Helium purification method capable of preventing catalyst poisoning

Abstract

The invention discloses a helium purification method capable of preventing catalyst poisoning, which comprises the following steps: cooling raw material gas until miscellaneous gas with liquefaction temperature equal to or higher than that of nitrogen in the raw material gas is liquefied, carrying out gas-liquid separation to obtain intermediate product gas containing neon gas, hydrogen gas and helium gas, and adsorbing the neon gas in the intermediate product gas at low temperature to obtain mixed gas, the miscellaneous gas contains nitrogen; hydrogen in the mixed gas is removed through a catalyst, so that a helium product is obtained, and at least one first type of gas capable of poisoning the catalyst exists in the offensive gas. The explosion risk can be eliminated, external gas is not needed, the process is simplified, and safety is improved. The temperature optimization catalytic reaction can improve the hydrogen removal rate and prolong the service life of the catalyst, the extraction of byproducts of high-purity hydrogen and neon can increase the resource utilization rate, and the limitation of the traditional process is broken through.

Description

Technical Field

[0001] This invention relates to the field of gas separation technology, and in particular to a helium purification method that can prevent catalyst poisoning. Background Technology

[0002] Traditional helium purification methods often face catalyst poisoning problems because impurities in the feed gas, such as type I gases, are not completely removed and remain in the mixture, leading to catalyst deactivation. Simultaneously, the catalytic dehydrogenation process is inefficient, and impurity accumulation necessitates frequent catalyst replacements, increasing costs. Excessive hydrogen concentration in the feed gas also poses an explosion risk, typically requiring dilution with external inert gases, making the process complex and unsafe. Energy consumption is also a bottleneck, as cold energy is not effectively recovered, resulting in high system energy consumption. These problems stem from the reliance on single separation technologies in traditional processes, which cannot simultaneously handle impurities and recover energy, limiting the efficiency and reliability of helium purification. This invention aims to overcome the catalyst poisoning and safety bottlenecks. Summary of the Invention

[0003] This invention proposes a helium purification method that can prevent catalyst poisoning, comprising: S1. Cool the raw gas until the impurities in the raw gas with a liquefaction temperature equal to or higher than that of nitrogen are liquefied. Obtain an intermediate product gas containing neon, hydrogen and helium through gas-liquid separation. Adsorb neon in the intermediate product gas at low temperature to obtain a mixed gas, wherein the impurities contain nitrogen. S2. Using a catalyst to remove hydrogen from the mixed gas to obtain a helium product, wherein at least one type of first gas that can poison the catalyst is present in the impurity gas.

[0004] Furthermore, after S2, the process also includes: desorption treatment of the catalyst to obtain high-purity hydrogen.

[0005] Furthermore, the lowest temperature at which impurities are liquefied in S1 is higher than the lowest temperature at which neon is adsorbed at low temperature in S1, so that trace amounts of impurities remaining in the intermediate product gas are liquefied.

[0006] Furthermore, the neon gas in the intermediate product gas is adsorbed at low temperature to obtain a mixed gas, which is then followed by desorption to extract the neon gas.

[0007] Furthermore, the desorption and extraction of high-purity neon gas also includes: heating and vaporizing liquid nitrogen and liquid impurities, and then removing them.

[0008] Furthermore, the mixed gas can be used to precool the feed gas before separating and removing various intermediate gases.

[0009] Furthermore, before precooling the feed gas with the mixed gas, the process also includes mixing a portion of helium product into the feed gas to reduce the hydrogen content in the feed gas to a preset safe range.

[0010] Furthermore, when using a catalyst to remove hydrogen from the mixed gas to obtain helium product, the temperature is controlled between 5°C and 15°C; when cooling the raw gas until the nitrogen and impurities in the raw gas are liquefied, the temperature is controlled below 77K; when using low-temperature adsorption of neon from the intermediate product gas to obtain a mixed gas, the temperature is controlled between 77K and 30K.

[0011] This invention thoroughly removes impurities such as type I gases through multi-stage low-temperature separation, completely preventing catalyst poisoning and ensuring continuous and efficient operation of catalytic dehydrogenation. The recovered cooling capacity of the mixed gas is used for pre-cooling of the feed gas, significantly reducing system energy consumption. The circulating helium product dilutes the hydrogen concentration in the feed gas, eliminating the risk of explosion, eliminating the need for external gases, simplifying the process, and improving safety. Temperature-optimized catalytic reactions improve the hydrogen removal rate and catalyst lifespan. The extraction of high-purity hydrogen and neon byproducts increases resource utilization. These effects, coupled with the simultaneous design of adsorption and liquefaction, break through the limitations of traditional processes. Attached Figure Description

[0012] Figure 1 This is a flowchart of a helium purification method that can prevent catalyst poisoning, as proposed in this invention. Figure 2 This is a partial flowchart of a helium purification method proposed in this invention to prevent catalyst poisoning. Detailed Implementation

[0013] refer to Figure 1 and Figure 2 This invention proposes a helium purification method that can prevent catalyst poisoning, comprising: S1. The feed gas is cooled until any impurities in the feed gas with a liquefaction temperature equal to or higher than that of nitrogen are liquefied. An intermediate product gas containing neon, hydrogen, and helium is obtained through gas-liquid separation. Neon in the intermediate product gas is then adsorbed at low temperature to obtain a mixed gas, in which the impurities include nitrogen. The lowest temperature at which the impurities are liquefied in S1 is higher than the lowest temperature at which neon is adsorbed at low temperature in S1, ensuring that trace amounts of residual impurities in the intermediate product gas are liquefied.

[0014] S1, specifically includes: S11. Cool the raw gas until the nitrogen and impurities in the raw gas are liquefied, and obtain intermediate product gas containing neon, hydrogen and helium through gas-liquid separation. During this process, the temperature is controlled below 77K.

[0015] S12. Low-temperature adsorption of neon gas from the intermediate product gas yields a mixed gas containing hydrogen and helium. During this process, the temperature is controlled between 77K and 30K, and trace amounts of impurities remaining in the intermediate product gas, including type I gases, are liquefied. This mixed gas can be used to pre-cool the feed gas before separating and removing various intermediate gases.

[0016] S13. The liquid impurities are heated and vaporized, then removed. Specifically, this process is completed in an adsorption tower.

[0017] S14. Desorption and extraction of neon gas.

[0018] In S1, the feed gas is first cooled to a temperature below the liquefaction point of nitrogen, causing impurities to liquefy. Then, through gas-liquid separation, these liquefied components are removed, leaving gaseous neon, hydrogen, and helium as intermediate products. This process utilizes the significant difference in liquefaction temperatures between the gases to ensure that hydrogen and helium are retained intact without condensation. Next, this intermediate product gas enters a low-temperature adsorption stage, where the temperature is set within a specific low-temperature range. The adsorbent material efficiently captures neon components while simultaneously causing trace amounts of residual impurities to further liquefy and precipitate. These impurities include Type I gases that can poison subsequent catalysts. Liquid impurities adhere to the adsorption tower, while unadsorbed or unliquefied hydrogen and helium coalesce into a mixture. This mixture is then recycled to cool the original feed gas, lowering its temperature before entering S1 processing, thereby reducing system energy consumption. Afterward, the adsorption tower is heated to re-vaporize and remove the previously liquefied impurities, preventing impurity accumulation and equipment blockage. Finally, the adsorbent is desorbed to release high-purity neon gas as a valuable byproduct.

[0019] Throughout the process, the intermediate product gas from S11 is directly supplied to S12 for adsorption. The mixed gas output from S12 is not only used in the subsequent hydrogen removal stage but is also recycled to the feed gas precooling stage. The gasification removal in S13 ensures the cleanliness of the adsorption tower before it is used for desorption in S14. The neon gas extracted in S14 is one of the end products. S12, through simultaneous low-temperature adsorption and liquefaction, can completely eliminate the residue of the first type of gas, preventing it from causing catalyst poisoning during the hydrogen removal stage. At the same time, the cold energy recovery mechanism of the mixed gas breaks through the limitation of high energy consumption in traditional processes, achieving efficient resource reuse.

[0020] S2. Use a catalyst to remove hydrogen from the mixed gas to obtain helium product, specifically high-purity helium.

[0021] The impurity gas contains at least one type of first gas that can poison the catalyst.

[0022] Some helium products can be recycled into the feed gas to reduce the proportion of hydrogen in the feed gas to a preset safe range to prevent explosion.

[0023] When using a catalyst to remove hydrogen from a gas mixture to obtain helium, the temperature is controlled between 5°C and 15°C, preferably 10°C.

[0024] In step S2, the mixed gas obtained from S1, containing hydrogen and helium, directly enters the catalyst processing unit. This mixture is the result of the preceding separation. The catalyst plays a crucial role in this stage, removing hydrogen through a catalytic reaction. The operating temperature is strictly controlled within a specific range, optimized to match the catalyst's optimal activity window, ensuring efficient and stable reaction. S2's precise temperature control significantly improves the hydrogen removal rate while maintaining long-term catalyst performance, avoiding efficiency loss due to temperature fluctuations. During this process, hydrogen in the mixed gas is selectively converted or adsorbed, generating high-purity helium. Notably, because S1 thoroughly removes impurities such as type I gases, the catalyst is completely free from poisoning. This design overcomes the traditional process's reliance on frequent catalyst replacements due to impurity residues, enabling continuous and reliable operation. Part of the resulting helium product is directly output as a terminal resource, while the other part is recycled back to the feed gas system. This recycling mechanism aims to dilute the hydrogen concentration in the feed gas, reducing it below a safe threshold to eliminate potential explosion hazards. S2 significantly enhances the overall process safety through helium recycling, eliminating the need for additional inert gas, thus saving costs and simplifying the process. This recycled helium then participates in the pre-cooling stage of the feed gas, synergizing with the heat recovery from the mixed gas in S1 to form an energy closed loop. Finally, the remaining helium product is used for subsequent applications or storage.

[0025] Throughout the S2 process, the helium gas produced after catalyst dehydrogenation is immediately used in the recycling process, and the recycling effect is fed back to the feedstock pretreatment, ensuring the system's self-consistency and high efficiency. S2 addresses long-standing issues of catalyst failure and safety hazards in the field by coupling temperature optimization with impurity prevention.

[0026] S3. Desorb the catalyst to obtain high-purity hydrogen.

[0027] S3 performs desorption by heating the catalyst, releasing the adsorbed hydrogen components to form a high-purity hydrogen product. This product directly serves downstream applications or storage processes. Since S1 and S2 have completely eliminated toxic impurities such as type I gases, the catalyst maintains high efficiency. S3, through its impurity prevention mechanism, can significantly improve hydrogen recovery efficiency and reduce energy consumption.

[0028] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A helium purification method that can prevent catalyst poisoning, characterized in that, include: S1. Cool the raw material gas until the impurities in the raw material gas with a liquefaction temperature equal to or higher than that of nitrogen are liquefied. Obtain an intermediate product gas containing neon, hydrogen and helium through gas-liquid separation. Adsorb neon in the intermediate product gas at low temperature to obtain a mixed gas, wherein the impurities contain nitrogen. S2. Using a catalyst to remove hydrogen from the mixed gas to obtain a helium product, wherein at least one type of first gas that can poison the catalyst is present in the impurity gas.

2. The helium purification method for preventing catalyst poisoning as described in claim 1, characterized in that, S2 is followed by: desorption treatment of the catalyst to obtain high-purity hydrogen.

3. The helium purification method for preventing catalyst poisoning as described in claim 1, characterized in that, The lowest temperature at which impurities are liquefied in S1 is higher than the lowest temperature at which neon is adsorbed at low temperature in S1, so that trace amounts of impurities remaining in the intermediate product gas can be liquefied.

4. The helium purification method for preventing catalyst poisoning as described in claim 3, characterized in that, The process involves low-temperature adsorption of neon gas from intermediate products to obtain a mixed gas, followed by desorption to extract the neon gas.

5. The helium purification method for preventing catalyst poisoning as described in claim 4, characterized in that, The process of desorption to extract high-purity neon gas also includes heating and vaporizing liquid nitrogen and other liquid impurities, followed by their removal.

6. The helium purification method for preventing catalyst poisoning as described in claim 3, characterized in that, The mixed gas can be used to precool the feed gas before separating and removing various intermediate gases.

7. The helium purification method for preventing catalyst poisoning as described in claim 6, characterized in that, Before precooling the feed gas with the mixed gas, the process also includes mixing some helium products into the feed gas to reduce the hydrogen content in the feed gas to a preset safe range.

8. The helium purification method for preventing catalyst poisoning as described in claim 3, characterized in that, When using a catalyst to remove hydrogen from a mixed gas to obtain helium, the temperature is controlled between 5°C and 15°C; when cooling the raw gas until the nitrogen and impurities in the raw gas are liquefied, the temperature is controlled below 77K; when using low-temperature adsorption of neon from the intermediate product gas to obtain a mixed gas, the temperature is controlled between 77K and 30K.

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