Hydrogen peroxide production method

Abstract

The present invention provides a hydrogen peroxide production method using a hydrogen peroxide production device that includes a working solution tank for storing a working solution containing an organic acid ester, and a working solution cleaning machine for cleaning, by using water, at least a portion of the working solution extracted from the working solution tank, the production method comprising a working solution cleaning step for reducing the contained amount of water-soluble organic acids contained in the working solution by cleaning the working solution by using water such that the flow rate ratio (working solution / water) of at least a portion of the working solution extracted from the working solution tank with respect to water for cleaning the working solution falls in a range of 12 or less.

Description

Hydrogen peroxide production method

[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.

[0002] In the synthesis of hydrogen peroxide in the anthraquinone process, 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 hydrogen peroxide generated on anthraquinone can be extracted from the working solution into an aqueous phase. Specifically, the working solution typically used is a mixture of alkylanthraquinone and / or alkyltetrahydroanthraquinone dissolved in an organic solvent containing a low-polarity aromatic hydrocarbon and one or more relatively 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 the 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 working solution's hydrogen peroxide generation capacity is improved by alkaline treatment of the anthraquinone impurities contained in the working solution that are not involved in activity. Since the alkaline components remaining in the working solution after alkaline treatment can affect the hydrogen peroxide generation capacity and potentially promote the decomposition of hydrogen peroxide, Patent Document 1 only rinsing the working solution with water after alkaline treatment to remove the alkaline components, and does not consider rinsing the working solution alone to be meaningful. Therefore, Patent Document 1 does not propose adding a water rinsing device using pure water to an existing plant. Furthermore, Patent Document 1 does not describe any problems associated with water-soluble organic acids in the final hydrogen peroxide product or any means for resolving these problems.

[0005] WO2020 / 105500

[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.

[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 the following method for producing hydrogen peroxide, which includes a 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 removed from the working solution tank, the method including a working solution washing step of reducing the content of water-soluble organic acids in the working solution by washing the working solution with water so that the flow rate ratio (working solution / water) of the working solution at least partially removed from the working solution tank to the water for washing the working solution is 12 or less. <2> The production method according to <1> above, wherein the water used in the working solution washing step is pure water. <3> The production method according to <1> or <2> above, including a step of returning the working solution with a reduced content of water-soluble organic acids to the working solution tank. <4> The method according to any one of <1> to <3>, wherein the hydrogen peroxide production apparatus includes a wash water purifier for purifying wash water containing water used to wash the working solution, and wherein the method includes a step of reusing the water purified by the wash water purifier as water for washing the working solution in the working solution washing step. <5> The method according to any one of <1> to <4>, wherein the work solution washer is a multi-stage washer. <6> The method according to any one of <1> to <5>, wherein the content of water-soluble organic acids contained in the concentration-adjusted product hydrogen peroxide is 50 mg / L or less. <7> The method according to <4>, wherein the wash water purifier includes an adsorption resin and / or an ion exchange resin, and wherein the method includes a step of purifying the wash water with the adsorption resin and / or the ion exchange resin. <8> The method according to <7>, wherein the ion exchange resin is a basic ion exchange resin. <9> The method according to <8>, wherein the basic ion exchange resin is a strongly basic styrene-divinylbenzene copolymer: gel-type ion exchange resin.

[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 a hydrogen peroxide production process, the content of water-soluble organic acids in the hydrogen peroxide intermediate product extracted in the extraction column can be reduced, thereby reducing the corrosion factor of the concentration and distillation equipment and providing a method for producing hydrogen peroxide in which the content of water-soluble organic acids in the hydrogen peroxide final product can be reduced. Furthermore, according to a preferred embodiment of the present invention, the quality of the hydrogen peroxide final product can be improved by washing the working solution with water using a specific means, and water usage can be made more efficient by purifying wash water containing water used to wash the working solution and reusing the purified water for washing the working solution.

[0010] Fig. 1 is a diagram illustrating the hydrogen peroxide production apparatus used in Examples 1 to 9. Fig. 2 is a diagram illustrating the hydrogen peroxide production apparatus used in Comparative Example 1.

[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 work solution tank for storing a work solution containing an organic acid ester and a work solution washer for washing with water the work solution at least partially removed from the work solution tank. Conventionally known hydrogen peroxide production apparatuses, as shown in FIG. 2 , lack a work solution washer and therefore are unable to sufficiently reduce the content of water-soluble organic acids in the work solution. As a result, trace amounts of water-soluble organic acids, such as carboxylic acids, can affect the quality of the final hydrogen peroxide product, and water-soluble organic acids, such as carboxylic acids, can corrode the distillation equipment when the product is concentrated in a plant. In the present invention, as shown in FIG. 1 , the hydrogen peroxide production apparatus includes a work solution washer and performs the work solution washing step described below. This reduces the content of water-soluble organic acids in the work solution during operation in the hydrogen peroxide production process. This reduces the content of water-soluble organic acids in the hydrogen peroxide intermediate product extracted in the extraction column, reduces corrosion of the concentration and distillation equipment, and enables the production of hydrogen peroxide with a reduced content of water-soluble organic acids in the final hydrogen peroxide product.

[0013] As shown in FIG. 1, 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. Furthermore, as shown in FIG. 1, the hydrogen peroxide production apparatus used in the present invention 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. Furthermore, the hydrogen peroxide production apparatus used in the present invention 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 a final product. The content of water-soluble organic acids in the concentration-adjusted final hydrogen peroxide 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 Washing Step> The production 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 the working solution tank, is washed with water so that the flow rate ratio (working solution / water) between the working solution and the water used to wash the working solution is 12 or less, thereby reducing the content of water-soluble organic acids in the working solution. Washing the working solution with water so that the flow rate ratio (working solution / water) is 12 or less can efficiently reduce the content of water-soluble organic acids in the working solution. Specifically, the content of water-soluble organic acids in the hydrogen peroxide (as an intermediate product) extracted in the extraction tower is preferably 60 mg / L or less, more preferably 40 mg / L or less, and particularly preferably 2 to 20 mg / L. Furthermore, the flow rate ratio (working solution / water) is preferably in the range of 3 to 12, more preferably 4 to 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 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 this is not necessarily required depending on the load on the washer side. In the present invention, water for washing the working solution is discharged from the working solution washer, and 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 12 or less.

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

[0017] In the present invention, the water used in the working solution washing step is preferably pure water to avoid the inclusion of impurities. In a preferred embodiment of the present invention, a two-stage washing machine is used as the working solution washing machine, and the working solution is washed with pure water. For example, in the first-stage washing machine, water purified by a wash water purifier (described below) is reused as pure water for washing the working solution, and any deficiency is replenished with new pure water. The working solution washing machine 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 sufficient to provide a residence time sufficient for oil-water separation. Because the working solution used in this manufacturing equipment generally has a lower specific gravity than water, the washed working solution is recovered from the top of the settling tank at the outlet. In this device, a coalescer (oil-water separation filter unit) is preferably installed to minimize entrained water in the working solution.

[0018] <Other Steps> In the production method of the present invention, the hydrogen peroxide production apparatus preferably includes a wash water purifier for purifying wash water containing water used to wash the working solution, and the method preferably includes a step of reusing the water purified by the wash water purifier as water for washing the working solution in the working solution washing step. This allows for efficient use of water. The wash water purifier preferably used in the present invention includes 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 most basic styrene-divinylbenzene copolymer: macroporous-type ion exchange resin, and a strongly basic styrene-divinylbenzene copolymer: uniform particle size gel-type ion exchange resin. The use of a strongly basic styrene-divinylbenzene copolymer: gel-type ion exchange resin is particularly preferred from the viewpoint of breakthrough time. 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 process further includes a step of returning the working solution with a reduced content of water-soluble organic acids to the working solution tank, thereby reducing the content of water-soluble organic acids in the hydrogen peroxide as an intermediate product.

[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 system 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, the working solution at least partially extracted from the working solution tank was sent to a working solution regeneration tower, and the flow rate of the working solution at the outlet of the working solution regeneration tower was increased to 32 m / s. ３ / h. A two-stage washer was used as the working solution washer, and the working solution was washed with pure water. 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 used to wash 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 wash water purifier containing a hydroxyl-substituted weakly basic acrylic-divinylbenzene copolymer gel structure (product number: IRA67, manufactured by Organo Corporation) was used as a basic ion exchange resin to purify wash water containing the water used to wash the working solution. The purified water was reused as pure water for washing the working solution in the working solution washer. In this case, the purified water in the first-stage washer was reused as pure water for washing the working solution, but any deficiency 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]

[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: IRA67, manufactured by Organo Corporation) 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: IRA67, manufactured by Organo Corporation) 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 strong 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]

[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 strong 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 device 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 method including a working solution washing step for reducing the content of water-soluble organic acids in the working solution by 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.

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

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

4. The manufacturing method according to claim 1 or 2, wherein the hydrogen peroxide manufacturing 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 water used to clean the working solution in the working solution cleaning step after the cleaning water has been purified by the cleaning water purifier.

5. The method of claim 1 or 2, wherein the working solution washer is a multi-stage washer.

6. The manufacturing method according to claim 1 or 2, wherein the content of water-soluble organic acids contained in the concentration-adjusted product hydrogen peroxide is 50 mg / L or less.

7. The manufacturing method according to claim 4, wherein the cleaning water purifier includes an adsorption resin and / or an ion exchange resin, and the manufacturing method includes a step of 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. The method according to claim 8, wherein the basic ion exchange resin is a strongly basic styrene-divinylbenzene copolymer: gel-type ion exchange resin.

Images