Chemical reaction apparatus

A chemical reaction apparatus includes: a horizontal flow-type reactor inside of which has been partitioned into multiple chambers by multiple partition plates, and a liquid content horizontally flows with an unfilled space being provided thereabove; a microwave generator that generates microwaves; and at least one waveguide that transmits the microwaves generated by the microwave generator to the unfilled space in the reactor. The content flows over each of the partition plates, and, in each chamber, a weir height on an inlet side is higher than a weir height on an outlet side by at least an overflow depth at the partition plate on the outlet side.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a U.S. national phase application under 35 U.S.C. §371 of International Patent Application No. PCT/JP2012/079152 filed on Nov. 9, 2012, and claims benefit of priority to Japanese Patent Application No. JP 2011-247954 filed on Nov. 11, 2011. The International Application was published on May 16, 2013, as International Publication No. WO 2013/069778 under PCT Article 21(2). The entire contents of these applications are hereby incorporated by reference.

TECHNICAL FIELD

The present invention relates to a chemical reaction apparatus for irradiating microwaves in a reactor.

BACKGROUND ART

Conventionally, chemical reaction apparatuses and chemical reaction methods are known that perform heat treatment and the like by irradiating a reaction material with microwaves (electromagnetic waves) (see Patent Document 1, for example).

CITATION LIST

Patent Document

SUMMARY OF INVENTION

Technical Problem

In such conventional chemical reaction apparatuses, there has been a demand for preventing an unreacted content from being discharged.

The present invention was arrived at in view of these circumstances, and it is an object thereof to provide a chemical reaction apparatus capable of preventing an unreacted content from being discharged, by preventing the content from flowing in a shortcut in a horizontal flow-type reactor.

Solution to Problem

In order to achieve the above-described object, the present invention is directed to a chemical reaction apparatus, including: a horizontal flow-type reactor inside of which has been partitioned into multiple chambers by multiple partition plates, and a liquid content horizontally flows with an unfilled space being provided thereabove; a microwave generator that generates microwaves; and at least one waveguide that transmits the microwaves generated by the microwave generator to the unfilled space in the reactor; wherein the content flows over each of the partition plates, and in each of the chambers, a weir height on an inlet side is higher than a weir height on an outlet side by at least an overflow depth at the partition plate on the outlet side.

With this configuration, at least some of overflows at the respective partition plates do not have the same height. Accordingly, the overflows can be prevented from being directly connected, and a content can be prevented from flowing in a shortcut. As a result, an unreacted content can be prevented from being discharged.

Furthermore, the chemical reaction apparatus of the present invention may be such that the weir heights of the partition plates in the reactor are the same in a state where the reactor is not inclined, and, when the content flows, the reactor is inclined such that, in each of the chambers, the weir height on the inlet side is higher than the weir height on the outlet side by at least the overflow depth at the partition plate on the outlet side.

With this configuration, even in the case where the partition plates have the same weir height, a content can be prevented from flowing in a shortcut by making the reactor inclined.

Furthermore, the chemical reaction apparatus of the present invention may be such that the flow paths have the same shape and are provided in the same number at all of the multiple partition plates, an angle of the inclination is at least θ that is calculated as: θ=sin−1(H/L) (where L is a shortest length of lengths, in a length direction of the reactor, of the respective chambers, and H is an overflow depth obtained using the following equation:
15eQ=√{square root over (2g)}CN{4(b−a)H5/2+10aeH3/2}

where Q is a flow rate, a is a width of a bottom of a trapezoidal flow path, b is a width of an upper side of the trapezoidal flow path, e is a height from the bottom to the upper side of the trapezoidal flow path, C is a flow coefficient, N is a number of the trapezoidal flow paths formed at one partition plate, and g is an acceleration of gravity).

With this configuration, the inclination angle of the reactor can be calculated by determining the flow rate and the shape of the flow path at the partition plates. A content can be prevented from flowing in a shortcut by making the reactor inclined according to this inclination angle.

Furthermore, the chemical reaction apparatus of the present invention may be such that the reactor is not inclined, and, in each of the chambers, a height of a bottom of a flow path at the partition plate on an inlet side is higher than a height of a bottom of a flow path at the partition plate on an outlet side by at least an overflow depth at the partition plate on the outlet side.

With this configuration, even in the case where the reactor is not inclined, a content can be prevented from flowing in a shortcut by setting as appropriate the heights of the flow paths at the partition plates.

Furthermore, the chemical reaction apparatus of the present invention may be such that the overflow depth is H that is calculated using the following equation:
15eQ=√{square root over (2g)}CN{4(b−a)H5/2+10aeH3/2}

(where Q is a flow rate, a is a width of a bottom of a trapezoidal flow path, b is a width of an upper side of the trapezoidal flow path, e is a height from the bottom to the upper side of the trapezoidal flow path, C is a flow coefficient, N is a number of the trapezoidal flow paths formed at one partition plate, and g is an acceleration of gravity).

With this configuration, the overflow depth can be calculated by determining the flow rate and the shape of the flow path at the partition plates, and a difference in the height of the bottom of the flow path between adjacent partition plates can be seen. A content can be prevented from flowing in a shortcut by forming the flow paths at the partition plates according to the difference in the height of the bottom of the flow path between the partition plates.

Furthermore, the chemical reaction apparatus of the present invention may further include at least one agitation unit that rotationally agitates the content inside the reactor.

With this configuration, a content is agitated, and, thus, the content inside the reactor can be more uniformly irradiated with microwaves. As a result, for example, a situation can be avoided in which only part of the content inside the reactor is irradiated with microwaves.

Advantageous Effects of Invention

The present invention provides a chemical reaction apparatus capable of preventing an unreacted content from being discharged, by preventing the content from flowing in a shortcut in a horizontal flow-type reactor.

DESCRIPTION OF EMBODIMENT

Hereinafter, a chemical reaction apparatus according to the present invention will be described by way of an embodiment. Note that constituent elements denoted by the same reference numerals are the same or similar to each other in the following embodiment, and, thus, a description thereof may not be repeated.

Below, a chemical reaction apparatus according to Embodiment 1 of the present invention will be described with reference to the drawings. The chemical reaction apparatus according to this embodiment irradiates the content of a reactor with microwaves.

FIG. 1is a diagram showing the configuration of a chemical reaction apparatus1according to this embodiment. The chemical reaction apparatus1according to this embodiment includes a mixing portion12, a reactor13, microwave generators14, waveguides15, a microwave control portion16, a catalyst separating portion17, and a treated liquid storage tank18.

The mixing portion12mixes a raw material and a solid catalyst. The mixing portion12may mix the raw material and the like with a reactant. The raw material may contain multiple materials. For example, in the case of performing esterification in the reactor13, fat and oils and alcohol may be used as the raw material. The raw material and the solid catalyst may be supplied to the mixing portion12by pumps11as shown inFIG. 1, or may be supplied to the mixing portion12using other methods. The mixing portion12may mix two or more materials, for example, by rotating a blade-like member, a wing-like member, or a screw-like member. Note that, although this embodiment describes the case in which the catalyst that is to be mixed with the raw material is a solid catalyst (heterogeneous catalyst), the catalyst may be a liquid catalyst (homogeneous catalyst). Furthermore, the solid catalyst may or may not form a fluidized bed inside the reactor13. Furthermore, there is no limitation on the shape of the solid catalyst. Examples of the shape of the solid catalyst include various grains, a cylinder (that may or may not be hollow), a sphere, a pellet, a ring, a shell, and other shapes. Furthermore, the solid catalyst may or may not be, for example, microwave-absorbing or microwave-sensitive. If the solid catalyst is microwave-absorbing or microwave-sensitive, when microwaves are irradiated inside the reactor13(described later), the solid catalyst is heated by the microwaves, and the chemical reaction near the solid catalyst is facilitated. Note that the microwave absorptivity and the microwave sensitivity depend on the frequency of microwaves used for irradiation, the temperature inside the reactor13, and the like. That is to say, materials that have a high dielectric loss factor, at the frequency of microwaves used and the temperature inside the reactor13in which the raw material is to undergo a reaction, provide a high microwave absorptivity. Accordingly, for example, a solid catalyst containing such a highly microwave-absorbing material may be used. For example, if microwaves at 2.45 GHz are irradiated, examples of the microwave-absorbing material include carbon except for fullerene (e.g., graphite, carbon nanotube, activated carbon, etc.), iron, nickel, cobalt, ferrite, and the like. Accordingly, the solid catalyst may contain such a microwave-absorbing material. Specifically, the solid catalyst may be a composite in which such a microwave-absorbing or microwave-sensitive material and a metal or metal oxide are combined, a composite in which such a microwave-absorbing or microwave-sensitive material and a catalyst such as alkali catalyst or acid catalyst are combined, or a composite in which a microwave-absorbing or microwave-sensitive material, a catalyst such as alkali catalyst or acid catalyst, and a metal or metal oxide are combined. The composite may be formed, for example, through physical adsorption, chemical bonding, alloying, or other methods. Furthermore, in the mixing portion12, preliminary heating may or may not be performed for preparation for the reaction in the reactor13. In the case of performing the preliminary heating, the temperature in the preliminary heating in the mixing portion12is preferably controlled such that the raw material and the like at the time of entering the reactor13are at a desired temperature or in a desired temperature range. Note that, in the case of not performing the preliminary heating in the mixing portion12, heating corresponding to the preliminary heating may be performed in the reactor13. The raw material and the solid catalyst mixed by the mixing portion12are loaded into the upstream side in the reactor13.

The reactor13is a horizontal flow-type reaction unit in which a liquid content horizontally flows with an unfilled space being provided thereabove. The reactor13in which the content horizontally flows refers to a reactor that is not a vertical flow-type reaction unit in which the content vertically flows, that is, the content does not have to strictly horizontally flow. It is sufficient that the content flows in a direction close to the horizontal direction on the whole. Examples of the content include a mixture of the raw material and the catalyst. The raw material and the catalyst mixed by the mixing portion12flow inside the reactor13. Note that, since the chemical reaction in the reactor13produces a product material from the raw material, the content of the reactor13may be considered to contain the product material. That is to say, the content may be referred to as the raw material and/or the product material. Furthermore, since an unfilled space is present above the content, the content is typically a material other than gas. Furthermore, the content can flow inside the reactor13and has a flat liquid surface, and, thus, the content is a material other than solid (e.g., powders or grains, etc.). Accordingly, the content is liquid. The liquid content may be for example, a material having a high flowability such as water, oil, aqueous solution, or colloidal solution, or may be a material having a low flowability such as slurry or suspension. It is preferable that the liquid surface of the content inside the reactor13is kept horizontal, and, thus, even in the case where the flowability of the liquid content is low, it preferably allows the liquid surface to be horizontal after a while without the application of vibration from the outside. That is to say, the liquid content preferably has a flowability that allows the shape of the surface to be changed without vibration from the outside. Note that the liquid surface being horizontal may refer to the state of being completely flat, or may refer to the state of being flat on the whole although there are slightly rough portions. The reason for this is that, if the content does not have a high flowability, the liquid surface may not be completely flat. The inner wall of the reactor13is preferably made of a microwave-reflecting material. Examples of the microwave-reflecting material include metal. The internal configuration of the reactor13will be described later.

The microwave generators14generate microwaves. The chemical reaction apparatus1according to this embodiment may include one microwave generator14, or may include two or more microwave generators14. There is no limitation on the frequency of the microwaves, and examples thereof include 2.45 GHz, 5.8 GHz, 24 GHz, 913 MHz, and other frequencies ranging from 300 MHz to 300 GHz.

The one or more waveguides15transmit the microwaves generated by the microwave generators14to the unfilled space in the reactor13. The number of waveguides15provided may be the same as the number of microwave generators14as shown inFIG. 1. Furthermore, the waveguide15may be branched and transmit the microwaves to two or more positions in the unfilled space. Note that the specification of the waveguides15is preferably in accordance with the frequency of the microwaves generated by the microwave generators14.

The microwave control portion16controls the power of microwaves used for irradiation in the reactor13, according to the temperature measured by temperature measuring portions25(described later). The control by the microwave control portion16makes it possible to keep inside the reactor13at a desired temperature or in a desired temperature range.

The catalyst separating portion17separates the catalyst from the product material after the reaction in the reactor13. If the catalyst that has been mixed with the raw material is a solid catalyst, for example, filtering may be used to separate the solid catalyst, or one of the solid catalyst and the product material may be precipitated to separate the solid catalyst. Furthermore, if the solid catalyst contains a magnetic substance, a magnet (that may be a permanent magnet or may be an electromagnet) for attracting the solid catalyst may be used to separate the solid catalyst. Note that the separated solid catalyst may be used again as appropriate. Furthermore, if a liquid catalyst is used, distillation, extraction, or neutralization may be performed in the catalyst separating portion17to separate the catalyst.

The product material from which the catalyst has been separated by the catalyst separating portion17is loaded into the treated liquid storage tank18. Then, this product material is separated as appropriate into a final product, a by-product, and the like. For example, if the raw material is free fatty acid, and esterification is performed in the reactor13, a product that is biodiesel fuel and a by-product that is water are obtained. In this case, an acid catalyst is used. Furthermore, for example, if the raw material is triglyceride, and transesterification is performed in the reactor13, a product that is biodiesel fuel and a by-product that is glycerin are obtained. In this case, an alkali catalyst is used.

Note that an unshown cooler that cools down the material after the reaction in the reactor13may or may not be provided on the path after the reactor13. In the former case, for example, the cooler may use water to cool down the material after the reaction in the reactor13.

FIG. 2is a view showing an exemplary internal structure of the reactor13according to this embodiment. InFIG. 2, the inside of the reactor13is partitioned by multiple partition plates21into multiple chambers31,32,33, and34. The multiple chambers31,32,33, and34are chambers that are continuously arranged in series. As described above, an unfilled space22is present in the upper portion inside the reactor13. The unfilled space22is irradiated with the microwaves generated by the microwave generators14and transmitted via the waveguides15. Note thatFIG. 2shows the case in which a single unfilled space is present inside the reactor13, that is, the case in which an unfilled space is shared by all the chambers31to34, but there is no limitation to this. That is to say, an unfilled space may be shared by at least two or more chambers that are part of all chambers, or may be shared by none of the chambers (in this case, there are unfilled spaces that have been separated from each other by the partition plates21). The waveguides15may or may not be provided respectively at the upstream positions in the chambers32,33, and34as shown inFIG. 2. In the former case, for example, the microwaves that have been transmitted by one waveguide15to the unfilled space22are mainly irradiated on the chamber present therebelow. Since microwaves are transmitted through an unfilled space, for example, the microwaves that have been transmitted by the waveguide15at the position of the chamber32are irradiated via the unfilled space also on the content in the chamber31and the chamber33. Note that the waveguides15may be provided at the positions of the partition plates21, that is, at the positions above the partition plates21. Accordingly, the microwaves that have been transmitted by one waveguide15to the unfilled space22are mainly irradiated on two chambers that have been partitioned from each other by the partition plate21at the position corresponding to that waveguide15. If the unfilled space22is shared by multiple chambers, the microwaves that have been transmitted to the shared unfilled space22are irradiated on a content20in the multiple chambers sharing the unfilled space22. The partition plates21may transmit microwaves, may absorb microwaves, or may reflect microwaves. Examples of the microwave-transmitting material include Teflon (registered trademark), quartz glass, ceramic, silicon nitride-alumina, and the like. Accordingly, the partition plates21that transmit microwaves may be made of such a microwave-transmitting material. Furthermore, examples of the microwave-absorbing material include carbon except for fullerene, and the like. Accordingly, the partition plates21that absorb microwaves may be made of such a microwave-absorbing material. Furthermore, examples of the microwave-reflecting material include metal. Accordingly, the partition plates21that do not transmit microwaves may be made of such a microwave-reflecting material. Furthermore, the partition plates21may be made of a combination of two or more freely selected from the microwave-transmitting material, the microwave-absorbing material, and the microwave-reflecting material.

Furthermore, as shown inFIG. 2, the chemical reaction apparatus1may further include agitation units23. That is to say, the chemical reaction apparatus1according to this embodiment may include one or more agitation units23that rotationally agitate the content20inside the reactor13.FIG. 2shows the case in which the chambers31to34respectively have the agitation units23, but there is no limitation to this. One or more chambers may not have the agitation unit23. Furthermore,FIG. 2shows the case in which each of the agitation units23is in the shape of a blade, but this merely schematically shows the agitation units23. The agitation may be performed, for example, by rotating a blade-like, wing-like, or rod-like rotatable member. The rotatable member may be made of a microwave-transmitting material, a microwave-absorbing material, a microwave-reflecting material, or a combination of two or more freely selected from the microwave-transmitting material, the microwave-absorbing material, and the microwave-reflecting material. The rotation may be performed, for example, by rotating a rotatable member attached to a shaft in accordance with the rotation of the shaft, or by rotating the rotatable member using a magnetic force as in the case of a magnetic stirrer. In the former case, the shaft may be provided independently for each chamber, or may be shared by multiple chambers. In the latter case, the rotatable member (magnetic stirrer) in the shape of a rod, a blade, a wing, or the like is rotated by a magnet. The agitation of the content by the agitation units23may be used to cause the content to flow from the upstream side to the downstream side, or in the opposite direction, but there is no limitation to this. Note that rotational agitation is already known, and, thus, a detailed description thereof has been omitted.

Hereinafter, reasons why the content of the reactor13is rotationally agitated by the agitation units23will be briefly described. A first reason why the content is agitated by the agitation units23is to uniformly heat the content with microwaves. Although depending on the type of content and the temperature of the content, the depth to which microwaves penetrate is fixed, and, thus, the agitation is performed in order to uniformly irradiate and uniformly heat the entire content with microwaves. Furthermore, the content can be more efficiently irradiated with microwaves as the surface area of the content at the unfilled space22increases. Accordingly, a second reason why the content is agitated is to increase the area subjected to microwave irradiation. Thus, the content is agitated by the agitation units23preferably at an intensity that allows the surface of the content at the unfilled space22to be disordered, but there is no limitation to this (if the agitation is performed for the first reason, it may be sufficient that the entire content is eventually heated). Furthermore, since the raw material and the like are agitated using the agitation units23in this manner, even in the case where a raw material contains two or more materials having different densities, these materials can be mixed and reacted with each other as appropriate. For example, when causing materials having different densities, such as alcohol and waste oil, to react with each other in a vertical flow-type reactor, these materials are easily separated from each other. However, as in this embodiment, if the reactor13is of a horizontal flow-type and is provided with the agitation units23, these materials can be mixed and reacted with each other as appropriate.

Furthermore, as shown inFIG. 2, the reactor13also may have the temperature measuring portions25. That is to say, the chemical reaction apparatus1according to this embodiment may have the temperature measuring portions25that measure the temperature inside the reactor13. The temperature inside the reactor13is preferably the temperature of the content of the reactor13.FIG. 2schematically shows the case in which the chambers31to34respectively have the temperature measuring portions25, but there is no limitation to this. One or more chambers may not have the temperature measuring portion25. Furthermore,FIG. 2merely schematically shows the temperature measuring portions25. The temperature measuring portions25may measure the temperature, for example, using a thermocouple, an infrared sensor, an optical fiber, or other methods. The temperature measured by the temperature measuring portions25(strictly speaking, data indicating the temperature) is passed to the microwave control portion16, and is used to control the power of microwaves from the microwave generators14. As described above, this control may be control for keeping the temperature of the chambers31to34at a desired temperature or in a desired temperature range. For example, if microwaves are irradiated on the position of each partition plate21, the power of microwaves irradiated on that position may be controlled, for example, using one or both of the temperatures of two chambers that have been partitioned from each other by the partition plate21at the position subjected to the microwave irradiation. In the former case, for example, the control may be performed using a lower temperature, using a higher temperature, or using a temperature of a chamber specified in advance. In the latter case, for example, the control may be performed using an average of these temperatures, or using a weighted average according to the capacities of both chambers (average in consideration of weights according to the capacities of the chambers).

Furthermore, the wall face of the reactor13may be covered by a heat insulating material. In that case, heat inside the reactor13can be prevented from being dissipated to the outside.

FIGS. 3A and 3Bare views showing an exemplary shape of the reactor13according to this embodiment. InFIGS. 3A and 3B, the partition plates21, the agitation units23, and the like have been omitted for the sake of convenience of the description. InFIGS. 3A and 3B, the reactor13according to this embodiment has a shape in which the area of the liquid surface does not change even in the case where the height of the liquid surface changes according to a change in the amount of the content. Note that “the area of the liquid surface does not change even in the case where the height of the liquid surface changes according to a change in the amount of the content” refers to that there is at least the range of the content within which the area of the liquid surface does not change even in the case where the amount of the content changes. Accordingly, it is conceivable that the area of the liquid surface does not change according to the amount of the content regardless of the amount of the content, or that the area of the liquid surface does not change according to the amount of the content as long as the amount of the content is within a predetermined range, that is, as long as the amount of the content is between a first amount and a second amount (assuming that the second amount is larger than the first amount). In this embodiment, the latter case will be mainly described. That is to say, in this embodiment, the reactor13has a shape in which the area of the liquid surface does not change according to a change in the amount of the content as long as the amount of the content is within a predetermined range. Accordingly, the reactor13may have a shape in which the cross-section in the liquid surface direction of the content does not change as long as the amount of the content is within a predetermined range, for example, as shown inFIGS. 3A and 3B. In this case, within the range of the height of the liquid surface when the amount of the content changes from the first amount to the second amount, the shape in the horizontal direction inside the reactor13corresponding to the height of the liquid surface does not change. Note that the above-described first amount is typically the lower limit value of the content in the case where the area of the liquid surface does not change, and the second amount is typically the upper limit value of the content in the case where the area of the liquid surface does not change. Furthermore, even when the content is at the second amount, an unfilled space has to be present above the content. The reason for this is that microwaves are irradiated via an unfilled space in the reactor13. Furthermore, the liquid surface may be disordered when agitation is performed inside the reactor13as described above, but the liquid surface described here is the liquid surface without such disorder or the like. Note that “the height of the liquid surface” is the height of the liquid surface in the vertical direction.

InFIG. 3A, the reactor13has a semicylindrical shape elongated in the flow direction and projecting downward. That is to say, the reactor13inFIG. 3Ahas a shape in which an open-topped semicylinder projecting downward and an open-bottomed rectangular solid having the same length as the semicylinder are joined at their openings. Note that the opening of the semicylinder and the opening of the rectangular solid have the same size and the same shape, and they are joined at their openings to form the reactor13. In other words, the reactor13inFIG. 3Ahas a hollow shape having a side face with a U-shaped cross-section and an upper face with a cross-section closing the opening of the U-shape, wherein the openings at both ends of the hollow shape are closed by flat faces perpendicular to the length direction. In the reactor13inFIG. 3A, the area of the liquid surface does not change as long as the height of the liquid surface of the content is within a range R1 (e.g., the heights at a level 1, at a level 2, etc.). Note that the height of the liquid surface at the lowest level in the range R1 corresponds to the lowest position in the rectangular solid forming the upper portion of the reactor13.

InFIG. 3B, the reactor13is in the shape of a rectangular solid. In the reactor13inFIG. 3B, the area of the liquid surface does not change as long as the height of the liquid surface of the content is within the range R1, which covers the entire height (e.g., the heights at the level 1, at the level 2, etc.). That is to say, the area of the liquid surface does not change regardless of the amount of the content.

Next, the partition plates21will be described. The content20such as a raw material loaded into the reactor13flows through the chambers31to34and is finally discharged from the downstream side (the right end of the reactor13inFIG. 2). Note that a flow path that allows the content to flow is formed at the partition plates21. In this embodiment, the flow path is an overflow-type flow path formed above the partition plates21. That is to say, in this embodiment, the content flows over each of the partition plates21. The flow path allows the content to flow from the upstream side (the left side inFIG. 2) to the downstream side (the right side inFIG. 2) in the reactor13.FIGS. 4A and 4Bare views showing the partition plate21provided in the reactor13in the shape as shown inFIG. 3A, in the length direction of the reactor13. The partition plate21does not extend to the position of the unfilled space22, and the content flows through that position (that is, over the partition plate21). The number of overflow-type flow paths may be three as shown inFIG. 4A, may be one as shown inFIG. 4B, or may be other numbers (two, or four or more). Furthermore, each flow path may be trapezoidal as shown inFIGS. 4A, 4B, and 5A, may be V-shaped as shown inFIG. 5B(wedge-shaped), may be quadrangular (rectangular) as shown inFIG. 5C, or may be in other shapes (e.g., U-shaped, semicircular, etc.). If the partition plate21has multiple flow paths, the flow paths may have different shapes, or may have the same shape. Furthermore, if the partition plate21has multiple flow paths, the bottoms of the flow paths (the lowest points of the flow paths) preferably have the same height. The height position of the bottom of a flow path may be referred to as a “weir height”. InFIGS. 5A to 5C, the position indicated by the left-pointing arrow is the weir height (the height position of the bottom of a flow path). The weir height indicates the height in the vertical direction. Furthermore, if the flow path is rectangular, the width of the flow path may be the same as the width of the reactor13. That is to say, the partition plate21in that case has, on the upper side thereof, no recess such as cutout (portion that has been cut out), and a flow path is formed throughout the width of the reactor13(full-width weir). AlthoughFIGS. 4A and 4Beach show a partition plate in the case where the unfilled space22is shared by two chambers that have been partitioned from each other by that partition plate21, the partition plate21may extend also to the position of the unfilled space22, in the case where the unfilled space22is not shared. For example, in the partition plate21inFIGS. 4A and 4B, the partition plate may extend to above the upper side of the trapezoidal flow path. That is to say, the partition plate21may have multiple trapezoidal holes in accordance with flow paths. Also in that case, in the flow paths respectively formed by the holes, the content may be regarded as flowing over the partition plate21. It will be appreciated that, if the reactor13has a shape other than that inFIG. 3A, the partition plate21is shaped in accordance with that shape of the reactor13. Furthermore, if there are multiple partition plates21inside the reactor13, the partition plates21may have the same shape, or may have different shapes. Furthermore, the partition plate21has a thickness of, for example, approximately 1 to 20 mm, which is sufficiently smaller than the length of each chamber (the length in the length direction of the reactor13).

(1) the Case in which the Reactor is not Inclined and there is a Height Difference Between the Partition Plates

Next, the weir heights of the partition plates21in the case where the reactor13is not inclined will be described. In this case, a description will be made focusing on the chamber33, but the same is applicable to the other chambers. As shown by the partition plate21on the right side inFIG. 6A, in an overflow-type flow path, the height of the content20is higher than the weir height of the partition plate21by an overflow depth H. The overflow depth is the height of an overflow when the content flows through the flow path over the partition plate21, that is, the height from the weir height to the highest position in the content (the height in the vertical direction). InFIGS. 5A to 5C, the overflow depth is indicated by H. Furthermore, in the case as shown inFIG. 6Awhere the reactor13is not inclined and the partition plate21on the inlet side (the left side in the drawing) of the chamber33and the partition plate21on the outlet side (the right side in the drawing) have the same weir height, the partition plate21on the inlet side of the chamber33and the partition plate21on the outlet side have the same overflow height, and the overflows at the partition plates21are directly connected in the left-right direction. Accordingly, at least part of the content20may move from the chamber32to the chamber34without being retained in the chamber33due to the directly connected overflows. That is to say, in the case ofFIG. 6A, the content20may flow in a shortcut and be discharged from the chamber33. Furthermore, also in the case as shown inFIG. 6Bwhere the weir height of the partition plate21on the inlet side of the chamber33is higher than the weir height of the partition plate21on the outlet side but at least part (shaded portion in the drawing) of the overflows at the partition plates21are directly connected in the left-right direction, at least part of the content20may flow in a shortcut without being retained in the chamber33due to the directly connected overflows. On the other hand, in the case as shown inFIG. 6Cwhere the weir height of the partition plate21on the inlet side of the chamber33is higher than the weir height of the partition plate21on the outlet side by the overflow depth H on the outlet side, the overflows at the partition plates21are not directly connected in any portion in the left-right direction. In this case, when the content20flows into chamber33over the partition plate21on the inlet side, all the content20moves at least downward. Thus, according to a decrease in the potential energy due to that movement, the content20that has flown into the chamber33sinks toward the bottom of the chamber33. Accordingly, in the case ofFIG. 6C, the content20that has flown into the chamber33via the overflow on the inlet side hardly flows out as it is via the overflow on the outlet side, compared with the cases ofFIGS. 6A and 6B. Thus, it seems that the content20can be effectively prevented from flowing in a shortcut. Accordingly, it is sufficient that, in each chamber of the reactor13, the weir height on the inlet side is higher than the weir height on the outlet side by at least the overflow depth H at the partition plate21on the outlet side. Accordingly, the content20can be prevented from flowing in a shortcut in each chamber. In order to achieve this, as described inFIG. 6C, the partition plates21may be used in which the height of the bottom of the flow path (weir height) at the partition plate21on the inlet side is higher than the height of the bottom of the flow path (weir height) at the partition plate21on the outlet side by at least the overflow depth H at the partition plate21on the outlet side, in each chamber of the reactor13that is not inclined. Furthermore, as described later, the weir height on the inlet side may be made higher than the weir height on the outlet side by at least the overflow depth H at the partition plate21on the outlet side in each chamber of the reactor13, by making the reactor13inclined. Furthermore, if the weir height of the partition plate21on the inlet side of the chamber33is higher than the weir height of the partition plate21on the outlet side by the overflow depth H on the outlet side in this manner, a reversed flow also can be prevented. Note that, inFIGS. 6A to 6C, the agitation units23and the temperature measuring portions25have been omitted for the sake of convenience of the description. Furthermore, portions of the partition plates21above the weir height also have been omitted for the sake of convenience of the description.

Next, the overflow depth H will be described. Below, a case will be described in which the partition plate21has N trapezoidal flow paths shown inFIG. 7. It is assumed that the N flow paths have the same shape and the same weir height. Note that, in the trapezoidal flow path inFIG. 7, if a width a of the bottom of the trapezoidal flow path is equal to a width b of the upper side, that is, if a=b, the flow path is rectangular. Furthermore, if the width a of the bottom of the trapezoidal flow path is 0, that is, if a=0, the flow path is V-shaped. Note that the height of the trapezoidal flow path is taken as e, and the z axis is set vertically downward from the upper face of the overflow. In this case, D(z) is represented by the following equation.

Using Bernoulli's theorem v=(2gz)1/2, a flow rate Q is represented by the following equation. In the equation, g is an acceleration of gravity, C is a flow coefficient, and v is a fluid velocity. The flow coefficient is determined according to the shape of the flow path, and, for example, may be calculated by experiment, or may be calculated by computation.
Q=∫0HCND(z)√{square root over (2gz dz)}

If D(z) above is substituted for this equation and integration is performed with z, the following equation is obtained.

Q=CN⁢2⁢g15⁢e⁢{4⁢(b-a)⁢H5/2+10⁢aeH3/2}
This equation can be rewritten as follows.
15eQ=√{square root over (2g)}CN{4(b−a)H5/2+10aeH3/2}

The overflow depth H can be calculated by solving this equation. Furthermore, if the flow paths are provided in the same number and have the same shape at the partition plates in the reactor13, the partition plates21have the same overflow depth H. Accordingly, if the partition plates21are designed such that the height of the bottom of the flow path (weir height) at the partition plate21on the inlet side is higher than the height of the bottom of the flow path (weir height) at its adjacent partition plate21on the outlet side by at least the overflow depth H, the content can be prevented from flowing in a shortcut in the reactor13, and, thus, an unreacted content can be prevented from being discharged out of the reactor13.

It is preferable that the height of an outlet in the last chamber34has the same relationship as that of the weir height described above. That is to say, it is preferable that, in the last chamber34, the height of the bottom of the flow path (weir height) at the partition plate21on the inlet side is higher than the height of the bottom of the flow path at the outlet by at least the overflow depth at the outlet. The shape of a flow path at the partition plates21is typically different from the shape of the outlet in the last chamber34, and, thus, the overflow depth at the outlet may be computed separately from the overflow depth H at the partition plates21. The overflow depth of a trapezoidal flow path can be calculated using D(z) above, and the overflow depth of a flow path in the other shapes can be calculated using D(z) according to that shape as appropriate and performing integration thereon.

Furthermore, in the case of (1), the flow paths may have different shapes and be provided in different numbers at the multiple partition plates21. In that case, the overflow depth Hiis calculated for each of the partition plates21. Here, i is an index (an integer of one or more) for identifying the partition plates21. It is sufficient that, in each chamber, the weir height on the inlet side is higher than the weir height on the outlet side by at least the overflow depth Hiat the partition plate21on the outlet side.

(2) the Case in which the Reactor is Inclined and there is No Height Difference Between the Partition Plates

Next, the case will be described in which the reactor13is inclined to realize the same effects as in the case where a height difference is provided between the partition plates21. It is assumed that the weir heights of the partition plates21are the same in the case where the reactor13is not inclined. Furthermore, the flow paths have the same shape and are provided in the same number at all of the multiple partition plates21. That is to say, if the cross-sections inside the reactor13in a direction orthogonal to the length direction of the reactor13do not change, all the partition plates21may have the same shape. Also in this case, if the reactor13is inclined such that the weir height on the inlet side is higher than the weir height on the outlet side by at least the overflow depth at the partition plate21on the outlet side in each chamber as shown inFIG. 8when the content20flows, that is, when the content20is treated, the same effects can be realized as in the case where a height difference is provided between the partition plates21as described above. It will be appreciated that the reactor13is inclined such that the inlet side of the content is positioned on the upper side and the outlet side is positioned on the lower side.

Hereinafter, an inclination angle in the case where the reactor13is inclined will be described. As shown inFIG. 9, the length of the chamber33in the length direction of the reactor13is taken as L. Although there is no limitation on length L, it is, for example, approximately 10 to 300 cm, preferably approximately 10 to 100 cm. Furthermore, it is assumed that the reactor13is inclined by an angle θ such that the inlet side is higher than the outlet side. Furthermore, the overflow depth at the partition plate21on the outlet side in the chamber33is taken as H. Accordingly, the weir height of the partition plate21on the inlet side of the chamber33and the weir height of the partition plate21on the outlet side are different from each other by H0=L sin θ. Accordingly, in order to make the weir height on the inlet side higher than the weir height on the outlet side by the overflow depth at the partition plate21on the outlet side, it is sufficient that H0=H, that is, L sin θ=H. Note that H can be calculated by solving the equation in description of the case in which a height difference is provided between the partition plates21. Accordingly, θ=sin−1(H/L) is obtained using the calculated H together with L. If the reactor13is inclined by at least θ, the weir height on the inlet side is higher than the weir height on the outlet side by at least the overflow depth H at the partition plate21on the outlet side. If all chambers have the same length, the thus calculated θ may be used. Otherwise, it is necessary to use L that is the length of the shortest chamber. The reason for this is that the θ corresponding to the length of the shortest chamber is the largest value. Accordingly, “L” in θ=sin−1(H/L) may be the shortest length of the lengths, in the length direction of the reactor13, of the respective chambers.

Note that, if the reactor13is inclined, in the strict sense, the partition plates21are also inclined. Thus, the flow path at the partition plates21is also inclined by the angle θ. Accordingly, strictly speaking, the overflow depth is different from the value of H obtained by solving the above-described equation, but the angle θ is typically a small value, and the difference in H depending on the presence or absence of the inclination is also small. Furthermore, since H is typically sufficiently small compared with L, there is no problem even if a change in H according to the inclination of the reactor13is not taken into consideration. It will be appreciated that the overflow depth H may be calculated taking the inclination of the reactor13into consideration as well, and the thus calculated H may be used to obtain the angle θ.FIG. 10shows an exemplary internal structure in the case where the reactor13is inclined.

Furthermore, also in the case where the reactor13is inclined, the last chamber34may be considered as in the case of (1). That is to say, the overflow depth at the outlet is calculated, and θ is calculated as described above, also for the last chamber34. The reactor13may be inclined by at least the larger value of θ calculated for the last chamber34and θ calculated for the other chambers.

(3) the Case in which the Reactor is Inclined and there is a Height Difference Between the Partition Plates

The above-described (1) and (2) may be combined. That is to say, in each chamber, the weir height on the inlet side can be made higher than the weir height on the outlet side by at least the overflow depth at the partition plate21on the outlet side, by making the reactor13inclined and providing a height difference between the partition plates21. In that case, the weir height of the partition plate21on the inlet side may be higher than the weir height of the flow path at the partition plate21on the outlet side by at least “H−L sin θ”. Note that H is the overflow depth at the partition plate21on the outlet side, L is the shortest length of the lengths, in the length direction of the reactor13, of the respective chambers, and θ is the inclination angle of the reactor13. Furthermore, also in this case, it is assumed that the flow paths have the same shape and are provided in the same number at the partition plates21, and the inclination angle of the reactor13is not so large.

In the description of (1) to (3) above, the overflow depth H is calculated using the shape of the flow path, the flow rate, and the like, but there is no limitation to this. The overflow depth H may be measured in the state where the content is actually caused to flow inside the reactor13. Further, the flow paths at the partition plates21may be designed or the inclination angle of the reactor13may be adjusted such that, in each chamber, the weir height on the inlet side is higher than the weir height on the outlet side by at least the overflow depth on the outlet side. In that case, the flow paths may not have the same shape and may not be provided in the same number at the partition plates21. That is to say, the flow paths may have different shapes, may be provided in different numbers, or may have different shapes and be provided in different numbers, at the partition plates21. Furthermore, if the overflow depth is measured, the reactor13may be made openable and closable above the unfilled space22, or may be provided with a window through which the inside of the reactor13can be observed from above the unfilled space22. In the latter case, the window preferably does not transmit microwaves, but, if the window transmits microwaves, the window may be covered by a material that does not transmit microwaves during irradiation of microwaves, and, only at the time of observation, the irradiation of microwaves may be stopped and the cover may be opened to perform the observation. In this case, the reactor13being openable and closable refers to the configuration in which the reactor13is provided with a lid member that can be opened and closed. The lid member may be, for example, an upper face plate of the reactor13, may be a door-like member, or may be another openable and closable member. Furthermore, if the overflow depth is measured, for example, scales for measuring the overflow depth may be provided at the flow paths at the positions of the partition plates21.

In the case of the first chamber31of the reactor13, that is, the chamber into which the content is loaded from the outside, the content is typically loaded from above as shown inFIG. 2and the like. Thus, consideration of the conditions relating to the partition plates21and the inclination angle as in the case of (1) to (3) described above is not necessary. However, if the content is caused to flow horizontally into the first chamber31as in the case of the following chambers, also in the first chamber31, the weir height on the inlet side (the height of the bottom of the flow path) may be set higher than the weir height on the outlet side by at least the overflow depth at the partition plate21on the outlet side, as described above.

Furthermore, the flow path at the partition plates21may or may not include a flow path that allows the content to flow through a void of the partition plates21in addition to the flow path that allows the content to flow over the partition plates21. That is to say, “the content flows over each of the partition plates21” refers to that at least the overflow-type flow path is present, and does not refer to that another flow path should not be present. In the former case, that is, if there is a flow path that allows the content to flow through a void of the partition plates21, the void may be a void27provided through the partition plate21as shown inFIG. 4C, may be a void27between the partition plate21and the reactor13as shown inFIG. 4D, or may be both voids. There is no limitation on the shape, the position, and the number of voids27. Furthermore, if the partition plate21has the void27, it is preferable that the content through the void27does not flow in a shortcut. Accordingly, for example, adjacent partition plates21may be arranged such that the partition plate21shown inFIG. 4Cand the partition plate21shown inFIG. 4Dare alternately arranged. Furthermore, if the partition plate21has the void27, the overflow depth H may be calculated taking the flow rate through that void into consideration as well, or the overflow depth H may be measured as described above. Furthermore, if the partition plate21has the void27, the flow path through the void27may allow part of the content to flow from the downstream side to the upstream side.

In the case where the reactor13is not inclined, the object can be realized also by making, in each chamber, the weir height on the inlet side higher than the weir height on the outlet side by at least five times or ten times the overflow depth at the partition plate21on the outlet side. However, with this configuration, a difference between the liquid surfaces of the respective chambers increases, and the capacity of the chamber decreases toward the downstream side, so that the amount of material that can be treated by the reactor13decreases. Accordingly, it is preferable that the difference between the weir height on the inlet side and the weir height on the outlet side in each chamber is not extremely large, although the difference has to be at least the overflow depth at the partition plate21on the outlet side. The difference between the weir heights may be, for example, approximately one to three times the overflow depth on the outlet side. Furthermore, also in the case where the reactor13is inclined, the capacity of each chamber decreases as the inclination angle is increased. Accordingly, it is preferable that the inclination angle is set such that the difference between the weir height on the inlet side and the weir height on the outlet side in each chamber is not extremely large, although the difference has to be at least the overflow depth at the partition plate21on the outlet side. Also in this case, the inclination angle may be set such that the difference between the weir heights is, for example, approximately one to three times the overflow depth on the outlet side. Note that, since the content flows into or flows out of each chamber, the height of the liquid surface may slightly increase or decrease in each chamber. Accordingly, as a precautionary measure, the partition plates21may be designed or the reactor13may be inclined such that, in each chamber, the difference between the weir height on the inlet side and the weir height on the outlet side is approximately two to three times the overflow depth on the outlet side. Furthermore, if agitation is performed using the agitation units23, the partition plates21may be designed or the reactor13may be inclined, using the overflow depth H when no agitation is performed.

Hereinafter, a specific example for computing the overflow depth and the like will be described. If flow rate Q=1000 (liter/hour)≅2.78×10−4(m3/s), width a of bottom of flow path=0.01 (m), width b of upper side of flow path=0.1 (m), height e of flow path=0.05 (m), flow coefficient C=0.6, number N of flow paths=3, and acceleration of gravity g=9.807 (m/s2),
H=0.017 (m).
In the equation, H is obtained by numerical computation. Accordingly, in the case of (1) above, it is sufficient that, in each chamber, the weir height of the partition plate21on the upstream side is higher than the weir height of the partition plate21on the downstream side by at least 1.7 cm. Accordingly, for example, the partition plates21may be designed such that the weir height of the partition plates21in the reactor13decreases stepwise by 2 cm toward the downstream side. Furthermore, in the case of (2) above, if the length L of each chamber=0.5 (m), then θ=0.035 (rad)=2.0°. Accordingly, it is sufficient that the reactor13is inclined by 2°.

Next, an operation of the chemical reaction apparatus1according to this embodiment will be briefly described. The raw material and the catalyst are supplied by the pumps11to the mixing portion12, are mixed in the mixing portion12, and are loaded into the reactor13. The speed of the raw material and the like supplied to the reactor13may be preferably in accordance with the flow rate Q.

The raw material and the like supplied to the reactor13flow from the upstream side to the downstream side while being agitated by the agitation units23. The microwaves generated by the microwave generators14are transmitted via the waveguides15to the unfilled space22in the reactor13, and are irradiated on the raw material and the like. At that time, overflows are not directly connected as described above, and, thus, the content can be prevented from flowing in a shortcut, and the content can be efficiently irradiated with microwaves. The raw material and the like are heated with the microwaves, and the reaction of the raw material and the like is facilitated. Note that the temperatures of the chambers31to34are measured by the temperature measuring portions25, and are passed to the microwave control portion16via a route that is not shown. Then, the microwave control portion16controls the power of the microwave generators14such that the temperatures of the chambers31to34are at a desired temperature or in a desired temperature range.

The product material discharged from the reactor13is loaded into the catalyst separating portion17where the catalyst is separated therefrom. Then, the product material from which the catalyst has been separated is loaded by the pump11into the treated liquid storage tank18. In the treated liquid storage tank18, the product material is separated into a target product and a by-product. In this manner, a final product is obtained. Furthermore, such treatment is repeatedly performed, and, thus, a target product is sequentially produced.

Note that the treatment that separates the catalyst in the catalyst separating portion17and the treatment that separates the product material into a product and a by-product in the treated liquid storage tank18may be performed sequentially each time the product material is loaded, or may be performed at a time when the amount of product material loaded accumulates and reaches a certain amount. That is to say, the treatment in the reactor13is of a flow-type (flow through-type), but the treatment in the catalyst separating portion17and the treated liquid storage tank18on the path thereafter may be of a flow-type, or may be of a batch-type.

Furthermore, there is no limitation on the chemical reaction caused to occur in the chemical reaction apparatus1according to this embodiment, as long as it is a chemical reaction that is caused to occur by microwave irradiation itself or by heat due to microwave irradiation. For example, the chemical reaction may be production of biodiesel fuel through esterification or transesterification, may be production of ink raw material that is ester, or may be other chemical reactions.

Next, a case will be described in which biodiesel fuel (fatty acid methyl ester) is produced from waste oil using the chemical reaction apparatus1according to this embodiment. It will be appreciated that the present invention is not limited to this reaction.

Reaction System Construction Example

As the raw material, a mixture of fat and oils and free fatty acid, and alcohol are used. The alcohol is used as a reactant. The raw material and the catalyst are sent by the pumps11into the mixing portion12, and are uniformly mixed. The mixed liquid is supplied to the reactor13. The mixed liquid inside the reactor13is irradiated with the microwaves generated by the microwave generators14, and, thus, the esterification reaction is facilitated. Furthermore, the mixed liquid inside the reactor13is loaded into the chambers31to34that have been partitioned from each other by the partition plates21inside the reactor13. The mixed liquid together with the catalyst is irradiated with microwaves while being agitated by the agitation units23, and, thus, the reaction progresses. The microwaves are irradiated on the unfilled space22inside the reactor13, and are diffused inside the reactor13. The reaction liquid in each chamber moves to its next chamber through a flow path provided at the partition plates21. The reaction liquid is held inside the reactor13for a certain retention time, and then is discharged out of the reactor13. The mixed liquid after the reaction discharged out of the reactor13is supplied to the catalyst separating portion17. After the catalyst is separated in the catalyst separating portion17, the mixed liquid is loaded into the treated liquid storage tank18. From the reaction liquid after the catalyst separation, water and glycerin that are by-products are further separated in the treated liquid storage tank18, and, thus, crude methyl ester that is a target product is obtained. The microwave power of the reactor13is subjected to feedback control based on the temperatures inside the chambers31to34, and, thus, the temperatures of the chambers31to34are kept constant. For example, the reaction temperature may be set at 70° C.

As described above, with the chemical reaction apparatus1according to this embodiment, overflows can be prevented from being directly connected in the horizontal direction between the chambers, by changing the height of the flow path at the partition plates21, making the reactor13inclined, or applying both of these configurations. Accordingly, the content can be prevented from flowing in a shortcut, so that the content can be irradiated with microwaves as appropriate. As a result, an unreacted content is prevented from being discharged out of the reactor13, and the yield in the chemical reaction apparatus1can be improved. Since the content inside the reactor13is agitated using the agitation units23, the content can be uniformly irradiated with microwaves even in the case where the depth to which microwaves penetrate is not so deep. Furthermore, since the reactor13is partitioned into multiple chambers, the content undergoes a reaction while being retained in each chamber, and, thus, the content can be effectively irradiated with microwaves in each chamber. Furthermore, if the solid catalyst is microwave-absorbing or microwave-sensitive, the solid catalyst is efficiently heated through microwave irradiation, and, thus, the chemical reaction near the solid catalyst can be facilitated. In this manner, the chemical reaction inside the reactor13is facilitated, and, thus, a product material can be more efficiently obtained.

Note that, in this embodiment, the case has been mainly described where the reactor13in which the area of the liquid surface does not change according to a change in the amount of the content is shaped such that the side face of the reactor13extends in the normal direction of the liquid surface as shown inFIGS. 3A and 3B, but there is no limitation to this. The reactor13may have a shape in which the area of the liquid surface does not change according to a change in the amount of the content also in the case where the side face of the reactor13extends in a direction different from the normal direction of the liquid surface. This configuration is realized, for example, in the case where the reactor13is installed so as to be inclined as shown inFIG. 10.

Furthermore, the case has been described with reference toFIG. 2where each chamber has the agitation unit23, but there is no limitation to this.

Multiple chambers may have a single or multiple agitation units23. If the chemical reaction apparatus1has a single agitation unit23, as described above, the agitation unit23may have a shaft (rotational shaft) shared by multiple chambers. In that case, the agitation unit23may include a rotational shaft, multiple rotatable members, and a rotating unit. The rotational shaft is a shaft extending in the flow direction in the reactor13. For example, inFIG. 2, the rotational shaft may extend from the left end face to the right end face of the reactor13. The rotational shaft may be provided in parallel to the bottom face of the reactor13. For example, this rotational shaft may be made of a microwave-transmitting material, a microwave-absorbing material, a microwave-reflecting material, or a combination of two or more freely selected from these materials. If the rotational shaft is made of a microwave-reflecting material (e.g., metal, etc.), microwaves irradiated on the rotational shaft are reflected. Accordingly, if the rotational shaft is present above the liquid surface of the content inside the reactor13in this case, part of the microwaves is reflected by the rotational shaft and is not irradiated on the content. Accordingly, in order to avoid such a situation, it is preferable that the liquid surface of the content is positioned above the rotational shaft, that is, the rotational shaft is present inside the content. Furthermore, if the rotational shaft is made of a microwave-absorbing material, microwaves irradiated on the rotational shaft are absorbed. Accordingly, if the rotational shaft is present above the liquid surface of the content inside the reactor13in this case, part of the microwaves is absorbed by the rotational shaft and is not irradiated on the content. Furthermore, the heat of the rotational shaft may abnormally increase. Accordingly, in order to avoid such a situation, it is preferable that the liquid surface of the content is positioned above the rotational shaft, that is, the rotational shaft is present inside the content. Accordingly, the amount of the content may be controlled such that the liquid surface of the content is above the rotational shaft, or the reactor13may have a shape in which the cross-sectional area in the liquid surface direction does not change at least above the rotational shaft. For example, as shown inFIG. 3C, the height of the liquid surface at the lowest level in the range R1in which the area of the liquid surface does not change may be set to the height at which the content just covers a rotational shaft28. Accordingly, if the liquid surface is within the range R1, the area of the liquid surface does not change, and the liquid surface is positioned above the rotational shaft28. Note that, in FIG.3C, the radius of the semicylindrical shape forming the lower portion of the reactor13is preferably in accordance with the rotational radius of the rotatable members rotating about the rotational shaft28. This configuration can effectively prevent a situation in which part of the content at the bottom of the reactor13fails to be agitated. Furthermore, for example, in the case of the reactor13shown inFIG. 3Din which the area of the liquid surface does not change as long as the height of the liquid surface of the content is within the range R1, which covers the entire height, the control can be performed such that the area of the liquid surface does not change, and such that the liquid surface is positioned above the rotational s haft28, by keeping the height of the liquid surface within the range R2. The height of the liquid surface at the lowest level in the range R2is set to the height at which the content just covers the rotational shaft28. Note that “above” and “below” are directions along the vertical direction. The same is applicable to “upper side” and “lower side”. Furthermore, “vertical direction” is a direction perpendicular to the horizontal plane. The flow direction in the reactor13is the flow direction of the content in the reactor13, and is typically the same as the length direction of the reactor13. The rotatable members are members that rotate about the rotational shaft. When the rotatable members rotate, the content is rotationally agitated. The rotatable members may be, for example, blade-like members, wing-like members, rod-like members, or the like, as described above. Furthermore, each chamber may have such a rotatable member, but there is no limitation to this. There may be a chamber having no rotatable member. Furthermore, one chamber may have two or more rotatable members. It is sufficient that the agitation units23have at least one or more rotatable members. The rotating unit rotates each rotatable member. If the rotatable members are fixed to the rotational shaft, the rotating unit may be a unit for rotating that rotational shaft. In that case, the rotating unit may be, for example, a motor, an engine, or the like. Furthermore, the rotational shaft may not rotate, but may support the rotatable member in a rotatable manner. In that case, for example, the rotating unit may rotate a rotatable member having a magnet, using a magnetic force. Specifically, as in the case of a motor that rotates a rotor configured by a permanent magnet, using a stator configured by an electromagnet provided around the rotor, it is possible to rotate the rotatable member (rotor) using the rotating unit (stator). Note that, in that case, the rotating unit that is a stator is preferably disposed outside the reactor13, but there is no limitation to this. The reason for this is that, depending on the material forming the reactor13, the rotating unit that is a stator cannot be disposed outside the reactor13. Furthermore, if the agitation units23have a rotational shaft extending in multiple chambers, holes through which the rotational shaft extends may be formed in the partition plates21. Furthermore, if there is a rotational shaft extending in multiple chambers, the rotational shaft may extend through the voids27of the partition plates21.

Furthermore, in this embodiment, the case has been described where the reactor13has a shape in which the cross-section in the liquid surface direction of the content does not change as long as the amount of the content is within a predetermined range, but there is no limitation to this. If the reactor13has a shape that ultimately prevents the area of the liquid surface from changing according to a change in the amount of the content as long as the amount of the content is within a predetermined range, it is not necessary that the cross-section in the liquid surface direction of the content does not change. Specifically, even in the case where the cross-section in the liquid surface direction of the content changes from one shape (e.g., rectangle, etc.) to another shape (e.g., trapezoid, etc.) according to the height of the liquid surface, as long as the cross-sectional area in the liquid surface direction of the content is the same throughout the height of the liquid surface, it can be said that the reactor13has a shape in which the area of the liquid surface does not change according to a change in the amount of the content even in the case where the cross-section in the liquid surface direction of the content changes.

Furthermore, in this embodiment, the case has been described where the reactor13has a shape in which the area of the liquid surface does not change even in the case where the height of the liquid surface changes according to a change in the amount of the content as long as the amount of the content is within a predetermined range, but there is no limitation to this. The area of the liquid surface may change according to a change in the amount of the content.

Furthermore, in this embodiment, there is no limitation on the number of rotational shafts or rotating units in the agitation units23. For example, a single rotational shaft and a single rotating unit may be used to rotate one or more rotatable members, or two or more rotational shafts and two or more rotating units may be used to rotate two or more rotatable members.

In this embodiment, the case has been described where the mixing portion12that mixes the raw material and the catalyst is provided, but there is no limitation to this. For example, if a premixture of the raw material and the catalyst is used, if the mixing is also performed by the reactor13, if the solid catalyst that flows inside the reactor13is retained in the reactor13, or if a solid catalyst forming a fixed bed is used instead of the solid catalyst that flows inside the reactor13, the chemical reaction apparatus1does not have to be provided with the mixing portion12. Note that, if a solid catalyst forming a fixed bed is used, typically, the solid catalyst forming a fixed bed is provided inside the reactor13. The solid catalyst forming a fixed bed may be fixed, for example, by being pasted on the inner wall of the reactor13, or by being placed in a catalyst filled layer, a column, or the like inside the reactor13. Examples of the shape of the solid catalyst include various grains, a cylinder (that may or may not be hollow), a sphere, a pellet, a ring, a shell, a honeycomb, a foam, a fiber, a cloth, a plate, and other shapes.

Furthermore, in this embodiment, the case has been described where the reactor13has four chambers31to34that are continuously arranged in series as shown inFIG. 2, but there is no limitation on the number of chambers. Typically, as the number of chambers increases, a situation can be more effectively prevented in which the raw material flows in a shortcut from the inlet to the outlet of the reactor13. Furthermore, if the capacity of each chamber does not change regardless of an increase or a decrease in the number of chambers, the retention time from when the content of the reactor13flows into the reactor13to when the content flows out of the reactor13becomes longer as the number of chambers increases, and the retention time becomes shorter as the number of chambers decreases. Accordingly, in this case, the number of chambers can be adjusted such that a desired retention time is obtained.

Furthermore, in this embodiment, the case has been described where the multiple microwave generators14are provided, but there is no limitation to this. For example, the microwaves generated by the microwave generator14may be transmitted via a branched waveguide15to multiple locations as shown in FIG.11. The multiple locations may be, for example, multiple chambers.FIG. 11shows the case in which the chemical reaction apparatus1is provided with only one microwave generator14, but, in the case where the chemical reaction apparatus1is provided with two or more microwave generators14, the microwaves generated by any one of the multiple microwave generators14may be transmitted via the branched waveguide15to multiple locations. For example, if the microwaves generated by the microwave generator14are transmitted to multiple chambers, the microwave control portion16may control the power of that microwave generator14using any or all of the temperatures of the chambers to which the microwaves generated by the microwave generator14are transmitted. For example, the microwave control portion16may perform the control using an average of all temperatures of the chambers, or may perform the control using a maximum value or a minimum value of the temperatures of the chambers.

Furthermore, in this embodiment, the case has been described where the chemical reaction apparatus1is provided with the temperature measuring portions25and the microwave control portion16, but there is no limitation to this. For example, if it is possible to keep the temperature inside the reactor13at a desired temperature or in a desired temperature range by setting the power of microwaves to a predetermined value, the control of the power of microwaves using the temperature does not have to be performed.

Furthermore, in this embodiment, the case has been described where the catalyst separating portion17is provided on the path after the reactor13, but there is no limitation to this. If the catalyst does not have to be separated by the chemical reaction apparatus1according to this embodiment, as in the case in which the catalyst is separated by another apparatus, the case in which the solid catalyst that flows inside the reactor13is retained in the reactor13, the case in which a solid catalyst forming a fixed bed is used instead of the solid catalyst that flows inside the reactor13, or the case in which no catalyst is used in the chemical reaction in the reactor13, the catalyst separating portion17does not have to be provided.

Furthermore, in this embodiment, the case has been described where the raw material and the catalyst are mixed and loaded into the reactor13, but there is no limitation to this. For example, only the raw material may be loaded into the reactor13. Furthermore, if the raw material and the catalyst are not mixed, only the raw material may flow inside the reactor13. That is to say, the content of the reactor13may be, for example, a mixture of multiple raw materials. Furthermore, even in the case where the raw material and the catalyst are not mixed, for example, the raw material and the catalyst may flow inside the reactor13when the solid catalyst that flows inside the reactor13is retained in the reactor13. Furthermore, if the raw material and the catalyst are not mixed, the mixing portion12may, for example, mix the raw material, or mix the raw material (substrate) and the reactant. Furthermore, if the raw material and the like do not have to be mixed, the chemical reaction apparatus1does not have to be provided with the mixing portion12as described above.

Furthermore, in this embodiment, the case has been described where one or more agitation units23that agitate the raw material inside the reactor13are provided, but there is no limitation to this. For example, if the reactor13is configured such that the entire raw material can be easily irradiated with microwaves (e.g., if the inner diameter of the reactor13is small, etc.), the agitation units23do not have to be provided.

Furthermore, in this embodiment, the case has been described where the chemical reaction apparatus1is provided with the treated liquid storage tank18, but there is no limitation to this. For example, a mixture of the product material and the by-product discharged from the chemical reaction apparatus1may be subjected to extraction of the product material and the like in another apparatus.

Furthermore, in this embodiment, the chemical reaction apparatus1may be provided with two or more microwave generators14, and the two or more microwave generators14may generate microwaves having two or more frequencies. That is to say, the content of the reactor13may be irradiated with microwaves having two or more frequencies. In that case, the microwaves having two or more frequencies may be irradiated on the same position, or may be respectively irradiated on different positions. For example, as shown inFIG. 12A, microwaves having frequencies X and Y respectively generated by microwave generators14aand14dmay be irradiated on the same position in the reactor13, that is, at the midstream in the reactor13. Note that the microwaves having the frequencies X and Y are respectively transmitted via waveguides15aand15dto the reactor13. Furthermore, for example, as shown inFIG. 12B, microwaves having a frequency X generated by microwave generators14a,14b, and14cmay be irradiated on the side from the upstream to the midstream in the reactor13, and microwaves having a frequency Y generated by a microwave generator14dmay be irradiated on the downstream side in the reactor13. Note that the microwaves having the frequency X are respectively transmitted via waveguides15a,15b, and15cto the reactor13. Furthermore, the microwaves having the frequency Y are transmitted via a waveguide15dto the reactor13.FIGS. 12A and 12Bare both views of the reactor13from above, wherein the arrows in the drawings indicate the flow of the content inside the reactor13. If microwaves having two or more frequencies are irradiated, the number of frequencies may be two, or three or more. There is no limitation on the combination of two or more frequencies, as long as they are selected from the range from 300 MHz to 300 GHz. For example, if microwaves having two frequencies are irradiated, examples of the combination of these frequencies include 2.45 GHz and 5.8 GHz, 2.45 GHz and 24 GHz, 2.45 GHz and 913 MHz, 5.8 GHz and 24 GHz, 5.8 GHz and 913 MHz, and 24 GHz and 913 MHz. Furthermore, if microwaves having two or more frequencies are irradiated, there is no limitation on the irradiation timing. For example, microwaves having two or more frequencies may be simultaneously irradiated, or may be irradiated respectively in different irradiation periods. For example, in the latter case, microwaves having the frequency X may be irradiated in one period, and microwaves having the frequency Y may be irradiated in the next period. Furthermore, if microwaves having two or more frequencies are irradiated, the microwaves having two or more frequencies may be introduced to one unfilled space22, or may be introduced to different unfilled spaces22. In the latter case, there are at least two or more unfilled spaces22that have been separated from each other by the partition plate21inside the reactor13. Note that if microwaves having two or more frequencies are irradiated, a material that is not affected by the action (e.g., heating, etc.) of microwaves having one frequency can be also affected, and, thus, a wider range of materials can be affected by the microwaves.

Furthermore, in the foregoing embodiment, information relating to the processing performed by each constituent element, for example, information that is to be accepted, acquired, selected, produced, transmitted, or received by each constituent element, information such as a threshold value, a numerical expression, or an address used in each constituent element in the processing and the like may be retained in an unshown storage medium temporarily or for a long period of time even if not specified in the description above. Furthermore, information may be accumulated in the unshown storage medium by each constituent element or by an unshown accumulating unit. Furthermore, information may be read from the unshown storage medium by each constituent element or by an unshown reading unit.

Furthermore, in the foregoing embodiment, if information used in each constituent element or the like, for example, information such as a threshold value, an address, or various setting values used in each constituent element in the processing may be changed by a user, the user may change such information as appropriate even if not specified in the description above, but there is no limitation to this. If the user may change such information, the change may be realized by, for example, an unshown accepting unit that accepts a change instruction from the user and an unshown changing unit that changes information according to the change instruction. The change instruction may be accepted by the unshown accepting unit, for example, by accepting information from an input device, by receiving information transmitted via a communication line, or by accepting information read from a predetermined storage medium.

Furthermore, in the foregoing embodiment, each constituent element may be configured by dedicated hardware, or, alternatively, constituent elements that can be realized by software may be realized by executing a program. For example, each constituent element may be realized by a program execution unit such as a CPU reading and executing a software program stored in a storage medium such as a hard disk or a semiconductor memory.

Furthermore, it will be appreciated that the present invention is not limited to the embodiment set forth herein, and various modifications are possible within the scope of the present invention.

INDUSTRIAL APPLICABILITY

As described above, the chemical reaction apparatus according to the present invention is effective in that a content can be prevented from flowing in a shortcut, and, thus, it is useful, for example, as a chemical reaction apparatus for performing microwave irradiation.