A device for removing impurities from an electrolyte for an electrolytic fluorination process

Abstract

The utility model relates to electrolytic fluorination technical field, concretely relates to a kind of electrolytic fluorination process electrolyte's impurity removal device, including electrolyte temporary storage tank, electrolyte temporary storage tank's liquid inlet pipeline is connected with electrolyte outlet of electrolytic cell, electrolyte temporary storage tank bottom is provided magnetic force adsorption device, the liquid outlet of electrolyte temporary storage tank is connected with the liquid inlet of activated carbon adsorption tank, the liquid outlet of activated carbon adsorption tank is connected with the liquid inlet of centrifugal device, and net cylinder is equipped in centrifugal device, and the clearance between centrifugal device inner wall and net cylinder is filled with plastic ball, the bottom of centrifugal device is equipped with a circle baffle, baffle is located net cylinder inside, baffle inside is equipped with clear liquid outlet, and clear liquid outlet is connected with the liquid inlet of electrolyte storage tank.The utility model can effectively remove fluorinated metal, fluorine tar viscous impurities etc in electrolyte, and electrolyte after processing can be refluxed to electrolytic cell, ensure electrolytic efficiency, also reduce the cleaning frequency of electrolytic cell, prolong the operation cycle and service life of electrolytic cell.

Description

Technical Field

[0001] This utility model relates to the field of electrolytic fluorination technology, specifically to a device for removing impurities from the electrolyte in an electrolytic fluorination process. Background Technology

[0002] Perfluorinated organic compounds (PFOCs) possess chemical stability, surface activity, and excellent temperature resistance, making them widely used in many cutting-edge technologies and major industrial projects, as well as in the pharmaceutical and pesticide industries. Electrolytic fluorination is currently widely used in the preparation of PFOCs. Also known as the Simons process, it was developed by John Simons in the 1940s and first industrialized by 3M. It uses nickel as the anode and nickel or iron as the cathode. The reactants are dissolved in anhydrous hydrogen fluoride to form a conductive electrolyte. Electrolysis generates active fluorine atoms that directly replace hydrogen atoms in the reactants, producing the desired product at the anode and hydrogen gas at the cathode. Because the fluorinated organic compound is insoluble in hydrogen fluoride and has a higher density than liquid hydrogen fluoride, it gradually deposits at the bottom of the electrolytic cell. After a period of time, the electrolytic fluorination product is released, and after separation and purification, the desired product is obtained.

[0003] The biggest advantage of electrolytic fluorination lies in its directional fluorination, a single-step reaction that is simple. However, due to the combined effects of chemical and electrochemical corrosion on the equipment, and the cracking, cyclization, and rearrangement reactions of organic matter during electrolytic fluorination, various impurities, such as viscous tar-like liquids or solids, are generated in the electrolyte, leading to stratification. Increased impurity adhesion and deposition affect electrolysis efficiency. Furthermore, since the normal gap between the anode and cathode plates is 2-5 mm, excessive impurity adhesion and accumulation can create a clockwise short circuit between the plates. The high temperature generated by this clockwise short circuit can further deform the plates and carbonize organic matter in the electrolyte, forming a permanent short circuit. This causes a protective shutdown of the electrolysis process. Once this occurs, the electrolytic cell needs to be shut down for cleaning and electrode surface polishing. However, the electrolytic cell has many structural components, making disassembly inconvenient, costly in terms of manpower and resources, and increasing operational risks. Utility Model Content

[0004] To address the technical problem of various impurities generated in the electrolyte during electrolytic fluorination affecting electrolysis efficiency, this invention provides an impurity removal device for the electrolyte in the electrolytic fluorination process. This device can effectively remove fluorinated metals, fluorinated tar, and other viscous impurities from the electrolyte. The treated electrolyte can be returned to the electrolytic cell, thereby ensuring electrolysis efficiency, reducing the cleaning frequency of the electrolytic cell, and extending the operating cycle and service life of the electrolytic cell.

[0005] The technical solution of this utility model is as follows: A purification device for the electrolyte in an electrolytic fluorination process includes an electrolyte storage tank. The inlet pipe of the electrolyte storage tank is connected to the electrolyte outlet of multiple electrolytic cells. A magnetic adsorption device is installed at the bottom of the inner side of the electrolyte storage tank. The outlet of the electrolyte storage tank is connected to the inlet of an activated carbon adsorption tank. The outlet of the activated carbon adsorption tank is connected to the inlet of a centrifuge device via a metal hose. The centrifuge device has a mesh cylinder inside, and plastic balls are filled in the gap between the inner wall of the centrifuge device and the mesh cylinder. A baffle is installed at the bottom of the centrifuge device, located inside the mesh cylinder. The height of the baffle is one-tenth to one-fifth of the total internal height of the centrifuge device. A clear liquid outlet is provided inside the baffle. The clear liquid outlet is connected to the inlet of an electrolyte storage tank via a metal hose. The outlet of the electrolyte storage tank is connected to the electrolyte inlet of the electrolytic cell.

[0006] Furthermore, a pump is installed on the connecting pipe between the inlet of the electrolyte storage tank and the outlet of the electrolyte in the electrolytic cell.

[0007] Furthermore, the magnetic adsorption device is a fluorine-lined magnet block, and several magnet blocks are filled in the bottom of the inner side of the electrolyte storage tank. Preferably, the total volume of the several magnet blocks is one-sixth of the electrolyte storage tank.

[0008] Furthermore, a cooling jacket is provided on the outside of the activated carbon adsorption tank. The cooling jacket can cool the electrolyte in the activated carbon adsorption tank, increase the viscosity of the remaining fluorinated tar impurities in the electrolyte, and facilitate subsequent centrifugal separation.

[0009] Furthermore, the outlet of the activated carbon adsorption tank is equipped with a sieve plate with a mesh size of 50-100.

[0010] Furthermore, the casing of the centrifuge is made of stainless steel or Monel.

[0011] Furthermore, the centrifuge unit is equipped with a drain port at the bottom, located between the inner wall of the centrifuge unit and the mesh cylinder. The drain port is connected to a drain pipeline, which is equipped with a heating tape. Heating reduces the viscosity of fluorinated tar impurities, facilitating their discharge.

[0012] Furthermore, the height of the mesh cylinder should be adapted to the internal height of the centrifuge device, the thickness of the mesh cylinder should be 3~10mm, and the mesh size should be 80~300 mesh, with 80~150 mesh being preferred. The distance between the mesh cylinder and the inner wall of the centrifuge device should be 10~50mm. The mesh size of the mesh cylinder affects the centrifugation effect; an appropriate mesh size can ensure the removal of impurities such as fluorinated tar without affecting the quality of the electrolyte.

[0013] Furthermore, the mesh cylinder is made of plastic, preferably polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), fusible polytetrafluoroethylene (PFA), or ethylene-tetrafluoroethylene copolymer (ETFE), and more preferably polytetrafluoroethylene.

[0014] Furthermore, the electrolytic cell, electrolyte storage tank, activated carbon adsorption tank, and centrifuge are each equipped with a gas purging port, and the centrifuge is also equipped with an exhaust port.

[0015] Furthermore, a metering pump is installed on the connecting pipe between the electrolyte inlet of the electrolytic cell and the outlet of the electrolyte storage tank. As electrolyte is drawn from the electrolytic cell, new electrolyte from the storage tank is replenished into the electrolytic cell via the metering pump, maintaining the electrolyte level and ensuring that the electrolyte level keeps the electrode plates submerged.

[0016] Furthermore, considering the time required for tar discharge after centrifugation and the time required for regular maintenance, the optimal number of electrolytic cells connected in series with the electrolyte storage tank is three to fifteen.

[0017] Furthermore, the volume of the electrolyte storage tank is 1.5 to 2 times that of a single electrolytic cell.

[0018] The beneficial effects of this utility model are as follows: The impurity removal device for the electrolyte in the electrolytic fluorination process provided by this utility model is suitable for the electrolytic fluorination preparation of perfluoroalkyl sulfonyl fluorides, C6 to C6 fluorides. 15 The purification of electrolytes for high-density liquid products such as perfluorotertiary amines, perfluorocarbonyl fluorides, or perfluoroethers (perfluorodibutyl ether, perfluorodipentyl ether) not only meets the goal of multiple recycling of the electrolyte after treatment, but also increases the electrolytic operation cycle and service life of the electrolytic cell, reduces the frequency of electrolytic cell disassembly and electrode polishing, reduces the labor intensity and safety risks of operators, improves production efficiency, and ultimately reduces overall production costs and increases economic benefits. Connecting multiple electrolytic cells to the same purification device and using a staggered time arrangement allows multiple electrolytic cells to filter and purify the electrolyte in turn, resulting in high overall efficiency. Attached Figure Description

[0019] To more clearly illustrate the technical solution of this utility model, the drawings used in the description 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.

[0020] Figure 1 This is a schematic diagram of the impurity removal device for the electrolyte in the electrolytic fluorination process of Example 1.

[0021] Figure 2 This is a schematic diagram of the centrifuge device in Example 1.

[0022] In the diagram, 1-electrolytic cell, 2-electrolyte storage tank, 3-activated carbon adsorption tank, 4-centrifuge device, 5-magnetic block, 6-mesh cylinder, 7-baffle, 8-plastic ball, 9-electrolyte storage tank. Detailed Implementation

[0023] To make the objectives, features, and advantages of this utility model more apparent and understandable, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings of the specific embodiments. Obviously, the embodiments described below are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this patent, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this patent.

[0024] Example 1 like Figure 1 , Figure 2 As shown, a device for removing impurities from electrolyte in an electrolytic fluorination process includes an electrolyte storage tank 2. The inlet pipe of the electrolyte storage tank 2 is connected to the electrolyte outlet of three electrolytic cells 1. The electrolytic cells 1 have heating components. A pump is installed on the connecting pipe between the inlet of the electrolyte storage tank 2 and the electrolyte outlet of each electrolytic cell 1. Several fluorine-lined magnet blocks 5 are filled at the bottom inside the electrolyte storage tank 2. The outlet of the electrolyte storage tank 2 is connected to the inlet of the activated carbon adsorption tank 3, and a cooling jacket is provided on the outside of the activated carbon adsorption tank 3. The outlet of the activated carbon adsorption tank 3 is connected to the inlet of the centrifuge device 4 via a metal hose. The centrifuge device 4 is equipped with a mesh cylinder 6, the height of which is adapted to the internal height of the centrifuge device 4. The inlet of the centrifuge device 4 is located inside the mesh cylinder 6. Plastic balls 8 are filled in the gap between the inner wall of the centrifuge device 4 and the mesh cylinder 6. A baffle 7 is provided at the bottom of the centrifuge device 4, located inside the mesh cylinder 6. The height of the baffle 7 is one-fifth of the total internal height of the centrifuge device 4. A clear liquid outlet is provided inside the baffle 7, which is connected to the inlet of the electrolyte storage tank 9 via a metal hose. The bottom of the centrifuge device 4 is also equipped with a drain outlet, located between the inner wall of the centrifuge device 4 and the mesh cylinder 6. The drain outlet is connected to a drain pipe, and a heat tracing cable is provided on the drain pipe. The outlet of the electrolyte storage tank 9 is connected to the electrolyte inlet of the electrolytic cell 1, and a metering pump is installed on the connecting pipe between the electrolyte inlet of the electrolytic cell 1 and the outlet of the electrolyte storage tank 9.

[0025] The working principle of the impurity removal device in this embodiment is as follows: First, the electrolyte from which the product has been discharged is heated inside electrolytic cell 1. Simultaneously, the operating voltage of electrolytic cell 1 is adjusted to the maintenance voltage (0.05V). After running for a period of time, impurities adhering to the electrode plates are dislodged into the electrolyte. The heating element is then turned off. Once the electrolyte temperature decreases, a pump continuously draws electrolyte from the outlet of electrolytic cell 1 into electrolyte storage tank 2. A metering pump then replenishes electrolytic cell 1 with fresh electrolyte from electrolyte storage tank 9, maintaining the electrolyte level in electrolytic cell 1 so that the electrode plates are submerged. Solid impurities undergo primary sedimentation in electrolyte storage tank 2, while the electrolyte is temporarily stored... The fluorine-lined magnet block 5 at the bottom of tank 2 adsorbs the fallen iron-nickel residue; then the electrolyte is adsorbed by the activated carbon adsorption tank 3, and then enters the centrifuge device 4 through the metal hose. The relatively high-density tar-like impurities in the electrolyte are thrown to the outside of the mesh cylinder 6 by centrifugation, adhered to by the plastic balls 8 and fall down, and finally gather at the bottom of the centrifuge device 4 and are discharged from the drain port; while the relatively low-density liquid containing hydrogen fluoride and organic raw materials gathers inside the baffle 7 of the centrifuge device 4 and its height does not exceed the baffle 7. This part of the liquid enters the electrolyte storage tank 9 through the clear liquid outlet through the metal hose, and finally returns to the electrolytic cell 1 for continued use.

[0026] The electrolyte purification and circulation time of a single electrolytic cell 1 is 6-10 hours. By staggering the time, multiple electrolytic cells 1 can take turns to filter and purify the electrolyte.

[0027] Example 2 An impurity removal device for electrolyte in an electrolytic fluorination process, based on Example 1, wherein the inlet pipe of the electrolyte storage tank 2 is connected to the electrolyte outlet of fifteen electrolytic cells 1 respectively, and the total volume of the magnet blocks 5 filled in the bottom of the inner side of the electrolyte storage tank 2 is one-sixth of the volume of the electrolyte storage tank 2. The outlet of the activated carbon adsorption tank 3 is equipped with a sieve plate with a mesh size of 50~100 mesh. The activated carbon adsorption tank 3 uses honeycomb activated carbon with a size of 20mm*20mm*20mm and a mesh size of 20-40 mesh. The outer shell of the centrifuge device 4 is made of stainless steel or Monel; the mesh tube 6 is made of plastic, such as polytetrafluoroethylene, polyvinylidene fluoride, polyvinyl fluoride, fusible polytetrafluoroethylene or ethylene-tetrafluoroethylene copolymer, etc. To avoid safety hazards caused by increased pressure inside the centrifuge during centrifugation, an exhaust port is provided on centrifuge device 4, which is connected to the exhaust gas treatment system. The thickness of the inner screen 6 of the centrifuge device 4 is 3~10mm, the mesh size of the screen 6 is 80~300 mesh, with 80~150 mesh being preferred, and the distance between the screen 6 and the inner wall of the centrifuge device 4 is 10~50mm. The height of baffle 7 is one-tenth of the total internal height of centrifuge device 4; The electrolytic cell 1, electrolyte storage tank 2, activated carbon adsorption tank 3 and centrifuge device 4 are each equipped with a gas purging port, through which nitrogen or other inert gases can be used to pressurize and purge the interior of each device.

[0028] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A device for removing impurities from an electrolyte in an electrolytic fluorination process, comprising an electrolyte storage tank, characterized in that, The inlet pipe of the electrolyte storage tank is connected to the electrolyte outlet of multiple electrolytic cells. A magnetic adsorption device is installed at the bottom of the inner side of the electrolyte storage tank. The outlet of the electrolyte storage tank is connected to the inlet of the activated carbon adsorption tank. The outlet of the activated carbon adsorption tank is connected to the inlet of the centrifuge device through a metal hose. The centrifuge device has a mesh cylinder inside. The gap between the inner wall of the centrifuge device and the mesh cylinder is filled with plastic balls. A baffle is installed at the bottom of the centrifuge device. The baffle is located inside the mesh cylinder. The height of the baffle is one-tenth to one-fifth of the total height of the centrifuge device. A clear liquid outlet is provided inside the baffle. The clear liquid outlet is connected to the inlet of the electrolyte storage tank through a metal hose. The outlet of the electrolyte storage tank is connected to the electrolyte inlet of the electrolytic cell.

2. The impurity removal device for the electrolyte in an electrolytic fluorination process as described in claim 1, characterized in that, A pump is installed on the connecting pipe between the inlet of the electrolyte storage tank and the outlet of the electrolyte in the electrolytic cell.

3. The impurity removal device for the electrolyte in an electrolytic fluorination process as described in claim 1, characterized in that, The magnetic adsorption device consists of fluorine-lined magnet blocks, with several magnet blocks filled at the bottom of the inner side of the electrolyte storage tank.

4. The impurity removal device for the electrolyte in an electrolytic fluorination process as described in claim 1, characterized in that, The activated carbon adsorption tank is equipped with a cooling jacket on the outside.

5. The impurity removal device for the electrolyte in an electrolytic fluorination process as described in claim 1, characterized in that, The outlet of the activated carbon adsorption tank is equipped with a sieve plate with a mesh size of 50-100.

6. The impurity removal device for the electrolyte in an electrolytic fluorination process as described in claim 1, characterized in that, The centrifuge device is also equipped with a drain outlet at the bottom, which is located between the inner wall of the centrifuge device and the mesh cylinder. The drain outlet is connected to a drain pipeline, and a heat tracing cable is installed on the drain pipeline.

7. The impurity removal device for the electrolyte in an electrolytic fluorination process as described in claim 1, characterized in that, The height of the screen cylinder is adapted to the internal height of the centrifuge device. The thickness of the screen cylinder is 3~10mm, the mesh count is 80~300 mesh, and the distance between the screen cylinder and the inner wall of the centrifuge device is 10~50mm.

8. The impurity removal device for the electrolyte in an electrolytic fluorination process as described in claim 1, characterized in that, The electrolytic cell, electrolyte storage tank, activated carbon adsorption tank and centrifuge are each equipped with a gas purging port, and the centrifuge is also equipped with an exhaust port.

9. The impurity removal device for the electrolyte in an electrolytic fluorination process as described in claim 1, characterized in that, A metering pump is installed on the connecting pipe between the electrolyte inlet of the electrolytic cell and the outlet of the electrolyte storage tank.

10. The impurity removal device for the electrolyte in an electrolytic fluorination process as described in claim 1, characterized in that, The volume of the electrolyte storage tank is 1.5 to 2 times that of a single electrolytic cell.

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