JP3934083B2 - Fullerene production method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a fullerene which is a carbon material, particularly a fullerene having a molecular structure of C60, C70, C76, C78, C82 and C84 by incompletely burning a hydrocarbon raw material.
[0002]
[Prior art]
In recent years, as shown in Patent Document 1, fullerenes called C60 and C70, which are closed-shell carbon clusters, have been proposed as new carbon materials. Since these materials are expected to exhibit unique properties due to their special molecular structure, they are expected to be applied in fields such as diamond coating, battery materials, paints, heat insulating materials, lubricants, pharmaceuticals, and cosmetics. .
As a fullerene production method, for example, as shown in Patent Document 2, a method of producing a fullerene by burning a carbon compound has been proposed, and now an aromatic hydrocarbon such as benzene and an oxygen-containing gas are introduced into a reaction furnace. A method of producing fullerene by incomplete combustion under reduced pressure is considered to be most effective.
[0003]
[Patent Document 1]
Japanese Patent No. 2802324
[Patent Document 2]
Japanese National Publication No. 6-507879
[0004]
[Problems to be solved by the invention]
However, in the currently used combustion method using a reactor, the hydrocarbon raw material, which is a raw material, is once vaporized, but is provided to the reactor without any special preheating outside the reactor. Therefore, there has been a problem that the temperature in the reactor does not rise sufficiently and the production efficiency of fullerene is poor.
Further, when the temperature of the vaporized hydrocarbon raw material is lowered and a part of the hydrocarbon raw material is condensed in a tube or a nozzle, the flow of the hydrocarbon raw material or oxygen is deteriorated and the reaction is not stable.
Furthermore, in the production of fullerene by the combustion method, it seems that it is better to react the hydrocarbon raw material in a specific high temperature region under reduced pressure, depending on the type, but the hydrocarbon raw material and the oxygen-containing gas Only by controlling the equivalence ratio, it was difficult to set the inside of the reactor to an appropriate condition. In particular, when detecting the optimum conditions by changing the type of hydrocarbon raw material or the oxygen concentration in the oxygen-containing gas, it is necessary not only to control the equivalence ratio but also to have a means to easily control the reaction temperature from the outside. there were.
This invention is made | formed in view of this situation, and it aims at providing the manufacturing method of fullerene which can manufacture fullerene continuously in large quantities and efficiently.
[0005]
[Means for Solving the Problems]
The fullerene production method according to the first aspect of the present invention, which meets the above object, comprises a hydrocarbon raw material and an oxygen-containing gas. Decompressed In a method for producing fullerene by supplying to a reactor and incompletely burning them in the reactor,
Composed of C6-C20 aromatic hydrocarbon The hydrocarbon feedstock, Vaporized by a vaporizer and by a first heat exchanger Than vaporization temperature 20 ℃ or more Higher than the autoignition temperature in the presence of oxygen 50 ℃ or more Preheat to a lower temperature range,
The oxygen-containing gas is preheated by a second heat exchanger to a temperature range higher than the vaporization temperature of the hydrocarbon raw material and lower than the self-ignition temperature by 50 ° C., and then the first and second heat exchangers are The hydrocarbon raw material and the oxygen-containing gas that have passed each are mixed by a premixing device, The reactor Burner section To supply.
This can prevent the hydrocarbon feedstock from liquefying in the pipes and nozzles, stabilize the operation, increase the combustion temperature of the reactor (more precisely, the incomplete combustion temperature, the same shall apply hereinafter), and Manufacturing efficiency is increased.
[0006]
[0007]
In the method for producing fullerene according to the first invention, the oxygen-containing gas Is It is preferable that the temperature be higher than the vaporization temperature of the hydrocarbon raw material and be preheated to a temperature range lower by 50 ° C. or more than the self-fire temperature of the hydrocarbon raw material. As a result, in addition to the hydrocarbon fuel, the oxygen-containing gas is also preheated, so that the temperature of the combustion gas in the reactor further increases. When the oxygen-containing gas is preheated higher than the vaporization temperature of the hydrocarbon raw material, even if the hydrocarbon raw material and the oxygen-containing gas are mixed, the temperature of the hydrocarbon raw material does not decrease and the hydrocarbon raw material is not liquefied.
[0008]
It should be noted that the hydrocarbon raw material should be 20 ° C. higher than its vaporization temperature and 50 ° C. lower than the self-ignition temperature of the hydrocarbon raw material, even if there is an inadvertent disturbance such as piping or nozzles. This is because the hydrogen raw material suddenly falls below the vaporization temperature or the self-ignition temperature does not occur and the explosion reaction does not occur. Further, considering the safety side, the preheating temperature of the hydrocarbon raw material is 50 ° C. or higher than the self-ignition temperature. In some cases, it may be lower than 100 ° C.
[0009]
[0010]
[0011]
[0012]
[0013]
[0014]
In the method for producing fullerene by supplying a hydrocarbon raw material and an oxygen-containing gas in a predetermined equivalence ratio to a reaction furnace and incompletely combusting them in the reaction furnace, the hydrocarbon raw material and the oxygen Preheat the contained gas and control the preheating temperature to control the optimum combustion temperature in the reactor if you did this Thus, the temperature of the combustion gas in the reactor can be changed freely to some extent. For example, when searching for optimum fullerene recovery conditions, or during operation (hydrocarbon raw materials, oxygen-containing gas components) , C60, C70, etc.).
[0015]
In the present invention, the self-ignition temperature of the hydrocarbon raw material is the minimum ignition temperature of the hydrocarbon raw material in a stable state. Specifically, the hydrocarbon raw material in a vaporized state and the theoretical combustion amount of air are mixed. The temperature at which the hydrocarbon raw material ignites in a state where the pressure is 1 atm and the temperature is gradually increased.
The vaporization temperature refers to the temperature at which the hydrocarbon raw material is completely vaporized at the pressure at which the hydrocarbon raw material is placed, and refers to the boiling point when the hydrocarbon raw material is liquid. This vaporization temperature varies with pressure.
The oxygen-containing gas is a gas obtained by diluting oxygen with argon gas or helium gas, a gas obtained by diluting oxygen with nitrogen or air, or the air itself and air with argon, helium, nitrogen, in addition to the case where oxygen is 100%. A gas diluted with an inert gas such as
In the present invention, fullerene refers to a group of spherical shell-like carbon molecules including C60 and C70, and in addition to C60 and C70, C74, C76, C78, C80, C82, C84, C86, C88, There are C90, C92, C94, C96, etc., but it may be spherical, and there is no upper limit to the number of carbon atoms.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Subsequently, an embodiment of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
FIG. 1 is a schematic configuration diagram of a fullerene production facility to which a fullerene production method according to an embodiment of the present invention is applied.
As shown in FIG. 1, a fullerene production facility 10 to which a fullerene production method according to an embodiment of the present invention is applied includes a fullerene reaction furnace 11 and fullerenes from gaseous substances discharged from the reaction furnace 11. It has a separation device 12 that collects soot, a gas cooler 13 that cools the gas discharged from the separation device 12, and a decompression device 14 that includes a vacuum pump that sucks the gas cooled by the gas cooler 13. . These will be described in detail below.
[0017]
In this embodiment, since the fullerene is generated by a combustion method, the pressure inside the reactor 11 is reduced to atmospheric pressure, preferably close to vacuum (for example, 10 to 100 torr). It is said. A premixed hydrocarbon raw material (gaseous) and an oxygen-containing gas inlet 15 are provided at one end (in this embodiment, the bottom) of the reaction furnace 11, via a burner portion 17 provided inside. These mixed gases are supplied.
[0018]
The hydrocarbon raw material and the oxygen-containing gas supplied to the reaction furnace 11 are heat-treated by heat exchangers 20 and 21 provided in the middle of the pipe lines 18 and 19, respectively. In particular, aromatic hydrocarbons having 6 to 20 carbon atoms such as benzene, toluene, xylene, naphthalene, methylnaphthalene, anthracene, and phenanthrene are preferably used as the hydrocarbon raw material, but these are liquid or solid at room temperature. Therefore, it is necessary to supply the reaction furnace 11 once in a gas state with the vaporizer, and the vaporizer 22 may be disposed upstream of the heat exchanger 20. In addition, although it is preferable to use both the heat exchangers 20 and 21, depending on the case, either one of the heat exchangers 20 and 21 is omitted and only one of the hydrocarbon raw material and the oxygen-containing gas is preheated. You may make it do.
[0019]
The hydrocarbon raw material and the oxygen-containing gas that have passed through one or both of the heat exchangers 20 and 21 are supplied to the reaction furnace 11 via the premixing device 23. The premixing device 23 is omitted, and the hydrocarbon raw material and the oxygen-containing gas are independently supplied into the reaction furnace 11, and the hydrocarbon raw material and the oxygen-containing gas are supplied by the premixing device provided in the reaction furnace 11. May be mixed. Alternatively, the burner unit may be specially devised so that the hydrocarbon raw material and the oxygen-containing gas are blown out from small nozzles (micro jet holes) provided alternately and alternately, and mixed in the combustion region in the reactor. .
[0020]
In this embodiment, a premixing device 23 is provided outside the reactor 11, and heat exchangers 20 and 21 for preheating hydrocarbon raw materials and oxygen-containing gases are further provided upstream of the premixing device 23. However, the vaporized hydrocarbon raw material and the oxygen-containing gas are directly introduced into the premixing device, and the hydrocarbon raw material and the oxygen-containing gas mixed by the premixing device are preheated by a heat exchanger (that is, a heater). The temperature can also be raised through. In this case, it is natural that the preheating temperature is a temperature at which the mixed hydrocarbon raw material and the oxygen-containing gas are not spontaneously ignited. Further, in the case where the burner unit 17 in the reaction furnace 11 is also preheated, the burner The mixed gas to be ejected from the part 17 is set to a low temperature so that the burner part 17 does not spontaneously ignite. Therefore, when the preheating temperature in the burner unit 17 is A ° C. and the self-ignition temperature of the hydrocarbon raw material is B ° C., the above preheating heat exchanger uses a mixed gas of the hydrocarbon raw material and the oxygen-containing gas. The maximum heating temperature is (B-A-C) ° C. Here, C is a temperature that allows for safety, and is an optimum temperature selected from 10 to 80 ° C. (for example, 20 ° C., 50 ° C., 60 ° C., 100 ° C., 150 ° C.).
[0021]
The heat exchanger 20 heats the hydrocarbon raw material, and the supplied hydrocarbon raw material is, for example, 10 ° C. or higher (more preferably 20 ° C. or higher, more preferably 30 ° C. or higher) higher than the vaporization temperature of the hydrocarbon raw material. Heating can be performed in a temperature range that is 10 ° C. (more preferably 20 ° C. or higher, more preferably 50 ° C. or higher) lower than the self-ignition temperature of the hydrocarbon raw material in the presence. As a result, the hydrocarbon raw material is not condensed and liquefied in the nozzles of the pipe 18 and the burner unit 17, and the oxygen-containing gas is mixed with the hydrocarbon raw material in a portion other than the combustion region in the reaction furnace 11. If it prevents spontaneous ignition.
[0022]
A burner unit 17 is provided in the reaction furnace 11. In this embodiment, since the hydrocarbon raw material and the oxygen-containing gas (hereinafter sometimes referred to as “mixed gas”) that are premixed in a gaseous state are supplied to the reaction furnace 11, these gases are The gas is supplied into the reaction furnace 11 through a nozzle made of a porous member provided in the burner part 17 and burns in a reduced pressure combustion region. The burner part 17 made of a porous member injects the mixed gas into the reaction furnace 11 at a slower injection speed, and the burner part 17 itself is also heated by the heat from the combustion region, resulting in further heating of the mixed gas. Is going. The oxygen-containing gas is mainly oxygen, but contains an inert gas such as argon as necessary.
[0023]
At the other end of the reaction furnace 11, a discharge port 24 for high-temperature exhaust gas containing fullerene and soot generated in the reaction furnace 11 is provided. The separation device 12 is connected to the discharge port 24 via a gas temperature lowering means 25. In this embodiment, the gas temperature lowering means 25 has a pipe 26 having a predetermined length whose peripheral wall is cooled to a predetermined temperature, and a soot-like substance-containing air flow in a turbulent state at a high temperature passes through the pipe 26. As a result, the heat is removed from the surroundings, and the temperature is lowered to a predetermined temperature (for example, higher than the liquefaction temperature of the hydrocarbon raw material and lower than the solidification temperature of fullerene, for example, 400 to 500 ° C.) and sent into the separation device 12.
[0024]
The separation device 12 is for separating the solid content in the soot-containing airflow generated from the reaction furnace 11 and the airflow, and includes a heat-resistant filter 27 for high temperature inside. Since the heat-resistant filter 27 allows the vaporized polycyclic aromatic compound to pass through and collects fullerene and a carbon-based polymer component (saddle-like material), it has a heat-resistant temperature of 400 to 500 ° C. depending on the temperature of the gas. Yes.
[0025]
The structure of the separating device 12 is a bag filter structure used in a normal dust collector or the like, and this bag filter is constituted by the heat-resistant filter 27 described above. Examples of such a heat resistant filter 27 include a sintered metal filter manufactured by Nihon Pall and a sintered metal filter manufactured by Fuji Filter. The size of the filter openings is appropriately selected depending on the combustion conditions for generating fullerene and the properties of the soot-like substance.
Further, when the temperature of the gas-containing substance-containing air flow is lowered to about 150 ° C. or less by the gas temperature lowering means 25, the filter inside the separation device 12 does not need to be a high-temperature heat-resistant filter, but nylon, Teflon (registered trademark) A commonly used filter of the material such as can be used.
[0026]
The separation device 12 is provided with a reverse cleaning mechanism 28 for removing solidified substances (for example, a carbon-based polymer component composed of soot and the like and fullerene or a carbon-based polymer component) periodically attached to the upper portion thereof. The reverse cleaning mechanism 28 includes a tank 29 for storing a high-pressure inert gas (for example, nitrogen or argon) and a solenoid valve 30, and the heat-resistant filter is opened by periodically opening the solenoid valve 30 for a short time. The gas is put into the inside 27, the solidified material adhering to the periphery is dropped downward, and the discharge valve 31 is opened so that it can be discharged to the outside. A gas outlet 32 for discharging the gas that has passed through the heat-resistant filter 27 to the outside is provided at the top of the separation device 12. The reverse cleaning may be performed in a pulse manner using a pulse jet mechanism.
[0027]
A gas cooler 13 is provided at the gas outlet 32 of the separation device 12. This gas cooler 13 has the same or similar structure as a normal heat exchanger, and reduces the temperature of the gas flowing into the decompression device 14 to reduce the load on the decompression device 14. In addition, hydrocarbon raw materials (for example, polycyclic aromatic compounds) and moisture contained in the air current are liquefied and discharged from the lower drain.
The decompression device 14 following the gas cooler 13 is composed of a normal vacuum pump. In addition, since the sublimation temperature of fullerene also changes depending on the degree of vacuum, the decompression device 14 is selected so as to achieve a pressure at which fullerene can be recovered most efficiently from the amounts of carbonaceous raw material, oxygen, and inert gas supplied.
[0028]
Next, a method for producing fullerene according to an embodiment of the present invention will be described with reference to FIG.
Process (1)
Step (1) of the present embodiment is a step of preheating either one or both of the hydrocarbon raw material and the oxygen-containing gas before supplying them into the reaction furnace 11.
After gasifying the hydrocarbon raw material (for example, toluene) with the vaporizer 22, the heat exchanger 20 is 10 ° C. higher than the vaporization temperature of the hydrocarbon raw material and 10 ° C. higher than the self-ignition temperature of the hydrocarbon raw material in the presence of oxygen. Preheating to a low temperature (more preferably, a temperature that is 20 to 30 ° C. or more higher than the vaporization temperature of the hydrocarbon raw material and 50 to 20 ° C. or lower than the self-ignition temperature in the presence of oxygen of the hydrocarbon raw material) The reason for this is that if the hydrocarbon raw material is heated to a temperature sufficiently higher than its vaporization temperature, it will not be easily liquefied by touching the surrounding wall while passing through the piping or nozzle, and by preheating the hydrocarbon raw material, The combustion temperature in the reaction furnace 11 can be increased, whereby the production efficiency of fullerene can be further increased.
[0029]
Actually, when toluene is employed as the hydrocarbon raw material, it is preferably preheated to about 160 to 250 ° C. (more specifically, 170 to 220 ° C.). The vaporization temperature of toluene is 1 kgf / cm. ² G is about 136 ° C., and the auto-ignition temperature of standard state toluene is about 480 ° C.
In addition, when the hydrocarbon raw material is a plurality of components (for example, toluene and anthracene), the lowest temperature is determined based on the substance having the highest vaporization temperature (solidification temperature) among the components, It is natural to determine the maximum temperature based on the lowest self-ignition temperature.
In addition, steam, high boiling point oil, combustion exhaust gas, or the like is preferably used as the heat medium for heating the heat exchangers 20 and 21.
[0030]
On the other hand, an oxygen-containing gas (100% oxygen gas is used in this embodiment) is preheated by the heat exchanger 21. In this case, the preheating temperature of the oxygen-containing gas is higher than normal temperature (for example, 25 ° C.) and lower than the self-ignition temperature of the hydrocarbon raw material by 10 ° C. The temperature is 20 to 50 ° C. or lower).
[0031]
Thus, the hydrocarbon raw material and the oxygen-containing gas can be rapidly heated by separately heating the hydrocarbon raw material and the oxygen-containing gas. This is because the hydrocarbon raw material and the oxygen-containing gas alone do not cause a combustion reaction, so that there is no particular problem even if they are partially heated to a temperature higher than the self-ignition temperature of the hydrocarbon raw material, for example. There is an advantage that the entire apparatus can be reduced in size. On the other hand, when preheating is performed in a state in which a hydrocarbon raw material and an oxygen-containing gas are mixed in an appropriate ratio, there is a problem that explosion combustion may occur even if there is a high temperature part in the heating.
[0032]
The hydrocarbon raw material and the oxygen-containing gas preheated by the heat exchangers 20 and 21 are mixed by the premixing device 23. This premixing device 23 may be one that guides two gases from separate inlets and naturally mixes them inside. In some cases, in order to further improve the stirrability, a static mixer or ejector type It may be.
It is preferable that both the hydrocarbon raw material and the oxygen-containing gas supplied to the premixing device 23 are preheated. That is, for example, if both are mixed at a temperature lower than the self-ignition temperature of the hydrocarbon raw material, the temperature of the mixed gas can be maximized, and as a result, the combustion temperature in the reaction furnace 11 can be further increased. More preferably, depending on the case, either one of the hydrocarbon raw material and the oxygen-containing gas may be heated and the other may not be heated, or may be heated to a temperature lower than that of the one gas.
[0033]
The hydrocarbon raw material and the oxygen-containing gas that have been premixed are supplied into the reaction furnace 11 via the premixing device 23, but when a preheating device is further provided in the reaction furnace 11, the mixing immediately before blowing out from the nozzle The temperature of the hydrocarbon raw material and oxygen-containing gas discharged from the heat exchangers 20 and 21 so that the temperature of the gas is 10 ° C. or more, preferably 20 to 50 ° C. or lower than the self-ignition temperature of the hydrocarbon raw material. Is adjusted in consideration of the pressure.
[0034]
Process (2)
The ratio of the hydrocarbon raw material supplied into the reaction furnace 11 and the oxygen-containing gas was increased in the ratio of the hydrocarbon raw material in an equivalence ratio of 2.5 to 3.5. As a result, the hydrocarbon raw material is incompletely burned in the combustion region in the reaction furnace 11, and fullerene is generated from a part of the hydrocarbon raw material.
When producing fullerene by a combustion method, the pressure condition is generally performed under reduced pressure with respect to atmospheric pressure, and the degree of reduced pressure may be selected as appropriate. As specific pressure conditions, for example, the exhaust amount of the decompression device 14 and the amount of the hydrocarbon raw material and the oxygen-containing gas supplied are adjusted so as to be 20 to 100 Torr (more preferably 30 to 50 Torr). ing.
[0035]
Further, the temperature condition of the optimum combustion temperature in the reaction furnace 11 may be appropriately selected according to the pressure conditions described above, and among these, 1600 to 2000 ° C is preferable, and 1700 to 1900 ° C is particularly preferable.
In this embodiment, since the polycyclic aromatic compound is used as the hydrocarbon raw material in the soot-like substance obtained by the combustion method, fullerene and polycyclic aromatic hydrocarbon are included. The remainder other than these is usually a polymer hydrocarbon, carbon black, or the like (carbon-based polymer component) having a carbon graphite structure as a skeleton and a few hydrogen atoms.
The soot-like substance obtained in step (2) preferably contains 5% by weight or more of fullerene, more preferably 10% by weight or more, and particularly preferably 15% by weight or more.
In addition, the fullerene produced according to the present embodiment is not limited in the number of carbons as long as it has a fullerene structure, but is usually a fullerene having 60 to 84 carbon atoms, and among them, the ratio of C60 and C70 is all fullerenes. The content is preferably 50% by weight or more, more preferably 70% by weight or more, and particularly preferably 80% by weight or more.
[0036]
The soot-containing substance-containing airflow, which is an exhaust gas generated in the reaction furnace 11 in the step (2), usually has a slow speed and a temperature of 800 ° C. or higher. Therefore, the temperature is lowered to about 400 to 500 ° C. by the gas temperature lowering means 25. This temperature is a temperature at which the unburned hydrocarbon raw material contained in the exhaust gas can maintain a gaseous state, and finally the unburned hydrocarbon raw material (polycyclic aromatic compound) is gas in the separator 12. It is the temperature which can be passed while maintaining
[0037]
Step (3)
In the step (3), the fullerene and the soot-like substance are separated by the separation device 12 from the soot-containing gas stream containing the fullerene, the polycyclic aromatic compound and the carbon-based polymer component obtained in the above-mentioned step (2). Remove and collect.
As a separation method, fullerene is separated from a mixture of fullerene and a carbon-based polymer component using a solvent. As an extraction solvent for obtaining an extract solution in which fullerene is dissolved, a solvent containing an aromatic hydrocarbon is preferably used. The aromatic hydrocarbon is a hydrocarbon compound having at least one benzene nucleus in the molecule, specifically, benzene, toluene, xylene, ethylbenzene, n-propylbenzene, isopropylbenzene, n-butylbenzene, sec- Butylbenzene, tert-butylbenzene, 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene, 1,3,5-trimethylbenzene, 1,2,3,4-tetramethylbenzene, 1,2 Alkylbenzenes such as 1,3,5-tetramethylbenzene, diethylbenzene, and cymene, alkylnaphthalenes such as 1-methylnaphthalene, and tetralin. Of these, 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene and tetralin are preferred.
[0038]
Process (4)
This process relates to the treatment of the exhaust gas that has passed through the separation device 12, but since it contains a polycyclic aromatic compound inside, it is liquefied by the gas cooler 13 and discharged from the drain provided at the bottom. To do. Since the drain and the gas cooler 13 contain a large amount of fullerene, the inside is periodically washed with a solvent and cleaned to recover the fullerene.
[0039]
As another method for recovering fullerene from exhaust gas generated from the reaction furnace 11, for example, a separation device is provided in two stages, a soot-like substance is recovered by an upstream separation device, and a fullerene is recovered by a downstream separation device. There is also a method of doing.
As a method of separating the soot-like substance and fullerene, the present invention can be applied to a method of vaporizing fullerene by reheating and recovering fullerene by reheating, in addition to a method using a solvent.
[0040]
In the above embodiment, the hydrocarbon raw material and the oxygen-containing gas are preheated independently from each other outside the reaction furnace 11, but may be preheated independently or in a mixed state inside the reaction furnace 11. .
[0041]
【Example】
EXAMPLES Examples carried out for confirming the operation and effects of the present invention will be described below. However, the present invention is not limited to the following examples unless it exceeds the gist of the present invention.
[0042]
Example 1
Toluene, which is an example of a polycyclic aromatic compound, was used as a hydrocarbon raw material, and pure oxygen was used as the oxygen-containing gas. Toluene was once heated by the vaporizer 22 to be gaseous, and then heated to about 180 ° C. by the heat exchanger 20. On the other hand, the oxygen-containing gas was supplied from the oxygen tank to the heat exchanger 21 and heated here to 180 ° C.
At this time, the flow rate of toluene was 219.5 g / min (143.15 mol / h), and oxygen was 163.1 N liter / min (436.88 mol / h). The pressure in the reactor 11 was 40 Torr, and the flow rate of the burner gas (immediately after leaving the nozzle) was 2.32 m / sec. When fullerene was produced under such conditions, 130 g / h fullerene (C60) per hour could be produced.
[0043]
(Comparative Example 1)
On the other hand, when the heating degree of the hydrocarbon raw material and the oxygen-containing gas is weakened by the heat exchangers 20 and 21 and supplied to the reactor 11, the temperature of the toluene gas becomes 160 ° C., and the temperature of the oxygen-containing gas becomes 40 ° C. When fullerene was produced by flowing substantially the same amount of toluene and oxygen-containing gas in Example 1, 90 g / h fullerene (C60) per hour could be produced.
From the above examples, it can be understood that the production amount of fullerene increases when the hydrocarbon raw material and the oxygen-containing gas are sufficiently preheated.
[0044]
(Example 2)
When the heating conditions of the heat exchangers 20 and 21 were changed to change the temperature of the hydrocarbon raw material and the oxygen-containing gas, the temperature of the exhaust gas generated from the reaction furnace 11 was measured as follows.
Hydrocarbon feed 140 ℃ 140 ℃ 180 ℃ 250 ℃ 300 ℃
Oxygen-containing gas 25 ° C 140 ° C 180 ° C 250 ° C 300 ° C
Exhaust gas temperature 1680 ° C 1700 ° C 1720 ° C 1751 ° C 1772 ° C
Fullerene
Production 80g / h 105 g / h 130g / h 135g / h 142g / h
[0045]
(Example 3)
When the heating conditions of the heat exchangers 20 and 21 were changed to change the temperature of the hydrocarbon raw material and the oxygen-containing gas, the temperature of the exhaust gas generated from the reaction furnace 11 was measured as follows.
Hydrocarbon raw material 180 ℃ 140 ℃ 150 ℃
Oxygen-containing gas 25 ° C 350 ° C 250 ° C
Exhaust gas temperature 1695 ° C 1740 ° C 1725 ° C
Fullerene production 110 g / h 130 g / h 110 g / h
From Examples 2 and 3, when the temperature of the hydrocarbon raw material and the oxygen-containing gas is increased, the combustion temperature in the reaction furnace 11 increases, and eventually the temperature of the hydrocarbon raw material and the oxygen-containing gas is increased by the heat exchangers 20 and 21. It turns out that the combustion temperature in the reactor 11 can be controlled by controlling. It can also be seen that it is efficient to simultaneously heat both the oxygen-containing gas and the hydrocarbon feedstock.
[0046]
【The invention's effect】
Claim 1 and dependent claims 2, 3 In the fullerene production method described above, the hydrocarbon raw material is preheated to a temperature range higher than its vaporization temperature and lower than the auto-ignition temperature in the presence of oxygen, so that the hydrocarbon raw material condenses in the gas passage and the reactor. In addition, since no ignition occurs due to the reaction of oxygen, the hydrocarbon raw material can be stably supplied to the reaction furnace.
And the reaction temperature (namely, combustion temperature) of the hydrocarbon raw material of a reaction furnace and oxygen-containing gas becomes high only by the amount preheated, and also the manufacturing efficiency of fullerene manufacture increases.
[0047]
[0048]
[0049]
[0050]
[0051]
[0052]
[Brief description of the drawings]
FIG. 1 is a schematic explanatory diagram of a fullerene production facility to which a fullerene production method according to an embodiment of the present invention is applied.
[Explanation of symbols]
10: Fullerene production equipment, 11: Reactor, 12: Separation device, 13: Gas cooler, 14: Depressurization device, 15: Inlet, 17: Burner section, 18, 19: Pipe line, 20, 21: Heat exchanger 22: Vaporizer, 23: Premixer, 24: Discharge port, 25: Gas cooling means, 26: Pipe, 27: Heat resistant filter, 28: Backwash mechanism, 29: Tank, 30: Solenoid valve, 31: Discharge Valve, 32: Gas outlet

Claims (3)

In a method for producing fullerene by supplying a hydrocarbon raw material and an oxygen-containing gas to a reactor under reduced pressure , and incompletely combusting them in the reactor,
The hydrocarbon raw material comprising an aromatic hydrocarbon having 6 to 20 carbon atoms is vaporized by a vaporizer, and is higher by 20 ° C. than the vaporization temperature by the first heat exchanger and 50 ° C. or higher than the self-ignition temperature in the presence of oxygen. Preheat to a lower temperature range,
The oxygen-containing gas is preheated by a second heat exchanger to a temperature range higher than the vaporization temperature of the hydrocarbon raw material and lower than the self-ignition temperature by 50 ° C., and then the first and second heat exchangers are The method for producing fullerene, wherein the hydrocarbon raw material and the oxygen-containing gas that have passed through each are mixed by a premixing device and supplied to a burner portion of the reactor. 2. The fullerene production method according to claim 1, wherein the exhaust gas discharged from the outlet of the reactor is cooled by a gas temperature lowering means, and is a bag-fitter structure separation device provided with a heat-resistant filter therein, and is contained in the exhaust gas. The fullerene and carbon-based polymer component collected are recovered . 3. The fullerene production method according to claim 2 , wherein the separation device is provided with a back-cleaning mechanism using an inert gas that periodically removes the fullerene and the carbon-based polymer component adhering to the heat-resistant filter. A method for producing fullerene, comprising:

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