Adsorbent regeneration method and adsorbent regeneration system

Abstract

To provide a regeneration method and a regeneration system where the adsorptivity of an adsorbent used for the clarification treatment of contaminated air is regenerated in a short time.SOLUTION: An adsorbent regeneration method includes: a heating step where a used adsorbent N1 attached to an inside filter 10 of a regenerator 2 is steamed, the adsorbent N1 is heated and contaminants that the adsorbent N1 adsorbed are released; and a vacuum step where the inside of the regenerator 2 having the filter 10 stored is made vacuum and the balance of the contaminants that the adsorbent N1 has after being heated and moisture are removed.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method and system for regenerating the adsorption performance of an adsorbent used to purify polluted air generated in factories, business establishments, etc. [Background technology]

[0002] Air pollution caused by business activities at factories and workplaces contains volatile organic compounds (VOCs, an abbreviation for Volatile Organic Compounds), nitrogen oxides (NO X ), sulfur oxides (SO X ) may be included in the air pollution. These substances are the cause of PM2.5, and there are regulations on their emission into the atmosphere. These regulations tend to become stricter every year, so it is becoming increasingly important to develop a system to remove these substances from polluted air.

[0003] One method for removing the pollutants from polluted air is to purify the polluted air by passing the polluted air through a filter carrying an adsorbent and allowing the pollutants contained in the polluted air to be adsorbed by the adsorbent. In this method, the adsorbent's ability to adsorb pollutants decreases as the filtration time passes, so it is necessary to restore the adsorption ability of the adsorbent after a certain amount of time has passed.

[0004] For example, in the VOC removal device disclosed in the following Patent Document 1, a zeolite-supported metal filter for VOC removal is installed inside an adsorption tower. In the adsorption process, air containing VOCs is sent to the filter, and the VOCs are adsorbed and removed by the action of the zeolite supported on the filter. Then, the clean air from which the VOCs have been removed is discharged from the VOC removal device. Next, a desorption process is performed, in which the zeolite-supported metal filter for VOC removal is heated to desorb the VOCs adsorbed on the adsorbent.

[0005] According to Patent Document 1, the following effects are said to be achieved: In conventional VOC removal methods, the air volume during desorption is quite small, so it takes a long time to heat the adsorption rotor or adsorbent to a temperature at which the VOCs are desorbed, or the adsorption rotor or adsorbent does not heat up, resulting in insufficient desorption, whereas the VOC removal device in Patent Document 1 is said to be able to efficiently desorb, recover and / or decompose the adsorbed VOCs.

[0006] In addition, the exhaust gas treatment device disclosed in the following Patent Document 2 is a device that flows exhaust gas through a filtration filter to which an adsorbent is attached, causes fine particulate matter in the exhaust gas to be adsorbed by the adsorbent, and at a predetermined stage, peels off the adsorbent and attaches new adsorbent. The adsorbent peeled off from the filter is heated and regenerated in an adsorbent regeneration device, and the regenerated adsorbent is attached again to the filtration filter. It is said that by carrying out such peeling, regeneration, and attachment processes, the adsorbent can be reused.

[0007] In addition, the bag filter and gas removal system using it disclosed in the following Patent Document 3 removes special gases and the like contained in polluted air by forming a precoat layer with a precoat agent on one surface of the pleated filter in advance. It is disclosed that this precoat agent can be reused by a precoat regeneration device. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2007-245039 A [Patent Document 2] Patent Publication No. 2021-084095 [Patent Document 3] JP 2011-041934 A Summary of the Invention [Problem to be solved by the invention]

[0009] As described above, the adsorbent loses its adsorption power as it adsorbs pollutants, and therefore it is necessary to restore the adsorption capacity of the adsorbent. As a method for this, as described in the above Patent Documents 1 to 3, there is a method in which the adsorbent with reduced adsorption capacity is heated to release the pollutants from the adsorbent, thereby restoring the adsorption capacity of the adsorbent.

[0010] However, there was a problem that it took a long time to recover the adsorption capacity of the adsorbent by heating the adsorbent by feeding heated gas to the filter with the adsorbent attached thereto, almost completely releasing the pollutants adsorbed by the adsorbent. For example, according to the experiments of the present inventors, when activated carbon (adsorbent) that had adsorbed toluene (pollutant) was heated with hot air at about 180°C or less, it took about 3 hours for the toluene adsorbed by the activated carbon to be almost completely released.

[0011] On the other hand, by raising the temperature of the hot air to about 230°C, it was possible to shorten the time it took for the adsorbent to almost completely release the pollutants it had adsorbed to about 80 minutes. However, there was a problem in that the filter was damaged by hot air at a high temperature of about 230°C. In other words, when the filter was made of a resin such as polytetrafluoroethylene (also known as Teflon (registered trademark)), there was a problem in that when hot air at a high temperature was applied to the filter, a part of the filter was deformed and clogged.

[0012] When a metal filter is used as in Patent Document 1, there is no problem even if it is heated at high temperatures. However, when a filter made of a material that does not have high heat resistance, such as the above-mentioned resin, is used, there is a problem that it is difficult to heat it at high temperatures.

[0013] Furthermore, as in Patent Document 2, when an external device (such as a heating kiln-type regeneration device exemplified in Patent Document 2) is used to heat the adsorbent after it is peeled off from the filter, there is an advantage that the heating temperature is not restricted as described above. However, since heating kiln-type regeneration devices are generally large, there are problems in that the initial cost is high and the required footprint is large. In addition, a large amount of electricity is required to rotate the large rotating cylinder, which causes problems in that the running cost is high.

[0014] Furthermore, although Patent Document 3 mentions the provision of a precoat regeneration device, it does not disclose anything other than that this precoat regeneration device has a built-in heating classification device, and does not disclose its specific structure, etc.

[0015] The present invention has been made to solve the above problems, and aims to improve the adsorption performance of an adsorbent used in the purification treatment of polluted air. than when the adsorbent is heated with heated air or heated inert gas (e.g., N2). Play in a short time can The present invention aims to provide a playback method and a playback system. [Means for solving the problem]

[0016] The present invention, which has solved the above problems, is as follows.

[0017] (First aspect) 1. A method for regenerating a spent adsorbent used in the purification of polluted air, comprising the steps of: a heating step of applying steam to the used adsorbent attached to a filter inside a regenerator to heat the adsorbent and release the contaminants adsorbed by the adsorbent; a vacuum process for removing the remaining contaminants and moisture contained in the adsorbent after heating by creating a vacuum inside a regeneration device in which the filter is stored; A method for regenerating an adsorbent, comprising the steps of:

[0018] (Action and effect) In this embodiment, the adsorbent attached to the filter is heated by steam to increase the temperature of the adsorbent, causing the adsorbent to release pollutants. When the adsorbent is heated using heated air or heated inert gas (such as N2), it takes a long time for the adsorbent to finish releasing pollutants. If high-temperature air or inert gas (e.g., 300 degrees or higher) is used to shorten this time, a large amount of fuel is required to produce the high-temperature air or inert gas, which results in high running costs.

[0019] Therefore, the inventors have devised a method of using steam to heat the used adsorbent. The use of steam has the advantage that the temperature of the adsorbent can be raised quickly by the condensation heat transfer of the steam (heat transfer using the latent heat released when the steam returns to liquid). In addition, there is an advantage that the running costs can be reduced by not using high-temperature air or inert gas.

[0020] In this embodiment, after the contaminants adsorbed in the adsorbent are released by the heating step, the inside of the regenerator is evacuated in the vacuum step. By evacuating the inside of the regenerator, the small amount of contaminants still remaining in the adsorbent after the heating step can be released from the adsorbent, and the adsorption performance of the adsorbent can be fully restored.

[0021] In addition, when steam is used to heat the adsorbent in the heating step as described above, the steam returns to liquid form, and moisture is generated and adheres to the adsorbent. If the adsorbent remains in a state where it contains a large amount of moisture, there is the disadvantage that the adsorption power is low.

[0022] In this embodiment, the inside of the regenerating apparatus is evacuated in the vacuum step, so that the moisture contained in the adsorbent can be removed, thereby making it possible to avoid the occurrence of the above-mentioned problems.

[0023] In addition, when the adsorbent is heated in the heating step, the product temperature of the adsorbent becomes high. Since an adsorbent with a high product temperature has low adsorption performance for pollutants, the product temperature of the adsorbent must be lowered after the pollutants are released from the adsorbent in the heating step in order to provide the adsorbent with sufficient adsorption performance.

[0024] As in the present embodiment, the adsorbent can be cooled by providing a vacuum process after the heating process and creating a vacuum inside the regeneration device, and therefore the product temperature of the adsorbent can be lowered more quickly than when the product temperature of the adsorbent is allowed to naturally drop to a desired value after the heating process, making it possible to reuse the adsorbent more quickly.

[0025] As described above, according to the present embodiment, the adsorption performance of the adsorbent used in the purification treatment of polluted air can be improved. than when the adsorbent is heated with heated air or heated inert gas (e.g., N2). It can be regenerated in a short time, and the adsorption performance of the adsorbent can be fully restored.

[0026] (Second aspect) An adsorbent regeneration method used in an adsorbent regeneration system including a plurality of the regeneration devices, comprising: Prior to the heating step, A preheating step of preheating the used adsorbent attached to the filter inside the regeneration device with steam to raise the product temperature of the adsorbent, The method for regenerating an adsorbent according to the first aspect, wherein the steam used for the preheating is used as spent steam exhausted from another regeneration device which simultaneously performs the heating step.

[0027] (Action and effect) By preheating the adsorbent before heating it, contaminants are more easily released from the adsorbent, and as a result, the heating step time can be reduced compared to when preheating is not performed.

[0028] In addition, it is preferable to use used steam used in a heating process of another regenerator as the steam for preheating the adsorbent. By reusing used steam in this way, it is not necessary to newly generate steam for preheating, and it is possible to reduce power consumption, etc.

[0029] (Third aspect) Before the preheating step, an impregnation step of impregnating the used adsorbent onto the filter inside the regeneration device, After the vacuum step, a peeling step of peeling off the adsorbent from the filter, the adsorbent having recovered its adsorption capacity by releasing the contaminants; a different step selected from the adhering step, the preheating step, the heating step, the vacuum step, and the peeling step is performed simultaneously for each of the plurality of regenerating apparatuses; The method for regenerating an adsorbent according to the second aspect, wherein each regeneration device moves to the next step at the same time.

[0030] (Action and effect) As in this embodiment, it is preferable that the adhesion step, preheating step, heating step, vacuum step and peeling step are performed simultaneously for each of the multiple regeneration devices, and that the timing of transition to the next step is also synchronized.

[0031] For example, if it is desired to set the time required to regenerate an adsorbent with reduced adsorption capacity to 25 minutes, the time required for each of the impregnation step, preheating step, heating step, vacuum step, and peeling step can be set to 5 minutes. In other words, the time required for each of the steps can be divided almost equally.

[0032] For example, the preheating process in regenerator A and the heating process in regenerator B are carried out simultaneously for 5 minutes, then the process moves to the next process at the same time, and the heating process in regenerator A and the vacuum process in regenerator B are carried out for 5 minutes, etc. The advantages of this method are as follows.

[0033] For example, when performing regeneration treatment of an adsorbent using multiple regeneration devices, a large amount of steam is required if heat treatment is performed simultaneously, so a large steam generating device and a large amount of electricity are required to generate a large amount of steam. In order to avoid such inconvenience, it is preferable to perform the heat treatments in sequence, such as performing the heating step in regeneration device A and then performing the heating step in regeneration device B.

[0034] Unlike the present embodiment, for example, in a process in which only the heating step is performed without the preheating step or the vacuum step, it takes at least 15 minutes to complete the heating step. Therefore, during the 15 minutes during which the heating step is performed in the regenerator A, the heating step cannot be started in the regenerator B. In other words, a 15-minute waiting time occurs before the heating step can be started in the regenerator B.

[0035] On the other hand, by dividing the regeneration process of the used adsorbent into the above-mentioned five steps (the impregnation step, the preheating step, the heating step, the vacuum step, and the peeling step) as in this embodiment, the time required for each step can be reduced to about 5 minutes as described above. In this way, since the time required for the heating step in the regeneration device A is only about 5 minutes, the waiting time until the heating step can be started in the regeneration device B is shortened to about 5 minutes. Moreover, during the 5 minutes in which the heating step is being performed in the regeneration device A, the regeneration device B can also perform a preheating step in which the adsorbent in the regeneration device B is preheated using the used steam exhausted from the regeneration device A, so that the waiting time until the regeneration device B starts the heating step can also be effectively utilized.

[0036] As a result, according to this aspect, the time required to regenerate the adsorption capacity of the used adsorbent in a plurality of regeneration devices can be significantly shortened.

[0037] (Fourth aspect) Before the preheating step, an impregnation step of impregnating the used adsorbent onto the filter inside the regeneration device, After the vacuum step, a peeling step of peeling off the adsorbent from the filter, the adsorbent having recovered its adsorption capacity by releasing the contaminants; The peeling step and the attaching step are integrated into one peeling / attaching step, a different step selected from the preheating step, the heating step, the vacuum step, and the peeling / attaching step is performed simultaneously for each of the plurality of regeneration devices; The method for regenerating an adsorbent according to the second aspect, wherein each regeneration device moves to the next step at the same time.

[0038] (Action and effect) The time required for each of the impregnation step and the peeling step may be shorter than the time required for each of the preheating step, the heating step, and the vacuum step. For example, when the preheating step takes about 5 minutes, the heating step takes about 5 minutes, and the vacuum step takes about 5 minutes, the impregnation step may take only about 2 minutes 30 seconds, and the peeling step may take only about 2 minutes 30 seconds. For example, when the amount of air used to impregnate the used activated carbon in the impregnation step is large, or when the amount of air used to peel the regenerated activated carbon from the filter in the peeling step is large, the time required for the impregnation step and the peeling step will be shorter.

[0039] In such a case, assuming that the times required for the adhesion step, preheating step, heating step, vacuum step, and peeling step are all uniform, as in the third embodiment, a waiting time of approximately 2 minutes and 30 seconds is actually required in each of the adhesion step and peeling step, and therefore the total time required from the adhesion step to the peeling step becomes longer.

[0040] In such a case, it is preferable to integrate the peeling process and the impregnation process into a peeling / impregnation process. For example, while the preheating process is performed for 5 minutes in regenerator A, the heating process is performed for 5 minutes in regenerator B, and the vacuum process is performed for 5 minutes in regenerator C, the peeling process of peeling off the regenerated activated carbon is performed for 2 minutes 30 seconds in regenerator D, and immediately thereafter, the impregnation process of impregnating new used activated carbon to the filter is performed for 2 minutes 30 seconds. By adopting such an embodiment, while the preheating process is performed for 5 minutes in regenerator A, the heating process is performed for 5 minutes in regenerator B, and the vacuum process is performed for 5 minutes in regenerator C, both the peeling process and the impregnation process can be completed in regenerator D.

[0041] As a result, the waiting time occurring in the peeling and adhering steps is eliminated, and the total time required for a series of steps from the adhering step to the peeling step can be shortened to, for example, about 20 minutes (including the adhering step of about 2 minutes and 30 seconds, the preheating step of about 5 minutes, the heating step of about 5 minutes, the vacuum step of about 5 minutes, and the peeling step of about 2 minutes and 30 seconds). In other words, the regeneration efficiency of the used adsorbent can be further improved compared to the third embodiment.

[0042] (Fifth aspect) a regeneration device that includes a filter to which used adsorbent is attached, heats the adsorbent with steam to release the contaminants adsorbed by the adsorbent, and recovers the adsorption capacity of the adsorbent; a vacuum device that creates a vacuum state inside the regeneration device in which the filter is stored, and removes the remaining contaminants and moisture contained in the adsorbent after heating; An adsorbent regeneration system having

[0043] (Action and effect) As an adsorbent regeneration system, the same effects as those of the first aspect are achieved.

[0044] (Sixth aspect) A plurality of the playback devices are provided, a steam recycle line for sending used steam used in heating the adsorbent in one of the regenerators to another of the regenerators; The adsorbent regeneration system of the fifth aspect, wherein the used steam sent to the other regenerator through the steam reuse line is used to preheat the adsorbent inside the other regenerator.

[0045] (Action and effect) As an adsorbent regeneration system, the same effects as those of the second aspect are achieved. Effect of the Invention

[0046] According to the present invention, the adsorption performance of the adsorbent used in the purification treatment of polluted air is than when the adsorbent is heated with heated air or heated inert gas (e.g., N2). It can be played back in a short time. [Brief description of the drawings]

[0047] [Figure 1] 1 is an overall configuration diagram of an adsorbent regeneration system according to the present invention. [Diagram 2] 1 is a schematic cross-sectional view showing a regenerating apparatus and the surrounding area of ​​the regenerating apparatus. Arrows indicate the flow of steam and air in an impregnation step, a preheating step, a heating step, and a vacuum step. [Diagram 3] 1 is a schematic cross-sectional view showing a regenerator and the surrounding area of ​​the regenerator. 2 is a diagram showing the flow of backwash gas during a stripping process. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0048] Hereinafter, a preferred embodiment of the present invention will be described. Note that the following description and drawings merely show one embodiment of the present invention, and the contents of the present invention should not be interpreted as being limited to this embodiment.

[0049] (Adsorbent regeneration system 1) The adsorbent regeneration system 1 regenerates the adsorption capacity of the adsorbent N1 used in the purification device 40. The overall configuration diagram of the adsorbent regeneration system 1 according to the first embodiment is shown in FIG. 1. The adsorbent regeneration system 1 has five regeneration devices 2 arranged in parallel. The adsorbent regeneration system 1 further has a solid-gas separation device 4 that separates the used adsorbent N1 discharged from the purification device 40 from the gas used to transport the adsorbent N1, a used adsorbent storage tank 3 that stores the used adsorbent N1 separated by the solid-gas separation device 4, a steam generation device 9 that generates steam to be sent to the regeneration device 2, a vacuum device 6 that puts the inside of the regeneration device 2 into a vacuum state, and a stripping device 7 that strips the regenerated adsorbent from a filter 10 provided in the regeneration device 2.

[0050] (Purification device 40) Next, the process by which the used adsorbent N1 to be supplied to the adsorbent regeneration system 1 is generated will be described.

[0051] The used adsorbent N1 is generated, for example, by the operation of a purification device 40. The type of purification device 40 is not particularly limited, but an example of the purification device 40 is a device that purifies polluted air generated in a factory or business site and exhausts the purified air to the outside. Such polluted air contains the above-mentioned VOCs, NO X , S.O. X It often contains contaminants such as

[0052] In order to purify these pollutants, for example, a filter 41 is provided inside the purification device 40, and an adsorbent N capable of adsorbing pollutants is adsorbed onto the surface (e.g., the outer surface) of this filter 41, forming an adsorbent layer on the surface of the filter. Thereafter, by passing polluted air through the filter 41, the pollutants contained in the polluted air come into contact with the adsorbent N, are attracted to the adsorbent by van der Waals forces, and are adsorbed and captured by the pores of the adsorbent N particles.

[0053] As the purification process of the polluted air continues and the adsorbent N adsorbs pollutants, the adsorption capacity of the adsorbent N gradually decreases. There are various methods for detecting the degree of decrease in the adsorption capacity of the adsorbent N. For example, a concentration meter that detects the concentration of pollutants in the purified air is provided in the path of the purified air, and the concentration meter is used to measure the concentration of pollutants contained in the purified air, thereby making it possible to detect the degree of decrease in the adsorption capacity of the adsorbent.

[0054] After a certain period of time has elapsed, when the concentration of pollutants contained in the purified air discharged from the purification device 40 exceeds a preset allowable value, or when the concentration of the pollutants approaches the allowable value, the purification process is stopped and a process of regenerating the adsorption capacity of the adsorbent N is performed.

[0055] Specifically, the adsorbent N is peeled off from the filter 41 in the purification device 40, and the peeled adsorbent N is sent to the adsorbent regeneration system 1, where the adsorbent regeneration system 1 restores the adsorption capacity of the adsorbent N.

[0056] The adsorbent N whose adsorption capacity has decreased due to use is referred to as used adsorbent N1 and is sent to the adsorbent regeneration system 1. Examples of the types of used adsorbent N1 include activated carbon, zeolite, hydrated lime, activated manganese dioxide, iron, amine, and silica gel.

[0057] The type of adsorbent N is determined appropriately depending on the type of pollutant contained in the polluted air. In many cases, the pollutant contained in the polluted air is identified, and an adsorbent N with a high adsorption capacity for that pollutant is used.

[0058] (Playback device 2) In the adsorbent regeneration system 1 according to the first embodiment, five regenerators 2 are arranged in parallel. In the following description, they are referred to as a first regenerator 2A to a fifth regenerator 2E in order from the left to the right in the drawing.

[0059] As shown in Figs. 2 and 3, a filter 10 is provided inside each regenerator 2. The filter 10 has a membrane with air and steam permeable holes formed on the side wall, and a passage 12r for air and steam formed in the center. The shape of the filter 10 is not particularly limited, but for example, a cylindrical filter 10 with a honeycomb membrane can be used. The filter 10 can be arranged with its central axis aligned along the vertical direction HD of the regenerator 2. In the embodiment shown in Figs. 2 and 3, a bottom plate 16 is provided to cover the entire lower surface of the filter 10, so that air and steam do not enter the passage 12r without passing through the membrane (taking a shortcut). In the embodiment shown in Figs. 2 and 3, the upper part of the passage 12r of the filter 10 is open, so that the air and steam that have passed through the membrane can be discharged to the outside of the regenerator 2.

[0060] Although there is no particular limitation on the material of the membrane constituting the filter 10, it is preferable to use a material that is excellent in heat resistance and is not easily hydrolyzed, taking into consideration that high-temperature steam passes through the filter 10. Specifically, it is preferable to use ceramic, stainless steel, etc.

[0061] A large number of used adsorbents N1 are attached to the outer surface of the membrane constituting the filter 10 so as to cover the entire outer surface of the membrane.

[0062] 2 and 3, the upper surface of the filter 10 is attached to an upper plate 11, and the filter 11 is supported in the regenerator 2 by this upper plate 11. The peripheral portion of the upper plate 11 is attached to the inner surface of the container 18 of the regenerator 2, and a through hole 27 is provided in the center of the upper plate 11. Air and steam that have flowed upward US through the passage 12r pass through this through hole 27 and flow out into the upper passage 19. In addition, a nozzle 13 that sprays backwash gas is provided in the center of the through hole 27.

[0063] (Regeneration of the adsorption capacity of used adsorbent N1) Next, a process for regenerating the adsorption capacity of the used adsorbent N1 will be described. This regeneration process includes a heating process in which steam is sent to the filter 10 to which the used adsorbent N1 is attached, the used adsorbent N1 is heated by the steam, and the contaminants adsorbed by the used adsorbent N1 are released, and a vacuum process is performed after the heating process in which gas (e.g., air) inside the regeneration device 2 in which the filter 10 is stored is exhausted from the regeneration device 2 to create a vacuum state inside the regeneration device 2, thereby releasing the remaining contaminants adsorbed by the used adsorbent N1.

[0064] In addition, the regeneration process preferably includes a preheating process prior to the heating process. In this preheating process, the heating process is performed simultaneously in a regeneration device 2 other than the regeneration device 2 performing the preheating process, and the used steam exhausted from the regeneration device 2 performing the heating process is sent to the filter 10 to which the used adsorbent N1 is attached in the regeneration device 2 performing the preheating process to preheat the used adsorbent N1, thereby increasing the product temperature of the used adsorbent N1. By providing such a preheating process and preheating the used adsorbent N1 before heating it, contaminants are easily released from the used adsorbent N1 in the heating process. As a result, the regeneration time of the used adsorbent N1 can be shortened compared to the case where preheating is not performed.

[0065] Furthermore, the regeneration process includes an attachment process for attaching the used adsorbent N1 to the filter 10 as a process before the heating process (or as a process before the preheating process if a preheating process is performed), and a peeling process for peeling the regenerated adsorbent N2 from the filter 10 as a process after the vacuum process.

[0066] Therefore, in the following description, each step will be described in detail in the order of the adhering step, the preheating step, the heating step, the vacuum step, and the peeling step.

[0067] (attaching process) The used adsorbent N1 discharged from the regeneration device 40 is sucked by the used adsorbent suction blower 20 and guided to the solid-gas separator 4. Then, the used adsorbent N1 is separated from air by a filter 4a disposed inside the solid-gas separator 4.

[0068] The air referred to here is the air in the piping between the purification device 40 and the solid-gas separator 4, and this air is guided to the solid-gas separator 4 together with the used adsorbent N1 by the used adsorbent suction blower 20.

[0069] The used adsorbent N1 attached to the outer surface of the filter 4a is peeled off from the filter 4a by backwash gas at a predetermined timing. The used adsorbent N1 peeled off from the filter 4a is stored in a used adsorbent storage tank 3 that stores the used adsorbent N1.

[0070] In the impregnation step, a part (or the whole) of the used adsorbent N1 in the used adsorbent storage tank 3 is sent to the regenerator 2.

[0071] Specifically, when the impregnation step is performed, the used adsorbent introduction valve d, the transport gas exhaust valve f, and the adsorbent supply valve j are opened, and the other valves are closed.

[0072] Thereafter, the used adsorbent transport blower 21 is operated. Then, the used adsorbent transport blower 21 sends the used adsorbent N1 discharged from the used adsorbent supply device 3 to the regeneration device 2. When the used adsorbent N1 is sent to the regeneration device 2, air is also sent to the regeneration device 2 together with the used adsorbent N1. This air has the function of transporting the used adsorbent N1 to the regeneration device 2, and in the following description, this air is called transport air. The transport air (containing the used adsorbent N1) supplied to the regeneration device 2 flows from the outside to the inside of the filter 10, enters the passage 12r, flows upward US through the passage 12r, and is exhausted to the outside of the regeneration device 2 through the through hole 27 and the upper passage 19. When the transport air passes through the filter 10, the used adsorbent N1 contained in the transport air adheres to the outer surface of the filter 10, forming an adsorbent layer on the outer surface of the filter 10. Then, for example, the adsorbent attachment step is terminated when an adsorbent layer is formed on most of the outer surface of the filter 10 .

[0073] (Preheating process) After the impregnation step is completed, it is preferable to carry out a preheating step in which the used adsorbent N1 impregnated on the filter 10 in the regenerator 2 is preheated. When carrying out this preheating step, first, the preheated steam supply valve b and the high concentration steam exhaust valve g are opened, and the other valves are closed. When the used steam discharged from another regenerator 2 carrying out a heating step is supplied to the regenerator 2 carrying out the preheating step, the steam supply valve a of the other regenerator 2 is opened.

[0074] Thereafter, the used steam discharged from another regenerator 2 performing the heating step at the same time is supplied to the regenerator 2 performing the preheating step. For example, in the adsorbent regeneration system 1 shown in FIG. 1, when the preheating step is performed in the regenerator 2A and the heating step is simultaneously performed in the regenerator 2B, it is preferable to send the used steam discharged from the regenerator 2B to the regenerator 2A and use the steam to preheat the used adsorbent N1 in the regenerator 2A. By reusing the used steam in this way, it is not necessary to newly generate steam to be used for preheating, and therefore it is possible to reduce power consumption, etc.

[0075] Steam for preheating supplied into the regenerator 2 (referred to as "preheated steam"; for example, used steam discharged from another regenerator 2 performing a heating process) flows from the outside to the inside of the filter 10 having an adsorbent layer formed on its outer surface. In the process in which the preheated steam passes through the filter 10, the heat possessed by the preheated steam raises the product temperature of the used adsorbent N1. Then, the preheated steam, whose temperature has been reduced by passing through the filter 10, enters the inside of the filter 10, flows upward US through the passage 12r, and is then exhausted to the outside of the regenerator 2 through the through hole 27 and the upper passage 19.

[0076] The temperature of the preheated steam is not particularly limited, but is preferably a temperature that does not damage the filter 10 and can sufficiently preheat the used adsorbent N1. Specifically, it is preferable to use preheated steam at 170 to 60°C, and more preferably to use preheated steam at 150 to 80°C.

[0077] When used heated steam (used steam discharged from another regenerator 2 performing the heating process at the same time) is used as the preheated steam, the preheated steam supplied to the regenerator 2 contains a high concentration of pollutants. Since the used adsorbent N1 in the regenerator 2 during the preheating process has almost no remaining ability to adsorb pollutants, even if the preheated steam passes through the adsorbent layer, most of the pollutants contained in the preheated steam are not adsorbed by the used adsorbent N1, but pass through the adsorbent layer and are discharged from the regenerator 2. Therefore, the preheated steam discharged from the regenerator 2 contains a high concentration of pollutants.

[0078] Therefore, it is preferable to provide a catalytic combustion device 8 downstream of the regenerator 2 and oxidize the pollutants contained in the exhaust gas of the preheated steam by this catalytic combustion device 8. The catalytic combustion device 8 has the advantage of being able to reduce combustion costs because it can oxidize pollutants at a lower temperature than a direct combustion device. In addition, it can also reduce the amount of nitrogen oxides generated during combustion.

[0079] The preheating process has the advantage of being able to synchronize the overall takt time for (1) the attachment process, (2) the preheating process, (3) the heating process, (4) the vacuum process, and (5) the peeling process. For example, as shown in Fig. 1, five regeneration devices 2 are provided, and each regeneration device 2 performs a different process at the same time, and when a predetermined time has passed, each process is changed in sequence during operation, the operation efficiency can be improved.

[0080] Specifically, if each of the steps (1) the attachment step, (2) the preheating step, (3) the heating step, (4) the vacuum step, and (5) the peeling step takes about 5 minutes, it is possible to move to the next step every 5 minutes, but without the preheating step (2), there is an inconvenience that the time of the heating step (3) becomes longer. For example, if the time of the heating step (3) takes 10 minutes, it becomes necessary to adjust the takt time to the longest time, so that each of the times of the attachment step (1), the vacuum step (4), and the peeling step (5) also needs to be 10 minutes. In that case, the total time of the steps (1), (3) to (5) becomes longer. As a result, it takes a long time to recover the adsorption capacity of the used adsorbent N1. That is, there is an inconvenience that it takes a long time to recover the adsorption capacity of the used adsorbent N1 and to make the regenerated adsorbent N2 with the restored adsorption capacity usable again for the purification process of the purification device 40. By providing the preheating step (2), it is possible to prevent such inconvenience from occurring.

[0081] (Heating process) After the preheating step is completed (or after the impregnation step if the preheating step is not performed), a heating step is performed to heat the used adsorbent N1 impregnated on the filter 10 in the regenerator 2. When performing this heating step, the steam supply valve a and the high-concentration steam exhaust valve g are opened, and the other valves are closed.

[0082] In addition, when using used steam for preheating in another regenerator 2, it is preferable to close the high-concentration steam exhaust valve g of the regenerator 2 performing the heating process and open the preheated steam supply valve b and the high-concentration steam exhaust valve g of the regenerator 2 performing the preheating process.

[0083] Next, the steam transport blower 22 is started to send the steam generated in the steam generator 9 to the regenerator 2. The type of this steam transport blower 22 is not particularly limited, but for example, a turbo blower, a roots blower, or the like can be used. The steam generator 9 is a device that generates steam (heated steam) for heating the used adsorbent N1, and the type is not particularly limited, but for example, an electric boiler, a high-frequency heater, or the like can be used.

[0084] The temperature of the steam generated by the steam generator 9 is not particularly limited, but it is preferable to set the temperature at which the used adsorbent N1 can easily release pollutants while avoiding damaging the filter 10.

[0085] Specifically, the temperature of the steam is preferably 105° C. or higher, and more preferably 170° C. or higher. If the temperature of the steam is lower than 105° C., the used adsorbent N1 is less likely to release pollutants, which causes the disadvantage that the heating step takes a longer time.

[0086] On the other hand, it is preferable that the upper limit of the steam temperature be changed depending on the type of filter 10. For example, when filter 10 is made of a metal material such as stainless steel, nickel, or brass, the heat resistance temperature is high. Therefore, when filter 10 is made of a metal material, it is preferable to set the steam temperature to 350° C. or less, and more preferably to 300° C. or less.

[0087] The steam generated in the steam generator 9 is supplied to the regenerator 2 by the blower, and heats the used adsorbent N1 attached to the outer surface of the filter 10. The heated used adsorbent N1 gradually releases the adsorbed pollutants. The steam, accompanied by the pollutants released by the used adsorbent N1, passes through the filter 10 and enters the passage 12r, flows upward US through the passage 12r, and is then exhausted to the outside of the regenerator 2 through the through hole 27 and the upper passage 19.

[0088] Since the exhausted steam contains a high concentration of pollutants, it is preferable to oxidize the pollutants contained in the steam using the catalytic combustion device 8 as described above. It is also preferable to send the used steam to another regenerator 2 that performs a preheating step, and reuse the heat contained in the used steam without leaving any waste.

[0089] The heating process is carried out as described above, and when the heating process is completed, the operation of the blower and the steam generating device 9 is stopped.

[0090] As described above, the use of steam to heat the used adsorbent N1 has the advantage that the product temperature of the used adsorbent N1 can be raised quickly by the condensation heat transfer of the steam. That is, by using steam to heat the used adsorbent N1, the heating time can be shortened compared to the case where the used adsorbent N1 is heated using heated air or heated inert gas (such as N2).

[0091] In addition, for example, saturated steam or superheated steam can be used as the steam for heating the used adsorbent N1. In consideration of heating the used adsorbent N1 in a short time, it is particularly preferable to use superheated steam.

[0092] (vacuum process) After the heating step is completed, a vacuum step is performed to create a vacuum inside the regenerator 2. When performing this vacuum step, the extrusion air supply valve e and the regenerator air exhaust valve h are opened, and the other valves are closed.

[0093] Next, a suction blower as an example of a vacuum device 6 is operated to suck air from within the regenerator 2, creating a vacuum state within the regenerator 2. In the embodiment of FIG. 1, the suction blower sucks a small amount of outside air into the regenerator 2 via the extrusion air supply valve e. By taking in a small amount of outside air into the regenerator 2 in this manner, the air within the regenerator 2 can be exhausted to the outside of the regenerator 2.

[0094] By creating a vacuum state inside the regenerator 2 as described above, it is possible to promote the release of pollutants remaining in the used adsorbent N1 even after the heating process.

[0095] In addition, by using steam in the heating process, the moisture content of the used adsorbent N1 after the heating process is high. Therefore, by performing a vacuum process after the heating process, the moisture contained in the used adsorbent N1 after the heating process can be removed from the adsorbent N1. As a result, the moisture content of the used adsorbent N1 after the heating process can be reduced.

[0096] In addition, since high-temperature steam is used in the heating process, the product temperature of the used adsorbent N1 after the heating process is high. Therefore, by carrying out a vacuum process after the heating process, the product temperature of the used adsorbent N1 after the heating process can be lowered.

[0097] In this manner, the pollutants released from the used adsorbent N1 in the vacuum process pass through the filter 10 together with the air in the regenerator 2, flow upward US through the passage 12r, and are then discharged to the outside of the regenerator 2. Since the air discharged from the regenerator 2 contains low concentrations of pollutants, a filter (not shown) or the like is provided downstream of the regenerator 2, and the pollutants are removed by the filter or the like, and clean air is discharged to the outside of the adsorbent regeneration system 1.

[0098] The vacuum process is performed in this manner, and the operation of the suction blower is stopped when the vacuum process is completed. The decision as to whether or not to end the vacuum process is made, for example, by installing a concentration meter (not shown) that measures the concentration of pollutants contained in the air discharged from the regeneration device 2 at the upstream or downstream of the suction blower, and ending the vacuum process when it is confirmed that the concentration of the pollutants has fallen below a predetermined allowable concentration.

[0099] (Peeling process) After the adsorption capacity of the used adsorbent N1 is sufficiently restored through the vacuum process, a peeling process is performed to peel off the adsorbent layer formed on the outer surface of the filter 10. When performing the peeling process, the adsorbent discharge valve c and the backwash gas supply valve i are opened, and the other valves are closed.

[0100] Next, the peeling device 7 is operated, and the backwash gas is injected from the device 7 into the regenerator 2. The backwash gas injected into the regenerator 2 is sprayed from the nozzle 13, flows downward DS through the passage 12r, and passes through the filter 10 from the inside to the outside. As the backwash gas passes through the filter 10, the adsorbent layer formed on the outer surface of the filter 10 is peeled off. The peeled off adsorbent layer contains a large amount of adsorbent N2 (referred to as "regenerated adsorbent") whose ability to adsorb pollutants has been restored.

[0101] The regenerated adsorbent N2 discharged from the regenerator 2 is transported to a regenerated adsorbent storage tank 45. A filter 46 is disposed inside the regenerated adsorbent storage tank 45, and the backwash gas and the regenerated adsorbent N2 are separated by this filter 46. The regenerated adsorbent N2 adheres to the outer surface of the filter 46, is peeled off from the filter 46 at a predetermined timing, and is deposited at the bottom of the regenerated adsorbent storage tank 45.

[0102] The regenerated adsorbent N2 accumulated in the lower part of the regenerated adsorbent storage tank 45 is sent to the purification device 40 at a predetermined timing and is reused in the purification process in the purification device 40.

[0103] (Various valves) In the above description, the opening and closing of various valves in each process, i.e., the impregnation process, the preheating process, the heating process, the vacuum process, and the stripping process, has been described. The opening and closing of various valves in this description is limited to valves that directly act on the regenerator 2 that performs each process, i.e., impregnation, preheating, heating, vacuum, and stripping. For example, when there are multiple regenerators 2 as in the adsorbent regeneration system 1 shown in FIG. 1, there are multiple valves of the same type around them. Specifically, in the adsorbent regeneration system 1 in FIG. 1, there are five valves a1 to a5, including only the steam supply valve a. In this adsorbent regeneration system 1, when the heat treatment of the regenerator 2A is performed and the heat treatment of the regenerators 2B to 2E is not performed, only the steam supply valve a1 that exists around the regenerator 2A and that directly acts on the heat treatment of the regenerator 2A is opened, and the other heated gas supplies a2 to a5 that are not related to the heat treatment of the regenerator 2A are closed. The same can be said for the other valves.

[0104] (Rotation between playback devices 2A to 2E) Next, with reference to the adsorbent regeneration system 1 shown in FIG. 1 and Table 1, the rotation among the regeneration devices 2A to 2E will be described.

[0105] In the adsorbent regeneration system 1 shown in Fig. 1, five regeneration devices 2A to 2E are used and are operated in rotation to perform the above-mentioned (1) attachment step, (2) preheating step, (3) heating step, (4) vacuum step, and (5) peeling step. This rotation can be performed, for example, as shown in Table 1.

[0106] [Table 1]

[0107] That is, in the first stage, the attachment process is performed in the regenerator 2A, the preheating process in the regenerator 2B, the heating process in the regenerator 2C, the vacuum process in the regenerator 2D, and the peeling process in the regenerator 2E. After a predetermined time (e.g., 5 minutes) has elapsed, the process moves to the second stage. That is, in the second stage, the peeling process is performed in the regenerator 2A, the attachment process is performed in the regenerator 2B, the preheating process is performed in the regenerator 2C, the heating process is performed in the regenerator 2D, and the vacuum process is performed in the regenerator 2E.

[0108] In this way, the stages are shifted one after another every time a predetermined time (for example, 5 minutes) has elapsed. Specifically, in the third stage, a vacuum process is performed in the regenerator 2A, a peeling process is performed in the regenerator 2B, an adhesion process is performed in the regenerator 2C, a preheating process is performed in the regenerator 2D, and a heating process is performed in the regenerator 2E. In the fourth stage, a heating process is performed in the regenerator 2A, a vacuum process is performed in the regenerator 2B, a peeling process is performed in the regenerator 2C, an adhesion process is performed in the regenerator 2D, and a preheating process is performed in the regenerator 2E. In the fifth stage, a preheating process is performed in the regenerator 2A, a heating process is performed in the regenerator 2B, a vacuum process is performed in the regenerator 2C, a peeling process is performed in the regenerator 2D, and an adhesion process is performed in the regenerator 2E. Then, after the fifth stage is completed, the process may be returned to the first stage again.

[0109] The opening and closing operations of the valves a to i in the regenerators 2A to 2E at each stage may be performed as shown in Table 1.

[0110] Furthermore, various devices (steam generating device 9, blowers, etc.) can be operated continuously without being stopped, so that the operating efficiency can be improved and power saving can be achieved.

[0111] (peeling and attachment process) In the above explanation, the case where the attachment step is performed after the peeling step has been described. However, the present invention is not limited to this embodiment, and the peeling step and the attachment step may be integrated as in the fourth embodiment, forming a peeling-attaching step. In this case, one step is reduced from the above-mentioned steps, resulting in four steps in the following order: (1) preheating step, (2) heating step, (3) vacuum step, and (4) peeling-attaching step.

[0112] (Other embodiments) In the embodiment shown in FIG. 1, the piping is arranged so that the used steam used in the regenerator 2B is used to preheat the regenerator 2A, the used steam used in the regenerator 2C is used to preheat the regenerator 2B, the used steam used in the regenerator 2D is used to preheat the regenerator 2C, the used steam used in the regenerator 2E is used to preheat the regenerator 2D, and the used steam used in the regenerator 2A is used to preheat the regenerator 2E. However, the arrangement of the piping is not limited to this form. For example, the piping may be arranged so that the used steam used in the regenerator 2B can be used to preheat any regenerator (regenerator 2C, 2D, 2E) other than the regenerator 2A. This is also true when the used steam used in the regenerators 2A, 2C, 2D, 2E is used in another regenerator, and the destination of the used steam is not limited to the regenerator shown in FIG. 1. [Explanation of symbols]

[0113] 1...adsorbent regeneration system, 2...regeneration device, 3...used adsorbent storage tank, 4...solid-gas separation device, 4a...filter (of solid-gas separation device), 5...regenerated adsorbent storage tank, 6...vacuum device, 7...peeling device, 8...catalytic combustion device, 9...steam generating device, 10...filter (of regeneration device), 11...upper plate, 12r...passage, 13...nozzle, 16...bottom plate, 18...container (of regeneration device), 19...upper passage, 20...used adsorbent suction blower, 21...used adsorbent transport blower, 22...steam transport blower, 27...through hole, 40...purification device, 41...filter (of purification device), 45...regenerated adsorbent storage tank Retention tank, 46...filter (of regenerated adsorbent storage tank), HD...height direction, US...upper, DS...lower, a...steam supply valve, b...preheating steam supply valve, c...adsorbent discharge valve, d...used adsorbent input valve, e...extrusion air supply valve, f...transport gas exhaust valve, g...high-concentration steam exhaust valve, h...regenerator air exhaust valve, i...backwash gas supply valve, j...used adsorbent supply valve, k...used adsorbent transport valve after solid-gas separation, m...used adsorbent transport valve, n...regenerated adsorbent supply valve, N...adsorbent, N1...used adsorbent, N2...regenerated adsorbent

Claims

1. 1. A method for regenerating a spent adsorbent used in the purification of polluted air, comprising the steps of: a heating step of applying steam to the used adsorbent attached to a filter inside a regenerator to heat the adsorbent and release the contaminants adsorbed by the adsorbent; a vacuum process for removing the remaining contaminants and moisture contained in the adsorbent after heating by creating a vacuum inside a regeneration device in which the filter is stored; A method for regenerating an adsorbent, comprising the steps of:

2. An adsorbent regeneration method used in an adsorbent regeneration system including a plurality of the regeneration devices, comprising: Prior to the heating step, A preheating step of preheating the used adsorbent attached to the filter inside the regeneration device with steam to raise the product temperature of the adsorbent, 2. The method for regenerating an adsorbent according to claim 1, wherein the steam used for preheating is used as spent steam exhausted from another regenerator which simultaneously carries out the heating step.

3. Before the preheating step, an impregnation step of impregnating the used adsorbent onto the filter inside the regeneration device, After the vacuum step, a peeling step of peeling off the adsorbent from the filter, the adsorbent having recovered its adsorption capacity by releasing the contaminants; a different step selected from the adhering step, the preheating step, the heating step, the vacuum step, and the peeling step is performed simultaneously for each of the plurality of regenerating apparatuses; 3. The method for regenerating an adsorbent according to claim 2, wherein each regeneration device moves to the next step at the same time.

4. Before the preheating step, an impregnation step of impregnating the used adsorbent onto the filter inside the regeneration device, After the vacuum step, a peeling step of peeling off the adsorbent from the filter, the adsorbent having recovered its adsorption capacity by releasing the contaminants; The peeling step and the attaching step are integrated into one peeling / attaching step, a different step selected from the preheating step, the heating step, the vacuum step, and the peeling / attaching step is performed simultaneously for each of the plurality of regeneration devices; 3. The method for regenerating an adsorbent according to claim 2, wherein each regeneration device moves to the next step at the same time.

5. a regeneration device that includes a filter to which used adsorbent is attached, heats the adsorbent with steam to release the contaminants adsorbed by the adsorbent, and recovers the adsorption capacity of the adsorbent; a vacuum device that creates a vacuum state inside the regeneration device in which the filter is stored, and removes the remaining contaminants and moisture contained in the adsorbent after heating; An adsorbent regeneration system having

6. A plurality of the playback devices are provided, a steam recycle line for sending used steam used in heating the adsorbent in one of the regenerators to another of the regenerators; 6. The adsorbent regeneration system according to claim 5, wherein the used steam sent to the other regenerator through the steam recycle line is used to preheat the adsorbent inside the other regenerator.

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