Multi-generation system and method for coupling wind-solar hydrogen production with CO2 capture and utilization

Abstract

The invention provides a polygeneration system and method for coupling wind-solar hydrogen production with CO2 capture and utilization, and relates to the technical field of green energy. The system comprises a renewable energy source driving subsystem used for providing green electric energy and preparing green hydrogen as an energy carrier and a synthetic raw material to be supplied to a multi-path utilization subsystem; the carbon source conversion and capture subsystem is used for receiving the biomass raw material, generating gasified synthesis gas and biomass charcoal through gasification reaction, and capturing and recycling CO2 in flue gas discharged by the system; the multi-path utilization subsystem is used for receiving H2, the gasified synthesis gas and CO2 and blending reaction components to realize synthesis of green methanol, conventional methanol and green ammonia; closed-loop circulation of carbon resources is formed among the subsystems through continuous conversion, capture and feedback paths of H2, CO2 and biomass charcoal. According to the scheme, efficient synergistic conversion of hydrogen and carbon resources and full-amount utilization of carbon elements can be achieved in regions with limited carbon sources.

Description

Technical Field

[0001] The present disclosure relates to the field of green energy technology, and in particular to a polygeneration system and method for wind-solar hydrogen production coupled with CO2 capture and utilization. Background Art

[0002] With the widespread use of renewable energy, the traditional energy structure is gradually being reshaped, becoming the core support for achieving the goals of carbon peak and carbon neutrality. However, wind and solar energy, as the main forms of renewable energy, have significant volatility and intermittent characteristics. As a result, their power output fluctuates significantly with time and meteorological conditions, making it difficult to adapt to stable and continuous industrial loads. As one of the important ways to consume green electricity, water electrolysis hydrogen production technology has become an important direction in the current energy conversion field because it can directly convert electrical energy into hydrogen energy. However, as a secondary energy source with poor storage and transportation performance, hydrogen faces significant constraints in its production, storage and transportation. In particular, liquefaction storage and transportation require an extremely low temperature of -253°C, high energy consumption, high cost, and high requirements for supporting infrastructure. As a result, the downstream application benefits of the hydrogen production pathway are difficult to fully release. Therefore, it is necessary to explore coupled chemical synthesis pathways in the post-hydrogen production link to achieve on-site conversion of hydrogen energy and improve its transportability and economic value in the system.

[0003] In addition, carbon dioxide, as a typical greenhouse gas, is inevitably produced in many types of industrial processes, especially in biomass pyrolysis, synthesis reaction tail gas, coal-fired power combustion and other links. In traditional technical paths, most processes treat CO2 as waste gas emissions, with low recovery and utilization rates, and fail to effectively incorporate it into the energy or production raw material system, which not only causes a waste of carbon resources, but also affects the environmental performance indicators of the system. Especially in areas such as deserts and Gobi, where wind and light resources are abundant but carbon sources are scarce, it is particularly urgent to build an energy and material cogeneration system suitable for "rich electricity and poor carbon" scenarios. In such areas, the traditional carbon supply system based on coal, natural gas, etc. is difficult to achieve sustainable deployment, and the cost of transporting carbon sources is high and the environmental cost is high.

[0004] Therefore, the energy coupling and carbon resource utilization systems in related technologies generally have problems such as a single hydrogen energy utilization path, low carbon source organization efficiency, insufficient added value of biomass products, and low level of tail gas resource recovery and utilization. There is an urgent need to develop a new multi-product technology system with high system integration, close path coordination, and strong carbon source closed-loop utilization capability to adapt to the needs of coordinated transformation and efficient utilization of green energy and carbon resources under the background of new energy dominance.

[0005] It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present disclosure, and therefore may include information that does not constitute prior art known to ordinary technicians in the field. Summary of the Invention

[0006] The purpose of the embodiments of the present disclosure is to provide a multi-generation system and method for wind-solar hydrogen production coupled with CO2 capture and utilization, thereby enabling efficient synergistic conversion of hydrogen and carbon resources and full utilization of carbon elements in areas with limited carbon sources.

[0007] Other features and advantages of the present disclosure will become apparent from the following detailed description, or may be learned in part by practice of the present disclosure.

[0008] According to a first aspect of an embodiment of the present disclosure, a polygeneration system for wind-solar hydrogen production coupled with CO2 capture and utilization is provided, comprising: The renewable energy drive subsystem is used to provide green electricity generated by wind power generation, photovoltaic power generation, and solar thermal power generation, and to produce green hydrogen by water electrolysis. The green hydrogen is supplied to the multi-path utilization subsystem as an energy carrier and synthetic raw material; A carbon source conversion and capture subsystem is used to receive biomass feedstock and generate gasification synthesis gas containing H2, CO, CO2, and CH4 through a gasification reaction, while also producing biomass char; the carbon source conversion and capture subsystem is also used to capture CO2 from green methanol tail gas combustion flue gas and coal-fired power flue gas, and respectively feed the captured renewable CO2 and coal-based CO2 into the multi-path utilization subsystem or the renewable energy drive subsystem; a multi-path utilization subsystem for receiving H2, the gasification synthesis gas, and CO2, adjusting reaction components to achieve the synthesis of green methanol, conventional methanol, and green ammonia, and utilizing the biochar to process and prepare a carbon-based denitrification catalyst for internal flue gas purification in the system, and forming a closed-loop thermal energy and reaction coupling channel between the multi-path utilization subsystem and the renewable energy drive subsystem through the supply of electricity and pure oxygen; Among them, the continuous conversion, capture and feedback paths of H2, CO2 and biochar between each subsystem form a closed-loop cycle of carbon resources. The input carbon sources are converted into green methanol, conventional methanol or carbon-based denitrification catalyst to achieve the full utilization of carbon sources and the multi-generation goal of near-zero emissions.

[0009] In some example embodiments of the present disclosure, based on the aforementioned solution, the renewable energy drive subsystem includes a wind power generation module, a photovoltaic and solar thermal power generation module, and a green hydrogen production module; The wind power generation module and the photovoltaic and solar thermal power generation module are used to produce green electricity; The green hydrogen production module includes one or more combinations of an alkaline water electrolysis hydrogen production device, a proton exchange membrane water electrolysis hydrogen production device or a solid oxide water electrolysis hydrogen production device, which is used to generate green hydrogen through the green electricity, supply the green hydrogen to the multi-path utilization subsystem, and supply the by-product pure oxygen to the carbon source conversion and capture subsystem as a combustion-supporting gas.

[0010] In some example embodiments of the present disclosure, based on the foregoing scheme, the renewable energy driving subsystem includes a CO2 energy storage module, which is used to recycle the captured coal-based CO2 as a working medium by the carbon source conversion and capture subsystem, to achieve energy storage and release by a compression-expansion cycle, and the required electric energy is provided by the wind power module and the photovoltaic and photo-thermal power module, for adjusting the load fluctuation of the green hydrogen production module.

[0011] In some example embodiments of the present disclosure, based on the foregoing scheme, the multi-path utilization subsystem includes: A green methanol synthesis device is used to receive green hydrogen, gasified synthesis gas, and renewable CO2 provided by the carbon source conversion and capture subsystem, to adjust the components for catalytic synthesis, and to obtain green methanol; A conventional methanol synthesis device is used to synthesize conventional methanol from coal-based CO2 and green hydrogen; A green ammonia synthesis device is used to receive green hydrogen and N2 of the air separation system device for ammonia synthesis reaction to obtain green ammonia.

[0012] In some example embodiments of the present disclosure, based on the foregoing scheme, the carbon source conversion and capture subsystem includes: An air separation device is used to produce N2 and medical O2, wherein the N2 is used for the green ammonia production module and the gasification agent of the biomass gasification device; A flue gas treatment device is used to purify the flue gas discharged by the system after heat utilization; A CO2 capture device is connected with the flue gas treatment device, which is used to capture CO2 in the flue gas after purification treatment, and the renewable CO2 therein is supplied to the green methanol synthesis device, the conventional methanol device, or the CO2 energy storage module; A biomass gasification device includes a biomass gasification furnace, a raw material inlet, a gasification agent inlet, a gasified synthesis gas outlet, and a biomass char outlet. The biomass gasification device uses agricultural and forestry biomass as raw material, uses N2-H2O mixed gas produced from the air separation device and heated by the flue gas treatment device as a gasification agent, and generates gasified synthesis gas and biomass char under the condition of 450-550℃. The gasified synthesis gas is used for green methanol synthesis, and the biomass char is used for preparing carbon-based denitration catalyst.

[0013] In some example embodiments of the present disclosure, based on the foregoing scheme, the carbon source conversion and capture subsystem further includes a biomass char utilization module; The biochar utilization module is used to prepare a carbon-based denitration catalyst by using the biochar as a carrier through impregnation and loading of denitration active components. The carbon-based denitration catalyst is reused in the SCR denitration process in the flue gas treatment device. The heat energy required in the preparation process of the carbon-based denitration catalyst is obtained by waste heat exchange from the flue gas treatment device.

[0014] In some exemplary embodiments of the present disclosure, based on the aforementioned solution, the polygeneration system further includes a coal-fired power combustion module, and the flue gas treatment device includes: The first flue gas treatment unit is used to use the pure oxygen output by the green hydrogen production module as a combustion aid to burn the combustible gas discharged from the green methanol synthesis device to achieve CO2 enrichment and recover heat energy, and to perform desulfurization, denitrification and dust removal purification treatment on the flue gas after sufficient combustion; The second flue gas treatment unit is used to perform desulfurization, denitrification and dust removal purification treatment on the flue gas discharged from the coal-fired power combustion module and after heat utilization.

[0015] In some exemplary embodiments of the present disclosure, based on the aforementioned solution, the CO2 capture device includes: a first CO2 capture unit connected to the first flue gas treatment unit, configured to use the flue gas discharged from the first flue gas treatment module as a raw material and CaO as a medium, to obtain renewable CO2 through adsorption, calcination, and collection, and to deliver the captured renewable CO2 to the green methanol synthesis unit as a green carbon source to supplement the carbon elements required for the reaction; The second CO2 capture unit is connected to the second flue gas treatment unit, and is used to use the flue gas discharged from the second flue gas treatment module as raw material and CaO as the medium to obtain coal-based CO2 after adsorption, calcination and collection, and to transport the captured coal-based CO2 to a conventional methanol synthesis unit, a CO2 energy storage module and the preparation of compressed CO2 products.

[0016] In some example embodiments of the present disclosure, based on the aforementioned scheme, the polygeneration system further includes a product storage module, which is connected to the green methanol synthesis unit, the conventional methanol synthesis unit, the green ammonia synthesis unit, the CO2 capture module, the air separation unit and the biomass charcoal utilization module, and is used to collect and store the produced green hydrogen, conventional methanol, green methanol, green ammonia, compressed CO2, pure oxygen, medical oxygen and carbon-based denitrification catalyst.

[0017] According to a second aspect of an embodiment of the present disclosure, a polygeneration method for wind-solar hydrogen production coupled with CO2 capture and utilization is provided. The method can be used in the polygeneration system for wind-solar hydrogen production coupled with CO2 capture and utilization in the first aspect. The method includes: The green electricity production is realized through the renewable energy driving subsystem, and dynamic adjustment is performed according to the load demand of the green hydrogen preparation module, the time-of-use electricity price, the relationship between the required power of the CO2 energy storage module and the produced power, so as to realize the adaptation between new energy power generation, green electricity grid connection, electricity storage, green hydrogen preparation, power consumption and economy; The green hydrogen and pure oxygen are produced through the water electrolysis process of the green hydrogen preparation module, the green hydrogen is separated, purified and pressurized to prepare high-purity hydrogen, and the pretreated H2 is sent to the conventional methanol synthesis device and the green ammonia synthesis device according to the quality requirements of the conventional methanol synthesis device and the green ammonia synthesis device for H2; The broken and preheated agricultural and forestry biomass is used as raw material, N2-H2O mixed gas is used as a gasifying agent, and gasification synthesis gas and biomass char are generated at 450-550 DEG C through the biomass gasification device, and the gasification synthesis gas is sent to the green methanol synthesis device, and the biomass char is sent to the biomass char utilization module to prepare a carbon-based denitration catalyst; The green hydrogen produced by the green hydrogen preparation module, the gasification synthesis gas produced by the biomass gasification device and the renewable CO2 recovered by the first CO2 capture unit are used as inputs of the green methanol synthesis device, and the volume ratio of H2, CO and CO2 in the green methanol synthesis device is adjusted to catalytically synthesize green methanol; The prepared carbon-based denitration catalyst is input into the first flue gas treatment unit and the second flue gas treatment unit to remove nitrogen oxides, so as to realize the standard discharge of nitrogen oxides in the flue gas, and the heat replaced by heat exchange and cooling in the first flue gas treatment unit is used for heating N2 separated by the air separation device, and is used for heating, heat preservation and / or preheating in the production process of the green hydrogen preparation module, the conventional methanol synthesis device and the green ammonia synthesis device; The byproduct pure oxygen produced by the green hydrogen preparation module is used as a combustion-supporting agent and is sent to the first flue gas treatment unit, so as to ensure that the first flue gas treatment unit fully burns the combustible gas discharged from the green methanol synthesis device in a pure oxygen environment, air is not introduced as a gasifying agent, and part of the remaining pure oxygen is sent to the coal-fired power module as a supplement to the air combustion-supporting agent in the coal-fired power module; The renewable CO2 captured by the first CO2 capture unit is sent to the green methanol synthesis device, and the coal-based CO2 in the coal-fired flue gas captured by the second CO2 capture unit is sent to the conventional methanol synthesis device; The produced green hydrogen, conventional methanol, green methanol, green ammonia, compressed CO2, pure oxygen, medical oxygen and carbon-based denitration catalyst are collected and stored through the product collection and storage module.

[0018] The technical scheme provided by the embodiments of the present disclosure can have the following beneficial effects: In the example embodiment of the present disclosure, the wind-solar hydrogen production coupled with CO2 capture and utilization multi-generation system realizes flexible regulation of energy and carbon source dual channels and adaptive matching within the system at the overall architecture level through the functional coordination among the renewable energy drive subsystem, the carbon source conversion and capture subsystem and the multi-path utilization subsystem; in the energy supply path, the renewable energy drive subsystem realizes direct coupling with green electricity through the green hydrogen preparation path, avoiding the economic and safety problems caused by temperature control, energy consumption and equipment costs in the traditional hydrogen liquefaction and long-distance transportation process, and improving the scenario applicability of hydrogen energy and the efficiency of on-site resource conversion; in the carbon source organization path, by taking biomass gasification as The core carbon source conversion mechanism combines the N2-H2O mixed gas supplied by the air separation system and heated by the heat exchange system as a gasifying agent. On the basis of ensuring the stability of the synthesis gas components, the adjustability of the hydrogen-carbon ratio in the reaction product is improved, thereby enhancing the adaptability of the downstream methanol synthesis path to raw material fluctuations, and effectively alleviating the structural constraints of related biomass gasification technologies in tar control, gas production corrosiveness and component unevenness. At the same time, the solid biomass char generated in the system is not treated as conventional fuel, but enters the carbon-based denitrification catalyst preparation path, realizing the high-value utilization of solid carbon sources, improving the comprehensive conversion rate of raw materials, and improving the full utilization of carbon sources in the system. In terms of system carbon cycle, By separately capturing CO2 from green methanol tail gas and coal-fired power flue gas, and guiding renewable CO2 and coal-based CO2 to the green methanol synthesis path or conventional methanol path respectively, it not only effectively avoids the single-use problem of CO2 after capture in the traditional co-production system, but also realizes the re-input and reaction reuse of carbon source after recovery at the synthesis end, improves the carbon closed-loop capability of the system, and further improves the utilization rate of carbon source in the system; on the other hand, the by-product oxygen in the green hydrogen preparation process is not discharged, but flows back to the tail gas treatment path in the system as a combustion aid, and replaces the traditional air combustion by pure oxygen combustion, which significantly reduces the emission of nitrogen oxides while increasing the CO2 concentration in the flue gas, thus paving the way for subsequent The CO2 capture process creates better original flue gas conditions, and provides heat support for gasification agent heating and multiple synthesis links through the cascade recovery of thermal energy, thereby improving the internal circulation and thermal efficiency of the system energy; further, in desert and Gobi areas where wind and solar resources are abundant but traditional carbon resources are scarce, through the joint deployment of renewable hydrogen sources, local biomass carbon sources and tail gas CO2 resources, a hydrogen-carbon coordinated supply mechanism is established without the need for large-scale carbon resource transportation, fundamentally improving the industrial conversion capacity of clean energy in remote areas, and constructing a multi-generation system with in-situ synthesis capabilities for areas with unbalanced energy resource endowments, so as to realize the joint production of multiple energy products under resource constraints.

[0019] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings are incorporated into and constitute a part of the specification, illustrate embodiments consistent with the present disclosure, and together with the specification, are used to explain the principles of the present disclosure. Obviously, the drawings described below are only some embodiments of the present disclosure, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0021] Figure 1 The schematic diagram shows the composition of a polygeneration system combining wind-solar hydrogen production and CO2 capture and utilization according to some embodiments of the present disclosure.

[0022] Figure 2 The schematic diagram shows the energy flow path and material flow path of the polygeneration system of wind-solar hydrogen production coupled with CO2 capture and utilization according to some embodiments of the present disclosure.

[0023] Figure 3 The following schematically illustrates the steps of a polygeneration method for coupling wind-solar hydrogen production with CO2 capture and utilization according to some embodiments of the present disclosure. DETAILED DESCRIPTION

[0024] Exemplary embodiments will be described in detail herein, with examples illustrated in the accompanying drawings. In the following description, when referring to the drawings, identical numerals in different figures represent identical or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments are not intended to represent all embodiments consistent with this specification. Rather, they are merely examples of apparatus and methods consistent with certain aspects of this specification, as detailed in the appended claims.

[0025] In addition, the described features, structures or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present disclosure. However, those skilled in the art will appreciate that the technical solutions of the present disclosure can be practiced without one or more of the specific details, or other methods, components, devices, steps, etc. can be adopted. In other cases, well-known methods, devices, implementations or operations are not shown or described in detail to avoid blurring various aspects of the present disclosure.

[0026] Furthermore, the drawings are schematic illustrations only and are not necessarily drawn to scale. The block diagrams shown in the drawings are merely functional entities and do not necessarily correspond to physically separate entities. In other words, these functional entities may be implemented in software, in one or more hardware modules or integrated circuits, or in different networks and / or processor devices and / or microcontroller devices.

[0027] In this example embodiment, a multi-generation system of wind-solar hydrogen production coupled with CO2 capture and utilization is first provided. The multi-generation system of wind-solar hydrogen production coupled with CO2 capture and utilization can be applied to a variety of regional deployment environments with a renewable energy resource base but limited carbon source input, especially in scenarios where wind energy and light conditions are good and traditional fossil carbon sources are insufficient. It has significant advantages. For example, it can be applied to areas with concentrated wind and solar resources, including deserts, Gobi, and semi-arid hilly areas. These areas often have large areas of land that can be used for centralized photovoltaic and wind power installations, and at the same time have a certain scale of agricultural and forestry residue resources as renewable carbon source input. In addition, it can also be applied to heavy industrial parks that have a coal-fired power resource base but are in urgent need of building a carbon emission reduction path. By synergistically utilizing CO2-rich flue gas in industrial exhaust and external green electricity and green hydrogen resources, localized green synthetic product preparation and carbon resource recycling and reuse can be achieved, forming an integrated "green electricity + green hydrogen + carbon resource" industry closed-loop path. Of course, the system can also be deployed in areas such as islands and remote pastoral areas where energy acquisition relies on external transportation and the fossil energy supply chain is weak. By building wind and solar power generation facilities and hydrogen production synthesis systems on site, an integrated energy solution of "source-grid-load-storage-production" can be realized to ensure energy self-sufficiency, multi-level resource utilization and clean product output. It is a green synthesis basic platform with strong adaptability, flexible deployment and outstanding carbon-hydrogen resource linkage capabilities.

[0028] refer to Figure 1 As shown, the wind-solar hydrogen production coupled with CO2 capture and utilization polygeneration system 100 may include a renewable energy drive subsystem 110, a multi-path utilization subsystem 120, and a carbon source conversion and capture subsystem 130, wherein: The renewable energy drive subsystem 110 serves as the system's energy input and hydrogen production foundation. Its core function is to stably convert fluctuating renewable energy into controllable energy and material carriers. The renewable energy drive subsystem captures natural renewable energy through wind power, photovoltaic power generation, and solar thermal power generation, and feeds this energy into a water electrolysis device to generate green hydrogen. Wind power generation can use horizontal-axis or vertical-axis wind turbines, which convert kinetic energy into electrical energy by driving a generator through blade rotation, and are suitable for areas with high wind speeds and low building shade. Photovoltaic power generation can use solar panels to directly convert light energy into direct current, and output a stable current through an inverter. Concentrated solar power generation can use trough collectors or tower heliostat arrays to focus solar radiation heat to heat the working fluid. For example, the heating working fluid of the tower heliostat array is high-temperature molten salt, and the heating working fluid of the trough collector is thermal oil. After heating, the high-temperature molten salt or thermal oil can exchange heat with water to produce high-temperature and high-pressure steam, which in turn drives a steam turbine to generate work and generate electricity. It has a high heat storage capacity and is suitable for day and night load balancing. This example embodiment does not specifically limit the method for the renewable energy drive subsystem to achieve green electricity production.

[0029] The green electricity produced by the renewable energy drive subsystem 110 can be directly supplied to the power grid, or the electricity in excess or when the electricity price is too low can be stored in the CO2 energy storage module, or it can be directly supplied to the green hydrogen production system. The above three methods can adopt at least one or more combinations to generate different power supply strategies according to actual conditions. Those skilled in the art can customize the settings according to specific circumstances, and this embodiment is not limited to this.

[0030] The green electricity generated by the renewable energy drive subsystem 110 is connected to the water electrolysis hydrogen production equipment to generate green hydrogen and pure oxygen through the water electrolysis reaction. Without being limited to a specific model, the principle of the water electrolysis device can be based on an external voltage to drive the decomposition reaction of water molecules. The anode produces oxygen and the cathode produces hydrogen. The hydrogen is collected and then post-processed. To meet the requirements for hydrogen purity and pressure in industrial applications, the generated hydrogen undergoes gas-water separation, fine deoxygenation, compression and other processes to produce green hydrogen with a purity of not less than 99.999%. Green hydrogen is used as a raw material for the synthesis reaction and is sent to the multi-path utilization subsystem through the gas pipeline network and is transmitted in a gaseous state to maintain stable pressure. The pure oxygen generated during the electrolysis process is not discharged into the environment, but is used as a combustion aid for subsequent carbon source conversion and capture paths, effectively improving the overall energy utilization rate and CO2 enrichment efficiency of the system.

[0031] The carbon source conversion and capture subsystem 130 can receive raw materials from high-density agricultural and forestry biomass, such as cotton straw, sawdust, rice husks, nut shells, and forest understory branches and leaves. After pretreatment, these materials are fed into the biomass gasifier for pyrolysis and gasification. The gasifying agent in the gasification process is a mixture of water vapor and nitrogen. The water vapor is formed by the volatilization of moisture from the raw materials in a high-temperature environment. The nitrogen can be provided by an external air separation unit or recovered as by-gas from the green ammonia synthesis process. The gasifier reaction temperature can be controlled between 450°C and 550°C to maintain the production of effective gases such as H2, CO, and CO2. Some carbon is not fully reacted and converted into biochar or pyrolytic char. This biochar is separated and recycled as a material resource within the system. The main components of the gasification synthesis gas are H2, CO, CO2, and CH4. CH4 has a low volume fraction but a high calorific value, making it a useful auxiliary energy source in subsequent reactions.

[0032] The carbon source conversion and capture subsystem 130 may also include a CO2 capture path for separating and recovering the system's tail gas. For example, the CO2 from the green methanol reaction tail gas and the coal-fired power plant flue gas can be introduced into the capture module through independent pathways, and is often treated using an adsorption-desorption mechanism. For example, CaO is used as the adsorption medium, and CO2 concentration and enrichment are achieved through a combination of low-temperature adsorption and high-temperature calcination. CO2 from different sources is classified according to the properties of the carbon source. The CO2 from green methanol tail gas is renewable CO2, which is preferentially used for green methanol synthesis; the CO2 in coal-fired power plant flue gas is coal-based CO2, which can be used for conventional methanol reactions or compressed energy storage processing. The path of the carbon source conversion and capture subsystem achieves the maximum physical and chemical conversion and path control of the carbon source in the system through the principle of fractional utilization.

[0033] The multi-path utilization subsystem 120 receives green hydrogen from the renewable energy drive subsystem, gasification synthesis gas from the carbon source conversion and capture subsystem, and recovered CO2. The material ratios are then adjusted based on the desired product pathway, allowing the synthesis of green methanol, conventional methanol, or green ammonia. In the green methanol pathway, H2 and CO / CO2 are introduced into the reactor within a suitable molar ratio, where they are catalyzed by a copper-based catalyst to synthesize green methanol. The reaction pressure can be controlled within 5–10 MPa, and the temperature can be controlled within 200–300°C. Liquid methanol is recovered through condensation. The inclusion of renewable CO2 in the synthesis effectively improves the system's carbon conversion rate and reduces carbon intensity. The conventional methanol pathway uses coal-based CO2 and green hydrogen as feedstocks, and the reaction conditions are similar to those for green methanol. Its primary goal is to industrially utilize carbon resources from coal-based power sources. In the green ammonia pathway, green hydrogen and nitrogen from the air separation unit are fed into the synthesis loop at a ratio of approximately 3:1. Ammonia is synthesized over an Fe-based catalyst under high temperature and high pressure.

[0034] The heat generated in the multi-path reaction of the multi-path utilization subsystem 120 can be introduced into the gasification agent preheating section, the biomass raw material dehumidification section and the synthesis device insulation section through heat recovery, forming a cascade utilization of energy within the system; and the biomass charcoal is used as a material carrier to prepare a carbon-based denitrification catalyst. The carbon-based denitrification catalyst can be completed through processes such as impregnation with metal salt solution, activation treatment, drying and shaping, and finally reused for the removal of nitrogen oxides from flue gas in the system, thereby improving the flue gas treatment effect and forming a closed-loop utilization path for carbon-based materials.

[0035] The following is a detailed description of the polygeneration system 100 for wind-solar hydrogen production coupled with CO2 capture and utilization.

[0036] In an exemplary embodiment of the present disclosure, continue to refer to Figure 1 As shown, the renewable energy drive subsystem 110 may include a wind power generation module 111, a photovoltaic and solar thermal power generation module 112, and a green hydrogen production module 113; wherein: The wind power generation module 111 can be used to convert wind energy resources into electrical energy. For example, its basic structure may include rotor blades, a wind turbine tower, a generator, and a control frequency conversion unit. The rotor blades can adopt a horizontal or vertical axis structure. The blade design must determine the radius of curvature and pitch angle based on wind speed distribution, aerodynamic efficiency, and fatigue resistance. Composite materials are often used to achieve a balance between lightness and strength. The wind power generation module can use wind energy to drive the rotor to rotate. The low-speed shaft and high-speed shaft are driven by a coupling, which in turn drives a permanent magnet synchronous or doubly fed induction generator for energy conversion. The generated electrical energy is modulated by an inverter to a standard industrial frequency current output. To adapt to wind speed fluctuations, the module is equipped with an electronically controlled yaw system and a pitch adjustment mechanism to stabilize the output power. It also has an overspeed protection shutdown function to ensure safe operation of the system. Of course, the above is merely an illustrative example of the wind power generation module and should not impose any special limitations on this exemplary embodiment.

[0037] The photovoltaic and solar thermal power generation modules 112 can be used to convert solar radiation into photoelectric and thermal energy. The photovoltaic power generation portion can use a monocrystalline silicon or polycrystalline silicon photovoltaic module array to directly convert incident sunlight into direct current (DC) electricity, and achieve stable power output through a maximum power point tracking (MPPT) controller and inverter. The solar thermal power generation portion can include a trough collector or a tower heliostat array to focus solar radiation heat onto a heat collecting tube or a tower top heat absorber. Specifically, for example, the working fluid heated at the top of the solar thermal collector of a tower heliostat array is molten salt. The high-temperature molten salt is heated to form high-temperature molten salt, which then exchanges heat with water to generate high-temperature, high-pressure steam, which enters the steam turbine generator set. For another example, the working fluid heated by the trough collector is thermal oil. The heated thermal oil exchanges heat with water to generate high-temperature, high-pressure steam, which drives the steam turbine generator set to generate work and generate electricity. The two types of solar power generation paths can be connected in parallel to the system power supply bus. The output power is sent to the downstream power consumption unit or energy storage device through the junction box, transformer and energy storage interface to improve the responsiveness of the power generation system during periods of fluctuating sunlight.

[0038] The green hydrogen production module 113 is used to convert the green electricity generated by wind power generation modules and photovoltaic and solar thermal power generation modules into high-purity hydrogen that can be directly used in chemical synthesis processes. The core process of the green hydrogen production module can be water electrolysis, which uses external direct current to drive the decomposition of water molecules to produce hydrogen and oxygen. For example, the green hydrogen production module can use alkaline water electrolysis hydrogen production equipment, proton exchange membrane (PEM) water electrolysis hydrogen production equipment, or solid oxide water electrolysis hydrogen production equipment. Alkaline electrolysis is suitable for high-power stable operation scenarios, proton exchange membranes offer fast response speeds and high system integration, and solid oxides can utilize waste heat to synergistically produce hydrogen, making them suitable for high-temperature energy-abundant scenarios. During the electrolysis process, hydrogen is generated at the cathode and oxygen is generated at the anode. The produced gas passes through a gas-liquid separator to remove impurities and water vapor before entering the gas treatment unit.

[0039] The hydrogen output from the green hydrogen production module 113 can undergo deoxygenation, denitrification, and drying processes through one or more purification stages. Purification can be achieved through pressure swing adsorption (PSA), membrane separation, cryogenic fractionation, and other methods, ultimately achieving a high-purity green hydrogen volume fraction of ≥99.999%. The purified hydrogen can be compressed to medium or high pressure using a diaphragm, reciprocating, or scroll compressor to ensure stable delivery and reaction compatibility. The compressed green hydrogen is then delivered through the hydrogen supply network to a multi-path utilization subsystem for use in the green methanol, conventional methanol, and green ammonia synthesis reactions, providing continuous gas supply and dynamic allocation capabilities.

[0040] The oxygen produced during the electrolysis reaction can be recycled as a byproduct gas instead of being directly discharged. For example, it can be stored in a pressure-stabilizing buffer tank and then fed into the carbon source conversion and capture subsystem, where it serves as a pure oxygen combustion aid for the combustible components in the flue gas, replacing the traditional air-assisted combustion pathway. This not only improves combustion efficiency but also significantly increases the CO2 concentration in the flue gas, improving the adsorption efficiency of the subsequent CO2 capture process. Furthermore, it can reduce the concentration of nitrogen oxides in the flue gas. Through the internal oxygen reflux utilization mechanism, the deep coupling of the energy pathway and the gas pathway is effectively achieved, improving the resource utilization and economic adaptability of the overall system operation.

[0041] The renewable energy drive subsystem can convert wind and solar energy resources into electrical energy, and then further convert them into hydrogen and oxygen through the electrolysis process, thus realizing a closed loop of energy-quality conversion from natural energy to industrial raw materials. A power balance, gas mutual supply and by-product feedback mechanism are formed among the modules within the subsystem. Without relying on traditional fossil fuels, a highly stable, low-carbon emission and regionally friendly renewable energy empowerment path is constructed, providing a controllable, high-purity and efficient energy and raw material supply basis for the multi-path utilization subsystem.

[0042] Optional, continue to refer to Figure 1 As shown, the renewable energy drive subsystem 110 includes a CO 2 energy storage module 114 .

[0043] The CO2 energy storage module 114 uses the coal-based CO2 captured from the carbon source conversion and capture subsystem as the working fluid, and realizes energy storage and release through a compression-expansion cycle based on the thermodynamic compression energy storage principle and the physical state change characteristics of CO2. During operation, the coal-based CO2 can be compressed to above the critical pressure in the compressor. A multi-stage reciprocating compressor, a turbo compressor or a centrifugal compressor can be selected. The heat generated during the compression process can be recovered through an intercooler or a heat storage system for heat source compensation in other process links. In the compressed high-pressure CO2 state, the gas can be temporarily stored in a high-pressure storage tank, an underground shallow storage space or a liquid CO2 storage tank. The storage form can be flexibly selected according to the geological conditions and economic indicators of the deployment area. This embodiment does not impose any special restrictions on this.

[0044] When system power demand exceeds the actual renewable energy supply capacity, or when the green hydrogen production module's load is unstable, resulting in power redundancy, the CO2 energy storage module can release the stored high-pressure CO2 through an expander. While controlling the pressure reduction, it also performs mechanical work to drive a power generation device. For example, this can be achieved by CO2-driven micro-expanders and accompanying generator sets. This process enables flexible power release over short periods of time, compensating for power output instability in the wind, photovoltaic, and solar thermal power generation modules caused by natural fluctuations, thereby ensuring the stability of the input power required by the green hydrogen production module during operation.

[0045] The electricity required for the operation of the CO2 energy storage module 114 is entirely provided by the wind power generation module and the photovoltaic and solar thermal power generation modules in the renewable energy drive subsystem. This is dynamically scheduled via the DC bus or inverter control unit, and can be combined with the energy storage management system to achieve load forecasting and energy flow scheduling strategy optimization. The CO2 energy storage module and the green hydrogen production module are connected via a power transmission bus. When the green hydrogen production module is operating at full load, excess electricity can be preferentially transferred to the CO2 compression path for energy storage. When the green hydrogen production module is operating at reduced load due to electricity price fluctuations, grid scheduling, or internal maintenance, the CO2 energy storage module immediately initiates the CO2 release and power generation process to supplement the system power supply, achieving dynamic optimal allocation of power efficiency.

[0046] Furthermore, the coal-based CO2 used in the CO2 energy storage module 114 is a non-renewable carbon source, and its storage and recycling paths have a variety of configuration options. In some application scenarios, the compressed CO2 can be sold directly as commodity compressed gas, which has economic support in the deployment of parks with downstream CO2 raw material needs; in other scenarios, coal-based CO2 can also be introduced into the conventional methanol synthesis path and continue to participate in the downstream material synthesis reaction as a carbon source, forming a cross-coupling of energy storage and synthesis paths. In addition, in order to improve thermal efficiency and response speed, the CO2 energy storage module can be combined with a molten salt heat exchanger, a heat pump system or a phase change heat storage unit to form a multi-dimensional collaborative path between heat energy-electricity-materials, further enhancing the system's energy utilization efficiency and carbon resource sealing capabilities.

[0047] The CO2 energy storage module 114 can realize the important functions of regulating the electrical load fluctuation of the green hydrogen preparation module, recovering coal-based CO2 resources and participating in dynamic power scheduling. By compressing, storing and controllable releasing of coal-based CO2, a two-way interconnection between carbon resources and power paths is realized, thereby improving the stability of system operation and building a system-level energy storage mechanism with both energy regulation and carbon source utilization efficiency.

[0048] In an exemplary embodiment of the present disclosure, continue to refer to Figure 1 As shown, the multi-path utilization subsystem 120 may include a green methanol synthesis unit 121, a conventional methanol synthesis unit 122, and a green ammonia synthesis unit 123, wherein: The green methanol synthesis unit 121 receives high-purity green hydrogen from the renewable energy drive subsystem, gasified syngas from the carbon source conversion and capture subsystem, and renewable CO2. These gases are mixed and adjusted based on a controllable ratio to ensure that the syngas components meet the required molar ratios for methanol catalytic synthesis. For example, the reaction gas in the green methanol synthesis unit can generally be controlled within a molar ratio of H2:CO:CO2:N2 within the range of (62-70):(14-18):(10-15):(1-3), and a small amount of CH4 can be tolerated. After passing through the mixer, the reaction gas is heated to 180–250°C and compressed to 5–10 MPa. At these temperature and pressure conditions, it enters the methanol synthesis reactor. This reactor typically employs a shell-and-tube fixed-bed reactor structure, with a Cu / ZnO / Al2O3 catalyst system. A multi-channel arrangement ensures sufficient contact between the gas phase and the catalyst bed. The primary reaction during the reaction is CO2 hydrogenation to produce methanol and water, supplemented by CO hydrogenation to enhance the kinetic reaction rate. The reaction heat is recovered through an intermediate heat exchanger for preheating feed or providing heat for downstream systems. The resulting crude methanol gas is further purified through flash cooling, gas-liquid separation, and distillation dehydration before being collected as finished green methanol.

[0049] The conventional methanol synthesis device 122 can be used to process coal-based CO2 from the second CO2 capture unit in the CO2 capture device and high-purity hydrogen provided by the green hydrogen production module. In principle, this path is similar to the green methanol synthesis device, but the source of raw material CO2 is a non-renewable carbon source, i.e., carbon-based CO2, and the design condition is more focused on the improvement of carbon conversion rate and the enhancement of tail gas recycling capability. The hydrogen-to-carbon ratio in the synthesis gas can be moderately increased, and a tail gas compression and re-feeding circulation link is added to the reaction system to reduce carbon source waste. The catalyst used can be shared with the green methanol synthesis path, or a Fe-based or modified ZnCr-based catalyst system can be adapted according to the CO2 concentration to enhance the tolerance to the CO2 path. The product is recovered by condensation and sent to the methanol tower for purification, and the obtained conventional methanol can be used as energy fuel, chemical raw material or intermediate.

[0050] The green ammonia synthesis device 123 can be used to receive high-purity hydrogen and nitrogen supplied by the air separation device, adjust the gas according to the molar ratio of the ammonia synthesis reaction 2NH3=N2+3H2, compress the mixed gas to 10-25 MPa and preheat it to 350-450°C, and then enter the synthesis tower. The reactor body can adopt a multi-bed adiabatic type or a shell cooling type reactor, and the catalyst is a Fe3O4-based high-temperature ammonia synthesis catalyst, which is often supplemented with promoters such as K2O and Al2O3 to adjust the activity and thermal stability. To improve the reaction rate, several circulating compressors can be arranged in the reactor to continuously circulate unconverted gas, ensuring the improvement of single-pass conversion rate of ammonia gas. The reaction gas is treated by an ammonia condenser to realize the separation of liquid ammonia and unreacted gas, and the ammonia gas is collected as a product, and the tail gas is returned to the previous stage for recycling. This path constitutes a closed reaction channel between hydrogen and nitrogen, realizing high-density output of hydrogen energy in the form of fixed nitrogen products.

[0051] The green methanol synthesis device, the conventional methanol synthesis device and the green ammonia synthesis device not only realize the collaborative utilization of raw material paths, but also can be coupled in terms of heat energy management, gas supply, reaction tail gas disposal, etc. For example, the green methanol and conventional methanol devices can share hydrogen sources and heating equipment, the waste heat generated by the green ammonia device can be fed back to the previous gas compression section, and the unconverted gas in the tail gas of the three types of devices can be uniformly transported to the CO2 capture path after passing through the gas recovery system to reduce the carbon emission intensity. In addition, the medium and low temperature waste heat generated during the reaction can be coupled to the biomass gasification device or the air separation device to form a heat energy cascade utilization path, thereby improving the overall thermal efficiency of the system.

[0052] Through the division and cooperation of the green methanol synthesis device, the conventional methanol synthesis device and the green ammonia synthesis device, the multi-path utilization subsystem not only realizes the differentiated utilization of different carbon source attributes and hydrogen source resources, but also builds an integrated reaction network from green hydrogen to multiple carbon-hydrogen product outputs, while ensuring resource coupling and improving multi-product co-production capacity, thereby providing raw material support for various downstream application scenarios.

[0053] In an example embodiment of the present disclosure, continuing to refer to Figure 1 As shown, the carbon source conversion and capture subsystem 130 includes an air separation device 131, a flue gas treatment device 132, a CO2 capture device 133, and a biomass gasification device 134, wherein: The air separation device can be used to provide high-purity nitrogen and oxygen to support subsequent gasification reaction and combustion-supporting reaction processes. The air separation device can be based on cryogenic air separation technology, i.e., air is compressed and then pre-cooled, rectified, and multi-stage heat exchanged to achieve oxygen-nitrogen separation. In an alternative implementation, the air separation device can include a primary compressor, a pre-cooler, a rectification tower, a reheater, and an expander system, which utilizes the difference in boiling points of various components of air at low temperatures to perform separation operations. The separated nitrogen is a high-purity gas, usually with a purity of more than 99.99%, and in the system, part of the nitrogen is used to mix with water vapor to form N2-H2O gasification agent for feeding into the biomass gasification device, and part of the nitrogen is used as reaction gas for the green ammonia synthesis device. At the same time, oxygen can be extracted in proportion after separation to supply medical oxygen, and the remaining oxygen is stored in a tank and then supplied to the flue gas treatment device as pure oxygen combustion-supporting gas.

[0054] The flue gas treatment device can be used to condition and purify the flue gas generated in the green methanol synthesis reaction and the coal-fired combustion process, and its main functions include heat exchange and cooling, desulfurization, denitrification, and dust removal processes. In the treatment process, the first step is to recover heat from high-temperature flue gas through a heat exchanger, and the heat is sent to the air separation device through a heat transfer oil or water vapor circuit to heat the separated nitrogen to 160-180°C, while being used for preheating of biomass raw materials and temperature maintenance and heating of reactors in the multi-path utilization subsystem. Subsequently, the flue gas passes through a desulfurization tower, which uses a limestone-gypsum wet desulfurization process to generate CaSO4 precipitate, achieving efficient removal of SO2; after entering the denitrification unit, selective catalytic reduction (SCR) can be used to reduce nitrogen oxides to N2 and H2O under the action of carbon-based denitrification catalysts; finally, the flue gas enters a bag filter or electrostatic precipitator to remove dust, and the purified flue gas enters the CO2 capture device for carbon dioxide extraction.

[0055] The CO2 capture device can be coupled with the flue gas treatment device to complete the effective separation and reuse of CO2 in the exhaust gas. It can include two methods: chemical absorption and high-temperature solid-phase adsorption. For example, using CaO as an adsorbent, a gas-solid reaction CaO+CO2=CaCO3 is carried out, and the adsorption and desorption processes are cyclically carried out by controlling the reaction temperature and pressure. The captured CO2 can be divided into renewable CO2 and coal-based CO2 according to its source, and sent to the green methanol synthesis unit or the conventional methanol synthesis unit respectively. Part of the coal-based CO2 can also be supplied to the CO2 energy storage module or compressed and stored for subsequent industrial use or geological storage. This capture path not only achieves greenhouse gas emission control, but also can recover the high-value carbon resources in low-grade exhaust gas, enhance the carbon closed-loop capability of the system, and realize the full utilization of the carbon source in the system.

[0056] The biomass gasification unit can be the core reaction element of the carbon source conversion and capture subsystem. Its function is to convert solid biomass into gaseous syngas and produce reusable carbon-phase materials. The biomass gasification unit can be structured to include a gasifier, a feedstock inlet, a gasifying agent inlet, a gasified syngas outlet, and a biochar outlet. The feedstock used is agricultural and forestry biomass with a particle size of 0.5–10 mm and a moisture content of less than 15%. After crushing, drying, and screening, it is fed into the gasifier. The gasifying agent can be an N2-H2O mixture composed of nitrogen provided by an air separation unit and water vapor generated by volatilization of the preheated feedstock. This mixture is heated to 160–180°C after heat exchange in a flue gas treatment unit. It then enters the gasifier and is heated by contact convection with the biomass. The reaction temperature is maintained at 450–550°C. In a limited oxygen environment, dry distillation, thermal cracking, and partial oxidation reactions occur, producing a multi-component gasified syngas containing H2, CO, CO2, and CH4. A carbonized residue, namely biochar, is also produced as a by-product. It can be understood that during the heating of biomass, the moisture content of the biomass decreases, and water vapor H2O enters the biomass gasifier together with N2 as a gasifying agent. This method not only preheats the biomass raw materials, reduces the moisture content in the raw materials, and increases the feed temperature, but also introduces water vapor H2O as one of the gasifying agent components to form an N2-H2O mixed gas. During the gasification reaction, H2O+C=H2+CO, which can increase the concentration of H2 and CO in the gasification synthesis gas generated by the reaction, providing more hydrogen and carbon sources for the subsequent methanol preparation reaction.

[0057] The gasified syngas can be directly delivered to the multi-path utilization subsystem for green methanol synthesis. Biochar is discharged through the biochar outlet and then delivered to the biochar utilization module, forming a subsequent carbon-based material reuse pathway to support denitrification reactions and carbon sequestration within the system. The gasification unit can be equipped with an online temperature, pressure, and gas composition monitoring module. An automatic control unit adjusts the gasification agent flow rate and reaction temperature in real time to adapt to feedstock fluctuations, ensure stable syngas quality, and ensure the efficiency of downstream reaction pathways.

[0058] The carbon source conversion and capture subsystem formed by the above devices not only forms a closed-loop logic from biomass input to gas product output, from high-temperature flue gas treatment to low-temperature CO2 capture within the system, but also realizes cascade utilization, separate quality recovery and high-value conversion of carbon resources through multi-dimensional material and energy coupling between the renewable energy driving subsystem and the multi-path utilization subsystem, significantly improving carbon resource utilization efficiency and system operation economy.

[0059] Optionally, continuing to refer to Figure 1 As shown, the carbon source conversion and capture subsystem 130 can also include a biomass char utilization module 135, which can be used for deep processing and functional treatment of the biomass char produced in the biomass gasification device, thereby preparing a carbon-based denitration catalyst that can be reused in the flue gas denitration reaction, realizing high-value cyclic utilization of solid carbon residues, and enhancing the carbon resource closed-loop capability and pollutant co-control capability within the system. Specifically: The biomass char utilization module can receive the carbon phase byproduct from the biomass gasification device. The biomass char has high porosity and large specific surface area, and has good adsorption and loading performance, but the surface functional group distribution is uneven and the basic site activity is limited, which can be modified and activated through a series of chemical and heat treatment steps. The preliminary treatment stage can include physical screening, drying and deashing operations to remove large particle inorganic inclusions and control the particle size between 0.5-3 mm, ensuring the uniformity and stability of the subsequent loading process.

[0060] Subsequently, the catalyst carrier preparation stage can be entered, and a wet impregnation process can be used to load active metal components onto the surface of the carbon-based skeleton. For example, the loaded metal components can include V2O5, WO3, MnOx, Fe2O3, and other denitration active substances, which can be used alone or can form a bimetallic or composite metal oxide system to regulate the denitration temperature zone, improve the sulfur poisoning resistance and water stability. The metal salt precursor can be uniformly sprayed onto the surface of the carbon particles in the form of an aqueous solution, and the impregnation ratio and pH value are controlled to allow the metal ions to fully penetrate into the carbon pores, forming a good chemical adsorption or complex structure. The impregnated carbon particles are dried in a drying oven at a low temperature to remove free water, and then enter the calcination stage for activation.

[0061] The calcination step can control the heating rate, holding time and atmosphere conditions (generally air or inert atmosphere) to promote thermal decomposition of the metal salt precursor, generate stable oxide nanoparticles and uniformly distribute them on the surface of the carbon-based material, and further develop the microporous structure and oxidized surface functional groups of the carbon material. The finally prepared carbon-based denitration catalyst is black and gray in color, has stable structure and good catalytic activity, and the carbon-based catalyst can be further pressed or adjusted into a fixed bed, fluidized bed or honeycomb structure according to the use requirements, facilitating system engineering integration.

[0062] The heat required by the biochar utilization module can be derived from the waste heat of high-temperature exhaust from the flue gas treatment unit. By installing a heat exchanger and heat transfer medium pipeline, the hot flue gas discharged from the first or second flue gas treatment unit can provide heat support for the drying and calcination stages of the catalyst preparation process. This creates a closed loop of waste heat cascade recovery, carbon-based material conversion, and flue gas denitrification application. This not only improves thermal energy utilization efficiency but also avoids the high energy consumption of traditional carbon material activation processes.

[0063] The prepared carbon-based denitrification catalyst can be refluxed into the SCR module of the flue gas treatment device, serving as the core functional material of the reaction bed. For example, it can be placed inside the denitrification tower to interact with reducing gases (such as ammonia and urea pyrolysis products) to achieve the selective reduction of nitrogen oxide components in the flue gas to N2 and H2O. The reaction temperature can be controlled between 200 and 350°C and is suitable for environments with high CO2 concentrations and high water vapor, exhibiting excellent sulfur resistance and catalytic stability. The carbon-based catalyst generally has a service life of 8,000–10,000 hours. After deactivation, it can be regenerated or reprocessed for continued reuse, further improving material utilization and the environmental benefits of system operation. Even if it cannot be used as a denitrification catalyst after multiple regeneration and reuse, its main component is biochar, and the final calorific value of the carbon component can be extracted and utilized through combustion and other methods.

[0064] Through the biomass carbon utilization module, a complete process flow from carbon residue conversion, metal component loading, high-temperature calcination activation to catalyst directional preparation is established. Combined with the flue gas waste heat energy supply system, the clean, high-value and in-system recycling of solid by-products of gasification products is achieved, and an in-depth utilization path for pollution control and process intensification is constructed for the multiple carbon resources within the system.

[0065] In an exemplary embodiment of the present disclosure, the polygeneration system further includes a coal-fired power combustion module. Figure 1 As shown, the flue gas treatment device 132 may include a first flue gas treatment unit 1321 and a second flue gas treatment unit 1322, wherein: The coal-fired power combustion module can be used to introduce a coal-based carbon source into the system, and at the same time serve as an auxiliary heat energy supply unit, forming functional synergy with the waste heat utilization, CO2 capture and multi-path synthesis system in the system. The coal-fired power combustion module may include a raw coal supply system, a pulverizing system, a combustion chamber, an ash discharge system and a flue gas emission interface. The raw coal is crushed and screened before entering the coal mill to make pulverized coal, mixed with the primary air to form a coal powder airflow, and sent into the furnace through the burner for combustion. In order to cooperate with the pure oxygen combustion mechanism in the system, the coal-fired power combustion module can be equipped with an oxygen-enriched air inlet device or an external hot air recovery path to adjust the air excess coefficient in the furnace to ensure combustion sufficiency and reaction temperature stability. Under specific working conditions, the coal-fired power combustion module can also achieve variable load operation and participate in the dynamic scheduling of system energy. This example embodiment does not specifically limit the function of the coal-fired power combustion module in the polygeneration system.

[0066] The first flue gas treatment unit treats the combustible exhaust from the green methanol synthesis unit. This combustible exhaust typically contains a certain proportion of unreacted H₂, CO, a small amount of CH₄, and inert gases. To increase the CO₂ concentration in the flue gas and recover high-quality heat energy, the first flue gas treatment unit utilizes pure oxygen for combustion. This pure oxygen is provided as a byproduct of the green hydrogen production module and is regulated by a pressure stabilization buffer device before input. The burner achieves uniform mixing of the combustible gas and pure oxygen through multi-stage flame stabilization and nozzle agitation. The combustion temperature is controlled between 1200°C and 1600°C, ensuring a complete reaction while suppressing the formation of nitrogen oxides. The high-temperature flue gas after combustion passes through a high-efficiency heat exchanger to transfer heat to the outlet section of the air separation unit. The separated nitrogen is heated to 160-180°C before being supplied to the biomass gasification unit and some synthesis reaction units, achieving multi-stage recovery of flue gas waste heat. After heat exchange, the flue gas temperature is reduced to 150~180℃, and then it can pass through the wet desulfurization tower, honeycomb denitrification reactor and bag dust collector in sequence to achieve deep removal of SO2, nitrogen oxides and particulate matter, and realize desulfurization, denitrification, dust removal and other purification treatments of the flue gas after full combustion. After purification, the flue gas can enter the first CO2 capture unit for CO2 enrichment and capture.

[0067] The second flue gas treatment unit can be used to treat the flue gas discharged from the coal-fired power combustion module. The flue gas composition in this path is more complex. In addition to CO2, H2O and nitrogen oxides, it may also contain a large amount of fly ash, SO2 and heavy metal particles. Therefore, its treatment process design needs to take into account high flow, high corrosiveness and high capture efficiency. After the flue gas is heated in a high-temperature heat exchanger at the boiler outlet, it is introduced into the pre-dust collector for preliminary particulate matter filtration. It then enters the wet desulfurization tower and the selective catalytic reduction device in sequence. Lime slurry is added to the desulfurization liquid to neutralize SO2. The denitrification section uses a carbon-based denitrification catalyst to convert nitrogen oxides into N2, achieving desulfurization, denitrification, dust removal and other purification treatments for the fully burned flue gas. After the above purification process, the flue gas temperature and composition are adjusted to the parameter range suitable for CO2 capture, and it is sent to the second CO2 capture unit through the flue induced draft fan for deep CO2 recovery.

[0068] The first and second flue gas treatment units can share some auxiliary systems, such as the denitrified ammonia water delivery device, the desulfurization slurry circulation pump station, and the high-efficiency flue gas heat exchange network, to achieve energy optimization and reduce operating costs. The matching of the treatment capacity between the first and second flue gas treatment units can also be dynamically adjusted based on the operating status of the green methanol synthesis unit and the coal-fired power combustion module, thereby achieving real-time balancing of the flue gas load between the different carbon source paths within the system.

[0069] By organically integrating the coal-fired power combustion module and its supporting first flue gas treatment unit and the second flue gas treatment unit, a coordinated operation mechanism of coal-based carbon source introduction, efficient combustion of green tail gas and multi-path flue gas pollutant purification is realized, providing high-concentration, low-impurity background flue gas for the CO2 capture device, significantly improving the downstream CO2 capture efficiency, and at the same time ensuring the cascade transfer of thermal energy and waste heat utilization. It is a key subsystem that supports the operational stability of the entire polygeneration system and the full-process utilization capability of carbon resources.

[0070] In an exemplary embodiment of the present disclosure, continue to refer to Figure 1 As shown, the CO2 capture device 133 includes a first CO2 capture unit 1331 and a second CO2 capture unit 1332, wherein: The first CO2 capture unit treats the flue gas discharged from the first flue gas treatment unit. This flue gas primarily originates from the exhaust of the green methanol synthesis unit after pure oxygen combustion. Because nitrogen-containing air is not used as a combustion medium, this flue gas contains virtually no nitrogen, except for CO2 and H2O, and has low concentrations of impurities such as nitrogen oxides and SO2. To meet the capture requirements of flue gas with high CO2 concentrations, the first CO2 capture unit utilizes a circulating fluidized bed reaction system that combines gas-solid adsorption with high-temperature desorption. The adsorption medium utilizes highly active CaO particles, which react with CO2 to form CaCO3. The reaction occurs in the temperature range of 550-700°C. The adsorption reaction is exothermic, resulting in high gas-solid contact efficiency and stable CO2 conversion. The adsorbed CaCO3 is transported via a lifting device to a calcining tower, where it decomposes at 900-950°C, releasing high-purity CO2 gas. Simultaneously, the regenerated CaO flows back to the adsorption bed, achieving a closed-loop medium circulation.

[0071] After dehydration, dust removal, and buffering and pressure stabilization, the captured renewable CO2 is delivered to the green methanol synthesis unit, where it is combined with green hydrogen and gasification synthesis gas as a green carbon source for the reaction. To improve CO2 purity and system stability, the capture unit can be equipped with an online gas analyzer and automatic pressure regulator to ensure that the output gas volume fraction is maintained at above 99%. The system can also dynamically adjust the capture flux based on the methanol reaction load, thereby ensuring a consistent supply of raw material components.

[0072] The second CO2 capture unit can be connected to the second flue gas treatment unit. The flue gas to be treated comes from the coal-fired power combustion module. Its flue gas composition is complex, and the CO2 concentration is medium (usually between 12% and 18%), accompanied by SO2, nitrogen oxides and soluble dust residues. In order to meet the requirements of efficient separation of CO2 under low-concentration flue gas conditions, the second CO2 capture unit can adopt a liquid-phase chemical absorption process. For example, the absorbent system can include monoethanolamine (MEA) or a mixed amine solution. Its absorption tower is a countercurrent packed tower structure. The flue gas is introduced from the bottom of the tower, and the absorption liquid is sprayed from the top of the tower to form a gas-liquid countercurrent contact. It can be understood that the absorption reaction is CO2+2RNH2=RNH3 + +RNHCOO - , fast reaction rate and high absorption efficiency.

[0073] The rich liquid after absorption saturation is transported to the regeneration tower through a circulation pump, and the amine liquid undergoes CO2 removal reaction under the action of the heat energy provided by the reboiler, releasing CO2 and regenerated amine liquid. After condensation and dehumidification, the CO2 is converted into coal-based CO2 gas with a concentration of not less than 95%. Part of the gas is sent to a conventional methanol synthesis unit as a carbon source to participate in the reaction, and the rest is compressed and cooled and stored in a CO2 energy storage module, or further prepared as a compressed CO2 industrial product.

[0074] The first and second CO2 capture units are relatively independent in structure, but can operate collaboratively in process scheduling. The central control platform can be used to control the start and stop of the capture units and allocate their flux based on carbon source path requirements, reaction load fluctuations, and carbon sequestration strategies, thereby achieving dynamic matching of CO2 throughout the "source-capture-use" process. At the same time, the first and second CO2 capture units share some auxiliary systems, such as the CO2 buffer tank, drying and purification module, compressor unit, and analysis and detection system, thereby constructing a modular, scalable, and multi-path adaptable capture-transport-utilization integrated platform.

[0075] The CO2 capture device not only achieves precise capture and graded feeding of CO2 in different types of flue gas, but also enhances the flexible regulation capability of the polygeneration system for carbon emission control and carbon source organization, providing device-level technical support for building an efficient closed-loop carbon resource utilization system.

[0076] In an exemplary embodiment of the present disclosure, continue to refer to Figure 1 As shown, the multi-path utilization subsystem also includes a product storage module 140. The product storage module 140 can be connected to a green methanol synthesis unit, a conventional methanol synthesis unit, a green ammonia synthesis unit, a CO2 capture module, an air separation unit and a biomass charcoal utilization module to collect and store the produced green hydrogen, conventional methanol, green methanol, green ammonia, compressed CO2, pure oxygen, medical oxygen and carbon-based denitrification catalyst.

[0077] For the collection and storage of green hydrogen products, a gaseous high-pressure hydrogen storage tank or a metal hydride adsorption tank structure can be used. Hydrogen is provided by the green hydrogen preparation module, purified by pressure swing adsorption or membrane separation process, compressed to 15~70MPa by a multi-stage compressor, and stored in carbon fiber wrapped high-pressure gas cylinders or buried hydrogen storage containers. To achieve the continuity of hydrogen supply and the safety of system operation, the hydrogen collection and storage module can be equipped with a pressure balance system, a pressure relief valve group, a temperature-pressure interlock alarm and an inert gas replacement device. After storage, the hydrogen can be quantitatively fed into the green methanol, conventional methanol or green ammonia synthesis unit according to the hydrogen-carbon ratio adjustment results of the reactor, or it can be supplied externally as an industrial raw material or fuel on demand.

[0078] Conventional methanol and green methanol are liquid products, and their storage systems can include crude methanol buffer tanks, distillation methanol storage tanks, and discharge pump groups. After the two types of methanol are generated by the reaction, they are respectively removed of water and low-boiling impurities through flash condensation and distillation devices, and enter high-purity methanol storage tanks. The storage tanks are usually made of stainless steel or lined with anti-corrosion materials, and are equipped with liquid level gauges, breathing valves, and explosion-proof devices. In order to prevent the volatilization of methanol from affecting the environment and safety, a nitrogen sealing system can be installed on the top of the storage tank to maintain a positive pressure state in the tank. The storage tanks for green methanol and conventional methanol are arranged independently to prevent cross-contamination of products, and are equipped with branch pipelines connected to the external transmission module or on-site use unit.

[0079] To address ammonia's toxicity, corrosiveness, and high vapor pressure, green ammonia products can be stored in low-temperature liquid form. At the outlet of the synthesis tower, ammonia is cooled in a medium-pressure condenser and, after liquefaction, stored in ammonia storage tanks. Liquid ammonia storage tanks typically utilize vertical double-layer vacuum insulated tanks equipped with antifreeze and explosion protection, a temperature-controlled automatic cooling system, and an emergency sprinkler system. Green ammonia storage tanks can also be equipped with ammonia recovery and exhaust gas combustion systems to ensure system integrity and eliminate the risk of leakage. During storage, ammonia products can be used for fertilizer synthesis, hydrogen carrier output, or as a hydrogen feedstock for fuel cells, as needed.

[0080] Compressed CO2 products originate from coal-based CO2 gas captured and compressed by the secondary CO2 capture unit. During the compression process, the product undergoes staged cooling and water removal, ultimately compressed to a pressure of 6-15 MPa before entering liquid CO2 storage tanks. These storage tanks can be pressurized horizontal vessels equipped with dual valve redundancy, CO2 level monitoring, and an automatic pressure relief system. Parallel pumps are also used for external bottling or factory use. Some CO2 products can also be stored in a cryogenic freezer as solid dry ice for cryogenic transportation or industrial cooling applications.

[0081] Pure oxygen and medical oxygen can be produced as byproducts from air separation units and green hydrogen production modules. They must undergo water and dust removal prior to storage to ensure an oxygen purity exceeding 99.5%. Medical oxygen can also be purified through a medical-grade molecular sieve to remove trace organic impurities and odors. Oxygen can be stored in high-pressure cylinders, liquid oxygen tanks, or medium-pressure buffer tanks, zoned according to intended use. Medical oxygen storage tanks are equipped with independent exhaust paths and sanitary control interfaces that comply with Good Manufacturing Practice (GMP) requirements. Industrial-grade oxygen can be used in the system's pure oxygen combustion path, and medical oxygen can be provided to surrounding medical institutions or pharmaceutical companies, realizing the social resource utilization of energy byproduct gas.

[0082] As a solid product, the carbon-based denitrification catalyst's storage system can include a molding and cooling section, a classification and packaging section, and a catalyst storage depot. After preparation, the carbon-based denitrification catalyst is cooled to room temperature using a normal temperature air cooler. It then enters an automatic screening device for particle size classification. Qualified catalysts are quantitatively filled into ton bags or antioxidant containers by a packaging machine and stacked in the catalyst storage area according to batch numbers. The catalyst storage area must control temperature and humidity to prevent activity decay due to oxidation, deliquescence, or impurity adsorption. At the same time, a regeneration area is reserved for the recovery and treatment of deactivated catalysts, enabling multi-cycle closed-loop use of carbon-based materials.

[0083] The product storage and collection device enables status monitoring, output linkage, and emergency response, ensuring the stability of the system's operation under multi-product co-production conditions and the efficient coordination of various product channels, effectively supporting the output-end management and external docking capabilities of the multi-product co-production system.

[0084] refer to Figure 2 As shown, Figure 2 Provides a Figure 1 Schematic diagram of the energy flow path and material flow path in the polygeneration system of wind-solar hydrogen production coupled with CO2 capture and utilization. Figure 2 The continuous conversion, capture and feedback paths of H2, CO2 and biochar among various modules and units form a closed-loop cycle of carbon resources. The input carbon sources are converted into green methanol, conventional methanol or carbon-based denitrification catalyst to achieve the full utilization of carbon sources and the multi-generation goal of near-zero emissions.

[0085] It should be noted that while the detailed description above mentions several modules or subassemblies of a polygeneration system combining wind and solar power with CO2 capture and utilization, this division is not mandatory. In fact, according to embodiments of the present disclosure, the features and functions of two or more modules or subassemblies described above may be embodied in a single module or subassemblies. Conversely, the features and functions of a single module or subassemblies described above may be further divided and embodied by multiple modules or subassemblies.

[0086] In addition, the embodiment of the present disclosure also provides a wind-solar hydrogen production coupled with CO2 capture and utilization polygeneration method, which can be used in a wind-solar hydrogen production coupled with CO2 capture and utilization polygeneration system, refer to Figure 3 Specifically, it may include: Step S310: The renewable energy drive subsystem is used to generate green electricity. Dynamic adjustments are made based on the load demand of the green hydrogen production module, the time-of-use electricity price, the power required by the CO2 energy storage module, and the relationship between the power produced. This allows for adaptation between new energy generation, green electricity access, power storage, and green hydrogen production power consumption and economic efficiency. Step S320: Using the green hydrogen production module to produce green hydrogen and pure oxygen through a water electrolysis process, and separating, purifying, and pressurizing the green hydrogen to produce high-purity hydrogen. At the same time, according to the quality requirements of the conventional methanol synthesis unit and the green ammonia synthesis unit for H2, the hydrogen is pre-treated and then delivered to the conventional methanol synthesis unit and the green ammonia synthesis unit; Step S330: Using crushed and preheated agricultural and forestry biomass as raw material and a N2-H2O mixed gas as a gasifying agent, gasification is carried out at 450-550°C to generate gasification synthesis gas and biochar, and the gasification synthesis gas is fed into a green methanol synthesis unit, and the biochar is fed into a biochar utilization module to prepare a carbon-based denitrification catalyst; Step S340, using the green hydrogen produced by the green hydrogen production module, the gasification synthesis gas produced by the biomass gasification device, and the renewable CO2 recovered by the first CO2 capture unit as inputs to the green methanol synthesis device, and adjusting the volume ratio of H2, CO, and CO2 in the green methanol synthesis device to catalytically synthesize green methanol; Step S350: Input the prepared carbon-based denitration catalyst into the first flue gas treatment unit and the second flue gas treatment unit to remove nitrogen oxides, thereby achieving standard-compliant nitrogen oxide emissions in the flue gas. The heat generated by heat exchange and cooling during flue gas treatment in the first flue gas treatment unit is used to heat the N2 separated from the air separation unit, as well as for heating, insulation, and / or preheating in the production processes of the green hydrogen production module, the conventional methanol synthesis unit, and the green ammonia synthesis unit. In step S360, pure oxygen, a byproduct of the green hydrogen production module, is fed into the first flue gas treatment unit as a combustion aid to ensure that the first flue gas treatment unit fully burns the combustible gas discharged from the green methanol synthesis unit in a pure oxygen environment without introducing air as a gasifying agent. Part of the remaining pure oxygen is fed into the coal-fired power generation combustion module to supplement the air combustion aid in the coal-fired power generation combustion module. Step S370: feeding the renewable CO2 captured by the first CO2 capture unit into a green methanol synthesis unit, and feeding the coal-based CO2 in the coal-fired power plant flue gas captured by the second CO2 capture unit into a conventional methanol synthesis unit; Step S380: The produced green hydrogen, conventional methanol, green methanol, green ammonia, compressed CO2, pure oxygen, medical oxygen and carbon-based denitrification catalyst are collected and stored through the product storage module.

[0087] It should be noted that although the steps of the method disclosed herein are depicted in a particular order in the accompanying drawings, this does not require or imply that the steps must be performed in that particular order, or that all steps must be performed to achieve the desired result. Additionally or alternatively, certain steps may be omitted, multiple steps may be combined into one, and / or one step may be decomposed into multiple steps.

[0088] The specific details of each module in the above-mentioned wind-solar-hydrogen production coupled with CO2 capture and utilization polygeneration method have been described in detail in the corresponding wind-solar-hydrogen production coupled with CO2 capture and utilization polygeneration system, so they will not be repeated here.

Claims

1. A wind-solar hydrogen production coupled with CO2 capture and utilization polygeneration system, characterized by: include: The renewable energy drive subsystem is used to provide green electricity generated by wind power generation, photovoltaic power generation, and solar thermal power generation, and to produce green hydrogen by water electrolysis. The green hydrogen is supplied to the multi-path utilization subsystem as an energy carrier and synthetic raw material; A carbon source conversion and capture subsystem is used to receive biomass feedstock and generate gasification synthesis gas containing H2, CO, CO2, and CH4 through a gasification reaction, while also producing biomass char; the carbon source conversion and capture subsystem is also used to capture CO2 from green methanol tail gas combustion flue gas and coal-fired power flue gas, and respectively feed the captured renewable CO2 and coal-based CO2 into the multi-path utilization subsystem or the renewable energy drive subsystem; a multi-path utilization subsystem for receiving H2, the gasification synthesis gas, and CO2, adjusting reaction components to achieve the synthesis of green methanol, conventional methanol, and green ammonia, and utilizing the biochar to process and prepare a carbon-based denitrification catalyst for internal flue gas purification in the system, and forming a closed-loop thermal energy and reaction coupling channel between the multi-path utilization subsystem and the renewable energy drive subsystem through the supply of electricity and pure oxygen; Among them, the continuous conversion, capture and feedback paths of H2, CO2 and biochar between each subsystem form a closed-loop cycle of carbon resources. The input carbon sources are converted into green methanol, conventional methanol or carbon-based denitrification catalyst to achieve the full utilization of carbon sources and the multi-generation goal of near-zero emissions.

2. The polygeneration system according to claim 1, characterized in that: The renewable energy drive subsystem includes a wind power generation module, a photovoltaic and solar thermal power generation module, and a green hydrogen production module; The wind power generation module and the photovoltaic and solar thermal power generation modules are used to produce green electricity; The green hydrogen production module includes one or more combinations of an alkaline water electrolysis hydrogen production device, a proton exchange membrane water electrolysis hydrogen production device or a solid oxide water electrolysis hydrogen production device, which is used to generate green hydrogen through the green electricity, supply the green hydrogen to the multi-path utilization subsystem, and supply the by-product pure oxygen to the carbon source conversion and capture subsystem as a combustion-supporting gas.

3. The polygeneration system according to claim 2, characterized in that: The renewable energy drive subsystem includes a CO2 energy storage module, which is used to use the coal-based CO2 recovered and captured by the carbon source conversion and capture subsystem as a working fluid, and realize energy storage and release through a compression-expansion cycle. The required electrical energy is provided by the wind power generation module and the photovoltaic and solar thermal power generation module, and is used to adjust the load fluctuation of the green hydrogen preparation module.

4. The polygeneration system according to claim 1, characterized in that: The multipath utilization subsystem includes: A green methanol synthesis device is used to receive green hydrogen, gasification synthesis gas and renewable CO2 provided by the carbon source conversion and capture subsystem, adjust the components for catalytic synthesis, and obtain green methanol; Conventional methanol synthesis unit, used to receive coal-based CO2 and green hydrogen to synthesize conventional methanol; The green ammonia synthesis unit is used to receive green hydrogen and react it with N2 from the air separation system to synthesize ammonia to obtain green ammonia.

5. The polygeneration system according to claim 1, characterized in that: The carbon source conversion and capture subsystem includes: An air separation unit, which is used to produce nitrogen and medical oxygen, wherein nitrogen is used as a gasifying agent in a green ammonia production module and a biomass gasification unit; Flue gas treatment device, used to purify the flue gas discharged from the system after heat utilization; A CO2 capture device, connected to the flue gas treatment device, is used to capture CO2 in the flue gas after purification and to supply the renewable CO2 therein to the green methanol synthesis device, the conventional methanol device or the CO2 energy storage module; A biomass gasification device includes a biomass gasification furnace, a raw material inlet, a gasifying agent inlet, a gasification synthesis gas outlet and a biomass charcoal outlet. The biomass gasification device uses agricultural and forestry biomass as raw material and N2 produced from an air separation unit and heated and preheated by the flue gas treatment device to form an N2-H2O mixed gas as a gasifying agent. A gasification reaction occurs at 450-550°C to generate gasification synthesis gas and biomass charcoal. The gasification synthesis gas is used for green methanol synthesis, and the biomass charcoal is used to prepare a carbon-based denitrification catalyst.

6. The polygeneration system according to claim 5, characterized in that: The carbon source conversion and capture subsystem also includes a biomass charcoal utilization module; The biochar utilization module is used to prepare a carbon-based denitration catalyst by using the biochar as a carrier through impregnation and loading of denitration active components. The carbon-based denitration catalyst is reused in the SCR denitration process in the flue gas treatment device. The heat energy required in the preparation process of the carbon-based denitration catalyst is obtained by waste heat exchange from the flue gas treatment device.

7. The polygeneration system according to claim 5, characterized in that: The polygeneration system further includes a coal-fired power combustion module, and the flue gas treatment device includes: The first flue gas treatment unit is used to use the pure oxygen output by the green hydrogen production module as a combustion aid to burn the combustible gas discharged from the green methanol synthesis unit to enrich the CO2 in the flue gas and recover heat energy. The flue gas after sufficient combustion is then desulfurized, denitrified, and dusted. The second flue gas treatment unit is used to perform desulfurization, denitrification and dust removal purification treatment on the flue gas discharged from the coal-fired power combustion module and after heat utilization.

8. The polygeneration system according to claim 7, characterized in that: The CO2 capture device comprises: a first CO2 capture unit connected to the first flue gas treatment unit, configured to use the flue gas discharged from the first flue gas treatment module as a raw material and CaO as a medium, to obtain renewable CO2 through adsorption, calcination, and collection, and to deliver the captured renewable CO2 to the green methanol synthesis unit as a green carbon source to supplement the carbon elements required for the reaction; The second CO2 capture unit is connected to the second flue gas treatment unit, and is used to use the flue gas discharged from the second flue gas treatment module as raw material and CaO as the medium to obtain coal-based CO2 after adsorption, calcination and collection, and to transport the captured coal-based CO2 to a conventional methanol synthesis unit, a CO2 energy storage module and the preparation of compressed CO2 products.

9. The polygeneration system according to claim 1, characterized in that: The polygeneration system also includes a product collection and storage module, which is connected to the green methanol synthesis unit, the conventional methanol synthesis unit, the green ammonia synthesis unit, the CO2 capture module, the air separation unit and the biomass charcoal utilization module, and is used to collect and store the produced green hydrogen, conventional methanol, green methanol, green ammonia, compressed CO2, pure oxygen, medical oxygen and carbon-based denitrification catalyst.

10. A polygeneration method for wind and solar hydrogen production coupled with CO2 capture and utilization, characterized in that: The method for the polygeneration system for wind-solar hydrogen production coupled with CO2 capture and utilization according to any one of claims 1 to 9 comprises: The renewable energy drive subsystem enables the production of green electricity. Dynamic adjustments are made based on the load demand of the green hydrogen production module, the time-of-use electricity price, the power required by the CO2 energy storage module, and the relationship between the power produced. This allows for the adaptation of new energy generation, green electricity access, power storage, and green hydrogen production power consumption and economic efficiency. The green hydrogen production module produces green hydrogen and pure oxygen through a water electrolysis process, and the green hydrogen is separated, purified, and pressurized to produce high-purity hydrogen. At the same time, according to the quality requirements of conventional methanol synthesis units and green ammonia synthesis units, the hydrogen is pre-treated and sent to the conventional methanol synthesis unit and the green ammonia synthesis unit; The biomass gasification device uses crushed and preheated agricultural and forestry biomass as raw materials and N2-H2O mixed gas as gasifying agent to gasify at 450-550°C to generate gasification synthesis gas and biochar, and the gasification synthesis gas is fed into the green methanol synthesis device, and the biochar is fed into the biochar utilization module to prepare a carbon-based denitrification catalyst; The green hydrogen produced by the green hydrogen production module, the gasification synthesis gas produced by the biomass gasification unit, and the renewable CO2 recovered by the first CO2 capture unit are used as inputs to the green methanol synthesis unit, and the volume ratio of H2, CO and CO2 in the green methanol synthesis unit is adjusted to catalytically synthesize green methanol; The prepared carbon-based denitrification catalyst is input into the first flue gas treatment unit and the second flue gas treatment unit to remove nitrogen oxides, thereby achieving standard emission of nitrogen oxides in the flue gas. The heat displaced by heat exchange and cooling during flue gas treatment in the first flue gas treatment unit is used to heat the N2 separated from the air separation unit, and is used for heating, insulation and / or preheating in the production processes of the green hydrogen production module, the conventional methanol synthesis unit and the green ammonia synthesis unit; The pure oxygen produced as a by-product of the green hydrogen production module is fed into the first flue gas treatment unit as a combustion aid to ensure that the combustible gas discharged from the green methanol synthesis unit is fully burned in a pure oxygen environment in the first flue gas treatment unit without introducing air as a gasifying agent. Part of the remaining pure oxygen is fed into the coal-fired power generation combustion module as a supplement to the air combustion aid in the coal-fired power generation combustion module; The renewable CO2 captured by the first CO2 capture unit is fed into a green methanol synthesis unit, and the coal-based CO2 captured in the coal-fired power plant flue gas by the second CO2 capture unit is fed into a conventional methanol synthesis unit; The product storage module collects and stores produced green hydrogen, conventional methanol, green methanol, green ammonia, compressed CO2, pure oxygen, medical oxygen and carbon-based denitrification catalysts.

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