JPH03187910A - Production of powdery or granular activated carbon - Google Patents

Abstract

PURPOSE:To obtain powdery or granular activated carbon having a large specific surface in high yield by polymerizing a vinyl monomer containing particles comprising cured novolak resin, etc., carbonizing and activating. CONSTITUTION:Powdery or granular cured novolak resin or resol type granular phenol resin is prepared. The resin is incorporated with a vinyl monomer (e.g. acrylic ester monomer, methacrylic ester monomer or vinyl aromatic monomer). Then the vinyl monomer is subjected to graft polymerization in the resin, carbonized and activated.

Description

[Detailed description of the invention] [Objective of the invention] Relating to a manufacturing method.

<Prior Art> Conventionally, powdered activated carbon uses rubber charcoal or powdered coal as a raw material carbide, and granular activated carbon is produced by granulating petroleum pitch or powdered coal. These have an activated carbon yield of 50-30%
However, only those with a low specific surface area of 800 to 1000 r&/g can be obtained.

On the other hand, those made from phenolic resin have a rating of 1,000 to 15
Activated carbon with a specific surface area of 00 i/g is obtained, but the yield is 25
It was expensive because it was as low as ~10%.

<Problems to be Solved by the Invention> The present invention has been made as a result of intensive studies focusing on the above-mentioned problems.

That is, an object of the present invention is to provide a method for manufacturing powdered or granular activated carbon having a large specific surface area at low cost.

[Structure of the invention]

Means for Solving the Problems The present invention is characterized in that a powdery or granular cured novolac resin contains a vinyl monomer, and that the vinyl monomer is polymerized in the resin and then carbonized. A method for producing powdery or granular activated carbon, and a powdery or granular activated carbon characterized by containing a vinyl monomer in a resol type granular phenol resin, polymerizing the vinyl monomer in the resin, and then carbonizing the activated carbon. This is a method for producing granular activated carbon.

The present invention will be explained in detail below.

In activated carbonizing powdered or granular phenolic resin, the present inventors made activated carbon with a high yield and a large specific surface area by uniformly diffusing the activation gas into the resin and increasing its speed. As a means of achieving this, it is possible to incorporate a vinyl monomer into a powdered or granular cured novolak resin or a resol type granular phenol resin, polymerize the vinyl monomer in the resin, and then carbonize it. We have found that this method is very effective for this purpose.

According to the present invention, when the vinyl monomer is polymerized in the resin, the resin particles swell. When this swollen powdered or granular cured novolac resin or swollen resol type granular phenolic resin is carbonized, the vinyl polymer in the particles has a lower fixed carbon percentage than the phenolic resin, so it becomes a carbonized material with developed micropores. Become. By subjecting this to an activation reaction, powdery or granular activated carbon with a high yield and a large specific surface area can be obtained.

The phenolic resin used in the present invention can be obtained by, for example, coarsely pulverizing a novolak resin, immersing it in a mixed aqueous solution of 18% by weight hydrochloric acid and 10% by weight formaldehyde, raising the temperature without stirring, and curing the resin. Novolac resin, hexamine kneaded into novolac resin and pushed out molding.
Hardened granular hardened novolac type resin, Tokuko Sho 6F-5
Examples include, but are not limited to, resol type spherical resins shown in Japanese Patent Publication No. 9324 and Japanese Patent Publication No. 62-3855.

Vinyl monomers include, for example, acrylic acid ester monomers such as acrylic acid, methacrylic acid, methyl acrylate, and ethyl acrylate, and methacrylic ester monomers such as methyl methacrylate, butyl methacrylate, and propyl methacrylate. vinyl aromatic monomers such as styrene, ethylstyrene, and vinyl ester monomers such as vinyl acetate, as well as vinyl halide monomers such as vinyl chloride and vinylidene chloride, and vinylidene halide monomers. mer, maleic anhydride, acrylamide, methacrylamide, acrylonitrile, and methacrylonitrile.

The method of incorporating the vinyl monomer into the cured novolac resin or resol type granular phenolic resin is not limited, but the vinyl monomer is dissolved or dispersed in water, a solvent, etc., and the cured novolac resin is immersed therein. The preferred method is to Furthermore, known methods can be used for polymerization.

The graft polymerization of the present invention is a generally known polymerization reaction, in which radicals that serve as reaction initiation points are generated on the surface or inside of resin particles by irradiating radiation such as electron beams and X-rays, ultraviolet rays, low-temperature plasma, etc. Examples include a method of producing and polymerizing, and a method of polymerizing by a chain transfer method in a solution system or emulsion system using a specific polymerization initiator. In addition,
In the method using a polymerization initiator, the combination of the monomer to be grafted and the polymerization initiator, the type of emulsifier,
It is important to select conditions such as the temperature of the reaction system.

In order to activate carbonization of a powdery or granular cured phenol resin containing a vinyl compound obtained by such a method, the cured product is first heated at a temperature of 150 to 300°C for 30 to 15 minutes.
After heat treatment for 0 minutes, activation with an oxidizing gas such as water vapor, carbon dioxide, or air may be performed at a temperature of 700 to 900°C by a conventional method.

Powdered or granular cured phenolic resin products containing vinyl compounds will be eluted out of the particles or thermally decomposed during the initial heat treatment at 150 to 300°C! This erases the resin and generates fine pores, which widen the contact area of the activation gas during carbonization activation treatment, make the diffusion of the activation gas inside the resin uniform, and work effectively. Activated carbon with a specific surface area can be obtained.

<Examples> Examples of the present invention will be specifically described below. Note that parts and percentages in the examples are based on weight unless otherwise specified.

Example 1 100 g of a powdered resin obtained by pulverizing a novolak resin (softening point 110°C) was added and dispersed with stirring into a Mitsuro flask (equipped with a stirrer) containing 500 g of a mixed aqueous solution of 18% hydrochloric acid and 10% formaldehyde. let While stirring, the liquid temperature is raised from 30°C to 90°C over 4 hours, and 90°C is maintained for 4 hours. Next, the mixture was neutralized with aqueous ammonia, washed with water, filtered and dried to obtain a powdery cured novolak resin (A).

After immersing 10 g of this resin (A) in a mixed solution of methyl methacrylate/methanol = 1/1, gradient filtration was performed, and an electron beam of 20 Mrad was applied to the
The methyl methacrylate was polymerized in the resin by irradiation for minutes. Thereafter, washing with acetone and drying were performed to obtain a methyl methacrylate polymerized phenol resin.

The resin was placed in a quartz tube with an inner diameter of 70 mmφ, and after reaching 300°C at a heating rate of 5°C/min, a mixed gas of nitrogen and water vapor was introduced into the quartz tube, and the temperature was further increased to 850°C at the same heating rate.
The temperature was raised to °C and held at that temperature for 40 minutes. Thereafter, the mixture was cooled while introducing only nitrogen gas to obtain powdered activated carbon.

Example 2 In a 2Q Mitsuro flask, 95 g of methyl methacrylate from which the polymerization inhibitor had been removed with activated alumina, nitric acid dibasic
Cerium ammonium 4gt nonionic activator LT
1.9 g of -221 (NOF type) and 1756 g of purified water were added and mixed and stirred using a homogenizer to form an emulsified system. Resin (A) 2 prepared in Example 1 in this emulsion system
0 g was added with stirring, the emulsion system was kept at a temperature of 50°C for 3 hours while nitrogen gas was passed through it, and the reaction was stopped by pouring it into purified water. The cured novolac resin powder obtained by graft polymerization of methyl methacrylate obtained by this method was carbonized and activated in the same manner as in Example 1 to obtain powdered activated carbon.

Example 3 500 g of phenol and 646 g of 4.2% formalin were
Q Pour 23g of 25% ammonia water into a Mitsuro flask.
, 11% polyvinyl alcohol (completely saponified, average degree of polymerization 1700) was added and reacted at 60°C for 4 hours.

Further, 35 g of a 40% aqueous hexamethylenetetramine solution was added, the temperature was raised, and the mixture was reacted at 80°C for 3 hours to produce a resol type spherical phenol resin dispersion. After adding 200 g of concentrated hydrochloric acid to this system, it was treated at 90°C for 2 hours, filtered and dried to obtain a resol type granular phenolic resin (B).

This resin (B) Log was immersed in a mixed solution of methyl methacrylate/methanol = 1/1 for 10 minutes, and then subjected to gradient filtration, and 20 M r a at 35°C in a nitrogen atmosphere.
d was irradiated with the electron beam for 5 minutes to polymerize methyl methacrylate in the resin. This was washed with acetone to obtain a methyl methacrylate polymerized phenol resin.

The resin was carbonized and activated in the same manner as in Example 1 to obtain granular activated carbon.

Example 4 The phenolic resin used was the resin synthesized in Example 3 (E
) Granular activated carbon was obtained by the same operation as in Example 2 except that

Comparative Example As a comparison of Examples 1 to 4, the cured novolac resin (A) shown in Example 1 was placed in a quartz tube with an inner diameter of 70 mm, and a mixed gas of nitrogen and water vapor was introduced into the quartz tube at 5 degrees per minute.
The temperature was raised to 850° C. at a temperature increasing rate of 40° C. and held at this temperature for 40 minutes. Thereafter, the mixture was cooled while introducing only nitrogen gas to obtain powdered activated carbon.

Table 1 shows the results and yields of the specific surface areas of the activated carbons obtained in Examples 1 to 4 and Comparative Examples described above, which were measured using a flow type automatic specific surface area measurement device manufactured by MicroNolitics.

q- 0- Table-1 [Effects of the Invention] As described above, according to the present invention, it is possible to provide a manufacturing method that can obtain powdery or granular activated carbon with an extremely high yield and a large specific surface area.

As is clear from Table 1, the powdered or granular activated carbon obtained in each example had a lower
Yield: 2.23 to 2.53 times, specific surface area: 1.66 to 1
．． 76 times, resulting in a high yield and a significantly increased specific surface area.

11- 12-

Claims (4)

[Claims] (1) A method for producing powdery or granular activated carbon, which comprises adding a vinyl monomer to a powdery or granular cured novolac resin, polymerizing the vinyl monomer in the resin, and then carbonizing the resin. . (2) The method for producing powdery or granular activated carbon according to claim 1, wherein the polymerization of the vinyl monomer is graft polymerization. (3) A method for producing powdery or granular activated carbon, which comprises incorporating a vinyl monomer into a resol type granular phenolic resin, polymerizing the vinyl monomer in the resin, and then carbonizing the resin. (4) Claim 3 that the polymerization of the vinyl monomer is graft polymerization
The method for producing the powdered or granular activated carbon described above.