JP5287505B2 - Detoxification treatment method and detoxification treatment apparatus for organohalogen compound residual equipment - Google Patents

Description

  The present invention relates to a detoxification treatment method and a detoxification treatment apparatus for an organic halogen compound residual device, and in particular, an electric device (transformer, oil insulated cable) filled or stored with an organic halogen compound or an oil containing an organic halogen compound. Detoxification treatment method and detoxification, which removes organic halogen compounds or organic halogen compound-containing oils from the oil tank, etc., and then detoxifies the organic halogen compounds remaining in the equipment without disassembling these equipment. The present invention relates to a processing apparatus.

  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, oil tanks for oil-insulated cables, capacitors, etc., it is difficult to completely extract insulating oil containing organic halogen compounds, and insulating oil will remain in the equipment after the extraction process. An organohalogen compound remains. However, in the case of large equipment, it is difficult to move to the facility for carrying out the detoxification treatment, and in the case of equipment having a complicated internal structure, an organic halogen compound is used as a member such as insulating paper or wood chips. If the organic halogen compound in these members is extracted and removed after disassembling the equipment, it is difficult to sufficiently ensure safety during work and prevention of outflow to the environment. Therefore, there has been a demand for a technique that can be processed on-site without moving or dismantling the equipment, is excellent in work safety, economically and easily rendered harmless.

  In Patent Document 1, after extracting the insulating oil containing PCB filled in the equipment, a step of roughly cleaning with regenerated insulating oil, a step of cleaning with a finishing cleaning solution, and a dechlorination of the cleaning solution with metallic sodium There has been proposed a detoxification method having a process of performing the above. However, this method has a problem that a process for treating a large amount of waste liquid of insulating oil extracted from equipment, regenerated insulating oil used for rough cleaning, and finishing cleaning liquid is required.

  In Patent Document 2, a stationary induction machine containing an organic halogen compound is installed in a pressure vessel together with water and an oxidizing agent, 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 method has been proposed. However, since this method is reacted at a high temperature (430 ° C.) and a high pressure (25 MPa), there is a problem that the apparatus becomes large, the installation place is limited, and the economy is inferior.

  In Patent Document 3, the device after extracting the insulating oil containing PCB is filled with an isopropyl alcohol solution in which KOH is dissolved, and the mixed solution in which PCB is eluted is irradiated with microwaves. While remaining in the catalyst filling device with a structure that heats the catalyst, and circulating between the device and the catalyst filling device, the PCB remaining in the device and its internal accessory material is dissolved and decomposed until it meets the graduation criteria. The detoxification treatment method is described. That is, the PCB in the insulating oil that could not be removed from the device without dismantling the container and the PCB remaining in the member inside the device are collectively rendered harmless without disassembling the container.

  However, in the method described in Patent Document 3, microwaves are irradiated to increase the activity of the catalyst. However, if the amount of microwave irradiation is increased, the temperature of the liquid becomes too high, and dioxins and the like are by-produced. Therefore, there is a problem that the microwave irradiation amount has to be limited.

  Therefore, it was also considered to install a cooling device in the middle of the pipe connecting the container and the catalyst filling device. However, in summertime when the temperature is high, the cooling effect may be insufficient, and the temperature of the liquid that returns from the catalyst filling device to the container does not fall down. Therefore, in order to suppress the by-product of dioxins, the amount of microwave irradiation was inevitably reduced.

  In addition to the above, a method for treating an organic halogen compound using microwave energy is known (see, for example, Patent Documents 4 to 6). In Patent Document 4, a gaseous chlorofluorocarbon is irradiated with microwaves to generate thermal plasma, and the chlorofluorocarbon reacts with water vapor in the thermal plasma to be decomposed. In Patent Document 5, moisture and an alkaline substance are added to the inside of a casing to which dioxins are attached, and the treatment is performed by irradiating microwaves. However, these methods treat organic halogen compounds in a gas phase and are not liquid treatment methods, so there is no problem with liquid temperature control during microwave irradiation, but a pressure device is required. There is a problem in terms of device cost.

  Patent Document 6 discloses an aromatic chlorine compound by irradiating a reaction system including a platinum group catalyst supported on a carbon-based support and an aromatic chlorine compound with microwaves in the presence of a reducing substance such as hydrogen. A method of dechlorinating is described. However, in this method, it is difficult to decompose the hardly-decomposable PCB, and it is necessary to supply hydrogen gas from the outside to the reaction system, which is not preferable as a practical method.

JP 2004-008842 A JP 2000-116814 A JP 2009-011848 A JP 2002-177735 A JP 2005-169291 A JP 2001-019466 A

  The present invention has been made in view of the above-mentioned problems, and specially detoxifies organic halogen compounds remaining in containers and internal members of devices such as transformers (on pillars, large-sized) that contain organic halogen compounds. A detoxification treatment method for organohalogen compound residual equipment that can be detoxified before dismantling the equipment easily and in a short period of time without using a treatment apparatus and without generating by-product harmful dioxins, and An object is to provide a detoxification processing apparatus.

  As a result of intensive studies to solve the above problems, the inventors of the present invention filled a solution containing a hydrogen donor and an alkali compound into a container in which an organic halogen compound remains, and eluted the organic halogen compound to obtain a mixed solution. Then, after circulating the catalyst filling device arranged in the upper part of the catalyst tank, the mixed solution is returned to the container to circulate the mixed solution between the catalyst filling device and the container. By alternately repeating the process of decomposing the organic halogen compound by irradiating the microwave when circulating through the catalyst filling device and the process of eluting the organic halogen compound remaining in the container by stopping the microwave irradiation, In the detoxification treatment method for decomposing the remaining organic halogen compounds, the mixed solution that has been circulated through the catalyst filling device is stored in a liquid reservoir at the bottom of the catalyst tank and cooled, so that the organic ha It found that the plasminogen compound may detoxifying, and have completed the present invention.

  That is, the present invention is as follows.

(1) For a container containing an organic halogen compound or an oil containing an organic halogen compound, after extracting the organic halogen compound or the oil containing the organic halogen compound, the container and a member installed in the container (hereinafter referred to as an internal member) In the detoxification treatment that decomposes the organic halogen compound remaining in the internal member,
The container is filled with a solution comprising a hydrogen donor and an alkali compound to elute the organic halogen compound to obtain a mixed solution, and then a part of the mixed solution is taken out and placed in the upper part of the catalyst tank. After the filling device is circulated and stored in the liquid reservoir at the bottom of the catalyst tank, the mixture is returned to the container to circulate the mixed solution, and the microwave irradiation to the mixed solution flowing through the catalyst filling device is stopped and stopped. A detoxification treatment method that decomposes an organic halogen compound repeatedly at regular intervals,
A detoxification treatment method for an organohalogen compound residual device, wherein a cooling coil is installed in a liquid reservoir in a lower part of a catalyst tank, and a mixed liquid stored in the liquid reservoir is cooled by the cooling coil during microwave irradiation.
(2) During microwave irradiation, when the temperature (reaction temperature) of the mixed liquid flowing through the catalyst filling device becomes equal to or higher than a preset control temperature, the microwave irradiation intensity is limited and the catalyst tank The mixed liquid cooled in the lower liquid pool is circulated directly to the catalyst filling device without returning to the container,
When the temperature of the liquid mixture (reaction temperature) flowing through the catalyst filling device drops below a preset temperature, the microwave irradiation intensity is restored and the mixture is cooled in the liquid reservoir at the bottom of the catalyst tank. The detoxification method according to (1), wherein the circulation of returning the liquid to the container is resumed.
(3) The detoxification method according to (2), wherein the management temperature is a predetermined reaction temperature plus 10 ° C., and the set temperature is a predetermined reaction temperature minus 10 ° C.
(4) The harmless treatment method according to any one of (1) to (3), wherein the irradiation intensity of the microwave is controlled by PID control corresponding to the management temperature and the set temperature.

(5) A member in which the organic halogen compound remains is placed in a container, and further filled with a solution comprising a hydrogen donor and an alkali compound to elute the organic halogen compound to obtain a mixed solution, and then a part of the mixed solution The catalyst filling device placed in the upper part of the catalyst tank is circulated and stored in the liquid reservoir at the lower part of the catalyst tank, and then returned to the container to circulate the mixed liquid. It is a detoxification treatment method for decomposing an organic halogen compound remaining in the member by repeatedly irradiating and stopping microwave irradiation to the mixed liquid at regular intervals.
A detoxifying treatment method for an organic halogen compound residual member, wherein a cooling coil is installed in a liquid reservoir at a lower portion of a catalyst tank, and a mixed liquid stored in the liquid reservoir is cooled by the cooling coil during microwave irradiation.
(6) The detoxification processing method according to (5), wherein the member is an iron core, a copper coil, an insulator, or insulating paper.

(7) For a container containing an organic halogen compound or an oil containing an organic halogen compound, after extracting the organic halogen compound or the oil containing the organic halogen compound, the organic halogen compound is filled with a solution comprising a hydrogen donor and an alkali compound. A detoxification treatment apparatus for decomposing an organic halogen compound remaining in a member (hereinafter referred to as an internal member ) installed in the container after eluting the compound into a mixed solution,
(A) a catalyst filling device;
(B) a catalyst tank in which the catalyst filling device is accommodated in the upper part, and the lower part is a liquid reservoir;
(C) A container circulation system for taking out the mixed liquid in the container, supplying it to the catalyst filling device, and then returning it to the container;
(D) a microwave device for irradiating the catalyst filling device with microwaves;
(E) a cooling coil for cooling the liquid mixture stored in the liquid reservoir at the bottom of the catalyst tank during microwave irradiation;
A detoxification processing apparatus comprising at least
(8) Furthermore,
(F) a temperature sensor for measuring the temperature of the mixed liquid flowing through the catalyst filling device;
(G) When the temperature of the liquid mixture flowing through the catalyst filling device becomes equal to or higher than a preset control temperature during the microwave irradiation, the temperature of the liquid mixture is reduced until it becomes equal to or lower than the preset temperature. A microwave control device for limiting the irradiation of waves;
(H) a catalyst tank circulation system for removing the mixed liquid from a liquid reservoir at the bottom of the catalyst tank, supplying the mixed liquid to the catalyst filling device, and then returning the mixture to the catalyst tank;
(I) a system controller that circulates the mixed liquid in the catalyst circulation system while limiting the irradiation intensity of the microwave;
The detoxification processing apparatus according to (7), comprising:
(9) The microwave control device controls the irradiation intensity of the microwave by PID control corresponding to the management temperature and the set temperature of the liquid mixture flowing through the catalyst filling device. Detoxification processing apparatus as described.

  In the detoxification treatment method for an organohalogen compound residual device of the present invention, microwave irradiation is performed by repeating a cycle in which irradiation is stopped for a certain period of time after irradiation for a certain period of time. During microwave irradiation, since the liquid to be circulated is cooled in a liquid reservoir at the bottom of the catalyst tank, it becomes possible to increase the amount of microwave irradiation compared to the conventional method, and the organic halogen compound remaining in the container and the internal member can be reduced. It can be detoxified in a very short time. In addition, since cooling is performed using a liquid reservoir provided in the catalyst tank, the space of the apparatus can be saved, and there are problems that may occur when the line (pipe) is cooled from the outside, such as by-products. There is no risk of clogging of lines (piping) due to the precipitation of inorganic salts.

  In the present invention, when the microwave is stopped, the mixed liquid circulates between the catalyst tank and the container, so that elution of the organic halogen compound remaining in the container and the internal member mainly occurs. By limiting the cooling of the liquid during the microwave irradiation, the mixed liquid is not unnecessarily cooled, so that the elution of the organic halogen compound is not hindered.

  On the other hand, when the mixed liquid flowing through the catalyst filling device becomes high temperature, by restricting the microwave output, it is possible to prevent dioxins by-products and prevent abnormal heating of the mixed liquid. , Can increase safety. Further, while the microwave irradiation intensity is limited, cooling of the catalyst tank can be promoted by supplying the mixed liquid in the sufficiently cooled liquid reservoir directly to the catalyst tank.

  Furthermore, the microwave output can be effectively increased and leveled by controlling the microwave output by the PID control of the microwave control device.

  When there is a member that does not satisfy the predetermined processing standard value, the member is placed in a container and subjected to a detoxification process similar to the method of (1) or (2) above. Since it can be detoxified and does not require a new processing apparatus, it is economical.

  The organic halogen compound detoxification treatment apparatus of the present invention substantially removes the organic halogen compound remaining in the container and the internal member after extracting the organic halogen compound or the oil containing the organic halogen compound from the container containing the organic halogen compound. This is a device that can be detoxified without dismantling the equipment and does not require special devices for liquid cooling and temperature control.

It is a figure explaining the outline of the usage example of the detoxification processing apparatus which concerns on this invention. It is a front perspective view which shows one Embodiment of the detoxification processing method and detoxification processing apparatus which concern on Claim 1 and Claim 7 of this invention, the liquid mixture taken out from the container distribute | circulates a catalyst filling apparatus, and is a container again The circulation path to return to is also shown. It is a front perspective view which shows one Embodiment of the detoxification processing method and detoxification processing apparatus which concern on Claim 2 and Claim 8 of this invention, and the liquid mixture taken out from the liquid reservoir of a catalyst tank lower part is a catalyst filling apparatus. A circulation path that circulates and returns to the catalyst tank is also shown.

  Hereinafter, a detoxification treatment method and a detoxification treatment apparatus for an organohalogen compound residual device according to the present invention will be described in detail with reference to the drawings.

The detoxification treatment method of the present invention is carried out by installing the detoxification treatment apparatus of the present invention outside a container such as a pole transformer in which the organic halogen compound remains, and using the apparatus.
The embodiment is not particularly limited. For example, as shown in FIG. 1, a pole transformer (container) is placed on the oil pan 27, and the detoxification processing apparatus of the present invention is placed on the oil pan 28 above the oil pan 27. Organohalogen compounds remaining in the container and members installed in the container (hereinafter referred to as internal members ) by connecting the upper transformer (container) and the detoxification treatment device with a line and then performing a predetermined treatment . Can be decomposed and detoxified.

  In the detoxification treatment method of the present invention, a known method can be used for the decomposition of the organic halogen compound itself. That is, an organic halogen compound or oil containing an organic halogen compound contained in a container such as a pole transformer is extracted by a normal method using a pump or the like, and then filled with a solution composed of a hydrogen donor and an alkali compound. Then, the organic halogen compound remaining in the inner wall of the container or the member installed in the container is eluted to obtain a mixed solution. Next, the mixed liquid is passed through a catalyst filling device provided in the catalyst tank, and irradiated with microwaves while being in contact with the catalyst, thereby decomposing and detoxifying the organic halogen compound. In the detoxification treatment method of the present invention, during the microwave irradiation, the mixed liquid circulated through the catalyst filling device is cooled in the liquid reservoir at the bottom of the catalyst tank and then circulated to circulate the temperature of the mixed liquid. It is characterized in that the organic halogen compounds can be decomposed safely and efficiently.

  Examples of the container to which the method of the present invention can be applied include containers such as transformers (pillars, large sized) and oil tanks for oil-insulated cables. In particular, there are various accessory members with complicated structures inside the equipment, and containers for pole transformers and large transformers where organic halogen compounds may be infiltrated into the materials such as paper and wood. It is preferable to apply to processing. Here, the large transformer refers to a transformer having an insulating oil capacity of 100L to 300,000L. Examples of the internal member include an iron core, a copper coil, an insulator, insulating paper, and a wooden frame.

  Examples of the organic halogen compound to be detoxified according to the present invention include polychlorinated biphenyls (PCBs) and dioxins, and the type is not particularly limited, but is preferably PCB. It is kind. 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.

  2 and 3 are schematic views showing an embodiment of the detoxification treatment method and the detoxification treatment apparatus of the present invention, showing an example of the detoxification treatment of the organic halogen compound remaining in the container and the internal member. It is.

  The detoxification treatment apparatus of the present invention is a detoxification treatment apparatus capable of decomposing an organic halogen compound remaining in a container and an internal member without disassembling the container. In carrying out the detoxification treatment, it is necessary to fill the container with a solution comprising a hydrogen donor and an alkali compound.

  When the solution is filled, the amount is adjusted to an amount sufficient to immerse the inner member of the container and not overflow from the container. 2 and 3, reference numeral 29 indicates the liquid level of the solution 2 filled in the pole transformer (container) 1, and the solution is a pole transformer installed in the pole transformer 1. The amount of the internal winding (coil) 3 is filled.

  The container 1 may include a solution supply line. For example, an apparatus (pre-tank) (not shown) that stores a solution in which an alkali compound is dissolved in a hydrogen donor by mixing a hydrogen donor and an alkali compound in advance is installed, and a supply line that supplies the solution from the apparatus to the container 1 ( (Not shown) may be provided.

  The detoxification treatment apparatus of the present invention includes (a) a catalyst filling device 4, (b) a catalyst filling device 4 accommodated in the upper portion thereof, and a lower portion thereof serving as a liquid reservoir, (c) in the vessel 1 After the liquid mixture was taken out and supplied to the catalyst filling device 4, the container circulation system (supply line 15, lines 16, 17 and pump 9) for returning to the container again, (d) microwave irradiation to the catalyst filling device 4 A microwave device 12 for performing the above and (e) a cooling coil 18 for cooling the mixed liquid stored in the liquid reservoir in the lower part of the catalyst tank during the microwave irradiation are configured as essential components. Hereinafter, the configuration of the apparatus will be described in order.

(A) Catalyst filling device The catalyst filling device 4 is filled with a catalyst capable of decomposing an organic halogen compound (particularly PCB). The catalyst filling device 4 includes a replaceable catalyst cartridge 5 from the viewpoint that it can be easily and quickly replaced when the decomposition speed is lowered during the process and the post-treatment of the catalyst after use is easy. It is preferable.

  The catalyst filling device 4 is installed in the upper part of the catalyst tank 7. Then, by installing the catalyst filling device 4 above the container 1, the entire processing device can be saved in space and compact. Further, by installing the catalyst filling device above the container, the liquid after circulation of the device can be returned to the container by its own weight, so it is only necessary to provide a liquid supply means from the container to the catalyst filling device, There is an advantage that a pump for discharging is not required. Furthermore, as a result of space saving, the liquid flow cross-sectional area of the catalyst layer in the catalyst filling device can be designed to be large according to the internal volume of the container 1 to be processed, and the space velocity (SV) is constant. Even in this case, the liquid flow rate can be increased, leading to a reduction in the time required for decomposition.

  The shape and size of the catalyst filling device are not particularly limited, and may be in various forms. For example, a cylindrical shape, a rectangular tube shape, or the like. However, the catalyst filling device needs to have an inlet and an outlet for the mixed liquid.

  The catalyst filling device 4 shown in FIGS. 2 and 3 is formed with a catalyst layer 6 filled with a catalyst, which will be described later, capable of decomposing organic halogen compounds. The mixed liquid 2 is introduced into the upper portion of the catalyst filling device by the line 16 through the supply line 15 and the pump 9 as shown by the arrows in the figure, through the inlet provided in the upper portion of the catalyst filling device 4. The introduced mixed solution continuously flows through the catalyst layer 6, and the mixed solution 2 after flowing through the catalyst layer flows down from the bottom of the catalyst filling device 4. The liquid level of the mixed liquid in the catalyst filling device is always kept higher than the catalyst layer. The mixed liquid flowing down from the bottom of the catalyst filling device flows out into the catalyst tank 7 containing the catalyst filling device, and is then stored in the lower part of the catalyst tank 7, cooled by the cooling coil 18, and returned to the container 1. It is circulated in. The arrows in FIG. 2 and FIG. 3 indicate the general flow direction of the mixed liquid flowing through the catalyst filling device.

  2 and 3, in the catalyst layer 6, rod-like structures 8 formed of a heat-resistant material that transmits microwaves are dispersed and arranged so that a part thereof protrudes from the catalyst layer. ing. 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, and number of arrangements are arbitrary, but in order to ensure that microwaves reach the catalyst evenly, multiple structures are arranged as evenly as possible, and the microwave arrival circle of each structure It is preferable to arrange so as to approach close packing.

  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.

(B) Catalyst tank The catalyst tank 7 is configured so as to accommodate the catalyst filling device 4 and store the mixed liquid flowing through the catalyst filling device 4 in the lower part of the catalyst tank and return it to the container. A liquid discharge port 30 for returning the mixed liquid to the container is provided on the bottom surface of the catalyst tank.

(C) Circulation system The circulation system includes a pipe and a pump for circulating the mixed liquid to the container 1, the catalyst filling device 4, and the catalyst tank 7. There are two types of circulation systems: a container circulation system and a catalyst tank circulation system.

In the container circulation system, as shown in FIG. 2, the mixed liquid is first sucked from the container 1 to the catalyst tank 7 via the pump 9, and the sucked liquid flows down in the catalyst filling device 4, The liquid is stored and cooled in the liquid reservoir, and then returned to the container 1 through the discharge port 30. At this time, the extraction valve 22 and the pump outlet valve 23 are opened, the pump inlet valve 24 and the sampling valve 26 are closed, and the mixed liquid is circulated. The return valve 25 adjusts opening and closing so that the liquid is always stored in the liquid reservoir in the lower part of the catalyst tank.
Usually, a container circulation system is used. By circulating the mixed liquid in the container 1 to the catalyst filling device 4 and decomposing the organic halogen compound, the concentration of the organic halogen compound in the mixed liquid in the container 1 is reduced, and elution from the container 1 and the internal member is promoted. It is because it can be made.

  In the catalyst tank circulation system, as shown in FIG. 3, the mixed liquid stored and cooled in the liquid reservoir in the lower part of the catalyst tank is transferred between the catalyst filling device through the lines 21 and 16 connecting the catalyst tank 7 and the pump 9. Circulate. At this time, the pump inlet valve 24 and the outlet valve 23 are opened, the extraction valve 22, the return valve 25 and the sampling valve 26 are closed, and the mixed liquid is circulated. The discharge port 30 is kept closed.

  As will be described later, it is preferable to use the catalyst tank circulation system while the temperature of the mixed liquid in the catalyst filling device rises and the microwave irradiation intensity is limited. This is because the cooling of the catalyst tank can be promoted by supplying the mixed liquid in the sufficiently cooled liquid reservoir directly to the catalyst tank. This system switching is performed by a system control device (not shown). In the system control device, the system is switched by controlling the opening and closing of the extraction valve 22, the outlet valve 23, the pump inlet valve 24, the return valve 25 and the sampling valve 26.

  The pump 9 is used as means for transferring the liquid mixture in the container 1 to the catalyst filling device and means for circulating the liquid mixture in the catalyst tank. The mounting position of the pump 9 is not particularly limited, and may be provided at any location outside the container 1. In particular, when the pump 9 is provided adjacent to the catalyst tank 7, the lower part of the catalyst tank is provided. The operation of circulating the mixed liquid stored in the liquid reservoir to the catalyst filling device (see FIG. 3) becomes easy. The pump 9 is provided with lines 15, 16 and 21 for supplying and circulating the mixed liquid 1 through the pump 9. As a result, it is possible to continuously supply the mixed solution to the catalyst filling device and bring the organic halogen compound into contact with the catalyst.

(D) Microwave device When the temperature of the mixed liquid flowing through the catalyst filling device becomes equal to or higher than the control temperature during the microwave irradiation, the microwave device 12 has a temperature of the mixed liquid flowing through the catalyst filling device. It is preferable to provide a microwave control device that limits the intensity of microwave irradiation until the temperature falls below the set temperature. This is because abnormal heating of the mixed liquid can be prevented and safety can be improved. Here, the control temperature and set temperature of the temperature of the mixed solution may be set in consideration of the reaction temperature described later, but the control temperature is usually set to plus 10 to 20 ° C., preferably plus 10 ° C. of the reaction temperature. Is done. The set temperature is usually set to minus 5 to 10 ° C., preferably minus 10 ° C. of the reaction temperature.

  Further, in order to level the microwave irradiation amount, a temperature controller (with a PID control function) for temperature measurement and temperature control of the mixed liquid in the catalyst filling device may be provided. Based on the temperature detected by the temperature sensor 10, the management temperature of the temperature controller 11, and the set temperature, the irradiation intensity of the microwave device 12 is PID controlled, so that the liquid temperature of the mixed liquid is substantially constant while continuously irradiating the microwave. Can be held at temperature.

  In the detoxification processing apparatus of the present invention, the installation location of the microwave device 12 is not particularly limited, but space saving can be achieved if it is provided above the catalyst filling device 4. The mixed liquid flowing through the catalyst layer 6 comes into contact with the catalyst heated by the microwave irradiated from the microwave oscillator, so that the organic halogen compound contained in the mixed liquid is rapidly decomposed.

  The frequency of the microwave applied to the catalyst filling device is preferably 1 to 300 GHz, and in the frequency range of less than 1 GHz or more than 300 GHz, the catalyst and the hydrogen donor are not sufficiently heated. 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.

  As described above, it is preferable to intermittently irradiate the catalyst filling apparatus with microwaves at regular intervals. By stopping the microwave irradiation and checking the organic halogen compound concentration in the mixture, the amount of elution from the container 1 and internal members can be accurately grasped, and the remaining amount and the progress of the detoxification process can be accurately determined. This is because it can be managed. The microwave irradiation time and stop time can be set arbitrarily, and it is possible to perform microwave irradiation only in the daytime in consideration of driving safety, cost, securing personnel, etc. For example, microwave irradiation is performed in the daytime. It is also possible to carry out intermittent irradiation that stops microwave irradiation at night.

(E) Cooling coil The cooling coil 18 is provided at an appropriate location inside the catalyst tank 7 so as to cool the mixed liquid stored in the liquid reservoir below the catalyst tank 7. The illustrated cooling coil 18 uses a cooling water circulation device 13 such as a general heat exchanger to which a cooling medium is supplied from a cold heat source, and the cold water supplied from the device 13 to the cooling coil inlet via a line 19 is supplied. It is designed to return to the apparatus 13 via the line 20 from the cooling coil outlet after contact with the mixed liquid.

  Cooling by the cooling coil 18 is performed during microwave irradiation. Since the amount of microwave irradiation can be increased by lowering the temperature of the mixed liquid flowing through the catalyst filling device, decomposition of the organic halogen compound is promoted. In addition, by limiting the cooling of the liquid mixture to microwave irradiation, the liquid mixture is not unnecessarily cooled, and the detoxification treatment by the catalyst while the microwave is stopped and the elution from the container and the internal member are possible. This is because there is no risk of obstruction. Note that if the temperature of the liquid reservoir becomes too low, the liquid returned to the container will be too cold, and the organic halogen compound that has permeated the member will be difficult to elute into the liquid. The flow rate of the cooling water may be adjusted by the water flow rate adjuster 14.

  The installation location and the installation form of the cooling coil are not particularly limited. For example, as shown in the figure, the catalyst filling device 4 is mixed in the mixed liquid stored in the lower part of the catalyst tank 7 that houses the catalyst filling device. If it is arranged so as to go around the projection surface, the cooling efficiency is good. Since the microwave is blocked by the catalyst filling device and does not reach the liquid reservoir, the mixed liquid stored in the liquid reservoir is not likely to be heated by the microwave.

  As described above, the detoxification treatment apparatus of the present invention normally contacts the catalyst while circulating the mixed liquid between the container and the catalyst tank, while the microwave irradiation intensity is limited. It is preferable to contact the catalyst while circulating the mixed solution only in the catalyst tank. In either case, the mixture flowing through the catalyst filling device is irradiated with microwaves to accelerate the decomposition of the organohalogen compounds, and the liquid reservoir at the bottom of the catalyst tank is cooled to reduce the microwave irradiation time as much as possible. It is configured to be cooled with.

  As a means for cooling the mixed liquid heated by the microwave irradiation, it is conceivable to provide a cooling means in the middle of the line 17 returning from the catalyst tank 7 to the container 1. However, this means is not preferable from the viewpoint of space saving because it is necessary to newly install a liquid reservoir provided with a cooling coil, and the temperature of the mixed liquid flowing through the catalyst filling device is excessively raised and quickly cooled. It becomes impossible to cope with the need. Alternatively, when such means is employed, there is no problem in circulating both the catalyst tank and the container, but the liquid returned to the container is too cold, and the organic halogen compound that has permeated the member is difficult to elute into the liquid. Inconvenience such as becoming may occur.

  Further, as another cooling means, it is conceivable to provide a cooling means immediately before the entrance of the catalyst tank 7 (in the middle of the line 16). However, this means is not preferable from the viewpoint of space saving because it is necessary to newly install a liquid reservoir provided with a cooling coil. In addition, since the mixed liquid heated by flowing through the catalyst filling device returns directly to the container, there arises a safety problem that the temperature of the mixed liquid in the container rises. Therefore, when cooling in the middle of the line, a method of directly cooling the line from the outside (for example, introducing a mixed solution into the chiller tube) is suitable, but a sufficient length of line necessary for cooling is secured. In addition, there is a risk that clogging occurs due to deposition of by-products (KCl or the like) inside the cooled line.

  Thus, when the cooled mixed liquid comes into contact with the catalyst heated by the microwave, the organic halogen compound in the mixed liquid is rapidly decomposed. That is, since the mixed liquid that has circulated through the catalyst filling device is circulated after being cooled, the liquid temperature at the inlet of the catalyst filling device decreases, so that the microwave irradiation amount can be increased, and the dioxin can be increased. In decomposing an organic halogen compound while suppressing by-products such as the like, the decomposition efficiency of the organic halogen compound is remarkably improved as compared with the case where the mixed solution is circulated without cooling.

  The mixture solution may be circulated until the organic halogen compound in the mixture solution has a predetermined concentration or less. When appropriate, the mixture solution is sampled and analyzed from the sampling valve 26 provided in the detoxification treatment apparatus. Thus, the organic halogen compound concentration can be measured.

  Next, an embodiment of the detoxification treatment method for organic halogen compound residual equipment according to the present invention using the detoxification treatment apparatus will be described with reference to FIG.

  First, the container 1 shown in FIG. 2 in which the organic halogen compound remains is filled with a solution 2 composed of a hydrogen donor and an alkali compound described later, and then stirred as necessary. The filling amount is preferably set to such an amount that the inner member of the container is immersed. What is necessary is just to add the amount which an alkali compound mentions later with respect to a hydrogen donor. After the solution is filled, in order to elute the remaining organic halogen compound, the solution may be circulated, stirred, or left standing with the solution filled.

  Thereafter, the mixed solution 2 from which the organic halogen compound is eluted is continuously passed through the catalyst filling device 4 filled with the catalyst to dehalogenate the organic halogen compound. When the mixed solution flows through the catalyst filling device, Is irradiated with microwaves. The temperature of the mixed liquid when flowing through the catalyst filling device is detected by a temperature sensor 10 installed in the upper liquid of the catalyst layer. The reaction temperature (that is, the temperature of the mixed solution) is preferably as low as possible in order to suppress the formation of by-products such as dioxins, but is preferably room temperature or higher and 200 ° C. or lower in view of the decomposition rate. Is 100 ° C. or lower, and when the reaction temperature exceeds 200 ° C., the dehalogenation reaction proceeds sufficiently, but by-products are likely to be generated, and the economy is inferior. In particular, in the present invention for cooling the liquid mixture stored in the liquid reservoir, the temperature at which the cooling effect can be sufficiently exerted is in the range of 40 ° C to 80 ° C. The time for circulating the mixed solution through the catalyst filling device is not particularly limited, and the mixing is performed until the organic halogen compound in the mixed solution is equal to or lower than a predetermined processing reference value. The cooling in the liquid pool is preferably performed so that the temperature of the stored mixed liquid is at least 5 ° C., desirably 10 ° C. or more lower than the reaction temperature. Particularly preferably, the reaction is cooled to 10 to 20 ° C. lower than the reaction temperature. Too much cooling of the mixed solution is not only economical but also hinders elution of the organic halogen compound.

  By performing the above decomposition treatment, the organic halogen compound concentration in the mixed solution can be reduced to 0.5 ppm or less in a short period of time. After completion of the decomposition, the mixed liquid in the container is extracted from the container via an extraction pump or a drain valve.

  In the detoxification treatment method of the present invention, examples of the “hydrogen donor” include organic hydrogen donors such as heterocyclic compounds, amine compounds, alcohol compounds, ketone compounds, and alicyclic compounds. Can be mentioned. 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 can be used alone or in any combination of two or more.

  Here, the alcohol compound may be either an aliphatic alcohol or an aromatic alcohol, and a monohydric alcohol or polyhydric alcohol having a linear or branched chain can be used. The carbon number of the alcohol compound is preferably in the range of 1 to 12, more preferably in the range of 2 to 9, and still more preferably in the range of 3 to 6. Specific examples of the alcohol compound include, for example, methanol, ethanol, 1-propanol, 2-propanol, n-butanol, s-butanol, t-butanol, 1-pentanol, 2-pentanol, and 3-pentanol. 1-hexanol, 2-hexanol, 3-hexanol, 1-heptanol, 2-heptanol, 3-heptanol, 1-octanol, 2-octanol and other aliphatic alcohols, cyclopropyl alcohol, cyclobutyl alcohol, cyclopentyl alcohol, cyclohexyl Examples thereof include alicyclic alcohols such as alcohol, cycloheptyl alcohol and cyclooctyl alcohol, and polyhydric alcohols such as ethylene glycol, propylene glycol and decalin diol. Among these, 2-propanol and cyclohexanol are preferable from the viewpoint of decomposition efficiency, and 2-propanol (isopropyl alcohol) is particularly preferable.

  The alkali compound can be used without limitation as long as it can accelerate the dehalogenation reaction of the organic halogen compound, but from the viewpoint of increasing the dehalogenation efficiency, caustic soda, caustic potash, sodium alkoxide, potassium alkoxide. , Calcium hydroxide and the like are preferably used. Among these, caustic soda and caustic potash are particularly preferable from the viewpoint of cost and handling properties. An alkali compound can be used individually or in combination of 2 or more types.

  In the detoxification treatment method of the present invention, a solution obtained by previously mixing and stirring the hydrogen donor and the alkali compound to dissolve the alkali compound in the hydrogen donor may be used. In this case, the amount of the alkali compound used is preferably 0.1 to 10% (w / v), more preferably 0.2 to 5% (w / v) as a ratio to the hydrogen donor. is there. If the ratio is less than 0.1%, the decomposition reaction does not proceed, and if it exceeds 10%, the alkali compound is difficult to dissolve.

  The catalyst to be filled in the catalyst filling apparatus of the present invention is not particularly limited as long as it can promote the dehalogenation reaction of PCB, and its catalyst life is long and stable even in the presence of an alkali compound. Inorganic catalysts are preferred. As the inorganic catalyst, 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, and the like are preferable from the viewpoint of increasing the dehalogenation efficiency. A metal-supported carbon compound having high stability and high microwave absorption in an alkaline atmosphere is preferable. These catalysts can be used individually or in combination of 2 or more types. Further, a regenerated catalyst obtained by regenerating the used catalyst may be used.

  The metal loading of the metal-supporting carbon compound is preferably 0.1 to 20% by mass, more preferably 0.1 to 10% by mass, based on the total amount of the catalyst. Examples of the supported metal include iron, silver, platinum, ruthenium, palladium, and rhodium. From the viewpoint of increasing the dehalogenation efficiency, palladium, ruthenium, and platinum are preferable. Specific examples of the metal-supported carbon compound include Pd / C (palladium-supported carbon compound), Ru / C (ruthenium-supported carbon compound), and Pt / C (platinum-supported carbon compound).

  The shape of the catalyst is not particularly limited, but in the case of a granular form, it is necessary to fix the upper and lower sides of the catalyst layer with a mesh or the like, and the particle diameter in that case is preferably about 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. More preferably, it is 150 micrometers-5 mm. The catalyst particles are preferably as uniform as possible.

  According to the detoxification method of the present invention, the organic halogen compound adhering to the inner surface of the container and the organic halogen compound remaining on the inner member are also decomposed, so that each member can be reused by disassembling the container. You can also.

  On the other hand, when the member disassembled after the detoxification process does not satisfy the predetermined graduation reference value, the member may be returned to the container again and the detoxification process may be performed by the above method. At this time, an electrical equipment container such as a pole transformer may be used as the container, or a separately prepared cleaning container may be used.

  EXAMPLES Next, although an Example demonstrates this invention concretely, this invention is not limited only to a following example. In the following examples and the like, “mass%” is abbreviated as “%” unless otherwise specified. In the following experiments, the apparatus shown in FIG. 2 was used.

Example 1
10 types of pole transformer containers (A to J) from which insulating oil (PCB concentration is 0.9 to 28.9 mg / kg) was extracted, and each was a solution in which KOH was dissolved in isopropyl alcohol (KOH concentration 0.5 w). / V%).
A catalyst tank having a capacity of 20 L was installed on the upper part of the pole transformer, and an activated carbon catalyst supporting 5% palladium was filled in a catalyst filling device arranged on the upper part of the catalyst tank. A cooling coil having a structure in which a steel tube having an inner diameter of 6 mm is stacked in a circular shape having a diameter of 420 mm in three stages is disposed at the lower portion of the catalyst tank.

  While circulating the mixed liquid in the container through the catalyst layer of the catalyst filling device and circulating between the container and the catalyst filling device at a flow rate of 800 ml / min using a circulation pump, the microwave is intermittently interrupted as follows. The container and the internal member were detoxified by irradiating them and decomposing the eluted organic halogen compounds. While the microwave was irradiated, the mixed liquid stored in the liquid reservoir provided at the lower part of the catalyst filling device was cooled by a cooling coil so that the liquid temperature became 40 ° C.

  In order to maintain the temperature of the mixed solution passing through the catalyst filling device at about 60 ° C., the temperature of the mixed solution is measured by a temperature sensor provided in the temperature / output control integrated PID control device, and microwave irradiation is performed. The microwave was irradiated for 8 hours while controlling the intensity with PID. Thereafter, the microwave irradiation was stopped, and only the operation of circulating the mixed solution at room temperature was performed for 16 hours. This operation was repeated over 2 days to 8 days, and PCBs were decomposed and detoxified. During the period, the PCB concentration was measured before starting microwave irradiation and during microwave irradiation.

  After confirming that the PCB concentration has dropped below a certain value, open the lid of the pole transformer container, lift the coil inside the container, drain the liquid until it no longer drips, and then disassemble the pole transformer In accordance with 1992 Ministry of Health and Welfare Notification No. 192, Revision August 1998 No. 222; Appendix Table 2 Third, Container Body, Coil Core, Copper Coil (Copper Wire), Insulator, Insulating Paper and The amount of PCB remaining on the tree was measured.

(Comparative Example 1)
Using a pole transformer container (PCB concentration 19 to 25 mg / kg) different from that processed in Example 1, detoxification treatment was performed in the same manner as in Example 1, but during this period, the mixture was cooled. Without performing the operation and PID control of the irradiation intensity of the microwave, the microwave with the maximum output of 1.5 kW was irradiated while being turned on / off, and the temperature of the liquid mixture passing through the catalyst filling device was maintained at 60 ° C.

(Example 2)
In Example 1, the detoxification process was implemented about the coil iron core of the pole transformer which did not satisfy graduation criteria.

The iron core member was placed in the container after removing the internal member, filled with the mixed solution of isopropyl alcohol and KOH used in Example 1, heated to about 50 ° C., and stirred for 24 hours. In the same manner as in Example 1, a catalyst tank in which a catalyst filling device and a cooling coil were arranged was installed in the upper part of the container, and the catalyst filling device was filled with an activated carbon catalyst supporting 5% palladium.
Next, in the same manner as in Example 1, the mixed liquid was circulated and the microwave was intermittently irradiated to decompose the PCB and perform the detoxification treatment.

  After processing for 4 days and confirming that the PCB concentration had dropped below a certain value, the coil was lifted from the container and drained until the liquid stopped dripping, and the amount of residual PCB was measured in the same manner as in Example 1. . The results are shown in Table 1 together with Example 1. The results of Comparative Example 1 are shown in Table 2.

From the above results, it can be seen that the container and the internal member can be rendered harmless in Example 1 if at least 4 days are required. On the other hand, it can be seen that in Comparative Example 1, some of the internal members did not satisfy the graduation criteria even after the treatment for 4 days, and it took 20 days to detoxify all the containers and internal members. In other words, during microwave irradiation, the mixed liquid circulated through the catalyst filling device is cooled in a liquid reservoir at the bottom of the catalyst tank and then circulated through the container. It can be seen that the member can be detoxified.
Moreover, about the member which could not be detoxified, it turns out that it can be detoxified in a short period of time by putting the said member in a container and performing the same detoxification process.

  The present invention provides a method capable of easily detoxifying treatment under normal pressure conditions without moving the container after oil removal, and the detoxification treatment apparatus of the present invention is installed at a site such as a transformer storage. If it does so, the detoxification process of a container and an internal member can be implemented on-site. Therefore, according to the present invention, a large number of containers in which an organic halogen compound remains can be rendered harmless on a practical scale, so that the practical value of the present invention is extremely large.

1 Container 2 Liquid mixture 3 Internal member (coil)
DESCRIPTION OF SYMBOLS 4 Catalyst filling apparatus 5 Catalyst cartridge 6 Catalyst layer 7 Catalyst tank 8 Structure 9 Pump 10 Temperature sensor 11 Temperature controller 12 Microwave apparatus 13 Cooling water circulation apparatus 14 Cooling water flow regulator 15, 16, 17, 21 Line 18 Cooling coil 30 Vent

Claims (9)

For a container containing an organic halogen compound or an oil containing an organic halogen compound, after extracting the organic halogen compound or the oil containing the organic halogen compound, the container and a member installed in the container (hereinafter referred to as an internal member ) In the detoxification treatment to decompose the organic halogen compounds remaining in
The container is filled with a solution comprising a hydrogen donor and an alkali compound to elute the organic halogen compound to obtain a mixed solution, and then a part of the mixed solution is taken out and placed in the upper part of the catalyst tank. After the filling device is circulated and stored in the liquid reservoir at the bottom of the catalyst tank, the mixture is returned to the container to circulate the mixed solution, and the microwave irradiation to the mixed solution flowing through the catalyst filling device is stopped and stopped. A detoxification treatment method that decomposes an organic halogen compound repeatedly at regular intervals,
A detoxification treatment method for an organohalogen compound residual device, wherein a cooling coil is installed in a liquid reservoir in a lower part of a catalyst tank, and a mixed liquid stored in the liquid reservoir is cooled by the cooling coil during microwave irradiation.
During microwave irradiation, when the temperature (reaction temperature) of the mixed liquid flowing through the catalyst filling device becomes equal to or higher than a preset control temperature, the microwave irradiation intensity is restricted and the liquid in the lower part of the catalyst tank is The mixed liquid cooled in the pool is circulated directly to the catalyst filling device without returning to the container,
When the temperature of the liquid mixture (reaction temperature) flowing through the catalyst filling device drops below a preset temperature, the microwave irradiation intensity is restored and the mixture is cooled in the liquid reservoir at the bottom of the catalyst tank. The harmless treatment method according to claim 1, wherein the circulation of the liquid back into the container is resumed.
  The harmless treatment method according to claim 2, wherein the control temperature is a predetermined reaction temperature plus 10 ° C, and the set temperature is a predetermined reaction temperature minus 10 ° C.   The harmless treatment method according to any one of claims 1 to 3, wherein the irradiation intensity of the microwave is controlled by PID control corresponding to the management temperature and the set temperature. A member in which the organic halogen compound remains is placed in a container, and further filled with a solution comprising a hydrogen donor and an alkali compound to elute the organic halogen compound to obtain a mixed solution, and then a part of the mixed solution is taken out. The catalyst filling device disposed in the upper part of the catalyst tank is circulated, stored in the liquid reservoir at the lower part of the catalyst tank, returned to the container, and the mixed liquid is circulated and mixed through the catalyst filling apparatus. It is a detoxification treatment method for decomposing an organic halogen compound remaining in the member by repeating microwave irradiation to the liquid and stopping at a constant interval,
A detoxifying treatment method for an organic halogen compound residual member, wherein a cooling coil is installed in a liquid reservoir at a lower portion of a catalyst tank, and a mixed liquid stored in the liquid reservoir is cooled by the cooling coil during microwave irradiation.   The detoxification method according to claim 5, wherein the member is an iron core, a copper coil, an insulator, or insulating paper. For a container containing an organic halogen compound or an oil containing an organic halogen compound, after extracting the organic halogen compound or the oil containing the organic halogen compound, the organic halogen compound is eluted by filling a solution composed of a hydrogen donor and an alkali compound. A detoxification treatment apparatus for decomposing an organic halogen compound remaining in the container and a member installed in the container (hereinafter referred to as an internal member ) ,
(A) a catalyst filling device;
(B) a catalyst tank in which the catalyst filling device is accommodated in the upper part, and the lower part is a liquid reservoir;
(C) A container circulation system for taking out the mixed liquid in the container, supplying it to the catalyst filling device, and then returning it to the container;
(D) a microwave device for irradiating the catalyst filling device with microwaves;
(E) A detoxification treatment apparatus comprising at least a cooling coil for cooling a mixed liquid stored in a liquid reservoir at a lower part of a catalyst tank during microwave irradiation.
further,
(F) a temperature sensor for measuring the temperature of the mixed liquid flowing through the catalyst filling device;
(G) During microwave irradiation, when the temperature of the mixed liquid flowing through the catalyst filling device becomes equal to or higher than a preset management temperature value, the temperature of the mixed liquid becomes equal to or lower than a preset set temperature. A microwave control device that limits microwave irradiation to
(H) a catalyst tank circulation system for removing the mixed liquid from a liquid reservoir at the bottom of the catalyst tank, supplying the mixed liquid to the catalyst filling device, and then returning the mixture to the catalyst tank;
(I) a system controller that circulates the mixed liquid in the catalyst circulation system while limiting the irradiation intensity of the microwave;
The detoxification processing apparatus according to claim 7, comprising: The harmless device according to claim 8, wherein the microwave control device controls the irradiation intensity of the microwave by PID control corresponding to a management temperature and a set temperature of the mixed liquid flowing through the catalyst filling device. Processing equipment.

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