Process for degrading fluorine-containing greenhouse gas in flowing system

Abstract

The invention provides a process for degrading fluorine-containing greenhouse gas in a flowing system, and belongs to the technical field of environmental engineering. The degradation process is carried out in a photoreactor, the photoreactor is filled with a hydrated electron photochemical reagent, an ultraviolet light source is arranged in a matched mode, the ultraviolet light source is started, the hydrated electron photochemical reagent is converted into hydrated electrons in the photoreactor, fluorine-containing greenhouse gas to be degraded is introduced into the hydrated electron photochemical reagent in the photoreactor, and the fluorine-containing greenhouse gas is degraded. The fluorine component in the fluorine-containing greenhouse gas to be degraded is converted into inorganic fluorine ions, and the residual gas is discharged. According to the invention, the efficient degradation of the fluorine-containing greenhouse gas is realized, and the defects of high energy consumption and serious pollution in the traditional technology are overcome. Meanwhile, continuous and efficient operation is achieved through the flow system design, and the method is suitable for industrial application.

Description

Technical Field

[0001] The present application relates to a process for degrading fluorinated greenhouse gases in a flowing system, belonging to the technical field of environmental engineering. Background Art

[0002] Fluorinated greenhouse gases (such as sulfur hexafluoride SF6, hydrochlorofluorocarbons HCFCs, etc.) are widely used in fields such as power equipment, semiconductor manufacturing, and refrigerants due to their excellent chemical stability and electrical properties. However, these gases have extremely high global warming potentials (GWPs). The greenhouse effect of SF6 is 25,200 times that of CO2, and its atmospheric lifetime can reach thousands of years. With the rapid advancement of industrialization, the emissions of these gases have increased significantly, becoming one of the important factors threatening the global climate. Therefore, it is urgent to develop efficient and green technologies for reducing emissions of fluorinated greenhouse gases.

[0003] Traditional treatment technologies for fluorinated greenhouse gases include methods such as physical adsorption, thermal oxidation, catalytic decomposition, and plasma decomposition. Although they have played a certain role in reducing emissions, they generally have problems such as high energy consumption, complex equipment, and difficult by-product treatment, and it is difficult to meet the requirements of modern low-carbon and environmentally friendly industries. In recent years, hydrated electrons have gradually attracted attention due to their short lifetime and strong reducibility. As an active substance, hydrated electrons can efficiently cleave strong polar chemical bonds (such as C-F bonds, S-F bonds) and show great potential in pollutant treatment. However, existing research mainly focuses on using hydrated electrons to remove fluorine-containing pollutants in water, and their application in the treatment of fluorinated greenhouse gases is still blank. Summary of the Invention

[0004] In view of this, the present application provides a process for degrading fluorinated greenhouse gases in a flowing system, which can achieve green degradation of fluorinated greenhouse gases and has important application prospects in chemical production, semiconductor manufacturing, and the power industry.

[0005] Specifically, the present application is achieved through the following solutions:

[0006] A process for degrading fluorinated greenhouse gases in a flowing system, which is carried out in a photoreactor. The photoreactor is filled with a hydrated electron photochemical reagent and is equipped with an ultraviolet light source. When the ultraviolet light source is started, the hydrated electron photochemical reagent is converted into hydrated electrons in the photoreactor. The fluorinated greenhouse gas to be degraded is introduced into the hydrated electron photochemical reagent in the photoreactor, and the fluorine component in the fluorinated greenhouse gas to be degraded is converted into inorganic fluoride ions, and the remaining gas is discharged.

[0007] The above solution uses ultraviolet light to irradiate a hydrated electron photochemical system to generate hydrated electrons. The highly efficiently generated hydrated electrons reduce and cleave fluorinated greenhouse gas molecules. During the reaction process, no inert atmosphere protection or noble metal catalyst is required. The generation and utilization of hydrated electrons are both completed at normal temperature and pressure, achieving the efficient and green treatment of fluorinated greenhouse gases.

[0008] Furthermore, as a preference:

[0009] It further includes a circulation mechanism. The circulation mechanism includes a gas storage unit and a peristaltic pump. The inlet of the gas storage unit is connected to the photoreactor through the first circulation pipe, and the outlet is connected to the peristaltic pump through the second circulation pipe. The peristaltic pump is connected to the photoreactor through the third circulation pipe. In the photoreactor, the bottom of the third circulation pipe extends into the hydrated electron photochemical reagent, while the bottom of the first circulation pipe is above the liquid level of the hydrated electron photochemical reagent. The photoreactor - the first circulation pipe - the gas storage unit - the second circulation pipe - the peristaltic pump - the third circulation pipe form a closed loop for gas. The fluorinated greenhouse gas to be degraded is filled into the gas storage unit and sent into the photoreactor through the second circulation pipe, the peristaltic pump, and the third circulation pipe. After the gas reacts with the hydrated electron photochemical reagent, the component converted into inorganic fluoride ions remains in the photoreactor, and the remaining gas escapes from the hydrated electron photochemical reagent and is sent back into the gas storage unit through the first circulation pipe, and then sent into the photoreactor through the second circulation pipe, the peristaltic pump, and the third circulation pipe until the fluorine content in the gas storage unit reaches the standard, completing the entire circulation treatment. Through this circulation reaction process, the gas degradation efficiency can be optimized, avoiding the defects of high energy consumption and large pollution in traditional treatment methods.

[0010] The hydrated electron photochemical reagent is any one of aqueous sulfite solutions, KI, K4Fe(CN)6, Na4Fe(CN)6, EDTA, EDTA-2Na, indole (Indole) and its derivatives (Indolederivative), etc. Among them, in application, KI, K4Fe(CN)6, Na4Fe(CN)6, EDTA, EDTA-2Na, indole and its derivatives are also in the form of aqueous solutions.

[0011] More preferably, under the irradiation of an ultraviolet light source, the conditions for different hydrated electron photochemical reagents to degrade perfluoro and polyfluoro pollutants in greenhouse gases are as follows:

[0012] The hydrated electron photochemical reagent is an aqueous sulfite solution, such as an aqueous solution of sodium sulfite or potassium sulfite. The molar concentration of the aqueous sulfite solution is 10 - 20 mM, and the pH value is 9 - 12.

[0013] When the hydrated electron photochemical reagent is indole, the molar concentration of the corresponding indole aqueous solution is 0.2 - 0.4 mM, and the pH is 6.5 - 10. The indole aqueous solution is suitable for anaerobic conditions.

[0014] When the hydrated electron photochemical reagent is an indole derivative, the molar concentration of the corresponding indole derivative aqueous solution is 1-2 mM, and the pH is 3-11.

[0015] When ultraviolet light irradiates a hydrated electron photochemical reagent such as a sulfite solution, the hydrated electron photochemical reagent will generate highly reactive hydrated electrons, which can efficiently attack the chemical bonds of fluorinated greenhouse gases (such as C-F bonds and S-F bonds), break the strong polar chemical bonds, and generate inorganic fluoride ions.

[0016] The ultraviolet light wavelength of the ultraviolet light source is 185-254 nm.

[0017] The initial concentration of the fluorine component in the fluorinated greenhouse gas is 10-100%. As the degradation time extends, the concentration of SF6 in the gas storage bag gradually decreases from 100% to 10%.

[0018] The fluorine component in the fluorinated greenhouse gas is sulfur hexafluoride (SF6) and / or hydrochlorofluorocarbon (such as Freon 22).

[0019] The injection rate of the fluorinated greenhouse gas is 1-5 mL / min, and preferably 5 mL / min.

[0020] During the photochemical reaction process, hydrated electron photochemical reagents such as sodium sulfite can generate highly reducing hydrated electrons under ultraviolet light irradiation. The hydrated electrons can efficiently cleave the chemical bonds in the fluorinated gas molecules (such as C-F bonds and S-F bonds), releasing inorganic fluoride ions. The incompletely degraded gas after the reaction is returned to the photochemical reactor through the gas circulation system for further treatment, thereby achieving efficient degradation of the fluorinated greenhouse gas.

[0021] The beneficial effects that this application can achieve include:

[0022] 1) Compared with the traditional high-temperature decomposition technology, this application generates hydrated electrons by a photochemical method to degrade fluorinated gases, avoiding high-temperature and high-pressure conditions, being safe, economical and efficient in operation, and having no requirement for precious metal catalysts, with a significant reduction in cost.

[0023] 2) Compared with physical adsorption or chemical absorption technologies, the photochemical reaction of this application can directly destroy the molecular structure of fluorinated gases, permanently remove the gases by cleaving chemical bonds, without secondary treatment, reducing the operation steps and energy consumption.

[0024] 3) The photochemical method in this application greatly improves the reaction efficiency by recycling and treating the incompletely degraded gas.

[0025] 4) Compared with traditional catalytic decomposition technology, the present application uses hydrated electrons to cleave fluorine-containing chemical bonds without the need for external high-energy excitation conditions. At the same time, the reaction system does not require the addition of oxidants or complex catalysts, reducing the problems of catalyst deactivation and nanoparticle recovery.

[0026] 5) The present application can achieve the efficient recovery of inorganic fluoride ions, avoiding the potential harm caused by the diffusion of by-product inorganic fluoride into the environment in traditional treatment methods, and further improving the environmental safety of the treatment process.

[0027] 6) Compared with traditional gas treatment technologies, the present application adopts a method of photochemical reduction combined with cyclic degradation, which has the characteristics of high treatment efficiency, low energy consumption, and low pollution. It is suitable for the treatment of industrial waste gases containing various fluorinated greenhouse gases (such as sulfur hexafluoride, hydrochlorofluorocarbons, etc.), and has good prospects for popularization and economic benefits.

[0028] The above solution combines a hydrated electron photochemical reagent with a flow reactor to achieve the efficient degradation of fluorinated greenhouse gases in a flow system, overcoming the defects of high energy consumption and high pollution in traditional technologies. At the same time, the design of this flow system realizes continuous and efficient operation, which is suitable for industrial applications. This technology uses an aqueous solution capable of generating hydrated electrons as a raw material, without the use of toxic chemical reagents or noble metal catalysts. The overall technology focuses on low energy consumption and high efficiency, and is particularly suitable for the degradation and conversion of fluorinated greenhouse waste gases, with significant economic and social benefits, and is suitable for the popularization and application of industrial waste gas treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0030] Figure 1 It is a schematic diagram of the degradation process of the present application.

[0031] Reference numerals in the figure: 1. Photoreactor; 2. Ultraviolet light source; 3. Inlet valve; 4. Gas storage unit; 5. Outlet valve; 6. Peristaltic pump; 7. First circulation pipe; 8. Second circulation pipe; 9. Third circulation pipe.

[0032] Figure 2 It is a comparison chart of the experimental results of the degradation of SF6 by the aqueous solution of sodium sulfite, a hydrated electron photochemical reagent.

[0033] (a) Ion chromatogram of the degradation of SF6 by the aqueous solution of sodium sulfite, a hydrated electron photochemical reagent.

[0034] (b) Ion chromatograms corresponding to fluoride ions and sulfate ions at different gradient concentrations, where "0.2 + 2 mg / L" refers to "0.2 mg / L F - + 2 mg / L SO4 2- ",

[0035] (c) Fluoride ion standard curve, (d) SO4 2- standard curve;

[0036] Figure 3 is the nuclear magnetic F spectrum of the degradation of SF6 by the aqueous solution of sodium sulfite, the electrogenerated hydrated electron photochemical reagent, in this application;

[0037] Figure 4 are ion chromatograms of the degradation of SF6 by aqueous solutions of sodium sulfite at different concentrations;

[0038] Figure 5 are ion chromatograms of the degradation of SF6 by different electrogenerated hydrated electron photochemical reagents;

[0039] Figure 6 are ion chromatograms of the degradation of SF6 by aqueous solutions of sodium sulfite at different pH values;

[0040] Figure 7 is the ion chromatogram of the degradation of R22 by the electrogenerated hydrated electron photochemical reagent sodium sulfite;

[0041] Figure 8 is the ion chromatogram of the degradation of the mixed gas of R22 and SF6 by the electrogenerated hydrated electron photochemical reagent sodium sulfite. Detailed implementation manners

[0042] In order to make the technical problems, technical solutions and beneficial effects to be solved by this application clearer and more understandable, the technical solutions in the embodiments of this application will be further described in detail below with reference to the accompanying drawings in the embodiments of this application. It should be understood that the specific embodiments described here are only used to explain this application and are not used to limit the technical solutions of this application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this application without creative efforts belong to the scope of protection of this application.

[0043] Embodiment 1

[0044] This embodiment provides a process for degrading fluorinated greenhouse gases in a flowing system. The embodiments of this application will be described below with reference to the accompanying drawings.

[0045] Refer to Figure 1 , Figure 1 which shows a schematic flow chart of the degradation process in this embodiment. The steps are as follows:

[0046] Step 1: Prepare a 10 mM sodium sulfite aqueous solution (pH about 9), take 40 mL and place it in the photoreactor 1, turn on the ultraviolet light source 2, and irradiate the sodium sulfite aqueous solution in the photoreactor 1 with ultraviolet light (254 nm, 20 W) to excite and generate hydrated electrons with strong reducing properties.

[0047] Step 2: Turn on the peristaltic pump 6 and the outlet valve 5. The SF6 in the gas storage mechanism 4 is accurately injected into the sodium sulfite aqueous solution in the photoreactor 1 through the circulation pipe 2 8 and the outlet valve 5, the peristaltic pump 6, and the circulation pipe 3 9. The injection rate of SF6 is 5 mL / min. SF6 fully contacts and reacts with the hydrated electrons therein to generate inorganic fluoride ions.

[0048] Step 3: During the reaction of step 2, the inlet valve 4 is started, and the undegraded SF6 in the photoreactor 1 is circulated to the gas storage mechanism 4 through the circulation pipe 7, and then pumped into the photoreactor 1 through the peristaltic pump 6 for repeated treatment.

[0049] After several hours of reaction (4 h, 8 h, and 12 h as an example), the fluoride ion concentration in the sodium sulfite aqueous solution was confirmed by nuclear magnetic resonance (NMR) and ion chromatography (IC) analysis. The results were as follows: Figure 2 、 Figure 3 As shown: the fluoride ions (F - ) concentration is 108.88 mg / L, correspondingly, SO4 2- The concentration was 618.69 mg / L; after 8 hours of reaction, the fluoride ion (F - ) concentration is 112.51 mg / L, SO4 2- The concentration was 919.07 mg / L; when the reaction lasted for 12 hours, the fluoride ion (F - ) concentration is 128.57 mg / L, SO4 2- The concentration is 1161.96 mg / L; Figure 3 The f1 value of 121.5 ppm is the chemical shift of fluoride ions, which proves that hydrated electrons can efficiently degrade sulfur hexafluoride, generate inorganic fluoride ions and eliminate greenhouse gases. After 12 hours of reaction, the degradation effect has reached an ideal level.

[0050] Example 2

[0051] The configuration of this embodiment is the same as that of embodiment 1, except that the concentration of the sodium sulfite aqueous solution is replaced from 10 mM to 20 mM, 40 mM and 80 mM respectively.

[0052] Comparison of treatment effects at different concentrations for 12 hours. Figure 4 shown.

[0053] Depend on Figure 4It can be seen that as the concentration of the sodium sulfite solution increases, the concentration of fluoride ions (F - ) generated in the reaction shows a linear increase. This indicates that a sodium sulfite solution with a higher concentration can generate hydrated electrons more effectively, thereby enhancing the degradation effect on sulfur hexafluoride. At a concentration of 80 mM, the generation amount of fluoride ions increases significantly, reaching up to 664.31 mg / L. Correspondingly, the concentration of SO4 2- is 5335.04 mg / L, indicating a high generation efficiency of hydrated electrons in the solution and a significant improvement in the degradation efficiency.

[0054] Example 3

[0055] This example is the same as the setup in Example 1, except that the hydrated electron photochemical reagent is replaced with KI, K4Fe(CN)6, EDTA-2Na, and indole respectively in the sodium sulfite aqueous solution.

[0056] Step 1: Prepare the following photochemical reagent aqueous solutions respectively: KI, K4Fe(CN)6, EDTA-2Na, and indole, with a molar concentration of 10 mM for each.

[0057] Step 2: Take 40 mL of the above solutions and inject them into the photoreactor respectively, and mix them evenly using a magnetic stirrer.

[0058] Step 3: Turn on the ultraviolet light source (wavelength 254 nm, power 20 W) to generate hydrated electrons from the photochemical reagent under light irradiation.

[0059] Step 4: Start the peristaltic pump and inject pure SF6 gas into the photoreactor at a flow rate of 5 mL / min to ensure sufficient contact and reaction between the gas and the solution.

[0060] The treatment effects of each hydrated electron photochemical reagent after 12 h of treatment are as Figure 5 shown: In the flow system of this case, the degradation of fluorine-containing gases (including but not limited to sulfur hexafluoride in this example) can be achieved using the selected hydrated electrons, and inorganic fluoride ions (F - ) are generated, which also proves the universality of the flow system of hydrated electrons in this case for the degradation of fluorine-containing gases.

[0061] Example 4

[0062] This example provides a process for degrading fluorine-containing greenhouse gases in a flow system. Combining Figure 1 , the process steps are as follows:

[0063] Step 1: Prepare a 40mM sodium sulfite aqueous solution (pH approximately 10), take 40mL and place it in a photoreactor 1. By adding 1M HCl and 1M NaOH, the pH of the sodium sulfite aqueous solution is adjusted to four different values: 6, 8, 10, and 12 (pH 6 and 8 are adjusted by 1M HCl, and pH 6 and 8 are adjusted by 1M NaOH). Turn on the ultraviolet light source 2, and the sodium sulfite aqueous solution in the photoreactor 1 is irradiated with ultraviolet light (254nm, 20W), which excites the generation of hydrated electrons with strong reducing properties.

[0064] Step 2: Turn on the peristaltic pump 6 and the outlet valve 5. The SF6 in the gas storage mechanism 4 is accurately injected into the sodium sulfite aqueous solution in the photoreactor 1 through the circulation pipe 2 8 and the outlet valve 5, the peristaltic pump 6, and the circulation pipe 3 9. The injection rate of SF6 is 5 mL / min. SF6 fully contacts and reacts with the hydrated electrons therein to generate inorganic fluoride ions.

[0065] Step 3: During the reaction of step 2, the inlet valve 4 is started, and the undegraded SF6 in the photoreactor 1 is circulated to the gas storage mechanism 4 through the circulation pipe 7, and then pumped into the photoreactor 1 through the peristaltic pump 6 for repeated treatment.

[0066] Comparison of treatment effects at different pH values for 12 hours. Figure 6 As shown in Figure 2, under acidic conditions (pH = 6), the amount of fluoride ions generated is extremely low, about 4.48 mg / L, which is mainly due to the fact that H + It reacts with hydrated electrons, inhibiting their generation. However, as the pH value increases, the amount of fluoride ions generated increases significantly, reaching a maximum concentration of approximately 497.97 mg / L at pH 12, indicating that the efficiency of hydrated electron generation is significantly improved in an alkaline environment. Therefore, adjusting the solution pH to alkaline conditions can significantly improve the degradation efficiency of sulfur hexafluoride.

[0067] When the concentration was changed to 10 mM, 20 mM, and 80 mM, the effect of pH showed the same trend.

[0068] Example 5

[0069] This embodiment provides a process for degrading fluorine-containing greenhouse gases in a flow system, combined with Figure 1 , the process steps are as follows:

[0070] Step 1: Prepare a 40 mM sodium sulfite aqueous solution (pH about 10), take 40 mL and place it in the photoreactor 1, turn on the ultraviolet light source 2, and irradiate the sodium sulfite aqueous solution in the photoreactor 1 with ultraviolet light (254 nm, 20 W) to excite and generate hydrated electrons with strong reducing properties.

[0071] Step 2: Turn on the peristaltic pump 6 and the outlet valve 5. The Freon 22 (CHClF2, R22) in the gas storage mechanism 4 is accurately injected into the aqueous sodium sulfite solution in the photoreactor 1 through the second circulation pipe 8, the outlet valve 5, the peristaltic pump 6, and the third circulation pipe 9. The injection rate of R22 is 5 mL / min. R22 comes into full contact with the solvated electrons therein and reacts to generate inorganic fluoride ions.

[0072] Step 3: During the reaction process of Step 2, start the inlet valve 4. The incompletely degraded R22 in the photoreactor 1 is circulated to the gas storage mechanism 4 through the first circulation pipe 7, and then pumped into the photoreactor 1 by the peristaltic pump 6 for repeated treatment.

[0073] After reacting for several hours (taking 4 h, 8 h, and 12 h as examples), the concentrations of fluoride ions (F - ) and chloride ions (Cl - ) in the aqueous sodium sulfite solution are detected by anion chromatography analysis. The results are as Figure 7 shown: When the reaction lasts for 4 h, the concentration of the generated fluoride ions (F - ) is 6.79 mg / L, and the concentration of Cl - is 442.92 mg / L; when the reaction lasts for 8 h, the concentration of F - is 17.36 mg / L, and the concentration of Cl - is 450.43 mg / L; when the reaction reaches 12 h, the concentration of fluoride ions (F - ) is 18.52 mg / L, and the concentration of Cl - is 452.74 mg / L. It shows that the R22 gas is effectively degraded to generate fluoride ions and chloride ions.

[0074] This experiment shows that the solvated electron degradation system of the present invention is not only applicable to sulfur hexafluoride, but also can effectively degrade other fluorinated greenhouse gases, such as Freon R22. Therefore, the solution of this application provides an effective technical solution for widely treating different types of fluorinated greenhouse gases.

[0075] Example 6

[0076] This example provides a process for degrading fluorinated greenhouse gases in a flowing system. Combining Figure 1 , the process steps are as follows:

[0077] Step 1: Prepare an aqueous sodium sulfite solution with a concentration of 40 mM (pH is about 10). Take 40 mL and place it in the photoreactor 1. Turn on the ultraviolet light source 2. The aqueous sodium sulfite solution in the photoreactor 1 is irradiated with ultraviolet light (254 nm, 20 W) to generate strongly reducing solvated electrons.

[0078] Step 2: Turn on the peristaltic pump 6 and the outlet valve 5. The fluorinated greenhouse gas in the gas storage mechanism 4 (a mixture of SF6 and R22 with a volume ratio of 7:3 and a total gas flow rate of 5 mL / min) is precisely injected into the sodium sulfite aqueous solution in the photoreactor 1 through the second circulation pipe 8, the outlet valve 5, the peristaltic pump 6, and the third circulation pipe 9. The injection rate of the fluorinated greenhouse gas is 5 mL / min. R22, SF6, and the hydrated electrons therein come into full contact and react to generate inorganic fluoride ions.

[0079] Step 3: During the reaction process of Step 2, start the inlet valve 4. The SF6 that has not been completely degraded in the photoreactor 1 is circulated to the gas storage mechanism 4 through the first circulation pipe 7 and then pumped into the photoreactor 1 by the peristaltic pump 6 for repeated treatment.

[0080] After reacting for several hours (taking 4 h, 8 h, and 12 h as examples), the sodium sulfite aqueous solution degrades the mixed gas. The concentrations of fluoride ions (F - ) and chloride ions (Cl - ) in the degradation products are detected by anion chromatography analysis. The results are as Figure 8 shown: When reacting for 4 h, the concentration of the generated fluoride ions (F - ) is 289.72 mg / L, and the concentration of Cl - is 233.85 mg / L; when reacting for 8 h, the concentration of F - is 376.24 mg / L, and the concentration of Cl - is 251.18 mg / L; when reacting for 12 h, the concentration of F - is 589.95 mg / L, and the concentration of Cl - is 286.48 mg / L. This indicates that the fluorine component is effectively degraded to generate fluoride ions and chloride ions.

[0081] In summary of the above embodiments:

[0082] For the greenhouse gas containing SF6 and R22, the degradation process conditions are as follows: Using sodium sulfite aqueous solution, KI, K4Fe(CN)6 aqueous solution, EDTA-2Na aqueous solution, and indole aqueous solution as photoinduced electron photochemical reagents, with a concentration of 0.2 - 80 mM, a pH of 3 - 12, and the reaction duration (i.e., the circulation treatment duration) of 8 - 12 h; the injection rate of the fluorinated greenhouse gas is 1 - 5 min / L.

[0083] The above-described embodiments merely represent several feasible implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the patent of the present invention. The embodiments are not intended to limit the protection scope in the claims of the present invention. For those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can be made. Any equivalent implementation or change made without departing from the present invention should be included in the technology of the present invention.

Claims

1. A process for degrading fluorinated greenhouse gases in a flowing system, characterized in that: The degradation process is carried out in a photoreactor which is filled with a hydrated electron photochemical reagent and equipped with an ultraviolet light source. When the ultraviolet light source is started, the hydrated electron photochemical reagent is converted into hydrated electrons in the photoreactor. The fluorinated greenhouse gas to be degraded is introduced into the hydrated electron photochemical reagent in the photoreactor, and the fluorine component in the fluorinated greenhouse gas to be degraded is converted into inorganic fluoride ions, and the remaining gas is discharged.

2. The process for degrading fluorinated greenhouse gases in a flowing system according to claim 1, characterized in that: It also includes a circulation mechanism. The circulation mechanism includes a gas storage unit and a peristaltic pump. The inlet of the gas storage unit is connected to the photoreactor through the first circulation pipe, and the outlet is connected to the peristaltic pump through the second circulation pipe. The peristaltic pump is connected to the photoreactor through the third circulation pipe. In the photoreactor, the bottom of the third circulation pipe extends into the hydrated electron photochemical reagent, while the bottom of the first circulation pipe is above the liquid level of the hydrated electron photochemical reagent. The photoreactor - the first circulation pipe - the gas storage unit - the second circulation pipe - the peristaltic pump - the third circulation pipe form a closed loop for the gas.

3. The process for degrading fluorinated greenhouse gases in a flowing system according to claim 1, characterized in that: The ultraviolet light wavelength of the ultraviolet light source is 185 - 254 nm.

4. A process for degrading fluorinated greenhouse gases in a flowing system according to claim 1, characterized in that: The initial concentration of the fluorine component in the fluorinated greenhouse gas is 10 - 100%.

5. A process for degrading fluorinated greenhouse gases in a flowing system according to claim 1, characterized in that: The fluorine component in the fluorinated greenhouse gas is sulfur hexafluoride and / or hydrochlorofluorocarbon.

6. A process for degrading fluorinated greenhouse gases in a flowing system according to any one of claims 1 to 5, characterized in that: The hydrated electron photochemical reagent is any one of aqueous sulfite solution, KI, K₄Fe(CN)₆, Na₄Fe(CN)₆, EDTA, EDTA-2Na, indole and its derivatives.

7. A process for degrading fluorinated greenhouse gases in a flowing system according to claim 6, characterized in that: Under the irradiation of the ultraviolet light source, when the hydrated electron photochemical reagent is aqueous sulfite solution, the molar concentration is 10 - 20 mM and the pH value is 9 - 12; when the hydrated electron photochemical reagent is indole, the molar concentration is 0.2 - 0.4 mM and the pH is 6.5 - 10; when the hydrated electron photochemical reagent is indole derivative, the molar concentration is 1 - 2 mM and the pH is 3 - 11; when the hydrated electron photochemical reagent is APCA, the molar concentration is 0.5 - 4.5 mM and the pH is 8 - 10.

8. A process for degrading fluorinated greenhouse gases in a flowing system according to claim 6, characterized in that: The aqueous sulfite solution is an aqueous solution of sodium sulfite or potassium sulfite.

9. A process for degrading fluorinated greenhouse gases in a flowing system according to claim 1, characterized in that: When the fluorine component of the fluorinated greenhouse gas is SF₆ and / or R22, the degradation process conditions are as follows: using any one of aqueous sodium sulfite solution, KI, aqueous K₄Fe(CN)₆ solution, aqueous EDTA-2Na solution, aqueous indole solution as the photosynthetic electron photochemical reagent, the concentration is 0.2 - 80 mM, the pH is 3 - 12, the injection rate of the fluorinated greenhouse gas is 1 - 5 mL / min, and the time for the fluorine component to be degraded to be converted into inorganic fluoride ions is 4 - 12 h.

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