JP2001213609A - Process of producing hydrogen and apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process and an apparatus capable of efficiently producing hydrogen avoiding the gelling of silicic acid ion which is the cause of blocking the generation of hydrogen, and to provide a process and an apparatus capable of continuous supply of hydrogen suitable for practical use. SOLUTION: This process comprises the steps of mixing beforehand powdered silicon with water into slurry state, feeding this silicon powder slurry and alkaline solution to the reactor and catalyticly reacting in the reactor under heating to generate hydrogen.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for producing hydrogen from silicon.

[0002]

2. Description of the Related Art Most of the hydrogen consumed in Japan is
Oil and natural gas obtained by a steam reforming method or a partial oxidation method are consumed in-house in a complex for ammonia synthesis and methanol production. However, because of the low purity of these hydrogens, hydrogen for external sale is produced by industrial use of by-product hydrogen from water electrolysis or salt electrolysis, or by-product hydrogen from petroleum refining processes. That is the current situation.

[0003] However, hydrogen obtained by such a conventional method is generated in a high-temperature and high-pressure environment of several tens to several hundreds of atmospheres and several hundreds of degrees Celsius, requires large energy for production, and is expensive. Therefore, a production method capable of obtaining high-purity hydrogen at low cost is desired.

[0004] On the other hand, it has long been known that hydrogen is generated when silicon is heated in an alkaline solution. However, in the field of manufacturing semiconductor devices, a large amount of silicon that can serve as a hydrogen source is discarded. There are facts. Because of the possibility of supplying abundant raw materials at low cost, such as silicon waste, and the fact that the hydrogen generation reaction between silicon and an alkaline solution can be sufficiently performed in an environment that can be easily set at atmospheric pressure, 100 ° C. or less, The hydrogen production method using silicon is promising.

[0005]

However, the above-mentioned method for producing hydrogen using silicon as a raw material also needs to be suitable for practical use in industrialization in which hydrogen can be supplied efficiently and stably.

For example, in a hydrogen generation reaction by mixing silicon and an alkaline aqueous solution, silicate ions are generated in the solution in addition to the hydrogen gas. The use of silicon or the supply of a large amount of silicon causes a problem that silicate ions become gel-like and inhibit the generation of hydrogen gas.

Further, the reaction between silicon and the alkaline aqueous solution is started violently immediately after the contact between the two, and after a few minutes, most of the amount of hydrogen gas that can be generated is generated, and after that, only a slight reaction continues. It is. That is, since the hydrogen generation rate changes greatly from the start to the end of the reaction, it is difficult to supply hydrogen quantitatively only by taking out the generated hydrogen gas as it is.

Further, as described above, it is conceivable that silicon as a raw material is supplied as powder such as silicon dust, but in such a case, it is difficult to supply powder in a reaction system for heating an alkaline aqueous solution. This may cause clogging in the pipe near the vessel where steam is trapped, or contamination of impurity gas into the reaction system.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a method for producing hydrogen by mixing silicon and an alkaline solution, which avoids gelation of silicate ions which hinder generation of hydrogen gas. It is an object of the present invention to provide a method and an apparatus capable of efficiently producing hydrogen. Another object of the present invention is to provide a hydrogen production method and apparatus suitable for practical use that can continuously supply hydrogen at a constant rate.

[0010]

According to a first aspect of the present invention, there is provided a method for producing hydrogen, comprising supplying powdered silicon and an alkaline solution to a reaction vessel and heating the reaction vessel in the reaction vessel. In a hydrogen production method in which hydrogen is generated by performing a contact reaction below, powdered silicon is previously mixed with water to form a slurry, and this silicon slurry is supplied to a reaction vessel.

According to a second aspect of the present invention, there is provided the hydrogen production method according to the first aspect, wherein the internal pressure of the reaction vessel is determined in advance according to the flow rate of hydrogen extracted from the inside of the reaction vessel. The supply of the silicon slurry and / or the alkaline solution is controlled so as to be kept within the pressure range.

In a third aspect of the present invention, there is provided a hydrogen production method, comprising: a reaction vessel having a pressure-resistant structure; a constant-temperature heating device for heating the reaction vessel to maintain a reaction temperature; A first tank for mixing and storing in a slurry state, a second tank for storing an alkaline liquid, and a liquid supply device for feeding the silicon slurry in the first tank and the alkaline liquid in the second tank into a reaction vessel; A gas deriving device for deriving hydrogen generated in the reaction vessel to the outside.

According to a fourth aspect of the present invention, in the hydrogen production apparatus according to the third aspect, the gas derivation device includes a pressure measurement unit that measures a gas pressure in the reaction vessel. Gas flow control means for controlling the flow rate of hydrogen, and wherein the liquid supply device supplies the liquid from the inside of the reaction vessel based on the pressure value measured by the pressure measurement means and the flow rate value controlled by the gas flow control means. Liquid supply control means is provided for controlling the supply of the silicon slurry and / or the alkaline solution so that the internal pressure of the reaction vessel is maintained within a predetermined pressure range in accordance with the flow rate of hydrogen.

Further, the hydrogen production apparatus according to the invention of claim 5 is the hydrogen production apparatus of claim 4,
The gas flow control means includes a condenser and a mass flow controller for deriving hydrogen at a predetermined flow rate.

According to a sixth aspect of the present invention, in the hydrogen production apparatus according to the fourth aspect, the liquid supply control means includes a pump, and a discharge passage of the pump is connected to the reaction vessel. The first tank and the second tank are connected to each other through an on-off valve that can be connected and that can selectively open and close the suction passage.
The pump is connected in parallel, and starts and stops the pump and opens and closes each on-off valve based on the pressure value measured by the pressure measuring means.

According to a first aspect of the present invention, there is provided a hydrogen production method for producing hydrogen by mixing powdered silicon and an alkaline solution, wherein the raw material powdered silicon is previously mixed with water to form a slurry. Since it is supplied, the amount of liquid in the reaction vessel increases due to the interposition of water to be mixed as compared with the case where silicon is supplied as powder, the silicate ion concentration in the solution is suppressed, and hydrogen gas generation is reduced. The generation of a gel-like by-product that causes inhibition is also suppressed. Also, when silicon is supplied in a slurry state, a violent reaction immediately after the contact between silicon and the alkaline liquid is suppressed, so that a higher concentration of the alkaline liquid can be used, and efficient use of silicon, that is, an increase in the amount of hydrogen gas generated. Can also be planned.

In addition, since the internal pressure of the reaction vessel is increased by the hydrogen gas generated as the hydrogen production reaction proceeds, even if the hydrogen production reaction is continued by simply supplying additional raw materials into the reaction vessel, The hydrogen gas is filled up to the upper pressure limit in the container, and the hydrogen generation reaction cannot be continued further unless the hydrogen gas is led out to lower the container internal pressure. Therefore, if a raw material is additionally supplied as appropriate while deriving the hydrogen gas filling the reaction vessel, the hydrogen generation reaction can be easily continued.

At this time, as described in claim 2, the additional supply of the silicon slurry or the alkaline liquid is controlled so that the internal pressure of the reaction vessel is maintained within a predetermined pressure range in accordance with the flow rate of the hydrogen gas. Then, the hydrogen generation reaction can be efficiently continued, and hydrogen can be obtained continuously and quantitatively.

According to a third aspect of the present invention, in the hydrogen production apparatus, powder silicon is mixed with water in a first tank and stored in a slurry state, and an alkaline liquid is stored in a second tank. The silicon slurry in the first tank and the alkaline solution in the second tank are fed into a pressure-resistant reaction vessel, and the reaction vessel is heated by a constant-temperature heating device to carry out a hydrogen generation reaction while maintaining the reaction temperature. The hydrogen generated in the above is led out of the reaction vessel by a gas lead-out device and collected.

According to the apparatus having the above-described configuration, the supply of the raw material silicon into the reaction vessel by the liquid supply device is performed in a slurry state from the first tank, so that clogging of the piping and mixing of impurity gas are prevented. In addition, the supply of silicon together with the alkaline solution from the second tank can be smoothly and easily controlled, and the generation of a gel-like by-product accompanying the progress of the reaction can be suppressed, so that the generation of hydrogen gas proceeds well. is there. Therefore, according to the present apparatus, continuation of the additional supply of the mechanical raw material and continuous reaction are possible, and efficient and continuous hydrogen production can be realized.

Further, as described in claim 4, the gas deriving device is provided with a pressure measuring means for measuring a gas pressure in the reaction vessel and a gas flow rate controlling means for controlling a hydrogen deriving flow rate,
Based on the pressure value measured by the pressure measuring device by the liquid supply control means of the liquid supply device and the flow rate value controlled by the gas flow rate control means, the internal pressure of the reaction vessel is determined in advance according to the flow rate of hydrogen derived from the inside of the reaction vessel. If the additional supply of the silicon slurry and / or the alkali solution is controlled so as to be kept within the specified pressure range, the hydrogen generation reaction can be automatically continued, and the hydrogen can be continuously and quantitatively produced. .

As a gas flow rate control means for controlling the flow rate of hydrogen out of the reaction vessel, one provided with a condenser and a mass flow controller is simple. With this configuration, hydrogen can be led out of the reaction vessel at a predetermined flow rate.

Further, as a specific configuration of the liquid supply apparatus in the hydrogen production apparatus of the present invention, since the raw material silicon is in a slurry state, a method using a pump is simple and easy in controlling the supply of the raw material. For example, when the silicon slurry and the alkali solution are fed into the reaction vessel from the first tank and the second tank via the pump, the discharge flow path of the pump is connected to the reaction vessel, and the suction flow path can be selectively opened and closed, respectively. The liquid supply control is performed by connecting the first tank and the second tank in parallel via a simple open / close valve and starting and stopping the pump based on the pressure value measured by the pressure measuring means, and opening / closing each open / close valve. As a means, it is possible to easily control the additional supply of the raw material for continuing the hydrogen generation reaction so that the quantitative derivation and recovery of hydrogen can be continuously performed.

[0024]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a schematic configuration diagram of a hydrogen production apparatus as one embodiment of the present invention. This apparatus heats the reaction vessel 1 based on the measurement result of the reaction vessel 1 having a real volume of 12 L having a pressure resistance structure and a thermocouple 8 for checking the solution temperature in the reaction vessel 1. A constant temperature water circulation device 2 as a constant heating device for maintaining; a first tank 3 for mixing powdered silicon and water and storing the slurry in a slurry state; and a second tank for storing an alkaline liquid as a liquid supply device 4 and the first tank 3 and the second tank 4 are connected in parallel with each other via on-off valves (11, 12) which can be opened and closed, respectively, and the discharge passage is connected to the reaction vessel 1. And a pump 5.

Further, as a gas deriving device for deriving hydrogen gas generated in the reaction vessel to the outside, a condenser 6 and a mass flow controller 7 for deriving hydrogen gas at a predetermined flow rate are provided.

The present apparatus is provided with a pressure sensor (pressure measuring means) 9 for measuring the gas pressure in the reaction vessel 1. The pressure value measured by the pressure sensor 9 and the flow rate value of the hydrogen gas are measured. Of the pump 5 on the liquid supply device side and the on-off valves (11, 12)
A control device (not shown) for controlling the opening and closing of the camera is provided.

The control device controls the first tank 3 and the second tank 3 so that the internal pressure of the reaction vessel is maintained within a predetermined pressure range in accordance with the derivation of hydrogen from the inside of the reaction vessel 1 during operation of the apparatus.
The supply and addition of the silicon slurry and the alkaline solution from the tank 4 are controlled, and the hydrogen generation reaction is continued so that quantitative desorption and recovery of hydrogen can be continuously performed.

When the additional supply of the raw material is repeated to some extent and the solution in the reaction vessel 1 reaches a predetermined amount, the drain valve 13 is opened and the solution is discharged from the reaction vessel 1 to the drain tank 10. After the drain valve 13 is closed, the raw material supply is started again to continue the hydrogen generation reaction.

[0029]

EXAMPLE As a first example of the present invention, a case where a hydrogen production reaction was carried out using the hydrogen production apparatus shown in FIG. 1 and continuous hydrogen production was carried out by continuing the reaction by additional supply of raw materials. This will be described below. As an initial state, first, 1 L of 0.5 N sodium hydroxide aqueous solution is accommodated in the reaction vessel 1, heated by the constant temperature heating device 2 to maintain the liquid temperature at 80 ° C., and powdered silicon is placed in the first tank 3. While being stirred and mixed with water, it is stored in a 10 wt% silicon slurry state,
A 1N aqueous sodium hydroxide solution is stored in the second tank 4.

At the same time when the pump 5 is started by the control device, the respective on-off valves (11, 12) are sequentially opened, and 0.1 L of 10 wt% silicon slurry is supplied from the first tank 3 and 1N aqueous sodium hydroxide solution is supplied from the second tank 4. 0.1 L is introduced into each reaction vessel 1 to start a hydrogen generation reaction.
The addition of the 1N aqueous sodium hydroxide solution is for resisting the dilution of the aqueous alkaline solution with the water content of the slurry.

After the start of the reaction, the measurement of the amount of generated hydrogen gas and the additional supply of 0.1 L of a 10 wt% silicon slurry and 0.1 L of a 1N aqueous sodium hydroxide solution were repeated every 10 minutes to continue the hydrogen generation reaction. In the present embodiment, nine additional material supply operations were repeated after the supply of the raw material at the plant. On the way, when the amount of the solution in the reaction vessel 1 reaches a certain amount,
After the drain valve 13 is opened and the solution is discharged to the drain tank 10 to reduce the solution to 1 L, the additional supply of the raw material is restarted.

Hydrogen gas generation amount (L) measured every 10 minutes
Is shown in a bar graph, and the consumption rate (%) with respect to the charged silicon is shown in FIG. 2 in a line graph. As a result, by first additionally supplying silicon in a slurry state, the same degree of hydrogen generation reaction can be continued for each raw material supply without generating a gel-like by-product that hinders hydrogen gas generation,
It was confirmed that continuous hydrogen production at predetermined intervals was possible. Further, the silicon consumption rate in each reaction at each interval was about 80%, and the hydrogen generation reaction was performed with very high efficiency.

Next, as a second embodiment, when the continuous reaction carried out in the first embodiment is continued for a long time, the raw materials (0.1 L of a 10 wt% silicon slurry and a 0.1 N aqueous sodium hydroxide solution of 0.1 L) were added. It was examined whether a change occurs in the hydrogen generation process from the time of additional supply of 1 L). That is, immediately after the start of the reaction, and 10 hours from the time of the additional supply of the raw materials at the time when the continuous reaction is continued for a long time from the start of the reaction, here, 8 hours.
The integrated value of the amount of hydrogen generated per minute was determined over time in each case.

The results are shown in the polygonal line diagram of FIG. 3 (horizontal axis: elapsed time (minutes) from supply of raw material, vertical axis: integrated value of generated hydrogen amount (converted to L.degree. C.)). As can be seen from FIG. 3, hydrogen generation from the time of additional supply of raw materials immediately after the start of the reaction is as follows.
Most of the hydrogen generated in a few minutes after the supply is generated, and the generation of hydrogen from the time of the additional supply of the raw material 8 hours after the start of the reaction, the hydrogen is generated only after a lapse of 6, 7 minutes after the supply. The formation reaction proceeded slowly.

Therefore, the generation of hydrogen from the time of additional supply of the raw material is not uniform depending on the continuation state of the reaction, and the continuation time is prolonged as the amount and components of the reaction solution change over a long time. Was found to be slow.

Therefore, in the continuation of the hydrogen generation reaction over a long period of time, the timing of the additional supply of the raw material for continuously deriving the quantitative amount of hydrogen from the reaction vessel is determined by changing the hydrogen generation state as the reaction continuation is repeated. We examined how to control in response to changes in

Theoretically, when the inside of the reaction vessel is filled with hydrogen gas generated in the initial reaction, hydrogen is quantitatively led out of the vessel, and while the hydrogen gas in the reaction vessel is decreasing, the amount of hydrogen is reduced. If additional hydrogen is supplied to obtain a state where the hydrogen is filled again in the reaction vessel before all the hydrogen has been completely desorbed, quantitative dehydrogenation over a long period of time can be performed without interruption of hydrogen depletion. I can do it.

Therefore, by controlling the additional supply of the raw material based on the change in the internal pressure due to the decrease in the hydrogen gas in the reaction vessel, it is possible to continuously maintain the quantitative derivation of hydrogen. That is, the supply of the raw material may be controlled so that the hydrogen gas is generated such that the inside of the reaction vessel is kept within a predetermined pressure range in accordance with the flow rate of hydrogen.

Therefore, first, based on the upper limit value and the lower limit value determined in advance as the above-mentioned pressure range, the internal pressure of the reaction vessel which decreases with the derivation of hydrogen for the maximum and minimum hydrogen desorption rates for the reaction vessel 1 in FIG. Simulation was performed under certain conditions to determine at what point in time the additional material should be supplied.

As the simulation conditions, the upper limit of the range pressure is set to 0.245 MPa from the pressure resistance of the apparatus, and the lower limit is set to 0.049 MPa, which is the lower limit pressure at which stable control by the mass flow controller 7 is possible. Maximum hydrogen derivation rate 1 L / m from the filled state
Changes in the pressure in the reaction vessel when hydrogen was discharged at in and at the minimum hydrogen discharge rate of 0.1 L / min were measured.
The results are shown in the graphs of FIGS. 4A and 4B, respectively, and the pressure inside the reaction vessel decreases almost linearly with the derivation of hydrogen.

In response to such a change in the internal pressure of the reaction vessel at the maximum and minimum derivation speeds, the internal pressure of the reaction vessel satisfies the upper and lower limits of the pressure range in all steps of the reaction continuation for a long time (here, about 8 hours). In order to perform the hydrogen generation as described above, the upper and lower limits when the hydrogen generation state shown in FIG. 3 is combined with the change in the internal pressure of each container may be maintained within the pressure range.

When such a state is simulated, the results are shown in the graphs of FIGS. 5A and 5B at the maximum and minimum derivation speeds, respectively. From this result, at the maximum hydrogen desorption rate of 1 L / min, the internal pressure of the reaction vessel was 0.108 MPa.
When the internal pressure of the reaction vessel reaches 0.059 MPa at the minimum hydrogen desorption rate of 0.1 L / min at the time point when the pressure reaches 0.059 MPa, the supply of hydrogen from the reaction vessel can be continued without interruption. A constant amount of hydrogen can be maintained over the continuous state.

From the above results, if the pressure value in the reaction vessel at which the raw material is to be supplied in accordance with the hydrogen desorption rate is determined in advance, it is only necessary to measure the pressure value in the reaction vessel during the long-term continuation of the hydrogen generation reaction. In addition, it is possible to control so as to supply the additional material at an appropriate timing, and it is possible to easily maintain continuous quantitative derivation of hydrogen.

Next, as a third embodiment of the present invention, quantitative production of hydrogen was performed by using the apparatus shown in FIG. 1 and continuing the reaction by controlling the additional supply of the raw materials under the condition setting based on the above simulation results. In this embodiment, the deriving speed of hydrogen is 1 L
/ min, and the pressure in the reaction vessel at the timing of performing the additional supply of the raw material was set to 0.108 MPa.

The basic operation of the apparatus is the same as that of the first embodiment. First, as an initial state, 1 L of a 0.5 N sodium hydroxide aqueous solution is accommodated in the reaction vessel 1, heated by the constant temperature heating device 2 to maintain the liquid temperature at 80 ° C., and the inside of the reaction vessel 1 is purged with nitrogen gas. .

At the same time when the pump 5 is started by the control device, the on-off valves (11, 12) are sequentially opened, and 0.1 L of 10 wt% silicon slurry is supplied from the first tank 3 and 1N aqueous sodium hydroxide solution is supplied from the second tank 4. 0.1 L is introduced into the reaction vessel 1. When a predetermined amount of the raw material is introduced, the on-off valves (11, 12) are closed, and the pump 5 is stopped. The hydrogen generation reaction starts simultaneously with the introduction of these raw materials into the reaction vessel 1, and at the same time, the measurement of the pressure in the reaction vessel 1 by the pressure sensor 9 also starts.

When the measured pressure value reaches the upper limit of 0.196 MPa based on the withstand pressure value of the apparatus, the hydrogen gas is led out of the reaction vessel by the mass flow controller 7 at a rate of 1 L / min and collected. The value measured by the pressure sensor 9 is 0.10
When the pressure reaches 8 MPa, the pump 5 and each on-off valve (11, 1
2) The drive is controlled to additionally supply raw materials (0.1 L of 10 wt% silicon slurry and 0.1 L of 1N sodium hydroxide aqueous solution) from the first tank 3 and the second tank 4 respectively. The above-described additional supply of the raw material based on the value measured by the pressure sensor 9 is repeated.

When the amount of the solution in the reaction vessel 1 reaches a predetermined amount, the supply of hydrogen is stopped and the drain valve 13 is opened to discharge the solution to the drain tank 10.
Reduce to Thereafter, the raw material is supplied again, and when the internal pressure of the container reaches 0.196 MPa, the supply of the raw material based on the value measured by the pressure sensor 9 is repeated, starting with the derivation of hydrogen at the predetermined speed.

FIG. 6 is a line chart showing the change of the additional material supply timing, the pressure in the container (MPa) and the amount of hydrogen gas taken out (L / min) with time in the above hydrogen production process. As described above, quantitative continuous production of hydrogen could be performed only by controlling the additional supply of the raw material based on the pressure value in the reaction vessel.

The silicon slurry used as a raw material in the present invention is obtained by mixing powdered silicon with water. The source of silicon is not limited. For example, silicon waste generated from a semiconductor manufacturing line may be used. May be used. In this case, since the waste is used, the cost of producing hydrogen is greatly reduced. In addition, as for the alkaline liquid, an alkaline waste liquid can be used.

[0051]

As described above, according to the hydrogen production method of the present invention, since the raw material silicon is supplied in a slurry state mixed with water, the generation of a gel-like by-product which may hinder the generation of hydrogen gas is generated. As well as suppressing the violent reaction immediately after the contact between silicon and the alkali solution, the alkali solution can be used at a higher concentration, which enables not only efficient use of silicon but also supply of silicon raw materials. This also facilitates the continuous generation of hydrogen gas by continuing the hydrogen generation reaction by additionally supplying the raw material.

Further, according to the hydrogen production apparatus of the present invention, there is an effect that the supply of the raw material and the recovery of the produced hydrogen can be easily controlled, and the mechanical production of hydrogen can be easily performed. further,
The additional supply of the raw material can be easily controlled based on the pressure value in the reaction vessel, and the constant production of hydrogen can be continuously performed while maintaining the continuation of the reaction.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a hydrogen production apparatus as one embodiment of the present invention.

FIG. 2 is a bar graph (horizontal axis: elapsed time (minutes), vertical axis) showing a time change of a hydrogen production amount and a silicon consumption rate in a hydrogen production process using the apparatus of FIG. 1 as a first embodiment of the present invention; : Hydrogen gas generation amount (L) every 10 minutes) and a line chart (horizontal axis: elapsed time (minutes), vertical axis: consumption rate (%) with respect to silicon input).

FIG. 3 shows a second embodiment of the present invention, in which 1
It is a polygonal line diagram (horizontal axis: elapsed time (minutes), vertical axis: hydrogen integrated value (L) converted at 0 ° C.) showing the integrated value of the amount of hydrogen generated in 0 minutes. : Black diamond) and the raw material supply (原料; black square) 8 hours after the start of the reaction.

FIG. 4 is a graph (horizontal axis: time (minutes), vertical axis: pressure (MPa)) in the hydrogen production apparatus of FIG. Yes,
(A) shows the case where the maximum hydrogen derivation rate is 1 L / min, and (b) shows the case where the minimum hydrogen desorption rate is 0.1 L / min.

FIG. 5 is a diagram showing the reaction when the additional raw material is supplied immediately after the start of the reaction (◆: black diamond) and 8 hours after the start of the reaction (■; black square) based on the results of FIGS. 4 and 3 FIG. 6 is a diagram (horizontal axis: time (minutes), vertical axis: container pressure (MPa)) showing a simulation result of the time change of the pressure in the container;
(A) shows the case where the maximum hydrogen derivation rate is 1 L / min, and (b) shows the case where the minimum hydrogen desorption rate is 0.1 L / min.

FIG. 6 shows a third embodiment of the present invention in which the hydrogen supply apparatus of FIG. 1 is used to control the additional supply of the raw material based on the pressure value in the reaction vessel to perform continuous quantitative production of hydrogen. Line graph showing changes in the pressure in the container and the amount of hydrogen gas taken out with time along with the raw material supply timing (horizontal axis: hydrogen outgoing time (minutes), vertical axis: container pressure (MPa) and hydrogen gas outgoing amount (L) ).

[Explanation of symbols]

 1: Reaction vessel 2: Constant temperature heating device 3: First tank 4: Second tank 5: Pump 6: Condenser 7: Mass flow controller 8: Temperature sensor 9: Pressure sensor 10: Drain tank 11, 12: Open / close valve 13: Drain valve

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yoshiaki Takazawa 2410 Motoe, Uozu City, Toyama Prefecture Inside Suginoma Shin Co., Ltd.

Claims (6)

[Claims] In a hydrogen production method for producing hydrogen by supplying powdered silicon and an alkaline solution to a reaction vessel and causing them to react under heating in the reaction vessel, powdered silicon is mixed with water in advance. And supplying the silicon slurry to a reaction vessel. 2. The supply of a silicon slurry and / or an alkali solution is controlled such that the internal pressure of the reaction vessel is maintained within a predetermined pressure range in accordance with the flow rate of hydrogen extracted from the inside of the reaction vessel. The method for producing hydrogen according to claim 1. 3. A reaction vessel having a pressure-resistant structure, a constant temperature heating device for heating the reaction vessel to maintain a reaction temperature, and a first method for mixing powdered silicon with water and storing it in a slurry state.
A tank, a second tank for storing an alkaline liquid, a liquid supply device for feeding the silicon slurry in the first tank and the alkaline liquid in the second tank into a reaction vessel, and a hydrogen generated in the reaction vessel. A hydrogen production device comprising: a gas derivation device for deriving the gas to the outside. 4. The gas discharge device includes a pressure measurement unit that measures a gas pressure in the reaction vessel and a gas flow control unit that controls a discharge flow rate of hydrogen. Silicon based on the measured pressure value and the flow rate value controlled by the gas flow rate control means so that the internal pressure of the reaction vessel is maintained within a predetermined pressure range in accordance with the flow rate of hydrogen derived from the inside of the reaction vessel. Slurry and / or
4. The hydrogen production apparatus according to claim 3, further comprising a liquid supply control unit for controlling supply of the alkaline liquid. 5. The hydrogen production apparatus according to claim 4, wherein said gas flow rate control means includes a condenser and a mass flow controller for deriving hydrogen at a predetermined flow rate. 6. The liquid supply control means includes a pump,
The discharge flow path of the pump is connected to the reaction vessel, and the suction flow path is connected in parallel to the first tank and the second tank via open / close valves that can be selectively opened / closed, respectively, and measured by the pressure measuring means. The hydrogen production apparatus according to claim 4, wherein the pump is started and stopped and each of the on-off valves is opened and closed based on the pressure value.