Method for preparing high-purity adamantyl trimethylammonium hydroxide and high-purity quaternary ammonium base prepared thereby

Abstract

The present invention relates to the technical field of production of high-purity quaternary ammonium bases, and provides a method for preparing high-purity adamantyl trimethylammonium hydroxide and a high-purity quaternary ammonium base prepared thereby. The method for preparing high-purity adamantyl trimethylammonium hydroxide comprises the following steps: S1, material preparation: adding adamantyl trimethylammonium chloride into water to obtain an aqueous solution, and then adding an adsorbent thereto to obtain a pretreatment solution, wherein the adsorbent contains stearate ions; S2 electrolysis: adding the pretreatment solution to a raw material chamber of an electrolytic cell for electrolysis, so that adamantyl trimethyl ammonium cations enter a cathode chamber through a cation membrane and combine with hydroxide ions generated by the cathode to form adamantyl trimethylammonium hydroxide, so as to obtain a quaternary ammonium base. The method for preparing high-purity adamantyl trimethylammonium hydroxide has the advantage of improving the quality of the quaternary ammonium base product.

Description

Preparation method of high-purity adamantyltrimethylammonium hydroxide and high-purity quaternary ammonium base prepared by the method TECHNICAL FIELD

[0001] The present application relates to the technical field of high-purity organic quaternary ammonium base production, in particular to a preparation method of high-purity adamantyltrimethylammonium hydroxide and high-purity quaternary ammonium base prepared by the method. BACKGROUND

[0002] Adamantyltrimethylammonium hydroxide is often used for synthesizing SSZ-13 molecular sieve. The SSZ-13 molecular sieve synthesized by using adamantyltrimethylammonium hydroxide has the advantages of large specific surface area and high crystallinity, and is used for SCR (diesel vehicle exhaust nitrogen oxide purification) reaction, which has the advantages of good hydrothermal stability and excellent catalytic effect, and is currently widely used in the field of SCR.

[0003] Adamantyltrimethylammonium hydroxide can also be used for battery electrolyte due to its excellent ion conductivity and chemical stability. The product purity is required to be higher when adamantyltrimethylammonium hydroxide is used for battery electrolyte, and the content of single metal ion is generally required to be lower than 100 ppb. The production methods of adamantyltrimethylammonium hydroxide mainly include ion exchange method, calcium hydroxide hydrolysis method and electrolysis method. In these methods, the product quality prepared by electrolysis method is better, but there is still a certain difference from the requirement of battery electrolyte. SUMMARY

[0004] In order to improve the quality of adamantyltrimethylammonium hydroxide, the present application provides a preparation method of high-purity adamantyltrimethylammonium hydroxide and high-purity quaternary ammonium base prepared by the method.

[0005] In the first aspect, the present application provides a preparation method of high-purity adamantyltrimethylammonium hydroxide, which adopts the following technical scheme:

[0006] The preparation method of high-purity adamantyltrimethylammonium hydroxide comprises the following steps:

[0007] S1: taking adamantyltrimethylammonium chloride, adding water to prepare an aqueous solution, and adding an adsorbent; a pretreated solution is prepared; the adsorbent contains stearate ions;

[0008] S2: adding the pretreated solution into a raw material chamber of an electrolytic cell, and through electrolysis, adamantyltrimethylammonium cations enter a cathode chamber through a cation membrane, combine with hydroxide ions generated by the cathode to form adamantyltrimethylammonium hydroxide, and quaternary ammonium base is prepared.

[0009] By adopting the technical scheme, in the electrolysis process, the adamantyl trimethyl ammonium cation enters the cathode chamber through the cation membrane and combines with the hydroxide ion generated in the cathode chamber to form adamantyl trimethyl ammonium hydroxide; by adding the adsorbent containing stearate in the pretreatment liquid, the metal ions in the adamantyl trimethyl ammonium chloride raw material are stabilized in the raw material chamber, the probability of the metal ions entering the product cavity through the cation membrane is reduced, the content of the metal ions in the product is reduced, and the product quality is improved.

[0010] Preferably, the concentration of the stearate ion in the raw material chamber is 20 ppm-100 ppm.

[0011] By adopting the technical scheme, if the concentration of the stearate ion is too low, the effect is not good; if the concentration of the stearate ion is too high, the effect is not good, and the effect is better by selecting a suitable concentration of stearic acid.

[0012] Preferably, the adsorbent is stearic acid or ammonium stearate.

[0013] By adopting the technical scheme, the stearic acid or ammonium stearate is used as the adsorbent, which helps to avoid the introduction of metal ions; after the electrolysis of the quaternary ammonium base is completed, the ammonium ions introduced in the ammonium stearate are removed through the concentration and ammonium removal step, which helps to avoid the introduction of new impurities.

[0014] Preferably, the adsorbent is stearic acid.

[0015] By adopting the technical scheme, the inventor has found in practice that the stearic acid is the best adsorbent for stabilizing metal ions, which can stabilize the metal ions in the raw material cavity, helps to avoid the metal ions entering the cathode chamber (generally the product cavity) through the cation membrane, helps to reduce the impurities in the product, and helps to improve the product quality.

[0016] Preferably, the electrolytic tank comprises an anode chamber, a raw material chamber and a cathode chamber which are sequentially adjacent; the anode chamber is provided with an anode plate, the cathode chamber is provided with a cathode plate, and the anode plate and the cathode plate are connected through a power supply; the anode chamber and the raw material chamber are communicated through a cation membrane, and the raw material chamber and the cathode chamber are communicated through a cation membrane.

[0017] By adopting the technical scheme, the three-chamber two-membrane method is used to produce high-purity adamantyltrimethylammonium hydroxide, the adsorbent containing stearate ions is used to fix metal ions in the raw material chamber; a part of the stearate ions enter the anode chamber through the anion membrane, and the metal ions in the anode chamber are fixed in the anode chamber. Generally, a small amount (generally less than 4%) of metal ions in the anode chamber will enter the raw material chamber through the anion membrane. The stearic acid entering the anode chamber through the anion membrane can reduce the probability of metal ions in the anode chamber entering the raw material chamber, and help to improve the product quality.

[0018] Preferably, the raw material chamber of the step S2 contains ethanol.

[0019] By adopting the technical scheme, the inventors have found in practice that the addition of ethanol in the raw material chamber has a certain synergistic effect with stearic acid, which can further reduce the impurity content in the product and improve the product quality.

[0020] Preferably, the weight concentration ratio of ethanol to stearate ions in the raw material chamber of the step S2 is 1-5. More preferably, the weight concentration ratio of ethanol to stearate ions in the raw material chamber of the step S2 is 2-3.5.

[0021] By adopting the technical scheme, the inventors have found in practice that the ratio of ethanol to stearic acid needs to be within a suitable range for better effect, and too high or too low will affect the effect.

[0022] Preferably, the mass concentration of adamantyltrimethylammonium chloride in the raw material chamber of the step S2 is 8-15%.

[0023] By adopting the technical scheme, the mass concentration of adamantyltrimethylammonium chloride in the raw material chamber also has a certain influence on the metal ion content of the final product.

[0024] In a second aspect, the application provides a high-purity quaternary ammonium base, which is prepared by the above method.

[0025] By adopting the technical scheme, the adamantyltrimethylammonium hydroxide prepared by the method disclosed in the application can help to reduce the metal ion content and improve the product quality.

[0026] In summary, the application has at least one of the following beneficial technical effects:

[0027] The application uses electrolysis to produce adamantyltrimethylammonium hydroxide, and adds an adsorbent containing stearate in the pretreatment liquid to fix metal ions in the raw material chamber, which can help to reduce the probability of metal ions entering the cathode chamber (product chamber) through the cation membrane and improve the product quality.

[0028] In the electrolysis process, ethanol and stearate ions are added in the raw material chamber, and the ethanol and stearate ions have a synergistic effect, which helps to reduce the content of metal ions in the product and improve the product quality.

[0029] In the present application, the ratio of ethanol and stearate ions has a certain influence on the metal ions in the product, and by controlling the ratio of ethanol and stearate ions, the product quality can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 is a schematic diagram of the electrolytic cell structure used in the present application.

[0031] Reference signs: 1, anode chamber; 2, raw material chamber; 3, cathode chamber; 4, anode plate; 5, cathode plate; 6, anion membrane; 7, cation membrane. DETAILED DESCRIPTION

[0032] In the process of preparing adamantyl trimethyl ammonium hydroxide by electrolysis, generally adamantyl trimethyl ammonium chloride is used as raw material, and adamantyl trimethyl ammonium hydroxide is prepared by electrolysis. In the present application, adamantyl trimethyl ammonium chloride is 1-adamantyl trimethyl ammonium chloride, and adamantyl trimethyl ammonium hydroxide is 1-adamantyl trimethyl ammonium hydroxide. The inventors found in practice that chloride ions have certain corrosive properties, and the metal ion content of the produced adamantyl trimethyl ammonium hydroxide is high.

[0033] Based on the above technical background, the present application proposes a technical solution, which adds a small amount of stearic acid and ethanol in the raw material chamber of the electrolysis machine, and the two together can significantly reduce the content of metal ions in the product, which helps to improve the product quality. The synergistic effect of ethanol and stearic acid helps to reduce the content of metal ions, and the inventors found in practice that the use of ethanol and stearic acid also helps to reduce the content of halogen ions in the product.

[0034] During the electrolysis process, stearate ions can pass through the anion membrane into the cathode chamber, but ethanol cannot pass through the anion membrane and the cation membrane; therefore, stearate ions are added to the adamantyltrimethylammonium chloride aqueous solution, and as the electrolysis proceeds, adamantyltrimethylammonium cations enter the cathode chamber, and the concentration of adamantyltrimethylammonium cations in the raw material chamber decreases. By adding the pretreatment solution to the raw material chamber, the concentration of adamantyltrimethylammonium chloride in the raw material chamber is maintained within the required range, and at the same time, the concentration of stearate ions is maintained within the appropriate range. Ethanol is not added to the pretreatment solution, but is directly added to the raw material chamber, so that the ratio of ethanol to stearic acid is maintained within a reasonable range; in actual operation, the loss of ethanol is small, and a certain amount of ethanol is added when the electrolysis machine is started, and the amount of subsequent ethanol added is small. In actual production, as the electrolysis time increases, a small amount of solid material such as precipitate or flocculent material adheres to the inner wall of the raw material chamber; therefore, the electrolysis machine needs to be cleaned regularly, such as once a month, which will help to maintain the stability of product quality.

[0035] The specific embodiments are described below.

[0036] The water used in the following examples is deionized water with a conductivity of not more than 20 μs / cm. The power source for the electrolysis process is a direct current power source. The mass concentration of adamantyltrimethylammonium chloride in the raw material chamber during the electrolysis process is not more than 15%, and is preferably 8-15%. During the electrolysis process, the concentration of chloride ions in the raw material chamber is titrated with silver nitrate, and the concentration of adamantyltrimethylammonium chloride is measured by conversion, and the concentration of adamantyltrimethylammonium chloride in the raw material chamber is tracked during the electrolysis process; according to the change in the concentration of adamantyltrimethylammonium chloride in the raw material chamber, the pretreatment solution is added to the raw material chamber during the electrolysis process to maintain the mass concentration of adamantyltrimethylammonium chloride in the raw material chamber within the range of 8-15%. The concentration of adamantyltrimethylammonium chloride in the pretreatment solution can be prepared according to the needs, and in the examples, the concentration of adamantyltrimethylammonium chloride in the pretreatment solution is 36%, and water is added to the raw material chamber at the start to maintain the concentration of adamantyltrimethylammonium chloride in the raw material chamber within the range of 8-15%. In the examples, the concentration of stearate ions in the pretreatment solution is 60 ppm-300 ppm, and the water in the raw material chamber controls the concentration of stearate ions in the raw material chamber within the required range, and the concentration of stearate ions in the raw material chamber is adjusted to the required value by changing the concentration of stearate ions in the pretreatment solution. The concentration of stearate ions is detected by ion chromatography, the concentration of ethanol is detected by headspace chromatography, and the concentration of metal ions is detected by ICP-MS.

[0037] The same set of electrolysis equipment is used in the following examples. Before starting the power source to begin electrolysis, the electrolysis tank contains water.

[0038] The application is further described in detail below with reference to the accompanying drawings. Examples

[0039] Example 1: A method for preparing high-purity adamantyltrimethylammonium hydroxide, comprising the following steps:

[0040] S1: Take 5 kg of adamantyltrimethylammonium chloride, add pure water to prepare an adamantyltrimethylammonium chloride aqueous solution with a mass concentration of 36%, stir, and add 0.83 g of stearic acid to prepare a pretreatment solution with a stearate ion concentration of 60 ppm.

[0041] S2: Take the adamantyltrimethylammonium chloride prepared in step S1, add it to the raw material chamber 2 of the electrolytic cell, and dilute it with water to a mass concentration of 12% adamantyltrimethylammonium chloride and a stearate ion concentration of about 20 ppm in the raw material chamber 2. The electrolytic cell comprises, in sequence, an anode chamber 1, a raw material chamber 2, and a cathode chamber 3. The anode chamber 1 is equipped with an anode plate 4, and the cathode chamber 3 is equipped with a cathode plate 5. The anode plate 4 and the cathode plate 5 are connected by a power source. The anode chamber 1 and the raw material chamber 2 are connected by a negative ion membrane 6, and the raw material chamber 2 and the cathode chamber 3 are connected by a positive ion membrane 7. Water is added to the anode chamber 1 and the cathode chamber 3 in step S2. In step S2, the adamantyltrimethylammonium chloride aqueous solution is first added to the raw material chamber 2. Through electrolysis, adamantyltrimethylammonium cations pass through the positive ion membrane 7 into the cathode chamber 3 and combine with the hydroxide ions generated at the cathode to form adamantyltrimethylammonium hydroxide.

[0042] During the electrolysis process, the materials in the anode chamber 1, the raw material chamber 2, and the cathode chamber 3 are circulated by circulating pumps. The circulation flow rates of the materials in the anode chamber 1 and the cathode chamber 3 are both 80 ml / min, and the circulation flow rate of the material in the raw material chamber 2 is 150 ml / min. According to the concentration changes of adamantyltrimethylammonium chloride in the raw material chamber 2, adamantyltrimethylammonium chloride aqueous solution is added to the raw material chamber 2 during the electrolysis process to maintain the adamantyltrimethylammonium chloride concentration in the raw material chamber 2 at about 12% and the stearate ion concentration at about 20 ppm. After 24 hours of electrolysis, the concentration of adamantyltrimethylammonium hydroxide product in the cathode chamber 3 increases to about 25%. Water is added to the cathode chamber 3 to maintain the concentration at about 25%. Every 8 hours, 1 kg of product is discharged from the cathode chamber 3. After 48 hours of electrolysis, the metal ion content of the product generated after 48 hours of electrolysis is detected. Example

[0043] The difference between Example 2 and Example 1 is that 150 ppm of ethanol is added to the raw material chamber in step S2 of Example 2. During the electrolysis process, sample is taken every 4 hours to detect the ethanol content in the raw material chamber using headspace chromatography. According to the detection results, ethanol is added to maintain the ethanol content in the raw material chamber at about 150 ppm. The other aspects remain the same as in Example 1. Example

[0044] Example 3 is different from Example 2 in that the stearate ion content in the raw material chamber of Example 3 is 100 ppm, the ethanol content is 500 ppm, and the rest is consistent with Example 2. Example

[0045] Example 4 is different from Example 3 in that the stearate ion content in the raw material chamber of Example 4 is 30 ppm, the ethanol content is 30 ppm, and the rest is consistent with Example 3. Example

[0046] Example 5 is different from Example 4 in that the stearate ion content in the raw material chamber of Example 5 is 40 ppm, the ethanol content is 140 ppm, and the rest is consistent with Example 3.

[0047] Examples 6-10

[0048] Examples 6-10 are different from Example 5 in that the stearate ion and ethanol concentrations in the raw material chamber of Examples 6-10 are different, and the rest is consistent with Example 5. The concentrations of each component in the raw material chamber of Examples 6-10 in Step S2 are shown in Table 1.

[0049] Table 1: Molar ratio of each raw material in Examples 6-10

[0050] Comparative Example 1

[0051] Comparative Example 1 is different from Example 1 in that no stearic acid is added in Comparative Example 1, and the rest is consistent with Example 1.

[0052] Table 2: Comparison of metal ion content in the product after electrolysis for 48 h

[0053] Comparative Example 1 uses a conventional electrolysis method to prepare adamantyltrimethylammonium hydroxide, and the product obtained has a sodium ion content exceeding 100 ppb and a potassium ion content exceeding 150 ppb, with many impurities and poor product quality. By comparing the experimental results of Comparative Example 1 and Example 1, it can be seen that during the preparation of adamantyltrimethylammonium hydroxide, the addition of an adsorbent containing stearate ions has a certain adsorption effect on metal ions, making metal ions tend to be fixed in the raw material chamber, reducing the probability of metal ions passing through the cation membrane into the product chamber, and being beneficial to reducing the impurity content in the product and improving the product quality. In particular, the reduction of potassium ions is obvious, and the potassium ion content is reduced by more than 120 ppb.

[0054] Comparing the experimental results of Comparative Example 1 and Example 2, the metal ion content is further reduced and the chloride ion content is reduced in Example 2 in which ethanol and stearic acid are simultaneously added to the raw material chamber. In Example 3, the stearic acid content is about 100 ppm and the ratio of ethanol to stearic acid is 5, and the metal ion content is further reduced. In Example 4, the stearic acid content is about 30 ppm and the ratio of ethanol to stearic acid is 1, and the metal ion content is somewhat reduced.

[0055] Comparing the experimental results of Comparative Examples 3-4 and Example 5, the metal ion content of the product prepared in Example 5 is significantly reduced, the potassium ion and calcium ion are both less than 10 ppb, and the product quality is high, because the stearic acid content is appropriate and the ratio of ethanol to stearic acid is in the optimal range. In Examples 6-7, the stearic acid content is appropriate, but the ratio of ethanol to stearic acid is not appropriate, and the metal ion content is relatively high. In Examples 8-10, the stearic acid content is appropriate and the ratio of ethanol to stearic acid is appropriate, and the metal ion content and chloride ion content of the product prepared are relatively low, and the product quality is high.

[0056] The examples of the specific embodiments are the preferred embodiments of the present application, and do not limit the protection scope of the present application, and therefore: any equivalent changes made according to the structure, shape, principle of the present application should be covered within the protection scope of the present application.

Claims

1. A process for the preparation of high purity adamantyltrimethylammonium hydroxide, characterized in that, The method comprises the following steps: S1: preparing a pretreatment solution by adding adamantyl trimethyl ammonium chloride into water and adding an adsorbent, wherein the adsorbent contains stearate ions; S2: adding the pretreatment solution into a raw material chamber of an electrolytic cell, and through electrolysis, the adamantyl trimethyl ammonium cation enters the cathode chamber through the cation membrane, combines with the hydroxide ions generated by the cathode to form adamantyl trimethyl hydroxide, and a quaternary ammonium base is prepared.

2. The method for preparing high-purity adamantyltrimethylammonium hydroxide according to claim 1, characterized in that: The concentration of stearate ions in the raw material chamber is 20-100 ppm.

3. The method for preparing high-purity adamantyltrimethylammonium hydroxide according to claim 1, characterized in that: The adsorbent is stearic acid or ammonium stearate.

4. The method for preparing high-purity adamantyltrimethylammonium hydroxide according to claim 3, characterized in that: The adsorbent is stearic acid.

5. The method of claim 1, wherein the high purity adamantane trimethyl ammonium hydroxide is prepared by the process comprising: a) reacting adamantane trimethyl ammonium chloride with sodium hydroxide to form adamantane trimethyl ammonium hydroxide; and b) purifying the adamantane trimethyl ammonium hydroxide. The electrolytic cell comprises an anode chamber (1), a raw material chamber (2) and a cathode chamber (3) arranged in sequence; an anode plate (4) is installed in the anode chamber (1), a cathode plate (5) is installed in the cathode chamber (3), the anode plate (4) is connected with the cathode plate (5) through a power supply; the anode chamber (1) and the raw material chamber (2) are communicated through a cation membrane (6), and the raw material chamber (2) and the cathode chamber (3) are communicated through an anion membrane (7).

6. The method for preparing high-purity adamantyltrimethylammonium hydroxide according to claim 1, characterized in that: The raw material chamber of step S2 contains ethanol.

7. The method for preparing high-purity adamantyltrimethylammonium hydroxide according to claim 6, characterized in that: The weight concentration ratio of ethanol to stearate ions in the raw material chamber of step S2 is 1-5.

8. The method of claim 1, wherein the high purity adamantane trimethyl ammonium hydroxide is prepared by the process comprising: a) reacting adamantane trimethyl ammonium chloride with sodium hydroxide to form adamantane trimethyl ammonium hydroxide; and b) purifying the adamantane trimethyl ammonium hydroxide. The mass concentration of adamantyl trimethyl ammonium chloride in the raw material chamber of step S2 is 8-15%.

9. A high purity quaternary ammonium base characterized by: The adamantyl trimethyl hydroxide is prepared by the method of any one of claims 1-8.

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