Gas thermal decomposition unit and gas thermal decomposition apparatus

Abstract

The gas thermal decomposition unit (2) of the present application is provided with: a honeycomb structure (20) having one or more honeycomb structure portions (24) having an outer peripheral wall (240) and a partition wall (241) provided on the inner side of the outer peripheral wall (240) and partitioning a plurality of cells (241a) to form flow paths extending from one end face to the other end face; and an induction heating coil (21) disposed on the outer periphery of the honeycomb structure (20), at least one of the one or more honeycomb structure portions (24) containing a conductor and / or a magnetic body (25).

Description

Technical Field

[0001] The present invention relates to a gas thermal decomposition unit and a gas thermal decomposition apparatus for thermally decomposing gases. Background Technology

[0002] As a countermeasure against global warming, the focus is on H2 purification technology that can produce H2 as a carbon-free energy source cheaply and in large quantities without emitting CO2.

[0003] Water electrolysis is a H2 purification technology that does not emit CO2, but its high cost is a challenge. Another technology besides water electrolysis is the thermal decomposition of hydrocarbons, especially natural gas or methane. The carbon produced by the thermal decomposition of methane is recovered as a solid, thereby suppressing CO2 emissions. On the other hand, the carbon produced as a solid, especially in the case of catalyst-driven thermal decomposition, faces the problem of the generated carbon quickly covering the catalyst and causing deactivation, necessitating efficient removal from the reactor. External heating of the reaction tank during the thermal decomposition of methane can be considered as a heating method, but there are challenges in methods that ensure the entire reaction tank reaches the decomposition temperature as early as possible and that the thermal decomposition of the gases within the tank proceeds uniformly.

[0004] Patent Document 1 below proposes a system for decomposing hydrocarbons, such as natural gas or methane, into hydrogen and carbon using a reaction tank comprising a particle layer made of conductive carbon, graphite, etc., and an electromagnetic induction unit that heats it.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: European Patent Application Publication No. 4126757 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] The system proposed in Patent Document 1 does not rely on external heating, but rather on induction heating of conductive carbon and graphite within the tank to promote the thermal decomposition of hydrocarbons, thus potentially enabling effective heating. However, the relationship between the hydrocarbons supplied as gas to the tank and the conductive carbon serving as the heating element is not always consistent, making uniform heating sometimes difficult.

[0010] The present invention was made to solve the problems mentioned above, and one of its objectives is to provide a gas thermal decomposition unit and a gas thermal decomposition device that can heat the gas more uniformly and improve the thermal decomposition efficiency of the gas.

[0011] Solution for solving the problem

[0012] Option 1. In one embodiment of the present invention, a gas thermal decomposition unit is provided for thermally decomposing a gas, comprising: a honeycomb structure having one or more honeycomb structural portions having an outer peripheral wall and partition walls disposed on the inner side of the outer peripheral wall and dividing to form a plurality of compartments, the plurality of compartments forming a flow path extending from one end face to another; and an induction heating coil disposed on the outer periphery of the honeycomb structure, at least one of the one or more honeycomb structural portions comprising a conductor and / or a magnetic material.

[0013] Option 2. The present invention may relate to the gas thermal decomposition unit described in Option 1, wherein a conductor and / or a magnetic material is present in at least a radial and axial portion of the honeycomb structure.

[0014] Option 3. The present invention may relate to the gas thermal decomposition unit described in Option 2, wherein conductors and / or magnetic materials are present inside the outer peripheral wall, inside the partition wall, inside the compartment and / or on the outer peripheral wall.

[0015] Option 4. The present invention may relate to the gas thermal decomposition unit described in Option 3, wherein conductors and / or magnetic materials present inside the compartment fill the compartment or are coated on the surface of the compartment wall.

[0016] Option 5. The present invention may relate to a gas thermal decomposition unit as described in any one of Options 1 to 4, wherein it further comprises a magnetic shielding element disposed on the outer periphery of an induction heating coil.

[0017] Option 6. The present invention may relate to a gas thermal decomposition unit as described in any one of Options 1 to 5, wherein the honeycomb structure comprises at least one selected from the group consisting of cordierite, silicon carbide, silicon, silicic acid and alumina.

[0018] Scheme 7. The present invention may relate to a gas thermal decomposition unit as described in any one of Schemes 1 to 6, wherein a glass or crystal containing Al and / or Si is disposed between the honeycomb structure and the induction heating coil.

[0019] Option 8. The present invention may relate to the gas thermal decomposition unit described in Option 5, wherein a glass or crystal containing Al and / or Si is disposed between the induction heating coil and the magnetic shield.

[0020] Scheme 9. The present invention may relate to a gas thermal decomposition unit as described in any one of Schemes 1 to 8, wherein the conductor and / or magnetic material comprises at least one selected from the group consisting of Fe, Cr, Ni, Mn, Zn, Co, Cu and Si.

[0021] Option 10. The present invention may relate to a gas thermal decomposition unit as described in any one of Options 1 to 9, wherein the magnetic body has a Curie point of 300°C or higher.

[0022] Option 11. The present invention may relate to a gas thermal decomposition unit as described in any one of Options 1 to 10, wherein at least one of one or more honeycomb structures contains a catalyst.

[0023] Option 12. In one embodiment of the present invention, a gas thermal decomposition apparatus is provided, comprising: a gas thermal decomposition unit as described in any one of Options 1 to 11; and a power supply circuit connected to an induction heating coil, configured to inductively heat a honeycomb structure using magnetic flux from the induction heating coil when gas is passed through a compartment.

[0024] Option 13. The present invention may relate to the gas thermal decomposition apparatus described in Option 12, wherein the gas is a gas containing hydrogen as atoms, and is configured to obtain hydrogen by thermal decomposition of the gas by a gas thermal decomposition unit.

[0025] Option 14. The present invention may relate to the gas thermal decomposition apparatus described in Option 13, wherein the gas includes one or more of naphtha-containing hydrocarbons, hydroxides, ammonia, nitrogen oxides, hydrogen sulfide, and / or biogas.

[0026] Invention Effects

[0027] According to one embodiment of the gas thermal decomposition unit and gas thermal decomposition apparatus of the present invention, since at least one of the one or more honeycomb structure portions includes a conductor and / or a magnetic body, the relationship between the conductor and / or magnetic body as a heating element and the gas can be managed more reliably, the gas can be heated more uniformly, and the gas thermal decomposition efficiency can be improved. Attached Figure Description

[0028] Figure 1 This is an explanatory diagram showing the gas thermal decomposition apparatus 1 according to Embodiment 1 of the present invention.

[0029] Figure 2 It means Figure 1 A three-dimensional view of gas thermal decomposition unit 2.

[0030] Figure 3 It means Figure 1 The circuit diagram of power supply circuit 3.

[0031] Figure 4 It means Figure 2 The front view of the honeycomb structure 20 and its surroundings.

[0032] Figure 5 It means Figure 2 An illustrative diagram of a first example of the presence of conductors and / or magnetic materials 25 in a honeycomb structure 20.

[0033] Figure 6 It means Figure 2 A second illustration of the manner in which conductors and / or magnetic materials 25 are present in the honeycomb structure 20.

[0034] Figure 7 It means Figure 2 A third illustration of the manner in which conductors and / or magnetic materials 25 are present in the honeycomb structure 20.

[0035] Figure 8 It means Figure 1 A diagram illustrating a modified example of the gas thermal decomposition apparatus 1.

[0036] Figure 9 It means Figure 8 An illustrative diagram illustrating an example of the presence of conductors and / or magnetic materials 25 in a honeycomb structure 20.

[0037] Figure 10 It means Figure 8 An illustrative diagram of another example of the presence of conductors and / or magnetic materials 25 in a honeycomb structure 20.

[0038] Figure 11 This is an explanatory diagram showing the gas thermal decomposition apparatus 1 according to Embodiment 2 of the present invention. Detailed Implementation

[0039] Hereinafter, embodiments for carrying out the present invention will be described with reference to the accompanying drawings. The present invention is not limited to each embodiment, and can be realized by modifying the constituent elements without departing from its spirit. Furthermore, various inventions can be formed by appropriately combining the multiple constituent elements disclosed in each embodiment. For example, several constituent elements may be deleted from all the constituent elements shown in the embodiments. Furthermore, constituent elements from different embodiments may be appropriately combined.

[0040] Implementation method 1.

[0041] Figure 1 This is an explanatory diagram showing the gas thermal decomposition apparatus 1 according to Embodiment 1 of the present invention. Figure 2 It means Figure 1 A three-dimensional view of gas thermal decomposition unit 2. Figure 3 It means Figure 1 The circuit diagram of power supply circuit 3. Figure 4 It means Figure 2 A front view of the honeycomb structure 20 and its surroundings. Additionally, Figure 5 It means Figure 2 An explanatory diagram of a first example of the manner in which conductors and / or magnetic materials 25 are present in a honeycomb structure 20. Figure 6 It means Figure 2 A second example illustrating the manner in which conductors and / or magnetic materials 25 are present in the honeycomb structure 20. Figure 7 It means Figure 2 A third illustration of the manner in which conductors and / or magnetic materials 25 are present in the honeycomb structure 20.

[0042] Figure 1 as well as Figure 2 The gas thermal decomposition apparatus 1 and gas thermal decomposition unit 2 shown are devices and units for thermally decomposing gas 10. Gas 10 is a gas containing hydrogen atoms, and the gas thermal decomposition apparatus 1 is configured to thermally decompose gas 10 to obtain hydrogen via the gas thermal decomposition unit 2. The hydrogen obtained from the gas thermal decomposition apparatus 1 is discharged from the gas thermal decomposition apparatus 1 and recovered by the recovery device 4. Examples of the recovery device 4 include, for instance, a hydrogen recovery system equipped with a purification mechanism as needed.

[0043] A gas containing hydrogen as an atom is a gas whose chemical formula includes hydrogen (H). Such gases can include one or more of hydrocarbons, hydroxides, ammonia, nitrogen oxides, hydrogen sulfide, and / or biological gases. As an example, hydrocarbons include naphtha. Figure 1 As an example, a gas thermal decomposition apparatus 1 is shown in which methane (CH4) is introduced as gas 10 into the gas thermal decomposition apparatus 1, and the methane is thermally decomposed into hydrogen and carbon 11 (CH4 → C (solid) + 2H2). A mixed gas 12 of hydrogen and methane is recovered in a recovery unit 4. In the recovery unit 4, high-purity hydrogen can be generated or recovered by means of a PSA (pressure swing adsorption) hydrogen separation membrane or the like.

[0044] like Figure 1 As shown, the gas thermal decomposition device 1 includes a gas thermal decomposition unit 2, a power supply circuit 3, a first chamber 5, and a second chamber 6.

[0045] As described above, the gas thermal decomposition unit 2 is used for thermally decomposing gases. The gas thermal decomposition unit 2 has a honeycomb structure 20 and an induction heating coil 21.

[0046] The cellular structure 20 has one or more cellular structure parts 24. Figure 2 The image shows a honeycomb structure 20 having multiple honeycomb structural sections 24. Specifically, as shown... Figure 2As shown, the honeycomb structure 24 has: an outer peripheral wall 240; and partition walls 241 disposed on the inner side of the outer peripheral wall 240, dividing to form a plurality of compartments 241a, which form a flow path extending from one end face to another. The honeycomb structure 24 can be columnar in 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 can be the extending direction of the compartments 241a. The ratio (aspect ratio) of the axial length of the honeycomb structure 24 to the diameter or width of the end face of the honeycomb structure 24 is arbitrary. A columnar shape can include a shape in which the axial length of the honeycomb structure 24 is shorter than the diameter or width of the end face (flat shape). The shape of the honeycomb structure 24 is not particularly limited, such as Figure 2 As shown, it can be set as a columnar shape with a quadrilateral end face (quadrangular prism shape), a columnar shape with a circular or elliptical end face, or a columnar shape with fewer end faces or multiple angles (triangle, pentagon, hexagon, heptagon, octagon, etc.).

[0047] The material of the honeycomb structure portion 24 (outer peripheral wall 240 and partition wall 241) is not particularly limited, and is usually formed of ceramic material. The honeycomb structure portion 24 preferably comprises at least one material selected from the group consisting of cordierite, silicon carbide, silicon, silica, and alumina. More specifically, examples of the honeycomb structure portion 24 include cordierite, silicon carbide, aluminum titanate, silicon nitride, mullite, alumina, silicon dioxide, silicon-silicon carbide composite materials, and silicon carbide-cordierite composite materials. More preferably, it is formed of cordierite, alumina, silicon dioxide, silicon carbide, or silicon-silicon carbide composite materials. In this specification, silicon carbide-based and cordierite-based refer to the outer peripheral wall 240 and partition wall 241 containing 50% by mass or more of silicon carbide or cordierite as a whole of the outer peripheral wall 240 and partition wall 241.

[0048] The shape of compartment 241a is not particularly limited. In a cross-section orthogonal to the central axis of the honeycomb structure 20, it is preferably a polygon such as a triangle, quadrilateral, pentagon, hexagon, or octagon, a circle, or an ellipse, or it may be other irregular shapes. A polygon is preferred.

[0049] The thickness of the partition 241 is preferably 0.05 to 0.50 mm, and more preferably 0.07 to 0.38 mm from the perspective of ease of manufacture. For example, if it is 0.05 mm or more, the strength of the honeycomb structure 20 is further improved, and if it is 0.50 mm or less, pressure loss can be reduced. In addition, the thickness of the partition 241 is an average value determined by observing the central axial section under a microscope.

[0050] The porosity of the partition 241 is preferably 20% to 70%. From the perspective of ease of manufacture, the porosity of the partition 241 is preferably 20% or more, and if it is less than 70%, the strength of the honeycomb structure 20 can be maintained.

[0051] The average pore size of the partition 241 is preferably 2 to 30 μm, more preferably 5 to 25 μm. If the average pore size of the partition 241 is 2 μm or more, manufacturing becomes easier; if it is 30 μm or less, the strength of the honeycomb structure 20 can be maintained. It should be noted that, in this specification, when referring to "average pore size" and "porosity," they refer to the average pore size and porosity measured by mercury porosimetry.

[0052] The density of compartment 241a is not particularly limited, but is preferably 5 to 150 compartments / cm³. 2 The range is more preferably 16 to 100 compartments / cm². 2 The range is further preferably 31–100 compartments / cm². 2 The range.

[0053] Such a honeycomb structure 24 is produced by forming a honeycomb-shaped body by shaping a clay containing ceramic raw material into a honeycomb shape with partitions 241 dividing it into multiple compartments 241a. These multiple compartments 241a extend from one end face to the other, forming a flow path for fluid. The honeycomb-shaped body is then dried and fired. Furthermore, the outer peripheral wall 240 can be an outer peripheral wall 240 integrally extruded with the honeycomb-shaped body, or it can be formed by grinding the outer periphery of the honeycomb-shaped body or sintered honeycomb body after forming or firing to create a predetermined shape. A coating material is then applied to the ground outer periphery of the honeycomb-shaped body or sintered honeycomb body to form an outer peripheral coating, and the resulting outer peripheral wall is used as the outer peripheral wall 240 (in this case, only the outer peripheral coating becomes the outer peripheral wall 240). Alternatively, the outer peripheral wall 240 integrally extruded with the honeycomb-shaped body may not be ground, but an outer peripheral coating may be formed thereon (the outer peripheral wall 240 has a double-layer structure of the outer peripheral wall of the honeycomb sintered body, etc., and an outer peripheral coating).

[0054] The honeycomb structure 20 is not limited to an integral honeycomb structure 20 with partitions 241 formed integrally. For example, it can also be a honeycomb structure 20 (jointed honeycomb structure) with the following structure: a plurality of columnar honeycomb units having ceramic partitions 241, which are divided by partitions 241 to form multiple compartments 241a that serve as flow paths for fluids, are combined by a bonding material layer.

[0055] At least one of the one or more honeycomb structure portions 24 in this embodiment includes a conductor and / or a magnetic body 25. The gas thermal decomposition apparatus 1 of this embodiment is configured such that when gas is passed through the compartment 241a, the honeycomb structure 20 can be inductively heated by magnetic flux from the induction heating coil 21.

[0056] In order to efficiently thermally decompose the gas, it is preferable to heat the gas uniformly. As in Patent Document 1 mentioned above, simply placing the heating element into the tank does not guarantee a consistent relationship between the gas and the heating element within the tank, thus sometimes making uniform heating difficult. However, by including a conductor and / or a magnetic material 25 in a structure of a predetermined shape, such as the honeycomb structure 24, the relationship between the gas and the conductor and / or magnetic material 25 can be more reliably managed within the honeycomb structure 24, resulting in more uniform heating of the gas and improved thermal decomposition efficiency.

[0057] Furthermore, by including conductors and / or magnetic materials 25 in the honeycomb structure 24, the effective area for thermal decomposition per unit volume can be increased. Additionally, by ensuring gas flow paths (compartments 241a) within the honeycomb structure 20, gas thermal decomposition can be effectively performed, thereby improving the recovery efficiency of the decomposed gas.

[0058] The following description uses the accompanying drawings. Conductors and / or magnetic materials 25 may be present in at least a portion of the radial and axial directions AD within the honeycomb structure 20. Additionally, conductors and / or magnetic materials 25 may be present inside the outer peripheral wall 240, inside the partition wall 241, inside the compartment 241a, and / or on the outer peripheral wall 240. Conductors and / or magnetic materials 25 present inside the compartment 241a may fill the compartment 241a or be coated on the surface of the partition wall 241.

[0059] exist Figure 5 The diagram illustrates a manner in which a conductor and / or magnetic material 25 is filled into a portion of a compartment 241a. The conductor and / or magnetic material 25 may have a columnar shape that matches the shape of the compartment 241a. The conductor and / or magnetic material 25 may have this shape before being filled into the compartment 241a, or it may acquire this shape after being filled into the compartment 241a. In other words, the conductor and / or magnetic material 25 may constitute a shaped material with a predetermined shape, or it may constitute a paste-like amorphous material.

[0060] The shaped and unshaped materials can also be composed of a composite of conductors and / or magnetic materials 25 and bonding or adhesive materials. Examples of bonding materials include those primarily composed of metal or glass. Examples of adhesive materials include those primarily composed of silicon dioxide or alumina. In addition to bonding or adhesive materials, organic or inorganic substances may be further included. The conductors and / or magnetic materials 25 can completely fill the honeycomb structure 20 from one end face to the other. Alternatively, the conductors and / or magnetic materials 25 can fill the honeycomb structure 20 from one end face to the middle of the compartment 241a.

[0061] The conductor and / or magnetic material 25 is heated by magnetic flux from the induction heating coil 21, and the honeycomb structure 24 is heated by this heat. By filling a portion of the compartment 241a with the conductor and / or magnetic material 25, the compartment 241a can function as a heater in the honeycomb structure 20.

[0062] exist Figure 6 The diagram illustrates a manner in which conductors and / or magnetic materials 25 are coated on the surface of partition 241. In the illustrated manner, conductors and / or magnetic materials 25 are shown coated on the surface of the partition 241 of all compartments 241a, but conductors and / or magnetic materials 25 may also be coated on the surface of the partition 241 of only a portion of compartments 241a.

[0063] The conductors and / or magnetic materials 25 coated on the surface of the partition 241 can form a coating together with a fixing material in which the conductors and / or magnetic materials 25 are dispersed. As the fixing material, glass, crystallized glass, ceramics, or glass, crystallized glass, ceramics, etc., containing silica, boric acid, or borosilicate can be used. The conductors and / or magnetic materials 25 can extend from one end face of the honeycomb structure 24 to the other end face, or can extend along a portion of the axial direction AD. The amount of conductors and / or magnetic materials 25 contained in the coating can be varied with respect to the radial and axial directions AD within the honeycomb structure 20.

[0064] The conductor and / or magnetic material 25 is heated by magnetic flux induction from the induction heating coil 21, and the honeycomb structure portion 24 is heated by this heat. By coating the conductor and / or magnetic material 25 on the surface of the partition wall 241, the compartment 241a can function as a heater in the honeycomb structure 20, similar to the case where the conductor and / or magnetic material 25 is filled into the compartment 241a. On the other hand, the gas 10 can also pass through the compartment 241a where the surface of the partition wall 241 is coated with the conductor and / or magnetic material 25. In the case where the conductor and / or magnetic material 25 is coated on the surface, the passage resistance of the gas 10 can be reduced compared to the case where the conductor and / or magnetic material 25 is filled into the compartment 241a.

[0065] Figure 7 This diagram illustrates the arrangement of conductors and / or magnetic materials 25 within the outer peripheral wall 240 and partition walls 241. The honeycomb structure 24 (outer peripheral wall 240 and partition walls 241) is typically formed from a ceramic material such as cordierite. By fabricating the honeycomb structure 24 with the conductors and / or magnetic materials 25 mixed or coated onto the ceramic material, it is possible to have the conductors and / or magnetic materials 25 present within the outer peripheral wall 240 and partition walls 241. In this manner, the outer peripheral wall 240 and partition walls 241 can function as heaters within the honeycomb structure 20. The arrangement of the conductors and / or magnetic materials 25 can be arbitrarily combined.

[0066] The conductor 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. The conductor and / or magnetic material 25 may contain, for example, the following: remaining portion Co-20 wt% Fe, remaining portion Co-25 wt% Ni-4 wt% Fe, remaining portion Fe-15–35 wt% Co, remaining portion Fe-17 wt% Co-2 wt% Cr-1 wt% Mo, remaining portion Fe-49 wt% Co-2 wt% V, remaining portion Fe-18 wt% Co-10 wt% Cr-2 wt% Mo-1 wt% Al, remaining portion Fe-27 wt% Co-1 wt% Nb, remaining portion Fe-20 wt% Co-1 wt% Cr-2 wt% V, remaining portion Fe-35 wt% Co-1 wt% Cr, pure cobalt, pure iron, electromagnetic soft iron, remaining portion Fe-0.1–0.5 wt% Mn, remaining portion Fe-3 wt% Si, remaining portion F Metals including e-6.5 mass% Si, the remainder Fe-18 mass% Cr, the remainder Fe-16 mass% Cr-8 mass% Al, the remainder Ni-13 mass% Fe-5.3 mass% Mo, the remainder Fe-45 mass% Ni, the remainder Fe-10 mass% Si-5 mass% Al, the remainder Fe-36 mass% Ni, the remainder Fe-45 mass% Ni, the remainder Fe-35 mass% Cr, the remainder Fe-13 mass% Cr-2 mass% Si, the remainder Fe-20 mass% Cr-2 mass% Si-2 mass% Mo, the remainder Fe-20 mass% Co-1 mass% V, the remainder Fe-13 mass% Cr-2 mass% Si, and the remainder Fe-17 mass% Co-2 mass% Cr-1 mass% Mo. Additionally, oxides such as Mn-Zn ferrite, Cu-Zn ferrite, Ni-Zn ferrite, and Cu-Zn-Mg ferrite can also be cited as conductors and / or magnetic materials 25. These conductors and / or magnetic materials 25 have different Curie points for each material, and are appropriately selected according to the heating temperature required for the thermal decomposition of the gas.

[0067] At least one of the one or more honeycomb structure portions 24 may contain a catalyst. Examples of catalysts include Ni, Fe, and Ru, which are used to lower the decomposition temperature. The catalyst is disposed on the wall of the compartment 241a in contact with the gas 10. The catalyst can be disposed in a compartment different from the compartment 241a containing the conductor and / or magnetic material 25, or it can be disposed in the same compartment 241a as the conductor and / or magnetic material 25. By disposing of it in another compartment 241a, the effects of chemical reactions or the like between the catalyst and the conductor and / or magnetic material 25 can be suppressed. On the other hand, by disposing of it in the same compartment 241a, the catalyst can be brought into contact with the conductor and / or magnetic material 25, and by directly transferring heat from the conductor and / or magnetic material 25 to the catalyst, heating can be performed more efficiently to reach the desired temperature.

[0068] An 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 also be coaxial with the central axis of the honeycomb structure 20. Figure 1 The diagram shows a strip-shaped conductor 210 with a rectangular cross-section, but the shape of the conductor 210 is arbitrary, and it can have other shapes such as circular or tubular. The conductor 210 can be molded from an insulating material 211. As the insulating material 211, alumina, aluminum silicate, mullite, silica, and / or heat-resistant resins can be used, etc. Figure 1 The diagram illustrates how a conductor 210, molded from insulating material 211, is embedded in the outer surface of the outer peripheral wall 240 of a honeycomb structure 20.

[0069] A power supply circuit 3 is connected to the induction heating coil 21. For example... Figure 3As shown, 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, used when it is desired to amplify the current flowing through the induction heating coil 21, 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 and the secondary coil 222b is N:1. N is a number greater than 1, and the transformer 222 is capable of amplifying the AC 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 can be connected in series with the resonant capacitor 223 and can also be connected together with the resonant capacitor 223 to the two ends of the secondary coil 222b. When the power supply is AC, there is no need to convert it to AC current, thus a high-frequency converter can be used without an inverter. There is no specified frequency for use in alternating current; a frequency of 10–400 kHz is appropriate, and 30–100 kHz is preferred.

[0070] By supplying alternating current 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 inductively heated by the magnetic flux from the induction heating coil 21.

[0071] By selecting the Curie point of the conductor and / or magnetic material 25, the heating temperature of the conductor and / or magnetic material 25 based on induction heating can be adjusted. Heating of the conductor and / or magnetic material 25 is intended for the thermal decomposition of gases, but due to excessive temperature rise, reactions different from the target thermal decomposition reaction may occur, or 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 adverse conditions can be suppressed. 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, more preferably 700°C or higher.

[0072] The gas thermal decomposition unit 2 may also have a magnetic shield 23 disposed around the periphery of the induction heating coil 21. The magnetic shield 23 may be configured 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 component disposed around the periphery of the induction heating coil 21 and having walls 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.

[0073] like Figure 4 As shown, a glass or crystal containing Al and / or Si can be disposed between the honeycomb structure 20 and the induction heating coil 21. Additionally, a glass or crystal containing Al and / or Si can be disposed between the induction heating coil 21 and the magnetic shield 23. By disposing a glass or crystal containing Al and / or Si (hereinafter referred to as "crystal 27") at these locations, electrical short circuits between the honeycomb structure 20, the induction heating coil 21, and the magnetic shield 23 can be prevented. Furthermore, it is possible to prevent components such as moisture contained in the gas flowing in the honeycomb structure 20 from contacting the induction heating coil 21. Figure 4 The diagram shows crystal 27 as a rectangular frame surrounding the honeycomb structure 20, etc., but crystal 27 can have other shapes. For example, crystal 27 can be a plate-like body that overlaps only one side of the honeycomb structure 20, etc. Furthermore, in... Figure 4 The spacing between the honeycomb structure 20 and the induction heating coil 21 is shown to be relatively large, but this is only for ease of understanding.

[0074] The honeycomb structure 20 may have only one honeycomb structure part 24, but it may also be as follows: Figure 2 The diagram shows multiple honeycomb structure sections 24. Figure 2 The diagram shows three cuboid honeycomb structures 24 arranged side-by-side, extending elongatedly along the axial direction AD (gas flow direction). Each honeycomb structure 24 is provided with two induction heating coils 21, and a magnetic shield 23 is provided to surround the entirety of the three honeycomb structures 24. The two induction heating coils 21 are positioned at the front and rear of the honeycomb structure 24 along the axial direction AD.

[0075] One of the multiple honeycomb structure sections 24 arranged side by side is referred to as the first honeycomb structure section, and the honeycomb structure section arranged adjacent to the first honeycomb structure section is referred to as the second honeycomb structure section. When the first honeycomb structure section has a conductor and / or magnetic material 25 as described above, the second honeycomb structure section may not have a conductor and / or magnetic material 25. This is because the heat generated in the first honeycomb structure section can be used to heat the second honeycomb structure section. Second honeycomb structure sections without conductors and / or magnetic materials 25 may be arranged on both sides of the first honeycomb structure section with conductors and / or magnetic materials 25, or first honeycomb structure sections with conductors and / or magnetic materials 25 may be arranged on both sides of the second honeycomb structure section without conductors and / or magnetic materials 25. The structure of the second honeycomb structure section can be the same as the structure of the honeycomb structure section 24 described above, except that it does not have conductors and / or magnetic materials 25.

[0076] Alternatively, multiple honeycomb structures 24 can be arranged in series along the axial direction AD. One of the multiple honeycomb structures 24 arranged in series is called the upstream honeycomb structure, and the honeycomb structure arranged downstream of the upstream honeycomb structure in the gas flow direction is called the downstream honeycomb structure. When the upstream honeycomb structure has a conductor and / or magnetic material 25 as described above, the downstream honeycomb structure may not have a conductor and / or magnetic material 25. This is because the heat generated in the upstream honeycomb structure can be used to heat the downstream honeycomb structure. The structure of the downstream honeycomb structure can be the same as that of the honeycomb structure 24 described above, except that it does not have a conductor and / or magnetic material 25.

[0077] like Figure 1 As shown, the first chamber 5 is disposed at one end of the honeycomb structure 20 along 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, or only a portion of the outer surface, or it 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 front end of the first chamber 5 (the lower end in the figure) may be disposed at the end face of the other end of the honeycomb structure 20, or it may be disposed at a position extending beyond the end face of the other end of the honeycomb structure 20 along the axial direction AD. In addition, 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 on the outside of the first chamber 5. By having the inner wall of the first chamber 5 cover at least a portion of the outer peripheral wall 240, leakage of gas 10 from the first chamber 5 to the outside of the outer peripheral wall 240 can be suppressed, further improving gas tightness. The second chamber 6 is disposed at the other end of the honeycomb structure 20 along the axial direction AD. The second chamber 6 forms an internal space that communicates with the other end face of the honeycomb structure 20.

[0078] Gas 10 can be introduced into the honeycomb structure 20 from the first chamber 5. The honeycomb structure 20 can be configured such that the axial direction AD is along the vertical direction. The first chamber 5 can be referred to as the upstream chamber or upper chamber, and the second chamber 6 can be referred to as the downstream chamber or lower chamber.

[0079] Gas 10 from the first chamber 5 enters compartment 241a from one end face of the honeycomb structure 20 and exits from the other end face of the honeycomb structure 20 through compartment 241a. During its passage through compartment 241a, gas 10 is thermally decomposed. As described above, when methane (CH4) is used as gas 10, the generated carbon 11 accumulates in the second chamber 6. Carbon 11 can be recovered through a first passage 61 connected to the lower part of the second chamber 6. Additionally, a mixed gas 12 of hydrogen and methane accumulates in the internal space of the second chamber 6. Mixed gas 12 can be recovered through a second passage 62 connected to the upper part of the second chamber 6. Mixed gas 12 is sent to a recovery device 4, which is capable of purifying or recovering high-purity hydrogen.

[0080] then, Figure 8 It means Figure 1 A diagram illustrating a modified example of the gas thermal decomposition apparatus 1. Figure 9 It means Figure 8 An illustrative diagram illustrating an example of the presence of conductors and / or magnetic materials 25 in a honeycomb structure 20. Figure 10 It means Figure 8 This is an illustration of another example of the presence of conductors and / or magnetic materials 25 in the honeycomb structure 20. As the honeycomb structure 20 or honeycomb structure section 24, a honeycomb filter with sealing portions 28 formed at the ends of the compartments 241a can be used. The compartments 241a include a first compartment 241a1 sealed at one end face and a second compartment 241a2 sealed at one end face.

[0081] exist Figure 8 In, if using Figure 6 As explained, a method is shown in which a conductor and / or magnetic material 25 is coated on the surface of the partition 241. In this case, the sealing portion 28 can be formed of a ceramic material such as cordierite, similar to the honeycomb structure portion 24 (outer peripheral wall 240 and partition 241). Alternatively, it can be used... Figure 5 and Figure 7 As described, there are conductors and / or magnetic materials 25.

[0082] In addition, such as Figure 9 As shown, the sealing portion 28 can also be formed by a conductor and / or magnetic material 25 filled in the compartment 241a.

[0083] And, as Figure 10As shown, a first partition 2411 coated with conductors and / or magnetic materials 25 and a second partition 241b uncoated with conductors and / or magnetic materials 25 can also be provided. The second partition 2412 can be located between the first compartment 241a1 and the second compartment 241a2, and the first partition 2411 and the second partition 2412 can be adjacent in the width direction or radial direction of the honeycomb structure portion 24. By providing the second partition 2412, the resistance to gas passage 10 can be reduced. Other structures are similar to... Figure 1 The structures are the same. The conductors and / or magnetic materials 25 can be present in any combination.

[0084] exist Figures 8 to 10 In the gas thermal decomposition apparatus 1 shown, gas 10 flowing into the first compartment 241a1 from one end face passes through partition wall 241 to the second compartment 241a2, and flows out from the other end face through the second compartment 241a2. As described above, when methane (CH4) is used as gas 10, the generated carbon 11 is accumulated (captured) in the first compartment 241a1. A third passage 63 is connected to the first chamber 5. By backwashing the honeycomb structure 20 or the honeycomb structure section 24, the carbon 11 in the first compartment 241a1 can be recovered from the third passage 63. A mixed gas 12 of hydrogen and methane from the second compartment 241a2 can be recovered through a fourth passage 64 connected to the second chamber 6. Other structures are similar to... Figure 1 The structures are the same.

[0085] Implementation Method 2

[0086] Figure 11 This is an explanatory diagram showing the gas thermal decomposition apparatus 1 according to Embodiment 2 of the present invention. In Embodiment 1, the thermal decomposition of methane (CH4) was mainly described, but the gas thermal decomposition apparatus 1 can also be used to thermally decompose other gases 10. In this Embodiment 2, ammonia (NH3) is introduced into the gas thermal decomposition apparatus 10 as gas 10. Ammonia is thermally decomposed into hydrogen and nitrogen (NH3→0.5N2+1.5H2) in the gas thermal decomposition unit 2. A mixed gas 13 of hydrogen, nitrogen, and ammonia is accumulated in the internal space of the second chamber 6. The mixed gas 13 can be recovered through the fifth passage 65 connected to the lower part 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 structures are the same as those in Embodiment 1.

[0087] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited to these examples. Various modifications and alterations will be readily apparent to those skilled in the art to which this invention pertains, within the scope of the technical concept set forth in the claims, and these are, of course, also understood to fall within the technical scope of this invention.

[0088] Symbol Explanation

[0089] 1—Gas thermal decomposition apparatus; 2—Gas thermal decomposition unit; 10—Gas; 20—Honeycomb structure; 21—Induction heating coil; 23—Magnetic shield; 24—Honeycomb structure section; 240—Outer peripheral wall; 241—Partition wall; 241a—Compartment; 25—Conductor and / or magnetic material; 27—Glass or crystal.

Claims

1. A gas thermal decomposition unit for thermally decomposing a gas. The gas thermal decomposition unit is characterized by having: A honeycomb structure having one or more honeycomb structural portions, each honeycomb structural portion having an outer peripheral wall and partition walls disposed on the inner side of the outer peripheral wall and dividing it into multiple compartments, the multiple compartments forming a flow path extending from one end face to another; and An induction heating coil is disposed on the outer periphery of the honeycomb structure. At least one of the one or more cellular structures contains a conductor and / or a magnetic material.

2. The gas thermal decomposition unit according to claim 1, characterized in that, The conductor and / or magnet are present in at least a portion of the radial and axial portions of the honeycomb structure.

3. The gas thermal decomposition unit according to claim 2, characterized in that, The conductor and / or magnet is present inside the outer peripheral wall, inside the partition wall, inside the compartment, and / or on the outer peripheral wall.

4. The gas thermal decomposition unit according to claim 3, characterized in that, The conductors and / or magnetic materials present inside the compartment fill the compartment or are coated on the surface of the compartment wall.

5. The gas thermal decomposition unit according to claim 1, characterized in that, It also includes a magnetic shielding component disposed on the outer periphery of the induction heating coil.

6. The gas thermal decomposition unit according to claim 1, characterized in that, The honeycomb structure comprises at least one selected from the group consisting of cordierite, silicon carbide, silicon, silicic acid, and alumina.

7. The gas thermal decomposition unit according to claim 1, characterized in that, A glass or crystal containing Al and / or Si is disposed between the honeycomb structure and the induction heating coil.

8. The gas thermal decomposition unit according to claim 5, characterized in that, A glass or crystal containing Al and / or Si is disposed between the induction heating coil and the magnetic shield.

9. The gas thermal decomposition unit according to claim 1, characterized in that, The conductor and / or magnetic material comprises at least one selected from the group consisting of Fe, Cr, Ni, Mn, Zn, Co, Cu and Si.

10. The gas thermal decomposition unit according to claim 1, characterized in that, The magnetic material has a Curie point of over 300°C.

11. The gas thermal decomposition unit according to claim 1, characterized in that, At least one of the one or more cellular structures contains a catalyst.

12. A gas thermal decomposition apparatus, characterized in that, have: The gas thermal decomposition unit according to any one of claims 1 to 11; and The power supply circuit is connected to the induction heating coil. The structure is configured such that when the gas passes through the compartment, the honeycomb structure can be inductively heated using magnetic flux from the induction heating coil.

13. The gas thermal decomposition apparatus according to claim 12, characterized in that, The gas is a gas containing hydrogen atoms, and is configured to obtain hydrogen by thermally decomposing the gas by the gas thermal decomposition unit.

14. The gas thermal decomposition apparatus according to claim 13, characterized in that, The gas includes one or more of the following: hydrocarbons containing naphtha, hydroxides, ammonia, nitrogen oxides, hydrogen sulfide, and / or biological gases.

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