A continuous production system of hexafluoropropylene oxide

Abstract

The utility model belongs to hexafluoro propylene oxide preparation technical field, concretely is a kind of hexafluoro propylene oxide continuous production system, including reaction unit, feed unit, oxygen supply unit, heat energy circulation unit and product separation unit, reaction unit includes multiple in series connection's tubular reactor;Feed unit includes the main feed line connected with first tubular reactor;Oxygen supply unit includes multiple parallel oxygen branch pipes, and oxygen branch pipe and tubular reactor one-to-one correspondence;Heat energy circulation unit includes heat conducting oil circulation pipeline, heat conducting oil circulation pipeline is sequentially penetrated all tubular reactor, and heat conducting oil pump and first heat exchanger are sequentially arranged in the downstream of heat conducting oil receiving groove along the flow direction of heat conducting oil;Product separation unit includes the gas-liquid separator communicated with the discharge end of last tubular reactor. The application realizes the safety, high efficiency and low energy consumption of reaction process by the series connection layout of tubular reactor, multistage distributed oxygen feed and the use of heat energy circulation.

Description

Technical Field

[0001] This invention belongs to the field of hexafluoropropylene oxide preparation technology, specifically a continuous production system for hexafluoropropylene oxide. Background Technology

[0002] Hexafluoropropylene oxide (HFPO), with the molecular formula C3F6O, is a colorless, non-flammable gas with a slight odor at room temperature and pressure. It is an important intermediate in fine fluorinated chemicals. Due to its special properties, hexafluoropropylene oxide and its downstream products are mainly used in the preparation of inhaled anesthetics, fluororubber, fluoroplastics, perfluorinated ion exchange resins, fluorinated lubricants, and fluorinated surfactants, finding wide application in the pharmaceutical, healthcare, and chemical materials industries. In recent years, with the rapid development of emerging fields such as new energy, semiconductors, and the "dual-carbon" strategy, the demand for hexafluoropropylene oxide and its high-value-added downstream products has been increasing, leading to continuously rising requirements for its production efficiency and safety.

[0003] Currently, the mainstream industrial route for preparing hexafluoropropylene oxide is through the oxidation of hexafluoropropylene with oxygen. Existing production processes are mainly divided into two modes: batch reactor and continuous reactor. However, both have significant drawbacks: the batch reactor process involves adding hexafluoropropylene and oxygen into a reactor containing solvent all at once, reacting at specific temperatures and pressures. Each reaction cycle requires lengthy heating and cooling phases, resulting in high energy consumption, long cycles, and low production efficiency, making it difficult to meet the demands of large-scale continuous production. Furthermore, the gas phase space above the reactor is prone to localized accumulation of hexafluoropropylene and oxygen, posing a high risk of explosion and poor safety. While the continuous reactor process uses a fully mixed-flow reactor for continuous operation, achieving continuous material input and output, the hexafluoropropylene and oxygen are introduced into the reactor as premixed gases, making it highly susceptible to reaching the explosion limit within the entire reaction system, thus the inherent safety is not fundamentally improved. Utility Model Content

[0004] To address the problems mentioned above, this invention provides a continuous production system for hexafluoropropylene oxide. This system achieves a safe, efficient, and low-energy-consumption reaction process through the series layout of tubular reactors, multi-stage distributed oxygen feeding, and the utilization of thermal energy circulation.

[0005] The technical solution of this utility model is as follows:

[0006] A continuous production system for hexafluoropropylene oxide includes:

[0007] The reaction unit comprises at least two tubular reactors connected in series.

[0008] The feeding unit includes a main feed line connected to the first tubular reactor, and a hexafluoropropylene receiving tank is connected to the main feed line via a feed pump.

[0009] The oxygen supply unit includes multiple parallel oxygen branch pipes, and the outlet of each oxygen branch pipe is connected to the feed end of a tubular reactor.

[0010] The thermal energy circulation unit includes a heat transfer oil circulation pipeline, a heat transfer oil receiving tank installed on the heat transfer oil circulation pipeline, a heat transfer oil pump, and a first heat exchanger. The heat transfer oil circulation pipeline passes through all the tubular reactors in sequence, and the heat transfer oil pump and the first heat exchanger are installed downstream of the heat transfer oil receiving tank in sequence along the flow direction of the heat transfer oil.

[0011] The product separation unit includes a gas-liquid separator connected to the discharge end of the last tubular reactor.

[0012] Furthermore, the thermal energy circulation unit also includes a second heat exchanger installed on the main feed pipeline. After the heat transfer oil circulation pipeline flows through all the tubular reactors, it enters the second heat exchanger and returns to the heat transfer oil receiving tank after passing through the second heat exchanger.

[0013] Furthermore, the heat transfer oil circulation pipeline includes:

[0014] The main pipeline connects to the outlet of the heat transfer oil receiving tank and the inlet of the first heat exchanger at its two ends, respectively.

[0015] The first branch line connects the outlet of the first heat exchanger and the inlet of the first tubular reactor. The first valve is installed on the first branch line.

[0016] The second branch road has one end connected to the main road and the other end connected to the first branch road. A second valve is installed on the second branch road.

[0017] The third branch is connected to the outlet of the first heat exchanger and the inlet of the heat transfer oil receiving tank at its two ends, respectively, and a third valve is installed on the third branch.

[0018] Furthermore, the first heat exchanger is configured to selectively connect to either a steam heat source or a circulating cooling water source.

[0019] Furthermore, the product separation unit also includes a solvent circulation pipeline. The inlet of the solvent circulation pipeline is connected to the bottom liquid phase outlet of the gas-liquid separator, and its outlet is connected to the main feed pipeline. A solvent circulation pump is installed on the solvent circulation pipeline.

[0020] Furthermore, the product separation unit also includes a third heat exchanger installed on the top gas phase outlet pipeline of the gas-liquid separator.

[0021] Furthermore, a mixer is installed inside the tubular reactor.

[0022] Furthermore, it also includes a back pressure valve located between the outlet of the last tubular reactor and the gas-liquid separator.

[0023] Furthermore, a flow meter is installed on the oxygen branch line.

[0024] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0025] (1) The continuous production system of hexafluoropropylene oxide of this utility model adopts tubular reactors arranged in series. Each tubular reactor has a small liquid holding capacity, which eliminates the large gas phase explosion space. At the same time, it adopts a multi-stage oxygen supply method. Each tubular reactor is equipped with an independent oxygen supply port, which avoids the premixing of hexafluoropropylene and oxygen before entering the tubular reactor, thus reducing the risk of explosion from the source.

[0026] (2) The continuous production system for hexafluoropropylene oxide of this utility model can achieve the preheating of the sample material before it enters the tubular reactor by setting up a thermal energy circulation unit. The heat transfer oil can maintain the stable reaction of the tubular reactor within the reaction temperature range, thereby improving production efficiency and significantly reducing energy consumption. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art 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.

[0028] Figure 1 This is an overall structural diagram of a continuous production system for hexafluoropropylene oxide provided in an embodiment of this application;

[0029] Figure 2 A schematic diagram of the heating and cooling processes of a continuous production system for hexafluoropropylene oxide provided in an embodiment of this application;

[0030] Figure 3 A schematic diagram of the temperature control process of a continuous production system for hexafluoropropylene oxide provided in an embodiment of this application;

[0031] Wherein: 1-Tube reactor, 2-Main feed pipeline, 3-Hexafluoropropylene receiving tank, 4-Feed pump, 5-Heat transfer oil receiving tank, 6-Heat transfer oil pump, 7-First heat exchanger, 8-Gas-liquid separator, 9-Second heat exchanger, 10-Main line, 11-First branch line, 12-Second branch line, 13-Third branch line, 14-First valve, 15-Second valve, 16-Third valve, 17-Solvent circulation pipeline, 18-Solvent circulation pump, 19-Third heat exchanger, 20-Back pressure valve. Detailed Implementation

[0032] The technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0033] The following is in conjunction with the appendix Figure 1 To be continued Figure 3 The present invention will be described in detail with specific embodiments.

[0034] See Figures 1 to 3This invention provides a continuous production system for hexafluoropropylene oxide, comprising a reaction unit, a feeding unit, an oxygen supply unit, a thermal energy circulation unit, and a product separation unit. The reaction unit includes at least two tubular reactors 1 connected in series, such as two tubular reactors, three tubular reactors, ..., N tubular reactors. Each tubular reactor 1 is equipped with a mixer to enhance material mixing and mass transfer. The feeding unit includes a main feed pipeline 2 connected to the first tubular reactor 1. A hexafluoropropylene receiving tank 3 is connected to the main feed pipeline 2 via a feed pump 4 to transport hexafluoropropylene into the tubular reactor 1. A solvent is also introduced into the main feed pipeline 2, allowing the hexafluoropropylene and solvent to mix before entering the tubular reactor 1. The oxygen supply unit includes multiple parallel oxygen branch pipes (not shown in the figure), meaning each tubular reactor 1 corresponds to one oxygen branch pipe, and the outlet of each oxygen branch pipe is connected to... At the feed end of a tubular reactor 1, each oxygen branch pipe is equipped with a flow meter. In other words, each tubular reactor 1 has an independent oxygen inlet. The oxygen supply at each inlet is variable, but the total oxygen supply is constant. The thermal energy circulation unit includes a heat transfer oil circulation pipeline, a heat transfer oil receiving tank 5 located on the heat transfer oil circulation pipeline, a heat transfer oil pump 6, and a first heat exchanger 7. The first heat exchanger 7 is configured to selectively connect to a steam heat source or a circulating cooling water source. The heat transfer oil in the heat transfer oil circulation pipeline flows through all tubular reactors 1 in sequence. The heat transfer oil pump 6 and the first heat exchanger 7 are located downstream of the heat transfer oil receiving tank 5 along the flow direction of the heat transfer oil. The heat transfer oil pump 6 is used to pump the heat transfer oil in the heat transfer oil receiving tank 5 for circulation, and the first heat exchanger 7 is used to heat or cool the heat transfer oil. The product separation unit includes a gas-liquid separator 8 connected to the discharge end of the last tubular reactor 1. The reaction products are separated in the gas-liquid separator 8.

[0035] This invention fundamentally changes the form and reaction process of existing reactors by employing at least two tubular reactors connected in series as reaction units. Designing the reaction unit as multiple tubular reactors 1 in series results in a significantly lower liquid holdup than traditional batch reactors, greatly reducing the amount of hazardous materials in the reaction system. Simultaneously, the multi-stage, distributed oxygen supply mode allows oxygen to be added to the reaction unit at different points and stages, completely avoiding the explosive premixing of hexafluoropropylene and oxygen before they enter the tubular reactor 1. Furthermore, the system is equipped with a thermal energy circulation unit, which not only maintains a stable reaction temperature but also allows heat to be recycled. In this continuous reaction process, only an initial energy supply is needed to initiate the reaction; the energy consumption required for production is negligible compared to batch reactions.

[0036] Furthermore, the thermal energy circulation unit also includes a second heat exchanger 9 installed on the main feed pipeline 2. The heat transfer oil in the heat transfer oil circulation pipeline flows sequentially from the first tubular reactor to the last tubular reactor, then enters the second heat exchanger 9, and returns to the heat transfer oil receiving tank 5 after passing through the second heat exchanger 9. It can be seen that the heat transfer oil exiting the tubular reactor 1 carries some of the reaction heat, and its temperature is much higher than the ambient temperature. By setting up the second heat exchanger 9, the reaction heat is exchanged with the cold material about to enter the reaction unit, preheating the feed and significantly reducing energy consumption. Moreover, when the preheated material enters the first tubular reactor 1, its initial temperature is closer to the target reaction temperature, shortening the time required for the material to reach the reaction conditions in the tubular reactor 1, which further helps to improve the reaction rate.

[0037] Furthermore, the heat transfer oil circulation pipeline includes a main line 10, a first branch line 11, a second branch line 12, and a third branch line 13. The two ends of the main line 10 are connected to the outlet of the heat transfer oil receiving tank 5 and the inlet of the first heat exchanger 7, respectively. The first branch line 11 connects the outlet of the first heat exchanger 7 and the inlet of the first tubular reactor 1, and a first valve 14 is installed on the first branch line 11. One end of the second branch line 12 is connected to the main line 10, and the other end is connected to the first branch line 11. A second valve 15 is installed on the second branch line 12. The two ends of the third branch line 13 are connected to the outlet of the first heat exchanger 7 and the inlet of the heat transfer oil receiving tank 5, respectively. A third valve 16 is installed on the third branch line 13. (See attached...) Figure 1 It can be seen that the first branch 11 is divided into two parts by the second branch 12, namely the upstream branch and the downstream branch. The downstream branch is the necessary branch for the heat transfer oil, and the first valve 14 is located on the upstream branch of the first branch 11.

[0038] By operating the first valve 14, the second valve 15, and the third valve 16 described above, the system can achieve three operating modes, namely:

[0039] Heating mode (such as) Figure 2 As shown): The first heat exchanger 7 is connected to the steam heat source, the first valve 14 is opened, and the second valve 15 and the third valve 16 are closed. The heat transfer oil passes through the heat transfer oil pump 6, the first heat exchanger 7, and the first valve 14 in sequence before entering the first tubular reactor 1, thereby raising the temperature of the heat transfer oil in all tubular reactors 1.

[0040] Temperature control mode (such as) Figure 3 As shown): The first heat exchanger 7 is connected to the circulating cooling water source or steam heat source, the first valve 14 is closed, the second valve 15 is opened, and the opening of the third valve 16 is adjusted at the same time to control the ratio of oil flowing through the first heat exchanger 7 and the second branch 12 to achieve precise temperature control. Specifically, the heat transfer oil enters the first tubular reactor 1 after passing through the heat transfer oil pump 6 and the second valve 15 in sequence, while the first heat exchanger 7 is used to control the temperature of the heat transfer oil in the heat transfer oil receiving tank 5.

[0041] Emergency cooling mode (such as) Figure 3 As shown): The first heat exchanger 7 is connected to the circulating cooling water source, the second valve 15 and the third valve 16 are closed, the first valve 14 is opened, and the heat transfer oil passes through the heat transfer oil pump 6, the first heat exchanger 7 and the first valve 14 in sequence before entering the first tubular reactor 1 to rapidly cool the tubular reactor 1.

[0042] For further details, please refer to [link / reference]. Figure 1 The product separation unit also includes a solvent circulation pipeline 17. The inlet of the solvent circulation pipeline 17 is connected to the bottom liquid phase outlet of the gas-liquid separator 8, and its outlet is connected to the main feed pipeline 2. A solvent circulation pump 18 is installed on the solvent circulation pipeline 17. The above design realizes the efficient recovery and recycling of solvent in the reaction system. By directly returning the solvent-rich liquid phase material at the bottom of the gas-liquid separator 8 to the main feed pipeline 2, the solvent can circulate in a closed loop within the system, which greatly reduces the cost of raw material consumption. Moreover, the continuous circulation of solvent provides a key guarantee for maintaining the material balance and compositional stability of the entire reaction system.

[0043] Furthermore, the product separation unit also includes a third heat exchanger 19 installed on the top gas phase outlet pipe of the gas-liquid separator 8. The function of the third heat exchanger 19 is to precisely condense and liquefy the gas phase product coming out from the top of the gas-liquid separator 8, so as to facilitate the collection and metering of the product.

[0044] Furthermore, it also includes a back pressure valve 20 installed between the outlet of the last tubular reactor 1 and the gas-liquid separator. The back pressure valve 20 can ensure that the tubular reactors 1 connected in series can operate under a preset, stable pressure environment.

[0045] The workflow of this utility model is as follows:

[0046] When starting the system, first start the solvent circulation pump 18 to circulate the solvent throughout the reaction system, then start the heat transfer oil pump 6 to circulate the heat transfer oil. In heating mode, preheat the tubular reactor 1 to the initiation temperature. Adjust the back pressure valve 20 to the reaction pressure, then start the hexafluoropropylene feed pump 4 to introduce hexafluoropropylene. After a certain period of time, add a certain amount of oxygen to the first tubular reactor 1, and then add a certain amount of oxygen to each tubular reactor 1 after a certain period of time. The reaction products are separated in the gas-liquid separator 8, and the reaction products are cooled and discharged through the third heat exchanger 19, while the solvent is condensed back to the gas-liquid separator and recirculated into the main feed pipeline.

[0047] Using this system, the conversion rate of hexafluoropropylene can reach 70%~98%, the selectivity of hexafluoropropylene oxide is ≥50%, and the production process has low energy consumption and high safety, making it suitable for large-scale continuous production.

[0048] The present invention has been further described above with reference to specific embodiments. However, it should be understood that the specific description herein should not be construed as limiting the substance and scope of the present invention. Various modifications made by those skilled in the art to the above embodiments after reading this specification are all within the scope of protection of the present invention.

Claims

1. A continuous production system for hexafluoropropylene oxide, characterized in that, include: A reaction unit comprising at least two tubular reactors connected in series. The feeding unit includes a main feed pipeline connected to the first tubular reactor, and a hexafluoropropylene receiving tank is connected to the main feed pipeline via a feed pump. An oxygen supply unit, comprising multiple parallel oxygen branch pipes, the outlet of each oxygen branch pipe being connected to the feed end of one of the tubular reactors. A thermal energy circulation unit includes a heat transfer oil circulation pipeline, a heat transfer oil receiving tank disposed on the heat transfer oil circulation pipeline, a heat transfer oil pump, and a first heat exchanger. The heat transfer oil circulation pipeline passes through all the tubular reactors in sequence, and the heat transfer oil pump and the first heat exchanger are disposed downstream of the heat transfer oil receiving tank in sequence along the flow direction of the heat transfer oil. The product separation unit includes a gas-liquid separator connected to the discharge end of the last tubular reactor.

2. The continuous production system for hexafluoropropylene oxide according to claim 1, characterized in that, The thermal energy circulation unit also includes a second heat exchanger installed on the main feed pipeline. After the heat transfer oil circulation pipeline flows through all the tubular reactors, it enters the second heat exchanger and returns to the heat transfer oil receiving tank after passing through the second heat exchanger.

3. The continuous production system for hexafluoropropylene oxide according to claim 2, characterized in that, The heat transfer oil circulation pipeline includes: The main path is connected at both ends to the outlet of the heat transfer oil receiving tank and the inlet of the first heat exchanger, respectively. The first branch is connected to the outlet of the first heat exchanger and the inlet of the first tubular reactor, and a first valve is provided on the first branch. The second branch has one end connected to the main road and the other end connected to the first branch, and a second valve is provided on the second branch; The third branch is connected at both ends to the outlet of the first heat exchanger and the inlet of the heat transfer oil receiving tank, and a third valve is provided on the third branch.

4. The continuous production system for hexafluoropropylene oxide according to claim 1, characterized in that, The first heat exchanger is configured to selectively connect to a steam heat source or a circulating cooling water source.

5. The continuous production system for hexafluoropropylene oxide according to claim 1, characterized in that, The product separation unit also includes a solvent circulation pipeline. The inlet of the solvent circulation pipeline is connected to the bottom liquid phase outlet of the gas-liquid separator, and its outlet is connected to the main feed pipeline. A solvent circulation pump is installed on the solvent circulation pipeline.

6. The continuous production system for hexafluoropropylene oxide according to claim 1, characterized in that, The product separation unit also includes a third heat exchanger installed on the top gas phase outlet pipeline of the gas-liquid separator.

7. The continuous production system for hexafluoropropylene oxide according to claim 1, characterized in that, The tubular reactor is equipped with a mixer inside.

8. The continuous production system for hexafluoropropylene oxide according to claim 1, characterized in that, It also includes a back pressure valve located between the outlet of the last tubular reactor and the gas-liquid separator.

9. The continuous production system for hexafluoropropylene oxide according to claim 1, characterized in that, A flow meter is installed on the oxygen branch pipe.

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