JPH05228333A - Method for oxidizing gas containing reducing gas and device therefor - Google Patents

Abstract

PURPOSE:To oxidize and decompose a malodorous gas contg. an org. reducing gas such as gaseous acetaldehyde and formaldehyde and to make the gas harmless. CONSTITUTION:A gas contg. reducing gases is brought into contact with an gas-passable metallic porous body 2 impregnated with aq. hydrogen peroxide 3 to oxidize the reducing gases. Besides, the porous body 2 is filled in a gas passage in a reaction vessel 1, and the aq. hydrogen peroxide 3 is intermittently or continuously supplied.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a treatment method and an apparatus therefor for oxidizing and decomposing a malodorous gas containing an organic reducing gas such as aldehyde gas such as acetaldehyde and formaldehyde.

[0002]

2. Description of the Related Art Regarding a gas containing a reducing gas, from the viewpoint of danger and environmental hygiene, various working environment standards,
Hygiene standards have been established, and simple processing technology for gases containing these is required. As a general treatment method for a gas containing such a reducing gas, there is an activated carbon adsorption method, but the adsorption capacity of activated carbon is small, the adsorbed reducing gas is re-released when the temperature rises, When used in the environment, there are many difficulties in use, such as activated carbon being ignited.

As another treatment method, there is a combustion oxidation method using a catalyst, but this method requires a large amount of equipment and uses a fuel for the combustion oxidation, so that not only the running cost becomes high but also CO _{2 is} always generated. Since NO _{x and the} like are emitted to the exhaust side, it is not preferable from the global environment.

[0004]

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a processing method and apparatus capable of exhibiting the processing effect of reducing gas for a long period of time, and being safe and having a low running cost. It is an issue.

[0005]

Means for Solving the Problems The present invention is to solve the above problems and is a porous metal gas permeable porous body comprising at least one of Fe and Mn impregnated with a hydrogen peroxide solution containing a reducing gas-containing gas. Is a method for oxidizing a reducing gas-containing gas, wherein the reducing gas is oxidized by contacting the reducing gas.

Further, Fe, Mn are provided in the gas passage in the reaction tank.
Of the porous metal gas permeable porous body, and the porous metal gas permeable porous body is provided with a water supply device for intermittently or continuously supplying hydrogen peroxide solution. It is an apparatus for oxidizing a gas containing gas.

[0007]

The present invention treats a reducing gas-containing gas with a porous metal gas permeable porous body composed of at least one of Fe and Mn and hydrogen peroxide solution, so that the reducing gas can be efficiently reduced at room temperature with a simple apparatus. A method and an apparatus for oxidatively decomposing gas into harmless one. We have F
A porous metal gas permeable porous body (hereinafter referred to as a porous body) composed of e or / and Mn is impregnated with hydrogen peroxide solution, and then a reducing gas-containing gas (hereinafter referred to as a gas) is passed through the porous body. And found that reducing gas is extremely effectively detoxified by oxidation. An example is shown below.

A gas (1 m ³ ) containing 360 ppm of formaldehyde was sealed in a container, and 4% concentration of H ₂ O ₂ was added.
A sintered porous body of iron impregnated with (2 g) was installed, and a gas was circulated in the porous body at a circulation rate of 0.4 m ³ / min, and formaldehyde was completely oxidized and removed after 30 minutes. The effect of extremely efficiently reducing gas in this manner is removed, the inside very porous sintered steel porous microscopically as shown the microstructure of an enlarged 100 times in FIG. 2 H ₂ O ₂ Water permeates the entire porous body,
The present inventor believes that the oxidizing reaction occurs efficiently because the reducing gas is oxidized by the Fenton reaction of the equations (1) to (3) on the surface of the sintered iron throughout the porous body. The iron-made sintered porous body used in the above experiment is a polyurethane foam (urethane foam) coated with iron powder and then sintered to eliminate the urethane foam.
In FIG. 2, 11 is a pore part of urethane foam before sintering, 12 is sintered iron, 13 is a micropore inside the sintered iron, and 14 is a hole generated by burning of the urethane foam.

Fe + H ₂ O ₂ → Fe ⁺⁺ + 2OH ⁻ (Metallic iron is ionized) (1) Fe ⁺⁺ + H ₂ O ₂ → Fe ⁺⁺⁺ + OH ⁻ + -OH (radical generation)・ ・ (2) HCHO + 2-OH → HCOOH + H ₂ O (Fenton oxidation reaction) ・ ・ (3)

The HCOOH produced thereafter reacts with metallic iron to be converted into a stable and harmless iron salt. The porous metal gas permeable porous body composed of Fe or / and Mn used in the present invention contains Fe or / and Mn as a main component and Cu,
It may contain a metal such as Cr, Ni, Sn, or Zn that improves the touch resistance. As the shape of the porous body, a metal powder coated on an organic polymer porous body such as urethane foam,
Alternatively, it may be one obtained by sintering it in a non-oxidizing atmosphere, one obtained by molding a metal powder into a spherical shape or a cylindrical shape, or one obtained by laminating those obtained by sintering it. Among them, the sintered metal porous body is the most preferable as the porous body of the present invention in that H ₂ O ₂ water is impregnated into the porous body.

Regarding the concentration of H ₂ O ₂ water, 1% to 10% concentration (weight ratio) is generally sufficient although it depends on the concentration and amount of reducing gas to be treated. If the concentration is too low, the impregnation needs to be repeated many times, which is complicated, while if the concentration is too high, unreacted H ₂ O ₂ is vaporized, which is uneconomical and unnecessarily oxidizes the metal.

Next, the processing apparatus of the present invention will be described.
This apparatus is an oxidation treatment of a reducing gas-containing gas in which a reducing gas-containing gas is passed through a porous metal permeable porous body part made of Fe or and Mn that supplies hydrogen peroxide water intermittently or continuously. It is a device.

A conceptual view of this apparatus is shown in FIG. 2, in which a porous body 2 is installed in a reaction tank (reducing gas oxidative decomposition tank) 1 and H
₂ O ₂ water 3 spray nozzle 4 spray nozzle 5
Intermittently or continuously supplied to the porous body via
The porous body is impregnated with H ₂ O ₂ water to enable the Fenton oxidation reaction with the gas introduced by the blower fan 7. 6 is H ₂ O ₂ water dropped after impregnation
_A circulation pump for returning to the ₂ O ₂ adjusting tank, 7 is a blowing fan for introducing gas into the reaction tank, 8 is a tank for adjusting the H ₂ O ₂ concentration, and 9 is a tank for adding H ₂ O ₂ .

The gas introduced by the blower fan may contain oils and fats in the case of exhaust gas treatment such as baking coating, and the oils and fats adhere to the surface of the porous body to interfere with the reactivity. It goes without saying that a device for removing fats and oils by a filter or washing with water is installed.

[0015]

[Example] Pigment iron powder having an average particle size of 10μ was applied to urethane foam using polyvinyl alcohol as a binder, and then 1
Make an iron-based sintered porous body that is sintered at 200 ℃,
The filter was 4 cm × 4 cm × 2 cm (weight: 30
g). After impregnating the filter with 6 g of 4% H ₂ O ₂ water, the filter was installed in the experimental apparatus shown in FIG. 3 and a gas containing 30 ppm of formaldehyde was passed at a flow rate of 4 l / min. Was removed for a long time as shown in Table 1. In FIG. 3, 2 is a porous body, 21 is a gas cylinder, 22 is a flow meter, and 23 and 24 are pipes for measuring concentration on the inlet side and the outlet side, respectively. Second after this experiment
As a cycle test, the filter was again impregnated with 6 g of 4% H ₂ O ₂ water and the same test was conducted. As shown in Table 1, formaldehyde was completely removed as in the previous test.

[0016]

[Table 1]

[0017]

EFFECTS OF THE INVENTION According to the present invention, a reducing gas can be rapidly and simply oxidatively decomposed at room temperature by impregnating a porous metal porous body composed of Fe and / or Mn with hydrogen peroxide.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of an apparatus of the present invention.

FIG. 2 is a diagram showing a microstructure of a sintered iron-made porous body according to the present invention.

[Figure 3] Conceptual diagram of the experimental equipment

[Explanation of symbols]

 1 Reaction Tank 2 Porous Metal Porous Body 3 Hydrogen Peroxide Water 5 Spray Nozzle

Claims (2)

[Claims] 1. The reducing gas is oxidized by bringing the reducing gas-containing gas into contact with a porous metal gas permeable porous body made of at least one of Fe and Mn impregnated with hydrogen peroxide solution. A method for oxidizing a gas containing a reducing gas. 2. A gas passage in a reaction vessel is loaded with a porous metal permeable porous body made of at least one of Fe and Mn, and the porous metal permeable porous body is intermittently supplied with a hydrogen peroxide solution. An oxidizing treatment apparatus for a reducing gas-containing gas, comprising a water supply device for continuously supplying.