JPH0252043A - Air purifying agent - Google Patents

Abstract

PURPOSE:To obtain an air purifying agent especially adsorbing lower aliphatic aldehyde gas, ammonia gas or the like by adding an aniline salt of an inorg. acid to a porous substance such as activated carbon. CONSTITUTION:As an air purifying agent especially effective for removing a tobacco smell in indoor air of an office or home, 1-30 pts. of an aniline salt of an inorg. acid or an inorg. acid and aniline is added to 100 pts. of a porous substance such as activated carbon. The air purifying agent thus obtained is excellent in the adsorbability of lower aliphatic aldehyde and ammonia gas and no desorption of aniline gas is generated at all. Further, even when the concn. of gas is varied, the re-discharge of gas once adsorbed is not generated. Therefore, this purifying agent is effective for the removal of a smell in usual living environment.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an air purifying agent, and is particularly effective in removing tobacco odor from indoor air in offices, homes, and the like.

[Conventional technology]

The impregnant, which impregnates activated carbon with aniline, was published in 1986-54 by the Special Publication.
095, in which 100 parts of activated carbon is added with 3 to 30 parts of aniline, formaldehyde in the gas phase,
It is described as being effective in adsorbing lower aliphatic aldehyde gases such as acetaldehyde.

Furthermore, the use of porous materials such as activated carbon as impregnated with inorganic acids such as sulfuric acid and phosphoric acid for use as deodorizers is already a well-known technology and has been put to practical use as an excellent adsorbent for ammonia and lower amines. .

[Problems to be Solved by the Invention] Activated carbon is a unique material that has extremely excellent adsorption properties as a non-polar adsorbent, and exhibits high adsorption properties for almost all gaseous substances. Indoor air in living spaces such as offices and homes usually has a strong odor of tobacco, and its composition includes acetaldehyde, ammonia, lower amines, hydrocarbons, hydrogen sulfide, and the like.

Note that the cigarette odor here refers to the odor of gas generated when smoking. In particular, activated carbon has a high proportion of ammonia, which is a weak point in its adsorption properties, and also contains a relatively large amount of lower aliphatic aldehydes, making it difficult to remove the odor using only porous materials such as ordinary activated carbon. There is a need for an adsorbent that can efficiently and completely remove

[Failure to solve the problem]

The present inventors conducted a follow-up experiment on the case in which only aniline was impregnated with activated carbon, and also conducted a new study on porous materials such as activated carbon impregnated with an inorganic acid aniline salt, or impregnated with both an inorganic acid and aniline. The adsorption properties of aliphatic aldehyde gas and ammonia gas, as well as the desorption properties of aniline gas, etc., were investigated. As a result, those impregnated with an inorganic acid aniline salt or those impregnated with both an inorganic acid and aniline are superior in adsorbing lower aliphatic aldehyde gas and ammonia gas, compared to those impregnated with only aniline. Furthermore, the present invention was achieved by discovering that there was no desorption of aniline gas at all.

That is, it is an air purifying agent made by impregnating a porous material such as activated carbon with an inorganic acid aniline salt or both an inorganic acid and aniline.

The present invention will be explained in detail below.

The activated carbon used here usually has a large surface area of several hundred square meters or more, and can be used in a wide range of carbon materials as long as they exhibit high adsorption properties.

The raw material for activated carbon is usually carbonized material such as coconut shell or wood, or coal, but any of them may be used. Further, the activation method may be one obtained by using water vapor or carbon dioxide at high temperature, or by other methods such as treatment with zinc chloride, phosphoric acid, or concentrated sulfuric acid.

Although the effect can be recognized in any form of crushed coal, granulated coal, or granulated coal, a sheet-like adsorbent impregnated with granulated carbon or activated carbon is convenient in terms of handling such as pressure loss and replacement. Granulated coal is made by adding 30 to 60 parts of petroleum pitch or coal tar as a binder to 100 parts of carbon material according to the usual method.
It is prepared by activating after mixing and molding.

Note that a wide range of porous substances other than activated carbon can be used, such as zeolite, alumina, silica gel, pumice, urethane foam, fibers, paper, and cloth.

The activated carbon porous substance impregnated with an inorganic acid aniline salt exhibits extremely good adsorption properties for lower aliphatic aldehyde gas, ammonia gas, etc., and there is no desorption of aniline gas, and the impregnated amount is not particularly limited. Furthermore, the type of inorganic acid constituting the salt is not particularly limited. However, when impregnating phosphoric acid aniline salt, it is difficult to dissolve in water and alcohols such as methanol or ethanol, so the suspension is sprinkled onto porous materials such as activated carbon. In this case, the impregnated portion is presumed to be the macrobore, cracks, or surface portion of a porous material such as activated carbon. However, in this case, if the amount of phosphoric acid aniline salt impregnated is too large, the surface impregnated material will peel off9, and furthermore, the adsorption of other substances by the impregnated porous material such as activated carbon will be inhibited.
Moreover, if the amount of impregnation is too small, the desired effect of the present invention will be poor, so the amount of impregnated ani+7 salt of phosphate should be selected within the range of 1 to 30 parts per 100 parts of porous material such as activated carbon. preferable.

On the other hand, when impregnating aniline sulfate, aniline hydrochloride, aniline nitrate, etc., these are soluble in water, so it is sufficient to use an aqueous solution of them, but the amount of impregnation is limited to the porous activated carbon etc. for the reasons stated above. It is preferable to select from a range of 1 to 30 parts per 100 parts of the sexual substance.

On the other hand, porous materials such as activated carbon impregnated with both inorganic acid and aniline also exhibit extremely good adsorption properties for lower aliphatic aldehyde gases, ammonia gas, etc., and there is no desorption of aniline gas; Noso MfIk
is not particularly limited. Furthermore, the type of inorganic acid is not particularly limited. In order to impregnate a porous material such as activated carbon with aniline and an inorganic acid such as phosphoric acid, sulfuric acid, hydrochloric acid, or nitric acid, the inorganic acid is impregnated after the aniline is impregnated.

However, if the amount of aniline impregnated is too large, it will inhibit the adsorption of other substances by porous materials such as activated carbon, have a negative effect on K and inorganic acids, reduce the adsorption performance of ammonia gas, etc. If the amount is too small, the purpose of the present invention will be impaired, so the impregnated amount of aniso/
It is preferable to select from the range of 1 to 35 parts per 00 parts. On the other hand, the amount of the inorganic acid impregnated is not particularly limited. However, if the amount of impregnated inorganic acid increases, the adsorption of other substances by the porous material such as activated carbon will be inhibited, and the purpose of the present invention will be impaired.
It is preferable to select within the range of 1 to 35 parts. In order to first impregnate aniline onto a porous material such as activated carbon, it can be prepared by sprinkling an aniline solution or by adsorbing aniline gas in a gas phase. Next, to impregnate an inorganic acid, the material is immersed in an inorganic acid solution so that it is sufficiently absorbed into the pores of a porous material such as activated carbon, and then dried separately with P or sprinkled with solution gold to ensure sufficient impregnation. You can also dry things. Since it is important to uniformly impregnate the inorganic acid into the pores and react with the aniline, it is necessary to dry slowly. If the drying speed is too fast, the inorganic acid that was once adsorbed inside will be desorbed and deposited on the surface of porous materials such as activated carbon.
There is a risk that its performance will deteriorate.

[Effect]

Activated carbon is originally a non-polar adsorbent and exhibits high adsorption properties for almost all gaseous substances, but it has relatively low adsorption power for lower aliphatic aldehyde gases, which are relatively abundant in cigarette odor etc. is weak. In addition, the adsorption amount for ammonia gas, which has a high proportion in tobacco odor, is very small. Therefore, the present invention has excellent adsorption properties for these lower aliphatic aldehyde gases and ammonia gas, etc., and completely eliminates the desorption of aniline gas. It is attached.

It is thought that the effect of a porous substance such as activated carbon impregnated with an inorganic acid aniline salt or both an inorganic acid and aniline to adsorb ammonia gas is due to neutralization. Furthermore, even if the gas concentration fluctuates, it is difficult to re-release the gas once adsorbed. This is considered to be because the adsorption of ammonia gas is based on a chemical reaction mechanism. In addition to ammonia gas, it also has high adsorption properties for amines.
The mechanism is thought to be similar.

Next, as an adsorbent for aldehydes, adsorbents made by impregnating sulfite or acidic sulfite on porous materials such as activated carbon are known, but the inorganic acid aniline salt or the inorganic acid and aniline used in the present invention A porous material such as activated carbon impregnated with both of these materials has a much higher adsorption ability for lower aliphatic aldehyde gas, and is particularly excellent in a low concentration region where the aldehyde gas concentration is 100 PPM or less.

When Ani-17 is fAWt, safety and health considerations are required, but in the case of the present invention, since an inorganic acid aniline salt or both an inorganic acid and aniline are impregnated, Ani-17 is impregnated with fAWt.
Detachment is not a problem at all.

Aniline is added to the porous material such as activated carbon to which the inorganic acid is impregnated in advance for the following reason.

Lower aliphatic aldehydes such as formaldehyde gas and acetaldehyde gas are physically adsorbed to some extent by porous materials such as activated carbon, but their retention force is small, so clean air is absorbed by porous materials such as activated carbon that have been adsorbed above the retention limit. When the water flows, the lower aliphatic aldehydes that were once adsorbed are re-released. Furthermore, since the olfactory threshold of aldehyde gas is at a low concentration, there is an odor peculiar to aldehyde gas, and the use of a porous material such as activated carbon impregnated with only an inorganic acid may have an adverse effect. Therefore, porous materials such as activated carbon that chemically adsorb ammonia gas and amines are also treated with aniline to chemically adsorb lower aliphatic aldehydes.

〔Example〕

The present invention will be specifically described below with reference to Examples, but these Examples are not intended to limit the present invention in any way.

Example 1 An activated carbon sample impregnated with phosphoric acid aniline salt was prepared as follows.

A suspension is prepared by suspending fine powder 8F4, which is obtained by crushing phosphoric acid aniline salt crystals into 100 mesh or less, in 40 parts of water, using 100 parts of granular coconut shell activated carbon of 8 to 2 mesh having normal adsorption capacity. While stirring the activated carbon well, add the aqueous suspension of phosphoric acid aniline salt little by little.
I put it on. Thereafter, the impregnated activated carbon was dried in a dryer at a temperature of 120°C for 3 hours to prepare a sample.

In addition, an activated carbon sample impregnated with aniline sulfate was prepared as follows. An aqueous solution prepared by dissolving 12 parts of aniline sulfate in 40 parts of water was sprinkled little by little on 100 parts of granular coconut shell activated carbon having a normal adsorption capacity of 8 to 20 mesh while stirring the activated carbon well.

Thereafter, the impregnated activated carbon was dried in a dryer at a temperature of 120°C for 3 hours to prepare a sample.

For comparison, 100 parts of the same activated carbon was placed in a sealed container, covered with 4 parts of Ayu 9F, and left in a sealed container at a temperature of 40°C for 40 hours, so that aniline was evenly attached to the entire activated carbon. Similarly, 9 parts of sweetfish and 8 parts of sweetfish were attached to 100 parts of activated carbon to prepare a sample. Then, the adsorption rate of acetaldehyde gas was investigated using these samples.

A circulation system adsorption rate measuring device was used, which consisted of a glass bottle with a capacity of 301 cm, a 39-volume glass tube column, and a 7-diamond bong connected in reverse. Prepare acetaldehyde gas at a concentration of 5 Q PPM in a glass bottle with a volume of 301 ff, and fill the column with sample 2.82. Gas is circulated at a flow rate of 271/min to adsorb acetaldehyde.

The gas in the glass bottle was sampled at regular intervals, and the acetaldehyde gas concentration was analyzed using a high-sensitivity gas chromatograph with FID. Activated carbon 10 as column filling sample
0 part with 4 parts and 8 parts of aniline impregnated, 8 parts of phosphoric acid aniline salt, and sulfuric acid aniline salt 12 parts
For the two parts added, the change in concentration residual rate over time was measured when the initial concentration was set as 100%, and the results are shown in FIG.

Example 2 Using the sample prepared in Example 1, the desorption property of aniline gas was investigated.

59 mm O set in a constant temperature bath at a temperature of 50°C
A glass tube column was filled with 100 f of sample, and the temperature was 50
Fresh air at °C was passed through at a flow rate of 470 ml/min, and the aniline gas concentration in the outlet gas was analyzed using a high-sensitivity gas clot graph with FIDID. Desorption performance of aniline gas was measured for column-filled samples of 100 parts of activated carbon impregnated with 4 or 8 parts of aniline, 8 parts of aniline phosphate, and 12 parts of aniline sulfate. The results are shown in Figure 2.

Example 3 Using the sample prepared in Example 1, the adsorption amount of ammonia gas was investigated.

Sample 2 is placed in a glass bottle with a capacity of 3.971 cm, and after degassing with a vacuum pump, a predetermined amount of ammonia water is added and vaporized. Next, add air and return to normal pressure, then the temperature is 25°.
The sample was left in a constant temperature chamber of C, and the ammonia gas concentration was analyzed using a gas detector. The relationship between the ammonia gas concentration and the gas concentration when equilibrium is reached is measured for samples with 100 parts of activated carbon impregnated with 8 parts of aniline and 8 parts of phosphoric acid aniline salt. The results expressed as MH are shown in FIG.

Example 4 The adsorption amount of ammonia gas was investigated in a sample prepared in the same manner as in Example 1 using 16 to 24 mesh granular zeolite instead of activated carbon. 100 parts of zeolite impregnated with 8 parts of aniline and 8 parts of phosphoric acid aniline salt were measured in the same manner as in Example 3, and the results are shown in Figure 4 as an ammonia gas isothermal adsorption line. show.

Example 5 Activated carbon samples impregnated with both phosphoric acid or sulfuric acid and anilium were prepared as follows.

For 100 parts of granular coconut shell activated carbon of 8 to 20 meshes with normal adsorption capacity, at the solid content ratio shown in Table 1,
First, an aniline solution and then a phosphoric acid aqueous solution with a concentration of 85% or a sulfuric acid aqueous solution with a concentration of 95% were thoroughly stirred little by little and poured onto the solution.Then, the sample was left sealed overnight at a temperature of 40''C.

Using these samples, the adsorption amount of acetaldehyde gas was investigated.

Sample 2f is placed in a glass bottle with a capacity of 3.971 cm, and after degassing with a vacuum pump, a predetermined amount of acetaldehyde water is added and vaporized. Next, air was introduced to return the pressure to normal pressure, and the mixture was left in a constant temperature bath at a temperature of 25° C., and the acetaldehyde gas concentration was analyzed using a high-sensitivity gas chromatograph with FID. The relationship between the amount of acetaldehyde adsorbed and the gas concentration when equilibrium is reached is measured, and the results are shown in FIG. 5, which is expressed as an acetaldehyde gas isothermal absorption M line.

Table 1 Example 6 The acetaldehyde gas absorption M amount of a sample prepared in the same manner as in Example 5 using 16 to 24 mesh granular zeolite instead of activated carbon was investigated. A product made of 100 parts of zeolite, 8 parts of aniline, and 28 parts of sulfuric acid was measured in the same manner as in Example 5, and the results are shown in FIG. 6, which is expressed as an acetaldehyde gas isothermal adsorption line.

Example 7 Using the sample prepared in Example 5, the desorption property of aniline gas was investigated. 100 parts of activated carbon, 8 parts of aniline and 28 parts of phosphoric acid, 16 parts of aniline and 28 parts of phosphoric acid ft2
FIG. 7 shows the results of measuring the desorption properties of aniline gas in the same manner as in Example 2 for a sample prepared with 8 parts of aniline and a sample prepared with 8 parts of aniline and 4 parts of sulfuric acid.

Example 8 Using the sample prepared in Example 5, the adsorption amount of ammonia gas was investigated. 100 parts of activated carbon impregnated with 8 parts of aniline and 28 parts of phosphoric acid, 16 parts of aniline and 2 parts of phosphoric acid
8 parts of aniline and 28 parts of sulfuric acid were impregnated, and 16 parts of aniline and 28 parts of sulfuric acid were measured in the same manner as in Example 3. The results are shown in Fraction 8 diagram as an ammonia gas isothermal adsorption line.

〔effect〕

As described above, the air purifying agent of the present invention is particularly effective in removing odors in ordinary living environments such as offices and homes. Furthermore, since it has a strong adsorption power for lower aliphatic aldehyde gas and ammonia gas, it is also suitable for removing odors immediately after extinguishing a kerosene stove and for removing odors from abandoned mines from vacuum cleaners. Therefore, it is suitable for air cleaner filters, etc.

[Brief explanation of the drawing]

FIG. 1 shows the adsorption rate of acetaldehyde gas at a temperature of 25° C. and a relative humidity of 30%. 1. Activated carbon (unattached) 2. 4 parts of aniline was attached to 100 parts of activated carbon. 3. Deposit 8 parts of aniline on 100 parts of activated carbon. 4. Deposit 8 parts of phosphoric acid aniline salt on 100 parts of activated carbon. 5. Impregnate 12 parts of sulfuric acid aniline salt to 100 parts of activated carbon. FIG. 2 shows the ability to remove aniline from impregnated activated carbon at a temperature of 50°C. 1. Deposit 4 parts of aniline on 100 parts of activated carbon. 2. Deposit 8 parts of aniline on 100 parts of activated carbon. 3. Deposit 8 parts of phosphoric acid aniline salt on 100 parts of activated carbon. 4. 12 parts of sulfuric acid aniline salt was deposited on 100 parts of activated carbon. Figure 3 shows the isothermal adsorption line of ammonia gas at a temperature of 25° C. and a relative humidity of 60%. 1. Activated carbon (unattached). 2. Deposit 8 parts of aniline on 100 parts of activated carbon. 3. Deposit 8 parts of phosphoric acid aniline salt on 100 parts of activated carbon. FIG. 4 shows the isothermal adsorption line of ammonia gas at a temperature of 25° C. and a relative humidity of 60%. 1. Zeolite (unattached). 2. Deposit 8 parts of aniline on 100 parts of zeolite. 3. Deposit 8 parts of phosphoric acid aniline salt on 100 parts of zeolite. FIG. 5 shows the isothermal adsorption line of acetaldehyde gas at a temperature of 25° C. and a relative humidity of 60%. 1. Activated carbon (unattached). 2. Add 8 parts of aniline and 28 parts of phosphoric acid to 100 parts of activated carbon. 3. Impregnate 16 parts of aniline and 28 parts of sulfuric acid to 100 parts of activated carbon. 4. 100 parts of activated carbon, 16 parts of aniline and 28 parts of phosphoric acid
Department attached. FIG. 6 shows the isothermal adsorption line of acetaldehyde gas at a temperature of 25° C. and a relative humidity of 60%. 1. Zeolite (not served). 2. 8 parts of aniline and 28 parts of phosphoric acid to 100 parts of zeolite
Department attached. 3. Add 16 parts of aniline and 2 parts of sulfuric acid to 100 parts of zeolite.
8 parts (4, Zeolite) 16 parts of aniline and 28 parts of phosphoric acid are attached to 100 parts. FIG. 7 shows the ability to remove aniline from impregnated activated carbon at a temperature of 50°C. 1. Deposit 4 parts of aniline on 100 parts of activated carbon. 2. Deposit 8 parts of aniline on 100 parts of activated carbon. 3. Add 8 parts of aniline and 28 parts of phosphoric acid to 100 parts of activated carbon. 4. Add 8 parts of aniline and 28 parts of sulfuric acid to 100 parts of activated carbon. FIG. 8 shows the isothermal adsorption line of ammonia gas at a temperature of 25° C. and a relative humidity of 60%. 1. Activated charcoal (unadded charcoal). 2. Add 8 parts of aniline and 28 parts of phosphoric acid to 100 parts of activated carbon. 3. Deposit 8 parts of aniline and 28 parts of sulfuric acid on 100 parts of activated carbon.

Claims (4)

[Claims] (1) An air purifying agent made by impregnating one or more types of inorganic acid aniline salts with a porous substance such as activated carbon. (2) The air purifying agent according to claim 1, wherein 1 to 30 parts of an inorganic acid aniline salt is impregnated with 100 parts of a porous material such as activated carbon. (3) An air purifying agent made by impregnating an inorganic acid and aniline with a porous material such as activated carbon. (4) 1 to 35 parts of inorganic acid to 100 parts of porous material such as activated carbon
5. The air purifying agent according to claim 4, wherein 1 to 35 parts of aniline and 1 to 35 parts of aniline are impregnated.