System for extracting helium

Abstract

The embodiment of the invention discloses a system for extracting helium, which comprises a pretreatment module for receiving external mixed gas to be treated and pretreating the mixed gas to be treated; the membrane separation module is used for receiving the mixed gas pretreated by the pretreatment module and removing part of gas impurities in the mixed gas; at least one group of adsorption modules; the adsorption module comprises a first adsorption column and a second adsorption column which are arranged in parallel; the first adsorption column and the second adsorption column are configured to alternately receive the mixed gas output by the previous processing module and adsorb residual gas impurities in the received mixed gas. According to the system, the pretreatment module, the membrane separation module and the adsorption module are used for separating and adsorbing the to-be-treated mixed gas received from the outside, high-purity helium is finally generated, no phase change exists in the whole process, energy consumption is low, efficiency is high, other gas impurities cannot be introduced, the purity of the generated helium can reach 5N or above, and safety and reliability are achieved.

Description

Technical Field

[0001] The present application relates to the technical field of gas purification, and more specifically, to a system for extracting helium. Background Art

[0002] Helium is a rare gas that is colorless and odorless at room temperature. It has stable chemical properties, extremely low boiling point, extremely small molecular size, extremely low solubility in water, extremely high ionization energy, high specific heat, and high thermal conductivity. It is widely used in high-tech product manufacturing, aerospace, national defense, military industry, and medical fields. However, helium is very scarce on the earth and is widely distributed but extremely uneven. my country is a country with very poor helium resources. Helium resources are scattered and of low grade. The helium content in natural gas is low. More than 95% of helium needs to be imported, and the external dependence is extremely high. It is crucial to explore low-cost helium extraction technology for low concentrations.

[0003] Existing helium extraction technologies mainly include cryogenics, adsorption separation, membrane separation and integrated helium extraction. Cryogenics is the most mainstream method, but it has the problems of high energy consumption and poor economy when the helium content is low. In addition, since the size of hydrogen molecules is similar to that of helium, membrane separation and physical adsorption methods are often difficult to remove the impurity. The most commonly used method is the use of catalytic dehydrogenation equipment, but it will introduce oxygen impurities. The presence of oxygen may also cause explosion safety issues in subsequent processing. Summary of the invention

[0004] The object of the present invention is to provide a system for extracting helium to solve at least one of the above technical problems.

[0005] In order to achieve at least one of the above purposes, the present application adopts the following technical solutions:

[0006] The present application provides a system for extracting helium, comprising a plurality of processing modules;

[0007] Multiple processing modules include

[0008] A pre-processing module is used to receive the mixed gas to be processed from the outside and pre-process the mixed gas to be processed;

[0009] The membrane separation module is used to receive the mixed gas pretreated by the pretreatment module and remove some gas impurities in the mixed gas;

[0010] at least one set of adsorption modules;

[0011] The adsorption module comprises

[0012] A first adsorption column and a second adsorption column arranged in parallel;

[0013] The first adsorption column and the second adsorption column are configured to alternately receive the mixed gas output by the previous processing module and adsorb the remaining gas impurities in the received mixed gas.

[0014] Optionally, the adsorption module has two groups arranged in series, namely a first adsorption module and a second adsorption module;

[0015] The first adsorption column and the second adsorption column in the first adsorption module are respectively connected to the membrane separation module to alternately receive the mixed gas output by the membrane separation module to generate a hydrogen-helium mixed gas;

[0016] The first adsorption column and the second adsorption column in the second adsorption module are respectively connected to the first adsorption module to alternately receive the hydrogen-helium mixed gas and adsorb hydrogen in the hydrogen-helium mixed gas to generate high-purity helium.

[0017] Optionally, the first adsorption column and the second adsorption column in the first adsorption module are both MOFs adsorption columns;

[0018] The first adsorption column and the second adsorption column in the second adsorption module are both hydrogen storage alloy adsorption columns.

[0019] Optionally, the adsorption module further comprises: a first gas filling pipeline and a second gas filling pipeline respectively connected to one end of the first adsorption column and one end of the second adsorption column, the first gas filling pipeline being used to deliver high-purity helium to the first adsorption column, and the second gas filling pipeline being used to deliver high-purity helium to the second adsorption column;

[0020] A first gas outlet pipeline and a second gas outlet pipeline respectively connected to the other end of the first adsorption column and the other end of the second adsorption column;

[0021] When the first gas filling pipeline delivers high-purity helium to the first adsorption column, gas impurities absorbed in the first adsorption column are output to the outside through the first gas outlet pipeline;

[0022] When the second gas filling pipeline delivers high-purity helium to the second adsorption column, gas impurities absorbed in the second adsorption column are output to the outside through the second gas outlet pipeline.

[0023] Optionally, a first switch is disposed at both ends of the first adsorption column, and a second switch is disposed at both ends of the second adsorption column;

[0024] The first inflation pipeline comprises a first outlet, the first outlet is located between one of the first switches and the first adsorption column and is in communication with the first adsorption column;

[0025] The second inflation pipeline includes a second outlet, the second outlet is located between one of the second switches and the second adsorption column and is in communication with the second adsorption column;

[0026] The first gas outlet pipeline comprises a first inlet, the first inlet is located between the other first switch of the two and the first adsorption column and is in communication with the first adsorption column;

[0027] The second air outlet pipeline comprises a second inlet, which is located between the other second switch and the second adsorption column and is communicated with the second adsorption column.

[0028] Optionally, the first inflation pipeline and the first air outlet pipeline are respectively provided with a third switch, and the second inflation pipeline and the second air outlet pipeline are respectively provided with a fourth switch;

[0029] When the first adsorption column is in an adsorption state, the first switch and the fourth switch are in an open state, and the second switch and the third switch are in a closed state;

[0030] When the second adsorption column is in an adsorption state, the first switch and the fourth switch are in a closed state, and the second switch and the third switch are in an open state.

[0031] Optionally, the membrane separation module comprises

[0032] At least one primary membrane separator communicated with the pretreatment module and used to receive the mixed gas pretreated by the pretreatment module;

[0033] a secondary membrane separator connected to the primary membrane separator via a compressor and used to receive the mixed gas outputted from the primary membrane separator;

[0034] The adsorption module is communicated with the secondary membrane separator and receives the mixed gas output by the secondary membrane separator.

[0035] Optionally, the tail gas output from the secondary membrane separator is input into the primary membrane separator again through a circulation pipeline.

[0036] Optionally, a preheater is provided between the pretreatment module and the membrane separation module.

[0037] Optionally, heating belts are respectively provided on the side walls of the first adsorption column and the second adsorption column.

[0038] The beneficial effects of this application are as follows:

[0039] In view of the problems existing in the current prior art, the present application provides a system for extracting helium. The setting of multiple processing modules can sequentially purify the mixed gas to be processed received by the system from the outside, and finally generate high-purity helium. Specifically, the mixed gas to be processed received from the outside can be deacidified, desulfurized, demercured, demisted and dried by the pretreatment module, and the generated mixed gas is transmitted to the membrane separation module. The membrane separation module can remove most of the gas impurities in the mixed gas output from the pretreatment module, such as CO2, CH4 and N2. After the membrane separation module removes most of the gas impurities, the volume fraction of helium in the mixed gas output by the membrane separation module can reach 85% to 90%, and then the first adsorption column and the second adsorption column in the adsorption module adsorb other gas impurities in the mixed gas, and finally form high-purity helium. The alternating use of the first adsorption column and the second adsorption column can keep the adsorption module in a working state at all times, with high working efficiency, and there will be no situation where there is only one adsorption column, and when the gas impurities adsorbed by the adsorption column reach a saturated state, the adsorption module needs to stop working and clean it. During the use of the adsorption module, when the gas impurities adsorbed by the first adsorption column reach a saturated state, the adsorption is switched to the second adsorption column, and the first adsorption column can be cleaned at this time. When the gas impurities adsorbed by the second adsorption column reach a saturated state, the adsorption is switched to the first adsorption column, and the second adsorption column can be cleaned at this time. The system provided in the present application separates and adsorbs the mixed gas to be treated received from the outside by using a pretreatment module, a membrane separation module and an adsorption module, and finally generates high-purity helium. There is no phase change throughout the process, low energy consumption, high efficiency, and no other gas impurities will be introduced. The purity of the generated helium can reach more than 5N, which is safe and reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings.

[0041] Figure 1 A schematic diagram showing the overall structure of a system for extracting helium in one embodiment of the present application is shown. DETAILED DESCRIPTION

[0042] In the following description, for the purpose of explanation, in order to provide a thorough understanding of one or more embodiments, numerous specific details are set forth. However, it is apparent that these embodiments may also be implemented without these specific details.

[0043] In the description of the present application, it should be noted that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0044] It should also be noted that, in the description of the present application, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of further restrictions, the elements defined by the statement "comprise one..." do not exclude the presence of other identical elements in the process, method, article or equipment including the elements.

[0045] In order to solve the problems existing in the prior art, an embodiment of the present application provides a system for extracting helium, such as Figure 1As shown, it includes multiple processing modules; the multiple processing modules include a pretreatment module 1, which can be a filter for receiving the mixed gas to be processed from the outside and pretreatment the mixed gas to be processed; in the present application, the mixed gas to be processed is described by taking natural gas as an example; a membrane separation module for receiving the mixed gas pretreated by the pretreatment module 1 and removing some gas impurities in the mixed gas; it also includes at least one group of adsorption modules; the adsorption module includes a first adsorption column 51 and a second adsorption column 52 arranged in parallel; the first adsorption column 51 and the second adsorption column 52 are configured to alternately receive the mixed gas output by the previous processing module, and adsorb the remaining gas impurities in the received mixed gas. The previous processing module here refers to a processing module adjacent to the adsorption module having the first adsorption column 51 and the second adsorption column 52, and the processing module can transmit the output mixed gas to the adsorption module adjacent to it; for example, if there are two adsorption modules, namely the first adsorption module and the second adsorption module, the mixed gas output by the membrane separation module is transmitted to the first adsorption module, and the membrane separation module here is equivalent to the previous processing module of the first adsorption module; the mixed gas output by the first adsorption module is transmitted to the second adsorption module, and the first adsorption module here is equivalent to the previous processing module of the second adsorption module.

[0046] In the above-mentioned embodiment of the present application, the setting of multiple processing modules can sequentially purify the mixed gas to be processed received by the system from the outside, and finally generate high-purity helium. Specifically, the mixed gas to be processed received from the outside can be deacidified, desulfurized, demercured, demisted and dried by the pretreatment module 1, and the generated mixed gas is transmitted to the membrane separation module, which can remove most of the gas impurities in the mixed gas output from the pretreatment module 1, such as CO2, CH4 and N2. After the membrane separation module removes most of the gas impurities, the volume fraction of helium in the mixed gas output by the membrane separation module can reach 85% to 90%, and then the first adsorption column 51 and the second adsorption column 52 in the adsorption module adsorb other gas impurities in the mixed gas, and finally form high-purity helium. The alternating use of the first adsorption column 51 and the second adsorption column 52 can keep the adsorption module in a working state at all times, with high working efficiency, and there will be no situation where there is only one adsorption column and the adsorption module needs to stop working and clean up the gas impurities adsorbed by the adsorption column when the gas impurities reach a saturated state. During the use of the adsorption module, when the gas impurities adsorbed by the first adsorption column 51 reach a saturated state, it is switched to the second adsorption column 52 for adsorption, and the first adsorption column 51 can be cleaned at this time. When the gas impurities adsorbed by the second adsorption column 52 reach a saturated state, it is switched to the first adsorption column 51 for adsorption, and the second adsorption column 52 can be cleaned at this time. The system provided in the present application uses a pretreatment module 1, a membrane separation module and an adsorption module to separate and adsorb the mixed gas to be treated received from the outside, and finally generates high-purity helium. There is no phase change throughout the process, low energy consumption, high efficiency, and no other gas impurities will be introduced. The purity of the generated helium can reach more than 5N, which is safe and reliable.

[0047] In a specific embodiment, the membrane separation module includes at least one primary membrane separator 21 connected to the pretreatment module 1 and used to receive the mixed gas pretreated by the pretreatment module 1; a secondary membrane separator 22 connected to the primary membrane separator 21 through a compressor 7 and used to receive the mixed gas output by the primary membrane separator 21; the adsorption module is connected to the secondary membrane separator 22 and receives the mixed gas output by the secondary membrane separator 22. Polyimide (PI), polybenzimidazole (PBI), self-microporous polymer (PIMs) and carbon molecular sieve membrane (CMS) can be added to the primary membrane separator 21 and the secondary membrane separator 22, and a variety of materials can be combined.

[0048] The pretreatment module 1 removes acidity, desulfurization, demercuration, demisting and dries the mixed gas to be treated received from the outside, and then transmits the generated mixed gas to the primary membrane separator 21 of the membrane separation module. Here, when there are multiple primary membrane separators 21, the multiple primary membrane separators 21 are arranged in series in sequence. The number of primary membrane separators 21 is preferably three, which is set according to actual conditions; the primary membrane separator 21 separates the mixed gas received from the pretreatment module 1, mainly removing most of the gas impurities. The main components of the gas impurities are CH4, N2, O2 and various other hydrocarbon gases, etc. After removal, the pressure of the remaining mixed gas will be greatly reduced. In order to improve the separation effect, Before entering the secondary membrane separator 22, the mixed gas output from the primary membrane separator 21 needs to be compressed by the compressor 7 to a pressure close to that of the mixed gas received by the primary membrane separator 21, generally compressed to 1.8Mpa to 2.2Mpa. The compressed mixed gas then enters the secondary membrane separator 22. The secondary membrane separator 22 further separates the mixed gas and removes some gas impurities. The main components of the gas impurities are CO2, and also include CH4 and N2. At this time, the volume fraction of helium in the mixed gas output by the secondary membrane separator 22 can reach 85% to 90%. The secondary membrane separator 22 then transmits the output mixed gas to the adsorption module.

[0049] In practical applications, both the primary membrane separator 21 and the secondary membrane separator 22 will produce tail gas. Since the helium content in the tail gas produced by the primary membrane separator 21 is extremely low and can be ignored, it can be directly discharged to the collection device through the exhaust pipe 92. The tail gas output by the secondary membrane separator 22 is input to the inlet of the primary membrane separator 21 again through the circulation pipeline 91, and the tail gas is further separated, thereby improving the recovery rate of helium. It should be noted that if the tail gas pressure output by the secondary membrane separator 22 is similar to the pressure of the mixed gas received by the primary membrane separator 21, the compressor 7 does not need to be compressed. If the pressure is so small that it affects the separation efficiency of the primary membrane separator 21 after entering the primary membrane separator 21, it is necessary to use a compressor to compress it before entering the primary membrane separator 21.

[0050] In a specific embodiment, a preheater 8 is provided between the pretreatment module 1 and the membrane separation module, and specifically, a preheater 8 is provided between the pretreatment module 1 and the primary membrane separator 21. In order to improve the separation effect of the mixed gas entering the primary membrane separator 21, the mixed gas needs to reach a certain temperature, usually 30 to 40°C; therefore, when the external environment temperature is lower than 30°C, the preheater 8 is turned on, and the mixed gas output from the pretreatment module 1 is heated by the preheater 8 before entering the primary membrane separator 21.

[0051] In a specific embodiment, the adsorption module has two groups arranged in series, namely, a first adsorption module 3 and a second adsorption module 4; the first adsorption column 51 and the second adsorption column 52 in the first adsorption module 3 are respectively connected to the membrane separation module, so as to alternately receive the mixed gas output by the membrane separation module, that is, to alternately receive the mixed gas output by the secondary membrane separator 22, and absorb the remaining gas impurities in the mixed gas through the first adsorption module 3 to generate a hydrogen-helium mixed gas; the first adsorption column 51 and the second adsorption column 52 in the second adsorption module 4 are respectively connected to the first adsorption module 3, so as to alternately receive the hydrogen-helium mixed gas, and adsorb the hydrogen in the hydrogen-helium mixed gas to generate high-purity helium. In this embodiment, the first adsorption module 3 can absorb the remaining gas impurities in the mixed gas with a volume fraction of 85% to 90%, and generate a hydrogen-helium mixed gas, where the gas impurities are, for example, O2, CH4, CO, CO2, and N2; the second adsorption module 4 adsorbs the hydrogen in the hydrogen-helium mixed gas, and finally forms a high-purity helium.

[0052] In a specific embodiment, the adsorption module also includes: a first gas filling pipeline 53 and a second gas filling pipeline 54 respectively connected to one end of the first adsorption column 51 and one end of the second adsorption column 52, the first gas filling pipeline 53 is used to transport high-purity helium to the first adsorption column 51, and the second gas filling pipeline 54 is used to transport high-purity helium to the second adsorption column 52; a first gas outlet pipeline 55 and a second gas outlet pipeline 56 respectively connected to the other end of the first adsorption column 51 and the other end of the second adsorption column 52; when the first gas filling pipeline 53 transports high-purity helium to the first adsorption column 51, the gas impurities absorbed in the first adsorption column 51 are output to the outside through the first gas outlet pipeline 55; when the second gas filling pipeline 54 transports high-purity helium to the second adsorption column 52, the gas impurities absorbed in the second adsorption column 52 are output to the outside through the second gas outlet pipeline 56. The provision of the first charging pipeline 53, the second charging pipeline 54, the first gas outlet pipeline 55 and the second gas outlet pipeline 56 enables the first adsorption column 51 and the second adsorption column 52 to alternately receive the mixed gas output by the membrane separation module and adsorb gas impurities in the mixed gas.

[0053] When the gas impurities adsorbed by the first adsorption column 51 reach a saturated state, the second adsorption column 52 is switched to adsorption. At this time, high-purity helium is filled into the first adsorption column 51 through the first inflation pipeline 53 to blow the gas impurities adsorbed in the first adsorption column 51 to the first gas outlet pipeline 55, and the gas impurities are output to the outside through the first gas outlet pipeline 55, thereby completing the cleaning of the first adsorption column 51.

[0054] When the gas impurities adsorbed by the second adsorption column 52 reach a saturated state, the first adsorption column 51 is switched to be adsorbed. At this time, high-purity helium is filled into the second adsorption column 52 through the second gas filling pipeline 54. In this way, the gas impurities adsorbed in the second adsorption column 52 can be purged to the second gas outlet pipeline 56, and the gas impurities are output to the outside through the second gas outlet pipeline 56, thereby realizing the cleaning of the second adsorption column 52.

[0055] Specifically, one end of the first inflation pipeline 53 away from the first adsorption column 51 can be connected to one end of the second inflation pipeline 54 away from the second adsorption column 52, so that high-purity helium can be received through a receiving port; one end of the first gas outlet pipeline 55 away from the first adsorption column 51 can be connected to one end of the second gas outlet pipeline 56 away from the second adsorption column 52, so that the gas impurities absorbed in the first adsorption column 51 or the second adsorption column 52 can be discharged to the outside through one gas outlet.

[0056] Here, the time for delivering high-purity helium to the first adsorption column 51 or the second adsorption column 52 is less than the time for the first adsorption column 51 or the second adsorption column 52 to adsorb gas impurities, so as to ensure that when switching to the first adsorption column 51 or the second adsorption column 52, the first adsorption column 51 or the second adsorption column 52 is in a completely cleaned state; the time for the first adsorption column 51 to adsorb gas impurities and the time for purging with high-purity helium are set according to actual conditions.

[0057] In a specific embodiment, first switches 61 are respectively provided at both ends of the first adsorption column 51, and second switches 62 are respectively provided at both ends of the second adsorption column 52; the first inflation pipeline 53 includes a first outlet, which is located between one of the two first switches 61 and the first adsorption column 51 and is communicated with the first adsorption column 51; the second inflation pipeline 54 includes a second outlet, which is located between one of the two second switches 62 and the second adsorption column 52 and is communicated with the second adsorption column 52; the first air outlet pipeline 55 includes a first inlet, which is located between the other of the two first switches 61 and the first adsorption column 51 and is communicated with the first adsorption column 51; the second air outlet pipeline 56 includes a second inlet, which is located between the other of the two second switches 62 and the second adsorption column 52 and is communicated with the second adsorption column 52. When the first adsorption column 51 is in the adsorption state, the two first switches 61 are opened, the two second switches 62 are closed, the first inflation pipeline 53 is in the non-inflation state, the second inflation pipeline 54 is in the inflation state, the first outlet pipeline 55 is in the non-outlet state, and the second outlet pipeline 56 is in the outlet state; that is, the first adsorption column 51 receives the mixed gas from the previous module, and the second adsorption column 52 is in the cleaning state; when the second adsorption column 52 is in the adsorption state, the two second switches 62 are opened, the two first switches 61 are closed, the second inflation pipeline 54 is in the non-inflation state, the first inflation pipeline 53 is in the inflation state, the second outlet pipeline 56 is in the non-outlet state, and the first outlet pipeline 55 is in the outlet state; that is, the second adsorption column 52 receives the mixed gas from the previous module, and the first adsorption column 51 is in the cleaning state; the use of the two first switches 61 and the two second switches 62 can realize that the first adsorption column 51 and the second adsorption column 52 alternately receive the mixed gas from the previous module, thereby improving the separation efficiency of the mixed gas.

[0058] In a specific embodiment, the first inflation pipeline 53 and the first outlet pipeline 55 are respectively provided with a third switch 63, and the second inflation pipeline 54 and the second outlet pipeline 56 are respectively provided with a fourth switch 64; when the first adsorption column 51 is in the adsorption state, the first switch 61 and the fourth switch 64 are in the open state, and the second switch 62 and the third switch 63 are in the closed state; when the second adsorption column 52 is in the adsorption state, the first switch 61 and the fourth switch 64 are in the closed state, and the second switch 62 and the third switch 63 are in the open state. The use of the two third switches 63 can close or open the first outlet of the first inflation pipeline 53 and the first inlet of the first outlet pipeline 55, and the use of the two fourth switches 64 can close or open the second outlet of the second inflation pipeline 54 and the first inlet of the second outlet pipeline 56, thereby realizing the alternating cleaning of the first adsorption column 51 and the second adsorption column 52.

[0059] In a specific example, a heating belt 511 is provided on the side wall of the first adsorption column 51 and the second adsorption column 52, respectively. When high-purity helium is filled into the first adsorption column 51 or the second adsorption column 52, the first adsorption column 51 or the second adsorption column 52 is heated to 100° C. to 150° C. by the heating belt 511, so that the temperature of the high-purity helium entering the adsorption column can also reach 100° C. to 150° C., thereby improving the cleaning efficiency of the first adsorption column 51 or the second adsorption column 52. The temperature of the heating belt 511 can be controlled by a programmable temperature controller.

[0060] In actual application, the use process of the first adsorption module 3 is as follows: the first adsorption column 51 works first, and the second adsorption column 52 works later.The two first switches 61 are turned on, the two second switches 62, the two third switches 63 and the two fourth switches 64 are all turned off, the first adsorption column 51 in the first adsorption module 3 starts to receive the mixed gas output from the secondary membrane separator 22, and adsorbs the gas impurities in the mixed gas, and transports the generated hydrogen-helium mixture to the second adsorption module 4. The second adsorption column 52 is in a non-working state at this time, and the heating belts 511 wrapped on the side walls of the first adsorption column 51 and the second adsorption column 52 are not working. When the first adsorption column 51 is in a saturated state, the two first switches 61 and the two fourth switches 64 are all turned off, and the two second switches 62 and the two third switches 63 are all turned on, that is, the second adsorption column 52 starts to receive the mixed gas output from the secondary membrane separator 22. The mixed gas output by the separator 22 is absorbed and the gas impurities in the mixed gas are absorbed, and the generated hydrogen-helium mixture is transported to the second adsorption module 4. At this time, the heating belt 511 wrapped on the side wall of the second adsorption column 52 does not work, and the heating belt 511 wrapped on the side wall of the first adsorption column 51 is heated to 100-150° C. High-purity helium is transported to the first adsorption column 51 through the first inflation pipeline 53, so that the gas impurities absorbed in the first adsorption column 51 are output to the outside through the first gas outlet pipeline 55. When the second adsorption column 52 is in a saturated state, the two first switches 61 and the two fourth switches 64 are all turned on, and the two second switches 62 and the two third switches 63 are all turned off, that is, the first adsorption column 51 starts to receive the gas from the second adsorption column 52. The mixed gas output from the secondary membrane separator 22 is adsorbed, and the gas impurities in the mixed gas are adsorbed, and the generated hydrogen-helium mixture is transported to the second adsorption module 4. At this time, the heating belt 511 wrapped on the side wall of the first adsorption column 51 does not work, and the heating belt 511 wrapped on the side wall of the second adsorption column 52 is heated to 100-150° C., and high-purity helium is transported to the second adsorption column 52 through the second charging pipeline 54, so that the gas impurities absorbed in the second adsorption column 52 are output to the outside through the second gas outlet pipeline 56; when the first adsorption column 51 adsorbs impurities in the mixed gas output from the secondary membrane separator 22 and is in a saturated state, the two first switches 61 and the two fourth switches 64 are all closed, and the two second switches 62 and Both third switches 63 are turned on, that is, the second adsorption column 52 starts to receive the mixed gas output from the secondary membrane separator 22, and adsorbs gas impurities in the mixed gas, and transports the generated hydrogen-helium mixture to the second adsorption module 4. At this time, the heating belt 511 wrapped on the side wall of the second adsorption column 52 does not work, and the heating belt 511 wrapped on the side wall of the first adsorption column 51 is heated to 100-150°C, and high-purity helium is transported to the first adsorption column 51 through the first inflation pipeline 53, so that the gas impurities absorbed in the first adsorption column 51 are output to the outside through the first outlet pipeline 55; and so on, the first adsorption column 51 and the second adsorption column 52 alternately receive the mixed gas output from the secondary membrane separator 22.

[0061] The use process of the second adsorption module 4 is as follows: the first adsorption column 51 works first, and the second adsorption column 52 works later. The two first switches 61 are turned on, the two second switches 62, the two third switches 63 and the two fourth switches 64 are all turned off, the first adsorption column 51 in the second adsorption module 4 begins to receive the mixed gas output from the first adsorption module 3, and adsorbs the gas impurities in the mixed gas, and transports the generated high-purity helium to the collector. The second adsorption column 52 is in a non-working state at this time, and the heating belts 511 wrapped on the side walls of the first adsorption column 51 and the second adsorption column 52 are not working. When the first adsorption column 51 is in a saturated state, the two first switches 61 and the two fourth switches 64 are all turned off, and the two second switches 62 and the two third switches 63 are all turned on, that is, the second adsorption column 52 begins to receive the mixed gas from the first adsorption module 3. The module 3 outputs the hydrogen-helium mixed gas, and adsorbs the hydrogen in the hydrogen-helium mixed gas, and transports the generated high-purity helium to the collector. At this time, the heating belt 511 wrapped on the side wall of the second adsorption column 52 does not work, and the heating belt 511 wrapped on the side wall of the first adsorption column 51 is heated to 100-150°C, and high-purity helium is transported to the first adsorption column 51 through the first charging pipeline 53, so that the hydrogen absorbed in the first adsorption column 51 is output to the outside through the first gas outlet pipeline 55. When the second adsorption column 52 is in a saturated state, the two first switches 61 and the two fourth switches 64 are all turned on, and the two second switches 62 and the two third switches 63 are all turned off, that is, the first adsorption column 51 starts to receive the hydrogen from the first adsorption column 51. The adsorption module 3 outputs the hydrogen-helium mixed gas, and adsorbs the hydrogen in the hydrogen-helium mixed gas, and transports the generated high-purity helium to the collector. At this time, the heating belt 511 wrapped on the side wall of the first adsorption column 51 does not work, and the heating belt 511 wrapped on the side wall of the second adsorption column 52 is heated to 100-150°C, and high-purity helium is transported to the second adsorption column 52 through the second inflation pipeline 54, so that the hydrogen absorbed in the second adsorption column 52 is output to the outside through the second gas outlet pipeline 56; when the first adsorption column 51 adsorbs the hydrogen in the hydrogen-helium mixed gas output from the first adsorption module 3 and is in a saturated state, the two first switches 61 and the two fourth switches 64 are all closed, and the two second switches 62 and the two fourth switches 64 are closed. All third switches 63 are turned on, that is, the second adsorption column 52 starts to receive the hydrogen-helium mixed gas output from the first adsorption module 3, and adsorbs gas impurities in the hydrogen-helium mixed gas, and transports the generated high-purity helium to the collector. At this time, the heating belt 511 wrapped on the side wall of the second adsorption column 52 does not work, and the heating belt 511 wrapped on the side wall of the first adsorption column 51 is heated to 100-150°C, and high-purity helium is transported to the first adsorption column 51 through the first inflation pipeline 53, so that the hydrogen absorbed in the first adsorption column 51 is output to the outside through the first outlet pipeline 55; and so on, the first adsorption column 51 and the second adsorption column 52 alternately receive the mixed gas output from the first adsorption module 3.

[0062] In a specific example, the first adsorption column 51 and the second adsorption column 52 in the first adsorption module 3 can both be MOFs adsorption columns. The MOFs adsorption columns are of many types and have strong functionality. They can have a large specific surface area and high porosity. They can show a large adsorption amount and good selective adsorption performance at room temperature. The open metal sites can be increased to improve its selective adsorption and the pore size can be adjusted by changing the length of the organic ligand. For example, the adsorbent in the MOFs adsorption column can add Cu-BTC, ZIF-67, ZIF-8 and UiO66 as adsorbents, and chemical substances can be added to the adsorbent according to actual conditions to effectively adsorb CH4 and N2 in the mixed gas. Of course, other adsorbents can also be added according to actual conditions to adjust the pore size and unsaturated metal sites of the material and optimize the adsorption and separation performance of the material to improve the adsorption of gas impurities.

[0063] The first adsorption column 51 and the second adsorption column 52 in the second adsorption module 4 are both hydrogen storage alloy adsorption columns, which can adsorb hydrogen in the received hydrogen-helium mixed gas, avoid the introduction of oxygen impurities by using a catalytic dehydrogenation device, and greatly improve the purity of the output helium. The hydrogen storage alloy in the hydrogen storage alloy adsorption column can be selected from a rare earth hydrogen storage alloy.

[0064] In practical applications, the first adsorption column 51 and the second adsorption column 52 are both stainless steel round adsorption columns, both ends of which are filled with a certain amount of quartz sand, and the middle is filled with granular adsorbent. The amount of adsorbent is determined according to factors such as the flow rate of the mixed gas and the type of adsorbent material. The adsorbent should be activated before use to maximize the adsorption efficiency of the adsorbent. After activation, the first adsorption column 51 and the second adsorption column 52 begin to enter a normal working state.

[0065] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A system for extracting helium, characterized in that: including a plurality of processing modules; Multiple processing modules include A pre-processing module is used to receive the mixed gas to be processed from the outside and pre-process the mixed gas to be processed; The membrane separation module is used to receive the mixed gas pretreated by the pretreatment module and remove some gas impurities in the mixed gas; at least one set of adsorption modules; The adsorption module comprises A first adsorption column and a second adsorption column arranged in parallel; The first adsorption column and the second adsorption column are configured to alternately receive the mixed gas output by the previous processing module and adsorb the remaining gas impurities in the received mixed gas.

2. The system for extracting helium according to claim 1, characterized in that The adsorption module has two groups arranged in series, namely a first adsorption module and a second adsorption module; The first adsorption column and the second adsorption column in the first adsorption module are respectively connected to the membrane separation module to alternately receive the mixed gas output by the membrane separation module to generate a hydrogen-helium mixed gas; The first adsorption column and the second adsorption column in the second adsorption module are respectively connected to the first adsorption module to alternately receive the hydrogen-helium mixed gas and adsorb hydrogen in the hydrogen-helium mixed gas to generate high-purity helium.

3. The system for extracting helium according to claim 2, characterized in that The first adsorption column and the second adsorption column in the first adsorption module are both MOFs adsorption columns; The first adsorption column and the second adsorption column in the second adsorption module are both hydrogen storage alloy adsorption columns.

4. The system for extracting helium according to claim 1, characterized in that The adsorption module further includes: a first gas filling pipeline and a second gas filling pipeline respectively connected to one end of the first adsorption column and one end of the second adsorption column, the first gas filling pipeline being used to deliver high-purity helium to the first adsorption column, and the second gas filling pipeline being used to deliver high-purity helium to the second adsorption column; A first gas outlet pipeline and a second gas outlet pipeline respectively connected to the other end of the first adsorption column and the other end of the second adsorption column; When the first gas filling pipeline delivers high-purity helium to the first adsorption column, gas impurities absorbed in the first adsorption column are output to the outside through the first gas outlet pipeline; When the second gas filling pipeline delivers high-purity helium to the second adsorption column, gas impurities absorbed in the second adsorption column are output to the outside through the second gas outlet pipeline.

5. The system for extracting helium according to claim 4, characterized in that The first adsorption column has two ends each provided with a first switch, and the second adsorption column has two ends each provided with a second switch; The first inflation pipeline comprises a first outlet, the first outlet is located between one of the first switches and the first adsorption column and is in communication with the first adsorption column; The second inflation pipeline includes a second outlet, the second outlet is located between one of the second switches and the second adsorption column and is in communication with the second adsorption column; The first gas outlet pipeline comprises a first inlet, the first inlet is located between the other first switch of the two and the first adsorption column and is in communication with the first adsorption column; The second air outlet pipeline comprises a second inlet, which is located between the other second switch and the second adsorption column and is communicated with the second adsorption column.

6. The system for extracting helium according to claim 5, characterized in that The first inflation pipeline and the first air outlet pipeline are respectively provided with a third switch, and the second inflation pipeline and the second air outlet pipeline are respectively provided with a fourth switch; When the first adsorption column is in an adsorption state, the first switch and the fourth switch are in an open state, and the second switch and the third switch are in a closed state; When the second adsorption column is in an adsorption state, the first switch and the fourth switch are in a closed state, and the second switch and the third switch are in an open state.

7. The system for extracting helium according to claim 1, characterized in that The membrane separation module comprises At least one primary membrane separator communicated with the pretreatment module and used to receive the mixed gas pretreated by the pretreatment module; a secondary membrane separator connected to the primary membrane separator via a compressor and used to receive the mixed gas outputted from the primary membrane separator; The adsorption module is communicated with the secondary membrane separator and receives the mixed gas output by the secondary membrane separator.

8. The system for extracting helium according to claim 7, characterized in that The tail gas outputted from the secondary membrane separator is inputted into the primary membrane separator again through a circulation pipeline.

9. The system for extracting helium according to claim 1, characterized in that A preheater is arranged between the pretreatment module and the membrane separation module.

10. The system for extracting helium according to claim 1, characterized in that Heating belts are respectively arranged on the side walls of the first adsorption column and the second adsorption column.

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