JP2002239344A - Device and method for treating gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new gas treatment technology for a device and a method for treating gas. SOLUTION: This device for treating gas is provided with a pipe made of an electric insulation material and defined as a gas passage, the first inside electrode arranged in the upstream side of the pipe, the first outside electrode arranged oppositely to the first inside electrode at the outside of the pipe, the second inside electrode arranged in the downstream side of the first inside electrode in the pipe and the second outside electrode arranged oppositely to the second inside electrode at the outside of the pipe. The PACT(plasma-assisted catalytic technology) treatment by two steps can effectively decompose the gas to be treated and synthesize an efficiently utilizable gas.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a gas processing apparatus and a gas processing method, and more particularly to, but not limited to, a gas processing apparatus and a gas processing method suitable for processing waste gas containing harmful gas.

[0002]

2. Description of the Related Art The present inventors and co-workers have
Plasma-assisted catalytic technology (PAC) that generates plasma at normal pressure and atmospheric pressure and causes a chemical reaction of the gas to be treated under catalytic action
T) (USP 5,474,747 (Japanese Patent Publication No. 8-22367), USP 6,027,617, etc.).

In the industrial field such as semiconductor device manufacturing, various gases are used during the process, and the used gas is discarded. If the gas to be discarded is harmful, it is desirable to detoxify and discard. Even if it is not harmful directly or in the short term, if it accumulates in the long term, it will cause environmental effects such as global warming, and there are also gases such as Co ₂ and fluorocarbons that are desired to reduce the amount of waste. .

In the manufacture of semiconductor devices, etching is used for etching.
Fluorocarbon is used. CF _Four, C_TwoF₆, C_ThreeF₈
Can have a high global warming potential
Are known. Directly harm human body by nitrogen dilution etc.
No concentration, even if accumulated in the atmosphere,
The impact on the environment is great.

Conventionally, CF_FourO_Two, H_TwoUnder reduced pressure in the presence of O
Plasma treatment with CO_TwoAnd HF conversion technology, C
F_FourTo Ca (OH)_TwoPlasma treatment in the presence and at atmospheric pressure
And CO _Two, HF, CaF_TwoConversion technology etc. are proposed
Have been. The former has problems with by-products and
The possibility of disturbing the chucking process has not been eliminated.
No. The latter achieves high conversion efficiency, but consumes less power.
Is high.

[0006]

An object of the present invention is to provide a novel technique for gas treatment.

Another object of the present invention is to provide a novel gas processing technology that contributes to effective use of resources.

Yet another object of the present invention is to further improve PACT tailored to the purpose.

[0009]

According to one aspect of the present invention, there is provided a pipe formed of an electrical insulator and defining a gas flow path, and a first inner electrode disposed upstream of the pipe. A first outer electrode disposed to face the first inner electrode outside the pipe, and a first outer electrode in the pipe.
There is provided a gas processing apparatus having a second inner electrode disposed downstream of the inner electrode and a second outer electrode disposed outside the pipe so as to face the second inner electrode.

According to another aspect of the present invention, (a) a gas to be treated containing at least a first type gas and a second type gas is placed in a pipe formed of an electrical insulator and defining a gas flow path. A step of introducing under an atmospheric pressure; and (b) a first inner electrode disposed upstream in the pipe and having a catalytic action on the gas to be treated, and facing the first inner electrode outside the pipe. Between the first outer electrode and the first outer electrode.
Applying an excitation voltage to generate a first atmospheric pressure plasma in the pipe to decompose at least a first type gas in the processing target gas; and (c) downstream from the first inner electrode in the pipe. A second inner electrode having a catalytic action on at least one decomposed species of the first type gas, and a second outer electrode arranged outside the pipe so as to face the second inner electrode. Applying a second excitation voltage during the second step, generating a second atmospheric pressure plasma in the pipe, causing a chemical reaction including at least one decomposed species of the first type gas as a reactive species, Third different from gas
Generating a seed gas.

In accordance with yet another aspect of the present invention, a pipe formed of an electrical insulator and defining a gas flow path, an inner electrode disposed within the pipe and formed of foamed metal, Outside, a gas treatment device is provided having the inner electrode and an outer conductor arranged to face.

According to another aspect of the present invention, a pipe formed of an electrical insulator and defining a gas flow path, an inner electrode disposed in the pipe, and the inner electrode disposed outside the pipe. An outer conductor disposed so as to face, a first portion connected between the inner electrode and the outer electrode, the first portion having a pulse height for generating plasma, and maintaining the plasma following the first portion; And a pulse power supply for repeatedly generating a pulse signal having a second portion having a pulse height.

According to another aspect of the present invention, a pipe formed of an electrical insulator and defining a gas flow path, an inner electrode disposed in the pipe and formed of foam metal, A step of introducing a gas to be treated into the pipe using an outer conductor arranged so as to face the inner electrode, and applying an excitation voltage between the inner electrode and the outer electrode to form the pipe. Generating an atmospheric pressure plasma therein and passing a gas from the outside to the inside or from the inside to the outside of the inner electrode to cause a reaction to cause a reaction.

According to another aspect of the invention, a pipe formed of an electrical insulator and defining a gas flow path, an inner electrode disposed within the pipe, and the inner electrode disposed outside the pipe. Using an outer conductor arranged to face each other, a step of introducing a gas to be treated in the pipe, and a bipolar pulse train in which the polarity alternates between the inner electrode and the outer electrode; Applying an excitation voltage having a front portion having a first pulse height for generating plasma, and a rear portion having a second pulse height lower than the first pulse height and maintaining the generated plasma after the front portion. And generating a reaction by generating an atmospheric pressure plasma.

[0015]

FIG. 1A is a sectional view schematically showing a gas processing apparatus according to an embodiment of the present invention. The quartz tube 11 is a reaction vessel that defines a gas flow path. Although an insulating material other than quartz can be used, it is preferable to use quartz in terms of chemical stability, ease of cleaning, and the like. A gas inlet 12 is connected to one end of the reaction tube, and a gas outlet 13 is connected to the other end of the reaction tube. In the illustrated configuration, the gas inlet 12 and the gas outlet 13 are both the quartz tube 1
1 Both ends of the quartz tube 11 are
4 and 15 are hermetically sealed.

In the quartz tube 11, a first inner electrode 21 is disposed on the upstream side of the gas flow, and a second inner electrode 26 is disposed on the downstream side.
Is arranged. The inner electrodes 21 and 26 are made of Cu, A
It is a pipe or rod formed of a metal having a catalytic action such as u, Pt, Pd, Fe, Ni, or coated with these metals, and forms a predetermined gap with the inner wall of the quartz tube 11. These inner electrodes 21 and 26 are
Drawer portions 21t and 26 extending outside quartz tube 11
t. These drawer portions 21t and 26t are
It is not always necessary to have the same shape and material as the inner electrodes 21 and 26.

The inner electrodes 21 and 26 face the inner wall of the quartz tube 11 with a gap of about 1 mm. Outside the quartz tube 11, a first outer electrode 22 and a second outer electrode 27 made of a highly conductive metal are opposed to the inner electrodes 21 and 26.
Is arranged. These outer electrodes 22 and 27 are preferably wound in close contact with the quartz tube 11. Cu,
An adhesive tape of Al or the like can be used. Electrodes may be formed on the outer peripheral surface of the quartz tube by plating or sputtering.

An inner electrode 21 disposed in the quartz tube 11;
The open end of 26 is hermetically sealed by a sealing material 24. Note that the sealing member 24 may be a sealing member 24c common to the inner electrodes 21 and 26, and the inner electrodes 21 and 26 may be mechanically held. By configuring the outer surface of the sealing material 24c so as to be flush with the outer surfaces of the inner electrodes 21 and 26, it is possible to stabilize the gas flow.

The lead portion 21t of the inner electrode and the outer electrode 2
2, a first high-frequency high-frequency power supply 23 is connected. A second high-voltage high-frequency power supply 28 is connected between the lead portion 26t of the second inner electrode 26 and the second outer electrode 27.

From these power sources 23 and 28, both inner electrodes 2
By applying a high alternating voltage between the inner electrode 2 and the inner electrode 2 and between the inner electrode 2 and the outer electrode
Plasma is generated in a space facing the first and second substrates 26. The gas in the plasma is excited by the plasma and causes a chemical reaction to proceed under the catalytic action of the inner electrodes 21 and 26. As will be described later, both power supplies 23 and 28 generate a pulse train having a former part in which each pulse has a high pulse height and a latter part in which each pulse has a low pulse height. This pulse train alternates between positive and negative polarities, and is bipolar (alternating)
Construct a pulse train.

FIG. 2A schematically shows a gas flow in the gas processing apparatus shown in FIG. The gas introduced from the gas inlet 12 is supplied to the quartz tube 11 and the inner electrodes 21 and 26.
Flows toward the downstream side and is drawn out from the gas outlet 13.

By applying a high voltage between the inner electrodes 21, 26 and the outer electrodes 22, 27 (not shown), the plasma P1, P2 is applied to the space between the inner electrodes 21, 26 and the inner periphery of the quartz tube 11. Occurs. The gas introduced from the gas inlet 12 is decomposed by the plasma P1, and the plasma P2
Is converted into another gas and is derived from the gas outlet 13.

FIG. 2B schematically shows the waveform of the pulse voltage generated by the pulse power supplies 23 and 28. In the graph, the horizontal axis indicates time t, and the vertical axis indicates voltage V. The pulse train is a bipolar pulse train in which a positive polarity pulse PS1 and a negative polarity pulse PS2 are alternately generated. Each pulse has a pulse height V1, which has a voltage sufficient to generate a plasma,
It has a front with a duration t1 and a rear with a pulse height V2, duration t2, sufficient to maintain the generated plasma. The pulse height V1 is, for example, a voltage on the order of kV, and a pulse repetition frequency when a positive / negative pulse is a unit is a high frequency of kHz or more. For example, power supply 2
V1 for 3 is about 3 kV, and the frequency is 5 kHz or more.

As described above, once the plasma is generated, the power consumption can be reduced by reducing the voltage from V1 to V2. In addition, independent electrode pairs are provided in the gas flow direction of the reaction tube, upstream and downstream, and connected to separate power sources 23 and 28 to separately control the plasma P1 upstream of the reaction tube and the plasma P2 downstream. And both plasmas can be set to an optimum state.

As described above, the PACT gas processing apparatus is divided into a former stage and a latter stage, and the gas to be treated is decomposed in the former stage, and the synthesis reaction of the generated decomposed gas is performed in the latter stage, so that the desired recovered gas can be increased. It becomes possible to collect efficiently.

For example, when a gas to be treated containing CF ₄ and N ₂ is introduced into the gas inlet 12 and a gas containing NF ₃ is obtained from the gas outlet 13, the first plasma P 1 decomposes CF ₄ , And F are generated. The generated F radicals react with N _{2 in the} plasma P2 to form NF ₃ .

The gas inlet 12 has CF_FourProcessing target gas containing
And the WF₆Recover gas containing
In this case, the second inner electrode 26 is made of an alloy containing W as a main component.
Form. CF by the first plasma P1_FourIs decomposed,
Generates C and F radicals. In the second plasma P2, F
The radical chemically reacts with W in the second inner electrode 26, and WF
₆Occurs.

The first plasma P1 is used for decomposing the gas to be treated as described above. First inner electrode 21
The parameters (pulse height, duration, frequency) of the voltage pulse generated by the power supply 23 are set to be optimal for this purpose. In the second plasma P2, at least one kind of atom or atomic group generated by the decomposition is used for performing a desired synthesis reaction. The material of the second inner electrode 26 and the parameters (pulse height, duration, frequency) of the voltage pulse generated by the power supply 28 are set to be optimal for this purpose.

FIG. 1B is a cross-sectional view showing a modification of the gas processing apparatus shown in FIG. In the present modification, C generated in the plasma near the first inner electrode 21
The getter material 16 for adsorbing the like is arranged, and the second
The inner electrode 26 is formed of a foam metal pipe 26x. A metal wool 24w formed of the same metal as the second inner electrode 26x is accommodated in the open end of the foam metal pipe 26x. The extension 26y of the second inner electrode 26 constitutes a gas outlet.

The sealing material 2 shown in FIG.
4 or 24c may be used. In the vicinity of the second inner electrode 26x in the quartz tube 11, an auxiliary additive 17 for supplying, for example, a reactive species for a synthesis reaction is arranged.

For example, when a gas to be treated containing fluorocarbon is introduced from the gas inlet 12 to generate WF ₆ , a member for adsorbing C is disposed as the getter agent 16.
A metal containing W as a main component is disposed as the auxiliary additive 17.

The extension 26y of the second inner electrode is pipe-shaped, constitutes the gas outlet 13, and provides a support for the second inner electrode 26x made of foam metal.

FIG. 1C is a schematic plan view of the foam metal forming the second inner electrode 26x. The foam metal layer 29
It has a number of openings (through holes), allowing gas to pass across the membrane. For example, the aperture ratio is 90% or more. The material is, for example, Ni, Ni-Cu alloy, Cu, stainless steel (SUS316L) or the like. In addition, a noble metal such as Au, Pt, or Pd having a high catalytic action, or Fe or the like can be used.

FIG. 1D shows the second inner electrode 26x and the second inner electrode 26x.
An example of connection with the inner electrode lead-out part 26y is shown. The foamed metal layer 29 is wound around the outer periphery of the pipe-shaped second inner electrode lead-out portion 26y to form the second inner electrode 26x.

If the inner electrode is formed by winding the foamed metal film in this manner, the contact between the gas to be treated and the inner electrode having a catalytic action can be promoted, and the reaction can be promoted. is there. The number of turns of the foam metal layer is, for example, 3
, But can be arbitrarily increased or decreased.

FIG. 2C schematically shows a gas flow in the gas processing apparatus of FIG. 1B. In this modification, the second
The inner electrode is formed of a pipe of foam metal 26x.
Therefore, the gas output from the first plasma P1 is
While being affected by the plasma P2, the second inner electrode 26
x flows into the inside from outside and is drawn out from the gas outlet 13 formed by the lead portion 26y of the second inside electrode. When the gas to be treated is CF ₄ and the gas to be recovered is WF ₆ , a C adsorbent is disposed as the getter agent 16, and a material mainly containing W is disposed as the auxiliary additive 17.

CF ₄ is decomposed in the first plasma P 1,
When C is generated, the generated C is adsorbed on the getter agent 16. F radicals supplied from the first plasma P1 into the second plasma P2 react with W in the auxiliary additive 17,
WF ₆ is formed and collected from the gas outlet 13.

The getter agent 16, the auxiliary additive 17,
The inner electrodes formed of the foamed metal are independent of each other, and can be arbitrarily used in combination with other components.

In the above-described embodiment, the first and second inner electrodes and the first and second outer electrodes are independent of each other. Independent first plasma P1,
In order to generate the second plasma P2, mutually independent electrode pairs are required, but the inner electrodes 21, 26 and the outer electrodes 22, 27 need not all be independent.

FIGS. 3A and 3B show a configuration in which one of the first and second inner electrodes 21 and 26 and the first and second outer electrodes 22 and 27 is shared.

In FIG. 3A, the first and second inner electrodes are constituted by a common electrode 21c. For example, the inner electrode 21c is formed of a continuous metal pipe, and is connected to the ground potential. In FIG. 3B, the first and second
The outer electrodes 22, 27 are formed by a common outer electrode 22c and are connected to ground.

In both configurations, the power sources 23 and 28 are connected to independently held electrodes, respectively. More specifically, in FIG. 3A, the power sources 23 and 28 are connected to the outer electrodes 22 and 27, and in FIG.
Power supplies 23 and 28 are connected to the inner electrodes 21 and 26. As shown in FIG. 3B, when the inner electrodes 21 and 26 are independent and the coupling member 25 is used between them, the coupling member 25 is formed of an electrically insulating material.

FIGS. 4A and 4B show both inner electrodes 21,
A configuration example in the case where both are formed of a foamed metal layer is shown.
In FIG. 4A, the first inner electrode 21 is formed by winding a foam metal layer, and the second inner electrode 26 is formed by winding a foam metal similarly. Both inner electrodes 21,
26 is a coupling member 2 of an electrically insulating material which also serves as a sealing material.
5 are connected and supported.

The gas inlet 12 is connected to the extraction portion 2 of the first inner electrode.
It is constituted by a 1t pipe, and the gas outlet 13 is
It is constituted by a lead portion 26t of the inner electrode. The gas to be treated is introduced from the extraction portion 21t of the first inner electrode, passes through the inner electrode 21 of the foamed metal layer, and passes through the inner electrode 2.
After flowing out to the space between the quartz tube 11 and the inner surface of the quartz tube 11 and flowing downstream, it passes through the foamed metal layer of the second inner electrode 26 from the space between the quartz tube 11 and the second inner electrode 26. , Flows into the space inside the second inner electrode 26, and is led out from the gas outlet 13. The first inner electrode 21 and the second inner electrode 26 are mechanically coupled by an insulating coupling member 25, but are electrically independent. The first high-voltage, high-frequency power source 23 is the first
The second high-voltage, high-frequency power supply 28 is connected between the second inner electrode lead-out portion 26t and the second outer electrode 27.

FIG. 4B shows a case where the inner electrode coupling member 25 is formed of a conductor. The first inner electrode 21 and the second inner electrode 26 are connected by a conductive connecting member 25. However, the gas flow path is separated by a solid connecting member 25.

The gas to be treated introduced from the gas inlet 12 is led out of the first inner electrode 21 into the space between the first inner electrode 21 and the inner surface of the quartz tube 11 and flows downstream,
The gas is introduced into the second inner electrode 26 through the opening of the second inner electrode 26, and is led out from the gas outlet 13.

The first inner electrode 21 and the second inner electrode 26 are electrically connected commonly, for example, to a common ground potential. The first outer electrode 22 and the second outer electrode 27
Each is independently connected to the first power supply 23 and the second power supply 28.

With such a two-stage PACT gas processing apparatus, it becomes possible to decompose a gas to be treated and convert it into a desired gas to be regenerated.

In the above configuration example, the gas processing apparatus is divided into two stages, a former stage and a latter stage, and each of the former stage and the latter stage can set parameters according to the purpose. The present invention is not limited to the above embodiment.

The decomposition of the gas to be treated is not always achieved by a one-step chemical reaction, and the composition of the desired regeneration gas is not necessarily achieved by a one-step reaction. It may be desirable to perform the decomposition in a multi-step chemical reaction. It may be desirable to carry out the synthesis reaction in multiple stages of chemical reactions.

FIG. 5A shows an embodiment in which a gas to be processed is subjected to three or more stages of processing. Inside the quartz tube 11, a first inner electrode 21-1 and a second inner electrode 21-
2, the third inner electrode 21-3, the fourth inner electrode 21-4, ...
Are disposed on the outer side of the quartz tube 11 so as to correspond to the inner electrodes.
2-3, 22-4... Are arranged.

In the illustrated embodiment, each inner electrode 21
-1, 22-1, 22-3, 21-4,... Are connected by conductive connecting members 25-1, 25-2, 25-3, respectively. Among these connecting members, odd-numbered connecting members 25-1, 25-3,... Are solid connecting members, and are arranged so as to block the gas flow path in the inner electrode 21. Are arranged between the inner electrode 21 and the quartz tube 11, and the even-numbered connecting members 25-2, 25-4,.
The flow path between 1 and the inner surface of the quartz tube 11 is blocked.

The inner electrodes 21-1, 21-2, 21-3,.
Are electrically coupled by conductive coupling members 25-1, 25-2, 25-3,... And are commonly connected to the ground potential. Outer electrodes 22-1, 22-2, 22-3, ...
Are independent high-voltage high-frequency power supplies 23-1, 23-
, 23-3,... Are applied with a predetermined drive voltage.

As described above, by dividing the inside of the reaction tube into three or more reaction stages in the gas flow direction, the decomposition, the synthesis, or the reaction between the two is decomposed into a plurality of stages, and the applied voltage required for each reaction stage is reduced. They can be selected independently to carry out the desired reaction.

FIG. 5B shows another modification.
A gas inlet 12 is connected to an upstream end of the reaction tube 11,
A gas outlet 13 is connected to the downstream end, and a common inner electrode 12 is set inside the reaction tube 11. Reaction tube 11
On the outside, a first outer electrode 22-1 and a second outer electrode 22-
2, the third outer electrode 22-3, the fourth outer electrode 22-4,...
Is arranged. Each outer electrode has a power source 23-1, 2
3-2, 23-3, 23-4,... Are connected.

Further, an additional gas inlet 17-1 is formed in an intermediate region between the first outer electrode 23-1 and the second outer electrode 23-2, and the second outer electrode 23-2 and the third outer electrode 23- are formed.
A product gas extraction port 18 is connected to an intermediate portion of 3.
Further, an additional gas injection port 17-2 is connected between the third outer electrode 22-3 and the fourth outer electrode 22-4.

As described above, after the gas introduced from the gas inlet 12 is subjected to the desired chemical reaction in the first stage,
The additional gas is introduced from the additional gas inlet 17-1, a chemical reaction is further performed, and part of the generated gas is led out from the gas outlet 18. After the remaining product gas is further subjected to a plasma reaction, an additional gas is further introduced from the gas inlet 17-2, and the plasma reaction is performed.
3 is derived from the reaction gas. Although the configuration in which the product gas is derived in two stages has been described, the product gas may be derived in three or more stages. Although the configuration in which the additive gas is introduced in each stage has been described, the additive gas may not be introduced if unnecessary.

Although the embodiments in which electrodes are provided inside and outside the reaction tube and plasma is generated in the reaction tube have been described, the present invention is not limited to these embodiments.

FIG. 5C is a sectional view schematically showing another mechanism of plasma generation. The quartz reaction tube 31 has a portion whose diameter is enlarged in the middle, and has a rotating shaft portion 32 magnetized at that portion and a rotating blade 33 serving as an inner electrode set around the rotating shaft portion 32. A rotating magnetic field generating member 34 is set outside the quartz member 31. By generating a rotating magnetic field, the rotating wing 33 is rotated. Further, an outer electrode 35 is provided outside the quartz member 31, and a high-voltage power supply is connected between the outer electrode 35 and the rotating blade 33. By applying a high voltage, plasma is generated between the reaction tube 31 and the rotary wing member 33. As the rotor 33 rotates, the plasma expands in the circumferential direction in the reaction tube.

FIG. 6A is a schematic view showing a system in which the gas processing apparatus according to the above embodiment is connected to a semiconductor etching apparatus.

On the downstream side of the semiconductor etching apparatus 31,
The turbo pump 32 is connected, and a dry pump 33 is connected downstream of the turbo pump 32. N ₂ is introduced into the dry pump 33, and the exhaust gas is a gas containing the exhaust gas of the etching apparatus 31 and N ₂ . A gas decomposition regeneration device 35 is connected to the exhaust gas. The gas decomposition regeneration device 35 is further connected to a gas container 37 via a specific element recovery means 36 via a valve V.

For example, CF ₄ gas is supplied to the etching apparatus 31.
Used for etching inside. The gas used for etching is exhausted and introduced into a gas decomposition and regeneration device 35 via a turbo pump 32 and a dry pump 33. Here, according to the above-described embodiment, the gas containing CF ₄ gas and N ₂ is NF
Converted to ₃ gas or WF ₆ gas. Specific element recovery means 3
Numeral 6 is an optional constituent means for collecting, for example, gas species (C, Si,...) That can be deposited and reusing them. The gas that has passed through the specific element recovery means 36 is selectively recovered in the gas container 37 by the valve V.

FIG. 6B is a perspective view schematically showing a configuration example of the gas decomposition and regeneration apparatus 35 in FIG. 6A.
The gas introduced from the gas inlet 12 is branched into a plurality of reaction systems arranged in parallel, subjected to the above-described reaction processes by the respective reaction stages 35i, and is led out from the gas outlet 13. Thus, by connecting a plurality of reaction stages in parallel,
A large amount of gas can be processed at the same time.

Although the present invention has been described with reference to the embodiments, the present invention is not limited to these embodiments. For example, it will be apparent to those skilled in the art that various modifications, improvements, and combinations are possible.

The features of the present invention are described below.

(Supplementary Note 1) A pipe formed of an electrical insulator and defining a gas flow path, a first inner electrode disposed upstream in the pipe, and a first inner electrode outside the pipe. A first outer electrode disposed so as to face, a second inner electrode disposed in the pipe downstream from the first inner electrode, and disposed so as to face the second inner electrode outside the pipe; And a second outer electrode. (1) (Supplementary note 2) Further, an exhaust gas introduction unit connected to the upstream side of the pipe, a regeneration specific element recovery unit connected to the downstream side of the pipe, the first inner electrode and the first outer electrode. The gas processing apparatus according to claim 1, further comprising: a first high-voltage power supply connected to at least one of the first and second electrodes; and a second high-voltage power supply connected to at least one of the second inner electrode and the second outer electrode. (2) (Supplementary note 3) The gas processing apparatus according to claim 1 or 2, further comprising an inner electrode connecting member that mechanically connects the first inner electrode and the second inner electrode.

(Supplementary Note 4) The inner electrode connecting member is formed of an electrical insulator, and the first outer electrode and the second outer electrode are formed of two portions of a continuous conductor. The gas processing apparatus according to any one of the preceding claims.

(Supplementary Note 5) The inner electrode connecting member is formed of an electric conductor, and the first outer electrode and the second outer electrode are connected to the first high-voltage power supply and the second high-voltage power supply. The gas processing device according to claim 3.

(Supplementary note 6) The gas processing apparatus according to any one of claims 1 to 5, wherein at least one of the first inner electrode and the second inner electrode is formed of a foamed metal.

(Supplementary Note 7) The gas processing apparatus according to any one of claims 1 to 6, further comprising a getter material disposed near the first inner electrode in the pipe.

(Supplementary Note 8) Further, a third inner electrode disposed downstream of the second inner electrode in the pipe, and a third inner electrode disposed outside the pipe so as to face the third inner electrode. The gas processing apparatus according to claim 1, further comprising a third outer electrode. (3) (Supplementary Note 9) A pipe formed of an electrical insulator and defining a gas flow path, an inner electrode disposed in the pipe and formed of foamed metal, and an inner electrode formed outside the pipe. A gas processing device comprising: an outer conductor arranged to face each other. (Supplementary note 10) A pipe formed of an electrical insulator and defining a gas flow path, an inner electrode arranged in the pipe, and arranged outside the pipe to face the inner electrode. An outer conductor, a first portion connected between the inner electrode and the outer electrode and having a pulse height for generating plasma, and a pulse height for maintaining plasma following the first portion. And a pulse power supply for repeatedly generating a pulse signal having a second portion. (5) (Supplementary Note 11) (a) A process target gas including at least a first type gas and a second type gas is introduced under atmospheric pressure into a pipe formed of an electrical insulator and defining a gas flow path. And (b) a first inner electrode disposed upstream in the pipe and having a catalytic action on the gas to be treated, and disposed to face the first inner electrode outside the pipe. Applying a first excitation voltage to the first outer electrode, generating a first atmospheric pressure plasma in the pipe, and decomposing at least a first type gas in the gas to be processed;
(C) a second inner electrode disposed downstream of the first inner electrode in the pipe and catalyzing at least one decomposed species of the first gas, and a second inner electrode outside the pipe. A second excitation voltage is applied between the second outer electrode and the second outer electrode arranged to face the electrode, and a second excitation voltage is applied in the pipe.
Generating an atmospheric pressure plasma to cause a chemical reaction including at least one decomposed species of the first type gas as a reactive species to generate a third type gas different from the first type gas. . (6) (Supplementary note 12) The gas processing method according to claim 11, wherein the first inner electrode and the second inner electrode include at least one of Cu, Au, Pt, Pd, Fe, and Ni.

(Supplementary Note 13) The gas processing method according to claim 11 or 12, wherein the first type gas is fluorocarbon, the second type gas is nitrogen gas, and the third type gas is nitrogen fluoride.

(Supplementary Note 14) The first type gas is a fluorocarbon, the auxiliary additive provided downstream of the second inner electrode or the first inner electrode contains W, and the third type gas is WF ₆ . The gas treatment method according to claim 11.

(Supplementary note 15) The method according to any one of claims 12 to 14, further comprising disposing a C getter material in the pipe near the first inner electrode, and adsorbing the carbon generated in the step (b) to the C getter. 2. The gas processing method according to claim 1.

(Supplementary Note 16) The gas processing method according to claim 11 or 12, wherein the first type gas is a hydrocarbon, the second type gas is nitrogen oxide, and the third type gas contains alcohol.

(Supplementary Note 17) At least one of the first inner electrode and the second inner electrode is formed of a metal foam pipe, and at least one of the steps (b) and (c) is performed by connecting the metal foam pipe from the outside. 17. The gas processing method according to any one of claims 11 to 16, comprising passing a gas inward or from inside to outside. (7) (Supplementary note 18) a front part in which at least one of the first excitation voltage and the second excitation voltage is a bipolar pulse train whose polarity alternates, and each pulse has a first pulse height for generating plasma; 18. The gas processing method according to any one of claims 11 to 17, further comprising, after the front part, a rear part having a second pulse height lower than the first pulse height and maintaining generated plasma. (8) (Supplementary Note 19) A pipe formed of an electrical insulator and defining a gas flow path, an inner electrode disposed in the pipe and formed of a foamed metal, and an inner electrode formed outside the pipe. Using an outer conductor arranged so as to oppose, a step of introducing a gas to be treated into the pipe, and applying an excitation voltage between the inner electrode and the outer electrode to generate an atmospheric pressure plasma in the pipe. Generating a reaction and passing a gas from outside to inside or from inside to outside of the inner electrode to cause a reaction. (9) (Supplementary Note 20) A pipe formed of an electrical insulator and defining a gas flow path, an inner electrode disposed in the pipe, and disposed outside the pipe so as to face the inner electrode. A step of introducing a gas to be treated in the pipe, and a bipolar pulse train in which the polarity alternates between the inner electrode and the outer electrode, wherein each pulse generates a plasma. A front having one pulse height;
Applying an excitation voltage having a rear portion having a second pulse height lower than the first pulse height and maintaining the generated plasma after the front portion to generate an atmospheric pressure plasma to cause a reaction. Including gas treatment methods. (10)

[0077]

As described above, according to the present invention,
By processing the gas to be processed in a plurality of stages in the gas flow direction, the desired processing can be performed more reliably and more efficiently, and the desired regenerated gas can be recovered.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view schematically illustrating a gas processing apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic sectional view and a diagram for explaining a gas flow and an applied voltage in the gas processing apparatus shown in FIG.

FIG. 3 is a sectional view schematically showing a gas processing apparatus according to an embodiment of the present invention.

FIG. 4 is a sectional view schematically showing a gas processing apparatus according to an embodiment of the present invention.

FIG. 5 is a sectional view schematically showing a gas processing apparatus according to an embodiment of the present invention.

FIG. 6 is a block diagram schematically showing a gas processing apparatus according to an embodiment of the present invention, and a perspective view schematically showing a gas decomposition and regeneration apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Quartz tube 12 Gas inlet 13 Gas outlet 14, 15, 24 Sealing material 21, 26 Inner electrode 22, 27 Outer electrode 23, 28 Power supply 16 Getter 17 Auxiliary additive 26x Inner electrode of foam metal 26y Metal pipe 24w Metal wool 31 Etching device 32 Turbo pump 33 Dry pump 35 Gas decomposition regeneration device 36 Specific element recovery means 37 Gas container V valve

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[Procedure amendment]

[Submission Date] January 24, 2002 (2002.1.2
4)

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] Fig. 1

[Correction method] Change

[Correction contents]

FIG.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4D002 AA22 AC10 BA07 CA20 DA22 DA23 DA25 HA03 4G075 AA03 AA62 BA01 BA05 BD14 CA47 CA54 EB21 EB41 EC06 EC21 FB06 FC13

Claims (10)

[Claims] 1. A pipe formed of an electrical insulator and defining a gas flow path, a first inner electrode disposed on an upstream side in the pipe, and facing the first inner electrode outside the pipe. A first outer electrode, a second inner electrode disposed downstream of the first inner electrode in the pipe, and a second outer electrode disposed outside the pipe so as to face the second inner electrode. A gas processing device having a second outer electrode. 2. An exhaust gas introduction unit connected to an upstream side of the pipe, a regeneration specific element recovery unit connected to a downstream side of the pipe, and a first internal electrode and a first external electrode. The gas processing apparatus according to claim 1, further comprising a first high-voltage power supply connected to at least one of the first and second high-voltage power supplies, and a second high-voltage power supply connected to at least one of the second inner electrode and the second outer electrode. 3. A third inner electrode disposed downstream of the second inner electrode in the pipe, and a third inner electrode disposed outside the pipe and facing the third inner electrode. The gas processing apparatus according to claim 1, further comprising an outer electrode. 4. A pipe formed of an electrical insulator and defining a gas flow path, an inner electrode disposed in the pipe and formed of a foamed metal, and facing the inner electrode outside the pipe. Gas treatment device having an outer conductor arranged as described above. 5. A pipe formed of an electrical insulator and defining a gas flow path, an inner electrode disposed in the pipe, and an outer disposed outside the pipe so as to face the inner electrode. A conductor, a first portion connected between the inner electrode and the outer electrode and having a pulse height for generating plasma, and a first portion having a pulse height for maintaining plasma following the first portion. And a pulse power supply for repeatedly generating a pulse signal having two portions. 6. A step of introducing a gas to be treated containing at least a first type gas and a second type gas into a pipe formed of an electrical insulator and defining a gas flow path under atmospheric pressure. (B) a first inner electrode disposed upstream in the pipe and having a catalytic action on the gas to be treated, and a first inner electrode disposed outside the pipe and opposed to the first inner electrode. Applying a first excitation voltage to the outer electrode to generate a first atmospheric pressure plasma in the pipe to decompose at least a first type gas in the gas to be treated; A second inner electrode that is disposed downstream of the first inner electrode and has a catalytic action on at least one decomposed species of the first type gas, so as to face the second inner electrode outside the pipe. A second excitation voltage between the second outer electrode and the second outer electrode; It was applied, the second in the pipe
Generating an atmospheric pressure plasma to cause a chemical reaction including at least one decomposed species of the first type gas as a reactive species to generate a third type gas different from the first type gas. . 7. At least one of the first inner electrode and the second inner electrode is formed of a foam metal pipe, and at least one of the steps (b) and (c) moves the foam metal pipe from outside to inside. 7. The gas processing method according to claim 6, comprising passing a gas from inside to outside. 8. A front part in which at least one of said first excitation voltage and said second excitation voltage is a bipolar pulse train of alternating polarity, each pulse having a first pulse height for generating plasma, 8. The gas processing method according to claim 6, further comprising a rear portion having a second pulse height lower than the first pulse height and maintaining the generated plasma after the first portion. 9. A pipe formed of an electrical insulator and defining a gas flow path, an inner electrode disposed in the pipe and formed of foam metal, and facing the inner electrode outside the pipe. Introducing a gas to be treated into the pipe using an outer conductor arranged as described above, and applying an excitation voltage between the inner electrode and the outer electrode to generate an atmospheric pressure plasma in the pipe. And passing a gas from outside to inside or from inside to outside of the inner electrode to cause a reaction, thereby causing a reaction. 10. A pipe formed of an electrical insulator and defining a gas flow path, an inner electrode disposed in the pipe, and an outer electrode disposed outside the pipe and opposed to the inner electrode. A step of introducing a gas to be treated in the pipe using a conductor, and a bipolar pulse train in which the polarity alternates between the inner electrode and the outer electrode, wherein each pulse is a first pulse that generates plasma. Generating an atmospheric pressure plasma by applying an excitation voltage having a front portion having a height and a rear portion having a second pulse height lower than the first pulse height and maintaining the generated plasma after the front portion. Producing a reaction.