JP2014084262A - Method for producing active carbon - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing active carbon having a low metal content by activating granular carbide of cellulose acetate.SOLUTION: Regarding the method for producing active carbon, in an external heat type rotary kiln including: a heat resistant cylindrical body 13; hoods 14, 15 on both the edge parts thereof; a feed port 16 for the granular carbide of cellulose acerate provided at the hood 14; and an exhaust passage 17 for the activation-treated granular carbide provided at the hood 15, the granular carbide fed to the heat resistant cylindrical body via the feed port are heated in the presence of an activation gas so as to be activated, and are then exhausted via the exhaust passage, the activation is performed using water vapor as the activation gas and also using the heat resistant cylindrical body 13 in which at least the inside surface is formed from a ceramic material, and the exhaust of the granular carbide is performed using the hood 15 in which at least the exhaust passage and the surface region including the surrounding of the exhaust port are formed from a ceramic material.

Description

  The present invention relates to a method for producing activated carbon by activating particulate carbide, and more particularly to a method for producing activated carbon having a low metal content useful as an electrode active material for capacitors.

  Activated carbon is widely used in various industrial fields, and is used for air purification, radioactive substance adsorption, iodine trap, methane occlusion, hydrogen occlusion, purified water production, solvent recovery, decolorization, water treatment, gas mask and the like. In recent years, it is also used as an electrode active material for capacitors (electric double layer capacitors, lithium ion capacitors). Among these, activated carbon used as the electrode active material of the capacitor is desired to contain as little impurities as possible (for example, iron content of 50 ppm or less) as an impurity in order to improve the durability of the capacitor.

  Activated carbon is usually produced by heating a carbonized material obtained by carbonizing a plant material typified by coconut shell by heating to a high temperature in the presence of an activation gas inside an activation device (rotary kiln). . The activated carbon that is produced incorporates the metal that has been mixed into the plant material. For example, in the case of a coconut shell, the raw material contains heavy metals such as several tens of ppm of iron, is concentrated in the carbonization or activation process, and may be present in several hundred ppm in the activated carbon. For this reason, in order to use the produced activated carbon as the electrode active material of the capacitor, an extremely complicated operation of repeatedly washing the activated carbon with an acid or alkali is required.

  On the other hand, it is also known to use cellulose acetate as a raw material for activated carbon. Cellulose acetate is formed into a film or fiber and is used for various applications. For example, a cellulose acetate film is used as a protective film for a polarizing plate provided in a liquid crystal display device. Moreover, the lump of cellulose acetate fiber is used as a tobacco filter. When cellulose acetate is used as a raw material for activated carbon, defective products, non-standard products, or mill ends that are generated in large quantities in the production process of the protective film and tobacco filter can be effectively used. Furthermore, since cellulose acetate does not contain a metal component, the activated carbon to be produced should contain almost no metal in principle.

  Patent Document 1 discloses a method for producing activated carbon for the purpose of reusing a cellulose acylate (eg, cellulose acetate) film as a raw material for activated carbon. In this production method, activated carbon is produced by activating a carbide produced by carbonizing an organic substance mainly composed of cellulose acylate. In Example 1 of this document, activated carbon is manufactured by heating carbide supplied to a rotary kiln (heat-resistant cylindrical body) in the presence of carbon dioxide gas (activation gas).

  Patent Document 2 discloses a method for producing activated carbon by carbonizing cellulose acetate and then removing the remaining acetic acid by heating at a predetermined temperature and activating the resulting carbide. This document describes that it is preferable to use a rotary kiln for the activation process. Moreover, it is described that the activated carbon manufactured by the said method is useful as an electrode active material of an electric double layer capacitor.

  Patent Document 3 discloses a quartz rotary kiln (quartz glass heat-resistant cylinder) made of a quartz glass tube, a charging means for charging carbide before activation from one side of the quartz rotary kiln, and water vapor (activating gas) into the quartz rotary kiln. There is disclosed an activated carbon production apparatus provided with a water vapor supply means for supplying, and a radiant heating means for heating carbide conveyed through the quartz rotary kiln from the outside of the rotating quartz rotary kiln by radiant heat.

JP 2008-201664 A International Publication No. 2012/074054 Pamphlet JP 2001-220118 A

  An object of the present invention is to provide a method for producing activated carbon which can obtain activated carbon having a low metal content useful as an electrode active material of a capacitor without activating complicated washing by activating particulate carbide of cellulose acetate. It is to provide.

  As a result of research by the inventors of the present invention, if the heat-resistant cylindrical body provided in the activation device using the rotary kiln is made of a metal material, the heat-resistant cylindrical body that has become a high temperature (for example, 750 to 1100 ° C.) upon activation. It has been found that a small amount of metal vapor generated from the inner surface of the metal is taken into the carbide (or activated carbon) in contact with the inner surface of the heat-resistant cylinder and increases the metal content of the activated carbon. Further, the carbide may be rubbed against the metal surface and the metal may be mixed. For this reason, it examined about forming the inner surface of a heat-resistant cylindrical body from the ceramic material represented by quartz glass. This is because even if the ceramic material contains a metal in the form of its oxide or nitride, metal vapor is hardly generated in the temperature range where the carbide is heated during activation.

  However, for example, even when activated carbon is produced by activating the carbide of cellulose acetate using a quartz glass heat-resistant cylinder, the metal content of the obtained activated carbon, for example, the iron content is reduced to about 50 ppm. However, it is not always sufficient when considering use as an electrode active material of a capacitor.

  As a result of further research by the inventors of the present invention, the following has been found. Since the hood attached to each of both ends of the heat-resistant cylindrical body of the rotary kiln is easy to manufacture, the hood is generally formed of a metal material typified by steel. The hood is not heated to such a high temperature that metal vapor is generated. However, in the inside of the heat-resistant cylindrical body heated to a high temperature during activation, the vapor of acetic acid remaining in the particulate carbide of cellulose acetate, and particularly when using water vapor as the activation gas, the water vapor In contact, the metal material of the hood is corroded. In the case of a cellulose acetate film containing a phosphate compound as a plasticizer, corrosion is particularly significant. For this reason, the metal oxide produced | generated by corrosion adheres to the inner surface of the hood. And the activated particulate carbide (that is, activated carbon) activated inside the heat-resistant cylindrical body and discharged through the discharge passage provided in the hood includes the periphery of the discharge passage of the hood and its opening. When contacting the surface region, the metal oxide adhering to the inner surface of the hood is taken in at that time, and as a result, the metal content of the activated carbon is increased.

  Accordingly, the present invention provides a heat-resistant cylindrical body, a hood provided on each of both end portions of the heat-resistant cylindrical body, a hood for rotatably supporting the heat-resistant cylindrical body, and a cellulose acetate particulate provided on one of the hoods. Particulate carbide of cellulose acetate supplied through the supply port to the heat-resistant cylindrical body of the externally heated rotary kiln including the carbide supply port and the activated particulate carbide discharge passage provided in the other hood Is activated by heating in the presence of an activation gas, and then the activated particulate carbide is discharged through the discharge passage. Carbide activation is performed using water vapor as the activation gas and a heat-resistant cylindrical body having at least an inner surface formed of a ceramic material as the heat-resistant cylindrical body. And the discharge of the activated particulate carbide, the hood having a surface region including at least the discharge passage of the activated particulate carbide and the periphery of the discharge port as a hood. It is in the manufacturing method of activated carbon characterized by using.

The preferable aspect of the manufacturing method of the activated carbon of this invention is as follows.
(1) The heat resistant cylindrical body is made of quartz glass.
(2) The hood provided with the exhaust passage of the activated particulate carbide is a hood provided with a thermal sprayed ceramic material layer on the inner surface.

(3) The cellulose carbide particulate carbide supply port is provided at the tip of the carbide supply pipe that penetrates the hood.
(4) At least the outer peripheral surface around the tip of the carbide supply pipe on the heat resistant cylindrical body side is formed of a ceramic material.

(5) The inner surface of the hood through which the carbide supply pipe passes is made of a ceramic material.
(6) A steam supply port is provided in a hood having a discharge passage for activated particulate carbide.

(7) On the inner peripheral surface of the heat-resistant cylindrical body, there are provided protrusions extending in the lengthwise direction that enable stirring of the particulate carbide of cellulose acetate under activation when the heat-resistant cylindrical body rotates. .
(8) The protrusion is inclined with respect to the radial direction of the heat-resistant cylindrical body, and the tip end portion of the protrusion is disposed on the front side in the rotational direction of the heat-resistant cylindrical body with respect to the base portion.

  By activating the particulate carbide of cellulose acetate according to the method of the present invention, activated carbon having a low metal content that can be used as an electrode active material of a capacitor can be produced without complicated cleaning.

It is a figure which shows the structural example of the rotary kiln (activation apparatus) which can be used advantageously when enforcing the manufacturing method of the activated carbon of this invention. It is sectional drawing which shows another structural example of the heat resistant cylindrical body with which a rotary kiln is provided.

  First, the structural example of the rotary kiln (activation device) which can be used advantageously when implementing the manufacturing method of the activated carbon of this invention is demonstrated using attached drawing. FIG. 1 is a diagram illustrating a configuration example of a rotary kiln.

  A rotary kiln 10 shown in FIG. 1 is an externally heated rotary kiln for obtaining activated carbon 12 by activation by heating particulate carbide 11 of cellulose acetate in the presence of an activation gas.

  Cellulose acetate particulate carbide is a particulate carbide using cellulose acetate as a starting material. The cellulose acetate is carbonized by heating, and the resulting cellulose acetate carbide is crushed (or pulverized) into particles. It is obtained by processing into a shape. The “particulate carbide” means a carbide containing particles having a maximum diameter of 10 mm or less.

  Methods for obtaining cellulose acetate carbide are described in, for example, the above-mentioned publications of Patent Document 1 and Patent Document 2.

  A rotary kiln (activation device) 10 includes a heat-resistant cylindrical body 13 and hoods 14 and 15 that are respectively provided at both ends of the heat-resistant cylindrical body 13 and rotatably support the heat-resistant cylindrical body 13. This is an externally heated rotary kiln including a supply port 16 for particulate carbide 11 of cellulose acetate provided and a discharge passage 17 for activated particulate carbide (ie activated carbon) 12 provided in the other hood 15.

  At least the inner surface of the heat-resistant cylindrical body 13 is formed of a ceramic material, and the surface region including at least the discharge passage 17 of the particulate carbide 12 that has been activated in the hood 15 and the periphery of the discharge port 17a is ceramic. Formed from material.

  The heat resistant cylindrical body 13 shown in FIG. 1 is made of quartz glass. Thus, the inner surface of the heat-resistant cylindrical body 13 is formed from a ceramic material (quartz glass).

  Hoods 14 and 15 are provided at both ends of the heat-resistant cylindrical body 13. These hoods 14 and 15 rotatably support the heat-resistant cylindrical body 13.

  One hood 14 is provided with a supply port 16 for particulate carbide 11 of cellulose acetate. The supply port 16 is provided at the tip of a carbide supply pipe 21 that penetrates the hood 14.

  The other hood 15 is provided with a discharge passage 17 for the activated particulate carbide (that is, activated carbon) 12. The discharge passage 17 includes a discharge port 17a.

  As the hood 15, a hood having a sprayed ceramic material layer 19 on the inner surface is used. The hood 15 is composed of a base 15a made of a metal material and the sprayed ceramic material layer 19. The thermal spraying ceramic material layer 19 is made of zirconium oxide (zirconia). As described above, the surface region including the periphery of the discharge passage 17 of the particulate carbide 12 subjected to the activation treatment of the hood 15 and the discharge port 17a thereof is formed of a ceramic material (zirconium oxide).

  The “external heat type rotary kiln” means a rotary kiln equipped with a heating tool outside (preferably around) the heat resistant cylindrical body.

  Next, the manufacturing method of the activated carbon of this invention is demonstrated by using the case where the rotary kiln 10 shown in FIG. 1 is used as a representative example.

  The method for producing activated carbon according to the present invention includes a heat-resistant cylindrical body 13 and hoods 14 and 15 that are respectively provided at both ends of the heat-resistant cylindrical body 13 and rotatably support the heat-resistant cylindrical body 13. In the heat-resistant cylindrical body 13 of the externally heated rotary kiln 10 including the supply port 16 for the particulate carbide 11 of the cellulose acetate provided and the discharge passage 17 for the activated particulate carbide 12 provided in the other hood. The cellulose acetate particulate carbide 11 supplied through the supply port 16 is activated by heating in the presence of an activation gas, and then the activated particulate carbide 12 is discharged through the discharge passage 17. This is a manufacturing method.

  In this manufacturing method, activation of the particulate carbide 11 of cellulose acetate is performed by using water vapor as the activation gas, and a heat resistant cylindrical body having at least an inner surface formed of a ceramic material as the heat resistant cylindrical body 13. The surface region including at least the discharge passage 17 of the particulate carbide 12 that has been activated and the periphery of the discharge port 17a as the hood 15 is ceramic. It is characterized by using a hood formed from a material.

  The inner surface of the heat-resistant cylindrical body 13 of the rotary kiln 10 used in the manufacturing method of the present invention is formed from a ceramic material (quartz glass). For this reason, a metal is not taken in into the particulate carbide of cellulose acetate or the activated particulate carbide (activated carbon) through contact with the inner surface of the heat-resistant cylindrical body 13.

  Moreover, the surface area | region including the circumference | surroundings of the discharge channel | path 17 and the discharge port 17a of the activated carbonized particulate carbide 12 of the food | hood 15 of the rotary kiln 10 is formed from the ceramic material (zirconium oxide). Therefore, vapor such as acetic acid remaining in the particulate carbide of cellulose acetate, or water vapor used as an activation gas, generated inside the heat-resistant cylindrical body 13 heated to a high temperature during activation, contacts the surface region. However, no metal oxide is generated in this surface region. For this reason, a metal oxide is not taken in into the activated particulate carbide (activated carbon) through contact with the surface region.

  Therefore, by carrying out the method of the present invention, activated carbon having a low metal content can be produced from the particulate carbide of cellulose acetate. Since the obtained activated carbon has a low metal content, it can be advantageously used as an electrode active material of a capacitor without performing a complicated operation such as further washing.

  Below, the preferable embodiment of the manufacturing method of this invention is demonstrated in detail by using the case where the rotary kiln 10 shown in FIG. 1 is used as a representative example.

  The form of cellulose acetate used as a starting material for the particulate carbide 11 of cellulose acetate is not particularly limited, but is generally in the form of a film or fiber.

  Cellulose acetate preferably has a substitution degree of acetic acid in the range of 2 to 3. The cellulose acetate is preferably cellulose mainly composed of triacetyl cellulose. Cellulose acetate may contain additives such as a plasticizer. As the starting material of the particulate carbide activated by the activation device of the present invention, cellulose acetate described in each of the above-mentioned Patent Document 1 and Patent Document 2 can be used. The effect of the present invention is remarkable in the activation of carbide using cellulose acetate containing a phosphate ester plasticizer as a raw material.

  The carbide of cellulose acetate can be obtained, for example, by heating cellulose acetate in an inert gas. Carbonization of cellulose acetate can be carried out, for example, using the methods described in Patent Document 1 and Patent Document 2.

  By crushing (pulverizing) the carbide of cellulose acetate, a particulate carbide of cellulose acetate is obtained. Various mills can be used for crushing, for example.

  If the carbonized carbide of cellulose acetate is preliminarily formed into particles, the particulate carbide 11 can be activated with sufficient stirring inside the heat-resistant cylindrical body 13, so that the carbide is crushed after activation. Thus, activated carbon having a stable quality (eg, specific surface area) can be obtained.

  The particulate carbide of cellulose acetate is put into the hopper 31. A fixed amount of particulate carbide is sent to the bucket conveyor 33 by a rotary valve 32 provided at the bottom of the hopper 31.

  The particulate carbide transported by the bucket conveyor 33 falls to a portion between the valves 34 and 35 of the connection pipe 36 in a state where the butterfly valve 35 is closed and the butterfly valve 34 is opened. At this time, nitrogen gas is fed into a portion of the connection pipe 36 between the valves 34 and 35 via the pipe body 37. In this state, by closing the valve 34 and then opening the valve 35, particulate carbide can be introduced into the silo 38 in a state where the inflow of air into the silo 38 is suppressed.

  Nitrogen gas is fed into the silo 38 via the tube 38a. The air inside the silo 38 is discharged to the outside through the pipe body 38b together with the nitrogen gas. Thereby, the inside of the silo 38 is filled with nitrogen gas. For this reason, when supplying particulate carbide to the inside of the heat-resistant cylindrical body 13, it becomes difficult for air to flow in with this particulate carbide. Therefore, rapid oxidation of the particulate carbide inside the heat-resistant cylindrical body 13 can be suppressed (or combustion can be prevented).

  The particulate carbide charged into the silo 38 is supplied into the heat-resistant cylindrical body 13 from the supply port 16 at the tip of the carbide supply pipe 21 provided at the bottom of the silo 38. Inside the carbide supply pipe 21, a screw (not shown) for sending particulate carbide is provided.

  It is preferable that at least the outer peripheral surface around the tip of the carbide supply pipe on the heat resistant cylindrical body side is formed of a ceramic material. The carbide supply pipe is preferably a carbide supply pipe having a ceramic material layer on the outer peripheral surface. As shown in FIG. 1, the carbide supply pipe 21 is more preferably a carbide supply pipe including a sprayed ceramic material layer 39 on the outer peripheral surface. The carbide supply tube may be made of quartz glass (or a ceramic material other than quartz glass).

  The portion of the carbide supply pipe closer to the heat-resistant cylindrical body 13 than the hood 14 need not be in a tubular shape. For example, a member having a groove serving as a particulate carbide passage may be used as the portion of the carbide supply pipe closer to the heat-resistant cylindrical body 13 than the hood 14. In this case, the “particulate carbide supply port of cellulose acetate” corresponds to an opening formed in the hood 14 for supplying the particulate carbide to the groove.

  The heat resistant cylinder 13 is made of quartz glass. As the heat-resistant cylindrical body, for example, a heat-resistant cylindrical body made of a ceramic material or a heat-resistant cylindrical body having a ceramic material layer on the inner surface can be used.

  The ceramic material layer is particularly preferably a sprayed ceramic material layer formed by spraying a ceramic material.

  A well-known thermal spraying method can be used for forming the thermal spraying ceramic material layer. Typical examples of the thermal spraying method include gas spraying, flame spraying, and arc spraying.

  The thickness of the thermally sprayed ceramic material layer is generally set in the range of 10 to 500 μm, preferably in the range of 100 to 200 μm.

Typical examples of the ceramic material include zirconium oxide (Zr ₂ O), aluminum oxide (Al ₂ O ₃ ), and spinel (MgAl ₂ O ₄ ).

  Flange 41 and 42 are provided on the outer peripheral surface of the heat-resistant cylindrical body 13. Protective covers 43 and 44 are attached to the flanges 41 and 42, respectively. The flanges 41 and 42 are each made of quartz glass, and the protective covers 43 and 44 are each made of a metal material (typical example, steel).

  The quartz glass flanges 41 and 42 and the protective covers 43 and 44 made of a metal material have mutually different values of thermal expansion coefficient. In order to prevent the flanges 41 and 42 from being damaged due to stress generated during thermal expansion, protective covers 43 and 44 are attached to the flanges 41 and 42 via, for example, Teflon sheets (not shown). ing.

  The flange 41 is provided with two rollers 45 arranged side by side along the circumferential direction of the heat-resistant cylindrical body 13 with a protective cover 43 (one of which is arranged on the front side of the sheet of FIG. 1). Is supported by). Similarly, the flange 42 is supported by two rollers 46 arranged side by side along the circumferential direction of the heat-resistant cylindrical body 13 via the protective cover 44. The heat-resistant cylindrical body 13 is rotatably supported by four rollers in total.

  A flange 47 different from the above is provided on the outer peripheral surface of the heat-resistant cylindrical body 13. A sprocket 48 is attached to the flange 47. The sprocket 48 is connected to the rotation drive device 51 via a chain 49.

  Therefore, by operating the rotation driving device 51, the heat-resistant cylindrical body 13 supported by the rollers 45 and 46 together with the sprocket 48 can be rotated in the circumferential direction.

  The rotational speed of the heat-resistant cylindrical body 13 is usually set within a range of 0.01 to 10 rpm, preferably 0.1 to 5 rpm, particularly preferably 0.1 to 3 rpm.

  The heat-resistant cylindrical body 13 is installed on the base 73 via the rollers 45 and 46 described above. The base 73 can be inclined and moved around a shaft 74 provided on the lower surface thereof. When the jack 75 is operated and one end of the base 73 is raised, the heat-resistant cylindrical body 13 supported by the base 73 can be disposed in an inclined state. Thereby, the particulate carbide supplied to the inside of the heat-resistant cylindrical body 13 rotating as described above moves toward the hood 15 provided with the discharge passage 17.

  The inclination angle of the heat-resistant cylindrical body 13 is usually 1 degree or less, preferably 0.001 to 0.5 degree, more preferably 0.005 to 0.2 degree, and particularly preferably 0.005 to 0.1 degree. Is set within the range.

  By adjusting the inclination angle of the heat-resistant cylindrical body 13, the time for activating the particulate carbide is generally set in the range of 10 minutes to 10 hours, preferably in the range of 30 minutes to 5 hours.

  A heating tool 52 is installed around the heat-resistant cylindrical body 13. As the heating tool, for example, a resistance heating type heater or a high frequency induction heating type heater can be used.

  The temperature inside the heat-resistant cylindrical body 13 is generally set in the range of 750 to 1100 ° C., preferably in the range of 850 to 1100 ° C., by the heating tool 52.

  The heat-resistant cylindrical body 13 is rotatably supported by hoods 14 and 15 provided at both ends. Each of the hoods 14 and 15 is attached to each of both ends of the heat-resistant cylindrical body 13 without rotating in the circumferential direction. In order to rotatably support the heat-resistant cylinder 13, an annular packing (not shown) made of silicone rubber is provided between the heat-resistant cylinder 13 and each hood.

  The surface region including at least the discharge passage 17 of the particulate carbide 12 that has been activated and the periphery of the discharge port 17a of the hood 15 is formed of a ceramic material. The hood 15 provided with the discharge passage 17 for the activated particulate carbide 12 is preferably a hood provided with a ceramic material layer, particularly preferably a thermal sprayed ceramic material layer 19 on the inner surface. The hood may be made of quartz glass (or a ceramic material other than quartz glass).

  The inner surface of the hood 14 through which the carbide supply pipe 21 penetrates is preferably formed from a ceramic material. More preferably, the hood 14 is a hood provided with a ceramic material layer, particularly preferably a sprayed ceramic material layer, on the inner surface. The hood may also be made of quartz glass (or a ceramic material other than quartz glass).

  The food | hoods 14 and 15 are installed on the trolley | bogies 53 and 54, respectively. The hoods 14 and 15 can be moved along the rails 55 and 56 together with the carriages 53 and 54 (along the length direction of the heat-resistant cylindrical body). Thereby, when assembling the activation device 10 or when performing maintenance and inspection, the hoods 14 and 15 can be moved to the opposite side to the heat-resistant cylindrical body 13 and can be detached from the heat-resistant cylindrical body 13. ing.

  It is preferable that the food | hood 15 which has the discharge channel | path 17 of said activated carbonized particulate carbide | carbonized_material 12 is provided with the supply port 18 of water vapor | steam (activation gas). In this case, an exhaust duct 57 is connected to the hood 14 having the supply port 16 of particulate carbide of cellulose acetate. The exhaust duct 57 is provided with a butterfly valve 57a. Due to the degree of opening of the valve 57a, the inside of the heat-resistant cylindrical body 13 is adjusted to a pressure higher than the atmospheric pressure. Thereby, the inflow of air from the exhaust duct 57 into the heat-resistant cylindrical body 13 is suppressed. The activation gas supply port may be provided in the hood 14 having the cellulose acetate particulate carbide supply port 16.

  It is preferable that the hood 15 is further provided with an inert gas supply port 20. By supplying an inert gas from the supply port 20, rapid oxidation of the particulate carbide inside the heat-resistant cylindrical body 13 can be suppressed (or combustion can be prevented). The inert gas includes nitrogen gas in addition to a rare gas typified by argon gas or neon gas. Nitrogen gas is particularly preferably used as the inert gas.

  The hood 15 is connected via a connecting pipe 58 to a pipe body 59 for cooling the activated carbide (that is, activated carbon). Inside the tube body 59, a screw (not shown) for delivering particulate carbide is provided.

  Nitrogen gas is fed into the activated carbon passage (space around the screw) inside the tube 59 via the tubes 71 and 72. The nitrogen gas is discharged to the outside through the connection pipe 58, the hood 15, the heat-resistant cylindrical body 13, the hood 14, and the exhaust duct 57.

  The screw is provided with a cooling water passage on the central axis thereof, and can be cooled with water. Cooling water is supplied to the passage of the screw by the pipe body 61, and cooling water is discharged from the passage of the screw by the pipe body 62.

  Further, a water-cooled cooler 63 is provided around the tube body 59. Cooling water is supplied into the cooler 63 by the pipe body 64, and cooling water is discharged from the cooler 63 by the pipe body 65.

  Activated carbon (particulate carbide that has been activated) that has been cooled in the pipe body 59 is closed between the valves 66 and 67 of the activated carbon discharge pipe 68 with the butterfly valve 67 closed and the butterfly valve 66 open. Fall to the site. At this time, nitrogen gas is fed into the portion between the valves 66 and 67 of the activated carbon discharge pipe 68 through the pipe body 69. In this state, the particulate carbide can be discharged by closing the valve 66 and then opening the valve 67. Thereby, the inflow of air into the heat-resistant cylindrical body 13 through the activated carbon discharge pipe 68, the pipe body 59, the connection pipe 58, and the hood 15 can be suppressed.

  FIG. 2 is a cross-sectional view illustrating another configuration example of the heat-resistant cylindrical body included in the rotary kiln. An arrow 84 written in FIG. 2 indicates the rotation direction of the heat-resistant cylindrical body 83.

  On the inner peripheral surface of the heat resistant cylindrical body 83 shown in FIG. 2, the particulate carbide of cellulose acetate under activation is allowed to be stirred when the heat resistant cylindrical body 83 is rotated. ) Protrusions 85 and 86 extending in the length direction are provided.

  When the heat-resistant cylindrical body 83 rotates, the particulate carbide 11 supplied into the heat-resistant cylindrical body 83 is accommodated in a space between the peripheral wall of the heat-resistant cylindrical body 83 and the protrusion 85 or the protrusion 86, After being transported to a position above the heat-resistant cylindrical body 83, it falls to the bottom of the heat-resistant cylindrical body 83. Thereby, since the particulate carbide | carbonized_material 11 is activated, fully stirring in the inside of the heat resistant cylindrical body 83, the activated carbon of the stable quality (for example, specific surface area) is obtained.

  As shown in FIG. 2, each protrusion, for example, the protrusion 86 is inclined with respect to the radial direction of the heat resistant cylindrical body 83, and the distal end portion 86 a of the protrusion 86 is formed on the heat resistant cylindrical body 83 more than the base portion 86 b. It is preferable to be arranged on the front side in the rotation direction (direction indicated by arrow 84).

  If the angle (acute angle) θ formed between each protrusion and the radial direction of the heat-resistant cylindrical body 83 is too small, the particulate carbide 11 is heat-resistant before being carried to a sufficiently upper position inside the heat-resistant cylindrical body 83. Drops to the bottom of the conductive cylinder 83. On the other hand, if the angle θ is too large, the amount of particulate carbide carried to the upper position inside the heat-resistant cylindrical body 83 is reduced.

  The angle (acute angle) θ formed between each protrusion and the radial direction of the heat-resistant cylindrical body 83 is preferably in the range of 5 to 70 degrees, more preferably in the range of 10 to 60 degrees, and 20 to It is particularly preferable to be within the range of 50 degrees.

[Example 1]
The activated carbon was manufactured by activating the particulate carbide (iron content: 10 ppm or less) produced from the cellulose acetate film as follows using the activation apparatus 10 shown in FIG.

  The activation device 10 shown in FIG. 1 has a heat-resistant cylindrical body 13 made of quartz glass, a carbide supply pipe 21 provided with a thermal spray ceramic material layer (zirconium oxide layer) 39 on the outer peripheral surface, and a thermal spray ceramic material layer on each inner surface. Hoods 14 and 15 having (zirconium oxide layer) 19 are used.

  First, the angle of the heat-resistant cylindrical body 13 was set to 0.01 degree using the jack 75 of the activation device 10. Next, the heating tool 52 was operated and the temperature inside the heat-resistant cylindrical body 13 was set to 950 ° C. The heat-resistant cylindrical body 13 was rotated at a speed of 1 rpm by operating the rotation driving device 51. Water vapor was supplied to the water vapor supply port 18 and nitrogen gas was supplied to the inert gas supply port 20.

  Subsequently, the cellulose carbide particulate carbide was continuously charged into the hopper 31 of the activation device 10, and the particulate carbide was supplied into the heat-resistant cylindrical body 13 through the supply port 16 of the carbide supply pipe 21. Cellulose acetate particulate carbide 11 was activated in the heat-resistant cylindrical body 13 by heating in the presence of water vapor. The activated particulate carbide (activated carbon) 12 was cooled inside the tube 59 and then taken out from the opening at the lower end of the activated carbon discharge pipe 68. Thus, activated carbon was manufactured by activating the particulate carbide of cellulose acetate.

The activated carbon produced had a BET specific surface area of 2104 m ² / g and an iron content of 12 ppm.

10 Rotary kiln (activation device)
11 Cellulose acetate particulate carbide 12 Activated particulate carbide (activated carbon)
13 Heat Resistant Cylindrical Body 14, 15 Hood 15a Base 16 Cellulose Acetate Particulate Carbide Supply Port 17 Activation Passage Particulate Carbide Discharge Passage 17a Discharge Port 18 Activated Gas Supply Port (Water Vapor Supply Port)
DESCRIPTION OF SYMBOLS 19 Thermal spray ceramic material layer 20 Inert gas supply port 21 Carbide supply pipe 31 Hopper 32 Rotary valve 33 Bucket conveyor 34, 35 Butterfly valve 36 Connection pipe 37 Tubing body 38 Silos 38a, 38b Tubing body 39 Thermal spraying ceramic material layer 41, 42 Flange 43, 44 Protective cover 45, 46 Roller 47 Flange 48 Sprocket 49 Chain 51 Rotation drive device 52 Heating tool 53, 54 Carriage 55, 56 Rail 57 Exhaust duct 57a Butterfly valve 58 Connection pipe 59 Pipe body 61, 62 Pipe body 63 Cooler 64, 65 Tubing 66, 67 Butterfly valve 68 Activated carbon discharge pipe 69 Tubing 71, 72 Tubing 73 Base 74 Shaft 75 Jack 83 Heat-resistant cylindrical body 84 Arrows 85, 86 Projection indicating the rotational direction of the heat-resistant cylindrical body 86a Protrusion tip 86b Protrusion base

Claims (9)

A heat-resistant cylindrical body, a hood provided on each of both ends of the heat-resistant cylindrical body for rotatably supporting the heat-resistant cylindrical body, and a cellulose carbide particulate carbide supply port provided on one side of the hood The particulate carbide of cellulose acetate supplied through the supply port to the heat-resistant cylindrical body of the externally heated rotary kiln including the exhaust passage of the activated particulate carbide provided in the other hood is activated gas. It is activated by heating in the presence of the following, and then activated carbonized particulate carbide is discharged through the discharge passage, the activated carbon production method comprising:
Activation of the particulate carbide of cellulose acetate is performed using water vapor as the activation gas, and using a heat-resistant cylinder having at least an inner surface formed of a ceramic material as the heat-resistant cylinder, and The activated particulate treated carbide is discharged using a hood in which at least the activated particulate particulate carbide discharge passage and the surface area including the periphery of the outlet are formed of a ceramic material as the hood. A method for producing activated charcoal.   The method according to claim 1, wherein the heat-resistant cylinder is made of quartz glass.   The method according to claim 1 or 2, wherein the hood provided with the activated particulate carbide discharge passage is a hood provided with a thermal sprayed ceramic material layer on the inner surface.   The method according to any one of claims 1 to 3, wherein a cellulose carbide particulate carbide supply port is provided at a tip of a carbide supply pipe penetrating the hood.   The method according to claim 4, wherein at least an outer peripheral surface around a tip portion of the carbide supply pipe on a heat resistant cylindrical body side is formed of a ceramic material.   6. A method according to claim 4 or 5, wherein the inner surface of the hood through which the carbide supply tube passes is formed from a ceramic material.   The method as described in any one of Claims 1 thru | or 6 with which the supply port of the water vapor | steam is provided in the hood which has the discharge passage of the activated particulate carbide.   2. A protrusion extending in a length direction is provided on an inner peripheral surface of the heat resistant cylindrical body, which enables the stirring of the activated carbon acetate particulate carbide during rotation of the heat resistant cylindrical body. The method as described in any one of thru | or 7.   The method according to claim 8, wherein the protrusion is inclined with respect to the radial direction of the heat-resistant cylindrical body, and the tip end portion of the protrusion is disposed on the front side in the rotational direction of the heat-resistant cylindrical body with respect to the base portion.

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