A continuous operation device and method for synergistically treating ozone gas by solid-liquid phase

Abstract

The application discloses a kind of solid-liquid phase collaborative treatment ozone gas continuous operation device and method.The method of the present application first uses ozone decomposition catalyst to carry out preliminary treatment in solid phase to the gas containing high concentration ozone, then it is introduced into liquid phase treatment system, ensure that the final export ozone is ultra-low concentration.And the present application introduces electrolysis process in liquid phase treatment system, by adding different reducing agent with oxidation-reduction cycle characteristics to electrolyte to achieve the double purpose of absorbing ozone and reducing and regenerating solid phase ozone decomposition catalyst, wherein the oxidized reducing agent is regenerated by cathode reduction in electrolytic cell.Finally, the device and method provided by the present application ensure high removal rate of ozone, realize the circulation and regeneration of solid-liquid two phases, and achieve the effect of continuous operation of high concentration ozone gas treatment process.

Description

Technical Field

[0001] This invention belongs to the field of environmental catalysis technology, specifically relating to a continuous operation device and method for solid-liquid phase synergistic treatment of ozone gas. Background Technology

[0002] Currently, ozone has become one of the major air pollutants. High concentrations of ozone can have a significant impact on human health, leading to a range of health problems. Therefore, efficient ozone removal is essential.

[0003] Research on ozone decomposition began as early as the 1970s. Currently, the most commonly used ozone treatment methods include thermal decomposition, activated carbon adsorption, solution absorption, and catalytic decomposition. Catalytic decomposition is currently considered the most ideal and promising method, as it allows for ozone decomposition at relatively low temperatures without the need for wastewater treatment. Among numerous ozone decomposition catalysts, manganese-based materials offer significant advantages such as low cost and high efficiency compared to noble metal and other transition metal oxide catalysts, and are therefore widely studied for use as ozone catalysts. Many teams have researched a series of ozone decomposition catalysts that can treat high concentrations of ozone within a very short contact time while maintaining a certain degree of stability. However, existing catalysts struggle to achieve high stability under high humidity conditions. The catalytic activity of ozone decomposition catalysts decreases significantly in the presence of water vapor or high air humidity. Furthermore, the design of highly moisture-resistant ozone decomposition catalysts can only delay the deactivation time, ensuring ozone removal efficiency for a longer period, but deactivation is still unavoidable. This is a common problem with ozone decomposition catalysts and has always been a bottleneck limiting their large-scale industrial application. Therefore, using high-performance, regenerable ozone decomposition catalysts combined with efficient regeneration methods is key to solving the problem. Currently, most methods used for ozone catalyst regeneration are gas-phase heating regeneration methods. This method can restore the catalyst surface while maintaining the stability of the catalyst structure and composition. However, this method involves high temperatures and an inert gas atmosphere, making it complex and costly to operate. Therefore, developing a highly operable ozone decomposition catalyst regeneration method is essential.

[0004] Furthermore, under high ozone concentrations, catalytic decomposition requires a large amount of catalyst to ensure low ozone concentrations after treatment, significantly increasing application costs. Solution absorption, on the other hand, removes ozone by reacting with a reducing agent in the solution, easily achieving low ozone concentrations at the outlet. Therefore, coupling catalytic decomposition and solution absorption can minimize operating costs while effectively treating high-concentration ozone. However, solution absorption, as a typical one-time low-concentration ozone treatment method, generates a large amount of waste liquid after the absorbent is oxidized and becomes ineffective, causing significant secondary pollution. Therefore, developing a method for recycling and regenerating the absorbent is essential.

[0005] Electrolysis, as an integrated redox process, is characterized by mild conditions and environmental friendliness. By selecting appropriate electrode composition and current conditions, the redox reactions at the anode and cathode can be controlled. Introducing electrolysis into a solution absorption system, and using suitable electrodes and process conditions, allows for the regeneration of the absorbent. Therefore, the coupling of electrolysis and the solution absorption system enables the stable cyclic operation of the solution absorption system. Furthermore, as a reducing system, the solution absorption system can effectively regenerate the ozone decomposition catalyst. This recyclable liquid-phase system achieves both ozone removal and the recycling of the solid-phase ozone decomposition catalyst, achieving continuous solid-liquid phase operation for removing high concentrations of ozone. Summary of the Invention

[0006] To address the aforementioned technical problems, this application provides a continuous operation device and method for solid-liquid phase synergistic treatment of ozone gas, overcoming the problems of: 1) ozone decomposition catalyst activity being inhibited and ozone decomposition rate significantly decreasing under high humidity conditions; 2) ozone decomposition catalyst deactivation and inability to be used for a long time; and 3) the inability to recycle the absorbent in the solution absorption treatment of ozone method.

[0007] The present invention first provides a continuous operation device for solid-liquid phase synergistic treatment of ozone gas, including an ozone gas pipeline, an ozone decomposition catalyst fixed bed, a three-way valve, a spray absorption tower, a fluid pipeline, a centrifugal pump, an electrolytic cell, and a catalyst regeneration tank;

[0008] The ozone decomposition catalyst fixed bed is filled with an ozone decomposition catalyst for catalyzing ozone decomposition. Two ozone decomposition catalyst fixed beds are connected in parallel on the ozone gas pipeline, and a three-way valve is installed at the connection between the inlets of the two ozone decomposition catalyst fixed beds. Detection ports are installed at both the inlet and outlet connections of the ozone decomposition catalyst fixed beds. The spray absorption tower further absorbs ozone gas by spraying an absorbent liquid containing a reducing agent inside. The gas inlet of the spray absorption tower is connected to the outlet connection of the ozone decomposition catalyst fixed bed. The gas outlet of the tower is used to discharge the treated gas; the liquid outlet of the spray absorption tower is connected to the inlet of the electrolytic cell, and the liquid inlet of the spray absorption tower is connected to the outlet of the catalyst regeneration tank; the outlet of the electrolytic cell is connected to the inlet of the catalyst regeneration tank; the electrolytic cell reduces the oxidized reducing agent in the absorption liquid through electrolysis; the catalyst regeneration tank is used to soak the ozone decomposition catalyst, and the deactivated ozone decomposition catalyst is reduced by the absorption liquid in the catalyst regeneration tank; the centrifugal pump is installed on the fluid pipeline, and the centrifugal pump provides power for the circulation of the absorption liquid between the spray absorption tower, the electrolytic cell, and the catalyst regeneration tank.

[0009] As a preferred embodiment of the present invention, detection ports are also provided at the gas outlet and the liquid inlet of the spray absorption tower. The detection port at the gas outlet of the spray absorption tower is used to detect whether the concentration of ozone in the discharged gas meets the discharge standard; the detection port at the liquid inlet of the spray absorption tower is used to detect the concentration of reducing agent in the absorbent liquid introduced into the spray absorption tower, and to adjust the power of the centrifugal pump according to the concentration of reducing agent in the absorbent liquid.

[0010] As a preferred embodiment of the present invention, the ozone decomposition catalyst is a metal oxide catalyst.

[0011] Furthermore, the metal oxide catalyst includes a manganese-based surface-repairable heterojunction ozone decomposition catalyst, and the metal oxide catalyst also includes MnFe 0.25 O x Catalysts, etc., can be selected from any of them in a continuously operating unit.

[0012] The manganese-based surface-repairable heterojunction ozone decomposition catalyst is prepared through the following steps:

[0013] 1.1) Dissolve soluble manganese salt in deionized water to prepare a manganese salt solution with a concentration range of 0.1-1.0 mol / L, and then prepare a mixed alkaline solution of NaOH and Na2CO3; add the manganese salt solution dropwise to an equal volume of deionized water at a rate of 1-3 mL / min, while simultaneously adding the mixed alkaline solution to maintain the pH of the solution at 8-10 to obtain a mixed solution;

[0014] 1.2) The mixed solution obtained in step 1.1) is reacted at 80-100℃ for 24-96 h to form a precipitate. After filtration, the precipitate is washed with deionized water until the pH of the supernatant is 6-7. The washed precipitate is then dried at 40-80℃ for 10-20 h to obtain MnCO3-MnO. x Powdered catalyst;

[0015] 1.3) Combine MnCO3-MnO x The powdered catalyst was dissolved in an aqueous solution with a binder, and the catalyst support was repeatedly immersed in the solution and then dried to obtain a manganese-based surface-repairable heterojunction ozone decomposition catalyst.

[0016] The present invention also provides a method for ozone gas treatment using the above-mentioned continuously operating device, comprising the following steps:

[0017] 1) Start the centrifugal pump installed on the fluid pipeline and simultaneously power the electrolytic cell; the absorbent liquid at the bottom of the spray absorption tower begins to flow under the action of the centrifugal pump. After passing through the electrolytic cell and the catalyst regeneration tank, the absorbent liquid is transported to the top of the spray absorption tower, sprayed at the top of the spray absorption tower and then falls to the bottom of the spray tower, forming a circulation of the absorbent liquid.

[0018] 2) The ozone-containing gas to be treated is introduced into the ozone gas pipeline of the continuously operating device;

[0019] 3) Ozone-containing gas enters one of the ozone decomposition catalyst fixed beds through a three-way valve located at the connection between the inlets of the two ozone decomposition catalyst fixed beds; the ozone decomposition catalyst in the ozone decomposition catalyst fixed bed catalyzes the decomposition of ozone in the ozone-containing gas to obtain the first stage gas.

[0020] 4) The activity of the catalyst is determined by the difference in ozone concentration at the detection ports before and after the catalyst fixed bed, and a threshold for the ozone concentration difference is set. When the difference in ozone concentration at the detection ports before and after the catalyst fixed bed is lower than the set threshold, the ozone decomposition catalyst is deactivated. At this time, the three-way valve is adjusted to introduce ozone-containing gas into another ozone decomposition catalyst fixed bed. The ozone decomposition catalyst in the previous ozone decomposition catalyst fixed bed is taken out and soaked in the catalyst regeneration tank. After soaking, the ozone decomposition catalyst is dried and refilled into the ozone decomposition catalyst fixed bed.

[0021] 5) The first-stage gas output from the fixed bed outlet of the ozone decomposition catalyst enters the spray absorption tower through the gas inlet of the spray absorption tower, and further removes ozone in the spray absorption tower by the absorbent sprayed from the top of the spray absorption tower, and then is discharged from the gas outlet of the spray absorption tower.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1) The present invention provides a method for preparing a highly efficient manganese-based surface-repairable heterojunction ozone decomposition catalyst. The manganese-based surface-repairable heterojunction ozone decomposition catalyst prepared by this method, during the ozone decomposition process, produces MnCO3 and MnO... x The rate-determining steps for the decomposition of ozone are the intermediate (O2) 2- The generation of ) and intermediate (O2) 2- The desorption of MnCO3-MnO x The heterostructure synergistically accelerates the entire ozone decomposition process. In addition, the heterostructure also modulates the electronic state of the active sites and increases the concentration of oxygen vacancies, thereby achieving excellent ozone decomposition activity across the entire humidity range. Prolonged ozone decomposition can lead to a large amount of ozone decomposition intermediates occupying the active sites, resulting in catalyst deactivation. This can be regenerated by using a reducing agent to reduce the catalyst.

[0024] 2) The method for continuous and stable removal of ozone in liquid phase provided by the present invention uses a reducing solution with added reducing agent with oxidation-reduction cycle characteristics as the electrolyte solution of the electrolytic cell. After absorbing ozone, the reducing agent that is oxidized is reduced on the cathode surface, so that the liquid phase has continuous ozone absorption capacity and achieves the purpose of stable operation.

[0025] 3) The method for regenerating ozone catalyst provided by the present invention involves soaking the deactivated ozone decomposition catalyst in a reducing solution containing a reducing agent with oxidation-reduction cycle characteristics, thereby regenerating the deactivated catalyst by reduction and reducing the oxidized reducing agent on the cathode surface, ultimately achieving the purpose of recycling the reducing agent solution and the catalyst. This method is effective for different ozone decomposition catalysts.

[0026] 4) The solid-liquid phase synergistic ozone removal continuous operation method provided by the present invention is designed for working conditions where the ozone amount exceeds the catalyst's processing capacity. A liquid phase absorption system is added after the catalyst to achieve the purpose of completely absorbing ozone. At the same time, the catalyst and liquid phase absorption system in this method can be cyclically and stably operated through the reduction effect of the electrolysis system. Attached Figure Description

[0027] Figure 1 The image shows the XRD pattern of the MnCO3-Mn3O4 renewable manganese-based heterostructure ozone decomposition catalyst prepared in Example 1.

[0028] Figure 2 Scanning electron microscope (SEM) image of the MnCO3-Mn3O4 renewable manganese-based heterostructure ozone decomposition catalyst prepared in Example 1.

[0029] Figure 3Transmission electron microscope (TEM) image of the MnCO3-Mn3O4 renewable manganese-based heterostructure ozone decomposition catalyst prepared in Example 1.

[0030] Figure 4 The diagram shows the catalytic ozone decomposition deactivation and regeneration performance of the MnCO3-Mn3O4 regenerable manganese-based heterostructure ozone decomposition catalyst prepared in Example 1.

[0031] Figure 5 The image shows the deactivation and regeneration of the MnCO3-Mn3O4 regenerable manganese-based heterostructure ozone decomposition catalyst prepared in Example 1.

[0032] Figure 6 The image shows the XRD pattern of the deactivation and regeneration of the MnCO3-Mn3O4 regenerable manganese-based heterostructure ozone decomposition catalyst prepared in Example 1.

[0033] Figure 7 This is a graph showing ozone removal data from the liquid-phase circulating ozone treatment system in Example 2.

[0034] Figure 8 This is a diagram showing the ozone concentration at the outlet during long-term operation of the continuous operation method for solid-liquid phase synergistic ozone removal in Example 4.

[0035] Figure 9 MnFe 0.25 O x Graph showing the deactivation and regeneration performance of the catalyst.

[0036] Figure 10 MnFe 0.25 O x SEM image of catalyst deactivation and regeneration.

[0037] Figure 11 MnFe 0.25 O x XRD pattern of catalyst deactivation and regeneration.

[0038] Figure 12 This is a flowchart of the process of the present invention.

[0039] Figure 13 This is a schematic diagram of the structure of the device of the present invention.

[0040] In the diagram, 1-three-way valve; 2-fixed bed of ozone decomposition catalyst; 3-spray absorption tower; 4-electrolytic cell; 5-catalyst regeneration tank; 6-centrifugal pump. Detailed Implementation

[0041] The present invention will be further described and illustrated below with reference to specific embodiments. The embodiments described are merely examples of the content of this disclosure and do not limit the scope of the invention. The technical features of each embodiment in the present invention can be combined accordingly, provided that there is no mutual conflict.

[0042] The continuous operation device for solid-liquid phase synergistic ozone gas treatment of the present invention, such as Figure 13 As shown, it includes an ozone gas pipeline, a three-way valve 1, an ozone decomposition catalyst fixed bed 2, a spray absorption tower 3, a fluid pipeline, a centrifugal pump 6, an electrolytic cell 4, and a catalyst regeneration tank 5.

[0043] The ozone decomposition catalyst fixed bed 2 is filled with an ozone decomposition catalyst for catalyzing ozone decomposition. Two ozone decomposition catalyst fixed beds 2 are connected in parallel on the ozone gas pipeline, and a three-way valve 1 is provided at the connection of the inlet of the two ozone decomposition catalyst fixed beds 2. Detection ports are provided at the connection of the inlet and the connection of the outlet of the ozone decomposition catalyst fixed bed 2.

[0044] The spray absorption tower 3 further absorbs ozone gas by spraying an absorbent containing a reducing agent inside; the concentration of the reducing agent in the absorbent is 0.1-30 wt%; the reducing agent is one or more of the following: dopamine hydrochloride, sodium hypophosphite, sodium pyrophosphate, disodium hydrogen phosphate, vitamin C, glutamic acid, cysteine, glycine, sodium bisulfite, ferrous sulfate, ferrous chloride, potassium iodide, sodium iodide, sodium thiosulfate, sodium citrate, sodium sulfite, sodium nitrite, potassium nitrite, potassium sulfite, ammonium chloride, sodium borohydride, ammonium sulfate, oxalic acid, salicylic acid, citric acid, boric acid, ammonium oxalate, glucose, ammonium bicarbonate, oleylamine, formamide, methylamine, ethylamine, aniline, dimethylamine, trimethylamine, butylamine, tert-butylamine, isopropylamine, phenethylamine, diethylamine, and ammonium persulfate. An electrolyte is added to the absorbent to enhance its conductivity. The concentration of the electrolyte in the absorbent is 1-30 wt%. The electrolyte is one or more of sodium hydroxide, potassium hydroxide, sulfuric acid, nitric acid, sodium sulfate, potassium sulfate, potassium nitrate, sodium nitrate, and sodium phosphate.

[0045] The gas inlet of the spray absorption tower 3 is connected to the outlet of the ozone decomposition catalyst fixed bed 2, and the gas outlet of the spray absorption tower 3 is used to discharge the treated gas. The liquid outlet of the spray absorption tower 3 is connected to the inlet of the electrolytic cell 4, and the liquid inlet of the spray absorption tower 3 is connected to the outlet of the catalyst regeneration tank 5. The outlet of the electrolytic cell 4 is connected to the inlet of the catalyst regeneration tank 5. The electrolytic cell 4 electrolyzes and reduces the oxidized reducing agent in the absorption liquid, and the catalyst regeneration tank 5 is used to soak the ozone decomposition catalyst. The deactivated ozone decomposition catalyst is reduced by the absorption liquid in the catalyst regeneration tank 5. A centrifugal pump 6 is installed on the fluid pipeline, and the centrifugal pump 6 provides power for the circulation of the absorption liquid between the spray absorption tower 3, the electrolytic cell 4, and the catalyst regeneration tank 5. In a specific embodiment of the present invention, a centrifugal pump 6 is installed on the fluid pipeline between the spray absorption tower 3 and the electrolytic cell 4, the fluid pipeline between the electrolytic cell 4 and the catalyst regeneration tank 5, and the fluid pipeline between the catalyst regeneration tank 5 and the spray absorption tower 3.

[0046] Detection ports are also provided at the gas outlet and liquid inlet of the spray absorption tower 3; the detection port at the gas outlet of the spray absorption tower 3 is used to detect whether the discharged gas meets the discharge standard; the detection port at the liquid inlet of the spray absorption tower 3 is used to detect the concentration of the reducing agent in the absorbent liquid introduced into the spray absorption tower 3, and adjust the power of the centrifugal pump 6 according to the concentration of the reducing agent in the absorbent liquid.

[0047] The ozone decomposition catalyst is a metal oxide catalyst, including manganese-based surface-repairable heterojunction ozone decomposition catalyst.

[0048] In one specific embodiment of the present invention, a method for preparing a manganese-based surface-repairable heterojunction ozone decomposition catalyst is also provided, specifically including the following steps:

[0049] 1.1) Dissolve soluble manganese salt in deionized water to prepare a manganese salt solution with a concentration range of 0.1-1.0 mol / L, and then prepare a mixed alkaline solution of NaOH and Na2CO3; add the manganese salt solution dropwise to an equal volume of deionized water at a rate of 1-3 mL / min, while simultaneously adding the mixed alkaline solution to maintain the pH of the solution at 8-10 to obtain a mixed solution;

[0050] 1.2) The mixed solution obtained in step 1.1) is reacted at 80-100℃ for 24-96 h to form a precipitate. After filtration, the precipitate is washed with deionized water until the pH of the supernatant is 6-7. The washed precipitate is then dried at 40-80℃ for 10-20 h to obtain MnCO3-MnO. x Powdered catalyst;

[0051] 1.3) Combine MnCO3-MnO xThe powdered catalyst was dissolved in an aqueous solution with a binder, and the catalyst support was repeatedly immersed in the solution and then dried to obtain a manganese-based surface-repairable heterojunction ozone decomposition catalyst.

[0052] The present invention also provides a method for ozone gas treatment in a continuously operating device, comprising the following steps:

[0053] 1) Start the centrifugal pump 6 installed on the fluid pipeline and simultaneously power the electrolytic cell 4; the absorbent liquid at the bottom of the spray absorption tower 3 begins to flow under the action of the centrifugal pump 6. After passing through the electrolytic cell 4 and the catalyst regeneration tank 5, the absorbent liquid is transported to the top of the spray absorption tower 3. After being sprayed at the top of the spray absorption tower 3, it falls to the bottom of the spray tower, forming a circulation of the absorbent liquid.

[0054] 2) The ozone-containing gas to be treated is introduced into the ozone gas pipeline of the continuously operating device;

[0055] 3) Ozone-containing gas enters one of the ozone decomposition catalyst fixed beds 2 through a three-way valve 1 located at the connection between the inlets of the two ozone decomposition catalyst fixed beds 2; the ozone decomposition catalyst in the ozone decomposition catalyst fixed bed 2 catalyzes the decomposition of ozone in the ozone-containing gas to obtain the first stage gas.

[0056] 4) The activity of the catalyst is determined by the difference in ozone concentration at the detection ports before and after the catalyst fixed bed, and a threshold for the ozone concentration difference is set. When the difference in ozone concentration at the detection ports before and after the catalyst fixed bed is lower than the set threshold, the ozone decomposition catalyst is deactivated. At this time, the three-way valve 1 is adjusted to introduce ozone-containing gas into another ozone decomposition catalyst fixed bed 2. The ozone decomposition catalyst in the previous ozone decomposition catalyst fixed bed 2 is taken out and soaked in the catalyst regeneration tank 5. After soaking, the ozone decomposition catalyst is dried and refilled into the ozone decomposition catalyst fixed bed 2.

[0057] 5) The first-stage gas output from the outlet of the fixed bed of ozone decomposition catalyst 2 enters the spray absorption tower 3 through the gas inlet of the spray absorption tower 3, and further removes ozone in the spray absorption tower 3 through the absorbent sprayed from the top of the spray absorption tower, and then is discharged from the gas outlet of the spray absorption tower 3.

[0058] Example 1

[0059] like Figure 1 , Figure 2 ,and Figure 3The images shown are XRD patterns, SEM images, and TEM images of the MnCO3-Mn3O4 regenerable manganese-based heterostructure ozone decomposition catalyst prepared by the method of this invention. This invention prepares the MnCO3-Mn3O4 regenerable manganese-based heterostructure ozone decomposition catalyst via a co-precipitation method: First, 0.02 mol of Mn(NO3)2 is mixed with 70 mL of H2O to form a homogeneous solution A. Simultaneously, a mixed solution B containing NaOH and Na2CO3 is prepared, wherein CO3... 2- / OH - The molar ratio was 1 / 2. Solution A was then added dropwise to 70 mL of deionized water, and mixed solution B was added dropwise to the resulting slurry to maintain the pH at approximately 9. The mixture was then allowed to crystallize in a 90°C water bath for 24 hours. The final precipitate was filtered and thoroughly washed with deionized water. 1 g of the catalyst obtained above and 0.2 g of sodium carboxymethyl cellulose were dissolved in 20 mL of water to obtain a viscous solution of the catalyst. Then, 1 g of 200-mesh cordierite was soaked in the viscous solution for 5 minutes, removed, and dried at 100°C. This impregnation process was repeated three times to finally obtain a 15 wt% cordierite-supported MnCO3-Mn3O4 ozone decomposition catalyst.

[0060] Performance evaluation of the MnCO3-Mn3O4 renewable manganese-based heterostructure ozone decomposition catalyst in ozone decomposition reaction: Catalyst activity was tested in a fixed-bed continuous flow reactor. The air flow rate was 0.3 L / min, water vapor was generated by bubbling the gas stream at 25°C, and O3 gas was generated by a vacuum UV lamp. The inlet O3 concentration was 20 ppm, reaching equilibrium with the air. Using 200 mg of MnCO3-Mn3O4 catalyst supported on cordierite, the catalyst was loaded into a temperature-controlled fixed-bed quartz tube reactor with an inner diameter of Φ6 mm. The ozone concentration at the inlet and outlet was monitored and recorded in real-time using an ozone analyzer at 25°C. The test results are listed below. Figure 4 In the middle. By Figure 4 It can be seen that at a relative humidity RH = 95% and a space velocity ratio of 600 L·g -1 ·h -1 Under these conditions, the ozone decomposition rate of the catalyst can still be maintained above 90% after 100 hours of reaction.

[0061] Example 2

[0062] Take 1g of potassium iodide, 1g of sodium sulfite, 1g of sodium sulfate, 5g of potassium hydroxide, 0.2g of dopamine hydrochloride, and 0.2g of sodium hypophosphite and dissolve them in 50mL of deionized water to prepare a reducing solution. Select a nickel mesh as the anode and a carbon cloth loaded with molybdenum sulfide as the cathode.

[0063] Evaluation of the ozone treatment capacity of the liquid-phase circulating ozone absorption system: Ozone gas is generated by an ozone generator at a flow rate of 200 mL / min and an ozone concentration of 500 ppm. The above reducing solution is placed in a 100 mL electrolytic cell at a current of 0.05 A and a current density of 0.3 A / cm³. 2 Under these conditions, ozone gas is introduced into the electrolytic cell via bubbling. An ozone analyzer is used to monitor and record the ozone concentration at the inlet and outlet in real time. Figure 7 It can be seen that after a week of ozone gas treatment, the liquid-phase circulating ozone treatment system can still maintain 100% ozone removal efficiency. At the same time, the Faraday efficiency, which is the proportion of current electrons used to reduce the oxidized and reduced agent, is 96%, and the energy efficiency, which is the ratio of the actual energy consumed to the theoretical energy of reducing the oxidized and reduced agent, is about 65%.

[0064] Example 3

[0065] Dissolve 1g potassium iodide, 1g sodium sulfite, 1g sodium sulfate, 5g potassium hydroxide, 0.2g dopamine hydrochloride, and 0.2g sodium hypophosphite in 50mL of deionized water to prepare a reducing solution. Immerse the deactivated catalyst from Example 1 in this solution for 5 minutes, then remove and air-dry at room temperature to regenerate the catalyst. Figure 4 The results show that the ozone removal capacity of the MnCO3-Mn3O4 catalyst remains almost unchanged after three regenerations. Figure 5 The SEM results show that the catalyst structure did not change significantly before and after deactivation and regeneration. Figure 6 The XRD results show that the catalyst composition did not change significantly before and after deactivation. Table 1 shows the XPS data of the catalyst after deactivation and regeneration. The results indicate that the oxygen vacancies and metal valence states of the catalyst were restored.

[0066] Table 1

[0067]

[0068] Example 4

[0069] Ozone operating conditions: Gas flow rate: 2L / min; Ozone concentration: 1000ppm; Humidity: RH = 60%.

[0070] Process flow as follows Figure 12As shown, 5g of the MnCO3-Mn3O4 catalyst prepared in Example 1 and supported on cordierite was loaded into a temperature-controlled fixed-bed quartz tube reactor with an inner diameter of Φ6mm. The ozone concentration at the inlet and outlet was monitored and recorded in real time using an ozone analyzer at 25℃. 10g of potassium iodide, 10g of sodium sulfite, 10g of sodium sulfate, 50g of potassium hydroxide, 2g of dopamine hydrochloride, and 2g of sodium hypophosphite were dissolved in 500mL of deionized water to prepare a reducing solution. This solution was placed in a 1L electrolytic cell to form a liquid-phase ozone treatment system. This system used a nickel mesh as the anode and a titanium mesh loaded with cobalt oxide as the cathode, operating at a current of 0.5A and a current density of 0.3A / cm². 2 The system operates under controlled conditions. Simultaneously, an ozone analyzer is used to monitor and record the ozone concentration at the outlet of the liquid-phase ozone treatment system in real time. Furthermore, the catalyst deactivation is assessed by measuring the concentrations at the inlet and outlet of the fixed-bed quartz tube reactor. The deactivated catalyst is then immersed in the reducing solution of the liquid-phase ozone treatment system for 5 minutes, subsequently removed, dried at room temperature, and reused. Figure 8 The results show the ozone treatment performance of the solid-liquid phase synergistic ozone removal continuous operation method. It can be seen that after one month of high-concentration, high-volume ozone being introduced, the ozone at the outlet of the liquid phase ozone treatment system can still be maintained at 0 ppm.

[0071] Example 5

[0072] A renewable manganese-based heterostructure ozone decomposition catalyst, MnCO3-Mn2O3, was prepared by co-precipitation: First, 0.02 mol of Mn(NO3)2 and 0.005 mol of KMnO4 were mixed with 70 mL of H2O to form a homogeneous solution. Simultaneously, a mixed solution B containing NaOH and Na2CO3 was prepared, wherein CO3... 2- / OH - The molar ratio was 1 / 2. Solution A was then added dropwise to 70 mL of deionized water, and mixed solution B was added dropwise to the resulting slurry to maintain the pH at approximately 9. The mixture was then allowed to crystallize in a 90°C water bath for 24 hours. The final precipitate was filtered and thoroughly washed with deionized water. 1 g of the catalyst obtained above and 0.2 g of sodium carboxymethyl cellulose were dissolved in 20 mL of water to obtain a viscous solution of the catalyst. Then, 1 g of 200-mesh cordierite was soaked in the viscous solution for 5 minutes, removed, and dried at 100°C. This impregnation process was repeated three times to finally obtain a 15 wt% cordierite-supported MnCO3-Mn2O3 ozone decomposition catalyst.

[0073] Example 6

[0074] Take 1g formamide, 1g potassium nitrite, 1g ferrous chloride, 2mL nitric acid, 0.2g glucose, and 0.2g oxalic acid and dissolve them in 50mL deionized water to prepare a reducing solution. Select a nickel mesh as the anode and a carbon cloth loaded with molybdenum sulfide as the cathode.

[0075] Evaluation of the ozone treatment capacity of the liquid-phase circulating ozone absorption system: Ozone gas is generated by an ozone generator at a flow rate of 200 mL / min and an ozone concentration of 500 ppm. The above reducing solution is placed in a 100 mL electrolytic cell at a current of 0.05 A and a current density of 0.3 A / cm³. 2 Under these conditions, ozone gas is introduced into the electrolytic cell by bubbling, and the ozone concentration at the inlet and outlet is monitored and recorded in real time using an ozone analyzer.

[0076] Example 7

[0077] Take 1g formamide, 1g potassium nitrite, 1g vitamin C, 3g sodium citrate, 0.2g glucose, and 0.2g oxalic acid and dissolve them in 50mL of deionized water to prepare a reducing solution. Soak the deactivated Mn-based heterostructure ozone decomposition catalyst from Example 5 in the solution for 5 minutes, then remove it and air dry it at room temperature to regenerate the catalyst.

[0078] Example 8

[0079] Ozone operation conditions: Gas flow rate: 2 L / min; Ozone concentration: 1000 ppm; Humidity: 60% RH

[0080] Five g of the MnCO3-Mn2O3 catalyst prepared in Example 5 and supported on cordierite was loaded into a temperature-controlled fixed-bed quartz tube reactor with an inner diameter of Φ6 mm. The ozone concentration at the inlet and outlet was monitored and recorded in real time using an ozone analyzer at 25°C. A reducing solution was prepared by dissolving 10 g of formamide, 10 g of potassium nitrite, 10 g of ferrous chloride, 20 mL of nitric acid, 2 g of glucose, and 2 g of oxalic acid in 500 mL of deionized water. This solution was placed in a 1 L electrolytic cell to form a liquid-phase ozone treatment system. The system used a nickel mesh as the anode and a titanium mesh loaded with cobalt oxide as the cathode, operating at a current of 0.5 A and a current density of 0.3 A / cm². 2 The system operates under controlled conditions. Simultaneously, an ozone analyzer is used to monitor and record the ozone concentration at the outlet of the liquid-phase ozone treatment system in real time. Furthermore, the catalyst deactivation is assessed by measuring the concentrations at the inlet and outlet of the fixed-bed quartz tube reactor. The deactivated catalyst is then immersed in the reducing solution of the liquid-phase ozone treatment system for 5 minutes, subsequently removed, dried at room temperature, and reused.

[0081] Example 9

[0082] Dissolve 1g potassium iodide, 1g sodium sulfite, 1g sodium sulfate, 5g potassium hydroxide, 0.2g dopamine hydrochloride, and 0.2g sodium hypophosphite in 50mL of deionized water to prepare a reducing solution. Add MnFe... 0.25 O x The ozone decomposition catalyst was soaked for 5 minutes, then removed and air-dried at room temperature, thus regenerating the catalyst. Figure 9 The results show that after ten regenerations of MnFe 0.25 O x The ozone removal capacity of the catalyst remains almost unchanged. Figure 10 The SEM results show that the catalyst structure did not change significantly before and after deactivation and regeneration. Figure 11 The XRD results show that the catalyst composition did not change significantly before and after deactivation. The XPS results in Table 2 show that the metal valence state and oxygen vacancy concentration of the catalyst were restored after regeneration.

[0083] Table 2

[0084]

[0085] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the present invention. Those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. A continuous operation device for solid-liquid phase synergistic treatment of ozone gas, characterized in that, It includes gas pipelines, three-way valves (1), fixed bed of ozone decomposition catalyst (2), spray absorption tower (3), fluid pipelines, electrolytic cell (4), catalyst regeneration tank (5), and centrifugal pump (6); The fixed bed (2) for ozone decomposition catalyst is filled with an ozone decomposition catalyst for catalyzing ozone decomposition; the ozone decomposition catalyst is a metal oxide catalyst. The metal oxide catalyst includes a manganese-based surface-repairable heterojunction ozone decomposition catalyst, which is prepared through the following steps: 1.1) Dissolve soluble manganese salt in deionized water to prepare a manganese salt solution with a concentration range of 0.1~1.0 mol / L, and then prepare a mixed alkaline solution of NaOH and Na2CO3; The manganese salt solution was added dropwise to an equal volume of deionized water at a rate of 1-3 mL / min, while a mixed alkaline solution was added dropwise to maintain the pH of the solution at 8-10 to obtain a mixed solution. 1.2) The mixed solution obtained in step 1.1) is reacted at 80-100℃ for 24-96 h to form a precipitate. After filtration, the precipitate is washed with deionized water until the pH of the supernatant is 6-7. The washed precipitate is then dried at 40-80℃ for 10-20 h to obtain MnCO3-MnO. x Powdered catalyst; 1.3) Combine MnCO3-MnO x The powdered catalyst was dissolved in an aqueous solution with a binder, and the catalyst support was repeatedly immersed in the solution and then dried to obtain a manganese-based surface-repairable heterojunction ozone decomposition catalyst. Two ozone decomposition catalyst fixed beds (2) are connected in parallel on the gas pipeline, and a three-way valve (1) is provided at the connection of the inlet of the two ozone decomposition catalyst fixed beds (2). Detection ports for detecting ozone concentration are provided on the connection side of the inlet of the ozone decomposition catalyst fixed bed (2) and the connection side of the connection side of the outlet of the ozone decomposition catalyst fixed bed (2). The spray absorption tower (3) further absorbs ozone gas by spraying an absorbent liquid containing a reducing agent inside. The concentration of the reducing agent in the absorbent liquid is 0.1~30 wt%. The reducing agent is one or more of vitamin C, sodium hypophosphite, potassium iodide, sodium iodide, sodium nitrite, potassium nitrite, and sodium borohydride. The gas inlet of the spray absorption tower (3) is connected to the outlet of the fixed bed of ozone decomposition catalyst (2), and the gas outlet of the spray absorption tower (3) is used to discharge the treated gas; the liquid outlet of the spray absorption tower (3) is connected to the inlet of the electrolytic cell (4), and the liquid inlet of the spray absorption tower (3) is connected to the outlet of the catalyst regeneration tank (5); the outlet of the electrolytic cell (4) is connected to the inlet of the catalyst regeneration tank (5); the electrolytic cell (4) reduces the oxidized reducing agent in the absorbent liquid through electrolysis; the catalyst regeneration tank (5) is used to soak the ozone decomposition catalyst, and the deactivated ozone decomposition catalyst is reduced by the absorbent liquid in the catalyst regeneration tank (5); the centrifugal pump (6) is installed on the fluid pipeline, and the centrifugal pump (6) provides power for the absorption liquid to circulate between the spray absorption tower (3), the electrolytic cell (4), and the catalyst regeneration tank.

2. The continuous operation device according to claim 1, characterized in that, The soluble manganese salt mentioned in step 1.1) is Mn 2+ One of the nitrates, sulfates, and chlorides or Mn 2+ A mixture of one of the nitrate, sulfate, and chloride salts with KMnO4; the concentration of NaOH and Na2CO3 in the mixed alkaline solution is in the range of 0.1~0.3 mol / L and the molar ratio of NaOH to Na2CO3 in the mixed alkaline solution is 1~3.

3. The continuous operation device according to claim 1, characterized in that, Step 1.3) MnCO3-MnO x After the powdered catalyst is dissolved in an aqueous solution with a binder, the MnCO3-MnO in the aqueous solution... x The concentration of the powdered catalyst is 5-10 wt%, and the concentration of the binder is 1-5 wt%; the catalyst support is soaked 3-5 times, and the drying temperature is 100-200℃; the binder is one or more of sodium carboxymethyl cellulose and polyethylene glycol; the catalyst support is used for supporting MnCO3-MnO. x Materials for powdered catalysts include cordierite.

4. The continuous operation device according to claim 1, characterized in that, The absorbent contains an electrolyte to enhance its conductivity, and the concentration of the electrolyte in the absorbent is 1-30 wt%. The electrolyte is one or more of sodium hydroxide, potassium hydroxide, sulfuric acid, nitric acid, sodium sulfate, potassium sulfate, potassium nitrate, sodium nitrate, and sodium phosphate.

5. The continuous operation device according to claim 1, characterized in that, The gas outlet and liquid inlet of the spray absorption tower (3) are also equipped with detection ports.

6. A method for treating ozone gas using a continuously operating device as described in claim 1, characterized in that, Includes the following steps: 1) Start the centrifugal pump (6) installed on the fluid pipeline and simultaneously power the electrolytic cell (4); the absorbent at the bottom of the spray absorption tower (3) begins to flow under the action of the centrifugal pump (6). After passing through the electrolytic cell (4) and the catalyst regeneration tank (5), the absorbent is transported to the top of the spray absorption tower (3), sprayed at the top of the spray absorption tower (3) and then falls to the bottom of the spray tower, forming a circulation of the absorbent. 2) The ozone-containing gas to be treated is introduced into the ozone gas pipeline of the continuously operating device; 3) Ozone-containing gas enters one of the ozone decomposition catalyst fixed beds (2) through a three-way valve (1) set at the inlet connection of the two ozone decomposition catalyst fixed beds (2); the ozone decomposition catalyst in the ozone decomposition catalyst fixed bed (2) catalyzes the decomposition of ozone in the ozone-containing gas to obtain the first stage gas; 4) The activity of the catalyst is determined by the difference in ozone concentration at the detection ports before and after the catalyst fixed bed, and a threshold for the difference in ozone concentration is set. When the difference in ozone concentration at the detection ports before and after the catalyst fixed bed is lower than the set threshold, the ozone decomposition catalyst is deactivated. At this time, the three-way valve (1) is adjusted to introduce ozone-containing gas into another ozone decomposition catalyst fixed bed (2). The ozone decomposition catalyst in the previous ozone decomposition catalyst fixed bed (2) is taken out and soaked in the catalyst regeneration tank (5). After soaking, the ozone decomposition catalyst is dried and refilled into the ozone decomposition catalyst fixed bed (2). This ensures the continuous operation of ozone decomposition. 5) The first stage gas output from the outlet of the ozone decomposition catalyst fixed bed (2) enters the spray absorption tower (3) through the gas inlet, and further removes ozone in the spray absorption tower (3) through the absorbent sprayed from the top of the spray absorption tower, and then is discharged from the gas outlet of the spray absorption tower (3).

7. The ozone gas treatment method according to claim 6, characterized in that, After the absorbent at the bottom of the spray absorption tower (3) enters the electrolytic cell (4), the oxidized reducing agent in the absorbent is reduced by the electrolytic cell; the ozone decomposition catalyst is taken out and soaked in the catalyst regeneration tank (5) for 1-30 min.

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