Natural gas hydrogen production converted gas purification device adopting six-tower pressure swing adsorption process

Abstract

The utility model provides a natural gas hydrogen production converted gas purification device adopting a six-tower pressure swing adsorption process, which comprises a medium-shift gas unit, a gas-liquid separation buffer tank, an adsorption tower A, an adsorption tower B, an adsorption tower C, an adsorption tower D, an adsorption tower E, an adsorption tower F, a product gas buffer tank, a forward discharge gas buffer tank and a hydrogen user unit, the adsorption tower A, the adsorption tower B, the adsorption tower C, the adsorption tower D, the adsorption tower E and the adsorption tower F are connected in parallel and are respectively provided with a lower pipeline and an upper pipeline, the upper pipeline is provided with a program control valve I, a program control valve II and a program control valve III, the upper pipeline is connected with a product gas pipeline, the product gas pipeline is connected with a product gas buffer tank, and the product gas buffer tank is output to a hydrogen user unit. And the forward deflation buffer tank is respectively connected with pipelines of the program control valve I and the program control valve III. The utility model realizes the purpose of maintenance without stopping production, increases the long-term stable operation reliability, slows down the change amplitude of pressure in the tower, and relieves the scouring of airflow to the adsorbent.

Description

Technical Field

[0001] This utility model relates to the technical field of hydrogen production and purification equipment, specifically to a natural gas hydrogen production and conversion gas purification equipment using a six-tower pressure swing adsorption process. Background Technology

[0002] Currently, the pressure swing adsorption (PSA) process in existing natural gas-to-hydrogen plants employs a 5-1-3 / P (5 adsorption towers, 1 tower adsorbing simultaneously, 2 pressure equalization cycles) atmospheric desorption operation. Each adsorption tower undergoes nine steps in one cycle: adsorption (A), first equalization desorption (E1D), second equalization desorption (E2D), forward release (PP), reverse release (D), flushing (P), second equalization rise (E2R), first equalization rise (E1R), and final charging (FR). If any tower fails during operation, the entire hydrogen production unit must be shut down for maintenance. Restarting causes operational difficulties and resource waste, and the long-term reliability of the unit needs improvement. Therefore, improvements are necessary. Utility Model Content

[0003] The purpose of this invention is to provide a natural gas hydrogen production conversion gas purification device using a six-tower pressure swing adsorption process to solve the above problems, thereby achieving the goal of maintenance without interrupting production and increasing the reliability of long-term stable operation of the device.

[0004] This utility model achieves the above-mentioned objectives through the following technical solution: a natural gas to hydrogen conversion gas purification device using a six-tower pressure swing adsorption process, comprising a medium-pressure gas conversion unit, a gas-liquid separation buffer tank, adsorption towers A, B, C, D, E, and F, a product gas buffer tank, a forward-release gas buffer tank, and a hydrogen user unit. The medium-pressure gas conversion unit outputs gas to the gas-liquid separation buffer tank. Adsorption towers A, B, C, D, E, and F are connected in parallel and are provided with a lower pipeline and an upper pipeline. The lower pipeline is connected to desorption gas pipeline I and desorption gas pipeline II. The upper pipeline is provided with programmable valve I, programmable valve II, and programmable valve III. The upper pipeline is connected to a product gas pipeline, which is connected to the product gas buffer tank. The product gas buffer tank outputs gas to the hydrogen user unit. The forward-release gas buffer tank is connected to the pipelines of programmable valve I and programmable valve III respectively.

[0005] As a preferred embodiment of this invention, the gas-liquid separation buffer tank is provided with a venting main.

[0006] As a preferred embodiment of this invention, a gate valve is provided on the connecting pipeline between the venting buffer tank and the lower pipeline.

[0007] As a preferred embodiment of this utility model, a flushing gas recovery control valve I is provided between the desorption gas pipeline I and the lower pipeline, and a flushing gas recovery control valve II is provided between the desorption gas pipeline II and the lower pipeline.

[0008] As a preferred embodiment of this utility model, a programmable valve IV is provided on the upper pipeline, and an interlocking alarm I and a control relay I are provided on the programmable valve IV.

[0009] As a preferred embodiment of this invention, a nitrogen pipeline is provided on the product gas pipeline, and the nitrogen pipeline is connected to the output pipeline of the intermediate gas conversion unit.

[0010] As a preferred embodiment of this utility model, the product gas pipeline is provided with a circulation pipeline, which is connected to the upper pipeline. A programmable valve V is provided on the circulation pipeline, and an interlocking alarm II and a control relay II are provided on the programmable valve V.

[0011] As a preferred embodiment of this invention, a pressure control valve I is provided on the gas pipeline of the product.

[0012] As a preferred embodiment of this utility model, the programmable valve I, programmable valve II and programmable valve III are equipped with an interlocking alarm III and a control relay III.

[0013] As a preferred embodiment of this utility model, a pressure control valve II is provided on the connecting pipeline between the venting buffer tank and the programmable valve III.

[0014] The beneficial effects of this utility model are as follows: This utility model adopts a six-tower process, namely a pressure swing adsorption process with one tower adsorbing, three equalization pressures, and atmospheric pressure desorption. Each adsorption tower needs to go through eleven steps in one cycle: adsorption (A), first equalization pressure drop (E1D), second equalization pressure drop (E2D), forward release (PP), third equalization pressure drop (E3D), reverse release (D), rinsing (P), third equalization pressure rise (E3R), second equalization pressure rise (E2R), first equalization pressure rise (E1R), and final charging (FR). The six adsorption towers are staggered in their execution procedures to form a closed loop, ensuring continuous raw material input and continuous product output. The process flow mainly adopts the 6-2-2 / P operation mode. When the programmable valve element connected to a certain adsorption tower fails, it can be automatically or manually switched to the 5-1-2 / P operation mode according to the requirements of the product gas, and then the faulty tower is disconnected, achieving the purpose of maintenance without stopping production. This greatly increases the reliability of the long-term stable operation of the equipment. The pressure equalization process reduces the pressure fluctuation within the adsorption tower, alleviates the scouring of the adsorbent by the airflow, extends the adsorbent's service life, improves the yield, and also extends the equipment's lifespan. Furthermore, the use of atmospheric pressure desorption facilitates the complete recovery of desorbed gas for combustion, while also ensuring the desorption effect of the adsorbent and the purity of the hydrogen. Attached Figure Description

[0015] Figure 1 This is a schematic diagram illustrating the principle of this utility model;

[0016] In the diagram: 1. Medium-duty gas conversion unit; 2. Gas-liquid separation buffer tank; 3. Adsorption tower A; 4. Adsorption tower B; 5. Adsorption tower C; 6. Adsorption tower D; 7. Adsorption tower E; 8. Adsorption tower F; 9. Product gas buffer tank; 10. Forward venting buffer tank; 11. Hydrogen user unit; 12. Lower pipeline; 13. Upper pipeline; 14. Desorption gas pipeline I; 15. Desorption gas pipeline II; 16. Programmable control valve I; 17. Programmable control valve II; 18. Programmable control valve III; 19. Product gas pipeline; 20. Vent main; 21. 21. Gate valve; 22. Flushing gas recovery programmable valve I; 23. Flushing gas recovery programmable valve II; 24. Programmable valve IV; 25. Interlock alarm I; 26. Control relay I; 27. Nitrogen pipeline; 28. Circulation pipeline; 29. ​​Programmable valve V; 30. Interlock alarm II; 31. Control relay II; 32. Pressure control valve I; 33. Interlock alarm III; 34. Control relay III; 35. Pressure control valve II. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0018] Please see Figure 1 As shown, a natural gas-to-hydrogen conversion gas purification device employing a six-tower pressure swing adsorption (PSA) process includes a medium-pressure gas conversion unit 1, a gas-liquid separation buffer tank 2, adsorption towers A3, B4, C5, D6, E7, and F8, a product gas buffer tank 9, a forward-release gas buffer tank 10, and a hydrogen user unit 11. The gas output from the medium-pressure gas conversion unit 1 is fed into the gas-liquid separation buffer tank 2. The adsorption towers A3, B4, C5, D6, E7, and F8... 8 are connected in parallel and are provided with a lower pipeline 12 and an upper pipeline 13. The lower pipeline 12 is connected to a desorption gas pipeline I14 and a desorption gas pipeline II15. The upper pipeline 13 is provided with a programmable control valve I16, a programmable control valve II17 and a programmable control valve III18. The upper pipeline 13 is connected to a product gas pipeline 19. The product gas pipeline 19 is connected to a product gas buffer tank 9. The product gas buffer tank 9 outputs to the hydrogen user unit 11. The outflow gas buffer tank 10 is connected to the pipelines of programmable control valve I16 and programmable control valve III18 respectively.

[0019] In this embodiment, the present invention employs a six-tower process, namely a pressure swing adsorption process involving three equalizations in one tower and desorption at atmospheric pressure. Each adsorption tower undergoes eleven steps in one cycle: adsorption (A), first equalization desorption (E1D), second equalization desorption (E2D), forward release (PP), third equalization desorption (E3D), reverse release (D), rinsing (P), third equalization rise (E3R), second equalization rise (E2R), first equalization rise (E1R), and final charging (FR). The six adsorption towers are staggered in their execution procedures, forming a closed-loop cycle to ensure continuous raw material input and continuous product output. After adsorption, programmable valves I16, II17, and III18 are used to control the equalization rate decrease or equalization rate increase, respectively. The process flow mainly adopts the 6-2-2 / P operation mode. When a programmable valve component connected to a certain adsorption tower fails, it can be automatically or manually switched to the 5-1-2 / P operation mode according to the requirements of the product gas, and then the faulty tower is shut down, achieving the purpose of maintenance without interrupting production. This greatly increases the reliability of the long-term stable operation of the unit. The three-stage pressure equalization process reduces the pressure change amplitude in the adsorption tower, alleviates the scouring of the adsorbent by the airflow, extends the service life of the adsorbent, improves the yield, and also improves the life of the equipment. Moreover, the use of atmospheric pressure desorption method is conducive to the complete recovery of desorbed gas for combustion, while also ensuring the desorption effect of the adsorbent and the purity of hydrogen.

[0020] Specifically, the medium-density gas (MDG) is first fed into the gas-liquid separation buffer tank 2 from the medium-density gas unit 1. This fully utilizes the heat of the MDD, saving heating steam and reducing the consumption of circulating water required for cooling the MDD. The mixture is then separated into gas and liquid, and hydrogen of the desired purity is obtained at the outlet. The gas-liquid separation buffer tank 2 has functions of pressure buffering, temperature regulation, and safety monitoring. The gas then enters adsorption towers 3A, B4, C5, D6, E7, and F8. These six adsorption towers alternately perform adsorption, desorption, and adsorption preparation processes to achieve continuous hydrogen production. Impurities other than hydrogen are sequentially adsorbed by the adsorbents packed in the adsorption towers, yielding product hydrogen with a purity greater than 99.9%. The hydrogen gas is then buffered and output to the hydrogen user unit 11 via product gas pipeline 19 to product gas buffer tank 9. The forward-release gas buffer tank 10 is used for gas buffering, hydrogen recovery, and pressure stabilization. After the adsorption process, the forward-release gas buffer tank 10 collects the higher-pressure hydrogen released from the adsorption tower in the direction of adsorption. This process is not only a depressurization process but also a process of recovering hydrogen from the dead space in the bed. Furthermore, the hydrogen in the forward-release gas buffer tank 10 can be further utilized, effectively saving resources and improving the overall energy efficiency of the process. During different stages of the adsorption tower, such as reverse release and rinsing, the forward-release gas buffer tank 10 helps stabilize the pressure within the system, ensuring the smooth and continuous operation of the entire PSA process. Desorption gas pipelines I14 and II15 are used for desorption gas recovery.

[0021] As a technical optimization of this utility model, the gas-liquid separation buffer tank 2 is provided with a venting main pipe 20 at the output.

[0022] In this embodiment, the vent manifold 20 can expel air to ensure the normal operation of the system.

[0023] As a technical optimization of this utility model, a gate valve 21 is installed on the connecting pipeline between the venting buffer tank 10 and the lower pipeline 12.

[0024] In this embodiment, the gate valve 21 has the functions of shut-off, regulation and anti-reverse flow.

[0025] As a technical optimization of this utility model, a flushing gas recovery programmable valve I22 is provided between the desorption gas pipeline I14 and the lower pipeline 12, and a flushing gas recovery programmable valve II23 is provided between the desorption gas pipeline II15 and the lower pipeline 12.

[0026] In this embodiment, flushing gas recovery control valve I22 and flushing gas recovery control valve II23 are capable of controlling flushing gas recovery.

[0027] As a technical optimization of this utility model, a programmable valve IV24 is installed on the upper pipeline 13, and an interlocking alarm I25 and a control relay I26 are installed on the programmable valve IV24.

[0028] In this embodiment, the interlocking alarm I25 plays an important role in theft prevention and fire prevention, and can effectively protect the safety of people and property. The control relay I26 is used to control disconnection or connection.

[0029] As a technical optimization of this utility model, a nitrogen pipeline 27 is provided on the product gas pipeline 19, and the nitrogen pipeline 27 is connected to the output pipeline of the intermediate gas conversion unit 1.

[0030] In this embodiment, the nitrogen pipeline 27 delivers high-purity nitrogen, which can dilute and purify the product gas, removing oxygen and other impurities that may interfere with the reaction.

[0031] As a technical optimization of this utility model, the product gas pipeline 19 is provided with a circulation pipeline 28, which is connected to the upper pipeline 13. A programmable control valve V29 is provided on the circulation pipeline 28, and an interlock alarm II30 and a control relay II31 are provided on the programmable control valve V29.

[0032] In this embodiment, the valves of the circulation pipeline 28 can be remotely controlled to open and close. The interlocking alarm II30 plays an important role in theft prevention and fire prevention, and can effectively protect the safety of people and property. The control relay II31 is used to control the disconnection or connection.

[0033] As a technical optimization of this utility model, a pressure control valve I32 is provided on the product gas pipeline 19.

[0034] In this embodiment, the pressure control valve I32 can effectively control the pressure and is used in conjunction with other valves.

[0035] As a technical optimization of this utility model, the programmable valves I16, II17 and III18 are equipped with interlocking alarm III33 and control relay III34.

[0036] In this embodiment, the interlocking alarm III33 plays an important role in theft prevention and fire prevention, and can effectively protect the safety of people and property. The control relay II34I is used to control disconnection or connection.

[0037] As a technical optimization of this utility model, a pressure control valve II35 is provided on the connecting pipeline between the outgassing buffer tank 10 and the programmable valve III18.

[0038] In this embodiment, the pressure control valve II35 can effectively control the pressure and is used in conjunction with other valves.

[0039] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0040] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A natural gas to hydrogen reforming gas purification plant employing a six-column pressure swing adsorption process, characterized by: It includes the middle variable gas unit (1), the gas-liquid separation buffer tank (2), the adsorption tower A (3), the adsorption tower B (4), the adsorption tower C (5), the adsorption tower D (6), the adsorption tower E (7), the adsorption tower F (8), the product gas buffer tank (9), the order release gas buffer tank (10) and the hydrogen user unit (11), the middle variable gas unit (1) is exported to the gas-liquid separation buffer tank (2) inside, the adsorption tower A (3), the adsorption tower B (4), the adsorption tower C (5), the adsorption tower D (6), the adsorption tower E (7) and the adsorption tower F (8) are parallel and are provided with lower pipeline (12) and upper pipeline (13), the lower pipeline (12) is connected and is provided with desorption gas pipeline I (14) and desorption gas pipeline II (15), the upper pipeline (13) is provided with program-controlled valve I (16), program-controlled valve II (17) and program-controlled valve III (18), the upper pipeline (13) is connected and is provided with product gas pipeline (19), the product gas pipeline (19) is connected product gas buffer tank (9), the product gas buffer tank (9) is exported to hydrogen user unit (11), the order release gas buffer tank (10) is connected the pipeline of program-controlled valve I (16) and program-controlled valve III (18) respectively.

2. The apparatus for purifying the converted gas of hydrogen produced from natural gas by adopting a six-tower pressure swing adsorption process according to claim 1, characterized in that: The gas-liquid separation buffer tank (2) is exported and is provided with venting main pipe (20).

3. The apparatus for purifying reformed gas produced from natural gas according to the process of pressure swing adsorption with six towers according to claim 1, characterized in that: The connecting pipeline between the order release gas buffer tank (10) and lower pipeline (12) is provided with gate valve (21).

4. The apparatus for purifying reformed gas produced from natural gas to produce hydrogen by a six-tower pressure swing adsorption process according to claim 1, characterized in that: The desorption gas pipeline I (14) and lower pipeline (12) are provided with flushing gas recovery program-controlled valve I (22) between, the desorption gas pipeline II (15) and lower pipeline (12) are provided with flushing gas recovery program-controlled valve II (23) between.

5. The apparatus for purifying reformed gas produced from natural gas to produce hydrogen by a six-tower pressure swing adsorption process according to claim 1, characterized in that: The upper pipeline (13) is provided with program-controlled valve IV (24), the program-controlled valve IV (24) is provided with interlocking alarm I (25) and control relay I (26) on.

6. The apparatus for purifying reformed gas produced from natural gas to produce hydrogen by a six-tower pressure swing adsorption process according to claim 1, characterized in that: The product gas pipeline (19) is provided with nitrogen pipeline (27), and the nitrogen pipeline (27) is connected with the output pipeline of the middle variable gas unit (1).

7. The apparatus for purifying reformed gas produced from natural gas to produce hydrogen by a six-tower pressure swing adsorption process according to claim 1, characterized in that: The product gas pipeline (19) is provided with circulation pipeline (28), and the circulation pipeline (28) is communicated with the upper pipeline (13) respectively, the circulation pipeline (28) is provided with program-controlled valve V (29), and the program-controlled valve V (29) is provided with interlocking alarm II (30) and control relay II (31).

8. The apparatus for purifying reformed gas produced from natural gas to produce hydrogen by a six-tower pressure swing adsorption process according to claim 1, characterized in that: The product gas pipeline (19) is provided with pressure control valve I (32).

9. The apparatus for purifying reformed gas produced from natural gas according to the process of pressure swing adsorption with six towers according to claim 1, characterized in that: The program-controlled valve I (16), program-controlled valve II (17) and program-controlled valve III (18) are provided with interlocking alarm III (33) and control relay III (34) on.

10. The apparatus for purifying reformed gas produced from natural gas to produce hydrogen by a six-column pressure swing adsorption process according to claim 1, characterized in that: The connecting pipeline of the order release gas buffer tank (10) and program-controlled valve III (18) is provided with pressure control valve II (35).

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