Biomass promoted recovery and upgrading of converter coal gas

Abstract

This invention relates to a method for promoting the recovery and upgrading of converter gas using biomass. Utilizing the high temperature and pressure conditions of converter gas, the method achieves the pyrolysis and carbonization of biomass straw resources. Through the gasification reaction between the biomass pyrolysis carbon and the CO2 and H2O in the high-temperature gas, the recovery and upgrading of converter gas are promoted. The upgraded converter gas has higher CO and H2 volume percentages, higher gas recovery rate, and higher calorific value. The volume percentage range of the upgraded gas chemical composition is: CO 63.26–72.83%, CO2 5.87–11.82%, O2 0.42–0.72%, H2 3.05–5.24%, N2 15.28–17.85%, CH4 0.62–0.94%. The combined volume percentages of CO and H2 in the upgraded coal gas are 66.31%–78.07%, and the gas volume per ton of steel is 108.35–125.87 m³. 3 The calorific value of the gas increased to 6019–7287 kJ / m³. 3 This technology overcomes the problems of low gas recovery, low gas quality and low calorific value in traditional converters. It can significantly improve the recovery rate, gas quality and calorific value of converter gas, realize the resource utilization and high added value of renewable straw resources, effectively reduce the environmental pollution caused by straw burning, and achieve zero carbon dioxide emissions from biomass fuels.

Description

Technical Field

[0001] This invention relates to a method, specifically a method for promoting the recovery, quality improvement, and quantity enhancement of converter gas using biomass, belonging to the field of energy technology in the metallurgical industry. Background Technology

[0002] Converter steelmaking is a major steelmaking process in my country. The converter smelting process generates a large amount of converter gas, which is an important secondary energy source for the steel industry. The converter gas production is approximately 80–120 m³ / min. 3 / ton of steel can be used as a raw material for producing high-value-added chemical products, and can also be applied to ladle baking, gas-fired power generation, etc. The efficient and high-quality recovery and utilization of converter gas is an important means to reduce energy consumption and promote economic benefits in steel enterprises. Fully utilizing converter gas is of great significance for improving energy efficiency and reducing carbon dioxide emissions. Therefore, achieving high-quality recovery of converter gas is beneficial to increasing steelmaking efficiency and effectively reducing greenhouse gas emissions. Currently, converter gas recovery mainly suffers from problems such as small gas volume, low quality, high CO2 emissions, and low added value. Therefore, how to effectively improve the gas recovery volume and calorific value is of great significance to energy conservation, emission reduction, and dual-carbon goals of steel enterprises. However, traditional measures such as converter structure adjustment, oxygen flow and lance position control, and equipment parameter adjustment are difficult to substantially improve the converter gas volume and calorific value. Existing converter gas upgrading technologies all involve cooling and dust removal of converter gas before reforming or using it as a raw material for chemical production; there is currently no technology for direct high-temperature online reforming and upgrading of converter gas. Therefore, there is an urgent need to develop a new technology for the recovery, quality improvement, and quantity enhancement of converter gas, which is of great significance for promoting energy conservation and emission reduction in steel enterprises, improving environmental quality, and promoting the comprehensive green transformation of economic and social development. Summary of the Invention

[0003] This invention addresses the technical problems existing in the prior art by providing a biomass-based method for promoting the recovery, quality improvement, and quantity enhancement of converter gas. This solution overcomes the issues of low converter gas recovery rate, low gas quality, and low calorific value associated with traditional methods. This technology can significantly improve the recovery rate, gas quality, and calorific value of converter gas, enabling the resource utilization and high-value-added use of renewable straw resources, effectively reducing environmental pollution caused by straw burning, and achieving zero carbon dioxide emissions from biomass fuels.

[0004] To achieve the above objectives, the technical solution of the present invention is as follows: a method for promoting the recovery, quality improvement, and quantity enhancement of converter gas using biomass, characterized in that it utilizes the high temperature and high pressure conditions of converter gas to achieve the pyrolysis and carbonization of biomass straw resources. Through the gasification reaction between the pyrolysis carbon of biomass straw and CO2 and H2O in the high-temperature gas, the recovery, quality improvement, and quantity enhancement of converter gas are promoted. The method includes the following steps:

[0005] (1) Pretreatment of biomass straw resources;

[0006] (2) Online weighing and feeding of biomass straw resources;

[0007] (3) Pyrolysis carbonization and high-temperature gasification of biomass straw resources in converter flue.

[0008] The biomass straw resources include corn stalks, wheat straw, rice straw, and rapeseed straw. The volume percentage range of the chemical composition of the upgraded coal gas after the pyrolysis carbon of biomass straw and the high-temperature coal gas are as follows: CO 63.26–72.83%, CO2 5.87–11.82%, O2 0.42–0.72%, H2 3.05–5.24%, N2 15.28–17.85%, and CH4 0.62–0.94%. The sum of the volume fractions of CO and H2 in the upgraded converter gas is 66.31–78.07%, and the gas volume per ton of steel is 108.35–125.87 m³. 3 The calorific value of the gas is 6019–7287 kJ / m³. 3 The addition of biomass straw resources to the converter gasification flue significantly improved the recovery rate and calorific value of converter gas, achieving both improved quality and quantity of converter gas.

[0009] The pretreatment of biomass straw resources in step (1) involves naturally drying the biomass straw resources at room temperature, and then crushing the biomass straw resources to 5-30 mm using a biomass straw crusher with a blowing rate of 10-40 kg / min.

[0010] In step (2), the online weighing and feeding of biomass straw resources refers to feeding the crushed biomass straw resources into the powder spraying tank through the feeding hopper, where it is weighed online. The feed rate is then adjusted by a frequency converter feeder, and the material is then transported to the mixing injector and sprayed through a pipeline to the spray gun into the converter gasification flue. The biomass straw injection rate is 10–40 kg / min.

[0011] In step (3), the pyrolysis and carbonization of biomass straw resources refer to the process where biomass straw raw materials enter the high-temperature flue of the converter, release volatiles, and undergo pyrolysis at high temperatures. The resulting gas and carbon react with the gasification medium (oxygen, water vapor, etc.) in the flue gas in the oxidation zone and then burn. The oxidized gas contains some non-combustible gases, such as CO2 and H2O, which are reduced through a reduction reaction. Ultimately, a mixture containing CO, H2, CH4, and some unsaturated hydrocarbons (C) is generated. m H n The mixed converter gas.

[0012] The combined volume percentages of CO and H2 in the upgraded coal gas are 66.31%–78.07%, and the gas volume per ton of steel is 108.35–125.87 m³. 3 The calorific value of the gas is 6019–7287 kJ / m³. 3 .

[0013] The CO concentration of the upgraded coal gas was increased by 9.91–15.29% compared to the original coal gas, and the amount of coal gas and the calorific value of the coal gas were increased by 13.91–32.33% and 9.72–34.1% respectively compared to the original coal gas.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0015] 1. Biomass straw resources are abundant and easy to obtain. Compared with the current pulverized coal catalytic CO2 gasification, it has many advantages, such as low sulfur content, high volatile matter, and large specific surface area, which greatly helps to reduce the CO2 content in coal gas.

[0016] 2. The heat released during the oxidation-reduction stage of biomass straw resources is sufficient to meet the heat requirements of the drying and pyrolysis stages, and can raise the temperature of the coal gas and accelerate the reaction rate.

[0017] 3. Biomass straw resources contain organic elements such as C, H, O, and N, which can undergo gasification reactions under high temperature and low oxygen conditions, increasing the content of combustible gases such as CO, H2, and CH4 in the coal gas, extending the time of converter gas recovery, and improving the quantity and quality of coal gas recovery. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the process flow of the method of the present invention;

[0019] Figure 2 The effect of biomass straw injection rate on the O2 and CO content in converter gas was investigated.

[0020] Figure 3 The effect of biomass straw injection rate on converter gas recovery and calorific value.

[0021] In the diagram: 1. Converter, 2. Movable fume hood, 3. Spray gun, 4. Primary dust collector, 5. Feed pipe, 6. Gas-solid injector, 7. Variable frequency feeder, 8. Online weighing device, 9. Powder spraying tank, 10. Pressure gauge, 11. Feeding hopper. Detailed Implementation

[0022] To enhance understanding of the present invention, the embodiments will be described in detail below with reference to the accompanying drawings.

[0023] Example 1: Dried corn stalk biomass is crushed to 5-10mm and fed into a powder spraying tank via a feeding hopper, where it is weighed online. The feed rate is then adjusted by a variable frequency feeder, setting the original spraying rate of corn stalks to 10 kg / min. The feed is then transported to a mixing injector and sprayed through a pipeline into the converter's gasification flue. After entering the high-temperature flue of the converter, the corn stalks release volatiles and undergo pyrolysis at high temperatures (300℃-600℃). The pyrolysis gases and carbon react with the gasification medium (oxygen, water vapor, etc.) in the oxidation zone and burn. The oxidized CO2 and H2O gases undergo a gasification reaction with the pyrolysis carbon from corn stalks at a temperature of 900–1350℃, ultimately producing converter gas with a high CO concentration. The volume percentage chemical composition of this converter gas is as follows: CO 63.26%, CO2 11.82%, O2 0.72%, H2 3.05%, N2 15.28%, and CH4 0.62%. Through the injection of biomass corn stalk raw materials, the CO concentration of the gas was increased by 9.91%, the combined volume fraction of CO and H2 reached 66.31%, and the gas production per ton of steel increased to 108.35 m³. 3 The calorific value of the gas increased to 6019 kJ / m³. 3 The amount of gas and the calorific value of the gas increased by 13.91% and 9.72% respectively compared with the original gas.

[0024] Example 2: Dried wheat straw biomass is crushed to 5-15mm and fed into a powder spraying tank via a feeding hopper, where it is weighed online. The feed rate is then adjusted by a variable frequency feeder, setting the original straw spraying rate to 20 kg / min. The feed is then transported to a mixing injector and sprayed through a pipeline into the converter's gasification flue. After entering the high-temperature flue of the converter, the corn straw biomass releases volatiles and undergoes pyrolysis at high temperatures (250℃-550℃). The pyrolysis gases and carbon react with the gasification medium (oxygen, water vapor, etc.) in the oxidation zone and burn. The oxidized CO2 and H2O gases undergo a gasification reaction with the pyrolysis carbon from corn stalks at a temperature of 850–1300℃, ultimately producing converter gas with a high CO concentration. The volume percentage chemical composition of this converter gas is as follows: CO 67.84%, CO2 9.86%, O2 0.48%, H2 3.65%, N2 16.32%, and CH4 0.71%. Through the injection of biomass corn stalk raw materials, the CO concentration of the gas was increased by 10.3%, the combined volume fraction of CO and H2 reached 71.49%, and the gas production per ton of steel increased to 115.74 m³. 3 The calorific value of the gas increased to 6553 kJ / m³. 3 The amount of gas and the calorific value of the gas increased by 21.68% and 17.08% respectively compared with the original gas.

[0025] Example 3: Dried rice straw biomass is crushed to 5-20mm and fed into a powder spraying tank via a feeding hopper, where it is weighed online. The feed rate is then adjusted by a frequency converter, setting the original straw spraying rate to 30 kg / min. The material is then transported to a mixing injector and sprayed through a pipeline into the converter's gasification flue. After entering the high-temperature flue of the converter, the rice straw releases volatiles and undergoes pyrolysis (pyrolysis) at high temperatures (300℃-650℃). The pyrolysis gases and carbon react with the gasification medium (oxygen, water vapor, etc.) in the oxidation zone and burn. The oxidized CO2 and H2O gases undergo a gasification reaction with the pyrolysis carbon from corn stalks at a temperature of 800–1250℃, ultimately producing converter gas with a high CO concentration. The volume percentage chemical composition of this converter gas is as follows: CO 70.57%, CO2 7.86%, O2 0.45%, H2 4.62%, N2 17.25%, and CH4 0.83%. Through the injection of biomass corn stalk raw materials, the CO concentration of the gas was increased by 13.03%, the combined volume fraction of CO and H2 reached 75.19%, and the gas production per ton of steel increased to 121.44 m³. 3 The calorific value of the gas increased to 6942 kJ / m³. 3 The amount of gas and the calorific value of the gas increased by 27.67% and 27.75% respectively compared with the original gas.

[0026] Example 4: Dried rapeseed stalk biomass is crushed to 5-25mm and fed into a powder spraying tank via a feeding hopper, where it is weighed online. The feed rate is then adjusted by a frequency converter, setting the original straw spraying rate to 40 kg / min. The material is then transported to a mixing injector and sprayed through a pipeline into the converter's gasification flue. After entering the high-temperature flue of the converter, the rapeseed stalk releases volatiles and undergoes pyrolysis at high temperatures (350℃-700℃). The pyrolysis gases and carbon react with the gasification medium (oxygen, water vapor, etc.) in the oxidation zone and burn. The oxidized CO2 and H2O gases undergo a gasification reaction with the pyrolysis carbon from corn stalks at a temperature of 750–1200℃, ultimately producing converter gas with a high CO concentration. The volume percentage chemical composition of this converter gas is: CO 72.83%, CO2 5.87%, O2 0.42%, H2 5.24%, N2 17.85%, and CH4 0.94%. Through the injection of biomass corn stalk raw materials, the CO concentration of the gas was increased by 15.29%, the sum of the CO and H2 volume fractions reached 78.07%, and the gas production per ton of steel increased to 125.87 m³. 3 The calorific value of the gas increased to 7287 kJ / m³. 3 The amount of gas and the calorific value of the gas increased by 32.33% and 34.1% respectively compared with the original gas.

[0027] It should be noted that the above embodiments are not intended to limit the scope of protection of the present invention. Equivalent transformations or substitutions made based on the above technical solutions all fall within the scope of protection of the claims of the present invention.

Claims

1. A method for promoting the recovery, quality improvement, and quantity enhancement of converter gas using biomass, characterized in that, The method utilizes the high temperature and high pressure conditions of converter gas to achieve the pyrolysis and carbonization of biomass straw resources. Through the gasification reaction between the pyrolysis carbon of biomass straw and CO2 and H2O in the high-temperature gas, the recovery, quality improvement, and quantity enhancement of converter gas are promoted. The method includes the following steps: (1) Pretreatment of biomass straw resources; (2) Online weighing and feeding of biomass straw resources; (3) Pyrolysis carbonization and high-temperature gasification of biomass straw resources in converter flue.

2. The method for promoting the recovery, quality improvement, and quantity enhancement of converter gas using biomass according to claim 1, characterized in that, The biomass straw resources are corn stalks, wheat straw, rice straw, and rapeseed straw. The volume percentage range of the chemical composition of the upgraded coal gas after the pyrolysis carbon of biomass straw and the high-temperature coal gas are: CO 63.26-72.83%, CO2 5.87-11.82%, O2 0.42-0.72%, H2 3.05-5.24%, N2 15.28-17.85%, CH4 0.62-0.94%. The sum of the volume fractions of CO and H2 in the upgraded converter gas is 66.31-78.07%, and the gas volume per ton of steel is 108.35-125.87 m³. 3 The calorific value of the gas is 6019–7287 kJ / m³. 3 .

3. The method for promoting the recovery, quality improvement, and quantity enhancement of converter gas using biomass according to claim 1, characterized in that, The pretreatment of biomass straw resources in step (1) involves naturally drying the biomass straw resources at room temperature, and then crushing the biomass straw resources to 5-30 mm using a biomass straw crusher with a blowing rate of 10-40 kg / min.

4. The method for promoting the recovery, quality improvement, and quantity enhancement of converter gas using biomass according to claim 1, characterized in that, The online weighing and feeding of biomass straw resources mentioned in step (2) refers to feeding the crushed biomass straw resources into the powder spraying tank through the feeding hopper, weighing them online in the spraying tank, adjusting the feeding amount by the frequency converter feeder, and then conveying them to the mixing sprayer for spraying, and then conveying them through the pipeline to the spray gun for spraying into the converter gasification flue. The spraying rate of biomass straw resources is 10-40 kg / min.

5. The method for promoting the recovery, quality improvement, and quantity enhancement of converter gas using biomass according to claim 1, characterized in that, The pyrolysis carbonization and high-temperature gasification of biomass straw resources mentioned in step (3) refer to the process where biomass straw raw materials enter the high-temperature flue of the converter, release volatiles, and are then pyrolyzed (pyrolyzed) at high temperatures. The pyrolyzed gas and carbon react with the gasification medium (oxygen, water vapor, etc.) in the flue gas in the oxidation zone and then burn.

6. The method for promoting the recovery, quality improvement, and quantity enhancement of converter gas using biomass according to claim 2, characterized in that, The combined volume percentages of CO and H2 in the upgraded coal gas are 66.31%–78.07%, and the gas volume per ton of steel is 108.35–125.87 m³. 3 The calorific value of the gas is 6019–7287 kJ / m³. 3 .

7. The method for promoting the recovery, quality improvement, and quantity enhancement of converter gas using biomass according to claim 2, characterized in that, The CO concentration of the upgraded coal gas was increased by 9.91–15.29% compared to the original coal gas, and the coal gas volume and calorific value were increased by 13.91–32.33% and 9.72–34.1% respectively compared to the original coal gas.

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