A wind-solar-biomass gasification hydrogen production system and a method for operating the same

Abstract

The application discloses a wind-solar-biomass gasification hydrogen production system and an operation method thereof, wherein the biomass gasification hydrogen production system comprises a biomass gasification furnace, a dust removal and purification device and a multi-stage catalytic tower; the biomass gasification furnace comprises a furnace body, a gasification agent inlet, a biomass inlet and a conversion gas outlet which are arranged on the furnace body; the dust removal and purification device is communicated with the conversion gas outlet; the multi-stage catalytic tower comprises a tower body, a conversion gas inlet arranged at the top of the tower body, a hydrogen-rich gas outlet arranged at the bottom of the tower body and two or more catalytic bed layers arranged from the top of the tower body to the bottom of the tower body; the catalyst of the first-stage catalytic bed layer is a nickel-based catalyst, and the catalyst of the second-stage catalytic bed layer is a copper or iron-based catalyst. The application realizes the target of preparing high-purity hydrogen by biomass gasification, and improves the energy conversion efficiency and hydrogen production rate.

Description

Technical Field

[0001] This invention relates to the field of exhaust gas utilization technology, specifically to a wind, solar and biomass gasification hydrogen production system and its operation method. Background Technology

[0002] The search for and development of clean and renewable alternative energy sources has become an important direction for global energy development. Biomass, as a renewable energy source, has a wide range of sources, including agricultural waste, forestry waste, and municipal waste, and is characterized by a low carbon footprint and renewability. Hydrogen energy, as a green, low-carbon, and widely applicable secondary energy source, is not only efficient, clean, and renewable, but can also complement intermittent renewable energy sources such as wind and solar power, jointly promoting the diversification and stability of the energy system.

[0003] Biomass gasification hydrogen production technology converts biomass into hydrogen in a high-temperature, oxygen-deficient environment. This not only helps to fully utilize biomass resources and reduce dependence on traditional fossil fuels, but also significantly reduces greenhouse gas emissions. Furthermore, green electricity generated from wind and solar power can provide the necessary power for the biomass gasification hydrogen production process, further enhancing the overall environmental friendliness of the system.

[0004] However, current biomass gasification hydrogen production technology still faces some challenges, such as low gasification efficiency, insufficient catalytic performance, low hydrogen yield, and inadequate utilization of waste heat generated during the gasification process. Biomass gasification hydrogen production systems involve multiple stages, including feedstock pretreatment, gasification reaction, catalytic process, and hydrogen separation. Insufficient synergistic optimization between these stages makes it difficult to achieve ideal energy efficiency and hydrogen yield for the entire system. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defects of low hydrogen yield and low energy conversion efficiency in existing biomass gasification hydrogen production technology, and thus provide a wind-solar-biomass gasification hydrogen production system and its operation method to solve the above problems.

[0006] A biomass gasification hydrogen production system, comprising:

[0007] Biomass gasifier: includes the furnace body, and the gasifying agent inlet, biomass inlet, and converted gas outlet set on the furnace body;

[0008] Dust removal and purification device: connected to the outlet of the converted gas;

[0009] Multistage catalytic tower: includes a tower body that exchanges heat with the gasifying agent, a conversion gas inlet at the top of the tower body, a hydrogen-rich gas outlet at the bottom of the tower body, and two or more catalytic beds arranged from the top to the bottom of the tower body.

[0010] The catalyst of the first-stage catalytic bed is a nickel-based catalyst, and the catalyst of the second-stage catalytic bed is a copper or iron-based catalyst.

[0011] The application also comprises a catalytic synthesis tower in communication with the hydrogen-rich gas outlet.

[0012] The catalytic synthesis tower comprises a tower body in heat exchange with a gasifying agent, a hydrogen-rich gas inlet arranged at the top end of the tower body, a catalytic gas outlet arranged at the bottom end of the tower body, and a catalytic bed arranged in the tower body.

[0013] The gasifying agent is first heat-exchanged with the gas in the catalytic synthesis tower, and then heat-exchanged with the gas in the multi-stage catalytic tower, and the heat-exchanged gasifying agent enters the biomass gasification furnace through the gasifying agent inlet of the biomass gasification furnace.

[0014] The catalytic gas outlet of the catalytic synthesis tower is connected with a waste heat recovery device and a purification and purification device.

[0015] Based on the operation method of the above biomass gasification hydrogen production system, comprising:

[0016] The gasifying agent and the biomass are added to the biomass gasification furnace for gasification reaction to generate crude synthesis gas;

[0017] The crude synthesis gas is dust filtered to obtain conversion gas;

[0018] The conversion gas is input into the multi-stage catalytic tower to sequentially pass through the first-stage catalytic bed and the second-stage catalytic bed for catalytic conversion to obtain hydrogen-rich gas;

[0019] The hydrogen-rich gas is purified to obtain hydrogen gas with a purity of ≥99%.

[0020] The gasification temperature of the gasification reaction is 600-900℃, and the reaction pressure is 1.1MPa-1.6MPa.

[0021] The catalytic temperature of the first-stage catalytic bed is 700℃-810℃, and the reaction pressure is 1.2MPa-1.3MPa;

[0022] The catalytic temperature of the second-stage catalytic bed is 200-450℃, and the reaction pressure is 0.9MPa-1.1MPa.

[0023] The technical scheme of the application has the following advantages:

[0024] 1、The present application ingeniously utilizes the waste heat after gasification to carry out hydrogen production reaction by step-by-step reforming, which greatly improves the hydrogen production rate after the first and second catalytic bed layers without consuming additional heat sources to maintain the reaction temperature. This means that under the same parameter conditions, the present application can produce more hydrogen, significantly improving the hydrogen production rate and meeting the growing demand of hydrogen energy market, providing strong support for the development of hydrogen energy industry.

[0025] 2、During the operation of the biomass gasification, the start-up heating, auxiliary heating, gas compression and delivery of the gasification furnace can all use green electricity provided by wind and solar power. This not only reduces the consumption of fossil fuel and greenhouse gas emissions, but also embodies the synergistic use of renewable energy and biomass energy, promoting the optimization of energy structure and sustainable development.

[0026] 3、The present application uses raw gas heat exchange technology to make full use of the heat generated during the reaction process to preheat the raw gas entering the multi-stage catalytic tower and catalytic synthesis tower. For example, in the hydrogen production reaction of carbon monoxide and water vapor, the reaction is exothermic, and the heat generated is transferred to the raw gas through the heat exchanger to increase its temperature, thereby reducing the energy consumption required for external heating, making full use of waste heat and improving the energy utilization rate of the system.

[0027] 4、The present application improves the energy utilization rate and product purity by introducing waste heat recovery devices and purification and purification devices. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the specific embodiments of the present application or the technical solutions in the prior art, the following will briefly introduce the drawings needed to be used in the specific embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0029] Figure 1 is a structural schematic diagram of the system of embodiments 1-4 of the present application;

[0030] Figure 2 is a structural schematic diagram of the system of embodiment 5 of the present application.

[0031] Explanation of reference signs:

[0032] 1-biomass gasification furnace, 2-dust removal and purification device, 3-multistage catalytic tower, 4-first stage catalytic bed, 5-second stage catalytic bed, 6-first tower internal heat exchanger, 7-second tower internal heat exchanger, 8-purification and purification device, 9-first regulating valve, 10-second regulating valve, 11-third regulating valve, 12-fourth regulating valve, 13-waste heat recovery device, 14-catalytic synthesis tower, 15-fifth regulating valve. DETAILED DESCRIPTION

[0033] The following examples are provided to better further understand the present application, and are not limited to the best mode, and do not constitute limitations on the content and protection scope of the present application, and any person under the inspiration of the present application or the combination of the present application with other prior art features, any product identical or similar to the present application falls within the protection scope of the present application.

[0034] In the description of the present application, it should be noted that the terms "side", "upper", "lower", "top", "bottom", "vertical", "horizontal", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting 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.

[0035] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected; it can be directly connected, or indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0036] In addition, the technical features involved in the different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.

[0037] Example 1

[0038] A biomass gasification hydrogen production system, such as Figure 1As shown, including biomass gasifier 1, dust removal and purification device 2, multi-stage catalytic tower 3, waste heat recovery device 13, purification and purification device 8. Among them, the biomass gasifier 1 includes a furnace body, a gasification agent inlet, a biomass inlet and a conversion gas outlet arranged on the furnace body. The dust removal and purification device 2 has an inlet and an outlet, and the inlet is communicated with the conversion gas outlet of the biomass gasifier 1. The multi-stage catalytic tower 3 includes a tower body for heat exchange with the gasification agent, a conversion gas inlet arranged at the top of the tower body, a hydrogen-rich gas outlet arranged at the bottom of the tower body, and two or more catalytic bed layers arranged from the top of the tower body to the bottom of the tower body; wherein the catalyst of the first catalytic bed layer 4 is a nickel-based catalyst, and the catalyst of the second catalytic bed layer 5 is a copper or iron-based catalyst; the conversion gas inlet of the multi-stage catalytic tower 3 is communicated with the outlet of the dust removal and purification device 2. The hydrogen-rich gas outlet of the multi-stage catalytic tower 3 is communicated with the inlet of the waste heat recovery device 13, and the inlet of the purification and purification device 8 is communicated with the outlet of the waste heat recovery device 13.

[0039] The first-stage catalytic bed layer 4 of the multi-stage catalytic tower 3 is also provided with a first tower internal heat exchanger 6, and the second-stage catalytic bed layer 5 is also provided with a second tower internal heat exchanger 7; the gasification agent is respectively introduced into the first tower internal heat exchanger 6 and the second tower internal heat exchanger 7 through the first adjusting valve 9 and the second adjusting valve 10 respectively to exchange heat with the conversion gas input into the multi-stage catalytic tower 3, and the flow rate is controlled by the first adjusting valve 9 to control the conversion gas temperature at the first-stage catalytic bed layer 4 within the range of 200-400℃, and the flow rate is controlled by the second adjusting valve 10 to control the conversion gas temperature at the second-stage catalytic bed layer 5 within the range of 200-400℃, thereby ensuring the required temperature for catalysis of the multi-stage catalytic tower 3 while improving the temperature of the raw material gasification agent. At the same time, the flow rates of the third adjusting valve 11 and the fourth adjusting valve 12 are adjusted to control the amount and temperature of the gasification agent introduced into the biomass gasifier 1.

[0040] In this embodiment, based on the operation method of the above biomass gasification hydrogen production system, the specific process is as follows:

[0041] A fixed bed gasifier with a diameter of 2 meters and a height of 5 meters is used as the biomass gasifier 1, and is filled with pine sawdust biomass raw material. The gasifying agent is a mixture of water vapor and air, wherein the water vapor flow is 1000 m3 / h, and the air flow is 500 m3 / h. The temperature in the gasifier is controlled at 800°C, and the reaction pressure is 1.5 MPa. Under this condition, the pine sawdust biomass raw material is fully gasified, and the components of the crude synthesis gas generated are: hydrogen 35%, carbon monoxide 30%, carbon dioxide 20%, methane 10%, and other gases 5%. After the crude synthesis gas comes out of the biomass gasifier 1, the temperature is 850°C, enters the dust removal and purification device 2, so that the dust content is reduced to below 5 mg / m3, the temperature of the separated gas is reduced to 800°C, and then enters the first stage catalytic bed layer 4 of the multi-stage catalytic tower 3. Among them: the multi-stage catalytic tower 3 is 10 meters high and 2.5 meters in diameter, and is divided into two sections. The first stage catalytic bed layer 4 is filled with nickel-based catalyst, and the catalyst loading is 5 m3, and the particle diameter is 38 mm. The heat exchange area of the first tower internal heat exchanger 6 is 50 m2. The second stage catalytic bed layer 5 is filled with copper-based catalyst, and the catalyst loading is 3 m3, and the particle diameter is 3-8 mm. The heat exchange area of the second tower internal heat exchanger 7 is 40 m2.

[0042] After the crude synthesis gas enters the first stage catalytic bed layer 4, the methane and water vapor undergo a reforming reaction under the action of the nickel-based catalyst. This reaction is an endothermic reaction, and the reaction pressure is 1.2 MPa; the generated hydrogen concentration is increased to 42%. The reacted gas enters the first tower internal heat exchanger 6, which adjusts the temperature of the reacted gas to 350-400°C. After temperature adjustment, the gas enters the second stage catalytic bed layer 5, and further carbon monoxide and water vapor reforming reaction to produce hydrogen occurs under the action of the copper-based catalyst. The reaction temperature is 350-400°C, the reaction is an exothermic reaction, the reaction pressure is 1.0 MPa, and the hydrogen concentration is further increased to 55%. The second tower internal heat exchanger 7 maintains the reaction temperature at 350-400°C, and the reacted gas enters the waste heat recovery device 13 and the purification and purification device 8. The final obtained hydrogen purity can reach more than 99%.

[0043] During the operation of the biomass gasification process, the start-up heating, auxiliary heating of the gasifier, and gas compression and transportation all use green electricity provided by wind and solar power.

[0044] Example 2

[0045] The difference between this example and Example 1 is that the parameter conditions of the operation method are different, and the specific process is as follows:

[0046] A fluidized bed gasifier with a diameter of 1.8 meters and a height of 4.5 meters is selected as the biomass gasifier 1, which is filled with rice hull biomass raw materials, and the gasifying agent is a mixture of water vapor and oxygen, with a water vapor flow rate of 900 m³ / h and an oxygen flow rate of 350 m³ / h. The temperature in the gasifier is controlled at 700°C, and the reaction pressure is 1.1 MPa. Under these conditions, the rice hull biomass raw materials are fully gasified, and the components of the crude synthesis gas generated are: hydrogen 33%, carbon monoxide 32%, carbon dioxide 20%, methane 10%, and other gases 5%. After the crude synthesis gas comes out of the gasifier, the temperature is 740°C, enters the dust removal and purification device 2, and the dust content is reduced to below 5 mg / m³, and the temperature of the separated gas is reduced to 700°C, and then enters the first stage of the multi-stage catalytic tower 3. The multi-stage catalytic tower 3 is 9 meters high and 2.2 meters in diameter, and is divided into two sections. The first stage of the catalytic bed layer 4 is filled with nickel-based catalyst, and the catalyst loading is 4.5 m³, with a particle diameter of 5 mm. The heat exchange area of the first tower internal heat exchanger 6 is 45 m². The second stage of the catalytic bed layer 5 is filled with copper-based catalyst, and the catalyst loading is 3 m³, with a particle diameter of 4 mm. The heat exchange area of the second tower internal heat exchanger 7 is 35 m².

[0047] The crude synthesis gas enters the first stage of the catalytic bed layer 4, and under the action of the nickel-based catalyst, the methane and water vapor undergo a reforming reaction, which is an endothermic reaction, and the reaction pressure is 1.2 MPa. The generated hydrogen concentration is increased to 36%. The reacted gas enters the first tower internal heat exchanger 6, which adjusts the temperature of the reacted gas to 200-400°C. After temperature adjustment, the gas enters the second stage of the catalytic bed layer 5, and under the action of the copper-based catalyst, further hydrogen production reaction of carbon monoxide and water vapor reforming occurs, the reaction temperature is 200-400°C, the reaction is an exothermic reaction, the reaction pressure is 0.9 MPa, and the hydrogen concentration is further increased to 48%. The reacted gas enters the waste heat recovery device 13 and the purification and purification device 8, and the final obtained hydrogen purity can reach more than 99%.

[0048] During the operation of the biomass gasification process, the start-up heating, auxiliary heating of the gasifier, and gas compression and transportation all use green electricity provided by wind and solar power, achieving green energy driving of the entire system.

[0049] Example 3

[0050] The difference between this example and Example 1 is that the parameter conditions of the operation method are different, and the specific process is as follows:

[0051] A circulating fluidized bed gasifier with a diameter of 2.2 meters and a height of 5.5 meters is used as the biomass gasifier 1, and wheat straw biomass raw materials are filled therein. The gasifying agent is a mixture of water vapor and air, the water vapor flow is 1200 m3 / h, and the air flow is 400 m3 / h. The temperature in the gasifier is controlled at 820°C, and the reaction pressure is 1.6 MPa. Under this condition, the wheat straw biomass raw material is fully gasified, and the components of the crude synthesis gas generated are: hydrogen 32%, carbon monoxide 33%, carbon dioxide 23%, methane 10%, and other gases 12%. After the crude synthesis gas comes out of the gasifier, the temperature is 870°C, enters the dust removal and purification device 2, so that the dust content is reduced to below 5 mg / m3, the temperature of the separated gas is reduced to 780°C, and then enters the first stage of the multi-stage catalytic tower 3. The multi-stage catalytic tower 3 is 11 meters high and 2.8 meters in diameter, and is divided into two sections. The first stage of the catalytic bed layer 4 is filled with a nickel-based catalyst, and the catalyst loading is 6 m3, and the particle diameter is 7 mm. The heat exchange area of the first tower heat exchanger 6 is 60 m2. The second stage of the catalytic bed layer 5 is filled with an iron-based catalyst, and the catalyst loading is 4 m3, and the particle diameter is 6 mm. The heat exchange area of the second tower heat exchanger 7 is 50 m2.

[0052] The crude synthesis gas enters the first stage of the catalytic bed layer 4, and under the action of the nickel-based catalyst, the methane and water vapor undergo a reforming reaction. This reaction is an endothermic reaction, and the reaction pressure is 1.3 MPa. The generated hydrogen concentration is increased to 40%. The reacted gas enters the first tower heat exchanger 6, and the first tower heat exchanger 6 adjusts the temperature of the reacted gas to 350-400°C. After temperature adjustment, the gas enters the second stage of the catalytic bed layer 5, and under the action of the iron-based catalyst, further carbon monoxide and water vapor reforming reaction to produce hydrogen occurs. The reaction temperature is 350-400°C, and the reaction is an exothermic reaction, and the reaction pressure is 1.1 MPa. The hydrogen concentration is further increased to 49%. The reacted gas enters the waste heat recovery device 13 and the purification and purification device 8, and the final obtained hydrogen purity can reach more than 99%.

[0053] During the operation of the biomass gasification process, the start-up heating, auxiliary heating of the gasifier, and gas compression and transportation all use green electricity provided by wind and solar power, achieving green energy driving of the entire system.

[0054] Example 4

[0055] The difference between this embodiment and example 1 is that the parameter conditions of the operation method are different, and the specific process is as follows:

[0056] A fixed bed gasifier with a diameter of 2.5 meters and a height of 6 meters is used as the biomass gasifier 1, and is filled with cotton stalk biomass raw materials. The gasifying agent is a mixture of water vapor and air, with a water vapor flow rate of 1100 m³ / h and an air flow rate of 450 m³ / h. The temperature in the gasifier is controlled at 820°C, and the reaction pressure is 1.4 MPa. Under these conditions, the cotton stalk biomass raw materials are fully gasified, and the components of the crude synthesis gas generated are: hydrogen 34%, carbon monoxide 31%, carbon dioxide 22%, methane 11%, and other gases 12%. After the crude synthesis gas exits the gasifier, the temperature is 860°C, and it enters the dust removal and purification device 2, which reduces the dust content to below 5 mg / m³, and the temperature of the separated gas is reduced to 810°C. Then it enters the first stage of the multi-stage catalytic tower 3, the first catalytic bed layer 4. The multi-stage catalytic tower 3 is 10.5 meters high and 2.7 meters in diameter, and is divided into two sections. The first catalytic bed layer 4 is filled with nickel-based catalyst, and the catalyst loading is 5.5 m³, with a particle diameter of 4-7 mm. The first tower internal heat exchanger 6 has a heat exchange area of 55 m². The second catalytic bed layer 5 is filled with copper-based catalyst, and the catalyst loading is 3.5 m³, with a particle diameter of 3-6 mm. The second tower internal heat exchanger 7 has a heat exchange area of 45 m².

[0057] The crude synthesis gas enters the first catalytic bed layer 4, where it undergoes a reforming reaction with water vapor in the presence of nickel-based catalyst. This reaction is an endothermic reaction, and the reaction pressure is 1.25 MPa. The hydrogen concentration is increased to 44%. The first tower internal heat exchanger 6 adjusts the temperature of the reacted gas to 300-400°C. After temperature adjustment, the gas enters the second catalytic bed layer 5, where it undergoes a carbon monoxide and water vapor reforming reaction to produce hydrogen in the presence of copper-based catalyst. The reaction temperature is 300-400°C, and this reaction is an exothermic reaction, with a reaction pressure of 1.05 MPa. The hydrogen concentration is further increased to 54%, and the second tower internal heat exchanger 7 maintains the reaction temperature at 300-400°C. The reacted gas enters the waste heat recovery device 13 and the purification and purification device 8, and the final hydrogen purity can reach more than 99%.

[0058] During the operation of the biomass gasification system, the startup heating, auxiliary heating of the gasifier, and gas compression and transportation are all powered by green electricity from wind and solar power, achieving green energy driving of the entire system.

[0059] Example 5

[0060] A biomass gasification hydrogen production system, as shown in Figure 2As shown, it comprises a biomass gasifier 1, a dust removal and purification device 2, a multi-stage catalytic tower 3, a catalytic synthesis tower 14, a waste heat recovery device 13, and a purification and purification device 8. The biomass gasifier 1 comprises a furnace body, a gasification agent inlet, a biomass inlet, and a conversion gas outlet arranged on the furnace body. The dust removal and purification device 2 has an inlet and an outlet, and the inlet is communicated with the conversion gas outlet of the biomass gasifier 1. The multi-stage catalytic tower 3 comprises a tower body for heat exchange with the gasification agent, a conversion gas inlet arranged at the top end of the tower body, a hydrogen-rich gas outlet arranged at the bottom end of the tower body, and two or more catalytic bed layers arranged along the top end to the bottom end of the tower body; wherein the catalyst of the first catalytic bed layer 4 is a nickel-based catalyst, and the catalyst of the second catalytic bed layer 5 is a copper or iron-based catalyst; the conversion gas inlet of the multi-stage catalytic tower 3 is communicated with the outlet of the dust removal and purification device 2. The catalytic synthesis tower 14 comprises a tower body, a hydrogen-rich gas inlet arranged at the top end of the tower body, a catalytic gas outlet arranged at the bottom end of the tower body, and a catalytic bed layer arranged in the tower body; the catalyst of the catalytic bed layer in the catalytic synthesis tower 14 is a copper-based catalyst; the hydrogen-rich gas inlet of the catalytic synthesis tower 14 is communicated with the hydrogen-rich gas outlet of the multi-stage catalytic tower 3, the catalytic gas outlet of the catalytic synthesis tower 14 is communicated with the inlet of the waste heat recovery device 13, and the inlet of the purification and purification device 8 is communicated with the outlet of the waste heat recovery device 13.

[0061] The third tower internal heat exchanger is arranged at the position of the catalytic bed layer of the catalytic synthesis tower 14, the first tower internal heat exchanger 6 is arranged at the position of the first catalytic bed layer 4 of the multi-stage catalytic tower 3, and the second tower internal heat exchanger 7 is arranged at the position of the second catalytic bed layer 5. The gasification agent first passes through the fifth adjusting valve 15 to adjust the flow rate, and then enters the third tower internal heat exchanger of the catalytic synthesis tower 14 to exchange heat with the hydrogen-rich gas of the multi-stage catalytic tower 3. The gasification agent after heat exchange is mixed with another source of gasification agent, and respectively passes through the first adjusting valve 9 and the second adjusting valve 10 to enter the first tower internal heat exchanger 6 and the second tower internal heat exchanger 7, respectively, to exchange heat with the conversion gas input into the multi-stage catalytic tower 3. The flow rate is controlled by the first adjusting valve 9 to control the conversion gas temperature at the position of the first catalytic bed layer 4 within the range of 200-400℃, and the flow rate is controlled by the second adjusting valve 10 to control the conversion gas temperature at the position of the second catalytic bed layer 5 within the range of 200-400℃, thereby ensuring the required temperature for catalysis of the multi-stage catalytic tower 3 while improving the temperature of the raw material gasification agent. At the same time, the flow rates of the third adjusting valve 11 and the fourth adjusting valve 12 are adjusted to control the amount and temperature of the gasification agent input into the biomass gasifier 1.

[0062] The biomass raw material is fed into the biomass gasifier 1 and the gasification agent (a mixture of water vapor and oxygen / air) is fed in, and the gasification reaction occurs in the gasifier to generate the crude synthesis gas. The crude synthesis gas is purified by the dust removal device 2 to separate the dust particles therein, and the clean synthesis gas is obtained. The clean synthesis gas enters the first stage of the multi-stage catalytic tower 3, and the reforming reaction of methane and water vapor occurs in the first catalytic bed 4 under the action of the nickel-based catalyst to generate hydrogen and carbon monoxide, and the gas temperature is adjusted by the first tower heat exchanger. The adjusted gas enters the second stage of the multi-stage catalytic tower 3, and the further reforming reaction of carbon monoxide and water vapor occurs in the second catalytic bed 5 under the action of the copper or iron-based catalyst to generate more hydrogen-rich gas, and the reaction temperature is adjusted by the second tower heat exchanger. The hydrogen-rich gas is obtained after the hydrogen-rich gas is discharged from the multi-stage catalytic tower 3, and is purified by the purification device 8, and finally the high-purity hydrogen product is obtained. The first adjusting valve 9, the second adjusting valve 10, the third adjusting valve 11 and the fourth adjusting valve 12 are used to adjust the inlet and outlet flow of the gasification agent (a mixture of water vapor and oxygen / air). For the gas that is not completely reacted in the multi-stage catalytic tower 3, the nth catalytic synthesis tower, such as the catalytic synthesis tower 14 in this embodiment, can be further added to further improve the hydrogen yield.

[0063] The operation method of the biomass gasification hydrogen production system in this embodiment is as follows:

[0064] A fixed bed gasifier with a diameter of 2 meters and a height of 5 meters is used as the biomass gasifier 1, and pine sawdust biomass raw material is filled therein, and the gasification agent is a mixture of water vapor and air, wherein the water vapor flow is 1000 m³ / h and the air flow is 500 m³ / h. The temperature in the gasifier is controlled at 800°C, and the reaction pressure is 1.5 MPa. Under this condition, the pine sawdust biomass raw material is fully gasified, and the components of the crude synthesis gas generated are: hydrogen 35%, carbon monoxide 30%, carbon dioxide 20%, methane 10%, and other gases 5%. After the crude synthesis gas is discharged from the biomass gasifier 1, the temperature is 850°C, and the dust content is reduced to below 5 mg / m³ after entering the dust removal purification device 2, and the temperature of the separated gas is reduced to 800°C, and then enters the first catalytic bed 4 of the multi-stage catalytic tower 3. The multi-stage catalytic tower 3 is 10 meters high and 2.5 meters in diameter, and is divided into two stages. The first catalytic bed 4 is filled with nickel-based catalyst, and the catalyst loading is 5 m³, and the particle diameter is 38 mm. The heat exchange area of the first tower heat exchanger 6 is 50 m². The second catalytic bed 5 is filled with copper-based catalyst, and the catalyst loading is 3 m³, and the particle diameter is 3-8 mm. The heat exchange area of the second tower heat exchanger 7 is 40 m².

[0065] The crude synthesis gas enters the first stage catalytic bed 4, and under the action of the nickel-based catalyst, the methane and water vapor undergo a reforming reaction. The reaction is an endothermic reaction, and the reaction pressure is 1.2 MPa; the generated hydrogen concentration is increased to 42%. The reacted gas enters the first tower internal heat exchanger 6, and the first tower internal heat exchanger 6 adjusts the temperature of the reacted gas to 350-400℃. The gas after temperature adjustment enters the second stage catalytic bed 5, and under the action of the copper-based catalyst, further carbon monoxide and water vapor reforming reaction to produce hydrogen occurs. The reaction temperature is 350-400℃, the reaction is an exothermic reaction, the reaction pressure is 1.0 MPa, and the hydrogen concentration is further increased to 55%; the second tower internal heat exchanger 7 maintains the reaction temperature at 350-400℃.

[0066] The hydrogen-rich gas discharged from the second tower internal heat exchanger 7 of the multi-stage catalytic tower 3 is input into the catalytic synthesis tower 14. A fixed bed gasifier with a diameter of 2.5 meters and a height of 5 meters is used as the catalytic synthesis tower 14. The catalytic bed in the catalytic synthesis tower 14 is filled with copper catalyst, and the catalyst loading is 3m³, and the particle diameter is 3-8mm. The heat exchange area of the third tower internal heat exchanger arranged at the position of the catalytic bed of the catalytic synthesis tower 14 is 40m². The hydrogen-rich gas enters the catalytic synthesis tower 14, and under the action of the copper-based catalyst, further carbon monoxide and water vapor reforming reaction to produce hydrogen occurs. The reaction temperature is 350-400℃, the reaction is an exothermic reaction, the reaction pressure is 1.0 MPa, and the hydrogen concentration is further increased to 60%; the reacted gas enters the waste heat recovery device 13 and the purification and purification device 8, and the final obtained hydrogen purity can reach more than 99%.

[0067] During the operation of the biomass gasification, the start-up heating, auxiliary heating of the gasifier, and gas compression and transportation all use green electricity provided by wind and solar power.

[0068] Obviously, the above embodiments are only examples for clearly illustrating, and are not intended to limit the implementation modes. Based on the above description, other different forms of changes or variations can also be made by those skilled in the art. Here, all the implementation modes are not required or can not be exhausted. The obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A method for operating a biomass gasification hydrogen production system, characterized in that, The biomass gasification hydrogen production system comprises: A biomass gasification furnace, comprising a furnace body, a gasifying agent inlet, a biomass inlet and a conversion gas outlet arranged on the furnace body; A dust removal and purification device in communication with the conversion gas outlet; A multi-stage catalytic tower, comprising a tower body, a conversion gas inlet arranged at the top of the tower body, a hydrogen-rich gas outlet arranged at the bottom of the tower body, and two or more catalytic bed layers arranged along the tower body from the top to the bottom; The catalyst of the first catalytic bed layer is a nickel-based catalyst, and the catalyst of the second catalytic bed layer is a copper or iron-based catalyst; The first-stage catalytic bed layer position of the multi-stage catalytic tower is further provided with a first tower internal heat exchanger, and the second-stage catalytic bed layer position is further provided with a second tower internal heat exchanger; The operation method comprises: The gasifying agent and the biomass are added into the biomass gasification furnace for gasification reaction to generate crude synthesis gas; The crude synthesis gas is subjected to dust removal and filtration to obtain conversion gas; The conversion gas is input into the multi-stage catalytic tower to sequentially pass through the first-stage catalytic bed layer and the second-stage catalytic bed layer for catalytic conversion to obtain hydrogen-rich gas; The hydrogen-rich gas is subjected to purification and purification to obtain hydrogen with a purity of ≥99%; The gasifying agent is first subjected to heat exchange with the conversion gas input into the multi-stage catalytic tower through the first regulating valve and the second regulating valve to control the flow rate of the first regulating valve to control the conversion gas temperature at the first-stage catalytic bed layer position within the range of 200-400 DEG C, and control the flow rate of the second regulating valve to control the conversion gas temperature at the second-stage catalytic bed layer position within the range of 200-400 DEG C.

2. The method of operating of claim 1, wherein, Further comprising a catalytic synthesis tower in communication with the hydrogen-rich gas outlet.

3. The method of operation of claim 2, wherein, The catalytic synthesis tower comprises a tower body, a hydrogen-rich gas inlet arranged at the top of the tower body, a catalytic gas outlet arranged at the bottom of the tower body, and a catalytic bed layer arranged in the tower body.

4. The method of operating of claim 3, wherein, The gasifying agent is first subjected to heat exchange with the tower internal gas of the catalytic synthesis tower, and then subjected to heat exchange with the tower internal gas of the multi-stage catalytic tower, and the heat-exchanged gasifying agent enters the biomass gasification furnace through the gasifying agent inlet of the biomass gasification furnace.

5. The method of operating according to any of claims 2-4, characterized in that, The catalytic gas outlet of the catalytic synthesis tower is connected with a waste heat recovery device and a purification and purification device.

6. The method of operating of claim 1, wherein, The gasification temperature of the gasification reaction is 600-900 DEG C, and the reaction pressure is 1.1-1.6 MPa.

7. The method of operating of claim 1, wherein, The catalytic temperature of the first-stage catalytic bed layer is 700-810 DEG C, and the reaction pressure is 1.2-1.3 MPa.

8. The method of operating of claim 1, wherein, The catalytic temperature of the second-stage catalytic bed layer is 200-450 DEG C, and the reaction pressure is 0.9-1.1 MPa.

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