JP4119630B2 - Hazardous substance treatment system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a hazardous substance processing system capable of completely processing PCB contaminated equipment such as a transformer.
[0002]
[Background]
In recent years, PCB (Polychlorinated biphenyl, a generic name for chlorinated isomers of biphenyl) is strongly toxic, and its production and import are prohibited. Although this PCB was manufactured in Japan around 1954, the adverse effects on the living body and the environment became apparent in the wake of the Kanemi oil affairs. There is a history that was done.
PCB has 1 to 10 chlorine atoms substituted on the biphenyl skeleton. There are theoretically 209 types of isomers depending on the number and position of substituted chlorine, and about 100 or more types of isomers are currently confirmed in commercially available PCB products. In addition, since the physical and chemical properties among these isomers, in-vivo stability, and environmental moving bodies are diverse, the chemical analysis of PCBs and the mode of environmental pollution are complicated. Further, PCB is one of the persistent organic pollutants, hardly decomposes in the environment, is fat-soluble and has a high bioconcentration rate. In addition, it is semi-volatile and can be moved via the atmosphere. In addition, it has been reported to remain in the environment such as water and living things.
This PCB was designated as a specially controlled waste based on the Waste Disposal, Waste Oil containing PCB, and PCB Contaminated Substances in 1997, and in 1997. Wood waste and fiber waste were additionally designated as PCB contaminants.
Examples of electrical devices that are processed PCBs include high voltage transformers, high voltage capacitors, low voltage transformers and capacitors, and pole transformers. Examples of waste PCBs include those used as insulating oils for those used as heat medium, and kerosene used for these cleanings, and examples of waste pressure sensitive paper include capsule oils used for carbonless paper. . Furthermore, use of these PCBs or exchange of heat medium, regeneration of insulating oil, purification of leaks, activated carbon used when processing PCB-containing materials, PCB contamination of waste white clay, waste waste, work clothes, etc. There is a thing.
Currently, these are strictly stored, but prompt PCB processing is desired.
[0003]
In recent years, various techniques for processing PCBs used in such transformers have been developed. For example, a technique described in Japanese Patent Application Laid-Open No. 9-79531 is known.
[0004]
FIG. 4 shows a flowchart of the PCB processing method according to the above proposal.
As shown in FIG. 4, first, oil is extracted from the transformer in which the PCB is enclosed (step S901), and the PCB adhering to the inside is removed by solvent washing (step S902) and recovered (step S903). . The solvent after washing is decomposed together with the oil extracted from the transformer (step S904) and rendered harmless.
[0005]
Next, the oil-removed transformer is dried and PCB is evaporated by high-temperature and normal-pressure heating in the absence of oxygen (step S905) to prevent the PCB from scattering. Then, the dried transformer is disassembled (step S906), and the case and the transformer core are separated. The case is used as a scrap source for an electric furnace or converter (step S907). On the other hand, the copper core of the transformer core is cut by a mobile shear or the like and separated into a coil wire and an iron core (step S908).
[0006]
The separated iron core is melted and recovered in a melting furnace (step S909). Further, the separated copper coil and the organic matter such as paper attached thereto are melted in an induction heating furnace (step S910). The molten copper is recovered, and the PCB gas generated in each melting furnace is rendered harmless by high-temperature pyrolysis at 1200 ° C. (step S911).
[0007]
[Problems to be solved by the invention]
However, in the above conventional PCB processing method, since organic substances such as paper used for copper coils are burned in a melting furnace without being separated, exhaust gas containing PCB is generated, Although it is trying to make it harmless by thermal decomposition, there is a problem that PCB and dioxins that may be by-produced cannot be sufficiently removed by simply decomposing at high temperature.
Further, since the copper coil is burned without being washed, there is a possibility that copper is recovered with the PCB attached.
[0008]
On the other hand, if the copper coil is to be washed, it takes several tens of hours because the PCB is soaked in the paper or wood used in the copper coil, which is not practical.
[0009]
Also, in the PCB combustion process, it is not possible to treat activated carbon used in the container storing the PCB, the PCB used for the treatment, waste white clay, waste waste, work clothes, and other PCB contaminants. There is a problem that it cannot be processed.
[0010]
In view of the above-described problems, the present invention provides a hazardous substance processing system capable of completely treating not only PCBs but also PCB contamination containers such as transformers contaminated with PCBs and PCB contaminants such as components thereof. Is an issue.
[0011]
[Means for Solving the Problems]
A first invention for solving the above-mentioned problems is a hazardous substance processing system for detoxifying a workpiece to which a hazardous substance is attached, contained or stored, and separating means for separating an organic halide from the workpiece. Cleaning means for cleaning the object to be processed from which the organic halide has been separated; hazardous substance decomposition treatment means for decomposing the separated organic halide; a cleaning waste liquid storage tank for storing cleaning waste liquid from the cleaning means; An organic halide storage tank for storing the separated organic halide, a return water storage tank for storing a part of the waste water from the hazardous substance decomposition treatment means as return water, the washing waste liquid storage tank, the organic halide storage tank, and with each measuring measuring means an organic halide concentration in the return water storage tank, the determination result from the organic halide supplied to the pollutant decomposition treatment means of the measuring means Ri Na and and a organic halide adjusting means for adjusting the concentration, the toxic substance decomposition treatment unit in the presence of sodium carbonate in the heating-pressurized reaction column (Na ₂ CO _3), an organic halide there dehalogenation reaction and sodium chloride by oxidative degradation (NaCl), the harmful material treatment system according to carbon dioxide (CO _2), wherein the hydrothermal oxidation decomposition apparatus der Rukoto to decompose the like.
[0012]
A second invention is the hazardous substance processing system according to the first invention, wherein the measuring means is an absorptiometer .
[0013]
A third invention is the hazardous substance processing system according to the second invention, wherein the absorptiometer is an ultraviolet / visible absorptiometer or an infrared absorption spectrometer.
[0014]
A fourth invention is characterized in that, in the third invention, the measurement wavelength of the ultraviolet / visible absorptiometer is 200 to 280 nm, or the measurement wavelength of the infrared absorption spectrometer is 600-1600 cm ^−1. In the hazardous material treatment system.
[0015]
A fifth invention is characterized in that, in any one of the first to fourth inventions, the object to be processed is a capacitor, a transformer, a fluorescent lamp ballast, or a component thereof containing a PCB-containing insulating oil. It is in the hazardous substance treatment system.
[0017]
According to a sixth invention, in the first invention, the hydrothermal oxidative decomposition apparatus includes a cylindrical primary reaction tower, an oil or an organic solvent, an organic halide, water (H ₂ O), and sodium hydroxide (NaOH). A pressurizing pump for pressurizing each of the treatment liquids, a preheater for preheating the water, a secondary reaction tower having a configuration in which a pipe is spirally wound, and a cooler for cooling the treatment liquid from the secondary reaction tower, The hazardous substance processing system includes gas-liquid separation means for gas-liquid separation of the processing liquid and a pressure reducing valve.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the hazardous substance processing system according to the present invention will be described below, but the present invention is not limited to these embodiments.
[0019]
[First Embodiment]
FIG. 1 shows an outline of a hazardous substance processing system.
As shown in FIG. 1, the hazardous substance processing system according to the present embodiment is a hazardous substance processing system for detoxifying an object (capacitor or the like) 1001 to which a hazardous substance (for example, PCB) is attached, contained or stored. The separation means 1004 for separating the organic halide (PCB liquid) 1002 from the object to be treated 1001, the washing means 1011 for washing the object 1003 from which the organic halide 1002 has been separated, and the separated organic halide. Toxic substance decomposition processing means 1013 for decomposing 1002, cleaning waste liquid storage tank 101 for storing cleaning waste liquid 1012 from cleaning means 1011, organic halide storage tank 102 for storing separated organic halide 1002 , and toxic substances A return water storage tank 103 for storing a part of the waste water 133 from the decomposition treatment means 1013; The washing liquid waste storage tank 101, is made by and a first to third measuring means 104-106 for each measuring organic halide concentration in the organic halide storage tank 102 and return water storage tank 103.
[0020]
In this embodiment mode, a capacitor is used as the workpiece 1001. The capacitor is a PCB solution having a PCB content of 100% and a high concentration.
[0021]
The said measuring means 104-106 takes out the stock solution in each tank 101-103 outside, and measures the light absorbency with an absorptiometer. Thereby, the density | concentration of the organic halide 1002 in each tank 101-103 is measurable. Based on the measurement result, adjustment of the organic halide supply is performed by the organic halide adjustment means (PCB adjustment means) 107 .
[0022]
That is, the concentration of the organic halide in the cleaning waste liquid storage tank 101 is ppm to several percent depending on the degree of contamination of the container cleaning, and the concentration of the organic halide in the organic halide storage tank 102 is 100% in the case of a capacitor. . Since the concentration of the organic halide in the return water storage tank 103 is several ppb to 10 ppb%, these concentrations are measured by the measuring means 104 to 106 and adjusted by the PCB adjusting means 107 to adjust the concentration of the organic halide. By making the PCB supply concentration constant to the harmful substance processing means 1013, the treatment by the harmful substance processing means 1013 can be always carried out satisfactorily and continuously.
[0023]
The absorption spectrophotometer is preferably used UV-Visible absorption photometer or an infrared absorption spectrometer, the although the measurement wavelength is not particularly limited, in the case of UV-Visible absorption photometer, 200 to 280 nm In the case of an infrared absorption spectrometer, it is preferably 600-1600 cm ⁻¹ . The main spectrum of the infrared absorption spectrum includes absorption due to stretching vibration of C—Cl (near 700 to 800 cm ⁻¹ ), C = C stretching vibration of aromatic hydrocarbons, absorption due to in-plane bending vibration of ring H ( 1000-1600 cm < ^-1 > vicinity).
[0024]
The object to be treated 1001 is not particularly limited, but is a capacitor, a transformer, a fluorescent light ballast, or a component of these containing a PCB-containing insulating oil, for example, a container after extracting the PCB and its The component is cleaned.
[0025]
Moreover, although the storage container which preserve | saves the coating material etc. which contain harmful substances, such as PCB, can be illustrated, for example, it is not limited to these.
[0026]
Here, in the present invention, the cleaning liquid is not particularly limited as long as it is a solvent having a function of cleaning and removing harmful substances such as PCB. For example, hexane, acetone, toluene, dichloromethane, benzene, octane, trichloroethylene, tetrachloroethylene , Hydrocarbons, chlorofluorocarbon alternatives, and the like.
[0027]
In the present invention, the hazardous substance decomposition treatment means 1013 is not particularly limited, but hydrothermal oxidation decomposition treatment means for hydrothermal oxidation decomposition treatment of PCB, which is an organic halide, or supercritical water oxidation treatment for supercritical water oxidation treatment. Examples of the treatment means and batch-type hydrothermal decomposition treatment means may be mentioned, but the present invention is not limited to these as long as the harmful substances can be decomposed by a known harmful substance treatment means.
As the harmful substance decomposition treatment means 1013, a continuous treatment method and a batch treatment method can be appropriately employed.
In the case where continuous complete decomposition is performed, it is preferable to use hydrothermal oxidative decomposition treatment means.
[0028]
FIG. 3 shows an outline of the hydrothermal decomposition apparatus 120. As shown in FIG. 3, a cylindrical primary reaction tower 122 provided with a cyclone separator 121 and oil (or organic solvent), PCB, water (H ₂ O), and sodium hydroxide (NaOH) treatment liquids 123a to 123a. A pressurizing pump 124 for pressurizing 123d, a heat exchanger 125 for preheating the water, a mixer 101 for mixing sodium hydroxide 123c and water 123d in front of the heat exchanger 125, and a pipe spirally A secondary reaction tower 126 having a configuration wound around or a cylindrical configuration, a cooler 127, and a pressure reducing valve 128 are provided. Further, a gas-liquid separator 129 and an activated carbon tank 130 are disposed downstream of the pressure reducing valve 127, exhaust gas (CO ₂ ) 131 is exhausted from the chimney 132, and drainage (H ₂ O, NaCl) 133 is It is stored in the discharge tank 134 and is drained separately if necessary.
[0029]
The processing liquids 123a to 123d of oil (or organic solvent), PCB, H ₂ O, and NaOH to be the processing liquid 123 are introduced from the processing liquid tanks 135a to 135d through the pipes 136a to 136d and the ejector 137, respectively. In this embodiment, the sodium hydroxide 123c is mixed with the supply water 123d in advance by the mixer 101 and then supplied to the heat exchanger 125.
Thereby, since the high alkali liquid of sodium hydroxide is not directly charged into the primary reaction tower 122, corrosion due to the high alkali can be prevented.
Moreover, the boiling point rises due to the alkali addition effect on the feed water 123d, and the feed water temperature in the heat exchanger 125 can be raised.
[0030]
Further, an oxidizing agent such as oxygen (O ₂ ) is supplied by a high-pressure oxygen supply facility 138, and the supply pipe 139 is directly connected to the primary reaction tower 122. The reason why oil (or an organic solvent) is added is to promote the decomposition reaction of particularly high concentration PCB and to raise the reaction temperature to the optimum temperature when the decomposition apparatus 120 is started. Further, the PCB, H ₂ O and NaOH may be further mixed as the treatment liquid and charged into the primary reaction tower 122.
[0031]
In the above apparatus, the pressure in the primary reaction tower 122 is increased to 26 MPa by pressurization by the pressure pump 124. The heat exchanger 125 preheats H ₂ O mixed with sodium hydroxide to 300 ° C. or higher.
Further, oxygen is spouted into the primary reaction tower 122, and the temperature is raised to 380 ° C. to 400 ° C. by the internal reaction heat. The cyclone separator 121 separates large Na ₂ CO ₃ crystal particles precipitated in the primary reaction tower 122 and sends Na ₂ CO ₃ fine particles to the secondary reaction tower 126. The action of the cyclone separator 121 prevents the secondary reaction tower 126 from being blocked. By this stage, PCB has been dechlorinated and oxidatively decomposed and decomposed into NaCl, CO ₂ and H ₂ O. Next, in the cooler 127, the fluid from the secondary reaction tower 126 is cooled to about 100 ° C. and the pressure is reduced to atmospheric pressure by the pressure reducing valve 128 at the subsequent stage. Then, CO ₂ and water vapor and the treatment liquid are separated by the gas-liquid separator 129, and the CO ₂ and water vapor pass through the activated carbon tank 130 and are discharged into the environment.
In addition, you may make it provide the cyclone separator 121 as needed.
[0032]
By processing such a processing apparatus 120 PCB-containing oil with a (for example, an insulating oil such as transformer and a capacitor) and the like, and the residue, PCB is de-chlorinated biphenyls ((C ₆ H _{5) 2)} removal of such A chlorinated product is used, and the biphenyl is completely detoxified into CO ₂ , H ₂ O, and the like by the action of an oxidizing agent or the like.
[0033]
In addition, the PCB concentration in each of the tanks 101 to 103 is measured using the first to third measuring means 104 to 106, and the result is adjusted by the PCB adjusting means 107, whereby the decomposition in the hydrothermal oxidative decomposition apparatus 120 is performed. Processing can be continuously performed over a long period of time without additional processing.
Further, a measuring device 108 that measures in advance the PCB concentration in the processing liquid from the cooler 127 may be provided.
[0034]
[Second Embodiment]
FIG. 2 shows an outline of the hazardous substance processing system.
As shown in FIG. 2, hazardous material treatment system according to this embodiment, in the processing system shown in FIG. 1, it is provided a reproducing unit 110 for reproducing processing contaminated washing liquid (washing liquid waste) 1012, contaminated cleaning solution 1012 Is intended for recycling. Accordingly, the cleaning liquid can be reused by the regenerating means 110 of the contaminated cleaning liquid 1012 and the residue 112 including the PCB from the regenerating means 110 is sent into the cleaning waste liquid storage tank 101. The PCB concentration can be measured by the first measuring means 104 for measuring the PCB concentration, and the supply at a constant PCB concentration is always maintained to the hydrothermal oxidative decomposition apparatus 120 by adjusting the PCB adjusting means 107. be able to.
[0035]
Examples of the concentration means 111 include a desalting means for desalting NaCl in the waste water 133.
Examples of the desalting means include a reverse osmosis membrane device, an electrolysis device, an electrodialysis device, and the like.
[0036]
【The invention's effect】
As described above, according to the present invention, there is provided a hazardous substance processing system for detoxifying a workpiece to which a hazardous substance is attached, contained or stored, and separating organic halides from the workpiece. Cleaning means for cleaning the object to be processed from which the organic halide has been separated, hazardous substance decomposition processing means for decomposing the separated organic halide, and a cleaning waste liquid storage tank for storing cleaning waste liquid from the cleaning means, An organic halide storage tank for storing the separated organic halide, a return water storage tank for storing a part of the wastewater from the hazardous substance decomposition treatment means as return water, the washing waste liquid storage tank, and the organic halide storage tank. and measuring means for each measuring organic halide concentration in the return water storage tank, from the determination result of the measuring means, organohalogen supplied to the pollutant decomposition treatment unit Ri Na and and a organic halide adjusting means for adjusting the object density, the toxic substance decomposition treatment unit in the presence of sodium carbonate in the heating-pressurized reaction column (Na ₂ CO _3), organohalogen Since the hydrothermal oxidative decomposition apparatus decomposes into sodium chloride (NaCl), carbon dioxide (CO ₂ ), etc. by dehalogenation reaction and oxidative decomposition reaction of the halide, measurement of organic halide (for example, PCB concentration) in each tank This makes it possible to maintain and manage the overall treatment concentration of the organic halide supplied to the hazardous substance decomposition treatment means. As a result, the decomposition reaction in the decomposition processing means can be optimized.
[0037]
For example, the PCB concentration can be measured for PCB feed liquids with different liquids such as PCB stock solution, cleaning waste liquid, cleaning waste liquid concentrate, waste water, etc., so that the concentration control of organic halides supplied to the hazardous substance decomposition treatment means can be performed by adjusting means. It becomes.
[Brief description of the drawings]
FIG. 1 is a schematic view of a hazardous substance processing system according to a first embodiment.
FIG. 2 is a schematic view of a hazardous substance processing system according to a second embodiment.
FIG. 3 is a schematic view of a hydrothermal oxidative decomposition apparatus.
FIG. 4 is a flowchart of a PCB processing method according to the prior art.
[Explanation of symbols]
1001 Object 1002 Organic halide (PCB liquid)
1003 Container 1004 Separating means 1011 Cleaning means 1013 Hazardous substance decomposition processing means 101 Washing waste liquid storage tank 102 Organic halide storage tank 103 Return water storage tank 104 First measuring means 105 Second measuring means 106 Third measuring means 110 Regenerating means 122 Primary Reactors 123a to 123d Treatment liquids 124a to 124d Pressure pump 125 Heat exchanger 126 Secondary reactor 127 Cooler 128 Pressure reducing valve 129 Gas-liquid separator 130 Activated carbon tank 131 Exhaust gas (CO ₂ )
132 Chimney 133 Drainage (H ₂ O, NaCl)
134 Discharge tanks 135a to 135d Treatment liquid tanks 136a to 136d Pipe 137 Ejector 138 High pressure oxygen supply equipment

Claims (6)

A hazardous substance processing system for detoxifying a workpiece to which harmful substances are attached, contained or stored,
Separation means for separating the organic halide from the object to be treated;
Cleaning means for cleaning the object to be processed from which the organic halide has been separated;
A hazardous substance decomposition treatment means for decomposing the separated organic halide;
A cleaning waste liquid storage tank for storing cleaning waste liquid from the cleaning means;
An organic halide storage tank for storing the separated organic halide;
A return water storage tank for storing a part of the wastewater from the hazardous substance decomposition treatment means as return water;
Measuring means for measuring the organic halide concentration in the washing waste liquid storage tank, the organic halide storage tank and the return water storage tank, respectively.
Than the determination result of the measuring means, Ri Na and and a organic halide adjusting means for adjusting the concentration of organic halides supplied to the pollutant decomposition treatment unit,
In the presence of sodium carbonate (Na ₂ CO ₃ ) in the heated and pressurized reaction tower, the above hazardous substance decomposition treatment means performs dehalogenation reaction and oxidative decomposition reaction of organic halides to produce sodium chloride (NaCl), dioxide dioxide. hazardous material treatment system according to claim carbon (CO ₂₎ hydrothermal oxidation decomposition apparatus der to degrade Ru things like. In claim 1,
A hazardous substance processing system, wherein the measuring means is an absorptiometer . In claim 2 ,
The hazardous substance processing system, wherein the absorptiometer is an ultraviolet / visible absorptiometer or an infrared absorption spectrometer. In claim 3 ,
Hazardous material treatment system, wherein the measurement wavelength of the ultraviolet-visible absorption spectrophotometer is 200 to 280 nm, or, the measurement wavelength of the infrared absorption spectrometer is 600-1600cm ^-1. In any one of Claims 1 thru | or 4 ,
A hazardous substance treatment system, wherein the object to be treated is a capacitor, a transformer, a fluorescent light ballast or a component thereof containing a PCB-containing insulating oil. In claim 1 ,
The hydrothermal oxidative decomposition apparatus is
A cylindrical primary reaction tower;
A pressure pump for pressurizing each treatment liquid of oil or organic solvent, organic halide, water (H ₂ O) and sodium hydroxide (NaOH);
A preheater for preheating the water;
A secondary reaction tower having a configuration in which pipes are spirally wound;
A cooler for cooling the treatment liquid from the secondary reaction tower;
Gas-liquid separation means for gas-liquid separation of the treatment liquid;
A hazardous substance processing system comprising: a pressure reducing valve.

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