Method for regenerating adsorbent

Abstract

To provide a method that can remove pollutant containing oil, without imposing environmental burden, without use of large-scale equipment, and without change in adsorptivity.SOLUTION: A method for recycling an adsorbent to adsorb pollutant containing oil includes the steps of: immersing the adsorbent in first wash water containing hydrogen peroxide while injecting bubbles for 15 to 30 minutes; and immersing the adsorbent taken out of the first wash water in second wash water while injecting bubbles for 15 to 30 minutes.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a method for regenerating an adsorbent. [Background technology]

[0002] Exhaust gases emitted from factories, incinerators, thermal power plants, road tunnels, etc. contain pollutants that pollute the air, such as nitrogen dioxide (NO2). Therefore, before the gas is released into the atmosphere, the pollutants are removed using adsorbents such as activated carbon.

[0003] The adsorbent has pores, and the pollutants adhere to the pores, removing the pollutants from the exhaust gas. The adsorbent can be regenerated by removing the adhered pollutants, and can be reused.

[0004] Known methods for regenerating adsorbents include a thermal regeneration method in which activated carbon is carbonized and activated at high temperatures of 800°C to 900°C using a fluidized transport furnace, fluidized furnace, rotary kiln, or the like, to restore the performance of the activated carbon (see, for example, Patent Document 1 and Non-Patent Document 1).Other known methods include a regeneration method using an organic solvent (see, for example, Patent Documents 2 and 3) and a regeneration method using microbial decomposition (see, for example, Patent Document 4). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-4511 [Patent Document 2] Japanese Patent Application Publication No. 57-46894 [Patent Document 3] Japanese Patent Application Publication No. 10-57808 [Patent Document 4] Patent No. 3560474 [Non-patent literature]

[0006] [Non-Patent Document 1] Hirohei Urano, "Regeneration Technology of Activated Carbon for Water Treatment," Chemical Engineering, Society of Chemical Engineers, 1973, Vol. 37, No. 7, pp. 677-683 Summary of the Invention [Problem to be solved by the invention]

[0007] However, the regeneration methods using organic solvents and microbial decomposition are limited to removing substances that are soluble in organic solvents or can be metabolized, and are not suitable for removing oils attached to adsorbents. On the other hand, the thermal regeneration method can remove oils attached to adsorbents, but it requires high-temperature heating using fuel, which places a burden on the environment and requires large-scale equipment. In addition, it affects the pores and hardness of the adsorbent, resulting in changes in adsorption performance. [Means for solving the problem]

[0008] The present invention has been made in view of the above-mentioned problems, and provides a method for regenerating an adsorbent that adsorbs oil-containing pollutants, the method comprising: a step of immersing the adsorbent in first cleaning water containing hydrogen peroxide for 15 to 30 minutes while injecting air bubbles; a step of immersing the adsorbent removed from the first cleaning water in second cleaning water for 15 to 30 minutes while injecting air bubbles; A regeneration method is provided, including: [Effects of the Invention]

[0009] According to the present invention, it is possible to remove oil-containing contaminants without imposing a burden on the environment, without using large-scale facilities, and without changing the adsorption performance. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram illustrating a fluidized transport furnace used in a conventional thermal regeneration method. [Figure 2] 1 is a diagram illustrating an air purification system. [Figure 3]FIG. 2 is a diagram illustrating a denitrification device that constitutes an air purification system. [Figure 4] FIG. 1 is a diagram showing an example of the configuration of an apparatus for regenerating an adsorbent. [Figure 5] 10 is a flowchart showing the procedure for regenerating an adsorbent. [Figure 6] FIG. 10 shows the results of a test conducted to regenerate an adsorbent using the present regeneration method. [Figure 7] A line graph showing the results shown in Figure 6. [Figure 8] FIG. 1 is a diagram showing the configuration of a test device for conducting a test to confirm the adsorption performance of a regenerated adsorbent. [Figure 9] FIG. 10 is a diagram showing the results of a first confirmation test of adsorption performance. [Figure 10] FIG. 10 is a diagram showing the results of a second confirmation test of adsorption performance. DETAILED DESCRIPTION OF THE INVENTION

[0011] The adsorbent regeneration method of the present invention is a method for regenerating, for reuse, an adsorbent that adsorbs and removes pollutants such as NO2 in exhaust gases emitted by burning fuels such as natural gas, gasoline, light oil, heavy oil, and tar pitch. Pollutants include not only harmful gases such as NO2, but also particulate matter such as soot and oils such as oil mist. Activated carbon can be used as the adsorbent, but it is not limited to activated carbon and may also be silica, zeolite, or the like, as long as it has pores.

[0012] First, a conventional thermal regeneration method will be briefly described with reference to Figure 1. The thermal regeneration method uses a fluidized transport furnace 10 as shown in Figure 1. The method is not limited to the fluidized transport furnace 10, and a fluidized furnace, rotary kiln, or other similar furnace may also be used. In the fluidized transport furnace 10, powdered coal as an adsorbent is supplied from a storage tank 11 to a mixing tube 13 via a metering feeder 12, and then injected into the furnace 14 together with steam. The furnace 14 uses natural gas as fuel, and is burned in a burner 15 that also injects air, heating the powdered coal injected together with the steam. The powdered coal is then cooled with water in a regenerator 16 and collected in a bag filter 17.

[0013] The thermal regeneration method involves using a furnace 14 to bake activated carbon or the like at 800°C to 900°C, removing contaminants attached to its surface and pores (macropores, mesopores, and micropores) through thermal decomposition, and restoring the adsorption and removal performance by regenerating the pores.

[0014] When the adsorbent is activated carbon, it is known that heating at high temperatures of 800 to 900°C causes some of the pores to expand excessively due to reactivation with water vapor or the like, resulting in a decrease in the number of mesopores and micropores that primarily adsorb small gas molecules compared to before heating. Reactivation also has the adverse effect of reducing the hardness of the granular activated carbon. For details of these factors, please refer to the above-mentioned Non-Patent Document 1.

[0015] As shown in Figure 1, the thermal regeneration method requires expensive and large-scale equipment, such as a furnace 14, a regenerator 16, and a bag filter 17, which increases initial and running costs. Furthermore, the thermal regeneration method uses fossil fuels such as heavy oil, generating large amounts of CO2 gas. With global warming becoming a problem in recent years, generating large amounts of CO2 gas places a significant burden on the environment.

[0016] Therefore, the present invention proposes a method that can remove oil-containing contaminants without imposing such an environmental burden, without using large-scale equipment, and without changing the adsorption performance.

[0017] Before explaining this regeneration method, we will explain an air purification system as an example of a system to which this regeneration method can be applied. Air purification systems are installed by connecting them to the exhaust gas lines of power generation and industrial boilers, or to ventilation openings in tunnels through which vehicles pass. Exhaust gases emitted from boilers and exhaust openings contain harmful gases such as NO and NO2, as well as suspended particulate matter (SPM) such as soot. Air purification systems reduce the concentrations of these pollutants in the exhaust gas to below environmental standards and release them into the atmosphere.

[0018] Figure 2 shows an example of the configuration of an air purification system installed at the ventilation opening of a road tunnel. Vehicles 21 travel through road tunnel 20, and exhaust gases from the combustion of gasoline and other fuels are emitted from vehicle 21. The emitted exhaust gases pass through an air purification system installed in ventilation passage 22 and are released into the atmosphere from ventilation tower 23.

[0019] The air purification system includes a ventilation fan 24 that draws in air containing exhaust gases from inside the road tunnel 20, a dust collector 25, a denitration device 26, a silencer 27, and auxiliary equipment 28 such as power supply equipment and control devices. The auxiliary equipment 28 is a power supply equipment, a control panel, etc., and is used to drive and control the ventilation fan 24, the dust collector 25, and the denitration device 26.

[0020] The air purification system removes SPM using a dust collector 25 and removes harmful gases such as NOx using a denitrification device 26. x The dust collector 25 includes a collecting electrode and a discharge electrode. A high-voltage current is passed between the collecting electrode and the discharge electrode, and exhaust gas is passed between them, causing the SPM in the exhaust gas to become electrically charged. The charged SPM is then attracted to and adheres to the collecting electrode, thereby removing the SPM from the exhaust gas. The SPM adhered to the collecting electrode is then removed by hammering or washing with water.

[0021] The denitrification device 26 x The device may be a type that primarily removes NO2 from the exhaust gas, or a type that removes both NO and NO2. A device that removes both NO and NO2 includes an oxidation device that oxidizes NO to generate NO2, a humidification device that improves the adsorption performance of NO2, and an adsorption device that adsorbs and removes NO2. A device that primarily removes NO2 omits the oxidation means and is composed of a humidification device and an adsorption device.

[0022] A denitration device that primarily removes NO2 will be described with reference to Figure 3. The denitration device 26 includes a humidifier 30 and an adsorption device 31. The adsorption device 31 includes adsorption layers 32 filled with multiple stages of adsorbent. The exhaust gas that has passed through the humidifier 30 is supplied to each adsorption layer 32, and as it passes through each adsorption layer 32, NO2 in the exhaust gas is adsorbed and removed by the adsorbent.

[0023] The adsorbent may be a porous material such as activated carbon, zeolite, or silica, which is formed into pellets, for example. Here, the description will be given assuming that a pellet-shaped material based on activated carbon is used.

[0024] Each adsorption layer 32 is provided within a respective adsorption vessel 33. One side of each adsorption vessel 33 is provided with a supply port 34 for receiving exhaust gas, and the other side is provided with an exhaust port 35 for discharging the exhaust gas. The supply port 34 is connected to the bottom of the adsorption layer 32 via a passage 36, and the exhaust port 35 is connected to the top of the adsorption layer 32 via a passage 37. The adsorption layer 32 is a layer in which an adsorbent is packed to a predetermined height on a mesh plate. Therefore, the exhaust gas passes from the supply port 34 through the lower passage 36 from the bottom to the top of the adsorption layer 32, adsorbing and removing NO2 in the exhaust gas during this passage. The exhaust gas that has passed through the adsorption layer 32 is discharged from the exhaust port 35 through the upper passage 37.

[0025] The adsorption device 31 includes a regenerating solution tank 38 and a regenerating solution pump 39. After each predetermined adsorption time has elapsed, or at any time, the regenerating solution stored in the regenerating solution tank 38 is supplied to each adsorption vessel 33 by the regenerating solution pump 39. The regenerating solution is supplied to a height sufficient to immerse the adsorbent. The adsorbent is regenerated by being immersed in the regenerating solution for a certain period of time.

[0026] The regeneration solution can be, for example, an aqueous solution of sodium sulfite (NaSO), which chemically reacts with NO to remove the adsorbed NO. The concentration of NaSO is, for example, 1% by mass (hereinafter simply expressed as %).

[0027] In the adsorption device 31, dampers are provided at the supply ports 34 of all adsorption vessels 33, and after the dampers are closed and the flow of exhaust gas is stopped, the adsorbent is regenerated with the regenerating solution. Note that the adsorbent regeneration is performed without stopping the operation of the air purification system, so the regeneration is performed on each adsorption layer 32 in turn.

[0028] The humidifier 30 does not have to be installed, but if it is not installed, NO2 will only be physically adsorbed into the pores of the adsorbent. On the other hand, if the exhaust gas is humidified by the humidifier 30, in addition to physical adsorption into the pores, liquid-phase adsorption occurs in which NO2 is absorbed into water that has capillary condensed within the pores, improving the adsorption performance.

[0029] The humidifying device 30 can include a spray nozzle that sprays water into the exhaust gas in the form of a mist, a water tank that stores water, and a water supply pump that supplies water from the water tank to the spray nozzle.

[0030] Adsorbents can be reused by regenerating them as needed using a regenerating solution. Therefore, it seems that adsorbents can be used forever by repeatedly regenerating them. However, exhaust gas contains oils such as oil mist, and as they accumulate, they cover the pores and surface of the adsorbent, reducing its adsorption performance. Because oils do not dissolve in the regenerating solution, they cannot be removed by regeneration with the regenerating solution and continue to accumulate in the pores and surface of the adsorbent. For this reason, adsorbents lose their desired adsorption performance after long-term use and must ultimately be disposed of as industrial waste.

[0031] Therefore, the present invention provides a method for regenerating adsorbents that adsorb oil-containing contaminants. This method removes oil that has accumulated in the pores and on the surface of the adsorbent, which cannot be removed by regeneration with a regeneration solution, and allows the adsorbent to be reused. As a result, the amount of adsorbent disposed of as industrial waste can be reduced.

[0032] FIG. 4 is a diagram showing an example of the configuration of an apparatus for regenerating an adsorbent. The regeneration apparatus includes a first container 40, a second container 41, and a blower 42 as an air supply means. Cleaning water is introduced into the first container 40, the pH is appropriately adjusted, and hydrogen peroxide (H2O2) is added. Cleaning water is introduced into the second container 41, and the pH is appropriately adjusted. Cleaning water can be introduced into each container so that the volume ratio of the cleaning water to the adsorbent 43 to be regenerated is 3:1. Note that this volume ratio is an example, and other volume ratios may also be used. However, in order to effectively regenerate while minimizing the amount of cleaning water used, the above-mentioned 3:1 volume ratio is desirable.

[0033] The used adsorbent 43 is first placed in a first container 40. The adsorbent 43 may be placed as is, or may be placed in a net and the net may be placed in the first container 40. Compressed air is supplied from a blower 42 to the first container 40, and air bubbles 45 are blown into the H2O2 solution 44 to perform aeration. The adsorbent 43 is immersed for a predetermined time while aeration is being performed. Here, the blower 42 is used to supply air, but the source of air supply is not limited to the blower 42.

[0034] The adsorbent 43, when immersed in the H2O2 solution 44, oxidizes and decomposes oil adhering to the adsorbent 43. Furthermore, the oil adhering to the adsorbent 43 can be removed from the adsorbent 43 by aeration, and oxygen used for the oxidative decomposition can be supplied to increase the oxygen concentration in the solution. The bubble diameters become smaller in the order of millibubbles, microbubbles, and nanobubbles. The smaller the diameter, the easier it is to remove oil from the adsorbent 43 and the more likely it is to increase the dissolved oxygen concentration. Furthermore, adjusting the pH to the acidic side can promote the oxidative decomposition of H2O2.

[0035] The concentration of H2O2 can be 1% to 5%, preferably 1%. The pH can be adjusted to 3 to 5 using an acidic solution such as hydrochloric acid. The time for immersing the adsorbent 43 in the first container 40 can be 15 to 30 minutes.

[0036] The oil that has peeled off from the adsorbent 43 and floated on the water surface can be removed appropriately by absorbing it with paper, etc. Note that the method for removing the oil is not limited to the method using paper, and other methods may also be used.

[0037] After immersing the adsorbent 43 in the solution in the first container 40 for a predetermined time, it is removed from the solution and placed in the second container 41. Air is also supplied to the second container 41 from the blower 42, and the air bubbles are blown into the cleaning water 46 to perform aeration. Here, air is supplied, but it is not limited to air; oxygen or ozone may be supplied from a cylinder or the like to increase the oxygen concentration in the solution. The adsorbent 43 is immersed for a predetermined time while being aerated. As a result, any oil that has re-adhered to the adsorbent 43 and any H2O2 remaining in the adsorbent 43 are removed by rinsing.

[0038] The pH of the cleaning water 46 in the second container 41 can also be adjusted to 3 to 5 using an acidic solution such as hydrochloric acid. By adjusting the pH to 3 to 5 in this way, the oxidative decomposition of the remaining H2O2 can be promoted and removed. Re-adhered oil can be peeled off and removed by aeration. Oxygen or ozone can also be supplied to the cleaning water 46 in the second container 41 from a cylinder or the like, instead of air from the blower 42.

[0039] If H2O2 remains in the adsorbent 43 after regeneration, NO2 in the exhaust gas is reduced to NO, and the NO is released into the atmosphere without being adsorbed by the adsorbent 43. However, by using the second container 41 and rinsing with cleaning water 46 with adjusted pH, it is possible to remove the redeposited oil and remaining H2O2.

[0040] In this example, two containers are used, but it is also possible to use only one container, and after the removal of oil and oxidative decomposition are completed, recover the adsorbent 43, replace the solution in the container with cleaning water, and then add the adsorbent 43 again and rinse.

[0041] 5 is a flowchart showing the procedure for regenerating the adsorbent 43. The regeneration procedure can be performed whenever it becomes necessary to regenerate the adsorbent 43. For example, the regeneration procedure can be performed when a regeneration period is determined and the procedure is performed when the regeneration period is reached. Before the procedure is performed, the adsorbent 43 is recovered from the adsorption device 31.

[0042] The operation starts at step 100, and in step 101, cleaning water is poured into the first container 40. The cleaning water can be supplied from a water tank using a pump, but is not limited to this. Water at room temperature can be used as the cleaning water. The amount of cleaning water poured can be approximately three times the volume of the adsorbent 43.

[0043] After the cleaning water is poured into the first container 40, in step 102, an acidic solution such as hydrochloric acid is used to adjust the pH of the cleaning water to 3 to 5. Then, H2O2 is added to the cleaning water whose pH has been adjusted. H2O2 is added so that the concentration of H2O2 becomes approximately 1%.

[0044] In step 103, the recovered adsorbent 43 is placed in the first container 40. After the adsorbent 43 is placed, in step 104, air is sent from the blower 42 into the H2O2 solution 44 in the first container 40 to aerate it. The adsorbent is immersed for approximately 15 to 30 minutes while aeration is being performed. The aeration removes oil adhering to the pores and surface of the adsorbent 43, and the oil is oxidatively decomposed by the H2O2 and oxygen supplied by the aeration.

[0045] When the oil is removed by aeration, the removed oil floats to the surface of the solution. In step 105, the oil floating on the surface of the solution is removed using paper or the like. The oil removal can be carried out as needed. When the immersion in the first container 40 for the specified time has ended, in step 106, the adsorbent 43 is recovered from the first container 40.

[0046] Next, in step 107, the same amount of cleaning water as that charged into the first container 40 is charged into the second container 41, and the pH of the cleaning water is adjusted to 3 to 5 using an acidic solution such as hydrochloric acid. Then, in step 108, the adsorbent 43 recovered from the first container 40 is charged into the second container 41. In step 109, air is blown into the cleaning water 46 in the second container 41 from the blower 42 to aerate it. While aerating, the adsorbent is immersed for approximately 15 to 30 minutes. This removes any re-adhered oil or excess H2O2 from the contaminated H2O2 solution (cleaning liquid) 44. After leaving it for a while, and once a specified time has elapsed, the process proceeds to step 110, where the regeneration process is completed.

[0047] After the regeneration operation is completed, the adsorbent 43 is recovered from the second container 41 and returned to the original adsorption layer 32. As described above, the adsorbent 43 is expected to perform liquid-phase adsorption more effectively when it is in a wet state, and therefore, it can be used as the adsorbent 43 in its wet state. The adsorbent 43 may be returned to the original adsorption layer 32 after being dried, for example, by natural drying.

[0048] Here, we conducted a test to regenerate used adsorbent 43 that had actually been used in an air purification system installed in a road tunnel using this method, and from the test results we verified the recovery effect of the adsorbent 43. Activated carbon was used as the main material for the adsorbent 43.

[0049] Room temperature water was used for the cleaning water, and the volume ratio of adsorbent 43 to cleaning water was 1:3. Hydrochloric acid was added to the cleaning water to adjust the pH to 3-5, and H2O2 was added to create a cleaning solution. The H2O2 concentration in the cleaning solution was 1%. Tests were conducted in Case 1, where cleaning was performed once with the cleaning solution and then rinsing, and in Case 2, where cleaning was performed twice with the cleaning solution and then rinsing.

[0050] Figure 6 shows the results of a test to regenerate an adsorbent using this method. Figure 6 shows the pore size distribution measured at each immersion time in Cases 1 and 2, and the calculated recovery amount. The pore size distribution is the value measured for the pore volume distribution of pores with a size of less than 2 nm.

[0051] In Case 2, the first wash was performed by immersing for 15 minutes with aeration, followed by a second wash by immersing for 30 minutes with aeration. The results for Case 2, shown in Figure 6, show the measurements at each immersion time during the second wash.

[0052] The recovery amount is calculated by subtracting the initial value, which is the measurement result of the used adsorbent before cleaning, from the largest value measured at each immersion time. The maximum values ​​of the pore size distribution are the values ​​at immersion times of 15 and 20 minutes for Case 1, and the value at immersion time of 20 minutes for Case 2, and the initial value is the value at immersion time of 0 minutes, so they are calculated to be 0.020 and 0.036, respectively. Figure 7 shows the results shown in Figure 6 as a line graph.

[0053] The pore size distribution of the new adsorbent is approximately 0.1 cm 3 / g, and in Case 1 it is 0.02 cm 3 / g, which means that the recovery is about 20%. 3 / g, which means that the recovery is about 40%. This confirms that immersion twice has about twice the cleaning effect of immersion once.

[0054] For reference, when the H2O2 concentration was 5% and washing was performed twice, the recovery amount was 0.018, which was the same as when washing once with a 1% concentration. From this, it was confirmed that although the H2O2 concentration can be 5%, it is more efficient to limit it to 1%. Furthermore, since about 20% recovery was achieved even after 30 minutes of immersion, it was found that while the immersion time could be set to 15 to 30 minutes, 15 to 20 minutes is more desirable, as it maximizes the recovery amount. Incidentally, the conventional method of heating at 800°C to 900°C and calcining to regenerate only achieved a recovery amount of 0.011, which is not as good as the method described here.

[0055] From the above, it was found that the optimum H2O2 concentration for this method is 1% and the optimum immersion time is 15 to 20 minutes.

[0056] A test was conducted to confirm the NO removal performance of the adsorbent regenerated by this method. The test was conducted using a column test apparatus 50 shown in Figure 8, which used a simulated NO gas. The column test apparatus 50 includes a fan 51, a column 52, and a chamber 53.

[0057] Indoor air is sucked in by a fan 51, NO is supplied from an NO cylinder, and it is oxidized into ozone, and NO x The gas was made into (NO+NO2) gas and used as a low-concentration NO2 test gas. NO2 cylinder gas was injected into the low-concentration NO2 test gas to make it highly concentrated, and this was used as a high-concentration NO2 test gas. The concentration was adjusted using a mass flow meter, and the NO2 gas was x The test conditions were a space velocity (SV), which is the amount of gas passing through the column test device 50 per hour, of 12,000, and the linear velocity was measured using an anemometer 55 installed on the outlet side of the column 52. Straightening plates 56 were installed on the upstream and downstream sides of the column 52 to ensure uniform gas flow within the column 52. The NOx concentration in the gas that passed through the column 52 was measured using an NOx meter 57. The temperature and humidity of the air in the test gas were measured using a thermo-hygrometer 58.

[0058] Figure 9 shows the results of the confirmation test for Case 1 of adsorption performance, and Figure 10 shows the results of the confirmation test for Case 2 of adsorption performance. In Figures 9 and 10, the concentration (ppm), temperature (°C), humidity (%), and linear wind speed (m / s) are average values ​​over one hour. The test was conducted with the inlet NO2 concentration between 0.1 ppm and 1.0 ppm for 12 hours. After that, the inlet NO2 concentration was set to approximately 0.05 ppm as a low concentration condition, and the test was conducted for one hour. After that, the inlet NO2 concentration was set to approximately 1.5 ppm as a high concentration condition, and the test was conducted for one hour.

[0059] 9 and 10, in both cases 1 and 2, the NO2 removal rate was 100%, confirming that the used adsorbent had recovered to removal performance equivalent to that of a new adsorbent.

[0060] As described above, this method uses hydrogen peroxide and aeration to remove oil-containing contaminants through powerful oxidative decomposition. Because this method does not require conventional regeneration furnaces such as kilns, it is possible to significantly reduce initial and running costs. Since it does not involve the combustion of fossil fuels such as heavy oil, there are no CO2 emissions and the environmental impact is extremely small. Furthermore, because it can be achieved using compact equipment and does not require high-temperature heating, there is no reduction in pore size or hardness, and material loss during regeneration is minimal. This contributes to improving the yield of the regeneration process.

[0061] The adsorbent regeneration method of the present invention has been described in detail above with reference to the embodiments shown in the drawings. However, the present invention is not limited to the above-described embodiments, and can be modified within the scope of what a person skilled in the art can conceive, such as other embodiments, additions, modifications, deletions, etc., and any embodiment is within the scope of the present invention as long as it achieves the functions and effects of the present invention. [Explanation of symbols]

[0062] 10...Fluidized transport furnace 11...Storage tank 12...Weigh feeder 13…Mixing tube 14...Furnace 15...Burner 16...Regenerator 17...Bag filter 20...Road tunnel 21...Vehicle 22...Ventilation passage 23...Ventilation tower 24...Ventilation fan 25...Dust collector 26…Denitration equipment 27...Silencer 28...Auxiliary equipment 30…humidifier 31...Adsorption device 32...Adsorption layer 33...Adsorption container 34...Supply port 35…Discharge port 36, 37...Aisles 38…Regeneration solution tank 39...Regenerated solution pump 40...First container 41...Second container 42...Blower 43...Adsorbent 44...H2O2 solution 45...bubbles 46...cleaning water 50...Column test equipment 51...Fan 52...Column 53...Chamber 54, 57…NOx meter 55...Anemometer 56…straightening plate 58…Thermo-hygrometer

Claims

1. 1. A method for regenerating an adsorbent as a porous material for adsorbing oil-containing contaminants, comprising: adjusting the pH of the first wash water to 3 to 5; adding hydrogen peroxide to the first cleaning water, and then immersing the adsorbent in the first cleaning water containing the hydrogen peroxide for 15 to 30 minutes while injecting air bubbles into the first cleaning water; adjusting the pH of the second wash water to 3 to 5; a step of immersing the adsorbent removed from the first cleaning water in the second cleaning water for 15 to 30 minutes while injecting air bubbles; A playback method including:

2. The regeneration method according to claim 1 , wherein the step of immersing in the first washing water is repeated at least twice.

3. 3. The regeneration method according to claim 1, wherein the concentration of the hydrogen peroxide in the first cleaning water is 1% to 5%.

4. The concentration of the hydrogen peroxide in the first cleaning water is 1%; The time for immersing the adsorbent in the first cleaning water is 15 to 20 minutes, 4. The regeneration method according to claim 1, wherein the adsorbent is immersed in the second cleaning water for 15 to 20 minutes.

5. 5. The regeneration method according to claim 1, wherein the gas contained inside the bubbles is any one of air, oxygen, and ozone.

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