JPH0647274A - Air cleaning material and its production - Google Patents

Abstract

PURPOSE:To provide the air cleaning material which efficiently purifies the contaminated air containing malodorous gas represented by ammonia or hydrogen sulfide, etc., by forming composite oxide of iron and yttrium on the surface of the carrier consisting of an iron molding body. CONSTITUTION:The iron molding body is allowed to contact with the aq. soln. of yttrium salt and allowed to react under the atmosphere, and hear-treated at 200-350 deg.C under the condition in which reactional product coexists with unreacted metallic iron. Preferably, basic materials (e.g. calcium hydroxide) and iron salt (e.g. iron nitrate) are added to the aq. soln. of yttrium salt. The deodorizing filter 3 is made by using the air cleaning material obtained in this way and provided on the holder 7 of the sealed vessel 1 provided with the gas inlet 4 and gas outlet 5, and gas is circulated with the circulation fan 2. Thus the deodorizing filter having eliminating performance of hydrogen sulfide is obtained by convenient process.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air purification product for purifying contaminated air containing odorous gases such as ammonia and hydrogen sulfide, and a method for producing the same. The air-purified product of the present invention can be used as, for example, a household deodorant or a vehicle deodorant.

[0002]

2. Description of the Related Art Conventionally, as a method for treating malodorous gas in the air, for example, an adsorption method using activated carbon, a masking method using other fragrance, or a chemical method for chemically reacting the malodorous gas can be used to remove or alleviate discomfort. Has been done. However, the adsorption method using activated carbon has a problem that the deodorizing performance deteriorates in a short period of time. The masking method using other fragrances may not be a fundamental solution because the fragrance may cause new discomfort. In a chemical method of changing a malodorous gas by a chemical reaction, for example, by ozone, there is a method of oxidizing and decomposing the malodorous gas, but there is a high risk of causing new harm because excessive ozone is harmful to the human body. That is,
Since it is difficult to control the amount of chemical substances that react with the malodorous gas, unnecessary chemical substances are generated, and it is difficult to make a fundamental solution.

As a technique for solving these problems, the Institute of Fiber Science (Fiber and Industry), Vol. 42, No. 12 (19
86) P18-26 states that a complex compound obtained by reacting a ferrous compound and ascorbic acid in an aqueous solution has a deodorizing power for a nitrogen compound-based odorous gas. However, according to the findings of the present inventors, there is a problem that this complex compound has a weak deodorizing power for sulfur compound-based odor gas, and that this complex compound has a problem that the deodorizing power deteriorates in a relatively short period of time. It was

The inventors of the present invention have disclosed a composition in which a reaction product obtained by contacting a metal such as iron or manganese with ascorbic acid or the like is allowed to coexist with unreacted iron or manganese or the like.
No. 939 (Japanese Patent Application No. 1-2807776). This composition can be manufactured at a low cost, and the deterioration of the air cleaning power is extremely small, and the problems of the prior art were largely solved.

[0005]

DISCLOSURE OF THE INVENTION The present invention aims to provide not only ammonia but also a new air-purified product which improves the desulfurization rate and particularly exhibits a desulfurization performance over a long period of time, and a method for producing the same. It is an issue.

[0006]

The first aspect of the present invention is as follows.
It is an air-purified product characterized in that an iron molded body is used as a carrier and a complex oxide of iron and yttrium is formed on the surface of the carrier.

A second aspect of the present invention is to contact an iron molding with an aqueous yttrium salt solution to cause reaction in the atmosphere,
In the method for producing an air-purified product, the reaction product is heat-treated at 200 ° C. to 350 ° C. in the state of coexisting with unreacted metallic iron.

A third aspect of the present invention is the method for producing an air-purified product according to the second aspect, wherein a basic substance and an iron salt are added to the yttrium salt aqueous solution.

[0009]

According to the research conducted by the present inventors, ammonia (N
H₃) And trimethylamine ((CH ₃)₃N) and other bases
Deodorizing performance of volatile gas is a reaction product of polybasic acid and metal
Adsorbs very well to metal complexes, but hydrogen sulfide (H₂S) Mo
The present inventors have found that one solution to the problem
Is described in Japanese Patent Application No. 63-273195.
This is a method of arranging body bases. However, in subsequent research
Metallic iron is water-soluble for substances that strongly adsorb acidic gases such as hydrogen fluoride
It should be iron hydroxide and ferric oxide formed by dissolving in liquid.
I found out. Furthermore, it effectively produces iron hydroxide,
Metallic iron and hydroxide for stable and long-lasting effect
A state in which iron, ferric oxide, and magnetite coexist is formed.
I also found out that it was necessary to make them. Concrete manufacturing process
In the case of iron, the iron oxide produced near room temperature is heated to 200-300 ° C.
Oxidation by heating to room temperature to decompose and remove some water of crystallization
The specific surface area of iron has been increased, and the hydrogen sulfide adsorption performance has been significantly improved.
I also found that I can do good.

As a result of further improvement studies conducted by the present inventors,
By forming a complex oxide of iron and yttrium on the surface and pores of an iron molded body as a catalyst carrier, a composition having a desulfurization ability superior to that of a composition containing only iron oxide was obtained. .

As the iron molding, 0.1 to 1 of iron is used.
mm processed into particles, fine iron particles with a binder, a paste, etc. mixed and kneaded, and then processed into a sheet or honeycomb shape,
It is possible to use a product obtained by firing and sintering, or a product obtained by applying the above-mentioned kneaded product to a resin porous body and then firing and sintering. The amount of iron-yttrium complex oxide formed on the surface and pores of the iron compact is 0.05 to 0.2.
It is preferably g / g.

[0012] The above-mentioned iron molding is treated with an yttrium salt aqueous solution,
For example, it is brought into contact with an aqueous solution containing yttrium nitrate, yttrium chloride, yttrium sulfate or the like as a main component, and L-ascorbic acid added if necessary. Part of the iron contacted in this yttrium salt aqueous solution is eluted and iron ions coexist. A dipping method is generally adopted as a mode of the above-mentioned contact, but there is no limitation even in the case of spraying, coating or the like as long as the two are sufficiently in contact with each other. The iron molded body is immersed in an aqueous solution of yttrium salt for 30 to 120 seconds, taken out, and then allowed to react in the atmosphere.

On the surface of the iron molding, the reaction product coexists with unreacted metallic iron at 200 ° C.
By heat treatment at up to 350 ° C., the hydroxide formed on the surface of the molded body forms a cluster of iron and yttrium oxide having a size of 1 μm or less.

If the heat treatment temperature is less than 200 ° C., the formation of oxides and the decomposition and removal of water of crystallization become insufficient,
Hydrogen sulfide adsorption performance does not improve so much. On the other hand, when the heat treatment temperature exceeds 350 ° C., the crystal size of the composite oxide becomes large, and the specific surface area of the composite oxide decreases, which causes a decrease in the hydrogen sulfide adsorption surface.

By adding a basic substance such as calcium hydroxide, sodium hydroxide or potassium hydroxide and an iron salt such as iron nitrate, iron chloride or iron sulfide to the aqueous solution of yttrium salt, the hydroxyl group of the aqueous solution of yttrium salt is added. Since it is possible to increase the concentration and allow iron ions to coexist, it is possible to generate a necessary amount of hydroxide in a short time of contact, or to increase the amounts of iron and yttrium composite oxide. The addition amount of the basic substance is preferably such that the yttrium salt aqueous solution is neutralized. The amount of the iron salt added is such that the elution suppression of iron in the yttrium salt aqueous solution is complemented with the addition of the basic substance.

[0016]

[Example] 1 for urethane foam with a coarseness of 20 PPI
A fine iron powder having a thickness of 0 μ was applied and baked at 1150 ° C. for 2 hours in a non-oxidizing atmosphere to produce a porous iron body.
One size is about 90mm x 80mm x 10mm and the weight is about 4
It was 5 g.

The iron porous body was mainly composed of yttrium nitrate and yttrium chloride, and iron salts such as iron nitrate and iron chloride, basic substances such as calcium hydroxide, and catalyst performance activators such as cesium chloride were added. It was immersed in the aqueous solution for 1 minute, taken out, put in a dryer and dried at 120 ° C. for 2 hours. Some of the samples were further heat-treated at 250 ° C. to 350 ° C. for 2 hours and left at room temperature for 4 weeks to avoid the influence of aging, and then the desulfurization performance was evaluated. Typical examples of specific mixing ratios are shown in Table 1, and the pH values of the corresponding aqueous solutions.
Table 2 shows the evaluation results of deodorizing performance.

The desulfurization performance is 4 in a 1 m ³ sealed container.
The deodorization test device having the structure shown in FIG. 1 in which a circulation fan having a blowing capacity of 00 L / min was installed was used for evaluation. That is, the deodorizing filter (air cleaning agent) 3 is set in the holder 7 in the sealed container 1 having the gas inlet 4 and the gas outlet 5, and the circulation fan 2 is provided in the downstream region of the deodorizing filter 3 to supply the gas in the direction of the arrow. It was circulated and the deodorizing filter was installed on the inlet side of the fan to examine the hydrogen sulfide removal performance.

The initial value is set to 10 ppm and after 10 minutes each
The residual concentration after 30 minutes was measured and the removal rate was determined as the deodorization rate. If the residual concentration after 30 minutes cannot be detected by the detector tube, that is, the deodorization rate is 100%, repeat the same test immediately.
After a minute, when the residual concentration was observed, it was judged that the adsorption capacity had been reached, and the weight of the adsorbed hydrogen sulfide up to that point was divided by the weight of the deodorizing filter, and the adsorption weight per unit weight (mg / mg /
g) was determined.

[0020]

[Table 1]

[0021]

[Table 2]

[0022]

[Comparative Example] For comparison, commercially available activated carbon (3 types were prepared,
In Table 3 below, commercial products A, B, and C) are also made of non-woven fabric, and are 100 mm x 80 mm x
40 g of activated carbon was leveled in a 10 mm box to prepare a deodorizing filter, the deodorizing performance was determined, and the results of the deodorizing performance evaluation are shown in Table 3.

[0023]

[Table 3]

[0024]

EFFECTS OF THE INVENTION According to the present invention, a deodorizing filter which is an air-purified product having high desulfurization performance can be manufactured in a simple process.

[Brief description of drawings]

FIG. 1 is a schematic explanatory diagram of a test device for evaluating deodorizing performance.

[Explanation of Codes] 1 ... Airtight container 2 ... Circulation fan 3 ... Deodorizing filter 4 ... Gas inlet 5 ... Gas sample collection port 6 ... Direction of gas circulation

Claims (3)

[Claims] 1. An air-purified product, characterized in that an iron molding is used as a carrier, and a complex oxide of iron and yttrium is formed on the surface of the carrier. 2. A method of contacting an iron molding with an aqueous solution of yttrium salt to cause a reaction in the atmosphere, and heat-treating the reaction product at 200 ° C. to 350 ° C. in the state where the reaction product coexists with unreacted metallic iron. And a method for producing an air-purified product. 3. The method for producing an air-purified product according to claim 2, wherein a basic substance and an iron salt are added to the yttrium salt aqueous solution.