PFOS-containing fire-fighting foam decomposition device and method

Abstract

The present application relates to the technical field of PFOS-containing fire-fighting foam decomposition, and particularly relates to a PFOS-containing fire-fighting foam decomposition device and method, which comprises a magnetization device, a heating furnace and a wet absorption device. The magnetization device is used to reduce the molecular force of perfluorooctane sulfonamide molecules in the PFOS-containing fire-fighting foam through the magnetic field thereof. The heating furnace is connected to the magnetization device and used to perform thermal decomposition treatment on the PFOS-containing fire-fighting foam treated by the magnetization device. The wet absorption device is connected to the exhaust outlet of the heating furnace and used to absorb the perfluorocarbon gas generated by the thermal decomposition of the PFOS-containing fire-fighting foam. The present application can improve the degradation rate and degradation efficiency of PFOS in the PFOS-containing fire-fighting foam, and can also reduce the degradation time and energy consumption.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of PFOS-containing fire-fighting foam decomposition, in particular to a PFOS-containing fire-fighting foam decomposition treatment device and method. BACKGROUND

[0002] Perfluorooctane sulfonamide compounds (PFOS) are a kind of artificially synthesized organic compounds, due to their unique physicochemical properties such as hydrophobicity, oleophobicity and high stability, they are widely used in fire-fighting foam and other fields, and their production and use have been more than 50 years. However, due to the detection of such compounds in water, soil, atmosphere, organisms, food and human body samples, their environmental hazards and human exposure risks have been paid more and more attention. In 2009, PFOS and its main precursors were listed in Annex B of the Stockholm Convention, marking that PFOS has become a typical persistent organic pollutant. Water film foam extinguishing agent containing PFOS is also prohibited from being used. Due to the large amount of production before, there is surplus product that has not been used and is prohibited from being used, and this part of water film foam extinguishing agent needs to be treated, because it contains PFOS which is difficult to decompose, so the treatment thereof becomes the research focus.

[0003] At present, there is no effective means to decompose PFOS and other compounds in the world, and the only possible method to decompose PFOS is incineration. This method has the defects of low PFOS degradation efficiency, high energy consumption and long degradation time. SUMMARY

[0004] The technical problem to be solved by the present application is to overcome the defects of the prior art and provide a PFOS-containing fire-fighting foam decomposition treatment device which can improve the degradation rate and degradation efficiency of PFOS in PFOS-containing fire-fighting foam, and also reduce the degradation time and energy consumption.

[0005] In order to solve the above technical problems, the technical scheme of the present application is as follows: a PFOS-containing fire-fighting foam decomposition treatment device, comprising:

[0006] A magnetization device for reducing the molecular force of perfluorooctane sulfonamide molecules in PFOS-containing fire-fighting foam through the magnetic field thereof;

[0007] A heating furnace connected to the magnetization device for heat decomposition treatment of PFOS-containing fire-fighting foam treated by the magnetization device;

[0008] A wet absorption device connected to the exhaust gas outlet of the heating furnace for absorbing perfluorocarbon gas generated by the heat decomposition of the PFOS-containing fire-fighting foam.

[0009] Further, the magnetic field strength of the magnetization device is 350mT.

[0010] Further, the magnetization device is a fluid magnetizer, and the fluid magnetizer comprises:

[0011] A permanent magnet alloy shell;

[0012] An inner magnet is arranged in the permanent magnet alloy shell, and a circumferential wall of the inner magnet is provided with a spiral flow thread extending along an axial direction, and a channel for the PFOS-containing fire-fighting foam to flow through is formed between the outer circumferential wall of the inner magnet and the inner circumferential wall of the permanent magnet alloy shell.

[0013] Further, the heating temperature of the heating furnace is 300-900℃, and the heat treatment time is 1-30min.

[0014] Further, the heating furnace is a quartz tube furnace, and the quartz tube furnace comprises:

[0015] A serpentine quartz tube for the PFOS-containing fire-fighting foam to flow through;

[0016] A plurality of thermocouples are installed in the gap outside the serpentine quartz tube.

[0017] Further, the wet absorption device absorbs the perfluorocarbon gas through the saturated Ca(OH)2 solution in the wet absorption device.

[0018] Further, the wet absorption device comprises:

[0019] An absorption tank containing the saturated Ca(OH)2 solution;

[0020] A desiccant is covered on the saturated Ca(OH)2 solution, and the gas absorbed by the saturated Ca(OH)2 solution passes through the desiccant and is discharged.

[0021] Further, the PFOS-containing fire-fighting foam decomposition treatment device further comprises:

[0022] A fire-fighting foam storage tank connected to the magnetization device for storing and supplying the PFOS-containing fire-fighting foam to the magnetization device.

[0023] The application further provides a PFOS-containing fire-fighting foam decomposition treatment method, and the method comprises:

[0024] S1, reducing the molecular force of the perfluorooctane sulfonamide compound molecules in the PFOS-containing fire-fighting foam through the action of a magnetic field;

[0025] S2, heat decomposition treatment of the PFOS-containing fire-fighting foam;

[0026] S3, adsorbing the perfluorocarbon gas generated by the heat decomposition of the PFOS-containing fire-fighting foam.

[0027] By adopting the above technical solution, magnetization can reduce molecular cohesion by breaking the fluorocarbon bonds of PFOS molecules in PFOS-containing fire-fighting foam liquid, thereby making the molecular bonds of PFOS in the PFOS-containing fire-fighting foam liquid easier to break. In addition, the magnetic field breaks the hydrogen bonds between PFOS-containing fire-fighting foam liquid molecules, reducing the cohesive force of the fire-fighting foam liquid. Subsequently, as the temperature increases, more energy makes the chemical bonds of PFOS easier to break, increasing the variety of gaseous products and shortening the carbon chains of the products. Therefore, this invention, by adding a magnetization device before heating decomposition, reduces the molecular force of PFOS in PFOS-containing fire-fighting foam liquid, making the fluorocarbon bonds easier to break, and also breaks the hydrogen bonds between PFOS-containing fire-fighting foam liquid molecules, reducing the cohesive force of the fire-fighting foam liquid. This allows for a lower furnace temperature and a shorter heating time, thereby reducing energy consumption and improving defluorination efficiency. Moreover, the wet absorption device reduces the toxicity of the decomposition products after absorbing the perfluorocarbon gas, making it easier to further treat them using other methods. This invention can be applied to the stabilization treatment of PFOS-containing fire-fighting foam liquid. The development of this technology is beneficial to ensuring ecological safety and has important environmental, social and economic significance, with broad application prospects. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the PFOS-containing fire-fighting foam liquid decomposition and treatment device of the present invention;

[0029] Figure 2 This is a schematic diagram of the magnetization device of the present invention;

[0030] Figure 3 This is a schematic diagram of the structure of the heating furnace of the present invention;

[0031] Figure 4 This is a schematic diagram of the structure of the wet absorption device of the present invention;

[0032] In the diagram, 1. Magnetizing device; 11. Permanent magnet alloy shell; 12. Inner magnet; 121. Flow-through thread; 2. Heating furnace; 21. Serpentine quartz tube; 22. Thermocouple; 3. Wet absorption device; 31. Absorption box; 32. Saturated Ca(OH)2 solution; 33. Desiccant; 4. Fire-fighting foam liquid storage tank; 5. Flow valve. Detailed Implementation

[0033] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0034] In one embodiment, such as Figure 1 , 2 As shown in Figures 3 and 4, a PFOS-containing fire-fighting foam liquid decomposition and treatment device includes:

[0035] The magnetization device 1 is used to reduce the molecular force of the PFOS-containing fire-fighting foam by the magnetic field effect;

[0036] The heating furnace 2 is connected with the magnetization device 1 and used to perform thermal decomposition treatment on the PFOS-containing fire-fighting foam treated by the magnetization device 1.

[0037] The wet absorption device 3 is connected with the waste gas outlet of the heating furnace 2 and used to absorb the perfluorocarbon gas generated by the thermal decomposition of the PFOS-containing fire-fighting foam.

[0038] Specifically, the magnetization can break the fluorocarbon bond of the PFOS in the PFOS-containing fire-fighting foam, so that the molecular force in the perfluorooctane sulfonamide molecule is reduced, and the molecular bond of the PFOS in the PFOS-containing fire-fighting foam is easily broken. In addition, the magnetic field effect cuts off the hydrogen bond between the PFOS-containing fire-fighting foam molecules, reduces the cohesion of the fire-fighting foam, and further increases the energy to make the chemical bond of the PFOS more easily broken, increases the types of gas products, and shortens the carbon chain of the products. Therefore, by installing the magnetization device 1 before heating and decomposition, the molecular force of the PFOS in the PFOS-containing fire-fighting foam is reduced, the fluorocarbon bond is easily broken, the hydrogen bond between the PFOS-containing fire-fighting foam molecules is cut off, the cohesion of the fire-fighting foam is reduced, the temperature of the heating furnace 2 can be reduced, the heating time can be shortened, thereby reducing the energy consumption and improving the defluorination efficiency. Moreover, the toxicity of the decomposition products is reduced after the wet absorption device 3 absorbs the perfluorocarbon gas, and the decomposition products are easily further treated by other methods.

[0039] Both high temperature and magnetization can provide energy to degrade PFOS, and the synergistic effect of the two can improve the degradation rate and efficiency of PFOS. The present embodiment adopts the combination of magnetization and high temperature to maximize the degradation efficiency of PFOS in the PFOS-containing fire-fighting foam, which is environmentally friendly, energy-saving, and emission-reducing, and is conducive to protecting ecological safety.

[0040] Preferably, the magnetic field strength of the magnetization device 1 is 350 mT. The heating temperature of the heating furnace 2 is 300-900℃, and the heat treatment time is 1-30 min. The wet absorption device 3 absorbs the perfluorocarbon gas through the saturated Ca(OH)2 solution 32 therein.

[0041] The perfluorocarbon gas includes C8F 18 , C7F 16 , C6F 14 , C5F 12 , and C4F 10 . The perfluorocarbon gas is a strong greenhouse gas and is harmful to the environment. Therefore, it needs to be absorbed and treated. The saturated Ca(OH)2 solution can absorb the perfluorocarbon gas and react with it to generate calcium fluoride and other products.

[0042] In one embodiment, as shown in Figure 2 Fig. 1, the magnetizing device 1 is a fluid magnetizer, which comprises:

[0043] a permanent magnet alloy shell 11;

[0044] an inner magnet 12, which is arranged in the permanent magnet alloy shell 11, and has a flow-around thread 121 extending along the axial direction, and a channel for the PFOS-containing fire-fighting foam liquid to flow through is formed between the outer circumferential wall of the inner magnet 12 and the inner circumferential wall of the permanent magnet alloy shell 11.

[0045] Specifically, by the cooperation of the permanent magnet alloy shell 11 and the inner magnet 12, a relatively stable 300-350 mT strong magnetic field environment can be formed, and a continuous and effective pulsating cutting magnetization of the fluid is realized, so that the liquid flowing through can obtain a good magnetization effect. In addition, the flow-around thread 121 is further arranged outside the inner magnet 12, which can increase the flow path of the fluid magnetization on the one hand, and increase the turbulence of the fluid on the other hand. In the process of spiral propulsion magnetization, the fluid is more conducive to uniform magnetization compared with the general straight flow type magnetization channel.

[0046] In one embodiment, as shown in Figure 3 Fig. 2, the heating furnace 2 is a quartz tube furnace, which comprises:

[0047] a serpentine quartz tube 21 for the PFOS-containing fire-fighting foam liquid to flow through;

[0048] a plurality of thermocouples 22 installed in the gap outside the serpentine quartz tube 21.

[0049] Specifically, by arranging the serpentine quartz tube 21, the length and flow time of the flow channel of the PFOS-containing fire-fighting foam liquid can be increased without increasing the volume, so that the PFOS-containing fire-fighting foam liquid is thermally decomposed in the process of continuous flow, and the decomposition efficiency is high. The thermocouples 22 are arranged in the gap outside the serpentine quartz tube 21, which can not only prolong the service life of the thermocouples 22 and improve the utilization rate of heat energy, but also can uniformly heat the PFOS-containing fire-fighting foam liquid. In addition, the serpentine quartz tube 21 has the advantages of high temperature resistance, corrosion resistance and good thermal stability.

[0050] In one embodiment, as shown in Figure 4 Fig. 3, the wet absorption device 3 comprises:

[0051] an absorption tank 31, in which a saturated Ca(OH)2solution 32 is contained;

[0052] a desiccant 33, which is covered on the saturated Ca(OH)2solution 32, and the gas absorbed by the saturated Ca(OH)2solution 32 is discharged after passing through the desiccant 33.

[0053] In one embodiment, as shown in Figure 1 The PFOS-containing fire-fighting foam decomposition treatment device further comprises:

[0054] The fire-fighting foam tank 4 is connected to the magnetization device 1 and is used to store and supply the PFOS-containing fire-fighting foam to the magnetization device 1.

[0055] The pipeline connecting the fire-fighting foam tank 4 and the magnetization device 1 is provided with a flow valve 5.

[0056] Preferably, the flow valve 5 controls the PFOS-containing fire-fighting foam to flow through the magnetization device 1 at a speed of 4 m / s.

[0057] In one embodiment, a PFOS-containing fire-fighting foam decomposition treatment method comprises:

[0058] S1, reducing the molecular force of perfluorooctane sulfonamide molecules in the PFOS-containing fire-fighting foam by the action of a magnetic field;

[0059] S2, thermally decomposing the PFOS-containing fire-fighting foam;

[0060] S3, adsorbing the perfluorocarbon gas generated by the thermal decomposition of the PFOS-containing fire-fighting foam.

[0061] The PFOS-containing fire-fighting foam is a PFOS-containing aqueous film-forming foam extinguishing agent.

[0062] The technical solutions involved in the above embodiments will be described in detail below in combination with a specific embodiment.

[0063] As shown in Figure 1As shown, the PFOS-containing fire-fighting foam liquid is from the fire-fighting foam liquid tank 4 and passes through the flow valve 5, which adjusts the flow rate of the fire-fighting foam liquid to 4 m / s and the magnetization device 1 with a magnetic field intensity of 350 mT. When the PFOS-containing fire-fighting foam liquid passes through the magnetic field, the solution molecular movement is intensified due to the effect of the inner and outer magnetic fields, the fluorocarbon bond contained in the PFOS molecular structure is more prone to break, the molecular cluster structure is changed into small molecular groups, and the PFOS molecular cohesion is reduced. In addition, the magnetic field cuts the hydrogen bond between the PFOS-containing fire-fighting foam liquid molecules, reduces the cohesion of the fire-fighting foam liquid, and realizes the continuous and effective pulsating cutting magnetization of the solution in the stable 350 mT strong magnetic field environment, so that the flowing solution obtains good magnetization effect. The magnetized PFOS-containing fire-fighting foam liquid flows into the heating furnace 2, which is a quartz tube furnace. The heating temperature of the heating furnace 2 is set to 300-900℃, and the heat treatment time is 1-30 min. The thermal decomposition product is perfluorocarbon gas, which will cause the greenhouse effect if discharged into the atmosphere, so it needs to be adsorbed. The fluorocarbon gas is collected and absorbed by using a wet absorption method, and the wet absorption liquid is saturated Ca(OH)2 solution. The toxicity of the decomposition product is reduced, and it is easy to further process it by using other methods.

[0064] Based on the above ideal embodiments according to the present application, through the above description, relevant personnel can make various changes and modifications without deviating from the technical idea of the present application. The technical scope of the present application is not limited to the content of the specification, and must be determined according to the scope of the claims.

Claims

1. A PFOS-containing fire-fighting foam decomposition treatment device, comprising: a magnetization device (1) for reducing the molecular force of perfluorooctane sulfonamide molecules in the PFOS-containing fire-fighting foam through the magnetic field effect thereof; a heating furnace (2) connected to the magnetization device (1) for performing thermal decomposition treatment on the PFOS-containing fire-fighting foam treated by the magnetization device (1), the heating temperature being 300-900℃; and a wet absorption device (3) connected to the exhaust outlet of the heating furnace (2) for absorbing the perfluorocarbon gas generated by the thermal decomposition of the PFOS-containing fire-fighting foam, wherein the magnetization device (1) is a fluid magnetizer, which comprises: a permanent magnet alloy shell (11); and an inner magnet (12) arranged in the permanent magnet alloy shell (11), the peripheral wall of the inner magnet (12) being provided with a flow thread (121) extending along the axial direction in a spiral manner, and a channel for the PFOS-containing fire-fighting foam to flow therethrough being formed between the outer peripheral wall of the inner magnet (12) and the inner peripheral wall of the permanent magnet alloy shell (11).

2. The PFOS-containing fire-fighting foam decomposition treatment device according to claim 1, wherein the magnetic field strength of the magnetization device (1) is 350mT.

3. The PFOS-containing fire-fighting foam decomposition treatment device according to claim 1, wherein the heating temperature of the heating furnace (2) is 300-900℃, and the thermal treatment time is 1-30min.

4. The PFOS-containing fire-fighting foam decomposition treatment device according to claim 1, wherein the heating furnace (2) is a quartz tube furnace, which comprises: a serpentine quartz tube (21) for the PFOS-containing fire-fighting foam to flow therethrough; and a plurality of thermocouples (22) installed in the gap outside the serpentine quartz tube (21).

5. The PFOS-containing fire-fighting foam decomposition treatment device according to claim 1, wherein the wet absorption device (3) absorbs the perfluorocarbon gas through the saturated Ca(OH)2 solution (32) therein.

6. The PFOS-containing fire-fighting foam decomposition treatment device according to claim 5, wherein the wet absorption device (3) comprises: an absorption tank (31) containing the saturated Ca(OH)2 solution (32) therein; and a desiccant (33) covering the saturated Ca(OH)2 solution (32), the gas absorbed by the saturated Ca(OH)2 solution (32) being discharged after passing through the desiccant (33).

7. The PFOS-containing fire-fighting foam decomposition treatment device according to claim 1, further comprising: a fire-fighting foam storage tank (4) connected to the magnetization device (1) for storing and supplying the PFOS-containing fire-fighting foam to the magnetization device (1). ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 7. The PFOS-containing fire-fighting foam liquid decomposition treatment apparatus according to claim 1, characterized by ​ ​ 8. A method for decomposing PFOS-containing fire-fighting foam, characterized in that, The method comprises the following steps: S1. Reducing the molecular force of perfluorooctane sulfonamide molecules in the PFOS-containing fire-fighting foam by the action of a magnetic field; S2. Thermally decomposing the PFOS-containing fire-fighting foam; S3. Adsorbing the perfluorocarbon gas generated by the thermal decomposition of the PFOS-containing fire-fighting foam.

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