KR101876293B1 - Continuous process for mass production of multi walled carbon nanotube and the catalyst for preparing the carbon nanotube - Google Patents

Continuous process for mass production of multi walled carbon nanotube and the catalyst for preparing the carbon nanotube Download PDF

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KR101876293B1
KR101876293B1 KR1020160134182A KR20160134182A KR101876293B1 KR 101876293 B1 KR101876293 B1 KR 101876293B1 KR 1020160134182 A KR1020160134182 A KR 1020160134182A KR 20160134182 A KR20160134182 A KR 20160134182A KR 101876293 B1 KR101876293 B1 KR 101876293B1
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catalyst
carbon nanotubes
gas
carbon
carbon nanotube
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KR20180041878A (en
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류상효
성현경
정충헌
김동환
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금호석유화학 주식회사
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Priority to PCT/KR2016/013114 priority patent/WO2018074652A1/en
Priority to CN201611050828.3A priority patent/CN107954413A/en
Priority to JP2016228866A priority patent/JP6357215B2/en
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    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/15—Nano-sized carbon materials
    • C01B32/158—Carbon nanotubes
    • C01B32/16—Preparation
    • C01B32/162—Preparation characterised by catalysts
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/76—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/84—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36 with arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
    • B01J23/85—Chromium, molybdenum or tungsten
    • B01J23/88—Molybdenum
    • B01J23/881—Molybdenum and iron
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J23/00—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00
    • B01J23/70—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper
    • B01J23/76—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36
    • B01J23/84—Catalysts comprising metals or metal oxides or hydroxides, not provided for in group B01J21/00 of the iron group metals or copper combined with metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36 with arsenic, antimony, bismuth, vanadium, niobium, tantalum, polonium, chromium, molybdenum, tungsten, manganese, technetium or rhenium
    • B01J23/85—Chromium, molybdenum or tungsten
    • B01J23/88—Molybdenum
    • B01J23/882—Molybdenum and cobalt
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/0009—Use of binding agents; Moulding; Pressing; Powdering; Granulating; Addition of materials ameliorating the mechanical properties of the product catalyst
    • B01J37/0027—Powdering
    • B01J37/0045—Drying a slurry, e.g. spray drying
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/08—Heat treatment
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J37/00—Processes, in general, for preparing catalysts; Processes, in general, for activation of catalysts
    • B01J37/08—Heat treatment
    • B01J37/082—Decomposition and pyrolysis
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B32/00—Carbon; Compounds thereof
    • C01B32/15—Nano-sized carbon materials
    • C01B32/158—Carbon nanotubes
    • C01B32/16—Preparation
    • C01B32/164—Preparation involving continuous processes
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K7/00—Use of ingredients characterised by shape
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B2202/00—Structure or properties of carbon nanotubes
    • C01B2202/06—Multi-walled nanotubes

Abstract

The present invention relates to a continuous production process for mass production of carbon nanotubes and a catalyst for producing carbon nanotubes. More particularly, the present invention relates to a catalyst for mass production of multi-walled carbon nanotubes, a continuous manufacturing process of carbon nanotubes, and a catalyst for manufacturing carbon nanotubes.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous process for mass production of multi-walled carbon nanotubes and a catalyst for manufacturing carbon nanotubes,

The present invention relates to a continuous production process for mass production of carbon nanotubes and a catalyst for producing carbon nanotubes. More particularly, the present invention relates to a catalyst for mass production of multi-walled carbon nanotubes, a continuous process for manufacturing carbon nanotubes, and a catalyst for manufacturing carbon nanotubes.

First discovered by Dr. Ijima in 1991, carbon nanotubes are substances in which one carbon is combined with another carbon atom into a hexagonal honeycomb pattern to form a tube, and the diameter of the tube is extremely small to several nanometers. Carbon nanotubes are known as promising new materials in the future due to their excellent mechanical properties, electrical and selectivity, excellent field emission characteristics and high efficiency hydrogen storage media characteristics. Therefore, it is known that carbon nanotubes can be applied to a wide range of technical fields such as aerospace, biotechnology, environmental energy, materials industry, medicine medical, electronic computer, security security and the like.

In order to produce carbon nanotubes on a large scale, researches on the production of suitable catalysts and the production process of carbon nanotubes for synthesizing carbon nanotubes in large quantities are actively underway.

In order to produce such carbon nanotubes on a large scale, it is possible to design the catalyst manufacturing process and the carbon nanotube manufacturing process as separate single processes or one continuous manufacturing process, There may arise a problem that the catalyst activity of the catalyst composition for manufacturing carbon nanotubes produced in the process is degraded due to storage stability.

That is, in the case of the catalyst composition for preparing carbon nanotubes, the catalyst composition at a high temperature as well as physical shape changes such as aggregation and collapse between various metal elements of the catalyst over time, It was difficult to synthesize carbon nanotubes with high purity and high yield.

Therefore, it is more preferable to carry out the reaction by connecting the catalyst manufacturing process for manufacturing carbon nanotubes and the carbon nanotube manufacturing process to one continuous manufacturing process.

As catalyst metals for producing carbon nanotubes, metals such as iron (Fe), cobalt (Co), and nickel (Ni) are known. In addition to the above metals, metals such as Cr, Mn, Mo, V, T, Sn, Pd, Is known to have catalytic activity for preparation. Recently, a supported catalyst in which a catalyst is supported on an inert carrier has been developed in order to further enhance the activity of the catalyst.

Korean Patent Registration No. 10-1007183 A supported catalyst for synthesizing carbon nanotubes, a method for producing the same, and a carbon nanotube using the same, is characterized in that at least one metal catalyst selected from Fe, Co or Ni is supported on alumina, magnesium oxide, Catalysts have been disclosed.

On the other hand, the patent document discloses molybdenum (Mo) as an activating agent for promoting catalytic activity of Fe, Co or Ni catalyst metal. In this case, the role of molybdenum in the catalyst composition is as follows. When the catalyst powder obtained by spray drying in the catalyst production process is calcined at a high temperature of 500 to 600 ° C. for about 0.5 hour, the catalytic metal of Fe, Co or Ni and the support (Al, Mg, Si) It is added as a heat stabilizer to prevent agglomeration and collapse. Therefore, molybdenum was an optional component added selectively as needed in the catalyst composition for producing carbon nanotubes.

The present inventors have already developed a number of catalyst compositions as catalyst compositions for the preparation of multi-walled carbon nanotubes.

Korean Patent Registration No. 10-976174 'Catalyst Composition for the Preparation of Thin Multiwalled Carbon Nanotubes and Method for Producing the Same' discloses a catalyst composition for preparing carbon nanotubes having a composition of [Fe a : Al b ] x : M y : Mg z There is one. M, Co, Ni, Cr, Mn, Mo, W, V, Mo, and the like are used as an inert support, and Mg is an oxide or a derivative thereof. Sn or Cu, or an oxide or derivative thereof.

Also disclosed is a catalyst composition for preparing carbon nanotubes composed of a composition of [Co a : Al b ] x : M y : Mg z in Korean Patent Registration No. 10-1018660 'Catalyst composition for the production of multiwalled carbon nanotubes'. Wherein M represents Ni, Cr, Mn, Mo, W, Pb, Ti, or a combination thereof; and Co and Al represent catalytic active materials such as cobalt, aluminum, Sn or Cu, or an oxide or derivative thereof.

Also disclosed is a catalyst composition for preparing carbon nanotubes composed of a composition of [Fe a : Mo b ] x : M y : Al z in Korean Patent Registration No. 10-1303061 'Catalyst composition for manufacturing multi-walled carbon nanotubes'. M, Co, Ni, Ti, Mn, W, Sn, or Cu as an inactive support, and Fe, Mo as a catalytically active substance, , Or an oxide or derivative thereof.

Accordingly, the inventors have already found that the composition of the catalyst composition for preparing multi-walled carbon nanotubes includes Fe and Al as essential constituents in the Korean Patent Registration No. 10-976174, and Korean Patent Registration No. 10-1018660 discloses Co , Al as essential constituents, and Korean Patent No. 10-1303061 contains Fe and Mo as essential constituents.

Therefore, the catalyst composition disclosed in the patent includes Fe, Co, Mo and Al as essential constituents. Therefore, the optimal constituents of the catalyst composition for preparing multi-walled carbon nanotubes are the main catalyst (Fe, Co) Is predicted as a catalyst composition composed of a catalyst (Mo) and a support (Al).

Accordingly, the present inventors prepared a catalyst for the production of carbon nanotubes of various compositions on the basis of the catalyst composition (Fe, Co, Mo, Al) predicted in a scale-up large-scale process by spray pyrolysis, Tubes were continuously synthesized in a fluidized bed reactor and the production yield, purity and bulk density of the multi-walled carbon nanotubes were measured to confirm the optimal content ratios of Fe, Co, Mo, and Al mole fractions to complete the present invention .

The present invention aims to provide a catalyst for the production of carbon nanotubes having various compositions based on catalyst composition (Fe, Co, Mo, Al) in a scale-up large-scale process by spray pyrolysis, And to develop a method for continuously synthesizing nanotubes in a fluidized bed reactor. Also, the optimum content ratio of the optimal catalyst composition (Fe, Co, Mo, Al) for producing multi-walled carbon nanotubes is measured.

The object of the present invention is achieved by a method for producing carbon nanotubes, comprising the steps of: 1) dissolving catalyst metal precursors (Fe, Co, Mo) and support precursor (Al) for preparing carbon nanotubes in water and then obtaining catalyst powder for producing carbon nanotubes by spray pyrolysis; 2) supplying fluidized catalyst powder to the fluidized bed reactor and spraying the raw material gas, and thermally depositing carbon on the catalyst particles at 600 to 900 ° C; And 3) recovering and selecting the thermally deposited carbon nanotubes to obtain multi-walled carbon nanotubes. In the continuous manufacturing process of multi-walled carbon nanotubes, the catalyst for preparing carbon nanotubes comprises a main catalyst (Fe, Co) , A promoter (Mo) and a support (Al), and the catalyst has a carbon nanotube synthesis yield of 1,400 to 3,000%.

At this time, the synthesis yield of the catalyst is obtained by the formula [synthesis yield of catalyst (%) = synthesis amount of carbon nanotubes / amount of catalyst input X 100].

The step 1) comprises: i) dissolving the catalyst metal precursor (Fe, Co, Mo) for preparing carbon nanotubes and the support precursor (Al) for preparing carbon nanotubes in water to prepare a catalyst solution, Supplying a gas and introducing outside air to atomize the catalyst solution from the nozzle; Ii) pyrolyzing the catalyst solution sprayed into the reactor at 600 to 1,200 ° C at high temperature; And iii) obtaining a catalyst powder for synthesizing carbon nanotubes. The obtained catalyst powder has an apparent density of 0.03 to 0.4 g / ml.

The catalytic metal precursor and the precursor of the catalyst precursor may be at least one selected from the group consisting of metal nitrate, sulfate, alkoxide, chloride and carbonate.

The spray gas pressure is 2.5 to 4.0 atm and the pyrolysis temperature is 600 to 1,000 ° C.

Said step 2) comprises the steps of: i) preheating the reaction chamber; Ii) supplying catalyst powder from the bottom of the reaction chamber and fluidizing the catalyst powder in the reaction chamber; Iii) injecting and supplying a source gas composed of a reaction gas and a carrier gas from the bottom of the reaction chamber; Iv) thermally depositing carbon on the catalyst particles fluidized in an upward flow through the rotation of the rotor in a reaction chamber at 600 to 900 ° C; V) exhausting the exhaust gas; And vi) selectively recovering multi-walled carbon nanotubes.

Further, the reaction gas is at least one carbon source gas selected from saturated or unsaturated hydrocarbons having 1 to 4 carbon atoms, carbon monoxide or benzene, and the carrier gas is an inert gas such as helium, nitrogen or argon.

On the other hand, the catalyst for the production of carbon nanotubes is characterized by the following formula.

Fe p , Co q , Mo r , Al s

In the above formula

p, q, r and s represent the mole fractions of Fe, Co, Mo and Al

p + q + r + s = 10

0.3? P? 3.0, 0.1? Q? 3.5, 0.05? R? 1.0 and 2.0? S? 8.5.

The catalyst for preparing the carbon nanotubes has the following mole fractions.

Fe p , Co q , Mo r , Al s

In the above formula

p, q, r and s represent the mole fractions of Fe, Co, Mo and Al

p + q + r + s = 10

0.5? P? 2.5, 0.2? Q? 3.0, 0.1? R? 0.8 and 2.5? S? 7.5.

Another object of the present invention is to provide a multi-walled carbon nanotube having a size of 5 to 15 nm, a bundle diameter of 0.5 to 4 탆, and an apparent density of 0.02 to 0.1 g / cc prepared according to the above method.

It is still another object of the present invention to provide a carbon nanotube resin composite in which electrical conductivity, thermal conductivity, antistatic property, electromagnetic wave shielding and tensile strength are increased by nanocomposite of a multiwall carbon nanotube and an engineering plastic polymer resin.

The effect of the present invention is that a catalyst for preparing carbon nanotubes of various compositions based on the catalyst composition (Fe, Co, Mo, Al) in a scale-up large-scale process is prepared by spray pyrolysis and the multiwall carbon nanotubes (Fe, Co, Mo, Al) for producing a multi-walled carbon nanotube in high yield, high purity and high apparent density by continuously synthesizing in a fluidized bed reactor.

1 shows one embodiment of an apparatus for producing a catalyst composition for producing carbon nanotubes by spray pyrolysis of the present invention.
2 shows one embodiment of an apparatus for producing carbon nanotubes by the thermal vapor deposition method of the present invention.
Fig. 3 shows one embodiment of a process for producing a catalyst composition for producing carbon nanotubes by spray pyrolysis of the present invention.
4 shows one embodiment of a process for producing carbon nanotubes by the thermal vapor deposition method of the present invention.

The present invention relates to a method for preparing carbon nanotubes, comprising the steps of: 1) dissolving catalyst metal precursors (Fe, Co, Mo) and support precursor (Al) for preparing carbon nanotubes in water, and obtaining catalyst powder for producing carbon nanotubes by spray pyrolysis; 2) supplying fluidized catalyst powder to the fluidized bed reactor and spraying the raw material gas, and thermally depositing carbon on the catalyst particles at 600 to 900 ° C; And 3) recovering and selecting the thermally deposited carbon nanotubes to obtain multi-walled carbon nanotubes. In the continuous manufacturing process of multi-walled carbon nanotubes, the catalyst for preparing carbon nanotubes comprises a main catalyst (Fe, Co) , A co-catalyst (Mo) and a support (Al), and the catalyst has a carbon nanotube synthesis yield of 1,400 to 3,000%.

The catalyst for producing carbon nanotubes used in the present invention is represented by the following formula.

Fe p , Co q , Mo r , Al s

In the above formula

p, q, r and s represent the mole fractions of Fe, Co, Mo and Al

p + q + r + s = 10

0.3? P? 3.0, 0.1? Q? 3.5, 0.05? R? 1.0 and 2.0? S? 8.5.

In the meantime, the present invention relates to a multi-walled carbon nanotube and a multi-walled carbon nanotube having a diameter of 5 to 15 nm, a bundle diameter of 0.5 to 4 탆 and an apparent density of 0.02 to 0.1 g / cc, And to provide a carbon nanotube resin composite material having increased electrical conductivity, thermal conductivity, antistatic property, electromagnetic shielding and tensile strength.

Hereinafter, the present invention will be described in more detail.

The catalyst composition for preparing carbon nanotubes used in the present invention is prepared by spray pyrolysis having the following process.

(Step 1) A catalyst solution is prepared by dissolving a catalyst metal precursor (Fe, Co, Mo) for producing carbon nanotubes and a support precursor (Al) for preparing carbon nanotubes in water, and air of 2 to 5 atm is supplied as a spray gas And introducing outside air to spray the catalyst solution from the nozzle.

The catalyst metal precursor and the support precursor are preferably in the form of at least one selected from the group consisting of metal nitrate, sulfate, alkoxide, chloride and carbonate.

1, a catalytic metal precursor (Fe, Co, Mo) for preparing carbon nanotubes and a support precursor (Al) for preparing carbon nanotubes are dissolved in water to prepare a catalyst solution, The catalyst solution is supplied into the catalyst supply part 140 at a rate of 2 to 5 atm which is the atomization gas in the gas supply part 150 and is sprayed into the reactor 110 in the form of particles in the nozzle 130. At this time, outside air is introduced into the reactor through the outside air dispenser 170.

The pressure of the air as the atomizing gas is preferably 2.5 to 4.0 atm.

(Step 2) This is pyrolysis of the catalyst solution sprayed into the reactor at 600 to 1,200 ° C at high temperature. At this time, the high-temperature pyrolysis temperature of the catalyst solution is preferably 600 to 1,000 ° C.

(Step 3) is a step of obtaining a catalyst powder for synthesizing carbon nanotubes. The apparent density of the finally obtained catalyst powder is 0.03 to 0.4 g / ml. When the apparent density of the catalyst powder is 0.03 g / ml or less, the catalyst content is too low and the yield of the catalyst synthesis of the carbon nanotubes is low. Also, even when the apparent density of the catalyst powder is 0.4 g / ml or more, the catalyst powder may not be properly dispersed and may be agglomerated, and the yield of the catalyst synthesis of the carbon nanotube is also lowered.

Therefore, when the apparent density of the catalyst powder for synthesizing carbon nanotubes is in the range of 0.03 to 0.4 g / ml, the catalyst synthesis yield of the carbon nanotubes is in the range of 1,400 to 3,000%.

In the fluidized bed reactor of the present invention, the multi-wall carbon nanotubes are thermally vapor-deposited by the following process.

(Step 1) Preheating the reaction chamber to 600 占 폚. The reaction chamber 210 is a reaction space for synthesizing carbon nanotubes, and is made of quartz or graphite, which is a high heat resistant material.

(Step 2) Supplying the catalyst powder from the bottom of the reaction chamber and fluidizing it in the reaction chamber. The catalyst powder is supplied from the catalyst supply part 220 and dispersed into the reaction chamber through the dispersion hole.

(Step 3) The raw material gas composed of the reaction gas and the carrier gas is injected from the lower part of the reaction chamber. A carrier gas, such as helium, nitrogen, or argon, which is an inert gas, is injected and supplied from the raw material gas supply unit 230 into the chamber, from a reaction gas which is one or more kinds of carbon source gases selected from saturated or unsaturated hydrocarbons, carbon monoxide or benzene having 1 to 4 carbon atoms .

(Step 4) In the step of vapor-depositing carbon on the catalyst particles fluidized by the upward flow through the rotation of the rotor in the reaction chamber of 600 to 900 ° C. Carbon supplied from at least one carbon source gas selected from saturated or unsaturated hydrocarbons, carbon monoxide or benzene having 1 to 4 carbon atoms on the catalyst particles is subjected to thermal vapor deposition.

(Step 5), and exhausting the exhaust gas. The raw material gas or a part of the catalyst remaining after the carbon is thermally deposited on the catalyst particles in the reaction chamber is discharged to the outside through the exhaust gas discharging portion 260 located above the reaction chamber.

(Step 6) Step of obtaining multi-walled carbon nanotubes selectively. The multi-walled carbon nanotubes produced according to the method of the present invention have a diameter of 5 to 15 nm, a bundle diameter of 0.5 to 4 μm and an apparent density of 0.02 to 0.1 g / cc.

Hereinafter, the catalyst composition for preparing multi-walled carbon nanotubes used in the present invention will be described in more detail.

As catalyst metals for producing carbon nanotubes, metals such as iron (Fe), cobalt (Co), and nickel (Ni) are known.

In addition to the above metals, metals such as Cr, Mn, Mo, V, T, Sn, Pd, Is known to have catalytic activity for preparation.

Further, there is disclosed a supported catalyst in which a catalyst is supported on an inert carrier (Al, Mg, Si) in order to further enhance the activity of the catalyst.

The inventors of the present invention have already recognized that Mo is the most useful catalyst for promoting the compatibility and catalytic activity between Al and the main catalyst, which are supported as the catalyst, in addition to the catalytic activity through the prior art Korean Patent Registration No. 10-1303061.

The present inventors have already found that Al is an inactive support and that it is the most useful support for promoting the catalytic activity of the main catalyst and Mo through Korean Patent Registration No. 10-976174 and Korean Patent Registration No. 10-1018660 I knew.

Therefore, the inventors of the present invention have confirmed that any catalyst metal such as Fe, Co, and Ni already known as the main catalyst exhibits the highest catalytic activity synergistic effect when mixed with the co-catalyst Mo and the support Al. That is, the catalyst composition of the present invention was tested through a spray pyrolysis catalyst production process and a continuous synthesis process of carbon nanotubes in a fluidized bed reactor, and the catalyst composition having the highest multi-wall carbon nanotube catalyst synthesis yield was confirmed.

The catalyst composition for producing carbon nanotubes developed by the present invention is represented by the following formula.

Fe p , Co q , Mo r , Al s

In the above formula

p, q, r and s represent the mole fractions of Fe, Co, Mo and Al

p + q + r + s = 10

0.3? P? 3.0, 0.1? Q? 3.5, 0.05? R? 1.0 and 2.0? S? 8.5.

The catalyst for preparing the carbon nanotubes has the following mole fractions.

Fe p , Co q , Mo r , Al s

In the above formula

p, q, r and s represent the mole fractions of Fe, Co, Mo and Al

p + q + r + s = 10

0.5? P? 2.5, 0.2? Q? 3.0, 0.1? R? 0.8 and 2.5? S? 7.5.

The multi-walled carbon nanotubes produced by the present invention have excellent mechanical properties, electrical and selectivity, excellent field emission characteristics, and high-efficiency hydrogen storage media characteristics.

Also, the carbon nanotube resin composite material obtained by nano-complexing the multi-walled carbon nanotube and the engineering plastic polymer resin of the present invention exhibits high electrical conductivity, thermal conductivity, antistatic property, electromagnetic shielding and tensile strength.

Also, the multi-walled carbon nanotubes produced according to the method of the present invention have a diameter of 5-15 nm, a bundle diameter of 0.5-4 μm and an apparent density of 0.02-0.1 g / cc.

Further, the multi-walled carbon nanotube of the present invention can be applied to a wide range of technical fields such as aerospace, biotechnology, environmental energy, material industry, medical medicine, electronic computer, security security and the like.

Hereinafter, the present invention will be described in more detail through Production Examples, Production Comparative Examples, and Examples.

(Production Example 1) Production of a catalyst composition for synthesizing carbon nanotubes of the present invention

Catalyst 1 (Fe / Co / Mo / Al = 2.0 / 2.0 / 0.5 / 5.5)

2.0 mol of Fe (NO 3 ) 3 .9H 2 O, 2.0 mol of Co (NO 3 ) 2 .6H 2 O, 0.5 mol of (NH 4 ) 6 Mo 7 O 24 .4H 2 O and 5.5 Mol of Al (NO 3 ) 3 .9H 2 O was added and stirred at room temperature for 2 hours to prepare a catalyst mixture solution in which all metal salts were completely dissolved. Then, the prepared catalyst mixture solution was pyrolyzed by spraying 0.3 L / hour of air into the reactor of the spray pyrolysis apparatus using air as a carrier gas. The spray pyrolysis conditions were as follows: the air pressure was 3 atm, the reactor internal temperature was 750 ° C, and the operation was continued for 120 minutes to collect a total of 57 g of the catalyst composition. The molar ratio of the metal used in the preparation of the catalyst was Fe / Co / Mo / Al = 2.0 / 2.0 / 0.5 / 5.5 and the apparent density of the prepared catalyst composition was 0.28 g / mL.

(Production Example 2) Production of a catalyst composition for synthesizing carbon nanotubes of the present invention

Catalyst 2 (Fe / Co / Mo / Al = 2.0 / 2.0 / 0.5 / 5.5)

2.0 mol of Fe (NO 3 ) 3 .9H 2 O, 2.0 mol of Co (NO 3 ) 2 .6H 2 O, 0.5 mol of (NH 4 ) 6 Mo 7 O 24 .4H 2 O and 5.5 Mol of Al (NO 3 ) 3 .9H 2 O was added and stirred at room temperature for 2 hours to prepare a catalyst mixture solution in which all metal salts were completely dissolved. Then, the prepared catalyst mixture solution was pyrolyzed by spraying 0.3 L / hour of air into the reactor of the spray pyrolysis apparatus using air as a carrier gas. The spray pyrolysis conditions were as follows: the pressure of air was 3 atm, the temperature inside the reactor was 850 ° C, and the catalyst composition was continuously operated for 120 minutes to collect a total of 53 g of the catalyst composition. The molar ratio of the metal used in the preparation of the catalyst was Fe / Co / Mo / Al = 2.0 / 2.0 / 0.5 / 5.5, and the apparent density of the prepared catalyst composition was 0.25 g / mL.

(Production Comparative Example 1) Production of a catalyst composition for synthesizing carbon nanotubes (difference in molar ratio)

The catalyst C-1 (Fe / Co / Mo / Al = 0.1 / 3.9 / 0.5 / 5.5)

0.1 mol of Fe (NO 3 ) 3 .9H 2 O, 3.9 mol of Co (NO 3 ) 2 .6H 2 O, 0.5 mol of (NH 4 ) 6 Mo 7 O 24 .4H 2 O and 5.5 Mol of Al (NO 3 ) 3 .9H 2 O was added and stirred at room temperature for 2 hours to prepare a catalyst mixture solution in which all metal salts were completely dissolved. Then, the prepared catalyst mixture solution was pyrolyzed by spraying 0.3 L / hour of air into the reactor of the spray pyrolysis apparatus using air as a carrier gas. The spray pyrolysis conditions were as follows: the pressure of air was 3 atm, the temperature inside the reactor was 750 ° C, and the catalyst composition was continuously operated for 120 minutes to collect a total of 52 g of the catalyst composition. The molar ratio of the metal used in the preparation of the catalyst was Fe / Co / Mo / Al = 0.1 / 3.9 / 0.5 / 5.5 and the apparent density of the prepared catalyst composition was 0.38 g / mL.

(Production Comparative Example 2) Production of a catalyst composition for synthesizing carbon nanotubes (thermal decomposition temperature difference)

Catalyst C-2 (Fe / Co / Mo / Al = 2.0 / 2.0 / 0.5 / 5.5)

2.0 mol of Fe (NO 3 ) 3 .9H 2 O, 2.0 mol of Co (NO 3 ) 2 .6H 2 O, 0.5 mol of (NH 4 ) 6 Mo 7 O 24 .4H 2 O and 5.5 Mol of Al (NO 3 ) 3 .9H 2 O was added and stirred at room temperature for 2 hours to prepare a catalyst mixture solution in which all metal salts were completely dissolved. Then, the prepared catalyst mixture solution was pyrolyzed by spraying 0.3 L / hour of air into the reactor of the spray pyrolysis apparatus using air as a carrier gas. The spray pyrolysis conditions were as follows: the pressure of air was 3 atm, the temperature inside the reactor was 400 ° C, and the operation was continued for 120 minutes to collect a total of 66 g of the catalyst composition. The molar ratio of the metal used in the preparation of the catalyst was Fe / Co / Mo / Al = 2.0 / 2.0 / 0.5 / 5.5, and the apparent density of the prepared catalyst composition was 0.41 g / mL.

(Preparation Comparative Example 3) Production of a catalyst composition for synthesizing carbon nanotubes (coprecipitation method)

Catalyst C-3 (Fe / Co / Mo / Al = 2.0 / 2.0 / 0.5 / 5.5)

2.0 mol of Fe (NO 3 ) 3 .9H 2 O, 2.0 mol of Co (NO 3 ) 2 .6H 2 O, 0.5 mol of (NH 4 ) 6 Mo 7 O 24 .4H 2 O and 5.5 mol of Al (NO 3 ) 3 .9H 2 O was added thereto and stirred at room temperature for 2 hours to prepare solution A in which all metal salts were completely dissolved. To 1 L of deionized water, 4 moles of NH 4 .HCO 3 was added and stirred for 2 hours to prepare a fully dissolved solution B. The two solutions A and B were combined at room temperature and stirred for 60 minutes. The resulting solids were then filtered and washed with deionized water to recover. The recovered filter cake was dried in air at 120 캜 for 12 hours. The dried filter cake was pulverized and then calcined in air at 600 ° C for 4 hours. The fired powder was further pulverized to obtain 81 g of a catalyst composition. The molar ratio of the metal used in the preparation of the catalyst was Fe / Co / Mo / Al = 2.0 / 2.0 / 0.5 / 5.5 and the apparent density of the prepared catalyst composition was 0.78 g / mL.

(Preparation Comparative Example 4) Preparation of catalyst composition for synthesizing carbon nanotubes (spray drying method)

Catalyst C-4 (Fe / Co / Mo / Al = 2.0 / 2.0 / 0.5 / 5.5)

2.0 mol of Fe (NO 3 ) 3 .9H 2 O, 2.0 mol of Co (NO 3 ) 2 .6H 2 O, 0.5 mol of (NH 4 ) 6 Mo 7 O 24 .4H 2 O and 5.5 mol of Al (NO 3 ) 3 .9H 2 O was added thereto and stirred at room temperature for 2 hours to prepare solution A in which all metal salts were completely dissolved. To 1 L of deionized water, 4 moles of NH 4 .HCO 3 was added and stirred for 2 hours to prepare a fully dissolved solution B. The two solutions A and B were combined at room temperature and stirred for 60 minutes. The resulting solids were then filtered and washed with deionized water to recover. The recovered filter cake was put into 1 L of deionized water and stirred again to prepare a catalyst mixed solution. The dried powder was recovered at 230 DEG C using a spray drier. The dried powder was calcined in air at 600 DEG C for 4 hours to obtain 95 g of the catalyst composition. The molar ratio of the metal used in the preparation of the catalyst was Fe / Co / Mo / Al = 2.0 / 2.0 / 0.5 / 5.5 and the apparent density of the prepared catalyst composition was 0.92 g / mL.

(Production Comparative Example 5) Production of a catalyst composition for synthesizing carbon nanotubes (without Mo)

Catalyst C-5 (Fe / Co / Al = 2.0 / 2.0 / 6.0)

2.0 mol of Fe (NO 3 ) 3 .9H 2 O, 2.0 mol of Co (NO 3 ) 2 .6H 2 O and 6.0 mol of Al (NO 3 ) 3 .9H 2 O were added to 1 L of deionized water, And the mixture was stirred for 2 hours to prepare a catalyst mixture solution in which all metal salts were completely dissolved. Then, the prepared catalyst mixture solution was pyrolyzed by spraying 0.3 L / hour of air into the reactor of the spray pyrolysis apparatus using air as a carrier gas. The spray pyrolysis conditions were as follows: the air pressure was 3 atm and the reactor internal temperature was 750 ° C., and the reactor was continuously operated for 120 minutes to collect a total of 67 g of the catalyst composition. The molar ratio of the metal used in the preparation of the catalyst was Fe / Co / Al = 2.0 / 2.0 / 6.0 and the apparent density of the prepared catalyst composition was 0.40 g / mL.

(Example 1) Synthesis of carbon nanotubes

Using the catalysts prepared in Production Examples 1 and 2 (Catalyst 1, Catalyst 2) and the catalysts prepared in Comparative Examples 1 to 4 (Catalysts C-1, C-2, C-3 and C-4) Invention In the fluidized bed carbon nanotube synthesis reactor shown in FIG. 2, a multi-walled carbon nanotube was prepared by dispersing and supplying the catalyst powder and spraying raw material gas at 600 to 900 占 폚 to thermally vaporize carbon on catalyst particles. The raw material gas used was ethylene as a carbon source gas and nitrogen gas as a carrier gas in a volume ratio of 3: 1. Table 1 shows the catalyst synthesis yield (%) and the apparent density of the prepared multi-wall carbon nanotubes.

The catalyst synthesis yield and the amount of synthesized carbon nanotubes were calculated according to the following equation.

Synthesis yield of catalyst (%) = amount of synthesis of carbon nanotubes / amount of catalyst input X 100

Synthesis amount of carbon nanotube = total weight of reaction product (M total ) - weight of catalyst (M cat )

catalyst
Input (g) Reaction temperature
(° C) Reaction gas
Flow rate (ml / min) Reaction time
(time) Catalyst yield
(%) Apparent density
(g / cc) Catalyst 1 100 750 Ethylene: nitrogen = 30: 10 1.5 2,420 0.04 Catalyst 2 2,740 0.035 Catalyst C-1 1,650 0.06 Catalyst C-2 1,390 0.09 Catalyst C-3 920 0.13 Catalyst C-4 1,140 0.12 Catalyst C-5 680 0.15

The yield of catalytic synthesis of the multi-walled carbon nanotubes produced by the continuous production process of the present invention using the catalyst composition [Fe p , Co q , Mo r , Al s ] of the present invention was 2,420% , Respectively. However, the catalyst synthesis yields were 1,650% and 680%, respectively, in the case of catalyst C-1 (difference in mole fraction of catalyst composition) and catalyst C-5 (without Mo), which were different from the catalyst composition of the present invention. In the case of the catalyst C-2 produced at the low pyrolysis temperature in the preparation of the catalyst by the spray pyrolysis method of the present invention, the catalyst synthesis yield was as low as 1,390%. On the other hand, the catalyst synthesis yields of catalyst C-3 prepared by co-precipitation method and catalyst C-4 prepared by spray drying method were as low as 920% and 1,140%, respectively.

Therefore, the catalyst synthesis yield of the multi-walled carbon nanotubes produced by the continuous production process of the present invention using the catalyst composition [Fe p , Co q , Mo r , Al s ] of the present invention was measured to be 1,400 to 3,000%.

100: Catalyst generating unit 110: Reactor
120: heating section 130: nozzle
140: solution supply part 150: gas supply part
160: outdoor gas supply pipe 170: outdoor air dispenser
200: Fluidized-bed carbon nanotube synthesizer 210: Reaction chamber
220: Catalyst supply part 222: Catalyst
224: catalyst supply pipe 230: raw material gas supply part
232: raw material gas 234: raw material gas supply pipe
240: Rotor 242: Rotating body
250: heating section 260: exhaust gas discharging section

Claims (10)

1) dissolving catalyst metal precursors (Fe, Co, Mo) and support precursor (Al) for producing carbon nanotubes in water, and obtaining catalyst powder for producing carbon nanotubes by spray pyrolysis;
The catalyst for preparing carbon nanotubes obtained in the step 1) is a catalyst composition comprising a main catalyst (Fe, Co), a cocatalyst (Mo) and a support (Al), and the catalyst has a carbon nanotube synthesis yield of 1,400 to 3,000%;
Synthesis yield of catalyst (%) = amount of synthesis of carbon nanotubes / amount of catalyst input X 100
2) supplying fluidized catalyst powder to the fluidized bed reactor and spraying the raw material gas, and thermally depositing carbon on the catalyst particles at 600 to 900 ° C; And
3) recovering and selecting the thermally deposited carbon nanotubes to obtain multi-walled carbon nanotubes;
In the continuous manufacturing process of multi-walled carbon nanotubes,
The step 1)
(I) A catalyst solution is prepared by dissolving a catalyst metal precursor (Fe, Co, Mo) for producing carbon nanotubes and a support precursor (Al) for preparing carbon nanotubes in water to prepare a catalyst solution. Air of 2 to 5 atm is supplied as a spray gas, And spraying the catalyst solution from the nozzle,
Ii) pyrolyzing pyrolysis of the catalyst solution sprayed into the reactor at 600-1,200 ° C, and
Iii) obtaining a catalyst powder for producing carbon nanotubes,
Including the
The apparent density of the obtained catalyst powder is 0.03 to 0.4 g / ml;
The step 2)
I) preheating the reaction chamber,
Ii) feeding catalyst powder from the bottom of the reaction chamber and fluidizing it in the reaction chamber,
Iii) injecting and supplying a source gas composed of a reaction gas and a carrier gas from the bottom of the reaction chamber,
Iv) vapor-depositing carbon on the catalyst particles fluidized in a rising air flow through the rotation of the rotor in a reaction chamber at 600 to 900 ° C,
V) exhausting the exhaust gas, and
Vi) selectively recovering multi-walled carbon nanotubes,
;
The catalyst for producing carbon nanotubes is represented by the following formula
Fe p , Co q , Mo r , Al s
In the above formula
p, q, r and s represent the mole fractions of Fe, Co, Mo and Al
p + q + r + s = 10
0.3? P? 3.0, 0.1? Q? 3.5, 0.05? R? 1.0 and 2.0? S? 8.5.
Wherein the multi-walled carbon nanotubes are continuously manufactured.
delete The process of claim 1, wherein the catalyst metal precursor and the support precursor are at least one selected from a metal nitrate, sulfate, alkoxide, chloride or carbonate.
The process according to claim 1, wherein the spray gas pressure is 2.5 to 4.0 atm and the pyrolysis temperature is 600 to 1,000 ° C.
delete The method according to claim 1, wherein the reaction gas is at least one carbon source gas selected from saturated or unsaturated hydrocarbons having 1 to 4 carbon atoms, carbon monoxide or benzene, and the carrier gas is an inert gas such as helium, nitrogen or argon. Wall carbon nanotube continuous manufacturing process.
delete The process for producing a multi-walled carbon nanotube according to claim 1, wherein the catalyst for synthesizing carbon nanotubes has the following mole fractions.
Fe p , Co q , Mo r , Al s
In the above formula
p, q, r and s represent the mole fractions of Fe, Co, Mo and Al
p + q + r + s = 10
0.5? P? 2.5, 0.2? Q? 3.0, 0.1? R? 0.8 and 2.5? S? 7.5.
delete delete
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