JP4690748B2 - Nanocarbon material production equipment - Google Patents

Description

  The present invention relates to a carbon material manufacturing apparatus capable of manufacturing a nanocarbon material efficiently and with high purity.

  The carbon nanotube is a tubular carbon polyhedron having a structure in which a graphite (graphite) sheet is closed in a cylindrical shape. The carbon nanotube includes a multi-layer nanotube having a multilayer structure in which a graphite sheet is closed in a cylindrical shape, and a single-wall nanotube having a single-layer structure in which a graphite sheet is closed in a cylindrical shape.

  One multi-walled nanotube was discovered by Iijima in 1991. That is, it was discovered that multi-walled nanotubes exist in the carbon mass deposited on the cathode of the arc discharge method (Non-Patent Document 1). Since then, research on multi-walled nanotubes has been actively conducted, and in recent years, it has become possible to synthesize a large number of multi-walled nanotubes.

  In contrast, single-walled nanotubes have an inner diameter of approximately 0.4 to 10 nanometers (nm), and their synthesis was simultaneously reported in 1993 by a group of Iijima and IBM. The electronic state of single-walled nanotubes has been predicted theoretically, and it is thought that the electronic properties change from metallic properties to semiconducting properties depending on how the spiral is wound. Therefore, such single-walled nanotubes are considered promising as future electronic materials.

  Other applications of single-walled nanotubes include nanoelectronic materials, field electron emitters, highly directional radiation sources, soft X-ray sources, one-dimensional conducting materials, high thermal conducting materials, hydrogen storage materials, and the like. Further, it is considered that the use of single-walled nanotubes is further expanded by functionalization of the surface, metal coating, and inclusion of foreign substances.

Conventionally, the single-walled nanotubes described above are manufactured by mixing a metal such as iron, cobalt, nickel, or lanthanum into a carbon rod of an anode and performing arc discharge (Patent Document 1).
However, in this production method, in addition to single-walled nanotubes, multi-walled nanotubes, graphite, and amorphous carbon are mixed in the product, and not only the yield is low, but also the diameter and length of single-walled nanotubes vary. In addition, it was difficult to produce single-walled nanotubes with relatively uniform yarn diameter and yarn length in high yield.

  In addition to the arc method described above, a vapor phase pyrolysis method, a laser sublimation method, a condensed phase electrolysis method, and the like have been proposed as methods for producing carbon nanotubes (Patent Documents 2 to 4).

However, any of the production methods disclosed in these documents is a laboratory or small-scale production method, and there is a problem that the yield of the carbon material is low and the purity is particularly low.
In recent years, the use of carbon materials has been expanded, and for this reason, the advent of an apparatus that can produce carbon materials with good purity while being able to be produced efficiently in large quantities is desired.

  Therefore, the present inventors have previously proposed that carbon nanofibers are produced using a fluidized bed reactor (Patent Document 5).

S, Iijima, Nature, 354, 56 (1991) Japanese Patent Laid-Open No. 06-280116 Japanese Patent No. 3100962 JP-T-2001-520615 JP 2001-139317 A JP 2004-76197 A

  However, when producing a single-layer carbon material using a support in which an active metal is supported on a fluidized material by the fluidized bed method of Patent Document 5, the fluidized bed reactor uses a fluidized catalyst that combines a fluidized material and a catalyst. However, since the fluidized bed reactor is a single layer, it is required to improve the production efficiency.

  Further, when a single-layer carbon material is produced using a carrier carrying an active metal in a fluid material, the nanocarbon material 3 grows from the active metal 2 carried on the carrier 1 as shown in FIG. 8, for example. If impurities 4 such as amorphous or crystalline graphite are present around the active metal 2 in the course of the process, the growth of the nanocarbon material 3 may stop, which causes a problem that the purity is reduced.

  Therefore, it is desired to industrially manufacture a high-purity single-layer carbon material by, for example, a fluidized bed method.

  In view of the above circumstances, an object of the present invention is to provide a nanocarbon material manufacturing apparatus capable of continuously mass-producing nanocarbon materials by improving manufacturing efficiency.

The first invention of the present invention for solving the above-mentioned problems is a nanocarbon material for producing a nanocarbon material in a fluidized bed reactor using a fluid catalyst comprising an active metal and a carrier carrying the active metal. A supply device for supplying a fluidized catalyst that exhibits fluidity and catalysis inside the fluidized bed reactor and a carbon raw material for generating a nanocarbon material by the fluidized catalyst inside the fluidized bed reactor A nanocarbon raw material supply device, and an oxidizing gas supply device for supplying an oxidizing gas for removing amorphous carbon of the nanocarbon material into the fluidized bed reaction device , and the oxidizing gas, The lower part of the fluidized bed reactor is charged into the fluidized bed reactor, and the carbon raw material is fed from the middle part of the fluidized bed reactor. Lying in the nano-carbon material production apparatus according to claim to be introduced into the interior of the dynamic bed reactor.

  A second invention is the nanocarbon material manufacturing apparatus according to the first invention, wherein the oxidizing gas supply device is provided in a lower part of the fluidized bed reaction device.

A third invention is the nanocarbon material manufacturing apparatus according to the first or second invention , wherein the nanocarbon material is a single-layer nanocarbon tube.

  According to the present invention, it is possible to efficiently produce a nanocarbon material.

  Hereinafter, the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by this embodiment. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same.

[First Embodiment]
FIG. 1 is a schematic view of a nanocarbon material manufacturing apparatus according to this embodiment.
As shown in FIG. 1, the nanocarbon material manufacturing apparatus according to the present embodiment divides the inside of the fluidized bed reaction apparatus 11 into at least two rooms (6 rooms in the present embodiment). Is composed of a pretreatment part 13 of a fluid catalyst for producing a nanocarbon material and a nanocarbon material production part 14 which is a reaction part for producing a nanocarbon material by supplying a carbon raw material. In the present embodiment, the post-processing unit 15 is provided on the downstream side of the reaction unit 14. In this embodiment, the free board part of the fluidized bed reactor is omitted.

  The pretreatment unit 13 includes a granulating unit 12-1 for granulating the supplied catalyst 16 to a predetermined particle size, a drying unit 12-2 for drying the granulated granulating catalyst 17a, and a dried granulating catalyst. It comprises a firing unit 12-3 that combusts 17b at a predetermined temperature and a reductor 12-4 that performs a reduction process on the granulated catalyst 17c that has been combusted. An inert gas is introduced as the first gas G-1 into the granulating unit 12-1.

  In addition, in this embodiment, although it is set as four combinations of the granulation part 12-1, the drying part 12-2, the baking part 12-3, or the reduction | restoration part 12-4 as the said pre-processing part, either of these Or a combination of two or more of these. Moreover, you may make it a process part divide | segment a function as one room.

Further, the nanocarbon material production unit 14 produces a nanocarbon material 18a by reacting with a separately introduced second gas (carbon raw material gas) G-2 using the reduced granulated catalyst 17d. ing. Thereafter, impurities are removed by the third gas (oxidizing gas) G-3 in the post-processing unit 15 and then taken out to the outside as the nanocarbon material product 19. Examples of the oxidizing gas that is the third gas G-3 include water (H ₂ O) and CO ₂ .

  Each function of the pre-processing unit is independent, and an example of each processing condition is as follows.

As the catalyst 16, an active metal supported on a carrier is used, and this is granulated to a predetermined particle size by the granulating part 12-1.
Here, the particle diameter to be granulated when used in the fluidized bed system is, for example, in the range of 0.1 to 10 mm, preferably about 400 μm to 0.5 mm.
In addition, when using the granulation catalyst of the predetermined particle diameter already granulated, the granulation part 12-1 is unnecessary.

  The granulation conditions are, for example, 40 to 120 ° C. and 5 to 20 hours at 0.08 MPa to normal pressure in an air atmosphere or a nitrogen atmosphere.

Here, the active metal is any one of V, Cr, Mn, Fe, Co, Ni, Cu, and Zn, or a combination thereof.
Examples of the carrier include aluminum compounds such as alumina, sodium aluminate, alum, and aluminum phosphate; calcium compounds such as calcium oxide, calcium carbonate, and calcium sulfate; and magnesium compounds such as magnesium oxide, magnesium hydroxide, and magnesium sulfate. It is preferable to use an apatite type such as calcium phosphate or magnesium phosphate.
Here, the _{^{apatite, M 10 2+ (Z 5- O}} 4) 6 X 2 - composition mineral with M, ZO _4, each element as follows with respect to X, alone or in two or more The one that enters in a solid solution state.
M: Ca, Pb, Ba, Sr, Cd, Zn, Ni, Mg, Na, K, Fe, Al and other _{ZO 4: PO 4, AsO 4} , VO 4, SO 4, SiO 4, CO 3
X: F, OH, Cl, Br, O, I
Moreover, you may make it contain the promoter of either one or both of Mo or W in the said nano metal. This is because, by adding a small amount of the promoter such as Mo, the decomposition of the carbon raw material is promoted, the incorporation of carbon into the active metal such as iron is promoted, and the production of the nanocarbon material is promoted. .

  The drying unit 12-2 is performed at 120 ° C. for several hours at 0.01 MPa to normal pressure in an air atmosphere or a nitrogen atmosphere.

The fired portion 12-3 is a process for refining the exposed portion of the active metal. As shown in FIG. 6, the support 20 carries an active metal (for example, Fe) 21 and then fires to support 20 The active metal 21 is covered with the diffusion layer 22, and a part of the active metal 21 is covered with the diffusion layer 22, and the exposed portion of the active metal 21 is refined 23.
As a result, when a nanocarbon material is produced using a catalyst in which the exposed portion of the active metal is refined, the nanocarbon material 24 grows only from the refined active metal portion. As a result, only the thin nanocarbon material 24 can be manufactured.

The reduction treatment unit 12-4 is 200 to 800 ° C., 0.5 to 20 hours, an inert gas atmosphere such as N ₂ , Ar, or He or a reducing gas such as H ₂ or CO (gas concentration 0.1 to 50). %) At atmospheric pressure in the atmosphere.

The carbon source that is the second gas (carbon raw material gas) G-2 may be any carbon-containing compound, such as methane, ethane, propane, and hexane in addition to CO and CO _2. Alkanes, unsaturated organic compounds such as ethylene, propylene and acetylene, aromatic compounds such as benzene and toluene, organic compounds having an oxygen-containing functional group such as alcohols, ethers and carboxylic acids, polyethylene, polypropylene and the like Examples thereof include molecular materials, petroleum and coal (including coal conversion gas), but the present invention is not limited to these. In order to control the oxygen concentration, two or more oxygen-containing carbon sources CO, CO ₂ , alcohols, ethers, carboxylic acids and the like and carbon sources not containing oxygen can be supplied in combination.

  This carbon source is supplied in a gas state into the nanocarbon material production unit 14, and a uniform reaction is performed by stirring with a fluid catalyst 17d that is a fluid material, thereby growing the nanocarbon material 18a. At this time, an inert gas is separately introduced as a flowing gas (not shown) so as to satisfy a predetermined flow condition.

  A nanocarbon material is obtained by contacting a carbon raw material such as methane with a catalyst in a coexisting environment of impurity carbon decomposition products for a certain time in a temperature range of 300 ° C. to 1300 ° C., more preferably 400 ° C. to 1200 ° C. Is synthesized.

  The post-processing unit 15 supplies an oxidizing gas, which is the third gas G-3, to the downstream side of the nanocarbon material manufacturing unit 14 that is a reaction unit, and removes amorphous carbon generated during the production of the nanocarbon material. Like to do.

As shown in FIG. 7, the nanocarbon material 3 grows from the active metal 2 supported on the carrier 1. However, when impurities 4 such as amorphous carbon are generated around the active metal, the growth of the nanocarbon material 3 is increased. Stopped. In such a state, the impurities are removed by supplying the third gas G-3 made of the oxidizing gas as described above. As a result, the growth of the nanocarbon material 3 is started.
The inert gas, raw material gas and oxidizing gas are supplied into the fluidized bed reactor by a gas supply device (not shown).

  The nanocarbon material 18b whose purity has been improved by the post-processing unit 15 is sent to the outside as a nanocarbon material product 19, and the separation / recovery device 40 separates the nanocarbon material 19 and the fluid catalyst 17d accompanied therewith. I am doing so. Examples of the separation and recovery device 40 include known separation means such as a cyclone, a bag filter, a ceramic filter, and a sieve.

  Further, the nanocarbon material product 19 separated by the separation / recovery device is purified by a refining device 41 that separates the attached catalyst (for example, single- or double-walled carbon nanotubes, carbon nanocarbons). Fiber etc.) 42 is collected.

  FIG. 2 is a schematic view of a fluidized bed reactor. FIG. 2 shows an example in which two fluidized bed reactors are used. As shown in FIG. 2, a fluidized bed reactor 30-1 is constituted by the pretreatment unit 13 and the nanocarbon material production unit 14, and the pretreatment unit includes the granulation unit 12-1 and the drying unit described above. 12-2, the baking part 12-3, or the reduction part 12-4 can be implemented.

  FIG. 3 is a schematic view of another fluidized bed reactor. As shown in FIG. 3, a fluidized bed reactor 30-2 is configured from the pretreatment unit 13 and the nanocarbon material production unit 14, and the pretreatment unit 13 and the nanocarbon material production unit 14 include A heat medium 31 is provided. Thereby, it can be set as the heat source of pre-processing and nanocarbon material manufacture, without providing an external heating means.

FIG. 4 is a schematic view of another fluidized bed reactor. As shown in FIG. 4, a fluidized bed reactor 30-3 is constituted by the pretreatment unit 13 and the nanocarbon material production unit 14, and the third gas G− is contained in the nanocarbon production unit 14 as the reaction unit. 3 is an example in which nanocarbon material production and post-treatment are combined.
As a result, by introducing the third gas G-3, the production of the nanocarbon material and the separation of the nanocarbon material generated from the active metal can be performed simultaneously.

[Second Embodiment]
FIG. 5 is a schematic view of a nanocarbon material manufacturing apparatus according to the present embodiment.
As shown in FIG. 5, the nanocarbon material manufacturing apparatus uses a free catalyst unit 50 and a nanocarbon material manufacturing unit 51 to convert a nanocarbon material using a fluid catalyst including an active metal and a carrier that supports the active metal. A supply device 31 that supplies a fluidized catalyst 34 that exhibits fluidity and catalysis inside the nanocarbon material production unit 51 of the fluidized bed reactor 52, A carbon raw material supply device 32 for supplying the second gas G-2, which is a carbon raw material for generating a carbon material by the fluid catalyst 34, into the fluidized bed, and amorphous carbon generated when the nanocarbon material is generated is removed. And an oxidizing gas supply device 33 for supplying the third gas G-3, which is an oxidizing gas, into the nanocarbon material manufacturing unit 51. It is intended.

The third gas G-3 may be introduced from any position of the nanocarbon material production unit 51. For example, as shown in FIG. 5, the second gas G-2, which is a raw material gas, is fluidized into the fluidized bed. When charging from the middle part of the reactor, it may be performed from the bottom of the fluidized bed reactor.
This is to remove the amorphous carbon, which is an impurity, efficiently by introducing an oxidizing gas when the nanocarbon material convected by the flow stays in the lower part of the fluidized bed reactor. Because you can.
The post-treated nanocarbon material is sent to the outside as a nanocarbon material product 19, and the separation / recovery device 40 separates the nanocarbon material 19 and the fluid catalyst 34 accompanied with the nanocarbon material 19. It is refined by the apparatus 41 and is recovered as a nano unit pure carbon material (for example, single-walled or double-walled carbon nanotube, carbon nanofiber, etc.) 42.

  As described above, the nanocarbon material production apparatus according to the present invention is designed to reduce the size of the production apparatus by dividing the inside of one fluidized bed reactor and to perform the production of the nanocarbon material. It can be carried out efficiently and mass production of large-scale nanocarbon materials can be realized.

It is the schematic of the manufacturing apparatus of the nanocarbon material concerning 1st Embodiment. It is the schematic of a fluidized bed reaction apparatus. It is the schematic of another fluidized bed reaction apparatus. It is the schematic of another fluidized bed reaction apparatus. It is the schematic of the manufacturing apparatus of the nanocarbon material concerning 2nd Embodiment. It is the process-process schematic which refines | miniaturizes the exposed part part of an active metal. It is a nanocarbon material production | generation process schematic. It is the process schematic of the impurity generation of nanocarbon material production | generation.

DESCRIPTION OF SYMBOLS 11 Fluidized bed reactor 12-1 Granulation part 12-2 Drying part 12-3 Firing part 12-4 Reduction part 13 Pretreatment part 14 Nanocarbon material production part 15 Post-treatment part 16 Catalyst 19 Nanocarbon material product

Claims (3)

A nanocarbon material production apparatus for producing a nanocarbon material in a fluidized bed reactor using a fluid catalyst comprising an active metal and a support carrying the active metal,
A supply device for supplying fluid catalyst that exhibits the flow behavior and catalytic activity inside the fluidized bed reactor,
A nanocarbon material supply device for supplying the carbon material to produce a nano-carbon material inside the fluidized bed reactor by the fluidized catalyst,
An oxidizing gas supply device for supplying an oxidizing gas to remove the amorphous carbon inside the fluidized bed reactor of the nanocarbon material,
Equipped with, and,
Injecting the oxidizing gas from the lower part of the fluidized bed reactor into the fluidized bed reactor,
An apparatus for producing nanocarbon , wherein the carbon raw material is introduced into the fluidized bed reactor from an intermediate portion of the fluidized bed reactor . In claim 1,
An apparatus for producing a nanocarbon material, wherein the oxidizing gas supply device is provided in a lower part of the fluidized bed reaction device. In claim 1 or 2 ,
The nanocarbon material manufacturing apparatus, wherein the nanocarbon material is a single-layer nanocarbon tube.

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