Hydrogen production device

Abstract

To provide a hydrogen production device that is capable of suppressing the fusion of catalysts with one another.SOLUTION: A hydrogen production device has a reactor that thermally decomposes a hydrocarbon gas, which is a raw material gas, using a catalyst, which is composed of metal fine particles, to produce hydrogen, wherein a fluidized bed of the catalyst is formed inside the reactor by introducing the raw material gas from the lower part of the reactor. The reactor is configured to be supplied with an activated catalyst.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a hydrogen production device. [Background technology]

[0002] Conventionally, there is known a technique for producing hydrogen by thermal decomposition of methane. For example, a hydrogen production device disclosed in Patent Document 1 has a reactor containing a catalyst. Methane is introduced into the reactor. The methane is decomposed into hydrogen and carbon by contacting with the catalyst inside the reactor. A mixed gas of hydrogen, which is the product gas, and unreacted methane is taken out of the reactor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-73411 A Summary of the Invention [Problem to be solved by the invention]

[0004] The catalyst is, for example, a metal such as iron. In this case, for example, when the hydrogen production device is started up, as the temperature of the reactor rises, there is a risk that the catalyst may fuse to each other. It is therefore necessary to prevent the catalyst from fusing to each other in the hydrogen production device. [Means for solving the problem]

[0005] A hydrogen production device according to one aspect of the present disclosure is a reactor for producing hydrogen by thermally decomposing a hydrocarbon gas as a raw material gas using a catalyst made of fine metal particles, and has a reactor into which a fluidized bed of the catalyst is formed by introducing the raw material gas from a lower portion. The reactor is configured so that the activated catalyst is supplied. Effect of the Invention

[0006] According to the hydrogen production device of the present invention, fusion between catalysts can be suppressed. [Brief description of the drawings]

[0007] [Figure 1] 1 is a configuration diagram of a first embodiment of a hydrogen production device. [Diagram 2] 1 is a block diagram showing an electrical configuration of a first embodiment of a hydrogen production device. [Diagram 3] FIG. 1 is a configuration diagram of a second embodiment of a hydrogen production device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] <First embodiment> A first embodiment of the hydrogen production device will be described below. As shown in FIG. 1, the hydrogen production device 10 has a pressure vessel 11 and a reactor 12. The pressure vessel 11 and the reactor 12 are each cylindrical with a circular cross-sectional shape and extend in the vertical direction. The inside of the pressure vessel 11 is kept at a predetermined pressure. The pressure is, for example, higher than atmospheric pressure. The reactor 12 is accommodated in the inside of the pressure vessel 11 in a non-contact state. The inner diameter of the reactor 12 may be the same over its entire length.

[0009] A disperser 13 is provided inside the reactor 12. The disperser 13 is, for example, in the form of a plate extending in a direction perpendicular to the axial direction of the reactor 12, and has a large number of holes. The holes penetrate the disperser 13 in the plate thickness direction. The disperser 13 is disposed at a position closer to the lower end of the reactor 12 than the central position of the reactor 12 in the axial direction. The disperser 13 divides the inside of the reactor 12 into two spaces, an upper space and an lower space. The upper space is the reaction chamber 12A, and the lower space is the wind chamber 12B. The reaction chamber 12A and the wind chamber 12B are in communication with each other via the holes in the disperser 13.

[0010] The catalyst 14 is deposited on the upper surface of the disperser 13. That is, the inside of the reaction chamber 12A is filled with the catalyst 14 up to a predetermined deposition height relative to the disperser 13. The upper surface is the surface of the disperser 13 on the reaction chamber 12A side. The catalyst 14 is, for example, iron (Fe) or fine solid particles mainly composed of iron, and is a metal particle. The catalyst 14 is heated by a heating device. The heating device is, for example, a heater or a jacket through which exhaust gas or steam flows.

[0011] An inlet pipe 15 is connected to the lower end of the reactor 12. The inlet pipe 15 penetrates the lower end of the pressure vessel 11. The inlet pipe 15 is a gas flow path for introducing a raw material gas into the inside of the reactor 12. The raw material gas is a hydrocarbon gas. The hydrocarbon gas is, for example, methane or a gas containing methane as a main component. The hydrocarbon gas is decomposed into hydrogen and carbon by contacting with the catalyst 14 inside the reactor 12. The carbon is in powder form.

[0012] An outlet pipe 16 is connected to the upper end of the reactor 12. The outlet pipe 16 penetrates the upper end of the pressure vessel 11. The outlet pipe 16 is a gas flow path for discharging the generated gas to the outside of the reactor 12. The generated gas is a gas generated inside the reactor 12, and is a mixed gas of hydrogen generated by thermal decomposition and unreacted hydrocarbons.

[0013] The raw material gas is supplied to the reaction chamber 12A via the air chamber 12B and the disperser 13. The raw material gas is rectified and diffused by the disperser 13. This allows the raw material gas to flow uniformly into the reaction chamber 12A from below. By blowing the raw material gas into the reaction chamber 12A from below, the catalyst 14, which is a solid particle, is suspended to a certain height and moves around vigorously. In other words, a fluidized bed, which is a layer of the catalyst 14 that moves around vigorously, is formed. By fluidizing the catalyst 14, a good mixture state of the catalyst 14 and the raw material gas is obtained. This promotes contact between the raw material gas and the catalyst 14. Therefore, the thermal decomposition reaction of the raw material gas by the catalyst 14 is promoted. The reactor 12 is a fluidized bed reaction vessel. The catalyst 14 is a fluidizing medium. The raw material gas is a fluidizing gas for fluidizing the catalyst 14.

[0014] <Reaction temperature> When hydrogen is produced, the inside of the reactor 12, and therefore the catalyst 14, are heated to a predetermined reaction temperature. The reaction temperature is a temperature at which the thermal decomposition reaction of the raw material gas by the catalyst 14 proceeds efficiently. The reaction temperature is set to a value within a predetermined temperature range depending on the product specifications, etc. The lower limit of the temperature range is set, for example, based on the starting temperature of thermal decomposition. The upper limit of the temperature range is set, for example, based on the heat resistance of the reactor 12.

[0015] If the reaction temperature is below the lower limit of the temperature range, the thermal decomposition reaction of the raw material gas may not proceed. This is because the reaction temperature is lower than the starting temperature of thermal decomposition, and the function of the catalyst 14 to decompose the raw material gas is not activated. The higher the reaction temperature, the more the thermal decomposition of the raw material gas proceeds. However, if the reaction temperature exceeds the upper limit of the temperature range, the reliability of the reactor 12 may not be ensured.

[0016] <Relationship between pressure of reactor 12 and amount of hydrogen generated> Next, the relationship between the pressure in the reactor 12 and the amount of hydrogen generated will be described. The pressure is the pressure inside the reactor 12. The pressure inside the reactor 12 depends on the pressure of the raw material gas supplied to the inside of the reactor 12. Here, the case where the raw material gas is methane will be described as an example.

[0017] The thermal decomposition reaction of methane is represented by the following formula (1). CH4→2H2+C …(1)

[0018] Furthermore, when the methane thermal decomposition is in a reaction equilibrium state, the following formula (2) holds regardless of the pressure in the reactor 12. P H2 2 / P CH4 = constant …(2) However, "P H2 2" is the partial pressure of hydrogen inside the reactor 12, and is a pressure that depends on the amount of hydrogen generated. CH4 " is the partial pressure of methane inside the reactor 12, which is a function of the pressure of methane fed to the reactor 12. " / " indicates division.

[0019] If the pressure in the reactor 12, i.e., the methane supply pressure, is quadrupled, it would appear at first glance that the methane partial pressure and hydrogen partial pressure would also quadruple. However, according to equation (2) above, the hydrogen partial pressure would double. In other words, the amount of hydrogen generated would be half that before the pressure increase.

[0020] In this way, when the pressure of the reactor 12, i.e., the supply pressure of methane, is increased, the amount of hydrogen generated in the reaction equilibrium becomes less than before the pressure was increased. In other words, the conversion rate of methane decreases. The conversion rate is the degree of the thermal decomposition reaction in the reactor 12, and indicates the conversion rate of the raw material gas, methane, to hydrogen. The pressure of the reactor 12, i.e., the supply pressure of methane, is set according to the product specifications, etc.

[0021] <Supply and discharge of catalyst 14> During operation of the hydrogen production device 10, the activity of the catalyst 14 gradually decreases as the thermal decomposition reaction progresses. Therefore, in order to maintain the decomposition rate of the raw material gas, it is necessary to supply new catalyst 14 to the reactor 12 and remove catalyst 14 with reduced activity from the reactor 12. Catalyst 14 with reduced activity includes deactivated catalyst 14. Deactivation refers to the loss of activity of the catalyst 14 and the inability to cause the thermal decomposition reaction of the raw material gas. The decomposition rate is the rate at which the raw material gas is decomposed in a certain period of time by the action of the catalyst 14.

[0022] The catalyst 14 with reduced activity has a smaller particle size and density than a new catalyst 14. The catalyst 14 with reduced activity has a terminal velocity equal to or lower than the superficial velocity due to the reduced particle size and particle density. Therefore, the catalyst 14 with reduced activity is basically discharged from the reactor 12 to the outside of the reactor 12 via the discharge pipe 16 together with the generated gas. The superficial velocity is the flow velocity of the raw material gas calculated assuming that the catalyst 14, which is a packed particle, does not exist in the reactor 12. The terminal velocity is the velocity when the drag force of the raw material gas that imparts an upward force to the particles and the gravity that imparts a downward force to the particles are balanced.

[0023] However, some of the catalyst 14 with reduced activity binds with carbon generated by thermal decomposition of the raw material gas and remains inside the reactor 12. This is because the particle size or particle density of the catalyst 14 with reduced activity increases as a result of binding with the generated carbon. For this reason, it is necessary to discharge the catalyst 14 with reduced activity to the outside of the reactor 12. Therefore, in this embodiment, the following configuration is adopted for the hydrogen production device 10.

[0024] <Configuration for Supplying Catalyst 14> As shown in FIG. 1, the hydrogen production apparatus 10 has a first supply device 21 for supplying new catalyst 14 to the reactor 12. The first supply device 21 is, for example, a lock hopper system. The first supply device 21 is provided on a first supply path 22A. The first supply path 22A is a path for supplying new catalyst 14 to the reactor 12, and is, for example, composed of piping. The first supply path 22A passes through the lower end of the pressure vessel 11 and is connected to the lower end of the reactor 12.

[0025] The first supply device 21 has a first receiving hopper 23, a first intermediate hopper 24, and a first supply hopper 25. The first supply hopper 25, the first intermediate hopper 24, and the first receiving hopper 23 are arranged in this order from the side closer to the reactor 12. The first intermediate hopper 24 is located between the first receiving hopper 23 and the first supply hopper 25. The hopper is a device for temporarily storing new catalyst 14.

[0026] The first receiving hopper 23 receives new catalyst 14 supplied from the outside, and temporarily stores the received new catalyst 14. The pressure in the first receiving hopper 23 is maintained at, for example, atmospheric pressure.

[0027] A pressure adjustment pipe is connected to the first intermediate hopper 24 via a valve. By introducing high-pressure gas into the first intermediate hopper 24 via the pipe, it is possible to increase the pressure inside the first intermediate hopper 24 to a pressure higher than atmospheric pressure. Also, by releasing the pressure inside the first intermediate hopper 24 via the pipe, it is possible to reduce the pressure inside the first intermediate hopper 24 to atmospheric pressure. The high-pressure gas is an inert gas such as nitrogen or argon.

[0028] The pressure in the first supply hopper 25 is always maintained higher than the pressure in the reactor 12. This is for example to suppress backflow of the catalyst 14. A first gate valve 26 is provided in the first supply path 22A between the first receiving hopper 23 and the first intermediate hopper 24. The first gate valve 26 opens and closes the first supply path 22A between the first receiving hopper 23 and the first intermediate hopper 24.

[0029] A second gate valve 27 is provided in the first supply path 22A between the first intermediate hopper 24 and the first supply hopper 25. The second gate valve 27 opens and closes the first supply path 22A between the first intermediate hopper 24 and the first supply hopper 25.

[0030] A third gate valve 28 and a first motor-operated valve 29 are provided in the first supply path 22A between the first supply hopper 25 and the reactor 12. The third gate valve 28 is provided in the first supply path 22A between the first supply hopper 25 and the first motor-operated valve 29. The third gate valve 28 opens and closes the first supply path 22A between the first supply hopper 25 and the first motor-operated valve 29.

[0031] The first motorized valve 29 is, for example, a rotary valve. The first motorized valve 29 has a motor and a rotor that is rotated by the drive of the motor. By controlling the rotation speed of the rotor, it is possible to control the amount of catalyst 14 discharged, which is a fine solid particle.

[0032] A second supply path 22B is connected to the first supply path 22A between the first motorized valve 29 and the reactor 12. The second supply path 22B is a path for supplying a carrier gas to the first supply path 22A between the first supply hopper 25 and the reactor 12, and is formed, for example, by piping. The carrier gas is a gas for carrying the catalyst 14 in the first supply path 22A between the first motorized valve 29 and the reactor 12 to the inside of the reactor 12, and is, for example, an inert gas such as nitrogen or argon. The catalyst 14 moves with the flow of the carrier gas.

[0033] <Configuration for discharging catalyst 14> As shown in Fig. 1, the hydrogen production apparatus 10 has an extraction device 31 for extracting the catalyst 14 with reduced activity from the reactor 12. The extraction device 31 is provided in an extraction path 32 for the catalyst 14. The extraction path 32 is a path for extracting the catalyst 14 with reduced activity to the outside of the reactor 12, and is formed of, for example, a pipe. A first end of the extraction path 32 is connected to a portion of the reactor 12 that corresponds to an upper portion of the fluidized bed of the catalyst 14. The upper portion is a portion of the fluidized bed on the side farther from the distributor 13 in the axial direction of the reactor 12.

[0034] The discharge device 31 has a cooler 33, a second motorized valve 34, and a discharge hopper 35. The cooler 33, the second motorized valve 34, and the discharge hopper 35 are arranged in this order from the side closer to the reactor 12. The second motorized valve 34 is located between the cooler 33 and the discharge hopper 35. The discharge hopper 35 is connected to a second end of the discharge path 32. The second end is an end of the discharge path 32 opposite to the first end.

[0035] The cooler 33 cools the catalyst 14 with reduced activity that is extracted from the reactor 12. The second motorized valve 34 is, for example, a rotary valve. The second motorized valve 34 has a motor and a rotor that is rotated by the drive of the motor. By controlling the rotation speed of the rotor, it is possible to control the discharge amount of the catalyst 14, which is fine solid particles. The extraction hopper 35 continuously extracts the catalyst 14 with reduced activity and temporarily stores the extracted catalyst 14.

[0036] <About fusion of catalyst 14> The catalyst 14 is, for example, iron or fine solid particles mainly composed of iron. For this reason, if only the catalyst 14 is contained in the reactor 12, the following concerns arise. That is, when the hydrogen production device 10 is started up, the catalyst 14 may fuse together with the temperature rise of the reactor 12, which may impede the flow of the catalyst 14. In addition, during operation of the hydrogen production device 10, the physical properties of the catalyst 14 may gradually change with the progress of the thermal decomposition reaction, which may change the stability of the flow of the catalyst 14. The physical properties of the catalyst 14 include the particle size and density of the catalyst 14.

[0037] Therefore, in this embodiment, the hydrogen production device 10 has the following configuration. That is, as shown in Fig. 1, a fluidizing material 17 is mixed into the catalyst 14. The fluidizing material 17 is for increasing the fluidity of the catalyst 14. The fluidizing material 17 is fine solid particles, such as inert particles of silicon or the like.

[0038] <Configuration for Supplying Flowable Material 17> As shown in Fig. 1, the hydrogen production apparatus 10 has a second supply device 41 for supplying the fluid material 17 to the reactor 12. The second supply device 41 is provided on a third supply path 42A. The third supply path 42A is a path for supplying the fluid material 17 to the reactor 12, and is formed of, for example, a pipe. The third supply path 42A passes through the lower end of the pressure vessel 11 and is connected to the lower end of the reactor 12.

[0039] The second supply device 41 is, for example, a lock hopper system, and has a configuration similar to that of the first supply device 21. That is, the second supply device 41 has a second receiving hopper 43, a second intermediate hopper 44, and a second supply hopper 45. From the side closer to the reactor 12, the second supply hopper 45, the second intermediate hopper 44, and the second receiving hopper 43 are arranged in this order. The second intermediate hopper 44 is located between the second receiving hopper 43 and the second supply hopper 45.

[0040] The second receiving hopper 43 receives the fluid material 17 supplied from the outside, and temporarily stores the received fluid material 17. The pressure in the second receiving hopper 43 is maintained at, for example, atmospheric pressure.

[0041] A pressure adjustment pipe is connected to the second intermediate hopper 44 via a valve. By introducing high-pressure gas into the second intermediate hopper 44 via the pipe, it is possible to increase the pressure inside the second intermediate hopper 44 to a pressure higher than atmospheric pressure. Also, by releasing the pressure inside the second intermediate hopper 44 via the pipe, it is possible to reduce the pressure inside the second intermediate hopper 44 to atmospheric pressure. The high-pressure gas is an inert gas such as nitrogen or argon.

[0042] The pressure of the second supply hopper 45 is always maintained higher than the pressure of the reactor 12. This is for the purpose of, for example, suppressing the backflow of the fluid material 17. A fourth gate valve 46 is provided in the third supply path 42A between the second receiving hopper 43 and the second intermediate hopper 44. The fourth gate valve 46 opens and closes the third supply path 42A between the second receiving hopper 43 and the second intermediate hopper 44.

[0043] A fifth gate valve 47 is provided in the third supply path 42A between the second intermediate hopper 44 and the second supply hopper 45. The fifth gate valve 47 opens and closes the third supply path 42A between the second intermediate hopper 44 and the second supply hopper 45.

[0044] A sixth gate valve 48 and a third motor-operated valve 49 are provided in the third supply path 42A between the second supply hopper 45 and the reactor 12. The sixth gate valve 48 is provided in the third supply path 42A between the second supply hopper 45 and the third motor-operated valve 49. The sixth gate valve 48 opens and closes the third supply path 42A between the second supply hopper 45 and the third motor-operated valve 49.

[0045] The third motorized valve 49 is, for example, a rotary valve. The third motorized valve 49 has a motor and a rotor that is rotated by the drive of the motor. By controlling the rotation speed of the rotor, it is possible to control the amount of catalyst 14 discharged, which is a fine solid particle.

[0046] A fourth supply path 42B branched from the second supply path 22B is connected to the third supply path 42A between the third motorized valve 49 and the reactor 12. The fourth supply path 42B is a path for supplying a carrier gas to the third supply path 42A between the third motorized valve 49 and the reactor 12, and is, for example, composed of a pipe. The carrier gas is a gas for carrying the fluid material 17 in the third supply path 42A between the third motorized valve 49 and the reactor 12 to the inside of the reactor 12, and is, for example, an inert gas such as nitrogen or argon. The fluid material 17 moves with the flow of the carrier gas.

[0047] <Electrical configuration of the hydrogen production device 10> Next, the electrical configuration of the hydrogen production device 10 will be described. As shown in FIG. 2, the hydrogen production device 10 includes a first temperature sensor 51, a second temperature sensor 52, a differential pressure sensor 53, a concentration sensor 54, and a control device 55.

[0048] The first temperature sensor 51 is provided in the reactor 12. The first temperature sensor 51 detects a first temperature T1 of the fluidized bed of the catalyst 14. The first temperature T1 is the temperature of an upper part of the fluidized bed.

[0049] The second temperature sensor 52 is provided in the reactor 12. The second temperature sensor 52 detects a second temperature T2 of the fluidized bed of the catalyst 14. The second temperature T2 is the temperature of the lower part of the fluidized bed.

[0050] The differential pressure sensor 53 is provided in the reactor 12. The differential pressure sensor 53 detects a pressure difference ΔP between an upper part of the reaction chamber 12A and a lower part of the reaction chamber 12A. The upper part of the reaction chamber 12A is an empty part of the reactor 12 that is outside the fluidized bed of the catalyst 14. The lower part of the reaction chamber 12A is a part of the reactor 12 that corresponds to the fluidized bed of the catalyst 14, for example, a part that corresponds directly above the disperser 13.

[0051] The concentration sensor 54 is provided in the outlet pipe 16. The concentration sensor 54 detects the concentration M of hydrogen in the product gas generated by the thermal decomposition of the raw material gas. The control device 55 has a processing circuit including any one of the following three components A1, A2, and A3.

[0052] A1. One or more processors that operate according to a computer program that is software. The processor includes a CPU (central processing unit) and memory.

[0053] A2. One or more dedicated hardware circuits, such as an application specific integrated circuit (ASIC), that perform at least some of the processes. The ASIC includes a CPU and memory.

[0054] A3. A hardware circuit that combines configurations A1 and A2. A memory is a medium that can be read by a computer (here, the CPU) and stores a program that describes processes or instructions for the computer. Memory includes RAM (random access memory) and ROM (read only memory). The CPU executes various controls by executing the programs stored in the memory at a set calculation cycle.

[0055] The control device 55 controls the operations of the first supply device 21, the unloading device 31, and the second supply device 41. The control device 55 controls the supply of new catalyst 14 to the reactor 12 through the first supply device 21 based on, for example, the detection results of various sensors (51-54). The control device 55 controls the unloading of the catalyst 14 with reduced activity from the reactor 12 through the unloading device 31 based on, for example, the detection results of various sensors (51-54). The control device 55 controls the supply of the flowable material 17 to the reactor 12 through the second supply device 41.

[0056] <Catalyst 14 Supply Processing> When supplying catalyst 14 to reactor 12, control device 55 controls first supply device 21 as follows. That is, control device 55 first opens first gate valve 26. As a result, new catalyst 14 stored in first receiving hopper 23 moves by gravity to first intermediate hopper 24. After moving a predetermined amount of catalyst 14, control device 55 closes first gate valve 26.

[0057] Next, the control device 55 introduces high-pressure gas into the first intermediate hopper 24 through a pressure adjustment pipe. This increases the pressure inside the first intermediate hopper 24 to the same level as the pressure of the first supply hopper 25. The pressure of the first supply hopper 25 is maintained at a pressure equal to or higher than the pressure of the reactor 12. Thereafter, the control device 55 opens the second gate valve 27. This causes the catalyst 14 in the first intermediate hopper 24 to be discharged to the first supply hopper 25.

[0058] After the control device 55 has completed discharging the catalyst 14 to the first supply hopper 25, it closes the second gate valve 27 and releases the gas in the first intermediate hopper 24 through a pressure adjustment pipe, thereby reducing the pressure inside the first intermediate hopper 24 to atmospheric pressure. This enables the first intermediate hopper 24 to receive the catalyst 14 from the first receiving hopper 23 again.

[0059] Next, the control device 55 opens the third gate valve 28. As a result, the catalyst 14 in the first supply hopper 25 is discharged to the first electric valve 29. The control device 55 controls the first motorized valve 29 so that a fixed amount of catalyst 14 is continuously delivered from the first motorized valve 29. The catalyst 14 delivered from the first motorized valve 29 is supplied to the reactor 12 by air current transport. That is, the catalyst 14 delivered from the first motorized valve 29 joins with the carrier gas at the connection portion between the first supply path 22A and the second supply path 22B, and is supplied to the reactor 12 together with the carrier gas. The control device 55 opens the first gate valve 26 during the period in which the catalyst 14 is being supplied to the reactor 12. The first intermediate hopper 24 receives the catalyst 14 from the first receiving hopper 23 again.

[0060] When the amount of catalyst 14 in first supply hopper 25 decreases to near the lower limit, control device 55 closes first gate valve 26 and introduces high-pressure gas into first intermediate hopper 24 through pressure adjustment piping. As a result, the pressure inside first intermediate hopper 24 is increased to approximately the same as the pressure of first supply hopper 25. Thereafter, control device 55 opens second gate valve 27. As a result, catalyst 14 in first intermediate hopper 24 is dispensed into first supply hopper 25.

[0061] After the control device 55 has completed dispensing of the catalyst 14 to the first supply hopper 25, it closes the second gate valve 27 and releases the gas in the first intermediate hopper 24 through a pressure adjustment pipe, thereby reducing the pressure inside the first intermediate hopper 24 to atmospheric pressure. When the pressure inside the first intermediate hopper 24 becomes approximately the same as atmospheric pressure, i.e., the pressure of the first receiving hopper 23, the control device 55 opens the first gate valve 26. This allows the first intermediate hopper 24 to receive the catalyst 14 from the first receiving hopper 23 again.

[0062] The control device 55 repeatedly executes the above process to continuously supply the catalyst 14 to the reactor 12. The catalyst 14 is supplied to the reactor 12 by being transported by the carrier gas.

[0063] <Removal of catalyst 14 from reactor 12> When the catalyst 14 is discharged from the reactor 12, the control device 55 controls the discharge device 31 as follows. That is, the control device 55 operates the cooler 33 and the second motor-driven valve 34. As a result, the catalyst 14 with reduced activity is discharged from the reactor 12. The discharged catalyst 14 is cooled by the cooler 33. The cooled catalyst 14 is sent to the discharge hopper 35 by the second motor-driven valve 34.

[0064] The control device 55 may execute the extraction process of the catalyst 14 and the supply process of the catalyst 14 at the same timing. In this case, the discharge amount of the catalyst 14 may be the same as the supply amount of the catalyst 14 by the first supply device 21, for example. The discharge speed of the catalyst 14 may be the same as the supply speed of the catalyst 14 by the first supply device 21. In this way, the fluctuation in the height of the catalyst layer becomes gentle and it becomes easier to maintain a uniform catalyst layer. Depending on the product specifications, the control device 55 may execute the extraction process of the catalyst 14 and the supply process of the catalyst 14 at different timings.

[0065] <Supply processing of fluid material 17> When the control device 55 supplies the fluid material 17 to the reactor 12, it controls the second supply device 41 in the same manner as the first supply device 21. This allows the fluid material 17 to be continuously supplied to the reactor 12. The fluid material 17 is supplied to the reactor 12 by being air-transported by the carrier gas. The supply amount of the fluid material 17 is set to an appropriate amount according to the product specifications, etc.

[0066] At least at the start-up of the hydrogen production device 10, the control device 55 supplies the fluid material 17 to the inside of the reactor 12 before performing the activation process of the catalyst 14 contained in the reactor 12. The control device 55 may perform the supply process of the fluid material 17 at the same timing as the supply process of the catalyst 14 or the extraction process of the catalyst 14, for example. Depending on the product specifications, the control device 55 may perform the supply process of the fluid material 17 at a different timing from the supply process of the catalyst 14 or the extraction process of the catalyst 14. For example, the fluid material 17 may be supplied to the reactor 12 after the catalyst 14 is supplied to the reactor 12 or the catalyst 14 is extracted from the reactor 12. Alternatively, the feed gas may be used as the carrier gas, in which case the fresh catalyst 14 and fluidizing material 17 are fed to the reactor 12 by the flow of the feed gas.

[0067] <Advantages of the First Embodiment> The first embodiment provides the following advantages.

[0068] (1-1) By mixing the fluidizing material 17 with the catalyst 14, it is possible to prevent the catalyst 14 from fusing together inside the reactor 12. Therefore, the catalyst 14 flows stably. In addition, it is possible to ensure the stability of the flow of the catalyst 14.

[0069] (1-2) The fluidizing material 17 is supplied to the reactor 12, for example, in response to the supply of new catalyst 14 or the discharge of inactive catalyst 14. Fusion between catalysts 14 is suppressed. (1-3) The pressure in the reactor 12 is higher than atmospheric pressure. The second supply device 41 pressurizes the fluid material 17 to a pressure equal to or higher than the pressure in the reactor 12 and continuously conveys it by airflow. With this configuration, the fluid material 17 can be supplied to the reactor 12 by airflow conveyance.

[0070] (1-4) The pressure in the reactor 12 is higher than atmospheric pressure. The first supply device 21 pressurizes new catalyst 14 to a pressure equal to or higher than the pressure in the reactor 12 and continuously transports it by airflow. With this configuration, new catalyst 14 can be supplied to the reactor 12 by airflow transport.

[0071] (1-5) The catalyst 14 with reduced activity is discharged from the reactor 12 by the discharge device 31. This makes it possible to prevent carbon generated by thermal decomposition of the raw material gas from binding to the catalyst 14 with reduced activity and remaining inside the reactor 12.

[0072] <Second embodiment> Next, a second embodiment of the hydrogen production device will be described. This embodiment differs from the first embodiment in the configuration of the first supply device 21 that supplies new catalyst 14 to the reactor 12. Therefore, the same members and configurations as those in the first embodiment are given the same reference numerals, and detailed descriptions thereof will be omitted.

[0073] The catalyst 14 before activation treatment needs to be activated through an activation treatment. The activation treatment is a treatment in which the catalyst 14 before activation is heated, for example, at a predetermined activation treatment temperature for a predetermined time. Activation of the catalyst 14 causes a thermal decomposition reaction of the raw material gas. Heating can be performed by contacting the catalyst 14 with a heated gas or by using a burner as long as it is possible to heat the catalyst 14 before activation. The gas is, for example, the raw material gas or nitrogen.

[0074] 3, the first supply device 21 has a rotary kiln 61 and a hopper 62. The hopper 62 and the rotary kiln 61 are arranged in this order from the side closer to the reactor 12. The hopper 62 has a configuration similar to that of the first intermediate hopper 24 or the first supply hopper 25, for example.

[0075] The rotary kiln 61 is an activation device that activates the catalyst 14 while stirring it before activation. The rotary kiln 61 has an introduction section 61A, a rotor 61B, and a discharge section 61C. The rotor 61B is hollow and cylindrical. The rotor 61B can rotate around its axis by, for example, being applied with a rotational force of a motor (not shown). The introduction section 61A is connected to a first end of the rotor 61B. The inside of the introduction section 61A and the inside of the rotor 61B are in communication with each other. The second end of the rotor 61B is connected to the discharge section 61C. The second end is an end of the rotor 61B opposite to the first end. The inside of the rotor 61B and the inside of the discharge section 61C are in communication with each other. The discharge section 61C is connected to the reactor 12 via an introduction pipe 15. The rotor 61B is slightly inclined so that the discharge portion 61C is lower than the introduction portion 61A.

[0076] The introduction section 61A introduces the raw material gas supplied through a gas flow path (not shown) into the inside of the rotor 61B. The raw material gas is a hydrocarbon gas. The introduction section 61A also introduces the catalyst 14 before activation treatment, supplied through a supply path (not shown) for the catalyst 14, into the inside of the rotor 61B. The catalyst 14 introduced into the inside of the rotor 61B is heated by a heating device (not shown) while being stirred by the rotation of the rotor 61B. The catalyst 14 is activated by contacting the raw material gas at a predetermined activation treatment temperature for a predetermined time. The catalyst 14 inside the rotor 61B moves from the first end to the second end of the rotor 61B as the rotor 61B rotates, and eventually reaches the discharge section 61C. The catalyst 14 in the discharge section 61C is supplied to the reactor 12 through a hopper 62. The raw material gas introduced into the inside of the rotor 61B is supplied to the reactor 12 through an introduction pipe 15.

[0077] This embodiment can be applied to the first embodiment. That is, the discharge unit 61C may be connected to, for example, the first receiving hopper 23 or the first intermediate hopper 24. In this case, the catalyst 14 in the discharge unit 61C is supplied to the first receiving hopper 23 or the first intermediate hopper 24. When the discharge unit 61C is connected to the first intermediate hopper 24, the hydrogen production device 10 may have a configuration in which the first receiving hopper 23 is omitted.

[0078] In addition, the rotary kiln 61 does not have to be a part of the first supply device 21. That is, the rotary kiln 61 may be provided independently of the first supply device 21. The reactor 12 only needs to be configured so that the catalyst 14 activated by the rotary kiln 61 is supplied thereto.

[0079] <Advantages of the second embodiment> The second embodiment provides the following advantages. (2-1) The catalyst 14 is supplied to the reactor 12 in an already activated state. Since the activated catalyst 14 is supplied to the reactor 12, there is no need to perform an activation process for the catalyst 14 inside the reactor 12. Therefore, for example, when the hydrogen production device 10 is started up, the catalysts 14 are prevented from fusing together as the temperature of the reactor 12 rises. In addition, the stability of the flow of the catalyst 14 can be ensured.

[0080] (2-2) The catalyst 14 is activated by being heated while being stirred in the rotary kiln 61. This prevents the catalyst 14 from fusing together during the activation process. Therefore, the activated catalyst 14 can be supplied to the reactor 12 in an appropriate state.

[0081] (2-3) In addition, by supplying the activated catalyst 14 to the reactor 12, the amount of catalyst 14 held inside the reactor 12 can be reduced. This is for the following reason. That is, the catalyst 14 becomes inactivated after a certain life. It is preferable to discharge the deactivated catalyst 14 from the reactor 12, while holding the non-deactivated catalyst 14 inside the reactor 12. In addition, while continuously feeding the catalyst 14 into the reactor 12 and continuously discharging the catalyst 14 from the reactor 12, the amount of catalyst 14 inside the reactor 12 should be controlled to a certain amount. For this reason, the amount of catalyst 14 fed into the reactor 12 is close to the amount of catalyst 14 discharged from the reactor 12. In other words, the amount of catalyst 14 held inside the reactor 12 is the same in the case where a small amount of catalyst 14 is fed into the reactor 12 and a small amount of catalyst 14 is discharged from the reactor 12, and in the case where a large amount of catalyst 14 is fed into the reactor 12 and a large amount of catalyst 14 is discharged from the reactor 12. On the other hand, the time that a particular catalyst 14 remains inside the reactor 12 depends on the amount of catalyst 14 put into the reactor 12. For example, when a large amount of catalyst 14 is put into the reactor 12 and a large amount of catalyst 14 is discharged from the reactor 12, the time that the catalyst 14 remains inside the reactor 12 becomes shorter. That is, in the case of a catalyst 14 that has not been activated in advance, the time until deactivation, i.e., the life, becomes longer, and a large amount of catalyst 14 needs to be held inside the reactor 12 in proportion to the longer life. In this regard, by pretreating the catalyst 14, the amount of catalyst 14 packed inside the reactor 12 can be reduced and the life of the catalyst 14 can be used up. The pretreatment is an activation treatment.

[0082] <Other embodiments> Each embodiment may be modified as follows. In the first and second embodiments, the pressure in the reactor 12 may be maintained at atmospheric pressure. In this case, the hydrogen production device 10 may have a configuration in which the pressure vessel 11 is omitted. The lower the pressure in the reactor 12, the higher the methane conversion rate.

[0083] In the first embodiment, as shown by the two-dot chain line arrow in FIG. 1, when the pressure of the reactor 12 and the pressure of the first supply hopper 25 are equal, the catalyst 14 may be supplied to the reactor 12 by gravity. When the pressure of the reactor 12 and the pressure of the second supply hopper 45 are equal, the fluidized material 17 may be supplied to the reactor 12 by gravity. The pressure may be, for example, atmospheric pressure. In this case, the first supply hopper 25 is connected to the upper part of the reactor 12 via, for example, the third gate valve 28 and the first electric valve 29. The second supply hopper 45 is connected to the upper part of the reactor 12 via the sixth gate valve 48 and the third electric valve 49. The same applies to the second embodiment.

[0084] In the first and second embodiments, the catalyst 14 may be a metal such as nickel or cobalt, or may be fine metal particles containing these metals as the main component. As used herein, the term "cylinder" or "cylindrical" may refer to any structure having a peripheral wall. For example, but not limited to, the term "cylinder" or "cylindrical" may refer to any structure having a cross-sectional shape that is circular, elliptical, and polygonal with sharp or rounded corners. In this specification, whether a catalyst 14 is new or not does not depend on whether it has been pretreated, but on whether it has already contributed to the reaction as a catalyst 14. A new catalyst 14 is a catalyst 14 that has not yet contributed to the reaction.

[0085] <Additional Notes> The hydrogen production device according to the present embodiment can be understood, for example, as follows. 1. A hydrogen production device (10) according to a first embodiment has a reactor (12) for producing hydrogen by thermally decomposing a hydrocarbon gas, which is a raw material gas, using a catalyst (14) which is fine metal particles, and has a reactor (12) into which a fluidized bed of the catalyst (14) is formed by introducing the raw material gas from the bottom. The reactor (12) is configured so that the activated catalyst (14) is supplied.

[0086] In the hydrogen production device according to the first aspect, since an activated catalyst is supplied to the reactor, there is no need to perform an activation process for the catalyst inside the reactor. Therefore, for example, when starting up the hydrogen production device, fusion of the catalysts due to the rise in temperature of the reactor is suppressed.

[0087] 2. The hydrogen production apparatus (10) according to the second aspect is the hydrogen production apparatus (10) according to the first aspect, and further comprises a supply device (21) configured to supply the activated catalyst (14) to the reactor (12), the supply device (21) including an activating device (61) configured to activate the catalyst (14) before activation by heating it while stirring it, and the supply device (21) is configured to supply the catalyst (14) activated by the activating device (61) to the reactor (12).

[0088] According to the hydrogen production device of the second aspect, the catalyst is activated by being heated while being stirred by the activation device. Therefore, it is possible to prevent the catalyst from fusing together during the activation process. Therefore, the activated catalyst can be supplied to the reactor in an appropriate state.

[0089] 3. The hydrogen production apparatus (10) according to the third aspect is the hydrogen production apparatus (10) according to the second aspect, wherein the pressure in the reactor (12) is higher than atmospheric pressure, and the supply device (21) is configured to pressurize the catalyst (14) activated by the activator (61) to a pressure equal to or higher than the pressure in the reactor (12) and continuously transport it in a gas flow. According to the hydrogen production device of the third aspect, the fluid material can be supplied to the reactor by the supply device through pneumatic transport.

[0090] 4. The hydrogen production apparatus (10) according to a fourth aspect is the hydrogen production apparatus (10) according to the third aspect, wherein the carrier gas used for transporting the gas flow is the raw material gas. According to the hydrogen production device of the fourth aspect, the activated catalyst can be supplied to the reactor by utilizing the flow of the raw material gas.

[0091] 5. The hydrogen production apparatus (10) according to the fifth aspect is the hydrogen production apparatus (10) according to the first aspect, wherein the activated catalyst (14) is supplied to the reactor (12) by gravity.

[0092] According to the hydrogen production device of the fifth aspect, the activated catalyst can be supplied to the reactor by gravity. [Explanation of symbols]

[0093] 10...Hydrogen production equipment 12...Reactor 14...Catalyst 21...First supply device (supply device) 61...Rotary kiln (activation device)

Claims

1. A hydrogen production apparatus having a reactor for producing hydrogen by thermally decomposing a hydrocarbon gas as a raw material gas using a catalyst of fine metal particles, the reactor having a fluidized bed of the catalyst formed inside by introducing the raw material gas from a lower part of the reactor, The hydrogen production device is configured so that the reactor is supplied with the activated catalyst.

2. a feeder configured to feed the activated catalyst to the reactor; The supply device includes an activation device configured to activate the pre-activated catalyst by heating while stirring, The hydrogen production apparatus according to claim 1 , wherein the supply device is configured to supply the catalyst activated by the activation device to the reactor.

3. The reactor pressure is higher than atmospheric pressure, 3. The hydrogen production apparatus according to claim 2, wherein the supply device is configured to pressurize the catalyst activated by the activator to a pressure equal to or higher than a pressure of the reactor and continuously transport the catalyst in a gas flow.

4. 4. The hydrogen production device according to claim 3, wherein a carrier gas used for the gas flow transport is the raw material gas.

5. The hydrogen production device according to claim 1 , wherein the activated catalyst is supplied to the reactor by gravity.

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