hydrogen supply system

Abstract

A hydrogen supply system is used to supply hydrogen. The hydrogen supply system includes: a dehydrogenation reaction unit that obtains hydrogen-containing gas by causing a hydride-containing feedstock to undergo a dehydrogenation reaction; and a control unit that controls the hydrogen supply system. When the generation of hydrogen-containing gas in the dehydrogenation reaction unit is stopped, the control unit causes the hydrogen supply unit to supply hydrogen to the dehydrogenation reaction unit. The hydrogen supply unit supplies at least one of the hydrogen-containing gas between the dehydrogenation reaction unit and a gas-liquid separation unit for separating dehydrogenation products from the hydrogen-containing gas, and the hydrogen-containing gas separated by the gas-liquid separation unit for separating dehydrogenation products from the hydrogen-containing gas.

Description

Technical Field

[0001] This disclosure relates to a hydrogen supply system for supplying hydrogen. Background Technology

[0002] Conventional hydrogen supply systems include, for example, the system described in Patent Document 1. The hydrogen supply system of Patent Document 1 comprises: a tank for storing hydrides of aromatic hydrocarbons as raw materials; a dehydrogenation reaction unit for obtaining hydrogen by causing a dehydrogenation reaction of the raw materials supplied from the tank; a gas-liquid separation unit for gas-liquid separation of the hydrogen obtained from the dehydrogenation reaction unit; and a hydrogen purification unit for purifying the hydrogen after gas-liquid separation.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2006-232607 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] In the hydrogen supply system described above, sometimes when the generation of hydrogen-containing gas in the dehydrogenation reaction section has been stopped, the supply of raw materials is stopped and inactive gases such as nitrogen are supplied to the dehydrogenation reaction section. This purges any remaining raw materials in the dehydrogenation reaction section. However, in this method, the dehydrogenation reaction section becomes a high-temperature state without hydrogen, leading to the degradation of the dehydrogenation catalyst due to the formation of coke and the like. On the other hand, if hydrogen is taken from the hydrogen purification unit and supplied to the dehydrogenation reaction section, energy needs to be invested in the hydrogen production unit for hydrogen that is not used as a product. Therefore, it is necessary to suppress the degradation of the dehydrogenation catalyst in the dehydrogenation reaction section and improve the system efficiency of the hydrogen supply system.

[0008] This disclosure was made to solve the above-mentioned problems, and its purpose is to provide a hydrogen supply system that can suppress the deterioration of the dehydrogenation catalyst in the dehydrogenation reaction section and improve the system efficiency as a hydrogen supply system.

[0009] Solution for solving the problem

[0010] To address the aforementioned problems, the hydrogen supply system disclosed herein is used for supplying hydrogen and comprises: a dehydrogenation reaction unit that obtains hydrogen-containing gas by causing a hydride-containing feedstock to undergo a dehydrogenation reaction; and a control unit that controls the hydrogen supply system, wherein the control unit, when stopping the generation of hydrogen-containing gas in the dehydrogenation reaction unit, supplies hydrogen to the dehydrogenation reaction unit, and the hydrogen supply unit supplies at least one of the hydrogen-containing gas between the dehydrogenation reaction unit and a gas-liquid separation unit for separating dehydrogenation products from the hydrogen-containing gas, and the hydrogen-containing gas separated by the gas-liquid separation unit for separating dehydrogenation products from the hydrogen-containing gas.

[0011] In the hydrogen supply system, the dehydrogenation reaction unit obtains hydrogen-containing gas by causing a dehydrogenation reaction in a feedstock containing hydrides. The dehydrogenation reaction is carried out in the dehydrogenation reaction unit while the dehydrogenation catalyst is heated. Here, the control unit supplies hydrogen to the dehydrogenation reaction unit when the generation of hydrogen-containing gas in the dehydrogenation reaction unit is stopped. Thus, even when the reaction is stopped, hydrogen is still present in the dehydrogenation reaction unit. Therefore, it is possible to avoid the deposition of coke on the dehydrogenation catalyst due to the dehydrogenation reaction unit becoming too high and lacking hydrogen. Furthermore, the hydrogen supply unit supplies at least one of the hydrogen-containing gas between the dehydrogenation reaction unit and the gas-liquid separation unit for separating dehydrogenation products from the hydrogen-containing gas, and the hydrogen-containing gas separated from the gas-liquid separation unit for separating dehydrogenation products from the hydrogen-containing gas. In this way, the hydrogen supply unit supplies hydrogen-containing gas upstream of the hydrogen purification unit to the dehydrogenation reaction unit. Therefore, it is not necessary to remove hydrogen from the hydrogen purification unit to suppress the dehydrogenation catalyst degradation in the dehydrogenation reaction unit, thus reducing the energy input to the hydrogen purification unit. The above methods can suppress the deterioration of the dehydrogenation catalyst in the dehydrogenation reaction section and improve the system efficiency as a hydrogen supply system.

[0012] The hydrogen supply unit can supply hydrogen from external sources. In this case, the hydrogen supply unit can supply hydrogen without worrying about the remaining hydrogen reserves in the system.

[0013] The effects of the invention

[0014] According to this disclosure, a hydrogen supply system can be provided that can suppress the deterioration of the dehydrogenation catalyst in the dehydrogenation reaction section and improve the system efficiency as a hydrogen supply system. Attached Figure Description

[0015] Figure 1 This is a block diagram illustrating the structure of a hydrogen supply system according to an embodiment of the present disclosure. Detailed Implementation

[0016] The preferred embodiments of the hydrogen supply system disclosed herein will now be described in detail with reference to the accompanying drawings. In the following description, identical or equivalent parts will be labeled with the same reference numerals, and repeated descriptions will be omitted.

[0017] Figure 1 This is a block diagram illustrating the structure of a hydrogen supply system according to an embodiment of the present disclosure. The hydrogen supply system 100 uses an organic compound (which is liquid at room temperature) as a feedstock. Furthermore, during hydrogen purification, dehydrogenation products (organic compounds (liquid at room temperature)) obtained by dehydrogenating the organic compound (which is liquid at room temperature) used as a feedstock are removed. Examples of organic compounds used as feedstocks include organohydrides. A preferred example of an organohydride is a hydride obtained by reacting hydrogen with aromatic hydrocarbons and produced in large quantities at an oil refinery. Additionally, organohydrides are not limited to aromatic hydrogen compounds, but also include compounds based on the 2-propanol (producing hydrogen and acetone) system. The organohydride can be transported to the hydrogen supply system 100 as a liquid fuel, similar to gasoline, by tank trucks or the like. In this embodiment, methylcyclohexane (hereinafter referred to as MCH) is used as the organohydride. Furthermore, as organic hydrides, hydrides of aromatic hydrocarbons such as cyclohexane, dimethylcyclohexane, ethylcyclohexane, decane, methyldecane, dimethyldecane, and ethyldecane can also be used. Aromatic compounds are preferred examples due to their particularly high hydrogen content. The hydrogen supply system 100 can supply hydrogen to fuel cell vehicles (FCVs) and hydrogen-powered vehicles. It can also be applied to the production of hydrogen from natural gas (mainly composed of methane), LPG (mainly composed of propane), or liquid hydrocarbon feedstocks such as gasoline, naphtha, kerosene, and diesel.

[0018] like Figure 1 As shown, the hydrogen supply system 100 according to this embodiment includes a compression unit 1, a heat exchange unit 2, a dehydrogenation reaction unit 3, a heating unit 4, a gas-liquid separation unit 6, a compression unit 7, and a hydrogen purification unit 8. The compression unit 1, heat exchange unit 2, and dehydrogenation reaction unit 3 belong to a hydrogen production unit 10 for producing hydrogen-containing gas. The gas-liquid separation unit 6, compression unit 7, and hydrogen purification unit 8 belong to a hydrogen purity adjustment unit 11 for improving the purity of hydrogen. The hydrogen supply system 100 also includes lines L1 to L12. Furthermore, in this embodiment, the case where MCH is used as a raw material and the dehydrogenation product removed during hydrogen purification is toluene will be used as an example. In reality, not only toluene but also unreacted MCH and small amounts of byproducts and impurities are present, but in this embodiment, they are considered to be mixed with toluene and exhibit the same behavior as toluene. Therefore, in the following description, the substance referred to as "toluene" also includes unreacted MCH and byproducts.

[0019] Lines L1 to L12 are flow paths for MCH, toluene, hydrogen-containing gas, exhaust gas, high-purity hydrogen, or heating media. Line L1 connects the compression unit 1 to the MCH tank (not shown) to draw MCH from the MCH tank. Line L2 connects the compression unit 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 the 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 the exhaust gas supply destination. Line L8 connects the hydrogen purification unit 8 to a purified gas supply device (not shown). Lines L11 and L12 connect the heating unit 4 to the dehydrogenation reaction unit 3. Lines L11 and L12 allow the flow of heating media.

[0020] The compression unit 1 supplies MCH, which becomes a raw material, to the dehydrogenation reaction unit 3. In addition, MCH transported from outside the hydrogen supply system 100 by tank trucks or the like is stored in MCH tanks. The MCH stored in the MCH tanks is supplied to the dehydrogenation reaction unit 3 via lines L1 and L2 through the compression unit 1.

[0021] Heat exchange unit 2 facilitates heat exchange between MCH flowing in line L2 and hydrogen-containing gas flowing in line L3. The temperature of the hydrogen-containing gas discharged from dehydrogenation reaction unit 3 is higher than the temperature of MCH. Therefore, in heat exchange unit 2, the MCH is heated by the heat of the hydrogen-containing gas. As a result, MCH is supplied to dehydrogenation reaction unit 3 at an increased temperature. In addition, MCH is supplied to dehydrogenation reaction unit 3 together with exhaust gas supplied from hydrogen purification unit 8 via line L7.

[0022] The dehydrogenation reaction unit 3 is a device for obtaining hydrogen by causing a dehydrogenation reaction of MCH. That is, the dehydrogenation reaction unit 3 is a device for removing hydrogen from MCH by using a dehydrogenation catalyst. The dehydrogenation catalyst is not particularly limited; for example, platinum catalysts, palladium catalysts, and nickel catalysts can be selected. These catalysts can also be supported on supports such as alumina, silicon, and titanium dioxide. The reaction of organohydrides is a reversible reaction, and the direction of the reaction changes depending on the reaction conditions (temperature, pressure) (limited by chemical equilibrium). On the other hand, the dehydrogenation reaction is usually an endothermic reaction and a reaction that increases the number of molecules. Therefore, high temperature and low pressure conditions are advantageous. Since the dehydrogenation reaction is an endothermic reaction, heat is supplied to the dehydrogenation reaction unit 3 from the heating unit 4 via a heat medium circulating in lines L11 and L12. The dehydrogenation reaction unit 3 has a mechanism for heat exchange between the MCH flowing through the dehydrogenation catalyst and the heat medium from the heating unit 4. The hydrogen-containing gas extracted from the dehydrogenation reaction unit 3 is supplied to the gas-liquid separation unit 6 via line L3. The hydrogen-containing gas from line L3 is supplied to the gas-liquid separation unit 6 in a mixture containing liquid toluene.

[0023] Heating unit 4 heats the heat medium and supplies it to the dehydrogenation reaction unit 3 via line L11. The heated heat medium returns to heating unit 4 via line L12. The heat medium is not particularly limited and can be oil or the like. Furthermore, heating unit 4 can take any form as long as it can heat the dehydrogenation reaction unit 3. For example, heating unit 4 can directly heat the dehydrogenation reaction unit 3, or it can heat the MCH supplied to the dehydrogenation reaction unit 3 by heating line L2. In addition, heating unit 4 can heat both the dehydrogenation reaction unit 3 and the MCH supplied to the dehydrogenation reaction unit 3. For example, a burner or engine can be used as heating unit 4.

[0024] The gas-liquid separation unit 6 is an apparatus for separating toluene from hydrogen-containing gas. The gas-liquid separation unit 6 is supplied with a hydrogen-containing gas containing toluene as a mixture, and the gas is separated into gaseous hydrogen and liquid toluene. Furthermore, the hydrogen-containing gas supplied to the gas-liquid separation unit 6 is cooled by the heat exchange unit 2. Additionally, the gas-liquid separation unit 6 can be cooled by a cooling medium from a heat source. In this case, the gas-liquid separation unit 6 has a mechanism that enables heat exchange between the hydrogen-containing gas in the gas-liquid separation unit 6 and the cooling medium from the heat source. The toluene separated by the gas-liquid separation unit 6 is supplied to a toluene tank (not shown) via line L4. 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 by the pressure of the compression unit 7. Furthermore, when the hydrogen-containing gas is cooled, a portion of the gas (toluene) can liquefy and be separated from the unliquefied gas (hydrogen) by the gas-liquid separation unit 6. Setting the gas temperature increases the separation efficiency, and increasing the pressure further promotes the liquefaction of toluene.

[0025] The hydrogen purification unit 8 removes dehydrogenation products (toluene in this embodiment) from the hydrogen-containing gas separated by the gas-liquid separation unit 6. Thus, 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. Furthermore, the exhaust gas generated by the hydrogen purification unit 8 is supplied to the dehydrogenation reaction unit 3 via line L7.

[0026] The hydrogen purification unit 8 varies depending on the hydrogen purification method used. Specifically, when membrane separation is used as the hydrogen purification method, the hydrogen purification unit 8 is a hydrogen separation device equipped with a hydrogen separation membrane. Furthermore, when PSA (Pressure Swing Adsorption) or TSA (Temperature Swing Adsorption) is used as the hydrogen purification method, the hydrogen purification unit 8 is an adsorption removal device equipped with multiple adsorption towers for storing adsorbent material used to adsorb impurities.

[0027] The use of membrane separation in the hydrogen purification unit 8 will be explained. In this method, hydrogen-containing gas, pressurized to a predetermined pressure in the compressed section (not shown), is passed through a membrane heated to a predetermined temperature to remove dehydrogenation products, thereby obtaining high-purity hydrogen gas (purified gas). The pressure of the gas that has passed through the membrane is lower than the pressure before passing through the membrane. On the other hand, the pressure of the gas that has not passed through the membrane is approximately the same as the predetermined pressure before passing through the membrane. At this time, the gas that has not passed through the membrane is equivalent to the exhaust gas from the hydrogen purification unit 8.

[0028] The type of membrane used in the hydrogen purification unit 8 is not particularly limited, and porous membranes (membranes that separate by molecular flow, membranes that separate by surface diffusion flow, membranes that separate by capillary condensation, membranes that separate by molecular sieving, etc.) and non-porous membranes can be used. For example, metal membranes (PbAg-based, PdCu-based, Nb-based, etc.), zeolite membranes, inorganic membranes (silicon membranes, carbon membranes, etc.), and polymer membranes (polyimide membranes, etc.) can be used in the hydrogen purification unit 8.

[0029] The PSA method is explained as the removal method used in the hydrogen purification section 8. The adsorbent used in the PSA method has the property of adsorbing toluene contained in 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 setting the adsorption tower to high pressure, the toluene contained in the hydrogen-containing gas is adsorbed and removed by the adsorbent, thereby obtaining high-purity hydrogen (purified gas). When the adsorption capacity of the adsorbent decreases, the toluene adsorbed on the adsorbent is desorbed by setting the adsorption tower to low pressure, and simultaneously, a portion of the purified gas after removal is countercurrently removed from the adsorption tower to remove the desorbed toluene, thereby regenerating the adsorption capacity of the adsorbent. At this time, the hydrogen-containing gas containing at least hydrogen and toluene discharged from the adsorption tower by removing toluene is equivalent to the exhaust gas from the hydrogen purification section 8.

[0030] The TSA method is described as the removal method used in the hydrogen purification section 8. The adsorbent used in the TSA method has the property of adsorbing toluene contained in hydrogen-containing gas at room temperature and desorbing the adsorbed toluene at high temperature. The TSA method utilizes this property of the adsorbent. That is, by setting the adsorption tower to room temperature, the toluene contained in the hydrogen-containing gas is adsorbed and removed by the adsorbent, thereby obtaining high-purity hydrogen (purified gas). When the adsorption capacity of the adsorbent decreases, the toluene adsorbed on the adsorbent is desorbed by setting the adsorption tower to a high temperature, and simultaneously, a portion of the purified gas after removal is countercurrently removed from the adsorption tower to remove the desorbed toluene, thereby regenerating the adsorption capacity of the adsorbent. At this time, the hydrogen-containing gas containing at least hydrogen and toluene discharged from the adsorption tower by removing toluene is equivalent to the exhaust gas from the hydrogen purification section 8.

[0031] Next, the characteristic parts of the hydrogen supply system 100 described above will be explained. For example... Figure 1 As shown, the hydrogen supply system 100 includes a hydrogen supply unit 40 and a control unit 50.

[0032] The hydrogen supply unit 40 supplies hydrogen to the dehydrogenation reaction unit 3. When the generation of hydrogen-containing gas in the dehydrogenation reaction unit 3 is stopped, the control unit 50 supplies hydrogen to the dehydrogenation reaction unit 3 via the hydrogen supply unit 40. Thus, the hydrogen supply unit 40 can introduce hydrogen into the dehydrogenation reaction unit 3 when it is stopped.

[0033] Specifically, the hydrogen supply unit 40 includes: a purge gas line L20 for supplying hydrogen-containing gas between the dehydrogenation reaction unit 3 and the gas-liquid separation unit 6 to the dehydrogenation reaction unit 3; and a valve 51 disposed on the purge gas line L20. The purge gas line L20 branches off from line L3 and extends to line L2.

[0034] Additionally, the hydrogen supply unit 40 includes: a purge gas line L25, which supplies hydrogen-containing gas separated by the gas-liquid separation unit 6 to the dehydrogenation reaction unit 3; and a valve 52 disposed on the purge gas line L25. The purge gas line L25 branches off from line L5 and extends to line L2. Furthermore, the purge gas line L25 may also branch off from line L6.

[0035] Additionally, the hydrogen supply unit 40 includes: a supply unit 55 that supplies hydrogen from outside the hydrogen supply system 100; and a purge gas line L15 that supplies hydrogen from the supply unit 55 to the dehydrogenation reaction unit 3. The purge gas line L15 is connected to line L2. The supply unit 55 is, for example, composed of a hydrogen storage tank and a pump for compressing and transporting hydrogen to the tank.

[0036] Furthermore, the hydrogen supply unit 40 only needs to have at least one of the purge gas line L20 and purge gas line L25. That is, the hydrogen supply unit 40 only needs to have either purge gas line L20 or L25, or it may have both purge gas lines L20 and L25. In addition, the purge gas line L15 is not a necessary component and can be provided as needed or omitted.

[0037] Next, the operation of the control unit 50 will be explained. When the dehydrogenation reaction is stopped, the control unit 50 closes valve 54 of line L2 to stop the supply of raw materials to the dehydrogenation reaction unit 3. During this stage, unreacted raw materials and dehydrogenation products are present in the dehydrogenation reaction unit 3. In this state, the dehydrogenation reaction unit 3 is at a high temperature.

[0038] Next, the control unit 50 controls the hydrogen supply unit 40 to supply hydrogen as a purge gas (in other words, hydrogen used to suppress the dehydrogenation catalyst degradation in the dehydrogenation reaction unit 3) to the dehydrogenation reaction unit 3. Specifically, the control unit 50 opens valve 51, extracts hydrogen-containing gas from between the dehydrogenation reaction unit 3 and the gas-liquid separation unit 6 through the purge gas line L20, and supplies the hydrogen-containing gas to the dehydrogenation reaction unit 3. Alternatively, the control unit 50 opens valve 52, extracts hydrogen-containing gas from the gas-liquid separation unit 6 through the purge gas line L25, and supplies the hydrogen-containing gas to the dehydrogenation reaction unit 3. Alternatively, the control unit 50 activates the supply unit 55 and supplies hydrogen to the dehydrogenation reaction unit 3 via the purge gas line L15. Furthermore, the control unit 50 can supply hydrogen-containing gas via either the purge gas lines L20 or L25, or via both purge gas lines L20 and L25. In addition, the operation of supplying hydrogen-containing gas to the control unit 50 via the purge gas line L15 is not necessary and can be performed as needed.

[0039] Through the above, the hydrogen supply unit 40 can use hydrogen to purge unreacted raw materials and dehydrogenation products remaining in the dehydrogenation reaction unit 3. Here, the hydrogen supplied by the hydrogen supply unit 40 that has passed through the dehydrogenation reaction unit 3 can also be directly discharged outside the system. For example, a discharge line L35 opening to the outside of the system is provided at the upper end of the gas-liquid separation unit 6. The valve 56 can be set to open to discharge the hydrogen that has passed through the dehydrogenation reaction unit 3 from the discharge line L35. Furthermore, after the liquid (unreacted raw materials, dehydrogenation products) in the dehydrogenation reaction unit 3 has been thoroughly purged, a portion or all of the hydrogen that has passed through the dehydrogenation reaction unit 3 can be recycled. In the case of recycling, the hydrogen that has passed through the dehydrogenation reaction unit 3 returns to the dehydrogenation reaction unit 3.

[0040] Regarding the control unit 50, there is no particular limitation on how long the hydrogen supply unit 40 will continue to supply hydrogen after the dehydrogenation reaction unit 3 stops. For example, the control unit 50 may stop the hydrogen supply unit 40 from supplying hydrogen when the temperature of the dehydrogenation reaction unit 3 drops below a predetermined temperature, or it may stop the hydrogen supply unit 40 from supplying hydrogen if a predetermined time has elapsed.

[0041] Furthermore, as described above, the control unit 50 may not need to supply hydrogen from all of the purge gas lines L20, L25, and L15; it may only need to supply hydrogen from at least one of the purge gas lines L20 and L25. Additionally, the control unit 50 may switch which of the purge gas lines L20, L25, and L15 to supply hydrogen based on the timing. For example, the control unit 50 may initially supply hydrogen through purge gas line L20, and when the hydrogen in that section is depleted, supply hydrogen from purge gas line L25, etc. Alternatively, when the hydrogen in purge gas lines L20 and L25 is depleted, the control unit 50 may supply hydrogen through purge gas line L15. Furthermore, if the hydrogen supply unit 40 only has one of the purge gas lines L20 and L25, the switching performed by the control unit 50 as described above may not be necessary.

[0042] Next, the function and effects of the hydrogen supply system 100 involved in this embodiment will be explained.

[0043] In the hydrogen supply system 100, the dehydrogenation reaction unit 3 obtains hydrogen-containing gas by causing a dehydrogenation reaction in a feedstock containing hydrides. The dehydrogenation reaction unit 3 performs the dehydrogenation reaction while the dehydrogenation catalyst is heated. Here, the control unit 50 supplies hydrogen to the dehydrogenation reaction unit 3 when the generation of hydrogen-containing gas in the dehydrogenation reaction unit 3 is stopped. Thus, even when the reaction is stopped, hydrogen is still present in the dehydrogenation reaction unit 3. Therefore, it is possible to prevent coke deposition on the dehydrogenation catalyst due to the dehydrogenation reaction unit 3 becoming hot and lacking hydrogen. Through the above, the deterioration of the dehydrogenation catalyst in the dehydrogenation reaction unit 3 can be suppressed.

[0044] Furthermore, the hydrogen supply unit 40 supplies at least one of the hydrogen-containing gas between the dehydrogenation reaction unit 3 and the gas-liquid separation unit 6 for separating dehydrogenation products from the hydrogen-containing gas, and the hydrogen-containing gas separated by the gas-liquid separation unit 6 for separating dehydrogenation products from the hydrogen-containing gas. In this way, the hydrogen supply unit 40 supplies the dehydrogenation reaction unit 3 with hydrogen-containing gas upstream of the hydrogen purification unit 8. Therefore, it is not necessary to remove hydrogen from the hydrogen purification unit 8 to suppress the dehydrogenation catalyst degradation in the dehydrogenation reaction unit 3, thus reducing the energy input to the hydrogen purification unit 8. Through the above, the degradation of the dehydrogenation catalyst in the dehydrogenation reaction unit 3 can be suppressed, and the system efficiency of the hydrogen supply system 100 can be improved.

[0045] Furthermore, when the hydrogen supply unit 40 supplies hydrogen-containing gas between the dehydrogenation reaction unit 3 and the gas-liquid separation unit 6 to the dehydrogenation reaction unit 3, the hydrogen supply unit 40 can supply hydrogen-containing gas to the dehydrogenation reaction unit 3 before gas-liquid separation, thus improving system efficiency. Additionally, if the gas-liquid separation unit 6 cannot function fully due to a malfunction of the liquid level gauge (such as a rise or fall of the liquid level due to hydrogen leakage), hydrogen-containing gas from the purge gas line L20 can be supplied to the dehydrogenation reaction unit 3.

[0046] Furthermore, when the hydrogen supply unit 40 supplies hydrogen-containing gas separated by the gas-liquid separation unit 6 to the dehydrogenation reaction unit 3, the hydrogen supply unit 40 can also supply the dehydrogenation reaction unit 3 with high-purity hydrogen (hydrogen with a purity higher than that of the hydrogen in the purge gas line L20) after the removal of dehydrogenation products. Therefore, a good balance can be maintained between improving system efficiency and utilizing high-purity hydrogen.

[0047] The hydrogen supply unit 40 can supply hydrogen from an external source. In this case, the hydrogen supply unit 40 can supply hydrogen without worrying about the remaining amount of hydrogen in the system. When the amount of hydrogen is insufficient due to the use of hydrogen-containing gas between the dehydrogenation reaction unit 3 and the gas-liquid separation unit 6, and / or hydrogen-containing gas separated by the gas-liquid separation unit 6, or when the pressure loss increases and it is impossible to supply hydrogen-containing gas to the dehydrogenation reaction unit 3 at the purge gas pressure of purge gas lines L20 and L25, the deterioration of the dehydrogenation catalyst can be effectively suppressed by supplying hydrogen from outside the hydrogen supply system 100. Additionally, hydrogen from outside the hydrogen supply system 100 can also be supplied for initial startup and maintenance.

[0048] This disclosure is not limited to the embodiments described above. For example, in the embodiments described above, a hydrogen supply system for FVC is exemplified, but it could also be a hydrogen supply system for distributed power sources such as household power or non-consumer power.

[0049] As a hydrogen supply unit 40, the hydrogen supply system 100 only needs to have at least one of the purge gas lines L20 and L25.

[0050] Explanation of reference numerals in the attached figures

[0051] 3: Dehydrogenation reaction section; 6: Gas-liquid separation section; 8: Hydrogen purification section; 40: Hydrogen supply section; 50: Control section; 100: Hydrogen supply system.

Claims

1. A hydrogen supply system for supplying hydrogen, comprising: The dehydrogenation reaction unit produces hydrogen-containing gas by causing a dehydrogenation reaction in a feedstock containing hydrides. A hydrogen supply unit that supplies hydrogen to the dehydrogenation reaction unit; and The control unit controls the hydrogen supply system. in, When the control unit stops the generation of hydrogen-containing gas in the dehydrogenation reaction unit, it causes the hydrogen supply unit to supply hydrogen to the dehydrogenation reaction unit. The hydrogen supply unit supplies the hydrogen-containing gas between the dehydrogenation reaction unit and the gas-liquid separation unit for separating the dehydrogenation products from the hydrogen-containing gas to the dehydrogenation reaction unit.

2. The hydrogen supply system according to claim 1, wherein, The hydrogen supply unit also supplies hydrogen from the outside to the dehydrogenation reaction unit.

3. The hydrogen supply system according to claim 2, wherein, The control unit switches between supplying hydrogen-containing gas to the dehydrogenation reaction unit and the gas-liquid separation unit, and supplying hydrogen from the outside to the dehydrogenation reaction unit.

4. The hydrogen supply system according to claim 3, wherein, The hydrogen supply unit also supplies the dehydrogenation reaction unit with the hydrogen-containing gas between the gas-liquid separation unit for separating dehydrogenation products from the hydrogen-containing gas and the first compression unit for supplying the hydrogen-containing gas separated by the gas-liquid separation unit to the supply destination side of the hydrogen supply system. The control unit switches between supplying hydrogen-containing gas between the dehydrogenation reaction unit and the gas-liquid separation unit, supplying hydrogen-containing gas between the gas-liquid separation unit and the first compression unit to the dehydrogenation reaction unit, and supplying hydrogen from the outside to the dehydrogenation reaction unit.

5. The hydrogen supply system according to claim 4, wherein, If the hydrogen-containing gas between the dehydrogenation reaction unit and the gas-liquid separation unit, and between the gas-liquid separation unit and the first compression unit, is depleted, the control unit supplies the external hydrogen to the dehydrogenation reaction unit.

6. The hydrogen supply system according to claim 5, wherein, The gas-liquid separation section is provided with a discharge line that discharges hydrogen from the hydrogen supplied by the hydrogen supply section that has passed through the dehydrogenation reaction section to the outside of the system.

7. The hydrogen supply system according to claim 6, wherein, It also includes a second compression unit that supplies the raw materials to the dehydrogenation reaction unit. When the dehydrogenation reaction is stopped, the control unit closes the valve between the second compression unit and the dehydrogenation reaction unit.

8. The hydrogen supply system according to claim 7, wherein, It also has: A heat exchange section is used for heat exchange between the raw material supplied to the dehydrogenation reaction section and the hydrogen-containing gas obtained through the dehydrogenation reaction; and The heating section heats the dehydrogenation reaction section using a heat medium.

9. The hydrogen supply system according to claim 1, wherein, The hydrogen supply unit also supplies the hydrogen-containing gas between the gas-liquid separation unit for separating dehydrogenation products from the hydrogen-containing gas and the first compression unit for supplying the hydrogen-containing gas separated by the gas-liquid separation unit to the supply destination side of the hydrogen supply system.

10. A control device for controlling a dehydrogenation reaction section for obtaining hydrogen-containing gas by causing a hydride-containing feedstock to undergo a dehydrogenation reaction, and for controlling the hydrogen supply to the dehydrogenation reaction section via a purge gas line. When the generation of hydrogen-containing gas in the dehydrogenation reaction section is stopped, the control device performs the following process: supplies the hydrogen-containing gas between the dehydrogenation reaction section and the gas-liquid separation section from which the dehydrogenation products are separated from the hydrogen-containing gas to the dehydrogenation reaction section via a first purge gas line.

11. The control device according to claim 10, wherein, When the generation of hydrogen-containing gas in the dehydrogenation reaction section is stopped, control is performed to supply hydrogen from the outside to the dehydrogenation reaction section via the third purge gas line.

12. The control device according to claim 11, wherein, When the generation of hydrogen-containing gas in the dehydrogenation reaction section is stopped, control is performed such that hydrogen-containing gas, which is separated from the hydrogen-containing gas and dehydrogenation products, is supplied to the dehydrogenation reaction section via a second purge gas line between a gas-liquid separation section and a first compression section for supplying the hydrogen-containing gas separated from the gas-liquid separation section to the supply destination side for supplying hydrogen. Based on the hydrogen balance in the first and second purge gas lines, control is performed to supply the external hydrogen to the dehydrogenation reaction unit via the third purge gas line.

13. The control device according to claim 11, wherein, When the generation of hydrogen-containing gas in the dehydrogenation reaction section is stopped, control is performed such that hydrogen-containing gas is supplied to the dehydrogenation reaction section via a second purge gas line between a gas-liquid separation section that separates dehydrogenation products from the hydrogen-containing gas and a first compression section that supplies the hydrogen-containing gas separated from the gas-liquid separation section to the supply destination side of the hydrogen supply.

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