WO2003033135A1

WO2003033135A1 - Activated carbon fiber for the removal of organochlorine compounds

Info

Publication number: WO2003033135A1
Application number: PCT/JP2002/009676
Authority: WO
Inventors: Atsushi Matsumoto; Tatsuo Katayama; Takeshi Maeda
Original assignee: Ad'all Co., Ltd.; Unitika Ltd.; Osaka Gas Chemicals Co., Ltd.
Priority date: 2001-09-21
Filing date: 2002-09-20
Publication date: 2003-04-24
Also published as: JPWO2003033135A1

Abstract

The invention provides an activated carbon fiber which exhibits effective adsorptive removal performance against organochlorine compounds contained in fed water, that is, an activated carbon fiber for the adsorptive removal of organochlorine compounds, characterized in that the pore distribution as determined by αs analysis on the basis of the argon adsorption isotherm at an liquid argon temperature satisfies the following three requirements: (1) the specific surface area of micropores is 700m2/g or above, (2) the specific surface area of mesopores is 30m2/g or above, and (3) the total volume of mesopores accounts for 10 to 70 % of the total volume of the all the pores.

Description

Specification

Activated carbon fiber for removing organic chlorine compounds

Technical field

The present invention relates to an activated carbon fiber useful as an adsorbent for removing an organic chlorine-based compound.

Background technology

Recently, the quality of tap water has been deteriorating due to eutrophication and other reasons. For example, it has been confirmed that raw water contains trichloromethane, which has a risk of carcinogenicity, and organic chlorine compounds such as trichloroethylene and methylene dichloride. For this reason, attempts have been made to adsorb and remove the above-mentioned organochlorine compounds by treating raw water with activated carbon in water purification equipment such as rapid filtration equipment and chlorination equipment.

Activated carbon used in such a water supply facility is a carbon material with a porous structure with many pores developed, and its adsorption performance is not determined only by the size of the pore volume, but by the size of the molecule to be adsorbed. And the size of the pore diameter. For example, in general, activated carbon having a large pore diameter has a small total adsorption capacity of organochlorine compounds, but is preferably used for removal of water by adsorption and suitable for regeneration of activated carbon. Conversely, activated carbon with a small pore size has a large total adsorption capacity for organochlorine compounds, but does not have good water adsorption and removal performance.

The pore size and pore size distribution of activated carbon often depend on the type of raw material (for example, coconut shell, sawdust, and carbonaceous raw materials such as coal) or the activation method. When wood-based raw materials such as shells and sawdust are used, only activated carbon with a small pore diameter can be obtained. On the other hand, when coal-based raw materials are used, only activated carbon with a large pore diameter can be obtained. For this reason, it is difficult to obtain an activated carbon having a high total adsorption capacity as well as excellent water adsorption and removal performance of organic chlorine compounds.

In order to obtain activated carbon fibers with both large and small pore diameters, for example, a metal is added to coal tar pitch, which is the raw material, and it is produced through normal spinning, infusibilization, activation, and natural cooling steps There is also a way to do it. However, with this method, although the size of the pore diameter can be formed, the size of the mesopores varies from production lot to production lot. Activated carbon with a large pore size and activated carbon with a small pore size are expressed in terms of their average pore size. The average pore size is generally calculated by pore distribution analysis by nitrogen adsorption. However, in nitrogen adsorption, due to the molecular size of nitrogen, almost no multi-layer adsorption of nitrogen occurs in the ultra micropores based on the IUPAC standard. For this reason, the conventional adsorptive removal performance of the substance to be adsorbed is determined by analyzing the pores of Ultramik mouth as somewhat inaccurate pore size and pore volume value, And pore volume values. As a result, erroneous adsorption performance evaluation is often performed. For example, when performance is evaluated by a water breakthrough test, the difference between the equilibrium adsorption capacity calculated from the breakthrough curve and the micropore volume becomes large, which adversely affects the accuracy of the adsorption performance analysis.

Further, a method of performing pore distribution analysis by argon adsorption or the like at the temperature of liquid argon can be considered, but the calculation means used for the analysis is often a t-plot method. In the t-plot, the presence of mesopores causes extra adsorption by multi-layer adsorption due to capillary condensation and shifts to the upper side of the adsorption isotherm graph. For this reason, the t-plot method is not suitable for analyzing micropores. (Reference: “Carbon Glossary” edited by the Carbon Materials Society of Japan, Rikibon Glossary Editing Committee, published by Agne Shofusha on October 5, 2000) , P. 240, and for a description of the t-plotting method, see "New Edition Activated Carbon", edited by Yuzo Sanada, Motoyuki Suzuki, edited by Fujimoto, Kodansha, published March 1, 1992, pages 26-29).

Disclosure of the invention

A main object of the present invention is to provide an activated carbon fiber exhibiting an effective adsorption and removal performance for adsorbing organic chlorine compounds through water. In particular, for activated carbon fibers with large and small pore diameters in the ratio determined by artificial post-activation treatment, the pore diameters and pore volume values of the micropores and mesopores are analyzed in detail, It is another object of the present invention to provide an activated carbon fiber suitable for removing organic chlorine-based compounds by specifying the total acidic functional group content of the activated carbon fiber.

The present inventor has conducted intensive studies in view of the problems of the prior art, and as a result, has found that an activated carbon fiber having a specific structure can achieve the above object, and has completed the present invention. That is, the present invention relates to the following activated carbon fiber for removing an organic chlorine-based compound.

1. Activated carbon fiber used to adsorb and remove organochlorine compounds. In the pore distribution determined by as analysis from the argon adsorption isotherm at the temperature of liquid argon,

(1) The specific surface area of the micropore is 700 m ² Zg or more,

(2) the specific surface area of the mesopores is 30 m ² Zg or more,

(3) The activated carbon fiber for removing organic chlorine-based compounds, wherein the mesopores have a pore volume of 10% to 70% of the total pore volume.

2. The activated carbon fiber for removing an organic chlorine-based compound according to the above item 1, wherein the total amount of acidic functional groups is 0.2 mmo1 or less.

3. A method for producing an activated carbon fiber for removing an organic chlorine-based compound,

(A) melt activated spinning of the activated carbon precursor, infusibilizing treatment, and activation treatment to obtain activated carbon fiber; and

(Mouth) In the pore distribution obtained by s analysis from the argon adsorption isotherm at the liquid argon temperature of the obtained activated carbon fiber,

(1) The specific surface area of the micropore is 700 m ² Zg or more,

(2) The specific surface area of the mesopores is 3 Om ² Zg or more,

(3) Step of selecting activated carbon fibers having a mesopore pore volume of 10% to 70% of the total pore volume

The manufacturing method characterized by having.

4. A method for selecting activated carbon fibers for removing organic chlorine-based compounds,

In the pore distribution obtained by the as analysis from the argon adsorption isotherm at the liquid argon temperature of the activated carbon fiber,

(1) The specific surface area of the micropore is 700 m ² Zg or more,

(2) The specific surface area of the mesopores is 3 On ^ Zg or more,

(3) A method characterized in that activated carbon fibers having a mesopore pore volume of 10% or more and 70% or less of the total pore volume are selected as activated carbon fibers for removing organic chlorine-based compounds.

'Law. 5. A method for adsorbing and removing an organochlorine compound using activated carbon fiber, wherein the activated carbon fiber has a pore distribution determined by an s-analysis from an argon adsorption isotherm at a liquid argon temperature.

(1) a specific surface area of micropores 7 0 0 m ² Z g or more,

(2) the specific surface area of the mesopores is 30 m ² Zg or more,

(3) A method for removing an organochlorine compound, wherein the pore volume of mesopores is 10% or more and 70% or less of the total pore volume.

6. The removal method according to the above item 5, wherein the organic chlorine compound is at least one of trihalomethane, trichloroethylene and methylene dichloride.

7. The activated carbon fiber for removing organic chlorine-based compounds according to the above item 1, wherein the pores at the mouth of the mouth have a diameter of less than 20 A.

8. The activated carbon fiber for removing organic chlorine-based compounds according to the above item 1, wherein the mesopores have a diameter of not less than 20 A and less than 500 A.

9. The activated carbon fiber for removing an organic chlorine-based compound according to the above item 1, wherein the organic chlorine-based compound is at least one of trihalomethane, trichloroethylene and dichloromethane.

Item 2. The activated carbon fiber for removing an organic chlorine-based compound according to the above item 1, wherein the total amount of the 10.OH group, 00-11 group and {0} = 〇 group is 0.2 mmol or less.

11. The activated carbon fiber for removing organic chlorine-based compounds according to the above item 1, which is obtained from an activated carbon precursor mixture containing an organometallic compound.

1 2. The activated carbon fiber for removing organic chlorine-based compounds according to the above item 1, which is obtained from an activated carbon precursor mixture containing at least one kind of organometallic compound of an iron compound, an iron compound and a magnesium compound.

1 3. A method for removing organic chlorine-based compounds in water to be treated by passing the water to be treated through a tubular body filled with activated carbon fibers according to the above item 1.

Hereinafter, the present invention will be described in detail. '

1. Activated carbon fiber for removing organic chlorine compounds

The activated carbon fiber for removing an organochlorine compound of the present invention is an activated carbon fiber used for adsorbing and removing an organochlorine compound, From the argon adsorption isotherm at the liquid argon temperature,

(1) The specific surface area of the micropore is 70

That's it,

(2) The specific surface area of the mesopores is 3 Orr ^ Zg or more,

(3) The mesopores have a pore volume of 10% to 70% of the total pore volume.

The micropore has a specific surface area of 700 m ² Zg or more (preferably 750 m ² Zg or more) in as analysis by argon adsorption at liquid argon temperature. When the specific surface area is less than 700 m ² / g, the total adsorption capacity of the substance to be adsorbed in the water adsorption becomes small. The micropore in the present invention refers to a pore having a diameter of less than 2 OA, and includes an ultramicropore.

The mesopores have a specific surface area of 30 m ² / "g or more (preferably 100 m ² Zg or more) as analyzed by argon adsorption at the temperature of liquid argon. If this specific surface area is less than 3 Om ² Zg, The mesopores in the present invention mean pores having a diameter of 2 OA or more and less than 50 OA. The pore volume (volume ratio) of mesopores in as analysis by argon adsorption at the temperature of liquid argon is 10% or more and 70% or less (preferably 20% or more and 60% or less) of the total pore volume. If the pore volume is less than 10%, it becomes difficult to effectively remove the adsorbed substance by water absorption, and if the pore volume exceeds 70%, The total adsorption capacity of the substance to be adsorbed is reduced.

The mesopore volume and the micropore volume of the activated carbon fiber of the present invention can be calculated from the adsorption isotherm data in the device program by adsorbing argon gas at the temperature of liquid argon using an automatic gas adsorption measuring device (manufactured by Quantachrome). Detailed calculations can be made automatically by ^ -analysis. The specific surface area of mesopores and micropores can be calculated in the same manner.

The above-mentioned as analysis is a method of obtaining an as-plot obtained as a standard adsorption isotherm using a type II adsorption isotherm of a solid whose surface structure is well understood. The as-plot itself can be determined according to a known method (for example, the reference “carbon terminology”). ), Edited by the Editorial Committee of the Glossary of Terms by the Society of Carbon Materials, published by Agune Shofusha on October 5, 2000, page 10). The a s-plot is advantageous in that the average error of the adsorption amount is smaller than that of the normal BET analysis.

The activated carbon fiber of the present invention preferably has a total acidic functional group content of 0.211111101 or less (particularly 0.17 mmo1 or less). By setting the total amount of the acidic functional groups to 0.2 mmol or less, it becomes possible to further increase the total adsorption capacity of the substance to be adsorbed in the flow-through adsorption. The acidic functional groups are mainly OH groups, COOH groups and C〇C = O groups.

The total amount of acidic functional groups in the activated carbon fiber of the present invention is determined by a Boehem titration method. The Boehem titration method is a widely used analytical method for activated carbon and the like. It classifies and quantifies the acidic oxygen functional groups on the activated carbon surface by acid salt group titration (for example, see Angew. Chem. , Intern. Ed. Engl ·, 5, 533 (1966)]. The analysis method is as follows: First, the sample activated carbon fiber is dried at 105 ° C for 2 hours, weighed to 0.99 to 1.01 g, and immersed in 50 ml of Arikari aqueous solution. Three kinds of aqueous solution of sodium hydroxide, sodium hydroxide, sodium carbonate and sodium hydrogencarbonate are used. This immersion liquid is sealed, and after standing for 24 hours, the activated carbon fiber is removed by filtration, 10 ml of the immersion liquid is weighed with a pipet, and titrated with 0.1 mol of hydrochloric acid. Perform the titration three times and use the average value. From the difference between this value and the titration value of the blank, the amount of surface acidic oxygen functional groups of the activated carbon fiber is calculated.

From the surface acidic oxygen functional groups that react with the type of alkaline, the difference in the amount of surface acidic oxygen functional groups calculated from the titration values of sodium hydroxide and sodium carbonate corresponds to the amount of OH groups, and sodium carbonate and carbonic acid The difference in the amount of surface acidic oxygen calculated from the titration value with sodium hydrogen is equivalent to CO C = amount of base, and the amount of surface acidic oxygen functional group calculated from the titration value of sodium hydrogen carbonate is equivalent to the amount of COOH. Equivalent to.

The activated carbon fiber of the present invention is suitable for removing organic chlorinated compounds such as trihalomethane (for example, chloroform), trichloroethylene, and methylene dichloride. It is particularly useful for removing trihalomethanes. In other words, the present invention also includes a method for removing an organic chlorine-based compound using the activated carbon fiber of the present invention. The activated carbon fiber of the present invention can be used as a substitute for activated carbon in water purification equipment and water purification equipment that have been conventionally used. In particular, it is advantageous in that the organic chlorine compound can be effectively adsorbed and removed while passing water. For example, by passing water to be treated through a tubular body filled with activated carbon fibers, an organic chlorine-based compound in the water to be treated can be removed. In this case, the flow rate of water, the filling amount of activated carbon fibers, and the like may be in accordance with the conditions of the conventional technology.

2. Manufacturing method of activated carbon fiber

The method for producing the activated carbon fiber of the present invention is not limited. For example, it can be produced by the following production steps.

First, an organometallic compound and an activated carbon precursor are mixed in a solvent to obtain an activated carbon precursor mixture.

The activated carbon precursor is not particularly limited as long as it can easily become activated carbon and can be mixed with the above-mentioned organometallic compound and a solvent, but the theoretical carbonization yield during carbonization is good. Therefore, it is preferable to use the pitch.

Examples of the organometallic compound include an yttrium compound, a titanium compound, a zirconium compound, a vanadium compound, an iron compound, and a magnesium compound. These can be used alone or in combination of two or more. Examples of the yttrium compound include trisacetyl acetonatodiacoyttrium, yttrium isopropoxide, and yttrium acetyl acetonate. Examples of iron compounds include trisacetylacetonatoiron, triscyclopentenyliron, and the like. Examples of the titanium compound include titanium oxacetyl acetate. Examples of the zirconium compound include zirconium acetyl acetonate and the like. Examples of the magnesium compound include magnesium acetylacetonate. In particular, at least one of a yttrium compound, an iron compound and a magnesium compound is preferable in that the effect of controlling pores formed in the activated carbon is high.

The solvent is not particularly limited as long as it can dissolve both the organometallic compound and the activated carbon precursor. The solvent can be appropriately selected according to the type of the organometallic compound and the activated carbon precursor to be used. When mixing the above-mentioned organometallic compound and the activated carbon precursor using the above-mentioned solvent, a method of adding and mixing the activated carbon precursor in a solvent in which the organometallic compound is dissolved in advance, and A method in which a solvent in which an organometallic compound is dissolved is added and mixed may be employed. In such a mixing operation, operations such as stirring and heating may be appropriately added to achieve uniform mixing.

When preparing the above-mentioned mixture containing an organometallic compound, an activated carbon precursor and a solvent, the content of the metal component is usually from 0.01 to 5% by weight of the activated carbon precursor mixture, preferably from 0.1 to 5%. The mixing ratio of the organometallic compound and the activated carbon precursor is set to 2% by weight. Here, the content of the metal component is not the content as the organometallic compound but the amount in terms of the metal element.

When the above ratio is less than 0.01% by weight, the above-mentioned porous structure may not be easily formed in the obtained activated carbon, and as a result, the activated carbon may contain both a low molecular weight compound and a high molecular weight compound. In some cases, it may be difficult to achieve the required adsorption removal performance. On the other hand, when the content exceeds 5% by weight, the metal is easily condensed in the obtained activated carbon, so that the porous structure as described above is difficult to be formed. As a result, the activated carbon is a low molecular weight compound and a high molecular weight compound. In both cases, it may be difficult to exhibit the required adsorption and removal performance. Furthermore, the spinnability of the above mixture may be impaired. Incidentally, as the proportion of the organometallic compound increases, the average pore diameter generally increases.

Next, the obtained activated carbon precursor mixture is fiberized by a melt spinning method, subjected to carbonization treatment and Z or infusibilization treatment, and then further activated. At this time, it is preferable to remove the solvent from the activated carbon precursor mixture in advance.

The carbonization method, the infusibilization method, and the activation method of the activated carbon precursor mixture are not particularly limited. For example, it can be carried out in the following manner.

In the carbonization treatment, the activated carbon precursor mixture is heated to about 800 to 1200 ° C at a heating rate of about 5 to 10 minutes under an atmosphere of an inert gas such as nitrogen, and the maximum temperature at that time. Is maintained for up to 10 minutes.

The infusibilization treatment is performed in an inert gas atmosphere or an oxygen-containing gas atmosphere. The temperature of the precursor mixture is raised from a temperature lower than its melting point to 400 at a rate of about 0.1 to 5 Z minutes. It can be carried out by heating to about C.

Further, the activation treatment was performed by carbonization treatment and Z or infusibilization treatment in a gas atmosphere in which water vapor, carbon dioxide, oxygen and a mixed gas thereof and these gases were diluted with an inert gas such as nitrogen. It can be carried out by heating the activated carbon precursor mixture to about 800 to: L200 ° C and keeping it for about 5 to 120 minutes.

After the activation treatment, the activated carbon of the present invention having a total acidic functional group content of 0.2 mmol or less is cooled to 300 ° C. or less in an oxygen-free atmosphere (for example, in a nitrogen atmosphere). The production of fibers is possible.

3. Selection method of activated carbon fiber for removing organic chlorine compounds

In the present invention, in order to more reliably obtain activated carbon fibers suitable for removing organochlorine-based compounds, fine carbon particles obtained by as-analysis from the argon adsorption isotherm at the liquid argon temperature of the activated carbon fibers thus obtained are used. In the pore distribution,

(1) a specific surface area of micropores 7 0 0 m ² Z g or more,

(2) the specific surface area of the mesopores is 3 O n ^ Zg or more,

(3) It is desirable to have a step of selecting activated carbon fibers in which the pore volume of the mesopores is 10% or more and 70% or less of the total pore volume. The pore distribution can be obtained from the argon adsorption isotherm at the liquid argon temperature by the H-analysis in the same manner as described above. The present invention also includes a method for selecting activated carbon fibers for removing an organic chlorine-based compound. In other words, this is a method for selecting activated carbon fibers for removing organic chlorine-based compounds.In the pore distribution obtained by the as analysis from the argon adsorption isotherm of the activated carbon fibers at the liquid argon temperature,

(1) a specific surface area of micropores 7 0 0 m ² Zg above,

(2) the specific surface area of the mesopores is 30 m ² Zg or more,

(3) Another method is to select activated carbon fibers having a mesopore pore volume of 10% to 70% of the total pore volume as activated carbon fibers for removing organic chlorine-based compounds. Included in the present invention. This selection method can be applied to all activated carbon fibers, including activated carbon fibers produced by a method other than the above-mentioned production method. The above (1) ~

Activated carbon fiber that satisfies all the conditions of (3) is excellent for removing organic chlorine-based compounds. Demonstrated effects.

Since the activated carbon fiber of the present invention has a specific porous structure, large-diameter pores suitable for adsorbing organic chlorine-based compounds through water and small-diameter pores having a large total adsorption capacity for organic chlorine compounds are provided. It has both pores. For this reason, the activated carbon fiber of the present invention can exhibit good adsorption and removal performance in adsorbing organic chloride compounds through water. For example, when the activated carbon fiber of the present invention is used for purifying tap water or the like, organochlorine-based compounds such as trihalomethane, trichloroethylene, and methylene dichloride which may be carcinogenic contained in tap water are effectively removed. It can be removed by adsorption.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a graph showing the results of a cross-hole holm breakthrough test in Test Example 1.

FIG. 2 is a graph showing the results of the trichlorethylene breakthrough test in Test Example 1.

FIG. 3 is a graph showing the results of a methylene dichloride water breakthrough test in Test Example 1.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, examples and comparative examples will be shown, and features of the present invention will be described more clearly. However, the present invention is not limited to these examples.

Example 1

110 g of the coal tar from which water and quinoline insolubles were removed was heated to 80 under a nitrogen atmosphere, and trisacetylacetonatodiacoyttrium (Y (C Hs COCHCOC Hs) 2 ₂₀ ) 4.0 g of quinoline in which 4.0 g was dissolved was stirred for 5 hours while gradually adding dropwise thereto.

Next, this was distilled under reduced pressure, and reacted at 330 for 3 hours while blowing air at a rate of 5 LZ, to obtain a yttrium-containing coulter bitch, which was an active carbon precursor mixture.

The activated carbon precursor mixture thus obtained is charged into a spinner having a nozzle diameter of 0.3 mm, and is spun at a winding speed of 15 OmZ seconds while being heated to the pitch melting temperature. Thus, a pitch fiber was obtained. The obtained pitch fiber was heated from room temperature to 375 ° C at a temperature rising rate of 2 ° CZ in an air atmosphere, and kept at that temperature for 15 minutes to perform infusibility treatment. After that, the infusibilized pitch fiber is subjected to an activation treatment in a furnace at 850 for 30 minutes in a nitrogen gas atmosphere containing water vapor, and then rejected to 300 or less in a nitrogen atmosphere. Then, activated carbon fibers having the physical properties shown in Tables 1 and 2 were obtained.

table 1

Table 2

Example 2

The pitch fiber subjected to the infusibilizing treatment described in Example 1 was subjected to 875 under a nitrogen gas atmosphere containing water vapor. After activation treatment in the furnace of C for 30 minutes, under nitrogen atmosphere At 300 ° C. or lower to obtain an activated carbon fiber having the physical properties shown in Tables 1 and 2.

Comparative Example 1

A commercially available coal tar pitch (manufactured by Osaka Gas Chemical Co., Ltd.) was subjected to the same spinning and infusibilizing treatments as in Example 1, and the resulting infusibilized fiber was heated to 850 ° C in a nitrogen gas atmosphere containing steam. After an activation treatment in a furnace for 30 minutes, the mixture was naturally cooled in an air atmosphere to obtain activated carbon fibers having the physical properties shown in Tables 1 and 2. Test example 1

The activated carbon fibers of Examples 1 and 2 and Comparative Example 1 were subjected to the following test for water passage through a black mouth, trichlorethylene and water, and methylene dichloride. The results are shown in FIGS. 1, 2 and 3.

(1) Black mouth Holm water breakthrough test

Each activated carbon fiber was packed into a glass column so that the packing density was 0.15 g / cc, and water at 20 ° C with a chromate form concentration of 50 ^ gZ1 was superimposed at a superficial velocity of 1000 hr1. Water passed. Timely concentration analysis was performed until the column outlet concentration exceeded 20% of the raw water concentration. The activated carbon fiber of the present invention exhibited better performance than the activated carbon fiber of Comparative Example 1.

(2) Trichloroethylene water breakthrough test

Each activated carbon fiber was packed in a glass column so as to have a packing density of 0.15 gZcc, and water at 20 ° C with a trichlorethylene concentration of 50 gZ1 was passed at a superficial velocity of 100 Ohr- ¹ . The concentration was analyzed in a timely manner until the column outlet concentration exceeded 20% of the raw water concentration. The activated carbon fiber of the present invention exhibited better performance than the activated carbon fiber of Comparative Example 1.

(3) Methylene dichloride water breakthrough test

Each activated carbon fiber was packed into a glass column so that the packing density became 0.15 gXcc, and water at 20 ° C with methylene dichloride concentration of 50 j gZ1 was passed at a superficial velocity of 1000 hr]. . The concentration was analyzed at appropriate times until the column outlet concentration exceeded 20% of the raw water concentration. The activated carbon fiber of the present invention exhibited better performance than the activated carbon fiber of Comparative Example 1.

Claims

Scope of Claim 1 Activated carbon fiber used to adsorb and remove organochlorine compounds.The pore distribution obtained by s-analysis from the argon adsorption isotherm at the temperature of liquid argon is as follows: (1) Micropores (2) the specific surface area of the mesopores is 30 m2Zg or more, and (3) the pore volume of the mesopores is 10% or more and 70% or less of the total pore volume. Activated carbon fiber for removing organic chlorine compounds. 2. The activated carbon fiber for removing an organochlorine compound according to claim 1, wherein the total amount of acidic functional groups is 0.2 mmo1 or less. (3) A method for producing an activated carbon fiber for removing an organic chlorine-based compound, comprising: (a) a step of obtaining an activated carbon fiber by melt-spinning, infusibilizing, and activating the activated carbon precursor; In the pore distribution obtained by s analysis from the argon adsorption isotherm at the liquid argon temperature of the activated carbon fiber obtained, (1) the specific surface area of the micropore is 700 m2Zg or more, and (2) the specific surface area of the mesopore. (3) a process for selecting activated carbon fibers having a mesopore volume of 10% or more and 70% or less of the total pore volume. 4 This is a method for selecting activated carbon fibers for removing organic chlorine compounds.The pore distribution obtained by as analysis from the argon adsorption isotherm at the liquid argon temperature of the activated carbon fibers is as follows: (1) Specific surface area of micropores (2) The specific surface area of the mesopores is 3 On ^ Zg or more, and (3) The pore volume of the mesopores is 10% or more of the total pore volume の 0% or less. A method of selecting activated carbon fiber as the activated carbon fiber for removing organic chlorine-based compounds. 5 A method of adsorbing and removing an organic chlorine compound using activated carbon fiber, wherein the activated carbon fiber has a pore distribution determined by as analysis from an argon adsorption isotherm at a liquid argon temperature.

(1) The specific surface area of the micropore is 700 m ² Zg or more,

(2) the specific surface area of the mesopores is 30 m ² Zg or more,

6. The removal method according to claim 5, wherein the organic chlorine-based compound is at least one of trichloromethane, trichloroethylene, and methylene dichloride.