Method for producing purified, aqueous hydrogen peroxide solution

Abstract

One embodiment of the present invention is a method for producing a purified, aqueous hydrogen peroxide solution, the method comprising: a step in which an aqueous hydrogen peroxide solution is passed through a first reverse osmosis membrane system; a step in which an additive is added to the aqueous hydrogen peroxide solution which has passed through the first reverse osmosis membrane system, the additive including a composite salt containing a sulfuric acid ion; and a step in which the aqueous hydrogen peroxide solution to which the additive has been added is passed through a second reverse osmosis membrane system.

Description

How to make purified hydrogen peroxide

[0001] The present invention relates to a method for producing purified aqueous hydrogen peroxide.

[0002] Hydrogen peroxide has oxidizing power and strong bleaching and disinfecting properties, and is therefore used as a bleach for paper, pulp, textiles, etc., a disinfectant, a food additive, etc. Furthermore, the amount of hydrogen peroxide used is increasing in the electronics industry for cleaning the surfaces of semiconductor substrates, chemical polishing of copper, tin, and other copper alloy surfaces, and etching of electronic circuits. High purity is required for hydrogen peroxide used in the electronics industry and as a food additive, and demand for high-purity hydrogen peroxide is on the rise. Common methods for purifying hydrogen peroxide include those using distillation, cyclones, adsorption resins, ion exchange resins, and reverse osmosis membranes.

[0003] Patent Document 1 discloses a method for purifying aqueous hydrogen peroxide, which includes the steps of treating aqueous hydrogen peroxide with a first reverse osmosis membrane system, adding a stabilizer to the aqueous hydrogen peroxide, treating the aqueous hydrogen peroxide with an adsorption resin, and treating the aqueous hydrogen peroxide with an ion exchange resin, wherein the stabilizer is selected from phosphate, pyrophosphate, phosphoric acid, and combinations thereof.

[0004] Patent No. 7419443

[0005] Cationic impurities such as sodium contained in hydrogen peroxide solution are known to affect the quality of products when hydrogen peroxide solution is used, such as in semiconductor manufacturing processes. Therefore, it is necessary to remove as many cationic impurities (especially sodium) as possible from hydrogen peroxide solution.

[0006] Therefore, an object of the present invention is to provide a method for producing aqueous hydrogen peroxide using a first reverse osmosis membrane system and a second reverse osmosis membrane system, which reduces the sodium component in aqueous hydrogen peroxide that passes through the second reverse osmosis membrane system.

[0007] The present invention includes the following aspects. [1] A method for producing purified hydrogen peroxide solution, comprising the steps of passing hydrogen peroxide solution through a first reverse osmosis membrane system, adding an additive to the hydrogen peroxide solution that has passed through the first reverse osmosis membrane system, the additive including a double salt containing sulfate ions, and passing the hydrogen peroxide solution to which the additive has been added through a second reverse osmosis membrane system. [2] The method according to [1] above, wherein the additive is added in an amount of 0.1 to 50 ppm to the hydrogen peroxide solution that has passed through the first reverse osmosis membrane system. [3] The method according to [1] or [2] above, wherein the additive further includes phosphoric acid. [4] The method according to any one of [1] to [3] above, wherein the concentration of sodium components (ppm) in the hydrogen peroxide solution that has passed through the second reverse osmosis membrane system is 70% or more lower than the concentration of sodium components (ppm) in the hydrogen peroxide solution that has passed through the first reverse osmosis membrane system and before the additive is added. [5] The method according to any one of [1] to [4] above, further comprising passing the hydrogen peroxide solution that has passed through the second reverse osmosis membrane system through an adsorption resin tower, a cation exchange resin tower, an anion exchange resin tower, a mixed bed resin tower, or a combination thereof. [6] The method according to any one of [1] to [5] above, wherein the double salt containing sulfate ions is potassium alum, ammonium alum, chromium alum, iron alum, or a combination thereof. [7] The method according to any one of [1] to [6] above, wherein the double salt containing sulfate ions is potassium alum.

[0008] The production method of the present invention can reduce the sodium content in hydrogen peroxide solution that has passed through a reverse osmosis membrane system. Furthermore, in conventional methods in which no additives or only phosphoric acid is added to hydrogen peroxide solution, the rejection rate of the sodium component (the sodium component reduction effect) by the reverse osmosis membrane system gradually decreases over the usage time of the reverse osmosis membrane system through which the hydrogen peroxide solution passes. However, the production method of the present invention can suppress the decrease in sodium rejection rate over the usage time of the reverse osmosis membrane system.

[0009] A method for producing purified hydrogen peroxide according to one embodiment of the present invention includes the steps of passing hydrogen peroxide through a first reverse osmosis membrane system, adding an additive to the hydrogen peroxide that has passed through the first reverse osmosis membrane system, where the additive includes a double salt containing sulfate ions, and passing the hydrogen peroxide to which the additive has been added through a second reverse osmosis membrane system.

[0010] Examples of double salts containing sulfate ions include alums. Specific examples of double salts containing sulfate ions include potassium alum, ammonium alum, chromium alum, iron alum, and combinations thereof. The preferred double salt containing sulfate ions is potassium alum. However, sodium alum itself can be a source of sodium contamination, so its use as a double salt containing sulfate ions is undesirable.

[0011] Here, "purified hydrogen peroxide solution" refers to hydrogen peroxide solution that has been added with an additive, such as a sulfate-containing double salt, and passed through a reverse osmosis membrane system, with the sodium concentration (ppm) reduced by 70% or more compared to the hydrogen peroxide solution before passing through the reverse osmosis membrane system and before the additive was added. Note that the term "passing through" is synonymous with "passing through."

[0012] The first and second reverse osmosis membrane systems each include at least one reverse osmosis membrane (RO membrane). When each reverse osmosis membrane system includes two or more reverse osmosis membranes, they may be connected in parallel or in series. The first and second reverse osmosis membrane systems may each have the same configuration or different configurations.

[0013] The reverse osmosis membrane (RO membrane) may be any membrane capable of removing impurities from hydrogen peroxide solution. Examples of reverse osmosis membranes include flat membranes, pleated membranes, spiral membranes, tube membranes, rod membranes, fine tube membranes, spaghetti membranes, hollow fiber membranes, and combinations thereof. Examples of materials for reverse osmosis membranes include polyethyleneimine condensates, cellulose acetate, modified polyacrylonitrile, polybenzimidapyrone, polyetheramide, cellulose triacetate, polyamidocarboxylic acid, crosslinked polyethers, crosslinked polyamides, polyimides, polybenzimidazole, sulfonated phenylene oxide, polypiperazine amide, polyethyleneimine tallol, enediisocyanate, polyethyleneisocyanic acid chloride, sulfonated polyfurfuryl alcohol, sulfonated polysulfone, polyetherurea, polyvinyl alcohol, polysulfone, polyamide polyvinyl alcohol, sulfonated polyethersulfone, and polyamides. The reverse osmosis membrane may be an asymmetric membrane or a composite membrane. For example, the reverse osmosis membrane may be a composite membrane made of polyamide.

[0014] The first reverse osmosis membrane system treats crude hydrogen peroxide solution with a reverse osmosis membrane. The crude hydrogen peroxide solution may be produced by any method, including, for example, an anthraquinone method, an alcohol oxidation method, an oxidation-reduction method, a direct method (direct oxidation method), and an electrolysis method. The concentration of hydrogen peroxide contained in the crude hydrogen peroxide solution is not particularly limited, and may be, for example, 20 to 99% by mass, 20 to 90% by mass, 30 to 90% by mass, 30 to 80% by mass, 35 to 90% by mass, 35 to 80% by mass, 35 to 70% by mass, 40 to 90% by mass, 40 to 80% by mass, 40 to 70% by mass, or 40 to 60% by mass.

[0015] The crude hydrogen peroxide solution may contain either or both organic impurities and inorganic impurities. In the anthraquinone method, examples of organic impurities include the working solution composition and its degraded products. Degraded products include nonpolar solvent degraded products (e.g., benzaldehydes, benzoic acids, phenols, benzyl alcohols, etc.), polar solvent degraded products (e.g., 2-ethylhexanol, 2-ethylhexanal, etc.), and anthraquinone degraded products (e.g., anthrone, oxyanthrone, tetrahydrooxyanthrone, anthraquinone epoxide, tetrahydroanthraquinone epoxide, etc.). Examples of inorganic impurities include copper, zinc, chromium, palladium, rhodium, ruthenium, platinum, iron, nickel, aluminum, sodium, potassium, calcium, chlorine, sulfur, silica, boron, etc.

[0016] The second reverse osmosis membrane system further treats the hydrogen peroxide solution treated in the first reverse osmosis membrane system through a reverse osmosis membrane. The additive added between the first and second reverse osmosis membrane systems and the action of the second reverse osmosis membrane system remove sodium components from the hydrogen peroxide solution passing through the second reverse osmosis membrane system. While the components removed by the second reverse osmosis membrane system are not limited to sodium components, this embodiment focuses on the sodium components removed by the second reverse osmosis membrane system.

[0017] The treatment pressure applied to the reverse osmosis membranes when passing the hydrogen peroxide solution through the first reverse osmosis membrane system and the second reverse osmosis membrane system may be within the range tolerated by the reverse osmosis membrane. For example, the treatment pressure may be 0.1 to 5 MPa, 0.1 to 4 MPa, 0.1 to 3 MPa, 0.1 to 2 MPa, or 0.1 to 1 MPa. The treatment temperature in the first reverse osmosis membrane system and the second reverse osmosis membrane system is desirably one that does not cause excessive decomposition of hydrogen peroxide, and is preferably in the range of −20 to 40° C., more preferably 5 to 25° C. The first reverse osmosis membrane system and the second reverse osmosis membrane system may be equipped with a pressurizing device that controls the pressure of the hydrogen peroxide solution, a pumping device that controls the flow rate of the hydrogen peroxide solution, a temperature control device that controls the temperature of the hydrogen peroxide solution, and the like.

[0018] The flow rate (volume / time) of the hydrogen peroxide solution passing through the first reverse osmosis membrane system and the second reverse osmosis membrane system per unit area may be the same or different. The flow rate of the hydrogen peroxide solution is adjusted appropriately taking into consideration the material, cross-sectional area, density, and passage length of the reverse osmosis membrane. For example, the flow rate of the hydrogen peroxide solution per unit area of ​​the reverse osmosis membrane (0.0044 m for the area of ​​a flat sheet membrane with a diameter of 75 mm) is ２ The flow rate of the hydrogen peroxide solution in the second reverse osmosis membrane system may be, but is not limited to, 0.1 to 100 ml / min, 0.1 to 50 ml / min, 0.1 to 30 ml / min, 0.1 to 20 ml / min, 0.1 to 10 ml / min, 0.1 to 8 ml / min, 0.1 to 5 ml / min, 0.1 to 3 ml / min, 0.1 to 1 ml / min, etc. A relatively low flow rate of the hydrogen peroxide solution passing through the second reverse osmosis membrane system can further improve the effect of reducing the sodium component.

[0019] The first reverse osmosis membrane system and the second reverse osmosis membrane system are connected by a flow path through which hydrogen peroxide passes. An additive containing a double salt containing sulfate ions is added to the hydrogen peroxide before the hydrogen peroxide that has passed through the first reverse osmosis membrane system enters the second reverse osmosis membrane system. The additive containing the double salt containing sulfate ions is added in an amount of 0.1 to 50 ppm, 0.1 to 40 ppm, 0.1 to 30 ppm, 0.1 to 20 ppm, 0.1 to 15 ppm, 0.1 to 12 ppm, 0.1 to 10 ppm, 0.1 to 8 ppm, 0.1 to 6 ppm, 0.1 to 5 ppm, 0.2 to 50 ppm, 0.2 to 40 ppm, 0.2 to 30 ppm, 0.2 to 20 ppm, or 0.3 to 15 ppm. ppm, 0.2 to 15 ppm, 0.2 to 12 ppm, 0.2 to 10 ppm, 0.2 to 8 ppm, 0.2 to 6 ppm, 0.2 to 5 ppm, 0.4 to 50 ppm, 0.4 to 40 ppm, 0.4 to 30 ppm, 0.4 to 20 ppm, 0.4 to 15 ppm, 0.4 to 12 ppm, 0.4 to 10 ppm, 0.4 to 8 ppm, 0.4 to 6 ppm, or 0.4 to 5 ppm. In this specification, ppm represents ppm by mass.

[0020] When the additive is only a double salt containing sulfate ions, the amount of the double salt containing sulfate ions added is 0.1 to 50 ppm, 0.1 to 40 ppm, 0.1 to 30 ppm, 0.1 to 20 ppm, 0.1 to 15 ppm, 0.1 to 12 ppm, 0.1 to 10 ppm, 0.1 to 8 ppm, 0.1 to 6 ppm, 0.1 to 5 ppm, 0.2 to 50 ppm, 0.2 to 40 ppm, 0.2 to 30 ppm relative to the hydrogen peroxide solution. , 0.2 to 20 ppm, 0.2 to 15 ppm, 0.2 to 12 ppm, 0.2 to 10 ppm, 0.2 to 8 ppm, 0.2 to 6 ppm, 0.2 to 5 ppm, 0.4 to 50 ppm, 0.4 to 40 ppm, 0.4 to 30 ppm, 0.4 to 20 ppm, 0.4 to 15 ppm, 0.4 to 12 ppm, 0.4 to 10 ppm, 0.4 to 8 ppm, 0.4 to 6 ppm, or 0.4 to 5 ppm.

[0021] The additive may contain phosphoric acid in addition to a double salt containing sulfate ions.

[0022] The hydrogen peroxide solution that has passed through the second reverse osmosis membrane system passes through an adsorption resin tower, a cation exchange resin tower, an anion exchange resin tower, and a mixed bed resin tower, all of which are connected by flow paths, to further remove impurities, ultimately producing high-purity hydrogen peroxide solution. The adsorption resin removes organic impurities, the cation exchange resin removes cationic components (sodium, calcium, and heavy metals such as iron and chromium) from the hydrogen peroxide solution, and the anion exchange resin tower primarily removes anionic components (chlorine, nitrate, etc.) from the hydrogen peroxide solution. The mixed bed resin tower functions as both a cation exchange resin and an anion exchange resin. The purification process following the second reverse osmosis membrane system may use an adsorption resin tower, a cation exchange resin tower, an anion exchange resin tower, a mixed bed resin tower, or any combination thereof, depending on the purity of the final hydrogen peroxide solution, the types of impurities that may be contained, etc.

[0023] In the method for producing purified hydrogen peroxide according to this embodiment, the concentration of the sodium component in the hydrogen peroxide solution that has passed through the second reverse osmosis membrane system can be reduced by 70% or more, 75% or more, 79% or more, 80% or more, 85% or more, 90% or more, 95% or more, or 99% or more compared to the hydrogen peroxide solution that has passed through the first reverse osmosis membrane system and before the addition of the additive. Furthermore, because the sodium component in the hydrogen peroxide solution after treatment with the second reverse osmosis membrane system is largely removed, the load on subsequent cation exchange resins and the like can be reduced, enabling longer life for the cation exchange resins and reduced costs.

[0024] In the examples of the present invention, hydrogen peroxide solution containing an additive containing potassium alum as a double salt containing sulfate ions was passed through a reverse osmosis membrane to confirm the effect of reducing the sodium content in the hydrogen peroxide solution. Note that all of the following examples and comparative examples were carried out at room temperature (20°C).

[0025] Preparation Example 1 0.8 ppm of potassium alum dodecahydrate (0.44 ppm of potassium alum in anhydrous equivalent) was added to and dissolved in 45% hydrogen peroxide solution that had been purified to a certain level by passing it through a reverse osmosis membrane (first reverse osmosis membrane system), thereby preparing hydrogen peroxide solution containing added potassium alum.

[0026] Example 1: For the reverse osmosis membrane purification, a Tritec spin flow cell manufactured by Tritec Corporation and a reverse osmosis membrane SWC5 flat sheet membrane manufactured by Nitto Denko Base Material Corporation were used. A 75 mm diameter SWC5 flat sheet membrane was incorporated into the Tritec spin flow cell to prepare the reverse osmosis membrane device (second reverse osmosis membrane system) used in this example. Pre-test cleaning of the reverse osmosis membrane device was performed by passing ultrapure water through it for one hour. Next, the hydrogen peroxide solution containing potassium alum from Preparation Example 1 was passed through the reverse osmosis membrane device for one hour to replace the ultrapure water in the reverse osmosis membrane device with hydrogen peroxide. The flow rates of the membrane permeate and the concentrated solution passing through the reverse osmosis membrane device were then adjusted to be equal, and the hydrogen peroxide solution containing potassium alum from Preparation Example 1 was passed through the reverse osmosis membrane device at a feed flow rate of 3.0 ml / min (time t = 0). The membrane permeate passing through the reverse osmosis membrane device was then pooled and sampled every hour. The metal content of each sample was analyzed by inductively coupled plasma atomic emission spectroscopy (ICP-AES) using a Thermo Scientific iCAP 6200 DuoView system. Compared to the hydrogen peroxide solution purified through the reverse osmosis membrane (first reverse osmosis membrane system) and before the addition of potassium alum, the sodium content was reduced by more than 99% in the samples stored for 0-1 hour (t = 0-1 hour), 1-2 hours (t = 1-2 hours), and 2-3 hours (t = 2-3 hours). In other words, the addition of potassium alum to the hydrogen peroxide solution increased the sodium rejection rate by the reverse osmosis membrane system to more than 99%, and this rejection rate did not decrease over time (at least from t = 0 to 3 hours) (Table 1). Here, the rejection rate (%) of the sodium component is calculated as 100 (1 - (concentration of the sodium component in the hydrogen peroxide solution after the addition of potassium alum and after passing through the reverse osmosis membrane device / concentration of the sodium component in the hydrogen peroxide solution before the addition of potassium alum and before passing through the reverse osmosis membrane device)).

[0027] (Preparation Example 2) 0.4 ppm of phosphoric acid and 0.8 ppm of potassium alum dodecahydrate (0.44 ppm of potassium alum in anhydrous equivalent) were added to 45% hydrogen peroxide solution that had been purified to a certain level by passing it through the same reverse osmosis membrane as in Preparation Example 1, and dissolved to prepare hydrogen peroxide solution containing added phosphoric acid and potassium alum.

[0028] Example 2 The same procedure as in Example 1 was carried out, except that the hydrogen peroxide solution prepared in Preparation Example 2 was used instead of the hydrogen peroxide solution containing potassium alum used in Example 1. The permeate solution passing through the reverse osmosis membrane device was pooled and sampled every hour, and the metal components in each sample were analyzed by the same ICP-AES. As in Example 1, the rejection rate of sodium components by the reverse osmosis membrane device was maintained at a relatively high level (79% or higher) over time (at least from t = 0 to 3 hours) (Table 1).

[0029] Preparation Example 3 An additive-free hydrogen peroxide solution was prepared by adding nothing to 45% hydrogen peroxide solution that had been purified to a certain level in advance by passing it through the same reverse osmosis membrane as in Preparation Example 1.

[0030] Comparative Example 1 The same procedure as in Example 1 was carried out, except that the hydrogen peroxide solution prepared in Preparation Example 3 was used instead of the hydrogen peroxide solution containing potassium alum prepared in Example 1. The permeate solution that passed through the reverse osmosis membrane device was pooled and sampled every hour, and the metal components in each sample were analyzed by the same ICP-AES. In Comparative Example 1, in which no potassium alum was added, the rejection rate of sodium components by the reverse osmosis membrane device decreased significantly over time (t = 0 to 3 hours) (Table 1).

[0031] (Preparation Example 4) 0.4 ppm of phosphoric acid was added to 45% hydrogen peroxide solution that had been purified to a certain level in advance by passing it through the same reverse osmosis membrane as in Preparation Example 1, and dissolved to prepare hydrogen peroxide solution containing added phosphoric acid.

[0032] Comparative Example 2 The same procedure as in Example 1 was carried out, except that the hydrogen peroxide solution prepared in Preparation Example 4 was used instead of the hydrogen peroxide solution containing potassium alum used in Example 1. The permeate solution passing through the reverse osmosis membrane device was pooled and sampled every hour, and the metal components in each sample were analyzed by the same ICP-AES. The rejection rate of sodium components by the reverse osmosis membrane device decreased over time (t = 0 to 3 hours) (Table 1).

[0033] (Preparation Example 5) 1 ppm of phosphoric acid was added to 45% hydrogen peroxide solution that had been purified to a certain level in advance by passing it through the same reverse osmosis membrane as in Preparation Example 1, and dissolved to prepare hydrogen peroxide solution with 1 ppm of phosphoric acid added.

[0034] Comparative Example 3 The same procedure as in Example 1 was carried out, except that the hydrogen peroxide solution prepared in Preparation Example 5 was used instead of the hydrogen peroxide solution containing potassium alum used in Example 1. The permeate solution that passed through the reverse osmosis membrane device was pooled and sampled every hour, and the metal components in each sample were analyzed by the same ICP-AES. In Comparative Example 3, in which 1 ppm of phosphoric acid was added, the rejection rate of sodium components by the reverse osmosis membrane device decreased over time (t = 0 to 3 hours) (Table 1).

[0035]

[0036] As shown in each example, by passing hydrogen peroxide containing an additive containing potassium alum through a reverse osmosis membrane (RO membrane), the sodium content in the hydrogen peroxide solution is significantly reduced by the RO membrane (high rejection of sodium). Furthermore, the reduction of sodium content by the RO membrane is maintained at a relatively high level over time (maintenance of high rejection of sodium).

[0037] According to the manufacturing method of the present invention, the sodium component in the hydrogen peroxide solution after reverse osmosis membrane treatment can be significantly removed, thereby reducing the load on cation exchange resins and other resins used after reverse osmosis membrane treatment, thereby enabling longer life and cost reduction of cation exchange resins and other resins.

Claims

1. A method for producing purified hydrogen peroxide solution, comprising: passing hydrogen peroxide solution through a first reverse osmosis membrane system; adding an additive to the hydrogen peroxide solution that has passed through the first reverse osmosis membrane system, wherein the additive comprises a double salt containing sulfate ions; and passing the hydrogen peroxide solution to which the additive has been added through a second reverse osmosis membrane system.

2. The manufacturing method according to claim 1, wherein the additive is added in an amount of 0.1 to 50 ppm to the hydrogen peroxide solution that has passed through the first reverse osmosis membrane system.

3. The method of claim 1, wherein the additive further comprises phosphoric acid.

4. The manufacturing method described in claim 1, wherein the concentration (ppm) of the sodium component in the hydrogen peroxide solution that has passed through the second reverse osmosis membrane system is 70% or more lower than the concentration (ppm) of the sodium component in the hydrogen peroxide solution that has passed through the first reverse osmosis membrane system and before the additive is added.

5. The manufacturing method of claim 1, further comprising the step of passing the hydrogen peroxide solution that has passed through the second reverse osmosis membrane system through an adsorption resin tower, a cation exchange resin tower, an anion exchange resin tower, a mixed bed resin tower, or a combination thereof.

6. The method of claim 1, wherein the double salt containing sulfate ions is potassium alum, ammonium alum, chromium alum, iron alum, or a combination thereof.

7. The method according to any one of claims 1 to 6, wherein the double salt containing sulfate ions is potassium alum.

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