JP2015067514A - Active charcoal raw material composition, active charcoal, active carbon fiber and production methods thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an active charcoal raw material composition allowing acquisition of active charcoal in easy conditions, an active charcoal, and an active carbon fiber obtained by using the active charcoal composition and their production methods.SOLUTION: An active charcoal raw material composition is mixed with maleic acid-modified lignin and maleic anhydride. Active charcoal is obtained by mixing lignin with maleic anhydride to obtain the active charcoal raw material containing maleic acid-modified lignin and maleic anhydride, washing the active charcoal raw material composition, making the active charcoal raw material infusible and baking the infusible active charcoal raw material composition. An active carbon fiber is obtained by melting the active charcoal raw material with heating before the infusible treatment and spinning the molten active charcoal raw material composition.

Description

  TECHNICAL FIELD The present invention relates to an activated carbon raw material composition, activated carbon, activated carbon fiber, and methods for producing them, and more specifically, an activated carbon raw material composition obtained using lignin, activated carbon obtained using the activated carbon raw material composition, activated carbon fiber. And a manufacturing method thereof.

  Conventionally, activated carbon has been widely used as an adsorbent, a catalyst carrier, an electrode material, and the like. In particular, activated carbon fibers are used in various fields because they have a large surface area, excellent adsorptivity, and can be easily processed into woven fabrics.

  Wood, petroleum coke, coal coke, and the like are known as raw materials for producing such activated carbon (including activated carbon fiber). In recent years, lignin obtained as a by-product in pulp production and the like has been used. Is being considered.

  Specifically, for example, wood and polyethylene glycol (PEG) are mixed to produce pulp, and PEG-modified lignin is produced, and then the obtained PEG-modified lignin is heated to 145 to 172 ° C. After melting and spinning, an activated carbon fiber production method is known by immersing in a 1-6 M hydrochloric acid aqueous solution at 100 ° C. for 2-6 hours, followed by carbonization by heating (for example, (Refer nonpatent literature 1.).

Jian Lin, Satoshi Kubo, Tatsuhiko Yamada, Keiichi Koda, and Yasumitsu Uraki, CHEMICAL THERMOS TABILUZATION FOR THE PREPARATION OF CARBON ROM

  The technique of the said nonpatent literature 1 is generally recognized as a technique of obtaining activated carbon fiber using lignin.

  However, in the above-mentioned method, it is necessary to treat PEG-modified lignin under severe conditions of immersing in 1-6 M hydrochloric acid aqueous solution at 100 ° C. for 2 to 6 hours in the infusible treatment, and activated carbon fiber more easily. There is a need for a method that can provide

  An object of the present invention is to provide an activated carbon raw material composition capable of obtaining activated carbon, especially activated carbon fiber under easy conditions, activated carbon obtained using the activated carbon raw material composition, activated carbon fiber, and a method for producing them. There is.

  In order to achieve the above object, the activated carbon raw material composition of the present invention is characterized by containing maleic acid-modified lignin and maleic anhydride.

  Moreover, in the activated carbon raw material composition of the present invention, the content ratio of the maleic anhydride is 10 parts by mass or more and less than 100 parts by mass with respect to 100 parts by mass of the total amount of the maleic acid-modified lignin and the maleic anhydride. Is preferred.

  Moreover, the activated carbon of this invention is obtained using the said activated carbon raw material composition, It is characterized by the above-mentioned.

  The activated carbon of the present invention is preferably activated carbon fiber.

  In addition, the method for producing an activated carbon raw material composition of the present invention includes a step of mixing lignin and maleic anhydride to obtain a mixture, and a step of reacting the mixture.

  Moreover, in the manufacturing method of the activated carbon raw material composition of this invention, it is suitable that the said lignin is a herbaceous lignin.

  Moreover, in the manufacturing method of the activated carbon raw material composition of this invention, it is suitable that the said lignin is a powder form.

  Moreover, in the manufacturing method of the activated carbon raw material composition of this invention, it is suitable that the mixing ratio of the said maleic anhydride is 50 to 500 mass parts with respect to 100 mass parts of said lignins.

  Further, the method for producing activated carbon of the present invention includes a preparation step of mixing lignin and maleic anhydride to obtain an activated carbon raw material composition containing maleic acid-modified lignin and maleic anhydride, and washing the activated carbon raw material composition with water. And a non-melting step, and a firing step of firing the non-melted activated carbon raw material composition.

  Further, in the method for producing activated carbon of the present invention, before the non-melting step, a heating and melting step for heating and melting the activated carbon raw material composition, and a spinning step for spinning the molten activated carbon raw material composition; It is suitable to provide activated carbon fiber.

  Since the activated carbon raw material composition of the present invention contains maleic acid-modified lignin and maleic anhydride, it can be spun under easy conditions and infusible under easy conditions. Therefore, activated carbon, especially activated carbon fiber can be obtained more easily.

  Moreover, since the activated carbon raw material composition of this invention is used as a raw material, the activated carbon and activated carbon fiber of this invention can be obtained easily.

  Further, in the method for producing an activated carbon raw material composition of the present invention, lignin and maleic anhydride are mixed to obtain a mixture, and the mixture is reacted. Therefore, spinning is performed under easy conditions, and under conditions that are not easy. An activated carbon raw material composition that can be melted can be obtained. Therefore, activated carbon, especially activated carbon fiber can be obtained more easily.

  Moreover, since the activated carbon raw material composition containing maleic acid-modified lignin and maleic anhydride is washed with water to make it infusible, activated carbon, in particular, activated carbon fiber is easily obtained. be able to.

  The activated carbon raw material composition of the present invention contains maleic acid-modified lignin and maleic anhydride.

  The activated carbon raw material composition can be obtained according to the following production method.

  That is, in this method, for example, lignin and maleic anhydride are first mixed at a ratio (described later) in which maleic anhydride is excessive with respect to lignin to obtain a mixture.

  Lignin is, for example, a high molecular phenolic compound having a basic skeleton such as guaiacyl lignin (G type), syringyl lignin (S type), p-hydroxyphenyl lignin (H type), for example, by soda method. It is contained in the waste liquid (black liquor) discharged when manufacturing paper from pulp such as pulp manufacturing.

  Specific examples of lignin include wood-based plant-derived lignin and herbaceous plant-derived lignin.

  Examples of woody plant-derived lignin include coniferous lignin obtained from conifer pulp waste liquor, for example, hardwood lignin obtained from hardwood pulp waste liquor. Such woody plant-derived lignin does not contain lignin having H-type basic skeleton, for example, conifer lignin has G-type basic skeleton, and hardwood lignin has G-type and S-type basic skeleton. Yes.

  Examples of the herbaceous plant-derived lignin include rice-based lignin obtained from a grass family plant. Such herbaceous plant-derived lignin has all of H-type, G-type and S-type as the basic skeleton.

  These lignins are not particularly limited, and can be obtained by known methods, and commercially available products can also be used.

  These lignins can be used alone or in combination of two or more.

  The lignin is preferably a herbaceous plant-derived lignin.

  Moreover, as a lignin, Preferably, a powdery lignin is mentioned.

  The average particle size of the powdered lignin is, for example, 1000 μm or less, preferably 250 μm or less.

  If the average particle size of the powdered lignin is not more than the above upper limit, the reaction efficiency between lignin and maleic anhydride can be improved, and maleic acid-modified lignin can be obtained with excellent efficiency.

  Maleic anhydride is not particularly limited, and can be produced by a known method, and a commercially available product can also be used.

  In the mixing of lignin and maleic anhydride, the mixing ratio is such that the equivalent ratio of maleic anhydride to hydroxyl groups of lignin (number of moles of maleic anhydride / number of moles of hydroxyl groups in lignin) exceeds 1, Preferably, it is 1.2 or more, usually 5 or less.

  Further, on a mass basis, maleic anhydride is, for example, 50 parts by mass or more, preferably 70 parts by mass or more, more preferably 90 parts by mass or more with respect to 100 parts by mass of lignin. It is 300 parts by mass or less, more preferably 150 parts by mass or less.

  In this method, lignin and maleic anhydride can also be mixed in the presence of a solvent, if necessary.

  The solvent is not particularly limited as long as it is inert to lignin, maleic anhydride and maleic acid-modified lignin. For example, aliphatic hydrocarbons such as n-hexane, n-heptane, and octane, for example, cyclohexane And alicyclic hydrocarbons such as methylcyclohexane, and aromatic hydrocarbons such as toluene, xylene, and ethylbenzene.

  These solvents can be used alone or in combination of two or more.

  The solvent is preferably aromatic hydrocarbons, more preferably toluene.

  The mixing ratio of the solvent is, for example, 5 parts by mass or more, preferably 20 parts by mass or more, more preferably 50 parts by mass or more, with respect to 100 parts by mass of the total amount of lignin and maleic anhydride. It is 500 parts by mass or less, preferably 300 parts by mass or less, and more preferably 150 parts by mass or less.

  Furthermore, in this method, a catalyst (esterification catalyst) can be blended as necessary.

  Examples of the catalyst include amines such as triethylamine, quaternary ammonium salts such as triethylbenzylammonium chloride, phosphines such as triphenylphosphine, and phosphonium salts such as tetraphenylphosphonium bromide. Preferably, amines are used, and triethylamine is more preferable.

  These catalysts can be used alone or in combination of two or more.

  The blending ratio of the catalyst is, for example, 0.01 parts by mass or more, preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more with respect to 100 parts by mass of the total amount of lignin and maleic anhydride. Yes, for example, 50 parts by mass or less, preferably 20 parts by mass or less, more preferably 5 parts by mass or less.

  Next, in this method, the mixture obtained as described above is reacted by heating under normal pressure (atmospheric pressure), for example, and lignin is modified with maleic anhydride.

  As heating conditions, the heating temperature is, for example, 55 ° C. or higher, preferably 70 ° C. or higher, and for example, 200 ° C. or lower, preferably 150 ° C. or lower.

  The heating time is, for example, 5 minutes or more, preferably 10 minutes or more, more preferably 1 hour or more, and for example, 5 hours or less, preferably 2 hours or less.

  For example, when the above catalyst is blended, the lignin can be modified with maleic anhydride by heating or standing at room temperature for 3 to 10 days without heating.

  The end of the denaturation reaction is determined by the following method.

That is, by suspending a part of the reaction solution in excess water, maleic acid-modified lignin is precipitated and collected by filtration, etc., and then the ¹ H-NMR spectrum is measured, and the peak derived from the raw material lignin The reaction is judged to be complete when the intensity ratio of the peak (near 6 ppm) due to the maleic acid skeleton with respect to the time changes disappears. The peak derived from lignin may be any peak as long as it is quantitative. For example, a peak around 1.8 ppm due to the terminal methyl group of the isoeugenol structure is used. Since this peak is derived from a terminal methyl group that does not contribute to the reaction and appears sharply, it is suitable for quantification.

  Moreover, when a solvent is mix | blended, a solvent can be removed by a well-known method as needed.

  Thus, a maleic acid-modified lignin is obtained, and an activated carbon raw material composition containing the maleic acid-modified lignin and maleic anhydride (excess) can be obtained.

  In the activated carbon raw material composition, the content ratio of maleic acid-modified lignin and maleic anhydride is, for example, 10 parts by mass or more, preferably 10 parts by mass or more of maleic anhydride with respect to 100 parts by mass of maleic acid-modified lignin and maleic anhydride. Is 20 parts by mass or more, more preferably 30 parts by mass or more, and for example, less than 100 parts by mass, preferably 70 parts by mass or less, more preferably 50 parts by mass or less.

  In the activated carbon raw material composition, if the content ratio of maleic acid-modified lignin and maleic anhydride is within the above numerical range, the activated carbon raw material composition can be easily melt-spun and easily infusible. It can also be made.

  In addition, the manufacturing method of an activated carbon raw material composition is not limited above, For example, maleic acid modification | denaturation lignin and maleic anhydride can be prepared separately, and they can also be mix | blended with the said content rate.

  And since such activated carbon raw material composition contains maleic acid modified lignin and maleic anhydride, it can be melt-spun under easy conditions, and can also be easily infusible. Therefore, activated carbon, especially activated carbon fiber can be obtained more easily.

  Subsequently, the manufacturing method of activated carbon using said activated carbon raw material composition is explained in full detail.

  In this method, first, lignin and maleic anhydride are mixed as described above to obtain an activated carbon raw material composition containing maleic acid-modified lignin and maleic anhydride (preparation step).

  Next, in this method, the obtained activated carbon raw material composition is washed with water and insolubilized (infusible step).

  The washing method is not particularly limited, and examples thereof include a method of dripping water into the activated carbon raw material composition and a method of immersing the activated carbon raw material composition in water.

  In addition, water temperature is 50 degrees C or less, for example, Preferably, it is 30 degrees C or less.

  When the activated carbon raw material composition is immersed in water, the immersion time is, for example, 5 minutes or more, preferably 10 minutes or more, and for example, 30 minutes or less, preferably 20 minutes or less. .

  As a result, the maleic acid-modified lignin is insolubilized, and maleic anhydride contained in the activated carbon raw material composition reacts with water to become maleic acid, which is dissolved in water and removed.

  That is, maleic anhydride is removed by washing with water.

  The removal of maleic anhydride is confirmed by the following method.

  That is, after the activated carbon raw material composition is washed with water, it is further brought into contact with another water and the pH of the water (washing solution) is measured. When maleic anhydride remains in the activated carbon raw material composition, it becomes maleic acid and is eluted together with the washing liquid, so that the pH of the washing liquid is 3 or less, while maleic anhydride is removed. If so, there is no elution of maleic acid, and the pH of the washing solution is 5 or higher.

  As another confirmation method, after the activated carbon raw material composition is washed with water, it can be confirmed that maleic anhydride is removed by not melting even when heated to about 100 ° C.

  Next, in this method, the inactivated activated carbon raw material composition is fired (firing step).

  As the firing conditions, the firing temperature is, for example, 500 ° C. or higher, preferably 750 ° C. or higher, and for example, 1300 ° C. or lower, preferably 850 ° C. or lower.

  Moreover, baking time is 3 minutes or more, for example, Preferably, it is 4 minutes or more, for example, is 10 minutes or less, Preferably, it is 8 minutes or less.

  Thereby, an activated carbon raw material composition can be carbonized and activated carbon can be obtained.

  Moreover, the obtained activated carbon can also be activated by well-known methods, such as a gas activation method and a chemical activation method, as needed.

  In the gas activation method, for example, activated carbon is reacted with an activation gas such as water vapor or carbon dioxide at an appropriate time, for example, at 750 to 1100 ° C.

  In the chemical activation method, activated carbon is impregnated with chemicals such as zinc chloride and phosphoric acid, and chemicals with oxidizing properties such as potassium permanganate, and heated at 400 to 1000 ° C. for an appropriate time in an inert atmosphere.

  In addition, the timing in particular which activates activated carbon is not restrict | limited, You may activate after manufacturing activated carbon, and you may activate simultaneously with a baking process.

  And since the manufacturing method of such activated carbon wash | cleans the activated carbon raw material composition containing a maleic acid modified lignin and maleic anhydride and makes it inmelt, activated carbon can be obtained easily.

  Such activated carbon can be easily obtained because the activated carbon raw material composition is used as a raw material.

  Moreover, since the activated carbon raw material composition containing a maleic acid modified lignin and maleic anhydride is made to melt | dissolve in the manufacturing method of the activated carbon of this invention by water, activated carbon can be obtained easily.

  Moreover, for example, activated carbon fiber can also be obtained using said activated carbon raw material composition.

  In order to obtain the activated carbon fiber, for example, first, before the above-described infusifying step, the activated carbon raw material composition is heated and melted, for example, under normal pressure (atmospheric pressure) (heating melting step).

  As melting conditions, the melting temperature is, for example, 55 ° C. or more, preferably 70 ° C. or more, and for example, 150 ° C. or less, preferably 100 ° C. or less.

  If the activated carbon raw material composition is melted, the time required for melting does not affect the spinning process.

  Next, in this method, the melted activated carbon raw material composition is spun (spinning step).

  The method for spinning the melted activated carbon raw material composition is not particularly limited, and for example, a known spinning device such as an extrusion spinning device can be used.

  As the spinneret, a normal one can be used, and the hole diameter is, for example, 0.15 mm or more, preferably 0.17 mm or more, and, for example, 0.25 mm or less, preferably 0. 23 mm or less.

  Further, L / D (length / diameter) of the capillar portion is, for example, 1.5 or more, preferably 1.7 or more, and, for example, 2.5 or less, preferably 2.3 or less. is there.

  As the spinning conditions, the spinning temperature is, for example, 210 ° C. or higher, preferably 230 ° C. or higher, and for example, 300 ° C. or lower, preferably 280 ° C. or lower.

  The spinning speed is, for example, 200 m / min or more, preferably 250 m / min or more, and for example, 400 m / min or less, preferably 350 m / min or less.

  Thereafter, in this method, the spun activated carbon raw material composition is melted under the above-described conditions (non-melting process), and then fired under the above-described conditions (firing process).

  As a result, the spun activated carbon raw material composition can be carbonized, and activated carbon fibers can be obtained.

  Moreover, the obtained activated carbon fiber can also be activated by the above-mentioned well-known method as needed.

  Since the activated carbon raw material composition thus obtained and the method for producing such activated carbon can be easily melt-spun and infusible, activated carbon, especially activated carbon fiber can be obtained more easily. it can.

  Furthermore, the activated carbon raw material composition thus obtained and the method for producing such activated carbon can obtain activated carbon and activated carbon fibers having a large specific surface area.

  Therefore, it is suitably used in known activated carbon applications such as adsorbents, catalyst carriers, and electrode materials.

Next, although this invention is demonstrated based on an Example and a comparative example, this invention is not limited by the following Example. In the following description, “part” and “%” are based on mass unless otherwise specified. In addition, the numerical value of the Example shown below can be substituted to the corresponding numerical value (namely, upper limit value or lower limit value) described in embodiment.
<Preparation of activated carbon raw material composition and production of activated carbon>
Example 1
1 part by mass of powdered lignin (herbaceous lignin) having an average particle size of 200 μm and 1 part by mass of maleic anhydride were mixed and heated to 70 ° C. to melt maleic anhydride. Subsequently, it was made to react for 1 hour, stirring, and the activated carbon raw material composition (A) was obtained.

In addition, it was confirmed that the lignin was modified with maleic acid by the ¹ H-NMR method described above.

  In addition, the content ratio of maleic acid-modified lignin and maleic anhydride in the obtained activated carbon raw material composition (A) is such that maleic acid-modified lignin is 100 parts by mass of maleic acid-modified lignin and maleic anhydride. 70 parts by mass and 30 parts by mass of maleic anhydride.

  Subsequently, 10 mass parts of 25 degreeC water was dripped at 1 mass part of obtained activated carbon raw material compositions (A) in an air atmosphere, and it was made non-melting. In the insolubilization step, it was confirmed by the pH of the washing solution that maleic anhydride was removed.

  Then, even if it heated up the temperature of activated carbon raw material composition (A) to 100 degreeC, since the change was not seen, it confirmed that it was infusible.

And it baked for 5 minutes at 800 degreeC in nitrogen atmosphere, and obtained activated carbon (A).
(Example 2)
1 part by mass of powdered lignin (herbaceous lignin) with an average particle size of 200 μm, 1 part by mass of maleic anhydride and 2 parts by mass of toluene as a solvent were mixed, heated to 110 ° C., and refluxed with stirring. For 1 hour. After completion of the reaction, the solvent was removed using an evaporator to obtain an activated carbon raw material composition (B).

In the same manner as in Example 1, it was confirmed that lignin was modified with maleic acid.
Further, the content ratio of maleic acid-modified lignin and maleic anhydride in the obtained activated carbon raw material composition (B) is that maleic acid-modified lignin is 100 parts by mass of maleic acid-modified lignin and maleic anhydride. 65 parts by mass, and 35 parts by mass of maleic anhydride.

  Subsequently, after removing the solvent using an evaporator, 10 parts by mass of water at 25 ° C. was dropped into 1 part by mass of the obtained activated carbon raw material composition (B) in an air atmosphere to make it unmelted. In the insolubilization step, it was confirmed by the pH of the washing solution that maleic anhydride was removed.

  Then, even if it heated up the temperature of activated carbon raw material composition (B) to 100 degreeC, since the change was not seen, it confirmed that it was infusible.

And it baked for 5 minutes at 800 degreeC in nitrogen atmosphere, and obtained activated carbon (B).
(Example 3)
1 part by weight of powdered lignin (herbaceous lignin) having an average particle size of 200 μm, 1 part by weight of maleic anhydride, 0.02 part by weight of triethylamine, and 2 parts by weight of toluene as a solvent are mixed for 10 days at room temperature. I left it alone. Then, it confirmed that the product was melt | dissolving in toluene, the solvent was removed using the evaporator, and the activated carbon raw material composition (C) was obtained.

  In the same manner as in Example 1, it was confirmed that lignin was modified with maleic acid.

  Moreover, the content ratio of maleic acid-modified lignin and maleic anhydride in the obtained activated carbon raw material composition (C) is such that maleic acid-modified lignin is 100 parts by mass of maleic acid-modified lignin and maleic anhydride. 60 parts by mass, and 40 parts by mass of maleic anhydride.

  Next, after removing the solvent using an evaporator, 10 parts by mass of water at 25 ° C. was dropped into 1 part by mass of the obtained activated carbon raw material composition (C) in an air atmosphere to make it infusible. In the insolubilization step, it was confirmed by the pH of the washing solution that maleic anhydride was removed.

  Then, even if it heated up the temperature of activated carbon raw material composition (C) to 100 degreeC, since the change was not seen, it confirmed that it was infusible.

And it baked for 5 minutes at 800 degreeC in nitrogen atmosphere, and obtained activated carbon (C).
<Manufacture of activated carbon fiber>
Example 4
The activated carbon raw material composition (A) obtained in Example 1 was melted at 100 ° C., and using an extrusion spinning device (L / D: 2, pore size: 0.2 mm), spinning speed of 300 m / min and spinning temperature. Spinning at 250 ° C.

  10 mass parts of 25 degreeC water was dripped at the said melted and spun activated carbon raw material composition (A) in air atmosphere, and it was made non-melting. In the insolubilization step, it was confirmed by the pH of the washing solution that maleic anhydride was removed.

  Then, even if it heated up the temperature of activated carbon raw material composition (A) to 100 degreeC, since the change was not seen, it confirmed that it was infusible.

  And it baked for 5 minutes at 800 degreeC in nitrogen atmosphere, and the activated carbon fiber (A) was obtained.

Claims (10)

  An activated carbon raw material composition comprising maleic acid-modified lignin and maleic anhydride. With respect to 100 parts by mass of the total amount of the maleic acid-modified lignin and the maleic anhydride,
The activated carbon raw material composition according to claim 1, wherein a content ratio of the maleic anhydride is 10 parts by mass or more and less than 100 parts by mass.   Activated carbon obtained by using the activated carbon raw material composition according to claim 1 or 2.   The activated carbon according to claim 3, which is an activated carbon fiber. Mixing lignin and maleic anhydride to obtain a mixture;
And a step of reacting the mixture. A method for producing an activated carbon raw material composition.   The said lignin is a manufacturing method of the activated carbon raw material composition of Claim 5 which is a herbaceous lignin.   The said lignin is a manufacturing method of the activated carbon raw material composition of Claim 5 or 6 which is a powder form.   The mixing ratio of the said maleic anhydride is a manufacturing method of the activated carbon raw material composition as described in any one of Claims 5-7 which is 50 to 500 mass parts with respect to 100 mass parts of said lignins. A preparation step of mixing lignin and maleic anhydride to obtain an activated carbon raw material composition containing maleic acid-modified lignin and maleic anhydride;
A non-melting step of washing the activated carbon raw material composition with water and making it non-melting;
And a firing step of firing the infusible activated carbon raw material composition. Before the non-melting step,
A heating and melting step of heating and melting the activated carbon raw material composition;
A spinning step of spinning the melted activated carbon raw material composition,
The method for producing activated carbon according to claim 9, wherein activated carbon fibers are obtained.