JP6563724B2 - HYDROGEN GENERATOR, ITS MANUFACTURING METHOD, AND HYDROGEN GENERATION METHOD - Google Patents

Description

  The present invention relates to a hydrogen generation apparatus including a hydrogen generating agent that reacts with a reaction solution to generate hydrogen and a container that stores the hydrogen generating agent, a manufacturing method thereof, and a hydrogen generation method, and in particular, supplies hydrogen to a fuel cell. It is useful as a technique for

  A fuel cell is an energy source that is attracting attention because it has higher power generation efficiency than other power generation systems and does not generate substances that pollute the atmosphere. In a hydrogen supply type fuel cell, air (oxygen) is supplied to the cathode and hydrogen is supplied to the anode in order to generate power. As one of the methods for generating hydrogen, the main component is a metal hydride compound (for example, sodium borohydride, magnesium hydride, calcium hydride, etc.) that is easy to handle and has a high hydrogen storage amount per unit volume. A method of generating hydrogen by supplying a reaction solution (water or the like) to a hydrogen generator is known.

  When a reaction liquid is supplied from above using a hydrogen generator lump mainly composed of a metal hydride compound, although the initial reactivity is high, by-products such as metal hydroxide generated by the reaction are The upper surface of the hydrogen generating agent is covered, and the contact with the reaction solution is hindered to reduce the reactivity and responsiveness. That is, as shown in FIGS. 13 (a) and 13 (b), as the reaction of hydrogen generation proceeds from (a) to (b), by-products and the like 18 are formed on the surface of the hydrogen generating agent 14. Since the water guide distance D between the existing reaction site 17 and the supplied reaction liquid 19 increases, not only a large amount of the reaction liquid 11 is required, but also the reactivity and responsiveness are lowered.

  Therefore, Patent Document 1 discloses a hydrogen gas generation apparatus that injects water onto a metal hydride at a high pressure in order to remove by-products. However, not only is the structure complicated and an increase in size, such as a device for injecting water at high pressure, is necessary, but a large amount of water is required for injection, which is not a practical method.

  On the other hand, Patent Document 2 discloses a hydrogen generator in which a cylindrical hydrogen generator is installed sideways for the purpose of controlling the amount of hydrogen generated. The cavity inside the cylinder is a liquid supply flow path, and the reaction liquid introduced into the liquid supply flow path penetrates into the reaction layer arranged on the outer periphery of the liquid supply flow path, thereby generating hydrogen. Can do.

JP 2002-137903 A JP 2013-049584 A

  However, the liquid feeding method in Patent Document 2 is different from the apparatus of FIG. 13 in that by supplying a reaction liquid to the cavity inside the cylinder, a by-product is formed with the progress of the reaction and the permeation of the reaction liquid is inhibited. Therefore, there is room for improvement in the utilization efficiency of the reaction solution. In addition, even if the supply of the reaction liquid is stopped, there is a problem that the response speed for stopping the hydrogen generation is slow due to the structure in which hydrogen is generated while the reaction liquid permeates the reaction layer.

  Accordingly, an object of the present invention is to provide a hydrogen generator capable of improving the utilization efficiency of a reaction solution and improving the reactivity and responsiveness of hydrogen generation, a manufacturing method thereof, and a hydrogen generation method.

  The inventors of the present invention have intensively studied to achieve the above-described object, and as a result, the hydrogen generator containing a thermosetting resin and granular metal hydride is housed in a container in a specific shape, thereby solving the problems described above. The inventors have found that this can be solved, and have completed the present invention.

  That is, the hydrogen generator of the present invention is a hydrogen generator comprising a hydrogen generating agent that reacts with a reaction solution to generate hydrogen, and a container that contains the hydrogen generating agent. The hydrogen generating agent includes a thermosetting resin and a granular metal hydride, and is erected with a space along the wall surface of the container. It has the standing part, It is characterized by the above-mentioned. As shown in FIG. 1 (a), the hydrogen generating agent 14 has a structure having a standing portion 14 a erected along the wall surface of the container 15 across the space 13. Is added dropwise to form a reaction site 17 by contacting the supplied reaction solution 19 and the hydrogen generating agent 14, and the hydrogen generation reaction proceeds. In addition, although the case of a bottomed cylindrical hydrogen generating agent is shown in FIG. 1, a similar effect can be obtained even when there is no bottom. According to the hydrogen generator, this characteristic structure can improve the utilization efficiency of the reaction solution from the following two viewpoints, and can also improve the reactivity and responsiveness of hydrogen generation.

  First, as shown in FIGS. 1 (a) and 1 (b), the hydrogen generator of the present invention proceeds from (a) to (b) while the reaction site 17 rises. The reactivity and responsiveness of hydrogen generation can be greatly improved. Specifically, the by-product such as a metal hydroxide generated during the hydrogen generation reaction 18 has a volume expansion, and therefore has a large action of collapsing the resin base material, and the metal hydroxide and the like absorb water. Therefore, the reaction proceeds from (a) to (b), and the space 13 is buried by a by-product 18 (reacted hydrogen generator, etc.). As a result, the reaction site 17 moves (rises) toward the supply unit 12, so that it can always react with the reaction liquid 19 supplied with the unreacted portion of the hydrogen generating agent 14 via the reaction site 17. . As a result, it is possible to suppress a decrease in reactivity and responsiveness due to an increase in the water conveyance distance D as in the prior art (FIG. 13), and high reactivity and responsiveness can be realized. In this specification, responsiveness is not only the initial responsiveness of the hydrogen generation reaction (goodness of rising immediately after the start of the reaction in FIG. 7 and the like), but also when the supply of the reaction liquid is stopped or when restarting. It is a concept that includes responsiveness.

  Second, since the hydrogen generator of the present invention can use not only the reaction solution but also the steam generated by the reaction at the time of hydrogen generation, it uses the water that has been conventionally discharged as water vapor. Thus, the utilization efficiency of the reaction solution can be greatly improved. Specifically, when a small amount of reaction liquid is supplied to the reaction site, hydrogen is generated and water vapor is generated by reaction heat. Since the generated water vapor comes into contact with the surface of the unreacted hydrogen generator, hydrogen can be efficiently generated with a small amount of the reaction liquid, and the utilization efficiency of the reaction liquid can be greatly improved. In addition, as shown to Fig.1 (a) and (b), the flow of the water vapor | steam which the dotted line arrow generate | occur | produced is shown. In addition, even when the reaction proceeds, it is designed such that an unreacted hydrogen generator always exists above the reaction site, so that the reaction can be maintained with high efficiency.

  The hydrogen generating agent in the present invention preferably has a cylindrical upright portion. Such a shape is advantageous in realizing the operational effects of the present invention because the handling property is high, the reaction solution can be easily supplied, and the reaction of hydrogen generation can be controlled more efficiently.

  In the above, the hydrogen generating agent is preferably a bottomed cylindrical shape. With such a shape, a hydrogen generating agent is also formed on the bottom surface, and the reaction solution can be directly dropped onto the reaction site, so that the reaction of hydrogen generation can be controlled more quickly and efficiently. This is advantageous in realizing the effect.

  The hydrogen generator in the present invention preferably has voids. Thereby, since the surface area per volume of the hydrogen generating agent is increased, the reactivity with steam or the like can be improved. Furthermore, as the reaction progresses, the space below the reaction site is buried with the reacted hydrogen generator, and even in the final stage when the unreacted portion of the hydrogen generator is reduced, the vapor passes through the gap. Thus, the reaction can be efficiently performed to the end. Further, even if the height of the standing portion is designed to be low, it is possible to use the steam efficiently with a small volume, so that the hydrogen generator can be downsized.

  In the above, it is preferable that the hydrogen generating agent is formed by binding granular, granular, pellet-like, rod-like, or spherical granules. As a result, the hydrogen generating agent can be produced efficiently and the porosity can be easily optimized, which is advantageous in realizing the above-described effects.

  The hydrogen generator in the present invention preferably further contains a hydrophilic polymer. When the present inventors examined, when it did not contain a hydrophilic polymer, it turned out that the shape change of the resin base material arises by the viscosity fall of the uncured thermosetting resin at the time of thermosetting. In such a state, the shape of the designed hydrogen generating agent cannot be maintained, the density of the hydrogen generating agent becomes uneven, the space surrounded by the standing part is buried, hydrogen generation occurs Instability of behavior occurs. Therefore, the present inventors examined the inclusion of a hydrophilic polymer. As described above, when the hydrophilic polymer is further contained, the viscosity is increased because the hydrophilic polymer is simultaneously melted when the hydrogen generator is thermally cured. Thereby, the designed shape can be maintained as it is, and the shape maintenance characteristic at the time of shaping | molding can be improved.

  Furthermore, from another viewpoint, it is preferable that the hydrogen generator contains a hydrophilic polymer. When the hydrophilic polymer was not contained, it was difficult to freely set the blending ratio of the thermosetting resin and the metal hydride due to the influence of fluidity (moldability). That is, the reaction rate of hydrogen generation depends on the ratio between the thermosetting resin and the metal hydride, and it is difficult to set the blending ratio freely. However, by including a hydrophilic polymer, it acts as a thickener to improve moldability, so that the blending ratio of thermosetting resin and metal hydride can be changed relatively freely. became. Thereby, the mixture ratio matched with the target reaction rate can be selected easily.

  The hydrogen generator in the present invention has a two-layer structure of an upper part and a lower part, and the content of the metal hydride contained in the upper part is lower than the content of the metal hydride contained in the lower part. It is preferable. With a two-layer structure having such a content ratio, a hard layer that does not easily collapse can be formed on the upper portion, so that collapse due to vibration or the like can be suppressed and contribution to stabilization of reactivity can be achieved. Further, it becomes difficult for an unreacted portion to remain on the container side on the bottom surface of the standing portion of the hydrogen generating agent, and hydrogen can be generated more efficiently. In addition, it is possible to suppress the preceding reaction due to excessive steam and contribute to stabilization of reactivity.

  The metal hydride in the present invention is preferably calcium hydride. Thus, when it is calcium hydride, the reactivity with water etc. becomes high, and even if the content of calcium hydride is low, the reactivity is high and a practical amount of hydrogen can be generated. Calcium hydride reacts with water and the like to produce calcium hydroxide. In this case, volume expansion occurs. Therefore, the action of the present invention is great because the resin base material is greatly disintegrated and has water absorption. It is advantageous in realizing.

  In the above, the content of metal hydride is preferably 10 to 80% by weight. Within such a range, the progress of the reaction can be stabilized while generating a practical amount of hydrogen.

  In the above, it is preferable that the thermosetting resin is an epoxy resin. When such a resin is used, it is possible to have an appropriate hardness while dispersing the particulate metal hydride, so that a more suitable structure is obtained when the hydrogen generation reaction proceeds.

  In the above, the hydrophilic polymer is preferably polyoxyalkylene glycol. Thereby, the shape maintenance characteristic at the time of molding can be improved more reliably, and the design according to the target reaction speed can be more freely performed.

  In the above, the content of the hydrophilic polymer is preferably 2 to 25% by weight. Within such a range, the shape maintaining characteristics and ease of design during molding can be further optimized while the reaction proceeds moderately.

  On the other hand, the method for producing a hydrogen generator of the present invention is a method for producing a hydrogen generator comprising a hydrogen generator that generates hydrogen by reacting with a reaction solution, and a container that contains the hydrogen generator. Preparing a container having a supply part for supplying a reaction liquid to a reaction site, and a mixture containing an uncured thermosetting resin, a hydrophilic polymer and a granular metal hydride in the container. The method includes a step of standing along a wall surface with a space therebetween, and a step of forming a standing portion by heating and curing the mixture. According to the method for producing a hydrogen generator of the present invention, a hydrogen generator capable of improving the utilization efficiency of the reaction solution and improving the reactivity and responsiveness can be produced by a simpler method.

  On the other hand, the hydrogen generation method of the present invention includes a step of supplying hydrogen to the reaction site from the supply unit and generating hydrogen while raising the reaction site to the supply unit side. According to the hydrogen generation method of the present invention, it is possible to react with an unreacted hydrogen generating agent while the reaction site moves toward the supply unit. As a result, it is possible to suppress a decrease in reactivity and responsiveness due to an increase in the water conveyance distance as in the past, and to realize high reactivity and responsiveness.

  Moreover, it is preferable to include the process of generating hydrogen using the water vapor | steam produced when a reaction liquid is supplied to the reaction site from the said supply part. Accordingly, by using not only the reaction solution but also the vapor generated by the reaction of hydrogen generation, hydrogen can be generated with only a small amount of the reaction solution, so that the utilization efficiency of the reaction solution can be greatly improved. Further, even when the reaction proceeds, an unreacted hydrogen generator always exists above the reaction site, so that the reaction with high efficiency can be continued.

It is a schematic diagram which shows the mechanism of hydrogen generation in the hydrogen generator of this invention. It is a figure which shows this embodiment of the hydrogen generator of this invention, (a) is a longitudinal cross-sectional view, (b) is a cross-sectional view of (a). It is a figure which shows this embodiment in case the hydrogen generating agent in this invention is granular, (a) is a longitudinal cross-sectional view, (b) is a cross-sectional view of (a). It is a figure which shows this embodiment in case the hydrogen generating agent in this invention is a 2 layer structure, (a) is a longitudinal cross-sectional view, (b) is a schematic diagram which shows the mechanism of hydrogen generation. It is a figure which shows other embodiment of the hydrogen generator of this invention, (a) is a longitudinal cross-sectional view, (b) is a cross-sectional view of (a). (A)-(d) is a cross-sectional view which shows other embodiment of the hydrogen generator of this invention. It is a graph which shows the hydrogen generation rate (flow rate) etc. in this embodiment etc. (Example 1 and Comparative Example 1) of the hydrogen generator of this invention. It is a graph which shows the water utilization efficiency in this embodiment etc. (Example 1 and Comparative Example 1) of the hydrogen generator of this invention. It is a graph which shows the hydrogen generation speed (flow rate) etc. in other embodiment etc. (Example 2 and Example 3) of the hydrogen generator of this invention. It is a graph which shows the water utilization efficiency in other embodiment etc. (Example 2 and Example 3) of the hydrogen generator of this invention. It is a graph which shows the hydrogen generation speed (flow rate) in other embodiment etc. (reference experiment examples 1 and 2) of the hydrogen generator of this invention. It is a graph which shows the water utilization efficiency in other embodiment etc. (reference experiment examples 1 and 2) of the hydrogen generator of this invention. It is a schematic diagram which shows the mechanism of hydrogen generation in the conventional hydrogen generator.

  In the embodiment of the hydrogen generator of the present invention, there is another embodiment in which the hydrogen generating agent has a bottomed cylindrical shape and the embodiment is different from the present embodiment. Hereinafter, the description will be divided into each embodiment. Note that in some or all of the drawings, portions that are not necessary for the description are omitted, and there are portions that are illustrated in an enlarged or reduced manner for ease of description. The terms indicating the positional relationship such as up and down are merely used for ease of explanation, and are not intended to limit the configuration of the present invention.

<This embodiment of the hydrogen generator>
FIG. 2 is a view showing the present embodiment, which is an example of a preferred embodiment, in the hydrogen generator of the present invention, where (a) is a longitudinal sectional view and (b) is a transverse sectional view of (a). As shown in FIGS. 2A and 2B, the hydrogen generator of the present invention includes a hydrogen generating agent 14 that generates hydrogen by reacting with the reaction liquid 11 and a container 15 that contains the hydrogen generating agent 14. Prepare. The hydrogen generating agent 14 has a standing portion 14 a and a bottom surface portion 14 b that are erected along the wall surface of the container 15 with a space 13 therebetween, and the container 15 supplies the reaction solution 11 to the reaction site 17. Supply section 12 for In the present embodiment, the hydrogen generating agent 14 has a bottomed cylindrical shape. With such a shape, the reaction solution 11 can be directly dropped onto the bottom surface portion 14b, so that the reaction of generating hydrogen can be controlled more quickly and efficiently, and the utilization efficiency of the reaction solution can be improved. And responsiveness can be improved.

  In the above, the occupation ratio of the hydrogen generating agent in the cross-sectional view (the occupied area of the hydrogen generating agent in the cross-sectional view / the occupied area of the container in the cross-sectional view × 100) is preferably 10% to 75%, preferably 15% to 60 % Is more preferable, and 15% to 45% is more preferable. In such a range, the space can be buried with a by-product (reacted hydrogen generator), so that the reaction site moves (rises) to the supply side, while the hydrogen generator It can react with the reaction liquid supplied with the unreacted part via the reaction site.

  When the hydrogen generating agent is cylindrical, the ratio (Da / Db) of the inner diameter Da of the hydrogen generating agent 14 to the outer diameter Db of the hydrogen generating agent 14 is Da / Db = 0.05 to 0.8. Is preferable, Da / Db = 0.10 to 0.7 is more preferable, and Da / Db = 0.15 to 0.45 is still more preferable. In such a range, the space can be buried with a by-product (reacted hydrogen generator), so that the reaction site moves (rises) to the supply side, while the hydrogen generator It can react with the reaction liquid supplied with the unreacted part via the reaction site.

  As shown in FIGS. 3A and 3B, the hydrogen generating agent 14 in the present invention preferably further has a gap 21. As shown in FIG. 3, the shape of the hydrogen generating agent 14 having the voids 21 is preferably a shape in which granular granules are bound to each other. Thereby, since the surface area per volume of the hydrogen generating agent 14 increases, the reactivity with steam and the like can be improved. Furthermore, as the reaction proceeds, the space 13 is buried with a reacted hydrogen generator and the like, and even in the final stage when the unreacted portion of the hydrogen generator 14 is reduced, by allowing the vapor to pass through the gap 21, It is possible to react efficiently until the end.

  In order to have the voids 21, it is possible to control the production method of the hydrogen generating agent 14 so as to have bubbles, but the hydrogen generating agent 14 is formed into granules, pellets, rods, or spherical granules. It can also control to have the space | gap 21 by setting it as the shape bound mutually. Moreover, it can also control to have a space | gap by setting it as the pleated hydrogen generating agent which bends the sheet-like or sheet-like hydrogen generating agent alternately.

  The ratio of voids to the total volume of the hydrogen generating agent 14 (porosity (%) = (theoretical volume density−actual volume density) / theoretical volume density × 100) is 0 to 80% from the viewpoint of reactivity with steam and the like. Is preferable, and 50 to 70% is more preferable.

  As shown in FIG. 4, the hydrogen generating agent 14 in the present invention has a two-layer structure of an upper part 14c and a lower part 14d, and the content x of the metal hydride contained in the upper part 14c is in the lower part 14d. The content of the metal hydride contained is preferably lower than the content y. With such a two-layer structure, a hard layer that does not easily collapse can be formed on the upper portion 14c, so that collapse due to vibration or the like can be suppressed and contribution to stabilization of reactivity can be achieved. In addition, the preceding reaction due to excessive steam can be suppressed, and high reactivity can be maintained stably even at the end of the reaction. Furthermore, in general, with a one-layer structure, the unreacted portion 20 tends to remain as an unreacted portion as the hydrogen generation reaction proceeds. However, as shown in FIG. It becomes difficult for the reaction part 20 to remain, and hydrogen can be generated more efficiently.

  In the above, the ratio of the height Ha of the upper portion 14c and the height Hb of the lower portion 14d is preferably Ha: Hb = 1: 1 to 1:10, and Ha: Hb = 1: 1, from the viewpoint of suppressing the collapse due to vibration or the like. 2 to 1: 8 is more preferable.

  The container contains a hydrogen generating agent that reacts with the reaction solution to generate hydrogen. The container includes a supply unit for supplying the reaction solution to the reaction site. As the container, a sealed container is used, but a container that can be sealed when the hydrogen generating agent is accommodated is preferable. Note that, as the reaction vessel, alkali may be generated by the reaction of the hydrogen generating agent, and therefore, a material having alkali resistance is preferably used.

  The volume of the container is preferably 1.2 to 3 times the volume of the hydrogen generating agent and 1.5 to 2 times from the viewpoint of reducing the initial amount of air while taking into account the expansion of the hydrogen generating agent during the reaction. More preferred.

The dropping method of the reaction liquid in the hydrogen generator of the present invention is not particularly limited as long as the dropping amount of the reaction liquid can be limited, but the method for controlling the dropping amount using a liquid delivery device such as a pump, in the container There are a method of adjusting the dripping amount by the pressure difference, and a method of adjusting and controlling the head height by using the weight. From the viewpoint of precisely controlling the amount of dripping, it is preferable to use a method of controlling the amount of dripping using a liquid delivery device such as a pump.
Moreover, it is also possible to supply a reaction liquid using a water absorbing sheet, sponge, etc. The water-absorbing sheet or the like is a sheet-like material having water absorption, for example, a porous sheet using a hydrophilic material, or a porous body such as a columnar hydrophilic sponge. It is done. Specifically, it is preferable to use a water conducting body such as a water absorbent nonwoven fabric, a water absorbent woven fabric, a water absorbent paper, a filter paper, or the like. Further, these can be used together or in combination with a water absorbent resin. In addition, the water absorbing sheet may be a roll of a long object.

  In the present invention, a hydrogen discharge channel for discharging generated hydrogen may be provided, or the hydrogen discharge channel may be connected to the container separately from the supply unit. In the present invention, a safety valve may be provided in the hydrogen discharge channel or the like. In this case, any safety valve can be used as long as it releases the gas at a certain pressure or higher. From the viewpoint of reducing the size and weight, it is preferable to use a valve such as an umbrella type, a duckbill type, or a metal ball valve type as the safety valve. The set pressure of the safety valve is determined according to the pressure resistance of the system, but is set to about 30 to 500 kPa, for example.

<Hydrogen generator>
The hydrogen generator in the present invention contains a thermosetting resin and a granular metal hydride. Examples of the metal hydride include calcium hydride, lithium hydride, sodium hydride, potassium hydride, lithium aluminum hydride, sodium aluminum hydride, magnesium hydride, barium hydride, beryllium hydride, or strontium hydride. Although it can be used, the metal hydride is preferably calcium hydride from the viewpoint of improving the reactivity with water or the like. In addition to the metal hydride, a metal such as aluminum, iron, magnesium, or calcium, a metal hydride complex compound such as sodium borohydride, or the like may be contained as a hydrogen generating substance.

As the hydrogen generating agent, those containing granular calcium hydride (CaH ₂ ) in the resin base material are particularly preferable. The granular calcium hydride is dispersed or embedded in the resin matrix, thereby suppressing the reactivity of the calcium hydride and improving the handleability during the reaction with water. In addition, since volume expansion occurs due to a reaction product (calcium hydroxide) generated when reacting with water or the like, the action of collapsing the resin base material is increased, and the reaction with water or the like easily proceeds to the inside naturally. . Moreover, since calcium hydroxide has water absorption, it is advantageous in burying the space between the standing portions as the reaction proceeds.

  The content of the metal hydride is preferably 40 to 90% by weight in the hydrogen generating agent. From the viewpoint of collapsing the resin base material during the reaction while generating a highly reactive and practical amount of hydrogen gas. In the hydrogen generator, it is more preferably 50 to 85% by weight, and still more preferably 60 to 75% by weight. Even when the hydrogen generating agent has a two-layer structure of an upper part and a lower part as described above, it is preferable that both the upper part and the lower part have a content of metal hydride within the above range.

  As described above, when the hydrogen generating agent has a two-layer structure of the upper part and the lower part, the content of the hydrogenation metal content x contained in the upper part 14c with respect to the content y of the hydrogenation metal contained in the lower part 14d. The ratio (x / y) is preferably x / y = 0.3 to 0.99, more preferably x / y = 0.5 to 0.95, from the viewpoint of more efficiently generating hydrogen. More preferably, y = 0.6 to 0.9.

  The average particle diameter of the metal hydride is preferably 1 to 100 μm, more preferably 6 to 30 μm, and still more preferably 8 to 10 μm, from the viewpoint of appropriately promoting dispersibility in the resin base material and reaction.

  The content of the hydrogen generating substance other than the metal hydride is preferably 0 to 20% by weight, more preferably 0 to 10% by weight, and still more preferably 0 to 5% by weight in the hydrogen generating agent. The average particle size of the hydrogen generating material other than the metal hydride is preferably the same as that of the metal hydride.

  As the resin used as the base material, a thermosetting resin is used from the viewpoint that the resin base material easily collapses during the reaction, and may further contain a thermoplastic resin, a heat-resistant resin, or the like. Examples of the thermosetting resin include an epoxy resin, an unsaturated polyester resin, a phenol resin, an amino resin, a polyurethane resin, a silicone resin, or a thermosetting polyimide resin, and the resin base material is appropriately collapsed during hydrogen generation. From the viewpoint of having properties, an epoxy resin is preferable. When the thermosetting resin is cured, a curing agent, a curing accelerator, or the like is appropriately used as necessary.

  Examples of the thermoplastic resin include polyethylene, polypropylene, polystyrene, acrylic resin, fluororesin, polyester, and polyamide. In addition, examples of the heat resistant resin include aromatic polyimide, polyamide, or polyester.

  The content of the thermosetting resin is preferably less than 40% by weight, but from the viewpoint of collapsing the resin base material during the reaction while maintaining the shape retention, 5 to 35% by weight in the hydrogen generator. 10 to 30% by weight is more preferable.

The hydrogen generator in the present invention preferably further contains a hydrophilic polymer. Thereby, when hardening a hydrogen generating agent, the designed shape can be maintained as it is, and the shape maintenance characteristic at the time of shaping | molding can be improved. In addition, by containing a hydrophilic polymer, the mixing ratio of the thermosetting resin and the metal hydride can be changed relatively freely, and the mixing ratio according to the target reaction rate can be easily achieved. You can choose.
The hydrophilic polymer in the present invention is generally a polymer compound that is easily dissolved, swelled or wetted in water. The hydrophilic polymer has a dissociating group such as a carboxyl group, a sulfone group, or an amino group, or a nonionic hydrophilic group such as a hydroxyl group, an amide group, an ether group, or a polyoxyethylene group in the molecular structure. Contains polymers. The hydrophilic polymer is not particularly limited and may be a synthetic polymer or a naturally derived polymer. The hydrophilic polymer may have the appropriate hydrophilic functional group and may have a cross-linked chain as necessary. The hydrophilicity can be adjusted by a known method of introducing a hydrophobic group or crosslinking.

  The synthetic polymer is not particularly limited, and examples thereof include water-soluble resins, acrylic resins having the hydrophilic group, polyester resins, amine resins, and modified polyvinyl alcohol resins.

  Examples of the naturally-derived polymer include polysaccharides such as chitin, chitosan, gum arabic, alginic acid, carrageenan, agar, chitansan gum, gellan gum, cellulose, xylose, starch, pullulan, or pectin, and proteins such as keratin, collagen, and silk. Etc. In addition, semi-synthetic polymers that are hydrophilized, polyethylene glycolized, hydrophobized, or three-dimensionalized by performing hydrolysis or cross-linking reaction or the like on these naturally-derived polymers are included as necessary.

  The hydrophilic polymer includes a water-soluble polymer. In the present invention, it is preferable to contain a water-soluble polymer from the viewpoint of freely designing the reaction rate and from the viewpoint of improving the shape maintenance performance at the time of molding.

  The water-soluble polymer is a polymer compound composed of a water-soluble synthetic polymer and a natural polymer. Examples of the synthetic polymer include an initial condensate such as a resole resin, a urea resin, or a melamine resin, a nonionic polymer such as polyvinyl alcohol, polyethylene glycol, polyacrylamide, or polyvinyl pyrrolidone, acrylic acid, methacrylic acid, and the like. Homo or copolymers with esters are included. Examples of the natural polymer include starch, dextrin, carrageenan, guar gum, and xanthan gum. In addition, semi-synthetic polymers that have been converted to polyethylene glycol or the like by performing hydrolysis or cross-linking reaction or the like on these naturally-derived polymers are included as necessary.

  In the present invention, polyoxyalkylene glycol is preferred from the viewpoint of ensuring appropriate hydrophilicity and a practical amount of hydrogen generation, and polyethylene glycol, polyethylene glycol and copolymers thereof (for example, polyethylene glycol-polypropylene glycol copolymer). Coalescence) is more preferred. In addition, even a thing with low water solubility like polypropylene glycol can be used.

  The hydrophilic polymer may be a copolymer having two or more monomers as structural units. An alternating copolymer in which repeating units are arranged alternately, a block copolymer in which repeating units of the same type are long and continuous, and branches consisting of other types of repeating units are connected to the trunk consisting of one type of repeating unit. In the present invention, a random copolymer is preferably used. However, in the present invention, a random copolymer having a random repeating unit is used.

  The content of the hydrophilic polymer is preferably 2 to 30% by weight, more preferably 2 to 25% by weight, and still more preferably 3 to 20% by weight from the viewpoint of improving the shape maintaining property at the time of molding.

  The molecular weight of the polyoxyalkylene glycol is preferably from 20,000 to 6.5 million, preferably from 100,000 to 5,000,000 from the viewpoint of appropriately promoting the dispersibility in the resin matrix and the reaction of hydrogen generation. More preferred.

  The melting point (Tm) of the hydrophilic polymer is not particularly limited as long as it is a temperature that exhibits fluidity when thermosetting the thermosetting resin, but is lower than the temperature at the time of thermosetting. Is preferable, 40 to 120 ° C. is more preferable, and 50 to 80 ° C. is more preferable. Thereby, the hydrophilic polymer melts at the time of thermosetting, and the fluidity (viscosity) can be increased, so that the designed shape of the hydrogen generating agent can be maintained.

The hydrogen generator in the present invention may contain other components such as a catalyst and a filler as optional components other than the above components. As the catalyst, an alkali compound such as sodium hydroxide, potassium hydroxide and calcium hydroxide is also effective in addition to the metal catalyst for the hydrogen generator.
Examples of the filler include colorants such as titanium oxide and carbon black, metal powders such as ferrite, inorganic fibers such as glass fibers and metal fibers, organic fibers such as carbon fibers and aramid fibers, aluminum nitride, boron nitride, water Heat transfer agents such as aluminum oxide, alumina, magnesium oxide, carbon nanotubes, expanded graphite, glass beads, glass balloons, glass flakes, glass fibers, asbestos, calcium carbonate, magnesium carbonate, potassium titanate whiskers, zinc oxide whiskers, etc. Examples include inorganic whiskers, talc, silica, calcium silicate, kaolin, diatomaceous earth, montmorillonite, graphite, pumice, evo powder, cotton flock, cork powder, barium sulfate, and fluororesin. Glass fiber, glass beads, talc, and silica are preferable from the viewpoint of improving viscosity. These may be used alone or in combination of two or more.

<Method for producing hydrogen generator>
The hydrogen generator of the present invention comprises the production method of the present invention, that is, a step of preparing the container having a supply part for supplying a reaction solution to a reaction site, an uncured thermosetting resin, and a hydrophilic polymer. And a step of standing the mixture containing the granular metal hydride along the wall surface of the container with a space therebetween, and a step of forming the standing portion by heating and curing the mixture. Manufactured by. The mixture can contain components such as other components and curing agents described above.

  In the step of standing the mixture, it is particularly important to use a mixture containing a hydrophilic polymer from the viewpoints of improving the shape-maintaining characteristics at the time of molding and designing the reaction rate.

  In the step of standing the mixture, a mixture containing an uncured thermosetting resin, a hydrophilic polymer, and a granular metal hydride is spread on the bottom surface of the container, and then the mixture is moved along the wall surface of the container. Therefore, it is preferable to stand with a space. In the case of forming the bottom portion, the hydrogen generating agent has a bottomed cylindrical shape. As a result, the hydrogen generation reaction can be controlled more quickly, which is advantageous in realizing the effects of the present invention. In addition, although it is preferable to form a standing part after forming a bottom part, it is also possible to form a bottom part after forming a standing part.

  In the present invention, it is preferable to further include a step of granulating a mixture containing an uncured thermosetting resin, a hydrophilic polymer and a granular metal hydride. Thereby, the surface area per volume can be expanded and reaction efficiency can be raised. In addition, it is preferable that a granulation process is implemented before the process of standing up a mixture. The granulation method is not particularly limited. For example, rolling granulation method, stirring granulation method, fluidized bed granulation method, compression molding method, film forming method, magnetic property processing method, surface modification method, sintering molding Any of a method, a vibration molding method, a pressure swing method, a vacuum molding method and the like may be used. The granulation can be performed using a known or commercially available granulator. The granulated product can be adjusted in particle size and shape within a range of about 4 to 10φ.

In the process of forming the cured standing portion, it is possible to form the standing portion by installing the already cured standing portion in the container, but from the viewpoint of manufacturing efficiency, the uncured standing portion is It is preferable to cure the entire container after it is formed in the container. Moreover, when the hydrogen generating agent has a bottomed cylindrical shape as described above, it is preferable that the entire container is cured after the bottom surface portion and the standing portion are installed in the container.
The curing temperature for curing the mixture by heating is preferably 40 ° C to 150 ° C, more preferably 60 ° C to 120 ° C, and still more preferably 80 ° C to 100 ° C. In such a range, the viscosity can be adjusted by melting the hydrophilic polymer, so that the shape maintaining performance at the time of molding can be improved.

  In the hydrogen generation method of the present invention, hydrogen is generated by bringing a hydrogen generator and a reaction solution into contact with each other in the hydrogen generator as described above. The hydrogen generation method of the present invention includes a step of supplying hydrogen to the reaction site from the supply unit and generating hydrogen while raising the reaction site to the supply unit side. According to the hydrogen generation method of the present invention, it is possible to react with an unreacted hydrogen generating agent while the reaction site moves toward the supply unit. As a result, it is possible to suppress a decrease in reactivity and responsiveness due to an increase in the water conveyance distance as in the past, and to realize high reactivity and responsiveness.

  Moreover, it is preferable to include the process of generating hydrogen using the water vapor | steam produced when a reaction liquid is supplied to the reaction site from the said supply part. Thus, by using not only the reaction solution but also the vapor generated by the reaction at the time of hydrogen generation, hydrogen can be generated with only a small amount of the reaction solution, so that the utilization efficiency of the reaction solution can be greatly improved. Further, even when the reaction proceeds, an unreacted hydrogen generator always exists above the reaction site, so that the reaction with high efficiency can be continued.

  Examples of the reaction solution used for hydrogen generation include water, an acid aqueous solution, and an alkaline aqueous solution. The temperature of the reaction solution to be supplied may be room temperature, but may be heated to 30 to 80 ° C.

  Although the reaction liquid used for hydrogen generation may be directly discharged to the hydrogen generating agent, the reaction liquid may be supplied to the hydrogen generating agent through a water-absorbing material. Examples of the water absorbent include filter paper, water absorbent sheet, felt, absorbent cotton, and water absorbent resin.

  Although it is possible to adjust the dropping amount of the reaction solution according to the amount of hydrogen gas to be generated, since the reaction rate is controlled, hydrogen can be generated at an appropriate generation rate. Therefore, in the hydrogen generation method of the present invention, hydrogen can be generated at an appropriate generation rate without dripping excessive reaction liquid. It is also possible to adjust the hydrogen generation rate by changing the amount of immersion in the reaction solution. In addition, it is possible to adjust the hydrogen generation rate by covering a part of the surface of the hydrogen generating agent with a non-permeable material of the reaction solution.

  Since the hydrogen generator of the present invention can be reduced in size and simplified, it is particularly effective when used in a hydrogen supply device of a fuel cell.

<Other Embodiments of Hydrogen Generator>
Another embodiment of the present invention is different from the present embodiment only in the shape of the hydrogen generating agent. In the other embodiment 1, as shown in FIGS. 5A and 5B, the hydrogen generating agent 14 in the present invention has a cylindrical standing portion 14a. Such a shape is advantageous in realizing the effects of the present invention because the handling property is high, the reaction liquid 11 can be easily supplied, and the reaction of hydrogen generation can be controlled more efficiently.

  In another embodiment 2, as shown in FIG. 6, the hydrogen generating agent 14 according to the present invention has an upright portion 14 a formed in a U-shape so as to surround the space 13 in the cross-sectional view of FIG. ing. In the transverse sectional view of (b), a plate-like standing portion 14 a is formed so as to sandwich the space 13. In the cross-sectional view of (c), the space 13 is filled by standing a plurality of columnar standing portions 14 a inside the container 15. In the transverse sectional view of (d), a plurality of sheet-like standing portions 14 a are formed so as to sandwich the space 13. The shape of each hydrogen generating agent is not particularly limited as long as it is a structure in which the space is buried and the reaction site can be raised as the reaction proceeds, and has a shape other than the above (a) to (d). Is also possible. Moreover, each hydrogen generating agent can have a bottom face part other than the standing part 14a.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail using an Example, this invention is not limited to a following example, unless the summary is exceeded.

Example 1
<Preparation of container>
A 2 L airtight polypropylene container (manufactured by Sampleratech, SAN2047, trunk diameter 116 mm) was prepared. Note that a supply part for supplying the reaction liquid and a hydrogen discharge channel for discharging the generated hydrogen were prepared in the lid part of the container.

<Preparation of mixture>
165 g of uncured bisphenol A type epoxy resin (Mitsubishi Chemical Co., Ltd., jER828), dicyandiamide type curing agent (Mitsubishi Chemical Co., Ltd., DICY7) 19.8 g, and modified aliphatic (tertiary amine) curing accelerator (Mitsubishi Chemical Co., Ltd.) Manufactured by jER3010, trisdimethylaminomethylphenol) and mixed with a centrifugal stirrer (manufactured by Photochemical Co., Ltd., SK-1100) at a rotational speed of 2000 rpm for 3 minutes. Further, 490 g of CaH ₂ (manufactured by Nippon Heavy Chemical Industry) and 23.3 g of polyethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd., molecular weight 5 million, melting point Tm 65 ° C.) and 7 g of glass fiber (manufactured by Nittobo Co., Ltd., 3 mm) were added and centrifuged. The mixture was prepared with a stirrer at a rotation speed of 2000 rpm for 3 minutes.

<Preparation of granulated product>
The obtained mixture was put into a granulator (manufactured by Kai Brand Co., Ltd., DK0580, diameter 4φ) and extruded to obtain a granular granulated product.

<Production of hydrogen generator>
First, 50 g of the granulated product was weighed out and placed so as to be spread over the bottom surface of the prepared container, and a bottom surface portion of the hydrogen generating agent was prepared so as to have a cylindrical shape with a thickness of about 5 mm. Next, a cylindrical rod (made of nylon) having a diameter of 70 mm and a height of 210 mm is put into a container with a hydrogen generator on the bottom surface so that it stands vertically from the container mouth. Fixed. Thereafter, 590 g of the granulated material was placed in a portion other than the rod so as to produce a cylindrical standing portion. Subsequently, the whole container is put in a drier (100 ° C. setting) in the above state, heated and cured for about 1.5 hours, and a bottomed cylindrical hydrogen generator (height 160 to 160) as shown in FIG. A hydrogen generator having an outer diameter of about 170 mm, an outer diameter of 116 mm, and an inner diameter of 70 mm was manufactured.
In addition, the ratio (weight ratio) of each content of the hydrogen generating agent in the obtained hydrogen generator was epoxy resin: polyethylene glycol: CaH ₂ = 27: 3: 70. Moreover, the porosity of the hydrogen generating agent in the obtained hydrogen generator was about 60%.

Example 2
A hydrogen generator was manufactured under the same conditions as in Example 1.

Example 3
In Example 2, the hydrogen generator was made into a two-layer structure of an upper part and a lower part (see FIG. 4), and a hydrogen generator was produced under the same conditions as in Example 2 except that each hydrogen generator was produced as follows. did.

Specifically, 110 g of uncured bisphenol A type epoxy resin (Mitsubishi Chemical Corporation, jER828), dicyandiamide-based curing agent (Mitsubishi Chemical Corporation, DICY7) 13.2 g, and modified aliphatic (tertiary amine) curing acceleration 1.10 g of an agent (Mitsubishi Chemical Co., Ltd., jER3010, trisdimethylaminomethylphenol) was added and mixed for 3 minutes at a rotational speed of 2000 rpm with a centrifugal stirrer (Photochemical Co., Ltd., SK-1100). Furthermore, 380 g of CaH ₂ (manufactured by Nippon Heavy Chemical Industry), polyethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd., molecular weight 5 million, melting point Tm 65 ° C.) 15.6 g, and glass fiber (manufactured by Nittobo Co., Ltd., 3 mm) 4.68 g were added. The mixture 1 for the lower part was prepared with a centrifugal stirrer at a rotational speed of 2000 rpm to prepare a lower mixture 1 (the proportion of each content (weight ratio) was epoxy resin: polyethylene glycol: CaH ₂ = 24: 3: 73. ).
In the same procedure, 55.0 g of bisphenol A type epoxy resin (Mitsubishi Chemical Corporation, jER828), dicyandiamide curing agent (Mitsubishi Chemical Corporation, DICY7) 6.61 g, and modified aliphatic (tertiary amine) curing accelerator (Mitsubishi Chemical Co., Ltd., jER3010, trisdimethylaminomethylphenol) 0.55 g was added, mixed with a centrifugal stirrer (Photochemical Co., SK-1100) for 3 minutes at a rotational speed of 2000 rpm, and further CaH _2. 130 g (manufactured by Nippon Heavy Chemical Industry) and 7.78 g of polyethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd., molecular weight 5 million, melting point Tm65 ° C.), 2.33 g of glass fiber (manufactured by Nittobo Co., Ltd., 3 mm) are added, and a centrifugal stirrer Thus, the mixture 2 for the upper part was prepared at a rotational speed of 2000 rpm (the ratio (weight ratio) of each content was epoxy resin: Ethylene _{glycol: CaH 2 = 31: 4:} 65).
Note that 480 g was used for the mixture 1 (for forming the bottom portion and the lower standing portion), and 160 g (for a total of 640 g) was used for the mixture 2 (for forming the upper standing portion).

Comparative Example 1
In Example 1, the same conditions as in Example 1 were used, except that the granulated product 640 g was used as a columnar hydrogen generator having a thickness of 110 mm and a diameter of 113 mm without forming a cylindrical standing portion. A hydrogen generator was produced.

Reference Experiment Example 1
In Example 1, 60 g of the granulated product was used to form the bottom part of the hydrogen generating agent, and then a spacer (stainless steel wire, 60φ height 40 mm) was installed, and a cylinder was formed on the spacer using 50 g of the granulated product. A hydrogen generator was manufactured under the same conditions as in Example 1 except that a standing upright portion was formed.

Reference experiment example 2
In Reference Experimental Example 1, the same as Reference Experimental Example 1, except that the granulated product 60g was used to form a cylindrical hydrogen generator having a thickness of 30 mm and a diameter of 72 mm without forming a cylindrical standing portion. A hydrogen generator was manufactured under the conditions.

  Evaluation items in Examples and the like were measured as follows.

(1) Reactivity 10 ml / hr (Example 1, Reference Experimental Examples 1 and 2, Comparative Example 1) or 5 ml / hr (Examples 2 to 3) from the supply unit to each of the hydrogen generators obtained as described above. ) Was supplied at a constant rate, and the flow rate of hydrogen generation (mL / min) was measured with a membrane flow meter (flow meter: SF-2U, volume tube: VP-2U). The results are shown in FIGS. Based on this result, the reactivity was evaluated by ○ and ×.

        ○: After the start of the reaction, the hydrogen generation rate (flow rate) can be maintained at a high level until the reaction rate reaches at least about 70%.

        X: The hydrogen generation rate (flow rate) decreases early after the start of the reaction.

(2) Water use efficiency Water use efficiency was calculated from the following formula. The results calculated for each elapsed time are shown in FIGS. 8, 10 and 12, and the total water use efficiency is shown in Table 1.

Water use efficiency (%) = (Amount of water used / Amount of water supplied) × 100
The amount of water used is calculated from the amount of generated hydrogen using the fact that water and generated hydrogen have the same number of moles.

(3) Initial responsiveness The initial responsiveness was evaluated as follows.
○: Within 60 minutes until the hydrogen generation rate (flow rate) is stabilized after the start of the reaction.

        X: After starting the reaction, it takes longer than 60 minutes until the hydrogen generation rate (flow rate) is stabilized.

(4) Responsiveness at stop The responsiveness at stop was evaluated as follows.
○: After stopping the supply of water, it is possible within 60 minutes to reduce the hydrogen generation flow rate to 20% or less.

      X: After stopping the supply of water, it takes longer than 60 minutes to reduce the hydrogen generation flow rate to 20% or less.

  The results are shown in Table 1.

(Results and discussion)
As shown in FIGS. 7 to 8, Example 1 succeeded in greatly improving water use efficiency. This was found to be nearly twice as efficient as Comparative Example 1. Regarding the reactivity, in Example 1, high reactivity could be maintained until the reaction rate reached 80% after the start of the reaction. This is a significant improvement in reactivity compared to the fact that the reactivity is greatly reduced at the stage when the reaction rate after the start of reaction in Comparative Example 1 reaches 20%.
As shown in FIGS. 9 to 10, in Example 3 having a two-layer structure, it was found that the reactivity can be maintained up to 90%. Even in Example 2 having a single layer structure, the reactivity can be maintained up to 65%, but it has been found that the reactivity can be further improved as compared with this. This is considered to be because an unreacted portion hardly remains on the container side (unreacted portion 20 in FIG. 4) on the bottom surface of the standing portion of the hydrogen generating agent, and hydrogen can be generated more efficiently. It is done.
11 to 12 are model experiments using steam. By using a spacer as in Reference Experimental Example 1, it was confirmed how much water vapor affects the hydrogen generation with respect to the cylindrical standing portion. As a result, in the case where there is a cylindrical standing portion, it was confirmed that the reactivity was improved about twice that in the case where there was no cylindrical standing portion. Therefore, it is possible to improve the water vapor utilization efficiency by forming the cylindrical standing portion. As a result, it was found that the water vapor generated by the reaction can be effectively used, and the hydrogen generation reaction can be efficiently performed by this water vapor.

  From the above, as shown in the results of Table 1, in Examples 1 to 3, the hydrogen generation reactivity and responsiveness of the hydrogen generation apparatus were good, and the water utilization efficiency in the hydrogen generation reaction was also good. On the other hand, in Comparative Example 1, not only a good result was not obtained in the hydrogen generation reactivity and responsiveness of the hydrogen generator, but also a good result was not obtained in the water utilization efficiency in the hydrogen generation reaction. .

DESCRIPTION OF SYMBOLS 11 Reaction liquid 12 Supply part 13 Space 14 Hydrogen generating agent 14a Standing part 14b Bottom face part 14c Upper part 14d Lower part 15 Container 16 Hydrogen discharge flow path 17 Reaction site 18 By-product etc. 19 Reaction liquid supplied 20 Unreacted part 21 Space | gap

Claims (15)

A hydrogen generator comprising: a hydrogen generating agent that reacts with a reaction solution to generate hydrogen; and a container that contains the hydrogen generating agent,
The container has a supply unit for supplying the reaction solution to the reaction site,
The hydrogen generator contains a thermosetting resin and granular metal hydride, and has a standing portion that is erected with a space along the wall surface of the container.   The hydrogen generating apparatus according to claim 1, wherein the hydrogen generating agent has a cylindrical upright portion.   The hydrogen generator according to claim 2, wherein the hydrogen generating agent has a bottomed cylindrical shape.   The hydrogen generator according to any one of claims 1 to 3, wherein the hydrogen generator has voids.   The hydrogen generator according to any one of claims 1 to 4, wherein the hydrogen generating agent is formed by binding granular, granular, pellet-like, rod-like, or spherical granules.   The hydrogen generator according to claim 1, wherein the hydrogen generator further contains a hydrophilic polymer.   The hydrogen generator has a two-layer structure of an upper part and a lower part, and the content of the metal hydride contained in the upper part is lower than the content of the metal hydride contained in the lower part. The hydrogen generator of any one of 1-6.   The hydrogen generator according to claim 1, wherein the metal hydride is calcium hydride.   The hydrogen generator according to any one of claims 1 to 8, wherein a content of the metal hydride is 10 to 80% by weight.   The hydrogen generator according to claim 1, wherein the thermosetting resin is an epoxy resin.   The hydrogen generator according to any one of claims 6 to 10, wherein the hydrophilic polymer is polyoxyalkylene glycol.   The hydrogen generator according to any one of claims 6 to 11, wherein the content of the hydrophilic polymer is 2 to 25% by weight. A method for producing a hydrogen generator comprising: a hydrogen generator that reacts with a reaction solution to generate hydrogen; and a container that stores the hydrogen generator,
Preparing the container having a supply part for supplying the reaction solution to the reaction site;
Erecting a mixture containing an uncured thermosetting resin, a hydrophilic polymer, and a granular metal hydride along the wall surface of the container with a space therebetween;
Forming a standing part by heating and curing the mixture. A hydrogen generation method using the hydrogen generator according to any one of claims 1 to 12,
A method for generating hydrogen, comprising: supplying a reaction liquid from the supply unit to a reaction site, and generating hydrogen while raising the reaction site to the supply unit side. The method for generating hydrogen according to claim 14, comprising a step of generating hydrogen using water vapor generated when a reaction solution is supplied from the supply unit to a reaction site.

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