JP2007222696A - Catalyst column for micro-wave reaction and decomposition treatment method using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a catalyst column for a micro-wave reaction capable of shortening a reaction requirement time by promoting the micro-wave reaction by increasing an effective irradiation area of a micro-wave in a chemical reaction utilizing the micro-wave, and a decomposition treatment method for an organic halogen compound using it. <P>SOLUTION: In the catalyst column (10) for the micro-wave reaction, an inner wall (12) becoming a catalyst contact surface is constituted by a micro-wave permeating heat resistant material and a wave guide passage (14) is formed. The catalyst is filled in a catalyst filling tank (13) provided in the catalyst column and a liquid to be treated containing the organic halogen compound is circulated in the catalyst layer and is discharged to a lower side. It is irradiated with the micro-wave from above the wave guide passage (14) to decompose the organic halogen compound. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a catalyst column for microwave reaction and an organic halogen compound decomposition method using the same.

  It is known that the effects of promoting some chemical reactions or improving the efficiency can be obtained by microwave irradiation. Among organic halogen compounds, polychlorinated biphenyl (hereinafter abbreviated as PCB) is particularly difficult to decompose. There is also proposed a decomposition method using a microwave reaction.

For example, Patent Document 1 discloses a method of dechlorinating PCB by mixing a hydrogen donor with insulating oil containing a trace amount of PCB and irradiating microwaves in the presence of an alkali compound and an inorganic catalyst. Has been. Patent Document 2 discloses a reaction solution in which a column is filled with at least one catalyst selected from a carbon crystal compound and a compound in which a metal is supported on a support, and contains a PCB, an alcohol having a boiling point of 100 ° C. or less, and an alkali compound. Has been disclosed in which PCB is dechlorinated by irradiating the catalyst-filled column with microwaves while circulating the catalyst through the catalyst-filled column.
Japanese Patent No. 3678738 Japanese Patent No. 3678740

  However, when the amount of catalyst is increased to increase the decomposition efficiency of PCB, etc., and the catalyst layer is thickened, the effect of promoting the reaction by microwaves can be obtained at a certain depth from the microwave irradiation surface. However, since microwaves are difficult to reach, it can only contribute as a room temperature decomposition reaction, resulting in a slow decomposition reaction.

  The present invention has been made in view of the above problems, and in a chemical reaction using microwaves, the effective irradiation area of the microwave is increased, thereby promoting the microwave reaction and shortening the reaction time. It is an object of the present invention to provide a catalyst column for microwave reaction and a method for decomposing an organic halogen compound using the same.

  As a result of intensive studies to achieve the above object, the inventors of the present invention have formed a catalyst column contact surface made of a microwave permeable heat resistant material and a surface made of a heat resistant material. It has been found that by forming a waveguide so that microwaves can be irradiated, the effective irradiation area of the microwaves can be increased and a reaction promoting effect can be obtained.

  That is, the present invention provides a catalyst column for microwave reaction, wherein all or part of the contact surface with the catalyst is made of a microwave-permeable heat-resistant material and a waveguide is formed. I will provide a. In the above-mentioned catalyst column for microwave reaction, a waveguide may be formed in the center of the catalyst column, or a waveguide is formed in a catalyst non-packing space formed by partitioning the inside of the catalyst column with a partition plate. However, it is preferable that a catalyst packed tank is provided on the outer peripheral surface of the catalyst column, the interior is used as a catalyst unfilled space, and the catalyst unfilled space is used as a waveguide. The catalyst column can be used for various microwave reactions, but exhibits excellent effects when used for a decomposition reaction of an organic halogen compound.

  Further, the present invention provides a catalyst column for microwave reaction, wherein all or part of the catalyst contact surface is made of a microwave-permeable heat-resistant material and a waveguide is formed. A decomposition treatment method characterized by forming a catalyst layer, circulating a liquid to be treated containing an organic halogen compound in the catalyst layer, and irradiating microwaves from above the waveguide to decompose the organic halogen compound. provide. In the decomposition treatment method, the liquid to be treated is preferably a mixed liquid containing an organic halogen compound, a hydrogen donor and an alkali compound, and the organic halogen compound is preferably polychlorinated biphenyl.

  According to the present invention, the effective microwave irradiation area is increased, the microwave can be applied to the entire catalyst layer, and the contact time with the catalyst can be kept long, so that the microwave reaction is promoted. As a result, the reaction time is shortened. Moreover, the microwave decomposition reaction of the hardly decomposable PCB can be completed in a shorter time than conventional.

  In the present invention, the microwave-permeable heat-resistant material is not particularly limited, and may be ceramic; Teflon (registered trademark), polyphenylene sulfide (PPS), polyphenylene sulfide (PPSU) as long as it is a material that transmits microwaves. ), Polyarylate (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, and other heat-resistant resins; glass and other materials that do not have a dipole or a small dipole moment Charge; or the like can be used. Microwaves are transmitted to the depth of the catalyst layer through these materials.

  Next, a catalyst column for microwave reaction according to the present invention and a decomposition treatment method using the same will be described in detail with reference to the drawings. 1 to 7 are explanatory diagrams showing a schematic configuration of a catalyst column for microwave reaction according to the present invention, in which FIGS. 1 to 3 are not filled with a catalyst, and FIGS. The filled state is shown.

Example 1
FIG. 1 is an external view showing a schematic configuration of a catalyst column for microwave reaction according to Example 1 of the present invention. In this example, a waveguide is formed at the center of the catalyst column. In the figure, 10 is a catalyst column, 11 is an outer wall of the column, 12 is an inner wall made of Teflon, 13 is a catalyst filling tank, and 14 is a waveguide. A flow hole is formed. The waveguide 14 is not filled with a catalyst.

  The microwave irradiated to the catalyst column 10 from the direction of the arrow is directly irradiated to the upper surface of the catalyst filled in the catalyst filling tank 13 and also to the side surface of the catalyst layer through the waveguide 14 and the inner wall 12. Become so. Thereby, compared with irradiating a microwave from the upper part, an irradiation area can be increased and the output microwave can be efficiently applied to a catalyst.

  Further, in the example of FIG. 1, it is sufficient that at least the inner wall 12 is formed of a heat-resistant material that transmits microwaves, and the bottom surface provided with the outer wall 11 and the flow holes is formed of a heat-resistant material that transmits microwaves. Alternatively, it may be formed of a heat-resistant material such as metal (preferably a material such as brass, copper, or bronze having excellent corrosion resistance) or stainless steel.

  In the example of FIG. 1, a double cylindrical structure is illustrated, but a double rectangular shape may be used, and an appropriate shape can be designed according to the design of the reaction apparatus.

(Example 2)
FIG. 2 is an external view showing a schematic configuration of a catalyst column for microwave reaction according to Example 2 of the present invention. In this example, a waveguide is formed at the center of the catalyst column. In the figure, 20 is a catalyst column, 21 is an outer wall of the column, 22 is an inner wall made of Teflon, 23 is a catalyst filling tank, and 24 is a waveguide. A flow hole is formed. The waveguide 24 is not filled with a catalyst. The catalyst catalyst tank 23 is partitioned by a spiral partition plate 26.

  The microwave irradiated to the catalyst column from the direction of the arrow is directly irradiated to the upper surface of the catalyst filled in the catalyst filling tank, and also to the side surface of the catalyst layer through the waveguide 24 and the inner wall 22. become. Thereby, the irradiation area of a microwave can be increased and the output microwave can be efficiently applied to a catalyst. Further, in this embodiment, since the catalyst layer is formed in a spiral shape, the contact time between the solution flowing through the catalyst layer and the catalyst can be maintained for a long time, thereby achieving the effect of promoting the room temperature decomposition reaction. .

  In the example of FIG. 2, at least the inner wall 22 only needs to be formed of a heat-resistant material that transmits microwaves. Therefore, the bottom surface provided with the outer wall 21, the partition plate 26, and the flow holes is heat-resistant to transmit microwaves. It may be formed of a heat-resistant material, or may be formed of a heat-resistant material such as metal (preferably a material such as true casting, copper, or bronze having excellent corrosion resistance) or stainless steel.

(Example 3)
FIG. 3 is an external view showing a schematic configuration of a catalyst column for microwave reaction according to Example 3 of the present invention. In this example, in the catalyst non-packing space formed by partitioning the inside of the catalyst column with a partition plate. A waveguide is formed. In the figure, 30 is a catalyst column, 31 is an outer wall of the column, 37 is a partition plate made of Teflon (four in the illustrated example), 33 is a catalyst filling tank, and 34 is a waveguide. The waveguide 34 is not filled with a catalyst. A large number of flow holes (not shown) for discharging the flow solution are formed on the bottom surface of the catalyst column.

  The microwave irradiated to the catalyst column from the direction of the arrow is directly irradiated to the upper surface of the catalyst filled in the catalyst filling tank 33 and also to the side surface of the catalyst layer through the waveguide 34 and the partition plate 37. The Thereby, the irradiation area of a microwave can be increased and the output microwave can be efficiently applied to a catalyst.

  Moreover, in the example of FIG. 3, since at least the partition plate 37 should just be formed with the heat resistant material which permeate | transmits a microwave, the bottom face which provided the outer wall 31 and the flow hole is a heat resistant material which permeate | transmits a microwave. It may be formed, or may be made of a heat-resistant material such as metal (preferably a material such as brass, copper, or bronze having excellent corrosion resistance) or stainless steel.

Example 4
FIG. 4 is a side view showing a schematic configuration of a catalyst column for microwave reaction according to Example 4 of the present invention. In this embodiment, the waveguide is formed in the center of the catalyst column. However, a catalyst-packed tank is provided along the outer peripheral surface of the catalyst column, the center is defined as a catalyst-unfilled space, and the catalyst-unfilled space is the waveguide. Use as

  In the figure, 40 is a catalyst column (square), 41 is an outer wall of the column, 43a is a catalyst filling tank made of Teflon plate (42 is an inner wall of the column), 44 is a waveguide, 45 is an eye formed by a SUS mesh filter or the like. A flow hole for discharging a flow liquid provided in a large number on the plate, 46 is a Teflon plate having a large number of holes. The waveguide is not filled with a catalyst. In this embodiment, the column 40 is fixed to the structure 49 to which the microwave oscillator 1 is attached, and the liquid to be processed (actual oil) is introduced from the supply port 48 provided in the structure 49.

  The catalyst filling tank is separately provided on the entire bottom surface (43b) of the column below the Teflon plate 46 and the entire peripheral surface (43a) of the column above the Teflon plate. The catalyst filling tank 43b can be formed by filling a catalyst on a mesh sheet or the like installed on the countersink plate, and contains 60% to 70% of the total catalyst amount in the catalyst filling tank.

  The liquid to be treated that has entered the column is introduced into the catalyst filling tank 43a through the pipe 47, overflows from the upper part of the catalyst filling tank, and then reaches the catalyst filling tank 43b through the Teflon plate 46. After flowing through the catalyst filling tank, it is discharged from the flow hole 45. The microwave irradiated into the catalyst column is irradiated to the two-layer catalyst filled in the catalyst filling tank through the waveguide 44, the Teflon plate inner wall 42, and the Teflon plate 46. Therefore, by providing the catalyst filling tank 43a, the ratio of the catalyst filled in the catalyst filling tank 43b is reduced and the catalyst layer is thinned, so that the microwave can reach the back of the catalyst layer. Furthermore, the catalyst filled in the catalyst filling tank 43a can be uniformly irradiated with microwaves. Thereby, compared with the case where a waveguide is not provided, the microwave irradiation area can be increased, the output microwave can be efficiently applied to the catalyst layer, and the catalyst of the liquid to be treated flowing through the catalyst layer The contact time with can be kept long.

  In the example of FIG. 4, the outer wall 41, the piping 47, and the bottom surface provided with the flow holes may be formed of a heat-resistant material that transmits microwaves, or metal (true cast, copper, A material such as bronze is preferable) or a heat resistant material such as stainless steel may be used.

(Example 5)
FIG. 5 is a side view showing a schematic configuration of a catalyst column for microwave reaction according to Example 5 of the present invention. In this embodiment, the waveguide is formed in the center of the catalyst column. However, two catalyst-packed tanks are provided along the outer peripheral surface of the catalyst column, and the center is used as a catalyst-unfilled space. Used as a waveguide.

  In the figure, 50 is a catalyst column (cylindrical), 51 is an outer wall of the column, 53a and 53b are catalyst filling tanks made of Teflon plates (52 is an inner wall, and a flow hole is formed in the bottom), 54 is a waveguide 55 is a circulation hole for discharging a circulation liquid provided in large numbers on a countersink plate formed of a SUS mesh filter or the like, and 56 is a Teflon plate having a large number of holes. The waveguide 54 is not filled with a catalyst. The catalyst filling tank is provided separately on the entire bottom surface (53c) of the column below the Teflon plate and the peripheral surfaces (53a and 53b) of the column above the Teflon plate. The catalyst filling tank 53c can be filled from a gap formed by appropriately moving a six-piece Teflon plate, and 60% to 70% of the total catalyst amount is accommodated in the catalyst filling tank. In the present embodiment, the column 50 is fixed to the structure 59 to which the microwave oscillator 1 is attached, and the liquid to be treated (actual oil) is introduced from the supply port 58 provided in the structure 59.

  The liquid to be treated that has entered the column is introduced into the catalyst filling tank 53a through the pipe 57, overflows from the upper part of the catalyst filling tank, and then introduced into the catalyst filling tank 53b. After overflowing from the catalyst, it reaches the catalyst filling tank 53 c through the Teflon plate 56, flows through the catalyst filling tank, and is discharged from the circulation hole 55. The microwave irradiated into the catalyst column is irradiated to the catalyst filled in the catalyst filling tank through the waveguide 54, the Teflon plate inner wall 52 and the Teflon plate 56. Therefore, by providing the catalyst filling tanks 53a and 53b in two stages, the ratio of the catalyst filled in the catalyst filling tank 53c is reduced and the catalyst layer becomes thin, so that the microwave can reach the back of the filling tank. Furthermore, the catalyst filled in the catalyst filling tanks 53a and 53b can be uniformly irradiated with microwaves. Thereby, compared with the case where a waveguide is not provided, the microwave irradiation area can be increased, the output microwave can be efficiently applied to the irradiated object, and the catalyst layer is formed in three layers. Therefore, the contact time between the liquid to be treated and the catalyst flowing through the catalyst layer can be kept long.

  In the example of FIG. 5, the outer wall 51, the portions other than the inner walls of the catalyst filling tanks 53 a and 53 b, and the bottom surface provided with the flow holes may be formed of a heat-resistant material that transmits microwaves, or metal ( (Materials such as brass, copper and bronze, which are excellent in corrosion resistance, are preferable) or a heat-resistant material such as stainless steel.

(Example 6)
FIG. 6 shows a schematic configuration of a catalyst column for microwave reaction according to Example 6 of the present invention. In this embodiment, the waveguide is formed in the center of the catalyst column. However, a catalyst-packed tank is provided along the outer peripheral surface of the catalyst column, the center is defined as a catalyst-unfilled space, and the catalyst-unfilled space is the waveguide. Use as

  In the figure, 60 is a catalyst column (square), 61 is an outer wall of the column, 62 is an inner wall made of Teflon, 63a and 63b are catalyst filling tanks for installing a catalyst filled in a mesh bag, and 64 is a waveguide. 65 is a circulation hole for discharging circulation fluid provided on a number of plate plates made of SUS mesh filter or the like, and 66 is a Teflon plate having a large number of holes. The waveguide 64 is not filled with a catalyst. The catalyst filling tank is provided continuously on the top plate (63b) on the bottom surface of the column and the circumferential surface (63a) of the column, and accommodates 50 to 60% of the total catalyst amount in 63b. In this embodiment, the column 60 is fixed to the structure 69 to which the microwave oscillator 1 is attached, and the liquid to be treated (actual oil) is introduced from the supply port 68 provided on the outer wall of the column.

  The liquid to be treated that has entered the column is first introduced into the catalyst filling tank 63a, then flows through the catalyst filling tank 63b, and is then discharged from the circulation hole 65 provided in the bottom surface. The oil is discharged from an outlet designed at the level of the oil level at the bed inlet. The microwave irradiated into the catalyst column is irradiated to the catalyst filled in the catalyst filling tank through the waveguide 64, the Teflon plate inner wall 62, and the Teflon plate 66. Therefore, by providing the catalyst filling tank 63 on the bottom surface and the peripheral surface, the catalyst layer can be formed thin, microwaves can reach the back of the catalyst layer, and the catalyst can be uniformly irradiated with microwaves. Can do. Thereby, compared with the case where a waveguide is not provided, the microwave irradiation area can be increased, the output microwave can be efficiently applied to the irradiated object, and the catalyst layer is formed on the bottom surface and the peripheral surface. Since it is formed, the contact time between the liquid to be treated flowing through the catalyst layer and the catalyst can be kept long.

  In the example of FIG. 6, the bottom surface provided with the outer wall 61 and the flow hole may be formed of a heat-resistant material that transmits microwaves, or metal (such as brass, copper, or bronze having excellent corrosion resistance). It may be made of a heat-resistant material such as stainless steel.

(Example 7)
FIG. 7 shows a schematic configuration of a catalyst column for microwave reaction according to Example 7 of the present invention. FIG. 7 (a) is a sectional view and FIG. 7 (b) is a plan view. In this embodiment, the waveguide is formed in the central part of the catalyst column. However, eight catalyst-packed tanks are provided along the outer peripheral surface of the catalyst column, and the central part is used as a catalyst-unfilled space. Used as a waveguide.

  In the figure, 70 is a catalyst column (square), 71 is an outer wall of the column, 72 is a partition plate made of Teflon having a large number of holes (a size that does not allow catalyst particles to pass through), and 73a to 73h are catalyst filling tanks (No. 1). 1 tank-8th tank) and 76 are lids. Reference numeral 74 denotes a waveguide, and the waveguide is not filled with a catalyst. In the catalyst filling tank, eight independent tanks are formed by Teflon partition plates 72 along the circumferential surface of the column. In this embodiment, the column 70 is fixed to the structure 79 to which the microwave oscillator 1 is attached, and the liquid to be treated (actual oil) is introduced from the supply port 77 provided on the side surface of the first tank. .

  The liquid to be processed that has entered the column is introduced into the first tank (73a) of the catalyst filling tank, circulates in the catalyst filling tank, and is provided on the partition plate in the second tank (73b) of the adjacent catalyst tank. Circulates through the holes. The liquid to be treated after the circulation sequentially passed through the third tank (73c) to the seventh tank (73g), and was also provided at a lower place than the inlet 77 provided in the eighth tank (73h). It is discharged from the outlet 78. The microwaves irradiated into the catalyst column are irradiated to the catalyst filled in the catalyst filling tanks 73a to 73h via the waveguide 74 and the Teflon partition plate 72. Therefore, by providing the catalyst filling tank 73 on the side surface, the catalyst layer can be formed thin, microwaves can reach the back of the catalyst layer, and the catalyst can be uniformly irradiated with microwaves. Thereby, the microwave irradiation area can be increased and the output microwave can be efficiently applied to the catalyst layer. In this embodiment, the catalyst layer is formed on the entire circumferential surface, and in the second, fifth and seventh tanks, the catalyst layer is formed in two layers via a partition plate, and the second, fourth and sixth tanks. In addition, since the catalyst can be filled, the catalyst layer can be uniformly irradiated with microwaves. The eighth tank may be filled with a catalyst, or a filter is not necessary if it is used as a trap tank for fine catalyst waste without being filled with a catalyst.

  In the example of FIG. 7, the bottom surface provided with the outer wall 71 and the flow hole may be formed of a heat-resistant material that transmits microwaves, or metal (such as brass, copper, bronze, etc. excellent in corrosion resistance). It may be made of a heat-resistant material such as stainless steel.

(Example 8)
Next, a decomposition method for decomposing an organic halogen compound using the microwave reaction catalyst column according to the present invention will be described.

  When the decomposition treatment is performed using the catalyst column of the present invention, the catalyst filling tank provided in the catalyst column is filled with the catalyst, the liquid to be treated containing the organic halogen compound is circulated in the catalyst filling tank, and the waveguide Microwave is irradiated from above to decompose the organic halogen compound. As a liquid to be treated containing an organic halogen compound, various solutions which are used for decomposition of an organic halogen compound and contain at least one hydrogen donor, an alkali compound, or a solvent can be used. A mixed solution containing a compound, a hydrogen donor and an alkali compound is preferred. This is because by causing such a mixture to flow, the hard-to-decompose PCB can be decomposed in a short time. The organic halogen compound may be a high-concentration product or a low-concentration product that is contained in a trace amount or a small amount in oil (mineral oil, electrical insulating oil, heat medium oil, lubricating oil), etc. Examples of the organic halogen compound include PCBs and dioxins. Hereinafter, the PCB disassembly process will be described as an example.

  In the case of carrying out the decomposition treatment, a mixed solution is prepared by adding isopropyl alcohol as a hydrogen donor to an insulating oil ratio of about 20% and KOH as an alkaline substance to an insulating oil ratio of about 1%. Separately, a catalyst column is prepared and filled with 5% Pd-supported activated carbon as a catalyst to form a catalyst medium layer. Next, the prepared mixed liquid is introduced into the catalyst layer prepared in the catalyst column, and after the catalyst layer is circulated, it is discharged through the circulation holes. At this time, when the microwave is irradiated from above the catalyst layer, the mixed liquid flowing through the catalyst layer comes into contact with the catalyst heated by the irradiated microwave, so that the organic halogen compound is more rapidly formed than in the case of non-heating. Decompose.

  The decomposition treatment may be performed until the organohalogen compound has a predetermined concentration or less, and therefore microwave irradiation may be performed as necessary, and the number, timing, and irradiation time are not limited. The output, frequency, and irradiation method of the microwave to be irradiated are not particularly limited and may be electrically controlled so that the reaction temperature can be maintained within a predetermined range. However, if the output is too low, the decomposition efficiency decreases. However, when the output is too high, the utilization factor of the microwave is deteriorated. Therefore, it is preferable to set the range of 10 W to 20 kW while electrically controlling. The microwave frequency is preferably 1 to 300 GHz, and in the frequency range of less than 1 GHz or more than 300 GHz, heating of the catalyst and the hydrogen donor becomes insufficient. 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 decomposition reaction is preferably performed in an inert gas because undesirable side reactions do not occur, but the reaction can also be performed in a natural atmosphere.

  The reaction temperature of the catalyst layer is preferably maintained at 200 ° C. or lower, more preferably 100 ° C. or lower, and particularly preferably 15 to 80 ° C. When the reaction temperature is 15 ° C. or higher, the decomposition reaction proceeds. On the other hand, when the reaction temperature exceeds 200 ° C., by-products are likely to be generated, resulting in poor economic efficiency.

  The catalyst is not particularly limited as long as it is a decomposition catalyst for an organic halogen compound, but a catalyst that can promote the dehalogenation reaction of PCB, has a long catalyst life, and is stable even in the presence of an alkali compound is preferable. Specifically, composite metal oxides, carbon crystal compounds, metal-supported carbon compounds, metal-supported oxides, metal-supported composite metal oxides, metal oxides, and the like are preferable. Carbon crystal compounds, metal-supported carbon compounds, metal-supported oxides and metal-supported composite oxides are preferred. In particular, a metal-supported carbon compound having high microwave absorbability is preferable. These catalysts can be used individually or in combination of 2 or more types. These regenerated catalysts may be used.

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

The metal-supported carbon compound, the metal-supported oxide, and the metal-supported composite oxide are not limited as long as the metal-supported carbon compound or the like is used, but the amount of the metal supported is 0.1 to 20 wt with respect to the total amount of the catalyst. %, More preferably 0.1 to 10 wt%. Examples of the supported metal include iron, silver, platinum, ruthenium, palladium, and rhodium, 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). 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 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. The catalyst particles should have the same particle size as possible.

  Examples of the hydrogen donor include organic hydrogen donors such as heterocyclic compounds, amine compounds, alcohol compounds, ketone compounds, and alicyclic compounds. From the viewpoint of safety, alcohols may be used. Alcohol compounds are particularly preferred from the viewpoints of safety, high availability and low cost, easy reaction control, and high PCB decomposition efficiency. These hydrogen donors may be used alone or in any combination of two or more. The alcohol compound may be either an aliphatic alcohol or an aromatic alcohol, but among these, 2-propanol and cyclohexanol are particularly preferable from the viewpoint of decomposition efficiency.

  The alkali compound is not limited 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, etc. Of these, caustic soda and caustic potash are particularly preferable from the viewpoints of cost and handling properties. You may use an alkali compound individually or in combination of 2 or more types.

  The hydrogen donor and the alkali compound may be pre-stirred in advance to prepare a solution in which the alkali compound is dissolved in the hydrogen donor, and this may be mixed with the organic halogen compound.

  The hydrogen donor is usually used in a volume ratio of 5 to 50% for oils containing a low concentration of organic halogen compounds and in a volume ratio of 50 to 1000 times for high concentrations of organic halogen compounds. In general, the alkali compound is preferably used in an amount of 1.0 to 1.5 times the equivalent of the organic halogen compound.

  According to the above decomposition treatment method, the organic halogen compound can be rapidly decomposed.

  The present invention has been described with reference to the embodiments. However, the above-described embodiments show one embodiment according to the present invention, and the present invention is not limited to the above-described embodiments. It goes without saying that various modifications are possible within the scope of the described invention, and these are also included within the scope of the present invention.

  The catalyst column for microwave reaction according to the present invention is used for various chemical reactions such as synthesis reactions (oxidation, reduction, rearrangement, polymerization), extraction, in addition to decomposition reactions of various compounds including organic halogen compounds. be able to. In addition, when the insulating oil containing PCB is decomposed using the decomposition processing method of the present invention, the oil after the decomposition treatment is recovered and can be reused as fuel, etc. Its practical value is great.

It is a schematic block diagram of the catalyst column for microwave reaction which concerns on Example 1 of this invention. It is a schematic block diagram of the catalyst column for the microwave reaction which concerns on Example 2 of this invention. It is a schematic block diagram of the catalyst column for the microwave reaction which concerns on Example 3 of this invention. It is a side view of the catalyst column for microwave reaction which concerns on Example 4 of this invention. It is a side view of the catalyst column for microwave reaction which concerns on Example 5 of this invention. It is a side view of the catalyst column for microwave reaction which concerns on Example 6 of this invention. It is sectional drawing (a) and the top view (b) of the catalyst column for microwave reaction which concern on Example 7 of this invention.

Explanation of symbols

1: Microwave oscillator 10, 20, 30, 40, 50, 60, 70: Catalyst column 11, 21, 31, 41, 51, 61, 71: Column outer wall 12, 22, 42, 52, 62: Column inner wall 13 23, 33, 43, 53, 63, 73: Catalyst filling tanks 14, 24, 34, 44, 54, 64, 74: Waveguides 45, 55, 65, 75: Flow holes 46, 56, 66: Holes Open Teflon plates 26, 37, 72: Partition plates (Teflon plates)
48, 58, 68, 77: supply port

Claims (7)

  A catalyst column for microwave reaction, wherein all or part of a contact surface with a catalyst is made of a microwave-permeable heat-resistant material and a waveguide is formed.   The catalyst column for microwave reaction according to claim 1, wherein a waveguide is formed in a central portion of the catalyst column.   The catalyst column for microwave reaction according to claim 1 or 2, wherein a catalyst-packed tank is provided along the outer peripheral surface of the catalyst column, the central portion is a catalyst-unfilled space, and the catalyst-unfilled space is used as a waveguide. .   The catalyst column for microwave reaction according to claim 1, wherein a waveguide is formed in a catalyst non-filling space formed by partitioning the inside of the catalyst column with a partition plate.   The catalyst column for microwave reaction according to any one of claims 1 to 4, wherein the microwave reaction is a decomposition reaction of an organic halogen compound.   A catalyst layer is formed in the catalyst column according to any one of claims 1 to 5, and a liquid to be treated containing an organic halogen compound is circulated in the catalyst layer, and microwaves are irradiated from above the waveguide, A decomposition method comprising decomposing an organic halogen compound.   The decomposition treatment method according to claim 6, wherein the liquid to be treated is a mixed liquid containing an organic halogen compound, a hydrogen donor, and an alkali compound, and the organic halogen compound is polychlorinated biphenyl.

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