Method for co-production of green iron and green energy by reducing iron oxides with biomass instead of green hydrogen

Abstract

The application discloses a method for co-producing green iron and green energy by reducing iron oxide with biomass instead of green hydrogen, which comprises the following steps: step one, drying and crushing biomass raw materials to a water content of less than or equal to 8% and a particle size of 10-20 mm, wherein the biomass raw materials are any one or more of sawdust, straw, bamboo chips, fruit shells and agricultural and forestry processing waste; adding a binder to iron oxide powder to form balls with a particle size of phi 10-20 mm and drying the balls, wherein the iron oxide is at least one of iron ore (Fe2O3, Fe3O4), ilmenite and red mud, and the TFe content is 35-68%; and mixing the biomass raw materials and the iron oxide balls at a mass ratio of 1-2:1, wherein the method for co-producing green iron and green energy by reducing iron oxide with biomass instead of green hydrogen has strong technical exclusivity: there is no direct competitor in the world for the core process of replacing green hydrogen to reduce iron ore by 100% of biomass, and multiple technical barriers are formed by the vertical furnace external heating segmented integrated design and the polygeneration system, so that the related market can be monopolized within the patent protection period.

Description

Technical Field

[0001] This invention relates to the fields of low-carbon metallurgy, biomass polygeneration, green electrochemicals, and carbon resource utilization, specifically a method for producing green iron cogeneration green energy by replacing green hydrogen with biomass. Background Technology

[0002] The existing biomass utilization, green hydrogen reduction of iron oxides to produce green iron, and green methanol production industries have significant technological shortcomings: 1. Conventional biomass gasification uses a gasifier with air separation unit to produce oxygen at high temperatures. High-value-added methane and bio-oil are re-decomposed into hydrogen, carbon monoxide, and carbon dioxide at these high temperatures, resulting in a waste of economic value, and also incurring high investment and energy consumption; 2. Traditional biomass gasification synthesis gas has an unbalanced hydrogen-to-carbon ratio. Simply relying on the raw materials themselves to produce gas cannot stably achieve the 2.0:1 stoichiometric ratio for methanol synthesis. It is necessary to add steam and, under the action of a catalyst, reduce the hydrogen monoxide to form green iron. 1. Carbon dioxide is converted into hydrogen and carbon dioxide, resulting in a waste of energy and green carbon resources; 2. Existing green methanol production processes generally adopt a high-temperature gasification route of biomass + air separation to produce oxygen. After conversion, decarbonization, methanol synthesis and other steps, there are problems such as high energy consumption, large investment, high cost and unstable operation; 3. Existing technologies are all single products or dual products co-produced, which have defects such as weak market risk resistance, low resource utilization rate and long investment return cycle. Moreover, they cannot simultaneously solve the three major industry pain points of iron ore import dependence, biomass resource utilization and carbon emission control. Summary of the Invention

[0003] The technical problem to be solved by this invention is to overcome the existing defects and provide a method for producing green iron and co-producing green energy by replacing green hydrogen with biomass. The method uses biomass to replace 100% of green hydrogen as the reducing medium and achieves the coupling of biomass pyrolysis and biomass carbon reduction of iron oxide through a vertical furnace external heating segmented integrated process, co-producing green iron, green electricity, green hydrogen, green methanol, green ammonia, and green fuel gas, which can effectively solve the problems in the background technology.

[0004] To achieve the above objectives, the present invention provides the following technical solution: A method for producing green energy by reducing iron oxide with green hydrogen using biomass as an alternative to green hydrogen includes the following steps: Step 1: Dry and crush the biomass raw materials to a moisture content ≤8% and a particle size of 10-20mm. The biomass raw materials are any one or more of sawdust, straw, bamboo shavings, fruit shells, and agricultural and forestry processing waste. Add a binder to the iron oxide powder to form pellets with a particle size of φ10-20mm and dry them. The iron oxide is at least one of iron ore (Fe2O3, Fe3O4), ilmenite, and red mud, with a TFe content of 35-68%. Step 2: Mix biomass raw materials and iron oxide balls at a mass ratio of 1 to 2:1 and feed them into an externally heated vertical shaft furnace. Maintain a slight positive pressure (5-500 Pa) inside the furnace and isolate oxygen. Use a segmented heating integrated process: control the temperature of the upper section at 550-800℃ to achieve biomass pyrolysis and gas production, and control the temperature of the lower section at 800-1200℃ to achieve carbothermic reduction of iron ore. The total residence time of the material is 6-14 hours. The externally heated vertical shaft furnace does not have an air separation oxygen production device. Carbon and volatiles generated by biomass pyrolysis replace green hydrogen as the reducing medium. Green syngas containing H2, CO, and CH4 is produced at the top of the furnace, and coarse sponge iron with a metallization rate of ≥93% is generated at the bottom of the furnace. Step 3: After the green syngas from Step 2 is subjected to dust removal, cooling to remove bio-oil and wood vinegar, and drying and dehydration, it is sent to a pressure swing adsorption (PSA) device to remove carbon dioxide and separate and purify to obtain green fuel gas with a purity of ≥98%. The green fuel gas is exported as an independent finished product. Step 4: Use wind power or photovoltaic green electricity to drive an electrolyzer to electrolyze industrial pure water to prepare high-purity green hydrogen with a purity of ≥99.99%. The high-purity green hydrogen is then introduced into the decarbonized syngas in step 3) at a preset ratio. The hydrogen-to-carbon ratio (H2 / CO) of the syngas is controlled online and strictly locked at 1.9 to 2.1:1.

[0005] Step 5: The syngas after step 4 is subjected to dry desulfurization (sulfur content after desulfurization <0.1ppm) and sent to a low-pressure methanol synthesis tower to synthesize crude methanol under the conditions of pressure 4.0~8.0MPa and temperature 200~260℃. After distillation, green methanol with a purity ≥99.9% is obtained. Step 6: The crude sponge iron produced in Step 2 is directly fed into the green electric arc furnace and heated to 1550-1650℃ using wind power and photovoltaic green electricity. After melting, slag-iron separation, refining and purification, green iron with a purity of ≥95% is obtained. The smelting slag is used for building material preparation. The bio-oil and wood vinegar produced as byproducts of Step 7 and Step 3, as well as the smelting slag from Step 6, are all recycled as resources, with no solid waste, hazardous waste, or waste gas discharged throughout the entire process.

[0006] Preferably, the biomass is any one or more of wood chips, straw, bamboo chips, fruit shells, and agricultural and forestry processing waste.

[0007] Preferably, the iron oxide is iron ore (Fe2O3, Fe3O4), ilmenite, red mud, or iron-containing waste slag from the smelting industry, with a TFe content of 35-68%.

[0008] Preferably, the externally heated vertical furnace adopts segmented temperature control, with the upper section at 550-800℃ and the lower section at 800-1200℃.

[0009] Preferably, the biomass replaces green hydrogen as the sole reducing medium, without the addition of green hydrogen, fossil hydrogen or other reducing gases, and the energy consumption of the reduction process is reduced by more than 40% compared with the green hydrogen reduction of iron ore process.

[0010] Preferably, in the segmented heating integrated process of the externally heated vertical furnace, the methane and volatiles produced by the upper stage biomass pyrolysis and the CO produced by the lower stage carbothermic reduction together constitute green syngas.

[0011] Preferably, in the cogeneration process, the production ratio of green iron, green fuel, green electricity, green hydrogen, green methanol, and green ammonia can be adjusted according to market demand, and all products meet the requirements for negative carbon certification and CCER carbon asset declaration.

[0012] Preferably, in step two, the iron oxide can be selected from low-grade iron ore with TFe content of 30-60%, which can be directly used for the reduction reaction without the need for mineral processing and enrichment.

[0013] Compared with the prior art, the beneficial effects of the present invention are: 1. Strong technological exclusivity: The core process of 100% biomass substitution for green hydrogen reduction of iron ore has no direct competitors in the world. The integrated design of the vertical shaft furnace external heating section and the multi-generation system form multiple technological barriers, and the patent protection period can monopolize the relevant market. 2. Significant economic value: A single unit can produce 100,000 tons of green methanol, co-produce 140,000 tons of green iron and 19 million standard cubic meters of green methane, with a net profit margin of 20-30%, which is 50% higher than the return on investment of a single green methanol project, and the investment payback period is shortened to 4 years; all three types of products have clear premium potential. 3. Investment cost advantage: No gasifier or air separation oxygen production unit is required. The integrated device couples biomass syngas production with carbon reduction of iron ore, reducing equipment investment by 20-30% compared to similar projects; it can utilize low-grade iron ore and agricultural and forestry waste, resulting in significantly lower raw material costs than traditional processes. 4. High level of industrialization maturity: The core process has been verified through small-scale trials, and the key parameters are stable (iron ore metallization rate ≥93%, energy consumption ≤60% of industry average); except for the externally heated pyrolysis-reduction integrated furnace, other equipment are all industrial standard equipment (PSA unit, green electric arc furnace, etc.), with no customized high-risk equipment, and the success rate of pilot-scale amplification is ≥95%; 5. Good policy adaptability: It aligns with national strategies and can be used to apply for multiple policy supports such as CCER carbon assets, green technology demonstration projects, and biomass utilization subsidies; 6. Highly disruptive to the industry: It can disrupt the existing long-process ironmaking technology, solve the carbon emission problem in the steel industry; alleviate the predicament of heavy reliance on imported iron ore; promote the industrialization of biomass resource utilization, and drive rural employment; 7. Outstanding risk resistance: The multi-product model covers the green steel and green energy sectors with high demand. When the market for a single product fluctuates, the risk can be offset by the income from other products. Resource recycling increases income from by-products, further enhancing the project's profitability stability. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the process flow of the present invention. Detailed Implementation

[0015] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0016] Please see Figure 1 The present invention provides a technical solution: A method for producing green energy by reducing iron oxide with green hydrogen using biomass as an alternative to green hydrogen includes the following steps: Step 1: Dry and crush the biomass raw materials to a moisture content ≤8% and a particle size of 10-20mm. The biomass raw materials can be any one or more of sawdust, straw, bamboo shavings, nutshells, and agricultural and forestry processing waste. Add a binder to the iron oxide powder to form pellets with a particle size of φ10-20mm and dry them. The iron oxide can be at least one of iron ore (Fe2O3, Fe3O4), ilmenite, and red mud, with a TFe content of 35-68%. Step 2: Mix biomass raw materials and iron oxide balls at a mass ratio of 1 to 2:1 and feed them into an externally heated vertical shaft furnace. Maintain a slight positive pressure (5-500 Pa) inside the furnace and isolate oxygen. Use a segmented heating integrated process: control the temperature of the upper section at 550-800℃ to achieve biomass pyrolysis and gas production, and control the temperature of the lower section at 800-1200℃ to achieve carbothermic reduction of iron ore. The total residence time of the material is 6-14 hours. The externally heated vertical shaft furnace does not have an air separation oxygen production device. The carbon and volatiles generated by biomass pyrolysis replace green hydrogen as the reducing medium. Green syngas containing H2, CO, and CH4 is produced at the top of the furnace, and coarse sponge iron with a metallization rate of ≥93% is generated at the bottom of the furnace. Step 3: After the green syngas from Step 2 is subjected to dust removal, cooling to remove bio-oil and wood vinegar, and drying and dehydration, it is sent to a pressure swing adsorption (PSA) unit to remove carbon dioxide and separate and purify to obtain green gas with a purity of ≥98%. The green gas is exported as an independent finished product. Step 4: Use wind power or photovoltaic green electricity to drive an alkaline electrolyzer to electrolyze industrial pure water to prepare high-purity green hydrogen with a purity of ≥99.99%. Pass the high-purity green hydrogen into the decarbonized syngas in step 3) according to a preset ratio, and control and strictly lock the hydrogen-carbon ratio of syngas (H2 / CO) to 1.9-2.1:1 online.

[0017] Step 5: The syngas after step 4 is subjected to dry desulfurization (sulfur content after desulfurization <0.1ppm) and sent to a low-pressure methanol synthesis tower to synthesize crude methanol under the conditions of pressure 4.0~8.0MPa and temperature 200~260℃. After distillation, green methanol with a purity ≥99.9% is obtained. Step 6: The crude sponge iron produced in Step 2 is directly fed into the green electric arc furnace and heated to 1550-1650℃ using wind power and photovoltaic green electricity. After melting, slag-iron separation, refining and purification, green iron with a purity of ≥95% is obtained. The smelting slag is used for building material preparation. The bio-oil and wood vinegar produced as byproducts of Step 7 and Step 3, as well as the smelting slag from Step 6, are all recycled as resources, with no solid waste, hazardous waste, or waste gas discharged throughout the entire process.

[0018] Biomass can be any one or more of the following: wood chips, straw, bamboo chips, fruit shells, and agricultural and forestry processing waste.

[0019] Iron oxides are found in iron ore (Fe2O3, Fe3O4), ilmenite, red mud, and iron-containing waste slag from the smelting industry, with a TFe content of 35-68%.

[0020] The externally heated vertical furnace adopts segmented temperature control, with the upper section at 550-800℃ and the lower section at 800-1200℃.

[0021] Biomass replaces green hydrogen as the sole reducing medium, without the need for additional green hydrogen, fossil hydrogen, or other reducing gases. The energy consumption of the reduction process is reduced by more than 40% compared to the green hydrogen reduction process for iron ore.

[0022] In the segmented heating integrated process of the externally heated vertical furnace, the hydrogen, methane, carbon monoxide, and carbon dioxide produced by the upper stage biomass pyrolysis, together with the carbon monoxide and carbon dioxide produced by the lower stage carbothermal reduction, constitute green syngas.

[0023] In the cogeneration process, the production ratio of green iron, green fuel, green electricity, green hydrogen, green methanol, and green ammonia can be adjusted according to market demand, and all products meet the requirements for negative carbon certification and CCER carbon asset declaration.

[0024] In step two, low-grade iron ore with 30-60% TFe can be used for iron oxides, which can be directly used for the reduction reaction without the need for mineral processing and enrichment.

[0025] Biomass 100% replaces green hydrogen as the sole medium for iron ore reduction, without the addition of green hydrogen, fossil hydrogen or other reducing gases. Compared with the traditional green hydrogen to green iron process, the overall investment is reduced by 40% and energy consumption is reduced by more than 40%, completely solving the industry bottleneck of high green hydrogen reduction cost. The first vertical furnace features an integrated external heating section design, where the upper biomass pyrolysis and the lower carbothermic reduction are completed in the same equipment, eliminating the need for separate pyrolysis and reduction furnaces. This reduces equipment investment by 30%, and the pyrolysis gas directly participates in the reduction reaction, increasing energy utilization to over 75%. The world's first bio-based reduction of iron oxide to produce green iron co-generation green energy (which can produce green gas, green electricity, green hydrogen, green alcohol, and green ammonia); It can directly use low-grade iron ore with TFe content of 30-60% and agricultural and forestry waste, without the need for mineral processing and enrichment. The raw material cost is reduced by 15-20% compared with traditional processes, which can alleviate my country's dependence on iron ore imports. The entire process is free of fossil energy. The electrolysis and smelting stages are driven by wind power and photovoltaic green electricity. Both green iron and green energy products can independently apply for negative carbon certification and CCER carbon assets. The annual CO2 emission reduction can reach 15,000 tons / 10,000 tons of green iron. The by-products of the process, such as bio-oil, biochar, wood vinegar (natural soil amendment), and smelting slag, are all recycled and reused. There is no solid waste discharge throughout the entire process, which complies with environmental protection policy requirements.

[0026] This process involves cross-industry coupling of agriculture, forestry, metallurgy, chemical industry, and green energy, and will have a disruptive impact on long-process steelmaking using coke, providing a disruptive technology for solving the carbon emission reduction problem in the steel industry.

[0027] Production plans can be flexibly adjusted according to the market demand for green iron, green gas, green electricity, green hydrogen, green methanol, and green ammonia.

[0028] Raw material composition 1. Biomass raw materials: any one or more of sawdust, straw, bamboo shavings, nutshells, and agricultural and forestry processing waste; after drying, the moisture content is ≤8%, the particle size is 10-20mm, and the fixed carbon content is ≥18%; 2. Iron oxides: at least one of iron ore (Fe2O3, Fe3O4), ilmenite, and red mud, with a TFe content of 35-68% and a particle size of φ10-20mm after pelletizing; 3. Water supply: Industrial pure water, used for green electrolysis of water to produce high-purity green hydrogen; 4. Heating medium: Biomass low-calorific-value gas (only for external heating of vertical furnace).

[0029] Process Flow Steps Step 1: Raw material pretreatment Biomass raw materials are dried in a dryer and screened in a crusher to obtain granular materials with a moisture content of ≤8% and a particle size of 10-20mm. Iron oxide powder is mixed with a binder to form balls with a particle size of φ10-20mm, which are then dried to remove free water before use.

[0030] Step 2: Vertical shaft furnace external heating segmented integrated reduction The pretreated biomass feedstock is mixed with iron oxide pellets at a mass ratio of 1 to 2:1 and fed into an externally heated vertical furnace. A slight positive pressure (5-500 Pa) is maintained inside the furnace, and oxygen is strictly isolated. A segmented heating integrated process is employed. The upper section is temperature-controlled at 550–800℃ to achieve biomass pyrolysis and gas production, producing pyrolysis gas containing methane, hydrogen, carbon monoxide, and carbon dioxide; the biochar and iron ore produced after biomass pyrolysis move downwards into the reduction section.

[0031] The lower section is controlled at 800-1200℃, utilizing the residual hydrogen and carbon from biomass pyrolysis to reduce iron oxides, achieving a metallization rate greater than 93%, with the reduced gas moving upwards; the sponge iron and remaining residual carbon, after cooling (temperature less than 50℃), rise from the bottom. The total residence time of the materials is 6 to 14 hours. The furnace top produces green syngas containing H2, CO and CH4, and the furnace bottom produces coarse sponge iron with a metallization rate of ≥93%. This process does not require an air separation oxygen production unit, and biomass completely replaces green hydrogen as the reducing medium.

[0032] Step 3: Gas purification and green fuel purification separation The green syngas produced from the top of the vertical shaft furnace undergoes dust removal, cooling to remove bio-oil and wood vinegar, and drying and dehydration. It can be directly used as green fuel to replace fossil energy used in industry. Alternatively, it can be sent to a pressure swing adsorption (PSA) unit to remove carbon dioxide and separate and purify green methane with a purity of ≥98%, which can be exported as an independent finished product. The remaining carbon monoxide and hydrogen are used as raw materials for downstream synthetic chemical products.

[0033] Step 4: Precise hydrogen preparation through green electricity electrolysis of water The alkaline electrolyzer, powered by wind and solar green electricity, electrolyzes industrial pure water to produce high-purity green hydrogen with a purity ≥99.99%. The online hydrogen-carbon ratio monitoring system provides real-time feedback on the composition of syngas, automatically adjusts the green hydrogen injection flow rate with a response time ≤5 seconds, and forcibly locks the hydrogen-carbon ratio required for methanol synthesis to H2 / CO = 1.9~2.1:1.

[0034] Step 5: Syngas purification coupled with green methanol synthesis The syngas, precisely proportioned in step 4, is subjected to dry desulfurization (sulfur content <0.1ppm after desulfurization) and sent to a low-pressure methanol synthesis tower; crude methanol is synthesized under pressure of 4.0-8.0MPa and temperature of 200-260℃; crude methanol is then subjected to atmospheric distillation and pressurized distillation to obtain high-quality green methanol with a purity ≥99.9%.

[0035] Step 6: Preparation of green iron by electrofusion of coarse sponge iron. After the residual carbon in the crude sponge iron produced in step 2 is separated by magnetic separation, it is directly fed into the green electric arc furnace and heated to 1550-1650℃ using wind power and photovoltaic green electricity. After melting, slag-iron separation, refining and purification, industrial high-purity green iron with a purity of ≥95% is obtained. The smelting slag is collected and used for building material preparation.

[0036] Step 7: By-product resource utilization The bio-oil and wood vinegar produced as byproducts in step 3, along with the smelting slag generated in step 6, are all recycled and stored for external sale, achieving full-process resource recycling.

[0037] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for producing green energy by reducing iron oxide with biomass instead of green hydrogen, characterized in that, Includes the following steps: Step 1: Dry and crush the biomass raw materials to a moisture content ≤8% and a particle size of 10-20mm. The biomass raw materials are any one or more of sawdust, straw, bamboo shavings, fruit shells, and agricultural and forestry processing waste. Add a binder to the iron oxide powder to form pellets with a particle size of φ10-20mm and dry them. The iron oxide is at least one of iron ore (Fe2O3, Fe3O4), ilmenite, and red mud, with a TFe content of 35-68%. Step 2: Mix biomass raw materials and iron oxide balls at a mass ratio of 1 to 2:1 and feed them into an externally heated vertical shaft furnace. Maintain a slight positive pressure (5-50 Pa) inside the furnace and isolate oxygen. Use a segmented heating integrated process: control the temperature of the upper section at 550-800℃ to achieve biomass pyrolysis and gas production, and control the temperature of the lower section at 800-1200℃ to achieve carbothermic reduction of iron ore. The total residence time of the material is 6-14 hours. The externally heated vertical shaft furnace does not have an air separation oxygen production device. Carbon and volatiles generated by biomass pyrolysis replace green hydrogen as the reducing medium. Green syngas containing H2, CO, and CH4 is produced at the top of the furnace, and coarse sponge iron with a metallization rate of ≥93% is generated at the bottom of the furnace. Step 3: After the green syngas from Step 2 is subjected to dust removal, cooling to remove bio-oil and wood vinegar, and drying and dehydration, it is sent to a pressure swing adsorption (PSA) device to remove carbon dioxide and separate and purify to obtain green fuel gas with a purity of ≥98%. The green fuel gas is exported as an independent finished product. Step 4: Use wind power or photovoltaic green electricity to drive an electrolyzer to electrolyze industrial pure water to prepare high-purity green hydrogen with a purity of ≥99.99%. The high-purity green hydrogen is then introduced into the syngas after decarbonization in Step 3 according to a preset ratio. The hydrogen-to-carbon ratio (H2 / CO) of the syngas is controlled online and strictly locked at 1.9 to 2.1:1, without the need for a carbon monoxide conversion unit. Step 5: The syngas after step 4 is subjected to dry desulfurization (sulfur content after desulfurization <0.1ppm) and sent to a low-pressure methanol synthesis tower to synthesize crude methanol under the conditions of pressure 4.0~8.0MPa and temperature 200~260℃. After distillation, green methanol with a purity ≥99.9% is obtained. Step 6: The crude sponge iron produced in Step 2 is directly fed into the green electric arc furnace and heated to 1550-1650℃ using wind power and photovoltaic green electricity. After melting, slag-iron separation, refining and purification, green iron with a purity of ≥95% is obtained. The smelting slag is used for building material preparation. The bio-oil and wood vinegar produced as byproducts of Step 7 and Step 3, as well as the smelting slag from Step 6, are all recycled as resources, with no solid waste, hazardous waste, or waste gas discharged throughout the entire process.

2. The method for producing green energy by replacing green hydrogen with biomass to reduce iron oxides and co-producing green iron according to claim 1, characterized in that, The biomass is any one or more of the following: wood chips, straw, bamboo chips, fruit shells, and agricultural and forestry processing waste.

3. The method for producing green energy by replacing green hydrogen with biomass to reduce iron oxides and co-producing green iron according to claim 1, characterized in that, The iron oxides are iron ore (Fe2O3, Fe3O4), ilmenite, red mud, and iron-containing waste slag from the smelting industry, with a TFe content of 35-68%.

4. The method for producing green energy by replacing green hydrogen with biomass to reduce iron oxides and co-producing green iron according to claim 1, characterized in that, The externally heated vertical furnace adopts segmented temperature control, with the upper section at 550–800℃ and the lower section at 800–1200℃.

5. The method for producing green energy by replacing green hydrogen with biomass to reduce iron oxides and co-producing green iron according to claim 1, characterized in that, The biomass replaces green hydrogen as the sole reducing medium, without the addition of green hydrogen, fossil hydrogen, or other reducing gases. The energy consumption of the reduction process is reduced by more than 40% compared to the green hydrogen reduction process for iron ore.

6. The method for producing green energy by replacing green hydrogen with biomass to reduce iron oxides and co-producing green iron according to claim 1, characterized in that, In the segmented heating integrated process of the externally heated vertical furnace, the hydrogen, carbon monoxide, methane, and carbon dioxide produced by the upper biomass pyrolysis and the carbon monoxide and carbon dioxide produced by the lower carbothermal reduction together constitute green syngas.

7. The method for producing green energy by replacing green hydrogen with biomass to reduce iron oxides and co-producing green iron according to claim 1, characterized in that, In the aforementioned cogeneration process, the industrial chain can be further extended to green energy sources such as green electricity, green hydrogen, green alcohol, and green ammonia, based on market demand, and all products meet the requirements for negative carbon certification and CCER carbon asset declaration.

8. The method for producing green energy by replacing green hydrogen with biomass to reduce iron oxides and co-producing green iron according to claim 1, characterized in that, In step two, the iron oxide can be selected from low-grade iron ore with TFe content of 30-60%, which can be directly used for the reduction reaction without the need for mineral processing and enrichment.

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