JP2010269283A - Method and system for detoxifying apparatus using pcb - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a system for simply detoxifying, in a short period of time, PCB residues in a container and an internal member constituting an electric apparatus without by-producing harmful dioxins after removal of PCB from the electric apparatus and for enhancing energy efficiency of and industrial economy of the PCB detoxification. <P>SOLUTION: The system for detoxifying the apparatus using PCB for decomposing PCB residues in the container and the internal member constituting the electric apparatus after removal of PCB from the electric apparatus includes a catalyst filling device 4, a catalyst vessel 3 housing the catalyst filling device, a microwave device 12 irradiating the catalyst filling device with microwaves, a heat insulation device 15 for the container, a cooler 13 for a mixed liquid taken out from the container, a heater 14 for the mixed liquid returned to the container, a heat pump 16 moving the heat of cooling water used for the cooler to warm water used for the heater and circulating flow passages 17-20 circulating the mixed liquid. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a detoxification processing method and a detoxification processing system for a device using PCB. Specifically, after extracting the PCB from an electrical device such as a transformer in which the PCB is used, a detoxification processing method for efficiently and efficiently decomposing the PCB remaining in the container and the internal member constituting the device. And a detoxification processing system.

  Among various organic halogen compounds, polychlorinated biphenyl (hereinafter abbreviated as “PCB”) is extremely harmful to living organisms including the human body. Therefore, it was designated as a specified chemical substance in 1973 and its manufacture, import and use are prohibited. Has been. However, after that, tens of thousands of tons of PCBs are left untreated without determining an appropriate disposal method. PCBs are technically difficult to decompose PCBs for many years because PCBs are by-produced by chlorinated dibenzo-p-dioxin (PCDD) and dibenzofuran (PCDF), which are highly toxic dioxins in high temperature decomposition. Various safe and efficient decomposition methods have been studied.

  In the case of electrical equipment such as transformers, it is difficult to completely extract the built-in insulating oil, and the insulating oil remains in the equipment even after the insulating oil containing PCB is extracted. It becomes. A method of decomposing and detoxifying the remaining PCB has been proposed for equipment using insulating oil containing PCB.

  In Patent Document 1, after extracting the PCB-containing insulating oil filled in the device, the device is roughly cleaned with regenerated insulating oil, the step of cleaning with a final cleaning solution, and the cleaning solution is dechlorinated with metallic sodium. A detoxification processing technique having a process for converting into a non-toxic state has been proposed. However, with this method, it is necessary to treat a large amount of waste liquid that includes both the regenerated insulating oil used for rough cleaning and the cleaning liquid used for finish cleaning. Therefore, PCB remaining in the equipment is efficiently decomposed. This is not a detoxifying treatment method. Further, in the case of a device having a complicated internal member, the insulating oil containing PCB soaks into the material such as insulating paper and wood pieces constituting the internal member, and the remaining PCB is effectively removed only by cleaning. It also has the problem that it is difficult.

  In Patent Document 2, a stationary induction machine containing an organic halogen compound is placed in a pressure vessel together with water and an oxidant, and the water in the pressure vessel is brought into a supercritical state by pressurization and heating to decompose the organic halogen compound. A detoxifying treatment method has been proposed. However, this method decomposes an organic halogen compound under conditions of high temperature (430 ° C.) and high pressure (25 MPa), and it is not a simple method because it requires a large apparatus. Since a large amount of energy is required to maintain the high pressure condition, this is not an energy saving method.

  In Patent Document 3, a solution containing isopropyl alcohol and KOH is filled in a device after extracting an insulating oil containing PCB, and a mixed solution is prepared by eluting the insulating oil containing PCB, and the mixed solution Is circulated through a catalyst filling device having a structure in which the catalyst is heated by intermittently irradiating microwaves, and then returned to the device to circulate between the device and the catalyst filling device. Detoxification methods that dissolve and dissolve until graduation criteria are met have been reported. However, in this method, if the microwave irradiation amount is increased in order to increase the activity of the catalyst, the temperature of the mixed solution becomes too high and dioxins are easily produced as a by-product, so the microwave irradiation amount must be limited. There is a problem that the PCB cannot be efficiently decomposed.

  Further, in the method of Patent Document 3, when PCB and mineral oil-based insulating oil are mixed, that is, when PCB is present in a state of being dissolved in mineral oil, by filling a solution composed of isopropyl alcohol and KOH, PCB remaining in the device and its internal components can be eluted with mineral oil relatively efficiently. However, in the case of equipment using insulating oil consisting of PCB alone, it is presumed that PCB has higher viscosity than mineral oil, but PCB soaked in insulating paper and wood chips that constitute internal members is eluted. In particular, it is necessary to circulate the liquid over a long period of time in a cold region or in winter, and there is a problem that the remaining PCB cannot be decomposed efficiently.

  Therefore, in equipment using insulating oil containing PCB, in particular, insulating oil consisting of PCB, after extracting PCB, there is a demand for a processing method for efficiently and energy-efficiently decomposing PCB remaining in the equipment and its internal members. It was.

JP 2004-008842 A JP 2000-116814 A JP 2009-011848 A

  The present invention has been made in view of the above-mentioned problems, and after removing the PCB from the electrical equipment using the PCB, the PCB remaining in the container and the internal member constituting the equipment is specially detoxified. The purpose of the present invention is to carry out a detoxification treatment simply and efficiently without using dioxins and without producing dioxins as a by-product.

  In order to solve the above-described problems, the present invention employs a detoxification processing method and a detoxification processing system for a PCB-using device having the following configuration.

(1) For a device using PCB, in a detoxification treatment method for decomposing PCB remaining in a container and an internal member after the PCB is extracted,
The container is filled with a solution composed of a hydrogen donor and an alkali compound and heated to elute PCB to form a mixed solution, and then a part of the mixed solution is taken out to prepare a catalyst filling device in the catalyst tank. The detoxification treatment method of decomposing the remaining PCB by irradiating the mixed solution circulating through the catalyst filling device with microwaves while returning to the container after circulating the
Heat retaining means for retaining the container;
A cooling means for cooling the mixed liquid to be circulated through the catalyst filling device, and
A heating means for heating the mixed liquid that returns the catalyst filling device to the container after distribution is provided,
A detoxifying treatment method for equipment using PCB, wherein the heat taken out by the cooling means is moved to the heating means by a heat pump.
(2) The method for detoxifying a PCB-using device according to (1), wherein the device is one of a pole transformer, a large transformer, or an oil tank of an oil insulated cable.
(3) The method for detoxifying a PCB-using device according to (1) or (2), wherein the microwave output is controlled by PID control of a temperature controller.
(4) The method for detoxifying a device using PCB according to any one of (1) to (3), wherein the hydrogen donor is isopropyl alcohol.
(5) The method for detoxifying PCB-using equipment according to any one of (1) to (4), wherein the alkali compound is at least one compound selected from caustic soda and caustic potash.
(6) The detoxification method for PCB-using equipment according to any one of (1) to (5), wherein the catalyst used in the catalyst filling device is a metal-supported carbon compound.

(7) A member in which PCB remains is placed in a container, and further, a solution comprising a hydrogen donor and an alkali compound is filled and heated to elute PCB to obtain a mixed solution, and then a part of the mixed solution The catalyst filling device in the catalyst tank is circulated and returned to the container to circulate the mixed solution, and the mixed solution flowing through the catalyst filling device is irradiated with microwaves to A detoxification method for decomposing residual PCB,
Heat retaining means for retaining the container;
A cooling means for cooling the mixed liquid to be circulated through the catalyst filling device, and
A heating means for heating the mixed liquid returning to the container after distribution through the catalyst filling device is provided,
A method for detoxifying a PCB residual member, wherein the heat taken out by the cooling means is moved to the heating means by a heat pump.
(8) The detoxification method according to (7), wherein the member is an iron core, a copper coil, an insulator, or insulating paper.

(9) For a device using a PCB, after extracting the PCB, the container constituting the device is filled with a solution composed of a hydrogen donor and an alkali compound and heated to elute the PCB, After that, a part of the mixed solution is taken out, circulated through the catalyst filling device in the catalyst tank, returned to the container, and the mixed solution is circulated to remain in the container and the internal member constituting the device. A detoxification processing system for disassembling a PCB,
A heat retaining device for retaining the container;
A catalyst filling device;
A catalyst tank containing the catalyst filling device;
A microwave device for irradiating the catalyst filling device with microwaves;
A cooler provided in a flow path for taking out the liquid mixture in the vessel and introducing it into the catalyst tank;
A heater provided in a flow path for returning the mixed liquid flowing through the catalyst tank to the container;
A heat pump that moves the heat extracted by the cooling water circulating through the cooler to the hot water circulating through the heater;
A detoxification processing system for PCB-use equipment, comprising:
(10) The PCB-using equipment detoxification processing system according to (9), wherein the equipment is one of a pole transformer, a large transformer, or an oil tank of an oil insulated cable.
(11) The PCB-using device detoxification processing system according to (9) or (10), wherein the microwave device includes a temperature controller that measures the temperature of the mixed solution and performs PID control.
(12) The detoxification processing system for PCB-using equipment according to any one of (9) to (11), wherein the hydrogen donor is isopropyl alcohol.
(13) The detoxification processing system for PCB-using equipment according to any one of (9) to (12), wherein the alkali compound is at least one compound selected from caustic soda and caustic potash.
(14) The detoxification processing system for PCB-using equipment according to any one of (9) to (13), wherein the catalyst used in the catalyst filling device is a metal-supported carbon compound.

  According to the detoxification treatment method and the detoxification treatment system according to the present invention, after extracting the PCB from the equipment using the PCB, the container constituting the equipment is filled with a solution comprising a hydrogen donor and an alkali compound, The remaining PCB is eluted to prepare a mixture. By heating the mixed solution at the time of preparing the mixed solution, elution of the remaining PCB can be promoted. Then, by cooling the mixed solution before passing it through the catalyst filling device, it is possible to increase the amount of microwave irradiation to the catalyst filling device and promote the decomposition of the PCB, so that the PCB is efficiently decomposed in a short period of time. It becomes possible.

  In the present invention, the heat obtained by the cooling water used for cooling the mixed liquid to be circulated through the catalyst filling device is taken out using a heat pump, and the mixed liquid after circulation through the catalyst filling device is heated. Use. The mixed liquid after passing through the catalyst filling device is heated by microwave irradiation, but is further heated and returned to the container to compensate for the heat lost from the container due to heat dissipation and to keep the mixed liquid in the container warm. By doing so, elution of PCB can be continuously promoted, and energy saving as the whole system can be achieved. In particular, the present invention is effective in cold districts, winter seasons, and the like where a large amount of heat is dissipated from containers and piping.

  Furthermore, if the microwave device includes a temperature controller, the microwave irradiation amount can be increased and leveled by PID control.

  If there is a member that does not satisfy the predetermined processing standard value after the detoxification process is performed and the device is disassembled, the PCB remains by putting the member in a container and performing the detoxification process of the present invention. The member can be easily detoxified in a short period of time while saving energy. The member detoxification treatment can be carried out using a separate container, but can also be carried out using a container constituting the apparatus, and is economical in that no special container is required.

1 is a system configuration diagram of a detoxification processing system of the present invention. It is a figure which shows the outline of the heat pump in the detoxification processing system of this invention. It is the graph which showed an example of the density | concentration change at the time of PCB detoxification process.

  Hereinafter, a detoxification processing method and a detoxification processing system for a PCB-using device according to the present invention will be described in detail with reference to the drawings.

  Examples of the electrical equipment to which the detoxification treatment method and the detoxification treatment system of the present invention can be applied include a transformer (on a pillar, large size), an oil tank of an oil insulated cable, and the like. In particular, the pole transformer has various internal members with a structure embedded in the interior, and PCB may be infiltrated into materials such as insulating paper and wooden frames constituting these internal members. The detoxification processing method and the detoxification processing system of the present invention are preferably used. Here, the large transformer refers to a transformer having an insulating oil capacity of 100L to 300,000L.

  Examples of the PCB to be detoxified according to the present invention include polychlorinated biphenyls (PCBs), dioxins and the like, and the type is not particularly limited, but PCBs are preferred. is there. PCBs include PCBs containing dioxins. Examples of commercially available PCBs include KC-200 (main component: biphenyl dichloride), KC-300 (main component: biphenyl trichloride), KC-400 (main component: tetrachloride) manufactured by Kaneka Chemical Co., Ltd. Biphenyl), KC-500 (main component: biphenyl pentachloride), KC-600 (main component: biphenyl bichloride), Arocrol 1254 (54% Chlorine) manufactured by Mitsubishi Monsite Corporation, and the like.

  FIG. 1 is a system configuration diagram of a detoxification processing system according to the present invention, and shows an example of detoxifying PCB remaining in a container 1 and an internal member 21 of an electrical device having internal members.

  In the detoxification treatment method of the present invention, in the detoxification treatment method for decomposing PCB remaining in the container and the internal member of the equipment using the PCB after extracting the PCB, the container 1 is supplied with hydrogen. After filling a solution composed of a solid body and an alkali compound and eluting PCB to make a mixed solution 2, a part of the mixed solution 2 is taken out and circulated through a catalyst filling device 4 arranged at the upper part in the catalyst tank 3. The mixture is stored in the liquid reservoir 5 at the lower part of the catalyst tank, and then returned to the container 1 to circulate the mixed solution. At the same time, the microwave is applied to the mixed solution flowing through the catalyst filling device 4 from the microwave device 12. The PCB contained in the mixed solution is decomposed.

  The container 1 is provided with a heat retaining device 15 that can be heated as necessary, and the liquid mixture 2 taken out from the container is circulated to the catalyst filling device in the take-out side flow path of the container 1. Before, a cooler 13 for cooling the mixed liquid is provided, and a heater 14 for heating the mixed liquid returned to the container after flowing through the catalyst filling device is provided in the return side flow path of the container 1. . Furthermore, a heat pump 16 schematically shown in FIG. 2 is installed between the cooler and the heater, and the heat obtained by cooling the mixed liquid by the cooling water used in the cooler is obtained using the heat pump. The mixture is transferred to the warm water of the heater and used to heat the mixed liquid returned to the container.

  Therefore, in the detoxification treatment method of the present invention, since the mixed solution in the container 1 is in a heated state, elution of PCB remaining in the container and the internal member is promoted. And since the liquid mixture which distribute | circulates a catalyst filling apparatus is cooled, it becomes possible to increase a microwave irradiation amount, can accelerate | stimulate decomposition | disassembly of PCB by a catalyst, and shorten the time required for decomposition | disassembly of PCB significantly. It becomes possible. Moreover, as a heat source necessary for heating the liquid mixture in the container, the heat released when the liquid mixture is cooled is recovered and used by a heat pump, so that the liquid mixture in the container is simply heated. Compared to the case, energy efficiency is also good.

  The detoxification processing system of the present invention includes a catalyst filling device 4, a catalyst tank 3 that accommodates the catalyst filling device 4, a microwave device 12 for irradiating the catalyst filling device 4 with microwaves, A cooler 13 provided in the take-out side flow path of the container, a heater 14 provided in the return-side flow path of the container, a heat retaining device 15 capable of heating the container as required, a heat pump 16, and the container And a circulation channel (pipe 17 to 20) for circulating the mixed liquid therein through the cooler 13, the catalyst filling device 4 and the heater 15. The detoxification processing system of the present invention is a system suitable for implementing the detoxification processing method of the present invention.

(Embodiment 1)
In the detoxification treatment method and system according to the embodiment of the present invention shown in FIG. 1, the PCB is extracted from the electrical equipment using the PCB, and the extracted container 1 is filled with a solution comprising a hydrogen donor and an alkali compound. To do. The method of extracting the PCB is arbitrary, such as a method of flowing down from the opening of the electric device, a method of sucking out by a pump or the like.

  The alkali compound is added in an amount described later with respect to the hydrogen donor. After filling, in order to elute the remaining PCB into the solution, the inside of the container may be stirred and mixed as necessary, or may be left in a filled state. The filling amount is preferably such that the inner member of the container is immersed, and as shown in FIG. 1, the liquid level after filling the pole transformer (container) 1 is installed in the pole transformer. Higher than the inner member (coil) 21 made.

  It is preferable to use a solution in which the concentration of the alkali compound relative to the total mass of the hydrogen donor and the alkali compound is in the range of 0.1 to 20% by mass and the alkali compound is dissolved in the hydrogen donor in advance. If the amount of the alkali compound added to the hydrogen donor is too small, the PCB decomposition reaction will hardly proceed, and if it is too much, the decomposition reaction will no longer be promoted, resulting in poor economic efficiency.

  By filling the container 1 with the solution, the PCB remaining on the inner surface and the internal member of the container is gradually eluted, so that the remaining PCB is eluted to some extent to form a mixed solution. Use for detoxification treatment. In the present invention, the container 1 is provided with a heat retaining device, and it is preferable to warm the solution after filling to promote the elution of PCB. Although the heating temperature of a solution is not specifically limited, The range of 40-55 degreeC is preferable.

  The heat retaining device 15 of the container 1 is not particularly limited as long as it can be heated as necessary. For example, a ribbon heater or the like is wound around the outer periphery of the container 1 and the outside is a heat insulating material made of glass wool or foam. A covered, simple device or the like can be used. By using such a heat retaining device 15, the liquid mixture in the container can be heated, and after the liquid mixture reaches a predetermined temperature, the temperature of the liquid mixture can be maintained simply by stopping heating and keeping the temperature. It becomes possible to do.

  The time required for the preparation of the mixed solution is not particularly limited, and is one day to several weeks. The shorter the adjustment time of the mixed liquid, the better from the viewpoint of shortening the detoxification treatment time, so when the outside air temperature is low such as in winter and it takes a long time to heat the mixed liquid, the temperature of the mixed liquid is Even if the temperature does not rise to the above temperature, it is preferable to start the circulation of the mixed solution to the catalyst filling device and irradiate the microwave to perform the decomposition reaction of the PCB. By irradiating the microwave, the mixed liquid flowing through the catalyst filling device is heated. Therefore, the heated mixed liquid is circulated through the container, thereby promoting the heating of the mixed liquid in the container and remaining PCB. The time required for the detoxification treatment can be shortened as a whole by promoting the elution of selenium.

  Here, examples of the “hydrogen donor” used in the present invention include heterocyclic compounds, amine compounds, alcohol compounds, ketone compounds, and alicyclic compounds. Among these compounds, alcohol compounds, ketone compounds, and alicyclic compounds are preferable from the viewpoint of safety. In particular, they are highly safe, can be obtained at low cost, and reaction control is easy. From the viewpoint of high decomposition efficiency, alcohol compounds are preferred. These hydrogen donors may be used alone or in any combination of two or more.

  The alcohol compound may be any of aliphatic alcohol and aromatic alcohol. Specifically, methanol, ethanol, 1-propanol, 2-propanol, n-butanol, s-butanol, t- Butanol, 1-pentanol, 2-pentanol, 3-pentanol, 1-hexanol, 2-hexanol, 3-hexanol, 1-heptanol, 2-heptanol, 3-heptanol, 1-octanol, 2-octanol, etc. Aliphatic alcohols such as aliphatic alcohol, cyclopropyl alcohol, cyclobutyl alcohol, cyclopentyl alcohol, cyclohexyl alcohol, cycloheptyl alcohol, cyclooctyl alcohol, ethylene glycol, propylene glycol, decalin diol, etc. Polyhydric alcohol, and the like. Among these, 2-propanol and cyclohexanol are preferable from the viewpoint of decomposition efficiency, and 2-propanol is particularly preferable.

  The alkali compound is not limited as long as it can accelerate the dehalogenation reaction of PCB, but caustic soda, caustic potash, sodium alkoxide, potassium alkoxide, calcium hydroxide, and the like are preferable from the viewpoint of increasing dehalogenation efficiency. Used. Caustic soda and caustic potash are particularly preferred from the viewpoint of cost and handling properties. The alkali compounds may be used alone or in any combination of two or more.

  Next, a part of the prepared mixed liquid is taken out from the container 1, passed through the catalyst filling device 4 arranged at the upper part in the catalyst tank 3, stored in the liquid reservoir 5 at the lower part of the catalyst tank, and then returned to the container 1. Then, the mixed solution is circulated, and the mixed solution flowing through the catalyst filling device 4 is irradiated with microwaves from the microwave device 12 to decompose the remaining PCB. At this time, a cooler 13 is provided in the take-out side flow path, and the mixed liquid taken out from the container is cooled before being circulated to the catalyst filling device. Further, a heater 14 is provided in the return side flow path for returning the mixed liquid from the catalyst tank 3 to the container, and a heat pump 16 is installed between the cooler 13 and the heater 14. Using this heat pump 16, the heat obtained by cooling water used in the cooler 13 by cooling the mixed liquid is transferred to hot water used in the heater 14, and the mixed liquid is heated by the heater 14. By returning to the container 1 after that, the heat lost by the heat radiation from the container or piping is compensated.

  After the mixed liquid is circulated through the catalyst filling device and PCB decomposition is started, elution of the PCB is promoted by maintaining the mixed liquid in the container 1 at a predetermined temperature. From the viewpoint of promoting the dissolution of PCB, it is preferable that the temperature is high. On the other hand, if the temperature of the mixed liquid in the container is too high, a large load is applied to the cooling before the mixed liquid is circulated through the catalyst filling device. It is preferable to set the temperature to be about 5 to 10 ° C. lower than the reaction temperature described later. When the reaction temperature is 60 ° C, the most preferable temperature is 50 to 55 ° C.

  In the detoxification method of the present invention, when the mixed solution is circulated through the catalyst filling device 4, microwaves are irradiated to heat the catalyst and promote PCB decomposition. At this time, the mixed solution is also heated at the same time. The The temperature of the mixed solution (that is, the reaction temperature) is preferably higher from the viewpoint of the decomposition rate of PCB, but is preferably as low as possible in order to suppress the formation of by-products such as dioxins. The temperature is normal temperature or higher and 100 ° C. or lower. Preferably it is the range of 40-80 degreeC, and the most preferable temperature is 60 degreeC. When the reaction temperature exceeds 100 ° C., the dehalogenation reaction proceeds sufficiently, but it is not preferable because by-products are easily generated.

  In the present invention, when the mixed liquid 2 taken out from the container 1 is circulated through the catalyst filling device 4, it is first introduced into the cooler 13 through the pipe 17, cooled to a predetermined temperature, and then through the pipe 18. Then, the catalyst is introduced into the upper part of the catalyst filling device 4 through an inlet provided in the upper part of the catalyst tank 3. Here, the predetermined temperature is preferably set to a temperature lower by about 20 to 40 ° C. than the above reaction temperature. That is, when the reaction temperature is 60 ° C., the mixed solution is preferably cooled to 20 to 40 ° C. and then introduced into the catalyst filling device. This is because, by lowering the temperature of the mixed liquid introduced into the catalyst filling device, it is possible to increase the intensity of the microwave to be irradiated and the irradiation time, and to promote the decomposition of the PCB. However, the cooling to a temperature lower than the above is because the time required for cooling becomes long, so the amount of the mixed liquid introduced into the cooler cannot be increased, and the amount of the mixed liquid flowing through the catalyst filling device decreases. Since it takes a long time to return to the detoxification process, it is not preferable.

  The cooler 13 is a device provided with a cooling coil or the like in which the cooling water is circulated through the heat pump 16 although it is provided in the take-out side flow path of the container 1 so that the mixed liquid flowing through the catalyst filling device 4 can be cooled. It is. The cooling water introduced from the inlet of the cooling coil of the cooler 13 exchanges heat with the liquid mixture via the cooling coil in the cooler, cools the liquid mixture, and heats the cooling water itself. The heated cooling water discharged from the outlet of the cooling coil is introduced into the heat pump, cooled by exchanging heat with the refrigerant in the heat pump, and returned to the inlet of the cooling coil.

  On the other hand, the mixed liquid 2 flowing through the catalyst filling device 4 continuously flows through the catalyst layer, and the mixed liquid 2 after flowing through the catalyst layer flows down from the bottom of the catalyst filling device 4. Since the liquid level in the catalyst filling device is always kept high, the mixed liquid flowing down from the bottom of the catalyst filling device overflows into the catalyst tank 3 containing the catalyst filling device 4 via the side pipe 7. The liquid is poured into the liquid reservoir 5 at the bottom of the catalyst tank 3. The arrows in FIG. 1 indicate the general flow direction of the mixed liquid flowing through the catalyst filling device.

  The catalyst tank 3 is configured so that the catalyst filling device 4 is accommodated in the upper part of the inside thereof, and the mixed liquid flowing through the catalyst filling device 4 can be stored in the bottom part of the catalyst tank. ) Is provided with an outlet 3 a for taking out the mixed liquid and returning it to the container 1. The stored mixed liquid 2 is taken out from the outlet 3 a of the catalyst tank, introduced into the heater 14 through the pipe 19, heated, and then returned to the container 1 through the pipe 20.

  The heater 14 is a device in which a heating coil or the like through which the hot water circulates via the heat pump 16 is arranged, and the hot water introduced from the inlet of the heating coil of the heater 14 exchanges heat with the liquid mixture via the heating coil. While heating the liquid mixture, the hot water itself is cooled. The cooled hot water is introduced into the heat pump, heated by the heat received by the refrigerant of the heat pump from the cooling water, and returned to the inlet of the heating coil.

  An outline of the heat pump 16 used in the present invention is shown in FIG. The cooling water heated by cooling the liquid mixture in the cooler 13 exchanges heat with the refrigerant in the refrigerant vaporizer in the heat pump, the cooling water is cooled, and the refrigerant is heated. The heated and vaporized refrigerant is further heated by being compressed by the compressor in the heat pump, and then exchanges heat with the hot water discharged from the heating coil of the heater 14, the hot water is heated, and the refrigerant is cooled. Liquefy. The liquefied refrigerant is expanded and cooled by passing through the expander in the heat pump, returns to the refrigerant vaporizer, and is again used for heat exchange with the cooling water.

  Heating of the mixed solution in the heater 14 with warm water heated by a heat pump is performed so as to be about 5 to 20 ° C. higher than the heat retaining temperature of the mixed solution in the container 1. Thereby, the heat lost by heat radiation can be compensated, the temperature of the liquid mixture in the container 1 can be maintained, and the elution of PCB can be continuously promoted.

  Although the method of heating the container 1 directly with the warm water heated by the heat pump and keeping the mixed solution is also conceivable, in the present invention, the container 1 uses a container itself constituting a device such as a columnar transformer. In the case of equipment, if a hot water bath or the like that can heat these equipment is installed separately, the equipment becomes large, and thus a simple harmless treatment system cannot be obtained. On the other hand, in the present invention, as described above, since the mixed liquid returning from the catalyst filling device to the container is further heated and used for the heat insulation of the mixed liquid in the container, the heat retaining can be performed easily and effectively. can do.

As described above, by using the heat released by cooling the mixed solution for heating the mixed solution via the heat pump, it is possible to effectively use the energy of the entire system.
In other words, when cooling the mixed liquid to be circulated through the catalyst filling device and keeping the temperature of the mixed liquid in the container are performed independently of each other, the energy required for cooling is discarded without being used. In contrast, in the present invention, although energy is required for the operation of the heat pump, the energy released at the time of cooling can be recovered and used for heat retention. Energy can be reduced.

  In the detoxification treatment method and the detoxification treatment system of the present invention, when the thermal balance between cooling water cooling and heating water heating is lost, an auxiliary device or the like can be used depending on the situation. For example, when the outside air temperature is high, such as during the daytime in summer, and there is little heat release from the container or piping, the heat obtained by cooling the mixed liquid is moved for heating by a heat pump, and the mixed liquid in the container Since the liquid temperature may become too high, in such a case, the heat pump is operated mainly to control the heat insulation state of the mixed liquid in the container, and cooling water that is insufficient for cooling is supplied using a separate refrigerator. can do. Conversely, when the outside air temperature is low as in winter and there is a lot of heat released from the container, piping, etc., if you try to obtain the heat necessary for heating the mixture with a heat pump, the mixture may be cooled too much, In this case, the heat pump can be operated mainly for the control of the cooling state of the mixed solution, and the heating of the mixed solution in the container can be combined with the heating by the ribbon heater or the like in the heat insulating device of the container.

  The catalyst filling device 4 used in the present invention is filled with a catalyst capable of decomposing PCB (details will be described later). Although this catalyst filling device 4 is not shown, it may be a replaceable catalyst cartridge type. This is because even if the decomposition rate is lowered during the treatment, it can be replaced easily and quickly, and the post-treatment of the catalyst after the treatment is easy.

  The catalyst filling device 4 is installed in the upper part inside the catalyst tank 3. FIG. 1 shows an example in which the catalyst filling device 4 is attached to the upper lid 6 of the catalyst tank 3. As a result, the space for the microwave processing apparatus can be saved, and the mixed liquid flowing through the catalyst filling apparatus 4 can be returned to the liquid reservoir 5 in the catalyst tank by its own weight. It is only necessary to provide means for supplying the mixed liquid to the apparatus 4 (pump), and no means for discharging the mixed liquid from the catalyst filling apparatus is required, so that the apparatus can be simplified. Moreover, by installing in the upper part in the catalyst tank 3, a liquid flow cross-sectional area can be designed largely according to the internal diameter of the catalyst tank 3, and a liquid flow rate becomes quick when space velocity (SV) is made constant. Therefore, the processing time can be shortened.

  On the other hand, when the catalyst filling device 4 is installed in the lower part of the inside of the catalyst tank 3, since the liquid mixture flowing through the catalyst filling device 4 cannot be stored, the liquid mixture and the container that are returned from the catalyst tank 3 to the container 1. It becomes difficult to balance the flow rate with the liquid mixture supplied from 1 to the catalyst tank 3, and when the balance is lost, the liquid mixture overflows from the catalyst filling device 4 or when the liquid runs out, the spark or the catalyst is abnormal. There is a risk of heating.

  The magnitude | size of the catalyst filling apparatus 4 is not specifically limited, Those shapes may be arbitrary shapes, such as a cylindrical shape and a rectangular tube shape. However, the catalyst filling device needs to have an inlet and an outlet for the mixed liquid.

  Here, as the catalyst filled in the catalyst filling device, an inorganic catalyst that has a long catalyst life and is stable even in the presence of an alkali compound is preferable. The inorganic catalyst is preferably a composite metal oxide, a carbon crystal compound, a metal-supported carbon compound, a metal-supported oxide, a metal-supported composite metal oxide, a metal oxide, or the like from the viewpoint of increasing the dehalogenation efficiency. Among these, a metal-supported carbon compound is preferable from the viewpoints of high stability in an alkaline atmosphere and good decomposition efficiency. These catalysts can be used after being used.

  As said metal carrying | support carbon compound, what carried 0.1-20 mass% of metals, such as iron, silver, platinum, ruthenium, palladium, rhodium with respect to the catalyst whole quantity, is preferable, and a viewpoint which improves dehalogenation efficiency. Therefore, the metal is preferably palladium, ruthenium, or platinum. Specific examples include Pd / C (palladium-supported carbon compound), Ru / C (ruthenium-supported carbon compound), Pt / C (platinum-supported carbon compound), and the like.

  The shape of the catalyst is not particularly limited, but when it is granular, it is necessary to fix the upper and lower sides of the apparatus (column) with a mesh or the like, and the catalyst particle diameter is preferably 75 μm to 10 mm. When it exceeds 10 mm, the specific surface area is insufficient, and when it is less than 75 μm, the mesh is clogged and the differential pressure becomes high. The catalyst particles should have the same particle size as possible.

  In the catalyst layer filled with the catalyst, as shown in FIG. 1, a rod-like structure 8 formed of a heat-resistant material that transmits microwaves partially protrudes from the catalyst layer. It is preferable to disperse and arrange. The existence of this structure is not essential, but by installing the structure, the microwave is transmitted to the depth of the catalyst layer. The shape of the structure is not particularly limited, and may be a rod shape, a tubular shape, a fiber shape, or a combination thereof. The inside of the structure may be hollow. The size, arrangement form, and number of arrangements are arbitrary, but in order to allow microwaves to reach the catalyst evenly, multiple structures are arranged as evenly as possible, and the microwave arrival circle approaches close packing It is preferable to arrange in such a manner.

  The material of the structure is not particularly limited, and may be ceramic; Teflon (registered trademark), polyphenylene sulfide (PPS), polyphenylene sulfone (PPSU), polyarylate (if it is a material that transmits microwaves) PAR), polysulfone (PSF), polyethersulfone (PES), polyetherimide (PEI), polyamideimide (PAI), polyetheretherketone (PEEK), liquid crystal polyester (LCP), liquid crystal polymer (LCP), polyacetal (POM), polyamide (PA), polybutylene terephthalate (PBT), polycarbonate (PC), modified polyphenylene ether, or other heat-resistant resin; glass or other material without a dipole or a material with a small dipole moment; Can That.

  In order to prevent overheating due to microwave irradiation and to equalize the microwave irradiation amount as much as possible, the microwave device 12 is a temperature controller 11 (PID control) for temperature measurement and temperature control of the mixed liquid in the catalyst filling device. With features). The microwave device outputs based on the temperature of the mixed solution in the catalyst filling device 4 detected by the temperature sensor 9 installed in the upper liquid of the catalyst layer and the set temperature of the temperature controller 11 (same as the reaction temperature). Therefore, the liquid temperature of the mixed liquid can be maintained at a substantially constant temperature while continuously irradiating microwaves.

  The installation location of the microwave device 12 is arbitrary, but if it is installed above the catalyst filling device 4, space saving can be achieved. When the mixed solution flowing through the catalyst filling device comes into contact with the catalyst heated by the microwave irradiated from the microwave oscillator, the PCB in the mixed solution is rapidly dehalogenated and decomposed.

  The frequency of the microwave applied to the catalyst filling device is preferably 1 to 300 GHz, and heating of the catalyst is insufficient in a frequency range of less than 1 GHz or more than 300 GHz. As the microwave oscillator, a microwave oscillator such as a magnetron, a microwave oscillator using a solid element, or the like can be used as appropriate.

  Irradiation of microwaves to the catalyst filling device can be performed continuously or intermittently. From the viewpoint of rapid processing, microwave irradiation is desired to be as continuous as possible or as long as possible. However, it is also possible to carry out only during the day taking into consideration the safety and cost of driving, securing personnel, etc. For example, intermittent irradiation such as irradiating microwaves during the day and stopping microwave irradiation at night You can also

  The circulation of the mixed liquid is continuously performed until the PCB in the mixed liquid becomes a predetermined concentration or less, but the PCB concentration in the liquid is measured by sampling and analyzing the circulating mixed liquid at an appropriate time. Although the sampling location is arbitrary, since the PCB eluted from the internal member is promoted to decompose by flowing through the catalyst filling device, it is most likely to be sampled from the mixed liquid take-out channel (pipe 17 or 18). PCB concentration is high.

  Although the sampling timing is also arbitrary, the elution of the remaining PCB and the decomposition of the PCB by microwave irradiation occur simultaneously, so that the PCB concentration in the liquid gradually decreases while moving up and down (see FIG. 3). Therefore, in order to accurately grasp the PCB concentration in the liquid, the microwave irradiation is stopped and only the mixed liquid is circulated (PCB is also eluted during this period), and immediately before the microwave irradiation is resumed, It is better to measure the PCB concentration.

  In terms of system management, the detoxification process is carried out until the PCB concentration of the liquid sampled and analyzed from the above time and location is below a predetermined reference value. According to the present embodiment, the time required for PCB detoxification processing can be reduced to about ½ compared to the case where cooling and heat insulation are not performed.

(Embodiment 2)
After the detoxification process of the device using PCB according to the first embodiment, the device is disassembled and separated into an iron core, a copper coil, an insulator, insulating paper, and a wooden frame. The measurement of the amount of PCB attached to each member is in accordance with the third of the 1992 Ministry of Health and Welfare Notification No. 192, revised August 1998 No. 222; Paper and wood comply with the Ministry of the Environment Notification No. 31 of 2004.

  As a result of analysis, when the disassembled member does not satisfy the predetermined graduation standard value, the member (iron core, copper coil, insulator, insulating paper) is returned to the container again, and the method described in the first embodiment is used. The detoxification process is performed, and the amount of PCB remaining on the internal member is made to be below the graduation reference value.

  For example, an iron core that does not satisfy the graduation standard value is placed in the pole transformer container 1 from which the iron core has been removed, and a solution composed of a hydrogen donor and an alkali compound is filled therein. Thereafter, the detoxification process is performed by the same method as described in the first embodiment. In addition, when carrying out the detoxification treatment of the members, it is desirable to use an electrical equipment container such as a pole transformer as the container in terms of the simplicity of the detoxification treatment system, but a separately prepared stainless steel container or the like is used. May be.

  According to this embodiment, the PCB detoxification process is usually completed in about 4 days, and the internal member can be made to be below the graduation reference value.

  As described above, according to the detoxification processing method and processing system of the present invention, the PCB adhering to the inner surface of the container and the PCB remaining on the internal member can be decomposed in a short period of time. When PCB remains in the disassembled member, the detoxification process can be carried out in parallel with the container process, so that the graduation reference value or less can be achieved. Therefore, it is possible to provide a method and system that can be detoxified without moving even in the case of large equipment, and that is simple, energy-saving, and economical.

  The present invention provides a method capable of detoxifying treatment easily and under energy saving conditions under normal pressure without moving the container after the PCB is extracted. If installed at a site such as a container, the container and the internal member can be rendered harmless at the site. Therefore, according to the present invention, since a large number of containers containing PCBs can be rendered harmless on a practical scale, the practical value of the present invention is extremely great.

DESCRIPTION OF SYMBOLS 1 Container 2 Mixed liquid 3 Catalyst tank 4 Catalyst filling apparatus 5 Liquid reservoir 6 Upper lid 7 Side pipe 8 Structure 9 Temperature sensor 10 Nitrogen introduction pipe 11 Temperature controller 12 Microwave apparatus 13 Cooler 14 Heater 15 Heat retention apparatus 16 Heat pump 17, 18, 19, 20 Piping 21 Internal member (coil)

Claims (14)

In a detoxification treatment method for decomposing PCB remaining in a container and an internal member constituting the device after the PCB is extracted with respect to the device using the PCB,
The container is filled with a solution composed of a hydrogen donor and an alkali compound and heated to elute PCB to form a mixed solution, and then a part of the mixed solution is taken out to prepare a catalyst filling device in the catalyst tank. The detoxification treatment method of decomposing the remaining PCB by irradiating the mixed solution circulating through the catalyst filling device with microwaves while returning to the container after circulating the
Heat retaining means for retaining the container;
A cooling means for cooling the mixed liquid to be circulated through the catalyst filling device, and
A heating means for heating the mixed liquid that returns the catalyst filling device to the container after distribution is provided,
A detoxifying treatment method for equipment using PCB, wherein the heat taken out by the cooling means is moved to the heating means by a heat pump.   The method for detoxifying PCB-using equipment according to claim 1, wherein the equipment is one of a pole transformer, a large transformer, or an oil tank of an oil insulated cable.   The method of detoxifying a device using PCB according to claim 1 or 2, wherein the output of the microwave is controlled by PID control of a temperature controller.   The method for detoxifying a device using PCB according to any one of claims 1 to 3, wherein the hydrogen donor is isopropyl alcohol.   The method for detoxifying PCB-using equipment according to any one of claims 1 to 4, wherein the alkali compound is at least one compound selected from caustic soda and caustic potash.   The method for detoxifying PCB-using equipment according to any one of claims 1 to 5, wherein the catalyst used in the catalyst filling device is a metal-supported carbon compound. A member in which PCB remains is placed in a container, and further, a solution composed of a hydrogen donor and an alkali compound is filled and heated to elute the PCB to obtain a mixed solution, and then a part of the mixed solution is taken out. The PCB remaining in the member is circulated through the catalyst filling device in the catalyst tank and then returned to the container to circulate the mixed solution and irradiate the mixed solution flowing through the catalyst filling device with microwaves. A detoxification treatment method for decomposing
Heat retaining means for retaining the container;
A cooling means for cooling the mixed liquid to be circulated through the catalyst filling device, and
A heating means for heating the mixed liquid returning to the container after distribution through the catalyst filling device is provided,
A method for detoxifying a PCB residual member, wherein the heat taken out by the cooling means is moved to the heating means by a heat pump.   The detoxification processing method according to claim 7, wherein the member is an iron core, a copper coil, an insulator, or insulating paper. For a device using PCB, after extracting the PCB, the container constituting the device was filled with a solution composed of a hydrogen donor and an alkali compound and heated to elute the PCB to obtain a mixed solution. A part of the mixed solution is taken out, circulated through the catalyst filling device in the catalyst tank, returned to the container, and the mixed solution is circulated to decompose the PCB remaining in the container and the internal member constituting the device. A detoxification processing system for
A heat retaining device for retaining the container;
A catalyst filling device;
A catalyst tank containing the catalyst filling device;
A microwave device for irradiating the catalyst filling device with microwaves;
A cooler provided in a flow path for taking out the liquid mixture in the vessel and introducing it into the catalyst tank;
A heater provided in a flow path for returning the mixed liquid flowing through the catalyst tank to the container;
A heat pump that moves the heat extracted by the cooling water circulating through the cooler to the hot water circulating through the heater;
A detoxification processing system for PCB-use equipment, comprising:   The PCB-using equipment detoxification processing system according to claim 9, wherein the equipment is one of a pole transformer, a large transformer, or an oil tank of an oil insulated cable.   The detoxification processing system for PCB-use equipment according to claim 9 or 10, wherein the microwave device includes a temperature controller that measures the temperature of the mixed liquid and performs PID control.   The harmless treatment system for PCB-using equipment according to any one of claims 9 to 11, wherein the hydrogen donor is isopropyl alcohol.   The detoxification processing system for PCB-using equipment according to any one of claims 9 to 12, wherein the alkaline compound is at least one compound selected from caustic soda and caustic potash.   The detoxification processing system for PCB-using equipment according to any one of claims 9 to 13, wherein the catalyst used in the catalyst filling device is a metal-supported carbon compound.

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