A sintering high-efficiency carbon emission reduction method of biomass ignition coupled with hydrogen-rich fuel gas injection

Abstract

The application discloses a kind of biomass ignition coupling hydrogen-rich fuel gas injection sintering efficient carbon emission reduction method.Sintering material is sequentially balling, distributing, igniting and sintering, the main improvement point is: (1) biomass fuel is uniformly arranged on the surface of sintering material;(2) the surface of sintering material is divided into area-1 to area-4 from the distribution end to the discharge end, the high-temperature section of the circular cooler is recycled to area-1, and hydrogen-rich gas, hydrogen-rich gas+oxygen, hydrogen-rich gas and steam are respectively injected into area-1 to area-4.The method uses biomass fuel to ignite, significantly reduces the energy consumption of ignition, and effectively couples the gas injection sintering technology mainly using fuel gas, adjusts the heat distribution in the material layer to achieve uniform heating and high-quality sintering, significantly improves the sinter production quality index, while reducing process energy consumption, solid fuel consumption and NOx, CO2 emissions, achieving low-carbon sintering with low cost and low pollutant emissions.

Description

TECHNICAL FIELD

[0001] The present application relates to a sintering high-efficiency carbon emission reduction method, in particular to a biomass ignition coupled with hydrogen-rich gas injection sintering high-efficiency carbon emission reduction method, and belongs to the sintering industry in the field of steel metallurgy. BACKGROUND

[0002] The CO2 emission of the steel industry ranks first in the manufacturing industry. As the first process of steel production, sintering accounts for 10% of the total energy consumption of the steel industry, of which solid fuel consumption accounts for 75-80%, and ignition fuel consumption accounts for 5-10%. The ignition process and solid fuel combustion process of sintering will produce a large amount of CO2, which is the main source of sintering flue gas CO2. Therefore, using a cleaner ignition method and reducing solid fuel consumption is an important way to achieve high-efficiency carbon reduction in the sintering process, and is of great significance to clean production of the steel industry.

[0003] At present, most of the carbon reduction, energy saving and emission reduction measures are single technologies, which have certain carbon reduction effect, but all have defects. In terms of ignition, most of them optimize the ignition process through micro-negative pressure ignition, oxygen-rich ignition or use new burners to reduce ignition energy consumption, but the essence is still CO-rich gas combustion heating. Not only is the ignition temperature high, but the heat loss is also large, and a large amount of CO2 will be released. In the sintering process, oxygen enrichment, gas injection or steam injection can effectively reduce fuel consumption. Spraying oxygen not only can improve fuel utilization efficiency, but also can promote the generation of calcium ferrite, but its cost is high; spraying gas can effectively adjust the heat distribution of the material layer and strengthen the sintering of the upper material layer. In 2009, Japan JFE Steel Company and Kyushu University developed and applied sintering material surface gas injection technology, which realized low-carbon high-quality sintering under the condition of reducing the proportion of solid fuel. This technology increases the high-temperature retention time, optimizes the overall heat uniformity of the sintering material surface, and improves the sintering effect of the upper material layer and the sinter production quality index. In June 2017, China Shaogang and Zhongye Changtian Company carried out coke oven gas injection test, which effectively reduced the process energy consumption and reduced the emission of sintering flue gas pollutants; spraying water vapor can speed up the heat transfer and sintering speed of the material layer, and reduce CO emission, but the carbon reduction proportion is low. In terms of fuel, biomass energy is widely considered as a carbon zero energy source, which has the characteristics of wide source, large resource quantity and renewable, and is the best substitute for fossil energy. The current research mainly focuses on using biomass fuel to replace fossil fuels such as anthracite and coke powder for sintering, but biomass fuel generally has a higher thermal chemical reaction activity than fossil fuels, resulting in a lower replacement ratio. In general, the current sintering carbon reduction technology has limitations, and how to effectively combine various technologies to achieve higher carbon reduction is the current research focus. SUMMARY

[0004] To address the technical problems of high ignition temperature, large CO2 emissions, and uneven heat distribution in the sintering bed in existing technologies, the present invention aims to provide a highly efficient carbon emission reduction method for sintering by coupling biomass ignition with hydrogen-rich gas injection. This method improves upon existing sintering ignition methods by using biomass fuel as the initial heat source, significantly reducing ignition energy consumption. Furthermore, it effectively couples with gas injection sintering technology, which is mainly based on gas, to adjust the heat distribution within the material bed and achieve uniform and high-quality sintering, thereby significantly improving the quality indicators of sintered minerals. At the same time, it reduces process energy consumption, solid fuel consumption, and NOx and CO2 emissions, achieving low-cost, low-pollutant emission, and low-carbon sintering.

[0005] In order to achieve the above technical objectives, the present invention provides a sintering high-efficiency carbon emission reduction method of biomass ignition coupled with hydrogen-rich gas injection. The method involves pelletizing, feeding, igniting and sintering the sintering material in sequence. The main improvements include (1) and (2).

[0006] (1) Biomass fuel is evenly distributed on the sintering surface;

[0007] (2) Divide the sintering material surface from the feeding end to the unloading end into region-1, region-2, region-3 and region-4 in sequence, and region-1, region-2, region-3 and region-4 account for 10-20%, 15-25%, 10-20% and 35-65% of the total area of ​​the sintering material surface, respectively; circulate the hot exhaust gas of the high temperature section of the annular cooler to region-1, and at the same time inject hydrogen-rich gas into region-1, inject hydrogen-rich fuel gas and oxygen into region-2, inject hydrogen-rich fuel gas into region-3, and inject water vapor into region-4.

[0008] This invention aims to solve the technical problems of high ignition temperature, large CO2 emissions, and uneven heat distribution in the sintering bed during the sintering process in existing technologies. Based on the sintering ignition regime and the characteristics of the sintering bed temperature distribution, the key to this invention lies in utilizing the circulating hot air from an annular cooler and biomass fuel for ignition, while simultaneously rationally planning the injection zones for hydrogen-rich gas, hydrogen-rich fuel gas, oxygen, and water vapor to improve the quality of sintered ore and reduce pollutant emissions. On one hand, by uniformly distributing biomass fuel on the sintering surface, and utilizing the high thermochemical reactivity and low ignition point of biomass fuel, high-temperature waste gas from the annular cooler can be circulated back to the sintering surface to ignite the biomass fuel, establishing an initial combustion zone on the sintering surface. This replaces conventional gas igniters, significantly reducing the ignition temperature and energy consumption in the sintering process. Simultaneously, the injection of hydrogen-rich gas, primarily hydrogen, into the ignition zone generates water vapor, a combustion product that promotes efficient combustion of the biomass fuel, ensuring full utilization of its chemical energy. On the other hand, the gas injection area of ​​the sintering material surface should be rationally planned. Based on the characteristics that the heat storage of the sintering material layer gradually increases from the surface layer, middle layer and lower layer, while the demand for additional heat gradually decreases, hydrogen-rich gas, hydrogen-rich fuel gas, oxygen and water vapor should be rationally injected into each area. The technical solution of this invention divides the gas injection area on the sintering material surface into four zones of appropriate size: Zone-1, Zone-2, Zone-3, and Zone-4. Zone-1 mainly uses biomass fuel combustion and gas-solid heat transfer from waste gas as heat sources to achieve the required heat for the surface layer. Hydrogen-rich gas, mainly composed of natural gas, is injected into Zone-2. Utilizing its combustion and heating characteristics near the solid fuel combustion zone, it further supplements the heat demand of the upper material layer. Injecting oxygen into Zone-2 ensures the stability of the sinter quality. Hydrogen-rich gas, mainly composed of natural gas, is injected into Zone-3 to meet the additional heat requirements of the middle and upper material layers. Low-concentration, low-pressure steam is injected into Zone-4 to provide a sufficient heat source by utilizing solid fuel combustion and the heat storage effect of the material layer. This achieves a uniform heat distribution along the height of the material layer, which is beneficial for efficiently reducing solid fuel consumption during the sintering process. Furthermore, the division of the gas injection zone is designed to broaden the high-temperature zone of the front sintering material surface exceeding 1200°C and ensure sufficient heat replenishment, extend the high-temperature holding time of the middle material layer, achieve balanced and stable heat distribution across all sintering material layers, and significantly reduce the amount of fossil fuel used. The addition of steam to the rear material layer improves fuel combustion efficiency, thereby improving the quality of sintered ore and reducing pollutant emissions.

[0009] As a preferred option, regions 1, 2, 3 and 4 account for 13-18%, 18-22%, 13-18% and 45-55% of the total area of ​​the sintering material, respectively.

[0010] As a preferred embodiment, the biomass fuel has the following particle size requirements: the mass content of particles smaller than 1 mm does not exceed 30%, the mass content of particles larger than 5 mm does not exceed 20%, the volatile matter mass content does not exceed 20%, and the calorific value is not less than 25 MJ / kg. Excessive content of particles smaller than 1 mm in the biomass fuel will lead to overly vigorous combustion, while excessive content of particles larger than 5 mm will lead to an excessively slow combustion rate. A lower volatile matter mass content can reduce emissions of gaseous pollutants such as NOx. Controlling the calorific value of the biomass fuel to above 25 MJ / kg can reduce the thickness of the biomass fuel layer on the feed surface, minimizing the negative impact on sintering permeability. As a more preferred embodiment, the biomass fuel includes biochar obtained from the pyrolysis of agricultural waste and / or forestry waste. Straw char is a common example.

[0011] As a preferred embodiment, the biomass fuel content on the sintering surface accounts for 0.1% to 0.5% of the total mass of the sintering material. When the biomass fuel content is less than 0.1% of the total mass of the sintering material, it is difficult to meet the ignition heat requirements. When the biomass fuel content is greater than 0.5% of the total mass of the sintering material, the biomass fuel on the sintering surface becomes too thick, affecting the sintering permeability. Therefore, controlling the amount of biomass fuel within an appropriate range is crucial to meet the ignition requirements without affecting sintering.

[0012] As a preferred embodiment, the temperature of the hot exhaust gas in the high-temperature section of the annular cooler is not lower than 400°C, so as to avoid the biomass fuel being unable to ignite due to excessively low temperature.

[0013] As a preferred embodiment, the amount of hydrogen-rich gas injected in zone-1 is measured as a hydrogen volume concentration of 0.1% to 0.4%. As a preferred embodiment, the amount of hydrogen-rich fuel gas injected in zone-2 is measured as a hydrogen fuel gas volume concentration of 0.5% to 1.5%. As a preferred embodiment, the amount of oxygen injected in zone-2 is measured as an oxygen volume concentration of 0.5% to 3%. As a preferred embodiment, the amount of hydrogen-rich fuel gas injected in zone-3 is measured as a hydrogen fuel gas volume concentration of 0.3% to 0.6%. As a preferred embodiment, the amount of water vapor injected in zone-4 is measured as a water vapor volume concentration of 0.1% to 0.4%. As a preferred embodiment, the amount of oxygen injected in zone-2 is 1 to 2 times the amount of hydrogen-rich fuel gas injected in zone-2. The gas injection in each zone is mainly to regulate the uniformity of heat distribution in the sintering bed along its height during the sintering process. Based on the characteristic that the heat storage capacity of the sintering bed gradually increases from the surface, middle, and lower layers, and the demand for additional heat gradually decreases, zone-1 primarily uses biomass fuel combustion and gas-solid heat transfer from waste gas, while simultaneously injecting hydrogen to aid combustion, ensuring the heat required for the surface layer of the sintering bed is met. Zone-2 is injected with a relatively high concentration of hydrogen-rich fuel gas, utilizing its combustion and heating characteristics near the solid fuel combustion zone to further supplement the heat demand of the upper layer. Simultaneously, oxygen at a concentration of 1-2 times that of the hydrogen-rich fuel gas is injected to ensure the stability of the sinter quality. Zone-3 is injected with a relatively low concentration of hydrogen-rich fuel gas to meet the additional heat demand of the middle and upper layers. Zone-4 is injected with low-concentration, low-pressure steam, utilizing solid fuel combustion and the heat storage effect of the bed to provide a sufficient heat source, thereby achieving uniform heat distribution along the height of the bed and effectively reducing solid fuel consumption during the sintering process.

[0014] As a preferred embodiment, the injection height of each mixed gas in zones 1, 2, 3, and 4 is between 150mm and 250mm. Furthermore, all mixed gases are pre-mixed uniformly by a rectifier. When the injection height is below 150mm, the mixed gas fails to mix sufficiently with the air, resulting in uneven gas concentration distribution on the material surface. Above 250mm, the injected gas is prone to escape, affecting production safety.

[0015] As a preferred embodiment, any two adjacent regions of Region-1, Region-2, Region-3, and Region-4 are isolated by a partition plate to prevent gas flow between the regions.

[0016] As a preferred embodiment, the steam pressure of the water vapor does not exceed 2.0 MPa and the temperature does not exceed 300°C.

[0017] As a preferred embodiment, the hydrogen-rich gas includes at least one of hydrogen, coke oven gas, natural gas, and biomass pyrolysis gas.

[0018] Compared with the prior art, the beneficial technical effects of the technical solution of the present invention are as follows:

[0019] This invention, based on the sintering ignition system and the temperature distribution characteristics of the sintering bed, utilizes high-temperature hot waste gas and biomass fuel for ignition, while simultaneously planning the injection zones for hydrogen-rich gas, hydrogen-rich fuel gas, oxygen, and water vapor. This aims to improve sinter quality and reduce pollutant emissions. Ignition using high-temperature hot waste gas and biomass fuel results in a low ignition temperature and high safety. Biomass char powder supplements the heat of the sintering bed surface, and the injection of hydrogen-based gases, along with the water vapor in the combustion products, provides combustion assistance, overcoming the technical limitations of existing sintering bed gas injection technologies. The division of the gas injection zones aims to widen the high-temperature area exceeding 1200°C at the front of the sintering bed and ensure sufficient heat replenishment, extending the high-temperature maintenance time of the middle bed and achieving balanced and stable heat distribution across the entire sintering bed. This significantly reduces fossil fuel consumption. The injection of water vapor into the rear bed improves fuel combustion efficiency, further enhancing sinter quality and reducing pollutant emissions.

[0020] The technical solution of this invention utilizes the high thermochemical reactivity of biomass fuel and its significantly lower ignition point than fossil fuels. It circulates the high-temperature waste gas from the annular cooler back to the sintering material surface to ignite the biomass fuel, allowing it to burn on the sintering material surface and establish an initial combustion zone. This replaces conventional gas igniters and significantly reduces energy consumption in the sintering process.

[0021] The technical solution of this invention utilizes biomass fuel combustion to provide the energy required for ignition of the sintering material surface. At the same time, the hot exhaust gas from the high-temperature section of the annular cooler, which is circulated back to the sintering material surface, is recovered through gas-solid heat exchange with the surface material. Furthermore, the water vapor produced by the combustion product, mainly hydrogen-rich gas, is injected to promote the efficient combustion of biomass fuel and fully utilize its chemical energy.

[0022] Based on the characteristic that the heat storage capacity of the sintering material layer gradually increases from the surface, middle, and lower layers, and the demand for additional heat gradually decreases, the technical solution of this invention, after passing through zone-1 where biomass fuel combustion and gas-solid heat transfer from waste gas are the main heat sources, injects high-concentration hydrogen-rich gas, mainly natural gas, into zone-2. Utilizing its characteristic of combustion and heating in the area close to the solid fuel combustion zone, it further supplements the heat demand of the upper material layer. Oxygen with a concentration 1 to 2 times that of the gas in this zone is injected into zone-2 to ensure the stability of sinter quality. Low-concentration hydrogen-rich gas, mainly natural gas, is injected into zone-3 to meet the additional heat demand of the middle and upper material layers. Low-concentration, low-pressure steam is injected into zone-4 to provide a sufficient heat source by utilizing solid fuel combustion and the heat storage effect of the material layer, thereby achieving a uniform heat distribution along the height of the material layer, which is beneficial for efficiently reducing solid fuel consumption during the sintering process.

[0023] This invention utilizes clean and renewable biomass fuel bed combustion to replace conventional coal gas ignition, optimizes the heat distribution along the height of the sintering bed by segmented variable concentration injection of hydrogen-rich gas, increases the oxygen potential after high-concentration gas combustion in zone-2 by injecting oxygen, and improves fuel combustion efficiency in zone-4 by using steam to reduce CO emissions. It also recovers and utilizes waste heat from the high-temperature section of the annular cooler, thus constructing a novel high-efficiency carbon reduction method for sintering that integrates clean renewable energy ignition and clean hydrogen-rich energy to optimize the heat distribution of the sintering bed.

[0024] In summary, by adopting the technical solution of this invention, energy consumption in the sintering process can be reduced by more than 20%, solid fuel consumption can be reduced by more than 15%, and CO2 and NOx emissions can be reduced by more than 15%. Attached Figure Description

[0025] Figure 1 A schematic diagram of a sintering machine that couples biomass ignition with hydrogen-rich gas injection. Detailed Implementation

[0026] To facilitate understanding of the present invention, the present invention will be described more fully and in detail below with reference to preferred embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments.

[0027] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The patent terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention.

[0028] Unless otherwise specified, the various reagents and raw materials used in this invention are commercially available products or products that can be prepared by known methods.

[0029] Example 1

[0030] The sintering mixture is formulated as follows: 75.93% iron ore, 2.19% dolomite, 6.58% quicklime, 3.35% coke powder, and 11.95% sintering return ore. After the mixture is mixed and granulated, it is distributed in the sintering trolley and a 2mm thick layer of corn stalk char (0.1% of the mass of the sintering material) is distributed on the surface. The particle size distribution and calorific value are shown in Table 1. Then, high-temperature waste gas at 400℃ is injected into area-1, which accounts for 15% of the material surface, and hydrogen gas with a volume percentage of 0.1 vol% is injected at the same time. The negative pressure in area-1 is -5 kPa. After ignition, natural gas with a volume concentration of 0.5 vol% and oxygen with a volume concentration of 1 vol% were injected into area-2, which accounts for 20% of the material surface; natural gas with a volume concentration of 0.3 vol% was injected into area-3, which accounts for 15% of the material surface; and low-pressure water vapor at 200℃ and a volume concentration of 0.1 vol% was injected into area-4, which accounts for 50% of the material surface. The injection height was 150 mm. After sintering, the final yield, quality indicators and pollutant emission reduction effect of the sintered ore are shown in Table 2.

[0031] Example 2

[0032] The sintering mixture is formulated as follows: 75.93% iron ore, 2.19% dolomite, 6.58% quicklime, 3.177% coke powder, and 12.123% sintering return ore. After the mixture is granulated, it is distributed in the sintering trolley and a 6mm thick layer of corn stalk char (0.3% of the mass of the sintering material) is distributed on the surface. The particle size distribution and calorific value are shown in Table 1. Then, high-temperature waste gas at 400℃ is injected into area-1, which accounts for 15% of the material surface, and hydrogen gas with a volume percentage of 0.2 vol% is injected at the same time. The negative pressure in area-1 is -5 kPa. After ignition, natural gas with a volume concentration of 1 vol% and oxygen with a volume concentration of 2 vol% were injected into area-2, which accounts for 20% of the material surface; natural gas with a volume concentration of 0.4 vol% was injected into area-3, which accounts for 15% of the material surface; and low-pressure water vapor at 200℃ and a volume concentration of 0.2 vol% was injected into area-4, which accounts for 50% of the material surface. The injection height was 200 mm. After sintering, the final yield, quality indicators and pollutant emission reduction effect of the sintered ore are shown in Table 2.

[0033] Example 3

[0034] The sintering mixture is formulated as follows: 75.93% iron ore, 2.19% dolomite, 6.58% quicklime, 3.0% coke powder, and 12.3% sintering return ore. After the mixture is granulated, it is distributed in the sintering trolley and a 10mm thick layer of corn stalk char (0.5% of the mass of the sintering material) is distributed on the surface. The particle size distribution and calorific value are shown in Table 1. Then, high-temperature waste gas at 400℃ is injected into area-1, which accounts for 15% of the material surface, and hydrogen gas with a volume percentage of 0.4 vol% is injected at the same time. The negative pressure in area-1 is -5 kPa. After ignition, natural gas with a volume concentration of 1.5 vol% and oxygen with a volume concentration of 3 vol% were injected into area-2, which accounts for 20% of the material surface; natural gas with a volume concentration of 0.6 vol% was injected into area-3, which accounts for 15% of the material surface; and low-pressure water vapor at 200℃ and a volume concentration of 0.4 vol% was injected into area-4, which accounts for 50% of the material surface. The injection height was 250 mm. After sintering, the final yield, quality indicators and pollutant emission reduction effect of the sintered ore are shown in Table 2.

[0035] Comparative Example 1 (Conventional Sintering)

[0036] The sintering mixture was prepared as follows: 75.93% iron ore, 2.19% dolomite, 6.58% quicklime, 24.7% recycled ore, and 3.53% coke powder, with 11.77% recycled ore used for sintering. The mixture was thoroughly mixed, granulated into small balls, and distributed into the sintering trolley. Ignition was carried out at a temperature of 1050±50℃ and a negative pressure of -5kPa, with the ignition zone covering 8.5% of the material surface. The sintering negative pressure was -14kPa. The final yield and quality indicators of the sintered ore after sintering are shown in Table 2.

[0037] Comparative Example 2

[0038] The sintering mixture is formulated as follows: 75.93% iron ore, 2.19% dolomite, 6.58% quicklime, 3.53% coke powder, and 11.77% sintering return ore. After the mixture is granulated, it is distributed in the sintering trolley and a 6mm thick layer of corn stalk char (0.3% of the mass of the sintering material) is distributed on the surface. The particle size distribution and calorific value are shown in Table 1. Then, high-temperature waste gas at 400℃ is injected into area-1, which accounts for 15% of the material surface. The negative pressure on the material surface in area-1 is -5kPa. After ignition, natural gas with a volume concentration of 1.5 vol% and oxygen with a volume concentration of 3 vol% were injected into area-2, which accounts for 20% of the material surface; natural gas with a volume concentration of 0.6 vol% was injected into area-3, which accounts for 15% of the material surface; and low-pressure steam at 200℃ and with a volume concentration of 0.2 vol% was injected into area-4, which accounts for 50% of the material surface. After sintering, the final yield, quality indicators and pollutant emission reduction effect of the sintered ore are shown in Table 2.

[0039] Comparative Example 3

[0040] The sintering mixture is formulated as follows: 75.93% iron ore, 2.19% dolomite, 6.58% quicklime, 3.0% coke powder, and 12.3% sintering return ore. After the mixture is mixed and granulated, it is distributed in the sintering trolley and a 6mm thick layer of corn stalk char (0.3% of the mass of the sintering material) is distributed on the surface. The particle size distribution and calorific value are shown in Table 1. Then, high-temperature waste gas at 400℃ is injected into area-1, which accounts for 15% of the material surface, and hydrogen gas with a volume percentage of 0.4 vol% is injected at the same time. The negative pressure in area-1 is -5 kPa. After ignition, natural gas with a volume concentration of 1.5 vol% was injected into region-2, which accounts for 20% of the material surface; natural gas with a volume concentration of 0.6 vol% was injected into region-3, which accounts for 15% of the material surface; and low-pressure steam at 200℃ with a volume concentration of 0.4 vol% was injected into region-4, which accounts for 50% of the material surface. After sintering, the final yield, quality indicators, and pollutant emission reduction effect of the sintered ore are shown in Table 2.

[0041] Comparative Example 4

[0042] The sintering mixture is formulated as follows: 75.93% iron ore, 2.19% dolomite, 6.58% quicklime, 3.0% coke powder, and 12.3% sintering return ore. After the mixture is mixed and granulated, it is distributed in the sintering trolley and a 6mm thick layer of corn stalk char (0.3% of the mass of the sintering material) is distributed on the surface. The particle size distribution and calorific value are shown in Table 1. Then, high-temperature waste gas at 400℃ is injected into area-1, which accounts for 15% of the material surface, and hydrogen gas with a volume percentage of 0.4 vol% is injected at the same time. The negative pressure in area-1 is -5 kPa. After ignition, natural gas with a volume concentration of 1.5 vol% and oxygen with a volume concentration of 3 vol% were injected into area-2, which accounts for 20% of the material surface; no gas was injected into area-3; low-pressure water vapor at 200℃ and a volume concentration of 0.4 vol% was injected into area-4, which accounts for 50% of the material surface; after sintering, the final yield, quality indicators and pollutant emission reduction effect of the sintered ore are shown in Table 2.

[0043] Comparative Example 5

[0044] The sintering mixture was formulated as follows: 75.93% iron ore, 2.19% dolomite, 6.58% quicklime, 3.0% coke powder, and 12.3% sintering return ore. After mixing and granulation, the mixture was distributed in the sintering trolley, with a 6mm thick layer of corn stalk char (0.3% of the sinter mass) spread on the surface. The particle size distribution and calorific value are shown in Table 1. Then, high-temperature waste gas at 400℃ was injected into zone-1 (15% of the sinter surface), along with 0.4 vol% hydrogen gas. The negative pressure in zone-1 was -5 kPa. After ignition, natural gas (1.5 vol% by volume) and oxygen (3 vol% by volume) were injected into zone-2 (20% of the sinter surface); natural gas (0.6 vol% by volume) was injected into zone-3 (15% of the sinter surface); no gas was injected into zone-4. After sintering, the final yield, quality indicators, and pollutant emission reduction effect of the sinter are shown in Table 2.

[0045] Example 4

[0046] The sintering mixture is formulated as follows: 75.93% iron ore, 2.19% dolomite, 6.58% quicklime, 3.0% coke powder, and 12.3% sintering return ore. After the mixture is granulated, it is distributed in the sintering trolley and a 10mm thick layer of corn stalk char (0.5% of the mass of the sintering material) is distributed on the surface. The particle size distribution and calorific value are shown in Table 1. Then, high-temperature waste gas at 400℃ is injected into area-1, which accounts for 10% of the material surface, and hydrogen gas with a volume percentage of 0.4 vol% is injected at the same time. The negative pressure in area-1 is -5 kPa. After ignition, natural gas with a volume concentration of 1.5 vol% and oxygen with a volume concentration of 3 vol% were injected into area-2, which accounts for 25% of the material surface; natural gas with a volume concentration of 0.6 vol% was injected into area-3, which accounts for 25% of the material surface; and low-pressure water vapor at 200℃ and a volume concentration of 0.4 vol% was injected into area-4, which accounts for 40% of the material surface. The injection height was 250 mm. After sintering, the final yield, quality indicators and pollutant emission reduction effect of the sintered ore are shown in Table 2.

[0047] Comparative Example 6

[0048] The sintering mixture is formulated as follows: 75.93% iron ore, 2.19% dolomite, 6.58% quicklime, 3.0% coke powder, and 12.3% sintering return ore. After the mixture is mixed and granulated, it is distributed in the sintering trolley and a 10mm thick layer of corn stalk char (0.5% of the mass of the sintering material) is distributed on the surface. The particle size distribution and calorific value are shown in Table 1. Then, high-temperature waste gas at 400℃ is injected into area -1, which accounts for 5% of the material surface, and hydrogen gas with a volume percentage of 0.4 vol% is injected at the same time. The negative pressure in area -1 is -5 kPa. After ignition, natural gas with a volume concentration of 1.5 vol% and oxygen with a volume concentration of 3 vol% were injected into area-2, which accounts for 30% of the material surface; natural gas with a volume concentration of 0.6 vol% was injected into area-3, which accounts for 35% of the material surface; and low-pressure steam at 200℃ with a volume concentration of 0.4 vol% was injected into area-4, which accounts for 30% of the material surface. The injection height was 250 mm. After sintering, the final yield, quality indicators and pollutant emission reduction effect of the sintered ore are shown in Table 2.

[0049] Table 1. Particle size distribution and calorific value of corn straw charcoal

[0050]

[0051] Table 2. Sintered Ore Production, Quality Indicators, and Pollutant Emission Reduction Ratio

[0052]

[0053]

Claims

1. A high-efficiency carbon emission reduction method for sintering using biomass ignition coupled with hydrogen-rich gas injection, comprising sequentially pelletizing, distributing, igniting, and sintering the sintering material, characterized in that: Including (1) and (2); (1) Biomass fuel is evenly distributed on the sintering surface; (2) Divide the sintering material surface from the feeding end to the unloading end into region-1, region-2, region-3 and region-4 in sequence, and region-1, region-2, region-3 and region-4 account for 10-20%, 15-25%, 10-20% and 35-65% of the total area of ​​the sintering material surface, respectively; circulate the hot exhaust gas of the high temperature section of the annular cooler to region-1, and at the same time inject hydrogen-rich gas into region-1, inject hydrogen-rich fuel gas and oxygen into region-2, inject hydrogen-rich fuel gas into region-3, and inject water vapor into region-4.

2. The sintering high-efficiency carbon emission reduction method of biomass ignition coupled with hydrogen-rich gas injection according to claim 1, characterized in that: The biomass fuel shall have a particle size of less than 1 mm with a mass content of no more than 30% and a particle size of greater than 5 mm with a mass content of no more than 20%, a volatile matter content of no more than 20%, and a calorific value of no less than 25 MJ / kg.

3. A sintering-based high-efficiency carbon emission reduction method for biomass ignition coupled with hydrogen-rich gas injection according to claim 1 or 2, characterized in that: The amount of biomass fuel distributed on the sintering surface is 0.1% to 0.5% of the total mass of the sintering material.

4. A sintering-based high-efficiency carbon emission reduction method for biomass ignition coupled with hydrogen-rich gas injection according to claim 1 or 2, characterized in that: The biomass fuel includes biochar obtained by pyrolysis of agricultural waste and / or forestry waste.

5. The sintering high-efficiency carbon emission reduction method for biomass ignition coupled with hydrogen-rich gas injection according to claim 1, characterized in that: The temperature of the hot exhaust gas in the high-temperature section of the annular cooler is not lower than 400℃.

6. The sintering high-efficiency carbon emission reduction method for biomass ignition coupled with hydrogen-rich gas injection according to claim 1, characterized in that: The amount of hydrogen-rich gas injected in region-1 is measured as a hydrogen volume concentration of 0.1% to 0.4%. The amount of hydrogen-rich gas injected in region-2 is measured as a hydrogen-rich gas volume concentration of 0.5% to 1.5%. The amount of oxygen injected in zone-2 is measured as an oxygen volume concentration of 0.5% to 3%. The amount of hydrogen-rich gas injected in region -3 is measured as a hydrogen-rich gas volume concentration of 0.3% to 0.6%. The amount of water vapor injected in region-4 is measured as a water vapor volume concentration of 0.1% to 0.4%.

7. The sintering high-efficiency carbon emission reduction method for biomass ignition coupled with hydrogen-rich gas injection according to claim 6, characterized in that: The amount of oxygen injected in zone-2 is 1 to 2 times the amount of hydrogen-rich gas injected in zone-2.

8. The sintering high-efficiency carbon emission reduction method of biomass ignition coupled with hydrogen-rich gas injection according to claim 1, characterized in that: The injection height of each gas in regions 1, 2, 3 and 4 is 150mm to 250mm.

9. A sintering-based high-efficiency carbon emission reduction method for biomass ignition coupled with hydrogen-rich gas injection according to claim 1 or 8, characterized in that: Any two adjacent regions of Region-1, Region-2, Region-3, and Region-4 are isolated by a partition plate to prevent gas flow between the regions.

10. A sintering-based high-efficiency carbon emission reduction method for biomass ignition coupled with hydrogen-rich gas injection according to claim 1, 6, 7 or 8, characterized in that: The steam pressure of the water vapor does not exceed 2.0 MPa and the temperature does not exceed 300℃; The hydrogen-rich gas includes at least one of hydrogen, coke oven gas, natural gas, and biomass pyrolysis gas.

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