Gas pyrolysis unit and gas pyrolysis device

Abstract

A gas pyrolysis unit 2 according to the present invention comprises: a honeycomb structure 20 having one or a plurality of honeycomb structure parts 24 having an outer circumferential wall 240 and a partition wall 241 which is disposed inside the outer circumferential wall 240 and partitions and forms a plurality of cells 241a that form flow channels extending from one end surface to the other end surface; and an induction heating coil 21 that is disposed on the outer circumference of the honeycomb structure 20. At least one of the one or the plurality of honeycomb structure parts 24 comprises a conductor and / or magnetic body 25.

Description

Gas pyrolysis unit and gas pyrolysis device

[0001] The present invention relates to a gas pyrolysis unit and a gas pyrolysis apparatus for pyrolyzing gases.

[0002] As a measure against global warming, attention is being paid to H2 refining technology, which can produce carbon-free energy H2 cheaply and in large quantities without emitting CO2.

[0003] Water electrolysis is a technology for refining H2 that does not emit CO2, but its high cost remains an issue. Another alternative to water electrolysis is the thermal decomposition of hydrocarbons, particularly natural gas or methane. CO2 emissions can be reduced by recovering the carbon produced by methane thermal decomposition as a solid. However, the carbon produced as a solid can quickly cover the catalyst and become inactive, particularly when using a catalyst to promote thermal decomposition, so it is necessary to efficiently discharge it outside the reactor. One possible method for heating methane is to externally heat the reaction vessel where thermal decomposition takes place, but there were challenges in quickly reaching the decomposition temperature throughout the reaction vessel and in ensuring uniform thermal decomposition of the gas within the vessel.

[0004] Patent Document 1 listed below proposes a system for decomposing hydrocarbons such as natural gas or methane into hydrogen and carbon using a reaction vessel including a particle layer made of conductive carbon, graphite, or the like, and an electromagnetic induction unit for heating the particle layer.

[0005] European Patent Application Publication No. 4126757

[0006] The system proposed in Patent Document 1 promotes the thermal decomposition of hydrocarbons by induction heating of conductive carbon and graphite in the vessel rather than external heating, which may enable efficient heating. However, the relationship between the hydrocarbons supplied as gas into the vessel and the conductive carbon, which acts as a heating element, is not necessarily constant, making it difficult to achieve uniform heating.

[0007] The present invention has been made to solve the above-mentioned problems, and one of its objects is to provide a gas pyrolysis unit and a gas pyrolysis device that can heat gas more uniformly and improve the efficiency of gas pyrolysis.

[0008] Item 1. In one embodiment, the present invention relates to a gas pyrolysis unit for pyrolyzing gas, the gas pyrolysis unit comprising: a honeycomb structure having one or more honeycomb structure sections each having an outer peripheral wall and partition walls disposed inside the outer peripheral wall to define a plurality of cells that form flow paths extending from one end face to the other end face; and an induction heating coil disposed on the outer periphery of the honeycomb structure, wherein at least one of the one or more honeycomb structure sections includes a conductor and / or a magnetic material.

[0009] Item 2. The present invention may relate to the gas pyrolysis unit according to Item 1, wherein the conductor and / or magnetic material is present in at least a portion of the honeycomb structure in the radial and axial directions.

[0010] Item 3. The present invention may relate to the gas pyrolysis unit according to Item 2, wherein the conductive and / or magnetic material is present inside the outer peripheral wall, inside the partition wall, inside the cell, and / or on the outer peripheral wall.

[0011] Item 4. The present invention may relate to a gas pyrolysis unit according to Item 3, wherein the conductive and / or magnetic material present inside the cells is filled in the cells or coated on the surface of the partition walls.

[0012] Item 5. The present invention may relate to the gas pyrolysis unit according to any one of items 1 to 4, further comprising a magnetic shield disposed around the outer periphery of the induction heating coil.

[0013] Item 6. The present invention may relate to the gas pyrolysis unit according to any one of Items 1 to 5, wherein the honeycomb structure includes at least one selected from the group consisting of cordierite, silicon carbide, silicon, silica, and alumina.

[0014] Item 7. The present invention may relate to the gas pyrolysis unit according to any one of Items 1 to 6, wherein a glass or crystalline body containing Al and / or Si is disposed between the honeycomb structure and the induction heating coil.

[0015] Item 8. The present invention may relate to the gas pyrolysis unit according to Item 5, wherein a glass or crystal containing Al and / or Si is disposed between the induction heating coil and the magnetic shield.

[0016] Item 9. The present invention may relate to the gas pyrolysis unit according to any one of Items 1 to 8, wherein the conductor and / or magnetic material contains at least one selected from the group consisting of Fe, Cr, Ni, Mn, Zn, Co, Cu, and Si.

[0017] Item 10. The present invention may relate to the gas pyrolysis unit according to any one of Items 1 to 9, wherein the magnetic material has a Curie point of 300°C or higher.

[0018] Item 11. The present invention may relate to the gas pyrolysis unit according to any one of items 1 to 10, wherein at least one of the one or more honeycomb structure sections contains a catalyst.

[0019] Item 12. In one embodiment, the present invention relates to a gas pyrolysis device including the gas pyrolysis unit according to any one of items 1 to 11 and a power supply circuit connected to an induction heating coil, and configured so that the honeycomb structure can be induction heated by magnetic flux from the induction heating coil when gas is passed through the cells.

[0020] Item 13. The present invention may relate to the gas pyrolysis apparatus according to Item 12, wherein the gas is a gas containing hydrogen atoms, and the gas pyrolysis unit is configured to obtain hydrogen by pyrolyzing the gas.

[0021] Item 14. The present invention may relate to a gas pyrolysis apparatus according to Item 13, wherein the gas contains one or more of hydrocarbons including naphtha, hydroxides, ammonia, oxynitrides, and hydrogen sulfide, and / or biogas.

[0022] According to one embodiment of the gas pyrolysis unit and gas pyrolysis device of the present invention, at least one of one or more honeycomb structure parts contains a conductor and / or a magnetic material, so that the relationship between the conductor and / or magnetic material as a heating element and the gas can be more reliably managed, the gas can be heated more uniformly, and the gas pyrolysis efficiency can be improved.

[0023] 8 is an explanatory diagram showing a gas pyrolysis apparatus 1 according to a first embodiment of the present invention. FIG. 9 is a perspective view showing the gas pyrolysis unit 2 of FIG. 1. FIG. 1 is a circuit diagram showing the power supply circuit 3 of FIG. 1. FIG. 1 is a front view showing the honeycomb structure 20 of FIG. 2 and its periphery. FIG. 10 is an explanatory diagram showing a first example of an existence mode of the conductor and / or magnetic material 25 in the honeycomb structure 20 of FIG. 2. FIG. 11 is an explanatory diagram showing a second example of an existence mode of the conductor and / or magnetic material 25 in the honeycomb structure 20 of FIG. 2. FIG. 12 is an explanatory diagram showing a third example of an existence mode of the conductor and / or magnetic material 25 in the honeycomb structure 20 of FIG. 2. FIG. 13 is an explanatory diagram showing a modified example of the gas pyrolysis apparatus 1 of FIG. 1. FIG. 14 is an explanatory diagram showing an example of an existence mode of the conductor and / or magnetic material 25 in the honeycomb structure 20 of FIG. 8. FIG. 15 is an explanatory diagram showing another example of an existence mode of the conductor and / or magnetic material 25 in the honeycomb structure 20 of FIG. 8. FIG. 16 is an explanatory diagram showing a gas pyrolysis apparatus 1 according to a second embodiment of the present invention.

[0024] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to each embodiment, and the components can be modified and embodied without departing from the spirit of the present invention. Furthermore, various inventions can be formed by appropriately combining multiple components disclosed in each embodiment. For example, some components may be omitted from all the components shown in the embodiments. Furthermore, components of different embodiments may be appropriately combined.

[0025] Embodiment 1. Fig. 1 is an explanatory diagram showing a gas pyrolysis apparatus 1 according to embodiment 1 of the present invention, Fig. 2 is a perspective view showing the gas pyrolysis unit 2 of Fig. 1, Fig. 3 is a circuit diagram showing the power supply circuit 3 of Fig. 1, and Fig. 4 is a front view showing the honeycomb structure 20 of Fig. 2 and its periphery. Also, Fig. 5 is an explanatory diagram showing a first example of an arrangement of conductors and / or magnetic materials 25 in the honeycomb structure 20 of Fig. 2, Fig. 6 is an explanatory diagram showing a second example of an arrangement of conductors and / or magnetic materials 25 in the honeycomb structure 20 of Fig. 2, and Fig. 7 is an explanatory diagram showing a third example of an arrangement of conductors and / or magnetic materials 25 in the honeycomb structure 20 of Fig. 2.

[0026] The gas pyrolysis apparatus 1 and gas pyrolysis unit 2 shown in Figures 1 and 2 are an apparatus and a unit for thermally decomposing a gas 10. The gas 10 contains hydrogen atoms, and the gas pyrolysis apparatus 1 is configured to obtain hydrogen by thermally decomposing the gas 10 using the gas pyrolysis unit 2. The hydrogen obtained in the gas pyrolysis apparatus 1 is discharged from the gas pyrolysis apparatus 1 and recovered in a recovery apparatus 4. The recovery apparatus 4 may be, for example, a hydrogen recovery system provided with a purification mechanism as needed.

[0027] A hydrogen-containing gas is a gas whose component chemical formula contains hydrogen (H). Such gases may include one or more of hydrocarbons, hydroxides, ammonia, oxynitrides, hydrogen sulfide, and / or biogas. An example of a hydrocarbon is naphtha. FIG. 1 shows an example gas pyrolysis system 1 in which methane (CH4) is introduced as gas 10 and thermally decomposed into hydrogen and carbon 11 (CH4 → C (solid) + 2H2). A hydrogen and methane mixed gas 12 is recovered in recovery system 4. High-purity hydrogen can be produced or recovered in recovery system 4 using a pressure swing adsorption (PSA) hydrogen separation membrane or the like.

[0028] As shown in FIG. 1, the gas pyrolysis device 1 includes a gas pyrolysis unit 2, a power supply circuit 3, a first chamber 5, and a second chamber 6.

[0029] The gas pyrolysis unit 2 is for pyrolyzing the gas as described above, and includes a honeycomb structure 20 and an induction heating coil 21.

[0030] The honeycomb structure 20 has one or more honeycomb structure portions 24. FIG. 2 shows a honeycomb structure 20 having multiple honeycomb structure portions 24. As particularly shown in FIG. 2, the honeycomb structure portion 24 has an outer peripheral wall 240 and partition walls 241 disposed inside the outer peripheral wall 240. The partition walls 241 define multiple cells 241a that form flow paths extending from one end face to the other end face. The honeycomb structure portion 24 may have a columnar outer shape. A columnar shape can be understood as a three-dimensional shape having a predetermined thickness in the axial direction AD. The axial direction AD may be the extension direction of the cells 241a. The ratio (aspect ratio) of the axial length of the honeycomb structure portion 24 to the diameter or width of the end face of the honeycomb structure portion 24 is arbitrary. The columnar shape may include a shape (flat shape) in which the axial length of the honeycomb structure portion 24 is shorter than the diameter or width of the end face. The external shape of the honeycomb structure portion 24 is not particularly limited, but may be a columnar shape with square end faces (quadratic column shape) as shown in FIG. 2, a columnar shape with circular or oval end faces, or a columnar shape with polygonal end faces having fewer or more corners (triangular, pentagonal, hexagonal, heptagonal, octagonal, etc.).

[0031] The material of the honeycomb structure 24 (the outer peripheral wall 240 and the partition walls 241) is not particularly limited, but is typically formed of a ceramic material. The honeycomb structure 24 preferably contains at least one selected from the group consisting of cordierite, silicon carbide, silicon, silica, and alumina. More specifically, the honeycomb structure 24 may be formed of cordierite, silicon carbide, aluminum titanate, silicon nitride, mullite, alumina, silica, a silicon-silicon carbide composite material, or a silicon carbide-cordierite composite material. More preferably, the honeycomb structure 24 is formed of cordierite, alumina, silica, silicon carbide, or a silicon-silicon carbide composite material. In this specification, silicon carbide-based and cordierite-based mean that the outer peripheral wall 240 and the partition walls 241 contain silicon carbide or cordierite in an amount of 50 mass% or more of the entire outer peripheral wall 240 and the partition walls 241.

[0032] The shape of the cells 241a is not particularly limited, but is preferably a polygon such as a triangle, a rectangle, a pentagon, a hexagon, or an octagon, a circle, or an ellipse in a cross section perpendicular to the central axis of the honeycomb structure 20, or may be other irregular shapes. A polygon is preferable.

[0033] The thickness of the partition walls 241 is preferably 0.05 to 0.50 mm, and more preferably 0.07 to 0.38 mm from the viewpoint of ease of manufacture. For example, if the thickness is 0.05 mm or more, the strength of the honeycomb structure 20 is further improved, and if the thickness is 0.50 mm or less, pressure loss can be reduced. Note that the thickness of the partition walls 241 is an average value measured by observing a cross section in the central axis direction with a microscope.

[0034] The porosity of the partition walls 241 is preferably 20 to 70%. In terms of ease of manufacture, the porosity of the partition walls 241 is preferably 20% or more, and if it is 70% or less, the strength of the honeycomb structure 20 can be maintained.

[0035] The average pore diameter of the partition walls 241 is preferably 2 to 30 μm, and more preferably 5 to 25 μm. When the average pore diameter of the partition walls 241 is 2 μm or more, manufacturing becomes easy, and when it is 30 μm or less, the strength of the honeycomb structure 20 can be maintained. In this specification, the terms "average pore diameter" and "porosity" refer to the average pore diameter and porosity measured by mercury intrusion porosimetry.

[0036] The density of the cells 241a is not particularly limited, but is preferably 5 to 150 cells / cm 2 The range is preferably 16 to 100 cells / cm 2 More preferably, the range is 31 to 100 cells / cm 2 It is more preferable that the range is:

[0037] Such a honeycomb structure portion 24 is produced by forming a honeycomb formed body by molding a clay containing ceramic raw materials into a honeycomb shape having partition walls 241 that define a plurality of cells 241a that extend from one end face to the other and serve as fluid flow paths, and then drying and firing the honeycomb formed body. The peripheral wall 240 may be a peripheral wall 240 extruded integrally with the honeycomb formed body. Alternatively, after molding or firing the honeycomb formed body, the periphery of the honeycomb formed body or sintered honeycomb body may be ground to a predetermined shape, and a coating material may be applied to the ground honeycomb formed body or sintered honeycomb body to form a peripheral coating (in this case, only the peripheral coating constitutes the peripheral wall 240). Alternatively, the peripheral wall 240 extruded integrally with the honeycomb formed body may be formed with a peripheral coating without being ground (the peripheral wall 240 has a two-layer structure consisting of the peripheral wall of the honeycomb sintered body or the like and the peripheral coating).

[0038] The honeycomb structure 20 is not limited to an integrated honeycomb structure 20 in which the partition walls 241 are integrally formed, but may be, for example, a honeycomb structure 20 (bonded honeycomb structure) having a structure in which a plurality of columnar honeycomb segments, each having ceramic partition walls 241 and a plurality of cells 241a that serve as fluid flow paths, are combined together via a bonding material layer.

[0039] At least one of the one or more honeycomb structure portions 24 of this embodiment includes a conductor and / or a magnetic material 25. The gas pyrolysis apparatus 1 of this embodiment is configured so that the honeycomb structure 20 can be induction heated by the magnetic flux from the induction heating coil 21 when gas is passed through the cell 241a.

[0040] Here, to efficiently pyrolyze the gas, it is preferable to heat the gas uniformly. Simply placing a heating element in the tank, as in Patent Document 1, can make it difficult to achieve uniform heating because the relationship between the gas and the heating element in the tank is not necessarily constant. However, by incorporating a conductor and / or magnetic material 25 into the honeycomb structure 24, which is a structure having a predetermined shape, the relationship between the gas and the conductor and / or magnetic material 25 inside the honeycomb structure 24 can be more reliably controlled, allowing the gas to be heated more uniformly and improving the efficiency of pyrolysis of the gas.

[0041] Furthermore, by including the conductor and / or magnetic material 25 in the honeycomb structure portion 24, the effective area for pyrolysis per volume can be increased. Also, gas flow paths (cells 241a) can be secured in the honeycomb structure 20, which allows efficient pyrolysis of gas and improves the recovery efficiency of pyrolyzed gas.

[0042] As will be explained later with reference to the drawings, the conductor and / or magnetic material 25 may be present in at least a part of the radial direction and the axial direction AD within the honeycomb structure 20. Furthermore, the conductor and / or magnetic material 25 may be present inside the outer peripheral wall 240, inside the partition wall 241, inside the cell 241a, and / or on the outer peripheral wall 240. The conductor and / or magnetic material 25 present inside the cell 241a may be filled in the cell 241a or coated on the surface of the partition wall 241.

[0043] 5 shows an embodiment in which the conductor and / or magnetic material 25 is filled into some of the cells 241a. The conductor and / or magnetic material 25 may have a columnar outer shape that matches the shape of the cells 241a. The conductor and / or magnetic material 25 may have such an outer shape before being filled into the cells 241a, or may have such an outer shape after being filled into the cells 241a. In other words, the conductor and / or magnetic material 25 may constitute a shaped material having a predetermined shape, or may constitute a paste-like amorphous material.

[0044] The shaped material and the unshaped material may be composed of a composite composition of a conductor and / or magnetic material 25 and a binder or adhesive material. Examples of binders include materials primarily composed of metal or glass. Examples of adhesive materials include materials primarily composed of silica or alumina. In addition to the binder or adhesive material, an organic or inorganic substance may also be contained. The conductor and / or magnetic material 25 may be filled all the way from one end face to the other end face of the honeycomb structure 20. Alternatively, the conductor and / or magnetic material 25 may be filled from one end face of the honeycomb structure 20 to partway through the cells 241a.

[0045] The conductor and / or magnetic material 25 is induction-heated by the magnetic flux from the induction heating coil 21, and the heat heats the honeycomb structure portion 24. By filling some of the cells 241a with the conductor and / or magnetic material 25, it becomes possible for the cells 241a to function as heaters in the honeycomb structure 20.

[0046] 6 shows an embodiment in which the conductive and / or magnetic material 25 is coated on the surface of the partition wall 241. In the illustrated embodiment, the conductive and / or magnetic material 25 is coated on the surface of the partition wall 241 of all the cells 241 a, but the conductive and / or magnetic material 25 may be coated on the surface of only the partition wall 241 of some of the cells 241 a.

[0047] The conductor and / or magnetic material 25 coated on the surface of the partition wall 241 can form a coating layer together with an adhesive material in which the conductor and / or magnetic material 25 are dispersed. Examples of the adhesive material that can be used include glass containing silicic acid, boric acid, or borosilicate, crystallized glass, ceramics, and glass containing other oxides, crystallized glass, ceramics, and the like. The conductor and / or magnetic material 25 may extend from one end face to the other end face of the honeycomb structure portion 24, or may extend over a portion of the honeycomb structure portion 24 in the axial direction AD. The amount of the conductor and / or magnetic material 25 contained in the coating layer may vary in the radial direction and the axial direction AD within the honeycomb structure 20.

[0048] The conductor and / or magnetic material 25 is induction-heated by the magnetic flux from the induction heating coil 21, and the generated heat heats the honeycomb structure portion 24. By coating the surfaces of the partition walls 241 with the conductor and / or magnetic material 25, it becomes possible for the cells 241a to function as heaters in the honeycomb structure 20, similar to the case where the conductor and / or magnetic material 25 is filled in the cells 241a. On the other hand, the gas 10 can also pass through the cells 241a in which the surfaces of the partition walls 241 are coated with the conductor and / or magnetic material 25, and in the embodiment in which the surfaces are coated with the conductor and / or magnetic material 25, the passage resistance of the gas 10 can be reduced compared to the embodiment in which the cells 241a are filled with the conductor and / or magnetic material 25.

[0049] 7 shows an embodiment in which the conductor and / or magnetic material 25 is present inside the outer peripheral wall 240 and the partition walls 241. The honeycomb structure 24 (the outer peripheral wall 240 and the partition walls 241) is usually formed of a ceramic material such as cordierite. By manufacturing the honeycomb structure 24 in a state in which the conductor and / or magnetic material 25 is mixed with or coated on the ceramic material, the conductor and / or magnetic material 25 can be present inside the outer peripheral wall 240 and the partition walls 241. By adopting such an embodiment, it becomes possible for the outer peripheral wall 240 and the partition walls 241 to function as a heater in the honeycomb structure 20. The presence modes of the conductor and / or magnetic material 25 can be combined arbitrarily.

[0050] The conductive and / or magnetic material 25 may contain at least one selected from the group consisting of Fe, Cr, Ni, Mn, Zn, Co, Cu, and Si. As the conductor and / or magnetic material 25, for example, the balance Co-20 mass% Fe, the balance Co-25 mass% Ni-4 mass% Fe, the balance Fe-15 to 35 mass% Co, the balance Fe-17 mass% Co-2 mass% Cr-1 mass% Mo, the balance Fe-49 mass% Co-2 mass% V, the balance Fe-18 mass% Co-10. Mass%Cr-2mass%Mo-1mass%Al, balance Fe-27mass%Co-1mass%Nb, balance Fe-20mass%Co-1mass%Cr-2mass%V , balance Fe-35% by mass Co-1% by mass Cr, pure cobalt, pure iron, electromagnetic soft iron, balance Fe-0.1 to 0.5% by mass Mn, balance Fe-3% by mass Si, balance Part Fe-6.5% by mass Si, remainder Fe-18% by mass Cr, remainder Fe-16% by mass Cr-8% by mass Al, remainder Ni-13% by mass Fe-5.3% by mass Mo, balance Fe-45% by mass Ni, balance Fe-10% by mass Si-5% by mass Al, balance Fe-36% by mass Ni, balance Fe-45% by mass Ni, balance Fe Metals such as -35% by mass Cr, balance Fe-13% by mass Cr-2% by mass Si, balance Fe-20% by mass Cr-2% by mass Si-2% by mass Mo, balance Fe-20% by mass Co-1% by mass V, balance Fe-13% by mass Cr-2% by mass Si, balance Fe-17% by mass Co-2% by mass Cr-1% by mass Mo. Furthermore, oxides such as Mn-Zn ferrite, Cu-Zn ferrite, Ni-Zn ferrite, and Cu-Zn-Mg ferrite can also be used as the conductor and / or magnetic material 25. Each of these conductors and / or magnetic materials 25 has a different Curie point, and is selected appropriately depending on the heating temperature required for thermal decomposition of the gas.

[0051] At least one of the one or more honeycomb structure sections 24 may contain a catalyst. Examples of catalysts include Ni, Fe, Ru, etc., for the purpose of lowering the decomposition temperature. The catalyst is provided on the wall surface of the cell 241a so as to come into contact with the gas 10. The catalyst may be provided in a cell separate from the cell 241a containing the conductor and / or magnetic material 25, or may be provided in the same cell 241a as the conductor and / or magnetic material 25. Providing the catalyst in a separate cell 241a can suppress the effects of chemical reactions between the catalyst and the conductor and / or magnetic material 25. On the other hand, providing the catalyst in the same cell 241a allows the catalyst and the conductor and / or magnetic material 25 to come into contact with each other, and direct heat transfer from the conductor and / or magnetic material 25 to the catalyst allows for more efficient heating to reach the required temperature.

[0052] The induction heating coil 21 is disposed on the outer periphery of the honeycomb structure 20. The induction heating coil 21 may be formed by winding a conductor 210 around a predetermined axis. The axis of the induction heating coil 21 may be parallel to the axial direction AD of the honeycomb structure 20. The axis may be coaxial with the central axis of the honeycomb structure 20. While FIG. 1 shows a band-shaped conductor 210 with a rectangular cross section, the conductor 210 may have any shape, such as a circular or tubular shape. The conductor 210 may be molded with an insulating material 211. Examples of the insulating material 211 that can be used include alumina, aluminum silicate, mullite, silica, and / or a heat-resistant resin. FIG. 1 shows an embodiment in which the conductor 210 molded with the insulating material 211 is fitted onto the outer surface of the outer wall 240 of the honeycomb structure 20.

[0053] The induction heating coil 21 is connected to a power supply circuit 3. As shown in FIG. 3 , the power supply circuit 3 may include a DC power supply 220, an inverter 221, a transformer 222, and a resonant capacitor 223. DC power from the DC power supply 220 is converted to AC power by the inverter 221. The transformer 222 is used when it is necessary to amplify the current flowing through the induction heating coil 21. The transformer 222 has a primary coil 222a connected to the inverter 221 and a secondary coil 222b connected to the resonant capacitor 223 and the induction heating coil 21. The turns ratio of the primary coil 222a to the secondary coil 222b is N:1. N is a number greater than 1, and the transformer 222 can amplify the AC power current. The capacitance of the resonant capacitor 223 is set to adjust the resonant frequency of the power supply circuit 3. The induction heating coil 21 is connected in series to the resonant capacitor 223 and may be connected to both ends of the secondary coil 222b together with the resonant capacitor 223. If the power source is AC, there is no need to convert it to AC, so a high-frequency converter can be used instead of an inverter. The frequency used for AC is not specified, but a frequency of 10 to 400 kHz, preferably 30 to 100 kHz, is suitably used.

[0054] When an alternating current is supplied from the power supply circuit 3 to the induction heating coil 21, a magnetic flux is generated in the vicinity of the induction heating coil 21. The honeycomb structure 20 and the conductor and / or magnetic body 25 can be induction heated by the magnetic flux from the induction heating coil 21.

[0055] By selecting the Curie point of the conductor and / or magnetic material 25, the heating temperature of the conductor and / or magnetic material 25 by induction heating can be adjusted. The conductor and / or magnetic material 25 is heated for the purpose of thermally decomposing gas. However, if the temperature rises too high, problems such as a reaction different from the intended thermal decomposition reaction may occur, the reaction rate of exothermic or endothermic reactions may become too fast, or the catalyst used to promote decomposition may deteriorate. By selecting a conductor and / or magnetic material 25 with a low Curie point, such problems can be prevented. The conductor and / or magnetic material 25 may have a Curie point of 300°C or higher. The Curie point of the conductor and / or magnetic material 25 is preferably 500°C or higher, and more preferably 700°C or higher.

[0056] The gas pyrolysis unit 2 may further include a magnetic shield 23 arranged around the induction heating coil 21. The magnetic shield 23 may be arranged to surround the induction heating coil 21. The magnetic shield 23 may be made of a magnetic material. In the illustrated embodiment, the magnetic shield 23 is a tubular member arranged around the induction heating coil 21 and having wall portions protruding radially inward at both ends. The length of the magnetic shield 23 in the axial direction of the induction heating coil 21 may be longer than the length of the induction heating coil 21 in the same direction. By providing such a magnetic shield 23, leakage of magnetic flux to the outside can be suppressed, and the honeycomb structure can be heated more efficiently.

[0057] As shown in FIG. 4 , a glass or crystalline body 27 containing Al and / or Si may be disposed between the honeycomb structure 20 and the induction heating coil 21. Alternatively, a glass or crystalline body 27 containing Al and / or Si may be disposed between the induction heating coil 21 and the magnetic shield 23. By disposing the glass or crystalline body 27 containing Al and / or Si (hereinafter simply referred to as the "crystalline body 27") in these positions, electrical short circuits between the honeycomb structure 20, the induction heating coil 21, and the magnetic shield 23 can be prevented, and components such as moisture contained in the gas flowing through the honeycomb structure 20 can be prevented from coming into contact with the induction heating coil 21. While FIG. 4 shows the crystalline body 27 as a rectangular frame surrounding the honeycomb structure 20, the crystalline body 27 may have other shapes. For example, the crystalline body 27 may be a plate-like body overlapping only one side of the honeycomb structure 20. Note that while FIG. 4 exaggerates the distance between the honeycomb structure 20 and the induction heating coil 21, this is merely for ease of understanding.

[0058] The honeycomb structure 20 may have only one honeycomb structure portion 24, or may have a plurality of honeycomb structure portions 24 as shown in Fig. 2. Fig. 2 shows an embodiment in which three rectangular parallelepiped honeycomb structure portions 24 extending long in the axial direction AD (gas flow direction) are arranged in parallel. Two induction heating coils 21 are provided for each honeycomb structure portion 24, and one magnetic shield 23 is provided so as to surround the entire three honeycomb structure portions 24. The two induction heating coils 21 are arranged at the front and rear of the honeycomb structure portion 24 in the axial direction AD.

[0059] One of the multiple honeycomb structure sections 24 arranged in parallel is referred to as the first honeycomb structure section, and the one arranged adjacent to the first honeycomb structure section is referred to as the second honeycomb structure section. When the first honeycomb structure section has the conductor and / or magnetic material 25 as described above, the second honeycomb structure section does not need to have the conductor and / or magnetic material 25. This is because the second honeycomb structure section can be heated by heat generated in the first honeycomb structure section. Second honeycomb structure sections not having the conductor and / or magnetic material 25 may be arranged on both sides of the first honeycomb structure section having the conductor and / or magnetic material 25, or first honeycomb structure sections having the conductor and / or magnetic material 25 may be arranged on both sides of the second honeycomb structure section not having the conductor and / or magnetic material 25. The configuration of the second honeycomb structure section may be the same as the configuration of the honeycomb structure section 24 described above, except that it does not have the conductor and / or magnetic material 25.

[0060] Furthermore, multiple honeycomb structure sections 24 may be arranged in series in the axial direction AD. One of the multiple honeycomb structure sections 24 arranged in series is called the upstream honeycomb structure section, and the one arranged downstream of the upstream honeycomb structure section in the gas flow direction is called the downstream honeycomb structure section. When the upstream honeycomb structure section has a conductor and / or magnetic material 25 as described above, the downstream honeycomb structure section does not need to have a conductor and / or magnetic material 25. This is because the downstream honeycomb structure section can be heated by heat generated in the upstream honeycomb structure section. The configuration of the downstream honeycomb structure section may be the same as the configuration of the honeycomb structure section 24 described above, except that it does not have a conductor and / or magnetic material 25.

[0061] As shown in FIG. 1 , the first chamber 5 is disposed at one end of the honeycomb structure 20 in the axial direction AD. The first chamber 5 forms an internal space communicating with one end face of the honeycomb structure 20. The inner wall of the first chamber 5 may cover the entire outer surface of the outer peripheral wall 240, may cover only a portion of the outer surface, or may not cover the entire outer surface. When the inner wall of the first chamber 5 covers the entire outer surface of the outer peripheral wall 240, the tip (the lower end in the drawing) of the first chamber 5 may be disposed at the end face position on the other end side of the honeycomb structure 20, or may be disposed at a position beyond the end face on the other end side of the honeycomb structure 20 in the axial direction AD. Furthermore, when the inner wall of the first chamber 5 covers the entire outer surface of the outer peripheral wall 240, the induction heating coil 21 may be disposed outside the first chamber 5. The inner wall of the first chamber 5 covers at least a part of the outer peripheral wall 240, thereby suppressing leakage of the gas 10 in the first chamber 5 to the outside of the outer peripheral wall 240, and further improving the gas sealing performance. The second chamber 6 is arranged on the other end side of the honeycomb structure 20 in the axial direction AD. The second chamber 6 forms an internal space that is connected to the other end face of the honeycomb structure 20.

[0062] The gas 10 can be introduced into the honeycomb structure 20 from the first chamber 5. The honeycomb structure 20 can be arranged such that the axial direction AD is along the vertical direction. The first chamber 5 can be called the upstream chamber or upper chamber, and the second chamber 6 can be called the downstream chamber or lower chamber.

[0063] Gas 10 from the first chamber 5 enters cells 241a from one end face of the honeycomb structure 20, passes through cells 241a, and exits the honeycomb structure 20 from the other end face. As it passes through cells 241a, the gas 10 is thermally decomposed. When methane (CH4) is used as the gas 10 as described above, the generated carbon 11 is stored in the second chamber 6. The carbon 11 can be recovered through a first passage 61 connected to the bottom of the second chamber 6. A mixed gas 12 of hydrogen and methane is stored in the internal space of the second chamber 6. The mixed gas 12 can be recovered through a second passage 62 connected to the top of the second chamber 6. The mixed gas 12 is sent to a recovery device 4, which can purify or recover high-purity hydrogen.

[0064] Next, Fig. 8 is an explanatory diagram showing a modified example of the gas pyrolysis apparatus 1 of Fig. 1, Fig. 9 is an explanatory diagram showing an example of the state of the conductors and / or magnetic materials 25 in the honeycomb structure 20 of Fig. 8, and Fig. 10 is an explanatory diagram showing another example of the state of the conductors and / or magnetic materials 25 in the honeycomb structure 20 of Fig. 8. A honeycomb filter in which plugging portions 28 are formed at the ends of the cells 241a can be used as the honeycomb structure 20 or the honeycomb structure part 24. The cells 241a include first cells 241a1 plugged at the other end face and second cells 241a2 plugged at one end face.

[0065] 8 shows an embodiment in which the surfaces of the partition walls 241 are coated with a conductive and / or magnetic material 25, as described with reference to FIG. 6. In this case, the plugging portions 28 may be formed of a ceramic material such as cordierite, similar to the honeycomb structure portion 24 (the outer peripheral wall 240 and the partition walls 241). As described with reference to FIGS. 5 and 7, the conductive and / or magnetic material 25 may be present.

[0066] As shown in FIG. 9, the sealing portion 28 may be formed by the conductor and / or magnetic material 25 filled in the cell 241a.

[0067] Furthermore, as shown in Fig. 10, a first partition wall 2411 coated with the conductor and / or magnetic material 25 and a second partition wall 241b not coated with the conductor and / or magnetic material 25 may be provided. The second partition wall 2412 may be positioned between the first cell 241a1 and the second cell 241a2, and the first partition wall 2411 and the second partition wall 2412 may be adjacent to each other in the width direction or radial direction of the honeycomb structure section 24. By providing the second partition wall 2412, the passage resistance of the gas 10 can be reduced. The other configurations are the same as those in Fig. 1. The presence modes of the conductor and / or magnetic material 25 can be combined arbitrarily.

[0068] In the gas pyrolysis apparatus 1 shown in Figures 8 to 10, gas 10 flows into the first cell 241a1 from one end face, passes through the partition wall 241, reaches the second cell 241a2, and flows out the other end face through the second cell 241a2. As described above, when methane (CH4) is used as gas 10, the generated carbon 11 is stored (captured) in the first cell 241a1. A third passage 63 is connected to the first chamber 5. By backwashing the honeycomb structure 20 or the honeycomb structure portion 24, the carbon 11 in the first cell 241a1 can be recovered from the third passage 63. A hydrogen and methane mixed gas 12 can be recovered from the second cell 241a2 through a fourth passage 64 connected to the second chamber 6. The rest of the configuration is similar to that shown in Figure 1.

[0069] Second Embodiment. Figure 11 is an explanatory diagram showing a gas pyrolysis apparatus 1 according to a second embodiment of the present invention. While the first embodiment has been described as being primarily concerned with the thermal decomposition of methane (CH), the gas pyrolysis apparatus 1 may also be used to thermally decompose other gases 10. In the second embodiment, ammonia (NH) is introduced into the gas pyrolysis apparatus 1 as the gas 10. The ammonia is thermally decomposed into hydrogen and nitrogen in the gas pyrolysis unit 2 (NH → 0.5N + 1.5H). A mixed gas 13 of hydrogen, nitrogen, and ammonia is stored in the internal space of the second chamber 6. The mixed gas 13 can be recovered through a fifth passage 65 connected to the bottom of the second chamber 6. The mixed gas 13 is sent to the recovery device 4, which can purify or recover high-purity hydrogen. Other configurations are the same as those of the first embodiment.

[0070] Although the preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, the present invention is not limited to these examples. It is clear that a person skilled in the art to which the present invention pertains can conceive of various modifications and alterations within the scope of the technical ideas set forth in the claims, and it is understood that these also naturally fall within the technical scope of the present invention.

[0071] REFERENCE SIGNS LIST 1 Gas pyrolysis device 2 Gas pyrolysis unit 10 Gas 20 Honeycomb structure 21 Induction heating coil 23 Magnetic shield 24 Honeycomb structure part 240 Outer wall 241 Partition wall 241a Cell 25 Conductor and / or magnetic material 27 Glass or crystalline material

Claims

1. A gas pyrolysis unit for pyrolyzing gas, comprising: a honeycomb structure having one or more honeycomb structure sections having an outer peripheral wall and partition walls disposed inside the outer peripheral wall and defining a plurality of cells that form a flow path extending from one end face to the other end face; and an induction heating coil disposed on the outer periphery of the honeycomb structure, wherein at least one of the one or more honeycomb structure sections includes a conductor and / or a magnetic material.

2. The gas pyrolysis unit according to claim 1, wherein the conductive and / or magnetic material is present in at least a portion of the honeycomb structure in the radial and axial directions.

3. A gas pyrolysis unit as described in claim 2, wherein the conductive and / or magnetic material is present inside the outer peripheral wall, inside the partition wall, inside the cells, and / or on the outer peripheral wall.

4. A gas pyrolysis unit according to claim 3, wherein the conductive and / or magnetic material present inside the cells is filled in the cells or coated on the surfaces of the partition walls.

5. The gas pyrolysis unit of claim 1, further comprising a magnetic shield disposed around the outer periphery of said induction heating coil.

6. The gas pyrolysis unit according to claim 1, wherein said honeycomb structure portion contains at least one selected from the group consisting of cordierite, silicon carbide, silicon, silica and alumina.

7. The gas pyrolysis unit according to claim 1, wherein a glass or crystal material containing Al and / or Si is disposed between the honeycomb structure and the induction heating coil.

8. The gas pyrolysis unit according to claim 5, wherein a glass or crystal containing Al and / or Si is disposed between the induction heating coil and the magnetic shield.

9. A gas pyrolysis unit according to claim 1, wherein the conductive and / or magnetic material comprises at least one selected from the group consisting of Fe, Cr, Ni, Mn, Zn, Co, Cu and Si.

10. A gas pyrolysis unit according to claim 1, wherein the magnetic material has a Curie point of 300°C or higher.

11. The gas pyrolysis unit of claim 1, wherein at least one of said one or more honeycomb structures includes a catalyst.

12. A gas pyrolysis device comprising: a gas pyrolysis unit according to any one of claims 1 to 11; and a power supply circuit connected to the induction heating coil, said gas pyrolysis device being configured so that the honeycomb structure can be inductively heated by the magnetic flux from the induction heating coil when the gas is passed through the cell.

13. The gas pyrolysis apparatus according to claim 12, wherein the gas is a gas containing hydrogen as atoms, and the gas pyrolysis unit is configured to obtain hydrogen by pyrolyzing the gas.

14. The gas pyrolysis apparatus of claim 13, wherein the gas comprises one or more of hydrocarbons including naphtha, hydroxides, ammonia, oxynitrides, hydrogen sulfide, and / or biogas.

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