Method and device for treating organic electrolyte

Abstract

The invention belongs to the field of fine chemical engineering and environmental protection, and particularly relates to an organic electrolyte treatment method and device. Adding the organic electrolyte into an electrolyte treatment tank, stirring, then heating, enabling hydrogen fluoride in the organic electrolyte to enter a hydrofluoric acid storage tank through a water washing tower, continuously heating, carrying out reduced pressure distillation, enabling distilled gas to enter an organic matter storage tank through a second heat exchanger, stopping distillation when the liquid level in the organic matter storage tank does not change any more, and stopping heating of the electrolyte treatment tank. And keeping the pressure, adding alkali liquor into the remaining solid residues after distillation, stirring and neutralizing to obtain mixed liquor, and performing electrochemical treatment on the mixed liquor to obtain nickel and iron elementary substances. According to the method provided by the invention, the purified organic matters can be recycled, and the generated hydrogen fluoride is washed with water to obtain concentrated acid. In addition, solid residues left after distillation are neutralized by alkali liquor and subjected to electrochemical treatment, and metal elementary substances are obtained. And efficient utilization of resources and sustainable development of the environment are realized in the whole technological process.

Description

Technical Field

[0001] The present application belongs to the field of fine chemicals, and specifically relates to a method and device for treating an organic electrolyte. Background Art

[0002] Perfluorosulfonic acid and its derivatives are among the earliest developed and most mature fluorine-containing organic compounds. They are prepared by organic electrochemical fluorination. These compounds play a vital role in the chemical industry. They are not only important chemical intermediates, but also important components of organic chemical raw materials and special chemicals. Perfluorosulfonic acid and its derivatives are widely used in the plastics industry. They are often used as catalysts for oligomerization and polymerization reactions, which greatly promotes the production efficiency and quality of plastic products. In the fuel industry, these compounds also play an important role. As protonation catalysts, they can effectively improve the combustion efficiency and performance of fuels. In addition, in the pharmaceutical industry, perfluorosulfonic acid and its derivatives also occupy a pivotal position. They are widely used as intermediates for antibiotics and protein drugs, providing a key step for the synthesis of drugs. In general, perfluorosulfonic acid and its derivatives occupy an extremely important position in the field of organic chemical reactions. Their application range covers a wide range of fields from plastics to fuels to pharmaceuticals. These compounds not only play a key role in industrial production, but also provide strong technical support in the field of fine chemicals, promoting the development and progress of the entire chemical industry.

[0003] In the production process of perfluorosulfonic acid and its derivatives, one of the most critical steps is the preparation of perfluorosulfonyl fluoride by electrochemical fluorination. This process usually uses sulfonyl fluoride and anhydrous hydrogen fluoride as electrolytes. However, due to the strong corrosiveness of the electrolyte itself, coupled with the corrosive effect of the electrochemical reaction under high voltage conditions, solid slag will be produced after the electrolyte runs in the electrolytic cell for a period of time. These solid slags will gradually accumulate and block the electrolyte channels in the electrolytic cell, causing the electrolytic cell to have to be shut down for disassembly and cleaning. During the cleaning process, the electrolyte is disposed of as waste liquid, which not only significantly increases the production cost of perfluorosulfonic acid, but also brings environmental pollution problems because the electrolyte contains organic fluorides.

[0004] The Chinese patent with announcement number CN117568823A discloses a method and device for purifying an electrochemical fluorination electrolyte, which specifically involves stirring the electrochemical fluorination electrolyte, then heating and distilling it under negative pressure, condensing the distilled gas to obtain a condensate, regulating the condensate, and adjusting the material to control the ratio of anhydrous hydrogen fluoride to sulfonyl fluoride organic matter in the condensate to 1:5, and then using it as an electrolyte again, and finally using alkaline solution to neutralize the remaining residue after distillation to reduce waste. However, in this application, hydrofluoric acid and other substances are evaporated together at 50-90°C and then condensed. When it is used again, the ratio of anhydrous hydrogen fluoride to sulfonyl fluoride organic matter needs to be strictly controlled, and the operation is relatively complicated. Secondly, the remaining residue after distillation is directly neutralized without further treatment, wasting metal nickel and iron and other substances in the residue.

[0005] In summary, there are still some unreasonable problems in the treatment of electrolyte for preparing perfluorosulfonic acid and its derivatives by electrolysis in the prior art, and it is urgent to propose a treatment method and device with high treatment efficiency and low environmental pollution. Summary of the invention

[0006] In view of the fact that there are still some unreasonable problems in the treatment of electrolyte for preparing perfluorosulfonic acid and its derivatives by electrolysis in the prior art, in order to reduce pollution to the environment, improve the efficiency of treatment, extend the service life of the electrolytic cell, and reduce the frequency of shutdown and cleaning, the present application provides a method and device for treating an organic electrolyte, which are as follows:

[0007] The technical solution of this application:

[0008] On the one hand, the present application provides a method for treating an organic electrolyte, wherein the organic electrolyte is first stirred for 0.5 to 1 hour, then heated to 40 to 50° C., hydrogen fluoride in the organic electrolyte is distilled out, and the temperature is continued to be raised to 50 to 90° C., and organic matter in the organic electrolyte is distilled out under a pressure of -0.093 to 0 MPa. The pressure is maintained, and an alkali solution is added to the solid residue remaining after the distillation and stirred for 1 to 1.5 hours to neutralize to obtain a mixed solution with a pH of 6.5 to 7.5, and the mixed solution is electrochemically treated to obtain nickel and iron elements.

[0009] Preferably, the alkali solution is a sodium hydroxide solution or a potassium hydroxide solution, and the concentration of the alkali solution is 10 to 15 mol / L.

[0010] Preferably, the conditions for the electrochemical treatment are: heating the mixed solution and applying electricity, the temperature is 50-70° C., the voltage is 30-50 V, and the pH of the mixed solution is controlled to be 6.5-7.5 during the electrochemical treatment.

[0011] On the other hand, the present application provides a treatment device for an organic electrolyte, comprising an electrolyte treatment tank, wherein the top of the electrolyte treatment tank is connected to the lower end of the side wall of a water washing tower, the bottom of the water washing tower is connected to a hydrofluoric acid storage tank through a pipeline, a density meter is provided on the pipeline, one end of the density meter is connected to the bottom of the water washing tower, and the other end is connected to the top of the hydrofluoric acid storage tank and the bottom of a first heat exchanger respectively through a three-way element, a circulating pump is provided on the pipelines of the first heat exchanger and the hydrofluoric acid storage tank, and the top of the first heat exchanger is connected to the top of the water washing tower; the upper end of the electrolyte treatment tank is connected to an alkali solution storage tank and an organic matter storage tank, and the bottom of the electrolyte treatment tank is also connected to a mixed liquid storage tank.

[0012] Preferably, a stirring mechanism is provided inside the electrolyte treatment tank for stirring the organic electrolyte, and the stirring mechanism includes stirring blades, a stirring shaft and a motor for driving the stirring shaft; a jacket is also provided outside the electrolyte treatment tank, and a medium for heating the electrolyte treatment tank is contained in the jacket; the electrolyte treatment tank is made of Hastelloy.

[0013] Preferably, a second heat exchanger is provided on the pipelines of the electrolyte treatment tank and the organic matter storage tank.

[0014] Preferably, the water washing tower is made of steel-lined PE material.

[0015] Preferably, the internal filler of the water washing tower is a ball ring.

[0016] Preferably, the hydrogen fluoride storage tank is made of steel-lined PE material.

[0017] Preferably, the circulating pump is made of polytetrafluoroethylene.

[0018] Beneficial effects of this application:

[0019] Electrochemical fluorination is the core process for preparing perfluorosulfonic acid and its derivatives. Since the electrolyte (mainly composed of hydrogen fluoride, fatty sulfonyl fluoride, nickel fluoride, iron fluoride, etc.) has strong corrosiveness and electrochemical corrosion under high voltage, the electrolyte will produce solid slag after running in the electrolytic cell for a period of time. The solid slag will block the passage of the electrolyte in the electrolytic cell, causing the electrolytic cell to shut down, dismantle the tank for cleaning, and the electrolyte will be treated as waste liquid. The present application proposes an environmentally friendly water-washing distillation method for purifying organic electrolytes. Through this method, the purified organic matter can be recycled as a raw material for a newly configured electrolyte. Specifically, the concentrated acid obtained by washing the hydrogen fluoride produced during the purification process can be sold as a by-product. In addition, the solid slag remaining after distillation can be neutralized with alkali solution and electrochemically treated to finally obtain a metal element and sell it to the outside. The entire process is strictly controlled, fully in line with the concept of green environmental protection, and realizes efficient utilization of resources and sustainable development of the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Attached Figure 1 A schematic diagram of an organic electrolyte treatment device of the present application;

[0021] Illustrations: 1. Electrolyte treatment tank; 2. Water washing tower; 3. First heat exchanger; 4. Circulation pump; 5. Hydrofluoric acid storage tank; 6. Second heat exchanger; 7. Organic matter storage tank; 8. Mixed liquid storage tank; 9. Alkali liquid storage tank; 10. Density meter; 11. Stirring mechanism. DETAILED DESCRIPTION

[0022] In order to further explain the technical means and effects adopted by the present application to achieve the predetermined invention purpose, the specific implementation method, structure, characteristics and effects of the present application are described in detail below in combination with the preferred embodiments.

[0023] Device Embodiment

[0024] See also Figure 1 This embodiment provides a device for treating an organic electrolyte, which includes an electrolyte treatment tank 1. The electrolyte treatment tank 1 is made of Hastelloy alloy and has high corrosion resistance. Before starting the test, the organic electrolyte is added to the electrolyte treatment tank 1 through the feed port. The electrolyte treatment tank 1 is provided with a jacket on the outside for heating the electrolyte treatment tank 1. The jacket is filled with circulating water as a heating medium. There is also a stirring mechanism 11 inside the electrolyte heater. The stirring mechanism 11 includes a stirring blade, a stirring shaft, and a motor for driving the stirring shaft to rotate. When starting to work, the stirring mechanism 11 is turned on to stir the organic electrolyte in the electrolyte treatment tank 1.

[0025] The top of the electrolyte treatment tank 1 of the present embodiment is connected to the lower end of the side wall of the water washing tower 2, and the bottom of the water washing tower 2 is connected to the hydrofluoric acid storage tank 5 through a pipeline. A density meter 10 is provided on the pipeline. One end of the density meter 10 is connected to the bottom of the water washing tower 2, and the other end is connected to the top of the hydrofluoric acid storage tank 5 and the bottom of the first heat exchanger 3 through a three-way element. A circulating pump 4 is provided on the pipelines of the first heat exchanger 3 and the hydrofluoric acid storage tank 5, and the top of the first heat exchanger 3 is connected to the top of the water washing tower 2. When the hydrogen fluoride gas in the organic electrolyte enters the water washing tower 2 through the pipeline from the upper end of the electrolyte treatment tank 1, it becomes hydrofluoric acid. Under the action of the circulation pump 4, the hydrofluoric acid solution in the water washing tower 2 is continuously circulated. When the display value of the density meter 10 is 0.961-0.977, the valve close to the hydrofluoric acid storage tank 5 is opened, and the hydrofluoric acid enters the hydrofluoric acid storage tank 5. Among them, the circulation pump 4 is made of tetrafluoroethylene material, the hydrogen fluoride storage tank is made of steel-lined PE material, the water washing tower 2 is made of steel-lined PE material, and the internal filler of the water washing tower 2 is ball ring.

[0026] The upper end of the electrolyte treatment tank 1 of this embodiment is connected to the organic matter storage tank 7 through a pipeline, and the pipelines between the electrolyte treatment tank 1 and the organic matter storage tank 7 are connected to a second heat exchanger 6. After the hydrogen fluoride in the organic electrolyte is completely volatilized, the valves on the pipelines of the electrolyte treatment tank 1 and the water washing tower 2 are closed, and the electrolyte treatment tank 1 is continuously heated. The organic matter in the organic electrolyte is volatilized under the heating condition, along the pipeline, through the second heat exchanger 6, and enters the organic matter storage tank 7 after condensation.

[0027] The upper end of the electrolyte treatment tank 1 of the present embodiment is also connected to an alkali solution treatment tank. After the organic matter in the electrolyte is volatilized, the valves on the pipelines of the electrolyte treatment tank 1 and the organic matter storage tank 7 are closed. Under negative pressure, the alkali solution in the alkali solution storage tank 9 enters the electrolyte treatment tank 1 and is neutralized with the distillation residue to obtain a mixed liquid.

[0028] The bottom of the electrolyte treatment tank 1 of the present embodiment is also connected to the mixed liquid storage tank 8, and the mixed liquid obtained after the neutralization treatment enters the mixed liquid storage tank 8 through a pipeline.

[0029] In this embodiment, the first heat exchanger 3 and the second heat exchanger 6 are both graphene heat exchangers.

[0030] Based on the device provided in the equipment embodiment, embodiments 1 to 3 provide a method for treating an organic electrolyte.

[0031] Example 1

[0032] Add 300Kg of organic electrolyte into the electrolyte treatment tank 1, start the electrolyte treatment tank 1 to stir, after stirring for 0.5h, start the electrolyte treatment tank 1 to heat, the temperature is controlled at 40℃, the hydrogen fluoride in the organic electrolyte gradually vaporizes and enters the water washing tower 2 for circulating washing, when the density meter 10 displays a value of 0.961, collect the hydrofluoric acid and enter the hydrofluoric acid storage tank 5, the concentration of hydrofluoric acid is 30%. Continue to heat up to 50℃, perform vacuum distillation, the pressure is -0.093Mpa, the distilled gas passes through the second heat exchanger 6 and enters the organic matter storage tank 7, when the liquid level in the organic matter storage tank 7 no longer changes, stop the distillation, and turn off the heating device of the electrolyte treatment tank 1. The negative pressure in the electrolyte treatment tank 1 is used to pump the potassium hydroxide solution with a concentration of 15 mol / L in the alkali solution storage tank 9 into the electrolyte treatment tank 1, and stirred for 1 hour. The slag is neutralized to a pH of 7.5 to obtain a mixed solution, and the mixed solution is heated and energized at a temperature of 70°C and a voltage of 45V. During the electrochemical treatment, the mixed pH is controlled to be 7.5 to obtain iron-nickel metal monomer.

[0033] Example 2

[0034] Add 300Kg of organic electrolyte into the electrolyte treatment tank 1, start the electrolyte treatment tank 1 to stir, after stirring for 0.5h, start the electrolyte treatment tank 1 to heat, the temperature is controlled at 45℃, the hydrogen fluoride in the organic electrolyte gradually vaporizes and enters the water washing tower 2 for circulating washing, when the density meter 10 displays a value of 0.962, collect the hydrofluoric acid and enter the hydrofluoric acid storage tank 5, the concentration of hydrofluoric acid is 50%. Continue to heat up to 70℃, perform vacuum distillation, the pressure is -0.090Mpa, the distilled gas passes through the second heat exchanger 6 and enters the organic matter storage tank 7, when the liquid level in the organic matter storage tank 7 no longer changes, stop the distillation, and turn off the heating device of the electrolyte treatment tank 1. The negative pressure in the electrolyte treatment tank 1 is used to pump the sodium hydroxide solution with a concentration of 10 mol / L in the alkali solution storage tank 9 into the electrolyte treatment tank 1, and stirred for 1 hour. The slag is neutralized to a pH of 6.5 to obtain a mixed solution, and the mixed solution is heated and energized at a temperature of 50°C and a voltage of 30V. During the electrochemical treatment, the mixed pH is controlled to be 6.5 to obtain iron-nickel metal monomer.

[0035] Example 3

[0036] Add 300Kg of organic electrolyte into the electrolyte treatment tank 1, start the electrolyte treatment tank 1 to stir, after stirring for 1h, start the electrolyte treatment tank 1 to heat, the temperature is controlled at 50℃, the hydrogen fluoride in the organic electrolyte gradually vaporizes and enters the water washing tower 2 for circulating washing, when the density meter 10 displays a value of 0.977, collect the hydrofluoric acid and enter the hydrofluoric acid storage tank 5, the concentration of hydrofluoric acid is 45%. Continue to heat up to 90℃, perform vacuum distillation, the pressure is -0.001Mpa, the distilled gas passes through the second heat exchanger 6 and enters the organic matter storage tank 7, when the liquid level in the organic matter storage tank 7 no longer changes, stop the distillation, and turn off the heating device of the electrolyte treatment tank 1. The negative pressure in the electrolyte treatment tank 1 is used to pump the sodium hydroxide solution with a concentration of 12 mol / L in the alkali solution storage tank 9 into the electrolyte treatment tank 1, and stirred for 1.5 hours. The slag is neutralized to a pH of 7 to obtain a mixed solution, and the mixed solution is heated and energized at a temperature of 60°C and a voltage of 50V. During the electrochemical treatment, the mixed pH is controlled to 7 to obtain iron-nickel metal monomer.

[0037] By using the method and device for treating the organic electrolyte of the present application, the purified organic matter can be recycled as a raw material for a newly configured electrolyte. Specifically, the concentrated acid obtained by washing the hydrogen fluoride produced in the purification process can be sold as a by-product. In addition, the solid residue remaining after distillation can be neutralized with alkaline solution and electrochemically treated to finally obtain a metal element and sell it. The entire process is strictly controlled to ensure that no waste residue, waste liquid and waste gas are generated, which is fully in line with the concept of green environmental protection and realizes efficient utilization of resources and sustainable development of the environment.

[0038] The above is only a preferred embodiment of the present application and does not constitute any form of limitation to the present application. Although the present application has been disclosed as a preferred embodiment as above, it is not intended to limit the present application. Any technical personnel in this field can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present application. However, any modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application are still within the scope of the technical solution of the present application.

Claims

1. A method for treating an organic electrolyte, characterized in that: The organic electrolyte is stirred for 0.5 to 1 hour, and then heated to 40 to 50° C. to distill out hydrogen fluoride in the organic electrolyte. The temperature is further raised to 50 to 90° C. to distill out organic matter in the organic electrolyte under a pressure of -0.093 to 0 MPa. The pressure is maintained, and alkali solution is added to the solid residue remaining after the distillation and stirred for 1 to 1.5 hours to neutralize to obtain a mixed solution with a pH of 6.5 to 7.

5. The mixed solution is electrochemically treated to obtain nickel and iron elements.

2. The method for treating an organic electrolyte according to claim 1, characterized in that: The alkali solution is a sodium hydroxide solution or a potassium hydroxide solution, and the concentration of the alkali solution is 10-15 mol / L.

3. The method for treating an organic electrolyte according to claim 1, characterized in that: The conditions of the electrochemical treatment are: heating the mixed solution and applying electricity, the temperature is 50-70° C., the voltage is 30-50V, and the pH of the mixed solution is controlled to be 6.5-7.5 during the electrochemical treatment.

4. A treatment device for treating an organic electrolyte according to any one of claims 1 to 3, characterized in that: The invention comprises an electrolyte treatment tank (1), wherein the top of the electrolyte treatment tank (1) is connected to the lower end of the side wall of a water washing tower (2), the bottom of the water washing tower (2) is connected to a hydrofluoric acid storage tank (5) through a pipeline, a density meter (10) is provided on the pipeline, one end of the density meter (10) is connected to the bottom of the water washing tower (2), and the other end is respectively connected to the top of the hydrofluoric acid storage tank (5) and the bottom of a first heat exchanger (3) through a three-way element, a circulation pump (4) is provided on the pipelines of the first heat exchanger (3) and the hydrofluoric acid storage tank (5), the top of the first heat exchanger (3) is connected to the top of the water washing tower (2), the upper end of the electrolyte treatment tank (1) is connected to an alkali solution storage tank (9) and an organic matter storage tank (7), and the bottom of the electrolyte treatment tank (1) is also connected to a mixed liquid storage tank (8).

5. The organic electrolyte treatment device according to claim 4, characterized in that: The electrolyte treatment tank (1) is provided with a stirring mechanism (11) inside for stirring the organic electrolyte, the stirring mechanism (11) comprising a stirring blade, a stirring shaft and a motor for driving the stirring shaft; the electrolyte treatment tank (1) is also provided with a jacket outside, the jacket contains a medium for heating the electrolyte treatment tank (1); the electrolyte treatment tank (1) is made of Hastelloy.

6. The organic electrolyte treatment device according to claim 4, characterized in that: A second heat exchanger (6) is provided on the pipelines of the electrolyte treatment tank (1) and the organic matter storage tank (7).

7. The organic electrolyte treatment device according to claim 4, characterized in that: The water washing tower (2) is made of steel-lined PE material.

8. The organic electrolyte treatment device according to claim 4, characterized in that: The internal filler of the water washing tower (2) is ball ring.

9. The organic electrolyte treatment device according to claim 4, characterized in that: The hydrogen fluoride storage tank is made of steel-lined PE material.

10. The organic electrolyte treatment device according to claim 4, characterized in that: The circulating pump (4) is made of polytetrafluoroethylene material.

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