JP6989879B1 - Hydrogen generator, hydrogen generation system, raw material cartridge, and hydrogen generation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydrogen generating apparatus capable of stably producing hydrogen with simple operation in a hydrogen generating apparatus for generating hydrogen by hydrolysis of ammonia borane. SOLUTION: Hydrogen generated by hydrolysis of a reaction vessel 31 provided in a reaction vessel 31 which is detachably provided in a raw material cartridge 3 filled with an ammonia borane aqueous solution 51a and holds a catalyst 41 and a reaction vessel 31. Based on the hydrogen discharge pipe 9 from which the hydrogen is discharged, the pressure detection unit 11 that detects the pressure in the reaction vessel 31, and the pressure detected by the pressure detection unit 11, the internal pressure of the reaction vessel 31 is a predetermined target. The flow rate of the aqueous ammonia borane solution 51a flowing from the raw material cartridge 3 into the reaction vessel 31 is adjusted so that the pressure is maintained, the internal pressure of the reaction vessel 31 drops below the target pressure, and the opening degree of the flow rate adjusting valve 15 is 100. A hydrogen generation device 1 provided with a flow rate adjusting means 13 for closing the flow rate adjusting valve 15 by determining that the raw material cartridge is empty when the target pressure cannot be maintained even by%. [Selection diagram] Fig. 1

Description

The present invention relates to a hydrogen generation device, a hydrogen generation system, a raw material cartridge, and a hydrogen generation method.

Since hydrogen does not generate carbon dioxide when burned, it has a smaller environmental load than fossil fuels, but it has a lower melting point than fossil fuels, so a dedicated high-pressure tank is required when storing it as a liquid or gas. Since the high-pressure tank is made of metal, there is also the problem that hydrogen diffuses and becomes embrittlement.

There are storage means such as hydrogen storage alloys that store hydrogen using the diffusion of hydrogen, but hydrogen storage alloys are a rare metal with a high density among alloys, so they are heavy and costly.

There is also a method of storing hydrogen in an organic hydride such as methylcyclohexane, but the organic hydride requires heating to generate hydrogen, and there is a problem that the purity of the generated hydrogen is lowered because the vapor pressure of the material is high.

Therefore, ammonia borane (NH ₃ BH ₃ ) has been studied as a means for storing hydrogen (Patent Document 1). Ammonia borane is a hydride that produces hydrogen by thermal decomposition, and has a higher molecular weight than organic hydride, so it has a high hydrogen storage capacity. Since it has a melting point of about 104 ° C and is non-flammable, it is also advantageous in that it is easy to store and transport. On the other hand, there is a problem that a heat source is required for thermal decomposition, the reaction is multi-step and the control tends to be complicated, and the size of the apparatus becomes large.

Therefore, a method has been proposed in which an aqueous solution of ammonia borane is brought into contact with a catalyst such as Pt at room temperature to generate hydrogen by hydrolysis (Non-Patent Document 1).

In addition, a device has been proposed in which a flexible reservoir containing ammonia borane water is urged by a spring or the like to introduce ammonia borane water into a reaction chamber in which the catalyst is housed and bring it into contact with the catalyst to generate hydrogen. (Patent Document 2). This device adjusts the valve opening of the microvalve provided between the reservoir and the reaction chamber according to the stack voltage of the fuel cell to which hydrogen is supplied, and the ammonia borane supplied from the reservoir to the reaction chamber. The amount of water is adjusted.

U.S. Patent Application Publication No. 2007/0253894 Japanese Unexamined Patent Publication No. 2004-87470

Manish Chandra, Qiang Xu, “A high-performance hydrogen generation system: Transition metal-catalyzed dissociation hydrolysis of ammonia-borane”, Journal of Power Sources 156 (2006), p190-194

The method of obtaining hydrogen by hydrolyzing ammonia borane as in Patent Document 2 is easy to miniaturize and carry because hydrogen can be generated without pressurization at room temperature if there is water, ammonia borane and a catalyst. , Expected as an outdoor power source for leisure and disasters.

On the other hand, since the users of outdoor power sources are assumed to be general consumers who do not have knowledge of ammonia borane, the operation of hydrogen generation is simple and the function of stably producing hydrogen is required. However, in the technique of Patent Document 2, the standard for determining the supply amount of ammonia borane water is the stack voltage of the fuel cell to which hydrogen is supplied, and the progress of the reaction in the reaction vessel is not taken into consideration. Therefore, if the amount of hydrogen produced in the reaction vessel is too large or too small, the supply amount cannot be adjusted, and there is a possibility that hydrogen cannot be stably produced.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a hydrogen generator capable of producing hydrogen stably by simple operation in a hydrogen generator that generates hydrogen by hydrolysis of ammonia borane. ..

In order to solve the above problems, one aspect of the present invention is a hydrogen generating apparatus for producing hydrogen by contacting an aqueous ammonia borane solution with a catalyst that promotes a reaction for producing hydrogen by hydrolysis of ammonia borane. A reaction vessel that is detachably provided on a raw material cartridge that is a container filled with an aqueous ammonia borane and holds the catalyst, and a reaction vessel that is provided in the reaction vessel and supplied from the raw material cartridge to the reaction vessel. It is a connection part between a hydrogen discharge pipe from which hydrogen generated by hydrolysis of an ammonia borane aqueous solution is discharged, a pressure detection unit for detecting the pressure in the reaction vessel, and the raw material cartridge in the reaction vessel. A flow control valve is provided in the raw material supply pipe that supplies the ammonia borane aqueous solution into the reaction vessel, and the flow rate can be adjusted by adjusting the valve opening, based on the pressure detected by the pressure detection unit. The flow rate of the ammonia borane aqueous solution flowing from the raw material cartridge into the reaction vessel is adjusted so that the internal pressure of the reaction vessel is maintained at a predetermined target pressure, and the reaction is carried out after the supply of the ammonia borane aqueous solution. If the internal pressure of the container drops below the target pressure and the opening of the flow control valve is 100% but the target pressure cannot be maintained, it is determined that the raw material cartridge is empty and the flow rate is adjusted. It is characterized by comprising a flow rate adjusting means for closing the valve.

In this configuration, when an aqueous ammonia borane solution is supplied to the reaction vessel, hydrogen is generated while the internal pressure of the reaction vessel is maintained at the target pressure. If the internal pressure of the reaction vessel drops below the target pressure and the opening of the flow rate control valve is 100% but the target pressure cannot be maintained, it is judged that the raw material cartridge is empty and the flow rate control valve is closed. Close.

Therefore, since the internal pressure at the time of reaction can be automatically controlled only by supplying ammonia borane water to the reaction vessel, the operation is simple and stable hydrogen can be generated.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a hydrogen generating apparatus capable of stably producing hydrogen with simple operation in a hydrogen generating apparatus that generates hydrogen by hydrolysis of ammonia borane.

It is a schematic diagram which shows the hydrogen generation system provided with the hydrogen generation apparatus which concerns on this embodiment, and the raw material cartridge, a reaction container, and a waste liquid storage container are shown in a vertical sectional view. It is a figure which shows the modification of the raw material cartridge of FIG. A modification of the hydrogen generation device of FIG. 1, (a) shows an example in which a catalyst is arranged in a conical shape, and (b) shows an example in which a shower is attached to a raw material supply pipe. It is a figure which shows the procedure of hydrogen generation using the hydrogen generation system of FIG. 1, and shows the process of connecting a raw material cartridge to a reaction vessel, and generating hydrogen. It is a flow chart which shows the operation of the flow rate control part in the state of FIG. It is a figure which shows the procedure of the hydrogen generation method using the hydrogen generation system provided with the hydrogen generation apparatus which concerns on this embodiment, and shows the process of removing a raw material cartridge from a reaction vessel. It is a figure which shows the procedure of the hydrogen generation method using the hydrogen generation system provided with the hydrogen generation apparatus which concerns on this embodiment, and shows the process of connecting a waste liquid storage container to a reaction vessel. It is a figure which shows the procedure of the hydrogen generation method using the hydrogen generation system provided with the hydrogen generation apparatus which concerns on this embodiment, and shows the process of discharging a waste liquid into a waste liquid storage container.

Hereinafter, embodiments suitable for the present invention will be described in detail with reference to the drawings.

First, a schematic configuration of a hydrogen generation system 100 including a hydrogen generation device 1 according to the present embodiment will be described with reference to FIGS. 1 to 3.

In FIG. 1, as a hydrogen generation device 1, a device in which an aqueous ammonia borane solution 51a is brought into contact with a catalyst 41 that promotes a reaction to generate hydrogen by hydrolysis of ammonia borane to generate hydrogen and supply it to a fuel cell is exemplified. ..

As shown in FIG. 1, the hydrogen generation system 100 includes a raw material cartridge 3, a hydrogen generation device 1, and a waste liquid storage container 5.

The raw material cartridge 3 is a container for storing the ammonia borane aqueous solution 51a, which is a raw material for hydrogen. Ammonia borane aqueous solution 51a is a solution in which ammonia borane is dissolved in water. As shown in FIG. 1, the raw material cartridge 3 includes a raw material storage container 51, a raw material side connecting pipe 53, a raw material side valve 55, and a raw material side fixed flange 53a.

The raw material storage container 51 is a hollow container, and the inside is filled with an aqueous ammonia borane solution 51a and, if necessary, an atmospheric gas 51b.

The pressure of the atmospheric gas 51b is preferably higher than the internal pressure of the hydrogen generator 1. This is because the aqueous ammonia borane solution 51a can be supplied to the hydrogen generator 1 at the pressure of the atmospheric gas 51b. The atmospheric gas 51b can be appropriately selected as long as it is a gas that does not decompose during the reaction in which the aqueous ammonia borane solution 51a produces hydrogen by hydrolysis, does not react with other materials, and does not interfere with the operation of the fuel cell. In terms of cost, air from which nitrogen (N ₂ ) gas or carbon dioxide has been removed is preferable, but argon may also be used.

The higher the ammonia borane concentration of the ammonia borane aqueous solution 51a, the higher the amount of hydrogen produced per unit volume. It adheres to 41 and hinders hydrogen production. Therefore, the ammonia borane concentration is preferably such that the boric acid concentration in the waste liquid does not exceed the solubility, and specifically, about 1 mol / liter is preferable.

The dimensions of the raw material storage container 51 are set according to the volume of the aqueous ammonia borane solution 51a to be stored. The shape of the raw material storage container 51 is preferably such that the stress due to the internal pressure of the atmospheric gas 51b and the weight of the aqueous ammonia borane solution 51a is not concentrated in a specific place. FIG. 1 illustrates a vertically long cylindrical container having both ends spherical.

The raw material side connecting pipe 53 is a pipe for injecting / discharging the ammonia borane aqueous solution 51a and the atmospheric gas 51b between the inside and the outside of the raw material storage container 51, and is hollow connected to the lower end of the raw material storage container 51 in FIG. It penetrates to the inside of the part.

The raw material side valve 55 is a valve body that opens / closes the raw material side connecting pipe 53, and is provided in the middle of the raw material side connecting pipe 53.

The raw material side fixing flange 53a is a member for fixing the raw material side connecting pipe 53 in a state of being connected to the hydrogen generating device 1, and is provided around the outer periphery of the lower end of the raw material side connecting pipe 53 in FIG. It is a disk-shaped member having a hole for insertion. The fixing means may be a clamp or the like instead of a bolt.

As the material constituting the raw material cartridge 3, a material having a strength that does not corrode with the aqueous ammonia borane solution 51a and does not deform during use may be selected. For example, stainless steel is used.

The raw material storage container 51 of the raw material cartridge 3 shown in FIG. 1 is arranged above the hydrogen generating device 1, and supplies the ammonia borane aqueous solution 51a to the hydrogen generating device 1 by gravity and the pressure of the atmospheric gas 51b.

However, the raw material cartridge 3 may be provided with a mechanism for assisting the supply by pressurizing the ammonia borane aqueous solution 51a from the outside when supplying the ammonia borane aqueous solution 51a to the hydrogen generating apparatus 1.

Examples of such a configuration include the configurations shown in FIGS. 2 (a) to 2 (c).

The raw material cartridge 3a shown in FIG. 2A has the same structure as the raw material cartridge 3, but a fluid injection pipe 71, which is a separate pipe from the raw material side connecting pipe 53, is provided in the raw material storage container 51 of the raw material cartridge 3. The point is different.

The fluid injection pipe 71 is a pipe for injecting a fluid to be applied when the ammonia borane aqueous solution 51a is pressurized and supplied to the hydrogen generation device 1 from the outside, and includes an injection flange 75 and an injection valve 73.

The injection flange 75 is a member for fixing the fluid supply source and the fluid injection pipe 71 in a connected state. In FIG. 2A, the injection flange 75 is provided around the outer periphery of the upper end of the fluid injection pipe 71, and a fixing bolt or the like is provided. It is a disk-shaped member having a hole for insertion.

FIG. 2A illustrates a syringe 77 as a fluid source. The syringe 77 is provided with a syringe-side flange 79 that can be fixed to the tip of the fluid injection port in a state of being connected to the injection flange 75. The structure of the syringe-side flange 79 is a disk-shaped member having a hole through which a fixing bolt or the like is inserted, similar to the injection flange 75. In this structure, the syringe-side flange 79 is connected to and fixed to the injection flange 75, and fluid is injected from the syringe 77 using an electric syringe pump or the like. Like the atmospheric gas 51b, the fluid to be injected is a gas or liquid that does not decompose during the reaction in which the aqueous ammonia borane 51a hydrolyzes to generate hydrogen, does not react with other materials, and does not interfere with the operation of the fuel cell. Yes, for example, it is the same gas as the atmosphere gas 51b.

The injection valve 73 is a valve body that opens / closes the fluid injection pipe 71, and is provided in the middle of the fluid injection pipe 71.

It is preferable that the injection valve 73 is a check valve because the atmospheric gas 51b and the ammonia borane aqueous solution 51a in the raw material storage container 51 do not flow back into the syringe 77. However, when the syringe 77 is provided with a check valve, the injection valve 73 does not have to be a check valve.

By providing the raw material cartridge 3a with the fluid injection pipe 71 in this way, the ammonia borane aqueous solution 51a can be pressurized with the fluid from the outside through the fluid injection pipe 71.

Therefore, the ammonia borane aqueous solution 51a can be supplied to the hydrogen generation device 1 regardless of the positional relationship between the raw material cartridge 3a and the hydrogen generation device 1 and their postures.

Further, in this configuration, the pressure at the time of pressurizing the ammonia borane aqueous solution 51a can be adjusted by the amount and pressure of the fluid injected from the syringe 77 into the raw material cartridge 3a. Therefore, the pressure can be finely adjusted as compared with the known configuration in which the ammonia borane aqueous solution 51a is pressurized by an urging member such as a spring.

The raw material cartridge 3c shown in FIG. 2B is provided with the fluid injection pipe 71 like the raw material cartridge 3a, except that the bag body 81 is provided.

The bag 81 is provided in the raw material cartridge 3c and is connected to the fluid injection pipe 71. Here, it is provided in the raw material storage container 51. The bag 81 is made of a material such as rubber that expands with the fluid injected from the fluid injection pipe 71, and pressurizes the ammonia borane aqueous solution 51a by expanding. In this configuration, the ammonia borane aqueous solution 51a is not directly pressurized by the fluid injected from the outside, but is pressurized through the bag 81.

Both the raw material cartridge 3a and the raw material cartridge 3c have the common effect that the pressure can be finely adjusted as compared with the known configuration in which the ammonia borane aqueous solution 51a is pressurized by an urging member such as a spring. Therefore, which structure should be adopted may be appropriately determined in consideration of the advantages of each.

For example, since the raw material cartridge 3a does not require a bag 81, it is advantageous in terms of cost of the raw material cartridge 3a.

On the other hand, since the raw material cartridge 3c does not come into contact with the pressurizing fluid and the ammonia borane aqueous solution 51a, a fluid that reacts with the ammonia borane aqueous solution 51a can be used, which is advantageous in that the range of fluid selection is wide.

In the raw material cartridge 3b shown in FIG. 2C, the raw material storage container 51 has a cylindrical outer shape, and the peripheral surface 83 of the cylinder has a bellows-like shape that can be expanded and contracted in the axial direction of the cylinder.

In this structure, when the upper end of the raw material cartridge 3b is pressed downward by, for example, an electric actuator, the crease of the bellows is bent and the raw material storage container 51 contracts in the axial direction of the cylinder to reduce the volume. As the volume becomes smaller, the filling pressure of the atmospheric gas 51b filled in the raw material storage container 51 becomes higher, so that the ammonia borane aqueous solution 51a is pressurized.

The mechanism for pressurizing the aqueous ammonia borane solution 51a is not a mechanism for injecting a fluid from the outside to pressurize it, but a mechanism for increasing the filling pressure of the filled fluid by contracting the raw material cartridge 3b to reduce the volume. But it may be.

This configuration is advantageous in that a fluid supply source is not required because the fluid is not injected from the outside when the ammonia borane aqueous solution 51a is pressurized. It is also advantageous that a known urging member such as a spring is not required.

Further, in this configuration, if there is no inflow of gas from the outside, the bellows-shaped portion contracts due to the weight of the raw material storage container 51 and the ammonia borane aqueous solution 51a, and the ammonia borane aqueous solution 51a is supplied to the hydrogen generation device 1. Will be done. In this case, it is also advantageous that the pressurization itself becomes unnecessary.

The hydrogen generation device 1 is a device that brings the ammonia borane aqueous solution 51a supplied from the raw material cartridge 3 into contact with the catalyst 41 to generate hydrogen and supply it to the fuel cell.

As shown in FIG. 1, the hydrogen generation device 1 includes a reaction vessel 31, a raw material supply pipe 33, a generation side fixed flange 33a, a hydrogen discharge pipe 9, a pressure detection unit 11, a flow rate adjusting means 13, a hydrogen valve 9a, and a catalyst holding unit 38. , A watering means 35, and a float 61.

The hydrogen generation device 1 also includes a waste liquid discharge pipe 46, a waste liquid valve 48, a waste liquid container fixing flange 46a, a vent pipe 45, and a relief valve 47.

The reaction vessel 31 is a hollow vessel that holds the catalyst 41 and causes the supplied ammonia borane aqueous solution 51a to come into contact with the catalyst 41 to generate hydrogen. The reaction vessel 31 in FIG. 1 exemplifies a vertically elongated cylindrical vessel having both ends spherical.

A cylindrical neck portion 29 having a diameter smaller than that of the reaction vessel 31 is provided at the upper end of the reaction vessel 31. The neck portion 29 is a portion to which the hydrogen discharge pipe 9 and the vent pipe 45 are attached.

The raw material supply pipe 33 is a connection portion with the raw material cartridge 3 in the reaction vessel 31, and is a pipe for supplying the ammonia borane aqueous solution 51a from the raw material cartridge 3 into the reaction vessel 31 via the raw material side connection pipe 53. The raw material supply pipe 33 is fixed to the upper end surface of the neck portion 29 in FIG. The lower end of the raw material supply pipe 33 is arranged inside the reaction vessel 31, and the upper end protrudes upward from the neck portion 29. As a result, the aqueous ammonia borane solution 51a can be supplied into the reaction vessel 31 by gravity from the raw material cartridge 3.

The generation-side fixing flange 33a is a member for fixing the raw material-side connecting pipe 53 in a state of being connected to the raw material supply pipe 33, and is provided around the outer periphery of the upper end of the raw material supply pipe 33 in FIG. The generation-side fixing flange 33a has the same structure as the raw material-side fixing flange 53a, and can be fixed to each other by inserting bolts into the holes of each other and fastening them with nuts.

The pressure detection unit 11 is a pressure sensor that detects the pressure inside the reaction vessel 31, and if the pressure inside the reaction vessel 31 can be detected with a desired accuracy and does not corrode in the atmosphere inside the reaction vessel 31, the structure and material are appropriate. You can choose. In FIG. 1, a pressure detection unit 11 is provided in the middle of the hydrogen discharge pipe 9. This is to prevent the pressure detection unit 11 from coming into contact with the ammonia borane aqueous solution 51a that has flowed into the reaction vessel 31. However, if the contact with the aqueous ammonia borane solution 51a can be prevented, or if the pressure can be detected with a desired accuracy even if the contact is made, the pressure detecting unit 11 may be provided in the reaction vessel 31.

The flow rate adjusting means 13 is a means for controlling the rate of hydrogen generation by adjusting the flow rate of the ammonia borane aqueous solution 51a flowing into the reaction vessel 31. When hydrogen is generated, the pressure inside the reaction vessel 31 fluctuates due to the partial pressure of the generated hydrogen. Therefore, by providing the flow rate adjusting means 13, it is possible to prevent a state in which hydrogen is not generated due to an underspeed or a state in which the internal pressure of the reaction vessel 31 may be excessively increased due to an overspeed and the reaction vessel 31 may be damaged.

The flow rate adjusting means 13 is an aqueous ammonia borane solution that flows into the reaction vessel 31 from the raw material cartridge 3 so that the internal pressure of the reaction vessel 31 is maintained at a predetermined target pressure based on the pressure detected by the pressure detection unit 11. Adjust the flow rate of 51a.

On the other hand, the flow rate adjusting means 13 sets the flow rate of the ammonia borane aqueous solution 51a flowing from the raw material cartridge 3 into the reaction vessel 31 to 0 when the internal pressure is equal to or lower than the target pressure even at the maximum flow rate and the target pressure cannot be maintained.

The case where the internal pressure is equal to or lower than the target pressure even when the flow rate is maximum is the case where the entire amount of the aqueous ammonia borane solution 51a flowing into the reaction vessel 31 is hydrolyzed to exhaust the hydrogen. In this case, the raw material cartridge 3 is empty and it is necessary to remove the raw material cartridge 3 from the reaction vessel 31, so the flow rate is set to 0.

As described above, in the hydrogen generation system 100, when the aqueous ammonia borane solution 51a is supplied to the reaction vessel 31, hydrogen is generated in a state where the internal pressure of the reaction vessel 31 is maintained at the target pressure.

Therefore, since the internal pressure at the time of reaction is automatically controlled only by the operation of supplying the aqueous ammonia borane solution 51a to the reaction vessel 31, the operation at the time of hydrogen generation is simple and stable hydrogen can be generated.

Further, the hydrogen generation system 100 stops the supply of the aqueous ammonia borane solution 51a when the internal pressure of the reaction vessel 31 drops and cannot maintain the target pressure. Therefore, the control of the end of hydrogen generation can be automated, and the operation at the time of hydrogen generation can be automated. Is simple and can stably generate hydrogen.

The lower limit of the target pressure is the pressure at which the hydrogen production rate can supply the minimum amount of hydrogen required for the operation of the fuel cell to which hydrogen is supplied. The upper limit of the target pressure is the upper limit of the internal pressure that does not damage the reaction vessel 31 or the fuel cell.

The flow rate adjusting means 13 shown in FIG. 1 includes a flow rate adjusting valve 15, a flow rate control unit 17, and a solution valve actuator 19.

The flow rate adjusting valve 15 is a valve body whose valve opening degree can be adjusted, and is provided in the middle of the raw material supply pipe 33.

The flow rate control unit 17 is a control unit that adjusts the flow rate of the ammonia borane aqueous solution 51a passing through the flow rate adjusting valve 15 according to the internal pressure of the reaction vessel 31, and is connected to the pressure detection unit 11 to input the internal pressure. Specifically, the flow rate control unit 17 sets the flow rate of the ammonia borane aqueous solution 51a supplied from the raw material cartridge 3 to the reaction vessel 31 so that the internal pressure of the reaction vessel 31 is maintained at a predetermined target pressure. In addition, the valve opening degree of the flow rate adjusting valve 15 is adjusted.

The solution valve actuator 19 is an actuator that adjusts the valve opening degree of the flow rate control valve 15, is connected to the flow rate control unit 17 and the flow rate control valve 15, and drives the flow rate control valve 15 based on the command of the flow rate control unit 17 to drive the valve. Actually set the opening.

In this configuration, the flow rate control unit 17 controls the solution valve actuator 19 so that the internal pressure of the reaction vessel 31 is maintained at a predetermined target pressure, and adjusts the valve opening degree.

Therefore, during the hydrogen generation reaction, the internal pressure of the reaction vessel 31 is maintained at the target pressure and the pressure during the reaction does not change, so that the reaction can proceed stably and rapidly.

The operation method of the flow rate adjusting means 13 in FIG. 1 exemplifies an electronic method using an electronic circuit.

For example, the flow rate control unit 17 is a control unit equipped with an electronic PIC (Pressure Indicating Control), and the pressure detection unit 11 is a system that outputs the internal pressure of the reaction vessel 31 as an electric signal. The solution valve actuator 19 is also electronic.

In this configuration, the internal pressure of the reaction vessel 31 detected by the pressure detection unit 11 is input to the flow rate control unit 17 as an electric signal, and the flow control unit 17 maintains the internal pressure of the reaction vessel 31 at the target pressure based on the input value. A control signal indicating the degree is transmitted to the solution valve actuator 19.

However, the operation method of the flow rate adjusting means 13 may be an pneumatic method using an air circuit.

For example, the pressure detection unit 11 is configured to output an air pressure signal indicating the detected internal pressure of the reaction vessel 31, and the flow rate adjusting means 13 is used as a control signal to the solution valve actuator 19 based on the air pressure signal input from the pressure detection unit 11. It is configured to output a pneumatic signal. The solution valve actuator 19 is also an air-driven actuator.

Whether the flow rate adjusting means 13 is an electronic type or an pneumatic type is appropriately set in consideration of the use of the hydrogen generating device 1 and the advantages of each.

For example, the electronic type has a faster response speed than the pneumatic type because the information transmission medium is an electron, and it is easy to miniaturize. Therefore, when the installation space of the hydrogen generation device 1 is narrow or the hydrogen generation device 1 is portable. It is advantageous in some cases.

On the other hand, the pneumatic type does not require a power source for operation and can supply hydrogen even when a power source cannot be secured in the event of a disaster, which is advantageous when the hydrogen generation device 1 is used in the event of a disaster.

When the flow rate control unit 17 is a control unit that adjusts the valve opening degree of the flow rate adjusting valve 15 according to the internal pressure of the reaction vessel 31, the internal pressure of the reaction vessel 31 rises / falls by how much the valve opening degree should be. You need to know what to do. Therefore, it is preferable that the flow rate control unit 17 stores in advance a valve opening degree-pressure mapping 17a showing the relationship between the valve opening degree of the flow rate adjusting valve 15 and the pressure in the reaction vessel 31. The flow rate control unit 17 can adjust the flow rate by referring to the valve opening degree-pressure mapping 17a and adjusting the valve opening degree so that the reaction vessel 31 is maintained at the target pressure. As the mapping, the one obtained in the previous experiment conducted using the ammonia borane aqueous solution 51a having the same concentration may be used.

By adjusting the flow rate based on the valve opening-pressure mapping 17a in this way, the flow rate is adjusted under the condition that the target pressure is surely maintained, so that hunting and overshoot can be prevented. When the flow rate is directly measured, a mapping showing the relationship between the flow rate and the pressure in the reaction vessel 31 may be obtained in advance and the mapping may be referred to.

As a specific control method for maintaining the internal pressure of the reaction vessel 31 at the target pressure, a known method may be used. The flow rate adjusting means 13 of FIG. 1 is a device that performs feedback control for adjusting the valve opening degree based on the internal pressure of the reaction vessel 31, but cascade control may also be performed.

When performing cascade control, the detection target of the primary regulator may be one of the valve opening degree or the flow rate, and the detection target of the secondary regulator may be the other of the valve opening degree or the flow rate. If the flow rate adjusting valve 15 cannot detect the flow rate, a flow meter is provided in the raw material supply pipe 33.

In principle, temperature control inside the reaction vessel 31 is unnecessary. This is because the hydrogen generation device 1 is a device that hydrolyzes the aqueous ammonia borane solution 51a at room temperature to obtain hydrogen, and it is not necessary to control the reaction to be promoted by an operation such as raising the temperature.

However, if the place where the hydrogen generator 1 is installed in midsummer or midwinter is significantly higher or lower than room temperature, a structure for keeping the reaction vessel 31 warm may be provided. In this case, the structure for keeping the heat is controlled. , The temperature of the reaction vessel 31 may be maintained at about room temperature. Alternatively, since the hydrolysis reaction of the aqueous ammonia borane solution 51a is an exothermic reaction, the aqueous ammonia borane solution 51a may boil if the reaction amount increases and too much heat is generated. Therefore, a cooling mechanism may be provided to keep the aqueous ammonia borane solution 51a at least below the boiling point.

In the reaction vessel 31, the flow rate adjusting means 13 adjusts the flow rate of the ammonia borane aqueous solution 51a in order to suppress the fluctuation of the internal pressure due to hydrogen generation, so that the internal pressure rises as the flow rate increases, and as a result, the reaction vessel 31 is pressurized. However, a pressurizing means other than the flow rate adjusting means 13 is unnecessary. This is because the hydrogen production reaction by hydrolysis of the aqueous ammonia borane solution 51a proceeds even at normal pressure.

Since hydrogen generation is started when the worker opens the valve 55 on the raw material side, the start condition is basically set manually. However, the start condition may be automated by configuring the raw material side valve 55 so that the flow rate adjusting means 13 can automatically open and close.

The target for the termination condition of hydrogen generation, that is, the condition for determining that the raw material cartridge 3 is emptied due to the hydrolysis of all the ammonia borane aqueous solution 51a and the exhaustion of hydrogen, is the internal pressure of the reaction vessel 31 after the supply of the ammonia borane aqueous solution 51a. This is a case where the pressure drops below the pressure and the target pressure cannot be maintained even though the opening degree of the flow control valve 15 is 100% (fully open). As described above, unlike the known hydrogen generation system, the present embodiment is characterized in that the internal pressure of the reaction vessel 31 is used not only for controlling the reaction but also for determining whether or not the raw material cartridge 3 is empty. Is. The following examples are given as more specific conditions for the termination condition of hydrogen production.

First, the internal pressure of the reaction vessel 31 is equal to or less than the target pressure in a state where the flow rate of the aqueous ammonia borane solution 51a flowing from the raw material cartridge 3 into the reaction vessel 31 is maximized, that is, in a state where the valve opening of the flow rate adjusting valve 15 is fully opened. The case can be the end condition (condition A).

When the opening degree of the flow rate adjusting valve 15 is fully opened, the flow rate of the aqueous ammonia borane solution 51a supplied to the reaction vessel 31 becomes maximum and the hydrogen generation reaction proceeds, so that the pressure should increase. Therefore, if the pressure is equal to or lower than the target pressure in this state, it can be determined that the raw material cartridge 3 is emptied and hydrogen is also generated.

Therefore, it may be determined that the internal pressure of the reaction vessel 31 cannot be maintained at the target pressure in this state, and the flow rate may be reduced to 0 by closing the flow rate adjusting valve 15 to end hydrogen generation.

In this configuration, since the flow rate adjusting valve 15 is closed when the aqueous ammonia borane solution 51a in the raw material cartridge 3 is emptied, the raw material cartridge 3 can be quickly removed after the reaction is completed, and waste liquid can be treated or a new raw material cartridge can be treated. 3 can be installed quickly.

Next, even if the internal pressure of the reaction vessel 31 is equal to or less than the target pressure even after a predetermined time has elapsed with the flow rate of the aqueous ammonia borane solution 51a flowing into the reaction vessel 31 maximized, the termination condition can be set (condition B).

Condition B is different from Condition A in that it is determined that hydrogen production has been completed when a predetermined time has elapsed from the state in which it is determined that hydrogen production has been completed under Condition A.

The reason for waiting for the elapse of a predetermined time under condition B is due to the rate of hydrogen generation and the unreacted ammonia borane aqueous solution 51a even after the flow rate of the ammonia borane aqueous solution 51a is maximum and the internal pressure of the reaction vessel 31 becomes equal to or less than the target pressure. This is because the production of hydrogen may continue.

Even when the maximum flow rate becomes equal to or lower than the target pressure, it is possible to prevent the unreacted ammonia borane aqueous solution 51a from being discarded as a waste liquid by waiting until a predetermined time elapses.

The predetermined time referred to here is a time at which hydrogen is predicted to be generated after the maximum flow rate becomes equal to or lower than the target pressure, and may be actually measured by an experiment.

Further, when the target pressure is set lower than the filling pressure of the atmospheric gas 51b in the raw material cartridge 3, the end condition may be set based on the filling pressure of the atmospheric gas 51b of the raw material cartridge 3 (condition C). .. Specifically, the flow rate control unit 17 applies the internal pressure when the internal pressure of the reaction vessel 31 is lower than the filling pressure by a predetermined value, that is, when the internal pressure of the reaction vessel 31 is close to the filling pressure. It may be determined that the target pressure cannot be maintained. In this case, the flow rate of the flow rate adjusting valve 15 is set to 0, and hydrogen generation is terminated.

This is because when the aqueous ammonia borane solution 51a in the raw material cartridge 3 is emptied and hydrogen generation is completed, the atmospheric gas 51b flows into the reaction vessel 31 from the raw material cartridge 3 and the internal pressure approaches the filling pressure.

The predetermined predetermined value is the difference pressure between the filling pressure of the atmospheric gas 51b and the internal pressure of the reaction vessel 31 when the aqueous ammonia borane solution 51a in the raw material cartridge 3 is empty and hydrogen is completely released. It can be obtained by experiment.

In this way, the end condition may be set based on the filling pressure of the atmospheric gas 51b of the raw material cartridge 3. In this configuration, it is not always necessary to refer to the valve opening degree and the flow rate of the flow rate adjusting valve 15, so that the control is simpler than the condition A and the condition B.

The termination condition may be determined by the worker (condition D).

Specifically, the solution valve actuator 19 may be provided with a switching mechanism 21 for switching the adjustment of the flow rate by the solution valve actuator 19 from one of manual and automatic to the other.

In this case, when the hydrogen generation starts, the flow rate adjustment by the solution valve actuator 19 is automatically switched by the switching mechanism 21, and when the worker determines that the hydrogen generation reaction is completed, the flow rate adjustment is switched to manual and manually. The flow rate adjusting valve 15 may be closed at.

By providing the switching mechanism 21 and determining the end condition by the worker, the raw material cartridge 3 can be removed when the worker visually recognizes that the raw material cartridge 3 is empty, so that workability is improved.

The hydrogen discharge pipe 9 is a pipe that supplies the hydrogen generated by the hydrogen generation device 1 to the fuel cell. One end of the hydrogen discharge pipe 9 penetrates the cylindrical surface of the neck portion 29 and is exposed inside the reaction vessel 31, and the other end is connected to a fuel cell (not shown). It is preferable that the hydrogen discharge pipe 9 is provided with a porous material called an ammonia filter for collecting ammonia or an ammonia absorbing material of a metal salt such as NiCl ₂ or copper sulfate inside. This is because when hydrogen is generated by the hydrolysis of the aqueous ammonia borane solution 51a, ammonia may be produced as a by-product, and the ammonia may interfere with the operation of the fuel cell.

The hydrogen valve 9a is a valve body that opens / closes the hydrogen discharge pipe 9, and is provided in the middle of the hydrogen discharge pipe 9.

FIG. 1 illustrates a structure in which a valve opening degree can be automatically set as a hydrogen valve 9a. Specifically, a hydrogen valve actuator 9b that electrically adjusts the opening degree of the hydrogen valve 9a is connected. The hydrogen valve actuator 9b is electrically connected to the flow rate control unit 17. In this configuration, the flow control unit 17 drives the hydrogen valve actuator 9b so as to supply hydrogen at a pressure within the operating range of a fuel cell or the like connected to the hydrogen discharge pipe 9 based on the pressure detected by the pressure detection unit 11. Then, the valve opening degree of the hydrogen valve 9a is adjusted. Specifically, when the pressure detected by the pressure detection unit 11 is higher than the pressure within the operating range of the fuel cell or the like, the hydrogen valve 9a is opened at a valve opening that can supply hydrogen with a pressure within the operating range. If the pressure is other than the above, the hydrogen valve 9a is closed.

However, as long as the hydrogen valve 9a can supply hydrogen at the pressure required by the device connected to the hydrogen discharge pipe 9, the operation method does not have to be a method of electrically controlling the hydrogen valve actuator 9b. For example, a self-supporting pressure reducing valve may be used to supply hydrogen at a pressure within the operating range of a fuel cell or the like. Alternatively, the pressure detection unit 11 is provided with a meter that allows the worker to visually recognize the detected pressure, and the worker manually operates the hydrogen valve 9a so as to refer to the meter and supply hydrogen at a pressure within the operating range of the fuel cell or the like. It may be a method.

The catalyst holding portion 38 is a pair of porous plate-shaped members that vertically sandwich and hold the catalyst 41, and is provided further below the lower end of the raw material supply pipe 33, which is the outlet of the raw material supply pipe 33. Here, the member on the upper side with respect to the catalyst 41 is referred to as a dispersion plate 37, and the member on the lower side is referred to as a holding plate 39.

The reason why the catalyst holding portion 38 is porous is that the ammonia borane aqueous solution 51a and the waste liquid after the reaction for generating hydrogen from the ammonia borane aqueous solution 51a are passed therethrough.

The catalyst holding portion 38 has a strength capable of holding the catalyst 41, and the structure can be appropriately set as long as the diameter of the porous pores is smaller than the diameter of the catalyst 41. It may be a plate with holes such as punching metal, or it may be a wire mesh.

The material and shape of the catalyst 41 can be appropriately selected as long as it is a material that can promote the hydrolysis reaction of ammonia borane at room temperature, normal pressure, specifically, about 20 ° C. and 101325 Pa.

Specifically, a granular material in which a catalyst metal is supported on activated carbon can be exemplified. As the catalyst metal, platinum (Pt) is preferable in terms of accelerating the production rate of hydrogen, but Ti, Rh, Pd and the like may be used. The catalyst metal may be used alone or as a mixture of a plurality of metals. Alternatively, an alloy containing these metals may be used.

The smaller the particle size of the catalyst 41, the larger the ratio of the surface area to the volume, and the easier it is for the ammonia borane aqueous solution 51a to come into contact with the catalyst 41, so that the rate at which hydrogen is generated increases. On the other hand, if the particle size is smaller than the pores of the catalyst holding portion 38, the catalyst 41 will flow out from the pores, so that it needs to be larger than the pores of the catalyst holding portion 38.

The amount of the catalyst 41 is appropriately set in consideration of the volume of the reaction vessel 31, the load capacity of the holding plate 39, and the target of the amount of hydrogen produced per unit time.

The amount of the catalyst metal supported on the activated carbon may be constant, but the catalyst metal is supported per unit mass of the activated carbon from the holding plate 39 which is the lower catalyst holding portion 38 toward the dispersion plate 37 which is the upper catalyst holding portion 38. It may be laminated so that the mass of the catalyst metal is large.

In this configuration, the amount of catalyst metal is larger in the upper catalyst 41, which is more likely to come into contact with the unreacted ammonia borane aqueous solution 51a. Is provided. As a result, the hydrogen generation rate is made uniform as a whole, boiling of the solution due to excessive heat of reaction can be prevented, and unreacted ammonia borane can be prevented from flowing into the waste liquid storage container 5. ..

As a method of improving the rate of hydrogen generation, there is also a method of changing the laminated structure of the catalyst 41 without changing the amount of the catalyst metal supported on the activated carbon.

For example, as shown in FIG. 3A, the dispersion plate 37 may be a porous plate having a conical or pyramidal shape. The peripheral surface of the dispersion plate 37 is connected to the holding plate 39, and the tip of the cone faces the outlet of the raw material supply pipe 33. In this structure, since the space sandwiched between the dispersion plate 37 and the holding plate 39 becomes a cone, the laminated structure of the catalyst 41 held in the space also becomes a cone.

In this case, the surface area of the uppermost surface of the laminated body of the catalyst 41 is larger than that in the case where the dispersion plate 37 is a disk-shaped member as shown in FIG. Therefore, the area of the catalyst 41 in contact with the aqueous ammonia borane solution 51a supplied into the reaction vessel 31 can be increased in a short time, and the rate of hydrogen generation can be increased.

The watering means 35 is a means for evenly sprinkling the ammonia borane aqueous solution 51a supplied from the raw material supply pipe 33 onto the catalyst 41 in a range wider than the cross-sectional area of the outlet of the raw material supply pipe 33.

Since the raw material supply pipe 33 is a pipe, if there is no watering means 35, the ammonia borane aqueous solution 51a supplied into the reaction vessel 31 comes into contact with the catalyst 41 only in the range of the cross-sectional area of the outlet of the raw material supply pipe 33. In this case, since the catalyst 41 that does not come into contact with the aqueous ammonia borane solution 51a does not contribute to the hydrolysis reaction, it is preferable to provide the watering means 35.

FIG. 1 illustrates a storage dish 35a as a watering means 35.

The storage dish 35a is provided below the outlet of the raw material supply pipe 33 and above the dispersion plate 37, and is a circular dish-shaped member that temporarily stores the ammonia borane aqueous solution 51a supplied from the raw material supply pipe 33. The edge of the reservoir 35a is a horizontal circle.

In this structure, the ammonia borane aqueous solution 51a supplied from the raw material supply pipe 33 into the reaction vessel 31 first accumulates in the storage dish 35a. When the water level of the accumulated ammonia borane aqueous solution 51a exceeds the depth of the storage dish 35a, the ammonia borane aqueous solution 51a overflowing from the edge of the storage dish 35a is radially and evenly flowed down to the dispersion plate 37 and flows into the catalyst 41.

By having the structure in which the ammonia borane aqueous solution 51a overflowing from the circular storage dish 35a flows into the catalyst 41 in this way, the ammonia borane aqueous solution 51a can be evenly contacted over a wide range of the catalyst 41 with a simple structure.

As long as the aqueous ammonia borane solution 51a can be sprinkled over a wider area than the cross-sectional area of the outlet of the raw material supply pipe 33, the sprinkling means 35 does not have to be the storage pan 35a.

For example, the shower 35b shown in FIG. 3B may be used as the watering means 35.

The shower 35b is a hollow conical component whose open upper end is connected to the outlet of the raw material supply pipe 33. The lower end surface is a plate having an area larger than the cross-sectional area of the outlet of the raw material supply pipe 33, and has a plurality of pores.

In this configuration, the ammonia borane aqueous solution 51a supplied into the reaction vessel 31 from the outlet of the raw material supply pipe 33 is uniformly and widely sprayed from the pores of the shower 35b toward the catalyst 41. Therefore, the injection range and the injection amount can be easily adjusted by the number and size of the pores.

The float 61 shown in FIG. 1 is a float that can move up and down according to the water level in the reaction vessel 31 of the aqueous ammonia borane solution 51a and the waste liquid after hydrogen generation. It is composed of a material having a lower density than 51a or waste liquid.

If the float 61 does not restrain the horizontal movement, it will move horizontally in the reaction vessel 31 according to the fluctuation of the water level, and the position will be difficult to understand. Therefore, it is preferable to restrain the horizontal movement by fixing it to a slide provided on the inner wall of the reaction vessel 31 that allows only vertical movement.

When the reaction vessel 31 is made of an opaque material, the float 61 can be visually recognized from the outside of the reaction vessel 31 by, for example, forming the reaction vessel 31 in the moving range of the float 61 with a transparent material such as glass.

However, the float 61 does not necessarily have to be visible from the outside if the water level in the reaction vessel 31 can be known to an outside worker. For example, an electric signal may be transmitted or a buzzer may be sounded according to the water level.

In this configuration, the water level of the aqueous ammonia borane solution 51a in the reaction vessel 31 can be seen from the outside of the reaction vessel 31 by looking at the position of the float 61.

The hydrogen generation reaction in one raw material cartridge 3 is completed after the entire amount of the aqueous ammonia borane solution 51a in the raw material cartridge 3 has been supplied into the reaction vessel 31.

Therefore, if the remaining amount of the ammonia borane aqueous solution 51a in the raw material cartridge 3 can be grasped from the position of the float 61, the progress of the hydrogen generation reaction can also be known.

Further, when the worker determines whether or not hydrogen generation has been completed, if the water level indicated by the position of the float 61 becomes the water level corresponding to the case where the ammonia borane aqueous solution 51a in the raw material cartridge 3 becomes empty, hydrogen is generated. It can be determined that the formation reaction has been completed. It may be determined that the hydrogen generation reaction is completed after a predetermined time has elapsed from reaching this water level.

As shown in FIG. 1, the float 61 may be provided in the raw material cartridge 3 instead of in the reaction vessel 31. This is because the water level in the reaction vessel 31 rises as the water level in the raw material cartridge 3 decreases, so that if the water level in the raw material cartridge 3 is known, the water level in the reaction vessel 31 can also be known.

The waste liquid discharge pipe 46 is a pipe that serves as a flow path for discharging the waste liquid after hydrogen generation from the reaction vessel 31, and is provided below the catalyst holding portion 38 in FIG. 1 and connected to the lower end surface of the reaction vessel 31.

The waste liquid valve 48 is a valve body that opens / closes the waste liquid discharge pipe 46, and is provided in the middle of the waste liquid discharge pipe 46.

The waste liquid container fixing flange 46a is a member for fixing the waste liquid discharge pipe 46 in a state of being connected to the waste liquid storage container 5, and is provided around the outer periphery of the lower end of the waste liquid discharge pipe 46 like the raw material side fixing flange 53a for fixing. An example is a disk-shaped member having a hole through which a bolt or the like is inserted.

The vent tube 45 is a tube that discharges the gas in the reaction vessel 31 to the outside when the internal pressure of the reaction vessel 31 becomes too high and the reaction vessel 31 may be damaged. One end of the vent tube 45 penetrates the cylindrical surface of the neck portion 29 and is exposed inside the reaction vessel 31, and the other end is open to the atmosphere.

The relief valve 47 is a valve body that opens / closes the vent pipe 45, but is closed when the differential pressure between the internal pressure and the atmospheric pressure of the reaction vessel 31 is less than a predetermined set pressure, and the differential pressure exceeds the set pressure. It is a valve body that opens automatically.

The set pressure is a differential pressure corresponding to the internal pressure at which the reaction vessel 31 may be damaged.

When the vent pipe 45 and the relief valve 47 are provided, when the differential pressure rises above the set pressure, the relief valve 47 automatically opens and the gas in the reaction vessel 31 is automatically vented until the differential pressure becomes less than the set pressure. It is discharged from 45. Therefore, even if the internal pressure of the reaction vessel 31 cannot be controlled due to a failure of the flow rate adjusting means 13 during hydrogen generation and the pressure rises, the internal pressure can be maintained to such an extent that the reaction vessel 31 is not damaged.

A known material can be selected as long as the material of the hydrogen generating apparatus 1 is not corroded by the aqueous ammonia borane solution 51a and is not deformed by the internal pressure of the generated hydrogen and the weight of the aqueous ammonia borane 51a. For example, stainless steel may be used.

The waste liquid storage container 5 is a hollow container for storing the waste liquid, and the structure and material can be appropriately set as long as it can be connected to the reaction container 31 to store the waste liquid.

However, a structure in which the raw material cartridge 3 is also a waste liquid storage container 5 is preferable. That is, a structure in which the waste liquid discharge pipe 46 is connected to the raw material cartridge 3 and the waste liquid can be stored in the raw material cartridge 3 is preferable. Specifically, the raw material supply pipe 33 and the waste liquid discharge pipe 46 preferably have the same inner and outer diameters at the ends serving as outlets to the outside, and can be connected to the raw material side connection pipe 53. The generation side fixing flange 33a and the waste liquid container fixing flange 46a have the same shape and position of the holes through which the bolts are inserted, and it is preferable that both of them have a structure that can be fixed to the raw material side fixing flange 53a.

In this structure, an empty raw material cartridge 3 that has completely supplied the ammonia borane aqueous solution 51a to the reaction vessel 31 is connected to the waste liquid discharge pipe 46, and the waste liquid is stored in the raw material cartridge 3, so that the empty raw material cartridge 3 is stored in the waste liquid. It is used as a container 5.

Therefore, the manufacturing cost and workability are excellent as compared with the case where the raw material cartridge 3 and the waste liquid storage container 5 are designed separately. Moreover, since the empty raw material cartridge 3 can be used without being discarded, the environmental load is small. Further, when the peripheral surface 83 of the cylinder of the raw material storage container 51 has a bellows shape that can be expanded and contracted as in the raw material cartridge 3b shown in FIG. 2 (c), if the bellows-shaped portion is folded and connected to the raw material cartridge 3. As the waste liquid flows in, the bellows open due to the weight of the waste liquid. Therefore, when the raw material cartridge 3 is used as the waste liquid storage container 5, it is advantageous in that a step of discharging the gas in the raw material storage container 51 to replace the waste liquid is not required.

The above is a description of the schematic configuration of the hydrogen generation system 100 including the hydrogen generation device 1.

Next, an example of the procedure of the hydrogen generation method using the hydrogen generation system 100 will be described with reference to FIGS. 4 to 8.

First, with the hydrogen valve 9a, the flow rate adjusting valve 15, and the waste liquid valve 48 closed, the raw material side fixed flange 53a and the generation side fixed flange 33a of the raw material cartridge 3 filled with the ammonia borane aqueous solution 51a are formed as shown in FIG. Fix it by fastening it with bolts. As a result, the raw material side connecting pipe 53 of the raw material cartridge 3 is fixed in a state of being connected to the raw material supply pipe 33 of the reaction vessel 31.

Next, as shown in FIG. 4, the raw material side valve 55 is opened, the aqueous ammonia borane solution 51a is supplied from the raw material cartridge 3 to the reaction vessel 31 and brought into contact with the catalyst 41 to generate hydrogen by hydrolysis (hydrogen generation step). At this time, the flow rate adjusting means 13 is also activated.

The generated hydrogen opens the hydrogen valve 9a and supplies it to the fuel cell.

During hydrogen generation, the flow rate adjusting means 13 controls the internal pressure of the reaction vessel 31 according to the flow shown in FIG. 5, and if the termination is not performed manually, the termination is determined. Note that FIG. 5 illustrates the cases of condition A and condition B.

Specifically, first, the flow rate control unit 17 of the flow rate adjusting means 13 determines whether or not the internal pressure of the reaction vessel 31 detected by the pressure detection unit 11 is the target pressure, and if it is the target pressure, returns. If the pressure is not the target pressure, the process proceeds to S2 (S1 in FIG. 5).

When it is determined that the internal pressure in S1 is not the target pressure, the flow rate control unit 17 refers to the valve opening-pressure mapping 17a, etc., so that the reaction vessel 31 is maintained at the target pressure. The flow rate is adjusted by adjusting the opening degree (S2 in FIG. 5).

Next, the flow rate control unit 17 determines whether or not the internal pressure of the reaction vessel 31 is equal to or less than the target pressure even when the flow rate is maximum, specifically, whether or not the valve opening degree of the flow rate adjusting valve 15 is maximum and equal to or less than the target pressure. If it is determined that the pressure is below the target pressure, the process proceeds to S4, and if it is determined that the pressure is not below the target pressure, the process returns (S3 in FIG. 5). In the case of condition B, the process proceeds to S4 when the valve opening is maximum and the target pressure or less has elapsed for a predetermined time.

When it is determined in S3 that the valve opening degree of the flow rate adjusting valve 15 is at most the target pressure or less, the flow rate control unit 17 determines that the production of hydrogen has been completed, closes the flow rate adjusting valve 15 and returns (FIG. 5). S4).

When the production of hydrogen is completed, the raw material side valve 55 and the hydrogen valve 9a are closed, and as shown in FIG. 6, the raw material side connecting pipe 53 of the empty raw material cartridge 3 after supplying the ammonia borane aqueous solution 51a is exhausted. Remove from the raw material supply pipe 33. Next, as shown in FIG. 7, the raw material side fixing flange 53a of the removed empty raw material cartridge 3 and the waste liquid container fixing flange 46a are fastened and fixed with bolts or the like. As a result, the raw material side connecting pipe 53 of the empty raw material cartridge 3 is fixed in a state of being connected to the waste liquid discharge pipe 46. In this state, the waste liquid valve 48 and the raw material side valve 55 are opened, and as shown in FIG. 8, the waste liquid remaining in the reaction vessel 31 after hydrogen generation is discharged to the empty raw material cartridge 3 and recovered (waste liquid recovery step). ).

The hydrolysis reaction of ammonia borane can be described by the following reaction formula (1).

NH ₃ BH ₃ + 2H ₂ O → NH ₄ ⁺ + BO _2- + 3H ₂ … ⁽ 1)
Therefore, the waste liquid contains an aqueous solution of ammonium metaborate, but changes from metaboric acid to boric acid over time. This waste liquid may be discarded or may be used if there is a use. Alternatively, the dissolved component such as boric acid may be separated and recovered from the waste liquid.

When all the waste liquid in the reaction vessel 31 is discharged to the raw material cartridge 3, the waste liquid valve 48 and the raw material side valve 55 are closed, and the raw material side connecting pipe 53 of the raw material cartridge 3 is removed from the waste liquid discharge pipe 46 of the reaction vessel 31.

The above is an explanation of an example of the procedure of the hydrogen generation method using the hydrogen generation system 100.

As described above, when the aqueous ammonia borane solution 51a is supplied to the reaction vessel 31, the hydrogen generation apparatus 1 of the present embodiment generates hydrogen in a state where the internal pressure of the reaction vessel 31 is maintained at the target pressure. If the internal pressure of the reaction vessel 31 drops below the target pressure after the supply of the ammonia borane aqueous solution 51a and the opening of the flow rate adjusting valve 15 is 100% but the target pressure cannot be maintained, the raw material cartridge 3 is empty. The flow rate adjusting valve 15 is closed.

Therefore, since the internal pressure at the time of reaction is automatically controlled only by the operation of supplying the aqueous ammonia borane solution 51a to the reaction vessel 31, the operation is simple and stable hydrogen can be generated.

Although the present invention has been described above with reference to the embodiments, the present invention is not limited to the embodiments. It is natural for a person skilled in the art to come up with various modifications and improvements within the scope of the technical idea of the present invention, and these are also included in the present invention.

1: Hydrogen generator 3, 3a, 3b: Raw material cartridge 5: Waste liquid storage container 9: Hydrogen discharge pipe 9a: Hydrogen valve 9b: Hydrogen valve actuator 11: Pressure detection unit 13: Flow rate adjusting means 15: Flow rate adjusting valve 17: Flow rate Control unit 17a: Pressure mapping 19: Solution valve actuator 21: Switching mechanism 29: Neck part 31: Reaction vessel 33: Raw material supply pipe 33a: Generation side fixed flange 35: Water sprinkling means 35a: Storage tray 35b: Shower 37: Dispersion plate 38 : Catalyst holding part 39: Holding plate 41: Catalyst 45: Vent pipe 46: Waste liquid discharge pipe 46a: Waste liquid container fixing flange 47: Relief valve 48: Waste liquid valve 51: Raw material storage container 51a: Ammonia borane aqueous solution 51b: Atmospheric gas 53: Raw material side connection pipe 53a: Raw material side fixed flange 55: Raw material side valve 61: Float 71: Fluid injection pipe 73: Injection valve 75: Injection flange 77: Syringe 79: Syringe side flange 81: Bag body 83: Peripheral surface 100 : Hydrogen generation system

Claims (21)

A hydrogen generator that produces hydrogen by contacting an aqueous solution of ammonia borane with a catalyst that promotes the reaction that produces hydrogen by hydrolysis of ammonia borane.
A reaction container that is detachably provided on a raw material cartridge that is a container filled with the aqueous ammonia borane solution and holds the catalyst, and a reaction container.
A hydrogen discharge pipe provided in the reaction vessel and discharged from hydrogen generated by hydrolysis of the ammonia borane aqueous solution supplied from the raw material cartridge to the reaction vessel.
A pressure detection unit that detects the pressure inside the reaction vessel,
It is a connection portion with the raw material cartridge in the reaction vessel, is provided in a raw material supply pipe for supplying the ammonia borane aqueous solution from the raw material cartridge into the reaction vessel, and the flow rate can be adjusted by adjusting the valve opening degree. The ammonia flowing from the raw material cartridge into the reaction vessel is provided with a flow control valve so that the internal pressure of the reaction vessel is maintained at a predetermined target pressure based on the pressure detected by the pressure detection unit. The flow rate of the borane aqueous solution is adjusted, and after the ammonia borane aqueous solution is supplied, the internal pressure of the reaction vessel drops below the target pressure, and the target pressure is maintained even though the opening degree of the flow rate adjusting valve is 100%. If this is not possible, a flow rate adjusting means that determines that the raw material cartridge is empty and closes the flow rate adjusting valve, and
A hydrogen generator characterized by being equipped with. The flow rate adjusting means is
The valve opening of the flow rate adjusting valve is adjusted so that the internal pressure in the reaction vessel connected to the pressure detection unit and detected by the pressure detection unit is maintained at the target pressure, and the target pressure cannot be maintained. When it is determined, the flow control unit that closes the flow control valve and
The hydrogen generation device according to claim 1, further comprising a valve actuator connected to the flow rate control unit and the flow rate control valve to drive the flow rate control valve based on a command from the flow rate control unit. The flow rate adjusting means is pneumatic.
The pressure detection unit is configured to output an air pressure signal indicating the detected internal pressure of the reaction vessel to the flow rate control unit.
The flow rate control unit uses an air pressure signal as a control signal as a control signal based on the relationship between the valve opening of the flow rate adjusting valve and the internal pressure in the reaction vessel so that the internal pressure in the reaction vessel is maintained at the target pressure. The hydrogen generating apparatus according to claim 2, which is configured to output to the valve actuator. In the flow rate control unit, a valve opening degree-pressure mapping indicating the relationship between the valve opening degree of the flow rate adjusting valve and the pressure in the reaction vessel is stored in advance, and the valve opening degree-pressure mapping is referred to. The hydrogen generating apparatus according to claim 2 or 3, wherein the flow rate is adjusted by adjusting the valve opening degree so that the reaction vessel is maintained at the target pressure. The flow rate control unit
When the internal pressure of the reaction vessel is equal to or lower than the target pressure in a state where the flow rate of the aqueous ammonia borane solution flowing into the reaction vessel is maximized, it is determined that the internal pressure cannot be maintained at the target pressure, and the flow rate is set to 0. The hydrogen generating apparatus according to any one of claims 2 to 4. The flow rate control unit
When the internal pressure of the reaction vessel is equal to or less than the target pressure even after a predetermined time has elapsed with the flow rate of the aqueous ammonia borane solution flowing into the reaction vessel maximized, the internal pressure is set to the target pressure. The hydrogen generating apparatus according to any one of claims 2 to 4, wherein it is determined that the flow rate cannot be maintained and the flow rate is set to 0. The raw material cartridge is filled with atmospheric gas from which carbon dioxide has been removed.
The target pressure is set lower than the filling pressure of the atmospheric gas in the raw material cartridge.
The flow rate control unit
Any of claims 2 to 4 in which it is determined that the target pressure cannot be maintained when the internal pressure of the reaction vessel becomes lower than the filling pressure by a predetermined value, and the flow rate is set to 0. The hydrogen generator according to paragraph 1. The hydrogen generation device according to any one of claims 2 to 7, wherein the flow rate adjusting means includes a switching mechanism for switching the flow rate adjustment from one of manual and automatic to the other. A pair of porous catalyst holding portions provided below the outlet of the raw material supply pipe in the reaction vessel and holding the catalyst vertically.
A pair of waste liquid discharge pipes provided below the catalyst holding portion to discharge the hydrolyzed waste liquid,
The invention according to any one of claims 2 to 8, further comprising a sprinkling means for uniformly sprinkling the ammonia borane aqueous solution supplied from the raw material supply pipe onto the catalyst in a range wider than the cross-sectional area of the outlet of the raw material supply pipe. Hydrogen generator. The watering means is
A storage dish provided below the outlet of the raw material supply pipe and above the catalyst holding portion to temporarily store the aqueous ammonia borane solution supplied from the raw material supply pipe is provided.
The hydrogen generation device according to claim 9, wherein the aqueous ammonia borane solution overflowing from the storage dish is configured to flow into the catalyst through the catalyst holding portion above. The hydrogen generation device according to claim 9, wherein the watering means is a shower provided at the outlet of the raw material supply pipe. The catalyst is a granular material in which a catalyst metal is supported on activated carbon.
Any of claims 9 to 11 which are laminated so that the mass of the supported catalyst metal per unit mass of the activated carbon is increased from the lower catalyst holding portion toward the upper catalyst holding portion. The hydrogen generator according to paragraph 1. The hydrogen generation device according to any one of claims 9 to 11, wherein the dispersion plate which is the catalyst holding portion on the upper side is a conical or pyramidal porous plate whose tip faces the outlet of the raw material supply pipe. In the reaction vessel,
The hydrogen generating apparatus according to any one of claims 9 to 13, wherein a float that can move up and down according to the water level of the aqueous ammonia borane solution and is visible from the outside of the reaction vessel is provided. The raw material supply pipe and the waste liquid discharge pipe have the same outlet shape, and the shape of the outlet is the same.
Any of claims 9 to 14 configured to connect the empty raw material cartridge that has been completely supplied with the ammonia borane aqueous solution to the waste liquid discharge pipe and store the waste liquid after hydrogen generation in the empty raw material cartridge. The hydrogen generator according to paragraph 1. A hydrogen generation system comprising the reaction vessel according to any one of claims 1 to 15 and the raw material cartridge. A raw material cartridge comprising a raw material side connecting pipe connected to the reaction vessel of the hydrogen generating apparatus according to any one of claims 1 to 15, and filled with the ammonia borane aqueous solution and an atmospheric gas. .. A raw material side connection pipe that can be connected to the reaction vessel, which injects / discharges the ammonia borane aqueous solution and the atmospheric gas.
A pipe for injecting a fluid to be supplied to the hydrogen generator by pressurizing the aqueous ammonia borane solution from the outside, and a fluid injection pipe which is a pipe different from the raw material side connection pipe.
17. The raw material cartridge according to claim 17. The raw material cartridge according to claim 18, wherein the raw material cartridge is provided inside and is connected to the fluid injection pipe, and includes a bag body that pressurizes the ammonia borane aqueous solution by expanding with the injected fluid. The raw material cartridge has a cylindrical outer shape and has a cylindrical outer shape.
The raw material cartridge according to claim 19, wherein the peripheral surface of the cylinder has a bellows-like shape that can be expanded and contracted in the axial direction of the cylinder. The hydrogen generation method using the hydrogen generation apparatus according to claim 15.
The raw material cartridge filled with the ammonia borane aqueous solution is connected to the raw material supply pipe of the reaction vessel, the ammonia borane aqueous solution is supplied from the raw material cartridge to the reaction vessel and brought into contact with the catalyst, and hydrogen is hydrolyzed. And the hydrogen generation process to generate
The empty raw material cartridge after the ammonia borane aqueous solution in the raw material cartridge is completely supplied is removed from the raw material supply pipe and connected to the waste liquid discharge pipe, and the waste liquid in the reaction vessel is discharged from the empty raw material cartridge. Waste liquid recovery process to be discharged and collected in
A hydrogen generation method characterized by carrying out.

Images