Purification device for electronic grade trifluoroacetyl fluoride and purification process using the same

Abstract

The present invention belongs to the technical field of trifluoroacetyl fluoride purification, and is specifically related to a purification device for electronic-grade trifluoroacetyl fluoride and a purification process using the same. The following steps are included: the industrial-grade trifluoroacetyl fluoride raw material in the trifluoroacetyl fluoride raw material tank enters the condenser, removes non-condensable gas, and is subsequently passed into a buffer tank; the gas in the buffer tank is sequentially passed into a light-removing tower for light component removal and a heavy-removing tower for heavy component removal, and then passed into an intermediate tank; the gas in the intermediate tank is sequentially passed into a 1# adsorption column equipped with modified UIO-66 for primary adsorption treatment and a 2# adsorption column equipped with modified activated alumina for secondary adsorption treatment, and after meeting the index of the electronic-grade trifluoroacetyl fluoride product, it is passed into a product tank to obtain an electronic-grade trifluoroacetyl fluoride product; the present invention utilizes the technology combined with distillation and adsorption, successfully outputs the product of electronic-grade trifluoroacetyl fluoride, and the process flow is circulated, effectively reducing the process flow and reducing energy consumption.

Description

Technical Field

[0001] The invention belongs to the technical field of trifluoroacetyl fluoride purification, and in particular relates to a purification device for electronic-grade trifluoroacetyl fluoride and a purification process using the same. Background Art

[0002] Trifluoroacetyl fluoride is a low GWP semiconductor etching gas and potential medium and low temperature refrigerant. It contains only three elements: C, O, and F. It is the second lightest substance among perfluorinated acyl fluorides. Electronic grade trifluoroacetyl fluoride has the following characteristics: fast etching rate, high aspect ratio, high selectivity, and can be etched nearly vertically, making it possible to manufacture small-volume, large-capacity 3D NAND. At the same time, it has the advantages of being environmentally friendly, with a GWP of less than 1, an atmospheric lifetime of only 6.9 days, and a low greenhouse effect. Electronic grade trifluoroacetyl fluoride is one of the current fluorine-containing electronic special gases that has both excellent etching performance and environmental performance.

[0003] At present, there is no unified standard for electronic-grade trifluoroacetyl fluoride. However, the demand indicators for electronic-grade trifluoroacetyl fluoride by semiconductor manufacturers are: CF3COF ≥ 99.99%, carbon monoxide + nitrogen + oxygen ≤ 20ppm, carbon dioxide ≤ 20ppm; other fluorocarbon compounds ≤ 40ppm; hydrogen fluoride ≤ 20ppm.

[0004] At present, there is no prior art for the preparation of electronic grade trifluoroacetyl fluoride. Patent CN112500285A discloses a continuous preparation method of trifluoroacetyl fluoride, but the purity of the trifluoroacetyl fluoride product obtained is 99.9%, which does not meet the electronic grade standard and cannot meet the production needs of electronic grade trifluoroacetyl fluoride. Summary of the invention

[0005] In view of the deficiencies in the prior art, the object of the present invention is to provide a purification device for electronic grade trifluoroacetyl fluoride, which is suitable for large-scale production.

[0006] The invention also provides a purification process using the same, thereby improving resource utilization and making the purity of trifluoroacetyl fluoride reach 99.99%.

[0007] The electronic-grade trifluoroacetyl fluoride purification device of the present invention comprises a trifluoroacetyl fluoride raw material tank, a condenser, a buffer tank, a light removal tower, a heavy removal tower, an intermediate tank, a No. 1 adsorption column, a No. 2 adsorption column, and a product tank which are connected in sequence, and the outlet of the No. 2 adsorption column is also provided with a branch pipeline connected to the inlet of the buffer tank.

[0008] Each pipeline of the purification device is provided with a pump and a valve according to actual operation requirements to realize the transportation of materials between the devices and control the flow direction of the materials.

[0009] Among them, the function of the condenser is to remove impurities such as oxygen and nitrogen in trifluoroacetyl fluoride and some non-condensable gases with higher boiling points, which can improve the separation quality of subsequent light removal towers and heavy removal towers and effectively extend the use time of subsequent adsorbents.

[0010] The buffer tank can not only serve as the aforementioned condenser discharge storage device, but also can return and store subsequent unqualified products for re-circulation processing, thereby reducing waste and achieving recycling.

[0011] The light removal tower and heavy removal tower play the role of distillation separation, which greatly reduces the content of impurities in trifluoroacetyl fluoride. If the product is qualified, it will be passed to the intermediate tank; if the product is unqualified, it will be passed to the buffer tank for reprocessing.

[0012] The intermediate tank is used as a storage device for the discharge of the above-mentioned deweighting tower.

[0013] 1# adsorption column and 2# adsorption column are mainly used to remove trace impurities remaining after distillation operation, including carbonyl fluoride, hexafluoropropylene, hexafluoropropylene oxide, carbon dioxide, trifluoromethane, etc. Each adsorber is equipped with a jacket, which can be passed through circulating water to control the adsorption temperature and take away the adsorption heat to prevent the adsorbent from sintering and the device from exploding due to adsorption heat. If the product is qualified after adsorption, it will be passed into the product tank; if it is unqualified, it will be passed into the buffer tank for reprocessing.

[0014] The purification process of the electronic-grade trifluoroacetyl fluoride purification device of the present invention comprises the following steps:

[0015] S1, the industrial-grade trifluoroacetyl fluoride raw material in the trifluoroacetyl fluoride raw material tank enters the condenser to remove the non-condensable gas, and then enters the buffer tank;

[0016] S2, the gas in the buffer tank is sequentially passed into a light removal tower to remove light components and a heavy removal tower to remove heavy components, and then passed into an intermediate tank;

[0017] S3, the gas in the intermediate tank is sequentially passed into the 1# adsorption column equipped with modified UIO-66 for primary adsorption treatment and the 2# adsorption column equipped with modified activated alumina for secondary adsorption treatment. After meeting the index of the electronic grade trifluoroacetyl fluoride product, the gas is passed into the product tank to obtain the electronic grade trifluoroacetyl fluoride product. If the gas does not meet the index of the electronic grade trifluoroacetyl fluoride product, the gas is passed into the buffer tank for re-treatment;

[0018] The purity of the industrial grade trifluoroacetyl fluoride raw material is 99%;

[0019] The electronic grade trifluoroacetyl fluoride product has the following indicators: CF3COF≥99.99%, carbon monoxide+nitrogen+oxygen≤20ppm, carbon dioxide≤20ppm; other fluorocarbon compounds≤40ppm; hydrogen fluoride≤20ppm.

[0020] The preparation method of the modified UIO-66 described in step S3 is:

[0021] A) dissolving ethylenediamine in isopropanol to obtain a solution;

[0022] B) adding UIO-66 to the above solution, heating and stirring, evaporating the solution to dryness, and washing UIO-66;

[0023] C) Then, UIO-66 was immersed in a mixed aqueous solution of La(NO3)3 and Ce(NO3)3, filtered and dried in an oven at 60°C.

[0024] The molar ratio of La(NO3)3 and Ce(NO3)3 is (0.5~2):1.

[0025] Furthermore, the preparation method of the modified UIO-66 described in step S3 is:

[0026] A) dissolving 0.5 mol of ethylenediamine in 50 ml of isopropanol to obtain a solution;

[0027] B) adding 0.1 mol UIO-66 to the above solution and stirring at 70°C, evaporating the solution to dryness, and washing UIO-66 with pure water;

[0028] C) Then, UIO-66 was immersed in a mixed solution of La(NO3)3 and Ce(NO3)3 for 8-12 h, filtered and dried in an oven at 60°C.

[0029] The preparation method of the modified activated alumina described in step S3 is:

[0030] a) adding aluminum chloride to aqueous ammonia, adjusting the pH to 10, allowing to stand, filtering and drying;

[0031] b) drying, calcining, and cooling to obtain activated alumina;

[0032] c) immersing the prepared activated alumina in a mixed aqueous solution of MgCl2, CaCl2, and La(NO3)3;

[0033] d) After drying, the modified activated alumina is obtained.

[0034] The molar ratio of MgCl2, CaCl2 and La(NO3)3 in step c) is (1-5):(1-5):1.

[0035] Furthermore, the preparation method of the modified activated alumina described in step S3 is:

[0036] a) Add aluminum chloride to 200 ml of 1 mol / L ammonia water, adjust the pH to 10, let stand for 3 hours, filter and dry;

[0037] b) calcining at 600°C for 3h after drying and obtaining activated alumina after cooling;

[0038] c) immersing the prepared activated alumina in a mixed aqueous solution of MgCl2, CaCl2, and La(NO3)3;

[0039] d) After drying, the modified activated alumina is obtained.

[0040] The condenser temperature in step S1 is -40 to -30°C, and the pressure is 0.4 to 0.8 MPa.

[0041] The light removal tower described in step S2 has a tower pressure of 0.2-0.4 MPa, a tower top temperature of -40--30°C, and the top of the tower is discharged and the bottom of the tower is extracted.

[0042] The deweighting tower described in step S2 has a tower pressure of 0.25-0.45 MPa, a tower top temperature of -20--10°C, extraction from the tower top and discharge from the tower bottom.

[0043] The temperature of the 1# adsorption column and the 2# adsorption column described in step S3 is 50-70°C.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] 1. The present invention utilizes a technology combining distillation and adsorption, uses industrial-grade trifluoroacetyl fluoride as raw material, and successfully produces electronic-grade trifluoroacetyl fluoride products, with the purity of the trifluoroacetyl fluoride product reaching more than 99.99%. The process flow of the present invention is cyclical, which effectively reduces the process flow and reduces energy consumption.

[0046] 2. The present invention uses a modified UIO-66 adsorbent in the 1# adsorption column, which exhibits the characteristics of large adsorption capacity, fast adsorption rate, good adsorption selectivity and high stability. The ethylenediamine molecules and the UIO-66 pores introduced with La and Ce ions synergistically enhance the adsorption of carbon dioxide, carbonyl fluoride and trifluoromethane.

[0047] 3. The present invention uses modified activated alumina in the 2# adsorption column, which has the advantages of large specific surface area, good stability, high mechanical strength and good regeneration. Mg, Ca, and La elements are loaded on the surface of activated alumina, which can form special chemical bonds with hexafluoropropylene near its surface, thereby enhancing the adsorption capacity of hexafluoropropylene. At the same time, the Mg, Ca, and La elements introduced into the activated alumina change the internal pore structure of the activated alumina, which can specifically adsorb hexafluoropropylene and hexafluoropropylene oxide. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 It is a schematic diagram of a purification device for electronic grade trifluoroacetyl fluoride of the present invention;

[0049] In the figure: 1. trifluoroacetyl fluoride raw material tank; 2. condenser; 3. buffer tank; 4. light removal tower; 5. heavy removal tower; 6. intermediate tank; 7. 1# adsorption column; 8. 2# adsorption column; 9. product tank. DETAILED DESCRIPTION

[0050] The present invention will be further described below with reference to the embodiments.

[0051] Unless otherwise specified, all raw materials used in the examples are commercially available.

[0052] The raw materials used in the examples and comparative examples are all industrial-grade trifluoroacetyl fluoride with the same composition and a purity of 99%. The analytical instruments for trifluoroacetyl fluoride include TCD gas chromatography and helium ion gas chromatography.

[0053] Example 1

[0054] like Figure 1 As shown, the trifluoroacetyl fluoride purification device comprises a trifluoroacetyl fluoride raw material tank 1 which is sequentially connected to a condenser 2, a buffer tank 3, a light removal tower 4, a heavy removal tower 5, an intermediate tank 6, a 1# adsorption column 7, a 2# adsorption column 8, and a product tank 9.

[0055] The function of the condenser 2 is to remove impurities such as oxygen and nitrogen in trifluoroacetyl fluoride and some non-condensable gases with higher boiling points, which can improve the separation quality of the subsequent light removal tower 4 and heavy removal tower 5 and effectively extend the subsequent use time of the adsorbent.

[0056] The buffer tank 3 can not only serve as a storage device for the output of the condenser 2, but also can store the subsequent unqualified products back and recycle them, thereby reducing waste and achieving recycling.

[0057] The light removal tower 4 and the heavy removal tower 5 play the role of distillation separation, which greatly reduces the content of impurities in trifluoroacetyl fluoride. If the product is qualified, it will be passed to the intermediate tank 6; if the product is unqualified, it will be passed to the buffer tank 3 for reprocessing.

[0058] The intermediate tank 6 is used as a storage device for the discharge of the deweighting tower 5 .

[0059] 1# adsorption column 7 and 2# adsorption column 8 are mainly used to remove trace impurities remaining after distillation operation, including carbonyl fluoride, hexafluoropropylene, hexafluoropropylene oxide, carbon dioxide, trifluoromethane, etc. Each adsorber is equipped with a jacket, and circulating water can be passed to control the adsorption temperature, take away the adsorption heat, and prevent the adsorbent from sintering and the device from exploding due to adsorption heat. If the product after adsorption is qualified, it is passed into the product tank 9; if it is unqualified, it is passed into the buffer tank 3 for reprocessing.

[0060] Example 2

[0061] The purification process using the purification device of electronic grade trifluoroacetyl fluoride described in Example 1 comprises the following steps:

[0062] S1, the industrial-grade trifluoroacetyl fluoride raw material in the trifluoroacetyl fluoride raw material tank 1 enters the condenser 2 to remove the non-condensable gas, and then enters the buffer tank 3;

[0063] S2, the gas in the buffer tank 3 is sequentially passed into the light removal tower 4 to remove light components and the heavy removal tower 5 to remove heavy components, and then passed into the intermediate tank 6;

[0064] S3, the gas in the intermediate tank 6 is sequentially passed into the 1# adsorption column 7 filled with modified UIO-66 for primary adsorption treatment and the 2# adsorption column 8 filled with modified activated alumina for secondary adsorption treatment, and after meeting the index of the electronic grade trifluoroacetyl fluoride product, it is passed into the product tank 9 to obtain the electronic grade trifluoroacetyl fluoride product;

[0065] The temperature of the condenser 2 in step S1 is -35°C and the pressure is 0.6MPa; the pressure of the light removal tower 4 in step S2 is 0.3MPa and the top temperature is -35°C, the pressure of the heavy removal tower 5 is 0.35MPa and the top temperature is -15°C; the temperature of the 1# adsorption column 7 in step S3 is 60°C, and the temperature of the 2# adsorption column 8 is 60°C.

[0066] The preparation method of the modified UIO-66 described in step S3 is as follows:

[0067] A) dissolving 0.5 mol of ethylenediamine in 50 ml of isopropanol to obtain a solution;

[0068] B) adding 0.1 mol UIO-66 to the above solution and stirring at 70°C, evaporating the solution to dryness, and washing UIO-66 with pure water;

[0069] C) Then, UIO-66 was immersed in a mixed aqueous solution of La(NO3)3 and Ce(NO3)3 for 12 h, filtered and dried in an oven at 60°C.

[0070] The molar ratio of La(NO3)3 and Ce(NO3)3 is 1:1.

[0071] The preparation method of the modified activated alumina in step S3 is as follows:

[0072] a) Add aluminum chloride to 200 ml of 1 mol / L ammonia water until the pH reaches 10, let stand for 3 hours, filter and dry.

[0073] b) calcining at 600°C for 3h after drying and obtaining activated alumina after cooling;

[0074] c) immersing the prepared activated alumina in a mixed aqueous solution of MgCl2, CaCl2, and La(NO3)3;

[0075] d) After drying, the modified activated alumina is obtained.

[0076] The molar ratio of MgCl2, CaCl2 and La(NO3)3 is 3:3:1.

[0077] Example 3

[0078] The purification process using the purification device of electronic grade trifluoroacetyl fluoride described in Example 1 comprises the following steps:

[0079] S1, the industrial-grade trifluoroacetyl fluoride raw material in the trifluoroacetyl fluoride raw material tank 1 enters the condenser 2 to remove the non-condensable gas, and then enters the buffer tank 3;

[0080] S2, the gas in the buffer tank 3 is sequentially passed into the light removal tower 4 to remove light components and the heavy removal tower 5 to remove heavy components, and then passed into the intermediate tank 6;

[0081] S3, the gas in the intermediate tank 6 is sequentially passed into the 1# adsorption column 7 filled with modified UIO-66 for primary adsorption treatment and the 2# adsorption column 8 filled with modified activated alumina for secondary adsorption treatment, and after meeting the index of the electronic grade trifluoroacetyl fluoride product, it is passed into the product tank 9 to obtain the electronic grade trifluoroacetyl fluoride product;

[0082] The temperature of the condenser 2 in step S1 is -40°C and the pressure is 0.4MPa; the pressure of the light removal tower 4 in step S2 is 0.2MPa and the top temperature is -40°C, the pressure of the heavy removal tower 5 is 0.25MPa and the top temperature is -20°C; the temperature of the 1# adsorption column 7 in step S3 is 50°C, and the temperature of the 2# adsorption column 8 is 50°C.

[0083] The preparation method of the modified UIO-66 described in step S3 is as follows:

[0084] A) dissolving 0.5 mol of ethylenediamine in 50 ml of isopropanol to obtain a solution;

[0085] B) adding 0.1 mol UIO-66 to the above solution and stirring at 70°C, evaporating the solution to dryness, and washing UIO-66 with pure water;

[0086] C) Then, UIO-66 was immersed in a mixed aqueous solution of La(NO3)3 and Ce(NO3)3 for 12 h, filtered and dried in an oven at 60°C.

[0087] The molar ratio of La(NO3)3 and Ce(NO3)3 is 0.5:1.

[0088] The preparation method of the modified activated alumina in step S3 is as follows:

[0089] a) Add aluminum chloride to 200 ml of 1 mol / L ammonia water until the pH reaches 10, let stand for 3 hours, filter and dry.

[0090] b) calcining at 600°C for 3h after drying and obtaining activated alumina after cooling;

[0091] c) immersing the prepared activated alumina in a mixed aqueous solution of MgCl2, CaCl2, and La(NO3)3;

[0092] d) After drying, the modified activated alumina is obtained.

[0093] The molar ratio of MgCl2, CaCl2 and La(NO3)3 is 1:1:1.

[0094] Example 4

[0095] The purification process using the purification device of electronic grade trifluoroacetyl fluoride described in Example 1 comprises the following steps:

[0096] S1, the industrial-grade trifluoroacetyl fluoride raw material in the trifluoroacetyl fluoride raw material tank 1 enters the condenser 2 to remove the non-condensable gas, and then enters the buffer tank 3;

[0097] S2, the gas in the buffer tank 3 is sequentially passed into the light removal tower 4 to remove light components and the heavy removal tower 5 to remove heavy components, and then passed into the intermediate tank 6;

[0098] S3, the gas in the intermediate tank 6 is sequentially passed into the 1# adsorption column 7 filled with modified UIO-66 for primary adsorption treatment and the 2# adsorption column 8 filled with modified activated alumina for secondary adsorption treatment, and after meeting the index of the electronic grade trifluoroacetyl fluoride product, it is passed into the product tank 9 to obtain the electronic grade trifluoroacetyl fluoride product;

[0099] The temperature of the condenser 2 in step S1 is -30°C and the pressure is 0.8MPa; the pressure of the light removal tower 4 in step S2 is 0.4MPa and the top temperature is -30°C, the pressure of the heavy removal tower 5 is 0.45MPa and the top temperature is -10°C; the temperature of the 1# adsorption column 7 in step S3 is 70°C, and the temperature of the 2# adsorption column 8 is 70°C.

[0100] The preparation method of the modified UIO-66 described in step S3 is as follows:

[0101] A) dissolving 0.5 mol of ethylenediamine in 50 ml of isopropanol to obtain a solution;

[0102] B) adding 0.1 mol UIO-66 to the above solution and stirring at 70°C, evaporating the solution to dryness, and washing UIO-66 with pure water;

[0103] C) Then, UIO-66 was immersed in a mixed aqueous solution of La(NO3)3 and Ce(NO3)3 for 12 h, filtered and dried in an oven at 60°C.

[0104] The molar ratio of La(NO3)3 and Ce(NO3)3 is 2:1.

[0105] The preparation method of the modified activated alumina in step S3 is as follows:

[0106] a) Add aluminum chloride to 200 ml of 1 mol / L ammonia water until the pH reaches 10, let stand for 3 hours, filter and dry.

[0107] b) calcining at 600°C for 3h after drying and obtaining activated alumina after cooling;

[0108] c) immersing the prepared activated alumina in a mixed aqueous solution of MgCl2, CaCl2, and La(NO3)3;

[0109] d) After drying, the modified activated alumina is obtained.

[0110] The molar ratio of MgCl2, CaCl2 and La(NO3)3 is 5:5:1.

[0111] Comparative Example 1

[0112] The difference between this comparative example and Example 2 is that the UIO-66 in adsorber #1 is not subjected to step C).

[0113] Comparative Example 2

[0114] The difference between this comparative example and Example 2 is that the activated alumina in adsorber #2 is not subjected to the treatment of steps c) and d).

[0115] Performance Testing

[0116] The purified products obtained in Examples 2-4 and Comparative Examples 1-2 were tested for the contents of various impurities using gas chromatography. The results are shown in Table 1.

[0117] Table 1 Impurity content of products in Examples 2 to 4 and Comparative Examples 1 to 2 (unit: ppm)

[0118]

[0119] It can be seen from Examples 2 to 4 that electronic grade trifluoroacetyl fluoride can be successfully produced when modified UIO-66 and modified activated alumina are used as adsorbents.

[0120] Comparison of the embodiment with comparative example 1 shows that the introduction of La and Ce enhances the adsorption of carbon dioxide, carbonyl fluoride and trifluoromethane by UIO-66. This is because the ethylenediamine molecules have a synergistic effect with the UIO-66 pores into which La and Ce ions are introduced.

[0121] It can be seen from the comparison between the embodiment and comparative example 2 that the introduction of Mg, Ca, and La strengthens the adsorption of hexafluoropropylene and hexafluoropropylene oxide by the activated alumina. This is because the Mg, Ca, and La elements are loaded on the surface of the activated alumina and can form special chemical bonds with the hexafluoropropylene near its surface, thereby strengthening the adsorption capacity of hexafluoropropylene. At the same time, the Mg, Ca, and La elements introduced into the activated alumina change the internal pore structure of the activated alumina, which can specifically adsorb hexafluoropropylene and hexafluoropropylene oxide.

Claims

1. A purification process for a purification device for electronic grade trifluoroacetyl fluoride, characterized in that: The following steps are involved: S1, the industrial-grade trifluoroacetyl fluoride raw material in the trifluoroacetyl fluoride raw material tank (1) enters the condenser (2), removes the non-condensable gas, and then enters the buffer tank (3); S2, the gas in the buffer tank (3) is sequentially passed into the light removal tower (4) to remove light components and into the heavy removal tower (5) to remove heavy components, and then passed into the intermediate tank (6); S3, the gas in the intermediate tank (6) is sequentially passed into the No. 1 adsorption column (7) filled with modified UIO-66 for primary adsorption treatment and the No. 2 adsorption column (8) filled with modified activated alumina for secondary adsorption treatment. When the gas meets the index of the electronic grade trifluoroacetyl fluoride product, it is passed into the product tank (9) to obtain the electronic grade trifluoroacetyl fluoride product. If the gas does not meet the index of the electronic grade trifluoroacetyl fluoride product, it is passed into the buffer tank (3) for re-treatment; The purity of the industrial grade trifluoroacetyl fluoride raw material is 99%; The electronic grade trifluoroacetyl fluoride product has the following indicators: CF3COF≥99.99%, carbon monoxide+nitrogen+oxygen≤20ppm, carbon dioxide≤20ppm; other fluorocarbon compounds≤40ppm; hydrogen fluoride≤20ppm.

2. The purification process of the purification device for electronic grade trifluoroacetyl fluoride according to claim 1, characterized in that: The preparation method of the modified UIO-66 described in step S3 is: A) dissolving ethylenediamine in isopropanol to obtain a solution; B) adding UIO-66 to the above solution, heating and stirring, evaporating the solution to dryness, and washing UIO-66; C) Then, UIO-66 is immersed in a mixed aqueous solution of La(NO3)3 and Ce(NO3)3, and then filtered and dried.

3. The purification process of the purification device for electronic grade trifluoroacetyl fluoride according to claim 2, characterized in that: The molar ratio of La(NO3)3 and Ce(NO3)3 is (0.5~2):

1.

4. The purification process of the purification device for electronic grade trifluoroacetyl fluoride according to claim 1, characterized in that: The preparation method of the modified activated alumina described in step S3 is: a) adding aluminum chloride to aqueous ammonia, allowing to stand, filtering and drying; b) drying, calcining, and cooling to obtain activated alumina; c) immersing the prepared activated alumina in a mixed aqueous solution of MgCl2, CaCl2, and La(NO3)3; d) After drying, the modified activated alumina is obtained.

5. The purification process of the purification device for electronic grade trifluoroacetyl fluoride according to claim 4, characterized in that: The molar ratio of MgCl2, CaCl2 and La(NO3)3 in step c) is (1-5):(1-5):

1.

6. The purification process of the electronic grade trifluoroacetyl fluoride purification device according to claim 4, characterized in that: The aluminum chloride is added into the ammonia water to control the pH to 10.

7. The purification process of the purification device for electronic grade trifluoroacetyl fluoride according to claim 1, characterized in that: The temperature of the condenser (2) described in step S1 is -40 to -30°C, and the pressure is 0.4 to 0.8 MPa.

8. The purification process of the purification device for electronic grade trifluoroacetyl fluoride according to claim 1, characterized in that: The light-removal tower (4) described in step S2 has a tower pressure of 0.2 to 0.4 MPa, a tower top temperature of -40 to -30°C, and the top of the tower is discharged to the outside, and the bottom of the tower is taken out. The heavy-removal tower (5) described in step S2 has a tower pressure of 0.25 to 0.45 MPa, a tower top temperature of -20 to -10°C, and the top of the tower is taken out, and the bottom of the tower is discharged to the outside.

9. The purification process of the electronic grade trifluoroacetyl fluoride purification device according to claim 1, characterized in that: The temperature of the 1# adsorption column (7) and the 2# adsorption column (8) described in step S3 is 50-70°C.

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