Organic hydride production apparatus, organic hydride production system, and organic hydride production method

Abstract

This apparatus 2 for producing an organic hydride is provided with: a cathode chamber 18 which contains a cathode electrode 14 for generating an organic hydride by hydrogenating an object to be hydrogenated in a cathode solution by means of protons; a cathode inlet 30 which is connected to the cathode chamber 18 in order to supply the cathode solution into the cathode chamber 18 from the outside; an upper cathode outlet 32 which is connected to the cathode chamber 18 in order to discharge the cathode solution and a hydrogen gas to the outside from the cathode chamber 18; and a lower cathode outlet 34 which is connected to the cathode chamber 18 at a lower position than the upper cathode outlet 32 in order to discharge the cathode solution and water to the outside from the cathode chamber 18.

Description

Organic hydride production apparatus and organic hydride production method

[0001] The present invention relates to an organic hydride manufacturing apparatus and an organic hydride manufacturing method.

[0002] In recent years, the use of renewable energy sources such as solar, wind, hydroelectric, and geothermal power has been expected to reduce carbon dioxide emissions during the energy generation process. One example is a system that generates hydrogen by electrolyzing water using electricity derived from renewable energy. Organic hydride systems have also attracted attention as an energy carrier for the large-scale transport and storage of hydrogen derived from renewable energy.

[0003] Conventionally, an organic hydride production apparatus has been known that is composed of an electrolytic cell having an oxidizing electrode that generates protons from water and a reducing electrode that hydrogenates an organic compound having an unsaturated bond (a substance to be hydrogenated) (see, for example, Patent Document 1). In this organic hydride production apparatus, water is supplied to the oxidizing electrode, and a substance to be hydrogenated is supplied to the reducing electrode, while a current is passed between the oxidizing electrode and the reducing electrode, whereby hydrogen is added to the substance to be hydrogenated, thereby obtaining an organic hydride.

[0004] International Publication No. 2012 / 091128

[0005] As a result of extensive research into the above-mentioned organic hydride production techniques, the present inventors have come to recognize that there is room for improvement in the faradic efficiency (current efficiency) of conventional techniques when producing organic hydrides.

[0006] The present invention has been made in view of the above circumstances, and one of its objects is to provide a technique for improving the faradic efficiency during the production of organic hydrides.

[0007] One aspect of the present invention is an organic hydride manufacturing apparatus comprising: a cathode chamber accommodating a cathode electrode that hydrogenates a substance to be hydrided in a cathode fluid with protons to produce an organic hydride; a cathode inlet connected to the cathode chamber for supplying an external cathode fluid into the cathode chamber; an upper cathode outlet connected to the cathode chamber for discharging the cathode fluid and hydrogen gas in the cathode chamber to the outside; and a lower cathode outlet connected to the cathode chamber below the upper cathode outlet for discharging the cathode fluid and water in the cathode chamber to the outside.

[0008] Another aspect of the present invention is a method for producing an organic hydride, which includes supplying a catholyte to a cathode chamber accommodating a cathode electrode that hydrogenates a substance to be hydrided in the catholyte with protons to produce an organic hydride, discharging the catholyte and hydrogen gas in the cathode chamber from the cathode chamber to the outside, and discharging the catholyte and water in the cathode chamber to the outside below the discharge positions of the catholyte and hydrogen gas.

[0009] Any combination of the above components, and conversion of the expression of the present disclosure into a method, device, system, etc., are also valid aspects of the present disclosure.

[0010] According to the present invention, the faradaic efficiency during the production of an organic hydride can be improved.

[0011] 2A is a schematic diagram of an organic hydride manufacturing system according to embodiment 1. FIG. 2A is a schematic diagram showing an example of the arrangement of a cathode inlet, an upper cathode outlet, and a lower cathode outlet. FIG. 2B is a schematic diagram showing another example of the arrangement of a cathode inlet, an upper cathode outlet, and a lower cathode outlet. FIG. 2B is a schematic diagram of an organic hydride manufacturing system according to embodiment 2. FIG. 4A is a schematic diagram showing an example of the arrangement of a cathode inlet, an upper cathode outlet, and a lower cathode outlet. FIG. 4B is a schematic diagram showing another example of the arrangement of a cathode inlet, an upper cathode outlet, and a lower cathode outlet.

[0012] The present invention will be described below with reference to the drawings based on preferred embodiments. The embodiments are illustrative and do not limit the invention, and all features and combinations thereof described in the embodiments are not necessarily essential to the invention. The same or equivalent components, parts, and processes shown in the drawings are designated by the same reference numerals, and redundant descriptions will be omitted where appropriate. The scale and shape of each part shown in each drawing are set for convenience to facilitate explanation and should not be interpreted as limiting unless otherwise specified. Furthermore, when terms such as "first" and "second" are used in this specification or claims, these terms do not indicate any order or importance, but are intended to distinguish one configuration from another. Furthermore, some components that are not important for explaining the embodiments are omitted from the drawings.

[0013] 1 is a schematic diagram of an organic hydride production system 1 according to Embodiment 1. The organic hydride production system 1 mainly comprises an organic hydride production apparatus 2, a power supply 4, an anolyte supply device 6, a catholyte supply device 8, and a control device 10.

[0014] The organic hydride production apparatus 2 is an electrolytic cell that hydrogenates a material to be hydrided, which is a dehydrogenated form of organic hydride, by an electrochemical reduction reaction to produce organic hydride. The organic hydride production apparatus 2 has an anode electrode 12, a cathode electrode 14, an anode chamber 16, a cathode chamber 18, and a diaphragm 20. Although only one organic hydride production apparatus 2 is shown in FIG. 1 , the organic hydride production system 1 may include multiple organic hydride production apparatuses 2. In this case, the organic hydride production apparatuses 2 are stacked, for example, with their orientations aligned such that the anode chambers 16 and cathode chambers 18 are aligned in the same order. As a result, the organic hydride production apparatuses 2 are electrically connected in series. The organic hydride production apparatuses 2 may be connected in parallel, or a combination of series and parallel connections may be used.

[0015] The anode electrode 12 (anode) oxidizes water in the anolyte to generate protons. The anode electrode 12 contains an anode catalyst, such as a metal such as iridium (Ir), ruthenium (Ru), or platinum (Pt), or an oxide of these metals. The anode catalyst may be dispersed and supported on or coated on an electronically conductive substrate. The substrate is composed of a material primarily composed of a metal such as titanium (Ti) or stainless steel (SUS). Examples of the substrate form include woven or nonwoven sheets, mesh, porous sintered bodies, foamed molded bodies, and expanded metals.

[0016] The cathode electrode 14 (negative electrode) hydrogenates the substance to be hydrogenated in the catholyte with protons to produce an organic hydride. The cathode electrode 14 of this embodiment has a catalyst layer 14a and a diffusion layer 14b. The catalyst layer 14a is disposed closer to the membrane 20 than the diffusion layer 14b. The catalyst layer 14a of this embodiment is in contact with the main surface of the membrane 20. The catalyst layer 14a contains, for example, platinum or ruthenium as a cathode catalyst that hydrogenates the substance to be hydrogenated. Preferably, the catalyst layer 14a also contains a porous catalyst support that supports the cathode catalyst. The catalyst support is made of an electron-conductive material, for example, porous carbon, porous metal, porous metal oxide, or the like.

[0017] The cathode catalyst is coated with an ionomer (cation exchange type ionomer). For example, a catalyst support supporting the cathode catalyst is coated with the ionomer. Examples of the ionomer include perfluorosulfonic acid polymers such as Nafion (registered trademark) and Flemion (registered trademark). It is preferable that the ionomer partially coats the cathode catalyst. This allows the three elements (substances to be hydrided, protons, and electrons) necessary for the electrochemical reaction in the catalyst layer 14a to be efficiently supplied to the reaction field.

[0018] The diffusion layer 14b uniformly diffuses the liquid material to be hydrided, which is supplied from the outside, into the catalyst layer 14a. The organic hydride produced in the catalyst layer 14a is discharged to the outside of the cathode electrode 14 through the diffusion layer 14b. In this embodiment, the diffusion layer 14b is in contact with the main surface of the catalyst layer 14a opposite the diaphragm 20. The diffusion layer 14b is made of a conductive material such as carbon or metal. The diffusion layer 14b is a porous body such as a sintered body of fibers or particles, or a foam molded body. Specific examples of materials that can be used to form the diffusion layer 14b include woven carbon fabric (carbon cloth), nonwoven carbon fabric, and carbon paper.

[0019] The anode electrode 12 is housed in the anode chamber 16. The anode chamber 16 is partitioned by, for example, a diaphragm 20, a plate portion 22a, and a spacer 24a. When the organic hydride production system 1 includes only one organic hydride production apparatus 2, the plate portion 22a may correspond to a so-called end plate. When the organic hydride production system 1 includes multiple organic hydride production apparatuses 2 and the organic hydride production apparatuses 2 are arranged next to the plate portion 22a, the plate portion 22a may correspond to a so-called separator.

[0020] The plate portion 22a is a plate member made of a metal such as stainless steel or titanium. The plate portion 22a is disposed on the opposite side of the anode electrode 12 from the diaphragm 20 and constitutes part of the anode chamber 16. As an example, the plate portion 22a has a groove-shaped flow path on the surface that defines the anode chamber 16, i.e., the main surface facing the anode electrode 12. The anolyte supplied to the anode chamber 16 passes through this flow path to the anode electrode 12 and is discharged from the anode chamber 16 through this flow path. The spacer 24a is a frame-shaped sealing material disposed between the diaphragm 20 and the plate portion 22a. The space in the anode chamber 16 excluding the anode electrode 12 constitutes the flow path for the anolyte.

[0021] The organic hydride manufacturing apparatus 2 includes an anode inlet 26 and an anode outlet 28 connected to the anode chamber 16. The anode inlet 26 is an opening for supplying external anolyte into the anode chamber 16. The anode outlet 28 is an opening for discharging the anolyte in the anode chamber 16 to the outside. The anode inlet 26 and the anode outlet 28 are provided, for example, in the plate portion 22a. The anode inlet 26 is located below the anode outlet 28. In this embodiment, the anode inlet 26 is provided on the bottom surface of the anode chamber 16, and the anode outlet 28 is provided on the top surface of the anode chamber 16. The anode inlet 26 and the anode outlet 28 may or may not overlap when viewed vertically.

[0022] The cathode electrode 14 is housed in the cathode chamber 18. The cathode chamber 18 is defined by, for example, a diaphragm 20, a plate portion 22b, and a spacer 24b. Like the plate portion 22a, the plate portion 22b may serve as an end plate or a separator. The plate portion 22b is a plate material made of a metal such as stainless steel or titanium. The plate portion 22b is located on the opposite side of the cathode electrode 14 from the diaphragm 20 and constitutes part of the cathode chamber 18. As an example, the plate portion 22b has a groove-shaped flow path on the surface that defines the cathode chamber 18, i.e., the main surface facing the cathode electrode 14. The catholyte supplied to the cathode chamber 18 passes through this flow path to the cathode electrode 14 and is discharged from the cathode chamber 18 through this flow path. The spacer 24b is a frame-shaped sealing material disposed between the diaphragm 20 and the plate portion 22b. The space in the cathode chamber 18 excluding the cathode electrode 14 constitutes a flow path for the catholyte.

[0023] The organic hydride production apparatus 2 includes a cathode inlet 30, an upper cathode outlet 32, and a lower cathode outlet 34, which are connected to the cathode chamber 18. The cathode inlet 30 is an opening for supplying external cathode fluid into the cathode chamber 18. The upper cathode outlet 32 ​​is an opening for discharging the cathode fluid in the cathode chamber 18 and hydrogen gas (described later) to the outside. The lower cathode outlet 34 is an opening for discharging the cathode fluid in the cathode chamber 18 and water (described later) to the outside. The cathode inlet 30, the upper cathode outlet 32, and the lower cathode outlet 34 are provided, for example, in the plate portion 22b. The arrangements and functions of the cathode inlet 30, the upper cathode outlet 32, and the lower cathode outlet 34 will be described in detail later. Note that FIG. 1 schematically illustrates the positions of the cathode inlet 30, the upper cathode outlet 32, and the lower cathode outlet 34.

[0024] The anode chamber 16 and the cathode chamber 18 are separated by a diaphragm 20. The diaphragm 20 is sandwiched between the anode electrode 12 and the cathode electrode 14. In this embodiment, the diaphragm 20 is made of a solid polymer electrolyte membrane having proton conductivity, and allows protons to move from the anode chamber 16 side to the cathode chamber 18 side. The solid polymer electrolyte membrane is not particularly limited as long as it is made of a material that conducts protons, and examples thereof include a fluorine-based ion exchange membrane having sulfonic acid groups.

[0025] An anolyte is supplied to the anode chamber 16 by an anolyte supply device 6. The anolyte contains water to be supplied to the anode electrode 12. Examples of the anolyte include an aqueous sulfuric acid solution, an aqueous nitric acid solution, an aqueous hydrochloric acid solution, pure water, and ion-exchanged water.

[0026] A cathode fluid is supplied to the cathode chamber 18 by the cathode fluid supply device 8. The cathode fluid contains an organic hydride raw material (material to be hydrided) to be supplied to the cathode electrode 14. As an example, the cathode fluid does not contain any organic hydride before the organic hydride production system 1 starts operating, and after the start of operation, the cathode fluid is mixed with organic hydride produced by electrolysis, thereby becoming a mixed liquid of the material to be hydrided and the organic hydride. The material to be hydrided and the organic hydride are preferably liquids at 20°C and 1 atmosphere.

[0027] The material to be hydrogenated and the organic hydride used in this embodiment are not particularly limited as long as they are organic compounds that can add / desorb hydrogen by reversibly causing a hydrogenation reaction / dehydrogenation reaction. A wide range of materials can be used as the material to be hydrogenated and the organic hydride, including acetone-isopropanol systems, benzoquinone-hydroquinone systems, and aromatic hydrocarbon systems. Among these, aromatic hydrocarbon systems are preferred from the viewpoint of transportability during energy transportation.

[0028] The aromatic hydrocarbon compound used as the substance to be hydrogenated is a compound containing at least one aromatic ring. Examples of aromatic hydrocarbon compounds include benzene, alkylbenzene, naphthalene, alkylnaphthalene, anthracene, diphenylethane, and the like. Alkylbenzenes include compounds in which one to four hydrogen atoms on the aromatic ring are substituted with a linear or branched alkyl group having one to six carbon atoms. Examples of such compounds include toluene, xylene, mesitylene, ethylbenzene, and diethylbenzene. Alkylnaphthalenes include compounds in which one to four hydrogen atoms on the aromatic ring are substituted with a linear or branched alkyl group having one to six carbon atoms. Examples of such compounds include methylnaphthalene. These compounds may be used alone or in combination.

[0029] The substance to be hydrogenated is preferably at least one of toluene and benzene. Nitrogen-containing heterocyclic aromatic compounds such as pyridine, pyrimidine, pyrazine, quinoline, isoquinoline, N-alkylpyrrole, N-alkylindole, and N-alkyldibenzopyrrole can also be used as the substance to be hydrogenated. Organic hydrides are the hydrogenated versions of the above-mentioned substances to be hydrogenated, and examples thereof include cyclohexane, methylcyclohexane, dimethylcyclohexane, and piperidine.

[0030] In the organic hydride production apparatus 2, the reaction that occurs when toluene (TL) is used as an example of the substance to be hydrogenated is as follows. When toluene is used as the substance to be hydrogenated, the organic hydride obtained is methylcyclohexane (MCH). <Electrode reaction at the anode electrode> 3H２ O → 3 / 2O ２ +6H ＋ +6e － <Electrode reaction at the cathode electrode> TL+6H ＋ +6e － →MCH

[0031] That is, the electrode reaction at the anode electrode 12 and the electrode reaction at the cathode electrode 14 proceed in parallel. Protons produced by the electrolysis of water at the anode electrode 12 are supplied to the cathode electrode 14 via the diaphragm 20. Electrons produced by the electrolysis of water are supplied to the cathode electrode 14 via the plate portion 22a, the external circuit, and the plate portion 22b. The protons and electrons supplied to the cathode electrode 14 are used to hydrogenate toluene at the cathode electrode 14. As a result, methylcyclohexane is produced.

[0032] Therefore, according to the organic hydride producing system 1 of this embodiment, the electrolysis of water and the hydrogenation reaction of the material to be hydrogenated can be carried out in one step. This improves the efficiency of organic hydride production compared to conventional techniques for producing organic hydrides through a two-stage process consisting of a process for producing hydrogen by water electrolysis or the like and a process for chemically hydrogenating the material to be hydrogenated in a reactor of a plant or the like. Furthermore, since a reactor for chemical hydrogenation and a high-pressure vessel for storing hydrogen produced by water electrolysis or the like are not required, a significant reduction in facility costs can be achieved.

[0033] At the cathode electrode 14, in addition to the main reaction of hydrogenation of the material to be hydrogenated, the side reaction of hydrogen gas generation shown below may occur. As the amount of material to be hydrogenated supplied to the catalyst layer 14a becomes insufficient, this side reaction becomes more likely to occur. <Side reactions that may occur at the cathode electrode> 2H ＋ +2e － →H ２

[0034] Furthermore, the protons migrate along with water molecules when they move from the anode chamber 16 to the cathode chamber 18 through the diaphragm 20. Therefore, as the electrolytic reduction reaction progresses, water accumulates in the cathode chamber 18.

[0035] The power supply 4 is a DC power supply that supplies power to the organic hydride manufacturing apparatus 2. When power is supplied from the power supply 4 to the organic hydride manufacturing apparatus 2, a predetermined electrolysis voltage is applied between the anode electrode 12 and the cathode electrode 14 of the organic hydride manufacturing apparatus 2, causing an electrolysis current to flow. The power supply 4 receives power from a power supply device 36 and supplies power to the organic hydride manufacturing apparatus 2. The power supply device 36 may be a power generation device that generates power using renewable energy, such as a wind power generation device or a solar power generation device. Note that the power supply device 36 is not limited to a power generation device that uses renewable energy, and may be a system power supply, or a power storage device that stores power from a renewable energy power generation device or a system power supply. Alternatively, two or more of these may be combined.

[0036] The anode fluid supply device 6 supplies the anode fluid to the anode chamber 16. The anode fluid supply device 6 has an anode fluid tank 38, a gas-liquid separation unit 40, a first anode pipe 42, a second anode pipe 44, a third anode pipe 46, a first anode pump 48, and a second anode pump 50. The gas-liquid separation unit 40 can be configured with a known gas-liquid separation tank. The first anode pump 48 and the second anode pump 50 can be configured with known pumps such as gear pumps or cylinder pumps. The anode fluid supply device 6 may circulate the anode fluid using a fluid delivery device other than a pump.

[0037] The anolyte tank 38 stores the anolyte to be supplied to the anode chamber 16. The anolyte tank 38 is connected to the anode chamber 16 by a first anode pipe 42. One end of the first anode pipe 42 is connected to the anolyte tank 38, and the other end is connected to the anode inlet 26. A first anode pump 48 is provided in the middle of the first anode pipe 42. The gas-liquid separation unit 40 is connected to the anode chamber 16 by a second anode pipe 44. One end of the second anode pipe 44 is connected to the anode outlet 28, and the other end is connected to the gas-liquid separation unit 40. The gas-liquid separation unit 40 is connected to the anolyte tank 38 by a third anode pipe 46. A second anode pump 50 is provided in the middle of the third anode pipe 46.

[0038] The anolyte in the anolyte tank 38 flows into the anode chamber 16 from the anode inlet 26 via the first anode piping 42 by driving the first anode pump 48. The anolyte is supplied to the anode chamber 16 by upflow and is used for the electrode reaction at the anode electrode 12. The anolyte in the anode chamber 16 is discharged from the anode outlet 28 and flows into the gas-liquid separator 40 via the second anode piping 44. Oxygen gas is generated by the electrode reaction at the anode electrode 12. Therefore, the anolyte discharged from the anode chamber 16 contains oxygen gas. The gas-liquid separator 40 separates the oxygen gas from the anolyte and discharges it outside the system. The anolyte from which the oxygen gas has been separated is returned to the anolyte tank 38 via the third anode piping 46 by driving the second anode pump 50.

[0039] The anolyte supply device 6 of the present embodiment circulates the anolyte between the anode chamber 16 and the anolyte tank 38. However, the present invention is not limited to this configuration, and the anolyte may be sent from the anode chamber 16 to the outside of the system without being returned to the anolyte tank 38.

[0040] The cathode fluid supply device 8 supplies cathode fluid to the cathode chamber 18. The cathode fluid supply device 8 includes a cathode fluid tank 52, a gas-liquid separation unit 54, an oil-water separation unit 56, a first cathode pipe 58 to a sixth cathode pipe 68, a first cathode pump 70 to a fifth cathode pump 78, and a first on-off valve 80 to a second on-off valve 82. The gas-liquid separation unit 54 can be configured as a known gas-liquid separation tank. The oil-water separation unit 56 can be configured as a known oil-water separation tank. The first cathode pump 70 to the fifth cathode pump 78 can be configured as known pumps such as gear pumps or cylinder pumps. Note that the cathode fluid supply device 8 may circulate the cathode fluid using a fluid delivery device other than a pump. The first on-off valve 80 and the second on-off valve 82 can be configured as known valves such as solenoid valves or air-driven valves.

[0041] The cathode fluid tank 52 stores the cathode fluid to be supplied to the cathode chamber 18. The cathode fluid tank 52 is connected to the cathode chamber 18 by a first cathode piping 58. One end of the first cathode piping 58 is connected to the cathode fluid tank 52, and the other end is connected to the cathode inlet 30. A first cathode pump 70 and a first on-off valve 80 are provided midway along the first cathode piping 58. The first cathode pump 70 is disposed closer to the cathode chamber 18 than the first on-off valve 80. The gas-liquid separation unit 54 is connected to the cathode chamber 18 by a second cathode piping 60. One end of the second cathode piping 60 is connected to the upper cathode outlet 32, and the other end is connected to the gas-liquid separation unit 54.

[0042] The oil-water separation unit 56 is connected to the gas-liquid separation unit 54 by a third cathode piping 62. A second cathode pump 72 and a second on-off valve 82 are provided in the third cathode piping 62. The second cathode pump 72 is disposed closer to the gas-liquid separation unit 54 than the second on-off valve 82. The oil-water separation unit 56 is also connected to the cathode chamber 18 by a fourth cathode piping 64. One end of the fourth cathode piping 64 is connected to the lower cathode outlet 34, and the other end is connected to the oil-water separation unit 56. A third cathode pump 74 is provided in the fourth cathode piping 64. In this embodiment, the other end of the fourth cathode piping 64 is connected to a region of the third cathode piping 62 closer to the oil-water separation unit 56 than the second on-off valve 82, and is thereby connected to the oil-water separation unit 56 via the third cathode piping 62. However, the present invention is not limited to this configuration, and the fourth cathode pipe 64 may be directly connected to the oil-water separator 56 .

[0043] The oil-water separation unit 56 is also connected to the cathode fluid tank 52 by a fifth cathode piping 66. A fourth cathode pump 76 is provided midway along the fifth cathode piping 66. Furthermore, a sixth cathode piping 68 is connected to the oil-water separation unit 56. One end of the sixth cathode piping 68 is connected to the oil-water separation unit 56, and the other end is connected to, for example, a drainage tank (not shown). A fifth cathode pump 78 is provided midway along the sixth cathode piping 68.

[0044] The cathode fluid in the cathode fluid tank 52 flows into the cathode chamber 18 from the cathode inlet 30 via the first cathode piping 58 by driving the first cathode pump 70. The first on-off valve 80 is open, allowing the cathode fluid to flow from the cathode fluid tank 52 to the cathode inlet 30. A portion of the cathode fluid in the cathode chamber 18 flows out from the upper cathode outlet 32 ​​to the second cathode piping 60. Another portion of the cathode fluid in the cathode chamber 18 flows out from the lower cathode outlet 34 to the fourth cathode piping 64.

[0045] The lower cathode outlet 34 is disposed below the upper cathode outlet 32. In this embodiment, the upper cathode outlet 32 ​​is connected to a region above half of the cathode chamber 18, and the lower cathode outlet 34 is connected to a region below half of the cathode chamber 18. "Above half" means above the midpoint between the upper and lower ends of the cathode chamber 18, and "below half" means below that midpoint. More preferably, the upper cathode outlet 32 ​​is connected to a region from the upper end of the cathode chamber 18 to one-quarter of the entire cathode chamber 18, and the lower cathode outlet 34 is connected to a region from the lower end to one-quarter of the entire cathode chamber 18.

[0046] As described above, hydrogen gas may be generated at the cathode electrode 14 due to a side reaction. Because hydrogen gas has a lighter specific gravity than the cathode fluid, it accumulates in the upper part of the cathode chamber 18. Therefore, hydrogen gas is discharged from the upper cathode outlet 32 ​​in addition to the cathode fluid. Furthermore, water moves to the cathode electrode 14 from the anode electrode 12 along with protons. Because water has a heavier specific gravity than the cathode fluid, it accumulates in the lower part of the cathode chamber 18. Therefore, water is discharged from the lower cathode outlet 34 in addition to the cathode fluid.

[0047] Fig. 2(A) is a schematic diagram showing an example of the arrangement of the cathode inlet 30, the upper cathode outlet 32, and the lower cathode outlet 34. Fig. 2(B) is a schematic diagram showing another example of the arrangement of the cathode inlet 30, the upper cathode outlet 32, and the lower cathode outlet 34.

[0048] As shown in FIG. 2A , the plate portion 22b according to one example has an upper groove 84 and a lower groove 86 on the surface that defines the cathode chamber 18. The upper groove 84 and the lower groove 86 form a manifold through which the cathode fluid flows. The upper groove 84 and the lower groove 86 extend left and right. The lower groove 86 is disposed below the upper groove 84. For example, the upper groove 84 is disposed in a region above half of the cathode chamber 18, and the lower groove 86 is disposed in a region below half of the cathode chamber 18.

[0049] The cathode inlet 30 and the lower cathode outlet 34 are connected to the lower groove 86. For example, the cathode inlet 30 is connected to one end of the lower groove 86, and the lower cathode outlet 34 is connected to the other end of the lower groove 86. Meanwhile, the upper cathode outlet 32 ​​is connected to the upper groove 84. For example, the upper cathode outlet 32 ​​is connected to the end of the upper groove 84 farther from the cathode inlet 30. Therefore, not only the lower cathode outlet 34 but also the cathode inlet 30 are disposed below the upper cathode outlet 32. In the example shown in FIG. 2(A), the cathode inlet 30 and the lower cathode outlet 34 are connected to the lower groove 86 from the side. Furthermore, the upper cathode outlet 32 ​​is connected to the upper groove 84 from the side. However, this is not limiting, and each inlet and outlet may be connected to each groove from above or below.

[0050] The cathode fluid supplied into the cathode chamber 18 from the cathode inlet 30 flows through the lower groove 86, spreading horizontally, and moving upward within the cathode electrode 14. After passing through the cathode electrode 14, the cathode fluid reaches the upper groove 84 and is discharged to the outside together with hydrogen gas from the upper cathode outlet 32. Furthermore, a portion of the cathode fluid flowing through the lower groove 86 is discharged to the outside together with water from the lower cathode outlet 34 without passing through the cathode electrode 14.

[0051] 2B , the plate portion 22b according to another example has a first groove 88 and a second groove 90 disposed on the left and right sides of the surface defining the cathode chamber 18. The first groove 88 and the second groove 90 form a manifold through which the cathode fluid flows. The first groove 88 and the second groove 90 extend vertically. For example, the first groove 88 is disposed in a region to the right of the half of the cathode chamber 18, and the second groove 90 is disposed in a region to the left of the half of the cathode chamber 18. Alternatively, the first groove 88 may be disposed on the left, and the second groove 90 may be disposed on the right. "Right of the half" means to the right of the midpoint between the left and right ends of the cathode chamber 18, and "left of the half" means to the left of the midpoint. More preferably, the first groove 88 is arranged in a region extending from the side end of the cathode chamber 18 to ¼ of the entire cathode chamber 18, and the second groove 90 is arranged in a region extending from the side end to ¼ of the entire cathode chamber 18.

[0052] The cathode inlet 30 is connected to the first groove 88. For example, the cathode inlet 30 is connected to the lower end of the first groove 88. Meanwhile, the upper cathode outlet 32 ​​and the lower cathode outlet 34 are connected to the second groove 90. For example, the upper cathode outlet 32 ​​is connected to the upper end of the second groove 90, and the lower cathode outlet 34 is connected to the lower end of the second groove 90. Therefore, not only the lower cathode outlet 34 but also the cathode inlet 30 are disposed below the upper cathode outlet 32. Note that in the example shown in FIG. 2(B) , the cathode inlet 30 is connected to the first groove 88 from below. Furthermore, the upper cathode outlet 32 ​​is connected to the second groove 90 from above, and the lower cathode outlet 34 is connected to the second groove 90 from below. However, this is not a limitation, and each inlet and outlet may be connected to each groove from the side.

[0053] The cathode fluid supplied into the cathode chamber 18 from the cathode inlet 30 travels through the first groove 88, spreading vertically, and moving from right to left within the cathode electrode 14. After passing through the cathode electrode 14, the cathode fluid reaches the second groove 90, where a portion of the fluid is discharged to the outside together with hydrogen gas from the upper cathode outlet 32. Another portion is discharged to the outside together with water from the lower cathode outlet 34.

[0054] In both the example shown in FIG. 2(A) and the example shown in FIG. 2(B), the drive rate of the third cathode pump 74 is adjusted so that the discharge rate of the cathode fluid from the lower cathode outlet 34 (e.g., the flow rate of the cathode fluid) is less than the discharge rate of the cathode fluid from the upper cathode outlet 32. This makes the upper cathode outlet 32 ​​the main outlet for the cathode fluid. In the example shown in FIG. 2(A), by making the discharge rate of the lower cathode outlet 34 less than the discharge rate of the cathode fluid from the upper cathode outlet 32, it is possible to reduce the amount of cathode fluid that is discharged to the outside of the cathode chamber 18 without passing through the cathode electrode 14. Furthermore, the cathode fluid is supplied from the cathode inlet 30 located below the upper cathode outlet 32, and the discharge rate of the cathode fluid from the lower cathode outlet 34 is reduced compared to the discharge rate from the upper cathode outlet 32, thereby forming an upflow of the cathode fluid within the cathode chamber 18.

[0055] In the present disclosure, "upflow" of the cathode fluid refers to causing more than half of the cathode fluid that has flowed into the cathode chamber 18 from the cathode inlet 30 located below to be discharged from the upper cathode outlet 32 ​​located above. In other words, "upflow" refers to causing the cathode fluid to flow from below the cathode chamber 18, and making the flow rate (flow velocity) of the cathode fluid at the upper cathode outlet 32 ​​greater than the flow rate of the cathode fluid at the lower cathode outlet 34. Therefore, the shape of the flow path for the cathode fluid within the cathode chamber 18 is not limited. The flow rate F at the upper cathode outlet 32 ​​when current is applied is ｕｐ and the flow rate F at the lower cathode outlet 34 ｄｏｗｎ The ratio of ｕｐ :F ｄｏｗｎ = more than 5: less than 5 to less than 10: more than 0. As an example, by adjusting the drive amount of the third cathode pump 74, 90% of the cathode fluid is discharged from the upper cathode outlet 32, and the remaining 10% is discharged from the lower cathode outlet 34. Note that the ratio of the cathode fluid discharged from the upper cathode outlet 32 ​​and the lower cathode outlet 34 is not limited to 9:1, and can be set appropriately based on experiments, simulations, etc.

[0056] Discharge of the cathode fluid from the cathode chamber 18 may be continuous or intermittent. For example, during steady state, the cathode fluid may be discharged only from the upper cathode outlet 32, and discharge of the cathode fluid from the lower cathode outlet 34 may be carried out at predetermined time intervals. When the cathode fluid is intermittently discharged from the lower cathode outlet 34, discharge of the cathode fluid from the upper cathode outlet 32 ​​may be continued or stopped. However, from the viewpoint of maintaining stable upflow, when discharging the cathode fluid from the lower cathode outlet 34, it is preferable to discharge even a small amount of the cathode fluid from the upper cathode outlet 32 ​​(for example, F in the above ratio). ｕｐ It is preferable to discharge the particles so that the ratio of the total particle size is 3 or more.

[0057] In the present disclosure, the positions of the cathode inlet 30, upper cathode outlet 32, and lower cathode outlet 34 are defined by the positions of the inner ends, i.e., the positions of the openings provided on the inner wall surface of the cathode chamber 18. Therefore, "the lower cathode outlet 34 is located below the upper cathode outlet 32" means that the inner end of the lower cathode outlet 34 is located below the inner end of the upper cathode outlet 32. The upper cathode outlet 32 ​​and the lower cathode outlet 34 may or may not overlap when viewed vertically. In this embodiment, the cathode chamber 18 is partitioned by the diaphragm 20, the plate portion 22b, and the spacer 24b. The cathode inlet 30, the upper cathode outlet 32, and the lower cathode outlet 34 are provided in the plate portion 22b. In this case, the positions of the openings formed on the inner wall surface of the plate portion 22b by the cathode inlet 30, the upper cathode outlet 32, and the lower cathode outlet 34 correspond to the positions of the respective inlets and outlets.

[0058] 2(A) and 2(B), the inlets and outlets extend linearly. Therefore, the outer end of the lower cathode outlet 34, i.e., the opening connected to the outside of the organic hydride manufacturing apparatus 2, is also located lower than the outer end of the upper cathode outlet 32. However, the positions of the outer ends of the outlets are not particularly limited. For example, the upper cathode outlet 32 ​​may be routed downward outside the cathode chamber 18 (e.g., inside the plate portion 22b), so that the outer end of the upper cathode outlet 32 ​​is at the same height as the outer end of the lower cathode outlet 34.

[0059] There may be a plurality of cathode inlets 30, upper cathode outlets 32, and lower cathode outlets 34. When the organic hydride production apparatus 2 has a plurality of upper cathode outlets 32, the plurality of upper cathode outlets 32 may be vertically offset from one another. When the organic hydride production apparatus 2 has a plurality of lower cathode outlets 34, the plurality of lower cathode outlets 34 may be vertically offset from one another. In this case, some of the upper cathode outlets 32 may also function as lower cathode outlets 34 for discharging water. Furthermore, some of the lower cathode outlets 34 may also function as upper cathode outlets 32 for discharging hydrogen gas. Furthermore, two openings arranged vertically may be considered as a combination of an upper cathode outlet 32 ​​and a lower cathode outlet 34, and multiple such combinations may be arranged vertically or horizontally. Furthermore, the cathode inlet 30 may be connected to a groove different from the grooves to which the upper cathode outlet 32 ​​and the lower cathode outlet 34 are connected. That is, a groove dedicated to the cathode inlet 30 may be provided in the plate portion 22b. Also, there may be a plurality of upper grooves 84, lower grooves 86, first grooves 88 and second grooves 90, respectively.

[0060] As shown in FIG. 1 , the cathode fluid and hydrogen gas discharged from the upper cathode outlet 32 ​​flow into the gas-liquid separation unit 54 via the second cathode piping 60. The gas-liquid separation unit 54 separates the hydrogen gas in the cathode fluid from the cathode fluid and discharges it outside the system. The cathode fluid from which the hydrogen gas has been separated flows into the oil-water separation unit 56 via the third cathode piping 62 by driving the second cathode pump 72. The second on-off valve 82 is open, allowing the cathode fluid to flow from the gas-liquid separation unit 54 to the oil-water separation unit 56.

[0061] The cathode fluid and water discharged from the lower cathode outlet 34 flow into the oil-water separation unit 56 via the fourth cathode piping 64 by driving the third cathode pump 74. An upflow of the cathode fluid is formed in the cathode chamber 18, and the amount of the cathode fluid discharged from the lower cathode outlet 34 is less than the amount of the cathode fluid discharged from the upper cathode outlet 32. Therefore, it is highly likely that the cathode fluid discharged from the lower cathode outlet 34 does not contain hydrogen gas, or if it does, the amount is extremely small. Therefore, the cathode fluid discharged from the lower cathode outlet 34 can be sent to the oil-water separation unit 56 without passing through the gas-liquid separation unit 54. Alternatively, the fourth cathode piping 64 may be connected to the gas-liquid separation unit 54, and the cathode fluid discharged from the lower cathode outlet 34 may pass through the gas-liquid separation unit 54.

[0062] The oil-water separator 56 separates the water in the cathode fluid from the cathode fluid. The separated water is discharged to a drain tank via the sixth cathode pipe 68 by driving a fifth cathode pump 78. The cathode fluid from which the water has been separated is returned to the cathode fluid tank 52 via the fifth cathode pipe 66 by driving a fourth cathode pump 76. The cathode fluid tank 52 may also have the function of the oil-water separator 56.

[0063] The cathode fluid supply device 8 of this embodiment circulates the cathode fluid between the cathode chamber 18 and the cathode fluid tank 52. However, the present invention is not limited to this configuration, and the cathode fluid may be sent from the cathode chamber 18 to the outside of the system without being returned to the cathode fluid tank 52.

[0064] The control device 10 controls the supply of power from the power source 4 to the organic hydride manufacturing apparatus 2. The control device 10 also controls the anolyte supply device 6 and the catholyte supply device 8. Specifically, the control device 10 controls the drive of each anode pump and each cathode pump. The control device 10 also controls the opening and closing of the first on-off valve 80 and the second on-off valve 82. The control device 10 is realized as a hardware configuration by elements and circuits such as a computer CPU and memory, and as a software configuration by a computer program, etc., but in FIG. 1 it is depicted as a functional block realized by the cooperation of these elements. It will be naturally understood by those skilled in the art that these functional blocks can be realized in various ways by combining hardware and software.

[0065] As described above, the organic hydride manufacturing apparatus 2 according to this embodiment includes the cathode chamber 18 that houses the cathode electrode 14 that produces organic hydride, the cathode inlet 30 that is connected to the cathode chamber 18 and that supplies external cathode fluid into the cathode chamber 18, the upper cathode outlet 32 ​​that is connected to the cathode chamber 18 and that discharges the cathode fluid and hydrogen gas in the cathode chamber 18 to the outside, and the lower cathode outlet 34 that is connected to the cathode chamber 18 below the upper cathode outlet 32 ​​and that discharges the cathode fluid and water in the cathode chamber 18 to the outside.

[0066] At the cathode electrode 14, a hydrogenation reaction of the material to be hydrogenated occurs as the main reaction, and a hydrogen generation reaction may occur as a side reaction. The occurrence of side reactions leads to a decrease in the faradaic efficiency during organic hydride production. Furthermore, as protons migrate from the anode electrode 12 side to the cathode electrode 14 side, accompanied by water, water accumulates in the cathode chamber 18. Water impedes the flow of the material to be hydrogenated. Therefore, if a large amount of water accumulates in the cathode chamber 18, the amount of material to be hydrogenated supplied to the reaction site of the catalyst layer 14a decreases, making the side reaction more likely to proceed. Furthermore, hydrogen gas generated in the side reaction also impedes the flow of the material to be hydrogenated. Therefore, the hydrogen gas generated in the side reaction further facilitates the side reaction. Therefore, it is desirable to discharge the hydrogen gas and water remaining in the cathode chamber 18 from the cathode chamber 18.

[0067] Hydrogen gas has a lower specific gravity than the material to be hydrided and organic hydrides. On the other hand, water has a higher specific gravity than the material to be hydrided and organic hydrides. Therefore, in a cathode chamber 18 having an opening at the top and one at the bottom, when a flow in which the cathode fluid is supplied from the lower opening and discharged from the upper opening, i.e., an upflow of the cathode fluid, is formed, hydrogen gas is easily discharged from the cathode chamber 18. However, water is difficult to discharge from the cathode chamber 18 and accumulates at the bottom of the cathode chamber 18. Conversely, when a flow in which the cathode fluid is supplied from the upper opening and discharged from the lower opening, i.e., a downflow of the cathode fluid, is formed, water is easily discharged from the cathode chamber 18. However, hydrogen gas is difficult to discharge from the cathode chamber 18 and accumulates at the top of the cathode chamber 18.

[0068] If hydrogen gas accumulates in the cathode chamber 18, the internal pressure of the cathode chamber 18 may increase, potentially causing leakage of the cathode fluid. For this reason, in conventional organic hydride manufacturing apparatuses that have a cathode chamber 18 with two openings, one at the top and one at the bottom, emphasis is placed on exhausting hydrogen gas, and the cathode fluid is constantly supplied to the cathode chamber 18 by an upflow. However, no adequate measures have been taken to deal with water that accumulates in the cathode chamber 18.

[0069] However, in order to improve the faradic efficiency during organic hydride production, water accumulation in the cathode chamber 18 is an issue that cannot be ignored. In contrast, the organic hydride production apparatus 2 of this embodiment is equipped with an upper cathode outlet 32 ​​for discharging the cathode fluid and hydrogen gas in the cathode chamber 18 to the outside, and a lower cathode outlet 34 that is disposed below the upper cathode outlet 32 ​​and for discharging the cathode fluid and water in the cathode chamber 18 to the outside. This makes it possible to simultaneously discharge the hydrogen gas that has accumulated in the upper part of the cathode chamber 18 and the water that has accumulated in the bottom part of the cathode chamber 18. Therefore, according to the organic hydride production apparatus 2 of this embodiment, it is possible to suppress the occurrence of side reactions at the cathode electrode 14, and to further improve the faradic efficiency.

[0070] In particular, the lower the solubility in water of the material to be hydrided and the organic hydride, the more effective the drainage from the lower cathode outlet 34. For example, when the solubility in water of at least one of the material to be hydrided and the organic hydride is preferably 3 g / 100 mL or less, more preferably 2 g / 100 mL or less, drainage from the lower cathode outlet 34 is more effective. Examples of materials to be hydrided and organic hydrides that can be expected to be effective when drained from the lower cathode outlet 34 include benzene (0.18 g / 100 mL H ２ O) and cyclohexane (0.36 g / 100 mL H ２ 0), toluene (0.05 g / 100 mL H ２ O) and methylcyclohexane (1.6 g / 100 mL H ２ O), naphthalene (0.003 g / 100 mL H ２ O) and decahydronaphthalene (0.001 g / 100 mL H ２ O) and the like are exemplified.

[0071] Furthermore, the upper cathode outlet 32 ​​in this embodiment is connected to a region above half of the cathode chamber 18. The lower cathode outlet 34 is connected to a region below half of the cathode chamber 18. This makes it easier to discharge hydrogen gas from the upper cathode outlet 32 ​​and water from the lower cathode outlet 34. This makes it possible to further improve the faradaic efficiency during organic hydride production.

[0072] (Embodiment 2) Embodiment 2 has a configuration that is generally common to Embodiment 1, except for part of the structure of the cathode fluid supply device 8 and the arrangement of the cathode inlet 30, upper cathode outlet 32, and lower cathode outlet 34. Below, the present embodiment will be described, focusing on the configuration that differs from Embodiment 1, and the common configuration will be described briefly or omitted.

[0073] 3 is a schematic diagram of an organic hydride manufacturing system 1 according to embodiment 2. In this embodiment, the connection destination of the fourth cathode piping 64 is different from that in embodiment 1. That is, in embodiment 1, one end of the fourth cathode piping 64 is connected to the lower cathode outlet 34, and the other end is connected to the oil-water separator 56. On the other hand, in this embodiment, one end of the fourth cathode piping 64 is connected to the lower cathode outlet 34, and the other end is connected to the gas-liquid separator 54.

[0074] Fig. 4(A) is a schematic diagram showing an example of the arrangement of the cathode inlet 30, the upper cathode outlet 32, and the lower cathode outlet 34. Fig. 4(B) is a schematic diagram showing another example of the arrangement of the cathode inlet 30, the upper cathode outlet 32, and the lower cathode outlet 34. In this embodiment, the arrangement of the cathode inlet 30 differs from that in Embodiment 1. That is, in Embodiment 1, the cathode inlet 30 is connected below the cathode chamber 18. On the other hand, in this embodiment, the cathode inlet 30 is connected above the cathode chamber 18.

[0075] 4A , the plate portion 22b according to one example has an upper groove 84 and a lower groove 86 on the surface that defines the cathode chamber 18. The upper groove 84 and the lower groove 86 extend left and right. The lower groove 86 is disposed below the upper groove 84. For example, the upper groove 84 is disposed in a region above half of the cathode chamber 18, and the lower groove 86 is disposed in a region below half of the cathode chamber 18.

[0076] The cathode inlet 30 and the upper cathode outlet 32 ​​are connected to the upper groove 84. For example, the cathode inlet 30 is connected to one end of the upper groove 84, and the upper cathode outlet 32 ​​is connected to the other end of the upper groove 84. Meanwhile, the lower cathode outlet 34 is connected to the lower groove 86. For example, the lower cathode outlet 34 is connected to the end of the lower groove 86 farther from the cathode inlet 30. In the example shown in FIG. 4A , each inlet and outlet are connected to each groove from the side. However, this is not limiting, and each inlet and outlet may be connected to each groove from above or below.

[0077] The cathode fluid supplied into the cathode chamber 18 from the cathode inlet 30 advances within the upper groove 84, spreading horizontally, and moving downward within the cathode electrode 14. After passing through the cathode electrode 14, the cathode fluid reaches the lower groove 86 and is discharged together with water from the lower cathode outlet 34 to the outside. Furthermore, a portion of the cathode fluid flowing within the upper groove 84 is discharged together with hydrogen gas from the upper cathode outlet 32 ​​to the outside without passing through the cathode electrode 14.

[0078] 4(B), the plate portion 22b according to another example has a first groove 88 and a second groove 90 arranged on the left and right sides of the surface that defines the cathode chamber 18. The first groove 88 and the second groove 90 extend vertically. For example, the first groove 88 is arranged in a region to the right of half of the cathode chamber 18, and the second groove 90 is arranged in a region to the left of half of the cathode chamber 18. Alternatively, the first groove 88 may be arranged on the left, and the second groove 90 may be arranged on the right.

[0079] The cathode inlet 30 is connected to the first groove 88. For example, the cathode inlet 30 is connected to the upper end of the first groove 88. Meanwhile, the upper cathode outlet 32 ​​and the lower cathode outlet 34 are connected to the second groove 90. For example, the upper cathode outlet 32 ​​is connected to the upper end of the second groove 90, and the lower cathode outlet 34 is connected to the lower end of the second groove 90. In the example shown in FIG. 4B , each inlet and outlet is connected to each groove from above or below. However, this is not limiting, and each inlet and outlet may be connected to each groove from the side.

[0080] The cathode fluid supplied into the cathode chamber 18 from the cathode inlet 30 travels through the first groove 88, spreading vertically, and moving from right to left within the cathode electrode 14. After passing through the cathode electrode 14, the cathode fluid reaches the second groove 90, where a portion of the fluid is discharged to the outside together with hydrogen gas from the upper cathode outlet 32. Another portion is discharged to the outside together with water from the lower cathode outlet 34.

[0081] In both the example shown in FIG. 4(A) and the example shown in FIG. 4(B), the drive amount of the third cathode pump 74 is adjusted so that the discharge amount of the cathode fluid from the lower cathode outlet 34 (e.g., the flow rate of the cathode fluid) is greater than the discharge amount of the cathode fluid from the upper cathode outlet 32. This makes the lower cathode outlet 34 the main outlet for the cathode fluid. In the example shown in FIG. 4(A), by making the discharge amount of the cathode fluid from the upper cathode outlet 32 ​​less than the discharge amount from the lower cathode outlet 34, it is possible to reduce the amount of cathode fluid that is discharged to the outside of the cathode chamber 18 without passing through the cathode electrode 14. In addition, the cathode fluid is supplied from the cathode inlet 30, which is located above the lower cathode outlet 34, and the discharge of the cathode fluid from the lower cathode outlet 34 is promoted more than the discharge from the upper cathode outlet 32, thereby forming a downflow of the cathode fluid within the cathode chamber 18.

[0082] In the present disclosure, the "downflow" of the cathode fluid refers to the process of discharging at least half of the cathode fluid introduced into the cathode chamber 18 from the upper cathode inlet 30 through the lower cathode outlet 34. In other words, the "downflow" refers to introducing the cathode fluid from above the cathode chamber 18, and making the flow rate (flow velocity) of the cathode fluid at the lower cathode outlet 34 greater than the flow rate of the cathode fluid at the upper cathode outlet 32. Therefore, the shape of the flow path for the cathode fluid within the cathode chamber 18 is not limited. The flow rate F at the upper cathode outlet 32 ​​when current is applied is ｕｐ and the flow rate F at the lower cathode outlet 34 ｄｏｗｎ The ratio of ｕｐ :F ｄｏｗｎ = more than 0: less than 10 to less than 5: more than 5. The ratio of the cathode fluid discharged from the upper cathode outlet 32 ​​and the lower cathode outlet 34 can be set appropriately based on experiments, simulations, etc.

[0083] Discharge of the cathode fluid from the cathode chamber 18 may be continuous or intermittent. For example, during steady state, the cathode fluid may be discharged only from the lower cathode outlet 34, and discharge of the cathode fluid from the upper cathode outlet 32 ​​may be carried out at predetermined time intervals. When the cathode fluid is intermittently discharged from the upper cathode outlet 32, discharge of the cathode fluid from the lower cathode outlet 34 may be continued or stopped. However, from the viewpoint of maintaining stable downflow, when discharging the cathode fluid from the upper cathode outlet 32, it is preferable to discharge even a small amount of the cathode fluid from the lower cathode outlet 34 (for example, F in the above ratio). ｄｏｗｎ It is preferable to discharge the particles so that the ratio of the total particle size is 3 or more.

[0084] 3, the cathode fluid and hydrogen gas discharged from the upper cathode outlet 32 ​​flow into the gas-liquid separation unit 54 via the second cathode piping 60. The gas-liquid separation unit 54 separates the hydrogen gas in the cathode fluid from the cathode fluid and discharges it to the outside of the system. The cathode fluid from which the hydrogen gas has been separated flows into the oil-water separation unit 56 via the third cathode piping 62.

[0085] The cathode fluid and water discharged from the lower cathode outlet 34 flow into the gas-liquid separation unit 54 via the fourth cathode piping 64 by driving the third cathode pump 74. After hydrogen gas is removed from the cathode fluid by the gas-liquid separation unit 54, the cathode fluid flows into the oil-water separation unit 56 via the third cathode piping 62. A downflow of the cathode fluid is formed within the cathode chamber 18, and the amount of the cathode fluid discharged from the lower cathode outlet 34 is greater than the amount of the cathode fluid discharged from the upper cathode outlet 32. For this reason, hydrogen gas is likely to be mixed into the cathode fluid discharged from the lower cathode outlet 34. Therefore, in this embodiment, the cathode fluid discharged from the lower cathode outlet 34 is passed through the gas-liquid separation unit 54 before being sent to the oil-water separation unit 56. In addition, if the amount of hydrogen gas generated in the cathode chamber 18 is small due to the design of the organic hydride production system 1, and therefore the possibility of hydrogen gas being discharged from the lower cathode outlet 34 is low, the cathode liquid discharged from the lower cathode outlet 34 may be sent to the oil-water separation section 56 without passing through the gas-liquid separation section 54, as in embodiment 1.

[0086] The oil-water separator 56 separates the water in the cathode fluid from the cathode fluid. The separated water is discharged to a wastewater tank via a sixth cathode pipe 68. The cathode fluid from which the water has been separated is returned to the cathode fluid tank 52 via a fifth cathode pipe 66. The organic hydride manufacturing apparatus 2 according to this embodiment can also achieve the same effects as the organic hydride manufacturing apparatus 2 according to the first embodiment.

[0087] The embodiments of the present invention have been described in detail above. The above-described embodiments merely illustrate specific examples of implementing the present invention. The content of the embodiments does not limit the technical scope of the present invention, and many design modifications, such as changing, adding, or deleting components, are possible within the scope of the inventive concept defined in the claims. A new embodiment with design modifications will combine the effects of the combined embodiments and modifications. In the above-described embodiments, content that allows such design modifications is emphasized by using notations such as "in this embodiment" or "in this embodiment," but design modifications are also permitted even in content without such notation. Any combination of the above-described components is also valid as an aspect of the present invention.

[0088] The embodiments may be specified by the following items: [Item 1] An organic hydride manufacturing apparatus (2) comprising: a cathode chamber (18) accommodating a cathode electrode (14) that hydrogenates a substance to be hydrided in a cathode fluid with protons to produce an organic hydride, a cathode inlet (30) connected to the cathode chamber (18) for supplying an external cathode fluid into the cathode chamber (18), an upper cathode outlet (32) connected to the cathode chamber (18) for discharging the cathode fluid and hydrogen gas in the cathode chamber (18) to the outside, and a lower cathode outlet (34) connected to the cathode chamber (18) below the upper cathode outlet (32) for discharging the cathode fluid and water in the cathode chamber (18) to the outside. [Item 2] The organic hydride production apparatus (2) according to Item 1, wherein the upper cathode outlet (32) is connected to a region above half of the cathode chamber (18), and the lower cathode outlet (34) is connected to a region below half of the cathode chamber (18). [Item 3] The organic hydride production apparatus (2) according to Item 1 or 2, wherein the organic hydride production apparatus (2) comprises a plate portion (22b) having a surface that defines the cathode chamber (18), the plate portion (22b) having an upper groove (84) and a lower groove (86) disposed below the upper groove (84) on the surface, the cathode inlet (30) and the lower cathode outlet (34) being connected to the lower groove (86), and the upper cathode outlet (32) being connected to the upper groove (84). [Item 4] The organic hydride manufacturing apparatus (2) according to Item 1 or 2, further comprising: a plate portion (22b) having a surface that defines a cathode chamber (18); the plate portion (22b) has, on its surface, an upper groove (84) and a lower groove (86) that is disposed below the upper groove (84); the cathode inlet (30) and the upper cathode outlet (32) are connected to the upper groove (84); and the lower cathode outlet (34) is connected to the lower groove (86).[Item 5] The organic hydride manufacturing apparatus (2) according to Item 1 or 2, further comprising: a plate portion (22b) having a surface that defines a cathode chamber (18); the plate portion (22b) has a first groove (88) and a second groove (90) that are disposed on the left and right sides of the surface and extend vertically; the cathode inlet (30) is connected to the first groove (88); and the upper cathode outlet (32) and the lower cathode outlet (34) are connected to the second groove (90). [Item 6] A method for producing an organic hydride, comprising: supplying a cathode chamber (18) containing a cathode electrode (14) that hydrogenates a substance to be hydrogenated in the cathode chamber with protons to produce an organic hydride; discharging the cathode chamber (18) with hydrogen gas from the cathode chamber (18) to the outside; and discharging the cathode chamber (18) with water below the discharge positions of the cathode chamber (18) and the hydrogen gas to the outside.

[0089] The present invention can be used in an organic hydride manufacturing apparatus and an organic hydride manufacturing method.

[0090] 2 organic hydride manufacturing apparatus, 14 cathode electrode, 18 cathode chamber, 22b plate portion, 30 cathode inlet, 32 upper cathode outlet, 34 lower cathode outlet, 84 upper groove, 86 lower groove, 88 first groove, 90 second groove.

Claims

1. a cathode chamber containing a cathode electrode for hydrogenating a substance to be hydrogenated in a cathode solution with protons to produce an organic hydride; a cathode inlet connected to the cathode chamber for supplying the external cathode fluid into the cathode chamber; an upper cathode outlet connected to the cathode chamber for discharging the cathode fluid and hydrogen gas in the cathode chamber to the outside; a lower cathode outlet connected to the cathode chamber below the upper cathode outlet for discharging the cathode fluid and water in the cathode chamber to the outside; Organic hydride production equipment.

2. the upper cathode outlet is connected to a region above half of the cathode chamber; The lower cathode outlet is connected to a region lower than half of the cathode chamber. The organic hydride manufacturing apparatus according to claim 1 .

3. The organic hydride manufacturing apparatus includes a plate portion having a surface that defines the cathode chamber, The plate portion has an upper groove and a lower groove disposed below the upper groove on the surface, the cathode inlet and the lower cathode outlet are connected to the lower groove; The upper cathode outlet is connected to the upper groove.

3. The organic hydride manufacturing apparatus according to claim 1 or 2.

4. The organic hydride manufacturing apparatus includes a plate portion having a surface that defines the cathode chamber, The plate portion has an upper groove and a lower groove disposed below the upper groove on the surface, the cathode inlet and the upper cathode outlet are connected to the upper groove; The lower cathode outlet is connected to the lower groove.

3. The organic hydride manufacturing apparatus according to claim 1 or 2.

5. The organic hydride manufacturing apparatus includes a plate portion having a surface that defines the cathode chamber, the plate portion has a first groove and a second groove disposed on the left and right sides of the surface and extending vertically, the cathode inlet is connected to the first groove; the upper cathode outlet and the lower cathode outlet are connected to the second groove; 3. The organic hydride manufacturing apparatus according to claim 1 or 2.

6. An organic hydride manufacturing apparatus according to claim 1 or 2, An oil-water separation section to which the lower cathode outlet is connected, Organic hydride production system.

7. An organic hydride manufacturing apparatus according to claim 1 or 2, A gas-liquid separation unit to which the lower cathode outlet is connected. Organic hydride production system.

8. An organic hydride manufacturing apparatus comprising: a cathode chamber accommodating a cathode electrode which hydrogenates a substance to be hydrided in a cathode fluid with protons to produce an organic hydride; a cathode inlet connected to the cathode chamber for supplying the external cathode fluid into the cathode chamber; an upper cathode outlet connected to the cathode chamber for discharging the cathode fluid and hydrogen gas in the cathode chamber to the outside; and a lower cathode outlet connected to the cathode chamber below the upper cathode outlet for discharging the cathode fluid and water in the cathode chamber to the outside; A power source for supplying power to the organic hydride manufacturing apparatus; A power supply device that supplies power to the power source. Organic hydride production system.

9. The power supply device is composed of at least one selected from the group consisting of a power generation device that generates power using renewable energy, a system power source, and a power storage device. The organic hydride producing system according to claim 8 .

10. The power supply device is composed of the power generation device and the system power supply, The organic hydride producing system according to claim 9 .

11. supplying the cathode solution to a cathode chamber containing a cathode electrode for hydrogenating a substance to be hydrogenated in the cathode solution with protons to produce an organic hydride; discharging the cathode fluid and hydrogen gas from the cathode chamber to the outside, and discharging the cathode fluid and water from the cathode chamber to the outside below a position where the cathode fluid and hydrogen gas are discharged. Organic hydride production methods.