用较小的气速进行持续生长而不会出现催化失活。针对甲烷、丙烷等低碳烃类碳源，采用堆积床形式进行反应是实现质量稳定且产能最大化的最佳选择方式。
在所述方法的步骤(c)中，预先加入的碳纳米管堆积床的高度为反应器高度的1/5-4/5，优选1/2-4/5，从反应器底部起算。床层过低时，少量的碳管不足以充分地对催化剂进行支撑和分散；床层过高时，催化剂的生长空间受到限制，不能及时与碳源进行有效接触。此外，碳纳米管床层是通电加热的导电介质，若用量太少不足以提供足够的热量。
优选地，在反应器内配置物料高度监测装置，可实时监测物料位置，可以实时了解反应器内物料高度情况，便于精细的自动化操作。通过监控物料的高度可以反馈反应的稳定情况，同时可以及时进行参数调整，调节催化剂的加入和物料的卸出。
在本发明中，术语“保护性气体”是指不会干扰碳源和催化剂反应的气体，其非限定性例子有，例如氮气、氦气、氩气等或它们的混合气。
在保护性气体的存在下，由于碳纳米管是良导体，可以对碳纳米管直接进行通电加热，以使反应器达到CVD反应温度。升温过程也可以利用外部加热 进行或者同时对碳纳米管进行通电发热和外部加热。
所述反应加热形式可以为直接对碳管进行加热，优选使用电极对碳管进行直接通电的加热形式。任选地，还可以采用电阻丝加热、石墨电极加热、硅钼棒加热、外部燃气火力加热等形式进行辅助加热。采用对碳纳米管堆积床直接通电进行加热以提供反应温度的方式，极大简化了反应装置的配套设施，节省空间，减少能耗，控温更加精准。
(d) 将步骤(b)得到的催化剂或负载在碳纳米管上的催化剂进料至反应 器中
经过预还原的催化剂或碳纳米管载体催化剂储存在催化剂储罐中，催化剂储罐设置在主反应器上方通过催化剂进料口与主反应器相连，储罐中的催化剂经过催化剂进料口进入主反应器。
优选地，经过预还原的催化剂或碳纳米管载体催化剂通过催化剂进料及布料分布器加入到反应器中。所述催化剂进料及布料器是一种对进料至反应器的催化剂物料进行二次分散的装置，该装置是一种环形的类似钟表式的圆盘，上部具有刮刀，底部是具有多处环孔的槽型容器。催化剂持续落在圆盘的某个位置后，刮刀快速地旋转将催化剂通过圆孔均匀地刮到下方的碳纳米管床层上，使得催化剂均匀分散到下方碳纳米管床层中，而不堆积在一起。
(e) 在对反应器内固体物料进行搅拌的情况下，向反应器中通入碳源气体, 经CVD反应生成新的碳纳米管和氢气
在本发明的主反应器中的反应区域设置有搅拌系统，搅拌系可以为从反应器顶部至底部上下一体的搅拌系统，也可以在反应器顶部和底部分别设置两套独立的搅拌系统。可以将两套搅拌系统设置为间断开启模式或者连续开启模式，更加机动灵活。搅拌装置可以使物料混匀并消除可能产生的气体沟流和反应物料结块。
所述搅拌系统为框式刮壁形式、多片桨叶形式，优选框式刮壁形式。对于适用于本发明的搅拌系统没有特别限制，只要能对物料进行物理搅拌，实现物料的均匀混合即可。
碳源气体通过位于主反应器底部的气体进气口进入主反应器。本发明方法中使用的碳源气体为具有等于或小于6个碳原子的烃类，优选甲烷、丙烷、乙烯，更优选甲烷和丙烷。在此步骤中，可以通入碳源气体和载气的混合气体。 载气包括但不限于氮气、氩气和氢气，所述载气与碳源气体的体积比例为0.2-10:1，优选1-5:1。当载气为氮气或氩气时，起到惰性保护和稀释碳源气体浓度的作用,当载气为氢气时，氢气可以调控碳源气体的浓度以及刻蚀反应中产生的无定形碳，起到稀释作用。
对于通入气体的形式没有特别限制，碳源气体和载气可以混合气形式通入，也可以先后通入一定体积的碳源气体和载气。在步骤(e)中，载气与碳源气体的体积比例为0.2-10:1，优选1-5:1。
在本发明中，优选地，在步骤(e)中，持续或间歇通入特定比例的消碳气体，所述消碳气体为二氧化碳、氧气、水蒸气或它们的组合，优选二氧化碳。消碳气体与碳源气体的体积比例为0.02-0.3：1，优选0.04-0.15:1。以甲烷等低碳烃类为碳源生产碳纳米管时，在工业应用上极易导致催化剂包碳失活的问题，无法在催化剂上长出高倍率碳纳米管，本发明采用具有多气体孔道的碳纳米管颗粒堆积床配合在反应气体中混入特定比例消碳气体，很好地解决了以甲烷为碳源时催化剂的包碳失活问题，能实现以高碳源利用率制备碳纳米管和氢气。
(f)保持碳纳米管床层处于一定料位，持续性排出部分碳纳米管和部分氢气；
出料装置设置在主反应器底部，保持碳纳米管床层处于一定料位，例如，保持料位为反应器高度的1/5-4/5，优选1/2-4/5，从反应器底部起算，将部分碳纳米管产品通过出料装置排出反应器。反应尾气和氢气通过位于主反应器顶部的出气口排出反应器。
(g)重复步骤(d)-(f),以实现连续化制备碳纳米管。
重复步骤(d)-(f)，保持反应器上方催化剂持续进料下方持续出料，以实现连续化制备碳纳米管。
在本发明一个较好的实施例中，采用本发明所述反应装置连续化制备碳纳米管的方法包括如下具体步骤：
(1)制备催化剂前驱体，或将催化剂前驱体预处理在碳纳米管；
(2)将催化剂前驱体经过预还原或者利用反应炉内氢气进行还原；
(3)在反应器中加入特定高度的碳纳米管，通入一定流量预热后的保护气 体，对碳纳米管开启通电升温到工艺温度，升温过程可以利用外部加热或者对碳纳米管进行通电发热或者二者同时进行加热；
(4)将催化剂或者碳纳米管载体催化剂通过催化剂定量进料压力锁及布料分布器加入反应器中；
(5)在反应过程中保持搅拌或者进行间歇性搅拌，经过气体分布器通入一定比例经过预热的碳源与保护气体的混合气，并持续或间歇通入特定比例的消碳气体；
(6)混合物料经CVD反应而进行碳纳米管的生长；反应器顶部尾气经分离器排出反应器；
(7)开启出料装置，其中翻板炉箅为间歇开启，塔型炉箅为连续刮刀排料，并在惰性气氛下通过出料口排出进入降温罐完成卸料和降温；物料降温后转移至成品储罐；
(8)如此重复(4)-(7)而保持上方催化剂持续进料下方持续出料实现连续生产制备。
在本发明一个较好的实施例中，反应器内气体的气速为0.05-1m/s。
在本发明一个较好的实施例中，反应温度设置为700℃-850℃；保护性气体的预热温度为650℃-900℃；碳源气体的预热温度为650℃-800℃。催化剂前驱体的预还原温度为450℃-650℃，载气与碳源气体的比例为0.2-10:1，优选1-5:1。
以下对连续化制备碳纳米管和氢气的装置的具体部件进行描述：
(1)主反应器
在本发明中，主反应器是指适于采用催化剂催化裂解碳源进行CVD反应制备碳纳米管的反应器，在该反应器中，在合适的温度下，例如500-1100℃，优选650-900℃，更优选700-800℃的条件下，碳源在催化剂的作用下，在催化剂载体上生长出碳纳米管。
在本发明中，反应器可采用堆积床反应器，其顶部或者底部带有搅拌系统且进料和出料处带有压力锁以实现高压操作。所述反应器的高度与直径的长径比为2-25：1，优选3-10：1，更优选3-6:1。
所述“堆积床”反应器是指反应器内部具有预先堆积至一定高度的碳纳 米管床反应区域，催化剂均匀分散在碳纳米管堆积床的孔隙中，碳源气体在催化剂的作用下进行CVD反应生成新的碳纳米管。对于适用于本发明的反应器没有特别限制，只要能提供进行CVD反应的碳纳米管堆积床的反应区域即可。
在本发明中，所述反应器为内胆衬耐高温绝缘层的不锈钢反应器、金属反应器、石英管反应器、耐高温材料围成的桶状和窑状反应器或者他们的组合，优选内胆衬耐高温绝缘层的不锈钢反应器。
本发明的主反应器具有催化剂进料口、气体进气口、反应物料出口和出气口。
碳源气体、保护气体和载体通过位于主反应器底部的气体进气口进入主反应器。所述气体进气口可以设置在出料装置的下方，也可以设置在出料装置的上方，或者整合在出料装置上，与出料装置一体化设置，优选所述气体进气口整合在出料装置上。
在本发明中，所述出气口设置在主反应器的上部，所述主反应器还包括设置在出气口前方的过滤器。过滤器为高目数高温不锈钢粉末压制而成的具有微米级孔隙的过滤器，以实现气固分离。反应尾气和部分氢气经出气口排出反应器后，进入PSA系统进行氢气提纯，纯度可达99.99％。
在主反应器的反应区域设置搅拌系统、加热控温系统。所述搅拌系统为框式刮壁形式、多片桨叶形式，优选框式刮壁形式。对于适用于本发明的搅拌系统没有特别限制，只要能对物料进行物理搅拌，实现物料的均匀混合即可。
加热控温系统设置在预先堆积在反应器中的碳纳米管床上，其可以是简单的电极形式。可采用电极对碳纳米管床直接进行通电加热，任选地，采用电阻丝加热、石墨电极加热、硅钼棒加热、外部燃气火力加热等形式对碳纳米管床进行辅助加热。电极阴阳两极可以多层、多点布设以使温区均匀。通电电压为12-1000V,优选110-380V。
本发明的反应装置还包括设置在催化剂进料口的压力锁装置，以及设置在产品出口的压力锁装置，以实现高压操作。进料处的进料锁气阀和放料处的排料锁气阀，保证了反应器能够在高压下连续进行反应，有效提高反应温度，提高产能。反应器内压力范围为0-5Ma，优选0-2.0Mpa。
(2)催化剂储罐
催化剂储罐设置在主反应器上方通过催化剂进料口与主反应器相连，所 述催化剂储罐用于放置经过预处理的催化剂或负载在碳纳米管上的催化剂。催化剂从催化剂储罐中经过催化剂进料口加入主反应器中。
优选地，在主反应器的催化剂进料口处设置催化剂进料和布料器。所述催化剂进料及布料器是一种对进料至反应器的催化剂物料进行二次分散的装置，该装置是一种环形的类似钟表式的圆盘，上部具有刮刀，底部是具有多处环孔的槽型容器。催化剂持续落在圆盘的某个位置后，刮刀快速地旋转将催化剂通过圆孔均匀地刮到下方的碳纳米管床层上，使得催化剂均匀分散到下方碳纳米管床层中，而不堆积在一起。
(3)出料装置
出料装置设置在主反应器底部，通过反应物料出口将碳纳米管产品排出反应器。
在本发明的反应装置中使用的出料装置为塔型炉箅、翻板炉箅或星型出料器。如图4所示，塔形炉箅为多层炉箅结构，呈现上窄下宽的宝塔形状，每个上层和下层之间有一定空隙，每层有多把排料刮刀将固体物料从上往下刮料，而气体可通过塔形炉箅层间的空隙从下往上输送，所述多层塔式炉箅为2-10层，优选3-5层，其上具有多把排料刮刀和耐磨片。
如图5所示，翻板炉箅为圆形的阀门炉箅，带孔的翻板沿转轴固定在反应器上，在开启时固定轴不动，其余部分进行翻转，将积聚在炉箅上的碳纳米管产品排出反应装置。
星型出料器中旋转的叶轮起着输送物料的作用，依靠物料的重力作用将仓内的物料卸出并连续均匀地喂入下一装置中。
塔型炉箅、翻板炉箅或星型出料器的结构中均具有空隙或孔，因此，除排料功能外可带有布气功能。因此，在本发明中，反应器的气体进气口可以设置在出料装置下方，也可以设置在出料装置上方或整合在出料装置上，优选一体化整合在出料装置上。混合气体由气体进气口从下往上经过塔形炉箅进入反应区域时，进入的气体从塔型炉箅每层的间隙处排出，以俯瞰的视角来看，即一个圆面内呈现从圆心辐射到四周多处的布气效果，以这种形式进行气体分布均匀性好，出气气速一致，有助于反应进行。混合气体经由翻板炉箅翻板上的孔或星型出料器的旋转叶轮进入反应区域时，也能实现类似的布气效果。
优选地，本发明的出料方式为采用翻板炉箅或者多层塔式炉箅后接压力 锁。压力锁是在高压条件下能够实现连续化操作的一种设备，具有ABC三个部件，其中AC为阀门，B为一个大的物料空腔，反应器在保持高压的情况下，先打开A阀门，反应器内物料进入B腔内，待压力一致后，关闭A阀门，开启C阀门将物料排出，如此完成一次排料；可调节其AC的气动开启频率实现连续出料。本装置装配有压力锁，可以实现反应的高压操作，有利减少反应器直径的放大对传热的影响，并实现加快反应速度、提高单位体积的碳纳米管产量。
本发明的反应装置创新性地将混合气进气与翻板阀或者塔型炉箅整合在一起，大大节省了反应器内的构件空间，更利于反应气体的分布和反应的进行。
以下结合附图对本发明的具体实施方式进行详细描述：
图1是本发明一个较好的实施方式中使用五层塔型炉箅作为出料装置的反应装置示意图。
图1中所示反应装置包括主反应器1，主反应器1反应区域设置有搅拌系统4和电极加热控温系统2，主反应器1底部设置有五层塔型炉箅3，在五层塔型炉箅下方设置有气体进气口9，在主反应器1顶部的催化剂进料处和反应物料出口处设置有压力锁6和6’，在催化剂进料处下方反应器顶部设置催化剂布料器7，出气口8位于主反应器1上部一侧。
使用图1所示的反应装置时，催化剂经过催化剂进料口5和压力锁6进入主反应器1，经过催化剂布料器7进行二次分散，然后进入反应器中预先堆积至主反应器高度3/4的碳纳米管堆积床，载气和碳源气体在预热后经过主反应器底部五层塔型炉箅3下方的进气口9，经过塔型炉箅3进气布气进入主反应器1，碳源气体在催化剂的作用下进行CVD反应生成碳纳米管和氢气；生成的碳纳米管逐渐增多，经过五层塔型炉箅3的刮刀排料排出反应器，进入压力锁装置6’，压力锁保持反应器内高压排料，经产品出料口10排出反应装置；反应尾气和氢气从主反应器上部的出气口8排出；保持反应器上方持续进料下方持续排料，实现连续化生产碳纳米管。
图2是本发明一个较好的实施方式中使用三层塔型炉箅作为出料装置的反应装置示意图。
图2中所示反应装置包括主反应器1，主反应器1反应区域设置有搅拌系统2，电极加热控温系统9和物料高度显示系统11，主反应器1底部设置有三层塔 型炉箅3，在三层塔型炉箅下方设置有气体进气口13，在主反应器1顶部的催化剂进料处和反应物料出口处设置有压力锁7和7’，在催化剂进料处下方反应器顶部设置催化剂布料器8，出气口12位于主反应器1上部一侧，在出气口之前设置过滤器6。
使用图2所示的反应装置时，催化剂从催化剂储罐5经过催化剂进料口和压力锁7进入主反应器1，经过催化剂布料器8进行二次分散，然后进入反应器中预先堆积至主反应器高度3/5的碳纳米管堆积床，载气和碳源气体经过预热炉4预热后通过主反应器底部三层塔型炉箅3下方的进气口13，经过塔型炉箅3进气布气进入主反应器1，碳源气体在催化剂的作用下进行CVD反应生成碳纳米管和氢气；通过物料高度显示系统11实时监测反应器中的物料高度，生成的碳纳米管逐渐增多，经过三层塔型炉箅3的刮刀排料排出反应器，进入压力锁装置7’，压力锁保持反应器内高压排料，经产品出料口10排出反应装置；反应尾气和氢气经过过滤器6从主反应器上部的出气口12排出；保持反应器上方持续进料下方持续排料，实现连续化生产碳纳米管。
图3是本发明一个较好的实施方式中使用翻板炉箅作为出料装置的反应装置示意图。
图3中所示反应装置包括带扩大端的主反应器1，主反应器1反应区域设置有搅拌系统2，电极加热控温系统9和物料高度显示系统11，主反应器1底部设置有带混合气出气口的翻板炉箅3，在主反应器1顶部的催化剂进料处和反应物料出口处设置有压力锁7和7’，在催化剂进料处下方反应器顶部设置催化剂布料器8，出气口12位于主反应器1上部一侧，在出气口之前设置过滤器6。
使用图3所示的反应装置时，催化剂从催化剂储罐5经过催化剂进料口和压力锁7进入主反应器1，经过催化剂布料器8进行二次分散，然后进入反应器中预先堆积至主反应器高度1/2的碳纳米管堆积床，载气气体和碳源气体经过预热炉4预热后通过翻板炉箅3的混合气出气口进入主反应器1，碳源气体在催化剂的作用下进行CVD反应生成碳纳米管和氢气；通过物料高度显示系统11实时监测反应器中的物料高度，生成的碳纳米管逐渐增多，开启翻板阀，将碳纳米管卸料至冷却罐，排出反应器，进入压力锁装置7’，压力锁保持反应器内高压排料，经产品出料口10排出反应装置；反应尾气和氢气经过过滤器6从主反应器上部的出气口12排出；保持反应器上方持续进料下方持续排料，实现连续化生产碳纳米管。
本发明的有益效果在于：
(1)反应装置适合6碳以下的低碳烃类，尤其是甲烷或丙烷，原料便宜易得；
(2)反应装置将翻板阀或者塔型炉箅与反应器整合在一起，大大节省了反应器内的构件空间，更利于反应气体的分布和反应的进行；
(3)反应装置装配有压力锁，可以实现反应的高压操作，有利减少反应器直径的放大对传热的影响，能加快反应速度、提高单位体积的碳纳米管产量；
(4)本发明采用了具有多气体孔道的碳纳米管颗粒堆积床配合在反应气体中混入特定比例消碳气体，很好地解决了催化剂的包碳失活问题，尤其以甲烷为碳源时保持高碳源利用率制备碳纳米管和氢气；
(5)本发明采用对碳纳米管堆积床直接通电进行加热的方式以提供反应温度，极大简化了反应装置的配套设施，节省空间，减少能耗，控温更加精准；
(6)本发明的方法和装置能以高倍率制备得到高纯度的碳纳米管，产量高，适用于工业化连续化大规模生产。
下面结合具体实施例对本发明做进一步说明。应理解，这些实施例仅用于说明本发明而不用于限制本发明的范围。对于下列实施例中未注明具体条件的实验方法，通常按照常规条件，或按照制造厂商所建议的条件。比例和百分比基于摩尔量，除非特别说明。
原料来源及制备：
(1)碳源：
实施例中所用的甲烷、丙烷和乙烯均采购自山东安泽特种气体有限公司；
(2)碳纳米管：
阵列碳纳米管粉体为山东大展纳米材料有限公司生产的GT-210，纯度为95.5％；
聚团状碳纳米管粉体为山东大展纳米材料有限公司生产的GT-301，纯度为98.8％
(3)固体化学试剂：
九水硝酸铝、九水硝酸铁、六水硝酸镍、六水硝酸钴、六水硝酸锰和六 水硝酸镁，购自淄博爱肯经贸有限公司；
产品性能测试：
(1)灰分测试：
根据国标GB/T 24490-2009测试碳纳米管的灰分，灰分主要成分即为测试过程中无法燃烧的磁性催化剂，灰分测定可以确定产品中的碳相含量，间接表征碳纳米管的纯度；
(2)比表面积测试：
根据国标GB/T 10722-2014使用氮气物理吸附仪测试产品比表面积；
(3)微观形貌测试：
通过扫描电子显微镜(SEM)、透射电子显微镜(TEM)确定碳纳米管的外径、长度。
实施例1：
基于图1所述的反应装置，采用如下步骤制备碳纳米管：
(1)取20Kg纯化后阵列碳纳米管粉体，对阵列碳纳米管粉体进行预氧化，并用九水硝酸铁和九水硝酸铝的金属盐溶液浸渍12h；
(2)将得到的物料过滤后滤饼造粒，120℃烘干15h，400℃焙烧4h；
(3)将步骤2所得直径10mm的颗粒在600℃-630℃条件下通入氮气：氢气比例为100L/min:200L/min的混合气，并保持反应10min，降温后待用；
(4)所用反应器采用内部为氧化铝高温耐火材料外部为不锈钢反应器，取30KG的阵列碳纳米管预先加入到五层塔型炉箅的上方，加入到五层塔型炉箅的上方，塔型炉箅具有层间间隙和排料刮刀；主反应器在预热氮气保护下，先开启搅拌系统再开启电极对碳纳米管堆积床进行加热并升温至820℃-825℃；将步骤3制备好的碳纳米管催化剂造粒物通过压力锁、进料布料器均匀连续地加入反应器中；
(5)通入氮气：甲烷：二氧化碳比例为1000L/min:520L/min:50L/min的反应气体，保持反应器内压力在0.7±0.1MPa，在820℃±3℃条件下进行反应；
(6)反应生成的物料经塔型炉箅排料刮刀连续进入压力锁后从出料口排出反应器进入冷却罐；持续进行上述步骤(4)-(6)，即可连续化生产多壁碳纳米管；
(7)物料在冷却罐中通入低温氮气吹扫以及循环水盘管降温至50℃以下， 再将其转移至成品物料储罐。
持续反应时间达到60min后，称量产物重量为62.9Kg，经测试，产物纯度≥99.23％，得到的碳纳米管产品的SEM照片如图6所示，其形貌为纤维的管状结构。
实施例2：
基于图3所述的反应装置，采用如下步骤制备碳纳米管：
(1)制备820g凝胶法制备的钴镍系催化剂前驱体，按照配方，称取定量的六水硝酸镍、六水硝酸钴以及柠檬酸溶解到纯化水中，加热反应4-8h，80℃蒸水至密度和粘度合格后，120℃烘干后600℃焙烧4h，过80目筛待用；
(2)将步骤1得到的前驱体在580℃-600℃条件下通入氩气：氢气比例为150L/min:200L/min的混合气，并保持反应20min；
(3)将步骤2得到的催化剂与40Kg聚团状碳纳米管粉体混合均匀；
(4)所用反应器采用石英反应器，取20Kg聚团状碳纳米管预先加入到石英反应器中的加入到翻板阀的上方，分布器的开孔率为9％,孔直径为6mm；主反应器在预热氮气保护下，先开启搅拌系统再开启电极对碳纳米管复合物进行加热并升温至785℃-800℃；将步骤3制备好的碳纳米管催化剂混合物通过压力锁、进料布料器均匀连续地加入到反应器内的碳管床层中；
(5)通入氩气：甲烷：二氧化碳比例为1200L/min:400L/min:60L/min的反应气体，保持反应器内压力在1.2±0.1MPa，在790℃±4℃条件下进行反应；
(6)反应生成的物料经翻板炉箅间歇进入压力锁后从出料口排出反应器进入冷却罐；持续进行上述步骤(4)-(6)，即可连续化生产多壁碳纳米管；
(7)物料在冷却罐中通入低温氮气吹扫以及循环水盘管降温至45℃以下，再将其转移至成品物料储罐。
连续反应时间达到75min后，称量产物重量为72.1Kg，经测试，产物纯度≥99.06％，得到的碳纳米管产品的SEM照片如图7所示，其形貌为纤维的管状结构。
实施例3：
基于图3所述的反应装置，采用如下步骤制备碳纳米管：
(1)制备10Kg的100-120目的活性片层催化剂前驱体，采用天然片层原料-蛭石，将100-120目的蛭石片浸泡于六水硝酸钴和九水硝酸铁的活性金属溶液 中，静置4-7天后，过滤；
(2)将上述前驱体过滤后130℃烘干20h，450℃焙烧3h，研磨后过100目筛网，然后与50Kg阵列碳纳米管粉体进行混合干法造粒，造粒后球状颗粒直径为11mm；
(3)将步骤2所得产物中的21Kg直径11mm的颗粒在580℃-600℃条件下通入氩气：氢气比例为100L/min:160L/min的混合气，并保持反应15min；
(4)所用反应器采用全不锈钢反应器，取20Kg阵列碳纳米管预先加入到不锈钢反应器中的翻板阀的上方，分布器的开孔率为12％,孔直径为8mm；主反应器在预热氮气保护下，先开启搅拌系统再开启电极对碳纳米管进行加热并升温至770℃-780℃；将步骤3制备好的碳纳米管催化剂造粒物通过压力锁、进料布料器均匀连续地加入到反应器内的碳管床层中；
(5)通入氩气：丙烷：二氧化碳比例为300L/min:100L/min:6L/min的反应气体，保持770℃±5℃反应90min；
(6)反应时间达到90min后，停止通入反应气体，保持通入550L/min氮气,开启翻板阀，将碳纳米管卸料至冷却罐；持续进行上述步骤(4)-(6)，即可连续化生产多壁碳纳米管；
(7)物料在冷却罐中通入低温氮气吹扫以及循环水盘管降温至45℃以下，再将其转移至成品物料储罐。称量产物重量为54.3Kg，经测试，产物纯度≥99.06％，得到的碳纳米管产品的SEM照片如图8所示，其形貌为纤维的管状结构。
实施例4：
基于图2所述的反应装置，采用如下步骤制备碳纳米管：
(1)采用共沉淀法制备300g钴锰催化剂前驱体：按照配方将六水硝酸钴加入到硝酸锰溶液中，并用纯化水稀释至合适浓度，再加入九水硝酸铝和六水硝酸镁配成金属溶液；采用氢氧化钠稀溶液作为沉淀剂，采用共沉淀方法将两种溶液滴加混合，实现不同金属盐的共沉淀，反应完成后过滤，滤饼水洗至中性；
(2)将得到的滤饼，120℃烘干12h，600℃焙烧4h；
(3)将步骤2所得的颗粒在600℃-630℃条件下通入氮气：氢气比例为100L/min:200L/min的混合气，并保持反应15min，降温后待用；
(4)所用反应器采用内部为氧化铝高温耐火材料外部为不锈钢的反应器，取30KG的聚团碳纳米管预先加入到三层塔型炉箅的上方，塔型炉箅带有气体分 布和排料刮刀；主反应器在预热氮气保护下，先开启搅拌系统再开启电极对碳纳米管堆积床进行加热并升温至650℃-660℃；
将步骤3制备好的碳纳米管催化剂造粒物通过压力锁、进料布料器均匀连续地加入到反应器内
(5)通入氮气：乙烯：二氧化碳比例为800L/min:650L/min:30L/min的反应气体，保持反应器内压力在0.3±0.1MPa，在660℃±3℃条件下进行反应；
(6)反应生成的物料经塔型炉箅排料刮刀连续进入压力锁后从出料口排出反应器进入冷却罐；持续进行上述步骤(4)-(6)，即可连续化生产多壁碳纳米管；
(7)物料在冷却罐中通入低温氮气吹扫以及循环水盘管降温至50℃以下，再将其转移至成品物料储罐。
持续反应时间达到60min后，称量产物重量为67.1Kg，经测试，产物纯度≥99.19％，得到的碳纳米管产品的SEM照片如图9所示，其形貌为纤维的管状结构。
经本发明所述方法制得的碳纳米管产量大、纯度高，可广泛用于导电材料、电磁屏蔽、太阳能电池、橡胶领域、提高复合材料力学性能等等。从本发明实施例可以看出，采用本发明所述反应装置可以连续制备碳纳米管，利用该反应装置制备碳纳米管的方法操作简单，催化剂和碳源的利用率高，可满足商业应用需求，适合工业化大规模生产。
本发明连续化制备碳纳米管和氢气的工艺方法，其原料配比用量及工艺参数不局限于上述列举的实施例。在阅读了本发明的上述讲授内容之后，本领域技术人员可以对本发明作各种改动或修改，这些等价形式同样落于本申请所附权利要求书所限定的范围。

Claims (10)

  1. 一种连续化制备碳纳米管和氢气的方法，所述方法包括：
    (a)制备催化剂前驱体，或将催化剂前驱体预处理在载体上；
    (b)对催化剂前驱体或负载在碳纳米管上的催化剂前驱体进行预还原；
    (c)在反应器中预先加入一定高度的碳纳米管作为堆积床,在保护性气体的存在下,对碳纳米管进行通电加热至CVD反应温度；
    (d)将步骤(b)得到的催化剂或负载在碳纳米管上的催化剂投放至反应器中；
    (e)在对反应器内固体物料进行搅拌的情况下，向反应器中通入碳源气体,经CVD反应生成新的碳纳米管和氢气；
    (f)保持碳纳米管床层处于一定料位，持续性排出部分碳纳米管和部分氢气；
    (g)重复步骤(d)-(f),以实现连续化制备碳纳米管。
  2. 如权利要求1所述的方法，其特征在于，所述将催化剂前驱体预处理在载体上的方法选自沉淀法、浸渍法、溶胶凝胶法、熔融法或热分解法。
  3. 如权利要求1所述的方法，其特征在于，在步骤(c)中，预先加入的碳纳米管堆积床的高度为反应器高度的1/5-4/5，优选1/2-4/5，从反应器底部起算。
  4. 如权利要求1所述的方法，其特征在于，对碳纳米管进行直接通电加热，并任选地采用电阻丝加热、石墨电极加热、硅钼棒加热或其组合形式进行辅助加热。
  5. 如权利要求1所述的方法，其特征在于，在步骤(e)中，持续或间歇通入特定比例的消碳气体，所述消碳气体为二氧化碳、氧气、水蒸气或它们的组合，优选二氧化碳。
  6. 如权利要求1所述的方法，其特征在于，所述碳源气体为具有等于或小于6个碳原子的烃类，优选甲烷、丙烷、乙烯，更优选甲烷和丙烷。
  7. 一种用于连续化制备碳纳米管和氢气的装置，其特征在于，所述装置包括:
    (a)用于进行CVD反应的主反应器，该主反应器具有催化剂进料口、气体进气口、反应物料出口和出气口；在主反应器的反应区域设置搅拌系统、加热控温系统；
    (b)催化剂储罐，所述催化剂储罐设置在主反应器上方通过催化剂进料口与主反应器相连；
    (c)出料装置，所述出料装置设置在主反应器底部，通过反应物料出口将碳纳米管产品排出反应器；
    其中所述气体进气口位于主反应器底部，所述出气口位于主反应器顶部，用于排出反应尾气和氢气。
  8. 如权利要求7所述的装置，其特征在于，所述出料装置为塔型炉箅、翻板炉箅或星型出料器。
  9. 如权利要求7所述的装置，其特征在于，所述装置还包括在主反应器的催化剂进料口处设置的催化剂进料和布料器。
  10. 如权利要求8所述的装置，其特征在于，所述装置还包括设置在催化剂进料口的压力锁装置，以及设置在产品出口的压力锁装置。
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114558521A (zh) * 2022-03-10 2022-05-31 无锡碳谷科技有限公司 一种分层布料移动床反应装置及使用方法

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11685651B2 (en) * 2019-10-25 2023-06-27 Mark Kevin Robertson Catalytic decomposition of hydrocarbons for the production of hydrogen and carbon
CN113667961B (zh) * 2021-07-31 2023-07-07 山西国脉金晶碳基半导体材料产业研究院有限公司 化学气相沉积高品质金刚石的制备装置及制备方法
CN115043376B (zh) * 2022-06-01 2024-05-07 苏州道顺电子有限公司 一种甲烷催化裂解制氢副产碳材料的方法
CN115626635A (zh) * 2022-11-01 2023-01-20 山东大展纳米材料有限公司 一种轻质高强碳纳米管气凝胶的制备装置及方法

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007112677A (ja) * 2005-10-21 2007-05-10 Takao Kamiyama ナノカーボンの連続製造装置及びその連続製造方法
CN102482098A (zh) * 2009-09-10 2012-05-30 国立大学法人东京大学 碳纳米管和氢的同时制造方法以及碳纳米管和氢的同时制造装置
CN107311150A (zh) * 2017-08-25 2017-11-03 安徽智博新材料科技有限公司 一种高效连续化流化床制备碳纳米管的方法
CN108946704A (zh) * 2018-08-20 2018-12-07 山东晶石大展纳米科技有限公司 一种连续化制备高纯碳纳米管的方法及装置
CN109698033A (zh) * 2018-11-07 2019-04-30 张育曼 用碳材增强热激发的低能核反应器及其产能方法和能源装置
CN110203905A (zh) * 2019-05-22 2019-09-06 山东晶石大展纳米科技有限公司 一种高补强多壁阵列碳纳米管的制备装置及工艺
CN110282614A (zh) * 2019-06-26 2019-09-27 山东晶石大展纳米科技有限公司 一种可连续进行碳纳米管纯化的系统及方法

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1141250C (zh) * 2001-05-25 2004-03-10 清华大学 一种流化床连续化制备碳纳米管的方法及其反应装置
WO2009110885A1 (en) * 2008-03-03 2009-09-11 Performance Polymer Solutions, Inc. Continuous process for the production of carbon nanotube reinforced continuous fiber preforms and composites made therefrom
RU2497752C2 (ru) * 2011-11-29 2013-11-10 Инфра Текнолоджис Лтд. Способ получения длинных углеродных нанотрубок и устройство для осуществления этого способа
KR101746260B1 (ko) * 2014-06-12 2017-06-12 주식회사 엘지화학 담지 촉매, 이로부터 얻어진 탄소나노튜브 응집체 및 이들의 제조방법
CN108311064A (zh) * 2017-01-16 2018-07-24 赵社涛 一种用于碳纳米管生产的卧式搅拌反应器
CN108726507B (zh) * 2017-04-21 2020-11-13 山东大展纳米材料有限公司 一种单级连续化制备碳纳米管的装置及方法
CN109928361B (zh) * 2019-03-19 2020-10-09 中国矿业大学 一种具有自催化功能的碳纳米管兼氢气生产系统及方法
CN110330008A (zh) * 2019-06-20 2019-10-15 徐成德 一种碳纳米管的连续生产方法

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007112677A (ja) * 2005-10-21 2007-05-10 Takao Kamiyama ナノカーボンの連続製造装置及びその連続製造方法
CN102482098A (zh) * 2009-09-10 2012-05-30 国立大学法人东京大学 碳纳米管和氢的同时制造方法以及碳纳米管和氢的同时制造装置
CN107311150A (zh) * 2017-08-25 2017-11-03 安徽智博新材料科技有限公司 一种高效连续化流化床制备碳纳米管的方法
CN108946704A (zh) * 2018-08-20 2018-12-07 山东晶石大展纳米科技有限公司 一种连续化制备高纯碳纳米管的方法及装置
CN109698033A (zh) * 2018-11-07 2019-04-30 张育曼 用碳材增强热激发的低能核反应器及其产能方法和能源装置
CN110203905A (zh) * 2019-05-22 2019-09-06 山东晶石大展纳米科技有限公司 一种高补强多壁阵列碳纳米管的制备装置及工艺
CN110282614A (zh) * 2019-06-26 2019-09-27 山东晶石大展纳米科技有限公司 一种可连续进行碳纳米管纯化的系统及方法

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114558521A (zh) * 2022-03-10 2022-05-31 无锡碳谷科技有限公司 一种分层布料移动床反应装置及使用方法
CN114558521B (zh) * 2022-03-10 2023-01-10 无锡碳谷科技有限公司 一种分层布料移动床反应装置及使用方法

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