Method for preparing double high-purity gas by electrically driving separation of hydrogen-helium mixed gas

Abstract

This invention belongs to the field of hydrogen-helium gas separation and purification technology, and relates to an electrically driven method for separating hydrogen-helium mixed gases to prepare dual high-purity gases. Its key feature is the use of electrical energy as the driving force, establishing a stable control system for a single-stage electrochemical hydrogen pump and a stoichiometric limit operation method. Hydrogen gas is electrochemically dissociated at atmospheric pressure into protons that conduct across the membrane, then recombine to form hydrogen gas for desorption. Helium, being highly inert, cannot dissociate, thus achieving highly selective separation of the hydrogen-helium mixed gas. This method can simultaneously produce high-purity helium (purity greater than 99.999%) and fuel cell-grade pure hydrogen (purity greater than 99.97%). Compared with the traditional catalytic oxidation dehydrogenation method for producing high-purity helium, this method avoids the waste of large amounts of hydrogen resources through combustion and is safer and more efficient, providing a new approach to solving the technical challenges of hydrogen-helium separation.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of hydrogen-helium gas separation and purification, and relates to a method for preparing double high-purity gas by electrically driving separation of hydrogen-helium mixed gas. The method uses electric energy as driving force and utilizes an electrochemical hydrogen pump to electrochemically dissociate hydrogen gas into protons at normal pressure, conduct the protons across a membrane, and then recombine the protons into hydrogen gas for desorption, while helium gas is inert and cannot be dissociated, so that the hydrogen-helium mixed gas is separated with high selectivity to prepare high-purity helium gas (purity greater than 99.999%) and high-purity hydrogen gas for fuel cells (99.97%). Compared with the traditional catalytic oxidation dehydrogenation method for high-purity helium gas, the method avoids the waste of a large amount of hydrogen gas resources by combustion, is safer and more efficient, and provides a new idea for solving the technical problem of hydrogen-helium separation. BACKGROUND

[0002] Helium is a colorless, odorless rare gas with very inert chemical properties and is the gas with the smallest density except hydrogen. The boiling point of helium is -269℃, making it the most difficult gas to liquefy, and it is also the only substance that cannot be solidified at standard atmospheric pressure. The unique physicochemical properties make helium widely used in aerospace, military defense, medical care and electronic communication, and it has become an important strategic resource indispensable for maintaining national security and the development of high-tech industries.

[0003] The preparation methods of helium include natural gas separation method, synthetic ammonia tail gas extraction method, air fractionation method and uranium ore extraction method. So far, the only industrial source of helium production worldwide is helium-containing natural gas. The composition of helium-containing natural gas is relatively complex, as shown in Table 1 for the composition of helium-containing natural gas in a certain factory. At present, the commonly used industrial cryogenic helium extraction process generally consists of a pretreatment process (CO2, H2O removal), a crude helium extraction process (helium content 60%-70%) and a crude helium refining process. Among them, impurities such as hydrogen sulfide, carbon dioxide and water can be removed by traditional acid gas removal or dehydration methods, and argon, oxygen and nitrogen can be removed by adsorption methods. Since the molecular diameter of hydrogen is 0.289 nm and the liquefaction temperature is -252.87℃, while the molecular diameter of helium is 0.26 nm and the liquefaction temperature is -268.93℃, i.e. the physicochemical properties of the two are extremely similar and the liquefaction temperature is close to absolute zero, the separation selectivity of absorption or gas membrane separation technology driven by concentration difference is extremely low, and the energy consumption of thermal-driven low-temperature rectification technology increases sharply, which seriously limits the hydrogen-helium separation purity. Therefore, the biggest technical problem for natural gas helium extraction process is hydrogen-helium separation.

[0004] Table 1 Composition of helium-containing natural gas raw material gas

[0005]

[0006]

[0007] The commonly used method for hydrogen-helium separation is catalytic oxidation dehydrogenation, which involves introducing air before the crude helium refining process and oxidizing the H2 in it to H2O under the action of a catalyst, thereby avoiding direct hydrogen-helium separation. This separation method not only introduces a large number of new impurities, but also significantly increases the amount of raw gas that can be processed, resulting in a substantial increase in operating costs and energy consumption. At the same time, it also leads to a waste of hydrogen resources.

[0008] Electrochemical hydrogen pumps (EHP) are electrically driven and can selectively produce high-purity hydrogen. (See attached image.) Figure 2 As shown, hydrogen enters the anode channel of the hydrogen pump through the EHP anode inlet. The hydrogen passes through the gas diffusion layer (GDL) and enters the catalyst layer (CL) where it undergoes an oxidation reaction with the Pt catalyst, losing electrons to become hydrogen protons. These protons, under an applied voltage, are conducted across the proton exchange membrane (PEM) to the cathode, while electrons travel along the external circuit from the anode to the cathode. The hydrogen protons and electrons then undergo a reduction reaction in the cathode catalyst layer, releasing hydrogen gas. Other gaseous components, such as nitrogen and helium, have high electrochemical inertness and do not undergo electrochemical reactions to pass across the proton exchange membrane, exiting directly from the anode outlet. Theoretically, the electrochemical hydrogen pump has infinite selectivity for hydrogen and can operate at atmospheric pressure within a range of room temperature to 80°C, achieving highly selective hydrogen separation of hydrogen-containing mixtures. Under an applied voltage, the oxidation and reduction reactions of hydrogen occur very readily, requiring very low energy consumption for the electrode reactions. The hydrogen production rate of the electrochemical hydrogen pump is equivalent to the current density, conforming to Faraday's law. The purity of the prepared cathode hydrogen depends on operating conditions, such as applied voltage, membrane water content and permeability, inlet gas purity, and device operational stability.

[0009] The anode electrode reaction is shown in equation (1.1):

[0010] H2→2H + +2e - (1.1)

[0011] The cathode electrode reaction is shown in equation (1.2):

[0012] 2H + +2e - →H2(1.2)

[0013] The overall reaction equation is shown in equation (1.3):

[0014] H2 (anode) → H2 (cathode) (1.3)

[0015] Current research on electrochemical hydrogen pumps focuses on efficient hydrogen separation. Nordio et al. (Chemical Engineering Journal, 2019, 369: 432-442) prepared hydrogen from a hydrogen-helium mixture. Gas chromatography showed that the hydrogen purity at the cathode was only about 98%. This study was not conducted under stoichiometric current-limited conditions. Although the purity of helium at the anode was not measured in the paper, it is theoretically inferred that the helium purity was extremely low. Cheng et al. (Journal of Tsinghua University (Natural Science Edition), 2023, 63(05): 704-713) simulated the separation of hydrogen-helium mixtures using a two-stage electrochemical hydrogen pump. The hydrogen removal rate after the first-stage electrochemical hydrogen pump was less than 70%, and the helium purity after the second-stage electrochemical hydrogen pump was only 99.9%, which did not meet the national standard for pure helium and was not verified by actual measurement. Onda et al. (Journal of Power) (Sources, 2019, 188: 1–7) tested the residual hydrogen content at the anode of H2 / N2 / CO2 systems with hydrogen contents ranging from 1% to 99% after treatment with an electrochemical hydrogen pump, but did not adjust the hydrogen purity at the cathode. In summary, no research reports have been found on the preparation of two high-purity gases from a two-component hydrogen-containing mixture using an electrochemical hydrogen pump. Summary of the Invention

[0016] This invention provides a method for preparing two high-purity gases by electrically driven separation of a hydrogen-helium mixture. The method establishes a stable control system for a single-stage electrochemical hydrogen pump and a stoichiometric limit operation method to separate hydrogen-helium mixtures of different concentrations into high-purity helium (purity greater than 99.999%) and fuel cell-grade hydrogen (purity greater than 99.97%). This achieves stable operation of the electrochemical hydrogen pump in preparing two high-purity gases and dynamic monitoring of the product chromatography. Compared with the traditional catalytic oxidation dehydrogenation method, this method avoids the waste of a large amount of hydrogen resources through combustion and is safer and more efficient. It is of great significance for solving the technical challenges of hydrogen-helium separation, the industrial application of electrochemical hydrogen pumps, and addressing the bottleneck problem of helium supply shortage in my country.

[0017] The technical solution of the present invention is as follows:

[0018] A method for preparing two high-purity gases by electrically driven separation of a hydrogen-helium mixture is disclosed. The method is characterized by: using electrical energy as the driving force, establishing a stable control system for a single-stage electrochemical hydrogen pump and a stoichiometric limit operation method; electrochemically dissociating hydrogen at ambient pressure into protons that conduct across the membrane, then recombine to form hydrogen gas for desorption; and conversely, helium, being highly inert, cannot be freely adsorbed or dissociated, thus achieving highly selective separation of the hydrogen-helium mixture and simultaneously preparing two high-purity gases. A product dynamic monitoring system is configured to continuously monitor the purity of the helium and hydrogen products.

[0019] The aforementioned stable control system for a single-stage electrochemical hydrogen pump refers to a system added to a traditional electrochemical hydrogen pump device. This system maintains stable parameters within the device, ensuring stable operation and significantly reducing current fluctuations over time (controlled within 3%), playing a crucial role in the preparation of high-purity gases. For example... Figure 1 As shown, the stable control system includes an electrochemical hydrogen pump, a humidification tank and a thermostat for its connecting pipelines, as well as a cathode outlet check valve, an anode outlet check valve, and a cathode outlet three-way valve. The humidification tank is located between the hydrogen-helium mixed gas source and the anode inlet of the electrochemical hydrogen pump. The thermostat maintains synchronous and stable temperature and humidity. The cathode outlet check valve and anode outlet check valve are located at the outlets of the cathode and anode, respectively, ensuring the airtightness of the device, maintaining constant outlet pressure, and avoiding interference from pressure fluctuations caused by feeding and dynamic monitoring. The cathode outlet three-way valve is located between the cathode outlet check valve and the cathode outlet, enabling arbitrary switching between three operating conditions: single-port outlet, dual-port outlet, and cathode purging gas application, ensuring stable operation of the device under different conditions.

[0020] The stoichiometric limit operation method for the single-stage electrochemical hydrogen pump refers to the long-term stable operation of the electrochemical hydrogen pump under stoichiometric limit current conditions by adjusting the voltage (range 0.1-1.0V) for hydrogen-helium mixtures with different feed flow rates and compositions. This is a key operation method for preparing high-purity helium, enabling complete electrochemical dissociation of hydrogen at the anode into protons that conduct across the membrane to the cathode for desorption. The stoichiometric limit current and hydrogen flow rate obey Faraday's law, i.e. Where n represents the number of moles of hydrogen gas at the inlet (mol), t represents time (s), I represents the current (A), and F = 96485 C / mol, Faraday constant;

[0021] The product chromatographic dynamic monitoring system refers to a continuous injection system using a chromatography system with a helium ionization detector. The design of the six-way valve is improved, and the injection port and the vent port are always connected during the test. Bubblers and drying tubes are respectively installed after the cathode outlet check valve and the anode outlet check valve to maintain unidirectional gas flow and buffer flow fluctuations. This ensures that the outlet gas of the cathode and anode has very small pressure changes during long-term chromatographic testing, and the pressure fluctuation time is controlled within 2 seconds, thereby enabling long-term continuous product dynamic monitoring.

[0022] Furthermore, the different feed flow rates and compositions of the hydrogen-helium mixed gas refer to the ratio of hydrogen flow rate to membrane area in the mixed gas not exceeding 15, and the hydrogen gas integral number being 10%-90%.

[0023] Furthermore, the aforementioned dual high-purity gases refer to high-purity helium and high-purity hydrogen, wherein the helium purity is greater than 99.999% (volume fraction) and is detected using a helium ionization gas chromatograph such as Shimadzu GC-2030; and the hydrogen purity is greater than 99.97% (volume fraction) and is detected using a Shimadzu GC-2014.

[0024] Furthermore, the statement that electrical energy is the driving force refers to applying an external voltage to the electrochemical hydrogen pump to operate in a constant voltage mode.

[0025] Furthermore, the aforementioned electrochemical hydrogen pump refers to the assembly of an anode, a proton exchange membrane, and a cathode sequentially between two graphite plates engraved with serpentine flow channels; wherein the anode and cathode are coated on carbon paper with a loading of 0.5 mg / cm³. 2 Gas diffusion electrode for Pt catalyst; proton exchange membrane refers to Nafion 212 membrane;

[0026] Furthermore, the parameters within the electrochemical hydrogen pump device include gas flow rate, pressure, temperature, and humidity. The parameter settings are as follows: gas flow rate is 1-100 SCCM, pressure is atmospheric pressure 0.1 MPa, temperature is 30-60℃, and relative humidity is 70-100%.

[0027] Furthermore, the source of the hydrogen-helium mixed gas refers to the hydrogen-helium gas mixture, which may originate from gas cylinders provided by professional gas manufacturers, or from helium-containing natural gas that has undergone a pretreatment process to remove other impurities. The content of other impurities in the hydrogen-helium gas mixture is less than 10 ppm.

[0028] The beneficial effects of this invention are as follows: This invention innovatively proposes an electrochemical separation method to achieve low-energy and high-efficiency separation of hydrogen-helium mixed gases, simultaneously obtaining high-purity helium and fuel cell-grade pure hydrogen. Its core components, the proton exchange membrane and gas diffusion electrode, have mature commercial production technologies, facilitating the scale-up and promotion of electrochemical hydrogen pump devices, meeting industrial requirements, and possessing significant economic and social value. It is of paramount research importance for solving the "bottleneck" problem of my country's reliance on imports for over 95% of its helium. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the process flow of the present invention.

[0030] 1. Gas source; 2. Mass flow meter; 3. Humidifier; 4. Thermostat; 5. Electrochemical hydrogen pump; 6. Anode outlet check valve; 7. Cathode outlet three-way valve; 8. Cathode outlet check valve; 9. Anode bubbler; 10. Anode drying tube; 11. Cathode bubbler; 12. Cathode drying tube; 13. Gas chromatograph.

[0031] Figure 2 This is a schematic diagram of the separation principle of an electrochemical hydrogen pump.

[0032] Figure 3 The operational stability curves of current versus time before and after the installation of the stability control system were compared. Among them, (a) is the current fluctuation curve of the installation of the stability control system, where the periodic current fluctuation points are all the injection points of the gas chromatograph, which do not affect the normal operation of the electrochemical hydrogen pump. Ignoring the additional effects of chromatography, the current fluctuation is controlled within 3%. In contrast, the conventional electrochemical hydrogen pump without the installation of the stability control system, as shown in (b), has a large current fluctuation, reaching up to 22%.

[0033] Figure 4 The effective area of ​​the membrane is 1 cm². 2 The total flow rate of the hydrogen-helium mixture was 10 SCCM, the operating temperature of the electrochemical hydrogen pump was 50℃, and the relative humidity was 100%. The energy efficiency-voltage curves of the electrochemical hydrogen pump were analyzed when the hydrogen concentration in the hydrogen-helium mixture was changed. It can be seen that the energy efficiency of the electrochemical hydrogen pump can reach up to 90.9%, indicating its low energy consumption.

[0034] Figure 5 The purity and stability of the anode helium and cathode hydrogen produced by the electrochemical hydrogen pump were tested under the following conditions: hydrogen integral of 30% in the hydrogen-helium mixture, hydrogen flow rate to Nafion 212 membrane area ratio of 1.2, electrochemical hydrogen pump operating temperature of 50℃, and relative humidity of 100%. It can be seen that, under the stoichiometric limiting current, the hydrogen content detected at the anode is less than 0.4 ppm, indicating that the purity of the helium produced at the anode is greater than 99.9999%, reaching the purity of 6N high-purity helium; the helium content detected at the cathode is less than 300 ppm, indicating that the purity of the hydrogen produced at the cathode is greater than 99.97%, meeting the purity requirements for fuel cell-grade hydrogen.

[0035] Example 1

[0036] The single-stage electrochemical hydrogen pump testing system of this invention has a Pt loading of 0.5 mg / cm³ for both the cathode and anode catalysts. 2 Nafion 212 was used as the proton exchange membrane. When the electrochemical hydrogen pump operated at 50°C, the relative humidity of the feed gas was 100%, the total gas flow rate was 100 SCCM, and the pressure was 0.1 MPa (at atmospheric pressure); the hydrogen concentration in the hydrogen-helium mixture was 40%, and the ratio of hydrogen flow rate to membrane area in the mixture was 10, an applied voltage of 0.3V ensured that the stoichiometric limit current was reached. Helium purity was tested using a Shimadzu GC-2030; hydrogen purity was tested using a Shimadzu GC-2014. At this point, the hydrogen concentration detected at the anode was less than 2 ppm, meaning the anode could obtain 99.9998% high-purity helium; the He concentration tested at the cathode was less than 0.4 ppm, meaning the hydrogen concentration was greater than 99.97%, meeting the national standard for fuel cell-grade hydrogen, GB / T 37244-2018.

[0037] Example 2

[0038] The single-stage electrochemical hydrogen pump testing system of this invention has a Pt loading of 0.5 mg / cm³ for both the cathode and anode catalysts. 2 Nafion 212 was used as the proton exchange membrane. When the electrochemical hydrogen pump operated at 30°C, the feed gas relative humidity was 100%, the total gas flow rate was 10 SCCM, and the pressure was 0.1 MPa (at atmospheric pressure); the hydrogen concentration in the hydrogen-helium mixture was 30%, and the hydrogen flow rate to membrane area ratio was 3, an applied voltage of 0.4V ensured that the stoichiometric limit current was reached. Helium purity was measured using a Shimadzu GC-2030; hydrogen purity was measured using a Shimadzu GC-2014. At this point, the hydrogen concentration detected at the anode was approximately 0.712 ppm, meaning the anode could obtain 6N high-purity helium with a purity greater than 99.9999%; simultaneously, the helium concentration detected at the cathode was less than 280 ppm, meaning the hydrogen concentration was greater than 99.97%, meeting the national standard for fuel cell-grade hydrogen.

[0039] Example 3

[0040] The single-stage electrochemical hydrogen pump testing system of this invention has a Pt loading of 0.5 mg / cm³ for both the cathode and anode catalysts. 2 Nafion 212 was used as the proton exchange membrane. When the electrochemical hydrogen pump operated at 50°C, the feed gas relative humidity was 77%, the total gas flow rate was 50 SCCM, and the pressure was 0.1 MPa (at atmospheric pressure); the hydrogen concentration in the hydrogen-helium mixture was 20%, and the hydrogen flow rate to membrane area ratio was 5, an applied voltage of 0.5V ensured that the stoichiometric current was reached. Helium purity was tested using a Shimadzu GC-2030; hydrogen purity was tested using a Shimadzu GC-2014. At this point, the detected anode hydrogen concentration was 1.077 ppm, yielding 99.9998% high-purity helium; simultaneously, the cathode helium concentration was less than 200 ppm, meaning the hydrogen concentration was above 99.97%, meeting the national standard for fuel cell-grade hydrogen.

[0041] Example 4

[0042] The single-stage electrochemical hydrogen pump testing system of this invention has a Pt loading of 0.5 mg / cm³ for both the cathode and anode catalysts. 2Nafion 212 was used as the proton exchange membrane. When the electrochemical hydrogen pump operated at 50°C, the feed gas relative humidity was 100%, the total gas flow rate was 20 SCCM, and the pressure was 0.1 MPa (at atmospheric pressure); the hydrogen concentration in the hydrogen-helium mixture was 70%, and the hydrogen flow rate to membrane area ratio was 8, an applied voltage of 0.6V ensured that the stoichiometric limit current was reached. Helium purity was measured using a Shimadzu GC-2030; hydrogen purity was measured using a Shimadzu GC-2014. At this point, the hydrogen concentration in the anode outlet product was less than 1.071 ppm, yielding 99.9998% high-purity helium. Simultaneously, the helium concentration in the cathode outlet product remained stable below 250 ppm, meaning the hydrogen concentration remained above 99.97%, meeting the national standard for fuel cell-grade hydrogen.

[0043] The above description is merely a specific implementation example of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing two high-purity gases by electrically driven separation of a hydrogen-helium mixture, characterized in that, Driven by electrical energy, a stable control system and stoichiometric limit operation method for a single-stage electrochemical hydrogen pump are established. Hydrogen gas is electrochemically dissociated into protons transmembrane conduction at atmospheric pressure, and then recombines to form hydrogen gas for desorption. Helium gas, being highly inert, cannot be freely adsorbed or dissociated, thus achieving highly selective separation of hydrogen-helium mixed gases and simultaneously preparing two high-purity gases. A chromatographic dynamic monitoring system is configured to dynamically and continuously monitor the purity of the helium and hydrogen products. The aforementioned stable control system for the single-stage electrochemical hydrogen pump refers to adding a stable control system to the electrochemical hydrogen pump device to maintain the stability of various parameters within the device, ensuring stable operation and reducing current fluctuations over time. The stable control system includes the electrochemical hydrogen pump, a humidification tank, and a thermostatic device for their connecting pipelines, as well as a cathode outlet check valve, an anode outlet check valve, and a cathode outlet three-way valve. The humidification tank is located between the hydrogen-helium mixed gas source and the anode inlet of the electrochemical hydrogen pump. The thermostatic device maintains synchronous and stable temperature and humidity. The cathode outlet check valve and anode outlet check valve are respectively located at the outlet sides of the cathode and anode, ensuring the airtightness of the device, maintaining constant outlet pressure, and avoiding interference from pressure difference fluctuations caused by feeding and dynamic monitoring. The cathode outlet three-way valve is located between the cathode outlet check valve and the cathode outlet, connecting to one of the cathode outlets, the hydrogen-helium mixed gas source outlet, and the cathode outlet check valve, enabling arbitrary switching between three operating conditions: single-port outlet, dual-port outlet, and cathode purging gas application, ensuring stable operation of the device under different conditions. The stoichiometric limit operation method for the single-stage electrochemical hydrogen pump refers to the long-term stable operation of the electrochemical hydrogen pump under stoichiometric limit current conditions by adjusting the voltage (range 0.1-1.0 V) for hydrogen-helium mixtures with different feed flow rates and compositions. This is a key operation method for preparing high-purity helium, enabling complete electrochemical dissociation of hydrogen at the anode into protons that conduct across the membrane to the cathode for desorption. The stoichiometric limit current and hydrogen flow rate obey Faraday's law, i.e. , where n represents the number of moles of hydrogen gas at the inlet (mol), t represents time (s), I represents the current (A), F=96485C / mol, and F represents the Faraday constant; The aforementioned chromatographic dynamic monitoring system refers to a continuous injection system using a chromatography system equipped with a helium ionization detector. A bubbler and a drying tube are respectively installed after the cathode outlet check valve and the anode outlet check valve. By utilizing the buffering effect of the drying tube and the bubbler, as well as the unidirectional flow characteristic of the check valve, it is ensured that the outlet gas of the cathode and anode undergoes very small pressure changes during long-term chromatographic testing, with pressure fluctuations lasting only within 2 seconds, thereby achieving long-term continuous dynamic monitoring of the product.

2. The method for preparing dual high-purity gases by electrically driven separation of hydrogen-helium mixed gas according to claim 1, characterized in that, The different feed flow rates and compositions of the hydrogen-helium mixed gas refer to hydrogen flow rates to membrane areas that do not exceed 15 and hydrogen integrals that are 10%-90%.

3. The method for preparing dual high-purity gases by electrically driven separation of hydrogen-helium mixed gas according to claim 1, characterized in that, The aforementioned dual high-purity gases refer to high-purity helium and high-purity hydrogen, wherein the purity of the anode helium reaches 99.999%-99.9999% by volume, and the purity of the cathode hydrogen is greater than 99.97% by volume, meeting the hydrogen purity requirements for fuel cell grade.

4. The method for preparing dual high-purity gases by electrically driven separation of hydrogen-helium mixed gas according to claim 1, characterized in that, The electrochemical hydrogen pump consists of an anode, a proton exchange membrane, and a cathode sequentially assembled between two graphite plates etched with serpentine flow channels; wherein the anode and cathode are coated on carbon paper with a loading of 0.5 mg / cm³. 2 The gas diffusion electrode of the Pt catalyst; the proton exchange membrane refers to the Nafion 212 membrane; it operates in constant voltage mode under applied voltage.

5. The method for preparing dual high-purity gases by electrically driven separation of hydrogen-helium mixed gas according to claim 1, characterized in that, In the stable control system of the single-stage electrochemical hydrogen pump, the purity of helium is determined by gas chromatography equipped with a helium ionization detector.

6. The method for preparing dual high-purity gases by electrically driven separation of hydrogen-helium mixed gas according to claim 1, characterized in that, The parameters of the electrochemical hydrogen pump device include gas flow rate, pressure, temperature and humidity. The parameter settings are as follows: gas flow rate is 1-100 SCCM, pressure is 0.1 MPa, temperature is 30-60 ℃, and relative humidity is 70%-100%.

7. The method for preparing dual high-purity gases by electrically driven separation of hydrogen-helium mixed gas according to claim 1, characterized in that, The source of the hydrogen-helium mixed gas is a gas cylinder provided by a gas manufacturer, or helium-containing natural gas that has undergone a pretreatment process to remove other impurities. The content of other impurities in the hydrogen-helium gas mixture is less than 10 ppm.

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