Hydrogen production device and hydrogen production method

Abstract

To provide a hydrogen manufacturing apparatus capable of manufacturing a lot of hydrogen without hindrance.SOLUTION: A hydrogen manufacturing apparatus 1 capable of manufacturing hydrogen by mechanochemically reacting a product processed with water and an inorganic matter includes: a crusher 2 including a processed product supply port 22, a processed product exhaust port 23 and a cylindrical crushing container 21; a holding tank 3 for holding the processed product processed by the crusher; and a circulation line 40 for circulating the processed product and the water between the crusher and the holding tank. The holding tank includes an addition opening 32 for adding an alkali component or an acid component and an exhaust port 33 for exhausting hydrogen gas.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a hydrogen production device and a hydrogen production method for producing hydrogen by causing a mechanochemical reaction between water and an inorganic substance to be treated. [Background technology]

[0002] There are various methods for producing hydrogen, but water electrolysis is seen as a promising method for producing hydrogen from renewable energy.

[0003] On the other hand, as disclosed in Patent Documents 1 and 2, it is known that hydrogen can be generated by a mechanochemical reaction simply by placing water and an iron-based grinding medium in the container of a planetary ball mill and stirring them.

[0004] When considering mass production of hydrogen through a mechanochemical reaction, it is difficult to scale up the process using a planetary ball mill, and production efficiency is also low. Furthermore, Patent Document 1 also describes that hydrogen can be generated by adding silicon and sodium hydroxide to water and grinding the mixture in a planetary ball mill. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-47789 [Patent Document 2] Japanese Patent Application Laid-Open No. 2017-141157 Summary of the Invention [Problem to be solved by the invention]

[0006] However, when adding sodium hydroxide to the silicon water slurry during grinding, it is necessary to add sodium hydroxide at an optimal concentration that matches the particle size (specific surface area) of the silicon at the time of addition. For example, if the sodium hydroxide concentration is lower than the optimal concentration, the amount of hydrogen gas generated will decrease.

[0007] On the other hand, if sodium hydroxide is added at a concentration higher than the optimum concentration, not only will a rapid reaction occur, but a large amount of hydrogen-containing gas will be generated in a short period of time, causing the slurry to swell like caramelized sugar.

[0008] This can cause slurry and solids to leak out of the processing tank (holding tank), and the solids can then stick to the inside of the tank or the grinder, causing problems with operation.

[0009] Therefore, an object of the present invention is to provide a hydrogen production device and a hydrogen production method that are capable of producing a large amount of hydrogen without any problems. [Means for solving the problem]

[0010] In order to achieve the above-mentioned object, the hydrogen production apparatus of the present invention is a hydrogen production apparatus that produces hydrogen by causing a mechanochemical reaction between water and a treated material that is an inorganic substance, and is characterized in that it comprises a media-agitation type wet pulverizer in which an agitation rotor is disposed inside a cylindrical pulverization vessel having an inlet and an outlet for the treated material, a holding tank for the treated material to be processed by the media-agitation type wet pulverizer, and a circulation line for circulating the treated material and water between the media-agitation type wet pulverizer and the holding tank, and the holding tank has an inlet for adding an alkaline component or an acid component and an outlet for hydrogen gas.

[0011] Here, the material to be treated contains at least one element selected from the group consisting of aluminum, iron, germanium, tin, titanium, calcium, zinc, chromium, manganese, zirconium, strontium, silver, phosphorus, magnesium, vanadium, nickel, molybdenum, copper, tungsten, cobalt, lithium, barium, sodium, potassium, and rubidium.

[0012] Also, there is provided a hydrogen production device that produces hydrogen by a mechanochemical reaction between water and a treatment material that is an inorganic substance, and that includes a media-agitation type wet pulverizer in which an agitation rotor is disposed inside a cylindrical pulverization vessel having an inlet and an outlet for the treatment material, a holding tank for the treatment material to be treated by the media-agitation type wet pulverizer, a circulation line for circulating the treatment material and water between the media-agitation type wet pulverizer and the holding tank, a reaction tank having an addition port for an alkaline component or an acid component, and a liquid delivery line connected to the circulation line for delivering the treatment material to the reaction tank, wherein the treatment material is the inorganic substance described above.

[0013] The stirring rotor can also be configured to include a disk-shaped holding plate portion fixed to the rotating shaft and having multiple openings, a cylindrical stirring portion provided on the periphery of the holding plate portion and having multiple through holes, and a protrusion portion provided on the outer peripheral surface of the stirring portion.

[0014] Furthermore, the media-agitation wet pulverizer may be configured such that two of the agitation rotors are arranged at an interval on the rotary shaft.

[0015] The treated material preferably contains at least one element selected from the group consisting of iron, titanium, and manganese.

[0016] The invention also relates to a hydrogen production method for producing hydrogen by a mechanochemical reaction between water and a treated inorganic substance, the method comprising the steps of: circulating the treated material and water between a media-agitation wet grinding mill having a cylindrical grinding vessel and a holding tank to perform a grinding process; and, after stopping the circulation of the treated material and water, adding an alkaline component or an acid component to the holding tank to generate hydrogen gas, wherein the treated material is the inorganic substance described above. [Effects of the Invention]

[0017] The hydrogen production device of the present invention configured in this manner circulates the treated material and water between a media-agitation wet grinder that agitates and grinds the inorganic substance (treated material) that is to undergo a mechanochemical reaction with water, and a holding tank.

[0018] By using a media agitation type wet grinder having such a configuration, it becomes possible to produce a large amount of hydrogen without any problems.

[0019] On the other hand, by providing a reaction tank for adding an alkaline component or an acid component in addition to the holding tank used to cause a mechanochemical reaction between water and the inorganic substance being treated, it becomes possible to continuously produce hydrogen safely and efficiently.

[0020] The invention of the hydrogen production method separates the process into a process of circulating inorganic material and water between a media-agitation wet grinder and a holding tank to perform the grinding process, and a process of generating hydrogen gas by adding an alkaline component or an acid component to the ground inorganic material.

[0021] Therefore, for example, when an alkaline component having a higher concentration than the optimum concentration is added, it is possible to prevent the swelling slurry from adhering to the inside of the crusher, which would cause problems in the subsequent operation. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is an explanatory diagram showing an overview of a hydrogen production device according to an embodiment of the present invention; [Figure 2] FIG. 2 is an explanatory diagram showing the configuration of the periphery of a crushing container of the crushing processor. [Figure 3] FIG. 2 is an explanatory diagram showing the configuration of an agitator rotor disposed in a grinding chamber of a grinding container. [Figure 4] 1 is a graph showing the results of an experiment comparing the amount of hydrogen generated, which varies depending on the type of media-agitation wet pulverizer and pulverization conditions. [Figure 5]1 is a graph showing the results of an experiment comparing the amount of electricity that changes depending on the type of media-agitation wet mill and the milling conditions. [Figure 6] FIG. 2 is an explanatory view showing the configuration of the periphery of the crushing container of the crushing processor of the first embodiment. [Figure 7] FIG. 2 is a plan view illustrating the configuration of an agitator rotor disposed in a grinding chamber of the grinding container. [Figure 8] 8 is a side view seen in the direction of the arrow AA in FIG. 7. [Figure 9] 1A and 1B are diagrams illustrating the configuration of the hydrogen production device of Example 2, where FIG. 1A is an explanatory diagram of the hydrogen production device of Example 2, and FIG. 1B is an explanatory diagram of the configuration in which a small-capacity tank is arranged for comparison. [Figure 10] FIG. 10 is an explanatory diagram showing an outline of a hydrogen production device according to a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is an explanatory diagram showing an overview of a hydrogen production device 1 according to the present embodiment. The hydrogen production device 1 according to the present embodiment is a device that produces hydrogen by causing a mechanochemical reaction between water and an inorganic substance to be treated.

[0024] The hydrogen production device 1 of this embodiment includes a pulverizer 2 which is a media-agitation type wet pulverizer, a holding tank 3 for the material to be treated which is an inorganic substance, and a circulation line 40. First, the media-agitation type wet pulverizer will be described.

[0025] The process of finely pulverizing solid particles contained in a slurry to produce a dispersion of finer particles is called wet pulverization. A pulverizer that agitates the slurry-like processing liquid with media (pulverization media or stirring media) in a container and pulverizes the particles by the shear force or impact force of the media is called a media-agitation wet pulverizer.

[0026] The crushing machine 2 of this embodiment is equipped with a cylindrical crushing container 21, a supply port 22 for supplying solid particles of inorganic material and water into the interior of the crushing container 21, and a discharge port 23 for discharging a mixture of the inorganic material (processed material) crushed in the crushing container 21 and water (processed material slurry).

[0027] When the pulverizer 2 is used as a device for producing hydrogen by a mechanochemical reaction between water and an inorganic substance, solid particles of an inorganic substance containing at least one element selected from the group consisting of silicon, aluminum, iron, germanium, tin, titanium, calcium, zinc, chromium, manganese, zirconium, strontium, silver, phosphorus, magnesium, vanadium, nickel, molybdenum, copper, tungsten, cobalt, lithium, barium, sodium, potassium, and rubidium are introduced through the supply port 22.

[0028] 2, the crushing processor 2 includes a cylindrical crushing vessel 21, a rotating shaft 24 that is rotatably installed by inserting it through one side of the crushing vessel 21, and an agitating rotor 25 that is fixed to and rotates on the rotating shaft 24. That is, solid particles of an inorganic substance that are introduced together with water from the supply port 22 are agitated together with media in the crushing chamber 26a of the crushing vessel 21 by the rotation of the agitating rotor 25.

[0029] Here, the grinding media (stirring media) can be beads made of materials such as tungsten carbide, zirconia, stainless steel, alumina, silicon nitride, etc. Furthermore, the smaller the particle size of the media, the larger the specific surface area, and therefore the higher the grinding ability.

[0030] For example, a media agitation wet mill called an "SC Mill" can use beads (media) with a particle size of 0.2 to 0.8 mm to grind materials to a particle size of 0.01 to 0.1 μm. Furthermore, a media agitation wet mill called an "MSC Mill" can use microbeads (media) with a particle size of 0.03 to 0.2 mm to grind materials to a particle size of 0.001 to 0.1 μm.

[0031] The grinding chamber 26a of the grinding container 21 contains the above-mentioned media selected according to the material to be processed. The interior of the grinding container 21 is divided into a central grinding chamber 26a and a peripheral outer chamber 26b by a cylindrical separator 26. The separator 26 may be, for example, a screen type with many slits 261.

[0032] The installation of separator 26 prevents media from leaking from grinding chamber 26a to outside chamber 26b. Separator 26 allows a mixture (slurry of treated material) of water and inorganic material pulverized to a particle size of less than a predetermined size to pass through, and the slurry (treated liquid) that flows out to outside chamber 26b is discharged to the outside from outlet 23 provided in grinding vessel 21.

[0033] Here, the ratio (L / D) of the axial length (L) to the diameter (D) of the grinding chamber 26a formed in the grinding container 21 is preferably 1 or less. In Fig. 2, the ratio (L / D) of the axial length (L) to the diameter (D) of the grinding chamber 26a is 1 / 3, which is a more preferable ratio. The model named "SC Mill" mentioned above has this ratio.

[0034] These dimensional relationships (L / D) allow the agitator rotor 25 to apply maximum kinetic energy to the material and media within a limited space. By reducing the ratio (L / D) to 1 / 3 or less, the dispersion force increases, preventing media bias and allowing for a larger flow rate.

[0035] Furthermore, in the case of a pulverizer 2 such as the model "SC Mill," the agitator rotor 25 functions like a centrifugal pump, so that the pulverizer 2 itself can function as a pump and circulate the material and water in the circulation line 40 without the need to install a pump in the circulation line 40. However, this does not mean that a pump is unnecessary in all cases, and when using a large media-agitation type wet pulverizer or depending on the type of material to be processed, such as a highly viscous fluid, a circulation pump 4 is placed in the circulation line 40 to ensure stable operation.

[0036] 3 is an explanatory diagram showing the configuration of the agitator rotor 25 arranged in the grinding chamber 26a of the grinding container 21. The agitator rotor 25 includes a disk-shaped holding plate portion 251 fixed to the rotary shaft 24, a cylindrical agitator portion 252 provided on the periphery of the holding plate portion 251, and a plurality of protrusions 253 provided on the outer circumferential surface of the agitator portion 252.

[0037] Furthermore, the disk-shaped holding plate portion 251 is perforated with a plurality of openings 251a, allowing the material to be treated and the media to flow axially inside and outside the agitator rotor 25. Furthermore, a plurality of through holes 252a are perforated between the protrusions 253 of the agitator 252, and when the agitator rotor 25 rotates, the material to be treated and the media are subjected to a rotational force by the front surfaces of the protrusions 253, and are also subjected to a strong centrifugal force in the vicinity of the through holes 252a. In other words, the centrifugal force causes the material to be treated and the media to flow from the inside to the outside of the agitator rotor 25 through each of the through holes 252a, thereby generating a circulating flow at each of the through holes 252a.

[0038] That is, a strong circulating flow as shown by the arrows is generated in the grinding chamber 26a of the grinding vessel 21. This is because the material to be processed and the media are subjected to a desirable force by the rotation of the stirring rotor 25. The material to be processed and the media are vigorously stirred throughout the entire grinding chamber 26a, thereby enabling stable and highly efficient grinding processing.

[0039] A holding tank 3 is connected to the crushing processor 2 configured as above, as shown in Fig. 1. The holding tank 3 is a feed tank into which a slurry of the treated material (treatment liquid) containing solid particles of an inorganic substance (the treated material) and water is charged, and also a treatment tank into which the slurry of the treated material crushed by the crushing processor 2 flows.

[0040] In the circulation system, the holding tank 3 and the crusher 2 are connected by a circulation line 40. A circulation pump 4 is provided in the circulation line 40 as needed. The treated material slurry introduced into the holding tank 3 from an inlet 31 is stirred by an agitator 34 to maintain a uniform concentration.

[0041] The treated slurry is then extracted from the bottom of the holding tank 3 and sent to the crushing machine 2 via the circulation line 40, where it is stirred and crushed before being returned to the holding tank 3 via the circulation line 40 through the inlet 31.

[0042] In this way, the material to be treated is circulated and the pulverization process is carried out for a predetermined time. By performing the circulation operation at least seven to eight times, the material to be treated (inorganic material) in the holding tank 3 can be uniformly pulverized.

[0043] Here, if the circulation flow rate is small, there is a high probability that particles that have never passed through the crushing processor 2 will exist in the holding tank 3, but by increasing the flow rate, uniformity can be improved. This type of circulation type crushing process is excellent in terms of dispersibility, operability, maintainability, and cleanability, and is also suitable for automation.

[0044] In the hydrogen production device 1, for example, solid particles of silicon, an inorganic substance, are subjected to a mechanochemical reaction with water during the pulverization process. Then, the inorganic substance (processed material) that has been pulverized to the extent that a mechanochemical reaction occurs is reacted with an alkaline component (alkaline solution) such as sodium hydroxide that is added through the addition port 32 of the holding tank 3 to generate hydrogen gas. In addition to sodium hydroxide, sodium chloride, potassium hydroxide, sodium carbonate, an aqueous ammonia solution, etc. can be used as the alkaline component to be added.

[0045] The hydrogen gas generated in holding tank 3 is taken out from outlet 33. That is, holding tank 3 in this embodiment not only stores the inorganic substance (processed material) to be pulverized in a circulatory system, but also serves as a tank for reaction with the alkaline component.

[0046] When adding sodium hydroxide to a water slurry (processed material slurry) of pulverized silicon (processed material), it is necessary to add sodium hydroxide at an appropriate concentration that matches the particle size (specific surface area) of the silicon at the time of addition. For example, if the concentration is lower than the optimal concentration, the amount of hydrogen gas generated will be small, and if sodium hydroxide is added at a higher concentration than the optimal concentration, a rapid reaction will occur, causing a temperature rise, generating a large amount of hydrogen-containing gas in a short period of time, and causing the slurry to swell like caramelized bread.

[0047] Next, the operation of the hydrogen production device 1 and the hydrogen production method of this embodiment will be described. The hydrogen production device 1 of this embodiment configured as described above circulates the inorganic substance (processing material) to be subjected to a mechanochemical reaction with water between a crusher 2 that agitates and crushes the inorganic substance, and a holding tank 3. The ratio (L / D) of the axial length (L) to the diameter (D) of the crushing chamber 26a formed in the crushing vessel 21 of the crusher 2 is set to 1 or less.

[0048] Figure 4 is a graph showing the results of an experiment comparing the amount of hydrogen generated (mL / g) depending on the type of media-agitation wet mill and milling conditions. As media-agitation wet mills, we compared the aforementioned bead mill (model name "SC Mill") and ball mill (model name "Attritor").

[0049] The media agitation wet mill, model number "Attritor," uses balls (media) with particle diameters of 3mm to 10mm to grind the material to a particle size of 1μm or less. The amount of hydrogen generated was measured as the amount generated per 1g of silicon, the material being processed.

[0050] As for the grinding conditions, for the "SC Mill" model, beads (media) with a particle diameter φ of 0.8 mm were used, and the rotation speed of the stirring rotor 25 was changed to 7 m / s, 10 m / s, 13 m / s, and 16 m / s. On the other hand, for the "Attritor" model, balls (media) with particle diameters φ of 3 mm and 5 mm were used, and the rotation speed was changed to 200 rpm and 300 rpm.

[0051] It was found that for both models, sufficient hydrogen production could be achieved by extending the milling time. In particular, the "SC Mill" model, with a rotation speed of 10 m / s or more, was able to produce a large amount of hydrogen in a short milling time.

[0052] Meanwhile, Figure 5 is a graph showing the results of an experiment comparing the amount of electricity (kWh) that changes depending on the type of media-agitation wet mill and the milling conditions. As with the experiment in Figure 4, the media-agitation wet mill used was an "SC Mill" with the model name "Attritor," and the milling conditions were also the same as in the experiment in Figure 4. For reference, the amount of electricity required to produce 1 Nm3 of hydrogen using alkaline water electrolysis is also shown.

[0053] As can be seen from these experimental results, the use of a media-agitation wet mill makes it possible to produce large amounts of hydrogen with low power consumption. Furthermore, when using the "SC Mill" model with beads having a particle diameter of 0.8 mm and a rotation speed of 10 m / s, the amount of electricity can be reduced to approximately 1 / 2.5 compared to the "Attritor" model with balls having a particle diameter of 3 mm and a rotation speed of 200 rpm. Furthermore, compared to the reference values ​​for alkaline water electrolysis, the aforementioned "SC Mill" (particle diameter 0.8 mm, rotation speed 10 m / s) can reduce the amount of electricity to approximately 1 / 4.

[0054] In this way, by using the model "SC Mill," it becomes possible to produce large amounts of hydrogen with a low rated power (for example, 3.7 kW), allowing for effective use of renewable energy such as solar power and wind power. In particular, if the circulation pump 4 is not installed in the circulation line 40, hydrogen can be produced with even less power.

[0055] Furthermore, if the ratio (L / D) of the axial length (L) to the diameter (D) of the grinding chamber 26a is 1 / 3, as in the model "SC Mill," pressure loss is reduced, allowing the slurry containing the material to be treated to flow at a large flow rate. When the L / D is small, the flow of the slurry coincides with the direction of centrifugal force in a structure similar to that of a centrifugal pump, and the entire peripheral portion is made up of the separator 26, resulting in a very large opening area, making it possible to discharge a large flow rate of slurry and produce large amounts of hydrogen. It also becomes possible to form a pumpless circulation line 40.

[0056] In the hydrogen production method of the present embodiment, a first step is a grinding process in which an inorganic substance (processing material) such as silicon is circulated between the grinding processor 2 and the holding tank 3 until it reaches a predetermined particle size. Whether the inorganic substance (processing material) reaches the predetermined particle size can be determined by conducting a preliminary test or the like to understand the relationship between the grinding time, the number of circulations, and the particle size.

[0057] In the second step, hydrogen gas is generated by adding an alkaline component such as sodium hydroxide to the pulverized inorganic substance (processed material) stored in the holding tank 3. By stopping the circulation pump 4 during this alkaline component addition step, even if an alkaline component with a higher concentration than the optimum is added, it is possible to prevent the swelling slurry from adhering to the inside of the pulverizer 2 and interfering with subsequent operation.

[0058] Furthermore, when using a power source such as solar power generation, the operating hours of the crushing processor 2 may be limited by factors such as the length of sunlight. In such cases, a holding tank 3 with a capacity that can be processed within the operating hours can be installed, and in the first step, the inorganic substance is crushed during the daytime while the mechanochemical reaction proceeds, and in the second step, an alkaline component is added at night to generate hydrogen gas. [Example]

[0059] Hereinafter, a media-agitation type wet pulverizer having a different configuration from the pulverizer 2 described in the hydrogen production apparatus 1 of the above embodiment will be described with reference to Figures 6 to 8. Note that the same or equivalent parts as those described in the above embodiment will be described using the same terms or symbols.

[0060] The media-agitation wet grinder described in this Example 1 is a grinding processor 5 equipped with two agitation rotors 55. That is, in the grinding chamber 56a of the grinding processor 5, two agitation rotors 55, 55 attached to the rotary shaft 54 ​​are arranged with a gap between them in the axial direction.

[0061] The crushing processor 5 comprises a cylindrical crushing vessel 51, a rotating shaft 54 ​​that is rotatably installed by inserting through one side of the crushing vessel 51, and two stirring rotors 55 that are fixed to the rotating shaft 54 ​​and rotate. That is, solid particles of an inorganic substance (processing material) that are fed together with water from a supply port 52 are stirred together with media in a crushing chamber 56a of the crushing vessel 51 by the rotation of the two stirring rotors 55, and the crushed inorganic substance (processing material) and water (processing material slurry) are discharged from a discharge port 53.

[0062] The interior of the grinding container 51 is divided into a central grinding chamber 56a and a peripheral outer chamber 56b by a cylindrical separator 56. The separator 56 may be, for example, a screen type having many slits 561 formed therein.

[0063] The stirring rotor 55 includes a disk-shaped holding plate portion 551 fixed to the rotating shaft 54, a cylindrical stirring portion 552 provided on the periphery of the holding plate portion 551, and a plurality of protrusions 553 provided on the outer peripheral surface of the stirring portion 552.

[0064] Fig. 7 is a plan view illustrating the configuration of the agitator rotor 55, and Fig. 8 is a side view taken along the line AA in Fig. 7. A plurality of openings 551a are formed in the disk-shaped holding plate 551, allowing the material to be processed and media to flow axially inside and outside the agitator rotor 55. The size (inner diameter) of these openings 551a is larger than the openings 251a of the agitator rotor 25 of the crusher 2 described above, enhancing fluidity. Furthermore, a plurality of through-holes 552a are formed between the protrusions 553 of the agitator 552.

[0065] Protrusions 553 include two types of protrusions 553A and 553B that are inclined in opposite directions on the outer peripheral surface of agitator 552. When agitator rotor 55 rotates in the direction of the arrow, the front surfaces of protrusions 553A and 553B become the acting surfaces and apply a stirring force to the material to be processed and the media.

[0066] 8, the protrusions 553A are provided obliquely with respect to the axial direction so as to apply a force to the material to be processed and the media toward one end of the grinding container 51. In contrast, the protrusions 553B are provided obliquely on the opposite side to the protrusions 553A so as to apply a force to the other end of the grinding container 51. The protrusions 553A and the protrusions 553B are alternately arranged on the circumference of the stirring rotor 55.

[0067] The crushing processor 5 of Example 1 configured in this manner is characterized in that the protrusion 553A applies a force to the material to be processed and the media toward one end of the crushing container 51, and the protrusion 553B applies a force to the material to be processed and the media toward the other end of the crushing container 51.

[0068] In other words, in a conventional media-agitation type wet grinder, only a force toward the other end of the grinding container is applied, but in the grinding processor 5 of Example 1, a force toward both ends is applied. As a result, the flow toward one end and the flow toward the other end become equally strong, and the flow in the through hole 552a becomes strong, making it possible to generate a strong circulating flow throughout the entire grinding chamber 56a as shown in FIG.

[0069] In the pulverizer 5 of the hydrogen production device 1 of Example 1 configured as described above, the ratio (L / D) of the axial length (L) to the diameter (D) of the pulverization chamber 56a formed in the pulverization container 51 is set to be less than 1 and greater than 1 / 3.

[0070] Even if the ratio (L / D) of the axial length (L) to the diameter (D) of the grinding chamber 56a becomes larger than 1 / 3, by attaching two stirring rotors 55 to the rotating shaft 54 ​​of the grinding chamber 56a and optimizing the shape of the protrusions 553A, 553B of the stirring rotors 55, it becomes possible to operate the grinding chamber 56a with less power than when the ratio (L / D) is 1 / 3.

[0071] The other configurations and effects are substantially the same as those of the above-described embodiment or other examples, and therefore description thereof will be omitted. [Example]

[0072] A hydrogen production device 1A according to Example 2, which is different from the hydrogen production device 1 according to the embodiment described above, will be described below with reference to Fig. 9. Note that the same terms or the same reference numerals will be used to describe the same or equivalent parts as those described in the embodiment or Example 1.

[0073] In the hydrogen production device 1 of the above embodiment, there is no particular limitation on the capacity of the holding tank 3. In the hydrogen production device 1A described in this second embodiment, a large-capacity tank is used as the holding tank 3A.

[0074] 9(a) is a diagram illustrating the configuration of the hydrogen production device 1A of this Example 2, and FIG. 9(b) is a diagram illustrating the configuration in which a small-capacity tank a3 is provided for comparison. If the circulation flow rate is increased to produce a large amount of hydrogen, the commonly used small-capacity tank a3 may not be able to cope. Here, the small-capacity tank a3 has a volume about 10 times the volume of the pulverization chamber 26a of the pulverization processor 2.

[0075] In contrast, the holding tank 3A disposed in the hydrogen production apparatus 1A is a large-capacity tank formed with a volume 300 times or more the volume of the grinding chamber 26a formed in the grinding vessel 21 of the grinding processor 2. This makes it possible to grind the inorganic material (processing material) in the holding tank 3A uniformly. In this case, the processing time increases in proportion to the processing amount.

[0076] The hydrogen production device 1A of Example 2 configured in this manner is capable of processing large amounts of water by placing a large-capacity tank in the holding tank 3A with a volume more than 300 times the volume of the grinding chamber 26a and using a small media-agitation type wet grinder (grinding processor 2, 5) that operates at a low rated power (e.g., 3.7 kW).

[0077] For example, when using a power source such as small-scale hydroelectric power generation, a fairly stable supply of electricity is provided throughout the day, but the power capacity is limited and it may not be possible to use a large electric motor. In such cases, connecting a large-capacity holding tank 3A to a small media agitation wet pulverizer (pulverizer 2, 5) that operates at a low rated power makes it possible to process large amounts of hydrogen.

[0078] Furthermore, by making the holding tank 3A a large-capacity tank, the grinding speed slows down, making it easy to operate the system while adding alkaline components such as sodium hydroxide to the holding tank 3A. In other words, because a sudden reaction is suppressed, swelling of the slurry does not occur, and solid matter does not adhere to the inside of the holding tank 3A or the grinding processor 2, causing problems in operation.

[0079] The other configurations and effects are substantially the same as those of the above-described embodiment or other examples, and therefore description thereof will be omitted. [Example]

[0080] Hereinafter, a hydrogen production device 1B and a hydrogen production method according to Example 3, which are different from the hydrogen production devices 1 and 1A of the above-described embodiment and Examples 1 and 2, will be described with reference to Fig. 10. Note that the same or equivalent parts as those described in the above-described embodiment or Examples 1 and 2 will be described using the same terms or symbols.

[0081] In the hydrogen production devices 1, 1A of the above-described embodiment and Examples 1, 2, it is assumed that an alkaline component is added to the holding tank 3, 3A to generate hydrogen gas in the holding tank 3, 3A.

[0082] In contrast to this, in the hydrogen production device 1B of the third embodiment, a reaction tank 6 for adding an alkaline component to generate hydrogen gas is provided separately from the holding tank 3B for the pulverization treatment.

[0083] That is, the hydrogen production device 1B of this Example 3 includes a pulverizer 2 which is a media-agitation type wet pulverizer, a holding tank 3B for the inorganic substance (processing material), a circulation line 40, a reaction tank 6 having an addition port 62 for an alkaline component, and a liquid transfer line 70 connected to the circulation line 40 for transferring the processing material to the reaction tank 6. Here, a circulation pump 4 is arranged in the circulation line 40 as needed.

[0084] The holding tank 3B of Example 3 is used only for the pulverization process, and is therefore provided with only an inlet 31 for the slurry to be treated and a return port after circulation. On the other hand, the reaction tank 6 is provided with an inlet 61 for the slurry to be treated, an inlet 62 for adding an alkaline component, an agitator 64, and an outlet 63 for removing hydrogen gas generated in the reaction tank.

[0085] The circulation line 40 and the reaction tank 6 are connected by a liquid transfer line 70, the end of which is connected to a valve 41 that is a branch point of the circulation line 40. A pump 7 is provided midway along the liquid transfer line 70.

[0086] In the hydrogen production method using the hydrogen production device 1B of Example 3 configured as above, first, a pulverization treatment step is carried out for a predetermined time in the circulation line 40. Then, after the set pulverization time has elapsed, the pump 7 is operated to send the treated material slurry to the reaction tank 6 via the liquid delivery line 70.

[0087] Next, in the hydrogen gas generation process, an alkaline component such as sodium hydroxide is added through the addition port 62 of the reaction tank 6, and hydrogen gas is generated while stirring the treated material slurry with the agitator 64. The generated hydrogen gas is then taken out through the discharge port 63.

[0088] The hydrogen production device 1B and hydrogen production method of Example 3 configured as described above have a reaction tank 6 for adding an alkaline component, separate from the holding tank 3B used to cause a mechanochemical reaction between water and an inorganic substance (processing material).

[0089] When sodium hydroxide (alkaline component) is added to the aqueous slurry of pulverized silicon (processed material), it is necessary to add sodium hydroxide at an optimal concentration that matches the particle size (specific surface area) of the silicon. However, it is difficult to accurately determine the particle size in real time during the pulverization process.

[0090] In contrast, only water and silicon are placed in a holding tank 3B for crushing processing, and crushed to the required particle size in a circulation line 40 in which a crushing processing machine 2 is interposed in a neutral or acidic region, producing a fine particle silicon water slurry in which the particle surfaces are activated by a mechanochemical reaction.

[0091] Next, the fine particle silicon water slurry is sent to the reaction tank 6 by switching the valve 41 of the circulation line 40, and sodium hydroxide is added there, thereby making it possible to safely generate large amounts of hydrogen gas and recover high-purity hydrogen gas.

[0092] By separating the crushing process and the hydrogen gas generation process in this way, the next silicon crushing process can be carried out simultaneously using holding tank 3B while hydrogen is being generated in reaction tank 6, making it suitable for continuous production.

[0093] Furthermore, when silicon is crushed in water between the acidic and neutral regions, the amount of hydrogen generated is kept to a minimum, so the pressure-resistant design of the crusher 2 and its associated equipment can be simplified. In other words, hydrogen can be produced continuously, safely, and efficiently.

[0094] The other configurations and effects are substantially the same as those of the above-described embodiment or other examples, and therefore description thereof will be omitted.

[0095] The embodiments and examples of the present invention have been described in detail above with reference to the drawings. However, the specific configurations are not limited to the embodiments or Examples 1-3, and design changes that do not deviate from the gist of the present invention are included in the present invention.

[0096] For example, in the above embodiment or Example 1, the crushing processors 2, 5 in which the ratio (L / D) of the axial length (L) to the diameter (D) of the crushing chambers 26a, 56a is 1 or less have been described as examples, but this is not limited thereto, and a media-agitation type wet crusher in which the L / D is greater than 1 can also be used.

[0097] Furthermore, in the above embodiment or Examples 2 and 3, an alkaline component (alkaline solution) such as sodium hydroxide is added through the addition port 32 of the holding tank 3 or the addition port 62 of the reaction tank 6, but this is not limited to this, and hydrogen gas can also be produced by adding an acid component (acid solution) such as sulfuric acid or nitric acid through the addition ports 32 and 62 and causing a reaction. [Explanation of symbols]

[0098] 1: Hydrogen production equipment 2: Grinding machine (media agitation type wet grinder) 21: Grinding container 22: Supply port 23: Outlet 26a: Grinding chamber 3: Holding tank 32: Addition port 33: Outlet 40: Circulation line 5: Grinding machine (media agitation type wet grinding machine) 51: Grinding container 52: Supply port 53: Outlet 54: Rotation axis 55: Stirring rotor 56a: Grinding chamber 551: Holding plate part 551a:Aperture 552: Stirring section 552a:Through hole 553A, 553B:Protrusion 1A: Hydrogen production equipment 3A: Holding tank 1B: Hydrogen production device 3B: Holding tank 6: Reaction tank 62: Addition port 70: Liquid transfer line

Claims

1. A hydrogen production device that produces hydrogen by causing a mechanochemical reaction between water and an inorganic substance to be treated, a media-agitation wet mill having an agitation rotor disposed inside a cylindrical grinding vessel having a supply port and a discharge port for the material to be processed; a holding tank for the material to be processed by the media-agitation wet grinder; a circulation line for circulating the material to be processed and water between the media-agitation wet pulverizer and the holding tank; The material to be treated is aluminum, iron, titanium, or manganese, The hydrogen generating device is characterized in that the holding tank has an inlet for adding an alkaline component or an acid component and an outlet for discharging hydrogen gas.

2. A hydrogen production device that produces hydrogen by causing a mechanochemical reaction between water and an inorganic substance to be treated, a media-agitation wet mill having an agitation rotor disposed inside a cylindrical grinding vessel having a supply port and a discharge port for the material to be processed; a holding tank for the material to be processed by the media-agitation wet grinder; a circulation line for circulating the material to be processed and water between the media-agitation wet pulverizer and the holding tank; a reaction tank having an addition port for an alkaline component or an acid component; a liquid transfer line connected to the circulation line for transferring the treatment product to the reaction tank, The hydrogen generating device, wherein the material to be treated is aluminum, iron, titanium, or manganese.

3. The hydrogen production device described in claim 1 or 2, characterized in that the stirring rotor comprises a circular plate-shaped retaining plate portion fixed to a rotating shaft and having multiple openings, a cylindrical stirring portion provided on the periphery of the retaining plate portion and having multiple through holes, and a protrusion portion provided on the outer surface of the stirring portion.

4. 4. The hydrogen production device according to claim 3, wherein the media-agitation type wet pulverizer has two agitation rotors arranged on the rotary shaft with a gap therebetween.

5. A hydrogen production method for producing hydrogen by causing a mechanochemical reaction between water and an inorganic substance to be treated, a step of circulating the material to be treated and water between a media-agitation type wet grinder having a cylindrical grinding vessel and a holding tank to perform a grinding treatment; and generating hydrogen gas by adding an alkaline component or an acid component to the holding tank after stopping the circulation of the material to be treated and the water, The hydrogen production method, wherein the material to be treated is aluminum, iron, titanium, or manganese.

Images