A reaction apparatus for producing carbonyl fluoride

Abstract

The utility model relates to fluorine chemical industry and electronic industry gas field mainly discloses a kind of reaction device of preparing carbonyl fluoride, including reactor cylinder, electric heater and high-temperature circulating fan, multiple efficient heat exchange tubes are arranged in reactor cylinder interior, the end of the end of reactor cylinder close to high-temperature gas import is sealedly installed with bottom cover, the end of bottom cover is provided with reaction gas import, the end of the end of reactor cylinder close to high-temperature gas export is sealedly installed with top cover, and the end of top cover is provided with reaction gas export.The reaction device of the utility model is removed in time by hot air circulation with excessive reaction heat, so that oxidation reaction is carried out in stable temperature range, effectively solve the problem that six fluorine propylene oxidation reaction efficiency is low and side reaction is many due to local reaction violent and heat exchange not in time in reactor.

Description

Technical Field

[0001] This utility model relates to the fields of fluorochemicals and electronic industrial gases, and more specifically, to a reaction apparatus for preparing carbonyl fluoride. Background Technology

[0002] Carbonyl fluoride (COF2) is an irritating, non-flammable, colorless, and toxic gas at room temperature. As an etching and cleaning gas in chemical vapor deposition (CVD) chambers in next-generation semiconductor manufacturing, COF2 has extremely low global warming potential (GWP≈1) compared to traditional perfluorinated carbon (PFC, GWP = 7390~12200) and nitrogen trifluoride (NF3, GWP = 17200), making it an environmentally friendly electronic gas with broad development potential.

[0003] The preparation of carbonyl fluoride can be classified into the following methods according to different raw materials: phosgene fluorination, carbon monoxide fluorination, photo-oxidation of difluoromonochlorofluoride, trifluoromethane oxidation, perfluoroalkyl iodide oxidation, tetrafluoroethylene oxidation, hexafluoropropylene oxidation, and hexafluoropropylene oxide oxidation. Currently, there are many reports on apparatus for synthesizing carbonyl fluoride from carbon monoxide, and apparatus for other raw materials have also been reported, while reports on apparatus for synthesizing carbonyl fluoride via hexafluoropropylene oxidation are relatively few.

[0004] Chinese patent CN102260160 reports the preparation of carbonyl fluoride from oxygen and hexafluoropropylene gas under catalytic conditions, wherein the catalyst is silver oxide, silver oxide supported on activated carbon, or silver oxide supported on alumina. The reaction apparatus is a fixed-bed, fluidized-bed, or moving-bed reactor, and the reactor material is stainless steel, nickel, or a nickel-based alloy. However, this method yields a near 1:1 mixture of carbonyl fluoride and trifluoroacetyl fluoride, along with other byproducts.

[0005] In fact, trifluoroacetyl fluoride can be further oxidized to produce two molecules of carbonyl fluoride. Chinese patent CN109607507 reports the preparation of carbonyl fluoride from oxygen and hexafluoropropylene gas under catalytic conditions, wherein the catalyst is silver oxide supported on alumina, and the reaction apparatus is a tube furnace. Under catalytic-free conditions, the ratio of carbonyl fluoride to trifluoroacetyl fluoride is 95:5, while under catalytic conditions, the ratio is 85:15.

[0006] The aforementioned reaction apparatuses all suffer from low oxidation efficiency of hexafluoropropylene and numerous side reactions, due to intense localized reactions and untimely heat exchange within the reactor. To achieve high yields of carbonyl fluoride, the reaction needs to proceed within a stable temperature range; therefore, precise temperature control of the reaction apparatus is crucial.

[0007] No effective solutions have yet been proposed to address the problems in the relevant technologies. Utility Model Content

[0008] The purpose of this invention is to provide a reaction apparatus for preparing carbonyl fluoride, so as to solve the problems mentioned in the background art.

[0009] To achieve the above objectives, this utility model provides the following technical solution: A reaction apparatus for preparing fluorinated carbonyl fluoride includes a reactor shell, an electric heater, and a high-temperature circulating fan. The outer wall of the reactor shell has a high-temperature gas inlet and a high-temperature gas outlet. The high-temperature gas inlet is connected to the outlet of the high-temperature circulating fan via a pipe. The inlet of the high-temperature circulating fan is connected to an outlet of the electric heater via a pipe. The inlet of the electric heater is connected to the high-temperature gas outlet via a pipe. Multiple high-efficiency heat exchange tubes are arranged inside the reactor shell. A bottom cover is sealed at the end of the reactor shell near the high-temperature gas inlet, and a reaction gas inlet is located at the end of the bottom cover. A top cover is sealed at the end of the reactor shell near the high-temperature gas outlet, and a reaction gas outlet is located at the end of the top cover.

[0010] Furthermore, temperature-sensing air regulating valves are installed on the pipes between the high-temperature gas inlet and the high-temperature circulating fan, as well as on the pipes between the high-temperature gas outlet and the electric heater.

[0011] Furthermore, tube sheets are fixedly installed inside the reactor shell near both ends, and the two ends of the high-efficiency heat exchange tubes are respectively installed through the tube sheets at both ends inside the reactor shell.

[0012] Furthermore, a grid plate for uniformly distributing circulating hot air is fixedly installed inside the reactor cylinder.

[0013] Furthermore, the high-efficiency heat exchange tube is made of nickel, and the grid plate, tube sheet, and reactor shell are all made of the same material, which is stainless steel.

[0014] Furthermore, the high-efficiency heat exchange tubes are parallel to the longitudinal axis of the reactor body, and multiple high-efficiency heat exchange tubes are arranged in an equilateral triangle.

[0015] Furthermore, the reactor shell is equipped with multiple reaction temperature measurement points.

[0016] Compared with the prior art, the present invention has the following advantages: The reaction device of the present invention removes excess reaction heat in time through hot air circulation, so that the oxidation reaction is carried out within a stable temperature range. This effectively solves the problems of low efficiency and many side reactions in the oxidation reaction of hexafluoropropylene caused by violent local reactions and untimely heat exchange in the reactor. It can also make the reaction fully oxidized, with fewer side reactions and a carbonyl fluoride purity of over 99%. The circulating hot air cooling results in a small temperature difference and a more stable reaction. The reaction heat exchange tubes adopt high-efficiency tubes, which have better heat exchange effect than ordinary tubular structures. Each pipeline reactor can be arranged simultaneously without the need for intermediate insulation and heating devices. The same production capacity device occupies less space, and the diameter of the pipeline reactor is small, which is more conducive to the uniform mixing of the reaction mixture in the reactor. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of a reaction apparatus for preparing carbonyl fluoride according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the reactor cylinder structure in a reaction apparatus for preparing carbonyl fluoride according to an embodiment of the present invention; Figure 3 This is a schematic diagram of a high-efficiency heat exchange tube structure in a reaction apparatus for preparing carbonyl fluoride according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the grid structure in a reaction apparatus for preparing carbonyl fluoride according to an embodiment of the present invention.

[0019] Figure label: 1. Reactor shell; 101. High-temperature gas inlet; 102. High-temperature gas outlet; 2. Electric heater; 3. High-temperature circulating fan; 4. High-efficiency heat exchange tube; 5. Bottom cover; 51. Reaction gas inlet; 6. Top cover; 61. Reaction gas outlet; 7. Temperature-sensing air regulating valve; 8. Grid plate; 9. Tube sheet; 10. Reaction temperature measuring point. Detailed Implementation

[0020] The utility model will now be further described with reference to the accompanying drawings and specific embodiments: Please see Figures 1-4According to an embodiment of the present invention, a reaction apparatus for preparing carbonyl fluoride includes a reactor body 1, an electric heater 2, and a high-temperature circulating fan 3. A high-temperature gas inlet 101 and a high-temperature gas outlet 102 are provided on the outer wall of the reactor body 1. The high-temperature gas inlet 101 is connected to the outlet of the high-temperature circulating fan 3 via a pipe. The inlet of the high-temperature circulating fan 3 is connected to an outlet of the electric heater 2 via a pipe. The inlet of the electric heater 2 is connected to the high-temperature gas outlet 102 via a pipe. Multiple high-efficiency heat exchange tubes 4 are arranged inside the reactor body 1. The number of high-efficiency heat exchange tubes 4 can be adjusted according to the required production capacity. A bottom cover 5 is sealed and installed at one end of the reactor body 1 near the high-temperature gas inlet 101. A reaction gas inlet 51 is provided at the end of the bottom cover 5. A top cover 6 is sealed and installed at one end of the reactor body 1 near the high-temperature gas outlet 102. A reaction gas outlet 61 is provided at the end of the top cover 6.

[0021] The reaction gas enters the reactor shell 1 through the reaction gas inlet 51 at atmospheric pressure and is evenly distributed into the high-efficiency heat exchange tube 4. Finally, it is discharged from the reaction gas outlet 61. During this process, the electric heater 2 and the high-temperature circulating fan 3 are kept on to ensure the supply of circulating hot air inside the reactor shell 1.

[0022] Temperature-sensing air regulating valves 7 are installed on the pipe between the high-temperature gas inlet 101 and the high-temperature circulating fan 3, and on the pipe between the high-temperature gas outlet 102 and the electric heater 2. When the internal temperature of the reactor body 1 exceeds the set temperature, the temperature-sensing air regulating valve 7 opens, and cold air enters the air path for cooling. When the temperature is lower than the set temperature, the temperature-sensing air regulating valve 7 closes, and the system maintains the temperature to the set temperature.

[0023] Tube sheets 9 are fixedly installed inside the reactor body 1 near both ends. The two ends of the high-efficiency heat exchange tube 4 are respectively installed through the tube sheets 9 at both ends inside the reactor body 1. The tube sheets 9 can stably assemble the high-efficiency heat exchange tube 4.

[0024] A grid plate 8 is also fixedly installed inside the reactor cylinder 1, which can uniformly distribute the circulating hot air inside the reactor cylinder 1.

[0025] The high-efficiency heat exchange tube 4 is made of nickel, and the grid plate 8 is made of the same material as the tube sheet 9 and the reactor shell 1, which is stainless steel.

[0026] The high-efficiency heat exchange tube 4 is parallel to the longitudinal axis of the reactor body 1. Multiple high-efficiency heat exchange tubes 4 are arranged in an equilateral triangle. The diameter of the high-efficiency heat exchange tube 4 is Φ32~57. The number of high-efficiency heat exchange tubes 4 can reach 300. The center-to-center distance of each high-efficiency heat exchange tube is 55~100 mm.

[0027] The reactor shell 1 is equipped with multiple reaction temperature measuring points 10. The reaction temperature measuring points 10 can perform point-to-point temperature measurement in various areas inside the reactor shell 1.

[0028] The electric heater 2 can reach a heating temperature of 500℃.

[0029] The heating medium for the reaction apparatus is air, and a circulating hot air cooling method is adopted.

[0030] When using this reaction apparatus for production, first turn on the electric heater 2 and set the temperature to 400℃. Then turn on the high-temperature circulating fan 3 to premix oxygen and hexafluoropropylene at a molar ratio of 1:2. The mixed gas enters from the reaction gas inlet 51 and passes uniformly through the high-efficiency heat exchange tube 4 at a certain speed. After being heated to 400℃ in the high-efficiency heat exchange tube 4, the reaction can be initiated. The reaction heat is used to maintain the continuous reaction. Finally, the gas merges in the top cover 6 and is discharged from the reactor through the reaction gas outlet 61. The reaction temperature is controlled between 400 and 450℃ throughout the process. When the temperature is greater than 450℃, the temperature-sensing air regulating valve 7 opens, cold air enters, and the system begins to cool down, removing the reaction heat in time. When the temperature is less than 400℃, the temperature-sensing air regulating valve 7 closes, and the apparatus begins to maintain the temperature required for the reaction to start. After the gas is cooled, it is passed into anhydrous methanol. GC results show that the product has a carbonyl fluoride content of 99.3% and a trifluoroacetyl fluoride content of 0.7%.

[0031] Through the above-described solution of this utility model, the reaction device of this utility model removes excess reaction heat in a timely manner through hot air circulation, so that the oxidation reaction can be carried out within a stable temperature range. This effectively solves the problems of low efficiency and many side reactions in the oxidation reaction of hexafluoropropylene caused by intense local reactions and untimely heat exchange in the reactor. It can make the reaction fully oxidized, with fewer side reactions and a carbonyl fluoride purity of over 99%. The use of circulating hot air cooling results in a small temperature difference and a more stable reaction. Furthermore, the high-efficiency heat exchange tube 4 adopts a high-efficiency tube array, which has a better heat exchange effect than the ordinary tubular structure. Each pipeline reactor can be arranged simultaneously without the need for intermediate insulation and heating devices. The same production capacity device occupies less space, and the small diameter of the pipeline reactor is more conducive to the uniform mixing of the reaction mixture in the reactor.

[0032] In this utility model, unless otherwise explicitly specified and limited, the terms "installation", "setting", "connection", "fixing", "screw connection", etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0033] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0034] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

[0035] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A reaction apparatus for preparing carbonyl fluoride, characterized in that, The reactor includes a reactor body (1), an electric heater (2), and a high-temperature circulating fan (3). The outer wall of the reactor body (1) is provided with a high-temperature gas inlet (101) and a high-temperature gas outlet (102). The high-temperature gas inlet (101) is connected to the outlet of the high-temperature circulating fan (3) through a pipe. The inlet of the high-temperature circulating fan (3) is connected to an outlet of the electric heater (2) through a pipe. The inlet of the electric heater (2) is connected to the high-temperature gas outlet (102) through a pipe. Multiple high-efficiency heat exchange tubes (4) are arranged inside the reactor body (1). A bottom cover (5) is sealed at one end of the reactor body (1) near the high-temperature gas inlet (101). A reaction gas inlet (51) is provided at the end of the bottom cover (5). A top cover (6) is sealed at one end of the reactor body (1) near the high-temperature gas outlet (102). A reaction gas outlet (61) is provided at the end of the top cover (6).

2. The reaction apparatus for preparing carbonyl fluoride according to claim 1, characterized in that, Temperature-sensing air regulating valves (7) are installed on the pipe between the high-temperature gas inlet (101) and the high-temperature circulating fan (3) and on the pipe between the high-temperature gas outlet (102) and the electric heater (2).

3. The reaction apparatus for preparing carbonyl fluoride according to claim 2, characterized in that, Tube sheets (9) are fixedly installed inside the reactor cylinder (1) near both ends, and the two ends of the high-efficiency heat exchange tubes (4) are respectively installed through the tube sheets (9) at both ends inside the reactor cylinder (1).

4. The reaction apparatus for preparing carbonyl fluoride according to claim 3, characterized in that, The reactor cylinder (1) is also fixedly installed with a grid plate (8) that evenly distributes circulating hot air.

5. The reaction apparatus for preparing carbonyl fluoride according to claim 4, characterized in that, The high-efficiency heat exchange tube (4) is made of nickel tube, and the grid plate (8) is made of the same material as the tube sheet (9) and the reactor shell (1), all of which are stainless steel.

6. The reaction apparatus for preparing fluorocarbonyl fluoride according to claim 5, characterized in that, The high-efficiency heat exchange tube (4) is parallel to the longitudinal axis of the reactor body (1), and multiple high-efficiency heat exchange tubes (4) are arranged in an equilateral triangle.

7. The reaction apparatus for preparing carbonyl fluoride according to claim 6, characterized in that, The reactor cylinder (1) is equipped with multiple reaction temperature measuring points (10).

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