Method for separating hydrogen peroxide and sulfuric acid

Abstract

The invention relates to a method for separating hydrogen peroxide and sulfuric acid. The method comprises the following steps: feeding a sulfuric acid aqueous solution containing hydrogen peroxide into a distillation device; and controlling the temperature of the bottom of the distillation apparatus to 65 to 71 DEG C so as to produce a top discharge stream and a bottom discharge stream in the distillation apparatus; wherein the distillation device is provided with a first filler, and the length of the first filler is at least 1.0 m. By using the method, the hydrogen peroxide aqueous solution and the concentrated sulfuric acid aqueous solution can be obtained at the same time.

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 in a sulfuric acid solution containing hydrogen peroxide to form a hydrogen peroxide aqueous solution and a concentrated sulfuric acid aqueous solution, but the present invention is not limited thereto. [Background technology]

[0002] In the semiconductor manufacturing process, in order to improve the yield of the final product and the quality and reliability of the components, high-purity chemicals are required to remove fine contamination on the surface of the wafer. Taking the removal of organic pollutants as an example, the source of pollution is usually from the residue of the photoresist. In addition, the environment (such as paint on the wall or oil from the pump, etc.), plastic containers and workers' clothes are also possible sources; specifically, the strong oxidizing and dehydrating properties of peroxide formed by sulfuric acid and hydrogen peroxide can destroy the carbon-hydrogen bonds of organic matter to achieve the purpose of removing organic pollutants. However, the sulfuric acid waste liquid formed by the peroxide acid solution for cleaning the wafer has become the largest source of process waste liquid. In addition, due to the continuous increase in production in the semiconductor industry in recent years, the output of sulfuric acid waste liquid has increased rapidly. Therefore, the industry urgently needs a technology and method that can efficiently recover or treat sulfuric acid waste liquid to solve the problem of excess sulfuric acid waste liquid.

[0003] At present, the industry mainly uses a catalytic method or a heating method to treat the aforementioned sulfuric acid waste liquid. Prior art, such as Taiwan Patent Invention Patent Announcement No. I849221, discloses a method for recovering and reusing sulfuric acid from waste sulfuric acid containing hydrogen peroxide solution, which includes the following steps: feeding sulfuric acid containing hydrogen peroxide solution as a raw material; adding metal copper oxide (CuO) as a catalyst to carry out a chemical reaction to remove the hydrogen peroxide solution; sulfuric acid and the catalyst undergo a chemical reaction to produce an exothermic phenomenon, and a cooling device is used to control the temperature; adding hydrogen sulfide gas to react the metal in the sulfuric acid containing metal ions generated by the chemical reaction between sulfuric acid and the catalyst to produce metal sulfides; and filtering the reaction product to obtain metal sulfides and high-purity dilute sulfuric acid. This method can completely remove the hydrogen peroxide solution and provide high-purity dilute sulfuric acid, which can be directly used as a raw material for a variety of chemical reactions, thereby achieving the purpose of high-efficiency recovery and reuse of sulfuric acid waste liquid.

[0004] In addition, prior art such as Chinese utility model patent No. CN205730408U discloses a device for concentrating dilute sulfuric acid waste liquid containing peroxide and hydrogen peroxide aqueous solution, which is a physical process for separating the solute and the solvent in the solution: the aqueous solution containing solutes such as sulfuric acid, peroxide and hydrogen peroxide aqueous solution is heated under a vacuum state (95°C) to decompose the volatile solutes peroxide and hydrogen peroxide aqueous solution in the solution, and evaporate together with water, and condense through 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, thereby forming a finished acid of a specified concentration. [Summary of the invention]

[0005] Hydrogen peroxide and sulfuric acid are both important raw materials for industrial production, and due to the development trend of sustainable management of international enterprises, the recovery of hydrogen peroxide and sulfuric acid from sulfuric acid waste liquid containing hydrogen peroxide is an important issue. However, the inventors have found that the conventional methods for treating sulfuric acid waste liquid containing hydrogen peroxide mostly destroy and remove hydrogen peroxide, but fail to recover hydrogen peroxide and sulfuric acid at the same time; or, the recovered hydrogen peroxide contains a higher concentration of sulfuric acid, which requires further treatment, making the process complicated and increasing the cost.

[0006] In order to solve the above technical problems, the present invention provides a method for separating hydrogen peroxide and sulfuric acid, which comprises: introducing an aqueous sulfuric acid solution containing hydrogen peroxide into a distillation device; and controlling the The temperature of the bottom of the distillation apparatus is 65 to 71° C., so as to generate a top discharge stream and a bottom discharge stream in the distillation apparatus; wherein the distillation apparatus is provided with a first packing, and the length of the first packing is at least 1.0 meter.

[0007] According to some embodiments of the present invention, the pressure at the top of the distillation apparatus is 5 to 10 torr.

[0008] According to some embodiments of the present invention, the temperature at the top of the distillation apparatus is 4 to 45°C.

[0009] According to some embodiments of the present invention, the specific surface area of ​​the first filler is 200 to 750 m 2 / m 3 .

[0010] 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.

[0011] According to some embodiments of the present invention, the material of the first filler is silicon alloy, tantalum alloy, zirconium alloy or a combination thereof.

[0012] According to some embodiments of the present invention, the material of the first filler is polytetrafluoroethylene (PTFE), perfluoroalkoxyalkanes (PFA, also known as perfluoroalkoxy alkyl ether), fluoroplastic film (Ethylene tetrafluoroethylene, ETFE, also known as ethylene-tetrafluoroethylene copolymer) or a combination thereof.

[0013] According to some embodiments of the present invention, the hydrogen peroxide content of the top discharge stream is 20.0 to 35.0 wt.%.

[0014] According to some embodiments of the present invention, the hydrogen peroxide content of the bottom discharge stream is less than 1.5 wt.%.

[0015] According to some embodiments of the present invention, the hydrogen peroxide content of the bottom discharge stream is less than 1.0 wt.%.

[0016] According to some embodiments of the present invention, the sulfuric acid content of the top discharge stream is less than 100 ppm.

[0017] According to some embodiments of the present invention, the sulfuric acid content of the top discharge stream is less than 10 ppm.

[0018] According to some embodiments of the present invention, the top of the distillation device comprises a condensing device, which is configured to control the temperature of the top discharge stream flowing through the condensing device to be 1 to 5°C.

[0019] According to some embodiments of the present invention, the distillation apparatus further comprises a reflux device, which is disposed corresponding to the top of the distillation apparatus.

[0020] According to some embodiments of the present invention, the reflux ratio of the distillation apparatus is 0 to 1.0.

[0021] According to some embodiments of the present invention, the sulfuric acid content of the top discharge stream is less than 1 ppm.

[0022] The advantage of the present invention is that by using the method for separating hydrogen peroxide and sulfuric acid of the present invention, a hydrogen peroxide aqueous solution and a concentrated sulfuric acid aqueous solution can be obtained simultaneously, so as to meet the trend of sustainable industrial development.

Brief Description of the Drawings

[0023] To make the above and other purposes, features, advantages and embodiments of the present application more understandable, the following are the descriptions of the accompanying drawings:

[0024] Figure 1 FIG. 4 is a flow chart of the steps of a method for separating hydrogen peroxide and sulfuric acid according to an embodiment of the present invention.

[0025] Figure 2 is a schematic diagram of a distillation apparatus according to an embodiment of the present invention.

[0026] Figure 3 is a schematic diagram of a distillation apparatus according to an embodiment of the present invention.

[0027] The features and components in the figures are not drawn to scale, but are drawn in the manner intended to present the specific features and components related to the invention in the best possible way. In addition, the same or similar component symbols are used to refer to the same or similar components and parts in different figures. [Specific implementation method]

[0028] In order to make the description of the present application more detailed and complete, the following is an illustrative description of the implementation methods and specific embodiments of the present application, but this is not the only form of implementing or applying the specific embodiments of the present application. The various embodiments disclosed below can be combined or replaced with each other in beneficial situations, and other embodiments can be added to one embodiment without further recording or explanation. In the following description, many specific details will be described in detail so that the reader can fully understand the following embodiments; however, the embodiments of the contents disclosed in this application can be practiced without such specific details. In addition, in this specification and the scope of the attached patent application, unless the context otherwise states, "one" and "the" may also be interpreted as plural.

[0029] Although the numerical ranges and parameters used to define the present invention are approximate values, the relevant numerical values ​​in the specific embodiments have been presented as precisely as possible. However, any numerical value inherently contains inevitably standard deviations caused by individual testing methods.

[0030] Although a series of operations or steps are used below to illustrate the method disclosed herein, the order shown in these operations or steps should not be construed as a limitation of the present application. For example, certain operations or steps can be performed in different orders or simultaneously with other steps. In addition, it is not necessary to perform all operations, steps, features to realize the embodiment of the present application. In addition, each operation or step described here can include several sub-steps or actions.

[0031] Please read together Figure 1 and Figure 2The present invention provides a method for separating hydrogen peroxide and sulfuric acid, comprising step S110: introducing an aqueous sulfuric acid solution containing hydrogen peroxide into a distillation device 100; and step S120: controlling the temperature of the bottom 110 of the distillation device 100 to be 65 to 71° C., so as to generate a top discharge stream and a bottom discharge stream in the distillation device, wherein the aqueous sulfuric acid solution containing hydrogen peroxide may be, for example, sulfuric acid waste liquid formed by a Carrot acid solution used in a semiconductor manufacturing process, which generally contains 3.0 to 5.0 wt.% of hydrogen peroxide and 60.0 to 65.0 wt.% of sulfuric acid, wherein the feed temperature of the aqueous sulfuric acid solution containing hydrogen peroxide introduced into the distillation device 100 is not limited by the present invention.

[0032] Specifically, in step S110, the sulfuric acid aqueous solution containing hydrogen peroxide may be placed in a waste liquid barrel 20. The waste liquid barrel 20 and the distillation device 100 may be connected, for example, by a guide device, so that the sulfuric acid waste liquid can be guided into the distillation device 100. The guide device may be, for example, Figure 2 The pumps 30 and / or pipelines shown, and the types, quantities and configurations of the pumps 30 and pipelines can be adjusted according to actual needs and are not limited by the present invention.

[0033] Step S120 is a main step for separating hydrogen peroxide and sulfuric acid. Specifically, the aqueous sulfuric acid solution containing hydrogen peroxide is fed into the bottom 110 of the distillation device 100, and the pressure of the distillation device is controlled within a specific range by a vacuum device, and then the temperature of the bottom 110 is controlled within a specific range by a heating device. At this time, the aqueous sulfuric acid solution containing hydrogen peroxide produces a gas and a liquid two-phase state, wherein the gas contains hydrogen peroxide, sulfuric acid and water. In the process of the gas rising to the top 120 of the distillation device 100, the aqueous sulfuric acid solution containing hydrogen peroxide is continuously fed from the top 120 into the bottom 110, and the gas contacts the aqueous sulfuric acid solution containing hydrogen peroxide, and gas-liquid contact occurs on the surface of the first filler 10, wherein sulfuric acid mostly remains in the liquid phase due to its high boiling point, resulting in a continuous decrease in the sulfuric acid component in the gas flowing to the top 120, and the top discharge stream formed after the gas reaches the discharge port of the top 120 contains a higher content of hydrogen peroxide and a lower content of sulfuric acid; and the discharge port of the bottom 110 leads out the bottom discharge stream, and as mentioned above, due to Page 6 of 17 pages (Instruction Manual) The hydrogen peroxide is vaporized and discharged from the distillation device 100 through the top outlet stream, and the sulfuric acid component of the originally rising sulfuric acid gas to the bottom liquid is continuously increased due to gas-liquid contact and fed into the bottom 110, so the bottom outlet stream can include a higher content of sulfuric acid and a lower content of hydrogen peroxide.

[0034] 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 foregoing values. Without being limited by a particular theory, the present inventors have found that if the temperature of the bottom 110 is too high, hydrogen peroxide will be easily decomposed, while if it is too low, the amount of hydrogen peroxide vaporized will be insufficient, resulting in a high content of hydrogen peroxide in the bottom discharge flow, which in turn has a negative impact on the separation and recovery of hydrogen peroxide and sulfuric acid.

[0035] According to some preferred embodiments of the present invention, in order to further improve the separation efficiency of hydrogen peroxide and sulfuric acid, the pressure of the top 120 of the distillation device 100 can be controlled to be 5 to 10 torr, for example, 5 torr, 6 torr, 7 torr, 8 torr, 9 torr, 10 torr or a range between any two of the foregoing values; in addition or alternatively, the temperature of the top 120 of the distillation device 100 can be controlled to be 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 the range between any two of the foregoing values; in addition or alternatively, the pressure of the bottom 110 of the distillation apparatus 100 can be controlled to be 15 to 20 torr, for example, 15 torr, 16 torr, 17 torr, 18 torr, 19 torr, 20 torr or the range between any two of the foregoing values. According to some other preferred embodiments of the present invention, the pressure difference between the bottom 110 and the top 120 is at least 10 torr, for example, at least 10 torr, at least 11 torr or at least 12 torr. When the pressure difference is controlled within the above range, the size of the distillation device 100 can be moderate while achieving good separation efficiency of hydrogen peroxide and sulfuric acid. If the pressure is less than 10 torr, the pressure difference between the bottom 110 and the top 120 is at least 10 torr, for example, at least 10 torr, at least 11 torr or at least 12 torr. When the pressure difference is controlled within the above range, the size of the distillation device 100 can be moderate while achieving good separation efficiency of hydrogen peroxide and sulfuric acid. If the difference is too small and the same separation efficiency is to be obtained, the size of the distillation apparatus 100 will be too large, which will increase the cost.

[0036] According to some embodiments of the present invention, the length L of the first filler 10 is at least 1.0 m, specifically, for example, at least 1.0 m, at least 1.5 m, at least 2.0 m, at least 2.5 m, at least 3.0 m, at least 3.5 m, at least 4.0 m, at least 4.5 m, at least 5.0 m, at least 5.5 m, at least 6.0 m, at least 6.5 m, at least 7.0 m, at least 7.5 m, at least 8.0 m, at least 8.5 m, at least 9.0 m, at least 9.5 m, at least 10.0 m or at least 10.5 m. Without being limited by a specific theory, if the length L of the first filler is too short, the gas may easily carry more sulfuric acid to the top 120, resulting in a higher sulfuric acid content in the top discharge flow, which is not conducive to the separation of hydrogen peroxide and sulfuric acid.

[0037] 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: 200m 2 / m 3 、225m 2 / m 3 、250m 2 / m 3 、275m 2 / m 3 、300m 2 / m 3 、325m 2 / m 3 、350m 2 / m 3 、375m 2 / m 3 、400m 2 / m 3 、425m 2 / m 3 、450m 2 / m 3 、475m 2 / m 3 , 500m 2 / m 3 、525m 2 / m 3 、550m 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 Or the range between any two of the above values; when the specific surface area of ​​the first filler 10 is controlled within the above range, the separation of hydrogen peroxide and sulfuric acid can be further improved.

[0038] According to some embodiments of the present invention, the type of the first filler 10 may be, for example, bulk filler or structured filler; preferably, it is a structured filler, which is composed of fillers of different geometric shapes and corrugation angles, and the geometric shape or corrugation angle can be adjusted according to actual needs. For example: in order to reduce the pressure drop, a structured filler with a corrugation angle of 30° can be used, or in order to improve the mass transfer performance, a structured filler with a corrugation angle of 45° can be used; in order to simultaneously reduce the pressure drop and improve the separation efficiency, a structured material with a mesh-like geometry can be used.

[0039] 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 is stainless steel, nickel alloy (such as monel alloy), copper metal and its alloy, titanium metal and its alloy, 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), polyvinylidenedifluoride (PVDF), polytetrafluoroethylene (PTFE), perfluoroalkyl vinyl ether copolymer (PFA), fluoroplastic film (ETFE) or a combination thereof; preferably polytetrafluoroethylene, perfluoroalkyl vinyl ether copolymer, fluoroplastic film or a combination thereof.

[0040] According to some preferred embodiments of the present invention, the specific heating device used to control the temperature of the bottom 110 within the above-mentioned specific range may be, for example, Figure 2 The reboiler 50 shown can be used in conjunction with a pump 31 to circulate the aqueous sulfuric acid solution containing hydrogen peroxide through the reboiler 50 so that the aqueous solution can be heated as a whole and evenly, thereby improving the efficiency of gasification.

[0041] According to some embodiments of the present invention, the distillation device 100 may include a cooling device 40. When the bottom discharge stream is discharged from the distillation device 100, the cooling device 40 is used to reduce the temperature of the bottom discharge liquid stream, so that the bottom discharge stream can be accommodated in the first recovery barrel 21, so as to facilitate the storage and collection of the bottom discharge stream. According to other embodiments of the present invention, the distillation device 100 may include a condensing device 41. When the top discharge stream is discharged from the distillation device 100, the condensing device 41 is used to condense the gas in the top discharge stream into liquid, so that the top discharge stream can be accommodated in the second recovery barrel 22, so as to facilitate the storage and collection of the top discharge stream. Preferably, the temperature of the top discharge stream flowing through the condensing device 41 can be controlled to be 1 to 5°C, for example: 1°C, 2°C, 3°C, 4°C, 5°C or the range between any two of the above values; and the types and quantities of the cooling device 40 and the condensing device 41 can be adjusted according to actual needs and are not limited by the present invention. Page 9 of 17 (Instructions)

[0042] According to some embodiments of the present invention, the hydrogen peroxide content of the top effluent stream is calculated relative to the total weight of the top effluent stream, and is 20.0 to 35.0 wt.%, specifically 20.0 wt.%, 20.5 wt.%, 20.6 wt.%, 21.0 wt.%, 22.0 wt.%, 23.0 wt.%, 23.2 wt.%, 24.0 wt.%, 25.0 wt.%, 26.0 wt.%, 27.0 wt.%, 28.0 wt.%, 29.0 wt.%, 30.0 wt.%, 31.0 wt.%, 31.3 wt.%, 32.0 wt.%, 33.0 wt.%, 34.0 wt.%, 35.0 wt.% or a range between any two of the foregoing values; preferably 20.0 to 32.0 wt.%.

[0043] According to some embodiments of the present invention, the hydrogen peroxide content of the bottom discharge stream is calculated relative to the total weight of the bottom discharge stream, and is less than 1.5 wt.%, specifically, for example, less than 1.5 wt.%, less than 1.4 wt.%, less than 1.3 wt.%, less than 1.2 wt.%, less than 1.1 wt.%, less than 1.0 wt.%, less than 0.9 wt.%, less than 0.8 wt.%, less than 0.7 wt.%, less than 0.6 wt.%, less than 0.5 wt.%, less than 0.4 wt.%, less than 0.3 wt.%, less than 0.2 wt.% or less than 0.1 wt.%; preferably, less than 1.0 wt.%. In addition, the bottom discharge stream can be further treated by a method The hydrogen peroxide content of the discharge stream is reduced to below 800 ppm, for example: below 800 ppm, below 600 ppm, below 400 ppm, below 200 ppm, below 150 ppm, below 100 ppm, below 50 ppm; preferably, it is reduced to below 50 ppm, and the method may be, for example: using hydrogen chloride to react with hydrogen peroxide in the bottom discharge stream to produce chlorine and water; or, 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 at high temperature and irradiating the bottom discharge stream with ultraviolet rays to decompose the hydrogen peroxide contained in the bottom discharge stream into oxygen and water, so as to reduce the hydrogen peroxide content in the bottom discharge stream.

[0044] According to some embodiments of the present invention, the sulfuric acid content of the top effluent stream is calculated relative to the total weight of the top effluent stream, and is less than 100 ppm, 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. Page 10 of 17 (Instructions)

[0045] Please read together Figure 1 and Figure 3. The top of the distillation device 200 may further include a reflux device 60, which is arranged corresponding to the top 220 of the distillation device 200. Specifically, in step S120, the reflux device 60 is used to reflux part of the aforementioned top discharge flow into the distillation device 200, and part of the sulfuric acid liquid in the aforementioned top discharge flow contacts the rising sulfuric acid gas and undergoes gas-liquid contact on the surface of the first filler 10, further absorbing the sulfuric acid component in the gas into liquid, and feeding it into the bottom 210 together, so that the refluxed top discharge flow has a lower sulfuric acid content, thereby improving the separation efficiency of hydrogen peroxide and sulfuric acid. According to other embodiments of the present invention, the distillation device 200 may also include a second filler, which is arranged above the first filler 10, which can further improve the performance of mass transfer, wherein the type, length and specific surface area of ​​the second filler 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 device 60 is 0 to 1.0, for example: 0, 0.2, 0.4, 0.6, 0.8, 1.0 or a range between any two of the foregoing values; if the reflux ratio is too high, more hydrogen peroxide may be brought to the bottom of the distillation device 200, which may have a negative impact on the separation of hydrogen peroxide and sulfuric acid. According to some other preferred embodiments of the present invention, the sulfuric acid content of the refluxed top discharge stream is less than 1 ppm. Example

[0046] Hereinafter, the present invention will be further described with detailed description and specific examples. However, it should be understood that these specific examples are only used to help the present invention to be more easily understood and are not used to limit the scope of the present invention.

[0047] The following describes the method for separating hydrogen peroxide and sulfuric acid used in the Examples and Comparative Examples:

[0048] Example 1: A sulfuric acid aqueous solution containing hydrogen peroxide is introduced into a distillation apparatus, and the temperature (feed temperature) is controlled to be 30° C., wherein the sulfuric acid aqueous solution containing hydrogen peroxide comprises 60 wt.% sulfuric acid, 3 wt.% hydrogen peroxide and 37 wt.% water, and the distillation apparatus is as follows: Figure 2 The temperature at the bottom of the distillation apparatus is 70°C, the pressure at the bottom is 20 torr, and the temperature at the top is 43°C. Page 11 of 17 (Instructions) The pressure at the top is 10 torr, thereby generating a top discharge flow and a bottom discharge flow in the distillation device; wherein the distillation device is provided with a first packing, which is a structured packing, and the length of the first packing is 10.0 meters and the specific surface area is 225m 2 / m 3 .

[0049] Example 2: A sulfuric acid aqueous solution containing hydrogen peroxide is introduced into a distillation apparatus, and the temperature (feed temperature) is controlled to be 30° C., wherein the sulfuric acid aqueous solution containing hydrogen peroxide comprises 60 wt.% sulfuric acid, 5 wt.% hydrogen peroxide and 35 wt.% water, and the distillation apparatus is as follows: Figure 2 As shown; the temperature of the bottom of the distillation device is 65°C, the pressure of the bottom is 15 torr, the temperature of the top is 33°C and the pressure of the top is 5 torr, thereby generating a top discharge flow and a bottom discharge flow in the distillation device; wherein the distillation device is provided with a first packing, which is a structured packing, and the length of the first packing is 5.0 meters and the specific surface area is 225m 2 / m 3 .

[0050] Example 3: A sulfuric acid aqueous solution containing hydrogen peroxide is introduced into a distillation apparatus, and the temperature (feed temperature) is controlled to be 30° C., wherein the sulfuric acid aqueous solution containing hydrogen peroxide comprises 60 wt.% sulfuric acid, 3 wt.% hydrogen peroxide and 37 wt.% water, and the distillation apparatus is as follows: Figure 3 As shown, it further includes a reflux device, and its reflux ratio is 0.1; the temperature of the bottom of the distillation device is 71°C, the pressure of the bottom is 20 torr, the temperature of the top is 13°C and the pressure of the top is 10 torr, so as to generate a top discharge flow and a bottom discharge flow in the distillation device; wherein the distillation device is provided with a first packing, which is a structured packing, and the length of the first packing is 10.5 meters and the specific surface area is 207m 2 / m 3 .

[0051] Example 4: A sulfuric acid aqueous solution containing hydrogen peroxide is introduced into a distillation apparatus, and the temperature (feed temperature) is controlled to be 30° C., wherein the sulfuric acid aqueous solution containing hydrogen peroxide comprises 60 wt.% sulfuric acid, 5 wt.% hydrogen peroxide and 35 wt.% water, and the distillation apparatus is as follows: Figure 3 As shown, it further includes a reflux device, and its reflux ratio is 1.0; the temperature at the bottom of the distillation device is 70°C, Page 12 of 17 (Instructions) The bottom pressure is 15 torr, the top temperature is 4°C and the top pressure is 5 torr, thereby generating a top discharge flow and a bottom discharge flow in the distillation device; wherein the distillation device is provided with a first packing, which is a structured packing, and the length of the first packing is 10.0 meters and the specific surface area is 225m 2 / m 3 .

[0052] Example 5: A sulfuric acid aqueous solution containing hydrogen peroxide is introduced into a distillation apparatus, and the temperature (feed temperature) is controlled to be 30° C., wherein the sulfuric acid aqueous solution containing hydrogen peroxide comprises 60 wt.% sulfuric acid, 4 wt.% hydrogen peroxide and 36 wt.% water, and the distillation apparatus is as follows: Figure 2 As shown; the temperature of the bottom of the distillation device is 65°C, the pressure of the bottom is 15 torr, the temperature of the top is 39°C and the pressure of the top is 5 torr, so as to generate a top discharge flow and a bottom discharge flow in the distillation device; wherein the distillation device is provided with a first packing, which is a structured packing, and the length of the first packing is 1.0 meter and the specific surface area is 225m 2 / m 3 .

[0053] Comparative Example 1: It is carried out according to the method disclosed in the prior art (CN205730408U), and the distillation device is not provided with a packing. A sulfuric acid aqueous solution containing hydrogen peroxide is introduced into the distillation device, and the temperature (feed temperature) is controlled to be 30°C, wherein the sulfuric acid aqueous solution containing hydrogen peroxide is composed of 60wt.% sulfuric acid, 5wt.% hydrogen peroxide and 35wt.% water; the temperature of the bottom of the distillation device is 95°C, the pressure of the bottom is 8torr, the temperature of the top is less than 45°C and the pressure of the top is 8torr, thereby generating a top discharge flow and a bottom discharge flow in the distillation device.

[0054] Comparative Example 2: A sulfuric acid aqueous solution containing hydrogen peroxide is introduced into a distillation apparatus, and the temperature (feed temperature) is controlled to be 30° C., wherein the sulfuric acid aqueous solution containing hydrogen peroxide comprises 60 wt.% sulfuric acid, 5 wt.% hydrogen peroxide and 35 wt.% water, and the distillation apparatus is as follows: Figure 3 As shown, it further includes a reflux device, and its reflux ratio is 1.0; the temperature of the bottom of the distillation device is 64°C, the pressure of the bottom is 20 torr, the temperature of the top is 15°C and the pressure of the top is 10 torr, so that on page 13, a total of 17 pages (instructions) The distillation device generates a top discharge flow and a bottom discharge flow; wherein the distillation device is provided with a first packing, which is a structured packing, and the length of the first packing is 10.5 meters and the specific surface area is 225m 2 / m 3 .

[0055] Comparative Example 3: A sulfuric acid aqueous solution containing hydrogen peroxide is introduced into a distillation apparatus, and the temperature (feed temperature) is controlled to be 30° C., wherein the sulfuric acid aqueous solution containing hydrogen peroxide comprises 60 wt.% sulfuric acid, 5 wt.% hydrogen peroxide and 35 wt.% water, and the distillation apparatus is as follows: Figure 3 As shown, it further includes a reflux device, and its reflux ratio is 2.0; the temperature of the bottom of the distillation device is 72°C, the pressure of the bottom is 15 torr, the temperature of the top is 10°C and the pressure of the top is 5 torr, so as to generate a top discharge flow and a bottom discharge flow in the distillation device; wherein the distillation device is provided with a first packing, which is a structured packing, and the length of the first packing is 10.5 meters and the specific surface area is 225m 2 / m 3 .

[0056] Comparative Example 4: A sulfuric acid aqueous solution containing hydrogen peroxide is introduced into a distillation apparatus, and the temperature (feed temperature) is controlled to be 30° C., wherein the sulfuric acid aqueous solution containing hydrogen peroxide comprises 60 wt.% sulfuric acid, 5 wt.% hydrogen peroxide and 35 wt.% water, and the distillation apparatus is as follows: Figure 2 As shown; the temperature of the bottom of the distillation device is 71°C, the pressure of the bottom is 7 torr, the temperature of the top is 32°C and the pressure of the top is 5 torr, thereby generating a top discharge flow and a bottom discharge flow in the distillation device; wherein the distillation device is provided with a first packing, which is a structured packing, and the length of the first packing is 0.5 meters and the specific surface area is 128m 2 / m 3 .

[0057] Here, 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 of Examples 1 to 5 and Comparative Examples 1 to 4 implemented according to the above method are presented in the following Table 1.

[0058] Table 1

[0059] (Continued Table 1) The first filler is a structured filler made of polytetrafluoroethylene (PTFE).

[0060] As can be seen from Table 1, in Examples 1 to 5 in which the length of the first filler is controlled to be at least 1.0 m and the temperature of the bottom of the distillation apparatus is controlled to be 65 to 71° C., it can be observed that the bottom discharge stream has a high sulfuric acid content (e.g., greater than 68.0 wt.%) and an extremely low hydrogen peroxide content (e.g., less than 1.5 wt.%), and the top discharge stream has a high hydrogen peroxide content (e.g., greater than 20.0 wt.%) and an extremely low sulfuric acid content (e.g., less than 10 ppm), that is, a concentrated sulfuric acid aqueous solution and an aqueous hydrogen peroxide solution are obtained at the same time.

[0061] On the contrary, in Comparative Examples 1 to 4, in which the length of the first filler is not simultaneously controlled or the first filler is not provided and the temperature at the bottom of the distillation device is not controlled within the above conditions and ranges, it can be observed that high-purity aqueous sulfuric acid solution and aqueous hydrogen peroxide solution cannot be obtained simultaneously. Specifically, Comparative Example 1 is implemented according to the method disclosed in the prior art (CN205730408U). Since the temperature at the bottom of the distillation device of Comparative Example 1 is too high, hydrogen peroxide is easily decomposed, resulting in a low hydrogen peroxide content in the top discharge flow; in addition, since the first filler is not provided, the rising gas is easy to entrain more sulfuric acid to the top of the distillation device, resulting in a high sulfuric acid content in the top discharge flow. For Comparative Example 2, since the temperature at the bottom of the distillation device is too low, the amount of hydrogen peroxide vaporization is insufficient, resulting in a high hydrogen peroxide content in the bottom discharge flow. For Comparative Example 3, since the temperature at the bottom of the distillation device is too high, hydrogen peroxide is easily decomposed, resulting in a low hydrogen peroxide content in the top discharge flow; in addition, since the reflux ratio exceeds the recommended range, more hydrogen peroxide is brought back to the bottom of the distillation device, resulting in an excessively high hydrogen peroxide content in the bottom discharge flow. For Comparative Example 4, since the length of the first filler is too short, the rising gas is likely to entrain more sulfuric acid to the top of the distillation device, resulting in a high sulfuric acid content in the top discharge flow.

[0062] In view of this, when the length of the first filler is controlled to be at least 1.0 m and the temperature of the bottom of the distillation device is controlled to be 65 to 71° C., concentrated sulfuric acid aqueous solution and aqueous hydrogen peroxide solution can be obtained at the same time, thereby solving the technical problem.

[0063] Herein, all ranges provided are intended to include each specific range within a given range and combinations of subranges between the given ranges. In addition, unless otherwise stated, all ranges provided herein include the endpoints of the ranges. Thus, ranges 1 to 5 specifically include 1, 2, 3, 4, and 5, as well as subranges such as 2 to 5, 3 to 5, 2 to 3, 2 to 4, 1 to 4, etc.

[0064] All publications and patent applications cited in this specification are incorporated herein by reference, and each individual publication or patent application is specifically and individually indicated to be incorporated herein by reference for any and all purposes. In the event of an inconsistency between this document and any publication or patent application incorporated herein by reference, this document controls.

Explanation of symbols

[0065] 10: First filler 20: Waste liquid barrel 21: First recycling bin 22: Second recycling bin 30, 31: Pump 40: Cooling device 41: Condensing device 50: Reboiler 60: Reflux device 100, 200: distillation device 110, 210: bottom 120, 220: top L: length S110, S120: step

Claims

1. A method for separating hydrogen peroxide and sulfuric acid, comprising: introducing an aqueous sulfuric acid solution containing hydrogen peroxide into a distillation apparatus; and Controlling the temperature of the bottom of the distillation apparatus to be 65 to 71° C. so as to generate a top discharge stream and a bottom discharge stream in the distillation apparatus; Wherein, the distillation device is provided with a first filler, and the length of the first filler is at least 1.0 meter.

2. The method according to claim 1, wherein the pressure at the top of the distillation apparatus is 5 to 10 torr.

3. The process according to claim 1, wherein the temperature at the top of the distillation apparatus is 4 to 45°C.

4. The method of claim 1, wherein the specific surface area of ​​the first filler is 200 to 750 m 2 / m 3 . 5 . The method of claim 1 , wherein the first filler is a metal filler, a ceramic filler, a plastic filler, a graphite filler, or a combination thereof. 6 . The method according to claim 5 , wherein the material of the first filler is silicon alloy, tantalum alloy, zirconium alloy or a combination thereof.

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

8. The process of claim 1, wherein the overhead stream has a hydrogen peroxide content of 20.0 to 35.0 wt.%.

9. The process of claim 1, wherein the bottoms stream has a hydrogen peroxide content of less than 1.5 wt.%.

10. The process of claim 9, wherein the bottoms stream has a hydrogen peroxide content of less than 1.0 wt.%.

11. The process of claim 1 wherein the sulfuric acid content of the overhead stream is less than 100 ppm.

12. The process of claim 11, wherein the sulfuric acid content of the overhead stream is less than 10 ppm.

13. The method according to claim 1, wherein the top of the distillation device comprises a condensation device, which is configured to control the temperature of the top discharge stream flowing through the condensation device to be 1 to 5°C.

14. The method according to any one of claims 1 to 13, wherein the distillation apparatus further comprises a reflux apparatus, which is arranged corresponding to the top of the distillation apparatus.

15. The method of claim 14, wherein the reflux ratio of the distillation apparatus is 0 to 1.

0.

16. The process of claim 14, wherein the sulfuric acid content of the overhead stream is less than 1 ppm.

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