Carbon nanotube production system and carbon nanotube production method

Abstract

A carbon nanotube production system according to an embodiment of the present invention comprises: a reactor that generates a carbon nanotube fluid in a first direction; the conveying device part is separated from the reactor in the first direction, and the conveying device part comprises a mesh belt, and the mesh belt continuously runs in a second direction perpendicular to the first direction and captures a carbon nanotube structure from the carbon nanotube fluid; and a collection unit for collecting the carbon nanotube unit body from the carbon nanotube structure.

Description

Technical Field

[0001] The invention provides a carbon nanotube production system and a carbon nanotube production method. Background Art

[0002] Carbon nanotubes (CNTs) have excellent chemical stability and mechanical physical properties as well as high thermal conductivity, and therefore are materials used in many fields.

[0003] Carbon nanotubes are classified into single-walled carbon nanotubes having a structure in which a layer of graphite structure is curled and connected at the ends, double-walled carbon nanotubes having a concentric axis formed by two layers of single-walled carbon nanotubes, and multi-walled carbon nanotubes having multiple single-walled structures, etc. according to the synthesis conditions.

[0004] Methods for synthesizing carbon nanotubes include vapor deposition, arc discharge, laser ablation, and high-pressure vapor phase methods, etc. Since the synthesized carbon nanotube particles are small in size, they are usually obtained by aggregation to improve the handleability.

[0005] Aggregated carbon nanotubes need to be separated again into individual carbon nanotube particles to be used as additives, etc. In this case, the process of separating the aggregated carbon nanotubes again is complicated and takes a long time, and thus a method of obtaining carbon nanotubes without the above process is required. Summary of the invention

[0006] 1. Technical issues to be resolved

[0007] A technical problem of the present invention is to provide a carbon nanotube production system which offers increased process reliability and efficiency.

[0008] One technical problem underlying the present invention is to provide a method for producing carbon nanotubes which offers increased process reliability and efficiency.

[0009] (II) Technical solution

[0010] According to the present invention, a carbon nanotube production system is provided, which includes: a reactor, which generates a carbon nanotube fluid along a first direction; a conveying device part, which is arranged to be separated from the reactor along the first direction, and the conveying device part includes a mesh belt, which continuously runs along a second direction perpendicular to the first direction and captures carbon nanotube structures from the carbon nanotube fluid; and a collecting part, which recovers carbon nanotube units from the carbon nanotube structures.

[0011] According to an exemplary embodiment, the carbon nanotube fluid may include a single-walled carbon nanotube aerosol.

[0012] According to an exemplary embodiment, the reactor may include a floating catalyst chemical vapor deposition (FCCVD) reactor.

[0013] According to an exemplary embodiment, the carbon nanotube production system may further include: a carbon source introduction part, which is combined with the front end of the reactor; and a discharge part, which is combined with the rear end of the reactor and discharges the carbon nanotube fluid along the first direction.

[0014] According to an exemplary embodiment, the moving speed (cm / sec) of the mesh belt is proportional to the flow rate (cm / sec) of the carbon nanotube fluid discharged from the discharge portion. 3 / second) can be 0.16cm -2 Up to 0.65cm -2 .

[0015] According to an exemplary embodiment, the carbon nanotube production system may further include a gas supply part supplying a carrier gas to the carbon source introduction part.

[0016] According to an exemplary embodiment, the conveyor section may further include a roller driving the mesh belt.

[0017] According to an exemplary embodiment, the collecting part may include a brush part that collects the carbon nanotube structures in a prescribed size.

[0018] According to an exemplary embodiment, the mesh belt may include openings that allow the carbon nanotube fluid to penetrate and pass through the mesh belt.

[0019] According to an exemplary embodiment, the carbon nanotube production system may further include a housing for accommodating the mesh belt. The housing may include an exhaust portion for exhausting the carbon nanotube fluid passing through the mesh belt.

[0020] According to an exemplary embodiment, the exhaust portion may be located in a linear flow direction along the first direction of the carbon nanotube fluid.

[0021] According to an exemplary embodiment, the reactor may include a plurality of reactors spaced apart along the second direction.

[0022] According to the present invention, a method for producing carbon nanotubes is provided, which comprises the following steps: generating a carbon nanotube fluid along a first direction; supplying the carbon nanotube fluid to a mesh belt continuously running along a second direction perpendicular to the first direction to form a carbon nanotube structure; and collecting carbon nanotube units from the carbon nanotube structure.

[0023] According to an exemplary embodiment, the carbon nanotube fluid may be generated only in a single direction of the first direction.

[0024] According to an exemplary embodiment, the step of generating the carbon nanotube fluid may include generating a single-walled carbon nanotube aerosol by a floating catalyst chemical vapor deposition (FCCVD) process.

[0025] (III) Beneficial effects

[0026] The carbon nanotube production system according to the exemplary embodiment of the present invention can directly capture carbon nanotubes (eg, single-walled carbon nanotubes (SWCNT)) in a prepared shape. Therefore, non-aggregated carbon nanotubes can be quickly produced.

[0027] The carbon nanotube production system according to the exemplary embodiment of the present invention includes a mesh belt, so that carbon nanotubes in an aerosol state can be effectively collected. The fluid containing carbon nanotubes is directly passed through the mesh belt, so that the aggregation of carbon nanotubes can be prevented. Therefore, carbon nanotubes with uniform physical properties can be produced.

[0028] According to the method for producing carbon nanotubes according to the exemplary embodiment of the present invention, non-aggregated carbon nanotubes can be produced rapidly and in large quantities. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic diagram illustrating a carbon nanotube production system according to an exemplary embodiment.

[0030] Figure 2 is a schematic diagram showing a carbon nanotube production system according to a comparative example.

[0031] Figure 3 is a schematic diagram illustrating a carbon nanotube production system according to some exemplary embodiments. DETAILED DESCRIPTION

[0032] The present invention provides a carbon nanotube production system with improved production efficiency.

[0033] Furthermore, the present invention provides a method for producing carbon nanotubes with improved production efficiency.

[0034] Hereinafter, the present invention will be described in detail with reference to the accompanying drawings, but this is merely exemplary, and the present invention is not limited to the specific embodiments described exemplarily.

[0035] Figure 1 Schematic diagram showing a carbon nanotube production system according to an exemplary embodiment. Figure 1 , a carbon nanotube production system and a production method are described together.

[0036] Reference Figure 1 , the carbon nanotube production system according to the exemplary embodiment may include a preparation part 100 and a collection part 200. In the preparation part 100, the carbon source may react at a high temperature to prepare the carbon nanotubes. In the collection part 200, the carbon nanotubes prepared in the preparation part 100 may be recovered and collected.

[0037] The preparation part 100 may include a carbon source introduction part 110, a reactor 120, and a discharge part 130. The carbon source introduction part 110 may be combined with a front end portion of the reactor 120, and the discharge part 130 may be combined with a rear end portion of the reactor 120.

[0038] The reactor 120 may include a floating catalyst chemical vapor deposition (FCCVD) reactor, and in the preparation section 100, carbon nanotubes may be prepared by a floating catalyst chemical vapor deposition method (FC-CVD). The floating catalyst chemical vapor deposition method is a method for synthesizing carbon nanotubes by continuously supplying a catalyst and a carbon source as a raw material while spraying. Therefore, unlike intermittent synthesis, carbon nanotubes may be produced continuously.

[0039] A carbon source as a raw material of carbon nanotubes may be introduced from the carbon source introduction unit 110. In addition, a mixture including a carbon source and a catalyst may be introduced from the carbon source introduction unit 110.

[0040] The preparation part 100 may further include a gas supply part 115. A carrier gas may be injected into the carbon source introduction part 110 through the gas supply part 115. The carrier gas introduced from the gas supply part 115 may be sprayed to the mixture containing the carbon source and the catalyst added from the carbon source introduction part 110. Therefore, the carbon source and the catalyst may be dispersed inside the reactor 120 in an aerosol state.

[0041] The carbon source is not particularly limited, but hydrocarbons can be used as the carbon source, for example. For example, the hydrocarbons can include: chain saturated aliphatic hydrocarbons such as methane, ethane, propane, hexane, heptane, octane, nonane, decane, dodecane, tetradecane, etc.; chain unsaturated aliphatic hydrocarbons having one or more double bonds such as ethylene, acetylene, propylene, etc.; cyclic saturated aliphatic hydrocarbons such as cyclohexane; cyclic unsaturated hydrocarbons such as benzene and toluene, etc. These can be used alone or in combination of two or more.

[0042] In addition, the carbon source may also include hydrocarbon organic compounds. For example, the carbon source may include alcohols such as ethanol and propanol.

[0043] The catalyst is not particularly limited, but may include, for example, a transition metal compound or transition metal particles as a metal-based catalyst. The transition metal compound may be decomposed in the reactor 120, thereby generating transition metal particles that may directly serve as a catalyst.

[0044] The transition metal may include, for example, iron, nickel, cobalt, scandium, titanium, vanadium, chromium, manganese, etc. The transition metal compound may include an organic transition metal compound or an inorganic transition metal compound containing the transition metal. The organic transition metal compound may include, for example, ferrocene, nickelocene, cobaltocene, carbonyl iron, ferric acetylacetonate, iron oleate, etc., and the inorganic transition metal compound may include, for example, ferric chloride, etc. These may be used alone or in combination of two or more.

[0045] The carrier gas may include, for example, argon, nitrogen, hydrogen, etc. These may be used alone or in combination of two or more.

[0046] The reactor 120 may contain catalyst aerosol inside. By spraying the carrier gas, catalyst particles may be dispersed in the reactor 120 in an aerosol state, and the carbon source may be decomposed on the surface of the catalyst particles to grow carbon nanotubes.

[0047] The preparation part 100 may further include a heating device 140. The heating device 140 may be provided outside the reactor 120, and the heating device 140 may be used to apply heat energy required for a growth reaction of the carbon nanotubes to the reactor 120.

[0048] When the reactor 120 is heated by the heating device 140 and a reaction is performed, the carbon source may be decomposed at a high temperature, thereby allowing the carbon nanotubes to grow. The heating device 140 may increase the temperature of the reactor 120 to about 600°C to 1500°C.

[0049] After the reaction is completed, carbon nanotube aerosol may exist in the reactor 120. The carbon nanotube aerosol may be a state in which nano-sized carbon nanotube particles are dispersed in a gas phase medium (eg, carrier gas).

[0050] The reactor 120 may generate a carbon nanotube fluid along a first direction. The carbon nanotube fluid may include a carrier gas in which carbon nanotubes are dispersed. For example, the carbon nanotube fluid may include a single-walled carbon nanotube aerosol. Figure 1 As shown, the reactor 120 may be vertical, and the first direction may be the direction of gravity. Figure 1 Unlike the illustrated case, the reactor 120 may be of a horizontal type and the first direction may be a horizontal direction.

[0051] The carbon nanotube fluid may be discharged from the reactor 120 in the first direction through the discharge portion 130. Therefore, the carbon nanotubes in an aerosol state may be captured on the mesh belt described below, and the amount of carbon nanotubes lost by being dispersed into other spaces may be minimized.

[0052] Although not shown separately, the discharge portion 130 may include a flow rate regulating device for regulating the flow rate of the discharged carbon nanotube fluid, for example, may include a flow rate regulating device in the form of a propeller.

[0053] The carbon nanotube fluid may be generated only in a single direction of the first direction, thereby preventing the carbon nanotubes from dispersing and disappearing.

[0054] Next, the carbon nanotube fluid may be supplied to a conveyor portion (mesh belt) that continuously runs in a second direction perpendicular to the first direction to form a carbon nanotube structure.

[0055] The collection part 200 may include a conveyor part 210 and a collecting part 220. The conveyor part 210 may include a mesh belt 212 and a roller 215, and the roller 215 may drive the mesh belt 212. The mesh belt 212 may be spaced apart from the discharge part 130 in a first direction, and may continuously run in a second direction perpendicular to the first direction.

[0056] like Figure 1 As shown, the reactor 120 may be vertical, the first direction may be the gravity direction, and the second direction may be the horizontal direction. Figure 1 Different from the situation shown, the reactor 120 may be a horizontal type, the first direction may be a horizontal direction, and the second direction may be a gravity direction.

[0057] The carbon nanotube structure may be captured on the surface of the mesh belt 212. The carbon nanotube fluid discharged from the discharge portion 130, for example, the discharge flow A containing the single-walled carbon nanotube aerosol may pass through the mesh belt 212, so that the carbon nanotube structure may remain on the surface of the mesh belt 212, and the air flow A' containing the particulate catalyst etc. may pass through the mesh belt and be discharged. The carbon nanotube structure may include a plurality of single carbon nanotubes, and each carbon nanotube may be in a state of being aggregated by van der Waals force.

[0058] The mesh belt 212 may be driven by the roller 215 without a separate support, and the mesh belt 212 may include an opening through which the carbon nanotube fluid may penetrate and pass. Therefore, the discharge flow A may be discharged through a first portion of the mesh belt 212 adjacent to the reactor 120 and a second portion of the mesh belt 212 spaced apart from the first portion in a first direction. Since the discharge flow may be discharged while continuously operating, the carbon nanotubes contained in the carbon nanotube structure captured on the surface of the mesh belt 212 may be in a state without excessive aggregation.

[0059] The mesh belt 212 may have a suitable line width and spacing to capture only carbon nanotubes from the exhaust stream. The line width of the mesh belt 212 may be about 1 μm to 3 μm, and the spacing may be about 4 μm to 20 μm.

[0060] Within the above range, the carbon nanotubes can be efficiently captured while the airflow A' can smoothly pass through the mesh belt, and the carbon nanotubes can be continuously produced.

[0061] The moving speed (cm / sec) of the mesh belt 212 and the flow rate (cm / sec) of the carbon nanotube fluid discharged from the discharge unit 130 are related to each other. 3 / second) can be 0.16cm -2 Up to 0.65cm -2 In some embodiments, the moving speed (cm / sec) of the mesh belt 212 is proportional to the flow rate (cm / sec) of the carbon nanotube fluid discharged from the discharge portion 130. 3 / second) can be 0.23cm -2 Up to 0.42cm -2 or 0.3cm -2 Up to 0.35cm -2 Within the above range, the loss of carbon nanotubes can be reduced while the production speed can be increased, thereby improving the production efficiency of carbon nanotubes.

[0062] Next, the carbon nanotube unit bodies may be collected from the carbon nanotube structure.

[0063] The carbon nanotube structures captured on the surface of the continuously running mesh belt 212 may be collected in the collecting part 220. The collecting part 220 may include a collecting container 222 to collect the carbon nanotubes, and the collecting part 220 may include a brush part 225 to recover the carbon nanotubes from the surface of the mesh belt 212.

[0064] The mesh belt 212 may move in the second direction, and the collecting part 220 may be disposed in the second direction apart from the mesh belt 212. Therefore, the carbon nanotube structures on the surface of the mesh belt 212 may move in the second direction and be collected in the collecting part 220.

[0065] The carbon nanotube structure can be recovered from the surface of the mesh belt 212 by the brush part 225. The brush part 225 can contact the surface of the mesh belt 212 and rotate continuously, so that the carbon nanotube structure can be collected in a prescribed size and collected in the collection container 222. For example, the carbon nanotube structure can be separated by the brush part 225, so that the carbon nanotube unit body as a single carbon nanotube particle can be collected in the collection container 222.

[0066] Although not shown separately, the brush portion 225 may also be disposed between the mesh belt 212 and the collection container 222, and may also contact the surface of the mesh belt 212 in a fixed state and scrape the carbon nanotubes, so that the carbon nanotube units may be recovered into the collection container 222. At the portion where the brush portion 225 contacts the mesh belt 212, the brush portion 225 may rotate in a direction opposite to the moving direction of the mesh belt 212. Therefore, the brush portion 225 may act as a scraper to scrape off the carbon nanotubes on the surface of the mesh belt 212, and the carbon nanotube units may be collected into the collection container 222.

[0067] The conveyor section 210 may include at least one roller 215 driving the mesh belt 212. The number of rollers 215 may be increased or decreased in consideration of the length, density, and running speed of the mesh belt 212. The carbon nanotube units collected into the collection container 222 as described above may minimize aggregation, thereby being maintained in an optimal state for subsequent processing.

[0068] The carbon nanotube unit body may include single-walled carbon nanotubes (SWCNTs), multi-walled carbon nanotubes (MWCNTs), thin-walled carbon nanotubes (TWCNTs), etc. For example, it may include SWCNTs.

[0069] The carbon nanotube production system may include a collection unit 200 inside a housing 300 containing a mesh belt 212. When the carbon nanotube fluid is discharged from the discharge unit 130, the housing 300 may separate the exterior from the interior so that the carbon nanotube particles are not lost to the air.

[0070] The housing 300 may include an exhaust portion V, which exhausts the carbon nanotube fluid passing through the mesh belt 212, for example, exhausts the airflow A' containing residual catalysts, etc. For example, the exhaust portion V may be located in the straight flow direction along the first direction of the carbon nanotube fluid. Therefore, the carbon nanotube fluid can pass through the mesh belt and be discharged (A') in the shortest path, and the vortex generated by the airflow inside the housing 300 can be minimized. Therefore, it is possible to prevent very light single carbon nanotubes from being lost or dispersed due to the airflow inside the housing 300.

[0071] Figure 2 is a schematic diagram showing a carbon nanotube production system according to a comparative example.

[0072] Reference Figure 2 The carbon nanotube production system according to the comparative example produces carbon nanotube fibers by aggregating and winding the carbon nanotubes contained in the discharge flow A discharged from the reactor 120 into a fiber form F. In this case, the carbon nanotubes aggregated in the gravity direction are wound on the surface of the winding device W in the fiber form F and obtained, and the carbon nanotube fibers are in a form that is excessively aggregated in the diameter direction and the length direction of the carbon nanotubes.

[0073] The carbon nanotube fiber produced by the carbon nanotube production system according to the comparative example requires reprocessing or post-treatment to obtain individual carbon nanotubes, and thus may be disadvantageous in terms of process economics.

[0074] In the carbon nanotube production system according to the present invention, in order to reduce the aggregation of carbon nanotubes, the carbon nanotube structure can be directly captured on the surface of the mesh belt in the carbon nanotube fluid state. Therefore, the carbon nanotube unit body can be simply obtained without a separate subsequent process, thereby improving the production efficiency of carbon nanotubes.

[0075] The carbon nanotube production system according to the exemplary embodiment may include one or more preparation parts 100. For example, the carbon nanotube production system may include 1 to 10 preparation parts 100. Therefore, a large amount of carbon nanotubes may be continuously produced.

[0076] Figure 3 Schematic diagram showing a carbon nanotube production system according to an exemplary embodiment. Figure 1 The structures and configurations described are substantially the same as or similar to the detailed descriptions of the structures and configurations.

[0077] Reference Figure 3 , the carbon nanotube production system may include a plurality of preparation sections (100a, 100b, 100c, 100d). Figure 3 4 shows a case where four preparation units 100 are included, but as described above, the number of preparation units 100 may vary. Figure 3 In the figure, the housing 300 is omitted for ease of illustration.

[0078] Each preparation section ( 100 a , 100 b , 100 c , 100 d ) may include its own reactor.

[0079] In an exemplary embodiment, the plurality of preparation parts may include a first preparation part to an nth preparation part, and n may be an integer from 2 to 10. The first preparation part to the nth preparation part may be sequentially spaced apart and arranged along the second direction.

[0080] Continue to refer to Figure 3 The plurality of preparation sections may be a first preparation section 100a, a second preparation section 100b, a third preparation section 100c and a fourth preparation section 100d which are sequentially arranged along the second direction.

[0081] In an exemplary embodiment, the flow rate of the carbon nanotube fluid discharged from the m+1th production section may be greater than the flow rate of the carbon nanotube fluid discharged from the mth production section. m is an integer of 1 to 9, and is a number smaller than n.

[0082] Among the multiple preparation sections, the closer the preparation section is to the collection section, the greater the flow rate of the discharged carbon nanotube fluid can be. The greater the flow rate, the greater the amount of carbon nanotube structures captured on the surface of the mesh belt 212.

[0083] In the second direction, when the aerosol discharge flow rate of the first preparation part 100a that first discharges carbon nanotubes onto the mesh belt 212 is the smallest, the amount of carbon nanotube structures captured on the surface of the mesh belt 212 is relatively small, thereby reducing mesh clogging. Therefore, the carbon nanotubes contained in the discharge flows (A2, A3, A4) of the subsequent second to fourth preparation parts (100b, 100c, 100d) can be efficiently captured, and the airflows (A2', A3', A4') after the carbon nanotubes are captured can pass smoothly through the mesh belt 212.

[0084] In an exemplary embodiment, Figure 3 Different from the situation shown, the flow rates of the discharged aerosols of the multiple preparation sections may also be the same.

[0085] Generally, the carbon nanotubes prepared by the FC-CVD method are obtained by aggregating into a fiber form and winding it outside the exhaust port. The carbon nanotube fiber is a state in which many short carbon nanotubes are aggregated in the length direction and the diameter direction. In order to use the carbon nanotube fiber in various fields, it is necessary to go through a process of separating the carbon nanotube fiber into single strands of carbon nanotubes and / or short carbon nanotubes.

[0086] The carbon nanotube unit bodies produced from the carbon nanotube production system can be captured in a gas phase dispersion state, for example, in an aerosol state, immediately after production in the preparation section, and thus a carbon nanotube structure with minimized aggregation can be obtained.

[0087] Therefore, short-length carbon nanotubes can be used after being obtained without going through a separate process, and the productivity of the carbon nanotubes can be improved.

[0088] The above-described contents are merely examples of applying the principles of the present invention, and other configurations may be included without departing from the scope of the present invention.

Claims

1. A carbon nanotube production system, comprising: a reactor, wherein the reactor generates a carbon nanotube fluid along a first direction; a conveyor unit, the conveyor unit being spaced apart from the reactor along the first direction, and the conveyor unit comprising a mesh belt, the mesh belt continuously running along a second direction perpendicular to the first direction and capturing carbon nanotube structures from the carbon nanotube fluid; as well as A collecting unit is provided for collecting carbon nanotube unit bodies from the carbon nanotube structure.

2. The carbon nanotube production system according to claim 1, wherein: The carbon nanotube fluid includes single-walled carbon nanotube aerosol.

3. The carbon nanotube production system according to claim 1, wherein: The reactor comprises a floating catalyst chemical vapor deposition (FCCVD) reactor.

4. The carbon nanotube production system according to claim 1, wherein: The carbon nanotube production system further includes: a carbon source introduction part, which is combined with the front end of the reactor; and a discharge part, which is combined with the rear end of the reactor and discharges the carbon nanotube fluid along the first direction.

5. The carbon nanotube production system according to claim 4, wherein: The ratio of the moving speed of the mesh belt to the flow rate of the carbon nanotube fluid discharged from the discharge portion is 0.16 cm -2 Up to 0.65cm -2 , wherein the unit of the moving speed of the mesh belt is cm / s, and the unit of the flow rate of the carbon nanotube fluid discharged from the discharge part is cm 3 / Second.

6. The carbon nanotube production system according to claim 4, wherein: The carbon nanotube production system further includes a gas supply part that supplies a carrier gas to the carbon source introduction part.

7. The carbon nanotube production system according to claim 1, wherein: The conveyor section further includes a roller that drives the mesh belt.

8. The carbon nanotube production system according to claim 1, wherein: The collecting unit includes a brush unit for collecting the carbon nanotube structures in a predetermined size.

9. The carbon nanotube production system according to claim 1, wherein: The mesh belt includes openings that allow the carbon nanotube fluid to penetrate and pass through the mesh belt.

10. The carbon nanotube production system according to claim 9, wherein: The carbon nanotube production system further includes a housing for accommodating the mesh belt, the housing including an exhaust portion for exhausting the carbon nanotube fluid passing through the mesh belt.

11. The carbon nanotube production system according to claim 10, wherein: The exhaust portion is located in a linear flow direction along the first direction of the carbon nanotube fluid.

12. The carbon nanotube production system according to claim 1, wherein: The reactor includes a plurality of reactors spaced apart along the second direction.

13. A method for producing carbon nanotubes, comprising the following steps: generating a carbon nanotube fluid along a first direction; supplying the carbon nanotube fluid to a mesh belt that continuously runs in a second direction perpendicular to the first direction to form a carbon nanotube structure; as well as The carbon nanotube unit bodies are collected from the carbon nanotube structure.

14. The method for producing carbon nanotubes according to claim 13, wherein: The carbon nanotube fluid is generated only along a single direction of the first direction.

15. The method for producing carbon nanotubes according to claim 13, wherein: The step of generating the carbon nanotube fluid includes generating a single-walled carbon nanotube aerosol by a floating catalyst chemical vapor deposition (FCCVD) process.

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