阅读说明：本技术 过氧化氢水溶液的制造方法 (Method for producing aqueous hydrogen peroxide solution ) 是由 茂田耕平 松本伦太朗 田崎贤 于 2019-07-09 设计创作，主要内容包括：本发明提供一种过氧化氢的高效率的制造方法。其解決手段为一种制造方法,其是作为反应介质循环使用包含蒽醌类的工作溶液且包括氢化工序、氧化工序和提取工序的过氧化氢的制造方法,包括：利用沸石膜对从提取工序得到的提取过氧化氢后工作溶液进行处理的工序。(The invention provides a method for efficiently producing hydrogen peroxide. The solving means is a method for producing hydrogen peroxide, which comprises a hydrogenation step, an oxidation step and an extraction step, wherein a working solution containing an anthraquinone is recycled as a reaction medium, and which comprises: and a step of treating the hydrogen peroxide-extracted working solution obtained in the extraction step with a zeolite membrane.)

1. A method for producing hydrogen peroxide, which comprises a hydrogenation step, an oxidation step and an extraction step, wherein a working solution containing an anthraquinone as a reaction medium is recycled, and which comprises:

and a step of treating the hydrogen peroxide-extracted working solution obtained in the extraction step with a zeolite membrane.

2. The manufacturing method according to claim 1, wherein:

the pressure on the permeation side of the zeolite membrane is 60.0kPa or less.

3. The manufacturing method according to claim 1 or 2, characterized in that:

the temperature of the working solution after extracting hydrogen peroxide, which is treated by the zeolite membrane, is above 30 ℃.

4. The production method according to any one of claims 1 to 3, characterized in that:

the volume mL of the working solution after the hydrogen peroxide extraction and the area m of the zeolite membrane²Ratio of (A) to (B), i.e. volume mL of working solution after extraction of hydrogen peroxide/area m of zeolite membrane²Is 50000mL/m²The above.

5. The production method according to any one of claims 1 to 4, characterized in that:

the treatment time for the zeolite membrane treatment is 10 hours or less.

6. The production method according to any one of claims 1 to 5, characterized in that:

the water content of the working solution treated by the zeolite membrane is 0 g/L-6.0 g/L.

7. The manufacturing method according to any one of claims 1 to 6, further comprising: and a step of introducing the working solution component that has migrated to the permeation side of the zeolite membrane into the extraction step.

8. The manufacturing method according to any one of claims 1 to 7, further comprising: and regenerating the working solution treated with the zeolite membrane.

9. A hydrogen peroxide production system characterized by:

the hydrogen peroxide production system comprises 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 transfer pipeline,

the hydrogenation tower has a hydrogenation catalyst, a 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 is communicated with the hydrogenation tower through a zeolite membrane treated working solution supply pipeline, the hydrogenation tower is communicated with the oxidation tower through a hydrogenated working solution supply pipeline, the oxidation tower is communicated with the extraction tower through an oxidized working solution supply pipeline, and the zeolite membrane module is communicated with the extraction tower through a hydrogen peroxide extracted working solution supply pipeline.

10. The system of claim 9, wherein:

the zeolite membrane permeate transfer pipeline is communicated with the extraction tower.

11. The system of claim 9 or 10, wherein:

the device also comprises a working solution regeneration device, the zeolite membrane component is communicated with the working solution regeneration device through a working solution supply pipeline after the zeolite membrane is treated, and the hydrogenation tower is communicated with the working solution regeneration device through a regenerated working solution supply pipeline.

Technical Field

The present invention relates to a method for producing hydrogen peroxide by an anthraquinone method.

Background

Hydrogen peroxide is industrially produced by the auto-oxidation of anthraquinone. Anthraquinone as a reaction medium is hydrogenated to anthrahydroquinone (hydrogenation step), and the anthrahydroquinone is oxidized to anthraquinone (oxidation step). When anthrahydroquinone is oxidized, hydrogen peroxide is simultaneously produced, and extraction is performed with water (extraction step). In general, anthraquinone is used by being dissolved in an organic solvent, and this solution is referred to as a working solution. In an industrial hydrogen peroxide production process, the working solution is recycled in the above-described step.

In the above production method, the working solution after the extraction step is often in a state of containing water for extracting hydrogen peroxide. When the working solution containing water is again introduced into the hydrogenation step, there is a possibility that the activity of the catalyst used for hydrogenation is lowered by water. In view of the above, as a method for removing water in the working solution, methods using vacuum dehydration or a coalescer disclosed in patent documents 1 to 3 have been proposed.

On the other hand, in recent years, as a dehydration method for an organic compound containing water, methods using a zeolite membrane have been proposed as disclosed in patent documents 4 to 8. These methods are methods of separating an organic compound from water by passing water molecules through pores of a zeolite membrane by permeation and vaporization.

Disclosure of Invention

Technical problem to be solved by the invention

As described above, in general, when hydrogen peroxide is produced by the anthraquinone method, if the water content in the working solution is excessive, the activity of the catalyst in the hydrogenation step is lowered. However, the conventional water removal method requires a long time for dehydration, and thus hydrogen peroxide cannot be efficiently produced, and there are problems that excessive energy is required, the equipment cost is high, and decomposition of hydrogen peroxide may be caused due to accumulation of stainless steel components in the hydrogen peroxide production apparatus or vacuum dehydration. Further, the inventors of the present invention have clarified that even when the water content in the working solution is excessively low, the hydrogenation reaction is observed to be decreased. In other words, it is considered that the water content in the working solution is preferably in the vicinity of the saturation solubility of water. The Working Solution (WS) from the extraction step may contain a large amount of water or the like, and the moisture value may vary, and it is desirable to adjust the moisture value to an appropriate value.

Accordingly, the object of the present invention is at least 1 of the following.

(1) A method for efficiently removing water from a working solution is provided.

(2) A method for controlling the moisture value of a working solution to a suitable value is provided.

(3) Provided is a method for producing hydrogen peroxide with high efficiency.

(4) Provided is a method for suppressing a decrease in the activity of a hydrogenation catalyst.

(5) Provided is a safe method for producing hydrogen peroxide, which is less likely to decompose hydrogen peroxide. Technical solution for solving technical problem

The present inventors have made extensive studies to solve the above-mentioned problems, and as a result, have found that water can be efficiently separated from a working solution flowing out from an extraction step in a hydrous state by treating the working solution with a zeolite membrane.

One aspect of the present invention is as follows.

[1] A method for producing hydrogen peroxide by recycling a working solution containing anthraquinones as a reaction medium and including a hydrogenation step, an oxidation step and an extraction step, comprising:

and a step of treating the hydrogen peroxide-extracted working solution obtained in the extraction step with a zeolite membrane.

[2] The process according to [1], wherein the pressure on the permeation side of the zeolite membrane is 60.0kPa or less.

[3] The production process according to [1] or [2], wherein the temperature of the working solution after hydrogen peroxide extraction, which is treated with the zeolite membrane, is 30 ℃ or higher.

[4]Such as [1]]～[3]The production method according to any one of the above methods, wherein the volume (mL) of the working solution after hydrogen peroxide extraction and the area (m) of the zeolite membrane are the same²) The ratio of (A) to (B):

volume of working solution (mL)/area of zeolite membrane (m) after extraction of hydrogen peroxide²) Is 50000 (mL/m)²) The above.

[5] The production process according to any one of [1] to [4], wherein the treatment time for the zeolite membrane is 10 hours or less.

[6] The production process according to any one of [1] to [5], wherein the water content of the working solution treated with the zeolite membrane is 0 to 6.0 g/L.

[7] The production method according to any one of [1] to [6], further comprising: and a step of introducing the working solution component that has moved to the permeation side of the zeolite membrane into the extraction step.

[8] The production method according to any one of [1] to [7], further comprising: and regenerating the working solution treated with the zeolite membrane.

[9] A hydrogen peroxide production system comprising a zeolite membrane module, a hydrogenation column, an oxidation column and an extraction column, wherein the zeolite membrane module comprises a zeolite membrane and a zeolite membrane permeate transfer line, the hydrogenation column comprises a hydrogenation catalyst and a hydrogenation agent supply line and an unreacted hydrogenation agent discharge line, the oxidation column comprises an oxidant supply line and an unreacted oxidant discharge line, the extraction column comprises a water supply line and a hydrogen peroxide transfer line, the zeolite membrane module is communicated with the hydrogenation column through a zeolite membrane treated working solution supply line, the hydrogenation column is communicated with the oxidation column through a hydrogenation working solution supply line, the oxidation column is communicated with the extraction column through an oxidation working solution supply line, and the zeolite membrane module is communicated with the extraction column through a hydrogen peroxide extracted working solution supply line.

[10] The system according to [9], wherein the zeolite membrane permeate transfer line is in communication with the extraction column.

[11] The system as recited in claim 9 or 10, further comprising a working solution regeneration device, the zeolite membrane module being in communication with the working solution regeneration device through a working solution supply line after the zeolite membrane treatment, the hydrogenation column being in communication with the working solution regeneration device through a regenerated working solution supply line. ADVANTAGEOUS EFFECTS OF INVENTION

The present invention exhibits the following 1 or more effects.

(1) The water in the working solution can be removed efficiently.

(2) The moisture in the working solution can be removed in a short time.

(3) The moisture value of the working solution can be controlled to an appropriate value.

(4) Hydrogen peroxide can be efficiently produced.

(5) The reduction in activity of the hydrogenation catalyst can be suppressed.

(6) Hydrogen peroxide can be produced safely.

Drawings

Fig. 1 is a schematic view of one mode of the hydrogen peroxide production system of the present invention.

FIG. 2 is a schematic view of one embodiment of the hydrogen peroxide production system of the present invention in which a zeolite membrane permeate is fed to an extraction column.

Fig. 3 is a schematic view of one mode of the hydrogen peroxide production system of the present invention having a working solution regeneration device.

FIG. 4 is a schematic of one mode of a vertical zeolite membrane module.

Figure 5 is a schematic of one way of horizontal zeolite membrane module.

FIG. 6 is a schematic view of the experimental apparatus used in examples 1 to 10. In the figure, "PG" means pressure gauge and "TIC" means Temperature Indicator Controller.

Fig. 7 is a graph plotting the results of table 3. The horizontal axis represents the WS water content (g/L), the vertical axis represents the activity of the hydrogenation catalyst (Nml/(min × g)), and the dotted line represents the saturated water content at 30 ℃ of the TOP-containing working solution, which is 2.78 g/L.

Detailed Description

One embodiment of the present invention relates to a method for producing hydrogen peroxide, which recycles a working solution containing anthraquinones as a reaction medium and includes a hydrogenation step, an oxidation step, and an extraction step (hereinafter, may be referred to as "the production method of the present invention"), and which includes:

and a step of treating the hydrogen peroxide-extracted working solution obtained in the extraction step with a zeolite membrane.

A method for producing hydrogen peroxide, which comprises a hydrogenation step, an oxidation step and an extraction step and which comprises recycling a working solution containing anthraquinones as a reaction medium, is known as the anthraquinone method in the art.

Examples of the anthraquinones used in the production method of the present invention include anthraquinone (9, 10-anthracenedione), tetrahydroanthraquinone, and derivatives thereof, which are capable of producing hydrogen peroxide by the anthraquinone method. The derivative of anthraquinone capable of generating hydrogen peroxide is not limited, and examples thereof include alkylanthraquinones. Alkyl anthraquinone means an anthraquinone substituted with at least 1 alkyl group. In a particular mode, the alkylanthraquinones include anthraquinones having at least one of the 1,2 or 3 positions substituted with a straight or branched aliphatic substituent comprising at least 1 carbon atom. The alkyl substituent in the alkylanthraquinone preferably contains 1 to 9, more preferably 1 to 6 carbon atoms. Specific examples of the alkylanthraquinones include, but are not limited to, methylanthraquinone (e.g., 2-methylanthraquinone), dimethylanthraquinone (e.g., 1, 3-, 2, 3-, 1, 4-, 2, 7-dimethylanthraquinone), ethylanthraquinone (e.g., 2-ethylanthraquinone), propylanthraquinone (e.g., 2-n-propylanthraquinone, 2-isopropylanthraquinone), butylanthraquinone (e.g., 2-sec-or 2-tert-butylanthraquinone), amylanthraquinone (e.g., 2-sec-or 2-tert-amylanthraquinone), and the like. Preferred alkylanthraquinones include ethylanthraquinone, amylanthraquinone, and mixtures thereof. The concentration of the alkylanthraquinones in the working solution is controlled in accordance with the process conditions, and may be used in a concentration range of, for example, 0.4 to 1.0 mol/L.

The derivative of tetrahydroanthraquinone capable of generating hydrogen peroxide is not limited, and examples thereof include alkyltetrahydroanthraquinones. Alkyl tetrahydroanthraquinone means tetrahydroanthraquinone substituted with at least 1 alkyl group. In a particular mode, the alkyltetrahydroanthraquinones include tetrahydroanthraquinones substituted in at least one of the 1,2, or 3 positions with a straight or branched aliphatic substituent comprising at least 1 carbon atom. The alkyl substituent in the alkyltetrahydroanthraquinone preferably contains 1 to 9, more preferably 1 to 6 carbon atoms. Specific examples of the alkyltetrahydroanthraquinones include, but are not limited to, methyltetrahydroanthraquinone (e.g., 2-methyltetrahydroanthraquinone), dimethyltetrahydroanthraquinone (e.g., 1, 3-, 2, 3-, 1, 4-, 2, 7-dimethyltetrahydroanthraquinone), ethyltetrahydroanthraquinone (e.g., 2-ethyltetrahydroanthraquinone), propyltetrahydroanthraquinone (e.g., 2-n-propyltetrahydroanthraquinone, 2-isopropyltetrahydroanthraquinone), butyltetrahydroanthraquinone (e.g., 2-sec-or 2-tert-butyltetrahydroanthraquinone), pentyltetrahydroanthraquinone (e.g., 2-sec-or 2-tert-pentyltetrahydroanthraquinone), and the like. Preferred alkyltetrahydroanthraquinones include ethyltetrahydroanthraquinone, pentyltetrahydroanthraquinone, and mixtures thereof.

The working solution may contain a nonpolar solvent capable of dissolving the anthraquinones and/or a polar solvent capable of dissolving the anthrahydroquinones.

The nonpolar solvent capable of dissolving the anthraquinones is not limited, and examples thereof include aromatic hydrocarbons substituted with at least 1 alkyl group, particularly alkylbenzenes having 8, 9,10, 11, or 12 carbon atoms (e.g., trimethylbenzene having 9 carbon atoms (e.g., 1,2, 4-trimethylbenzene (pseudotrimethylbenzene)), and mixtures thereof.

Examples of the polar solvent capable of dissolving the anthrahydroquinones include, but are not limited to, alcohols (e.g., Diisobutylcarbinol (DIBC) and 2-2-ethylhexanol), tetra-substituted ureas (e.g., Tetrabutylurea (TBU)), 2-pyrrolidone, alkylcyclohexylacetate (e.g., Methylcyclohexylacetate (MCHA)), and Trioctylphosphonate (TOP).

The hydrogenation of the working solution can be performed, for example, by bubbling (bubbling) the working solution with a hydrogen-containing gas such as hydrogen gas or a mixture of an inert gas (e.g., nitrogen gas) and hydrogen gas in the presence of a hydrogenation catalyst. The oxidation of the hydrogenated working solution can be performed, for example, by bubbling the working solution with an oxygen-containing gas such as air or oxygen. The extraction of hydrogen peroxide into an aqueous phase can be performed, for example, by mixing the oxidized working solution with water (typically pure water) and then separating the water phase from the mixture. The extracted hydrogen peroxide may be subjected to a treatment such as purification or concentration.

The amount of water contained in the working solution after extraction of hydrogen peroxide obtained from the extraction step is not particularly limited, and includes the amount of water that is generally encountered in a hydrogen peroxide production method using the anthraquinone method. In some embodiments, the amount of water contained in the working solution after the extraction of hydrogen peroxide may be, for example, 0 to 50g/L, 0 to 20g/L, 0 to 10g/L, 1 to 50g/L, 3 to 30g/L, 5 to 20g/L, or the like.

The zeolite constituting the zeolite membrane is not particularly limited as long as it is hydrophilic, and examples thereof include MOR-type, LTA-type, CHA-type, FAU-type, and SOD-type zeolites. The zeolite membrane may contain components other than zeolite, for example, inorganic binders such as silica and alumina, organic materials such as polymers, and silylation agents for modifying the zeolite surface, as required.

The zeolite membrane may contain a part of the amorphous component, and is preferably a zeolite membrane substantially composed of only zeolite.

The thickness of the zeolite membrane is not particularly limited, but is typically 0.1 μm or more, preferably 0.6 μm or more, and more preferably 1.0 μm or more from the viewpoint of the permeability, membrane strength, and the like. The particle size is typically 100 μm or less, preferably 60 μm or less, and more preferably 20 μm or less. In general, the smaller the film thickness, the larger the transmittance, and the larger the film thickness, the higher the film strength tends to be.

The particle size of the zeolite forming the zeolite membrane is not particularly limited, but is typically 30nm or more, preferably 50nm or more, and more preferably 100nm or more, with the upper limit being the thickness of the membrane or less. Further, the particle diameter of the zeolite is more preferably the same as the thickness of the membrane. The grain size of the zeolite is the same as the thickness of the membrane, and the grain boundary of the zeolite is the smallest.

Typically, the zeolite membrane is present as a composite with a support (zeolite membrane element). The shape of the zeolite membrane element is not particularly limited, and any shape such as a tubular shape, a hollow filament shape, a monolithic shape, and a honeycomb shape can be used. The size is not particularly limited, and for example, in the case of a tubular shape, the length is typically 2cm to 200cm, the inner diameter is typically 0.05cm to 2cm, and the thickness is typically 0.5mm to 4 mm. The zeolite membrane may be used as a single body, or 1 or more zeolite membranes may be stored in a container and used. Preferably, the container has a strength capable of withstanding a negative pressure, in particular capable of withstanding a vacuum.

Typically, the treatment of the working solution with the zeolite membrane after extraction of hydrogen peroxide is as follows: the working solution after hydrogen peroxide extraction is sucked at a negative pressure through the zeolite membrane to separate water from the dehydrated working solution, and the dehydrated working solution (working solution after zeolite membrane treatment) is left on the outer side of the zeolite membrane while allowing water to permeate through the inner side (permeation side) of the zeolite membrane.

The pressure on the permeation side of the zeolite membrane is not particularly limited as long as at least a part of water can be removed from the working solution after the hydrogen peroxide extraction, and is, for example, 60.0kPa or less, preferably 35kPa or less, more preferably 30kPa or less, still more preferably 20kPa or less, further preferably 10kPa or less, and particularly 1kPa or less.

The temperature of the working solution after hydrogen peroxide extraction treated with the zeolite membrane is not particularly limited as long as at least a part of water can be removed from the working solution after hydrogen peroxide extraction, and is, for example, 60 ℃ or less, preferably 30 to 60 ℃, more preferably 40 to 60 ℃, still more preferably 45 to 55 ℃, and particularly preferably 48 to 52 ℃.

Volume (mL) of working solution after extraction of hydrogen peroxide and area (m) of the zeolite membrane²) The ratio of (d) is not particularly limited as long as at least a part of water can be removed from the working solution after extraction of hydrogen peroxide, and is, for example, 50000 (mL/m)²) Above, preferably 55000 to 70000 (mL/m)²) More preferably 60000 to 67000 (mL/m)²)。

The treatment time with the zeolite membrane is not particularly limited as long as a desired moisture value can be obtained, and may be, for example, 10 hours or less, 5 hours or less, 4 hours or less, 2 hours or less, 0.5 to 2 hours, or the like. Since the moisture value tends to decrease as the pressure on the permeate side decreases, the treatment time can be appropriately adjusted according to the pressure on the permeate side.

The water content of the working solution after the zeolite membrane treatment is not particularly limited as long as the activity of the hydrogenation catalyst is not significantly impaired, and may be, for example, 0 to 6.0g/L, 0 to 4.0g/L, 1.0 to 4.0g/L, 2.0 to 4.0g/L, or the like. It is clarified by the inventors of the present invention that the activity of the hydrogenation catalyst is maximum when the moisture value of the working solution is in the vicinity of the saturation solubility of water (saturation water content of the working solution). Therefore, the moisture value of the working solution is typically 5 to 195%, 10 to 190%, 20 to 180%, 30 to 170% of the value corresponding to the saturation solubility. Most preferred is a value corresponding to the saturation solubility. However, the saturated water content of the working solution differs depending on the type and temperature of the polar solvent contained in the working solution as shown in table 1 below, and a person skilled in the art can determine an appropriate range of the water content value based on the disclosure of the present specification or known information.

[ TABLE 1]

TABLE 1 saturated water content corresponding to polar solvent and temperature

The manufacturing method of the present invention may further include: introducing the working solution component (zeolite membrane permeate) that has migrated to the permeation side of the zeolite membrane into the extraction step. This step can reduce the amount of water to be added to the working solution in the extraction step, and is advantageous from the viewpoint of resource saving, cost saving, and the like. The zeolite membrane permeate mainly contains water, but the zeolite membrane permeate may contain an organic component having a small molecular weight (e.g., a part of a nonpolar solvent) depending on the properties of the zeolite membrane.

The production method of the present invention may further comprise a step of regenerating the working solution after the zeolite membrane treatment. Regeneration of the working solution, for example, includes: a process for regenerating anthraquinones from by-products derived from the anthraquinones by using a regenerated catalyst. The treatment with the regenerated catalyst can be carried out by passing the working solution after the zeolite membrane treatment through a fixed bed or a fluidized bed containing the regenerated catalyst. Since the liquid passing may be insufficient 1 time, it is preferable to circulate the liquid. As the regenerated catalyst, activated alumina or silica alumina is preferable, and activated alumina is more preferable. The surface area and particle size of the regenerated catalyst are appropriately selected depending on the reaction conditions or apparatus, and are not particularly limited. The reaction temperature is preferably in the range of 0 to 200 ℃, and more preferably 50 to 150 ℃. Further, as the reaction proceeds, hydroquinone is accumulated and a part of the regeneration reaction proceeds slowly, and therefore, it is desired to oxidize hydroquinone by contacting with oxygen or air in the middle of circulating the liquid. Further, the hydrogen peroxide generated at this time may be removed. By the regeneration step, the hydrogen peroxide generation capacity per unit volume of the working solution is improved, and hydrogen peroxide can be produced more efficiently.

The manufacturing method of the present invention may further include a step of washing the working solution before and/or after the step of regenerating the working solution. Washing may be performed with water, alkali, acid, or the like. Various impurities can be removed by washing.

Another embodiment of the present invention relates to a hydrogen peroxide production system (hereinafter, sometimes referred to as "production system of the present invention") including a zeolite membrane module, a hydrogenation column, an oxidation column, and an extraction column.

In some embodiments, the zeolite membrane module has a zeolite membrane and a zeolite membrane permeate transfer line, the hydrogenation column has a hydrogenation catalyst and hydrogenation agent supply line and an unreacted hydrogenation agent discharge line, the oxidation column has an oxidant supply line and an unreacted oxidant discharge line, the extraction column has a water supply line and a hydrogen peroxide transfer line, the zeolite membrane module communicates with the hydrogenation column via a zeolite membrane treated working solution supply line, the hydrogenation column communicates with the oxidation column via a hydrogenated working solution supply line, the oxidation column communicates with the extraction column via an oxidized working solution supply line, and the extraction column communicates with the zeolite membrane module via a hydrogen peroxide extracted working solution supply line. Several modes of the hydrogen peroxide production system according to the present invention will be described below with reference to the drawings.

Fig. 1 shows a hydrogen peroxide production system a1 including a zeolite membrane module 101, a hydrogenation column 102, an oxidation column 103, and an extraction column 104. The zeolite membrane module 101 houses a zeolite membrane, and has a zeolite membrane permeate transfer line 105, the hydrogenation column 102 houses a hydrogenation catalyst, and has a hydrogenating agent supply line 106 and an unreacted hydrogenating agent discharge line 107, the oxidation column 103 has an oxidizing agent supply line 108 and an unreacted oxidizing agent discharge line 109, the extraction column 104 has a water supply line 110 and a hydrogen peroxide transfer line 111, the zeolite membrane permeate transfer line 105 has a cold trap 112, the cold trap 112 has a vacuum pumping line 113, the vacuum pumping line 113 has a vacuum pump 114, the zeolite membrane module 101 communicates with the hydrogenation column 102 through a zeolite membrane-treated working solution supply line 115, the hydrogenation column 102 communicates with the oxidation column 103 through a hydrogenated working solution supply line 116, the oxidation column 103 communicates with the extraction column 104 through an oxidized working solution supply line 117, and the extraction column 104 communicates with the zeolite membrane module 101 through a hydrogen peroxide-extracted working solution supply line 118.

The post-hydrogen peroxide-extraction working solution from the extraction column 104 enters the zeolite membrane module 101 through the post-hydrogen peroxide-extraction working solution supply line 118. The zeolite membrane module 101 is applied with a negative pressure by a vacuum pump 114, and the zeolite membrane permeate 119 that has permeated through the zeolite membrane is transported through the zeolite membrane permeate transport line 105. The zeolite membrane permeate transfer line 105 has a cold trap 112 where gas and liquid are separated, the liquid is transferred as zeolite membrane permeate 119 on through the zeolite membrane permeate transfer line 105, and the gas is evacuated through an evacuation line 113 as exhaust 120. The working solution which has not passed through the zeolite membrane is fed to the hydrogenation column 102 through the zeolite membrane-treated working solution supply line 115. The working solution is hydrogenated in the hydrogenation tower 102 in the presence of a hydrogenation catalyst by a hydrogenating agent 121 supplied from a hydrogenating agent supply line 106. Thereby, the anthraquinones contained in the working solution are changed to the anthrahydroquinones. Unreacted hydrogenating agent 122 is discharged from the unreacted hydrogenating agent discharge line 107. The hydrogenated working solution is fed to the oxidation tower 103 through the hydrogenated working solution supply line 116, and is oxidized by the oxidant 123 supplied from the oxidant supply line 108. Thereby, the anthrahydroquinones contained in the working solution are changed to anthraquinones, and hydrogen peroxide is generated. The unreacted oxidant 124 is discharged from the unreacted oxidant discharge line 109. The oxidized working solution enters the extraction tower 104 through the oxidized working solution supply line 117. In the extraction tower 104, the water 125 supplied from the water supply line 110 and the oxidizing working solution are mixed, and the hydrogen peroxide is extracted into the aqueous phase and taken out as the hydrogen peroxide water 126 from the hydrogen peroxide conveying line 111. The hydrogen peroxide-extracted working solution is passed through the hydrogen peroxide-extracted working solution supply line 118 again and subjected to treatment with the zeolite membrane module 101.

In the hydrogen peroxide production system of the present invention, the zeolite membrane permeate transfer line may communicate with the extraction column. The outline of the hydrogen peroxide production system of the present invention in which the zeolite membrane permeate transfer line communicates with the extraction column will be described with reference to fig. 2. In fig. 2, the same components as those in the hydrogen peroxide production system a1 shown in fig. 1 are denoted by the same reference numerals, and the description thereof is omitted.

In the hydrogen peroxide production system B2 shown in fig. 2, the zeolite membrane permeate transfer line 105 is connected to the extraction column 104, and the zeolite membrane module 101 and the extraction column 104 are connected through the zeolite membrane permeate transfer line 105.

In the hydrogen peroxide production system B2, the zeolite membrane permeate that has passed through the zeolite membrane of the zeolite membrane module 101 is supplied to the extraction column 104 through the zeolite membrane permeate transfer line 105. Since the zeolite membrane permeate contains a large amount of moisture, it facilitates the extraction of hydrogen peroxide in the extraction column 104. Therefore, not only the zeolite membrane permeate can be effectively utilized, but also the amount of water 125 supplied from the water supply line 110 can be saved, contributing to resource saving, reduction in running cost, and the like.

The production system of the present invention may further include a working solution regeneration device. In this embodiment, the zeolite membrane module and the working solution regeneration device may be communicated with each other through the zeolite membrane-treated working solution supply line, and the hydrogenation column and the working solution regeneration device may be communicated with each other through the regenerated working solution supply line. The outline of the hydrogen peroxide production system of the present invention having the working solution regeneration device will be described with reference to fig. 3. In fig. 3, the same components as those of the hydrogen peroxide production systems a1 to B2 shown in fig. 1 to 2 are denoted by the same reference numerals, and the description thereof will be omitted.

The hydrogen peroxide production system C3 shown in fig. 3 includes, in addition to the components of the hydrogen peroxide production system B2, a working solution regeneration device 301 having an alumina fixed bed, the zeolite membrane module 101 and the working solution regeneration device 301 are communicated by a zeolite membrane-treated working solution supply line 115, and the hydrogenation column 102 and the working solution regeneration device 301 are communicated by a regenerated working solution supply line 302.

The working solution treated by the zeolite membrane dehydrated by the zeolite membrane module 101 enters the working solution regeneration device 301 through the working solution supply line 115 after the zeolite membrane treatment. The anthraquinones are obtained by regenerating the by-products derived from the anthraquinones contained in the working solution by the alumina fixed bed provided in the working solution regenerating apparatus 301. The regenerated working solution obtained from the working solution regenerating device 301 is fed to the hydrogenation tower 102 through the regenerated working solution supply line 302 for producing hydrogen peroxide. The regenerated working solution has a higher concentration of anthraquinones having an oxygen peroxide generating ability than a working solution not subjected to the regeneration treatment, and has a high performance of oxygen peroxide per unit volume. Therefore, by providing the working solution regeneration device, not only the oxygen peroxide production efficiency of the oxygen peroxide production system can be improved, but also the amount of new (unused) anthraquinones to be added can be reduced.

One way of zeolite membrane module is shown in fig. 4. The zeolite membrane module a4 shown in fig. 4 is a vertical module having: a disk-shaped tube sheet 402 in which a plurality of tubular zeolite membrane elements 401 are arranged, and a standing tank 403 and a head space 404 partitioned by the tube sheet 402. The standing tank 403 has a post-hydrogen peroxide extraction working solution supply port 405 and a zeolite membrane treated working solution discharge port 406, and the head space 404 has a zeolite membrane permeated liquid discharge port 407. When the zeolite membrane module a4 is installed in any one of the hydrogen peroxide production systems a1 to C3, the post-hydrogen peroxide extraction working solution supply line 118 is connected to the post-hydrogen peroxide extraction working solution supply port 405, the zeolite membrane treated working solution supply line 115 is connected to the zeolite membrane treated working solution discharge port 406, and the zeolite membrane permeated liquid conveying line 105 is connected to the zeolite membrane permeated liquid discharge port 407.

The post-hydrogen peroxide-extraction working solution 408 enters the standing tank 403 from the post-hydrogen peroxide-extraction working solution supply port 405. Negative pressure is applied to the zeolite membrane element 401 from the zeolite membrane permeated liquid discharge port 407, and moisture contained in the working solution after hydrogen peroxide extraction permeates the zeolite membrane, enters the tube of the zeolite membrane element 401, passes through the head space 404, and is discharged as a zeolite membrane permeated liquid 409 from the zeolite membrane permeated liquid discharge port 407. On the other hand, the working solution from which moisture has been removed, which has been retained in the standing tank 403, is discharged as a zeolite membrane-treated working solution 410 from the zeolite membrane-treated working solution discharge port 406.

Another way of zeolite membrane module is shown in fig. 5. The zeolite membrane module B5 shown in fig. 5 is a horizontal module having: a disk-shaped tube sheet 502 in which a plurality of tubular zeolite membrane elements 501 are arranged, and a standing tank 503 and a head space 504 partitioned by the tube sheet 502. In the zeolite membrane module B5, a tube plate 511 is provided in the vicinity of the end portion of the zeolite membrane element 501 opposite to the head space 504 in order to support the zeolite membrane element 501. The still standing tank 503 has a post-hydrogen peroxide extraction working solution supply port 505 and a zeolite membrane treated working solution discharge port 506, and the head space 504 has a zeolite membrane permeated liquid discharge port 507. When the zeolite membrane module B5 is installed in the hydrogen peroxide production system a1 to C3, the post-hydrogen peroxide extraction working solution supply line 118 is connected to the post-hydrogen peroxide extraction working solution supply port 505, the zeolite membrane treated working solution supply line 115 is connected to the zeolite membrane treated working solution discharge port 506, and the zeolite membrane permeated liquid conveying line 105 is connected to the zeolite membrane permeated liquid discharge port 507.

The post-hydrogen peroxide-extraction working solution 508 enters the standing tank 503 through the post-hydrogen peroxide-extraction working solution supply port 505. Negative pressure is applied to the zeolite membrane element 501 from the zeolite membrane permeated liquid discharge port 507, and moisture contained in the working solution after hydrogen peroxide extraction permeates the zeolite membrane, enters the tube of the zeolite membrane element 501, passes through the head space 504, and is discharged as a zeolite membrane permeated liquid 509 from the zeolite membrane permeated liquid discharge port 507. On the other hand, the working solution from which the moisture has been removed, which has been retained in the standing tank 503, is discharged as a zeolite membrane-treated working solution 510 from the zeolite membrane-treated working solution discharge port 506.

The hydrogen peroxide production system of the present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention. For example, in the hydrogen peroxide production systems a1 to C3 shown in fig. 1 to 3, a line for supplying a new (unused) working solution may be connected to the hydrogenation column 102, the zeolite membrane-treated working solution supply line 115 (in the case of the hydrogen peroxide production systems a1 to B2), and/or the regenerated working solution supply line 302 (in the case of the hydrogen peroxide production system C3); in the hydrogen peroxide production system C3 shown in fig. 3, a cleaning tank (for example, a cleaning tank for alkali cleaning, a cleaning tank for acid cleaning, and/or a cleaning tank for water cleaning) for cleaning the working solution is provided before the working solution regeneration device; pumps or valves, branch lines, etc. are provided in at least 1 line as required.