JPH01242126A - Method and device for treating ozone - Google Patents

Abstract

PURPOSE:To prevent the surface of catalyst filter medium from getting wet by adjusting the relative humidity of the gas containing the waste ozone discharged from an ozone treatment and the by-product ozone generated from an electric discharge tube to be <=80%, and carrying out a catalytic treatment. CONSTITUTION:The gas to be treated is passed through a humidity adjusting chamber 1 from an influent pipe 5, and then treated in an ozone decomposing chamber 13 through a connecting pipe 8, and discharged through a treated gas effluent pipe 7. A humidity adjusting unit 2, such as a heater, and a baffle plate 8 to prevent a short circuit are disposed in the humidity adjusting chamber 1 so that the relative humidity of the influent gas containing ozone is adjusted to be <=80%. In the ozone decomposing chamber 3, the filter medium consisting of hollow cylindrical inorganic fiber or organic high molecular resin fiber on the surface of which a metal oxide catalyst is supported is provided to decompose ozone.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is designed to treat waste ozone discharged from ozone treatment used for purposes such as water treatment and air purification, and ozone by-produced from various discharge tubes. The present invention relates to a method and apparatus for removing the present invention.

[Conventional technology]

The use of ozone is expected to increase in the future, mainly in fields such as water treatment, sterilization, and air purification, but ozone remains in exhaust gas. Further, ozone is produced as a by-product from various discharge tubes and is discharged as is. The emitted ozone often exceeds environmental standards for air pollution, and must be treated.

Conventional technologies for treating waste ozone include activated carbon methods, chemical absorption methods, thermal decomposition methods, and catalytic methods.

The activated carbon method introduces ozone into an activated carbon packed bed and generates 203+C
"→30!+C" However, C0 is a method that decomposes ozone through a reaction called activated carbon, and this method is widely used because it can efficiently decompose low concentrations of ozone.

The chemical absorption method is a method in which ozone is absorbed into an aqueous reducing agent solution such as sodium sulfite, sodium thiosulfate, or ferrous salt, or an alkaline aqueous solution such as sodium hydroxide.

The pyrolysis method is a method for thermally decomposing heavy oil, light oil, etc. by introducing ozone into the combustion chamber.

Furthermore, catalytic methods include methods that use manganese dioxide as the main component, such as manganese oxide attached to the surface of sand, silica/alumina gel, and clay.

Ozone is introduced into a packed bed of a granular catalyst such as a mixture of activated carbon and manganese oxide and calcined, and mainly 203+M, 1O□ → 30□ +H,IO! This reaction decomposes ozone.

[Problem to be solved by the invention]

However, the conventional ozone treatment technology has the following drawbacks.

Disadvantages of the activated carbon method include powdering of activated carbon particles due to reaction with ozone, and reduction of activated carbon due to oxidation to carbon monoxide and carbon dioxide as a side reaction.

The dangers of ignition and increased explosion when coming into contact with high-concentration ozone are cited.

In the case of the chemical absorption method, the absorption capacity decreases due to changes in the composition of the chemical due to ozone absorption, which requires replenishment of the chemical and treatment of waste liquid, which is complicated.

The pyrolysis method is suitable for treating high concentrations of ozone where activated carbon treatment poses a risk of explosion, but it is expensive.

In addition, in the catalyst method, the ozone decomposition performance of the catalyst is low, and the processing speed cannot be increased.

The present invention utilizes a catalytic method, but uses a specific catalyst with a much larger surface area than conventional ones.
The purpose of the present invention is to provide an ozone treatment method and an ozone treatment device that enable safe and economical ozone treatment at a high ventilation rate, and that also make the device smaller and lighter, making it compact and easy to maintain. It is something to do.

[Means to solve the problem]

The present invention provides a comparative humidity level of the gas to be treated when passing the gas to be treated containing ozone through a packed layer of a filter material having a metal oxide catalyst supported on the surface of inorganic fibers or organic polymeric resin fibers. This ozone treatment method is characterized by adjusting the temperature to 80% or less and venting.

The present invention also provides a humidity control chamber equipped with an inlet for introducing a gas to be treated containing ozone, and a hollow cylindrical structure in which a metal oxide catalyst is supported on the surface of an inorganic fiber or an organic polymer resin fiber. an ozone decomposition chamber containing a molded filter medium, and the inside or outside of the hollow cylindrical filter medium in the ozone decomposition chamber is communicated with the humidity adjustment chamber, and the outside of the hollow cylindrical filter medium is connected to the ozone decomposition chamber. Alternatively, a process gas outlet communicating with the inside is provided, and the process gas flowing out from the humidity adjustment chamber passes through the hollow cylindrical filter medium by 1ffi and flows out from the process gas outlet. The present invention is an ozone treatment device, and the present invention further provides an ozone treatment device in which a filter material formed into a hollow cylinder shape by supporting a metal oxide catalyst on the surface of inorganic fibers or organic polymer resin fibers is housed in a container, and the hollow cylinder A humidity regulator is installed around the inside or outside of the hollow cylindrical filter medium, and an inlet for the ozone-containing gas to be treated is provided in the container to communicate with the humidity adjuster, and a humidity controller is provided around the outside of the hollow cylindrical filter medium. Alternatively, a process gas outlet communicating with the inside is provided, and the process gas flowing out from the humidity regulator passes through the hollow cylindrical filter material and flows out from the process gas outlet. This is an ozone treatment device.

[For production]

In the present invention, inorganic or organic polymer resins such as glass and metals are used in the fibrous, sponge, and Y4 shapes.

A filter material having a felt-like fiber as a carrier and carrying one or more metal oxide catalysts such as manganese, nickel, cobalt, copper, m, zinc, etc. on the surface of the carrier, preferably manganese oxide alone or manganese oxide. Since we use a packed bed of filter material that supports substances together with other metal oxides, its specific surface area can be reduced to 0. With a surface area of O05rd/cs3 or more, which is not found in conventional granular catalysts,
By ventilating a gas to be treated containing ozone into this packed bed, it becomes possible to perform processing at a high ventilation rate with a thin layer thickness that was previously unheard of.

Note that there is no problem when the relative humidity of the gas to be treated is 80% or less, but as the amount of moisture accompanying the gas to be treated increases, the decomposition of ozone tends to become insufficient. This problem is caused by the fact that the surface of the filter material, which is a catalyst, becomes wet with moisture, which inhibits contact with the gas to be treated. To prevent this, if the comparative humidity of the gas to be treated is 80% or higher, adjust the comparative humidity to 80% or lower by heating, cooling and dehumidifying, dehumidifying with a dehumidifier, etc. to prevent water condensation. It is necessary to carry out ventilation treatment.

In addition, the packed layer of the filter medium is preferably formed into a hollow cylindrical shape, and from the inside to the outside of this hollow cylindrical filter medium,
Alternatively, by ventilating the gas to be treated with a comparative humidity of 80% or less from the outside to the inside, it is possible to achieve an unprecedentedly thin layer thickness and high aeration rate, for example, when the thickness of the hollow cylindrical filter material is 50 to 2.
00ts SV2, 000~10,000 Nlll3
- Gas to be treated / Rin 3 - Effective treatment is possible by adjusting the ventilation rate of the filter material/h.

〔Example〕

An example of the apparatus of the present invention will be explained with reference to the drawings. In FIG. The carrier is made of inorganic or organic polymeric resin fibers such as metals, sponge-like, '4F4-like, felt-like fibers, etc., and manganese, nickel, and cobalt are applied to the surface of the carrier.

A filter medium 4 formed into a hollow cylindrical shape and supported with one or more metal oxide catalysts such as copper, silver, and zinc is accommodated.

An inflow pipe 5 for the gas to be treated containing ozone and a communication pipe 6 communicating with the ozone decomposition chamber 3 are connected to the humidity adjustment chamber l,
The gas to be treated that flows in from the inflow pipe 5 is heated by the heater 2, so that the relative humidity of the gas to be treated can be adjusted to 80% or less. Y! The communication pipe 6 of the temperature adjustment chamber l is
A process gas outflow pipe 7 is connected to the inside of the hollow cylindrical filter material 4 in the ozone decomposition chamber 3 and to the outside of the hollow cylindrical filter material 4 .

In the figure, 8 indicates a baffle plate for preventing short circuits that covers the indoor opening of the communication pipe 6 of the humidity adjustment chamber 1, and 9 indicates a baffle plate for guiding the gas to be treated to the hollow cylindrical filter material 4 inside the ozone decomposition chamber 3. This shows the baffle plate.

In the example shown in FIG. 2, a heater 2 serving as a temperature regulator is provided inside a hollow cylindrical filter material 4 in a container 11, and an inflow pipe 5 for the gas to be treated is connected to the container 11 so as to communicate with the heater 2. On the other hand, a processing gas outflow pipe 7 is connected to the outside of the hollow cylindrical filter material 4 so as to communicate therewith.

In these illustrated apparatuses, the gas to be treated containing ozone flows into the humidity adjustment chamber 1 or the container 11 from the inflow pipe 5, is heated by the heater 2, and is adjusted to a relative humidity of 80% or less, and is then contained in the gas. The ozone in the gas is decomposed by being vented from the inside to the outside of the hollow cylindrical filter medium 4, and then flows out from the treated gas outflow pipe 7.

In this case, the surface area of the filter medium is 0.005 m”/c
2,000 to 10,000 without increasing pressure loss even with a thin layer of 50 to 200 tm.
HIII! - Gas to be treated / Ugly 3 - Processing at a high aeration rate of 3-filter material / h is possible, enabling high-speed processing that cannot be achieved with conventional granular catalysts.

In the example shown in FIG.
However, the gas to be treated flowing out from the humidity adjustment chamber 1 is filtered through the hollow cylindrical filter material 4.
The process gas outlet pipe 7 is guided to the outside and directed to the inside.
It can be configured so that it flows from the

Furthermore, in the example shown in FIG. 2, the flow of the gas to be treated passes through the heater 2 from the inside to the outside of the hollow cylindrical filter medium 4 and flows out from the process gas outlet pipe 7.
is disposed around the outside of the hollow cylindrical filter material 4, and the gas to be treated passes through the heater 2 from the outside to the inside of the hollow cylindrical filter material 4, and is configured to flow out from the treated gas outflow pipe 7. You can also do that.

Next, an experimental example will be shown.

(Experimental Example 1) An example of the treatment of the present invention performed on waste ozone gas discharged at a human waste treatment plant A will be shown.

The properties of waste ozone gas are: temperature 30℃, ozone concentration 6g/
Nrrl, absolute 18 degrees is 0.299 kg/bet',
The comparative humidity was 110%.

The catalyst used as the filter material is made by supporting manganese, cobalt, and zinc oxides on organic polymer resin fibers with an average diameter of 0.311 and molding them into a hollow cylindrical body with a layer thickness of 200 m1. The comparative humidity of the waste ozone gas was adjusted to 20% by the method, and the SV was changed to allow ventilation from the inside to the outside of the hollow cylindrical filter material.

These results are shown in the table below, and 5V=2.
OOO~10.000 Nr+? The environmental standard for oxidants in the range of /ffl・h is 0, 06 shof, pp
It was processed below +w.

Furthermore, the raw gas and catalyst conditions were made the same, and 5v=2.
FIG. 3 shows changes in the ozone concentration of the treated gas when the relative humidity was changed in the treatment of 000 Nrd/rd·h.

In order to completely remove ozone, it is desirable to keep the relative humidity at around 20%, but the relative humidity up to 80% is 0.06vo1.0, which is the environmental standard for oxidants. It was processed to less than pp+s, and when it exceeded 80%, the processing deteriorated rapidly.

(Experimental Example 2) An example of the treatment of the present invention performed on ozone gas by-produced from an ultraviolet lamp is shown.

The properties of ozone gas are: temperature 20℃, ozone concentration 10vo
1. ppm, and the comparative humidity was 70%.

The catalyst, which is the filter material, is made of inorganic fibers with an average diameter of 0.05 m and a layer thickness of 10 m, supporting oxides of manganese and cobalt zinc.
0111, and ozone gas was passed through the packed bed while changing the Sv without adjusting the comparative humidity.

These results are shown in the table below, and 5V = 2,000 to 10,0OONr+? without humidity adjustment. /
n?・0 where the environmental group of the oxidant <B in the range of h
, 06vo1. It was processed below pps.

(Experimental Example 3) FIG. 4 shows a comparison of pressure loss between the case where conventional manganese sand was used and the case where the catalyst according to the present invention was used.

Figure 4 shows the linear velocity of ventilation to the catalyst LV (Nn?/n(-h
) and the pressure drop per catalyst loom thickness. Manganese sand has an effective diameter of 0.61, and the present invention (2) has manganese oxide supported on inorganic fibers with an average diameter of 0.05 l*. The product, Kiana Akira ■, is made by supporting manganese oxide on organic polymer fibers with an average diameter of 0.3.

Among these, the pressure of the invention
to/100 m-catalyst. ta fiber diameter 005
The pressure of ml of the present invention (2) was about twice that of (2).

On the other hand, the pressure of manganese sand is LV8 ONm
/n(・h stage already 240Hz/100m
- catalyst, treatment with manganese sand usually has a bed height of 600
Since it requires ~1000m, it can be seen that it cannot be made very fast from the viewpoint of ventilation resistance.

Furthermore, an example of waste ozone gas treatment using manganese sand is shown in Fig. 5, but even if the comparative humidity is adjusted to 20% using a heating method, Sv is still 40 ON n? /ffl・h could not be processed.

Further, it is thought that the limiting factor for the shape of the ozone treatment apparatus of the present invention is not the ozone concentration of the waste gas or the treatment S, but the magnitude of the pressure loss. Therefore, when the amount of gas to be processed is large, a filling format with a large cross-sectional area and small layer thickness is required, so a hollow cylindrical format is used rather than a simple packed bed format, and Alternatively, it is advantageous to have a shape that allows ventilation from the outside to the inside.

[Effects of the Invention] As described above, according to the present invention, the filtration medium used is one having an extremely large surface area, in which manganese or other metal oxide catalysts are supported on the surface of inorganic fibers or organic polymer resin fibers. The pressure and temperature are low, enabling high-speed processing that could not be achieved with conventional granular catalysts.Furthermore, by adjusting the relative humidity of the gas to be treated to less than 80%, effective treatment is ensured, making it highly safe and economical. By molding this filter material into a hollow cylindrical shape, the device can be made smaller and lighter, and many beneficial effects can be expected, such as making it compact and easy to maintain.

[Brief explanation of the drawing]

1 and 2 are longitudinal sectional views showing examples of the apparatus of the present invention, FIG. 3 is a diagram showing the relationship between relative humidity and ozone concentration of the treated gas in the present invention, and FIG. 4 is a diagram showing the relationship between the LV to the catalyst and the FIG. 5 is a diagram showing the relationship between pressure loss per 100 catalyst thicknesses, and FIG. 5 is a diagram showing the relationship between Sv and treated gas ozone concentration when conventional manganese sand is used. ■... Humidity control chamber, 2... Heater, 3... Ozone decomposition chamber, 4... Hollow cylindrical filter material, 5... Inflow pipe for gas to be treated, 6... Communication pipe, 7... Processing gas outflow pipe, 8.9... Baffle plate, 11... Container. Patent applicant Ebara Infilco Corporation Patent applicant
Ebara Research Institute Co., Ltd. Representative Patent Attorney Pharmaceutical
Teacher Minoru Agent Patent Attorney Yori 1) Takatsugu Department Agent Patent Attorney Tadashi Takagi Comparison Humidity (χ) Figure 5 5V (N myrm3-h)

Claims (3)

[Claims] (1) When passing the ozone-containing gas to be treated through a packed layer of a filter material in which a metal oxide catalyst is supported on the surface of inorganic fibers or organic polymeric resin fibers, the relative humidity of the gas to be treated is determined. An ozone treatment method characterized by adjusting the ozone concentration to 80% or less and aeration. (2) A humidity control chamber equipped with an inlet through which a gas to be treated containing ozone flows, and a metal oxide catalyst supported on the surface of inorganic fibers or organic polymer resin fibers formed into a hollow cylindrical shape. an ozone decomposition chamber containing a filter medium, the inside or outside of the hollow cylindrical filter medium in the ozone decomposition chamber is communicated with the humidity adjustment chamber, and the ozone decomposition chamber is connected to the outside or inside of the hollow cylindrical filter medium. An ozone treatment apparatus characterized in that a processing gas outlet communicating with the humidity control chamber is provided, and the processing gas flowing out from the humidity adjustment chamber passes through the hollow cylindrical filter material and flows out from the processing gas outlet. . (3) A filtration medium formed into a hollow cylindrical shape by supporting a metal oxide catalyst on the surface of inorganic fibers or organic polymeric resin fibers is housed in a container, and the inner or outer periphery of the hollow cylindrical filtration medium is accommodated. a humidity regulator is provided in the container, an inlet for a gas to be processed containing ozone is provided in the container to communicate with the humidity regulator, and a processing gas flow is provided in the container to communicate with the outside or inside of the hollow cylindrical filter material. An ozone treatment apparatus characterized in that an outlet is provided so that the treated gas flowing out from the humidity regulator passes through the hollow cylindrical filter material and flows out from the treated gas outlet.