A purification device for preparing high-purity deuterium gas by electrolysis of heavy water

Abstract

The present application belongs to the field of gas purification, and particularly relates to a kind of purification field of high-purity and ultrahigh-purity deuterium gas prepared by electrolysis of heavy water, deuterium gas coming out of electrolysis device as raw gas enters adsorption column filled with molecular sieve for preliminary purification and drying, reducing water and part of impurities in deuterium gas, avoiding damage of water in raw gas to palladium membrane in subsequent process, and confirming to reach the requirement of raw gas for palladium membrane purification after detection by dew point instrument;Gas coming out of molecular sieve column enters palladium membrane purification tube after adjusting flow by electromagnetic valve, for ultrapurification of gas.Adsorption column can be switched for use, one column works, and the other column regenerates, without disassembly, can be used continuously, greatly reducing operation time, ensuring stability of purification system, making deuterium gas purification more thorough.Deuterium gas treatment capacity can be between 4L / min and 400L / min, which can be used for high-purity deuterium gas purification of laboratory small deuterium production equipment or small-scale commercial electrolysis of heavy water to produce high-purity deuterium gas.

Description

Technical Field

[0001] This invention relates to the field of gas purification technology, specifically to a purification apparatus for preparing high-purity deuterium gas by electrolysis of heavy water. Background Technology

[0002] Deuterium is a colorless, flammable, and odorless gas. It is considered a strategic new product in the specialty gases industry. Deuterium with a purity of 5N or higher is called high-purity deuterium. High-purity deuterium is primarily used in high-pressure annealing equipment to prevent leakage current caused by tunneling during chip manufacturing. It is also widely used as a heat treatment gas in optical fiber manufacturing for anti-aging annealing, improving resistance to hydrogen aging to enhance the lifespan and brightness of optical cables.

[0003] Currently, deuterium is mainly produced by electrolyzing heavy water. However, in the actual production process, heavy water easily contains small amounts of impurities, resulting in deuterium gas containing impurities such as oxygen, nitrogen, carbon monoxide, carbon dioxide, methane and other hydrocarbons, heavy water, hydrogen deuteride, and hydrogen. Therefore, the deuterium gas obtained from electrolyzing heavy water must be purified by purification equipment to obtain high-purity deuterium gas.

[0004] Molecular sieves exhibit good adsorption properties for gases such as oxygen, nitrogen, carbon monoxide, carbon dioxide, and heavy water. However, when high purity is required for the product gas, this purification method may not be sufficient. Therefore, combining it with palladium membrane purification yields the best results. After adsorption by the molecular sieve, the gas purity can meet the requirements of the raw gas for palladium membrane purification. Palladium membranes have excellent permeability to deuterium and can retain any other gas besides deuterium. Therefore, they can be used in deuterium separation and purification, deuterium production, and deuterium recovery, achieving a product gas purity of 7N or higher. Summary of the Invention

[0005] The purpose of this invention is to provide a purification device for preparing high-purity deuterium gas by electrolysis of heavy water, which helps to reduce the production cost of deuterium gas.

[0006] The technical solution of the present invention is a purification device for preparing high-purity deuterium gas by electrolysis of heavy water, comprising: an explosion-proof cabinet, a purification column, a heating system, a dew point meter, a deuterium gas alarm, a solenoid valve, a stainless steel valve, a gas flow meter, a pressure sensor, a palladium membrane purification tube, a vacuum pump, a power supply and control box, and a control panel.

[0007] The adsorption column consists of two columns that can switch between each other. When continuous operation is required, one column can operate while the other is regenerated, eliminating the need for disassembly. Different sizes of adsorption columns can be selected based on the gas processing capacity.

[0008] The heating system is composed of three heating jackets, including a heating jacket wrapped around the adsorption column and a heating tube of the palladium membrane purification tube. The adsorption column is heated to about 280 DEG C by the heating jacket during regeneration, and the vacuum pump is used to complete the regeneration of the molecular sieve in the adsorption column. The heating jacket wrapped around the palladium membrane purification tube is used to heat the palladium membrane purification tube to ensure the normal operation of the palladium membrane purification tube, and the working temperature is 300 DEG C.

[0009] The dew point instrument is used to detect the heavy water content in the deuterium gas after adsorption, estimate the purity of the deuterium gas, and evaluate the purification effect of the membrane tube.

[0010] The deuterium gas alarm instrument is used to detect the deuterium gas concentration in real time, and sound and light alarms will be issued when there is hydrogen leakage. The deuterium gas leakage tester is a plug-in fixed type.

[0011] The electromagnetic valve is connected to the control system in the power control box and connected to the control panel to control the valve opening and realize the control of the deuterium gas flow.

[0012] The gas flow meter is used to detect and control the flow of deuterium-rich gas in real time. The deuterium gas flow meter is connected to the control panel through the USB interface, transmits the flow information to the control panel, and adjusts the opening of the electromagnetic valve through the software to control the flow.

[0013] The pressure sensor is an electronic pressure instrument that can transmit the pressure before and after the palladium membrane purification tube (the internal pressure of the deuterium gas purification device and the outlet pressure of the deuterium gas purification device) to the control panel to monitor the pressure of the deuterium gas purification device.

[0014] The palladium membrane purification tube is determined according to the processing capacity, which can be a single membrane component or a bundled membrane component, and is used to purify deuterium gas. The size of the palladium membrane purification tube can be selected according to the size of the deuterium gas processing capacity.

[0015] The vacuum pump is a combination of a molecular pump and a rotary vane pump, which is mainly used for the regeneration of the purification column and can also be used to evacuate the system.

[0016] The power supply and control box are used to place power supply equipment and control system equipment.

[0017] The control panel is actually a microcomputer embedded in an explosion-proof cabinet, which is used to control the operation of each device in the device and monitor the system parameters.

[0018] Compared with the prior art, the beneficial technical effects of the present invention are as follows: the adsorption columns in this application can be switched for use, with one column working while the other regenerates, without the need for disassembly, and can be used continuously, greatly reducing operation time, ensuring the stability of the purification system, and making the deuterium gas purification more thorough; the purification device is easy to operate, highly efficient, small in size, and easy to move, making it the first choice for small-scale deuterium production systems, especially suitable for semiconductor deuterium and laboratory deuterium, which helps to reduce the cost of deuterium gas production. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings.

[0020] Figure 1 A schematic diagram of the purification apparatus for preparing high-purity deuterium gas by electrolysis of heavy water.

[0021] Explanation of reference numerals in the attached diagram: 1. Explosion-proof cabinet for deuterium purification device; 11. Deuterium leak alarm; 12. Adsorption column; 13. Vacuum pump; 14. Palladium membrane purification tube; 15. Dew point meter; 16. Solenoid valve; 17, 42. Pressure sensor; 18. Gas flow meter; 19. Control panel; 20. Power supply and control system cabinet; 21, 22, 23, 24, 25, 26. Stainless steel valve; 27. Heating jacket for adsorption column; 41. Heating jacket for palladium membrane purification tube. Detailed Implementation

[0022] like Figure 1 As shown, the purification device for preparing high-purity deuterium gas by electrolysis of heavy water includes an adsorption column 12 for adsorbing and drying impurities in the raw gas, a vacuum pump 13 for regenerating and evacuating the adsorption column 12, and a palladium membrane purification tube 14 for purifying the deuterium gas coming out of the adsorption column 12.

[0023] An adsorption column heating sleeve 27 for regeneration is installed outside the adsorption column 12; a palladium membrane purification tube heating sleeve 41 is installed outside the palladium membrane purification tube 14.

[0024] Specifically, the outer surface of the adsorption column 12 is covered with an adsorption column heating sleeve 27; the outer surface of the palladium membrane purification tube 14 is covered with a palladium membrane purification tube heating sleeve 41.

[0025] In this embodiment, a cabinet for installing equipment components is also included; the cabinet is an explosion-proof cabinet; a deuterium leak alarm 11 is installed inside the cabinet; the deuterium leak alarm 11 is used to detect the deuterium concentration during operation, and will issue an audible and visual alarm when there is a hydrogen leak. The deuterium leak detector here is a plug-in fixed type, installed on the top of the explosion-proof cabinet of the deuterium purification device; it is used to monitor the deuterium concentration inside the explosion-proof cabinet and prevent deuterium leaks in the system.

[0026] At least two groups of the adsorption column 12 are installed in the cabinet, and one adsorption column is regenerated and the other is used in work.

[0027] In the embodiment, the regeneration and adsorption of the adsorption column 12 are synchronized by the plurality of adsorption columns 12. For example, the purification column is composed of two stainless steel columns with the same size, and the internal filler is 5A molecular sieve, which is used to adsorb the impurities such as heavy water gas in deuterium gas, so as to meet the purity requirement of the raw gas of the palladium membrane purification tube. The size of the purification column can be adjusted according to the processing capacity of the deuterium gas device, and the two columns can be switched back and forth.

[0028] In the embodiment, the adsorption column 12 is connected to the palladium membrane purification tube 14 by a pipeline, and a dew point instrument 15, a solenoid valve 16 and a gas flow meter 18 are installed on the pipeline. In the application, the dew point instrument 15 is used to monitor the purity of the gas out of the adsorption column 12; the solenoid valve 16 is used to control the flow of deuterium gas into the palladium membrane purification tube 14; the gas flow meter 18 is used to measure the flow of the purified gas; and two pressure sensors are used to monitor the pressure before and after the palladium membrane purification tube.

[0029] Specifically, the dew point instrument 15 is installed after the purification column 12, which is used to monitor the purity of the deuterium gas after being adsorbed by the adsorption column 12, and compare with the purity of the deuterium gas after the final purification, so as to investigate the purification effect of the palladium membrane purification tube 14.

[0030] In the embodiment, the solenoid valve 16 is installed before the inlet of the palladium membrane purifier 14, which is connected to the control system in the power control box and connected to the control panel, so as to control the opening of the valve and realize the control of the flow of deuterium gas.

[0031] The gas flow meter 18 is installed after the solenoid valve 16 and before the palladium membrane purification tube 14, which is used to detect and control the flow of the deuterium-rich gas in real time. The deuterium flow meter is connected to the control panel through the USB interface, and the flow information is transmitted to the control panel. The opening of the solenoid valve can be adjusted by the software to control the flow.

[0032] The pressure sensors (17 and 42) are installed at the gas inlet and outlet of the palladium membrane purification tube 14, respectively. The pressure sensors are electronic pressure instruments, which can transmit the pressure before and after the palladium membrane purification tube (the internal pressure of the deuterium purification device and the outlet pressure of the deuterium purification device) to the control panel, so as to monitor the pressure of the deuterium purification device.

[0033] In the cabinet, a control system is installed, which receives pressure sensor, dew point instrument 15, and opening degree of electromagnetic valve 16; a control panel 19 connected to the control system is installed outside the cabinet.

[0034] The heating system is divided into adsorption column heating jacket and palladium membrane purification tube heating jacket, which has temperature sensor inside to return temperature to the control panel and adjust temperature on the panel.

[0035] The vacuum pump 13 is a combination of molecular pump and rotary vane pump, which is used for regeneration of the purification column or evacuation of the system.

[0036] The palladium membrane purification tube 14 is determined according to the processing capacity, and the base material can be stainless steel or ceramic material, which can be single membrane assembly or bundled membrane assembly, used for deuterium gas purification and ultra-purification.

[0037] The vacuum pump is a combination of molecular pump and rotary vane pump, mainly used for regeneration of the purification column, and can also be used for evacuation of the system. When regenerating adsorption column A, close valves 21 and 22, open valve 25 connected to the vacuum pump, evacuate the gas in the adsorption column, and heat to 280℃ for 6-8 hours to complete the regeneration of adsorption column A. When regenerating adsorption column B, close valves 23 and 24, open valve 26 connected to the vacuum pump group, evacuate the gas in the adsorption column, and heat to 280℃ for 6-8 hours to complete the regeneration of adsorption column B. The adsorption column valve can also be an electric valve connected to the control system of the vacuum pump and adsorption column heating jacket, which realizes one-key regeneration on the control panel through the control program.

[0038] In this embodiment, the power supply and control box are used to place power supply equipment and control system equipment; the control panel is actually a microcomputer embedded on the explosion-proof cabinet, which is used to control the heating parameters of the heating jacket in the deuterium gas purification device, the start and stop of the vacuum pump group, the operation of the electromagnetic valve, and the visualization of the data of various monitoring instruments such as pressure; the internal gas circuit of the deuterium gas purification device is made of internally polished 316L stainless steel pipe, and the joints are made of stainless steel double sleeve to ensure the cleanliness and good air tightness of the internal pipeline.

[0039] Case 1:

[0040] 1. Analyze the product gas by electrolysis of heavy water with a purity of 99.7%, and obtain deuterium gas with a purity of 99.5%, and the H2O / D2O content is 110ppm.

[0041] 2. Connect the purification device to the outlet of the electrolysis device, evacuate and dry the purification device, the evacuation depth is 10-6pa, and keep for 8 hours, then start the electrolysis device and the purification device, and start the purification work.

[0042] 3, the deuterium purification device processing capacity is 2Nm3 / h, two adsorption column filler area height 50cm, diameter 5cm, using 316L stainless steel material, wall thickness 2mm, filler is 5A molecular sieve. Palladium membrane purification tube for single tube design, length 60cm, base material is ceramic material, palladium membrane thickness is 14 microns. First start the equipment, the system is evacuated to 10-6pa, palladium membrane purification tube heating jacket, temperature rises to 350℃.

[0043] 4, close valve 21, valve 22, valve 25, adsorption column B work, enter the adsorption column for adsorption. From the adsorption column out of deuterium dew point instrument detection dew point temperature is-85℃. In through solenoid valve 16 into palladium membrane purification tube, purification tube working temperature 350℃, after purification, product gas outlet pressure 0.3Mpa, tail gas from palladium membrane purification tube tail gas pipe flow out.

[0044] 5, the palladium membrane purification tube product deuterium product analysis, its chemical purity 99.9996%. Among them, H2O / D2O content is 0.8ppm.

[0045] 6, the adsorption column B regeneration, close valve 23, valve 24, open valve 26, start vacuum pump evacuation. The vacuum pump is a pump group of mechanical pump and molecular pump, according to the pump pressure instrument display can be evacuated to 10 -6 Pa, start B column heating jacket heating to 200℃, regeneration 6h, switch to B column work again, through the dew point instrument detection, show that its adsorption effect is good, the adsorption column regeneration effect is good.

[0046] Case two:

[0047] 1, using purity of 99.9% of heavy water electrolysis, product gas analysis, get the gas purity of 99.7% of deuterium, the H2O / D2O content is 25ppm.

[0048] 2, the purification device is connected to the electrolysis device outlet, the purification device is evacuated, dried, evacuation depth 10-6pa, keep 8 hours, then start the electrolysis device and purification device, begin purification work.

[0049] 3, the deuterium purification device processing capacity is 2Nm3 / h, two adsorption column filler area height 50cm, diameter 5cm, using 316L stainless steel material, wall thickness 2mm, filler is 5A molecular sieve. Palladium membrane purification tube for single tube design, length 60cm, base material is ceramic material, palladium membrane thickness is 14 microns. First start the equipment, the system is evacuated to 10-6pa, palladium membrane purification tube heating jacket, temperature rises to 350℃.

[0050] 4. Close valve 21, valve 22, valve 25, adsorption column B works, into the adsorption column for adsorption. Deuterium gas from the adsorption column is detected by dew point instrument, the dew point temperature is -85℃. After entering the palladium membrane purification tube through electromagnetic valve 16, the working temperature of the purification tube is 350℃, after purification, the product gas outlet pressure is 0.3Mpa, the tail gas flows out from the palladium membrane purification tube tail gas pipe.

[0051] 5. The deuterium product gas from the palladium membrane purification tube is analyzed, the chemical purity is 99.99993%, and the H2O / D2O content is 0.4ppm

[0052] 6. Regenerate the adsorption column B, close valve 23, valve 24, open valve 26, start the vacuum pump to evacuate. The vacuum pump is a pump group of mechanical pump and molecular pump, according to the display of the pressure instrument on the pump, it can be evacuated to 10 -6 Pa, start the heating jacket of B column to heat to 200℃, regenerate for 6h, then switch to B column work, through the dew point instrument detection, it shows that the adsorption effect is good, the regeneration effect of the adsorption column is good.

[0053] The above examples only describe the preferred mode of the present application, and do not limit the scope of the present application, under the premise of not departing from the design spirit of the present application, various modifications and improvements of the technical solutions of the present application made by those skilled in the art shall fall within the protection scope determined by the claims of the present application.

Claims

1. A purification apparatus for the production of high purity deuterium gas from electrolytic heavy water, characterized by: It comprises an adsorption column (12) for adsorbing and drying impurities in raw gas, a vacuum pump (13) for regenerating and vacuumizing the adsorption column (12), and a palladium membrane purifier (14) for purifying deuterium gas from the adsorption column (12); Wherein, an adsorption column heating jacket (27) for regeneration is arranged outside the adsorption column (12); A palladium membrane purifier heating jacket (41) is arranged outside the palladium membrane purifier (14); It further comprises a cabinet for installing equipment components; Or / and, a deuterium gas leakage alarm (11) is arranged in the cabinet; Or / and, the cabinet is an explosion-proof cabinet; The adsorption column (12) is connected to the palladium membrane purifier (14) by a pipeline, and a dew point instrument (15), a solenoid valve (16), and a gas flow meter (18) are arranged on the pipeline; wherein, pressure sensors are arranged at the gas inlet and outlet of the palladium membrane purifier (14); The dew point instrument (15) is used to monitor the purity of gas from the adsorption column (12); The solenoid valve (16) is used to control the flow of deuterium gas into the palladium membrane purifier (14) for purification; The gas flow meter (18) is used to measure the flow of purified gas; Two pressure sensors are used to monitor the pressure before and after the palladium membrane purifier.

2. The purification apparatus for the production of high purity deuterium gas from electrolytic heavy water according to claim 1, characterized in that: At least two groups of adsorption columns (12) are arranged in the cabinet, wherein one adsorption column is regenerated and the other is used for work; Or / and, molecular sieves are loaded in the adsorption column (12); Or / and, the molecular sieves are 5A molecular sieves; Or / and, the adsorption column (12) is coated with an adsorption column heating jacket (27) on the outer surface.

3. The purification device for preparing high-purity deuterium gas from electrolytic heavy water according to claim 2, characterized in that: A control system is further arranged in the cabinet, wherein the control system receives the pressure sensors, the dew point instrument (15), and the opening degree of the solenoid valve (16); A control panel (19) connected to the control system is arranged outside the cabinet.

4. The purification device for preparing high-purity deuterium gas from electrolytic heavy water according to claim 1, characterized in that: The vacuum pump (13) is a combination of a molecular pump and a rotary vane pump, which is used for regenerating the purification column or for vacuumizing the system.

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