Power generation system and power generation method

Abstract

To provide a technology capable of suppressing temperature rise of a reactor with a simple configuration.SOLUTION: The power generation system is mounted on a movable body that moves by power. The power generation system includes: a raw liquid container for preparing an aqueous solution containing tetrahydroborate; a reactor having a catalyst for reacting the aqueous solution prepared by the raw liquid container to generate a hydrogen and a metaborate aqueous solution; a power converter for reacting hydrogen and oxygen generated by the reactor to acquire power; an electric motor to be driven by the power; a propeller to be driven by the electric motor; a recovery container for storing the metaborate aqueous solution generated by the reactor; a flow channel from the raw liquid container to the reactor; and a switching part for switching the flow channel from the recovery container to the reactor.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a power generation system and a power generation method.

Background Art

[0002] Patent Document 1 discloses a power generation system for a submarine. In this power generation system, an aqueous solution such as zinc borohydride is introduced into a reactor having a catalyst to generate hydrogen by catalysis. The generated hydrogen reacts with oxygen in a fuel cell to be converted into DC power. The reaction heat generated during hydrogen generation is absorbed to the outside through a heat exchanger.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] Since the submarine described in Patent Document 1 requires a heat exchanger, the configuration may become complicated. The present disclosure provides a technique capable of suppressing the temperature rise of a reactor with a simple configuration.

Means for Solving the Problems

[0005] A power generation system according to an aspect of the present disclosure includes a stock solution container, a reactor, a power converter, a recovery container, and a switching unit. The stock solution container prepares an aqueous solution containing tetrahydroborate. The reactor has a catalyst that reacts the aqueous solution prepared by the stock solution container to generate hydrogen and an aqueous metaborate solution. The power converter obtains power by reacting hydrogen generated by the reactor with oxygen. The recovery container stores the aqueous metaborate solution generated by the reactor. The switching unit switches between a flow path from the stock solution container to the reactor and a flow path from the recovery container to the reactor.

Effects of the Invention

[0006] This disclosure provides a technology that can suppress the temperature rise of a reactor with a simple configuration. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic diagram showing an example of a power generation system according to the embodiment. [Figure 2] (A) is a side view showing an example of a vehicle equipped with the power generation system according to the embodiment. (B) is a top view showing an example of a vehicle equipped with the power generation system according to the embodiment. [Figure 3] (A) is a side view showing an example of a ship equipped with the power generation system according to the embodiment. (B) is a top view showing an example of a ship equipped with the power generation system according to the embodiment. [Figure 4] (A) is a side view showing an example of an aircraft equipped with the power generation system according to the embodiment. (B) is a top view showing an example of an aircraft equipped with the power generation system according to the embodiment. [Figure 5] This is a flowchart showing an example of a propulsion method according to the embodiment. [Figure 6] This flowchart shows an example of a cooling method. [Modes for carrying out the invention]

[0008] Embodiments of the present disclosure will be described below with reference to the drawings. In the following description, the same or equivalent elements will be denoted by the same reference numeral, and redundant descriptions will not be repeated. The dimensional ratios in the drawings do not necessarily correspond to those in the description. The terms "top," "bottom," "left," and "right" are based on the illustrated state and are for convenience only.

[0009] In the following explanation, tetrahydroborate includes hydrides corresponding to the borates exemplified below. For example, when metaborate is used as the borate, it includes NaBH4 (sodium borohydride), KBH4, LiBH4, Ca(BH4)2, Mg(BH4)2, etc.

[0010] Examples of borates include metaborates, tetraborates, and pentaborates. Examples of metaborates include NaBO2, KBO2, LiBO2, Ca(BO2)2, and Mg(BO2)2. Examples of tetraborates include Na2B4O7, Na2O·2BO3, K2O·B2O3, Li2B4O7, and Mg3B4O9. Examples of pentaborates include NaB5O8, Na2O·5B2O3, KB5O8, K2O·5B2O9, and LiB5O8. In addition, there are naturally occurring borate minerals such as Na2B4O7·10H2O, Na2B4O7·4H2O, and Ca2B6O 11 ·5H2O, CaNaB5O9 ·6H2O, Mg7Cl2B 17 O 30 Other materials can also be used. From the viewpoint of availability, cost of acquisition, chemical stability, ease of hydrogen desorption, and hydrogen storage density, sodium metaborate can be used as the borate.

[0011] Figure 1 is a schematic diagram showing an example of a power generation system 1 according to an embodiment. The power generation system 1 shown in Figure 1 is mounted on a mobile body that moves using electricity. As shown in Figure 1, the power generation system 1 comprises a raw material container 10, a water container 11, a concentrate container 20, a reactor 30, a buffer container 31, a recovery container 32, a power converter 40, and a control unit 70.

[0012] The raw material container 10 stores tetrahydroborate. The raw material container 10 is connected to the stock solution container 20 by piping. The tetrahydroborate stored in the raw material container 10 is supplied to the stock solution container 20 via piping. The raw material container 10 may also be connected to the piping via a first supply device 10a. The first supply device 10a supplies a fixed amount of tetrahydroborate from the raw material container 10 to the stock solution container 20 via piping. The amount of tetrahydroborate supplied by the first supply device 10a is controlled by the control unit 70. The first supply device 10a is, for example, a screw feeder. The first supply device 10a may also be a vibrating feeder.

[0013] The water container 11 stores water. The water container 11 is connected to the concentrate container 20 by piping. The water stored in the water container 11 is supplied to the concentrate container 20 via the piping. A second supply device 11a may be provided in the piping between the water container 11 and the concentrate container 20. The second supply device 11a supplies a fixed amount of water from the water container 11 to the concentrate container 20. The amount of water supplied by the second supply device 11a is controlled by the control unit 70. The second supply device 11a is, for example, a pump.

[0014] The stock solution container 20 prepares an aqueous solution containing tetrahydroborate. In the stock solution container 20, the tetrahydroborate supplied from the raw material container 10 and the water supplied from the water container 11 are mixed. A stirrer may be provided inside the stock solution container 20. Hereinafter, the aqueous solution containing tetrahydroborate prepared in the stock solution container 20 may be simply referred to as "aqueous solution." The concentration of tetrahydroborate in the aqueous solution is adjusted to a predetermined concentration.

[0015] The stock solution container 20 is connected to the reactor 30 by piping. This piping constitutes a first flow path L1 from the stock solution container 20 to the reactor 30. The aqueous solution stored in the stock solution container 20 is supplied to the reactor 30 via the piping. A third supply device 20a may be provided in the piping between the stock solution container 20 and the reactor 30. The third supply device 20a supplies a fixed amount of aqueous solution from the stock solution container 20 to the reactor 30. The amount of aqueous solution supplied by the third supply device 20a is controlled by the control unit 70. The third supply device 20a is, for example, a pump.

[0016] The reactor 30 has a catalyst 30a that reacts an aqueous solution prepared by the stock solution container 20 to produce hydrogen and an aqueous solution of metal metaborate. For example, the catalyst 30a is disposed inside the reactor 30. The catalyst 30a is, as an example, a mesh catalyst. The material of the catalyst 30a is, as an example, Raney nickel. Inside the reactor 30, the aqueous solution supplied from the stock solution container 20 reacts with the catalyst 30a to produce hydrogen and an aqueous solution of metal metaborate. A nozzle 30b may be provided inside the reactor 30. The nozzle 30b sprays the aqueous solution supplied from the stock solution container 20 toward the mesh catalyst disposed inside the reactor 30.

[0017] The aqueous solution that has contacted the catalyst is hydrolyzed as shown by the following formula (1), and hydrogen and an aqueous solution of metal metaborate are produced. The amounts of the produced hydrogen and aqueous solution of metal metaborate are adjusted by the amount of the aqueous solution supplied by the third supply device 20a. The amounts of the produced hydrogen and aqueous solution of metal metaborate are controlled by the control unit 70. NaBH 4(aq) +2H2O→NaBO 2(aq) +4H2+217kJ (1)

[0018] The buffer container 31 is provided below the reactor 30. The reactor 30 and the buffer container 31 are connected such that the internal space of the reactor 30 and the internal space of the buffer container 31 define one space. The hydrogen and the aqueous solution of metal metaborate produced in the reactor 30 are stored in the buffer container 31. A pressure sensor and a water amount sensor may be provided in the buffer container 31.

[0019] The buffer container 31 is connected to the recovery container 32 by a pipe. The aqueous metaborate solution stored in the buffer container 31 is supplied to the recovery container 32 through the pipe. A liquid regulating valve may be provided in the pipe between the buffer container 31 and the recovery container 32. The liquid regulating valve is, for example, a solenoid valve and is controlled by the control unit 70. The control unit 70 controls the opening and closing of the liquid regulating valve according to the measured value of the water volume sensor provided in the buffer container 31, thereby controlling the amount of the aqueous metaborate solution supplied from the buffer container 31 to the recovery container 32.

[0020] The buffer container 31 is connected to the power converter 40 by a pipe. The hydrogen stored in the buffer container 31 is supplied to the power converter 40 through the pipe. A gas regulating valve 31a may be provided in the pipe between the buffer container 31 and the power converter 40. The gas regulating valve 31a is, for example, a solenoid valve and is controlled by the control unit 70. The control unit 70 controls the opening and closing of the gas regulating valve 31a according to the measured value of the pressure sensor provided in the buffer container 31, thereby controlling the amount of hydrogen supplied from the buffer container 31 to the power converter 40.

[0021] The power converter 40 obtains power by reacting hydrogen and oxygen generated by the reactor 30. The power converter 40 is, for example, a fuel cell. The control unit 70 may control the opening and closing of the gas regulating valve 31a according to the electromotive force of the power converter 40, thereby controlling the amount of hydrogen supplied from the buffer container 31 to the power converter 40. The power converter 40 supplies power to the motor 60 (see FIGS. 2 to 4 described later).

[0022] The aqueous solution containing tetrahydroborate prepared in the stock solution container 20 may contain metaborate. For example, the aqueous metaborate solution may be supplied from the recovery container 32 in which the aqueous metaborate solution is stored to the water container 11 in which water is stored.

[0023] The power generation system 1 may include a dehumidifier 31b that removes moisture contained in the hydrogen produced in the reactor 30. The dehumidifier 31b is located, for example, in the piping through which the hydrogen from the buffer container 31 flows toward the power converter 40. The dehumidifier 31b is, for example, a valve containing silica gel.

[0024] The recovery container 32 stores the metaborate aqueous solution. The recovery container 32 is connected to the reactor 30 by piping. This piping constitutes a second flow path L2 from the recovery container 32 to the reactor 30. The metaborate aqueous solution stored in the recovery container 32 is supplied to the reactor 30 via the piping as cooling water for spraying. A fourth supply device 32a may be provided in the piping between the recovery container 32 and the reactor 30. The fourth supply device 32a supplies a fixed amount of metaborate aqueous solution from the recovery container 32 to the reactor 30. The amount of metaborate aqueous solution supplied by the fourth supply device 32a is controlled by the control unit 70. The fourth supply device 32a is, for example, a pump.

[0025] The first flow path L1 and the second flow path L2 are connected in a switchable manner by a switching unit 50. The switching unit 50 may be a three-way valve, or it may be a structure in which on / off valves are provided for both the first flow path L1 and the second flow path L2. When the first flow path L1 is open and the second flow path L2 is closed, an aqueous solution containing tetrahydroborate is supplied to the reactor 30 and sprayed onto the catalyst 30a from the nozzle 30b. This generates hydrogen and metaborate aqueous solution. When the first flow path L1 is closed and the second flow path L2 is open, the recovered metaborate aqueous solution is supplied to the reactor 30 as a refrigerant and sprayed onto the catalyst 30a from the nozzle 30b. This rapidly lowers the temperature of the catalyst 30a. The switching unit 50 is composed of a solenoid valve, and the switching of the switching unit 50 may be controlled by the control unit 70.

[0026] Figure 2(A) is a side view showing an example of a vehicle equipped with the power generation system 1 according to the embodiment. Figure 2(B) is a top view showing an example of a vehicle equipped with the power generation system 1 according to the embodiment. Vehicle 2 is one embodiment of a mobile body on which the power generation system 1 is mounted.

[0027] As shown in Figures 2(A) and (B), the power generation system 1 is connected to the electric motor 60 of the vehicle 2. An example of the electric motor 60 is a motor. The power from the electric motor 60 is transmitted to the wheels, which are an example of the propulsion system 80. This allows the vehicle 2 to move using the electricity supplied from the power generation system 1.

[0028] Figure 3(A) is a side view showing an example of a ship equipped with the power generation system 1 according to the embodiment. Figure 3(B) is a top view showing an example of a ship equipped with the power generation system 1 according to the embodiment. Ship 3 is one embodiment of a mobile body on which the power generation system 1 is equipped.

[0029] As shown in Figures 3(A) and 3(B), the power generation system 1 is connected to the electric motor 60 of the ship 3. An example of the electric motor 60 is a motor. The power from the electric motor 60 is transmitted to a screw, which is an example of a propulsion system 80. This allows the ship 3 to move using the electricity supplied from the power generation system 1.

[0030] Figure 4(A) is a schematic diagram showing an example of an aircraft equipped with the power generation system 1 according to the embodiment. Figure 4(B) is a plan view showing an example of an aircraft equipped with the power generation system 1 according to the embodiment. Aircraft 4 is an example of a mobile body on which the power generation system 1 is equipped.

[0031] As shown in Figures 4(A) and (B), the power generation system 1 is connected to the electric motor 60 of the aircraft 4. An example of the electric motor 60 is a motor. The power from the electric motor 60 is transmitted to a propeller, which is an example of a propulsion system 80. This allows the aircraft 4 to move using the electricity supplied from the power generation system 1.

[0032] The aircraft on which the power generation system 1 according to this embodiment is mounted is not limited to a quadcopter. The aircraft on which the power generation system 1 according to this embodiment is mounted may be an airplane, helicopter, airship, glider, or rocket, etc. The airplane may be either a jet or a propeller aircraft.

[0033] Figure 5 is a flowchart showing an example of a propulsion method according to the embodiment. The propulsion method is performed, for example, by the control unit 70 of the mobile body and power generation system 1. The propulsion method is started, for example, based on a start signal from the control unit 70. Note that some or all of the steps of the propulsion method may be performed by an operator.

[0034] First, the control unit 70 performs a preparation step (step S10) to prepare an aqueous solution containing tetrahydroborate. The control unit 70 may also operate the first supply device 10a and the second supply device 11a to prepare an aqueous solution containing tetrahydroborate at a predetermined concentration.

[0035] Next, the control unit 70 performs a hydrogen generation step (step S20) in which an aqueous solution is reacted with a catalyst to produce hydrogen and a metaborate aqueous solution. The aqueous solution is the aqueous solution prepared in the preparation step (step S10). The control unit 70 may also control the amount of aqueous solution to be reacted by operating the third supply device 20a.

[0036] Next, the control unit 70 performs a power conversion process to obtain electricity by reacting the generated hydrogen with oxygen (step S30). The hydrogen is the hydrogen produced in the hydrogen generation process (step S20). The control unit 70 may control the amount of hydrogen flowing from the buffer container 31 to the power converter 40 by controlling the gas control valve 31a.

[0037] Finally, the electric motor 60 of the mobile body drives the propulsion device 80 based on the power generated by the power converter 40, and performs the propulsion process (step S40) of movement. This concludes the flowchart shown in Figure 5.

[0038] Figure 6 is a flowchart showing an example of a cooling method. The cooling method is performed, for example, by the control unit 70 of the power generation system 1.

[0039] First, the control unit 70 performs a determination step (step S50) to determine whether or not the hydrogen generation process (step S10) has started. The control unit 70 determines that the hydrogen generation process has started if the first flow path L1 is connected to the reactor 30 and an aqueous solution containing tetrahydroborate is supplied to the reactor 30.

[0040] If it is determined that the hydrogen production process (step S10) has started (step S50: YES), the control unit 70 performs a determination step (step S52) to determine whether the catalyst temperature is above the first temperature. The first temperature is a temperature preset for determining whether cooling is necessary, and is, for example, 100 to 120°C. The control unit 70 obtains the temperature of the catalyst 30a from a temperature sensor provided in the reactor 30 and determines whether the catalyst temperature is above the first temperature.

[0041] If it is determined that the catalyst temperature is above the first temperature (step S52: YES), the control unit 70 performs a switching step (step S54) by blocking the first flow path L1 from the stock container 20 to the reactor 30.

[0042] Next, the control unit 70 performs a determination step (step S56) to determine whether the temperature of the aqueous solution in the recovery container 32 is below the third temperature. The third temperature is a predetermined temperature used to determine whether the metaborate aqueous solution generated in the reactor 30 has cooled enough to function as a refrigerant, and is typically -20 to 45°C. The control unit 70 obtains the temperature of the metaborate aqueous solution from a temperature sensor provided in the recovery container 32 and determines whether the temperature of the metaborate aqueous solution is below the third temperature.

[0043] If it is determined that the temperature of the metaborate aqueous solution is not below the third temperature (step S56: NO), the control unit 70 waits for a while and then repeats the determination process (step S56). In other words, it waits until the temperature of the metaborate aqueous solution becomes below the third temperature. The control unit 70 may set a limit on the waiting time.

[0044] If it is determined that the temperature of the metaborate aqueous solution is below the third temperature (step S56: YES), the control unit 70 opens the second flow path L2 from the recovery container 32 to the reactor 30 as a switching step (step S58). This cools the catalyst 30a.

[0045] Next, the control unit 70 performs a determination step (step S60) to determine whether the catalyst temperature is below the second temperature. The second temperature is a temperature preset for determining the end of cooling, and is, for example, 50 to 95°C. The control unit 70 obtains the temperature of the catalyst 30a from a temperature sensor provided in the reactor 30 and determines whether the catalyst temperature is below the second temperature.

[0046] If it is determined that the catalyst temperature is not below the second temperature (step S60: NO), the control unit 70 waits for a while and then repeats the determination process (step S60). In other words, it continues cooling and waits until the catalyst temperature falls below the second temperature. The control unit 70 may set a limit on the waiting time.

[0047] If it is determined that the catalyst temperature is below the second temperature (step S60: YES), the control unit 70 performs a switching step (step S62) by blocking the second flow path L2 from the recovery container 32 to the reactor 30. This completes the cooling of the catalyst 30a.

[0048] Next, the control unit 70 opens the first flow path L1 from the stock container 20 to the reactor 30 as a switching step (step S64).

[0049] The flowchart shown in Figure 6 terminates when the switching process (step S64) is completed, when it is determined that the hydrogen production process (step S10) has not started (step S50:NO), or when it is determined that the catalyst temperature is not above the first temperature (step S52:NO).

[0050] Although various exemplary embodiments have been described above, this disclosure is not limited to the embodiments described above, and various omissions, substitutions, and modifications may be made.

[0051] Hereinafter, various exemplary embodiments included in this disclosure are described in the following sections 1 to 11.

[0052] [Clause 1] A stock solution container for preparing an aqueous solution containing tetrahydroborate, A reactor having a catalyst that reacts the aqueous solution prepared in the stock solution container to produce hydrogen and a metaborate aqueous solution, A power converter that obtains electricity by reacting hydrogen and oxygen produced by the reactor, A recovery container for storing the metaborate aqueous solution produced by the reactor, A switching unit that switches between the flow path from the stock container to the reactor and the flow path from the recovery container to the reactor, A power generation system equipped with the following features. In this power generation system, a switching unit switches between the flow path from the stock solution container to the reactor and the flow path from the recovery container to the reactor. When the flow path from the stock solution container to the reactor is open, the aqueous solution prepared in the stock solution container is supplied to the reactor, generating hydrogen and metaborate aqueous solution, and the reactor temperature rises. When the flow path from the recovery container to the reactor is open, the metaborate aqueous solution stored in the recovery container is supplied to the reactor, and the reactor temperature decreases. In this way, the power generation system can control the reactor temperature simply by switching with the switching unit. Therefore, compared to a mobile unit with a heat exchanger, the power generation system can suppress the rise in reactor temperature with a simpler configuration.

[0053] [Clause 2] The power generation system according to Clause 1, wherein the reactor has a nozzle for spraying the aqueous solution prepared in the stock container or the metaborate aqueous solution stored in the recovery container onto the catalyst. In this power generation system, an aqueous solution prepared in the stock solution container is sprayed onto the catalyst by a nozzle, generating hydrogen and metaborate aqueous solution. Furthermore, when the flow path is switched, the metaborate aqueous solution is sprayed onto the catalyst by the nozzle, cooling the catalyst. In this way, hydrogen generation and catalyst cooling can be achieved using a common nozzle, thus simplifying the structure. Moreover, because the metaborate aqueous solution is sprayed directly onto the catalyst, the power generation system can lower the temperature more reliably and quickly compared to a system using a heat exchanger. As a result, the power generation system can avoid the reactor becoming too hot, which would inhibit the hydrolysis reaction, i.e., hydrogen generation, and thus achieve stable power generation. Furthermore, since the power generation system does not require a separate refrigerant, it can avoid, for example, the decrease in the concentration of the metaborate aqueous solution due to the addition of cooling water, which would increase transportation costs, or the contamination of the metaborate aqueous solution with impurities. In short, the power generation system can cool the reactor without hindering the regeneration of metaborate.

[0054] [Clause 3] The reactor is equipped with a buffer container for separating the hydrogen and metaborate aqueous solution produced by the reactor, The power generation system according to clause 1 or 2, wherein the buffer container is connected to the power converter and the recovery container. The power generation system, equipped with a buffer container, can separate hydrogen and metaborate aqueous solution, and can also store a certain amount of hydrogen. Therefore, even if the flow path from the raw material container to the reactor is blocked for cooling and hydrogen is not being generated, hydrogen can be stably supplied to the downstream power converter.

[0055] [Clause 4] A power generation system according to any one of the clauses 1 to 3, comprising a control unit that controls the switching of the switching unit based on the temperature of the catalyst. The power generation system can determine whether cooling is necessary based on the catalyst temperature and switch the flow path accordingly.

[0056] [Clause 5] The power generation system according to Clause 4, wherein the control unit controls the switching unit to open the flow path from the stock container to the reactor, and if the temperature of the catalyst rises to or above a first temperature after the stock container and the reactor are connected, the control unit controls the switching unit to block the flow path from the stock container to the reactor and open the flow path from the recovery container to the reactor. The power generation system can determine that cooling is necessary when the catalyst temperature exceeds the first temperature and switch the flow path accordingly.

[0057] [Clause 6] The power generation system according to Clause 5, wherein the control unit controls the switching unit so that, if the temperature of the catalyst falls below a second temperature after the recovery container and the reactor are connected, the flow path from the recovery container to the reactor is blocked and the flow path from the raw liquid container to the reactor is opened. The power generation system can determine that cooling is complete when the catalyst temperature falls below the second temperature, and can switch the flow path.

[0058] [Clause 7] The power generation system according to Clause 6, wherein the catalyst is made of Raney nickel, the first temperature is 100 to 120°C, the second temperature is 50 to 95°C, and the temperature of the metaborate aqueous solution stored in the recovery container is -20 to 45°C. If the temperature of the Raney nickel is too high, the water in the aqueous solution containing tetrahydroborate evaporates before the hydrolysis reaction can occur, suppressing the reaction. Lowering the temperature of the Raney nickel below 100-120°C makes the hydrolysis reaction stable and highly efficient. Conversely, if the temperature of the Raney nickel is too low, the hydrolysis reaction becomes too slow, making stable and highly efficient hydrogen generation difficult. Adjusting the temperature of the Raney nickel to 50-95°C makes the hydrolysis reaction stable and highly efficient. In addition, by setting the temperature of the metaborate aqueous solution sprayed directly onto the Raney nickel to -20-45°C, the overheated Raney nickel can be quickly cooled to the optimal temperature range.

[0059] [Clause 8] The power generation system described in any one of the clauses 1 to 7, wherein the switching unit is a three-way valve.

[0060] [Clause 9] The power generation system according to any one of the clauses 1 to 8, wherein the tetrahydroborate is a tetrahydroborate reproduced by a hydrogenation reaction using metaborate, which has been dried and extracted from the aqueous solution of the metaborate, as a raw material. Sodium borohydride, chemically produced from borax, is extremely expensive and not practical as an energy source. Tetrahydroborate, reproduced by hydrogenation using metaborate (e.g., sodium metaborate) dried and extracted from metaborate generated in the process described in Clause 1, is inexpensive and significantly reduces electricity supply costs.

[0061] [Clause 10] The power converter is at least one of a fuel cell and an internal combustion engine generator, according to any one of the power generation systems described in any one of paragraphs 1 to 9.

[0062] [Clause 11] A step of preparing an aqueous solution containing tetrahydroborate, A step of supplying the aqueous solution to a catalyst and generating hydrogen and metaborate aqueous solution by catalytic action, A step of storing the generated metaborate aqueous solution, A step of reacting the generated hydrogen with oxygen to obtain electricity, If the temperature of the catalyst reaches a first temperature or higher during the hydrogen generation process, the stored metaborate aqueous solution is sprayed onto the catalyst to cool it down. A method of generating electricity, including

[0063] The following describes an embodiment implemented by the inventors in order to explain the effects of the power generation system and mobility method according to the embodiment. In the embodiment, the control of the electric mobile body and the processing of temperature measurement signals were performed using a PLC (Programmable Logic Controller).

[0064] (Example 1) 47g of sodium borohydride stored in the raw material container 10 was dispensed by operating the screw feeder, which is the first supply device 10a, for 10 seconds. The dispensed sodium borohydride was then poured into the stock container 20 through piping.

[0065] 308 mL of water stored in the water container 11 was pumped through the piping using the pump, which is the second supply device 11a. The pumped water was then poured through the piping into the stock solution container 20. The sodium borohydride and water in the stock solution container 20 were stirred to prepare an aqueous sodium borohydride solution. Hereafter, the aqueous sodium borohydride solution may be referred to as the "stock solution".

[0066] The concentrate stored in the concentrate container 20 was pumped out by the third supply device 20a. The pumped concentrate was sprayed onto the Raney nickel inside the reactor 30 by a spray nozzle located inside the reactor 30. The reactor 30 was filled with 330 g of Raney nickel held in a retaining mesh.

[0067] The stock solution underwent hydrolysis upon contact with Raney nickel, as shown in formula (1) above, generating hydrogen and an aqueous metaborate solution. The heat of reaction from the reaction in formula (1) caused the temperature of the Raney nickel filled in the reactor 30 to rise. The aqueous sodium metaborate solution and hydrogen generated by the reaction in formula (1) passed through the Raney nickel and flowed into the buffer container 31 located below the reactor 30.

[0068] While generating hydrogen, the temperature of the Raney nickel catalyst 30a was measured using a thermocouple installed inside the Raney nickel. When the measured temperature reached a preset 120°C, the switching unit 50 stopped the supply of the stock solution, and instead, a 20°C metaborate aqueous solution (sodium metaborate aqueous solution) stored in the recovery container 32 was pumped through the second channel L2 and sprayed through the switching unit 50 to the Raney nickel filled inside the reactor 30 via the nozzle 30b. This caused the temperature of the Raney nickel filled inside the reactor 30 to decrease. Then, when the measured temperature reached a preset 70°C using a thermocouple installed inside the Raney nickel, the switching unit 50 stopped the supply of the sodium metaborate aqueous solution, and instead, the stock solution stored in the stock solution container 20 was supplied through the first channel L1 and sprayed through the switching unit 50 to the Raney nickel filled inside the reactor 30 via the nozzle 30b. In this way, hydrogen and an aqueous solution of sodium metaborate were generated while maintaining the temperature of the Raney nickel.

[0069] The sodium metaborate aqueous solution and hydrogen that flowed into the buffer container 31 were separated into gas and liquid. The sodium metaborate aqueous solution flowed into the recovery container 32. The hydrogen was depressurized by the gas control valve 31a and then supplied to the polymer electrolyte fuel cell, which is the power converter 40. Power was generated in the polymer electrolyte fuel cell. The power generated by the polymer electrolyte fuel cell was stable at 0.95 kW.

[0070] Electricity from a polymer electrolyte fuel cell was used to drive an induction motor (rated at 1 kW). The thrust generated by the induction motor propelled an electric vehicle (a four-wheeled automobile). The electric vehicle traveled at a speed of 20 km / h.

[0071] (Example 2) The following describes an example in which an electric mobile vehicle (boat) is propelled by the thrust generated by an induction motor. The process until the solid polymer fuel cell generates electricity is the same as in Example 1 described above.

[0072] Electricity from a polymer electrolyte fuel cell was used to drive an induction motor (rated at 1 kW). The thrust generated by the induction motor propelled the electric vehicle (boat). The electric vehicle traveled at a speed of 5.4 knots. (Example 3) The following describes an example in which an electric aircraft (quadcopter) is flown using thrust generated by an induction motor. The process until the solid polymer fuel cell generates electricity is the same as in Examples 1 and 2 described above.

[0073] The electricity generated from the polymer electrolyte fuel cell powered four induction motors (rated 0.25 kW). Each induction motor's corresponding propeller rotated in response to its operation. The thrust generated by the four induction motors allowed the electric vehicle to fly to an altitude of 10 meters. [Explanation of symbols]

[0074] 1...Power generation system, 20...Concentrate container, 30...Reactor, 40...Power converter, 50...Switching unit.

Claims

1. A stock solution container for preparing an aqueous solution containing tetrahydroborate, A reactor having a catalyst that reacts the aqueous solution prepared in the stock solution container to produce hydrogen and a metaborate aqueous solution, A power converter that obtains electricity by reacting hydrogen and oxygen produced by the reactor, A recovery container for storing the metaborate aqueous solution produced by the reactor, A switching unit that switches between the flow path from the stock container to the reactor and the flow path from the recovery container to the reactor, A power generation system equipped with the following features.

2. The power generation system according to claim 1, wherein the reactor has a nozzle for spraying the aqueous solution prepared in the stock container or the metaborate aqueous solution stored in the recovery container onto the catalyst.

3. The reactor is equipped with a buffer container for separating the hydrogen and metaborate aqueous solution produced by the reactor, The power generation system according to claim 1 or 2, wherein the buffer container is connected to the power converter and the recovery container.

4. The power generation system according to claim 1 or 2, further comprising a control unit that controls the switching of the switching unit based on the temperature of the catalyst.

5. The power generation system according to claim 4, wherein the control unit controls the switching unit to open the flow path from the stock container to the reactor, and when the temperature of the catalyst rises to or above a first temperature after the stock container and the reactor are connected, the control unit controls the switching unit to block the flow path from the stock container to the reactor and open the flow path from the recovery container to the reactor.

6. The power generation system according to claim 5, wherein the control unit controls the switching unit so that, if the temperature of the catalyst falls below a second temperature after the recovery container and the reactor are connected, the flow path from the recovery container to the reactor is blocked and the flow path from the raw liquid container to the reactor is opened.

7. The power generation system according to claim 6, wherein the catalyst is made of Raney nickel, the first temperature is 100 to 120°C, the second temperature is 50 to 95°C, and the temperature of the metaborate aqueous solution stored in the recovery container is -20 to 45°C.

8. The power generation system according to claim 1 or 2, wherein the switching unit is a three-way valve.

9. The power generation system according to claim 1 or 2, wherein the tetrahydroborate is a tetrahydroborate reproduced by a hydrogenation reaction using metaborate, which is dried and extracted from the aqueous solution of the metaborate, as a raw material.

10. The power generation system according to claim 1 or 2, wherein the power converter is at least one of a fuel cell and an internal combustion engine generator.

11. A step of preparing an aqueous solution containing tetrahydroborate, A step of supplying the aqueous solution to a catalyst and generating hydrogen and metaborate aqueous solution by catalytic action, A step of storing the generated metaborate aqueous solution, A step of reacting the generated hydrogen with oxygen to obtain electricity, If the temperature of the catalyst reaches a first temperature or higher during the hydrogen generation process, the stored metaborate aqueous solution is sprayed onto the catalyst to cool it down. A method of generating electricity, including

Images