Dehydrogenation reaction device

Abstract

To provide a hydrogen supplying system capable of reducing CO2 when hydrogen is produced. To provide a hydrogen supply system.SOLUTION: The hydrogen supply system 100 includes a heating mechanism 20 that heats the dehydrogenation reaction section 3 using electric power. The power supply unit 30 for supplying power to the heating mechanism 20 can supply power based on renewable energy to the heating mechanism 20 (see FIG. 2 b). Thus, the heating mechanism 20 can heat the dehydrogenation reaction unit 3 with electric power based on renewable energy. By using renewable energy, the hydrogen supply system 100 can produce hydrogen without using fossil fuel or with reduced fossil fuel. As described above, by using renewable energy, energy can be effectively used.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a hydrogen supply system that supplies hydrogen. [Background technology]

[0002] Known conventional hydrogen supply systems include, for example, the one disclosed in Patent Document 1. The hydrogen supply system of Patent Document 1 includes a tank for storing a hydride of an aromatic hydrocarbon as a raw material, a dehydrogenation reaction unit for obtaining hydrogen by dehydrogenating the raw material supplied from the tank, a gas-liquid separation unit for separating the hydrogen obtained in the dehydrogenation reaction unit into gas and liquid, and a hydrogen purification unit for purifying the hydrogen obtained by gas-liquid separation. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-232607 Summary of the Invention [Problem to be solved by the invention]

[0004] In the hydrogen supply system described above, the dehydrogenation reaction section dehydrogenates the raw material through an endothermic reaction. Therefore, the hydrogen supply system is equipped with a heating mechanism that heats the dehydrogenation reaction section. Here, energy is required for the heating mechanism to heat the dehydrogenation reaction section. When this occurs, the heating mechanism burns fossil fuels to heat the dehydrogenation reaction section, which generates CO2. There has been a demand for hydrogen supply systems that can reduce CO2 emissions when producing hydrogen.

[0005] The present invention has been made to solve the above-mentioned problems, and has an object to provide a hydrogen supply system that can reduce CO2 emissions when producing hydrogen. [Means for solving the problem]

[0006] In order to solve the above problems, the hydrogen supply system of the present invention is a hydrogen supply system that supplies hydrogen, and includes a dehydrogenation reaction section that obtains a hydrogen-containing gas by dehydrogenating a raw material containing a hydride, a heating mechanism that heats the dehydrogenation reaction section using electricity, and a power supply section that supplies at least one of electricity based on renewable energy and electricity based on thermal power generation with carbon dioxide capture and storage to the heating mechanism.

[0007] The hydrogen supply system includes a heating mechanism that uses electric power to heat the dehydrogenation reaction section. The power supply unit that supplies electric power to this heating mechanism can supply at least one of electric power based on renewable energy and electric power based on thermal power generation with carbon dioxide capture and storage to the heating mechanism. This allows the heating mechanism to heat the dehydrogenation reaction section using electric power based on renewable energy, etc. By using renewable energy, the hydrogen supply system can produce hydrogen without using fossil fuels or with reduced fossil fuel consumption. Furthermore, by using thermal power generation with carbon dioxide capture and storage, the hydrogen supply system can reduce CO2 emissions when obtaining electric power. As a result, CO2 emissions when producing hydrogen can be reduced.

[0008] The power supply unit may include a power storage unit that stores at least one of power generated from renewable energy sources and power generated from thermal power generation with carbon dioxide capture and storage. Unlike energy generated from fossil fuels, power generated from renewable energy sources can be difficult to obtain at the output desired by the user. For example, solar power generation, wind power generation, and hydroelectric power generation are affected by weather and natural conditions. In contrast, the power supply unit includes a power storage unit that stores power. Therefore, the power storage unit can store power when there is a large amount of renewable energy available and the power used by the heating mechanism is low. The power storage unit can then supply the stored power when there is a low amount of available renewable energy. Furthermore, when power generated from thermal power generation with carbon dioxide capture and storage is used, the power supply unit can store power in the power storage unit when the power is readily available (e.g., when electricity is cheap) and supply the stored power when the power is difficult to obtain.

[0009] The hydrogen supply system according to the present invention is a hydrogen supply system that supplies hydrogen, and includes a dehydrogenation reaction section that obtains a hydrogen-containing gas by dehydrogenating a raw material containing a hydride, and a heating mechanism that heats the dehydrogenation reaction section using a heat medium. The dehydrogenation reaction section has a first flow path in which a dehydrogenation catalyst that performs the dehydrogenation reaction is disposed and through which the raw material flows, and a second flow path that is arranged in parallel to the first flow path and through which the heat medium flows. The heating mechanism includes a heat medium supply section that supplies a heat medium to the second flow path of the dehydrogenation reaction section, and a heating section that heats the dehydrogenation catalyst via the heat medium.

[0010] The heating mechanism has a heating section, and thus can supply heat to the dehydrogenation catalyst that performs the endothermic reaction. Here, the dehydrogenation reaction section has a second flow path that is arranged in parallel with the first flow path in which the dehydrogenation reaction is performed by the dehydrogenation catalyst. The heat medium supply section of the heating mechanism supplies a heat medium to the second flow path. Furthermore, the heating section of the heating mechanism heats the dehydrogenation catalyst via the heat medium. The heating mechanism can diffuse the heat from the heating section within the second flow path using the heat medium, thereby heating the dehydrogenation catalyst. Therefore, the heating mechanism can improve the uniformity of heating within the dehydrogenation reaction section. By improving the uniformity of heating in this way, the efficiency of heat utilization is improved, allowing for more effective energy utilization. As a result, CO2 emissions during hydrogen production can be reduced.

[0011] The heating unit may be provided inside the second flow path. In this case, the heating unit is provided in the second flow path that is provided in parallel with the first flow path. Therefore, heat from the heating unit is efficiently transferred to the dehydrogenation catalyst.

[0012] The second flow path may be divided into a plurality of compartments by partition members provided within the second flow path in the first direction in which the second flow path extends. By dividing the second flow path into a plurality of compartments in this manner, the heating mechanism can adjust the heating mode according to the compartment. This improves heat utilization efficiency and enables effective use of energy.

[0013] The heating mechanism may have a plurality of heating units arranged in the second flow path for each of the plurality of compartments. The plurality of heating units can adjust the heating mode for each compartment. This improves heat utilization efficiency and enables effective use of energy.

[0014] The heating mechanism may include a plurality of temperature detectors that detect the respective temperatures of the plurality of compartments. Because the plurality of temperature detectors can detect the temperatures of the respective compartments, the heating mechanism can adjust the heating mode for each compartment based on the detection results. This improves the efficiency of heat utilization and enables effective use of energy.

[0015] The partition member may have an opening at one end in a second direction intersecting the first direction, which allows the heat medium to flow in the first direction. In this case, in one compartment separated by the partition member, the heat medium flows toward the opening toward one end in the second direction and then flows to the other compartment through the opening. In this way, a flow of the heat medium toward the second direction is formed in one compartment, thereby increasing the residence time of the heat medium in that compartment.

[0016] The partition member may seal the spaces between the different compartments, and the heating mechanism may have a plurality of heat medium supply units that supply a heat medium to each of the plurality of compartments. The plurality of heat medium supply units can adjust the supply mode of the heat medium according to each compartment. This improves heat utilization efficiency and enables effective use of energy.

[0017] The hydrogen supply system of the present invention is a hydrogen supply system that supplies hydrogen, and includes a dehydrogenation reaction section that obtains a hydrogen-containing gas by dehydrogenating a raw material containing a hydride, a heating mechanism that uses electric power to heat the dehydrogenation reaction section, and a power supply section that supplies electric power from the grid to the heating mechanism. [Effects of the Invention]

[0018] According to the present invention, it is possible to provide a hydrogen supply system that can reduce CO2 emissions when producing hydrogen. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a block diagram showing a configuration of a hydrogen supply system according to an embodiment of the present invention. [Figure 2] FIG. 2 is a diagram illustrating an example of the configuration of a power supply unit that supplies power to a heating mechanism. [Figure 3] FIG. 2 is a schematic diagram showing the configuration of a dehydrogenation reaction section and a heating mechanism. [Figure 4]FIG. 10 is a schematic diagram showing the configuration of a dehydrogenation reaction section and a heating mechanism of a hydrogen supply system according to a modified example. [Figure 5] FIG. 10 is a schematic diagram showing the configuration of a dehydrogenation reaction section and a heating mechanism of a hydrogen supply system according to a modified example. [Figure 6] FIG. 3 is a diagram showing an example of the arrangement of heaters constituting a heating unit. [Figure 7] FIG. 4 is a diagram illustrating an example of an arrangement of a temperature detection unit. DETAILED DESCRIPTION OF THE INVENTION

[0020] Hereinafter, preferred embodiments of the hydrogen supply system according to the present invention will be described in detail with reference to the drawings. In the following description, the same or corresponding parts will be designated by the same reference numerals, and duplicated explanations will be omitted.

[0021] FIG. 1 is a block diagram showing the configuration of a hydrogen supply system according to an embodiment of the present invention. The hydrogen supply system 100 uses an organic compound (liquid at room temperature) as a raw material. During the hydrogen purification process, the raw organic compound (liquid at room temperature) is dehydrogenated, and a dehydrogenation product (organic compound (liquid at room temperature)) is removed. An example of the organic compound raw material is organic hydride. A suitable example of an organic hydride is a hydride obtained by reacting hydrogen, which is produced in large quantities at refineries, with aromatic hydrocarbons. Organic hydrides are not limited to aromatic hydrogenated compounds; 2-propanol (which produces hydrogen and acetone) is also an example. Organic hydrides can be transported to the hydrogen supply system 100 as a liquid fuel, similar to gasoline, by a tanker truck or the like. In this embodiment, methylcyclohexane (hereinafter referred to as MCH) is used as the organic hydride. Other organic hydrides that can be used include aromatic hydrocarbon hydrides such as cyclohexane, dimethylcyclohexane, ethylcyclohexane, decalin, methyldecalin, dimethyldecalin, and ethyldecalin (aromatic compounds are particularly suitable examples with high hydrogen content). The hydrogen supply system 100 can supply hydrogen to fuel cell vehicles (FCVs) and hydrogen engine vehicles. The system can also be used to produce hydrogen from liquid hydrocarbon feedstocks such as natural gas, which is primarily composed of methane, LPG, which is primarily composed of propane, or gasoline, naphtha, kerosene, and diesel.

[0022] As shown in FIG. 1, a hydrogen supply system 100 according to this embodiment includes a liquid transfer pump 1, a heat exchanger 2, a dehydrogenation reaction unit 3, a heating mechanism 20, a gas-liquid separator 6, a compressor 7, and a hydrogen purifier 8. Among these, the liquid transfer pump 1, the heat exchanger 2, and the dehydrogenation reaction unit 3 belong to a hydrogen production unit 10 that produces a hydrogen-containing gas. The gas-liquid separator 6, the compressor 7, and the hydrogen purifier 8 belong to a hydrogen purity adjuster 11 that increases the purity of hydrogen. The hydrogen supply system 100 also includes lines L1 to L12. This embodiment uses MCH as the raw material and uses toluene as the dehydrogenation product removed during the hydrogen purification process. While in reality, not only toluene but also unreacted MCH and small amounts of by-products and impurities are present, these are mixed with toluene and behave in the same way as toluene in this embodiment. Therefore, in the following description, the term "toluene" also includes unreacted MCH and by-products.

[0023] Lines L1 to L12 are flow paths through which MCH, toluene, hydrogen-containing gas, off-gas, high-purity hydrogen, or a heating medium passes. Line L1 is a line through which liquid transfer pump 1 pumps MCH from an MCH tank (not shown) and connects the liquid transfer pump 1 to the MCH tank. Line L2 connects the liquid transfer pump 1 to the dehydrogenation reaction unit 3. Line L3 connects the dehydrogenation reaction unit 3 to the gas-liquid separation unit 6. Line L4 connects the gas-liquid separation unit 6 to a toluene tank (not shown). Line L5 connects the gas-liquid separation unit 6 to the compression unit 7. Line L6 connects the compression unit 7 to the hydrogen purification unit 8. Line L7 connects the hydrogen purification unit 8 to a supply destination of the off-gas. Line L8 connects the hydrogen purification unit 8 to a purified gas supply device (not shown). The lines L11 and L12 are lines of the heating mechanism 20, and connect the heat medium circulation section 4 and the dehydrogenation reaction section 3. The lines L11 and L12 allow the heat medium to circulate.

[0024] The liquid transfer pump 1 supplies the raw material MCH to the dehydrogenation reaction section 3. The MCH transported from outside by a tank truck or the like is stored in an MCH tank. The MCH stored in the MCH tank is supplied to the dehydrogenation reaction section 3 by the liquid transfer pump 1 via lines L1 and L2.

[0025] The heat exchanger 2 exchanges heat between the MCH flowing through line L2 and the hydrogen-containing gas flowing through line L3. The hydrogen-containing gas coming out of the dehydrogenation reaction section 3 has a higher temperature than the MCH. Therefore, in the heat exchanger 2, the MCH is heated by the heat of the hydrogen-containing gas. As a result, the MCH is supplied to the dehydrogenation reaction section 3 in an elevated temperature state. The MCH is supplied to the dehydrogenation reaction section 3 together with the off-gas supplied from the hydrogen purification section 8 via line L7.

[0026] The dehydrogenation reaction section 3 is a device that obtains hydrogen by dehydrogenating MCH. That is, the dehydrogenation reaction section 3 is a device that extracts hydrogen from MCH through a dehydrogenation reaction using a dehydrogenation catalyst. The dehydrogenation catalyst is not particularly limited and may be selected from, for example, platinum catalysts, palladium catalysts, and nickel catalysts. These catalysts may be supported on a support such as alumina, silica, or titania. The organic hydride reaction is a reversible reaction, and the direction of the reaction changes depending on the reaction conditions (temperature and pressure) (subject to chemical equilibrium constraints). On the other hand, the dehydrogenation reaction is an endothermic reaction that always increases the number of molecules. Therefore, high temperature and low pressure conditions are advantageous. Because the dehydrogenation reaction is an endothermic reaction, heat is supplied to the dehydrogenation reaction section 3 from the heat transfer medium circulating section 4 via a heat transfer medium circulating through lines L11 and L12. The dehydrogenation reaction section 3 has a mechanism that enables heat exchange between the MCH flowing through the dehydrogenation catalyst and the heat transfer medium from the heat transfer medium circulating section 4. The hydrogen-containing gas extracted in the dehydrogenation reaction section 3 is supplied to the gas-liquid separation section 6 via line L3. The hydrogen-containing gas in line L3 is supplied to the gas-liquid separation section 6 in a state where it contains toluene, which is a liquid, as a mixture.

[0027] The heating mechanism 20 supplies the heat medium to the dehydrogenation reaction section 3 via the line L11 by the heat medium circulation section 4. The heating mechanism 20 also heats the circulating heat medium to heat the dehydrogenation reaction section 3. The heated heat medium is returned to the heat medium circulation section 4 via the line L12. The heat medium is not particularly limited, but oil or the like may be used. The detailed configuration of the heating mechanism 20 will be described later.

[0028] The gas-liquid separation unit 6 is a tank that separates toluene from the hydrogen-containing gas. The gas-liquid separation unit 6 separates the hydrogen gas and toluene into gas and liquid by storing the hydrogen-containing gas containing toluene as a mixture. The hydrogen-containing gas supplied to the gas-liquid separation unit 6 is cooled by the heat exchange unit 2. The gas-liquid separation unit 6 may be cooled by a cooling medium from a cold heat source. In this case, the gas-liquid separation unit 6 has a mechanism that allows heat exchange between the hydrogen-containing gas in the gas-liquid separation unit 6 and the cooling medium from the cold heat source. The toluene separated by the gas-liquid separation unit 6 is supplied via line L4 to a toluene underground tank 23 (storage unit) described below. The toluene underground tank 23 will be described later. The hydrogen-containing gas separated by the gas-liquid separation unit 6 is supplied to the hydrogen purification unit 8 via lines L5 and L6 under the pressure of the compression unit 7. When the hydrogen-containing gas is cooled, a portion of the gas (toluene) is liquefied, and the toluene can be separated from the unliquefied gas (hydrogen) by the gas-liquid separation unit 6. The lower the gas temperature, the more efficient the separation becomes, and increasing the pressure further promotes the liquefaction of toluene.

[0029] The hydrogen purification unit 8 removes the dehydrogenation product (toluene in this embodiment) from the hydrogen-containing gas obtained in the dehydrogenation reaction unit 3 and separated into gas and liquid in the gas-liquid separation unit 6. In this way, the hydrogen purification unit 8 purifies the hydrogen-containing gas to obtain high-purity hydrogen (purified gas). The obtained purified gas is supplied to line L8. The off-gas generated in the hydrogen purification unit 8 is supplied to the dehydrogenation reaction unit 3 via line L7.

[0030] The hydrogen purification unit 8 varies depending on the hydrogen purification method used, but specifically, when membrane separation is used as the hydrogen purification method, it is a hydrogen separation device equipped with a hydrogen separation membrane, and when PSA (Pressure Swing Adsorption) or TSA (Temperature Swing Adsorption) is used, it is an adsorption removal device equipped with multiple adsorption towers that store adsorbents that adsorb impurities.

[0031] A case where the hydrogen purification unit 8 uses membrane separation will be described. In this method, a hydrogen-containing gas pressurized to a predetermined pressure by a compression unit (not shown) is passed through a membrane heated to a predetermined temperature, thereby removing dehydrogenation products and obtaining high-purity hydrogen gas (purified gas). The pressure of the permeated gas that has passed through the membrane is reduced compared to the pressure before passing through the membrane. On the other hand, the pressure of the non-permeated gas that has not passed through the membrane is approximately the same as the predetermined pressure before passing through the membrane. In this case, the non-permeated gas that has not passed through the membrane corresponds to the off-gas of the hydrogen purification unit 8.

[0032] There are no particular limitations on the type of membrane used in hydrogen purification unit 8, and porous membranes (those that separate by molecular flow, those that separate by surface diffusion flow, those that separate by capillary condensation, those that separate by molecular sieving, etc.) or non-porous membranes can be used. Examples of membranes that can be used in hydrogen purification unit 8 include metal membranes (PbAg-based, PdCu-based, Nb-based, etc.), zeolite membranes, inorganic membranes (silica membranes, carbon membranes, etc.), and polymer membranes (polyimide membranes, etc.).

[0033] The following describes a case where the PSA method is used as the removal method for the hydrogen purification unit 8. The adsorbent used in the PSA method has the property of adsorbing toluene contained in the hydrogen-containing gas under high pressure and desorbing the adsorbed toluene under low pressure. The PSA method utilizes this property of the adsorbent. That is, by increasing the pressure inside the adsorption tower, the toluene contained in the hydrogen-containing gas is adsorbed onto the adsorbent and removed, resulting in high-purity hydrogen gas (purified gas). If the adsorption function of the adsorbent in the adsorption tower is reduced due to adsorption, the adsorption tower is desorbed by reducing the pressure inside the adsorption tower, and a portion of the removed purified gas is reversed to remove the desorbed toluene from the adsorption tower, thereby regenerating the adsorption function of the adsorbent (at this time, the hydrogen-containing gas containing at least hydrogen and toluene discharged by removing toluene from the adsorption tower corresponds to the off-gas from the hydrogen purification unit 8).

[0034] The following describes a case where the TSA method is used as the removal method for the hydrogen purification unit 8. The adsorbent used in the TSA method has the property of adsorbing toluene contained in the hydrogen-containing gas at room temperature and desorbing the adsorbed toluene at high temperatures. The TSA method utilizes this property of the adsorbent. That is, by maintaining the temperature inside the adsorption tower at room temperature, the toluene contained in the hydrogen-containing gas is adsorbed onto the adsorbent and removed, thereby obtaining high-purity hydrogen gas (high-purity hydrogen). If the adsorption function of the adsorbent inside the adsorption tower is reduced due to adsorption, the adsorption tower is heated to a high temperature to desorb the toluene adsorbed onto the adsorbent, and a portion of the removed high-purity hydrogen is reversed to remove the desorbed toluene from the adsorption tower, thereby regenerating the adsorption function of the adsorbent (at this time, the hydrogen-containing gas containing at least hydrogen and toluene discharged by removing toluene from the adsorption tower corresponds to the off-gas from the hydrogen purification unit 8).

[0035] Next, the characteristic parts of the hydrogen supply system 100 will be described.

[0036] Fig. 2 is a diagram showing an example of the configuration of a power supply unit 30 that supplies power to the heating mechanism 20. Fig. 3 is a conceptual diagram showing an example of the heating mechanism 20. As shown in Fig. 3, the heating mechanism 20 has an electric heater, and can heat the dehydrogenation reaction unit 3 using electric power. Therefore, as shown in Fig. 2, the hydrogen supply system 100 includes a power supply unit 30 that supplies power to the heating mechanism 20.

[0037] The power supply unit 30 shown in FIG. 2(a) is a system capable of efficiently using grid power. The power supply unit 30 includes a power source 31A, a storage battery 33 (power storage unit), a line L21, and a line L22. The power source 31A supplies grid power from the electricity market. The power source 31A can supply power generated by thermal power generation with CCS (Carbon Dioxide Capture and Storage). CCS-enabled thermal power generation uses technology to capture emitted carbon dioxide and store it underground rather than releasing it into the atmosphere. Therefore, CCS-enabled thermal power generation can reduce CO2 emissions compared to conventional thermal power generation. The line L21 connects the power source 31A and the storage battery 33. The power source 31A supplies power to the storage battery 33 via the line L21. The line L21 is provided with a power receiving panel 32 and a PCS 34. Therefore, power from the power source 31A is adjusted by the power receiving panel 32, converted from AC to DC by the PCS 34, and supplied to the storage battery 33. A line L22 connects the storage battery 33 and the heating mechanism 20. The storage battery 33 supplies power to the heating mechanism 20 via the line L22. The line L22 is connected to the PCS 34. Therefore, the power from the storage battery 33 is converted from DC to AC by the PCS 34 and supplied to the heating mechanism 20. For example, when the unit price of electricity in the electricity market is low, the power supply unit 30 stores the power from the power source 31A in the storage battery 33 and uses it in the heating mechanism 20. When the unit price of electricity is high, the power supply unit 30 discharges power from the storage battery 33 and supplies it to the heating mechanism 20. Renewable energy can also be supplied from the power source 31A that uses grid power. Furthermore, the power source 31A using grid power is not limited to power based on thermal power generation with CCS or renewable energy, and may be capable of supplying power based on various power generation methods. Furthermore, the power supply unit 30 may supply power directly from the power receiving panel 32 to the heating mechanism 20.

[0038] The power supply unit 30 shown in FIG. 2(b) is a system capable of supplying power based on renewable energy. The power supply unit 30 includes a power source 31B, a storage battery 33 (power storage unit), a line L21, and a line L22. The power source 31B supplies power based on renewable energy. Renewable energy is energy obtained using natural forces. Examples of power generation methods using renewable energy include solar power generation, hydroelectric power generation, wind power generation, wave power generation, tidal power generation, and geothermal power generation. When using renewable energy, the heating mechanism 20 can produce hydrogen without emitting carbon dioxide or with reduced carbon dioxide emissions, unlike when energy is obtained by burning fossil fuels. The power source 31B supplies power to the storage battery 33 via the line L21. The line L21 is provided with a PCS 34A that adjusts the power immediately after being supplied from the power source 31B, and a PCS 34B that adjusts the power immediately before being supplied to the storage battery 33. Therefore, power from power source 31A is converted from DC to AC by PCS 34A, and then converted from AC to DC by PCS 34B, and then supplied to storage battery 33. Storage battery 33 supplies power to heating mechanism 20 via line L22. Line L22 is connected to PCS 34B. Therefore, power from storage battery 33 is converted from DC to AC by PCS 34B, and then supplied to heating mechanism 20. Power based on renewable energy fluctuates depending on the environment. For example, solar power generation depends on the weather, and therefore the required power is not always available when heating by heating mechanism 20 is required. Therefore, when a large amount of power is available, power supply unit 30 stores power from power source 31B in storage battery 33 and uses it in heating mechanism 20. When power from power source 31B is insufficient, power supply unit 30 discharges power from storage battery 33 and supplies it to heating mechanism 20. The power supply unit 30 may be provided with both the power source 31A based on grid power and the power source 31B based on renewable energy, and may use both of them separately.

[0039] Next, a specific configuration of the heating mechanism 20 will be described in detail with reference to FIG. 3. FIG. 3 is a schematic diagram showing the configuration of the dehydrogenation reaction unit 3 and the heating mechanism 20 according to this embodiment. As shown in FIG. 3, the dehydrogenation reaction unit 3 has a cylindrical dehydrogenation reaction vessel 40. The dehydrogenation reaction vessel 40 includes header sections 41 and 42, an MCH flow path 43 (first flow path), and a heat transfer medium flow path 46 (second flow path). The MCH flow path 43 is a flow path through which a dehydrogenation catalyst 44 for performing a dehydrogenation reaction is disposed and through which MCH flows. The MCH flow path 43 is formed by arranging multiple tubular members in parallel and spaced apart from each other (see, for example, FIGS. 6 and 7). The header section 41 is provided at the inlet end of the MCH flow path 43 formed by multiple tubular members. The header section 41 is connected to a line L2 and distributes the MCH supplied from the line L2 within its internal space. As a result, the header section 41 distributes the MCH to each MCH flow path 43. The header section 41 is provided at the outlet end of the MCH flow path 43, which is made up of a plurality of tubular members. The header section 42 collects the hydrogen-containing gas from each of the MCH flow paths 43 in its internal space and supplies it to line L3.

[0040] The heat medium flow path 46 is provided in parallel to the MCH flow path 43 and is a flow path through which the heat medium flows. The heat medium flow path 46 is formed inside the outer peripheral wall of the dehydrogenation reaction vessel 40. The outer peripheral wall of the dehydrogenation reaction vessel 40 surrounds all of the MCH flow paths 43 from the outer periphery. As a result, the space inside the outer peripheral wall of the dehydrogenation reaction vessel 40 and outside the MCH flow paths 43 is configured as the heat medium flow path 46 (see, for example, FIGS. 6 and 7). Note that in FIGS. 3 to 7, dotted patterns are added to areas where the heat medium is present.

[0041] The heating mechanism 20 includes a heat medium supply unit 25 and a heating unit 21. The heat medium supply unit 25 includes the heat medium circulating unit 4 and lines L11 and L12. The heat medium circulating unit 4 is configured by a pump that pressure-feeds the heat medium. In this embodiment, the supply-side line L11 is provided at the end of the heat medium flow path 46 on the header section 42 side. The recovery-side line L12 is provided at the end of the heat medium flow path 46 on the header section 41 side. Therefore, the heat medium flows through the heat medium flow path 46 in the opposite direction to the flow of the fluid in the MCH flow path 43, i.e., in a counterflow direction.

[0042] A heat medium tank 22 is provided in the line L12. The heat medium tank 22 is provided with a heating unit 21. The heating unit 21 heats the dehydrogenation catalyst 44 via a heat medium. In this embodiment, the heating unit 21 is configured by a heater that generates heat using power supplied from the power supply unit 30. With this configuration, the heat medium is heated by the heating unit 21 in the heat medium tank 22 and supplied to the heat medium flow path 46 via the line L11.

[0043] Here, the heat transfer medium flow path 46 is divided into multiple compartments in the vertical direction (first direction) along which the heat transfer medium flow path 46 extends by partition members 50 provided within the heat transfer medium flow path 46. In this embodiment, the vertical direction corresponds to the axial direction along which the dehydrogenation reactor 40 extends and also corresponds to the direction along which the MCH flow path 43 extends. In this embodiment, the axial direction of the dehydrogenation reactor 40 is parallel to the vertical direction, but the axial direction may be horizontal. The dehydrogenation reactor 40 has multiple partition members 50 arranged to be spaced apart from each other in the vertical direction. The partition members 50 are members that extend in a horizontal direction (second direction) that intersects (here, perpendicular to) the vertical direction. In this embodiment, baffles 51 and 52 are provided as the partition members 50. The baffle 51 has an opening 51a at one end in the horizontal direction that allows the heat transfer medium to flow in the vertical direction. The baffle 52 has an opening 52a on the opposite side from the opening 51a in the horizontal direction. The baffles 51 and 52 are arranged alternately in the up-down direction. Therefore, the heat medium flowing through the heat medium flow path 46 flows in a serpentine manner through the opening 51a of the baffle 51 and the opening 52a of the baffle 52. In each compartment sandwiched between the baffle 51 and the baffle 52, the heat medium flows horizontally along the baffles 51 and 52.

[0044] Next, the operation and effects of the hydrogen supply system 100 according to this embodiment will be described.

[0045] The hydrogen supply system 100 includes a heating mechanism 20 that uses electric power to heat the dehydrogenation reaction section 3. The power supply unit 30 that supplies electric power to the heating mechanism 20 can supply at least one of electric power based on renewable energy and electric power based on thermal power generation with carbon dioxide capture and storage (see FIGS. 2(a) and 2(b)). This allows the heating mechanism 20 to heat the dehydrogenation reaction section 3 with at least one of electric power based on renewable energy and electric power based on thermal power generation with carbon dioxide capture and storage. By using renewable energy, the hydrogen supply system 100 can produce hydrogen without using fossil fuels or with reduced fossil fuel consumption. Furthermore, by using thermal power generation with CCS, the hydrogen supply system 100 can reduce CO2 emissions when obtaining electric power. As a result, CO2 emissions when producing hydrogen can be reduced. Furthermore, when the heating mechanism 20 burns fossil fuel to heat the dehydrogenation reaction section 3, a tank for storing the fossil fuel is required. In contrast to this, the hydrogen supply system 100 according to this embodiment can eliminate the need for (or reduce the size of) a fossil fuel tank.

[0046] The power supply unit 30 may include a storage battery 33 that stores at least one of electricity generated from renewable energy sources and electricity generated from thermal power generation with carbon dioxide capture and storage. Unlike energy generated from fossil fuels, electricity generated from renewable energy sources can be difficult to obtain at a desired output level. For example, solar power generation, wind power generation, and hydroelectric power generation are affected by weather and natural conditions. In contrast, the power supply unit 30 includes a storage battery 33 that stores electricity. Therefore, the storage battery 33 can store electricity when renewable energy is abundant and the electricity used by the heating mechanism 20 is low. The storage battery 33 can then supply the stored electricity when the amount of renewable energy available is low. Furthermore, when electricity generated from thermal power generation with CCS is used, the power supply unit 30 can store electricity in the storage battery 33 when the electricity is readily available (e.g., when electricity is cheap) and supply the stored electricity when the electricity is difficult to obtain.

[0047] The heating mechanism 20 includes a heating unit 21, which allows it to supply heat to the dehydrogenation catalyst 44, which undergoes an endothermic reaction. The dehydrogenation reaction unit 3 includes a heat medium flow path 46, which is arranged in parallel with the MCH flow path 43, where the dehydrogenation reaction is performed by the dehydrogenation catalyst 44. The heat medium supply unit 25 of the heating mechanism 20 supplies a heat medium to the heat medium flow path 46. The heating unit 21 of the heating mechanism 20 heats the dehydrogenation catalyst via the heat medium. The heating mechanism 20 diffuses the heat from the heating unit 21 within the heat medium flow path 46 using the heat medium, thereby heating the dehydrogenation catalyst 44. Therefore, the heating mechanism 20 can improve the uniformity of heating within the dehydrogenation reaction unit 3. This improvement in heating uniformity improves heat utilization efficiency, allowing for more efficient energy utilization. As a result, CO2 emissions during hydrogen production can be reduced.

[0048] The heat medium flow path 46 may be divided into a plurality of compartments in the vertical direction of the heat medium flow path 46 by partition members 50 provided within the heat medium flow path 46. By dividing the heat medium flow path 46 into a plurality of compartments in this manner, the heating mechanism 20 can adjust the heating mode according to the compartment. In this embodiment, the baffles 51 and 52 adjust the flow direction and residence time of the heat medium in each compartment. This improves heat utilization efficiency and enables effective energy utilization.

[0049] The baffle 51 constituting the partition member 50 has an opening 51a at one horizontal end side that allows the heat medium to flow vertically. The baffle 52 constituting the partition member 50 has an opening 52a at the other horizontal end side that allows the heat medium to flow vertically. In this case, in the upstream compartment separated by the baffle 51, the heat medium flows toward the opening 51a toward one horizontal end side and then flows through the opening 51a to the downstream compartment. In this way, a horizontal flow of the heat medium is formed in the compartment upstream of the baffle 51, thereby increasing the residence time of the heat medium in that compartment. In the compartment downstream of the baffle 51, the heat medium flows toward the opening 52a, thereby increasing the residence time of the heat medium in that compartment.

[0050] Because the dehydrogenation reaction is an endothermic reaction, the amount of heat absorbed differs between the inlet, middle, and outlet sections of the MCH flow path 43. Here, the amount of heat absorbed is greater at the inlet section. For example, if a heat transfer medium is supplied from the inlet side, the dehydrogenation catalyst 44 at the inlet side can be sufficiently heated, but the heat transfer capacity of the heat transfer medium may decrease, resulting in insufficient heating of the dehydrogenation catalyst 44 at the outlet side. In contrast, in this embodiment, the heating mechanism 20 supplies the heat transfer medium from the outlet side, counterflowing the fluid in the MCH flow path 43, thereby avoiding the aforementioned lack of heat transfer capacity and improving the conversion rate. The heat transfer medium temperature is preferably set to, for example, 300 to 340°C.

[0051] The present invention is not limited to the above-described embodiments.

[0052] For example, the heating mechanism 20 and the dehydrogenation reaction section 3 shown in FIG. 4 may be employed. In the modified example shown in FIG. 4, the heating mechanism 20 has a plurality of heating sections 21A, 21B, and 21C arranged corresponding to a plurality of (here, three) sections E1, E2, and E3 inside the heat medium flow path 46. Here, the heat medium supply section 25 supplies the heat medium to the heat medium flow path 46 from the header section 41 side and recovers the heat medium from the header section 42 side. The heat medium flow path 46 is provided with a first baffle 51, a first baffle 52, a second baffle 51, and a second baffle 52, in this order from the header section 41 side. Of these, the inlet side section E1 is formed between the first baffle 51 and the first baffle 52. The middle section E2 is formed between the first baffle 52 and the second baffle 51. The outlet side section E3 is formed between the second baffle 51 and the second baffle 52.

[0053] Here, the heaters of the heating units 21 (21A, 21B, 21C) provided in the heat medium flow path 46 are arranged so that the temperature distribution in the horizontal direction of the heat medium flow path 46 is uniform. For example, an arrangement such as that shown in FIG. 6 may be adopted. For example, as shown in FIG. 6(a), when the MCH flow paths 43 are arranged in a predetermined row, the heaters of the heating units 21 may be arranged in the gaps between the rows of the MCH flow paths 43. Furthermore, as shown in FIG. 6(b), the heaters of the heating units 21 may be arranged at a ratio of one heater per multiple rows. Furthermore, as shown in FIG. 6(c), the heaters of the heating units 21 may be folded back once and stretched between the rows of the MCH flow paths 43. Furthermore, as shown in FIG. 6(d), the heaters of the heating units 21 may be folded back multiple times.

[0054] The heating mechanism 20 may also include a plurality of temperature detectors that detect the temperatures of the plurality of sections E1, E2, and E3, respectively. Specifically, as shown in Fig. 7, a temperature detector 56 is disposed in the heat medium flow path 46 for each of the sections E1, E2, and E3. For example, a thermocouple is employed as the temperature detector 56. As shown in Figs. 7(a), (b), and (c), the temperature detectors 56 are disposed at intervals from one another in the horizontal direction so that any uneven flow of the heat medium can be detected.

[0055] As described above, the heating unit 21 is provided inside the heat medium flow path 46. In this case, the heating unit 21 is provided in the heat medium flow path 46 that is provided in parallel with the MCH flow path 43. Therefore, the heat of the heating unit 21 is efficiently transferred to the dehydrogenation catalyst 44.

[0056] The heating mechanism 20 also has a plurality of heating units 21A, 21B, and 21C arranged corresponding to the plurality of sections E1, E2, and E3 inside the heat medium flow path 46. The heating units 21A, 21B, and 21C can adjust the heating mode according to the respective sections E1, E2, and E3. This improves the heat utilization efficiency and enables effective use of energy.

[0057] The heating mechanism 20 includes multiple temperature detectors 56 that detect the respective temperatures of the multiple compartments E1, E2, and E3. Because the multiple temperature detectors 56 can detect the temperatures of the respective compartments E1, E2, and E3, the heating mechanism 20 can adjust the heating mode for each of the compartments E1, E2, and E3 based on the detection results. This improves heat utilization efficiency and enables effective use of energy. As described above, if a heat shortage occurs in compartment E1 due to the large heat absorption capacity of the dehydrogenation catalyst 44 in the inlet-side compartment E1, the heating unit 21 uses the temperature detectors 56 to determine this situation and increase output.

[0058] The heating mechanism 20 and dehydrogenation reaction section 3 shown in FIG. 5 may also be employed. In the modified example shown in FIG. 5, the baffle 53 constituting the partition member 50 blocks the spaces between the different sections E1, E2, and E3. The heating mechanism 20 has a plurality of heat medium supply units 25A, 25B, and 25C that supply a heat medium to each of the sections E1, E2, and E3. The heating mechanism 20 has a plurality of heating units 21A, 21B, and 21C arranged corresponding to each of the sections E1, E2, and E3 within the heat medium flow path 46. The heat medium flow path 46 is provided with a first baffle 51, a first baffle 53, a second baffle 51, a second baffle 53, and a third baffle 51, in this order from the header section 41 side. Of these, the inlet section E1 is formed between the header section 41 and the first baffle 53. The intermediate section E2 is formed between the first baffle 53 and the second baffle 53. The outlet-side compartment E3 is formed between the second baffle 53 and the header section 42. In each of the compartments E1, E2, and E3, the heat medium supply units 25A, 25B, and 25C supply the heat medium from the upper side of the baffle 51 and collect the heat medium from the lower side of the baffle 51. Each of the compartments E1, E2, and E3 is provided with a temperature detection unit 56 as shown in FIG.

[0059] As described above, the baffle 53 constituting the partition member 50 seals the spaces between the different compartments E1, E2, and E3, and the heating mechanism 20 has multiple heat medium supply units 25A, 25B, and 25C that supply heat medium to each of the multiple compartments E1, E2, and E3. The multiple heat medium supply units 25A, 25B, and 25C can adjust the supply mode of the heat medium in accordance with the detection results of the temperature detection units 56 of the respective compartments E1, E2, and E3. This improves heat utilization efficiency and enables effective energy utilization.

[0060] 3 to 5, the heating mechanism 20 heats the dehydrogenation catalyst 44 by supplying the heat medium to the dehydrogenation reaction section 3. Alternatively, or in addition, the heating mechanism 20 may heat the MCH in the line L2 upstream of the dehydrogenation reaction section 3. For example, the line L2 may be provided with a heat exchanger that exchanges heat between the heat medium from the heating mechanism 20 and the MCH.

[0061] The hydrogen supply system is a hydrogen supply system that supplies hydrogen, and may include a dehydrogenation reaction section that obtains a hydrogen-containing gas by dehydrogenating a raw material containing a hydride, a heating mechanism that heats the dehydrogenation reaction section using electric power, and a power supply section that supplies electric power from the grid power to the heating mechanism.

[0062] Additionally, in the above embodiment, a hydrogen station for an FVC is exemplified as the hydrogen supply system, but the hydrogen supply system may also be a hydrogen supply system for a distributed power source such as a household power source or an emergency power source. [Explanation of symbols]

[0063] 3...dehydrogenation reaction section, 20...heating mechanism, 21, 21A, 21B, 21C...heating section, 25, 25A, 25B, 25C...heat medium supply section, 30...power supply section, 33...storage battery (power storage section), 43...MCH flow path (first flow path), 44...dehydrogenation catalyst, 46...heat medium flow path (second flow path), 50...partition member, 51, 52, 53...baffle (partition member), 56...temperature detection section, 100...hydrogen supply system.

Claims

1. A hydrogen supply system that supplies hydrogen, a dehydrogenation reaction section for obtaining a hydrogen-containing gas by dehydrogenating a raw material containing a hydride; a heating mechanism that heats the dehydrogenation reaction section using electric power; a power supply unit that supplies at least one of electricity based on renewable energy and electricity based on thermal power generation with carbon dioxide capture and storage to the heating mechanism.

2. 2. The hydrogen supply system according to claim 1, wherein the power supply unit includes a power storage unit that stores at least one of the power generated from the renewable energy source and the power generated from thermal power generation with carbon dioxide capture and storage.

3. A hydrogen supply system that supplies hydrogen, a dehydrogenation reaction section for obtaining a hydrogen-containing gas by dehydrogenating a raw material containing a hydride; a heating mechanism that heats the dehydrogenation reaction section using a heat medium, The dehydrogenation reaction section is a first flow path in which a dehydrogenation catalyst for performing the dehydrogenation reaction is disposed and through which the raw material flows; a second flow path provided in parallel with the first flow path and through which the heat medium flows, The heating mechanism includes: a heat medium supply unit that supplies the heat medium to the second flow path of the dehydrogenation reaction unit; a heating unit that heats the dehydrogenation catalyst via the heat medium.

4. The hydrogen supply system according to claim 3 , wherein the heating unit is provided inside the second flow path.

5. 5. The hydrogen supply system according to claim 3, wherein the second flow path is divided into a plurality of compartments in a first direction in which the second flow path extends by a partition member provided within the second flow path.

6. 6. The hydrogen supply system according to claim 5, wherein the heating mechanism has a plurality of the heating sections disposed in the second flow path for each of the plurality of compartments.

7. 7. The hydrogen supply system according to claim 5, wherein the heating mechanism comprises a plurality of temperature detectors that detect the temperatures of the plurality of compartments, respectively.

8. 8. A hydrogen supply system as described in any one of claims 5 to 7, wherein the partition member has an opening at one end side in a second direction intersecting the first direction, which allows the heat transfer medium to flow in the first direction.

9. The partition member blocks the spaces between the different compartments, 8. The hydrogen supply system according to claim 5, wherein the heating mechanism includes a plurality of heat medium supply units that supply the heat medium to each of the plurality of compartments.

10. A hydrogen supply system that supplies hydrogen, a dehydrogenation reaction section for obtaining a hydrogen-containing gas by dehydrogenating a raw material containing a hydride; a heating mechanism that heats the dehydrogenation reaction section using electric power; a power supply unit that supplies power from a grid to the heating mechanism.

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