JPH0810576A - Removing method of harmful gas and device therefor - Google Patents

Abstract

PURPOSE:To provide a removing method of harmful gas containing NOX and the device easy to handle, compact and inexpensive and effective even in the atmosphere. CONSTITUTION:In the method for removing a harmful gas 3 containing NOX in a gas, the gas 12 is brought into contact with a photocatalyst carrier 8 carrying a photocatalyst on the surface of a light transmissive supporting body having a rugged surface under light irradiation 9, which may be performed from the rear of the light transmissive supporting body or may be performed in electric field.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a device for removing harmful gas in a gas, and more particularly to a method and a device for removing harmful gas containing NOx in the atmosphere and various gases. Next, the fields of application and uses of the present invention are shown. (1) Treatment of NOx, tobacco, musty odor, toilet odor, and various chemical odors at home, office, and hospital. (2) Treatment of exhaust gas such as NOx and SOx from various combustion equipment. (3) Exhaust gas treatment for automobiles in tunnels and highways. (4) Treatment of various harmful gases (eg, NOx, hydrocarbons) in and around clean rooms in the semiconductor industry, pharmaceutical industry, food industry, agriculture and forestry industry, medical care, precision machinery industry. (5) NOx (NO, NO ₂ , N ₂ O), SO in the atmosphere
Processing of x. (6) Emission gas (NOx, organic Cl compound) containing NOx due to stripping in a water treatment plant.

[0002]

2. Description of the Related Art The prior art will be explained by taking harmful gases such as NOx, SOx and tobacco odor in various industries and industries as an example. First of all, regarding the release of exhaust gas from various industries and industries and exhaust gas of automobiles into the atmosphere, legal and other regulatory measures have been taken from the viewpoint of pollution prevention, especially regarding nitrogen oxides and sulfur oxides, Its emission is severely restricted as a causative agent of acid rain and photochemical smog. Many methods have hitherto been proposed for treating nitrogen oxides (NOx) and sulfur oxides (SOx) in exhaust gas, which are subject to emission regulations, but there are various practical problems. For example, as a conventional exhaust gas denitration technology,
Reduction method by adding ammonia, reduction method using catalyst,
Radiation irradiation method and the like have been proposed.

Each of these conventional methods has the following problems. Reduction method by addition of ammonia: Denitration effect is low. Reduction method using a catalyst: When used continuously, the catalyst performance decreases. Since metals and precious metals are used as catalysts, it is necessary to review them from the viewpoint of resource saving. Susceptible to acidic substances in dust. Irradiation method: A large amount of secondary products such as ammonium nitrate and ammonium sulfate are produced, so it is necessary to treat the by-products separately. Moreover, since ammonia is added in any of these methods, ammonia that is not consumed in the denitration reaction is discharged as leak ammonia,
It causes secondary pollution. In addition, it is necessary to review it from the viewpoint of using ammonia and saving resources.

Further, once these harmful gases are released into the atmosphere, it is difficult to remove them, and a new method and apparatus capable of removing them even in the atmosphere are expected to appear. next,
The harmful gas containing NOx (including odorous gas) generated by smoking at home or office will be described. These substances are generally regarded as a so-called cigarette odor, and in recent years, the demand for collection and removal is particularly high because of their harmfulness (eg, carcinogenicity) as well as odor. For the collection and removal of these, there are proposals for methods and devices that use various types of removal materials such as those that use activated carbon and plant essential oils, but these removal materials all have insufficient performance and new methods.・ The appearance of devices is expected.

[0005]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, is easy to handle, is compact and inexpensive, and is effective even in the atmosphere, and a method for removing harmful gases containing NOx and its method. The purpose is to provide a device.

[0006]

In order to solve the above-mentioned problems, in the present invention, in a method of removing harmful gas containing NOx in a gas, the gas is provided with a light-transmissive support whose surface is uneven. The photocatalyst carrier having the photocatalyst carried on its surface is brought into contact with the photocatalyst carrier under light irradiation. In the removal method, the light irradiation is preferably performed from the back surface of the light transmissive support, and is also performed under an electric field. Further, in the present invention, in a device for removing harmful gas containing NOx in a gas, a photocatalyst carrier having a photocatalyst supported on the surface of a light-transmissive support having an uneven surface, and a photocatalyst carrier carrying light And a light source for irradiating. In the above device, the light source is installed in the central part of the device and is provided so that light can be emitted from the back surface of the light transmissive support.

Next, each structure of the present invention will be described in detail.
In the present invention, the irradiation light may be ultraviolet light and / or visible light, and may be sunlight or artificial light. The photocatalyst used in the present invention is used by supporting it on the surface of a light-transmissive support having an uneven (roughened) surface. By doing so, the reaction rate by the photocatalyst is significantly improved by irradiating the catalyst carrier with light. Here, the light irradiation is preferably performed by irradiating the photocatalyst coated on the surface of the support with the light introduced into the support, that is, the back surface of the coated catalyst. The reason why the action of the photocatalyst is effective is due to the following two effects. One is that in the present invention, the photoreactive area is further increased by the uneven support on the surface, as compared with the case of using the smooth surface support. The other is that the light is effectively absorbed by the semiconductor as a photocatalyst because it is scattered by the unevenness of the surface.

As the material of the light-transmissive support, any material having a large ultraviolet and / or visible light transmittance can be used, but particularly quartz glass, Pyrex glass, soda lime having excellent light resistance. A glass material such as glass can be preferably used. As the shape, a plate shape, a sheet shape, a curved surface shape, a column shape, a rod shape, a linear shape, a net shape, a lattice shape, a fiber shape, or the like can be used. The thickness or thickness of the light transmissive support is better as it is thinner or thinner, but in terms of strength, it is preferably 0.1 mm or more or φ0.1 mm or more. Also, there is no upper limit, but the thicker the
Further, the thicker the fiber, the lower the photoreaction efficiency per volume of fiber, but depending on the application, it can be used even at about 10 mm.

The method of roughening the surface of the light-transmitting support is not particularly limited, and chemical etching with an HF aqueous solution and physical shaving with an abrasive may be used. The dimension of the unevenness needs to be about 200 nm or more in order to scatter ultraviolet and / or visible light. However, if the irregularity size is too large, the reaction surface area becomes small, so the efficiency decreases, and as a result, the upper limit is preferably 0.1 mm. The type of photocatalyst supported on the uneven light-transmitting support can be selected in consideration of the types of target harmful gas and light source. Due to its high photocatalytic activity and chemical stability, the most widely used photocatalyst at present is TiO ₂ , which can be suitably used in the present invention. However, the photocatalyst used in the present invention is not limited to this, and any photocatalyst conventionally known as a photocatalyst can be used.

Usually, a semiconductor material is preferable because it is effective, easily available, and has good workability. From the viewpoint of effect and economy, Se, Ge, Si, Ti, Zn, Cu, Al,
Sn, Ga, In, P, As, Sb, C, Cd, S, T
e, Ni, Fe, Co, Ag, Mo, Sr, W, Cr,
One of Ba and Pb, or a compound, alloy or oxide of these is preferable, and these are used alone or in combination of two or more kinds. For example, the element is Si,
Ge, Se, as compounds AlP, AlAs, Ga
P, AlSb, GaAs, InP, GaSb, InA
s, InSb, CdS, CdSe, ZnS, MoS ₂ ,
WTe ₂ , Cr ₂ Te ₃ , MoTe, Cu ₂ S, W
S ₂ , oxides such as TiO ₂ , Bi ₂ O ₃ , CuO,
Cu ₂ O, ZnO, MoO ₃ , InO ₃ , Ag ₂ O, P
bO, SrTiO ₃ , BaTiO ₃ , Co ₃ O ₄ , Fe
₂ O ₃ , NiO and the like.

If the photocatalyst film is too thin, it cannot absorb light sufficiently. On the other hand, if it is too thick, the photocarriers generated in the film cannot diffuse to the surface, and the catalytic activity decreases. Therefore, the optimum value exists. The value varies depending on the type of photocatalyst used, but is in the range of several nm to several μm. It is effective to use the above-mentioned photocatalyst under an electric field. Electric field strength is 1V / cm
-10 kV / cm, usually 10 V / cm-1 kV / cm. The electric field can be set in the vicinity of the photocatalyst by setting an appropriate electrode material such as a linear shape, a net shape, a rod shape, or a lattice shape, and applying a voltage between the photocatalyst and the shape of the photocatalyst or electrode material. Preliminary tests can be conducted as appropriate to select appropriate conditions. The type and thickness of the photocatalyst, the presence or absence of an electric field, and their strength should be determined by conducting preliminary tests depending on the field of use, the type and concentration of the substance to be treated, the type of light source, the type and shape of the photocatalyst support, and the required performance. You can

Next, the light source will be described. The light source may be any one as long as it has a wavelength that excites the photocatalyst, and a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, a xenon lamp, or the like can be used, and sunlight can be appropriately used depending on the destination. The position of the light source can be appropriately selected depending on the application field, the type of light source, and the shape of the device. Usually, it is preferable to install a light source in the center of the reactor because all the light emitted radially from the light source can be effectively used. In addition, depending on the place of use, it can be used in combination with well-known harmful gas removing means as appropriate. Known means for removing harmful gases include activated carbon, activated carbon fiber, zeolite, ion exchange filters (fibers), organic polymer (organic polymer beads), and the like.

Means for using the complex oxide catalyst already proposed by the present inventors (Japanese Patent Application No. 4-332167,
Japanese Patent Application No. 4-357780, Japanese Patent Application No. 5-216859
No.) can be appropriately used depending on the field of use. As a method of using these, when the treated harmful gas is usually relatively high or the number of kinds of treated gas is large, the harmful gas is removed to some extent by these means in advance, and then removed by the means of the present invention. This makes it possible to highly efficiently treat a high-concentration gas to be treated and a complex harmful gas of a multi-component system, and effectively obtain a super-clean gas or space. The present invention is effective in treating NOx. NOx is the most stable of other harmful gases and is difficult to process by conventional methods. Since NOx can be easily treated by the present invention, NOx
Other harmful gases coexisting with, such as NH ₃ , organic Cl compounds, hydrocarbons, tobacco odors, musty odor components, etc. are easily treated.

[0014]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. Example 1 A basic configuration diagram of the harmful gas removing apparatus of the present invention is shown in FIG.
Air purification in a hospital will be described using this.
In FIG. 1, fine particles (particulate matter) and harmful gas (including odorous gas, such as aldehydes, ketones, pyridines, pyrroles, nitriles, nitrogen oxides, ammonia, etc.) resulting from smoking 2 etc. 3 has occurred.

The air cleaning is performed by a pretreatment filter 4, an electrostatic filter 5, an activated carbon 6, an ion exchange filter 7, and a photocatalyst carrier 8 carrying the photocatalyst of the present invention, ultraviolet rays, which are installed in the center of the side surface of the chamber. It is carried out by an air purifier 11 including a lamp 9 and a fan 10. The photocatalyst carrier 8 is
A large number of rod-shaped quartz glass with uneven surface
iO ₂ obtained by coating, ultraviolet rays from the ultraviolet lamp 9 through in the rod-like silica glass, the quartz glass surface T
It excites iO ₂ and activates it as a photocatalyst. Figure 1 (b)
FIG. 1A shows a sectional view taken along the line AA ′ of FIG. Reference numeral 12 represents a flow of contaminated air, and 13 represents clean air cleaned by the air cleaner 11.

In the air purifier 11, fine particles caused by smoking or the like are first removed by the pretreatment filter 4 to remove coarse particulate matter and then by the electrostatic filter 5 to remove remaining fine particles. On the other hand, harmful gas caused by smoking is firstly removed by the activated carbon 6 mainly neutral substances and acidic substances such as aldehydes and ketones. Next, an ion exchange filter (cation type) 7 removes mainly alkaline substances such as ammonia. As the ion exchange filter, those already proposed by the present inventors can be appropriately used. (For example, JP-A-63-12315 and JP-A-63-7.
7557, JP-A-63-97246, JP-A-2-5
Next, NOx that cannot be removed by these filters and the leaked harmful gas are removed by the photocatalyst. In the photocatalyst, NOx is mainly converted to nitric acid and fixed to be removed.

The nitric acid converted from NOx on the photocatalyst of the photocatalyst carrier 8 deteriorates the performance of the photocatalyst when it is operated for a long time, and may scatter rearward due to long-time operation. And / or a nitric acid collection filter (collection material), which is a product behind it, for example, if ion-exchange fibers (anion type), activated carbon, activated carbon fibers, or glass fibers are appropriately installed, the photocatalytic effect continues, And,
Since it can be collected even if it flows backward, it is preferable depending on the type of equipment, the concentration of treated harmful gas, the type of other harmful component removing material used, required performance, and the like. The above-mentioned collection filter can be installed by appropriately performing a preliminary test. The photocatalyst is suitable for treating a low concentration of harmful gas to an extremely low concentration or below the detection limit concentration. For this reason, it is possible to practically effectively perform the treatment by a well-known method such as this example in advance to a low concentration and the final treatment with a photocatalyst. Odor concentration (value of sensory test)
The air 12 containing a tobacco odor of 50 to 1,000 has an odor concentration of 10 or less, NOx as a harmful gas is 5 ppb or less, and NH ₃ is 10 ppb or less, and clean air 13 is obtained.

Embodiment 2 FIG. 2 shows a schematic configuration diagram of air cleaning using a removing apparatus of the present invention for removing a trace amount of harmful gas in a clean room in a semiconductor factory. In FIG. 2, class 1,000
NOx, NH ₃ and fine particles 22 are generated as harmful gases in the clean room 20 (having a particle number of 0.1 μm or more) by the work 21, and hydrocarbons (non-methane hydrocarbons) are 0 in the clean room air. .8-1.0p
pm exists. Since these pollutants (these gaseous pollutants and fine particles) pollute the raw materials, products and semi-finished products of the semiconductor factory, the air cleaning device 11 is installed to collect and remove the harmful gas and fine particles. It is being appreciated.

The apparatus 11 is mainly composed of a pretreatment filter 4, a fan 10, an ion exchange filter (cation type) 7 and a UL.
It is composed of PA filters _5-1 and _5-2 , a photocatalyst carrier 8 and an ultraviolet lamp 9. A cross-sectional view taken along the line BB ′ of FIG. 2A is shown in FIG. Air to be treated 12 containing harmful gas
The clean air that has been sucked and processed by the fan 10 is discharged in the direction of arrow 13. Each configuration will be described. The pretreatment filter 4 is a filter mainly made of glass fiber having a low air resistance, and first, coarse particles (particles having a relatively large particle size) in the suction air 12 are removed.

The ion exchange filter 7 is a filter for removing NH _{3 in} a clean room such as NH ₃ generated by the operation 21, and the one already proposed by the present inventors (the above) can be appropriately used. NH ₃ is 1
It is removed to 0 ppb or less. ULPA filter 5 _-1
Is a filter for removing particles such as particles generated in operation 21 in a clean room. As a result, the fine particles in the clean room of class 1,000, the fine particles generated by the operation 21 and the fine particles generated by the operation of the fan 10 are removed to the class 10 or lower.

The photocatalyst carrier 8 mainly removes NOx generated in the work 21 and decomposes hydrocarbons which causes an increase in contact angle. TiO ₂ is formed on a large number of fibrous quartz glass having an uneven surface. Is coated. Ultraviolet lamp 9 illuminates the TiO ₂ coated the inside of quartz glass coated with TiO ₂ as quartz glass surface, but to act as a photocatalyst. As a result, NOx in the clean room and NOx generated by the work 21
Are removed to 5 ppb or less. Also, the hydrocarbon is
It is converted to a stable shape that does not affect the increase in contact angle. UL
The PA filter _5-2 is a filter for removing fine particles generated from the photocatalyst and the vicinity thereof, and although it is usually unnecessary, it is installed to define an emergency.

As a result, clean air 13 having a NOx concentration of 5 ppb or less, a non-methane hydrocarbon of 0.2 ppm or less, an NH ₃ concentration of 10 ppb or less, and a fine particle concentration class of 10 or less can be obtained. When harmful gas is generated in the clean room, it adheres to the product or semi-finished product and increases the contact angle, resulting in a decrease in yield (reducing productivity). Therefore, it is necessary to keep the harmful gas below a certain concentration. Is important in the management of. The order of combining the photocatalyst and the known harmful gas removing means in the examples is not limited in any way and can be appropriately determined by conducting a preliminary test. The contact angle is an index showing the degree of contamination of the solid surface. When the solid surface is contaminated, the contact angle of water well reflects the state of contamination, and when the degree of contamination is large, the contact angle becomes large. Conversely, if the degree of contamination is small, the contact angle is small.

Example 3 FIG. 3 shows a schematic diagram of NOx removal in combination with lighting in a hotel lobby. This example is an example of use as an amenity. As shown in FIG.
There are two lighting fixtures 11 to brighten the vicinity. The main structure of the luminaire 11 is composed of an inner light source 9 and an outer glass, and the surface of the glass is an uneven surface and is a photocatalyst carrier 8 coated with TiO ₂ . NOx and SOx in the vicinity of the photocatalyst carrier are removed on the photocatalyst surface activated by the light source 9. 14 is a power cord.

Example 4 FIG. 4 shows a schematic view of removing a harmful gas by incorporating a photocatalyst on the wall surface of an expressway. In FIG. 4, on the highway 40,
NOx is emitted from the car 15 traveling at high speed. There is a wall surface 16 on the road 40, and a part of the wall surface is made of glass, and the surface of the glass is uneven and the photocatalyst carrier 8 is coated with TiO ₂ .

The photocatalyst carrier 8 is irradiated with sunlight 17 from its back surface and / or front surface to remove NOx. NOx is converted to nitric acid by a photocatalyst and adheres to the surface of the photocatalyst. However, due to occasional rainfall, the nitric acid is washed off from the photocatalyst and collected from the pit 18, and is separated into N ₂ by a well-known method by a water treatment device. Be reduced. 19 is
It is a pedestal that supports highways. The position of irradiation 17 of the photocatalyst by sunlight changes with the passage of time, but since the present catalyst is effective for both front irradiation and back irradiation, sunlight can be effectively used.

Example 5 The deodorizing effect and NOx removing performance using the air purifier of FIG. 1 are shown below. The volume of the waiting room 1 in which the air purifier was installed was about 30 m ³ , and the air flow rate inside the purifier was 100 liters / min. When 10 cigarettes were smoked at a position of about 1 m immediately below the pretreatment filter 4, cigarette smoke was visually recognized in the sample air collected at the position 12 immediately before the filter, and the odor concentration was evaluated by a sensory test (3-point comparison method). ) In 500
Met. Further, when NOx and NH ₃ were measured, they were 2 ppm and 2 ppm, respectively. The measuring method is a chemiluminescence method.

As the light-transmissive support, a smooth surface quartz rod (diameter 5.0 mm) having a polished surface was prepared, and the surface was roughened by polishing with sand. After adding 28.39 g of titanium (IV) propoxide to 18.43 g of absolute ethanol and stirring at room temperature for about 3 minutes,
It was ice-cooled (solution A). In addition, ethanol (18.4
A mixed aqueous solution of 3 g), water (1.8 g) and hydrochloric acid (0.29 g) was prepared (solution B). While stirring Solution A, Solution B was slowly added dropwise using a buret to obtain a homogeneous mixed solution (Solution C). After the quartz rod was immersed in the solution C, it was pulled up at a constant rate of 1.8 cm / min using a dipping device. After thoroughly drying in air, bake at 500 ° C for 10 minutes,
The photocatalyst carrier of the present invention was obtained. A schematic view of the obtained TiO ₂ -coated quartz rod, which is a photocatalyst carrier, is shown in FIG.

FIG. 5 is an explanatory view showing the action of the photocatalyst 39 of the present invention. A photocatalytic film 32 is carried on the surface of the light transmissive support A. The light 33 introduced from the light-transmissive support A is effectively absorbed by the photocatalyst film 32 by the action of the surface of the support A having irregularities. When the photocatalytic film 32 absorbs light having an energy larger than the width of the forbidden band, electrons are excited in the conduction band 34 and holes 37 are formed in the valence band 35. In this way, the holes 37 in the valence band 35 have an oxidizing power and the excited electrons 36 in the conduction band 34 have a reducing power. Reference numeral 38 denotes an object to be processed, which is decomposed by the force of the above action. The thickness of the coated TiO ₂ is 30 mm. The light source is
It is a high-pressure mercury lamp. Size of the performance test air purifier used: 50 x 50 x
60 cm

As a result, when this air was cleaned by operating the air purifier 11, the odor concentration of the air at the position 13 on the straight line of the outlet of the purifier 11 was 10 or less at the maximum in the sensory test. Further, here, no cigarette smoke was visually observed in the discharged air. The NOx and NH ₃ concentrations were 5 ppb or less, respectively.

Example 6 The activated carbon 6 and the ion exchange filter 7 were removed from the air purifier 11 shown in FIG. 1, and a tunnel ventilation exhaust gas containing NOx was introduced into the purifier at 50 liter / min.
The removal performance of Ox was examined with a chemiluminescence type NOx meter. NOx concentration: 1-3 ppm Air purifier size: 50 × 50 × 60 cm Photocatalyst and light source: the same as in Example 5. Result The NOx concentration at the outlet of the purifier was 10 to 30 ppb. As a comparative example, when the quartz rod was not roughened and was similarly coated with TiO ₂ , the NOx concentration at the outlet of the purifier was 0.3 to 0.5 ppm.

[0031]

EFFECTS OF THE INVENTION According to the present invention, the following effects are obtained by using the light-transmissive glass material having the uneven surface as the support of the photocatalyst. Since the support was uneven, the area of photoreaction (irradiation) was increased. Also, since light is scattered on the uneven surface,
It was effectively absorbed by the photocatalyst. As a result, the treatment efficiency of the harmful gas was improved, and the harmful gas was effectively treated. Since the support is a glass material, it is possible to directly irradiate the photocatalyst with ultraviolet light and / or visible light from the back surface of the photocatalyst without passing through the object to be treated, so that the structure of the treatment device can be more effectively used depending on the field of application. You can choose with great freedom.

For example, depending on the field of application, the photocatalyst may be external, the light source may be internal, or the photocatalyst may be internal, the light source may be external, or both may be combined at the same time. In addition, sunlight can also be appropriately used. That is, when irradiation is performed only from the conventional surface, when a solid substance or the like adheres to the photocatalyst surface over time, that portion becomes a dead space and the performance deteriorates. Further, in the conventional method, since the irradiation is performed through the treated product, the performance is affected by the treated product, and depending on the treated product, the treated product absorbs light, so that the light cannot be effectively used. Normally, NOx is a difficult substance to process, so NOx
If the treatment is performed by using as an index, other coexisting harmful deer can be treated at the same time, so that it is practically easy to control and manage. In the present invention, as described above, the performance can be stably maintained for a long time regardless of the processed material.

[Brief description of drawings]

1A is a basic configuration diagram of a harmful gas removing apparatus of the present invention used for air cleaning in a hospital, and FIG. 1B is a sectional view taken along the line AA ′ of FIG.

FIG. 2 (a) is a schematic configuration diagram of a removing apparatus of the present invention used in a clean room of a semiconductor factory, and FIG. 2 (b) is B of (a).
-B 'sectional view.

FIG. 3 is a schematic diagram in which the present invention is applied to lighting in a hotel lobby.

FIG. 4 is a schematic diagram in which the present invention is applied to a wall surface of a highway.

FIG. 5 is an explanatory view showing the action of the photocatalyst of the present invention.

[Explanation of symbols]

1: Hospital waiting room, 2: Tobacco, 3: Harmful gas, 4: Pretreatment filter, 5: Static filter, 5 _-1 , 5 _-2 : ULP
A filter, 6: activated carbon, 7: ion exchange filter,
8: photocatalyst carrier, 9: ultraviolet lamp, 10: fan,
11: Air purifier, 12: Contaminated air, 13: Clean air,
14: power cord, 15: automobile, 16: road wall surface, 1
7: sunlight, 18: pit, 19: stand, 20: clean room, 21: workbench, 22: contaminated gas, 30: hotel lobby, 31: uneven surface of support, 32: photocatalyst film, 3
3: Light, 34: Conduction band, 35: Valence band, 36: Excited electron, 37: Hole, 38: Harmful gas, 39: Photocatalyst carrier, 40: Road, A: Light transmissive support

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroaki Tada 3-5-11 Doshomachi, Chuo-ku, Osaka-shi, Osaka Inside Nippon Sheet Glass Co., Ltd.

Claims (5)

[Claims] 1. A method for removing harmful gas containing NOx in a gas, comprising: a photocatalyst carrier having the surface of a light-transmitting support having an uneven surface, the photocatalyst being carried by the gas.
A method for removing harmful gas, which comprises contacting under light irradiation. 2. The method for removing harmful gas according to claim 1, wherein the light irradiation is performed from the back surface of the light transmissive support. 3. The method for removing harmful gas according to claim 1, wherein the light irradiation is performed under an electric field. 4. A photocatalyst carrier in which a photocatalyst is carried on the surface of a light-transmitting support having an uneven surface in a device for removing harmful gas containing NOx in a gas, and light is applied to the photocatalyst carrier. A device for removing harmful gas, comprising: a light source for irradiating. 5. The light source is installed in the center of the device,
The harmful gas removing device according to claim 4, wherein the device is provided so that light can be irradiated from the back surface of the light transmissive support.