JP2005246138A - Microwave reaction treatment apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a microwave reaction treatment apparatus, allowing large-volume treatment, high-level homogenization treatment and realization of high efficiency and achieving low costs and safety of operation at the same time. <P>SOLUTION: The apparatus decomposes gaseous substances by irradiating the substances with microwaves while causing the substances to be in contact with the inside or surface of a dielectric and using the dielectric as a surface waveguide for microwaves, and the decomposition treatment is carried out while mist of water molecules and film of water vapor are formed on the surface of the dielectric. The apparatus thereby permits large-volume treatment owing to uniform microwave excitation in the treatment region or the interface and the large area of the treatment reaction unit. The configuration of the apparatus permits efficient catalytic reaction in reaction treatment and treatment at low costs. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention uses a microwave band characterized in that the material to be treated is subjected to an electromagnetic wave treatment reaction by microwave excitation in heating, chemical decomposition, chemical synthesis, catalytic reaction, deodorization treatment, etc. of the microwave reaction treatment apparatus. The present invention relates to a high-frequency reaction processing apparatus.

  The reaction process using microwaves is mainly used for the heating reaction in the fields of drying and sintering because it can be heated by the material dielectric constant without being limited by the shape of the object to be heated. This is because the microwave is an electromagnetic wave and is caused by a friction phenomenon due to rotational energy caused by rotating polar molecules, and energy is input by utilizing a resonance phenomenon of high-frequency electromagnetic waves in the processing unit.

  In this way, since microwaves can directly excite molecules and selectively excite them depending on the polar state of the molecules, they can be used for decomposition, synthesis, catalysis, etc.

Among these treatments, the conventional decomposition treatment using microwaves is one in which decomposition reaction treatment is performed by thermal decomposition by heating reaction in or near the microwave absorber using microwaves as a heat source, and by thermal equilibrium plasma by microwaves Proposals have been made of those that perform a decomposition reaction, those that perform a decomposition reaction process using reduced-pressure non-equilibrium plasma, or those that perform a reaction on a dielectric surface by adding hydrogen gas (for example, Patent Document 1).
Japanese Patent Laid-Open No. 9-312285

  In the pyrolysis method using a microwave as a heat source, first, a material having a limited dielectric constant must be used in order to control the reaction in the heat absorber. Secondly, since it is necessary to soak heat at the heat absorber, uniform irradiation with microwaves is necessary, which makes it difficult to increase the size of the processing area for increasing the processing capacity, and restricts the apparatus structure.

  In the decomposition method using thermal equilibrium plasma using microwaves, the decomposition is performed by irradiating microwaves into a water vapor atmosphere containing the gas to be treated. However, microwaves are absorbed in the surrounding area in the water vapor atmosphere. Therefore, the reaction itself is not promoted in the processing internal region, which causes a problem in processing capacity and efficiency.

  The decomposition treatment method using the reduced-pressure non-equilibrium plasma using microwaves is not a practical method because it requires processing in a reduced-pressure atmosphere and lowers the processing density, making it difficult to reduce the cost and mass processing. In addition, there has been proposed a method in which hydrogen gas is introduced into a processing atmosphere and decomposition is performed by a gas-solid catalytic reaction.

  The problems to be solved by the present invention are as follows. (1) A device capable of uniformly and uniformly irradiating microwaves at a processing region or interface, and (2) a device capable of large-capacity processing capable of developing a microwave irradiation region over a large area, and (3) It is a device that can perform catalytic reaction efficiently in the reaction process, and (4) it can be processed in a compact and normal pressure for cost reduction, and (5) water vapor as a hydrogen supply source for the reaction It is to provide a processing device that can be used.

  The present invention relates to a reaction processing apparatus using microwave high frequency in heating, chemical decomposition, chemical synthesis, catalytic reaction, etc., among microwave reaction processing apparatuses.

  The object of the present invention is to solve the problems of the prior art as described above, and to achieve a high volume processing, high uniform processing, high efficiency, low cost and safe use at the same time. Is to provide.

  In order to achieve the object of the present invention, as a microwave irradiation structure, a microwave high-frequency electric field surface can be formed uniformly and uniformly with respect to the reaction processing region, and the loss is small with respect to the high-frequency power introduced and the load is highly efficient. In addition to reducing the size of the equipment to the maximum, there are few parts related to equipment maintenance for processing, and when increasing the microwave power for large-capacity processing. There is a need for a structure in which a plurality of oscillation sources can be introduced into the same load.

  At the same time, it must be a part to be irradiated with microwaves, and in the reaction processing region, it must be a reaction processing part in which a microwave-excited surface reaction can be performed on the entire reaction contact surface while allowing a process gas to pass easily while taking a large reaction contact surface. . Furthermore, the reaction interface of the processing gas must be able to contact the microwave irradiation interface efficiently and reliably.

In addition, when a reaction gas is introduced into the processing gas in the reaction and the processing reaction is performed, the processing gas and the reactive gas must be in contact with each other safely and reliably in the processing reaction section.
In order to embody the content, the following method is used.

  A cylindrical or spherical dielectric surface line made of a dielectric material, which is described in PCT / JPO3 / 05662 internationally filed by the present applicant as a microwave irradiation device structure, is configured, and the dielectric line is equivalent to an infinite line In order to make an infinite length dielectric line in which a high frequency coupling portion is provided on a cylindrical side surface or a spherical side surface so that a high frequency propagation line returns in a loop shape, an integer of a quarter wavelength of a high frequency introduced at least. In addition, a portion other than the high-frequency coupling portion outside the container, which is the infinite length dielectric line, is covered with a conductor so as to be an introduction high-frequency ground potential, and a high frequency introduced from the boundary surface between the conductor surface and the infinite length dielectric line A processing container having at least a part of the surface at a distance of a quarter wavelength length of the wavelength was configured, and an apparatus having a conductive surface inside the processing container was used as needed. Using microwave irradiation method.

  At the same time, in order to perform the microwave-excited surface reaction in the treatment contact reaction portion, a method is used in which a treatment portion having a large reaction contact area can be formed by using an inorganic dielectric porous material that can pass a treatment gas and can propagate through the microwave skin. At the same time, gas adsorption and microwave excitation absorption are performed in order to increase the contact reaction efficiency at the solid / gas contact interface at the processing gas and inorganic dielectric porous material interface in the processing section and to ensure that all the processing gas passes through the reaction system. Therefore, a method of increasing the contact reaction efficiency by introducing a fine water molecule mist into the treatment reaction part is used.

By using the water molecule mist, the processing gas is adsorbed by the water molecule mist and introduced into the microwave treatment reaction part, as well as the effect of the general scrubber treatment. The water molecule mist and the treatment gas are efficiently adsorbed on the body surface, and the microwave excitation absorption is promoted by the water molecule mist having a high microwave absorption rate.
When water molecule mist is microwave-excited on the surface of the dielectric porous material, the hydrogen or OH group is supplied by the thermal equilibrium reaction at the gas / solid surface interface, thereby further enhancing the treatment effect depending on the treatment. .

  The microwave reaction processing apparatus according to the present invention is an apparatus capable of large-capacity processing capable of expanding a processing reaction portion in a large area with uniform and uniform microwave excitation at a processing region or interface, and efficiently performing contact reaction in the reaction processing. It is possible to provide a processing apparatus that can perform processing at low cost.

  Hereinafter, an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a cross-sectional view of a vertical center portion of a microwave reaction processing unit configuration according to the present invention. In FIG. 1, a processing gas or a mixed gas of a processing gas and a reactive gas is introduced from a processing gas introduction port “6” formed in the introduction side flange “7”. A metal tubular water molecule mist generating tube “17” is connected to the introduction side flange “7”.

  A water storage container “12” is installed inside the water molecule mist generating pipe section “17”, and a constant amount of water for generating water molecular mist is always introduced into the storage container “12” from the water injection line “15”. Overflowing from the line “16”, the liquid level is made constant. A water molecule mist generating section “13” using a piezoelectric element is installed at the bottom of the water storage container “12”. By this operation, a water molecule mist “14” is generated from the water storage container “12”. 2.45 GHz microwave from microwave oscillation magnetron “1” via TM coupling mode through microwave coupling portion “2” and cylindrical outer dielectric dielectric microwave propagation line portion “8” and metallic cylindrical resonator Introduced into the area consisting of “3”.

  The microwave propagates in an infinite length in the circumferential direction on the inner surface of the outer cylindrical dielectric microwave propagation line portion “8” and the inner surface of the metal cylindrical resonator “3”. The evanescent surface wave is formed inside by the propagation of the dielectric line, and the microwave having a multipoint peak in the inner circumferential direction of the inner tube processing tube “9” is propagated and absorbed by the inorganic dielectric porous material “10”. The

In the microwave irradiation apparatus of this configuration, the microwave introduced from the microwave oscillating magnetron “1” propagates through the infinite length line, so that the reflected wave from the load side does not return to the oscillation side. In addition, it is not necessary to install an isolator or a matching unit, so that the cost can be reduced. At the same time, a plurality of similar microwave oscillation sources can be connected to the same load, so that the structure can cope with high power.
The inorganic dielectric porous body “10” has a porous portion connected and allows gas to pass therethrough. Further, a catalyst or the like may be supported, and a plurality of different types of porous bodies may be installed.

  The component described above is a microwave processing unit, and a discharge side flange “5” having a processing gas discharge port “4” is connected to the processing unit, and a processing is performed on the discharge side flange “5”. It is connected to an external pipe that has a negative pressure capable of sucking gas from the section.

  When the apparatus is operated in the above-described configuration, the processing gas introduced from the processing gas introduction port “6” or the mixed gas of the processing gas and the reaction gas contacts the water molecule mist “14” inside the water molecule mist generating tube “17”. Then, a part passes through the porous surface of the inorganic dielectric porous body “10” in the inner cylinder processing tube “9” while adsorbing with water molecules while being adsorbed by contact. On the other hand, the microwave introduced from the microwave oscillating magnetron “1” propagates by the surface wave including the porous inner region of the inorganic dielectric porous material “10”, and the water molecule mist adsorbing and contacting the surface of the porous material. Exciting action on the mixed gas of gas and process gas.

Water molecules have a high microwave absorption rate, and surface excitation on the surface of the inorganic dielectric porous material is promoted. Furthermore, at the solid / gas / liquid mixed phase interface on the surface of the inorganic dielectric porous material, some of the water molecules are desorbed from hydrogen groups or hydroxyl groups by the movement of electrons due to electromagnetic wave excitation. A reaction can be formed at the interface.
In this embodiment, a mist generator using a piezoelectric element is used to form a water molecule mist. However, a method of forming fine water droplets using a pressure spray capable of forming fine water droplets or an ultrasonic nozzle can also be used. .

  Here, specific dimensions and capacities are shown. The microwave oscillation magnetron “1” is a magnetron for 2.45 GHz 200 W, and the microwave coupling portion “2” has an opening with a width of 70 mm and a height of 130 mm, and an aluminum cylindrical resonator “3” and an outer cylinder dielectric. It couple | bonds by TM11 mode in the side surface of the body microwave propagation line part "8". The cylindrical resonator “3” has a cylindrical structure with an outer diameter of 100φ, a thickness of 5 mm, and a length of 200 mm, and the outer cylindrical dielectric microwave propagation line portion “8” has an outer diameter of 85 mm and an inner diameter of 60 mm formed of mica films. It has a cylindrical structure with a length of 170 mm. The inner cylinder processing tube “9” is a quartz tube having an outer diameter of 52 mm, an inner diameter of 46 mm, and a length of 200 mm, and is sealed by an O-ring “11” so that the processing portion has a sealed structure corresponding to external pressure. The inorganic dielectric porous material “10” is made of SiC, has an average pore diameter of φ1 mm, an outer diameter of 45 mm and a length of 170 mm, and carries a platinum catalyst by 0.5% by weight. The discharge side flange “5” of φ100 thickness 20 mm made of aluminum has a φ23 mm process gas discharge port “4” that can be connected to the NW25 flange, and is further flanged so that it can be connected to external piping. .

  The water molecule mist generating tube section “17” is made of aluminum, φ90 mm thickness, 3 mm length, 100 mm, and the lower thickness is 15 mm, and the lower portion is fixedly connected to the cylindrical resonator “3” with bolts. . The water storage container “12” is a stainless steel container having a height of 60 mm, an outer diameter of 60 mm, an inner diameter of 54 mm and a bottom thickness of 3 mm, and the water injection line “15” and the drainage line “16” are composed of 1/4 inch stainless steel pipes. The water molecule mist generating tube portion “17” penetrates the seal. The water molecule mist generating part “13” is a mist generator by piezoelectric element vibration with a vaporization capacity of 90 mL / hour for consumption of AC 24 V, 1.2 A, and the structure part is made of stainless steel.

  An aluminum-made φ100-thick 20 mm-thick inlet side flange “7” has a φ23-mm process gas inlet “6” that can be connected to an NW25 flange, and is further flanged so that it can be connected to external piping. .

  Examples of processing efficiency in the present embodiment are as follows. Toluene gas was introduced from the introduction side flange “7” so as to pass through the inside of the apparatus as a processing gas, and a fixed amount was passed through the processing gas discharge port “4” with a flow rate of 150 ppm / min. .

  The processing microwave power is fixed at 100 watts, and the processing gas discharge port “4” is used with the toluene detector tube GASTEC No122 of the suction type concentration measurement every microwave processing time of 0 minutes, 1 minute and 5 minutes. The toluene concentration was measured, and the presence or absence of water mist contamination was measured.

  In the water mist treatment, the water molecule mist of 80 mL / hour was generated in the water molecule mist generating section “13”.

  In the case of no water mist treatment, the concentration of toluene after 150 minutes after treatment for 0 minutes was 88 ppm after 1 minute and 50 ppm after 5 minutes. The result was 2 ppm after 1 minute and 0 ppm after 5 minutes with respect to the toluene concentration of 150 ppm.

  In the present embodiment, SiC is used as the material of the inorganic dielectric porous material “10”. However, a dielectric material containing alumina, Si, or carbon may be used. It can also be used.

  The application fields of the present invention are fields such as synthesis treatment, decomposition treatment, reforming treatment, catalytic reaction treatment, deodorizing treatment, and the like. The present invention is not limited to the above-described embodiments and embodiments, and includes various modifications without departing from the spirit and scope of the claims.

It is a vertical center part sectional view of the microwave reaction treatment equipment in the example of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Microwave oscillation magnetron 2 ... Microwave coupling part 3 ... Cylindrical resonator 4 ... Process gas discharge port 5 ... Discharge side flange 6 ... Process gas introduction port 7 ... Introduction side flange 8 ... Outer cylinder dielectric microwave propagation line part DESCRIPTION OF SYMBOLS 9 ... Inner cylinder processing pipe 10 ... Inorganic dielectric porous body 11 ... O-ring 12 ... Water storage container 13 ... Water molecule mist generation part 14 ... Water molecule mist 15 ... Water injection line 16 ... Drain line 17 ... Water molecule mist generation pipe part

Claims (6)

  In an apparatus for performing decomposition by irradiating microwaves while using a dielectric substance as a microwave surface wave line while contacting a gaseous substance with the inside or surface of the dielectric, a water molecule mist or a water vapor film is applied to the surface of the dielectric. A microwave reaction processing apparatus, wherein the processing is performed while being formed.   The microwave reaction processing apparatus according to claim 1, wherein a partial pressure of water molecule mist or water vapor with respect to the processing gas is 10% or less.   The microwave introduction line to the processing unit for performing the processing is a surface wave dielectric line, and the line is closed so that the microwave propagation line is infinitely long in the microwave propagation line. The microwave reaction processing apparatus of 2nd term | claim.   3. The microwave reaction processing apparatus according to claim 1, wherein the processing substance to be processed is a volatile organic compound.   The microwave reaction processing apparatus according to claim 1 or 2, wherein the dielectric is a porous body. 6. The microwave reaction processing apparatus according to claim 5, wherein the microwave reaction processing apparatus is a porous body carrying a catalyst.

Images