System for producing hydrogen gas and method for producing hydrogen gas

Abstract

To provide a system for producing hydrogen gas and a method for producing hydrogen gas at low cost and with high purity, by collecting high-purity hydrogen gas at a high collection rate without using large-scale equipment.SOLUTION: A system 100 for producing hydrogen gas includes: a degassing device 20 for degassing raw water; an electrolysis device 30 for generating the hydrogen gas by electrolysis of the raw water deaerated by the degassing device 20; a pipe 62 connecting the degassing device 20 and the electrolysis device 30 and partitioning a flow channel through which the raw water is sent from the degassing device 20 to the electrolysis device 30; and a first oxygen gas supply device 40 for supplying oxygen gas to the degassing device 20 as a gas for deaeration.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a hydrogen gas production system and a hydrogen gas production method for producing hydrogen gas by electrolyzing water. [Background technology]

[0002] Conventionally, various methods have been used to produce hydrogen gas in various industrial fields such as the semiconductor-related field, including partial oxidation, steam reforming, electrolysis, etc. In particular, in the electrolysis method, an electrolysis device that electrolyzes water to generate oxygen gas and hydrogen gas is often used.

[0003] Hydrogen gas obtained by a general electrolysis device contains impurities such as air components (oxygen gas, nitrogen gas, argon gas, carbon dioxide gas) dissolved in the raw water and moisture, and it is necessary to remove the impurities and purify the gas after electrolysis using a purification device. The impurity gas removal purification device often performs adsorption purification, which requires a regeneration process after a certain operating time. Since the generated hydrogen gas is used for this regeneration process, the generated hydrogen gas is lost. In particular, when producing deuterium gas, expensive gas is used for regeneration, which increases the production cost.

[0004] Thus, the following techniques are known as techniques that can obtain high-purity hydrogen gas without purification after electrolysis. Patent Document 1 describes a method for producing hydrogen gas in which raw water to be subjected to electrolysis is flash evaporated under reduced pressure in advance to remove air components from the raw water. Patent Document 2 proposes a method for producing hydrogen gas in which the raw water is degassed by contacting a portion of the hydrogen gas produced by electrolysis with the raw water to remove air components from the raw water. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 3-2237 [Patent Document 2] JP 2006-206989 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, the method of Patent Document 1 requires a large-scale device for flash evaporation under reduced pressure, which increases the production cost, and the method of Patent Document 2 uses a part of the produced hydrogen gas for degassing, but the degassed hydrogen gas contains air components that were contained in the raw water, so it must be discarded, which reduces the recovery rate of the produced hydrogen gas.

[0007] In view of the above problems, the present invention aims to provide a hydrogen gas production system and a hydrogen gas production method that are capable of producing high-purity hydrogen gas at low cost by recovering high-purity hydrogen gas at a high recovery rate without using large-scale equipment. [Means for solving the problem]

[0008] The present inventors have made extensive research to solve the above problems, and have found the following. By degassing the raw water to be electrolyzed using oxygen gas, impurity gases (nitrogen gas, argon gas, carbon dioxide gas, etc.) dissolved in the raw water can be removed, and high-purity hydrogen gas can be produced. Note that the oxygen gas dissolved in the raw water is converted to water during the electrolysis process, and is not contained in the hydrogen gas. By performing degassing using oxygen gas as described above, it is not necessary to install a purification device, and the loss of hydrogen gas used in the regeneration of the purification device can be reduced. Furthermore, the above method does not require a large-scale pretreatment device such as a reduced-pressure flash evaporation device, and the equipment can be made smaller, thereby keeping production costs low. In addition, the present invention does not use the produced hydrogen gas when degassing the raw water, so the recovery rate of hydrogen gas is high, which also contributes to reducing production costs.

[0009] That is, the gist and configuration of the present invention are as follows.

[0010] [1] A degassing device for degassing raw water; an electrolysis device that electrolyzes the raw water degassed by the degassing device to generate hydrogen gas; a pipe connecting the degassing device and the electrolyzer and defining a flow path through which the raw water is sent from the degassing device to the electrolyzer; a first oxygen gas supply device that supplies oxygen gas as a degassing gas to the degassing device; A hydrogen gas production system having the above structure.

[0011] [2] The electrolysis device has an electrolysis cell in which an anode chamber accommodating an anode and a cathode chamber accommodating a cathode are adjacent to each other via an ion exchange membrane, The hydrogen gas production system according to [1] above, further comprising a second oxygen gas supply device that supplies oxygen gas to the anode chamber.

[0012] [3] The raw water contains heavy water, The hydrogen gas production system according to the above [1] or [2], wherein the hydrogen gas generated in the electrolysis device contains deuterium gas.

[0013] [4] A degassing step of degassing the raw water using a degassing device; Thereafter, the raw water is sent from the degassing device to an electrolysis device through a pipe; an electrolysis step of electrolyzing the raw water degassed in the degassing step in the electrolysis device to generate hydrogen gas; having The method for producing hydrogen gas, wherein the raw water is degassed using oxygen gas in the degassing step.

[0014] [5] The electrolysis device has an electrolysis cell in which an anode chamber accommodating an anode and a cathode chamber accommodating a cathode are adjacent to each other via an ion exchange membrane, The method for producing hydrogen gas according to the above-mentioned [4], wherein in the electrolysis step, the anode chamber is purged with oxygen gas.

[0015] [6] The raw water contains heavy water, The method for producing hydrogen gas according to [4] or [5] above, wherein the hydrogen gas generated in the electrolysis step contains deuterium gas. Effect of the Invention

[0016] According to the hydrogen gas production system and hydrogen gas production method of the present invention, high-purity hydrogen gas can be produced at low cost by recovering high-purity hydrogen gas at a high recovery rate without using large-scale equipment. [Brief description of the drawings]

[0017] [Figure 1] 1 is a schematic diagram showing an apparatus configuration of a hydrogen gas production system according to an embodiment of the present invention. [Diagram 2] FIG. 1 is a schematic diagram showing an electrolytic cell in one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] Hereinafter, an embodiment of a hydrogen gas production system and a hydrogen gas production method according to the present invention will be described. Note that the embodiment described below is an example of the present invention, and the configuration of the present invention is not limited to this specific example.

[0019] [Hydrogen gas production system and hydrogen gas production method] FIG. 1 shows the configuration of a hydrogen gas production system 100 according to an embodiment of the present invention. The hydrogen gas production system 100 includes a degassing device 20 that degasifies raw water, an electrolyzer 30 that electrolyzes the raw water degassed by the degassing device 20 to generate hydrogen gas, a pipe 62 that connects the degassing device 20 and the electrolyzer 30 and defines a flow path through which the raw water is sent from the degassing device 20 to the electrolyzer 30, and a first oxygen gas supplying device 40 that supplies oxygen gas to the degassing device 20 as a degassing gas. The electrolyzer 30 also includes an oxygen gas outlet 70 and a hydrogen gas outlet 72 as outlets for the gas generated by electrolysis. The hydrogen gas production system 100 may further include a raw water supply tank 10 that supplies raw water to the degassing device 20, and a second oxygen gas supplying device 50 that supplies oxygen gas to the electrolyzer 30 as a degassing gas.

[0020] 1 , piping 60 connects the raw water supply tank 10 and the degassing device 20 and defines a flow path through which raw water is sent from the raw water supply tank 10 to the degassing device 20. Pipe 64 connects the degassing device 20 and the first oxygen gas supply device 40 and defines a flow path through which oxygen gas is sent from the first oxygen gas supply device 40 to the degassing device 20. Pipe 66 connects the electrolyzer 30 and the second oxygen gas supply device 50 and defines a flow path through which oxygen gas is sent from the second oxygen gas supply device 50 to the electrolyzer 30.

[0021] A hydrogen gas production method according to one embodiment of the present invention can be suitably carried out using a hydrogen gas production system 100, and includes a degassing step in which raw water is degassed in a degassing device 20, a subsequent step of transporting the raw water from the degassing device 20 to an electrolyzer 30 via piping 62, and an electrolysis step in which the raw water degassed in the degassing step is electrolyzed in the electrolyzer 30 to generate hydrogen gas, and is characterized in that in the degassing step, the raw water is degassed using oxygen gas.

[0022] (raw water) The raw water is not particularly limited, and may be water containing at least one of light water (H2O), semi-heavy water (HDO), and heavy water (D2O). For example, normal pure water (water substantially composed of H2O) or deuterium enriched water (water with a higher content of deuterium D than normal pure water, i.e., water with a higher content of at least one of semi-heavy water and heavy water than normal pure water) can be used as the raw water. When deuterium enriched water is used as the raw water, it is preferable that the content ratio of deuterium (D) to all hydrogen atoms in the raw water (deuterium enriched water) is 90 [atom%D] or more, since hydrogen gas in which D is sufficiently concentrated can be obtained. There is no particular limit to the upper limit of the content ratio of D in all hydrogen atoms in the raw water (deuterium enriched water), but from an industrial viewpoint, the content ratio of D to all hydrogen atoms in the raw water (deuterium enriched water) is approximately 99.98 [atom%D] or less. Depending on the electrolysis device used, the raw water may contain a supporting salt such as potassium hydroxide or hypochlorite.

[0023] The content ratio of D to all hydrogen atoms in the raw water can be determined by subjecting the raw water to analysis using a nuclear magnetic resonance spectrometer (e.g., manufactured by JEOL Ltd.), measuring the areas of H atoms and D atoms, and calculating the ratio of the area of ​​D atoms to the total area of ​​H atoms and D atoms.

[0024] (Raw water supply tank) The raw water supply tank 10 is a device that stores raw water, and is connected to the degassing device 20 via piping 60. The material of the raw water supply tank 10 is not particularly limited, but if a material that is easily permeable to air components, such as resin, is used, there is a risk that moisture in the air will permeate and enter the raw water supply tank 10, decreasing the deuterium enrichment level of the raw water, so it is preferable to use a stainless steel or glass material that is not permeable to air components.

[0025] (Plumbing) The hydrogen gas production system 100 has a pipe 60 that connects the raw water supply tank 10 and the degassing device 20 and defines a flow path through which raw water is sent from the raw water supply tank 10 to the degassing device 20. The material of the pipe 60 is not particularly limited, but since a material that is easily permeable to air components, such as resin, may impair the effect of the oxygen gas purging, it is preferable to use a stainless steel or glass material that is not permeable to air components.

[0026] (Degassing device) The degassing device 20 is a device capable of removing air components from the raw water, and is connected to the raw water supply tank 10, the electrolyzer 30, and the first oxygen gas supply device 40 by pipes 60, 62, and 64, respectively. The degassing device 20 is not particularly limited except that it satisfies the above requirements, and a degassing device based on the principle of bubbling degassing, reduced pressure degassing, ultrasonic degassing, or a combination of these can be used. In order to efficiently purge the oxygen gas in the degassing device 20, it is preferable that the degassing device 20 has a sealed structure. In addition to directly degassing the raw water contained in the degassing device 20, it is also preferable to purge the atmospheric gas in the degassing device 20 with oxygen, so that the degassing device 20 is preferably a reduced pressure degassing device (e.g., a rotary evaporator, etc.).

[0027] (First oxygen gas supply device) The first oxygen gas supplying device 40 is connected to the degassing device 20 by piping 64, and supplies oxygen gas to the degassing device 20. The first oxygen gas supplying device 40 may be one that directly supplies oxygen gas to the raw water in the degassing device 20, one that supplies oxygen gas to the space in the degassing device 20 that contacts the raw water (purging the space with oxygen), or one that can do both. The first oxygen gas supplying device 40 is not particularly limited as long as it is a device that can supply oxygen gas, and a conventionally known device can be used.

[0028] In the present invention, the term "oxygen gas" refers to a gas consisting of oxygen. However, it is of course acceptable for the oxygen gas to contain impurity gases that are unavoidable in the industrial field.

[0029] (Plumbing) The hydrogen gas production system 100 has a pipe 64 that connects the degassing device 20 and the first oxygen gas supplying device 40 and defines a flow path through which oxygen gas is sent from the first oxygen gas supplying device 40 to the degassing device 20. The material of the pipe 64 is not particularly limited, but since a material that is easily permeable to air components, such as resin, may impair the effect of oxygen gas purging, it is preferable to use a stainless steel or glass material that is not permeable to air components.

[0030] (Degassing process) The degassing step is a step in which the raw water is degassed using oxygen gas in the degassing device 20. In the degassing step, it is preferable to supply oxygen gas to the degassing device 20 using the first oxygen gas supply device 40. Also, in the degassing step, it is preferable to purge the inside of the degassing device 20 with oxygen gas before supplying raw water to the degassing device 20. Note that the purged or supplied oxygen gas will be dissolved in the raw water, but will not be contained in the produced hydrogen gas as it is converted to water in the subsequent electrolysis step.

[0031] The method of supplying oxygen gas from the first oxygen gas supply device 40 to the degassing device 20 in the degassing step may involve directly supplying oxygen gas to the raw water in the degassing device 20, supplying oxygen gas to the space in contact with the raw water in the degassing device 20 (purging the space with oxygen), or both. The flow rate of the oxygen gas supplied during the degassing step is not particularly limited, but may be about 10 L / min.

[0032] The conditions of the degassing step are preferably adjusted to appropriate conditions taking into account the vapor pressure of water. Specifically, when a reduced pressure degassing device such as a rotary evaporator is used as the degassing device 20, the amount of gas dissolved in water increases in proportion to the partial pressure and decreases in proportion to the temperature. Therefore, from the viewpoint of obtaining an appropriate amount of gas dissolved in water, the pressure in the degassing device 20 in the degassing step is preferably 100 hPa or less. On the other hand, if the pressure in the degassing device 20 in the degassing step is less than 5 hPa, the steam cannot be trapped, leading to a loss of water, so the pressure in the degassing device 20 in the degassing step is preferably 5 hPa or more. In addition, from the viewpoint of obtaining an appropriate amount of gas dissolved in water, the temperature of the internal space of the degassing device 20 in the degassing step is preferably 20°C or more. On the other hand, if the temperature of the internal space of the degassing device 20 in the degassing step exceeds 90°C, excessive energy is required for heating, so the temperature of the internal space of the degassing device 20 in the degassing step is preferably 90°C or less.

[0033] In the degassing process, the raw water is degassed using oxygen gas, thereby removing impurity gases (nitrogen gas, argon gas, carbon dioxide gas, etc.) dissolved in the raw water, and high-purity hydrogen gas can be produced in the subsequent electrolysis process. This eliminates the need to install a purification device, and reduces the loss of hydrogen gas used in regenerating the purification device. Furthermore, the above method does not require large-scale pretreatment equipment such as a reduced-pressure flash evaporation device, making it possible to miniaturize the equipment and keep production costs low. In addition, since the produced hydrogen gas is not used when degassing the raw water, the recovery rate of hydrogen gas is high, which also contributes to reducing production costs.

[0034] (Plumbing) The hydrogen gas production system 100 has a pipe 62 that connects the degassing device 20 and the electrolyzer 30 and defines a flow path through which raw water is sent from the degassing device 20 to the electrolyzer 30. The material of the pipe 62 is not particularly limited, but since a material that is easily permeable to air components, such as resin, may impair the effect of oxygen gas purging, it is preferable to use a stainless steel or glass material that is not permeable to air components.

[0035] (Liquid transfer process) After the degassing step, the raw water is sent from the degassing device 20 to the electrolyzer 30 through the pipe 62. The sending is performed while restoring the pressure inside the degassing device 20, and oxygen gas supplied from the first oxygen gas supply device 40 can be used as the gas for restoring the pressure. In addition, by purging the inside of the electrolyzer 30 with oxygen gas using the second oxygen gas supply device 50 described below before the sending, it is possible to prevent the intrusion of impurities.

[0036] (Electrolysis Apparatus) The electrolyzer 30 is an apparatus that electrolyzes raw water to generate hydrogen gas, and is connected to the degassing apparatus 20 by a pipe 62 through which the raw water is delivered, and has an outlet 70 for oxygen gas produced as a by-product in the electrolysis, and an outlet 72 for hydrogen gas produced in the electrolysis. The electrolyzer 30 is not particularly limited as long as it satisfies the above requirements, but it is preferable that the electrolyzer 30 has an electrolytic cell 32 as shown in FIG. 2 and is connected to the second oxygen gas supply device 50 via a pipe 66.

[0037] FIG. 2 is a schematic diagram of an electrolytic cell 32 according to one embodiment of the present invention. The electrolytic cell 32 has a structure in which an anode chamber 34 that houses an anode and a cathode chamber 36 that houses a cathode are adjacent to each other with an ion exchange membrane 38 interposed therebetween. The ion exchange membrane 38 is a membrane that is used to exchange hydrogen ions (H + ) is selectively permeated through the ion exchange membrane 38. + The ion exchange membrane 38 is not particularly limited as long as it has the above-mentioned functions.

[0038] (Second oxygen gas supply device) The second oxygen gas supplying device 50 is connected to the electrolyzer 30 by a pipe 66 and supplies oxygen gas to the electrolyzer 30. The second oxygen gas supplying device 50 may directly supply oxygen gas to the raw water in the electrolyzer 30, or may supply oxygen gas to a space in contact with the raw water in the electrolyzer 30 (purging the space with oxygen), or may be capable of both. When the electrolyzer 30 has an electrolytic cell 32, it is preferable that the second oxygen gas supplying device 50 supplies oxygen gas to the anode chamber 34 of the electrolytic cell 32. The second oxygen gas supplying device 50 is not particularly limited as long as it is a device capable of supplying oxygen gas, and a conventionally known device may be used.

[0039] (Plumbing) The hydrogen gas production system 100 preferably has a pipe 66 that connects the electrolyzer 30 and the second oxygen gas supply device 50 and defines a flow path through which oxygen gas is sent from the second oxygen gas supply device 50 to the electrolyzer 30. The material of the pipe 66 is not particularly limited, but since a material that is easily permeable to air components, such as resin, may impair the effect of oxygen gas purging, it is preferable to use a stainless steel or glass material that is not permeable to air components.

[0040] (Electrolysis process) The electrolysis step is a step in which the raw water degassed in the degassing step is electrolyzed in the electrolysis device 30 to generate hydrogen gas. When the electrolysis device 30 used in the electrolysis step has an electrolysis cell 32, it is preferable to supply oxygen gas from the second oxygen gas supply device 50 to the anode chamber 34 of the electrolysis cell 32. As a method for supplying oxygen gas, oxygen gas may be directly supplied to the raw water in the anode chamber 34, oxygen gas may be supplied to the space in the anode chamber 34 that contacts the raw water (the space is purged with oxygen gas), or both may be performed.

[0041] In the electrolysis step, when oxygen gas is purged from the second oxygen gas supply device 50 into the anode chamber 34, it is preferable to maintain a pressurized state of about atmospheric pressure or more and 100 kPaG or less. By performing electrolysis under a pressurized state, it is possible to reduce the intrusion of air components other than oxygen gas into the electrolyzer 30 due to the pressure difference. Since the purged oxygen gas is removed during the electrolysis process, purging oxygen gas into the anode chamber 34 makes it possible to obtain hydrogen gas with fewer impurities.

[0042] The hydrogen gas obtained by the electrolysis process may contain moisture as an impurity. By treating the hydrogen gas obtained by the electrolysis process with an appropriate moisture removal device, high-purity hydrogen gas from which moisture has been removed can be obtained.

[0043] In the electrolysis process, in the anode chamber 34 of the electrolysis cell 32, the raw water is decomposed into oxygen gas and hydrogen ions by the reaction shown in the following formula (1). The generated hydrogen ions permeate the ion exchange membrane 38 and move to the cathode chamber 36, where they become hydrogen gas by the reduction reaction shown in the following formula (2). Most of the oxygen gas does not permeate the ion exchange membrane 38, but even the very small amount of oxygen gas that does permeate reacts with the hydrogen ions under the reducing conditions of the cathode to become water, and is therefore not included in the hydrogen gas generated at the cathode. H2O → 1 / 2O2 + 2H + +2e - (1) 2H + +2e - →H2···(2)

[0044] In addition, when the raw water contains heavy water (DO), the hydrogen gas obtained by electrolysis of the heavy water is deuterium gas (D2). In addition, when the raw water contains semi-heavy water (HDO), the hydrogen gas obtained by electrolysis of the semi-heavy water is semi-deuterium gas (HD). When the raw water is deuterium-enriched water, the hydrogen gas obtained is also deuterium-enriched hydrogen gas (hydrogen gas having a higher abundance ratio of deuterium D than normal hydrogen gas). Since the raw material cost of heavy water is higher than that of general pure water, if the produced hydrogen gas is used as a purge gas for the degassing device as in Patent Document 2, a part of the produced hydrogen gas will be discarded, which will particularly increase the production cost. In contrast, in the present invention, oxygen gas is used as a purge gas, so high-purity hydrogen gas can be produced without reducing the recovery rate of the produced hydrogen gas.

[0045] (Hydrogen gas) The hydrogen gas production system and method described above can produce high-purity hydrogen gas. The gas produced by this embodiment has a composition in which 99.999 vol% or more of the volume fraction is hydrogen gas. The volume fraction of hydrogen gas produced by the present invention has no upper limit, but the volume fraction of hydrogen gas is usually 99.999999 vol% or less. The gas produced by the present invention may contain air components (one or more of argon gas, nitrogen gas, oxygen gas, and carbon dioxide gas) and moisture as impurities, but the air components are significantly reduced. The hydrogen gas produced can be further treated by an appropriate moisture removal device to produce high-purity hydrogen gas from which moisture has also been removed.

[0046] The volume fraction of hydrogen gas and impurities in the gas obtained by the present invention can be calculated by analyzing the obtained gas using a gas chromatograph analyzer (e.g., manufactured by Shimadzu Corporation) and comparing the peak area values ​​with those of a standard gas.

[0047] In addition, by using deuterium enriched water as the raw water, hydrogen gas enriched in D can be obtained. When the content ratio of deuterium (D) in the total hydrogen atoms in the hydrogen gas obtained by the present invention is 90 [atom%D] or more, it is generally expected that the performance (improved yield, etc.) will be improved compared to hydrogen (H) when used in industrial applications. Therefore, the content ratio of deuterium (D) in the total hydrogen atoms in the obtained hydrogen gas is preferably 90 [atom%D] or more. On the other hand, the upper limit of the content ratio of deuterium (D) in the total hydrogen atoms in the obtained hydrogen gas is not particularly limited, but from an industrial point of view, the content ratio of D in the total hydrogen atoms in the obtained hydrogen gas is approximately 99.99 [atom%D] or less. The content ratio of deuterium (D) in the total hydrogen atoms in the hydrogen gas can be determined in the same manner as for the raw water.

[0048] Regarding steps and conditions not described in the present invention, conventional methods can be used. EXAMPLES

[0049] [Example 1] Using the apparatus shown in FIG. 1, raw water (5 L of pure water) was degassed by purging oxygen gas (10 L / min) under a reduced pressure of 20 hPa at 35°C for 1 hour. The degassed raw water was then sent to an electrolysis apparatus, and electrolysis was carried out under pressure (10 kPaG) with oxygen purged into the anode chamber. The hydrogen gas obtained by electrolysis was analyzed by the method described above using a gas chromatograph analyzer (manufactured by Shimadzu Corporation). Table 1 shows the composition analysis results of the gas obtained in each example.

[0050] [Example 2] Hydrogen gas was generated in the same manner as in Example 1, except that in the electrolysis step, the anode chamber of the electrolysis cell was neither purged with oxygen nor pressurized.

[0051] [Example 3] Hydrogen gas was generated in the same manner as in Example 1, except that the raw water was changed from pure water to deuterium-enriched water (D abundance ratio: 99.9 atom % D).

[0052] [Comparative Example 1] Hydrogen gas was generated in the same manner as in Example 1, except that oxygen gas purging in the degassing step was not performed.

[0053] [Comparative Example 2] Hydrogen gas was generated in the same manner as in Example 1, except that the purge gas in the degassing step was changed to air.

[0054] In the examples where purging with oxygen gas was performed in the degassing process, high-purity hydrogen gas with a volume fraction of hydrogen gas of 99.999 vol% or more was obtained. On the other hand, the gas obtained in the comparative example where purging with oxygen gas was not performed in the degassing process had a lower volume fraction of hydrogen gas than the examples.

[0055] [Table 1] [Explanation of symbols]

[0056] 100 Hydrogen gas production system 10 Raw water supply tank 20 Deaeration device 30 Electrolysis Apparatus 32 Electrolysis Cell 34 Anode chamber 36 Cathode Chamber 38 Ion exchange membrane 40 First oxygen gas supply device 50 Second oxygen gas supply device 60 Piping 62 Piping 64 Piping 66 Piping 70 Oxygen gas outlet 72 Hydrogen gas outlet

Claims

1. A degassing device for degassing raw water; an electrolysis device that electrolyzes the raw water degassed by the degassing device to generate hydrogen gas; a pipe connecting the degassing device and the electrolyzer and defining a flow path through which the raw water is sent from the degassing device to the electrolyzer; a first oxygen gas supply device that supplies oxygen gas as a degassing gas to the degassing device; A hydrogen gas production system having the above structure.

2. the electrolysis device has an electrolysis cell in which an anode chamber accommodating an anode and a cathode chamber accommodating a cathode are adjacent to each other via an ion exchange membrane; The hydrogen gas production system according to claim 1 , further comprising a second oxygen gas supply device that supplies oxygen gas to the anode chamber.

3. The raw water contains heavy water, The hydrogen gas production system according to claim 1 or 2, wherein the hydrogen gas generated in the electrolysis device contains deuterium gas.

4. a degassing step of degassing the raw water in a degassing device; Thereafter, the raw water is sent from the degassing device to an electrolysis device through a pipe; an electrolysis step of electrolyzing the raw water degassed in the degassing step in the electrolysis device to generate hydrogen gas; having The method for producing hydrogen gas, wherein the raw water is degassed using oxygen gas in the degassing step.

5. the electrolysis device has an electrolysis cell in which an anode chamber accommodating an anode and a cathode chamber accommodating a cathode are adjacent to each other via an ion exchange membrane; The method for producing hydrogen gas according to claim 4 , wherein in the electrolysis step, the anode chamber is purged with oxygen gas.

6. The raw water contains heavy water, 6. The method for producing hydrogen gas according to claim 4, wherein the hydrogen gas generated in the electrolysis step contains deuterium gas.

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