Device and method for removing water from hexafluorobutadiene liquid phase and regenerating adsorbent

Abstract

The invention particularly relates to a device and a method for removing water from a hexafluorobutadiene liquid phase and regenerating an adsorbent. The device comprises a hexafluorobutadiene gas phase feeding pipeline, a nitrogen preheater, a dryer A, a dryer B, a precooler and a condensate recovery tank, wherein the dryer A and the dryer B are arranged in parallel; according to the hexafluorobutadiene liquid-phase water removal method, the hexafluorobutadiene liquid-phase water removal device and the hexafluorobutadiene liquid-phase water removal method are realized through pre-adsorption, low-temperature adsorption, condensate recovery, preheating and purging, high-temperature regeneration and cooling for later use, and the problem of too low adsorption capacity of an adsorption material caused by relatively high temperature of a conventional gas-phase adsorption method can be effectively avoided; the adsorption period and the adsorption depth of the adsorbent are greatly improved, meanwhile, the problems of carbon deposition, polymerization and the like easily occurring during regeneration of hexafluorobutadiene can be effectively prevented, and the service life of the adsorption material is prolonged.

Description

Technical Field

[0001] The present application belongs to the field of fine chemical technology, and specifically relates to a device and method for liquid-phase water removal and adsorbent regeneration of hexafluorobutadiene. Background Art

[0002] Hexafluorobutadiene (C4F6) is a new type of fluorine-containing electronic gas that can be used in a variety of fields, including as an etching gas, polymerization monomer, and synthetic intermediate. During the production process of hexafluorobutadiene (C4F6), water washing and alkaline washing are usually used to remove acidic impurities or other impurities easily absorbed by water from the gas. After washing, the hexafluorobutadiene will carry a large amount of water vapor, which requires deep water removal. If hexafluorobutadiene is used as an etching gas to participate in the preparation of semiconductor devices, the water content of the hexafluorobutadiene needs to be reduced to an extremely low level. The lower the water content of the hexafluorobutadiene, the better the etching effect.

[0003] Traditional water removal methods typically use adsorbents such as silica gel and molecular sieves for vapor-phase adsorption. However, these adsorbents can catalyze hexafluorobutadiene, releasing significant heat and causing carbonization or isomerization and rearrangement reactions, which can reduce its purity. Furthermore, due to hexafluorobutadiene's low boiling point, the adsorbent must be operated at a high temperature to maintain vapor stability during vapor-phase adsorption, which compromises water removal effectiveness.

[0004] Other researchers have attempted to remove water from hexafluorobutadiene using an extraction method. For example, Chinese patent publication CN111138240B discloses a hexafluorobutadiene dehydration device and dehydration method, comprising the following steps: step 1, feeding the hexafluorobutadiene to be dehydrated from a first inlet at the bottom of an extractive distillation tower; step 2, feeding an extractant from a second inlet at the middle of the extractive distillation tower; step 3, allowing the hexafluorobutadiene after extractive distillation to escape from a first outlet at the top of the extractive distillation tower and be collected; step 4, allowing water and the extractant to enter a recovery tower as heavy components. After separation in the recovery tower, the extractant is recycled. The device and method of the present invention are simple, can achieve extractive dehydration of hexafluorobutadiene under relatively low temperature and pressure conditions, and have excellent practicality and process safety. However, the water content of the hexafluorobutadiene prepared based on this method can be reduced to as low as 10 ppm.

[0005] The application document with publication number CN116283485A discloses a method for dehydrating hexafluorobutadiene. The dehydration system includes: a first storage tank, a stirring kettle, a vaporizer, an acid removal tower, and a second storage tank, which are connected in sequence. By using equipment such as a stirring kettle and a vaporizer in the hexafluorobutadiene dehydration system, combined with the acid removal tower treatment, the moisture content of the hexafluorobutadiene is reduced. However, for hexafluorobutadiene used as an etching gas, the lower the moisture content, the better the etching effect. The technical solution of this application can reduce the moisture content of hexafluorobutadiene to 2ppm at most.

[0006] In addition, after hexafluorobutadiene is adsorbed, during regeneration, a small amount of hexafluorobutadiene will be adsorbed in the adsorbent, which is prone to polymerization or carbonization during high-temperature regeneration, clogging the adsorption material and reducing the life of the adsorbent.

[0007] In summary, the existing technology for purifying hexafluorobutadiene has the following problems: ① Traditional adsorption materials have a catalytic effect on hexafluorobutadiene, releasing a large amount of heat and causing hexafluorobutadiene to undergo carbonization or isomerization rearrangement reaction, resulting in reduced hexafluorobutadiene purity; ② After hexafluorobutadiene is adsorbed by traditional methods, during regeneration, a small amount of hexafluorobutadiene is adsorbed in the adsorbent, which is prone to polymerization or carbonization during high-temperature regeneration, clogging the adsorption material and reducing the adsorbent life; ③ The water content of hexafluorobutadiene is still difficult to achieve the ideal effect.

[0008] Therefore, it is urgent to propose a device and method for liquid-phase water removal and adsorbent regeneration of hexafluorobutadiene to solve the problems existing in the prior art. Summary of the Invention

[0009] In response to the problems in the prior art such as high water content in hexafluorobutadiene and deterioration of adsorption effect of adsorbents due to long-term use, this application proposes a device and method for liquid-phase water removal of hexafluorobutadiene and regeneration of adsorbents. The technical solution of this application is as follows:

[0010] On the one hand, the present application provides a device for liquid-phase dehydration of hexafluorobutadiene and adsorbent regeneration, the device comprising a hexafluorobutadiene gas-phase feed pipeline, a nitrogen preheater, a dryer A and a dryer B arranged in parallel, a precooler, and a condensate recovery tank;

[0011] The bottom of the dryer A and the dryer B are connected to the hexafluorobutadiene gas phase feed pipeline through the gas phase feed valve, connected to the precooler liquid outlet through the liquid phase feed valve, and connected to the condensate recovery tank through the condensate recovery valve;

[0012] The tops of the dryers A and B are connected to the nitrogen preheater outlets via nitrogen inlet valves, and are connected to the liquid phase discharge pipelines via liquid phase discharge valves.

[0013] Preferably, the dryers A and B are further connected to an exhaust gas venting pipeline below, and a nitrogen venting valve is provided on the exhaust gas venting pipeline.

[0014] Preferably, the upper portion of the condensate recovery tank is also connected to a vacuum pipeline, and a vacuum valve is provided on the vacuum pipeline.

[0015] Preferably, the dryer A and the dryer B adopt a symmetrical pipeline layout, and the gas phase feed valve, liquid phase feed valve, condensate recovery valve, nitrogen inlet valve, and liquid phase discharge valve are independently controlled.

[0016] Preferably, both the dryer A and the dryer B are provided with an external jacket and an internal heating device.

[0017] On the other hand, the present application provides a method for liquid phase dehydration and regeneration of hexafluorobutadiene, comprising the following steps:

[0018] Step S1. Pre-adsorption: Hexafluorobutadiene gas is directly introduced into dryer A and / or dryer B after regeneration and cooling for adsorption;

[0019] Step S2. Low-temperature adsorption: liquefying the hexafluorobutadiene gas in a precooler and then passing it into dryer A and / or dryer B for liquid-phase adsorption;

[0020] Step S3. Condensate Recovery: After the liquid adsorption is completed, the liquid phase material in dryer A and / or dryer B is transferred to a condensate recovery tank. The condensate recovery tank is controlled at a temperature of -60 to -10°C and a pressure of -0.05 to -0.02 MPa. Recovery is completed 1 to 2 hours after the pressure of dryer A and / or dryer B is equalized with the condensate recovery tank.

[0021] Step S4. Preheating and purging: After the recovery is completed, open the nitrogen preheater to preheat nitrogen and purge dryer A / or dryer B. The preheating temperature is 20-60°C and the purge time is 24-48h;

[0022] Step S5. High-temperature regeneration: After the preheating and purging is completed, heat dryer A and / or dryer B to maintain the regeneration temperature of dryer A and / or dryer B at 200-350° C. and continue purging for 48-72 hours.

[0023] Preferably, in step S1, the temperature of dryer A and / or dryer B is controlled to be 0-10° C., and the pressure adsorbed into dryer A and / or dryer B is -0.08-0 MPa.

[0024] Preferably, in step S2, the liquid phase adsorption temperature is controlled to be -60 to -10°C.

[0025] Preferably, the method further comprises the following steps:

[0026] Step S6. Cooling and standby: After the high-temperature regeneration is completed, turn off the nitrogen preheater and stop heating dryer A and / or dryer B. Continue purging until the temperature of dryer A and / or dryer B drops below 30°C. Evacuate dryer A and / or dryer B to -0.1 to -0.08 MPa and standby.

[0027] Preferably, the pressure of the hexafluorobutadiene gas raw material introduced into step S1 is 0.1-0.2 MPa.

[0028] Beneficial effects of this application:

[0029] This application is based on the properties of hexafluorobutadiene gas and creatively proposes a liquid phase adsorption water removal method. Through the coordinated optimization of device structure innovation and process methods, the dual goals of efficient water removal and adsorbent regeneration are achieved. Low-temperature liquid phase adsorption significantly improves the adsorption efficiency. Through the low-temperature adsorption process, hexafluorobutadiene gas is liquefied in a precooler and then adsorbed in liquid phase. Compared with traditional gas phase adsorption, liquid phase adsorption greatly improves the adsorption capacity and adsorption depth of the adsorbent for water. In the liquid phase, the intermolecular force is enhanced, and the capture efficiency of the adsorbent for trace water is improved. The regeneration process effectively suppresses carbon deposition and polymerization, solves the carbon deposition and polymerization problems caused by high temperature retention of hexafluorobutadiene during the regeneration process, and extends the service life of the adsorbent. This method can effectively avoid the problem of too low adsorption capacity of the adsorbent material due to the high temperature of the conventional gas phase adsorption method, and greatly improves the adsorption cycle and adsorption depth of the adsorbent. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a diagram of the device used in this application;

[0031] Figure 2 is the pre-adsorption path diagram;

[0032] Figure 3 is the low temperature adsorption path diagram;

[0033] Figure 4 This is the condensate recovery path diagram;

[0034] Figure 5 This is the preheating purge path diagram;

[0035] Figure identification: 1. Hexafluorobutadiene gas feed pipeline; 2. Nitrogen preheater; 3. Nitrogen inlet valve; 4. Dryer A; 5. Gas feed valve; 6. Liquid feed valve; 7. Nitrogen vent valve; 8. Condensate recovery valve; 9. Precooler; 10. Condensate recovery tank; 11. Dryer B; 12. Liquid discharge pipeline; 13. Waste gas vent pipeline; 14. Vacuum pipeline; 15. Vacuum valve; 16. Liquid discharge valve. DETAILED DESCRIPTION

[0036] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the specific implementation methods, structures, features and effects of the present invention are described in detail below in conjunction with the accompanying drawings and preferred embodiments.

[0037] Device embodiment

[0038] This embodiment provides a device for removing water from a hexafluorobutadiene liquid phase and regenerating an adsorbent, the device comprising a hexafluorobutadiene gas phase feed line 1, a nitrogen preheater 2, a dryer A4 and a dryer B11 arranged in parallel, a precooler 9, and a condensate recovery tank 10;

[0039] The bottom of dryer A4 and dryer B11 are connected to hexafluorobutadiene gas phase feed pipeline 1 through gas phase feed valve 5, connected to the liquid outlet of precooler 9 through liquid phase feed valve 6, and connected to condensate recovery tank 10 through condensate recovery valve 8;

[0040] The tops of dryer A4 and dryer B11 are connected to the outlet of nitrogen preheater 2 via nitrogen inlet valve 3 and connected to liquid discharge pipeline 12 via liquid discharge valve 16 respectively.

[0041] The dryers A4 and B11 are further connected to an exhaust gas venting pipeline 13 below, and a nitrogen venting valve 7 is provided on the exhaust gas venting pipeline 13 .

[0042] The upper portion of the condensate recovery tank 10 is also connected to a vacuum pipeline 14 , on which a vacuum valve 15 is provided.

[0043] Dryer A4 and dryer B11 adopt symmetrical piping arrangement, and the gas phase feed valve 5, liquid phase feed valve 6, condensate recovery valve 8, nitrogen inlet valve 3, and liquid phase discharge valve 16 are independently controlled.

[0044] Both dryer A4 and dryer B11 are equipped with external jackets and internal heating devices.

[0045] Principle of device implementation (in order to clearly describe the principle of device implementation, the operation of dryer A4 is taken as an example):

[0046] Pre-adsorption: The material path of hexafluorobutadiene gas is Figure 2 As shown by the red line in the middle, select dryer A4 that has completed regeneration and cooled to below 30°C. Close its nitrogen inlet valve 3, liquid discharge valve 16, and vacuum valve 15. Open the gas phase feed valve 5 of dryer A4, and introduce 0.1-0.2 MPa of hexafluorobutadiene gas into dryer A4 through the hexafluorobutadiene gas phase feed line 1. Start the refrigerant circulation in the external jacket of dryer A4, control the temperature of dryer A4 between 0°C and 10°C, and adsorb until the pressure in dryer A4 rises to -0.08-0 MPa. During the adsorption process, the hexafluorobutadiene gas is partially adsorbed by the adsorbent, and the released heat is discharged through the jacket refrigerant to maintain a low-temperature adsorption environment. Pre-adsorption prevents a large amount of heat release when hexafluorobutadiene first enters the molecular sieve, which would affect the low-temperature adsorption effect.

[0047] Low temperature adsorption: The specific path is Figure 3As shown by the green line in the middle, the gas phase feed valve 5 of the dryer A4 is kept open, and the liquid phase feed valve 6 is opened at the same time. After the hexafluorobutadiene gas is liquefied to -60 to -10°C through the precooler 9, it is introduced into the dryer A4 in liquid form. The liquid phase adsorption temperature in the dryer A4 is further controlled to -60 to -10°C by the external jacket refrigerant, so that the liquid phase material and the adsorbent are fully contacted to achieve deep water removal. The dried liquid phase after adsorption is transported to the liquid phase discharge pipeline 12 through the liquid phase discharge valve 16 and enters the downstream process.

[0048] Condensate recovery: The specific path is Figure 4 As shown by the middle blue line, close the gas phase feed valve 5, liquid phase feed valve 6, and liquid phase discharge valve 16 of dryer A4; open the condensate recovery valve 8 and condensate recovery tank 10, and control the temperature of the condensate recovery tank 10 to -60 to -10°C and the pressure to -0.05 to -0.02 MPa; use the pressure difference to transfer the residual liquid phase material in dryer A4 to the condensate recovery tank 10. After the pressure of dryer A4 and condensate recovery tank 10 is balanced, maintain it for 1 to 2 hours to ensure complete material recovery; the recovered condensate can be returned to the front end of the system for recycling.

[0049] Preheating and purging: The specific path is Figure 5 As shown by the yellow line in the middle, close the condensate recovery valve 8 of the dryer A4, open the nitrogen preheater 2 and the nitrogen inlet valve 3, heat the nitrogen to 20-60°C, and then pass it into the dryer A4; at the same time, open the nitrogen vent valve 7 to preheat and purge the dryer A4 for 24-48 hours; the purge exhaust gas is discharged through the exhaust vent pipeline 13.

[0050] High-temperature regeneration: After the preheating and purging is completed, start the internal heating device of the dryer A4, gradually increase the temperature to 200-350°C, maintain the regeneration temperature, and continuously introduce nitrogen for 48-72 hours to carry the desorbed moisture and impurities out through the nitrogen.

[0051] Cooling and standby: Turn off the internal heating device and nitrogen preheater 2 of dryer A4, continue to introduce nitrogen purge until the temperature of dryer A4 drops below 30°C; close the nitrogen inlet valve 3 and nitrogen vent valve 7, open the vacuum valve 15, and evacuate the dryer A4 to -0.1 to -0.08 MPa through the vacuum line 14. The dryer A4 enters the standby state.

[0052] The devices of the present application can be used synchronously to increase the water removal speed and can also be used alternately to achieve continuous production.

[0053] Synchronous use instructions: The two parallel dryers A4 and B11 of this application can be used synchronously to speed up the liquid phase water removal rate.

[0054] Alternating operation description: When dryer A4 executes steps S1 to S3 (adsorption stage), dryer B11 synchronously executes steps S4 to S6 (regeneration stage); by independently controlling the gas phase feed valve 5, liquid phase feed valve 6, nitrogen inlet valve 3 and other valves of dryer A4 and dryer B11, continuous production and regeneration cycle is achieved to ensure uninterrupted operation of the device.

[0055] The initial water content of the hexafluorobutadiene gas selected in Examples 1 to 3 was 0.1%.

[0056] Example 1

[0057] Based on the dewatering and regeneration device provided in this application, this embodiment provides a dewatering and regeneration method, which is specifically as follows:

[0058] Step S1. Pre-adsorption: Hexafluorobutadiene gas at a pressure of 0.15 MPa is directly introduced into a dryer after regeneration and cooling for adsorption, the dryer temperature is controlled at 10°C, and adsorption is performed until the pressure in the dryer is 0 MPa;

[0059] Step S2. Low temperature adsorption: The hexafluorobutadiene gas is liquefied by the precooler 9 and then passed into the dryer for liquid phase adsorption, and the liquid phase adsorption temperature is controlled to -30°C;

[0060] Step S3. Condensate recovery: After the liquid adsorption is completed, the liquid phase material in the dryer is transferred to the condensate recovery tank 10, and the condensate recovery tank 10 is controlled to have a temperature of -60°C and a pressure of -0.03MPa. The recovery is completed after 1.5h when the dryer and the condenser recovery tank are flat;

[0061] Step S4. Preheating and purging: After the recovery is completed, open the nitrogen preheater 2 to preheat the nitrogen and purge the dryer, the preheating temperature is 45 ° C, and the purge time is 30h;

[0062] Step S5. High-temperature regeneration: After the preheating and purging is completed, the dryer is heated to maintain the dryer regeneration temperature at 250°C and the purging is continued for 72 hours.

[0063] Step S6. Cooling and standby: After the high-temperature regeneration is completed, turn off the nitrogen preheater 2 and stop heating the dryer, continue purging until the dryer temperature drops below 30°C, and evacuate the dryer to -0.075 MPa for standby use.

[0064] After testing, the water content of hexafluorobutadiene gas after adsorption in the dryer was 0.15 ppm.

[0065] Example 2

[0066] Based on the dewatering and regeneration device provided in this application, this embodiment provides a dewatering and regeneration method, which is specifically as follows:

[0067] Step S1. Pre-adsorption: Hexafluorobutadiene gas at a pressure of 0.1 MPa is directly introduced into a dryer after regeneration and cooling for adsorption. The dryer temperature is controlled at 0°C and the pressure in the dryer is adsorbed to -0.08 MPa.

[0068] Step S2. Low temperature adsorption: The hexafluorobutadiene gas is liquefied by the precooler 9 and then passed into the dryer for liquid phase adsorption, and the liquid phase adsorption temperature is controlled to -60°C;

[0069] Step S3. Condensate recovery: After the liquid adsorption is completed, the liquid phase material in the dryer is transferred to the condensate recovery tank 10, and the condensate recovery tank 10 is controlled to have a temperature of -10°C and a pressure of -0.05MPa. The recovery is completed after the dryer and the condenser recovery tank are flattened for 1h;

[0070] Step S4. Preheating and purging: After the recovery is completed, open the nitrogen preheater 2 to preheat nitrogen and purge the dryer. The preheating temperature is 60°C and the purge time is 24h.

[0071] Step S5. High-temperature regeneration: After the preheating and purging is completed, the dryer is heated to maintain the dryer regeneration temperature at 350°C and the purging is continued for 60 hours.

[0072] Step S6. Cooling and standby: After the high-temperature regeneration is completed, turn off the nitrogen preheater 2 and stop heating the dryer, continue purging until the dryer temperature drops below 30°C, and evacuate the dryer to -0.1 MPa for standby use.

[0073] After testing, the water content of hexafluorobutadiene gas after adsorption in the dryer was 0.18 ppm.

[0074] Example 3

[0075] Based on the dewatering and regeneration device provided in this application, this embodiment provides a dewatering and regeneration method, which is specifically as follows:

[0076] Step S1. Pre-adsorption: Hexafluorobutadiene gas at a pressure of 0.2 MPa is directly introduced into a dryer after regeneration and cooling for adsorption. The dryer temperature is controlled at 5°C and the pressure in the dryer is adsorbed to -0.04 MPa.

[0077] Step S2. Low temperature adsorption: The hexafluorobutadiene gas is liquefied by the precooler 9 and then passed into the dryer for liquid phase adsorption, and the liquid phase adsorption temperature is controlled to -10°C;

[0078] Step S3. Condensate recovery: After the liquid adsorption is completed, the liquid phase material in the dryer is transferred to the condensate recovery tank 10, and the condensate recovery tank 10 is controlled to have a temperature of -30°C and a pressure of -0.05MPa. The recovery is completed after 2h when the dryer and the condenser recovery tank are flat;

[0079] Step S4. Preheating and purging: After the recovery is completed, open the nitrogen preheater 2 to preheat the nitrogen and purge the dryer. The preheating temperature is 20°C and the purge time is 48h.

[0080] Step S5. High-temperature regeneration: After the preheating and purging is completed, the dryer is heated to maintain the dryer regeneration temperature at 200°C and the purging is continued for 48 hours.

[0081] Step S6. Cooling and standby: After the high-temperature regeneration is completed, turn off the nitrogen preheater 2 and stop heating the dryer, continue purging until the dryer temperature drops below 30°C, and evacuate the dryer to -0.08 MPa for standby use.

[0082] After testing, the water content of hexafluorobutadiene gas after adsorption in the dryer was 0.16 ppm.

[0083] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as above in terms of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art can, without departing from the scope of the technical solution of the present invention, make some changes or modifications to equivalent embodiments using the technical contents disclosed above. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A device for liquid phase water removal and adsorbent regeneration of hexafluorobutadiene, characterized in that: The device comprises a hexafluorobutadiene gas phase feed pipeline (1), a nitrogen preheater (2), a dryer A (4) and a dryer B (11) arranged in parallel, a precooler (9) and a condensate recovery tank (10); The bottom of the dryer A (4) and the dryer B (11) are connected to the hexafluorobutadiene gas phase feed pipeline (1) through the gas phase feed valve (5), connected to the liquid outlet of the precooler (9) through the liquid phase feed valve (6), and connected to the condensate recovery tank (10) through the condensate recovery valve (8); The tops of the dryer A (4) and the dryer B (11) are connected to the outlet of the nitrogen preheater (2) via nitrogen inlet valves (3) and are connected to the liquid phase discharge pipeline (12) via liquid phase discharge valves (16).

2. The device for liquid phase water removal and adsorbent regeneration of hexafluorobutadiene according to claim 1, characterized in that: The dryer A (4) and the dryer B (11) are further connected to an exhaust gas venting pipeline (13) below, and a nitrogen venting valve (7) is provided on the exhaust gas venting pipeline (13).

3. The device for liquid phase water removal and adsorbent regeneration of hexafluorobutadiene according to claim 1, characterized in that: The upper portion of the condensate recovery tank (10) is also connected to a vacuum pipeline (14), and a vacuum valve (15) is provided on the vacuum pipeline (14).

4. The device for liquid phase water removal and adsorbent regeneration of hexafluorobutadiene according to claim 1, characterized in that: The dryer A (4) and the dryer B (11) are arranged in a symmetrical pipeline, and the gas phase feed valve (5), the liquid phase feed valve (6), the condensate recovery valve (8), the nitrogen inlet valve (3), and the liquid phase discharge valve (16) are independently controlled.

5. The device for liquid phase water removal and adsorbent regeneration of hexafluorobutadiene according to claim 1, characterized in that: The dryer A (4) and the dryer B (11) are both provided with an external jacket and an internal heating device.

6. A method for liquid-phase dehydration of hexafluorobutadiene and regeneration of an adsorbent, based on the device for liquid-phase dehydration of hexafluorobutadiene and regeneration of an adsorbent according to any one of claims 1 to 5, characterized in that: The steps include: Step S1. Pre-adsorption: Hexafluorobutadiene gas is directly introduced into the dryer A (4) and / or dryer B (11) after regeneration and cooling for adsorption; Step S2. Low-temperature adsorption: The hexafluorobutadiene gas raw material is liquefied in a precooler (9) and then passed into a dryer A (4) and / or a dryer B (11) for liquid phase adsorption; Step S3. Condensate recovery: After the liquid phase adsorption is completed, the liquid phase material in the dryer A (4) and / or dryer B (11) is transferred to the condensate recovery tank (10), and the temperature of the condensate recovery tank (10) is controlled to be -60 to -10°C and the pressure to be -0.05 to -0.02 MPa. The recovery is completed 1 to 2 hours after the pressure of the dryer A (4) and / or dryer B (11) and the condensate recovery tank (10) are equalized; Step S4. Preheating and purging: After the recovery is completed, open the nitrogen preheater (2) to preheat the nitrogen and purge the dryer A (4) and / or dryer B (11). The preheating temperature is 20 to 60°C and the purge time is 24 to 48 hours. Step S5. High-temperature regeneration: After the preheating and purging is completed, the dryer A (4) and / or the dryer B (11) are heated to maintain the regeneration temperature of the dryer A (4) and / or the dryer B (11) at 200-350°C, and the purging is continued for 48-72 hours.

7. The method for liquid phase dehydration and regeneration of hexafluorobutadiene according to claim 6, characterized in that: In step S1, the temperature of the dryer A (4) and / or the dryer B (11) is controlled to be 0-10°C, and the pressure adsorbed into the dryer A (4) and / or the dryer B (11) is -0.08-0 MPa.

8. The method for liquid phase dehydration and regeneration of hexafluorobutadiene according to claim 6, characterized in that: In step S2, the liquid phase adsorption temperature is controlled to be -60 to -10°C.

9. The method for liquid phase dehydration and regeneration of hexafluorobutadiene according to claim 6, characterized in that: The following steps are also included: Step S6. Cooling and standby: After the high-temperature regeneration is completed, the nitrogen preheater (2) is turned off and the heating of the dryer A (4) and / or the dryer B (11) is stopped. The purging is continued until the temperature of the dryer A (4) and / or the dryer B (11) drops below 30° C. The dryer A (4) and / or the dryer B (11) is evacuated to -0.1 to -0.08 MPa and is then set aside.

10. The method for liquid phase dehydration and regeneration of hexafluorobutadiene according to claim 6, characterized in that: In step S1, the pressure of the hexafluorobutadiene gas raw material is 0.1-0.2 MPa.

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