A helium purification method capable of preventing catalyst poisoning

Abstract

The application discloses a helium purification method capable of preventing catalyst poisoning, and comprises the following steps: cooling raw material gas until the impurity gas with liquefaction temperature equal to or higher than nitrogen is liquefied, and obtaining intermediate product gas containing neon, hydrogen and helium through gas-liquid separation; and low-temperature adsorption of neon in the intermediate product gas to obtain mixed gas, wherein the impurity gas contains nitrogen; and hydrogen in the mixed gas is removed by using a catalyst to obtain helium product, wherein at least one first type of gas capable of poisoning the catalyst exists in the impurity gas. The application can eliminate the risk of explosion, does not need external gas, simplifies the process and improves safety. Temperature optimization of the catalytic reaction can improve the hydrogen removal rate and the catalyst life, and the extraction of high-purity hydrogen and neon as byproducts can increase resource utilization, and break the limitation of traditional processes.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of gas separation, and in particular to a helium purification method capable of preventing catalyst poisoning. BACKGROUND

[0002] Traditional helium purification methods often face the problem of catalyst poisoning, because impurities such as the first type of gas in the raw gas cannot be completely removed, and the residual impurities in the mixed gas cause the catalyst to be deactivated. At the same time, the catalytic dehydrogenation process is inefficient, and the accumulation of impurities causes frequent catalyst replacement, increasing the cost. The high concentration of hydrogen in the raw gas also poses an explosion risk, and external inert gas is usually added for dilution, which complicates the process and is not safe. Energy consumption is also a bottleneck, and the cold energy is not effectively recovered, resulting in high energy consumption during system operation. These problems are due to the fact that traditional processes rely on a single separation technology, which cannot simultaneously process impurities and energy recovery, limiting the efficiency and reliability of helium purification. Based on this background, the present application aims to overcome the problems of catalyst poisoning and safety bottlenecks. SUMMARY

[0003] The present application proposes a helium purification method capable of preventing catalyst poisoning, comprising:

[0004] S1, cooling the raw gas until the liquefaction temperature of the impurities in the raw gas is equal to or higher than that of nitrogen, and obtaining an intermediate product gas containing neon, hydrogen and helium by gas-liquid separation, and adsorbing the neon in the intermediate product gas at low temperature to obtain a mixed gas, wherein the impurities contain nitrogen;

[0005] S2, removing hydrogen from the mixed gas using a catalyst to obtain a helium product, wherein at least one first type of gas in the impurities can poison the catalyst.

[0006] Further, S2 further comprises: desorption treatment of the catalyst to obtain high-purity hydrogen.

[0007] Further, the minimum temperature for liquefying the impurities in S1 is higher than the minimum temperature for low-temperature adsorption of neon in S1, so that the trace amount of impurities remaining in the intermediate product gas is liquefied.

[0008] Further, the low-temperature adsorption of neon in the intermediate product gas to obtain the mixed gas further comprises: desorption to extract neon.

[0009] Further, the desorption to extract high-purity neon further comprises: warming and gasifying the liquid nitrogen and the liquid impurities and then removing them.

[0010] Further, the mixed gas can be used for precooling the raw gas before separating and removing a plurality of intermediate gases.

[0011] Further, before the mixed gas is pre-cooled, the method further comprises: mixing part of the helium product into the raw gas to reduce the proportion of hydrogen in the raw gas to a preset safe range.

[0012] Further, when the hydrogen in the mixed gas is removed by using a catalyst to obtain the helium product, the temperature is controlled to be between 5℃ and 15℃; when the raw gas is cooled until the nitrogen and the impurities in the raw gas are liquefied, the temperature is controlled to be below 77K; and when the neon in the intermediate product gas is removed by low-temperature adsorption to obtain the mixed gas, the temperature is controlled to be between 77K and 30K.

[0013] The present application can completely remove the first type of gas and other impurities through multi-stage low-temperature separation, can completely prevent catalyst poisoning, and can ensure continuous and efficient operation of the catalytic dehydrogenation. The cold energy recovery of the mixed gas can be used for pre-cooling of the raw gas, which can greatly reduce the energy consumption of the system. The helium product can be used to dilute the hydrogen concentration in the raw gas, which can eliminate the explosion risk and simplify the process to improve safety. The temperature optimization of the catalytic reaction can improve the hydrogen removal rate and the service life of the catalyst. The extraction of the high-purity hydrogen and neon byproducts can increase the resource utilization rate. These effects are coupled with the synchronous design of adsorption and liquefaction, which breaks the limitations of traditional processes. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 A flowchart of a helium purification method for preventing catalyst poisoning is provided for the present application;

[0015] Figure 2 A partial flowchart of a helium purification method for preventing catalyst poisoning is provided for the present application. DETAILED DESCRIPTION

[0016] REFERENCE Figure 1 and Figure 2 The present application provides a helium purification method for preventing catalyst poisoning, which comprises:

[0017] S1, cooling the raw gas until the nitrogen and the impurities in the raw gas are liquefied, and obtaining an intermediate product gas containing neon, hydrogen and helium by gas-liquid separation, wherein the impurities contain nitrogen.

[0018] S1, specifically comprises:

[0019] S11, cooling the raw gas until the nitrogen and the impurities in the raw gas are liquefied, and obtaining an intermediate product gas containing neon, hydrogen and helium, wherein the temperature is controlled to be below 77K during the process.

[0020] 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.

[0021] S13. The liquid impurities are heated and vaporized, then removed. Specifically, this process is completed in an adsorption tower.

[0022] S14. Desorption and extraction of neon gas.

[0023] 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.

[0024] 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.

[0025] S2. Use a catalyst to remove hydrogen from the mixed gas to obtain helium product, specifically high-purity helium.

[0026] The impurity gas contains at least one type of first gas that can poison the catalyst.

[0027] Part of the helium product can be used to circulate into the raw gas to reduce the proportion of hydrogen in the raw gas to a preset safety range to prevent explosion.

[0028] When using a catalyst to remove hydrogen from the mixed gas to obtain a helium product, the temperature is controlled between 5°C and 15°C, preferably 10°C.

[0029] In the S2 step, the mixed gas obtained from S1, which contains hydrogen and helium and is the result of the previous separation, is directly introduced into the catalyst treatment unit. The catalyst plays a crucial role at this stage, removing the hydrogen component through a catalytic reaction. The operating temperature is strictly controlled within a specific range, which is optimized to match the optimal activity window of the catalyst, ensuring efficient and stable reaction. S2 significantly improves the hydrogen removal rate through precise temperature control, while maintaining the long-term performance of the catalyst, avoiding efficiency loss due to temperature fluctuations. In this process, the hydrogen in the mixed gas is selectively converted or adsorbed, generating a high-purity helium product. It is worth noting that since S1 has completely removed impurities such as the first type of gas, the catalyst is completely free from poisoning, breaking the dilemma of frequent catalyst replacement due to residual impurities in traditional processes, achieving continuous and reliable operation. Part of the obtained helium product is directly output as an end resource, and the other part is recycled back to the raw gas system. The recycling mechanism aims to dilute the hydrogen concentration in the raw gas to below the safety threshold, thereby eliminating potential explosion hazards. S2 enhances the safety of the overall process through helium recycling, without the need for additional inert gas, saving costs and simplifying the process. The recycled helium then participates in the pre-cooling stage of the raw gas, cooperating with the mixed gas cooling recovery in S1 to form an energy closed loop. Finally, the remaining helium product is used for subsequent applications or storage.

[0030] Throughout the S2 process, the helium after catalyst dehydrogenation immediately serves the recycling link, and the recycling effect is fed back to the raw material pretreatment, ensuring system self-consistency and efficiency. S2 solves the long-standing problems of catalyst failure and safety hazards in the field through the coupling of temperature optimization and impurity prevention.

[0031] S3, desorption treatment of the catalyst to obtain high-purity hydrogen.

[0032] S3 releases the adsorbed hydrogen component by heating the catalyst to perform desorption operation, forming 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 the first type of gas, the catalyst maintains high efficiency and activity, and S3 can significantly improve hydrogen recovery efficiency and reduce energy consumption through the impurity prevention mechanism.

[0033] The above merely describes preferred embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art can make equivalent replacements or changes within the technical scope disclosed by the present application and according to the technical solutions and inventive concept of the present application, which should be covered within the protection scope of the present application.

Claims

1. A method of purifying helium gas which is capable of preventing catalyst poisoning, characterized by, The method comprises: S1, cooling the raw gas until the liquefaction temperature of the impurity gas in the raw gas is equal to or higher than that of nitrogen, and the intermediate product gas containing neon, hydrogen and helium is obtained by gas-liquid separation, and the neon in the intermediate product gas is adsorbed at low temperature to obtain a mixed gas, wherein the impurity gas contains nitrogen; S2, removing hydrogen in the mixed gas by using a catalyst to obtain a helium product, wherein at least one first type of gas in the impurity gas can poison the catalyst; Wherein, the lowest temperature of liquefying the impurity gas in S1 is higher than the lowest temperature of adsorbing neon at low temperature in S1, so that the trace amount of impurity gas remaining in the intermediate product gas is liquefied.

2. The helium purification method for preventing catalyst poisoning as described in claim 1, characterized in that, S2 further comprises: 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 low-temperature adsorption of neon in the intermediate product gas to obtain the mixed gas further comprises: desorption to extract neon.

4. The method of claim 3, wherein the catalyst is poisoned by water vapor. The desorption to extract high-purity neon further comprises: warming and gasifying liquid nitrogen and liquid impurity gas and then removing.

5. The method of claim 1, wherein the catalyst is poisoned by water vapor. The mixed gas can be used for precooling the raw gas before removing a plurality of intermediate gases.

6. The method of claim 5, wherein the catalyst is poisoned by water vapor. Before the mixed gas is used for precooling the raw gas, it further comprises: mixing part of the helium product into the raw gas to reduce the proportion of hydrogen in the raw gas to a preset safety range.

7. The method of claim 1, wherein the catalyst is poisoned by water vapor. When the catalyst is used to remove hydrogen in the mixed gas to obtain a helium product, the temperature is controlled between 5°C and 15°C; when the raw gas is cooled until the nitrogen and impurity gas in the raw gas are liquefied, the temperature is controlled below 77K; when the neon in the intermediate product gas is adsorbed at low temperature to obtain a mixed gas, the temperature is controlled between 77K and 30K.

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