Silicon-fluorine electrolyte waste gas treatment agent, preparation method and electrolyte waste gas treatment method

Abstract

The application relates to a silicon-fluorine electrolyte waste gas treatment agent and a preparation method and an electrolyte waste gas treatment method, and belongs to the technical field of electrolyte waste gas treatment materials, and comprises 25-35 parts of a composite amine component, 35-45 parts of a functional alcohol ether component, 5-8 parts of a synergistic promoter, 2-4 parts of a stabilizer and 15-25 parts of deionized water, wherein the composite amine component is a mixture of N-methyldiethanolamine, N-(2-hydroxyethyl)ethylenediamine and triethanolamine, the functional alcohol ether component is a mixture of polyethylene glycol dimethyl ether and diethylene glycol butyl ether, the synergistic promoter is a mixture of beta-cyclodextrin and lauryl betaine, and the stabilizer is a mixture of sodium pyrophosphate and disodium ethylenediaminetetraacetate. The silicon-fluorine electrolyte waste gas treatment agent prepared by the application has high treatment efficiency and regeneration capacity.

Description

Technical Field

[0001] This application relates to the field of electrolyte waste gas treatment materials, and in particular to silicon-fluorine based electrolyte waste gas treatment agents and their preparation methods, as well as electrolyte waste gas treatment methods. Background Technology

[0002] The production and recycling of liquid lithium-ion batteries generate electrolyte waste gas with complex compositions, mainly containing silicon-fluorine compounds such as trimethylfluorosilane and hexamethyldisiloxane, ester organic compounds such as dimethyl carbonate and ethyl methyl carbonate, and inorganic pollutants such as HF and PF5. This type of waste gas is highly corrosive and difficult to degrade. Improper treatment can cause equipment corrosion and air pollution. Furthermore, silicon compounds easily form deposits in subsequent treatment equipment (such as RTO heat storage bodies), leading to equipment blockage or deactivation.

[0003] Existing electrolyte waste gas treatment technologies have many shortcomings: traditional alkaline scrubbing towers can only remove some inorganic acids, with an absorption rate of less than 45% for silicon fluorine compounds and ester organics. Furthermore, esters will preferentially hydrolyze in high pH environments, further reducing treatment efficiency. Activated carbon adsorption methods are prone to rapid saturation of the adsorbent due to competitive adsorption of multiple components in the waste gas, resulting in high maintenance costs. Combustion methods produce corrosive gases such as HF, and silicon oxides can cause blockage of the heat storage medium and deactivation of the catalyst. While some existing waste gas treatment agents can improve the absorption efficiency of silicon fluorine compounds, they suffer from poor regeneration performance, limited recycling times, and insufficient treatment capacity when mixed waste gases contain multiple components such as silicon fluorine compounds, ester organics, and inorganic pollutants. These limitations make it difficult to meet the dual requirements of in-depth treatment and low-cost operation in industrial scenarios. Summary of the Invention

[0004] The purpose of this application is to address the shortcomings of existing silicon-fluorine based electrolyte waste gas treatment agents, which are difficult to simultaneously achieve treatment efficiency, regeneration performance, and number of cycles. Therefore, this application proposes a silicon-fluorine based electrolyte waste gas treatment agent, its preparation method, and a method for treating electrolyte waste gas.

[0005] In a first aspect, the silicon-fluorine based electrolyte waste gas treatment agent provided in this application adopts the following technical solution: the raw material components of the silicon-fluorine based electrolyte waste gas treatment agent include, by mass parts: 25-35 parts of complex amine components, 35-45 parts of functional alcohol ether components, 5-8 parts of synergistic promoters, 2-4 parts of stabilizers, and 15-25 parts of deionized water, wherein the complex amine components are a mixture of N-methyldiethanolamine, N-(2-hydroxyethyl)ethylenediamine, and triethanolamine; the functional alcohol ether components are a mixture of polyethylene glycol dimethyl ether and diethylene glycol butyl ether; the synergistic promoter is a mixture of β-cyclodextrin and lauryl betaine; and the stabilizer is a mixture of sodium pyrophosphate and disodium ethylenediaminetetraacetate.

[0006] Through the above technical solutions, N-(2-hydroxyethyl)ethylenediamine in the composite amine component initiates a nucleophilic attack on the Si-F bonds of silicon-fluorine compounds, polarizing them. N-methyldiethanolamine then coordinates and complexes with the polarized silicon atoms. The two form a relay-like synergy during the absorption process, significantly improving the absorption rate of silicon-fluorine compounds compared to a single amine system. The polyhydroxyethyl group of triethanolamine forms hydrogen bond bridges with the absorption products of the aforementioned two amines, making the absorption products easier to desorb during regeneration, providing a basis for the recycling of the treatment agent. The combination of the two alcohol ethers makes the system far more adaptable to multi-component mixed waste gases than a single alcohol ether system. In the synergistic promoter, lauryl betaine reduces the gas-liquid interfacial tension and increases the mass transfer area. Its inclusion effect with β-cyclodextrin forms a synergistic mass transfer from the interface to the bulk phase, significantly improving the overall mass transfer efficiency of the treatment agent. In the stabilizer, sodium pyrophosphate and disodium ethylenediaminetetraacetate work together to maintain the long-term stability of the treatment agent. The multiple synergistic effects among the above components enable the treatment agent to achieve highly efficient synergistic treatment of silicon fluorine compounds and ester organic compounds.

[0007] Optionally, the raw material components of the silicon-fluorine based electrolyte waste gas treatment agent include, by mass, 15-20 parts N-methyldiethanolamine, 8-12 parts N-(2-hydroxyethyl)ethylenediamine, 2-3 parts triethanolamine, 25-30 parts polyethylene glycol dimethyl ether, 10-15 parts diethylene glycol butyl ether, 3-5 parts β-cyclodextrin, 2-3 parts lauryl betaine, 1-2 parts sodium pyrophosphate, 1-2 parts disodium ethylenediaminetetraacetate, and 15-25 parts deionized water.

[0008] Optionally, the raw material components of the fluorine-based electrolyte waste gas treatment agent include, by weight: 18 parts N-methyldiethanolamine, 10 parts N-(2-hydroxyethyl)ethylenediamine, 2.5 parts triethanolamine, 28 parts polyethylene glycol dimethyl ether, 12 parts diethylene glycol butyl ether, 4 parts β-cyclodextrin, 2.5 parts lauryl betaine, 1.5 parts sodium pyrophosphate, 1.5 parts disodium ethylenediaminetetraacetate, and 20 parts deionized water.

[0009] Secondly, this application provides a method for preparing the above-mentioned silicon-fluorine based electrolyte waste gas treatment agent, the preparation method comprising the following steps:

[0010] S1. Weigh the raw material components of the silicon-fluorine electrolyte waste gas treatment agent according to the ratio, and add the stabilizer to deionized water at 35~45 ℃ and under stirring conditions to carry out the first mixing to form a first mixing system. Then add the composite amine component to the first mixing system to carry out the second mixing to form a second mixing system.

[0011] S2. Add the functional alcohol ether component to the second mixing system in batches and mix them to form a third mixing system;

[0012] S3. At 25~30 ℃, the synergistic promoter is added to the third mixing system and mixed. Then the pH is adjusted to 9.0~9.5, and finally filtered to obtain the silicon-fluorine electrolyte waste gas treatment agent.

[0013] Through the above technical solution, in step S1, the stabilizer (sodium pyrophosphate and disodium ethylenediaminetetraacetate) is dissolved first, and then the composite amine component is added. The phosphate group and the amine group may form a weak hydrogen bond association in advance, providing a spatial pre-position for the subsequent amine component to synergistically absorb silicon fluorine compounds. If the order is reversed, the amine component has formed a disordered distribution in the water, and the stabilizer is difficult to insert effectively. In step S2, the alcohol ether component is added in batches, so that polyethylene glycol dimethyl ether gradually builds an ordered solvation layer around the amine component, and diethylene glycol butyl ether orderly fills the gaps to form an amphiphilic structure. If the alcohol ether component is added all at once, it can be added in batches. It can easily self-polymerize to form an independent phase rather than an ordered encapsulation of amine components; in step S3, after cooling to 25~30℃, synergistic promoters (β-cyclodextrin and lauryl betaine) are added. The lower temperature allows the β-cyclodextrin cavity to maintain a stable conformation, so that the lauryl betaine alkyl chain can be effectively and orientedly inserted into the cavity entrance; the pH is adjusted to 9.0~9.5 to maintain sufficient nucleophilic activity of the amine components, while the triethanolamine hydroxyl group is at an appropriate degree of deprotonation to enhance the hydrogen bond bridging ability. The above stepwise process ensures that each synergistic structure is constructed in an orderly manner step by step, ensuring the stability and consistency of the treatment agent's performance.

[0014] Optionally, in step S1, the stabilizer is added to deionized water for the first mixing under stirring conditions at 40~42 °C; in step S3, the synergistic promoter is added to the third mixing system for mixing at 26~28 °C.

[0015] Through the above technical solutions, 40~42℃ is the optimal temperature window for the formation of pre-associates between phosphate and amino groups. At this temperature, the balance between hydrogen bonding forces and thermal motion results in the optimal formation rate and stability of the pre-associate. At 26~28℃, the β-cyclodextrin cavity conformation is most stable, and the directional insertion effect of lauryl betaine is optimal, resulting in the highest integrity of the synergistic structures of the prepared treatment agent and the best waste gas treatment performance and regeneration stability.

[0016] Thirdly, this application provides a method for treating electrolyte waste gas, the method comprising: passing the silicon-fluorine based electrolyte waste gas into an absorption tower for absorption treatment, wherein the absorbent used in the absorption tower is the silicon-fluorine based electrolyte waste gas treatment agent described above.

[0017] Through the above technical solution, the absorption rate of the treatment agent for trimethylfluorosilane is ≥95%, and the absorption rate of dimethyl carbonate is ≥98%. Due to the hydrogen bond bridging of triethanolamine, the absorption products are maintained in a reversible dissociation state, and the activity retention rate of the regenerated treatment agent is ≥90%. It can be recycled 8 to 10 times. After two-stage absorption treatment, the concentration of non-methane total hydrocarbons in the exhaust gas is ≤30 mg / m³, and the concentration of fluoride is ≤1 mg / m³, which meets the air pollutant emission standards.

[0018] In a specific implementation, before the waste gas from the silicon-fluorine electrolyte is introduced into the absorption tower for absorption treatment, the waste gas is pretreated. The pretreatment mainly involves removing solid particles from the electrolyte waste gas through a high-efficiency filter (filtration accuracy ≤1 μm), and then cooling it to 25~35 ℃ through a heat exchanger. The pretreatment removes particulate matter and droplets from the waste gas, preventing them from damaging the solvation layer and amphiphilic structure in the treatment agent.

[0019] In a specific implementation, multi-stage cascade absorption allows the synergistic mechanisms at different levels in the treatment agent to exert their maximum efficiency at different absorption stages. In the first-stage absorption tower, the relay-style synergy of amine components and the inclusion effect of β-cyclodextrin bear the main absorption load, while in the second-stage absorption tower, the solvation and enrichment of alcohol and ether components deeply absorb the residual low-concentration ester organic matter.

[0020] Optionally, in the waste gas from the silicon-fluorine electrolyte, the mass concentration of trimethylfluorosilane is 500~2000 mg / m³. 3 The mass concentration of dimethyl carbonate is 800~3000 mg / m³. 3 .

[0021] Optionally, the liquid-to-gas ratio of the silicon-fluorine based electrolyte waste gas treatment agent to the silicon-fluorine based electrolyte waste gas is 5~8 L / m³. 3 .

[0022] Through the above technical solution, the liquid film thickness formed on the packing surface by the treatment agent at the liquid-to-gas ratio is moderate, and the pollutant molecules in the waste gas can fully diffuse into the interior of the liquid film and react with the active components. When the liquid-to-gas ratio is too low, the liquid film coverage is incomplete, resulting in some waste gas not being effectively absorbed. When the liquid-to-gas ratio is too high, the liquid phase mass transfer resistance increases and the pumping energy consumption increases. 5~8 L / m³ achieves the best balance between treatment efficiency and operating cost.

[0023] Optionally, the electrolyte waste gas treatment method further includes the regeneration treatment of the silicon-fluorine based electrolyte waste gas treatment agent. The regeneration treatment method includes: mixing the deactivated silicon-fluorine based electrolyte waste gas treatment agent with a composite activator, stirring at 45~55 °C, then allowing it to stand and separate into layers, removing the precipitate, and taking the upper clear liquid, which is the regenerated silicon-fluorine based electrolyte waste gas treatment agent. The composite activator is a mixture of sodium hydroxide solution and ethanolamine solution with a mass ratio of 2~5:1.

[0024] The deactivation of the treatment agent, achieved through the above technical solution, is due to the aminosilane complex occupying the active sites of the amines, filling the β-cyclodextrin cavity. The OH⁻ provided by sodium hydroxide undergoes nucleophilic substitution with the silicon atoms in the complex, desorbing the silanine-fluorine compound as a silicate from the active sites. Simultaneously, it disrupts key nodes in the hydrogen bond bridging of triethanolamine, promoting the dissociation of the absorption product. Ethanolamine molecules competitively replace the silanine-fluorine compound in the β-cyclodextrin cavity, with their amino and hydroxyl groups forming temporary hydrogen bonds with the cavity wall to prevent deformation during the replacement process. The two work synergistically: OH⁻ initiates the dissociation of the complex first, followed by ethanolamine completing the cavity replacement; the synergistic regeneration efficiency is far higher than using either component alone. A temperature of 45–55°C provides a suitable driving force for the above regeneration reaction without triggering component degradation.

[0025] In this article, the deactivated silicon-fluorine electrolyte waste gas treatment agent refers to the silicon-fluorine electrolyte waste gas treatment agent in which the trimethylfluorosilane absorption rate drops to below 80% after waste gas absorption treatment.

[0026] Further optionally, the mass ratio of the sodium hydroxide solution to the ethanolamine solution is 3:1; the amount of the composite activator added is 5-8% of the mass of the deactivated silicon-fluorine electrolyte waste gas treatment agent.

[0027] The above technical solution achieves the highest synergistic efficiency of alkaline desorption and competitive replacement at a mass ratio of 3:1. When the ratio is too low, excess ethanolamine will compete with existing amine components for active sites, interfering with the synergistic absorption mechanism of the treatment agent. When the ratio is too high, excess OH⁻ easily triggers degradation of amine components and ring-opening hydrolysis of β-cyclodextrin. An addition amount of 5-8% ensures that the molar ratio of OH⁻ to the complex is in a slightly excess range, and the molar ratio of ethanolamine to the cavity inclusion complex is just right for complete replacement. Insufficient addition leads to incomplete regeneration, while excess dilutes the concentration of the treatment agent and disrupts the synergistic balance between the components.

[0028] In summary, this application includes at least one of the following beneficial technical effects:

[0029] 1. This application achieves highly efficient synergistic treatment of silicon fluorine compounds, ester organics and inorganic pollutants in electrolyte waste gas through multiple synergistic effects, including relay synergistic absorption among complex amine components, hydrogen bond bridging and stabilization of triethanolamine, solvation layer and amphiphilic structure constructed by alcohol ether components, and inclusion-mass transfer synergy of β-cyclodextrin and lauryl betaine. The absorption rate of trimethylfluorosilane is ≥95%, the absorption rate of dimethyl carbonate is ≥98%, and the treated waste gas meets the emission standards. The overall performance is significantly better than that achieved by simply adding the components together.

[0030] 2. This application ensures the consistency of performance and long-term storage stability of the treatment agent by matching the feeding sequence and temperature gradient in the stepwise preparation process with the stepwise construction process of each synergistic structure;

[0031] 3. In the preferred case, through the alkaline desorption and competitive displacement synergistic regeneration mechanism of the composite activator composed of sodium hydroxide and ethanolamine, combined with the reversible dissociation channel reserved by the hydrogen bond bridging of triethanolamine, the activity retention rate after regeneration is ≥87%, and it can be recycled 10 times, which solves the problems of poor regeneration performance and limited recycling times of the treatment agent in the prior art. Detailed Implementation

[0032] The present application will be further described in detail below with reference to specific embodiments.

[0033] The following examples further illustrate the silicon-fluorine based electrolyte waste gas treatment agent and its preparation method, as well as the electrolyte waste gas treatment method described in this application. These examples are implemented based on the technical solution of this application, providing detailed implementation methods and specific operating procedures. However, the scope of protection of this application is not limited to the following examples.

[0034] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods in the art. Unless otherwise specified, the experimental materials used in the following embodiments are commercially available.

[0035] Polyethylene glycol dimethyl ether: Purchased from Shanghai Aladdin Biochemical Technology Co., Ltd., product number P432396, average Mn~1000;

[0036] β-Cyclodextrin: Purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.;

[0037] Lauryl betaine: Purchased from Shanghai Yuanye Biotechnology Co., Ltd.

[0038] Examples 1-3 describe silicon-fluorine based electrolyte waste gas treatment agents and their preparation methods.

[0039] Example 1

[0040] A fluorosilicone-based electrolyte waste gas treatment agent comprises, by weight, the following raw material components: 18 parts N-methyldiethanolamine, 10 parts N-(2-hydroxyethyl)ethylenediamine, 2.5 parts triethanolamine, 28 parts polyethylene glycol dimethyl ether, 12 parts diethylene glycol butyl ether, 4 parts β-cyclodextrin, 2.5 parts lauryl betaine, 1.5 parts sodium pyrophosphate, 1.5 parts disodium ethylenediaminetetraacetate, and 20 parts deionized water.

[0041] The preparation method of the above-mentioned silicon-fluorine based electrolyte waste gas treatment agent includes the following steps:

[0042] S1. Weigh each raw material component according to the above proportions, add 20 parts of deionized water to the reaction vessel, turn on the stirring device, set the stirring speed to 300 r / min, and heat to 41 ℃. Under stirring conditions, first add 1.5 parts of sodium pyrophosphate and 1.5 parts of disodium ethylenediaminetetraacetate to the deionized water, stir and mix for 20 min until completely dissolved to form the first mixed system; then add 18 parts of N-methyldiethanolamine, 10 parts of N-(2-hydroxyethyl)ethylenediamine and 2.5 parts of triethanolamine to the first mixed system in sequence, and continue stirring and mixing for 30 min until the system is uniform and transparent to form the second mixed system.

[0043] S2. Maintain the temperature of the reactor at 41 ℃, and add the functional alcohol ether component to the second mixing system in three batches: the first batch is 14 parts of polyethylene glycol dimethyl ether, and stirred for 10 min; the second batch is 14 parts of polyethylene glycol dimethyl ether and 6 parts of diethylene glycol butyl ether, and stirred for 10 min; the third batch is 6 parts of diethylene glycol butyl ether, and stirred for 15 min to form the third mixing system.

[0044] S3. Cool the reactor to 27 °C, add 4 parts of β-cyclodextrin and 2.5 parts of lauryl betaine to the third mixing system, stir and mix for 25 min, then adjust the pH of the system to 9.2 with dilute sodium hydroxide solution (mass concentration of 5%), and finally filter through a 200-mesh filter to remove insoluble impurities to obtain the silicon-fluorine based electrolyte waste gas treatment agent.

[0045] Example 2

[0046] A fluorosilicone-based electrolyte waste gas treatment agent comprises, by weight, the following raw material components: 15 parts N-methyldiethanolamine, 8 parts N-(2-hydroxyethyl)ethylenediamine, 2 parts triethanolamine, 25 parts polyethylene glycol dimethyl ether, 10 parts diethylene glycol butyl ether, 3 parts β-cyclodextrin, 2 parts lauryl betaine, 1 part sodium pyrophosphate, 1 part disodium ethylenediaminetetraacetate, and 15 parts deionized water.

[0047] The preparation method of the above-mentioned silicon-fluorine based electrolyte waste gas treatment agent includes the following steps:

[0048] S1. Weigh each raw material component according to the above ratio, add 15 parts of deionized water to the reaction vessel, turn on the stirring device, set the stirring speed to 200 r / min, and heat to 35 ℃. Under stirring conditions, first add 1 part of sodium pyrophosphate and 1 part of disodium ethylenediaminetetraacetate to the deionized water, stir and mix for 20 min until completely dissolved to form the first mixed system; then add 15 parts of N-methyldiethanolamine, 8 parts of N-(2-hydroxyethyl)ethylenediamine and 2 parts of triethanolamine to the first mixed system in sequence, and continue stirring and mixing for 30 min until the system is uniform and transparent to form the second mixed system.

[0049] S2. Maintain the temperature of the reactor at 35 ℃, and add the functional alcohol ether component to the second mixing system in three batches: the first batch is 12.5 parts of polyethylene glycol dimethyl ether, and stirred for 15 min; the second batch is 12.5 parts of polyethylene glycol dimethyl ether and 5 parts of diethylene glycol butyl ether, and stirred for 10 min; the third batch is 5 parts of diethylene glycol butyl ether, and stirred for 20 min to form the third mixing system.

[0050] S3. Cool the reactor to 25 °C, add 3 parts β-cyclodextrin and 2 parts lauryl betaine to the third mixing system, stir and mix for 30 min, then adjust the pH of the system to 9.0 with dilute sodium hydroxide solution (mass concentration of 5%), and finally filter through a 200-mesh filter to remove insoluble impurities to obtain a silicon-fluorine based electrolyte waste gas treatment agent.

[0051] Example 3

[0052] A fluorosilicone-based electrolyte waste gas treatment agent comprises, by weight, the following raw material components: 20 parts N-methyldiethanolamine, 12 parts N-(2-hydroxyethyl)ethylenediamine, 3 parts triethanolamine, 30 parts polyethylene glycol dimethyl ether, 15 parts diethylene glycol butyl ether, 5 parts β-cyclodextrin, 3 parts lauryl betaine, 2 parts sodium pyrophosphate, 2 parts disodium ethylenediaminetetraacetate, and 25 parts deionized water.

[0053] The preparation method of the above-mentioned silicon-fluorine based electrolyte waste gas treatment agent includes the following steps:

[0054] S1. Weigh each raw material component according to the above proportions, add 25 parts of deionized water to the reaction vessel, turn on the stirring device, set the stirring speed to 250 r / min, and heat to 45 ℃. Under stirring conditions, first add 2 parts of sodium pyrophosphate and 2 parts of disodium ethylenediaminetetraacetate to the deionized water, stir and mix for 18 min until completely dissolved to form the first mixed system; then add 20 parts of N-methyldiethanolamine, 12 parts of N-(2-hydroxyethyl)ethylenediamine and 3 parts of triethanolamine to the first mixed system in sequence, and continue stirring and mixing for 25 min until the system is uniform and transparent to form the second mixed system.

[0055] S2. Maintain the temperature of the reactor at 45 ℃, and add the functional alcohol ether component to the second mixing system in three batches: the first batch is 15 parts of polyethylene glycol dimethyl ether, and stirred for 12 min; the second batch is 15 parts of polyethylene glycol dimethyl ether and 7.5 parts of diethylene glycol butyl ether, and stirred for 12 min; the third batch is 7.5 parts of diethylene glycol butyl ether, and stirred for 18 min to form the third mixing system.

[0056] S3. Cool the reactor to 30 ℃, add 5 parts of β-cyclodextrin and 3 parts of lauryl betaine to the third mixing system, stir and mix for 28 min, then adjust the pH of the system to 9.5 with dilute sodium hydroxide solution (mass concentration of 5%), and finally filter through a 200-mesh filter to remove insoluble impurities to obtain the silicon-fluorine based electrolyte waste gas treatment agent.

[0057] Comparative Examples 1-7 are the treatment agents and their preparation methods.

[0058] Comparative Example 1

[0059] The procedure was carried out in accordance with Example 1, except that the complex amine component used only N-methyldiethanolamine as a single amine component. That is, 30.5 parts of N-methyldiethanolamine replaced 18 parts of N-methyldiethanolamine, 10 parts of N-(2-hydroxyethyl)ethylenediamine and 2.5 parts of triethanolamine in Example 1. The remaining raw material components and preparation methods were the same as in Example 1.

[0060] Comparative Example 2

[0061] The method of Example 1 was followed, except that the functional alcohol ether component used only polyethylene glycol dimethyl ether (PEG dimethyl ether) as the single alcohol ether component. That is, 40 parts of PEG dimethyl ether replaced 28 parts of PEG dimethyl ether and 12 parts of diethylene glycol butyl ether in Example 1. The remaining raw material components and preparation methods were the same as in Example 1.

[0062] Comparative Example 3

[0063] The procedure was carried out in accordance with Example 1, except that the synergistic promoter was only β-cyclodextrin, that is, 6.5 parts of β-cyclodextrin replaced 4 parts of β-cyclodextrin and 2.5 parts of lauryl betaine in the raw material components, and the other raw material components and preparation methods were the same as in Example 1.

[0064] Comparative Example 4

[0065] The method of Example 1 was followed, except that only sodium pyrophosphate was used as the stabilizer. Specifically, 3 parts of sodium pyrophosphate were used instead of 1.5 parts of sodium pyrophosphate and 1.5 parts of disodium ethylenediaminetetraacetate in Example 1. The other raw material components and preparation methods were the same as in Example 1.

[0066] Comparative Example 5

[0067] The preparation method was carried out in accordance with Example 1, except that in the preparation method, each raw material component was weighed according to the above proportions, 20 parts of deionized water were added to the reaction vessel, the stirring device was turned on, the stirring speed was set to 300 r / min, and the temperature was raised to 35 ℃. Under stirring conditions, 18 parts of N-methyldiethanolamine, 10 parts of N-(2-hydroxyethyl)ethylenediamine, 2.5 parts of triethanolamine, 28 parts of polyethylene glycol dimethyl ether, 12 parts of diethylene glycol butyl ether, 4 parts of β-cyclodextrin, 2.5 parts of lauryl betaine, 1.5 parts of sodium pyrophosphate, and 1.5 parts of disodium ethylenediaminetetraacetate were added to the deionized water and stirred for 40 min. Then, the pH of the system was adjusted to 9.2 using a dilute sodium hydroxide solution (mass concentration of 5%). Finally, the system was filtered through a 200-mesh filter to remove insoluble impurities and obtain the treatment agent.

[0068] Comparative Example 6

[0069] The preparation method was carried out in accordance with Example 1, except that in step S2, the functional alcohol ether component was added all at once instead of in batches, while the other raw material components and preparation methods were the same as in Example 1.

[0070] Comparative Example 7

[0071] The method was carried out in accordance with Example 1, except that in the preparation method, the temperature of the reactor was maintained at 41 °C in step S3.

[0072] Application Example 1

[0073] A method for treating electrolyte waste gas, the method comprising: the mass concentration of trimethylfluorosilane in the waste gas from a silicon-fluorine based electrolyte is 1000 mg / m³. 3 The mass concentration of dimethyl carbonate is 2000 mg / m³. 3 The exhaust gas is pretreated by filtering out large particulate solids, ensuring that the particle size is ≤1 μm. The exhaust gas temperature is 30 ℃ and the flow rate is 100 m³ / h. 3 / h; A two-stage series packed absorption tower is used, with polypropylene Pall ring packing and a packing layer height of 3 m. The pretreated waste gas is introduced into the bottom of the two-stage series absorption tower, and the silicon-fluorine electrolyte waste gas treatment agent prepared in Example 1 is sprayed from the top of the absorption tower for absorption treatment. The absorption temperature is 27 ℃, and the liquid-to-gas ratio of the silicon-fluorine electrolyte waste gas treatment agent to the silicon-fluorine electrolyte waste gas is 5 L / m 3 The residence time of the exhaust gas inside the tower is 8 seconds.

[0074] Application Examples 2-3 and Comparative Examples 1-7

[0075] The application was carried out in the manner described in Example 1, except that the silicon-fluorine electrolyte waste gas treatment agent prepared in Example 1 was replaced with the silicon-fluorine electrolyte waste gas treatment agent prepared in Examples 2-3 and the treatment agent prepared in Comparative Examples 1-7, respectively.

[0076] The absorption rates of trimethylfluorosilane and dimethyl carbonate in Application Examples 1-3 and Comparative Examples 1-7 were measured respectively, and the test results are shown in Table 1.

[0077] Table 1

[0078]

[0079] As shown in Table 1, the processing efficiency of Application Examples 1-3 is significantly better than that of Application Comparative Examples 1-7. Application Comparative Example 1 shows that the absorption rate of silicon fluorine compounds using a single amine drops sharply (to 78.3%). Application Comparative Examples 5-6 show that the feeding method significantly affects the processing efficiency; adding the alcohol ether component in batches helps to form a stable solvation layer, thereby improving the capture capacity of ester organic compounds.

[0080] Application Example 4

[0081] The deactivated treatment agent from Application Example 1 after waste gas treatment was transferred to a reactor, and a composite activator was added to the reactor. The composite activator was a mixture of sodium hydroxide solution (mass concentration of 10%) and ethanolamine solution (mass concentration of 15%) with a mass ratio of 3:1. The amount of composite activator added was 6.5% of the mass of the deactivated treatment agent. The mixture was stirred at 50 °C for 50 min, and then allowed to stand and separate into layers. The bottom precipitate was removed, and the clear liquid on the top layer was taken as the regenerated silicon-fluorine electrolyte waste gas treatment agent.

[0082] Application Example 5

[0083] The application is carried out in accordance with Example 4, except that the composite activator is a mixture of sodium hydroxide solution and ethanolamine solution in a mass ratio of 2:1.

[0084] Application Example 6

[0085] The application is carried out in accordance with Example 4, except that the composite activator is a mixture of sodium hydroxide solution and ethanolamine solution in a mass ratio of 5:1.

[0086] Application Example 7

[0087] The application was carried out in accordance with Example 4, except that the amount of composite activator added was 5% of the mass of the deactivation post-treatment agent.

[0088] Application Example 8

[0089] The application was carried out in accordance with Example 4, except that the amount of composite activator added was 8% of the mass of the deactivation post-treatment agent.

[0090] Application Example 9

[0091] The method of application example 4 is implemented, except that the treatment agent that was deactivated after exhaust gas treatment in application example 1 is replaced with the treatment agent that was deactivated after exhaust gas treatment in application example 2.

[0092] Application Example 10

[0093] The application was carried out in accordance with Application Example 4, except that the treatment agent that was deactivated after exhaust gas treatment in Application Example 1 was replaced with the treatment agent that was deactivated after exhaust gas treatment in Application Example 3.

[0094] Application Comparative Examples 8-14

[0095] The application was carried out in accordance with Application Example 4, except that the treatment agent that was deactivated after exhaust gas treatment in Application Example 1 was replaced with the treatment agents that were deactivated after exhaust gas treatment in Comparative Examples 1 to 7.

[0096] Test case

[0097] Activity retention rate: Freshly prepared silicon-fluorine electrolyte waste gas treatment agent (i.e., treatment agent without any absorption operation) was used. The waste gas was treated strictly according to the waste gas absorption conditions recorded in Application Example 1 (i.e., trimethylfluorosilane concentration of 1000 mg / m³, absorption temperature of 27 ℃, liquid-to-gas ratio of 5 L / m³, residence time of 8 s, etc.). After the system was running stably, the inlet and outlet gases were tested, and the initial absorption rate of trimethylfluorosilane was calculated and recorded as R0.

[0098] The above-mentioned electrolyte waste gas is continuously introduced into the absorption tower, and the outlet gas concentration is continuously monitored. When the absorption rate of trimethylfluorosilane drops to 80% or below, the batch of treatment agent is determined to be deactivated. The deactivated treatment agent is collected and regenerated according to the regeneration treatment method described in the corresponding application examples (such as application examples 4 to 10) or application comparative examples (such as application comparative examples 8 to 14) to obtain the first generation of regenerated treatment agent.

[0099] The obtained regenerated agent is then reintroduced into the absorption tower to repeat the "absorption-deactivation-regeneration" process. This cycle is repeated until the 10th regeneration treatment is completed. Using the obtained 10th generation regenerated agent, and after the system stabilizes, the absorption rate of trimethylfluorosilane at this point is measured and calculated, denoted as R. 10 Activity retention rate (%) = (R) 10 / R0) × 100%.

[0100] The activity retention rates of Application Examples 4-10 and Application Comparative Examples 8-14 were measured respectively, and the test results are shown in Table 2.

[0101] Table 2

[0102]

[0103] As shown in Table 2, the activity retention rates of Application Examples 4-10 of this application are all above 87%, with the best reaching 92.5%. However, the performance of Application Comparative Example 8 (single amine) and Application Comparative Example 12 (one-time addition) deteriorated significantly after 10 cycles, indicating that the hydrogen bond bridging mechanism of the complex amine and the ordered preparation process are the key to ensuring the regenerability of the treatment agent.

[0104] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application.

Claims

1. A silicon-fluorine based electrolyte waste gas treatment agent, characterized in that, The raw material components of the silicon-fluorine based electrolyte waste gas treatment agent, by mass, include: 25-35 parts of a complex amine component, 35-45 parts of a functional alcohol ether component, 5-8 parts of a synergistic promoter, 2-4 parts of a stabilizer, and 15-25 parts of deionized water. The complex amine component is a mixture of N-methyldiethanolamine, N-(2-hydroxyethyl)ethylenediamine, and triethanolamine; the functional alcohol ether component is a mixture of polyethylene glycol dimethyl ether and diethylene glycol butyl ether; the synergistic promoter is a mixture of β-cyclodextrin and lauryl betaine; and the stabilizer is a mixture of sodium pyrophosphate and disodium ethylenediaminetetraacetate.

2. The silicon-fluorine based electrolyte waste gas treatment agent according to claim 1, characterized in that, The raw material components of the silicon-fluorine based electrolyte waste gas treatment agent, by mass, include: 15-20 parts N-methyldiethanolamine, 8-12 parts N-(2-hydroxyethyl)ethylenediamine, 2-3 parts triethanolamine, 25-30 parts polyethylene glycol dimethyl ether, 10-15 parts diethylene glycol butyl ether, 3-5 parts β-cyclodextrin, 2-3 parts lauryl betaine, 1-2 parts sodium pyrophosphate, 1-2 parts disodium ethylenediaminetetraacetate, and 15-25 parts deionized water.

3. The silicon-fluorine based electrolyte waste gas treatment agent according to claim 2, characterized in that, The raw material components of the silicon-fluorine based electrolyte waste gas treatment agent, by mass, include: 18 parts N-methyldiethanolamine, 10 parts N-(2-hydroxyethyl)ethylenediamine, 2.5 parts triethanolamine, 28 parts polyethylene glycol dimethyl ether, 12 parts diethylene glycol butyl ether, 4 parts β-cyclodextrin, 2.5 parts lauryl betaine, 1.5 parts sodium pyrophosphate, 1.5 parts disodium ethylenediaminetetraacetate, and 20 parts deionized water.

4. A method for preparing the silicon-fluorine based electrolyte waste gas treatment agent according to any one of claims 1 to 3, characterized in that, The preparation method includes the following steps: S1. Weigh the raw material components of the silicon-fluorine electrolyte waste gas treatment agent according to the ratio, and add the stabilizer to deionized water at 35~45℃ and under stirring conditions to form a first mixing system. Then add the composite amine component to the first mixing system to form a second mixing system. S2. Add the functional alcohol ether component to the second mixing system in batches and mix them to form a third mixing system; S3. At 25~30℃, the synergistic promoter is added to the third mixing system and mixed. Then the pH is adjusted to 9.0~9.5, and finally filtered to obtain the silicon-fluorine electrolyte waste gas treatment agent.

5. The preparation method of the silicon-fluorine based electrolyte waste gas treatment agent according to claim 4, characterized in that, In step S1, the stabilizer is added to deionized water at 40-42°C and under stirring conditions for the first mixing. In step S3, the synergistic promoter is added to the third mixing system at 26~28°C for mixing.

6. A method for treating electrolyte waste gas, characterized in that, The method for treating electrolyte waste gas includes: passing the silicon-fluorine based electrolyte waste gas into an absorption tower for absorption treatment, wherein the absorbent used in the absorption tower is the silicon-fluorine based electrolyte waste gas treatment agent according to any one of claims 1 to 3.

7. The method for treating electrolyte waste gas according to claim 6, characterized in that, In the waste gas from the silane-fluorine electrolyte, the mass concentration of trimethylfluorosilane is 500~2000 mg / m³. 3 The mass concentration of dimethyl carbonate is 800~3000 mg / m³. 3 .

8. The method for treating electrolyte waste gas according to claim 6 or 7, characterized in that, The liquid-to-gas ratio of the fluorine-based electrolyte waste gas treatment agent to the fluorine-based electrolyte waste gas is 5~8 L / m³. 3 .

9. The method for treating electrolyte waste gas according to claim 6, characterized in that, The electrolyte waste gas treatment method further includes the regeneration treatment of the silicon-fluorine based electrolyte waste gas treatment agent. The regeneration treatment method includes: mixing the deactivated silicon-fluorine based electrolyte waste gas treatment agent with a composite activator, stirring at 45~55℃, then allowing it to stand and separate into layers, removing the precipitate, and taking the upper clear liquid. The upper clear liquid is the regenerated silicon-fluorine based electrolyte waste gas treatment agent. The composite activator is a mixture of sodium hydroxide solution and ethanolamine solution with a mass ratio of 2~5:

1.

10. The method for treating electrolyte waste gas according to claim 9, characterized in that, The mass ratio of the sodium hydroxide solution to the ethanolamine solution is 3:1; The amount of the composite activator added is 5-8% of the mass of the deactivated silicon-fluorine electrolyte waste gas treatment agent.

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