Device and method for recovering sulfuric acid
Through the combined use of infrared and ultraviolet rays, hydrogen peroxide in waste sulfuric acid is decomposed, and problems in the prior art are solved, and problems that harm gas generation are achieved efficient sulfuric acid recovery and purification.
Patent Information
- Application Number
- CN202410559460.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2024-04-16
- Filing Date
- 2024-05-08
- Publication Date
- 2025-03-14
AI Technical Summary
The prior art is difficult to effectively treat hydrogen peroxide in waste sulfuric acid, and commonly used treatment methods will produce hazardous gases such as chlorine, and commercial enzyme treatment is poor and expensive.
Infrared and ultraviolet lamps are used to decompose hydrogen peroxide in the liquid, generate water and oxygen, and discharge oxygen through the pores to achieve liquid treatment and sulfuric acid recovery.
This method can effectively reduce the concentration of hydrogen peroxide in the liquid to ≤50mg/L, avoid the generation of hazardous gases, and do not require additives, which improves the recovery purity of sulfuric acid.
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Figure CN119608078A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a device and method for recovering sulfuric acid, and more particularly to a device and method for decomposing hydrogen peroxide in a liquid. Background Art
[0002] The semiconductor process uses electronic grade sulfuric acid to prepare carboxylic acid solution to clean wafers, and the waste sulfuric acid produced by the cleaning process is the largest source of process waste liquid. The output of waste sulfuric acid in 2021 is 365,000 tons. With the expansion of semiconductor industry production capacity, it is estimated that the output of waste sulfuric acid in 2024 will reach 516,000 tons, which is difficult to remove. The composition of waste sulfuric acid contains >50wt% sulfuric acid and 1-5wt% hydrogen peroxide, which cannot be directly reused due to its strong oxidizing properties. For hydrogen peroxide, the main pollutant in waste sulfuric acid, the current treatment method is to add hydrochloric acid as a catalyst to waste sulfuric acid to degrade the hydrogen peroxide in waste sulfuric acid to ≤50mg / L, but the process will also produce harmful chlorine gas and residual chloride ions in the purified sulfuric acid, which is not the best purification solution. In addition, commercial enzymes can be added to remove hydrogen peroxide from waste sulfuric acid, but the effect is not good and expensive, there are also problems with drug residues and changes in acid quality, so it is difficult to remove and reuse.
[0003] In summary, new methods are urgently needed to treat waste sulfuric acid in order to improve the quality of recovered sulfuric acid. Summary of the invention
[0004] An apparatus for recovering sulfuric acid provided in one embodiment of the present invention comprises a container having a storage space; an inlet located at a first side of the container for introducing a liquid containing sulfuric acid and hydrogen peroxide into the container via a pump; an outlet located at a second side of the container for exporting the treated liquid out of the container, wherein the first side of the container is opposite to the second side; an infrared lamp tube disposed in the storage space of the container for contacting the liquid; an ultraviolet lamp tube disposed in the storage space of the container for contacting the liquid; a bracket located in the storage space of the container and connecting the infrared lamp tube and the ultraviolet lamp tube; and a shielding cover covering the top of the container and having an air hole, wherein the infrared light emitted by the infrared lamp tube and the ultraviolet light emitted by the ultraviolet lamp tube decompose the hydrogen peroxide in the liquid into water and oxygen, the infrared light heats the liquid to 90° C. to 130° C., and the oxygen is discharged from the air hole.
[0005] In some embodiments, the apparatus for recovering sulfuric acid further comprises a three-way valve connected to the outlet for discharging oxygen.
[0006] In some embodiments, the infrared light has a wavelength of 1500 nm to 6500 nm.
[0007] In some embodiments, the ultraviolet light has a wavelength of 230 nm to 275 nm.
[0008] In some embodiments, the energy density of the infrared and ultraviolet rays is 0.1 W / cm 2 Up to 16W / cm 2 .
[0009] In some embodiments, the ratio of the energy density of infrared light to the energy density of ultraviolet light is 4:1 to 20:1.
[0010] In some embodiments, the device for recovering sulfuric acid also includes other infrared lamps and other ultraviolet lamps, the ratio of the total cross-sectional area of the infrared lamps to the cross-sectional area of the container is 1:100 to 5:100, and the ratio of the total cross-sectional area of the ultraviolet lamps to the cross-sectional area of the container is 1:100 to 5:100.
[0011] In some embodiments, the infrared lamps are arranged in a first circle in the cross section of the container, and the ultraviolet lamps are arranged in a second circle in the cross section of the container. The first circle is concentric with the second circle, and the diameter of the first circle is greater than the diameter of the second circle.
[0012] In some embodiments, the flow rate of the liquid introduced from the inlet is 0.5 m / hour to 3 m / hour.
[0013] In some embodiments, the sulfuric acid concentration of the liquid is 50 wt % to 70 wt %.
[0014] In some embodiments, the hydrogen peroxide concentration of the liquid is 10000 mg / L to 60000 mg / L, and the hydrogen peroxide concentration of the treated liquid is ≤50 mg / L.
[0015] In some embodiments, the tube wall of the container has a concave-convex structure.
[0016] A method for recovering sulfuric acid provided by one embodiment of the present invention comprises: providing a liquid into a container, wherein the liquid comprises sulfuric acid and hydrogen peroxide; decomposing the hydrogen peroxide in the liquid into water and oxygen using infrared and ultraviolet rays, and heating the liquid to 90° C. to 130° C. by infrared rays; and collecting the treated liquid.
[0017] In some embodiments, the method further comprises removing oxygen when decomposing hydrogen peroxide in the liquid into water and oxygen.
[0018] In some embodiments, the infrared light has a wavelength of 1500 nm to 6500 nm.
[0019] In some embodiments, the ultraviolet light has a wavelength of 230 nm to 275 nm.
[0020] In some embodiments, the energy density of infrared and ultraviolet rays is 0.1 W / cm 2 Up to 16W / cm 2 .
[0021] In some embodiments, the ratio of the energy density of infrared light to the energy density of ultraviolet light is 4:1 to 20:1.
[0022] In some embodiments, the sulfuric acid concentration of the liquid is 50 wt % to 70 wt %.
[0023] In some embodiments, the hydrogen peroxide concentration of the liquid is 10,000 mg / L to 60,000 mg / L, and the hydrogen peroxide concentration of the treated liquid is ≤50 mg / L. BRIEF DESCRIPTION OF THE DRAWINGS
[0024] Figure 1 FIG. 5 is a perspective view of an apparatus for recovering sulfuric acid in some embodiments.
[0025] Figure 2 This is a schematic diagram of multiple containers connected in series in some embodiments.
[0026] Figure 3 for Figure 1 A cross-sectional view of a bracket, an infrared lamp tube and an ultraviolet lamp tube along section a-a' in a device for recovering sulfuric acid.
[0027] Figure 4 for Figure 1 A cross-sectional view of the arrangement of infrared lamps and ultraviolet lamps in a device for recovering sulfuric acid.
[0028] Wherein, the reference numerals are:
[0029] a-a': cross section
[0030] 100: Installation
[0031] 101: Containers
[0032] 103: Entrance
[0033] 105:Export
[0034] 107: Infrared lamp
[0035] 109:Ultraviolet lamp
[0036] 111,119:Stent
[0037] 113: Three-way valve
[0038] 115: shielding cover
[0039] 117: Stoma DETAILED DESCRIPTION
[0040] An apparatus 100 for recovering sulfuric acid provided in one embodiment of the present invention is as follows: Figure 1As shown. The device 100 includes a container 101 having a containing space. In some embodiments, the material of the container 101 is polytetrafluoroethylene (PTFE) or other suitable materials. PTFE is resistant to acid corrosion and heat, and has a certain degree of reflection effect on infrared and ultraviolet rays, which is beneficial for processing liquids as described below. Figure 1 The container 101 is a cylinder, but is not limited thereto. Those skilled in the art may adopt any reasonable container shape without departing from the scope of the present invention. For example, the cross-section of the container 101 may be square, rectangular, hexagonal, elliptical, or other shapes in addition to a circle, as long as it is convenient to set up and easy to operate. On the other hand, the volume of the container 101 may be 1 liter to 20 liters, but is not limited thereto. If the volume of the container 101 is too small, the amount of liquid that can be processed in a fixed time is insufficient. If the volume of the container 101 is too large, it is inconvenient to assemble and clean.
[0041] The device 100 also includes an inlet 103, which is located on the first side of the container 101 to introduce the liquid containing sulfuric acid and hydrogen peroxide into the container 101 via a pump. The inlet 103 can be connected to a process chamber (not shown) that generates the liquid, such as an etching chamber or a cleaning chamber, via a pipeline. Generally speaking, the liquid generated by the process chamber may contain some solid impurities, which can be removed by a filter before being introduced into the container 101. The material of the pipeline connecting the process chamber and the inlet 103 can be PTFE or polypropylene (PP), depending on the temperature of the liquid generated by the process chamber. If the temperature of the liquid is relatively high (such as greater than 80°C), heat-resistant PTFE must be used as the pipeline. If the temperature of the liquid is relatively low (such as room temperature), PP can be used as the pipeline to reduce costs.
[0042] The device 100 also includes an outlet 105 located at the second side of the container 101 to guide the treated liquid out of the container 101, and the first side of the container is opposite to the second side. The outlet 105 can be connected to a collection tank (not shown), or to an inlet 103 of another device 100. For example, multiple devices 100 can be connected in series, and the outlet 105 of each device 100 is connected to the inlet 103 of the next device 100 via a pipeline, such as Figure 2 As shown. In this way, the amount of liquid processed per unit time can be increased. Connecting multiple small-volume devices 100 in series instead of using a single large-volume device is beneficial for cleaning and maintenance in practical applications. For example, after replacing one of the multiple devices 100 in series with a new device 100, the liquid can be processed and the removed device 100 can be cleaned and maintained at the same time. However, when cleaning and maintaining a single large-volume device, the liquid processing needs to be stopped. Even if a spare single large-volume device is prepared, the cost of disassembling and assembling it is higher than that of the small-volume device 100 in series.
[0043] The device 100 also includes an infrared lamp 107, which is located in the receiving space of the container 101 to contact the liquid. It is worth noting that the infrared lamp 107 is not mounted on the wall of the container 101 to increase the efficiency of the infrared lamp 107. The infrared lamp 107 is made of quartz to avoid the problem of liquid acid corrosion.
[0044] The device 100 also includes an ultraviolet lamp 109, which is located in the accommodating space of the container 101 to contact the liquid. Similarly, the ultraviolet lamp 109 is not mounted on the tube wall of the container 101 to increase the efficiency of the ultraviolet lamp 109. The lamp tube of the ultraviolet lamp 109 is made of quartz to avoid the problem of acid corrosion of the liquid. It is worth noting that the volume of the liquid is not inclined to be higher than the outlet 105, because too high a volume of the liquid will affect the life of the infrared lamp 107 and the ultraviolet lamp 109.
[0045] The device 100 also includes a bracket 111, which is located in the accommodation space of the container 101 and fixes the infrared lamp 107 and the ultraviolet lamp 109. The structure of the bracket 111 is as follows: Figure 3 As shown in the cross-sectional view. Figure 3 for Figure 1 In the device 100 for recovering sulfuric acid, the bracket 111, the infrared lamp tube 107 and the ultraviolet lamp tube 109 are shown in cross-section a-a'. Figure 3 In the embodiment, the support 111 is a cross in a round frame to increase the support, and the infrared lamp 107 and the ultraviolet lamp 109 are respectively located at the cross end points of the support 111. It can be understood that Figure 3 This is only used as an example and is not intended to limit the present invention. In other embodiments, the outer frame of the bracket 111 may be in other shapes such as a square, a hexagon, or other suitable shapes, and the cross may be changed to other patterns such as a cross. In some embodiments, multiple brackets 111 may be arranged at intervals to increase the support, and the intervals between adjacent brackets 111 and the patterns of the brackets 111 may be the same or different. Figure 3 For example, the pattern of the support 111 has a turbulent effect, which helps to evenly mix the liquid flowing from the inlet 103 to the outlet 105. In addition, the wall of the container 101 can be flat as shown in FIG. Figure 1 As shown, it may also have a specific concave-convex structure (not shown) to further enhance the spoiler effect.
[0046] The device 100 also includes a shielding cover 115, which covers the top of the container 101 and has an air hole 117, and the air hole 117 is connected to an exhaust device (not shown). Figure 1 As shown, the lamp holders of the infrared lamp tube 107 and the ultraviolet lamp tube 109 protrude from the shielding cover 115 to be connected to a power source, and the shielding cover 115 may optionally have a bracket 119 to support the ends of the infrared lamp tube 107 and the ultraviolet lamp tube 109 .
[0047] In some embodiments, the infrared light emitted by the infrared lamp tube 107 and the ultraviolet light emitted by the ultraviolet lamp tube 109 decompose the hydrogen peroxide in the liquid into water and oxygen. The infrared light heats the liquid to 90° C. to 130° C., and the oxygen is discharged from the air hole 117. If the temperature of the liquid is too low, the efficiency of decomposing hydrogen peroxide is insufficient. If the temperature of the liquid is too high, a large amount of oxygen may be generated quickly and difficult to control. Infrared light not only has the function of heating the liquid, but also can assist ultraviolet light in decomposing hydrogen peroxide. If the infrared lamp tube 107 is not used and only the ultraviolet lamp tube 109 is used in combination with other heating equipment such as a heating plate to heat the liquid, the effect of decomposing hydrogen peroxide is reduced.
[0048] like Figure 2 The device 100 for recovering sulfuric acid shown may further include a three-way valve 113 connected to the outlet 105 to remove oxygen as appropriate. The three-way valve 113 may be located between the outlet 105 of the container 101 and a collecting tank (not shown), or between the outlet 105 of the container 101 and the inlet 103 of the next container 101. The oxygen generated by decomposing hydrogen peroxide can be discharged through the aforementioned air hole 117 and the three-way valve 113, and will not accumulate in the container 101 and affect the step of treating the liquid. On the other hand, the three-way valve 113 may be connected to the outlet 105 of the container 101 and the inlet 103 (or the collecting tank) of the next container 101 via a pipeline. In addition, the three-way valve 113 may be connected to a gas extraction device (not shown), such as the above-mentioned air hole 117.
[0049] In some embodiments, the wavelength of the infrared light is 1500nm to 6500nm, corresponding to the main absorption peak wavelengths of hydrogen peroxide, such as 2800nm to 2900nm, 3500nm to 3600nm, and 6000nm to 6500nm. If the wavelength of the infrared light is not within the above range, the decomposition effect of hydrogen peroxide cannot be effectively enhanced.
[0050] In some embodiments, the wavelength of the ultraviolet light is 230 nm to 275 nm. If the wavelength of the ultraviolet light is not within the above range, the hydrogen peroxide cannot be effectively decomposed.
[0051] In some embodiments, the energy density of infrared and ultraviolet rays is 0.1 W / cm 2 Up to 16W / cm 2 If the energy density of infrared or ultraviolet rays is too low, hydrogen peroxide cannot be effectively decomposed. If the energy density of infrared or ultraviolet rays is too high, the reaction temperature will be difficult to control, causing sulfuric acid or hydrogen peroxide to boil, increasing the risk of operation.
[0052] In some embodiments, the ratio of the energy density of infrared rays to the energy density of ultraviolet rays is 4:1 to 20:1. If the ratio is too low, the reaction rate cannot be increased, resulting in poor treatment efficiency. If the ratio is too high, the reaction temperature is difficult to control, causing sulfuric acid or hydrogen peroxide to boil, increasing the risk of operation.
[0053] In some embodiments, the device 100 further includes other infrared lamps 107 and other ultraviolet lamps 109, that is, multiple infrared lamps 107 and multiple ultraviolet lamps 109 are used. The ratio of the total cross-sectional area of the infrared lamps 107 to the cross-sectional area of the container 101 is 1:100 to 5:100, and the ratio of the total cross-sectional area of the ultraviolet lamps 109 to the cross-sectional area of the container 101 is 1:100 to 5:100. If the total cross-sectional area of the infrared lamps 107 is too small, the heating time is too long and the expected reaction temperature cannot be reached. If the total cross-sectional area of the infrared lamps 107 is too large, the reaction temperature is difficult to control, causing sulfuric acid or hydrogen peroxide to boil and increase the risk of operation.
[0054] In some embodiments, the infrared lamps 107 are arranged in a first circle in the cross section of the container 101, and the ultraviolet lamps 109 are arranged in a second circle in the cross section of the container 101. The first circle and the second circle are concentric, and the diameter of the first circle is greater than the diameter of the second circle. Figure 4 shown. Figure 4 for Figure 1 A cross-sectional view of the arrangement of infrared lamps and ultraviolet lamps in a sulfuric acid recovery device. It can be understood that Figure 4 Only the cross-section of the infrared lamp 107 and the ultraviolet lamp 109 is shown (the bracket 111 is not shown). In some embodiments, the bracket 111 can be disposed between the infrared lamp 107 and the ultraviolet lamp 109 to be fixed to the container 101. Figure 4 This is only used as an example and is not intended to limit the present invention. A person skilled in the art can arrange the plurality of infrared lamps 107 and ultraviolet lamps 109 in any manner. For example, the infrared lamps 107 and ultraviolet lamps 109 are staggered and arranged in a circle. Regardless of the arrangement of the infrared lamps 107 and ultraviolet lamps 109, the purpose is to achieve the maximum and most uniform infrared and ultraviolet distribution effect with the minimum energy consumption. In this way, the infrared and ultraviolet rays can decompose the hydrogen peroxide in the liquid, and the infrared rays can heat the liquid.
[0055] In some embodiments, the flow rate of the liquid introduced from the inlet is 0.5 m / hour to 3 m / hour. If the flow rate of the liquid introduced is too fast, the effect of decomposing hydrogen peroxide is insufficient. If the flow rate of the liquid introduced is too slow, the uniformity of the liquid is poor and the effect of decomposing hydrogen peroxide is reduced.
[0056] In some embodiments, the sulfuric acid concentration of the liquid is 50 wt % to 70 wt %. The above steps do not substantially affect the sulfuric acid. However, hydrogen peroxide decomposes to produce water and oxygen, so the sulfuric acid concentration in the treated liquid is slightly reduced (diluted by the water produced by the decomposition of hydrogen peroxide).
[0057] In some embodiments, the hydrogen peroxide concentration of the liquid is 10000 mg / L to 60000 mg / L, and the hydrogen peroxide concentration of the treated liquid is ≤50 mg / L. The hydrogen peroxide concentration of the treated liquid may be ≤40 mg / L, ≤30 mg / L, ≤10 mg / L, or even below the instrument measurement limit. In some embodiments, the treated liquid contains a high concentration of sulfuric acid and a very low concentration (or even no) of hydrogen peroxide, so it can be used in lower-level industrial applications without additional purification. In addition, the above method does not add any additives (such as hydrochloric acid) to the liquid, so the treated liquid is essentially composed of water and sulfuric acid (and a small amount of hydrogen peroxide, if present), without other additives.
[0058] In some embodiments, the method for recovering sulfuric acid may include providing a liquid to a container, wherein the liquid includes sulfuric acid and hydrogen peroxide. The container may be the container 101 of the aforementioned device 100 or another container. The hydrogen peroxide in the liquid is then decomposed into water and oxygen using infrared and ultraviolet rays, and the liquid is heated to 90° C. to 130° C. Finally, the treated liquid is collected. As for the wavelength and energy density of the infrared and ultraviolet rays used in this method, as well as the sulfuric acid concentration and hydrogen peroxide concentration of the liquid and the treated liquid, they are similar to those described above and are not repeated here. In summary, the present invention provides a method and device for recovering sulfuric acid, which can decompose hydrogen peroxide in the liquid and effectively recover sulfuric acid without adding an auxiliary agent. Compared with the previous method of adding an auxiliary agent, the method of the present invention can avoid the generation of harmful gases (such as chlorine or NOx) during the reaction process and damage the processing equipment and related pipelines. In addition, the sulfuric acid recovered by the present invention without adding an auxiliary agent has a higher purity and can be directly applied to other industries such as the printed circuit board industry. In addition, the present invention combines ultraviolet rays with infrared rays, which can effectively increase the reaction rate and improve the decomposition efficiency of hydrogen peroxide under the same treatment time compared to the method of using only ultraviolet rays for treatment.
[0059] In order to make the above contents and other purposes, features, and advantages of the present invention more clearly understood, embodiments are given below and described in detail with reference to the accompanying drawings:
[0060] [Example]
[0061] In the following examples, the analysis method of hydrogen peroxide concentration follows the method mentioned by Seller ("Spectrophotometric Determination of Hydrogen Peroxide Using Potassium (IV) Oxalate", Analyst, Oct., 105, 950-954 (1980)). Potassium oxalate titanate acidic solution (3M H2SO4, 0.05M potassium oxalate titanate solution) and different amounts of hydrogen peroxide produce yellow complexes of tetravalent titanium, and the absorbance is measured at 400nm using a spectrophotometer to calibrate the calibration curve. During the analysis, 5mL of potassium oxalate titanate acidic solution, an appropriate amount of sample, and deionized water are taken, and the absorbance (400nm) is measured after uniform mixing, and the hydrogen peroxide concentration of the sample is calculated from the calibration curve.
[0062] Comparative Example 1
[0063] Prepare a mixture of sulfuric acid and hydrogen peroxide (200 mL), which contains 60 wt% sulfuric acid and 50,000 mg / L hydrogen peroxide. Heat the mixture to 90°C on a heating plate, track the concentration of hydrogen peroxide in the mixture and calculate the decomposition reaction rate of hydrogen peroxide (0.0017 min -1 ) and the decomposition efficiency after 1 hour (5%).
[0064] Comparative Example 2
[0065] Prepare a mixture of sulfuric acid and hydrogen peroxide (200 mL), which contains 60 wt% sulfuric acid and 50,000 mg / L hydrogen peroxide. Heat the mixture to 90°C with a heating plate and irradiate with ultraviolet light (254 nm / 0.22 W / cm 2 ) irradiate the mixture. Track the concentration of hydrogen peroxide in the mixture and calculate the decomposition reaction rate of hydrogen peroxide (0.0021min -1 ) and the decomposition efficiency after 1 hour (14%).
[0066] Comparative Example 3
[0067] Prepare a mixture of sulfuric acid and hydrogen peroxide (200 mL), which contains 60 wt% sulfuric acid and 50,000 mg / L hydrogen peroxide. 2 ) irradiates the mixture and heats it to 90°C. Track the concentration of hydrogen peroxide in the mixture and calculate the decomposition reaction rate of hydrogen peroxide (0.0026min -1 ) and the decomposition efficiency after 1 hour (18%).
[0068] Comparative Example 4
[0069] Prepare a mixture of sulfuric acid and hydrogen peroxide (200 mL), which contains 60 wt% sulfuric acid and 45000 mg / L hydrogen peroxide. 2 ) irradiates the mixture and heats it to 105°C. Track the concentration of hydrogen peroxide in the mixture and calculate the decomposition reaction rate of hydrogen peroxide (0.0039min -1 ) and the decomposition efficiency after 1 hour (28%).
[0070] Comparative Example 5
[0071] Prepare a mixture of sulfuric acid and hydrogen peroxide (200 mL), which contains 60 wt% sulfuric acid and 50,000 mg / L hydrogen peroxide. 2 ) irradiates the mixture and heats it to 120°C. Track the concentration of hydrogen peroxide in the mixture and calculate the decomposition reaction rate of hydrogen peroxide (0.0073min -1 ) and the decomposition efficiency after 1 hour (46%).
[0072] Comparative Example 6
[0073] Prepare a mixture of sulfuric acid and hydrogen peroxide (200 mL), which contains 60 wt% sulfuric acid and 55000 mg / L hydrogen peroxide. 2 ) irradiates the mixture and heats it to 130°C. Track the concentration of hydrogen peroxide in the mixture and calculate the decomposition reaction rate of hydrogen peroxide (0.0173 min -1 ) and the decomposition efficiency after 1 hour (68%).
[0074] Example 1
[0075] Prepare a mixture of sulfuric acid and hydrogen peroxide (200 mL), which contains 60 wt% sulfuric acid and 47500 mg / L hydrogen peroxide. 2 ) and ultraviolet light (254nm / 0.22W / cm 2 ) irradiates the mixture and heats it to 130°C. Track the concentration of hydrogen peroxide in the mixture and calculate the decomposition reaction rate of hydrogen peroxide (0.0239 min -1 ) and the decomposition efficiency after 1 hour (~84%). The sulfuric acid concentration of the treated mixed solution was 60wt%, and the hydrogen peroxide concentration was 50mg / L.
[0076] Example 2
[0077] Take the waste liquid (200 mL) produced by the factory, which contains 76 wt% sulfuric acid and 6250 mg / L hydrogen peroxide. 2 ) and ultraviolet light (254nm / 0.22W / cm 2 ) irradiates the mixture and heats it to 130°C. Track the concentration of hydrogen peroxide in the mixture and calculate the decomposition reaction rate of hydrogen peroxide (0.0228 min -1 ) and the decomposition efficiency after 1 hour (~82%). The sulfuric acid concentration of the treated mixed solution was 76wt%, and the hydrogen peroxide concentration was 50mg / L.
[0078] Example 3
[0079] refer to Figure 1 , select a cylindrical container with a diameter of 40 cm and a length of 180 cm, and place four infrared lamps with a diameter of 3 cm (length of 180 cm, radiation wavelength of 1500 nm to 6500 nm, energy density of 9.27 W / cm 2 ) and three 3cm diameter UV lamps (length 180cm, radiation wavelength 253.7nm, energy density 1.02W / cm 2 ) are arranged in a container. The arrangement of infrared lamps and ultraviolet lamps can be referred to Figure 4 . A mixture of sulfuric acid and hydrogen peroxide is prepared, which contains 60wt% sulfuric acid and 47500mg / L hydrogen peroxide. The mixed solution is introduced from the inlet at the bottom of the container at a flow rate of 2.59m / hour. The mixed solution is irradiated with infrared and ultraviolet rays to decompose the hydrogen peroxide, and the infrared heats the mixed solution to 130°C. A vacuum device is connected to the air hole of the shielding cover to discharge the generated oxygen, and then the treated mixed solution is guided to the inlet at the bottom of the container through a three-way valve (for discharging oxygen in the mixed solution), so that the treated mixed solution is circulated back to the container again. Track the concentration of hydrogen peroxide in the mixed solution and calculate the decomposition reaction rate of hydrogen peroxide (0.024min -1 ) and the decomposition efficiency after 1 hour (~85%). The sulfuric acid concentration of the treated mixed solution was 60wt%, and the hydrogen peroxide concentration was 50mg / L.
[0080] Although the present invention has been described above with several embodiments, they are not intended to limit the present invention. Anyone with common knowledge in the technical field may make any changes and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the scope defined by the attached claims.
Claims
1. A device for recovering sulfuric acid, comprising: A container having a containing space; an inlet located at a first side of the container for introducing a liquid containing sulfuric acid and hydrogen peroxide into the container via a pump; an outlet located at the second side of the container to direct a treated liquid out of the container, wherein the first side of the container is opposite to the second side; an infrared lamp, disposed in the accommodating space of the container to contact the liquid; an ultraviolet lamp, disposed in the accommodating space of the container to contact the liquid; A bracket, located in the accommodating space of the container and connecting the infrared lamp tube and the ultraviolet lamp tube; as well as A shielding cover covers the top of the container and has an air hole, and the air hole is connected to an exhaust device, The infrared light emitted by the infrared lamp tube and the ultraviolet light emitted by the ultraviolet lamp tube decompose the hydrogen peroxide in the liquid into water and oxygen. The infrared light heats the liquid to 90° C. to 130° C., and the pore discharges oxygen.
2. The device for recovering sulfuric acid according to claim 1 further comprises a three-way valve connected to the outlet for discharging oxygen.
3. The device for recovering sulfuric acid according to claim 1, wherein the wavelength of the infrared ray is 1500nm to 6500nm.
4. The device for recovering sulfuric acid according to claim 1, wherein the wavelength of the ultraviolet light is 230nm to 275nm.
5. The device for recovering sulfuric acid according to claim 1, wherein the energy density of the infrared ray and the ultraviolet ray is 0.1 W / cm 2 Up to 16W / cm 2 .
6. The device for recovering sulfuric acid according to claim 1, wherein the ratio of the energy density of the infrared ray to the energy density of the ultraviolet ray is 4:1 to 20:
1.
7. The device for recovering sulfuric acid according to claim 1, further comprising other infrared lamps and other ultraviolet lamps, the ratio of the total cross-sectional area of the infrared lamps to the cross-sectional area of the container being 1:100 to 5:100, and the ratio of the total cross-sectional area of the ultraviolet lamps to the cross-sectional area of the container being 1:100 to 5:
100.
8. The device for recovering sulfuric acid according to claim 7, wherein the infrared lamps are arranged to form a first circle in the cross section of the container, the ultraviolet lamps are arranged to form a second circle in the cross section of the container, the first circle is concentric with the second circle, and the diameter of the first circle is greater than the diameter of the second circle.
9. The device for recovering sulfuric acid according to claim 1, wherein the flow rate of the liquid introduced from the inlet is 0.5 m / hour to 3 m / hour.
10. The device for recovering sulfuric acid according to claim 1, wherein the sulfuric acid concentration of the liquid is 50wt% to 70wt%.
11. The device for recovering sulfuric acid according to claim 1, wherein the hydrogen peroxide concentration of the liquid is 10000 mg / L to 60000 mg / L, and the hydrogen peroxide concentration of the treated liquid is ≤50 mg / L.
12. The device for recovering sulfuric acid according to claim 1, wherein the tube wall of the container has a concave-convex structure.
13. A method for recovering sulfuric acid, comprising: Providing a liquid into a container, wherein the liquid includes sulfuric acid and hydrogen peroxide; Decomposing hydrogen peroxide in the liquid into water and oxygen by infrared and ultraviolet rays, and heating the liquid to 90° C. to 130° C. by the infrared rays; and Collect the treated liquid.
14. The method for recovering sulfuric acid according to claim 13, further comprising removing oxygen when decomposing hydrogen peroxide in the liquid into water and oxygen.
15. The method for recovering sulfuric acid according to claim 13, wherein the wavelength of the infrared ray is 1500 nm to 6500 nm.
16. The method for recovering sulfuric acid according to claim 13, wherein the wavelength of the ultraviolet light is 230 nm to 275 nm.
17. The method for recovering sulfuric acid according to claim 13, wherein the energy density of the infrared ray and the ultraviolet ray is 0.1 W / cm 2 Up to 16W / cm 2 .
18. The method for recovering sulfuric acid according to claim 13, wherein the ratio of the energy density of the infrared ray to the energy density of the ultraviolet ray is 4:1 to 20:
1.
19. The method for recovering sulfuric acid according to claim 13, wherein the sulfuric acid concentration of the liquid is 50 wt% to 70 wt%.
20. The method for recovering sulfuric acid according to claim 13, wherein the hydrogen peroxide concentration of the liquid is 10000 mg / L to 60000 mg / L, and the hydrogen peroxide concentration of the treated liquid is ≤50 mg / L.