Hydrogen peroxide production method

Abstract

The present invention provides a hydrogen peroxide production method that uses a hydrogen peroxide production apparatus comprising: an extraction tower for extracting hydrogen peroxide; an operating solution tank for storing an operating solution containing an organic acid ester; an operating solution washing device for washing with water an operating solution at least a part thereof being drawn from the operating solution tank; and a wash water purification device for purifying wash water that contains water that has been used to wash the operating solution. The method includes: an operating solution washing step in which the operating solution, at least a part thereof being drawn from the operating solution tank, is washed with water so that the flow rate ratio of the operating solution to the water for washing the operating solution (operating solution / water) falls in the range from 12 and below, thereby reducing the content of water-soluble organic acids contained in the operating solution; and an extraction raw material water utilization step, in which the wash water purification device, which contains an ion exchange resin in the carbonate-type form and / or bicarbonate-type form, purifies the wash water with the ion exchange resin, and subsequently sends the resulting water to the extraction tower, where the water is utilized as water for extracting hydrogen peroxide.

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-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 removed from the working solution tank, and a wash water purifier for purifying wash water containing the water used to wash the working solution, the method including: a working solution washing step for washing the working solution with water so that the flow rate ratio (working solution / water) between the working solution at least partially removed from the working solution tank 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; and an extraction raw water utilization step in which the wash water purifier contains a carbonate and / or bicarbonate ion exchange resin, and the water after purification of the wash water with the ion exchange resin is sent to the extraction tower and used as water for extracting hydrogen peroxide. <2> The production method according to <1> above, wherein the water used in the working solution washing step is pure water. <3> The manufacturing method according to <1> or <2> above, wherein the water used in the extraction raw water utilization step is the water obtained after purifying the wash water using the wash water purifier, or the water obtained by adding pure water to the purified wash water. <4> The manufacturing method according to any one of <1> to <3> above, comprising a step of returning the working solution having a reduced content of water-soluble organic acids to the working solution tank. <5> The manufacturing method according to any one of <1> to <4> above, comprising a step of reusing the water obtained after purifying the wash water using the ion exchange resin as water for washing the working solution in the working solution washing step. <6> The manufacturing method according to any one of <1> to <5> above, wherein the content of water-soluble organic acids contained in the hydrogen peroxide extracted in the extraction tower is 60 mg / L or less. <7> The manufacturing method according to any one of <1> to <6> above, wherein the 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, one embodiment of the present invention purifies wash water containing water used to wash the working solution using an ion exchange resin, and sends the purified water to the extraction column and uses it as water (extraction raw water) for extracting hydrogen peroxide (hereinafter, sometimes referred to as "hydrogen peroxide"). This advantageously allows for 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 in the hydrogenation column and 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, it is important to observe the conditions of the present invention that do not decompose the hydrogen peroxide extracted into the wash water when reducing water-soluble organic acids from 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 washing the working solution with water using a specific means, and the wash water containing the water used to wash the working solution can be purified and reused as water for washing the working solution, thereby making it possible to use water more efficiently.

[0010] Fig. 1 is a diagram illustrating the hydrogen peroxide production apparatus used in Examples 1 to 7. 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 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 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. Conventionally known hydrogen peroxide production apparatuses, as shown in FIG. 2 , did not include a working solution washer and a wash water purifier, and therefore were unable to sufficiently reduce the content of water-soluble organic acids in the working solution. As a result, trace amounts of water-soluble organic acids, such as carboxylic acids, remaining in the working solution could affect the quality of the final hydrogen peroxide product, and the water-soluble organic acids, such as carboxylic acids, could corrode distillation equipment when the product was concentrated in a 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 the working solution washing step and extraction raw water utilization step described below are 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 hydrogen peroxide as an intermediate product extracted in the extraction tower, reduces the corrosion factors of 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 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 extracted in the extraction tower is preferably 60 mg / L or less, more preferably 40 mg / L or less, and particularly preferably 10 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 extracted in the extraction column 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, a portion of the water remaining after purifying the washing water in the extraction raw water utilization step described below is reused as pure water for washing the working solution, and the remaining amount is replenished with new pure water. The working solution washing machine used in the present invention is preferably a device including a stirring tank and a settling tank. The stirring tank may be a mechanical stirring type or a static mixer type. 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] <Extraction raw water utilization step> The production method of the present invention includes an extraction raw water utilization step in which the wash water purifier contains carbonate and / or bicarbonate type ion exchange resins, and the water after purifying the wash water with the ion exchange resin is sent to the extraction tower and used as water for extracting hydrogen peroxide. This has the advantage of allowing the residual hydrogen peroxide in the working solution to be utilized. The flow rate of the extraction raw water in the production process is usually 3 to 5 m depending on the operating load. ３ / h. 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 effects of the present invention can be achieved 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 in a batch or switching mode (continuous use). If 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 raw extraction water utilization step is the water obtained by purifying the wash water using the wash water purifier, or this water plus pure water.

[0019] In the present invention, a carbonate-type and / or bicarbonate-type ion exchange resin is used, and it is 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. From the viewpoint of breakthrough time, it is more preferable to use a strongly basic styrene-divinylbenzene copolymer: gel-type ion exchange resin.

[0020] <Other Steps> In a preferred embodiment of the present invention, the method further comprises a step of reusing the cleaning water, which has been purified by an ion exchange resin, as water for cleaning the working solution in a working solution cleaning step, thereby enabling efficient use of water.

[0021] 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.

[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 system 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, 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. At this time, the content of water-soluble organic acids contained in the working solution was reduced by washing the working solution 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. The working solution with the reduced content of water-soluble organic acids was returned to the working solution tank. Meanwhile, wash water containing the water used to wash the working solution was purified using a wash water purifier containing a bicarbonate-type substituted strongly basic styrene-divinylbenzene copolymer (product number: IRA402, Organo Corporation) as a basic ion exchange resin. The purified water was used as raw extraction water at a flow rate of 2.2 m ３ The extracted hydrogen peroxide was pumped to the extraction tower at a flow rate of 1000 kJ / h, and 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 shortfall 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 was passed through an adsorption purification tower and 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 (final product) adjusted to 35 wt% contained 40 mg / L of acetic acid. The results are shown in Table 1 below.

[0024]

[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: IRA402, manufactured by Organo Corporation) was used as the basic ion exchange resin, and a portion of the purified water was used as the extraction raw water at a flow rate of 2.7 m ３ Hydrogen peroxide was produced in the same manner as in Example 1, except that the working 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.

[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, and hydrogen peroxide was produced in the same manner as in Example 1. The results of the measurements 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: IRA402, manufactured by Organo Corporation) was used as the basic ion exchange resin, and a portion of the purified water was used as the extraction raw water at a flow rate of 3.3 m ３ Hydrogen peroxide was produced in the same manner as in Example 1, except that the working 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.

[0028] (Example 5) In Example 1, the flow rate ratio (working solution / water) was changed to 3.0, and a part of the purified water was used as raw water for extraction at 3.3 m ３ Hydrogen peroxide was produced in the same manner as in Example 1, except that the working 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.

[0029] (Example 6) In Example 1, the flow rate ratio (working solution / water) was changed to 2.0, and a part of the purified water was used as raw water for extraction at 3.3 m ３ Hydrogen peroxide was produced in the same manner as in Example 1, except that the working 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.

[0030] (Example 7) In Example 1, the flow rate ratio (working solution / water) was changed to 1.0, and a 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 working 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.

[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 In Example 1, the flow rate ratio (working solution / water) was changed to 15.0, and a part of the purified water was used as raw water for extraction, and 1.7 m ３ Hydrogen peroxide was produced in the same manner as in Example 1, except that the working 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

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. 　 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, 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. 　 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.

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

3. 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.

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

Images