KR20150143105A - Fluidized bed reactor and process for preparing carbon nanostructures using same - Google Patents

Abstract

The present invention relates to a fluidized bed reactor and, more specifically, to a fluidized bed reactor which can be used for the production of a carbon nanostructure such as a carbon nanotube. The fluidized bed reactor of the present invention comprises: a reactor main body; a dispersion plate disposed in the reactor main body; a gas supply pipe supplying reaction gas in an up flow type which allows the gas to flow toward an upper part from the bottom of the dispersion plate; a catalyst supply pipe disposed at the bottom part of the reactor main body to supply a catalyst; an internal column being shorter than the main body by height, disposed in the main body, and comprising a product discharging pipe discharging the produced carbon nanostructure and mixed gas to the outside of the main body.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluidized bed reactor, and more particularly, to a fluidized bed reactor and a carbon nanostructure using the same.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluidized bed reactor and a method for producing the same. More particularly, the present invention relates to a fluidized bed reactor that can be used for producing a carbon nanostructure, such as a carbon nanotube.

Fluidized bed reactors are reactor devices that can be used to perform a variety of multiphase chemical reactions. In a fluidized bed reactor, a fluid (gas or liquid) reacts with a solid material in a particulate state, typically the solid material is a catalyst having the shape of a small sphere and the fluid is flowed at a rate sufficient to float the solid material So that the solid material behaves like a fluid.

On the other hand, carbon nanostructures (CNS) refer to nano-sized carbon structures having various shapes such as nanotubes, nanofibers, fullerenes, nanocons, nanohorns, and nano-rods and have various excellent properties It is highly utilized in various technical fields. Carbon nanotubes (CNTs), which are typical carbon nanostructures, are carbon nanotubes (CNTs) having three neighboring carbon atoms bonded to each other in a hexagonal honeycomb structure to form a carbon plane, and the carbon plane is cylindrically shaped to have a tube shape. Carbon nanotubes have a characteristic of being a conductor or a semiconductor according to the structure, that is, the diameter of a tube, and can be widely applied in various technical fields, and thus, they are popular as new materials. For example, the carbon nanotube can be applied to an electrode of an electrochemical storage device such as a secondary cell, a fuel cell or a supercapacity, an electromagnetic wave shielding, a field emission display, or a gas sensor.

The carbon nanostructure can be produced by, for example, an arc discharge method, a laser evaporation method, or a chemical vapor deposition method. In the chemical vapor deposition method among the above-mentioned manufacturing methods, metal catalyst particles and a hydrocarbon-based raw material gas are dispersed and reacted in a fluidized bed reactor at a high temperature to produce a carbon nanostructure. That is, the metal catalyst reacts with the raw material gas while floating in the fluidized bed reactor by the raw material gas to grow the carbon nanostructure.

A method for manufacturing a carbon nanostructure using a fluidized bed reactor is disclosed in Patent Application Publication No. 10-2009-0073346, No. 10-2009-0013503, and the like. In the case of using a fluidized bed reactor, a dispersing plate is used so that the gas is uniformly distributed in the reactor and powder such as catalyst existing on the dispersing plate does not pass below the dispersing plate.

In the upper side of the fluidized bed reactor body having such a structure, a discharge pipe is installed to recover the product. Since the reaction part and the recovery part are located in the same space, the discharge pipe may be clogged due to the caulking phenomenon caused by hydrocarbon as raw material. Also, since the flow discharged to the discharge pipe exists only on one side of the upper part of the reactor, there is a problem that the raw material particles in the reactor are biased in a specific direction.

A problem to be solved by the present invention is to provide a fluidized bed reactor capable of preventing a clogging phenomenon and securing a uniform fluidity by providing a column through the inside of the main body to separate the reaction part and the recovery part.

Another object of the present invention is to provide a method for producing a carbon nanostructure using the fluidized bed reactor.

According to an aspect of the present invention,

A reactor body;

A dispersion plate disposed inside the reactor body;

A gas supply pipe for supplying the reaction gas in an upward flow manner from the lower part of the dispersion plate to the upper part;

A catalyst supply pipe disposed at a lower portion of the reactor body to supply a catalyst; And

And an inner column disposed inside the main body and having a lower height than the main body, the inner column having a product discharge pipe for discharging the produced carbon nanostructure and the mixed gas to the outside of the main body.

According to another aspect of the present invention,

Supplying a catalyst to the fluidized bed reactor according to claim 1;

Supplying a reactant gas containing a carbon source, a reducing gas and an inert gas into the reactor;

Reacting the catalyst and the reaction gas in a reaction space inside the reactor to produce a carbon nanostructure; And

And recovering the carbon nanostructure produced,

The inner column separates the fluidized bed reactor body from the in-column area and the out-column area,

Wherein the reaction gas flows along with the catalyst supplied through the catalyst supply pipe and flows in the outer region of the column and reacts to generate a carbon nanostructure and a mixed gas.

The fluidized bed reactor according to the present invention can prevent the clogging due to the raw material and ensure the uniform fluidity by providing the column in the main body and separating the reaction part and the recovery part.

1 shows a schematic view of a reactor body with an inner column according to one embodiment.
Figure 2 shows a cross-sectional view of a fluidized bed reactor having an internal column according to one embodiment in a reactor body.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be described in more detail with reference to the embodiments of the invention shown in the accompanying drawings. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, or alternatives falling within the spirit and scope of the present invention.

In the drawings, like reference numerals are used for similar elements.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it is to be understood that other elements may be directly connected or connected, or intervening elements may be present.

The singular expressions include plural expressions unless otherwise specified.

It is to be understood that the terms "comprises", "includes", or "having", etc., as used herein are intended to mean that a feature, a numerical value, a step, an operation, an element, a component, Does not exclude the possibility that other features, numbers, steps, operations, components, parts, or combinations thereof may be present or added.

It is to be understood that the terms "comprises", "includes", or "having", etc., as used herein are intended to mean that a feature, a numerical value, a step, an operation, an element, a component, Does not exclude the possibility that other features, numbers, steps, operations, components, parts, or combinations thereof may be present or added.

FIG. 1 schematically shows the structure of a fluidized bed reactor according to one embodiment.

1, the fluidized bed reactor comprises a reactor body 10; A dispersion plate (13) disposed inside the reactor body; A gas supply pipe (12) for supplying the reaction gas in an upward flow manner from the lower part of the dispersion plate to the upper part; A catalyst supply pipe 25 disposed at a lower portion of the reactor body to supply a catalyst; And an inner column (2) disposed inside the main body and having a lower height than the main body, and a product discharge pipe for discharging the carbon nanostructure and the mixed gas to the outside of the main body.

In the fluidized bed reactor, the inner portion of the reactor body can be divided into two regions, i.e., an inner region of the column and an outer region of the column by the inner column (2). The reaction gas is supplied through a gas supply pipe 12 located at the bottom of the reactor body 10 and reacted with the catalyst supplied through the catalyst supply pipe 25 to flow in the region outside the column and react Carbon nanostructures and mixed gases. The carbon nanostructure and the mixed gas thus generated move to the inside of the column and are discharged to the outside through the product discharge pipe 24 passing through the separator plate 13. At this time, the product discharge pipe (24) may have a structure inclined downward to facilitate the discharge of the product.

Therefore, the reaction gas at a high concentration present in the outer region of the column is converted into the carbon nanostructure, so that the reaction gas exists in a low concentration in the inner region of the column. As a result, the reactive gas exists at a low concentration in the inside of the column, and the reaction gas of such a low concentration comes into contact with the inner wall of the inner column, thereby minimizing clogging due to caulking or the like.

The catalyst is supplied through a catalyst supply pipe 25 located at the outer lower end of the reactor body and promotes the reaction of the reaction gas in the region outside the column to form the carbon nanostructure. Accordingly, when the height of the carbon nanostructure increases from the inner column to the outer column, the gas moves to the bottom through the inner region of the inner column together with the mixed gas, and is discharged to the outside of the reactor body 10 through the product discharge pipe.

The clogging phenomenon can be suppressed by providing a column inside the reactor body 10 and separating and arranging the reaction part (the area outside the column) and the recovery part (the area inside the column) The problem that the particles in the reactor are biased in a specific direction does not occur, and uniform fluidity can be ensured.

The column 2 in the reactor body 10 is lower than the height of the reactor body 2 to facilitate recovery of the product and is able to pass through the diffuser plate 13 located at the bottom of the body 10 Can be connected to the product discharge pipe (24). That is, the gas supplied through the gas supply pipe (12) can not directly contact the inner column (2).

FIG. 2 shows an example of a fluidized bed reactor having the reactor body as described above.

1 and 2, the fluidized bed reactor is a reactor 1 in which carbon nanostructures are synthesized, the reactor 1 having a main body 10 having an inner space; And an inner column (2) disposed within the body (10).

The lower portion of the reactor body 10 may be formed as a tapered region 10a. A heater 19 may be provided outside the reactor body 10. A raw material gas supply unit 12 is provided at the bottom of the reactor 1. The raw material gas is supplied to the reactor main body 10 through the raw gas supply pipe 21 and can be preheated in the preheater 17 before being supplied to the reactor main body 10.

According to one embodiment, the fluidized bed reactor comprises

i) an extension (11) connected to the top of the reactor (1); ii) a separator (14) attached to the side surface of the reactor body (10) to separate the mixed gas from the carbon nanostructure discharged from the reactor body; iii) a filter (18) which partially or wholly removes one or more component gases from the mixed gas discharged from the extender (11); And iv) a transfer tube (23) for discharging the mixed gas filtered by the filter (18) to the outside; May be further provided.

According to one embodiment, the manufacturing apparatus may further include a recycling pipe (not shown) for recycling a part of the mixed gas to the reactor.

A discharge tube 24 is disposed on the side surface of the reactor body 10 to transfer the generated carbon nanostructure. The discharge tube 24 is mixed with a carbon nanostructure formed in an outer region of the inner column 2, And may be installed at the lower end of the side of the reactor to transfer the gas to the collector 15.

The carbon nanostructure and the mixed gas are transferred to the separator 14 through the discharge pipe 24, and the carbon nanostructure and the mixed gas are separated. The separated carbon nanostructure is transferred to the recoverer 15 and recovered.

The reactor (1) used in the present invention is a chemical vapor deposition reactor, for example, a fluidized bed reactor.

In order to synthesize carbon nanostructures by chemical vapor deposition (CVD), the reaction time of the reaction gas and the catalyst is required to be at least 10 minutes, and the residence time of the carbon nanostructure and catalyst to be produced in the reactor is determined by the purity And yield.

In the fluidized bed reactor, the catalyst is distributed evenly inside the catalyst and the contact between the catalyst and the reaction gas is excellent, the heat is easily diffused during the exothermic reaction and the retention time of the catalyst and the target product carbon nanostructure can be secured in the reactor, The production rate of the carbon nanostructure can be made).

The reactor is supplied with a carbon source, a reducing gas, an inert gas and the like through the reaction gas supply pipe 21 from the lower part of the reactor to the upper part of the reactor, Thereby separating the nanostructures.

The reaction gas supply pipe 21 is not particularly limited as long as it can be used in a manufacturing apparatus of a fluidized bed reactor. Specifically, it may be a gas distributor or the like.

The catalyst supply pipe 25 is not particularly limited as long as it can be used for the production of carbon nanostructures. Specifically, the catalyst supply pipe 25 may be a hopper, a feeder, a screw feeder, a rotary air lock valve A catalytic feeder composed of a rotary airlock valve, or the like.

The catalyst may be a heterogeneous catalyst composed of a composite structure of an active metal and a support, which may be conventionally used in the production of carbon nanostructure, and more specifically, a supported catalyst, a coprecipitation catalyst, and the like. When the supported catalyst is used as the preferred catalyst, the bulk density of the catalyst itself is higher than that of the coprecipitation catalyst. Unlike the coprecipitation catalyst, unlike the coprecipitation catalyst, fine particles less than 10 microns are less agglomeration And it is possible to reduce the possibility of occurrence of fine particles due to attrition which may occur in the fluidization process, and the mechanical strength of the catalyst itself is also excellent, so that the operation of the reactor can be stabilized.

When a coprecipitation catalyst is used as a preferable catalyst form, there is a merit that the production method of the catalyst is simple, the preferable metal salts are low in the cost of the catalyst raw material, and there is a virtual favorable aspect of the production, and a large specific surface area and high catalytic activity.

The inert gas may be nitrogen (N ₂ ), argon (Ar), or the like.

The operation mode of the fluidized bed reactor is formed by forming a fluidized bed in a reactor and reacting the catalyst with the reaction gas in the fluidized bed. As the reaction proceeds, the carbon or tube structure grows on the active metal of the catalyst, (collecting pipe) at the upper side of the reactor when the bulk density is lowered.

The bulk density may be 0.03 to 0.3 g / cm3, preferably 0.05 to 0.2 g / cm3.

The flow rate of the fluidized bed formed in the reactor 10 is preferably 0.03 to 100 cm / s, more preferably 0.1 to 70 cm / s.

The minimum fluidization velocity of the fluidized bed in the reactor 10 is preferably 0.03 to 15 cm / s, more preferably 0.1 to 10 cm / s.

The reactor (1) comprises a catalyst supply pipe (25) to which a catalyst is supplied; A reaction gas supply pipe 21 to which a carbon source, a reducing gas and an inert gas are supplied; And a product discharge pipe 24 through which the mixed gas containing the produced carbon nanotube and the reaction by-product gas is discharged.

Examples of the carbon source include a carbon-containing gas which can be decomposed in a heated state, and specific examples thereof include aliphatic alkanes, aliphatic alkenes, aliphatic alkynes, and aromatic compounds. More specific examples thereof include methane, ethane, ethylene, acetylene, ethanol, , Carbon monoxide, propane, butane, benzene, cyclohexane, propylene, butene, isobutene, toluene, xylene, cumene, ethylbenzene, naphthalene, phenanthrene, anthracene, acetylene, formaldehyde, acetaldehyde, CH _4), ethane (C ₂ H _6), carbon monoxide (CO), acetylene (C ₂ H _2), ethylene (C ₂ H _4), propylene (C ₃ H _6), propane (C ₃ H _8), butane (C ₄ H ₁₀ ) and a mixture of liquefied petroleum gas (LPG).

The separator 14 is not particularly limited as long as it is a means, a device, or a device capable of separating the carbon nanostructure and the mixed gas, but it may be a cyclone.

The filter 18 comprises a material, an apparatus, a machine, a means or an apparatus for selectively separating or removing the mixed gas discharged from the elongating unit.

The filter may be a gas separation unit that separately separates the unreacted carbon source, the reducing gas and the inert gas from the mixed gas discharged from the separator connected to one or more of the upper portion of the reactor, and transfers the separated unreacted carbon source, .

The gas separation unit may be of a metal membrane type that removes a certain amount of reducing gas from the mixed gas discharged from the separator connected to one or more of the reactor upper expanders and transfers the filtered mixed gas to the recycle pipe have.

The reducing gas may be hydrogen.

The gas separation unit of the metal membrane type is capable of selectively separating hydrogen at a temperature of less than 600 ° C.

The metal membrane may be selected from the group consisting of Pd, Ir, Rh, Pd-Ni alloy, Pd-Ag alloy and Pd-Cu alloy. Among them, Pd and Pd alloy are preferably used. But is not limited thereto.

One or more metal membranes may be used, and a minimum area is required to obtain the separation efficiency of the gas to be separated. If a large-area metal membrane can be produced, a desired flux can be obtained with one membrane. However, since a densified membrane can not be manufactured at a size of 100 mm * 100 mm or more, a membrane having a maximum size can be laminated to secure a surface area It is possible.

The use of at least one metal membrane unit selectively removes only hydrogen gas as a by-product in the reaction, which is advantageous in a continuous process, control of adsorption amount, and control of recycle feed composition. However, when the separation efficiency is high, such as Pd and Pd-based alloys, separation from a single membrane is possible, and pressure and feed rate can be controlled through the separation unit. The selective separation of hydrogen gas using a metal membrane is a process in which the selectivity of hydrogen to the carbon source and inert gas used in the reaction is close to infinity and the hydrogen separation flux (H ₂ mol / M ² .sec) And the like. It is not necessary to laminate a metal membrane when a membrane having a large area can be manufactured. However, there is a limit to the production of a metal membrane of high efficiency exceeding 100 mm * 100 mm with the present technology, Or by connecting them in series. The metal membrane can be used in various shapes such as a rod shape and a sheet shape.

By separating the carbon nanostructure particles and the mixed gas from the carbon nanostructure particles produced in the reactor 10 and the mixed gas using the cyclone, the carbon nanostructure particles are recovered through the discharge pipe 24 disposed on the upper side of the reactor , The mixed gas may pass through the hydrogen separation unit and then recycled, thereby reducing the amount of the raw material input to the production amount of the carbon nanostructure without installing the heat exchanger.

Preferably, the hydrogen separation unit comprises at least one metal membrane, more preferably a metal membrane of a maximum size that can be manufactured is stacked, or connected in parallel or in series to secure a desired hydrogen permeation flux. In this case, it is possible to remove only the hydrogen gas produced in the reaction by changing the membrane injection pressure, which is advantageous in controlling the composition of the recycle feed. However, if the separation efficiency is high, it is possible to separate even one membrane, and separation is achieved by controlling the pressure and feed amount in the separation unit.

The specific gas may be fed to the recycle line as needed, particularly if some of the gas (for example, some of H ₂ ) is lacking in the gas mixture that is particularly filtered.

The unreacted carbon source included in the mixed gas is preferably controlled to 2 to 30%, more preferably 5 to 25%, of the carbon source supplied to the reactor.

The fluidized bed reactor is charged with only the carbon source consumed in the reactor and the catalyst, so that it is possible to perform an ideal process operation having substantially the same reactant composition ratio and amount.

The fluidized bed reactor may be a mixed gas containing an unreacted carbon source, an inert gas, and a by-product gas, which has been incinerated or discharged using a conventional flare stack or an incinerator, with a reducing gas (hydrogen H ₂ ) can be selectively removed and recycled to obtain a carbon source conversion rate of 98% or more without further injection of an inert gas. Thus, production cost of carbon nanostructure can be drastically reduced, incineration treatment is not necessary, It is an eco-friendly process.

In addition, the fluidized bed reactor can reduce the size of the reactor with respect to the capacity with a low energy consumption apparatus, and can greatly reduce the energy cost of the fluidized bed reactor operating at 600 to 1000 ° C.

Since the fluidized bed reactor does not require a heat exchanger, which is essentially required for cooling the reaction gas when separating the mixed gas using pressure swing adsorption (PSA) or polymer separator, it is possible to reduce the capital investment cost and the size of the reaction system Compact, fluidized bed reactor. In addition, it is possible to reduce the required calorific value and size of the preheater by recirculating the high-temperature reaction gas through the recirculation pipe without cooling.

Between the reactor and the separator may include the interior of the reactor, and a filter for separating the fine particles may also be disposed in an expander above the fluidized bed reactor.

When the carbon nanostructure synthesized in the reactor is designed to be recovered to the lower part of the reactor, the filter may be installed in the reactor for removal of fine particles contained in the mixed gas discharged to the upper part, and the catalyst, carbon nanostructure, A separator such as a cyclone separating the gaseous mixture may also be disposed within the reactor.

The component gas may be a byproduct gas generated in the reactor.

Preferably, the fluidized bed reactor further comprises control means for controlling the amount of reactive gas supplied to the reactor and the amount of the component gas removed from the filter.

The control means may be a control means for controlling the amount of the reducing gas supplied to the reactor and the amount of the reducing gas passing through the filter.

The fluidized bed reactor preferably further comprises a filter, a scrubber or both, between the separator and the filter.

The filter recovers the carbon nanostructure particles remaining in the mixed gas separated by the separator, and the scrubber can remove harmful substances such as halides present in the mixed gas separated by the separator.

Preferably, the fluidized bed reactor further comprises a preheater for preheating the reactant gas prior to introduction into the reactor.

In the fluidized bed reactor, as the reactor size increases, a large amount of inert gas is required, and a reducing gas is injected in an amount equal to or greater than that of the carbon source, so that the effect of reducing the production cost remarkably increases.

The fluidized bed reactor may not include a waste incinerator such as a flare stack or an incinerator.

The molar ratio of the carbon source to the reducing gas is preferably 1: 0.5 to 1:10, more preferably 1: 0.9 to 1: 6, most preferably 1: 1 to 1: 5, The sintering of the catalyst is suppressed by controlling the rate of formation of the carbon nanostructure within the range, the formation of amorphous carbon is inhibited, and the effect of increasing the production of graphitic carbon is obtained.

In the step of producing the carbon nanostructure, at least one selected from the group consisting of water, ammonia, NO, NO _2, etc. may be further added.

The catalyst used in the creation phase of the carbon nano structure is specifically a catalytically active metal precursor, _{Co (NO 3) 2 -6H 2} O, (NH 4) 6Mo 7 O 24 -4H 2 O, Fe (NO 3) 2 - 6H ₂ O or Ni (NO ₃ ) ₂ -6H ₂ O) dissolved in distilled water and then wet-impregnating the solution with a carrier such as Al ₂ O ₃ , SiO ₂ or MgO .

In addition, the catalyst may be produced by ultrasonically treating a carrier such as a catalytically active metal precursor and Al (OH) ₃ , Mg (NO ₃ ) ₂ or colloidal silica.

The catalyst may be prepared by a sol-gel method using a chelating agent such as citric acid or tartaric acid so that the catalytically active metal precursor can be dissolved in water, Or by co-precipitation of the active metal precursor.

The filtration can be carried out using a separation method, a separation means or a separation apparatus capable of selectively separating the mixed gas.

The metal membrane type gas separation unit may selectively remove hydrogen at a temperature of less than 600 ° C, and the metal membrane may include Pd, Ir, Rh, a Pd-Ni alloy, a Pd-Ag alloy, and a Pd- , But is not limited thereto.

The fluidized bed reactor according to the present invention can be used to produce carbon nanostructures. For example, a method for preparing a carbon nanostructure according to the present invention includes: supplying a catalyst to a fluidized bed reactor as described above; Supplying a reactant gas containing a carbon source, a reducing gas and an inert gas into the reactor; Reacting the catalyst and the reaction gas in a reaction space inside the reactor to produce a carbon nanostructure; And recovering the resulting carbon nanostructure, wherein the inner column separates the fluidized bed reactor body from the in-column region and the out-of-column region, and the reactive gas, together with the catalyst supplied through the catalyst feed line, Flow and react to produce carbon nanostructure and mixed gas.

When the height of the carbon nanostructure in the outer region of the column is greater than the height of the inner column, the carbon nanostructure and the mixed gas generated in the outer region of the column move to the inner region of the column, And the reactant gas may be present at a higher concentration in the outer region of the column than in the inner region of the column.

The method for preparing the carbon nanostructure may include the step of injecting carbon sources as much as the amount consumed in the synthesis reaction of the carbon nanostructure into the filtered gas mixture.

In the carbon nanotube manufacturing method, the step of incinerating the waste can be excluded.

The carbon nanostructure described in this specification can be interpreted as referring to a nano-sized carbon structure having various shapes such as carbon nanotubes, carbon nanofibers, fullerenes, carbon nanocones, carbon nanohorns, and carbon nanorods.

1 and 2 illustrate only the apparatus necessary for explaining the present invention and other self-evident devices required for carrying out the method, such as pumps, additional valves, piping, control devices, boosting equipment for pressurization Are omitted from the drawings.

1. Reactor 2. Internal column
10. Reactor body
11. Extension portion 12. Gas supply portion
14. Separator
17. Preheater 18. Filter

Claims (18)

A reactor body;
A dispersion plate disposed inside the reactor body;
A gas supply pipe for supplying the reaction gas in an upward flow manner from the lower part of the dispersion plate to the upper part;
A catalyst supply pipe disposed at a lower portion of the reactor body to supply a catalyst; And
And an inner column disposed in the main body and having a lower height than the main body, and a product discharge pipe for discharging the produced carbon nanostructure and the mixed gas to the outside of the main body. The method according to claim 1,
Said inner column separating said fluidized bed reactor body into an in-column region and an out-of-column region. 3. The method of claim 2,
Wherein the reaction gas flows along with the catalyst supplied through the catalyst supply pipe and flows out of the column to generate a carbon nanostructure and a mixed gas. The method of claim 3,
When the height of the carbon nanostructure in the outer region of the column is greater than the height of the inner column, the carbon nanostructure and the mixed gas generated in the outer region of the column move to the inner region of the column, To the fluidized bed reactor. 3. The method of claim 2,
Wherein the reactive gas is present at a concentration higher than the in-column region in the outer region of the column. The method according to claim 1,
i) an extension connected to the top of the reactor;
ii) a separator attached to a side surface of the reactor to separate the carbon nanostructure and the mixed gas discharged from the reactor;
iii) a filter which partially or wholly removes one or more component gases from the mixed gas discharged from the extender; And
iv) a transfer tube for discharging the mixed gas filtered by the filter; ≪ / RTI > wherein the fluidized bed reactor further comprises one or more of the following. The method according to claim 6,
And iii) the filter is a gas separation unit for separating a certain amount of the reducing gas from the mixed gas discharged from the elongating unit. 8. The method of claim 7,
Lt; RTI ID = 0.0 > 1, < / RTI > wherein the reducing gas comprises hydrogen. The method according to claim 6,
Wherein the mixed gas discharged from the separator in ii) comprises a by-product gas produced in the reactor. The method according to claim 1,
Wherein the reactor is a chemical vapor deposition reactor. The method according to claim 6,
And ii) the separator comprises a cyclone. The method according to claim 6,
And iii) the filter comprises a metal membrane. 13. The method of claim 12,
Wherein the metal membrane selectively separates hydrogen at a temperature less than < RTI ID = 0.0 > 600 C. < / RTI > 13. The method of claim 12,
Wherein the metal membrane comprises at least one selected from the group consisting of Pd, Ir, Rh, a Pd-Ni alloy, a Pd-Ag alloy, and a Pd-Cu alloy. Supplying a catalyst to the fluidized bed reactor according to claim 1;
Supplying a reactant gas containing a carbon source, a reducing gas and an inert gas into the reactor;
Reacting the catalyst and the reaction gas in a reaction space inside the reactor to produce a carbon nanostructure; And
And recovering the carbon nanostructure produced,
The inner column separates the fluidized bed reactor body from the in-column area and the out-column area,
Wherein the reaction gas flows along with the catalyst supplied through the catalyst supply pipe and flows in the outer region of the column to generate a carbon nanostructure and a mixed gas. 16. The method of claim 15,
When the height of the carbon nanostructure in the outer region of the column is greater than the height of the inner column, the carbon nanostructure and the mixed gas generated in the outer region of the column move to the inner region of the column, And the carbon nanostructure is discharged to the outside. 16. The method of claim 15,
Wherein the reactive gas exists at a higher concentration in the outer region of the column than in the inner region of the column. A method for producing a carbon nanostructure, which comprises using a fluidized bed reactor according to any one of claims 1 to 14.

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