JP3829155B2 - Exhaust gas purification method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention can purify environmental pollutants represented by dioxins, etc., represented by dioxins, etc. in combustion exhaust gas discharged from incinerators at high temperatures by photocatalytic reaction, and can also be used for existing incinerators. The present invention relates to an exhaust gas purification method that can be mounted.
[0002]
[Prior art]
As an exhaust gas purification method for treating combustion exhaust gas discharged from an incinerator, conventionally, an dust collector, bag filter, or cyclone is provided in the combustion exhaust gas discharge path to remove dust in the combustion exhaust gas. There is also known a method of adsorbing and removing dioxins and the like in combustion exhaust gas by using an adsorbent such as activated carbon and activated coke.
[0003]
Japanese Patent Laid-Open No. 5-285342 discloses a photocatalyst mixed in combustion exhaust gas, introduced into an exhaust gas decomposition tower, irradiated with ultraviolet rays by a low-pressure mercury lamp in the exhaust gas decomposition tower, and collected by a dust collector following the exhaust gas decomposition tower. An apparatus for recovering the photocatalyst is disclosed.
[0004]
[Problems to be solved by the invention]
However, according to the purification method using the apparatus described in Japanese Patent Laid-Open No. 5-285342, the photocatalyst is mixed into the combustion exhaust gas, so that the transparency of the exhaust gas cannot be increased so much, and therefore compared with the light source. Although photocatalysts that are close to the target area can exhibit sufficient functions, photocatalysts that are some distance away from the light source are hardly irradiated with excitation light, and therefore cannot perform their functions sufficiently. There has been a drawback that the efficiency of exhaust gas treatment due to is significantly reduced.
[0005]
In addition, a dust collector is required to separate and recover the photocatalyst from the decomposed gas after the treatment, and there is a problem that the entire apparatus becomes complicated and expensive.
[0006]
On the other hand, in a purification method using an apparatus that collects and removes harmful substances such as dioxin in combustion exhaust gas by installing an electric dust collector, bag filter, or cyclone, among dioxins contained in combustion exhaust gas, Although what is contained in dust can be removed together with dust, there is a problem that dioxins adhering to very fine fly ash and gaseous dioxins having a low boiling point cannot be removed.
[0007]
Also, for example, when collecting and removing such harmful substances with a dust collector, the combustion exhaust gas discharged from the incinerator is hot, so it is necessary to use a cooling device to quickly cool it before introducing it into the dust collector. However, it was complicated and expensive as a whole. The same is true for devices that use bag filters or cyclones.
[0008]
Therefore, it has been proposed to introduce oxidative decomposition or reductive decomposition using a metal catalyst such as titanium, vanadium, or platinum as an auxiliary means. However, according to the oxidative decomposition or reductive decomposition method using a metal catalyst, since the effective temperature atmosphere is around 230 ° C. and is narrow, as described above, the combustion exhaust gas is rapidly cooled using a cooling device, and then a dust collector or a bug is used. Since it was introduced into a filter and cyclone, the temperature control of the combustion exhaust gas was extremely troublesome because it was necessary to reheat the cooled exhaust gas to a high temperature.
[0009]
In addition, although the above-described purification method using an adsorbent such as activated carbon or activated coke can theoretically remove gaseous dioxins having a low boiling point, secondary treatment of used waste adsorbent that adsorbs dioxins is necessary. If the combustion exhaust gas temperature is 150 ° C. or higher, dioxins absorbed at an angle may be desorbed and released, or the adsorption performance of the activated carbon may be reduced and the desired adsorption removal cannot be performed, Since the combustion exhaust gas temperature usually fluctuates, various problems such as dioxins that have been adsorbed desorbed and re-scattered into the combustion exhaust gas have become apparent at high temperatures.
[0010]
The present invention has been made in view of the above-described problems, and the object of the present invention is that it can be installed in an existing incinerator and is represented by, in particular, dioxin in combustion exhaust gas discharged from the incinerator. It is intended to provide a combustion exhaust gas purification method that can oxidize and decompose environmental pollutants at a high temperature with a photocatalyst and thereby purify them to such an extent that they can be released into the atmosphere.
[0011]
[Means for Solving the Problems]
Therefore, the gist of the means adopted by the invention described in each claim of the present application is as described in the appended claims.
By the way, the combustion exhaust gas purification method according to the invention described in each claim of the present application is carried out using an exhaust gas purification device to be described later. The exhaust gas purification device is intended to be anything that is connected to the combustion exhaust gas discharge passage of the incinerator, and the exhaust gas purification device incorporated as an essential component unit when constructing a new incinerator, and the existing incinerator Including both the exhaust gas purification device attached later to the combustion exhaust gas discharge path, and is detachably attached to the combustion exhaust gas discharge path, and is firmly fixed to the combustion exhaust gas discharge path. It does not matter even if it is.
[0012]
According to the combustion exhaust gas purification method according to the first aspect of the invention employing such a configuration, the combustion exhaust gas discharged from the incinerator is introduced into the cylinder containing the photocatalyst body, and the cylinder is inserted into the cylinder. Since the light source can be brought into contact with the accommodated photocatalyst body and the light source is arranged outside the cylinder, and the photocatalyst is accommodated inside the cylinder, the cylinder has ultraviolet transparency. It is possible to reliably irradiate the photocatalyst with the excitation light emitted from the light source, to efficiently photoexcite the photocatalyst, and to add the excitation action by the thermal excitation of titanium oxide to synergize them. it can. That is, even when the combustion exhaust gas is brought into contact with the photocatalyst without adjusting the temperature, for example, environmental pollutants such as dioxin contained in the combustion exhaust gas can be efficiently oxidatively decomposed (detoxified) and burned. The exhaust gas can be purified to such an extent that it can be released into the atmosphere.
[0013]
Also, unlike conventional purification methods using, for example, a dust collector, bag filter, cyclone, etc., the combustion exhaust gas discharged from the incinerator is rapidly cooled using a cooling device, or the cooled combustion exhaust gas is heated again. Since there is no need to increase the temperature, it is not necessary to control the temperature of the combustion exhaust gas, so that a cooling device for rapidly cooling the combustion exhaust gas and a reheating device for the cooled combustion exhaust gas are not required.
[0014]
Further, unlike a device that adsorbs with an adsorbent such as activated carbon or activated coke, secondary treatment of the used waste adsorbent becomes unnecessary.
[0015]
Furthermore, by embossing the cylindrical body and the reinforcing plate, it is possible to diffusely reflect the excitation light emitted from the light source, and in particular, it is possible to sufficiently irradiate the excitation light even to the photocatalyst away from the light source, The photocatalytic function can be fully exhibited.
[0016]
Furthermore, when configured as a double cylinder composed of an outer cylinder made of quartz glass and an inner cylinder made of quartz glass, a quartz glass reinforcing plate is interposed between the outer cylinder and the inner cylinder. By doing so, the strength of the cylinder can be increased and the cylinder can be enlarged, and a large amount of photocatalyst can be accommodated, and a light source that emits excitation light of the photocatalyst can be provided outside the cylinder. .
[0017]
In addition, according to the exhaust gas purification method of the present invention, the air supply pipe is connected in the vicinity of the connection portion between the combustion exhaust gas discharge path and the exhaust gas purification device, and air can be supplied to the center of the cylinder. In addition to the action obtained by the exhaust gas purifying apparatus, in particular, air (oxygen) can be sufficiently supplied to the photocatalyst at the center of the cylindrical body that tends to be deficient in oxygen. That is, sufficient oxygen can be brought into contact with the photocatalyst in the central part of the cylinder, and as described above, in the central part of the cylinder, reactive species having a high reactivity (superoxide ion (O2−) and water). Acid radicals (.OH)) are generated, and environmental pollutants in combustion exhaust gas can be oxidized and reduced (detoxified).
[0018]
In particular, according to the exhaust gas purification method of the present invention, the both ends of the exhaust gas purification device are connected to the combustion exhaust gas discharge passage of the combustion furnace, and the combustion exhaust gas is circulated through the exhaust gas purification device. In addition to the above action, even if there are environmental pollutants in the flue gas that could not be treated in the first pass, they can be reliably redox-degraded (detoxified), improving the overall decomposition efficiency. I can plan.
[0019]
According to the exhaust gas purifying apparatus according to the third aspect of the present invention, the light source is a combination of a germicidal lamp that emits ultraviolet light having a maximum wavelength near 254 nm and a black light that emits ultraviolet light having a maximum wavelength near 380 nm. Therefore, the surface of the photocatalyst can be excited by the ultraviolet rays emitted from the sterilizing lamp, and the ultraviolet rays emitted from the black light can pass through the photocatalyst to the inside of the cylinder. That is, in addition to the operation of the exhaust gas purifying apparatus according to the above claims, the photocatalyst body at the center of the cylinder can be sufficiently irradiated with excitation light, and the photocatalytic function can be exhibited.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail on the basis of an embodiment of the present invention. However, this is a representative one, and various design changes can be made without departing from the gist thereof. Shall.
[0021]
In the present invention, the photocatalyst 10 is obtained by supporting photocatalyst fine particles on the surface of a porous carrier, and examples of the porous carrier include nickel-cadmium, stainless steel, barmalloy, aluminum alloy, and copper. Examples of the porous metal and porous ceramics represented by activated carbon, activated alumina, silica gel, porous glass, etc., include activated carbon, from the viewpoint of a large surface area and cost compared to others. It is preferable to use porous ceramics such as activated alumina and silica gel as the carrier. The shape of the porous carrier may be any shape such as granular, plate-like, cylindrical, prismatic, conical, spherical, or rugby ball.
[0022]
The photocatalyst 15 is the excitation (photoexcitation) of electrons in the valence band when irradiated with light (excitation light) having energy (ie, short wavelength) larger than the energy gap between the conduction band and the valence band of the crystal. Is a substance that can generate electric conductors and holes, such as titanium oxide, tin oxide, zinc oxide, vanadium oxide, dibismuth trioxide, tungsten trioxide, ferric oxide, strontium titanate. Examples thereof include cadmium sulfide, and one or more of these can be used. Titanium oxide is preferably used in terms of exhibiting an excellent photocatalytic action as compared with other materials. In addition, as crystalline titanium oxide, there are anatase type, rutile type and brookite type, any of which can be used, but from the viewpoint of exhibiting the most excellent photocatalytic action, anatase type It is very preferable to use titanium oxide.
[0023]
By the way, when the photocatalyst 15 is irradiated with ultraviolet rays and photoexcited, an electron-hole pair is generated on the surface of the photocatalyst 15 as described above. Among them, electrons reduce surface oxygen to generate superoxide ions (O2−), and holes oxidize surface hydroxyl groups to generate hydroxyl radicals (.OH). These reactive species (superoxide ions (O2-) and hydroxyl radicals (.OH)) that are rich in reactivity can extremely efficiently and reliably treat redox degradation of environmental pollutants in combustion exhaust gas. (Can be detoxified).
[0024]
When the photocatalyst 10 used in the embodiment of the present invention is titanium oxide, for example, a titania sol obtained by suspending titanium oxide fine particles in water or a titania sol obtained by hydrolysis of an organic titanate, It is manufactured by coating the surface of the porous carrier described above by dip coating, dropping, spraying, or the like, followed by heating and baking.
[0025]
In addition, on the surface of the titanium oxide film covering the surface of the porous carrier, a metal film such as platinum, rhodium, ruthenium, palladium, iron, silver, copper, zinc, etc. It can be coated by a PVD method such as a vacuum vapor deposition method, whereby oxidative decomposition or reductive decomposition by the metal catalyst can be introduced as an auxiliary means.
[0026]
【Example】
The invention described in each claim can be embodied by using an exhaust gas purifying device 50 described later. A plurality of exhaust gas purification devices 50 are connected in series to form one set, which is connected to the combustion exhaust gas discharge passage 3, or a plurality of exhaust gas purification devices 50 are connected in parallel in a plurality of rows to form combustion exhaust gas as one set. A plurality of exhaust gas purification devices 50 connected in series are connected to the passage 3 and connected in parallel in a plurality of rows and connected to the combustion exhaust gas discharge passage 3 as a set. You can also.
[0027]
Further, the exhaust gas purification device 50 is intended for all of those connected to the combustion exhaust gas discharge passage 3 of the incinerator 1, and the exhaust gas purification device incorporated as an indispensable constituent unit when constructing the incinerator 1. Including both the apparatus and the exhaust gas purification device attached to the combustion exhaust gas discharge passage 3 of the existing incinerator, and is fixed to the combustion exhaust gas discharge passage 3 so as to be detachable. It may be the one that was made.
[0028]
Hereinafter, for convenience, the case where the exhaust gas purifying device 50 is used alone will be described as an example.
[0029]
FIG. 1 is a schematic view schematically showing a state when the exhaust gas purification device 50 of the first embodiment is connected to the combustion exhaust gas discharge passage 3 of the incinerator 1, and FIG. 2 is a partially broken view of the exhaust gas purification device 10. FIG. 3 is a perspective view of a main part of the exhaust gas purifying apparatus 50, and FIG. 4 is a cross-sectional view of a main part of the exhaust gas purifying apparatus 50.
[0030]
In the figure, the exhaust gas purifying device 50 has an ultraviolet ray transmissive cylinder 20 through which combustion exhaust gas discharged from the incinerator 1 passes, and a photocatalyst body that is accommodated in the cylinder 20 and contacts the combustion exhaust gas. 10 and a light source 40 that emits excitation light that is disposed outside the cylindrical body 20 and excites the photocatalyst 15. The entire light source 40 is assembled in the casing 30 and connected to the combustion exhaust gas discharge path 3 of the incinerator 1. It is configured to [0031]
The cylindrical body 20 is formed in a double shape including an outer cylinder 21 made of quartz glass and an inner cylinder 22 made of quartz glass, and a reinforcing plate 23 made of quartz glass is interposed between the outer cylinder 21 and the inner cylinder 22. Six photocatalysts 10 are provided, and both the space 22a inside the inner cylinder 22 and the space 24 between the outer cylinder 21 and the inner cylinder 22 are coated with a transparent silica gel surface with a photocatalyst (titanium oxide film). Is filled. The outer cylinder 21, the inner cylinder 22 and the reinforcing plate 23 are all embossed so that the excitation light emitted from the light source is diffusely reflected so that the photocatalyst 10a at the center of the cylinder 20 can be uniformly photoexcited. It has become. The cylindrical body 20 (the outer cylinder 21 and the inner cylinder 22) and the reinforcing plate 23 are formed using a transparent, ultraviolet transmissive and heat-resistant material, other than quartz glass. For example, it may be made of fused silica glass, hard glass, or translucent alumina.
[0032]
Further, as shown in FIG. 5, the inner cylinder 22 provided with the reinforcing plate 23a on the outer surface may be accommodated in the outer cylinder 21 and mounted, or as shown in FIG. Alternatively, the inner cylinder 22 ′ may be housed and mounted in the outer cylinder 21 ′ provided with the reinforcing plate 23b.
[0033]
A cap member A25 having a fitting hole 25a is hermetically crowned at the tip of the cylindrical body 20 via a heat-resistant endless ring 25b, and a gas in which the tip 26a is fitted in the fitting hole 25a. The introduction member 26 and the gas discharge member 27 whose tip end portion is fitted in the fitting hole 27a are in airtight communication so that the combustion exhaust gas does not leak to the outside. Each of the other ends of the gas introduction member 26 and the gas discharge member 27 is in series and airtight communication with the combustion exhaust gas discharge path 3 as a whole.
[0034]
Further, the gas introduction member 26 is provided with twelve air supply pipes 28 communicating spirally from the outside to the inside of the gas introduction member 26, and sufficient oxygen toward the central portion of the inner cylinder 22. Supply is now possible.
[0035]
The casing 30 has an inner peripheral wall 31 made of quartz glass and an outer peripheral wall 32 made of stainless steel. On the inner surface of the outer peripheral wall 32, there are six sterilization lamps 41 spaced apart at equal intervals, and between the sterilization lamps 41. A total of twelve black lights 42 each having an equal interval are provided. The cylindrical body 20 is accommodated in an internal space 31 a surrounded by the inner peripheral wall 31 of the casing 30. As the light source 40, in addition to the sterilization lamp 41 and the black light 42, a fluorescent lamp, an incandescent lamp, a mercury lamp, a UV light, a xenon lamp, a halogen lamp, a metal halide lamp, and the like can be used.
[0036]
A cap member B33 having a circular groove 33a is crowned on the gas introduction side front end of the inner peripheral wall 31 of the casing 30, and the front end portion of the inner peripheral wall 31 of the casing 30 is inserted into close contact with the circular groove 33a. The combustion exhaust gas is communicated in an airtight manner so as not to leak outside.
[0037]
And the cap member A25 provided in the cylindrical body 20 and the cap member B33 provided in the casing 30 are connected so as to prevent the combustion exhaust gas from leaking outside, and are connected via a heat-resistant O-ring 34, Thereby, the combustion exhaust gas introduced from the gas introduction member 26 is guided to the gas discharge member 27 through the inside of the cylindrical body 20.
[0038]
Further, the gas introduction side tip of the outer peripheral wall 32 of the casing 30 is provided with a lid member A35a inserted through the center portion and sealed around the gas introduction member 26, and also at the gas discharge side tip. A lid member B35b is provided in which the gas discharge member 27 is inserted and sealed around the center.
[0039]
In addition, it is preferable to provide a cooling water circulation path (not shown) for cooling the light source 40 outside the outer peripheral wall 32 of the casing 30 because the life of the light source 40 can be extended. Further, it is preferable that the entire cylindrical body 20 is configured like a Liebig cooling pipe (not shown), and the photocatalyst body 10 is washed with water once a month, for example.
[0040]
Since the exhaust gas purifying apparatus of the first embodiment is configured as described above, the combustion exhaust gas discharged from the incinerator 1 and guided to the combustion exhaust gas discharge passage 3 is transferred to the cylinder 20 via the gas introduction member 26. It can be introduced inside and can be discharged into the atmosphere via the gas discharge member 27.
[0041]
The combustion exhaust gas introduced into the cylindrical body 20 comes into contact with the titanium oxide film covering the surface of the photocatalyst body 10 filled in the cylindrical body 20. At this time, the photocatalyst (titanium oxide) 15 in the titanium oxide film is irradiated with ultraviolet rays (excitation light) emitted from the light source 40 outside the cylindrical body 20, the embossed inner cylinder 22, the outer cylinder 21, and the reinforcement. Since a sufficient amount of air (particularly oxygen) is mixed with the combustion exhaust gas through irradiation with ultraviolet rays (excitation light) diffused by the plate 23 and through the air supply pipe 28, titanium oxide is further added. As described above, active species rich in reactivity are generated, and the active species rich in reactivity generate combustion. The effect that the environmental pollutants in the exhaust gas can be rendered harmless by redox decomposition treatment very efficiently and quickly can be obtained.
[0042]
By the way, as schematically shown in FIG. 7, two exhaust gas purification devices 50 are assembled substantially in parallel with the combustion exhaust gas discharge passage 3, and the exhaust gas purification devices 50 are When the structure in which the blowing means (for example, the blower) 7 is assembled, the combustion exhaust gas can be circulated through the two exhaust gas purification devices 50. For example, a damper member for preventing backflow may be disposed on the side of the combustion exhaust gas discharge path 3 near the gas purification device 50 connection position (not shown). This is an embodiment corresponding to the invention described in claim 2. ,
[0043]
【The invention's effect】
As described above, according to the combustion exhaust gas purification method described in each claim of the present application, an effect that cannot be obtained by the conventional combustion exhaust gas treatment method can be obtained.
[0044]
(1) Unlike purification devices that use dust collectors, bag filters, cyclones, etc., the combustion exhaust gas discharged from the incinerator is rapidly cooled using a cooling device, or the cooled combustion exhaust gas is heated again to a high temperature Therefore, it is not necessary to control the temperature of the combustion exhaust gas, the entire incinerator can be simplified, and it can be retrofitted to the combustion exhaust gas discharge passage of the existing incinerator.
[0045]
(2) Unlike an apparatus that adsorbs with an adsorbent such as activated carbon or activated coke, secondary treatment of a used waste adsorbent that adsorbs dioxin, for example, becomes unnecessary.
[0046]
(3) Even if the photocatalyst is accommodated inside the cylinder and the light source is arranged outside the cylinder, the cylinder has ultraviolet transparency, so that the excitation light irradiated from the light source is converted into the photocatalyst. Can be reliably irradiated and photoexcited, and further, an excitation action by thermal excitation of titanium oxide can be added to synergize them, so that the combustion exhaust gas can be applied to the photocatalyst without adjusting the temperature, for example. Even when contacted, environmental pollutants, especially dioxins, contained in combustion exhaust gas can be efficiently oxidatively decomposed (detoxified) and purified to such an extent that combustion exhaust gas can be released into the atmosphere. it can.
[0047]
(4) Further, air (oxygen) can be sufficiently supplied to the photocatalyst in the central portion of the cylindrical body, which tends to be deficient by supplying air to the central portion of the cylindrical body, and sufficient oxygen can be brought into contact. In other words, reactive species (superoxide ions (O2-) and hydroxyl radicals (.OH)) rich in reactivity are generated in the center of the cylinder, so that the environmental pollutants in the combustion exhaust gas are oxidized and reduced. Can be made harmless.
[0048]
In particular, according to the exhaust gas purifying apparatus according to the second aspect of the present invention, the combustion exhaust gas can be circulated through the exhaust gas purifying apparatus, so that the overall decomposition processing efficiency can be improved and the environment that cannot be processed in the first pass. Even if there are pollutants, they can be reliably treated by redox decomposition and rendered harmless.
[0049]
According to the exhaust gas purification method of the third aspect of the present invention, it is possible to sufficiently irradiate the photocatalyst inside the cylindrical body, which tends to be short of the light amount away from the light source, and to sufficiently exhibit the photocatalytic function. Because it is possible, the purification action is improved.
[Brief description of the drawings]
FIG. 1 is a flowchart schematically showing a combustion exhaust gas purification method according to the present invention. The exhaust gas purification device is mounted in series with the combustion gas discharge path.
FIG. 2 is a partially broken perspective view of the exhaust gas purifying apparatus. Only a part of the photocatalyst is shown.
FIG. 3 is a longitudinal sectional view of a main part of the exhaust gas purifying apparatus. Only a part of the photocatalyst is shown.
FIG. 4 is a cross-sectional view of the main part of the exhaust gas purification apparatus. The light source is omitted.
FIG. 5 is an exploded perspective view of a main part shown for explaining a configuration of a cylindrical body. An inner cylinder having a reinforcing plate provided on the outer surface is accommodated and mounted inside the outer cylinder. The photocatalyst is not shown.
FIG. 6 is an exploded perspective view of an essential part for explaining the configuration of another cylindrical body. The inner cylinder is accommodated and mounted inside an outer cylinder provided with a reinforcing plate on the inner surface. The photocatalyst is not shown.
FIG. 7 is a flowchart schematically showing another embodiment of the exhaust gas purifying method according to the present invention. Two exhaust gas purification devices are mounted in parallel to the combustion gas discharge passage, and forced air blowing means (blowers) are incorporated in the vicinity of the exhaust ports of the exhaust gas purification devices.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Incinerator 3 ... Combustion exhaust gas discharge path 5 ... Discharge port 7 ... Forced ventilation means (blower)
DESCRIPTION OF SYMBOLS 10 ... Photocatalyst body 15 ... Photocatalyst 20 ... Cylindrical body 21 ... Outer cylinder 21 '... Outer cylinder 22 ... Inner cylinder 22' ... Inner cylinder 22a ... Space 23 ... Reinforcement plate 23a ... Reinforcement plate 23b ... Reinforcement plate 24 ... Space part 25 ... Cap member A
25a ... fitting hole 25b ... end wrestling 26 ... gas introduction member 26a ... tip 27 ... gas discharge member 27a ... fitting hole 28 ... pipe for air supply 30 ... casing 31 ... inner peripheral wall 31a ... inner space 32 ... outer peripheral wall 33 ... Cap member B
33a ... Circular groove 34 ... Heat-resistant O-ring 35a ... Lid member A
35b ... Lid member B
40 ... Light source 41 ... Sterilization lamp 42 ... Black light 50 ... Exhaust gas purification device

Claims (3)

The combustion exhaust gas discharge path of the incinerator contains a photocatalyst body in which a transparent silica gel surface is coated with a photocatalyst inside a cylinder having ultraviolet transparency, and the excitation light of the photocatalyst body is irradiated to the outside of the cylinder. The incinerator is connected to an exhaust gas purifying device having a light source, and the combustion exhaust gas discharged from the incinerator is introduced into the cylindrical body at a high temperature without adjusting the temperature and brought into contact with the photocatalyst body. An exhaust gas purification method for decomposing and removing environmental pollutants contained in combustion exhaust gas discharged from
An exhaust gas purification method, wherein air is supplied toward a central portion of the cylindrical body from an air supply pipe connected in the vicinity of a connection portion between the combustion exhaust gas discharge path and the exhaust gas purification device. The exhaust gas purification method according to claim 1, wherein both ends of the exhaust gas purification device are connected to the combustion exhaust gas discharge passage, and the combustion exhaust gas is circulated through the exhaust gas purification device. In the exhaust gas purification method,
The gas purification apparatus according to claim 1 or 2, wherein the light source that emits excitation light for exciting the photocatalyst is a combination of a sterilization lamp and black light.

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