A hydrogen production system and a hydrogen production method

Abstract

The application discloses a hydrogen production system and a hydrogen production method, and belongs to the technical field of hydrogen production. The hydrogen production system comprises a gas distribution unit, a reaction unit and a separation and purification unit. The gas distribution unit comprises a first supply pipeline, a second supply pipeline and a third supply pipeline. The reaction unit comprises a reforming reaction device and a shift reaction device. The first supply pipeline, the second supply pipeline and the third supply pipeline are communicated with the reforming reaction device. The reforming reaction device is configured to enable a hydrocarbon gas and water vapor and carbon dioxide to occur a reforming reaction and output hydrogen, carbon monoxide and unreacted raw materials. The shift reaction device is configured to enable water vapor and carbon monoxide to occur a shift reaction and output hydrogen, carbon dioxide and unreacted raw materials. The separation and purification unit is configured to at least separate hydrogen and carbon dioxide output by the shift reaction and at least output hydrogen and output carbon dioxide to the third supply pipeline. The application reuses carbon dioxide generated in the hydrogen production process, reduces carbon emission in the hydrogen production process and improves hydrogen production.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of hydrogen production, and particularly relates to a hydrogen production system and a hydrogen production method. BACKGROUND

[0002] At present, the hydrogen production technology using natural gas can convert natural gas into hydrogen and be used to drive hydrogen fuel cells or supply other hydrogen energy equipment, so as to further reduce the emissions and environmental pollution of traditional fuel transportation modes.

[0003] However, most of the natural gas hydrogen production systems are steam reforming of natural gas and water to produce hydrogen, and carbon dioxide is generated in the hydrogen production process, and the emission of carbon dioxide causes the accumulation of greenhouse effect. Although it can be separated from the synthesis gas by separation, the storage and sequestration of carbon dioxide is still a problem, which increases the cost of the whole system. SUMMARY

[0004] The application aims to provide a hydrogen production system to solve the above technical problems, and another purpose of the application is to provide a hydrogen production method using the above hydrogen production system.

[0005] Technical scheme: The hydrogen production system provided by the application comprises:

[0006] The gas distribution unit comprises a first supply pipeline, a second supply pipeline and a third supply pipeline, the first supply pipeline is configured to supply water vapor, the second supply pipeline is configured to supply hydrocarbon gas, and the third supply pipeline is configured to supply carbon dioxide;

[0007] The reaction unit comprises a reforming reaction device and a shift reaction device, the first supply pipeline, the second supply pipeline and the third supply pipeline are communicated with the reforming reaction device, the shift reaction device is communicated with the reforming reaction device, the reforming reaction device is configured to enable the hydrocarbon gas and the water vapor, the hydrocarbon gas and the carbon dioxide to respectively undergo a reforming reaction and output hydrogen, carbon monoxide and unreacted raw materials to the shift reaction device, and the shift reaction device is configured to enable the water vapor and the carbon monoxide to undergo a shift reaction and output hydrogen, carbon dioxide and unreacted raw materials;

[0008] The separation and purification unit is communicated with the shift reaction device, and the separation and purification unit is configured to at least separate the hydrogen and the carbon dioxide output by the shift reaction, and at least output the hydrogen and output the carbon dioxide to the third supply pipeline.

[0009] In some embodiments, the gas distribution unit further comprises a mixing pipeline and a preheating mixing device communicating with the mixing pipeline, the first supply pipeline, the second supply pipeline and the third supply pipeline communicate with the mixing pipeline and communicate with the reforming reaction device through the preheating mixing device.

[0010] In some embodiments, the reaction unit further comprises a first heat exchange device connected between the reforming reaction device and the shift reaction device to adjust the temperature of the gas output by the reforming reaction device to the shift reaction device.

[0011] In some embodiments, the separation and purification unit comprises a first pressure swing adsorption device communicating with the shift reaction device, the first pressure swing adsorption device is configured to separate carbon dioxide in the gas output by the shift reaction device and output other gas while delivering the carbon dioxide to the third supply pipeline.

[0012] In some embodiments, the separation and purification unit further comprises a second pressure swing adsorption device communicating with the first pressure swing adsorption device for input of the other gas, the second pressure swing adsorption device is configured to separate hydrogen in the other gas.

[0013] In some embodiments, the separation and purification unit further comprises a second heat exchange device connected between the shift reaction device and the first pressure swing adsorption device, the second heat exchange device is configured to separate water vapor in the gas output by the shift reaction device and deliver other gas to the first pressure swing adsorption device.

[0014] In some embodiments, the second heat exchange device comprises an outer tank and an inner tank arranged in the outer tank, the inner tank has a gas inlet cavity therein, the inner tank is connected with a gas inlet pipe, a gas outlet pipe and a drain pipe, the gas inlet pipe, the gas outlet pipe and the drain pipe respectively communicate with the gas inlet cavity, a cooling water cavity is formed between the inner tank and the outer tank, the outer tank is respectively provided with a water inlet communicating with the cooling water cavity and a water outlet, the water inlet is used for input of cooling water, and the water outlet is used for discharge of the cooling water.

[0015] The gas inlet pipe communicates with the shift reaction device for input of the gas output by the shift reaction device into the gas inlet cavity, and the drain pipe is provided with a drain valve to control discharge of condensed water in the gas inlet cavity.

[0016] In some embodiments, a plurality of baffles are arranged in the inner tank in sequence along the rising direction of the condensed water level in the gas inlet cavity, and adjacent baffles are staggered in directions intersecting the rising direction of the level.

[0017] The air inlet pipe has an air inlet end communicating with the air inlet cavity, and the air outlet pipe has an air outlet end communicating with the air inlet cavity;

[0018] The air inlet end and the air outlet end are respectively located on opposite sides of the plurality of baffles in the liquid level rising direction; and / or,

[0019] The water inlet is closer to the air inlet end than the water outlet.

[0020] In some embodiments, the hydrogen production system further comprises an analysis unit, the analysis unit comprising a chromatographic analysis device, a first shunt branch pipe, a first pressure reducing valve arranged on the first shunt branch pipe, and a third heat exchange device, one end of the first shunt branch pipe communicating with a gas output end of the reforming reaction device, the other end of the first shunt branch pipe communicating with the third heat exchange device, the third heat exchange device communicating with the chromatographic analysis device, the third heat exchange device being configured to reduce the temperature of the gas output by the reforming reaction device and input the chromatographic analysis device, and the chromatographic analysis device being configured to analyze the components of the input gas.

[0021] In some embodiments, the hydrogen production system further comprises an analysis unit, the analysis unit comprising a chromatographic analysis device, a second shunt branch pipe, and a second pressure reducing valve arranged on the second shunt branch pipe, one end of the second shunt branch pipe communicating with an other gas output end of the second heat exchange device, the other end of the second shunt branch pipe communicating with the chromatographic analysis device, and the chromatographic analysis device being configured to analyze the components of the input gas.

[0022] In some embodiments, the hydrogen production system further comprises an analysis unit, the analysis unit comprising a chromatographic analysis device and a third shunt branch pipe, one end of the third shunt branch pipe communicating with a hydrogen output end of the second pressure swing adsorption device, the other end of the third shunt branch pipe communicating with the chromatographic analysis device, and the chromatographic analysis device being configured to analyze the purity of the input hydrogen.

[0023] Correspondingly, a hydrogen production method according to an embodiment of the present application is applied to the hydrogen production system described above, and comprises the following steps:

[0024] hydrocarbon gas, water vapor, and carbon dioxide are respectively input into the reforming reaction device through the first supply pipeline, the second supply pipeline, and the third supply pipeline;

[0025] hydrocarbon gas and water vapor, and hydrocarbon gas and carbon dioxide are subjected to reforming reactions by the reforming reaction device, and hydrogen, carbon monoxide, and unreacted raw materials are output to the shift reaction device;

[0026] water vapor and carbon monoxide are subjected to a shift reaction by the shift reaction device, and carbon dioxide, hydrogen, and unreacted raw materials are output to the separation and purification unit;

[0027] The carbon dioxide and the hydrogen are separated by the separation and purification unit, and the carbon dioxide is output to the third supply pipeline.

[0028] Beneficial effects: the first supply pipeline, the second supply pipeline and the third supply pipeline of the embodiment of the present application input water vapor, hydrocarbon gas and carbon dioxide to the reforming reaction device respectively, so that the hydrocarbon gas and water vapor, the hydrocarbon gas and carbon dioxide are respectively reformed to produce hydrogen and carbon monoxide by the reforming reaction device, then the unreacted water vapor and the carbon monoxide produced by the reforming reaction are further converted to produce hydrogen and carbon dioxide by the shift reaction device, so as to make full use of the reaction and the remaining gas, improve the yield of hydrogen, finally separate the hydrogen and the carbon dioxide by the separation and purification unit, and output the carbon dioxide to the third supply pipeline, thereby realizing the reuse of the carbon dioxide produced in the reforming and shift reaction process, and reducing the carbon emission in the hydrogen production process. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0030] Figure 1 is a structural schematic diagram of a hydrogen production system according to an embodiment of the present application;

[0031] Figure 2 is a structural schematic diagram of a reforming reaction device according to an embodiment of the present application;

[0032] Figure 3 is a structural schematic diagram of a second heat exchange device according to an embodiment of the present application;

[0033] Figure 4 is a flow chart of a hydrogen production method according to an embodiment of the present application;

[0034] Reference: 1, gas distribution unit; 10, first supply pipeline; 100, steam generation device; 11, second supply pipeline; 110, hydrocarbon gas source; 12, third supply pipeline; 120, carbon dioxide gas source; 13, preheating mixing device; 130, mixing pipeline; 14, return pipeline; 2, reaction unit; 20, reforming reaction device; 200, heating furnace; 201, reaction furnace tube; 2010, support part; 2011, via hole; 202, reaction area; 203, gas inlet; 204, gas outlet; 21, shift reaction device; 22, first heat exchange device; 220, cooling water source; 221, drainage end; 3, separation and purification unit; 30, first pressure swing adsorption device; 31, second pressure swing adsorption device; 32, second heat exchange device; 320, outer tank body; 321, inner tank body; 322, gas inlet cavity; 3220, first liquid level meter; 3221, second liquid level meter; 323, cooling water cavity; 324, gas inlet pipe; 3240, gas inlet end; 325, gas outlet pipe; 3250, gas outlet end; 326, drainage pipe; 3260, drainage valve; 327, water inlet; 328, water outlet; 329, baffle; 4, analysis unit; 40, chromatographic analysis device; 41, first shunt branch pipe; 410, first pressure reducing valve; 42, third heat exchange device; 43, second shunt branch pipe; 430, second pressure reducing valve; 44, third shunt branch pipe; 5, proportional regulating valve; 6, temperature sensor; 7, pressure sensor; 8, flow sensor; 9, check valve; X, liquid level rising direction. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0036] In the description of the present application, it should be understood that the terms "length", "width", "thickness", "upper", "lower", "front", "back", "left", "right", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more features. In the description of the present application, the meaning of "multiple" is two or more, at least one of which can be one, two or more, unless otherwise explicitly specified.

[0037] The applicant notes that, with the continuous depletion of fossil energy and the environmental pollution problems caused by long-term use, the development and utilization of clean energy are increasingly urgent. However, there are problems such as high energy transformation cost, strong instability, and high transportation and storage cost in the utilization process of clean energy. Natural gas, as a relatively clean fossil energy, plays an important role in the energy transformation process. By using small-scale natural gas hydrogen production technology, natural gas can be converted into hydrogen, which can be used to drive hydrogen fuel cells or supply other hydrogen energy equipment, further reducing emissions and environmental pollution of traditional fuel transportation methods. On the other hand, small-scale natural gas hydrogen production can achieve distributed production, i.e. on-site production where hydrogen is needed, avoiding the problem of long-distance hydrogen transportation. This approach can reduce energy loss and cost, improve hydrogen supply efficiency, and help build more flexible and sustainable hydrogen energy infrastructure.

[0038] The main problems of the current natural gas reforming hydrogen production system are as follows: first, most natural gas hydrogen production systems are natural gas steam reforming hydrogen production, and a large amount of water vapor consumes heat;

[0039] Second, a part of carbon dioxide is produced in the hydrogen production process, and the emission of carbon dioxide causes the accumulation of greenhouse effect. Although it can be separated from the synthesis gas by separation, the storage and sequestration of carbon dioxide is still a problem, and increases the cost of the entire system;

[0040] Third, since the product may not be qualified due to the large changes in each reaction step in the system, online monitoring is very important.

[0041] Therefore, the embodiments of the present application disclose a hydrogen production system which can solve at least one of the above-mentioned defects.

[0042] Reference Figures 1 to 3A hydrogen production system includes a gas distribution unit 1, a reaction unit 2 and a separation and purification unit 3. The gas distribution unit 1 includes a first supply pipeline 10, a second supply pipeline 11 and a third supply pipeline 12. The first supply pipeline 10 is connected with a steam generation device 100 configured to supply water vapor. The second supply pipeline 11 is connected with a hydrocarbon gas source 110 configured to supply hydrocarbon gas. The third supply pipeline 12 is connected with a carbon dioxide gas source 120 configured to supply carbon dioxide.

[0043] The reaction unit 2 includes a reforming reaction device 20 and a shift reaction device 21. The first supply pipeline 10, the second supply pipeline 11 and the third supply pipeline 12 are connected to the reforming reaction device 20. The shift reaction device 21 is connected to the reforming reaction device 20. The reforming reaction device 20 is configured to enable the hydrocarbon gas and the water vapor, the hydrocarbon gas and the carbon dioxide to undergo reforming reactions respectively and output hydrogen, carbon monoxide and unreacted raw materials to the shift reaction device 21. The shift reaction device 21 is configured to enable the water vapor and the carbon monoxide to undergo a shift reaction and output hydrogen, carbon dioxide and unreacted raw materials.

[0044] The separation and purification unit 3 is connected to the shift reaction device 21. The separation and purification unit 3 is configured to at least separate the hydrogen and the carbon dioxide output by the shift reaction and at least output the hydrogen and output the carbon dioxide to the third supply pipeline 12.

[0045] The water vapor, the hydrocarbon gas and the carbon dioxide are input to the reforming reaction device 20 through the first supply pipeline 10, the second supply pipeline 11 and the third supply pipeline 12 respectively to enable the hydrocarbon gas and the water vapor, the hydrocarbon gas and the carbon dioxide to undergo reforming reactions respectively to produce hydrogen and carbon monoxide through the reforming reaction device 20. Then, the unreacted raw materials such as the water vapor and the carbon monoxide produced by the reforming reaction are further subjected to a shift reaction through the shift reaction device 21 to generate hydrogen and carbon dioxide, so as to fully utilize the generated and remaining gas and improve the yield of hydrogen. Finally, the hydrogen and the carbon dioxide are separated through the separation and purification unit 3, and the carbon dioxide is output to the third supply pipeline 12, so as to realize the reuse of the carbon dioxide generated in the reforming and shift hydrogen production process and reduce the carbon emission in the hydrogen production process.

[0046] It should be noted that the hydrocarbon gas in the embodiment is methane gas. In other embodiments, other hydrocarbon gases can also be used in the system to be subjected to joint reforming with water vapor and carbon dioxide and subjected to a shift reaction to produce hydrogen.

[0047] Specifically, in some embodiments, with reference to Figure 1, the gas distribution unit 1 further comprises a mixing pipeline 130 and a preheating mixing device 13 communicating with the mixing pipeline 130, the first supply pipeline 10, the second supply pipeline 11 and the third supply pipeline 12 communicate with the mixing pipeline 130 and communicate with the reforming reaction device 20 through the preheating mixing device 13. Among them, the first supply pipeline 10, the second supply pipeline 11 and the third supply pipeline 12 are respectively provided with proportional adjusting valves 5 between the steam generation device 100, the hydrocarbon gas source 110 and the carbon dioxide gas source 120, so as to control the input amount of each gas in real time.

[0048] In addition, the first supply pipeline 10, the second supply pipeline 11 and the third supply pipeline 12 are respectively arranged with temperature sensors 6, pressure sensors 7, flow sensors 8 and one-way valves 9 in sequence between the mixing pipeline 130, so as to monitor the temperature, pressure and flow of each output gas in real time and avoid gas backflow. The mixing pipeline 130 and the preheating mixing device 13 are also provided with temperature sensors 6 and pressure sensors 7, so as to monitor the temperature and pressure of the mixed gas in real time.

[0049] The preheating mixing device 13 can adopt an electric heating form to preheat the mixed gas, and the preheating mixing device 13 can be filled with foamed nickel to fully mix the gas and then input into the reforming reaction device 20 through the pipeline. And before inputting into the reforming reaction device 20, the pipeline is also provided with temperature sensors 6 and pressure sensors 7 to monitor the temperature and pressure.

[0050] Referring to Figure 1 and Figure 2 , the reforming reaction device 20 in the embodiment can adopt an electric heating furnace 200, which comprises a heating furnace 200 and a reaction furnace tube 201 arranged in the heating furnace 200. The bottom of the reaction furnace tube 201 is provided with an open support part 2010. The heating furnace 200 and the bottom of the reaction furnace tube 201 are provided with a gas inlet 203 for the mixed gas to enter the reaction furnace tube 201. On the one hand, the open support part 2010 is used for the gas to pass through smoothly and be distributed uniformly into the upper reaction area 202. On the other hand, the support part 2010 is also used to support the catalyst. The electric heating furnace 200 provides the heat required for the reaction. The mixed gas enters the catalyst bed from the bottom of the reaction furnace tube 201, reacts to produce hydrogen and carbon monoxide, and is discharged from the upper gas outlet 204 of the reaction tube.

[0051] The specific reforming reaction in the embodiment includes:

[0052] Methane wet reforming: CH4+H2O→3H2+CO;

[0053] Methane dry reforming: CH4+CO2→2H2+2CO;

[0054] In some embodiments, referring to Figure 1Since the temperature of the reformed gas after the reforming reaction is about 800°C, the reaction unit 2 further comprises a first heat exchange device 22 connected between the reforming reaction device 20 and the shift reaction device 21, and the gas outlet 204 is in communication with the first heat exchange device 22 through a pipeline, and the pipeline is also provided with a temperature sensor 6 and a pressure sensor 7 to monitor the temperature and pressure of the reformed gas in real time.

[0055] The first heat exchange device 22 can adopt a conventional cooling water heat exchange device, which is externally connected to a cooling water source 220 through a pipeline to exchange heat with the reformed gas passing through the first heat exchange device 22 to reduce the temperature, and a proportional regulating valve 5 is arranged on the pipeline to control the flow of cooling water to facilitate the control of the temperature of the gas after heat exchange. The first heat exchange device 22 is in communication with the shift reaction device 21 through a pipeline, and a proportional regulating valve 5, a temperature sensor 6 and a pressure sensor 7 are arranged in sequence on the pipeline to control the flow of gas, and monitor the temperature and pressure of the gas in real time.

[0056] The shift reaction device 21 is filled with a shift catalyst, and the specific shift reaction in this embodiment includes:

[0057] CO + H2O → H2 + CO2;

[0058] That is, the carbon monoxide generated by further catalytic reforming is further catalyzed with unreacted water vapor to generate more hydrogen.

[0059] In some embodiments, referring to Figure 1 and Figure 3 In this embodiment, the separation and purification unit 3 comprises a second heat exchange device 32, a first pressure swing adsorption device 30 and a second pressure swing adsorption device 31 in sequence.

[0060] The second heat exchange device 32 is connected between the shift reaction device 21 and the first pressure swing adsorption device 30, and the second heat exchange device 32 is configured to separate the water vapor in the gas output by the shift reaction device 21 and deliver other gases to the first pressure swing adsorption device 30. The first pressure swing adsorption device 30 is configured to separate the carbon dioxide in the gas output by the shift reaction device 21, and deliver the carbon dioxide to the third supply pipeline 12 and output other gases. The second pressure swing adsorption device 31 is in communication with the first pressure swing adsorption device 30 for input of other gases, and the second pressure swing adsorption device 31 is configured to separate the hydrogen in the other gases to further improve the purity of the hydrogen.

[0061] Specifically, in some embodiments, referring to Figure 1 and Figure 3The second heat exchange device 32 comprises an outer tank 320 and an inner tank 321 arranged in the outer tank 320, the inner tank 321 has a gas inlet cavity 322, the top of the inner tank 321 is connected with a gas inlet pipe 324 and a gas outlet pipe 325, and the bottom of the inner tank 321 is connected with a drain pipe 326. The gas inlet pipe 324, the gas outlet pipe 325 and the drain pipe 326 are respectively communicated with the gas inlet cavity 322, a cooling water cavity 323 is formed between the inner tank 321 and the outer tank 320, and the outer tank 320 is respectively provided with a water inlet 327 and a water outlet 328 communicated with the cooling water cavity 323, the water inlet 327 is used for inputting cooling water, and the water outlet 328 is used for discharging cooling water.

[0062] The gas inlet pipe 324 is communicated with the gas output end of the shift reaction device 21 through a pipeline, so that the gas output by the shift reaction device 21 is input into the gas inlet cavity 322, and the pipeline is also provided with the temperature sensor 6 and the pressure sensor 7. The water inlet 327 is also communicated with the cooling water source 220 through a pipeline, and the flow of the cooling water is controlled by the proportional adjusting valve 5 arranged on the pipeline. The drain pipe 326 is provided with a drain valve 3260 to control the condensed water discharged from the gas inlet cavity 322.

[0063] In some embodiments, referring to Figure 3 The inner tank 321 has a condensed water level rising direction X from bottom to top, a plurality of baffles 329 are arranged in the inner tank 321 along the level rising direction X in sequence, and adjacent baffles 329 are arranged staggered at the intersection of the level rising direction X. Meanwhile, the gas inlet pipe 324 has a gas inlet end 3240 communicated with the gas inlet cavity 322, and the gas outlet pipe 325 has a gas outlet end 3250 communicated with the gas inlet cavity 322, the gas inlet end 3240 and the gas outlet end 3250 are respectively located on the opposite sides of the plurality of baffles 329 in the level rising direction X, that is, the gas inlet end 3240 extends to the bottom of the gas inlet cavity 322, and the gas outlet end 3250 is located at the top of the inner tank 321, the plurality of baffles 329 are arranged staggered to guide the gas entering the gas inlet cavity 322 to slow down and flow, so that the gas after shift reaction is sufficiently cooled by heat exchange with the cooling water in the cooling water cavity 323, so that the gas after shift reaction is cooled to 40℃, and the high-temperature water vapor is condensed and accumulated in the gas inlet cavity 322.

[0064] Correspondingly, the first liquid level meter 3220 and the second liquid level meter 3221 are arranged in the outer tank body 320 in sequence along the liquid level rising direction X, and the first liquid level meter 3220 and the second liquid level meter 3221 extend into the air inlet cavity 322 to monitor the liquid level of the condensed water in the air inlet cavity 322 in real time. By acquiring the liquid level signals of the first liquid level meter 3220 and the second liquid level meter 3221, when the liquid level reaches the second liquid level meter 3221, the drain valve 3260 can be controlled to open to drain the condensed water, and when the liquid level reaches the first liquid level meter 3220, the drain valve 3260 can be controlled to close. The first liquid level meter 3220 ensures that a certain amount of condensed water remains in the air inlet cavity 322 to seal the air inlet end 3240 at the drain pipe 326, reducing the risk of gas leakage from the drain pipe 326.

[0065] In addition, in order to better improve the heat exchange effect of the gas in the air inlet cavity 322 and the cooling water in the cooling water cavity 323, the water inlet 327 is arranged at the bottom of the outer tank body 320, and the water outlet 328 is arranged at the top of the outer tank body 320, so that the water inlet 327 is closer to the air inlet end 3240 than the water outlet 328.

[0066] In addition, the gas outlet pipe 325 is connected to the first pressure swing adsorption device 30 through a pipeline and sequentially arranged with a flow sensor 8, a temperature sensor 6, a pressure sensor 7 and a proportional regulating valve 5 to monitor the flow, temperature and pressure of the output gas in real time and control the flow.

[0067] In the embodiment, the first pressure swing adsorption device 30 and the second pressure swing adsorption device 31 use pressure swing adsorption technology (PSA) to adsorb and separate the target gas. The first pressure swing adsorption device 30 adsorbs and separates carbon dioxide, so as to be input again to the carbon dioxide gas source 120 end for reuse, thereby reducing carbon emissions in hydrogen production and improving hydrogen production. The gas after separation of carbon dioxide is input again to the second pressure swing adsorption device 31 to adsorb and separate hydrogen, so as to extract high-purity hydrogen for use in fuel cells and the like, and the purity of the hydrogen is 99.97%, and other gases can be directly emptied or used as fuel for combustion.

[0068] In addition, in order to better monitor the gas components or purity of each reaction stage and improve the qualified rate of hydrogen production, in some embodiments, with reference to Figure 1 , the hydrogen production system further comprises an analysis unit 4, and in the embodiment, the analysis unit 4 monitors the gas components after the reforming reaction, monitors the gas after removal of water vapor by the shift reaction, and analyzes the purity of the hydrogen purified by the second pressure swing adsorption device 31.

[0069] The analysis unit 4 includes a chromatographic analysis device 40, a first shunt branch pipe 41, a first pressure reducing valve 410 arranged on the first shunt branch pipe 41, and a third heat exchange device 42. One end of the first shunt branch pipe 41 is connected to the gas output end of the reforming reaction device 20, and the other end is connected to the third heat exchange device 42. The third heat exchange device 42 is connected to the chromatographic analysis device 40. The third heat exchange device 42 is configured to reduce the temperature of the gas output by the reforming reaction device 20 and input the chromatographic analysis device 40. The chromatographic analysis device 40 is configured to analyze the components of the input gas. In addition, since the gas after the reforming reaction is a high-temperature and high-pressure gas, a first pressure reducing valve 410 needs to be arranged in the pipeline between the reforming reaction device 20 and the third heat exchange device 42 to reduce the gas pressure. The gas is reduced to room temperature by the third heat exchange device 42, and then the chromatographic analysis device 40 performs component analysis.

[0070] In addition, the analysis unit 4 further includes a second shunt branch pipe 43 and a second pressure reducing valve 430 arranged on the second shunt branch pipe 43. One end of the second shunt branch pipe 43 is connected to the other gas output end of the second heat exchange device 32, and the other end is connected to the chromatographic analysis device 40. The gas after the removal of carbon dioxide is input into the chromatographic analysis device 40 after the gas pressure is reduced by the second pressure reducing valve 430 for analysis of the gas components.

[0071] In addition, the analysis unit 4 further includes a third shunt branch pipe 44. One end of the third shunt branch pipe 44 is connected to the hydrogen output end of the second pressure swing adsorption device 31, and the other end is connected to the chromatographic analysis device 40. The purity of the purified hydrogen can be sampled and analyzed through the third shunt branch pipe 44.

[0072] The above test method for analyzing the components and purity of the gas by chromatography is a prior art and will not be described here.

[0073] In addition, with reference to Figure 1 After the cooling water required for the above heat exchange is extracted and used, it can be uniformly transported to the drainage end 221 through the pipeline for discharge.

[0074] In addition, it should be noted that the process parameters such as the ratio of the reaction raw materials can be flexibly adjusted to achieve the required amount of hydrogen in the subsequent process.

[0075] In addition, the heat energy source of the steam generator in the present embodiment can also use the heat of the reforming reaction device 20 to evaporate external water. In addition, when the steam generator produces steam by burning water, the generated carbon dioxide can also be collected, purified and input into the carbon dioxide source 120, thereby further reducing carbon emissions. The overall hydrogen production system is suitable for small-scale hydrogen production technology and is beneficial for distributed hydrogen production, i.e. hydrogen is generated on site to avoid long-distance hydrogen transportation problems, and energy loss and cost can also be reduced.

[0076] Correspondingly, the hydrogen production method of the embodiment of the present application is applied to the hydrogen production system described above, and the steps are as follows Figure 1 and Figure 4 , comprising the following steps:

[0077] hydrocarbon gas, steam and carbon dioxide are respectively input into the reforming reaction device 20 through the first supply pipeline 10, the second supply pipeline 11 and the third supply pipeline 12;

[0078] hydrocarbon gas and steam, and hydrocarbon gas and carbon dioxide are subjected to reforming reactions by the reforming reaction device 20, and hydrogen, carbon monoxide and unreacted steam are output to the shift reaction device 21;

[0079] steam and carbon monoxide are subjected to a shift reaction by the shift reaction device 21, and carbon dioxide, hydrogen and unreacted raw materials are output to the separation and purification unit 3;

[0080] carbon dioxide and hydrogen are separated by the separation and purification unit 3, and carbon dioxide is output to the third supply pipeline 12.

[0081] Specifically, the superheated steam generated by the steam generator controls the steam flow through the proportional regulating valve 5, and the steam temperature is measured by the temperature sensor 6 on the pipeline, the steam temperature is measured by the pressure sensor 7, and the steam flow is measured by the flow sensor 8; the methane flow is controlled by the proportional regulating valve 5, and the methane temperature, pressure and flow are measured by the temperature sensor 6, the pressure sensor 7 and the flow sensor 8 respectively; the carbon dioxide flow is controlled by the proportional regulating valve 5, and the carbon dioxide temperature, pressure and flow are measured by the temperature sensor 6, the pressure sensor 7 and the flow sensor 8 respectively.

[0082] The temperature and pressure of the mixed gas are measured by the temperature sensor 6 and the pressure sensor 7, the temperature of the mixed gas is ensured to be above 250℃, and the pressure is about 2.5Mpa, and then the mixed gas enters the preheating mixing device 13, where the gas is preheated and heated to 600℃ again and mixed uniformly for subsequent sufficient reaction.

[0083] After the mixed gas leaves the preheating mixing device 13, it enters the reforming reaction device 20 and reacts to produce reforming gas after passing through the catalyst bed from bottom to top. At this time, the temperature of the reforming gas is about 800℃. The reforming gas needs to pass through the first heat exchange device 22 to reduce the temperature to the required temperature for the shift reaction. In this embodiment, the temperature of the reforming gas can be reduced to 400℃, and then the gas pressure is adjusted by the proportional regulating valve 5 before entering the shift reaction device 21. After passing through the shift catalyst, the hydrogen gas is enriched.

[0084] The generated shift gas enters the second heat exchange device 32, where the temperature of the shift gas is reduced to 40℃, the water vapor is condensed and remains in the gas inlet cavity 322, and the other gas is discharged from the gas outlet pipe 325 and measured by the flow sensor 8. Subsequently, the gas passes through the first pressure swing adsorption device 30 to separate the carbon dioxide, and returns to the carbon dioxide gas source 120 as raw material, and the other gas enters the second pressure swing adsorption device 31 to separate the hydrogen.

[0085] Among them, the purity of the separated hydrogen is required to reach 99.97% for fuel cell, the product purity is detected by gas chromatography, and the other gas can be directly exhausted or used as fuel. By analyzing the gas after reforming and the gas after shifting through gas chromatography, the normal composition of the reaction gas can be ensured in real time, and the qualified rate of preparation is improved.

[0086] The above describes in detail a hydrogen production system and a hydrogen production method provided by the embodiments of the present application, and specific examples are applied to explain the principles and implementation manners of the present application. The above embodiment is only used to help understand the technical solutions and core ideas of the present application; those skilled in the art should understand that the technical solutions recorded in the above embodiments can still be modified, or some technical features can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A hydrogen production system, characterized by, The utility model relates to a kind of gas supply unit (1), the gas supply unit (1) includes first feed line (10), second feed line (11), third feed line (12), mixed line (130) and preheating mixing device (13), the first feed line (10) is connected with steam generation device (100), the first feed line (10) is configured to supply water vapor, the second feed line (11) is connected with hydrocarbon gas source (110), the second feed line (11) is configured to supply hydrocarbon gas, the third feed line (12) is connected with carbon dioxide gas source (120), the third feed line (12) is configured to supply carbon dioxide;The preheating mixing device (13) is communicated with the mixed line (130), the preheating mixing device (13) is configured to be able to heat and mix hydrocarbon gas, water vapor and carbon dioxide; Reaction unit (2), the reaction unit (2) includes reforming reaction device (20) and shift reaction device (21), the first feed line (10), the second feed line (11) and the third feed line (12) are communicated with the reforming reaction device (20), the shift reaction device (21) is communicated with the reforming reaction device (20), the reforming reaction device (20) is configured to enable hydrocarbon gas and water vapor, hydrocarbon gas and carbon dioxide respectively reforming reaction and output hydrogen, carbon monoxide and unreacted raw material to the shift reaction device (21), the shift reaction device (21) is configured to enable water vapor and carbon monoxide to occur shift reaction and output hydrogen, carbon dioxide and unreacted raw material; Separation and purification unit (3) is communicated with the shift reaction device (21), and the separation and purification unit (3) is configured to at least be able to separate hydrogen and carbon dioxide output by the shift reaction and at least output the hydrogen and output the carbon dioxide to the third feed line (12); Wherein, the first feed line (10), the second feed line (11) and the third feed line (12) are communicated with the mixed line (130), and are communicated with the reforming reaction device (20) by the preheating mixing device (13);Between the first feed line (10) and the steam generation device (100), between the second feed line (11) and the hydrocarbon gas source (110), between the third feed line (12) and the carbon dioxide gas source (120) are respectively provided with proportional regulating valve (5), to control the input quantity of each gas in real time. Temperature sensor (6), pressure sensor (7), flow sensor (8) and check valve (9) are arranged in sequence between the first feed line (10), the second feed line (11) and the third feed line (12) and the mixed line (130) respectively, to monitor the temperature, pressure, flow of each output gas in real time and avoid gas backflow.

2. The hydrogen production system of claim 1, wherein, ​ The temperature sensor (6) and the pressure sensor (7) are arranged between the mixing pipeline (130) and the preheating mixing device (13) to monitor the temperature and pressure of the mixed gas in real time; the preheating mixing device (13) is in the form of electric heating to preheat the mixed gas, and the preheating mixing device (13) can be filled with foamed nickel to fully mix the gas and then input into the reforming reaction device (20) through the pipeline; the temperature sensor (6) and the pressure sensor (7) are arranged on the pipeline before the mixed gas is input into the reforming reaction device (20) to monitor the temperature and pressure.

3. The hydrogen production system according to claim 1, wherein, The reaction unit (2) further comprises a first heat exchange device (22) connected between the reforming reaction device (20) and the shift reaction device (21) to adjust the temperature of the gas output from the reforming reaction device (20) to the shift reaction device (21).

4. The hydrogen production system according to claim 1, wherein, The separation and purification unit (3) comprises a first pressure swing adsorption device (30) connected to the shift reaction device (21), and the first pressure swing adsorption device (30) is configured to separate carbon dioxide from the gas output from the shift reaction device (21) and output other gas while delivering the carbon dioxide to the third supply pipeline (12).

5. The hydrogen production system according to claim 4, wherein, The separation and purification unit (3) further comprises a second pressure swing adsorption device (31) connected to the first pressure swing adsorption device (30) for input of the other gas, and the second pressure swing adsorption device (31) is configured to separate hydrogen from the other gas.

6. The hydrogen production system according to claim 4, wherein, The separation and purification unit (3) further comprises a second heat exchange device (32) connected between the shift reaction device (21) and the first pressure swing adsorption device (30), and the second heat exchange device (32) is configured to separate water vapor from the gas output from the shift reaction device (21) and deliver other gas to the first pressure swing adsorption device (30).

7. The hydrogen production system according to claim 6, wherein, The second heat exchange device (32) comprises an outer tank body (320) and an inner tank body (321) arranged in the outer tank body (320), the inner tank body (321) has a gas inlet cavity (322) therein, the inner tank body (321) is connected with a gas inlet pipe (324), a gas outlet pipe (325) and a drain pipe (326), the gas inlet pipe (324), the gas outlet pipe (325) and the drain pipe (326) respectively communicate with the gas inlet cavity (322), a cooling water cavity (323) is formed between the inner tank body (321) and the outer tank body (320), and the outer tank body (320) is respectively provided with a water inlet (327) and a water outlet (328) communicating with the cooling water cavity (323), the water inlet (327) is used for inputting cooling water, and the water outlet (328) is used for discharging the cooling water. The gas inlet pipe (324) communicates with the shift reaction device (21), so that the gas output by the shift reaction device (21) is input into the gas inlet cavity (322), and the drain pipe (326) is provided with a drain valve (3260) for controlling the discharge of condensed water in the gas inlet cavity (322).

8. The hydrogen production system according to claim 7, wherein A plurality of baffle plates (329) are arranged in the inner tank body (321) in sequence along a rising direction (X) of the condensed water level in the gas inlet cavity (322), and adjacent baffle plates (329) are arranged staggered in a direction intersecting the rising direction (X) of the level; The gas inlet pipe (324) has a gas inlet end (3240) communicating with the gas inlet cavity (322), and the gas outlet pipe (325) has a gas outlet end (3250) communicating with the gas inlet cavity (322); The gas inlet end (3240) and the gas outlet end (3250) are respectively located on opposite sides of a plurality of baffle plates (329) in the rising direction (X) of the level; and / or The water inlet (327) is closer to the gas inlet end (3240) than the water outlet (328).

9. The hydrogen production system according to claim 1, wherein The hydrogen production system further comprises an analysis unit (4), the analysis unit (4) comprises a chromatographic analysis device (40), a first shunt branch pipe (41), a first pressure reducing valve (410) arranged on the first shunt branch pipe (41), and a third heat exchange device (42), one end of the first shunt branch pipe (41) communicates with a gas output end of the reforming reaction device (20), the other end communicates with the third heat exchange device (42), the third heat exchange device (42) communicates with the chromatographic analysis device (40), the third heat exchange device (42) is configured to be able to reduce the temperature of the gas output by the reforming reaction device (20) and input into the chromatographic analysis device (40), and the chromatographic analysis device (40) is configured to be able to analyze the components of the input gas.

10. The hydrogen production system according to claim 6, wherein The hydrogen production system further comprises an analysis unit (4), the analysis unit (4) comprising a chromatographic analysis device (40), a second shunt branch (43) and a second pressure reducing valve (430) arranged on the second shunt branch (43), one end of the second shunt branch (43) being connected to the output end of the other gas of the second heat exchange device (32), the other end being connected to the chromatographic analysis device (40), the chromatographic analysis device (40) being configured to analyze the components of the input gas.

11. The hydrogen production system according to claim 5, wherein, The hydrogen production system further comprises an analysis unit (4), the analysis unit (4) comprising a chromatographic analysis device (40) and a third shunt branch (44), one end of the third shunt branch (44) being connected to the hydrogen output end of the second pressure swing adsorption device (31), the other end being connected to the chromatographic analysis device (40), the chromatographic analysis device (40) being configured to analyze the purity of the input hydrogen.

12. A method of producing hydrogen, characterized by, The hydrogen production system according to any one of claims 1 to 11, comprising the steps of: inputting hydrocarbon gas, steam and carbon dioxide into the reforming reaction device (20) through the first supply pipeline (10), the second supply pipeline (11) and the third supply pipeline (12) respectively; carrying out reforming reactions of hydrocarbon gas and steam, and hydrocarbon gas and carbon dioxide by the reforming reaction device (20) and outputting hydrogen, carbon monoxide and unreacted raw materials to the shift reaction device (21); carrying out a shift reaction of steam and carbon monoxide by the shift reaction device (21) and outputting carbon dioxide, hydrogen and unreacted raw materials to the separation and purification unit (3); separating carbon dioxide and hydrogen by the separation and purification unit (3) and outputting carbon dioxide to the third supply pipeline (12); controlling the steam flow rate by the proportional adjusting valve (5) between the first supply pipeline (10) and the steam generator (100); controlling the methane flow rate by the proportional adjusting valve (5) between the second supply pipeline (11) and the hydrocarbon gas source (110); controlling the carbon dioxide flow rate by the proportional adjusting valve (5) between the third supply pipeline (12) and the carbon dioxide gas source (120); mixing the gases by the gas input mixing pipeline (130) and then entering the preheating mixing device (13), and then the mixed gas enters the reforming reaction device (20) and reacts after passing through the catalyst bed from bottom to top to produce reforming gas.

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