JPH03127607A - Activated carbon structure - Google Patents

Abstract

PURPOSE:To desorb the malodorous component in a heated activated carbon porous body and to improve adsorptivity by providing the porous body obtained by carbonating and activating a foamed plastic and a means for heating the porous body. CONSTITUTION:A rod-shaped activated carbon porous body 5 and a heating element 7 are alternately arranged in parallel in a heat-resistant insulating case 3 with a gap in between. The heating element 7 is connected to a power source 20 through an electric wire 11. Meanwhile, the porous body 5 is obtained by foaming a resol-type phenolic resin with a blowing agent such as paraffinic hydrocarbons and a curing agent such as sulfuric acid, calcining and carbonizing the foamed product in a nonoxidizing atmosphere, heating and activating the product in an oxidizing gas atmosphere. The porous body 5 having adsorbed the malodorous component in a fluid is heated by the energized heating element 7 to desorb the component. The adsorbate can be repeatedly desorbed.

Description

[Detailed description of the invention] Technical field of invention The present invention relates to a novel activated carbon structure.

TECHNICAL BACKGROUND OF THE INVENTION In recent years, due to concerns about health, awareness of the harmful effects of smoke emitted from cigarettes has increased, and there has been a strong demand for indoor air purification.

In order to meet such demands, various air purifiers are on the market, and recently, air conditioners with deodorizing performance have also begun to be commercially available.

By the way, activated carbon such as activated carbon fibers and granular activated carbon, and urethane foam impregnated with activated carbon have been known as the most effective adsorbents for the malodorous components contained in cigarette smoke. .

However, when such adsorbents are used in air conditioners,
Since extremely low pressure loss is required, the amount of use thereof is limited, and as a result, only low deodorizing performance can be obtained.

In addition, restrictions on the amount of air purifiers used will be eased, but in any case, as they absorb odor components,
Deterioration in adsorption performance was inevitable, and periodic replacement of the filter was required.

Purpose of the Invention The present invention aims to solve the problems of the prior art as described above, and provides an activated carbon structure that has excellent deodorizing performance and does not require replacement due to deterioration of deodorizing performance. is intended to provide.

Summary of the Invention The activated carbon structure according to the present invention is characterized by having an activated carbon porous body formed by carbonizing and activating a plastic foam, and a heating means for heating the activated carbon porous body.

According to the activated carbon structure according to the present invention, by heating the activated carbon porous body with a heating means to raise the temperature, it is possible to desorb the malodorous components adsorbed to the activated carbon porous body, so that the deteriorated deodorizing performance can be recovered. can.

Detailed Description of the Invention The activated carbon structure according to the present invention will be specifically described below.

The activated carbon porous body constituting the activated carbon structure according to the present invention is preferably obtained by carbonizing a phenolic resin foam and then activating it.

This phenolic resin foam is obtained by foaming and curing a phenol resin, and as such a phenol resin, a resol type phenol resin is preferably used.

A resol type phenolic resin can be obtained by reacting phenols and aldehydes in the presence of an alkali catalyst according to a known method.

Specifically, phenols include phenol, cresol, xylenol, resorcinol, and the like.

Specifically, formaldehyde, acetaldehyde, furfural, and the like are used as the aldehydes.

Specifically, the alkali catalyst is KOH.

N a OH-N H-N Ha OH, :c, tanolamine, ethylenediamine, and the like are used.

As the foaming agent for foaming the resol type phenolic resin, various conventionally known decomposition type foaming agents and evaporation type foaming agents can be used.

Among these, evaporative blowing agents are preferred, and specifically, paraffinic hydrocarbons, alcohols, ethers, and halogenated hydrocarbons are most preferably used.

As the halogenated hydrocarbon, specifically, chloroform, carbon tetrachloride, trichloromonofluoromethane, dichloromonofluoromethane, tetrachlorodifluoroethane, trichlorotrifluoromethane, dichlorotetrafluoroethane, dibromotrifluoroethane, etc. are used.

As paraffinic hydrocarbons, butane, pentane, hexane, cyclopenkune, cyclohexane, and mixtures thereof having a boiling point at room temperature or slightly higher than normal temperature are preferably used. The amount of blowing agent is χ=
JL, 1-20 is preferred.

A curing agent is used together with a foaming agent to foam and harden the resol type phenolic resin, and as such curing agents, various conventionally known curing agents are selected and used depending on the type of prepolymer. Specifically, sulfuric acid, hydrochloric acid, phosphoric acid, phenolsulfonic acid, benzenesulfonic acid, toluenesulfonic acid, metacresolsulfonic acid,
Resorcinol sulfonic acid, butyl sulfonic acid, propyl sulfonic acid, etc. are used.

Such curing agents are usually resol type phenolic resins 1
00 parts by weight, 3~BOff! Used in parts. Further, in the present invention, other parts such as a foam stabilizer and a filler may be used in combination as necessary.

obtained by mixing and stirring the above resol type phenolic resin, blowing agent, and curing agent all at once or sequentially,
When the creamy phenolic resin prepolymer composition is fed into a heat-insulated mold or onto a 2 m belt conveyor, the phenolic resin prepolymer composition is foamed and cured.

The obtained resin foam may be cut as necessary.

The molded rod of the phenolic resin foam thus obtained is carbonized by firing in a non-oxidizing or slightly oxidizing atmosphere, either directly or after being suppressed.

That is, under reduced pressure or in Ar gas, He gas, N2 gas, halogen gas, ammonia gas, hydrogen gas, -carbon oxide, etc., preferably at 500 to 1200°C, especially at 60°C.
Calcinate at a temperature of 0 to 900°C. In this way, the foam is carbonized and a porous carbon body is obtained.

Although there is no particular restriction on the rate of temperature increase during firing, it is preferable to increase the temperature gradually around 200 to 600°C, where the resin content M'/ generally starts to increase.

The carbon porous body thus obtained is further activated by an activation treatment in which it is heated at a temperature of 700 to 1000°C in an oxidizing gas atmosphere.

As the oxidizing gas, various conventionally known oxygen-containing gases used in the activation treatment of activated carbon are used, and a mixed gas of an oxidizing gas such as oxygen or water vapor and an inert gas is preferably used.

The mixing ratio of inert gas and oxidizing gas is determined depending on the processing temperature, but considering workability, the oxidizing gas should be 0.01 to 0.5 mol per mol of inert gas, Preferably, they are mixed in a proportion of 0.1 to 0.3 mole.

The activation treatment time as described above varies depending on the concentration of the oxidizing gas mentioned above, but considering workability, it is usually 1 minute to 1 minute.
Preferably, the period is within 24 hours.

The activated carbon porous material thus obtained has a bulk density of 0.
．． It is preferably in the range of 0.05 to 0.5 g/cxl.

By setting the density of the activated carbon porous body within such a range, the activation operation can be facilitated and a porous body having extremely excellent deodorizing performance can be obtained.

Furthermore, by setting the bulk density of the activated carbon porous body to 0.05 g/d or more, sufficient self-retention force and strength can be obtained to form a structure described below.

In addition, the specific surface area of the activated carbon porous material is usually 500rtf
/g or more, and an activated carbon porous material having a specific surface area within this range has an extremely excellent ability to adsorb bad odors and the like.

Note that the specific surface area in the present invention is determined by the BET method.
This value was determined from the isothermal adsorption curve.

Furthermore, the carbon content of the activated carbon porous material is preferably 8
5 to 95%, particularly preferably 88 to 92%. By setting the carbon content of the activated carbon porous body to the above value, an activated carbon porous body having extremely excellent deodorizing performance can be obtained.

The activated carbon porous material used in the present invention must have excellent adsorption performance and heat resistance, as well as appropriate self-retention power.

On the other hand, activated carbon impregnated with urethane foam, which has conventionally been widely used in air purifiers, has no conductivity and has a low heat resistance of about 80°C, so it cannot be heated by providing a heating means as in the present invention. , cannot be made playable.

In addition, since granular activated carbon and spherical activated carbon do not have a fixed shape, a housing for storing the activated carbon is required in order to provide a heating means near the activated carbon to provide a structure that can heat the activated carbon uniformly. However, if such a housing is provided, the IR structure becomes complicated, and if the housing is made of plastic, there is a problem with heat resistance, and if the housing is made of metal, the heat capacity of the housing is high, so it requires more heat during heating. However, due to its high thermal conductivity, there are problems such as adverse effects on other components. Furthermore, since activated carbon fibers also have poor self-retention properties, they have the same problems as granular activated carbon, as well as problems such as the fibers scattering, especially when heated. In the activated carbon structure according to the present invention, such an activated carbon porous body is arranged in a flow path of air containing malodorous components.

At this time, various shapes can be considered as the shape of the activated carbon porous body, such as a plate-like object, a rod-like object, or a
Examples include a plate-like material with holes as described in Japanese Patent No. 96161.

In the activated carbon structure according to the present invention, such an activated carbon porous body is disclosed in Japanese Patent Application No. Hei 1. As described in Japanese Patent No. 96157, a plurality of slits are arranged side by side at predetermined intervals (it may be one slit).

Such a slit structure is preferable because it has a small pressure loss and can take a shape suitable for Joule heating, which will be described later. Among the slit structures, a slit structure composed of a rod-like body of porous activated carbon is particularly preferable because of its low pressure loss.

The 111 carbon porous material that constitutes the slit (1)
Although the width, thickness, and length can be any desired, from the viewpoint of electrical resistance and adsorption performance, it is preferable that the shape be as dirty and thin as possible within the range that provides sufficient structural strength.

The activated carbon structure according to the present invention includes such an activated carbon porous body and heating means for the activated carbon porous body.

As the heating means used in the present invention, it is possible to use various known heating elements, for example, a nichrome wire is used as the metal material, a ceramic heater such as StC, an infrared heater, a graphite heater, etc. A carbon heater such as the above can be used.

It is made of a heat-resistant and conductive long hard material, and is connected to an external power source by an electric wire, a metal rod, etc. via other elements such as a plug, outlet, switch, etc., as necessary.

In such an activated carbon structure according to the present invention, when a voltage is applied to the heating element to heat the activated carbon porous body, the adsorbed substance adsorbed to the activated carbon porous body is desorbed. When the activated carbon concept according to the present invention is used as a deodorizing filter, when the adsorption performance decreases,
The heating element generates heat, and as a result, the activated carbon porous body is heated to desorb the adsorbed substance and restore the adsorption capacity.

Furthermore, the activated carbon structure according to the present invention can also be used as a heater; for example, when incorporated into an air conditioner, it can function as an air conditioner filter and a heater.

Next, one interesting aspect of the activated carbon structure according to the present invention will be explained in more detail with reference to the attached FIG. 1.

FIG. 1 is a schematic diagram showing a preferred embodiment of the activated carbon structure according to the present invention.

As shown in FIG. 1, an activated carbon structure 1 includes rod-shaped activated carbon porous bodies 5, 5, . . . arranged in a case 3 having heat resistance and insulation properties; 5.
Heating elements 7, 7 as heating means provided between...
It is equipped with... The rod-shaped activated carbon porous bodies 5, 5, . . . in the case 3 are arranged in parallel with intervals, thereby forming a slit structure.

When such an activated carbon structure 1 is used in an air purifier or the like, it is arranged in a flow path of air containing malodorous components, and the heating elements 7, 7... are connected by electric wires]1゜11. Power source 20 is connected. Further, at this time, the electric wire 11 may be provided with a timer or the like.

Next, to explain the operation of the activated carbon structure built into such an air purifier, the air that is circulated between the inside of the air purifier and the room by the fan of the air purifier (not shown) is Activated carbon (113) is placed in the flow path of the air flowing between the slits of the relic 1, and at this time, the malodorous components in the air are absorbed by the activated carbon porous rod-shaped body 5.5.
It is absorbed by...

After a predetermined period of time has elapsed, a voltage is applied to the heating elements 7, 7... by the action of a timer (not shown), and the activated carbon porous rods 5, 5, which have been adsorbed to a certain degree, are removed, and at the same time, the malodorous components are removed. It is attached and detached. This desorbed component is discharged to the outside through a path different from the previous flow path.

After the malodorous components have been desorbed for a predetermined period of time, the application of voltage to the heating elements 7, 7... is stopped by the action of the timer.
After a suitable cooling period, the fan is operated again and the activated carbon structure 1 is exposed to adsorption of malodorous components.

The activated carbon structure of the present invention has been described so far as being used as a deodorizing filter in a room, but the activated carbon structure of the present invention can also be used in conventionally known applications where activated carbon is used, such as deodorizing refrigerators 1-IC. In addition to being effectively used as a device, it can also be effectively used for solvent recovery, water treatment, etc.

Furthermore, the activated carbon structure according to the present invention can be used again in water treatment by desorbing or separating adsorbed organic substances or impurities such as chlorine by heating the activated carbon porous body.

Effects of the Invention The activated carbon structure of the present invention has carbonized plastic foam.
Since it is equipped with an activated activated carbon porous body and means for heating the activated carbon porous body, it is possible to heat the activated carbon porous body and desorb or desorb the substance adsorbed on the activated carbon porous body. Can be done. Therefore, when used as a filter, it is possible to restore the deodorizing performance that has been degraded by energization, so periodic filter replacement is not necessary. It can be used effectively.

Moreover, the activated carbon porous material used in the present invention has excellent adsorption performance.
Especially in applications such as deodorizing cigarettes, the adsorption speed is fast and the adsorption amount is large. Therefore, in the activated carbon structure according to the present invention, when the slit structure is made of a porous activated carbon material, the spacing between the slits can be increased, and the pressure loss during adsorption kneading can be further reduced.

EXAMPLES Next, the activated carbon structure of the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples as long as the gist thereof is not exceeded.

Example 1 100 parts by weight of resol, 10 parts by weight of para-toluenesulfonic acid as a curing agent, and chlorofluorocarbon gas (as a blowing agent)
After sufficiently stirring 2 parts by weight of Freon 11) with a high-speed mixer, the mixture was poured into a wooden mold and the lid was closed.
By leaving it in an air oven at 0℃ for 30 minutes,
Vertical 300+11. A plate-shaped phenolic resin foam having fM30(1), thickness of 3 cm, and bulk density of 0.10 g/cm3 was obtained.

This formed plate was placed in a Matsufuru furnace and heated under a nitrogen atmosphere at a rate of 60°C/hour to a temperature of 800°C, and then at the same temperature the molar ratio of N2 gas to water vapor was 0.8.
:0.2 was flowed, activated for 30 minutes, cooled, maintained at this temperature for 1 hour, cooled, and heated vertically.
5cm, I yellow 25 (7), thickness 2.6 (7), high density 0
．． 09g/a! A plate-like carbon porous body having a specific surface area of 1200 rrr/g and a carbon content of 90% was obtained.

[Manufacture of filter] From the above plate-shaped activated carbon porous body, thickness 5 mm, II+ 10-
(2) Rods with a length of 150 mm were cut out and arranged at intervals on a heat-resistant plastic frame to form a slit structure, thereby creating an activated carbon structure 1 as shown in FIG. The slits were spaced at 10 intervals, the number of carbon porous bodies was 9, and a thin ceramic heater was used as the heating element.

[Performance evaluation] A pressure loss chamber (internal dimensions 1m x 1m x 1.3m), a 67IIIlφ conduit connected to this chamber, a filter holder disposed in the middle of this chamber, and a filter holder disposed on each of the upstream and downstream sides of this holder. The pressure loss was determined to be 11 F1 using an apparatus having a pressure gauge and a blower for discharging air from the chamber.

In the measurement operation, after mounting the activated carbon structure on the holder, the blower is driven to blow the air in the chamber at t-100cm/s.
Eject through the conduit at a rate of ec.

At this time, the pressures on the upstream and downstream sides of the filter are measured, and the pressure difference is expressed as pressure loss (opening H20).

A deodorizing effect conduit is provided in a circulating manner so that air is recycled into the chamber. The concentration of acetaldehyde in the chamber is 1.
After introducing the solution to a concentration of 0.00 ppm, start rotating the blower. After 10 minutes, 20 minutes, and 30 minutes have elapsed, the concentration of acetaldehyde in the chamber is determined using a gas detection tube.

Deodorization rate - (Initial concentration - Concentration after 30 minutes / Initial concentration
100 (%)) The above measurement results are shown in Table 1.

Desorption and re-adsorption test After conducting an acetaldehyde adsorption test, a current was applied to the heating element to cause the ceramic heating element to generate heat, and the surface temperature of the activated carbon porous body was raised to 180°C, and a desorption operation was performed.

Next, after one hour of waiting for the filter to cool, the acetaldehyde adsorption test was conducted again. Table 1 shows the evaluation results of adsorption performance after repeating this operation five times.

The results are shown in Table 1.

Comparative Example 1 The pressure drop and deodorizing performance were measured in the same manner as in Example 1, and the acetaldehyde adsorption test was repeated three times without performing the desorption operation. Table 1 shows the evaluation results of the adsorption performance at one time.

Comparative Example 2 Urethane foam impregnated with powdered activated carbon, commercially available as a deodorizing filter (high density o, oeg / =
performance evaluation was performed in the same manner as in Comparative Example 1.

The results are shown in Table 1.

Comparative Example 3 Commercially available activated carbon fiber deodorizing filter (x55 degrees 0.0
ftg/a+1, thickness 2 mr@) in the same manner as in Comparative Example 1, and performance evaluation was performed.

The results are shown in Table 1.

table 4゜

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an example of an activated carbon structure according to the present invention. ... Activated carbon structure 5 ... Activated carbon porous body 3 ... Case 7 ... Ceramic heating element ... Power supply fee immediate

Claims (9)

[Claims] (1) An activated carbon structure comprising an activated carbon porous body formed by carbonizing and activating a plastic foam, and a heating means for heating the activated carbon porous body. (2) The activated carbon structure according to claim 1, wherein the heating means is an infrared heater. (3) The activated carbon structure according to claim 1, wherein the heating means is a heating element that generates heat when energized. (4) The activated carbon structure according to claim 1, wherein the plastic foam is a phenolic resin foam. (5) The activated carbon porous body has a bulk density of 0.05 to 0.
Activated carbon structure according to claim 1, characterized in that the carbon content is 5 g/cm^3. (6) The activated carbon porous body has a specific volume resistivity of 1 to 0.
．． 6. The activated carbon structure according to claim 1, wherein the activated carbon structure has a resistance of 0.01 Ω·cm. (7) The activated carbon porous body has a carbon content of 85 to 95
Activated carbon structure according to claim 1, characterized in that the activated carbon structure is in the range of %. (8) The activated carbon structure according to claim 1, wherein the activated carbon porous body constitutes a slit structure in which a plurality of activated carbon porous bodies are arranged at intervals. (9) The activated carbon structure according to claim 8, wherein the activated carbon porous body is a rod-shaped object.