Diiodo perfluorobutane production system

Abstract

The utility model discloses a diiodo perfluorobutane production system, which belongs to the technical field of chemical production systems and comprises a diiodo perfluoroethane raw material storage tank, a sectional tubular reactor, a high-low temperature circulating tank, a product storage tank and a pipeline. The diiodo perfluoroethane raw material storage tank is connected to an inlet of the sectional tubular reactor through a pipeline; the sectional type tubular reactor comprises a shell and a reaction tube, a cavity between the shell and the reaction tube is used for being filled with a heating medium, the sectional type tubular reactor is divided into a tubular reactor section I and a tubular reactor section II by at least two partition plates in the sectional type tubular reactor, and a vacuum environment is formed between the partition plates to prevent heat transfer; the high-low temperature circulating tank is used for respectively controlling the temperature of the tubular reactor I section and the tubular reactor II section; and the outlet of the sectional tubular reactor is connected with a product storage tank through a pipeline. The reaction device is optimized, so that the heat transfer efficiency is improved, the backmixing amount in the temperature rise process is reduced, and the conversion rate of raw materials and the selectivity of target products are improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of chemical production systems, and in particular relates to a diiodoperfluorobutane production system. Background Art

[0002] The CI bond in diiodoperfluorobutane is extremely unstable and easily breaks, leading to free radical addition, telomerization, and polymerization reactions. It is widely used in the synthesis of long-chain and branched per- or polyfluorinated compounds and serves as a very important fluorinated intermediate. The fluorinated epoxides, fluorinated diacetylenes, and branched fluorinated diols obtained through these reactions can be copolymerized with other compounds to produce fluorinated polymers such as fluorinated polyesters, fluorinated polyepoxy resins, and fluorinated polyacrylates. Furthermore, the diiodoperfluoroalkane diethylene addition products obtained by the addition of diiodoperfluorobutane to ethylene can be used to synthesize various fluorinated compounds by converting the iodine at both ends into other functional groups. These compounds are used in the fabrication of metals, glass, and polytetrafluoroethylene materials, thus possessing broad application prospects.

[0003] In the prior art, diiodoperfluoroalkanes are generally produced by the polymerization reaction of 1,2-diiodoperfluoroethane and tetrafluoroethylene. However, the corresponding polymerization process requires the addition of a large amount of excessive tetrafluoroethylene gas, resulting in high reaction pressure, long reaction time, and a highly exothermic reaction, which poses a high risk. In addition, during the closed system reaction process, a portion of the tetrafluoroethylene gas will dimerize to form octafluorocyclobutane, resulting in a decrease in reaction rate or even termination of the reaction.

[0004] The preparation of diiodoperfluorobutane by deiodination polymerization of 1,2-diiodoperfluoroethane is a feasible strategy. However, the use of conventional kettle reactors will produce a large amount of elemental iodine accumulation, which can easily cause equipment blockage. Moreover, as the reaction time increases, side reactions increase, resulting in reduced reaction selectivity and yield.

[0005] Chinese patent document CN221016078U discloses a synthesis reaction device for fluorine-containing compounds. Its structure includes an adsorption chamber, a main body, a reflux pipe, and a gas collection hood. The gas collection hood is set on the top of the main body, the gas collection hood is connected to the reflux pipe, the reflux pipe is connected to the adsorption chamber, and the adsorption chamber is connected to the main body. The utility model uses a fluidized bed method for processing, which can quickly mix the reactants and effectively increase the reaction rate.

[0006] Chinese patent publication CN206858471U discloses a continuous synthesis apparatus for aromatic fluorine-containing compounds, comprising a fluorination reaction tower with a chloride inlet at its upper portion connected to a chloride storage tank; a hydrogen fluoride inlet at least at its lower portion; an exhaust gas outlet at its top; a condenser, an acid mist collector, and a mixer connected in sequence; the mixer outlet connected to the chloride inlet; and a chloride storage tank. This production apparatus not only enables continuous production, but also achieves high raw material utilization and product purity.

[0007] However, the above equipment is not suitable for the production of diiodiperfluorobutane, and the reaction temperature of using 1,2-diiodiperfluoroethane for deiodination polymerization to prepare diiodiperfluorobutane is too high, and the reaction process is difficult to control. Therefore, it is necessary to develop a diiodiperfluorobutane production system. Utility Model Content

[0008] The utility model provides a diiodoperfluorobutane production system, which improves heat transfer efficiency and reduces the amount of backmixing during the temperature rise process through the arrangement of a segmented tubular reactor and the coordination between the reactor and other components, thereby reducing side reactions and the generation of high-boiling by-products and improving the conversion rate of raw materials and the selectivity of target products.

[0009] The specific technical solutions adopted are as follows:

[0010] A diiodoperfluorobutane production system comprises: a diiodoperfluoroethane raw material storage tank, a segmented tubular reactor, a high and low temperature circulation tank, a product storage tank and a pipeline;

[0011] The diiodiperifluoroethane raw material storage tank is connected to the inlet of the segmented tubular reactor through a pipeline; the segmented tubular reactor includes a shell and a reaction tube, the cavity between the shell and the reaction tube is used to fill a heating medium, and the segmented tubular reactor is divided into a tubular reactor section I and a tubular reactor section II by at least two partitions inside the segmented tubular reactor. The tubular reactor section I is used to preheat the diiodiperifluoroethane, and the tubular reactor section II is used to carry out a continuous cracking reaction of the preheated diiodiperifluoroethane. A vacuum environment is provided between the partitions to prevent heat transfer; a high and low temperature circulation tank is used to respectively control the temperature of the tubular reactor section I and the tubular reactor section II; and the outlet of the segmented tubular reactor is connected to a product storage tank through a pipeline.

[0012] Optionally, the diiodoperfluorobutane production system further includes a vacuum system and an inert gas system. The vacuum system is used to evacuate the pipelines and reaction tubes, and the inert gas system is used to fill the pipelines and reaction tubes with inert gas.

[0013] Preferably, the inert gas is nitrogen.

[0014] Furthermore, a feed pump is provided on the connecting pipeline between the diiodoperfluoroethane raw material storage tank and the segmented tubular reactor.

[0015] Preferably, the length-to-diameter ratio of the reaction tube in the segmented tubular reactor is 50 to 80:1, and the material can be Hastelloy C-276.

[0016] Further preferably, the aspect ratio of the reaction tube in section I of the tubular reactor is 50 to 60:1, and the aspect ratio of the reaction tube in section II of the tubular reactor is 65 to 75:1, wherein the diameters of the reaction tubes in section I of the tubular reactor and section II of the tubular reactor are the same, and the aspect ratio of the reaction tube in section II of the tubular reactor is larger, which can extend the reaction residence time and help the reaction to proceed fully.

[0017] Optionally, the heating medium is conductive oil.

[0018] Preferably, the high and low temperature circulation tank controls the temperature of tubular reactor section I and tubular reactor section II through a circulation pump and a heating medium circulation pipeline; the preheating temperature of tubular reactor section I is 80-110°C; the cracking temperature of tubular reactor section II is 180-240°C.

[0019] Preferably, the product storage tank is a pressure-resistant storage tank made of 316L stainless steel with a pressure rating of 3.5 to 5.0 MPa.

[0020] Preferably, the product storage tank is placed in a refrigerant, and the refrigerant is further preferably circulating water.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] (1) The utility model optimizes the reaction device and adopts a segmented tubular reactor to improve the heat transfer efficiency and reduce the amount of backmixing during the temperature rise process, thereby reducing side reactions and the generation of high-boiling by-products, and improving the conversion rate of raw materials and the selectivity of target products.

[0023] (2) The system of the utility model is used to prepare diiodoperfluorobutane. The reaction conditions are mild and easy to control, which can achieve continuous production and controllable product quality. In addition, the iodine product during the reaction is collected in a pressure-resistant storage tank in the form of gas or liquid, and the reaction tube is not easily blocked during the reaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic structural diagram of the diiodoperfluorobutane production system of the present invention.

[0025] Figure numerals: 1 diiodoperfluoroethane raw material storage tank, 2 feed pump, 3 tubular reactor section I, 4 partition, 5 tubular reactor section II, 6 product storage tank, 7 refrigerant, 8 first high and low temperature circulation tank, 9 first circulation pump, 10 second circulation pump, 11 second high and low temperature circulation tank, 12 pipeline. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0027] like Figure 1 As shown, the diiodoperfluorobutane production system includes: a diiodoperfluoroethane raw material storage tank 1, a segmented tubular reactor, a high and low temperature circulation tank, a product storage tank 6, a pipeline 12, a vacuum system and an inert gas system;

[0028] The diiodoperfluoroethane raw material storage tank 1 is connected to the inlet of the segmented tubular reactor through a pipeline 12; the segmented tubular reactor includes a shell and a reaction tube, and the cavity between the shell and the reaction tube is used to fill the heating medium conductive oil. The segmented tubular reactor is divided into a tubular reactor section I 3 and a tubular reactor section II 5 by at least two partitions 4 inside it. The tubular reactor section I 3 is used to preheat the diiodoperfluoroethane, and the tubular reactor section II 5 is used to carry out a continuous cracking reaction of the preheated diiodoperfluoroethane. The vacuum environment is between the partitions 4 to prevent heat transfer; the high and low temperature circulation tank is used to control the temperature of the tubular reactor section I 3 and the tubular reactor section II 5 respectively; the outlet of the segmented tubular reactor is connected to a product storage tank 6 through a pipeline; the vacuum system is used to evacuate the pipeline and the reaction tube, and the inert gas system is used to fill the pipeline and the reaction tube with inert gas (not shown in the figure).

[0029] Furthermore, a feed pump 2 is provided on the connecting pipeline between the diiodoperfluoroethane raw material storage tank 1 and the segmented tubular reactor.

[0030] Furthermore, the length-to-diameter ratio of the reaction tube in the tubular reactor section I 3 is 50-60:1, and the length-to-diameter ratio of the reaction tube in the tubular reactor section II 5 is 65-75:1.

[0031] Furthermore, the second high and low temperature circulation tank 11 controls the temperature of the tubular reactor section I 3 through the second circulation pump 10 and the heating medium circulation pipeline, and the first high and low temperature circulation tank 8 controls the temperature of the tubular reactor section II 5 through the first circulation pump 9 and the heating medium circulation pipeline.

[0032] Furthermore, the product storage tank 6 is a pressure-resistant tank made of stainless steel 316L with a pressure resistance level of 3.5 to 5.0 MPa; the product storage tank 6 is arranged in the refrigerant 7, and the refrigerant is circulating water.

[0033] The working principle of the diiodoperfluorobutane production system is as follows: using diiodoperfluoroethane as raw material, a continuous cracking reaction is carried out in a tubular reactor. The main products of the reaction are diiodoperfluorobutane and elemental iodine, and the by-products are diiodoperfluorohexane, diiodoperfluorooctane and other products. Specifically, open the vacuum system, evacuate to -40kPa ~ -50kPa, then open the inert gas system and use high-purity nitrogen to purge the pipeline and reaction tube, replace it 3 times, and then use the second high and low temperature circulation tank to control the preheating temperature of the tubular reactor section I to 80 ~ 110 ° C. The diiodoperfluoroethane in the diiodoperfluoroethane raw material storage tank enters the tubular reactor section I for preheating through the feed pump. The feed flow rate of diiodoperfluoroethane is 10 ~ 20L / h. The first high and low temperature circulation tank is used to control the preheating temperature of the tubular reactor section I to 80 ~ 110 ° C. The cracking reaction temperature of the tubular reactor section II is 180-240°C. The preheated raw materials undergo cracking reaction in the tubular reactor section II to generate gaseous diiodoperfluorobutane and gaseous elemental iodine. If the cracking reaction temperature is too high, the reaction process is difficult to control and more high-boiling by-products will be generated, reducing the selectivity and product yield. If the cracking reaction temperature is too low, the iodine cannot be vaporized, which easily blocks the reactor pipeline and the reaction rate is slow. Finally, the gaseous product is liquefied in the pipeline and collected in the product storage tank for insulation and subsequent processing.

[0034] Specifically, the feed rate of the raw material diiodoperfluoroethane, the preheating temperature, and the cracking temperature were changed, and the conversion rate of diiodoperfluoroethane and the yield of the target product diiodoperfluorobutane were calculated. The results are shown in Table 1.

[0035] Table 1 Statistical results under different conditions

[0036]

[0037] The embodiments described above provide a detailed description of the technical solutions of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, supplements or similar substitutions made within the scope of the principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A diiodoperfluorobutane production system, characterized in that: include: Diiodoperfluoroethane raw material storage tank, segmented tubular reactor, high and low temperature circulation tank, product storage tank and pipeline; The diiodiperifluoroethane raw material storage tank is connected to the inlet of the segmented tubular reactor through a pipeline; the segmented tubular reactor includes a shell and a reaction tube, the cavity between the shell and the reaction tube is used to fill the heating medium, and the segmented tubular reactor is divided into tubular reactor section I and tubular reactor section II by at least two partitions inside it. The tubular reactor section I is used to preheat the diiodiperifluoroethane, and the tubular reactor section II is used to carry out continuous cracking reaction of the preheated diiodiperifluoroethane, and a vacuum environment is created between the partitions; a high and low temperature circulation tank is used to respectively control the temperature of the tubular reactor section I and the tubular reactor section II; the outlet of the segmented tubular reactor is connected to a product storage tank through a pipeline.

2. The diiodoperfluorobutane production system according to claim 1, characterized in that: The diiodoperfluorobutane production system further comprises a vacuum system and an inert gas system. The vacuum system is used to evacuate the pipeline and the reaction tube, and the inert gas system is used to fill the pipeline and the reaction tube with inert gas.

3. The diiodoperfluorobutane production system according to claim 1, characterized in that: A feed pump is also provided on the connecting pipeline between the diiodoperfluoroethane raw material storage tank and the segmented tubular reactor.

4. The diiodoperfluorobutane production system according to claim 1, characterized in that: The length-to-diameter ratio of the reaction tube in the segmented tubular reactor is 50 to 80:1, and the material used is Hastelloy C-276.

5. The diiodoperfluorobutane production system according to claim 1, characterized in that: The length-to-diameter ratio of the reaction tube in section I of the tubular reactor is 50-60:1, and the length-to-diameter ratio of the reaction tube in section II of the tubular reactor is 65-75:

1.

6. The diiodoperfluorobutane production system according to claim 1, characterized in that: The heating medium is conductive oil.

7. The diiodoperfluorobutane production system according to claim 1, characterized in that: The high and low temperature circulation tank controls the temperature of tubular reactor section I and tubular reactor section II respectively through the circulation pump and the heating medium circulation pipeline. The preheating temperature of tubular reactor section I is 80-110°C, and the cracking temperature of tubular reactor section II is 180-240°C.

8. The diiodoperfluorobutane production system according to claim 1, characterized in that: The product storage tank is a pressure-resistant tank made of 316L stainless steel with a pressure rating of 3.5 to 5.0 MPa.

9. The diiodoperfluorobutane production system according to claim 1, characterized in that: The product storage tank is arranged in a refrigerant, and the refrigerant is circulating water.

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