System and method for producing green hydrogen by coupling catalytic pyrolysis of biomass with volatile chemical looping reforming

Abstract

The present application relates to the field of biomass high-value conversion, and particularly relates to a biomass catalytic pyrolysis coupling volatile chemical chain reforming green hydrogen system and method, which comprises a catalytic pyrolysis reaction unit, a reduction reaction unit, an oxidation reaction unit and a hydrogen gas purification unit, the reduced oxygen carrier is sent into the catalytic pyrolysis reaction unit, and the catalytic pyrolysis of biomass is catalyzed by using the catalytic effect of the reduced oxygen carrier, which can not only promote the in-situ precipitation of biological hydrogen, realize the catalytic upgrading of volatile macromolecules, and improve the content of light components, but also provide more easily converted hydrogen production raw materials for the reduction reaction in the subsequent reduction reaction unit. Moreover, the biological oxygen in the volatile macromolecule is in-situ migrated to the oxygen carrier lattice during the catalytic upgrading process, realizing the primary recovery of the oxygen carrier lattice oxygen, converting the low-value biological oxygen into controllable released lattice oxygen, thereby reducing the reaction temperature and realizing the efficient production of green hydrogen, and solving the problems of low conversion rate and high oxygen content in the volatile in the existing biomass chemical chain gasification technology.

Description

Technical Field

[0001] This invention relates to the field of biomass high-value conversion, specifically a biomass catalytic pyrolysis coupled with volatile matter chemical chain reforming system for producing green hydrogen. Background Technology

[0002] Hydrogen energy, especially green hydrogen produced from renewable energy sources, is considered a key energy carrier in the future clean energy system due to its outstanding environmental characteristics: its combustion product is only water, and its carbon emissions throughout its entire life cycle are almost zero. Among the many green hydrogen production pathways, biomass energy has attracted much attention due to its unique dual attributes of "green carbon" and "green hydrogen." Biomass can produce hydrogen-rich syngas or high-purity hydrogen through thermochemical or biochemical conversion pathways, thereby converting low-grade solid biomass resources into high-grade clean hydrogen energy. In the field of biomass thermochemical conversion for hydrogen production, biomass gasification technology is currently the mainstream method. Its basic principle is to partially oxidize biomass feedstock under high-temperature conditions with the help of a gasifying agent, converting solid biomass into syngas with carbon monoxide, hydrogen, carbon dioxide, and methane as its main components. However, in conventional gasification processes, multiple reactions such as pyrolysis, oxidation, and reduction occur simultaneously in the same reactor. The complex and coupled reaction pathways make it difficult to precisely control product selectivity, resulting in typically high tar content in the syngas. Subsequent tar removal not only increases process and operating costs but also easily leads to clogging of downstream equipment and catalyst deactivation. Furthermore, the low heat transfer efficiency and uneven temperature distribution within the reactor in conventional gasification processes further limit the improvement of carbon conversion efficiency and hydrogen yield.

[0003] Chinese invention patent CN114350411B discloses a method and system for preparing hydrogen-rich syngas from carbon-based solid fuels through chemical looping reforming. This method decomposes the conventional gasification process into two independent stages: pyrolysis and chemical looping reforming, significantly improving reaction efficiency and product selectivity. This strategy, through spatial or temporal process separation, not only effectively inhibits secondary polymerization of tar but also optimizes heat transfer and material balance within the reactor. By precisely controlling the pyrolysis temperature, oxygen carrier composition, and reforming reaction conditions, in-situ catalytic conversion of biomass tar and highly selective production of green hydrogen can be achieved, providing a new approach for the efficient utilization of biomass. However, although the method of decomposing the conventional gasification process into two independent stages—pyrolysis and chemical looping reforming—can improve biomass conversion efficiency, in the pyrolysis reaction stage, even with optimized pyrolysis conditions, a considerable proportion (nearly 10%) of hydrogen is still fixed in the final pyrolysis coke solids, failing to be effectively released into the volatile phase to participate in subsequent reforming reactions, resulting in a loss of system hydrogen conversion efficiency. Therefore, further activating and extracting the residual hydrogen from the pyrolysis coke to participate in the main reaction pathway for hydrogen generation has become a key breakthrough in improving the overall hydrogen yield and resource utilization efficiency of the entire process. Meanwhile, biomass pyrolysis volatiles exhibit diversity in type and content, generally classified into small volatile molecules (mainly CO, CO2, CH4, and H2) and large volatile molecules (ketones, aldehydes, phenols, alcohols, acids, etc.). These large volatile molecules often have high oxygen content. After entering the chemical reforming reactor, these high-oxygen-content volatiles undergo a series of parallel or continuous competitive reactions with the oxygen carrier. On the one hand, this consumes hydrogen atoms, reducing the hydrogen selectivity in the final syngas; on the other hand, it alters the local redox atmosphere inside the reactor, affecting the oxidation state distribution and reactivity of the oxygen carrier. Therefore, effectively pre-improving the quality of large-molecule volatiles during the pyrolysis stage to suppress unnecessary oxygen release during subsequent reforming processes has become another challenge restricting the improvement of hydrogen yield and quality. Summary of the Invention

[0004] To address the problems of low conversion rate and high oxygen content in volatiles in existing biomass chemical chain gasification technology, this invention provides a biomass catalytic pyrolysis coupled with volatile chemical chain reforming system and method for producing green hydrogen.

[0005] To achieve the above objectives, the present invention employs the following technical solution: This invention provides a biomass catalytic pyrolysis coupled with volatile matter chemical chain reforming system for producing green hydrogen, comprising a catalytic pyrolysis reaction unit, a reduction reaction unit, an oxidation reaction unit, and a hydrogen purification unit; The catalytic pyrolysis reaction unit is used to catalytically pyrolyze biomass to produce pyrolysis gaseous products and pyrolysis solid products. The pyrolysis gaseous products are introduced into the reduction reaction unit, and the pyrolysis solid products are introduced into the oxidation reaction unit. The pyrolysis gaseous products include volatile macromolecules and volatile small molecules. The pyrolysis solid products include pyrolysis coke and a heat carrier oxygen carrier that initially restores lattice oxygen. The oxidation reaction unit is used to oxidize the heat carrier oxygen that has initially restored lattice oxygen and to burn pyrolysis coke to obtain a heat carrier oxygen that has fully replenished lattice oxygen and oxygen-deficient flue gas. The heat carrier oxygen that has fully replenished lattice oxygen is introduced into the reduction reaction unit, and the oxygen-deficient flue gas is output and collected. The reduction reaction unit is used to reform the pyrolysis gaseous products with a heat carrier oxygen carrier that has been fully replenished with lattice oxygen to obtain hydrogen-rich syngas and a heat carrier oxygen carrier that has lost lattice oxygen. The hydrogen-rich syngas is then introduced into the hydrogen purification unit, and the heat carrier oxygen carrier that has lost lattice oxygen is introduced into the catalytic pyrolysis reaction unit to participate in the next cycle. The hydrogen purification unit is used to purify hydrogen-rich syngas to obtain green hydrogen.

[0006] Optionally, the catalytic pyrolysis reaction unit includes a pyrolysis reactor, a first gas-solid separator, and a first return valve; the pyrolysis reactor has an internal oxygen carrier, and the product outlet of the pyrolysis reactor is connected to the first gas-solid separator, the solid phase outlet of the first gas-solid separator is sequentially connected to the first return valve and the oxidation reaction unit, and the gas phase outlet of the first gas-solid separator is connected to the reduction reaction unit.

[0007] Optionally, the catalytic pyrolysis reaction unit further includes a first booster fan and a heat exchanger, with the outlet of the first booster fan connected in sequence to the heat exchanger and the pyrolysis reactor.

[0008] Optionally, the oxidation reaction unit includes an oxidation reactor, a second gas-solid separator, and a second return valve. The input end of the oxidation reactor is connected to the first return valve. The output end of the oxidation reactor is connected to the second gas-solid separator. The solid phase output end of the second gas-solid separator is sequentially connected to the second return valve and the reduction reaction unit. The gas phase output end of the second gas-solid separator is connected to a heat exchanger.

[0009] Optionally, the oxidation reaction unit further includes a second booster fan, the output of which is connected to the oxidation reactor.

[0010] Optionally, the reduction reaction unit includes a reduction reactor, a third gas-solid separator, and a third return valve. The solid phase input end of the reduction reactor is connected to the second return valve, and the gas phase input end of the reduction reactor is connected to the gas phase outlet of the first gas-solid separator. The output end of the reduction reactor is connected to the third gas-solid separator, and the solid phase output end of the third gas-solid separator is sequentially connected to the third return valve and the pyrolysis reactor. The gas phase output end of the third gas-solid separator is connected to the hydrogen purification unit.

[0011] Optionally, the reduction reaction unit further includes a steam pump, the output of which is connected in sequence to a heat exchanger and a reduction reactor.

[0012] Optionally, the hydrogen purification unit includes a water-vapor shift device, an acid gas removal device, and a pressure swing adsorption device. The input end of the water-vapor shift device is connected to the output end of the steam pump and the gas phase output end of the third gas-solid separator. The output end of the water-vapor shift device is connected in sequence to the acid gas removal device and the pressure swing adsorption device.

[0013] Optionally, valves are provided at the outlets of the first booster fan, the steam pump, and the second booster fan.

[0014] This invention also provides a method for producing green hydrogen through biomass catalytic pyrolysis coupled with volatile matter chain reforming, comprising: Biomass is introduced into a catalytic pyrolysis reaction unit, where it undergoes catalytic pyrolysis under the action of an inert fluidizing medium and a heat-carrying oxygen carrier to produce pyrolysis gaseous products and pyrolysis solid products. The pyrolysis gaseous products include volatile macromolecules and volatile small molecules; the pyrolysis solid products include pyrolysis coke and a heat-carrying oxygen carrier that initially restores lattice oxygen. The pyrolysis solid products are introduced into the oxidation reaction unit, so that the heat carrier oxygen that initially restores lattice oxygen reacts with the oxidant to obtain a heat carrier oxygen that fully replenishes lattice oxygen, and the pyrolysis coke is burned in the oxidation reaction unit to produce oxygen-deficient flue gas. A heat-carrying oxygen carrier with fully replenished lattice oxygen is introduced into the reduction reaction unit, and the pyrolysis gaseous products are introduced into the reduction reaction unit to undergo a reforming reaction with the heat-carrying oxygen carrier with fully replenished lattice oxygen, to obtain hydrogen-rich syngas and a heat-carrying oxygen carrier that has lost lattice oxygen. The heat-carrying oxygen carrier that has lost its lattice oxygen is introduced into the catalytic pyrolysis reaction unit to catalyze the pyrolysis of biomass and participate in the next cycle; Hydrogen-rich syngas is introduced into a hydrogen purification unit for hydrogen purification to obtain green hydrogen.

[0015] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a biomass catalytic pyrolysis coupled with volatile matter chemical chain reforming to produce green hydrogen. This system organically integrates a catalytic pyrolysis reaction unit, a reduction reaction unit, an oxidation reaction unit, and a hydrogen purification unit, constructing a closed-loop system with circulating heat-carrying oxygen carriers, spatial decoupling of the reaction process, and tiered energy utilization. This enables the production of green hydrogen from biomass through catalytic pyrolysis coupled with volatile matter chemical chain reforming. Through a three-circulating fluidized bed consisting of a catalytic pyrolysis reaction unit, a reduction reaction unit, and an oxidation reaction unit, a reduced oxygen carrier (a heat-carrying oxygen carrier that has lost its lattice oxygen) is fed into the catalytic pyrolysis reaction unit. The catalytic action of the reduced oxygen carrier catalyzes the pyrolysis of biomass, lowering the energy barrier of the cracking reaction and promoting hydrogen transfer, making it easier for biomass macromolecules to break down into smaller volatile molecules, while stabilizing hydrogen in the gaseous products. Simultaneously, the synergistic effect of acidic and metallic sites in the oxygen carrier causes the large tar molecules in the volatiles to undergo cracking and deoxygenation reactions (decarbonylation and decarboxylation), generating light hydrocarbons, thereby achieving in-situ deoxygenation and quality improvement. Therefore, catalytic pyrolysis can provide more readily convertible feedstock for hydrogen production in subsequent reduction reaction units. Furthermore, bio-oxygen in the volatile macromolecules migrates in situ to the oxygen carrier lattice during catalytic upgrading, achieving primary recovery of oxygen in the oxygen carrier lattice and converting low-value bio-oxygen into controllably released lattice oxygen, thereby reducing the reaction temperature and achieving efficient green hydrogen production. Simultaneously, the catalytic pyrolysis and chemical reforming reactions occurring in the catalytic pyrolysis and reduction reaction units are endothermic reactions, while the pyrolysis-coke combustion reaction and oxygen carrier oxidation reaction occurring in the oxidation reaction unit are exothermic reactions. The hydrogen purification process in the hydrogen purification unit is endothermic. The entire system, through heat exchangers and booster fans, allows the heat generated in the oxidation reaction unit to be transferred to other reaction units for participation in corresponding reactions. Simultaneously, the circulating flow of the oxygen carrier carries away heat, achieving heat self-sufficiency and recycling of flue gas waste heat, further improving the system's energy economy.

[0016] This invention also provides a method for producing green hydrogen through biomass catalytic pyrolysis coupled with volatile matter chemical chain reforming. This method introduces a heat-carrying oxygen carrier as the catalytic pyrolysis medium during the pyrolysis stage, instead of solely using an inert fluidizing medium. When the heat-carrying oxygen carrier returns from the reduction reaction unit to the catalytic pyrolysis reaction unit, it is in a reduced state (i.e., without lattice oxygen). In this state, the oxygen carrier surface has a large number of oxygen vacancies and low-valence metal ions, exhibiting excellent catalytic cracking and hydrodeoxygenation activity. When the biomass feedstock is heated in the catalytic pyrolysis reaction unit, preliminary cracking occurs first, generating primary volatiles. These primary volatiles then come into full contact with the reduced-state heat-carrying oxygen carrier. The active sites on the oxygen carrier surface can selectively break the carbon-oxygen bonds of oxygen-containing functional groups in macromolecules, promoting the deoxygenation reaction. However, unlike conventional oxidation conditions, the oxygen vacancies provided by the reduced-state oxygen carrier tend to gently remove oxygen atoms in the form of water or carbon monoxide, rather than excessively oxidizing them to carbon dioxide. Meanwhile, the high thermal conductivity of the oxygen carrier ensures a uniform temperature distribution in the pyrolysis zone, preventing localized overheating that could lead to the condensation of large molecules into polycyclic aromatic hydrocarbons. Through this catalytic pyrolysis process, the originally high-oxygen-content, complex-structured macromolecular volatiles are partially broken down into smaller molecular weight intermediates, significantly reducing the number of oxygen-containing functional groups. This fundamentally inhibits the undesirable release of oxygen in the form of water or carbon dioxide during the subsequent reforming stage. More importantly, the "pretreatment" of macromolecular volatiles during the pyrolysis stage effectively reduces the load on the reduction reaction unit, allowing the fully oxygenated heat carrier in the reduction unit to more effectively and selectively reform the already upgraded smaller-molecule volatiles, thus increasing the yield of the target product, hydrogen. Furthermore, the pyrolysis solid products are introduced into the oxidation reaction unit along with the oxygen carrier. The pyrolysis coke burns in the presence of the heat carrier, releasing residual hydrogen in the coke as water vapor, which is then discharged with the oxygen-deficient flue gas. Simultaneously, the heat released from combustion raises the temperature of the heat carrier, achieving system heat self-sustaining and self-balancing. This method cleverly integrates the combustion behavior of pyrolysis coke into the regeneration process of the heat-carrying oxygen carrier: within the oxidation reaction unit, the heat-carrying oxygen carrier, which initially restores lattice oxygen, reacts with the oxidant to completely replenish lattice oxygen. This process is exothermic, while the pyrolysis coke undergoes vigorous combustion under high-temperature, oxygen-rich conditions. The hydrogen it contains is oxidized into water vapor, and the carbon is oxidized into carbon dioxide, both forming an oxygen-deficient flue gas exhaust system. The large amount of heat released by combustion is absorbed by the heat-carrying oxygen carrier and carried back to the reduction and catalytic pyrolysis reaction units, providing the necessary thermal energy for biomass pyrolysis and volatile matter reforming. This significantly reduces external energy input and improves the overall system's energy efficiency. From the perspective of the entire process architecture, by circulating the oxygen carrier through the pyrolysis, reduction, and oxidation reaction units, its catalytic, redox, and heat-carrying capabilities are fully utilized, effectively increasing green hydrogen yield, reducing operating load, extending the effective lifespan of the oxygen carrier, and maintaining its high catalytic activity.In summary, this method significantly improves the conversion efficiency and controllability of biomass to green hydrogen through a series of process treatments, including process decoupling, pre-catalytic pyrolysis, oxygen carrier state circulation regulation, and gas-solid separation. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a biomass catalytic pyrolysis coupled with volatile matter chemical chain reforming system for producing green hydrogen according to the present invention.

[0018] Figure 2 This is a detailed structural diagram of a biomass catalytic pyrolysis coupled with volatile matter chemical chain reforming system for producing green hydrogen according to the present invention.

[0019] Figure 3 This is a schematic diagram of the heat flow in a biomass catalytic pyrolysis coupled volatile matter chemical chain reforming system for producing green hydrogen according to the present invention.

[0020] Figure 4 This is a flowchart of a biomass catalytic pyrolysis coupled with volatile matter chemical chain reforming to produce green hydrogen.

[0021] Figure 5 This is a comparison chart of the content of light components in the macromolecules of biomass pyrolysis volatiles between the present invention and existing systems.

[0022] Figure 6 This is a comparison chart of the yield of chemical chain reforming gas from biomass pyrolysis volatiles in this invention and existing systems.

[0023] Among them, 1-pyrolysis reactor, 2-first gas-solid separator, 3-first return valve, 4-first booster fan, 5-heat exchanger, 6-oxidation reactor, 7-second gas-solid separator, 8-second return valve, 9-original reactor, 10-third gas-solid separator, 11-third return valve, 12-steam pump, 13-second booster fan, 14-water-steam conversion device, 15-acid gas removal device, 16-pressure swing adsorption device, 17-screw feeder. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0025] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0026] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0027] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper," "lower," "horizontal," or "inner" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of the invention is in use, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, terms such as "first" and "second" are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0028] Furthermore, the use of the term "horizontal" does not imply that the component must be absolutely horizontal, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0029] In the description of the embodiments of the present invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the present invention according to the specific circumstances.

[0030] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.

[0031] Example 1 See Figure 1 The present invention provides a biomass catalytic pyrolysis coupled volatile matter chemical chain reforming system for producing green hydrogen, including a catalytic pyrolysis reaction unit, a reduction reaction unit, an oxidation reaction unit and a hydrogen purification unit; The catalytic pyrolysis reaction unit is used to catalytically pyrolyze biomass to produce pyrolysis gaseous products and pyrolysis solid products. The pyrolysis gaseous products are introduced into the reduction reaction unit, and the pyrolysis solid products are introduced into the oxidation reaction unit. The pyrolysis gaseous products include volatile macromolecules and volatile small molecules. The pyrolysis solid products include pyrolysis coke and a heat carrier oxygen carrier that initially restores lattice oxygen. The oxidation reaction unit is used to oxidize the heat carrier oxygen that has initially restored lattice oxygen and to burn pyrolysis coke to obtain a heat carrier oxygen that has fully replenished lattice oxygen and oxygen-deficient flue gas. The heat carrier oxygen that has fully replenished lattice oxygen is introduced into the reduction reaction unit, and the oxygen-deficient flue gas is output and collected. The reduction reaction unit is used to reform the pyrolysis gaseous products with a heat carrier oxygen carrier that has been fully replenished with lattice oxygen to obtain hydrogen-rich syngas and a heat carrier oxygen carrier that has lost lattice oxygen. The hydrogen-rich syngas is then introduced into the hydrogen purification unit, and the heat carrier oxygen carrier that has lost lattice oxygen is introduced into the catalytic pyrolysis reaction unit to participate in the next cycle. The hydrogen purification unit is used to purify hydrogen-rich syngas to obtain green hydrogen.

[0032] This system organically integrates catalytic pyrolysis, reduction, oxidation, and hydrogen purification units to construct a closed-loop system with circulating heat-carrying and oxygen-carrying materials, spatially decoupled reaction processes, and cascaded energy utilization. By transporting reduced oxygen-carrying materials from the reduction unit to the pyrolysis unit, the system utilizes the catalytic action of these materials to catalyze the pyrolysis of biomass. This not only promotes the in-situ release of bio-hydrogen, achieving catalytic enrichment of volatile macromolecules and increasing the content of their lighter components, but also provides more readily convertible feedstock for hydrogen production in the subsequent reduction unit. Simultaneously, bio-oxygen in the volatile macromolecules migrates in-situ to the oxygen-carrying lattice during the catalytic upgrading process, achieving primary recovery of lattice oxygen and converting low-value bio-oxygen into controllably released lattice oxygen, thus realizing the efficient production of green hydrogen.

[0033] Example 2 See Figure 1 and Figure 2 The present invention provides a biomass catalytic pyrolysis coupled volatile matter chemical chain reforming system for producing green hydrogen, including a catalytic pyrolysis reaction unit, a reduction reaction unit, an oxidation reaction unit and a hydrogen purification unit; The catalytic pyrolysis reaction unit is used to catalytically pyrolyze biomass by introducing an inert fluidizing medium and a reduced oxygen carrier, producing pyrolysis gaseous products and pyrolysis solid products. The pyrolysis gaseous products are introduced into a reduction reaction unit, and the pyrolysis solid products are introduced into an oxidation reaction unit. The pyrolysis gaseous products include large and small volatile molecules; the pyrolysis solid products include pyrolysis coke and a heat-carrying oxygen carrier that has initially restored lattice oxygen. The catalytic pyrolysis reaction unit includes a pyrolysis reactor 1, a first gas-solid separator 2, and a second... The pyrolysis reactor 1 includes a return valve 3, a first booster fan 4, and a heat exchanger 5. The pyrolysis reactor 1 has a built-in oxygen carrier, and its raw material inlet is connected to a screw feeder 17. Its product outlet is connected to a first gas-solid separator 2. The solid phase outlet of the first gas-solid separator 2 is sequentially connected to the first return valve 3 and an oxidation reaction unit, while the gas phase outlet of the first gas-solid separator 2 is connected to a reduction reaction unit. The outlet of the first booster fan 4 is connected to the heat exchanger 5, and the outlet of the heat exchanger 5 is connected to the first return valve 3 and the pyrolysis reactor 1.

[0034] Preferably, the first gas-solid separator 2 is a cyclone separator. In the pyrolysis reactor 1, the catalytic effect of the reduced oxygen carrier is used to upgrade the volatile matter, significantly increasing the amount of light volatile matter. The catalytic pyrolysis process realizes the transformation of biological oxygen into lattice oxygen, achieving the recovery of primary oxygen in the oxygen carrier. The inert fluidizing medium is nitrogen or argon. The inert fluidizing medium is heated by heat exchange through the first booster fan 4 and heat exchanger 5 before entering the pyrolysis reactor 1. The temperature of the inert fluidizing medium after heat exchange is 400-600℃. The oxygen carrier is preferably a modified natural ore or metal oxide with a particle size of 0.1-0.45 mm. More preferably, the oxygen carrier is a perovskite-type oxygen carrier embedded in SBA-15 molecular sieve, denoted as LaNi. x Fe 1-x O3@SBA-15 oxygen carrier, LaNi x Fe 1-x In O3, x = 0, 0.2, 0.5, 0.8, or 1; the reduced oxygen carrier is an oxygen carrier that loses lattice oxygen at a temperature of 400-600℃ from the reduction reaction unit. The biomass raw material is agricultural, forestry, animal husbandry, and urban waste, such as wheat straw, microalgae, and sludge, and the biomass particle size is 0.45-1.5 mm.

[0035] The oxidation reaction unit is used to oxidize the heat carrier oxygen that has initially restored lattice oxygen under the action of an oxidant and to burn pyrolysis coke to obtain a heat carrier oxygen that has fully replenished lattice oxygen and oxygen-deficient flue gas. The heat carrier oxygen that has fully replenished lattice oxygen is introduced into the reduction reaction unit, and the oxygen-deficient flue gas is output and collected. The unit includes an oxidation reactor 6, a second gas-solid separator 7, a second return valve 8, and a second booster fan 13. The input end of the oxidation reactor 6 is connected to the first return valve 3; the output end of the oxidation reactor 6 is connected to the second gas-solid separator 7. The solid phase output end of the second gas-solid separator 7 is sequentially connected to the second return valve 8 and the reduction reaction unit, and the gas phase output end of the second gas-solid separator 7 is connected to the heat exchanger 5; the output end of the second booster fan 13 is connected to the oxidation reactor 6 and the second return valve 8.

[0036] Preferably, the oxidation reactor 6 is a fluidized bed reactor, and its temperature is 50-100°C higher than that of the reduction reactor 9 described below. The oxidant is air, steam or carbon dioxide, and the oxidant is input through the second booster fan 13.

[0037] The reduction reaction unit is used to reform the pyrolysis gaseous products with a heat-carrying oxygen carrier that has been fully replenished with lattice oxygen, to obtain hydrogen-rich syngas and a heat-carrying oxygen carrier that has lost its lattice oxygen. The hydrogen-rich syngas is then introduced into the hydrogen purification unit, and the heat-carrying oxygen carrier that has lost its lattice oxygen is introduced into the catalytic pyrolysis reaction unit to participate in the next cycle. The unit includes a reduction reactor 9, a third gas-solid separator 10, a third return valve 11, and a steam pump 12. The solid phase input end of the reduction reactor 9 is connected to the second return valve 8, and the gas phase input end of the reduction reactor 9 is connected to the gas phase outlet of the first gas-solid separator 2. The output end of the reduction reactor 9 is connected to the third gas-solid separator 10. The solid phase output end of the third gas-solid separator 10 is sequentially connected to the third return valve 11 and the pyrolysis reactor 1. The gas phase output end of the third gas-solid separator 10 is connected to the hydrogen purification unit. The output end of the steam pump 12 is connected to the heat exchanger 5, and the outlet of the heat exchanger 5 is connected to the third return valve 11 and the reduction reactor 9.

[0038] Preferably, the reduction reactor 9 is a fluidized bed reactor with a reaction temperature of 700-900℃, and the oxygen carrier in the reduction reactor 9 is the same oxygen carrier that completely replenishes lattice oxygen and carries heat in the oxidation reactor 6.

[0039] The hydrogen purification unit is used to purify hydrogen-rich syngas to obtain green hydrogen. It includes a water-gas shift converter 14, an acid gas removal device 15, and a pressure swing adsorption device 16. The input end of the water-gas shift converter 14 is connected to the output end of the steam pump 12 and the gas phase output end of the third gas-solid separator 10. The output end of the water-gas shift converter 14 is connected in sequence to the acid gas removal device 15 and the pressure swing adsorption device 16.

[0040] Preferably, valves are provided at the outlets of the first booster fan 4, the steam pump 12, and the second booster fan 13. Valves are provided at the gas inlet ends of the first return valve 3, the second return valve 8, and the third return valve 11, and valves are provided at the fluidizing medium gas inlet end of the pyrolysis reactor 1.

[0041] See Figure 3 and Figure 4 The specific work process is as follows: The screw feeder 17 outputs biomass raw materials to the catalytic pyrolysis reactor 1. At the same time, the first booster fan 4 is started to input inert fluidizing medium into the catalytic pyrolysis reactor 1. Under the action of oxygen carrier and inert fluidizing medium in the catalytic pyrolysis reactor 1, the biomass raw materials are catalytically pyrolyzed to produce pyrolysis gaseous products (volatile macromolecules and volatile small molecules) and pyrolysis solid products (pyrolysis coke and heat carrier oxygen carrier for preliminary recovery of lattice oxygen). The two are separated by the first gas-solid separator 2. The separated pyrolysis gaseous products are transported to the reduction reactor 9, and the pyrolysis solid products are transported to the oxidation reactor 6 through the first return valve 3. The second booster fan 13 is started to introduce oxidant into the oxidation reactor 6. Under the action of the oxidant, the heat carrier oxygen that has initially restored lattice oxygen is oxidized and the pyrolysis coke is burned, producing a heat carrier oxygen that fully replenishes lattice oxygen and oxygen-deficient flue gas. Under the action of the second gas-solid separator 7, the heat carrier oxygen that fully replenishes lattice oxygen and oxygen-deficient flue gas are separated. The heat carrier oxygen that fully replenishes lattice oxygen enters the reduction reactor 9 through the second return valve 8, and the oxygen-deficient flue gas enters the heat exchanger 5 to exchange heat with other input gases before going to the carbon capture device.

[0042] Steam is introduced into the reduction reactor 9 by starting steam pump 12. This causes the fully oxygenated heat carrier and pyrolysis gaseous products in the reduction reactor 9 to undergo a reforming reaction, producing hydrogen-rich syngas and oxygen carriers that have lost their lattice oxygen. These are then separated by the third gas-solid separator 10. The oxygen carriers that have lost their lattice oxygen are transported to the catalytic pyrolysis reactor 1 via the third return valve 11 to continue participating in the catalytic pyrolysis reaction. The hydrogen-rich syngas is then transported to the water-steam shift device 14, the acid gas removal device 15, and the pressure swing adsorption device 16 before being output as green hydrogen. The role of steam is to adjust the hydrogen-carbon ratio of the syngas. Before entering the reduction reactor 9, the steam passes through the heat exchanger 5 to exchange heat with the oxygen-deficient flue gas. After the heat exchange, the steam temperature is 150-200℃.

[0043] Among them, the catalytic pyrolysis reaction and chemical chain reforming reaction occurring in the catalytic pyrolysis reactor 1 and the reduction reactor 9 are endothermic reactions, while the pyrolysis coke combustion reaction and the oxidation reaction of the oxygen carrier occurring in the oxidation reactor 6 are exothermic reactions; the hydrogen purification process in the water-gas shift device 14, the acid gas removal device 15 and the pressure swing adsorption device 16 is an endothermic process; the heat balance of the entire system is achieved by the heat transfer carried by the circulating flow of the oxygen carrier in order to achieve heat self-sufficiency within the system; and the heat in the oxygen-deficient flue gas can be utilized through heat exchange in the heat exchanger.

[0044] Among them, the catalyst (an oxygen carrier that has lost its lattice oxygen) can improve the pyrolysis efficiency of biomass and enhance the quality of pyrolysis volatiles. In the catalytic pyrolysis reactor 1, biomass first undergoes a pyrolysis reaction, and the catalytic effect of the oxygen carrier promotes the ring-breaking of biomass pyrolysis volatiles, thereby improving pyrolysis efficiency and increasing the yield of volatiles.

[0045] In catalytic pyrolysis reactor 1, the active metal in the multifunctional oxygen carrier acts as a catalyst, catalyzing the breaking of CC and CHC bonds in the volatiles. Simultaneously, the oxygen carrier utilizes oxygen from the biomass for preliminary oxidation in situ. In the reduction reactor, the oxygen carrier, as a reactant, participates in the chemical reaction, providing controllable lattice oxygen. The rate at which the oxygen carrier releases lattice oxygen must match the rate of dissociation of the volatile macromolecules to achieve partial oxidation and produce hydrogen-rich syngas. In oxidation reactor 6, the oxygen carrier needs good high-temperature resistance, anti-sintering properties, and heat-carrying capacity. It must be able to achieve complete lattice oxygen recovery under the influence of air, while simultaneously utilizing the thermal effect of the oxygen carrier to transfer heat from oxidation reactor 6 to reduction reactor 9. Throughout the entire system, the oxygen carrier needs excellent cycle stability and good wear resistance.

[0046] Example 3 See Figure 4 The present invention also provides a method for producing green hydrogen by biomass catalytic pyrolysis coupled with volatile matter chain reforming, comprising: Biomass is introduced into a catalytic pyrolysis reaction unit and catalytically pyrolyzed under the action of an inert fluidized medium and a heat carrier and oxygen carrier to produce pyrolysis gaseous products and pyrolysis solid products. The pyrolysis gaseous products include volatile macromolecules and volatile small molecules; the pyrolysis solid products include pyrolysis coke and a heat carrier and oxygen carrier that has initially restored lattice oxygen. The pyrolysis solid products are introduced into the oxidation reaction unit, so that the heat carrier oxygen that initially restores lattice oxygen reacts with the oxidant to obtain a heat carrier oxygen that fully replenishes lattice oxygen, and the pyrolysis coke is burned in the oxidation reaction unit to produce oxygen-deficient flue gas. A heat-carrying oxygen carrier with fully replenished lattice oxygen is introduced into the reduction reaction unit, and the pyrolysis gaseous products are introduced into the reduction reaction unit to undergo a reforming reaction with the heat-carrying oxygen carrier with fully replenished lattice oxygen, to obtain hydrogen-rich syngas and a heat-carrying oxygen carrier that has lost lattice oxygen. The heat-carrying oxygen carrier that has lost its lattice oxygen is introduced into the catalytic pyrolysis reaction unit to catalyze the pyrolysis of biomass and participate in the next cycle; Hydrogen-rich syngas is introduced into a hydrogen purification unit for hydrogen purification to obtain green hydrogen.

[0047] To further illustrate the beneficial effects of the present invention, a comparison is made with the system involved in Chinese invention patent with publication number CN114350411B. The biomass raw material used in both cases is wheat straw (WS), and the elemental analysis of the raw materials is shown in the table below.

[0048] raw material Coke production / wt% C / % H / % O / % Hydrogen production rate / % Carbon production rate / % biomass / 44.09 7.14 46.95 / / 500℃ pyrolysis coke 30.8 54.49 2.36 40.96 89.72 55.69 500℃ Catalytic Pyrolysis Coke - C / B 0.2 28.78 64.40 2.63 31.12 93.30 59.68 500℃ Catalytic Pyrolysis Coke - C / B 0.4 26 54.49 2.36 40.96 94.29 62.03 500℃ catalytic pyrolysis coke - C / B 0.6 25.66 65.68 2.83 29.88 93.90 62.48 A three-circulation fluidized bed process for preparing green hydrogen by biomass catalytic pyrolysis coupled with volatile matter chain reforming is expected to achieve self-heating operation of the system. The main energy flow includes the following steps: The process involves multiple stages of pyrolysis, combustion, reforming, and oxidation reactions, and is expected to achieve efficient hydrogen production while realizing energy cascade utilization.

[0049] Catalytic pyrolysis reactor 1: Inert fluidized carrier gas (N2, Ar) is preheated to 300 °C (E1) via heat exchanger 5. The required heat is recovered from the waste heat of the oxygen-deficient flue gas at the outlet of oxidation reactor 6. It is returned to the heat-carrying oxygen carrier at a temperature of approximately 400-600 °C (E2) via the third return valve 11. Simultaneously, the volatiles in the pyrolysis reactor oxidize the oxygen carrier, achieving primary oxygen replenishment, which is an exothermic reaction. In this process, the endothermic reaction of biomass catalytic pyrolysis consumes energy, producing volatiles and pyrolytic coke.

[0050] Oxidation reactor 6: Ambient temperature air is compressed by an air compressor and enters oxidation reactor 6 to react with pyrolysis coke to generate oxygen-deficient flue gas and release heat, approximately 18 MJ·kg. -1 Simultaneously, the primary oxidizing oxygen carrier (such as Fe3O4, 750°C) undergoes a complete oxidation reaction, converting Fe3O4 to Fe2O3 and releasing heat to maintain the reactor temperature at 900°C. Finally, the produced oxygen-deficient flue gas (containing CO2, temperature 800°C) carries sensible heat into heat exchanger 5, preheating the inert carrier gas to 300°C and the steam to 200°C, while the fully oxidized oxygen carrier carries the heat into reduction reactor 9.

[0051] Reduction reactor 9: Superheated steam (200°C) exchanged with the oxygen-deficient flue gas in heat exchanger 5 provides some heat for the reaction and promotes the water-gas reaction (E3). The oxygen carrier carrying sensible heat returns from air oxidation reactor 6 at approximately 850°C (E4). The partial oxidation of volatile macromolecules releases heat, while the steam reforming reaction absorbs heat; the required external heat is supplemented by the sensible heat of the oxygen carrier. Ultimately, the resulting hydrogen-rich synthesis provides an important feedstock for subsequent green hydrogen production.

[0052] The steam-water shift converter 14 is used to convert CO in the hydrogen-rich synthesis gas produced by the reduction reactor 9 into CO2, so that the gas mainly consists of hydrogen and CO2. Taking a feed gas composition of CO: 15 vol%, CO2: 10 vol%, H2: 50 vol%, CH4: 5 vol%, H2S: 1 vol%, with the remainder being N2 and H2O, the feed gas is introduced into the steam-water shift converter 14. The high-temperature section of the steam-water shift converter 14 uses a chromium-stabilized iron oxide catalyst (comprising 74.2% Fe2O3 and 10% Cr2O3 by mass percentage), with a reaction temperature of 350℃, a pressure of 2.0 MPa, and a space velocity of 3000 h⁻¹. -1 The water-to-air ratio is 2.5. The low-temperature section uses a copper-zinc-aluminum composite oxide (comprising 32%-33% CuO, 34%-53% ZnO, and 15%-33% Al2O3 by mass percentage), with a reaction temperature of 200℃, a pressure of 2.0 MPa, and a space velocity of 2500 h⁻¹. -1 When the CO content in the hydrogen-rich syngas is 10%, the total conversion rate is ≥99.5%, the outlet CO content is <0.1%, and the hydrogen concentration is increased to 60 vol.

[0053] The gas passing through the water-gas shift device 14 is then passed into the acid gas removal device 15 to remove acidic gases, resulting in purified gas mainly composed of H2 and CO2. The pressure swing adsorption device 16 is equipped with a packed tower, which functions as both an absorption tower and a desorption tower by changing the pressure. The packed tower is a stainless steel structured packed tower, operating at a pressure of 1.8 MPa and an operating temperature of approximately 40°C. The absorbent in the absorption tower can be a 20wt%~30wt% MDEA solution, with a circulation rate of 5~10 m³ / s. 3 ·h -1 During desorption, steam at 120℃ is introduced, the desorption pressure is 0.2 MPa, and the CO2 load of the lean solution is <0.1 mol·mol⁻¹. -1 After this treatment, the H2S content in the outlet gas is less than 5 ppm. Simultaneously, the CO2 released after the rich liquid regeneration is transported to the carbon capture unit via pipeline.

[0054] After the acidic gases are removed, the mixed gas is passed through a pressure swing adsorption (PSA) unit 16 to extract high-purity hydrogen. This can be achieved using a four-tower parallel configuration: the upper layer of the adsorption tower is packed with 13X molecular sieves (1-2 mm particle size), and the lower layer is packed with activated alumina (2-3 mm particle size) in a 7:3 volume ratio. The adsorption pressure is 0.5-3 MPa, and the desorption pressure is atmospheric pressure / vacuum. The adsorption time is 60-120 s, and the desorption time is 30-60 s. The temperature range is 20-80℃. The feed gas contains approximately 90% hydrogen, with the remaining components mainly being CO2. Through PSA, the hydrogen purity is ≥99.99%, the recovery rate is ≥85%, and the CO2 removal rate is ≥95%.

[0055] Based on the energy balance analysis of the entire system, the chemical energy input from the biomass is 20 MJ·kg⁻¹. -1 Of the total pyrolysis, volatile matter accounted for 60%, and pyrolysis coke accounted for 40%. The heat released by the combustion of pyrolysis coke was 18 MJ·kg⁻¹. -1 The chemical energy yield of the syngas is 10 MJ·Nm³. -3 The waste heat recovery rate is approximately 35%, and the system's net energy efficiency is approximately 65%. This process achieves efficient hydrogen production while simultaneously realizing energy recycling and environmental protection, demonstrating promising application prospects.

[0056] Compared with the system disclosed in Chinese Invention Patent No. CN114350411B, the biomass raw material used in both cases was wheat straw (WS), and the elemental analysis of the raw material is shown in Table 1. Performance evaluation was conducted in a two-stage reactor; the first stage had an inner diameter of 22 mm, and the second stage had an inner diameter of 15 mm. Pyrolysis and catalytic pyrolysis reactions were carried out in the pyrolysis reactor, with rapid pyrolysis achieved using a basket configuration. 0.5 g of WS was weighed and placed in the basket. When the temperature reached 600°C, the WS was rapidly pushed into the reaction zone. In the second-stage reactor, a chemical chain reforming reaction was carried out, and 0.75 g of OCs was placed on the reactor's built-in sieve plate. The volatiles produced by pyrolysis were entrained by argon gas and reacted with the oxygen carrier. After 20 min of reaction, the basket was moved to a low-temperature zone. The atmosphere was then switched to simulated air (21% O2 and 79% N2) for complete reoxidation of the OCs, with a reoxidation time of 20 min. Subsequently, argon gas was purged into the reactor for 30 min to avoid any impact on the subsequent chemical chain reaction. The product gases were absorbed by acetone in a cold trap, dried, and then collected in an aluminum foil gas bag. The composition and relative content of the liquid products were analyzed using gas chromatography-mass spectrometry (GCMS-QP2020NX, column model SH-Rxi-5Sil MS), while the gaseous products were determined using gas chromatography (FULI9790, equipped with an FID detector and a TCD detector). As shown in the table, the pyrolysis coke yield in the comparative test was 30.8 wt%, with approximately 11% hydrogen present in the pyrolysis coke. This method can reduce the pyrolysis coke yield to 26.0 wt%, while reducing the hydrogen content fixed in the coke to approximately 5%. See also... Figure 5 The content of light components in the macromolecules of biomass pyrolysis volatiles was compared between the two methods. The results showed that the light component content in this application was significantly increased from 11.5% in the comparative test to 60.6%, reducing the difficulty of subsequent chemical chain reforming and improving hydrogen production efficiency. See also... Figure 6 The yields of the target products obtained from the chemical chain reforming of biomass pyrolysis volatiles were compared between the two methods. The study showed that this method can improve the final hydrogen yield (approximately 63.7 mL·g) compared to the comparative test. WS -1 ) and syngas yield (approximately 62.7 mL·g)WS -1 ).

[0057] The above description is merely a preferred embodiment of the present invention and is not intended to limit the technical solution of the present invention in any way. Those skilled in the art should understand that, without departing from the spirit and principles of the present invention, the technical solution can be modified and replaced in several simple ways, and these modifications and replacements are all within the scope of protection covered by the claims.

Claims

1. A biomass catalytic pyrolysis coupled with volatile matter chain reforming system for producing green hydrogen, characterized in that, It includes a catalytic pyrolysis reaction unit, a reduction reaction unit, an oxidation reaction unit, and a hydrogen purification unit; The catalytic pyrolysis reaction unit is used to catalytically pyrolyze biomass to produce pyrolysis gaseous products and pyrolysis solid products. The pyrolysis gaseous products are introduced into the reduction reaction unit, and the pyrolysis solid products are introduced into the oxidation reaction unit. The pyrolysis gaseous products include volatile macromolecules and volatile small molecules. The pyrolysis solid products include pyrolysis coke and a heat carrier oxygen carrier that initially restores lattice oxygen. The oxidation reaction unit is used to oxidize the heat carrier oxygen that has initially restored lattice oxygen and to burn pyrolysis coke to obtain a heat carrier oxygen that has fully replenished lattice oxygen and oxygen-deficient flue gas. The heat carrier oxygen that has fully replenished lattice oxygen is introduced into the reduction reaction unit, and the oxygen-deficient flue gas is output and collected. The reduction reaction unit is used to reform the pyrolysis gaseous products with a heat carrier oxygen carrier that has been fully replenished with lattice oxygen to obtain hydrogen-rich syngas and a heat carrier oxygen carrier that has lost lattice oxygen. The hydrogen-rich syngas is then introduced into the hydrogen purification unit, and the heat carrier oxygen carrier that has lost lattice oxygen is introduced into the catalytic pyrolysis reaction unit to participate in the next cycle. The hydrogen purification unit is used to purify hydrogen-rich syngas to obtain green hydrogen.

2. The biomass catalytic pyrolysis coupled with volatile matter chemical looping reforming system for producing green hydrogen according to claim 1, characterized in that, The catalytic pyrolysis reaction unit includes a pyrolysis reactor (1), a first gas-solid separator (2), and a first return valve (3); the pyrolysis reactor (1) has an internal oxygen carrier, and the product outlet of the pyrolysis reactor (1) is connected to the first gas-solid separator (2). The solid phase outlet of the first gas-solid separator (2) is connected in sequence to the first return valve (3) and the oxidation reaction unit, and the gas phase outlet of the first gas-solid separator (2) is connected to the reduction reaction unit.

3. The biomass catalytic pyrolysis coupled with volatile matter chemical looping reforming system for producing green hydrogen according to claim 2, characterized in that, The catalytic pyrolysis reaction unit also includes a first booster fan (4) and a heat exchanger (5), with the outlet of the first booster fan (4) connected in sequence to the heat exchanger (5) and the pyrolysis reactor (1).

4. The biomass catalytic pyrolysis coupled with volatile matter chemical looping reforming system for producing green hydrogen according to claim 3, characterized in that, The oxidation reaction unit includes an oxidation reactor (6), a second gas-solid separator (7), and a second return valve (8). The input end of the oxidation reactor (6) is connected to the first return valve (3). The output end of the oxidation reactor (6) is connected to the second gas-solid separator (7). The solid phase output end of the second gas-solid separator (7) is connected to the second return valve (8) and the reduction reaction unit in sequence. The gas phase output end of the second gas-solid separator (7) is connected to the heat exchanger (5).

5. The biomass catalytic pyrolysis coupled with volatile matter chemical looping reforming system for producing green hydrogen according to claim 4, characterized in that, The oxidation reaction unit also includes a second booster fan (13), the output end of which is connected to the oxidation reactor (6).

6. The biomass catalytic pyrolysis coupled with volatile matter chemical looping reforming system for producing green hydrogen according to claim 5, characterized in that, The reduction reaction unit includes a reduction reactor (9), a third gas-solid separator (10), and a third return valve (11). The solid phase input end of the reduction reactor (9) is connected to the second return valve (8), and the gas phase input end of the reduction reactor (9) is connected to the gas phase outlet of the first gas-solid separator (2). The output end of the reduction reactor (9) is connected to the third gas-solid separator (10). The solid phase output end of the third gas-solid separator (10) is connected in sequence to the third return valve (11) and the pyrolysis reactor (1). The gas phase output end of the third gas-solid separator (10) is connected to the hydrogen purification unit.

7. The biomass catalytic pyrolysis coupled with volatile matter chemical loop reforming system for producing green hydrogen according to claim 6, characterized in that, The reduction reaction unit also includes a steam pump (12), the output end of which is connected in sequence to a heat exchanger (5) and a reduction reactor (9).

8. The biomass catalytic pyrolysis coupled with volatile matter chemical looping reforming system for producing green hydrogen according to claim 7, characterized in that, The hydrogen purification unit includes a water vapor shift device (14), an acid gas removal device (15), and a pressure swing adsorption device (16). The input end of the water vapor shift device (14) is connected to the output end of the steam pump (12) and the gas phase output end of the third gas-solid separator (10). The output end of the water vapor shift device (14) is connected in sequence to the acid gas removal device (15) and the pressure swing adsorption device (16).

9. The biomass catalytic pyrolysis coupled with volatile matter chemical looping reforming system for producing green hydrogen according to claim 8, characterized in that, Valves are provided at the outlets of the first booster fan (4), the steam pump (12), and the second booster fan (13).

10. A method for producing green hydrogen from biomass through catalytic pyrolysis coupled with volatile matter chain reforming, characterized in that, include: Biomass is introduced into a catalytic pyrolysis reaction unit and catalytically pyrolyzed under the action of an inert fluidized medium and a heat carrier and oxygen carrier to produce pyrolysis gaseous products and pyrolysis solid products. The pyrolysis gaseous products include volatile macromolecules and volatile small molecules; the pyrolysis solid products include pyrolysis coke and a heat carrier and oxygen carrier that has initially restored lattice oxygen. The pyrolysis solid products are introduced into the oxidation reaction unit, so that the heat carrier oxygen that initially restores lattice oxygen reacts with the oxidant to obtain a heat carrier oxygen that fully replenishes lattice oxygen, and the pyrolysis coke is burned in the oxidation reaction unit to produce oxygen-deficient flue gas. A heat-carrying oxygen carrier with fully replenished lattice oxygen is introduced into the reduction reaction unit, and the pyrolysis gaseous products are introduced into the reduction reaction unit to undergo a reforming reaction with the heat-carrying oxygen carrier with fully replenished lattice oxygen, to obtain hydrogen-rich syngas and a heat-carrying oxygen carrier that has lost lattice oxygen. The heat-carrying oxygen carrier that has lost its lattice oxygen is introduced into the catalytic pyrolysis reaction unit to catalyze the pyrolysis of biomass and participate in the next cycle; Hydrogen-rich syngas is introduced into a hydrogen purification unit for hydrogen purification to obtain green hydrogen.

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