JP2002336343A - Plasma catalytic reactor and air purification device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance plasma activity in a plasma catalytic reactor (20) combining low-temperature plasma and a manganese-based catalyst, to sufficiently promote a chemical reaction of a fluid to be treated, and to enhance treatment performance. SOLUTION: Corona discharge,
Low-temperature plasma is generated by creeping discharge, silent discharge, or partial discharge, and the fluid to be treated is processed by combining the low-temperature plasma with a manganese-based catalyst.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma catalyst reactor and an air purification device for promoting a chemical reaction of a fluid to be treated by combining a low-temperature plasma generated by electric discharge with a catalyst, and more particularly to a manganese catalyst. Pertaining to a plasma catalyst reactor or the like.

[0002]

2. Description of the Related Art Conventionally, a plasma catalytic reactor for treating a fluid to be treated by combining a low-temperature plasma and a catalyst has been proposed. This plasma catalytic reactor is, for example, an air purifier (a deodorizer or an air purifier) in order to decompose and deodorize odorous substances and harmful substances in a fluid to be treated (air to be treated and gas to be treated). ), Air conditioners, garbage treatment equipment, exhaust gas treatment equipment, etc.

[0003] For example, Japanese Patent Application Laid-Open No. 6-262032 discloses a gas purifying apparatus which generates low-temperature plasma by glow discharge and purifies exhaust gas by combining the low-temperature plasma with a manganese catalyst as a plasma catalytic reactor. Is disclosed. This gas purifier reacts highly reactive substances (eg, active species such as electrons, ions, ozone, and radicals) in low-temperature plasma generated by discharge with harmful substances and odorous substances in the presence of a catalyst. By these, these substances are decomposed and removed.

[0004]

However, the low-temperature plasma generated by the glow discharge has a small activating power and cannot sufficiently promote a chemical reaction in the presence of a catalyst. Even when combined with a system catalyst,
It has been difficult to obtain sufficient performance for treating a fluid to be treated as a plasma catalytic reactor.

The present invention has been made in view of the above problems, and has as its object to reduce the plasma activating power in a plasma catalytic reactor combining low-temperature plasma and a manganese-based catalyst. To enhance the processing performance by promoting the chemical reaction of the fluid to be treated more strongly.

[0006]

According to the present invention, in a plasma catalytic reactor (20) using a manganese-based catalyst, a discharge method is specified as a method having a high activating power.

More specifically, a first solution taken by the present invention is a discharge means (21, 22) for generating a low-temperature plasma by discharge in a flow space of a fluid to be treated, and the discharge means (21, 22). Catalyst means (23) arranged in the discharge field (D) or downstream of the discharge field (D), wherein the catalyst means (23) is a plasma catalyst reactor (20) containing a manganese-based catalyst. And And this plasma catalytic reactor (20)
(21, 22) is characterized in that low-temperature plasma is generated by corona discharge, creeping discharge, silent discharge, or partial discharge. Various high-voltage power supplies such as direct current, alternating current, and pulse can be used as a power supply for causing these discharges according to a discharge method.

[0008] In the plasma catalytic reactor (20) according to the first solution, in the discharge field (D) of the discharge means (21, 22), low temperature is generated by corona discharge, creeping discharge, silent discharge or partial discharge. Plasma is generated. Then, highly reactive substances (eg, active species such as electrons, ions, ozone, and radicals) generated by these discharges are further excited in the presence of a catalyst to react with harmful substances and odorous substances, thereby causing damage. Harmful substances and the like in the processing fluid are decomposed and removed.

[0009] The second solution taken by the present invention is:
In the plasma catalytic reactor (20) according to the first solution, the manganese-based catalyst (Mn or Mn oxide (MnO ₂ , Mn ₂ O _3, etc.)) contained in the catalyst means (23) is contained in the catalyst component. According to a third aspect of the present invention, there is provided a plasma catalytic reactor (20) according to the second aspect, wherein:
The manganese-based catalyst contained in (23) is 30 to 4
It is characterized by containing 0% by mass.

In the above second and third solving means, M
Since the content of the manganese-based catalyst such as n, MnO ₂ , or Mn ₂ O ₃ is specified, the processing performance of the plasma catalytic reactor (20) is optimized. Conversely, M in the catalyst component
If the content of n, MnO ₂ , or Mn ₂ O ₃ is too small, the ability to decompose harmful substances will be insufficient, and if the content is too large, the specific surface area of the catalyst will be small and the performance will deteriorate. , The optimum performance is obtained.

[0011] A fourth solution taken by the present invention is:
In the plasma catalytic reactor (20) according to the first, second or third solving means, the discharge field (D) of the discharging means (21, 22)
An adsorption means (23) for adsorbing the component to be treated contained in the fluid to be treated is arranged together with the catalyst means (23) in the middle or downstream of the discharge field (D).

In the fourth solution, the component to be treated contained in the fluid to be treated is adsorbed by the adsorption means (23), so that the active species contained in the low-temperature plasma comes into contact with the catalyst and is further excited. Then, these active species act on the components adsorbed by the adsorbing means (23) together with the components contained and suspended in the fluid to be treated, and decompose and remove these components.

Further, a fifth solution taken by the present invention is:
The present invention relates to an air purification device using the plasma catalytic reactor (20) according to the first, second, third or fourth solution. This air purification device (1) includes a casing (10) in which the plasma catalytic reactor (20) is housed, and introduces air to be treated into the casing (10) to discharge means (21,
The odor component or the harmful component in the air to be treated is treated by passing through the discharge field (D) of 22) and the catalyst means (23).

In the fifth solution, the odor component or the harmful component in the air to be treated is reduced by the low-temperature plasma and the catalyst means (23).
Thus, the air to be treated is purified by performing a treatment such as oxidative decomposition.

[0015]

According to the first solution, a low-temperature plasma is generated by using corona discharge, creeping discharge, silent discharge, or partial discharge having a higher activation ability than glow discharge. Since a manganese-based catalyst is used in combination, the activity can be significantly increased by further exciting active species that promote a chemical reaction in the presence of the catalyst as compared with glow discharge. Therefore, the capacity of the plasma catalytic reactor (20) can be increased.

According to the second and third means, since the content of Mn, MnO ₂ , Mn ₂ O _{3 and the} like is specified in the optimum range, the content of the plasma catalytic reactor (20) is reduced. Processing performance can be further improved.

According to the fourth solution, the adsorbing means (23) for adsorbing the component to be treated contained in the fluid to be treated is combined with the catalyst means (23) in the discharge field (D) or in the discharge field (D). ) And adsorbs the component to be treated of the fluid to be treated.
Since the reaction is carried out in the presence of the catalyst while being adsorbed in (23), the active species of the low-temperature plasma surely acts on these components and decomposes these components. Therefore, processing performance can be further improved. Further, even if the discharge time is shortened, such as intermittent discharge, the processing performance can be prevented from lowering, so that it is possible to improve energy saving.

According to the fifth solution, the low-temperature plasma generated by using corona discharge, creeping discharge, silent discharge, or partial discharge, which has higher activation ability than glow discharge, and a manganese-based catalyst are used. Since the air to be treated containing harmful substances and odorous substances is treated in combination with the catalyst means (23), the treatment capacity of the air purification device (1) can be increased.

[0019]

Embodiment 1 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

This embodiment relates to an air purification device (1) for purifying air by treating odorous or harmful components in the air to be treated by oxidative decomposition or the like. FIG. 1 shows this air purification device (1). ) Is shown. FIG. 2 is a cross-sectional view schematically showing the structure of the air purification device (1), and FIG. 3 is a schematic view showing a discharge method.

As shown in the figure, the air purifying apparatus (1) has a configuration in which various functional parts are housed in a casing (10). As the functional parts, a dust collecting filter (11) and a centrifugal fan (1) are provided.
2) and the plasma catalytic reactor (20) are housed in a casing (10). In FIG. 1, reference numeral (13) denotes an ozone decomposition catalyst for decomposing ozone generated by electric discharge.

An air inlet (15) for sucking air into the casing (10) is formed on one side face (right side face in the figure) of the casing (10), and a purified air is blown on the upper face. Air outlet (16) is formed. Air inlet
(15) is provided with a suction grill (15a) and an air outlet (16)
Is provided with an outlet grill (16a). The dust suction filter (11) is arranged in the air suction port (15) inside the suction grille (15a) so as to collect dust contained in the suction air.

The air outlet (16) is formed on the upper surface of the casing (10) at the edge opposite to the air inlet (15) (the left edge in FIG. 1). And this air outlet
Corresponding to (16), the centrifugal fan (12) is
Is provided within. The centrifugal fan (12) is connected to a fan power supply (12a). In the above configuration,
The inside of the casing (10) has an air inlet (15) and an air outlet
The space between (16) is the circulation space of the air to be treated. Then, when the centrifugal fan (12) is started, the air to be treated is sucked into the casing (10) through the suction grill (15a) of the air suction port (15) and the dust filter (11), and the reaction described in detail below is performed. After processing in the vessel (20), the outlet grill (16) of the air outlet (16)
a) is blown out of the casing (10).

The plasma catalytic reactor (20) includes a discharge electrode (21) as discharge means for generating low-temperature plasma.
And a counter member (22), and a processing member (23) disposed between the electrodes (21, 22) and close to the counter electrode (22). That is, the processing member (23) is disposed in the discharge field (D). Although not shown in detail, the processing member (23) is formed of a honeycomb-shaped substrate (23a) having a number of small holes penetrating in the direction of air flow. Processing material
(23) constitutes a catalyst structure (catalyst means) which carries at least a manganese-based catalyst on its surface and promotes a chemical reaction when treating the air to be treated. The catalyst structure (23) contains manganese-based catalysts Mn, M
nO ₂ or have the like Mn ₂ O ₃ containing 30 to 40 wt%. Although this content specifies a suitable range, the catalyst structure (23) contains Mn, MnO ₂ ,
Alternatively, any material containing Mn ₂ O ₃ or the like in an amount of 10 to 60% by mass may be used.

The processing member (23) also carries an adsorbent together with a catalyst on the surface of the substrate (23a). The adsorbent adsorbs components to be treated such as odorous substances and harmful substances contained in the air to be treated, and for example, activated carbon or zeolite is used. Therefore, in this configuration, the processing member (23) is not only a catalyst structure but also an adsorption structure (adsorption means).

A plate-like electrode plate is used for each of the discharge electrode (21) and the counter electrode (22), and a large number of openings are provided so that air passes in a direction perpendicular to the plane.
For example, a mesh material, a punching metal, or the like can be used for each of the electrodes (21, 22). In addition, discharge electrodes (2
Although not shown in 1) and the counter electrode (22), it is preferable to form minute projections on the surface on the side of the opposing electrode (22, 21), thereby stably discharging. Can wake up.

A high-voltage power supply (24), which is a combination of direct current, alternating current, and pulse, is connected to both electrodes (21, 22), and a corona is provided between the discharge electrode (21) and the counter electrode (22). Discharge is caused to occur. This corona discharge causes the discharge field
In (D), low-temperature plasma is generated. For low-temperature plasma,
The active species include radicals such as fast electrons, ions, ozone, and hydroxyl radicals, and other excited molecules (excited oxygen molecules, excited nitrogen molecules, excited water molecules, and the like).

When a pulsed high-voltage power supply is used, discharge can be generated with higher energy, so that the activity of low-temperature plasma generated in the discharge field (D) can be further increased. Then, since these active species react with harmful components of the air to be treated in the presence of the catalyst and decompose these components, higher treatment performance can be obtained.

-Operation- Next, the operation of the air purification device (1) will be described.

When the operation of the air purification device (1) is started and the centrifugal fan (12) is started, first, air to be processed is sucked from the air suction port (15), and dust contained in the air is collected. The dust is collected by the dust filter (11). During operation of the device (1), corona discharge occurs between the discharge electrode (21) and the counter electrode (22) of the plasma catalytic reactor (20), and the dust collection filter (1) is operated.
The air from which dust has been removed in 1) passes through the discharge field (D) between the electrodes (21, 22). The air to be treated is turned into plasma by the action of corona discharge, and becomes low-temperature plasma. The various active species generated by this discharge are further highly excited by contacting the catalyst of the processing member (23) to increase the activity, and efficiently react with harmful substances and odorous substances. Decompose and remove the substance.

Since the treatment member (23) also contains an adsorbent, harmful substances and odorous substances in the air to be treated are adsorbed by the adsorbent, and the active species of the low-temperature plasma are surely absorbed by these components. Acts to accelerate the decomposition process. In other words, by including the catalyst and the adsorbent in one processing member (23), more stable processing is performed.

According to the first embodiment, the low-temperature plasma is generated by using corona discharge, which provides an active species having higher activity than the glow discharge. Since a manganese-based catalyst is used in combination with an adsorbent, the chemical reaction in treating the air to be treated can be greatly promoted. Therefore, since the processing capacity of the plasma catalytic reactor (20) can be increased,
The capacity as an air purification device can also be increased.

FIG. 4 is a graph in which the efficiency of decomposition of toluene by the present reactor (20) is plotted on the ordinate and the content of MnO ₂ is plotted on the abscissa. the MnO ₂ can be obtained relatively high decomposition efficiency as long as the catalyst containing 10 to 60 wt%, especially if a catalyst containing MnO ₂ 30 to 40 wt%, it is possible to obtain a very high decomposition efficiency .

[0034]

[Embodiment 2] In Embodiment 2 of the present invention, low-temperature plasma is generated by creeping discharge in a plasma catalytic reactor (20). That is, in the first embodiment, corona discharge is caused between the electrodes (21, 22) as shown in FIG. 3, whereas in the second embodiment, the electrodes (21, 22) is different from the first embodiment. In the second embodiment, only the configuration of the discharging means (21, 22) will be described with reference to FIG.

In the second embodiment, an electrode plate (25) made of a dielectric substrate (25a) such as a ceramic is used.
The electrode plate (25) is provided with a discharge electrode (21) and a counter electrode (22) inside and on the surface of the dielectric substrate (25a). Then, a high-frequency AC voltage (or a high-frequency pulse voltage) is applied between the two electrodes (21, 22) from a power supply (not shown) to generate a creeping discharge and convert the air to be processed into plasma.

In this case, the entire surface around the electrode plate (25)
(D), and low-temperature plasma containing active species is generated in the discharge field (D). Then, a catalyst structure (23) containing the manganese-based catalyst described in each of the above embodiments is arranged downstream of the electrode plate (25), and active species contained in the plasma are transferred to the catalyst structure (23). They are being supplied.

In the third embodiment, a low-temperature plasma is generated by using a creeping discharge capable of obtaining active species more active than the glow discharge, and the low-temperature plasma is combined with a manganese-based catalyst. Therefore, the chemical reaction in treating the air to be treated can be greatly promoted. Therefore, the plasma catalytic reactor (20)
Air purification equipment
The ability as (1) can be greatly increased.

[0038]

Embodiment 3 Embodiment 3 of the present invention employs silent discharge as a discharge method in a plasma catalytic reactor (20). In the third embodiment, only the configuration of the discharging means (21, 22) will be described with reference to FIG.

In the plasma catalytic reactor (20), the discharge electrode (21) and the counter electrode (22) are each constituted by a plate-like electrode. An insulating plate (26) is laminated on each of the discharge electrode (21) and the counter electrode (22), and both electrodes (21, 22) are
26) They are arranged facing each other with the inside. And both electrodes
A high-voltage power supply (not shown) for applying a high-frequency AC voltage (or a high-frequency pulse voltage) is connected to (21, 22).

The discharge electrode (21) and the counter electrode (22) are arranged substantially parallel to the flow direction of the fluid to be processed so that the fluid to be processed flows between them. And, on the downstream side of the discharge field (D) formed between the discharge electrode (21) and the counter electrode (22),
The catalyst structure (23) including the manganese-based catalyst described in each of the above embodiments is arranged.

In this configuration, when a high-frequency AC voltage or a high-frequency pulse voltage is applied between both electrodes (21, 22),
A discharge field (D) of silent discharge is formed via the insulating plate (26). Then, low-temperature plasma containing various active species is generated by the silent discharge, and the active species flows to the catalyst structure (23). Therefore, the active species is further excited by contacting the manganese-based catalyst, the activity is enhanced, and reacts with harmful components of the air to be treated, and decomposes these components.

In the third embodiment, a low-temperature plasma is generated by using a silent discharge in which an active species having a higher activity than that of a glow discharge is obtained, and the low-temperature plasma is combined with a manganese-based catalyst. Therefore, the chemical reaction in treating the air to be treated can be greatly promoted. Therefore, the plasma catalytic reactor (20)
Air purification equipment
The ability as (1) can be greatly increased.

[0043]

Embodiment 4 Embodiment 4 of the present invention employs a partial discharge as a discharge method in a plasma catalytic reactor (20). In the fourth embodiment, only the structure of the discharging means (21, 22) will be described with reference to FIG.

In this plasma catalytic reactor (20), the discharge electrode (21) is constituted by a linear electrode, and the counter electrode (22) is constituted by a cylindrical electrode arranged around the discharge electrode (21). I have. A high-voltage power supply (not shown) for applying a high-frequency AC voltage (or a high-frequency pulse voltage) is connected to both electrodes (21, 22). In this configuration, a discharge field (D) is formed inside the cylindrical counter electrode (22). Note that a cylindrical (or rod-shaped) electrode thicker than the linear electrode shown in the figure may be used as the discharge electrode (21).

The inside of the counter electrode (22) is filled with catalyst particles (23) containing a manganese-based catalyst. That is, the catalyst particles (23) are arranged in the discharge field (D), and the plasma catalyst reactor (20) takes the form of a so-called packed bed reactor. The catalyst particles (23) are obtained by supporting a catalyst on the surface of ferroelectric particles such as barium titanate. This catalyst contains 10 to 60% by mass of a manganese-based catalyst such as Mn, MnO ₂ , or Mn ₂ O ₃ , preferably M, as in the above embodiments.
n, MnO _2, or a manganese-based catalysts such as Mn ₂ O ₃ 3
Those containing 0 to 40% by mass are used.

In this configuration, when a high-frequency AC voltage or a high-frequency pulse voltage is applied between the two electrodes (21, 22), the discharge electrode (21) moves from the counter electrode (22) through the ferroelectric catalyst particles (23). A partial discharge is generated toward the, and a low-temperature plasma containing various active species is generated in the discharge field (D). The generated active species comes into contact with the manganese-based catalyst of the catalyst particles (23), and is further excited, so that the activity becomes higher.
Then, the active species react with harmful components of the air to be treated and decompose these components.

In the fourth embodiment, a low-temperature plasma is generated by using a partial discharge that provides an active species that is more active than the glow discharge, and the low-temperature plasma is combined with a manganese-based catalyst. Therefore, the chemical reaction in treating the air to be treated can be greatly promoted. Therefore, the plasma catalytic reactor (20)
Air purification equipment
The ability as (1) can be greatly increased.

[0048]

Other Embodiments of the Invention The present invention may be configured as follows with respect to the above embodiment.

For example, in the first embodiment, the catalyst structure
(23) is arranged near the counter electrode (22) in the discharge field (D) formed between the discharge electrode (21) and the counter electrode (22),
The catalyst structure (23) may be arranged downstream of the discharge field (D) as shown in FIG. Further, the catalyst structure (23) may be disposed slightly away from the counter electrode (22), and the effect of the catalyst structure (23) can be obtained as long as the position is within a range where the plasma acts. .

In the partial discharge method shown in FIG. 7, instead of filling the cylindrical counter electrode (22) with catalyst particles, a cylindrical honeycomb is formed in the counter electrode (22) as shown in FIG. A catalyst structure (23) may be mounted. In this case, the ventilation resistance is smaller than in the example of FIG. 7, and the processing gas amount can be increased. Also in this case, a cylindrical electrode or a rod-shaped electrode may be used as the discharge electrode (21).

As shown in FIG. 10, catalyst particles or a honeycomb catalyst structure (23), a cylindrical glass tube (27), and a cylindrical The electrodes (counter electrodes) (22) may be arranged so as to be sequentially stacked from the inside. In this case, a ferroelectric is used as the base material of the catalyst structure (23). With this configuration, the discharge electrodes (2
When the electrons emitted from 1) move radially outward through the honeycomb catalyst structure (23) and accumulate charges on the inner surface of the glass tube (27), the charges act to reduce the potential difference.
A stable discharge can be generated without sparking.

9 and 10, the use of the same manganese-based catalyst as described above effectively utilizes the active species contained in the low-temperature plasma to promote the chemical reaction of the fluid to be treated. Therefore, the processing performance can be improved.

In the examples shown in FIGS. 9 and 10, a pulse power supply or an AC power supply may be used.

On the other hand, in the above-described embodiment, the processing member (23) is configured to have both functions of the catalyst means and the adsorption means, but the catalyst structure and the adsorption structure are formed by the discharge field (D).
It may be placed separately inside or downstream of it.

Further, in each of the above embodiments, an example in which the plasma catalytic reactor (20) is applied to the air purification device (1) has been described. The present invention can also be applied to other apparatuses that process the fluid to be processed, such as a processing machine.

[Brief description of the drawings]

FIG. 1 is a structural diagram of an air purification device provided with a plasma catalytic reactor according to Embodiment 1 of the present invention.

FIG. 2 is a diagram schematically showing a configuration of the air purification device of FIG.

FIG. 3 is a schematic diagram showing a discharge method of the plasma catalytic reactor of FIG.

FIG. 4 is a graph showing the toluene decomposition efficiency of a manganese-based catalyst.

FIG. 5 is a schematic diagram showing a discharge method of a plasma catalytic reactor according to Embodiment 2.

FIG. 6 is a schematic diagram showing a discharge method of a plasma catalytic reactor according to Embodiment 3.

FIG. 7 is a schematic diagram showing a discharge method of a plasma catalytic reactor according to Embodiment 4.

FIG. 8 is a schematic diagram showing a modification of the first embodiment.

FIG. 9 is a schematic diagram showing a first modification of FIG. 6;

FIG. 10 is a schematic diagram showing a second modification of FIG.

[Explanation of symbols]

 (1) Air purification device (10) Casing (11) Dust collection filter (12) Centrifugal fan (15) Air inlet (gas inlet) (16) Air outlet (gas outlet) (20) Plasma catalytic reactor (21) Discharge electrode (discharge means) (22) Counter electrode (discharge means) (23) Processing member (catalyst means, adsorption means) (24) High voltage power supply

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B01J 19/08 B01J 19/24 A 19/24 H05H 1/48 H05H 1/48 B01D 53/36 H (72 Inventor Kanji Mogi 1304 Kanaokacho, Sakai City, Osaka Prefecture Daikin Industries, Ltd.Sakai Seisakusho Kanaoka Plant F-term (reference) 4C080 AA05 AA09 BB02 CC01 HH05 JJ03 KK08 LL10 MM04 MM05 QQ11 4D048 AA22 AB01 BA28X BA41X BB02 A0304 AA37 BA05 BA06 BD14 CA15 CA47 CA54

Claims (5)

[Claims] A discharge means for generating low-temperature plasma by discharge in a flow space of a fluid to be treated;
Catalyst means (23) disposed in the discharge field (D) or downstream of the discharge field (D) in (21, 22).
Is a plasma catalytic reactor containing a manganese-based catalyst, and the discharging means (21, 22) is configured to generate low-temperature plasma by corona discharge, surface discharge, silent discharge, or partial discharge. Characteristic plasma catalytic reactor. 2. The plasma catalytic reactor according to claim 1, wherein the manganese-based catalyst contained in the catalyst means (23) is contained in an amount of 10 to 60% by mass in the catalyst component. 3. The plasma catalytic reactor according to claim 2, wherein the manganese-based catalyst contained in the catalyst means (23) is contained in an amount of 30 to 40% by mass in the catalyst component. 4. An adsorbing means (23) for adsorbing a component to be treated contained in a fluid to be treated is disposed in the discharge field (D) of the discharge means (21, 22) or downstream of the discharge field (D). 4. The arrangement according to claim 1, wherein said catalyst is arranged together with said catalyst means.
A plasma catalytic reactor as described. 5. The plasma catalyst reactor according to claim 1, 2, 3, or 4, and a casing (10) in which the plasma catalyst reactor (20) is housed. 10) Introduce air to be treated into and discharge means
(21, 22) through the discharge field (D) and the catalyst means (23) to treat odorous or harmful components in the air to be treated. apparatus.