JPS60225639A - Activated carbon-inorganic sintered body molded adsorbent - Google Patents

Abstract

PURPOSE:To obtain an activated carbon-inorg. sintered body molded adsorbent having effect even to the removal of a polar inorg. substance or a lower polar org. substance, which can not be adsorbed and removed only by activated carbon, by mixing an activated carbon powder and a proper inorg. substance while molding the resulting mixture before baking. CONSTITUTION:An inorg. powder sinterable at 1,200 deg.C or less selected from clay, a glass powder, amorphous silica, a silica-alumina powder, white earth, a metal powder or metal oxide is added to an activated carbon powder and, if necessary, a water-soluble adhesive such as dextrin or methyl cellulose or an emulsion of a vinyl resin and water is added or mixed with said activated carbon powder while the resulting mixture is molded into an arbitrary shape, dried and sintered at 1,200 deg.C or less, pref., 1,100 deg.C or less under an inert atmosphere.

Description

[Detailed description of the invention] In the present invention, activated carbon powder is mixed with a suitable inorganic substance.

After molding this into any shape and drying it,
The present invention relates to an activated carbon-inorganic sintered adsorbent molded product obtained by sintering an inorganic material at a temperature of 0° C. or lower.

Activated carbon is a typical carbon-based adsorbent and is widely used for the adsorption and removal of five harmful gases and the removal of organic substances dissolved in water. Activated carbon has an essentially non-polar surface and is therefore effective in removing non-polar substances, ie so-called organic substances.

On the other hand, inorganic substances such as clay minerals silica and silica alumina have polar surfaces and are effective in removing polar substances, such as water or lower organic substances having polar groups at the terminals of their molecules. However, some of these minerals are
There are few substances with a wide specific surface area like activated carbon, and with the exception of silica gel, silica alumina, zeolite, and activated alumina, the specific surface area is small. In the sintered body obtained by sintering, the surface area of the sintered body as a whole does not become so small, although the inorganic substance itself is hardly expected to have a surface area because the inorganic substance is sintered.

This is a major feature of the present invention. However, since the inorganic substance added to form the structure of the molded product exhibits polarity opposite to the surface polarity of the activated carbon particles, it does not bond directly to the activated carbon particles but rather forms at the interface with one particle. As a result, it is thought that it exhibits a relatively high specific surface area value that cannot be obtained with a sintered body made of an inorganic substance alone.

If we look at this sintered adsorbent from the perspective of adsorption capacity.

Polar substances are adsorbed on the inorganic sintered part, and non-polar substances are adsorbed on the activated carbon part, each exhibiting a characteristic adsorption ability that cannot be obtained with a single adsorbent.

The activated carbon used in the present invention may be any fine dregs of commercially available uncharcoal or granular carbon. In addition, inorganic materials include clay minerals such as kaolin and montmorillonite minerals, glass powder, amorphous silica, silica-alumina powder, metal powders, metal oxides, and substances that can be sintered at temperatures below 1200℃. good. If montmorillonite clay is heated to 800° C. or higher, a sintered structure will not be formed, so care must be taken. When heat treatment is performed at 1200° C. or higher, the pore structure of activated carbon changes and the specific surface area decreases. Ideally, the temperature is preferably 1100° C. or lower, which does not cause any change in the pore structure of the activated carbon, and even in this case, it is better to avoid holding it for a long time. In other words, it is necessary to select the temperature and time at which the inorganic substance can be sintered, depending on each inorganic substance.

When clay minerals, silica, or silica alumina sol are used as the inorganic material, it is possible to make molded products due to their own adhesive properties, but when using other non-adhesive minerals, the shape of the molded product can be maintained. It is necessary to add adhesive for this purpose. Adhesives include water-soluble dextrin, cellulose adhesives such as methyl cellulose and carboxymethyl cellulose, vinyl adhesives such as polyvinyl alcohol, water-soluble adhesives such as vinyl acetate resin or its derivatives, and polyvinylidene chloride or its derivatives. An emulsion can be used. Most of these adhesives, except for polyvinylidene chloride, are thermally decomposed and gasified during the heat treatment process and do not remain inside the sintered body. Although some polyvinylidene chloride remains in the sintered body due to the heat treatment, this residue itself becomes a carbon-based porous material similar to activated carbon, so there is no problem.

The sintered body obtained in this way is not only effective in adsorbing and removing organic substances like activated carbon, but also effective in removing polar inorganic substances and lower polar organic substances that cannot be adsorbed and removed by activated carbon. .

Furthermore, since the sintered body itself exhibits a certain degree of tetraelectricity, by applying a constant voltage to both ends of this shaped sintered body,
The sintered body self-heats, the adsorbed molecules are desorbed, and regeneration is possible. When used for gas adsorption, almost 100% regeneration is possible, and even when used for adsorption of an aqueous solution, regeneration is possible at a considerable rate each time the voltage is controlled. However, if too much voltage is applied, the heat generation of the sintered body becomes excessive, and the activated carbon itself oxidizes and burns, leaving only inorganic matter.
It is preferable that it does not exceed C. Of course, it is also possible to regenerate by the method used for regenerating normal activated carbon.

Examples are shown below.

Example 1 Numata clay 40 parts by weight Activated carbon powder (Diahope, 100 Meso 60〃Bas) Mitsubishi Chemical Corporation■ Polyethylene glycol IO〃 50 parts by weight of water was added to the above mixture and kneaded with a kneader 8 three-stage roll. After that, 3 seals φ10 at room temperature with a moisture content of 30%.
It was molded into a cylindrical shape with a length of 0. After drying this at 100°C for one day, it was fired at 1100°C in an inert atmosphere. The specific surface area (S, A,) of the obtained sintered body was 900 i/g,
The amount of benzene adsorbed at 25°C at a relative pressure of 0.1 is 30
% by weight.

Example 2 Glass powder 30 parts by weight Activated carbon powder (Shirasagi Narita Pharmaceutical) 70〃125°F
Paraffin wax 20〃Carboxymethylcellulose 3〃 50M parts of water was added to the above mixture, and after kneading with a kneader 2 three-stage roll, 2.5 cranes φ1 were heated at 50°C with a water content of 30%.
It was extruded to a length of 00 mm. The obtained molded product is 】00°
After drying at C for 2 days, it was fired at 600°C in an inert atmosphere. S and A of the obtained sintered body are 950 m/g, 25
The amount of benzene adsorbed at °C relative pressure of 0.1 is 35% by weight.
Met.

Example 3 Silica sol (Catalyst Kasei Kogyo (41)) 100 parts by weight (silica content 30%) Activated carbon powder 60 parts by weight (Diasorb Mitsubishi Chemical Industries (Kikki)) Vinyl acetate resin emulsion 10〃 125°F Paraffin wax 10〃The above formulation Add 50 parts by weight of water and knead with three rolls of kneader 1.
At 100℃ with a molecular weight of 3 wt%, it is
It was molded with a length of n.

The obtained molded product was heat treated at 90°C for 2 days and then fired at 1000°C in an inert atmosphere. The S and A of the obtained sintered body were 1000 rrr/g, and the amount of benzene adsorbed at 25° C. and a relative pressure of 0°1 was 38%.

Example 4 Silica alumina powder (natural zeolite powder) 40 parts by weight Activated carbon powder 60〃 (Diahope Mitsubishi Chemical Industries @) Dextrin 10〃 Polyethylene glycol 10〃 50 parts by weight of water was added to the above mixture, and the same procedure as in Example 1 was carried out. The mixture was mixed, molded, and dried to obtain a sintered body.

The S and A of the obtained sintered body were 900 r//g, and the benzene adsorption amount was 35% by weight.

Example 5 Copper powder (100 mesoyu, pass) 30M parts Activated carbon powder 70〃 (Diahope, Mitsubishi Chemical Industries, Ltd. 0) Methyl cellulose 5〃 125°F paraffin wax 20〃The above mixture was prepared in the same manner as in Example 2 and sintered. I got a body. The S, A, of the obtained sintered body was 850 m/g, and the Hensen adsorption amount was 30% by weight.
, methylene blue adsorption capacity in water is 20% by weight
Met.

patent applicant Tombow Pencil Co., Ltd. Representative Kohei Ogawa

Claims (1)

[Claims] Activated carbon powder, clay, glass powder, and amorphous silica. Inorganic materials such as silica alumina powder, clay, metal powder, or metal oxides that can be sintered at temperatures below 1200℃ are added to give plasticity and adhesiveness to the molded product as necessary, and to improve workability. By adding a water-soluble adhesive such as dextrin, methylcellulose, carboxymethylcephalic acid, polyvinyl alcohol, or an emulsion of vinylidene chloride resin and their derivatives with water, mixing, molding, An activated carbon-inorganic sintered adsorbent molded product obtained by drying and firing and sintering in an inert atmosphere.