JPH02284648A - Activated catalyst for deodorizing ozone - Google Patents

Abstract

PURPOSE:To obtain the catalyst which has high performance and also continuously stabilized performance by carrying one or more kinds of metallic oxides on the carbonaceous material and treating the obtained ozone deodorizing catalyst by a reductive soln. and thereafter drying it. CONSTITUTION:In a catalyst producing stage 1, both the starting raw material M1 of a catalytic activator made of one or more kinds of oxides of metals such as vanadium, chromium and manganese and a catalytic carrier M2 such as activated carbon and graphite are molded by an impregnating method and a kneading method. Thereafter the molded body is dried and calcined. Then in a reducing stage 2, the molded body is immersed in a reducing agent soln. M3 such as a formaldehyde aq. soln. and reducing treatment operation is performed while sufficiently agitating the same. Furthermore in a drying stage 3, the vacuum drying operation is performed to separate the reducing agent M3 remaining in the pores of the catalyst and a product M4 is obtained. Therein the ozone decomposing effect is enhanced with increase in the reducing agent concn. Thereby high activation of the catalyst is enabled.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an activated ozone deodorizing catalyst, particularly an activated ozone deodorizing catalyst suitable for use in ozone deodorizing of odors generated from sewage, human waste, and garbage incineration facilities. Regarding ozone deodorizing catalyst.

[Conventional technology]

An ozone deodorization (offensive odor removal) method has already been proposed in which odor components are oxidized and decomposed by ozone in the gas phase. One of the features is that a plurality of catalyst layers each carrying a metal oxide are arranged in series, and an ozone injection means is provided in front of each layer.

The catalyst used in this proposed method is, for example, a catalyst carrier made of granular, crushed or powdered activated carbon, gutphite, carbon fiber, etc. metal oxide 1
If necessary, platinum, barodium, rhodium, ruthenium, etc. are supported together with the metal oxide as a co-catalyst.

Although not mentioned in this proposed method, in order to produce the above catalyst, it is necessary to mold the catalytically active metal oxide and the carrier, dry it, and then sinter it under reducing atmosphere conditions, which allows continuous production of the highly active catalyst. However, it was not easy to produce it stably.

[Problem to be solved by the invention]

In view of the above-mentioned state of the art, the present invention aims to provide an ozone deodorizing catalyst which is more active than conventional ozone deodorizing catalysts and has continuously stable performance.

[Means to solve the problem]

The present invention is an activated ozone deodorizing catalyst, which is obtained by treating an ozone deodorizing catalyst in which one or more metal oxides are supported on a carbonaceous material with a reducing solution and then drying the catalyst.

The ozone deodorizing catalyst in which one or more metal oxides are supported on a carbonaceous material as used in the present invention refers to an ozone deodorizing catalyst in which one or more metal oxides are supported on a carbonaceous material, and an ozone deodorizing catalyst in which one or more metal oxides are supported on a carbonaceous material is a
One or more metal oxides such as vanadium, chromium, manganese, iron, Koba/I/L, nickel, copper, silver, and zinc are supported as active ingredients, and if necessary, platinum,
It refers to a product obtained by molding, drying, and calcining a product in which badge rhum, rhodium, ruthenium fr, and to are supported together with the metal oxides mentioned above as cocatalysts.

The catalyst of the present invention is obtained by treating the above-mentioned known ozone deodorizing catalyst with a reducing solution and then drying it. The reducing solution is a formala/l/dahyde aqueous solution, a low boiling point aldehyde aqueous solution such as acetaldehyde, hydroxylamine, ascobic acid, etc. A water-soluble reducing agent is used. Drying after the reducing solution treatment is carried out at -100-180'C inside the shell to prevent oxidation.
.

Preferably it is carried out at 105=150°C! ,I-
In addition, it is preferable to carry out the reaction under reduced pressure in order to remove the reducing solution remaining in the catalyst pores.

[Effect]

By treating the catalyst in which one or more of the metal oxides described above supported on a carbonaceous material with a reducing solution, the metal oxide supported on the catalyst carrier is partially reduced, and the catalyst in such a state has a bad odor. Acts as an effective catalyst in ozone deodorization methods that oxidize and decompose components.

Hereinafter, an outline of a manufacturing example of the activated ozone deodorizing catalyst of the present invention will be explained with reference to FIG. In FIG. 1, M is a starting material for a metal oxide that becomes a catalyst active body, M is a catalyst carrier,
M is the reducing agent solution, pigeon is the product, 1 is the conventional catalyst manufacturing process,
2 indicates a reduction treatment step, and 3 indicates a drying step.

After molding the catalyst active starting material M and the catalyst carrier M by an impregnation method or a kneading method (the molding is performed in a pellet shape, a honeycomb shape,
After passing through the conventional catalyst production step 1 of drying and firing (either in the form of fiber cloth), it is subjected to reduction treatment in the reduction step 2. Here, the above catalyst manufacturing step 1 is added to a solution containing a reducing agent.
The catalyst is immersed and thoroughly stirred to carry out the reduction treatment. As the reducing agent, for example,
Mua μ / Dehyde aqueous solution, low boiling point a of acetaldehyde /
Water-soluble reducing agents such as l/dehydes, hydroxyamines, ascobic acid, etc. are particularly preferable, and the concentration of the reducing agent is (11 to 10 wt%, preferably 0.5 to 5 wt%).
%, preferably 1 to 5 times (N amount), preferably 1 to 3 times the weight of the catalyst. The solution temperature may be at room temperature, but it can be raised to 50 to 40°C to enhance the effect. However, care must be taken in this case as evaporation of the reducing agent may occur. The immersion time will be adjusted as appropriate depending on the state of the reduction treatment of the metal oxide, but is approximately 1 to 10 hours.

Next, the reduced catalyst is dried in an atmosphere of 100-180'C%, preferably 105-150C. Drying under reduced pressure is also preferred in order to accelerate drying and quickly remove the reducing agent remaining in the catalyst pores.

FIG. 2 shows an example of the effect when an aqueous formalin solution is mixed with a reducing agent. The catalyst uses granular coconut shell activated carbon as a carrier, and supports 1. It is something that As the reducing agent concentration increases, the ozone decomposition effect (proportional to the deodorizing effect) increases. 1 [Example] A catalyst in which 4 wt % of cobalt oxide was supported on coconut activated carbon (4 to 6 φX 4 to 10 cod I) was
After being immersed in a wt% formalin aqueous solution for about 2 hours, it was taken out, drained, and dried under reduced pressure at 130°C in a trench to eliminate moisture and formalin odor.

Thereafter, air containing an ozone concentration of 10 ppm was introduced into the air [38si! The ozone concentration at the outlet was measured by passing the mixture through the filled reaction tube under the condition of S■=I(-1 toooo), and the ozone decomposition rate was determined.

As a result, the ozone decomposition rate was 9995%. In contrast, the ozone decomposition rate of the catalyst without reduction treatment was 99.8.
5%, and a difference was observed between the two.

Although the above example used gobalt oxide as the active component, similar results were obtained with other metal oxides listed as the active catalyst component.

〔Effect of the invention〕

By treating a catalyst in which a metal oxide is supported on a catalyst carrier with a reducing solution, the catalyst can be highly activated, making it an effective catalyst in the ozone deodorization method that oxidizes and decomposes odor components. I was able to do this.

[Brief explanation of drawings]

FIG. 1 is a process diagram of an example of manufacturing the activated ozone deodorizing catalyst of the present invention, and FIG. 2 is a chart showing the effect of treating the catalyst of the present invention with a reducing solution.

Claims (1)

[Claims] An activated ozone deodorizing catalyst characterized in that it is obtained by treating an ozone deodorizing catalyst comprising one or more metal oxides supported on a carbonaceous material with a reducing solution and then drying the catalyst.