An apparatus for the electrochemical fluorination of vdf to produce perfluorovinyl methyl ether

Abstract

The utility model discloses a kind of electrochemical fluorination VDF preparation perfluorovinyl methyl ether's device, belong to fluorine chemical equipment technical field.The device adopts integrated continuous flow structure, including electrolyte storage tank, VDF gas supply unit, electrolytic reaction unit, product post-treatment unit and electrolyte recovery system by pipeline sequentially connected.The boron-doped diamond anode plate and stainless steel cathode plate are arranged in parallel in the electrolytic reaction unit, its gas phase outlet is sequentially connected intermediate tank, rectification system and finished product condensation liquefaction system, liquid phase outlet connects electrolyte recovery system and returns electrolyte storage tank and constitutes circulation loop.The device is also provided with PLC controller, and signal connection with temperature sensor, direct current power supply and gas supply unit.The utility model passes through modularization structure design, solved the existing device electrode easy corrosion, system integration degree is low, waste liquid discharge big problem, with Compact structure, strong corrosion resistance, stable operation, environmental protection high efficiency advantage, suitable for perfluorovinyl methyl ether's large-scale continuous production.

Description

Technical Field

[0001] This utility model relates to the field of fluorochemical technology, specifically to an apparatus for preparing perfluorovinyl methyl ether by electrochemical fluorination of VDF. Background Technology

[0002] Perfluorovinyl methyl ether (PFME) is a key intermediate in the synthesis of high-performance fluorinated materials, with particularly strong demand in the field of high-end lithium-ion battery electrolytes. The technological level of its industrial production facilities directly affects product quality, production costs, and environmental impact.

[0003] Currently, the industry primarily relies on traditional Swarts fluorination units for production. The core of this unit is a batch-operated stirred tank reactor, requiring a complex solids feeding and waste treatment system. This unit suffers from the following structural defects: The solid waste treatment module is large and complex: a large amount of antimony-containing hazardous waste residue will be produced during the reaction process. The device must be equipped with a large solid-liquid separation unit and waste residue temporary storage facilities, resulting in a large equipment footprint and the risk of leakage and pollution.

[0004] Equipment corrosion and sealing challenges: The antimony-based fluorinating reagents used are highly corrosive, requiring extremely high-quality materials for the reactor. Furthermore, the frequent solid-phase feeding and slag discharge operations pose a severe challenge to the dynamic sealing structure, easily causing material leakage and affecting production safety and continuity.

[0005] Low system integration: From reaction to product separation and purification, the functional units are often discretely arranged, resulting in high energy consumption and large losses in the material transfer process, making it difficult to achieve fully automated continuous production.

[0006] To overcome the aforementioned problems, electrochemical fluorination is considered a green process route, and the corresponding electrochemical devices have become a key area of ​​research and development. However, existing laboratory or pilot-scale electrochemical devices have revealed numerous structural bottlenecks when scaled up to industrial applications: Electrode structure and material limitations: Existing devices mostly use metal electrodes such as nickel and platinum, which are prone to corrosion, passivation, or participation in side reactions in strong fluorinated environments, resulting in short electrode life and low current efficiency. The simple plate electrode structure also limits the mass transfer efficiency of the gas-liquid-solid three-phase reaction interface.

[0007] Lack of system integration and circulation functions: Existing devices often focus on the electrolysis reactor itself, lacking an integrated structural design that integrates functions such as precise raw material supply, efficient product separation, and online electrolyte regeneration. In particular, the electrolyte is usually considered a disposable consumable, and no effective circulation loop is designed into the device structure, resulting in high operating costs and the generation of a large amount of waste liquid.

[0008] The control module is disconnected from the actuator: the control of key parameters such as temperature, pressure and flow of the device relies on manual adjustment or independent instruments. The sensor, actuator (such as regulating valve) and power supply are not linked through an integrated control architecture, resulting in poor operating stability and failing to meet the control accuracy and reliability requirements of industrial continuous production.

[0009] Therefore, there is an urgent need in this field for a dedicated electrochemical fluorination device with a reasonable structural design, high functional integration, and suitability for continuous operation, so as to fundamentally solve the shortcomings of existing production equipment in terms of efficiency, environmental protection, and automation. Utility Model Content

[0010] To address the shortcomings of existing Swarts fluorination devices, such as complex solid waste treatment modules, susceptibility to corrosion, and structural defects in existing electrochemical devices including fragile electrode structures, low system integration, and a lack of electrolyte circulation units and control modules, this invention provides a novel apparatus for the electrochemical fluorination of VDF to produce perfluorovinyl methyl ether. This invention aims to solve the aforementioned problems through structural improvements, providing a compact, corrosion-resistant, highly integrated, and continuously automated production-capable specialized device.

[0011] To achieve the above objectives, the present invention adopts the following technical solution: An apparatus for the electrochemical fluorination of VDF to produce perfluorovinyl methyl ether is disclosed, which is structurally an integrated continuous flow system. Its core components include a material supply module, a reaction module, a product processing module, and a circulation module connected sequentially via pipelines.

[0012] The material supply module includes: The electrolyte supply unit, the core of which is the electrolyte storage tank; The VDF gas supply unit consists of a VDF storage tank, a VDF regulating valve, and a VDF meter connected sequentially by pipelines.

[0013] The reaction module is the electrolysis reaction unit, and its structure is as follows: The unit is equipped with a liquid inlet and a gas inlet, which are connected to the electrolyte storage tank and the VDF gas supply unit through pipelines, respectively. Inside its internal cavity, boron-doped diamond (BDD) anode plates and stainless steel cathode plates are arranged in parallel to form the core reaction component; the electrode spacing between the boron-doped diamond anode plates and the stainless steel cathode plates is 3-10 mm. The anode plate and cathode plate are electrically connected to an external DC power supply via a conductive busbar. The housing of this unit is also equipped with a temperature sensor for real-time monitoring of the internal operating conditions. The temperature sensor, DC power supply, VDF regulating valve and VDF meter are all connected to a PLC controller.

[0014] The device also includes multiple electrolysis reaction units arranged in parallel, with the electrolyte inlet of each unit connected to the electrolyte storage tank and the gas phase inlet of each unit connected to the VDF gas supply unit.

[0015] The product processing module structurally includes, along the material flow direction, the following components in sequence: The intermediate tank, whose inlet is connected to the gas phase outlet at the top of the electrolysis reaction unit via a pipe, is used to buffer and perform preliminary gas-liquid separation on the produced gas. The distillation system, whose inlet is connected to the gas phase outlet of the intermediate tank, is used to separate and purify the target product; The finished product condensation and liquefaction system has its inlet connected to the top outlet of the distillation system and is used to liquefy gaseous products. The inlet of the finished product storage tank is connected to the liquid outlet of the finished product condensation and liquefaction system via a pipe.

[0016] The circulation module structurally refers to an electrolyte recovery system. The inlet of this system is connected to the liquid phase outlet at the bottom of the electrolysis reaction unit via a pipe, and its outlet is connected to the electrolyte storage tank via a pipe, thus forming a closed electrolyte circulation loop in physical structure.

[0017] To further optimize the control structure and expand production capacity, this utility model device is also equipped with a PLC controller. This PLC controller is connected to the temperature sensor, DC power supply, VDF regulating valve, and VDF meter via signal cables, forming a centralized automatic control system within the device structure. To accommodate large-scale production, the device can include multiple electrolysis reaction units arranged in parallel, with the material inlet and outlet of each unit connected in parallel to the main pipeline via a manifold.

[0018] Compared with existing technology devices, this utility model, due to its integrated and modular structural design, has the following significant advantages directly resulting from structural improvements: 1. Compact structure and high integration: Multiple functional modules such as material supply, electrochemical reaction, product separation and purification, and electrolyte circulation are integrated into a continuous physical system through pipelines, eliminating redundant connections between unit equipment, occupying a small area and reducing material transmission loss.

[0019] 2. Corrosion-resistant core components with long service life: The use of chemically inert boron-doped diamond (BDD) as the anode plate material fundamentally solves the structural problem of traditional electrodes failing due to corrosion and passivation, ensuring that the device can achieve stable operation for over a thousand hours.

[0020] 3. Green and environmentally friendly, with minimal waste discharge: Due to the integration of a dedicated circulation module for electrolyte recovery system into the device structure, online purification and recycling of electrolyte are achieved, structurally eliminating the generation of large amounts of waste acid and waste liquid, which meets the equipment requirements of green chemical industry.

[0021] 4. High degree of automation and stable operation: By linking sensors, power supply and actuator (regulating valve) in the hardware structure through PLC controller, automatic feedback control of key process parameters is realized, which ensures the stability of the production process and the consistency of products from the device structure level.

[0022] 5. Easy to scale up and flexible in production capacity: The modular structure design with multiple electrolysis reaction units connected in parallel allows for flexible expansion of production capacity by simply increasing the number of parallel units proportionally, solving the structural problems encountered when scaling up the equipment from the laboratory to industrial production. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the system structure for preparing perfluorovinyl methyl ether by electrochemical fluorination of VDF according to the present invention.

[0024] In the diagram, 1-electrolyte storage tank; 2-VDF storage tank; 2.1-VDF regulating valve; 2.2-VDF meter; 3-electrolysis reaction unit; 3.1-anode; 3.2-cathode; 3.3-DC power supply; 3.4-temperature sensor; 3.5-PLC controller; 4-electrolyte recovery system; 5-intermediate tank; 6-distillation system; 7-finished product condensation and liquefaction system; 8-finished product storage tank. Detailed Implementation

[0025] The following is in conjunction with the appendix Figure 1 The specific embodiments of this utility model will be described in detail below. This embodiment is for illustrative purposes only and is not intended to limit the scope of protection of this utility model. Example

[0026] This embodiment describes an industrial plant suitable for producing 500 tons of perfluorovinyl methyl ether per year, the core structure of which is as follows: Figure 1 As shown.

[0027] This device is physically an integrated continuous flow system, with all units physically connected via pipes and valves. The device mainly includes the following modules: Material supply module: includes electrolyte storage tank 1 and VDF gas supply unit.

[0028] Reaction module: namely, electrolysis reaction unit 3.

[0029] Product processing module: includes an intermediate tank 5, a distillation system 6, and a finished product condensation and liquefaction system 7, which are connected in sequence.

[0030] Circulation module: namely, electrolyte recovery system 4.

[0031] Storage module: i.e. finished product storage tank 8.

[0032] Control module: namely PLC controller 3.5 and related sensors and actuators.

[0033] Functions of each module: (1) Material supply module Electrolyte storage tank 1: a tank with a volume of 50 m³ 3 The vertical flat-bottomed cylindrical storage tank is made of 316L stainless steel, and its bottom outlet is connected to the inlet of the reaction module through a corrosion-resistant fluoroplastic pipe.

[0034] The VDF gas supply unit includes a VDF storage tank 2 (pressure vessel), whose outlet is connected in series via a high-pressure metal pipeline to a VDF regulating valve 2.1 (pneumatic regulating valve) and a VDF meter 2.2 (Coriolis mass flow meter). The outlet pipeline of this unit is ultimately connected to the reaction module.

[0035] (2) Reaction module Electrolysis Reaction Unit 3: In this embodiment, 10 identical electrolysis reactors are connected in parallel. The shell of each electrolysis reactor is rectangular and is milled from polytetrafluoroethylene (PTFE) blocks, possessing excellent corrosion resistance and insulation.

[0036] Electrode Structure: Inside each reactor, a boron-doped diamond (BDD) anode plate 3.1 and a 316L stainless steel cathode plate 3.2 are fixed in parallel via built-in insulating clamps. The electrode spacing between the anode plate 3.1 and the cathode plate 3.2 is precisely set and fixed at 5 mm. The anode plate and cathode plate of each reactor are connected in parallel to an external DC power supply 3.3 (a high-power rectifier cabinet) via copper conductive busbars.

[0037] Monitoring point: A threaded hole is opened on each reactor shell and a PT100 temperature sensor 3.4 is installed, with its probe extending into the reaction chamber.

[0038] (3) Product processing module Intermediate tank 5: a 10 m 3 The jacketed buffer tank has its inlet connected via a pipe to a gas collection pipe that gathers the gas phase outlets at the top of all electrolysis reaction units 3.

[0039] Distillation System 6: This is a packed distillation column. The column body is made of stainless steel and filled with stainless steel wire mesh corrugated packing.

[0040] Finished product condensation and liquefaction system 7: is a shell-and-tube condenser, with chilled brine flowing through the shell side and the material side passing through the tubes.

[0041] (4) Loop Module Electrolyte recovery system 4: This is an integrated device whose inlet is connected via a pipe to a collection pipe that gathers the liquid phase outlets at the bottom of all electrolysis reaction units 3. Inside this integrated device, a bag filter (for removing mechanical impurities) and a vacuum degassing tower (for removing dissolved trace gases) are connected in series. Its outlet returns to the electrolyte storage tank 1 via a pipe, thus physically forming a complete electrolyte circulation loop.

[0042] (5) Storage module Finished product storage tank 8: a 30 m³ 3 The pressurized storage tank has its inlet connected to the liquid outlet of the finished product condensation and liquefaction system 7 via a pipeline.

[0043] (6) Control module PLC Controller 3.5: An industrial-grade programmable logic controller is used as the control core. It is electrically connected to all temperature sensors 3.4, DC power supply 3.3, VDF regulating valve 2.1, and VDF meter 2.2 via signal cables, thus forming a centralized automatic feedback control system in terms of hardware structure.

[0044] The working process of this utility model device is as follows: During startup, electrolyte is pumped from electrolyte storage tank 1 into each electrolysis reaction unit 3. VDF gas flows out from VDF storage tank 2, is precisely measured by VDF regulating valve 2.1 and VDF meter 2.2, and then stably flows into electrolysis reaction unit 3. PLC controller 3.5 dynamically adjusts the opening of VDF regulating valve 2.1 according to preset values ​​(such as VDF partial pressure 0.3 MPa).

[0045] After being energized, an electric field is formed between the BDD anode plate 3.1 and the stainless steel cathode plate 3.2, and VDF undergoes a fluorination reaction on the anode surface. The perfluorovinyl methyl ether gas generated by the reaction overflows from the top of the reaction unit and enters the intermediate tank 5, then flows sequentially through the distillation system 6 (purification) and the finished product condensation and liquefaction system 7 (liquefaction), and is finally stored in the finished product storage tank 8 in liquid form.

[0046] Meanwhile, the electrolyte after the reaction flows out from the bottom of the reaction unit and enters the electrolyte recovery system 4. After impurity removal and degassing, the clean electrolyte is pumped back to the electrolyte storage tank 1 for recycling. Throughout the process, the PLC controller 3.5 monitors the temperature of each reactor in real time and stabilizes the reaction temperature at the set 40℃ by adjusting the output of the DC power supply 3.3 and the cooling system.

[0047] The device described in this embodiment, with its modular physical structure, corrosion-resistant core component (BDD electrode), and integrated circulation and control unit, performed excellently during a continuous 720-hour operation test. The device operated smoothly, with seamless connections between units and no leakage or blockage. The purity of the produced product remained consistently above 98.5%, fully verifying the superiority, reliability, and industrial applicability of this invention's structural design.

[0048] The above description is merely a preferred embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the technical scope disclosed in this utility model, based on the technical solution and inventive concept of this utility model, should be included within the protection scope of this utility model.

Claims

1. An apparatus for the electrochemical fluorination of VDF to prepare perfluorovinyl methyl ether, characterized in that, include: Electrolyte storage tank (1); The VDF gas supply unit includes a VDF storage tank (2), a VDF regulating valve (2.1), and a VDF meter (2.2) connected sequentially by pipelines. The electrolysis reaction unit (3) has a liquid phase inlet connected to the electrolyte storage tank (1) via a pipe, and a gas phase inlet connected to the outlet of the VDF gas supply unit via a pipe. The internal cavity of the electrolysis reaction unit (3) is provided with a boron-doped diamond anode plate (3.1) and a stainless steel cathode plate (3.2) arranged in parallel. The anode plate (3.1) and the cathode plate (3.2) are connected to a DC power supply (3.3) via a conductive bus. The product post-processing unit has its inlet connected to the gas phase outlet at the top of the electrolysis reaction unit (3) via a pipe, and is provided with an intermediate tank (5), a distillation system (6) and a finished product condensation and liquefaction system (7) in sequence along the material flow direction. The inlet of the finished product storage tank (8) is connected to the liquid outlet of the finished product condensation and liquefaction system (7) via a pipe.

2. The apparatus according to claim 1, characterized in that, The bottom liquid phase outlet of the electrolysis reaction unit (3) is connected to the inlet of an electrolyte recovery system (4) through a pipe, and the outlet of the electrolyte recovery system (4) is connected to the electrolyte storage tank (1) through a pipe, forming an electrolyte circulation loop.

3. The apparatus according to claim 2, characterized in that, The electrolyte recovery system (4) is an integrated device that includes a filter and a vacuum degassing device.

4. The apparatus according to claim 1, characterized in that, The device includes multiple electrolysis reaction units (3) arranged in parallel. The electrolyte inlet of each unit is connected to the electrolyte storage tank (1), and the gas phase inlet of each unit is connected to the VDF gas supply unit.

5. The apparatus according to claim 1, characterized in that, A temperature sensor (3.4) is installed on the housing of the electrolysis reaction unit (3). The temperature sensor (3.4), DC power supply (3.3), VDF regulating valve (2.1) and VDF meter (2.2) are all connected to a PLC controller (3.5).

6. The apparatus according to claim 1, characterized in that, The electrode spacing between the boron-doped diamond anode plate (3.1) and the stainless steel cathode plate (3.2) is 3-10 mm.

7. The apparatus according to claim 1, characterized in that, The distillation system (6) is a packed distillation column.

8. The apparatus according to claim 1, characterized in that, The finished product condensation and liquefaction system (7) is a shell-and-tube condenser.

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