JPS62289618A - Production of fibrous active carbon - Google Patents

Abstract

PURPOSE:To reduce occurrence of dusting and obtain fibrous active carbon with good processability and yield, by forming carbon fibers into a structure, e.g. mat, etc., before activation in successively infusibilizing, carbonizing and activating pitch based fibers to give the aimed fibrous active carbon. CONSTITUTION:A pitch based material is spun to give fibers, which are infusibilized at 250-440 deg.C in, e.g. an oxygen-containing atmosphere, and then treated at 500-3,000 deg.C in, e.g. an inert gas atmosphere to carry out carbonization. The resultant carbon fiber filaments are then formed into an optional fibrous structure, e.g. felt, mat, woven fabric, string, etc., and then activated at 820 deg.C in, e.g. steam to afford the aimed fibrous active carbon.

Description

[Detailed description of the invention] Detailed description of the invention Industrial applications The present invention relates to a method for producing $iI fibrous activated carbon.

Conventional technology and its problems Conventionally, in the production of fibrous activated carbon using pitch-based materials as raw materials, the refined raw material pitch is heat treated, the pitch fibers obtained by spinning are made infusible, carbonized and activated, and then This is done by making it into a felt or mat shape. However, in such conventional techniques, since the porous and low-strength activated carbon filament 1 after trial use is used as a fiber structure, breakage is severe and the yield is low. To improve yield, it is necessary to use glass fiber or carbon fiber as reinforcement material. Furthermore, there is a problem of deterioration of the working environment due to the generation of large amounts of dust, and furthermore, it is virtually impossible to obtain fibrous structures in complex shapes such as woven fabrics, knitted fabrics, and strings.

Means for Solving the Problems As a result of extensive research in view of the current state of the technology as described above, the inventor of the present invention has found that, prior to activation, when carbon fiber filaments are made into a fiber structure and then activated, It has been found that the problems of the prior art can be reduced to 11". That is,
The present invention provides fibrous activated carbon made from pitch-based materials.
The present invention relates to a method for producing fibrous activated carbon, which is characterized in that the pitch fibers obtained by spinning a pitch-based material are infusible and carbonized to form a fiber structure, and then activated.

The pitch-based material for spinning used in the present invention is not particularly limited, but is preferably obtained by subjecting a pitch-like substance to thermal polycondensation under inert gas flow. The pitch-like substance may be any of petroleum-based pitch, coal-based pitch, and pyrolysis residue pitch from a pyrolytic compound.

Infusibility and carbonization of pitch fibers obtained by spinning pitch-based materials may also be carried out according to conventional methods. For example, after infusibility treatment at a temperature of about 250 to 440°C in an oxygen-containing atmosphere, the pitch fibers can be infusible and carbonized in an inert gas atmosphere. 500~3000℃
You just need to heat it up.

Next, the carbon fiber filament obtained above is made into any shape such as felt, mat, woven fabric, knitted fabric, string, etc. I
After processing into an Ifi structure, it is activated. The activation treatment is carried out in the presence of water vapor, carbon dioxide, air, etc. according to a conventional method.

Effect of the invention According to the present invention, the following remarkable effects can be obtained.

(1) Carbon fiber filaments have excellent strength and good workability, so it is possible to make mum structures with highly processed and complex forms such as woven fabrics, knitted fabrics, and strings, and even complex forms. fibrous activated carbon can be obtained. For example, it is now possible to manufacture cylindrical activated carbon structures for filter media, which were impossible to manufacture using conventional methods! The applications of IN-type activated carbon will expand significantly.

(2) Glass! 1iii. Processing can be performed with good yield without using reinforcing materials such as carbon fiber M. For example, when matte activated carbon is produced by needle punching in the conventional method, the yield is about 25%, whereas in the present invention, the yield reaches about 40% or more.

(3) The work environment is improved because the generation of dust is reduced.

EXAMPLES The features of the present invention will be further clarified through examples below.

Example 1 Coal tar pitch (softening point 280'C) purified and heat treated according to conventional methods was melt-spun at 340'C,
Deposit felt pitch l! A fiber was produced, heated to 350'C in air at a rate of 3°C/min, and kept at the same temperature for 1 hour to make it infusible.

The obtained infusible felt-like am was heated at 1200°C in nitrogen gas.
After carbonizing for 5 minutes, it was processed by needle punching to obtain felt-like carbon 11#ilI with a thickness of 10+++ m.

Next, mN of the felt-like carbon was heated in steam at 820°C for 3
By performing the activation treatment for 0 minutes, felt activated carbon having a thickness of 7 mm was obtained. Its specific surface area was 1000 m2/q.

In this example, infusible fers 1 to 1! When the weight of M is 100, the weight after carbonization is 90°, the weight after needle punching is 85, and the weight after punching is 43. On the other hand, when using the conventional method, the N value after carbonization and activation was 50, and the weight after felting was 25. From this, according to the present invention, the yield is 1.72 compared to the conventional method.
It is clear that the number has doubled.

Example 2 The same coal tar pitch as in Example 1 was melt-spun under the same conditions, and pitch 1IIfi of length 11 and miscellaneous shape was wound onto a bobbin.

A 10% aqueous nitric acid solution was sprayed on the resulting pitch, and the mixture was heated in air from 42° C. to 350° C. over 30 minutes to make it infusible.

The obtained infusible felt m fibers were carbonized in nitrogen gas at 1200°C for 5 minutes, and then combined according to a conventional method to obtain a length of 1500 denier carbon 131N,
0111m, thickness 0.45III11, and then activated in steam at 820°C for 25 minutes to obtain a width of 49m.
a+, thickness 0.4211m (7) $1Th condition fHJ2
I did it. Its specific surface area was 1020 m2/g.

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Claims (1)

[Claims] (1) A method for producing fibrous activated carbon using a pitch-based material as a raw material, characterized in that the pitch fibers obtained by spinning the pitch-based material are infusible, carbonized, made into a fibrous structure, and then activated. A method for producing fibrous activated carbon.