JP4332499B2 - Heating method of activated carbon - Google Patents

Description

  The present invention relates to a method of heating activated carbon by irradiating the activated carbon whose surface is covered with a heat-resistant and electrically insulating coating material by applying microwaves or applying a high frequency. Further, the present invention relates to a method of recovering the adsorbed solvent or gas by heating the activated carbon by a simple method after adsorbing the solvent or gas using the coated activated carbon. Furthermore, it is related with the catalytic reaction method which applied the heating method of this activated carbon.

In factories that handle a large amount of solvent, a method is widely used in which a volatilizing solvent is adsorbed on activated carbon and later desorbed and recovered. However, the method of desorbing the adsorbed solvent is generally a steam heating method, and requires a boiler, a condenser, a decanter, and the like. In addition, separation of the desorbed solvent and water is difficult, and the solvent recovery apparatus becomes large, resulting in high equipment costs and running costs. For this reason, small-scale establishments that handle solvents, such as dry cleaning shops and paint factories, are not equipped with much solvent recovery devices, and the present situation is that a part of the solvent is diffused into the atmosphere. Activated carbon is also used for gas purification, malodorous gas, and adsorption and removal of toxic gases, but heating the activated carbon that has adsorbed these gases can cause the gas to be released from the activated carbon. Exists.
Activated carbon is used as a catalyst for various chemical reactions or as a catalyst carrier. In general, the catalytic reaction often requires heating. In this case, it is necessary to heat the gas to be processed and the entire apparatus with a large apparatus, and a large amount of energy is consumed.
Therefore, if the solvent can be desorbed and recovered from the activated carbon by a simple method without using water vapor, it will be possible to recover the solvent with simple equipment even in a small-scale office, which should lead to prevention of air pollution. The present invention intends to provide a heating method of activated carbon that can safely and easily desorb and recover the solvent and gas adsorbed on the activated carbon without using water vapor, and a solvent recovery method using the method. It is. Furthermore, the present invention also provides a method for safely and efficiently regenerating activated carbon used for gas purification, odor gas and harmful gas removal.
In addition, in a catalytic reaction apparatus using activated carbon, if the activated carbon can be efficiently heated and heated, energy-saving operation by a small facility becomes possible. The present invention provides a catalytic reaction method using activated carbon which can heat and raise the temperature of activated carbon itself as a catalyst safely and efficiently.

Instead of desorbing the solvent or gas from the activated carbon that has adsorbed the solvent or gas with water vapor, the activated carbon is directly irradiated with microwaves or the activated carbon is heated to desorb the adsorbed solvent or gas. Can be considered. However, activated carbon is prone to electrical breakdown, and there is a major problem in that when a microwave is irradiated, a discharge phenomenon occurs and sparks fly, and the activated carbon ignites, burns, and explodes. In order to prevent this, Japanese Patent Publication No. 6-31163 proposes a method of circulating an inert gas in a layer filled with activated carbon. However, in this method, heating cannot be performed uniformly, and it is necessary to replace the entire inside of the apparatus with an inert gas, so that there is a problem that the apparatus becomes heavy and large, and the cost increases.
Therefore, as a result of intensive studies to solve this problem, the present inventors have coated the surface of activated carbon with a heat-resistant and electrically insulating coating material so that the particles of activated carbon are not in direct contact with each other. Even if the coated activated carbon is irradiated with microwaves in the air (in the presence of oxygen), spark discharge does not occur, and therefore the activated carbon itself does not ignite or burn safely, easily and within a short time. It was found that it was possible to heat to the target temperature.
That is, the present invention
(1) A method for heating activated carbon in which activated carbon coated with a heat-resistant and electrically insulating coating material is irradiated with microwaves or applied with a high frequency,
(2) The method for heating activated carbon according to (1), wherein the coating material is a heat-resistant coating material that is physically and chemically stable at 200 ° C. or lower,
(3) The method for heating activated carbon according to (1) or (2), wherein the coating material is an electrically insulating coating material having an electrical resistivity of 1 Ωm or more,
(4) The method for heating activated carbon according to (1), wherein the ash content in the activated carbon is 15% by weight or less.
(5) The method for heating activated carbon according to (1), wherein the weight ratio of the activated carbon to the coating material is 200: 1 to 2: 1.
(6) The activated carbon heating method according to (1), wherein the shape of the activated carbon covered with the coating material is granular, and the average particle diameter is 0.1 to 50 mm,
(7) The heating method of activated carbon according to any one of (1) to (3), wherein the coating material is an inorganic oxide, clay mineral, or ferrite compound,
(8) The method for heating activated carbon according to (1), which is coated with a coating material containing water glass,
(9) The activated carbon coated with a heat-resistant and electrically insulating coating material is packed in a packed tower, adsorbed with a solvent or gas, and then adsorbed by irradiation with microwaves or application of high frequency and heating. A solvent recovery method for desorbing
(10) After filling the reactor with activated carbon that may be coated with a heat-resistant and electrically insulating coating material and may carry a catalyst component, the reaction is accelerated by applying microwaves or applying high-frequency heat. Catalytic reaction method,
It is.
Many techniques have been reported so far for coating activated carbon surfaces with various substances and imparting new physical properties and functions, but most of them are aimed at improving hydrophilicity and suppressing the generation of fine powder. None of the inventions aimed at heating by microwaves or the like as in the invention, solvent recovery, or heating catalytic reaction acceleration. When the coated activated carbon of the present invention is used, if a microwave irradiation device or a high-frequency application device and a simple condenser are used, a solvent or gas can be recovered by heating or a catalytic reaction can be performed even with a small-scale device. There is no need to replace with active gas.
The activated carbon used in the present invention is activated carbon whose surface is coated with an inorganic material such as silica, alumina, titania, or a coating material having heat resistance and electrical insulation properties such as fluorine resin, phenol resin, and polyester resin. . In the case of activated carbon with no coating, partial heating may occur, the temperature rise may not be stable, spark discharge may occur, and the activated carbon itself may ignite and burn. In contrast, the coated activated carbon used in the present invention can maintain a uniform and stable temperature rise according to the output of microwave irradiation. If this property is utilized, the solvent can be safely and easily desorbed from the activated carbon adsorbed with the solvent.
The activated carbon used in the present invention may be any activated carbon suitable for solvent and gas recovery and heat catalytic reaction. However, if the amount of ash contained in the activated carbon is large, the calorific value when adsorbing the solvent is large and the ignition point is lowered, so that the amount of ash contained in the activated carbon is preferably 15% by weight or less, preferably 10% by weight or less. More preferred are those with 7% or less. This activated carbon having a low ash content can be obtained by washing activated carbon containing ash with an aqueous solution containing an acid such as water or hydrochloric acid.
The raw materials for activated carbon are plant fruits (such as palm husk and candle nut husk), coal (brown coal, bituminous coal, anthracite, etc.), pitch, tar, wood flour (such as sawdust), and synthetic resins (phenol resin, vinylidene chloride resin, etc.) Anything that is generally used can be used. Of these, fruits, particularly those derived from coconut shells, and coals, particularly those derived from bituminous coal, are preferred in terms of stable supply and performance.
The activation method is not particularly limited. For example, activated charcoal activated by an active gas such as water vapor, oxygen, carbon dioxide gas, phosphoric acid, zinc chloride manufactured by the method of “activated carbon industry, heavy chemical industry communication company (1974), p.23-p.37” Activated carbon such as chemical activated charcoal using etc. is used. The BET specific surface area of the activated carbon as a raw material is 500 to 2500 m ² / g, preferably 700 to 2000 m ² / g, and most preferably 800 to 1800 m ² / g.
The particle size of the activated carbon is not particularly limited, but usually an activated carbon having an average particle size of 0.1 to 50 mm is used. Preferably it is 0.2-30 mm, More preferably, it is 0.5-10 mm.
The shape of the activated carbon may be a crushed one or a molded body (such as a cylinder or a sphere). The molding may be performed by molding powdered activated carbon into a predetermined shape, or by activating a previously molded raw material into activated carbon. Of these, spherical ones are particularly preferable because the substance to be coated is easily coated on the activated carbon surface with a uniform thickness.
In order to form the activated carbon into a spherical shape, a rolling granulator or the like may be used, and there are methods such as spheroidizing what is extruded into a pellet form with an apparatus such as a Malmerizer.
The heat-resistant and electrically insulating coating material used in the present invention is a material that does not ignite at 200 ° C. or less, is physically and chemically stable without undergoing a heat change, and is unlikely to cause electrical breakdown, that is, electrical insulation. If it is a body. More specifically, at a temperature of 200 ° C. or less, it has heat resistance that does not ignite and is not subject to thermal change, and has an electrical resistivity (volume resistivity) of 1 Ωm or more, preferably 10 ³ Ωm or more, and more preferably Is 10 ⁵ Ωm or more. Among the specific examples of the coating agent, inorganic substances include alumina (electric specific resistance of about 10 ¹² Ωm), silica (electric specific resistance of about 10 ¹⁰ Ωm), zirconia (electric specific resistance of about 10 ¹² Ωm), titania. (Electric specific resistance of about 10 ¹¹ Ωm), iron oxide (electric specific resistance of about 10 ¹¹ Ωm), inorganic oxides such as calcium oxide (electric specific resistance of about 10 ¹⁰ Ωm), iron nickel ferrite (electric specific resistance of about 10 ¹⁰ Ωm) ), iron zirconium ferrite (electrical resistivity of about 10 ³ [Omega] m), nickel-zinc ferrite (electrical resistivity of about ^{10 10} [Omega] m) soft ferrite, yttrium iron garnet (electrical resistivity of about ^{10 10} [Omega] m) garnet ferrite such as such as ferrite compounds such as, an alloy such as iron chrome, single metals such as nickel (electrical resistivity of about 10 ⁹ [Omega] m), more kaolin Electrical resistivity of about ^{10 11} [Omega] m), talc (electrical resistivity of about ^{10 12} [Omega] m), sepiolite (electrical resistivity of about ^{10 11} [Omega] m), bentonite (electrical resistivity of about ^{10 11} [Omega] m) clay minerals, such as soda-lime glass ( Examples thereof include glasses such as electric specific resistance of about 10 ¹¹ Ωm), water glass (electric specific resistance of about 10 ¹⁰ Ωm), and borosilicate glass (electric specific resistance of about 10 ¹³ Ωm). Examples of organic substances include fluorine resin (electrical resistivity of about 10 ¹⁵ Ωm), phenolic resin (electrical resistivity of about 10 ¹¹ Ωm), polyester resin (electrical resistivity of about 10 ¹¹ Ωm), and vinyl chloride resin (electrical resistivity of about 10 ¹¹ Ωm). 10 ¹³ Ωm) and vinylidene chloride resin (electric specific resistance of about 10 ¹³ Ωm). You may use a coating | covering material individually or in combination of multiple.
The average particle size of the particles of the coating material is not particularly limited, but those having a particle size of 0.1 to 200 micrometers, preferably 0.5 to 100 micrometers are easy to use.
The amount of the coating material used is, based on dryness, the weight of activated carbon: the total weight of the coating material is 200: 1 to 2: 1, preferably 100: 1 to 3: 1, more preferably 50: 1 to 4: 1. It is.
Although the thickness of a coating layer is based also on the particle diameter of activated carbon, it is 0.1 micrometer-5 millimeters, Preferably, they are 0.5 micrometer-1 millimeter.
As a method for coating the surface of the activated carbon with the coating material, a known method is used. For example, it is difficult to penetrate the coating material into the pores of the activated carbon, and the coating material is diluted with a solution of an appropriate binder that covers the activated carbon particles by adhering the coating material to the surface of the activated carbon, and the activated carbon is immersed in this and dried ( Impregnation method), a method of spraying and drying the solution containing the coating material on the surface of the activated carbon (spraying method), and a method of passing the solution containing the coating material and drying in a state where the activated carbon is fluidized (flow method). Etc. Although the coating material may also serve as a binder function, other binders and viscosity modifiers may be further mixed if necessary. Although the surface of the activated carbon particles is coated with the coating material by this coating operation, the activated carbon particles do not enter the pores and have little influence on the entry and exit of the solvent and the like.
In contrast, when dissolved ions and ultrafine particles (molecular level) are dispersed in a solution that easily penetrates into activated carbon pores and supported by impregnation, etc., ions and ultrafine particles are placed inside the pores. Also penetrates and adheres to the inner wall, but the entire surface of the activated carbon particles is not covered.
The term “coating” in this case refers to fixing to the activated carbon surface, not fixing to the inside of the activated carbon pores as supported.
There are organic and inorganic binders and viscosity modifiers. Examples of the organic binder and viscosity modifier include latex resins such as polyurethane, polystyrene, and vinylidene chloride. Examples of the inorganic binder include water glass (sodium silicate) and silica alumina ceramics. Among these, water glass is particularly preferable. Water glass and silica-alumina are preferable examples because they serve as binders and also serve as silica coating. Water glass is covered with activated carbon and dried as silica (silicon dioxide) by drying. Moreover, the coating material, the binder, and the viscosity modifier may each be one kind or two or more kinds. The usage-amount of a binder and a viscosity modifier is 0.01-10 weight part with respect to 100 parts of coating | covering materials, Preferably, it is 0.1-5 weight part. However, those that themselves serve as a coating, such as water glass and silica alumina ceramics, are not limited thereto.
The microwave is an electromagnetic wave having a wavelength of 0.1 mm to 1 m, and any microwave having a wavelength of 300 MHz to 300 GHz can be used for convenience. Among them, a microwave of 2.45 GHz and 500 W is easily available. The high frequency to be applied has a wavelength of 1 kHz to 10 MHz, preferably 10 kHz to 1 MHz.
A method for recovering an organic solvent adsorbed by activated carbon using the present invention will be described.
The solvent is adsorbed onto the activated carbon by passing a gas containing the solvent through a tower packed with activated carbon coated with a coating material. After the activated carbon has adsorbed the solvent until the adsorption breakthrough state, the activated carbon is irradiated with a microwave or the like. The coated activated carbon in the packed bed is heated by heating the activated carbon by irradiation with microwaves or the like, and the temperature rises. However, since the activated carbon particles are not in direct contact, there is no ignition or combustion. The solvent adsorbed by heating is desorbed from the activated carbon, and the activated carbon is regenerated. The desorbed solvent is condensed and recovered by the condenser. At this time, since the conventional steam is not used, the recovery of the solvent becomes very easy and the apparatus can be miniaturized. Further, separation from a large amount of water is unnecessary, and a solvent dissolved in a minute amount is not mixed in the waste water.
When water is also adsorbed in the activated carbon, water is also released at the same time, but the amount is small and separation is easy.
The irradiation amount of microwaves and the like is determined so as to be equal to or higher than the temperature at which the adsorbed substance is desorbed from the activated carbon. Usually, the temperature required for desorption is 120 ° C. or higher. This temperature can be controlled by the amount of microwave irradiation. At this temperature, moisture adsorbed with the solvent is also desorbed, which is preferable for the regeneration of activated carbon. The upper limit of the temperature when heating is the temperature at which the activated carbon does not burn, and it is usually desirable to keep it below about 400 ° C. The packed tower may be a fixed bed, a moving bed or a fluidized bed.

The solvent to be recovered is not particularly limited as long as it can be adsorbed by activated carbon. For example, aliphatic hydrocarbons such as gasoline, petroleum, kerosene, kerosene, mineral spirits, naphtha, pentane, hexane, heptane, octane, for example, aromatic hydrocarbons such as benzene, toluene, xylene, for example, 1,3-dichloro Propene, dichloromethane, chloroform, 1,2-dichloroethane, 1,1-dichloroethylene, cis-1,2-dichloroethylene, trans-1,2-dichloroethylene, 1,1,1-trichloroethane, 1,1,2-trichloroethane, Volatile organic chlorine compounds such as trichlorethylene, tetrachloroethylene, carbon tetrachloride, for example, ketones such as acetone, ethyl methyl ketone, diethyl ketone, isobutyl methyl ketone, cyclohexane, such as methyl acetate, ethyl acetate, propyl acetate, Esters such as methyl acid, ethyl formate and propyl formate, for example, ethers such as diethyl ether, isopropyl ether, furfural, tetravidrofuran and dioxane, for example, alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol and butyl alcohol Etc.
Further, the method of the present invention can be applied not only to recovering a solvent, but also to regenerating activated carbon used for gas purification or the like. For example, methane fermentation gas from natural gas, propane gas, and sludge contains hydrocarbons with a high boiling point, and activated carbon is used to remove them, but activated carbon that has adsorbed impurities by the method of the present invention is used on site. Can be played easily. In addition, when activated carbon is used to remove other malodorous gases and harmful gases, the used activated carbon can be regenerated in the same manner.
Next, a method for heating the catalytic reaction apparatus using the heating method of the present invention will be described.
First, the activated carbon is charged into the catalytic reactor. In this case, a catalyst metal previously supported on activated carbon is used as necessary. The catalytic metal may be supported after being coated, but it is desirable to be supported on activated carbon before coating with the coating material. Reactants are circulated through the catalytic reactor. At this time, microwaves are irradiated and heated to a temperature suitable for the reaction. Only activated carbon can be efficiently heated by such a method, resulting in an energy-saving and small reactor.

Fig. 1 Temperature change of uncoated activated carbon by microwave irradiation Fig. 2 Temperature change of coated activated carbon by microwave irradiation Fig. 3 Measurement of spark discharge of uncoated activated carbon by microwave irradiation Fig. 4 Measurement of coated activated carbon by microwave irradiation Measurement of spark discharge Fig. 5 Temperature change of activated carbon covered with xylene by microwave irradiation

  Hereinafter, the present invention will be described with reference to examples. However, the present invention is not limited to the examples.

Preparation of coated activated carbon In a ratio shown in Table 1, talc (manufactured by Wako Pure Chemical Industries, Ltd .: electric specific resistance of about 10) was added to water glass diluted by water (manufactured by Wako Pure Chemical Industries, Ltd., sodium silicate: electric specific resistance of about 10 ¹⁰ Ωm). ¹² Ωm) was dispersed. Spherical activated carbon (Nippon Enviro Chemicals Co., Ltd. Spherical Coal XS-7100; average particle size 1.0 mm; ash content 3 wt%; electrical resistivity 10 ⁻⁵ Ωm, or Kureha Chemical Industries Co., Ltd. bead charcoal; The talc / water glass solution was sprayed over 30 minutes while rolling an average particle diameter of 0.7 mm; ash content of 0.5 wt%; electrical specific resistance of about 10 ⁻⁵ Ωm) to coat the activated carbon surface. This was put into a dryer at 115 ° C. and sufficiently dried to obtain a sample of coated activated carbon.

Examples 2-6

なお、前記実施例で用いられた活性炭（元炭）のうち、ＸＬ−７１００は、平均粒子径２．５ｍｍ；灰分３ｗｔ％；電気比抵抗１０^−５Ωｍの球状活性炭（日本エンバイロケミカルズ株式会社製）、Ｘ−７１００は、平均粒子径１．３ｍｍ；灰分３ｗｔ％；電気比抵抗１０^−５Ωｍの球状活性炭（日本エンバイロケミカルズ株式会社製）である。
実験例１
マイクロ波照射試験
導波管式マイクロ波照射装置のアプリケータ部中央に内径１０ｍｍの石英製Ｕ字管を置いた。そのＵ字管に約２ｃｍの高さに比較例１の被覆されていない活性炭を充填した。その活性炭の中央部に光ファイバー型温度計センサーを入れ、温度をモニターしながら２．４５ＧＨｚ、２００Ｗのマイクロ波を照射した。その結果を図１に示した。
またこのとき、火花放電の様子は、フォトセンサーからの信号をオシロスコープ（Ｔｅｋｔｒｏｎｉｘ ＴＤＳ２２０）に取り込んで図３に示した。すなわち、図３における縦軸のピークが火花放電の発生を示している。
同じ要領で、実施例１の被覆活性炭についても実験を行った。その結果を、図２および図４に示した。被覆活性炭は、マイクロ波照射によっても温度が安定しており、また火花放電も観察されなかった。
他の実施例によって得られた被覆活性炭についても同じ実験をした結果、全て実施例１の実験とほぼ同様の結果が得られた。
実験例２
溶剤の吸脱着試験
上記のＵ字管に、実施例７の被覆活性炭を約２ｃｍの高さになるように充填した。このカラムにキシレン１０００ｐｐｍを含む窒素ガスを２５℃で、１時間流通させ、キシレンを活性炭に吸着させた。キシレンの吸着終了後、Ｕ字管に空気を流通させながら、マイクロ波（２．４５ＧＨｚ、２００Ｗ）を６分間照射した。その結果、活性炭の温度は急速に上昇し、約１分で１４０℃に達し、一定となった。その時の活性炭の温度変化を図５に示した。マイクロ波照射前と照射後の活性炭の重量から、マイクロ波照射の温度上昇により、吸着していたキシレンの９０％が脱離したことが判明した。また、脱離したキシレンを含む空気を、コンデンサーで冷却することにより、容易にキシレンを液化し回収することができた。
実験例３
触媒反応の実験
マイクロ波照射実験に用いたと同じ装置に、白金を１重量％担持した活性炭に、実施例８と同様の組成で被覆した活性炭を得た。これを上記と同様のＵ字管に充填し、空気を流通させながら、マイクロ波（２．４５ＧＨｚ、２００Ｗ）を５分照射した。その結果、活性炭の温度は急速に上昇し、約１分で１４０℃に達し、一定となった。この状態のまま反応ガスを流すことにより、触媒反応を実施することができる。In the same manner as in Example 1 with the compositions described in Examples 2 to 6 in Table 1, the surface of the activated carbon was coated to obtain coated spherical activated carbon.
Examples 7 and 8
A solution in which nickel zinc ferrite (synthetic product, electrical resistivity of about 10 ¹⁰ Ωm) is dispersed in water glass diluted with water with the composition described in Examples 7 and 8 in Table 1 in the same manner as in Example 1. And coated on the surface of spherical activated carbon.
Comparative Examples 1 and 2
The uncoated activated carbon of Comparative Examples 1 and 2 was obtained by using raw coal as it was.

Among the activated carbons (original coals) used in the above examples, XL-7100 has an average particle diameter of 2.5 mm; an ash content of 3 wt%; an electrical resistivity of 10 ⁻⁵ Ωm, and spherical activated carbon (manufactured by Nippon Enviro Chemicals Co., Ltd.). ), X-7100 is a spherical activated carbon (manufactured by Nippon Enviro Chemicals Co., Ltd.) having an average particle size of 1.3 mm; an ash content of 3 wt%; and an electrical resistivity of 10 ⁻⁵ Ωm.
Experimental example 1
Microwave irradiation test A quartz U-shaped tube having an inner diameter of 10 mm was placed in the center of the applicator portion of the waveguide type microwave irradiation apparatus. The U-tube was filled with uncoated activated carbon of Comparative Example 1 to a height of about 2 cm. An optical fiber type thermometer sensor was placed in the center of the activated carbon, and a microwave of 2.45 GHz and 200 W was irradiated while monitoring the temperature. The results are shown in FIG.
At this time, the state of the spark discharge is shown in FIG. 3 in which a signal from the photosensor is taken into an oscilloscope (Tektronix TDS220). That is, the peak on the vertical axis in FIG. 3 indicates the occurrence of spark discharge.
In the same manner, the experiment was also performed on the coated activated carbon of Example 1. The results are shown in FIG. 2 and FIG. The coated activated carbon was stable in temperature even by microwave irradiation, and no spark discharge was observed.
As a result of conducting the same experiment on the coated activated carbon obtained in other examples, almost the same result as the experiment of Example 1 was obtained.
Experimental example 2
Solvent adsorption / desorption test The above-mentioned U-shaped tube was filled with the coated activated carbon of Example 7 to a height of about 2 cm. Nitrogen gas containing 1000 ppm of xylene was passed through this column at 25 ° C. for 1 hour to adsorb xylene on the activated carbon. After completion of the xylene adsorption, microwaves (2.45 GHz, 200 W) were irradiated for 6 minutes while air was passed through the U-tube. As a result, the temperature of the activated carbon rapidly rose and reached 140 ° C. in about 1 minute and became constant. The temperature change of the activated carbon at that time is shown in FIG. From the weight of the activated carbon before and after the microwave irradiation, it was found that 90% of the adsorbed xylene was desorbed due to the temperature increase of the microwave irradiation. In addition, xylene was easily liquefied and recovered by cooling the air containing the desorbed xylene with a condenser.
Experimental example 3
Catalytic Reaction Experiment Activated carbon coated with the same composition as in Example 8 on activated carbon carrying 1% by weight of platinum in the same apparatus used for the microwave irradiation experiment was obtained. This was filled in a U-shaped tube similar to that described above, and irradiated with microwaves (2.45 GHz, 200 W) for 5 minutes while circulating air. As a result, the temperature of the activated carbon rapidly rose and reached 140 ° C. in about 1 minute and became constant. The catalytic reaction can be carried out by flowing the reaction gas in this state.

  The method of heating activated carbon whose surface is covered with a heat-resistant and insulating coating material by microwave irradiation or the like of the present invention does not generate spark discharge even when irradiated with microwaves or the like in an atmosphere containing oxygen. The activated carbon itself can be raised to the target temperature easily and uniformly within a short time without burning the activated carbon. In addition, since it can be carried out by a small-scale apparatus, it can be carried out at a small-scale establishment that handles solvents such as dry cleaning shops and paint shops, and can also be applied to regeneration of activated carbon for gas purification and heating reaction using an activated carbon catalyst.

Claims (10)

A method for heating activated carbon, in which activated carbon coated with a heat-resistant and electrically insulating coating material is irradiated with microwaves or applied with a high frequency. The method for heating activated carbon according to claim 1, wherein the coating material is a heat-resistant coating material that is physically and chemically stable at a temperature of 200 ° C or lower. The method for heating activated carbon according to claim 1 or 2, wherein the coating material is an electrically insulating coating material having an electrical specific resistance of 1 Ωm or more. The method for heating activated carbon according to claim 1, wherein the ash content in the activated carbon is 15% by weight or less. The method for heating activated carbon according to claim 1, wherein the weight ratio of the activated carbon to the coating material is 200: 1 to 2: 1. The method for heating activated carbon according to claim 1, wherein the shape of the activated carbon covered with the coating material is granular, and the average particle diameter is 0.1 to 50 mm. The method for heating activated carbon according to any one of claims 1 to 3, wherein the coating material is an inorganic oxide, clay mineral, or ferrite compound. The method for heating activated carbon according to claim 1, wherein the activated carbon is coated with a coating material containing water glass. The activated carbon coated with a heat-resistant and electrically insulating coating material is packed in a packed tower, adsorbs the solvent or gas, and then desorbs the adsorbed solvent or gas by applying microwaves or applying high frequency and heating. Recovery method of solvent or gas to be made. Catalytic reaction that accelerates the reaction by heating the reactor with activated carbon coated with a heat-resistant and electrically insulating coating material, which may carry a catalyst component, and then applying microwaves or applying high frequency to heat the reactor. Method.

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