JPH0615034B2 - Air purifier - Google Patents

Description

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

[Conventional technology]

The adsorbent in which aniline is impregnated on activated carbon is Japanese Patent Publication No. 60-54095.
It is disclosed in Japanese Patent Laid-Open Publication No. 2003-242242 that 100 parts of activated carbon and 1 to 30 parts of aniline are effective for adsorbing lower aliphatic aldehydes such as formaldehyde and acetaldehyde in a gas phase.

Furthermore, a technique of impregnating a porous substance such as activated carbon with an inorganic acid such as sulfuric acid or phosphoric acid to be used as a deodorant is a known technique, and has been put into practical use as an excellent adsorbent for ammonia and lower amines. .

[Problems that the invention is trying to solve]

Activated carbon is a unique material that has extremely excellent adsorptivity as a non-polar adsorbent, and exhibits high adsorptivity for almost all gaseous substances. Indoor air in living spaces such as offices and homes usually has a strong cigarette odor, and compositionally contains acetaldehyde, ammonia, lower amines, hydrocarbons, hydrogen sulfide and the like. Here, the odor of cigarette means the odor of gas generated when smoking. In particular, the ratio of ammonia, which is a weak point of adsorptivity of activated carbon, is high, and it is difficult to remove the odor with only a porous substance such as ordinary activated carbon because there are relatively many lower aliphatic aldehydes.
There has been a demand for an adsorbent that efficiently and completely removes these components.

[Means for solving problems]

The inventors of the present invention additionally conducted a test in which only aniline was impregnated on the activated carbon, and additionally, newly activated carbon was impregnated with an aniline phosphate alone, as well as those impregnated with both of the aniline phosphate and aniline were lower aliphatic aldehydes. gas,
The adsorption of ammonia gas and hydrogen sulfide gas and the desorption of aniline gas were investigated. As a result, they have found that activated carbon impregnated with aniline and aniline phosphate is excellent in adsorbing lower aliphatic aldehyde gas, ammonia gas, hydrogen sulfide gas, etc., and hardly desorbing aniline gas, and thus reached the present invention. did. That is, it is an air purifying agent obtained by impregnating activated carbon with aniline and aniline phosphate.

The present invention will be described in detail below.

The activated carbon used here usually has a large surface area of several hundred m ² or more per 1 g, and can be used in a wide range as long as it is a carbon material exhibiting high adsorptivity. As the raw material of the activated carbon, a charcoal such as coconut shell or wood or coal is usually used, but any may be used. Further, the activation method may be obtained by steam or carbon dioxide at a high temperature or by any method such as treatment with zinc chloride, phosphoric acid or concentrated sulfuric acid.

Although the shape of crushed coal, granulated coal or granulated coal is effective, a sheet-shaped adsorbent impregnated with granulated coal or activated carbon is convenient in handling such as pressure loss destination and replacement. The granulated coal is prepared by adding 30 to 60 parts of petroleum pitch or coal tar as a binder to 100 parts of a carbon material as a binder, and activating after kneading and molding.

Activated carbon impregnated with aniline and aniline phosphate has very good adsorption properties for lower aliphatic aldehyde gas such as formaldehyde and acetaldehyde gas, ammonia gas and hydrogen sulfide gas, and almost no desorption of aniline gas. Since the aniline phosphate is insoluble in water and alcohols such as methanol or ethanol, the suspension of the aniline phosphate can be sprinkled on the activated carbon.
The impregnated portion is a macropore of a porous material such as activated carbon,
It is presumed to be a crack or a surface portion. However, in this case, if the amount of the aniline phosphate impregnated is too large, the surface encapsulation will be peeled off, and further, the adsorption of hydrogen sulfide gas and other substances of the impregnated activated carbon will be inhibited, and if the amount impregnated is too small, Since the intended effect becomes poor, the amount of the aniline phosphate impregnated is preferably selected from the range of 1 to 30 parts, preferably 1 to 10 parts per 100 parts of activated carbon. It should be noted that aniline was added to this aniline phosphate impregnated carbon as activated carbon.
It has been found that when the amount of 1 part to 30 parts, preferably 1 to 8 parts per 100 parts is impregnated, the adsorption power of hydrogen sulfide gas can be maintained at the same level as unimpregnated carbon without adversely affecting the adsorption of aldehyde gases.

[Work]

Originally, activated carbon has high adsorptivity for almost all gaseous substances as a non-polar adsorbent, but it has a relatively high adsorptivity for lower aliphatic aldehydes, which are relatively contained in the odor of tobacco. weak. Also, the amount of adsorption of ammonia, which has a high ratio in the tobacco odor, is very small. However, the present invention is excellent in adsorbability of these lower aliphatic aldehyde gas and ammonia gas, and has aniline and aniline phosphate salt impregnated on activated carbon in order to eliminate elimination of aniline gas at all.

The action of the activated carbon impregnated with aniline and aniline phosphate to adsorb ammonia gas is considered to be due to neutralization. Further, even if the gas concentration fluctuates, it is difficult to re-release the gas once adsorbed. This is probably because the adsorption of ammonia gas depends on the chemical reaction mechanism. The adsorption of external amines of ammonia gas is high, and the mechanism is considered to be similar.

Next, as an adsorbent for aldehydes, an adsorbent obtained by impregnating a porous substance such as activated carbon with a sulfite or an acidic sulfite is known, and the aniline and the aniline phosphate-impregnated carbon used in the present invention are known. Compared with this, the adsorption of lower aliphatic aldehyde is much higher, and it is excellent especially in the low concentration region (aldehyde concentration 100 ppm or less). Next, hydrogen sulfide gas is easily adsorbed on activated carbon, but when an acidic substance is impregnated, the adsorbing power decreases.

If the amount of aniline phosphate alone is increased, the amount of hydrogen sulfide gas adsorbed decreases. This is considered to be the effect of the acid generated by decomposition in the activated carbon pores. Therefore, it is considered that the hydrogen sulfide gas adsorption capacity can be maintained without being adversely affected by the acid by impregnating the aniline phosphate and the basic aniline within the proper amount of impregnation.

When aniline is impregnated, safety and hygiene considerations are required, but in the case of the present invention, since aniline phosphate is impregnated, elimination of aniline does not pose any problem. By the way, aniline phosphate is added to 100 parts of activated carbon for 10 or 2
Odors when 0,30 parts and 8 parts of aniline were left in a closed container at room temperature (25 ° C) were analyzed by sensory test and high sensitivity gas chromatograph with FID (flame ionization detector). No odor was sensed by the sensory test, and aniline was not detected by gas chromatography. This performance is extremely advantageous when the product of the present invention is used as an air purifying agent.

〔Example〕

Hereinafter, the present invention will be specifically described with reference to examples, but these examples do not limit the present invention in any way.

Example 1 A suspension obtained by suspending 4 parts of fine powder obtained by crushing aniline phosphate crystals to 100 mesh or less with 100 parts of granular coconut shell activated carbon of 8 to 20 mesh having ordinary adsorption capacity in 20 parts of water. Was prepared, and the aqueous suspension of aniline phosphate was sprinkled while stirring well with activated carbon. Then, the activated carbon impregnated was dried in a dryer at a temperature of 120 ° C for 3 hours, placed in a closed container, and sprinkled with 2 parts of aniline and left in a thermostatic chamber at a temperature of 40 ° C for 40 hours in an airtight state. Attached to. Similarly, a comparative sample was prepared by impregnating 8 parts of aniline phosphate with 100 parts of activated carbon. Next, a comparative sample was prepared in which 4 parts of aniline was impregnated with 100 parts of activated carbon. The following experiments were conducted using these samples.

A circulation system adsorption rate measuring device in which a glass bottle having a capacity of 30, a glass tube column having a diameter of 39 mm and a diaphragm pump were connected was used. Acetaldehyde gas having a concentration of 50 ppm is prepared in a glass bottle having a volume of 30, and 2.8 g of a sample is filled in the column. The gas is circulated at a flow rate of 27 / min to adsorb acetaldehyde gas.

The gas in the glass bottle was sampled at regular intervals, and the acetaldehyde gas concentration was analyzed by a high-sensitivity gas chromatograph with FID.

Column packing samples were activated carbon (unimpregnated carbon) and 100 parts activated carbon with 4 parts aniline impregnated with 8 parts aniline phosphate and 4 parts aniline phosphate and 2 parts aniline impregnated. FIG. 1 shows the results of a comparison of the changes over time in the residual concentration ratio when the initial concentration was 100%.

Example 2 Desorption of aniline, aniline phosphate and aniline phosphate which had been impregnated and aniline were examined. 100g sample in a 50mmφ glass tube column set in a constant temperature bath at a temperature of 50 ℃
Filled with fresh air with a temperature of 50 ° C and a flow rate of 470m
/ min. The aniline gas concentration in the outlet gas was analyzed by a high-sensitivity gas chromatograph with FID. As column packing samples, 100 parts of activated carbon prepared in Example 1 and 4 parts of aniline, 8 parts of aniline phosphate and 4 parts of aniline phosphate and 2 parts of aniline were used. Results are shown in FIG.

Example 3 A glass bottle having a volume of 3.97 was charged with 2 g of a sample in anhydrous form and deaerated with a vacuum pump, and then a predetermined amount of ammonia water was added to be vaporized.

Next, air was introduced and the pressure was returned to normal pressure, and then it was left in a constant temperature bath at a temperature of 25 ° C., and the ammonia gas concentration was measured with a gas detector tube. When the equilibrium was reached, the relationship between the amount of adsorbed ammonia and the gas concentration was investigated, and the isothermal adsorption line was measured. Activated carbon (unimpregnated carbon)
And the results of 100 parts of activated carbon prepared in Example 1 and 4 parts of aniline, 8 parts of aniline phosphate and 4 parts of aniline phosphate and 2 parts of aniline. Shown in the figure.

Example 4 A glass bottle having a volume of 3.97 was charged with 2 g of a sample in anhydrous form and deaerated with a vacuum pump, and then a predetermined amount of hydrogen sulfide gas was added. Next, air was introduced and the pressure was returned to normal pressure, and then it was left in a constant temperature bath at a temperature of 25 ° C., and the concentration of hydrogen sulfide gas was measured with a detector tube. Activated carbon (unimpregnated carbon) and activated carbon prepared in Example 1
The results for 100 parts of which 4 parts of aniline are impregnated, 8 parts of aniline phosphate adsorbed and 4 parts of aniline phosphate salt and 2 parts of aniline impregnated are shown in FIG.

Example 5 Using the same adsorption rate measuring device as in Example 1, a concentration of 50 ppm
The hydrogen sulfide gas is prepared in a glass bottle having a capacity of 30, and the column is filled with 2.8 g of the sample. The gas is circulated at a flow rate of 27 / min to adsorb hydrogen sulfide gas.

The gas in the glass bottle is sampled at regular intervals to determine the hydrogen sulfide gas concentration by FPD (flame photometric detector Flame photometr
High sensitivity gas chromatograph with ic detector).

Activated carbon (unimpregnated carbon) and activated carbon 100 prepared in Example 1
FIG. 5 shows the results for those in which 4 parts of aniline was attached to 8 parts, those in which 8 parts of aniline phosphate was attached, and those in which 4 parts of aniline phosphate and 2 parts of aniline were attached.

[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. Further, since it has a strong adsorption power for lower aliphatic aldehyde gas, ammonia gas, hydrogen sulfide gas, etc., it is suitable for removal immediately after extinguishing a petroleum stove. Therefore, it is suitable for a filter of an air cleaner.

[Brief description of drawings]

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 …… Aniline 4 parts was attached to 100 parts of activated carbon. 3 ... 8 parts of aniline phosphate is added to 100 parts of activated carbon. 4 ... 4 parts of aniline phosphate and 2 parts of aniline are attached to 100 parts of activated carbon. FIG. 2 shows the aniline detachability from the impregnated activated carbon at a temperature of 50 ° C. 1 ... 4 parts of aniline is attached to 100 parts of activated carbon. 2 ... 8 parts of aniline phosphate is added to 100 parts of activated carbon. 3 ... 4 parts of aniline phosphate and 2 parts of aniline are attached to 100 parts of activated carbon. FIG. 3 shows an isotherm adsorption line of ammonia gas at a temperature of 25 ° C. and a relative humidity of 60%. 1 …… Activated carbon (unattached) 2 …… Aniline 4 parts was attached to 100 parts of activated carbon. 3 ... 8 parts of aniline phosphate is added to 100 parts of activated carbon. 4 ... 4 parts of aniline phosphate and 2 parts of aniline are attached to 100 parts of activated carbon. FIG. 4 shows isothermal adsorption lines of hydrogen sulfide gas at a temperature of 25 ° C. and a relative humidity of 60%. 1 …… Activated carbon (unimpregnated carbon) 2 …… Impact 4 parts of aniline on 100 parts of activated carbon. 3 ... 8 parts of aniline phosphate is added to 100 parts of activated carbon. 4 ... 4 parts of aniline phosphate and 2 parts of aniline are attached to 100 parts of activated carbon. FIG. 5 shows the adsorption rate of hydrogen sulfide gas at a temperature of 25 ° C. and a relative humidity of 30%. 1 …… Activated carbon (unimpregnated carbon) 2 …… Impact 4 parts of aniline on 100 parts of activated carbon. 3 ... 8 parts of aniline phosphate is added to 100 parts of activated carbon. 4 ... Both 100 parts of activated carbon and 4 parts of aniline phosphate and 2 parts of aniline are impregnated.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Uchida 4125 Tsurumi, Bizen City, Okayama Prefecture

Claims (2)

[Claims] 1. An air purification agent obtained by impregnating activated carbon with aniline and aniline phosphate. 2. The air purifying agent according to claim 1, wherein 1 part to 30 parts of aniline and 1 part to 30 parts of aniline phosphate are attached to 100 parts of activated carbon.