Method for removing trace amounts of fluorine-containing compounds produced during the production of perfluoromethylcyclohexanone

Abstract

The application belongs to the technical field of fluorinated chemical industry, and particularly relates to a method for removing trace fluorine-containing compounds generated in the production process of perfluorohexanone. The method for removing trace fluorine-containing compounds generated in the production process of perfluorohexanone comprises the following steps: taking a supported ionic liquid or an ionic liquid, mixing the ionic liquid with crude perfluorohexanone, stirring uniformly, removing air, starting stirring reaction when reaching a reaction temperature, and separating high-purity perfluorohexanone after the reaction is completed. The anion is one of Cl ‑ , Br ‑ , SCN ‑ . The method for removing trace fluorine-containing compounds generated in the production process of perfluorohexanone is environmentally friendly and safe, simple in process, cost-reducing and benefit-increasing, and solves the compatibility / selectivity problem through ionic liquid structure design and support carrier.

Description

Technical Field

[0001] The invention belongs to the technical field of fluorine chemical industry, and particularly relates to a method for removing trace fluorine-containing compounds generated in the production process of perfluorohexanone. Background Art

[0002] Perfluorohexanone (C6F 12 As a next-generation electronic device coolant and green fire extinguishing agent, perfluorohexanone (PFH) offers irreplaceable advantages in supercomputer chip cooling and data center thermal management. Its extremely high fluorine content (approximately 88% by mass) in its molecular structure imparts excellent dielectric properties (dielectric constant <1.5) and thermal stability (autoignition temperature >900°C), while meeting environmental requirements for both ozone depletion potential (ODP=0) and global warming potential (GWP=1). However, during industrial production, the synthetic pathway for perfluorohexanone (e.g., perfluoro-4-methyl-2-pentene oxidation) produces a variety of impurities with similar boiling points, including perfluoro-2-methyl-2-pentene (with a boiling point difference of <3°C), hydrofluorocarbon oligomers (dimers and trimers), and residual organic solvents (such as acetonitrile and tetrahydrofuran). These impurities are not only potentially biotoxic but, more critically, can cause electrochemical corrosion and signal interference in electronic devices. Studies have shown that even ppm-level hydrogen impurities can significantly reduce the lifespan of copper conductors on chips (>40%).

[0003] Traditional purification processes mainly rely on organic solvent extraction-multi-stage distillation coupling technology. Chinese patent CN104672072A extracts perfluorohexanone by adding organic reagents such as chloroalkanes, and then separates it through multi-stage distillation to obtain perfluorohexanone with a purity of 99.9%; Chinese patent CN116969825A discloses a method for continuous distillation and separation of perfluorohexanone using four-stage series distillation towers; Chinese patent CN115845421A uses potassium fluoride or cesium fluoride as a catalyst, and reacts with the addition of nucleophilic reagents such as benzyl chloride. After the reaction, the perfluorohexanone product is obtained through multiple distillations. The current mainstream method for separating trace by-products with close boiling points usually requires the addition of organic solvents, organic extractants and / or alkali metal catalysts, etc., which removes most of the by-products while introducing organic solvents. Subsequently, the perfluorohexanone needs to be purified through a series of multi-stage distillation towers, making the overall process expensive and time-consuming; the treatment of the large amount of organic waste solvents generated after extraction is also a very difficult problem. As a "designer solvent", ionic liquids can theoretically achieve highly selective separation of trace impurities in perfluorohexanone by regulating the anionic and cationic structures. Their near-zero vapor pressure characteristics can avoid secondary contamination of the product and meet the standards of electronic-grade chemicals. However, there are multiple technical obstacles in practical applications. Perfluorohexanone, as a strongly hydrophobic substance, has extremely poor compatibility with hydrophilic ionic liquids and cannot form an effective mass transfer interface. During the extraction process, metastable emulsification often occurs in the ionic liquid-perfluorohexanone mixed system, and the phase separation time is long, which seriously restricts the equipment throughput. Ionic liquids have poor selective control capabilities for impurities / perfluorohexanone, the azeotropic point shift is uncontrollable, and hydrogen bonding interference leads to asymmetric impurity removal rates. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to overcome the above-mentioned defects of the prior art and provide a method for removing trace fluorine-containing compounds generated during the production of perfluorohexanone. The method is environmentally friendly and safe, has a simple process, reduces costs and increases efficiency, and solves the compatibility / selectivity problem through ionic liquid structure design and loading carrier.

[0005] The method of removing trace fluorine-containing compounds generated during the production of perfluorohexanone comprises the following steps: taking a loaded ionic liquid or an ionic liquid, mixing it with a crude perfluorohexanone product, stirring it evenly, removing air, and starting a stirring reaction when the reaction temperature is reached; and separating and obtaining high-purity perfluorohexanone after the reaction is completed.

[0006] The loaded ionic liquid or the anion of the ionic liquid is Cl - Br - 、SCN - , at least one of the following;

[0007] The loaded ionic liquid or the cationic structural formula of the ionic liquid is:

[0008] ,

[0009] Wherein R1, R2, R3, R4 and R5 are H atoms or saturated or unsaturated hydrocarbon groups, alcoholic hydroxyl groups and amino groups containing 1 to 16 carbon atoms.

[0010] The fluorine-containing by-products in the crude perfluorohexanone product are one or more of perfluoro-2,3-epoxy-2-methylpentane, fluoro(4-methyl-2-pentene), perfluoro(2-methyl-2-pentene) and hexafluoropropylene trimer.

[0011] The method of loading the ionic liquid includes physical loading or chemical loading.

[0012] The physical load carrier is at least one of activated carbon, mesoporous silica, zeolite molecular sieve, aluminum fluoride, potassium fluoride, polystyrene resin, aluminum oxide, and diatomaceous earth.

[0013] The chemical loading carrier is at least one of silica gel, chlorinated polystyrene, divinylbenzene, ZSM-5 molecular sieve, SBA-15 molecular sieve, SBA-16 molecular sieve, MCM-4 molecular sieve, chitosan and polyethylene glycol.

[0014] The reaction temperature is 20℃~150℃.

[0015] The air removal operation is to introduce nitrogen and / or inert gas to replace the air in the kettle by bubbling.

[0016] The stirring method is magnetic stirring.

[0017] An organic solvent is added during the reaction under stirring, wherein the organic solvent is at least one of acetonitrile, dimethyl sulfoxide, N,N-dimethylformamide, ethylene glycol dimethyl ether, and diethylene glycol dimethyl ether.

[0018] Specifically, the method for removing trace fluorine-containing compounds generated during the production of perfluorohexanone comprises the following steps: adding a loaded ionic liquid or an ionic liquid and a crude perfluorohexanone product into a high-pressure reactor, stirring evenly, introducing nitrogen and / or an inert gas to replace the air in the reactor by bubbling, closing the reactor, and starting a stirring magnetic reaction when the temperature reaches 20°C to 150°C. After the reaction is completed, the reactor is cooled to room temperature and filtered to recover the product to obtain high-purity perfluorohexanone, and the purity of the product is tested by gas chromatography.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] (1) The ionic liquid loading method of the present invention completely avoids the introduction of organic solvents / catalysts, eliminates the risk of solvent residues and waste liquid treatment costs, and the product purity meets electronic grade standards.

[0021] (2) The single-stage reaction-separation process of the present invention replaces the traditional multi-stage distillation, significantly reducing equipment complexity and energy consumption.

[0022] (3) The ion liquid structure design (specific anion and cation combination) of the present application effectively improves the perfluorohexanone-ion liquid compatibility, inhibits emulsification, and strengthens the selective adsorption / reaction removal capacity for impurities. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 Gas chromatogram of the purified perfluorohexanone of Example 9. DETAILED DESCRIPTION

[0024] The present application will be further described below in combination with specific examples.

[0025] The materials, reagents and instruments used in the following examples of the present application can be purchased through commercial channels.

[0026] Preparation and detection of perfluorohexanone crude product: 198 g of perfluorohexanone solution and 2 g of perfluoro-2,3-epoxy-2-methylpentane were added to a stainless steel kettle, the kettle valve was closed, and magnetic stirring was performed at room temperature for 2 h. The kettle was opened, and the liquid part was taken for gas chromatography analysis. The content of impurities was defined according to the percentage of peak area content. Gas chromatography analysis showed that the perfluorohexanone contained 0.94% of perfluoro-2,3-epoxy-2-methylpentane. According to the above method, perfluoro-2,3-epoxy-2-methylpentane was replaced by perfluoro(4-methyl-2-pentene), perfluoro(2-methyl-2-pentene), and hexafluoropropylene trimer, respectively. Gas chromatography analysis showed that the perfluorohexanone crude solution contained 0.89% of perfluoro(4-methyl-2-pentene), the perfluorohexanone crude solution contained 0.91% of perfluoro(2-methyl-2-pentene), and the perfluorohexanone crude solution contained 1.06% of hexafluoropropylene trimer.

[0027] Example 1

[0028] The ion liquid structure is as follows: .

[0029] The method for removing trace amounts of fluorine-containing compounds generated in the production process of perfluorohexanone: perfluorohexanone crude solution containing perfluoro(2-methyl-2-pentene) was prepared, 40 g of perfluorohexanone crude solution and 2 g of the above ion liquid were taken in a 100 mL stainless steel reaction kettle, and after stirring uniformly, nitrogen was bubbled to replace the air in the kettle, 49°C magnetic stirring for 2 h, cooling to room temperature, and rectification recovery to obtain perfluorohexanone. Gas chromatography showed that the content of perfluoro(2-methyl-2-pentene) was 19 ppm.

[0030] Example 2

[0031] The ion liquid structure is as follows: .

[0032] The method for removing trace fluorine-containing compounds generated during the production of perfluorohexanone comprises preparing a crude perfluorohexanone solution containing perfluoro(2-methyl-2-pentene), taking 40 g of the crude perfluorohexanone solution and 2 g of the above-mentioned ionic liquid in a 100 mL stainless steel reactor, stirring evenly, introducing nitrogen to bubble to replace the air in the reactor, magnetically stirring at 30° C. for 2 hours, cooling to room temperature, and then rectifying and recovering to obtain pure perfluorohexanone, wherein gas chromatography shows that the perfluoro(2-methyl-2-pentene) content is less than the minimum detection line of 10 ppm.

[0033] Example 3

[0034] The structure of ionic liquid is as follows: .

[0035] The method for removing trace fluorine-containing compounds generated during the production of perfluorohexanone comprises preparing a crude perfluorohexanone solution containing perfluoro(4-methyl-2-pentene), taking 40 g of the crude perfluorohexanone solution and 2 g of the above-mentioned ionic liquid in a 100 mL stainless steel reaction kettle, then adding 20 mL of acetonitrile solvent, stirring evenly, introducing nitrogen to bubble to replace the air in the kettle, magnetically stirring at 80° C. for 10 hours, cooling to room temperature, and recovering by separation-rectification to obtain pure perfluorohexanone, wherein gas chromatography shows that the perfluoro(4-methyl-2-pentene) content is less than 10 ppm.

[0036] Example 4

[0037] The structure of ionic liquid is as follows: .

[0038] The method for removing trace fluorine-containing compounds generated during the production of perfluorohexanone comprises preparing a crude perfluorohexanone solution containing perfluoro-2,3-epoxy-2-methylpentane, taking 40 g of the crude perfluorohexanone solution and 2 g of the above-mentioned ionic liquid in a 100 mL stainless steel reactor, stirring evenly, introducing nitrogen to bubble to replace the air in the reactor, magnetically stirring at 40° C. for 2 hours, cooling to room temperature, and then distilling and recovering pure perfluorohexanone, wherein gas chromatography shows that the perfluoro-2,3-epoxy-2-methylpentane content is less than 10 ppm.

[0039] Example 5

[0040] The structure of ionic liquid is as follows: .

[0041] The method for removing trace amounts of fluorine-containing compounds produced during the production of perfluorohexanone: prepare a perfluorohexanone crude solution containing perfluoro-2,3-epoxy-2-methylpentane, take 40 g of the perfluorohexanone crude solution and 2 g of the above-mentioned ionic liquid in a 100 mL stainless steel reaction kettle, stir uniformly, then bubble in nitrogen to replace the air in the kettle, magnetically stir at 48°C for 2 h, cool to room temperature, and then recover the pure perfluorohexanone by rectification, which shows that the content of perfluoro-2,3-epoxy-2-methylpentane is less than 10 ppm by gas chromatography.

[0042] Example 6

[0043] The structure of the ionic liquid is as follows: .

[0044] Prepare a perfluorohexanone crude solution containing hexafluoropropylene trimer, take 40 g of the perfluorohexanone crude solution and 2 g of the above-mentioned ionic liquid in a 100 mL stainless steel reaction kettle, then add 20 mL of acetonitrile solvent, stir uniformly, then bubble in nitrogen to replace the air in the kettle, magnetically stir at 90°C for 10 h, cool to room temperature, and then recover the pure perfluorohexanone by liquid-liquid separation-rectification, which shows that the content of hexafluoropropylene trimer is 0.08% by gas chromatography.

[0045] Example 7

[0046] The structure of the ionic liquid is as follows: .

[0047] The method for removing trace amounts of fluorine-containing compounds produced during the production of perfluorohexanone: prepare a perfluorohexanone crude solution containing 0.2% hexafluoropropylene trimer, 0.5% perfluoro(4-methyl-2-pentene), 0.3% perfluoro(2-methyl-2-pentene), and 0.2% hexafluoropropylene dimer epoxide, take 40 g of the perfluorohexanone crude solution and 3 g of the above-mentioned ionic liquid in a 100 mL stainless steel reaction kettle, stir uniformly, then bubble in argon to replace the air in the kettle, magnetically stir at 90°C for 10 h, cool to room temperature, and then recover the pure perfluorohexanone by rectification, which shows that the total content of by-products is less than 0.004% by gas chromatography as shown in Figure 1 .

[0048] Physical loading of ionic liquid method:

[0049] The γ-alumina of Example 8 and Example 10, the basic alumina of Example 11, the activated carbon of Example 13 and Example 14, the mesoporous silica of Example 15 are physically loaded ionic liquids, and the preparation method thereof is prepared by the following steps: using the equal volume impregnation method commonly used in the art, taking activated carbon as the carrier, first refluxing the activated carbon with deionized water for 2h, filtering, and then drying at 80°C under vacuum, and calcining at 300°C under N2atmosphere for 2h to remove volatile impurities and stabilize the pore structure. The ionic liquid is dissolved in deionized water, stirred uniformly, the treated activated carbon carrier is weighed and added to the solution, and stirred under the condition of 80°C; after the deionized water is evaporated, it is dried in a vacuum oven at 80°C for 12h to obtain an activated carbon physically loaded ionic liquid. (The γ-alumina, basic alumina, mesoporous silica loaded ionic liquid can be obtained by replacing the above activated carbon and the corresponding ionic liquid in each example).

[0050] Chemically loaded ionic liquid method:

[0051] The SBA-15 molecular sieve of Example 9 and the chlorinated polystyrene (PS) of Example 12 are chemically loaded ionic liquids, and the preparation method thereof is prepared by the following steps: using the conventional chemical grafting method in the art, taking chlorinated polystyrene (PS) resin as the carrier and triazole bromide as the ionic liquid, weighing the chlorinated polystyrene resin microspheres into an acetonitrile solution, adding triazole according to the proportion of 1:1 of the number of monomers in the molecular sieve, adding triethylamine (0.5 times of triazole) as a catalyst, and refluxing under the condition of 80°C under nitrogen protection for 24h; after cooling, filtering, washing with ethanol for three times, and drying in a vacuum drying oven at 80°C for 12h; the obtained dried polystyrene triazole microspheres are added into toluene solvent, then 1.2 times of bromobutane of the molar amount of triazole is added dropwise through a constant pressure funnel, and the reaction is carried out under reflux stirring at 110°C for 12h. After the reaction is completed, it is cooled to room temperature, washed with ethanol for three times, and dried in a vacuum drying oven at 80°C for 12h to obtain chlorinated polystyrene resin loaded triazole bromide ionic liquid. (The SBA-15 molecular sieve is loaded by replacing the above chlorinated polystyrene (PS), and the corresponding ionic liquid in each example can be obtained).

[0052] Example 8

[0053] The structure of the ionic liquid is as follows: .

[0054] The method for removing trace amounts of fluorine-containing compounds produced in the production of perfluorohexanone: prepare a perfluorohexanone crude solution containing perfluoro(2-methyl-2-pentene), take 40 g of the perfluorohexanone crude solution and 3.6 g of the above-mentioned ionic liquid loaded on γ-alumina with a loading of 20 wt% in a 100 mL stainless steel reactor, bubble in nitrogen to replace the air in the reactor, magnetically stir at 49°C for 6 h, and after cooling to room temperature, filter to recover the perfluorohexanone product. Gas chromatography shows that the content of perfluoro(2-methyl-2-pentene) is less than 10 ppm.

[0055] Example 9

[0056] The structure of the ionic liquid is as follows: .

[0057] The method for removing trace amounts of fluorine-containing compounds produced in the production of perfluorohexanone: prepare a perfluorohexanone crude solution containing perfluoro(2-methyl-2-pentene), take 40 g of the perfluorohexanone crude solution and 3.6 g of the above-mentioned ionic liquid loaded on SBA-15 molecular sieves in a 100 mL stainless steel reactor, bubble in nitrogen to replace the air in the reactor, magnetically stir at room temperature for 6 h, and after cooling to room temperature, filter to recover the perfluorohexanone product. Gas chromatography shows that the content of perfluoro(2-methyl-2-pentene) is less than 10 ppm.

[0058] Example 10

[0059] The structure of the ionic liquid is as follows: .

[0060] The method for removing trace amounts of fluorine-containing compounds produced in the production of perfluorohexanone: prepare a perfluorohexanone crude solution containing perfluoro(4-methyl-2-pentene), take 40 g of the perfluorohexanone crude solution and 3.6 g of the above-mentioned ionic liquid loaded on γ-alumina with a loading of 30 wt% in a 100 mL stainless steel reactor, bubble in nitrogen to replace the air in the reactor, magnetically stir at room temperature for 6 h, and after cooling to room temperature, filter to recover the perfluorohexanone product. Gas chromatography shows that the content of perfluoro(4-methyl-2-pentene) is 0.13%.

[0061] Example 11

[0062] The structure of the ionic liquid is as follows: .

[0063] The method for removing trace fluorinated compounds generated during the production of perfluorohexanone includes preparing a crude perfluorohexanone solution containing perfluoro(4-methyl-2-pentene). 40 g of the crude perfluorohexanone solution and 3.6 g of the aforementioned ionic liquid loaded with 30 wt% basic alumina are placed in a 100 mL stainless steel reactor. Nitrogen is bubbled through the reactor to displace the air. The reactor is magnetically stirred at 80°C for 16 hours. After cooling to room temperature, the perfluorohexanone product is recovered by filtration. Gas chromatography shows that the perfluoro(4-methyl-2-pentene) content is less than 10 ppm.

[0064] Example 12

[0065] The structure of ionic liquid is as follows: .

[0066] The method for removing trace fluorinated compounds generated during the production of perfluorohexanone involves preparing a crude perfluorohexanone solution containing perfluoro-2,3-epoxy-2-methylpentane. 40 g of the crude perfluorohexanone solution and 3.6 g of the aforementioned ionic liquid chemically loaded on chlorinated polystyrene (PS) resin are placed in a 100 mL stainless steel reactor. Nitrogen is bubbled through the reactor to displace the air. The reactor is magnetically stirred at 40°C for 6 hours. After cooling to room temperature, the perfluorohexanone product is recovered by filtration. Gas chromatography shows the perfluoro-2,3-epoxy-2-methylpentane content is less than 10 ppm.

[0067] Example 13

[0068] The structure of ionic liquid is as follows: .

[0069] The method for removing trace fluorinated compounds generated during the production of perfluorohexanone includes preparing a crude perfluorohexanone solution of perfluoro-2,3-epoxy-2-methylpentane. 40 g of the crude perfluorohexanone solution and 3.6 g of the aforementioned ionic liquid loaded with 40 wt% activated carbon are placed in a 100 mL stainless steel reactor. Nitrogen is bubbled through the reactor to displace the air. The reactor is magnetically stirred at 48°C for 2 hours. After cooling to room temperature, the perfluorohexanone product is recovered by filtration. Gas chromatography shows that the perfluoro-2,3-epoxy-2-methylpentane content is less than 10 ppm.

[0070] Example 14

[0071] The structure of ionic liquid is as follows: .

[0072] The method for removing trace fluorinated compounds generated during the production of perfluorohexanone involves preparing a crude perfluorohexanone solution containing hexafluoropropylene trimer. 40 g of the crude perfluorohexanone solution and 3.6 g of the aforementioned ionic liquid loaded with 40 wt% activated carbon are placed in a 100 mL stainless steel reactor. Helium is bubbled through the reactor to displace the air, and the reaction mixture is magnetically stirred at 90°C for 16 hours. After cooling to room temperature, the perfluorohexanone product is recovered by filtration. Gas chromatography shows a hexafluoropropylene trimer content of 43 ppm.

[0073] Example 15

[0074] The structure of ionic liquid is as follows: .

[0075] The method for removing trace fluorinated compounds generated during the production of perfluorohexanone comprises preparing a crude perfluorohexanone solution containing 0.2% hexafluoropropylene trimer, 0.5% perfluoro(4-methyl-2-pentene), 0.3% perfluoro(2-methyl-2-pentene), and 0.2% hexafluoropropylene dimer epoxide. 40 g of the crude perfluorohexanone solution and 4 g of the aforementioned ionic liquid supported on mesoporous silica with a loading of 30 wt% are placed in a 100 mL stainless steel reactor. The mixture is magnetically stirred at 90°C for 10 hours, cooled to room temperature, and filtered to recover the perfluorohexanone product. Gas chromatography shows that the total content of by-products is less than 0.01%.

[0076] Comparative Example 1

[0077] The difference from Example 1 is that the ionic liquid used is tetrabutylammonium bromide, and gas chromatography shows a perfluoro(2-methyl-2-pentene) content of 0.79%. Quaternary ammonium ionic liquids lack active functional groups that react with the double bond of D2, and their boiling point is very close to that of perfluorohexanone. As a result, even after laboratory distillation, the removal of D2 is still poor.

[0078] Comparative Example 2

[0079] The difference from Example 10 is that the adsorption material used is gamma-alumina without an ionic liquid. Gas chromatography shows a perfluoro(4-methyl-2-pentene) content of 0.87%. Although gamma-alumina has a relatively large surface area and adsorption capacity, the adsorption method is physical adsorption, which is not selective for perfluorohexanone and D1. Therefore, it easily reaches saturation with perfluorohexanone, resulting in poor removal of D1.

Claims

1. A method for removing trace fluorine-containing compounds produced during the production of perfluorohexanone, characterized in that: Take the loaded ionic liquid or ionic liquid, mix it with the crude perfluorohexanone product, stir it evenly and remove the air, and start stirring the reaction when the reaction temperature is reached; after the reaction is completed, separate and obtain high-purity perfluorohexanone; The loaded ionic liquid or the anion of the ionic liquid is Cl - Br - 、SCN - One of the following; The loaded ionic liquid or the cationic structural formula of the ionic liquid is: ， Wherein R1, R2, R3, R4, and R5 are H atoms or saturated or unsaturated hydrocarbon groups, alcoholic hydroxyl groups, and amino groups containing 1 to 16 carbon atoms; The fluorine-containing by-products in the crude perfluorohexanone product are one or more of perfluoro-2,3-epoxy-2-methylpentane, perfluoro(4-methyl-2-pentene), perfluoro(2-methyl-2-pentene), and hexafluoropropylene trimer.

2. The method for removing trace fluorine-containing compounds generated in the production process of perfluorohexanone according to claim 1, characterized in that: The method of loading the ionic liquid includes physical loading or chemical loading.

3. The method for removing trace fluorine-containing compounds generated in the production process of perfluorohexanone according to claim 2, characterized in that: The physical load carrier is at least one of activated carbon, mesoporous silica, zeolite molecular sieve, aluminum fluoride, potassium fluoride, polystyrene resin, aluminum oxide, and diatomaceous earth.

4. The method for removing trace fluorine-containing compounds generated in the production process of perfluorohexanone according to claim 3, characterized in that: The chemical loading carrier is at least one of silica gel, chlorinated polystyrene, divinylbenzene, ZSM-5 molecular sieve, SBA-15 molecular sieve, SBA-16 molecular sieve, MCM-4 molecular sieve, chitosan and polyethylene glycol.

5. The method for removing trace fluorine-containing compounds generated in the production process of perfluorohexanone according to claim 1, characterized in that: The reaction temperature is 20℃~150℃.

6. The method for removing trace fluorine-containing compounds generated in the production process of perfluorohexanone according to claim 5, characterized in that: The air removal operation is to introduce nitrogen and / or inert gas to replace the air in the kettle by bubbling.

7. The method for removing trace fluorine-containing compounds generated in the production process of perfluorohexanone according to claim 1, characterized in that: The stirring method is magnetic stirring.

8. The method for removing trace fluorine-containing compounds generated in the production process of perfluorohexanone according to claim 1, characterized in that: An organic solvent is added during the reaction under stirring, wherein the organic solvent is at least one of acetonitrile, dimethyl sulfoxide, N,N-dimethylformamide, ethylene glycol dimethyl ether, and diethylene glycol dimethyl ether.

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