Method and system for purifying crude helium based on relatively high hydrogen content

Abstract

The invention relates to the technical field of crude helium purification, and discloses a crude helium purification method and system based on high hydrogen content, the system comprises a first-stage adsorption unit, a second-stage adsorption unit and a regeneration unit, an adsorber in the first-stage adsorption unit is provided with a first-stage adsorbent, the first-stage adsorbent is selected from cocoanut active charcoal and a modified nano material, and the second-stage adsorption unit is provided with a second-stage adsorbent; the particle size of the coconut shell activated carbon is 4-6 mm, the aperture of the nano material is 0.3-0.8 nm, the temperature is controlled to be 80-110 K, and hydrogen, nitrogen and argon are adsorbed and removed; a second-stage adsorbent is arranged in a second-stage adsorber of the second-stage adsorption unit, the temperature is controlled to be 20-30 K, and modified coconut shell activated carbon is selected as the second-stage adsorbent to adsorb and remove neon; according to the system, the purification of crude helium is divided into two stages, only physical adsorption purification is carried out, the operation of the system is more stable, and the regeneration unit is used for carrying out heating vacuumizing replacement on a primary adsorbent or a secondary adsorbent; the system can circularly purify the crude helium, and the purity of the helium can reach 99.9999% or above.

Description

Technical Field

[0001] This invention relates to the field of gas purification technology, specifically to a method and system for purifying crude helium gas with a high hydrogen content. Background Technology

[0002] Natural gas is an important raw material for chemical production. When natural gas is used in chemical equipment, the waste gas exiting the equipment still contains a large amount of natural gas, as well as inert gases that do not participate in the reaction, such as helium, which is of significant value. Because helium is a strategic resource, helium extraction technology from chemical waste gas is constantly developing with technological advancements. Current technologies typically extract helium from chemical waste gas using methods such as pressure swing adsorption, cryogenic separation, and membrane separation. However, the helium extracted using these methods contains approximately 3-15% hydrogen, about 20 ppm neon, 2 ppm nitrogen, and 50 ppm argon.

[0003] Due to the high hydrogen content, if an oxygen-catalytic oxidation process is used, the oxygen and hydrogen will react chemically under high pressure, generating a large amount of heat and posing significant safety hazards. Currently, alloy adsorption processes are used to extract helium. While hydrogen readily chemically adsorbs onto the alloy, reusing the adsorbent requires desorption, which necessitates high temperatures. Furthermore, alloy adsorbents have a short lifespan; their adsorption capacity decreases after a period of use, leading to high repurchase costs. Therefore, there is an urgent need for a low-cost, high-efficiency method to purify helium with a high hydrogen content (greater than 3% of the total). Summary of the Invention

[0004] The present invention aims to provide a method and system for purifying crude helium with a high hydrogen content, in order to solve the problem of low purification efficiency of helium with a high hydrogen content.

[0005] To achieve the above objectives, the present invention first provides a crude helium purification system based on a high hydrogen content, comprising a primary adsorption unit, a secondary adsorption unit, and a regeneration unit. The primary adsorption unit includes a primary heat exchanger and a primary adsorber. Both the primary heat exchanger and the primary adsorber include a raw material layer and a heat exchange layer. The raw material layer of the primary heat exchanger and the raw material layer of the primary adsorber are connected. Both the primary heat exchanger and the primary adsorber are connected to a cold source with a temperature of 80~110K. The secondary adsorption unit includes a refrigerator and a secondary adsorber. The secondary adsorber also includes a raw material layer and a heat exchange layer. The refrigerator is connected between the raw material layer of the primary adsorber and the raw material layer of the secondary adsorber. The refrigerator cools the crude helium gas after the first adsorption to 20~30K. The primary adsorbent is laid in the raw material layer of the primary adsorbent, which includes a coconut shell activated carbon layer and a modified nanomaterial layer. The coconut shell activated carbon in the coconut shell activated carbon layer has a particle size of 4-6 mm, and the nanomaterial layer has a pore size of 0.3-0.8 nm. The secondary adsorbent is a modified coconut shell activated carbon, which contains boron and trivalent titanium ions. The regeneration unit includes an electric heater and a vacuum pump. The electric heater heats nitrogen to 50-100°C and then introduces it into the heat exchange layer of the primary adsorbent. High-purity helium gas heated to 20-30°C is introduced into the heat exchange layer of the secondary adsorbent. The raw material layer of the primary or secondary adsorbent is connected to the vacuum pump, which continuously evacuates and replaces the adsorbed primary or secondary adsorbent.

[0006] This system has the following advantages in the purification process of crude helium: The hydrogen adsorption process is highly exothermic, which can cause the bed temperature to rise and lead to a decrease in the purity of the helium product. Therefore, this system divides the purification of crude helium into two stages to avoid temperature fluctuations in the cryogenic region. Both stages are physical adsorption processes without chemical reactions, making the entire device more stable in operation.

[0007] The first stage focuses on removing the high concentration of hydrogen, along with nitrogen and argon. In this stage, the temperature is lowered to 80-110K to activate the primary adsorbent, maximizing its adsorption capacity. The primary adsorbent contains modified nanomaterials with pore sizes of 0.3-0.8 nm to match the diameter of hydrogen molecules, avoiding interference from helium and nitrogen, and thus improving the hydrogen adsorption rate. Compared to alloy materials, modified nanomaterials have a longer service life and offer higher cost-effectiveness.

[0008] The second stage involves adsorbing neon gas separately. Because the concentration of neon gas is low, less heat is released during the adsorption process, which is less likely to cause large fluctuations in the bed temperature. However, neon gas requires a lower temperature to activate its removal. Therefore, the system uses heat exchange to reduce the neon gas adsorption temperature by 20-30K.

[0009] Furthermore, the primary adsorber is connected in parallel with a second primary adsorber, which shares the same piping as the primary adsorber, forming a dual-tower system. This allows the primary and secondary adsorbers to operate alternately. Similarly, the secondary adsorber is connected in parallel with a second secondary adsorber, which also shares the same piping as the primary adsorber, forming a dual-tower system. This allows the secondary adsorbers to operate alternately. This design ensures that the regeneration process does not require stopping the purification equipment, enabling continuous purification.

[0010] Furthermore, the crude helium purification system also includes a cold energy recovery path for recovering the cold energy of the purified helium. This cold energy recovery path includes a secondary heat exchanger and the primary heat exchanger. The primary heat exchanger further includes a second heat exchange layer. The secondary heat exchanger includes a raw material layer and a heat exchange layer. The raw material layer of the secondary heat exchanger is connected to the raw material layer outlet of the primary adsorber. The purified helium output from the secondary adsorber is sequentially fed into the heat exchange layer of the secondary heat exchanger and then the second heat exchange layer of the primary heat exchanger via pipelines. This cold energy recovery effectively improves resource utilization and reduces energy consumption.

[0011] Furthermore, the crude helium purification system also includes a helium return path, which includes a return branch pipe from the outlet of the second heat exchange layer of the primary heat exchanger. The return branch pipe is connected to the heat exchange layer of the secondary adsorber, and is used to introduce high-purity helium gas heated to 20°C~30°C into the heat exchange layer of the secondary adsorber. The high-purity helium gas at 20°C~30°C provides regeneration heat for the secondary adsorbent.

[0012] Furthermore, the crude helium purification system also includes a circulation path, which consists of circulation pipes connected to the feed layer outlet of the primary heat exchanger and respectively connected to the feed layer of the primary or secondary adsorber. This circulation path is used to fill the spaces containing the regenerated primary and secondary adsorbents with pure helium, ensuring that the primary and secondary adsorbents maintain their maximum adsorption capacity.

[0013] Furthermore, both the primary and secondary adsorbers are double-layered, barrel-shaped adsorption towers. The raw material layer is located in the inner layer of the adsorption tower, which is equipped with multiple rows of cold-rolled tubes that communicate with the outer layer. The coconut shell activated carbon layer and the modified nanomaterial layer in the primary adsorbent are alternately laid between the multiple rows of cold-rolled tubes. The multiple rows of cold-rolled tubes enable rapid heat exchange with the adsorbent, ensuring that the adsorbent remains stable within the set temperature environment.

[0014] To achieve the above objectives, the present invention provides a method for purifying crude helium gas with a high hydrogen content, based on the aforementioned crude helium gas purification system, comprising the following steps: S1: First cooling of crude helium gas. The crude helium gas is introduced into the first-stage heat exchanger, and a cold source is introduced into the first-stage heat exchanger to cool the crude helium gas to 80~110K. S2: Crude helium gas cooled to 80~110K is introduced into the first adsorber, which is filled with a first adsorbent. The first adsorbent is composed of coconut shell activated carbon and modified nanomaterials. The coconut shell activated carbon has a particle size of 4~6mm, and the nanomaterials have a pore size of 0.3~0.8nm. The coconut shell activated carbon in the first adsorbent adsorbs trace amounts of nitrogen and argon, while the nanomaterials adsorb hydrogen. S3: Cool the crude helium gas output from the first adsorber again to a temperature of 20~30K; S4: Crude helium gas, cooled to 20-30K, is introduced into a secondary adsorber. The secondary adsorber contains a secondary adsorbent, which is modified coconut shell activated carbon. The modified coconut shell activated carbon also contains boron and trivalent titanium ions. The neon gas in the crude helium gas is adsorbed and removed by the secondary adsorbent, and the gas exiting the secondary adsorber is helium gas with a purity of over 99.9999%.

[0015] Furthermore, between steps S3 and S4, the process also includes recovering the cold energy of purified helium gas below 80K. The purified helium gas output from the secondary adsorber passes sequentially through the second heat exchanger and the first heat exchanger to complete the recovery of the cold energy of purified helium gas below 80K.

[0016] Furthermore, the modified coconut shell activated carbon in step S4 undergoes the following modification treatment: S41: Carbonize the coconut shell at 650~750℃ for 2~3 hours to remove volatile matter; S42: Activated with water vapor at 850~950℃ for 4~5 hours to form a rich microporous structure; S43: In neon gas, at 700℃ for 2 hours, surface oxygen-containing groups are removed and polarity is reduced to obtain modified coconut shell activated carbon; S44: Add boron and trivalent titanium ions and mix them in modified coconut shell activated carbon.

[0017] Furthermore, it also includes periodic regeneration of the primary and secondary adsorbents. Since both the primary and secondary adsorbents employ a dual-tower system, the regeneration process includes: A1: When the adsorption saturation rate of the primary or secondary adsorbent in one of the adsorption pathways exceeds 80%, the current adsorption pathway is closed, and another adsorption pathway is started simultaneously to carry out adsorption continuously.

[0018] A2. Hot nitrogen gas at 50~100℃ is introduced into the heat exchange layer of the regenerated primary adsorber, and high-purity helium gas at 20℃~30℃ is introduced into the heat exchange layer of the secondary adsorber, raising the temperature of the space where the primary adsorbent is located to above 220K and the temperature of the space where the secondary adsorbent is located to above 100K.

[0019] A3: For the regeneration of the primary adsorbent, when the temperature of the space containing the primary adsorbent reaches above 220K and the pressure is less than 25kPa.G, turn on the vacuum pump to evacuate the space and allow the hydrogen, argon, and nitrogen adsorbed on the primary adsorbent to desorb. For the regeneration of the secondary adsorbent, when the temperature of the space containing the secondary adsorbent reaches 100K and the pressure is less than 25kPa.G, turn on the vacuum pump to evacuate the space and allow the neon in the secondary adsorbent to desorb.

[0020] The space containing the primary or secondary adsorbent is continuously vacuumed by a vacuum pump, causing the hydrogen, argon, and nitrogen adsorbed in the primary adsorbent to desorb, or the neon in the secondary adsorbent to desorb.

[0021] A4: The adsorber is continuously depressurized. When the adsorber pressure reaches 200Pa, one regeneration and desorption is completed. Then, room temperature high-purity helium is injected into the inner layer of the adsorber until it reaches atmospheric pressure. Then, the vacuum pump is turned on again.

[0022] After three vacuum suction cycles, hydrogen, argon, and nitrogen in the primary adsorbent are completely desorbed; or neon in the secondary adsorbent is completely desorbed.

[0023] A5: High-purity helium is introduced into the raw material layer of the regenerated primary or secondary adsorber. The internal temperature of the primary or secondary adsorber is cooled by heat exchange, and helium is replenished in real time to keep the pressure of the raw material layer of the primary or secondary adsorber at normal pressure. The primary or secondary adsorbent re-enters the state of maximum adsorption capacity, ready for use in the next switching of the process.

[0024] Furthermore, in step A3, during the desorption of neon from the secondary adsorbent, a neon collection tank is added to the vacuum pump to recover the neon. This neon recovery process only regenerates the secondary adsorbent. In this way, the valuable resource of neon is recovered and utilized. Attached Figure Description

[0025] Figure 1 Schematic diagram of a crude helium purification system with high hydrogen content.

[0026] Figure 2 This is a flowchart illustrating the steps involved in the crude helium purification method.

[0027] Figure 3 This is a flowchart illustrating the processing steps of modified coconut shell activated carbon in an embodiment of the present invention.

[0028] Figure 4 This is a flowchart illustrating the steps of the regeneration process according to an embodiment of the present invention.

[0029] The reference numerals in the accompanying drawings include: 1. Primary heat exchanger; 2. Primary adsorber; 3. Secondary heat exchanger; 4. Refrigeration unit; 5. Secondary adsorber; 6. Vacuum pump; 7. Electric heater. Detailed Implementation

[0030] The following detailed description illustrates the specific implementation method: The basic implementation examples are as follows: Figure 1 The crude helium purification system shown has a high hydrogen content and includes a primary adsorption unit, a secondary adsorption unit, and a regeneration unit.

[0031] The primary adsorption unit includes a primary heat exchanger 1 and a primary adsorber 2. Both primary heat exchanger 1 and primary adsorber 2 include a raw material layer and a heat exchange layer. The raw material layer of primary heat exchanger 1 and the raw material layer of primary adsorber 2 are connected. The heat exchange layers of primary heat exchanger 1 and primary adsorber 2 are connected to liquid nitrogen at a temperature of 80K.

[0032] The secondary adsorption unit includes a refrigerator 4 and a secondary adsorber 5. The secondary adsorber 5 also includes a raw material layer and a heat exchange layer. The refrigerator 4 is connected between the raw material layer of the primary adsorber 2 and the raw material layer of the secondary adsorber 5. The refrigerator 4 cools the crude helium gas after the first adsorption to 30K.

[0033] The primary adsorbent is laid in the raw material layer of the primary adsorber 2. The primary adsorbent includes a coconut shell activated carbon layer and a modified nanomaterial layer. The coconut shell activated carbon in the coconut shell activated carbon layer has a particle size of 4~6mm, and the nanomaterial layer has a pore size of 0.3~0.8nm.

[0034] The secondary adsorbent 5 is laid in the raw material layer. The secondary adsorbent is modified coconut shell activated carbon, in which boron and trivalent titanium ions are added.

[0035] The regeneration unit includes an electric heater 7 and a vacuum pump 6. The electric heater 7 heats nitrogen to 50℃~100℃ and then introduces it into the heat exchange layer of the primary adsorber 2. High-purity helium gas at room temperature of 20℃~30℃ is introduced into the heat exchange layer of the secondary adsorber. The raw material layer of the primary adsorber 2 or the raw material layer of the secondary adsorber 5 is connected to the vacuum pump 6. The vacuum pump 6 continuously evacuates and replaces the adsorbed primary or secondary adsorbent.

[0036] The primary adsorber is connected in parallel with a secondary adsorber, which shares the same piping as the primary adsorber, forming a dual-tower system. This allows the primary and secondary adsorbers to operate alternately. Similarly, the secondary adsorber is connected in parallel with a secondary adsorber, which also shares the same piping, forming a dual-tower system. This allows the secondary adsorber to operate alternately. This design ensures that the regeneration process does not require stopping the purification equipment, allowing for continuous purification.

[0037] The system includes a cold energy recovery pathway for recovering the cold energy of purified helium. This pathway comprises a secondary heat exchanger 3 and a primary heat exchanger 1. The primary heat exchanger 1 also includes a second heat exchange layer. The secondary heat exchanger 3 includes a feed layer and a heat exchange layer. The feed layer of the secondary heat exchanger 3 is connected to the feed layer outlet of the primary adsorber 1. Purified helium output from the secondary adsorber 5 is sequentially fed through pipes to the heat exchange layer of the secondary heat exchanger 3 and then to the second heat exchange layer of the primary heat exchanger 1. This cold energy recovery effectively improves resource utilization and reduces energy consumption.

[0038] The system also includes a helium return path, which includes a return branch pipe connected to the outlet of the second heat exchange layer of the primary heat exchanger 1. The return branch pipe is connected to the heat exchange layer of the secondary adsorber 5 and is used to introduce high-purity helium gas heated to 20℃~30℃ into the heat exchange layer of the secondary adsorber. The high-purity helium gas provides regeneration heat for the secondary adsorbent.

[0039] The system includes a circulation path for filling the primary adsorber 2 or the secondary adsorber 5 with pure helium. The circulation path introduces pure helium output from the primary heat exchanger 1 into the feed layer of the primary adsorber 2 or the secondary adsorber 5, maintaining the primary and secondary adsorbents at their maximum adsorption capacity.

[0040] Both the primary adsorber 2 and the secondary adsorber 5 are double-layered, barrel-shaped adsorption towers. The raw material layer is located in the inner layer of the adsorption tower, which is connected to the outer layer by multiple rows of cold-rolled tubes. The coconut shell activated carbon layer and the modified nanomaterial layer in the primary adsorbent are alternately laid between the multiple rows of cold-rolled tubes. The multiple rows of cold-rolled tubes can quickly exchange heat with the adsorbent, ensuring that the adsorbent can remain stable within the set temperature environment.

[0041] like Figure 2 As shown, the specific implementation process of the crude helium purification method is as follows: S1: First cooling of crude helium gas. The crude helium gas is connected to the first-stage heat exchanger, and a cold source is introduced into the first-stage heat exchanger to cool the crude helium gas to 80K.

[0042] S2: Crude helium gas cooled to 80K is introduced into the first adsorber, which is filled with a first adsorbent. The first adsorbent is composed of coconut shell activated carbon and modified nanomaterials. The coconut shell activated carbon has a particle size of 4~6mm and the nanomaterials have a pore size of 0.3~0.8nm. The coconut shell activated carbon in the first adsorbent adsorbs trace amounts of nitrogen and argon, while the nanomaterials adsorb hydrogen.

[0043] S3: The crude helium gas output from the first adsorber will be cooled again to 30K.

[0044] S4: Crude helium gas cooled to 30K is introduced into a secondary adsorber. The secondary adsorber contains a secondary adsorbent, which is modified coconut shell activated carbon. The modified coconut shell activated carbon also contains boron and trivalent titanium ions. The neon gas in the crude helium gas is adsorbed and removed by the secondary adsorbent, and the gas exiting the secondary adsorber is helium gas with a purity of over 99.9999%.

[0045] Between steps S3 and S4, the process also includes recovering the cold energy of purified helium gas below 30K. The purified helium gas output from the secondary adsorber passes through the second heat exchanger and the first heat exchanger in sequence to complete the recovery of the cold energy of purified helium gas below 30K.

[0046] like Figure 3 As shown, the modified coconut shell activated carbon underwent the following modification treatment: S41: Carbonize the coconut shell at 650~750℃ for 2~3 hours to remove volatile matter.

[0047] S42: Activated with water vapor at 850~950℃ for 4~5 hours to form a rich microporous structure.

[0048] S43: In neon gas, at 700℃ for 2 hours, surface oxygen-containing groups are removed and polarity is reduced to obtain modified coconut shell activated carbon.

[0049] S44: Add boron and trivalent titanium ions and mix them in modified coconut shell activated carbon.

[0050] like Figure 4 As shown, the primary and secondary adsorbents undergo regeneration treatment, which includes the following steps: A1: When the adsorption saturation rate of the primary or secondary adsorbent in one of the adsorption pathways exceeds 80%, the current adsorption pathway is closed, and another adsorption pathway is started simultaneously to carry out adsorption continuously.

[0051] A2. Hot nitrogen gas at 50~100℃ is introduced into the heat exchange layer of the regenerated primary adsorber, and high-purity helium gas at room temperature is introduced into the heat exchange layer of the secondary adsorber, raising the temperature of the space where the primary adsorbent is located to above 220K and the temperature of the space where the secondary adsorbent is located to above 100K.

[0052] A3: For the regeneration of the primary adsorbent, when the temperature of the space containing the primary adsorbent reaches above 220K and the pressure is less than 25kPa.G, turn on the vacuum pump to evacuate the space and allow the hydrogen, argon, and nitrogen adsorbed on the primary adsorbent to desorb. For the regeneration of the secondary adsorbent, when the temperature of the space containing the secondary adsorbent reaches 100K and the pressure is less than 25kPa.G, turn on the vacuum pump to evacuate the space and allow the neon in the secondary adsorbent to desorb.

[0053] During the desorption of neon from the secondary adsorbent, a neon collection tank is added to the vacuum pump to recover the neon. This neon recovery process only regenerates the secondary adsorbent. This allows for the recycling of the valuable neon resource.

[0054] A4: The adsorber is continuously depressurized. When the adsorber pressure reaches 200Pa, one regeneration and desorption is completed. High-purity helium at room temperature is injected into the inner layer of the adsorber and charged to atmospheric pressure. The vacuum pump is turned on again. After three vacuum suctions are completed, the hydrogen, argon and nitrogen in the primary adsorbent are completely desorbed. The neon in the secondary adsorbent is completely desorbed.

[0055] A5: High-purity helium is introduced into the raw material layer of the regenerated primary or secondary adsorber. The internal temperature of the primary or secondary adsorber is cooled by heat exchange, and helium is replenished in real time to keep the pressure of the raw material layer of the primary or secondary adsorber at normal pressure. The primary or secondary adsorbent re-enters the state of maximum adsorption capacity, ready for use in the next switching of the process.

[0056] During the regeneration process, the desorption of the primary adsorbent and the secondary adsorbent can be carried out simultaneously or separately.

[0057] The temperature conversions mentioned in the article are: 1 K (Kelvin) = -272.15℃ (Celsius), and the normal temperature mentioned in the article is 20℃~30℃.

[0058] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A purification system for crude helium gas with high hydrogen content, characterized in that: include, Primary adsorption unit, secondary adsorption unit, and regeneration unit; The primary adsorption unit includes a primary heat exchanger and a primary adsorber. Both the primary heat exchanger and the primary adsorber include a raw material layer and a heat exchange layer. The raw material layer of the primary heat exchanger and the raw material layer of the primary adsorber are connected. Both the primary heat exchanger and the primary adsorber are connected to a cold source with a temperature of 80~110K. The secondary adsorption unit includes a refrigerator and a secondary adsorber. The secondary adsorber also includes a raw material layer and a heat exchange layer. The refrigerator is connected between the raw material layer of the primary adsorber and the raw material layer of the secondary adsorber. The refrigerator cools the crude helium gas after the first adsorption to 20~30K. The primary adsorbent is laid in the raw material layer of the primary adsorbent, which includes a coconut shell activated carbon layer and a modified nanomaterial layer. The coconut shell activated carbon in the coconut shell activated carbon layer has a particle size of 4-6 mm, and the nanomaterial layer has a pore size of 0.3-0.8 nm. The secondary adsorbent is a modified coconut shell activated carbon, which contains boron and trivalent titanium ions. The regeneration unit includes an electric heater and a vacuum pump. The electric heater heats nitrogen to 50-100°C and then introduces it into the heat exchange layer of the primary adsorbent. High-purity helium gas heated to 20-30°C is introduced into the heat exchange layer of the secondary adsorbent. The raw material layer of the primary or secondary adsorbent is connected to the vacuum pump, which continuously evacuates and replaces the adsorbed primary or secondary adsorbent.

2. The crude helium purification system based on high hydrogen content according to claim 1, characterized in that: The primary adsorber is also connected in parallel with a second primary adsorber. The second primary adsorber has the same piping connection as the primary adsorber, forming a dual-tower system, allowing the primary and secondary adsorbers to operate alternately. The secondary adsorber is also connected in parallel with a second secondary adsorber. The second secondary adsorber has the same piping connection as the secondary adsorber, forming a dual-tower system, allowing the secondary adsorbers to operate alternately.

3. The crude helium purification system based on high hydrogen content according to claim 1, characterized in that: It also includes a cold energy recovery path for recovering the cold energy of purified helium. The cold energy recovery path includes a secondary heat exchanger and the primary heat exchanger. The primary heat exchanger also includes a second heat exchange layer. The secondary heat exchanger includes a raw material layer and a heat exchange layer. The raw material layer of the secondary heat exchanger is connected to the raw material layer outlet end of the primary adsorber. The purified helium output from the secondary adsorber is sequentially connected to the heat exchange layer of the secondary heat exchanger and the second heat exchange layer of the primary heat exchanger through pipelines.

4. The crude helium purification system based on high hydrogen content according to claim 3, characterized in that: It also includes a helium return path, which includes a return branch pipe from the outlet of the second heat exchange layer of the first heat exchanger. The return branch pipe is connected to the heat exchange layer of the second adsorber and is used to introduce high-purity helium gas heated to 20°C~30°C into the heat exchange layer of the second adsorber. The high-purity helium gas at 20°C~30°C provides regeneration heat for the second adsorbent.

5. The crude helium purification system based on high hydrogen content according to claim 1, characterized in that: It also includes a circulation path, which includes circulation pipes connected to the raw material layer outlet of the primary heat exchanger and to the raw material layer of the primary or secondary adsorber, respectively, for filling the space where the regenerated primary and secondary adsorbers are located with pure helium.

6. The crude helium purification system based on high hydrogen content according to claim 1, characterized in that: Both the primary and secondary adsorbers are double-layered barrel-shaped adsorption towers. The raw material layer of the adsorption tower is located in the inner layer of the adsorption tower. The inner layer of the adsorption tower is equipped with multiple rows of cold tubes, which are connected to the outer layer. The coconut shell activated carbon layer and the modified nanomaterial layer in the primary adsorbent are alternately laid between the multiple rows of cold tubes.

7. A method for purifying crude helium gas with a high hydrogen content, based on the crude helium gas purification system as described in any one of claims 1 to 5, characterized in that: Includes the following steps: S1: First cooling of crude helium gas. The crude helium gas is introduced into the first-stage heat exchanger, and a cold source is introduced into the first-stage heat exchanger to cool the crude helium gas to 80K~110K. S2: Crude helium gas cooled to 80K~110K is introduced into the first adsorber. The first adsorber is lined with a first adsorbent, which is composed of coconut shell activated carbon and modified nanomaterials. The coconut shell activated carbon has a particle size of 4~6mm, and the nanomaterials have a pore size of 0.3~0.8nm. The coconut shell activated carbon in the first adsorbent adsorbs trace amounts of nitrogen and argon, while the nanomaterials adsorb hydrogen. S3: Cool the crude helium gas output from the first adsorber again to a temperature of 20~30K; S4: Crude helium gas, cooled to 20-30K, is introduced into a secondary adsorber. The secondary adsorber contains a secondary adsorbent, which is modified coconut shell activated carbon. The modified coconut shell activated carbon also contains boron and trivalent titanium ions. The secondary adsorbent adsorbs and removes neon from the crude helium gas, and the gas exiting the secondary adsorber is helium gas with a purity of over 99.9999%.

8. The crude helium purification method according to claim 7, characterized in that: Between steps S3 and S4, the process also includes recovering the cold energy of purified helium gas below 80K. The purified helium gas output from the secondary adsorber passes sequentially through the second heat exchanger and the first heat exchanger to complete the recovery of the cold energy of purified helium gas below 80K.

9. The crude helium purification method according to claim 7, characterized in that: The modified coconut shell activated carbon in S4 undergoes the following modification treatment: S41: Carbonize the coconut shell at 650~750℃ for 2~3 hours to remove volatile matter; S42: Activated with water vapor at 850~950℃ for 4~5 hours to form a rich microporous structure; S43: In neon gas, at 700℃ for 2 hours, surface oxygen-containing groups are removed and polarity is reduced to obtain modified coconut shell activated carbon; S44: Add boron and trivalent titanium ions and mix them in modified coconut shell activated carbon.

10. The method for purifying crude helium according to claim 7, characterized in that: It also includes periodic regeneration of the primary and secondary adsorbents. Since both the primary and secondary adsorbents employ a dual-tower system, the regeneration process includes: A1: When the adsorption saturation rate of the primary or secondary adsorbent in one of the adsorption pathways exceeds 80%, the current adsorption pathway is closed, and another adsorption pathway is started at the same time to carry out adsorption continuously. A2. Hot nitrogen gas at 50~100℃ is introduced into the heat exchange layer of the regenerated primary adsorber, and high-purity helium gas at 20℃~30℃ is introduced into the heat exchange layer of the secondary adsorber to raise the temperature of the space where the primary adsorbent is located to above 220K and the temperature of the space where the secondary adsorbent is located to above 100K. A3: For the regeneration of the primary adsorbent, when the temperature of the space containing the primary adsorbent reaches above 220K and the pressure is less than 25kPa.G, turn on the vacuum pump to evacuate the space and allow the hydrogen, argon, and nitrogen adsorbed on the primary adsorbent to desorb. For the regeneration of the secondary adsorbent, when the temperature of the space containing the secondary adsorbent reaches 100K and the pressure is less than 25kPa.G, turn on the vacuum pump to evacuate the space and allow the neon in the secondary adsorbent to desorb. A4: Continuously depressurize the adsorber. When the adsorber pressure reaches 200 Pa, one regeneration and desorption cycle is complete. Begin injecting high-purity helium at room temperature into the inner layer of the adsorber until atmospheric pressure is reached. Then, restart the vacuum pump. After three vacuum cycles, hydrogen, argon, and nitrogen in the primary adsorbent are completely desorbed; neon in the secondary adsorbent is completely desorbed. A5: High-purity helium is introduced into the raw material layer of the regenerated primary or secondary adsorber. The internal temperature of the primary or secondary adsorber is cooled by heat exchange, and helium is replenished in real time to keep the pressure of the raw material layer of the primary or secondary adsorber at normal pressure. The primary or secondary adsorbent re-enters the state of maximum adsorption capacity, ready for use in the next switching of the process.

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