JP2001170201A - Decomposition treatment method for hazardous chlorine compound and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-polluting treatment method for hazardous chlorine compounds, such as, for example, polybiphenyl chloride, by dechlorination and a device therefor. SOLUTION: This decomposition treatment device for the hazardous chlorine compounds has a dissolution tank 12 which dissolves the hazardous chlorine compounds 1 in aliphatic hydrocarbon 2 or alkaline agent 3 or both thereof, a disk-shaped turntable 15 which is formed with a hollow groove 16 on its top surface, a pipeline 14 which supplies a dissolving liquid 4 from the dissolution tank to the hollow groove of the turntable, an electron beam irradiation device 23 which irradiates the dissolving liquid supplied to the hollow grooves with electron beams, a scraper 17 which takes the treating liquid 5 subjected to the irradiation with the electron beam out of the hollow groove and a solid- liquid separation tank 18 which subjects the treating liquid taken out by the scraper to a separation of solid from the liquid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for detoxifying harmful chlorine compounds such as polychlorinated biphenyls by dechlorination.

[0002]

2. Description of the Related Art FIG. 5 is a conceptual view showing an example of a conventional PCB decomposition processing apparatus for detoxifying a typical polychlorinated biphenyl (hereinafter referred to as PCB) as a harmful chlorine compound by dechlorination decomposition. FIG. This apparatus mainly includes a reaction tank 72, a heater 73, a cooling tank 74, a cooler 75, and the like.

[0005] As shown in FIG.
After the alkali agent 52 was added together with the contained oil 51, the carbon-based catalyst 54 and the hydrogen donor 55 were prepared in the oil preparation tank 71 and added through the pipe 56, and then the nitrogen gas 53 was supplied. In a nitrogen atmosphere, the mixture added to the reaction tank 72 by the heater 73 is heated to 300 to 350 ° C. and stirred to release chlorine atoms from PCB molecules.

[0004] The generated gas 57 from the reaction tank 72 is condensed in a three-stage condenser 77. That is, oil is mainly condensed in the first two stages, and the condensed oil 58 is sent back to the reaction tank 72. Then, the water 59 is removed by the third-stage condenser 77. The remaining exhaust gas 60 passes through the first activated carbon layer of the activated carbon adsorption tower 78 from the pipe 61 through the vacuum tank 79, passes through the second activated carbon layer of the activated carbon adsorption tower 78, and goes out of the pipe 62 to the outside of the system. Is discharged.

On the other hand, the treated oil 63 taken out of the reaction tank 72 is introduced into a cooling tank 74 and cooled by a cooler 75. The cooled treated oil 64 is supplied to a desalination unit 76.
To remove it as a separation oil 65. However, in the conventional PCB decomposition processing apparatus as described above, high-temperature heating means in a reaction tank, cooling means in a cooling tank,
Further, there is a problem that a complicated equipment configuration such as a condenser is required, and that expensive catalysts are consumed, and that processing and operating costs are high due to handling at high temperatures.

[0006]

Therefore, in the present invention,
It is an object of the present invention to provide a method and an apparatus for decomposing harmful chlorine compounds, which can dechlorinate PCB almost completely at around normal temperature, consume less energy, and reduce operation and treatment costs.

[0007]

The present invention is characterized in that a harmful chlorine compound is dissolved in an aliphatic hydrocarbon, the solution is irradiated with an electron beam and detoxified by a dechlorination reaction. This can be achieved by the following apparatus based on the compound decomposition treatment method. Further, in the decomposition treatment method of the present invention, a harmful chlorine compound is dissolved in an aliphatic hydrocarbon and an alkali agent is added, and the solution is irradiated with an electron beam to be detoxified by a dechlorination reaction. A method for decomposing a harmful chlorine compound, which is characterized in that the harmful chlorine compound is a PCB-containing oil and the aliphatic hydrocarbon is a saturated hydrocarbon or an unsaturated hydrocarbon. Including.

Further, the above method of the present invention comprises a dissolving tank for dissolving a harmful chlorine compound in an aliphatic hydrocarbon and / or an alkaline agent, and a disk-shaped rotary table having a concave groove formed on the upper surface. A conduit for supplying the dissolving solution from the dissolving tank to the groove of the rotary table, an electron beam irradiating device for irradiating the dissolving solution supplied to the groove with an electron beam, A device for decomposing a harmful chlorine compound, comprising: a scraper for taking out the processed processing solution from the groove, and a solid-liquid separation tank for solid-liquid separation of the processing solution taken out by the scraper. Achieved by

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail by embodiments, but the content of the present invention is not limited to these embodiments. In the description, the same members as those in FIG. 5 are denoted by the same reference numerals, and redundant description will be omitted.

First Embodiment In this embodiment, PCB is dissolved in an aliphatic hydrocarbon,
After the addition of the alkali agent, the PCB is irradiated with an electron beam to dechlorinate and detoxify the PCB. Hereinafter, this will be described in detail with reference to FIG.

As shown in FIG. 1, in this embodiment, a storage tank 11, a dissolution tank 12, a rotary table 15,
It is composed of an electron beam irradiation device 23, a solid-liquid separation tank 18, and the like. The storage tank 1 is located in the dissolving tank 12 at the left end of the drawing.
PCB-containing oil 1 supplied from 1 and aliphatic hydrocarbon (saturated hydrocarbon or unsaturated hydrocarbon) 2 that dissolves PCB
And an addition port for an alkaline agent 3 such as NaOH, KOH, etc., and a stirring blade 13 connected to a driving motor M for stirring and mixing the additives is provided at the center of the bottom. A supply pipe 14 for supplying the solution 4 in which the PCB has been dissolved into the concave groove 16 of the rotary table 15 is provided at the bottom right end.

A groove 16 is formed on the upper surface of the rotary table 15 to which the solution 4 in which the PCB is dissolved is supplied. The rotary table 15 is a disk-shaped table rotated by a drive motor M, and has a diameter of, for example, 500 to 10.
It is preferable that the size is reduced to about 00 mm. Reference numeral 16 denotes a circular groove formed on the upper surface of the rotary table 15, and its depth is preferably about several mm.

At the upper part of the circular groove 16 in the vertical direction,
An electron beam irradiation device 23 is connected to the power source 21 and the control unit 22 and irradiates the electron beam 24 toward the thin-film processing liquid 5 in the groove 16. The control unit 22 has a built-in operation panel and the like for the electron beam irradiation device 23. The control unit 22 controls the energy and intensity of the electron beam 24, the absorbed dose, and the like that are optimal for PCB decomposition.

Reference numeral 17 denotes a processing solution obtained by decomposing a PCB by electron gland irradiation.
It is a scraper taken out from inside. This scraper 17
Is engaged with the inside of the concave groove 16 and is disposed at one position on the circumference. The treatment liquid 6 taken out by the scraper 17 is combined with biphenyl (oil) 7 and salt (NaCl).
Or KCl) 8 and an aliphatic hydrocarbon are separated in a solid-liquid separation tank 18 at the lower right of the figure.

The procedure for treating the PCB-containing oil 1 based on the method of the present invention in the apparatus for decomposing harmful chlorine compounds having the above structure will be described. First, dissolution tank 1
2, a PCB-containing oil 1 and an aliphatic hydrocarbon (saturated hydrocarbon or unsaturated hydrocarbon) 2 from a storage tank 11 are supplied, and an alkali agent 3 is further added. The PC is stirred by the stirring blade 13.
Dissolve B. Then, the dissolved solution 4 is supplied from the pipe 14 to the concave groove 16 of the rotary table 15 in a fixed amount. For example, a rotating tape rotating at a rotation speed of 30 rpm
The solution 4 supplied through the pipe 14 at a rate of about 1 liter / minute to the solution 15 gradually becomes a thin film-form treatment solution 5,
An embodiment in which the electron beam 24 is irradiated from above when reaching the position rotated by 3/4 is preferable.

The mixing ratio of the PCB-containing oil to be treated in the treatment liquid is preferably such that the plain PCB is 0.5% to 30%. PCB content rate
If it exceeds 30%, the dechlorination performance deteriorates, which is not preferable. If it is lower than 0.5%, the PCB concentration in the processing solution is too low, and the processing cost is undesirably high. Similarly, the mixing ratio of the alkali agent at this time is 0.1% to 2% in the processing solution.
It is preferably about 0%. If the alkali concentration exceeds 20%, the processing cost becomes relatively high, which is not preferable.
% Is not preferred because the dechlorination performance decreases.
In the present invention, alkane hydrocarbons that are particularly suitable among the alkane hydrocarbons used in the PCB treatment include pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, and hexadecane. , Heptadecane, octanedecane, nonadecane, eicosane and the like are preferable. As the alkali agent, KOH or NaOH is preferable.

Then, by irradiating the electron beam 24 toward the processing liquid 5 in the form of a thin film, the PCB in the processing liquid is dechlorinated and decomposed. The energy intensity of this electron beam 24,
The absorbed dose and the like are adjusted by a control signal from the control unit 22 sent to the electron beam irradiation device 23. The energy intensity and the like can be appropriately changed depending on the thickness of the film of the processing liquid 5 in the form of a film. For example, when the thickness of the film is about 1 mm, it is preferably about 300 KeV.

Next, the liquid 6 decomposed by the electron beam irradiation is taken out of the groove 16 by the scraper 17 while rotating, and sent to the solid-liquid separation tank 18. Therefore, harmless biphenyl (oil) 7 and salt (NaCl or KCl) 8
Is separated into aliphatic hydrocarbons. The detoxified biphenyl 7 (oil) is taken out and incinerated, and the remaining salt (NaCl or KCl) 8 is discarded.

According to this embodiment, there is an effect that the PCB can be almost completely dechlorinated and converted into harmless biphenyl. In addition, since the method for decomposing PCB by electron beam irradiation of the present invention can be performed at around room temperature,
The above-mentioned dissolving tank 12, rotating table 15, solid-liquid separating tank 18
And all the components such as the electron beam irradiation device 23 can be operated near room temperature, so that heat energy loss is small, handling operation can be performed safely, and operating and processing costs are greatly reduced compared to the conventional method. There is also an effect that can be performed.

Second Embodiment This embodiment is different from the first embodiment in that a heating coil 35 is provided in the dissolving tank 12, and the dissolving tank is heated by cooling water (hot water) of a newly provided private generator. It is designed to be warm. Other configurations are the same as those of the first embodiment. Hereinafter, description will be made with reference to FIG. As shown in FIG. 2, a heat insulating material 12a is attached to the outer wall of the melting tank 12, and a heating coil 35 is provided at the bottom.
The cooling water (hot water) of the water-cooled engine 32 is sent from the supply pipe 36 to the heating coil 35, and after heat exchange, the return pipe 3
7 circulates back to the radiator 31 for radiating the cooling water. Reference numeral 33 denotes a private power generator driven by the engine 32, and reference numeral 34 denotes a power cable for transmitting power generated from the private power generator 33 to the power supply 21.

A procedure for treating the PCB-containing oil 1 based on the method of the present invention in the apparatus for decomposing harmful chlorine compounds having the above structure will be described. The PCB-containing oil 1, the aliphatic hydrocarbon 2, and the alkali agent 3 supplied into the melting tank 12 are heated to a temperature ranging from room temperature to about 80 ° C. by the heating coil 35, and are stirred by the stirring blades 13. Can be dissolved in a short time. Here, the used amount of the PCB-containing oil 1 and the like, the energy intensity of the electron beam 24, the absorbed dose, and the like are the same as those in the first embodiment. In addition, since power from the private generator 33 is sent to the power supply 21 as a power supply for the electron beam irradiation device 23,
No external power supply is required. Further, cooling water (hot water) of the engine 32 of the private generator 33 is supplied to the heating coil 35.
Can be used effectively as a heat source.

According to this embodiment, separately from the operation and effect of the first embodiment, the heating coil 35 is provided in the melting tank 12.
Is provided, the time for dissolving the liquid to be treated can be shortened, and the power is supplied by the private generator, and the engine cooling water (hot water) is used as a heat source of the heating coil, so that energy consumption is reduced. It further has the function and effect that it can be reduced.

Third Embodiment In this embodiment, compared to the first embodiment, the dissolving tank 12
The PCB-containing oil, the aliphatic hydrocarbon, and the alkali agent are added to the dissolution / reaction tank 41 instead of the dissolution / reaction tank 41 to directly dissolve the PCB-containing oil dissolved solution from above the dissolution / reaction tank 41. It is configured to perform electron beam irradiation, and simplifies the equipment configuration. Other configurations are the same as those of the first embodiment. Hereinafter, description will be made with reference to FIG.

As shown in FIG. 3, reference numeral 41 denotes the dissolution of PCB.
In a reaction tank, a PCB-containing oil 1 and an aliphatic hydrocarbon (saturated hydrocarbon or unsaturated hydrocarbon) 2 for dissolving the PCB are supplied thereto, and an alkali agent 3 such as NaOH or KOH is added thereto. . A stirring blade 43 connected to a driving motor M for stirring and mixing such additives has a dissolution / reaction tank 41.
Is provided at the bottom center.

An electron beam irradiation device 23 similar to that of the first embodiment is disposed above a dissolution / reaction tank 41. Reference numeral 42 denotes a baffle plate attached to a plurality of locations on the inner peripheral wall of the dissolution / reaction tank 41. Reference numeral 44 denotes a supply pipe for taking out the treated liquid after electron beam irradiation from the dissolution / reaction tank 41 and supplying it to the solid-liquid separation tank 45. It is. The solid-liquid separation tank 45 converts the processing liquid taken out through the supply pipe 44 into biphenyl (oil) and salt (NaCl or
KCl) and aliphatic hydrocarbons.

The procedure for treating the PCB-containing oil 1 based on the method of the present invention in the apparatus for decomposing harmful chlorine compounds having the above structure will be described. First, the PCB-containing oil 1, the aliphatic hydrocarbon 2, and the alkali agent 3 supplied into the dissolution / reaction tank 41 are dissolved while being stirred and mixed by the stirring blade 43. Reference numeral 42 denotes baffles attached to a plurality of locations on the inner peripheral wall of the dissolution / reaction tank 41. Due to the presence of these baffles, the processing liquid agitated by the stirring blades 43 is in a turbulent state, and the processing liquid surface A new liquid level appears on the
The entire treatment liquid can be treated by electron beam irradiation from the treatment liquid surface.

Then, an electron beam 24 from the electron beam irradiation device 23 is irradiated from above the dissolution / reaction tank 41 toward the liquid to be treated, thereby decomposing the PCB and performing dechlorination. Also,
The mixing ratio of the PCB-containing oil 1 and the like used in the processing liquid is the same as that of the first embodiment, but the energy intensity of the electron beam 24 is not restricted, and only the absorbed dose is the first. This is the same as in the embodiment. Next, the processing solution dechlorinated and decomposed by electron beam irradiation is sent from a supply pipe 44 to a solid-liquid separation tank 45, where harmless biphenyl (oil) is added.
It is separated into salts (NaCl or KCl) and aliphatic hydrocarbons.
The detoxified biphenyl (oil) 7 is taken out and incinerated, and the remaining salt (NaCl or KCl) 8 is discarded.

According to this embodiment, apart from the operation and effect of the first embodiment, the apparatus configuration can be simplified as compared with the first embodiment.
1. Since all the components such as the solid-liquid separation tank 45 and the electron beam irradiation device 23 are operated near normal temperature, the equipment cost is low, the heat energy loss is small, and the handling operation can be performed safely. It also has actions and effects.

Fourth Embodiment This embodiment is different from the third embodiment in that a heating coil is provided in the dissolution / reaction tank 41 as shown in FIG. The dissolution / reaction tank 41 can be heated by hot water. Other configurations are the same as those of the third embodiment. This will be described below with reference to FIG.

As shown in FIG. 4, a heat insulating material 41a is attached to the outer wall of the dissolution / reaction tank 41, and a heating coil 35 is provided at the bottom. The cooling water (warm water) of the water-cooled engine 32 is sent from the supply pipe 36 to the heating coil 35, and after heat exchange, circulates from the return pipe 37 to the radiator 31 for radiating the cooling water. . Reference numeral 33 denotes a private power generator driven by the engine 32, and reference numeral 34 denotes a power cable for transmitting power generated from the private power generator 33 to the power supply 21. Other configurations are the same as those of the third embodiment.

The procedure for treating the PCB-containing oil 1 based on the method of the present invention in the apparatus for decomposing harmful chlorine compounds having the above structure will be described. Dissolution / reaction tank 4
1, PCB-containing oil 1, aliphatic hydrocarbons 2,
Alkaline agent 3 is at room temperature to about 80 ° C by heating coil 35
, And are stirred and dissolved by the stirring blade 43. Further, since the stirring effect is enhanced by the baffle plate 42, the liquid to be treated can be dissolved in a short time.

The amount of the PCB-containing oil 1 and the like used here, the absorbed dose of the electron beam 24, and the like are the same as in the first embodiment. Also, a power supply 21 for the electron beam irradiation device 23
Is supplied with electric power from the private generator 33, so that there is no need to supply electric power from the outside.
The cooling water (hot water) of the engine 32 can be effectively used as a heat source of the heating coil 35.

According to this embodiment, apart from the operation and effect of the third embodiment, the heating coil 35 is provided in the dissolution / reaction tank 41, so that the dissolution time of the liquid to be treated can be shortened. Power can be supplied by a private generator and the cooling water (warm water) of the engine is used as a heat source for the heating coil, so that the energy consumption can be reduced.
It also has an effect.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of an apparatus for decomposing harmful chlorine compounds according to Example 1 of the present invention.

FIG. 2 is a conceptual diagram showing an apparatus for decomposing harmful chlorine compounds according to Example 2 of the present invention.

FIG. 3 is a conceptual diagram showing an apparatus for decomposing harmful chlorine compounds according to Example 3 of the present invention.

FIG. 4 is a conceptual diagram showing an apparatus for decomposing harmful chlorine compounds according to Example 4 of the present invention.

FIG. 5 is a conceptual diagram showing an example of a conventional polychlorinated biphenyl (PCB) decomposition processing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 PCB-containing oil 2 Aliphatic hydrocarbon 3 Alkali agent 4 Dissolution 5 Treatment liquid 6 Treatment liquid 7 Biphenyl oil 8 Salt for disposal 11 Storage tank 12 Dissolution tank 12a Insulation material 13 Stirrer blade 14 Pipe line 15 Rotation table 16 Groove Reference Signs List 17 scraper 18 solid-liquid separation tank 21 power supply 22 control unit 23 electron beam irradiation device 24 electron beam 31 radiator 32 engine 33 private generator 35 heating coil 41 melting / reaction tank 42 baffle plate 45 solid-liquid separation tank 51 oil containing PCB 52 Alkali 53 Nitrogen gas 54 Carbon-based catalyst 55 Hydrogen donor 56 Pipeline 57 Generated gas 58 Condensed oil 59 Water 60 Exhaust gas 61 Pipeline 62 Pipeline 63 Treated oil 64 Treated oil 65 Separated oil 71 Oil blending tank 72 Reaction tank 73 Heater 74 cooling tank 75 cooler 76 desalination equipment 77 three-stage condenser 78 activated carbon Chakuto 79 vacuum tank

Claims (7)

[Claims] A method for decomposing a harmful chlorine compound, comprising dissolving a harmful chlorine compound in an aliphatic hydrocarbon, irradiating the solution with an electron beam, and detoxifying the compound by a dechlorination reaction. 2. A harmful chlorine characterized by dissolving a harmful chlorine compound in an aliphatic hydrocarbon, adding an alkali agent, irradiating the solution with an electron beam and detoxifying the solution by a dechlorination reaction. Compound decomposition treatment method. 3. The decomposition treatment of a harmful chlorine compound according to claim 1, wherein the harmful chlorine compound is a PCB-containing oil, and the aliphatic hydrocarbon is a saturated hydrocarbon or an unsaturated hydrocarbon. Method. 4. A dissolving tank for dissolving a harmful chlorine compound in an aliphatic hydrocarbon and / or an alkaline agent, a disk-shaped rotary table having a concave groove formed on an upper surface, and a rotating table having the same. A conduit for supplying the dissolving solution from the dissolving tank to the groove, an electron beam irradiator for irradiating the dissolving solution supplied to the groove with an electron beam; An apparatus for decomposing harmful chlorine compounds, comprising: a scraper to be taken out from a groove; and a solid-liquid separation tank for solid-liquid separation of the treatment liquid taken out by the scraper. 5. The decomposition processing apparatus according to claim 4, further comprising a heating means for heating the solution in the dissolving tank. 6. A dissolution / reaction tank for dissolving and reacting a harmful chlorine compound in an aliphatic hydrocarbon or an alkali agent or both, and an electron beam for irradiating a solution in the dissolution / reaction tank with an electron beam. A hazardous device comprising: an irradiation device; a supply pipe for taking out the liquid irradiated with the electron beam from the dissolution / reaction tank; and a solid-liquid separation tank for solid-liquid separation of the treatment liquid taken out of the supply pipe. Decomposition equipment for chlorine compounds. 7. The decomposition treatment apparatus according to claim 6, further comprising a heating means for heating the solution in the dissolution / reaction tank.