Helium extraction system

Abstract

The helium extraction system is used for extracting helium in BOG and comprises a low-temperature rectification device, a catalytic dehydrogenation device, a drying device and a pressure swing adsorption device which are sequentially connected through a pipeline. The low-temperature rectification device can rectify and concentrate helium in BOG, the catalytic dehydrogenation device can catalytically oxidize hydrogen in the BOG and remove the hydrogen in the BOG, the drying device can remove moisture in the BOG, and the pressure swing adsorption device is a normal-temperature pressure swing adsorption device and can separate and purify the helium in the BOG; the low-temperature rectification device comprises a first compressor, a heat exchanger, a rectification tower, a condensation evaporator, a gas-liquid separator and a second compressor, the inlet end of the first compressor can be connected with a BOG gas source, and the first compressor, the rectification tower, the condensation evaporator and the gas-liquid separator are sequentially connected through pipelines; a connecting pipeline between the first compressor and the BOG gas source and a connecting pipeline between the first compressor and the rectifying tower respectively form a circulation loop through the heat exchanger, the second compressor and the condensation evaporator; according to the extraction system, the number of dynamic equipment and static equipment in an existing device for extracting helium from BOG is reduced, the input cost is reduced, and the energy consumption and the operation difficulty are reduced.

Description

Technical Field

[0001] The present application relates to the technical field of helium production, and in particular to a helium extraction system. Background Art

[0002] Natural gas separation is currently the main method for producing helium. The processes for extracting helium from natural gas mainly include non-cryogenic and cryogenic methods. The non-cryogenic method uses a combination of membrane separation and pressure swing adsorption to separate the gas components in natural gas through a semi-permeable membrane made of special materials, thereby increasing the concentration of helium in the gas components, and then adsorbs impurities in natural gas through activated carbon or other adsorption materials, and then gradually purifies the helium through multiple adsorption and regeneration steps. The cryogenic helium extraction process uses liquid nitrogen as a cold source to cool and liquefy BOG (Boil-Off Gas, flash steam) gas, and achieves the purpose of extracting crude helium through multi-stage condensation separation, and then adsorbs and removes other impurities at low temperatures to achieve the purpose of purifying helium.

[0003] However, the separation membrane in the non-cryogenic method is easily contaminated and damaged, has a short lifespan, needs to be replaced regularly, and has high subsequent investment costs. In addition, the selectivity of membrane separation technology is limited by the membrane material and the pore size of the separation membrane. For some gas molecules of similar molecular size, the separation effect may not be ideal. In addition, membrane separation technology has high requirements for gas flow and pressure, which require precise control and regulation. Cryogenic extraction of helium requires a large amount of liquid nitrogen, a large number of supporting equipment, complex operation, high energy consumption, and high initial investment costs.

[0004] It can be seen that the existing technology still needs to be improved and enhanced. Utility Model Content

[0005] In view of the above-mentioned deficiencies in the prior art, the purpose of the present application is to provide a helium extraction system, aiming to reduce the operational difficulty and production cost of helium preparation.

[0006] In order to achieve the above objectives, this application adopts the following technical solutions:

[0007] On one hand, the present application discloses a helium extraction system for extracting helium from BOG, the extraction system comprising: a cryogenic distillation device, a catalytic dehydrogenation device, a drying device and a pressure swing adsorption device, wherein the cryogenic distillation device, the catalytic dehydrogenation device, the drying device and the pressure swing adsorption device are sequentially connected through pipelines; the cryogenic distillation device is used to distill and concentrate the concentration of helium in BOG, the catalytic dehydrogenation device is used to catalytically oxidize the hydrogen in BOG to remove the hydrogen in BOG, the drying device is used to remove moisture in BOG, and the pressure swing adsorption device is a normal temperature pressure swing adsorption device, which is used to separate and purify the helium in BOG;

[0008] The cryogenic distillation device comprises a first compressor, a heat exchanger, a distillation tower, a condenser evaporator, and a gas-liquid separator, wherein the inlet end of the first compressor can be connected to a BOG gas source, the first compressor, the distillation tower, the condenser evaporator, and the gas-liquid separator are sequentially connected by pipelines, and the connecting pipeline between the first compressor and the BOG gas source and the connecting pipeline between the first compressor and the distillation tower pass through the heat exchanger respectively, and a circulation loop is formed between the second compressor and the condenser evaporator.

[0009] In some embodiments of the present application, the distillation tower includes a bottom, a distillation section and a head, a reboiler is provided in the bottom of the tower, the reboiler includes an air inlet and a first outlet, the air inlet is connected to the outlet end of the first compressor through a second pipe, and the second pipe passes through the heat exchanger; the first outlet is connected to the distillation section through a third pipe; a second outlet is provided at the bottom of the bottom of the tower, and the second outlet can be connected to a fuel gas recovery pipe; a third outlet is provided on the head, and a feed port is provided on the condenser evaporator, and the third outlet is connected to the feed port through a fourth pipe.

[0010] In some embodiments of the present application, the gas-liquid separator is provided with a fourth outlet and a first reflux port, the fourth outlet is connected to the catalytic dehydrogenation device, and the first reflux port is connected to the distillation tower.

[0011] In some embodiments of the present application, the condenser evaporator includes a coolant inlet and a coolant outlet, the second compressor includes a fifth inlet and a fifth outlet, the fifth outlet is connected to the coolant inlet via a first circulation pipe, the coolant outlet is connected to the fifth inlet via a second circulation pipe, and the first circulation pipe and the second circulation pipe pass through the heat exchanger respectively.

[0012] In some embodiments of the present application, the catalytic dehydrogenation device includes a dehydrogenation reactor, a first cooler and a first water separator, the air inlet end of the dehydrogenation reactor is connected to the gas-liquid separator through a sixth pipeline, and the air outlet end of the dehydrogenation reactor is connected to the first cooler and the first water separator in sequence through a seventh pipeline; the air inlet end of the dehydrogenation reactor is also connected to an oxygen gas source.

[0013] In some embodiments of the present application, the drying device includes a precooler, a second water separator and a dryer which are sequentially connected by pipelines, and the precooler is also arranged on the circulation pipeline between the condenser evaporator and the first compressor.

[0014] In some embodiments of the present application, the dryer includes a first drying unit and a second drying unit, the first drying unit includes a sixth inlet and a sixth outlet, the sixth inlet is connected to the second water separator, and the sixth outlet is connected to the pressure swing adsorption device; the second drying unit is connected to the first drying unit, the second drying unit includes a seventh outlet and a seventh inlet, the seventh outlet and the seventh pipeline are connected between the dehydrogenation reactor and the first cooler, the pressure swing adsorption device is provided with a second reflux port, the seventh inlet is connected to the second reflux port through a fourteenth pipeline, and the fourteenth pipeline is connected to the distillation tower through a thirteenth pipeline.

[0015] In some embodiments of the present application, the thirteenth pipeline passes through the heat exchanger.

[0016] In some embodiments of the present application, the pressure swing adsorption device further includes a ninth outlet, and the ninth outlet is used to discharge the purified helium.

[0017] In some embodiments of the present application, a third compressor is disposed on the fourteenth pipeline, and an air inlet end of the third compressor faces the pressure swing adsorption device.

[0018] In some embodiments of the present application, the extraction system further includes a membrane press and a bus, the inlet end of the membrane press is connected to the ninth outlet, the outlet end of the membrane press is connected to the bus, and the bus is used for filling helium.

[0019] Beneficial effects:

[0020] The present application provides a helium extraction system, which can achieve the goal of first increasing the concentration of helium in a mixed gas and then gradually removing impurity gases to obtain high-purity helium by arranging a cryogenic distillation device, a catalytic dehydrogenation device, a drying device and a pressure swing adsorption device which are sequentially connected by pipelines; the layout of each device in the extraction system is reasonable and the structure is simple; the cryogenic distillation device is only provided with one heat exchanger, which reduces the number of dynamic equipment and static equipment and reduces the equipment investment cost; in addition, the pressure swing adsorption device adopts a normal temperature pressure swing adsorption device, which saves cold sources, reduces energy consumption and operation difficulty, and also reduces the equipment's requirements for materials. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic structural diagram of a helium extraction system provided in one embodiment of the present application.

[0022] Description of main component symbols:

[0023] 1. Cryogenic distillation device; 11. First compressor; 12. Heat exchanger; 13. Distillation tower; 131. Tower bottom; 132. Distillation section; 133. Header; 134. Second outlet; 135. Third outlet; 14. Condenser evaporator; 141. Feed inlet; 142. Coolant inlet; 143. Coolant outlet; 15. Gas-liquid separator; 151. Fourth outlet; 152. First reflux port; 16. Second compressor; 161. Fifth inlet; 162. Fifth outlet; 17. Reboiler; 171. Air inlet; 172. First outlet; 18. Throttle valve;

[0024] 2. Catalytic dehydrogenation device; 21. Dehydrogenation reactor; 22. First cooler; 23. First water separator;

[0025] 3. Drying device; 31. Precooler; 32. Second water separator; 33. Dryer; 331. First drying unit; 3311. Sixth inlet; 3312. Sixth outlet; 332. Second drying unit; 3321. Seventh outlet; 3322. Seventh inlet;

[0026] 4. Pressure swing adsorption device; 41. Pressure swing helium extraction unit; 411. Ninth outlet; 412. Second reflux port; 42. Third compressor;

[0027] 5. Pressurized filling device; 51. Membrane press; 52. Busbar;

[0028] 01, first pipeline; 02, second pipeline; 03, third pipeline; 04, fourth pipeline; 05, fuel gas recovery pipeline; 06, first circulation pipeline; 07, second circulation pipeline; 08, sixth pipeline; 09, seventh pipeline; 010, thirteenth pipeline; 011, fourteenth pipeline. DETAILED DESCRIPTION

[0029] The present application provides a helium extraction system. To make the purpose, technical solution and effect of the present application clearer and more specific, the present application is further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific examples described here are only used to explain the present application and are not used to limit the present application.

[0030] In the description of the present application, it should be understood that the terms "upper", "lower", "left", "right", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, and a specific orientation structure and operation, and therefore, cannot be understood as a limitation on the present application. In addition, "first" and "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise specified, "multiple" means two or more.

[0031] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or mutual communication; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0032] See also Figure 1 The present application provides a helium extraction system, which is used for extracting helium from BOG and can achieve a helium recovery rate of not less than 98%, and the purity of the recovered helium can be as high as 99.999%, greatly improving the recovery rate and purity of the helium in BOG.

[0033] Specifically, the extraction system includes a cryogenic distillation device 1, a catalytic dehydrogenation device 2, a drying device 3, and a pressure swing adsorption device 4, which are connected in sequence through pipelines. The cryogenic distillation device 1 can distill and concentrate the concentration of helium in BOG, separate the combustion gases such as methane in BOG, and discharge the non-condensable components (nitrogen, helium, etc.) in BOG from the top of the tower in a gas phase state and enter the next process, thereby increasing the concentration of helium in the mixed gas and improving the efficiency of the subsequent process. The catalytic dehydrogenation device 2 can catalytically oxidize the hydrogen in BOG, so that the hydrogen after the catalytic reaction is converted into water, thereby removing the hydrogen in BOG. The drying device 3 can remove water carried in BOG, and the pressure swing adsorption device 4 adopts a normal temperature pressure swing adsorption device 4, which can separate and purify helium in BOG; compared with the low temperature pressure swing adsorption device 4, the normal temperature pressure swing adsorption device 4 does not need to be cooled to a low temperature, which can reduce the consumption of cold sources and reduce process costs; in addition, the normal temperature pressure swing adsorption device 4 does not need to be set up with a complex refrigeration system, so it can reduce the initial investment cost of the equipment, and the equipment structure is relatively simple, the cost required during maintenance and operation is low, and the failure rate is also relatively low.

[0034] The cryogenic distillation device 1 includes a first compressor 11, a heat exchanger 12, a distillation tower 13, a condenser evaporator 14, a gas-liquid separator 15, and a second compressor 16. The inlet end of the first compressor 11 can be connected to the BOG gas source through a first pipeline 01. The first compressor 11, the distillation tower 13, the condenser evaporator 14 and the gas-liquid separator 15 are connected in sequence by pipelines. The heat exchanger 12 is provided with a first connection inlet, a first connection outlet, a second connection inlet, and a second connection outlet. The first compressor 11 is connected to the BOG gas source through a first pipeline 01. A pipeline 01 enters the heat exchanger 12 from the first connection inlet, and then extends from the first connection outlet to the outside of the heat exchanger 12, so that the BOG in the first pipeline 01 exchanges heat with the heat source in the heat exchanger 12, is reheated and heated, and then enters the first compressor 11 to be compressed. The connecting pipeline between the first compressor 11 and the distillation tower 13 enters the heat exchanger 12 from the second connection inlet to exchange heat with the cold source, and then extends from the second connection outlet to the outside of the heat exchanger 12, so that the compressed BOG can be cooled before entering the heat exchanger 12.

[0035] Unheated BOG is usually at a lower temperature and may contain more condensate water, which increases the risk of corrosion of the first compressor 11. By reheating BOG, the water can be evaporated, reducing the possibility of corrosion of the first compressor 11. In addition, the closer the gas is to the liquid, the smaller its compression ratio is. By heating BOG to a temperature close to the liquefaction temperature, the work required for the first compressor 11 can be reduced, the efficiency of the first compressor 11 can be improved, and energy consumption can be reduced. After the heated BOG is compressed, the boiling point difference of its components is more obvious, which is conducive to the subsequent separation units (distillation tower 13, condenser evaporator 14, gas-liquid separator 15, etc.) to more effectively separate helium and other components.

[0036] The temperature of the compressed BOG is relatively high. High-temperature BOG may generate thermal stress on systems such as pipelines and valves. The cooling by the heat exchanger 12 can reduce the temperature of the BOG to a temperature close to the liquefaction temperature, thereby reducing the thermal stress and extending the service life of the equipment.

[0037] A circulation loop is formed between the second compressor 16 and the condenser evaporator 14 for circulating the coolant. In some embodiments, the coolant is liquid nitrogen, and the second compressor 16 circulates nitrogen gas for throttling refrigeration to provide a cold source for the heat exchanger 12 and the condenser evaporator 14.

[0038] In some embodiments of the present application, the condenser evaporator 14 includes a coolant inlet 142 and a coolant outlet 143, the second compressor 16 includes a fifth inlet 161 and a fifth outlet 162, and the fifth outlet 162 is connected to the coolant inlet 142 through the first circulation pipeline 06. The coolant outlet 143 is connected to the fifth inlet 161 through the second circulation pipeline 07, and the first heat exchanger 12 also includes a third connection inlet, a third connection outlet, a fourth connection inlet, and a fourth connection outlet. The first circulation pipeline 06 enters the heat exchanger 12 from the third connection inlet, so that the coolant in the first circulation pipeline 06 exchanges heat with the cold source in the heat exchanger 12, is cooled, and then extends from the third connection outlet to the outside of the heat exchanger 12, and is connected to the coolant inlet 142 of the condenser evaporator 14; after the coolant exchanges heat with BOG in the condenser evaporator 14, it is discharged from the coolant outlet 143 of the condenser evaporator 14 and enters the second circulation pipeline 07. The second circulation pipeline 07 enters the heat exchanger 12 from the fourth connection inlet of the heat exchanger 12, and then exchanges heat with the cold source in the heat exchanger 12, so that the coolant is cooled again, and then extends from the fourth connection outlet to the outside of the heat exchanger 12, and is connected to the fifth inlet 161 of the second compressor 16. The second compressor 16 provides power for the circulation of the coolant, and the coolant can continuously exchange heat with the BOG in the condenser evaporator 14 to ensure the continuity of the process.

[0039] In some embodiments of the present application, the distillation tower 13 includes a tower bottom 131, a distillation section 132 and a head 133. A reboiler 17 is provided in the tower bottom 131. The reboiler 17 includes an air inlet 171 and a first outlet 172. The air inlet 171 is connected to the outlet end of the first compressor 11 through a second pipeline 02, and the second pipeline 02 passes through a heat exchanger 12; the first outlet 172 is connected to the distillation section 132 through a third pipeline 03. A throttle valve 18 is provided on the third pipeline 03, which can control the flow rate of gas from the reboiler 17 into the distillation section 132 of the distillation tower 13, thereby adjusting the distillation effect of the distillation tower 13. A second outlet 134 is provided at the bottom of the tower bottom 131, and the second outlet 134 can be connected to the fuel gas recovery pipeline 05, so that the methane liquefied from the BOG in the distillation tower 13 can be recycled from the fuel gas recovery pipeline 05 for reuse, thereby improving the economy of the BOG and avoiding pollution to the environment. The fuel gas recovery pipeline 05 also passes through the heat exchanger 12, so that the fuel gas flowing out of the distillation tower 13 is reheated and then recycled. The head 133 is provided with a third outlet 135, and the condenser evaporator 14 is provided with a feed port 141. The third outlet 135 is connected to the feed port 141 through the fourth pipeline 04. The third outlet 135 is provided at the top of the head 133 to facilitate the escape of non-condensable gases such as helium.

[0040] The gas-liquid separator 15 is provided with a fourth outlet 151 and a first reflux port 152. The fourth outlet 151 is arranged at the top of the gas-liquid separator 15, and the fourth outlet 151 is connected to the catalytic dehydrogenation device 2, so as to facilitate the discharge of non-condensable gas components (nitrogen, helium, etc.) to the next equipment; the first reflux port 152 is arranged at the bottom of the gas-liquid separator 15, and the first reflux port 152 is connected to the distillation tower 13, so that the condensate can be completely refluxed into the distillation tower 13.

[0041] The catalytic dehydrogenation device 2 includes a dehydrogenation reactor 21, a first cooler 22 and a first water separator 23. The gas inlet end of the dehydrogenation reactor 21 is connected to the gas-liquid separator 15 through the sixth pipeline 08, and the gas outlet end of the dehydrogenation reactor 21 is connected to the first cooler 22 and the first water separator 23 in sequence through the seventh pipeline 09; the gas inlet end of the dehydrogenation reactor 21 is also connected to an oxygen gas source. The crude helium extracted by the distillation tower 13 and separated by the gas-liquid separator 15 is converted into water after being catalytically oxidized by oxygen in the dehydrogenation reactor 21. The crude helium is cooled by the first cooler 22, which is more convenient for separating water and gas components, and then part of the water is separated by the first water separator 23 to reduce the load of the drying device 3.

[0042] The drying device 3 includes a precooler 31, a second water separator 32 and a dryer 33 which are connected in sequence by pipelines. The precooler 31 is also arranged on the circulation pipeline between the condenser evaporator 14 and the first compressor 11. The crude helium after the catalytic dehydrogenation device 2 first passes through the precooler 31 and then passes through the second water separator 32 to separate part of the water, which can greatly reduce the load of the dryer 33.

[0043] In some embodiments of the present application, the dryer 33 includes a first drying unit 331 and a second drying unit 332, the first drying unit 331 includes a sixth inlet 3311 and a sixth outlet 3312, the sixth inlet 3311 is connected to the second water separator 32, and the sixth outlet 3312 is connected to the pressure swing adsorption device 4, which is used to dry the crude helium passing through the second water separator 32; the second drying unit 332 is connected to the first drying unit 331, the second drying unit 332 includes a seventh outlet 3321 and a seventh inlet 3322, and the seventh outlet 3321 is connected to the seventh pipeline 09 between the dehydrogenation reactor 21 and the first cold The pressure swing adsorption device 4 is provided with a second reflux port 412 between the dryer 22, the seventh inlet 3322 is connected to the second reflux port 412 through the fourteenth pipeline 011, and the fourteenth pipeline 011 is connected to the distillation tower 13 through the thirteenth pipeline 010. The desorbed gas of the pressure swing adsorption device 4 generally contains nitrogen, and a small amount of methane, helium, etc. The above arrangement enables the desorbed gas of the pressure swing adsorption device 4 to be used as the regeneration gas of the dryer 33, and part of the desorbed gas is refluxed to the distillation tower 13 for re-distillation and purification, avoiding the reduction of the helium extraction rate caused by venting the desorbed gas, reducing the loss of helium, and thus improving the helium extraction rate. A flow control valve body is provided on the connecting channel between the first drying unit 331 and the second drying unit 332, which can control the flow of the desorbed gas entering the first drying unit 331.

[0044] Furthermore, the heat exchanger 12 is also provided with a fifth connection inlet and a fifth connection outlet. The thirteenth pipeline 010 enters the heat exchanger 12 through the fifth connection inlet, so that the regenerated gas in the thirteenth pipeline 010 is cooled and then extends from the fifth connection outlet to the outside of the heat exchanger 12 and is connected to the distillation section 132 of the distillation tower 13, so that the desorbed gas of the pressure swing adsorption can be distilled and purified again.

[0045] In some embodiments of the present application, the pressure swing adsorption device 4 includes a plurality of pressure swing helium extraction units 41, and adjacent pressure swing helium extraction units 41 are connected by pipelines. Different numbers of pressure swing helium extraction units 41 can be set according to different production requirements, which is highly flexible. The pressure swing adsorption device 4 also includes a ninth outlet 411, which is set in one of the pressure swing helium extraction units 41 for discharging purified helium.

[0046] A third compressor 42 is provided on the fourteenth pipeline 011, and the air inlet end of the third compressor 42 faces the pressure swing adsorption device 4, so that the desorbed gas generated by the pressure swing adsorption unit is compressed and then returned to the drying device 3 or the distillation tower 13, thereby improving the stability of the gas pressure.

[0047] The helium extraction system also includes a pressurizing and filling device 5, which includes a membrane press 51 and a bus 52. The inlet end of the membrane press 51 is connected to the ninth outlet 411, and the outlet end of the membrane press 51 is connected to the bus 52. The helium discharged from the pressure swing adsorption device 4 can be loaded onto a vehicle after being pressurized by the membrane press 51, or can be filled into a cylinder through the bus 52.

[0048] In summary, the present application realizes efficient extraction of helium from BOG by providing a low-temperature distillation device, a catalytic dehydrogenation device, a drying device and a pressure swing adsorption device connected in sequence by pipelines, and the device does not need to be provided with a multi-stage distillation system, reduces the installation of static equipment such as heat exchangers and separators and dynamic equipment such as compression pumps, and reduces investment costs; the pressure swing adsorption device adopts a normal temperature pressure swing adsorption device, reduces the loss of cold source, reduces the difficulty of operating the equipment, and improves the flexibility of equipment combination.

[0049] In addition, the desorbed gas from the pressure swing adsorption device is pressurized by the third compressor through the second reflux port and circulated to the dryer as regeneration gas and returned to the distillation tower for distillation and purification. There is no tail gas venting treatment in the entire process, which reduces the loss of helium, improves the helium extraction rate, and achieves a helium extraction rate of more than 98%.

[0050] It is understandable that those skilled in the art can make equivalent substitutions or changes based on the technical solution and application concept of the present application, and all these changes or substitutions should fall within the protection scope of the claims attached to the present application.

Claims

1. A helium extraction system, It is characterized in that Used for extracting helium from BOG, the extraction system comprises: A cryogenic distillation device, comprising a first compressor, a heat exchanger, a distillation tower, a condenser evaporator, a gas-liquid separator and a second compressor, wherein the inlet end of the first compressor can be connected to a BOG gas source, the first compressor, the distillation tower, the condenser evaporator and the gas-liquid separator are sequentially connected by pipelines, and the connecting pipeline between the first compressor and the BOG gas source and the connecting pipeline between the first compressor and the distillation tower pass through the heat exchanger respectively, and a circulation loop is formed between the second compressor and the condenser evaporator; Catalytic dehydrogenation device, used to catalytically oxidize the hydrogen in BOG to remove the hydrogen in BOG; A drying device for removing moisture from BOG; and A pressure swing adsorption device, which is a normal temperature pressure swing adsorption device used to separate and purify helium in BOG; The cryogenic distillation device, the catalytic dehydrogenation device, the drying device and the pressure swing adsorption device are connected in sequence through pipelines.

2. The helium extraction system according to claim 1, It is characterized in that The distillation tower includes a tower kettle, a distillation section and a head. A reboiler is provided in the tower kettle. The reboiler includes an air inlet and a first outlet. The air inlet is connected to the outlet end of the first compressor through a second pipeline, and the second pipeline passes through the heat exchanger; the first outlet is connected to the distillation section through a third pipeline; a second outlet is provided at the bottom of the tower kettle, and the second outlet can be connected to a fuel gas recovery pipeline; a third outlet is provided on the head, and a feed inlet is provided on the condenser evaporator, and the third outlet is connected to the feed inlet through a fourth pipeline.

3. The helium extraction system according to claim 2, It is characterized in that The gas-liquid separator is provided with a fourth outlet and a first reflux port, the fourth outlet is connected to the catalytic dehydrogenation device, and the first reflux port is connected to the distillation tower.

4. The helium extraction system according to claim 1, It is characterized in that The condenser evaporator includes a coolant inlet and a coolant outlet, the second compressor includes a fifth inlet and a fifth outlet, the fifth outlet is connected to the coolant inlet via a first circulation pipeline, the coolant outlet is connected to the fifth inlet via a second circulation pipeline, and the first circulation pipeline and the second circulation pipeline pass through the heat exchanger respectively.

5. The helium extraction system according to claim 1, It is characterized in that The catalytic dehydrogenation unit includes: A dehydrogenation reactor, a first cooler and a first water separator, wherein the gas inlet end of the dehydrogenation reactor is connected to the gas-liquid separator via a sixth pipeline, and the gas outlet end of the dehydrogenation reactor is connected to the first cooler and the first water separator in sequence via a seventh pipeline; The gas inlet end of the dehydrogenation reactor is also connected to an oxygen gas source.

6. The helium extraction system according to claim 5, It is characterized in that The drying device comprises a precooler, a second water separator and a dryer which are sequentially connected by pipelines. The precooler is also arranged on a circulation pipeline between the condensing evaporator and the first compressor.

7. The helium extraction system according to claim 6, It is characterized in that The dryer comprises: a first drying unit, comprising a sixth inlet and a sixth outlet, wherein the sixth inlet is connected to the second water separator, and the sixth outlet is connected to the pressure swing adsorption device; A second drying unit is connected to the first drying unit, the second drying unit includes a seventh outlet and a seventh inlet, the seventh outlet and the seventh pipeline are connected between the dehydrogenation reactor and the first cooler, the pressure swing adsorption device is provided with a second reflux port, the seventh inlet is connected to the second reflux port through a fourteenth pipeline, and the fourteenth pipeline is connected to the distillation tower through a thirteenth pipeline.

8. The helium extraction system according to claim 7, It is characterized in that The thirteenth pipeline passes through the heat exchanger.

9. The helium extraction system according to claim 7, It is characterized in that The pressure swing adsorption device further comprises a ninth outlet, and the ninth outlet is used to discharge the purified helium.

10. The helium extraction system according to claim 7, It is characterized in that The fourteenth pipeline is provided with a third compressor, and an air inlet end of the third compressor faces the pressure swing adsorption device.

11. The helium extraction system according to claim 9, It is characterized in that The extraction system further comprises a membrane press and a bus, wherein the inlet end of the membrane press is connected to the ninth outlet, and the outlet end of the membrane press is connected to the bus, and the bus is used for filling helium.

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