How to regenerate activated carbon

Abstract

To regenerate used powder active carbon by microwave heating, and recover / improve adsorptivity.SOLUTION: A method for regenerating active carbon includes the steps of: mounting active carbon having an average particle diameter of 1 to 100 μm on a flat plate; and regenerating the active carbon on the flat plate by microwave heating. The flat plate may be repeatedly moved forward / backward by a belt conveyor or a roller conveyor during the microwave heating. The temperature of the active carbon during the microwave heating may be measured, and microwave irradiation energy may be controlled on the basis of the measurement result.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a regeneration method and a regeneration system for desorbing and separating substances adsorbed on used activated carbon from the activated carbon by microwave heating and restoring the adsorption performance of the activated carbon.

Background Art

[0002] As regeneration furnaces for regenerating activated carbon, large-scale multi-stage furnace type regeneration furnaces with 4 to 8 cylindrical furnace chambers stacked, rotary kiln type regeneration furnaces for medium-sized furnaces, direct current heating superheat type regeneration furnaces for small-sized furnaces heated by electrode energization, etc. are widespread. Currently, all domestic regeneration furnaces are external heating methods using fossil fuels such as heavy oil and gas as heat sources. When regenerating activated carbon by external heating, heat propagates inside by heat conduction, so it has low thermal conductivity and is inefficient for heating large-volume objects, and the heating time requires a long time.

[0003] Also, in conventional heating furnace activated carbon regeneration devices, there is a limit to the particle size that can be regenerated. When regenerating powder products finer than 40 mesh (0.56 mm), especially powdered activated carbon with a particle size distribution of 1 to 100 μm, problems due to dust scattering occur, so it has not been applied to actual devices. Therefore, while granular activated carbon with a large particle size can be recovered after adsorption and heated and regenerated in a regeneration furnace for reuse, powdered activated carbon with a small particle size has been recovered as solid-liquid separation products or dewatered cakes by filtration treatment and discarded as industrial waste after using new products. Alternatively, used powdered activated carbon has been taken for use as livestock feed or soil fertilizer and diverted to low-value-added uses.

[0004] In recent years, with the increasing need for carbon neutrality efforts by 2050 and the penetration of the concept of carbon circular economy, research on microwave heating regeneration that can be converted to non-fossil energy has been advanced. The regeneration method using microwave heating allows the microwave electric field to penetrate into the object to be heated and be converted into thermal energy inside, so internal heating can be achieved in a short time without heat conduction.

[0005] However, microwave heating presented a problem during the scale-up process to actual plants: insufficient measures were taken to address uneven heating, resulting in low recovery performance values ​​for regenerated activated carbon.

[0006] Patent Document 1 describes a method for regenerating activated carbon using microwave heating, in which used activated carbon is stored in a cylindrical heating container, and empty space is provided that exceeds the volume of used activated carbon, thereby enabling uniform microwave irradiation of the activated carbon.

[0007] Patent Document 2 describes a regeneration method for removing carbonized organic matter desorbed from used activated carbon by microwave heating regeneration, which involves blowing in hot water and using the volume expansion when the water turns into steam to achieve a blow-out removal effect.

[0008] Furthermore, Patent Document 3 describes a method in which activated carbon is placed in a circulation path, the activated carbon is heated with microwaves to desorb the adsorbed material from the activated carbon and regenerate the activated carbon, and the mixed gas of the inert gas circulating in the circulation path and the desorbed adsorbed material gas is cooled and condensed to separate and recover the adsorbed material. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2001-89120 [Patent Document 2] Japanese Patent Publication No. 2001-89121 [Patent Document 3] Japanese Patent Application Publication No. 6-31163 [Overview of the project] [Problems that the invention aims to solve]

[0010] This invention has been made in view of the above-mentioned conventional situation, and aims to provide a regeneration method and regeneration system that can regenerate used powdered activated carbon by microwave heating and restore and improve its adsorption performance. [Means for solving the problem]

[0011] [1] A step of placing activated carbon with an average particle size of 1 to 100 μm on a flat plate, A step of regenerating the activated carbon on the flat plate by microwave heating, A method for regenerating activated carbon, which includes [a specific feature / feature].

[0012] [2] The method for regenerating activated carbon according to [1], wherein the flat plate is repeatedly moved forward and backward by a belt conveyor or roller conveyor while microwave heating is being performed.

[0013] [3] The method for regenerating activated carbon according to [1], wherein the temperature of the activated carbon during microwave heating is measured and the microwave irradiation energy is controlled based on the measurement result.

[0014] [4] The method for regenerating activated carbon according to [1], wherein the activated carbon is microwave-heated in a heat treatment box with an oxygen concentration of 2% or less.

[0015] [5] The method for regenerating activated carbon according to [4], wherein the exhaust gas from the heat treatment box is treated and the treated gas is supplied to the heat treatment box.

[0016] [6] The method for regenerating activated carbon according to [1], wherein the height of the activated carbon on the flat plate is made constant by using a leveling plate, and then microwave heating is performed.

[0017] [7] A hopper for supplying activated carbon with an average particle size of 1 to 100 μm onto a flat plate, A leveling plate for adjusting the height of the activated carbon on the aforementioned flat plate to a constant level, A conveying unit that transports the flat plate on which the activated carbon is placed to a heat treatment box, A microwave generator that irradiates microwaves into the heat treatment box, An activated carbon regeneration system comprising

[0018] [8] The conveying unit has a belt conveyor or a roller conveyor, and repeatedly moves forward and backward the flat plate on which the activated carbon is placed in the heat treatment box during the irradiation of microwaves. The activated carbon regeneration system according to [7]. [Advantages of the Invention]

[0019] According to the present invention, used powdered activated carbon can be regenerated by microwave heating, and the adsorption performance can be restored and improved. [Brief Description of the Drawings]

[0020] [Figure 1] It is a schematic configuration diagram of an activated carbon regeneration system according to an embodiment of the present invention. [Figure 2] It is a functional block diagram of a control device. [Figure 3] It is a graph showing an example of the change in microwave irradiation energy during the activated carbon regeneration process. [Figure 4] It is a graph showing an example of the temperature change during the activated carbon regeneration process. [Embodiments for Carrying Out the Invention] [[ID=۳۴]]

[0021] Hereinafter, embodiments will be described with reference to the drawings.

[0022] The activated carbon regeneration system according to the embodiment of the present invention shown in FIG. 1 irradiates used activated carbon with microwaves for heat regeneration, and is particularly suitable for the regeneration of powdered activated carbon with a small particle size.

[0023] The used activated carbon 1 to be regenerated is supplied from the hopper 2 onto the plate 3. The activated carbon 1 is powdered activated carbon with an average particle size of 1 to 100 μm. The average particle size of the powdered activated carbon is the median diameter D measured by a laser diffraction particle size distribution measuring device 50Alternatively, the average particle size obtained by scanning transmission electron microscopy may be used. There are no particular restrictions on the used activated carbon 1 to be recycled, but for example, it should have an iodine adsorption capacity of 50-1800 mg / g and a specific surface area of ​​300-2000 m². 2 It is / g.

[0024] The plate 3 is made of quartz or a metal such as SUS, and is, for example, a rectangular flat plate in plan view. The dimensions of the plate 3 are not particularly limited. A roughly rectangular frame is provided on one main surface (front) of the plate 3, and activated carbon 1 supplied from the hopper 2 is spread inside the frame.

[0025] The plate 3 on which the activated carbon 1 is placed is transported to the heat treatment box 6 by the transport unit 4. The transport unit 4 is, for example, a belt conveyor or a roller conveyor.

[0026] A leveling plate 5 is provided near the hopper 2, and as the plate 3 moves, the height of the activated carbon 1 inside the frame becomes constant.

[0027] When the plate 3 is transported into the heat treatment box 6, the microwave leakage prevention shutter 11 closes, creating a sealed space inside the box. A microwave generator 7 is connected to the heat treatment box 6. Microwaves generated by the microwave generator 7 are guided into the heat treatment box 6 to heat the activated carbon 1 (and plate 3). The microwaves are irradiated from multiple locations on the top of the heat treatment box 6. A microwave source with a frequency of 2.45 GHz and a maximum output of approximately 24 kW is used. An example of a microwave source is a microwave oven.

[0028] The control device 20 controls the microwave irradiation energy. The control method will be described later.

[0029] The heat treatment box 6 may be equipped with a sensor (not shown) for measuring the reflected energy of microwaves. Alternatively, an instrument using the principle of a differential thermometer that can measure the carbonization and carbon dioxide conversion of the adsorbed substance may be installed.

[0030] Furthermore, a propeller 9 that evenly reflects microwaves may be installed inside the heat treatment box 6. The propeller 9 is made of metal, such as SUS. The number of blades on the propeller 9 is not limited, and may be, for example, 2 to 5. Multiple propellers 9 may be installed.

[0031] During microwave irradiation, the plate 3 may be moved back and forth (repeatedly forward and backward) by the transport unit 4 within the heating treatment box 6 at a low speed that does not cause the powdered activated carbon to scatter, thereby suppressing uneven heating.

[0032] The exhaust gas generated during the heating of the activated carbon 1 is discharged by a blower (not shown) through an exhaust pipe 8 connected to the heat treatment box 6. The exhaust gas discharged from the exhaust pipe 8 is measured for TOC (total organic carbon) and wetness using a gas analyzer (not shown). The exhaust pipe 8 is also equipped with a gas flow meter (not shown) to measure the ventilation flow rate of the blower.

[0033] The heat treatment box 6 is connected to a supply pipe (not shown) for supplying nitrogen gas, superheated steam, or carbon dioxide gas. The exhaust gas discharged from the exhaust pipe 8 is treated using known exhaust gas treatment methods such as scrubbing or plasma treatment. Since the treated gas has a low oxygen concentration, it is preferable to return it to the heat treatment box 6. Maintaining a low oxygen concentration in the heat treatment box 6 (for example, 0.2% or less) suppresses the emission of carbon components as carbon dioxide outside the system, thereby improving the recovery rate of recycled products.

[0034] The heat treatment box 6 is equipped with an infrared camera 10 for measuring the temperature of the activated carbon 1 on the plate 3. A heat conduction type thermometer may also be provided for measuring the temperature of the activated carbon 1.

[0035] When the regeneration process of activated carbon 1 is complete, the microwave leakage prevention shutter 11 opens, and the plate 3 is removed from the heat treatment box 6. The regenerated activated carbon 1 is recovered from the plate 3.

[0036] The control device 20 is a computer having a CPU and memory, and as shown in Figure 2, it has the functions of a temperature acquisition unit 21, an exhaust gas component acquisition unit 22, a flow rate acquisition unit 23, a reflected return energy amount acquisition unit 24, and a microwave irradiation energy control unit 25.

[0037] The temperature acquisition unit 21 acquires the temperature of the activated carbon 1 during the regeneration process from an infrared camera 10 or the like.

[0038] The exhaust gas component acquisition unit 22 acquires analysis results of the exhaust gas TOC and wetness concentration from the gas analyzer.

[0039] The flow rate acquisition unit 23 acquires the measurement result of the ventilation flow rate of the blower from the gas flow meter.

[0040] The reflected return energy acquisition unit 24 acquires the measurement result of the reflected return energy of microwaves. The amount of microwave energy consumed is determined from the difference between the irradiation energy and the reflected return energy.

[0041] The activated carbon regeneration method according to this embodiment includes a drying step to remove moisture from used activated carbon, a calcination and desorption step to desorb substances adsorbed on the activated carbon (adsorbed substances) by calcination, a reactivation step to gasify the remaining carbonized adsorbed substances, and a cooling step to cool the activated carbon.

[0042] The microwave irradiation energy control unit 25 determines the state of the activated carbon 1 based on its temperature and exhaust gas components, and decides which process to execute: the drying process, the calcination and desorption process, the reactivation process, or the cooling process. It then outputs a control signal to the microwave generator 7 to adjust the irradiation energy according to the process.

[0043] Figure 3 shows an example of the change in microwave irradiation energy during the regeneration process, and Figure 4 shows an example of the change in the temperature of powdered activated carbon 1 during the regeneration process.

[0044] After purging the heat treatment box 6 with nitrogen, microwave irradiation is started to perform the drying process (period T1 in Figures 3 and 4). During the drying process, the temperature of the activated carbon rises due to microwave irradiation, and the initial moisture evaporates, causing the temperature to stabilize at around 100°C.

[0045] Once the moisture content of the activated carbon has evaporated and the drying process is complete, the temperature rises rapidly to over 100°C. The microwave irradiation energy is reduced to maintain the regeneration temperature at a predetermined temperature, and the calcination desorption process is performed (period T2 in Figures 3 and 4). The predetermined regeneration temperature in the calcination desorption process is set to an optimal temperature according to the amount of adsorbed material and the carbonization rate. For example, the calcination desorption process is performed in a temperature range of 200 to 1400°C, preferably 500 to 1200°C.

[0046] In the initial stages of the calcination and desorption process, microwave energy is used for the desorption reaction of the adsorbed substance. In the latter half of the calcination and desorption process (period T2), after the desorption of the adsorbed substance has progressed to some extent, the irradiation energy is adjusted to a slightly lower level to maintain a constant temperature of the activated carbon. For example, the irradiation energy in the latter half of the calcination and desorption process is adjusted to about 80-95% of the irradiation energy in the first half.

[0047] Based on the exhaust gas analysis results, if the components of the adsorbed substance in the exhaust gas fall below a predetermined value and it is determined that the calcination desorption process is complete, the irradiation energy is increased to raise the regeneration temperature and the reactivation process is performed (period T3 in Figures 3 and 4). The completion of the calcination desorption process may also be determined by monitoring the carbonization removal status using differential heat measurements and the amount of microwave energy consumed. In the reactivation process, the adsorbed material that remained and carbonized in the calcination desorption process is brought into contact with oxidizing gases such as superheated steam, carbon dioxide, or oxygen to gasify it (water gasification reaction), and discharged from the exhaust pipe 8. For example, the irradiation energy in the reactivation process is slightly higher than the irradiation energy in the calcination desorption process, but lower than the irradiation energy in the drying process.

[0048] It is known that the gasification loss of the activated carbon itself can be used as a guideline to determine the upper limit for the temperature and residence time of the reactivation conditions, and that the residence time can be shortened exponentially as the temperature increases.

[0049] Based on the exhaust gas analysis results, when it is determined that the components of adsorbed substances in the exhaust gas are below a predetermined value and the reactivation process is complete, microwave irradiation is stopped and a cooling process is performed (period T4 in Figures 3 and 4) to cool the activated carbon to below 100°C. To avoid a rapid temperature drop, the temperature is gradually lowered by ventilation with a blower in a nitrogen purge atmosphere or a low-oxygen atmosphere of 2% or less. Ventilation may be achieved by circulating the exhaust gas after scrubber treatment.

[0050] This regeneration process can restore used powdered activated carbon to the same adsorption performance as new. Furthermore, applying the same treatment to new powdered activated carbon can further improve its adsorption performance.

[0051] In this embodiment, the powdered activated carbon to be recycled is placed on a plate 3, leveled to a certain thickness, and then irradiated with microwaves, thereby suppressing ignition and uneven heating caused by the scattering of fine powder. Furthermore, the temperature of the activated carbon on the plate 3 and the exhaust gas components are monitored by instruments during the recycling process, and the microwave irradiation energy is controlled, thereby improving the quality of the recycled product. The ability to recycle powdered charcoal allows it to be reused as high-value recycled powdered charcoal in food processing steps, resulting in cost reductions compared to using new charcoal.

[0052] In conventional activated carbon regeneration processes using heat transfer from an external source, heat loss occurs not only due to the heating of the used activated carbon but also due to the heating of the heating furnace itself and heat transfer to the surroundings. However, in the microwave irradiation method of this embodiment, the activated carbon 1 is heated directly, and heat transfer is mainly to the plate 3 in contact with the activated carbon 1, thus enabling efficient heating and regeneration. Therefore, the amount of CO2 generated by microwave heating, calculated from the electricity consumption, is expected to be significantly reduced compared to the amount of CO2 generated by conventional external heating methods, calculated from fossil fuels such as gas and heavy oil.

[0053] Heating and regeneration using microwave irradiation enables a shift to non-fossil energy sources, and depending on the type of electricity used, carbon neutrality may be possible. Furthermore, it is expected to reduce CO2 emissions through the recycling of used activated carbon, or secondarily reduce the carbon footprint of customers' manufactured products.

[0054] Conventionally, the regeneration control temperature was managed uniformly within a temperature range of 800-850°C for generality. However, in this embodiment, the optimal regeneration temperature can be set based on thermal difference measurement and detachment endpoint prediction, making regeneration possible even at 500-600°C, thus enabling energy savings through thermal energy conservation.

[0055] In the above embodiment, the used powdered activated carbon to be recycled may be powdered activated carbon alone, or it may be mixed with a filter material used in pre-coat filtration for decolorization processes or other adsorption treatment processes, such as diatomaceous earth powder. It is desirable that the mixture of powdered activated carbon and powdered diatomaceous earth has its moisture content sufficiently reduced. The moisture content is preferably 80% or less, and more preferably 50% or less.

[0056] The activated carbon regeneration system according to the above embodiment can regenerate powdered activated carbon with an average particle size of 1 to 100 μm, but it can also be applied to the regeneration of crushed or pelletized granular activated carbon with a particle size of 100 μm or more (100 μm to 10 mm). This enables the conversion of various types of spent activated carbon regeneration to non-fossil energy, regardless of particle size, and allows for a significant reduction in CO2 emissions.

[0057] In the above embodiment, the activated carbon regeneration system was described as having a configuration in which a plate 3 on which powdered activated carbon 1 is placed is moved back and forth by a belt conveyor or the like within a heat treatment box 6 to suppress uneven heating. However, the plate 3 may also be rotated by a turntable.

[0058] The adsorbent to be recycled is not limited to carbon-based adsorbents including activated carbon or activated carbon fiber materials; zeolite, silica gel, alumina, etc., may also be used. [Examples]

[0059] The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples.

[0060] Reference example 1 As a sample of used adsorbent material, a mixture of powdered activated carbon (average particle size 37 μm) after adsorbing organic matter and diatomaceous earth powder (average particle size 24 μm) after filtration treatment, in a weight ratio of 9:1 (moisture content 40%), was prepared. The iodine adsorption performance of this sample before regeneration was 170 mg / g. A rectangular frame (external dimensions 100 mm x 100 mm x 20 mm, width 10 mm) was placed on a quartz plate (130 mm x 130 mm x 10 mm), and 50.31 g of the sample was spread evenly within the frame and placed on a turntable inside a microwave irradiation box (400 mm x 400 mm x 400 mm).

[0061] After purging the microwave irradiation box with nitrogen at a flow rate of 10 L / min for 5 minutes, microwave heating and regeneration were started. Microwaves were irradiated while the turntable rotated at 7 rpm. The blower flow rate for removing the desorption gas from the system was 4.5 m³. 3 The measurement was performed in minutes. The microwave irradiation energy was changed sequentially as follows: 1000W for 180 seconds, 500W for 660 seconds, 700W for 180 seconds, 900W for 300 seconds, and 1000W for 180 seconds.

[0062] At the blower outlet that discharges gas from the microwave irradiation box, the smell of water vapor and desorbed components was detected when the temperature was raised to 100°C. When the temperature was raised to 600°C, white smoke accompanied by a burning smell was emitted from the desorbed gas. The temperature was then maintained until the white smoke subsided, followed by a gradual disappearance of the burning smell, and the test was terminated when the odor had completely subsided. In the initial stages when the white smoke began to appear, it is thought that not only was the vaporization of the adsorbed material occurring, but the carbonization of the desorbed components had also begun. Subsequently, when the odor disappeared, it is thought that almost all of the adsorbed material had been desorbed from the used activated carbon and diatomaceous earth.

[0063] The sample was collected after heating and regeneration, and its weight and iodine adsorption performance were measured. The measurement results are shown in Table 1. It was confirmed that the iodine adsorption performance recovered to 580 mg / g.

[0064] Reference example 2 Except for the fact that 70.01g of the sample was packed into a frame and the microwave irradiation energy was changed sequentially to 1000W for 780 seconds, 1200W for 120 seconds, and 1400W for 900 seconds, everything else was the same. reference In the same manner as in Example 1, reference The sample from Example 2 was regenerated by heating. The measurement results are shown in Table 1. It was confirmed that the iodine adsorption performance recovered to 580 mg / g.

[0065] Reference example 3 A square frame (external dimensions 200mm x 200mm x 20mm, width 10mm) was placed on a 380mm x 380mm x 2mm stainless steel plate. 1205g of sample was packed inside the frame, and to avoid localized heating, the sample was positioned inward in a circular shape around 30mm on each side of the corners. The stainless steel plate with the sample was fixed to the center of the bottom of a belt-conveyor type microwave irradiation box (700mm long, 1500mm wide, 1200mm high). To ensure even microwave irradiation, four propellers (70mm x 150mm) were installed at a 45-degree angle at two locations on the top and rotated at 7rpm. The blower flow rate for removing desorption gas was 7.5m³. 3 The test duration was set to / min. The microwave irradiation energy was varied as follows: 2000W for 1800 seconds, 1000W for 420 seconds, 2000W for 300 seconds, and 2500W for 780 seconds. The test was terminated when the exhaust gas odor had completely disappeared.

[0066] The sample was collected after heating and regeneration, and its weight and iodine adsorption performance were measured. The measurement results are shown in Table 1. It was confirmed that the iodine adsorption performance recovered to 530 mg / g.

[0067] Reference example 4 All other than spreading 1200g of the sample inside the frame, and moving the sample inward in a circular shape around 30mm square at the four corners to avoid localized heating, and varying the microwave irradiation energy to 2000W for 1740 seconds, 1000W for 420 seconds, 3500W for 240 seconds, and 4500W for 900 seconds, everything else was the same. reference In the same manner as in Example 3, reference The sample from Example 4 was regenerated by heating. The measurement results are shown in Table 1. It was confirmed that the iodine adsorption performance recovered to 600 mg / g.

[0068] Reference example 5 reference The powdered activated carbon contained in the sample of Example 1 adsorbed the same organic matter. powder Activated carbon (average particle size 37 μm, water content 10%, iodine adsorption capacity before regeneration 790 mg / g) was used as the sample, 50.73 g was spread in a frame, and the microwave irradiation energy was varied to 1000 W for 150 seconds and 500 W for 900 seconds. reference In the same manner as in Example 1, reference The heating regeneration process described in Example 5 was performed.

[0069] The sample was collected after heating and regeneration, and its weight and iodine adsorption performance were measured. The measurement results are shown in Table 1. It was confirmed that the iodine adsorption performance recovered to 900 mg / g.

[0070] Reference example 6 Except for using a new powdered activated carbon sample (average particle size 34 μm), all other aspects were the same. reference In the same manner as in Example 1, reference Microwave heating was performed as described in Example 6. The heated sample was collected, and its weight and iodine adsorption performance were measured. The measurement results are shown in Table 1. The iodine adsorption performance improved from 1000 mg / g for wood and charcoal to 1070 mg / g after heating. This is thought to be due to the further development of micropores by microwave heating.

[0071] Comparative Example 1 A cylindrical rotating drum (φ200mm, height 100mm), simulating a rotary kiln heating furnace, is placed inside a microwave irradiation box (400mm x 400mm x 400mm) at an angle of 45°. degree It was installed inside this rotating drum. reference 390.49g of the same sample as in Example 1 was placed in the microwave irradiation box. Nitrogen purging was performed in the microwave irradiation box at a flow rate of 10 L / min for 5 minutes, and then microwave heating and regeneration was started while rotating the drum at a rotation speed of 3 rpm.

[0072] The microwave irradiation energy was sequentially changed to 2000W for 660 seconds, 1000W for 60 seconds, and 1200W for 210 seconds, maintaining the temperature inside the rotating drum at approximately 500-600°C.

[0073] In this regeneration test, powder was scattered along with the desorption gas from the used activated carbon and diatomaceous earth mixture, causing the powdered carbon to adhere to the microwave irradiation box and undergo scattering deposition. The sample was collected after heating and regeneration, and its weight and iodine adsorption performance were measured. The measurement results are shown in Table 2. Although the iodine adsorption performance recovered to 530 mg / g, it was confirmed that the influence of the fine powder scattered along with the desorption gas from the rotating drum makes it impractical to implement this in a real device.

[0074] Comparative Example 2 The sample consisted of 40g of a mixture of diatomaceous earth used for pre-coat filtration and the material to be filtered (organic substance), and was irradiated with microwaves at a constant energy of 1000W. reference A microwave heating test was performed on Comparative Example 2 in the same manner as in Example 1. The test was stopped because the sample ignited 470 seconds after the start of irradiation.

[0076] [Table 1]

[0077] [Table 2]

[0078] It should be noted that the present invention is not limited to the embodiments described above, and the components can be modified and implemented in practice without departing from the spirit of the invention. Furthermore, various inventions can be formed by appropriately combining the multiple components disclosed in the above embodiments. For example, some components may be deleted from all the components shown in the embodiments. Moreover, components from different embodiments may be appropriately combined. [Explanation of Symbols]

[0079] 1 activated carbon 2 Hopper 3 boards 4. Conveying section 5. Leveling plate 6 Heat treatment box 7. Microwave generator 8 Exhaust pipes 9 propellers 10 Infrared Cameras 11. Microwave leakage prevention shutter 20 Control device

Claims

1. The process involves placing activated carbon with an average particle size of 1 to 100 μm on a flat plate and introducing this plate into a heat treatment box. After purging the heat treatment box with nitrogen, microwave irradiation is started and the microwave irradiation is continued until the initial moisture in the activated carbon evaporates and the temperature stabilizes at around 100°C, which constitutes a drying process. Once the temperature rises above 100°C, a firing desorption process is performed to maintain the heating temperature at 200-1400°C using microwave irradiation. Subsequently, a reactivation step is performed in which the heating temperature using microwaves is increased from that of the calcination desorption step, and the microwave irradiation is carried out until the components of the adsorbed substance in the exhaust gas fall below a predetermined value. An activated carbon regeneration system for regenerating activated carbon, A hopper that supplies activated carbon with an average particle size of 1 to 100 μm onto a flat plate, A leveling plate for adjusting the height of the activated carbon on the aforementioned flat plate to a constant level, The aforementioned heat treatment box, A microwave generator that irradiates microwaves into the heat treatment box, An analytical means for analyzing exhaust gas from the heat treatment box, A temperature detection means for detecting the temperature of the activated carbon in the heat treatment box, A control means for controlling the microwave generator based on the analysis results of the analysis means and the temperature detected by the temperature detection means, wherein the control means raises the temperature until the detected temperature is 100°C or higher, then maintains the heating temperature by microwave irradiation at 200 to 1400°C, and then, when the components of the adsorbed substance in the exhaust gas fall below a predetermined value, raises the heating temperature by microwave irradiation above the level of the calcination desorption process, and continues the microwave irradiation until the components of the adsorbed substance in the exhaust gas fall below a predetermined value. A regeneration system for activated carbon equipped with [a specific feature].

2. The activated carbon regeneration system according to claim 1, further comprising a transport unit for transporting the flat plate on which the activated carbon is placed into a heat treatment box.

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