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: The problem is solved by a method for producing hydrogen peroxide using a hydrogen peroxide production apparatus including an extraction column for extracting hydrogen peroxide, a working solution tank for storing a working solution containing an organic acid ester, a working solution washer for washing the working solution at least partially extracted from the working solution tank with water, and a wash water purifier for purifying wash water containing water after washing the working solution, the method including: A working solution washing step of reducing a content of water-soluble organic acids contained in the working solution by washing the working solution with water so that a flow rate ratio (working solution / water) between the working solution at least partially extracted from the working solution tank and the water for washing the working solution is in a range of 12 or less; the wash water purifier contains an ion exchange resin in a carbonate form and / or a hydrogen carbonate form, and water obtained by purifying the wash water with the ion exchange resin is sent to the extraction tower; And an extraction raw material water utilization step of utilizing the water as water for extracting hydrogen peroxide.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-mentioned problems and have found that the above-mentioned problems can be solved by a method for producing hydrogen peroxide, which includes the following working solution washing step and extraction raw water utilization step.

[0008] That is, the present invention is as follows. <1> A method for producing hydrogen peroxide using a hydrogen peroxide production apparatus including: an extraction tower for extracting hydrogen peroxide; 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, 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 12 or less, thereby reducing the content of water-soluble organic acids in the working solution; the wash water purifier contains a carbonate-type and / or bicarbonate-type ion exchange resin, and the wash water is purified by the ion exchange resin, and the purified water is sent to the extraction tower and used as water for extracting hydrogen peroxide. <2> The water used in the working solution washing step is pure water. <1> This is the manufacturing method described in <3> The water used in the extraction raw water utilization step is the water obtained by purifying the cleaning water using the cleaning water purifier, or the water obtained by adding pure water to the cleaning water. <1> or <2> This is the manufacturing method described in <4> 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> from <3> The manufacturing method according to any one of the above items. <5> The method further comprises a step of reusing the water obtained after purifying the cleaning water with the ion exchange resin as water for cleaning the working solution in the working solution cleaning step. <1> from <4> The manufacturing method according to any one of the above items. <6> The content of water-soluble organic acids contained in the hydrogen peroxide extracted in the extraction tower is 60 mg / L or less. <1> from <5> The manufacturing method according to any one of the above items. <7> The ion exchange resin is a strongly basic styrene-divinylbenzene copolymer: gel-type ion exchange resin. <1> from <6> The manufacturing method according to any one of the above items. [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. In one embodiment of the present invention, wash water containing water used to wash the working solution is purified using an ion exchange resin, and the purified water is sent to an extraction tower and used as water (raw water for extraction) for extracting hydrogen peroxide (hereinafter, sometimes referred to as "hydrogen peroxide"), thereby enabling the utilization of residual hydrogen peroxide in the working solution, which is not utilized in the normal operation of existing plants. Specifically, the residual hydrogen peroxide in the working solution is approximately 0.03 to 0.06 w / v %. In normal operation, the residual hydrogen peroxide in the working solution is completely hydrogenated and decomposed in the hydrogenation tower, and therefore is not used as hydrogen peroxide. However, in the present invention, a portion of the residual hydrogen peroxide can be extracted as hydrogen peroxide. In this case, when reducing the water-soluble organic acids from the wash water, it is important to observe the conditions of the present invention that prevent the decomposition of the hydrogen peroxide extracted into the wash water. 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 7. [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 that includes an extraction tower for extracting hydrogen peroxide, 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. As shown in Figure 2, conventional hydrogen peroxide production systems have not been equipped with a working solution washer and a wash water purifier, 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 and a wash water purifier is used, and by carrying out the working solution washing step and extraction raw water utilization step described below, the content of water-soluble organic acids in the working solution during operation in the hydrogen peroxide production process can be reduced. This reduces the content of water-soluble organic acids in 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 hydrogen peroxide.

[0013] The hydrogen peroxide production apparatus used in the present invention preferably includes a hydrogenation tower downstream of the working solution tank and an oxidation tower downstream of the hydrogenation 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.

[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 extracted in the extraction tower is preferably not more than 60 mg / L, more preferably not more than 40 mg / L, and particularly preferably 10 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 extracted in the extraction column can be measured using an ion chromatograph for analyzing organic acids. 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 to use a two-stage washer as the working solution washer and wash the working solution with pure water. For example, in the first stage washer, a part of the water remaining after purifying the wash water in the extraction raw water utilization step described below is reused as pure water for washing the working solution, and the shortage 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] <Extraction raw water utilization process> The production method of the present invention includes a step of using raw extraction water in which a wash water purifier contains a carbonate-type and / or bicarbonate-type ion exchange resin, and the wash water after purification with the ion exchange resin is sent to an extraction tower and used as water for extracting hydrogen peroxide. This has the advantage that the residual hydrogen peroxide in the working solution can be utilized. The flow rate of the extracted raw water in the manufacturing process is usually 3 to 5 m depending on the operating load. 3 In the present invention, it is preferable to send the entire amount of water obtained after purifying the wash water to the extraction tower as raw extraction water, but the present invention is effective even if the entire amount is not necessarily sent due to the load on the working solution washer side. The wash water purifier used in the present invention preferably includes a column-type resin tower, and can be operated batchwise or by switching (continuous use). When the ion exchange resin breaks through, it can be washed with an aqueous solution of carbonate or bicarbonate, and reused after rinsing with water. In the present invention, the water used in the extraction raw water utilization step is the water obtained by purifying the wash water using a wash water purifier, or the water obtained by adding pure water to the purified wash water.

[0019] In the present invention, carbonate and / or bicarbonate type ion exchange resins are used, and are preferably selected from the group consisting of strongly basic styrene-divinylbenzene copolymer: gel type ion exchange resins, strongly basic styrene-divinylbenzene copolymer: macroporous type ion exchange resins, and strongly basic styrene-divinylbenzene copolymer: uniform particle size gel type ion exchange resins. From the viewpoint of breakthrough time, it is more preferable to use strongly basic styrene-divinylbenzene copolymer: gel type ion exchange resins.

[0020] <Other processes> In a preferred embodiment of the present invention, the method further comprises a step of reusing the cleaning water after purifying it with an ion exchange resin as water for cleaning the working solution in a working solution cleaning step. This allows for efficient use of water.

[0021] 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]

[0022] The present embodiment will be described in more detail below with reference to examples, but the present embodiment is not limited to these examples.

[0023] Example 1 Hydrogen peroxide was produced using a hydrogen peroxide production apparatus including an extraction tower for extracting hydrogen peroxide, 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 washing water purifier containing a bicarbonate-type substituted strongly basic styrene-divinylbenzene copolymer (product number: Organo Corporation IRA402) as a basic ion exchange resin was used to purify washing water containing the water used to wash the working solution. The purified water was used as the raw extraction water in a volume of 2.2 ml. 3 The remaining purified water was reused as pure water for washing the working solution in the working solution washer. In this case, the remaining purified water was reused as pure water for washing the working solution in the first-stage washer, and 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 (a water-soluble organic acid) at the aqueous phase outlet of the extraction tower were measured and found to be 46.21 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.

[0024] [Table 1]

[0025] Example 2 In Example 1, the flow rate ratio (working solution / water) was changed to 10.0, a carbonate-substituted strongly basic styrene-divinylbenzene copolymer (product number: Organo Corporation IRA402) was used as the basic ion exchange resin, and a portion of the purified water was used as the extraction raw water at 2.7 m 3 Hydrogen peroxide was produced in the same manner as in Example 1, except that the solution was pumped to the extraction column at a flow rate of 1000 kJ / h and the remainder was reused as pure water for washing the working solution. The measurement results are shown in Table 1.

[0026] Example 3 In Example 1, the flow rate ratio (working solution / water) was changed to 8.5, and almost all of the purified water (excluding entrained water, 3.3 m 3 / h) was used as the extraction raw material water, hydrogen peroxide was produced in the same manner as in Example 1. The results of each measurement are shown in Table 1.

[0027] Example 4 In Example 1, the flow rate ratio (working solution / water) was changed to 5.0, a carbonate-substituted strongly basic styrene-divinylbenzene copolymer (product number: Organo Corporation IRA402) was used as the basic ion exchange resin, and a portion of the purified water was used as the extraction raw water at 3.3 m 3 Hydrogen peroxide was produced in the same manner as in Example 1, except that the solution was pumped to the extraction column at a flow rate of 1000 kJ / h and the remainder was reused as pure water for washing the working solution. The measurement results are shown in Table 1.

[0028] Example 5 In Example 1, the flow rate ratio (working solution / water) was changed to 3.0, and part of the purified water was used as the raw water for extraction at 3.3 m 3 Hydrogen peroxide was produced in the same manner as in Example 1, except that the solution was pumped to the extraction column at a flow rate of 1000 kJ / h and the remainder was reused as pure water for washing the working solution. The measurement results are shown in Table 1.

[0029] Example 6 In Example 1, the flow rate ratio (working solution / water) was changed to 2.0, and part of the purified water was used as the raw water for extraction at 3.3 m 3 Hydrogen peroxide was produced in the same manner as in Example 1, except that the solution was pumped to the extraction column at a flow rate of 1000 kJ / h and the remainder was reused as pure water for washing the working solution. The measurement results are shown in Table 1.

[0030] Example 7 In Example 1, the flow rate ratio (working solution / water) was changed to 1.0, and part of the purified water was used as the extraction raw water at 3.3 m 3 Hydrogen peroxide was produced in the same manner as in Example 1, except that the solution was pumped to the extraction column at a flow rate of 1000 kJ / h and the remainder was reused as pure water for washing the working solution. 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) In Example 1, the flow rate ratio (working solution / water) was changed to 15.0, and part of the purified water was used as the raw water for extraction at 1.7 m 3 Hydrogen peroxide was produced in the same manner as in Example 1, except that the solution was pumped to the extraction column at a flow rate of 1000 kJ / h and the remainder was reused as pure water for washing the working solution.

Claims

1. A method for producing hydrogen peroxide using a hydrogen peroxide production apparatus including: an extraction tower for extracting hydrogen peroxide; 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, 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; the wash water purifier contains a carbonate-type and / or bicarbonate-type ion exchange resin, and the wash water purified by the ion exchange resin is sent to the extraction tower and used as water for extracting hydrogen peroxide.

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

3. 3. The method according to claim 1, wherein the water used in the extraction raw water utilization step is the water obtained by purifying the cleaning water using the cleaning water purifier, or the water obtained by adding pure water to the cleaning water.

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

5. 5. The method according to claim 1, further comprising a step of reusing the cleaning water purified by the ion exchange resin as water for cleaning the working solution in the working solution cleaning step.

6. 6. The method according to claim 1, wherein the content of water-soluble organic acids in the hydrogen peroxide extracted in the extraction column is 60 mg / L or less.

7. 7. The method according to claim 1, wherein the ion exchange resin is a strongly basic styrene-divinylbenzene copolymer: gel-type ion exchange resin.

Images