WO2007037508A1

WO2007037508A1 - Activated carbon and process of making the same

Info

Publication number: WO2007037508A1
Application number: PCT/JP2006/319900
Authority: WO
Inventors: Youichi Nanba; Takashi Mori; Susumu Nakazaki
Original assignee: Showa Denko K.K.
Priority date: 2005-09-29
Filing date: 2006-09-27
Publication date: 2007-04-05
Also published as: EP1937591A1; US7964530B2; KR100932158B1; KR20080022105A; TW200728198A; CN101218174B; EP1937591A4; US20090080142A1; WO2007037508A9; CN101218174A

Abstract

An activated carbon having the highest peak D within the range of 1.0 nm to 1.5 nm, in which the peak D is from 0.012 to 0.050 cm3/g and is from 2 % to 32 % to a total pore volume, in pore size distribution as calculated by BJH method from N2-adsorption isotherm at 77.4 K. An electric double layer capacitor comprising the polarizable electrode which comprises the activated carbon, carbon fiber, carbon black, and binder.

Description

DESCRIPTION

ACTIVATED CARBON AND PROCESS OF MAKING THE

This application claims benefit pursua U. S. C. §119 (e) (1) of Provisional Applicatio 60/723,941 filed on October 6, 2005, Provis Application No. 60/733210 filed' on November 4 Provisional Application No. 60/752395 filed 22, 2005 pursuant to' 35 U. S. C. §111 (b) , the of which are incorporated herein by referen application is based on Japanese Patent Appl 2005-283321 filed on September 29, 2005, Japa Application No. 2005-312286_'filed on October 2 Japanese Patent Application No. 2005-362773 December 16, 2005, the contents of which are i herein by reference.

Technical Field The invention relates £o an activated c process of making the activated carbon. Espe invention relates to an activated carbon havi stocking property, and high adsorption quant such as hydrocarbon gas having low molecular if BET specific surface area is low. Also th relates to an activated carbon useful as m Background Art

[0002] An activated carbon is known as adsorbe important position for various industrial fi food, medicine, housing, automobile, chemica Also the activated carbon is considered as ad stocking gas mainly containing natural ga substitute for petroleum resource such as g

Natural gas mainly contains methane Generally speaking, an activated carbon bein BET specific surface area and being larger i micro pore having pore diameter of lnm or le more adsorption of gas having small molecula as methane, ethane, or other hydrocarbon gas molecular weight, or hydrogen. Adjustment o carbon structure such as pore diameter, pore pore configuration is researched to improve > property of activated carbon, i.e. to enlarge adsorption quantity for gas having set mole However, activated carbon having larger speci area is lower in a packing property into ta [0003] JP-A-06-55067 discloses an adsorbent carrying metallic simple substance or metalli which has chemical adsorption ability for met activated carbon having BET specific surfa approximately 750 m²/g or more.

JP-A-07-155587 su ests an activated ca with metallic compound in the 8th group.

In JP-A-2001-122608 is described an acti obtained by activating with alkali metallic co activated carbon has volume of micro pore, wh diameter of approximately 0.7 to 1.2 nm, of 5 to the total pore volume.

[0004] An activated carbon is useful for mat polarizable electrode in an electric do capacitor. An electric double layer capacitor chargable and dischargable, tough against ov overdischarge, long in life for cause of reaction, workable under wide range of tempe easy on the environment for cause of heavy met has other property which battery does not have . double layer capacitor is mainly employed f backup power supply and so on. An electric d capacitor is researched in application to ele storing system or engine assist for hyb assembling with battery such as solar batte cell .

[0005] An electric double layer capacitor comp of polarizable electrodes as cathode and anod material containing an activated carbon, in wh of polarizable electrodes set facing eac solution containing electrolytic ion, and a s inter osed between the olarizable electrodes . electric double layer supplies electric ene

'[0006] Therefore, using of activated carbon ha specific surface area have been researched to electric double layer. The using of this activ enlarges an electric capacity'per mass (F/g) , of electrode is lowered. Consequently an electr per volume (F/cm³) is not as large as expect

[0007] There is suggestion in JP-A JP-A-2000-68164, and JP-A- 2000-68165 that a carbon, which is made by activating with alka compound, having micro-crystalline structure graphite structure, and having distance betwe 0.365nm to 0.385nm, is used as material for electrode. An electric double layer capacitor activated carbon is employed as material for electrode, has large electric capacity per vol . and thus the activated carbon may be good mate of an electric capacity per volume.

[0008] In producing method for activated carbon a step of activating coke with potassium hydr to form pore, it is difficult to control su diameter of activated carbon for electric d capacitor workable under cryogenic temperat

[0009] JP-B-319563 or JP-A-2004-182511 pr activated carbon having meso-pore being withi in a pore diameter obtained by activating raw ma inside particle. It is shown that the activ having a pore volume of 0.02 cmVg or more, i pore volume lS'within 2.0 to 5.0 nm in a pore dia pore size distribution as calculated by BJH enlarge an electric capacity of electric d capacitor.

Disclosure of Invention

[0011] According to the review of the inv JP-A-β-55067, the activated carbon having surface area of 3000 m /g reaches more than a methane adsorption quantity, but so lar surface area lowers quantity of packing in Activated carbon having specific surface area s filling in tank etc. of about 1500 m /g perfo adsorption quantity of 100 mg/g or less.

The activated carbon in JP-A-7-1555 efficiency of pore utilization for adsorption as methane, since the pore is filled or sq metallic compound on the surface.

The activated carbon in JP-A-2001-122608 adsorption quantity of 100 mg/g or less.

[0012] The object of the invention is to activated carbon suitable for gas adsorbent efficiently adsorb and stock methane or natura containing methane under low relative pressu [0013] An electric double layer capacitor premised on using under room temperature m t of 25 ⁰C. This performs relatively high electr under room temperature. However, under temperatures in the vicinity of -30 ⁰C, discharge capacitance remarkably decreases, a resistance increases. The main cause is that of viscosity of electrolytic solution unde temperatures decreases an electrolytic ion pore of activated carbon.

Increasing pore volume (cm³/g) of activ was conventionally attempted in order electrolytic ion mobility under cryogenic te When only increasing pore volume (cmVg) internal resistance under cryogenic temperatur of activated carbon in electrode declines, w » to drop an electric capacity per volume (F/

The other object of the invention is to activated carbon and an electric double laye which has good property of charge and discha internal resistance especially under temperatures (in the vicinity of -30 ⁰C) .

[0014] After the inventors did every research the goal, they found out that an activated ca the highest peak D within the range of 1.0 t pore size distribution, in which the peak D (ex. _^-30 ⁰C) .

[0015] The inventors further found out that a carbon, under pore size distribution as calcu method from adsorption isotherm, having peak range of 2.1 to 2.4 nm in a pore diameter, pe the range of 1.7 to 2.1 nm m a pore diameter, p the range of 1.4 to 1.7 nm in a pore diamete d within the range of 1.1 to 1.4 nm in a por or an activated carbon having peak a within t 2.1 to 2.4 nm in a pore_, diameter, peak b withi of 1.7 to 2.1 nm m a pore diameter, peak c with of 1.4 to 1.7 nm in a pore diameter, peak d with of 1.1 to 1.4 nm in a pore diameter, peak e with of 0.8 to 1.1 nm in a pore diameter, peak f with of 0.4 to 0.8 nm in a pore diameter, and having ratio of these areas each enclosed with pore di - and distribution curve of each peak within the diameter range, can give an electric do capacitor which has good property of charge an and low internal resistance under cryogenic t (ex. -30 ⁰C) . The invention is made on the knowledge .

[0016] The invention specifically comprises th modes .

(1) An activated carbon having at lea within the ran e of 1.0 nm to 1.5 nm in a specific surface area, as measured by BE N₂-adsorption, of 1500 m²/g to 2200 m²/g.

(3) An activated carbon having the h being a peak D within the range of 1.0 nm to which the peak D is from 0.012 cm³/g to 0.05 from 2 % to 32 % to a total pore volume, i distribution as calculated by BJH me N₂-adsorption isotherm at 77.4 K.

(4) The activated carbon according to a specific surface area, as measured by BE N₂-adsorption, of 1100 m²/g to 2200 m²/g.

(5) The activated carbon according to (1) to (4) , having a peak C within the range 1.7 nm in pore size distribution.

(6) The activated carbon according to (1) to (5) , having a peak B within the range

. 2.0 nm in pore size distribution.

(7) The activated carbon according to (1) to (β) , having a peak A within the range o 2.5 nm m pore size distribution.

[0017] (8) An activated carbon, in pore,size d as calculated by BJH method from N₂-adsorpti at 77.4 K, having a peak a within the range of 2. nm in a pore diameter, a peak b within the r nm to 2.1 nm in a ore diameter, a eak c withi are each enclosed with pore diameter axis and d curve of each peak within the above pore diam [0018] (9) An activated carbon, in pore size d as calculated by BJH method from N₂-adsorpti at 77.4 K, having a peak a within the range of 2. nm in a pore diameter, a peak b within the r nm to 2.1 nm in a pore diameter, a peak c withi of 1.4 nm to 1.7 nm in a pore diameter, a pe the range of 1.1 nm to 1.4 nm in a pore diame e within the range of 0.8 nm to 1.1 nm in a por and a peak f within the range of 0.4 nm to 0.8 diameter, and having area f of 2.2 to 2.5, area e of area d of 4.6 to 4.8, area c of 2.1 to 2.3 an 1.9 to 2.1, supposing that area a is 1, in whi . a, the area b, the area c, the area d , the the area f are each enclosed with pore diamet distribution curve of each peak within the diameter range.

[0019] (10) A process of making an activa comprising steps of: carbonizing pitch in the presence of 7000 in metallic element concentration of chemical Z any of elements in the 2nd group, any of elem 3rd to 11th groups of the 4th period, or ele [0020] (11) A process of making an activa comprising steps of: carbonizing pitch to obtain a graphiti mixing the graphitizable coke with 7000 in metallic element concentration of chemical Z any of elements in the 2nd group, any of elem 3rd to 11th groups of the 4th period, or ele 4th group of the 5th period on periodic tabl a mixture, activating the mixture in the presenc metallic compound, and then washing the activated mixture.

[0021] (12) The process of making an activa according to (10) or (11), in which the graphit has true density of 1.44 g/cm³ to 1.52 g/cm³

(13) The process of making an activa > according to any one of (10) to J12), in whic has softening point of 100 ⁰C or less.

(14) The process of making an activa according to any one of (10) to (13), in whic comprises coal based pitch, petroleum based organic solvent soluble constituent thereof.

(15) The process of making an activa according to any one of (10) to (14) , in which t Z comprises simple substance or compound, co least one element selected from the group co chloride, bromide, iodide, fluoride, carbonate, sulfide, sulfate and nitrate.

(17) The process of making an activ according to any one of (10) to (16), in which metallic compound comprises alkali metallic

(18) The process of making an activ according to any one of (10) to (17), m which metallic compound comprises a compound contain one element selected from the group consisti and Cs.

[0022] (19) A carbon composite powder comp activated carbon according to any one of (1) a carbon fiber.

(20) The carbon composite powder accord in which the carbon fiber has pore therein, surface area of 10 m /g to 50 m /g, an avera » of fiber of 50 nm to 500 ran, and an aspect ra

1000. [0023] (21) A polarizable electrode comp activated carbon according to any one of (1) to black, and binder.

(22) A polarizable electrode comp activated carbon according to any one of (1) to fiber, carbon black, and binder.

(23) The polarizable electrode accordi in which the amount of the carbon fiber is 0. of 5 to 1000.

(25) The polaπzable electrode accordi of (21) to (24), in which the binder compris one polymer selected from the group con polytetrafluoroethylene, pol^vinylidenefluo comprising acrylate monomer unit, and rubber butadiene monomer unit.

[0024] (26) An electric double layer capacitor the polaπzable electrode according to any on (25).

(27) The electric double layer capacito to (26) , comprising electrolytic solution d least one electrolytic salt selected from consisting of quaternary ammonium salt, lmidazolium salt, quaternary pyridmium quaternary phosphonium salt into organic solve electrolytic cation is 3 A to 15 A in an io

electrolytic anion is 5 A to 10 A in an ion [0025] (28) _t A sdurry comprising the activa according to any one of (1) to (9) .

(29) A paste comprising the activa according to any one of (1) to (9) .

(30) An electrode sheet, in which th carbon according to any one of (1) to (9) is a the surface thereof. (34) A ship in which the electric d capacitor according to (26) or (27) is empl

(35) An aircraft in which the electric capacitor according to (26) or (27) is empl

(36) A portable apparatus in which t double layer capacitor according to (26) employed.

(37) An apparatus for office work i electric double layer capacitor according to is employed.

(38) A solar power generation system i electric double layer capacitor according to is employed.

(39) A wind power generation system i electric double layer capacitor according to is employed.

(40) A communication apparatus m electric double layer capacitor according to is employed.

(41) An electronic tag m which the elec layer capacitor according to (26) or (27) i (42) An adsorbent comprising the activ according to any one of (1) to (9) .

(43) The adsorbent according to (42), hydrocarbon gas having 1 to 4 of carbon ato 44 A reventin device from adsorbent according to (42) or (43) is empl [0027] The activated carbon in the invention adsorb hydrocarbon gas such as methane under l pressure, regardless of low specific surface causes to be good packing property in a stor downsize a plant. So the activated carbon in th is favorable adsorbent for a storage unit of on a natural gas automobile, or a canister on automobile etc.

The activated carbon m the inventio electrolytic ion mobility at cryogenic temper raise activated carbon density in electrode re low internal resistance at cryogenic temperat activated carbon in the invention is fav material of polarizable electrode of an elec layer capacitor.

Brief Description of Drawings

[0028] FIG. 1 : Section of cell for performa electric double layer capacitor

FIG. 2 : Distribution curves of po activated carbon obtained m Example 1 and examples 1 to 3

FIG. 3 : Distribution curves of po activated carbon obtained in Examples 5 Com arative exam le 4 [0029] curve K : pore size distribution of activ

_^ obtained in Example 1; curve L : pore size distribution of activ obtained in Example 2; curve M : pore size distribution of activ obtained in Example 3; curve N : pore size distribution of activ obtained in Comparative Example 1; curve O : pore size distribution of activ obtained in Comparative Example 2;

1 : lid;

2 : 0-ring;

3 : current collector;

4 : insulator;

5 : vessel;

6 : plate spring; > 7 : electrode;

8 : separator; a : peak a; b : peak b; c : peak c; d : peak d

Best Mode for Carrying Out the Invention

[0030] [ACTIVATED CARBON] n tiva c n in the invention has at 77.4 K. Concretely, activated carbon is co 77.4 K (boiling point of nitrogen), nitro introduced, and adsorption quantity of nit [cc/g] is measured by volume method. The values are plotted onto x-axis of ratio equilibrium adsorption pressure of nitrogen and saturated vapor pressure of nitrogen gas and y-axis of adsorption quantity of nitrogen to make N₂~adsorption isotherm. Pore size d analysis is carried out by BJH (Barrett-joyn method from the N₂-adsorption isotherm. BJH me is well known in the art, for instance, may be by the method as described in J. Amer. Chem 373. (1951) .

The pore size distribution analysis ca size distribution curve on x-axis of pore d y-axis of pore volume, as shown in FIG. 2 to

4 are distribution curves of pore size of activ obtained in the_^ subsequent Examples. The activated carbon in the invention has Peak D of 0.012 to 0.05 cm³/g, preferably 0. cm³/g. The peak D of less than 0.012 cm³/g cau an electrolytic ion mobility inside pore whe of electrolytic solution rises at cryogenic te lowering charge and discharge property an internal resistance ro ert at cr o enic te adsorption quantity increases.

[0033] The preferable activated carbon has any C within the range of 1.5 to 1.7 nm in a por a peak B within the range of 1.7 to 2.0 nm in a po and a peak A within the range of 2.0 to 2.5 n diameter. In FIG. 4, pore size distribution sh M (Example 10) has peak D at approximately 1.22 diameter, peak C at approximately 1.54 nm diameter, peak B at approximately 1.85 nm diameter, and peak A at approximately 2.28 n diameter. Pore size distribution shown by curv 9) has peak D, peak C₁ and peak B. Pore size d shown by curve K (Example 8) has peak D an,d

[0034] The activated carbon in the invention h

D of 2 to 32 %, preferably 20 to 31 % to total p

The peak D falling within the range result

• adsorption quantity of hydrocarbon gas such

[0035] An activated carbon in the invention, und distribution as calculated by BJH me N₂~adsorption isotherm at 77.4 K, has a peak a range of 2.1 to 2.4 nm m a pore diameter, a pe the range of 1.7 to 2.1 nm in a pore diamete within the range of 1.4 to 1.7 nm in a pore di a peak d within the range of 1.1 to 1.4 nm in a por and has area d of 3.7 to 4.8, area c of 1.6 to 2 b of 1.6 to 2.1 su osin that area a is 1 i N₂-adsorption isotherm at 77.4 K, has a peak range of 2.1 to 2.4 nm m a pore diameter, a p the range of 1.7 to 2.1 nm in a pore diamete within the range of 1.4 to 1.7 nm m a pore peak d within the range of 1.1 to 1.4 nm in a por a peak e within the range of 0.8 to 1.1 nm in a po and a peak f within the range of 0.4 to 0.8 n diameter, and has area f of 2.2 to 2.5, area 2.5, area d of 4.6 to 4.8, area c of 2.1 to 2 jb of 1.9 to 2.1, supposing that area a is 1, i area a, the area b, the area c, the area d , and the area f are each enclosed with pore di and distribution curve of each peak within th diameter range.

[0037] An activated carbon in the invention has surface area as measured by BET method on N₂ > of preferably 1100 to 2200

prefera 2200 m²/g, particularly preferably 1800 to 2

BET specific surface area of activated small that total pore volume is lowered, f electrolytic ion mobility at cryogenic te degrading property of charge and disch adsorption quantity of gas such as methan decrease .

BET specific surface area of activated c large that electrode density is lowered, de volume of peak D [cm³/g] falls within th preferably^'500,000 : 1 to 800,000 : 1.

[0038] An activated carbon in the invention pre tapping density (number of tapping is 50) of g/cm³, and powder resistance at 1 MPa of no mo Ωcm. Tapping density can be measured with tapp measure (made by KURAMOCHI KAGAKU KIKAI SEIS

[0039] [PROCESS of MAKING ACTIVATED CARBON]

A process of making an activated car invention is not particularly limited. Menti preferable process are process (A) of making a carbon comprising steps of carbonizing pi presence of 7000 ppπi or more in metall concentration of chemical Z containing any of the 2nd group, any of elements in the 3rd to of the 4th period, or element in the 4th grou ¹ period on periodic table to obtain a graphiti activating the graphitizable coke in the alkali metallic compound, and then washing th coke, and process (B) of making an activated carbon steps of carbonizing pitch to obtain a graphiti mixing the graphitizable coke with 7000 ppm metallic element concentration of chemical Z any of elements in the 2nd group, any of elem rd to 11th rou s of the 4th eriod or ele such as specific surface area, pore size di crystalline structure. The structural p activated carbon is decided by structure of ra condition of carbonization, condition of act the like. Thus structure of raw material, c carbonization, condition of activation and th to be optimized in order to obtain a usefu carbon for electrode material.

[0041] It is proper that pitch used in the proce an activated carbon in, the invention has a lo point. In the pitch, there are petroleum based based pitch, organic solvent soluble constitu and so on. In the invention, organic solve constituent of petroleum based pitch or that o pitch is particularly preferably used. The cons less side chain, and higher content of aromat » that mingles polycyclic aromatic compounds hav molecular structure than a hardly graphitiz material. It is considered that an activated from the constituent has formation of various micro-crystalline structure coming -from aromatic compounds, which causes a good electr and a good gas adsorption property. The pitch invention is preferably not more than 10 preferably 60 to 90 ⁰C in a softening point.

[0042] A chemical Z used in the process in th table.

As the chemical Z may be used any of simpl inorganic compound, and organic compound. inorganic compound are oxide, hydroxide, bromide, iodide, fluoride, phosphate, carbona sulfate and nitrate. As organic compound i organometallic complex, with ligand as ace cyclopentadien, such as tetraalko acetylacetonetributoxyzirconium.

Compound containing at least one eleme from the group consisting of Ca, Ti, Mn, Fe, and Zr is preferable as the chemical Z. materially mentioned calcium oxide, titanium oxide, nickel oxide, and zirconium oxide. The Z may be used alone or in combination with t [PROCESS (A) OF MAKING ACTIVATED CARBON]

In a process (A) of making an activate the invention, first of all, pitch is carbon presence of the chemical Z to obtain a graphiti Specifically, the pitch and the chemical Z ar the mixture may be heated. The manner for mi pitch and the chemical Z is not particularly they can be uniformly mixed. For instanc temperature, powder of chemical Z is added powder, and is stirred to obtain mixture. Ment manner for stirring are V-shaped Mixer, Hens catalyst for the activation step. Metall concentration (ppm) is the value as calcul following formula:

[mass of metallic element in che /([mass of pitch having softenin + [mass of chemical Z] ) x 10⁶

[0045] The manner for carbonizing is not p limited, to start with, first carbonizati carried out within the range of 400 to 700 ⁰C, 450 to 550 ⁰C in / temperature, and th carbonization step is carried out within the r to 700 ⁰C, preferably 540 to 670 ⁰C in t Temperature in the second carbonization step higher than that in the first carbonization

The carbonization leads pyrolysis re pitch. The pyrolysis reaction¹ causes to des light fraction from the pitch, polycondens thereof to obtain solid finally. The carboni almost decides micro-bounding state between ca The decided crystalline structure of coke i determines foundation of structure of resultan carbon.

[0046] Temperature of less than 400 ⁰C carbonization step unlikely causes enough reaction and carbonization. Temperature of 700 ⁰C is tend to make a surfeit of ra in period of holding at maximum temperature

[0047] Temperature of less than 500 ⁰C m carbonization -step is not apt to cause workin second carbonization step. Temperature of more in the second carbonization step is tend to ma of graphite like micro-crystalline structure to be difficult for activation with alkalin The second carbonization step is pref 100 °C/hr, more preferably 4 to 60 °C/hr in a he and preferably 0.1 to 8 hours, more preferab hours in period of holding at maximum tempera second carbonization step, high heating rate, s of holding at maximum temperature, and low c may allow to provide the activated carbon in the It is preferable to take 5 to 170 hours t temperature from maximum temperature to room t

[0048] The graphitizable coke obtained by carbonization step is to have true density of 1.44 to 1.52 g/cm³, more preferably 1.45 to The true density falling within the range m provide the activated carbon in the inventio true density is measured by liquid-phase s method (picno meter method) .

[0049] It is preferable that the graphiti obtained by the above carbonization step is an average particle diameter of 1 to 30 μm contamination in particle can not be somet removed from the resultant activated carbon. of metallic contamination likely causes to cut of the adsorbent.

[0050] In the process (A) of making an activa afterward, the obtained graphitizable coke i in the presence of alkali metallic compound. Sp the graphitizable coke is mixed ₍ with alka compound, and the mixture is heated.

[0051] Alkali metallic _^compound used in the making an activated carbon in the invent particularly limited. Alkali metallic hydrox sodium hydroxide, potassium hydroxide, cesiu is preferable as alkali metallic compound. Alka compound is used preferably 1.5 to 5 times, more 1.7 to 3 times as heavy as the coke.

[0052] An activating temperature is usually 60 preferably 700 to 760⁰C. An activation is usua out in atmosphere of inert gas. As inert gas ar nitrogen gas, argon gas and the like. Also, w carbon dioxide and so on, if needs be, may be during activation.

[0053] In the activation, for instance, whe hydroxide is used, potassium hydroxide is dehydrated at 300 to 400 ⁰C. Activation reac with otassium metal and water va or at 400 reactant, which requires volume of vessel en than that of the reactant. The comp graphitizable coke and carbon fiber can re sparkle or bumping.

[0054] In the process in the invention, al obtained by reduction reaction of alkali metall enters and opens between carbon layer graphitizable coke to make many spaces.

We guess that an electrolytic ion (solv 3.7 A m radius) is intercalated between ca

of 3.35 to 4 A in space at time of applying the capacitor, is adsorbed onto the pore surfa the space between the ca-rbon layers, whereby t capacity grows higher.

In the conventional activation with al using of carbon by reaction with water or car results making pore, space between carbon lay alkali metal is small. As the result, th conventional capacitor having high electric

[0055] In the process m the invention, the act be carried out in the presence of alkali metal alkali metal vapor can be used instead of s metallic compound or together solid alkal compound, since the intercalation of alkali me carbon layers makes pore. of washing efficiency and removability, hydroc or citric acid is preferable. Concentration preferably 0.01 to 20 normality, more prefer 1 normality.

[0057] In a manner for washing, acid may be a mixed with the coke. Boiling or heating at 50 preferable for improvement of washing efficien of ultrasonic wave washer is effective. Wash usually 0.5 to 24 hours, preferably 1 to 5

Number of washing operation depends on for washing. For example, 1 to 5 boiled-a operations and then 1 to 5 heated-water-washmg are preferable for removal of residual chlori made from material such as glass lining, ta TEFLON (registered trade mark) is preferably acid-washmg operation.

[0058] In the washing step, full automatic _^ heating filter dryer such as multi function Filter provided,by NISSEN Co. Ltd.) and FV drye by OKAWARA MFG. Co. Ltd. ) may be used. Pure wa washing has ionic electric conductivity of n 1.0 μS/cm. A waste fluid from washing step ma as a part of washing water by recycling.

[0059] [PROCESS (B) OF MAKING ACTIVATED CARBON]

In the other process (B) for making th n n th inven ion first of all itch is carbonization is adjusted to a true density to 1.4 to 1.6 g/cm³, more preferably 1.44 to especially preferably 1.45 to 1.52 g/cm³. Th a true density easily results obtaining th carbon in the invention. The true density is measured by liquid-phase substitution method ( method) .

[0060] Then, 7000 ppm or more, preferably 10000 in metallic element concentration of chemical with the graphitizble coke obtained by carbonization, the mixture is activated in t of alkali metallic compound. Specific graphitizable coke, alkali metallic compou chemicals Z may be mixed and heated. The man activation is the similar to that described process (A) . The metallic element concentra • value calculated by the following formula:

[mass of metallic element in che / ( [mass of coke] + [mass of chemic Finally, the coke activated by the ab washed. The manner for washing is the sa described in the above process (A) .

[0061] The alkali activation, of the graphit obtained by the carbonization of pitch in the the chemicals Z, or of the mixture that the co b carbonization of itch is mixed with the c retention rate of the electric capacity.

The enough carbonization of the graphit decreases the 'amount of functional group on of carbon to restrain the electric cap degradation.

[0063] [CARBON COMPOSITE POWDER]

A carbon composite powder in the inventio the activated carbon in the invention and a ca The carbon composite powder is obtained by comp carbon fiber with the _^activated carbon. The compounding is not particularly limited. It is that the mixture of the carbon fiber and the gr coke is activated to obtain the carbon compo comprising the carbon fiber and the activated c manner decreases a contact resistance b particles, increases an electric condμcti • mechanical strength of electrode, and lowers a rate of the electrode at the time of applyi Also, the carbon composite powder may be produc mixing the carbon fiber with the activated carbon composite powder has larger thermal c than the activated carbon alone has.

[0064] The carbon fiber used in the invent produced by, for example, spraying benzene a catalyst particle into current of hydrog a roximatel 1000 ⁰C. A ra hitized carbon f specific surface area of 10 to 50 m /g, an avera of fiber of 50 to 500 nm, and an aspect ratio o Any carbon fiber such as a linear carbon fiber, carbon fiber or mixture thereof may be empl

[0066] The preferable fiber length of carbon f to 2 times as long as average diameter of th carbon. When carbon fiber length is 0.5 ti crosslinking of carbon fiber between the activ particles is not made, being likely insuffi electric conductivity ._^When carbon fiber lengt longer, carbon fiber unlikely interpos activated carbon particles, likely lowering a strength of polarizable electrode.

[0067] A carbon fiber treated by activation activation (water vapor, carbon dioxide a chemical activation (zinc chloride, phosph ^v calcium carbonate and so on) , alkaline (potassium hydroxide, sodium hydroxide, and s employed, as the carbon fiber has a concentr orientation structure . In this situation, the c having a controlled surface structure which pore diameter of 2 nm or less, a micro pore vol to 0.4 crrrVg, and BET specific surface area o m²/g is preferable. The micro pore volume is so ion diffusion resistance in the electrode may rise . carbon composite powder mixed with graphiti which causes insufficient thermal uniformity of activation to be difficult for equitable being unlikely to produce the good qualit carbon having a large electric capacity per vo industrially and stably. The carbon fiber of mo by mass decreases density of electrode, and li an electric capacity per volume (F/cm³) .

[0069] The carbon fiber having good thermal a conductivity enhances, heat radiation, and function as buffer for dilatation of electrod the activated carbon particle therewi effectively works to prevent from increasing of electrode at the time of applying voltag

The activated carbon in the invention may in polarizable electrode and electric do capacitor.

[0070] [POLARIZABLE. ELECTRODE and ELECTRIC DO CAPACITOR, and rUSE thereof]

A polarizable electrode in the inventio the activated carbon in the invention, .carbon binder, preferably further comprises the ca

The carbon black used in the polarizabl in the invention may be carbon material known conductor for an electrode of an electrochemic There are mentioned acetylene black, chan in the invention is the same as the above des manner for putting the carbon fiber into the electrode is not only mixing of the carbon activated carbon, the carbon black, and binde compounding of the above carbon composite carbon black and the binder.

[0072] The polarizable electrode may be usual by rolling a compound comprising the activate electric conductor, and the binder; by coatin a slurry comprising the activated carbon, t conductor, binder, and optionally solven collector; and by burning the mixture com activated carbon and un-carbonized resins.

[0073] For example, to the activated carbon po invention having average diameter of 1 to 50 μ the carbon black as electric conductor, and the ¹ as polytetrafluoroethylene (PTFE) , poly fluoride, rubber comprising acrylate monome rubber comprising butadiene monomer unit, to b by blender. To the powder mixture is poured solvent having a boiling point of 200 ⁰C or le powder mixture is swelled. The swelled mixtur into sheet having thickness of approximately mm, which is dried under reduced pressure at ap 100 to 200 ⁰C to be able to obtain the lectrode . ethylacetate, and butylacetate . The prefera solvent is toluene, acetone, ethanol or the l an organic solvent having a boiling point o 200 ⁰C is not preferable, because of remaining solvent in a sheet in the drying at 100 to 2 forming the sheet.

[0075] The sheet is stamped, and a metallic collector is laminated onto the stamped shee an electrode. Two electrodes are lapped in th a separator is interposed between the electro metallic plate is outside, which are electrolyte to be able to obtain an electric d capacitor.

[0076] Any of non-aqueous electrolytic solution electrolytic solution known in the prior employed as the electrolyte in the electric d • capacitor. Also high-molecular solid electr non-aqueous electrolyte, polymer gel elect ionic liquid may be further employed as electrolyte .

As the aqueous electrolytic solution ar sulfuric acid aqueous solution, sodium sulf solution, sodium hydroxide aqueous solution a As non-aqueous electrolytic solution i an electrolytic solution comprising: quarterna salt or uarternar hos honium salt used as with two or more.

[0077] The separator optionally interposed electrodes may be ionic permeable porous sep example, micro-pore polyethylene film, polypropylene film, polyethylene non wov polypropylene non-woven fabric, non-woven f with glass fiber, and the like may be prefe

[0078] The electric double layer capacitor in th may be any of coin type capacitor which a pair o sheets m the state that a separator is interpo the electrode sheets is put in a metallic electrolyte, reel type capacitor which a pair and negative electrodes_^ in the state that a s interposed between the electrodes is rolled u type capacitor which a lot of electrode sheets that a separator is respectively interposed » electrode sheets are piled, and the like.

[0079] The electric double layer capacitor in th can be applied to power supply system. The p system is applied to a power supply system f as automobile and railroad; a power supply syst a power supply system for aircraft; a power su for mobile electronic equipment such as cell mobile information terminal, and mobile calculator; a power supply system for office w suppl s stem for a power generation system s receiver, a memory and a power source, whe receiver receives a set radio wave, the trans a set signal in the memory. The electric d capacitor can be employed as the power sou electronic tag.

[0080] [ADSORBENT]

The activated carbon in the invention can as adsorbent. Specifically, the activated ca preferably employed as gas adsorbent.

There are mentioned as gas adsorba adsorbent in the invention hydrocarbon gas h of carbons such as methane, ethane, ethylene, propane, and butane; hydrogen, natural gas o liquefied petroleum gas, dimethylether, carb hydrogen sulfide, oxygen, nitrogen, nitro (NOx), sulfur oxides (SOx), carbon monoxide, a ¹ mixed gas thereof. As vapor adsorbable by th are mentioned methanol, ethanol, water, aldehydes, low molecular weight hydrocarbo like. In these, for hydrocarbon gas having carbons, preferably gas mainly containing natu adsorbent in the invention has so good adsorpt that the adsorbent in the invention may be fav for natural gas.

[0081] For adsorbing of gas such as natural n i the invention the adsorbent i no more than phase change point (usually mel of phase changeable substance is preferable. of the activated carbon in the invention ma natural gas store tank. The activated car invention is so excellent in packing ability i the like that the natural gas store tank can b as against a conventional tank having the same property. Therefore, the activated carbon in th is favorable for a fuel tank of a natural gas

[0082] Use of the adsorbent in the invention a preventing device from evaporating g canister) . In the view of conservation environment, various provisions against pol carried out on operation of automobile. Ther as one of the provisions that fuel vapor which in fuel tank, float room of evaporator, fuel and the like is adsorbed into the adsorbent in t at the time of stop, and air is introduced into t to desorb the fuel vapor from the adsorbent, fuel vapor to an inlet tube of engine to bur time of run. The activated carbon in .the i favorable for the canister as the adsorbe activated carbon has an excellent adsorption

[0083] The activated carbon in the invention ma to other various uses such as freshness pres ri eness ad ustment of crops as ve etable, used _^m building materials or interior decor activated carbon or adsorbent in the invention uses may be attached to or put into resin sh non-woven fabric or the like, or may be knead

[0084] The following examples a'nd comparative e shown to explain the invention in the co invention is not limited by these examples.

Measurement of each property and pr electrode and electric double layer capaci examples are described as the following:

[0085] [Measurement of Bet Specific Surface Area an Distribution]

BET specific surface area and pore size d were determined by BET method and BJH method nitrogen adsorption isotherm at temperatur nitrogen (77.4 K) as measured with NOVA 1200 QUANTACHROME Instruments.

[0086] [Producing of Electrode]

Into 80 parts by mass of activated carbo average diameter of 10 μm were added 10 parts polytetrafluoroethylene (PTFE) and 10. parts carbon black, which were kneaded and rolled sheet having thickness of 0.5 mm. The sheet into disk having diameter of 20 mm, and the di around the clock to obtain polarizable elec lin of Electric Double La er Ca aci made from fluororubber, 3 is collector aluminum, 4 is insulator comprising TEFLON trade mark) , 5 is vessel made from aluminum, spring made from aluminum, 7 is polarizable ele 8 is separator having thickness of lmm compr fiber.

There was employed the electrolyti produced by TOMIYAMA PURE CHEMICAL INDUST comprising propylene carbonate (PC) as solvent of (CH₃) (C₂H₅)_SNBF₄, ,(C₂Hs)₄NBF₄ as elect comprising ethylene carbonate / di-ethylen (EC/DEC) as solvent and 1 mol/1 of LiBF₄ electrolyte.

[0088] [Measurement of Charge and Discharge Proper

Charge and discharge operation between V at 5 mA was carried out by charge and discharg > system HJ-101SM6 produced by HOKUTO DEN electrostatic capacity per mass (F/g) and an el capacity per volume (F/cm ) of activated car electrodes in an electric double layer cap determined from discharge property curve constant current discharge operation.

[0089] [Permanence]

Two hundred charge and discharge cycle were carried out. A retention rate of the electr was determined to evaluate the permanence. Th Coal pitch having softening point of carbonized by first step at 560⁰C (heating rat holding period of 10 hours at 560 ⁰C) , and by at 630 ⁰C (heating rate of 50 °C/hr, holding hour at 630⁰C) , which was milled to obtain a gr coke. With 1000 g of the coke having an avera of 3.5 μm after milling were mixed 25 g of calciu powder with Henschel Mixer for 60 seconds carbon powder. Potassium hydroxide powder 2.8 carbon powder in mass were mixed with the ca in ball mill, and the mixture was filled into being 300 mm in length, 300 mm in width, 3 mm i and 10 mm in height, made from nickel. The co heated m a batch type activation furnace (s type furnace made by FUJI DEMPA KOGYO Co. Ltd. heating rate of 5 °C/min and holding period of at 400 ⁰C, and then heated at 720 °C as maximum for 15 minutes, in the atmosphere of nit container was cooled to 100 ⁰C or less in the of nitrogen, and then was taken out from the f air. The reaction product was neutralize hydrochloride, and two boiled-acid washing with 0. IN hydrochloride were carried out t metallic impurity. And then two boiled-wat operations were carried out to eliminate residu and metallic impurit . This was dried at 110 as peak within 1.0 to 1.5 nm in a pore diamete activated carbon were dry-compounded 9 % by ma black and 10 % by mass of polytetrafluoroethyl Organic solvent was added to the compounded pow it before kneading, the kneaded powder was roll under reduced pressure at 200 ⁰C to produce a material. A test cell with electrolytic s (C₂Hs)₄NBF₄ / PC under 2.5 V charge and discha had an electric capacity of 41.0 F/g and 23. test cell at cryogenic temperature of -30⁰C ha retention rate of 93 %. Pore size distribu activated carbon was shown in FIG. 2. EXAMPLE 2

An activated carbon was produced by the as Example 1 except that 10 g of calcium hydro g of calcium oxide instead of calcium carbonat with 1000 g of the graphitizable coke hav diameter of 3 μm after milling similar to that 1 with Henschel mixer for 60 seconds.

The activated carbon was 1990 m²/g in surface area, and 0.032 cm³/g in a pore volume as peak within 1.0 to 1.5 nm m a pore diamete activated carbon were dry-compounded 9 % by ma black and 10 % by mass of polytetrafluoroethyl organic solvent was added to the compounded pow it before kneadin the kneaded owder was roll rate of 90 %.

[0093] EXAMPLE 3

Into coal pitch having softening point o added 3 % by rtiass of calcium carbonate, carbonized by first step at 560⁰C (heating rate holding period of 10 hours at 560 ⁰C) , and by at 640 ⁰C (heating rate of 50 °C/hr, holding hour at 640⁰C) , which was milled to obtain a gr coke. Potassium hydroxide powder 3.0 times as mass were mixed with 1000 g of the coke which ha diameter of 3.5 μm after milling in a ball mi mixture was filled into a container being diameter, 3 mm in thickness and 1050 mm in h from nickel.

The container was heated in a continuous furnace (Roller hearth kiln made by NORITAK under the heating rate of 5 °C/mm, holding p minutes at 400 ⁰C, and heated at 740 ⁰C temperature for 15 minutes, in the atmosphere o The container was cooled to 100⁰C or less in the of nitrogen, and then was taken out from the f air. The reaction product was neutralize hydrochloride, and 4 boiled-acid washing oper 0. IN hydrochloride were carried out to elimina impurity. And then 5 boiled-water washing oper carried out to eliminate residual chlorine a surface area, and 0.034 cmVg in a pore volum as peak within 1.0 to 1.5 nm in a pore diamet activated carbon were dry-compounded 9 % by ma black and 10 % by mass of polytetrafluoroethy organic solvent was added to the compounded pow the powder before kneading, the kneaded powde and dried under reduced pressure at 200 ⁰C t electrode material . A test cell with electroly of LiPF₆ / EC / DEC under 2.5 V charge and di an electric capacity of 40.6 F/g and 23.6 F/ cell at cryogenic temperature of -30 ⁰C had retention rate of 85 %. ] EXAMPLE 4

An activated carbon was produced by the as Example 1 except that 20 g of magnesium ox of calcium carbonate were mixed with lO • graphitizable coke having average diameter o milling similar to that in example 1 with Hen for 60 seconds.

The activated carbon was 1520 m²/g in surface area, and 0.022 cm³/g in a pore volum as peak within 1.0 to 1.5 nm in a pore diamet activated carbon were dry-compounded 5 % by m grown carbon fiber (VGCF, produced by SHOWA 4 % by mass of carbon black and 10 % ol tetrafluoroeth lene (PTFE), or anic solve an electric capacity of 42.1 F/g and 26.9 F/ cell at cryogenic temperature of -30 ⁰C had retention rate of 91 %. [0096] COMPARATIVE EXAMPLE 1

An activated carbon was 'produced by the as Example 1 except that 3 g of calcium carbonat with 1000 g of the graphitizable coke hav diameter of 3μm after milling similar to that 1 with Henschel mixer for 60 seconds.

The activated carbon was 2035 m²/g surface area. Into the activated ca dry-compounded 9 % by mass of carbon black and of polytetrafluoroethylene (PTFE), organic added to the compounded powder to swell the po kneading, the kneaded powder was rolled and reduced pressure at 200 ⁰C to produce an > material. Test cell with electrolytic s (CH₃) (C₂Hs)₃NBF₄ / PC under 2.7 V charge and di an electric capacity at 25 ⁰C of 41.7 F/g and the test cell at cryogenic temperature of - capacity retention rate of 62 %. Pore size d of the activated carbon was shown in FIG. 2 [0097] COMPARATIVE EXAMPLE 2

An activated carbon was produced by the as Example 1 except that no alkaline earth co mixed with 1000 g of the graphitizable coke hav of polytetrafluoroethylene (PTFE) , organic added to the compounded powder to swell the po kneading, the kneaded powder was rolled and reduced pressure at 200 ⁰C to produce an material. Test cell with ele'ctrolytic soluti / EC / DEC under 2.5 V charge and discharge had capacity at 25 ⁰C of 37.2 F/g and 22.7 F/ml, t at cryogenic temperature of -30⁰C had a capacit rate of 59 %. Pore size distribution of th carbon was shown m FIG. 2. 8] COMPARATIVE EXAMPLE 3

A commercial activated carbon (MSP-20, THE KANSAI COKE AND CHEMICALS Co. Ltd.) bei activated carbon made of phenol based resin as r was used in the evaluation.

The activated carbon was 2210 m /g in > surface area. Into the activated carbon were 9 % by mass of carbon black and 10 % polytetrafluoroethylene (PTFE), organic solve to the compounded powder to swell the po kneading, the kneaded powder was rolled and reduced pressure at 200 ⁰C to produce an material. Test cell with electrolytic s (C₂H₅) ₄NBF₄ / PC under 2.5V charge and disch electric capacity at 25 ⁰C of 39.2 F/g and 24. test cell at cryogenic temperature of -30⁰C ha [ 0099 ] [TAB . l ]

Tab. 1 alkaline mixing pore vol. earth alkaline of peak metallic earth within 1.0 comp. metallic to 1.5nm comp. [% by mass] [cπf/g]

CaCO₃

Ex. 1 with coke 0.033 2.5

Ca(OH)₂

Ex with coke 1.0 0.032 CaO 1.0

CaCO₃

Ex. 3 with pitch 0 .034 3.0

MgO

Ex. 4 with coke 0 .022 2.0

Comp. CaCO₃ with coke 0 014 Ex. 1 0 3 none

(pitch based

Comp alkaline none 0.013 Ex. 2 activated carbon) none

(phenol based

Comp. alkaline none 0.013 Ex. 3 activated carbon)

[0100] As shown in TAB. 1, when a peak D withi nm m a pore diameter is regulated within the ra to .035 cm³ there can be roduced the acti carbonization step. The resultant was heated a 1 hour in the second carbonization step to ob raw material having a true density of 1.47 obtained coke was crushed into a diameter of 0.

Into 71.5 mg of dnron trioxide a containing element in the 8th group of the 4th added 10 g of water to obtain iron oxide slur iron oxide slurry were added 5.0 g of the ab raw material, and fully mixed to obtain mixe the coke as raw material and iron oxide. Th mixed slurry was dried at 110 ⁰C over nigh compound of the coke and iron oxide.

Into vessel made from nickel and having 40 mm were charged 5 g of the compound of co oxide and 15.7 g of potassium hydroxide (95 vessel put m a batch type furnace for activatio • Air in the furnace was displaced by nitroge temperature increase was begun. While the heated, nitrogen gas with a flow rate of 0. bubbled in water having temperature of 50⁰C to together saturated water vapor into the fur ] In the activation reaction, the tempera furnace was increased to 400 ⁰C at a rate of held at 400 ⁰C for 30 minutes, elevated to 720 of 5.3⁰C/mm and maintained at 720⁰C for 15 min the activation reaction, the furnace was coole iron and nickel attached on the activated c boiled water washing at 100⁰C, filtering and w were repeated -in turn for the activated carb ppm or less of residual chlorine in the activa and the purified activated carbon was dried at night . ] The obtained activated carbon had a B surface area of I960 m²/g, and pore size dist calculated by BJH method shown in FIG.3.

As shown in FIG^ 3, the activated carb peak a within the range of 2.1 to 2.4 nmina por a peak b within the range of 1.7 to 2.1 nm m a po a peak c within the range of 1.4 to 1.7 nm in a po and a peak d within the range of 1.1 to 1.4 n diameter can be found. Area d was 3.90, area and area b was 1.66, supposing that area a, was * the area a, the area b, the area c, and the are enclosed with pore diameter axis and distrib of each peak within the above pore diameter

It is recognized that pore size distrib controlled by addition of dnron tπoxide to raw material in EXAMPLE 5 more effectively than of no metallic compound in COMPARATIVE EXAM

Test cell with electrolytic solution of / PC under 2.7 V charge and discharge at 2 electric ca acity of 21.1 F/cm³, the test cell a atmosphere of nitrogen to carry out carbonization step. The resultant was heated a 1 hour in the second carbonization step to ob raw material having a true density of 1.47 obtained coke was crushed into'a diameter of 0.

Into 62.2 mg of copper oxide as compound element in the 11th group of the 4th period we g of water to obtain copper oxide slurry. Int oxide slurry were added 5.0 g of the above material, and fully mixed to obtain mixed sl coke and copper oxide. The resultant mixed slur at 110 ⁰C over night to obtain compound of t copper oxide.

Into vessel made from nickel and having 40 mm were charged 5 g of the compound of coke oxide and 15.7 g of potassium hydroxide (95 ' vessel put in a batch type furnace for activatio Air in the furnace was displaced by nitroge temperature increase was begun. While the heated, nitrogen gas with a flow rate of 0. bubbled in water having temperature of 50⁰C to together saturated water vapor into the fur ] In the activation reaction, the tempera furnace was increased to 400 ⁰C at a rate of held at 400 ⁰C for 30 minutes, elevated to 720 of 5.3 °C/min and maintained at 720⁰C for 15 min 100 °C dissolved and eliminated metallic impu copper and nickel attached on the activated c boiled water washing at 100⁰C, filtering and w were repeated in turn for the activated carb ppm or less of residual chlorine in the activa and the purified activated carbon was dried at night . The obtained activated carbon had a B surface area of 1707 m²/g, and pore size dist calculated by BJH method shown in FIG.3.

As shown in FIG. 3, the activated carb peak a within the range of 2.1 to 2.4 nm in a por a peak b within the range of 1.7 to 2.1 nm m a po a peak c within the range of 1.4 to 1.7 nm in a po and a peak d within the range of 1.1 to 1.4 n diameter can be found. Area d was 4.41, area and area b was 1.87, supposing that area a was the area a, the area Jb, the area c, and the are enclosed with pore diameter axis and distrib of each peak within the above pore diameter

It is recognized that pore size distrib controlled by addition of copper oxide to the material in EXAMPLE 6 more effectively than of no metallic compound in COMPARATIVE EXAM

Test cell with electrolytic solution of / PC under 2.7 V charge and discharge at 2 Coal based pitch was heated at 500 atmosphere of nitrogen to carry out carbonization step. The resultant was heated a 1 hour m the second carbonization step to ob raw material having a true density of 1.47 obtained coke was crushed into a diameter of 0.

Into 83.2 mg of titanium dioxide a containing element in the 4th group of the 4th added 10 g of water to obtain titanium dioxide s the titanium dioxide slurry were added 5.0 g coke as raw material, and fully mixed to o slurry of the coke as raw material and titani The mixed slurry was dried at 110 ⁰C over nig compound of the coke and titanium dioxide.

Into vessel made from nickel and having 40 mm were charged 5 g of the compound of coke a » dioxide and 15.7 g of potassium hydroxide (95 vessel put in.a batch type furnace for activatio Air in the furnace was displaced by nitroge temperature increase was begun. While the heated, nitrogen gas with a flow rate, of 0. bubbled in water having temperature of 50⁰C to together saturated water vapor into the fur ] In the activation reaction, the tempera furnace was increased to 400 ⁰C at a rate of held at 400 ⁰C for 30 minutes, elevated to 720 Boiled acid washing with 0.1 mol/1 of hydro 100 ⁰C dissolved and eliminated metallic impu titanium and nickel attached on the activated c boiled water washing at 100⁰C, filtering and wa were repeated in turn for the activated carb ppm or less of residual chlorine in the activa and the purified activated carbon was dried at night . ] The obtained activated carbon had a B surface area of 1707 m_//g, and pore size dist calculated by BJH method shown in FIG.3.

As shown in FIG. 3, the activated carb peak a within the range of 2.1 to 2.4 nm in a por a peak b within the range of 1.7 to 2.1 nm in a por a peak c within the range of 1.4 to 1.7 nm in a por a peak d within the range of 1.1 to 1.4 nm in a por ' a peak e within the range of 0.8 to 1.1 nm in a por and a peak f within the range of 0.4 to 0.8 n diameter can be found. Area f was 2.4, area area d was 4.73, area c was 2.21 and area supposing that area a was 1, in which the area b, the area c, the area d, the area e, and the each enclosed with pore diameter axis and d curve of each peak within the above pore diam

It is recognized that pore size distribu controlled b addition of titanium dioxide to of -30⁰C had an electric capacity of ^'23. capacitance retention ratio (= (electric c -30 ⁰C) / (electric capacity at 25 ⁰C) ) wa [0110] COMPARATIVE EXAMPLE 4

A commercial activated 'carbon (MSP-20, THE KANSAI COKE AND CHEMICALS Co. Ltd.) bei activated carbon made of phenol based resin as r was used in the evaluation.

The activated carbon was 2210 m /g in surface area. Into the activated ca dry-compounded 9 % by mass of carbon black and of polytetrafluoroethylene (PTFE), organic added to the compounded powder to swell the po kneading, and the kneaded powder was rolled and reduced pressure at 200 ⁰C to produce an material. Test cell with electrolytic s (C₂H₅)₄NBF₄ / PC under 2.5V charge and disch electric capacity at 25 ⁰C of 39.2 F/g and 2 capacitance retention ratio (= (electric c -30 ⁰C) / (electric capacity at 25 ⁰C) ) was size distribution of the activated carbon was s 3. [ 0111 ] [ TAB . 2 ]

Tab 2

Ex 5 Ex 6

coal coal raw materal for coke pitch pitch added metallic comp Fe₂O₃ CuO (metallic element cone % by mass) 1% O . O peak f 0 4-0 8 ¹ - -

ratio of area pore peak e 0 8-1 1 - - among peak curve, dia peak d 1 1-1 4 3 90 4 41 pore dia axis and Range peak C 1 4-1 7 1 66 1 91 pore dia range (run) peak b 1 7-2 1 1 66 1 87 peak a 2 1-2 4 1 00 1 00

25⁰C 27 7 27 1 elecric capacity (F/cm

-3O⁰C 24 5 23 9 retention ratio (-30 C/25 C) 0

[0112] As shown TAB. 2, carbonization of pi presence of chemical Z containing an element s and copper can revealmgly produce an activa in pore size distribution as calculatedmeas method from N₂~adsorption isotherm at 77,.4 K, h a within the range of 2.1 to 2.4 nm in a por a peak b within the range of 1.7 to 2.1 nm in a por a peak c within the range of 1.4 to 1.7 nm in a por and a peak d within the range of 1.1 to 1.4 n diameter, and having area d of 3.7 to 4.8, ar And carbonization of pitch in the p chemical Z containing an element such as t revealmgly produce an activated carbon, distribution as calculated by BJH me N₂-adsorption isotherm at 77:4K, having a pe the range of 2.1 to 2.4 nm in a pore diamete within the range of 1.7 to 2.1 nm in a pore peak c within the range of 1.4 to 1.7 nm in a por a peak d within the range of 1.1 to 1.4 nm in a por a peak e within the range of 0.8 to 1.1 nm in por a peak f within the range of 0.4 to 0.8 nm in por and having area f of 2.2 to 2.5, area e of 2.3 d of 4.6 to 4.8, area c of 2.1 to 2.3 and ar to 2.1, supposing that area a is 1, in which the area b, the area c, the area d , the area area f are each enclosed with pore diamete distribution curve of each peak within the diameter range. And it can be found out that activated carbon can produce an electric d capacitor having high retention ratio at temperatures . [Measurement of Gas Adsorption]

Adsorption for methane was measured a ranging from normal pressure to 3.5 MPa.

Methane gas was provided into a deaerate before a stable pressure, and the stable pres [0114] EXAMPLE 8

Coal pitch having softening point of carbonized by first carbonization step at 500 rate of 5 °C/hr, holding period of 10 hours and by second carbonization step at 550 ⁰C (h of 50 °C/hr, holding period of 1 hour at 550⁰C, period of 100 hours) , which was milled t graphitizable coke having an average diamete and a true density of 1.45 g/cm³. With lOOOg were mixed 25 g of calcium carbonate powder wi Mixer for 60 seconds to obtain a carbon powder hydroxide 1.6 times as the carbon powder in mas with the carbon powder in a ball mill, and the filled into a container being 300 mm in lengt width, 3 mm in thickness and 10 mm in height nickel .

[0115] The container was heated in a batch type furnace (segmentation type furnace made by KOGYO Co. Ltd.) under a heating rate of 10 °C/m period of 30 minutes at 400 ⁰C, and heated a maximum temperature for 15 minutes, in the at nitrogen. The container was cooled to 100 ⁰C the atmosphere of nitrogen. The container wa from the furnace to obtain a reaction product . T product was neutralized with IN hydrochlor boiled-acid washing operations with 0. IN hy magnetic separator (magnetic power 12000 G) activated carbon having average diameter of

The activated carbon was 1170 m²/g surface area. As shown by curve K in FIG. 4 approximately 1.22 nm in a pore diameter app peak within the range of 1.0 to 1.5 nm in a po was 0.013 cmVg that is 2 % to total pore volum cm³/g. The amount of methane gas adsorpt activated carbon is shown in TAB. 3, and distribution of the activated carbon is show ] EXAMPLE 9

Coal pitch having softening point of carbonized by first carbonization step at 500 rate of 5 °C/hr, holding period of 10 hours and by second carbonization step at 660 ⁰C (h was 50 °C/hr, holding period was 1 hour at ' cooling period from 660 ⁰C to room temperat hours) , which was milled to obtain a graphit having an average diameter of 3.5 μm and a t of 1.51 g/cm³. With 1000 g of the coke were mi calcium oxide powder and 5 g of calcium hyd Henschel Mixer for 60 seconds to obtain a car Potassium hydroxide 2.6 times as the carbon po were mixed with the carbon powder in a ball mi mixture was filled into a container being 300 m 300 mm in width, 3 mm in thickness and 10 mm maximum temperature for 15 minutes, m the at nitrogen. The container was cooled to 100 ⁰C the atmosphere of nitrogen. The container wa from the furnace to obtain a reaction product . T product was neutralized with IN hydrochlor boiled-acid washing operations with 0. IN hy were carried out to eliminate metallic impuri 2 boiled-water washing operations with dist were carried out to eliminate residual ch metallic impurity. This was dried at 110 ⁰C w flow, and passed through filter having mesh magnetic separator (magnetic power 12000 G) activated carbon having average diameter of

The activated carbon was 1810 m²/g i surface area. As shown by curve L in FIG. 4 approximately 1.22 nm in a pore diameter appear > within the range of 1.0 to 1.5 nm in a pore d 0.021 cm³/g that is 24 % to total pore volume cmVg. The amount of methane gas adsorpt activated carbon is shown in TAB. 3, and distribution of the activated carbon is shown [0118] EXAMPLE 10

Into coal pitch having softening point o added 30 g of calcium carbonate, this was ca first carbonization step at 560 ⁰C (heati 5 °C/hr, holding period of 10 hours at 560⁰C) , a Potassium hydroxide 3.0 times as the carbon po were mixed with the coke in a ball mill, and was filled into a container being 600 mm in mm in thickness and 1050 mm in height, made f

[0119] The container was heated in a continuous furnace (Roller hearth kiln made by NORITAK under the heating rate of 5 °C/min, holding p minutes at 400 ⁰C, and heated at 740 ⁰C for and then cooled to 100 ⁰C or less in the at nitrogen. The container was taken out from the obtain a reaction product. The reaction p neutralized with IN hydrochloride, and 3 washing operations with 0. IN hydrochloride w out to eliminate metallic impurity. A boiled-water washing operations with distille carried out to eliminate residual chlorine a » impurity. This was dried at 110 ⁰C with hot ai passed through filter having mesh of 330 a separator (magnetic power 12000 G) to obtai carbon having average diameter of 4.5 μm.

The activated carbon was 2020 m /g i surface area. As shown by curve M in FIG. 4, approximately 1.22 nm in a pore diameter appear within the range of 1.0 to 1.5 nm in a pore d 0.033 cm³/g that is 31 % to total pore volume cm³/g. The amount of methane gas adsorpt was changed to 17 g

The activated carbon was 1570 m²/g surface area. As shown curve N in FIG. 4, no ranging from 1.0 to 1.5 nm in a pore diamete A pore volume at 1.22 nm in a pore diameter was that was 0.008 % to total pore volume being The amount of methane gas adsorption of th carbon was 140 mg/g. COMPARATIVE EXAMPLE 6

A grahitizable coke having average diam was produced by the same manner as EXAMPLE

An activated carbon was produced manner as EXAMPLE 9 except that with 1000 g was not added any alkaline earth metallic co alkali metallic compound (potassium hydrox only, and the mixture was activated.

The activated carbon was 2210 m /g i surface area. As shown by curve O m FIG. 4, no the range of 1.0 to 1.5 nm in a pore diamete r

A pore volume at 1.22nm in a pore diameter was that was 0.9 % to total pore volume being 0.9 amount of methane gas adsorption of the activ is shown in TAB. 3, pore size distribution of th carbon is shown in FIG. 4. [0122] [TAB.3]

Tab.3

alkaline earth BET pore vol. within metallic -1i.0n ₊t.o -1i 5cnm /_/

. . _η -, element cone. total pore vol.

(ppm) (m²/g) _(%)

Ex. 8 9760 1170 ' 2 0

Ex 9 9700 1810 24 0

EX. 10 11650 s 2020 31 0

Comp .

6690 1570 0 008 Ex. 5

Comp.

0 2210 0.9 Ex. 6

[0123] As shown in TAB. 3, it is found that th carbon (Ex.8 to 10) having specific pore struc the highest peak D within the range of 1.0 n m a pore diameter is from 0.012 to 0.050 cm³/g 2 % to 32 % to a total pore volume, has a hi in adsorption of methane gas, though the activ has a small specific surface area. The activ has excellent packing property in vessel such has high ability of gas storage, so the activ can be favorabl em lo ed for adsorbent of EXAMPLE 8, the activated carbon in COMPARATIV has a large specific surface area, which low property.

Claims

[1] An activated carbon having at least one the range of 1.0 nm to 1.5 nm in pore size di wherein the highest peak (peak D) is 0.02 cm³ cm³/g, wherein the pore size distribution is by BJH method from N₂-adsorption isotherm a

[2] The activated carbon according to clai a specific surface area, as measured by BE N₂-adsorption, of 1500 m²/g to 2200 m²/g.

[3] An activated carbon having the highest a peak D within the range of 1.0 nm to 1.5 n the peak D is from 0.012 cm³/g to 0.05 cm³/g 2 % to 32 % to a total pore volume, in pore size d as calculated by BJH method from N₂-adsorpti at 77.4 K.

[4] > The activated carbon according to clai a specific surface area, as measured by BE N₂-adsorption, of 1100 m²/g to 2200 m²/g.

[5] The activated carbon according to any o 1 to 4, having a peak C within the range of 1. nm m pore size distribution.

[6] The activated carbon according to any o 1 to 5, having a peak B within the range of 1. nm m pore size distribution.

[7] The activated carbon according to any o having a peak a within the range of 2. nm in a pore diameter, a peak b within the r nm to 2.1 nm in a pore diameter, a peak c with of 1.4 nm to 1.7 nm in a pore diameter , and a p the range of 1.1 nm to 1.4 nm in a pore dia having area d of 3.7 to 4.8, area c of and area i) of 1.6 to 2.1, supposing that area which the area a, the area b, the area c, and are each enclosed with pore diameter axis and d curve of each peak within the above pore diam [9] An activated carbon, in pore size dist calculated by BJH method from N₂~adsorption 77.4 K, having a peak a within the range of 2. nm in a pore diameter, a peak b within the r nm to 2.1 nm in a pore diameter, a peak c withi ■ of 1.4 nm to 1.7 nm m a pore diameter, a pe the range of 1.1 nm to 1.4 nm m a pore diame e within the range of 0.8 nm to 1.1 nm in a por and a peak f within the range of 0.4 nm to 0.8 diameter, and having area f of 2.2 to 2.5, area e of area d of 4.6 to 4.8, area c of 2.1 to 2.3 an 1.9 to 2.1, supposing that area a is 1, in whi a, the area b, the area c, the area d , the h area f re each enclosed with ore diamet in metallic element concentration of chemical any of elements in the 2nd group, any of elem 3rd to 11th groups of the 4th period, or ele 4th group of the 5th period on periodic tabl a graphitizable coke, activating the graphitizable coke m t of alkali metallic compound, and then washing the activated coke.

[11] A process of making an activated carbon steps of: carbonizing pitch to obtain a graphiti mixing the graphitizable coke with 7000 in metallic element concentration of chemical any of elements in the 2nd group, any of elem

3rd to 11th groups of the 4th period, or ele

4th group of the 5th period on, periodic tabl

» mixture, activating the mixture in the presenc metallic compound, and then washing the activated mixture.

[12] The process of making an activated carbo to claim 10 or 11, in which the graphitizable true density of 1.44 g/cm³ to 1.52 g/cm³.

[13] The process of making an activated carbo to any one of claims 10 to 12, in which th softenin oint of 100 ⁰C or less. to any one of claims 10 to 14, in which the comprises simple substance or compound contain one element selected from the group consistin Mn, Fe, Co, Ni, Cu, and Zr.

[16] The process of making an! activated carbo to any one of claims 10 to 15, in which the comprises simple substance or at least o selected from the group consisting of oxide, chloride, bromide, iodide, fluoride, carbonate, sulfide, sulfate and nitrate.

[17] The process of making an activated carbo to any one of claims 10 to 16, in which the alka compound comprises alkali metallic hydroxid

[18] The process of making an activated carbo to any one of claims 10 to 17, m which the alka compound comprises a compound, containing a element selected from the group consisting o Cs.

[19] A carbon composite powder comprising th carbon according to any one of claims 1 to 9, fiber.

[20] The carbon composite powder according t in which the carbon fiber has pore therein, surface area of 10 m²/g to 50 m²/g, an avera of fiber of 50 nm to 500 nm, and an aspect ra carbon black, and binder.

[23] The polarizable electrode according to which the amount of the carbon fiber is 0.1 % 20 % by mass to that of the activated carbo

[24] The polarizable electrode according to 23, in which the carbon fiber has pore therein, surface area of 10 m²/g to 50 m²/g, an avera of fiber of 50 nm to 500 nm, and an aspect ra 1000.

[25] The polarizable electrode according to claims 21 to 24, in which the binder compris one polymer selected from the group con polytetrafluoroethylene, polyvmylidenefluor comprising acrylate monomer unit, and rubber butadiene monomer unit.

[26] An electric double layer capacitor com > polarizable electrode according to any one o to 25.

[27] The electric double layer capacitor a claim 26, comprising electrolytic solution d least one electrolytic salt selected from consisting of quaternary ammonium salt, lmidazolium salt, quaternary pyndinium quaternary phosphonium salt into organic solve electrolytic cation is 3 A to 15 A in an io according to any one of claims 1 to 9 is appli surface thereof. [31] A power supply system comprising the ele layer capacitor according to claim 26 or 27 [32] A vehicle in which the electric do capacitor according to claim 26 or 27 is em [33] A railroad in which the electric do capacitor according to claim 26 or 27 is em [34] A ship m which the electric double laye according to claim 26 or 27 is employed. [35] An aircraft in which the electric d capacitor according to claim 26 or 27 is em [36] A portable apparatus in which the elec layer capacitor according to claim 26 or 27 i [37] An apparatus for office work in which t double layer capacitor according to claim 2 > employed. [38] A solar power generation system in which t double layer capacitor according to claim 2 employed. [39] A wind power generation system in which t double layer capacitor according to claim 2 employed. [40] A communication apparatus in which t double layer capacitor according to claim 2 employed. hydrocarbon gas having 1 to 4 of carbon ato [44] A preventing device from evaporating g which the adsorbent according to claim 4 employed. [45] A stock tank for natural gas, in which th according to claim 42 or 43 is employed. [46] A natural gas automobile, in which th according to claim 42 or 43 is employed.