Method for separating hydrogen peroxide and sulfuric acid

Abstract

The objective is to provide a method for separating hydrogen peroxide and sulfuric acid. [Solution] The method includes supplying a hydrogen peroxide-containing sulfuric acid aqueous solution to a distillation apparatus equipped with a first packing material at least 1.0 meter in length, and controlling the temperature at the bottom of the distillation apparatus to 65-71°C to generate a top discharge stream and a bottom discharge stream within the distillation apparatus. By using the above method, a hydrogen peroxide aqueous solution and a concentrated sulfuric acid aqueous solution can be obtained simultaneously.

Description

[Technical Field]

[0001] The present invention relates to a method for separating hydrogen peroxide and sulfuric acid, and more particularly to a method for separating sulfuric acid and hydrogen peroxide from a sulfuric acid solution containing hydrogen peroxide to form an aqueous hydrogen peroxide solution and a concentrated aqueous sulfuric acid solution, but the present invention is not limited thereto. [Background technology]

[0002] In semiconductor manufacturing processes, it is necessary to remove minute contaminants from wafer surfaces using high-purity chemicals to improve the yield of the final product and the quality and reliability of components. Taking the removal of organic contaminants as an example, the contaminant source is typically photoresist residue, but environmental factors (such as wall paint or pump fluid), plastic containers, and workers' clothing are also considered potential sources. Specifically, the powerful oxidizing and dehydrating properties of caroic acid, produced from sulfuric acid and hydrogen peroxide, can be used to break the carbon-hydrogen bonds in organic matter and achieve the goal of removing organic contaminants. However, sulfuric acid wastewater generated from caroic acid solutions used for wafer cleaning is the largest source of process wastewater. Furthermore, due to the continuous increase in production volume in the semiconductor industry in recent years, the amount of sulfuric acid wastewater generated has surged, and the industry urgently needed technologies and methods to efficiently recover or treat sulfuric acid wastewater to solve the problem of excess sulfuric acid wastewater.

[0003] Currently, the industry mainly treats the aforementioned waste sulfuric acid liquor by a catalytic method or a heating method. In the prior art, for example, Patent Document 1 discloses a method for recovering and reusing sulfuric acid from waste sulfuric acid containing an aqueous hydrogen peroxide solution, comprising the steps of: supplying sulfuric acid containing an aqueous hydrogen peroxide solution as a raw material; adding copper oxide (CuO) as a catalyst to trigger a chemical reaction and removing the aqueous hydrogen peroxide solution; allowing sulfuric acid and the catalyst to react chemically to release heat, and controlling the temperature by using a cooling device; adding hydrogen sulfide gas to chemically react metals in the metal ion-containing sulfuric acid generated by the chemical reaction between sulfuric acid and the catalyst to generate metal sulfides; and filtering the reaction product to obtain metal sulfides and high-purity dilute sulfuric acid. This method can completely remove the aqueous hydrogen peroxide solution and provide high-purity dilute sulfuric acid that can be directly used as a raw material for various chemical reactions, thereby achieving the objective of efficient recovery and reuse of waste sulfuric acid liquor.

[0004] In addition, in the prior art, for example, Patent Document 2 discloses a concentrating apparatus for dilute waste sulfuric acid liquor containing peroxide and aqueous hydrogen peroxide solution, which is a process of physically separating solutes and solvents in a solution. An aqueous solution containing solutes such as sulfuric acid, peroxide and aqueous hydrogen peroxide solution is heated (to 95°C) under vacuum, the peroxide and aqueous hydrogen peroxide solution, which are volatile solutes in the solution, are decomposed, evaporated together with water, and condensed by a condenser. At the same time, as the volume of the solution decreases, the concentration of the non-volatile solute sulfuric acid in the solution increases, so that a product acid of a specified concentration can be formed. [Prior Art Document] [Patent Document]

[0005] [Patent Document 1] Taiwan Patent Publication No. I849221 [Patent Document 2] Chinese Utility Model Publication No. CN205730408U [Summary of the Invention] [Problem to be Solved by the Invention]

[0006] Hydrogen peroxide and sulfuric acid are both important raw materials for industrial production, and in order to respond to the growing trend of sustainability management in global companies, recovering hydrogen peroxide and sulfuric acid from sulfuric acid wastewater containing hydrogen peroxide has become an important issue. However, the inventors of the present invention have found that many conventional methods for treating sulfuric acid wastewater containing hydrogen peroxide destroy and remove the hydrogen peroxide, making it impossible to recover hydrogen peroxide and sulfuric acid together, or that some of the recovered hydrogen peroxide contains relatively high concentrations of sulfuric acid, requiring further treatment, which complicates the process and increases costs. [Means for solving the problem]

[0007] To solve the above technical problems, the present invention provides a method for separating hydrogen peroxide and sulfuric acid, which includes introducing an aqueous sulfuric acid solution containing hydrogen peroxide into a distillation apparatus equipped with a first packing material at least 1.0 meter in length, and generating a top discharge stream and a bottom discharge stream within the distillation apparatus by controlling the temperature at the bottom of the distillation apparatus to 65-71°C.

[0008] According to some embodiments of the present invention, the pressure at the top of the distillation apparatus is 5 to 10 torr.

[0009] According to some embodiments of the present invention, the temperature at the top of the distillation apparatus is 4 to 45°C.

[0010] According to some embodiments of the present invention, the specific surface area of ​​the first filler is 200 to 750 m². 2 / m 3 That is the case.

[0011] According to some embodiments of the present invention, the first filler is a metal filler, a ceramic filler, a plastic filler, a graphite filler, or a combination thereof.

[0012] According to some embodiments of the present invention, the material of the first filler is a silicon alloy, a tantalum alloy, a zirconium alloy, or a combination thereof.

[0013] According to some embodiments of the present invention, the material of the first filler is polytetrafluoroethylene (PTFE), perfluoroalkoxy alkanes (PFA), fluoropolymer film (ethylene tetrafluoroethylene, ETFE), or a combination thereof.

[0014] According to some embodiments of the present invention, the hydrogen peroxide content of the top discharge stream is 20.0 to 35.0% by weight.

[0015] According to some embodiments of the present invention, the hydrogen peroxide content of the bottom discharge stream is less than 1.5% by weight.

[0016] According to some embodiments of the present invention, the hydrogen peroxide content of the bottom discharge stream is less than 1.0% by weight.

[0017] According to some embodiments of the present invention, the sulfuric acid content of the top discharge stream is less than 100 ppm.

[0018] According to some embodiments of the present invention, the sulfuric acid content of the top discharge stream is less than 10 ppm.

[0019] According to some embodiments of the present invention, the top of the distillation apparatus is provided with a condenser configured to control the temperature of the top discharge stream flowing through the condenser to 1 to 5°C.

[0020] According to some embodiments of the present invention, the distillation apparatus further comprises a reflux apparatus positioned corresponding to the top of the distillation apparatus.

[0021] According to some embodiments of the present invention, the reflux ratio of the distillation apparatus is 0 to 1.0.

[0022] According to some embodiments of the present invention, the sulfuric acid content of the top discharge stream is less than 1 ppm. [Effects of the Invention]

[0023] The advantage of the present invention is that by using the method for separating hydrogen peroxide and sulfuric acid of the present invention, an aqueous solution of hydrogen peroxide and a concentrated aqueous solution of sulfuric acid can be obtained simultaneously, thus aligning with the trend toward sustainable industrial development.

[0024] To facilitate a better understanding of the above-mentioned and other purposes, features, advantages, and embodiments of this application, they are described below with reference to the drawings. [Brief explanation of the drawing]

[0025] [Figure 1] This flowchart shows the steps for a method of separating hydrogen peroxide and sulfuric acid according to one embodiment of the present invention. [Figure 2] This is a schematic diagram of a distillation apparatus according to one embodiment of the present invention. [Figure 3] This is a schematic diagram of a distillation apparatus according to one embodiment of the present invention. [Modes for carrying out the invention]

[0026] Although the various features and components on the drawings are not depicted in actual dimensional proportions, they are drawn in the most appropriate manner to illustrate the specific features and components related to the present invention. Furthermore, similar components and members are represented by the same or similar reference numerals between different drawings.

[0027] To provide a more detailed and complete description of this application, the following is provided as an illustrative description of embodiments and specific examples of this application, but this is not the only way to implement or operate specific examples of the present invention. The various embodiments disclosed herein can be combined or substituted for each other under favorable circumstances, and other embodiments can be added to a single embodiment without requiring further description or explanation. The following descriptions include many specific details to help the reader fully understand the embodiments below. However, embodiments of the content disclosed herein can be implemented without these specific details. In this specification and the appended claims, unless the context indicates otherwise, "one" and "the" may be interpreted as plural.

[0028] The numerical ranges and parameters defining this invention are approximate values, but the relevant values ​​in the specific examples are presented here as accurately as possible. However, any values ​​inherently include the standard deviation due to the individual test method.

[0029] The methods disclosed herein will be described below using a series of operations or steps, but the order in which these operations or steps are presented should not be construed as limiting this application. For example, some operations or steps may be performed in a different order or concurrently with other steps. Furthermore, it is not necessary to perform all operations, steps, and features to implement the embodiments of this application. Note that each operation or step described herein may include multiple sub-operations or actions.

[0030] Please refer to Figures 1 and 2. The present invention provides a method for separating hydrogen peroxide and sulfuric acid, which may be sulfuric acid waste liquid generated from caroic acid solutions used in semiconductor manufacturing processes, and typically includes the steps of introducing a hydrogen peroxide-containing sulfuric acid aqueous solution containing 3.0 to 5.0% by weight of hydrogen peroxide and 60.0 to 65.0% by weight of sulfuric acid into a distillation apparatus 100 in step S110, and controlling the temperature of the bottom 110 of the distillation apparatus 100 to 65 to 71°C to generate a top discharge stream and a bottom discharge stream within the distillation apparatus. The supply temperature at which the hydrogen peroxide-containing sulfuric acid aqueous solution is introduced into the distillation apparatus 100 is not limited by the present invention.

[0031] Specifically, in step S110, the hydrogen peroxide-containing sulfuric acid aqueous solution is first placed into the waste liquid tank 20, and the waste liquid tank 20 and the distillation apparatus 100 are connected, for example, by a guide device, and the sulfuric acid waste liquid is guided into the distillation apparatus 100. The guide device may be, for example, the pump 30 and / or piping shown in Figure 2, and the type, number and arrangement of the pump 30 and piping can be adjusted according to actual needs and are not limited by the present invention.

[0032] Step S120 is the main step for separating hydrogen peroxide and sulfuric acid. Specifically, the hydrogen peroxide-containing sulfuric acid aqueous solution is supplied to the bottom 110 of the distillation apparatus 100, the pressure of the distillation apparatus 100 is controlled within a specific range using a vacuum device, and the temperature of the bottom 110 is controlled within a specific range using a heating device. At this time, the hydrogen peroxide-containing sulfuric acid aqueous solution generates two phases, gas and liquid. The gas contains hydrogen peroxide, sulfuric acid, and water. While the gas rises to the top 120 of the distillation apparatus 100, the hydrogen peroxide-containing sulfuric acid aqueous solution is continuously supplied from the top 120 to the bottom 110, and the gas comes into contact with the hydrogen peroxide-containing sulfuric acid aqueous solution, forming a gas-liquid contact on the surface of the first packing material 10. Because sulfuric acid has a relatively high boiling point, most of it remains in the liquid phase, and as a result, the sulfuric acid component in the gas flowing to the top 120 continuously decreases, so that the top discharge stream formed after the gas reaches the outlet at the top 120 contains a high content of hydrogen peroxide and a low content of sulfuric acid. The bottom discharge stream is led out from the outlet at the bottom 110, and as described above, the hydrogen peroxide is vaporized and discharged outside the distillation apparatus 100 from the top discharge stream, and the sulfuric acid gas that was originally rising continuously increases the liquid sulfuric acid component at the bottom of the column through gas-liquid contact and is supplied to the bottom 110, so that the bottom discharge stream may contain a high content of sulfuric acid and a low content of hydrogen peroxide.

[0033] According to some embodiments of the present invention, the temperature of the bottom 110 is 65 to 71°C, specifically, for example, 65°C, 66°C, 67°C, 68°C, 69°C, 70°C, 71°C, or a range between any two of the aforementioned values. Without being bound by any particular theory, the inventors have found that if the temperature of the bottom 110 is too high, hydrogen peroxide decomposes easily, and if it is too low, the amount of hydrogen peroxide vaporized is insufficient, resulting in a high hydrogen peroxide content in the bottom discharge stream, which adversely affects the separation and recovery of hydrogen peroxide and sulfuric acid.

[0034] According to some preferred embodiments of the present invention, with regard to further improving the separation efficiency of hydrogen peroxide and sulfuric acid, the pressure at the top 120 of the distillation apparatus 100 can be controlled to a range of 5 to 10 torr, for example, 5 torr, 6 torr, 7 torr, 8 torr, 9 torr, 10 torr, or any two of the aforementioned values. Alternatively or additionally, the temperature of the top 120 of the distillation apparatus 100 can be controlled to a range of 4 to 45°C, for example, 4°C, 5°C, 6°C, 7°C, 8°C, 9°C, 10°C, 11°C, 12°C, 13°C, 14°C, 15°C, 16°C, 17°C, 18°C, 19°C, 20°C, 21°C, 22°C, 23°C, 24°C, 25°C, 26°C, 27°C, 28°C, 29°C, 30°C, 31°C, 32°C, 33°C, 34°C, 35°C, 36°C, 37°C, 38°C, 39°C, 40°C, 41°C, 42°C, 43°C, 44°C, 45°C, or any two of the aforementioned values. Alternatively or additionally, the pressure at the bottom 110 of the distillation apparatus 100 can be controlled to a range of 15 to 20 torr, for example, 15 torr, 16 torr, 17 torr, 18 torr, 19 torr, 20 torr, or any two of the aforementioned values. According to another preferred embodiment of the present invention, the differential pressure between the bottom 110 pressure and the top 120 pressure is at least 10 torr, for example, at least 10 torr, at least 11 torr, or at least 12 torr. When the differential pressure is controlled to the above range, the separation efficiency of hydrogen peroxide and sulfuric acid can be improved while keeping the size of the distillation apparatus 100 reasonably small. If the differential pressure is too small, the size of the distillation apparatus 100 becomes too large to achieve the same separation efficiency, which increases costs.

[0035] According to some embodiments of the present invention, the length L of the first filler 10 is at least 1.0 meters, for example, at least 1.0 meters, at least 1.5 meters, at least 2.0 meters, at least 2.5 meters, at least 3.0 meters, at least 3.5 meters, at least 4.0 meters, at least 4.5 meters, at least 5.0 meters, at least 5.5 meters, at least 6.0 meters, at least 6.5 meters, at least 7.0 meters, at least 7.5 meters, at least 8.0 meters, at least 8.5 meters, at least 9.0 meters, at least 9.5 meters, at least 10.0 meters, or at least 10.5 meters. Without being bound by any particular theory, if the length L of the first filler is too short, gas is more likely to carry more sulfuric acid to the top 120, resulting in a high sulfuric acid content in the top discharge stream, which is disadvantageous for the separation of hydrogen peroxide and sulfuric acid.

[0036] According to some embodiments of the present invention, the specific surface area of the first filler 10 is 200 to 750 m 2 / m 3 , for example, 200 m 2 / m 3 , 225 m 2 / m 3 , 250 m 2 / m 3 , 275 m 2 / m 3 , 300 m 2 / m 3 , 325 m 2 / m 3 , 350 m 2 / m 3 , 375 m 2 / m 3 , 400 m 2 / m 3 , 425 m 2 / m 3 , 450 m 2 / m 3 , 475 m 2 / m 3 , 500 m 2 / m 3 , 525 m 2 / m 3 , 550 m 2 / m 3 , 575m 2 / m 3 , 600m 2 / m 3 , 625m 2 / m 3 , 650m 2 / m 3 , 675m 2 / m 3 , 700m 2 / m 3 , 725m 2 / m 3 , 750m 2 / m 3 Alternatively, it is a range between any two of the aforementioned values. If the specific surface area of ​​the first packing material 10 is controlled within the above range, the separation of hydrogen peroxide and sulfuric acid can be further improved.

[0037] According to some embodiments of the present invention, the type of first packing 10 is, for example, a bulk packing or a structured packing, preferably a structured packing composed of packings with different geometric shapes and wave angles. The geometric shape or wave angle can be adjusted according to actual needs; for example, a structured packing with a wave angle of 30° can be used to reduce pressure loss, or a structured packing with a wave angle of 45° can be used to improve mass transfer properties, or a structured material with a mesh-like geometric shape can be used to reduce pressure loss and improve separation efficiency.

[0038] According to some embodiments of the present invention, the first filler 10 may be, for example, a metal filler, a ceramic filler, a plastic filler, a graphite filler, or a combination thereof. More specifically, the material of the metal filler may be stainless steel, nickel alloy (such as Monel alloy), copper metal and its alloys, titanium metal and its alloys, silicon alloy, tantalum alloy, zirconium alloy, or a combination thereof, preferably silicon alloy, tantalum alloy, zirconium alloy, or a combination thereof. The material of the plastic filler may be, for example, polyvinyl chloride (PVC), polyethylene (PE), polypropylene (PP), polyvinylidene difluoride (PVDF), polytetrafluoroethylene (PTFE), perfluoroalkoxy alkanes (PFA), fluoropolymer film (ETFE), or a combination thereof, preferably polytetrafluoroethylene, perfluoroalkoxy alkanes, fluoropolymer film, or a combination thereof.

[0039] According to some preferred embodiments of the present invention, the heating device specifically used to control the temperature of the bottom 110 within the above-mentioned specific range is, for example, the reboiler 50 shown in Figure 2, and by circulating the hydrogen peroxide-containing sulfuric acid aqueous solution through the reboiler 50 in conjunction with the pump 31, the solution can be heated evenly and uniformly, thereby improving the vaporization efficiency.

[0040] According to some embodiments of the present invention, the distillation apparatus 100 is equipped with a cooling device 40, and when the bottom discharge stream is discharged from the distillation apparatus 100, the cooling device 40 is used to lower the temperature of the bottom discharge stream, allowing the bottom discharge stream to be contained in a first recovery tank 21, thereby facilitating the storage and recovery of the bottom discharge stream. According to another embodiment of the present invention, the distillation apparatus 100 is equipped with a condenser 41, and when the top discharge stream is discharged from the distillation apparatus 100, the condenser 41 is used to condense the gas in the top discharge stream into a liquid, allowing the top discharge stream to be contained in a second recovery tank 22, thereby facilitating the storage and recovery of the top discharge stream. Preferably, the temperature of the top discharge stream flowing through the condenser 41 is in the range of 1 to 5°C, for example, 1°C, 2°C, 3°C, 4°C, 5°C, or any two of the aforementioned values. The type and number of cooling devices 40 and condensers 41 can be adjusted according to actual needs and are not limited by the present invention.

[0041] According to some embodiments of the present invention, the hydrogen peroxide content of the top discharge stream is 20.0 to 35.0% by weight of the total weight of the top discharge stream, for example, 20.0%, 20.5%, 20.6%, 21.0%, 22.0%, 23.0%, 23.2%, 24.0%, 25.0%, 26.0%, 27.0%, 28.0%, 29.0%, 30.0%, 31.0%, 31.3%, 32.0%, 33.0%, 34.0%, 35.0%, or in the range between any two of the aforementioned values, preferably 20.0 to 32.0% by weight.

[0042] According to some embodiments of the present invention, the hydrogen peroxide content of the bottom discharge stream is less than 1.5% by weight of the total weight of the bottom discharge stream, for example, less than 1.5%, less than 1.4%, less than 1.3%, less than 1.2%, less than 1.1%, less than 1.0%, less than 0.9%, less than 0.8%, less than 0.7%, less than 0.6%, less than 0.5%, less than 0.4%, less than 0.3%, less than 0.2%, or less than 0.1%, preferably less than 1.0% by weight. Furthermore, the hydrogen peroxide content of the bottom discharge stream can be reduced to 800 ppm or less by a certain method, for example, 800 ppm or less, 600 ppm or less, 400 ppm or less, 200 ppm or less, 150 ppm or less, 100 ppm or less, or 50 ppm or less, preferably reduced to 50 ppm or less. The method involves reducing the hydrogen peroxide content in the bottom discharge stream by, for example, using hydrogen chloride to react with hydrogen peroxide in the bottom discharge stream to produce chlorine and water, or by using a metal oxide catalyst to decompose the hydrogen peroxide in the bottom discharge stream into oxygen and water at a specific temperature, or by heating the bottom discharge stream to a high temperature and irradiating it with ultraviolet light to decompose the contained hydrogen peroxide into oxygen and water.

[0043] According to some embodiments of the present invention, the sulfuric acid content of the top discharge stream is less than 100 ppm relative to the total weight of the top discharge stream, for example, less than 100 ppm, less than 90 ppm, less than 80 ppm, less than 70 ppm, less than 60 ppm, less than 50 ppm, less than 40 ppm, less than 30 ppm, less than 20 ppm, or less than 10 ppm, preferably less than 10 ppm.

[0044] Please refer to Figures 1 and 3 together. The top of the distillation apparatus 200 may further include a reflux device 60 positioned corresponding to the top 220 of the distillation apparatus 200. Specifically, in step S120, the reflux device 60 is used to reflux a portion of the top discharge stream into the distillation apparatus 200, where the sulfuric acid in a portion of the top discharge stream comes into contact with the rising sulfuric acid gas, causing gas-liquid contact on the surface of the first packing 10, which further absorbs the sulfuric acid components in the gas into a liquid, which is then supplied together to the bottom 210, thereby lowering the sulfuric acid content of the refluxed top discharge stream and improving the separation efficiency of hydrogen peroxide and sulfuric acid. According to another embodiment of the present invention, the distillation apparatus 200 further includes a second packing provided on top of the first packing 10, which can further improve mass transfer properties. The type, length, and specific surface area of ​​the second packing can be adjusted according to actual needs and are not limited by the present invention. According to some preferred embodiments of the present invention, the reflux ratio of the reflux apparatus 60 is in the range of 0 to 1.0, for example, 0, 0.2, 0.4, 0.6, 0.8, 1.0, or any two of the aforementioned values. If the reflux ratio is too high, more hydrogen peroxide may be carried to the bottom of the distillation apparatus 200, which may adversely affect the separation of hydrogen peroxide and sulfuric acid. According to another preferred embodiment of the present invention, the sulfuric acid content of the refluxed top discharge stream is less than 1 ppm. [Examples]

[0045] The present invention will be described in detail below with reference to specific examples. However, it should be understood that these specific examples are intended to aid in understanding the present invention and are not intended to limit the scope of the invention in any way.

[0046] The following describes the separation methods for hydrogen peroxide and sulfuric acid used in the examples and comparative examples.

[0047] (Example 1) A hydrogen peroxide-containing sulfuric acid aqueous solution is introduced into a distillation apparatus, with the temperature (supply temperature) controlled to 30°C. The composition of the hydrogen peroxide-containing sulfuric acid aqueous solution is 60% by weight sulfuric acid, 3% by weight hydrogen peroxide, and 37% by weight water. The distillation apparatus is as shown in Figure 2, with a bottom temperature of 70°C and a bottom pressure of 20 torr, a top temperature of 43°C and a top pressure of 10 torr, thereby generating a top discharge stream and a bottom discharge stream within the distillation apparatus. A first packing material using structured packing material is provided in the distillation apparatus, with a length of 10.0 meters and a specific surface area of ​​225 m². 2 / m 3 That was the case.

[0048] (Example 2) A hydrogen peroxide-containing sulfuric acid aqueous solution is introduced into a distillation apparatus, with the temperature (supply temperature) controlled to 30°C. The composition of the hydrogen peroxide-containing sulfuric acid aqueous solution is 60% by weight sulfuric acid, 5% by weight hydrogen peroxide, and 35% by weight water. The distillation apparatus is as shown in Figure 2, with a bottom temperature of 65°C, a bottom pressure of 15 torr, a top temperature of 33°C, and a top pressure of 5 torr. This generates a top discharge stream and a bottom discharge stream within the distillation apparatus. A first packing material using regular packing material is provided in the distillation apparatus, with a length of 5.0 meters and a specific surface area of ​​225 m². 2 / m 3 That was the case.

[0049] (Example 3) A hydrogen peroxide-containing sulfuric acid aqueous solution is introduced into a distillation apparatus, with the temperature (supply temperature) controlled to 30°C. The composition of the hydrogen peroxide-containing sulfuric acid aqueous solution is 60% by weight sulfuric acid, 3% by weight hydrogen peroxide, and 37% by weight water. The distillation apparatus is as shown in Figure 3 and is further equipped with a reflux device with a reflux ratio of 0.1. The temperature at the bottom of the distillation apparatus is 71°C, the pressure at the bottom is 20 torr, the temperature at the top is 13°C, and the pressure at the top is 10 torr. This generates a top discharge stream and a bottom discharge stream within the distillation apparatus. The distillation apparatus is provided with a first packing material using a regular packing material, the length of the first packing material is 10.5 meters, and the specific surface area is 207 m². 2 / m 3 That was the case.

[0050] (Example 4) A hydrogen peroxide-containing sulfuric acid aqueous solution is introduced into a distillation apparatus, with the temperature (supply temperature) controlled to 30°C. The composition of the hydrogen peroxide-containing sulfuric acid aqueous solution is 60% by weight sulfuric acid, 5% by weight hydrogen peroxide, and 35% by weight water. The distillation apparatus is as shown in Figure 3 and is further equipped with a reflux device with a reflux ratio of 1.0. The temperature at the bottom of the distillation apparatus is 70°C, the pressure at the bottom is 15 torr, the temperature at the top is 4°C, and the pressure at the top is 5 torr. This generates a top discharge stream and a bottom discharge stream within the distillation apparatus. The distillation apparatus is provided with a first packing material using regular packing material, the length of the first packing material is 10.0 meters, and the specific surface area is 225 m². 2 / m 3 That was the case.

[0051] (Example 5) A hydrogen peroxide-containing sulfuric acid aqueous solution is introduced into a distillation apparatus, with the temperature (supply temperature) controlled to 30°C. The composition of the hydrogen peroxide-containing sulfuric acid aqueous solution is 60% by weight sulfuric acid, 4% by weight hydrogen peroxide, and 36% by weight water. The distillation apparatus is as shown in Figure 2. The temperature at the bottom of the distillation apparatus is 65°C, the pressure at the bottom is 15 torr, the temperature at the top is 39°C, and the pressure at the top is 5 torr. This generates a top discharge stream and a bottom discharge stream within the distillation apparatus. A first packing material using regular packing material is provided in the distillation apparatus, with a length of 1.0 meter and a specific surface area of ​​225 m². 2 / m 3 That was the case.

[0052] (Comparative Example 1) The method was carried out based on the prior art (Patent Document 2), and no packing material was provided in the distillation apparatus. A hydrogen peroxide-containing sulfuric acid aqueous solution was introduced into the distillation apparatus, and the temperature (supply temperature) was controlled to 30°C. The composition of the hydrogen peroxide-containing sulfuric acid aqueous solution was 60% by weight sulfuric acid, 5% by weight hydrogen peroxide, and 35% by weight water. The temperature at the bottom of the distillation apparatus was 95°C, the pressure at the bottom was 8 torr, the temperature at the top was less than 45°C, and the pressure at the top was 8 torr, thereby generating a top discharge stream and a bottom discharge stream within the distillation apparatus.

[0053] (Comparative Example 2) A hydrogen peroxide-containing sulfuric acid aqueous solution is introduced into a distillation apparatus, with the temperature (supply temperature) controlled to 30°C. The composition of the hydrogen peroxide-containing sulfuric acid aqueous solution is 60% by weight sulfuric acid, 5% by weight hydrogen peroxide, and 35% by weight water. The distillation apparatus is as shown in Figure 3 and is further equipped with a reflux device with a reflux ratio of 1.0. The temperature at the bottom of the distillation apparatus is 64°C, the pressure at the bottom is 20 torr, the temperature at the top is 15°C, and the pressure at the top is 10 torr. This generates a top discharge stream and a bottom discharge stream within the distillation apparatus. The distillation apparatus is provided with a first packing material using regular packing material, the length of the first packing material is 10.5 meters, and the specific surface area is 225 m². 2 / m 3 That was the case.

[0054] (Comparative Example 3) A hydrogen peroxide-containing sulfuric acid aqueous solution is introduced into a distillation apparatus, with the temperature (supply temperature) controlled to 30°C. The composition of the hydrogen peroxide-containing sulfuric acid aqueous solution is 60% by weight sulfuric acid, 5% by weight hydrogen peroxide, and 35% by weight water. The distillation apparatus is as shown in Figure 3 and is further equipped with a reflux device with a reflux ratio of 2.0. The temperature at the bottom of the distillation apparatus is 72°C, the pressure at the bottom is 15 torr, the temperature at the top is 10°C, and the pressure at the top is 5 torr. This generates a top discharge stream and a bottom discharge stream within the distillation apparatus. The distillation apparatus is provided with a first packing material using regular packing material, the length of the first packing material is 10.5 meters, and the specific surface area is 225 m². 2 / m 3 That was the case.

[0055] (Comparative Example 4) A hydrogen peroxide-containing sulfuric acid aqueous solution is introduced into a distillation apparatus, with the temperature (supply temperature) controlled to 30°C. The composition of the hydrogen peroxide-containing sulfuric acid aqueous solution is 60% by weight sulfuric acid, 5% by weight hydrogen peroxide, and 35% by weight water. The distillation apparatus is as shown in Figure 2. The temperature at the bottom of the distillation apparatus is 71°C, the pressure at the bottom is 7 torr, the temperature at the top is 32°C, and the pressure at the top is 5 torr. This generates a top discharge stream and a bottom discharge stream within the distillation apparatus. A first packing material using regular packing material is provided in the distillation apparatus, the length of the first packing material is 0.5 meters, and the specific surface area is 128 m². 2 / m 3 That was the case.

[0056] Table 1 below shows the sulfuric acid content and hydrogen peroxide content of the top discharge stream and the hydrogen peroxide content and sulfuric acid content of the bottom discharge stream for Examples 1 to 5 and Comparative Examples 1 to 4, which were carried out based on the above method.

[0057] [Table 1]

[0058] [Table 2] The first filler uses a regular filler, and its material is polytetrafluoroethylene (PTFE).

[0059] According to Table 1, in Examples 1 to 5, where the length of the first packing was simultaneously controlled to at least 1.0 meter and the temperature at the bottom of the distillation apparatus was controlled to 65-71°C, the sulfuric acid content in the bottom discharge stream was high (e.g., greater than 68.0% by weight), the hydrogen peroxide content was extremely low (e.g., less than 1.5% by weight), the hydrogen peroxide content in the top discharge stream was high (e.g., greater than 20.0% by weight), and the sulfuric acid content was extremely low (e.g., less than 10 ppm). In other words, a concentrated sulfuric acid aqueous solution was obtained, along with a hydrogen peroxide aqueous solution.

[0060] Conversely, in Comparative Examples 1 to 4, where the first packing material was not provided, or where the length of the first packing material and the temperature at the bottom of the distillation apparatus were not controlled within the above conditions and range, it was found that high-purity sulfuric acid aqueous solution and hydrogen peroxide aqueous solution could not be obtained simultaneously. Specifically, Comparative Example 1 was carried out based on the method disclosed in the prior art (Patent Document 2), and because the temperature at the bottom of the distillation apparatus in Comparative Example 1 was too high, hydrogen peroxide decomposed easily, resulting in a low hydrogen peroxide content in the top discharge stream. Also, because the first packing material was not provided, the rising gas carried more sulfuric acid to the top of the distillation apparatus, resulting in a high sulfuric acid content in the top discharge stream. In the case of Comparative Example 2, because the temperature at the bottom of the distillation apparatus was too low, the amount of hydrogen peroxide vaporized was insufficient, resulting in a high hydrogen peroxide content in the bottom discharge stream. In the case of Comparative Example 3, because the temperature at the bottom of the distillation apparatus was too high, hydrogen peroxide decomposed easily, resulting in a low hydrogen peroxide content in the top discharge stream. Furthermore, because the reflux ratio exceeded the recommended range, more hydrogen peroxide was returned to the bottom of the distillation apparatus, resulting in an excessively high hydrogen peroxide content in the bottom discharge stream. In Comparative Example 4, the length of the first packing was too short, causing the rising gas to carry a large amount of sulfuric acid to the top of the distillation apparatus, resulting in a high sulfuric acid content in the top discharge stream.

[0061] Therefore, by simultaneously controlling the length of the first packing to at least 1.0 meter and controlling the temperature at the bottom of the distillation apparatus to 65-71°C, a concentrated sulfuric acid aqueous solution and a hydrogen peroxide aqueous solution can be obtained at the same time, thus solving the aforementioned technical problem.

[0062] All ranges provided herein are intended to include each specific range within a given range, and combinations of subranges between given ranges. Furthermore, any range expressed herein includes the endpoint unless otherwise specified. Thus, the range 1–5 includes, in particular, 1, 2, 3, 4, and 5, and subranges such as 2–5, 3–5, 2–3, 2–4, and 1–4.

[0063] All publications and patent applications cited herein are incorporated herein by reference, and for all purposes, individual publications or patent applications are specifically and individually indicated as being incorporated herein by reference. In the event of any conflict between this Specified and any publication or patent application incorporated herein by reference, this Specified shall prevail. [Explanation of Symbols]

[0064] 10. First Filling 20 Waste liquid tanks 21. First recovery tank 22 Second Recovery Tank 30, 31 Pumps 40 Cooling device 41 Condenser 50 Reboilers 60 Reflux apparatus 100, 200 distillation apparatus 110, 210 bottom 120, 220 top L Length S110, S120 process

Claims

1. Introducing a sulfuric acid aqueous solution containing hydrogen peroxide into a distillation apparatus equipped with a first packing material at least 1.0 meter in length, By controlling the pressure at the top of the distillation apparatus to 5 to 10 torr, the temperature at the top of the distillation apparatus to 4 to 45°C, the pressure at the bottom of the distillation apparatus to 15 to 20 torr, and the temperature at the bottom of the distillation apparatus to 65 to 71°C, a top discharge stream and a bottom discharge stream are generated within the distillation apparatus. A method for separating hydrogen peroxide and sulfuric acid containing [unspecified substance].

2. The specific surface area of ​​the first filler is 200 to 225 m². ２ / m ３ The method according to claim 1.

3. The method according to claim 1, wherein the first filler is a metal filler, a ceramic filler, a plastic filler, a graphite filler, or a combination thereof.

4. The method according to claim 3, wherein the material of the first filler is a silicon alloy, a tantalum alloy, a zirconium alloy, or a combination thereof.

5. The method according to claim 3, wherein the material of the first filler is polytetrafluoroethylene (PTFE), perfluoroalkoxyalkane (PFA), fluoropolymer film (ETFE), or a combination thereof.

6. The method according to claim 1, wherein the hydrogen peroxide content of the top discharge stream is 20.0 to 35.0% by weight.

7. The method according to claim 1, wherein the hydrogen peroxide content of the bottom discharge stream is less than 1.5% by weight.

8. The method according to claim 7, wherein the hydrogen peroxide content of the bottom discharge stream is less than 1.0% by weight.

9. The method according to claim 1, wherein the sulfuric acid content of the top discharge stream is less than 100 ppm.

10. The method according to claim 9, wherein the sulfuric acid content of the top discharge stream is less than 10 ppm.

11. The method according to claim 1, wherein the top of the distillation apparatus is equipped with a condenser, and the temperature of the top discharge stream flowing through the condenser is controlled to 1 to 5°C.

12. The method according to any one of claims 1 to 11, wherein the distillation apparatus further comprises a reflux device positioned corresponding to the top of the distillation apparatus.

13. The method according to claim 12, wherein the reflux ratio of the distillation apparatus is 0 to 1.

0.

14. The method according to claim 12, wherein the sulfuric acid content of the top discharge stream is less than 1 ppm.

Images