JPH0624608B2 - Ozone decomposer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to an ozone decomposing agent.

<Prior art> Ozone has nascent oxygen and is the gas with the oxidative power second only to fluorine. Therefore, by utilizing its oxidative power, water treatment, decomposition and deodorization of malodorous components, and oxidation in the chemical industry. It is increasingly used as an agent. In addition, the generation of ozone due to silent discharge can be recognized from a device incorporating a high voltage generator such as a copying machine.

On the other hand, ozone is regulated to 0.06ppm or less as a work environment allowable concentration from the viewpoint of preventing air pollution, and sufficient removal treatment is required. As a conventional technique for these treatments, as described in JP-A-59-42022, (1)
There are a thermal decomposition method, (2) chemical cleaning method, (3) activated carbon method and the like.

(1) The thermal decomposition method makes use of the property that ozone rapidly decomposes at high temperatures, but has the drawback that the processing cost is high because the gas containing ozone must be processed at high temperatures.

(2) The chemical cleaning method is a method in which ozone is treated with a reducing aqueous solution by utilizing the chemical nature of ozone, which has a strong oxidizing power, but the cost of chemicals such as sodium thiosulfate used as a reducing agent is high. Moreover, there is a problem that the waste liquid needs to be treated.

(3) The activated carbon method uses the oxidizing power of ozone gas in the activated carbon layer to chemically change the carbon of activated carbon into carbon dioxide gas to remove ozone, or to directly decompose ozone by catalytic decomposition on the surface of activated carbon. Although it is a method of decomposing and removing it, there is a danger of explosion because high concentration ozone reacts violently with activated carbon. Further, in the presence of water, there is a problem that the decomposition rate of ozone at low temperatures is greatly reduced.

<Problems to be Solved by the Invention> The activated carbon method is a method that has already been put into practical use because it is inexpensive in cost. For example, JP-A-49-123187
Discloses a mixture of activated carbon and silica-alumina gel. However, its life span is short and does not meet the market demand. Also, in Japanese Patent Laid-Open No. 57-77019, M
A catalyst in which oxides such as n, V 2, Fe, Cu, Ni, Cr, Co, and Zn and salts thereof are supported on activated carbon, and a catalyst in which Pd, Pt, and Ag are supported on activated carbon are disclosed. However, it has been confirmed that these ozones have a low decomposition rate and a short life. Further, JP-A-59-42025 shows the temperature dependence when decomposing with an iron-based ozone decomposing agent. That is, 99.999% at 50 ° C, 55.9% at 30 ° C, 4.
It is described that the decomposition rate of ozone decreases remarkably as the temperature decreases to 2%.

As described above, the ozone decomposing activity is greatly reduced at low temperatures and / or in the presence of water. On the other hand, as a condition for generating and using ozone gas, it is generated at a low temperature in order to utilize the characteristics of ozone, and when the ozone gas is used, it is often used under high humidity conditions containing a large amount of water.

The present invention, when decomposing and removing ozone contained in gas components, has high activity even under low temperature and high humidity conditions,
It is intended to provide a long-life ozone decomposing agent.

<Means for Solving the Problems> The present inventors have reached the present invention as a result of various studies on ozone decomposing agents in order to solve the above problems.
That is, the present invention is barium peroxide, calcium peroxide,
The present invention relates to an ozone decomposer containing at least one selected from zinc peroxide, sodium percarbonate and sodium perborate.

The ozone decomposing agent of the present invention is
The ozone has a remarkably high resolution, maintains high activity even at low temperature and high humidity, and can easily decompose ozone.

The present invention will be described in detail below.

In the present invention, one or more compounds selected from barium peroxide, calcium peroxide, zinc peroxide, sodium percarbonate and sodium perborate are used as the ozone decomposer.

In order to improve the performance, the ozone decomposing agent of the present invention preferably contains a commonly used porous carrier. Preferred carriers include silica, alumina, silica-alumina, silica-magnesia, natural zeolite, synthetic zeolite, diatomaceous earth, activated carbon, Kanuma soil, clay minerals, and inorganic fibers, but are not particularly limited to these. However, any commonly used carrier can be used. Among them, activated carbon is particularly preferable. When activated carbon is used as the carrier, the ozone decomposing activity becomes high and it becomes possible to use it at a lower temperature. Considering practical aspects such as the strength of the molded product of the ozone decomposing agent and the risk of explosion, it is more preferable to use activated carbon alone as a carrier together with other carriers. When a carrier is used, the proportion of the carrier in the ozone decomposer is arbitrary, but preferably 1 to
99% by weight is particularly preferred, 30 to 95% by weight. When activated carbon is used together with other carriers, the proportion of activated carbon in the carrier is preferably 5 to 90% by weight, particularly preferably 10 to 70% by weight.

The ozonolysis agent of the present invention is often obtained as a powder depending on the form of the raw material used, and may be used as it is in a powder state, but if there is a restriction on use, it may vary depending on the size of solid particles. It can also be used by molding into various forms such as granules having a diameter of about 1 mm and pelletized granules having a diameter of about 2 mm to 20 mm. Generally, when powder is molded into pellets or the like, a binder (binder) is often used to facilitate molding, but the ozone decomposing agent of the present invention is not an exception, and a binder that is usually used is used. It is possible to mold. Bentonite as a preferred binder,
Inorganic substances such as colloidal silica, white clay, kaolin, water glass, etc. or sodium alginate, glue, glucose, dextrin, hydroxypropyl cellulose (HP
C), carboxymethyl cellulose sodium salt (CMC),
Polyvinyl alcohol (PVA), polyvinylpyrrolidinone
(PVP) and other organic polymer binders,
The binder is not limited to these, and any commonly used binder can be used. Further, in addition to this, it is also possible to form a honeycomb shape, or it is possible to use by using an ozone decomposing agent supported on a filamentous plastic molded article,
There is no restriction on how to use these.

The raw material used for producing the ozone decomposer of the present invention is not particularly limited, and any commonly available raw material can be used.

The temperature at which the ozone decomposing agent of the present invention is used is not particularly limited, and the ozone decomposing agent can be used in a wide temperature range of -10 ° C to 150 ° C. In particular, it can be used at a low temperature of 0 ° C to 50 ° C.

<Examples> Examples will be described below, but the present invention is not limited to these examples.

Example 1 200 g of 50% calcium peroxide, 1000 g of synthetic zeolite and 100 g of carboxymethyl cellulose sodium salt as a binder were mixed with a small amount of water, and a pore size was 4 mm by an extrusion molding machine.
It was extruded from the die. The extruded udon-like ozonolysis agent was immediately cut into a length of 3 to 10 mm with a cutter and dried at 110 ° C. to obtain a cylindrical ozonolysis agent. 1000 ml (780 g) of the obtained ozone decomposer was filled in a stainless steel pipe (inner diameter 55 mm) and kept at 50 ° C. The ozone decomposing agent is preliminarily adjusted to an ozone concentration of about 850 ppm with ozone-containing air at a flow rate of 5 liters per minute through a water seal to be humidified, and then communicated with the ozone decomposing agent, and its outlet gas is ozone. It guided to the monitor and detected the ozone concentration. The data of the main breakthrough times are shown in Table 1.

Example 2 200 g of 80% barium peroxide, 1000 g of silica aerosil and an acrylic polymer emulsion as a binder (solid content
An ozone decomposer was obtained in the same manner as in Example 1 using 200 g (containing 50%). A test was conducted in the same manner as in Example 1 using 1000 ml (409 g) of the obtained ozone decomposer, and the results are shown in Table 1.

Example 3 An ozone decomposing agent was obtained in the same manner as in Example 1 using 200 g of zinc peroxide, 1000 g of synthetic zeolite and 400 g of colloidal silica (containing about 20% of solid content) as a binder. A test was conducted in the same manner as in Example 1 using 1000 ml (575 g) of the obtained ozone decomposer, and the results are shown in Table 1.

Example 4 The same ozone decomposing agent as that used in Example 3 was used, and the ozone-containing gas was not humidified.
The test was carried out under exactly the same conditions as.

The results are shown in Table 1.

Example 5 An ozone decomposer was obtained in the same manner as in Example 1 except that 125 g of 50% calcium peroxide, 1000 g of natural zeolite and 100 g of sodium carboxymethyl cellulose salt as a binder were used. A test was conducted in the same manner as in Example 1 using 1000 ml (798 g) of the obtained ozone decomposing agent, and the result was
Shown in the table.

Example 6 200 g of sodium perborate, 200 g of silica magnesia, 800 g of natural zeolite and polyvinyl alcohol as a binder
Using 120 g, an ozone decomposing agent was obtained in the same manner as in Example 1. A test was conducted in the same manner as in Example 1 using 1000 ml (770 g) of the obtained ozone decomposer, and the results are shown in Table 1.

Example 7 In Example 6, sodium percarbonate was used instead of sodium perborate, and an ozone decomposing agent was obtained in the same manner as in Example 6 except that sodium percarbonate was used, and a test was conducted in the same manner as in Example 1 using this. did. The results are shown in Table 1.

Example 8 In Example 1, 1000 ml (510 g) of an ozone decomposing agent in which half of the synthetic zeolite was replaced with activated carbon was used, and the temperature was set to 25.
Tests were conducted in the same manner except that the temperature was changed to 0 ° C., and the effect of activated carbon was observed. The results are shown in Table 1.

Comparative Example 1 In order to see the effect of peroxide, 1000 g of the synthetic zeolite used in Example 3 and 400 g of colloidal silica (containing about 20% of solid content) as a binder were used, and zinc peroxide was not used. Molding was carried out in the same manner as in Example 1 to obtain a cylindrical agent. A test was conducted in the same manner as in Example 1 using 1000 ml (554 g) of the obtained agent, and the results are shown in Table 1.

Comparative Example 2 In order to see the effect of peroxide, 1000 g of natural zeolite used in Example 5 and 100 g of carboxymethyl cellulose sodium salt as a binder were used, and calcium peroxide was not used, and otherwise the same as in Example 1. And molded to obtain a cylindrical agent. A test was conducted in the same manner as in Example 1 using 1000 ml (744 g) of the obtained agent, and the results are shown in Table 1.

Example 9 200 g of 50% calcium peroxide, 550 g of activated carbon, 450 g of natural zeolite and carboxymethyl cellulose as a binder.
A columnar ozone decomposing agent was obtained in the same manner as in Example 1 except that 100 g of sodium salt was used. 200m of the obtained ozone decomposer
Fill l (96g) into a glass tube with an inner diameter of 35mm, and
The ozone-separated air, which had been adjusted to an ozone concentration of approximately 850 ppm at ℃), was passed through a water seal at a flow rate of 5 liters per minute to humidify it, then passed through the ozone decomposer, and the gas at the outlet was monitored by an ozone monitor. Then, the ozone concentration was detected. The data of the main breakthrough times are shown in Table 1.

Example 10 Using 50% calcium peroxide 200 g, activated carbon 1000 g, synthetic zeolite 350 g, silica aerosil 200 g and carboxymethylcellulose sodium salt 100 g as a binder,
A columnar ozone decomposing agent was obtained in the same manner as in Example 1. A test was conducted in the same manner as in Example 9 using 200 ml (104 g) of the obtained ozone decomposer, and the results are shown in Table 1.

Example 11 The same ozone decomposing agent as that used in Example 10 was used, and the test conditions were exactly the same except that ozone gas was supplied without passing through a water seal. The results are shown in Table 1.

Example 12 Zinc peroxide 250 g, activated carbon 1000 g, silica-alumina 450 g
A columnar ozone decomposing agent was obtained in the same manner as in Example 1, except that 200 g of silica aerosil and 100 g of sodium salt of carboxymethyl cellulose were used as a binder. A test was conducted in the same manner as in Example 9 using 200 ml (113 g) of the obtained ozone decomposer, and the results are shown in Table 1.

Comparative Example 3 Using 200 ml (130 g) of a commercially available ozonolysis agent (tablet product having activated carbon and Kanuma soil as main components and having a diameter of 8 mm),
The test was performed in the same manner as in Example 9. The breakthrough time data is shown in Table 1.

Comparative Example 4 A test was carried out in the same manner as in Example 9 using 200 ml (114 g) of granular commercially available activated carbon (cylindrical pellets having a diameter of 4 mm and a length of 2 to 8 mm). First data for breakthrough time
Shown in the table.

Comparative Example 5 The same activated carbon as the granular activated carbon used in Comparative Example 4 was used,
As a test condition, the test was performed under exactly the same conditions except that ozone gas was supplied without passing through a water seal. The results are shown in Table 1.

Example 13 The same ozone decomposing agent used in Example 10 was used.
After using 40 ml (21 g) and filling a stainless steel pipe with an inner diameter of 28 mm, ozone-containing air that had been adjusted to an ozone concentration of about 2000 ppm in advance was used at a flow rate of 1 liter per minute for about 50
The ozone decomposing agent was communicated at 0 ° C., and the gas at the outlet was guided to an ozone monitor to detect the ozone concentration. The data of the main breakthrough times are shown in Table 1.

Comparative Example 6 Granular molecular sieves (diameter 1 /
16-inch, 2-8 mm long cylindrical pellet) 40 ml (28
g) and used and tested in the same manner as in Example 13, and the results are shown in Table 1.

Example 14 To investigate the explosiveness of the ozone decomposing agent, the ozone decomposing agent 70 ml (36 g) used in Example 10 was filled in a stainless steel pipe having an inner diameter of 36 mm, which was previously generated by an ozonizer,
Ozone-containing air prepared to an ozone concentration of about 4200 ppm was passed through the ozone decomposing agent at about 30 ° C. at a flow rate of 2.5 liters per minute without being humidified. After 24 hours, the ozone-containing air was stopped, and the stainless pipe filled with the ozone decomposing agent was vibrated and shocked for 5 minutes with a shaker, but the ozone decomposing agent did not explode.

Comparative Example 7 An explosiveness test was conducted in the same manner as in Example 14, except that 70 ml (46 g) of the commercially available granular activated carbon used in Comparative Example 4 was used instead of the ozone decomposing agent. The granular activated carbon exploded as soon as it started to be shocked with a shaker.

<Effects of the Invention> According to the present invention, the following effects, which should compensate for the drawbacks of the conventional ozone decomposing agents, can be obtained. That is, the ozone decomposing activity does not decrease so much even at low temperatures and / or in the presence of water, and when decomposing and removing ozone contained in gas components, even under conditions of lower temperature and higher humidity than conventional conditions, It is possible to provide an ozone decomposing agent with high activity and long life.

Claims (2)

[Claims] 1. An ozone decomposer containing at least one selected from barium peroxide, calcium peroxide, zinc peroxide, sodium percarbonate and sodium perborate. 2. The ozone decomposing agent according to claim 1, which contains activated carbon.