A natural gas vtsa decarbonization pilot plant device without greenhouse gas emission and a working method thereof

Abstract

A natural gas VTSA decarburization pilot plant device without greenhouse gas emission and a working method thereof belong to the technical field of natural gas experiment. In order to solve the problems of raw material gas waste and environmental pollution in the natural gas experiment process, the application comprises a raw material gas mixing tank, a purified gas storage tank, a desorption gas storage tank, a purified gas and desorption gas mixing tank and an adsorption and desorption tower, the raw material gas mixing tank is connected with a raw material gas compressor, a desorption gas buffer tank, a CO2 gas cylinder, a CH4 gas cylinder, a CNG station pipeline and a purified gas buffer tank through pipelines respectively, the raw material gas compressor is connected with a raw material gas buffer tank through a pipeline, the raw material gas buffer tank is connected with a gas inlet at the bottom of the adsorption and desorption tower and a vacuum pump through pipelines respectively, the vacuum pump is connected with a gas outlet of the adsorption and desorption tower and the desorption gas storage tank through pipelines respectively, a purified gas outlet at the top of the adsorption and desorption tower is connected with the purified gas storage tank through a pipeline, and the purified gas storage tank is connected with a purified gas separator. The application does not waste raw material gas.

Description

Technical Field

[0001] This invention belongs to the field of natural gas experimental technology, specifically relating to a pilot-scale experimental device for natural gas VTSA decarbonization without greenhouse gas emissions and its working method. Background Technology

[0002] In actual natural gas production, most processes undergo experimental research before being put into production to provide a reference for actual production. Currently, during the experimental process, most processes use a specific ratio of pure CO2 and pure CH4 as feedstock gas. After the experiment, the purified CH4 gas is directly vented or burned, while the desorbed gas is vented, resulting in waste of feedstock gas and environmental pollution. Summary of the Invention

[0003] The problem this invention aims to solve is the waste of raw material gas and environmental pollution during natural gas experiments. It proposes a pilot-scale experimental device for natural gas VTSA decarbonization without greenhouse gas emissions and its working method.

[0004] A pilot-scale natural gas VTSA decarbonization experimental device with no greenhouse gas emissions includes a feed gas mixing tank, a purified gas storage tank, a desorbed gas storage tank, a purified gas and desorbed gas mixing tank, and an adsorption-desorption tower.

[0005] The raw gas mixing tank is connected to the raw gas compressor, desorption gas buffer tank, CO2 cylinder, CH4 cylinder, CNG station pipeline, and purified gas buffer tank via pipelines.

[0006] The raw material gas compressor is connected to the raw material gas buffer tank via pipeline. The raw material gas buffer tank is connected to the gas inlet at the bottom of the adsorption-desorption tower and the vacuum pump via pipeline. The vacuum pump is connected to the gas outlet at the bottom of the adsorption-desorption tower and the desorbed gas storage tank via pipeline. The purified gas outlet at the top of the adsorption-desorption tower is connected to the purified gas storage tank via pipeline. The purified gas storage tank is connected to the purified gas separator.

[0007] The desorbed gas storage tank is connected to the desorbed gas separator via a pipeline;

[0008] The purified gas separator is connected to the purified gas and desorbed gas mixing tank, the purified gas buffer tank, and the desorbed gas separator via pipelines; the desorbed gas separator is connected to the desorbed gas buffer tank via pipelines.

[0009] The purified gas and desorbed gas mixing tank is connected to the purified gas and desorbed gas mixing compressor via pipeline. The purified gas and desorbed gas mixing compressor is connected to the purified gas and desorbed gas mixing heat exchanger via pipeline. The purified gas and desorbed gas mixing heat exchanger is connected to the high-purity gas cylinder and the CNG station pipeline via pipeline.

[0010] Furthermore, the CH4 cylinder, CO2 cylinder, purified gas buffer tank, and desorption gas buffer tank constitute a raw material gas component adjustment system, with the CH4 cylinder and purified gas buffer tank connected, and the CO2 cylinder and desorption gas buffer tank connected.

[0011] Furthermore, a heat-conducting oil heater is provided on the outside of the adsorption-desorption tower.

[0012] Furthermore, each pipeline is equipped with a regulating valve.

[0013] Furthermore, pressure and temperature measuring instruments are installed on the raw gas mixing tank, the desorbed gas storage tank, the purified gas and desorbed gas mixing tank, and the adsorption-desorption tower.

[0014] Furthermore, the raw material gas mixing tank, the purified gas storage tank, the desorbed gas storage tank, and the purified gas and desorbed gas mixing tank are equipped with sampling ports.

[0015] Furthermore, depending on the different experimental research objectives, different proportions of raw material gas are prepared in the raw material gas mixing tank.

[0016] A pilot-scale experimental method for natural gas VTSA decarbonization without greenhouse gas emissions, based on the aforementioned pilot-scale experimental apparatus for natural gas VTSA decarbonization without greenhouse gas emissions, includes the following steps:

[0017] S1. At the start of the experiment, based on the ratio of CO2 to CH4 in the pipeline natural gas, gas is supplied to the raw material gas mixing tank through CH4 gas cylinder or CO2 gas cylinder, gas is supplied to the purified gas buffer tank through CH4 gas cylinder, and gas is supplied to the desorption gas buffer tank through CO2 gas cylinder, so that the raw material gas ratio meets the experimental requirements.

[0018] S2. The raw material gas prepared in step S1 is pressurized by a raw material gas compressor to meet the raw material gas inlet pressure requirement of 4.0–4.5 MPa, and coordinated with the regulating valve at the top of the adsorption-desorption tower to ensure the flow rate of the adsorption-desorption tower is 250–300 m³ / h. 3 The requirements are: / h and pressure of 3.5–4.0 MPa;

[0019] S3. When the CH4 content in the purified gas buffer tank is not less than 99%, and the CO2 content in the desorption gas buffer tank is higher than that in the raw gas, shut off the CH4 and CO2 cylinders. Then, supply high-purity CH4 from the purified gas buffer tank or high-purity CO2 from the desorption gas buffer tank, respectively. Adjust the raw gas ratio to conduct a natural gas decarbonization experiment. The formula for calculating the gas ratio is:

[0020]

[0021] Where C represents the CO2 content of the raw gas, C P C represents the CO2 content of the pipeline gas.S For purified gas or CH4 cylinders, the CH4 content, C D For desorption gas or CO2 content in CO2 cylinders, F P F represents the gas flow rate in the pipeline. S For the flow rate of purified gas or CH4 cylinders, F D For desorption gas or CO2 cylinder flow rate;

[0022] S4. When the natural gas decarbonization experiment in step S3 is stable, the purified gas from the adsorption-desorption tower is depressurized by the regulating valve and enters the purified gas storage tank. Then the purified gas is processed by the purified gas separator to remove impurities from the purified gas and obtain the processed purified gas.

[0023] S5. When the CH4 content of the purified gas in step S4 is no higher than 50ppm and the CH4 content is no higher than 3% when the purified gas is used as pipeline gas, close the raw material gas inlet regulating valve and the purified gas outlet regulating valve of the adsorption-desorption tower, open the heat transfer oil heater, and heat the outer wall jacket of the adsorption-desorption tower until the CO2 content of the desorbed gas no longer increases.

[0024] S6. Based on the desorption gas generated by the adsorption-desorption tower in step S5, the desorption gas in the adsorption-desorption tower is extracted by a vacuum pump and introduced into the desorption gas storage tank. Then, the desorption gas is processed by the desorption gas separator to remove impurities in the desorption gas and obtain the processed desorption gas.

[0025] S7. The purified gas obtained in step S4 and the desorbed gas obtained in step S6 are introduced into the purified gas and desorbed gas mixing tank. The ratio of the mixed gas is adjusted by controlling the flow rate of the purified gas and the desorbed gas to obtain a mixed gas. The mixed gas is pressurized by the purified gas and desorbed gas mixing gas compressor, and then heated by the purified gas and desorbed gas mixing gas heat exchanger before being introduced into the downstream of the CNG station pipeline.

[0026] Furthermore, in step S7, the gas content inside the test purification gas and desorption gas mixing tank is collected through the sampling port to ensure that the CO2 content in the mixed gas is lower than the CO2 content in the CNG station pipeline.

[0027] Furthermore, when the purified gas obtained in step S4 and the desorbed gas obtained in step S6 are not reinjected into the pipeline gas, the following processes are performed respectively:

[0028] The treated purified gas is introduced into a purified gas and desorbed gas mixing tank, and then pressurized by a purified gas and desorbed gas mixing compressor before being introduced into a CH4 gas cylinder.

[0029] The treated desorbed gas is fed into a mixture tank of purified gas and desorbed gas, and then pressurized by a compressor of the mixture of purified gas and desorbed gas before being fed into a CO2 cylinder.

[0030] The beneficial effects of this invention are:

[0031] The present invention discloses a pilot-scale experimental device for decarbonization of natural gas VTSA without greenhouse gas emissions. The process of taking raw gas from CNG station pipelines and reinjecting purified gas and desorbed gas during the experiment can greatly save experimental costs, with almost no greenhouse gas emissions, reducing environmental pollution to zero. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the structure of a pilot-scale experimental device for decarbonization of natural gas VTSA without greenhouse gas emissions, as described in this invention. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the invention and are not intended to limit the invention; that is, the described specific embodiments are merely a part of the embodiments of the invention, and not all of them. The components of the specific embodiments of the invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations, and the invention may also have other embodiments.

[0034] Therefore, the following detailed description of specific embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected specific embodiments of the invention. All other specific embodiments obtained by those skilled in the art based on these specific embodiments without inventive effort are within the scope of protection of this invention.

[0035] To further understand the invention's content, features, and effects, the following specific embodiments are provided, along with accompanying drawings. Figure 1 Detailed explanation is as follows: Specific implementation method one:

[0037] A pilot-scale test apparatus for natural gas VTSA decarbonization without greenhouse gas emissions includes a feed gas mixing tank 1, a purified gas storage tank 2, a desorbed gas storage tank 3, a purified gas and desorbed gas mixing tank 4, and an adsorption-desorption tower 5.

[0038] The raw gas mixing tank 1 is connected to the raw gas compressor 6, the desorption gas buffer tank 11, the CO2 cylinder 12, the CH4 cylinder 13, the CNG station pipeline 14, and the purified gas buffer tank 15 via pipelines.

[0039] The raw material gas compressor 6 is connected to the raw material gas buffer tank 7 via pipelines. The raw material gas buffer tank 7 is connected to the gas inlet at the bottom of the adsorption-desorption tower 5 and the vacuum pump 8 via pipelines. The vacuum pump 8 is connected to the gas outlet at the bottom of the adsorption-desorption tower 5 and the desorption gas storage tank 3 via pipelines. The purified gas outlet at the top of the adsorption-desorption tower 5 is connected to the purified gas storage tank 2 via pipelines. The purified gas storage tank 2 is connected to the purified gas separator 9.

[0040] The desorbed gas storage tank 3 is connected to the desorbed gas separator 10 via a pipeline;

[0041] The purified gas separator 9 is connected to the purified gas and desorbed gas mixing tank 4, the purified gas buffer tank 15, and the desorbed gas separator 10 via pipelines; the desorbed gas separator 10 is connected to the desorbed gas buffer tank 11 via pipelines.

[0042] The purified gas and desorbed gas mixing tank 4 is connected to the purified gas and desorbed gas mixing compressor 16 via a pipeline. The purified gas and desorbed gas mixing compressor 16 is connected to the purified gas and desorbed gas mixing heat exchanger 17 via a pipeline. The purified gas and desorbed gas mixing heat exchanger 17 is connected to the high-purity gas cylinder 18 and the CNG station pipeline 14 via pipelines respectively.

[0043] Furthermore, the CH4 cylinder 13, CO2 cylinder 12, purified gas buffer tank 15, and desorption gas buffer tank 11 constitute a raw material gas component adjustment system. The CH4 cylinder 13 and purified gas buffer tank 15 are connected, and the CO2 cylinder 12 and desorption gas buffer tank 11 are connected.

[0044] Furthermore, a heat transfer oil heater 22 is provided on the outside of the adsorption-desorption tower 5.

[0045] Furthermore, each pipeline is equipped with a regulating valve 19.

[0046] Furthermore, pressure detection instruments 20 and temperature detection instruments 21 are installed on the raw material gas mixing tank 1, the desorbed gas storage tank 3, the purified gas and desorbed gas mixing tank 4, and the adsorption-desorption tower 5.

[0047] Furthermore, sampling ports are provided on the raw material gas mixing tank 1, the purified gas storage tank 2, the desorbed gas storage tank 3, and the purified gas and desorbed gas mixing tank 4.

[0048] Furthermore, depending on the different experimental research objectives, different proportions of raw material gas are prepared in the raw material gas mixing tank 1. Specific Implementation Method Two:

[0050] A pilot-scale experimental method for natural gas VTSA decarbonization without greenhouse gas emissions, based on the natural gas VTSA decarbonization pilot-scale experimental apparatus described in Specific Embodiment 1, includes the following steps:

[0051] S1. At the start of the experiment, based on the ratio of CO2 to CH4 in the pipeline natural gas, gas is supplied to the raw material gas mixing tank through CH4 gas cylinder or CO2 gas cylinder, gas is supplied to the purified gas buffer tank through CH4 gas cylinder, and gas is supplied to the desorption gas buffer tank through CO2 gas cylinder, so that the raw material gas ratio meets the experimental requirements.

[0052] S2. The raw material gas prepared in step S1 is pressurized by a raw material gas compressor to meet the raw material gas inlet pressure requirement of 4.0–4.5 MPa, and coordinated with the regulating valve at the top of the adsorption-desorption tower to ensure the flow rate of the adsorption-desorption tower is 250–300 m³ / h. 3 The requirements are: / h and pressure of 3.5–4.0 MPa;

[0053] S3. When the CH4 content in the purified gas buffer tank is not less than 99%, and the CO2 content in the desorption gas buffer tank is higher than that in the raw gas, shut off the CH4 and CO2 cylinders. Then, supply high-purity CH4 from the purified gas buffer tank or high-purity CO2 from the desorption gas buffer tank, respectively. Adjust the raw gas ratio to conduct a natural gas decarbonization experiment. The formula for calculating the gas ratio is:

[0054]

[0055] Where C represents the CO2 content of the raw gas, C P C represents the CO2 content of the pipeline gas. S For purified gas or CH4 cylinders, the CH4 content, C D For desorption gas or CO2 content in CO2 cylinders, F P F represents the gas flow rate in the pipeline. S For the flow rate of purified gas or CH4 cylinders, F D For desorption gas or CO2 cylinder flow rate;

[0056] S4. When the natural gas decarbonization experiment in step S3 is stable, the purified gas from the adsorption-desorption tower is depressurized by the regulating valve and enters the purified gas storage tank. Then the purified gas is processed by the purified gas separator to remove impurities from the purified gas and obtain the processed purified gas.

[0057] S5. When the CH4 content of the purified gas in step S4 is no higher than 50ppm and the CH4 content is no higher than 3% when the purified gas is used as pipeline gas, close the raw material gas inlet regulating valve and the purified gas outlet regulating valve of the adsorption-desorption tower, open the heat transfer oil heater, and heat the outer wall jacket of the adsorption-desorption tower until the CO2 content of the desorbed gas no longer increases.

[0058] S6. Based on the desorption gas generated by the adsorption-desorption tower in step S5, the desorption gas in the adsorption-desorption tower is extracted by a vacuum pump and introduced into the desorption gas storage tank. Then, the desorption gas is processed by the desorption gas separator to remove impurities in the desorption gas and obtain the processed desorption gas.

[0059] S7. The purified gas obtained in step S4 and the desorbed gas obtained in step S6 are introduced into the purified gas and desorbed gas mixing tank. The ratio of the mixed gas is adjusted by controlling the flow rate of the purified gas and the desorbed gas to obtain a mixed gas. The mixed gas is pressurized by the purified gas and desorbed gas mixing gas compressor, and then heated by the purified gas and desorbed gas mixing gas heat exchanger before being introduced into the downstream of the CNG station pipeline.

[0060] Furthermore, in step S7, the gas content inside the test purification gas and desorption gas mixing tank is collected through the sampling port to ensure that the CO2 content in the mixed gas is lower than the CO2 content in the CNG station pipeline.

[0061] Furthermore, when the purified gas obtained in step S4 and the desorbed gas obtained in step S6 are not reinjected into the pipeline gas, the following processes are performed respectively:

[0062] The treated purified gas is introduced into a purified gas and desorbed gas mixing tank, and then pressurized by a purified gas and desorbed gas mixing compressor before being introduced into a CH4 gas cylinder.

[0063] The treated desorbed gas is fed into a mixture tank of purified gas and desorbed gas, and then pressurized by a compressor of the mixture of purified gas and desorbed gas before being fed into a CO2 cylinder.

[0064] It should be noted that relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0065] Although this application has been described above with reference to specific embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of this application. In particular, as long as there is no structural conflict, the features in the specific embodiments disclosed in this application can be combined with each other in any way. The lack of an exhaustive description of these combinations in this specification is merely for the sake of brevity and resource conservation. Therefore, this application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A pilot-scale experimental apparatus for natural gas VTSA decarbonization without greenhouse gas emissions, characterized in that, It includes a raw gas mixing tank (1), a purified gas storage tank (2), a desorbed gas storage tank (3), a purified gas and desorbed gas mixing tank (4), and an adsorption-desorption tower (5). The raw gas mixing tank (1) is connected to the raw gas compressor (6), the desorption gas buffer tank (11), the CO2 cylinder (12), the CH4 cylinder (13), the CNG station pipeline (14), and the purified gas buffer tank (15) through pipelines respectively. The raw material gas compressor (6) is connected to the raw material gas buffer tank (7) via a pipeline. The raw material gas buffer tank (7) is connected to the gas inlet at the bottom of the adsorption-desorption tower (5) and the vacuum pump (8) via pipelines. The vacuum pump (8) is connected to the gas outlet at the bottom of the adsorption-desorption tower (5) and the desorbed gas storage tank (3) via pipelines. The purified gas outlet at the top of the adsorption-desorption tower (5) is connected to the purified gas storage tank (2) via a pipeline. The purified gas storage tank (2) is connected to the purified gas separator (9). The desorbed gas storage tank (3) is connected to the desorbed gas separator (10) through a pipeline; The purified gas separator (9) is connected to the purified gas and desorbed gas mixing tank (4), the purified gas buffer tank (15), and the desorbed gas separator (10) respectively through pipelines; the desorbed gas separator (10) is connected to the desorbed gas buffer tank (11) through pipelines. The purified gas and desorbed gas mixing tank (4) is connected to the purified gas and desorbed gas mixing compressor (16) through a pipeline. The purified gas and desorbed gas mixing compressor (16) is connected to the purified gas and desorbed gas mixing heat exchanger (17) through a pipeline. The purified gas and desorbed gas mixing heat exchanger (17) is connected to the high-purity gas cylinder (18) and the CNG station pipeline (14) through pipelines respectively.

2. The pilot-scale experimental apparatus for decarbonization of natural gas VTSA without greenhouse gas emissions according to claim 1, characterized in that, The CH4 gas cylinder (13), CO2 gas cylinder (12), purified gas buffer tank (15) and desorption gas buffer tank (11) constitute a raw material gas component adjustment system. The CH4 gas cylinder (13) and purified gas buffer tank (15) are connected, and the CO2 gas cylinder (12) and desorption gas buffer tank (11) are connected.

3. The pilot-scale experimental apparatus for decarbonization of natural gas VTSA without greenhouse gas emissions according to claim 2, characterized in that, The adsorption-desorption tower (5) is equipped with a heat transfer oil heater (22) on its exterior.

4. The pilot-scale experimental apparatus for decarbonization of natural gas VTSA without greenhouse gas emissions according to claim 3, characterized in that, Each pipeline is equipped with a regulating valve (19).

5. A pilot-scale experimental apparatus for decarbonization of natural gas VTSA without greenhouse gas emissions according to claim 4, characterized in that, Pressure measuring instruments (20) and temperature measuring instruments (21) are installed on the raw gas mixing tank (1), the desorbed gas storage tank (3), the purified gas and desorbed gas mixing tank (4), and the adsorption-desorption tower (5).

6. A pilot-scale experimental apparatus for decarbonization of natural gas VTSA without greenhouse gas emissions according to claim 5, characterized in that, Sampling ports are provided on the raw material gas mixing tank (1), the purified gas storage tank (2), the desorbed gas storage tank (3), and the purified gas and desorbed gas mixing tank (4).

7. A pilot-scale experimental apparatus for decarbonization of natural gas VTSA without greenhouse gas emissions according to claim 6, characterized in that, Different proportions of raw material gas were prepared in the raw material gas mixing tank (1) according to different experimental research purposes.

8. A pilot-scale experimental method for natural gas VTSA decarbonization without greenhouse gas emissions, implemented using the pilot-scale experimental apparatus for natural gas VTSA decarbonization without greenhouse gas emissions as described in any one of claims 1-7, characterized in that, Includes the following steps: S1. At the start of the experiment, based on the ratio of CO2 to CH4 in the pipeline natural gas, gas is supplied to the raw material gas mixing tank through CH4 gas cylinder or CO2 gas cylinder, gas is supplied to the purified gas buffer tank through CH4 gas cylinder, and gas is supplied to the desorption gas buffer tank through CO2 gas cylinder, so that the raw material gas ratio meets the experimental requirements. S2. The raw material gas prepared in step S1 is pressurized by a raw material gas compressor to meet the raw material gas inlet pressure requirement of 4.0 ~ 4.5 MPa, and coordinated with the regulating valve at the top of the adsorption-desorption tower to meet the flow rate requirement of 250 ~ 300 m³ / h in the adsorption-desorption tower. 3 The requirements are: / h and pressure of 3.5 ~ 4.0 MPa; S3. When the CH4 content in the purified gas buffer tank is not less than 99%, and the CO2 content in the desorption gas buffer tank is higher than that in the raw gas, shut off the CH4 and CO2 cylinders. Supply high-purity CH4 from the purified gas buffer tank or high-purity CO2 from the desorption gas buffer tank, respectively. Adjust the raw gas ratio to conduct a natural gas decarbonization experiment. The formula for calculating the gas ratio is: ； Where C represents the CO2 content of the raw gas, C P C represents the CO2 content of the pipeline gas. S For purified gas or CH4 cylinders, the CH4 content, C D For desorption gas or CO2 content in CO2 cylinders, F P F represents the gas flow rate in the pipeline. S For the flow rate of purified gas or CH4 cylinders, F D For desorption gas or CO2 cylinder flow rate; S4. When the natural gas decarbonization experiment in step S3 is proceeding stably, the purified gas from the adsorption-desorption tower is depressurized by the regulating valve and enters the purified gas storage tank. Then the purified gas is processed by the purified gas separator to remove impurities from the purified gas and obtain the processed purified gas. S5. When the CH4 content of the purified gas in step S4 is no higher than 50 ppm and the CH4 content is no higher than 3% when the purified gas is used as pipeline gas, close the raw material gas inlet regulating valve and the purified gas outlet regulating valve of the adsorption-desorption tower, open the heat transfer oil heater, and heat the outer wall jacket of the adsorption-desorption tower until the CO2 content of the desorbed gas no longer increases. S6. Based on the desorption gas generated in the adsorption-desorption tower in step S5, the desorption gas in the adsorption-desorption tower is extracted by a vacuum pump and introduced into the desorption gas storage tank. Then, the desorption gas is processed by the desorption gas separator to remove impurities in the desorption gas and obtain the processed desorption gas. S7. The purified gas obtained in step S4 and the desorbed gas obtained in step S6 are introduced into the purified gas and desorbed gas mixing tank. The ratio of the mixed gas is adjusted by controlling the flow rate of the purified gas and the desorbed gas to obtain a mixed gas. The mixed gas is pressurized by the purified gas and desorbed gas mixing gas compressor, and then heated by the purified gas and desorbed gas mixing gas heat exchanger before being introduced into the downstream of the CNG station pipeline.

9. A pilot-scale experimental method for decarbonization of natural gas VTSA without greenhouse gas emissions according to claim 8, characterized in that, Step S7 involves sampling the gas content inside the test purification gas and desorption gas mixing tank through the sampling port to ensure that the CO2 content in the mixed gas is lower than the CO2 content in the CNG station pipeline.

10. A pilot-scale experimental method for decarbonization of natural gas VTSA without greenhouse gas emissions according to claim 9, characterized in that, When the purified gas obtained in step S4 and the desorbed gas obtained in step S6 are not reinjected into the pipeline gas, the following treatments are performed respectively: The treated purified gas is introduced into a purified gas and desorbed gas mixing tank, and then pressurized by a purified gas and desorbed gas mixing compressor before being introduced into a CH4 gas cylinder. The treated desorbed gas is fed into a mixture tank of purified gas and desorbed gas, and then pressurized by a compressor of the mixture of purified gas and desorbed gas before being fed into a CO2 cylinder.

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