Hydrogen production equipment

Abstract

A hydrogen production device capable of producing hydrogen without using an insulating diaphragm is provided. [Solution] The system comprises a reaction vessel 2 for containing raw material containing water, an electrode 20 provided within the reaction vessel 2, a heating device 40 that generates a mixed gas containing hydrogen by heating the reaction vessel 2 so that the raw material is in a subcritical or supercritical state when a predetermined voltage is applied to the electrode 20, a gas passage 60 through which the mixed gas generated within the reaction vessel 2 passes, and a hydrogen separator 160 provided in the gas passage 60 for recovering hydrogen contained in the mixed gas.

Description

[Technical Field]

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

[0002] Patent Document 1 discloses a technique for obtaining hydrogen gas by electrolyzing water. Specifically, Patent Document 1 discloses a technique for electrolyzing water by bringing water in an anode chamber and a cathode chamber, which are separated by an insulating diaphragm that is permeable to hydrogen ions and hydroxide ions but poorly breathable, to a subcritical or supercritical state. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-279782 Summary of the Invention [Problem to be solved by the invention]

[0004] As in Patent Document 1, when electrolyzing water by bringing the water to a subcritical or supercritical state, an insulating diaphragm is required. However, since the temperature of water in a subcritical or supercritical state is high, the durability of the insulating diaphragm may become an issue. Therefore, there is a demand for an apparatus that can generate hydrogen without using an insulating diaphragm. [Means for solving the problem]

[0005] A hydrogen production apparatus for solving the above problems includes a reaction vessel for containing a raw material containing water, electrodes provided in the reaction vessel, a heating device for heating the reaction vessel so that the raw material is brought into a subcritical or supercritical state while a predetermined voltage is applied to the electrodes, thereby generating a mixed gas containing hydrogen, a gas passage through which the mixed gas generated in the reaction vessel passes, and a hydrogen separator provided in the gas passage for recovering hydrogen contained in the mixed gas. , does not have an insulating diaphragm .

[0006] According to the above configuration, the hydrogen production device recovers hydrogen by passing a mixed gas generated by applying a voltage to a source material in a subcritical or supercritical state through a hydrogen separator. Therefore, the hydrogen production device can generate hydrogen without using an insulating diaphragm.

[0007] The hydrogen production device may further include a pressure regulating valve that regulates the pressure inside the reaction vessel, and the pressure regulating valve may be located in the gas passage upstream of the hydrogen separator in the flow of the mixed gas.

[0008] The hydrogen production device may further include a first heat exchanger that cools the mixed gas in the gas passage, and the first heat exchanger may be located in the gas passage upstream of the pressure regulating valve in the flow of the mixed gas.

[0009] The hydrogen production device may further include an air supply device that supplies air to the gas passage upstream of the hydrogen separator in the flow of the mixed gas and downstream of the first heat exchanger in the flow of the mixed gas.

[0010] The hydrogen production device may further include a second heat exchanger that heats the mixed gas in the gas passage, the second heat exchanger being located in the gas passage upstream of the hydrogen separator in the flow of the mixed gas and downstream of the first heat exchanger and the air supply device in the flow of the mixed gas. The predetermined voltage may be 1.23 V or more.

[0011] The electrode may have a plurality of split electrodes arranged in parallel, a spacer located between each of the plurality of split electrodes, and a conductive connecting member supporting the plurality of split electrodes, wherein the plurality of split electrodes include a first split electrode and a second split electrode adjacent to the first split electrode, and the connecting member may include a first connecting member that contacts the first split electrode but does not contact the second split electrode, and a second connecting member that contacts the second split electrode but does not contact the first split electrode.

[0012] The hydrogen production device may further include a control device that controls the heating device, and the control device may control the heating device so that the temperature inside the reaction vessel is 120°C or higher and 374°C or lower. [Effects of the Invention]

[0013] According to the above technical concept, hydrogen can be produced by the hydrogen production device without using an insulating diaphragm. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a configuration diagram of a hydrogen production device according to an embodiment. [Figure 2] FIG. 2 is a schematic diagram of the electrodes of the hydrogen production device of FIG. [Figure 3] FIG. 3 is a schematic diagram of one of the hollow fiber filters of the hydrogen separator of the hydrogen production apparatus of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0015] (Embodiment) Hereinafter, one embodiment of the hydrogen production device 1 will be described with reference to the drawings. Hereinafter, the upstream side of the flow of gas or liquid in hydrogen production will be referred to as "upstream." The downstream side of the flow of gas or liquid in hydrogen production will be referred to as "downstream."

[0016] <Reaction vessel> As shown in FIG. 1, the hydrogen production device 1 includes a reaction vessel 2. The reaction vessel 2 is a container for containing a raw material containing water. The raw material is a material that serves as a raw material for producing hydrogen. In this embodiment, the raw material is water. The reaction vessel 2 is, for example, an electrolytic cell.

[0017] The reaction vessel 2 has a supply port 2A. The supply port 2A is a portion of the reaction vessel 2 to which raw materials are supplied from a tank 12 of a supply device 10. The supply port 2A is connected to a supply passage 11 of the supply device 10.

[0018] The reaction vessel 2 has an outlet 2B. A mixed gas containing hydrogen generated in the reaction vessel 2 is discharged from the outlet 2B. The mixed gas contains, for example, hydrogen, oxygen, and water vapor. After being discharged from the outlet 2B, the mixed gas generated in the reaction vessel 2 passes through a gas passage 60, which will be described later.

[0019] Although not shown, a thermometer and a pressure gauge are attached inside the reaction vessel 2. The thermometer measures the temperature inside the reaction vessel 2 and outputs the result to the control device 50, which will be described later. The pressure gauge measures the pressure inside the reaction vessel 2 and outputs the result to the control device 50, which will be described later.

[0020] <Feeding device> The hydrogen production apparatus 1 includes a supply device 10. The supply device 10 is a device for supplying raw materials to the reaction vessel 2. The supply device 10 includes a supply passage 11, a tank 12, a pump 13, and a first check valve 14. The supply passage 11 connects the reaction vessel 2 and the tank 12.

[0021] Tank 12 stores raw material. Tank 12 is located in supply passage 11 at the most upstream side in the flow of raw material. Pump 13 supplies raw material stored in tank 12 into reaction vessel 2. Pump 13 is located in supply passage 11 downstream of tank 12 in the flow of raw material. First check valve 14 is located downstream of pump 13 in the flow of raw material supplied. First check valve 14 allows raw material to flow from tank 12 to reaction vessel 2. On the other hand, first check valve 14 prevents raw material from flowing back from reaction vessel 2 to tank 12.

[0022] <Electrode> As shown in FIG. 1, the hydrogen production device 1 includes an electrode 20. The electrode 20 is provided in a reaction vessel 2. At least a portion of the electrode 20 may be exposed from the reaction vessel 2. The electrode 20 transfers electrons to and from a source material in a subcritical or supercritical state. Note that FIG. 1 conceptually illustrates the electrode 20.

[0023] As shown in Fig. 2, the electrode 20 includes a plurality of split electrodes 21, a spacer 22, and a connecting member 23. Each split electrode 21 is generally disk-shaped. The split electrodes 21 are arranged in parallel such that their main surfaces are parallel to one another. Note that Fig. 2 shows only three split electrodes 21.

[0024] As shown in FIG. 2, each split electrode 21 has a first through hole 21A and a second through hole 21B. The first through holes 21A and the second through holes 21B are arranged alternately and at equal intervals along the circumference of the split electrode 21. The split electrode 21 has, for example, two first through holes 21A. The two first through holes 21A are arranged in positions that are point-symmetric with respect to the center of the split electrode 21. The split electrode 21 has, for example, two second through holes 21B. The two second through holes 21B are arranged in positions that are point-symmetric with respect to the center of the split electrode 21. The second through holes 21B include a plurality of protrusions 21C. The protrusions 21C protrude toward the centers of the second through holes 21B.

[0025] The multiple split electrodes 21 include a first split electrode 24 and a second split electrode 25. The first split electrodes 24 and the second split electrodes 25 are alternately arranged with a gap between them. Therefore, the second split electrode 25 is adjacent to the first split electrode 24. In the direction in which the split electrodes 21 are arranged, the position of the first through hole 21A of the second split electrode 25 overlaps the position of the second through hole 21B of the first split electrode 24. In addition, in the direction in which the split electrodes 21 are arranged, the position of the second through hole 21B of the second split electrode 25 overlaps the position of the first through hole 21A of the first split electrode 24.

[0026] The electrode 20 has a spacer 22. The spacer 22 is located between adjacent divided electrodes 21. In other words, the spacer 22 is sandwiched between adjacent divided electrodes 21. The spacer 22 is an insulator. The material of the spacer 22 is, for example, ceramic, glass, plastic, or the like. The spacer 22 may be a plurality of washers or a mesh sheet. When the spacer 22 is a mesh sheet, the sheet has holes located at approximately the same positions as the first through holes 21A or the second through holes 21B. In the following, the spacer 22 will be described as a plurality of ceramic washers 22A.

[0027] Each washer 22A is arranged to surround the first through-hole 21A or the second through-hole 21B. In Fig. 2, for the sake of ease of understanding the structure of the electrode 20, the spacing between the divided electrodes 21 is depicted as being larger than the thickness of the spacer 22.

[0028] The electrode 20 has a connecting member 23. The connecting member 23 supports each of the divided electrodes 21. The connecting member 23 passes through the first through-hole 21A and the second through-hole 21B. The connecting member 23 is a conductor. That is, the connecting member 23 is conductive. The connecting member 23 is, for example, a metal rod.

[0029] The connecting member 23 includes a first connecting member 23A and a second connecting member 23B. The first connecting member 23A is inserted into the second through hole 21B of the first split electrode 24 and the first through hole 21A of the second split electrode 25. Therefore, the first connecting member 23A also penetrates the washer 22A. The outer peripheral surface of the first connecting member 23A contacts the protrusion 21C of the second through hole 21B of the first split electrode 24. On the other hand, the outer peripheral surface of the first connecting member 23A does not contact the inner peripheral surface of the first through hole 21A of the second split electrode 25. In other words, the first connecting member 23A contacts the first split electrode 24 but does not contact the second split electrode 25.

[0030] The second connecting member 23B is inserted into the first through hole 21A of the first split electrode 24 and the second through hole 21B of the second split electrode 25. Therefore, the second connecting member 23B also penetrates the washer 22A. The outer peripheral surface of the second connecting member 23B contacts the protrusion 21C of the second through hole 21B of the second split electrode 25. On the other hand, the outer peripheral surface of the second connecting member 23B does not contact the inner peripheral surface of the second through hole 21B of the first split electrode 24. In other words, the second connecting member 23B contacts the second split electrode 25 but does not contact the first split electrode 24.

[0031] <Power supply> As shown in FIG. 1 , the hydrogen production device 1 further includes a power supply 30. The power supply 30 is a DC power supply. The power supply 30 is connected to the electrodes 20. Specifically, the positive electrode 31 of the power supply 30 is connected to the first connecting member 23A. The negative electrode 32 of the power supply 30 is connected to the second connecting member 23B. The power supply 30 applies a predetermined voltage between the positive electrode 31 and the negative electrode 32. The predetermined voltage is set depending on the raw material. The predetermined voltage is, for example, 1.23 V or higher. Although not shown, the power supply 30 has a current detector that detects the current flowing between the positive electrode 31 and the negative electrode 32.

[0032] <Heating device> The hydrogen production device 1 includes a heating device 40. The heating device 40 is disposed around the reaction vessel 2. The heating device 40 includes, for example, a heater that heats the reaction vessel 2 by electricity or gas.

[0033] The heating device 40 heats the reaction vessel 2 so that the source material in the reaction vessel 2 is in a subcritical or supercritical state. The pressure inside the reaction vessel 2 increases as the reaction vessel 2 is heated by the heating device 40. With a predetermined voltage applied to the electrode 20, the heating device 40 heats the reaction vessel 2 so that the source material is in a subcritical or supercritical state, thereby generating a mixed gas containing hydrogen.

[0034] The raw material in the reaction vessel 2 heated by the heating device 40 described above is brought to a subcritical or supercritical state. When the water is brought to a subcritical or supercritical state, the ionic product of the water increases significantly, thereby increasing the electrical conductivity of the water. This makes it easier for current to flow through the electrode 20.

[0035] The supercritical state is the state of a raw material when its temperature and pressure exceed its critical point. In the supercritical state, the raw material becomes a supercritical fluid, where the distinction between gas and liquid disappears. The temperature at the critical point of a raw material is called the critical temperature. When the raw material is water, the critical temperature is 374°C. The pressure at the critical point of a raw material is called the critical pressure. When the raw material is water, the critical pressure is 22.1 MPa.

[0036] The subcritical state is a state in which the temperature is lower than the critical temperature and the pressure is higher than atmospheric pressure. In the subcritical state, the source material coexists as a gas and a liquid, but exhibits properties different from normal evaporation and condensation. The temperature of the source material in the subcritical state is called the subcritical temperature. The subcritical temperature is higher than the boiling point of the source material at atmospheric pressure. When the source material is water, the subcritical temperature is 120°C or higher and lower than 374°C. The subcritical temperature is preferably 200°C or higher and lower than 374°C.

[0037] The pressure of the source material in the subcritical state is called subcritical pressure. Subcritical pressure is higher than atmospheric pressure. The subcritical pressure is, for example, 0.5 MPa or higher. Preferably, the subcritical pressure is 2.5 MPa or higher. When the subcritical pressure is higher than the critical pressure, the subcritical temperature is lower than the critical temperature.

[0038] <Control device> The hydrogen production device 1 further includes a control device 50. The control device 50 controls the heating device 40. The control device 50 also controls the application of voltage from the power source 30 to the electrode 20 and the operation of the pump 13. The control device 50 includes a processing unit that executes a predetermined control program. The processing unit includes, for example, a CPU (Central Processing Unit) or an MPU (Micro Processing Unit).

[0039] The control device 50 includes a storage medium. The storage medium includes a nonvolatile memory and a volatile memory. The nonvolatile memory includes, for example, at least one of a read-only memory (ROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), and a flash memory. The volatile memory includes, for example, a random access memory (RAM).

[0040] The control device 50 acquires temperature information inside the reaction vessel 2 from a thermometer provided in the reaction vessel 2. The control device 50 also acquires pressure information inside the reaction vessel 2 from a pressure gauge provided in the reaction vessel 2. The control device 50 controls the heating device 40 based on at least one selected from the temperature information and the pressure information. The control device 50 controls the output amount of the heating device 40 based on, for example, a table showing the relationship between the output amount of the heating device 40 and at least one of the temperature and pressure inside the reaction vessel 2. The table showing the relationship between the output amount of the heating device 40 and at least one of the temperature and pressure inside the reaction vessel 2 is stored in advance in, for example, a storage medium of the control device 50.

[0041] The control device 50 controls the heating device 40 to heat the reaction vessel 2 so that the source material is in a subcritical or supercritical state. The control device 50 controls the heating device 40, for example, so that the temperature inside the reaction vessel 2 is 374°C or higher. The control device 50 controls the heating device 40, for example, so that the temperature inside the reaction vessel 2 is 120°C or higher and lower than 374°C.

[0042] The control device 50 transmits an operation signal or a stop signal to the pump 13 based on the current detected by a current detector provided in the power supply 30. The operation signal is a signal for operating the pump 13. The stop signal is a signal for stopping the operation of the pump 13. When a water level sensor is provided in the reaction vessel 2, the control device 50 may transmit an operation signal or a stop signal to the pump 13 based on the output of the water level sensor.

[0043] The control device 50 sends an operation signal to the pump 13 when the current flowing through the electrode 20 falls below a predetermined current value. The power supply 30 sends a stop signal when the current flowing through the electrode 20 exceeds a predetermined current value. In this way, the pump 13 repeatedly starts and stops supplying water to the reaction vessel 2 based on the signal from the control device 50. This control makes it possible to maintain the amount of liquid water in the reaction vessel 2.

[0044] <Gas passage> The hydrogen production device 1 includes a gas passage 60. The gas passage 60 is a passage through which a mixed gas containing hydrogen generated in the reaction vessel 2 passes. The gas passage 60 connects the outlet 2B of the reaction vessel 2 and the hydrogen tank 70.

[0045] From the outlet 2B of the reaction vessel 2, water in a subcritical or supercritical state may be discharged into the gas passage 60 together with the mixed gas. The water in a subcritical or supercritical state returns to gaseous or liquid water when at least one of the temperature and pressure is reduced. Therefore, even if a raw material in a subcritical or supercritical state is present in the gas passage 60, it will be recovered or discharged as a liquid or gas.

[0046] <1st heat exchanger> The hydrogen production device 1 includes a first heat exchanger 100. The first heat exchanger 100 is located in the gas passage 60, upstream of a pressure regulating valve 122, which will be described later. That is, the reaction vessel 2 is connected to the first heat exchanger 100 via the gas passage 60. The first heat exchanger 100 is located on the anti-gravity side of the reaction vessel 2.

[0047] The first heat exchanger 100 cools the mixed gas in the gas passage 60. The first heat exchanger 100 converts part of the water vapor in the mixed gas back into water by cooling the mixed gas discharged from the reaction vessel 2. The water converted from gas to liquid by the first heat exchanger 100 returns into the reaction vessel 2 by gravity or the like.

[0048] Some of the devices arranged in the gas passage 60 have heat-sensitive components such as rubber packing. For example, various valves such as the pressure adjustment valve 122 include rubber packing. As described above, the high-temperature mixed gas is cooled by the first heat exchanger 100. Therefore, devices located downstream of the first heat exchanger 100 in the gas passage 60 are less likely to deteriorate.

[0049] <Air supply device> The hydrogen production device 1 includes an air supply device 110. The air supply device 110 includes a compressor or a fan. The air supply device 110 supplies air at a first pressure or higher to the gas passage 60. The first pressure is, for example, approximately equal to the pressure of the mixed gas. The air supplied by the air supply device 110 increases the flow rate of the mixed gas in the gas passage 60.

[0050] The air supply device 110 supplies air to the gas passage 60 upstream of a hydrogen separator 160 (described later) and downstream of the first heat exchanger 100. More specifically, the air supply device 110 supplies air to the gas passage 60 upstream of a pressure regulating valve 122 (described later) and downstream of the first heat exchanger 100.

[0051] <Pressure Regulating Device> The hydrogen production device 1 includes a pressure regulating device 120. The pressure regulating device 120 includes a pressure regulating passage 121, a pressure regulating valve 122, and a first flashback arrestor 123.

[0052] The pressure adjustment passage 121 branches off from the gas passage 60 downstream of the first heat exchanger 100 and the air supply device 110. The pressure adjustment valve 122 and the first flashback arrestor 123 are disposed in the pressure adjustment passage 121. The pressure adjustment valve 122 adjusts the pressure inside the reaction vessel 2. The pressure adjustment valve 122 is located in the pressure adjustment passage 121 upstream of the first flashback arrestor 123.

[0053] In this embodiment, the pressure regulating valve 122 is a relief valve for protecting the system from excessive pressure. The pressure regulating valve 122 opens when the pressure in the reaction vessel 2 or the gas passage 60 exceeds the upper limit pressure. The upper limit pressure is set, for example, so that the reaction vessel 2 and the gas passage 60 do not exceed the pressure that they can withstand.

[0054] The pressure regulating valve 122 closes when the pressure in the reaction vessel 2 or the gas passage 60 falls below a predetermined pressure. The predetermined pressure is lower than the upper limit pressure. The predetermined pressure is equal to or higher than the critical pressure. When the raw material is water, the predetermined pressure is equal to or higher than 22.1 MPa. Because the predetermined pressure is equal to or higher than the critical pressure, the raw material in the reaction vessel 2 does not boil when the pressure regulating valve 122 closes. The pressure at which the pressure regulating valve 122 opens and closes can be adjusted, for example, by adjusting the elastic force of the spring that biases the valve element of the pressure regulating valve 122.

[0055] The first flashback arrestor 123 prevents a flame from flowing back when the flammable gas discharged from the pressure regulating valve 122 ignites. The first flashback arrestor 123 is located downstream of the pressure regulating valve 122 in the pressure regulating passage 121. The gas discharged from the pressure regulating valve 122 passes through the first flashback arrestor 123 and is released into the atmosphere. The gas discharged from the pressure regulating valve 122 contains hydrogen and oxygen and is therefore flammable. The first flashback arrestor 123 can prevent flashback in the gas passage 60 and the reaction vessel 2.

[0056] The pressure regulator 120 may include a valve for reducing the pressure of the mixed gas. For example, this valve is located downstream of the pressure regulator valve 122. The valve is always active to control the downstream pressure. The valve enables the pressure regulator 120 to release the mixed gas to the atmosphere at a stable pressure even when the upstream pressure fluctuates significantly.

[0057] <Moisture removal device> The hydrogen production device 1 includes a moisture removal device 130. The moisture removal device 130 includes a drain passage 131, a steam-water separator 132, a first valve 133, and a return pipe 134. The drain passage 131 branches off from the gas passage 60. Specifically, the drain passage 131 is connected to the gas passage 60 downstream of the branch point of the pressure adjustment passage 121. The drain passage 131 connects the steam-water separator 132 and the return pipe 134. The first valve 133 is a float valve. The first valve 133 is arranged in the drain passage 131.

[0058] The water-steam separator 132 is a device for removing moisture remaining in the gas passage 60. The water-steam separator 132 is located at the connection point between the gas passage 60 and the water drain passage 131. Therefore, the water-steam separator 132 is located in the gas passage 60 upstream of the hydrogen separator 160, which will be described later, and downstream of the pressure regulating valve 122. Hereinafter, the water drain passage 131 downstream of the water-steam separator 132 and upstream of the first valve 133 will be referred to as the first water drain passage 131A. The water drain passage 131 downstream of the first valve 133 and connected to the return pipe 134 will be referred to as the second water drain passage 131B.

[0059] The first valve 133, which is a float valve, is located closer to the gravity direction than the water-steam separator 132. The water separated from the gas mixture by the water-steam separator 132 accumulates in the first drain passage 131A. The first valve 133 moves up and down in accordance with fluctuations in the water level. The position of the water level fluctuates depending on the amount of water accumulated in the first drain passage 131A. The first valve 133 opens when the water level reaches a predetermined position or higher. The first valve 133 closes when the water level falls below the predetermined position. Although not shown in FIG. 1 , the return pipe 134 is connected to the tank 12. The water separated by the water-steam separator 132 is supplied to the tank 12 through the return pipe 134.

[0060] <Second heat exchanger> The hydrogen production device 1 includes a second heat exchanger 140. The second heat exchanger 140 heats the mixed gas in the gas passage 60. The second heat exchanger 140 reduces the humidity of the mixed gas by heating the mixed gas. The second heat exchanger 140 is provided in the gas passage 60.

[0061] The second heat exchanger 140 is located in the gas passage 60 upstream of the hydrogen separator 160, which will be described later, and downstream of the first heat exchanger 100 and the air supply device 110. More specifically, the second heat exchanger 140 is located in the gas passage 60 upstream of the hydrogen separator 160 and downstream of the moisture removal device 130.

[0062] The second heat exchanger 140 reduces the humidity of the mixed gas by heating the mixed gas, but as long as the humidity of the mixed gas can be reduced, the hydrogen production device 1 may be provided with another device instead of or in addition to the second heat exchanger 140. The hydrogen production device 1 may be provided with an adsorption-type drying device such as silica gel, zeolite, and activated alumina instead of or in addition to the second heat exchanger 140.

[0063] <Hydrogen separator> The hydrogen production device 1 includes a hydrogen separator 160. The hydrogen separator 160 includes a filter for recovering hydrogen contained in the mixed gas. The hydrogen separator 160 is located midway through the gas passage 60. Specifically, the hydrogen separator 160 is located in the gas passage 60 downstream of the second heat exchanger 140 and upstream of the hydrogen discharge device 180, which will be described later.

[0064] The pressure in the gas passage 60 upstream of the hydrogen separator 160 is higher than that in the gas passage 60 downstream of the hydrogen separator 160 due to the pressure generated in the reaction vessel 2. The hydrogen separator 160 filters the mixed gas due to the pressure difference between the gas passage 60 upstream of the hydrogen separator 160 and the gas passage 60 downstream of the hydrogen separator 160. Furthermore, the flow rate of the mixed gas in the gas passage 60 increases due to the air supplied by the air supply device 110. Therefore, the hydrogen separator 160 can efficiently filter the mixed gas.

[0065] As shown in FIGS. 1 and 3, the hydrogen separator 160 includes a plurality of hollow fiber filters 161. The hollow fiber filters 161 are tubular. The hollow fiber filters 161 include through-holes 162 and a polymer membrane 163. The polymer membrane 163 is a membrane that allows hydrogen to pass easily but does not allow other atoms to pass easily. Hydrogen that has adhered to the polymer membrane 163 moves toward the through-holes 162. The through-holes 162 are connected to the gas passage 60 downstream of the hydrogen separator 160.

[0066] After adhering to the polymer membrane 163 and moving to the through-holes 162, hydrogen may again adhere to the polymer membrane 163 and pass through in the opposite direction from the through-holes 162. Hydrogen may also not adhere to the polymer membrane 163 and pass through the hollow fiber filter 161. The polymer membrane 163 of the hollow fiber filter 161 has the property of making it difficult for atoms other than hydrogen to pass through, but this does not mean that it does not pass through all atoms other than hydrogen. Therefore, some of the oxygen and water vapor contained in the mixed gas may pass through the hollow fiber filter 161.

[0067] Therefore, by providing hollow fiber filters 161 at multiple locations in the gas passage 60, the hydrogen recovery rate can be improved. In other words, by providing hollow fiber filters 161 in a multi-stage configuration along the gas flow direction, the hydrogen recovery rate can be improved. For example, the number of stages of hollow fiber filters 161 required to achieve a hydrogen recovery rate of 99% or more is set to a predetermined number. In this case, the number of stages of hollow fiber filters 161 included in one hydrogen separator 160 may be set to a predetermined number, or hydrogen separators 160 each including a number of hollow fiber filters 161 obtained by equally dividing the predetermined number may be arranged in parallel.

[0068] <Gas exhaust device> As shown in FIG. 1 , the hydrogen production apparatus 1 includes a gas discharge device 170. The gas discharge device 170 includes a discharge passage 171, a second valve 172, and a second flashback arrestor 173. The discharge passage 171 branches off from the gas passage 60 at a location where the hydrogen separator 160 is provided. The mixed gas from which hydrogen has been recovered by the hydrogen separator 160 is called a dehydrogenated mixed gas. Main components contained in the dehydrogenated mixed gas are, for example, oxygen, water vapor, and air. The dehydrogenated mixed gas may contain a portion of hydrogen depending on the performance of the hydrogen separator 160. The dehydrogenated mixed gas passes through the discharge passage 171.

[0069] The second valve 172 is disposed in the discharge passage 171. The second valve 172 is a relief valve. The second valve 172 adjusts the pressure in the discharge passage 171. The second valve 172 is located in the discharge passage 171 upstream of the second flashback arrestor 173 in the gas flow direction. The second valve 172 opens when the pressure in the discharge passage 171 from the hydrogen separator 160 to the second valve 172 becomes greater than a second pressure. The second valve 172 closes when the pressure in the discharge passage 171 from the hydrogen separator 160 to the second valve 172 becomes equal to or less than the second pressure.

[0070] The second flashback arrestor 173 is disposed in the discharge passage 171. The second flashback arrestor 173 prevents a flame from flowing back when the flammable gas is ignited. The dehydrogenated gas mixture passes through the second flashback arrestor 173 and is released into the atmosphere. The dehydrogenated gas mixture contains oxygen and is therefore highly flammable. The second flashback arrestor 173 can prevent flashback into the gas passage 60 and the reaction vessel 2.

[0071] <Hydrogen exhaust device> The hydrogen production device 1 includes a hydrogen discharge device 180. The hydrogen discharge device 180 is a device for adjusting the pressure of the hydrogen recovered by the hydrogen recovery device to a pressure required by the user and discharging it. The hydrogen discharge device 180 is disposed downstream of the hydrogen separator 160 in the gas passage 60. Therefore, the hydrogen-rich gas separated by the hydrogen separator 160 is supplied to the hydrogen discharge device 180.

[0072] The hydrogen discharge device 180 includes a second check valve 181. The second check valve 181 is provided to prevent hydrogen from flowing back into the hydrogen separator 160. The second check valve 181 is disposed in the gas passage 60, downstream of the hydrogen separator 160.

[0073] The hydrogen discharge device 180 includes an accumulator 182. The accumulator 182 is disposed in the gas passage 60 downstream of the second check valve 181. The accumulator 182 temporarily stores hydrogen in a high-pressure state.

[0074] The hydrogen discharge device 180 includes a hydrogen pump 183. The hydrogen pump 183 is disposed in the gas passage 60 downstream of the accumulator 182. The hydrogen pump 183 compresses the hydrogen temporarily stored in the accumulator 182 and then discharges it.

[0075] The hydrogen pump 183 has a pressure gauge for measuring the pressure of the hydrogen pump 183. The pressure gauge for measuring the pressure of the hydrogen pump 183 is not shown in the drawing. The hydrogen pump 183 has a capacity meter for measuring the volume of hydrogen temporarily stored in the accumulator 182. The capacity meter is not shown in the figure. The capacity meter estimates the volume of hydrogen in the accumulator 182, for example, by measuring the pressure inside the accumulator 182.

[0076] The hydrogen pump 183 operates when the pressure of the hydrogen pump 183 is equal to or lower than the third pressure and when a predetermined volume or more of hydrogen is stored in the accumulator 182. The hydrogen pump 183 does not operate when the pressure detected by the pressure gauge is higher than the third pressure. The hydrogen pump 183 does not operate when the hydrogen in the accumulator 182 is lower than the predetermined volume. The third pressure is higher than the pressure when the hydrogen pump 183 operates normally.

[0077] If damage or corrosion occurs to the components that make up the hydrogen pump 183, the pressure of the hydrogen pump 183 may become higher than the pressure when the hydrogen pump 183 is operating normally. The hydrogen pump 183 does not operate when the pressure detected by the pressure gauge becomes higher than the third pressure. The hydrogen pump 183 does not operate when the amount of hydrogen in the accumulator 182 is less than a predetermined volume.

[0078] The hydrogen discharge device 180 includes a pressure reducing valve 184. The pressure reducing valve 184 is arranged in the gas passage 60 downstream of the hydrogen pump 183. The pressure reducing valve 184 reduces the pressure of the hydrogen compressed by the hydrogen pump 183. A hydrogen user can use the pressure reducing valve 184 to reduce the pressure of the hydrogen to the required level.

[0079] The hydrogen discharge device 180 includes an on-off valve 185. The on-off valve 185 is disposed in the gas passage 60 downstream of the pressure reducing valve 184. The on-off valve 185 switches between opening and closing the gas passage 60 leading to the hydrogen tank 70.

[0080] The hydrogen production device 1 includes a hydrogen tank 70. The hydrogen tank 70 is a tank 12 for storing hydrogen separated from a gas mixture. The hydrogen tank 70 is disposed in the gas passage 60 downstream of the open / close valve 185. The hydrogen tank 70 is replaceable. When replacing the hydrogen tank 70, the open / close valve 185 is used to close the gas passage 60 leading to the hydrogen tank 70, thereby preventing hydrogen from leaking.

[0081] <Hydrogen production flow> An example of the flow of hydrogen production in this embodiment will be described with reference to Fig. 1. The raw material supplied from tank 12 to reaction vessel 2 by pump 13 is heated by heating device 40. When the temperature inside reaction vessel 2 increases, the raw material inside reaction vessel 2 becomes gaseous. When the raw material becomes gaseous, the pressure inside reaction vessel 2 increases.

[0082] As a result of the above, when the temperature inside the reaction vessel 2 is equal to or higher than the supercritical temperature and the pressure inside the reaction vessel 2 is equal to or higher than the supercritical pressure, the raw material enters a supercritical state. When the temperature inside the reaction vessel 2 is equal to or higher than the subcritical temperature and the pressure inside the reaction vessel 2 is lower than the supercritical pressure, the raw material enters a subcritical state. When the temperature inside the reaction vessel 2 is lower than the supercritical temperature and the pressure inside the reaction vessel 2 is equal to or higher than the subcritical pressure, the raw material enters a subcritical state. When the temperature inside the reaction vessel 2 is equal to or higher than the subcritical temperature and the pressure inside the reaction vessel 2 is equal to or higher than the subcritical pressure, the raw material enters a subcritical state.

[0083] The raw material in a subcritical or supercritical state is more reactive than normal gas or liquid. In this state, electrons are transferred by the electrode 20, generating a mixed gas containing hydrogen. The mixed gas passes through the first heat exchanger 100, the moisture removal device 130, the steam separator 132, the hydrogen separator 160, and the hydrogen discharge device 180, thereby producing highly pure hydrogen.

[0084] <Actions and Effects of the Embodiment> The operation and effects of the embodiment will be described. (1) A hydrogen production device 1 for solving the above problems includes a reaction vessel 2, an electrode 20, a heating device 40, a gas passage 60, and a hydrogen separator 160. The heating device 40 generates a mixed gas containing hydrogen by heating the reaction vessel 2 so that the raw materials are in a subcritical or supercritical state while a predetermined voltage is applied to the electrode 20. The hydrogen contained in the mixed gas generated in the reaction vessel 2 is recovered by the hydrogen separator 160 in the gas passage 60. With this configuration, the hydrogen production device 1 can generate hydrogen without using an insulating diaphragm.

[0085] (2) The hydrogen production device 1 includes a pressure regulating valve 122 located in the gas passage 60 upstream of the hydrogen separator 160 in the flow of the mixed gas. With this configuration, the pressure regulating valve 122 can regulate the pressure inside the reaction vessel 2 so that the pressure of the mixed gas does not exceed the pressure that the gas passage 60 and the reaction vessel 2 can withstand.

[0086] (3) The hydrogen production device 1 cools the mixed gas in the gas passage 60 by the first heat exchanger 100, which is located in the gas passage 60 on the upstream side of the flow of the mixed gas relative to the pressure regulating valve 122. According to this configuration, the first heat exchanger 100 reduces the temperature of the mixed gas downstream of the first heat exchanger 100. This makes it possible to suppress deterioration of the pressure regulating valve 122, which is located downstream of the first heat exchanger 100.

[0087] (4) In the hydrogen production device 1, the air supply device 110 supplies air to the gas passage 60 upstream of the hydrogen separator 160 in the flow of the mixed gas and downstream of the first heat exchanger 100 in the flow of the mixed gas. This configuration can suppress deterioration of the performance of the hydrogen separator 160 over time.

[0088] (5) The hydrogen production device 1 heats the mixed gas in the gas passage 60 using the second heat exchanger 140, which is located in the gas passage 60 upstream of the hydrogen separator 160 in the flow of the mixed gas and downstream of the first heat exchanger 100 and the air supply device 110 in the flow of the mixed gas. With this configuration, the second heat exchanger 140 can reduce the humidity of the mixed gas entering the hydrogen separator 160. This can prevent clogging of the hydrogen separator 160 due to water vapor.

[0089] (6) The predetermined voltage is 1.23 V or more. According to this configuration, a predetermined voltage equal to or higher than the voltage at which water is electrolyzed is applied to the electrode 20. Therefore, hydrogen and oxygen are likely to be generated in the reaction vessel 2.

[0090] (7) Electrode 20 includes a plurality of split electrodes 21 arranged in parallel, spacers 22 positioned between each of the split electrodes 21, and conductive connecting members 23 supporting the plurality of split electrodes 21. The plurality of split electrodes 21 includes a first split electrode 24 and a second split electrode 25 adjacent to first split electrode 24. Connecting members 23 include a first connecting member 23A that contacts first split electrode 24 but does not contact second split electrode 25, and a second connecting member 23B that contacts second split electrode 25 but does not contact first split electrode 24. With this configuration, electrode 20 is divided, which increases the area of ​​electrode 20 that comes into contact with the source material.

[0091] (8) The hydrogen production apparatus 1 further includes a control device 50 that controls the heating device 40. The control device 50 controls the heating device 40 so that the temperature inside the reaction vessel 2 is 120°C or higher and lower than 374°C. With this configuration, the control device 50 can control the heating device 40 so that the temperature inside the reaction vessel 2 is at a temperature at which the raw materials are easily reactive.

[0092] <Example of change> The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined with each other within the scope of technical compatibility.

[0093] The raw material may contain water as a solvent and a solute that dissolves in water. The solute may include, for example, carbon dioxide. In this modified example, the hydrogen production device 1 may include a gas collection device for collecting gases other than hydrogen contained in the mixed gas.

[0094] The order of heating the reaction vessel 2 by the heating device 40 and applying the predetermined voltage by the electrode 20 is not particularly limited. The electrode 20 may apply the predetermined voltage after the reaction vessel 2 is heated by the heating device 40 so that the source material is in a subcritical or supercritical state.

[0095] The hollow fiber filter 161 of the embodiment is an example of a hydrogen separator 160 that recovers hydrogen by membrane separation. Any device that can separate hydrogen from a mixed gas can be used as the hydrogen separator 160. The hydrogen separator 160 may be, for example, a device that separates hydrogen by known pressure swing adsorption and a palladium alloy membrane.

[0096] At least one of the pressure regulating valve 122, the first heat exchanger 100, the air supply device 110, the moisture removal device 130, and the second heat exchanger 140 may be omitted. For example, the second heat exchanger 140 and the moisture removal device 130 may be omitted by constantly keeping the mixed gas at a temperature equal to or lower than the ambient temperature in the first heat exchanger 100 so that the mixed gas is at room temperature in the gas passage 60. In this modified example, the hydrogen production device 1 can also generate hydrogen by applying a predetermined voltage to the raw material in a subcritical or supercritical state and separating the hydrogen in the hydrogen separator 160.

[0097] The air supply device 110 may supply air to the gas passage 60 upstream of the second heat exchanger 140 and downstream of the moisture removal device 130. The air supply device 110 may supply air to the gas passage 60 upstream of the hydrogen separator 160 and downstream of the second heat exchanger 140. In this modified example, the air supply device 110 preferably supplies dry air to the gas passage 60.

[0098] The pressure regulating valve 122 may be an electromagnetic valve. The electromagnetic valve is, for example, a solenoid valve that opens and closes using a solenoid. When the pressure regulating valve 122 is an electromagnetic valve, a pressure gauge is provided in the reaction vessel 2 or the gas passage 60. A thermometer is provided in the reaction vessel 2. The electromagnetic valve is controlled by the control device 50. The control device 50 controls the electromagnetic valve based on the detection results of the thermometer and the pressure gauge. The control device 50 controls the electromagnetic valve to open when the pressure in the reaction vessel 2 or the gas passage 60 exceeds the upper limit pressure. The control device 50 controls the electromagnetic valve to close when the pressure in the reaction vessel 2 or the gas passage 60 falls below the pressure at which the raw material in the reaction vessel 2 boils at the current temperature of the reaction vessel 2. This modification prevents the raw material from boiling. This prevents air bubbles from adhering to the surface of the electrode 20, thereby preventing a decrease in the contact area between the raw material and the electrode 20.

[0099] The predetermined voltage may be less than 1.23 V. The predetermined voltage can be determined appropriately taking into consideration the voltage at which the raw material is electrolyzed, the size of the electrode 20, the contact area between the electrode 20 and the raw material, and the like.

[0100] The electrode 20 is not limited to a configuration having segmented electrodes 21 as in the embodiment. The structure of the electrode 20 can be modified as appropriate as long as a voltage can be applied to the source material in a subcritical or supercritical state. The electrode 20 may be a general electrode for electrolysis.

[0101] The control device 50 may control the heating device 40 so that the temperature of the reaction vessel 2 becomes lower than 120°C. When the control device 50 controls the heating device 40 so that the temperature of the reaction vessel 2 becomes lower than 120°C, the hydrogen production device 1 further includes a pressure applying device for applying a pressure to the raw material so that the raw material becomes subcritical or supercritical.

[0102] A plurality of reaction vessels 2 may be connected together. In this case, a heating device 40 may be provided for each reaction vessel 2, or the plurality of reaction vessels 2 may be heated by a number of heating devices 40 less than the number of the reaction vessels 2.

[0103] The return pipe 134 does not have to be connected to the tank 12 as in the above embodiment. The return pipe 134 may be directly connected to the supply port 2A of the reaction vessel 2. A pressure reducing valve may be provided instead of the second flashback arrestor 173. In this modification, an oxygen tank for storing the dehydrogenated gas mixture containing oxygen may be provided downstream of the pressure reducing valve.

[0104] In the above embodiments, if an object is made up of multiple objects, the multiple objects may be integrated, and conversely, if an object is made up of a single object, it may be divided into multiple objects. Regardless of whether the objects are integrated or not, it is sufficient that the object of the invention can be achieved.

[0105] The predetermined pressure is not particularly limited to the numerical values ​​in the embodiment, and can be changed appropriately depending on the type of source material, as long as it is lower than the upper limit pressure. In the above embodiments, where multiple functions are provided in a distributed manner, some or all of the multiple functions may be provided in a consolidated manner, and conversely, where multiple functions are provided in a consolidated manner, some or all of the multiple functions may be provided in a distributed manner. Regardless of whether the functions are distributed or consolidated, it is sufficient as long as the configuration is such that the object of the invention can be achieved. [Explanation of symbols]

[0106] 1...hydrogen production device, 2...reaction vessel, 20...electrode, 21...segmented electrode, 22...spacer, 23...connecting member, 23A...first connecting member, 23B...second connecting member, 24...first segmented electrode, 25...second segmented electrode, 40...heating device, 50...control device, 60...gas passage, 100...first heat exchanger, 110...air supply device, 122...pressure regulating valve, 140...second heat exchanger, 160...hydrogen separator.

Claims

1. a reaction vessel containing raw materials including water; an electrode provided in the reaction vessel; a heating device that generates a mixed gas containing hydrogen by heating the reaction vessel so that the source material is in a subcritical or supercritical state while a predetermined voltage is applied to the electrodes; a gas passage through which the mixed gas generated in the reaction vessel passes; a hydrogen separator provided in the gas passage for recovering hydrogen contained in the mixed gas; Does not have an insulating diaphragm, Hydrogen production equipment.

2. a pressure regulating valve for regulating the pressure inside the reaction vessel; the pressure regulating valve is located in the gas passage upstream of the hydrogen separator in the flow of the mixed gas. The hydrogen production device according to claim 1 .

3. a first heat exchanger for cooling the mixed gas in the gas passage; the first heat exchanger is located in the gas passage upstream of the pressure regulating valve in the flow of the mixed gas; The hydrogen production device according to claim 2 .

4. an air supply device that supplies air to a portion of the gas passage upstream of the hydrogen separator in the flow of the mixed gas and downstream of the first heat exchanger in the flow of the mixed gas, The hydrogen production device according to claim 3 .

5. a second heat exchanger configured to heat the mixed gas in the gas passage; the second heat exchanger is located in the gas passage upstream of the hydrogen separator in the flow of the mixed gas, and downstream of the first heat exchanger and the air supply device in the flow of the mixed gas. The hydrogen production device according to claim 4.

6. The predetermined voltage is 1.23 V or more. The hydrogen production device according to claim 1 .

7. The electrode is A plurality of segmented electrodes arranged in parallel; a spacer positioned between each of the plurality of segmented electrodes; a conductive connecting member that supports the plurality of segmented electrodes, the plurality of divided electrodes include a first divided electrode and a second divided electrode adjacent to the first divided electrode, The connecting members include a first connecting member that contacts the first divided electrode but does not contact the second divided electrode, and a second connecting member that contacts the second divided electrode but does not contact the first divided electrode. The hydrogen production device according to claim 1 .

8. Further, a control device for controlling the heating device is provided. the control device controls the heating device so that the temperature inside the reaction vessel is 120°C or higher and lower than 374°C. The hydrogen production device according to claim 1 .

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