JP2006167220A - Method and apparatus for treating gas containing tobacco smoke - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for efficiently treating volatile organic compounds and a tobacco odor in a treated gas containing tobacco smoke. <P>SOLUTION: In the treatment method, the treated gas containing cigarette smoke is treated with low-temperature plasma by silent discharges, and is treated by hopcalite catalyst subsequently. The treatment apparatus 50 has an inlet 51 for taking in the treated gas G<SB>1</SB>containing tobacco smoke, a low-temperature plasma treatment chamber 10 for treating the treated gas taken in from the inlet with the low-temperature plasma by silent discharge, a hopcalite catalyst treatment chamber 20 for treating the gas treated in the low-temperature plasma treatment chamber 10 with the hopcalite catalyst, and a discharge hole 52 for discharging the gas treated in the hopcalite catalyst treatment chamber. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for treating a gas containing tobacco smoke using a low-temperature plasma and a hopcalite catalyst, and an apparatus for treating the gas. ADVANTAGE OF THE INVENTION According to this invention, the volatile organic compound (VOC; volatile organic compound) in the gas containing tobacco smoke can be oxidized and decomposed | disassembled with high efficiency, and a tobacco odor can be made non-brominated with high efficiency.

  Examples of gas processing technology using low-temperature plasma and a metal oxide catalyst include, for example, discharge means for generating low-temperature plasma by discharge in a circulation space of a fluid to be processed, and a discharge field in the discharge means or downstream of the discharge field There is known a plasma catalytic reactor equipped with a catalyst means arranged in (Patent Document 1). According to this plasma catalytic reactor, ozone generated by low-temperature plasma and various active species (for example, radicals, excited oxygen molecules, excited nitrogen molecules, or excited water molecules) are increased by the action of the metal oxide catalyst. It reacts efficiently with harmful components and odor components in an active state to decompose and remove these substances. However, as a specific treatment object, only the treatment of nitrogen oxides in combustion exhaust gas, unburned fuel, or hydrocarbon, decomposition of dioxin, and further use for decomposition of CFCs are described. It does not describe the treatment of cigarette smoke-containing gases. Further, in the preferred catalyst used in the plasma catalytic reactor, the composition ratio of manganese oxide is 20% to 50%, and the composition ratio of other specific oxides is 80% to 50%. Is specifically used in combination with a composition ratio of manganese (30%), iron (60%), and cerium (10%). That is, there is no specific description of the combination of manganese dioxide and copper oxide, and there is no description of using a hopcalite catalyst containing manganese dioxide and copper oxide as main components.

  Further, as another gas processing technology using low-temperature plasma and a metal oxide catalyst, for example, a discharge electrode, a counter electrode having a surface portion facing the discharge electrode, and an adsorbent for adsorbing an oxidation catalyst and a harmful gas, There is known a gas decomposition apparatus in which an oxidation catalyst and an adsorbent are provided on a surface portion of a discharge electrode or a counter electrode, and a gas decomposition portion that generates a discharge is formed between the surface portion of the discharge electrode and the counter electrode. 2). According to this gas decomposition apparatus, in addition to decomposition of harmful gas by active species and electrons generated by discharge, it is possible to perform decomposition (oxidative decomposition) of harmful gas by an oxidation catalyst material. However, this gas decomposition method is a technique in which plasma treatment and oxidation catalyst treatment are used in combination, and is different from a technique in which an oxidation catalyst treatment is performed after the plasma treatment. Furthermore, specific treatment targets include harmful gases contained in the air, such as ammonia, acetaldehyde, acetic acid, and so-called toilet odor, kitchen odor, aging odor, and care odor. Only its use for decomposition and / or adsorption is disclosed, and no treatment of tobacco smoke-containing gas is described. Furthermore, it is introduced that iron oxide, nickel oxide, chromium oxide, zinc oxide, manganese dioxide, platinum, and palladium can be used alone or in combination as a mixture of plural kinds as suitable catalysts used in the gas decomposition apparatus. Has been. However, use of a hopcalite catalyst containing manganese dioxide and copper oxide as main components is not described.

  In addition, a technique for removing odorous components from gas fuel using a hopcalite catalyst is also known (Patent Document 3). The hopcalite catalyst is an oxidation catalyst made of manganese oxide, copper oxide, and other metal oxides (for example, potassium oxide, silver oxide, or cobalt oxide). Conventionally, it has not only a function of removing formaldehyde but also sulfurous acid. It is also known to have a purifying function for gas, hydrogen chloride, hydrogen sulfide, or nitrogen oxide and a function of oxidizing and removing carbon monoxide. However, Patent Document 3 does not describe processing of a gas containing tobacco smoke.

JP 2002-336653 A JP 2001-179040 A JP-A-8-24576

The present inventor has been diligently researching the development of technology for purifying gas containing tobacco smoke (specifically, tobacco odor or volatile organic compound contained in tobacco smoke) with high efficiency. Compared with the treatment with ozone and radicals generated by plasma and the treatment with manganese oxide catalyst in combination with the treatment of tobacco smoke-containing gas, or when the tobacco smoke-containing gas is treated with the hopcalite catalyst alone, It has been found that tobacco smoke can be treated with high efficiency by combining treatment with ozone and radicals generated by plasma and treatment with a hopcalite catalyst. Specifically, the present inventors have found that VOC contained in tobacco smoke is oxidized with high efficiency and the tobacco odor is also non-brominated.
The present invention is based on these findings.

Accordingly, the present invention relates to a gas processing method characterized in that a gas to be treated containing tobacco smoke is treated with a low-temperature plasma by silent discharge and subsequently treated with a hopcalite catalyst.
In the preferable processing method of this invention, the process by a dust collection means is included before the process by low temperature plasma.
In another preferable treatment method of the present invention, a treatment with a porous adsorbent is further included after the hopcalite catalyst treatment step.

Further, the present invention is processed in an intake port for taking in a gas to be processed containing tobacco smoke, a low temperature plasma processing chamber for processing the gas to be processed introduced from the intake port with a low temperature plasma by silent discharge, and the low temperature plasma processing chamber. The present invention relates to a processing apparatus for the gas to be processed, characterized in that it has a hopcalite catalyst processing chamber for processing the gas with a hopcalite catalyst and a discharge port for discharging the gas processed in the hopcalite catalyst processing chamber.
In the preferable processing apparatus of this invention, it has a dust collection means between an intake port and a low-temperature plasma processing chamber.
In another preferable processing apparatus of the present invention, a porous adsorbent processing chamber is provided between the hopcalite catalyst processing chamber and the discharge port.

According to the present invention, when the gas to be treated containing tobacco smoke is treated by low-temperature plasma by silent discharge, ozone and radicals (for example, oxygen radicals and OH radicals) are generated from the gas to be treated, and the tobacco in the gas to be treated. The odor and VOC are treated, and then the tobacco odor and VOC can be eliminated or reduced by treating the gas to be treated with a hopcalite catalyst.
In the present invention, before the low-temperature plasma treatment, the tobacco smoke-containing gas can be treated by dust collecting means, and by this dust collection treatment, tobacco smoke containing a relatively large amount of particulate harmful substances is contained. The particulate harmful substances can be effectively removed from the gas to be treated.
Further, in the present invention, after the hopcalite catalyst treatment, it can be further treated with a porous adsorbent. By this porous adsorbent treatment, the previous stage (that is, the low temperature plasma treatment and the hopcalite described above). It is also possible to adsorb oxidation intermediates that may occur in the catalyst treatment) to the porous adsorbent and to prevent the oxidation intermediates from being released to the outside.

  The to-be-processed gas processed with this invention method and this invention apparatus is a gas containing tobacco smoke. Specific examples of the gas containing tobacco smoke include air in a smoking room, a playground, a smoking vehicle, a restaurant, a hotel lobby, and the like. When actually processing the said to-be-processed gas by this invention, the intake which takes in a to-be-processed gas can be suitably provided in the ceiling, wall surface, and / or floor surface, such as a smoking room, for example.

  The method and the device of the present invention are suitable for treating a gas containing tobacco smoke, and in particular, remove or reduce tobacco odor and volatile organic compounds (VOC) contained in tobacco smoke. Suitable for Here, the volatile organic compound (VOC) contained in tobacco smoke is, for example, alcohols, ketones, aldehydes, pyridines, or aromatic compounds (for example, xylene, toluene, styrene, or benzene). is there.

In the present invention, any means for generating a low temperature plasma by silent discharge can be used. Silent discharge is more energy efficient in terms of ozone generation than corona discharge.
For example, the plasma processing chamber provided in the apparatus of the present invention has a position in which an electrode pair consisting of a ground electrode and a grounded electrode can be brought into contact with the gas to be processed inside a housing made of an insulator that can pass the gas to be processed. And having an insulator sandwiched between the electrode pair. In addition, the plasma processing chamber can generate plasma by so-called silent discharge, in which an alternating current is applied to the electrode pair sandwiching the insulator and discharged, and radicals and / or ozone can be generated. .

The said electrode used for plasma generation can be manufactured from arbitrary conductive materials, for example, aluminum or its alloy, copper, a carbonaceous material, iron or its alloy, or tungsten can be mentioned. When the electrode is in direct contact with the gas to be treated, it is preferable to use a metal having corrosion resistance and easy maintenance such as a cleaning operation or a replacement operation, such as stainless steel (for example, SUS304). .
Further, the shape of the electrode is not particularly limited, but a rod-shaped body (for example, a cylindrical body or a columnar body, particularly a cylindrical body or a columnar body), a plate-shaped body (for example, made of a conductive material). (A single-layered or multi-layered porous plate formed by punching a large number of holes in the plate), a stranded electrode manufactured by twisting a conductive wire, or a net-like body composed of fine conductive material fibers it can.

  Examples of the electrode pair include a pair of parallel cylindrical or columnar electrodes, a pair of coaxial cylindrical electrodes and bar electrodes, a pair of parallel plate electrodes, or a pair of cylindrical electrodes and plate electrodes. Can be mentioned. Further, for example, when the electrode gap is set to about 10 mm in the discharge using the parallel plate electrode pair, plasma can be generated between the electrodes by applying an alternating voltage of several tens kV to several tens kV between the electrodes.

  The insulator used for the silent discharge is not particularly limited as long as it can generate silent discharge when an alternating current is applied to the electrode pair. For example, glass, soot, resin, and ceramics Can be. Also, the shape of the insulator is not particularly limited as long as an silent current can be generated when an alternating current is applied to the electrode pair. For example, when the electrode is a core electrode, the core It can be a cylindrical insulating sheath surrounding the periphery of the electrode, and when the electrode is a flat electrode, it can be an insulating flat plate sandwiching the flat electrode from both sides.

The low-temperature plasma processing chamber that can be used in the apparatus of the present invention can include, for example, a large number of cylindrical electrodes divided into two groups that discharge each other inside the housing. In addition, the cylindrical electrode is
(1) (a) a protective electrode including a core electrode and a cylindrical insulating sheath surrounding the core electrode; and (b) a columnar exposed electrode whose electrode surface can be in direct contact with the gas to be processed; Or (2) a combination of only the protective electrodes. In the case of a combination of the protective electrode (a) and the exposed electrode (b), the protective electrode (a) is preferably a non-grounded electrode group and the exposed electrode (b) is preferably a grounded electrode group.

  The hopcalite catalyst used in the present invention is produced by, for example, solidifying a mixture of manganese oxide, copper oxide, and other metal oxides (for example, silver oxide and / or cobalt oxide) and drying or sintering the mixture. be able to. As the hopcalite catalyst, those having various compositions are known. For example, a catalyst comprising 60% by weight of manganese dioxide and 40% by weight of copper oxide, 50% by weight of manganese dioxide, 30% by weight of copper oxide and 15% of cobalt oxide. A catalyst composed of 5% by weight and 5% by weight of silver oxide is specifically known.

  The composition of the hopcalite catalyst used in the present invention is not particularly limited as long as it has an activity of converting carbon monoxide into carbon dioxide at room temperature in the presence of oxygen, but occupies the maximum content. Those containing manganese dioxide as the oxide are preferred. The content of manganese dioxide is preferably 50% by weight or more, more preferably 55% by weight or more, and most preferably 60% by weight or more. When the content of manganese dioxide in the hopcalite catalyst is less than 50% by weight, the treatment effect of the gas to be treated containing tobacco smoke may be insufficient, and when the content of manganese dioxide in the hopcalite catalyst is 60% by weight or more, A remarkably good treatment effect can be obtained. The shape of the hopcalite catalyst used in the present invention is not particularly limited, but in general, it can be used in the form of powder or granules, for example, about 1 to 3 mm.

  The hopcalite catalyst treatment chamber used in the apparatus of the present invention can include, for example, a metal plate carrying a hopcalite catalyst on the surface, for example, an aluminum plate carrying the hopcalite catalyst on the whole or a part of the surface. Further, it can be provided as a carrier having a structure (for example, honeycomb structure) in which the gas to be treated and the surface can be contacted with high efficiency. For example, the hopcalite catalyst can be electrodeposited on the whole or part of the metal plate surface, or an adhesive is applied to the whole or part of the metal plate surface, and then the powdered or granular hopcalite catalyst is sprinkled and fixed. It can also be made. In addition, it is preferable that at least a part of the surface of the powdered or granular hopcalite catalyst is exposed and in contact with the gas to be treated, and more preferably the largest possible surface is exposed. In addition, it is preferable that the said metal plate is a metal (for example, aluminum) which has the corrosion resistance of the grade which is hard to be corroded by the ozone and radical which are produced | generated in a plasma processing chamber.

  In the present invention, the hopcalite catalyst (particularly powdered or granular hopcalite catalyst) can be filled into the housing of the hopcalite catalyst treatment chamber. In this case, it is necessary to fill the particles of the powdered or granular hopcalite catalyst so that the gas to be treated can pass. In order to prevent the powdered or granular hopcalite catalyst from dropping out of the hopcalite catalyst treatment chamber, it is preferable to provide a drop prevention means such as a filter or a lid at the gas inlet and outlet.

  In the present invention, the position where the low temperature plasma processing chamber and the hopcalite catalyst processing chamber are installed can be introduced into the hopcalite catalyst processing chamber after the gas to be processed is processed in the low temperature plasma processing chamber, and the low temperature plasma processing There is no particular limitation as long as it can come into contact with the hopcalite catalyst in the hopcalite catalyst treatment chamber before the radicals and / or ozone generated in the above are decomposed. Therefore, for example, the gas outlet of the low temperature plasma processing chamber and the gas inlet of the hopcalite catalyst processing chamber are directly connected, or the gas outlet of the low temperature plasma processing chamber and the gas inlet of the hopcalite catalyst processing chamber are connected. Both can be connected by providing a transfer tube.

  In the present invention, the gas after being treated in the hopcalite catalyst treatment chamber can be discharged from the discharge port as it is, but can also be treated with a porous adsorbent before the release. The porous adsorption treatment chamber provided with the porous adsorbent has a gas inlet directly connected to a gas outlet of the hopcalite catalyst treatment chamber, or the hopcalite catalyst treatment chamber, the porous adsorption treatment chamber, It is also possible to connect them via a transfer pipe. In this porous adsorption treatment chamber, the VOC in tobacco smoke and the oxidation intermediate of tobacco odor that could not be completely oxidized by the low temperature plasma treatment and the hopcalite catalyst treatment can be adsorbed. In addition, although the said porous adsorbent is not specifically limited, For example, activated carbon, a zeolite, or sepiolite can be used. The gas thus treated can be discharged to the outside.

  In the present invention, before carrying out the low temperature plasma treatment of the gas to be treated, particulate matter (for example, VOC such as nicotine and tar) in the gas to be treated is removed by using the dust collecting means, and the dust collecting gas to be treated is collected. Can be treated with low temperature plasma. The particulate matter is not only difficult to remove by plasma treatment and hopcalite catalyst treatment, but also causes contamination of the inside of the plasma treatment chamber and the hopcalite catalyst treatment chamber. Therefore, by removing the particulate matter with the dust collecting means, it is possible to reduce the contamination inside the plasma processing chamber and the hopcalite catalyst device due to the particulate matter, so that the running cost for maintenance such as disassembly and cleaning is suppressed. be able to. The dust collecting means is not particularly limited, and for example, a high efficiency particulate air (HEPA) filter or an electric dust collector can be used. The dust collecting means and the low temperature plasma processing chamber directly connect the gas outlet of the dust collecting means and the gas inlet of the plasma processing chamber, or the gas outlet of the dust collecting means and the gas inlet of the plasma processing chamber. Both can be connected by providing a transfer pipe between them.

An embodiment of the processing apparatus of the present invention having a low-temperature plasma processing chamber and a hopcalite catalyst processing chamber will be described with reference to the accompanying drawings.
FIG. 1 is an explanatory view schematically showing a preferred embodiment of the device 50 of the present invention.
Gas processing device 50 of the present invention, the intake port 51 incorporated continuously or intermittently the gas to be treated G _1, and an outlet 52 for releasing the processed gas G _5, when processing the gas to be treated The low-temperature plasma processing chamber 10 and the hopcalite catalyst processing chamber 20 are included in this order along the flow direction. Between the low temperature plasma processing chamber 10 and the hopcalite catalyst processing chamber 20, a second transfer pipe 58 c for introducing the plasma processing gas G ₃ after the low temperature plasma processing into the hopcalite catalyst processing chamber 20 can be provided.

Furthermore, the gas processing apparatus 50 of the present invention can preferably include a dust collecting means 30 between the intake port 51 and the low temperature plasma processing chamber 10, and preferably, the hopcalite catalyst processing chamber 20 A porous adsorbent treatment chamber 40 may be provided between the discharge port 52 and the discharge port 52. When the dust collecting means 30 and the porous adsorbent processing chamber 40 are provided, an intake pipe 58 a for introducing the gas G ₁ to be treated into the dust collecting means 30 between the intake 51 and the dust collecting means 30. the provided between the dust collecting means 30 and the low-temperature plasma treatment chamber 10 of the, the first transfer pipe 58b for introducing a dust collection process gas G ₂ to a low temperature plasma treatment chamber 10 is provided, the hopcalite catalytic treatment chamber 20 and between the porous adsorbent treatment chamber 40 of the is provided with a third transfer tube 58d for introducing the hopcalite catalyst processing gas G ₄ to the porous adsorbent treatment chamber 40, and the porous adsorbent treatment chamber it can be provided discharge pipes 58e for releasing 40 and the processed gas G ₅ between the outlet 52 of the outside. A forced air supply fan 57 can be provided in the discharge pipe 58e.

In the gas processing apparatus 50 of the present invention, one or more of the intake pipe 58a, the first transfer pipe 58b, the second transfer pipe 58c, the third transfer pipe 58d, and the discharge pipe 58e are not provided. In addition, the members connected by these pipes can be directly connected. One such embodiment is shown in FIG.
Gas processing apparatus 50a of the present invention shown in FIG. 2, an intake pipe 58a for introducing the gas to be treated G ₁ to the dust collecting unit 30, the dust collection unit 30, low-temperature plasma treatment chamber 10, hopcalite catalytic treatment chamber 20, porous adsorbent treatment chamber 40, the porous discharge pipe 58e for discharging the treated gas G ₅ after treatment with adsorption treatment chamber to the outside, the forced air provided to the discharge pipe 58e fan 57, and the processed A gas discharge port 52 is provided.

In the gas processing apparatus 50 of the present invention shown in FIG. 1, instead of the forced air supply fan 57 provided in the discharge pipe 58 e or in addition to the forced air supply fan 57, If necessary, one or a plurality of forced air supply fans can be provided at any downstream position. In this specification, “downstream” and “upstream” refer to the gas to be processed G ₁ , the dust collection gas G ₂ , the plasma gas G ₃ , the hopcalite catalyst gas G ₄ , and the porous adsorbent gas G. ₅ means downstream and upstream with respect to the flow direction.

Processed gas G ₅ thus treated is discharged outside the apparatus through the discharge port 52 via the discharge pipe 58e by forced air fan 57 through the discharge pipe 58e. By the gas processing devices 50 and 50a, the gas to be processed can be processed batchwise or preferably continuously. In particular, in continuous processing, the amount of volatile organic compounds in the tobacco smoke-containing gas to be treated changes, so the intake 51, the intake pipe 58a, the first transfer pipe 58b, the second transfer pipe 58c, and the third transfer pipe. Various concentration sensors can be provided at 58d, the discharge pipe 58e, and / or the discharge port 52 to control the amount of gas to be processed and / or the applied voltage.

In the gas processing apparatus 50, 50 a of the present invention, the low temperature plasma processing chamber 10 generates a low temperature plasma by silent discharge and is processed by the gas to be processed G ₁ introduced from the inlet 51 or the dust collecting means 30. it is possible to use any means capable of processing the dust treated gas G _2. One mode is shown in FIG.
FIG. 3 is a schematic perspective view showing the low-temperature plasma processing chamber 10 that can be used in the gas processing apparatuses 50 and 50a of the present invention, with a part of the side wall of the housing 1 cut away. The low-temperature plasma treatment chamber 10 has a generally rectangular parallelepiped housing 1 having an outlet opening 3 for the inflow opening 2 and the plasma processing gas G ₃ dust collection gas G ₂ flows flows out A large number of cylindrical electrodes 6 are provided inside the housing 1. Further, the cylindrical electrode 6 is divided into two electrode groups 6A and 6B, and it is not necessary to ground these electrode groups, but it is preferable to ground one of them for safety of operation. When the cylindrical electrode 6 is divided into the non-ground side electrode group 6A and the ground side electrode group 6B, they are connected to the electric wires 9A and 9B, respectively, and the electric wires 9A and 9B are connected to the AC power source 9. The electric wire 9B connected to the ground side electrode group 6B is grounded. A high voltage is applied between the non-ground side electrode group 6A and the ground side electrode group 6B.

  FIG. 4 is a schematic cross-sectional view of the low-temperature plasma processing chamber 10 shown in FIG. A large number of protective electrodes 6 are provided inside the housing 1. As shown in FIG. 4, each protective electrode 6 includes a rod-shaped electrode 6x and a cylindrical sheath 6y surrounding the rod-shaped electrode 6x. The cylindrical sheath 6y is made of an insulating material. . Further, the protective electrode 6 is divided into two groups of electrode groups 6A and 6B, which are connected to the electric wires 9A and 9B, respectively, and the electric wires 9A and 9B are connected to the AC power source 9. Moreover, the electric wire 9B connected to the electrode group 6B of one series is grounded (earthed). The cylindrical protective electrode 6A side is not grounded, and the non-grounded electrode group 6H is formed, while the cylindrical protective electrode 6B side is grounded to form the grounded electrode group 6L.

Also, their non-grounded electrode group 6H and the ground-side electrodes 6L, respectively, constitute a group in a row in the housing 1, for each group (each column) is the direction of flow of the gas to be treated G ₁ Are arranged in parallel. That is, at the position (one end portion of the electrode group) facing the inner wall of the housing 1, the first group (row) of the ground side electrode group 6 </ b> L is in the flow direction of the gas G _{1 to} be processed. Are arranged in a parallel direction (thus, arranged in a direction parallel to the inner wall of the housing 1). Subsequently, the first group (column) of the non-ground side electrode group 6H is arranged in parallel with the first group (column) of the ground side electrode group 6L. The groups (rows) below the second group (rows) and the groups (rows) below the second group (rows) of the non-ground side electrode group 6H are alternately arranged in parallel and face the other inner wall of the housing 1. A group (column) of the ground-side electrode group 6L is arranged at a position (the other end of the electrode group) in contact with the non-ground-side electrode group 6H and the ground-side electrode group 6L. Silent discharge can occur and low temperature plasma can be generated.

  Note that the whole or a part of either one of the non-ground side electrode group 6H or the ground side electrode group 6L may be the exposed electrode. Here, the exposed electrode is an electrode in a form in which the cylindrical sheath of the protective electrode is removed and the rod-shaped electrode is exposed, and as the exposed electrode, in addition to the rod-shaped electrode, a cylindrical electrode or a columnar electrode It can also be.

In the gas processing apparatus 50,50a of the present invention, the hopcalite catalyst treatment chamber 20 includes a hopcalite catalyst, be in any form that the plasma processing gas G ₃ after low-temperature plasma treatment can be contacted with the hopcalite catalyst it can. One mode is shown in FIG.
FIG. 5 is a perspective view showing a part of the hopcalite catalyst processing chamber 20 that can be used in the gas processing apparatuses 50 and 50a of the present invention. The hopcalite catalytic treatment chamber 20 consists of a honeycomb structure of aluminum plates 22, each of the tubular passage, the outflow opening of the inlet opening 23 of the plasma processing gas G ₃ and hopcalite catalyst process gas G ₄ 24, and the granular hopcalite catalyst 21 is supported on the inner wall surface of the cylindrical passage of the aluminum plate 22. These granular hopcalite catalysts 21 can, for example, apply an adhesive to the entire surface of the aluminum plate 22 constituting the honeycomb structure, and then sprinkle and fix the granular hopcalite catalyst 21. since at least a portion of the surface of the granular hopcalite catalyst 21 is exposed, when each of the tubular passage has a plasma processing gas G ₃ passes, the plasma processing gas G ₃ is in direct contact with the hopcalite catalyst 21 Can do.

FIG. 6 is a schematic cross-sectional view showing another embodiment of a hopcalite catalyst treatment chamber that can be used in the gas treatment devices 50 and 50a of the present invention. A hopcalite catalyst treatment chamber 20a shown in FIG. 6 contains a large number of granular hopcalite catalysts 21 in a substantially rectangular parallelepiped housing 25. In this case, the inter-particulate granular hopcalite catalyst 21 is the plasma processing gas G ₃ is filled to allow passage. Further, as granular hopcalite catalyst 21 from the hopcalite catalyst treatment chamber 20a does not fall off, the filter 23a as a drop-off preventing means, 24a, the inflow opening 23 of the plasma processing gas G ₃ hopcalite catalyzed gas G ₄ Preferably, it is provided in the outflow opening 24.

In the gas processing apparatus 50,50a of the present invention, as the porous adsorbent treatment chamber 40, it may be any means capable of contacting the hopcalite catalyst processing gas G ₄ with the porous adsorbent. One mode thereof is schematically shown in FIG.
Porous adsorbent treatment chamber 7 40 hopcalite catalyzed gas G ₄ of the inlet opening 43 and the porous adsorbent treatment outflow opening 44 and generally rectangular housing 45 having a gas G ₅ The housing 45 is provided with granular activated carbon 41 as a porous adsorbent. The activated carbon 41 is packed so that the hopcalite catalyst treatment gas G ₄ can pass between the particles. Further, the porous adsorbent treatment chamber 40 as the granular activated carbon 41 from falling off, the filter 43a as a drop-off preventing means, 44a and the inflow opening 43 of the hopcalite catalyst processing gas G ₄ porous adsorbent treatment gas preferably provided on the outlet opening portion 44 of the G _5.

<Action>
In the present invention, the mechanism by which the activity of the hopcalite catalyst is improved by low-temperature plasma generated by silent discharge has not been found at present. However, some of the mechanisms by which the tobacco odor and volatile organic compounds in the tobacco smoke-containing gas are detoxified with unexpectedly high efficiency by the combined use of the low-temperature plasma and the hopcalite catalyst are estimated as follows. be able to. Note that the present invention is not limited to the following inference.
When a low temperature plasma is generated, not only an oxidation reaction occurs but also ozone is generated at the same time. Since ozone is reduced to oxygen molecules in the presence of a hopcalite catalyst, an oxidation reaction occurs simultaneously with the reduction reaction. Therefore, it is considered that the oxidation reaction acts on the tobacco odor or volatile organic compound in the treated gas containing tobacco smoke. However, since most of the action caused by the low-temperature plasma is considered to be caused by radical generation, the contribution of the oxidation reaction is considered to be only a part of the effect obtained by the present invention.

Further, it is known that a hopcalite catalyst exhibits a sufficient activity in a dry state, but deactivates when it contains moisture. However, in the present invention, the hopcalite catalyst is used in combination with the low temperature plasma treatment. Therefore, the dry state because the temperature of the discharge electrode portion of the low temperature plasma generation is increased, even if the humidity is relatively high in the gas to be treated, since the plasma processing gas G ₃ and hopcalite catalyst temperature is rising contact The deactivation of the hopcalite catalyst can be avoided.

Further, hopcalite catalyst used in the present invention has a ozone resolution, it is possible to reduce the ozone content of the hopcalite catalyst treatment gas G ₄ than ozone content in the plasma processing gas G _3. Furthermore, according to the present invention, dust (particulate contaminants) contained in the gas to be treated, which is difficult to be removed by the low temperature plasma treatment and the porous adsorbent treatment, can be treated by the dust collecting means. . Furthermore, the treatment of the porous adsorbent (for example, activated carbon) of the present invention results in the oxidation intermediate organic matter generated when the treatment of the volatile organic compound (VOC) and tobacco odor by the hopcalite catalyst treatment is insufficient. The compound can also be adsorbed with high efficiency.
Therefore, according to the present invention, the tobacco odor or the volatile organic compound in the tobacco smoke-containing gas can be treated with high efficiency.

  As described above, since the present invention exhibits an excellent treatment effect with respect to tobacco smoke-containing gas, it is suitable for, for example, preventing passive smoking in tobacco smoke-containing polluted air (for example, air inside a smoking room). Further, as described above, since the present invention can eliminate or reduce ozone in the treated gas, it is desirable to supply a harmless gas to the human body (for example, facilities used by many people). It can also be suitably applied to the air cleaner used in the above.

  EXAMPLES Hereinafter, the present invention will be specifically described by way of examples, but these do not limit the scope of the present invention.

Example 1
In this embodiment, a gas processing apparatus similar to the gas processing apparatus 50 shown in FIG. 1 is used, and the low temperature plasma processing chamber has a structure similar to that of the low temperature plasma processing chamber 10 shown in FIGS. A chamber was used. The low-temperature plasma processing chamber included 71 ground side cylindrical glass electrode groups and non-ground side cylindrical glass electrode groups in total, and the distance between the electrodes was 6.3 mm. The cylindrical glass electrode is composed of a rod-shaped aluminum core electrode (outer diameter = 1.5 mm) and a cylindrical glass sheath body (outer diameter = 4 mm), and the inside of the glass sheath body is filled with air. A protective electrode was used. In addition, a rectangular parallelepiped made of polyphenylene sulfide (PPS) (length = 280 mm; width = 260 mm; height = 11 mm) was used as the housing of the low-temperature plasma processing chamber. The generation of the low temperature plasma was performed under the conditions of an applied voltage of 8 kV, an air temperature of 22 ° C., and a humidity of 60%.

As the hopcalite catalyst treatment chamber, a hopcalite catalyst treatment chamber similar to the hopcalite catalyst treatment chamber 20 shown in FIG. 5 was used. The hopcalite catalyst treatment chamber has a honeycomb structure made of aluminum plates, and the hopcalite catalyst (manufactured by GL Sciences Inc .; average particle size = 2 mm; bulk density = 0.82 g / cm ³ ) is bonded to the aluminum plate. And fixedly supported on the surface. The hopcalite catalyst particles were supported on the surface of the aluminum plate at a density of about 0.17 g / cm ² . As the housing of the hopcalite catalyst treatment chamber, a rectangular parallelepiped made of stainless steel (SUS304) (length = 955 mm; width = 326 mm; height = 70 mm) was used.

  A HEPA filter was used as a dust collecting means provided between the intake port and the low temperature plasma processing chamber. In addition, as the porous adsorbent treatment chamber provided between the hopcalite catalyst treatment chamber and the discharge port, a treatment chamber containing about 3 kg of activated carbon was used.

  A gas to be treated in which four cigarettes are naturally combusted is introduced into a dust collecting means of the gas treatment device from an inlet serving as a gas to be treated supply means, followed by a low temperature plasma treatment chamber, a hopcalite catalyst treatment chamber, and a porous It processed in the order of the quality adsorbent processing chamber, and it was discharged outside from the discharge port by a forced air supply fan.

  The treatment capacity is determined by measuring the concentration of the volatile organic compound (VOC) contained in the gas to be treated and the concentration of VOC contained in the treated gas treated by the gas treatment device of the present invention. The removal rate of VOC by the gas processing apparatus of the invention was calculated.

  A gas sample to be processed for VOC measurement was collected at the inlet of the gas to be processed, and a porous adsorbent treatment gas sample as a processed gas was collected at the outlet. The measurement of the VOC concentration was carried out using a gas chromatograph mass spectrometer (manufactured by Hewlett-Packard; HP 6890) equipped with a gas concentrator (manufactured by Entec; Model 7000). Table 1 shows the measurement results of VOC and the VOC removal rate calculated from the measurement results.

Example 2
An experiment was conducted on an apparatus in which the dust collecting means and the porous adsorbent treatment chamber were removed from the apparatus used in Example 1.
Specifically, the dust collection means was removed, and the hopcalite catalyst treated gas was collected as a treated gas sample with a third transfer pipe, and VOC was measured. The results are shown in Table 1.

Example 3
An experiment was conducted on an apparatus in which the porous adsorbent treatment chamber was removed from the apparatus used in Example 1.
Specifically, when the hopcalite catalyst treated gas was collected as a treated gas sample with a third transfer tube and VOC was measured, the measurement results and removal rate were the same as in Example 2 (see Table 1). Is omitted).

<< Comparative Example 1 >>
An experiment was conducted on an apparatus in which the dust collecting means, the hopcalite catalyst treatment chamber, and the porous adsorbent treatment chamber were removed from the apparatus used in Example 1.
Specifically, the dust collecting means was removed, and a low temperature plasma treated sample was collected as a treated gas sample with a second transfer pipe, and VOC was measured. The results are shown in Table 1.

<< Comparative Example 2 >>
An experiment was conducted on an apparatus in which the dust collecting means, the low-temperature plasma processing chamber, and the porous adsorbent processing chamber were removed from the apparatus used in Example 1.
Specifically, the dust collecting means is removed, the voltage is not applied to the low temperature plasma processing chamber, the processing is performed in the absence of the low temperature plasma, and the hopcalite catalyst processing gas sample is processed as the processed gas sample. The VOC was measured. The results are shown in Table 1. In Table 1, “total concentration of VOC” includes components other than those shown in Table 1.

<Sensory test of tobacco odor>
The sensory test for cigarette odor was performed on tobacco-containing air in a smoking room provided inside a certain floor of an office building.
The smoking room used for the sensory test is a small room (about 18 m ³ ) that is isolated from the other part of the floor and has one entrance, and a gas inlet to be processed and a processing gas discharge port of the gas processing device, and a ventilation fan. And had. The smoking room was used by smokers (about 4 persons) in the floor in a normal usage pattern, and the apparatus of the present invention described in Example 1 was used as the gas treatment apparatus.
The sensory test consists of a non-operating period of the gas processing apparatus (a period of 5 consecutive days in which the operation of the gas processing apparatus is completely stopped and only the ventilation fan is operated) and an operating period (the gas processing apparatus is operated, Panelists (104 people mentioned; 33 smokers and 71 non-smokers) who entered the smoking room evaluated the cigarette odor in four steps, each for a period of five consecutive days when operation was suspended. Carried out. The evaluation results are shown in Table 2.

  According to the present invention, a harmful component (for example, a volatile organic compound) in a tobacco smoke-containing treatment gas is obtained by treating the tobacco smoke-containing treatment gas with a low-temperature plasma and subsequently performing a hopcalite catalyst treatment. Can be oxidized and made harmless with high efficiency, and the odor can be made non-brominated. Furthermore, ozone can be eliminated or reduced from the gas released.

It is explanatory drawing which shows the preferable aspect of this invention apparatus typically. It is explanatory drawing which shows another preferable aspect of this invention apparatus typically. It is a typical perspective view which cuts and shows a part of low-temperature plasma processing chamber 10 which can be used in this invention apparatus. It is typical sectional drawing of the low-temperature plasma processing chamber shown in FIG. It is a perspective view which cuts and shows a part of hopcalite catalyst processing chamber which can be used in this invention gas processing apparatus. It is typical sectional drawing which shows another aspect of the hopcalite catalyst processing chamber which can be used in this invention gas processing apparatus. It is typical sectional drawing which shows the aspect of the porous adsorbent processing chamber which can be used in this invention gas processing apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Housing; 1A, 1B ... Support wall; 2 ... Inflow opening part;
3 ... Outflow opening; 6 ... Cylindrical electrode (protective electrode); 6A ... Non-ground electrode group; 6B ... Ground electrode group; 6x ... Internal rod electrode; ..Cylindric sheath;
6H: Non-ground side electrode group; 6L: Ground side electrode group; 9 ... AC power supply;
9A: Ungrounded side wire; 9B: Grounded side wire; 10 ... Low temperature plasma treatment chamber;
20, 20a ... hopcalite catalyst treatment chamber; 21 ... hopcalite catalyst;
22 ... Aluminum plate; 23 ... Inflow opening; 24 ... Outflow opening;
23a, 24a ... filter; 25 ... housing; 30 ... dust collecting means;
40 ... porous adsorbent treatment chamber; 41 ... activated carbon; 43 ... inflow opening;
44 ... Outflow opening; 43a, 44a ... Filter; 45 ... Housing;
50, 50a ... gas processing device; 51 ... intake port; 52 ... discharge port 57 ... forced air supply fan; 58a ... intake pipe; 58b ... first transfer pipe;
58c ... second transfer pipe; 58d ... third transfer pipe; 58e ... discharge pipe;
G ₁ ... Processed gas; G ₂ ... Dust collection processing gas; G ₃ ... Plasma processing gas;
G ₄ · · · hopcalite catalyst treatment _{gas; G} 5 · · · porous adsorbent treatment gas (processed gas).

Claims (6)

  A gas treatment method comprising treating a gas to be treated containing tobacco smoke with low-temperature plasma by silent discharge, followed by treatment with a hopcalite catalyst.   The processing method of Claim 1 including the process processed by a dust collection means before the process processed with the said low temperature plasma.   The processing method according to claim 1, further comprising a step of treating with a porous adsorbent after the hopcalite catalyst treatment step.   An intake for taking in a gas to be treated containing tobacco smoke, a low-temperature plasma treatment chamber for treating the gas to be treated taken from the intake with a low-temperature plasma by silent discharge, and a gas treated in the low-temperature plasma treatment chamber with a hopcalite catalyst An apparatus for treating a gas to be treated, comprising: a hopcalite catalyst treatment chamber to be treated; and a discharge port for releasing a gas treated in the hopcalite catalyst treatment chamber.   The processing apparatus of Claim 4 which has a dust collection means between an intake port and a low-temperature plasma processing chamber.   The processing apparatus according to claim 4 or 5, further comprising a porous adsorbent processing chamber between the hopcalite catalyst processing chamber and the discharge port.

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