JP7602785B2 - Chemical reaction apparatus and chemical reaction method - Google Patents

Description

The present invention relates to a chemical reaction device and a chemical reaction method.

Various methods for continuously producing chemical substances have been developed with the aim of improving productivity of chemical substances. For example, Patent Document 1 describes a method for producing inorganic materials using microwave synthesis, in which a mixed solution of precursors for synthesizing the inorganic material is produced, and then the mixed solution is continuously introduced into a tubular reactor while irradiating the reactor with microwaves to continuously produce the inorganic material.

JP 2002-186849 A

A known method for continuously producing chemical substances is to cause the desired chemical reaction in a reaction channel while circulating reaction raw materials through the reaction channel by a flow reaction. However, it is difficult to apply a flow reaction to chemical reactions of highly viscous fluids such as those used in zeolite synthesis, or fluids containing slurry. To circulate such fluids through the reaction channel, a pump with a large power is required. As a result, the pump is expensive because it is made of special materials and has a special structure, and special maintenance is also required. In particular, in high-pressure reactions carried out under conditions of increased pressure inside the reactor, the pressure adjustment section that continuously extracts the reaction products (chemical substances) while maintaining the pressure inside the reactor has room for improvement in terms of the occurrence of many problems such as blockage of the slurry.

The objective of the present invention is to provide a chemical reaction device and a chemical reaction method that can continuously carry out chemical reactions, even when the reaction raw material is a highly viscous fluid or a fluid containing a slurry, and that makes it possible to easily remove the chemical substances obtained by the chemical reaction from inside the reactor.

The above object of the present invention is achieved by the following means.
[1]
A reactor having a tubular structure;
a temperature control mechanism movably disposed along the reactor;
and a means for removing the chemicals obtained in the reactor.
A chemical reaction apparatus, comprising: a temperature control mechanism that moves along the reactor to continuously heat-treat the reaction raw materials placed in the reactor, thereby producing chemical substances in the reactor, and the chemical substances being removed by the removal means.
[2]
The chemical reaction device according to claim 1, wherein the reactor has a portion where the temperature control mechanism moves linearly.
[3]
A pressurizing means for pressurizing the inside of the reactor;
The chemical reaction apparatus according to claim 1 or 2, further comprising a pressure adjusting mechanism for creating a blocked or narrowed state at the outlet portion of the reactor.
[4]
The chemical reaction device according to any one of [1] to [3], wherein the temperature control mechanism is a non-contact heating device that uses electromagnetic wave irradiation.
[5]
The chemical reaction apparatus according to claim 4, wherein the non-contact heating device has a mechanism for concentrating electromagnetic energy within the reactor.
[6]
The chemical reaction apparatus according to [5], wherein the non-contact heating device includes a cavity resonator having an electromagnetic wave irradiation space for concentrating electromagnetic wave energy.
[7]
The chemical reaction device according to [6], wherein the cavity resonator forms a single-mode standing wave of a TM _mn0 mode (m is an integer of 0 or more, n is an integer of 1 or more) or a TE _m0p mode (m and p are integers of 1 or more) by irradiating an electromagnetic wave into the cavity resonator.

[8]
A raw material filling step of filling a reaction raw material into a reactor having a tubular structure;
a chemical reaction step in which a temperature control mechanism is moved along the reactor to continuously heat the reaction materials to cause a chemical reaction;
and a discharge step of discharging a chemical substance produced by the chemical reaction,
The chemical reaction method comprises sequentially repeating the raw material charging step, the chemical reaction step, and the discharge step.
[9]
The chemical reaction method according to [8], wherein the reaction raw material includes a fluid having a viscosity of 10 ⁻² Pa·s to 10 ⁴ Pa·s, or a slurry containing 1 mass % to 95 mass % of solid particles.
[10]
The chemical reaction method according to [8], further comprising a pressurizing step of pressurizing the reaction raw materials filled in the reactor between the raw material filling step and the chemical reaction step.
[11]
The chemical reaction method according to [10], wherein the outlet portion of the reactor is closed or narrowed when pressurizing the reaction raw materials, and the outlet portion of the reactor is open during the step of supplying the reaction raw materials and the step of discharging the chemical substances.
[12]
The chemical reaction method according to any one of [8] to [11], wherein the heating by the temperature control mechanism is non-contact heating by electromagnetic wave irradiation.
[13]
The chemical reaction method according to any one of [8] to [12], wherein electromagnetic wave energy is concentrated within the reactor by the electromagnetic wave irradiation.
[14]
The chemical reaction method according to [13], wherein the temperature control mechanism includes a cavity resonator, and electromagnetic energy is concentrated in the reactor by forming a standing wave in the cavity resonator.
[15]
The chemical reaction method according to [14], wherein the standing wave is a single-mode standing wave of TM _mn0 mode (m is an integer of 0 or more, n is an integer of 1 or more) or TE _m0p mode (m and p are integers of 1 or more).
[16]
The chemical reaction method according to any one of [8] to [15], wherein a gas or a liquid incompatible with the reaction raw materials and the reaction product is supplied into the reactor so as to be sandwiched between the unreacted reaction raw materials and the product after the reaction is completed in the chemical reaction.

The chemical reaction apparatus and chemical reaction method of the present invention make it possible to continuously carry out chemical reactions of the reaction raw materials, even in chemical reactions using highly viscous fluids or fluids containing slurry, by moving the temperature control mechanism along the reactor. Moreover, the chemical substances obtained by the chemical reaction in the reactor can be easily removed.

1 is a cross-sectional view showing a schematic diagram of a preferred embodiment of a chemical reaction device of the present invention. 1 is a cross-sectional view showing a schematic diagram of a preferred embodiment of the chemical reaction method of the present invention, and is a drawing showing a raw material charging step of the chemical reaction method. FIG. 1 is a cross-sectional view showing a schematic diagram of a preferred embodiment of the chemical reaction method of the present invention, and is a drawing showing a pressurization step of the chemical reaction method. 1 is a cross-sectional view showing a schematic diagram of a preferred embodiment of the chemical reaction method of the present invention, and is a diagram showing a chemical reaction step of the chemical reaction method. FIG. 1 is a cross-sectional view showing a schematic diagram of a preferred embodiment of the chemical reaction method of the present invention, and is a drawing showing a discharge step of the chemical reaction method. FIG. 2 is a cross-sectional view showing a schematic diagram of another preferred embodiment of the chemical reaction device of the present invention. FIG. 2 is an X-ray diffraction pattern diagram of the fly ash particles used as the raw material and the particles after microwave heating treatment, in which the vertical axis indicates Intensity (arb. unit) and the horizontal axis indicates 2Theta (2θ) (deg.). FIG. 2A is a scanning electron microscope image of fly ash particles used as a raw material, and FIG. 2B is a scanning electron microscope image of the particles after microwave heating treatment. 1 is a photograph, substituted for a drawing, showing a transmission electron microscope image of platinum nanoparticles having a particle diameter of 2 to 5 nm in a synthesized state. 1 is an X-ray diffraction pattern diagram showing a single phase of FAU (faujasite) type zeolite, in which the vertical axis indicates Intensity (arb. unit) and the horizontal axis indicates 2Theta (2θ) (deg.). 1A and 1B are photographs substituting for drawings showing transmission electron microscope images of crystal particles having a particle size of 10 to 30 nm, in which FIG. 1A shows an overall image of the crystal particle, and FIG. 1B shows an enlarged image of the crystal particle. This is a nitrogen adsorption isotherm showing the results of nitrogen adsorption measurements to investigate the pore characteristics of zeolite, in which the vertical axis indicates the adsorption amount (Va ( ^cm3 (STP: standard temperature and pressure)/g)) and the horizontal axis indicates the relative pressure P (adsorption equilibrium pressure)/Po (saturated vapor pressure). This is a diagram showing the results of an analysis of mesopore pore size distribution by the BJH (Barrett-Joyner-Halenda) method, where the vertical axis shows particle size distribution dVp/d (dp) and the horizontal axis shows pore diameter (nm). The particle size distribution indicates the ratio (relative particle amount (volume) with the total being 100%) of particles of what particle size are contained in the particle group to be measured.

A preferred embodiment of the present invention will be described below with reference to the drawings. The present invention is not limited to the following embodiment except as specified in the present invention. In addition, the form of the device shown in each drawing is a schematic diagram to facilitate understanding of the present invention, and the size and relative size relationship of each component may be changed for the convenience of explanation, and do not directly show the actual relationship. In addition, matters other than those specified in the present invention are not limited to the external shapes and forms shown in these drawings.

[Chemical reaction device]
As shown in FIG. 1, the chemical reaction device 1 includes a reactor 10 having a tubular structure (also called tubular). The reactor 10 preferably has a portion that transports the reaction raw material 30 linearly inside the tube. That is, it is preferable that the reactor 10 has a straight tube portion. The outer diameter cross section and the inner diameter cross section of the reactor 10 are not particularly limited, and can be, for example, circular. By having a straight tube portion, it becomes easier to move a cavity resonator 21, which will be described later, along the reactor 10.
A temperature control mechanism 20 that can move in the tube length direction is disposed in the straight tube portion of the reactor 10. The temperature control mechanism 20 has a mechanism for irradiating the reaction raw material 30 (which may be used synonymously with the object to be treated in this specification) in the reactor 10 with electromagnetic energy, and preferably has a mechanism for concentrating the electromagnetic energy. The temperature control mechanism 20 may be in any form as long as it has the ability to heat the reaction raw material 30 with electromagnetic waves. For example, it may be in a form in which an electromagnetic wave having a frequency of 1 kHz or more is generated and the reaction raw material 30 in the reactor 10 is heated by the electromagnetic wave. That is, the temperature control mechanism 20 is a non-contact heating device that uses electromagnetic wave irradiation. As the electromagnetic wave, it is preferable to use microwaves, and other examples include infrared rays, visible light, ultraviolet rays, etc. The temperature control mechanism 20 may be, for example, a cavity resonator 21 that has an electromagnetic wave irradiation space in which electromagnetic wave irradiation is performed and can form a standing wave of microwaves. Hereinafter, the temperature control mechanism 20 will be described as a cavity resonator 21.

The cavity resonator 21 has a form that allows the straight tube-shaped part of the reactor 10 to be moved. For example, the cavity resonator 21 is arranged to be movable so that the central axis Ct of the reactor 10 having a tube structure coincides with the central axis C of the cylindrical cavity resonator 21. The cavity resonator 21 can be moved in various forms. For example, the cavity resonator 21 can be installed on a movable part of a linear stage, or the cavity resonator 21 itself can be moved to which an electric motor is attached. In this way, the cavity resonator 21 can be moved from one end of the reactor 10 to the other end, so that continuous heating by microwave irradiation can be performed over the entire area of the reactor 10, and the chemical reaction of the reaction raw materials in the reactor 10 can be promoted accordingly.
Furthermore, although not shown, the chemical reaction device 1 has a microwave supplying means for supplying microwaves of a frequency capable of forming a standing wave in the cavity resonator 21. The microwave supplying means includes a microwave generator for outputting microwaves, and an antenna for supplying the output microwaves into the cavity resonator 21. The microwave generator is provided with a microwave oscillator for oscillating microwaves. Furthermore, the chemical reaction device 1 may be provided with a control unit for controlling the microwave oscillator, an attenuator for adjusting the attenuation level of the microwave, an amplifier for amplifying the microwave power, an isolator for absorbing reflected waves, a matching device for suppressing reflected waves, and the like (not shown).

The cavity resonator 21 forms a standing wave in the microwave irradiation space 21A therein. The standing wave is preferably a _single mode of the TM _mn0 mode (m is an integer of 0 or more, and n is an integer of 1 or more) or the TE m0p mode (m and p are integers of 1 or more).
For example, in the case of TM ₀₁₀ mode, the energy (electric field strength) of the standing wave formed in the cavity resonator 21 at the central axis C of the microwave irradiation space 21A is maximized. Alternatively, in the case of TM ₁₁₀ mode, the energy (magnetic field strength) of the standing wave formed in the cavity resonator 21 at the central axis C of the microwave irradiation space 21A is maximized. The standing wave energy is uniform in the direction of the central axis C. A tubular reactor 10 is disposed along the portion where this energy is maximized and uniform or in the vicinity thereof. The reaction raw material 30 is disposed in the reactor 10 (internal space 10A). Whether a standing wave with a maximum electric field strength or a standing wave with a maximum magnetic field strength is formed on the central axis C depends on the physical properties of the reaction raw material 30. When the reaction raw material 30 has a dielectric loss, it can be efficiently heated by using a standing wave with a maximum electric field strength. When the reaction raw material 30 has a magnetic loss, it can be efficiently heated by using a standing wave with a maximum magnetic field strength. When the reactant 30 has electrical conductivity, the use of a standing wave with a maximum magnetic field strength allows heating by Joule heat due to induced current. When the reactant 30 contains metal, discharge may occur in the portion with a large electric field strength, so it is desirable to place the reactant 30 in the standing wave portion with a minimum electric field strength. In this case, in the cylindrical cavity resonator 21 in which the _TM110 mode standing wave is generated, the magnetic field strength becomes maximum at the central axis C, and the magnetic field strength becomes uniform along the central axis C. On the other hand, the electric field distribution of the _TM110 mode standing wave in the cavity resonator 21 has an electric field strength of 0 at the position of the central axis C.

For this reason, it is preferable that the central axis Ct of the reactor 10 is arranged so as to coincide with the central axis C of the cavity resonator 21. The reaction raw material 30 is arranged in the internal space 10A of the reactor 10. The reaction raw material 30 being arranged means that the reaction raw material 30 is present in the internal space 10A, and includes a state in which the reaction raw material 30 is stationary in the reactor 10 and a state in which the reaction raw material 30 is flowing in the reactor 10. The reaction raw material 30 may fill the entire internal space 10A of the reactor 10, or may fill only a part of it.
In the above description, a configuration in which the reactor 10 is provided as a constituent member has been shown, but the reactor 10 may not be provided as a constituent member, and instead of the reaction raw material, a rod-shaped reaction raw material may be used, and the heating or cooling conditions of the temperature control mechanism 20 may be set according to the type of the reaction raw material. In the present invention, such a configuration is also included in the present invention, as the rod-shaped reaction raw material also serves as the reactor 10. In addition, the reactor 10 does not need to have a shape with a hole penetrating it, as long as the reaction raw material is not circulated through the tube, and it may have a shape with one end closed (for example, the shape of a test tube).

A rectangular cylindrical cavity resonator (hereinafter also referred to as a rectangular cavity resonator) with a rectangular cross section can also be used. In the case of a standing wave in a _TE101 mode in such a cavity resonator, the electric field strength is maximized at the position of the central axis C, and the electric field strength is uniform along the central axis C. Alternatively, in the case of a standing wave in a _TE102 mode, the electric field strength is 0 and the magnetic field strength is maximized at the position of the central axis C, and the electric field strength is 0 along the central axis C, and the magnetic field strength is uniform at the maximum value (not shown).
In addition, in the TE _m0p mode (m is an integer of 1 or more and p is an integer of 1 or more) of a rectangular cavity resonator, there are axes other than the central axis C where the electric field is maximized and axes where the magnetic field is maximized, and similar effects are expected for these axes. However, since it is more difficult to specify the position other than the central axis than the central axis C, it can be said that the present invention is more preferable to place the central axis of the reactor 10 at the central axis position. In a rectangular cavity resonator, a standing wave in which the position of the central axis and the position where the electric field is maximized coincide is a TE _m0p mode (m is an integer of 1 or more and p is an odd number of 1 or more). Also, a standing wave in which the position of the central axis C coincides with the position where the magnetic field is maximized is a TE _m0p mode (m is an integer of 1 or more and p is an even number of 2 or more).

Although not shown, it is preferable that an antenna capable of applying a high frequency wave is provided at the microwave supply port of the cavity resonator 21. The antenna can be connected to a microwave generator via a cable. Note that the connection form of the antenna is not important as long as it is electrically connected to the microwave generator.
Microwaves generated from a microwave generator can be supplied from an antenna into the cavity resonator 21. In the microwave generator, the microwave power can be adjusted by an amplifier (not shown), thereby making it possible to control the energy intensity distribution of the standing wave formed in the cavity resonator 12.
The standing wave may be a frequency at which a standing wave of the above-mentioned TM mode or TE mode is formed within the cavity resonator 21 .
Alternatively, a microwave supply port using a waveguide may be provided instead of an antenna. By arranging a rectangular tube-shaped or cylindrical waveguide capable of transmitting the frequency of the microwave to be supplied and a cavity resonator via an iris having an appropriate opening, microwave energy from a microwave oscillator can be introduced into the cavity resonator 21.
It should be noted that each of the above-mentioned forms describes an example of the microwave processing device 1 of the present invention, and the chemical reaction device 1 of the present invention is not limited to the above-mentioned forms except as specified in the present invention.

When microwave processing utilizing an electric field is performed, it is also preferable to use the TM _mn0 mode (m is 0 or an even number of 2 or more, n is an integer of 1 or more) or the TE _m0p mode (m is an integer of 1 or more, p is an odd number of 1 or more). In particular, the TM ₀₁₀ mode standing wave in the cylindrical cavity resonator 21 and the TE ₁₀₁ mode in a rectangular cavity resonator (not shown) have an electric field maximum at the central axis C, making it easy to determine the position where the object to be processed is placed.
The object to be treated is placed in a portion where the electric field strength is strong, corresponding to the electric field strength inside the cavity resonator 21. In particular, more efficient heating is possible if the object is placed in a region where the electric field strength formed inside the cavity resonator 21 is at its maximum. For example, if the object to be treated is a material with dielectric loss, it can be heated more efficiently by absorbing the electric field energy. However, if the object to be treated is electrically conductive, such as a metal or a material containing ions, a discharge phenomenon may occur due to the electric field. If discharge generation is inappropriate, microwave treatment using the magnetic field maximum shown in the next section is appropriate.

In addition, when performing microwave processing using a magnetic field, it is also preferable to use the TM _mn0 mode (m and n are integers of 1 or more) or the TE _m0p mode (m is an integer of 1 or more, and p is an even number of 2 or more). In particular, the TM ₁₁₀ mode standing wave in the cylindrical cavity resonator 21 and the TE ₁₀₂ mode in the rectangular cavity resonator have a magnetic field maximum at the central axis C, making it easy to determine the position where the object to be processed is placed.
The object to be processed is placed in a portion where the magnetic field strength is strong, corresponding to the magnetic field strength inside the cavity resonator. In particular, if the object is placed in an area where the magnetic field strength formed inside the cavity resonator is at its maximum, more efficient heating is possible. For example, if the reaction raw material is a magnetic material, it can be heated more efficiently by absorbing the magnetic field energy. If the reaction raw material is a material containing metal or ions and has electrical conductivity, it can be heated by Joule heat due to the current induced in the material by the magnetic field, allowing more efficient heating.

In the above-mentioned chemical reaction apparatus 1, microwaves are supplied from a microwave generator to a cavity resonator 21 in which a reaction raw material or a reactor 10 containing reaction raw materials is present, and the above-mentioned standing wave is formed within the cavity resonator 21. For example, by arranging the reactor 10 along the portion where the magnetic field strength of this standing wave is at a maximum, the reaction raw material 30 in the reactor 10 can be processed with high energy efficiency. In the above-mentioned chemical reaction apparatus 1, microwaves that form the standing wave are supplied into the microwave irradiation space 21A from a microwave supply port provided in the cavity resonator 21.

The frequency of the standing wave may be, for example, a frequency of 2.45 GHz band or a frequency of 915 MHz band, as long as a standing wave can be formed in the cavity resonator 2. When heating by an electric field is expected, it is preferable that a standing wave of TM _0n0 mode is formed, and it is preferable that standing waves of TM ₀₁₀ , TM ₀₂₀ , and TM ₀₃₀ modes are formed. Among them, it is more preferable that a standing wave of TM ₀₁₀ mode is formed in the cylindrical cavity resonator 21 because the peak of the electric field intensity is located on the central axis C. For the same reason, it is also preferable that a standing wave of TE ₁₀₁ mode is formed in the rectangular cavity resonator. When heating by a magnetic field is expected, it is preferable that a standing wave of TM _1n0 mode is formed, and it is more preferable that standing waves of TM ₁₁₀ , TM ₁₂₀ , and TM ₁₃₀ modes are formed. Among them, it is more preferable that a standing wave of _TM110 mode is formed in a cylindrical cavity resonator because the magnetic field strength peak is located on the central axis C. For the same reason, it is also preferable that a standing wave of _TM102 mode is formed in a rectangular cavity resonator.

In the chemical reaction device 1, the microwaves supplied from the microwave generator are supplied with an adjusted frequency. By adjusting the frequency, the magnetic field strength distribution of the standing wave formed in the cavity resonator 21 can be controlled to a desired distribution state. In addition, the strength of the standing wave can be adjusted by the output of the microwave power. In other words, it becomes possible to control the heating state of the reaction raw material 30.
Specifically, although not shown, it can be controlled by the following control unit. The control unit may be built in the microwave generator, or may be configured separately, for example. This control unit adjusts the frequency of the microwave generated from the microwave generator based on the frequency (resonant frequency) of the standing wave formed in the microwave irradiation space 21A of the cavity resonator 21. Then, the microwave oscillator oscillates a microwave of the adjusted frequency. In order to detect the frequency (resonant frequency) of the standing wave in the microwave irradiation space 21A, it is preferable that a detection unit is arranged in the cavity resonator 21. The detection unit may be any unit that measures the energy intensity inside the microwave irradiation space 21A and processes the signal to detect the frequency. The microwave generator can also adjust the microwave output based on the value of the temperature measuring device. As a method of this, the attenuation rate of an attenuator (not shown) installed between the microwave oscillator (not shown) and the microwave amplifier (not shown) can also be adjusted.

The configuration of the chemical reaction device 1 of the present invention will be described in detail below.
<Reactor>
The reactor 10 having a tubular structure is preferably in the form of a circular tube. For example, the inner diameter is preferably 1 to 20 mm, and the outer diameter is preferably 3 to 22 mm. The inner diameter is more preferably 1 to 10 mm, and the outer diameter is more preferably 3 to 12 mm. In the case of heating by microwaves, the reactor 10 is preferably made of a material that transmits microwaves, and examples of such materials include glass materials such as quartz, resin materials such as fluororesins, and ceramic materials such as alumina. The reactor 10 is preferably configured such that the reaction raw material is supplied from one end thereof and the reaction product is discharged from the other end thereof.
In one embodiment, both ends of the reactor 10 are open, and one end of the reactor 10 has a piston 11 as a removal means for discharging and removing chemical substances (reaction products) obtained by a chemical reaction from the other end. The piston 11 is arranged so as to be slidable within the reactor. In other words, the piston 11 is arranged so that the substance on the side being pushed by the piston 11 does not flow into the side being pushed. The piston 11 can also be used as a pressurizing means for pressurizing the inside of the reactor 10 to atmospheric pressure or higher, in addition to pressurization using a working fluid described later.

A reaction raw material supply unit (not shown) for supplying the reaction raw material 30 is connected to the side surface of the one end of the reactor 10 via, for example, a pipe (not shown) and a ball valve 12. In addition, it is preferable that a pump for feeding the reaction raw material is provided in the pipe. In the illustrated state, the ball valve 12 is in an open state. Therefore, the reaction raw material 30 is filled in the inside 10A of the reactor 10. By providing the ball valve 12 having a flow path equivalent to the inner diameter of the pipe, it becomes easy to start and stop the supply of the reaction raw material including a highly viscous reaction raw material or a slurry.
Furthermore, when the reaction solution as the reaction raw material has a high viscosity or is in a slurry state, the power load of the pump required for supplying the raw material solution can be reduced by using a ball valve 12 having a large inner diameter of the flow passage 12P.

A ball valve 13 is disposed at the other end of the reactor 10. In the illustrated state, the ball valve 13 is in a closed state. When closed, the ball valve 13 has the function of confining the reaction raw material 30 in the reactor 10. When open, the ball valve 13 functions as an outlet for discharging the reaction products (chemical substances) generated in the reactor 10 by driving the piston 11. For this reason, it is preferable that the flow path 13P of the ball valve 13 is equal to the inner diameter of the reactor 10. As such a valve form, a ball valve is preferable. In addition, since the ball valve 13 is used, the reaction products generated in the reactor 10 can be smoothly taken out of the reactor 10 without clogging the outlet. Furthermore, depending on the opening and closing state of the ball valve 13, it is possible to block or narrow the outlet portion of the reactor 10. This also makes it possible to adjust the pressure in the reactor 10. That is, the ball valve 13 also functions as a pressure regulating mechanism for adjusting the pressure in the reactor 10.

A working fluid supply unit (not shown) for supplying a working fluid (not shown) is connected to another side of the one end of the reactor 10 through a pipe (not shown), a boost pump 14 as a pressurizing means, and a pipe 15. In addition, it is preferable that a gate valve 16 is provided in the pipe 15. For example, the gate valve 16 may be configured as a ball valve as shown in the figure. In the illustrated state, the gate valve 16 is in a closed state. Therefore, the working fluid is not supplied to the inside 10A of the reactor 10. As described above, the working fluid is boosted by the boost pump 14 and supplied into the reactor 10, so that the reaction raw materials can be pressurized to a predetermined pressure equal to or higher than atmospheric pressure. Since only the working fluid flows through the boost pump 14 required for pressurizing the reaction raw materials, there is no need to use a special pump such as a slurry pump. For example, a pump for high performance liquid chromatography (HPLC) can be used. The working fluid can be water, an organic solvent, a fluorocarbon solvent, or the like, which is incompatible with the reaction raw materials. In addition, if it is acceptable to mix with the reaction raw materials, the working fluid does not have to be a liquid that is incompatible with the reaction raw materials. Also, a gas can be used.
In addition, since the pressurization by the working fluid from the boost pump 14 can push out the chemical substances (reaction products) produced in the reactor 10, it can also be used as an extraction means.

<Cavity resonator>
The shape of the cavity resonator 21 used in the chemical reaction device is not particularly limited as long as it has one or more microwave supply ports and forms a single-mode standing wave when microwaves are supplied. For example, a cylindrical or rectangular cavity resonator can be used. In this specification, a cylindrical cavity resonator is used to mean a cavity resonator whose inner cross-sectional shape perpendicular to the central axis C is circular, as well as a cavity whose cross-sectional shape is elliptical or oblong. A rectangular cavity resonator means a cavity whose inner cross-sectional shape perpendicular to the central axis C is polygonal, and the cross-sectional shape is preferably, for example, 4-10 sided. The corners of the polygon may be rounded.
The size of the cavity resonator 21 can be appropriately designed according to the purpose in the above-described embodiment. The length of the cavity resonator 21 in the direction of the central axis C is not particularly limited, but if it is too short, sufficient microwave power may not be supplied to the cavity resonator 21. In addition, when the wavelength of the supplied microwave is λ, if the length is λ or more, it is necessary to separate the resonance frequency at which a high-order standing wave with a maximum magnetic field distribution is formed in that direction from the resonance frequency of the target standing wave. For this reason, it is preferable that the dimension of the cavity resonator in the direction of the central axis C is λ or less. The value of λ varies depending on the resonance frequency, but for example, when the resonance frequency is 2.4 to 2.5 GHz, λ is preferably 125 to 120 mm, and when the resonance frequency is 900 to 930 MHz, λ is preferably 333 to 322 mm.
When there are two or more microwave supply ports, a time-averaged standing wave formed by controlling the phases of the microwaves may be used.
The cavity resonator 21 is preferably one having a low electrical resistivity and is usually made of a metal, such as aluminum, copper, iron, magnesium, brass, stainless steel, or an alloy thereof. Alternatively, the surface of a resin, ceramic, or metal may be coated with a substance having a low electrical resistivity by plating, vapor deposition, or the like. Materials containing silver, copper, gold, tin, or rhodium can be used for the coating.

<Microwave generator>
In the chemical reaction apparatus 1 of the present invention, microwaves generated by a microwave generator are supplied from a microwave supply port through an antenna into the microwave irradiation space 21A of the cavity resonator 21. As described above, the microwave generator includes a microwave oscillator, and may also include a control unit for controlling the microwave oscillator, and may further include an attenuator, an amplifier, an isolator, a matching device, etc. Alternatively, microwaves may be supplied into the microwave irradiation space 21A using a waveguide connected to the cavity resonator 21 through an iris.

<Microwave Oscillator>
The microwave oscillator included in the microwave generator may be a microwave oscillator capable of adjusting the oscillation frequency within the range of 2.45 GHz band. For example, a microwave oscillator using a semiconductor solid-state element or a microwave oscillator such as a magnetron may be used. From the viewpoint of finely adjusting the microwave frequency, it is preferable to use a microwave generator using a semiconductor solid-state element. As a microwave oscillator using a semiconductor solid-state element, for example, a microwave generator using a Gunn diode, an avalanche diode (Impatt diode), etc. may be used. Alternatively, in the MHz band, an oscillation circuit using an LC circuit consisting of a coil and a capacitor may also be used. In addition, a VCO (Voltage Controlled Oscillator) or a PLL (Phase Locked Loop) circuit in which these elements and a frequency control mechanism are packaged may also be used. The microwaves generated by the microwave oscillator are not limited to those in the 2.45 GHz band, and those generating microwaves in other frequency bands such as the 915 MHz band, 5.8 GHz band, etc. can also be used as appropriate.

<Attenuator>
The attenuator adjusts the attenuation level to adjust the temperature of the object to be treated and determines the final microwave power. The attenuator adjusts the inlet level of the microwave amplifier to adjust the final output. As a microwave adjustment method that does not use an attenuator, there is also a method of adjusting the amplification factor of the microwave amplifier.

<Control Unit>
The control unit controls the frequency of the microwaves supplied by the microwave supply means based on the change in the resonant frequency. This change in the resonant frequency is caused by a change in the dielectric constant of the reaction raw materials due to a change in at least one of the conditions of the reaction raw materials, such as the shape, composition, phase, and temperature. Since this change in dielectric constant can change the frequency at which the magnetic field becomes maximum, the position at which the magnetic field becomes maximum is controlled to a constant position.
In order to control the maximum position of the magnetic field to a fixed position, there is a method of adjusting the microwave generated by the microwave oscillator so that it matches the frequency of the standing wave formed in the microwave irradiation space 21A of the cavity resonator. Although it is preferable for the frequency to match completely, a difference within a certain range, for example within 1%, is also included in the category of frequency matching.
For example, the detection unit analyzes the detected signal to determine a frequency signal to be sent to the microwave oscillator. Then, microwaves with the same frequency are generated by the microwave oscillator and irradiated into the microwave irradiation space 21A.
The functions of the control unit are not limited to those described above, and the control unit can also control various functions of the microwave processing device.

A specific example of the control method in the control unit will be described. The detection unit detects an output signal proportional to the energy intensity of the microwave in the microwave irradiation space 21A. On the other hand, the microwaves supplied to the microwave irradiation space 21A are microwaves oscillated from a microwave oscillator or microwaves oscillated from a microwave oscillator and amplified by an amplifier. At this time, when the frequency generated from the microwave generator is swept over the entire 2.45 GHz band or a part of the 2.45 GHz band, for example, the output signal of the energy intensity from the detection unit has a distribution with a maximum value. This maximum value means that a standing wave has been formed in the microwave irradiation space 21A, so that the resonant frequency of a predetermined mode can be detected by comparing it in advance with the resonant frequency of the TM _mn0 (m is an integer of 0 or more, n is an integer of 1 or more) _mode or the TE m0n (m and n are integers of 1 or more). The control unit oscillates microwaves from the microwave oscillator so that the frequency of the microwaves generated from this microwave generator coincides with the frequency of the detected microwaves.

Alternatively, the control unit may not use the output signal from the detection unit, but may use a reflected wave signal from a reflected wave detector installed between the microwave generator and the cavity resonator 21. In this case, a small reflected wave, that is, the frequency of the reflected wave being a minimum value, means that energy is supplied to the cavity resonator 21 and a standing wave is formed. Therefore, the microwave resonator frequency can be derived from the minimum value of the reflected microwave wave.
In this way, a microwave having a frequency that matches the resonant frequency of the microwave derived from the maximum value detected by the detection unit or the minimum value detected by the reflected wave detector is oscillated from the microwave oscillator of the microwave generator, or a microwave having a frequency that matches the resonant frequency of the detected microwave is output from the amplifier.
Then, microwaves having a frequency that matches the resonant frequency are supplied into the microwave irradiation space 21A.

It is desirable to perform the operation for detecting the resonance frequency periodically. When there is a large disturbance or when there is a large change in state such as temperature, flow rate, or composition, it is desirable to perform the operation at a short interval, for example, at intervals of 1 second or less, immediately after the start of microwave treatment. On the other hand, when there is little disturbance or when there is little change in state such as temperature, flow rate, or composition, it may be performed at a long interval, for example, every minute, after a sufficient time has elapsed since the start of microwave treatment and it has stabilized.
When sweeping the frequency of the microwaves from the microwave generator to detect the resonant frequency, it is preferable to have a narrow sweep frequency range. However, if the fluctuation is large and the sweep frequency range is too narrow, it may not be possible to find a maximum value within the sweep frequency range. In that case, it is also preferable to widen the sweep frequency range and perform the sweep again to detect the resonant frequency.

<Microwave amplifier>
The microwave generator is preferably provided with an amplifier for amplifying the microwaves generated by the microwave oscillator. There is no particular limitation on the configuration of this microwave amplifier, but it is preferable for example to be configured as a high-frequency transistor circuit having a high-frequency field effect transistor (FET) in terms of miniaturization. The output power of the microwave amplifier can be set appropriately. As a means for adjusting the microwave power to be irradiated, an attenuator may be provided before the input stage of the microwave amplifier. Alternatively, a means for adjusting the amplification factor of the microwave amplifier may be used.

<Isolator>
An isolator protects a microwave amplifier by suppressing (e.g. absorbing) the effects of reflected waves generated by a microwave oscillator, and allows microwaves to be supplied in one direction (towards the antenna). A circulator can also be used instead of this isolator. When using a circulator, a termination resistor (dummy load) is connected to one of the three ports. The remaining two ports become the input and output. If the microwave amplifier, wiring, cables, and connectors are at a level where they will not be damaged by reflected waves, there is no need to provide an isolator or circulator.

<Matcher>
The matching box has a function of suppressing reflected waves so that no reflected waves are generated. As the matching box, a variable stub tuner, slug tuner, EH tuner, or the like can be used. In addition, if the microwave absorption characteristics of the object to be processed do not change significantly, a fixed matching box can also be used. In addition, a semi-fixed matching box can be used, which allows the matching box to be temporarily adjusted when the object to be processed is placed.
For example, a configuration can be adopted that includes a line formed of a microstrip line on a circuit board and a capacitor that adjusts the impedance (e.g., S parameter) of the line. Also, the line may be provided with a line pattern adjustment unit for adjusting the impedance of the line.
If the microwave amplifier, wiring, cables, connectors, etc. are not damaged by the reflected waves, there is no need to provide a matching device.

<Antenna>
A microwave supply port is provided on a wall surface (inner surface of the cylinder) parallel to the central axis C of the cylindrical cavity resonator 21 or in the vicinity thereof. It is preferable that an antenna capable of applying high frequency waves through the microwave supply port is disposed in the microwave irradiation space 21A. As the antenna, it is preferable to use a magnetic field excitation antenna, for example, a loop antenna, or an electric field excitation antenna, for example, a monopole antenna or a dipole antenna. The input end of the antenna is connected to the output end of the line of the matching device.
Alternatively, the microwave supply port can be formed by using a waveguide having an iris in the cavity resonator 21 .
Typically, microwaves generated from a microwave oscillator are passed through a microwave amplifier, an isolator, a matching box, and an antenna, and then supplied to the microwave irradiation space 21A.
When the antenna in the microwave processing space 21A is a loop antenna serving as a magnetic field excitation antenna, it is preferable that the end of the loop antenna is connected to a ground potential such as a wall of a cavity resonator. By applying microwaves (high frequency waves) to this antenna, for example, a magnetic field is excited in the loop of the loop antenna, forming a standing wave in the cavity resonator.
When the antenna in the microwave processing space 21A is an electric field excited monopole antenna or dipole antenna, it is preferable that the ends are not connected to the wall surfaces of the cavity resonator but are left open.

When the above antenna is configured as a loop antenna, it is preferable that the end face is connected to a ground potential such as a wall surface of a cavity resonator. By applying microwaves (high frequency waves) to the antenna, a magnetic field is excited within the loop of the loop antenna, and a standing wave can be formed within the cavity resonator 21.
For example, when a single mode standing wave of _TM110 is formed in the cylindrical cavity resonator 21, the magnetic field strength becomes maximum at the central axis C and uniform in the direction of the central axis C. Therefore, in the reactor 10, the raw material solution 30 present therein can be uniformly and highly efficiently microwave-heated.
Alternatively, microwaves may be supplied from a microwave generator to the microwave supply port using a waveguide.
Furthermore, in the above configuration, it is also preferable to arrange a microwave amplifier, an isolator, a matching device, an antenna, etc., in a housing integral with the cavity resonator 21 in order to reduce the size of the device.

<Reaction raw materials>
In the chemical reaction device 1 of the present invention, the reaction raw material (for example, the raw material solution placed in the reactor) is placed inside the cavity resonator 21 so as to correspond to the maximum point of the electric field of the standing wave or its vicinity, or the maximum point of the magnetic field or its vicinity. When the reaction raw material 11 has a dielectric loss, it is preferable to place it at the maximum point of the electric field or its vicinity, but when the dielectric loss is large, if the maximum length of the reactor 10 is large, a standing wave may not be formed. In this case, when the reaction raw material has a magnetic loss, has a conductivity, or contains an ionic solution, a reactor 10 having a large maximum length can be used by placing it at the maximum point of the magnetic field or its vicinity. In the case of a fluid with high viscosity or a fluid containing a slurry, the larger the maximum length of the reactor, the lower the pressure loss. For example, a fluid with a viscosity of 10 ^-2 Pa·s or more and 10 ⁴ Pa·s or less is preferable, a fluid with a viscosity of 1 Pa·s or more and 10 ³ Pa·s or less is more preferable, and a fluid with a viscosity of 10 Pa·s or more and 5×10 ² Pa·s or less is even more preferable. In addition, a fluid containing a slurry having a solid particle content of 0.1% by mass or more and 95% by mass or less is preferable, a fluid containing a slurry having a solid particle content of 1% by mass or more and 90% by mass or less is more preferable, and a fluid containing a slurry having a solid particle content of 5% by mass or more and 80% by mass or less is even more preferable.
For example, the reaction raw material used in zeolite synthesis is a highly viscous fluid called water glass, and the reaction product is a slurry containing solids. In this case, more efficient heating is possible by arranging the nozzle along the portion where the magnetic field strength of the standing wave formed in the cavity resonator 21 is maximized.
As another example, the reaction raw material used in the synthesis of metal nanoparticles contains a large amount of polymer protective agent, so it is a highly viscous fluid, and since the reaction raw material contains ionic molecules, it becomes difficult to form a standing wave if the maximum length of the reaction tube is increased. In order to increase productivity, it is desirable to use a high-concentration raw material, so it is necessary to handle a fluid with a higher viscosity and a large number of ions. If the nozzle is placed along the part where the magnetic field strength of the standing wave formed in the cavity resonator 21 is maximized, more efficient heating is possible.

In the chemical reaction apparatus 1 of the form shown in FIG. 1, there is no particular limitation on the reaction raw material 30 placed in the reactor 10, and examples include liquids, solids, powders, slurries, and mixtures thereof. The chemical reaction apparatus 1 of the present invention can also be suitably applied to those in which the reaction raw materials or reaction products cause precipitation.

[Chemical reaction method]
The chemical reaction method uses a chemical reaction apparatus 1 shown in FIG. 1. First, the reaction raw material 30 is filled into the portion of the reactor 10 with a tubular structure where the reaction raw material is to be processed (raw material filling step). Next, the reaction raw material 30 filled in the reactor 10 is kept stationary, and the temperature control device 20 (cavity resonator 21) is moved along the reactor 10, and the reaction raw material 30 is continuously heated or cooled to proceed with the chemical reaction (chemical reaction step). Next, the chemical reaction material generated by the chemical reaction is discharged (discharge step). Then, the raw material filling step, chemical reaction step, and discharge step are repeated in sequence. By repeating each step many times in this manner, it is essentially the same as flowing the reaction raw material from the ball valve 12 side of the reactor to the ball valve 13 side for processing. This processing method is also called a semi-flow type.
It is also preferable to have a pressurizing step of pressurizing the reaction raw materials 30 filled in the reactor 10 between the raw material filling step and the chemical reaction step.

A preferred embodiment of the chemical reaction method will be described in detail below.
In the chemical reaction method, as shown in Fig. 2, first, a raw material filling step is performed. In the raw material filling step, the reaction raw material 30 is supplied and filled into the inside of the reactor 10 by a pump (not shown) for feeding the reaction raw material while the ball valve 12 is opened and the ball valves 13 and 16 are closed. At this time, the inside of the reactor 10 is closed by the piston 11 on the opposite side of the ball valve 13.

Next, as shown in FIG. 3, it is preferable to carry out a pressurizing step. In the pressurizing step, with ball valves 12 and 13 closed and ball valve 16 open, a working fluid (e.g., water) is pumped into reactor 10 by boost pump 14, and the pressure of reaction raw material 30 in reactor 10 is increased to a predetermined pressure. It is preferable to check the pressurizing force using a pressure gauge. After the internal pressure of reactor 10 reaches the predetermined pressure, ball valve 16 is closed.

Next, as shown in Fig. 4, a chemical reaction process is performed. In the chemical reaction process, the cavity resonator 21 is moved from the ball valve 13 side to the piston 11 side along the reactor 10 in the direction of the arrow A while the ball valve 12, the ball valve 13, and the ball valve 16 are closed. During the movement, the cavity resonator 21 irradiates microwaves to heat the reaction raw material (reaction solution) 30 in the reactor 10 in the cavity resonator 21, thereby generating a reaction product (chemical substance) 32. That is, the reaction raw material 30 at the position to which the cavity resonator 21 has moved is heated. At this time, it is preferable to move the cavity resonator 21 so that the reaction raw material 30 in the reactor 10 has a necessary reaction time. The moving speed of the cavity resonator 21 for this purpose is preferably set so that the temperature at which the reaction raw material undergoes a chemical reaction is secured.
Alternatively, the cavity resonator 21 may be moved and stopped for a certain period of time repeatedly, thereby ensuring a sufficient heating time by microwave irradiation.
In this manner, by moving the cavity resonator 21, the reaction raw material 30 can be heated by irradiating microwaves over the entire length of the reactor 10, thereby accelerating the chemical reaction.

Then, when the reaction can proceed in the entire area of the reactor 10, the microwave irradiation by the cavity resonator 21 is stopped. Then, as shown in FIG. 5, the discharge step is performed. This discharge step is performed with the ball valves 12 and 16 closed and the ball valve 13 open. After performing the valve operation as described above, the piston 11 is driven and pushed into the reactor 10, thereby pushing out the reaction product 32 from the reactor 10. Alternatively, the boost pump 14 is operated (in this case, the ball valve 16 is opened) to push the working fluid or the like into the reactor 10, thereby discharging the reaction product 32, which is the product after the chemical reaction, from the reactor 10. At this time, if the inner diameter of the flow path 13P of the ball valve 13 is equal to the inner diameter of the reactor 10, the reaction product 32 can be discharged without a large power even if it is a slurry or a solid. Therefore, the trouble of clogging by the reaction product at the outlet of the reactor 10 is less likely to occur.
In the above chemical reaction, it is preferable to supply a gas such as air or a fluid incompatible with the reaction raw materials 30 and the reaction product 32 into the reactor 10 so as to be sandwiched between the unreacted reaction raw materials 30 and the reaction product 32 after the reaction is completed. Examples of the incompatible fluid include aqueous solvents, organic solvents, fluorocarbon solvents, gases, etc. This can prevent the working fluid from dissolving in the reaction raw materials.

When the reactant material in the reactor 10 is heated in the above-mentioned chemical reaction method, microwaves are irradiated into the cavity resonator to form a single mode standing wave of TM _mn0 mode (m is an integer of 0 or more, n is an integer of 1 or more) or TE _m0p mode (m and p are integers of 1 or more) in the cavity resonator. The reactant material 30 in the reactor 10 is heated using the standing wave. This heating is mainly a heat treatment, but also includes a treatment such as breaking molecular bonds by endothermic reaction. For example, microwaves with a frequency of 915 MHz or 2.45 GHz are used as the microwaves. This method includes arranging the reactant material 30 along a portion where the electric field strength or magnetic field strength of the standing wave is maximum, and heating the reactant material 30 to cause a chemical reaction.
In a chemical reaction method, the reaction involving the raw materials can be promoted or stopped by controlling the temperature of the raw materials. For example, the reaction can be promoted by increasing the temperature of the raw materials, and stopped by stopping heating and decreasing the temperature.

In the above chemical reaction method, the reactor 10 may be cooled to cool or freeze the reaction raw materials, thereby suppressing unnecessary diffusion of the reaction raw materials during heating. For example, as shown in FIG. 6, coolers 41 and 42 may be arranged around the reactor 10 to cool the inside of the reactor 10 with a refrigerant. Examples of the coolers 41 and 42 include refrigerant pipes through which a refrigerant circulates. The cooler 41 arranged on the side of the moving direction of the cavity resonator 21 lowers the temperature of the reaction raw materials 30 before microwave irradiation. For example, the reaction raw materials 30 may be frozen. The low-temperature or frozen reaction raw materials 30 can be heated by microwave irradiation to cause a chemical reaction. The cooler 42 arranged on the opposite side of the moving direction of the cavity resonator 21 quickly stops the chemical reaction caused by microwave heating by the cavity resonator 21. In addition, it is possible to prevent the diffusion of the reaction product 32. This makes it possible to more accurately control the chemical reaction time by microwave irradiation to a fixed time.
Alternatively, the entire reactor 10 including the cavity resonator 21 may be placed in an ice bath, for example, to perform microwave heating by the cavity resonator 21. In this case, the area other than the area heated by the cavity resonator 21 is cooled, so that the chemical reaction stops and the diffusion of the reaction product can be prevented. In this cooling, it is preferable to have a cooling speed faster than the moving speed of the cavity resonator 21.
As shown in FIG. 6, in the case of a horizontal reactor in which the reactor 10 is disposed horizontally, if the reaction product 32 has a higher specific gravity than the reaction raw material 30, the reaction product 32 will accumulate at the bottom of the reactor 10. However, this is not a problem because this is not a chemical reaction that causes the reaction raw material to flow.

Examples of the chemical reaction include rearrangement reaction, substitution reaction, addition reaction, cyclization reaction, condensation reaction, reduction reaction, oxidation reaction, hydrogenation reaction, catalytic reduction reaction, isomerization reaction, cleavage reaction, disproportionation reaction, catalytic decomposition reaction, selective catalytic reduction reaction, selective oxidation reaction, racemization reaction, etc. Further examples include radical polymerization, cationic polymerization, anionic polymerization, coordination polymerization, inorganic reaction, etc. used in polymer synthesis, but are not limited to these, and various other chemical reactions can be mentioned. In addition, a catalytic reaction utilizing the action of a catalyst is also preferable.
Among these, reactions in which the reaction raw materials or reaction products produce precipitation are preferred, such as nanoparticle synthesis, hydrothermal synthesis, and surface modification of fine particles, and a preferred example is the synthesis reaction of zeolite.
The above chemical reactions can be usually caused by heating the reaction raw materials that cause the target reaction by microwave irradiation. Alternatively, the reaction raw materials can be passed through a catalyst and irradiated with microwaves to cause a chemical reaction. For example, the reaction raw materials can be supplied into the above-mentioned reaction tube, a standing wave is formed by microwave irradiation, and the reaction raw materials in the reaction tube are heated by the maximum part of the magnetic field strength of the standing wave to cause a chemical reaction. Alternatively, a catalyst can be placed in the reaction tube, the reaction raw materials are passed through the catalyst, and the reaction raw materials are heated by the maximum part of the magnetic field strength of the standing wave in the same manner as above, or the catalyst can be heated to cause a chemical reaction.

The above chemical reactions themselves are publicly known, and the chemical reaction method of the present invention can be applied to a wide range of publicly known chemical reactions, except for the control of the heating state.

In the chemical reaction method of the present invention, the conditions such as reaction time, reaction temperature, reaction substrate, reaction medium, etc. may be appropriately set according to the target chemical reaction. For example, chemical reaction conditions can be appropriately set by referring to Chemistry Handbook (edited by Suzuki Shuichi and Mukaiyama Mitsuaki, Asakura Publishing, 2005), Microwave Chemical Process Technology II (edited by Takeuchi Kazuhiko and Wada Yuji, CMC Publishing, 2013), JP 2010-215677 A, JP 2011-137226 A, etc.

The chemical reaction device 1 of the present invention can be configured to heat the reaction raw materials 30 throughout the reactor 10 by moving the cavity resonator 21 around the reaction raw materials 30 placed in the reactor 10. In addition, the chemical reaction caused by heating the reaction raw materials 30 may be a chemical reaction in the reaction raw materials 30 themselves that produces a reaction product, or a chemical reaction may occur in the reaction raw materials 30 due to the action (typically catalytic action) of the heated object to be heated.

The present invention will be described in more detail below with reference to examples, but the present invention should not be construed as being limited to these examples.

[Example 1]
In Example 1, microwave heating synthesis of zeolite was carried out using the chemical reaction apparatus 1 shown in Fig. 1. The chemical reaction apparatus 1 is a pressurizable semi-flow type chemical reaction apparatus including a microwave oscillator (2.4 to 2.5 GHz, maximum output 100 W), a _TM110 mode cavity resonator 21 in which the magnetic field is maximized at the central axis, a boost pump 14, ball valves 12, 13, 16, etc. A quartz reaction tube with an outer diameter of 8 mm and an inner diameter of 6 mm was used as the reactor 10, and the cavity resonator 21 was installed so that the central axis C of the cavity resonator 21 coincided with the central axis Ct of the reactor 10 and was movable along the reactor 10. Then, the raw material solution of zeolite, which is the reaction raw material 30, was heated in the reactor 10.
The raw material solution was prepared by dissolving aluminum chloride hexahydrate, a 30% by mass solution of colloidal silica, and sodium hydroxide in pure water, mixing them so that the ratio was Na:Al:Si:H ₂ O = 4:1:1:53, and then stirring at room temperature for 24 hours. After that, the raw material solution was filled into the reactor 10 at a flow rate of 120 ml/h using a double plunger pump as a liquid delivery means, and the ball valve 12 was opened. Then, the cavity resonator 21 was moved from the ball valve 13 side to the ball valve 12 side along the reactor 10 with the moving speed of 0.5 mm/s and the set heating temperature of 150°C, and microwave heating was performed over the entire length of the reactor 10. A radiation thermometer (not shown) was used to measure the temperature, and the surface temperature of the reactor 10 was measured. The pressure inside the reaction tube during heating was maintained in the range of 0.5 MPa to 0.8 MPa by adjusting the discharge amount of the working fluid (water) of the boost pump 14. After heating, the ball valve 13 was opened and the piston 11 was driven to discharge the solution (reaction product). The discharged material was centrifuged to collect the precipitate, which was then washed several times by centrifugation using pure water. The precipitate was then dried and subjected to particle analysis. An X-ray diffraction device (Rigaku's SmartLab) was used for the particle analysis.

With regard to the time change of temperature, incident wave output, reflected wave output, and resonance frequency during heating of the zeolite raw material solution, it was possible to control the temperature within ±2°C of the set temperature of 150°C, and the reflected wave was small, enabling efficient microwave heating. Note that since the thermal synthesis was performed near the boiling point, bubbles may be generated if the pressure inside the reaction tube is close to the saturated vapor pressure. In this experiment, several bubbles were generated during the synthesis, but the fluctuations in temperature and resonance frequency associated with the generation of bubbles were small, enabling stable heating control.
From the X-ray diffraction pattern of the synthesized product, peaks indicating the synthesis of SOD (sodalite) type zeolite were confirmed.
Generally, zeolite raw material liquid contains many ions and has high electrical conductivity, so magnetic field heating is suitable for efficient heating.

[Example 2]
In Example 2, microwave heating synthesis of zeolite was performed using a slurry containing fly ash (coal ash) as the raw material solution of zeolite, which is the reaction raw material 30. A chemical reaction apparatus 1 similar to that of Example 1 was used, except that a quartz reaction tube having an outer diameter of 6 mm and an inner diameter of 4 mm was used.
The raw material solution (raw material suspension) was prepared by adding 5M aqueous sodium hydroxide solution to fly ash (JIS standard IV type) and stirring at room temperature for 10 minutes. The amount of fly ash contained in the raw material solution was about 35% by mass. After that, the ball valve 12 was opened and the raw material solution was filled into the reactor 10 at a flow rate of 120 ml/h using a double plunger pump as a liquid delivery means. Then, the cavity resonator 21 was moved from the ball valve 13 side to the ball valve 12 side along the reactor 10 with the moving speed of 2 mm/min and the set heating temperature of 140° C., and microwave heating was performed over the entire length of the reactor 10. The microwave heating time of the raw material solution was 10 minutes. The pressure inside the reactor during heating was maintained in the range of 0.8 MPa to 1.0 MPa by adjusting the discharge amount of the working fluid (water) of the boost pump 14. After heating, the ball valve 13 was opened and the piston 11 was driven to discharge the solution (reaction product). The discharged material was centrifuged to recover the precipitate, which was then washed several times with pure water by centrifugation. The precipitate was then dried and subjected to particle analysis. For particle analysis, the above-mentioned X-ray diffraction device and scanning electron microscope (S-4800 manufactured by Hitachi High-Technologies Corporation) were used.

Figure 7 shows the X-ray diffraction patterns of the fly ash particles used as the raw material and the particles after the microwave heating treatment. In addition to the peaks of quartz and mullite contained in the raw material, a peak indicating that hydroxysodalite, a type of zeolite, was synthesized by the microwave heating treatment was confirmed. As shown in Figure 8, the scanning electron microscope images of the fly ash particles used as the raw material and the particles after the microwave heating treatment confirmed that the heating treatment increased the undulations on the particle surface and increased the surface area of the particles.
From the above, it was found that the chemical reaction apparatus 1 of the present invention can be applied to microwave chemical synthesis using a slurry-like raw material solution.

[Example 3]
In Example 3, the chemical reaction apparatus 1 shown in FIG. 1 was used to carry out microwave heating synthesis of platinum nanoparticles using a highly viscous raw material solution. The chemical reaction apparatus 1 is a pressurizable semi-flow type chemical reaction apparatus including a microwave oscillator (900-930 MHz, maximum output 300 W), a TM ₀₁₀ mode cavity resonator 21 in which the electric field is maximized at the central axis, a boost pump 14, ball valves 12, 13, 16, and the like. A quartz reaction tube having an outer diameter of 10 mm and an inner diameter of 8 mm was used as the reactor 10, and the cavity resonator 21 was installed so that the central axis C of the cavity resonator 21 coincided with the central axis Ct of the reactor 10 and was movable along the reactor 10. Then, the raw material solution of platinum nanoparticles, which is the reaction raw material 30, was heated in the reactor 10.
The raw material solution was a glycerin solution (viscosity: 20 Pa·s or more (25° C.)) in which 200 mM chloroplatinic acid hexahydrate and 20% by mass of polyvinylpyrrolidone (weight average molecular weight 10,000) were dissolved. A double plunger pump was used as a liquid delivery means, and the raw material solution was filled into the reactor 10 by opening the ball valve 12. Then, the cavity resonator 21 was moved along the reactor 10 from the ball valve 13 side to the ball valve 12 side with the moving speed of the cavity resonator 21 set to 10 mm/min and the heating temperature set to 140° C., and microwave heating was performed over the entire length of the reactor 10. The microwave heating time of the raw material solution was equivalent to 4 minutes. A radiation thermometer (not shown) was used to measure the temperature, and the surface temperature of the reactor 10 was measured. The pressure inside the reactor during heating was maintained at atmospheric pressure. After the microwave heating process, the ball valve 13 was opened and the piston 11 was driven to discharge the reaction solution (reaction product). For particle analysis, a transmission electron microscope (TEM, TECNAI G2 manufactured by FEI) was used to observe particles in the reaction solution.

The color of the solution after the microwave heating treatment changed from orange before heating to black, which is characteristic of solutions containing platinum nanoparticles. The transmission electron microscope image shown in Figure 9 confirms that platinum nanoparticles with particle sizes of 2 to 5 nm were synthesized.
From the above, it has been found that the chemical reaction apparatus 1 of the present invention can be applied to microwave heating synthesis using a highly viscous raw material solution.

[Example 4]
In Example 4, microwave heating synthesis of zeolite was performed in the same procedure as in Example 1, except that the raw material solution and microwave heating conditions were different. The raw material solution was prepared by dissolving sodium aluminate, a 30 mass% colloidal silica solution, and sodium hydroxide in pure water, mixing them so that Na:Al:Si:H ₂ O = 4:1:1:90 (molar ratio), and then stirring at room temperature for 240 hours. The moving speed of the cavity resonator 21 during microwave heating was 1 cm/min, and the set heating temperature was 140°C. The microwave heating time of the raw material solution was equivalent to 2 minutes. The precipitate obtained through centrifugation was dried, and particle analysis was performed using X-ray diffraction measurement and a transmission electron microscope. The X-ray diffraction pattern shown in FIG. 10 confirmed the presence of a single phase of FAU-type zeolite. The transmission electron microscope image shown in FIG. 11 confirmed the generation of crystal particles with a particle diameter of 10 to 30 nm.
Furthermore, nitrogen adsorption measurements (measuring device: BELSORP-MAX manufactured by Microtrac-Bell) were performed to examine the pore characteristics of the zeolite. As a pretreatment for the measurement, heating was performed at 150°C for 24 hours. From the nitrogen adsorption isotherm shown in Figure 12, pores were confirmed in the micropore (less than 2 nm), mesopore (2 nm or more and less than 50 nm), and macropore (50 nm or more) regions, and the pore volumes by the BET (Brunauer-Emmett-Teller) method were 0.24, 0.54, and 0.50 cm ³ /g, respectively. Furthermore, as a result of performing a BET plot, the specific surface area was 670 m ² /g. Furthermore, the analysis result of the pore size distribution of the mesopores by the BJH method is shown in Figure 13. In Figure 13, a peak was observed near 44 nm, and it was found that a large number of mesopores were present.
From the above, it was found that zeolite nanoparticles having a mesoporous structure can be synthesized without adding an organic structure-directing agent, which is generally considered to be indispensable for synthesizing zeolite nanoparticles having a mesoporous structure.

REFERENCE SIGNS LIST 1 Chemical reaction device 10 Reactor 11 Piston 12, 13 Ball valve 21P, 13P Flow path 14 Booster pump 15 Pipe 16 Gate valve (ball valve)
20 Temperature control mechanism 21 Cavity resonator 21A Microwave irradiation space 30 Reaction raw material 32 Reaction product (chemical substance)
C: central axis of the cavity resonator Ct: central axis of the reactor

Claims (5)

A reactor having a tubular structure with both ends open ;
a temperature control mechanism movably disposed along the reactor;
A piston slidably disposed in the reactor from one end (I) of the reactor;
A ball valve (ii) disposed at the other end (II) of the reactor;
A ball valve (i) provided on a side surface (A) on one end (I) side of the reactor for feeding reaction raw materials into the reactor;
a piping provided on a side surface (B) other than the side surface (A) on the one end (I) side of the reactor, for feeding a working fluid into the reactor by the action of a boost pump;
The piston and/or the boost pump constitute a pressurizing means for pressurizing the inside of the reactor and also constitute an extracting means for extracting the chemical substance obtained in the reactor,
The ball valve (ii) constitutes a pressure regulating mechanism for creating a blocked or narrowed state at the outlet portion of the reactor and also constitutes an outlet for discharging the chemical substance obtained in the reactor;
A chemical reaction apparatus in which the temperature control mechanism is moved along the reactor , thereby continuously heating the reaction raw materials placed in the reactor under pressurized conditions created by the pressurizing means and the pressure regulating mechanism to produce chemical substances in the reactor, and the chemical substances are discharged from the outlet by the removal means. The chemical reaction device according to claim 1, wherein the reactor has a portion where the temperature control mechanism moves linearly. 3. The chemical reaction device according to claim 1, wherein the temperature control mechanism is a non-contact heating device that uses electromagnetic wave irradiation. 4. The chemical reaction device according to claim 3 , wherein the non-contact heating device includes a cavity resonator having an electromagnetic wave irradiation space. 5. The chemical reaction device according to claim 4, wherein the cavity resonator forms a single-mode standing wave of TM _mn0 mode (m is an integer of 0 or more, n is an integer of 1 or more) or TE _m0p mode (m and p are integers of 1 or more ) by irradiating an electromagnetic wave into the cavity resonator.

Images