Method for producing hydrogen peroxide

Abstract

To provide a method for producing hydrogen peroxide by which the content of water-soluble organic acids in hydrogen peroxide as an intermediate product extracted in an extraction column is reduced, corrosive factors of concentration distillation equipment are reduced and the content of the water-soluble organic acids in hydrogen peroxide as a final product is reduced.SOLUTION: Disclosed is a method for producing hydrogen peroxide using an apparatus for producing hydrogen peroxide, which comprises a working solution tank for storing a working solution containing an organic acid ester, and a working solution cleaner for cleaning the working solution, at least a part of which has been withdrawn from the working solution tank, with water, wherein the flow rate ratio (working solution / water) between the working solution, at least a part of which has been withdrawn from the working solution tank, and water for cleaning the working solution is not more than 12. And a working solution washing step of washing the working solution with water to reduce a content of water-soluble organic acids contained in the working solution.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for producing hydrogen peroxide, and more particularly to a method for producing hydrogen peroxide in which the content of water-soluble organic acids in the final product is reduced. [Background technology]

[0002] In the synthesis of hydrogen peroxide using the anthraquinone method, a mixture of organic solvents called a working solution is used to efficiently dissolve anthraquinone and its hydrogenated compounds. Furthermore, a working solution with low water solubility is selected so that the hydrogen peroxide generated on the anthraquinone can be extracted from the working solution into the aqueous phase. Specifically, the working solution is typically a mixture of alkylanthraquinones and / or alkyltetrahydroanthraquinones dissolved in an organic solvent containing a low-polarity aromatic hydrocarbon and one or more moderately polar compounds selected from the group consisting of higher alcohols, carboxylic acid esters, and tetrasubstituted ureas.

[0003] During the synthesis of hydrogen peroxide, oxidation and reduction are repeated, and the working solution is repeatedly exposed to redox reactions. This leads to the accumulation of impurities by-produced from anthraquinone and organic solvents in the working solution. Therefore, equipment for regenerating the working solution is required. Regeneration reaction equipment using alumina catalysts and impurity removal equipment using alkaline washing are currently installed in plants. Among these, the alumina-catalyzed regeneration reaction of by-product impurities from anthraquinone can also cause side reactions other than the intended regeneration reaction. In fact, when a working solution containing carboxylic acid esters is used, the carboxylic acid esters are hydrolyzed by the alumina catalyst to produce carboxylic acids and alcohols. Compounds that are not removed by subsequent purification steps such as solvent washing, adsorption resins, or distillation remain as impurities in the final hydrogen peroxide product. Depending on the intended use of hydrogen peroxide, trace amounts of carboxylic acids (water-soluble organic acids) can affect the quality of hydrogen peroxide, limiting its use as a final product. Furthermore, corrosion of distillation equipment due to carboxylic acids (water-soluble organic acids) is a concern when concentrating the product in plants.

[0004] Although Patent Document 1 mentions rinsing the working solution with water, the premise is that the hydrogen peroxide generation capacity of the working solution is improved by alkaline treatment of anthraquinone impurities contained in the working solution that are not involved in activity. Since the alkaline components remaining in the working solution after this alkaline treatment affect the hydrogen peroxide generation capacity and may promote the decomposition of hydrogen peroxide, Patent Document 1 only rinsing the working solution with water after this alkaline treatment to remove the alkaline components from the working solution, and does not consider rinsing the working solution alone to be meaningful. Therefore, Patent Document 1 does not propose adding a water washing device using pure water to an existing plant. Furthermore, Patent Document 1 does not describe any problems caused by water-soluble organic acids in hydrogen peroxide as a final product, or any means for solving these problems. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] WO2020 / 105500 Summary of the Invention [Problem to be solved by the invention]

[0006] Under these circumstances, an object of the present invention is to provide a method for producing hydrogen peroxide that reduces the content of water-soluble organic acids in hydrogen peroxide as an intermediate product extracted in an extraction column, thereby reducing the corrosion factors of the concentration and distillation equipment, and also reduces the content of water-soluble organic acids in hydrogen peroxide as a final product. [Means for solving the problem]

[0007] Therefore, the present inventors have conducted extensive research in light of the above problems and have found that the above problems can be solved by a method for producing hydrogen peroxide that includes the following working solution cleaning step.

[0008] That is, the present invention is as follows. <1> A method for producing hydrogen peroxide using a hydrogen peroxide production apparatus including a working solution tank for storing a working solution containing an organic acid ester, and a working solution washer for washing with water the working solution at least partially extracted from the working solution tank, The manufacturing method includes a working solution washing step of washing the working solution with water so that the flow rate ratio (working solution / water) of the working solution at least partially extracted from the working solution tank to the water for washing the working solution is in the range of 12 or less, thereby reducing the content of water-soluble organic acids contained in the working solution. <2> The water used in the working solution washing step is pure water. <1> This is the manufacturing method described in <3> The method includes a step of returning the working solution having a reduced content of water-soluble organic acids to the working solution tank. <1> or <2> This is the manufacturing method described in <4> the hydrogen peroxide production apparatus includes a cleaning water purifier for purifying cleaning water containing water used to clean the working solution, and the method includes a step of reusing the cleaning water purified by the cleaning water purifier as water for cleaning the working solution in the working solution cleaning step. <1> from <3> The manufacturing method according to any one of the above items. <5> The working solution washer is a multi-stage washer. <1> from <4> The manufacturing method according to any one of the above items. <6> The content of water-soluble organic acids in the adjusted concentration hydrogen peroxide product is 50 mg / L or less. <1> from <5> The manufacturing method according to any one of the above items. <7> The cleaning water purifier includes an adsorption resin and / or an ion exchange resin, and the cleaning water is purified by the adsorption resin and / or the ion exchange resin. <4> This is the manufacturing method described in <8> The ion exchange resin is a basic ion exchange resin. <7> This is the manufacturing method described in <9> The basic ion exchange resin is a strongly basic styrene-divinylbenzene copolymer: gel-type ion exchange resin. <8> This is the manufacturing method described in [Effects of the Invention]

[0009] According to one embodiment of the present invention, by reducing the content of water-soluble organic acids in the working solution during operation in the hydrogen peroxide production process, it is possible to provide a method for producing hydrogen peroxide in which the content of water-soluble organic acids in the hydrogen peroxide as an intermediate product extracted in the extraction tower is reduced, thereby reducing the corrosion factors of the concentration and distillation equipment and reducing the content of water-soluble organic acids in the hydrogen peroxide as a final product. Furthermore, according to a preferred embodiment of the present invention, the quality of hydrogen peroxide as a final product can be improved by rinsing the working solution with water using a specific means, and by purifying wash water containing the water used to wash the working solution and reusing the purified water as water for washing the working solution, the efficiency of water use can be improved. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram illustrating the hydrogen peroxide production apparatus used in Examples 1 to 9. [Figure 2] FIG. 2 is a diagram illustrating the hydrogen peroxide production apparatus used in Comparative Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0011] The method for producing hydrogen peroxide of the present invention will be described in detail below. Note that the materials and configurations described below do not limit the present invention, and various modifications can be made within the scope of the present invention. Note that in this specification, when a numerical range is indicated using "to," the numerical values ​​at both ends are included.

[0012] The present invention provides a method for producing hydrogen peroxide using a hydrogen peroxide production apparatus including a working solution tank for storing a working solution containing an organic acid ester, and a working solution washer for washing with water the working solution that has been at least partially extracted from the working solution tank. As shown in Figure 2, conventionally known hydrogen peroxide production systems have not been equipped with a working solution washer, and therefore have not been able to sufficiently reduce the content of water-soluble organic acids in the working solution. As a result, there have been problems such as trace amounts of remaining water-soluble organic acids, such as carboxylic acids, affecting the quality of the final hydrogen peroxide product, and corroding the distillation equipment when concentrating the product in the plant. In the present invention, as shown in FIG. 1, a hydrogen peroxide production apparatus equipped with a working solution washer is used, and the working solution washing step described below is carried out, thereby making it possible to reduce the content of water-soluble organic acids in the working solution during operation in the hydrogen peroxide production process. This reduces the content of water-soluble organic acids in the hydrogen peroxide as an intermediate product extracted in the extraction tower, reduces corrosion factors in the concentration and distillation equipment, and enables the production of hydrogen peroxide as a final product with a reduced content of water-soluble organic acids in the hydrogen peroxide.

[0013] The hydrogen peroxide production apparatus used in the present invention preferably includes a wash water purifier for purifying wash water containing water used after washing the working solution, as shown in Figure 1. The hydrogen peroxide production apparatus used in the present invention also preferably includes a hydrogenation tower downstream of the working solution tank, an oxidation tower downstream of the hydrogenation tower, and an extraction tower downstream of the oxidation tower, as shown in Figure 1. The hydrogen peroxide production apparatus used in the present invention also preferably includes an adsorption purification tower for purifying the crude hydrogen peroxide extracted in the extraction tower (hydrogen peroxide as an intermediate product), a concentration distillation tower for distilling the purified hydrogen peroxide, and a product storage tank for storing the distilled hydrogen peroxide as the final product. The content of water-soluble organic acids contained in hydrogen peroxide as a concentration-adjusted final product is preferably 50 mg / L or less, more preferably 40 mg / L or less, and particularly preferably 2 to 20 mg / L.

[0014] <Working solution cleaning process> The manufacturing method of the present invention includes a working solution washing step in which the working solution, at least a portion of which has been extracted from a working solution tank, is washed with water so that the flow rate ratio (working solution / water) between the working solution and the water for washing the working solution is in the range of 12 or less, thereby reducing the content of water-soluble organic acids contained in the working solution. The content of water-soluble organic acids in the working solution can be efficiently reduced by washing the working solution with water so that the flow rate ratio (working solution / water) is in the range of not more than 12. Specifically, the content of water-soluble organic acids in the hydrogen peroxide (as an intermediate product) extracted in the extraction tower is preferably not more than 60 mg / L, more preferably not more than 40 mg / L, and particularly preferably 2 to 20 mg / L. The flow rate ratio (working solution / water) is preferably in the range of 3-12, and more preferably in the range of 4-7.

[0015] The circulation flow rate of the working solution in the manufacturing process is usually 300 to 500 m depending on the operating load. 3 / h, but the flow rate sent to the working solution regeneration tower is adjusted to about 10% of the circulation flow rate, and a portion of the working solution is extracted from the working solution tank and sent to the working solution regeneration tower. In the present invention, it is preferable to wash the entire amount of working solution at the outlet of the working solution regeneration tower, but it is not necessarily necessary to wash the entire amount depending on the load on the washing machine side. In the present invention, water for washing the working solution is discharged from a working solution washer. By adjusting the amount of water discharged from the working solution washer relative to the flow rate of the working solution at the outlet of the working solution regeneration tower, the flow rate ratio (working solution / water) can be adjusted to be in the range of 12 or less.

[0016] In the present invention, the content of water-soluble organic acids contained in the hydrogen peroxide (as an intermediate product) extracted in the extraction tower and the content of water-soluble organic acids contained in the hydrogen peroxide as a concentration-adjusted final product can be measured using an ion chromatograph for organic acid analysis. The hydrogen peroxide concentrations in the intermediate and final products can be measured using a density measuring device or by titration.

[0017] The water used in the working solution washing step in the present invention is preferably pure water in order to avoid contamination with impurities. In the present invention, a preferred embodiment is one in which a two-stage washer is used as the working solution washer and the working solution is washed with pure water. For example, in the first stage washer, the water after purification by a wash water purifier (described later) is reused as pure water for washing the working solution, and any deficiency is replenished with new pure water. The working solution washer used in the present invention is preferably a device including an agitation tank and a settling tank. The agitation tank may be a mechanical agitator or a static mixer. The settling tank preferably has a volume large enough to provide a sufficient residence time for oil-water separation. Since the working solution used in this manufacturing facility generally has a lower specific gravity than water, the washed working solution is recovered from the top at the outlet of the settling tank. In this device, it is preferable to install a coalescer (oil-water separation filter unit) to minimize entrained water in the working solution.

[0018] <Other processes> In the production method of the present invention, it is preferable that the hydrogen peroxide production apparatus includes a cleaning water purifier for purifying cleaning water containing water used after cleaning the working solution, and that the method further includes a step of reusing the cleaning water purified by the cleaning water purifier as water for cleaning the working solution in the working solution cleaning step. This allows for efficient use of water. The wash water purifier preferably used in the present invention contains an adsorption resin and / or an ion exchange resin, and the wash water can be purified by the adsorption resin and / or the ion exchange resin. The ion exchange resin is preferably a basic ion exchange resin, and more preferably selected from the group consisting of a strongly basic styrene-divinylbenzene copolymer: gel-type ion exchange resin, a strongly basic styrene-divinylbenzene copolymer: macroporous-type ion exchange resin, and a strongly basic styrene-divinylbenzene copolymer: uniform particle size gel-type ion exchange resin. From the viewpoint of breakthrough time, it is particularly preferable to use a strongly basic styrene-divinylbenzene copolymer: gel-type ion exchange resin. The adsorption resin is preferably a non-functional hydrophobic material such as a polyvinylbenzene matrix polymer or a polystyrene-divinylbenzene crosslinked matrix polymer, or / and a polystyrene-divinylbenzene crosslinked matrix polymer with a basic anion functional group. The specific surface area of ​​the resin substrate is 400 m 2 / g or more is preferable, and 600m 2 / g or more is more preferable.

[0019] In a preferred embodiment of the present invention, the method further comprises the step of returning the working solution, the content of which has been reduced, to the working solution tank. This makes it possible to reduce the content of water-soluble organic acids contained in the hydrogen peroxide as an intermediate product. [Example]

[0020] The present embodiment will be described in more detail below with reference to examples, but the present embodiment is not limited to these examples.

[0021] Example 1 Hydrogen peroxide was produced using a hydrogen peroxide production device including a working solution tank for storing a working solution containing an organic acid ester, a working solution washer for washing with water the working solution at least partially extracted from the working solution tank, and a wash water purifier for purifying wash water containing the water used to wash the working solution. Specifically, in a plant operating at 70% load, at least a portion of the working solution extracted from the working solution tank is sent to a working solution regeneration tower, and the flow rate of the working solution at the outlet of the working solution regeneration tower is set to 32 m 3 / h. A two-stage washer was used as the working solution washer, and the working solution was washed with pure water. At this time, the working solution was washed with pure water so that the flow rate ratio (working solution / water) of the working solution at the outlet of the working solution regeneration tower to the pure water for washing the working solution was 12.0, thereby reducing the content of water-soluble organic acids in the working solution. The working solution with the reduced content of water-soluble organic acids was returned to the working solution tank. Meanwhile, a cleaning water purifier containing a hydroxyl-substituted weakly basic acrylic-divinylbenzene copolymer gel structure (product number: Organo Corporation IRA67) was used as a basic ion exchange resin to purify cleaning water containing the water used to wash the working solution. This purified water was reused as pure water for washing the working solution in the working solution washer. In this case, the purified water was reused as pure water for washing the working solution in the first-stage washer, but any shortage was replenished with fresh pure water. When the entire plant was in a stable state, the concentrations of hydrogen peroxide (as an intermediate product) and acetic acid at the aqueous phase outlet of the extraction tower were measured and found to be 46 wt% and 53 mg / L, respectively. The extracted hydrogen peroxide passed through an adsorption purification tower and was concentrated to approximately 60 wt% in a concentration distillation tower, and the products adjusted to each concentration were transferred to product storage tanks. The hydrogen peroxide (as a final product) adjusted to a 35 wt% product contained 40 mg / L of acetic acid. The results are shown in Table 1 below.

[0022] [Table 1]

[0023] Example 2 Hydrogen peroxide was produced in the same manner as in Example 1, except that the flow rate ratio (working solution / water) was changed to 10.0 and a hydroxyl-substituted strongly basic styrene-divinylbenzene copolymer (product number: IRA402, manufactured by Organo Corporation) was used as the basic ion exchange resin. The measurement results are shown in Table 1.

[0024] Example 3 Hydrogen peroxide was produced in the same manner as in Example 1, except that the flow rate ratio (working solution / water) was changed to 8.5 and a hydroxyl-substituted strongly basic styrene-divinylbenzene copolymer (product number: IRA402, manufactured by Organo Corporation) was used as the basic ion exchange resin. The measurement results are shown in Table 1.

[0025] Example 4 Hydrogen peroxide was produced in the same manner as in Example 1, except that the flow rate ratio (working solution / water) was changed to 8.0 and a hydroxyl-substituted weakly basic acrylic-divinylbenzene copolymer gel structure (product number: Organo Corporation IRA67) was used as the basic ion exchange resin. The measurement results are shown in Table 1.

[0026] Example 5 Hydrogen peroxide was produced in the same manner as in Example 1, except that the flow rate ratio (working solution / water) was changed to 5.0 and a hydroxyl-substituted weakly basic acrylic-divinylbenzene copolymer gel structure (product number: Organo Corporation IRA67) was used as the basic ion exchange resin. The measurement results are shown in Table 1.

[0027] Example 6 Hydrogen peroxide was produced in the same manner as in Example 1, except that the flow rate ratio (working solution / water) was changed to 4.0 and a hydroxyl-substituted strongly basic styrene-divinylbenzene copolymer (product number: IRA402, manufactured by Organo Corporation) was used as the basic ion exchange resin. The measurement results are shown in Table 1.

[0028] Example 7 Hydrogen peroxide was produced in the same manner as in Example 1, except that the flow rate ratio (working solution / water) was changed to 3.0. The measurement results are shown in Table 1.

[0029] Example 8 Hydrogen peroxide was produced in the same manner as in Example 1, except that the flow rate ratio (working solution / water) was changed to 2.0 and a hydroxyl-substituted strongly basic styrene-divinylbenzene copolymer (product number: IRA402, manufactured by Organo Corporation) was used as the basic ion exchange resin. The measurement results are shown in Table 1.

[0030] Example 9 Hydrogen peroxide was produced in the same manner as in Example 1, except that the flow rate ratio (working solution / water) was changed to 1.0 and a hydroxyl-substituted strongly basic styrene-divinylbenzene copolymer (product number: IRA402, manufactured by Organo Corporation) was used as the basic ion exchange resin. The measurement results are shown in Table 1.

[0031] (Comparative Example 1) Hydrogen peroxide was produced in the same manner as in Example 1, except that the step of washing the working solution with pure water was not carried out. The measurement results are shown in Table 2.

[0032] [Table 2]

[0033] (Comparative Example 2) Hydrogen peroxide was produced in the same manner as in Example 1, except that the flow rate ratio (working solution / water) was changed to 15.0 and a hydroxyl-substituted strongly basic styrene-divinylbenzene copolymer (product number: IRA402, manufactured by Organo Corporation) was used as the basic ion exchange resin. The measurement results are shown in Table 2.

Claims

1. A method for producing hydrogen peroxide using a hydrogen peroxide production apparatus including a working solution tank for storing a working solution containing an organic acid ester, and a working solution washer for washing with water the working solution at least partially extracted from the working solution tank, The manufacturing method includes a working solution washing step of washing the working solution with water so that the flow rate ratio (working solution / water) of the working solution at least partially extracted from the working solution tank to the water for washing the working solution is in the range of 12 or less, thereby reducing the content of water-soluble organic acids contained in the working solution.

2. The manufacturing method according to claim 1 , wherein the water used in the working solution washing step is pure water.

3. The method according to claim 1 or 2, further comprising the step of returning the working solution having the reduced content of water-soluble organic acids to the working solution tank.

4. 4. The method of claim 1, wherein the hydrogen peroxide production apparatus includes a cleaning water purifier for purifying cleaning water containing water used to clean the working solution, and the method further includes a step of reusing the cleaning water purified by the cleaning water purifier as water for cleaning the working solution in the working solution cleaning step.

5. The method of any one of claims 1 to 4, wherein the working solution washer is a multi-stage washer.

6. 6. The method according to claim 1, wherein the content of water-soluble organic acids in the hydrogen peroxide product after concentration adjustment is 50 mg / L or less.

7. The method according to claim 4, wherein the cleaning water purifier comprises an adsorption resin and / or an ion exchange resin, and the method further comprises purifying the cleaning water by the adsorption resin and / or the ion exchange resin.

8. The method according to claim 7, wherein the ion exchange resin is a basic ion exchange resin.

9. 9. The method according to claim 8, wherein the basic ion exchange resin is a strongly basic styrene-divinylbenzene copolymer: gel-type ion exchange resin.

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