A system for stable hydrogen production

Abstract

The utility model relates to the technical field of green hydrogen production from new energy, and in particular to a stable hydrogen production system. A stable hydrogen production system comprises a first organic liquid storage unit, a hydrogenation unit, a second organic liquid storage unit and a dehydrogenation unit which are sequentially connected through pipelines, wherein the dehydrogenation unit is also connected to the first organic liquid storage unit through a pipeline, and further comprises a hydrogen buffer unit which is connected to the dehydrogenation unit through a pipeline. A stable hydrogen production system in the utility model can still provide a relatively stable flow of hydrogen to the downstream when green electricity fluctuates dynamically. A stable hydrogen production system in the utility model can flexibly change the configuration scale of each unit and equipment in the system to achieve the optimal one according to the downstream requirements for green hydrogen stability, project land area, cost control, etc.

Description

Technical Field

[0001] The utility model relates to the technical field of green hydrogen production from new energy, and in particular to a system for stable hydrogen production. Background Art

[0002] Green hydrogen produced by electrolysis using wind and solar power as energy sources, as a green raw material for downstream chemical plants, can significantly reduce carbon emissions in the chemical industry, and is of great significance to promoting the development of green chemistry. However, the instability of renewable energy sources such as wind and solar power has become one of the factors restricting their utilization. CN115459285 discloses a flexible load system for hydrogen production and energy storage, which couples new energy equipment with energy storage equipment, power grid, and hydrogen production equipment, and smoothes the fluctuations in electricity generated by new energy through measures such as charging and discharging of energy storage batteries and power grid replenishment. The hydrogen produced by hydrogen production through new energy power generation also has a large volatility, which is also one of the factors restricting the utilization of green hydrogen, especially when coupled with downstream chemical plants, which often cannot match the stability required in the production process of chemical plants. In view of the high investment in electrochemical energy storage facilities and the increasing number of off-grid new energy power generation and hydrogen production projects, it is necessary to specifically consider the peak-shaving function of the system, and to flexibly regulate between receiving green hydrogen with strong volatility and outputting stable hydrogen logistics, and setting up a green hydrogen storage function for peak-shaving is its main means. At present, the main methods of hydrogen storage include high-pressure gas tank storage and low-temperature liquid storage, but they often have defects such as large floor space, low storage capacity, high pressure resistance, easy leakage, low hydrogen liquefaction temperature, high energy consumption, and high requirements for equipment, instruments, etc. Chemical storage is considered to be a cutting-edge technology for hydrogen storage. CN115838157A discloses a technology for storing and releasing hydrogen, and discloses a hydrogen storage method for reversible hydrogenation of π-conjugated matrix. CN1809505A discloses a hydrogen storage system for storing and releasing hydrogen. The hydrogen storage is completed by hydrogenating lactone into diol, and then releasing hydrogen by dehydrogenating diol to produce lactone. Such methods have the advantages of high hydrogen storage density, low storage cost, and convenient transportation. Utility Model Content

[0003] In view of the above-mentioned shortcomings of the volatility problem of hydrogen production from new energy sources such as wind and photovoltaic power in the prior art, the utility model provides a stable hydrogen production system, which is applied to the field of hydrogen production from wind and photovoltaic power generation, and utilizes a combination of gas hydrogen storage and organic liquid hydrogen storage to cache hydrogen, thereby overcoming the volatility problem of hydrogen production from new energy sources such as wind and photovoltaic power, and can output a relatively stable hydrogen flow to the downstream.

[0004] A system for stable hydrogen production includes a first organic liquid storage unit, a hydrogenation unit, a second organic liquid storage unit and a dehydrogenation unit which are sequentially connected via pipelines, wherein the dehydrogenation unit is also connected to the first organic liquid storage unit via a pipeline, and further includes a hydrogen buffer unit which is connected to the dehydrogenation unit via a pipeline.

[0005] Preferably, the first organic liquid storage unit comprises a first tank body, and the first tank body is connected to the hydrogenation unit and the dehydrogenation unit respectively;

[0006] Preferably, the hydrogenation unit comprises a hydrogen feed compressor;

[0007] Preferably, the hydrogenation unit comprises a circulating hydrogen compressor;

[0008] Preferably, the hydrogenation unit comprises a first heat exchange element;

[0009] Preferably, the hydrogenation unit comprises a hydrogenation reactor;

[0010] Preferably, the hydrogenation unit comprises a reaction heat remover;

[0011] Preferably, the second organic liquid storage unit comprises a second tank body, and the second tank body is connected to the hydrogenation unit and the dehydrogenation unit respectively;

[0012] Preferably, the dehydrogenation unit comprises a dehydrogenation reactor;

[0013] Preferably, the dehydrogenation unit comprises a supplementary heat component;

[0014] Preferably, the dehydrogenation unit comprises a second heat exchange element;

[0015] Preferably, the dehydrogenation unit comprises a gas-liquid separation element;

[0016] Preferably, the dehydrogenation unit comprises a hydrogen compressor;

[0017] Preferably, the dehydrogenation unit comprises a hydrogen purification component;

[0018] Preferably, the hydrogen buffer unit is a pressure tank, and there are multiple pressure tanks.

[0019] Preferably, a hydrogenation catalyst is provided in the hydrogenation reactor;

[0020] Preferably, the first tank is provided with an unsaturated organic liquid;

[0021] Preferably, a saturated organic liquid is provided in the second tank;

[0022] Preferably, a dehydrogenation catalyst is provided in the dehydrogenation reactor;

[0023] Preferably, the hydrogen purification component is one or more of a membrane separation component or a PSA.

[0024] Preferably, the unsaturated organic liquid is selected from one or more of benzene, toluene, ethylcarbazole, and dibenzyltoluene;

[0025] Preferably, the saturated organic liquid is selected from one or more of cyclohexane, methylcyclohexane, dodecahydro-N-ethylcarbazole, and 18-hydrogendibenzyltoluene.

[0026] Preferably, the stable hydrogen production system further comprises a first delivery pump, which is arranged on a pipeline between the first organic liquid storage unit and the hydrogenation unit.

[0027] Preferably, the stable hydrogen production system further comprises a second delivery pump, and the second delivery pump is arranged on a pipeline between the second organic liquid storage unit and the dehydrogenation unit.

[0028] Preferably, the stable hydrogen production system further comprises a hydrogen production unit, and the hydrogen production unit is connected to the hydrogenation unit through a pipeline.

[0029] Preferably, the hydrogen production unit is connected to the hydrogen buffer unit through a pipeline;

[0030] Preferably, the hydrogen production unit is a water electrolysis hydrogen production unit.

[0031] Preferably, the water electrolysis hydrogen production unit comprises an electrolyzer, a gas-liquid separation component and a hydrogen purification component;

[0032] Preferably, the water electrolysis hydrogen production unit adopts one or more of alkaline water electrolysis hydrogen production, proton exchange membrane water electrolysis hydrogen production or solid oxide water electrolysis hydrogen production.

[0033] Preferably, the stable hydrogen production system further comprises a power generation unit, and the power generation unit is connected to the hydrogen production unit; preferably, the power generation unit (9) is a wind-solar power generation unit.

[0034] The utility model has at least one of the following technical effects:

[0035] 1) A stable hydrogen production system in the utility model can still provide a relatively stable flow of hydrogen to the downstream when green electricity fluctuates.

[0036] 2) A stable hydrogen production system in the utility model can flexibly change the configuration type and scale of each unit and equipment in the system to achieve the optimal one according to the downstream requirements for green hydrogen stability, project land area, cost control, etc.

[0037] 3) The utility model is compared with the hydrogen storage method of only setting up a gaseous buffer tank and the green hydrogen output volatility of using an energy storage battery system for green electricity buffering. While outputting a stable hydrogen flow to the downstream, the utility model can greatly reduce the configuration scale of the required gaseous buffer tank, alleviate the continuous fluctuation of the pressure in the tank during operation, reduce the possibility of equipment fatigue operation, and reduce the potential safety hazards in long-term operation. Compared with energy storage batteries, due to the capacity limitation of energy storage batteries, the hydrogen storage equivalent is much smaller than liquid hydrogen storage, and the buffering function of hydrogen is limited.

[0038] 4) Calculate and compare a series of green hydrogen volatility under different volatility requirements and different configuration scales in this system, compare and analyze the requirements for the configuration scale of this system under different volatility requirements, and the impact of the configuration scale of organic liquid hydrogen storage on the required configuration scale of gas storage tanks. The configuration scale of each unit and equipment in this system can be flexibly changed to achieve optimal stability and economy. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 Shown is the structure of a stable hydrogen production system in the utility model Figure 1 .

[0040] Figure 2 It shows the dynamic response curve of the load in Example 1 of the utility model.

[0041] Figure 3 Shown is a graph showing the trend of the number of gas storage tanks changing with the scale of organic liquid processing in Example 1 of the utility model.

[0042] Figure 4 Shown is the dynamic response curve of the load in Example 2 of the present utility model.

[0043] Figure 5 Shown is a graph showing the trend of the number of gas storage tanks changing with the scale of organic liquid processing in Example 2 of the present utility model.

[0044] Figure 6 It shows a schematic diagram of the process of producing green hydrogen by peak shaving and valley filling by batteries in comparative example 1 of the present invention.

[0045] Figure 7 It shows the dynamic response curve of the load in comparative example 1 of the present invention.

[0046] Component number description

[0047] 1. First organic liquid storage unit

[0048] 2 Hydrogenation Unit

[0049] 3. Second organic liquid storage unit

[0050] 4 Dehydrogenation unit

[0051] 5 Hydrogen buffer unit

[0052] 6. First delivery pump

[0053] 7 Second delivery pump

[0054] 8 Hydrogen production unit

[0055] 9 Power generation unit

[0056] 10 Wind and solar power generation system

[0057] 11 Battery System

[0058] 12 Water electrolysis hydrogen production system

[0059] 13 Hydrogen Storage Tank System

[0060] 14 Stable hydrogen system DETAILED DESCRIPTION

[0061] The following is a description of the implementation of the present invention by means of specific embodiments. People familiar with the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification.

[0062] See also Figure 1 It should be noted that the structures, proportions, sizes, etc. illustrated in the drawings in this specification are only used to match the contents disclosed in the specification for people familiar with this technology to understand and read, and are not used to limit the limiting conditions for the implementation of the utility model, so they have no substantial technical significance. Any modification of the structure, change in the proportion relationship, or adjustment of the size should still fall within the scope of the technical content disclosed by the utility model without affecting the effects and purposes that can be achieved by the utility model. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" quoted in this specification are only for the convenience of description, and are not used to limit the scope of the implementation of the utility model. The change or adjustment of their relative relationship should also be regarded as the scope of the implementation of the utility model without substantially changing the technical content.

[0063] like Figure 1 As shown, the utility model provides a system for stable hydrogen production, comprising a first organic liquid storage unit 1, a hydrogenation unit 2, a second organic liquid storage unit 3 and a dehydrogenation unit 4 which are sequentially connected via pipelines, wherein the dehydrogenation unit 4 is also connected to the first organic liquid storage unit 1 via a pipeline, and further comprising a hydrogen buffer unit 5, wherein the dehydrogenation unit 4 is connected to the hydrogen buffer unit 5 via a pipeline.

[0064] In the utility model, the scale of the first organic liquid storage unit 1, the hydrogenation unit 2, the second organic liquid storage unit 3, the dehydrogenation unit 4 and the hydrogen buffer unit 5, as well as the configuration scale of each unit can be flexibly adjusted according to the requirements of the downstream hydrogen-using device for hydrogen stability, the project's restrictions on the land size and other factors. Compared with the installation of energy storage batteries to eliminate the peak of green electricity, it breaks through the limitations of small battery storage capacity and high investment. Compared with complete gaseous hydrogen storage, the scale of the required storage tanks is reduced, and the storage tanks required for organic liquids are at room temperature and pressure and small in size, which improves the safety, stability and economy of the green hydrogen coupling chemical device to produce chemical products.

[0065] In a preferred embodiment, the first organic liquid storage unit 1 includes a first tank body, which is connected to the hydrogenation unit 2 and the dehydrogenation unit 4 respectively, and an unsaturated organic liquid is provided in the first tank body, and the unsaturated organic liquid is selected from one or more of benzene, toluene, ethylcarbazole, and dibenzyltoluene. The second organic liquid storage unit 3 includes a second tank body, which is connected to the hydrogenation unit 2 and the dehydrogenation unit 4 respectively, and a saturated organic liquid is provided in the second tank body, and the saturated organic liquid is selected from one or more of cyclohexane, methylcyclohexane, dodecahydro-N-ethylcarbazole, and 18-hydrogen dibenzyltoluene. The unsaturated organic liquid and the saturated organic liquid in the utility model are not limited to the above unsaturated organic liquid and saturated organic liquid, and other organic liquid systems and compounded organic liquids that can be used for hydrogen storage in the prior art and undergo reversible addition-removal reactions are also acceptable. The first tank body and the second tank body in the utility model belong to liquid storage tanks at normal temperature and pressure, and the volume of a single liquid storage tank can be thousands or tens of thousands of cubic meters.

[0066] In a preferred embodiment, the hydrogenation unit 2 includes a hydrogen feed compressor, the hydrogenation unit 2 includes a circulating hydrogen compressor, the hydrogenation unit 2 includes a first heat exchanger, such as a shell and tube heat exchanger, the hydrogenation unit 2 includes a hydrogenation reactor, and a hydrogenation catalyst is arranged in the hydrogenation reactor, such as a hydrogenation catalyst with a metal or a combination of several metals having hydrogenation activity such as Ni / Ru or precious metals as an active component, and the catalyst used matches the organic liquid system used, so that the unsaturated organic liquid can be selectively hydrogenated to produce a saturated organic liquid. The hydrogenation unit 2 includes a reaction heat transfer device, such as a shell and tube heat exchanger. A hydrogenation reaction occurs in the hydrogenation unit 2, and the temperature range of the hydrogenation reaction is 150-350°C, the pressure range is 0.5-8.0MPa, and the hydrogen storage density of the unsaturated organic liquid is 5.0-7.5wt%.

[0067] In a preferred embodiment, the dehydrogenation unit 4 includes a dehydrogenation reactor, in which a dehydrogenation catalyst is arranged, such as a dehydrogenation catalyst with metals such as Pt, Pd or a combination of several metals as active components, and the dehydrogenation unit 4 includes a heat supplement component, which is used to provide heat for the dehydrogenation reaction in the dehydrogenation unit 4, such as a shell and tube heat exchanger or a heating furnace. The dehydrogenation unit 4 includes a second heat exchange component, which is used to exchange heat for the reaction liquid in the dehydrogenation unit 4, so as to facilitate a more stable dehydrogenation reaction and a better hydrogen peak elimination effect. The second heat exchange component can be a shell and tube heat exchanger. The dehydrogenation unit 4 includes a gas-liquid separation component, such as a gas-liquid separation tank. The dehydrogenation unit 4 includes a hydrogen compressor, and the dehydrogenation unit 4 includes a hydrogen purification component, and the hydrogen purification component is a PSA (pressure swing adsorption system), which is a prior art and can be purchased on the market. The saturated organic liquid coming out of the second organic liquid storage unit 3 undergoes a dehydrogenation reaction under the action of the dehydrogenation catalyst in the dehydrogenation reactor. The temperature range of the dehydrogenation reaction is 150-350°C and the pressure range is 0.1-0.6Mpa. The hydrogen produced by the dehydrogenation reaction is separated by the gas-liquid separation component, compressed by the hydrogen compressor, and purified by the hydrogen purification component to obtain the peak-smoothed hydrogen, which then enters the hydrogen buffer unit 5 for further stabilization. Finally, stable hydrogen is obtained and transported to the downstream hydrogen consumption device. At the same time, the unsaturated organic liquid produced by the dehydrogenation reaction in the dehydrogenation unit 4 enters the first organic liquid storage unit 1. The downstream hydrogen consumption device in the utility model can be coupled with an existing coal-to-methanol and synthetic ammonia device, or it can be a green methanol synthesis, green ammonia synthesis, green oil and green chemicals device.

[0068] In a preferred embodiment, the stable hydrogen production system also includes a first delivery pump 6, which is arranged on a pipeline between the first organic liquid storage unit 1 and the hydrogenation unit 2, and the first delivery pump 6 is used to transport the unsaturated organic liquid in the first tank to the hydrogenation unit 2 for hydrogenation reaction.

[0069] In a preferred embodiment, the stable hydrogen production system further comprises a second delivery pump 7, which is arranged on a pipeline between the second organic liquid storage unit 3 and the dehydrogenation unit 4. The second delivery pump 7 is used to deliver the saturated organic liquid in the second organic liquid storage unit 3 to the dehydrogenation unit 4 for dehydrogenation reaction.

[0070] In a preferred embodiment, the hydrogen production unit 8 is a water electrolysis hydrogen production unit, which includes an electrolyzer, a gas-liquid separation component and a hydrogen purification component. The water electrolysis hydrogen production unit 8 adopts one or more of alkaline water electrolysis hydrogen production, proton exchange membrane water electrolysis hydrogen production or solid oxide water electrolysis hydrogen production.

[0071] In a preferred embodiment, the stable hydrogen production system further comprises a power generation unit 9, which is connected to the hydrogen production unit 8. The power generation unit 9 is an existing technology, such as wind and solar power generation or other new energy electricity as the hydrogen production unit 8 to provide electricity for hydrogen production.

[0072] In a preferred embodiment, the stable hydrogen production system also includes a hydrogen production unit 8, the hydrogen production unit 8 is connected to the hydrogenation unit 2 through a pipeline, the hydrogen production unit 8 is connected to the hydrogen buffer unit 5 through a pipeline, and the hydrogen buffer unit 5 is a pressure tank. In the utility model, the hydrogen coming out of the hydrogen production unit 8 is divided into two routes. The first route is: a part of the fluctuating hydrogen coming out of the hydrogen production unit 8 directly enters the hydrogen buffer unit 5 for stabilization, and then enters the downstream hydrogen consumption device for use. The second route is: another part of the fluctuating hydrogen coming out of the hydrogen production unit 8 first passes through the first organic liquid storage unit 1, the hydrogenation unit 2, the second organic liquid storage unit 3 and the dehydrogenation unit 4 for peak elimination, and then obtains the peak-eliminated hydrogen, and then enters the hydrogen buffer unit 5 for stabilization, and finally enters the downstream hydrogen consumption device for use. In the utility model, the hydrogen storage capacity in the second route accounts for 50-95% of the total hydrogen storage scale (first route hydrogen storage capacity + second route hydrogen storage capacity).

[0073] Specifically, the new energy power generation is transported to the water electrolysis hydrogen production unit, and the water electrolysis produces hydrogen and oxygen. Taking the alkaline electrolyzer as an example, the hydrogen and oxygen produced by the electrolyzer are respectively separated from the gas and liquid and purified and then transported to the downstream at a pressure of 1.5MPa, and oxygen can be used as a by-product. Since the new energy power generation fluctuates with the fluctuation of the weather, the new energy power generation is relatively random. Similarly, the green hydrogen produced by water electrolysis is also fluctuating. When the load of the produced green hydrogen is high, a part of it can be directly transported to the downstream hydrogen consumption device, and the excess hydrogen enters the first organic liquid storage unit 1, the hydrogenation unit 2, the second organic liquid storage unit 3 and the dehydrogenation unit 4, and the unsaturated organic liquid is used to react with hydrogen to produce a saturated organic liquid. The operating load of the hydrogenation unit 2 is 10-110%, and the generated saturated organic liquid is stored in the second storage tank. When the load of hydrogen production by water electrolysis is low, the saturated organic liquid can be sent to the dehydrogenation device for dehydrogenation reaction, and the hydrogen is released from the saturated organic liquid and added to the hydrogen produced by water electrolysis to ensure the stable operation of the downstream hydrogen consumption device. The operating load of the dehydrogenation unit 4 is 10-110%. The hydrogenation unit 2 and the dehydrogenation unit 4 do not operate at the same time. In order to quickly start the hydrogenation and dehydrogenation operations, the hydrogenation unit 2 and the dehydrogenation unit 4 need to be kept warm and pressurized when not in operation. In addition, multiple hydrogen buffer tanks are provided to buffer the hydrogen. Since the hydrogen tanks have a fast adjustment speed for storing and releasing hydrogen, they can meet the needs of short-term and rapid hydrogen adjustment.

[0074] Example 1

[0075] Taking a new energy project as an example, the installed capacity of new energy wind and solar power generation is 500,000 kilowatts, the equivalent working hours are 3,129 hours, the annual power generation is 1.564 billion kWh, the electricity used for hydrogen production is 1.256 billion kWh, the scale of hydrogen production by electrolysis of water is 72,000 Nm3 / h (corresponding to 100% electrolysis load), and multiple electrolyzers are connected in parallel to produce hydrogen. The operating load of a single electrolyzer can be adjusted between 30-110%, and each electrolyzer can be started and stopped independently. The annual hydrogen production capacity is 250 million cubic meters, and a 200,000 tons / year synthetic ammonia unit is configured downstream. The operating load of the green ammonia production unit can be adjusted between 30-110%, and the target annual output of synthetic ammonia is about 120,000 tons.

[0076] The stable hydrogen production system of the utility model includes a first organic liquid storage unit 1, a hydrogenation unit 2, a second organic liquid storage unit 3 and a dehydrogenation unit 4 which are connected in sequence through pipelines, wherein the dehydrogenation unit 4 is connected to the first organic liquid storage unit 1 through a pipeline, and further includes a hydrogen buffer unit 5, wherein the dehydrogenation unit 4 is connected to the hydrogen buffer unit 5 through a pipeline. The first organic liquid storage unit 1 includes a first tank body, which is connected to the hydrogenation unit 2 and the dehydrogenation unit 4 respectively; the hydrogenation unit 2 includes a hydrogen feed compressor; the hydrogenation unit 2 includes a circulating hydrogen compressor; the hydrogenation unit 2 includes a first heat exchanger, which is a shell and tube heat exchanger; the hydrogenation unit 2 includes a hydrogenation reactor; the hydrogenation unit 2 includes a reaction heat transfer device, which is a shell and tube heat exchanger; the second organic liquid storage unit 3 includes a second tank body, which is connected to the hydrogenation unit 2 and the dehydrogenation unit 4 respectively; a hydrogenation catalyst is arranged in the hydrogenation reactor, and the hydrogenation catalyst is Ni / Ru. A hydrogenation reaction occurs in the hydrogenation unit 2, and the temperature range of the hydrogenation reaction is 150-350°C, the pressure range is 0.5-8.0MPa, and the hydrogen storage density of the unsaturated organic liquid is 5.0-7.5wt%. The dehydrogenation unit 4 includes a dehydrogenation reactor, in which a dehydrogenation catalyst is arranged, and the dehydrogenation catalyst is Pt; the dehydrogenation unit 4 includes a heat supplement, and the heat supplement is a shell and tube heat exchanger; the dehydrogenation unit 4 includes a second heat exchange, and the second heat exchange is a shell and tube heat exchanger; the dehydrogenation unit 4 includes a gas-liquid separation component, and the gas-liquid separation component is a gas-liquid separation tank, and the dehydrogenation unit 4 includes a hydrogen compressor; the dehydrogenation unit 4 includes a hydrogen purification component, and the hydrogen purification component is PSA; the hydrogen buffer unit 5 is a pressure tank. The temperature range of the dehydrogenation reaction is 150-350°C, and the pressure range is 0.1-0.6Mpa. The first tank body is provided with an unsaturated organic liquid; the second tank body is provided with a saturated organic liquid, and the unsaturated organic liquid is toluene, and the saturated organic liquid is methylcyclohexane. The stable hydrogen production system also includes a first delivery pump 6, and the first delivery pump 6 is connected to the first organic liquid storage unit 1 and the hydrogenation unit 2 through pipelines. The stable hydrogen production system also includes a second delivery pump 7, which is connected to the second organic liquid storage unit 3 and the dehydrogenation unit 4 through pipelines. The stable hydrogen production system also includes a hydrogen production unit 8, which is connected to the hydrogenation unit 2 through a pipeline. The hydrogen production unit 8 is connected to the hydrogen buffer unit 5 through a pipeline; the hydrogen production unit 8 is a water electrolysis hydrogen production unit. The water electrolysis hydrogen production unit includes an electrolyzer, a gas-liquid separation component and a hydrogen purification component; the water electrolysis hydrogen production unit uses alkaline water electrolysis to produce hydrogen. The stable hydrogen production system also includes a power generation unit 9, which is connected to the hydrogen production unit 8.

[0077] The green hydrogen produced by this hydrogen production system is used as raw material for the downstream ammonia synthesis unit. When the green electricity input for hydrogen production by water electrolysis fluctuates between 0 and 396 MW, the corresponding amount of hydrogen produced by water electrolysis fluctuates between 0 and 79,200 Nm3 / h (corresponding to an electric hydrogen production load of 0 to 110%). The maximum amount of hydrogen that the downstream ammonia synthesis unit can accept is 55,000 Nm3 / h (corresponding to an ammonia synthesis load of 110%).

[0078] The processing capacity of the organic liquid hydrogen storage system configured in this embodiment is 4000Nm3 / h H2. The dynamic response of this system is studied to analyze the hydrogen load output to the downstream and the corresponding scale of the organic liquid hydrogen storage and gas storage tanks required. The results are as follows Figure 2 As shown, after configuring the system in the utility model, the hydrogen produced by water electrolysis is peak-smoothing and valley-filling in the organic liquid hydrogen storage system (i.e., the first organic liquid storage unit 1, the hydrogenation unit 2, the second organic liquid storage unit 3, and the dehydrogenation unit 4), and then enters the hydrogen buffer unit 5 for secondary buffering, and the gas coming out of the hydrogen buffer unit 5 enters the synthetic ammonia unit for green ammonia production. Under this organic liquid hydrogen storage processing capacity, the minimum capacity of the atmospheric pressure storage tanks for unsaturated organic liquid and saturated organic liquid is 215m3 (hydrogen storage equivalent 1.63 million Nm3), and the scale of the gaseous storage tank required is 2.46 million Nm3 (corresponding to 88 1.5MPaG, 15.7m diameter high-pressure spherical tanks).

[0079] The scale of the gaseous storage tanks in the first organic liquid storage unit 1, hydrogenation unit 2, second organic liquid storage unit 3, dehydrogenation unit 4 and hydrogen buffer unit 5 of the system was changed to analyze the scale of the system configuration. The results are shown in Table 1 and Figure 3 As shown, compared with only setting up a gas storage tank, the first organic liquid storage unit 1, the hydrogenation unit 2, the second organic liquid storage unit 3 and the dehydrogenation unit 4 are provided, and the number of gas storage tanks required is less, and it decreases with the increase of the processing scale of the hydrogen storage system (the first organic liquid storage unit 1, the hydrogenation unit 2, the second organic liquid storage unit 3, the dehydrogenation unit 4 and the hydrogen buffer unit 5). However, the organic liquid processing scale continues to increase, and the effect of reducing the required gas storage tank scale decreases. The organic liquid storage tank has a much higher equivalent hydrogen storage density than the gas spherical tank and is stored at room temperature and pressure, so it has little impact on the cost and land occupation. The utility model can optimize the appropriate overall configuration scale according to the actual influencing factors such as the device cost and land use restrictions in the project. In combination with the background of this project, the preferred machine liquid processing capacity is 18000Nm3 / h H2, and 15 gas spherical tanks.

[0080] Table 1 System scale configuration table of Example 1

[0081]

[0082] Note: The organic liquid and organic liquid equivalent hydrogen storage scale in Table 1 refers to the organic liquid and organic liquid equivalent hydrogen storage scale of saturated organic liquid or unsaturated organic liquid (since the scale of saturated organic liquid and unsaturated organic liquid is the same, either one can be used for analysis)

[0083] Example 2

[0084] Compared with Example 1, other conditions remain unchanged. The operating load of the synthetic green ammonia production device in this example can be adjusted between 10-110%. The processing capacity of the currently configured organic liquid hydrogen storage system is 4000Nm 3 / h H2, the dynamic response of this system was studied, the hydrogen load output to the downstream was analyzed, and the corresponding organic liquid storage tank and gas storage tank configuration scale were analyzed. Figure 4 As shown in the figure, after configuring this system, the hydrogen produced by water electrolysis is peak-smoothing and valley-filling in the organic liquid hydrogen storage system, and then enters the gas storage tank (hydrogen buffer unit 5) for secondary buffering. The gas coming out of the gas buffer tank enters the synthetic ammonia unit for green ammonia production. Under this organic liquid hydrogen storage processing capacity, the minimum capacity of the atmospheric pressure storage tank for unsaturated organic liquid and saturated organic liquid is 215m 3 (Hydrogen storage equivalent 1.62 million Nm 3 ) The required gas storage tank size is 540,000 Nm 3 (corresponding to 20 high-pressure spherical tanks with a capacity of 1.5MPaG and a diameter of 15.7m).

[0085] The configuration scale analysis was performed by changing the configuration scale of the first organic liquid storage unit 1, hydrogenation unit 2, second organic liquid storage unit 3, dehydrogenation unit 4 and hydrogen buffer unit 5 of the system. The results are shown in Table 2 and Figure 5 As shown, in this embodiment, the requirements for green hydrogen stability of the downstream ammonia synthesis unit are reduced, and the requirements for hydrogen storage scale are also reduced. However, the trend of reducing the configuration scale adjustment is the same as the previous embodiment. Combined with the background of this project, the organic liquid processing capacity is 4000Nm 3 / h H2, 20 gas spherical tanks.

[0086] Table 2 System scale configuration table of Example 2

[0087]

[0088] Comparative Example 1

[0089] In this comparative example 1, other conditions are the same as those in Example 1, but no organic liquid hydrogen storage system is provided, and battery energy storage is used to eliminate peak loads and fill valleys. The schematic diagram is shown in FIG. Figure 6As shown. The configuration of energy storage batteries for general projects is 10-20% of the installed power generation capacity, and is configured according to 2h capacity. The processing scale of the battery system set in this comparative ratio is 80,000 kW (16% of the installed capacity, equivalent processing capacity 16,000 Nm 3 / h H2), with a total battery capacity of 160,000 kWh (hydrogen storage equivalent of 32,000 Nm 3 ). Figure 7 This is the dynamic response curve of the load under this comparative example. It can be seen from the figure that the battery has a certain buffering effect on green electricity, but the processing scale is similar to 16000Nm 3 / h H2 is the same as the organic liquid hydrogen storage system. Due to the battery capacity, the peak-shaving and valley-filling capabilities are significantly weaker than those of the organic liquid hydrogen storage system. Under this comparative ratio, the scale of the required gas storage tank is 2.82 million Nm 3 , corresponding to about 101 spherical tanks. As shown in Table 1, when only gas buffer tanks are used, the number of spherical tanks required is 109, and the configuration processing capacity is the same as 16000Nm 3 In the case of an organic liquid hydrogen storage system with a capacity of 1.5 MW / h H2, only 24 storage tanks are required.

[0090] It can be seen from the above embodiments and comparative examples that the utility model is a new energy hydrogen production system that can transport hydrogen logistics relatively stably. When green electricity fluctuates, it can still provide a relatively stable flow of hydrogen to the downstream. While the utility model is used to maintain a stable hydrogen output capacity, it can reduce the land occupation by reducing the number of required gas spherical tanks. According to the upstream power generation and the downstream hydrogen use device's demand for output hydrogen stability, actual cost and land use restriction factors, the scale of organic liquid hydrogen storage and gaseous hydrogen storage can be flexibly configured to achieve the best economy and operability.

[0091] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed in the present invention shall still be covered by the claims of the present invention.

Claims

1. A system for stable hydrogen production, characterized in that: The invention comprises a first organic liquid storage unit (1), a hydrogenation unit (2), a second organic liquid storage unit (3) and a dehydrogenation unit (4) which are connected in sequence through pipelines, wherein the dehydrogenation unit (4) is also connected to the first organic liquid storage unit (1) through a pipeline, and further comprises a hydrogen buffer unit (5), wherein the hydrogen buffer unit (5) is connected to the dehydrogenation unit (4) through a pipeline.

2. The system for stable hydrogen production according to claim 1, characterized in that: The first organic liquid storage unit (1) comprises a first tank body, and the first tank body is connected to the hydrogenation unit (2) and the dehydrogenation unit (4) respectively; and / or, the hydrogenation unit (2) comprises a hydrogen feed compressor; and / or, the hydrogenation unit (2) comprises a circulating hydrogen compressor; and / or, the hydrogenation unit (2) comprises a first heat exchange element; and / or, the hydrogenation unit (2) comprises a hydrogenation reactor; and / or, the hydrogenation unit (2) comprises a reaction heat remover; And / or, the second organic liquid storage unit (3) comprises a second tank body, and the second tank body is connected to the hydrogenation unit (2) and the dehydrogenation unit (4) respectively; and / or, the dehydrogenation unit (4) comprises a dehydrogenation reactor; And / or, the dehydrogenation unit (4) comprises a heat supplement component; and / or, the dehydrogenation unit (4) comprises a second heat exchange element; and / or, the dehydrogenation unit (4) comprises a gas-liquid separation element; and / or, the dehydrogenation unit (4) comprises a hydrogen compressor; and / or, the dehydrogenation unit (4) comprises a hydrogen purification component; And / or, the hydrogen buffer unit (5) is a pressure tank.

3. The system for stable hydrogen production according to claim 2, characterized in that: The hydrogenation reactor is provided with a hydrogenation catalyst; And / or, the first tank is provided with an unsaturated organic liquid; And / or, the second tank is provided with a saturated organic liquid; And / or, a dehydrogenation catalyst is provided in the dehydrogenation reactor; And / or, the hydrogen purification component is one or more of a membrane separation component or a PSA.

4. The system for stable hydrogen production according to claim 3, characterized in that: The unsaturated organic liquid is selected from one or more of benzene, toluene, ethylcarbazole and dibenzyltoluene; And / or, the saturated organic liquid is selected from one or more of cyclohexane, methylcyclohexane, dodecahydro-N-ethylcarbazole, and 18-hydrogendibenzyltoluene.

5. The system for stable hydrogen production according to claim 1, characterized in that: The stable hydrogen production system further comprises a first delivery pump (6), wherein the first delivery pump (6) is arranged on a pipeline between the first organic liquid storage unit (1) and the hydrogenation unit (2).

6. The system for stable hydrogen production according to claim 1, characterized in that: The stable hydrogen production system further comprises a second delivery pump (7), wherein the second delivery pump (7) is arranged on a pipeline between the second organic liquid storage unit (3) and the dehydrogenation unit (4).

7. The system for stable hydrogen production according to claim 1, characterized in that: The stable hydrogen production system further comprises a hydrogen production unit (8), and the hydrogen production unit (8) is connected to the hydrogenation unit (2) via a pipeline.

8. The system for stable hydrogen production according to claim 7, characterized in that: The hydrogen production unit (8) is connected to the hydrogen buffer unit (5) through a pipeline; And / or, the hydrogen production unit (8) is a water electrolysis hydrogen production unit.

9. The system for stable hydrogen production according to claim 8, characterized in that: The water electrolysis hydrogen production unit adopts one or more of alkaline water electrolysis hydrogen production, proton exchange membrane water electrolysis hydrogen production or solid oxide water electrolysis hydrogen production.

10. The system for stable hydrogen production according to any one of claims 7 to 9, characterized in that: The stable hydrogen production system further comprises a power generation unit (9), wherein the power generation unit (9) is connected to the hydrogen production unit (8).

11. The system for stable hydrogen production according to claim 10, characterized in that: The power generation unit (9) is a wind-solar power generation unit.

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