KR20230093802A - Method for low-temperature oxidative stabilized pitch and activated carbon by the method - Google Patents

Abstract

The present invention relates to a low-temperature oxidative stabilization method of pitch and activated carbon produced thereby, and to a method for oxidatively stabilizing pitch, comprising: a stabilization step of exposing the pitch to a stabilizer to oxidize an oxygen functional group; A carbonization step of heating and carbonizing the stabilized pitch in an inert atmosphere, and an activation step of producing activated carbon in an activator, water vapor or CO ₂ atmosphere after heating the carbonized pitch in an inert gas atmosphere, wherein the stabilizer includes ozone , Plasma and one of an electron beam beam, and the carbonization step is performed by heating the stabilized pitch to a carbonization temperature of 500 to 1000° C. at a carbonization rate of 5 to 21° C./min, and then at the carbonization temperature for 30 to 120 minutes. While maintaining and carbonizing, in the activation step, the stabilized pitch has an activation rate of 5 to 21 ° C / min and is heated to an activation temperature of 600 to 1000 ° C, and then maintained at the activation temperature for 30 to 120 minutes It is possible to provide a low-temperature oxidation stabilization method of pitch characterized in that it is activated.

Description

Method for low-temperature oxidative stabilized pitch and activated carbon by the method}

The present invention relates to a low-temperature oxidation stabilization method of pitch and activated carbon produced through the method, and more particularly, to a softening point using at least one treatment method among ozone, plasma, and electron beam. It relates to a method for low-temperature oxidation stabilization of pitch, which can produce activated carbon with a high specific surface area that is more economical than conventional pitch-based activated carbon by oxidatively stabilizing low pitch at a low temperature, and an activated carbon produced through the same.

Among the major intermediate raw materials for carbon materials such as anode materials for lithium-ion batteries, carbon electrodes, and carbon fibers used in the industry, pitch is manufactured through the synthesis of coal tar or petroleum-based residue oil, a by-product of the steelmaking process. In general, petroleum-based residue oil has a low content of impurities such as sulfur, nitrogen, and metal compared to coal tar, and has a high advantage as a raw material for carbon materials. has The PFO pitch obtained in this way can be made into activated carbon through stabilization, carbonization, and physical activation processes. First, after a stabilization process in which pitch is oxidized through heat treatment in an air atmosphere, activated carbon is produced through carbonization in an inert atmosphere and then activation of water vapor or CO ₂ .

Since the pore characteristics of pitch-based activated carbon are particularly affected by the crystal structure of pitch, the softening point and stabilization process are very important. In general, the oxidation stabilization process is stably oxidized as the softening point of pitch increases. However, in order to produce pitch having a high softening point, a high temperature and a long synthesis time are required, and the higher the softening point, the higher the ratio of activated carbon produced. It has a limit in that the surface area is lowered.

Therefore, in order to improve the quality, productivity, and economy of pitch-based activated carbon, it is advantageous to utilize pitch with a low softening point. However, since pitch-based carbon with a low softening point contains a large amount of low boiling point materials, in the oxidation stabilization process performed at high temperature, most of the oxygen is oxidized with the low boiling point materials first and removed to gases such as CO, CO ₂ , CH ₄ , so oxidation stabilization There is a problem that the yield is greatly reduced. Therefore, in order to solve the problems of the existing pitch-based activated carbon, a low-temperature stabilization technology of pitch having a low softening point is required.

As a prior art, there is Korean Patent Registration No. 10-1592714 entitled "Apparatus for manufacturing short pitch-based carbon fibers and method for manufacturing the short fibers".

Therefore, in order to solve the above problems, the present invention develops a pitch stabilization technology having a low softening point at a low temperature using highly reactive ozone, plasma, and electron beam, thereby improving the yield and improving productivity and economic feasibility of the pitch at a low temperature. An object of the present invention is to provide an oxidation stabilization method and activated carbon produced through the method.

In order to solve the above problems, a low-temperature oxidation stabilization method of pitch according to an embodiment of the present invention includes a stabilization step of oxidizing an oxygen functional group by exposing the pitch to a stabilizer; A carbonization step of heating and carbonizing the stabilized pitch in an inert atmosphere, and an activation step of producing activated carbon in an activator, water vapor or CO ₂ atmosphere after heating the carbonized pitch in an inert gas atmosphere, wherein the stabilizer includes ozone , Plasma and one of an electron beam beam, and the carbonization step is performed by heating the stabilized pitch to a carbonization temperature of 500 to 1000° C. at a carbonization rate of 5 to 21° C./min, and then at the carbonization temperature for 30 to 120 minutes. While maintaining and carbonizing, in the activation step, the stabilized pitch has an activation rate of 5 to 21 ° C / min and is heated to an activation temperature of 600 to 1000 ° C, and then maintained at the activation temperature for 30 to 120 minutes characterized by activation.

In addition, in the stabilization step, when the stabilizer is the ozone, the pitch is exposed to ozone having a concentration of 10 to 200 mg/L, and maintained at a stabilization temperature of 10 to 110 ° C. for 10 to 120 minutes. to be

In the stabilization step, when the stabilizer is the plasma, the pitch is exposed to the plasma of 100 to 1000 W, and maintained at a stabilization temperature of 10 to 110 ° C. for 10 to 120 minutes.

In the stabilization step, when the stabilizer is the electron beam, the pitch is exposed to the electron beam beam of 300 kGy to 5000 kGy, but maintained at a stabilization temperature of 10 to 110 ° C. for 10 to 120 minutes. Characterized in that.

In addition, a specific surface area of 700 to 3300 m ² /g, a total pore volume of 0.25 to 1.9 cm ³ /g, a micropore volume of 0.26 to 1.17 cm ³ /g, and a mesopore volume of 0.01 to 0.9 cm ³ /g It is possible to provide activated carbon containing a (mesopore) volume.

According to the present invention, the oxidation stabilization method of pitch and the activated carbon produced through the method can stably enable oxidation stabilization of pitch having a low softening point.

In addition, productivity can be improved by reducing the temperature and time of the step of oxidatively stabilizing the pitch.

1 is a flow chart of a low-temperature oxidation stabilization method of pitch according to an embodiment of the present invention.

Hereinafter, the description of the present invention with reference to the drawings is not limited to specific embodiments, and various transformations may be applied and various embodiments may be applied. In addition, the content described below should be understood to include all conversions, equivalents, or substitutes included in the spirit and scope of the present invention.

In the following description, terms such as first and second are terms used to describe various components, and are not limited in meaning per se, and are used only for the purpose of distinguishing one component from another.

Like reference numbers used throughout this specification indicate like elements.

Singular expressions used in the present invention include plural expressions unless the context clearly dictates otherwise. In addition, terms such as "include", "include" or "have" described below are intended to designate that features, numbers, steps, operations, components, parts, or combinations thereof described in the specification exist. should be construed, and understood not to preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

Hereinafter, an embodiment of the present invention will be described in detail with reference to FIG. 1 attached.

1 is a flowchart of a method for oxidation stabilization of pitch according to an embodiment of the present invention.

The low-temperature oxidation stabilization method of pitch according to an embodiment of the present invention is a method for oxidatively stabilizing petroleum pitch more stably, and may include a stabilization step (S10), a carbonization step (S20) and an activation step (S30). there is.

Here, the pitch may be used, such as petroleum-based pitch synthesized with PFO, but is not limited thereto and may be applicable to all commonly used coal-based pitches.

In addition, it is most preferable that the pitch has a particle size of 18 to 600 mesh, but is not limited thereto.

The stabilization step (S10) is to expose the pitch to a stabilizer to oxidize the oxygen functional group of the pitch, thereby establishing the crystal structure of the pitch.

In this case, the stabilizer may be one of ozone, plasma, and electron beam, and the stabilization step (S10) may be performed differently as follows.

First, if the stabilizer is ozone, the stabilization step (S10) may expose the pitch to ozone having a concentration of 10 to 200 mg/L. In addition, the stabilization step (S10) may be performed by maintaining the pitch exposed to ozone at a stabilization temperature of 10 to 110 ° C. for 10 to 120 minutes.

At this time, in the stabilization step (S10), it is most preferable to expose to ozone having a concentration of 10 to 100 mg/L, but is not limited thereto.

In addition, the stabilization step (S10) is most preferably performed by maintaining at a stabilization temperature of 15 to 70 ° C. for 10 to 45 minutes, but is not limited thereto.

Next, when the stabilizer is plasma, in the stabilization step (S10), the pitch may be exposed to plasma having a calorific value of 100 to 1000 W. In addition, the stabilization step (S10) may be performed by maintaining the pitch exposed to the plasma at a stabilization temperature of 10 to 110 ° C. for 10 to 120 minutes.

At this time, the stabilization step (S10) is most preferably performed by maintaining the pitch at a stabilization temperature of 15 to 70 ° C. for 10 to 45 minutes after exposing the pitch to plasma, but is not limited thereto.

Finally, if the stabilizer is an electron beam, the stabilization step (S10) may expose the pitch to an electron beam having an absorbed dose of 300 to 5000 kGy. In addition, the stabilization step (S10) may be performed by maintaining the pitch exposed to the electron beam at a stabilization temperature of 10 to 110 °C for 10 to 120 minutes.

At this time, the stabilization step (S10) is most preferably performed by exposing the pitch to an electron beam having an absorbed dose of 300 to 3000 kGy and then maintaining the pitch at a stabilization temperature of 15 to 70 ° C. for 10 to 45 minutes, but is not limited thereto. .

On the other hand, in the stabilization step (S10), when the pitch is stabilized below the lower limit in each stabilization condition, pitch stabilization is not properly performed, so that melting and pore formation are not properly performed in the carbonization and activation steps. there is.

In addition, in the stabilization step (S10), when the pitch is stabilized by exceeding the upper limit in each stabilization condition, a stress difference between the surface and the inside occurs due to the formation of an oxide film on the surface due to the rapid oxygen diffusion rate, resulting in cracks. In the case of peroxidation, a problem in which the pitch is completely burned may occur.

In this way, the stabilization step (S10) may establish the crystal structure of the pitch by oxidatively stabilizing the pitch according to the conditions described above according to the stabilizer.

The carbonization step (S20), which is the next step, is a step of heating and carbonizing the stabilized pitch from the stabilization step (S10).

More specifically, the carbonization step (S20) may be performed by heating the stabilized pitch to a carbonization temperature of 500 to 1000° C. at a carbonization rate of 5 to 21° C./min, and then maintaining the carbonization temperature for 30 to 120 minutes. there is.

At this time, the carbonization step (S20) is most preferably performed in an inert gas atmosphere such as N ₂ , He, Ar, etc., but is not limited thereto.

The most preferred carbonization step (S20) may be performed by heating the stabilized pitch to a carbonization temperature of 600 to 900 ° C with a carbonization rate of 6 to 15 ° C / min, and then maintaining the carbonization temperature for 55 to 105 minutes. Not limited.

At this time, in the carbonization step (S20), when the carbonization temperature is less than 500 ° C., it is not easy to control the pore structure in the activation process due to low crystallinity due to the low carbonization temperature, and when it exceeds 1000 ° C., pore development occurs due to high crystallinity. Difficult problems can arise.

In addition, in the carbonization step (S20), if the carbonization temperature is less than 30 minutes, the crystal grains are not fixed due to the short carbonization time, and if it exceeds 120 minutes, the process cost may increase due to the long process time, which is not preferable .

In this way, the pitch is carbonized through the carbonization step (S20) as described above, so that the crystal grains are fixed and the pore structure can be easily controlled.

The last step, the activation step (S30), is a step of heating the carbonized pitch in an inert gas atmosphere and then activating it using water vapor. Here, the inert gas may include N ₂ , He, Ar, and the like, and most preferably N ₂ , but is not limited thereto.

In addition, water vapor may be replaced with CO ₂ , O ₂ , Air, etc., but is not limited thereto.

In this activation step (S30), the carbonized pitch may be heated to an activation temperature of 600 to 1000° C. with an activation rate of 5 to 21° C./min in an inert gas atmosphere. Thereafter, the activation step (S30) may be performed while blocking the inert gas, supplying water vapor at the activation temperature, and maintaining it for 20 to 120 minutes.

The most preferred activation step (S30) may be performed by heating the carbonized pitch to an activation temperature of 600 to 1000 ° C with an activation rate of 6 to 15 ° C / min, and then maintaining it at the activation temperature for 60 to 120 minutes. Not limited.

At this time, when the activation step (S30) is performed under conditions below the lower limit, low pore characteristics of the pitch-based activated carbon may appear, and when performed under conditions exceeding the upper limit, productivity and economics are significantly lowered due to low yield, etc. this can happen

Accordingly, the low-temperature oxidation stabilization method of pitch according to the present invention introduces various oxygen functional groups on the surface through the stabilization step (S10), carbonization step (S20) and activation step (S30) to provide oxidation-stabilized activated carbon. can

The activated carbon thus prepared has a specific surface area of 700 to 3300 m ² /g, a total pore volume of 0.25 to 1.9 cm ³ /g, a micropore volume of 0.26 to 1.17 cm ³ /g, and a micropore volume of 0.01 to 0.9 cm ³ /g of mesopore volume.

Hereinafter, the present invention will be described in more detail by examples.

However, the following examples are only to illustrate the present invention, and the content of the present invention is not limited by the following examples.

[Experimental Example 1]

[Example 1]

In order to analyze the effect of the stabilization step, in which ozone is the stabilizer, on the crystal structure of pitch, the pitch with a low softening point was maintained at 25 ° C for 15 minutes, and the pitch was stabilized at an ozone concentration of 10 mg / L, followed by elemental analysis. and the results are shown in Table 1.

[Example 2]

Compared to Example 1, the only difference was that the ozone concentration was flowed by 20 mg/L instead of 10 mg/L, but the rest of the process was the same.

[Example 3]

Compared to Example 1, the only difference was that the ozone concentration was flowed by 30 mg/L instead of 10 mg/L, but the rest of the process was the same.

[Example 4]

Compared to Example 1, the only difference was that the stabilizer used plasma instead of ozone and irradiated with a calorific value of 300W instead of ozone concentration of 10mg/L, but the rest of the process was the same.

[Example 5]

Compared to Example 4, the only difference was that the calorific value was irradiated by 400W instead of 300W, but the rest of the process was the same.

[Example 6]

Compared to Example 4, the only difference was that the calorific value was irradiated by 500W instead of 300W, but the rest of the process was the same.

[Example 7]

Compared to Example 1, the only difference was that the stabilizer used an electron beam instead of ozone and irradiated with an absorbed dose of 1000 kGy instead of ozone concentration of 10 mg/L, but the rest of the process was the same.

[Example 8]

Compared to Example 7, the only difference was that the absorbed dose was irradiated by 2000 kGy instead of 1000 kGy, but the rest of the process was the same.

[Example 9]

Compared to Example 7, the only difference was that the absorbed dose was irradiated by 3000 kGy instead of 1000 kGy, but the rest of the process was the same.

[Comparative Example 1]

Compared to Example 1, the oxidation stabilization step using ozone, plasma, and electron beam was not performed, and the temperature was raised to 240 °C at a rate of 1 °C per minute and maintained for 90 minutes, except that the oxidation stabilization was performed, and the rest of the processes were the same. made it

division Elemental analysis (at%) C H O N As-received 93.38 3.05 1.12 2.11 Ozone oxidation stabilization Example 1 83.51 4.02 9.94 0.10 Example 2 83.49 3.95 10.01 0.13 Example 3 82.48 3.81 10.99 0.30 Plasma oxidation stabilization Example 4 84.36 4.06 10.04 0.10 Example 5 84.34 3.99 10.11 0.13 Example 6 83.32 3.85 11.10 0.31 Electron Beam Oxidation Stabilization Example 7 85.21 4.10 10.14 0.10 Example 8 85.19 4.03 10.21 0.13 Example 9 84.16 3.89 11.21 0.31 Comparative Example 1 91.53 5.22 2.31 0.54

According to Table 1, pitch stabilized using ozone increases oxygen (O) compared to untreated carbon as the concentration increases. increased. On the other hand, a tendency for carbon (C) to decrease was observed, which was confirmed by the fact that the oxygen functional groups increased as the carbon structure was destroyed on the carbon surface as the amount of oxygen introduced increased as the concentration of ozone increased on the surface of the pitch.

In addition, it was confirmed that the pitch stabilized using plasma and electron beam increased the oxygen content in the pitch and decreased the carbon and hydrogen content as the irradiation amount increased.

These results indicate that carbon and hydrogen atoms are released in the oxidation stabilization process after oxygen penetrates the pitch, and the existing molecules are converted into aromatic compounds through polycondensation.

[Experimental Example 2]

[Example 10]

In the oxidation stabilization method of pitch in which the stabilizer is ozone (Example 1), 3 g of pitch stabilized at an ozone concentration of 30 mg / L is transferred to an alumina crucible, charged into a reactor made of SUS, and N ₂ ( 99.999%) gas was filled at a flow rate of 300 cc/min. The reactor was heated up to 900 °C at a heating rate of 10 °C/min, then N ₂ gas was shut off, and steam was supplied at a flow rate of 0.5 cc/min to activate _the reactor for an activation time of 20 minutes. Oxidation-stabilized activated carbon was prepared using ozone by natural cooling below.

[Example 11]

Compared to Example 10, the only difference was that the activation time was activated for 30 minutes instead of 20 minutes, and the rest of the process was the same.

[Example 12]

Compared to Example 10, the only difference was that the activation time was activated for 40 minutes instead of 20 minutes, and the rest of the process was the same.

[Example 13]

Compared to Example 10, the only difference was that the activation time was activated for 50 minutes instead of 20 minutes, and the rest of the process was the same.

[Example 14]

Compared to Example 10, the only difference was that the activation time was activated for 60 minutes instead of 20 minutes, and the rest of the process was the same.

[Example 15]

Compared to Example 10, the only difference was that the activation time was activated for 70 minutes instead of 20 minutes, and the rest of the process was the same.

[Example 16]

Compared to Example 10, the only difference was that the stabilizer used plasma instead of ozone and the plasma heat generation amount of 400 W was used, but the rest of the process was the same.

[Example 17]

Compared to Example 16, the only difference was that the activation time was activated for 30 minutes instead of 20 minutes, and the rest of the process was the same.

[Example 18]

Compared to Example 16, the only difference was that the activation time was activated for 40 minutes instead of 20 minutes, and the rest of the process was the same.

[Example 19]

Compared to Example 16, the only difference was that the activation time was activated for 50 minutes instead of 20 minutes, and the rest of the process was the same.

[Example 20]

Compared to Example 16, the only difference was that the activation time was activated for 60 minutes instead of 20 minutes, and the rest of the process was the same.

[Example 21]

Compared to Example 16, the only difference was that the activation time was activated for 70 minutes instead of 20 minutes, and the rest of the process was the same.

[Example 22]

Compared to Example 10, the only difference was that the stabilizer used an electron beam instead of ozone and an electron beam irradiation of 3000 kGy, but the rest of the process was the same.

[Example 23]

Compared to Example 22, the only difference was that the activation time was activated for 30 minutes instead of 20 minutes, and the rest of the process was the same.

[Example 24]

Compared to Example 22, the only difference was that the activation time was activated for 40 minutes instead of 20 minutes, and the rest of the process was the same.

[Example 25]

Compared to Example 22, the only difference was that the activation time was activated for 50 minutes instead of 20 minutes, and the rest of the process was the same.

[Example 26]

Compared to Example 22, the only difference was that the activation time was activated for 60 minutes instead of 20 minutes, and the rest of the process was the same.

[Example 27]

Compared to Example 22, the only difference was that the activation time was activated for 70 minutes instead of 20 minutes, and the rest of the process was the same.

[Comparative Example 2]

Compared to Example 10, the oxidation stabilization step using ozone, plasma, and electron beam was not performed, and the temperature was raised to 240 ° C at a rate of 1 ° C per minute and maintained for 90 minutes, except that oxidation stabilization was performed, and the rest of the processes are the same. made it

The specific surface area, total pore volume, micropore (diameter less than 2 nm) volume, and mesopore (diameter 2 nm to 50 nm) volume of the activated carbon prepared in Examples 10 to 27 were measured and shown in Table 2 below.

Yield: The change in activated carbon mass compared to the precursor used was measured in percentile.

Specific surface area: Relative pressure (P/P ₀ ) at 77K using an isothermal adsorption device (BELSORP-max, BEL JAPAN, Japan) after degassing for 6 hours while maintaining the residual pressure below 10 ^-3 torr at 573K The specific surface area and pore volume were calculated by measuring the adsorption amount of nitrogen (N ₂ ) gas.

division S _BET
(m ² /g) V _Total
(cm ³ /g) V _Micro
(cm ³ /g) V _Meso
(cm ³ /g) transference number(%) Ozone oxidation stabilization Example 10 840 0.33 0.32 0.01 55 Example 11 1250 0.50 0.47 0.03 45 Example 12 1670 0.69 0.63 0.06 38 Example 13 1980 0.86 0.74 0.12 26 Example 14 2630 1.34 0.85 0.49 15 Example 15 3240 1.86 1.16 0.88 8 Plasma oxidation stabilization Example 16 760 0.30 0.29 0.01 61 Example 17 1130 0.45 0.42 0.03 50 Example 18 1500 0.62 0.57 0.05 42 Example 19 1780 0.77 0.67 0.11 29 Example 20 2370 1.21 0.77 0.44 17 Example 21 2920 1.67 1.04 0.79 9 Electron Beam Oxidation Stabilization Example 22 710 0.28 0.27 0.01 63 Example 23 1060 0.43 0.40 0.03 52 Example 24 1420 0.59 0.54 0.05 44 Example 25 1680 0.73 0.63 0.10 30 Example 26 2240 1.14 0.72 0.42 17 Example 27 2750 1.58 0.99 0.75 10 Comparative Example 2 1370 0.59 0.51 0.07 43

Referring to Table 2, it can be seen that the specific surface area of the activated carbon prepared in Examples 10 to 27 has a range of 710 to 3240 m ² /g, and the mesoporous rate is 0 to 88%, indicating a high mesoporous rate. can know that

In addition, it was confirmed that the specific surface area and pore characteristics of the pitch-based activated carbon stabilized by oxidation using ozone, plasma, and electron beam were superior to those of the activated carbon prepared by the conventional method.

In addition, it was confirmed that the ozone oxidation-stabilized activated carbon had the best pore characteristics. Through this, it is judged that the ozone oxidation stabilization method, which is a gas-phase oxidation method, is more advantageous in terms of oxidation stabilization than the electrochemical oxidation methods, such as plasma and electron beam oxidation stabilization methods.

In addition, it was determined that the oxidative stabilization method of the present invention exhibits a higher yield and excellent pore characteristics than general oxidative stabilization methods despite a short oxidative stabilization time.

The embodiments of the present invention described above can be implemented by various substitutions, modifications, and changes without departing from the technical spirit of the present invention, and such implementation can be performed by experts in the technical field to which the present invention belongs from the description of the above-described embodiments. that can be easily implemented.

Claims (5)

In the method of oxidatively stabilizing pitch,
A stabilization step of oxidizing the oxygen functional group by exposing the pitch to a stabilizer;
A carbonization step of carbonizing the stabilized pitch by heating it in an inert atmosphere, and
Including an activation step of producing activated carbon in an activating agent water vapor or CO ₂ atmosphere after heating the carbonized pitch in an inert gas atmosphere,
The stabilizer,
one of ozone, plasma and electron beam;
In the carbonization step,
The stabilized pitch has a carbonization rate of 5 to 21 ℃ / min and is heated to a carbonization temperature of 500 to 1000 ℃, and then maintained at the carbonization temperature for 30 to 120 minutes and carbonized,
In the activation step,
Low-temperature oxidation stabilization of pitch, characterized in that the stabilized pitch has an activation rate of 5 to 21 ℃ / min and is heated to an activation temperature of 600 to 1000 ℃, and then maintained at the activation temperature for 30 to 120 minutes and activated method.
According to claim 1,
The stabilization step is
When the stabilizer is the ozone,
Low-temperature oxidation stabilization method of pitch, characterized in that the pitch is exposed to ozone having a concentration of 10 to 200 mg / L, and maintained at a stabilization temperature of 10 to 110 ° C. for 10 to 120 minutes.
According to claim 1,
The stabilization step is
When the stabilizer is the plasma,
Low-temperature oxidation stabilization method of pitch, characterized in that the pitch is exposed to the plasma of 100 to 1000 W, and maintained at a stabilization temperature of 10 to 110 ° C. for 10 to 120 minutes.
According to claim 1,
The stabilization step is
When the stabilizer is the electron beam,
Low-temperature oxidation stabilization method of pitch, characterized in that the pitch is exposed to the electron beam of 300 kGy to 5000 kGy, and maintained at a stabilization temperature of 10 to 110 ° C. for 10 to 120 minutes.
The activated carbon produced by the method of any one of claims 1 to 4,
700 to 3300 m ² /g specific surface area, 0.25 to 1.9 cm ³ /g total pore volume, 0.26 to 1.17 cm ³ /g micropore volume and 0.01 to 0.9 cm ³ /g mesopore volume ) activated carbon containing volume.

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