Process for producing aqueous hydrogen peroxide solution

Abstract

Provided is a highly efficient method for producing hydrogen peroxide. The solution to the problem is a method for producing hydrogen peroxide, which uses a working solution containing an anthraquinone as a reaction medium and includes a hydrogenation step, an oxidation step, and an extraction step, the method comprising: a step of treating the post-extraction hydrogen peroxide working solution obtained from the extraction step using a zeolite membrane.

Description

Technical Field

[0001] This invention relates to a method for producing hydrogen peroxide using the anthraquinone process. Background Technology

[0002] Industrially, hydrogen peroxide is produced via the auto-oxidation of anthraquinone. Anthraquinone, serving as the reaction medium, is hydrogenated to anthraquinone hydroquinone (hydrogenation process), and then oxidized back to anthraquinone (oxidation process). During the oxidation of anthraquinone, hydrogen peroxide is simultaneously generated and extracted using water (extraction process). Generally, anthraquinone is dissolved in an organic solvent for use; this solution is called the working solution. In industrial hydrogen peroxide production, the working solution is recycled throughout the above processes.

[0003] In the aforementioned manufacturing method, the working solution after the extraction process often becomes a state containing water used for hydrogen peroxide extraction. When the working solution containing water is reintroduced into the hydrogenation process, the activity of the catalyst used for hydrogenation may decrease due to the water. Therefore, as a method for removing water from the working solution, the methods using vacuum dehydration or condensers disclosed in Patent Documents 1-3 have been proposed.

[0004] On the other hand, in recent years, as a method for dehydrating water-containing organic compounds, the methods using zeolite membranes disclosed in Patent Documents 4-8 have been proposed. These methods separate organic compounds from water by using permeation vaporization to allow water molecules to pass through the fine pores of the zeolite membrane.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2003-2620

[0008] Patent Document 2: CN1334235A

[0009] Patent Document 3: CN104370331A

[0010] Patent Document 4: Japanese Patent Application Publication No. 9-131516

[0011] Patent Document 5: WO2007 / 119286

[0012] Patent Document 6: Japanese Patent Application Publication No. 2016-107201

[0013] Patent Document 7: Japanese Patent Application Publication No. 2014-240072

[0014] Patent Document 8: Japanese Patent Application Publication No. 2017-18848 Summary of the Invention

[0015] The technical problem that the invention aims to solve

[0016] As mentioned above, in the production of hydrogen peroxide using the anthraquinone process, the catalyst activity in the hydrogenation process decreases when there is excess water in the working solution. However, existing water removal methods are time-consuming, cannot efficiently produce hydrogen peroxide, and suffer from problems such as excessive energy requirements, high equipment costs, and the potential decomposition of hydrogen peroxide due to the accumulation of stainless steel components in vacuum dehydration or condensers within the hydrogen peroxide production apparatus. Furthermore, the inventors of this invention have clarified that a decrease in the hydrogenation reaction is also observed when there is insufficient water in the working solution. In other words, the water content in the working solution should ideally be close to the saturation solubility of water. The working solution (WS) from the extraction process sometimes contains a large amount of water, and its moisture content may fluctuate; it is desirable to adjust it to an appropriate moisture level.

[0017] Therefore, the object of the present invention is at least one of the following.

[0018] (1) Provide a method for efficiently removing water from the working solution.

[0019] (2) Provide a method for controlling the moisture content of the working solution to a suitable value.

[0020] (3) Provide a highly efficient method for producing hydrogen peroxide.

[0021] (4) Provide a method to suppress the decrease in activity of hydrogenation catalysts.

[0022] (5) Provide a safe method for producing hydrogen peroxide with fewer concerns about hydrogen peroxide decomposition. Technical solutions to address the technical problems.

[0023] In order to solve the above-mentioned technical problems, the inventors of this invention have conducted repeated and in-depth research and found that by using a zeolite membrane to treat the working solution flowing out of the extraction process in an aqueous state, water can be separated from the working solution with high efficiency.

[0024] One aspect of the present invention is as follows.

[0025] [1] A method for manufacturing hydrogen peroxide, comprising a hydrogenation step, an oxidation step, and an extraction step, and using a working solution containing anthraquinones as a reaction medium in a recyclable manner, the method comprising:

[0026] A process for treating the working solution obtained from the extraction process after hydrogen peroxide extraction using a zeolite membrane.

[0027] [2] The manufacturing method as described in [1], wherein the pressure on the permeation side of the zeolite membrane is 60.0 kPa or less.

[0028] [3] The manufacturing method as described in [1] or [2], wherein the temperature of the working solution after hydrogen peroxide extraction treated with the above-mentioned zeolite membrane is above 30°C.

[0029] [4] The manufacturing method as described in any one of [1] to [3], wherein the volume (mL) of the working solution after hydrogen peroxide extraction and the area (m²) of the zeolite membrane are... 2 ) ratio:

[0030] Working solution volume (mL) after hydrogen peroxide extraction / zeolite film area (m²) 2 ) is 50000 (mL / m 2 )above.

[0031] [5] The manufacturing method as described in any one of [1] to [4], wherein the processing time using the zeolite membrane described above is 10 hours or less.

[0032] [6] The manufacturing method as described in any one of [1] to [5], wherein the water content of the working solution after treatment with the above-mentioned zeolite membrane is 0 g / L to 6.0 g / L.

[0033] [7] The manufacturing method as described in any one of [1] to [6] further includes the step of introducing the working solution component that has moved to the permeation side of the zeolite membrane into the extraction step.

[0034] [8] The manufacturing method as described in any one of [1] to [7] further includes a step of regenerating the working solution after treatment with the zeolite membrane.

[0035] [9] A hydrogen peroxide manufacturing system comprising a zeolite membrane module, a hydrogenation tower, an oxidation tower, and an extraction tower, wherein the zeolite membrane module comprises a zeolite membrane and a zeolite membrane permeate delivery pipeline, the hydrogenation tower comprises a hydrogenation catalyst and a hydrogenating agent supply pipeline and an unreacted hydrogenating agent discharge pipeline, the oxidation tower comprises an oxidant supply pipeline and an unreacted oxidant discharge pipeline, the extraction tower comprises a water supply pipeline and a hydrogen peroxide delivery pipeline, the zeolite membrane module and the hydrogenation tower are connected via a zeolite membrane treatment working solution supply pipeline, the hydrogenation tower and the oxidation tower are connected via a hydrogenation working solution supply pipeline, the oxidation tower and the extraction tower are connected via an oxidation working solution supply pipeline, and the zeolite membrane module and the extraction tower are connected via an extraction hydrogen peroxide working solution supply pipeline.

[0036]

[10] The system as described in [9], wherein the zeolite membrane permeate delivery line is connected to the extraction tower.

[0037]

[11] The system as described in [9] or

[10] further includes a working solution regeneration device, wherein the zeolite membrane assembly and the working solution regeneration device are connected via a zeolite membrane-treated working solution supply pipeline, and the hydrogenation tower and the working solution regeneration device are connected via a regenerated working solution supply pipeline. Effects of the Invention

[0038] The present invention achieves one or more of the following effects.

[0039] (1) It can efficiently remove water from the working solution.

[0040] (2) It can remove water from the working solution in a short time.

[0041] (3) It can control the moisture content of the working solution to a suitable value.

[0042] (4) It can produce hydrogen peroxide with high efficiency.

[0043] (5) It can inhibit the decrease in the activity of hydrogenation catalyst.

[0044] (6) It can safely produce hydrogen peroxide. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of one method of the hydrogen peroxide manufacturing system of the present invention.

[0046] Figure 2 This is a schematic diagram of one method of the hydrogen peroxide production system of the present invention, in which the zeolite membrane permeate is fed into the extraction tower.

[0047] Figure 3 This is a schematic diagram of one embodiment of the hydrogen peroxide manufacturing system of the present invention, which includes a working solution regeneration device.

[0048] Figure 4 This is a schematic diagram of one type of vertical zeolite membrane module.

[0049] Figure 5 This is a schematic diagram of one type of horizontal zeolite membrane module.

[0050] Figure 6 These are schematic diagrams of the experimental apparatus used in Examples 1-10. In the diagrams, "PG" stands for Pressure Gauge and "TIC" stands for Temperature Indicator Controller.

[0051] Figure 7This is a graph plotting the results from Table 3. The horizontal axis represents the moisture content of WS (g / L), the vertical axis represents the activity of the hydrogenation catalyst (Nml / (min*g)), and the dashed line represents the saturated water content of the working solution containing TOP at 30℃, which is 2.78 g / L. Detailed Implementation

[0052] One aspect of the present invention relates to a manufacturing method (hereinafter, sometimes referred to as "the manufacturing method of the present invention"), which is a method for manufacturing hydrogen peroxide that uses a working solution containing anthraquinones as a reaction medium in a cyclic manner and includes a hydrogenation step, an oxidation step, and an extraction step, comprising:

[0053] A process for treating the working solution obtained from the extraction process after hydrogen peroxide extraction using a zeolite membrane.

[0054] A method for producing hydrogen peroxide that recycles a working solution containing anthraquinones as a reaction medium and includes a hydrogenation step, an oxidation step, and an extraction step is known in the art as the anthraquinone process.

[0055] Anthraquinones used in the manufacturing method of the present invention include anthraquinones (9,10-anthraquinones), tetrahydroanthraquinones, and their derivatives, which can produce hydrogen peroxide by the anthraquinone process. Derivatives of anthraquinones capable of producing hydrogen peroxide are not limited, and alkylanthraquinones are examples. Alkylanthraquinones refer to anthraquinones substituted with at least one alkyl group. In a particular embodiment, alkylanthraquinones include anthraquinones in which at least one of the 1, 2, or 3 positions is substituted with a straight-chain or branched aliphatic substituent containing at least one carbon atom. The alkyl substituents in alkylanthraquinones preferably contain 1 to 9, more preferably 1 to 6 carbon atoms. Specific examples of alkylanthraquinones are not limited, and examples include methylanthraquinones (such as 2-methylanthraquinone), dimethylanthraquinones (such as 1,3-, 2,3-, 1,4-, and 2,7-dimethylanthraquinone), ethylanthraquinones (such as 2-ethylanthraquinone), propylanthraquinones (such as 2-n-propylanthraquinone and 2-isopropylanthraquinone), butylanthraquinones (such as 2-secondary and 2-tert-butylanthraquinone), and pentylanthraquinones (such as 2-secondary and 2-tert-pentylanthraquinone). Preferred alkylanthraquinones include ethylanthraquinone, pentylanthraquinone, or mixtures thereof. The concentration of the alkylanthraquinone in the working solution is controlled according to the process conditions, and for example, it can be used in a concentration range of 0.4 to 1.0 mol / L.

[0056] As a derivative of tetrahydroanthraquinone capable of generating hydrogen peroxide, it is not limited, and examples include alkyltetrahydroanthraquinones. Alkyltetrahydroanthraquinones refer to tetrahydroanthraquinones substituted with at least one alkyl group. In a particular manner, alkyltetrahydroanthraquinones include tetrahydroanthraquinones in which at least one of the 1, 2, or 3 positions is substituted with a straight-chain or branched aliphatic substituent containing at least one carbon atom. The alkyl substituents in alkyltetrahydroanthraquinones preferably contain 1 to 9, more preferably 1 to 6 carbon atoms. Specific examples of alkyltetrahydroanthraquinones are not limited, and examples include methyltetrahydroanthraquinone (such as 2-methyltetrahydroanthraquinone), dimethyltetrahydroanthraquinone (such as 1,3-, 2,3-, 1,4-, and 2,7-dimethyltetrahydroanthraquinone), ethyltetrahydroanthraquinone (such as 2-ethyltetrahydroanthraquinone), propyltetrahydroanthraquinone (such as 2-n-propyltetrahydroanthraquinone and 2-isopropyltetrahydroanthraquinone), butyltetrahydroanthraquinone (such as 2-secondary and 2-tert-butyltetrahydroanthraquinone), and pentyltetrahydroanthraquinone (such as 2-secondary and 2-tert-pentyltetrahydroanthraquinone). Preferred alkyltetrahydroanthraquinones include ethyltetrahydroanthraquinone, pentyltetrahydroanthraquinone, or mixtures thereof.

[0057] The working solution may contain a nonpolar solvent capable of dissolving anthraquinones and / or a polar solvent capable of dissolving anthraquinones.

[0058] As a nonpolar solvent capable of dissolving anthraquinones, it is not limited to, for example, aromatic hydrocarbons substituted with at least one alkyl group, especially alkylbenzenes containing 8, 9, 10, 11 or 12 carbon atoms (e.g., trimethylbenzene containing 9 carbon atoms (1,2,4-trimethylbenzene (metasylbenzene) etc.) or mixtures thereof).

[0059] Polar solvents capable of dissolving anthraquinones are not limited to, for example, alcohols (e.g., diisobutylmethanol (DIBC), 2-2-ethylhexanol), tetrasubstituted ureas (e.g., tetrabutylurea (TBU)), 2-pyrrolidones or alkylcyclohexyl acetates (e.g., methylcyclohexyl acetate (MCHA)), trioctyl phosphate (TOP), etc.

[0060] Regarding the hydrogenation of the working solution, it can be carried out, for example, by bubbling the working solution with a hydrogen-containing gas such as hydrogen or a mixture of hydrogen and an inert gas (such as nitrogen) in the presence of a hydrogenation catalyst. Regarding the oxidation of the hydrogenated working solution, it can be carried out, for example, by bubbling the working solution with an oxygen-containing gas such as air or oxygen. Regarding the extraction of hydrogen peroxide from the aqueous phase, it can be carried out, for example, by mixing the oxidized working solution with water (typically pure water) and then separating the aqueous phase. The extracted hydrogen peroxide can then be further processed by purification, concentration, etc.

[0061] The amount of water in the working solution obtained after hydrogen peroxide extraction from the extraction process is not particularly limited, and is included in the amount of water typically encountered in hydrogen peroxide production methods using the anthraquinone process. In some methods, the amount of water in the working solution after hydrogen peroxide extraction can be, for example, 0–50 g / L, 0–20 g / L, 0–10 g / L, 1–50 g / L, 3–30 g / L, 5–20 g / L, etc.

[0062] The zeolite constituting the zeolite membrane only needs to be hydrophilic; there are no particular limitations. Examples include MOR-type, LTA-type, CHA-type, FAU-type, or SOD-type zeolites. The zeolite membrane may contain components other than zeolite, such as inorganic binders like silica and alumina, organic substances like polymers, and silanizing agents to modify the zeolite surface, depending on the requirements.

[0063] Zeolite membranes may contain some amorphous components, and are preferably zeolite membranes that are substantially composed of only zeolite.

[0064] The thickness of the zeolite membrane is not particularly limited, but from the viewpoint of permeation and membrane strength, it is typically 0.1 μm or more, preferably 0.6 μm or more, and more preferably 1.0 μm or more. Additionally, it is typically 100 μm or less, preferably 60 μm or less, and more preferably 20 μm or less. Generally, there is a tendency for smaller membrane thickness to result in higher permeation and for larger membrane thickness to result in higher membrane strength.

[0065] The particle size of the zeolite forming the zeolite film is not particularly limited, but is typically 30 nm or more, preferably 50 nm or more, more preferably 100 nm or more, with an upper limit equal to or less than the film thickness. Furthermore, it is more preferable that the zeolite particle size is the same as the film thickness. When the zeolite particle size is the same as the film thickness, the grain boundaries of the zeolite are minimized.

[0066] Typically, zeolite membranes exist as composites with a support (zeolite membrane elements). The shape of the zeolite membrane element is not particularly limited; it can be tubular, hollow filamentous, monolithic, honeycomb, or any other shape. Furthermore, its size is not particularly limited; for example, in the case of a tubular element, a length of 2 cm to 200 cm, an inner diameter of 0.05 cm to 2 cm, and a thickness of 0.5 mm to 4 mm are typically practical and preferred. Zeolite membranes can be used individually or in containers. Preferably, the container has the strength to withstand negative pressure, especially vacuum.

[0067] Typically, the working solution after hydrogen peroxide extraction is treated with a zeolite membrane as follows: the working solution after hydrogen peroxide extraction is suctioned under negative pressure through the zeolite membrane to separate the water from the dehydrated working solution, allowing the water to pass through the inner side (permeable side) of the zeolite membrane, while the dehydrated working solution (the working solution after zeolite membrane treatment) remains on the outer side of the zeolite membrane.

[0068] Regarding the pressure on the permeation side of the zeolite membrane, it is not particularly limited as long as it can remove at least a portion of the water from the working solution after hydrogen peroxide extraction. For example, it is 60.0 kPa or less, preferably 35 kPa or less, more preferably 30 kPa or less, even more preferably 20 kPa or less, and even more preferably 10 kPa or less, especially 1 kPa or less.

[0069] Regarding the temperature of the working solution after hydrogen peroxide extraction using the zeolite membrane, it is not particularly limited as long as it can remove at least a portion of the water from the working solution after hydrogen peroxide extraction. For example, it is below 60°C, preferably 30 to 60°C, more preferably 40 to 60°C, even more preferably 45 to 55°C, and particularly preferably 48 to 52°C.

[0070] Regarding the volume (mL) of the working solution after hydrogen peroxide extraction and the area (m²) of the zeolite film mentioned above... 2 The ratio of water to hydrogen peroxide extract is not particularly limited, as long as it can remove at least a portion of the water from the working solution. For example, it could be 50,000 mL / m³. 2 ) or higher, preferably 55,000 to 70,000 (mL / m 2 More preferably, it is 60,000 to 67,000 (mL / m³). 2 ).

[0071] Regarding the treatment time using zeolite membranes, there are no specific limitations as long as the desired moisture content can be achieved. For example, it can be less than 10 hours, less than 5 hours, less than 4 hours, less than 2 hours, or 0.5 to 2 hours. There is a tendency for the moisture content to decrease earlier as the pressure on the permeate side decreases, so the treatment time can be adjusted appropriately based on the pressure on the permeate side.

[0072] Regarding the moisture content of the working solution after zeolite membrane treatment, there is no particular limitation as long as it does not significantly impair the activity of the hydrogenation catalyst. For example, it can be 0–6.0 g / L, 0–4.0 g / L, 1.0–4.0 g / L, 2.0–4.0 g / L, etc. The inventors of this invention have clarified that the activity of the hydrogenation catalyst is maximized when the moisture content of the working solution is near the saturated solubility of water (saturated water content of the working solution). Therefore, the moisture content of the working solution can typically be, for example, 5–195%, 10–190%, 20–180%, or 30–170% of this saturated solubility value. The most preferred value is the value corresponding to the saturated solubility. The saturated water content of the working solution, as shown in Table 1 below, varies depending on the type of polar solvent contained in the working solution and the temperature; however, anyone skilled in the art can determine an appropriate range of moisture content based on the information disclosed or known in this specification.

[0073] Table 1

[0074] Table 1. Saturated water content corresponding to polar solvents and temperatures.

[0075]

[0076] The manufacturing method of the present invention may further include a step of introducing the working solution component (zeolite membrane permeate) that has moved to the permeate side of the zeolite membrane into the extraction step. This step reduces the amount of water added to the working solution in the extraction step, which is advantageous from the viewpoints of resource saving and cost reduction. Furthermore, while the main component of the zeolite membrane permeate is water, it may also contain small molecular weight organic components (e.g., a portion of non-polar solvents) depending on the characteristics of the zeolite membrane.

[0077] The manufacturing method of the present invention may also include a step of regenerating the working solution after zeolite membrane treatment. Regeneration of the working solution may include, for example, treatment using a regenerating catalyst to regenerate anthraquinones from byproducts derived from anthraquinones. Treatment using a regenerating catalyst allows the working solution after zeolite membrane treatment to pass through a fixed bed or fluidized bed containing the regenerating catalyst. A single pass through the solution may not be sufficient, therefore, circulating the solution is preferable. Activated alumina or silica alumina is preferred as the regenerating catalyst, more preferably activated alumina. The surface area and particle size of the regenerating catalyst are appropriately selected according to the reaction conditions or apparatus, and are not particularly limited. The reaction temperature is preferably in the range of 0–200°C, more preferably 50–150°C. Furthermore, as the reaction proceeds, hydroquinones accumulate, and some of the regeneration reaction slows down; therefore, it is desirable to oxidize the hydroquinones by contact with oxygen or air during circulating the solution. Alternatively, the process can be carried out while simultaneously removing the hydrogen peroxide generated at this time. Through the regeneration step, the hydrogen peroxide production capacity per unit volume of the working solution is increased, enabling more efficient hydrogen peroxide production.

[0078] The manufacturing method of the present invention may further include a step of cleaning the working solution before and / or after the step of regenerating the working solution. Cleaning can be performed using water, alkali, acid, or the like. Cleaning removes various impurities.

[0079] Another aspect of the present invention relates to a hydrogen peroxide manufacturing system having a zeolite membrane assembly, a hydrogenation tower, an oxidation tower, and an extraction tower (hereinafter, sometimes referred to as "the manufacturing system of the present invention").

[0080] In some embodiments, the zeolite membrane module has a zeolite membrane and a zeolite membrane permeate delivery line; the hydrogenation tower has a hydrogenation catalyst and hydrogenating agent supply line and an unreacted hydrogenating agent discharge line; the oxidation tower has an oxidant supply line and an unreacted oxidant discharge line; the extraction tower has a water supply line and a hydrogen peroxide delivery line; the zeolite membrane module and the hydrogenation tower are connected via a zeolite membrane-treated working solution supply line; the hydrogenation tower and the oxidation tower are connected via a hydrogenation working solution supply line; the oxidation tower and the extraction tower are connected via an oxidation working solution supply line; and the extraction tower and the zeolite membrane module are connected via a hydrogen peroxide-extracted working solution supply line. Several embodiments of the hydrogen peroxide manufacturing system of the present invention will be described below with reference to the accompanying drawings.

[0081] Figure 1The document describes a hydrogen peroxide production system A1 comprising a zeolite membrane module 101, a hydrogenation tower 102, an oxidation tower 103, and an extraction tower 104. The zeolite membrane module 101 houses a zeolite membrane and has a zeolite membrane permeate delivery line 105. The hydrogenation tower 102 houses a hydrogenation catalyst and has a hydrogenating agent supply line 106 and an unreacted hydrogenating agent discharge line 107. The oxidation tower 103 has an oxidizing agent supply line 108 and an unreacted oxidizing agent discharge line 109. The extraction tower 104 has a water supply line 110 and a hydrogen peroxide delivery line 111. The zeolite membrane permeate delivery line 105 has a cold trap 112, which includes a pumping mechanism. Vacuum line 113 includes a vacuum pump 114. The zeolite membrane module 101 is connected to the hydrogenation tower 102 via a zeolite membrane treatment working solution supply line 115. The hydrogenation tower 102 is connected to the oxidation tower 103 via a hydrogenation working solution supply line 116. The oxidation tower 103 is connected to the extraction tower 104 via an oxidation working solution supply line 117. The extraction tower 104 is connected to the zeolite membrane module 101 via a hydrogen peroxide extraction working solution supply line 118.

[0082] The working solution after hydrogen peroxide extraction from extraction tower 104 enters zeolite membrane module 101 via working solution supply line 118. Negative pressure is applied to zeolite membrane module 101 using vacuum pump 114, and zeolite membrane permeate 119, which permeates through the zeolite membrane, is transported via zeolite membrane permeate delivery line 105. Zeolite membrane permeate delivery line 105 has a cold trap 112 where gas and liquid are separated. The liquid continues to be transported via zeolite membrane permeate 119 through zeolite membrane permeate delivery line 105, while the gas is discharged as exhaust gas 120 via vacuum line 113. The working solution that has not permeated through the zeolite membrane enters hydrogenation tower 102 via working solution supply line 115. In hydrogenation tower 102, the working solution is hydrogenated by hydrogenating agent 121 supplied from hydrogenating agent supply line 106 in the presence of a hydrogenation catalyst. As a result, anthraquinones contained in the working solution are converted into anthraquinones. Unreacted hydrogenating agent 122 is discharged from unreacted hydrogenating agent discharge line 107. The hydrogenated working solution enters oxidation tower 103 through hydrogenated working solution supply line 116, where it is oxidized by oxidant 123 supplied from oxidant supply line 108. As a result, anthraquinones contained in the working solution are converted to anthraquinones, and hydrogen peroxide is generated. Unreacted oxidant 124 is discharged from unreacted oxidant discharge line 109. The oxidized working solution enters extraction tower 104 through oxidation working solution supply line 117. In extraction tower 104, water 125 supplied from water supply line 110 is mixed with the oxidation working solution, and hydrogen peroxide is extracted to the aqueous phase, which is then taken out as hydrogen peroxide water 126 from hydrogen peroxide delivery line 111. The working solution after hydrogen peroxide extraction is again processed using zeolite membrane module 101 through hydrogen peroxide extraction working solution supply line 118.

[0083] In the hydrogen peroxide production system of the present invention, the zeolite membrane permeate delivery line can be connected to the extraction tower. For an overview of the hydrogen peroxide production system of the present invention with the zeolite membrane permeate delivery line connected to the extraction tower, please refer to... Figure 2 Explanation is required. Specifically, in... Figure 2 In China, regarding Figure 1 The components of the hydrogen peroxide manufacturing system A1 shown are marked with the same symbols, and their descriptions are omitted.

[0084] Figure 2 In the hydrogen peroxide production system B2 shown, the zeolite membrane permeate delivery pipeline 105 is connected to the extraction tower 104, and the zeolite membrane module 101 is connected to the extraction tower 104 through the zeolite membrane permeate delivery pipeline 105.

[0085] In the hydrogen peroxide production system B2, the zeolite membrane permeate from the zeolite membrane assembly 101 is supplied to the extraction tower 104 via the zeolite membrane permeate delivery line 105. Since the zeolite membrane permeate contains a large amount of water, it facilitates the extraction of hydrogen peroxide from the extraction tower 104. Therefore, not only can the zeolite membrane permeate be utilized effectively, but the amount of water 125 supplied from the water supply line 110 can also be saved, contributing to resource conservation and reduced operating costs.

[0086] The manufacturing system of the present invention may further include a working solution regeneration device. In this configuration, the zeolite membrane assembly and the working solution regeneration device can be connected via a zeolite membrane-treated working solution supply pipeline, and the hydrogenation tower and the working solution regeneration device can be connected via a regenerated working solution supply pipeline. For an overview of the hydrogen peroxide manufacturing system of the present invention with a working solution regeneration device, refer to... Figure 3 Explanation is required. Specifically, in... Figure 3 In the middle, to and Figures 1-2 The components of the hydrogen peroxide manufacturing systems A1 to B2 shown are marked with the same symbols, and their descriptions are omitted.

[0087] Figure 3 In the hydrogen peroxide manufacturing system C3 shown, in addition to the components of the hydrogen peroxide manufacturing system B2, there is also a working solution regeneration device 301 with an alumina fixed bed. The zeolite membrane module 101 is connected to the working solution regeneration device 301 through the working solution supply pipeline 115 after zeolite membrane treatment. The hydrogenation tower 102 is connected to the working solution regeneration device 301 through the regenerated working solution supply pipeline 302.

[0088] The working solution, dehydrated by the zeolite membrane module 101 and treated by the zeolite membrane, enters the working solution regeneration unit 301 via the zeolite membrane treated working solution supply line 115. Anthraquinones are regenerated from the anthraquinone byproducts contained in the working solution through the alumina fixed bed of the working solution regeneration unit 301. The regenerated working solution obtained from the working solution regeneration unit 301 enters the hydrogenation tower 102 via the regenerated working solution supply line 302 for the production of hydrogen peroxide. Compared with the unregenerated working solution, the regenerated working solution has a higher concentration of anthraquinones with oxygen peroxide generating capacity and a higher oxygen peroxide performance per unit volume. Therefore, by having a working solution regeneration unit, not only can the oxygen peroxide production efficiency of the oxygen peroxide production system be improved, but the amount of new (unused) anthraquinones added can also be reduced.

[0089] Figure 4 One method of zeolite membrane assembly is shown. Figure 4 The zeolite membrane assembly A4 shown is a vertical assembly, comprising: a disc-shaped tube sheet 402 with multiple tubular zeolite membrane elements 401 disposed thereon, and a settling tank 403 and a head space 404 divided by the tube sheet 402. The settling tank 403 has a working solution supply port 405 for hydrogen peroxide extraction and a working solution discharge port 406 for zeolite membrane treatment, and the head space 404 has a zeolite membrane permeate discharge port 407. When the zeolite membrane assembly A4 is installed in any of the hydrogen peroxide manufacturing systems A1 to C3, the working solution supply line 118 for hydrogen peroxide extraction is connected to the working solution supply port 405, the working solution supply line 115 for zeolite membrane treatment is connected to the working solution discharge port 406, and the zeolite membrane permeate delivery line 105 is connected to the zeolite membrane permeate discharge port 407.

[0090] The working solution 408 after hydrogen peroxide extraction enters the settling tank 403 from the hydrogen peroxide extraction working solution supply port 405. A negative pressure is applied to the zeolite membrane element 401 from the zeolite membrane permeate outlet 407, causing the water contained in the hydrogen peroxide extraction working solution to permeate through the zeolite membrane, enter the tube of the zeolite membrane element 401, pass through the head space 404, and be discharged from the zeolite membrane permeate outlet 407 as zeolite membrane permeate 409. On the other hand, the working solution retained in the settling tank 403, after water removal, is discharged from the zeolite membrane treated working solution outlet 406 as the zeolite membrane treated working solution 410.

[0091] Figure 5 Another way of zeolite membrane assembly is shown in the figure. Figure 5The zeolite membrane module B5 shown is a horizontal module, comprising: a disc-shaped tube sheet 502 with multiple tubular zeolite membrane elements 501 disposed thereon, and a settling tank 503 and a head space 504 divided by the tube sheet 502. In the zeolite membrane module B5, a tube sheet 511 is provided near the end opposite to the head space 504 to support the zeolite membrane elements 501. The settling tank 503 has a working solution supply port 505 for hydrogen peroxide extraction and a working solution discharge port 506 for zeolite membrane treatment, and the head space 504 has a zeolite membrane permeate discharge port 507. When the zeolite membrane module B5 is installed in the hydrogen peroxide manufacturing system A1 to C3, the working solution supply line 118 after hydrogen peroxide extraction is connected to the working solution supply port 505 after hydrogen peroxide extraction, the working solution supply line 115 after zeolite membrane treatment is connected to the working solution discharge port 506 after zeolite membrane treatment, and the zeolite membrane permeate delivery line 105 is connected to the zeolite membrane permeate discharge port 507.

[0092] The working solution 508 after hydrogen peroxide extraction enters the settling tank 503 from the hydrogen peroxide extraction working solution supply port 505. A negative pressure is applied to the zeolite membrane element 501 from the zeolite membrane permeate outlet 507, causing the water contained in the hydrogen peroxide extraction working solution to permeate through the zeolite membrane, enter the tube of the zeolite membrane element 501, pass through the head space 504, and be discharged from the zeolite membrane permeate outlet 507 as zeolite membrane permeate 509. Meanwhile, the working solution retained in the settling tank 503, after water removal, is discharged from the zeolite membrane treated working solution outlet 506 as the zeolite membrane treated working solution 510.

[0093] The hydrogen peroxide production system of the present invention is not limited to the methods described above, and various modifications can be made within the scope of the spirit of the invention. For example, it can be... Figures 1-3 In the hydrogen peroxide production systems A1 to C3 shown, the pipeline for supplying new (unused) working solution is connected to the hydrogenation tower 102, the working solution supply pipeline 115 after zeolite membrane treatment (in the case of hydrogen peroxide production systems A1 to B2), and / or the regenerated working solution supply pipeline 302 (in the case of hydrogen peroxide production system C3); Figure 3 In the hydrogen peroxide manufacturing system C3 shown, a cleaning tank (e.g., a cleaning tank for rinsing the working solution, an acid cleaning tank, and / or a water cleaning tank) is provided before the working solution regeneration device; as needed, pumps or valves, branch lines, etc. are provided in at least one pipeline.

[0094] Example

[0095] The present invention will now be described in detail with reference to specific embodiments, but the present invention is not limited thereto.

[0096] <Method for Determination of Moisture Value in Working Solution (WS)>

[0097] The moisture content was determined using a Karl Fischer reagent (SS3 mg, manufactured by Mitsubishi Chemical Corporation) and a Karl Fischer moisture meter MKS-520 manufactured by Kyoto Electronics Industries, Ltd.

[0098] <WS Moisture Residue Rate>

[0099] Calculated based on the following formula.

[0100] WS moisture residue (%) = WS moisture value / initial moisture value × 100

[0101] <Methods for Determining the Activity Value of Hydrogenation Catalysts>

[0102] Add the hydrogenation catalyst and the working solution of the test object to a 100 mL two-necked flask. Connect one neck of the flask to a stirrer and the other neck to the hydrogen supply unit, sealing the flask. The hydrogen supply unit consists of a hydrogen metering tube, a U-tube manometer, and a water reservoir. During the hydrogenation reaction, the height of the water reservoir is adjusted according to the liquid level changes in the U-tube manometer to maintain the internal pressure of the flask equal to atmospheric pressure. The hydrogen absorption is measured by the change in the liquid level in the hydrogen metering tube. Immerse the flask in a 30°C water bath and let it stand for 10 minutes. Repeat the venting and hydrogen introduction of the flask three times, then start the stirrer. Measure the hydrogen absorption from the start of absorption to 30 minutes later. Convert the hydrogen absorption to the value at 0°C and 1 atm. The activity value of the hydrogenation catalyst is expressed as the standard state hydrogen absorption rate per unit weight of hydrogenation catalyst [NmL / (min×g)]. The hydrogenation catalyst used was 0.05 g of 2 wt% Pd / SiO2 dried at 120 °C.

[0103] (Example 1)

[0104] The working solution (WS type: A) was prepared by dissolving 0.51 mol / L of 2-ethylanthraquinone in a mixed solvent consisting of 25 vol% trioctyl phosphate as a hydroquinone solvent (polar solvent) and 75 vol% C10 aromatic solvent as a quinone solvent (non-polar solvent). The initial moisture value (WS moisture value including free water) was set to 10.50 (g / L).

[0105] use Figure 6 In the experimental setup shown in 6, 300 mL of WS was introduced into reactor 604 for zeolite membrane treatment. The zeolite membrane 605 used was a commercially available ZEBREX (CHA type) zeolite membrane manufactured by Mitsubishi Chemical Corporation, with a zeolite membrane area of ​​0.005 m². 2 Set the speed of the mixer 601 to 1000 rpm, use the vacuum pump 611 to set the pressure on the permeate side of the zeolite membrane to 0.4 kPa, and use the temperature controller 607 to set the temperature of WS to 30℃.

[0106] WS treated with zeolite membrane was periodically extracted from cold trap 610, and the moisture content of WS was measured. The changes in WS moisture content and WS moisture residue over time are shown in Table 2.

[0107] (Example 2)

[0108] Except for setting the initial moisture content to 9.02 g / L and the WS temperature to 40°C, the moisture content of the WS was measured in the same manner as in Example 1. The changes in WS moisture content and WS moisture residue over time are shown in Table 2.

[0109] (Example 3)

[0110] Except for setting the initial moisture content to 15.90 (g / L) and the WS temperature to 50°C, the moisture content of the WS was measured in the same manner as in Example 1. The changes in WS moisture content and WS moisture residue over time are shown in Table 2.

[0111] In addition, for the WS obtained at zeolite membrane treatment times of 0.5hr, 1.0hr, 2.0hr, and 4.0hr, the results of measuring the activity values ​​of the hydrogenation catalyst are shown in Table 3 and [other tables not provided]. Figure 7 .

[0112] (Example 4)

[0113] Except for setting the initial moisture content to 13.25 g / L and the zeolite membrane permeation side pressure to 59.9 kPa, the WS moisture content was measured in the same manner as in Example 3. The changes in WS moisture content and WS moisture residue over time are shown in Table 2.

[0114] (Example 5)

[0115] Except for setting the initial moisture content to 11.63 g / L and the zeolite membrane permeation side pressure to 30.6 kPa, the moisture content of the WS membrane was measured in the same manner as in Example 3. The changes in WS moisture content and WS moisture residue over time are shown in Table 2.

[0116] (Example 6)

[0117] A working solution (WS type: B) was prepared by dissolving 0.6 mol / L of 2-pentylanthraquinone in a mixed solvent consisting of 40 vol% diisobutylmethanol as a hydroquinone solvent and 60 vol% C9 aromatic solvent as a quinone solvent. The initial moisture content was set to 15.40 (g / L). Otherwise, the moisture content of WS was determined in the same manner as in Example 3. The changes in WS moisture content and WS moisture residue over time are shown in Table 2.

[0118] (Example 7)

[0119] A working solution (WS type: C) was prepared by dissolving 0.6 mol / L of 2-ethylanthraquinone in a mixed solvent consisting of 30 vol% tetrabutylurea as a hydroquinone solvent and 70 vol% C10 aromatic solvent as a quinone solvent. The initial moisture content was set at 21.54 g / L. Otherwise, the moisture content of WS was determined in the same manner as in Example 3. The changes in WS moisture content and WS moisture residue over time are shown in Table 2.

[0120] (Example 8)

[0121] The working solution (WS type: D) was prepared by dissolving 0.51 mol / L of 2-ethylanthraquinone in a mixed solvent consisting of 30 vol% 2-methylcyclohexyl acetate as hydroquinone solvent and 70 vol% C10 aromatic solvent as quinone solvent. Except for setting the initial moisture content to 14.76 g / L, the moisture content of WS was determined in the same manner as in Example 3. The changes in WS moisture content and WS moisture residue over time are shown in Table 2.

[0122] (Example 9)

[0123] In addition to setting the initial moisture content to 7.98 g / L and the zeolite film area to 0.003 m², 2 Except for setting the WS volume to 200 mL, the moisture content of WS was measured in the same manner as in Example 3. The changes in WS moisture content and WS moisture residue over time are shown in Table 2.

[0124] (Example 10)

[0125] In addition to setting the initial moisture content to 8.25 g / L and the membrane area to 0.004 m², 2 Except for setting the WS volume to 250 mL, the moisture content of WS was measured in the same manner as in Example 3. The changes in WS moisture content and WS moisture residue over time are shown in Table 2.

[0126] Table 2

[0127] Table 2. Changes in WS moisture content and WS moisture residue over time.

[0128]

[0129] Table 3

[0130] Table 3 Relationship between WS moisture content and hydrogenation catalyst activity

[0131]

[0132] Symbol Explanation

[0133] 1: Hydrogen peroxide manufacturing system A;

[0134] 101: Zeolite membrane module;

[0135] 102: Hydrogenation tower;

[0136] 103: Oxidation tower;

[0137] 104: Extraction tower;

[0138] 105: Zeolite membrane permeate delivery pipeline;

[0139] 106: Hydrogenating agent supply pipeline;

[0140] 107: Unreacted hydrogenating agent discharge pipeline;

[0141] 108: Oxidant supply pipeline;

[0142] 109: Unreacted oxidant discharge line;

[0143] 110: Water supply pipeline;

[0144] 111: Hydrogen peroxide delivery pipeline;

[0145] 112: Cold trap;

[0146] 113: Vacuum pumping line;

[0147] 114: Vacuum pump;

[0148] 115: Working solution supply pipeline after zeolite membrane treatment;

[0149] 116: Hydrogenation working solution supply pipeline;

[0150] 117: Oxidation working solution supply line;

[0151] 118: Working solution supply line after hydrogen peroxide extraction;

[0152] 119: Zeolite membrane permeate;

[0153] 120: Exhaust;

[0154] 121: Hydrogenating agent;

[0155] 122: Unreacted hydrogenating agent;

[0156] 123: Oxidizing agent;

[0157] 124: Unreacted oxidizing agent;

[0158] 125: Water;

[0159] 126: Hydrogen peroxide water;

[0160] 2: Hydrogen peroxide manufacturing system B;

[0161] 3: Hydrogen peroxide manufacturing system C;

[0162] 301: Working solution regeneration device;

[0163] 302: Regeneration working solution supply line;

[0164] 4: Zeolite membrane module A;

[0165] 5: Zeolite membrane module B;

[0166] 401, 501: Zeolite membrane elements;

[0167] 402, 502, 511: Tube sheets;

[0168] 403, 503: Settling tank;

[0169] 404, 504: Headroom;

[0170] 405, 505: Inlets for supplying the working solution after hydrogen peroxide extraction;

[0171] 406, 506: Working solution outlets after zeolite membrane treatment;

[0172] 407, 507: Zeolite membrane permeate outlet;

[0173] 408, 508: Working solutions after hydrogen peroxide extraction;

[0174] 409, 509: Zeolite membrane permeate;

[0175] 410, 510: Working solutions after zeolite membrane treatment;

[0176] 6: Experimental setup;

[0177] 601: Mixer;

[0178] 602: Stirrer;

[0179] 603: Sheathed resistance heater;

[0180] 604: Reactor;

[0181] 605: Zeolite membrane;

[0182] 606: Thermocouple;

[0183] 607: Temperature controller;

[0184] 608, 609: Pressure gauges;

[0185] 610: Cold trap;

[0186] 611: Vacuum pump;

[0187] 612: Pressure gauge;

[0188] V: Valve.

Claims

1. A method for producing hydrogen peroxide, which method uses a working solution containing an anthraquinone as a reaction medium in a circulation system and which method comprises a hydrogenation step, an oxidation step and an extraction step, characterized by comprising: a step of adjusting the moisture content of the working solution after extraction of hydrogen peroxide by using a zeolite membrane to 10 to 190% of the saturated moisture content, the pressure on the permeation side of the zeolite membrane being 1 kPa or less, the working solution after extraction of hydrogen peroxide by using the zeolite membrane having a temperature of 60°C or less and containing a nonpolar solvent capable of dissolving an anthraquinone and a polar solvent capable of dissolving an anthrahydroquinone.

2. The method according to claim 1, characterized in that: the temperature of the working solution after extraction of hydrogen peroxide by using the zeolite membrane is 30°C or more.

3. The method according to claim 1 or 2, characterized in that: the working solution after extraction of hydrogen peroxide by using the zeolite membrane is adjusted to a pH of 2 to 8.

4. The method according to any one of claims 1 to 3, characterized in that: the treatment time of the working solution by using the zeolite membrane is 10 hours or less.

5. The method according to any one of claims 1 to 4, characterized in that: the moisture content of the working solution after treatment by using the zeolite membrane is 1.0 g / L to 6.0 g / L. Further comprising: a step of introducing the components of the working solution moved to the permeation side of the zeolite membrane to the extraction step. Further comprising: a step of regenerating the working solution after treatment by the zeolite membrane. The volume mL of the working solution after extraction of hydrogen peroxide and the area m of the zeolite membrane 2 The ratio of the volume mL of the working solution after extraction of hydrogen peroxide and the area m of the zeolite membrane, i.e. the volume mL of the working solution after extraction of hydrogen peroxide per area m of the zeolite membrane 2 50000 mL / m 2 The above.

8. A hydrogen peroxide production system, characterized by comprising: a zeolite membrane module, a hydrogenation column, an oxidation column and an extraction column, wherein the zeolite membrane module has a zeolite membrane and a zeolite membrane permeation liquid delivery line, the hydrogenation column has a hydrogenation catalyst, a hydrogenation agent supply line and an unreacted hydrogenation agent discharge line, the oxidation column has an oxidizing agent supply line and an unreacted oxidizing agent discharge line, the extraction column has a water supply line and a hydrogen peroxide delivery line, the zeolite membrane module and the hydrogenation column are connected by a working solution after zeolite membrane treatment supply line, the hydrogenation column and the oxidation column are connected by a working solution after hydrogenation supply line, the oxidation column and the extraction column are connected by a working solution after oxidation supply line, and the zeolite membrane module and the extraction column are connected by a working solution after extraction of hydrogen peroxide supply line, the pressure on the permeation side of the zeolite membrane is 1 kPa or less, the working solution after extraction of hydrogen peroxide by using the zeolite membrane has a temperature of 60°C or less and contains a nonpolar solvent capable of dissolving an anthraquinone and a polar solvent capable of dissolving an anthrahydroquinone, and the moisture content of the working solution after extraction of hydrogen peroxide is adjusted to 10 to 190% of the saturated moisture content by using the zeolite membrane.

9. The system according to claim 8, characterized in that: the zeolite membrane permeation liquid delivery line is connected to the extraction column.

10. The system according to claim 8 or 9, characterized by further comprising a working solution regeneration device, the zeolite membrane module and the working solution regeneration device being connected by a working solution after zeolite membrane treatment supply line, and the hydrogenation column and the working solution regeneration device being connected by a regenerated working solution supply line. ​ 6. The production method according to any one of claims 1 to 5, characterized by, ​ ​ 7. The production method according to any one of claims 1 to 6, wherein ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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