Method for synthesizing carbonyl fluoride
By contacting and reacting with oxygen at specific temperatures and pressures, carbonyl fluoride is solved, and the problems of high corrosion resistance of equipment and high raw material costs in the prior art are achieved, low-cost and efficient carbonyl fluoride synthesis is suitable for semiconductor manufacturing and etching gases.
Patent Information
- Application Number
- CN202410041865.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-01-10
- Publication Date
- 2025-07-18
AI Technical Summary
Among the existing carbonyl fluoride production methods, the fluorine-gas fluorinated carbon monoxide method equipment has high corrosion and high cost, while the hexafluoropropylene oxide oxygen oxidation raw materials are expensive, making it difficult to achieve efficient and low-cost carbonyl fluoride synthesis.
The reaction of tetrafluoroethylene and oxygen at 50-250°C and 0-0.5MPa was used to react in contact with each other under conditions of 50-250°C and 0-0.5MPa to generate carbonyl fluoride. The reaction risk was controlled by preheating oxygen and adding polymerization inhibitors to achieve continuous synthesis.
The synthesis of carbonyl fluoride with low raw material prices, high yields and few impurities is achieved, which is suitable for the high purity needs of semiconductor manufacturing and etching gases.
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Figure CN120328522A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of synthesis of fluorine-containing fine chemicals, and in particular relates to a method for synthesizing carbonyl fluoride or fluorophosgene. Background Art
[0002] Carbonyl fluoride, also known as fluorophosgene, carbonyl fluoride, and carbonyl fluoride, is mainly used as a cleaning gas and etching gas for semiconductor manufacturing equipment. It is also an important intermediate and is mostly used in the synthesis of fluorinated olefin ethers. The semiconductor industry needs high-purity carbonyl fluoride.
[0003] The existing methods for producing carbonyl fluoride mainly include the fluorine gas fluorination carbon monoxide method and the hexafluoropropylene oxide oxygen oxidation method. The fluorine gas fluorination carbon monoxide method is often due to the fact that a certain amount of hydrogen fluoride is easily entrained during the preparation of fluorine gas, and the inherent corrosiveness of hydrogen fluoride leads to high investment costs for equipment and pipelines. The hexafluoropropylene oxide oxygen oxidation method has high raw material costs. Summary of the invention
[0004] In view of the above technical problems, the present invention provides a method for continuously synthesizing carbonyl fluoride with low raw material price and high conversion rate.
[0005] The invention provides a method for synthesizing carbonyl fluoride, comprising the following steps: tetrafluoroethylene and oxygen are contacted, the contact temperature is ≥50°C, and the contact pressure is ≤0.5MPa, so as to react and generate carbonyl fluoride.
[0006] Tetrafluoroethylene is an important fluorine-containing intermediate that has long had the capacity for large-scale production, while oxygen can be separated from the air through air separation units.
[0007] The chemical reaction equation for tetrafluoroethylene reacting with oxygen to generate carbonyl fluoride is:
[0008] C2F4+O2=2COF2
[0009] According to some embodiments of the method of the present invention, the contacting temperature is 50-250° C., and the contacting pressure is 0-0.5 MPa.
[0010] According to some embodiments of the method of the present invention, the molar ratio of tetrafluoroethylene to oxygen is 1:(0.5-5) (for example: 1:0.5, 1:1, 1:2, 1:3, 1:4, 1:5).
[0011] According to some embodiments of the method of the present invention, the molar ratio of tetrafluoroethylene to oxygen is 1:(0.8-1.5).
[0012] According to some embodiments of the method of the present invention, the tetrafluoroethylene is subjected to a pressure reduction treatment before contacting the tetrafluoroethylene with oxygen.
[0013] According to some embodiments of the method of the present invention, the pressure of tetrafluoroethylene is 0-0.5MPa. The lower the pressure of tetrafluoroethylene, the less likely it is to undergo a self-decomposition reaction. For this reaction, the reaction pressure has little effect on the reaction balance and reaction rate, and the purpose of controlling the reaction pressure is to control the reaction risk. The self-decomposition characteristics of tetrafluoroethylene, the coupling factors of pressure and temperature will cause the self-decomposition reaction of tetrafluoroethylene to occur, and this reaction is very likely to cause an explosion.
[0014] Due to the inherent characteristics of tetrafluoroethylene, dimerization and self-decomposition reactions of tetrafluoroethylene may occur. Before tetrafluoroethylene comes into contact with oxygen, the tetrafluoroethylene is reduced to a certain pressure to avoid dimerization and self-decomposition reactions of tetrafluoroethylene.
[0015] Dimerization reaction of tetrafluoroethylene: 2C2F4=C4F8+206kJ / mol
[0016] Self-decomposition reaction of tetrafluoroethylene: C2F4=C+CF4+257kJ / mol
[0017] Since the reaction of tetrafluoroethylene and oxygen to generate carbonyl fluoride is a highly exothermic reaction, effective temperature control is required during the reaction to remove the heat generated by the reaction. Therefore, the reaction materials are preferably preheated, preferably preheating oxygen to initiate the reaction. After the reaction is initiated, the heat released is sufficient to maintain the reaction temperature from dropping, and continuous heating is not required.
[0018] According to some embodiments of the method of the present invention, before the oxygen and tetrafluoroethylene come into contact, the temperature of the preheated oxygen is ≥ 50°C.
[0019] According to some embodiments of the method of the present invention, before the oxygen and tetrafluoroethylene come into contact, the temperature of the oxygen is preheated to 100-200°C, such as 100°C, 150°C, 180°C, 200°C.
[0020] According to some embodiments of the method of the present invention, before the tetrafluoroethylene and oxygen come into contact, a polymerization inhibitor may be added to the tetrafluoroethylene in advance.
[0021] According to some embodiments of the method of the present invention, the tetrafluoroethylene contains a polymerization inhibitor.
[0022] According to some embodiments of the method of the present invention, the concentration of the polymerization inhibitor in the tetrafluoroethylene is 50-200 ppm, 50 ppm, 80 ppm, 100 ppm, 150 ppm, 200 ppm.
[0023] According to some embodiments of the method of the present invention, the polymerization inhibitor is limonene.
[0024] Compared with the prior art, the beneficial effects of the present invention are as follows: The raw materials used in the synthesis method of the present invention are low in price, high in yield, can be set up for continuous reaction, and the reaction products have few impurities and do not affect the subsequent use of the products, etc. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figure 1 It is a flowchart of the synthesis method described in Example 1. DETAILED DESCRIPTION OF THE EMBODIMENTS
[0026] To make the objectives, technical solutions and advantages of the present invention more clear and understandable, the present invention will be further described in detail below in conjunction with the embodiments and the drawings. The specific embodiments described herein are only used to explain the present invention and do not constitute any limitation to the present invention. In addition, in the following description, the descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present disclosure. Such structures and technologies are also described in many publications.
[0027] Example 1
[0028] As Figure 1 shown, controlling the oxygen flow rate at 10 NL / h, after the oxygen is heated to 155 °C by a heater, tetrafluoroethylene is controlled at a pressure of 0.1 MPa by a pressure reducing valve and the flow rate is controlled at 10 NL / h. After being metered by a metering device respectively, to ensure that the molar ratio of tetrafluoroethylene to oxygen is 1:1, the tetrafluoroethylene is distributed by a distributor and then undergoes a combustion reaction with oxygen. Since the reaction is a strongly exothermic reaction, a refrigerant is introduced into the jacket during the reaction to control the reaction temperature at 150 °C and the reaction pressure at 0.05 MPa. After sampling and analysis, the product contains 98% COF2.
[0029] Example 2
[0030] The reaction device is the same as that in Example 1. The oxygen flow rate is 15 NL / h. After the oxygen is heated to 155 °C by a heater, tetrafluoroethylene is controlled at a pressure of 0.1 MPa by a pressure reducing valve. To avoid the dimerization of tetrafluoroethylene, 80 ppm of polymerization inhibitor (limonene) is added to the tetrafluoroethylene and the flow rate is controlled at 10 NL / h. After being metered by a metering device respectively, to ensure that the molar ratio of tetrafluoroethylene to oxygen is 2:3, the tetrafluoroethylene is distributed by a distributor and then undergoes a combustion reaction with oxygen. During the reaction, a refrigerant is introduced into the jacket to control the reaction temperature at 150 °C and the reaction pressure at 0.05 MPa. After sampling and analysis, the product contains 80% COF2, 11% oxygen, 4% CF4, and 4% CO2.
[0031] Example 3
[0032] The reaction device is the same as that in Example 1. The oxygen flow rate is controlled at 10 NL / h. After the oxygen is heated to 155 °C by a heater, tetrafluoroethylene is controlled at a pressure of 0.1 MPa by a pressure reducing valve. To avoid the dimerization of tetrafluoroethylene, 80 ppm of inhibitor (limonene) is added to tetrafluoroethylene and the flow rate is controlled at 10 NL / h. After being metered by a metering device respectively, the molar ratio of tetrafluoroethylene to oxygen is ensured to be 1:1. After being distributed by a distributor, tetrafluoroethylene reacts with oxygen by combustion. During the reaction process, a refrigerant is introduced into the jacket to control the reaction temperature at 250 °C and the reaction pressure at 0.05 MPa. Through sampling and analysis, the product contains 80% COF2, 10% CF4, and 10% CO2.
[0033] Comparative Example 1
[0034] The reaction device is the same as that in Example 1. The oxygen flow rate is controlled at 10 NL / h. After the oxygen is heated to 155 °C by a heater, tetrafluoroethylene is controlled at a pressure of 0.1 MPa by a pressure reducing valve. To avoid the dimerization of tetrafluoroethylene, 80 ppm of inhibitor (limonene) is added to tetrafluoroethylene and the flow rate is controlled at 10 NL / h. After being metered by a metering device respectively, the molar ratio of tetrafluoroethylene to oxygen is ensured to be 1:1. After being distributed by a distributor, tetrafluoroethylene reacts with oxygen by combustion. Since the reaction is a strongly exothermic reaction, a refrigerant is introduced into the jacket during the reaction process to control the reaction temperature at 300 °C. Through sampling and analysis, the product contains 20% COF2, 40% CF4, and 40% CO2.
[0035] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the technical concept scope of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.
Claims
1. A method for synthesizing carbonyl fluoride, comprising the following steps: Contact tetrafluoroethylene with oxygen at a temperature of the contact ≥ 50°C and a pressure of the contact ≤ 0.5 MPa, so as to react to produce carbonyl fluoride.
2. The method according to claim 1, wherein The temperature of the contact is 50 - 250°C, and the pressure of the contact is 0 - 0.5 MPa.
3. The method according to claim 1 or 2, characterized in that, The molar ratio of the tetrafluoroethylene to the oxygen is 1:(0.5 - 5).
4. The method according to claim 1 or 2, characterized in that, The molar ratio of the tetrafluoroethylene to the oxygen is 1:(0.8 - 1.5).
5. The method according to any one of claims 1-4, characterized in that, Before the tetrafluoroethylene and the oxygen are contacted, the pressure of the tetrafluoroethylene is reduced. Preferably, the pressure of the tetrafluoroethylene is 0 - 0.5 MPa.
6. The method according to any one of claims 1-5, characterized in that Before the oxygen and the tetrafluoroethylene are contacted, the temperature of the oxygen is preheated to ≥ 50°C.
7. The method according to any one of claims 1-5, characterized in that, Before the oxygen and the tetrafluoroethylene are contacted, the temperature of the oxygen is preheated to 100 - 200°C.
8. The method according to any one of claims 1-7, characterized in that, The tetrafluoroethylene contains an inhibitor.
9. The method according to claim 8, characterized in that, The concentration of the inhibitor in the tetrafluoroethylene is 50 - 200 ppm.
10. The method according to claim 8, wherein The inhibitor is limonene.