JP5030222B2 - Photocatalytic microreactor - Google Patents

Description

  The present invention is provided with a microreactor made of a light transmissive material and having a microchannel through which reaction raw materials are circulated, raw material feeding means for feeding the reaction raw material into the microchannel, and an inner surface of the microchannel. The present invention relates to a photocatalytic microreactor comprising a photocatalyst layer and light irradiation means for irradiating the photocatalyst layer with light.

  In a photocatalytic chemical reaction using a photocatalyst, for example, in the case of a batch-type macro reactor, the reaction is performed by suspending the photocatalyst powder in the raw material liquid of the macro reaction vessel, so that light is scattered by the suspended photocatalyst powder. In addition, the photocatalytic reaction is caused by the decay of photons based on the increase of the solvent and the reaction product in the reaction vessel, and further, when the reaction product is crystallized, the photons are attenuated by the crystals. There was a limit in making the process proceed efficiently. And since the operation | work which isolate | separates a photocatalyst from a reaction product after reaction is required, operation was complicated.

In order to solve each of the above problems, a microreactor made of a light-transmitting material and having a microchannel through which a reaction raw material liquid is circulated, a raw material feed unit for feeding the reaction raw material liquid into the microchannel, and the micro There has been proposed a photocatalytic microreactor comprising a photocatalyst layer provided on the inner surface of a flow path and a light irradiation part for irradiating the photocatalyst layer with light (Patent Document 1). Since the photocatalytic microreaction apparatus of Patent Document 1 can cause a reaction molecule contained in the raw material liquid to undergo a photocatalytic reaction while allowing the raw material liquid to pass through a fine microchannel having a photocatalyst layer, The problem of the reactor has been improved, and the photocatalytic reaction can be efficiently advanced.
JP 2005-279595 A

  However, since the conventional photocatalytic microreactor has been proposed based on the above-described batch method, in which a raw material liquid having a high affinity with the photocatalyst is used, in the case of a titanium dioxide catalyst, For a raw material having a low protonic polarity, that is, a raw material liquid having a low affinity for the titanium dioxide catalyst, it is dissolved in a highly hydrophilic solvent and circulated through the microchannel as a hydrophilic raw material solution to carry out a photocatalytic reaction. I am letting. For this reason, there is a limit in increasing the ratio of the raw material molecules that cause the photocatalytic reaction on the surface of the photocatalyst.

  It is an object of the present invention to be able to effectively increase the existence ratio on the surface of the photocatalyst in the microchannel even if the raw material liquid has a low affinity for the photocatalyst, and to advance the photocatalytic reaction more efficiently. It is an object of the present invention to provide a photocatalytic microreactor that is made possible.

  In addition, when the product produced by the photocatalytic reaction in the raw material liquid having a low affinity for the photocatalyst is more hydrophilic than the reaction raw material liquid, the product is effectively separated on the downstream side of the microchannel. An object of the present invention is to provide a photocatalytic microreactor equipped with an extraction microchannel that can be extracted.

In order to solve the above problems, a photocatalytic microreaction apparatus according to a first aspect of the present invention includes a microreactor comprising a microchannel made of a light-transmitting material and through which reaction raw materials are circulated, and the microchannel A photocatalytic microreaction apparatus comprising: a raw material feeding means for feeding a reaction raw material into the photocatalyst layer; and a photocatalyst layer provided on an inner surface of the microchannel. The low-affinity (hydrophobic) organic liquid raw material or the organic solution raw material in which the reaction raw material is dissolved in a hydrophobic organic solvent, the raw material feeding means is the organic liquid raw material or the organic solution raw material Is configured to be capable of forming a pipe flow in a state in which the gas material flows along the inner surface of the micro-channel and the gas source flows through the central portion.

According to the present invention, the reaction raw material, and gas material, for the case an organic material solution obtained by dissolving the reaction material in a hydrophobic organic liquid material or a hydrophobic organic solvent, the material feed means, The organic liquid raw material or the organic solution raw material flows along the inner surface of the microchannel, and a pipe flow in a state where the gaseous raw material flows through the central portion can be formed. Therefore, even an organic material solution obtained by dissolving the reaction material in a hydrophobic organic liquid material or a hydrophobic organic solvent by forming a pipe flow using one the gas material is a reaction raw material, the total amount Can be forced to localize in the vicinity of the surface of the photocatalyst layer and pass through the microchannel in a laminar flow state.

That is, without using a high photocatalytic affinity solvent, an organic material solution obtained by dissolving the reaction material in a hydrophobic organic liquid material or a hydrophobic organic solvent, to localize the total amount in the vicinity of the surface of the photocatalyst layer It is possible to pass through the microchannel in a state where it is in a wet state. As a result, the gas source also comes into contact with the organic liquid source or the organic solution source obtained by dissolving the reaction source in the organic solvent in the vicinity of the photocatalyst layer, so that the photocatalytic reaction can proceed with high efficiency. An effect is obtained.

  The photocatalytic microreactor according to the second aspect of the present invention is the photocatalytic microreactor according to the first aspect, wherein the photocatalyst layer is provided on the entire inner surface of the microchannel. It is what. According to the present invention, since the photocatalyst layer is provided on the entire inner surface of the microchannel, the photocatalytic reaction can be performed efficiently.

A photocatalytic microreactor according to a third aspect of the present invention comprises a microreactor made of a light-transmitting material and having a microchannel through which a reaction raw material is circulated, and a raw material feed for feeding the reaction raw material into the microchannel Means, a photocatalyst layer provided on the inner surface of the microchannel, and a light irradiation means for irradiating the photocatalyst layer with light, wherein the reaction raw material is a gas a raw material, for the case an organic material solution obtained by dissolving the reaction material in a hydrophobic organic liquid material or a hydrophobic organic solvent, the material feed means, said organic liquid material or the organic solution starting material is the micro It is configured to be able to form a pipe flow that flows along the inner surface of the flow path and in which the gaseous raw material flows through the central portion.

According to the present invention, the same effects as the first embodiment can be obtained, by the light irradiation means, depending on the reaction performed in the photocatalyst and micro channel used, the light of the appropriate wavelength efficiently irradiated can do.

  The photocatalytic microreaction apparatus according to a fourth aspect of the present invention is the photocatalytic microreaction apparatus according to the third aspect, wherein the photocatalyst layer is provided on the entire inner surface of the microchannel, and the light irradiation means Is provided outside the microreactor. According to the present invention, it is possible to efficiently perform light irradiation on the photocatalyst.

  The photocatalytic microreaction apparatus according to the fifth aspect of the present invention is the photocatalytic microreaction apparatus of the third aspect or the fourth aspect, wherein the light irradiation means mainly emits ultraviolet light of 200 nm to 400 nm as a light source. A light emitting diode is provided. According to the present invention, since the light emitting diode is used as the light source of the light irradiation means, it is possible to realize space saving and low photon cost of the photocatalytic microreactor.

The photocatalytic microreaction apparatus according to a sixth aspect of the present invention is the photocatalytic microreaction apparatus according to any one of the first to fifth aspects, wherein the gas raw material is carbon dioxide. To do.
According to the present invention, in addition to the same effect as the first aspect, since the pipe flow is formed in the micro-channel using carbon dioxide as a gas raw material, it is useful with a hydrophobic organic liquid raw material. The photosynthesis reaction for obtaining the compound can proceed with high efficiency.

A photocatalytic microreaction apparatus according to a seventh aspect of the present invention is the photocatalytic microreaction apparatus according to any one of the first to fifth aspects, further communicated with an outlet of the microchannel. An extraction microchannel is provided, which is combined with an aqueous liquid and has a contact surface between the two liquids as a boundary when the photocatalytic reaction product is more hydrophilic than the reaction raw material. Two layers of liquid are circulated in a laminar flow state, and the product of the photocatalytic reaction can be transferred from the reaction raw material into the aqueous liquid through the contact surface. is there.
Here, the “aqueous liquid” is used to mean all hydrophilic liquids such as methanol in addition to water.

  According to the present invention, when the product of the photocatalytic reaction forming the pipe flow is more hydrophilic than the reaction raw material, it is sent from the outlet of the microchannel to the extraction microchannel, and in a laminar state with the aqueous liquid. Since the product is merged so that the product can be transferred from the reaction raw material to the aqueous liquid via the contact surface, the product generated by the photocatalytic reaction in the microchannel can be immediately and easily In addition, it is possible to stably separate and extract from the reaction raw material while maintaining the same flow rate as in the microchannel. That is, there is no problem of complicated separation and extraction.

A photocatalytic microreaction apparatus according to an eighth aspect of the present invention comprises a microreactor made of a light-transmitting material and having a microchannel through which a reaction material is circulated, and a feeding means for feeding the reaction material into the microchannel. And a photocatalytic microreaction apparatus comprising a photocatalyst layer provided on the inner surface of the microchannel, further comprising an extraction microchannel communicated with an outlet of the microchannel, and the reaction When the raw material is a hydrophobic organic liquid raw material or an organic solution raw material in which a reaction raw material is dissolved in a hydrophobic organic solvent, and the product of the photocatalytic reaction is more hydrophilic than the reaction raw material, The micro flow path is joined with an aqueous liquid and two layers of liquid are circulated in a laminar flow state with the contact surface of both liquids as a boundary, and the reaction product is passed through the contact surface from the reaction raw material. Water system And it is characterized in that it is configured to Utsureru throughout the body.

  Also in the present invention, the product is sent from the outlet of the microchannel to the extraction microchannel and merged with the aqueous liquid in a laminar flow state, and the product is contained in the aqueous liquid from the reaction raw material through the contact surface. Therefore, the product generated by the photocatalytic reaction in the microchannel can be separated and extracted from the reaction raw material immediately and easily while maintaining the same flow rate as in the microchannel. can do. That is, there is no problem of complicated separation and extraction.

A photocatalytic microreaction apparatus according to a ninth aspect of the present invention includes a microreactor made of a light-transmitting material and having a microchannel through which a reaction raw material is circulated, and a feeding means for feeding the reaction raw material into the microchannel. A photocatalyst microreaction apparatus comprising: a photocatalyst layer provided on an inner surface of the microchannel; and a light irradiation means for irradiating the photocatalyst layer with light. comprising a communicated extraction microchannel for the, the reaction raw material, an organic material solution obtained by dissolving the reaction material in a hydrophobic organic liquid material or a hydrophobic organic solvent, the product of the photocatalytic reaction is the reaction In contrast to the case where the raw material is more hydrophilic than the raw material, the extraction micro-channel is combined with an aqueous liquid, and two layers of liquid are circulated in a laminar flow state with the contact surface of both liquids as a boundary. Things before By being composed of the reaction in the raw material as Utsureru in the aqueous liquid through the contact surface and is characterized in.

According to the present invention, the same effects as the eighth aspect is obtained by the light irradiation means, depending on the reaction performed in the photocatalyst and micro channel used, the light of the appropriate wavelength efficiently irradiated can do.

  The photocatalytic microreaction apparatus according to a tenth aspect of the present invention is the photocatalytic microreaction apparatus according to any one of the first to ninth aspects, wherein the photocatalyst is titanium dioxide. To do. According to the present invention, high photocatalytic activity can be obtained with titanium dioxide.

  A carboxylic acid production method according to an eleventh aspect of the present invention is a carboxylic acid production method for finally producing a carboxylic acid from a carboxylic acid raw material through an oxidation reaction step, wherein at least a part of the oxidation reaction step. The step is performed using the photocatalytic microreaction apparatus of the first aspect or the third aspect.

The carboxylic acid production method for producing carboxylic acid finally from the carboxylic acid raw material through an oxidation reaction step is conventionally a large-scale reaction vessel using an oxidizing agent such as nitric acid, permanganate, and dichromate. It is done in Therefore, a large amount of oxidizing agent is provided.
According to the present invention, at least a part of the multistage reaction is performed using the photocatalytic microreaction apparatus of the first aspect or the third aspect, so that the amount of the oxidizing agent used is greatly reduced. Or it can be omitted.

A photocatalytic reaction method according to a twelfth aspect of the present invention comprises a microreactor comprising a microchannel through which a reaction raw material is circulated, and a feeding means for feeding the reaction raw material into the microchannel. A photocatalytic microreaction apparatus comprising a photocatalyst layer provided on an inner surface of the microchannel, wherein a hydrophobic organic liquid raw material or The reaction is carried out by feeding an organic solution raw material in which the reaction raw material is dissolved in a hydrophobic organic solvent.

According to the present invention, even if the reaction raw material is a hydrophobic organic liquid raw material or an organic solution raw material in which the reaction raw material is dissolved in a hydrophobic organic solvent, a high specific surface area with the photocatalyst is provided in the microchannel. An effective reaction system can be realized and the photocatalytic reaction can proceed with high efficiency.

A photocatalytic reaction method according to a thirteenth aspect of the present invention comprises a microreactor having a microchannel through which a reaction raw material is circulated, and a feeding means for feeding the reaction raw material into the microchannel. A photocatalytic reaction method performed using a photocatalytic microreactor comprising a photocatalyst layer provided on an inner surface of the microchannel and a light irradiation means for irradiating light to the photocatalyst layer, wherein the feeding from the means, as a reaction raw material, it is characterized in that to perform the reaction by feeding an organic material solution obtained by dissolving the reaction material in a hydrophobic organic liquid material or a hydrophobic organic solvent.
According to the present invention, the same effects as the 12th aspect can be obtained, by the light irradiation means, depending on the reaction performed in the photocatalyst and micro channel used, the light of the appropriate wavelength efficiently irradiated can do.

  According to the present invention, the organic liquid material having a low affinity for the photocatalyst or the organic solvent having a low affinity for the photocatalyst by forming a pipe flow using a gas material that is one of the reaction raw materials. Even if it is the organic solution raw material in which the reaction raw material is dissolved, the entire amount can be forcibly localized in the vicinity of the surface of the photocatalyst layer and passed through the microchannel in a laminar flow state. That is, without using a solvent having a high affinity for the photocatalyst, the organic liquid raw material having a low affinity for the photocatalyst or an organic solution raw material in which the reaction raw material is dissolved in the organic solvent is placed in the vicinity of the surface of the photocatalyst layer. The microchannel can be passed in a localized state. As a result, the gas raw material also comes into contact with the organic solution raw material in which the reaction raw material is dissolved in the organic liquid raw material or the organic solvent in the vicinity of the photocatalyst layer, so that the photocatalytic reaction can proceed with high efficiency. Is obtained.

Example 1
An example of an embodiment of the present invention will be described with reference to FIGS.
FIG. 1 is a perspective view showing a first embodiment of a photocatalytic microreactor according to the present invention. FIG. 2 is a sectional view showing a first embodiment of the photocatalytic microreactor according to the present invention. FIG. 3 is an enlarged view of the II cross section of the A part of FIG. 2, and is a diagram showing a pipe flow state in the micro flow path. 4 is a cross-sectional view taken along the line II-II in FIG.

As shown in FIGS. 1 and 2, the photocatalytic microreactor 1 according to the present embodiment is configured by joining a Pyrex (registered trademark) or quartz substrate 2 and a top plate 3. A groove 6 having a width of 500 μm, a depth of 10 to 500 μm, and a length of 50 mm is formed on the surface of the substrate 2 by etching or machining. A photocatalyst layer 5 is formed in the groove 6 as shown in FIG. In this embodiment, titanium oxide (TiO ₂ ) is used as the photocatalyst. Of course, the photocatalyst is not limited to titanium oxide. The microchannel 4 is formed by joining the substrate 2 provided with the groove 6 in which the photocatalyst layer 5 is formed and the top plate 3. The photocatalyst layer 5 is not formed on a portion of the top plate 3 that forms the upper surface of the microchannel 4, and the photocatalyst is provided only on the side wall surface and the bottom surface of the microchannel 4 as shown in FIG. 4. As a result, the light irradiation means described later is provided on the top surface of the top plate 3, and the photocatalyst can be efficiently irradiated with light. If a visible light responsive photocatalyst is used, it is possible to use sunlight as an excitation light source for the photocatalyst.

  A first supply port 11 for supplying the raw material to the micro flow path 4 is provided at one end of the groove 6 provided in the substrate 2. Further, the top plate 3 is provided with a second supply port 12 at a position substantially opposite to the first supply port 11 when bonded to the substrate 2. Further, the top plate 3 is provided with a takeout port 13 through which the reaction solution that has passed through the microchannel 4 is taken out.

One of the first supply port 11 and the second supply port 12 is used as a gas raw material supply port, and the other is a low affinity organic liquid raw material or a low affinity organic solvent for the photocatalyst. It is used as a supply port for the organic solution raw material in which the reaction raw material is dissolved.
Tube connectors 18 are provided at the first supply port and the second supply port, and are connected to raw material feeding means such as syringe pumps 16 and 17 via the microtubes 14 and 15. Etc. are configured to be able to adjust the supply speed of the gas raw material and the organic liquid raw material so as to form a pipe flow in a state where the gas raw material flows through the central portion of the micro flow path 4. ing. The reaction solution that has passed through the microchannel 4 is taken out from the takeout port 13.

As a light irradiation means for irradiating the photocatalyst layer 5 with light in order to induce a photoreaction, a light irradiation device 8 using an ultraviolet light emitting diode 19 (main wavelength: 365 nm, output: 9.8 mW) as a light source is used. Is desirable. By using a light emitting diode as a light source of the light irradiation device 8, space saving and low photon cost of the photocatalytic micro device 1 can be realized. In the light irradiation device 8, light is provided on the top surface of the top plate 3, and the ultraviolet light emitting diodes 19 are arranged in series along the microchannel 4.
In the case where a visible light responsive photocatalyst is used for the photocatalyst layer 5, sunlight can be used as an excitation light source for the photocatalyst.

  FIG. 5 shows a modification of the microchannel 4 in which the photocatalyst layer 5 described with reference to FIG. 4 is formed. That is, the photocatalyst layer 5 can be formed on the top plate 3 on the upper surface of the microchannel 4, and the photocatalyst can be provided on the entire surface of the microchannel 4. In this case, the photocatalyst layer 5 is desirably formed thin enough to transmit the light irradiated by the light irradiation device 8. As described above, when the photocatalyst is provided on the entire surface of the microchannel 4, a light irradiation device (not shown) is further provided on the lower surface side of the substrate 2, and light is transmitted from the upper surface and the lower surface of the microchannel 4. It is preferable to be configured to be irradiated. When the photocatalyst is formed on the entire surface of the microchannel 4, the photocatalyst layer 5 is formed in a slit shape so that the light irradiated by the light irradiation device 8 can be easily transmitted into the microchannel 4. You can also.

Using the photocatalytic microreactor 1 as described above, oxygen is used as a gas raw material supplied from the first supply port 11, and toluene is used as an organic liquid raw material having a low affinity for the photocatalyst supplied from the second supply port 12. Reaction.
The flow rate of toluene is set to 7 μl / min (microliter / minute) and the flow rate of oxygen is adjusted to form a pipe flow as shown in FIG. The light irradiation by was performed. The flow rate of oxygen is set to 0 (no pipe flow phenomenon), 175, 350, 525, 700, 875 μl / min, the reaction solution taken out from the take-out port 13 is subjected to gas chromatography, and the amount of product in the reaction solution Was measured. The result is shown in FIG.

  Benzaldehyde and benzyl alcohol were produced when the flow rate of oxygen was 0, that is, when the pipe flow phenomenon was not formed. When oxygen was supplied to form a pipe flow phenomenon, in addition to benzaldehyde and benzyl alcohol, o-cresol, m-cresol, and p-cresol (particularly o), which were not observed when oxygen was not circulated, were added. -Cresol) was confirmed to be produced. When the flow rate of oxygen is increased, the residence time in the microchannel is also shortened due to the pipe flow formation. That is, the result of FIG. 6 shows that the reaction rate per unit time increases with an increase in the flow rate of oxygen, and the reaction is performed efficiently.

In this embodiment, the residence time of the reaction liquid in the micro flow path can be calculated using a model for exchanging momentum between gas and liquid in the pipe flow by LEVY. According to this calculation, the residence time of the reaction solution in the microchannel when the oxygen flow rate is 0 is 107.1 seconds, but the residence time when the oxygen flow rate is 700 μl / min is 15.1. In the case of 4 seconds and 875 μl / min, it is about 12.8 seconds, and it can be said that toluene is oxidized and benzaldehyde and o-cresol are produced in a very short time.
That is, by forming a pipe flow using oxygen which is one of the reaction raw materials, even if toluene having a low affinity for the photocatalyst is used, the entire amount thereof is forcibly localized near the surface of the photocatalyst layer 5. Therefore, it is not necessary to use a solvent having high affinity with the photocatalyst because the microchannel can be passed through in a laminar flow state. Thereby, since oxygen also contacts with toluene in the vicinity of the photocatalyst layer 5, the photocatalytic reaction can be advanced with high efficiency.

  For aprotic and low polarity solvents such as toluene, the affinity of titanium oxide, which is a photocatalyst, is extremely low. Conventionally, a small amount of toluene is dissolved in an acetonitrile solution, and the toluene-containing acetonitrile solution is used. Then, an oxidation reaction experiment of toluene was conducted. With the photocatalytic microreaction apparatus 1 of the present invention, a reaction system having a high specific surface area with respect to a raw material liquid having a low affinity for the photocatalyst can be realized, and the toluene oxidation reaction can be performed with high efficiency. Furthermore, in this example, a reaction that did not occur in the conventional reaction system (a reaction that generates o-cresol) was observed. It can be said that there is a possibility that a new reaction can be realized.

In addition, in the oxidation reaction of toluene, the length of the microchannel 4 is set to be long and the photoreaction time is lengthened, so that the oxidation reaction further proceeds after the reaction of toluene → benzaldehyde to generate benzoic acid. It is also possible.
In addition, a reaction solution in which toluene as a reaction raw material is dissolved in another organic solvent having a low affinity for a photocatalyst such as n-hexane is circulated through the microchannel 4 to form a pipe flow with oxygen. In addition, the reaction solution can be forcibly localized in the vicinity of the surface of the photocatalyst layer 5 to pass through the microchannel 4 in a laminar flow state, and the photocatalytic reaction can proceed with high efficiency.

  In addition to the oxidation reaction of toluene described above, various useful reactions can be efficiently performed by using the photocatalytic microreaction apparatus 1 according to the present embodiment. Examples include synthesis of phenol by direct oxidation of benzene (Reaction Example 1-1), production of a nylon synthesis intermediate by oxidation of cyclohexane (Reaction Example 1-2), and the like.

<Reaction Example 1-1>
The industrial synthesis of phenol is usually carried out by a reaction called cumene method comprising three stages of reaction using benzene as a raw material. This reaction has a problem that it requires a lot of energy and has a large burden on the environment because many harmful by-products are generated. Therefore, if phenol can be synthesized by directly oxidizing benzene in a one-step reaction, it is useful as a production method with low cost and low environmental load.

  When a photocatalyst, for example, titanium oxide is used, benzene is directly oxidized to produce phenol. However, a photocatalyst such as titanium oxide is not compatible with a lipophilic organic compound raw material such as benzene. Therefore, a part of the titanium oxide, which is a hydrophilic photocatalyst, is changed to lipophilic, and special catalyst particles having both hydrophilic and lipophilic properties are synthesized, and titanium oxide is arranged at the interface between the raw material benzene and water. By doing so, it has been studied to oxidize benzene with a photocatalyst (titanium oxide).

  For this benzene oxidation reaction, the photocatalytic microreactor 1 according to the present embodiment is used, benzene as an organic liquid raw material, oxygen as a gas raw material is fed, and the total amount of benzene is forcibly formed by forming an oxygen pipe flow. Localize near the surface of the photocatalyst layer 5 and pass through the microchannel in a laminar flow state, and oxygen also comes into contact with benzene in the vicinity of the photocatalyst layer 5, so that the oxidation reaction of benzene proceeds with high efficiency. Can do. Therefore, it is expected that phenol useful as an industrial raw material can be obtained directly by a one-step reaction from benzene without using a special catalyst having both hydrophilicity and lipophilicity as described above.

<Reaction Example 1-2>
Cyclohexanone is an important intermediate for the synthesis of ε-caprolactam, which is a raw material for nylon, and is industrially produced using a cyclohexane oxidation method or a phenol hydrogenation method. These production methods have problems such as high environmental oxides due to the formation of higher-order oxides during the oxidation process and high raw material costs.

  Further, a mixture of cyclohexanone and cyclohexanol called KA oil is obtained by the above production method, and in order to use this for the synthesis of ε-caprolactam, a process of dehydrogenation of cyclohexanol in KA oil is required. There is a problem that this process also has a large energy load.

  Here, it is clear that cyclohexanone can be selectively synthesized from cyclohexane by using a photocatalytic reaction. If the photocatalytic microreactor 1 according to this embodiment is used to form a pipe flow using cyclohexane as an organic liquid source and oxygen as a gas source, the photocatalyst has a large specific surface area and high mass transfer efficiency. In addition to improving the reaction efficiency, the solubility of oxygen in saturated hydrocarbons such as hexane (low affinity for photocatalysts) is higher than hydrophilic solvents such as water and alcohol (high affinity for photocatalysts) Since it is larger than that, the oxygen concentration in cyclohexane can be increased.

  In addition, since oxygen is constantly supplied into cyclohexane by forming an oxygen pipe flow, there is little problem that oxygen is used in the vicinity of the photocatalyst and the oxygen concentration is locally reduced.

  In fact, cyclohexane and oxygen are fed into a photocatalytic microreactor equipped with microchannels with a width of 500 μm and a depth of 300 μm, with titanium oxide supported on the bottom and side surfaces, so that the thickness of the liquid phase is 20 μm. When a flow was formed and light irradiation (450 mW, UV-LED [365 nm]) was performed, cyclohexane was converted to another compound at a conversion rate of 15% by a reaction time of 70 seconds. That is, it can be said that the oxidation reaction of cyclohexane is performed with extremely high efficiency.

  Thus, it is expected that cyclohexanone can be produced at low cost with low environmental burden by efficiently reacting cyclohexane and selectively producing cyclohexanone.

(Example 2)
Next, another example of the embodiment of the present invention will be described.
Example 2 forms a pipe flow in the micro flow path using carbon dioxide as a gas raw material, and uses the carbon dioxide as an organic liquid raw material having a low affinity for the photocatalyst or an organic solvent having a low affinity for the photocatalyst. This is a reaction example in which reduction is performed with an organic solution raw material in which a reaction raw material is dissolved. In this example, the photocatalytic microreactor 1 of Example 1 can be used. Carbon dioxide, which is a gaseous raw material, is supplied from the first supply port 11. Examples of the organic liquid raw material having a low affinity for the photocatalyst supplied from the second supply port 12 include n-hexane, 1-decene, toluene, and benzene.

Usually, when photoreduction of carbon dioxide is carried out in a state where titanium oxide is dispersed, the selectivity of the reduction product greatly depends on the dielectric constant of the solvent, and formate ion (HCOO ⁻ ) is selected in the solvent with a low dielectric constant. It is known that only carbon monoxide (CO) is produced in a solvent having a high dielectric constant.

  By using the photocatalytic microreaction apparatus 1 of the present invention, carbon dioxide can be photoreduced in an organic liquid raw material having a low affinity for titanium oxide as a photocatalyst. That is, the photoreduction can be performed using a low-dielectric constant aprotic solvent such as saturated hydrocarbon (n-hexane or the like) or carbon tetrachloride that cannot disperse titanium oxide. As a result, it is possible to improve the selectivity of formate ion generation and realize a novel reaction, and perform an artificial photosynthesis reaction to obtain a useful compound with an organic liquid raw material having a low affinity for the photocatalyst. It can be used as a photosynthesis device.

(Example 3)
Another example of the embodiment of the present invention will be described with reference to FIGS.
FIG. 7 is a perspective view showing a third embodiment of the photocatalytic microreactor according to the present invention. FIG. 8 is an enlarged view of a main part of the micro flow path of the photocatalytic microreactor of FIG.
As shown in FIG. 7, the photocatalytic microreaction apparatus 21 according to the present embodiment is configured by joining a Pyrex (registered trademark) or quartz substrate 22 and a top plate 23. Grooves having a depth of 10 to 500 μm are formed on the surface of the substrate 22 by etching or machining. As shown in FIG. 8, the groove constitutes a reaction microchannel 24 and an extraction microchannel 26 communicated with an outlet 28 of the reaction microchannel 24.

  In this embodiment, the reaction microchannel 24 has a channel width of 500 μm and a channel length of 50 mm. Further, the channel width of the extraction microchannel 26 is preferably set wider than the reaction microchannel 24, and is set to be about twice as wide as the reaction microchannel 24. Is preferred. The channel length of the extraction microchannel 26 is set to 40 mm. The channel lengths of the reaction microchannel 24 and the extraction microchannel 26 are not particularly limited, and can be set according to the reaction performed in the photocatalytic microreactor 21.

  A first supply port groove 31 and a second supply port groove 32 for supplying the raw material to the reaction microchannel 24 are provided on the inlet side, that is, the upstream side of the reaction microchannel 24. Is formed. In the vicinity of the outlet 28 of the reaction microchannel 24, a third supply port groove 33 is formed for supplying an aqueous liquid to be circulated through the extraction microchannel 26 communicated with the outlet 28. Yes. On the downstream side of the extraction microchannel 26, a first extraction port groove 34 from which the reaction solution that has passed through the reaction microchannel 24 is extracted, and a second extraction port for extracting the aqueous liquid. A groove 35 is formed.

A layer 25 of titanium oxide (TiO ₂ ) is formed as a photocatalyst in the groove in the region forming the reaction microchannel 24. Of course, the photocatalyst is not limited to titanium oxide. If a visible light responsive photocatalyst is used, it is possible to use sunlight as an excitation light source for the photocatalyst. The reaction microchannel 24 is configured by joining the substrate 22 and the top plate 23 together. Similarly to the case of Example 1, the photocatalyst layer 25 may also be formed on the top plate 23 side so as to be provided on the entire surface of the reaction microchannel 24. Further, the photocatalyst layer 25 may be formed in a slit shape so that light irradiated by a light irradiation device (not shown) or sunlight is easily transmitted into the reaction microchannel 24. .

The top plate 23 faces the end portions of the first to third supply port grooves 31, 32, 33 and the first and second extraction port grooves 34, 35 provided in the substrate 22. The first to third supply ports 41, 42, 43 and the first and second take-out ports 44, 45 are provided at the positions to be operated.
One of the first supply port 41 and the second supply port 42 is used as a gas material supply port, and the other is an organic liquid material having a low affinity for the photocatalyst or an organic material having a low affinity for the photocatalyst. It is used as a supply port for an organic solution raw material in which a reaction raw material is dissolved in a solvent. The first supply port 41 and the second supply port 42 are connected to a raw material delivery means (not shown) such as a syringe pump via a microtube 46, and the organic liquid raw material or the like is supplied to the reaction microchannel 24. The feed rate of the gas material and the organic liquid material can be adjusted so as to form a pipe flow in which the gas material flows along the inner surface of the gas and the gas material flows through the central portion.

  Similarly, the third supply port 43 is connected to an aqueous liquid delivery means (not shown) such as a syringe pump via the microtube 47, and is connected to the extraction microchannel 26 that joins the reaction microchannel 25. The supply rate of the aqueous liquid can be adjusted so that the aqueous liquid to be circulated forms a laminar flow with the reaction liquid flowing through the reaction microchannel 24.

  That is, the extraction microchannel 26 is combined with the aqueous liquid and borders the contact surface 27 of both liquids when the product of the photocatalytic reaction in the reaction microchannel 24 is more hydrophilic than the reaction raw material. Thus, two layers of liquid are circulated in a laminar flow state, and the product of the photocatalytic reaction is transferred from the reaction liquid into the aqueous liquid via the contact surface 27.

After the two layers pass through the extraction microchannel 26, the reaction liquid is taken out from the takeout port 44, and the aqueous liquid is taken out from the takeout port 45 and separated.
As a light irradiation means for irradiating the photocatalytic layer 25 with light to induce a photocatalytic reaction, a light irradiation device using an ultraviolet light emitting diode is provided on the top surface of the top plate 23 as in the first embodiment.

  Using the photocatalytic microreactor 21 as described above, oxygen is supplied as a gas raw material from the first supply port 41, and toluene is supplied as a low-affinity organic liquid raw material to the photocatalyst from the second supply port 42, When a photoreaction is performed by forming a pipe flow in the reaction microchannel 24, benzaldehyde, benzyl alcohol, o-cresol, m-cresol, and main products are formed by oxidation of toluene in the same manner as in Example 1. p-cresol (hereinafter referred to as “cresol” includes all ortho, meta, and para isomers).

Benzaldehyde, benzyl alcohol, and cresol are more hydrophilic than toluene, which is a reaction raw material, and are soluble in aqueous solvents such as alcohol and ether.
Therefore, a photocatalytic reaction using a pipe flow of toluene and oxygen is performed in the reaction microchannel 24, and a product such as benzaldehyde is generated. Then, an aqueous system such as alcohol or ether is provided in the extraction microchannel 26. When the solvent is flowed, the reaction solution that has passed through the reaction microchannel 24 and the aqueous liquid merge, and two layers of liquid are circulated in a laminar flow state with the contact surface 27 of both liquids as a boundary. Benzaldehyde, benzyl alcohol, and cresol, which are products of the photocatalytic reaction, are extracted from toluene through the contact surface 27 into the aqueous liquid. As a result, the product generated by the photocatalytic reaction can be immediately and easily separated and extracted from the reaction raw material from toluene, which is the raw material solvent, while maintaining the same flow rate as in the reaction microchannel 24. . That is, there is no problem of complicated separation and extraction.

  Benzyl alcohol has higher solubility in aqueous solvents than cresol, and cresol has higher solubility in aqueous solvents than benzaldehyde. In particular, the difference in solubility in water is significant. Utilizing this fact, water is circulated through the extraction microchannel 26 to leave the main product benzaldehyde in toluene and extract benzyl alcohol and cresol into the aqueous layer and separate them from the reaction solution. It is also possible. It is also possible to separate benzyl alcohol and cresol using the difference in solubility between benzyl alcohol and cresol in an aqueous solvent.

  In addition, a reaction solution in which toluene as a reaction raw material is dissolved in another organic solvent having a low affinity for a photocatalyst such as n-hexane is circulated through a microchannel, and a pipe flow is formed by oxygen to form a photocatalytic reaction. In the case of performing the above, the product can be separated by performing the same operation.

Example 4
Another example of the embodiment of the present invention will be described.
In Example 4, the photocatalytic microreactor 21 of Example 3 is used. As the reaction raw material of this example, an organic liquid raw material having a low affinity for the photocatalyst or a reaction raw material dissolved in an organic solvent having a low affinity for the photocatalyst is used. Even if the reaction raw material is an organic liquid raw material having a low affinity for the photocatalyst or an organic solution raw material in which the reaction raw material is dissolved in an organic solvent having a low affinity for the photocatalyst, Since a reaction system having a high specific surface area with the photocatalyst can be realized, the photocatalytic reaction can proceed with high efficiency.

<Reaction example 4-1>
An example of the organic liquid raw material is toluene. When toluene is circulated through the reaction microchannel 24 of the photocatalytic microreactor 21 shown in FIG. 7 or 8 and the photocatalytic reaction is performed, the toluene is oxidized by dissolved oxygen in toluene, which is an organic liquid raw material. Benzaldehyde and benzyl alcohol are produced in the liquid.

  Also in the present embodiment, the reaction solution is sent from the outlet of the reaction microchannel 24 to the extraction microchannel 26 and merged with the aqueous liquid in a laminar flow state so that the product is contacted from the reaction raw material. Since it is configured to be transferred into the aqueous liquid via the surface 27, the product generated by the photocatalytic reaction in the reaction microchannel 24 can be immediately and easily the same as that in the reaction microchannel 24. It is possible to stably separate and extract from the reaction raw material while maintaining the flow rate. That is, there is no problem of complicated separation and extraction.

  The same applies when a photocatalytic reaction is performed by circulating a reaction solution obtained by dissolving toluene as a reaction raw material in another organic solvent having a low affinity for a photocatalyst such as n-hexane through a microchannel. By performing the operation, the product can be separated.

<Reaction example 4-2>
This reaction example is a synthesis reaction [formula (1)] of p-toluidine by reduction of p-nitrotoluene.

  The reaction raw material p-nitrotoluene (1 mM) was dissolved in hexane, which is an organic solvent having a low affinity for the photocatalyst, and ethanol (1-10 mM) was further added as a sacrificial reagent. When this is circulated through the reaction microchannel 24 of the photocatalytic microreactor 21 shown in FIG. 7 or 8, and the photocatalytic reaction is performed, the reaction of Formula 1 proceeds to produce p-toluidine.

  Here, the solubility of p-nitrotoluene, which is a reaction raw material, and p-toluidine, which is a product, in water is significantly different, being 0.35 g / liter and 6.64 g / liter, respectively. That is, p-toluidine can be extracted with water.

The reaction solution is sent from the outlet of the reaction microchannel 24 to the extraction microchannel 26, and the reaction solution is merged with water in a laminar flow state, whereby the product p-toluidine is the reaction solution hexane. The p-toluidine transferred from the inside to the water via the contact surface 27 and generated in the reaction microchannel 24 is immediately and easily stabilized while maintaining the same flow rate as that in the reaction microchannel 24. And can be separated and extracted from hexane.
In addition, since p-toluidine has higher solubility in acidic water than neutral, it is more effective to use water to which acetic acid is added.

  By precisely controlling the flow rate and the relative flow rate of the organic phase and the aqueous phase, the organic phase (reaction liquid using hexane as a solvent) is transferred from the first outlet groove 34 to the second outlet groove 35. The aqueous phase can be separated from the aqueous phase, and p-toluidine can be efficiently extracted in the aqueous phase.

(Example 5)
Next, a carboxylic acid production method for finally producing carboxylic acid from the carboxylic acid raw material through an oxidation reaction step using the photocatalytic microreactor 1 of Example 1 will be described.
The carboxylic acid production method according to this example is a carboxylic acid production method in which a carboxylic acid is finally produced from a carboxylic acid raw material through an oxidation reaction step, and at least a part of the oxidation reaction step is performed as in Example 1. This is performed using the photocatalytic microreactor 1.

  When toluene is used as a raw material for carboxylic acid, benzyl alcohol or benzaldehyde is produced from toluene in the photocatalytic microreactor 1 of this example. Benzoic acid can be obtained by further oxidizing the benzyl alcohol or benzaldehyde obtained by the reaction using the photocatalytic microreactor 1. The oxidation reaction from benzyl alcohol or benzaldehyde to benzoic acid can be performed by a known oxidation reaction. Further, in the photocatalytic microreaction apparatus 1 of the present embodiment, the benzaldehyde can be further oxidized to obtain benzoic acid by extending the microchannel and extending the residence time in the microchannel 4.

  Further, phthalic anhydride and phthalic acid can be produced by using xylene or naphthalene as a carboxylic acid raw material and undergoing an oxidation reaction step by a reaction using the photocatalytic microreactor 1 of this example. Moreover, adipic acid can be manufactured through the oxidation reaction process by reaction using the photocatalyst type | system | group microreactor 1 of a present Example, using cyclohexane as a carboxylic acid raw material. Moreover, maleic acid can be manufactured through the oxidation reaction process by reaction using the photocatalyst type | system | group microreactor 1 of a present Example, using benzene as a raw material for carboxylic acids.

The carboxylic acid production method for producing carboxylic acid finally from the carboxylic acid raw material through an oxidation reaction step is conventionally a large-scale reaction vessel using an oxidizing agent such as nitric acid, permanganate, and dichromate. It is done in Therefore, a large amount of oxidizing agent is provided.
According to the present embodiment, since at least a part of the multistage reaction is performed using the photocatalytic microreactor 1 of Embodiment 1, the amount of the oxidizing agent used is greatly reduced or eliminated. be able to.

(Example 6)
Using the photocatalytic microreactor according to the present invention, a photo-oxidation experiment of a terminal olefin of 1-decene using a pipe flow was performed.
The terminal olefin can be oxidized by a photocatalyst in an organic solvent. Formula (2) is an oxidation reaction of 1-decene.

  At that time, it is known that when an aprotic solvent such as n-hexane, nitromethane, acetonitrile, or n-butyronitrile is used, the catalytic activity varies greatly depending on the solvent. In this example, 1-decene was directly passed through the microchannel as an organic liquid material having a low affinity for the photocatalyst, and a pipe flow was formed using oxygen as the gas material. As a comparative example, an experiment was conducted in which 1 mM 1-decene was dissolved in n-butyronitrile (having an affinity for a photocatalyst) as an organic solution raw material (reaction solution).

[Reaction conditions]
Micro channel: width 500μm, depth 300μm
Photocatalyst: Titanium oxide (TiO ₂ ) [supported on bottom and side]
Light irradiation device: 450 mW UV-LED (365 nm)
Raw material feeding means: Syringe pump Reaction time: 70 seconds Thickness of liquid phase in pipe flow state: 20 μm

Under the above conditions, when 1-decene is used as an organic liquid raw material having a low affinity for the photocatalyst, 1-decene is converted to another compound (1,2-epoxydecane, with a conversion rate of 4.5%. Nonanal, and 2-decanone, etc.).
As a comparative example, when an organic solution raw material in which 1 mM 1-decene was dissolved in n-butyronitrile was circulated through the microchannel of the photocatalytic microreactor, the conversion rate of 1-decene in the organic solution raw material was 22%. Met.

Here, assuming that 1-decene (organic liquid raw material) or 1-decene-dissolved n-butyronitrile (organic solution raw material) was circulated through each 1 liter of microchannel, the amount of reacted 1-decene was In calculation, when 1-decene is used as an organic liquid raw material as it is (conversion rate of 4.5%), 0.24 mol of n-butyronitrile in which 1-decene is dissolved is used as an organic solution raw material (conversion rate). 22%) is 0.22 × 10 ⁻³ mol. That is, by using 1-decene as an organic liquid raw material as it is, the reaction can be carried out with about 1000 times higher efficiency.

  In the reaction using n-butyronitrile in which 1-decene is dissolved as an organic solution raw material, since the solvent n-butyronitrile has an affinity for the photocatalyst, a reaction by a batch-type macro reactor can also be performed. However, the reaction using 1-decene itself as an organic liquid raw material could not be carried out conventionally because 1-decene has a low affinity with the photocatalyst.

  By using the photocatalytic microreaction apparatus of the present invention, a reaction system having a high specific surface area with respect to 1-decene having a low affinity for the photocatalyst can be realized, and the oxidation reaction of 1-decene can be performed with high efficiency. It can be carried out.

  The present invention provides a photocatalytic reaction in which the reaction raw material is a gas raw material and an organic liquid raw material having a low affinity for the photocatalyst or an organic solution raw material in which the reaction raw material is dissolved in an organic solvent having a low affinity for the photocatalyst. Is effective as a photocatalytic microreactor capable of proceeding with high efficiency.

1 is a perspective view showing a first embodiment of a photocatalytic microreactor according to the present invention. It is sectional drawing which shows the 1st Example of the photocatalyst type | system | group micro reactor based on this invention. It is an enlarged view of the II cross section of the A section of FIG. 2, and is a figure which shows the pipe flow state in a microchannel. It is a figure which shows the II-II sectional drawing of FIG. FIG. 5 is a modified example of the microchannel in which the layer of the photocatalyst described with reference to FIG. 4 is formed. It is a figure which shows the experimental result using the photocatalyst type | system | group micro reactor of Example 1. FIG. It is a perspective view which shows the 3rd Example of the photocatalyst type | system | group micro reactor based on this invention. It is a principal part enlarged view of the micro flow path of the photocatalyst type | system | group micro reaction apparatus of FIG.

Explanation of symbols

1 photocatalytic microreactor, 2 substrate, 3 top plate, 4 microchannel,
5 photocatalyst layer, 6 groove, 8 light irradiation device (light irradiation means),
11 first supply port, 12 second supply port, 13 take-out port,
21 photocatalytic microreactor, 22 substrate, 23 top plate,
24 reaction microchannel, 25 photocatalyst layer, 26 extraction microchannel,
27 contact surface, 28 outlet,
41 first supply port, 42 second supply port, 43 third supply port,
44 1st outlet, 45 2nd outlet

Claims (13)

A microreactor made of a light transmissive material and having a microchannel through which reaction raw materials are circulated;
Raw material feeding means for feeding the reaction raw material into the microchannel;
A photocatalytic microreaction apparatus comprising a photocatalyst layer provided on the inner surface of the microchannel,
The reaction raw material, and gas material, for the case an organic material solution obtained by dissolving the reaction material in a hydrophobic organic liquid material or a hydrophobic organic solvent, the material feed means, said organic liquid material or said A photocatalytic microreaction apparatus configured to be capable of forming a pipe flow in which an organic solution raw material flows along an inner surface of the microchannel and the gas raw material flows through a central portion.   2. The photocatalytic microreactor according to claim 1, wherein the photocatalyst layer is provided on the entire inner surface of the microchannel. A microreactor made of a light transmissive material and having a microchannel through which reaction raw materials are circulated;
Raw material feeding means for feeding the reaction raw material into the microchannel;
A layer of photocatalyst provided on the inner surface of the microchannel;
A photoirradiation means for irradiating the photocatalyst layer with light, and a photocatalytic microreaction apparatus comprising:
The reaction raw material, and gas material, for the case an organic material solution obtained by dissolving the reaction material in a hydrophobic organic liquid material or a hydrophobic organic solvent, the material feed means, said organic liquid material or said A photocatalytic microreaction apparatus configured to be capable of forming a pipe flow in which an organic solution raw material flows along an inner surface of the microchannel and the gas raw material flows through a central portion.   4. The photocatalytic microreaction apparatus according to claim 3, wherein the photocatalyst layer is provided on the entire inner surface of the microchannel, and the light irradiation means is provided outside the microreactor. A photocatalytic microreactor.   5. The photocatalytic microreaction apparatus according to claim 3 or 4, wherein the light irradiation means includes a light emitting diode that mainly emits ultraviolet light of 200 nm to 400 nm as a light source.   6. The photocatalytic microreactor according to any one of claims 1 to 5, wherein the gaseous raw material is carbon dioxide.   The photocatalytic microreaction apparatus according to any one of claims 1 to 5, further comprising an extraction microchannel communicated with an outlet of the microchannel, wherein the extraction microchannel is a photocatalytic reaction. When the product is more hydrophilic than the reaction raw material, it is merged with an aqueous liquid and two layers of liquid are circulated in a laminar flow state with the contact surface of both liquids as a boundary to generate the photocatalytic reaction. A photocatalytic microreaction apparatus characterized in that a product can be transferred from the reaction raw material into the aqueous liquid through the contact surface. A microreactor made of a light transmissive material and having a microchannel through which reaction raw materials are circulated;
A feeding means for feeding the reaction raw material into the microchannel;
A photocatalytic microreaction apparatus comprising a photocatalyst layer provided on the inner surface of the microchannel,
Furthermore, the microchannel for extraction communicated with the outlet of the microchannel,
The reaction raw material is a hydrophobic organic liquid raw material or an organic solution raw material in which the reaction raw material is dissolved in a hydrophobic organic solvent, and the product of the photocatalytic reaction is more hydrophilic than the reaction raw material, The microchannel for extraction is joined with the aqueous liquid, and two layers of liquid are circulated in a laminar flow state with the contact surface of both the liquids as a boundary, and the reaction product passes from the reaction raw material through the contact surface. The photocatalytic microreactor is configured to be transferred into the aqueous liquid. A microreactor made of a light transmissive material and having a microchannel through which reaction raw materials are circulated;
A feeding means for feeding the reaction raw material into the microchannel;
A layer of photocatalyst provided on the inner surface of the microchannel;
A photoirradiation means for irradiating the photocatalyst layer with light, and a photocatalytic microreaction apparatus comprising:
Furthermore, the microchannel for extraction communicated with the outlet of the microchannel,
The reaction raw material is a hydrophobic organic liquid raw material or an organic solution raw material in which the reaction raw material is dissolved in a hydrophobic organic solvent, and the product of the photocatalytic reaction is more hydrophilic than the reaction raw material, The microchannel for extraction is joined with the aqueous liquid, and two layers of liquid are circulated in a laminar flow state with the contact surface of both the liquids as a boundary, and the reaction product passes from the reaction raw material through the contact surface. The photocatalytic microreactor is configured to be transferred into the aqueous liquid.   10. The photocatalytic microreactor according to claim 1, wherein the photocatalyst is titanium dioxide. 11. A carboxylic acid production method for finally producing a carboxylic acid from an carboxylic acid raw material through an oxidation reaction step,
A method for producing a carboxylic acid, wherein at least a part of the oxidation reaction step is performed using the photocatalytic microreactor according to claim 1 or 3. A microreactor made of a light transmissive material and having a microchannel through which reaction raw materials are circulated;
A feeding means for feeding the reaction raw material into the microchannel;
A photocatalytic reaction method performed using a photocatalytic microreaction apparatus comprising a photocatalytic layer provided on the inner surface of the microchannel,
From said feeding means, as a reaction raw material, the photocatalytic reaction method characterized by causing a reaction by feeding an organic material solution obtained by dissolving the reaction material in a hydrophobic organic liquid material or a hydrophobic organic solvent. A microreactor made of a light transmissive material and having a microchannel through which reaction raw materials are circulated;
A feeding means for feeding the reaction raw material into the microchannel;
A layer of photocatalyst provided on the inner surface of the microchannel;
A photocatalytic reaction method performed using a photocatalytic microreaction apparatus comprising a light irradiation means for irradiating light to the photocatalyst layer,
From said feeding means, as a reaction raw material, the photocatalytic reaction method characterized by causing a reaction by feeding an organic material solution obtained by dissolving the reaction material in a hydrophobic organic liquid material or a hydrophobic organic solvent.

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