JP5401692B2 - Micro reactor and reaction method - Google Patents

Description

  The present invention relates to a microreactor and a reaction method capable of generating singlet oxygen using porous silicon as a photosensitizer and performing an oxidation reaction with the singlet oxygen.

  When oxygen (triplet oxygen) existing in a normal state is excited, singlet oxygen having very high energy is obtained. This singlet oxygen is very reactive and is used in various chemical reactions. However, the transition from triplet oxygen in the ground state to a singlet state excited by light, for example, usually hardly occurs because of spin forbidden.

  Therefore, as a method for generating singlet oxygen from triplet oxygen, a method using microwave discharge, a method using low-temperature plasma, a photosensitization method using a photosensitizer, and the like are performed. In a chemical synthesis reaction, when a reaction using singlet oxygen is performed in a solution, a photosensitization method is generally used.

  As the photosensitizer, an organic dye compound such as rose bengal or methylene blue is used. When the reaction using singlet oxygen is performed in the solution as described above, the batch method is generally performed in which the photosensitizer dye is dispersed in the reaction solution in the reaction vessel.

  However, when the reaction is performed in the batch mode, it is difficult to irradiate the entire reaction vessel with sufficient light, and the use efficiency of light used for generating singlet oxygen by the photosensitizer is deteriorated. There was a problem.

  In addition, after performing the reaction using singlet oxygen in the solution, a step of removing the photosensitizer dispersed in the reaction solution is necessary to purify the target product. The product purification process becomes complicated. Furthermore, if oxygen and organic substances are mixed, there is a risk of explosion, and it is necessary to pay close attention to handling them.

  Here, in recent years, it has been reported that inorganic porous silicon has a function as a photosensitizer (Patent Document 1). The porous silicon can generate singlet oxygen more efficiently than the organic photosensitizer.

  Moreover, since the porous silicon can be formed in a cassette shape, for example, in addition to the powder form, it is easier to handle than the powder form, and supply or removal of the photosensitizer is easy. You can do it. However, when the reaction using singlet oxygen is performed in the batch mode, there still remains a problem that the entire reaction vessel cannot be irradiated with sufficient light.

International Patent Application Publication No. 2003/106583

  An object of the present invention is to provide a reaction apparatus and a reaction method capable of solving the above problems and performing a reaction using singlet oxygen safely and efficiently.

  In order to achieve the above object, a microreaction apparatus according to a first aspect of the present invention includes a reaction section having a microchannel, and a porous silicon layer provided on an inner surface of the microchannel, and the microstream Liquid feed means for feeding a raw material liquid in which oxygen is dissolved into the channel, and light irradiation means for irradiating light to the porous silicon layer of the microchannel.

  In the present invention, the “microchannel” refers to a reaction channel having a fine diameter of about several tens to several thousand μm. The “raw material liquid” includes a reactant-containing solution obtained by dissolving a reactant in a solvent, in addition to the case where the liquid itself is a reactant in a target reaction (reaction using singlet oxygen). According to this aspect, since the porous silicon layer is provided on the inner surface of the microchannel of the reaction section, the singlet oxygen is converted from the oxygen in the source liquid by flowing the source liquid in which oxygen is dissolved in the microchannel. And the singlet oxygen and the reactant in the raw material liquid can be reacted.

  In addition, by using the microchannel as a reaction field, the entire porous silicon layer provided on the inner surface of the microchannel can be uniformly irradiated with light, and the reaction molecules contained in the raw material liquid can be efficiently reacted. Can be made. That is, the efficiency with which singlet oxygen is generated from the oxygen in the raw material liquid is increased, and further, the efficiency with which the singlet oxygen reacts with the reactant in the raw material liquid is increased.

Moreover, since the porous silicon layer is provided in the microchannel, it is not necessary to remove the photosensitizer from the reaction solution (the raw material liquid in which the reaction has been performed). In addition, since the reaction field is a micro-channel, the temperature control is easy, and the risk of explosion in the reaction using organic substances is reduced. After the reaction solution passes through the microchannel, singlet oxygen disappears rapidly from the reaction solution, so that there is almost no explosive problem. Therefore, the reaction performed by generating singlet oxygen by the photosensitizer can be performed safely.
Furthermore, since porous silicon has a wide absorption in the visible light region, it can be used in a visible light responsive reaction system, and a reduction in photon cost is expected.

  A microreaction apparatus according to a second aspect of the present invention includes a reaction section having a microchannel, a porous silicon layer provided on the inner surface of the microchannel, and a liquid for feeding a raw material liquid into the microchannel A feeding unit; a gas feeding unit that feeds a gas containing oxygen as a component into the microchannel; and a light irradiation unit that irradiates light to the porous silicon layer of the microchannel.

  In the microreaction apparatus according to this aspect, the raw material liquid is fed into the microchannel by the liquid feeding means, and a gas containing oxygen as a constituent component (hereinafter sometimes simply referred to as “gas”) is fed by the gas feeding means. It is a configuration. As a result, the raw material liquid can be circulated in a state where oxygen is dissolved in the microchannel, and thus the same effect as the first aspect can be obtained. In addition, oxygen consumed by the reaction that occurs in the microchannel can always be supplied into the raw material liquid.

  As the gas containing oxygen as a constituent component, pure oxygen can be used as well as a gas containing oxygen as a part of the constituent component of the gas, for example, the atmosphere. The oxygen concentration in the gas is preferably high, and it is more preferable to use pure oxygen.

  The flow rate of the raw material liquid and the gas fed into the microchannel by the liquid feeding means and the gas feeding means is a slag flow in a state where the raw material liquid and the gas are alternately circulated in the microchannel [FIG. )] Or a pipe flow [see FIG. 11B] in which the raw material liquid flows along the inner surface of the microchannel and the gas flows through the center of the microchannel. It is desirable to adjust so that.

A microreaction apparatus according to a third aspect of the present invention is characterized in that, in the first aspect, an oxygen dissolving means for dissolving oxygen in the raw material liquid is provided.
According to this aspect, oxygen can be reliably dissolved in the raw material liquid and sent to the microchannel, and sufficient oxygen can be supplied into the raw material liquid to perform a reaction using singlet oxygen. It is desirable that the raw material liquid is saturated with oxygen by the oxygen dissolving means and fed into the microchannel.

  The microreaction apparatus according to a fourth aspect of the present invention is the microreaction apparatus according to any one of the first to third aspects, wherein the reaction portion is formed with a slit-like groove penetrating a plate-like plane. A flow path forming portion, a first substrate bonded to one surface side of the flow path forming portion, and a second substrate bonded to the other surface side of the flow path forming portion, A porous silicon layer formed in a plate shape between one surface of the flow path forming portion and the first substrate and / or between the other surface of the flow path forming portion and the second substrate. The first substrate, the flow path forming portion, and the second substrate are bonded together with the first substrate or the porous silicon layer on the first substrate side, and the second substrate or the first substrate being inserted. The micro-channel is formed by the porous silicon layer on the two-plate side and the inner surface of the groove of the channel-forming part. It is characterized in that there.

  The micro flow path is formed by sandwiching a flow path forming portion formed by a slit-like groove penetrating in a plate-like plane between a first substrate and a second substrate. At this time, a porous plate formed between the first substrate and one surface of the flow path forming portion, or between the second substrate and the other surface of the flow path forming portion, or both. Insert the silicon layer. As a result, it is possible to form a microchannel having a porous silicon layer on the upper surface, the lower surface, or the upper and lower surfaces of the channel forming portion. As a result, it is possible to form a reaction part having a microchannel provided with a porous silicon layer with a simple structure, and to obtain the same effect as any one of the first to third aspects. Can do.

  A microreaction apparatus according to a fifth aspect of the present invention is characterized in that, in any one of the first to fourth aspects, a temperature adjustment means for adjusting the temperature of the reaction section is provided. Is.

  According to this aspect, the temperature of the reaction part can be adjusted to a temperature suitable for the reaction using singlet oxygen performed in the microchannel.

    A reaction method according to a sixth aspect of the present invention is characterized in that singlet oxygen is generated in a porous silicon layer in a micro-channel irradiated with light, and the generated singlet oxygen and a raw material liquid are reacted. To do.

  According to this aspect, it is possible to efficiently generate singlet oxygen from oxygen by uniformly irradiating light to the porous silicon layer in the microchannel, and the singlet oxygen that occurs after the generation of the singlet oxygen and The reaction with the raw material liquid can be efficiently performed in the microchannel.

  Since the microchannel is fine, temperature control is easy, and the risk of explosion in a reaction using an organic substance can be reduced. In addition, after the reaction solution passes through the microchannel, singlet oxygen disappears quickly from the reaction solution, so that there is almost no explosive problem. Therefore, the reaction performed by generating singlet oxygen can be performed safely.

  Further, since porous silicon has a wide absorption in the visible light region, a visible light responsive reaction can be performed. By using the microchannel, light can be used efficiently, and by using natural light such as sunlight as a light source, singlet oxygen can be generated with a low photon cost.

  According to the present invention, singlet oxygen can be generated in a solution, and a reaction performed using singlet oxygen can be performed safely and efficiently.

FIG. 3 is an exploded perspective view illustrating an example of a first substrate, a flow path forming unit, a porous silicon layer, and a second substrate that constitute a reaction unit of the microreaction apparatus according to the first embodiment. FIG. 2 is a perspective view of a microreaction apparatus having a reaction part formed by joining the first substrate, the flow path forming part, the porous silicon layer, and the second substrate of FIG. 1. FIG. 3 is an XX arrow view of the microreaction apparatus of FIG. 2. 6 is a side sectional view showing another example of the microreaction apparatus according to Example 2. FIG. 6 is a plan view of a flow path forming part of a microreaction apparatus according to Example 3. FIG. It is a disassembled perspective view which shows an example of the 1st board | substrate which comprises the reaction part of the micro reaction apparatus concerning Example 4, a flow-path formation part, a porous silicon layer, and a 2nd board | substrate. FIG. 7 is a perspective view of a microreaction apparatus having a reaction portion formed by joining the first substrate, the flow path forming portion, the porous silicon layer, and the second substrate of FIG. 6. It is a figure which shows the example of a flow-path formation part, (A) is an example of the flow-path formation part by which the slit-shaped through-hole was provided in the plate, (B) is a slit which arrange | positions several plates. It is an example of the flow-path formation part which forms a groove | channel, (C) is a flow-path formation part provided with the Y-shaped structure. FIG. 9 is an exploded perspective view of a first substrate, a flow path forming unit, a porous silicon layer, and a second substrate that constitute a reaction unit of a microreaction apparatus according to Example 5. FIG. 10 is a perspective view of a microreaction apparatus having a reaction part formed by joining the first substrate, the flow path forming part, the porous silicon layer, and the second substrate of FIG. 9. It is a figure explaining a slag flow (A) and a pipe flow (B). When the raw material liquid saturated with oxygen is circulated through the micro flow path (black circle in the figure), and when the raw material liquid and oxygen are sent to the micro flow path to form a slag flow (circular in the figure) It is an experimental result of a white square).

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail based on an Example, this invention is not limited to these Examples.

[Example 1]
FIG. 1 is an exploded perspective view illustrating an example of a first substrate 3, a flow path forming unit 4, a porous silicon layer 5, and a second substrate 6 constituting the reaction unit 2 of the microreaction apparatus 1 according to the first embodiment. . FIG. 2 is a perspective view of a microreaction apparatus 1 having a reaction portion 2 formed by bonding the first substrate 3, the flow path forming portion 4, the porous silicon layer 5, and the second substrate 6 of FIG. 1. FIG. 3 is an XX arrow view of the microreaction apparatus 1 of FIG.

  The reaction section 2 of the microreaction apparatus 1 according to the present embodiment is a flow path formed by forming a slit-like groove 7 penetrating a plate-like plate plane as shown in FIGS. 1 and 8A. The microchannel 8 is formed by sandwiching the upper and lower portions of the portion 4 with other plate-like bodies such as a first substrate 3, a second substrate 6, or a porous silicon layer 5 described later.

  The reaction section 2 has a first substrate 3 disposed on the upper surface of the flow path forming section 4, a porous silicon layer 5 formed in a plate shape is disposed on the lower surface of the flow path forming section 4, and The second substrate 6 is disposed on the lower surface, and these are joined together. That is, as shown in FIG. 3, the microchannel 8 is formed by the first substrate 3, the porous silicon layer 5, and the inner surface 9 of the groove 7 of the channel formation portion 4.

  The porous silicon layer 5 is made of porous silicon that can act as a photosensitizer and generate singlet oxygen. The porous silicon is preferably one that can generate singlet oxygen by light energy having a wavelength of 300 nm to 800 nm. It has been reported that singlet oxygen can be efficiently generated when the size of the silicon nanocrystal constituting the porous silicon is about 2.5 nm (emission peak energy is about 1.63 eV) (Patent Document). 1: International Patent Application Publication No. 2003/106583).

  By flowing a raw material liquid in which oxygen is dissolved in the micro flow path 8 provided with the porous silicon layer 5 having such properties, singlet oxygen can be efficiently generated in the raw material liquid. Further, the generated singlet oxygen can be reacted with the reactant in the raw material liquid (including the case where the raw material liquid itself is a reactive substance). The reaction performed in the microchannel 8 will be described in detail in Example 5 described later.

  The first substrate 3 is provided with a raw material liquid supply port 10 and a reaction solution discharge port 11. The raw material liquid supply port 10 can feed a raw material liquid in which oxygen is dissolved into the microchannel 8. It is connected to the liquid feeding means 13 provided with a proper pump or the like. A raw material liquid is supplied from the raw material liquid supply port 10 to the micro flow path 8, and a reaction using singlet oxygen is performed in the raw material liquid while flowing through the micro flow path 8, and the reaction solution is discharged from the reaction solution. It is discharged from the outlet 11. Either one or both of the raw material liquid supply port 10 and the reaction solution discharge port 11 may be provided on the second substrate 6.

  As the raw material liquid in which oxygen is dissolved, it is possible to use a raw material liquid in which oxygen in an amount corresponding to the partial pressure of oxygen in the atmosphere is used, but the oxygen dissolving means 14 is provided upstream of the liquid feeding means 13. It is desirable to provide such a configuration that sufficient oxygen can be dissolved in the raw material liquid and sent to the microchannel 8. As the oxygen dissolving means 14, for example, a bubbling device that blows oxygen gas into the raw material liquid can be used.

  Further, the microreaction apparatus 1 includes light irradiation means 12 for irradiating light to the porous silicon layer 5 forming the microchannel 8. In FIG. 2, in order to irradiate the porous silicon layer 5 provided between the flow path forming portion 4 and the second substrate 6, the light is irradiated from the first substrate 3 side toward the micro flow path 8. Is configured to do. In addition, as the light irradiation means 12, an artificial light source such as an LED can be used, and when used in a visible light responsive reaction system, sunlight can be used as a light source. .

  The flow path forming portion 4, the first substrate 3 and the second substrate 6 are formed of a transparent plate material having high light transmittance into the micro flow path 8, for example, a material such as quartz, borosilicate glass, acrylic or the like. It is preferable to use a processed plate material.

  The first substrate 3, the flow path forming portion 4, the porous silicon layer 5, and the second substrate 6 are bonded and bonded with, for example, an adhesive. Moreover, a hole can be made in the edge part along the corner | angular part and edge | side of each plate, and it can also press and join with a volt | bolt and a nut.

Moreover, each plate can be adhere | attached using an adhesive resin film. As an adhesive resin film, what has the self-adhesive property by normal temperature or a heating is preferable, for example, a fluororesin, an epoxy resin, a silicone resin etc. are mentioned.
In addition, it is also possible to form the said flow-path formation part 4 with the said adhesive resin film which has the self-adhesive property by the said normal temperature or a heating. The adhesive resin film is easier to form slit-like grooves than hard materials such as quartz and borosilicate glass, and the flow path forming portion 4 itself is used as an adhesive to join other plates. Therefore, the microreaction apparatus 1 can be produced at a low cost.

  The micro flow path 8 formed by the first substrate 3, the porous silicon layer 5, and the inner surface 9 of the groove 7 of the flow path forming portion 4 has a width of 50 to 1000 μm and a depth of 10 μm to 1000 μm. preferable. In particular, it is preferable that the Reynolds number is set to about several tens to 1,000 or less with respect to the fluid flowing through the microchannel, and the flow is designed so as to maintain the laminar flow.

  The length of the microchannel 8 is set according to a predetermined reaction time necessary for the reaction of the reactant in the raw material liquid. That is, the raw material liquid is set so as to pass through the microchannel 8 over the predetermined reaction time.

  Further, the reaction unit 2 may be provided with a temperature adjusting unit 15 for adjusting the temperature of the reaction unit 2 so that the reaction unit 2 can be adjusted to a temperature suitable for the reaction using singlet oxygen performed in the microchannel 8. desirable.

  The structure of the micro flow path 8 is not limited to the above-described structure, and as long as the micro flow path 8 of the reactor 2 can be irradiated with light, The cross-sectional shape, the number of microchannels 8 and the like can be changed as appropriate. Moreover, about the thing provided with the some micro flow path 8, a flow path diameter and a cross-sectional shape can be changed for every micro flow path.

  According to the present embodiment, the porous silicon layer 5 can be provided on the inner surface of the microchannel 8 of the reaction unit 2 with a simple configuration, and the raw material liquid containing oxygen is allowed to flow through the microchannel 8. Singlet oxygen can be generated in the liquid, and the reaction using the singlet oxygen can be performed.

  By using the microchannel 8 as a reaction field, the entire porous silicon layer 5 provided on the inner surface of the microchannel 8 can be uniformly irradiated with light, and the reaction molecules contained in the raw material liquid can be efficiently irradiated. Can be reacted. That is, the efficiency with which singlet oxygen is generated from the oxygen in the raw material liquid is increased, and further, the efficiency with which the singlet oxygen reacts with the reactant in the raw material liquid is increased.

  In addition, since the porous silicon layer 5 is provided in the microchannel 8, no step of removing the photosensitizer from the reaction solution is required. In addition, since the reaction field is the micro flow path 8, the temperature control is easy, and the risk of explosion in the reaction using organic substances is reduced. After the reaction solution has passed through the microchannel 8, singlet oxygen disappears rapidly from the reaction solution, so that there is almost no explosive problem. Therefore, the reaction performed by generating singlet oxygen by the photosensitizer can be performed safely.

[Example 2]
In the first embodiment, the porous silicon layer 5 is provided between the flow path forming portion 4 and the second substrate 6 (see FIG. 3). However, as shown in FIG. A porous silicon layer 5 may be sandwiched between the first substrate 3 and the first substrate 3, and the porous silicon layer 5 may be disposed on both upper and lower surfaces.

  When the porous silicon layers 5 are provided on the upper and lower surfaces, it is desirable that the porous silicon layers 5 be formed thin enough to transmit light. Or you may comprise so that light may reach | attain by providing a slit, a micro hole, etc. in the porous silicon layer 5. FIG. At that time, in order to uniformly irradiate light on both surfaces of the porous silicon layer 5 on the first substrate 3 side and the second substrate 6 side, the light irradiation means 12 is provided on both sides of the first substrate 3 side and the second substrate 6 side. be able to.

  According to this example, in addition to the same effects as the microreactor of Example 1, the contact efficiency between the porous silicon layer and the liquid material in the microchannel can be increased, so that singlet oxygen is highly efficient. Can be generated.

[Example 3]
Next, another embodiment of the microreaction apparatus according to the present invention will be described. In the present embodiment, a flow path forming unit 50 formed by arranging a plurality of micro flow paths 51 in parallel is used. FIG. 5 is a plan view of the flow path forming unit 50 of the microreaction apparatus according to the present embodiment.

  The plurality of micro flow paths 51 of the flow path forming unit 50 are formed so as to merge with a common liquid supply flow path 52 and a common liquid discharge flow path 53. In order to uniformly supply the raw material liquid to the plurality of micro flow channels 51, the liquid supply flow channel 52 includes a wide flow channel portion 54, and the liquid discharge flow channel 53 includes a wide flow channel portion 55.

  According to the present embodiment, in addition to the same effects as the microreaction apparatus of the first embodiment, by introducing the raw material liquid into one common liquid supply channel 52, the raw material liquid can be converted into a plurality of microreaction flows. Since it is sent to the channel 51, a large capacity reaction can be performed. Furthermore, since the reaction solutions discharged from each micro flow channel 51 are merged again and discharged from one liquid discharge flow channel 53, the recovery thereof is easy.

[Example 4]
The present embodiment is an example of a microreactor provided with a liquid feed means 33 for feeding a raw material liquid into a microchannel and a gas feed means 34 for feeding a gas containing oxygen as a constituent component into the microchannel.

  FIG. 6 is an exploded perspective view illustrating an example of the first substrate 23, the flow path forming unit 24, the porous silicon layer 25, and the second substrate 26 that constitute the reaction unit 22 of the microreaction apparatus 21 according to the fourth embodiment. . FIG. 7 is a perspective view of a microreaction apparatus 21 having a reaction part 22 formed by joining the first substrate 23, the flow path forming part 24, the porous silicon layer 25, and the second substrate 26 of FIG.

  In this embodiment, as shown in FIG. 6, a flow path forming portion 24 in which a Y-shaped slit-like groove 27 (through hole) is provided on a plate-like plate is used. One of the forked portions forming the Y-shape is used as a flow channel connected to the raw material liquid supply port 30 for feeding the raw material liquid, and the other of the forked portions is used as a flow channel connected to the gas supply port 32 for feeding a gas containing oxygen as a constituent Used.

  The first substrate 23 is provided with a raw material liquid supply port 30, a gas supply port 32, and a reaction solution discharge port 31. The raw material liquid supply port 30 is connected to a liquid feeding means 33 having a pump or the like capable of feeding the raw material liquid into the microchannel 28. The gas supply port 32 is connected to a gas feeding means 34 having a pump or the like that can feed the gas containing oxygen into the microchannel 28. The raw material liquid supply port 30, the gas supply port 32, and the reaction solution discharge port 31 can be provided on the second substrate 26.

  In the microreactor 21 according to this embodiment, the liquid feed means 33 feeds the raw material liquid from the raw material liquid supply port 30 to the microchannel 28, and the gas feed means 34 gas containing oxygen from the gas supply port 32. And the raw material liquid and the gas are united in the micro flow path 28 to circulate through the micro flow path 28. As a result, the raw material liquid can be circulated in a state where oxygen is dissolved in the microchannel 28, and thus the same effect as the microreaction apparatus 1 described in Example 1 can be obtained. . In addition, the oxygen consumed by the reaction occurring in the microchannel 28 can be continuously supplied into the raw material liquid.

  As the gas containing oxygen, pure oxygen can be used as well as a gas containing oxygen as a part of its constituent components, such as the atmosphere. The oxygen concentration in the gas is preferably high, and it is more preferable to use pure oxygen.

  Further, the flow rates of the raw material liquid and the gas fed into the micro flow path 28 by the liquid feeding means 33 and the gas feeding means 34 are the same as that of the raw material liquid (L in the figure) and the gas (same as in FIG. 11A). G) and the slag flow in a state of alternately flowing in the micro flow channel (MC), or the raw material liquid (L) flows along the inner surface of the micro flow channel (MC) as shown in FIG. It is desirable to adjust so that the gas (G) can form a pipe flow that flows through the center of the microchannel. By forming the slag flow or pipe flow and circulating the raw material liquid and the gas through the micro flow path 28, the singlet oxygen generation efficiency and the reaction between the generated singlet oxygen and the reactants in the raw material liquid Efficiency can be further increased.

[Example 5]
Another example of the microreaction apparatus according to the present invention will be described. FIG. 9 is an exploded perspective view of the first substrate 43, the flow path forming unit 44, the porous silicon layer 45, and the second substrate 46 that constitute the reaction unit 42 of the microreaction apparatus 41 according to the fifth embodiment. FIG. 10 is a perspective view of a microreactor 41 having a reaction part 42 formed by joining the first substrate 43, the flow path forming part 44, the porous silicon layer 45, and the second substrate 46 of FIG.

  In the microreactor 41 according to the present embodiment, a flow path forming portion in which a through-hole having a narrow slit shape is provided in a plate as in the first, second, and fourth embodiments [for example, FIG. Instead, the micro channel 48 is formed by the channel forming part 44 in which a plurality of plates are arranged to form a slit-like groove as shown in FIG. 8B.

  The flow path forming portion 44 in the present embodiment can be formed by arranging, for example, a cut resin plate, an adhesive resin film, and the like, and the groove forming the micro flow path can be provided with ease of processing. It is also suitable for simple production of a room level microreactor. As shown in FIG. 8B, the straight microchannels 48 can be formed by aligning the sides of the two plate-like bodies in parallel.

  In this embodiment, as shown in FIG. 10, an opening is formed on the side surface of the reaction portion 42 formed by joining the first substrate 43, the flow path forming portion 44, the porous silicon layer 45, and the second substrate 46. The Since this opening can be used as the raw material inlet and the reaction solution outlet in the first embodiment, the first substrate 43 or the second substrate 35 is not provided with holes as the raw material inlet and the reaction solution outlet. be able to.

  Further, by cutting an acrylic plate or the like into a shape as shown in FIG. 8C, a Y-shaped groove 57 can be formed. By using the flow path forming portion 54 of FIG. 8C, a micro flow path capable of bringing together a raw material liquid and a gas containing oxygen in the micro flow path and flowing in the same manner as in the fourth embodiment. Can be formed.

  According to this example, a microreaction apparatus can be easily produced at low cost, and the same effects as those of the microreaction apparatus according to Example 1 or Example 2 can be obtained.

[Example 6]
Next, a reaction method performed using the microreaction apparatus according to the present invention will be described using the microreaction apparatus 1 of Example 1. This reaction method is performed by generating singlet oxygen in the porous silicon layer 5 in the microchannel 8 irradiated with light, and reacting the generated singlet oxygen with the raw material liquid.

When a raw material liquid in which oxygen is dissolved is supplied to the micro flow path 8 and light is irradiated to the micro flow path 8, it is dissolved in the raw material liquid by the action of the porous silicon layer 5 provided in the micro flow path 8. Oxygen is excited to produce singlet oxygen. The singlet oxygen produced in the raw material liquid reacts with the reactants in the raw material liquid to produce the target product.
As the raw material liquid, in addition to the case where the liquid itself is a reactant for the target reaction (reaction using singlet oxygen), a reactant-containing solution in which the reactant is dissolved in a solvent can be used.

  By using the microreaction apparatus 1 according to the present invention, the porous silicon layer 5 in the microchannel 8 can be uniformly irradiated with light, so that singlet oxygen can be efficiently generated from oxygen, and The subsequent reaction between the singlet oxygen and the raw material liquid that occurs after the generation of singlet oxygen can also be performed with high efficiency.

  In addition, since the micro flow path 8 is fine, temperature control is easy, and the risk of explosion in a reaction using an organic substance can be reduced. Further, after the reaction solution passes through the micro flow path 8, singlet oxygen disappears rapidly from the reaction solution, so that there is almost no explosive problem. Therefore, the reaction performed by generating singlet oxygen can be performed safely.

  Further, since porous silicon has a wide absorption in the visible light region, a visible light responsive reaction can be performed. By using the microchannel 8, light can be used efficiently, and by using natural light such as sunlight as a light source, singlet oxygen can be generated with low photon cost.

  Hereinafter, the reaction using singlet oxygen that can be performed by the method according to this example will be described with reference to specific examples. Singlet oxygen is thought to act on organic compounds with double bonds, causing the reactions described below.

<First reaction step>
One mole of singlet oxygen molecules selectively reacts with two equivalents of double bonds of an organic compound that is an object to be oxidized, that is, π electrons of each π electron bond (2 equivalents). The oxidation reaction by singlet oxygen molecules takes place in such a way that each two equivalents of oxygen atoms deprive the π electrons of one end of each of the two equivalents of double bonds, and each of the two equivalents of double bonds is single-ended. Combine (2 equivalents). The π electrons of the π electron bonds at the opposite ends of the respective double bonds form adjacent single bonds as double bonds. That is, the double bond can be moved to the adjacent portion.

  Further, after the first reaction step, 1 mol (2 equivalents) of oxygen atoms of the singlet oxygen molecules are added to the object to be oxidized by the second reaction step described later. There are several patterns of oxygen atom addition that occur in the second reaction step. Examples thereof (Pattern 1 to Pattern 3) are shown below.

<Second reaction step>
(Pattern 1) When an epidioxy (—O—O—) crosslink is attached to the object to be oxidized (Pattern 2), oxygen atoms are separated, and hydrogen atoms repelled from the object to be oxidized in the first reaction are taken in, When attached to an object to be oxidized by forming a hydroxyl group (—OH) (Pattern 3) When oxygen atoms are separated and attached to the object to be oxidized with a double bond (═O).

Examples of reactions of the patterns 1 to 3 are shown below.
(Example of reaction of pattern 1) Oxidation of α-terpinene

(Example of reaction of pattern 2) Oxidation of 3,7-dimethyl-6-octen-1-ol

(Example of reaction of pattern 3) Oxidation of 1,5-naphthalenediol

  Reactions such as Reaction Example 1 to Reaction Example 3 can be used for synthesis reactions of high value-added compounds such as pharmaceuticals and fragrances. At present, such a synthesis reaction is performed by a method using an organic photosensitizer such as rose bengal (there is an explosive problem and a step of removing the photosensitizer after synthesis is necessary). By using the reaction using the microreaction apparatus according to the invention, the synthesis reaction can be performed safely and efficiently. In addition, since porous silicon has a wide absorption in the visible light region, the synthesis reaction of the high value-added compound can be made into a solar system.

  The reaction performed using the microreaction apparatus according to the present invention is not limited to the above reaction pattern, and is not particularly limited as long as it is a reaction system performed by generating singlet oxygen in a solution.

[Oxidation of α-terpinene]
The oxidation reaction of α-terpinene, which is the reaction example of Pattern 1 described in Example 6, was performed using the microreaction apparatus according to the present invention. FIG. 12 shows the case where the raw material liquid saturated with oxygen is circulated through the micro flow channel (black circle in the figure), and the case where the raw material liquid and oxygen are sent to the micro flow channel to form a slag flow. It is an experimental result (in the figure, a white square). Here, the relative concentration taken on the vertical axis of the graph of FIG. 12 indicates that the product concentration at the irradiation time of 12 seconds in the experiment conducted by forming the slag flow is 1, and other experimental values (each irradiation time). Product concentration) at a relative value.

  When the raw material liquid and oxygen gas are sent to the microchannel and the reaction is performed by forming a slag flow, the reaction rate is about 6 times faster than when the raw material liquid saturated with oxygen is circulated through the microchannel. became. By forming the slag flow, the contact area between the oxygen gas and the raw material liquid is increased, and the contact frequency between the singlet oxygen generated in the microchannel and the reactants in the raw material liquid is increased. It is thought that it can be made to progress.

  Further, when the slag flow is formed, as shown in FIG. 11, a secondary flow 29 is generated in each liquid portion L partitioned by gas in the micro flow channel 28, and the micro flow channel 28 is stirred while the raw material solution is stirred. It is thought that it circulates inside. It is presumed that the reaction efficiency is also enhanced by this.

  INDUSTRIAL APPLICABILITY The present invention can be used for a microreaction apparatus used for a reaction system that generates singlet oxygen and uses the singlet oxygen. Further, the present invention can be used in a reaction method in which singlet oxygen is generated in a microchannel and performed using the singlet oxygen.

1 microreactor, 2 reaction section, 3 first substrate, 4 flow path forming section,
5 porous silicon layer, 6 second substrate,
7 groove, 8 micro flow path, 9 inner surface of groove,
10 Raw material liquid supply port, 11 Reaction solution discharge port, 12 Light irradiation part,
13 liquid feeding means, 14 oxygen dissolving means, 15 temperature adjusting means, 21 microreactor, 22 reaction section, 23 first substrate,
24 channel forming part, 25 porous silicon layer, 26 second substrate,
27 grooves, 28 microchannels, 29 secondary flow,
30 Raw material liquid supply port, 31 Reaction solution discharge port, 32 Gas supply port,
33 liquid feeding means, 34 gas feeding means,
41 microreactor, 42 reaction section, 43 first substrate,
44 channel forming part, 45 porous silicon layer, 46 second substrate,
47 grooves, 48 microchannels,
50 channel forming part, 51 micro channel, 52 liquid supply channel,
53 Liquid discharge channel, 54 Wide channel unit, 55 Wide channel unit L Raw material liquid, G gas, MC Micro channel

Claims (5)

A reaction section having a microchannel, and a porous silicon layer provided on the inner surface of the microchannel;
Liquid feeding means for feeding a raw material liquid in which oxygen is dissolved into the microchannel;
A light irradiation means for irradiating light to the porous silicon layer of the microchannel, and a microreaction apparatus comprising :
The reaction part is a flow path forming part in which a slit-like groove penetrating a plate-like plane is formed, and
A first substrate bonded to one surface side of the flow path forming portion;
A second substrate joined to the other surface side of the flow path forming part,
A porous silicon layer formed in a plate shape between one surface of the flow path forming portion and the first substrate and / or between the other surface of the flow path forming portion and the second substrate. Is inserted, the first substrate, the flow path forming portion and the second substrate are joined,
The microchannel is formed by the porous silicon layer on the first substrate or the first substrate side, the porous silicon layer on the second substrate or the second plate side, and the inner surface of the groove of the channel forming portion. A micro-reaction apparatus characterized by being made . A reaction section having a microchannel, and a porous silicon layer provided on the inner surface of the microchannel;
Liquid feeding means for feeding the raw material liquid into the microchannel;
Gas feeding means for feeding a gas containing oxygen as a component into the microchannel;
A light irradiation means for irradiating light to the porous silicon layer of the microchannel, and a microreaction apparatus comprising :
The reaction part is a flow path forming part in which a slit-like groove penetrating a plate-like plane is formed, and
A first substrate bonded to one surface side of the flow path forming portion;
A second substrate joined to the other surface side of the flow path forming part,
A porous silicon layer formed in a plate shape between one surface of the flow path forming portion and the first substrate and / or between the other surface of the flow path forming portion and the second substrate. Is inserted, the first substrate, the flow path forming portion and the second substrate are joined,
The microchannel is formed by the porous silicon layer on the first substrate or the first substrate side, the porous silicon layer on the second substrate or the second plate side, and the inner surface of the groove of the channel forming portion. A micro-reaction apparatus characterized by being made .   2. The microreactor according to claim 1, further comprising oxygen dissolving means for dissolving oxygen in the raw material liquid. The microreaction apparatus according to any one of claims 1 to 3 , further comprising temperature adjusting means for adjusting the temperature of the reaction section. Using the reaction apparatus according to any one of claims 1 to 4, singlet oxygen is generated in a porous silicon layer in a micro-channel irradiated with light, and the generated singlet oxygen and a raw material liquid A reaction method characterized by reacting

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