Continuous heat treatment apparatus for activated carbon and method for regenerating activated carbon

Abstract

The present invention provides a continuous heat treatment apparatus for activated carbon that decomposes organofluorine compounds attached to activated carbon, thereby continuously regenerating the activated carbon. [Solution] A continuous heat treatment apparatus for heat-treating activated carbon to which an organofluorine compound is attached, the heat treatment apparatus comprising: a transfer device for transferring activated carbon to which an organofluorine compound is attached; and a microwave heating container having a microwave irradiation unit, wherein the microwave heating container has an inlet for transferring the activated carbon from outside the container to inside the container by the transfer device; and an outlet for transferring the activated carbon from inside the container to outside the container after microwave irradiation by the transfer device, and the microwave irradiation unit inside the microwave heating container is provided so as to be able to irradiate the activated carbon transferred into the container by the transfer device with microwaves.

Description

Technical Field

[0001] The present disclosure relates to a continuous heat treatment apparatus for activated carbon and a method for regenerating activated carbon.

Background Art

[0002] Activated carbon is used for adsorption treatment in fields such as wastewater treatment, exhaust gas treatment, deodorization treatment, pure water treatment, or water treatment. The activated carbon used for adsorption treatment has a reduced adsorption capacity. In order to reuse activated carbon, it is necessary to restore its adsorption capacity. In view of such a situation, a method for regenerating activated carbon, which regenerates activated carbon from used activated carbon, has been studied (see, for example, Patent Documents 1 to 4).

[0003] Activated carbon used for adsorption treatment such as an aqueous solution containing an organic fluorine compound is usually discarded as industrial waste without performing a regeneration treatment. When a regeneration treatment is performed on used activated carbon, the organic fluorine compound attached to the activated carbon may migrate into the exhaust gas without being decomposed and diffuse into the atmosphere. In addition, some organic fluorine compounds are classified as hardly decomposable substances. Such organic fluorine compounds may exist in water, soil, or the atmospheric environment without being decomposed for many years.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0005] In conventional methods for regenerating adsorbents from used adsorbents that have adsorbed ordinary organic compounds, the used activated carbon undergoes heat treatment in a regeneration furnace. For example, there are known multi-stage regeneration furnaces suitable for large furnaces that use an external heating method with heavy oil or gas, rotary kiln regeneration furnaces suitable for medium-sized furnaces, and direct current superheating regeneration furnaces suitable for small furnaces that are heated by the application of electrodes.

[0006] Most organic compounds decompose at the operating temperature of the regeneration furnace described above. However, organofluorine compounds may not decompose sufficiently at this temperature. As a result, there is a concern that a large amount of organofluorine compounds detached from spent activated carbon will be contained in the exhaust gas discharged from the regeneration furnace, and that these organofluorine compounds will diffuse into the atmosphere. Due to this concern, spent activated carbon on which organofluorine compounds have been adsorbed is often disposed of without undergoing regeneration treatment.

[0007] The present disclosure aims to provide a continuous heat treatment apparatus for activated carbon that continuously regenerates activated carbon by decomposing organofluorine compounds attached to activated carbon. [Means for solving the problem]

[0008] One embodiment of a continuous heat treatment apparatus for activated carbon according to the present disclosure comprises a transfer device for transferring activated carbon to which an organofluorine compound is attached, and a microwave heating vessel having a microwave irradiation section, wherein the microwave heating vessel has an inlet for transferring the activated carbon from outside the vessel to inside the vessel by the transfer device, and an outlet for transferring the activated carbon from inside the vessel to outside the vessel after microwave irradiation by the transfer device, and the microwave irradiation section inside the microwave heating vessel is provided so as to be able to irradiate the activated carbon transferred into the vessel by the transfer device with microwaves. [Effects of the Invention]

[0009] According to this disclosure, it is possible to provide a continuous heat treatment apparatus for activated carbon that decomposes organofluorine compounds attached to activated carbon and continuously regenerates the activated carbon. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a schematic diagram showing one embodiment of the heat treatment apparatus of the present disclosure. [Figure 2] Figure 2 is a schematic diagram showing one embodiment of the heat treatment apparatus of the present disclosure. [Figure 3] Figure 3 is a schematic diagram showing one embodiment of the heat treatment apparatus of the present disclosure. [Figure 4] Figure 4 is a schematic diagram showing one embodiment of the heat treatment apparatus of the present disclosure. [Figure 5] Figure 5 is a schematic diagram showing one embodiment of the heat treatment apparatus of the present disclosure. [Figure 6] Figure 6 is a schematic diagram showing one embodiment of the heat treatment apparatus of the present disclosure. [Figure 7] Figure 7 is a schematic diagram showing one embodiment of the heat treatment apparatus of the present disclosure. [Modes for carrying out the invention]

[0011] In this specification, the numerical range N1 to N2 means N1 or greater and N2 or less. In this specification, if the units of the numbers before and after the "~" indicating a numerical range are the same, the unit of the number before the "~" may be omitted.

[0012] [Continuous heat treatment device for activated carbon] The continuous heat treatment apparatus for activated carbon described herein (hereinafter also referred to as "the apparatus") is an apparatus for continuously heat-treating activated carbon to which organofluorine compounds are attached. The apparatus is an apparatus for heat-treating the above-mentioned activated carbon in a continuous manner, rather than in a batch manner. This device A transfer device for transporting activated carbon to which organic fluorine compounds are attached, A heating vessel having a microwave irradiation section (hereinafter also referred to as a "microwave heating vessel"), It is equipped with.

[0013] By using this device, while transferring the activated carbon by a transfer device, irradiating the activated carbon with microwaves enables continuous regeneration of the activated carbon. Compared with a batch-type regeneration device, this continuous-type device can regenerate a large amount of activated carbon. In this specification, "regeneration of activated carbon" means at least partially restoring the original adsorption capacity of activated carbon or enhancing the adsorption capacity of activated carbon by removing the organic fluorine compounds adhering to the activated carbon.

[0014] In this specification, "removing an object from activated carbon" means removing at least a part of the object from the activated carbon. "Removal" includes, in addition to the decomposition of the object, the desorption of the object from the activated carbon. "Desorption" means that the object separates from the activated carbon by volatilization or the like. The object is, for example, an organic fluorine compound.

[0015] Organic fluorine compounds are attached to the activated carbon to be heat-treated in this device by adsorption or the like. The activated carbon may be one kind or two or more kinds. The organic fluorine compounds may be one kind or two or more kinds. The activated carbon to be heat-treated in this device is, for example, used activated carbon.

[0016] This device includes a heat treatment container in one embodiment. The microwave heating container is preferably housed in the heat treatment container. At least one container selected from the group consisting of a steam heating container and an inert gas heating container, which are provided as desired and will be described later, is also preferably housed in the heat treatment container.

[0017] This device includes a transfer device for transferring the activated carbon. The transfer device transfers the activated carbon so that the activated carbon passes through the microwave heating container. Examples of the transfer device include conveyors such as belt conveyors, mesh belts, and rollers.

[0018] The activated carbon described above is placed, for example, on a transfer platform. The activated carbon is placed, for example, on multiple transfer platforms. The transfer platforms are placed on a transfer device and transported. Examples of the shapes of the transfer platforms include flat plates and concave shapes. The material of the transfer table and the material of the transfer device in contact with the transfer table are not particularly limited as long as they can withstand microwave irradiation and high temperatures, but examples include stainless steel (SUS; specifically, SUS410, SUS430), highly heat-resistant materials (specifically, alumina, zirconia, titania, high-temperature resistant SUS such as SUS304, SUS310, and SUS316), and SUS coated with such highly heat-resistant materials.

[0019] The transfer speed of the activated carbon in the transfer device is not particularly limited and can be set appropriately according to the heating temperature and heating time of the activated carbon, as well as the amount of activated carbon supplied. The transfer speed is preferably 0.3 to 10 m / min, more preferably 0.5 to 10 m / min, and even more preferably 1 to 5 m / min.

[0020] Considering the penetration depth and attenuation of microwaves into the activated carbon, it is preferable that the aggregate of activated carbon irradiated with microwaves be in a layered structure. The activated carbon is placed on a transfer stand, for example, as a layer of activated carbon (activated carbon layer). The thickness of the activated carbon layer irradiated with microwaves is preferably 1 to 100 mm, more preferably 2 to 80 mm, even more preferably 3 to 50 mm, and particularly preferably 5 to 30 mm.

[0021] Examples of activated carbon include powdered activated carbon and granular activated carbon. This device can be used for the regeneration of either powdered or granular activated carbon. Granular activated carbon has a larger particle size than powdered activated carbon. Specifically, examples of activated carbon include mineral-based activated carbon such as coal-based activated carbon and petroleum-based activated carbon; and plant-based activated carbon such as wood-based activated carbon and coconut shell activated carbon.

[0022] Examples of organofluorine compounds include perfluoroalkyl compounds having a perfluoroalkyl group and polyfluoroalkyl compounds having a polyfluoroalkyl group.

[0023] Examples of perfluoroalkyl compounds include perfluoroalkyl sulfonic acid and its derivatives, perfluoroalkyl carboxylic acid and its derivatives, perfluoroalkyl ethers such as perfluoro(2-butyl-tetrahydrofuran), perfluoroalkanes, perfluoroalkyl sulfides, perfluoroalkyl iodides, perfluoroalkylamines such as perfluorotributylamine, perfluoroalkyl phosphate esters, perfluoroalkylsilane compounds, and salts thereof.

[0024] Examples of polyfluoroalkyl compounds include polyfluoroalkyl sulfonic acids and their derivatives, polyfluoroalkyl carboxylic acids and their derivatives, polyfluoroalkyl ethers, polyfluoroalkanes, polyfluoroalkyl sulfides, polyfluoroalkyl iodides, polyfluoroalkylamines, polyfluoroalkyl phosphate esters, polyfluoroalkylsilane compounds, and salts thereof.

[0025] Examples of organofluorine compounds include perfluorobutanesulfonic acid, perfluoro(2-ethoxyethane)sulfonic acid, perfluoropentanesulfonic acid, perfluoro-1,3-propanedisulfonic acid, 1H,1H,2H,2H-perfluorohexanesulfonic acid, perfluorohexanesulfonic acid (PFHxS), perfluoroheptanesulfonic acid, 1H,1H,2H,2H-perfluorooctanesulfonic acid, 9-chlorohexadecafluoro-3-oxanonan-1-sulfonic acid, and perfluoroocta Perfluorooctanesulfonic acid (PFOS), perfluorooctanesulfonic acid fluoride, perfluorooctanesulfonic acid amide, perfluorononanesulfonic acid, 11-chloroicosafluoro-3-oxaundecane-1-sulfonic acid, 1H,1H,2H,2H-perfluorodecanesulfonic acid, perfluorodecanesulfonic acid, N-ethylperfluorooctanesulfonamide acetate, N-methylperfluorooctanesulfonamide acetate, perfluoroundecanesulfonic acid, perfluorododecanesulfonic acid, perfluoro Tridecanesulfonic acid, perfluoropropionic acid, perfluorobutanoic acid, perfluoro-3-methoxypropanoic acid, nonafluoro-3,6-dioxaheptanoic acid, perfluoro-4-methoxybutanoic acid, perfluoropentanoic acid, hexafluoropropylene oxide dimer acid, perfluorohexanoic acid, 4,8-dioxa-3H-perfluorononanoic acid, perfluoroheptanoic acid, perfluorooctanoic acid (PFOA), perfluorononanoic acid, perfluorodecanoic acid, perfluoroundecanoic acid, perfluoro Examples include rhododecanoic acid, perfluorotridecanoic acid, perfluorotetradecanoic acid, perfluorohexadecanoic acid, perfluorobutane, perfluoropentane, perfluorohexane, perfluorooctane, perfluorodecane, perfluorododecane, perfluorotetradecane, perfluorohexadecane, perfluorobutyl ethyl sulfide, perfluorohexyl ethyl sulfide, perfluorooctyl ethyl sulfide, perfluorooctyl iodide, and perfluorodecyl iodide.

[0026] Among organofluorine compounds, at least one selected from the group consisting of perfluorooctanesulfonic acid (PFOS), perfluorohexanesulfonic acid (PFHxS), and perfluorooctanoic acid (PFOA) is preferred.

[0027] Examples of the above derivatives include esters, amides, and halides. Examples of the above salts include alkali metal salts such as lithium salts, sodium salts, and potassium salts; amine salts such as alkanolamine salts such as monoethanolamine salts, diethanolamine salts, and triethanolamine salts; and ammonium salts.

[0028] The number of carbon atoms in the organofluorine compound is preferably 20 or less, more preferably 18 or less, even more preferably 16 or less, and particularly preferably 14 or less. The boiling point of organofluorine compounds at 1 atmosphere is preferably 120 to 800°C, more preferably 120 to 500°C, even more preferably 120 to 400°C, and particularly preferably 120 to 300°C.

[0029] This device is equipped with a μ-wave heating vessel. The microwave heating vessel is not particularly limited as long as it is a vessel that can withstand microwave irradiation. Examples of materials for the microwave heating vessel include stainless steel (SUS; specifically, SUS410, SUS430), highly heat-resistant materials (specifically, alumina, zirconia, titania, high-temperature resistant SUS such as SUS304, SUS310, and SUS316), and SUS coated with such highly heat-resistant materials.

[0030] Since stainless steel (SUS) fundamentally reflects microwaves, the temperature of a SUS container hardly rises due to microwave irradiation itself; the temperature rise is mainly due to heat transfer from the activated carbon. Therefore, under microwave irradiation conditions, the activated carbon can be heated without the temperature of the SUS reaching its melting point.

[0031] The microwave irradiation unit is provided inside the μ-wave heating container so as to enable the irradiation of the activated carbon, which has been transferred into the container by the transfer device, with microwaves. For example, the microwave irradiation unit is provided inside the container so as to enable the irradiation of the activated carbon while it is being transferred inside the μ-wave heating container by the transfer device with microwaves. The location of the microwave irradiation unit inside the μ-wave heating container is not particularly limited. The microwave irradiation unit may be provided on the ceiling surface of the μ-wave heating container or on the side wall of the μ-wave heating container. From the viewpoint of increasing the efficiency of microwave irradiation to the activated carbon, the μ-wave heating container may be equipped with a metal plate (e.g., a propeller) that reflects microwaves.

[0032] In conventional regeneration furnaces, the used activated carbon inside the furnace is heated by heat transfer. However, conventional regeneration methods tend to have difficulty operating at high temperatures due to the heat resistance of the materials that make up the furnace. Therefore, conventional regeneration furnaces tend to have difficulty adequately decomposing the organic fluorine compounds attached to the activated carbon.

[0033] On the other hand, in this device, the activated carbon is heated to a high temperature, for example, by irradiating it with microwaves. Microwave heating is a so-called internal heating method in which microwaves directly act on the activated carbon and directly heat the activated carbon itself, thereby heating the organofluorine compounds attached to the activated carbon. For this reason, the temperature around the activated carbon does not rise in the same way as the temperature of the activated carbon rises. Only the components in contact with the activated carbon are indirectly heated by heat transfer due to the rising temperature of the activated carbon, and the microwave heating container itself is hardly heated. In other words, microwave heating can solve the heat resistance limitations of the material of the activated carbon heating container. Furthermore, unlike conventional activated carbon regeneration furnaces that use heat transfer methods, the microwave heating device can directly raise the temperature of the activated carbon using an internal heating method, so the microwave heating device itself is hardly heated, resulting in excellent thermal efficiency. For this reason, the regeneration heating energy can be kept low, and the amount of CO2 emitted can be reduced.

[0034] This device allows for the complete decomposition of organofluorine compounds attached to activated carbon by adjusting the heating temperature using microwave irradiation. While some desorption of organofluorine compounds from the activated carbon may occur along with the decomposition of organofluorine compounds on the activated carbon, it is preferable to perform microwave irradiation under conditions where the decomposition of organofluorine compounds proceeds primarily, from the viewpoint of suppressing the gasification of organofluorine compounds.

[0035] Therefore, by applying this device to activated carbon that has adsorbed organic fluorine compounds such as so-called PFAS (for example, used activated carbon) and regenerating the activated carbon, used activated carbon can be reused as activated carbon without disposal methods such as landfill or incineration, and without diffusing and releasing large amounts of organic fluorine compounds into the atmosphere.

[0036] When organic carbon substances other than organofluorine compounds are adsorbed on activated carbon, the adsorption amounts of the two are usually different. Since the adsorption amount of organofluorine compounds is usually small, the organofluorine compounds tend to decompose or desorb before the organic carbon substances. For this reason, microwaves are used to decompose or desorb organofluorine compounds, but it is not always necessary to decompose or desorb the organic carbon substances.

[0037] Microwaves are generated, for example, by a microwave oscillator. The microwave irradiation unit may include a microwave oscillator. Alternatively, the apparatus may include a microwave oscillator located outside the μ-wave heating container and a waveguide for introducing microwaves into the μ-wave heating container (microwave irradiation unit). Examples of microwave oscillators include magnetrons, klystrons, and Gunn diodes, with magnetrons being preferred among these.

[0038] The microwave frequency is preferably 0.3 to 30 GHz, more preferably 0.5 to 28 GHz, even more preferably 1 to 26 GHz, even more preferably 1 to 15 GHz, and particularly preferably 1 to 8 GHz. The microwave output is preferably 10 W to 10,000 kW, more preferably 50 W to 8,000 kW, and even more preferably 100 W to 6,000 kW.

[0039] The temperature of the activated carbon irradiated with microwaves (hereinafter also referred to as the "heating temperature of the activated carbon") is, for example, above 800°C, preferably above 820°C, more preferably above 850°C, even more preferably above 900°C, even more preferably above 950°C, particularly preferably above 980°C, preferably below 1500°C, more preferably below 1300°C, even more preferably below 1200°C, for example, above 800°C and below 1500°C, preferably between 820 and 1500°C, more preferably between 850 and 1300°C, and even more preferably between 900 and 1200°C. At such temperatures, organic fluorine compounds attached to the activated carbon tend to be sufficiently decomposed.

[0040] In the μ-wave heating vessel, the temperature of the activated carbon can be maintained at over 800°C (preferably the heating temperature of the activated carbon described above) for 1 second or more, ensuring the residence time necessary for the decomposition of the organofluorine compound. The time for maintaining the temperature of the activated carbon above 800°C is, for example, 1 second or more, preferably 1 second to 10 minutes, more preferably 1 second to 5 minutes, and even more preferably 1 second to 3 minutes, and may be, for example, 2 seconds or more, 5 seconds or more, 10 seconds or more, 20 seconds or more, or 30 seconds or more. Under these conditions, the organofluorine compound can be sufficiently decomposed.

[0041] The μ-wave heating vessel may further include a temperature sensor for measuring the temperature of the activated carbon. An example of a temperature sensor is an infrared thermographic camera.

[0042] In a microwave heating vessel, the activated carbon may be heated by microwave irradiation, starting from a temperature of 800°C or lower (hereinafter also referred to as the "starting temperature") and rising to over 800°C (preferably the heating temperature of the activated carbon as described above). In one embodiment, the starting temperature is preferably 100°C or lower, more preferably 0 to 80°C, even more preferably 3 to 60°C, even more preferably 5 to 40°C, and particularly preferably room temperature. The heating rate of the activated carbon by microwave irradiation is preferably 20°C / second or higher, more preferably 30°C / second or higher, even more preferably 40°C / second or higher, and particularly preferably 45 to 100°C / second. Such a heating rate can be achieved by microwave irradiation. By heating the activated carbon at such a heating rate, the decomposition of the organofluorine compound can be promoted well while suppressing the desorption and gasification of the organofluorine compound from the activated carbon, and in some cases, decomposition can proceed to HF.

[0043] The microwave heating vessel has an inlet for transferring the activated carbon from outside the vessel to inside the vessel by a transfer device, and an outlet for transferring the activated carbon, after microwave irradiation, from inside the vessel to outside the vessel by a transfer device. The activated carbon is brought into the microwave heating vessel by the transfer device through the inlet and is brought out of the microwave heating vessel by the outlet. Inside the microwave heating vessel, the activated carbon on the transfer device is irradiated with microwaves.

[0044] The inlet and outlet of the microwave heating vessel are openings. If the openings are large, microwaves may leak out of the microwave heating vessel, reducing the microwave irradiation efficiency and the heating efficiency of the activated carbon. For this reason, it is preferable that the openings be small. With such a vessel configuration, microwaves generated or introduced in the microwave irradiation section can be efficiently contained within the vessel, and the activated carbon can be efficiently heated.

[0045] The size of the vertical gap between the activated carbon or its transfer stand passing through the inlet of the μ-wave heating vessel and the upper boundary portion of the μ-wave heating vessel that is in contact with the opening of the inlet (the distance between the activated carbon or transfer stand and the upper boundary portion) is preferably 100 mm or less, more preferably 5 to 50 mm, even more preferably 5 to 30 mm, and particularly preferably 5 to 10 mm, from the viewpoint of suppressing microwave leakage. The size of the vertical gap between the activated carbon or its transfer stand passing through the outlet of the μ-wave heating vessel and the upper boundary portion of the μ-wave heating vessel that is in contact with the outlet opening (the distance between the activated carbon or transfer stand and the upper boundary portion) is preferably 100 mm or less, more preferably 5 to 50 mm, even more preferably 5 to 30 mm, and particularly preferably 5 to 10 mm, from the viewpoint of suppressing microwave leakage. The size of the above gap refers to the smaller of the size of the gap between the activated carbon and the upper boundary portion of the μ-wave heating container, and the size of the gap between the transfer platform and the upper boundary portion of the μ-wave heating container.

[0046] A μ-wave heating vessel may be connected to a gas discharge line through which the gas discharged from the vessel flows. The gas discharge line carries the gas discharged from the μ-wave heating vessel. A μ-wave heating vessel usually has a gas outlet. The gas discharge line is connected to the gas outlet of the μ-wave heating vessel. A gas containing compounds derived from the above-mentioned organofluorine compounds is discharged from the gas outlet. This gas also includes at least one gas component selected from the group consisting of water vapor and inert gases, if such a gas component is supplied into the μ-wave heating vessel. A blower for drawing in the above-mentioned gas may be provided on the gas discharge line.

[0047] The oxygen gas concentration in the atmosphere of the μ-wave heating vessel is preferably 10% by volume or less, more preferably 6% by volume or less, even more preferably 4% by volume or less, and particularly preferably 2% by volume or less.

[0048] In one embodiment, this device A steam supply device that supplies steam into a μ-wave heating vessel, and In the above-mentioned activated carbon transfer path, downstream of the μ-wave heating vessel, there is a heating vessel for heating the activated carbon with steam (hereinafter also referred to as the "steam heating vessel"), It may further include at least one selected from the group consisting of the following: In this specification, steam includes heated steam (hereinafter also referred to as "superheated steam"). It is preferable that the steam is superheated steam. The preferred temperature for superheated steam will be described later.

[0049] A steam heating vessel may be connected to a steam supply device that supplies steam into the heating vessel. When the device includes a steam heating vessel, the steam heating vessel is positioned so that the activated carbon passes through the μ-wave heating vessel before passing through the steam heating vessel.

[0050] The steam heating vessel has an inlet for transferring the activated carbon from outside the vessel to inside the vessel by a transfer device, and an outlet for transferring the activated carbon from inside the vessel to outside the vessel by a transfer device.

[0051] The apparatus may include a steam supply device that supplies steam into the microwave heating vessel. In this case, the activated carbon can be heated by heated steam along with microwave irradiation. Contact between the activated carbon and heated steam may be performed along with microwave irradiation of the activated carbon; for example, the activated carbon may be irradiated with microwaves in an atmosphere containing heated steam. Trace amounts of carbides may remain on the activated carbon after microwave irradiation (e.g., inside the pores). These carbides can be gasified and removed from the activated carbon by a water gasification reaction by contacting the activated carbon with heated steam. In gasification, gases such as hydrogen and carbon monoxide may be generated. Furthermore, heated steam can also function as a heat source for removing organofluorine compounds from the activated carbon.

[0052] This apparatus may include a steam heating vessel downstream of the microwave heating vessel in the activated carbon transfer path. The activated carbon after microwave irradiation may be brought into contact with heated steam. The carbides can be gasified and removed from the activated carbon by the aqueous gasification reaction caused by contact between the activated carbon and heated steam.

[0053] The temperature of the heated steam brought into contact with the activated carbon is preferably 600 to 1200°C, more preferably 650 to 1100°C, even more preferably 700 to 1000°C, and particularly preferably 750 to 900°C, from the viewpoint of enabling the water gasification reaction to proceed smoothly and suppressing the deterioration of the activated carbon itself.

[0054] The steam supply system includes, for example, a steam generator and a steam supply line connecting the generator to a μ-wave heating vessel or a steam heating vessel. In this case, the μ-wave heating vessel or steam heating vessel is equipped with a steam inlet. The steam supply line is connected to the steam inlet.

[0055] This device may include a heating section capable of adjusting the temperature of the steam at one or more locations selected from the group consisting of the steam generator, the steam supply line, the μ-wave heating vessel, and the steam heating vessel.

[0056] A μ-wave heating vessel or a steam heating vessel may be equipped with the heating section described above. This heating section heats the steam introduced into the μ-wave heating vessel or steam heating vessel. When the steam is heated in the μ-wave heating vessel or steam heating vessel and brought into contact with the activated carbon, it is not necessary to preheat the steam in the steam supply line, nor is it necessary to provide a heating section for heating the steam on the steam supply line.

[0057] The steam generator may also include the heating section described above. The heating unit described above may be provided on the steam supply line. This heating unit heats the steam flowing through the steam supply line. The heating unit can be installed anywhere on the steam supply line as long as it can heat the steam, but it is preferable to install it in a location close to the μ-wave heating container or steam heating container in order to minimize heat loss from the steam.

[0058] Examples of heating devices for heating water vapor or the inert gas described later include direct heating devices such as cartridge heaters, flange heaters, infrared heaters, tape heaters, and ceramic heaters; and indirect heating devices such as induction heating devices, dielectric heating devices, and microwave heating devices. This device may further include a temperature sensor for measuring the temperature of the water vapor.

[0059] In one embodiment, this device An inert gas supply device that supplies an inert gas into at least one container selected from the group consisting of a μ-wave heating container, a steam heating container, and a heat treatment container, and In the above-mentioned activated carbon transfer path, downstream of the μ-wave heating vessel, there is a heating vessel that heats the activated carbon with an inert gas (hereinafter also referred to as the "inert gas heating vessel"), It may further include at least one selected from the group consisting of the following:

[0060] Examples of inert gases include nitrogen and argon. An inert gas heating container may be connected to an inert gas supply device that supplies inert gas into the heating container.

[0061] If the apparatus includes a steam heating vessel and an inert gas heating vessel, it is preferable that the activated carbon transfer path is arranged in the order of microwave heating vessel, steam heating vessel, and inert gas heating vessel from upstream to downstream. By adjusting the temperature of the inert gas in the inert gas heating vessel, the rapid temperature drop and oxidation of the activated carbon, which has been heated to a high temperature by microwave irradiation or contact with heated steam, may be suppressed. From this viewpoint, it is preferable that the temperature of the inert gas in the inert gas heating vessel is the same as or lower than the temperature of the heated steam in the steam heating vessel.

[0062] The inert gas heated container has an inlet for transferring the activated carbon from outside the container to inside the container by a transfer device, and an outlet for transferring the activated carbon from inside the container to outside the container by a transfer device.

[0063] The apparatus may include an inert gas supply device that supplies an inert gas into the microwave heating container. It is preferable to irradiate the activated carbon with microwaves under an inert gas atmosphere. In this case, the temperature of the inert gas in the microwave heating container is preferably 0 to 100°C, more preferably 5 to 75°C, and even more preferably 10 to 50°C, which is, for example, around room temperature, from the viewpoint of energy saving and the like. If a steam heating container is provided, the apparatus may also be equipped with an inert gas supply device that supplies an inert gas into the steam heating container. It is preferable to bring the heated steam into contact with the activated carbon under an inert gas atmosphere. With this configuration, oxidative degradation of the activated carbon at high temperatures and the generation of carbon monoxide or carbon dioxide by the activated carbon combining with oxygen can be suppressed. The temperature of the inert gas when bringing the heated steam into contact with the activated carbon under an inert gas atmosphere is preferably 100 to 800°C, more preferably 200 to 800°C, and even more preferably 300 to 800°C, from the viewpoint of suppressing a decrease in the temperature of the heated steam.

[0064] The apparatus may include an inert gas supply device that supplies an inert gas into the heat treatment container. By creating an inert gas atmosphere inside the heat treatment container, oxidative degradation of the activated carbon discharged from the μ-wave heating container, steam heating container, or inert gas heating container can be suppressed. The temperature of the inert gas inside the heat treatment container is preferably 0 to 100°C, more preferably 5 to 75°C, and even more preferably 10 to 50°C, which is, for example, around room temperature.

[0065] For example, the activated carbon may be irradiated with microwaves in a microwave heating vessel under an inert gas atmosphere, a water vapor atmosphere, or a mixed gas atmosphere of an inert gas and water vapor. The water vapor may be heated water vapor. With this configuration, microwave irradiation can be performed in an atmosphere with a low oxygen gas concentration, and therefore the deterioration of the quality of the activated carbon itself can be suppressed.

[0066] The apparatus may include an inert gas heating vessel downstream of the microwave heating vessel in the activated carbon transfer path. By heating the activated carbon in an inert gas atmosphere after microwave irradiation, the rapid temperature drop of the activated carbon, which has been heated to a high temperature of, for example, more than 800°C by microwave irradiation, can be suppressed, and oxidation of the activated carbon can also be suppressed. The temperature of the inert gas in the inert gas heating vessel is preferably 30 to 800°C, more preferably 40 to 800°C, and even more preferably 50 to 800°C.

[0067] The apparatus for supplying inert gas into the μ-wave heating vessel, the apparatus for supplying inert gas into the steam heating vessel, the apparatus for supplying inert gas into the inert gas heating vessel, and the apparatus for supplying inert gas into the heat treatment vessel may be a single inert gas supply apparatus or separate inert gas supply apparatuses.

[0068] This device may further include a temperature sensor for measuring the temperature of the inert gas.

[0069] The inert gas supply system includes, for example, an inert gas storage device and an inert gas supply line connecting the storage device to at least one selected from the group consisting of a microwave heating vessel, a steam heating vessel, an inert gas heating vessel, and a heat treatment vessel. In this case, the microwave heating vessel, steam heating vessel, inert gas heating vessel, or heat treatment vessel is equipped with an inert gas inlet. The inert gas supply line is connected to the inert gas inlet.

[0070] This apparatus may include a heating unit capable of adjusting the temperature of the inert gas at one or more locations selected from the group consisting of an inert gas storage device, an inert gas supply line, a microwave heating vessel, a steam heating vessel, an inert gas heating vessel, and a heat treatment vessel.

[0071] In an inert gas heating container, instead of heating the activated carbon with heated inert gas, the activated carbon may be heated using the direct heating device or indirect heating device described above. In this case, the inert gas heating container may be supplied with inert gas at approximately room temperature.

[0072] Steam heating vessels, inert gas heating vessels, and heat treatment vessels may be connected to gas discharge lines through which the gas discharged from the vessel flows. Each vessel typically has a gas outlet. The gas discharge line is connected to the gas outlet of each vessel.

[0073] In a μ-wave heating vessel, a steam heating vessel, an inert gas heating vessel, and a heat treatment vessel, the gas inlet, such as steam or an inert gas, is also called the "gas component inlet," and the gas outlet is also called the "gas component outlet." The location of the gas component inlet in each container is not particularly limited. The gas component inlet may be located, for example, above or below the activated carbon on the transfer device in the vertical direction. The gas component inlet may be located, for example, at the top (or apex) or bottom (or base) of each container. The location of the gas component outlet in each container is not particularly limited. The gas component outlet may be located, for example, below or above the activated carbon on the transfer device in the vertical direction. The gas component outlet may be located, for example, at the bottom (or base) or top (or apex) of each container.

[0074] The μ-wave heating vessel may be an upward flow type in which a gas component such as water vapor or an inert gas is introduced from the bottom (or base) of the heating vessel and the gas is removed from the top (or apex), or a downward flow type in which a gas component such as water vapor or an inert gas is introduced from the top (or apex) of the heating vessel and the gas is removed from the bottom (or base).

[0075] The steam supply line and / or inert gas supply line may be equipped with at least one selected from the group consisting of a pressure regulating valve, a flow meter, and a pressure sensor. The pressure regulating valve is a valve that adjusts the supply pressure of the steam or inert gas supplied from the above device to each of the above containers. The flow meter is a device that measures the flow rate of steam or inert gas flowing through the steam supply line or inert gas supply line. The flow meter may be electrically connected to the control device. The control device acquires flow rate information of steam or inert gas based on the measurement value of the flow meter. The pressure sensor is a device that measures the supply pressure of steam or inert gas. The pressure sensor may be electrically connected to the control device. The control device acquires pressure information based on the measurement value of the pressure sensor. Each line is composed of, for example, piping.

[0076] The apparatus, specifically the heat treatment vessel, may have a room temperature region upstream of the μ-wave heating vessel in the activated carbon transfer path. The apparatus, specifically the heat treatment vessel, may have a room temperature region or a cooling region downstream of the μ-wave heating vessel (for example, downstream of the steam heating vessel) in the activated carbon transfer path.

[0077] In the cooling region, the activated carbon is cooled after contact with water vapor (including cooling by heat dissipation). In the cooling region, it is preferable to gradually lower the temperature so that the activated carbon does not become extremely brittle and so that thermal degradation of the transfer platform and transfer device on which the activated carbon is placed is suppressed. The cooling temperature is not particularly limited, but is preferably less than 100°C, more preferably 80°C or less, even more preferably 60°C or less, even more preferably 40°C or less, and particularly preferably 30°C or less, for example, 0°C or higher.

[0078] The apparatus may further include an activated carbon supply device that supplies the activated carbon onto a transfer device before it enters the μ-wave heating vessel. Examples of activated carbon supply devices include a hopper and a screw feeder. This apparatus may further include an activated carbon recovery device for recovering the regenerated activated carbon that has been transferred from the microwave heating vessel.

[0079] In one embodiment, microwave irradiation yields a gas containing compounds derived from organofluorine compounds, such as decomposition products of organofluorine compounds. Preferably, the apparatus further includes a scrubber treatment device for wet scrubbing the gas discharged from the microwave heating vessel. In this case, the gas discharge line connects the microwave heating vessel and the scrubber treatment device. The gas discharge line may also be connected to at least one selected from the group consisting of a steam heating vessel, an inert gas heating vessel, and a heat treatment vessel. The scrubber apparatus removes compounds derived from organofluorine compounds. The gas may contain, for example, trace amounts of organofluorine compounds desorbed from activated carbon. If at least one gas component selected from the group consisting of water vapor and inert gases is used, the gas may also include that gas component.

[0080] The scrubber apparatus can remove compounds produced by the decomposition of organic fluorine compounds by microwave irradiation (for example, inorganic fluorine compounds such as hydrogen fluoride), as well as organic fluorine compounds that may be present in trace amounts in the gas without being decomposed by microwave irradiation, and recover them without releasing them into the atmosphere.

[0081] By treating the above gas with a wet scrubber, compounds derived from the above organofluorine compounds in the gas can be dissolved or captured in water (without being released into the atmosphere). For example, the gas and liquid water may be brought into countercurrent contact. Specifically, the gas may be blown into a wet scrubber treatment apparatus equipped with a packing material from below, and liquid water (e.g., pure water, tap water, or industrial water) may be sprayed from above, allowing the gas and water to come into sufficient contact as they pass through the packing material.

[0082] The aqueous solution obtained by wet scrubbing (hereinafter also referred to as "scrubber treatment solution") may be treated as wastewater by conventionally known methods. For example, the obtained scrubber treatment solution may be treated with adsorption using activated carbon. For example, if the obtained scrubber treatment solution contains organic fluorine compounds such as so-called PFAS, the organic fluorine compounds can be sufficiently decomposed by adsorbing the solution with activated carbon and then treating the activated carbon again using this apparatus.

[0083] If the gas discharged from the microwave heating vessel contains organic fluorine compounds such as PFAS, the apparatus may further include a device for decomposing the organic fluorine compounds by allowing the gas to remain in a space containing a magnetic material such as SiC, which has been heated by microwave irradiation, for two seconds or more.

[0084] The following describes an embodiment of this device with reference to the drawings. The heat treatment apparatus 1 shown in Figure 1 comprises a microwave heating vessel 10 having a microwave irradiation section 11, an inlet 12 and an outlet 13, and a transfer device 50. The activated carbon AC is placed on a transfer platform 52 and is transferred by the transfer device 50. Figure 2 is a schematic diagram of the μ-wave heating container 10 shown in Figure 1, viewed from upstream to downstream along the transfer path of activated carbon AC. In Figure 2, the μ-wave heating container 10 has an upper boundary portion 12a that is in contact with the opening of the inlet 12, and a lower boundary portion 12b that is in contact with the opening. The size of the gap between the activated carbon AC and the upper boundary portion 12a of the μ-wave heating container 10 is indicated by D1.

[0085] The heat treatment apparatus 1 shown in Figure 3 comprises a μ-wave heating vessel 10, a steam supply device 20, an inert gas supply device 30, and a transfer device 50. The steam supply device 20 comprises a steam generator 22 and a steam supply line L2 connecting the μ-wave heating vessel 10 and the device 22. The inert gas supply device 30 comprises an inert gas storage device 32 and an inert gas supply line L3-1 connecting the μ-wave heating vessel 10 and the device 32. In one embodiment, the heat treatment apparatus 1 shown in Figure 3 may not include the steam supply device 20. The μ-wave heating vessel 10 further includes a steam inlet 14, an inert gas inlet 15, and a gas outlet 16. A steam supply line L2 is connected to the steam inlet 14, an inert gas supply line L3-1 is connected to the inert gas inlet 15, and a gas outlet line L1 is connected to the gas outlet 16. A heating unit (not shown) is provided on the steam supply line L2.

[0086] The heat treatment apparatus 1 shown in Figure 4 comprises a μ-wave heating vessel 10, a steam heating vessel 21, an inert gas supply device 30, a steam supply device 20, and a transfer device 50. The μ-wave heating vessel 10 and the steam heating vessel 21 are arranged from upstream to downstream in the transfer path of the activated carbon AC. The inert gas supply device 30 comprises an inert gas storage device 32, an inert gas supply line L3-1 connecting the μ-wave heating vessel 10 and the device 32, and an inert gas supply line L3-2 connecting the steam heating vessel 21 and the device 32. The steam supply device 20 comprises a steam generator 22 and a steam supply line L2 connecting the steam heating vessel 21 and the device 22. The μ-wave heating vessel 10 further includes an inert gas inlet 15 and a gas outlet 16. An inert gas supply line L3-1 is connected to the inert gas inlet 15, and a gas outlet line L1 is connected to the gas outlet 16. The steam heating vessel 21 includes a steam inlet 24, an inert gas inlet 25, and a gas outlet 26. A steam supply line L2 is connected to the steam inlet 24, an inert gas supply line L3-2 is connected to the inert gas inlet 25, and a gas outlet line L1 is connected to the gas outlet 26.

[0087] The heat treatment apparatus 1 shown in Figure 5 is an embodiment in which the heat treatment apparatus 1 shown in Figure 4 is further equipped with an inert gas heating vessel 31. A μ-wave heating vessel 10, a steam heating vessel 21, and an inert gas heating vessel 31 are arranged from upstream to downstream along the activated carbon AC transfer path. The inert gas supply device 30 further includes an inert gas supply line L3-3 that connects the inert gas heating vessel 31 and the device 32. The inert gas heating container 31 is equipped with an inert gas inlet 35 and an inert gas outlet 36. An inert gas supply line L3-3 is connected to the inert gas inlet 35, and a gas discharge line L1 is connected to the inert gas outlet 36. The heat treatment apparatus 1 shown in Figure 5 does not necessarily have to include a steam heating vessel 21.

[0088] In Figures 1 and 3 to 5, the containers 10, 21, and 31 are housed within the heat treatment container 2. The inert gas supply device 30 shown in Figures 3 to 5 further comprises an inert gas supply line L3A connecting the heat treatment container 2 and the inert gas storage device 32. The heat treatment container 2 is equipped with a gas inlet 5 and a gas outlet 6. The inert gas supply line L3A is connected to the gas inlet 5, and the gas outlet line L1 is connected to the gas outlet 6.

[0089] The heat treatment apparatus 1 shown in Figures 6 and 7 comprises a μ-wave heating vessel 10, a wet scrubber treatment apparatus 40, a gas discharge line L1 connecting the heating vessel 10 and the apparatus 40, and a treated gas discharge line L4 through which the gas discharged from the apparatus 40 flows. The wet scrubber treatment apparatus 40 includes a gas inlet 41 and a treated gas outlet 42. One end of the gas discharge line L1 is connected to the gas outlet 16 and the other end is connected to the gas inlet 41. The treated gas discharge line L4 is connected to the treated gas outlet 42.

[0090] The wet scrubber device 40 comprises a water tank 43 (and water) located at the bottom of the device 40, a water spraying unit 44 (e.g., a spray nozzle) located at the top of the device 40, a mist catcher 45 (e.g., a packing material), a gas inlet 41 into which gas discharged from the microwave heating container 10 by microwave irradiation is introduced, a treated gas outlet 42 into which the gas treated by the wet scrubber is discharged, a circulation line L5 connecting the lower water tank 43 and the water spraying unit 44, and a circulation pump 46 provided on the circulation line L5.

[0091] Water in the lower tank 43 is drawn in by the circulation pump 46 and supplied to the water spraying unit 44 through the circulation line L5. The water sprayed from the water spraying unit 44 falls back into the lower tank 43. The gas discharged from the microwave heating container 10 during microwave irradiation is introduced into the wet scrubber treatment device 40 through the gas discharge line L1 from the gas outlet 16 of the microwave heating container 10 and through the gas inlet 41. The gas comes into contact with the water sprayed from the water spraying unit 44, and after the water-soluble components are dissolved or captured in the water, it is discharged from the treated gas outlet 42. The water in the lower tank 43 is taken out via lines (piping) not shown and sent to a wastewater treatment facility not shown for treatment.

[0092] [Fluid purification treatment device] The continuous heat treatment apparatus for activated carbon of this disclosure may be incorporated into a fluid purification apparatus for purifying fluids containing organofluorine compounds. The purification apparatus also functions as an activated carbon regeneration apparatus.

[0093] [How to regenerate activated carbon] The activated carbon regeneration method of this disclosure includes a microwave irradiation step in which, using the apparatus described above, the activated carbon to which an organofluorine compound is attached is transported and heated to a temperature exceeding 800°C by microwave irradiation treatment.

[0094] In one embodiment, the microwave irradiation step includes irradiating the activated carbon with microwaves while transferring it, thereby maintaining the activated carbon at a temperature exceeding 800°C. The preferred temperature of the activated carbon irradiated with microwaves (the heating temperature of the activated carbon) is as described above. The preferred frequency and power of the microwaves are also as described above.

[0095] In the microwave irradiation process, the temperature of the activated carbon can be maintained at over 800°C (preferably the heating temperature of the activated carbon as described above) for at least one second, ensuring the residence time necessary for the decomposition of the organofluorine compound. The time for maintaining the temperature of the activated carbon above 800°C is as described above. The temperature of the activated carbon mentioned above can be measured using an infrared thermographic camera. In the microwave irradiation process, microwaves are continuously irradiated onto the activated carbon.

[0096] In the microwave irradiation process, the activated carbon may be heated by microwave irradiation, starting from a temperature of 800°C or lower (starting temperature) and rising to over 800°C (preferably the heating temperature of the activated carbon as described above). The preferred starting temperature and the preferred heating rate of the activated carbon are as described above.

[0097] Along with or after microwave irradiation of the activated carbon, the activated carbon may be brought into contact with heated steam. The temperature of the heated steam brought into contact with the activated carbon is preferably 600 to 1200°C, more preferably 650 to 1100°C, even more preferably 700 to 1000°C, and particularly preferably 750 to 900°C.

[0098] The activated carbon after microwave irradiation may be heated with an inert gas. In this case, the temperature of the inert gas is preferably 30 to 800°C, more preferably 50 to 800°C, and even more preferably 100 to 800°C.

[0099] In the microwave irradiation process, the activated carbon may be irradiated with microwaves under an inert gas atmosphere, a water vapor atmosphere, or a mixed gas atmosphere of an inert gas and water vapor.

[0100] The regeneration method of this disclosure may further include a cooling step of cooling the activated carbon after contact with water vapor (including cooling by heat dissipation). The cooling temperature is not particularly limited, but is preferably less than 100°C, more preferably 80°C or lower, even more preferably 60°C or lower, even more preferably 40°C or lower, and especially preferably 30°C or lower, for example, 0°C or higher.

[0101] The regeneration method of this disclosure may further include a removal step to remove compounds derived from the above-mentioned organofluorine compounds from the gas obtained in the microwave irradiation step. In the removal step, it is preferable to wet scrub the gas.

[0102] [Methods for purifying fluids] The fluid purification method of this disclosure comprises a step of bringing a fluid containing an organofluorine compound into contact with activated carbon to cause the organofluorine compound to adhere to the activated carbon (hereinafter also referred to as the "adsorption step"), and a step of regenerating the activated carbon by the regeneration method of this disclosure described above (hereinafter also referred to as the "regeneration step").

[0103] The fluid containing organofluorine compounds that is subject to purification treatment will also be referred to as the "fluid to be treated" below. Examples of fluids include liquids and gases. Examples of liquids include aqueous solutions containing organofluorine compounds (e.g., drinking water, wastewater, effluent, and groundwater). Examples of gases include gases containing organofluorine compounds (e.g., exhaust gas from incineration facilities, etc.). Details regarding the organofluorine compounds and activated carbon are as described above. Details of the playback method are as described above.

[0104] According to the purification method of this disclosure, it is possible to purify fluids containing organic fluorine compounds and to regenerate activated carbon whose adsorption capacity has decreased as a result of this purification treatment.

[0105] [Example of form] This disclosure relates, for example, to the following [1] to

[10] . [1] A continuous heat treatment apparatus for heat-treating activated carbon to which an organofluorine compound is attached, the heat treatment apparatus comprising: a transfer device for transferring activated carbon to which an organofluorine compound is attached; and a microwave heating vessel having a microwave irradiation section, wherein the microwave heating vessel has an inlet for transferring the activated carbon from outside the vessel to inside the vessel by the transfer device; and an outlet for transferring the activated carbon from inside the vessel to outside the vessel after microwave irradiation by the transfer device, and the microwave irradiation section inside the microwave heating vessel is provided to irradiate the activated carbon transferred into the vessel by the transfer device with microwaves. [2] The continuous heat treatment apparatus according to [1], wherein the vertical gap between the activated carbon or its transfer stage passing through the inlet of the μ-wave heating vessel and the upper boundary portion of the μ-wave heating vessel in contact with the opening of the inlet is 100 mm or less, and the vertical gap between the activated carbon or its transfer stage passing through the outlet of the μ-wave heating vessel and the upper boundary portion of the μ-wave heating vessel in contact with the opening of the outlet is 100 mm or less. [3] The continuous heat treatment apparatus according to [1] or [2], wherein the heat treatment apparatus further comprises at least one selected from the group consisting of a steam supply device for supplying steam into the μ-wave heating vessel and a steam heating vessel for heating the activated carbon with steam, located downstream of the μ-wave heating vessel in the transfer path of the activated carbon. [4] The continuous heat treatment apparatus according to any one of [1] to [3], wherein the heat treatment apparatus further comprises at least one selected from the group consisting of an inert gas supply device for supplying an inert gas into the μ-wave heating vessel and an inert gas heating vessel for heating the activated carbon with an inert gas, located downstream of the μ-wave heating vessel in the transfer path of the activated carbon. [5] The continuous heat treatment apparatus according to any one of [1] to [4], wherein the μ-wave heating vessel is housed in a heat treatment vessel, and the heat treatment apparatus further comprises an inert gas supply device that supplies an inert gas into the respective vessels of the μ-wave heating vessel and the heat treatment vessel. [6] The continuous heat treatment apparatus according to any one of [1] to [4], wherein the μ-wave heating vessel is housed in a heat treatment vessel, and the heat treatment apparatus further comprises a steam supply device for supplying steam into the μ-wave heating vessel, and an inert gas supply device for supplying inert gas into the respective vessels of the μ-wave heating vessel and the heat treatment vessel. [7] The continuous heat treatment apparatus according to any one of [1] to [4], wherein the heat treatment apparatus further comprises a steam heating vessel for heating the activated carbon with steam downstream of the μ-wave heating vessel in the transfer path of the activated carbon, the μ-wave heating vessel and the steam heating vessel are housed in a heat treatment vessel, and the heat treatment apparatus further comprises an inert gas supply device for supplying an inert gas into each of the containers of the μ-wave heating vessel, the steam heating vessel and the heat treatment vessel. [8] The continuous heat treatment apparatus according to any one of [1] to [4], wherein the heat treatment apparatus further comprises, in the transfer path of the activated carbon, a steam heating vessel for heating the activated carbon with steam downstream of the μ-wave heating vessel, and an inert gas heating vessel for heating the activated carbon with an inert gas downstream of the steam vessel, wherein the μ-wave heating vessel, the steam heating vessel and the inert gas heating vessel are housed in a heat treatment vessel, and the heat treatment apparatus further comprises an inert gas supply device for supplying an inert gas into each of the containers of the μ-wave heating vessel, the steam heating vessel, the inert gas heating vessel and the heat treatment vessel. [9] The continuous heat treatment apparatus according to any one of [1] to [8], wherein the microwave irradiation unit in the heating container is provided so as to be able to irradiate the activated carbon being transported in the container by the transport device with microwaves.

[10] A method for regenerating activated carbon, comprising a microwave irradiation step of heating the activated carbon to a temperature exceeding 800°C by microwave irradiation treatment while transferring the activated carbon to which an organofluorine compound is attached using a continuous heat treatment apparatus described in any of [1] to [9] above. [Explanation of Symbols]

[0106] 1…Heat treatment apparatus, 2…Heat treatment vessel, 5…Gas inlet, 6…Gas outlet, 10…Microwave heating vessel, 11…Microwave irradiation section, 12…Inlet of transfer device, 13…Outlet of transfer device, 14…Steam inlet, 15…Inert gas inlet, 16…Gas outlet, 20…Steam supply device, 21…Steam heating vessel, 22…Steam generator, 24…Steam inlet, 25…Inert gas inlet, 26…Gas outlet, 30…Inert gas supply device, 31…Inert gas heating vessel, 32…Inert Inert gas storage device, 35...Inert gas inlet, 36...Inert gas outlet, 40...Wet scrubber treatment device, 41...Gas inlet, 42...Treatment gas outlet, 43...Water tank, 44...Spraying unit, 45...Mist catcher, 46...Circulation pump, 50...Transfer device, 52...Transfer platform, L1...Gas discharge line, L2...Steam supply line, L3-1, L3-2, L3-3, L3A...Inert gas supply line, L4...Treatment gas discharge line, L5...Circulation line, AC...Activated carbon

Claims

1. A continuous heat treatment apparatus for heat-treating activated carbon to which organofluorine compounds are attached, The heat treatment apparatus is A transfer device for transporting activated carbon to which organic fluorine compounds are attached, A microwave heating vessel having a microwave irradiation section, Equipped with, The microwave heating vessel has an inlet for transferring the activated carbon from outside the vessel to inside the vessel by the transfer device, and an outlet for transferring the activated carbon, after microwave irradiation, from inside the vessel to outside the vessel by the transfer device. The microwave irradiation unit within the microwave heating container is provided so as to be able to irradiate the activated carbon, which has been transferred into the container by the transfer device, with microwaves. Continuous heat treatment apparatus.

2. The vertical gap between the activated carbon or its transfer platform passing through the inlet of the μ-wave heating vessel and the upper boundary portion of the μ-wave heating vessel that is in contact with the opening of the inlet is 100 mm or less. The vertical gap between the activated carbon or its transfer platform passing through the outlet of the μ-wave heating vessel and the upper boundary portion of the μ-wave heating vessel that is in contact with the opening of the outlet is 100 mm or less. The continuous heat treatment apparatus according to claim 1.

3. The heat treatment apparatus, A steam supply device that supplies steam into the aforementioned μ-wave heating container, and In the transfer path for the activated carbon, downstream of the μ-wave heating vessel, there is a steam heating vessel for heating the activated carbon with steam. The group further comprises at least one selected from the group consisting of, The continuous heat treatment apparatus according to claim 1.

4. The heat treatment apparatus, An inert gas supply device for supplying inert gas into the aforementioned microwave heating container, and In the activated carbon transfer path, downstream of the μ-wave heating vessel, there is an inert gas heating vessel for heating the activated carbon with an inert gas. The group further comprises at least one selected from the group consisting of, The continuous heat treatment apparatus according to claim 1.

5. The aforementioned μ-wave heating vessel is housed within the heat treatment vessel. The heat treatment apparatus further comprises an inert gas supply device that supplies an inert gas into the respective containers of the μ-wave heating vessel and the heat treatment vessel. The continuous heat treatment apparatus according to claim 1.

6. The aforementioned μ-wave heating vessel is housed within the heat treatment vessel. The heat treatment apparatus further comprises a steam supply device that supplies steam into the μ-wave heating vessel, and an inert gas supply device that supplies inert gas into the respective containers of the μ-wave heating vessel and the heat treatment vessel. The continuous heat treatment apparatus according to claim 1.

7. The heat treatment apparatus further includes, in the transfer path of the activated carbon, a steam heating vessel for heating the activated carbon with steam, located downstream of the μ-wave heating vessel. The aforementioned μ-wave heating vessel and the aforementioned steam heating vessel are housed within the heat treatment vessel. The heat treatment apparatus further comprises an inert gas supply device that supplies an inert gas into each of the containers: the microwave heating container, the steam heating container, and the heat treatment container. The continuous heat treatment apparatus according to claim 1.

8. The heat treatment apparatus further comprises, in the transfer path of the activated carbon, a steam heating vessel for heating the activated carbon with steam, located downstream of the μ-wave heating vessel, and an inert gas heating vessel for heating the activated carbon with an inert gas, located downstream of the steam vessel. The aforementioned μ-wave heating vessel, the steam heating vessel, and the inert gas heating vessel are housed within the heat treatment vessel. The heat treatment apparatus further comprises an inert gas supply device that supplies inert gas into each of the following containers: the microwave heating container, the steam heating container, the inert gas heating container, and the heat treatment container. The continuous heat treatment apparatus according to claim 1.

9. The continuous heat treatment apparatus according to claim 1, wherein the microwave irradiation unit in the heating container is provided so as to be able to irradiate the activated carbon being transported inside the container by the transport device with microwaves.

10. A method for regenerating activated carbon, comprising a microwave irradiation step of heating activated carbon to a temperature exceeding 800°C by microwave irradiation treatment while transferring activated carbon to which an organofluorine compound is attached, using a continuous heat treatment apparatus according to any one of claims 1 to 9.

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