JPH0519341Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] The present invention relates to a carbon fiber manufacturing device, and in particular, to a device for manufacturing carbon fiber by a vapor phase growth method.
The present invention relates to a device with improved catalyst supply means.

[Prior Art] PAN-based and pitch-based carbon fibers have been commercially produced. However, PAN-based products are expensive, and pitch-based products have fatal drawbacks such as complicated processes and difficult quality control.

On the other hand, a vapor phase growth method has been proposed in recent years. Conventionally, vapor-grown carbon fibers are produced by placing a substrate made of porcelain such as alumina or graphite in an electric furnace, forming carbon growth nuclei, ultrafine particle catalysts such as iron, and nickel on this, and then forming carbonization particles such as benzene on this. Introduce a mixed gas of hydrogen gas and hydrogen carrier gas and heat to 950℃~
A method is known in which carbon fibers are grown on a substrate by decomposing hydrocarbons at a temperature of 1200°C.

However, with this method, length non-uniformity is likely to occur due to subtle temperature unevenness on the substrate surface and the density of surrounding fibers, and the gas that serves as a carbon source is consumed by the reaction. As a result, the fiber diameter differs considerably between the inlet and the outlet of the reaction tube, and since production occurs only on the substrate surface, the center of the reaction tube does not participate in the reaction, resulting in poor yields. , dispersion of ultrafine particles onto a substrate,
Continuous production is not possible due to the processes of reduction, growth, and fiber extraction that must be carried out independently, resulting in problems such as poor productivity.

Therefore, a method for producing carbon fibers has been proposed in which a mixed gas of a carbon compound gas, an inorganic or organic transition metal compound gas, and a carrier gas is reacted at high temperature (Japanese Patent Application Laid-open Nos. 60-54998, 1983-224816, etc.).

In conventional methods such as those disclosed in JP-A-60-54998 and 224816, the raw carbon compound and the catalyst-containing liquid are gasified in advance and then introduced into a reaction vessel, or the catalyst-containing liquid is introduced together with the raw carbon compound gas. The reaction is carried out by directly introducing the liquid into the reaction vessel.

[Problems to be solved by the invention] However, in the method in which the catalyst-containing liquid is gasified in advance and then introduced into the reaction vessel, the catalyst compound tends to condense, so it is difficult to integrate the gasification process and the reaction process. It is necessary to ensure sufficient heat retention between the two, which poses problems such as complicating the device configuration.

Further, when a catalyst-containing liquid is directly introduced into a reaction vessel, it is difficult to perform a quantitative reaction because it is unclear at which point in the reaction vessel the droplets will finish evaporating. In addition, since the evaporation rate varies depending on the liquid supply rate, the amount of catalyst vaporized will vary depending on the liquid supply rate, and the reaction will be directly affected. The disadvantage is that it is difficult to do.

[Means for Solving the Problems] The present invention solves the above-mentioned conventional problems and provides a carbon fiber manufacturing device that can quantitatively, smoothly and stably carry out reactions, and has a simple device configuration. It is something to do.

The carbon fiber manufacturing apparatus of the present invention includes a reaction vessel,
a means for introducing a carbon compound into the reaction vessel; a means for introducing a liquid catalyst into the reaction vessel; a raw heater for heating a reaction zone between the carbon compound and catalyst particles in the reaction vessel; In a carbon fiber manufacturing apparatus having a means for taking out a reactant from a reaction vessel, the catalyst introducing means includes a supply pipe provided such that a discharge port is located in a non-reaction zone within the reaction vessel;
a heater for heating the catalyst for heating the vicinity of the discharge port, and the distal end side of the supply pipe includes:
It is characterized in that the liquid catalyst flowing out from the tip side is oriented toward the installation part of the heater for heating the catalyst so as to come into contact with the installation part.

In the present invention, a liquid catalyst refers to a liquid compound containing a substance that becomes catalyst particles.

[Operation] In the apparatus of the present invention, the liquid catalyst supplied to the non-reaction zone in the reaction vessel through the supply pipe is heated and evaporated by the catalyst heater in the non-reaction zone. Then, the catalyst fine particles generated by the evaporation are sent to the reaction zone.

Moreover, the catalyst is supplied from a supply pipe whose tip is directed toward the installation portion of the catalyst heater so as to come into contact with the installation portion of the heater, so that the catalyst is reliably heated by the heater and efficiently evaporated.

As described above, the production apparatus of the present invention has an evaporation section for the catalyst-containing liquid in the non-reaction zone of the reaction vessel, and since the catalyst-containing liquid is supplied to the reaction vessel in a liquid state, the vaporized catalyst is Compared to conventional devices that maintain heat and send it to a reaction vessel, a heat insulating structure is not required and the device configuration is simple. Moreover, after the catalyst has been vaporized in advance near the supply and discharge ports of the non-reaction zone,
Because the catalyst enters the reaction zone, the reaction proceeds smoothly, the vaporization part of the catalyst is clear, and the amount of vaporization can be easily controlled by adjusting the heating temperature of the catalyst heater. There is almost no variation in the amount or supply rate, and the catalyst can be quantitatively and stably supplied to carry out an efficient reaction.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

1 and 2 are cross-sectional views showing the schematic configuration of carbon fiber manufacturing apparatuses according to different embodiments of the present invention.

Reference numeral 10 denotes a reaction vessel (reaction tube in this example), and at one end thereof, a supply pipe 12 for supplying a liquid compound (hereinafter referred to as "liquid catalyst") containing a substance to become catalyst particles is connected to its discharge. The outlet 12a is inserted into and connected to the reaction vessel 10 so as to be located upstream of a reaction zone 10a, which will be described later.
Further, a catalyst heater 14 for heating the vicinity of the discharge port 12a of the supply pipe 12 is provided close to the outer wall of the reaction vessel 10. Further, in the vicinity of the connection position of the supply pipe 12, a pipe 16 for supplying the raw material of the carrier gas supply pipe 16 and the carbon compound gas is connected. A flow rate control device (not shown) is provided in the middle of each of these pipes 16 and 18. A metering pump (not shown) is connected to the liquid catalyst supply pipe 12 to enable quantitative supply.

A collector 22 for carbon fibers 20, which are reaction products, is connected to the other end of the reaction vessel 10, and an exhaust gas extraction pipe 24 is connected to the carbon fiber collector 22.

A reaction zone 10a is set in the pipe between the carbon fiber collector 22 and the discharge port 12a of the liquid catalyst supply pipe 12, and a main heater 26 for heating is connected to the reaction zone 1.
It is provided on the outer wall of the reaction vessel corresponding to 0a.

In the embodiment apparatus shown in FIGS. 1 and 2, the liquid catalyst discharged from the discharge port 12a of the liquid catalyst supply pipe 12 is heated to about 100 to 120°C by the catalyst heating heater 14 near the discharge port 12a. After being vaporized, a supply pipe 16,
The carrier gas from 18 is sent together with the raw carbon compound gas, and heated to 600 to 1300°C by the main heater 26.
It reacts when heated to a certain degree. Through the reaction, a carbon compound is precipitated on the catalyst fine particles and carbon fibers grow. The carbon fibers produced in the reaction zone 10a of the reaction vessel are introduced into the carbon fiber collector 22 together with a carrier gas. As this collection method, various conventionally known methods such as gravity sedimentation method and electrostatic precipitation method can be employed. Note that the carbon fiber collector 22 also plays a role of cooling the generated carbon fibers. The carrier gas extracted from the carbon fiber collector 22 may be directly introduced into the exhaust treatment means and discharged, but it may also be purified and recirculated for use.

The embodiment shown in FIG.
The tip of the catalyst 2 is bent downward into an L shape, and the liquid catalyst is dripped toward the installation part of the catalyst heater 14, so that the catalyst is efficiently vaporized.

In the embodiment shown in FIG. 2, the supply pipe 12 is bent downward as in FIG.
A recess 28 is formed on the wall surface of the reaction vessel 10 where the reaction vessel 2a is located.
is provided. A catalyst heater 14 is installed following the shape of this recess. In the device of this embodiment, the heating of the catalyst heater 14 to the discharge port 12a is relaxed, and caulking at the discharge port 12a portion is prevented.

Note that the devices shown in FIGS. 1 and 2 are only examples of the present invention, and the present invention is not limited to the illustrated devices in any way. In the apparatus of the present invention, a laser beam may be used to activate the raw carbon compound and the catalyst. When using a laser beam in combination, it is possible to significantly reduce the energy cost required for heating, reduce the temperature of the reaction vessel wall, and prevent products from adhering to the vessel wall to improve yield. I can do it.

The apparatus of the present invention is suitable for a horizontal reaction apparatus as shown in FIGS. 1 and 2, but it may of course be of a vertical type.

Hereinafter, the raw material carbon compound, catalyst, carrier gas, etc. used in the present invention will be explained in detail.

The carbon compound in the present invention refers to all carbon compounds that can be gasified, including CCl ₄ ,
It covers all inorganic and organic compounds such as CHCl ₃ , CH ₂ Cl ₂ , CH ₃ Cl, CO, and CS ₂ . Particularly useful compounds are aliphatic hydrocarbons and aromatic hydrocarbons. In addition to these, nitrogen, oxygen, sulfur,
Derivatives containing elements such as fluorine, iodine, phosphorus, arsenic, etc. can also be used. Some specific examples of individual compounds include methane (natural gas may also be used), alkane compounds such as ethane, alkene compounds such as ethylene and butadiene, alkyne compounds such as acetylene, benzene, toluene, styrene, etc. aryl hydrocarbon compounds, aromatic hydrocarbons having condensed rings such as indene, naphthalene, and phenanthrene;
Cycloparaffin compounds such as cyclopropane and cyclohexane, cycloolefin compounds such as cyclopentene and cyclohexene, alicyclic hydrocarbon compounds having condensed rings such as steroids, sulfur-containing fats such as methylthiol, methylethyl sulfide, and dimethylthioketone Group compounds, phenylthiol, diphenyl sulfide, and other yellow aromatic compounds; benzothiophene, thiophene, and other sulfur-containing heterocyclic compounds; The first petroleum, the second petroleum such as kerosene, turpentine, camphor oil, and pine oil, the third petroleum such as heavy oil, and the fourth petroleum such as gear oil and cylinder oil can also be effectively used. It goes without saying that mixtures of these can also be used.

In the present invention, the catalyst includes an inorganic transition metal compound, an inorganic Si inorganic compound, an organic transition metal compound,
Examples include organic compounds of Si. This inorganic transition metal compound is an inorganic transition metal compound that can be vaporized alone, or is soluble in water or at least one kind of water or organic solvent (a carbon raw material compound may be used as the organic solvent). Alternatively, inorganic compounds of transition metals that can be suspended as fine particles are targeted. Transition metals include iron, nickel,
Cobalt, molybdenum, vanadium, palladium, etc. are preferred, and iron is particularly preferred. The former inorganic transition metal compound that can be vaporized alone is Fe.
(NO) ₄ , FeCl ₃ , Fe(NO) ₃ Cl, Fe(NO) ₂ , Fe
(NO) ₂ I, represented by FeF ₃ . In addition to the compounds listed as the former, the latter includes Fe(NO ₃ )
₂ , FeBr ₃ , Fe(HCOO) ₃ , C ₂₇ H ₄₂ FeN ₉ O ₁₂ , Fe
(SO ₄ ) ₃ , Fe(SCN) ₃ , (C ₅ H ₅ ) ₂ Fe, (C ₅ H ₅ ) ₂ Ni,
Fe(NO) ₃ NH ₃ , Co(NO) ₂ Cl, Ni(NO) Cl, Pd
Representative examples include (NO) ₂ Cl ₂ and NiCl ₂ .

The organic transition metal compounds in the present invention include alkyl metals in which an alkyl group and a metal are bonded, allyl complexes in which an allyl group and a metal are bonded, and π-complexes in which a carbon-carbon double bond or triple bond is bonded to a metal. It is an organic transition metal compound typified by chelate type compounds. In addition, here, the transition metals are:
This refers to scandium, titanium, panadium, chromium, manganese, iron, cobalt, nickel, yttrium, zirconium, niobium, molybdenum, ruthenium, rhodium, palladium, tantalum, tungsten, rhenium, iridium, and platinum. Those belonging to the periodic table group, among which iron, nickel, and cobalt are particularly preferred, with iron being the most preferred.

Furthermore, in the presence of a sulfur-containing carbon compound or an inorganic sulfur compound, an inorganic compound of silicon can also be used. For example, the above-mentioned inorganic metal compounds in which the metal is replaced with Si or silicon carbide can be used. Furthermore, various organosilicon compounds may also be used.

The organic silicon compound includes, for convenience, silane and halogen silane in addition to organic compounds having a silicon-carbon bond. Organic compounds with carbon-silicon bonds include organosilanes such as tetramethylsilane and methyltriphenylsilane; organohalogensilanes such as chlorodifluoromethylsilane and promtripropylsilane; methoxytrimethylsilane, trimethylphenoxysilane, etc. organoalkoxysilane; organoacetoxysilane such as diacetoxydimethylsilane, acetoxytripropylsilane; hexaethyldisilane,
Organopolysilanes such as hexaphenyldisilane and octaphenylcyclotetrasilane; organohydrogenosilanes such as dimethylsilane and triphenylsilane; cyclosilanes represented by (SiH ₂ ) _o ; triphenylsilazane, hexaethyldisilazane, hexa Organosilazane such as phenylcyclotrisilazane, (SiH ₂ NH) _o Organosilanols such as diethylsilanediol and triphenylsilanol; Organosilanols such as trimethylsilylacetic acid and trimethylsilylpyropionic acid; Trimethylsilylacetic acid,
Organosilane carboxylic acids such as trimethylsilylpropionic acid; silicone isocyanates such as trimethylsilicon isocyanate and diphenylsilicon diisocyanate; organosilicon isothiocyanates such as trimethylsilicon isothiocyanate and diphenylsilicon diisothiocyanate; cyanide organosilicon esters such as triethylsilyl; hexamethyldisylthian;
Silthian such as tetramethylcyclodisilthian; cyclosilthian represented by (SiH ₂ S) _o ;
Examples include organosylmethylenes such as hexamethyldisylmethylene and octamethyltrisylmethylene; organosiloxanes such as hexamethyldisiloxane and hexapropyldisiloxane; however, compounds containing other carbon-silicon bonds may also be used. . It is also possible to use mixtures of these.

The carrier gas in the present invention refers to all gases that are not directly involved in the reaction. Examples include H ₂ gas, N ₂ gas, NH ₃ gas, Ar gas, He
Gas, Kr gas, or a mixture of these gases. Among these, H ₂ gas is usually used.

According to the carbon fiber manufacturing apparatus of the present invention, the length is usually about 10 μm to 500 mm, and the diameter is about 10 μm to 500 mm.
Carbon fibers of about 0.1 to 300 μm can be easily and efficiently produced.

[Effects of the invention] As detailed above, according to the carbon fiber manufacturing apparatus of the invention, the reaction proceeds smoothly because the catalyst is vaporized in advance and then sent to the reaction zone.

It is easy to control the amount of catalyst supplied and the amount of vaporization, and the vaporized catalyst can be quantitatively introduced into the reaction zone.

The device configuration is simple.

These effects are achieved, and carbon fibers can be efficiently produced at low cost by the vapor growth method.

[Brief explanation of the drawing]

Each of FIGS. 1 and 2 is a sectional view showing a schematic configuration of a carbon fiber manufacturing apparatus according to an embodiment of the present invention. 10...Reaction container, 10a...Reaction zone, 1
2...Liquid catalyst supply pipe, 12a...Discharge port, 1
4...Heater for catalyst heating, 20...Carbon fiber, 2
6...Main heater.

Claims (1)

[Claims for Utility Model Registration] A reaction vessel, a means for introducing a carbon compound into the reaction vessel, a means for introducing a liquid catalyst into the reaction vessel, and a combination of the carbon compound and catalyst particles in the reaction vessel. In a carbon fiber manufacturing apparatus having a main heater for heating a reaction zone and a means for taking out a reactant from the reaction vessel, the catalyst introduction means is configured such that a discharge port is located in a non-reaction zone within the reaction vessel. and a catalyst heating heater for heating the vicinity of the discharge port; A carbon fiber manufacturing apparatus characterized in that the carbon fiber manufacturing apparatus is oriented toward the installation part of a heater so as to be in contact with the installation part.