Method and system for recycling hydrogen isotope in metal through electric drive

Abstract

The invention provides a method and a system for electrically driving and recycling hydrogen isotopes in metal. The method comprises the following steps: taking metal containing hydrogen isotope as a working electrode; the working electrode and the counter electrode are arranged in the electrolyte, and voltage is applied between the counter electrode and the working electrode, so that hydrogen isotopes in the metal are subjected to oxidation reaction and are diffused to the surface of the metal, and the hydrogen isotopes are recovered. The hydrogen isotope in the metal is promoted to be subjected to oxidation reaction and diffused to the surface of the metal by utilizing the voltage between the counter electrode and the working electrode so as to recover the hydrogen isotope, and the method can be used for recovering the hydrogen isotope or reducing or repairing hydrogen-induced damage of the metal.

Description

Technical Field

[0001] The present invention specifically relates to a method for electrically driving the recovery of hydrogen isotopes in metals and a system for electrically driving the recovery of hydrogen isotopes in metals. Background Art

[0002] Hydrogen embrittlement occurs when hydrogen invades the metal, causing the metal's ductility and strength to decrease, which has an adverse effect on the performance and service life of metal materials and components. Currently, metals are widely used in many fields such as nuclear power plants, natural gas pipelines, power plants, new energy vehicles, and ships. In these application scenarios, the introduction of hydrogen and hydrogen isotopes can cause hydrogen-induced damage to the metal. Especially in the field of nuclear energy, because of the use of hydrogen isotopes, it is necessary to recover hydrogen isotopes.

[0003] At present, the commonly used treatment method is heating. Among them, the heating method requires heating the metal to hundreds of degrees. Although this process can effectively recover hydrogen isotopes (especially the expensive tritium), for non-detachable metals, the heating method may not be carried out due to their integrity and structural limitations. For detachable metals, the heating method may cause damage to the metal structure.

[0004] Therefore, it is necessary to develop a method that can recover hydrogen isotopes at low temperature, or can reduce or repair hydrogen-induced damage to metals. Summary of the invention

[0005] The present invention aims to solve the problem that the prior art cannot solve the low-temperature recovery of hydrogen isotopes in metals, or reduce or repair hydrogen-induced damage to metals, and provides a method and system for electrically driven recovery of hydrogen isotopes in metals.

[0006] The technical method of the present invention is as follows:

[0007] A method for electrically driving the recovery of hydrogen isotopes in metals, the method comprising: using a metal containing hydrogen isotopes as a working electrode; arranging the working electrode and a counter electrode in an electrolyte, applying a voltage between the counter electrode and the working electrode, causing the hydrogen isotopes in the metal to undergo an oxidation reaction and diffuse toward the metal surface, so as to recover the hydrogen isotopes.

[0008] The oxidation reaction takes place at normal pressure.

[0009] The electrolyte includes a liquid electrolyte, a solid electrolyte or a gel electrolyte.

[0010] The recovering of hydrogen isotopes includes: the hydrogen isotopes are present in a liquid electrolyte, a solid electrolyte or a gel electrolyte or escape in other forms.

[0011] The metal includes one or more of iron, steel, stainless steel, nickel, cobalt, aluminum, magnesium, zirconium, tungsten, titanium, molybdenum, tantalum, niobium, rare earth metals or alloys thereof.

[0012] The material of the counter electrode includes one or more of platinum, palladium, nickel, titanium, molybdenum, silver or alloys thereof, carbon materials or composite materials thereof.

[0013] The hydrogen isotope is one of protium, deuterium and tritium.

[0014] The present invention provides an electrically driven system for recovering hydrogen isotopes in metals, comprising: a metal containing hydrogen isotopes, a counter electrode and an electrolyte; the metal containing hydrogen isotopes and the counter electrode are arranged in the electrolyte, a voltage is applied between the counter electrode and the working electrode, and the hydrogen isotopes in the metal are induced to undergo an oxidation reaction and diffuse to the metal surface, so as to recover the hydrogen isotopes.

[0015] The electrolyte includes a liquid electrolyte, a solid electrolyte or a gel electrolyte.

[0016] The metal includes one or more of iron, steel, stainless steel, nickel, cobalt, aluminum, magnesium, zirconium, tungsten, titanium, molybdenum, tantalum, niobium, rare earth metals or alloys thereof.

[0017] The beneficial effects of the present invention are:

[0018] The present invention utilizes the voltage between the counter electrode and the working electrode to promote the oxidation reaction of hydrogen isotopes in the metal and diffuse them to the metal surface to recover the hydrogen isotopes. This method can be used to recover hydrogen isotopes or to reduce or repair hydrogen-induced damage to the metal. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a graph of deuterium desorption data in Example 1 of the present invention;

[0020] Figure 2 This is a graph of deuterium desorption data in Example 2 of the present invention;

[0021] Figure 3 This is a schematic diagram of the electrically driven system for recovering hydrogen isotopes in metals in Example 3 of the present invention;

[0022] Figure 4 This is a graph of deuterium desorption data in Example 3 of the present invention. DETAILED DESCRIPTION

[0023] The technical solution of the present invention is described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] In the prior art, hydrogen in the metal substrate includes mobile hydrogen isotopes, hydrogen isotopes with lower adsorption energy, and hydrogen isotopes with higher adsorption energy. The method of the present invention can recover not only mobile hydrogen isotopes and hydrogen isotopes with lower adsorption energy in the metal substrate, but also hydrogen isotopes with higher adsorption energy.

[0025] Therefore, the present invention provides a method for electrically driving the recovery of hydrogen isotopes in metals, the method comprising:

[0026] S1. Use a metal containing hydrogen isotopes as a working electrode.

[0027] At present, metals are widely used in many key fields, such as nuclear power plants, natural gas pipelines, power plants, new energy vehicles, ships, etc. In these fields, metals are exposed to the ocean, air, and nuclear radiation, which causes hydrogen isotopes to enter the metals, thus causing the performance of the metals to deteriorate.

[0028] Specifically, the metal includes one or more of iron, steel, stainless steel, nickel, cobalt, aluminum, magnesium, zirconium, tungsten, titanium, molybdenum, tantalum, niobium, rare earth metals or their alloys. The alloy includes iron alloy, nickel alloy, cobalt alloy, aluminum alloy, magnesium alloy, zirconium alloy, tungsten alloy, titanium alloy, molybdenum alloy, tantalum alloy, niobium alloy, rare earth alloy. The above metals are used because they are widely used in the field of hydrogen energy or nuclear energy.

[0029] S2. The working electrode and the counter electrode are arranged in the electrolyte, and a voltage is applied between the counter electrode and the working electrode to promote the oxidation reaction of the hydrogen isotopes in the metal and diffuse them to the metal surface to recover the hydrogen isotopes.

[0030] The present invention applies a voltage between a working electrode and a counter electrode to cause an oxidation reaction of hydrogen isotopes on the metal surface and inside, thereby causing the hydrogen isotopes in the metal to diffuse to the metal surface. The method of the present invention can recover hydrogen isotopes without using a catalyst, because the various parameters of the applied voltage, electrolyte, and counter electrode are controlled to achieve the desired effect of recovering hydrogen isotopes. Here, the present invention preferably does not use a catalyst, which can save costs and is simple to operate. Of course, a catalyst such as platinum can also be used.

[0031] Here, the ability to recover hydrogen isotopes is controlled by the applied voltage, and the applied voltage is 0.3 to 10 V. For example, the voltage is 2V, 4V, 6V, or 8V.

[0032] In one embodiment, the oxidation reaction occurs at normal pressure. In addition, the temperature of the present invention can be at room temperature or slightly above room temperature (e.g., 30° C.) for the oxidation reaction. Here, the present invention can be used to recover hydrogen isotopes, or to reduce or repair hydrogen-induced damage to metals.

[0033] In one embodiment, the hydrogen isotope is one of protium, deuterium and tritium. The preparation process of tritium is very complicated and difficult, which leads to the high price of tritium. The present invention can not only reduce the cost but also improve the resource utilization efficiency by efficiently recovering tritium.

[0034] Specifically, the electrolyte includes a liquid electrolyte, a solid electrolyte or a gel electrolyte. Here, the liquid electrolyte includes an aqueous electrolyte or an oily electrolyte. The liquid electrolyte is an acidic electrolyte, an alkaline electrolyte or a neutral electrolyte. The acidic electrolyte includes a sulfuric acid solution or a polymer electrolyte. The alkaline solution includes a sodium hydroxide solution or a polymer electrolyte. The neutral solution includes a sodium chloride solution or a polymer electrolyte. The solid electrolyte is Nafion. The gel electrolyte is PVA / KOH. Here, the liquid electrolyte can be applied to scenarios where hydrogen embrittlement problems occur in liquid environments, such as nuclear power plants, pipelines in oil and gas exploration, etc. The solid electrolyte can be applied to various metal parts exposed to hydrogen isotope environments. The gel electrolyte is located between the solid phase and the liquid phase, has good flexibility, and can fit metals of different shapes. Here, the shape can include regular shapes and irregular shapes.

[0035] In the present invention, the oxidation reaction occurs at normal pressure. In addition, the temperature of the present invention can be at room temperature or slightly above room temperature (for example, 30° C.) for the oxidation reaction. Here, the present invention can be used to recover hydrogen isotopes, or to reduce or repair hydrogen-induced damage to metals.

[0036] Specifically, the hydrogen isotope is one of protium, deuterium and tritium. The preparation process of tritium is very complicated and difficult, which leads to the high price of tritium. The present invention not only reduces the cost but also improves the resource utilization efficiency by efficiently recovering tritium.

[0037] In the present invention, recovering hydrogen isotopes includes: hydrogen isotopes are present in liquid electrolyte, solid electrolyte or gel electrolyte or escape in other forms. Here, hydrogen isotopes are present in liquid electrolyte, solid electrolyte or gel electrolyte, and the method of recovering them into gaseous state again includes: any one of distillation method, membrane distillation method, thermal diffusion method, membrane permeation method, porous material adsorption method, dual temperature exchange method, gas phase catalytic exchange method, liquid phase catalytic exchange method, ion exchange method, combined electrolytic catalytic exchange method, electrolysis method and laser method.

[0038] Specifically, the material of the counter electrode includes one or more of platinum, palladium, nickel, titanium, molybdenum, silver or their alloys, carbon materials or their composite materials. For example, the carbon material may be attached with at least one of platinum, palladium, nickel, titanium, molybdenum and silver. The alloy includes platinum alloy, palladium alloy, nickel alloy, titanium alloy, molybdenum alloy and silver alloy.

[0039] The voltage value applied by the present invention depends on one or more factors such as the working electrode, the counter electrode, and the electrolyte. For example, the present invention can adopt a two-electrode system or a three-electrode system (adding a reference electrode). Here, the applied voltage can vary depending on the electrolyte used. For example, for solid, stable or non-corrosive electrolytes, the applied potential range can be very high, such as about 0.6 to +10V or higher.

[0040] For example, when using an aqueous electrolyte or a corrosive or unstable electrolyte, the applied voltage can be kept below the voltage of the electrolysis of water, so that hydrogen isotopes (such as deuterium tritium) can be recovered from the metal while avoiding the electrolysis of water to affect the recovery of deuterium or tritium. It should be understood that the value of the electrolysis potential of water can vary according to one or more of the metal, the type of electrolyte used, etc.

[0041] The present invention provides an electrically driven system for recovering hydrogen isotopes in metals, comprising: a metal containing hydrogen isotopes, a counter electrode and an electrolyte. The metal containing hydrogen isotopes and the counter electrode are arranged in the electrolyte, and a voltage is applied between the counter electrode and the working electrode to promote an oxidation reaction of the hydrogen isotopes in the metal and diffuse them to the metal surface, so as to recover the hydrogen isotopes.

[0042] Specifically, the applied voltage is 0.3 to 10V.

[0043] Specifically, the electrolyte includes a liquid electrolyte, a solid electrolyte or a gel electrolyte. Here, the liquid electrolyte includes an aqueous electrolyte or an oily electrolyte. The liquid electrolyte is an acidic electrolyte, an alkaline electrolyte or a neutral electrolyte. The acidic electrolyte includes a sulfuric acid solution or a polymer electrolyte. The alkaline solution includes a sodium hydroxide solution or a polymer electrolyte. The neutral solution includes a sodium chloride solution or a polymer electrolyte. The solid electrolyte is Nafion. The gel electrolyte is PVA / KOH.

[0044] Specifically, the metal includes one or more of iron, steel, stainless steel, nickel, cobalt, aluminum, magnesium, zirconium, tungsten, titanium, molybdenum, tantalum, niobium, rare earth metals or alloys thereof.

[0045] Specifically, the material of the counter electrode includes one or more of platinum, palladium, nickel, titanium, molybdenum, silver or their alloys, carbon materials or their composite materials.

[0046] The system of the present invention applies a voltage between the working electrode and the counter electrode to cause an oxidation reaction of hydrogen isotopes on the metal surface and inside, thereby causing the hydrogen isotopes in the metal to diffuse to the metal surface. For example, the hydrogen on the metal surface and inside is mainly mobile hydrogen isotopes, hydrogen isotopes with low adsorption energy, and hydrogen isotopes with strong adsorption energy. In addition to recovering mobile hydrogen isotopes and hydrogen isotopes with low adsorption energy in the metal substrate, the method of the present invention can also recover hydrogen isotopes with strong adsorption energy. The method of the present invention can recover hydrogen isotopes without the use of a catalyst, because the ideal effect of recovering hydrogen isotopes is achieved by controlling the applied voltage, electrolyte, and various parameters of the counter electrode.

[0047] In order to better understand the present invention, the content of the present invention is further explained below with reference to the accompanying drawings and examples, but the content of the present invention is not limited to the following embodiments.

[0048] Example 1

[0049] The experimental design principle is: by charging the metal substrate with deuterium at room temperature or higher temperature, and then using the deuterium-charged metal substrate as the working electrode, combined with the reference electrode and the counter electrode to form a three-electrode system, the deuterium in the metal substrate is removed by electrochemical method in the electrolyte. The amount of deuterium removed is regulated by optimizing the process.

[0050] This embodiment provides a method for electrically driving the recovery of hydrogen isotopes in metals, comprising the following steps:

[0051] Step 1: Three pure iron substrates were charged with deuterium at 100°C and then cooled to room temperature. They were taken out and left for 30 minutes. The first substrate was then deuterated by a high-temperature desorption process to determine the amount of deuterium introduced and information related to the adsorption amount.

[0052] Step 2: For the second pure iron substrate charged with deuterium, the deuterium removal conditions are: 0.4V, 0.1M KOH aqueous solution as electrolyte, and reaction time of 4h; then the deuterium is removed by high temperature desorption process to determine the amount of remaining deuterium and related information of adsorption amount (such as Figure 1 shown).

[0053] Step 3: For the third deuterium-charged pure iron substrate, the deuterium removal conditions are: 0.6V, reaction time 4h, and then the deuterium is removed by high temperature desorption process to determine the amount of remaining deuterium and related information of adsorption amount (such as Figure 1 shown).

[0054] Example 2

[0055] The experimental design principle is: by charging the metal substrate with deuterium at room temperature or higher temperature, then using the deuterium-charged metal substrate as the working electrode and combining it with the counter electrode to form a three-electrode system, the deuterium in the metal substrate is removed by electrochemical method in the electrolyte. The amount of deuterium removed is regulated by optimizing the process.

[0056] This embodiment provides a method for electrically driving the recovery of hydrogen isotopes in metals, comprising the following steps:

[0057] Step 1: Two stainless steel substrates (X80) are charged with deuterium at room temperature and then cooled to room temperature. After being taken out and left for a period of time, one of the substrates is subjected to a high-temperature desorption process to remove deuterium to determine the amount of deuterium introduced and information related to the adsorption amount.

[0058] Step 2: For another stainless steel substrate (X80) charged with deuterium, the deuterium removal conditions are: 0.6V, 0.1M KOH aqueous solution as electrolyte, reaction time 4h, and then the deuterium is removed by high temperature desorption process to determine the amount of remaining deuterium and related information of adsorption amount (such as Figure 2 shown).

[0059] Example 3

[0060] The design principle of this experiment is: by charging the metal substrate with deuterium at room temperature or higher temperature, and then using the deuterium-charged metal substrate as the working electrode and the other electrode as the reference electrode and the counter electrode, the deuterium in the metal substrate is removed in the electrolyte, and the amount of deuterium removed is controlled by optimizing the process.

[0061] This embodiment provides a method for electrically driving the recovery of hydrogen isotopes in metals, such as Figure 3 As shown, the following steps are included:

[0062] Step 1: Two pure iron substrates are charged with deuterium at 100°C and then cooled to room temperature. They are taken out and left for 30 minutes. Then one of them is deuterated by a high-temperature desorption process to determine the amount of deuterium introduced and information related to the adsorption amount.

[0063] Step 2: For another pure iron substrate charged with deuterium, the deuterium removal conditions are: 0.6V, 0.1M KOH aqueous solution as electrolyte, deuterium removal time 4h, and then the deuterium is removed by high temperature desorption process to determine the amount of remaining deuterium and related information of adsorption amount (such as Figure 4 shown).

[0064] Test results:

[0065] (1) The high temperature thermal desorption spectrum of the above-mentioned pure iron substrate after deuterium charging shows that there are peaks of deuterium desorption at around 280°C, 310°C and 500°C;

[0066] (2) The high temperature thermal desorption spectrum of the above-mentioned pure iron substrate after deuterium charging and voltage difference deuterium removal treatment shows that the area of ​​the deuterium desorption peak has decreased, and the corresponding highest peak position has also changed, indicating that the remaining deuterium has decreased. Referring to the literature, based on the corresponding area of ​​the spectrum, it can be estimated that the deuterium removal rate in the pure iron substrate after deuterium charging is 90%.

[0067] Example 1 uses a three-electrode electrochemical method to confirm the feasibility of removing high adsorption energy hydrogen isotopes in metal substrates in principle, and proves that Pd metal catalysts are not required. For the dehydrogenation needs of specific application scenarios, dehydrogenation devices and processes can be designed based on this principle.

[0068] The present invention can also use a two-electrode method to remove hydrogen isotopes with high adsorption energy in metal substrates under room temperature conditions. The existing examples use liquid electrolytes, and in actual applications, liquid electrolytes, solid electrolytes or gel electrolytes can be used; and the voltage is applied in a two-electrode manner, which means that it can be simplified to a DC voltage method. (1) The reference electrode can be omitted and only two electrodes can be used, that is, the power source can no longer be a relatively expensive electrochemical workstation and its control software, but a relatively low-priced and simple-to-control DC power supply; (2) For large or irregular shapes, the conventional three-electrode method is inconvenient to use, and the two-electrode method can be easier to implement.

[0069] The embodiments described above are part of the embodiments of the present invention, rather than all of the embodiments. The detailed description of the embodiments of the present invention is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention, and the protective measures required for the experiments should comply with relevant environmental protection and safety requirements. Based on the embodiments of the present invention and the protective measures required for the corresponding experiments, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Claims

1. A method for electrically driving the recovery of hydrogen isotopes in metals, characterized in that: The method comprises: A metal containing hydrogen isotopes is used as a working electrode; The working electrode and the counter electrode are arranged in the electrolyte, and a voltage is applied between the counter electrode and the working electrode to promote the oxidation reaction of hydrogen isotopes in the metal and diffuse them to the metal surface to recover the hydrogen isotopes.

2. The method according to claim 1, characterized in that The oxidation reaction takes place at normal pressure.

3. The method according to claim 1, characterized in that The electrolyte includes a liquid electrolyte, a solid electrolyte or a gel electrolyte.

4. The method according to claim 3, characterized in that The recovering of hydrogen isotopes includes: the hydrogen isotopes are present in a liquid electrolyte, a solid electrolyte or a gel electrolyte or escape in other forms.

5. The method according to claim 1, characterized in that The metal includes one or more of iron, steel, stainless steel, nickel, cobalt, aluminum, magnesium, zirconium, tungsten, titanium, molybdenum, tantalum, niobium, rare earth metals or alloys thereof.

6. The method according to claim 1, characterized in that The material of the counter electrode includes one or more of platinum, palladium, nickel, titanium, molybdenum, silver or alloys thereof, carbon materials or composite materials thereof.

7. The method according to claim 1, characterized in that The hydrogen isotope is one of protium, deuterium and tritium.

8. An electrically driven system for recovering hydrogen isotopes from metals, characterized in that: include: a metal containing a hydrogen isotope, a counter electrode, and an electrolyte; A metal containing hydrogen isotopes and a counter electrode are placed in an electrolyte, and a voltage is applied between the counter electrode and the working electrode to induce an oxidation reaction of the hydrogen isotopes in the metal and diffuse them to the metal surface to recover the hydrogen isotopes.

9. The system according to claim 8, characterized in that The electrolyte includes a liquid electrolyte, a solid electrolyte or a gel electrolyte.

10. The system according to claim 8, characterized in that The metal includes one or more of iron, steel, stainless steel, nickel, cobalt, aluminum, magnesium, zirconium, tungsten, titanium, molybdenum, tantalum, niobium, rare earth metals or alloys thereof.

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