JPH11314020A - Removal material of harmful gas component and its removal method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide capability of removing hydrogen sulfide, mercaptan, etc., of a substance to be oxidizable, and an ionic harmful gas component by a method wherein an ion exchanger is allowed to support a humic substance containing a metallic ion and/or a metallic compound. SOLUTION: A removal agent is prepared by a method wherein after supporting a humic substance by an ion exchanger, it is impregnated with a solution containing a metallic ion and/or metallic compound, dried, or after spraying a humic solution or a dispersion liquid on a support by which the metallic ion and/or the metallic compound are supported, it is dried. Further otherwise, after supporting an aqueous solution containing the humic substance previously by the ion exchanger, it is brought in contact with the aqueous solution containing the metallic ion and/or the metallic compound, and dried. When a shape of the ion exchanger is woven fabric or nonwoven fabric, the fabric thereof is laminated to be formed in a film state, and used by passing air therethrough. Thereby, in addition to gases to be oxidizable of hydrogen sulfied and mercaptans, a high removal effect can be developed to other harmful gas components.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates is, NO _X in the gas phase,
The present invention relates to a removing material for removing harmful gas components such as SO _X , ammonia, amine, hydrogen sulfide, and methyl mercaptan, and a method for removing harmful gas components using the same.

[0002]

2. Description of the Related Art Various means have been conventionally considered for removing harmful gas components in a gas phase. Typical examples thereof include an adsorption method using activated carbon, activated carbon fiber, and zeolite, a combustion method, and a method of oxidative decomposition using an oxidizing agent such as ozone, etc., all of which are widely used on an industrial level or at home. .

[0003] In the precision electronics industry represented by the semiconductor industry, trace gas components on the order of ppb deteriorate the yield of semiconductor products. Began to be used. In particular, ion-exchange fibers have been widely used in recent semiconductor manufacturing plants because of their excellent low concentration gas removal performance, no re-emission of the gas to be adsorbed, and light weight.

[0004] However, each of these conventional techniques has the following disadvantages. In the adsorption method, activated carbon adsorption saturation occurs relatively quickly. On the other hand, when the adsorption is saturated, the gas component once adsorbed is re-emitted, so that it may be a source of harmful gas components. In addition, there is also a problem that it cannot be applied to an existing semiconductor factory because it is heavy and bulky.

[0005] In the case of the combustion described above, a harmful gas component is decomposed by the combustion oxidation, so that a pollutant gas may be generated secondarily. Further, this method can be applied only when a harmful gas is generated on a large scale in a chemical factory or the like. In the method using the oxidizing agent, when an excessive oxidizing agent (for example, ozone) leaks, it has a bad influence on the human body. In particular, when ozone is used as the oxidizing agent, an ozone removing device must be further provided because the ozone content in the exhaust gas is regulated.

Therefore, it is necessary to develop a harmful gas removing means which does not re-release the removed harmful gas, does not involve generation of another harmful gas, and can be used for simple and small-scale treatment. desirable. The inventors of the present invention have specifically focused on malodorous components as materials for removing harmful gas components satisfying the above conditions [materials for removing malodorous components] (JP-A-4-27276).
No. 0) was proposed.

[0007] This proposal is a material for removing malodorous substances in which humic substances (humic acid) containing copper ions or copper compounds are carried on a fibrous substance such as cloth, especially when the object to be removed is an oxidizable substance. It is effective. However, this removal material also has the following problems, and cannot exhibit stable performance. That is, when humic acid is supported on a fibrous substance (especially a long nonwoven fabric), the humic acid cannot be uniformly supported, and the removal performance of harmful gas components is not stable. The removal performance for ionic harmful gas components other than mercaptan and the like is not sufficient.

[0008]

DISCLOSURE OF THE INVENTION The present invention can uniformly support humic substances such as humic acid, and is stable against oxidizing substances such as hydrogen sulfide and methyl mercaptan, as well as ionic harmful gas components. It is an object of the present invention to provide a removing material having improved removing performance and a removing method using the same.

[0009]

The present invention has the following arrangement. 1. A material for removing harmful gas components, wherein a humus containing a metal ion and / or a metal compound is carried on an ion exchanger. 2. 2. The material for removing harmful gas components according to the above item 1, wherein the metal ion and / or metal compound is a copper ion and / or a copper compound.

[0010] 3. 3. The material for removing harmful gas components according to 1 or 2, wherein humic acid is used as the humus. 4. 4. The material for removing harmful gas components according to any one of the above items 1 to 3, wherein the ion exchanger is in the form of a woven or nonwoven fabric which is a fiber or an aggregate thereof. 5. The material for removing a harmful gas component according to any one of the above items 1 to 4, wherein the ion exchanger is produced using a radiation graft polymerization method.

6. The harmful gas component removing material according to any one of the above items 1 to 5, wherein the ion exchanger is an anion exchanger. 7. 7. A method for removing harmful gas components in air, comprising bringing air into contact with both the material for removing harmful gas components according to any one of 1 to 6 and an ion exchanger not carrying humus. .

8. 8. The method for removing harmful gas components according to the item 7, wherein the ion exchanger not carrying humus is in the form of a woven or nonwoven fabric which is a fiber or an aggregate thereof. 9. 9. The method for removing a harmful gas component according to the above item 7 or 8, wherein the ion exchanger not supporting the humus is produced by using a radiation graft polymerization method.

10. A woven or nonwoven fabric comprising the ion-exchange fiber carrying the humus according to any one of the above items 1 to 6, and an ion-exchange fiber not carrying the humus according to any one of the above items 7 to 9. A method for removing harmful gas components, wherein air is passed through a filter on which a woven or nonwoven fabric is laminated. The present invention, by adopting the above configuration, can uniformly support humic substances such as humic acid, stabilize not only odorous components, but also harmful gas components, and reduce hydrogen sulfide as an oxidizable substance. And a method for removing harmful gas components using the same, which can exhibit sufficient removal performance for ionic harmful gas components other than methane and methyl mercaptan.

In the present invention, humus containing a metal ion and / or a metal compound is effective against oxidizable malodorous substances such as hydrogen sulfide and mercaptans, and also against ammonia and amines. Shows high removal effect. In particular, when the metal ion and / or the metal compound is copper ion and / or
Alternatively, when the compound is a copper compound, a remarkable removal effect is exhibited, and the effect is stably maintained for a long time. Such an effect is as described in Japanese Patent Application Laid-Open No. Hei 4-272760, which discloses that the humus containing a metal ion and / or a metal compound is supported on an ion exchanger. It is clear that the effect of is not suggested at all from the following description.

As the humus used in the present invention, any humus which belongs to the humus defined as brown or black amorphous organic matter in soil or coal can be used. , Fulvic acid and the like are used, and among them, humic acid is preferably used. Also,
As long as fine particles and a trace amount of gas are not generated, the humus obtained naturally may be used without being separated.

The present invention uses an ion exchanger as a carrier for supporting this substance. The ion exchange group is a typical hydrophilic group, and when the humus of the present invention is dissolved in water and supported on an ion exchanger, the humus is well compatible with the carrier and can be provided uniformly. JP-A-4-272760
In the publication, activated carbon, zeolite, porous ceramics and the like can be used as the carrier, as long as they are generally used as the carrier. However, fibrous substances such as cloth and gauze have a large surface area and a large adsorption speed. It is preferred.

In the present invention, since the same effect can be expected, a fibrous ion exchanger is preferable as the shape of the ion exchanger. In particular, the shape of a woven or non-woven fabric, which is an aggregate of fibers, is preferred because of its good workability into a filter or the like. Humus contains a large amount of carboxyl groups in its structure and behaves as an anion. Therefore, the ion exchanger as a carrier has a quaternary ammonium group, a tertiary amino group, or the like as its ion exchange group. Anion exchangers are preferred from the standpoint of humus loading speed and uniformity.

Another advantage of using an ion exchanger as a carrier is that the function of removing gas from humus containing metal ions and / or metal compounds and the function of removing gas inherent to the ion exchanger are combined. What you can do. Humus is effective in removing oxidizable gases such as hydrogen sulfide and mercaptans, but the mechanism of its removal is not yet fully understood. However, when metal ions and / or metal compounds are included in the humus, they function as oxidation catalysts, and the oxidizable gas undergoes decomposition by oxygen in the air to change its chemical form. Is estimated to be removed by In Japanese Patent Application Laid-Open No. 4-272760, the purpose was to remove the bad odor, and this was sufficiently effective.
For semiconductor factories, it is necessary to reliably remove substances whose chemical form has changed and not to re-emit them. Normally, trace amounts of harmful gas components existing in the air and affecting the yield of semiconductors are often converted into ionic gases by oxidation. A harmful gas component removing material in which an ion exchanger carries humus containing a metal ion and / or a metal compound can effectively remove the ionic gas.

In order to carry out this complexing, it is necessary to keep the ion exchange capacity of the ion exchanger as a carrier sufficiently regenerative. Since the humus containing a metal ion and / or a metal compound exerts a catalytic function in a very small amount, the amount to be supported may be a small amount, and the consumption of the ion exchange capacity may be small.
Known ion exchangers can be used as the carrier. Among them, an ion exchanger produced using a radiation graft polymerization method is most suitable. This manufacturing method can be applied to various types of ion-exchanger base materials, and when the present invention is carried out, there is a track record in the most frequently used nonwoven fabric.

The ion exchanger obtained by the radiation graft polymerization method has a high adsorption rate because the graft chains are not crosslinked. For this reason, in addition to the advantage that the humus is carried at a high speed, the harmful gas component that has changed its chemical form by contact with the humus is instantaneously captured. The best method. When humus is carried on the cation exchanger as an ion exchanger, both the oxidizable gas and the basic gas such as ammonia and amine are removed. In this case, examples of the exchange group include a sulfonic acid and a carboxyl group.

When an anion exchanger is selected as an ion exchanger and a humus is carried on it, an oxidizable gas, an acidic gas such as hydrogen chloride or an organic acid, and a small amount of ammonia and amines can be removed. . Here, it is presumed that removal of ammonia and amines is trapped by forming a complex bond with a metal ion and / or a metal compound.

As the carrier resin for the ion exchanger, known resins are used, and graft copolymers of polyolefins such as polyethylene and polypropylene are preferred. Examples of the graft chains include polymer chains of glycidyl methacrylate (GMA), acrylic acid, styrene, and the like. GMA and styrene can be introduced with an ion exchange group by a known method after the graft polymerization.

As means for preparing the removing material of the present invention,
Although not particularly limited, for example, a method in which a humus is supported on an ion exchanger and then impregnated with a solution containing a metal ion and / or a metal compound and then dried, A method of spraying a humus solution or dispersion onto the supported carrier, followed by drying. An aqueous solution containing humus is previously supported on the carrier, and then contacted with an aqueous solution containing metal ions and / or a metal compound, followed by drying. Any method such as a method can be adopted.

A method in which an ion exchanger carrying humus and an ion exchanger not carrying humus are combined, and a gas component that cannot be sufficiently removed by the former or a gas component whose chemical form has been changed is removed by the latter, or a method of removing the gas component. The opposite can also be adopted. In this case, if the shape of the ion exchanger is a woven fabric or a nonwoven fabric, a method of laminating these fabrics, forming a filter shape, and passing air is simple. In this case, the lamination method can be arbitrarily changed according to the type of the harmful gas component to be removed, and whether the humus is carried or not, whether the ion exchanger is an anion, etc. The order can be combined, and the number of layers can be arbitrarily adjusted.

The amount of humus containing a metal ion and / or a metal compound, the type and shape of an ion exchanger as a carrier, and the type and shape of an ion exchanger containing no humus are determined by the harmful gas components. It can be appropriately selected depending on the environment in which the removing material is used, required performance, and the like. The ion exchanger not carrying humus is also preferably produced by the above-mentioned radiation graft polymerization method.

As the metal compound used in the present invention, it is preferable to use an inorganic acid salt or an organic acid salt which is soluble in water and easily dissociates and releases ions when dissolved. Such salts include, for example, sulfates, nitrates, or oxalates.

Although the amount of metal ions and / or metal compounds used for humus can be very small, it is effective. However, the effective range is as follows. As usual, 0.000
It is 2 to 0.01 parts by weight. An excessive amount of the metal does not lower the performance of the product of the present invention, but increases the cost and is therefore not preferred.

[0028]

The present invention will be specifically described below with reference to examples. However, the present invention is not limited to only these examples. Example 1 (Preparation of Removal Material) A nonwoven fabric made of polyethylene (sheath) / polypropylene (core) composite fiber having a basis weight of 50 g / m ² was irradiated with gamma rays at 100 kGy in a nitrogen atmosphere. Next, the nonwoven fabric was immersed in a glycidyl methacrylate solution, and reacted at 50 ° C. for 4 hours under reduced pressure. The nonwoven fabric after the reaction is immersed in a dimethylformamide solution,
After washing at 0 ° C. for 12 hours, drying was performed and the weight was measured. When the graft ratio was calculated from the weight change before and after the reaction,
132%.

Next, the grafted nonwoven fabric was immersed in a 20% aqueous solution of diethanolamine and reacted at 80 ° C. for 4 hours to carry out amination. After washing with pure water, the ion exchange capacity was measured. As a result, a weakly basic anion exchange nonwoven fabric having a tertiary amino group of 2.81 meq / g was produced.
The weight of the product was 164 g / m ² .

About 2 g of this weakly basic anion exchange nonwoven fabric
Was cut out, immersed in an aqueous copper-containing humus solution shown in Table 1, and then dried. At this time, all of the humus solutions could be uniformly applied to the weakly basic anion exchange nonwoven fabric. (Removal Test for Hydrogen Sulfide) (1) Removal Performance Test The removal material samples (Sample Nos. 1 to 8) described in Table 1 were punched into 25 mmφ, and one glass column having an inner diameter of 25 mmφ was filled. Hydrogen sulfide removal by a system that mixes the air from the dry air cylinder with hydrogen sulfide in the permeator and the air route from the pump using a mixer attached to the filter mounting part of the flow test device shown in Fig. 1. A performance test was performed. The concentration of hydrogen sulfide at the filter inlet was set to 0.1 ppm, the flow rate was set to 0.5 liter / min, the treatment was performed for 120 minutes, and the concentration of hydrogen sulfide at the filter outlet was measured. The results are shown in Table 1.

[0031]

[Table 1]

Table 1 shows that the samples of the present invention (Nos.
o. It is clear that the removal performance of 5) for hydrogen sulfide is high. On the other hand, in the comparative examples (No. 6 to No. 8), the removal performance was extremely small. (Example 2) Following the removal material sample used in Example 1, 0.2 ppm of hydrogen chloride was passed, and the concentration of hydrogen chloride at the outlet side was measured. 1 to No. Each of the samples No. 8 was 0.02 ppm or less. That is, No. 1
-No. It is clear that the sample No. 5 prepared according to the present invention can remove not only hydrogen sulfide but also hydrogen chloride.

[0033]

According to the present invention, hydrogen sulfide and mercaptans can be obtained by supporting a humus, which is an inexpensive and nontoxic natural organic substance, with an extremely small amount of metal ions and / or metal compounds added to an ion exchanger. It is intended to provide a low-cost material for removing harmful gas components which exhibits an extremely high removal effect on other harmful gas components in addition to the oxidizable gas and has a long lasting effect.

The removal material of the present invention can further enhance the above-mentioned effects by being used in combination with a normal ion exchanger, and can be used for a filter for removing a trace amount of harmful gas components in a semiconductor factory or the like. It is. And since the removal material has a long lasting effect, it can be operated for a long time, eliminating the need for replacing the filter unit.
The running cost is also low.

[Brief description of the drawings]

FIG. 1 is a diagram showing a distribution test device.

Continued on the front page (72) Inventor Hideaki Sekiguchi 11-1 Haneda Asahimachi, Ota-ku, Tokyo Inside Ebara Corporation

Claims (10)

[Claims] 1. A material for removing harmful gas components, wherein a humus containing a metal ion and / or a metal compound is carried on an ion exchanger. 2. The material for removing harmful gas components according to claim 1, wherein said metal ions and / or metal compounds are copper ions and / or copper compounds. 3. The material for removing harmful gas components according to claim 1, wherein humic acid is used as said humus. 4. The method according to claim 1, wherein the ion exchanger is a woven or non-woven fabric which is a fiber or an aggregate thereof.
4. The material for removing harmful gas components according to any one of claims 3 to 3. 5. The material for removing harmful gas components according to claim 1, wherein the ion exchanger is produced by using a radiation graft polymerization method. 6. The material for removing harmful gas components according to claim 1, wherein the ion exchanger is an anion exchanger. 7. A method for removing harmful gas components according to any one of claims 1 to 6 and contacting air with both an ion exchanger not carrying humus. How to remove harmful gas components. 8. The method for removing harmful gas components according to claim 7, wherein the ion exchanger not carrying humus is in the form of a woven or nonwoven fabric which is a fiber or an aggregate thereof. 9. The method for removing harmful gas components according to claim 7, wherein the ion exchanger that does not support humus is produced by using a radiation graft polymerization method. 10. A woven or nonwoven fabric comprising the ion exchange fiber carrying the humus according to any one of claims 1 to 6, and the humus according to any one of claims 7 to 9. A method for removing harmful gas components, comprising passing air through a filter on which a woven or nonwoven fabric made of ion-exchange fibers not supported is laminated.