JP2000167352A - Method and apparatus for decomposing contaminated gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an environmentally friendly and efficient method and apparatus for decomposing halogenated aliphatic hydrocarbon compounds, lower in a possibility of generating a new environmental pollution due to decomposition. SOLUTION: This apparatus is equipped with a cathode 106 and an anode 105 respectively in two regions interconnected through a diaphragm 102. Acidic functional-water generated in the region of anode 105 by the electrolysis of water in which an electrolyte is dissolved is put into contact with gases containing halogenated aliphatic hydrocarbon compounds under light irradiation for decomposition treatment. Then, the gases exhausted from the acidic functional-water containing decomposed products after the light-irradiation treatment are put into contact with alkaline functional-water generated in the region of the cathode 106, resulting in trapping, by the alkaline functional-water, the chloride generated from the acidic functional-water in aeration.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for decomposing a halogenated aliphatic hydrocarbon compound and an apparatus used therefor.

[0002]

2. Description of the Related Art With the recent development of industrial technology, various halogenated aliphatic hydrocarbons have been used enormously, and their disposal has become a serious problem. In addition, various halogenated aliphatic hydrocarbons used have caused environmental problems such as polluting the natural environment, and great efforts have been made to solve them.

[0003] For example, as an example of a method for decomposing chlorinated aliphatic hydrocarbon compounds, there is a method of burning activated carbon or the like to which chlorinated aliphatic hydrocarbons are adsorbed.

As another example of the method for decomposing chlorinated aliphatic hydrocarbon compounds, there is a method using an oxidizing agent or a catalyst. Specifically, for example, a method for decomposing with ozone (JP-A-3-382)
No. 97), a method of wet oxidative decomposition under high temperature and high pressure, and a method of oxidative decomposition with hydrogen peroxide or iron salt (Japanese Patent Application Laid-Open No. 60-2).
No. 61590).

A method using sodium hypochlorite as an oxidizing agent has also been proposed (US Pat. No. 5,561,164).
No. 2). Also, a method of combining sodium hypochlorite with ultraviolet irradiation has been proposed (US Pat. No. 55
No. 82741).

[0006] A method is also known in which a photocatalyst comprising fine particles of an oxide semiconductor such as titanium oxide and a liquid chlorinated aliphatic hydrocarbon are suspended under alkaline conditions and decomposed by light irradiation (Japanese Patent Application Laid-Open No. 7-141373). ).

Further, as a method for decomposing chlorinated aliphatic compounds, a photodecomposition method of irradiating ultraviolet rays in a gas phase without using an oxidizing agent has already been attempted (Sekihiro et al .: "Present situation and countermeasures of groundwater and soil pollution"). Japan Society for Water Environment Kansai Chapter, Environmental Technology Research Association, 1995; Japanese Patent Application Laid-Open No. 8-243351).

[0008] It is known that chlorinated aliphatic hydrocarbons such as TCE and PCE are decomposed aerobically or anaerobically by microorganisms. Have been.

Further, examples of decomposing a fluorinated aliphatic hydrocarbon compound with a catalyst include, for example, JP-A-9-10554 and US Pat. No. 5,340,555.

Japanese Patent Application Laid-Open No. 8-141367 discloses a decomposition method in which a fuel such as alcohol or ether is mixed with Freon gas and burned in the presence of a catalyst.

US Pat. No. 5,393,394 discloses a method of decomposing fluorocarbon gas directly or by dissolving it in a solvent and irradiating it with ultraviolet rays.

JP-A-3-074507 describes a method in which chlorofluorocarbon is brought into contact with an electrode of an electrolytic cell to reductively decompose it. In the case of liquid Freon, it can be directly put into an electrolytic cell, and in the case of gaseous Freon, it can be dissolved in an electrolytic solution and subjected to electrolytic reduction on the cathode side for decomposition.

[0013] Combustion gas emitted from factories and garbage incineration plants contains many organic chlorine compounds including soot. Fine dust is a cause of respiratory illness, and benzpyrene and dioxin are strong. Because of its carcinogenic and mutagenic properties, purification of exhaust gas is a very important technical issue.

On the other hand, there have been proposed a number of purification devices for treating organic substances in exhaust gas by contacting them with a catalyst. For example, Japanese Patent Application Laid-Open No. 5-149127 discloses a method and apparatus for detoxifying harmful organic substances such as soot and dioxin in exhaust gas using an oxidation catalyst and a heating device therefor.

JP-A-6-246133 describes a method in which corona discharge is generated in exhaust gas to thermally decompose organic substances. In any case, particles such as low-molecular to high-molecular organic substances and soot can be decomposed and made harmless.

[0016] As a more economical method for purifying exhaust gas with a small environmental load, a processing method and apparatus using microorganisms have also been proposed. For example, U.S. Pat. No. 4,090,099 describes a method of removing and purifying soot and gaseous pollutants in exhaust gas by decomposing the microorganisms with microorganisms.

In US Pat. No. 5,494,574, a purification reaction vessel is filled with a filler in which microorganisms are immobilized.
It describes a method of circulating this in a reaction vessel and purifying contaminated water or gas containing harmful organic substances through the reaction vessel.

[0018]

The inventors of the present invention have examined various halogenated aliphatic hydrocarbon compounds and methods for decomposing exhaust gas as described above, and as a result, all of them have problems. Therefore, it was concluded that there was a need for a technique for decomposing the halogenated aliphatic hydrocarbon compound and the exhaust gas which was less problematic and environmentally friendly.

The present invention has been made based on new findings by the present inventors, and has as its object the purpose of being more environmentally friendly and having a lower possibility of causing new environmental pollution by decomposition. An object of the present invention is to provide an efficient method for decomposing a hydrogen compound and an apparatus used for the method.

Another object of the present invention is to provide a method for purifying exhaust gas containing a halogenated aliphatic hydrocarbon compound more efficiently, and an apparatus used for the method.

[0021]

Investigations were carried out with the aim of achieving the above-mentioned problems.
180293) and functional water obtained by electrolysis of water, which is reported to have a cleaning effect of contaminants on a semiconductor wafer (Japanese Patent Application Laid-Open No. 7-51675), for example, acidic water, under light irradiation. New knowledge was obtained that it has excellent resolution of halogenated aliphatic hydrocarbon compounds.

After that, a more practical form was examined, and as the detailed experiments proceeded, the halogenated aliphatic hydrocarbon was formed by the acidic functional water obtained by the electrolysis of water through the above-mentioned diaphragm. The present inventors have found out that it is desirable that the gas after the decomposition treatment of the contaminant gas containing the compound is brought into contact with alkaline functional water obtained by electrolysis of water through a diaphragm or the like, leading to the present invention.

That is, in the method for decomposing a halogenated aliphatic hydrocarbon compound according to one embodiment of the present invention, a cathode and an anode are disposed in each of two regions communicating with each other through a diaphragm, and the anode side is subjected to electrolysis. A method for decomposing a halogenated aliphatic hydrocarbon compound, comprising the step of contacting, under light irradiation, acidic functional water generated in the step (b) and a gas containing a halogenated aliphatic hydrocarbon compound, wherein the decomposition after the light irradiation treatment is performed. Halogenated aliphatic hydrocarbon compounds characterized by neutralizing acidic components, forming salts and removing acidic components by contacting gas discharged from acidic functional water containing products with alkaline functional water generated on the cathode side Is a decomposition method.

Further, the step of bringing the gas separated from the acidic functional water containing the decomposition product after the light irradiation treatment into contact with the alkaline functional water generated on the cathode side is performed by ventilation.
It is a decomposition method.

Also, two regions communicating with each other via a diaphragm, a pair of electrodes serving as a cathode and an anode disposed respectively, and
A container provided with a power supply for applying a potential to the electrode, a unit for supplying water in which an electrolyte is dissolved to the container, a unit for irradiating the container with light, and a gas containing a halogenated aliphatic hydrocarbon compound as an anode of the electrode. In the apparatus for decomposing a halogenated aliphatic hydrocarbon compound having a means for supplying to the side, gas discharged from acidic functional water containing decomposition products after the light irradiation treatment on the anode side of the electrode is generated on the cathode side. A device for decomposing a halogenated aliphatic hydrocarbon compound, comprising: means for contacting the functionalized alkaline water.

In another embodiment of the apparatus for decomposing a halogenated aliphatic hydrocarbon compound, a decomposition treatment tank and a cathode and an anode are disposed in two regions communicating with each other through a diaphragm, respectively. For supplying acidic functional water generated on the anode side by the electrolysis of water to the decomposition treatment tank, means for supplying a gas containing a halogenated aliphatic hydrocarbon compound to be decomposed to the decomposition treatment tank, and A device for decomposing a halogenated aliphatic hydrocarbon compound having means for irradiating a treatment tank with light, comprising means for bringing exhaust gas from the decomposition treatment tank into contact with alkaline functional water generated on the cathode side by electrolysis of the water. An apparatus for decomposing a halogenated aliphatic hydrocarbon compound.

[0027] Further, there is provided a purification method or apparatus wherein the halogenated aliphatic hydrocarbon compound is contained in exhaust gas.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION A method for decomposing a halogenated aliphatic hydrocarbon compound according to one embodiment of the present invention comprises the steps of:
Specifically, for example, a pH of 1.0 or more and 4.0 or less, more preferably 2. 0, which is formed on the anode side by electrolysis through a diaphragm.
The oxidation-reduction potential when the platinum electrode is the working electrode and the silver-silver chloride electrode is the reference electrode is 800 m or more.
V or more and 1500 mV or less, more preferably 1000 mV
Not less than 1300 mV and chlorine concentration of not less than 5 mg / L and not more than 15
0 mg / L or less, more preferably 30 mg / L or more and 120 mg / L
After the following functional water and a gas containing a halogenated aliphatic hydrocarbon compound to be decomposed are brought into contact with each other under light irradiation to perform a decomposition reaction, the treated gas is electrolyzed through a diaphragm to a cathode side. And a step of bringing into contact with the generated alkaline functional water.

By contacting acidic functional water with a gas containing a halogenated aliphatic hydrocarbon compound under light irradiation, the halogenated aliphatic hydrocarbon compound is decomposed, but the acidic functional water and the halogenated aliphatic hydrocarbon are decomposed. When the gas containing the compound is brought into contact with the gas, chlorine dissolved in the acidic functional water is discharged into the gas. In particular, this tendency becomes remarkable when a gas containing a halogenated aliphatic hydrocarbon compound is brought into contact with the acidic functional water by aeration. Therefore, chlorine odor is recognized in the exhausted gas.

The exhausted gas is not released to the atmosphere as it is, but is brought into contact with the alkaline functional water generated on the cathode side when the acidic functional water is generated. As a result, chlorine forms a salt in the alkaline functional water, and the chlorine is removed, thereby realizing a more environmentally friendly purification system. That is, chlorine is not detected in the gas discharged from the alkaline functional water, and the chlorine odor is naturally removed.

The gas after the decomposition reaction may be brought into contact with the alkaline functional water by any method.
A known method such as a shower can be used.

The acidic functional water used for the decomposition includes, for example, a hydrogen ion concentration (pH value) of 1 to 4 and a redox potential of 800 mV to 1500 mV when the working electrode is a platinum electrode and the reference electrode is silver-silver chloride. Hereafter, it refers to water having properties of chlorine concentration of 5 mg / L or more and 150 mg / L or less.

Such functional water is obtained by dissolving an electrolyte (eg, sodium chloride, potassium chloride, etc.) in raw water, and subjecting this water to electrolysis in a water tank having a pair of electrodes on which a diaphragm is disposed, so that the vicinity of the anode is obtained. Can be obtained at Here, the concentration of the electrolyte in the raw water before the electrolysis is, for example, 20 mg / L to 2000 mg / L for sodium chloride, and more preferably 200 mg / L to 1000 mg / L,
The electrolytic current value at that time is desirably 2A to 20A.

At this time, alkaline water or alkaline functional water is simultaneously generated on the cathode side. This alkaline functional water is used for removing chlorine. As the diaphragm, for example, an ion exchange membrane is preferably used. As means for obtaining such functional water, a commercially available strongly acidic electrolyzed water generator
(For example, trade name: Oasis Bio Half; manufactured by Asahi Glass Engineering Co., Ltd., trade name: strong electrolyzed water generator (Model
FW-200; manufactured by Amano Co., Ltd.).

The halogenated aliphatic hydrocarbon compound to be decomposed is not particularly limited as long as the acidic functional water undergoes a decomposition reaction under irradiation with light. For example, halogenated aliphatic hydrocarbon compounds may be used. Examples include an aliphatic hydrocarbon compound substituted with at least one of a chlorine atom and a fluorine atom.

Specifically, for example, a 1 to 4 chlorine-substituted product of methane, a 1 to 6 chlorine-substituted product of ethane, a 1 to 4 chlorine substituted product of ethylene, a 1 to 2 chlorine substituted product of acetylene, a 1 to 4 chlorine substituted product of propane
8-chlorine-substituted product, 1-6 chlorine-substituted product of propylene, allene
1 to 4 chlorine-substituted products of (propadiene), 1 to 4 chlorine-substituted products of arylene (methylacetylene), 1 to 10 chlorine-substituted products of butane, 1 to 8 chlorine-substituted products of 1-, 2-, or iso-butene , 1,
3-butadiene substituted with 1 to 6 chlorine, etc.), trichlorofluoromethane (CFC-11), dichlorodifluoromethane
(CFC-12), chlorotrifluoromethane (CFC-1)
3), bromotrifluoromethane (CFC-13B1), carbon tetrafluoride (CFC-14), dichlorofluoromethane (CFC-21), chlorodifluoromethane (CFC-22), trifluoromethane (CFC-23), 1, 2-difluoro-1,1,2,2-tetrachloroethane, 1,1,2-trichloro-1,2,2-trifluoroethane (CFC-1113),
1,2-dibromo-1-chloro-1,2,2-trifluoroethane
(CFC-1113B2), 1,2-dichloro-1,1,2,2-tetrafluoroethane (CFC-1114), 1,2-dibromo-1,1,
2,2-tetrafluoroethane (CFC-1114B2), 2,
2-dichloro-1,1,1-trifluoroethane (CFC-12
3), chlorodifluoroethane (CFC-142), 1,1-difluoroethane (CFC-152), tetrafluoroethane, chloropentafluoroethane, hexafluoroethane (CFC-1116) and the like.

Further, an azeotropic mixture of the above compounds (for example, Freon-500, Freon-502), vinyl fluoride,
Examples include vinylidene fluoride, hexafluoropropylene, tetrafluoroethylene, chlorotrifluoroethylene, propylene hexafluoride, and the like. In addition, carbon atoms other than the above are aliphatic hydrocarbons having up to three carbon atoms, and the hydrogen atom is at least selected from a fluorine atom, a chlorine atom, a bromine atom, and the like.
Halogenated aliphatic hydrocarbons substituted with one halogen atom are exemplified.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[Embodiment 1] The halogenated aliphatic hydrocarbon compound and the acidic water are brought into contact with each other by directly charging a gas containing the halogenated aliphatic hydrocarbon compound to be decomposed into the electrolyzed water generator. FIG. 1 is a schematic view of one embodiment of the apparatus for decomposing a halogenated aliphatic hydrocarbon compound according to the present invention.

In FIG. 1, reference numeral 101 denotes a water tank. The anode cell 103 and the cathode cell 104 are formed by a membrane 102 such as an ion exchange membrane.
Divided into The water tank includes a positive electrode 105 and a negative electrode 106, a power supply 107 connected to the electrodes, a pipe 108 for supplying water containing an electrolyte into the water tank, and a pump 10.
9. A pipe 110 and a pump 11 for supplying a halogenated aliphatic hydrocarbon compound to be decomposed or a medium containing the same into the water tank, and a decomposition gas containing chlorine is supplied to the anode tank 10.
3 is provided with a pipe 112 and a pump 113 for supplying the cathode tank 104 from the tank 3, and 114 is a pipe for discharging from the water tank 101, and 115 is a pipe for discharging gas.

Water containing the electrolyte dissolved in the water tank 10
08 and the water tank 101 is filled with water with dissolved electrolyte. Power supply 1 for electrodes 105 and 106 for electrolysis
When electric power is supplied from 07, acidic water is generated on the anode 105 side. Halogenated aliphatic hydrocarbon compound pipe 11
The water is continuously supplied at a desired flow rate from 0 to the anode 105 side of the water tank 101, and light is emitted from a light source 166 installed outside or inside the water tank 101.

Here, the halogenated aliphatic hydrocarbon compound comes into contact with functional water, and its decomposition is accelerated by light irradiation. The decomposed gas and chlorine from the acidic functional water are discharged into the exhaust pipe.
And supplied to the cathode tank 104 by the pump 113. The gas from which chlorine has been removed through the cathode tank 104 is discharged from a gas discharge pipe 114. Drainage pipe 11
The alkaline functional water and the acidic functional water are discharged from the water tank 101 through 5.

For the membrane, for example, the cations (for example, Na ⁺ , Ca ²⁺ , Mg ²⁺ , K ^+, etc.) existing on the anode side without moving the aqueous electrolyte solutions on the cathode side and the anode side to the opposite sides, respectively.
Exchange that allows irreversible transfer of cations to the cathode side and allows irreversible transfer of anions (eg, Cl ⁻ , SO ₄ ²⁻ , HCO ₃ ^−, etc.) present on the cathode side to the anode side. A membrane is preferably used. That is, by using an ion exchange membrane,
Functional water having characteristics as described below can be efficiently generated near the anode.

[Embodiment 2] The functional water produced by the electrolyzed water generator is transferred to a decomposition treatment tank, a halogenated aliphatic hydrocarbon compound is introduced into the decomposition treatment tank, and the two are brought into contact with each other, and light irradiation is performed thereon. FIG. 2 is a schematic view of another embodiment of the apparatus for decomposing a halogenated aliphatic hydrocarbon compound.
The acidic functional water formed on the anode side 105 by the functional water generator 120 is continuously supplied at a desired flow rate to the decomposition treatment tank 121 through a pipe 122 and a pump 123.

A halogenated aliphatic hydrocarbon compound, for example, a gasified chlorinated aliphatic hydrocarbon is continuously supplied at a desired flow rate via a supply pipe 110 and a pump 1111 to a decomposition treatment tank 1211.
And the light irradiation device 166 irradiates the inside of the decomposition treatment tank 121 with light. The chlorinated aliphatic hydrocarbon is brought into contact with the functional water in the decomposition treatment tank 121, and the decomposition treatment is accelerated by light irradiation. The functional water used in the treatment is a decomposition treatment tank
Through the drain pipe 115.

On the other hand, the alkaline functional water formed on the cathode side 106 by the functional water generator 120 is continuously supplied to the chlorination tank 124 at a desired flow rate by the pipe 125 and the pump 1.
26. The purified gas containing chlorine is discharged from a discharge pipe 112 and supplied to a chlorination tank 124 by a pump 113.

The gas from which chlorine has been removed through the chlorination tank 124 is discharged from a gas discharge pipe 114. Decomposition tank 121, chlorination tank 1 through drainage pipes 115a, b
The acidic and alkaline functional water from 24 is discharged.

[Embodiment 3] FIG. 3 is a schematic view of another embodiment of the apparatus for decomposing a halogenated aliphatic hydrocarbon compound.
This is an apparatus assuming that the halogenated aliphatic hydrocarbon compound to be decomposed is easily vaporized such as trichloroethylene.

In FIG. 3, reference numeral 120 denotes a functional water generator,
1 is a column-shaped halogenated aliphatic hydrocarbon compound decomposition tank, 166 is a light irradiation device for irradiating the decomposition tank with light, 1
Reference numerals 22 and 123 denote pipes and pumps for supplying the acidic functional water obtained by the functional water generator 120 to the decomposition vessel 121. The number of connected decomposition tanks can be appropriately selected depending on the concentration of the halogenated aliphatic hydrocarbon compound, the ease of decomposition, and the like.

On the other hand, the alkaline functional water formed on the cathode side 106 by the functional water generator 120 is continuously supplied to the chlorination tank 124 at a desired flow rate with a pipe 125 and a pump 1.
26. The purified gas containing chlorine is discharged from a discharge pipe 112 and supplied to a chlorination tank 124 by a pump 113. The gas from which chlorine has been removed through the chlorination tank 124 is discharged from a gas discharge pipe 114. The acidic functional water and the alkaline functional water are discharged from the decomposition treatment tank 121 and the chlorination treatment tank 124 through the drain pipes 115a and 115b.

[Embodiment 4] Various embodiments according to the present invention can be effectively applied to purification of exhaust gas discharged from a combustion furnace or a garbage incinerator in a factory or the like.

In this embodiment, the halogenated aliphatic hydrocarbon compound can be efficiently decomposed simply by bringing the halogenated aliphatic hydrocarbon compound into contact with functional water and irradiating the functional water with light. Just contacting the halogenated aliphatic hydrocarbon compound with the exhaust gas and the functional water and irradiating the light, some of the halogenated aliphatic hydrocarbon compound in the exhaust gas is surely decomposed, which is extremely effective in purifying the exhaust gas. It is expected that it will be a technology.

When the technique for decomposing halogenated aliphatic hydrocarbon compounds according to the present embodiment is applied to the purification of exhaust gas, it is possible to suitably use an apparatus having the structure shown in FIG. 4 described below. Conceivable.

In FIG. 4, reference numeral 161 denotes a garbage incinerator; 163, a device for removing dust (eg, an electric dust collector) in exhaust gas discharged from the garbage incinerator; 120, a functional water generator; and 165, a functional water generator. And 166, a light irradiation device for irradiating the inside of the reaction tank with light.

The electrolyte aqueous solution storage means 129 stores an electrolyte aqueous solution necessary for producing functional water (a solution obtained by dissolving a water-soluble electrolyte in raw water). Dust removal device 1
63 mainly removes soot and dust contained in exhaust gas generated during incineration of garbage, and the collected soot and dust can be taken out.

Reference numeral 120 denotes a functional water generating means. The acidic functional water obtained near the anode 105 of the functional water generating means 120 can be supplied to the reaction tank 165. Further, the reaction tank 165 is configured so that the exhaust gas and the functional water come into efficient contact with each other.
A light irradiation device 166 is provided inside or outside 65.

Further, the halogenated aliphatic hydrocarbon compound is removed, and the purified exhaust gas containing chlorine is supplied to the reaction tank 16.
5 is supplied to the chlorination treatment tank 124 from the gas discharge means 112 of FIG. The gas from which chlorine has been removed through the chlorination tank 124 is discharged from a gas discharge pipe 114. Decomposition tank 121, chlorination tank 124 through drainage pipes 115a, b
Acidic and alkaline functional water are discharged from the plant.

Next, the exhaust gas removing step having this configuration will be described. Exhaust gas from the refuse incinerator 161 is first introduced into a dust collecting device 163, and most of the soot is removed by this device. Further, the aqueous solution of the electrolyte is supplied from the tank 129 to the functional water generating means 120, where the electrolytic water is electrolyzed. Then, the acidic functional water generated near the anode of the functional water generating means 120 is sent to the reaction tank 165.

In the reaction tank 165, the exhaust gas and the functional water are mixed in contact with each other, and the inside of the reaction tank 165 is irradiated with light by the light irradiation device 166 to decompose the halogenated aliphatic hydrocarbon compound in the exhaust gas. Is purified. Next, the treated chlorine-containing exhaust gas is exhausted from the exhaust port 112 and supplied to the chlorinating tank 124.

The chlorination tank 124 contains a functional water generating means 120
Is supplied in the vicinity of the cathode, and the chlorine reacts with the alkaline functional water to remove the chlorine. The gas from which chlorine has been removed is a gas exhaust pipe 114
Is discharged from The acidic functional water and the alkaline functional water are discharged from the decomposition treatment tank 121 and the chlorination treatment tank 124 through the drain pipes 115a and 115b.

When the exhaust gas treatment apparatus for a refuse incinerator according to the present basic configuration was actually applied to exhaust gas treatment, 99 to 99.7% of halogenated aliphatic hydrocarbon compounds were decomposed and removed. From this, it is apparent that the present basic configuration has extremely excellent exhaust gas purification processing ability.

Although various embodiments according to the present invention have been specifically described above, the present invention can be applied to other embodiments. For example, the processing apparatus of the present invention is not limited to exhaust gas of a refuse incinerator, It can also be used for the treatment of exhaust gas (such as automobile exhaust gas).

[0063]

EXAMPLES Further, more specific examples will be described.

Example 1 Device for Decomposing Trichlorethylene (TCE) in Gas State The device shown in FIG. 1 was prepared. Strongly acidic functional water generator 1
01 (trade name: strong electrolyzed water generator (Model FW-200; manufactured by Amano Corp.)) was provided with an inlet pipe 110 for introducing a gas containing TCE into the anode side. A gas supply device (standard gas generator, trade name: Gastec, PD-1B) is connected to the tank, while an aqueous solution of the electrolyte is supplied to the strongly acidic functional water generator 101 from a tank storing water in which the electrolyte is dissolved. The pump 109 and the pipe 108 were installed as described above, and the water tank 101 of the strongly acidic electrolyzed water generator was filled with the water in which the electrolyte was dissolved by using the pump.
It was continuously fed at a flow rate of mL / min. At the same time, operation using a strongly acidic electrolyzed water generator
pH 2.1, redox potential 1150 mV, residual chlorine concentration 54
The production of functional water having a property of mg / L was confirmed. Further, light irradiation means 166 (black light fluorescent lamp (manufactured by Toshiba, FL1
0BLB, 10W)) to irradiate the anode side 105.

The TCE in the waste liquid discharged from the drain port 118 on the anode 105 side of the strongly acidic electrolyzed water generator 101 is extracted with hexane, and the concentration of TCE contained therein is measured by gas chromatography with an ECD detector (trade name). : GC-14B; manufactured by Shimadzu Corporation), and the TCE concentration was 0.03 ppm or less.

When the chlorine concentration in the gas discharged from the discharge pipe 112 was measured by a gas detection pipe (Gastec), the chlorine concentration in the gas discharged from the anode tank 103 was 2 ppm or more. This gas was passed through the discharge pipe 112 into the alkaline functional water in the cathode tank 104. The concentration of chlorine discharged from the cathode tank 104 to the gas discharge pipe 114 was measured with a gas detector tube (Gastec) and found to be 0.05 ppm or less.

Example 2 Continuous Decomposition of Trichlorethylene in Gas State by Functional Water A TCE decomposition experiment was performed using the decomposition apparatus shown in FIG. The same apparatus as that used in Embodiment 1 is used as the strongly acidic functional water generator 120, and the p-side obtained on the anode side is used.
H2.1, redox potential 1150mV, residual chlorine concentration 54
mg / L of functional water using feed pipe 122
The solution was continuously supplied to the decomposition column 121 at a flow rate of mL / min.
The decomposition column 12 1 had a volume of 6000 mL. Further, light irradiation means 166 (black light fluorescent lamp (manufactured by Toshiba, FL1
0BLB, 10W)). on the other hand,
A gas supply device 127 (standard gas generator, Gastec, PD-1B) is supplied with air containing 1700 ppm of TCE in gas phase concentration.
To 100 mL / min from the bottom of the decomposition column 121 continuously.

TC in the gas in the discharge pipe of the cracking column 121
The E concentration was measured by gas chromatography, and the chlorine concentration was measured by a gas detector tube (Gastec). As a result, the TCE concentration in the exhaust gas was 0.1 ppm or less, but the chlorine concentration was 2 ppm.
m or more.

On the other hand, the alkaline functional water formed on the cathode side 106 by the functional water generator 120 is continuously supplied to the chlorination tank 124 at a desired flow rate with the pipe 125 and the pump 1.
26. The exhaust gas from the decomposition column 121 was passed through the discharge pipe 112 into the alkaline functional water in the chlorination tank 124. Pipe 1 of chlorination tank 124
Gas detector tube (Gastec)
Was less than 0.05 ppm.

[0070]

As described above, according to the present invention, halogenated aliphatic hydrocarbon compounds can be economically and safely and stably decomposed at normal temperature and normal pressure, and the chlorine odor generated thereby can be removed. It can be removed efficiently.

Further, the purification of exhaust gas containing various halogenated aliphatic hydrocarbon compounds can be performed very easily.

[Brief description of the drawings]

FIG. 1 is a schematic view of an apparatus for decomposing gaseous halogenated aliphatic hydrocarbon compounds according to one embodiment of the present invention.

FIG. 2 is a schematic diagram of an apparatus for decomposing gaseous halogenated aliphatic hydrocarbon compounds according to another embodiment of the present invention.

FIG. 3 is a schematic view of an apparatus for decomposing gaseous halogenated aliphatic hydrocarbon compounds according to still another embodiment of the present invention.

FIG. 4 is a schematic view of an exhaust gas purifying apparatus according to an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 101 water tank 102 diaphragm, ion exchange membrane 103 anode tank 104 negative electrode tank 105 positive electrode 106 negative electrode 107 power supply 108, 110, 112, 122, 125 pipe 109, 111, 113, 123, 126 pump 114 exhaust pipe 115, 115a 115b Drainage pipe 120 Functional water generator 121 Decomposition treatment tank 124 Chlorine treatment tank 161 Garbage incinerator 163 Dust removal device 165 Reaction tank 166 Light irradiation device

Claims (11)

[Claims] 1. An acidic functional water and a gas containing a halogenated aliphatic hydrocarbon compound generated on the anode side by electrolysis performed by disposing a cathode and an anode in each of two regions communicating with each other through a diaphragm. A method for decomposing a halogenated aliphatic hydrocarbon compound having a step of contacting under irradiation, wherein the gas discharged from the acidic functional water containing the decomposition product after the light irradiation treatment is generated on the cathode side. A method for decomposing a halogenated aliphatic hydrocarbon compound, which is brought into contact with water. 2. The decomposition method according to claim 1, wherein the step of bringing the gas separated from the acidic functional water containing the decomposition product after the light irradiation treatment into contact with the alkaline functional water generated on the cathode side is by ventilation. . 3. The decomposition method according to claim 1, wherein the halogenated aliphatic hydrocarbon compound is an aliphatic hydrocarbon compound substituted with at least one element of chlorine and fluorine. 4. The method according to claim 1, wherein the aliphatic hydrocarbon compound is trichlorofluoromethane, dichlorodifluoromethane, chlorotrifluoromethane, dichlorofluoromethane, chlorodifluoromethane, trifluoromethane, 1,2-difluoro-1,1,2,2- Tetrachloroethane, 1,1,2-trichloro-1,2,2-trifluoroethane, 1,2-dichloro-1,1,
2,2-tetrafluoroethane, 2,2-dichloro-1,1,1-
The decomposition method according to claim 3, wherein the decomposition method is at least one of trifluoroethane, chlorodifluoroethane, 1,1-difluoroethane, tetrafluoroethane, chloropentafluoroethane, hexafluoroethane, chloroethylene, tetrachloroethylene, and trichloroethylene. 5. The decomposition method according to claim 1, wherein the halogenated aliphatic hydrocarbon compound is contained in an exhaust gas. 6. A container provided with two regions that communicate with each other via a diaphragm, a pair of electrodes each serving as a cathode and an anode, and a power source for applying a potential to the electrodes, and an electrolyte dissolved in the container. Means for supplying water, means for irradiating the container with light, and means for supplying a gas containing a halogenated aliphatic hydrocarbon compound to the anode side of the electrode, wherein the apparatus for decomposing a halogenated aliphatic hydrocarbon compound comprises: A halogenated aliphatic carbon having means for contacting gas discharged from acidic functional water containing decomposition products after the light irradiation treatment on the anode side of the electrode with alkaline functional water generated on the cathode side. Hydrogen compound decomposition equipment. 7. An acidic functional water generated on an anode side by electrolysis of water in which an electrolyte is dissolved, wherein a cathode and an anode are arranged in each of two regions communicating with each other via a decomposition treatment tank and a diaphragm. Halogenated aliphatic hydrocarbon compound having means for supplying a processing tank, means for supplying a gas containing a halogenated aliphatic hydrocarbon compound to be decomposed to the decomposition processing tank, and means for irradiating light to the decomposition processing tank The decomposition apparatus, wherein the exhaust gas from the decomposition treatment tank is provided with means for contacting the alkaline functional water generated on the cathode side by electrolysis of the water in which the electrolyte is dissolved. Disassembly device. 8. The decomposition apparatus according to claim 6, wherein the means for bringing the gas into contact with the alkaline functional water generated on the cathode side is by ventilation. 9. The cracking apparatus according to claim 6, wherein the halogenated aliphatic hydrocarbon compound is an aliphatic hydrocarbon compound substituted with at least one element of chlorine and fluorine. 10. The method according to claim 10, wherein the aliphatic hydrocarbon compound is trichlorofluoromethane, dichlorodifluoromethane, chlorotrifluoromethane, dichlorofluoromethane, chlorodifluoromethane, trifluoromethane, 1,2-difluoro-1,1,2,2- Tetrachloroethane, 1,1,2-trichloro-1,2,2-trifluoroethane, 1,2-dichloro-1,
1,2,2-tetrafluoroethane, 2,2-dichloro-1,1,1
-Trifluoroethane, chlorodifluoroethane, 1,1-
The decomposition apparatus according to claim 9, wherein the decomposition apparatus is at least one of difluoroethane, tetrafluoroethane, chloropentafluoroethane, hexafluoroethane, chloroethylene, tetrachloroethylene, and trichloroethylene. 11. The cracking device according to claim 6, wherein the halogenated aliphatic hydrocarbon compound is contained in an exhaust gas.