Fullerene production apparatus and production method

Abstract

To provide an apparatus for manufacturing fullerene capable of improving a yield of fullerene.SOLUTION: An apparatus for manufacturing fullerene is configured to generate fullerene by incomplete combustion of a raw material gas containing hydrocarbon. The apparatus for manufacturing fullerene includes: a reaction furnace having a wall part on one end side, a wall part on the other end side, and a peripheral wall part surrounding the wall part on the one end side and the wall part on the other end side; a first injection part arranged on the one end side of the reaction furnace and configured to inject the raw material gas containing hydrocarbon and a first oxygen-containing gas to the other end side to cause incomplete combustion; and a second injection part arranged on an outside of the first injection part and configured to inject a second oxygen-containing gas to the inside of the reaction furnace 2.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an apparatus and method for producing fullerenes. [Background technology]

[0002] As a method for producing fullerenes, a combustion method is known in which fullerenes are produced by incompletely combusting a raw material gas containing hydrocarbons (hereinafter also referred to as "raw material gas") in a reactor (see, for example, Patent Documents 1 and 2). This combustion method makes it possible to mass-produce fullerenes contained in soot-like matter produced by incomplete combustion of the raw material gas at low cost. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2003-160316 A [Patent Document 1] JP 2003-171106 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned conventional combustion method, the yield of fullerenes contained in the soot-like matter is not high, and therefore it is desired to increase the yield of fullerenes and further reduce the production cost of fullerenes.

[0005] The present invention has been proposed in view of the above-mentioned conventional circumstances, and has an object to provide an apparatus and method for producing fullerenes that make it possible to improve the yield of fullerenes. [Means for solving the problem]

[0006] The present invention provides the following means. (1) A fullerene production apparatus for producing fullerenes by incomplete combustion of a raw material gas containing a hydrocarbon, the fullerene production apparatus comprising: a reactor having a wall portion at one end, a wall portion at the other end, and a peripheral wall portion surrounding the wall portion at the one end and the wall portion at the other end; a first injection portion provided at one end of the reactor for injecting the raw material gas containing hydrocarbon and a first oxygen-containing gas toward the other end to cause incomplete combustion; and a second injection portion disposed outside the first injection portion for injecting a second oxygen-containing gas into the reactor 2. (2) The fullerene producing apparatus according to the preceding item (1), wherein the second injection part is disposed so as to surround the first injection part. (3) The fullerene production apparatus according to the preceding paragraph (1), wherein the second injection section injects the second oxygen-containing gas from the periphery between the one end side and the other end side. (4) The fullerene producing apparatus according to any one of (1) to (3) above, further comprising a pressure reducing mechanism for reducing the pressure inside the reactor by evacuating the inside of the reactor. (5) A method for producing fullerenes, comprising: a generation step of generating fullerenes in a reactor by incomplete combustion of a raw material gas containing a hydrocarbon; and in the generation step, a raw material gas containing a hydrocarbon and a first oxygen-containing gas are injected into the reactor from a first injection part while being incompletely combusted, and a second oxygen-containing gas is injected outside the first injection part. (6) The method for producing fullerenes according to the above (5), characterized in that the inside of the reactor is evacuated while the inside of the reactor is kept under reduced pressure. (7) The method for producing fullerenes according to (6) above, wherein the pressure inside the reaction furnace is set to 1 to 30 kPa. Effect of the Invention

[0007] As described above, according to the present invention, it is possible to improve the yield of fullerenes. [Brief description of the drawings]

[0008] [Figure 1]1 is a configuration diagram showing an example of a fullerene production apparatus according to an embodiment of the present invention. [Diagram 2] 1 is a cross-sectional view showing a configuration of a reactor equipped with a burner 9 and a second injection part 10A according to a first embodiment of the present invention. [Diagram 3] 3 is a plan view illustrating the configuration of the tip surface of the burner 9 and the second ejection part 10A shown in FIG. 2. FIG. [Figure 4] FIG. 11 is a cross-sectional view showing the configuration of a reactor including a burner 9 and a second injection part 10B according to a second embodiment of the present invention. [Diagram 5] 5 is a vertical cross-sectional view illustrating the shape and arrangement of a second ejection portion 10B and a second ejection port 22a shown in FIG. 4. FIG. [Figure 6] 5 is a cross-sectional view illustrating an example of the arrangement of second injection ports 22a of a second injection section 10B shown in FIG. 4. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, a fullerene production apparatus to which the present invention is applied will be described in detail with reference to the drawings. In addition, the drawings used in the following explanation may show characteristic parts diagrammatically for convenience in order to make the features easier to understand, and the dimensional ratios of each component may not necessarily be the same as the actual ones.

[0010] (First embodiment) First, a fullerene production apparatus according to a first embodiment of the present invention will be described with reference to FIGS. Fig. 1 is a configuration diagram showing an example of a fullerene production apparatus 1 of the present embodiment. Fig. 2 is a cross-sectional view showing an example of a reactor 2 included in the fullerene production apparatus 1 of the present embodiment.

[0011] As shown in FIG. 1, the fullerene production apparatus 1 of this embodiment includes a reactor 2 that produces a soot-like material containing fullerenes by incomplete combustion of a raw material gas containing hydrocarbons, a recovery mechanism 3 that recovers the soot-like material produced in the reactor 2, a cooling mechanism 4 that cools the gas that has passed through the recovery mechanism 3, and a pressure reduction mechanism 5 that creates a reduced pressure state inside the reactor 2 while sucking in the gas cooled by the cooling mechanism 4.

[0012] In addition, this fullerene production apparatus 1 has a first pipe 6 connecting the reactor 2 and the recovery mechanism 3, a second pipe 7 connecting the recovery mechanism 3 and the cooling mechanism 4, and a third pipe 8 connecting the cooling mechanism 4 and the pressure reduction mechanism 5.

[0013] The reactor 2 is cylindrical, has a wall 2b at one end (upper side), a wall 2c at the other end (lower side), and a peripheral wall 2a surrounding the wall 2b at one end and the wall 2c at the other end, and is disposed in a vertically upright state. The wall 2c at the other end is provided with an exhaust port 2d (hereinafter also referred to as "exhaust gas exhaust port 2d") for discharging exhaust gas.

[0014] The reactor 2 may be made of heat-resistant materials such as zirconia (ZrO2), tungsten (W), tantalum (Ta), platinum (Pt), titanium (Ti), titanium nitride (TiN), alumina (Al2O3), silicon carbide (SiC), etc. At least a portion of the outside and inside of the reactor 2 may be lined with a heat insulating material such as alumina firebricks or alumina moldable firebricks.

[0015] Regarding the arrangement of the reactor 2, it is preferable to arrange it in the vertical direction as described above, since the influence of the soot-like matter retention is small. When the arrangement direction of the reactor 2 is vertical, it is preferable to supply the raw material gas from above. On the other hand, the reactor 2 can also be arranged, for example, in the horizontal direction or inclined at an angle.

[0016] Furthermore, the reactor 2 is equipped with a burner 9 and a second injection part 10A shown in Fig. 2. Figs. 3(A) and (B) are plan views illustrating examples of the configurations of the tip surfaces of the first injection part 23c of the burner 9 and the second injection part 10A.

[0017] The burner 9 has a cylindrical burner holder 23 with a top that is attached in a state of penetrating the wall portion 2b on one end side of the reaction furnace 2, and a premixing chamber 23a, a pressure accumulation chamber 23b, and a first injection portion 23c that are provided in this order from the top inside the burner holder 23. In addition, a pipe 24a for introducing a raw material gas and a pipe 24b for introducing a first oxygen-containing gas are connected to the top of the burner holder 23.

[0018] The premixing chamber 23a mixes the raw material gas introduced from the pipe 24a with the first oxygen-containing gas introduced from the pipe 24b at a predetermined ratio. The pressure accumulation chamber 23b accumulates the raw material gas and the first oxygen-containing gas (hereinafter also referred to as "mixed gas") mixed in the premixing chamber 23a at a predetermined pressure. The first injection part 23c has a plurality of first injection ports 21a at its tip surface, and injects the mixed gas accumulated in the pressure accumulation chamber 23b downward (toward the exhaust gas discharge port 2d) from the first injection ports 21a. The first injection part 23c may be composed of a porous ceramic sintered body or a sintered body of metal powder.

[0019] In the present embodiment, the premixing chamber 23a, the pressure accumulation chamber 23b, and the first injection portion 23c are provided inside the burner holder 23, but the premixing chamber 23a may be omitted. Furthermore, the premixing chamber 23a and the pressure accumulation chamber 23b may be provided outside the burner holder 23 as necessary.

[0020] The second injection part 10A is, for example, a cylinder having a certain thickness, and is disposed on the side of the wall part 2b at one end side in the reactor 2, outside the first injection part 23c, and is connected to a pipe 25 that supplies a second oxygen-containing gas. Here, being disposed outside the first injection part 23c means that the second injection part 10A is disposed at a position where the shortest horizontal linear distance between the inner peripheral surface of the cylinder of the second injection part 10A and the inner peripheral surface of the peripheral wall part 2a is closer than the shortest horizontal linear distance between the outer peripheral side of the first injection part 23c and the inner peripheral surface of the peripheral wall part 2a. More specifically, as shown in FIG. 2, the second injection part 10A is disposed so as to surround the periphery of the first injection part 23c. That is, the shortest horizontal linear distance between the inner peripheral surface of the cylinder of the second injection part 10A and the inner peripheral surface of the peripheral wall part 2a is closer than the shortest horizontal linear distance between the outer periphery of the first injection part 23c and the inner peripheral surface of the peripheral wall part 2a, so the second injection part 10A is disposed outside the first injection part 23c. Also, it is preferable that the shortest horizontal linear distance between the inner peripheral surface of the cylinder of the second injection part 10A and the inner peripheral surface of the peripheral wall part 2a is shorter.

[0021] The second injection part 10A is provided with a second injection port 22a for injecting a second oxygen-containing gas at the tip surface of the cylinder. In addition, a passage connecting the second injection port 22a and a pipe 25 is provided inside the second injection part 10A.

[0022] The shape and number of the second injection ports 22a are not particularly limited, but as an example, they are circular as shown in Fig. 3(A) In Fig. 3(A), the tip surface of the second injection part 10A is in the shape of a link, and the multiple second injection ports 22a are evenly arranged on the tip surface of the second injection part 10A.

[0023] Furthermore, as shown in FIG. 3(B), a ring-shaped second injection port 22a may be disposed on the tip surface of the ring-shaped second injection part 10A.

[0024] In addition, the tip surface of the first ejection portion 23c and the tip surface of the second ejection portion 10A may have the same height position in the vertical direction or may have different height positions, but it is preferable that they have the same height positions.

[0025] The piping 25 supplies the second oxygen-containing gas to the second injection part 10A while penetrating the upper part of the peripheral wall part 2a of the reactor 2. The piping 25 may also supply the second oxygen-containing gas to the second injection part 10A by penetrating the wall part 2b on one end side of the reactor 2. The second injection part 10A injects the second oxygen-containing gas supplied via the piping 25 downward from the second injection port 22a.

[0026] Further, an ignition mechanism 30 for igniting the raw material gas is provided in the vicinity of the position where the first pipe 6 of the reactor 2 is connected.

[0027] The raw material gas and the first oxygen-containing gas injected into the reactor 2 from the first injection section 23c are incompletely combusted to generate exhaust gas containing soot-like matter containing fullerenes, carbon monoxide, carbon dioxide, water vapor, and unreacted raw material gas.

[0028] In addition, by injecting a second oxygen-containing gas into the reactor 2 from the second injection part 10A arranged outside the first injection part 23c, an oxygen-rich zone is formed outside the first injection part 23c.

[0029] The first pipe 6 is connected to the exhaust gas outlet 2d. The exhaust gas generated by incomplete combustion of the raw material gas passes through the first pipe 6 and reaches the recovery mechanism 3.

[0030] The recovery mechanism 3 has a collector 12 housing a filter 11, a tank 14 connected to the upper end (one end) of the collector 12 via an solenoid valve 13, and a discharge valve 15 provided on the lower end (other end) of the collector 12.

[0031] The first pipe 6 is connected to the side of the upper portion of the collector 12. The second pipe 7 is connected to the upper portion of the collector 12. For example, a sintered metal filter is used as the filter 11. The solenoid valve 13 is branched off and connected to the second pipe 7. The tank 14 stores a high-pressure inert gas such as nitrogen gas (N2) or argon gas (Ar).

[0032] In the recovery mechanism 3, the soot-like matter contained in the exhaust gas supplied from the first pipe 6 is collected by the filter 11, and then the solenoid valve 13 is periodically opened to inject an inert gas from the tank 14 toward the collector 12. This causes the soot-like matter adhering to the filter 11 to fall off. Thereafter, the discharge valve 15 is opened to enable the soot-like matter accumulated in the collector 12 to be recovered.

[0033] The cooling mechanism 4 has a structure identical to or similar to that of a normal heat exchanger, and one end (upper end) thereof is connected to the second piping 7 and the other end (lower end) thereof is connected to the third piping 8.

[0034] The cooling mechanism 4 cools the gas that has passed through the recovery mechanism 3. The cooling mechanism 4 also liquefies unreacted hydrocarbons and water vapor in the gas, and is capable of discharging the liquefied gas from a drain 16 provided on the lower side.

[0035] In addition to the cooling mechanism 4, the first piping 6 may be configured to be cooled since the exhaust gas passing through the first piping 6 is at a high temperature.

[0036] The decompression mechanism 5 is composed of a vacuum pump, and sucks the gas cooled by the cooling mechanism 4 through the third pipe 8. This makes it possible to discharge the soot-like matter generated in the reaction furnace 2 to the recovery mechanism 3 side through the first pipe 6 while generating a negative pressure between the reaction furnace 2 and the gas.

[0037] Examples of the hydrocarbons contained in the raw material gas include aromatic hydrocarbons having 6 to 15 carbon atoms, such as toluene, benzene, xylene, naphthalene, methylnaphthalene, anthracene, and phenanthrene; coal-based hydrocarbons, such as creosote oil and carboxylic acid oil; acetylene-based unsaturated hydrocarbons; ethylene-based hydrocarbons; and aliphatic saturated hydrocarbons, such as pentane and hexane. Two or more of these hydrocarbons may be mixed and used. Among the above-mentioned hydrocarbons, the raw material gas preferably contains aromatic hydrocarbons. The raw material gas may be diluted with an inert gas, such as nitrogen or argon, as necessary.

[0038] The first oxygen-containing gas is a gas containing oxygen gas, and examples of the gas include oxygen and air. The first oxygen-containing gas may be supplied to the reactor 2 separately from the raw material gas, or may be mixed with the raw material gas in advance and then supplied to the reactor 2.

[0039] The second oxygen-containing gas is oxygen gas, air, or a mixed gas of oxygen gas and an inert gas. Examples of the inert gas include nitrogen, argon, helium, neon, and carbon dioxide. The second oxygen-containing gas may be heated.

[0040] The ratio of the raw material gas and the first oxygen-containing gas injected into the reaction furnace 2, that is, the ratio (C / O) of the number of carbon atoms (C) in the raw material gas to the number of oxygen atoms (O) in the first oxygen-containing gas, is preferably 0.8 to 2.0, and more preferably 1.0 to 1.5.

[0041] Furthermore, the ratio of the raw material gas injected into the reaction furnace 2 to the second oxygen-containing gas injected into the reaction furnace 2, that is, the ratio (C / O) of the number of carbon atoms (C) in the raw material gas to the number of oxygen atoms (O) in the second oxygen-containing gas, is preferably 14.0 to 52.0, and more preferably 20.0 to 30.0.

[0042] The fullerenes produced are, for example, C 60 Fullerene (C 60 ), C 70 Fullerene (C 70 ), C 76 , C 78 , C 84 , C 90 , C 96 and the like.

[0043] In the fullerene production apparatus 1 of the present embodiment having such a configuration, most of the unreacted raw material gas in the exhaust gas and the generated soot-like matter are discharged from the exhaust gas outlet 2d to the outside of the reactor 2 without reacting with the second oxygen-containing gas, but a small amount of the soot-like matter and the unreacted raw material gas diffuse toward the outside of the first injection part 23c, enter the oxygen-rich zone, react with the second oxygen-containing gas, and release heat. This makes it possible to increase the temperature outside the first injection part 23c, and thus reduce the temperature distribution in the reactor 2, thereby improving the yield of fullerenes.

[0044] Second Embodiment Next, a description will be given of a fullerene production apparatus 1 according to a second embodiment of the present invention. The fullerene production apparatus 1 according to the second embodiment of the present invention has a reaction furnace 2 shown in FIG.

[0045] FIG. 4 is a cross-sectional view showing the configuration of the reactor 2 equipped with the burner 9 and the second injection unit 10B. The reactor 2 is arranged in the vertical direction. FIG. 5 is a longitudinal cross-sectional view illustrating the shape and arrangement of the second injection unit 10B and the second injection port 22a equipped in the second injection unit 10B. FIG. 6 is a transverse cross-sectional view illustrating the arrangement of the second injection port 22a of the second injection unit 10B. In the following description, the same parts as those in the fullerene manufacturing apparatus 1 of the first embodiment will not be described and will be given the same reference numerals in the drawings. In addition, the raw material gas, the first oxygen-containing gas, and the second oxygen-containing gas are also the same as those in the first embodiment, so their description will be omitted.

[0046] The second injection part 10B is disposed outside the first injection part 23c and has a cylindrical shape extending downward from a position surrounding the periphery of the burner holder 23. Here, being disposed outside the first injection part 23c means that the second injection part 10B is disposed at a position where the shortest horizontal linear distance between the inner peripheral surface of the second injection part 10B and the inner peripheral surface of the peripheral wall part 2a is closer than the shortest horizontal linear distance between the outer peripheral side of the first injection part 23c and the inner peripheral surface of the peripheral wall part 2a. More specifically, as shown in FIG. 4, the second injection part 10B has a cylinder extending downward from a position surrounding the periphery of the burner holder 23. That is, the shortest horizontal linear distance between the inner peripheral surface of the cylinder of the second injection part 10B and the inner peripheral surface of the peripheral wall part 2a is shorter than the shortest horizontal linear distance between the outer periphery of the first injection part 23c and the inner peripheral surface of the peripheral wall part 2a, so the second injection part 10B is disposed outside the first injection part 23c. Also, the shorter the shortest horizontal linear distance between the inner peripheral surface of the second injection part 10B and the inner peripheral surface of the peripheral wall part 2a, the better.

[0047] A plurality of second injection ports 22a are arranged in a row on the inner peripheral surface of the second injection part 10B. A passage connecting the pipe 25 and the second injection port 22a is provided inside the second injection part 10B. This allows the second injection part 10B to inject the second oxygen-containing gas into the reactor 2 from the second injection port 22a.

[0048] The second injection ports 22a in the inner peripheral surface of the second injection part 10B may have shapes and arrangements as shown in Fig. 5(A), (B), and (C) in the axial direction of the second injection part 10B. For example, the multiple second injection ports 22a shown in Fig. 5(A) are each opened in a slit shape in the axial direction of the second injection part 10B, and are arranged side by side in the circumferential direction of the second injection part 10B.

[0049] On the other hand, the multiple second injection ports 22a shown in FIG. 5(B) are each opened in a circular shape, and are arranged side by side in the circumferential and axial directions of the second injection part 10B.

[0050] On the other hand, the multiple second injection ports 22a shown in FIG. 5(C) are each opened in the form of a slit in the circumferential direction of the second injection part 10B, and are arranged side by side in the axial direction of the second injection part 10B.

[0051] In addition, when the second injection part 10B has a plurality of second injection ports 22a in the circumferential direction as shown in Fig. 5(A) and (B), the plurality of second injection ports 22a may be formed as shown in Fig. 6. For example, the plurality of second injection ports 22a shown in Fig. 6(A) are formed by protrusions 33 that open obliquely in the same direction on the inner circumferential surface of the second injection part 10B. This makes it possible to form a vortex flow of the second oxygen-containing gas injected from each of the second injection ports 22a.

[0052] 6(B) are open toward the center of the reactor 2 in the circumferential direction of the second injection part 10B. This allows the second oxygen-containing gas injected from each of the second injection ports 22a to be injected toward the center of the reactor 2.

[0053] By injecting a second oxygen-containing gas into the reactor 2 from the second injection part 10B disposed outside the first injection part 23c, an oxygen-rich zone is formed outside the first injection part 23c.

[0054] In the fullerene production apparatus 1 of the present embodiment having such a configuration, most of the unreacted raw material gas in the exhaust gas and the generated soot-like matter are discharged from the exhaust gas outlet 2d to the outside of the reactor 2 without reacting with the second oxygen-containing gas, but a small amount of the soot-like matter and the unreacted raw material gas diffuse toward the outside of the first injection part 23c, enter the oxygen-rich zone, react with the second oxygen-containing gas, and release heat. This makes it possible to increase the temperature outside the first injection part 23c, and thus reduce the temperature distribution in the reactor 2, thereby improving the yield of fullerenes.

[0055] (Production method of fullerene) Next, a method for producing fullerenes using the above-mentioned fullerene production apparatus 1 will be described. The method for producing fullerenes of this embodiment is characterized by a production process in which fullerenes are produced in a reactor by incomplete combustion of a raw material gas containing a hydrocarbon, and in the production process, a raw material gas containing a hydrocarbon and a first oxygen-containing gas are injected into the reactor from a first injection part while being incompletely combusted, and a second oxygen-containing gas is injected outside the first injection part.

[0056] In the fullerene production method of the present embodiment, the soot-like material produced by incomplete combustion and the unreacted raw material gas react with the second oxygen-containing gas present outside the first injection part, and release heat. This makes it possible to improve the temperature outside the first injection part, and in turn to reduce the temperature distribution in the reactor 2, thereby improving the yield of fullerene.

[0057] The pressure inside the reactor 2 is preferably 1 to 30 kPa, and more preferably 1 to 10 kPa. If the pressure inside the reactor 2 is within this range, it is possible to prevent overload of the pressure reducing mechanism 5 and backfire of the flame.

[0058] The present invention is not necessarily limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention. EXAMPLES

[0059] The effects of the present invention will be made clearer by the following examples. Note that the present invention is not limited to the following examples, and can be appropriately modified and implemented without departing from the gist of the present invention.

[0060] [Calculation of fullerene yield] In Examples 1 to 3 and Comparative Example 1, C 60 and C 70 The total yield of fullerene was calculated as the yield of fullerene. In addition, in accordance with "JIS Z 8981", the C contained in the collected soot-like matter was60 and C 70 The content was measured as follows.

[0061] Specifically, 15 g of 1,2,3,5-tetramethylbenzene (TMB) was added to 0.05 g of the collected soot-like material, and then ultrasonic treatment was performed for 15 minutes to obtain a suspension. The obtained suspension was filtered through a membrane filter with a pore size of 0.5 μm, and the filtrate (sample liquid) was analyzed by high performance liquid chromatography (HPLC) to obtain the following: 60 and C 70 The amount of C contained in the soot was determined. 60 and C 70 The content [mass %] was calculated.

[0062] Here, the C contained in the soot 60 and C 70 When calculating the content of C, several known concentrations of C 60 and C 70 A calibration curve was prepared using a TMB solution.

[0063] The HPLC measurement conditions are as follows. Equipment: Infinity1260 (Agilent) Sample injection volume: 5μL Eluent: toluene (47% by volume) / methanol (53% by volume) mixed solvent Eluent flow rate: 1 ml / min Column: YMC-Pack ODS-AM 100*4.6mmID S-3μm,12nm Measurement temperature: 40℃ Detector: UV 325nm (JIS)

[0064] Next, the fullerene content (C 60 and C 70 From the total content of the soot, the fullerene yield [mass %] was calculated by the formula {(amount of soot recovered [g]) / (amount of raw material gas consumed [g])}×(fullerene content [mass %]).

[0065] Example 1 Fullerenes were produced using a fullerene production apparatus 1 having a reactor 2 shown in Fig. 2. The tip of the second ejection part 10A has a structure shown in Fig. 3(A).

[0066] Here, the reactor 2 is an alumina cylinder arranged vertically, with a height of 1000 mm and an inner diameter of 200 mm. A burner 9 is provided so as to penetrate the wall 2b of the reactor 2. The first injection part 23c is made of a disk-shaped porous ceramic sintered body with a diameter of 100 mm, and this ceramic sintered body has holes (first injection ports 21a) with a diameter of about 0.5 mm to 1.0 mm, which are formed over a distance of 1 cm. 2 There are 60 to 80 of them formed around each area.

[0067] The second ejection part 10A is made of zirconia, is a cylinder with an inner diameter of 170 mm, and is 10 mm thick. Forty second ejection ports 22a, each having a diameter of 5 mm, are evenly arranged on the tip surface of the second ejection part 10A. In the vertical direction, the tip surface of the second ejection part 10A has the same height position as the tip surface of the first ejection part 23c.

[0068] Toluene was used as the raw material gas, and pure oxygen gas (purity 99.9% by volume) was used as the first oxygen-containing gas. Here, the toluene was once heated in a vaporizer installed in the pipe 24a to become gaseous, and then supplied to the burner 9. The first oxygen-containing gas was supplied to the burner 9 via the pipe 24b. The flow rate of the toluene gas was set to 20 g / min, and the flow rate of the pure oxygen was set to 13 NL / min.

[0069] The second oxygen-containing gas was pure oxygen gas (purity 99.9% by volume), and the flow rate of the pure oxygen gas was set to 0.65 NL / min.

[0070] When producing fullerenes, the pressure inside the reaction furnace 2 was set to 5.33 kPa.

[0071] Under the above conditions, the fullerene production apparatus 1 was operated for 3 hours, and the generated soot-like material was collected from the collection mechanism 3. The fullerene content in the soot-like material was measured by the method described in [Calculation of fullerene yield], and the fullerene yield was calculated. As a result, the fullerene yield was 1.3%.

[0072] Example 2 Fullerenes were produced in the same manner as in Example 1, except that the flow rate of pure oxygen gas as the second oxygen-containing gas was set to 0.4 NL / min.

[0073] Under the above conditions, the fullerene production apparatus 1 was operated for 3 hours, and the soot-like material produced was recovered from the recovery mechanism 3 in the same manner as in Example 1, and the fullerene yield was calculated. As a result, the fullerene yield was 0.9%.

[0074] Example 3 Fullerenes were produced using a fullerene production apparatus 1 having a reactor 2 shown in FIG.

[0075] The second injection part 10B has a second injection port 22a shown in FIG. 5(B). The second injection port 22a is open as shown in FIG. 6(A). The second injection part 10B is a cylinder made of zirconia, and the cylinder has an inner diameter of 170 mm, a thickness of 10 mm, and a height of a part below the tip surface of the first injection part 23c of 300 mm. On the inner peripheral surface below the tip surface of the first injection part 23c of the second injection part 10B, there are 20 rows of 20 second injection ports 22a with a diameter of 3 mm, which are arranged in a circumferential direction at equal distances from each other. In each row, the distances of the second injection ports 22a in the axial direction of the second injection part 10B are also equal to each other.

[0076] Except for the above, fullerenes were produced in the same manner as in Example 1.

[0077] The fullerene production apparatus 1 was operated for 3 hours, and the soot-like material produced was recovered from the recovery mechanism 3 in the same manner as in Example 1, and the fullerene yield was calculated. As a result, the fullerene yield was 1.5%.

[0078] Comparative Example 1 Fullerenes were produced in the same manner as in Example 1, except that fullerenes were produced using the fullerene production apparatus 1 not having the second injection part 10A.

[0079] The fullerene production apparatus 1 was operated for 3 hours, and the soot-like material produced was recovered from the recovery mechanism 3 in the same manner as in Example 1, and the fullerene yield was calculated. As a result, the fullerene yield was 0.6%.

[0080] From the above, it is found that the yield of fullerenes is improved in Examples 1 to 3 compared to Comparative Example 1. That is, by injecting the second oxygen-containing gas into the reactor by the second injection part disposed outside the first injection part, it is possible to improve the yield of fullerenes. [Explanation of symbols]

[0081] REFERENCE SIGNS LIST 1...Fullerene production apparatus 2...Reactor 3...Recovery mechanism 4...Cooling mechanism 5...Pressure reduction mechanism (vacuum pump) 6...First pipe 7...Second pipe 8...Third pipe 9...Burner 10A, 10B...Second injection section 11...Filter 12...Collector 13...Solenoid valve 14...Tank 15...Discharge valve 16...Drain 21a...First injection port 22a...Second injection port 23...Burner holder 23a...Premixing chamber 23b...Accumulator chamber 23c...First injection section 24a...Pipe 24b...Pipe 25...Pipe 30...Ignition mechanism

Claims

1. An apparatus for producing fullerenes by incomplete combustion of a raw material gas containing a hydrocarbon, comprising: a cylindrical reactor having an upper wall portion, a lower wall portion, and a peripheral wall portion surrounding the upper wall portion and the lower wall portion in a vertical direction; a burner holder attached to the upper wall of the reactor in a penetrating state; a first injection unit provided inside the burner holder and configured to inject the hydrocarbon-containing raw material gas and a first oxygen-containing gas toward the lower side of the reactor to cause incomplete combustion; a second injection unit that is disposed on the upper side of the reactor and outside the first injection unit so as to surround the periphery of the first injection unit, and that injects a second oxygen-containing gas into the reactor from the periphery between the upper side of the reactor and the lower side of the reactor; The fullerene production apparatus includes:

2. 2. The fullerene production apparatus according to claim 1, wherein the second injection section is a cylinder having a certain thickness, and has a second injection port at a tip surface of the cylinder for injecting the second oxygen-containing gas.

3. The fullerene production apparatus according to claim 1, characterized in that the second injection section has a cylindrical shape extending downward from a position surrounding the periphery of the burner holder, and a plurality of second injection ports are arranged in a row on the inner surface of the first injection section.

4. 4. The fullerene producing apparatus according to claim 1, further comprising a pressure reducing mechanism for reducing the pressure inside the reactor by evacuating the inside of the reactor.

5. A ratio of the hydrocarbon-containing raw material gas injected into the reactor to the first oxygen-containing gas is a ratio (C / O) of the number of carbon atoms (C) in the hydrocarbon-containing raw material gas to the number of oxygen atoms (O) in the first oxygen-containing gas, which is 0.8 to 2.0; 5. The fullerene production apparatus according to claim 1, wherein a ratio of the hydrocarbon-containing raw material gas injected into the reaction furnace to the second oxygen-containing gas is 14.0 to 52.0, expressed as a ratio (C / O) of the number of carbon atoms (C) in the hydrocarbon-containing raw material gas to the number of oxygen atoms (O) in the first oxygen-containing gas.

6. A method for producing fullerenes using the fullerene production apparatus according to any one of claims 1 to 5, comprising: a generating step of generating the fullerenes in the reactor by incomplete combustion of a raw material gas containing the hydrocarbon; In the generating step, the raw material gas containing hydrocarbons and the first oxygen-containing gas are incompletely combusted while being injected into the reactor from the first injection part, and The method for producing fullerenes, comprising injecting the second oxygen-containing gas to the outside of the first injection part.

7. The method for producing fullerenes as described in claim 6, characterized in that the inside of the reactor is placed under reduced pressure while suction is applied to the inside of the reactor.

8. The method for producing fullerenes according to claim 7, characterized in that the pressure inside the reaction furnace is set to 1 to 30 kPa.

Images