JP2011001232A - Method for producing activated carbon, and electric double layer capacitor using activated carbon obtained by the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing activated carbon, by which the physical properties of obtained activated carbon are highly controlled without performing a pretreatment of a carbon raw material.SOLUTION: The method for producing activated carbon is characterized in that a carbon raw material and an organic compound having a melting point of ≤250°C are mixed, and then are subjected to alkali activation.

Description

  The present invention relates to a method for producing activated carbon, and more particularly to a technique for controlling the pore structure of activated carbon after activation.

  Conventionally, activated carbon has been widely used as an electrode and an adsorbent for electric double layer capacitors because of its excellent adsorption ability. In order to function effectively in such applications, the activated carbon is required to have appropriate physical properties (for example, specific surface area, pore diameter, etc.). Here, it is known that the physical properties such as the specific surface area of the activated carbon obtained by the activation treatment are greatly influenced by the structure of the carbon raw material used as the activation raw material. Therefore, in general, in order to control the physical properties of the activated carbon to a higher degree, pretreatment such as heat treatment is performed on the carbon raw material to be used.

  As a method for producing such activated carbon, for example, Patent Document 1 discloses that it is derived from one or more substances selected from coal-based heavy oil, petroleum-based heavy oil, and tar oil obtained by heat treatment of a resin. A method for producing an electrode active material for an electric double layer capacitor is disclosed, wherein an extraction residue obtained by extracting coke with an organic solvent is used as an electrode active material (Patent Documents 1 and 1). .

  Although not a method for producing activated carbon, for example, Patent Document 2 discloses that raw material coal is mixed with N-methyl-2-pyrrolidone solvent alone or a mixed solvent of carbon disulfide and N-methyl-2-pyrrolidone with chlorine or a fluorine compound. There is disclosed a method for producing ashless coal, characterized in that the ashless coal in the raw coal is extracted into the solvent by contacting in the presence of (Patent Document 2, Claim 1).

JP 2008-135587 A Japanese Patent No. 3198305

  Conventionally, in order to control the physical properties of activated carbon, pretreatment such as heat treatment has been performed on the carbon raw material to be used. However, when such a carbon raw material is pretreated, the cost and time for the pretreatment process increase, resulting in a problem that the productivity of the entire production process is lowered.

  This invention is made | formed in view of the said situation, Comprising: It aims at providing the manufacturing method of the activated carbon which can control the physical property of the activated carbon obtained highly, without performing the pre-processing of a carbon raw material.

  Conventionally, an organic compound having a melting point of 250 ° C. or lower has a low boiling point, and is volatilized before reaching an activation temperature (about 600 ° C. when metallic potassium is used), and it has been considered that the activation reaction is not affected. Therefore, use of such an organic compound having a low boiling point as an activation raw material has not been studied. As a result of various studies on methods capable of highly controlling the physical properties of the activated carbon, the inventors of the present invention have highly enhanced the physical properties of the obtained activated carbon by mixing the carbon raw material with an organic compound having a melting point of 250 ° C. or less and activating the alkali. The inventors have found that it can be controlled and have come up with the present invention.

  That is, the method for producing activated carbon of the present invention that has solved the above-mentioned problems is characterized by alkali activation after mixing a carbon raw material and an organic compound having a melting point of 250 ° C. or lower. By mixing the organic compound, the physical properties of the obtained activated carbon can be controlled to a higher degree than simply adjusting the activation time or the amount of the alkali activator used. The reason why the properties of the obtained activated carbon can be highly controlled by mixing the organic compound with the carbon raw material is considered to be because the carbon raw material is modified by the organic compound in the temperature rising process.

  The mixing of the carbon raw material and the organic compound is preferably performed at a temperature equal to or higher than the melting point of the organic compound. The organic compound is preferably a heterocyclic compound or an aromatic hydrocarbon. The mass ratio of the organic compound to the carbon raw material (organic compound / carbon raw material) is preferably 0.05 or more and 10 or less.

  The carbon raw material includes at least one selected from the group consisting of coal pitch coke, coal, petroleum coke, coal coke, petroleum pitch coke, synthetic resin, composite of synthetic resin and cellulosic fiber, and carbides thereof. It is preferable to use it.

  The present invention also includes an electric double layer capacitor in which the activated carbon obtained by the above production method is used as an electrode constituent material.

  According to the present invention, it is possible to highly control the physical properties of the obtained activated carbon without performing pretreatment of the carbon raw material.

It is a figure which shows the pore diameter distribution of the activated carbon obtained by manufacture example 1-4,7. It is a figure which shows the pore size distribution of the activated carbon obtained by manufacture example 5, 6, 8, 9.

  The method for producing activated carbon of the present invention is characterized in that alkali activation is performed after mixing a carbon raw material and an organic compound having a melting point of 250 ° C. or lower.

  In the production method of the present invention, the reason why the properties of the activated carbon can be controlled to a high degree by mixing an organic compound with the carbon raw material is not necessarily clear, but it is considered that the carbon raw material is modified by the organic compound. For example, when coal pitch coke is used as the carbon raw material, at the time of mixing with the organic compound, at least a part of the carbon precursor components (pyrene, naphthacene, perylene, etc.) contained in the coal pitch coke is converted into the liquid organic compound. An infinite number of holes are formed on the surface of the resulting solid residue after elution and the carbon precursor component has escaped. By forming innumerable holes in this manner, the number of points active on the activation reaction (for example, edge surfaces) increases on the surface, so that the increase in average pore diameter is suppressed while increasing the specific surface area. it is conceivable that.

  In addition, when a resin is used as the carbon raw material, it is considered that by adding a solvent, the bonding portion of the polymer constituting the resin is easily cut and the carbon structure formed by activation is changed. When resin carbide is used as the carbon raw material, it is considered that by adding a solvent, a component that is easily eluted in the resin carbide is eluted into the solvent, thereby changing the carbon structure formed by activation.

  Hereinafter, the manufacturing method of the activated carbon of this invention is demonstrated in detail. The production method of the present invention comprises a mixing step of mixing a carbon raw material, an organic compound having a melting point of 250 ° C. or lower (hereinafter sometimes simply referred to as “organic compound”) and an alkali activator; an alkali for heating the resulting mixture An activation step in this order.

  In the mixing step, a carbon raw material, an organic compound having a melting point of 250 ° C. or less, and an alkali activator are mixed. The mixing is preferably performed at a temperature equal to or higher than the melting point temperature of the organic compound. The mixing may be performed before being introduced into the furnace, or each raw material may be separately introduced into the furnace and mixed in the furnace.

  Examples of the carbon raw material include wood, sawdust, coconut shell, cellulosic fiber (including paper), synthetic resin (eg, phenol resin, polyvinyl chloride, polyimide, polyacrylonitrile (PAN)), petroleum pitch, coal tar pitch, Carbonaceous materials such as mesophase pitch and composites thereof; carbides of the carbonaceous materials; carbides such as coal, petroleum coke, coal coke, petroleum pitch coke, coal pitch coke, and charcoal. These carbon raw materials may be used alone or in combination of two or more. Among these, the carbon raw material is at least selected from the group consisting of coal pitch coke, coal, petroleum coke, coal coke, petroleum pitch coke, synthetic resin, composite of synthetic resin and cellulosic fiber, and carbides thereof. One is preferred.

  When the carbonaceous material is used as a carbide, carbonization of the carbonaceous material is usually performed by heat treatment in an inert gas atmosphere. The temperature of the carbonization treatment is preferably 400 ° C. or higher, more preferably 500 ° C. or higher, preferably 950 ° C. or lower, more preferably 900 ° C. or lower. Further, the carbonization time is preferably 0.5 hours or longer, more preferably 1.0 hours or longer, 4.0 hours or shorter, more preferably 3.0 hours or shorter.

  The carbon raw material preferably has an average particle size of 10 mm or less, more preferably 5 mm or less, and even more preferably 2 mm or less. If the average particle diameter of the carbide is 10 mm or less, the specific surface area of the carbide can be increased, and the surface modification effect of the carbon raw material by the organic compound is further improved. The lower limit of the average particle size of the carbon raw material is not particularly limited, but if the average particle size is too small, the handling of the powder tends to be poor (for example, the powder will rise during operation). Therefore, the average particle diameter of the carbon raw material is preferably 1 μm or more, more preferably 3 μm or more, and further preferably 5 μm or more. The average particle diameter is a volume average particle obtained by measuring a sample dispersed in water with a laser diffraction particle size distribution measuring apparatus (for example, “SALD (registered trademark) -2000” manufactured by Shimadzu Corporation). Is the diameter.

  The organic compound having a melting point of 250 ° C. or lower used in the present invention is liquid at room temperature (20 ° C.), or is solid at room temperature (20 ° C.) but melts in the process of raising the temperature to the activation treatment temperature. Is. Moreover, since the effect which controls the pore diameter of the activated carbon obtained becomes larger, the melting point of the organic compound is preferably 40 ° C. or lower, more preferably 20 ° C. or lower. That is, it is preferable to use a so-called organic solvent as the organic compound. The boiling point of the organic compound is preferably 60 ° C. or higher, more preferably 100 ° C. or higher, and further preferably 200 ° C. or higher. The boiling points of typical organic compounds are, for example, tetrahydrofuran: 66 ° C., toluene: 110.6 ° C., and N-methyl-2-pyrrolidone: 202 ° C.

  Examples of the organic compound include heterocyclic compounds such as N-methyl-2-pyrrolidone, quinoline, pyridine, tetrahydrofuran, pyrazine, quinoxaline, and acridine; benzene, toluene, xylene, mesitylene, pyrene, chrysene, perylene, and the like. Aromatic hydrocarbons; aliphatic hydrocarbons such as hexane, heptane and cyclohexane; halogenated aliphatic hydrocarbons such as chloroform and dichloroethane; ketones such as acetone and methyl ethyl ketone; esters such as ethyl acetate; methanol, ethanol and propanol Alcohol; and the like. These organic compounds may be used alone or in combination of two or more. Among these, a heterocyclic compound and an aromatic hydrocarbon are preferable, and at least one selected from the group consisting of N-methyl-2-pyrrolidone, toluene, and tetrahydrofuran is more preferable.

  The mass ratio of the carbon raw material to the organic compound (organic compound / carbon raw material) is preferably 0.05 or more, more preferably 0.5 or more, still more preferably 1.0 or more, and particularly preferably 2.0 or more. Yes, preferably 10 or less, more preferably 5.0 or less, and still more preferably 3.0 or less. When the mass ratio (organic compound / carbon raw material) is 0.05 or more, the specific surface area of the obtained activated carbon is increased or the pore size distribution is larger or smaller than when no organic compound is used. If the effect of shifting to a larger value is 10 or less, the volume of the organic compound occupying the furnace volume does not increase too much, and the productivity becomes better.

  As the alkali activator, an alkali metal compound is preferable. Examples of the alkali metal compound include hydroxides such as sodium hydroxide, potassium hydroxide, and lithium hydroxide; carbonates such as sodium carbonate, potassium carbonate, and lithium carbonate; These alkali activators may be used alone or in combination of two or more. Of these, potassium hydroxide is preferred.

  The mass ratio of the carbon raw material to the alkali activator (alkali activator / carbon raw material) is preferably 1.0 or more, more preferably 1.5 or more, still more preferably 2.0 or more, and 4.5 or less. Is more preferable, 4.0 or less, more preferably 3.5 or less.

  Moreover, when adding an alkali activator, in order to fully mix with a carbon raw material, you may use an alkali activator as aqueous solution. The amount of water used at this time is preferably 0.05 times by mass to 10 times by mass of the alkali activator. In addition, when using an alkali activator as an aqueous solution, before performing heating for the activation treatment, heating at a temperature lower than the heating temperature in the activation treatment is performed to prevent bumping of moisture derived from the alkaline activator aqueous solution. It is preferable to remove moisture by performing treatment.

  In the production method of the present invention, if necessary, the mixture of the carbon raw material and the organic compound may be allowed to stand for several minutes to several hours for the purpose of allowing the carbon raw material to conform to the organic compound. You may heat-process at the temperature below the boiling point of an organic compound.

  In the alkali activation step, the mixture obtained by mixing the above-described carbon raw material, organic compound and alkali activator is heated and activated. Here, the “activation process” is a process for forming pores on the surface of the carbon raw material to increase the specific surface area and the pore volume.

  Examples of the furnace used in the production method of the present invention include apparatuses that can uniformly heat raw materials such as a rotary kiln, a fluidized bed furnace, and a stirring and mixing furnace.

  The furnace temperature when the organic compound (including those mixed with other raw materials) is charged is preferably adjusted to be lower than the boiling temperature of the organic compound. For example, when N-methyl-2-pyrrolidone or toluene is used as the organic compound, the furnace temperature when the organic compound is added is preferably 200 ° C. or lower, more preferably 100 ° C. or lower, more preferably 50 ° C. or lower. It is. In addition, the minimum of the furnace temperature at the time of throwing in a mixture is not specifically limited, Room temperature may be sufficient.

  When the inside of the furnace is heated, an inert gas is introduced. What is necessary is just to adjust the inflow amount of inert gas suitably according to the volume of a furnace, and the preparation amount of a carbon raw material. Note that nitrogen, argon, helium, or the like can be used as the inert gas. The heating rate when heating the furnace is preferably 1 ° C./min or more, more preferably 5 ° C./min or more, further preferably 10 ° C./min or more, preferably 50 ° C./min or less, more preferably 30 ° C./min or less, more preferably 20 ° C./min or less.

  The heating temperature in performing the activation treatment is preferably 600 ° C. or higher, more preferably 650 ° C. or higher, further preferably 700 ° C. or higher, preferably 950 ° C. or lower, more preferably 900 ° C. or lower, and further preferably 850 ° C. or lower. It is. Further, the heating time in performing the activation treatment is preferably 0.1 hour or more, more preferably 1.0 hour or more, further preferably 1.5 hours or more, preferably 3.5 hours or less, more preferably It is 3.0 hours or less, more preferably 2.5 hours or less. The atmosphere during heating is preferably an inert gas atmosphere such as argon, helium, or nitrogen.

  In addition to the alkali activation step, the production method of the present invention may include a washing step, a heat treatment step, and a pulverization step.

  The washing step is a step of washing and drying the activated carbon after the activation step. Since the surface of the activated carbon after the activation step is attached with an alkali metal hydroxide used as an alkali activator, the activated carbon is washed to remove such deposits.

  Examples of the cleaning of activated carbon include water cleaning and acid cleaning.

  The washing method is not particularly limited, but for example, it is preferably performed by adding activated carbon to water, stirring and dispersing as necessary, and then filtering. The stirring and dispersion can be performed by mechanical stirring, gas blowing, and ultrasonic irradiation, but can also be performed by heating and boiling. The water temperature during washing is preferably 30 ° C. or higher, more preferably 40 ° C. or higher, and further preferably 50 ° C. or higher. The stirring and dispersing time is preferably 0.5 hours or more, more preferably 1 hour or more, and further preferably 1.5 hours or more.

  In the acid cleaning, the activated carbon is cleaned using a cleaning liquid containing an inorganic acid, an organic acid, or the like. The solvent for the cleaning liquid is not particularly limited, but is usually water. By performing the acid cleaning, the alkali metal hydroxide used as the alkali activator can be efficiently removed.

  Examples of the inorganic acid include hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, and carbonic acid. These inorganic acids may be used alone or in combination of two or more. When the inorganic acid is used, the concentration of the inorganic acid in the cleaning liquid is preferably 0.5 mol / L or more, more preferably 1.0 mol / L or more, still more preferably 1.5 mol / L or more, and 3.5 mol / L. L or less is preferable, More preferably, it is 3.0 mol / L or less, More preferably, it is 2.5 mol / L or less. When acid cleaning is performed using an inorganic acid, for example, activated carbon and a cleaning liquid containing an inorganic acid may be mixed and stirred at a temperature of 50 ° C. to 100 ° C. for 30 minutes to 120 minutes.

  Examples of the organic acid include formic acid, oxalic acid, malonic acid, succinic acid, acetic acid, propionic acid, and the like. These organic acids may be used alone or in combination of two or more. The concentration of the organic acid in the cleaning liquid containing the organic acid is preferably 1 vol% or more, more preferably 2 vol% or more, further preferably 5 vol% or more, and preferably 100 vol% or less, more preferably 80 vol%, Preferably it is 60 vol% or less. By setting the concentration of the organic acid to 1 vol% or more, the metal component removal effect by the organic acid can be obtained, but if the concentration becomes too high, the manufacturing cost increases. When acid cleaning is performed using an organic acid, for example, activated carbon and a cleaning liquid containing an organic acid are mixed, and the resulting mixture may be stirred at a temperature of 20 ° C. to 80 ° C. for 1 minute to 120 minutes. . The activated carbon after washing is preferably dried at 50 to 120 ° C. for 0.5 to 2.0 hours.

  In the manufacturing method of this invention, it is preferable to perform acid washing and water washing as a washing | cleaning process, More preferably, after performing acid washing, it is the aspect which performs water washing several times.

  The heat treatment step is a step of further heat-treating the activated carbon after the activation step or after the cleaning step in an inert gas atmosphere. By performing heat treatment on the activated carbon, the amount of functional groups on the surface of the activated carbon can be adjusted.

  Examples of the heat treatment include an aspect in which the activated carbon immediately after the activation process is heat-treated in an inert gas atmosphere; an aspect in which the activated carbon after the activation process is subjected to acid cleaning and / or water cleaning and then heat-treated in an inert gas atmosphere. Can do. As said inert gas, argon, nitrogen, helium etc. can be used, for example. The heat treatment temperature is not particularly limited, but is preferably 400 ° C. or higher and 1000 ° C. or lower.

  The pulverization step is a step of performing pulverization for adjusting the particle size of the activated carbon. The method for pulverizing the activated carbon is not particularly limited, and may be performed using a disk mill, a ball mill, a bead mill, or the like. The average particle diameter of the activated carbon is preferably 1 μm or more, more preferably 2 μm or more, and preferably 15 μm or less, more preferably 10 μm or less. If the average particle diameter is too small, the binding property between the current collector plate and the electrode material layer in the electrode is deteriorated, and the amount of binder required for the electrode material layer may be increased in order to maintain the practical binding property. is there.

  Activated carbon obtained by the production method of the present invention can be used as an electrode material for an electric double layer capacitor, and an electrode for an electric double layer capacitor or an electric double layer capacitor can be produced using the electrode material. is there. According to the production method of the present invention, for example, the pore diameter formed while increasing the specific surface area of activated carbon can be controlled. In other words, it is possible to further increase the specific surface area while maintaining the desired pore diameter, or to further increase the pore diameter while maintaining the desired specific surface area. Therefore, it is possible to further increase the specific surface area while forming pores having a pore diameter suitable for the ion size in the electrolytic solution. Therefore, by using the activated carbon obtained by the production method of the present invention for an electric double layer capacitor, an electric double layer capacitor having excellent capacitance can be obtained.

  Next, the electric double layer capacitor of the present invention will be described. The electric double layer capacitor of the present invention is characterized in that activated carbon obtained by the above-described manufacturing method is used as an electrode constituent material.

  As an electrode for an electric double layer capacitor, for example, activated carbon, a conductivity-imparting agent and a binder are kneaded, a solvent is further added to prepare a paste, and this paste is applied to a current collector plate such as an aluminum foil. Is obtained by drying and removing.

  As the binder used for the electrode for the electric double layer capacitor, fluorine-based polymer compounds such as polytetrafluoroethylene and polyvinylidene fluoride, carboxymethyl cellulose, styrene-butadiene rubber, petroleum pitch, phenol resin, and the like can be used. As the conductivity imparting agent, acetylene black, ketjen black, or the like can be used.

  An electric double layer capacitor generally has a structure in which an electrode, an electrolytic solution, and a separator are main components, and a separator is disposed between a pair of electrodes. Examples of the electrolytic solution include an electrolytic solution in which an amidine salt is dissolved in an organic solvent such as propylene carbonate, ethylene carbonate, and methyl ethyl carbonate; an electrolytic solution in which a quaternary ammonium salt of perchloric acid is dissolved; quaternary ammonium or lithium An electrolytic solution in which an alkali metal boron tetrafluoride salt or phosphorous hexafluoride salt is dissolved; an electrolytic solution in which a quaternary phosphonium salt is dissolved may be mentioned. Examples of the separator include cellulose, glass fiber, or a nonwoven fabric, cloth, or microporous film mainly composed of polyolefin such as polyethylene or polypropylene.

  The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited to the following examples, and may be appropriately modified and implemented within a range that can meet the purpose described above and below. All of which are within the scope of the present invention.

Method for measuring specific surface area, total pore volume and average pore diameter After 0.2 g of activated carbon was heated under vacuum at 200 ° C., N ₂ gas adsorption method using a nitrogen adsorption device (“ASAP-2400” manufactured by Micromeritics) And the specific surface area and total pore volume were determined by the BET method. The average pore diameter was calculated based on the following formula (1) using the specific surface area determined by the BET method and the pore volume in the range of 1.0 to 30 nm.

Production Example 1
20.00 g of coal pitch coke as carbon material (Mitsubishi Chemical Co., Ltd., coal pitch coke, average particle size less than 75 μm), 10.28 g of N-methyl-2-pyrrolidone as organic compound (organic compound / carbon raw material (mass ratio) ) = 0.5) and 50 g of potassium hydroxide (potassium hydroxide / carbon raw material (mass ratio) = 2.5) were placed in a stainless steel container and mixed at room temperature (25 ° C.) using a spatula.

  Subsequently, the obtained mixture was accommodated in a rotary kiln (cylindrical furnace, manufactured by Osaka Seiko Co., Ltd.) having a furnace temperature of 25 ° C., and the furnace temperature was raised to 800 ° C. under nitrogen flow (1 L / min) (increased). (Temperature rate: 10 ° C./min). After the furnace temperature reached 800 ° C., it was maintained for 2 hours under nitrogen flow (1 L / min), and an alkali activation treatment was performed.

  To the obtained mixture of activated material and potassium component, 1.6 L of water and 0.4 L of hydrochloric acid (concentration: 35% by mass) were added, heated at 100 ° C. for 2 hours, and then the activated material was collected by filtration to wash hydrochloric acid. went. Thereafter, 2 L of water was added to the activated product after washing with hydrochloric acid, heated to 100 ° C. and boiled for 2 hours, and then the activated product was filtered to perform warm water washing. The same operation was repeated, and washing with warm water was further performed once.

  The activated product that had been washed once with hydrochloric acid and washed twice with warm water was dried at 110 ° C. for 2 hours. The activated product after drying was pulverized using a disk mill, and adjusted so that the average particle size was 8 μm to obtain activated carbon. The obtained activated carbon was evaluated and the results are shown in Table 1.

Production Example 2
Except having changed the usage-amount of N-methyl-2-pyrrolidone (NMP) which is an organic compound into 1.03 g (organic compound / carbon raw material (mass ratio) = 0.05), it carried out similarly to manufacture example 1, and. Activated carbon was obtained. The obtained activated carbon was evaluated and the results are shown in Table 1.

Production Example 3
Except having changed the usage-amount of N-methyl-2-pyrrolidone (NMP) which is an organic compound into 51.40g (organic compound / carbon raw material (mass ratio) = 2.6), it carried out similarly to manufacture example 1, and. Activated carbon was obtained. The obtained activated carbon was evaluated and the results are shown in Table 1.

Production Example 4
Activated carbon was obtained in the same manner as in Production Example 1 except that the organic compound was changed to 43.35 g of toluene (organic solvent / carbon raw material (mass ratio) = 2.2). The obtained activated carbon was evaluated and the results are shown in Table 1.

Production Example 5
Kraft paper (basis weight 200 g / m ² ) is used as a paper substrate, a phenol resin varnish made of a resol resin is prepared as a phenol resin, and the coating resin amount is 30 parts by mass with respect to 70 parts by mass of the paper substrate. A paper base was coated and impregnated, and dried at about 160 ° C. to prepare a prepreg. A plurality of prepregs were laminated, both sides were sandwiched between stainless steel mirror plates, and cushion materials were stacked on both sides, and set between the hot plates of a multistage hydraulic press. In this state, after heat-pressing under conditions of a temperature of 140 ° C., a pressure of 6.9 MPa (70 kgf / cm ² ), and a time of 90 minutes, the stencil and edge cutting were performed, and the dimensions were 1020 mm × 1020 mm and the thickness was 1.5 mm. A paper-phenolic resin laminate was obtained. The obtained paper-phenol resin laminate was pulverized to 5 mm or less.

  20.01 g of paper-phenol resin laminate (average particle diameter less than 5 mm) as a carbon material, 51.40 g of N-methyl-2-pyrrolidone as an organic compound (organic compound / carbon raw material (mass ratio) = 2.6) Then, 50 g of potassium hydroxide (potassium hydroxide / carbon raw material (mass ratio) = 2.5) was put in a stainless steel container and mixed with a spatula at room temperature (25 ° C.).

  Subsequently, the obtained mixture was accommodated in a rotary kiln (cylindrical furnace, manufactured by Osaka Seiko Co., Ltd.) having a furnace temperature of 25 ° C., and the furnace temperature was raised to 800 ° C. under nitrogen flow (1 L / min) (increased). (Temperature rate: 10 ° C./min). After the furnace temperature reached 800 ° C., the alkali was activated by maintaining for 2 hours under nitrogen flow (1 L / min). Next, hydrochloric acid washing, warm water washing and pulverization were performed in the same manner as in Production Example 1 to obtain activated carbon. The obtained activated carbon was evaluated and the results are shown in Table 1.

Production Example 6
The paper-phenolic resin laminate (average particle diameter less than 5 mm) prepared in Production Example 4 was heat-treated at 700 ° C. for 2 hours in a nitrogen atmosphere to obtain a paper-phenolic resin laminate carbide.

  Paper-phenol resin laminate carbon 20.00g as carbon raw material, toluene 43.35g as organic compound (organic compound / carbon raw material (mass ratio) = 2.2), potassium hydroxide 50g (potassium hydroxide / carbon raw material) (Mass ratio) = 2.5) was placed in a stainless steel container and mixed at room temperature (25 ° C.) using a spatula.

  Subsequently, the obtained mixture was accommodated in a rotary kiln (cylindrical furnace, manufactured by Osaka Seiko Co., Ltd.) having a furnace temperature of 25 ° C., and the furnace temperature was raised to 800 ° C. under nitrogen flow (1 L / min) (increased). (Temperature rate: 10 ° C./min). After the furnace temperature reached 800 ° C., the alkali was activated by maintaining for 2 hours under nitrogen flow (1 L / min). Next, hydrochloric acid washing, warm water washing and pulverization were performed in the same manner as in Production Example 1 to obtain activated carbon. The obtained activated carbon was evaluated and the results are shown in Table 1.

Production Examples 7-9
Except that no organic compound was used, activated carbon was obtained using the same alkali activator usage (potassium hydroxide / carbon raw material (mass ratio) = 2.5) and heat treatment conditions as in Production Examples 1, 5, and 6. It was. The obtained activated carbon was evaluated and the results are shown in Table 1.

  Production Examples 1 to 4 and 7 use coal pitch coke as a carbon raw material and change only the type and amount of the organic compound. Comparing the activated carbons obtained in these production examples, the production surfaces 1 to 3 using N-methyl-2-pyrrolidone as the organic compound have a specific surface area as compared to Production Example 7 using no organic compound. It is large and the average pore diameter is small. In addition, when the manufacture examples 1-3 are compared, it turns out that the collection amount of activated carbon after activation increases, so that the usage-amount of an organic compound increases, and the specific surface area of activated carbon becomes high, so that the usage-amount of an organic compound decreases. Further, in Production Example 4 using toluene as the organic compound, the specific surface area is twice or more larger than that in Production Example 7, and the average pore diameter is small.

  In Production Examples 5 and 8, a paper-phenolic resin laminate is used as a carbon raw material, and only the amount of the organic compound used is changed. When the activated carbons obtained in these production examples are compared, the production surface 5 using N-methyl-2-pyrrolidone as the organic compound is more specific than the production surface 8 in which no organic compound is used. The hole diameter is all small. Here, referring to FIG. 2, in Production Example 8, many pores having a pore diameter of 2 nm or more are formed, whereas in Production Example 5, formation of pores having a pore diameter of 2 nm or more is suppressed.

  Production Examples 6 and 9 use paper-phenol resin laminate carbide as a carbon raw material, and change only the amount of organic compound used. When the activated carbons obtained in these production examples are compared, in Production Example 6 using toluene as the organic compound, both the specific surface area and the average pore diameter are larger than those in Production Example 9 using no organic compound. ing.

  The present invention can control the physical properties of activated carbon, and thus is useful for the production of activated carbon required to have appropriate physical properties (for example, specific surface area, pore diameter, etc.).

Claims (6)

  A method for producing activated carbon, comprising: mixing a carbon raw material and an organic compound having a melting point of 250 ° C. or less and then activating the alkali.   The method for producing activated carbon according to claim 1, wherein the carbon raw material and the organic compound are mixed at a temperature equal to or higher than the melting point of the organic compound.   The method for producing activated carbon according to claim 1, wherein the organic compound is a heterocyclic compound or an aromatic hydrocarbon.   The method for producing activated carbon according to any one of claims 1 to 3, wherein a mass ratio of the organic compound and the carbon raw material (organic compound / carbon raw material) is 0.05 or more and 10 or less.   The carbon raw material is at least one selected from the group consisting of coal pitch coke, coal, petroleum coke, coal coke, petroleum pitch coke, synthetic resin, composite of synthetic resin and cellulosic fiber, and carbides thereof. The manufacturing method of activated carbon as described in any one of Claims 1-4.   An electric double layer capacitor, wherein the activated carbon obtained by the production method according to claim 1 is used as an electrode constituent material.