KR20140129643A - Fluidized bed reactor and process for manufacturing carbon nanostructures using same - Google Patents

Abstract

According to the present invention, there is provided a reactor comprising: a reactor body; A dispersion plate mounted inside the reactor body; And a protruding structure formed on an inner wall of the reactor main body above the dispersion plate, and a method for manufacturing a carbon nanostructure using the fluidized bed reactor.

Description

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

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 that can be used for producing carbon nanostructures such as carbon nanotubes.

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 formed by bonding three neighboring carbon atoms 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-described manufacturing methods, carbon nanostructures are produced by dispersing and reacting metal catalyst particles and hydrocarbon-based raw material gases in a fluidized bed reactor at a high temperature. 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. The dispersion plate is generally formed using a perforated plate, a bubble cap, a sieve, or a nozzle.

However, since the upper part of the dispersion plate of the fluidized bed reactor does not have enough flow in the radial direction, the powder and the gas are not mixed well, and powder is accumulated on the edge of the dispersion plate. If the contact between the reaction gas and the catalyst is not uniform, growth to the carbon nanostructure is not smooth and the residence time is prolonged. Also, due to the phenomenon of unreacted catalyst being deposited on the dispersion plate or clogging of the dispersion plate Uniform injection of the reaction gas is obstructed and pressure drop occurs, which makes it difficult to operate the fluidized bed in a stable manner.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the problems described above, and it is an object of the present invention to provide a fluidized bed reactor capable of inducing smooth and uniform contact between a reaction gas and a catalyst by improving the phenomenon of accumulation of powder on the edge of a dispersion plate of a fluidized bed reactor, ≪ / RTI >

In order to achieve the above object, according to the present invention, there is provided a reactor comprising: a reactor body;

A dispersion plate mounted inside the reactor body; And

And a protruding structure formed on the inner wall of the reactor body above the dispersion plate.

According to a preferred embodiment of the present invention, the protruding structure may be an annular structure.

According to an embodiment of the present invention, the protruding structure may be a structure whose longitudinal section is triangular, trapezoidal, hemispherical, or semi-elliptic.

According to a preferred embodiment of the present invention, the fluidized bed reactor comprises a catalyst supply pipe for supplying the catalyst into the reactor main body, and a reactive gas which is connected to the lower portion of the reactor and contains a carbon source, a reducing gas and an inert gas, And a reaction gas supply pipe for supplying the catalyst and the reaction gas to the interior of the reactor via a plate, wherein the catalyst and the reaction gas react with each other while flowing in the reaction space inside the reactor body to produce a carbon nanostructure.

The present invention also relates to a process for the preparation of a catalyst, comprising: feeding a catalyst through a catalyst feed line of a fluidized bed reactor as described above;

Supplying a reactive gas including a carbon source, a reducing gas, and an inert gas through a reactive gas supply pipe to supply the reactive gas into the reactor through the dispersing plate; And

And reacting the catalyst and the reaction gas in a reaction space inside the reactor while reacting to produce a carbon nanostructure.

The fluidized bed reactor according to the present invention can prevent the particle accumulation at the edge of the dispersion plate by guiding the particles flowing downward from the protruding structure formed on the inner wall of the reactor body to the center of the reactor. In addition, since the protruding structure of the inner wall of the reactor serves to reduce the diameter of the reaction tube at the corresponding position, stable fluidized bed operation is possible because it increases the gas upward flow at the position of the protruding structure and promotes the upward flow of the particles. Therefore, when a carbon nanostructure is manufactured using the fluidized bed reactor according to the present invention, a high quality product can be obtained with high yield.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic block diagram of an example of a fluidized bed reactor for producing carbon nanotubes. FIG.
2 is a cross-sectional view and a longitudinal sectional view schematically showing the structure of a fluidized bed reactor according to an embodiment of the present invention.
3 is a perspective view schematically showing the internal structure of the fluidized bed reactor shown in FIG.
4 and 5 are a cross-sectional view and a perspective view schematically showing another embodiment of the present invention.
6 and 7 are a cross-sectional view and a perspective view schematically showing still another embodiment of the present invention.

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.

The terms first, second, A, B, etc. may be used to describe various components, but the components are not limited by these terms, and may be used to distinguish one component from another Only.

The term " and / or " includes any one or a combination of the plurality of listed items.

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 will be understood that the terms "comprises", "having", and the like have the same meanings as the features, numbers, steps, operations, elements, parts or combinations thereof described in the specification, Does not exclude the possibility that an operation, component, component, or combination thereof may be present or added.

1 schematically shows the structure of a fluidized bed reactor, which fluidized bed reactor can be used, for example, in the production of carbon nanotubes, but is not limited to the manufacture of carbon nanotubes. Such fluidized bed reactors are useful for the production of carbon nanostructures such as, for example, carbon nanotubes or carbon nanofibers.

Referring to the drawings, a fluidized bed reactor 1 has a reactor body 10, and a lower portion of the reactor body 10 is formed as a tapered region 10a. In order to heat the reactor body 10 to a high temperature, it is preferable that a heater 19 is provided outside the reactor body 10.

A raw material gas supply unit 12 is provided at the bottom of the fluidized bed reactor 1. The raw material gas may be, for example, a hydrocarbon-based gas for producing carbon nanotubes. The raw material gas is supplied to the inside of the reactor main body 10 through a raw material gas supply pipe 21 connected to the raw material gas supply unit 12. The feed gas may be preheated in the preheater 17 before being fed into the reactor body 10. The raw material gas is dispersed into the reaction space in the reactor main body 10 through the dispersing plate 13 by disposing the dispersing plate 13 below the reaction space formed inside the reactor main body 10.

FIG. 1 shows a case where the dispersion plate 13 is provided at the upper end of the tapered region. However, the present invention is not limited thereto, and a dispersion plate may be provided by arbitrarily selecting the lower end of the tapered region in accordance with the purpose of the gas and solid. have.

On the upper portion of the reactor body 10, a stretching portion 11 is provided. The expander 11 may be provided with a separator (not shown) for preventing the catalyst and the reaction product (for example, carbon nanotube) from being discharged to the outside, for example, from the reactor body 10 . A filter 18 is connected to the elongated portion 11 and the component gas filtered by the filter 18 is conveyed through the conveying pipe 23. On the other hand, a recirculation pipe 22 is connected to the expansion part 11 to recirculate part of the mixed gas discharged from the expansion part 11 to the raw material gas supply pipe 21 through the recirculation pipe 22.

A separator 14 is connected to one side of the upper portion of the reactor main body 10 through a pipe 24. The separator 14 is for separating the product from the mixed gas discharged from the reactor body 10, for example, for separating the mixed gas from the carbon nanotube. A separator 14 is connected to one side of the reactor body 10 through a pipe 15 to collect a product such as carbon nanotubes. On the other hand, the catalyst supplier 16 is connected to the pipe 26 so that the catalyst can be supplied to the inside of the reactor main body 10 through the pipe 26. Although not shown in the drawing, the pipe 26 is provided with a blower so that the mixed gas separated from the separator 14 and the catalyst supplied from the catalyst feeder 16 can be fed into the reactor main body 10.

The dispersion plate 13 provided in the fluidized bed reactor as described above uniformly disperses the raw material gas into the fluidized bed reactor body 10 and the powder produced by the catalyst particles or the reaction drops to the bottom of the fluidized bed reactor . In the gas-solid fluidized bed reactor, when solid particles such as catalyst are placed on the dispersion plate and the reaction gas is blown from below through the holes formed in the dispersion plate 13, the catalyst is dispersed in the dispersion plate 13 of the fluidized bed reactor body 10, The reaction occurs while flowing in the upper space.

2 and 3 are a cross-sectional view and a perspective view schematically showing a fluidized bed reactor according to an embodiment of the present invention.

As shown, the fluidized bed reactor according to the present invention comprises a reactor body 10; A dispersion plate (13) mounted inside the reactor body; And a protruding structure (30) formed on the inner wall of the reactor body above the dispersion plate (13).

2 and 3, according to a preferred embodiment of the present invention, the protruding structure 30 may be an annular structure 30 provided along the inner wall of the cylindrical reactor body. This annular protruding structure 30 reduces the diameter of the reactor body at the position and helps to form a flow path in the center of the reactor (see the cross-sectional view in FIG. 2).

2, the protruding structure 30 has a longitudinal section shown as a triangle, but is not limited thereto, and may have a trapezoidal shape, a hemispherical shape, or a semi-elliptical shape.

Figs. 4 and 5 show a case where the projecting structure 30 has a semi-longitudinal shape in accordance with another embodiment of the present invention.

6 and 7 show a case in which the projecting structure 30 has a semicircular or semi-elliptical profile in accordance with another embodiment of the present invention.

The longitudinal shape of the protruding structure 30 is not limited as long as the particulate reactive material falling down toward the reactor wall can be moved to the center of the reactor without accumulating on the protruding structure 30. [

The dispersion plate 13 used in the fluidized bed reactor according to the present invention is not particularly limited as long as it is capable of gas communication and is selected from a metal foam, a perforated plate, a nozzle, a sieve, .

The dispersion plate may have a uniform opening ratio over the entire area, but it may include regions having different opening ratios if necessary. For example, in order to make the flow velocity of the gas injected into the reactor body uniform, it is also possible to configure the region where the gas inflow rate is relatively high, for example, the center region of the dispersing plate to have a lower opening ratio than the surrounding region.

According to a preferred embodiment of the present invention, the fluidized bed reactor comprises a catalyst supply pipe for supplying the catalyst into the reactor main body, and a reactive gas which is connected to the lower portion of the reactor and contains a carbon source, a reducing gas and an inert gas, And a reaction gas supply pipe for supplying the catalyst and the reaction gas to the interior of the reactor via a plate, wherein the catalyst and the reaction gas react with each other while flowing in the reaction space inside the reactor body to produce a carbon nanostructure.

The present invention also relates to a process for the preparation of a catalyst, comprising: feeding a catalyst through a catalyst feed line of a fluidized bed reactor as described above;

Supplying a reactive gas including a carbon source, a reducing gas, and an inert gas through a reactive gas supply pipe to supply the reactive gas into the reactor through the dispersing plate; And

And reacting the catalyst and the reaction gas in a reaction space inside the reactor while reacting to produce a carbon nanostructure.

The fluidized bed reactor according to the present invention can prevent the particle accumulation at the edge of the dispersion plate by guiding the particles flowing downward from the protruding structure formed on the inner wall of the reactor body to the center of the reactor. In addition, since the protruding structure of the inner wall of the reactor serves to reduce the diameter of the reaction tube at the corresponding position, stable fluidized bed operation is possible because it increases the gas upward flow at the position of the protruding structure and promotes the upward flow of the particles. Therefore, when a carbon nanostructure is manufactured using the fluidized bed reactor according to the present invention, a high quality product can be obtained with high yield.

10. Reactor body
11. Extension
12. Feed gas
13. Dispersion plate
21. Raw gas supply pipe
30. Protruding structure

Claims (5)

A reactor body;
A dispersion plate mounted inside the reactor body; And
And a protruding structure formed on an inner wall of the reactor body above the dispersion plate.
The fluidized bed reactor according to claim 1, wherein the protruding structure is an annular structure.
The fluidized bed reactor according to claim 1, wherein the projecting structure is a structure whose longitudinal section is triangular, trapezoidal, hemispherical, or semi-elliptical.
4. The process according to any one of claims 1 to 3, wherein the fluidized bed reactor
A catalyst supply pipe for supplying the catalyst into the reactor main body,
And a reaction gas supply pipe connected to the lower portion of the reactor to supply a reaction gas containing a carbon source, a reducing gas and an inert gas to the inside of the reactor through the dispersion plate,
Wherein the catalyst and the reactant gas react with each other while flowing in a reaction space inside the reactor body to produce a carbon nanostructure.
Feeding a catalyst through a catalyst feed pipe of the fluidized bed reactor of claim 4;
Supplying a reactive gas including a carbon source, a reducing gas, and an inert gas through a reactive gas supply pipe to supply the reactive gas into the reactor through the dispersing plate; And
And reacting the catalyst and the reaction gas in a reaction space inside the reactor while reacting to produce a carbon nanostructure.
A method for producing a carbon nanostructure.

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