Helium refining method and device

Abstract

The present invention discloses a helium refining method and device thereof, and relates to the technical field of natural gas processing and helium recovery. The device comprises a crude helium extraction unit, a catalytic dehydrogenation unit, a helium refining unit and a filling unit. The BOG raw gas is subjected to the crude helium extraction unit to obtain a mixed gas of hydrogen and helium with a content of more than 95%, the hydrogen content is reduced to less than 1 ppm by the catalytic dehydrogenation unit, and the gas is purified to high-purity helium that meets the requirements by the helium refining unit. The crude helium extraction unit of the present invention adopts a room temperature pressure swing adsorption coupled membrane separation method to extract helium, which solves the problems of high energy consumption, low operational flexibility, unstable operation and high investment in low-temperature processes. At the same time, the analytical gas and the downstream vent gas generated by the room temperature pressure swing adsorption component are recycled, and a dirty gas re-purification pipeline interface is provided to reduce the pressure of the low-purity helium and return it to the helium refining unit for re-purification, thereby realizing the secondary recovery of methane-rich gas and improving the recovery rate of helium.

Description

Technical Field

[0001] The present invention relates to the technical field of natural gas processing and helium recovery, and in particular to a helium refining method and a device thereof. Background Art

[0002] Helium, a rare strategic resource, has important applications in the semiconductor, medical, petrochemical, aerospace, and maritime sectors. Currently, commercial helium primarily comes from byproducts of natural gas processing or liquefied natural gas (LNG) production. Liquefied natural gas boil-off gas (LNG-BOG) has a high helium content, meeting the requirements for helium extraction feedstock. Therefore, BOG can be used for helium extraction.

[0003] The existing helium extraction technology is a low-temperature helium extraction process. The mainstream helium extraction devices in the world all use a cryogenic separation process to extract helium, using refrigerators or liquid nitrogen as cold sources and utilizing the differences in critical temperatures of various components in natural gas to achieve helium separation. This is suitable for working conditions with large helium content and processing capacity in natural gas. However, when the scale of the device is small, the cryogenic separation process has the problems of high energy consumption, low operational flexibility, unstable operation and poor economic benefits in the low-temperature process. Summary of the Invention

[0004] In view of the above problems existing in the prior art, the first technical problem to be solved by the present invention is to provide a helium refining device; the second technical problem to be solved by the present invention is to provide a method for refining helium using the device.

[0005] The technical solution adopted in the present invention is as follows:

[0006] A crude helium refining device comprises a crude helium extraction unit, a catalytic dehydrogenation unit, a helium refining unit and a filling unit; the crude helium extraction unit, the catalytic dehydrogenation unit, the helium refining unit and the filling unit are connected in sequence through pipelines.

[0007] The crude helium extraction unit includes a room temperature pressure swing adsorption component and a membrane separation component which are connected in sequence.

[0008] The room temperature pressure swing adsorption component performs pressurized adsorption, normal pressure or reduced pressure analysis at room temperature through the equilibrium adsorption capacity of the adsorbent.

[0009] The membrane separation module separates the gas components by transferring and separating the gas components at different permeation rates to obtain the permeate gas of the membrane separation module and the non-permeate gas of the membrane separation module.

[0010] The crude helium extraction unit separates helium, hydrogen, methane and nitrogen by utilizing the different molecular polarities and particle sizes of different components in the mixed gas.

[0011] The catalytic dehydrogenation unit includes a catalytic dehydrogenation reactor, a water cooler, a gas-liquid separator, an adsorption dryer, a circulating compressor, a flow meter and a hydrogen analyzer; the flow meter and the hydrogen analyzer are respectively arranged on the air inlet pipe and the air outlet pipe of the catalytic dehydrogenation unit.

[0012] The helium refining unit includes a crude helium compressor and a helium purifier connected in sequence.

[0013] The permeate gas outlet of the membrane separation component is connected to the catalytic dehydrogenation reactor, the outlet of the adsorption dryer is connected to the inlet of the crude helium compressor, and the outlet of the helium purifier is connected to the filling unit.

[0014] The room temperature pressure swing adsorption component is also connected to a natural gas compressor and a BOG compressor to realize the recycling of the desorption gas and the downstream gas generated by the room temperature pressure swing adsorption component.

[0015] Furthermore, a shut-off valve is provided between the crude helium extraction unit, the catalytic dehydrogenation unit, the helium refining unit and the filling unit for isolation, and a safety discharge pipeline is provided for venting.

[0016] Furthermore, there are at least two helium purifiers, one for purification and the other for activation and regeneration.

[0017] A crude helium refining method comprises the following steps:

[0018] S1, BOG raw gas enters the crude helium extraction unit through the air inlet pipeline, and is separated by the room temperature pressure swing adsorption coupled membrane to obtain crude helium after treatment by the crude helium extraction unit;

[0019] S2. The crude helium treated in the crude helium extraction unit is input into the catalytic dehydrogenation unit for dehydrogenation to obtain dehydrogenated crude helium;

[0020] S3. The crude helium after dehydrogenation is input into the helium refining unit, pressurized by the crude helium compressor and then enters the helium purifier to complete the refining and then sent to the filling unit for filling.

[0021] Furthermore, a crude helium refining method specifically comprises the following steps:

[0022] S1.1. BOG feed gas enters the crude helium extraction unit through the air inlet pipeline and passes through the room temperature pressure swing adsorption module to produce crude helium products, desorption gas, and effluent gas. The desorption gas returns to the natural gas compressor and is delivered to the fuel gas pipeline network. The effluent gas is recovered and liquefied by the BOG compressor. The crude helium product passes through the membrane separation module to obtain the crude helium processed by the crude helium extraction unit.

[0023] S2.1. The crude helium treated in the crude helium extraction unit is fed to a catalytic dehydrogenation unit. The catalytic dehydrogenation reactor in the catalytic dehydrogenation unit removes hydrogen from the permeate gas of the membrane separation module to below 1 ppm. The permeate gas is cooled in a water cooler to obtain condensed liquid water. The condensed liquid water is then separated in a gas-liquid separator. The permeate gas then enters an adsorption dryer to remove water from the permeate gas of the membrane separation module to below 3 ppm, yielding dehydrogenated crude helium.

[0024] S3.1. The crude helium after dehydrogenation is input into the helium refining unit, pressurized to 20 MPa by the crude helium compressor, and then enters the helium purifier for refining. The refined helium with a purity of more than 99.999% is sent to the filling unit. The helium with a purity lower than 99.999% is depressurized and returned to the crude helium compressor for further purification.

[0025] Furthermore, in step S1.1, the room temperature pressure swing adsorption assembly is filled with an adsorbent.

[0026] Furthermore, the adsorbent is a molecular sieve adsorbent.

[0027] Furthermore, the molecular sieve adsorbent includes but is not limited to silicon molecular sieve adsorbent, carbon molecular sieve adsorbent, and zeolite molecular sieve adsorbent.

[0028] Furthermore, in step S2.1, the catalytic dehydrogenation reactor is filled with a catalyst; and the adsorption dryer is filled with a molecular sieve adsorbent.

[0029] Furthermore, the catalyst includes but is not limited to palladium catalyst and platinum catalyst.

[0030] Furthermore, the molecular sieve adsorbent includes but is not limited to silicon molecular sieve adsorbent, carbon molecular sieve adsorbent, and zeolite molecular sieve adsorbent.

[0031] The beneficial effects of the present invention are as follows:

[0032] (1) The present invention obtains more than 95% of hydrogen and helium mixed gas through the crude helium extraction unit, reduces the hydrogen content to less than 1 ppm through the catalytic dehydrogenation unit, and further purifies the helium to high-purity helium that meets the requirements of GB / T4844 through the helium refining unit.

[0033] (2) The crude helium extraction unit of the present invention adopts room temperature pressure swing adsorption and membrane separation coupling method to extract helium, which can achieve crude helium extraction at room temperature without the need for a refrigerator, has low energy consumption, is stable and reliable, and is easy to operate.

[0034] (3) The present invention effectively recycles and utilizes the desorption gas and the downstream gas generated by the room temperature pressure swing adsorption assembly, realizes the secondary recovery of methane-rich gas and improves the recovery rate of helium.

[0035] (4) The present invention provides a dirty gas repurification pipeline interface, which decompresses the low-purity helium and returns it to the inlet of the crude helium compressor of the helium refining unit for re-purification, thereby improving the recovered purity of the helium. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solution of the present invention, the following briefly introduces the drawings required for use in the embodiments. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0037] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0038] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with specific embodiments of the present invention and corresponding drawings. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention. The technical solutions provided by each embodiment of the present invention are described in detail below in conjunction with the drawings.

[0039] Example 1

[0040] like Figure 1 As shown, a crude helium refining device can be divided into a crude helium extraction unit, a catalytic dehydrogenation unit, a helium refining unit and a filling unit according to the functional unit modules. Taking into account that the system may have equipment failures, unit shutdowns and interlocked shutdowns during operation, shut-off valves are provided between the crude helium extraction unit, the catalytic dehydrogenation unit, the helium refining unit and the filling unit for isolation, and a safety discharge pipeline is provided for venting treatment.

[0041] 1. Crude helium extraction unit

[0042] The crude helium extraction unit comprises a room temperature pressure swing adsorption component and a membrane separation component connected in sequence; crude helium treated by the crude helium extraction unit is obtained through room temperature pressure swing adsorption coupled with multi-stage membrane separation.

[0043] The crude helium extraction unit utilizes the different molecular polarities and particle sizes of different components of the mixed gas to separate helium, hydrogen, methane and nitrogen, thereby obtaining gas of the required purity.

[0044] The fully automatic control system applies a cycle of pressurized adsorption, normal pressure or reduced pressure analysis under room temperature conditions according to a specific programmable sequence, and separates and discharges impurities through membrane separation components to obtain exhaust gas of the required purity.

[0045] The room temperature pressure swing adsorption module is also connected to a natural gas compressor and a BOG compressor. The room temperature pressure swing adsorption module produces crude helium products, desorption gas, and effluent gas. The desorption gas returns to the natural gas compressor and is sent to the fuel gas pipeline network. The effluent gas is recovered and liquefied by the BOG compressor. The crude helium product passes through the membrane separation module to obtain crude helium after treatment in the crude helium extraction unit.

[0046] 2. Catalytic dehydrogenation unit

[0047] The catalytic dehydrogenation unit includes a catalytic dehydrogenation reactor, a water cooler, a gas-liquid separator, an adsorption dryer, a circulating compressor, a flow meter, and a hydrogen analyzer. The catalytic dehydrogenation unit consists of an inner and outer shell. The circulating compressor is located outside the shell, while the catalytic dehydrogenation reactor, water cooler, gas-liquid separator, and adsorption dryer are located inside the shell. The flow meter and hydrogen analyzer are installed on the inlet and outlet pipes of the catalytic dehydrogenation unit, respectively. The circulating compressor increases the gas pressure, forming a circulating gas flow in the system, which is controlled by the control system and measured by the flow meter.

[0048] The permeate gas outlet of the membrane separation component is connected to the catalytic dehydrogenation reactor. The catalytic dehydrogenation reactor is filled with a catalyst for removing hydrogen from the crude helium. The reaction temperature of the catalytic reactor is precisely controlled. The crude helium treated by the crude helium extraction unit is input into the catalytic dehydrogenation unit for oxygenation and catalytic dehydrogenation with oxygen from the liquid oxygen storage tank. The crude helium exiting the catalytic dehydrogenation reactor contains a large amount of reaction water. It is first cooled by a water cooler, and then the condensed liquid water is separated by a gas-liquid separator before entering the switching adsorption dryer. Since the adsorption dryer is filled with molecular sieve adsorbent, water in the feed gas can be removed. After the molecular sieve adsorbent is saturated with adsorption, it is heated and regenerated to restore its adsorption activity. The two adsorption dryers are switched and alternately adsorbed and regenerated, thereby achieving continuous drying of the crude helium exiting the catalytic dehydrogenation reactor, and the dehydrogenated crude helium is obtained at this time.

[0049] 3. Helium refining unit

[0050] The helium refining unit comprises a crude helium compressor and a helium purifier which are connected in sequence; the outlet of the adsorption dryer of the catalytic dehydrogenation unit is connected to the inlet of the crude helium compressor.

[0051] The crude helium after dehydrogenation is increased to a predetermined pressure by the crude helium compressor and then enters the helium purifier. After low-temperature condensation, separation and adsorption, high-purity helium of more than 99.999% is obtained and sent to the filling unit for filling; the helium whose purity does not reach more than 99.999% is returned to the inlet of the crude helium compressor after decompression for further purification.

[0052] There are at least two helium purifiers. In this embodiment, two helium purifiers are configured (one for use and one for backup), one of which performs purification work and the other performs activation and regeneration. The continuous working capacity of a single helium purifier is greater than 20 hours.

[0053] The helium purifier is a Dewar-type purifier, operating on the principle of high-pressure, low-temperature condensation separation and adsorption purification. The process operates at a liquid nitrogen temperature of 77K (-196°C). The unpurified helium entering the helium purifier and the purified helium leaving the purifier undergo countercurrent heat exchange in a high-pressure shell-and-tube heat exchanger to minimize liquid nitrogen loss during operation. The high-pressure, unpurified gas exiting the high-pressure shell-and-tube heat exchanger is slightly higher than the liquid nitrogen temperature, typically by about 10 to 13K. Therefore, it is further cooled in a subcooling heat exchanger immersed in liquid nitrogen, bringing its temperature closer to the liquid nitrogen temperature, thereby precipitating some impurities. Under high pressure and low temperature, when the unpurified helium enters the liquid separation cylinder of the helium purifier, the impurities contained therein, due to their boiling points exceeding the liquid nitrogen temperature, are supercooled and saturated, precipitating and accumulating at the bottom of the liquid separation cylinder. They are then discharged into the atmosphere through the discharge valve of the high-pressure, low-temperature pneumatic valve. Finally, it enters the low-temperature adsorption cylinder of the helium purifier, which is filled with activated carbon and molecular sieves. The adsorption characteristics of activated carbon and molecular sieves in a low-temperature environment (liquid nitrogen 77K) are used to adsorb the remaining impurity components, so that the purity of the helium is increased to 99.999% and then stored under high pressure.

[0054] A differential pressure level gauge is installed in the middle of the helium purifier Dewar. During the pre-cooling stage of the helium purifier, when the level gauge detects that the liquid level is ≥L+0.1m, the liquid nitrogen filling valve will be automatically closed. When the pressure drops to Lm, the liquid nitrogen filling valve will be automatically opened to start filling liquid nitrogen.

[0055] During the operation of the helium purifier, if the purity is detected to be less than 99.999%, the pure gas valve is closed and the dirty gas valve is opened, and the dirty gas returns to the dirty gas storage tank.

[0056] When the helium purifier is performing purification work, when the purity of the helium purifier outlet reaches above 99.999% and remains stable for 15 seconds, the pure gas valve is opened and the dirty gas valve is closed, and the purifier outputs high-purity helium.

[0057] When starting the electric heating activation regeneration, if the thermometer in the middle of the purifier detects that the temperature has reached the set temperature, the electric heating will be automatically turned off, and will be automatically turned on again after the temperature drops.

[0058] When the helium purifier is operating stably, the liquid nitrogen vacuum is used to control the opening of the vacuum pump inlet proportional valve, thereby maintaining a stable vacuum in the dewar. During pre-cooling of the helium purifier, nitrogen is directly vented through the bypass valve. The dewar is also equipped with safety valves and other safety accessories to ensure overpressure relief.

[0059] During activation and regeneration of the helium purifier, a hot nitrogen purge and vacuum treatment is used. After the purifier is depressurized to ambient pressure, it is purged with hot nitrogen. After the purge is complete, the nitrogen purge valve is closed. Once the purifier returns to ambient pressure, the vacuum pump is activated to evacuate and replace the purifier. The equipment uses a single activation vacuum pump, and the evacuation cycle is approximately three times. A small amount of high-purity helium is used to backfill the purifier to a slightly positive pressure after each evacuation. The equipment is equipped with a nitrogen heater, and the inner wall temperature of the nitrogen heater is controlled to below 120°C.

[0060] 4. Filling unit

[0061] The maximum outlet pressure of the helium refining unit is 20MPa. The high-purity helium obtained from the helium purifier first enters the on-site high-pressure buffer cylinder group. When the helium container tube bundle truck enters the factory, the high-pressure buffer cylinder group first inflates the helium container tube bundle truck, and then the helium refining unit boosts the pressure until it reaches the pressure of the helium container tube bundle truck.

[0062] The high-purity helium filling unit features a pre-installed bulk gas cylinder filling port for convenient recharging. Additionally, a vacuum pump facilitates evacuation and replacement of the helium manifolds in the event of contamination. Industry practice requires online monitoring of oxygen and water content during product delivery to ensure compliance with national standards.

[0063] Example 2

[0064] This embodiment takes BOG raw gas (based on V / V, the composition is: HE 3.50%, H 2 1.70%, N 2 15.30%, CH 4 79.50%, O 20%, H 2 O 0%) as an example to perform helium refining. The refining process is as follows:

[0065] (1) BOG raw gas enters the crude helium extraction unit through the air inlet pipeline, and is processed by the room temperature pressure swing adsorption component to produce product crude helium, desorption gas and effluent gas; the desorption gas returns to the natural gas compressor and is sent to the fuel gas pipeline network, and the effluent gas is recovered and liquefied by the BOG compressor, and the product crude helium passes through the membrane separation component to obtain the crude helium processed by the crude helium extraction unit.

[0066] The room-temperature pressure swing adsorption module uses the equilibrium adsorption capacity of the adsorbent to perform pressurized adsorption and atmospheric or reduced pressure desorption at room temperature. The membrane separation module separates gas components based on their transport and permeation rates. The crude helium treated by the crude helium extraction unit has a helium and hydrogen purity of 95% (on a V / V basis, the composition is: HE 63.94%, H2 31.06%, N2 0.81%, CH4 4.19%, O 20%, H2O 0%).

[0067] (2) The catalytic dehydrogenation reactor of the catalytic dehydrogenation unit is filled with a catalyst, and the crude helium treated by the crude helium extraction unit is input into the catalytic dehydrogenation unit to remove hydrogen from the crude helium to less than 1 ppm, and then cooled by a water cooler to obtain condensed liquid water, which is then separated by a gas-liquid separator and then enters an adsorption dryer to remove water from the permeate gas of the membrane separation module to less than 3 ppm, thereby obtaining dehydrogenated crude helium;

[0068] (3) The crude helium after dehydrogenation is input into the helium refining unit, pressurized to 20 MPa by the crude helium compressor and then enters the helium purifier for refining. The refined helium with a purity of more than 99.999% is sent to the filling unit for filling.

[0069] Comparative Example 1

[0070] This embodiment takes BOG raw gas (based on V / V, the composition is: HE 3.50%, H 2 1.70%, N 2 15.30%, CH 4 79.50%, O 20%, H 2 O 0%) as an example to perform helium refining. The refining process is as follows:

[0071] (1) BOG raw gas enters the crude helium extraction unit through the air inlet pipe, and produces product crude helium, desorption gas and downstream gas through the room temperature pressure swing adsorption component. The product crude helium directly enters the catalytic dehydrogenation unit. At this time, the purity of helium and hydrogen in the crude helium is 51% (based on V / V, the composition is: HE 34.04%, H2 16.53%, N2 7.98%, CH4 41.45%, O 20%, H2O 0%).

[0072] (2) The catalytic dehydrogenation reactor of the catalytic dehydrogenation unit is filled with a catalyst, and the crude helium treated by the crude helium extraction unit is input into the catalytic dehydrogenation unit to dehydrogenate the hydrogen in the crude helium. The crude helium is cooled by a water cooler to obtain condensed liquid water, which is then separated by a gas-liquid separator and then enters an adsorption dryer to remove water from the permeate gas of the membrane separation module to below 3 ppm, thereby obtaining dehydrogenated crude helium;

[0073] (3) The crude helium after dehydrogenation is input into the helium refining unit, pressurized to 20 MPa by the crude helium compressor and then enters the helium purifier for refining. The purity after refining does not meet the requirements of GB / T4844.

[0074] Comparative Example 2

[0075] This embodiment takes BOG raw gas (based on V / V, the composition is: HE 3.50%, H 2 1.70%, N 2 15.30%, CH 4 79.50%, O 20%, H 2 O 0%) as an example to perform helium refining. The refining process is as follows:

[0076] (1) BOG raw gas enters the crude helium extraction unit through the air inlet pipe, and directly enters the membrane separation component without passing through the room temperature pressure swing adsorption component. The permeate gas separated by the membrane enters the catalytic dehydrogenation unit. At this time, the purity of helium and hydrogen in the crude helium is 51% (based on V / V, the composition is: HE 29.90%, H2 14.53%, N2 0.09%, CH4 55.48%, O 20%, H2O 0%).

[0077] (2) The catalytic dehydrogenation reactor of the catalytic dehydrogenation unit is filled with a catalyst, and the crude helium treated by the crude helium extraction unit is input into the catalytic dehydrogenation unit to remove hydrogen from the crude helium. The crude helium is cooled by a water cooler to obtain condensed liquid water, which is then separated by a gas-liquid separator and then enters an adsorption dryer to remove water from the permeate gas of the membrane separation module to below 3 ppm, thereby obtaining dehydrogenated crude helium;

[0078] (3) The crude helium after dehydrogenation is input into the helium refining unit, pressurized to 20 MPa by the crude helium compressor and then enters the helium purifier for refining. The purity after refining does not meet the requirements of GB / T4844.

Claims

1. A crude helium refining device, characterized in that: include: The crude helium extraction unit comprises a room temperature pressure swing adsorption component and a membrane separation component connected in sequence; the room temperature pressure swing adsorption component is also connected to a natural gas compressor and a BOG compressor; The catalytic dehydrogenation unit includes a catalytic dehydrogenation reactor, a water cooler, a gas-liquid separator, an adsorption dryer, a circulating compressor, a flow meter, and a hydrogen analyzer; the flow meter and the hydrogen analyzer are respectively arranged on the air inlet pipe and the air outlet pipe of the catalytic dehydrogenation unit; The helium refining unit comprises a crude helium compressor and a helium purifier connected in sequence; the crude helium compressor is also connected to a dirty gas repurification pipeline interface; and Filling unit; Wherein, the crude helium extraction unit, catalytic dehydrogenation unit, helium refining unit and filling unit are connected in sequence through pipelines; The permeate gas outlet of the membrane separation component is connected to the catalytic dehydrogenation reactor, the outlet of the adsorption dryer is connected to the inlet of the crude helium compressor, and the outlet of the helium purifier is connected to the filling unit.

2. The crude helium refining device according to claim 1, characterized in that: The crude helium extraction unit, catalytic dehydrogenation unit, helium refining unit and filling unit are provided with cut-off valves for isolation, and a safety discharge pipeline is also provided for venting treatment.

3. A crude helium refining method, characterized in that: The following steps are involved: S1, BOG raw gas enters the crude helium extraction unit through the air inlet pipeline, and is separated by the room temperature pressure swing adsorption coupled membrane to obtain crude helium after treatment by the crude helium extraction unit; S2. The crude helium treated in the crude helium extraction unit is input into the catalytic dehydrogenation unit for dehydrogenation to obtain dehydrogenated crude helium; S3. The crude helium after dehydrogenation is input into the helium refining unit, pressurized by the crude helium compressor and then enters the helium purifier to complete the refining and then sent to the filling unit for filling.

4. The crude helium purification method according to claim 3, characterized in that: The specific steps include: S1.

1. BOG feed gas enters the crude helium extraction unit through the air inlet pipeline and passes through the room temperature pressure swing adsorption component to produce crude helium products, desorption gas, and effluent gas. The desorption gas returns to the natural gas compressor and is sent to the fuel gas pipeline network. The effluent gas is recovered and liquefied by the BOG compressor. The crude helium product passes through the membrane separation component to obtain crude helium processed by the crude helium extraction unit. S2.

1. The crude helium treated in the crude helium extraction unit is fed into the catalytic dehydrogenation unit. The catalytic dehydrogenation reactor in the catalytic dehydrogenation unit removes hydrogen from the permeate gas of the membrane separation module to a predetermined concentration. The permeate gas is cooled in a water cooler to obtain condensed liquid water. The condensed liquid water is then separated in a gas-liquid separator. The permeate gas then enters an adsorption dryer to remove water from the permeate gas of the membrane separation module to a predetermined concentration, yielding dehydrogenated crude helium. S3.

1. The crude helium after dehydrogenation is input into the helium refining unit, pressurized by the crude helium compressor, and then enters the helium purifier for refining. The refined helium with a purity of more than 99.999% is sent to the filling unit. The helium with a purity lower than 99.999% is depressurized and returned to the crude helium compressor for further purification.

5. The crude helium refining method according to claim 4, characterized in that: In step S1.1, the purity of helium and hydrogen in the crude helium after being processed by the crude helium extraction unit is greater than 95%.

6. The crude helium purification method according to claim 4, characterized in that: In step S2.1, hydrogen in the permeate gas of the membrane separation assembly is removed to below 1 ppm through the catalytic dehydrogenation reactor of the catalytic dehydrogenation unit.

7. The crude helium purification method according to claim 4, characterized in that: In step S2.1, the permeate gas enters the adsorption dryer to remove water from the permeate gas of the membrane separation module to below 3 ppm.

8. The crude helium purification method according to claim 4, characterized in that: In step S3.1, the crude helium is pressurized to 20 MPa by the crude helium compressor and then enters the helium purifier for refining.

9. The crude helium purification method according to claim 4, characterized in that: The room temperature pressure swing adsorption component, the catalytic dehydrogenation reactor and the adsorption dryer are respectively filled with adsorbent, catalyst and molecular sieve adsorbent.

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