Deuterium recovery device and deuterium recovery method

Abstract

A PEM type deuterium recovery device that recovers deuterium with high efficiency is obtained. [Solution] An MEA (Electrode Assembly) 10 is used, which combines two electrodes (a first catalytic electrode 11 and a second catalytic electrode 12) to which a DC voltage is applied and a proton-conducting layer 20 sandwiched between them. Here, the first catalytic electrode 11 side is positive, and the second catalytic electrode 12 side is negative. The first catalytic electrode 11 side is an anode chamber 31 to which deuterium (D) to be recovered is supplied together with hydrogen (H) as a liquid (raw water W0) in the form of water. The second catalytic electrode 12 side is a cathode chamber 32 to which water (recovered water W1) separate from the raw water W0 is stored in contact with the second catalytic electrode 12. Due to a reaction in the cathode chamber 32, the D component of H and D is preferentially captured into the recovered water W1. This allows D to be recovered in this water. By using water with a lower D concentration than the raw water W0 as the recovered water W1, D can be recovered with particularly high efficiency.

Description

[Technical Field]

[0001] The present invention relates to hydrogen ( 1 The present invention relates to a deuterium recovery device and a deuterium recovery method that selectively recover deuterium from a mixture of hydrogen (H) and deuterium. [Background technology]

[0002] A stable isotope of hydrogen that is a component of naturally occurring water and hydrogen gas has a mass number of 1 (the nucleus consists of only one proton). 1 H (hereafter referred to as H) and deuterium, which has a mass number of 2 (the nucleus consists of one proton and one neutron). 2 There is H (hereafter referred to as D), and the abundance ratio of D is overwhelmingly smaller than that of H. H and D have almost the same chemical properties, but D is known to be particularly effective in applications in the nuclear power and semiconductor manufacturing fields. For this reason, there is a demand for technology to selectively recover (separate) D from water or hydrogen gas, which contains a mixture of H and D. However, since it is virtually impossible to completely separate H and D instantly, in reality, materials containing a mixture of these elements (water, hydrogen gas, etc.) are treated to increase the concentration of one of them (especially D) in order to separate them.

[0003] Electrolysis is a known method for separating H and D from liquid water. In electrolysis, H (light water) and D (heavy water) are separated due to the difference in decomposition speed when water is electrolyzed. In this case, D is recovered by extracting the H in the water as hydrogen gas (H2) and extracting the D as water (heavy water). Based on this principle, the basic configuration of a deuterium recovery device using electrolysis is the same as that of a hydrogen generation device that produces hydrogen gas by water electrolysis, and if hydrogen gas can be produced with high efficiency, D can also be recovered with high efficiency at the same time.

[0004] The configuration of such a hydrogen generator is described, for example, in Non-Patent Document 1. Among typical forms of hydrogen generators, types that can also be used as deuterium recovery devices include alkaline water electrolysis types and PEM (polymer electrolyte membrane) types.

[0005] In alkaline water electrolysis systems, the water used as the raw material for hydrogen gas and D is used in the form of an alkaline aqueous solution, which is then electrolyzed, whereas in PEM electrolysis systems, the raw water is used as is. PEM electrolysis systems use a polymer electrolyte membrane (PEM) that allows hydrogen ions to pass through, and have a structure similar to that of a fuel cell that generates electricity from hydrogen gas, but instead generate hydrogen gas by applying a voltage to the electrodes, in contrast to a fuel cell.

[0006] The configuration of a PEM electrolysis device is described, for example, in Patent Document 1. In this device, electrodes are formed on both sides of a PEM (proton-exchange membrane) that conducts hydrogen ions. The electrodes are made of a catalyst containing a precious metal such as iridium (Ir), ruthenium (Ru), or platinum (Pt), an alloy containing these precious metals, or an oxide thereof (e.g., IrO2, RuO2), with one electrode serving as the positive side and the other as the negative side. With this configuration, when water is applied to the positive catalytic electrode, hydrogen gas is generated at the negative catalytic electrode, and D is also extracted. In practice, the catalytic electrode / PEM / catalytic electrode structure can be integrated into a membrane electrode assembly. This type of membrane electrode assembly is used not only when the anode (input) side is a liquid (water), but also in a device in which the input side is a gas (hydrogen gas) containing a mixture of H2 and D, and D is recovered at the cathode (output) side, as described in Patent Document 2. [Prior art documents] [Non-patent literature]

[0007] [Non-Patent Document 1] "Recommendations for Future Initiatives for Hydrogen-Related Projects," Recommendations for Future Initiatives for Hydrogen-Related Projects (Ministry of Economy, Trade and Industry), December 19, 2022: https: / / www.meti.go.jp / shingikai / energy_environment / 2050_carbon_neutral / pdf / 001_04_00.pdf [Patent documents]

[0008] [Patent Document 1] Patent No. 7378005 [Patent Document 2] Japanese Patent Application Laid-Open No. 2024-76690 Summary of the Invention [Problem to be solved by the invention]

[0009] While deuterium recovery systems using alkaline water electrolysis devices achieved high D recovery efficiencies due to their high hydrogen production capacity, deuterium recovery systems using PEM electrolysis devices achieved lower recovery efficiencies. Alkaline water electrolysis systems, on the other hand, have drawbacks, such as the need for alkaline electrolytes and associated equipment to create the solution, and the need for countermeasures against the potential reaction between oxygen gas generated on the anode and cathode sides. In contrast, PEM electrolysis systems have the advantages of a simple structure, the ability to supply raw water directly without the need to add electrolytes to it, and the fact that the anode and cathode sides are separated by a PEM, which prevents gases from passing through, making such gas reactions less likely to occur, simplifying the overall system structure.

[0010] For this reason, a PEM-type device that can recover deuterium with high efficiency was required.

[0011] The present invention has been made in view of the above problems, and an object of the present invention is to provide an invention that solves the above problems. [Means for solving the problem]

[0012] In order to solve the above problems, the present invention has the following configurations. The deuterium recovery device of the present invention uses hydrogen ( 1 a first catalytic electrode formed on one of the main surfaces of the proton conducting layer and having a positive voltage, and a second catalytic electrode formed on the other main surface of the proton conducting layer and having a negative voltage, and a second catalytic electrode formed on the other main surface of the proton conducting layer and having a negative voltage, and The system comprises an anode chamber provided on the side of the first catalytic electrode so that the first catalytic electrode and the raw water are in contact with each other, and a cathode chamber in which the recovered water is stored so that the second catalytic electrode and the recovered water are in contact with each other, wherein the deuterium that flows as ions from the anode chamber to the cathode chamber is recovered by a liquid-phase chemical exchange reaction with the recovered water, and the recovered water is then extracted from the cathode chamber, and the concentration ratio of deuterium to hydrogen is set higher in the raw water than in the recovered water before the deuterium is recovered. The first catalytic electrode may include particles of a noble metal, such as ruthenium (Ru) or iridium (Ir), or an alloy containing the noble metal, or particles of iridium oxide (IrO2) or ruthenium oxide (RuO2). The second catalytic electrode may contain particles of a noble metal selected from platinum (Pt), palladium (Pd), ruthenium (Ru), rhodium (Rh), iridium (Ir), and gold (Au), or an alloy containing the noble metal. The recovered water from which the deuterium has been recovered may be transported from the cathode chamber to the anode chamber and mixed with the raw water. The deuterium is deuterium ( 2 H or D), or tritium ( 3 H or T). The deuterium recovery method of the present invention is a method for recovering hydrogen ( 1a first catalytic electrode formed on one of the main surfaces of the proton conducting layer; and a second catalytic electrode formed on the other main surface of the proton conducting layer. A deuterium recovery method for recovering deuterium from raw water, which is a liquid containing a mixture of protons (H) and deuterium, an isotope of hydrogen, into recovered water, a liquid containing hydrogen, separate from the raw water, is characterized by: A membrane electrode assembly is used, the membrane electrode assembly having: a proton conducting layer made of a proton conductor that conducts positive hydrogen ions and having two opposing main surfaces; a first catalytic electrode formed on one of the main surfaces of the proton conducting layer; and a second catalytic electrode formed on the other main surface of the proton conducting layer; The first catalytic electrode is in contact with the raw water, and the second catalytic electrode is in contact with the recovered water. A voltage is applied to the first catalytic electrode as a positive side and the second catalytic electrode as a negative side, with the first catalytic electrode in contact with the raw water and the second catalytic electrode in contact with the recovered water; The deuterium ions flow from the first catalytic electrode side to the second catalytic electrode side. The recovered water is recovered by a liquid-phase chemical exchange reaction between the deuterium ions and the recovered water, and the recovered water is then extracted. The concentration ratio of deuterium to hydrogen in the raw water is set to be higher than that in the recovered water before the deuterium is recovered. The first catalytic electrode may include particles of a noble metal, such as ruthenium (Ru) or iridium (Ir), or an alloy containing the noble metal, or particles of iridium oxide (IrO2) or ruthenium oxide (RuO2). The second catalytic electrode may contain particles of a noble metal selected from platinum (Pt), palladium (Pd), ruthenium (Ru), rhodium (Rh), iridium (Ir), and gold (Au), or an alloy containing the noble metal. The recovered water from which the deuterium has been recovered may be transported from the second catalytic electrode side to the first catalytic electrode side and mixed with the raw water. The deuterium is deuterium ( 2 H or D), or tritium ( 3 H or T). [Effects of the Invention]

[0013] Since the present invention is configured as described above, it is possible to recover deuterium with high efficiency using a PEM type configuration. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a diagram showing a configuration of a hydrogen isotope recovery device according to an embodiment of the present invention. [Figure 2] 1 shows the results of measuring the deuterium separation ability α in an example and a comparative example of the hydrogen isotope recovery device according to the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] The following describes a deuterium recovery device and a deuterium recovery method according to an embodiment of the present invention. This deuterium recovery device selectively recovers D from raw water containing a mixture of H and D, and incorporates and recovers it in water. This allows for the production of water containing a high concentration of D (high D / H abundance ratio).

[0016] In this deuterium recovery device and deuterium recovery method, a membrane electrode assembly (MEA) is used as a basic component, similar to the device described in Patent Document 2. FIG. 1 is a diagram showing a schematic configuration of this deuterium recovery device 1. This configuration uses an MEA 10 that combines two electrodes (a first catalytic electrode 11 and a second catalytic electrode 12) to which a DC voltage is applied, and a proton conductive layer 20 sandwiched between them. Here, a DC voltage is applied between the first catalytic electrode 11 and the second catalytic electrode 12, with the first catalytic electrode 11 side being positive and the second catalytic electrode 12 side being negative.

[0017] The proton conducting layer 20 may be made of a material that is a conductor of H ions and D ions (proton conductor), such as Nafion (registered trademark). These ions flow through the proton conducting layer 20 from left to right in the drawing, and an oxidation reaction occurs again at the second catalytic electrode 12. The thickness of the proton conducting layer 20 is set to, for example, a range of 25 μm to 200 μm.

[0018] For the first catalytic electrode 11, catalytic materials contributing to water electrolysis include precious metals such as iridium (Ir) and ruthenium (Ru), alloys containing these metals, and oxides of these metals (e.g., IrO2, RuO2), for example, iridium oxide (IrO2). For the second catalytic electrode 12, catalytic materials contributing to the LPCE reaction described below include precious metals such as platinum (Pt), palladium (Pd), ruthenium (Ru), rhodium (Rh), iridium (Ir), and gold (Au), or alloys containing these precious metals. For both electrodes, the above-mentioned materials that function as catalysts are used in a form that combines the functions of an electrode and a catalyst. For the second catalytic electrode 12, particles made of the above-mentioned materials (e.g., Pt nanoparticles (powder)) are supported on a carbon-based material, increasing the surface area of ​​the Pt and enhancing the catalytic activity (Pt / C). In this case, the content of the catalyst (e.g., Pt) is 0.1 to 2.0 mg / cm. 2 The first catalytic electrode 11 may also be made of the above materials in a similar form.

[0019] The above configuration is similar to the technology described in Patent Document 2. However, here, the configurations of the side in contact with the first catalytic electrode 11 and the side in contact with the second catalytic electrode 12 are significantly different.

[0020] In FIG. 1, the side of the first catalytic electrode 11 is the anode chamber 31 to which the deuterium (D) to be recovered is supplied as a liquid (raw water W0) in the form of water together with hydrogen (H). The raw water W0 contains H and D in the form of HO, HDO, DO, etc., and this raw water W0 is introduced through an inlet 31A. This raw water W0 is electrolyzed by the deuterium recovery device 1. As a result, the amount of raw water W0 decreases as the process progresses, and oxygen (O) gas is generated accordingly. The remaining raw water W0 and a gas containing oxygen gas exist separately in the anode chamber 31. The remaining raw water W0 is discharged from an outlet 31B, and the gas components are discharged from an outlet 31C.

[0021] On the other hand, H and D produced by the decomposition of water by the first catalytic electrode 11 are ionized (positive ions) and flow through the proton conducting layer 20 toward the second catalytic electrode 12, where they become gases (hydrogen gas) such as H2, HD, and D2 on the surface of the second catalytic electrode 12.

[0022] 1, the second catalytic electrode 12 side is a cathode chamber 32 in which water (recovered water W1) separate from the raw water W0 is stored in contact with the second catalytic electrode 12. For this reason, the cathode chamber 32 is provided with an inlet 32A through which water is introduced and an outlet 32B through which water (liquid) is discharged. In addition to the outlet 32B, an outlet 32C through which gas components generated in the cathode chamber 32 are discharged is also provided.

[0023] In this deuterium recovery device 1, the D component of H and D is preferentially incorporated into the recovered water W1 by the reaction in the cathode chamber 32, while the H component is removed as a gas. This allows D to be recovered in the water.

[0024] This principle will be explained. First, in FIG. 1, when recovered water W1 is not introduced into the cathode chamber 32, H2, HD, and D2 are formed as gases on the second catalytic electrode 12 (catalyst) by the H and D ions that have migrated to the second catalytic electrode 12. On the other hand, even when recovered water W1 is not introduced into the cathode chamber 32, a small amount of raw water W0 in the anode chamber 31 flows toward the cathode chamber 32 as a permeate flow (permeate water) due to the flow of H ions and D ions. Therefore, the cathode chamber 32 actually contains gas components H2, HD, and D2, as well as small amounts of liquid components H2O, HDO, and D2O. However, when these liquid components exist on the second catalytic electrode 12, the gas components are generated and exist as small bubbles (nanobubbles) within the nanobubbles, and the surrounding liquid (water) components exist as water vapor within the nanobubbles. This can lead to reactions between the gas components and the water vapor.

[0025] Here, a reaction (vapor phase chemical exchange reaction: VPCE reaction) occurs between HD, which exists as a gas, and H2O, which exists as water vapor, as shown in the following reaction formula (1).

[0026]

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[0027] Here, (g) indicates the gas phase. HD(g) on ​​the left side is a component supplied from raw water W0 and produced on the catalyst, and HO(g) on ​​the left side is a component produced from the permeated water. In reality, the reaction from the left side to the right side in reaction equation (1) and the reaction from the right side to the left side occur simultaneously, resulting in an equilibrium state.

[0028] The D in the HDO(g) produced on the right side is the D in the HD(g) on ​​the left side, and this HDO(g) is produced by replacing one H in the HO(g) on ​​the left side with D. Meanwhile, the H in the HD(g) on ​​the left side combines with the H in the HO(g) that replaced D on the right side to form H(g). Therefore, in reaction equation (1), if the reaction from the left side to the right side prevails and equilibrium is reached, HDO(g) on ​​the right side is produced. If this HDO(g) is separated from H(g) and extracted, the D in the HD(g) in the raw water W0 is incorporated, and the H in the HD(g) is removed. Consequently, the H and D in the HD(g) on ​​the left side are separated by the reaction from the left side to the right side. In the technology described in Patent Document 2, the raw material is supplied as a gas, but the principle of separating D and H is similar. That is, D can be recovered using the VPCE reaction in the cathode chamber 32.

[0029] Here, HDO(g) on ​​the right side of reaction formula (1) undergoes the reaction shown in reaction formula (2) below in the presence of liquid H2O.

[0030]

number

[0031] Here, (l) indicates the liquid phase. HDO(g) on ​​the left side corresponds to the right side of reaction equation (1), and HO(l) corresponds to the permeated water mentioned above. In this case, HDO(g) and HO(l) on the left side change phase to HDO(l) and HO(g) on ​​the right side, respectively. The reaction combining the reactions of reaction equation (1) and reaction equation (2) is a liquid-phase chemical exchange reaction (LPCE reaction).

[0032] In this case, the D in HD(g) on ​​the left side of reaction equation (1) is taken up into the liquid-phase HDO(l) on the right side of reaction equation (2), while the H in this HD(g) is removed as H2(g) on ​​the right side of reaction equation (1). Therefore, when the reaction from the left side to the right side of reaction equation (1) prevails, D can be recovered as HDO(g), whereas when the reaction from the left side to the right side of reaction equation (2) prevails in addition to this reaction, D can be recovered as HDO(l).

[0033] Specifically, this HDO(l) is the permeate water after D has been absorbed (corresponding to HO(l) on the left side). Since the permeate water before D is absorbed is actually part of the raw water W0 in the anode chamber 31, the D concentration in the permeate water before D is absorbed according to reaction formula (2) is equal to that of raw water W0. In other words, using the above reaction formulas (1) and (2), the D in raw water W0 can be recovered as water with a higher D concentration than raw water W0.

[0034] In reaction equation (1), D exists only in the form of HD(g) on ​​the left side. However, if, for example, D2(g) exists and HD(g) on ​​the left side of reaction equation (1) is replaced with D2(g), H2(g) on ​​the right side is replaced with HD(g). In this case, this HD(g) becomes HD(g) on ​​the left side of reaction equation (1), and ultimately, the reaction of reaction equation (1) is realized in this case as well. In other words, gas-phase chemical exchange reactions and liquid-phase chemical exchange reactions also occur for D2.

[0035] Here, the inventors have found that the reaction from the left side to the right side of reaction formula (1) and reaction formula (2) is highly dependent on the D concentration of the water containing the HO(l) on the left side. Specifically, in Figure 1, by lowering the D concentration of recovered water W1 introduced into the cathode chamber 32 separately from the permeate water, the reaction from the left side to the right side of reaction formula (1) and reaction formula (2) becomes dominant, and a large amount of HDO(l) can be produced.

[0036] The experimental results on this point will be explained below. In the configuration of Fig. 1, the same MEA was used for all examples and comparative examples. Nafion212 (product name: Chemours) was used as the proton conductive layer 20, and 1.0 mg / cm of IrO2 catalyst supported on oxide was used as the first catalytic electrode 11. 2 (Ir weight) was used as an electrode, and the second catalytic electrode 12 was made of the Pt / C catalyst at 0.5 mg / cm 2 (Pt by weight) was used. The potential difference between the first catalytic electrode 11 and the second catalytic electrode 12 was set to about 2 V. The temperature during the reaction was set to room temperature (23° C.).

[0037] As the raw water W0, a mixed water of 45 ml of H2O and 5 ml of D2O (D concentration (molar concentration of D relative to the sum of D and H) of 10%) was used. On the other hand, as the recovered water W1 introduced into the cathode chamber 32, water with a D concentration of 0.015% (hereinafter referred to as 0%) (Example 1), 5% (Example 2), 10% (Comparative Example 1), or 20% (Comparative Example 2) was used.

[0038] According to the above reaction equations (1) and (2), the amount of H generated in the cathode chamber 32 reflects the amount of D recovered in the liquid. The gases evaluated here were H, HD, and D generated in the cathode chamber 32. The ratio of H to D, H / D, was defined as R2, and the ratio of H to D, such as HO, HDO, and DO contained in the raw water W0, was defined as R1. α = R2 / R1 was calculated. When α = 1 (R1 = R2), this means that the ratio of H to D on the anode chamber 31 side (input side) is the same as the ratio of H to D in the gas on the cathode chamber 32 side (output side). This means that the H / D ratio remains unchanged, and D is not, at least selectively, being incorporated into the liquid (water) on the cathode chamber 32 side (output side). On the other hand, when α > 1, this means that the D concentration in the air in the cathode chamber 32 is lower than that in the raw water W0, which conversely means that the D concentration in the liquid is increased. Therefore, the above α can be used as an index of the recovery rate of D (separation ability).

[0039] In Example 2 and Comparative Examples 1 and 2, the D concentrations in recovered water W1 introduced into the cathode chamber 32 were set to 5%, 10%, and 20%. In these cases, the absolute value of the D concentration in the liquid at the time of measurement varies greatly depending on the original D concentration, but the evaluation using α is similarly effective because only the D newly taken into the liquid is evaluated in the evaluation using α.

[0040] Furthermore, the results were also measured when no recovered water W1 was introduced as Comparative Example 3. In Comparative Example 3, only permeated water having the same D concentration as the raw water W0 was present.

[0041] FIG. 2 shows the results of measuring α in the above comparative examples and examples. These results clearly show that a particularly high separation ability α can be obtained when the D concentration in the recovered water W1 is low. This indicates that the lower the D concentration in the recovered water W1, the more dominant the reaction from the left side to the right side in reaction equations (1) and (2). The results of comparative example 3 (when recovered water W1 is not used) and comparative example 1 (when the D concentrations in recovered water W1 and raw water W0 are equal) are comparable. In comparative example 2, where the D concentration in recovered water W1 is lower than that in raw water W0, the separation ability α was lower than in comparative example 3 (when recovered water W1 is not used).

[0042] However, in Figure 2, α > 1 in all comparative examples and examples. This means that in all comparative examples and examples, the D concentration was higher in the recovered water W1 than in the raw water W0.

[0043] That is, in the configuration of Figure 1, when raw water W0 is introduced into the anode chamber 31 and recovered water W1 is introduced into the cathode chamber 32, D can be recovered in the recovered water W1 even if the D concentration in the recovered water W1 (recovering side) is higher than that in the raw water W0 (recovered side). However, by using water with a lower D concentration than the raw water W0 as the recovered water W1, D can be recovered with particularly high efficiency.

[0044] In this case, as the reaction progresses, raw water W0 is electrolyzed and reduced in the anode chamber 31. Meanwhile, recovered water W1, whose D / H ratio has been increased due to the recovery of D, is added to the anode chamber 31 to produce new raw water W0, and new recovered water W1 with a low D concentration can be introduced into the cathode chamber 32. This operation makes the D concentration in raw water W0 higher than before the reaction. If the reaction is carried out again in this state, the difference between the D concentration in raw water W0 and the D concentration in recovered water W1 will be larger than in the previous reaction, making it possible to increase the D recovery efficiency compared to the previous reaction, and further increasing the D concentration in recovered water W1 after the reaction.

[0045] That is, in the above-described deuterium recovery apparatus 1, since liquid (water) is used on both the raw material side and the recovery side, D can be recovered more efficiently by adding recovered water W1 after the reaction to the water on the raw material water W0 side that has been reduced after the reaction, and introducing new recovered water W1 with a low D concentration into the cathode chamber 32 and causing the reaction to occur again. This operation can be repeated as needed, and thereby recovered water W1 with a high D concentration can finally be obtained.

[0046] In this case, the timing for returning the recovered water W1 to the raw material side can be appropriately set depending on the D concentration of the raw material water W0, the D concentration of the recovered water W1 that is finally required, etc. In other words, using the above-described deuterium recovery apparatus 1, heavy water with a substantially increased D concentration in the water can be obtained.

[0047] In the above example, deuterium ( 2 H, D) is hydrogen ( 1 It has been shown that deuterium can be recovered from a gas mixture containing tritium (H, H). 3 It is clear that hydrogen isotopes (H, T) can be recovered in a similar manner. The same is true for other hydrogen isotopes. [Explanation of symbols]

[0048] 1. Deuterium recovery device 10 Membrane electrode assembly (MEA) 11 First catalyst electrode 12 Second catalyst electrode 20 Proton Conducting Layer 31 Anode chamber 31A, 32A inlet 31B, 31C, 32B, 32C outlet 32 Cathode Chamber W0 raw water W1 Reclaimed water

Claims

1. hydrogen( １ 1. A deuterium recovery apparatus for recovering deuterium from raw water, which is a liquid containing a mixture of hydrogen (H) and deuterium, an isotope of hydrogen, into recovered water, which is a liquid containing hydrogen and is separate from the raw water, a proton conducting layer made of a proton conductor that conducts positive hydrogen ions and having two opposing main surfaces; a first catalytic electrode formed on one of the main surfaces of the proton conducting layer and applied with a positive voltage; a second catalytic electrode formed on the other main surface of the proton conducting layer and having a negative voltage; a membrane electrode assembly having an anode chamber provided on the first catalytic electrode side so that the first catalytic electrode and the raw water come into contact with each other; a cathode chamber in which the recovered water is stored so that the recovered water is in contact with the second catalytic electrode, the deuterium ions that have flowed from the anode chamber to the cathode chamber are recovered by a liquid-phase chemical exchange reaction with the recovered water, and the recovered water is then taken out from the cathode chamber; a concentration ratio of the deuterium to the hydrogen in the raw water being set higher than that in the recovered water before the deuterium is recovered;

2. The first catalytic electrode is made of a noble metal selected from ruthenium (Ru) and iridium (Ir), or an alloy containing the noble metal, or iridium oxide (IrO ２ ), ruthenium oxide (RuO ２ 2. The deuterium recovery device according to claim 1, wherein the deuterium recovery device contains particles made of either one of:

3. 2. The deuterium recovery device according to claim 1, wherein the second catalytic electrode contains particles made of a noble metal selected from platinum (Pt), palladium (Pd), ruthenium (Ru), rhodium (Rh), iridium (Ir), and gold (Au), or an alloy containing the noble metal.

4. 3. The deuterium recovery device according to claim 1, wherein the recovered water from which the deuterium has been recovered is transported from the cathode chamber to the anode chamber and mixed with the raw water.

5. The deuterium is deuterium ( ２ H or D), or tritium ( ３ 3. The deuterium recovery device according to claim 1, wherein the deuterium recovery device is a deuterium recovery device.

6. hydrogen( １ 1. A deuterium recovery method for recovering deuterium from raw water, which is a liquid containing a mixture of hydrogen (H) and deuterium, an isotope of hydrogen, into recovered water, which is a liquid containing hydrogen and is separate from the raw water, comprising: a proton conducting layer made of a proton conductor that conducts positive hydrogen ions and having two opposing main surfaces; a first catalytic electrode formed on one of the main surfaces of the proton conducting layer; a second catalytic electrode formed on the other main surface of the proton conducting layer; A membrane electrode assembly having applying a voltage to the first catalytic electrode as a positive side and the second catalytic electrode as a negative side in a state in which the first catalytic electrode is in contact with the raw water and the second catalytic electrode is in contact with the recovered water; the deuterium ions that have flowed from the first catalytic electrode side to the second catalytic electrode side are recovered by a liquid-phase chemical exchange reaction with the recovered water, and the recovered water is then taken out; A method for recovering deuterium, characterized in that a concentration ratio of the deuterium to the hydrogen is set higher in the raw water than in the recovered water before the recovery of the deuterium.

7. The first catalytic electrode is made of a noble metal selected from ruthenium (Ru) and iridium (Ir), or an alloy containing the noble metal, or iridium oxide (IrO ２ ), ruthenium oxide (RuO ２ 7. The method for recovering deuterium according to claim 6, wherein the particles comprise either one of:

8. 8. The method for recovering heavy hydrogen according to claim 6, wherein the second catalytic electrode contains particles made of a noble metal selected from platinum (Pt), palladium (Pd), ruthenium (Ru), rhodium (Rh), iridium (Ir), and gold (Au), or an alloy containing the noble metal.

9. 8. The method for recovering deuterium according to claim 6, wherein the recovered water from which the deuterium has been recovered is transported from the second catalytic electrode side to the first catalytic electrode side and mixed with the raw water.

10. The deuterium is deuterium ( ２ H or D), or tritium ( ３ 8. The method for recovering deuterium according to claim 6, wherein the deuterium is H or T.

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