Hydrogen peroxide catalytic reactor for ultrapure water production system, ultrapure water production system and method for continuously producing ultrapure water

Abstract

The invention discloses a hydrogen peroxide catalytic reactor for an ultrapure water production system, the ultrapure water production system and a method for continuously producing ultrapure water. A central water distributor in the hydrogen peroxide catalytic reactor is filled with a hydrogen peroxide decomposition catalyst, hollow fiber membranes are arranged around the central water distributor, nitrogen is introduced into the upper ends of the hollow fiber membranes during continuous operation, and the lower ends of the hollow fiber membranes are connected into a vacuum source. The water distributor is divided into three sections by arranging the baffles, the water distributor sequentially passes through the water distributor from bottom to top during operation, hydrogen peroxide carried in pure water to be treated is decomposed into water and oxygen under the action of a catalyst, and dissolved oxygen also enters the hollow fiber membrane to be removed. The problem that the catalytic activity is reduced due to excessive enrichment and oxidation of oxygen on the surface of the hydrogen peroxide decomposition catalyst is effectively avoided, and long-time online operation can be realized without increasing the filling amount of the catalyst.

Description

Technical Field

[0001] The present invention relates to the technical field of ultrapure water production for the semiconductor industry, and in particular to a hydrogen peroxide catalytic reactor for an ultrapure water production system, an ultrapure water production system and a method for continuously producing ultrapure water. Background Art

[0002] The production process of ultra-large-scale integrated circuit systems is still developing rapidly, and leading companies have already entered the process competition below 10nm line width. As one of the key materials in integrated circuit production, the preparation process of ultrapure water also needs to be updated with the development of semiconductors. Ultrapure water will come into direct contact with the product during the cleaning and corrosion processes of the semiconductor production process, and semiconductor products are extremely sensitive to heavy metals, alkali metals, particles and organic pollutants, and oxides.

[0003] According to statistics, TOC pollution accounts for more than 90% of ultrapure water pollution. High TOC content in water will affect the performance of devices. Organic matter will decompose into water, gas and other substances on the surface of silicon wafers, increasing the density of gate oxide defects. In the ultrapure water preparation system, TOC is treated and decomposed by activated carbon, reverse osmosis membrane, and ultraviolet lamp group in order from large to small molecular weight. In particular, the application of ultraviolet lamp group makes the small molecule TOC with low RO interception efficiency have good removal efficiency. The ultraviolet lamp group emits 185nm ultraviolet light when working, and its energy can excite water molecules to produce hydroxyl radicals (OH·). Hydroxyl radicals (OH·) have a high redox potential and can oxidize most organic molecules in water. At the same time, the low-pressure mercury lamp ultraviolet lamp group can emit 245nm range ultraviolet light to control the reproduction of bacteria in water. However, since it is impossible to accurately measure the correspondence between TOC content and UV output, the problem is that when TOC capacity is low, there is an excess of hydroxyl radicals. The excess hydroxyl radicals will generate hydrogen peroxide, which will be carried to the downstream treatment process by ultrapure water. Its strong oxidizing property can decompose polymer fillers such as ion exchange resins, causing local water quality degradation and ion exchange resin escape. Furthermore, if hydrogen peroxide enters the POU end, its oxidizing property will have a serious impact on the process.

[0004] Therefore, how to deal with the remaining hydrogen peroxide has always become an important topic for the precision processing of ultrapure water systems. Platinum / palladium composite nanoparticles have a high catalytic efficiency for the decomposition of hydrogen peroxide (H2O2→H2O+O2). Loading them on a porous framework to prepare a hydrogen peroxide decomposition catalyst is the preferred choice for most technologies. Patent CN110049952A discloses an ultrapure water manufacturing device and an operation method for an ultrapure water manufacturing device, but it does not fully consider the problem of catalyst failure during operation. During operation, the catalyst will fail due to decomposition and oxygen enrichment, and the catalyst cannot be regenerated under this process. Patent CN111183118B has improved and upgraded the catalytic reduction tower, and the catalyst can be regenerated by alternating the introduction of nitrogen, but this method still has the problem of continuous deactivation of the catalyst during operation, and frequent switching regeneration is required. As described in patent CN110049952A, "the excess oxygen generated by decomposition accumulates around the catalyst, causing the catalyst surface to be oxidized and the catalytic activity to weaken. After the catalytic activity weakens, hydrogen peroxide will continue to be output to the downstream process and cause damage in the absence of trace detection." Therefore, how to maintain sufficient catalytic activity during the operation of the catalyst and achieve online switching regeneration has become a technical problem that needs to be solved urgently. Summary of the invention

[0005] In order to solve the problems existing in the prior art, the present invention provides a hydrogen peroxide catalytic reactor for an ultrapure water production system, which can continuously and efficiently decompose hydrogen peroxide generated by excessive excess hydroxyl radicals in ultrapure water, overcome the problem of weakened catalytic activity caused by oxidation of the catalyst surface, and further can be continuously regenerated for online use.

[0006] Another object of the present invention is to provide an ultrapure water production system comprising the above-mentioned hydrogen peroxide catalytic reactor for an ultrapure water production system.

[0007] Another object of the present invention is to provide a method for continuously producing ultrapure water using the above-mentioned hydrogen peroxide catalytic reactor for an ultrapure water production system.

[0008] In order to achieve the above object, the present invention provides the following technical solutions:

[0009] A hydrogen peroxide catalytic reactor for an ultrapure water production system comprises a catalytic function module and a degassing function module, wherein:

[0010] The degassing function module is arranged around the periphery of the catalytic function module to form a jacket structure;

[0011] The catalytic function module comprises a vertical packed tower, a water inlet at the bottom of the packed tower, a water outlet at the top of the packed tower, and a packing, wherein the packing is a hydrogen peroxide decomposition catalyst;

[0012] The degassing function module comprises an air inlet cavity at the top, an air outlet cavity at the bottom, and a hollow fiber membrane group connecting the air inlet cavity and the air outlet cavity;

[0013] The side wall of the vertical packed tower has an opening which is communicated with the cavity of the jacket structure.

[0014] In a specific embodiment, the hydrogen peroxide decomposition catalyst is platinum nanoparticles, platinum / palladium nanoparticles, platinum / palladium / gold nanoparticles loaded with porous framework catalysts; preferably, the nanoparticle particle size is 2 to 50 nm, and the porous framework is selected from any one of alumina, activated carbon, molecular sieves, silica, and organic resins.

[0015] In a specific embodiment, a central water distributor is arranged in the vertical packed tower, and upper and lower water distribution orifice plates are arranged at both ends of the water distributor, and a filter cap is arranged on the orifice plate.

[0016] In a specific embodiment, the central water distributor is divided into three sections A / B / C by a baffle, and the water flow is deflected in sequence through the three sections of fillers and the hollow fiber membrane group under the action of the baffle.

[0017] In a specific embodiment, the openings on the side walls of the vertical packed tower are provided with inlet and outlet water filter caps.

[0018] In a specific embodiment, the outer diameter of the hollow fiber membrane is 250-400 μm, the inner diameter is 120-300 μm, and the porosity is 23-50%, wherein the membrane thickness is generally 100-140 μm, and there is no special restriction; preferably, the surface of the hollow fiber membrane is hydrophobic; more preferably, the hollow fiber membrane is made of polypropylene or polyvinylidene fluoride.

[0019] In a specific embodiment, a non-oxidizing gas, preferably nitrogen or hydrogen, is introduced into the air inlet cavity.

[0020] In a specific embodiment, the gas outlet cavity is connected to a vacuum source and / or an exhaust gas treatment system.

[0021] On the other hand, an ultrapure water production system includes the aforementioned hydrogen peroxide catalytic reactor for an ultrapure water production system.

[0022] In yet another aspect, a method for continuously producing ultrapure water comprises the step of removing oxygen generated by catalytic decomposition of hydrogen peroxide using the aforementioned hydrogen peroxide catalytic reactor for an ultrapure water production system.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] The hydrogen peroxide catalytic reactor for an ultrapure water production system of the present invention can operate efficiently and continuously, and remove oxygen in real time to prevent excessive enrichment on the catalyst surface from causing oxidation deactivation of the catalyst. Therefore, under the same processing volume, the catalyst filling amount of the reactor of the present invention is small, which can effectively save costs; and a high-efficiency deoxygenation mode can be started for a large amount of hydrogen peroxide concentration; further preferably, the catalytic system can also perform online regeneration when the catalyst is inevitably oxidized, thereby improving the utilization efficiency of the catalyst.

[0025] The present invention provides an ultrapure water system with high-efficiency and continuous operation for decomposing hydrogen peroxide catalyst. The system of the present invention can effectively solve the key technical problem that the life of the catalyst is shortened due to oxidation by dissolved oxygen. By utilizing the real-time oxygen removal capability of the hollow fiber membrane, a catalytic reactor in which the catalyst and the hollow fiber membrane coexist is designed and the liquid flow channel is optimized. The system can achieve the effect of decomposing hydrogen peroxide with a low amount of catalyst filling, so that the catalyst can be recycled efficiently and durably, and has important practical application value and industry promotion significance. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The present invention is a schematic structural diagram of a hydrogen peroxide catalytic reactor for an ultrapure water production system.

[0027] Figure 2 The figure is a cross-sectional schematic diagram of A / B / C of a hydrogen peroxide catalytic reactor used in an ultrapure water production system of the present invention.

[0028] Figure 3 This is a curve diagram of the change in the effluent hydrogen peroxide concentration of the experimental example of the present invention.

[0029] Among them, 100 is a catalytic functional module, 101 is a central water distributor, 102 is an upper water distribution orifice plate, 103 is a lower water distribution orifice plate, 104 is a filler, 105 is a water inlet, 106 is a water outlet, 107 is a filter cap, 108 is a baffle, 109 is a baffle, 200 is a degassing functional module, 201 is an air inlet cavity, 202 is an air outlet cavity, 203 is a hollow fiber membrane group, 204 is an air inlet pipeline, and 205 is an air outlet pipeline. DETAILED DESCRIPTION

[0030] In order to better understand the technical solution of the present invention, the following examples will further illustrate the method provided by the present invention, but the present invention is not limited to the listed examples, and should also include any other known changes within the scope of the claims of the present invention.

[0031] A hydrogen peroxide catalytic reactor for an ultrapure water production system has a catalytic function module 100 and a degassing function module 200 integrated inside the catalytic reactor.

[0032] The catalytic function module 100 is similar to a vertical packed tower, with a water inlet 105 arranged at the bottom of the tower, a water outlet 106 arranged at the top of the tower, and a hydrogen peroxide decomposition catalyst filled in the tower as a filler 104. The degassing function module 200 is arranged around the periphery of the catalytic function module 100 to form a jacket structure; the degassing function module 200 includes an air inlet cavity 201 at the top, an air outlet cavity 202 at the bottom, and a hollow fiber membrane silk membrane group 203 connecting the air inlet cavity 201 and the air outlet cavity 202; at the same time, the side wall of the vertical packed tower has an opening, and a filter cap 107 is arranged at the opening, which is connected to the cavity of the jacket structure, and the gas phase and / or water phase can flow through the opening.

[0033] This design of the present invention uses a hydrogen peroxide decomposition catalyst disposed inside the catalytic reactor as a filler to decompose excess hydrogen peroxide into oxygen and water. At the same time, negative pressure is formed inside the hollow fiber membrane to continuously deoxygenate, thereby preventing excessive enrichment of oxygen on the catalyst surface and causing oxidation deactivation of the catalyst.

[0034] Specifically, Figure 1 As shown, the vertical packed tower of the catalytic functional module 100 can also be called a central water distributor 101. An upper water distribution orifice plate 102 is provided on the top of the central water distributor 101, and the upper water distribution orifice plate 102 is connected to the water outlet 106, which is used to evenly distribute the outlet water into the water outlet 106; a lower water distribution orifice plate 103 is provided at the bottom of the central water distributor 101, and the lower water distribution orifice plate 103 is connected to the water inlet 105, which is used to evenly distribute the inlet water into the central water distributor 101. For example, the upper and lower water distribution orifice plates are porous distribution plates similar to nozzles, such as holes with a size of 0.01mm-0.1mm; preferably, a filter cap is provided on the water distribution orifice plate, such as a filter cap with a precision of 0.01mm-0.1mm, to ensure that the loaded catalyst is stable inside the water distributor to prevent the catalyst from escaping.

[0035] The central water distributor 101 is filled with a hydrogen peroxide decomposition catalyst as filler 104, and the filler 104 can be filled in multiple sections, for example Figure 14 sections are filled in, but not limited to this. The specific filling method can adopt the existing technology without special restrictions. In the present invention, the hydrogen peroxide decomposition catalyst is a porous framework catalyst. In a specific scheme, the hydrogen peroxide decomposition catalyst is any one of a platinum nanoparticle-loaded porous framework catalyst, a platinum / palladium nanoparticle-loaded porous framework catalyst, and a platinum / palladium / gold nanoparticle-loaded porous framework catalyst; preferably, the nanoparticle particle size is 2 to 50nm, preferably 2 to 30nm, and more preferably 2 to 10nm; the porous framework is selected from any one of alumina, activated carbon, molecular sieves, silica, and organic resins. The preparation of this precious metal nanoparticle-loaded porous framework catalyst can refer to the existing technology. Specifically, for example, platinum nanoparticles are loaded on an organic anion resin to obtain a platinum nanoparticle-loaded porous framework catalyst. In the present invention, for example, the packing tower space velocity (SV) is adjusted to 1000-2000h -1 .

[0036] In the present invention, there is no particular limitation on the preparation of platinum catalysts, and the prior art can be fully referred to, for example, by combustion method or metal salt reduction method. Preferably, for example, after using a strong alkaline anion exchange resin with a diameter of 0.5 to 0.7 mm to convert it into a chlorine-type resin using hydrochloric acid, palladium chloride, chlorine-type exchange resin and concentrated hydrochloric acid are mixed and stirred for 1.5 to 3 hours, filtered and dried, and reduced with hydrazine hydrate to obtain a supported catalyst loaded with palladium particles with a diameter of 2 to 10 nm. There is a strong interaction between the metal palladium on the surface of the catalytic resin and the quaternary ammonium base in the resin, and the palladium in the catalytic resin prepared by this method has a high dispersion and is not easy to fall off.

[0037] In the present invention, the central water distributor 101 is divided into three sections A / B / C by the baffle 108, and the flow direction of the inlet water, the intermediate water flow, and the outlet water flow is controlled respectively, so that they are evenly distributed in the entire reactor; the side wall of each section is distributed with an inlet and outlet water filter cap 107 to prevent the hydrogen peroxide decomposition catalyst in the central water distributor from escaping; preferably, a baffle 109 is also provided, and under the action of the baffle 108 and the baffle 109, the water flow direction is as follows: Figure 1 As shown by the dotted line, water can completely flow through the hollow fiber membrane module and the three-stage filled catalyst.

[0038] In the present invention, the hollow fiber membrane group 203 of the degassing function module 200 is distributed around the central water distributor 101, the surface of the hollow fiber membrane is highly hydrophobic, the hollow fiber membrane wall has micropores and is hydrophobic, which can allow gas to pass freely while water will be blocked around the hollow fiber membrane, and nitrogen is introduced into the air inlet of the hollow fiber membrane. According to Henry's law, at a certain temperature and equilibrium state, the solubility of a gas in a liquid (expressed as a mole fraction) is proportional to the equilibrium partial pressure of the gas, which is expressed by the formula pB=kx,BxB, where xB is the mole fraction of the volatile solute B (i.e., the dissolved gas) in the solution, pB is the pressure of the gas on the liquid surface at equilibrium, and kx,B is a constant.

[0039] Specifically, the hollow fiber membrane can be made of polypropylene or polyvinylidene fluoride. Preferably, the hollow fiber membrane is made of polyvinylidene fluoride, which can effectively resist oxidation and aging. More preferably, the hollow fiber membrane has an outer diameter of 300 μm, an inner diameter of 200 μm, and a porosity of 25%.

[0040] When the hollow fiber membrane is running, 7N nitrogen is introduced into its air inlet cavity, and the oxygen content is extremely low. The lower air cavity is connected to a vacuum pump. The oxygen generated by the inherent oxygen content in the water and the decomposition of hydrogen peroxide will diffuse into the inner cavity of the membrane fiber and be discharged under the negative pressure of the vacuum pump, thereby achieving the process of removing dissolved oxygen in real time. Specifically, for example, nitrogen is introduced into the air inlet line 204 connected to the air inlet cavity 201, and the air outlet line 205 connected to the air outlet cavity 202 is connected to the vacuum source. While nitrogen is introduced, vacuum is drawn to form a negative oxygen pressure inside the hollow fiber membrane fiber, which is conducive to the oxygen generated around the catalyst to be free and enter the hollow fiber membrane fiber and be taken away, thereby preventing the catalyst from being oxidized. Preferably, the air outlet line 205 can also be connected to the exhaust gas treatment device through a three-way connection to treat the exhaust gas.

[0041] In the present invention, the catalyst-filled central water distributor 6 is divided into three sections, A\B\C. The oxygen generated by the catalytic decomposition of hydrogen peroxide in each section will be removed by the hollow fiber membrane when it flows into the reactor shell. The reactor design space velocity (SV) is 1000-2000h -1 It can not only further improve the utilization efficiency of subsequent catalysts, but also prevent the catalyst surface from being oxidized and deactivated due to dissolved oxygen enrichment.

[0042] Under the dissolved oxygen control of the present invention, if there is continuous oxidation inside the catalyst resulting in unqualified effluent quality, the enhanced catalytic program can be started according to the following method.

[0043] In the enhanced catalytic mode, hydrogen is alternately introduced into the air inlet of the air inlet chamber through a three-way valve, and the lower air chamber is connected to the exhaust gas treatment device. Hydrogen will pass through the hollow fiber membrane and dissolve in the water under the action of the concentration gradient. By adjusting the hydrogen flow and pressure, the hydrogen concentration in the ultrapure water can be adjusted to 0.1-0.3 mg / L.

[0044] According to molecular orbital theory, hydrogen and oxygen cannot react spontaneously at room temperature because the symmetry of their electron cloud orbits does not match. The d orbital of metal palladium will undergo transitions under certain conditions to form d-band holes. At the same time, palladium metal is evenly distributed on the surface of the carrier and will quickly adsorb hydrogen. When the dissolved hydrogen comes into contact with the palladium catalyst, it will be dissociated and appear as adsorbed hydrogen atoms. When the oxygen produced by catalysis is distributed around the catalyst, the two combine to form water under the action of the palladium catalyst.

[0045] Preferably, the hydrogen purge mode and the nitrogen vacuum mode are switched by switching the inlet and outlet three-way valves; for example, 10-60 seconds of hydrogen purge followed by 3-15 minutes of nitrogen vacuum deoxygenation.

[0046] At the same time, according to the description of the hydrogen peroxide removal method and device in CN111183118A, when the catalyst reaches its operating limit and surface oxidation occurs, the regeneration mode can be started, hydrogen can be continuously introduced into the air inlet cavity of the hollow fiber membrane, the air outlet cavity can be connected to the exhaust gas treatment mode, a regeneration pump and a regeneration water tank can be added, and during the continuous circulation of hydrogen-dissolved water, the catalyst surface is restored to a normal state, and the hydrogen peroxide catalyst is regenerated.

[0047] The present invention is further explained below by more specific examples, but does not constitute any limitation.

[0048] Experimental conditions:

[0049] A set of hydrogen peroxide catalytic reactors was designed. The central water distributor had a diameter of 15 cm and was filled with a palladium / platinum composite catalyst. The catalyst was prepared by a solution reaction method (the molar ratio of the precursor was palladium: platinum = 0.8:0.2) with a diameter of 3-10 nm. The palladium / platinum composite nanoparticles were loaded on a sulfonic acid polystyrene anion exchange resin. The anion exchange resin had a diameter of 0.6-0.7 mm and a particle loading of 0.05 W%. The water filtration accuracy of the central water distributor filter cap was 0.15 mm. The central water distributor was divided into three sections, A / B / C, using a partition. Each section of A / B / C had a diameter of 35 cm, a section spacing of 25 cm, and an A / C partition diameter of 25 cm. A hollow fiber membrane group was set inside the catalyst and distributed around the central water distributor. The outer diameter of the hollow fiber membrane was 300 μm, the inner diameter was 200 μm, the porosity was 25%, and it was made of polyvinylidene fluoride.

[0050] The hydrogen peroxide concentration at the ultrapure water inlet is adjusted to 30 ppb through the hydrogen peroxide-water mixing valve, and the inlet flow rate is 20 m 3 / hour. The outlet hydrogen peroxide concentration of the catalytic reactor under the following experimental conditions was detected and recorded respectively, and a curve was made for comparison.

[0051] Comparative Example 1

[0052] During the operation of the catalytic reactor, the air inlet valve of the air inlet chamber is completely closed, the outlet valve of the air outlet chamber is closed, and the reactor is operated continuously for 96 hours to detect the change in the hydrogen peroxide concentration at the outlet.

[0053] Experimental Example 1

[0054] When the catalytic reactor is in operation, the air inlet cavity is connected to 0.6Mpa high-purity nitrogen (99.99999%), and the flow rate is adjusted to 7m 3 / h, the outlet cavity is connected to a vacuum source with a vacuum degree of 50Kpa. The outlet hydrogen peroxide concentration change is detected after continuous operation for 96 hours.

[0055] Experimental Example 2

[0056] Based on the device of Experimental Example 1, the inlet and outlet valves are opened alternately. Working Condition 1: 0.6Mpa high-purity nitrogen (99.99999%) is connected to the inlet cavity, and the flow rate is adjusted to 7m 3 / h, the outlet cavity is connected to a vacuum source, the vacuum degree is 50Kpa, and this operating condition is switched to operating condition 2 after 15 minutes of operation; the inlet cavity is connected to hydrogen (99.99999%) and the operating flow rate is adjusted to 3m 3 / h, the outlet cavity is connected to the tail gas treatment device, and the operating mode is switched to operating mode 1 after 1 minute, and the two modes are operated alternately. The outlet hydrogen peroxide concentration change is detected after continuous operation for 96 hours.

[0057] Regeneration experiments

[0058] After the comparative example 1 was run continuously for 96 h, 3 m of hydrogen was introduced into the air inlet cavity. 3 / h, the gas outlet cavity is connected to the exhaust gas treatment device, the regeneration pump circulates continuously for 20 minutes, and the outlet hydrogen peroxide detection is carried out after flushing for 2 minutes.

[0059] The experimental test results are shown in Table 1 and Figure 3 As shown:

[0060] Table 1 Experimental effluent hydrogen peroxide concentration change table

[0061]

[0062] From the above experimental results, we can know that:

[0063] Comparing Comparative Example 1 with Experimental Example 1, in the absence of oxygen removal, the catalyst surface will be gradually oxidized during operation, resulting in a decrease in catalytic ability. Although the catalytic ability of Experimental Example 1 in which nitrogen and vacuum are introduced for deoxygenation is reduced, it still has a good hydrogen peroxide removal effect, indicating that real-time deoxygenation is beneficial to extending the life of the hydrogen peroxide catalyst.

[0064] From the results of Experimental Example 1 and Experimental Example 2, it can be seen that when hydrogen is mixed, the hydrogen peroxide removal ability is stronger and the catalytic ability decreases more slowly. This is because the action of hydrogen on the catalyst surface causes the forward movement of hydrogen peroxide decomposition and further shortens the oxygen contact amount of the catalyst. This shows that the mixed introduction of hydrogen and nitrogen has a better effect on the efficient and continuous operation of the catalyst.

[0065] From the regeneration effect of the regeneration experiment, it can be seen that when the catalyst is deactivated by oxidation, continuously preparing hydrogen-dissolved water through a hollow fiber membrane for catalyst regeneration has a good effect. The hydrogen-dissolved water removes the oxidation layer on the surface of the deactivated catalyst and re-exposes the catalytic active sites.

[0066] Experimental Example 3

[0067] The same configuration as the catalytic reactor in Experimental Example 1 was used, but the hollow fiber membrane was set to have an outer diameter of 400 μm, an inner diameter of 300 μm, a porosity of 40%, and a polypropylene material.

[0068] When the catalytic reactor is running, the inlet and outlet valves are opened alternately. Working condition 1: 0.6Mpa high-purity nitrogen (99.99999%) is connected to the inlet chamber, and the flow rate is adjusted to 10m 3 / h, the outlet cavity is connected to the vacuum source, the vacuum degree is 50Kpa. Working condition 2: the inlet cavity is connected to hydrogen 5m 3 / h, the air outlet cavity is connected to the exhaust gas treatment device, the operating time of working condition 1 is 5 minutes, the operating time of working condition 2 is 1 minute, and the two modes are operated alternately.

[0069] Use hydrogen peroxide solution to adjust the hydrogen peroxide concentration at the ultrapure water inlet to 30ppb through the mixing valve, and the water inlet flow rate is 20m 3 / hour, set up detection instruments. Detect and record the outlet hydrogen peroxide concentration of the catalytic reactor of this experimental example respectively,

[0070] The experimental results are shown in the following table:

[0071] Table 2 Experimental effluent hydrogen peroxide concentration change table

[0072] Hydrogen peroxide concentration (ppb) Experimental Example 2 Experimental Example 3 Initial concentration 28.9 28.9 2min water concentration 1.2 1.2 24h effluent concentration 1.7 1.5 48h effluent concentration 2.7 2.1 72h effluent concentration 3.3 2.9 96h effluent concentration 4.2 3.6

[0073] From the results of Experimental Example 3 and Experimental Example 2, it can be found that when the hollow fiber membrane is replaced with a polypropylene material with a higher porosity, the nitrogen flow rate and the hydrogen flow rate are increased. During the 96-hour experiment, the hydrogen peroxide concentration control in Experimental Example 3 is better than that in Experimental Example 2. The main reason is that the high nitrogen flow rate leads to an enhanced driving force for the diffusion of oxygen generated by catalysis, and the rapid separation of oxygen reduces the subsequent oxidation failure of the catalyst. At the same time, the high hydrogen flow rate and the porosity of the hollow fiber membrane are also conducive to the rapid reduction and regeneration of the failed catalyst. Therefore, under this working condition, hydrogen peroxide can be effectively removed and the system capacity can be continuously maintained.

[0074] Finally, it should be noted that the described implementation methods are only part of the implementation methods of this application, rather than all of the implementation methods. Based on the implementation methods in this application, all other implementation methods obtained by those skilled in the art without making any creative work are within the scope of protection of this application.

Claims

1. A hydrogen peroxide catalytic reactor for an ultrapure water production system, characterized in that: It includes a catalytic function module and a degassing function module, wherein: The degassing function module is arranged around the periphery of the catalytic function module to form a jacket structure; The catalytic function module comprises a vertical packed tower, a water inlet at the bottom of the packed tower, a water outlet at the top of the packed tower, and a packing, wherein the packing is a hydrogen peroxide decomposition catalyst; The degassing function module comprises an air inlet cavity at the top, an air outlet cavity at the bottom, and a hollow fiber membrane group connecting the air inlet cavity and the air outlet cavity; The side wall of the vertical packed tower has an opening which is communicated with the cavity of the jacket structure.

2. The hydrogen peroxide catalytic reactor for an ultrapure water production system according to claim 1, characterized in that: The hydrogen peroxide decomposition catalyst is any one of platinum nanoparticles, platinum / palladium nanoparticles, and platinum / palladium / gold nanoparticle-loaded porous framework catalysts; preferably, the nanoparticle particle size is 2 to 50 nm, and the porous framework is selected from any one of alumina, activated carbon, molecular sieves, silica, and organic resins.

3. The hydrogen peroxide catalytic reactor for an ultrapure water production system according to claim 1, characterized in that: A central water distributor is arranged in the vertical packed tower, and upper and lower water distribution orifice plates are arranged at both ends of the water distributor, and a filter cap is arranged on the orifice plate.

4. The hydrogen peroxide catalytic reactor for an ultrapure water production system according to claim 3, characterized in that: The central water distributor is divided into three sections A / B / C by a baffle, and the water flow is deflected in sequence through the three sections of fillers and the hollow fiber membrane group under the action of the baffle.

5. The hydrogen peroxide catalytic reactor for an ultrapure water production system according to claim 1, characterized in that: The opening of the side wall of the vertical packed tower is provided with an inlet and outlet water filter cap.

6. The hydrogen peroxide catalytic reactor for an ultrapure water production system according to claim 1, characterized in that: The outer diameter of the hollow fiber membrane is 250-400 μm, the inner diameter is 120-300 μm, and the porosity is 23-50%; preferably, the surface of the hollow fiber membrane is hydrophobic; more preferably, the hollow fiber membrane is made of polypropylene or polytetrafluoroethylene.

7. The hydrogen peroxide catalytic reactor for an ultrapure water production system according to claim 1, characterized in that: The air inlet cavity is introduced with non-oxidizing gas, preferably any one of nitrogen and hydrogen.

8. The hydrogen peroxide catalytic reactor for an ultrapure water production system according to claim 1 or 7, characterized in that: The gas outlet cavity is connected to a vacuum source and / or an exhaust gas treatment system.

9. An ultrapure water production system, characterized in that: The invention comprises a hydrogen peroxide catalytic reactor for an ultrapure water production system as described in any one of claims 1 to 8.

10. A method for continuously producing ultrapure water, characterized in that: The method comprises the step of using the hydrogen peroxide catalytic reactor for an ultrapure water production system as claimed in any one of claims 1 to 8 to remove oxygen generated by catalytic decomposition of hydrogen peroxide.

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