A production device of high-purity difluoroacetyl fluoride

Abstract

The application relates to the technical field of difluoroacetyl fluoride preparation, and discloses a production device for high-purity difluoroacetyl fluoride, which comprises a raw material storage tank, a cracking tower, a buffer tank, a light-removing tower, a heavy-removing tower and a product tank which are sequentially arranged, a first cooler is arranged between the cracking tower and the buffer tank, a second cooler is arranged at the discharging position of the upper end of the light-removing tower, a third cooler is arranged at the upper end of the heavy-removing tower, and the product tank is connected with the third cooler and the heavy-removing tower. The application can prepare difluoroacetyl fluoride with a purity of more than 99.5%.

Description

Technical Field

[0001] This application relates to the technical field of difluoroacetyl fluoride preparation, and in particular to a production apparatus for high-purity difluoroacetyl fluoride. Background Technology

[0002] Difluoroacetyl fluoride is an extremely important fluorine-containing intermediate. Currently, research and development of difluoroacetyl fluoride is still in its initial stages. It is mainly used in the preparation of various fungicides, pharmaceuticals, and pesticides. Therefore, difluoroacetyl fluoride has high industrial application value, and actively carrying out research on its preparation and application is of vital importance to the development of fluorochemical enterprises.

[0003] The current method for preparing difluoroacetyl fluoride involves adding trifluoroacetic acid and oxygen separately to a reaction vessel, heating the vessel to approximately 180°C to initiate the reaction, and controlling the oxygen content within the vessel. During the reaction, the pressure inside the vessel needs to be continuously reduced to achieve a stable product output. After the reaction, the product needs to be purified through distillation and filtration. This preparation process requires strict control over oxygen content and is technically challenging, making it unsuitable for industrial production.

[0004] Another preparation process involves mixing trifluoroacetic anhydride and aluminum fluoride in a certain proportion, placing them in a reaction vessel, and reacting them at a temperature of 30–40°C and a pressure of 0.1–0.2 MPa. After the reaction, the product in the reaction vessel is washed with water, and then subjected to distillation and filtration to finally obtain difluoroacetyl fluoride. This preparation process generates a certain amount of byproducts, requires high purification standards, and the purity of the obtained difluoroacetyl fluoride is generally around 98%. Therefore, exploring a more suitable method for industrial production and obtaining high-purity difluoroacetyl fluoride remains a key research focus. Utility Model Content

[0005] This application provides a production apparatus for high-purity difluoroacetyl fluoride, capable of producing difluoroacetyl fluoride with a purity of over 99.5%. Furthermore, the production apparatus of this application is simple and stable, providing strong technical support and guarantee for fields that have a demand for high-purity difluoroacetyl fluoride, and promoting the development and progress of related industries.

[0006] The technical solution adopted in this application is as follows:

[0007] A production apparatus for high-purity difluoroacetyl fluoride includes a raw material storage tank, a cracking tower, a buffer tank, a light-weight removal tower, a heavy-weight removal tower, and a product tank arranged in sequence. A first cooler is provided between the cracking tower and the buffer tank. A second cooler is provided at the upper discharge point of the light-weight removal tower. A third cooler is provided at the upper end of the heavy-weight removal tower. The product tank is connected to the heavy-weight removal tower through the third cooler.

[0008] By adopting the above technical solution, this application prepares difluoroacetyl fluoride through a cracking tower. For example, the raw material can be 1,1,2,2-tetrafluoroethyl methyl ether, and a corresponding catalyst is selected in the cracking tower to promote the cracking reaction. By connecting the light removal tower and the heavy removal tower in series, the product undergoes multiple distillations, thereby obtaining difluoroacetyl fluoride with a purity of more than 99.5% at the top of the heavy removal tower. The production equipment is simple, easy to control and operate, and suitable for industrial production.

[0009] Optionally, a vaporizer is provided between the raw material storage tank and the pyrolysis tower.

[0010] By adopting the above technical solution, the raw materials are vaporized through a vaporizer, thereby making the reaction in the cracking tower faster and more complete, and promoting the improvement of product conversion rate.

[0011] Optionally, the buffer tank is connected to a fourth cooler.

[0012] By adopting the above technical solution, the mixed gas from the cracking tower is condensed and then enters the buffer tank. The gas in the buffer tank is separated into monofluoromethane by the fourth cooler, thereby obtaining crude difluoroacetyl fluoride.

[0013] Optionally, the fourth cooler uses -60°C refrigerant for condensation, while the first, second, and third coolers use -30°C refrigerant for condensation.

[0014] By adopting the above technical solution, the refrigerant condensation temperature at different locations is controlled according to the different components at different stages, thereby achieving the effect of condensation separation.

[0015] Optionally, the outer wall of the buffer tank is detachably provided with an insulation layer, and the buffer tank is provided with a clamping assembly for clamping the insulation layer.

[0016] By adopting the above technical solution, the insulation performance of the buffer tank is improved through the insulation layer.

[0017] Optionally, the clamping assembly includes an abutment plate, a first connecting strip disposed on the abutment plate, and a second connecting strip disposed on the abutment plate, wherein the first connecting strip and the second connecting strip are connected to clamp the insulation layer.

[0018] By adopting the above technical solution, the insulation layer can be clamped to the side wall of the buffer tank by the cooperation of the first connecting strip and the connecting strip.

[0019] Optionally, a connecting block is provided at the end of the first connecting strip away from the abutment plate, the second connecting strip slides through the connecting block, and a positioning element is provided on the connecting block for positioning the second connecting strip to prevent the second connecting strip from sliding out of the connecting block.

[0020] By adopting the above technical solution, the second connecting strip passes through the connecting block, that is, the second connecting strip can be connected to the connecting block by the positioning member.

[0021] Optionally, the positioning element includes a positioning rod slidably connected to the connecting block and an elastic element disposed between the positioning rod and the connecting block. The second connecting strip has an abutment groove on the side facing away from the insulation layer, and the elastic element can drive the positioning rod to be inserted into the abutment groove.

[0022] By adopting the above technical solution, when the side wall of the positioning rod abuts against the abutting surface, the second connecting strip can be prevented from sliding out of the connecting block.

[0023] Optionally, the abutment plate is provided with an arc-shaped plate, the arc-shaped plate is provided with an extension block, and a bolt is threaded through the extension block and the bolt is threaded to the side wall of the abutment plate.

[0024] By adopting the above technical solution, it can better adhere to the insulation layer.

[0025] In summary, this application includes at least one of the following beneficial effects:

[0026] 1. The high-purity difluoroacetyl fluoride preparation apparatus provided in this application has a simple structure and process, and is highly practical and has the prospect of industrial production. Through a series of operations of cracking and separation, difluoroacetyl fluoride with a purity of over 99.5% is successfully prepared, and most of the raw materials that have not been completely cracked can be recycled. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of this application;

[0028] Figure 2 This is a schematic diagram of the buffer tank in Embodiment 2 of this application;

[0029] Figure 3 This is a schematic diagram illustrating the positioning element in Embodiment 2 of this application.

[0030] Explanation of reference numerals in the attached drawings: 1. Raw material storage tank; 2. Cracking tower; 3. Buffer tank; 4. Light weight removal tower; 5. Heavy weight removal tower; 6. Product tank; 7. First cooler; 8. Second cooler; 9. Third cooler; 10. Vaporizer; 11. Fourth cooler; 12. Raw material pump; 13. Feed pump; 14. Light weight removal pump; 15. Recovery pump; 16. Insulation layer; 17. Clamping assembly; 171. Abutment plate; 172. First connecting strip; 173. Second connecting strip; 18. Connecting block; 19. Positioning element; 191. Positioning rod; 192. Elastic element; 20. Abutment groove; 21. Arc plate; 22. Extension block; 23. Bolt. Detailed Implementation

[0031] The present application will be further described in detail below with reference to the accompanying drawings.

[0032] Example 1

[0033] This application discloses an apparatus for producing high-purity difluoroacetyl fluoride. (Refer to...) Figure 1 The production apparatus in this application includes a raw material storage tank 1, a cracking tower 2, a buffer tank 3, a light-weight removal tower 4, a heavy-weight removal tower 5, and a product tank 6 arranged in sequence. A first cooler 7 is provided between the cracking tower 2 and the buffer tank 3. A second cooler 8 is provided at the upper discharge end of the light-weight removal tower 4. A third cooler 9 is provided at the upper end of the heavy-weight removal tower 5. The product tank 6 is connected to the heavy-weight removal tower 5 through the third cooler 9.

[0034] In this embodiment, the raw material is selected from 1,1,2,2-tetrafluoroethyl methyl ether and stored in raw material storage tank 1. A vaporizer 10 is installed between raw material storage tank 1 and cracking tower 2. The raw material is sent into vaporizer 10 by raw material pump 12 and then enters cracking tower 2. In vaporizer 10, 1,1,2,2-tetrafluoroethyl methyl ether is vaporized and sent to cracking tower 2 to be cracked into a mixed gas of difluoroacetyl fluoride and monofluoromethane. The mixed gas is condensed by first cooler 7 and then enters buffer tank 3.

[0035] The cracking tower 2 is filled with a catalyst to promote the cracking reaction; in this embodiment, the catalyst is selected from alumina. The cracking tower 2 is equipped with a nitrogen inlet and an activation gas inlet. The structure of the cracking tower 2 is the existing structure and will not be described in detail here. Before use, the cracking tower 2 is purged with N2 while simultaneously heating it with heat transfer oil (240–260°C). After the moisture in the cracking tower 2 stabilizes, trifluoromethane is switched to be used as the activator to activate the catalyst. After activation, N2 is switched back to be used for purging. After thorough purging, the catalyst is activated and ready for use. When the raw material is fed into the cracking tower 2 for reaction, the pressure for the cracking reaction in the cracking tower 2 is 0.5–0.8 MPa and the temperature is 180–220°C.

[0036] The mixed gas obtained from the reaction in cracking tower 2 is condensed by the first cooler 7 and then enters buffer tank 3. A fourth cooler 11 is installed at the upper end of buffer tank 3. The mixed gas in cracking tower 2 includes monofluoromethane, difluoroacetyl fluoride, and raw materials. The fourth cooler 11 condenses the gas in buffer tank 3, thereby initially separating monofluoromethane and obtaining crude difluoroacetyl fluoride in buffer tank 3. In this embodiment, the fourth cooler 11 uses a -60℃ refrigerant for condensation, resulting in better separation.

[0037] A feed pump 13 is installed between the buffer tank 3 and the light-weight product removal tower 4. The feed pump 13 feeds the crude difluoroacetyl fluoride from the buffer tank 3 into the light-weight product removal tower 4. The boiling point of monofluoromethane is much lower than that of difluoroacetyl fluoride. By controlling the temperature of the light-weight product removal tower 4 to be higher than the boiling point of monofluoromethane but lower than that of difluoroacetyl fluoride, the purpose of removing light-weight components is achieved. Therefore, the monofluoromethane in the crude difluoroacetyl fluoride is discharged from the top of the light-weight product removal tower 4. The pressure in the light-weight product removal tower 4 is controlled at 0.4-1 MPa for distillation, and the temperature at the bottom of the tower can be controlled between 40-80℃. The temperature at the bottom of the tower is controlled according to the pressure in the light-weight product removal tower 4; the higher the pressure, the higher the temperature can be. A second cooler 8 is installed at the top of the light-weight product removal tower 4, and the second cooler 8 uses a -30℃ refrigerant for condensation. In the light emission removal tower 4, difluoroacetyl fluoride is the heavy component and is distributed at the bottom of the tower, while monofluoromethane is enriched at the top of the tower and is intermittently discharged after passing through the second cooler 8, entering the tail gas pipeline for subsequent tail gas collection and treatment.

[0038] A light-weight removal pump 14 is installed between the light-weight removal tower 4 and the heavy-weight removal tower 5. Pump 14 is used to feed the material from the bottom of the light-weight removal tower 4 into the heavy-weight removal tower 5. The components at this point mainly include difluoroacetyl fluoride and incompletely cracked 1,1,2,2-tetrafluoroethyl methyl ether. The boiling point of 1,1,2,2-tetrafluoroethyl methyl ether is higher than that of difluoroacetyl fluoride; therefore, in the heavy-weight removal tower 5, the temperature is controlled to be higher than the boiling point of difluoroacetyl fluoride but lower than the boiling point of 1,1,2,2-tetrafluoroethyl methyl ether. 1,1,2,2-tetrafluoroethyl methyl ether, as a heavy component, is distributed at the bottom of the tower, while difluoroacetyl fluoride, as a light component, is distributed at the top and discharged from the top. A third cooler 9 is installed at the top of the heavy-weight removal tower 5, using a -30°C refrigerant for condensation. The difluoroacetyl fluoride discharged from the third cooler 9 enters the product tank 6 for filling and storage. The raw material 1,1,2,2-tetrafluoroethyl methyl ether at the bottom of the tower is discharged and recycled by a recovery pump 15. For example, the pressure of the deweighting tower 5 can be 0.4-1 MPa for distillation, and the temperature of the tower bottom can be between 60-90°C. The pumps used in this embodiment are all existing pumps, such as diaphragm pumps, and all equipment is fluoropolymer-lined, including pipelines and valves.

[0039] The implementation principle of a high-purity difluoroacetyl fluoride production device according to an embodiment of this application is as follows: 1,1,2,2-tetrafluoroethyl methyl ether raw material in raw material storage tank 1 is transported to vaporizer 10. In vaporizer 10, 1,1,2,2-tetrafluoroethyl methyl ether is vaporized and sent to cracking tower 2 for cracking into a mixed gas of difluoroacetyl fluoride and monofluoromethane. The mixed gas is condensed by first cooler 7 and then enters buffer tank 3. The gas in buffer tank 3 undergoes simple separation of monofluoromethane by fourth cooler 11 to obtain crude difluoroacetyl fluoride. Feed pump 13 feeds the crude difluoroacetyl fluoride into light-light removal tower 4. Monofluoromethane is enriched at the top of light-light removal tower 4 and discharged intermittently. The material at the bottom of light-light removal tower 4 is fed into heavy removal tower 5 by light-light removal pump 14. The raw material 1,1,2,2-tetrafluoroethyl methyl ether enriched at the bottom of heavy removal tower 5 is recovered and reused by recovery pump 15. Difluoroacetyl fluoride with a purity of over 99.5% is collected from the top of the tower and transported to product tank 6 for low-temperature storage.

[0040] Example 2

[0041] Reference Figure 2 and Figure 3 The difference between this embodiment and Embodiment 1 is that an insulation layer 16 is installed on the surface of the buffer tank 3. The insulation layer 16 is made of insulation material such as rubber, and the buffer tank 3 is equipped with a clamping assembly 17 to fix the insulation layer 16. The clamping assembly 17 includes an abutment plate 171 and a first connecting strip 172 and a second connecting strip 173 installed on the abutment plate 171. The first connecting strip 172 and the second connecting strip 173 are connected to each other, thereby clamping the insulation layer 16 to the surface of the buffer tank 3. Multiple first connecting strips 172 and second connecting strips 173 can be arranged along the length direction of the abutment plate 171. A connecting block 18 is fixed to one end of the first connecting strip 172, and the second connecting strip 173 slides through the connecting block 18. A positioning element 19 is installed on the connecting block 18, which restricts the second connecting strip 173 from sliding out of the connecting block 18, thereby clamping the insulation layer 16.

[0042] The positioning element 19 includes a positioning rod 191 slidably connected to the connecting block 18 and an elastic element 192 installed between the positioning rod 191 and the connecting block 18. The elastic element 192 is a spring. In its natural state, one end of the positioning rod 191 is located within the inner cavity of the connecting block 18. The second connecting strip 173 has multiple abutment grooves 20 on the side facing away from the insulation layer 16. Under the action of the spring, the positioning rod 191 is inserted into the abutment grooves 20, thereby restricting the movement of the second connecting strip 173.

[0043] Furthermore, curved plates 21 are installed on both sides of the abutment plate 171. The abutment plate 171 abuts against the edge of the insulation layer 16, and the curved plates 21 press tightly against the surface of the insulation layer 16. A friction layer, such as rubber, can be provided on the side of the curved plate 21 closest to the insulation layer 16 to increase the friction with the insulation layer 16. An extension block 22 is fixed on the curved plate 21, and a bolt 23 passes through the extension block 22. The bolt 23 passes through the extension block 22 and is threaded onto the abutment plate 171. When the head of the bolt 23 abuts against the extension block 22, it drives the curved plate 21 to move towards the abutment plate 171 and abut against the surface of the abutment plate 171, thereby causing the curved plate 21 to cause a certain displacement of the insulation layer 16, so that the insulation layer 16 is in a taut state.

[0044] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A production apparatus for high-purity difluoroacetyl fluoride, characterized in that: The system includes a raw material storage tank (1), a cracking tower (2), a buffer tank (3), a light-weight removal tower (4), a heavy-weight removal tower (5), and a product tank (6) arranged in sequence. A first cooler (7) is provided between the cracking tower (2) and the buffer tank (3). A second cooler (8) is provided at the upper discharge end of the light-weight removal tower (4). A third cooler (9) is provided at the upper end of the heavy-weight removal tower (5). The product tank (6) is connected to the heavy-weight removal tower (5) through the third cooler (9).

2. The production apparatus for high-purity difluoroacetyl fluoride according to claim 1, characterized in that: A vaporizer (10) is provided between the raw material storage tank (1) and the cracking tower (2).

3. The production apparatus for high-purity difluoroacetyl fluoride according to claim 2, characterized in that: The buffer tank (3) is connected to a fourth cooler (11).

4. The production apparatus for high-purity difluoroacetyl fluoride according to claim 3, characterized in that: The fourth cooler (11) uses -60°C refrigerant for condensation, while the first cooler (7), the second cooler (8), and the third cooler (9) use -30°C refrigerant for condensation.

5. The production apparatus for high-purity difluoroacetyl fluoride according to claim 4, characterized in that: The outer wall of the buffer tank (3) is detachably provided with a heat insulation layer (16), and the buffer tank (3) is provided with a clamping assembly (17) for clamping the heat insulation layer (16).

6. The production apparatus for high-purity difluoroacetyl fluoride according to claim 5, characterized in that: The clamping assembly (17) includes an abutment plate (171), a first connecting strip (172) disposed on the abutment plate (171), and a second connecting strip (173) disposed on the abutment plate (171). The first connecting strip (172) and the second connecting strip (173) are connected to clamp the first connecting strip (172) and the second connecting strip (173) to the insulation layer (16).

7. The production apparatus for high-purity difluoroacetyl fluoride according to claim 6, characterized in that: The first connecting strip (172) has a connecting block (18) at one end away from the abutment plate (171), the second connecting strip (173) slides through the connecting block (18), and the connecting block (18) is provided with a positioning member (19) for positioning the second connecting strip (173) to restrict the second connecting strip (173) from sliding out of the connecting block (18).

8. The production apparatus for high-purity difluoroacetyl fluoride according to claim 7, characterized in that: The positioning element (19) includes a positioning rod (191) slidably connected to the connecting block (18) and an elastic element (192) disposed between the positioning rod (191) and the connecting block (18). The second connecting strip (173) has an abutment groove (20) on the side away from the insulation layer (16). The elastic element (192) can drive the positioning rod (191) to be inserted into the abutment groove (20).

9. The production apparatus for high-purity difluoroacetyl fluoride according to claim 8, characterized in that: An arc-shaped plate (21) is provided on the abutment plate (171), and an extension block (22) is provided on the arc-shaped plate (21). A bolt (23) is threaded through the extension block (22), and the bolt (23) is threaded to the side wall of the abutment plate (171).

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