Device for concentrating helium in natural gas containing carbon dioxide

Abstract

The utility model relates to the technical field of natural gas helium concentration, and particularly discloses a carbon dioxide-containing natural gas helium concentration device which comprises a gas inlet pipe, a primary membrane separation system, a carbon dioxide removal system, a secondary membrane separation system, a dehydrogenation unit, a methane and impurity removal system and a helium storage system which are connected in sequence, the air inlet pipe is connected with an outer conveying pipe; and the external conveying pipe is connected with the first-stage membrane separation system and the carbon dioxide removal system. According to the utility model, methane, ethane, nitrogen and hydrogen can be effectively removed, and finally helium with relatively high concentration is obtained.

Description

Technical Field

[0001] The utility model relates to the technical field of helium enrichment in natural gas, and more specifically to a device for enriching helium in natural gas containing carbon dioxide. Background Art

[0002] Helium has unique physical and chemical properties. As an important strategic resource, it has very important and irreplaceable uses in national defense, military industry, aerospace, scientific research, etc.

[0003] Helium exists in relatively high concentrations only in a few natural gas fields, with its volume content in natural gas ranging from 0 to 8%. Helium is present in very low concentrations in air (0.0005%) and has no industrial value for extraction. Currently, extraction from natural gas remains the primary industrial source of helium. However, the helium content of existing natural gas fields in my country is extremely low, generally less than 0.03%. my country imports large quantities of helium annually.

[0004] Recent exploration has found that the helium content in some wellhead natural gas is greater than 0.1%, but the carbon dioxide content is ≥4%. In view of the characteristics of this type of wellhead natural gas composition, it is necessary to develop a device that can recover precious rare gases during natural gas extraction. Utility Model Content

[0005] The technical problem to be solved by the utility model is to provide a device for enriching helium in natural gas containing carbon dioxide;

[0006] The solution adopted by the utility model to solve the technical problem is:

[0007] A helium enrichment device for natural gas containing carbon dioxide, comprising an air inlet pipe, a primary membrane separation system, a carbon dioxide removal system, a secondary membrane separation system, a dehydrogenation unit, a demethanization and impurity removal system, and a helium storage system connected in sequence;

[0008] The air inlet pipe is connected to an external transmission pipe; the external transmission pipe is connected to a primary membrane separation system and a carbon dioxide removal system.

[0009] In some possible embodiments, the primary membrane separation system includes a raw gas preheat exchanger, a raw gas heat exchanger, a water bath electric heater, and a primary membrane connected in sequence; the raw gas preheat exchanger is connected to the air inlet pipe and the external transmission pipe respectively; a circulation pipeline is set between the raw gas preheat exchanger and the primary membrane; the raw gas heat exchanger, the water bath electric heater, and the primary membrane are respectively connected to the carbon dioxide removal system.

[0010] In some possible embodiments, the carbon dioxide removal system includes a pressure swing adsorption system 1 connected to the raw gas heat exchanger and the secondary membrane separation system respectively, a cooling system connected to the raw gas heat exchanger, a primary membrane permeate gas compressor connected to the cooling system and the primary membrane respectively, a vacuum pump 1 connected to the pressure swing adsorption system 1, and a desorption gas compressor connected to the vacuum pump 1 and the external transmission pipe respectively; a pipeline 1 is provided between the primary membrane and the primary membrane permeate gas compressor; the pressure swing adsorption system 1 is connected to the pipeline 1.

[0011] In some possible embodiments, the pressure swing adsorption system includes a pressure swing adsorption pre-heat exchanger, a separator, a pressure swing adsorption tower, and an outlet buffer tank connected in sequence; the pressure swing adsorption pre-heat exchanger is connected to the raw gas heat exchanger, and the pressure swing adsorption tower is respectively connected to a vacuum pump and a pipeline; the outlet buffer tank is connected to a secondary membrane separation system.

[0012] In some possible embodiments, the two-stage membrane separation system includes a two-stage membrane inlet compressor, an air cooler, and a two-stage membrane assembly connected in sequence;

[0013] The secondary membrane assembly includes a first secondary membrane section and a second secondary membrane section connected to the first secondary membrane section; the first secondary membrane section is connected to a dehydrogenation unit; and the second secondary membrane section is connected to an air inlet pipe and a pipeline 1, respectively.

[0014] In some possible embodiments, the dehydrogenation unit includes a dehydrogenation inlet permeate compressor, an air cooler 2, and a dehydrogenation system connected in sequence;

[0015] The dehydrogenation inlet permeate gas compressor is connected to the first stage of the secondary membrane;

[0016] The dehydrogenation system is connected to the demethanization and impurity system.

[0017] In some possible embodiments, the dehydrogenation system includes a first dehydrogenation reaction bed, a first separator, a second dehydrogenation reaction bed, and a second separator connected in sequence, and compressed air supply pipelines connected to the first separator and the second dehydrogenation reaction bed, respectively;

[0018] The second stage of the separator is connected to the demethanization and impurity system.

[0019] In some possible embodiments, the demethanization and impurity removal system includes an inlet heat exchanger, a second separator, a second pressure swing adsorption system, a buffer tank and a booster connected in sequence, and a second vacuum pump connected to the second pressure swing adsorption system and the buffer tank respectively; the booster is connected to pipeline one.

[0020] In some possible implementations, the second pressure swing adsorption system includes a second pressure swing adsorption tower connected to the second separator, and a product buffer tank connected to the second pressure swing adsorption tower and the helium storage system, respectively.

[0021] In some possible implementations, the helium storage system includes a product gas compressor connected to the second pressure swing adsorption system and a mobile helium container connected to the product gas compressor.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The utility model sets up a first-level membrane separation system to obtain high-content carbon dioxide-containing helium permeation natural gas, and the non-permeation gas returns to the fuel gas system for fuel or other use;

[0024] The utility model uses a carbon dioxide removal system to remove carbon dioxide from helium-containing permeated natural gas through pressure swing adsorption to obtain low-concentration helium;

[0025] The utility model obtains a certain concentration of permeate gas (natural gas containing helium) by setting a two-stage membrane separation system for pressurization, cooling and separation;

[0026] The utility model uses a dehydrogenation unit to pressurize, cool and dehydrogenate permeate gas (natural gas containing helium) of a certain concentration to remove the enriched hydrogen.

[0027] The utility model separates the helium-containing natural gas after dehydrogenation by setting up a demethanization and impurity system, and finally obtains crude helium with a higher concentration;

[0028] The utility model fully utilizes the different molecular weights of methane, ethane, nitrogen, hydrogen, helium and the like in natural gas, adopts membrane separation to filter out most of the macromolecular media, adopts pressure swing adsorption technology to remove carbon dioxide and nitrogen and other impurity gases, and uses a dehydrogenation device to remove hydrogen, thereby achieving the purpose of extracting concentrated helium from natural gas with a relatively high carbon dioxide content (generally ≥4%), simplifying the existing low-temperature helium extraction process and reducing the demand for public works. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a working principle diagram of the utility model;

[0030] Figure 2 This is a schematic diagram of the connection relationship of the utility model;

[0031] Wherein: 100, air inlet pipe; 200, external transmission pipe; 1, primary membrane separation system; 11, feed gas preheat exchanger; 12, feed gas heat exchanger; 13, water bath electric heater; 14, primary membrane; 2, carbon dioxide removal system; 20, pipeline 1; 21, primary membrane permeate compressor; 22, cooling system; 23, pressure swing adsorption system 1; 231, pressure swing adsorption preheat exchanger; 232, separator 1; 233, pressure swing adsorption tower 1; 234, outlet buffer tank; 24, vacuum pump 1; 25, analytical gas compressor; 3, secondary membrane separation system; 31, secondary membrane inlet compressor; 32, air cooler 1; 33, secondary membrane assembly; 331. Secondary membrane section 1; 332. Secondary membrane section 2; 4. Dehydrogenation unit; 41. Dehydrogenation inlet permeate compressor; 42. Air cooler 2; 43. Dehydrogenation system; 431. Dehydrogenation reaction bed section 1; 432. Separator section 1; 433. Dehydrogenation reaction bed section 2; 434. Separator section 2; 435. Compressed air supply pipeline; 5. Demethanization and impurity system; 51. Inlet heat exchanger; 52. Separator 2; 53. Pressure swing adsorption system 2; 54. Product gas buffer tank; 55. Vacuum pump 2; 56. Booster; 57. Buffer tank; 6. Helium storage system; 61. Product gas compressor; 62. Mobile helium container. DETAILED DESCRIPTION

[0032] In this application, unless otherwise specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be interpreted broadly. For example, they can refer to fixed connections, removable connections, or integration; they can refer to direct connections or indirect connections through an intermediary; they can refer to internal communication between two components or interactions between two components. The terms "first," "second," and similar terms mentioned in this application do not denote any order, quantity, or importance; they are simply used to distinguish between different components. Similarly, terms such as "a" or "an" do not indicate a quantitative limitation; rather, they indicate the presence of at least one. In the implementation of this application, "and / or" describes an association relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists alone, A and B exist simultaneously, or B exists alone. In the description of the embodiments of this application, unless otherwise specified, "plurality" means two or more. For example, "plurality" refers to two or more positioning posts. Those skilled in the art will understand the specific meanings of these terms in this application based on the specific circumstances.

[0033] The utility model is described in detail below.

[0034] like Figure 1-Figure 2 As shown:

[0035] A device for enriching helium in natural gas containing carbon dioxide comprises an inlet pipe 100, a primary membrane separation system 1, a carbon dioxide removal system 2, a secondary membrane separation system 3, a dehydrogenation unit 4, a demethanization and impurity removal system 5, and a helium storage system 6, which are connected in sequence.

[0036] The air inlet pipe 100 is connected to an external transmission pipe 200 ; the external transmission pipe 200 is connected to the primary membrane separation system 1 and the carbon dioxide removal system 2 .

[0037] By setting a primary membrane separation system 1 connected to the air inlet pipe 100, the primary membrane separation system 1 processes the raw gas to achieve heating of the raw gas and concentration of helium by 7 to 10 times, thereby obtaining helium-containing permeate natural gas and non-permeate gas with a high content of carbon dioxide, wherein the non-permeate gas returns to the fuel gas system through the external transmission pipe 200 for fuel or other use, and the helium-containing permeate natural gas enters the carbon dioxide removal system 2 for processing, and the carbon dioxide is removed to less than 2% by pressure swing adsorption of the helium-containing permeate natural gas through the carbon dioxide removal system 2, thereby obtaining low-concentration helium, analytical gas, and effluent gas; wherein the analytical gas is transmitted through the external transmission pipe 200, the low-concentration helium enters the secondary membrane separation system 3, and the effluent gas enters the primary membrane permeate gas compressor 21; the low-concentration helium passes through the secondary membrane After the separation system 3, pressurization, cooling, and membrane separation are performed to obtain a certain concentration of permeate gas (helium-containing natural gas). Specifically, the secondary membrane separation system 3 will concentrate the helium to 50%. The permeate gas (helium-containing natural gas) with a certain concentration will enter the dehydrogenation unit 4, where it will be pressurized, cooled, and dehydrogenated to remove the enriched hydrogen. Specifically, the hydrogen is removed to ≤1%. The helium-containing natural gas after dehydrogenation enters the demethanization and impurity removal system 5 for pressure swing adsorption treatment to ultimately obtain a higher concentration of crude helium. Specifically, the crude helium contains ≥98% helium, ≤0.1% methane, ≤40 ppm carbon dioxide, and ≤1% hydrogen. The crude helium enters the helium storage system 6 for storage. The stored crude helium can be centrally refined at a helium refining plant, reducing on-site space and significantly reducing refining costs.

[0038] The specific working steps are:

[0039] In step 1, natural gas from an upstream device contains approximately 0.1% helium and 4% carbon dioxide. After processing through an inlet pipe 100, it enters a primary membrane separation system 1 to produce high-carbon dioxide content helium-containing permeate natural gas and non-permeate gas. The non-permeate gas is returned to the fuel gas system via an external transmission pipe 200 for use as fuel or for other purposes. The high-carbon dioxide content helium-containing permeate natural gas is processed in a carbon dioxide removal system 2 to remove carbon dioxide and produce low-concentration helium.

[0040] In step 2, the low-concentration helium gas enters the secondary membrane separation system 3, where it is pressurized, cooled, and separated to obtain permeate gas (natural gas containing helium) and non-permeate gas of a certain concentration. The non-permeate gas enters the secondary membrane second section 332 and then returns to the front end.

[0041] In step 3, the permeate gas (natural gas containing helium) with a certain concentration enters the dehydrogenation unit 4, where it is pressurized and cooled to remove the hydrogen enriched in the gas.

[0042] In step 4, the helium-containing natural gas after dehydrogenation is further subjected to a demethanization and impurity removal system 5 to obtain crude helium gas with a higher concentration.

[0043] Step 5: The crude helium is pressurized by the product gas and then stored in the helium storage system.

[0044] A high-concentration crude helium gas can be obtained by a helium concentration and extraction device from natural gas containing carbon dioxide at the wellhead. The crude helium gas can be transported to a helium refining plant for centralized refining, which can greatly improve the efficiency of helium refining and reduce the refining cost of a single well station.

[0045] In some possible embodiments, in order to effectively process the raw gas through the primary membrane separation system 1, thereby obtaining helium-containing permeate natural gas and non-permeate gas with a high carbon dioxide content;

[0046] The primary membrane separation system 1 includes a raw gas preheat exchanger 11, a raw gas heat exchanger 12, a water bath electric heater 13, and a primary membrane 14 connected in sequence; the raw gas preheat exchanger 11 is connected to the air inlet pipe 100 and the external transmission pipe 200 respectively; a circulation pipeline is set between the raw gas preheat exchanger 11 and the primary membrane 14; the raw gas heat exchanger 12, the water bath electric heater 13, and the primary membrane 14 are respectively connected to the carbon dioxide removal system 2.

[0047] The raw gas passes through the gas inlet pipe 100 and enters the raw gas preheat exchanger 11, the raw gas heat exchanger 12, the water bath electric heater 13, and the primary membrane 14 for treatment. The primary membrane 14 separates the helium-containing permeate natural gas with a high carbon dioxide content and the non-permeate gas. The non-permeate gas is returned to the raw gas preheat exchanger 11, and the helium-containing permeate natural gas with a high carbon dioxide content enters the carbon dioxide removal system 2.

[0048] The feed gas preheat exchanger 11 is used to recover the heat of the retentate gas from the primary membrane 14;

[0049] The feed gas heat exchanger 12 is used to recover heat from the carbon dioxide removal system 2;

[0050] The water bath electric heater 13 is used for heating and supplementing the temperature adjustment when the raw gas temperature is not high enough.

[0051] Working principle of raw gas in the primary membrane separation system 1:

[0052] When a natural gas mixture consisting of methane, ethane, nitrogen, helium, and carbon dioxide passes through a membrane, the different solubilities and diffusion coefficients of the various gases in the membrane result in different relative permeation rates for the different gases. Due to the pressure difference across the membrane, gases with relatively high permeation rates, such as carbon dioxide, hydrogen, and XAI, preferentially permeate the membrane and are enriched as permeate gas. Gases with relatively slow permeation rates, such as methane, nitrogen, carbon monoxide, and hydrocarbons, are enriched on the stagnant side of the membrane as retentate gas, thus achieving the purpose of separating mixed gases.

[0053] In some possible embodiments, in order to effectively remove carbon dioxide and obtain low-concentration helium through the carbon dioxide removal system 2;

[0054] The carbon dioxide removal system 2 includes a pressure swing adsorption system 23 connected to the raw gas heat exchanger 12 and the secondary membrane separation system 3 respectively, a cooling system 22 connected to the raw gas heat exchanger 12, a primary membrane permeate gas compressor 21 connected to the cooling system 22 and the primary membrane 14 respectively, a vacuum pump 24 connected to the pressure swing adsorption system 23, and a desorption gas compressor 25 connected to the vacuum pump 24 and the external transmission pipe 200 respectively; a pipeline 20 is provided between the primary membrane 14 and the primary membrane permeate gas compressor 21; the pressure swing adsorption system 23 is connected to the pipeline 20.

[0055] In some possible embodiments, in order to effectively remove carbon dioxide, the pressure swing adsorption system 23 includes a pressure swing adsorption pre-heat exchanger 231, a separator 232, a pressure swing adsorption tower 233, and an outlet buffer tank 234 connected in sequence; the pressure swing adsorption pre-heat exchanger 231 is connected to the raw gas heat exchanger 12, and the pressure swing adsorption tower 233 is respectively connected to the vacuum pump 24 and the pipeline 20; the outlet buffer tank 234 is connected to the secondary membrane separation system 3.

[0056] The pre-pressure swing adsorption heat exchanger 231 is connected to the raw gas heat exchanger 12, the separator 232 is respectively connected to the pre-pressure swing adsorption heat exchanger 231 and the pressure swing adsorption tower 233, the outlet buffer tank 234 is connected to the top of the pressure swing adsorption tower 233, and the pressure swing adsorption tower 233 is connected in parallel in multiple groups; after the carbon dioxide is removed by the pressure swing adsorption tower 233, the low-concentration helium obtained will enter the secondary membrane separation system 3 through the outlet buffer tank 234.

[0057] The pressure swing adsorption system 23 adopts a multi-tower process, which is conducive to the smooth operation of the device without increasing the operational complexity, and the number of towers can be adjusted according to the carbon dioxide content;

[0058] The helium-containing permeated natural gas with a high carbon dioxide content separated by the primary membrane 14 enters the primary membrane permeate gas compressor 21 through pipeline 20 for pressurization, and then enters the raw gas ventilator to recover the heat of the primary membrane permeate gas compressor 21 after cooling treatment by the cooling system 22, and then enters the pressure swing adsorption system 23 to remove carbon dioxide, and obtains low-concentration helium to enter the secondary membrane separation system 3; the decarbonized gas treated by the pressure swing adsorption system 23 enters pipeline 20 and is pressurized by the primary membrane permeate gas compressor 21, and the desorption gas of the pressure swing adsorption system 23 is compressed by the desorption gas compressor 25 through the vacuum pump 24 and enters the external transmission pipeline 200.

[0059] In some possible embodiments, in order to effectively dehydrogenate the low-concentration helium through the secondary membrane separation system 3 and obtain a certain concentration of permeate gas (helium-containing natural gas); the secondary membrane separation system 3 includes a secondary membrane inlet compressor 31, an air cooler 32, and a secondary membrane assembly 33 connected in sequence;

[0060] The secondary membrane assembly 33 includes a first secondary membrane section 331 and a second secondary membrane section 332 connected to the first secondary membrane section 331 ; the first secondary membrane section 331 is connected to the dehydrogenation unit 4 ; the second secondary membrane section 332 is connected to the air inlet pipe 100 and the pipeline 1 20 respectively.

[0061] The low-concentration helium gas enters the secondary membrane inlet compressor 31 through the outlet buffer tank 234 for pressurization, and then enters the secondary membrane separation system 3 after being cooled by the air cooler 32. After being processed in sequence by the secondary membrane section 1 331 and the secondary membrane section 2 332, a certain concentration of permeate gas (natural gas containing helium) is obtained. The permeate gas (natural gas containing helium) of a certain concentration passes through the secondary membrane section 1 331 and enters the dehydrogenation unit 4. The retentate gas separated by the secondary membrane separation system 3 passes through the secondary membrane section 2 332 and enters the pipeline 1 20 and the air inlet pipe 100. Specifically, the retentate gas of the secondary membrane section 2 enters the air inlet pipe 100, and the permeate gas of the secondary membrane section 2 enters the pipeline 120.

[0062] In some possible embodiments, in order to effectively achieve dehydrogenation treatment of permeate gas (natural gas containing helium) of a certain concentration, the dehydrogenation unit 4 includes a dehydrogenation inlet permeate gas compressor 41, an air cooler 2 42, and a dehydrogenation system 43 connected in sequence;

[0063] The dehydrogenation inlet permeate gas compressor 41 is connected to the second stage membrane 331;

[0064] The dehydrogenation system 43 is connected to the demethanization and impurity removal system 5 .

[0065] After the permeate gas (natural gas containing helium) of a certain concentration passes through the secondary membrane stage 331 and enters the dehydrogenation unit 4, it is pressurized by the dehydrogenation inlet permeate gas compressor 41, cooled by the air cooler 42, and then enters the dehydrogenation system 43 for dehydrogenation.

[0066] In some possible embodiments, in order to effectively achieve dehydrogenation treatment of permeate gas (helium-containing natural gas) of a certain concentration, the dehydrogenation system 43 includes a first dehydrogenation reaction bed 431, a first separator 432, a second dehydrogenation reaction bed 433, and a second separator 434, which are connected in sequence, and a compressed air supply pipeline 435 connected to the first separator 432 and the second dehydrogenation reaction bed 433, respectively.

[0067] The second separator section 434 is connected to the demethanization and impurity removal system 5 .

[0068] The permeate gas (natural gas containing helium) with a certain concentration is sequentially connected to the dehydrogenation reaction bed section 1 431, the separator section 1 432, the dehydrogenation reaction bed section 2 433 and the separator section 2 434 to achieve dehydrogenation treatment, and the compressed air supply pipeline 435 transports compressed gas to the dehydrogenation system 43 according to the treatment requirements.

[0069] In some possible embodiments, in order to effectively remove methane and impurities from the helium-containing gas after dehydrogenation treatment through the demethanization and impurity removal system 5, the impurities here include trace gases such as nitrogen, oxygen, and ethane; the demethanization and impurity removal system 5 includes an inlet heat exchanger 51, a separator 52, a pressure swing adsorption system 53, a buffer tank 57 and a booster 56 connected in sequence, and a vacuum pump 55 connected to the pressure swing adsorption system 53 and the buffer tank 57 respectively; the booster 56 is connected to the pipeline 20.

[0070] After dehydrogenation, the helium-containing natural gas passes through the secondary separator and enters the inlet heat exchanger 51 for heat exchange treatment. After passing through the second separator 52, it enters the second pressure swing adsorption system 53, where methane and impurities are removed to obtain a higher concentration of crude helium. The desorption gas separated in the second pressure swing adsorption system 53 can be passed through the second vacuum pump 55 or directly into the buffer tank 57, the booster 56, and the pipeline 20 in sequence.

[0071] In some possible implementations, the second pressure swing adsorption system 53 includes a second pressure swing adsorption tower connected to the second separator 52 , and a product gas buffer tank 54 connected to the second pressure swing adsorption tower and the helium storage system 6 , respectively.

[0072] The crude helium with a higher concentration passes through the product gas buffer tank 54 and enters the helium storage system 6 for storage. The pressure swing adsorption tower 2 can be multiple groups. Specifically, the pressure swing adsorption system 2 53 adopts a multi-tower process, which is conducive to the smooth operation of the device without increasing the complexity of the operation, and the number of towers can be adjusted according to the content of methane and impurities.

[0073] In some possible implementations, the helium storage system 6 includes a product gas compressor 61 connected to the pressure swing adsorption system 2 53 , and a mobile helium container 62 connected to the product gas compressor 61 .

[0074] The crude helium gas is pressurized by the product gas compressor 61 and then enters the mobile helium container cabinet 62 for storage.

[0075] The present invention is not limited to the aforementioned specific embodiments, but extends to any new features or any new combination disclosed in this specification, as well as any new method or process steps or any new combination disclosed.

Claims

1. A device for enriching helium in natural gas containing carbon dioxide, characterized in that: It includes an air inlet pipe, a primary membrane separation system, a carbon dioxide removal system, a secondary membrane separation system, a dehydrogenation unit, a demethanization and impurity removal system, and a helium storage system connected in sequence; The air inlet pipe is connected to an external transmission pipe; the external transmission pipe is connected to a primary membrane separation system and a carbon dioxide removal system.

2. The device for enriching helium in natural gas containing carbon dioxide according to claim 1, characterized in that: The primary membrane separation system includes a raw gas preheat exchanger, a raw gas heat exchanger, a water bath electric heater, and a primary membrane connected in sequence; the raw gas preheat exchanger is connected to the air inlet pipe and the external transmission pipe respectively; a circulation pipeline is set between the raw gas preheat exchanger and the primary membrane; the raw gas heat exchanger, the water bath electric heater, and the primary membrane are respectively connected to the carbon dioxide removal system.

3. The device for enriching helium in natural gas containing carbon dioxide according to claim 2, characterized in that: The carbon dioxide removal system includes a pressure swing adsorption system 1 connected to the raw gas heat exchanger and the secondary membrane separation system respectively, a cooling system connected to the raw gas heat exchanger, a primary membrane permeate gas compressor connected to the cooling system and the primary membrane respectively, a vacuum pump 1 connected to the pressure swing adsorption system 1, and a desorption gas compressor connected to the vacuum pump 1 and the external transmission pipe respectively; a pipeline 1 is provided between the primary membrane and the primary membrane permeate gas compressor; the pressure swing adsorption system 1 is connected to the pipeline 1.

4. The device for enriching helium in natural gas containing carbon dioxide according to claim 3, characterized in that: The pressure swing adsorption system 1 includes a pressure swing adsorption pre-heat exchanger, a separator 1, a pressure swing adsorption tower 1, and an outlet buffer tank connected in sequence; the pressure swing adsorption pre-heat exchanger is connected to the raw gas heat exchanger, and the pressure swing adsorption tower 1 is respectively connected to a vacuum pump 1 and a pipeline 1; the outlet buffer tank is connected to a secondary membrane separation system.

5. The device for enriching helium in natural gas containing carbon dioxide according to claim 3, characterized in that: The two-stage membrane separation system comprises a two-stage membrane inlet compressor, an air cooler first and a two-stage membrane assembly connected in sequence; The secondary membrane assembly includes a first secondary membrane section and a second secondary membrane section connected to the first secondary membrane section; the first secondary membrane section is connected to a dehydrogenation unit; and the second secondary membrane section is connected to an air inlet pipe and a pipeline 1, respectively.

6. The device for enriching helium in natural gas containing carbon dioxide according to claim 5, characterized in that: The dehydrogenation unit comprises a dehydrogenation inlet permeate compressor, an air cooler 2, and a dehydrogenation system connected in sequence; The dehydrogenation inlet permeate gas compressor is connected to the first stage of the secondary membrane; The dehydrogenation system is connected to the demethanization and impurity system.

7. The device for enriching helium in natural gas containing carbon dioxide according to claim 6, characterized in that: The dehydrogenation system includes a first dehydrogenation reaction bed, a first separator, a second dehydrogenation reaction bed and a second separator connected in sequence, and compressed air supply pipelines connected to the first separator and the second dehydrogenation reaction bed respectively; The second stage of the separator is connected to the demethanization and impurity system.

8. The device for enriching helium in natural gas containing carbon dioxide according to claim 5, characterized in that: The demethanization and impurity removal system includes an inlet heat exchanger, a second separator, a second pressure swing adsorption system, a buffer tank and a booster connected in sequence, and a second vacuum pump connected to the second pressure swing adsorption system and the buffer tank respectively; the booster is connected to the first pipeline.

9. The device for enriching helium in natural gas containing carbon dioxide according to claim 8, characterized in that: The second pressure swing adsorption system includes a second pressure swing adsorption tower connected to the second separator, and a product buffer tank connected to the second pressure swing adsorption tower and the helium storage system respectively.

10. The device for enriching helium in natural gas containing carbon dioxide according to claim 8, characterized in that: The helium storage system includes a product gas compressor connected to the second pressure swing adsorption system and a mobile helium container cabinet connected to the product gas compressor.

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