Dry adsorption vent gas recovery device for extracting high-purity helium from BOG (Boil Off Gas)

Abstract

The utility model belongs to the technical field of waste gas recovery, and particularly relates to a BOG (Boil Off Gas) extraction high-purity helium drying adsorption vent gas recovery device which comprises a drying adsorber, an outlet of the drying adsorber is provided with a vent gas pipeline, the other end of the vent gas pipeline is connected with a buffer tank, an outlet of the buffer tank is connected with a first compressor, and the first compressor is connected with a second compressor. An outlet of the first compressor is connected with a membrane separation device, and an outlet of the membrane separation device is connected with a tail gas emission pipeline and a permeation gas pipeline. By arranging the first membrane separation tank and the second membrane separation tank, the first membrane separation tank and the second membrane separation tank can be connected in series or in parallel, and permeation gas obtained during series connection serves as industrial helium gas to be filled into the packaging grids, so that more helium gas in vent gas is recycled, the waste of helium gas is reduced, and the production cost is reduced. The permeated gas obtained in parallel connection enters a BOG helium extraction process for cyclic helium extraction, and the first separation tank and the second separation tank are used for separating the discharged gas at the same time, so that the separation efficiency is improved.

Description

Technical Field

[0001] This utility model belongs to the field of waste gas recovery technology, specifically relating to a BOG extraction, high-purity helium drying, adsorption, and air recovery device. Background Technology

[0002] Helium is a rare gas, abundant in the universe but scarce on Earth, primarily found in the atmosphere, rocks, and natural gas. Under normal conditions, helium is colorless and odorless, and is the only substance that cannot solidify under standard atmospheric pressure. Its unique physical properties determine its specific uses. As a scarce strategic resource for national defense and high-tech industry development, helium is widely used in military, scientific research, petrochemical, refrigeration, medical, semiconductor, pipeline leak detection, superconducting experiments, metal manufacturing, deep-sea diving, high-precision welding, and optoelectronic product manufacturing, making it of great significance to scientific research.

[0003] A system and method for extracting high-purity helium from liquefied natural gas (BOG) flash vapor, with announcement number CN114674115B, is disclosed. This system employs a process of cryogenic distillation, cyclic oxygenation and hydrogen removal, cryogenic crude extraction, and cryogenic adsorption purification to extract high-purity helium from BOG flash vapor. In the cyclic oxygenation and hydrogen removal process, the dehydrogenated crude helium gas enters a dryer for drying. The dryer includes two adsorbers: Adsorber 1 and Adsorber 2. Both Adsorbers 1 and Adsorber 2 contain molecular sieves, alumina, and activated carbon. Alumina is used to adsorb water, molecular sieves are used to adsorb CO2, and activated carbon is used to adsorb nitrogen. Adsorbers 1 and Adsorber 2 are used alternately. When Adsorber 1 is adsorbing, Adsorber 2 is regenerated for backup. When Adsorber 1 becomes saturated, the system switches to Adsorber 2 for adsorption, and then Adsorber 1 is regenerated, and this cycle is repeated.

[0004] When regenerating the adsorber, the gas inside the adsorber must first be discharged to depressurize it. In the existing technology, the vent air of the adsorber is directly vented. However, the vent air has a relatively high helium content. If it is vented directly, helium will be wasted. Moreover, the CO2 and water content in this vent air is relatively high, so it cannot be returned to the BOG feed gas to continue participating in the helium extraction process. Utility Model Content

[0005] The purpose of this invention is to provide a device for BOG extraction of high-purity helium, drying, adsorption, and air recovery, in order to solve the problems mentioned in the background art.

[0006] To achieve the above-mentioned technical objectives, the technical solution of this utility model is as follows:

[0007] A device for BOG extraction of high-purity helium through drying, adsorption, and air recovery includes a drying adsorber, an air release pipeline at the outlet of the drying adsorber, an air release pipeline at the other end of the air release pipeline, a first compressor at the outlet of the air release pipeline, a membrane separation device at the outlet of the first compressor, and a tail gas emission pipeline and a permeate pipeline at the outlet of the membrane separation device.

[0008] As a further improvement, the membrane separation device includes a first membrane separation tank and a second membrane separation tank. Both the first membrane separation tank and the second membrane separation tank are provided with an inlet, an exhaust gas outlet, and a permeate gas outlet. The inlet of the first membrane separation tank is connected to the outlet of the first compressor through a first inlet pipe. The exhaust gas outlet of the first membrane separation tank is connected to the inlet of the second membrane separation tank through a series pipe. The exhaust gas outlet of the second membrane separation tank is connected to the exhaust gas emission pipe. The permeate gas outlets of both the first membrane separation tank and the second membrane separation tank are connected to the permeate gas pipe through an outlet pipe.

[0009] As a further improvement, the outlet of the permeate gas pipeline is connected to a buffer tank, the outlet of the buffer tank is connected to a second compressor, and the outlet of the second compressor is provided with a container filling port.

[0010] As a further improvement, a second intake pipe is also connected to the first intake pipe, the outlet of the second intake pipe is connected to the inlet of the second membrane separator, and a parallel exhaust pipe is also connected to one end of the series pipe near the exhaust outlet of the first membrane separator, and the other end of the parallel exhaust pipe is connected to the exhaust emission pipe.

[0011] As a further improvement, a shut-off valve one is provided at the end of the series pipeline near the second membrane separator, a shut-off valve two is provided on the exhaust gas parallel pipeline, a shut-off valve three is provided on the second air inlet pipeline, and a shut-off valve four is provided at the inlet of the buffer tank.

[0012] As a further improvement, a return pipeline is also connected to the permeate gas pipeline, and a carbon dioxide detection device is also connected to the permeate gas pipeline.

[0013] As a further improvement, the membrane separation device uses a carbon molecular sieve hollow fiber membrane.

[0014] Due to the adoption of the above technical solution, the beneficial effects of this utility model are as follows:

[0015] The BOG extraction high-purity helium drying adsorption vent gas recovery device provided by this utility model closes shut-off valves three, two, and five, and opens shut-off valves one, four, and six. The first membrane separation tank and the second membrane separation tank are connected in series. The tail gas obtained from the first membrane separation tank continues to enter the second membrane separation tank for secondary separation. The permeate obtained from the first and second membrane separation tanks is mixed and then used to fill the container to obtain industrial helium. By connecting the first and second membrane separation tanks in series, more helium in the vent gas is recovered, reducing helium waste.

[0016] When container filling is not required, open shut-off valves three, two, and five, and close shut-off valves one, four, and six. The first membrane separator and the second membrane separator are in parallel. The first membrane separator and the second membrane separator simultaneously separate the vented air. The resulting permeate gas is mixed and returned to the BOG helium extraction system. The simultaneous separation of vented air by the first membrane separator and the second membrane separator improves the separation efficiency. Attached Figure Description

[0017] Figure 1 This is a flowchart of the equipment of this utility model;

[0018] Wherein: 1-Drying adsorber, 2-Air venting pipeline, 3-Airbag, 4-First compressor, 5-First membrane separator, 6-Second membrane separator, 7-First air inlet pipeline, 8-Second air inlet pipeline, 9-Series pipeline, 10-Tail gas emission pipeline, 11-Output pipeline, 12-Permeate gas pipeline, 13-Buffer tank, 14-Second compressor, 15-Container compartment, 16-Tail gas parallel pipeline, 17-Return pipeline. Detailed Implementation

[0019] The present invention will be further described below with reference to specific embodiments and accompanying drawings. The accompanying drawings are for illustrative purposes only, representing schematic diagrams only, not actual physical objects, and should not be construed as limiting the scope of this application. To better illustrate the embodiments of the present invention, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0020] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," and "right" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this application. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0021] like Figure 1 As shown, a BOG extraction high-purity helium drying adsorption venting recovery device includes a drying adsorber 1, an venting pipe 2 at the outlet of the drying adsorber 1, an air bag 3 at the other end of the venting pipe 2, a first compressor 4 at the outlet of the air bag 3, a membrane separation device at the outlet of the first compressor 4, and a tail gas emission pipe 10 and a permeate pipe 12 at the outlet of the membrane separation device.

[0022] When the dryer adsorber 1 needs to be regenerated, the vented air in the dryer adsorber 1 enters the air bag 3 through the vented air pipe 2. Then, the vented air in the air bag 3 is pressurized by the first compressor 4 and enters the membrane separation device. The membrane separation device uses a carbon molecular sieve hollow fiber membrane. The membrane separation device uses the different rates of helium, nitrogen and carbon dioxide passing through the fiber membrane to separate the helium in the vented air from other gases. The helium passing through the membrane separation device enters the permeate pipe 12, while the other gases enter the tail gas emission pipe 10 for emission.

[0023] In this embodiment, the membrane separation device includes a first membrane separation tank 5 and a second membrane separation tank 6. Both the first membrane separation tank 5 and the second membrane separation tank 6 are provided with an inlet, an exhaust gas outlet, and a permeate gas outlet. The inlet of the first membrane separation tank 5 is connected to the outlet of the first compressor 4 through a first air inlet pipe 7. The exhaust gas outlet of the first membrane separation tank 5 is connected to the inlet of the second membrane separation tank 6 through a series pipe 9. The exhaust gas outlet of the second membrane separation tank 6 is connected to the exhaust gas discharge pipe 10. The permeate gas outlets of both the first membrane separation tank 5 and the second membrane separation tank 6 are connected to the permeate gas pipe 12 through an output pipe 11.

[0024] The outlet of the permeate pipe 12 is connected to a buffer tank 13, the outlet of the buffer tank 13 is connected to a second compressor 14, and the outlet of the second compressor 14 is provided with a filling port for a container 15.

[0025] The vent gas output from the outlet of the first compressor 4 enters the first membrane separator 5 through the first inlet pipe 7. After separation in the first membrane separator 5, the resulting permeate gas enters the output pipe 11 through the permeate gas outlet of the first membrane separator 5. The tail gas obtained from the tail gas outlet of the first membrane separator 5 enters the second membrane separator 6 through the series pipe 9. Secondary separation is performed in the second membrane separator 6. The permeate gas obtained from the permeate gas outlet of the second membrane separator 6 and the permeate gas obtained from the first membrane separator 5 enter the permeate gas pipe 12 together. The gas in the permeate gas pipe 12 enters the buffer tank 13, and then is compressed by the second compressor 14 and filled into the container 15 through the filling port of the container 15 to obtain industrial helium.

[0026] In this embodiment, a second intake pipe 8 is also connected to the first intake pipe 7. The outlet of the second intake pipe 8 is connected to the inlet of the second membrane separator 6. A parallel exhaust pipe 16 is also connected to one end of the series pipe 9 near the exhaust outlet of the first membrane separator 5. The other end of the parallel exhaust pipe 16 is connected to the exhaust exhaust pipe 10.

[0027] A shut-off valve is provided at one end of the series pipeline 9 near the second membrane separator 6, a shut-off valve is provided on the exhaust gas parallel pipeline 16, a shut-off valve is provided on the second air inlet pipeline 8, and a shut-off valve is provided at the inlet of the buffer tank 13.

[0028] The permeate gas pipeline is also connected to a return pipeline 17. The permeate gas pipeline 12 is also equipped with a carbon dioxide detection device, and the return pipeline 17 is equipped with a shut-off valve.

[0029] The outlet of buffer tank 13 is equipped with a shut-off valve 6.

[0030] In this embodiment, the membrane separation device uses a carbon molecular sieve hollow fiber membrane.

[0031] In this embodiment, when it is necessary to fill the container 15 with industrial helium, shut-off valves three, two, and five are all closed, while shut-off valves one, four, and six are all open. The vented air in the dryer adsorber 1 enters the air bag 3, and then, after being pressurized by the first compressor 4, enters the first membrane separator 5 through the first inlet pipe. After separation in the first membrane separator 5, the resulting permeate enters the output pipe 11 through the permeate outlet of the first membrane separator 5, and the tail gas exits from the tail gas outlet of the first membrane separator 5. The gas enters the series pipe 9 through the inlet, and then enters the second membrane separator 6 through the inlet. After separation in the second membrane separator 6, the obtained permeate gas enters the output pipe 11 through the permeate gas outlet of the first membrane separator 5 and mixes with the permeate gas obtained in the first membrane separator 5. The tail gas obtained in the second membrane separator 6 enters the tail gas discharge pipe 10 for discharge. The permeate gas mixed in the output pipe 11 enters the buffer tank 13 through the permeate gas pipe 12, and then is compressed by the second compressor 14 and filled into the container 15.

[0032] When filling container 15 is no longer required, shut-off valve six is ​​closed, and helium recovery of the vented air continues. The resulting permeate gas enters buffer tank 13, and the carbon dioxide content in the permeate gas is detected by a carbon dioxide detection device on permeate gas pipeline 12. When the detected carbon dioxide content is less than 1 ppm, shut-off valves one and four are closed, and shut-off valves two, three, and five are opened. The vented air, pressurized by the first compressor 4, enters the first membrane separator 5 and the second membrane separator 6 through the first and second inlet pipelines, respectively. After separation in the first membrane separator 5 and the second membrane separator 6, the permeate gas obtained from the first membrane separator 5 enters the output pipe 11, and the permeate gas obtained from the second membrane separator 6 enters the output pipe 11 and mixes with the permeate gas obtained from the first membrane separator 5. Then, it is transported to the BOG helium extraction process through the permeate gas pipe 12 and the return pipe 17. After mixing with the BOG gas, it enters the helium extraction process again. The tail gas obtained from the first membrane separator 5 enters the tail gas emission pipe 10 through the tail gas parallel pipe 16, and the tail gas in the second membrane separator 6 also enters the tail gas emission pipe 10.

[0033] By setting up a first membrane separation tank and a second membrane separation tank, which can be connected in series or in parallel, the permeate gas obtained when connected in series is used as an industrial helium filling container, allowing more helium in the vented air to be recovered and reducing helium waste. When connected in parallel, the permeate gas obtained enters the BOG helium extraction process for helium extraction. The first and second separation tanks simultaneously separate the vented air, improving separation efficiency.

[0034] The specific embodiments of the present invention described above do not limit the scope of protection of the present invention. Any other corresponding changes and modifications made based on the technical concept of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A device for extracting high-purity helium from BOG, drying, adsorption, and air recovery, characterized in that, The device includes a dryer adsorber, the outlet of which is provided with an air venting pipe, the other end of which is connected to an air bag, the outlet of which is connected to a first compressor, the outlet of which is connected to a membrane separation device, and the outlet of which is connected to an exhaust gas discharge pipe and a permeate gas pipe.

2. The BOG extraction high-purity helium drying adsorption air recovery device according to claim 1, characterized in that, The membrane separation device includes a first membrane separation tank and a second membrane separation tank. Both the first membrane separation tank and the second membrane separation tank are provided with an inlet, an exhaust gas outlet, and a permeate gas outlet. The inlet of the first membrane separation tank is connected to the outlet of the first compressor through a first air inlet pipe. The exhaust gas outlet of the first membrane separation tank is connected to the inlet of the second membrane separation tank through a series pipe. The exhaust gas outlet of the second membrane separation tank is connected to the exhaust gas emission pipe. The permeate gas outlets of both the first membrane separation tank and the second membrane separation tank are connected to the permeate gas pipe through an output pipe.

3. The BOG extraction high-purity helium drying adsorption air recovery device according to claim 2, characterized in that, The outlet of the permeate gas pipeline is connected to a buffer tank, and the outlet of the buffer tank is connected to a second compressor. The outlet of the second compressor is provided with a container filling port.

4. The BOG extraction high-purity helium drying adsorption air recovery device according to claim 3, characterized in that, The first intake pipe is also connected to a second intake pipe, the outlet of which is connected to the inlet of the second membrane separator. The end of the series pipe near the exhaust outlet of the first membrane separator is also connected to a parallel exhaust pipe, the other end of which is connected to the exhaust discharge pipe.

5. The BOG extraction high-purity helium drying adsorption air recovery device according to claim 4, characterized in that, The series pipeline is equipped with a shut-off valve one at one end near the second membrane separator, the exhaust gas parallel pipeline is equipped with a shut-off valve two, the second air inlet pipeline is equipped with a shut-off valve three, and the inlet of the buffer tank is equipped with a shut-off valve four.

6. The BOG extraction high-purity helium drying adsorption air recovery device according to claim 4, characterized in that, The permeate gas pipeline is also connected to a return pipeline, and a carbon dioxide detection device is also connected to the permeate gas pipeline.

7. The BOG extraction high-purity helium drying adsorption air recovery device according to any one of claims 1-6, characterized in that, The membrane separation device uses a carbon molecular sieve hollow fiber membrane.

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