JP2647756B2 - Method for producing composition having air cleaning power - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an air-cleaning material to clean the polluted air containing malodorous gases typified by NH ₃ and H ₂ S or the like, the air cleaning member, for example deodorizing household It can be used as an agent.

[0002]

2. Description of the Related Art Offensive odor gases in the air are removed by an adsorption method using activated carbon, a masking method using other fragrances, or a chemical method of chemically reacting odors, or reducing the discomfort. ing. However, the adsorption method using activated carbon has a problem that the deodorizing performance deteriorates in a short period of time, and the masking method using other fragrances may give a new discomfort to the fragrances, which is not a fundamental solution. As a chemical method for causing a chemical reaction, for example, there is a method of oxidizing and decomposing a malodorous gas by using ozone. However, since excess ozone is harmful to a human body, it causes new harm. That is, since it is difficult to control the amount of the chemical substance that just reacts with the odorous gas, an unnecessary chemical substance is generated, which is hardly a fundamental solution.

As a technique for solving these problems, a journal of the Textile Society of Japan (Textile and Industry), Vol. 42, No. 12 (198)
6), pages 18 to 26, describe that a complex compound obtained by reacting a ferrous compound with ascorbic acid in an aqueous solution has a deodorizing power against nitrogen compound-based odor gas. However, according to the findings of the present inventors, there is a problem that this complex compound has a weak deodorizing power against a sulfur compound-based odor gas. According to the findings of the present inventors,
This complex compound also has a problem that the deodorizing power deteriorates in a relatively short period of time.

The present inventors have invented a composition in which a reaction product obtained by contacting a metal such as iron or manganese with ascorbic acid or the like coexists with unreacted iron or manganese or the like. A patent application was filed under No. 1-280776. This composition can be manufactured at low cost, and the deterioration of the air cleaning power is extremely small, thereby solving the problems of the prior art.

[0005]

SUMMARY OF THE INVENTION The present inventor has disclosed in Japanese Patent Application No. Hei.
No. 280776, which has been obtained by further extensive research, and aims to provide a material having a new air cleaning power in a simpler process. Particularly, deodorizing material exhibiting a long period of time improved de-CH ₃ SH speed, and the de-CH ₃ SH performance is desired.

[0006]

According to the present invention, there is provided iron sulfate or iron sulfate.
Using iron chloride or iron hydroxide, divalent or trivalent or
An aqueous solution containing both iron ions is produced, and the aqueous solution is
Or an iron alloy is brought into contact and left in an oxidizing atmosphere to react.
After the formation of ferrous oxide or ferrous hydroxide, its formation
Adsorb hydrogen sulfide on the material and form iron sulfide
A method for producing a composition having a characteristic air cleaning power.
You. Further, aqueous L- ascorbic acid of claim 1, gallic acid, the coexistence of at least one organic acid selected from tannic acid, added water calcium oxide, sodium hydroxide, a basic substance such as potassium hydroxide And adjust the pH to 2
A method for producing a composition having air cleaning power, characterized in that the composition was adjusted to ~ 11.

[0007]

According to the study of the present inventors, NH ₃ and (CH ₃ ) ₃
A nitrogen-based gas such as N adsorbs very well to a metal complex or an iron oxide which is a reaction product of an acid and a metal, whereas an H ₂ S gas has a weak adsorbing power. One solution is to dispose a solid base on a metal complex as described in Japanese Patent Application No. 63-273195 by the present inventors. However, in subsequent studies, it was determined that the substances having strong adsorption power for acidic gas such as H ₂ S were ferrous hydroxide and ferrous oxide formed by dissolving metallic iron in an aqueous solution. It is generally known that iron oxide has an H ₂ S decomposing action, but the reaction rate is slow at room temperature, and it is necessary to keep the atmosphere at 200 ° C. or higher. However, studies by the inventors have revealed that ferrous hydroxide and ferrous oxide have an extremely high decomposition rate of H ₂ S even at room temperature and can be sufficiently utilized as a deodorizing material.

However, in general, ferrous hydroxide and ferrous oxide are easily oxidized to magnetite, hematite, goethite, etc. by leaving them in the air, and H ₂ S at room temperature.
In order to make a practical material because it loses decomposition performance, it is necessary to efficiently produce ferrous oxide and furthermore, to prevent the generated ferrous oxide from oxidizing to ferric oxide There is a need for a method of stabilization. Further, since ferrous oxide alone does not have NH ₃ removal performance or CH ₃ SH removal performance, conditions for establishing coexistence with other materials are also required.

[0009] de H ₂ S performance and is improved de-CH ₃ SH performance of even better is -SH group H is considered to have properties similar to H ₂ S. Therefore, it can be inferred that it is effective to effectively produce ferrous hydroxide and ferrous oxide. However, studies by the present inventors have revealed that good H ₂ S removal performance is not a sufficient condition for good CH ₃ SH removal performance. For example, iron and an aqueous solution of L-ascorbic acid are brought into contact with each other in the air, and the resulting complex salt and iron coexist
The reaction product heat-treated at 50 ° C. for 24 hours contains ferrous oxide, and has extremely good H ₂ S removal performance but slightly inferior CH ₃ SH performance. As a result of researching and studying various measures to improve the de-CH ₃ SH performance, the pH of an aqueous solution containing divalent or trivalent iron ions was adjusted to 2 to 11, and the aqueous solution was brought into contact with metallic iron to form an atmosphere. When left to dry in a medium, ferrous oxide is efficiently formed on the iron surface, and a composition having extremely excellent H ₂ S removal performance is formed.

[0010] If the pH is too low, the complex of iron and acid is excessively formed and a protective film is formed. Therefore, the formation of ferrous oxide and ferrous hydroxide is suppressed, and the nitrogen compound-based odor removing ability is suppressed. But the ability to remove hydrogen sulfide decreases. Conversely, if the pH is too high, the formation of ferrous oxide and ferrous hydroxide increases and the ability to remove hydrogen sulfide increases, but the odor removing ability of the nitrogen compound system decreases. Therefore, it is necessary to adjust the pH to 2 to 11 in order to have comprehensive air cleaning power.

The optimum point of the pH is the concentration of iron ions in the aqueous solution,
It has factors that change depending on the ratio of divalent to trivalent and the composition of the metallic iron to be brought into contact. In addition, although the optimum pH varies depending on the ambient temperature, humidity, and oxygen partial pressure at which the aqueous solution reacts with metallic iron and ferroalloys, if the pH is controlled within the above range, there is practically no problem in deodorizing ability. A composition is obtained. As a result of further study of the properties of these compositions, they found that when hydrogen sulfide was adsorbed on them, the composition changed to a composition with extremely excellent CH ₃ SH performance compared to the composition before adsorbing hydrogen sulfide. Was.

[0012] In addition, L- ascorbic acid, death diet aqueous solution
At least one kind of organic acid selected from citric acid and tannic acid
When an acid coexists and calcium hydroxide, sodium hydroxide, or the like is used as a neutralizing agent, an iron complex (including an iron alloy complex) and ferrous oxide that improve the deNH ₃ performance are simultaneously formed,
It has been found that a material excellent in all of the NH ₃ removal, the (CN ₃ ) ₃ N, and the H ₂ S removal performance can be produced. In addition, H ₂
It has also been found that when S is adsorbed, the CH ₃ SH performance is dramatically improved while maintaining the NH ₃ , (CN ₃ ) ₃ N, and H ₂ S performance.

Further, the material thus produced can maintain its performance for a long time due to the coexistence of metallic iron, and the surface of metallic iron or iron sulfide has an iron complex, iron oxide,
The inventors have found that the formation of the structure covered with iron sulfide can maintain the deodorizing performance for a longer period of time, and have completed the present invention.

Removal of CH ₃ by adsorbing hydrogen sulfide
Although the mechanism of the effect of improving the SH performance has not been fully elucidated, the hydrogen sulfide desorbing performance shows almost no deterioration even after repeated use. Is estimated to be mostly decomposed and that the residual sulfur content of the deodorizing filter is almost equal to the sulfur content of the adsorbed hydrogen sulfide. This composition produces iron sulfide and adsorbs CH ₃ SH. It is considered that the performance has been greatly improved. Next, examples of the present invention will be described.

[0015]

[Example] Urethane foam with a coarseness of 20 PPI
A fine pig iron powder of 10 μm under was applied and fired at 1150 ° C. for 2 hours in a non-oxidizing atmosphere to produce a porous iron body. Some iron porous bodies were mixed with a fine iron sulfide powder of under 20 μm or a fine powder of cobalt oxide to produce and use an iron porous body containing about 10% sulfur. One piece was about 90 mm x 80 mm x 10 mm and weighed about 40 g.

The iron porous material is made of ferrous sulfate, ferric sulfate,
It was immersed in an aqueous solution produced by appropriately mixing and mixing ferrous chloride, ferric chloride, tannic acid, L-ascorbic acid, Ca (OH) ₂ powder, and sodium hydroxide, and dried in the air for about 2 weeks. . Two deodorizing filters were manufactured using the same aqueous solution, and the deodorizing performance of each one was evaluated as it was. For each one, 100 cc of H ₂ S was adsorbed in advance and allowed to stand for 24 hours. evaluated. Table 1 shows typical examples of specific mixing ratios, and Table 2 shows the pH of the aqueous solution corresponding to them and the results of evaluating the deodorizing performance.

[0017]

[Table 1]

[0018]

[Table 2]

The deodorizing performance is 40 liters in a sealed container.
Install a circulation fan with a blowing capacity of 0 liters / minute,
As shown in FIG. 1, NH ₃ , (CH ₃ ) ₃ N, H ₂ S, CH ₃
The SH removal performance was examined. The initial value is NH ₃ is 1000p
pm, (CH ₃ ) ₃ N is 100 ppm, H ₂ S is 500 pp
m and CH ₃ SH were set to 50 ppm, and after 10 minutes,
The residual concentration after 0 minute was measured, and the removal rate was determined as the deodorization rate. The CH ₃ SH performance was greatly improved by the adsorption of H ₂ S, and the other deodorization performance was hardly affected. In the subsequent repeated CH ₃ SH test, it was confirmed that the improvement effect was maintained.

[0020]

According to the present invention, an air-purified product and a deodorizing filter having high CH ₃ SH performance can be manufactured.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing the structure of a test device for evaluating the deodorizing performance.

[Explanation of symbols]

1: closed container, 2: circulation fan, 3: deodorizing filter, 4: gas inlet, 5: gas sampling port,
6: Direction of gas circulation.

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical display location B01D 53/38 B01D 53/34 116D 53/77 (56) References JP-A-4-219136 (JP) JP-A-4-220257 (JP, A) JP-A-4-235736 (JP, A) JP-A-4-219137 (JP, A) JP-A-3-174216 (JP, A) JP 55-34164 (JP, A) JP-A-62-254840 (JP, A)

Claims (2)

(57) [Claims] 1. Use iron sulfate, iron chloride or iron hydroxide
Aqueous solution containing divalent or trivalent or both iron ions
Oxidized by contacting iron or iron alloy with the aqueous solution
Leave it in the atmosphere and let it react to ferrous oxide or hydroxide
After forming iron, the product adsorbs hydrogen sulfide and
A method for producing a composition having air cleaning power, characterized in that iron fossil is formed . 2. The aqueous solution according to claim 1, wherein L-ascorbic acid is added to the aqueous solution.
At least one of gallic acid and tannic acid
Organic hydroxide, calcium hydroxide, sodium hydroxide
And a basic substance such as potassium hydroxide to adjust the pH to 2
A process for producing a composition having air cleaning power, characterized in that the composition is adjusted to ~ 11 .