JP2006001798A - Manufacturing method of carbon particle containing nano-carbon, carbon particle manufactured through the same and engine used in the manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a non-conventional manufacturing method for efficient and continuous mass production of nano-carbon-containing carbon particles such as carbon nanotube, the nano-carbon-containing carbon particles manufactured through the same, and an engine used in the manufacturing method. <P>SOLUTION: A pulverizer 1 is connected to a hopper 2 which is connected to an air inlet passage 9 of the engine 3 via piping 12. An exhaust passage 10 of the engine 3 has a primary collector 4 that collects the carbon particles produced in the engine 3. The lower surface of the primary collector 4 communicates with a centrifugal separator 6, and a dryer 7 and a carbon particle collector 8 are successively located downstream of the centrifugal separator 6. A vapor-phase part 4b of the primary collector 4 communicates with a secondary collector 5 whose open end is covered with a hood 19 that communicates with a fine carbon particle collector 16 via piping 20. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing carbon particles containing nanocarbon such as carbon nanotubes, carbon particles produced by the production method, and an engine used in the production method.

As a method for producing the carbon nanotube, an arc discharge method or a laser evaporation method is known. The arc discharge method is a method in which an arc discharge is performed on a graphite electrode embedded with a catalyst in an inert gas, and carbon nanotubes are deposited on the tip of the electrode. On the other hand, the laser evaporation method is a method for producing carbon nanotubes by irradiating a graphite electrode embedded with a catalyst with a pulsed laser in an inert gas and instantaneously evaporating carbon and catalytic metal.
In addition, a chemical vapor deposition method is known. In this manufacturing method, for example, a hydrocarbon-based raw material such as benzene or ethylene is supplied to a heating furnace with a carrier gas such as argon together with a nickel-based or cobalt-based catalyst. In this method, carbon nanotubes are produced by the action of a catalyst while the carbon-based raw material passes through a heating furnace.
Patent Documents 1 to 4 disclose mass production methods of carbon nanotubes based on these production methods.

JP 2003-160319 A JP 2003-206115 A JP 2003-81617 A JP 2003-238127 A

However, the carbon nanotube production method based on the arc discharge method or the laser evaporation method has a problem that productivity is low and it is not suitable for mass production.
On the other hand, a method for producing carbon nanotubes based on chemical vapor deposition has attracted attention as one method for mass production techniques, but has a problem in safety due to the harmfulness of raw materials. In addition, it may be necessary to vaporize the raw material during the reaction, and the entire manufacturing process is complicated.

  The present invention has been made to solve such problems. A method for continuously and efficiently producing a large amount of carbon particles containing nanocarbon such as carbon nanotubes, and the like. An object of the present invention is to provide carbon particles containing nanocarbon produced by the method, and an engine used in the production method.

A method for producing carbon particles containing nanocarbon according to the present invention includes a step of pulverizing a carbon-based raw material to a particle size of 0.3 to 500 microns to obtain a fine-particulate carbon-based raw material, Continuously supplied with air from the intake port to the combustion chamber of the engine having the intake and exhaust ports, carbon particles containing nanocarbon are generated by compression and explosion of the engine, and carbon particles are discharged together with the exhaust gas of the engine from the exhaust port. And a step of recovering carbon particles from the exhaust gas.
The particulate carbon-based raw material may be continuously supplied from the intake port to the combustion chamber of the engine accompanied with the gas. The entrained gas is preferably air, an inert carrier gas or a hydrocarbon gas.
By such a production method, carbon particles containing nanocarbon are produced.
An engine is used in the manufacturing apparatus according to the present invention.

  According to the present invention, fine carbon obtained by finely pulverizing a carbon-based raw material is continuously supplied to the engine, and carbon particles containing nanocarbon are produced by the explosion of the engine cycle. Carbon particles can be produced.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
Embodiment 1 FIG.
As shown in FIG. 1, a pulverizer 1 for pulverizing a carbon-based raw material is connected to a hopper 2. The hopper 2 has a vibrator 11 for vibrating the hopper 2, and is connected to an intake passage 9 of the engine 3 through a pipe 12. As the engine 3, any engine that has a cylinder and an air supply / exhaust mechanism and causes continuous explosion in the cylinder can be used, and examples thereof include a rotary engine, a reciprocating engine, and a diesel engine.

A muffler 13 is provided in the exhaust passage 10 of the engine 3, and a primary collector 4 for collecting carbon particles generated in the engine 3 is provided downstream thereof. The primary collector 4 includes a tank 4a that stores water therein. A collision plate 14 extending downward is provided at the center of the upper lid of the tank 4a so as not to contact the water surface.
A pipe 15 is provided on the lower surface of the primary collector 4 and communicates with the centrifuge 6. A dryer 7 is provided downstream of the centrifugal separator 6, and a carbon particle recovery device 8 is further provided downstream thereof.

On the other hand, the gas phase part 4b of the primary collector 4 communicates with the secondary collector 5 provided downstream.
As shown in FIG. 2, the secondary collector 5 includes a main body 30 having an open top, an air discharge pipe 31 that stands upright at four corners of the main body 30, and a fan 18 that communicates with the air discharge pipe 31. ing. An air discharge port 21 facing upward as shown in FIG. 1 is provided on the surface of the air discharge pipe 31. The air sent from the fan 18 is discharged from the air discharge port 21 through the inside of the air discharge pipe 31.
When the secondary collector 5 is viewed from above, air is released from the air discharge pipe 31 in the direction of the arrow 32 shown in FIG. 3. Therefore, in the secondary collector 5, the air is vertically upward. A swirling flow as indicated by arrow 33 is formed.

  A hood 19 is provided above the secondary collector 5 so as to cover the open surface, and communicates with the fine carbon particle collector 16 via a pipe 20. A cloth 17 is stretched on the upper surface of the fine carbon particle collector 16. The cloth 17 is a very fine mesh cloth that does not allow fine carbon particles to pass but allows air to pass.

Next, the operation of the manufacturing apparatus according to the first embodiment will be described.
The carbon-based raw material is charged into the fine pulverizer 1. Here, the carbon-based raw material is a substance containing carbon such as graphite, carbon black, or fly ash. The particle size of the carbon-based raw material to be charged is preferably 1 to 800 μm, and more preferably 10 to 500 μm so as not to reduce the pulverization efficiency in the fine pulverizer 1.
This carbon-based raw material is pulverized in the fine pulverizer 1 to fine-particle carbon having a particle size of 0.3 to 500 μm, preferably 0.5 to 200 μm.
The particulate carbon is discharged from the pulverizer 1 and stored in the hopper 2. The hopper 2 is vibrated by the vibrator 11, and the particulate carbon in the hopper 2 is smoothly dropped onto the pipe 12.

On the other hand, when the engine 3 is operated, an air-fuel mixture in which fuel is mixed with air is taken into the engine 3 from the intake passage 9. Due to the suction pressure when the engine 3 sucks the air-fuel mixture, the particulate carbon in the pipe 12 is sucked into the engine 3 together with the air-fuel mixture. The amount of particulate carbon supplied to the engine 3 depends on the rotational speed of the engine 3. For example, in the case of an engine with a displacement of 2000 cc, the supply amount when the engine rotational speed is 2000 rpm is 10 to 20 g / sec. When the engine speed is 4000 rpm, the supply amount is 30 to 40 g / sec. Preferred conditions in this embodiment are an engine speed of 3000 rpm and a supply rate of 25 g / sec.
The particulate carbon sucked into the engine 3 in this manner is converted into nanocarbon by an instantaneous combustion explosion (instantaneous explosion) in the Otto cycle. In the present application, nanocarbon refers to carbon particles having a particle size of 1000 nm or less, and carbon nanotubes and the like are included therein.

The carbon particles containing nanocarbon discharged from the engine 3 by the exhaust process of the Otto cycle are discharged into the exhaust passage 10 together with the exhaust gas, and enter the primary collector 4 through the muffler 13.
In the primary collector 4, the carbon particles containing nanocarbon collide with the collision plate 14 along with the exhaust gas. Here, the carbon particles having a relatively large particle size are released from the exhaust gas, fall, and are collected in the stored water.
On the other hand, the carbon particles having a small particle diameter continue to be accompanied by the exhaust gas as they are, pass through the gap between the water surface and the collision plate 14, and are discharged from the primary collector 4.

The carbon particles having a small particle size including nanocarbon are discharged from the primary collector 4 and then entrained by the exhaust gas and enter the secondary collector 5.
In the secondary collector 5, the air sent from the fan 18 is discharged from the air discharge port 21 to form a swirling flow 33 in the vertical upward direction as shown in FIG. As a result, carbon particles having a small particle size rise.
The small-sized carbon particles entrained in the swirling flow 33 are collected in the hood 19 and enter the fine carbon particle recovery device 16 through the pipe 20. At this time, the air is exhausted from the gap 22 between the secondary collector 5 and the hood 19, and further exhausted through the cloth 17 in the fine carbon particle recovery device 16, whereby carbon particles having a small particle size are obtained. Is recovered by the fine carbon particle recovery unit 16.

  In this way, the carbon particles containing nanocarbon are collected in either the water in the primary collector 4 or the fine carbon particle collector 16. The water in the primary collector 4 that has collected the carbon particles is periodically sent to the centrifuge 6 via the pipe 15. After separating water with the centrifugal separator 6, the moisture remaining in the dryer 7 is removed, and carbon particles containing nanocarbon are accommodated in the carbon particle recovery container 8.

  As described above, since the carbon raw material is continuously charged into the engine 3 and the nanocarbon is synthesized by the instantaneous explosion in the engine 3, the nanocarbon can be continuously produced in large quantities.

  In the first embodiment, the pulverizer 1 and the hopper 2 are connected for automation, but the present invention is not limited to such a form. You may make it convey the fine particle carbon obtained with the fine crusher installed in another place, and throw it into the hopper 2. FIG.

Embodiment 2. FIG.
Next, the manufacturing method of the carbon particle containing the nanocarbon concerning this Embodiment 2 is demonstrated based on FIG. In the following embodiments, the same reference numerals as those in FIG. 1 are the same or similar components, and detailed description thereof will be omitted.
The manufacturing method according to Embodiment 2 of the present invention is obtained by changing the configuration of the primary collector 4 with respect to Embodiment 1.
The primary collector 40 of the manufacturing apparatus according to this embodiment includes a cooler 41 and a carbon particle separator 42.
Cooling water is stored in the cooler 41, and the exhaust passage 10 passes through the cooling water.
The carbon particle separator 42 is provided with the collision plates 43 alternately from the upper and lower surfaces inside. A vinyl sheet 44 is laid on the lower surface to collect the carbon particles.

Similarly to the first embodiment, carbon particles containing nanocarbon are discharged from the engine 3 together with the exhaust gas. The carbon particles pass through the exhaust passage 10 and are cooled by the cooler 41 while being accompanied by the exhaust gas. After that, it is sent to the carbon particle separation device 42 and passes through the zigzag path in the vertical direction formed by the collision plate 43 while colliding with the collision plate 43. At this time, when colliding with the collision plate 43, carbon particles having a relatively large particle size are released from the exhaust gas and fall onto the vinyl sheet 44. On the other hand, the carbon particles having a small particle diameter continue to be entrained in the exhaust gas and are sent to the secondary collector 5.
The carbon particles having a small particle diameter are collected in the fine carbon particle collecting device 16 in the same manner as in the first embodiment. On the other hand, carbon particles having a large particle diameter are collected by opening the carbon particle separation device 42 after the engine 3 is stopped and collecting the carbon particles accumulated on the vinyl sheet 44.

  Thus, without using water in the primary collector, the collision plate formed a zigzag path in the vertical direction, and relatively large particles were collected by passing through the path. There is no need to dry the collected carbon particles, and the collection process can be simplified.

Embodiment 3 FIG.
The manufacturing method according to Embodiment 3 of the present invention is such that particulate carbon is supplied from the hopper 2 to the engine 3 along with the gas, compared to Embodiment 1.
In the manufacturing apparatus according to this embodiment, as shown in FIG. 5, a gas cylinder 50 filled with gas supplied to the engine 3 in the pipe 12 is connected to the pipe 12 via a hose 51. Yes. Other components are the same as those of the manufacturing apparatus according to the first embodiment.

When supplying the particulate carbon from the hopper 2 to the engine 3, the air in the gas cylinder 50 is supplied into the pipe 12 through the hose 51, and the particulate carbon is supplied to the engine 3 along with the air. Thereafter, carbon particles containing nanocarbon are produced by the same method as in the first embodiment.
As described above, the particulate carbon in the hopper 2 is supplied to the engine 3 along with the air, so that the particulate carbon is smoothly fed into the engine 3 by the suction pressure of the engine 3 and the pumping by the air. Will be supplied to.

  In this embodiment, air is used as the gas. However, the gas is not limited to air, and a carrier gas such as argon or a hydrocarbon gas such as ethylene can be used. Further, each of these gases is not used alone, but a plurality of gases can be mixed and used.

  Since the carbon particles obtained by the manufacturing method according to the first to third embodiments of the present invention contain nanocarbons such as carbon nanotubes, for example, as electronic materials, energy materials, composite materials, nanotechnology materials, Can be used in a wide range of fields.

The present invention will be specifically described with reference to the following examples.
In this example, nanocarbon was manufactured by the method described in the first embodiment. The carbon-based raw material was finely pulverized with a fine pulverizer 1 to obtain fine carbon particles having an average particle diameter of about 110 μm in the hopper 2. This particulate carbon raw material was supplied to the engine 3 operating at a rotational speed of 3000 rpm with a feed rate of 25 g per second. Carbon particles containing nanocarbon are produced by the instantaneous explosion in the engine 3, and the carbon containing nanocarbon is supplied to the carbon particle collection container 8 and the fine carbon particle collection device 16 through the primary collector 4 and the secondary collector 5. Particles were collected. The production amount was 3 g per second.

  The particle size distribution of the carbon particles containing nanocarbon thus produced is shown in FIG. As shown in FIG. 6, it was confirmed that 5.08% by weight of nanocarbon having a particle size of 1000 nm (1 μm) or less was contained.

It is a block diagram of the apparatus for manufacturing the carbon particle containing nanocarbon which concerns on Embodiment 1 of this invention. It is a block diagram of the secondary collector 5 which concerns on Embodiment 1. FIG. It is a top view of the secondary collector 5 which concerns on Embodiment 1. FIG. It is a block diagram of the apparatus for manufacturing the carbon particle containing nanocarbon which concerns on Embodiment 2. FIG. FIG. 6 is a configuration diagram of an apparatus for producing carbon particles containing nanocarbon according to a third embodiment. It is a particle size distribution of the carbon particle obtained in the Example.

Explanation of symbols

  1 fine pulverizer, 2 hoppers, 3 engines, 4,40 primary collector, 5 secondary collector, 9 intake passage, 10 exhaust passage, 50 gas cylinder.

Claims (7)

Pulverizing the carbon-based raw material to a particle size of 0.3 to 500 microns to obtain a particulate carbon-based raw material;
The particulate carbon-based raw material is continuously supplied to the combustion chamber of the engine having an intake port and an exhaust port together with air from the intake port to generate carbon particles containing nanocarbon by compression and explosion of the engine, and the exhaust Discharging the carbon particles together with the exhaust gas of the engine from the mouth;
The manufacturing method of the carbon particle containing nanocarbon provided with the process of collect | recovering the said carbon particle from the said exhaust gas.   2. The method for producing carbon particles containing nanocarbon according to claim 1, wherein the particulate carbon-based raw material is continuously supplied from a gas inlet to a combustion chamber of the engine along with a gas.   The method for producing carbon particles containing nanocarbon according to claim 2, wherein the gas is air.   The method for producing carbon particles containing nanocarbon according to claim 2, wherein the gas is an inert carrier gas.   The method for producing carbon particles containing nanocarbon according to claim 2, wherein the gas is a hydrocarbon gas.   The carbon particle manufactured by the manufacturing method of the carbon particle containing the nanocarbon as described in any one of Claims 1-5.   The engine used for the manufacturing method of the carbon particle containing the nanocarbon as described in any one of Claims 1-5.

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