Method and device for continuously preparing carbon material

Abstract

The invention provides a method for continuously preparing a carbon material, which comprises the following steps: 1) providing an inert substance to a reactor, the inert substance being a high temperature resistant substance and not participating in the growth reaction of the carbon material; (2) a catalyst is provided, gas is introduced into the reactor, the inert substance and the catalyst continuously move under the action of the gas, the catalyst and the gas interact at a certain temperature and grow into the carbon material in a fluidization mode, and the gas comprises carbon source gas, reducing gas and protective gas; 3) controlling the gas to separate the carbon materials with different masses from the inert substances; 4) keeping the inert substance at a certain material level in the reactor, and continuously discharging part of the carbon material; and 5) repeating the steps 2)-4) to realize continuous preparation of the carbon material. The method for preparing the carbon nanomaterial constructs a uniform fluidization field, and has the characteristics of short preparation period, low production cost and high production efficiency.

Description

Technical Field

[0001] The present invention relates to a method and device for preparing carbon materials. The method for preparing carbon nanomaterials of the present invention constructs a uniform fluidized field and has the characteristics of short preparation period, low production cost and high production efficiency. Background Art

[0002] Carbon materials represented by carbon nanotubes are widely used in new energy, chips, composite materials and other national defense strategies and livelihood fields. Fluidized bed is currently the best way to prepare carbon nanotubes in large quantities. The small particles of carbon nanotubes in the fluidized bed are easy to agglomerate, which makes the production quality uneven and continuous production difficult. The low preparation efficiency is the main challenge currently faced. At the same time, the quality of fluidization directly determines the quality of carbon nanotube growth. Poor fluidization quality makes the cluster particle size uneven, which will further aggravate the bottleneck of continuous growth.

[0003] At present, conventional methods to improve fluidization quality include changing internal components, optimizing bed structure and external vibration, but it is still difficult to change the uniformity of heat and mass transfer, which leads to the inability to grow carbon nanotubes uniformly and continuously on a large scale.

[0004] Therefore, it is urgent to propose a method to construct a fluidized field to continuously and uniformly grow carbon materials at low cost. Summary of the invention

[0005] The purpose of the present invention is to provide a method and device for continuously preparing carbon materials, which can solve the problem in the prior art that carbon materials cannot be grown continuously and uniformly in a fluidized field.

[0006] The present invention reduces the agglomeration of the growing carbon material by arranging the inert particles to space the catalyst, regulates the size of the carbon material agglomerates, and improves the fluidization quality. At the same time, the gas is controlled to separate the carbon materials of different masses from the inert substances, so that the batch continuous and stable preparation of carbon materials can be achieved. The carbon material preparation process of the present invention is simple and stable, and the process conditions are easy to control, so that batch preparation can be achieved. The carbon material obtained by the method and device of the present invention has the characteristics of high yield, large specific surface area, and high aspect ratio.

[0007] Therefore, one aspect of the present invention provides a method for continuously preparing a carbon material, the method comprising:

[0008] 1) providing an inert substance to a reactor, wherein the inert substance is a high temperature resistant substance and does not participate in the growth reaction of the carbon material;

[0009] 2) providing a catalyst and introducing a gas into a reactor, so that the inert substance and the catalyst are continuously moved under the action of the gas, and the catalyst interacts with the gas to fluidize and grow into the carbon material at a certain temperature, wherein the gas includes a carbon source gas, a reducing gas and a protective gas;

[0010] 3) controlling the gas to separate carbon materials of different qualities from inert substances;

[0011] 4) Maintaining the inert material at a certain level in the reactor and continuously discharging part of the carbon material;

[0012] 5) Repeat steps 2)-4) to achieve continuous preparation of carbon materials.

[0013] In a preferred embodiment, step 3) is performed by controlling the gas flow rate or changing the reactor tube diameter.

[0014] In a preferred embodiment, the catalyst is at least one compound selected from the group consisting of metallocene organic compounds and / or metal carbonyl organic compounds, preferably ferrocene, iron pentacarbonyl, nickel tetracarbonyl, dicobalt octacarbonyl.

[0015] In a preferred embodiment, the inert material includes at least one material selected from the group consisting of ceramics, high temperature resistant metals, high temperature alloys, rocks, gypsum, silicon dioxide, high carbon materials, and lightweight aggregates.

[0016] In a preferred embodiment, the average bulk density of the inert material is at least 1.5 times that of the carbon material.

[0017] In a preferred embodiment, the inert substance is a porous medium with a porosity of 20%-90%.

[0018] In a preferred embodiment, the inert substance is particles with an average particle size of 0.1 μm-5000 μm, preferably 100-2000 μm.

[0019] In a preferred embodiment, the carbon source gas includes at least one gas selected from the group consisting of propylene, ethylene, propane, carbon monoxide, carbon dioxide and methane; and / or the reducing gas includes at least one gas selected from the group consisting of hydrogen, carbon monoxide; and / or the protective gas includes nitrogen, argon; and / or the carbon material is carbon nanotubes or graphene.

[0020] Another aspect of the present invention provides an apparatus for continuously preparing carbon materials, the apparatus comprising a main reactor for performing CVD reaction and a collector for collecting carbon materials, the main reactor having an input end, an outflow end and a reactor body, the reactor body comprising a reaction zone and a separation zone, gas and catalyst are provided to the reaction zone through the input end; the outflow end is located at the upper part of the separation zone, and the separation zone is connected to the collector through the outflow end via a connecting pipe;

[0021] The collector comprises a filter, and the filter is used to separate the carbon material from the tail gas discharged from the main reactor.

[0022] In a preferred embodiment, the main reactor is a fluidized bed reactor having a distribution plate, wherein the inert substance and the carbon material are located on the same side of the distribution plate.

[0023] In a preferred embodiment, the main reactor further comprises a conical bottom, and the conical bottom is a conical structure, and preferably the angle of the conical bottom is 5° to 50°.

[0024] Another aspect of the present invention provides a carbon material prepared by the method of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention is described below in conjunction with the accompanying drawings.

[0026] In the attached figure:

[0027] Figure 1 is a schematic diagram of a conical fluidized bed main reactor according to one embodiment of the present invention, wherein the separation zone and the reaction zone have different pipe diameters;

[0028] Figure 2 is a schematic diagram of a conical fluidized bed main reactor according to one embodiment of the present invention, wherein the separation zone has the same pipe diameter as the reaction zone;

[0029] Figure 3 is a schematic diagram of a cylindrical fluidized bed main reactor according to one embodiment of the present invention, wherein the separation zone and the reaction zone have different pipe diameters, and the reaction zone has a distribution plate;

[0030] Figure 4 is a schematic diagram of a conical fluidized bed main reactor and a continuous collection device according to one embodiment of the present invention;

[0031] Figure 5 It is a schematic diagram of the fluidization of spherical particles in a conical fluidized bed with a distribution plate and the continuous growth of carbon nanotubes;

[0032] Figure 6 It is a schematic diagram of the fluidization of non-spherical particles and the continuous growth of carbon nanotubes in a distributed plate conical fluidized bed;

[0033] Figure 7 It is a schematic diagram of the fluidization of porous media and the continuous growth of carbon nanotubes in a distributed plate conical fluidized bed;

[0034] Figure 8 is a schematic diagram of a non-distributor plate type non-conical or flat bottom fluidized bed according to one embodiment of the present invention, wherein the catalyst is added through an input port located at the top of the reactor; DETAILED DESCRIPTION

[0035] A method for continuously preparing a carbon material, the method comprising:

[0036] 1) providing an inert substance to a reactor, wherein the inert substance is a high temperature resistant substance and does not participate in the growth reaction of the carbon material;

[0037] 2) providing a catalyst and introducing a gas into a reactor, so that the inert substance and the catalyst are continuously moved under the action of the gas, and the catalyst interacts with the gas to fluidize and grow into the carbon material at a certain temperature, wherein the gas includes a carbon source gas, a reducing gas and a protective gas;

[0038] 3) controlling the gas to separate carbon materials of different qualities from inert substances;

[0039] 4) Maintaining the inert material at a certain level in the reactor and continuously discharging part of the carbon material;

[0040] 5) Repeat steps 2)-4) to achieve continuous preparation of carbon materials.

[0041] The following is a description of the method for continuously preparing carbon materials:

[0042] In the present invention, the term "carbon material" includes at least one carbon nanotube or graphene. The preparation of different carbon materials can be achieved by fine-tuning the catalyst elements and reaction conditions.

[0043] (1) Provide inert substances

[0044] The inert material is a high temperature resistant material and does not participate in the growth reaction of the carbon material. The present invention can reduce the agglomeration of the growing carbon material by setting the inert material particles to space the catalyst, regulate the size of the carbon material, such as the carbon nanotube agglomerate, and increase the fluidization quality. The inert material includes spherical particles or non-spherical materials, and the non-spherical materials include porous medium materials, which are in a whole or dispersed state, and reciprocate along the length direction of the fluidized bed or are in a free fluidization state under the action of the gas source.

[0045] The inert material includes at least one selected from the group consisting of ceramics, high temperature resistant metals, high temperature alloys, rocks, gypsum, silicon dioxide, high carbon materials, and light aggregates. The ceramics include but are not limited to alumina, zirconium oxide, and titanium oxide. The rocks include but are not limited to marble, granite, and the like. The high temperature resistant metals include but are not limited to refractory metals such as tungsten, molybdenum, tantalum, niobium, vanadium, chromium, titanium, and zirconium. The high temperature alloys include but are not limited to chromium-nickel-molybdenum alloys, chromium-manganese-molybdenum alloys, and the like. The high carbon materials include but are not limited to graphene, carbon black, CNT, and activated carbon. The light aggregates can be divided into industrial waste residue light aggregates according to their sources, such as fly ash ceramsite, self-combustion coal gangue, expanded slag beads, coal slag and its light sand; natural light aggregates, such as pumice, volcanic slag and its light sand; artificial light aggregates, such as shale ceramsite, clay ceramsite, expanded perlite and its light sand. The inert material can also include composite materials, such as carbon-carbon composite materials or ceramic-based composite materials, minerals or processed minerals, such as perlite and pumice.

[0046] Specific examples of the inert substance include hollow glass microspheres, floating beads, hollow ceramic microspheres, perlite, natural zeolite, artificial zeolite, molecular sieves, diatomaceous earth, pumice, expanded vermiculite, lightweight refractory materials, carbon black, activated carbon, and coconut shell charcoal.

[0047] Most preferably, the inert substance is at least one substance selected from the group consisting of high carbon substances, coconut shell carbon, alumina particles, floating beads particles and perlite particles.

[0048] In a preferred embodiment, the average bulk density of the inert substance is at least 1.5 times that of the carbon material. Since the inert substance has a high bulk density and a large weight, while the generated carbon material has a low density and a light weight, the inert substance and the carbon material can be separated by gas control in the separation step.

[0049] In a preferred embodiment, the inert substance is a porous medium with a porosity of 30-90%.

[0050] In a preferred embodiment, the inert substance is a non-spherical or spherical particle with an average particle size of 0.1 μm-5000 μm, preferably 100-2000 μm. Preferably, the inert substance is a non-spherical or spherical particle, and a stepped stratified fluidization can be formed in the fluidized bed by regulating the shape, density and size of the spherical particles. In a preferred embodiment, the inert substance is a uniform spherical particle of a plurality of different particle sizes, and the particle size is 30-150 mesh.

[0051] The method for providing the inert substance of the present invention is not particularly limited and may be any conventional method known in the art as long as the purpose of the present invention can be met.

[0052] (2) providing a catalyst and introducing a gas into a reactor, so that the inert substance and the catalyst continue to move under the action of the gas, and the catalyst interacts with the gas to fluidize and grow into the carbon material at a certain temperature, wherein the gas includes a carbon source gas, a reducing gas, and a protective gas.

[0053] Gas and catalyst are provided into the reactor from the input end, and the gas and catalyst can be independently input from the input end, or the gas and catalyst can be mixed and then input. The independent input method of the catalyst includes at least one of the following methods: direct input, spray input mixed with liquid, and gas co-introduction. The independent input means that the catalyst and the gas source are input separately through their own pipelines. Direct input means that the catalyst is input separately, spray input mixed with liquid means that the catalyst is mixed with liquids such as water and then input into the fluidized bed in a spray form, and gas co-introduction means that the catalyst is mixed with inert gases such as nitrogen and then input into the fluidized bed. The present invention has no particular restrictions on the input method of gas and catalyst, and can be carried out by conventional input methods in the field, as long as the purpose of the present invention can be met.

[0054] The gas includes a carbon source gas, a reducing gas and a protective gas. The carbon source gas is a hydrocarbon or alcohol mobile phase. Preferably, the carbon source gas includes at least one gas selected from the group consisting of propylene, ethylene, propane, carbon monoxide, carbon dioxide and methane; more preferably propylene or ethylene. Preferably, the reducing gas includes at least one gas selected from the group consisting of hydrogen and carbon monoxide. Preferably, the protective gas includes nitrogen and argon. In the present invention, the gas may also include a gasified liquid phase substance.

[0055] The catalyst may be a catalyst commonly used in the art for catalyzing a carbon source to generate a carbon material through a CVD reaction. The catalyst includes a powder catalyst and a liquid catalyst. The powder catalyst includes at least one of iron, cobalt, nickel and their precursors, and the liquid catalyst precursor includes a metallocene organic compound and / or a carbonyl metal organic compound, preferably ferrocene, pentacarbonyl iron, tetracarbonyl nickel, and octacarbonyl dicobalt. In a preferred embodiment of the present invention, the catalyst includes at least one compound selected from the group consisting of a metallocene organic compound and / or a carbonyl metal organic compound, preferably ferrocene, pentacarbonyl iron, tetracarbonyl nickel, and octacarbonyl dicobalt. The metallocene organic compound and / or the carbonyl metal organic compound are dispersed in a low temperature zone to form uniform nano-scale catalyst particles, and a few-wall or single-wall carbon material can be obtained without consuming more processes and costs to prepare the catalyst.

[0056] The certain temperature is at least the temperature at which the carbon material grows. A heating device may be provided outside the reaction zone to provide the set temperature required for the growth of the carbon material. The temperature range is 500-1500° C. In the presence of an inert substance in a fluidized state, the catalyst and the gas interact with each other under the temperature range to fluidize and grow into the carbon material.

[0057] (3) controlling the gas to separate carbon materials of different masses from inert substances;

[0058] Since the generated carbon material and inert substance have different weights, the carbon material and the inert substance can be separated by controlling the gas, and the lighter carbon material leaves the reactor under the entrainment of the gas flow, while the heavier inert substance remains in the reactor body.

[0059] In the present invention, the separation of the carbon material from the inert particles can be achieved by controlling the flow rate or changing the diameter of the main tube.

[0060] The flow rate control refers to achieving different separation effects by changing different intake speeds, including setting pulse intake and sinusoidal function intake.

[0061] Changing the main body tube diameter means setting fluidized bed tube diameters of different diameters under the condition of constant gas source flow rate to achieve separation of the carbon material from the inert substance. Preferably, the separation zone tube diameter is set larger than the reaction zone diameter, which is conducive to separation and sedimentation.

[0062] 4) Maintain inert materials in the reactor and continuously discharge part of the carbon material

[0063] The inert material is kept in the reactor, and the generated carbon material is discharged from the reactor through the outflow end. The outflow end can be connected to the collector through a connecting pipe to achieve a better separation effect.

[0064] 5) Repeat steps 2)-4) to achieve continuous preparation of carbon materials.

[0065] Repeat steps (d)-(f) to maintain continuous feeding of the catalyst and gas and continuous discharge of the carbon material in the reactor to achieve continuous preparation of the carbon material.

[0066] Another aspect of the present invention provides an apparatus for continuously preparing carbon materials, the apparatus comprising a main reactor for performing a CVD reaction and a collector for collecting carbon materials, the main reactor having an input end, an outflow end and a reactor body, the reactor body comprising a reaction zone and a separation zone, gas and catalyst being provided to the reaction zone through the input end; the outflow end being located at the upper part of the separation zone, the separation zone being connected to the collector through the outflow end via a connecting pipe;

[0067] The collector comprises a filter, and the filter is used to separate the carbon material from the tail gas discharged from the main reactor.

[0068] The specific components of the device for continuously preparing carbon materials are described below:

[0069] (1) Main Reactor

[0070] In the present invention, the main reactor refers to a reactor suitable for preparing carbon nanotubes by CVD reaction using a catalyst to catalyze the cracking of a carbon source. In this reactor, at a suitable temperature, such as 500-1100°C, preferably 650-900°C, and more preferably 700-800°C, the carbon source grows carbon nanotubes on a catalyst carrier under the action of the catalyst.

[0071] In the present invention, the main reactor may be a fluidized bed reactor. Preferably, the aspect ratio of the height to the diameter of the reactor is 5-25:1, preferably 10-20:1, and more preferably 12-15:1. The reactor may be a cylindrical reactor or a conical reactor. Preferably, the fluidized bed reactor is a conical reactor with a conical bottom structure, and the cone angle of the cone bottom is preferably 5° to 50°.

[0072] The main reactor comprises an input end, an outflow end and a reactor body, wherein the reactor body comprises a reaction zone and a separation zone. The input end can be respectively set as a gas input end and a catalyst input end, the gas input end can be set at the bottom of the reactor, and the catalyst input end can be combined with the gas input end or set separately.

[0073] The gas enters the main reactor through a gas input port located at the bottom of the main reactor. There is no particular restriction on the form of the input gas, and the carbon source gas, reducing gas and / or protective gas can be introduced in the form of a mixed gas, or a certain volume of carbon source gas, reducing gas and / or protective gas can be introduced in sequence.

[0074] In the present invention, the protective gas input end and the carbon source gas input end can be separately arranged, or combined for feeding. Preferably, the gas inlet includes a carbon source gas input end and a protective gas input end, wherein the carbon source gas input end and the protective gas input end are arranged at multiple points at the bottom of the main reactor, which is conducive to fluidized reaction and heat conduction.

[0075] The catalyst input end can be arranged at any position of the reaction zone of the main reactor, and the catalyst input end can be arranged in multiple layers and / or multiple points in the same layer in the main reactor, which is conducive to fluidized reaction and heat conduction. In the main reactor of the present invention, the reaction zone and the separation zone are connected, the separation zone is located above the reaction zone, and the diameter of the separation zone is at least equal to that of the reaction zone. Preferably, the diameter of the separation zone is larger than the diameter of the reaction zone. Preferably, the diameter of the separation zone is 1-5 times the diameter of the reaction zone.

[0076] The outflow end is arranged at one side of the separation zone of the main reactor, located at the upper part of the separation zone, and the separation zone is connected with the collector through the outflow end via a connecting pipe.

[0077] In the present invention, there is no particular limitation on the types of the input end, the outflow end, and the feeding device, as long as it is a feeding device suitable for feeding the catalyst and the gas.

[0078] The main reactor of the present invention is preferably a fluidized bed reactor with a distribution plate, wherein the inert substance and the carbon material are located on the same side of the distribution plate. The aperture of the distribution plate is at least smaller than that of the inert substance, so that the inert substance is located above the distribution plate, and the fluid is distributed or dispersed on the plate in a predetermined manner. In a cylindrical or conical fluidized bed with a distribution plate, it is preferred to input the catalyst and the gas independently, and the input ends of the two substances are respectively located on both sides of the distribution plate, the catalyst input is located on the upper side of the distribution plate, and the gas input is preferably located on the lower side of the distribution plate.

[0079] Preferably, the main reactor further comprises a cone bottom, and the cone bottom is a conical structure. Preferably, the main reactor is a cone bottom with a conical structure at the bottom, and the cone bottom is a conical structure, and preferably the angle of the cone bottom is 5° to 50°.

[0080] Preferably, a heating device is provided outside the reaction zone to provide a set temperature required for the growth of the carbon material.

[0081] (2) Collector

[0082] In the present invention, the carbon material is continuously collected in the collector from the separation zone of the reactor through the connecting pipe. The collector includes at least a filter, and the filter is used to separate the carbon material from the tail gas discharged from the main reactor. The filter includes a filter screen, a metal filter, a ceramic filter, etc.

[0083] There is no particular limitation on the collector and filter suitable for use in the present invention, including but not limited to temperature-resistant filter bags, stainless steel filters, etc., as long as the purpose of collecting and filtering carbon materials of the present invention can be achieved.

[0084] The present invention reduces the agglomeration of the growing carbon material by setting inert particles to space the catalyst, regulates the size of the carbon nanotube agglomerates, and improves the fluidization quality; at the same time, it is conducive to cleaning the distribution plate to avoid clogging; further increases the uniformity of the contact temperature between particles, making the growth more uniform; because the particle size or density of the inert material particles is greater than the carbon material agglomerates, the small particles can be better fluidized under the drive of the large particles, and the gas source is controlled to separate materials of different masses to achieve the continuity of the carbon material. The technical solution of the present invention can solve the problem that the prior art cannot uniformly grow the carbon material continuously.

[0085] The carbon material prepared by the method of the present invention has the advantages of high yield, large specific surface area and high aspect ratio. The process of the present invention is simple, the conditions are easy to control, the product stability is good, the production efficiency is significantly improved, and continuous batch production can be realized.

[0086] The specific implementation of the present invention is described in detail below with reference to the accompanying drawings:

[0087] Figure 1 A schematic diagram of a conical fluidized bed main reactor according to an embodiment of the present invention is shown, wherein the conical fluidized bed main reactor includes a main body 102 and a conical bottom 101, the main body 102 includes a reaction zone 1022 and a separation zone 1021, the reaction zone 1022 and the separation zone 1021 are connected, the diameter of the separation zone 1021 is larger than the diameter of the reaction zone 1022; a heating device 15 is provided on the outside of the reaction zone 1022 to provide the set temperature required for the growth of the carbon material.

[0088] Figure 2 A schematic diagram of a conical fluidized bed main reactor according to an embodiment of the present invention is shown, wherein the conical fluidized bed main reactor includes a main body and a conical bottom 11, the main body includes a reaction zone 1022 and a separation zone 1021, the reaction zone 1022 and the separation zone 1021 are connected, and the diameter of the separation zone 1021 is the same as that of the reaction zone 1022.

[0089] Figure 3 A schematic diagram of a cylindrical fluidized bed main reactor according to one embodiment of the present invention is shown, wherein the separation zone and the reaction zone have different pipe diameters, wherein the reaction zone has a distribution plate 104 , and gas and catalyst are input into the reactor from an input end 11 .

[0090] Figure 4 A schematic diagram of a conical fluidized bed main reactor and a continuous collection device according to one embodiment of the present invention is shown, wherein the diameter D1 of the separation zone in the fluidized bed reactor 10 is larger than the diameter D2 of the reaction zone, the input end 11 is arranged as a gas input end 111 and a catalyst input end 112, the separation zone is connected to the collector 13 through a connecting pipe 12, and the collector 13 has a filter 131.

[0091] Figure 5 A schematic diagram is shown of the fluidization of spherical particles and the continuous growth of carbon nanotubes in a conical fluidized bed with a distribution plate, wherein the fluidized bed reactor 10 is divided into a conical bottom 101, a reactor body 102, an outflow end 103, spherical inert particles 14 are loaded in the reaction zone, and the carbon material obtained by the reaction enters the collector 13 from the outflow end 103 through a connecting pipe.

[0092] Figure 6 A schematic diagram showing the fluidization of non-spherical particles and the continuous growth of carbon nanotubes in a distribution plate conical fluidized bed is shown. The reaction zone has a distribution plate 104, and non-spherical inert particles 14 are loaded above the distribution plate. The carbon material 16 obtained by the reaction is collected in a collector.

[0093] Figure 7 A schematic diagram showing the fluidization of a porous medium in a distributed plate conical fluidized bed and the continuous growth of carbon nanotubes is shown, wherein a porous medium 14 is loaded in the reaction zone.

[0094] Figure 8 A schematic diagram of a non-distributor plate type non-conical or flat-bottom fluidized bed according to one embodiment of the present invention is shown, the catalyst is added through an input port 112 located at the top of the reactor, and the gas is input through an input port 111 located at the bottom of the reaction zone.

[0095] In a specific embodiment, an inert substance is placed in the reaction zone, an inert gas is introduced into the fluidized bed through the input end, the temperature is raised to a set temperature, catalyst particles are continuously input and gas is introduced to continuously grow the carbon material; the gas source velocity is controlled to separate the carbon material from the inert substance; the carbon material enters a collector through the outflow end of the fluidized bed, and the carbon material is continuously collected.

[0096] The present invention will be further described below in conjunction with specific examples. It should be understood that these examples are only used to illustrate the present invention and are not intended to limit the scope of the present invention. For the experimental methods in the following examples where specific conditions are not specified, conventional conditions are usually used, or the conditions recommended by the manufacturer. Ratios and percentages are based on molar amounts unless otherwise specified.

[0097] Raw material source and preparation:

[0098] (1) Inert substances:

[0099] Ceramic spherical particles (particle size 500μm-1000μm), products of Shandong Qitai Industrial Ceramics Co., Ltd., specifications: 0.5-1mm;

[0100] High carbon material (particle size 200 μm-400 μm), product of Shandong Dazhan Nanomaterial Co., Ltd., number: GTY-301;

[0101] Alumina (particle size 0.2mm-3mm), product of Shandong Qitai Industrial Ceramics Co., Ltd., specifications: 0.5-1mm, 1mm, 2mm, 3mm;

[0102] Floating beads 40-100 mesh, products of Dongying Wanjia Energy Saving Materials Co., Ltd., specifications: 40-100 mesh;

[0103] Perlite 70-90 mesh, a product of Xinyang City Shihe District Houpu Mining Materials Factory, specification: 70-90 mesh;

[0104] The particle size of coconut shell carbon particles is 10-60 mesh, and it is a product of Changge Tanernuo Catalytic Technology Co., Ltd. with a specification of 30-110 mesh.

[0105] (2) Catalyst

[0106] Iron nitrate, cobalt nitrate, aluminum nitrate, ammonia water, and ammonium carbonate were all purchased from Zibo Aiken Economic and Trade Co., Ltd.; purified water was produced by Shandong Dazhan Nanomaterials Co., Ltd. after distillation and purification.

[0107] The micronized catalyst was prepared by the following method:

[0108] Mix ferric nitrate, cobalt nitrate, aluminum nitrate and purified water according to the proportion and dissolve them until they are uniform and free of particles to form an acid solution;

[0109] Ammonia water, ammonium carbonate and purified water are mixed according to the proportions, dissolved evenly and without particles, to form lye;

[0110] Precipitation titration: Control the pH titration by controlling the flow rate of the acid and alkali solution. After the titration is completed, age for 2-4 hours;

[0111] Filter pressing: The mixture after the titration reaction is passed through a plate and frame or centrifuge to filter out most of the water and collect the filter cake;

[0112] Drying and roasting: The filter cake is dried and roasted at high temperature. After roasting, it is crushed into particles with uniform particle size and packaged.

[0113] (3) Gas:

[0114] Hydrogen: purchased from Zibo Anze Special Gas Co., Ltd.

[0115] Propylene: purchased from Shandong Jingbo Petrochemical Co., Ltd.

[0116] Nitrogen: purchased from Praxair (Qingdao) Industrial Gas Co., Ltd.

[0117] Embodiment 1:

[0118] Example 1 uses Figure 4The device shown in the figure is used to place ceramic spherical particles (particle size 100 μm-300 μm) into the fluidized bed. Then, nitrogen is introduced into the fluidized bed 10 from the gas input end 111 for 5-20 minutes (1000 L / min) to drive away the residual oxygen in the fluidized bed, so that the ceramic spherical particles are in a continuous fluidized state, the temperature is raised to the set temperature of 660 degrees Celsius and stabilized, the fluidized bed is controlled to be set to input a micro-powdered catalyst (50-80 mesh) from the catalyst input end 112, and then a mixed gas of hydrogen, propylene and nitrogen in a ratio of 1:6:7 is input from the gas source input end 111, and the gas speed is controlled to be 320 L / h to realize the fluidized growth of carbon nanotubes, and separation is realized in the separation zone. The carbon nanotubes leave the fluidized bed from the outflow end and enter the collector 13 through the connecting pipe 12 to collect the carbon nanotubes. The tail gas leaves the collector through the filter 131. The continuous introduction of catalyst and gas source realizes the continuous and uniform preparation of carbon nanotubes.

[0119] Embodiment 2:

[0120] Example 2 uses Figure 4 The device shown in the figure is used to put 20 kg of high carbon material (particle size 200 μm-400 μm) into the fluidized bed, and then nitrogen is input into the fluidized bed 10 from the gas source input end 111 for 5-20 minutes (500 L / min) to drive away the residual oxygen in the fluidized bed, so that the high carbon material is in a continuous fluidized state, and the temperature is raised to the set temperature of 660 degrees Celsius and stabilized, and the fluidized bed is controlled to input (80-100 mesh) micro-powdered catalyst from the catalyst input end 112, and then a mixed gas of hydrogen, propylene and nitrogen in a ratio of 1:7:10 is input from the gas source input end 111, and the gas velocity is controlled to realize the fluidized growth of carbon nanotubes, and separation is realized in the separation zone, and the carbon nanotubes leave the fluidized bed from the outflow end, and enter the collector 13 through the connecting pipe 12 to collect the carbon nanotubes. The tail gas leaves the collector through the filter 131. The catalyst (0.9-1.1 Kg / h) and gas source (900 L / min) are continuously introduced to achieve continuous and uniform preparation of carbon nanotubes.

[0121] Embodiment 3:

[0122] Example 3 uses Figure 4The device shown in the figure is used to put 1-30g of aluminum oxide (particle size 0.2mm-3mm) into the fluidized bed. Then, nitrogen is input into the fluidized bed 10 from the gas source input end 111 for 5-20 minutes (100L / h) to drive away the residual oxygen in the fluidized bed, so that the aluminum oxide is in a continuous fluidized state, and the temperature is raised to the set temperature of 670 degrees Celsius and stabilized. The fluidized bed is controlled to input (80-100 mesh) micro-powdered catalyst from the catalyst input end 112, and then a mixed gas of hydrogen, propylene and nitrogen in a ratio of 5:8:10 is input from the gas source input end 111. The gas velocity is controlled to realize the fluidized growth of carbon nanotubes, and separation is realized in the separation zone. The carbon nanotubes leave the fluidized bed from the outflow end and enter the collector 13 through the connecting pipe 12 to collect the carbon nanotubes. The tail gas leaves the collector through the filter 131. The catalyst and gas source (230L / h) are continuously introduced to realize the continuous and uniform preparation of carbon nanotubes.

[0123] Embodiment 4:

[0124] Example 4 uses Figure 4 The device shown in the figure is used to carry out the process, and floating beads of 40-100 mesh (total mass 10g) are placed in the fluidized bed. Then, nitrogen is input into the fluidized bed 10 from the gas source input end 111 for 5-20 minutes (100-200L / h) to drive away the residual oxygen in the fluidized bed, so that the alumina is in a continuous fluidized state, and the temperature is raised to the set temperature of 670 degrees Celsius and stabilized. The fluidized bed is set to input a micro-powdered catalyst (80-100 mesh) from the catalyst input end 112, and then a mixed gas of hydrogen, propylene and nitrogen in a ratio of 5:8:10 is input from the gas source input end 111, and the gas velocity is controlled to realize the fluidized growth of carbon nanotubes, and separation is realized in the separation zone. The carbon nanotubes leave the fluidized bed from the outflow end and enter the collector 13 through the connecting pipe 12 to collect the carbon nanotubes. The tail gas leaves the collector through the filter 131. The catalyst and gas source (280L / h) are continuously introduced to realize the continuous and uniform preparation of carbon nanotubes.

[0125] Example 5

[0126] Example 5 uses Figure 4The device shown in the figure is used to place pearlite of 70-90 mesh (total mass 10g) into the fluidized bed, and then nitrogen is input into the fluidized bed 10 from the gas source input end 111 for 5-20 minutes (150L / h) to drive away the residual oxygen in the fluidized bed, so that the alumina is in a continuous fluidized state, the temperature is raised to the set temperature of 670 degrees Celsius and stabilized, the fluidized bed is controlled to input (80-100 mesh) micro-powdered catalyst from the catalyst input end 112, and the reducing gas (hydrogen) is input for 5min (50L / h), after reduction, the mixed gas of propylene and nitrogen in a ratio of 8:15 is input from the gas source input end 111, the gas velocity is controlled to realize the fluidized growth of carbon nanotubes, and separation is realized in the separation zone, the carbon nanotubes leave the fluidized bed from the outflow end, and enter the collector 13 through the connecting pipe 12 to collect the carbon nanotubes. The tail gas leaves the collector through the filter 131. The catalyst and gas source (230 L / h) were continuously introduced to achieve continuous and uniform preparation of carbon nanotubes.

[0127] Example 6

[0128] Example 6 uses Figure 4 The device shown in the figure is carried out, coconut shell carbon particles (particle size 10-60 mesh) are placed in the fluidized bed, and then nitrogen is input into the fluidized bed 10 from the gas source input end 111 for 5-20 minutes (1000L / min) to drive away the residual oxygen in the fluidized bed, ensure an oxygen-free environment and make the unloaded catalyst particles in a continuous fluidized state, increase the temperature to a set temperature of 660 degrees Celsius and stabilize, control the fluidized bed setting to input (50-80 mesh) micro-powdered catalyst from the catalyst input end 112, and then input a mixed gas of hydrogen, propylene and nitrogen in a ratio of 1:6:7 from the gas source input end 111, control the gas velocity to achieve fluidized growth of carbon nanotubes, and achieve separation in the separation zone, the carbon nanotubes leave the fluidized bed at the first end 103 of the fluidized bed, and enter the collector 13 through the connecting pipe 12 to collect the carbon nanotubes. The tail gas leaves the collector through the filter 131. Continuous introduction of catalyst and gas source realizes the continuous and uniform preparation of carbon nanotubes.

[0129] Comparative Example

[0130] The comparative example also uses Figure 4The device shown is carried out, nitrogen is input into the fluidized bed 10 from the gas source input end 111 for 5-20 minutes (100L / h) to drive away the residual oxygen in the fluidized bed, the temperature is raised to the set temperature of 670 degrees Celsius and stabilized, the fluidized bed is set to input (80-100 mesh) micro-powdered catalyst from the catalyst input end 112, and then a mixed gas of hydrogen, propylene and nitrogen in a ratio of 5:8:10 is input from the gas source input end 111, the gas velocity is controlled to achieve fluidized growth of carbon nanotubes, and separation is achieved in the separation zone, the carbon nanotubes leave the fluidized bed at the first end 103 of the fluidized bed, and enter the collector 13 through the connecting pipe 12 to collect the carbon nanotubes. The tail gas leaves the collector through the filter 131. The catalyst and gas source (230L / h) are continuously introduced to achieve continuous and uniform preparation of carbon nanotubes.

[0131] Product performance testing

[0132] (1) Four-probe resistivity:

[0133] The resistivity of the product is tested according to the national standard GB / T 39978-2021 Nanotechnology Carbon Nanotube Powder Resistivity Four-Probe Method;

[0134] (2) Specific surface area test:

[0135] According to the national standard GB / T 10722, the specific surface area of ​​the product is tested using a nitrogen physical adsorption instrument;

[0136] (3) Microscopic morphology test:

[0137] The diameter of carbon nanotubes was determined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM);

[0138] (4)Magnification

[0139] The ratio is calculated by the output of carbon material product / the input of carbon source material.

[0140] The performance of the products obtained in Examples 1-6 and Comparative Examples was tested, and the results are shown in the following table:

[0141]

[0142] From the above results, it can be seen that the addition of inert substances plays a role in fluidization. Without the addition of inert substance particles, the yield of carbon materials is extremely low. After adding inert substances, the yield increases, the specific surface area increases, and the resistivity decreases. The best results are obtained by using high carbon substances, alumina, floating beads, perlite and coconut shell carbon as inert substances.

[0143] The process method for preparing carbon materials of the present invention, the amount of raw materials used and the process parameters are not limited to the above-mentioned embodiments. After reading the above teaching content of the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the claims attached to this application.

Claims

1. A method for continuously preparing a carbon material, the method comprising: 1) providing an inert substance to a reactor, wherein the inert substance is a high temperature resistant substance and does not participate in the growth reaction of the carbon material; 2) providing a catalyst and introducing a gas into a reactor, so that the inert substance and the catalyst are continuously moved under the action of the gas, and the catalyst and the gas interact with each other at a certain temperature to fluidize and grow into the carbon material, wherein the gas includes a carbon source gas, a reducing gas and a protective gas; 3) controlling the gas to separate carbon materials of different qualities from inert substances; 4) Maintaining the inert material at a certain level in the reactor and continuously discharging part of the carbon material; 5) Repeat steps 2)-4) to achieve continuous preparation of carbon materials.

2. The method of claim 1, wherein step 3) is performed by controlling the gas flow rate or changing the reactor diameter.

3. The method of claim 1, wherein the catalyst is at least one compound selected from the group consisting of metallocene organic compounds and / or metal carbonyl organic compounds, preferably ferrocene, iron pentacarbonyl, nickel tetracarbonyl, dicobalt octacarbonyl.

4. The method of claim 1, wherein the inert material comprises at least one selected from the group consisting of ceramics, high temperature resistant metals, high temperature alloys, rocks, gypsum, silica, high carbon materials, lightweight aggregates; and / or The average bulk density of the inert material is at least 1.5 times that of the carbon material.

5. The method of claim 1, wherein: The inert substance is a porous medium with a porosity of 20%-90%; and / or The inert substance is a particle with an average particle size of 0.1 μm-5000 μm, preferably 100-2000 μm.

6. The method of claim 1, wherein the carbon source gas comprises at least one gas selected from the group consisting of propylene, ethylene, propane, carbon monoxide, carbon dioxide and methane; and / or the reducing gas comprises at least one gas selected from the group consisting of hydrogen, carbon monoxide; and / or the protective gas comprises nitrogen, argon; and / or the carbon material is a carbon nanotube or graphene.

7. An apparatus for the method according to any one of claims 1 to 6, comprising a main reactor for performing a CVD reaction and a collector for collecting carbon materials, the main reactor having an input end, an outflow end and a reactor body, the reactor body comprising a reaction zone and a separation zone, and gas and catalyst are provided to the reaction zone through the input end; The outflow end is located at the upper part of the separation zone, and the separation zone is connected with the collector through the outflow end via a connecting pipe; The collector comprises a filter, and the filter is used to separate the carbon material from the tail gas discharged from the main reactor.

8. The apparatus according to claim 7, wherein the main reactor is a fluidized bed reactor having a distribution plate, wherein the inert substance and the carbon material are located on the same side of the distribution plate.

9. The device according to claim 7 or 8, wherein the main reactor is a conical reactor with a conical bottom, and preferably the angle of the cone bottom is 5° to 50°.

10. A carbon material prepared by the method according to any one of claims 1 to 6.

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