JP2007105063A - Method of decomposing organic halogen compound and microwave built-in type decomposition system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a system for decomposing an organic halogen compound, capable of detoxicating the oil, in which the organic halogen compound such as insulating oil used in a pole transformer is mixed, in a pole transformer container in a short period of time without requiring the labor of separating a catalyst and with a low possibility of generation of a side reaction product. <P>SOLUTION: The method is for decomposing the organic halogen compound included in the oil filled or stored in the container. In the method, a mixture liquid obtained by adding a hydrogen donor and an alkaline compound to the oil including the halogen compound is circulated in the container while letting the mixture liquid into a catalyst filled device attached to a lid body of the container, and microwaves are applied to the mixed liquid inside the container to decompose the organic halogen compound in the oil. The microwave built-in type decomposition system comprises at least the lid body with the catalyst filled device and a microwave oscillator to be set inside the container which is filled with the oil or in which the oil is stored, and a feeding means for feeding the oil, etc. in the container to the catalyst filled device. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an organic halogen compound decomposition treatment method and decomposition system for decomposing an organic halogen compound contained in oil filled or stored in a container to render the oil harmless, and more specifically, in a pole transformer The present invention relates to an organic halogen compound decomposition treatment method and a decomposition treatment system for degrading polychlorinated biphenyl contained in an insulating oil filled or stored in the oil to render the oil harmless.

  Among various organic halogen compounds, polychlorinated biphenyl (hereinafter sometimes 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, importation, Use is prohibited. However, after that, tens of thousands of tons of PCBs are left untreated without determining an appropriate disposal method. PCB decomposes PCB safely technically because chlorinated dibenzo-p-dioxin (PCDD) and dibenzofuran (PCDF), which are highly toxic dioxins, are by-produced at high temperature (30 to 750 ° C) decomposition. This is difficult, and various safe and efficient decomposition methods for PCBs have been studied for many years.

  For example, Patent Document 1 discloses an aromatic chlorine compound by irradiating microwaves while blowing hydrogen gas into a reaction system including a platinum group catalyst and an aromatic chlorine compound supported on a carbon-based catalyst carrier. A method for dechlorination has been proposed.

  In Patent Document 2, a hydrocarbon oil containing a small amount of PCB is mixed with a high-boiling and heat-resistant alkaline polar solvent (1,3-dimethyl-2-imidazolidinone, in the presence of an alkaline substance such as sodium ethoxide or NaOH. A method is described in which PCB is removed from hydrocarbon oil by separating the hydrocarbon oil and solvent after contacting with sulfolane) at 100 to 300 ° C.

  Patent Document 3 discloses a pole transformer containing PCB by heating a pole transformer containing PCB, an autoclave containing water and an oxidizing agent, and oxidatively decomposing PCB with water in a supercritical state. A method for detoxifying the transformer has been proposed. In this method, without separating the insulating oil from the pole transformer, it is detoxified as it is, and the PCB contained in the insulating oil in the transformer and the PCB contained in the insulating oil adhering to the transformer are simultaneously treated. The purpose is to detoxify all at once.

  Further, in Patent Document 4, the insulating oil is extracted from the pole transformer using the insulating oil containing PCB, and then washed with water and further washed with a hydrocarbon-based solvent. A method of detoxification has been proposed. In this method, the separated oil is detoxified by heating and stirring using alkali metal tertiary butoxide as a reactant. The purpose is to efficiently and safely recover the insulating oil containing PCB from the distribution pole transformer, and to reduce the space required for storage of the huge distribution pole transformer.

  Furthermore, the present inventors have proposed a method of decomposing an organic halogen compound at room temperature using a catalyst filling device installed in a container in Patent Document 5.

Japanese Unexamined Patent Publication No. 2001-19646 (Claim 1, Example 1 of paragraph number 0009) JP-A-6-25691 (Claim 1, paragraph number 0004, Table 1 on page 3) JP 2000-116814 A (Claim 1, FIG. 1 on page 6, paragraph number 0008, etc.). JP 2001-246014 A (Claim 1, Claim 9, Paragraph Number 0013, Paragraph Number 0030, page 4, right column bottom line 4 to end line). Japanese Patent No. 3626960

  However, in the method described in Patent Document 1, it is necessary to supply hydrogen gas from the outside to a reaction system containing an aromatic chlorine compound, which is not preferable as a practical technique. In addition, the solvent DMI used in the method described in Patent Document 2 is as expensive as 2000 yen / kg, and in this method, the residual PCB ratio is large, and the reaction time is lengthened in order to sufficiently perform dechlorination. Since it is necessary, it is not suitable for mass processing of PCBs.

  The method described in Patent Document 3 has the advantage that it can be detoxified without separating the insulating oil from the transformer, but the whole pole transformer is placed in the pressure vessel, and the pressure vessel is heated by adding water and an oxidizing agent. By doing so, the PCB is oxidized and decomposed in a supercritical state, so that a large-scale apparatus is required. Moreover, although patent document 4 is disclosing about the decomposition processing method of the oil extracted from the pole transformer, it does not mention what decomposes | disassembles PCB in a container at all.

  Furthermore, the conventional process is batch-type, so the equipment becomes very large to process in large quantities, and the catalyst is separated from the waste oil after the detoxification treatment because the powdered catalyst is put into the oil as it is. However, it took a lot of work. In addition, when a fixed bed type catalyst is used, there is a problem that the chance of contact with PCB is reduced and the reaction does not proceed satisfactorily. Furthermore, although it is effective to irradiate ultrasonic waves to remove the influence of the clusters in the oil, the batch method has a problem that the catalyst is also destroyed.

  In addition, because construction is required for the construction of PCB processing facilities, it is possible to detoxify PCBs at sites such as transformer storage, and to process PCBs safely and in large quantities at low cost. Development of a method that can be decomposed has been desired. In that respect, the method described in Patent Document 5 is an excellent treatment method, but there is a problem when it is desired to decompose oil in a short time.

  The present invention has been made in view of the above-described conventional problems, and oil mixed with an organic halogen compound such as insulating oil used in a pole transformer is harmless in a container such as a pole transformer in a short period of time. It is an object of the present invention to provide an organic halogen compound decomposition treatment method and a decomposition treatment system that can be subjected to a chemical conversion treatment, and that does not require the effort of separating the catalyst and has a low possibility of generating a side reaction product.

  As a result of intensive studies to solve the above problems, the present inventors have added a hydrogen donor and an alkali to the oil in the pole transformer in which a trace amount of the organic halogen compound is mixed, and the mixed solution is filled with the built-in catalyst. While circulating in the equipment, it is circulated in the container, and the catalyst is irradiated with microwaves from a microwave oscillator attached to the container lid to easily detoxify trace organic halogen compounds in the oil in a short period of time. The present invention has been completed.

That is, the present invention is as follows.
1) A decomposition treatment method for decomposing an organic halogen compound contained in oil filled or stored in a container,
A container lid equipped with a catalyst filling device and a microwave oscillator is attached to the container,
While circulating the mixed liquid obtained by adding a hydrogen donor and an alkali compound to the oil containing the organic halogen compound in the container while circulating through the catalyst filling device installed in the container,
A method for decomposing an organic halogen compound, comprising decomposing an organic halogen compound in oil by irradiating the catalyst layer with microwaves in the container;
2) The organic halogen according to 1), wherein the hydrogen donor is at least one compound selected from the group consisting of a heterocyclic compound, an amine compound, an alcohol compound, a ketone compound, and an alicyclic compound. Compound decomposition method,
3) The method for decomposing an organic halogen compound according to 1) or 2), wherein the addition amount of the hydrogen donor is 5 to 50% (vol) as a ratio to the oil containing the organic halogen compound,
4) The decomposition of the organic halogen compound according to any one of 1) to 3), wherein the alkali compound is at least one compound selected from the group consisting of caustic soda, caustic potash, sodium alkoxide, potassium alkoxide, and calcium hydroxide. Processing method,
5) The method for decomposing an organic halogen compound according to any one of 1) to 4) above, wherein the addition amount of the alkali compound is 0.1 to 40% (w / v) as a ratio to the hydrogen donor,
6) The method for decomposing an organic halogen compound according to any one of 1) to 5) above, wherein the hydrogen donor and the alkali compound added to the oil are obtained by dissolving an alkali compound in the hydrogen donor.
7) The catalyst according to any one of 1) to 6), wherein the catalyst is at least one compound selected from the group consisting of a carbon crystal compound, a metal-supported carbon compound, a metal-supported oxide, and a metal-supported composite oxide. Organic halogen compound decomposition method,
8) The method for decomposing an organic halogen compound according to any one of 1) to 7) above, wherein the oil is a hydrocarbon oil and the organic halogen compound is polychlorinated biphenyl.
9) The organic halogen compound decomposition treatment method according to any one of 1) to 8), wherein the container is a pole transformer, and the catalyst filling device is disposed on a winding in the pole transformer,
10) A decomposition treatment system for decomposing an organic halogen compound contained in oil filled or stored in a container,
A container lid comprising a microwave oscillator and a catalyst filling device that can be installed in the container;
A microwave built-in decomposition processing system comprising at least supply means for supplying oil or the like in the container to the catalyst filling device.

  According to the method for decomposing an organic halogen compound of the present invention, an oil mixed with an organic halogen compound filled or stored in a container, a hydrogen donor, and an alkali compound are mixed, and the obtained mixed solution is placed in the container. Circulating in the container while circulating through the arranged catalyst filling device and irradiating with microwaves in the container, the organic halogen compounds can be decomposed in a short time under normal temperature and pressure, and the contaminated oil is recovered. Therefore, it is not necessary to provide a new device installation space even at a site such as a transformer store, and the dehalogenation treatment can be performed on the spot. In addition, since the decomposition process can be performed simply by attaching the lid provided with the microwave oscillator and the catalyst filling device to the container, the oil in the container can be sequentially detoxified only by moving the cover.

  In addition, by selecting a hydrogen donor and / or an alkali compound to be used for the decomposition treatment, the organic halogen compound can be decomposed with high efficiency. The decomposition process can be performed with higher efficiency. Moreover, the initial decomposition rate of the organic halogen compound can be increased by adding a solution in which an alkali compound is previously dissolved in a hydrogen donor to the oil.

  Further, by using at least one compound selected from a carbon crystal compound, a metal-supported carbon compound, a metal-supported oxide, and a metal-supported composite oxide as a catalyst used in the decomposition process, the decomposition process of the organic halogen compound is highly efficient. The processing cost can be reduced.

The organic halogen compound decomposition treatment system of the present invention is an organic halogen compound decomposition treatment system for detoxifying an organic halogen compound-containing oil filled or stored in a container,
A container lid comprising a microwave oscillator and a catalyst filling device that can be installed in the container;
And at least supply means for supplying oil or the like in the container to the catalyst filling device, so that a container lid is placed on the pole transformer, and the organic halide mixed oil is circulated through the catalyst filling device. By irradiating the waves, no additional equipment is required, and the organic halogen compound in the oil can be decomposed in the container in a short period of time.

  Hereinafter, the organic halogen compound decomposition treatment method and decomposition treatment system according to the present invention will be described in detail with reference to the drawings.

  The decomposition treatment method and decomposition treatment system of the present invention can be installed in a container filled or stored with an oil containing an organic halogen compound (content: 1 ppm to 10,000 ppm, preferably 1 ppm to 500 ppm). After attaching a lid with a catalyst filling device and a microwave oscillator, the oil in the vessel is circulated through the catalyst filling device and the organohalogen compound is brought into contact with the catalyst, while the catalyst layer is micro-coated in the vessel. Waves are irradiated to decompose organic halogen compounds in oil. In order to accelerate the decomposition process of the organic halogen compound, a hydrogen donor and an alkali compound are mixed with the oil. Examples of the container include a pole transformer, a large transformer, an OF cable oil tank, and the like. A pole transformer is preferable.

  Examples of the organic halogen compound that is the subject of the decomposition treatment of the present invention include polychlorinated biphenyls (PCB) and dioxins, and the type thereof is not particularly limited, but is preferably PCBs. is there. 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.

  The decomposition treatment method of the present invention is suitable for decomposition treatment of oil containing a small amount or a small amount of PCBs, which are generally difficult to dehalogenate, among organic halogen compounds. Examples of the oil include hydrocarbon oils, and specific examples include electric insulating oil, oil for heat medium, lubricating oil, or mineral oil obtained by extracting an organic halogen compound contained in a solid.

  FIG. 1 is a schematic view showing an embodiment of the decomposition treatment system of the present invention, and shows an example of decomposition treatment of an organic halogen compound-containing oil filled in a pole transformer 6. As shown in FIG. 1, the decomposition treatment system 1 of the present invention is a mixed liquid obtained by adding a hydrogen donor and an alkali compound to an oil containing an organic halogen compound (hereinafter referred to as “treatment liquid”). 7 is provided with a container lid 8 including a pole transformer 6, a microwave oscillator 20, and a catalyst filling device 10 that can be installed in the pole transformer 6, and a liquid 7 to be treated is supplied to the catalyst filling device. The supply means (pump) 18 is configured as a main component. The microwave oscillator 20 is attached to the outer surface of the container lid 8. The catalyst filling device 10 is provided with a thermocouple 21 for a thermometer and a thermocouple 23 for a temperature controller, and the container 6 is provided with a thermocouple 22 for a thermometer.

  In FIG. 1, reference numeral 15 denotes the liquid level of the liquid to be processed filled in the pole transformer 6. The mounting position of the pump 18 is not particularly limited, and may be provided either outside or inside the pole transformer 6 as illustrated. Each pump is provided with a supply line 19 for supplying the liquid 7 to be treated to the catalyst filling device 10 via the pump 18 for each pump. Thus, the liquid to be treated is supplied to the catalyst filling device, and the organic halogen compound is brought into contact with the catalyst.

  Although the pole transformer 6 is not shown, the pole transformer 6 may include a supply line for a hydrogen donor and an alkali compound. Alternatively, a device (pre-tank) (not shown) for storing a hydrogen donor and an alkali compound premixed and storing the alkali compound dissolved in the hydrogen donor is installed, and the hydrogen donor is transferred from the device to the pole transformer 2. And a supply line (not shown) for supplying an alkali compound may be provided.

  The catalyst filling device 10 shown in FIG. 1 is attached to the container lid 8 by a flange 17. In the catalyst filling device 10, a catalyst layer 12 filled with a later-described catalyst capable of decomposing an organic halogen compound is formed on the countersink plate 11. The liquid 7 to be treated is introduced into the upper part of the catalyst layer 12 formed in the catalyst filling device 10 through the circulation pipe 19, the pump 18, and the supply pipe as indicated by the arrows in the figure. The introduced liquid to be processed flows through the catalyst layer 12, and the liquid 7 to be processed after flowing through the catalyst layer flows out from the lower part of the catalyst filling device 10 in the direction of the arrow through the discharge pipe 13. Thus, when the liquid to be treated comes into contact with the catalyst, the organic halogen compound in the liquid to be treated is decomposed. An overflow liquid discharge pipe 14 corresponding to the liquid level 16 is provided in the catalyst filling device 10. Thereby, it can avoid that the to-be-processed liquid overflows in a catalyst filling apparatus.

  Since the liquid level 16 in the catalyst filling device 10 is maintained higher than the liquid level 15 in the container 6, the liquid passing through the catalyst packed bed can be returned to the pole transformer by its own weight. The discharge means is not required simply by providing the liquid supply means to the catalyst filling device.

  FIG. 2 is a top view of the periphery of the eye plate 11 of the catalyst filling apparatus 10 shown in FIG. The liquid to be treated passes through the flow hole 11a provided in the countersink plate 11 formed of a SUS mesh filter or the like, flows out downward, and then overflows from the discharge pipe 13. The number of the flow holes 11a is not limited, but it is preferable to be present in the entire catalyst filling device so that the liquid to be treated spreads uniformly. The size of the flow hole 11 is not limited, but the flow hole 11 has a size (50 μm to 5 mmφ, more preferably about 0.1 mm to 1 mmφ) that allows the liquid to be treated to flow and hold the catalyst. preferable.

  The catalyst filling device used in the decomposition treatment system of the present invention is not particularly limited in shape and size as long as it is a size that can be installed inside a container such as a pole transformer. Although it may be, it is desirable to arrange | position on the internal winding 2 of the pole transformer 6 so that it may illustrate in FIG. Since the liquid flow cross-sectional area of the catalyst layer can be designed to be large according to the inner diameter of the pole transformer, the time required for decomposition can be shortened by increasing the liquid flow rate even when the space velocity (SV) is constant. It is.

  The entire catalyst filling device does not need to be immersed in the liquid to be treated, and the upper part thereof may be above the liquid surface of the liquid to be treated. As shown in FIG. 1, when the catalyst layer 12 is immersed in the liquid 7 to be treated, the entire catalyst packed layer is easily fluidized, so that the short path of the liquid to be treated is reduced and the oil is harmless in a short time. It is thought that it can be made.

  Moreover, since the microwave oscillator 20 is attached to the container outer surface side of the container lid 8, the catalyst layer 12 can be irradiated with microwaves from above in the container. For this reason, the to-be-processed liquid which distribute | circulates a catalyst layer contacts the catalyst heated with the microwave irradiated. Thus, the organohalogen compound in the liquid to be treated is decomposed at a much faster rate than when not irradiated with microwaves.

  The liquid 7 to be treated introduced into the catalyst filling device 10 flows out into the pole transformer 6 while continuously flowing through the catalyst layer 12 of the catalyst filling device. Circulation with the device 10 is possible. The liquid to be processed returned to the pole transformer is mixed with the liquid to be processed remaining in the pole transformer. The liquid to be treated is circulated between the pole transformer and the catalyst filling device until the organic halogen compound in the mixed liquid to be treated becomes a predetermined concentration or less.

  Due to the above circulation operation, the high temperature liquid to be processed that has passed through the catalyst layer for microwave decomposition is mixed with the liquid to be processed in the pole transformer containing a large amount of liquid to be processed, and the liquid temperature is lowered. It becomes possible to irradiate microwaves with an output close to full output. Therefore, the decomposition efficiency of the organic halogen compound is improved as compared with the case where the liquid to be treated is circulated without being circulated.

  In addition, a cooling device such as a condenser can be installed as a cooling means in at least one arbitrary place on the pipe 19. As a result, the high temperature liquid to be processed after passing through the microwave decomposition catalyst layer can be cooled, and the low temperature liquid to be processed can be supplied by the microwave decomposition catalyst layer. It becomes possible to irradiate waves. Therefore, the decomposition efficiency of the organic halogen compound is further improved as compared with the case where no cooling means is provided.

  However, since the microwave irradiation in the catalyst filling device may be performed as necessary, the number and timing thereof are not limited. From the viewpoint of rapid processing, the microwave irradiation is preferably continuous irradiation or irradiation for as long as possible. However, in consideration of driving safety, cost, securing personnel, etc., it is preferable to perform microwave irradiation only in the daytime. In the latter case, it is better to irradiate microwaves during the daytime and only circulate without irradiation at nighttime.

  In addition, the decomposition processing system of the present invention includes a cluster destruction device such as an ultrasonic generator capable of breaking a cluster formed in the liquid 7 to be processed, for example, in the vicinity of the liquid inlet of the catalyst filling device 10. (The illustration is omitted). When the solvent in which the organic halogen compound is dissolved is an oil such as insulating oil, the organic halogen compound and the solvent molecule may form a cluster, which may inhibit the decomposition of the organic halogen compound. Providing a cluster destruction device such as an ultrasonic generator is considered to have the effect of destroying these clusters and exposing the organic halogen compounds to facilitate the decomposition reaction.

  Next, one embodiment of the method for decomposing an organic halogen compound according to the present invention, together with the method for using the above decomposing process system, will be described in detail with reference to FIG.

  First, a liquid to be treated is prepared by adding a hydrogen donor and an alkali compound, which will be described later, to the pole transformer 6 containing oil mixed with a trace amount or a small amount of PCB shown in FIG. Stir and mix inside the container as necessary. Next, the lid body 8 to which the catalyst filling device 10 and the microwave oscillator 20 are attached is attached to the container 6 and it is confirmed that there is no liquid leakage or microwave leakage.

  Next, the liquid 7 to be treated is continuously passed through the catalyst filling device 10 filled with the catalyst to dehalogenate the organic halogen compound. The distribution time is not particularly limited, but is usually 1 to 2 weeks.

  The reaction atmosphere is more preferably carried out in an inert gas because undesirable side reactions do not occur. However, since it may be difficult to procure an inert gas depending on the processing environment of the contaminated oil, the reaction can be performed in a natural atmosphere.

  The output, frequency, and irradiation method of the microwave applied to the catalyst layer 12 are not particularly limited, and may be electrically controlled so that the reaction temperature can be maintained within a predetermined range. When the output is too low, the amount of hydrogen generation is reduced, and when the output is too high, the utilization rate of the microwave is deteriorated. Therefore, it is desirable to set the range of 10 W to 20 kW while being electrically controlled. The microwave frequency is preferably 1 to 300 GHz. In the frequency range below 1 GHz or above 300 GHz, the catalyst and the hydrogen donor are not sufficiently heated. Microwave irradiation may be either continuous irradiation or intermittent irradiation, but it is preferable to perform continuous irradiation while being electrically controlled. 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.

  The reaction temperature in the catalyst filling device is desirably 200 ° C. or less, preferably 100 ° C. or less, particularly preferably 15 to 80 ° C. By setting the reaction temperature to 15 ° C. or higher, the decomposition reaction proceeds. On the other hand, when it exceeds 200 ° C., the dechlorination reaction proceeds sufficiently, but by-products are easily generated, and the economy is inferior.

  Further, the liquid circulation can be continued even when the microwave is not irradiated. The reaction temperature in this case is not particularly limited, but it is preferable to carry out without installing a heating device in order to simplify the apparatus. Usually 15-25 ° C. However, from the viewpoint of increasing the dehalogenation efficiency while suppressing side reaction products, it can be appropriately heated.

  By performing the above decomposition treatment, the content of the organic halogen compound in the oil can be reduced to 0.5 ppm or less at 25 ° C. for about one week with respect to the undegraded oil.

  Examples of the “hydrogen donor” added to the oil in the present invention include organic hydrogen donors such as 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 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 particularly preferable from the viewpoint of decomposition efficiency.

  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 decomposition treatment method of the present invention, the hydrogen donor and alkali compound described above may be pre-stirred in advance to dissolve the alkali compound in the hydrogen donor.

  The hydrogen donor is preferably used in an amount of 5 to 50% (vol), more preferably 10 to 40% (vol), relative to the organic halogen compound-containing oil. When the amount of the hydrogen donor is less than 5%, the viscosity of the solution increases and the decomposition reaction does not proceed. On the other hand, when the amount of the hydrogen donor exceeds 50%, the reaction proceeds sufficiently, but there is no practical meaning and the container may exceed the allowable amount.

  Moreover, it is preferable that an alkali compound shall be 0.1-40% (w / v) as a ratio with respect to a hydrogen donor, More preferably, it is 0.2-20% (w / v). If the ratio is less than 0.1%, the decomposition reaction does not proceed. If it exceeds 40%, the alkali compound cannot be completely dissolved. The alkali compound is preferably used in an amount of 0.02 to 10% (w / v) based on the organic halogen compound-containing oil.

  In the decomposition treatment method of the present invention, when the oil in the container, the hydrogen donor and the alkali compound are mixed, stirring from the outside by shaking, stirring from the inside by a stirrer, microscopic stirring by ultrasonic waves, etc. Any method may be used. As agitation from the outside by shaking, for example, a method of vibrating a container such as a pole transformer using a vibrating stirrer, a shaking table, a shaker or the like (for example, parallel in the vertical and / or horizontal direction) A method of vibrating, a method of rotating and the like) and the like. Examples of the stirring from the inside by the stirrer include a method of stirring the liquid to be treated using a stirrer such as a stirring blade or a magnetic stirrer. In the case of stirring, either continuous stirring or intermittent stirring may be employed.

  The catalyst charged in the catalyst filling apparatus of the present invention can be used without limitation as long as it can accelerate the dehalogenation reaction of polychlorinated biphenyl, and the type thereof is not particularly limited. An inorganic catalyst is preferable to an organic catalyst because it has a long catalyst life and is stable even in the presence of an alkali compound. Preferred specific examples of the inorganic catalyst include composite metal oxides, carbon crystal compounds, metal-supported carbon compounds, metal-supported oxides, metal-supported composite metal oxides and metal oxides from the viewpoint of increasing the dehalogenation efficiency. Preferably used. Among these, from the viewpoint of high safety in an alkaline atmosphere, a carbon crystal compound, a metal-supported carbon compound, a metal-supported oxide, and a metal-supported composite oxide are preferable, and a metal-supported carbon compound having high microwave absorption is particularly preferable. These catalysts can be used individually or in combination of 2 or more types. Further, a regenerated catalyst regenerated by the above method may be used.

  Here, examples of the carbon crystal compound include graphite, carbon nanotubes (both including and not including metal), fullerene, and the like.

  Moreover, as said metal carrying | support carbon compound, if it is a carbon compound which carry | supported the metal, it can be used without a restriction | limiting, The metal carrying amount is 0.1-20 wt% with respect to the catalyst whole quantity, More preferably, it is 0.1 It is good that it is -10 wt%. Examples of the supported metal include iron, silver, platinum, ruthenium, palladium, rhodium and the like, and palladium, ruthenium, and platinum are preferable from the viewpoint of increasing the dehalogenation efficiency. 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 metal-supported oxide and metal-supported composite oxide can be used without limitation as long as they are metal-supported oxides and composite oxides. It is the same. Specific examples of the metal-supported oxide include Pd / TiO ₂ (palladium-supported titanium dioxide). Specific examples of the metal-supported composite oxide include Pd / SiO ₂ .Al ₂ O ₃ (palladium-supported silica-alumina).

  The catalyst such as a metal-supported carbon compound may be granular or honeycomb. In the case of granular, it is necessary to fix the upper and lower sides of the column with a mesh or the like, and the particle diameter in that case 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. More preferably, it is 150 μm to 5 mm. The catalyst particles should have the same particle size as possible.

  According to the decomposition treatment method and system of the present invention, since the concentration of the organic halogen compound mixed in the oil is decomposed to 0.5 ppm or less in a short time, the oil after the decomposition treatment is collected and post-treated. Therefore, it can be reused as fuel.

  According to the organic halogen compound decomposition treatment method of the present invention, the organic halogen compound is decomposed and dehalogenated at a slightly lower rate than when hydrogen gas or heat is applied from the outside. Although the mechanism is not clear, it is considered that the alkali compound promotes the dehalogenation reaction of the organic halogen compound, and the hydrogen radical from the hydrogen donor enters therein.

1 is a schematic front view showing one embodiment of an organic halogen compound decomposition treatment system according to the present invention. It is a top view of the periphery of the countersink plate of the catalyst filling apparatus according to the present invention.

Explanation of symbols

1 Disassembly treatment system 2 Pillar transformer internal winding 6 Pillar transformer (container)
7 Liquid to be treated 8 Container lid 10 Catalyst filling device 11 Plate plate 11a Flow hole 12 Catalyst layer 13 Discharge piping 14 Overflow liquid discharge piping 15 Liquid level level in column top transformer 16 Liquid level in catalyst filling device 17 Flange 18 Pump 19 Circulating piping 20 Microwave oscillator 21, 22 Thermocouple for thermometer 23 Thermocouple for temperature controller

Claims (10)

A decomposition treatment method for decomposing an organic halogen compound contained in oil filled or stored in a container,
A container lid equipped with a catalyst filling device and a microwave oscillator is attached to the container,
While circulating the mixed liquid obtained by adding a hydrogen donor and an alkali compound to the oil containing the organic halogen compound in the container while circulating through the catalyst filling device installed in the container,
A method for decomposing an organic halogen compound, comprising decomposing an organic halogen compound in oil by irradiating the catalyst layer with microwaves in the container. 2. The organic halogen compound according to claim 1, wherein the hydrogen donor is at least one compound selected from the group consisting of a heterocyclic compound, an amine compound, an alcohol compound, a ketone compound, and an alicyclic compound. Decomposition method. The method for decomposing an organic halogen compound according to claim 1 or 2, wherein the addition amount of the hydrogen donor is 5 to 50% (vol) as a ratio with respect to the oil containing the organic halogen compound. The method for decomposing an organic halogen compound according to claim 1, wherein the alkali compound is at least one compound selected from the group consisting of caustic soda, caustic potash, sodium alkoxide, potassium alkoxide, and calcium hydroxide. The method for decomposing an organic halogen compound according to any one of claims 1 to 4, wherein the addition amount of the alkali compound is 0.1 to 40% (w / v) as a ratio to the hydrogen donor. The method for decomposing an organic halogen compound according to any one of claims 1 to 5, wherein the hydrogen donor and the alkali compound added to the oil are obtained by dissolving an alkali compound in the hydrogen donor. The organohalogen compound according to any one of claims 1 to 6, wherein the catalyst is at least one compound selected from the group consisting of a carbon crystal compound, a metal-supported carbon compound, a metal-supported oxide, and a metal-supported composite oxide. Decomposition method. The method for decomposing an organic halogen compound according to any one of claims 1 to 7, wherein the oil is a hydrocarbon oil and the organic halogen compound is polychlorinated biphenyl. The method for decomposing an organic halogen compound according to any one of claims 1 to 8, wherein the container is a pole transformer, and the catalyst filling device is disposed on a winding in the pole transformer. A decomposition treatment system for decomposing an organic halogen compound contained in oil filled or stored in a container,
A container lid comprising a microwave oscillator and a catalyst filling device that can be installed in the container;
A microwave built-in decomposition processing system comprising at least supply means for supplying oil or the like in the container to the catalyst filling device.

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