Hydrogen generator and power generator

Abstract

To provide a hydrogen generator capable of surely and efficiently generating hydrogen.SOLUTION: An apparatus 1 for generating hydrogen by causing a metal material and a reaction liquid to react with each other in a reaction tank 10 includes the reaction tank 10 in which an alkaline reaction liquid is stored, a raw material supply device 20 that continuously supplies the raw material containing the metal material to the reaction tank 10, and a control device that controls an operation of the raw material supply device 20.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a hydrogen generation device and a power generation device. [Background technology]

[0002] In order to realize a hydrogen-based society, technology for generating hydrogen from waste aluminum, such as aluminum dross, which is generated in large quantities through industrial activities, has been attracting attention in recent years. As a conventional hydrogen generation device, Patent Document 1 discloses a waste aluminum treatment device that supplies waste aluminum via a conveyor to a reaction tank containing an alkaline aqueous solution, causes a reaction, and extracts the generated hydrogen from a hydrogen outlet. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-190906 Summary of the Invention [Problem to be solved by the invention]

[0004] In the conventional waste aluminum treatment device described above, the reaction between aluminum and an alkaline aqueous solution in a reaction tank does not proceed easily at around room temperature, but once the reaction starts and the temperature rises, the reaction progresses rapidly, making it difficult to control the reaction. Therefore, if a large amount of waste aluminum is added to the reaction tank while the reaction is progressing slowly, even if the supply of waste aluminum is stopped after the reaction has progressed, the reaction of the aluminum remaining in the reaction tank continues, and the reaction may become out of control.

[0005] Therefore, an object of the present invention is to provide a hydrogen generation device that can reliably and efficiently generate hydrogen, and a power generation device using the same. [Means for solving the problem]

[0006] The above-mentioned object of the present invention is achieved by a hydrogen generation apparatus comprising a reaction tank for storing an alkaline reaction liquid, a raw material supply device for continuously supplying raw materials containing a metal material to the reaction tank, and a control device for controlling the operation of the raw material supply device, which generates hydrogen by reacting the metal material with the reaction liquid in the reaction tank, and further comprising a flow rate measurement unit for measuring the flow rate of hydrogen discharged from the reaction tank, and the control device controls the supply of the raw material to the reaction tank based on the measurement by the flow rate measurement unit.

[0007] In this hydrogen generation apparatus, it is preferable that the control device calculates the amount of raw material remaining in the reaction tank based on the cumulative amount of raw material supplied to the reaction tank and the cumulative amount of hydrogen discharged from the reaction tank, and controls the supply of the raw material to the reaction tank based on the amount of raw material remaining. The control device can correct the calculated value of the amount of raw material remaining based on the instantaneous amount of hydrogen discharged from the reaction tank. Alternatively, by further including a temperature measurement unit that measures the temperature of the reaction liquid stored in the reaction tank, the control device can correct the calculated value of the amount of raw material remaining based on the measurement by the temperature measurement unit. The control device can control the calculated remaining amount of raw material so as to maintain it within a reference range by controlling the supply of the raw material. In this case, the control device may correct the reference range based on the instantaneous amount of hydrogen discharged from the reaction tank. Alternatively, if the control device further includes a temperature measurement unit that measures the temperature of the reaction liquid stored in the reaction tank, the control device may correct the reference range based on the measurement by the temperature measurement unit.

[0008] The above object of the present invention is also achieved by a power generation device comprising the above hydrogen generation device and a fuel cell that generates power using hydrogen generated by the hydrogen generation device. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a hydrogen generation device that can reliably and efficiently generate hydrogen, and a power generation device using the same. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic configuration diagram of a power generation device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram of a hydrogen generation device provided in the power generation device shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Fig. 1 is a schematic diagram of a power generation device according to one embodiment of the present invention. As shown in Fig. 1, the power generation device 100 includes a hydrogen generation device 1 that generates hydrogen from supplied raw materials, and a fuel cell 90 that generates electricity using the hydrogen generated by the hydrogen generation device 1. The fuel cell 90 may be, for example, a solid polymer type, but its configuration is not particularly limited.

[0012] The hydrogen generator 1 includes a reaction vessel 10, a raw material supply device 20, a produced gas treatment device 30, a residue transfer device 40, and a separation device 50.

[0013] The reaction tank 10 includes a sealable tank body 11. The tank body 11 includes two supply units 11a and 11b. A reaction liquid such as an aqueous sodium hydroxide solution is supplied from one supply unit 11a, and cooling water is supplied from the other supply unit 11b. The reaction liquid L1 stored in the tank body 11 may be an alkaline aqueous solution such as potassium hydroxide or the like in addition to an aqueous sodium hydroxide solution, and is preferably a strong alkaline aqueous solution. Inside the tank body 11, a horizontally arranged mesh pan 12 and a temperature measurement unit 13 including a thermocouple or the like for measuring the temperature of the stored reaction liquid L1 are provided.

[0014] The raw material supply device 20 includes a raw material storage tank 21 in which raw materials are stored, a weighing scale 22 that measures the mass of the raw material contained in the raw material storage tank 21, a feeder 23 that feeds a predetermined amount of raw material contained in the raw material storage tank 21 by vibrating a trough, a holding tank 24 that holds the raw material fed by the feeder 23, and a cylindrical feed conveyor 25 that transports the raw material in the holding tank 24 and continuously feeds it into the reaction tank 10. The feed conveyor 25 is, for example, a screw conveyor, and the feed rate of the raw material to the reaction tank 10 can be controlled by adjusting the rotation speed of the drive motor using inverter control. The holding tank 24 and the feed conveyor 25 are water-sealed with water seal water L2 to prevent hydrogen produced in the reaction tank 10 from flowing back toward the raw material supply device 20.

[0015] The raw material supplied from the raw material supply device 20 to the reaction vessel 10 may be any raw material containing a metal material that reacts with the stored reaction liquid L1 to generate hydrogen. Preferred examples of such metal materials include aluminum, zinc, and silicon. In this embodiment, a solid raw material made of waste aluminum such as residue from an aluminum melting furnace, aluminum cans, and aluminum building materials is used. The shape of the raw material is not particularly limited, but it is preferably large enough to be reliably held on the mesh pan 12 in a pre-reaction state. The hydrogen generated in the reaction vessel 10 is discharged to the outside through the gas discharge section 11c.

[0016] The produced gas treatment device 30 includes a cooler 31, a water seal tank 32, a flow rate measurement unit 33, a gas storage tank 34, and a high-pressure gas storage tank 35. The cooler 31 cools the hydrogen gas containing water vapor discharged from the gas discharge unit 11c by heat exchange with water cooled in a cooling tower 31a. The water vapor condenses and is returned to the reaction tank 10, while the hydrogen gas passes through a water seal tank 32 containing water seal water to isolate it from the outside air, where its purity is increased. The hydrogen gas then passes through a flow rate measurement unit 33, such as a mass flow meter, where its flow rate (mass flow rate) is measured, and the hydrogen gas is then stored in a gas storage tank 34, which is a water seal tank. The hydrogen gas stored in the gas storage tank 34 is pressurized by a booster pump 34a and stored in a high-pressure gas storage tank 35. The water cooled by the cooling tower 31a may be used to cool the water seal tank 32 and the water seal water in the gas storage tank 34, or to cool the tank body 11 of the reaction tank 10.

[0017] The residue conveying device 40 is composed of a water-sealed screw conveyor, and conveys and discharges to the outside the residue that remains as a solid after the reaction between the reaction liquid L1 and the raw materials in the reaction tank 10. As shown in an enlarged partial view in Figure 1, the mesh 12a of the mesh pan 12 arranged inside the tank body 11 is set to a size that prevents the raw material M from passing through but allows the residue R to pass through. The residue that has passed through the mesh pan 12 is discharged to the outside from a residue discharge section 11d formed at the bottom of the tank body 11 by operating the residue conveying device 40 as needed.

[0018] In this embodiment, only one mesh tray 12 is provided inside the tank body 11, but multiple mesh trays 12 may be arranged vertically at intervals, with the mesh size of the lower mesh trays 12 becoming smaller. The raw materials held on the mesh tray 12 gradually become smaller as the reaction proceeds and eventually pass through the mesh along with the residue. By arranging multiple mesh trays 12 as described above, the raw materials can be held in stages on each mesh tray 12 and reacted with the reaction liquid L1. In addition, a stirring mechanism such as a stirring blade may be provided inside the tank body 11, which can forcibly stir the reaction liquid L1 to suspend the raw materials in the reaction liquid L1 and promote the reaction between the raw materials and the reaction liquid L1.

[0019] The separation device 50 is equipped with a crystallization tank 51 and a centrifuge 52. When the raw material is aluminum, the crystallization tank 51 precipitates aluminum hydroxide crystals contained in the reaction liquid L1 discharged together with the residue from the reaction tank 10, and discharges the supernatant sodium hydroxide aqueous solution to the outside. The centrifuge 52 centrifuges the aluminum hydroxide crystals precipitated in the crystallization tank 51 from the sodium hydroxide aqueous solution, and discharges both to the outside.

[0020] Fig. 2 is a block diagram of the hydrogen generator 1. As shown in Fig. 2, the operations of the raw material supply device 20, the produced gas treatment device 30, the residue transfer device 40, and the separation device 50 are controlled by a control device 60. Information measured by the temperature measurement unit 13, the meter 22, and the flow rate measurement unit 33 is input to the control device 60.

[0021] Next, the operation of the hydrogen generator 1 provided in the above-described power generation device 100 will be described. A reaction liquid L1, such as an aqueous sodium hydroxide solution, supplied from a supply unit 11a is stored in the tank body 11 of the reaction tank 10. When the raw material supply unit 20 is operated in this state, raw materials are continuously supplied to the tank body 11, and aluminum contained in the raw materials reacts with the aqueous sodium hydroxide solution to generate hydrogen. The amount of raw materials supplied from the raw material supply unit 20 to the reaction tank 10 is measured by a meter 22, and the temperature of the reaction liquid L1 during the reaction is measured by a temperature measurement unit 13.

[0022] The hydrogen produced in the reaction vessel 10 is discharged from the gas discharge section 11c and supplied to the produced gas treatment device 30, where the flow rate is measured by the flow rate measuring section 33, and then the hydrogen is stored in the high-pressure gas storage tank 35 via the gas storage tank 34. The hydrogen stored in the high-pressure gas storage tank 35 can be supplied to the fuel cell 90 at an appropriate timing to generate electricity at the raw material treatment site. Meanwhile, the residue produced after the reaction in the reaction vessel 10 is discharged from the residue discharge section 11d and transported to the outside by the residue transport device 40. The reaction liquid L1 discharged from the residue discharge section 11d together with the residue is supplied to the separation device 50, where the aqueous sodium hydroxide solution and aluminum hydroxide are separated and recovered.

[0023] The reaction liquid L1 in the reaction tank 10 gradually decreases as the reaction proceeds and as the residue is discharged from the residue discharge part 11d, so that the reaction liquid L1 is replenished from the supply part 11a as needed to maintain a predetermined water level. The aqueous sodium hydroxide solution recovered in the separation device 50 can be reused for this replenishment.

[0024] In the reaction vessel 10, the reaction rate does not necessarily remain constant between the metallic material, such as aluminum, contained in the raw material and the reaction solution. For example, the reaction rate increases when the temperature of the reaction solution rises as the reaction progresses, or decreases when an oxide film forms on the surface of the metallic material as the reaction progresses. Therefore, if the amount of raw material reacting in the reaction vessel 10 remains small relative to the amount of raw material supplied from the raw material supply device 20 to the reaction vessel 10, excessive amounts of raw material may accumulate in the reaction vessel 10, making it impossible to control the reaction.

[0025] Therefore, the flow rate of hydrogen, which is correlated with the reaction amount of the raw material, is measured by the flow rate measuring unit 33, and the control device 60 controls the supply of raw material to the reaction tank 10 based on the measurement by the flow rate measuring unit 33, thereby preventing the supply amount of raw material from significantly exceeding the reaction amount in the reaction tank 10 and preventing excessive accumulation of raw material in the reaction tank 10.

[0026] More specifically, the control device 60 calculates the cumulative amount of raw material supplied to the reaction vessel 10 based on the measurement by the measuring device 22, and calculates the cumulative amount of hydrogen discharged from the reaction vessel 10 based on the measurement by the flow rate measuring unit 33, and calculates the amount of raw material remaining in the reaction vessel 10 from the cumulative amount of raw material supplied and the cumulative amount of discharged. This allows the amount of raw material remaining in the reaction vessel 10 to be estimated in real time, and for example, the control device 60 controls the supply of raw material so as to maintain this amount of raw material remaining within a reference range, thereby accurately balancing the amount of raw material supplied and the reaction rate in the reaction vessel 10 and ensuring efficient hydrogen production. Note that if the content ratio of metal materials in the raw materials can be known to some extent in advance by obtaining composition information of the raw materials or performing component analysis of the raw materials, this content ratio may be taken into account when calculating the amount of raw material remaining.

[0027] While maintaining a high temperature of the reaction liquid L1 in the reaction tank 10 can promote the reaction, if the temperature is too high, there is a risk of the reaction going out of control. Therefore, when the temperature measured by the temperature measurement unit 13 exceeds a set temperature (e.g., 90°C), the control device 60 supplies cooling water from the supply unit 11b to the tank body 11 to cool the reaction liquid L1. The temperature and temperature rise rate of the reaction liquid L1 measured by the temperature measurement unit 13 are indicators of the reaction state in the reaction tank 10. Therefore, the control device 60 can more accurately estimate the remaining amount of raw material by correcting the calculated remaining amount of raw material based on the measurement by the temperature measurement unit 13. For example, if the measured temperature rise rate exceeds a reference value, it can be determined that the calculated remaining amount of raw material is greater than the actual remaining amount of raw material. Therefore, by correcting the calculated remaining amount of raw material to reduce it, the calculated remaining amount of raw material can be made closer to the actual remaining amount of raw material.

[0028] Furthermore, since the instantaneous amount of hydrogen discharged from the reaction vessel 10 is also an indicator of the reaction state in the reaction vessel 10, the control device 60 can more accurately estimate the remaining amount of raw material by correcting the calculated remaining amount of raw material based on the instantaneous flow rate of hydrogen measured by the flow rate measurement unit 33. For example, if the measured instantaneous flow rate exceeds a reference value, it can be determined that the calculated remaining amount of raw material is greater than the actual remaining amount of raw material, and therefore the calculated remaining amount of raw material can be corrected to decrease it, thereby making it closer to the actual remaining amount of raw material.

[0029] In this embodiment, the calculated remaining raw material amount is corrected based on measurements by the temperature measurement unit 13 or the instantaneous amount of hydrogen discharged from the reaction vessel 10. However, instead of correcting the remaining raw material amount, the above-mentioned reference range, which serves as an indicator of the appropriate remaining raw material amount, may be corrected. Since the reaction efficiency of the raw material introduced into the reaction vessel 10 can change due to changes in the surface condition, etc., as the reaction progresses, the appropriate reference range for the remaining raw material amount may change in real time. Therefore, by correcting the above-mentioned reference range based on measurements by the temperature measurement unit 13 or the instantaneous amount of hydrogen discharged from the reaction vessel 10, it is possible to constantly optimize hydrogen generation in the reaction vessel 10. [Explanation of symbols]

[0030] 1. Hydrogen generator 10 Reaction vessel 13 Temperature measurement section 20 Raw material supply device 22 Measuring instrument 30 Produced gas treatment device 33 Flow measurement section 40 Residue transport device 50 Separation device 60 Control device 90 Fuel Cell 100 Power generating equipment

Claims

1. a reaction tank in which an alkaline reaction solution is stored; a raw material supply device that continuously supplies raw materials containing metal materials to the reaction vessel; a control device for controlling the operation of the raw material supply device, An apparatus for generating hydrogen by reacting the metal material with the reaction solution in the reaction tank, Further, a flow rate measuring unit is provided to measure the flow rate of hydrogen discharged from the reaction vessel, The control device controls the supply of the raw material to the reaction vessel based on the measurement by the flow rate measurement unit.

2. 2. The hydrogen generation apparatus according to claim 1, wherein the control device calculates a remaining amount of raw material in the reaction tank based on an integrated amount of raw material supplied to the reaction tank and an integrated amount of hydrogen discharged from the reaction tank, and controls the supply of the raw material to the reaction tank based on the remaining amount of raw material.

3. The hydrogen generation apparatus according to claim 2 , wherein the control device corrects the calculated value of the remaining amount of raw material based on the instantaneous amount of hydrogen discharged from the reaction tank.

4. 3. The hydrogen generation apparatus according to claim 2, wherein the control device maintains the calculated remaining amount of raw material within a reference range by controlling the supply of the raw material, and corrects the reference range based on the instantaneous amount of hydrogen discharged from the reaction tank.

5. Further provided is a temperature measurement unit for measuring the temperature of the reaction liquid stored in the reaction tank, The hydrogen generation apparatus according to claim 2 , wherein the control device corrects the calculated value of the remaining amount of raw material based on the measurement by the temperature measurement unit.

6. Further provided is a temperature measurement unit for measuring the temperature of the reaction liquid stored in the reaction tank, 3. The hydrogen generation apparatus according to claim 2, wherein the control device maintains the calculated remaining amount of raw material within a reference range by controlling the supply of the raw material, and corrects the reference range based on the measurement by the temperature measurement unit.

7. The hydrogen generator according to claim 1; a fuel cell that generates electricity using the hydrogen generated by the hydrogen generator.

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