Hydrogen metallurgical method, system and application thereof using steel plant coal gas

Abstract

The application discloses a hydrogen metallurgical method and system using steel plant coal gas and application thereof. The method comprises the following steps: extracting hydrogen from coke oven gas to obtain hydrogen and first desorption gas, spraying the first desorption gas into a blast furnace; decarburizing converter gas to obtain converter decarburized gas; decarburizing and denitrifying hydrogen-based shaft furnace top gas to obtain recycled gas; decarburizing COREX gas to obtain COREX decarburized gas; mixing the hydrogen, the recycled gas and the COREX decarburized gas, or mixing the hydrogen, the recycled gas, the converter decarburized gas and the COREX decarburized gas as hydrogen-based shaft furnace reducing gas to produce sponge iron. The system comprises a coke oven gas treatment unit, a hydrogen-based shaft furnace top gas recycling unit, a heating furnace, a hydrogen-based shaft furnace, a blast furnace, and further comprises a COREX gas treatment unit, or further comprises a converter gas treatment unit and the COREX gas treatment unit. The application has important significance for using secondary energy of a steel plant, reducing primary energy consumption of a hydrogen-based shaft furnace and reducing carbon emission of a blast furnace.

Description

Technical Field

[0001] This invention relates to the field of hydrogen metallurgy technology, and in particular to a hydrogen metallurgy method, system and application using steel plant gas. Background Technology

[0002] Hydrogen metallurgy reduces carbon emissions at the source by using hydrogen to replace carbon in the reduction process of metallurgical materials. Hydrogen metallurgy mainly consists of two technologies: hydrogen-rich blast furnaces and hydrogen-based shaft furnaces. Hydrogen-rich blast furnaces inject hydrogen-rich gas (hydrogen, coke oven gas, natural gas, syngas, etc.) into the hearth or furnace body through the tuyeres, replacing part of the CO reduction and thus reducing carbon emissions. Hydrogen-based shaft furnaces have a hydrogen volume fraction exceeding 55% in their reducing gas, and it is hoped that full hydrogen reduction can be achieved in the future. The main processes for hydrogen-based shaft furnaces are MIDREX and HYL-ZR, and these two processes account for more than 70% of the global direct reduced iron production.

[0003] The reducing gas in the MIDREX process is produced by catalytic reforming of natural gas and recycled top gas, requiring an additional reformer as the reaction vessel. The reducing gas in the HYL-ZR process is produced by in-situ reforming of natural gas and steam in a vertical shaft furnace under the catalytic action of hot sponge iron, eliminating the need for an additional reformer. However, it requires increasing the temperature and pressure of the feed gas to improve the thermodynamic and kinetic conditions of the reaction, placing higher demands on the equipment.

[0004] Steel companies generate a large amount of by-product gas annually, including coke oven gas and converter gas, which has a high calorific value (low calorific value exceeding 4000 kcal / m³). 3 and 1500kCal / m 3 In 2022, China's coke oven gas production was approximately 190 billion cubic meters. 3 The converter gas production is approximately 78.1 billion m³. 3 Over 80% of these secondary energy sources are used as fuel or for power generation. Coke oven gas contains over 50% H2 and 20% CH4. H2 can be used as a reducing gas in hydrogen-based shaft furnaces, and CH4 can be used as injection gas in hydrogen-rich blast furnaces. When injecting CH4 into the blast furnace, oxygen enrichment is required to control the furnace temperature. Converter gas contains over 50% CO and can be used as supplementary gas for reduction in hydrogen-based shaft furnaces. The exothermic reaction of CO reduction can compensate for the heat absorbed by H2 reduction and can also be used as a carburizing agent to increase the carbon content of sponge iron. COREX, as a molten reduction ironmaking process, has been successfully applied in countries such as China, South Africa, and India. COREX gas is the gas discharged from the top of the COREX shaft furnace, containing CO and H2 (over 50%). Due to oxygen enrichment, its N2 content is low, and after decarburization, it can be used as supplementary gas for reduction in hydrogen-based shaft furnaces.

[0005] If the reducing gases from coke oven gas, converter gas, and COREX gas can be used in hydrogen-based shaft furnace smelting, it would not only absorb a large amount of secondary energy generated by steel plants (especially those with COREX units), but also reduce the equipment investment required for the conversion and reforming stages to produce reducing gas, thus simplifying the hydrogen-based shaft furnace process. Furthermore, if methane from coke oven gas could be injected into the blast furnace for low-carbon smelting, the coke ratio in the blast furnace could be reduced, thus decreasing carbon emissions.

[0006] Therefore, it is necessary to develop a hydrogen metallurgical method and system that utilizes steel plant gas to provide important technical support for recovering secondary energy from steel plants, reducing primary energy consumption in hydrogen-based shaft furnaces, and reducing carbon emissions from ironmaking processes. Summary of the Invention

[0007] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a hydrogen metallurgical method using steel plant gas, which reduces the equipment investment required for the conversion and reforming process to prepare reducing gas, reduces carbon emissions from hydrogen-based shaft furnaces and hydrogen-rich blast furnaces, and also provides a hydrogen metallurgical system that is conversion-free, highly efficient in reduction, and carburizing.

[0008] To achieve the above and other related objectives, the first aspect of the present invention provides a hydrogen metallurgical method utilizing steel plant gas, comprising:

[0009] Hydrogen extraction is performed on coke oven gas to obtain hydrogen and a first desorbed gas. The first desorbed gas is then injected into a blast furnace for low-carbon smelting to produce molten iron.

[0010] The converter gas is decarbonized to obtain converter decarbonized gas and second desorption gas;

[0011] A portion of the top gas from the hydrogen-based vertical shaft furnace is subjected to decarbonization and denitrification treatment to obtain reusable gas and third desorption gas;

[0012] A portion of the COREX gas is decarbonized to obtain COREX decarbonized gas and fourth desorption gas.

[0013] The hydrogen, recycled gas, and COREX decarburization gas are mixed together to form a hydrogen-based vertical shaft furnace reducing gas for the production of sponge iron; or, the hydrogen, recycled gas, converter decarburization gas, and COREX decarburization gas are mixed together to form a hydrogen-based vertical shaft furnace reducing gas for the production of sponge iron.

[0014] Furthermore, the second desorbed gas is delivered to the steel plant's gas pipeline network.

[0015] Furthermore, a portion of the third desorbed gas is used as fuel gas (i.e., second fuel gas) to heat the reducing gas of the hydrogen-based vertical furnace.

[0016] Furthermore, another portion of the third desorbed gas is delivered to the steel plant's gas pipeline network.

[0017] Furthermore, the fourth desorbed gas is transported to the steelmaking workshop for CO2 steelmaking.

[0018] Furthermore, another portion of the hydrogen-based vertical shaft furnace top gas is used as fuel gas for heating the hydrogen-based vertical shaft furnace reducing gas (i.e., the first fuel gas); preferably, the other portion of the hydrogen-based vertical shaft furnace top gas used as fuel gas for heating the hydrogen-based vertical shaft furnace reducing gas accounts for 4.7 to 29.8% of the total volume of the hydrogen-based vertical shaft furnace top gas.

[0019] Furthermore, in the fuel gas, the volume percentage of the third desorbed gas is ≤25% (i.e., the amount of the second fuel gas used), and the volume percentage of the other part of the hydrogen-based vertical shaft furnace top gas is ≥75% (i.e., the amount of the first fuel gas used).

[0020] Furthermore, the method also includes purifying the coke oven gas before hydrogen extraction.

[0021] Furthermore, the method also includes purifying the converter gas before decarbonizing it.

[0022] Furthermore, the method further includes: performing dust removal treatment on a portion of the hydrogen-based vertical shaft furnace top gas before decarbonizing and denitrifying it, and on another portion of the hydrogen-based vertical shaft furnace top gas before using it as fuel gas for heating the hydrogen-based vertical shaft furnace reducing gas; preferably, the dust removal treatment of the hydrogen-based vertical shaft furnace top gas includes coarse dust removal and dry dust removal; more preferably, the dust content of the hydrogen-based vertical shaft furnace top gas after coarse dust removal is ≤6g / Nm³. 3 The dust content in the top gas of the hydrogen-based vertical shaft furnace after dry dust removal is ≤5mg / Nm³. 3 .

[0023] Furthermore, the method further includes: performing dust removal treatment on a portion of the COREX gas before decarbonization; preferably, the dust removal treatment of the COREX gas includes coarse dust removal and wet dust removal; more preferably, the dust content of the COREX gas after coarse dust removal is ≤6g / Nm³. 3 The dust content of COREX gas after wet dust removal is ≤5mg / Nm³. 3 .

[0024] Furthermore, the method further includes: pressurizing the coke oven gas before hydrogen extraction treatment; preferably, the pressurized coke oven gas has a pressure of 0.45 to 0.55 MPa, and the hydrogen obtained after hydrogen extraction treatment of the coke oven gas has a pressure of 0.4 to 0.5 MPa.

[0025] Furthermore, the method further includes: pressurizing the first desorbed gas before injecting it into the blast furnace for low-carbon smelting; preferably, the pressurized gas pressure of the first desorbed gas is 0.3 to 0.4 MPa.

[0026] Furthermore, the method further includes: pressurizing the converter gas before decarbonizing it; preferably, the pressurized converter gas has a pressure of 0.45 to 0.55 MPa, and the decarbonized converter gas obtained after decarbonization has a pressure of 0.4 to 0.5 MPa.

[0027] Furthermore, the method further includes: pressurizing a portion of the hydrogen-based vertical shaft furnace top gas before decarbonizing and denitrifying it; preferably, the pressurized gas pressure of the hydrogen-based vertical shaft furnace top gas is 0.45-0.55 MPa, and the pressure of the recycled gas obtained after decarbonizing and denitrifying the portion of the hydrogen-based vertical shaft furnace top gas is 0.4-0.5 MPa.

[0028] Furthermore, the method further includes: pressurizing a portion of the COREX gas before decarbonizing it; preferably, the pressurized COREX gas has a pressure of 0.45 to 0.55 MPa, and the COREX decarbonized gas obtained after decarbonizing the portion of the COREX gas has a pressure of 0.4 to 0.5 MPa.

[0029] Furthermore, the method further includes: performing heat exchange treatment on a portion of the hydrogen-based vertical shaft furnace top gas before decarbonizing and denitrifying it, and on another portion of the hydrogen-based vertical shaft furnace top gas before using it as fuel gas to heat the hydrogen-based vertical shaft furnace reducing gas; preferably, the heat exchange treatment includes: reducing the temperature of the hydrogen-based vertical shaft furnace top gas to 40°C or below through heat exchange; more preferably, the heat exchange includes multi-stage heat exchange, comprising primary heat exchange and secondary heat exchange, the primary heat exchange including: exchanging heat between the hydrogen-based vertical shaft furnace top gas and the recycled gas, the secondary heat exchange including: exchanging heat between the hydrogen-based vertical shaft furnace top gas after primary heat exchange and a coolant, so as to reduce the temperature of the hydrogen-based vertical shaft furnace top gas to 40°C or below; most preferably, after the hydrogen-based vertical shaft furnace top gas exchanges heats with the recycled gas, the temperature of the recycled gas rises to 315–439°C. The coolant can be cooling water.

[0030] Furthermore, the method further includes: before mixing the hydrogen and recycled gas, and mixing them with the converter decarburization gas and / or COREX decarburization gas to form a hydrogen-based vertical shaft furnace reducing gas for the production of sponge iron, heating the hydrogen, recycled gas, converter decarburization gas and COREX decarburization gas; preferably, the temperature of the hydrogen, recycled gas, converter decarburization gas and COREX decarburization gas after heating is 950-1050°C.

[0031] Furthermore, the hydrogen content of the reducing gas in the hydrogen-based shaft furnace is 55-95.5%, and the H2 / CO ratio is ≥2.5. When the output of the hydrogen-based shaft furnace is 1 million tons of sponge iron per year, the reducing gas flow rate of the hydrogen-based shaft furnace is 269,000-317,000 Nm³. 3 The furnace operates at a pressure of 0.3–0.4 MPa and a temperature of 950–1050 °C. The metallization rate of the sponge iron in the hydrogen-based vertical furnace is 93–95%, and the carbon content is 0.2–3.4%.

[0032] Furthermore, when the output of the hydrogen-based shaft furnace is 1 million tons of sponge iron per year, the coke oven gas volume is 114,000–196,000 Nm³. 3 The gas is supplied at a rate of 20–50°C per hour, with a pressurized gas pressure of 0.45–0.55 MPa. After hydrogen extraction, the resulting hydrogen has a calorific value of 60–70% of the coke oven gas's calorific value, and a flow rate of 54200–93000 Nm³. 3 / h, gas pressure is 0.4~0.5MPa, and the temperature after heating is 950~1050℃.

[0033] Furthermore, when the output of the hydrogen-based shaft furnace is 1 million tons of sponge iron per year, the coke oven gas volume is 114,000–196,000 Nm³. 3 The gas is supplied at a rate of 20–50°C per hour, with a pressurized gas pressure of 0.45–0.55 MPa. After hydrogen extraction, the resulting hydrogen has a calorific value of 60–70% of the coke oven gas's calorific value, and a flow rate of 54200–93000 Nm³. 3 The gas flow rate is 0.4–0.5 MPa, and the temperature after heating is 950–1050 °C; the calorific value of the resulting first desorbed gas is 1.15–1.45 times that of the coke oven gas, and the gas volume is 60200–104000 Nm³. 3 / h, the temperature is 20~50℃; after the first desorbed gas is pressurized, it is injected into the blast furnace through the tuyeres for low-carbon smelting, and oxygen enrichment is carried out at the same time as the injection, with an oxygen enrichment rate of 25~58%, the coke ratio of the blast furnace is reduced by 45~78kg / tHM, and the CO2 emission is reduced by 12~20.8%; preferably, the pressure of the first desorbed gas after pressurization is 0.3~0.4MPa.

[0034] Furthermore, when the output of the hydrogen-based shaft furnace is 1 million tons of sponge iron per year, the flow rate of the converter gas is 7200-100000 Nm³. 3 The flow rate is 20–50°C; after decarbonization treatment, the calorific value of the decarbonized converter gas is 1.05–1.25 times that of the converter gas, and the gas volume is 5700–79000 Nm³. 3The gas pressure is 0.4–0.5 MPa, and the temperature after heating is 950–1050 °C; furthermore, the calorific value of the obtained second desorbed gas is 35–40% of the calorific value of the converter gas, and the gas volume is 1500–21200 Nm³. 3 / h, temperature is 20~50℃.

[0035] Furthermore, when the output of the hydrogen-based shaft furnace is 1 million tons of sponge iron per year, the hydrogen content of the top gas of the hydrogen-based shaft furnace is 38-72%, the CO content is 0.9-17.6%, and the gas volume is 271,000-319,000 Nm³. 3 The gas flow rate is 136,000-181,000 Nm³ / h, with a pressure of 0.16-0.26 MPa and a temperature of 410-534 °C. After decarbonization and denitrification treatment, the calorific value of the recycled gas obtained from the portion of the hydrogen-based vertical shaft furnace top gas is 1.32-1.38 times that of the portion of the hydrogen-based vertical shaft furnace top gas, and the gas flow rate is 136,000-181,000 Nm³. 3 The gas pressure is 0.4–0.5 MPa, and the temperature after heating is 950–1050 °C; furthermore, the calorific value of the obtained third desorbed gas is 70.2–95.3% of the calorific value of the top gas of the aforementioned hydrogen-based vertical shaft furnace, and the gas volume is 8400–60500 Nm³. 3 / h, temperature is 20~50℃.

[0036] Furthermore, when the output of the hydrogen-based shaft furnace is 1 million tons of sponge iron per year, the volume of the portion of COREX gas is 5970–123900 Nm³. 3 The gas flow rate is 20–50°C; after decarbonization treatment, the calorific value of the resulting decarbonized COREX gas is 1.45–1.55 times that of the original COREX gas, and the gas volume is 4000–83000 Nm³. 3 The gas pressure is 0.4–0.5 MPa, and the temperature after heating is 950–1050 °C; furthermore, the calorific value of the obtained fourth desorbed gas is 18–19% of the calorific value of the aforementioned portion of the COREX gas, and the gas volume is 1970–41000 Nm³. 3 / h, temperature is 20~50℃.

[0037] It should be noted that the hourly gas volume mentioned in this invention is set for a production capacity of 1 million tons of sponge iron per year. When the annual production of sponge iron changes, the gas volume also needs to be adjusted accordingly.

[0038] A second aspect of the present invention provides a hydrogen metallurgical system utilizing steel plant gas, the system comprising a coke oven gas treatment unit, a hydrogen-based vertical shaft furnace top gas recycling unit, a heating furnace, a hydrogen-based vertical shaft furnace, and a blast furnace;

[0039] The system further includes a COREX gas processing unit, or the system further includes a converter gas processing unit and a COREX gas processing unit;

[0040] The coke oven gas treatment unit includes a hydrogen extraction device, which is used to extract hydrogen from coke oven gas, divide the coke oven gas into hydrogen and a first desorbed gas, and is provided with a hydrogen outlet end and a first desorbed gas outlet end, the hydrogen outlet end being connected to the heating furnace.

[0041] The converter gas treatment unit includes a first decarbonization device, which is used to decarbonize the converter gas, divide the converter gas into converter decarbonized gas and second desorbed gas, and is provided with a converter decarbonized gas outlet end, which is connected to the heating furnace.

[0042] The hydrogen-based vertical furnace top gas recycling unit includes a decarbonization and denitrification device, which is used to remove CO2 and N2 from the hydrogen-based vertical furnace top gas, divides the hydrogen-based vertical furnace top gas into reusable gas and third desorption gas, and is provided with a reusable gas outlet end, which is connected to the heating furnace.

[0043] The COREX gas treatment unit includes a second decarbonization device, which is used to decarbonize the COREX gas, divide the COREX gas into COREX decarbonized gas and a fourth desorption gas, and is provided with a COREX decarbonized gas outlet end, which is connected to the heating furnace.

[0044] The heating furnace is used to heat hydrogen, converter decarburization gas, recycled gas, and COREX decarburization gas. The hydrogen and recycled gas are mixed with the converter decarburization gas and / or COREX decarburization gas in the heating furnace to form hydrogen-based vertical furnace reducing gas. The heating furnace is provided with a hydrogen-based vertical furnace reducing gas outlet end, which is connected to the hydrogen-based vertical furnace. The hydrogen-based vertical furnace uses the hydrogen-based vertical furnace reducing gas to produce sponge iron.

[0045] The first desorbed gas outlet is connected to the blast furnace, which uses the first desorbed gas for low-carbon smelting to produce molten iron.

[0046] Furthermore, the system also includes a gas pipeline network, and the first decarbonization device is also provided with a second desorption gas outlet end, which is connected to the gas pipeline network to send the second desorption gas into the gas pipeline network.

[0047] Furthermore, the decarbonization and denitrification device is also provided with a third desorption gas outlet end, and the heating furnace is provided with a second fuel gas inlet end. The third desorption gas outlet end is connected to the second fuel gas inlet end so as to send the third desorption gas into the heating furnace as fuel gas for heating.

[0048] Furthermore, the third desorption gas outlet is also connected to the gas pipeline network to deliver the third desorption gas into the gas pipeline network.

[0049] Furthermore, the system also includes a steelmaking workshop, and the second decarburization device is further provided with a fourth desorption gas outlet, which is connected to the steelmaking workshop to send the fourth desorption gas into the steelmaking workshop for CO2 steelmaking.

[0050] Furthermore, the coke oven gas treatment unit also includes a first purification device, which is located before the hydrogen extraction device and is used to purify the coke oven gas.

[0051] Furthermore, the converter gas treatment unit also includes a second purification device, which is installed before the first decarbonization device and is used to purify the converter gas.

[0052] Furthermore, the hydrogen-based vertical shaft furnace top gas recycling unit also includes a first dust removal device, which is used to remove dust from the hydrogen-based vertical shaft furnace top gas; preferably, the first dust removal device includes a first coarse dust collector and a dry dust collector connected in sequence, the first coarse dust collector is used to perform coarse dust removal on the vertical shaft furnace top gas, and the dry dust collector is used to perform dry dust removal on the vertical shaft furnace top gas after coarse dust removal.

[0053] Furthermore, the COREX gas treatment unit also includes a second dust removal device, which is located before the second decarbonization device and is used to remove dust from the COREX gas; preferably, the second dust removal device includes a second coarse dust collector and a wet dust collector, the second coarse dust collector is used to perform coarse dust removal on the COREX gas, and the wet dust collector is used to perform wet dust removal on the COREX gas.

[0054] Furthermore, the coke oven gas treatment unit also includes a first compressor, which is used to pressurize the coke oven gas; preferably, the first compressor is located between the first purification device and the hydrogen extraction device.

[0055] Furthermore, the coke oven gas treatment unit also includes a fourth compressor, which is located between the hydrogen extraction device and the blast furnace and is used to pressurize the first desorbed gas.

[0056] Furthermore, the converter gas treatment unit also includes a second compressor, which is used to pressurize the purified converter gas; preferably, the second compressor is disposed between the second purification device and the first decarbonization device.

[0057] Furthermore, the hydrogen-based vertical shaft furnace top gas recycling unit also includes a third pressurizer, which is used to pressurize the hydrogen-based vertical shaft furnace top gas after heat exchange; preferably, the third pressurizer is arranged between the first dust removal device and the decarbonization and denitrification device.

[0058] Furthermore, the COREX gas treatment unit also includes a fifth compressor, which is used to pressurize the COREX gas after dust removal; preferably, the fifth compressor is located between the second dust removal device and the second decarbonization device.

[0059] Furthermore, the hydrogen-based vertical shaft furnace top gas recycling unit also includes a heat exchange device for heat exchange treatment of the hydrogen-based vertical shaft furnace top gas. Preferably, the heat exchange device is located between the first dust removal device and the third compressor. The heat exchange device includes a multi-stage heat exchanger, which includes a primary heat exchanger and a secondary heat exchanger connected in sequence. The primary heat exchanger is connected to the recycled gas outlet and serves as the site for heat exchange between the recycled gas and the hydrogen-based vertical shaft furnace top gas. The secondary heat exchanger serves as the site for heat exchange between the coolant and the hydrogen-based vertical shaft furnace top gas.

[0060] Furthermore, the heating furnace is also provided with a first fuel gas inlet, which is the inlet for feeding the top gas of the hydrogen-based vertical furnace into the heating furnace, so as to feed the top gas of the hydrogen-based vertical furnace into the heating furnace as fuel gas for heating; preferably, the first fuel gas inlet is connected to the outlet end of the hydrogen-based vertical furnace top gas of the heat exchange device, so as to feed part of the top gas of the hydrogen-based vertical furnace after heat exchange into the heating furnace as fuel gas for heating.

[0061] A third aspect of the present invention provides the method according to the first aspect and / or the system according to the second aspect in the field of hydrogen metallurgy and their application.

[0062] As described above, the hydrogen metallurgical method, system, and application of the present invention utilizing steel plant gas have the following beneficial effects:

[0063] 1) This invention extracts and utilizes H2 from coke oven gas, CO from converter gas, and CO from hydrogen- and oxygen-enriched COREX gas as reducing gas. This not only makes full use of the steel plant's secondary energy reduction capacity, but also uses a mature and simple gas removal device to replace the reforming converter, which has a higher investment cost, thus reducing the primary energy consumption and equipment investment of the hydrogen-based vertical shaft furnace.

[0064] 2) In the method of the present invention, the volume fraction of H2 in the hydrogen-based vertical furnace reducing gas is 55-95.5%, and the temperature is controlled at 950-1050℃, which ensures a high reduction capacity; the volume fraction of CO is 1.2-24%, which can effectively achieve a carburization amount of 0.2-3.4% in sponge iron.

[0065] 3) This invention injects the methane-rich desorbed gas (i.e., the first desorbed gas) after hydrogen extraction from coke oven gas into the blast furnace, while simultaneously performing oxygen enrichment operations. This can reduce the coke ratio of the blast furnace and decrease CO2 emissions from the combined steel plant while maintaining the original blast furnace belly gas volume and theoretical combustion temperature basically unchanged.

[0066] In summary, the technology provided by this invention offers a low-carbon and efficient new method for hydrogen metallurgy that utilizes secondary energy from steel plants and avoids the technical problems of high-investment reforming and conversion. This method is of great significance for simplifying the process flow of hydrogen-based vertical shaft furnaces and reducing carbon emissions from blast furnaces. Attached Figure Description

[0067] Figure 1 The diagram shows the layout of a hydrogen metallurgical system utilizing steel plant gas in one embodiment and Examples 1-8 of the present invention.

[0068] Figure 2 The diagram shows the layout of a hydrogen metallurgical system utilizing steel plant gas in another embodiment and Examples 9-11 of the present invention.

[0069] Figure 3 The diagram shows the layout of a hydrogen metallurgical system utilizing steel plant gas in another embodiment and Example 12 of the present invention.

[0070] Explanation of reference numerals in the attached figures:

[0071] First press 11, hydrogen extraction unit 12, fourth press 13, second press 21, first decarbonization unit 22, first coarse dust collector 31, dry dust collector 32, heat exchange unit 33, third press 34, decarbonization and denitrification unit 35, second coarse dust collector 41, wet dust collector 42, fifth press 43, second decarbonization unit 44, heating furnace 50, hydrogen-based vertical shaft furnace 60, blast furnace 70, gas pipeline network 80, steelmaking workshop 90, COREX system 100. Detailed Implementation

[0072] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0073] In the accompanying drawings of the embodiments of the present invention, the same or similar reference numerals correspond to the same or similar components. In the description of the present invention, it should be understood that if terms such as "upper," "lower," "left," "right," "front," and "rear" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting the present invention. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0074] One embodiment of the present invention provides a hydrogen metallurgical method using steel plant gas, comprising the following steps:

[0075] Hydrogen extraction is performed on coke oven gas to obtain hydrogen and a first desorbed gas. The first desorbed gas is then injected into a blast furnace for low-carbon smelting to produce molten iron.

[0076] The converter gas is decarbonized to obtain converter decarbonized gas and second desorption gas;

[0077] A portion of the top gas from the hydrogen-based vertical shaft furnace is subjected to decarbonization and denitrification treatment to obtain reusable gas and third desorption gas;

[0078] A portion of the COREX gas is decarbonized to obtain COREX decarbonized gas and fourth desorption gas.

[0079] The hydrogen and recycled gas are mixed together, and then mixed with the converter decarburization gas and / or COREX decarburization gas to form a hydrogen-based vertical shaft furnace reducing gas for the production of sponge iron.

[0080] Specifically, "the hydrogen and recycled gas are mixed, and then mixed with the converter decarbonization gas and / or COREX decarbonization gas to form a hydrogen-based vertical shaft furnace reducing gas." The composition of the hydrogen-based vertical shaft furnace reducing gas includes the following three methods:

[0081] 1. The reducing gas for the hydrogen-based vertical shaft furnace is composed of a mixture of hydrogen, recycled gas, and converter decarburization gas;

[0082] 2. The reducing gas for the hydrogen-based vertical shaft furnace is composed of a mixture of hydrogen, recycled gas, and COREX decarbonization gas;

[0083] 3. The hydrogen-based vertical shaft furnace reducing gas is composed of a mixture of hydrogen, recycled gas, converter decarburization gas, and COREX decarburization gas.

[0084] The method described above extracts and utilizes H2 from coke oven gas, CO from converter gas, and CO and H2 from COREX gas as reducing gases. This fully utilizes the reducing capacity of the steel plant's secondary energy source and replaces the more expensive reforming converter with a mature and simple gas removal device, reducing the primary energy consumption and equipment investment of the hydrogen-based vertical shaft furnace. By injecting the methane-rich desorbed gas (i.e., the first desorbed gas) after hydrogen extraction from coke oven gas into the blast furnace and simultaneously performing oxygen enrichment, the coke ratio of the blast furnace can be reduced while maintaining the original blast furnace belly gas volume and theoretical combustion temperature basically unchanged, thereby reducing CO2 emissions from the combined steel plant.

[0085] In another embodiment of the present invention, the second desorbed gas is transported to the steel plant gas pipeline network to achieve full utilization of converter gas.

[0086] In another embodiment of the present invention, a portion of the third desorbed gas is used as fuel gas (i.e., second fuel gas) for heating the reducing gas of the hydrogen-based vertical furnace.

[0087] In another embodiment of the present invention, another portion of the third desorbed gas is delivered to the steel plant's gas pipeline network.

[0088] The above implementation method divides the third desorption gas into two parts for use, thereby achieving full utilization of the top gas of the hydrogen-based vertical shaft furnace.

[0089] In another embodiment of the present invention, the fourth desorbed gas is transported to the steelmaking workshop for CO2 steelmaking, thereby realizing the full utilization of COREX gas.

[0090] In another embodiment of the present invention, another portion of the hydrogen-based vertical furnace top gas is used as fuel gas for heating the hydrogen-based vertical furnace reducing gas (i.e., the first fuel gas); preferably, the other portion of the hydrogen-based vertical furnace top gas used as fuel gas for heating the hydrogen-based vertical furnace reducing gas accounts for 4.7 to 29.8% of the total volume of the hydrogen-based vertical furnace top gas.

[0091] In one specific embodiment, the volume fraction of the third desorbed gas in the fuel gas is ≤25% (i.e., the amount of the second fuel gas used), and the volume fraction of the other part of the hydrogen-based vertical shaft furnace top gas is ≥75% (i.e., the amount of the first fuel gas used).

[0092] The above-described embodiment uses the third desorbed gas and a portion of the hydrogen-based vertical shaft furnace top gas as fuel gas to heat the hydrogen-based vertical shaft furnace reducing gas, thus eliminating the need for external fuel and achieving self-sufficiency. It should be noted that the second fuel gas is an optional fuel gas or can be considered as supplementary fuel gas. When the first fuel gas is insufficient, a portion of the third desorbed gas can be selected as supplementary fuel gas for heating the hydrogen-based vertical shaft furnace reducing gas.

[0093] In another embodiment of the present invention, the method further includes purifying the coke oven gas before hydrogen extraction.

[0094] In another embodiment of the present invention, the method further includes purifying the converter gas before decarbonizing it.

[0095] The purification treatment in the above embodiments refers to desulfurization purification treatment, that is, removing organic and inorganic sulfur from the coal gas. Preferably, the total sulfur content of the coke oven / converter gas after desulfurization treatment is ≤10mg / m³. 3 .

[0096] In another embodiment of the present invention, the method further includes: performing dust removal treatment on a portion of the hydrogen-based vertical shaft furnace top gas before decarbonizing and denitrifying it, and before using another portion of the hydrogen-based vertical shaft furnace top gas as fuel gas for heating the hydrogen-based vertical shaft furnace reducing gas; preferably, the dust removal treatment of the hydrogen-based vertical shaft furnace top gas includes coarse dust removal and dry dust removal; more preferably, the dust content of the hydrogen-based vertical shaft furnace top gas after coarse dust removal is ≤6g / Nm³. 3 The dust content in the top gas of the hydrogen-based vertical shaft furnace after dry dust removal is ≤5mg / Nm³. 3 .

[0097] In another embodiment of the present invention, the method further includes: performing dust removal treatment on a portion of the COREX gas before decarbonization; preferably, the dust removal treatment of the COREX gas includes coarse dust removal and wet dust removal; more preferably, the dust content of the COREX gas after coarse dust removal is ≤6g / Nm³. 3 The dust content of COREX gas after wet dust removal is ≤5mg / Nm³. 3 .

[0098] In another embodiment of the present invention, the method further includes: pressurizing the coke oven gas after purification treatment and before hydrogen extraction treatment; preferably, the pressurized coke oven gas has a pressure of 0.45 to 0.55 MPa, and the hydrogen obtained after hydrogen extraction treatment has a pressure of 0.4 to 0.5 MPa.

[0099] In another embodiment of the present invention, the method further includes: pressurizing the first desorbed gas before injecting it into the blast furnace for low-carbon smelting; preferably, the pressurized gas pressure of the first desorbed gas is 0.3 to 0.4 MPa.

[0100] In another embodiment of the present invention, the method further includes: pressurizing the converter gas after purification treatment and before decarbonization treatment; preferably, the pressurized converter gas has a pressure of 0.45 to 0.55 MPa, and the decarbonized converter gas obtained after decarbonization treatment has a pressure of 0.4 to 0.5 MPa.

[0101] In another embodiment of the present invention, the method further includes: pressurizing a portion of the hydrogen-based vertical shaft furnace top gas before decarbonizing and denitrifying it; preferably, the pressurized gas pressure of the hydrogen-based vertical shaft furnace top gas is 0.45-0.55 MPa, and the pressure of the recycled gas obtained after decarbonizing and denitrifying the portion of the hydrogen-based vertical shaft furnace top gas is 0.4-0.5 MPa.

[0102] In another embodiment of the present invention, the method further includes: pressurizing a portion of the COREX gas after dust removal and before decarbonization treatment of the remaining portion of the COREX gas; preferably, the pressurized COREX gas has a pressure of 0.45 to 0.55 MPa, and the COREX decarbonized gas obtained after decarbonization treatment of the remaining portion of the COREX gas has a pressure of 0.4 to 0.5 MPa.

[0103] In another embodiment of the present invention, the method further includes: after dust removal from the top gas of the hydrogen-based vertical shaft furnace, before pressurizing and decarbonizing / denitrifying a portion of the top gas of the hydrogen-based vertical shaft furnace, and before using another portion of the top gas of the hydrogen-based vertical shaft furnace as fuel gas for heating the reducing gas of the hydrogen-based vertical shaft furnace, performing heat exchange treatment on it; preferably, the heat exchange treatment includes: reducing the temperature of the top gas of the hydrogen-based vertical shaft furnace to 40°C or below through heat exchange; more preferably, the heat exchange includes multi-stage heat exchange, the multi-stage heat exchange includes primary heat exchange and secondary heat exchange, the primary heat exchange includes: exchanging heat between the top gas of the hydrogen-based vertical shaft furnace and the recycled gas, the secondary heat exchange includes: exchanging heat between the top gas of the hydrogen-based vertical shaft furnace after primary heat exchange and the coolant, so that the temperature of the top gas of the hydrogen-based vertical shaft furnace is reduced to 40°C or below; most preferably, after the top gas of the hydrogen-based vertical shaft furnace and the recycled gas undergo heat exchange, the temperature of the recycled gas rises to 315-439°C. Cooling water can be used as the coolant.

[0104] The above-described embodiments reduce the temperature of the top gas of the hydrogen-based vertical shaft furnace through heat exchange, thereby facilitating decarbonization and denitrification. By exchanging heat between the recycled gas and the top gas of the hydrogen-based vertical shaft furnace, the residual heat of the top gas is fully utilized to increase the temperature of the recycled gas, which can reduce the demand for fuel gas in the heating process. In addition, in order to avoid the excessively high temperature of the top gas of the hydrogen-based vertical shaft furnace after heat exchange with the recycled gas from adversely affecting decarbonization and denitrification, a secondary heat exchange with coolant can be used to control the temperature of the top gas of the hydrogen-based vertical shaft furnace after heat exchange at 40°C or below.

[0105] In another embodiment of the present invention, the method further includes: before mixing the hydrogen and recycled gas, and mixing them with the converter decarburization gas and / or COREX decarburization gas to form a hydrogen-based vertical shaft furnace reducing gas for the production of sponge iron, heating the hydrogen, recycled gas, converter decarburization gas and COREX decarburization gas; preferably, the temperature of the hydrogen, recycled gas, converter decarburization gas and COREX decarburization gas after heating is 950-1050°C.

[0106] In another embodiment of the present invention, the hydrogen content of the reducing gas in the hydrogen-based shaft furnace is 55-95.5%, the H2 / CO ratio is ≥2.5, and when the output of the hydrogen-based shaft furnace is 1 million tons of sponge iron / year, the reducing gas flow rate of the hydrogen-based shaft furnace is 269,000-317,000 Nm³. 3 The furnace operates at a pressure of 0.3–0.4 MPa and a temperature of 950–1050 °C. The metallization rate of the sponge iron in the hydrogen-based vertical furnace is 93–95%, and the carbon content is 0.2–3.4%.

[0107] In the above embodiments, the volume fraction of H2 in the reducing gas of the hydrogen-based vertical furnace is controlled at 55-96.5%, and the temperature is controlled at 950-1050℃, thus ensuring a high reduction capacity; the volume fraction of CO is controlled at 1.2-24%, which can effectively achieve a carburization amount of 0.2-3.4% for sponge iron.

[0108] To achieve the aforementioned technical effects, in one specific embodiment, when the output of the hydrogen-based shaft furnace is 1 million tons of sponge iron per year, the gas volume of the coke oven gas is 114,000–196,000 Nm³. 3 The gas is supplied at a rate of 20–50°C per hour, with a pressurized gas pressure of 0.45–0.55 MPa. After hydrogen extraction, the resulting hydrogen has a calorific value of 60–70% of the coke oven gas's calorific value, and a flow rate of 54200–93000 Nm³. 3 The gas flow rate is 0.4–0.5 MPa, and the temperature after heating is 950–1050 °C; the calorific value of the resulting first desorbed gas is 1.15–1.45 times that of the coke oven gas, and the gas volume is 60200–104000 Nm³. 3 / h, the temperature is 20~50℃; after the first desorbed gas is pressurized, it is injected into the blast furnace through the tuyeres for low-carbon smelting, and oxygen enrichment is carried out at the same time as the injection, with an oxygen enrichment rate of 25~58%, the coke ratio of the blast furnace is reduced by 45~78kg / tHM, and the CO2 emission is reduced by 12~20.8%; preferably, the pressure of the first desorbed gas after pressurization is 0.3~0.4MPa.

[0109] In one specific embodiment, when the output of the hydrogen-based shaft furnace is 1 million tons of sponge iron per year, the converter gas flow rate is 7200-100000 Nm³. 3 The flow rate is 20–50°C; after decarbonization treatment, the calorific value of the decarbonized converter gas is 1.05–1.25 times that of the converter gas, and the gas volume is 5700–79000 Nm³. 3 The gas pressure is 0.4–0.5 MPa, and the temperature after heating is 950–1050 °C; the calorific value of the resulting second desorbed gas is 35–40% of the calorific value of the converter gas, and the gas volume is 1500–21200 Nm³. 3 / h, temperature is 20~50℃, and air pressure is 0.02MPa.

[0110] In one specific embodiment, when the output of the hydrogen-based shaft furnace is 1 million tons of sponge iron per year, the hydrogen content of the top gas of the hydrogen-based shaft furnace is 38-72%, the CO content is 0.9-17.6%, and the gas volume is 271,000-319,000 Nm³. 3 The gas flow rate is 136,000-181,000 Nm³ / h, with a pressure of 0.16-0.26 MPa and a temperature of 410-534 °C. After decarbonization and denitrification treatment, the calorific value of the recycled gas obtained from the portion of the hydrogen-based vertical shaft furnace top gas is 1.32-1.38 times that of the portion of the hydrogen-based vertical shaft furnace top gas, and the gas flow rate is 136,000-181,000 Nm³. 3 The gas pressure is 0.4–0.5 MPa, and the temperature after heating is 950–1050 °C; the calorific value of the resulting third desorbed gas is 70.2–95.3% of the calorific value of the top gas of the aforementioned hydrogen-based vertical shaft furnace, and the gas volume is 8400–60500 Nm³. 3 / h, temperature is 20~50℃, and air pressure is 0.02MPa.

[0111] In one specific embodiment, when the output of the hydrogen-based shaft furnace is 1 million tons of sponge iron per year, the volume of the portion of COREX gas is 5970–123900 Nm³. 3 The gas flow rate is 20–50°C; after decarbonization treatment, the calorific value of the resulting decarbonized COREX gas is 1.45–1.55 times that of the original COREX gas, and the gas volume is 4000–83000 Nm³. 3The gas pressure is 0.4–0.5 MPa, and the temperature after heating is 950–1050 °C; the calorific value of the resulting fourth desorbed gas is 18–19% of the calorific value of the aforementioned portion of the COREX gas, and the gas volume is 1970–41000 Nm³. 3 / h, temperature is 20~50℃, and air pressure is 0.02MPa.

[0112] In the above embodiments, the methods for hydrogen extraction, decarbonization, and decarbonization / denitrification can be any one or more of physical absorption, chemical absorption, and physical-chemical absorption. These methods are all prior art, and will not be described in detail here.

[0113] It should be noted that the hourly gas volume involved in the above embodiments and subsequent embodiments of the present invention is set for a production capacity of 1 million tons of sponge iron per year. When the annual production capacity of sponge iron changes, the gas volume also needs to be adjusted accordingly. Those skilled in the art can refer to the embodiments and examples of the present invention to design and adjust according to actual conditions and needs.

[0114] In addition to the COREX process, the FINEX and HIsmelt processes are also currently in commercial production for molten reduction ironmaking. FINEX has been successfully applied in Northeast Asia; the HIsmelt process was introduced to China relatively recently and is currently in the stage of digestion and absorption, with domestic ironmaking workers conducting in-depth research on it. Blast furnace top gas, FINEX gas, and HIsmelt gas, like COREX gas, also contain CO and H2, and after decarbonization, can be used as supplementary gas for hydrogen-based shaft furnace reduction. However, it should be noted that the application scenarios for COREX, FINEX, and HIsmelt processes are different, and there is currently no scenario where they coexist in a single plant. Therefore, any one of the blast furnace top gas, FINEX gas, and HIsmelt gas can be used to replace the COREX gas in the above embodiments / examples of this invention, or the blast furnace top gas can be used in combination with at least one of the COREX gas and converter gas in the above embodiments / examples of this invention, and after decarbonization treatment according to the same / similar methods in the above embodiments / examples of this invention, it can be reused.

[0115] Please refer to Figures 1 to 3 One embodiment of the present invention provides a hydrogen metallurgical system utilizing steel plant gas, including a coke oven gas treatment unit, a hydrogen-based vertical shaft furnace top gas recycling unit, a heating furnace 50, a hydrogen-based vertical shaft furnace 60, a blast furnace 70, and a COREX system 100. The system also includes a converter gas treatment unit and / or a COREX gas treatment unit.

[0116] The coke oven gas treatment unit includes a hydrogen extraction device 12, which is used to extract hydrogen from coke oven gas, divide the coke oven gas into hydrogen and a first desorbed gas, and is provided with a hydrogen outlet end and a first desorbed gas outlet end. The hydrogen outlet end is connected to the heating furnace 50.

[0117] The converter gas treatment unit includes a first decarbonization device 22, which is used to decarbonize the converter gas, divide the converter gas into converter decarbonized gas and second desorption gas, and is provided with a converter decarbonized gas outlet end, which is connected to the heating furnace 50.

[0118] The hydrogen-based vertical shaft furnace top gas recycling unit includes a decarbonization and denitrification device 35, which is used to remove CO2 and N2 from the hydrogen-based vertical shaft furnace top gas, divides the hydrogen-based vertical shaft furnace top gas into reusable gas and third desorption gas, and is provided with a reusable gas outlet end, which is connected to the heating furnace 50.

[0119] The COREX gas treatment unit includes a second decarbonization device 44, which is used to decarbonize the COREX gas. The COREX gas discharged from the COREX system 100 is divided into COREX decarbonized gas and fourth desorption gas, and is provided with a COREX decarbonized gas outlet end, which is connected to the heating furnace 50.

[0120] Heating furnace 50 is used to heat hydrogen, converter decarburization gas, recycled gas and COREX decarburization gas. The hydrogen and recycled gas are mixed with converter decarburization gas and / or COREX decarburization gas in heating furnace 50 to form hydrogen-based vertical furnace reducing gas. Heating furnace 50 is provided with hydrogen-based vertical furnace reducing gas outlet end, which is connected to hydrogen-based vertical furnace 60. Hydrogen-based vertical furnace 60 uses hydrogen-based vertical furnace reducing gas to produce sponge iron.

[0121] The first desorption gas outlet is connected to blast furnace 70, which uses the first desorption gas for low-carbon smelting to produce molten iron.

[0122] In another embodiment of the present invention, the system further includes a gas pipeline network 80, and the first decarbonization device 22 is further provided with a second desorption gas outlet end, which is connected to the gas pipeline network 80 to send the second desorption gas into the gas pipeline network 80.

[0123] In another embodiment of the present invention, the decarbonization and denitrification device 35 is further provided with a third desorption gas outlet end, and the heating furnace 50 is provided with a second fuel gas inlet end. The third desorption gas outlet end is connected to the second fuel gas inlet end so as to send the third desorption gas into the heating furnace 50 as fuel gas for heating.

[0124] In another embodiment of the present invention, the third desorption gas outlet is also connected to the gas pipeline 80 to send the third desorption gas into the gas pipeline 80.

[0125] In another embodiment of the present invention, the system further includes a steelmaking workshop 90, and the second decarburization device 44 is further provided with a fourth desorption gas outlet end, which is connected to the steelmaking workshop 90 to send the fourth desorption gas into the steelmaking workshop 90 for CO2 steelmaking.

[0126] In another embodiment of the present invention, the coke oven gas treatment unit further includes a first purification device (not shown in the figure), which is disposed before the hydrogen extraction device 12 and is used to purify the coke oven gas.

[0127] In another embodiment of the present invention, the converter gas treatment unit further includes a second purification device (not shown in the figure), which is disposed before the first decarbonization device 22 and is used to purify the converter gas.

[0128] In another embodiment of the present invention, the hydrogen-based vertical shaft furnace top gas recycling unit further includes a first dust removal device, which is disposed between the hydrogen-based vertical shaft furnace 60 and the heat exchange device 33, and is used to remove dust from the hydrogen-based vertical shaft furnace top gas; preferably, the first dust removal device includes a first coarse dust collector 31 and a dry dust collector 32 connected in sequence, the first coarse dust collector 31 is used to perform coarse dust removal on the vertical shaft furnace top gas, and the dry dust collector 32 is used to perform dry dust removal on the vertical shaft furnace top gas after coarse dust removal.

[0129] In another embodiment of the present invention, the COREX gas treatment unit further includes a second dust removal device, which is disposed before the second decarbonization device 44 and is used to perform dust removal treatment on the COREX gas; preferably, the second dust removal device includes a second coarse dust collector 41 and a wet dust collector 42 connected in sequence, the second coarse dust collector 41 is used to perform coarse dust removal on the COREX gas, and the wet dust collector 42 is used to perform wet dust removal on the COREX gas.

[0130] In another embodiment of the present invention, the coke oven gas treatment unit further includes a first pressurizer 11, which is used to pressurize the coke oven gas; preferably, the first pressurizer 11 is disposed between the first purification device and the hydrogen extraction device 12.

[0131] In another embodiment of the present invention, the coke oven gas treatment unit further includes a fourth compressor 13, which is disposed between the hydrogen extraction device 12 and the blast furnace 70, and is used to pressurize the first desorbed gas.

[0132] In another embodiment of the present invention, the converter gas treatment unit further includes a second pressurizer 21, which is used to pressurize the purified converter gas; preferably, the second pressurizer 21 is disposed between the second purification device and the second decarbonization device 44.

[0133] In another embodiment of the present invention, the hydrogen-based vertical shaft furnace top gas recycling unit further includes a third pressurizer 34, which is used to pressurize the hydrogen-based vertical shaft furnace top gas after heat exchange; preferably, the third pressurizer 34 is disposed between the first dust removal device and the decarbonization and denitrification device 35.

[0134] In another embodiment of the present invention, the COREX gas treatment unit further includes a fifth compressor 43, which is used to pressurize the dust-removed COREX gas; preferably, the fifth compressor 43 is disposed between the second dust removal device and the second decarbonization device 44.

[0135] In another embodiment of the present invention, the hydrogen-based vertical shaft furnace top gas recycling unit further includes a heat exchange device 33, which is used to perform heat exchange treatment on the hydrogen-based vertical shaft furnace top gas. Preferably, the heat exchange device 33 is disposed between the first dust removal device and the third compressor 34. The heat exchange device 33 includes a multi-stage heat exchanger, which includes a primary heat exchanger and a secondary heat exchanger connected in sequence. The primary heat exchanger is connected to the recycled gas outlet end and is the place where the recycled gas and the hydrogen-based vertical shaft furnace top gas exchange heat. The secondary heat exchanger is the place where the coolant and the hydrogen-based vertical shaft furnace top gas exchange heat.

[0136] In another embodiment of the present invention, the heating furnace 50 is further provided with a first fuel gas inlet end, which is the inlet for feeding hydrogen-based vertical furnace top gas into the heating furnace 50, so as to feed hydrogen-based vertical furnace top gas into the heating furnace 50 as fuel gas for heating; preferably, the first fuel gas inlet end is connected to the hydrogen-based vertical furnace top gas outlet end of the heat exchange device 33, so as to feed part of the hydrogen-based vertical furnace top gas after heat exchange into the heating furnace 50 as fuel gas for heating.

[0137] like Figure 1 As shown, one embodiment of the present invention provides a hydrogen metallurgical system utilizing steel plant gas, including a coke oven gas treatment unit, a converter gas treatment unit, a hydrogen-based vertical shaft furnace top gas recycling unit, a heating furnace 50, a hydrogen-based vertical shaft furnace 60, a blast furnace 70, and a gas pipeline network 80.

[0138] Specifically, the coke oven gas treatment unit includes a first purification device, a first pressurizer 11, a hydrogen extraction device 12, and a fourth pressurizer 13 connected in sequence. After being purified by the first purification device and pressurized by the first pressurizer 11, the coke oven gas enters the hydrogen extraction device 12 to extract hydrogen and is divided into hydrogen and first desorbed gas. The hydrogen extraction device 12 is provided with a hydrogen outlet end and a first desorbed gas outlet end. The hydrogen outlet end is connected to the heating furnace 50, and the first desorbed gas outlet end and the fourth pressurizer 13 are connected in sequence to the blast furnace 70. After being pressurized by the fourth pressurizer 13, the first desorbed gas is injected into the blast furnace 70 through the tuyeres for low-carbon smelting.

[0139] The converter gas treatment unit includes a second purification device, a second pressurizer 21, and a first decarbonization device 22 connected in sequence. After being purified by the second purification device and pressurized by the second pressurizer 21, the converter gas enters the first decarbonization device 22 for decarbonization and is divided into converter decarbonization gas and second desorption gas. The first decarbonization device 22 is provided with a converter decarbonization gas outlet end and a second desorption gas outlet end. The converter decarbonization gas outlet end is connected to the heating furnace 50, and the second desorption gas outlet end is connected to the gas pipeline network 80 to send the second desorption gas into the gas pipeline network 80.

[0140] The hydrogen-based vertical shaft furnace top gas recycling unit includes a first dust removal device, a heat exchange device 33, a third compressor 34, and a decarbonization and denitrification device 35, connected sequentially from the hydrogen-based vertical shaft furnace top gas outlet. The first dust removal device includes a first coarse dust collector 31 and a dry dust collector 32. After coarse and dry dust removal, the hydrogen-based vertical shaft furnace top gas first undergoes a primary heat exchange with recycled gas in the heat exchange device 33, and then undergoes a secondary heat exchange with coolant. Then, a portion of the hydrogen-based vertical shaft furnace top gas enters the third compressor 34, is pressurized, and then enters the decarbonization and denitrification device 35 for further processing. Besides CO2 and N2, the gas is divided into reclaimed gas and third desorbed gas. The decarbonization and denitrification unit 35 is equipped with a reclaimed gas outlet and a third desorbed gas outlet. The reclaimed gas outlet is connected to the heating furnace 50, and the third desorbed gas outlet is connected to the second fuel gas inlet to send the third desorbed gas into the heating furnace 50 as fuel gas for heating. The third desorbed gas outlet is also connected to the gas pipeline 80 to send the third desorbed gas into the gas pipeline 80. Another part of the hydrogen-based vertical shaft furnace top gas is directly fed into the heating furnace 50 as fuel gas after heat exchange.

[0141] The heating furnace 50 is used to heat hydrogen, converter decarburization gas and recycled gas. The hydrogen, converter decarburization gas and recycled gas are mixed in the heating furnace 50 to form hydrogen-based vertical furnace reducing gas. The heating furnace 50 is provided with a hydrogen-based vertical furnace reducing gas outlet end, which is connected to the hydrogen-based vertical furnace 60. The hydrogen-based vertical furnace 60 uses hydrogen-based vertical furnace reducing gas to produce sponge iron.

[0142] Blast Furnace 70 uses the first desorption gas for low-carbon smelting to produce liquid iron.

[0143] like Figure 2 As shown, another embodiment of the present invention provides a hydrogen metallurgical system utilizing steel plant gas, including a coke oven gas treatment unit, a hydrogen-based vertical shaft furnace top gas recycling unit, a COREX gas treatment unit, a heating furnace 50, a hydrogen-based vertical shaft furnace 60, a blast furnace 70, a gas pipeline network 80, a steelmaking workshop 90, and a COREX system 100.

[0144] Specifically, the coke oven gas treatment unit includes a first purification device, a first pressurizer 11, and a hydrogen extraction device 12 connected in sequence. After being purified by the first purification device and pressurized by the first pressurizer 11, the coke oven gas enters the hydrogen extraction device 12 to extract hydrogen and is divided into hydrogen and a first desorbed gas. The hydrogen extraction device 12 is provided with a hydrogen outlet end and a first desorbed gas outlet end, wherein the hydrogen outlet end is connected to the heating furnace 50 and the first desorbed gas outlet end is connected to the blast furnace 70.

[0145] The hydrogen-based vertical shaft furnace top gas recycling unit includes a first dust removal device, a heat exchange device 33, a third compressor 34, and a decarbonization and denitrification device 35, connected sequentially from the hydrogen-based vertical shaft furnace top gas outlet. The first dust removal device includes a first coarse dust collector 31 and a dry dust collector 32. After coarse and dry dust removal, the hydrogen-based vertical shaft furnace top gas first undergoes a primary heat exchange with recycled gas in the heat exchange device 33, and then undergoes a secondary heat exchange with coolant. Then, a portion of the hydrogen-based vertical shaft furnace top gas enters the third compressor 34, is pressurized, and then enters the decarbonization and denitrification device 35 for further processing. Besides CO2 and N2, the gas is divided into reclaimed gas and third desorbed gas. The decarbonization and denitrification unit 35 is equipped with a reclaimed gas outlet and a third desorbed gas outlet. The reclaimed gas outlet is connected to the heating furnace 50, and the third desorbed gas outlet is connected to the second fuel gas inlet to send the third desorbed gas into the heating furnace 50 as fuel gas for heating. The third desorbed gas outlet is also connected to the gas pipeline 80 to send the third desorbed gas into the gas pipeline 80. Another part of the hydrogen-based vertical shaft furnace top gas is directly fed into the heating furnace 50 as fuel gas after heat exchange.

[0146] The COREX gas treatment unit includes a second dust removal device, a fifth compressor 43, and a second decarbonization device 44 connected sequentially from the COREX gas outlet. The second dust removal device includes a first coarse dust collector 31 and a wet dust collector 42. The COREX gas discharged from the COREX system 100 is subjected to coarse dust removal, wet dust removal, and pressurization before entering the second decarbonization device 44 for decarbonization. It is divided into COREX decarbonized gas and fourth desorbed gas. The second decarbonization device 44 is provided with a COREX decarbonized gas outlet and a fourth desorbed gas outlet. The COREX decarbonized gas outlet is connected to the heating furnace 50, and the fourth desorbed gas outlet is connected to the steelmaking workshop 90 to send the fourth desorbed gas into the steelmaking workshop 90 for CO2 steelmaking.

[0147] Heating furnace 50 is used to heat hydrogen, converter decarburization gas, recycled gas and COREX decarburization gas. The hydrogen and recycled gas are mixed with converter decarburization gas and / or COREX decarburization gas in heating furnace 50 to form hydrogen-based vertical furnace reducing gas. Heating furnace 50 is provided with hydrogen-based vertical furnace reducing gas outlet end, which is connected to hydrogen-based vertical furnace 60. Hydrogen-based vertical furnace 60 uses hydrogen-based vertical furnace reducing gas to produce sponge iron.

[0148] Blast Furnace 70 uses the first desorption gas for low-carbon smelting to produce liquid iron.

[0149] like Figure 3 As shown, another embodiment of the present invention provides a hydrogen metallurgical system utilizing steel plant gas, including a coke oven gas treatment unit, a converter gas treatment unit, a hydrogen-based vertical shaft furnace top gas recycling unit, a COREX gas treatment unit, a heating furnace 50, a hydrogen-based vertical shaft furnace 60, a blast furnace 70, a gas pipeline network 80, a steelmaking workshop 90, and a COREX system 100.

[0150] Specifically, the coke oven gas treatment unit includes a first purification device, a first pressurizer 11, and a hydrogen extraction device 12 connected in sequence. After being purified by the first purification device and pressurized by the first pressurizer 11, the coke oven gas enters the hydrogen extraction device 12 to extract hydrogen and is divided into hydrogen and a first desorbed gas. The hydrogen extraction device 12 is provided with a hydrogen outlet end and a first desorbed gas outlet end, wherein the hydrogen outlet end is connected to the heating furnace 50 and the first desorbed gas outlet end is connected to the blast furnace 70.

[0151] The converter gas treatment unit includes a second purification device, a second pressurizer 21, and a first decarbonization device 22 connected in sequence. After being purified by the second purification device and pressurized by the second pressurizer 21, the converter gas enters the first decarbonization device 22 for decarbonization and is divided into converter decarbonization gas and second desorption gas. The first decarbonization device 22 is provided with a converter decarbonization gas outlet end and a second desorption gas outlet end. The converter decarbonization gas outlet end is connected to the heating furnace 50, and the second desorption gas outlet end is connected to the gas pipeline network 80 to send the second desorption gas into the gas pipeline network 80.

[0152] The hydrogen-based vertical shaft furnace top gas recycling unit includes a first dust removal device, a heat exchange device 33, a third compressor 34, and a decarbonization and denitrification device 35, connected sequentially from the hydrogen-based vertical shaft furnace top gas outlet. The first dust removal device includes a first coarse dust collector 31 and a dry dust collector 32. After coarse and dry dust removal, the hydrogen-based vertical shaft furnace top gas first undergoes a primary heat exchange with recycled gas in the heat exchange device 33, and then undergoes a secondary heat exchange with coolant. Then, a portion of the hydrogen-based vertical shaft furnace top gas enters the third compressor 34, is pressurized, and then enters the decarbonization and denitrification device 35 for further processing. Besides CO2 and N2, the gas is divided into reclaimed gas and third desorbed gas. The decarbonization and denitrification unit 35 is equipped with a reclaimed gas outlet and a third desorbed gas outlet. The reclaimed gas outlet is connected to the heating furnace 50, and the third desorbed gas outlet is connected to the second fuel gas inlet to send the third desorbed gas into the heating furnace 50 as fuel gas for heating. The third desorbed gas outlet is also connected to the gas pipeline 80 to send the third desorbed gas into the gas pipeline 80. Another part of the hydrogen-based vertical shaft furnace top gas is directly fed into the heating furnace 50 as fuel gas after heat exchange.

[0153] The COREX gas treatment unit includes a second dust removal device, a fifth compressor 43, and a second decarbonization device 44 connected sequentially from the COREX gas outlet. The second dust removal device includes a second coarse dust collector 41 and a wet dust collector 42. The COREX gas discharged from the COREX system 100 is subjected to coarse dust removal, wet dust removal, and pressurization before entering the second decarbonization device 44 for decarbonization. It is divided into COREX decarbonized gas and fourth desorbed gas. The second decarbonization device 44 is provided with a COREX decarbonized gas outlet and a fourth desorbed gas outlet. The COREX decarbonized gas outlet is connected to the heating furnace 50, and the fourth desorbed gas outlet is connected to the steelmaking workshop 90 to send the fourth desorbed gas into the steelmaking workshop 90 for CO2 steelmaking.

[0154] Heating furnace 50 is used to heat hydrogen, converter decarburization gas, recycled gas and COREX decarburization gas. The hydrogen and recycled gas are mixed with converter decarburization gas and / or COREX decarburization gas in heating furnace 50 to form hydrogen-based vertical furnace reducing gas. Heating furnace 50 is provided with hydrogen-based vertical furnace reducing gas outlet end, which is connected to hydrogen-based vertical furnace 60. Hydrogen-based vertical furnace 60 uses hydrogen-based vertical furnace reducing gas to produce sponge iron.

[0155] Blast Furnace 70 uses the first desorption gas for low-carbon smelting to produce liquid iron.

[0156] In summary, the technology provided by the above embodiments of the present invention addresses the technical problem of utilizing secondary energy in steel plants and avoiding high-investment reforming and conversion, and provides a new low-carbon and efficient hydrogen metallurgical method. This is of great significance for reducing primary energy consumption of hydrogen-based vertical shaft furnaces and reducing carbon emissions from blast furnaces.

[0157] The following specific examples illustrate the present invention in detail. It should also be understood that the following examples are only for specific illustrative purposes and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above description of the present invention are within the scope of protection of the present invention. The specific process parameters, etc., in the following examples are merely examples within a suitable range; that is, those skilled in the art can make appropriate selections within the appropriate range based on the description herein, and are not intended to be limited to the specific values ​​in the examples below.

[0158] Example 1

[0159] This embodiment utilizes a hydrogen metallurgical method based on steel plant gas, employing... Figure 1 The system shown will proceed as follows:

[0160] (1) Coke oven gas treatment process

[0161] like Figure 1As shown, purified coke oven gas is pressurized and hydrogen-extracted to obtain hydrogen and a first desorbed gas. The hydrogen is heated and used as part of the reducing gas in a hydrogen-based vertical shaft furnace. The first desorbed gas is pressurized and injected into the blast furnace through a tuyer for low-carbon smelting. The hydrogen extraction method can be any one or more of physical absorption, chemical absorption, or physical-chemical absorption.

[0162] The volume of coke oven gas is 144647 Nm³. 3 The gas flow rate is 68500 Nm³ / h, the temperature is 40℃, and the pressurized gas pressure is 0.55 MPa. The calorific value of hydrogen is 60% of that of coke oven gas, and the gas volume is 68500 Nm³ / h. 3 / h, gas pressure is 0.5MPa, and the temperature after heating is 950℃.

[0163] (2) Blast furnace low-carbon smelting process

[0164] The calorific value of the first desorbed gas delivered to the blast furnace is 1.45 times that of the coke oven gas, and the gas volume is 76147 Nm³. 3 / h, temperature is 40℃, and the pressurized air pressure is 0.4MPa.

[0165] The pressurized first desorbed gas is injected into the blast furnace through the tuyeres for low-carbon smelting. Simultaneously, oxygen enrichment is applied, with an oxygen enrichment rate of 32%. This reduces the coke ratio in the blast furnace by 50 kg / tHM and lowers CO2 emissions by 13.3%.

[0166] (3) Converter gas treatment process

[0167] The purified converter gas is pressurized and decarburized to obtain converter decarburized gas and second desorbed gas. The converter decarburized gas is heated and used as part of the reducing gas in the hydrogen-based vertical shaft furnace, while the second desorbed gas is transported to the steel plant's gas pipeline network. The decarburization method can be any one or more of physical absorption, chemical absorption, or physical-chemical absorption.

[0168] The converter gas volume is 93252 Nm³. 3 The gas flow rate is 73500 Nm³ / h, the temperature is 40℃, and the pressurized gas pressure is 0.55 MPa. The calorific value of the converter decarburization gas is 1.17 times that of the converter gas, and the gas volume is 73500 Nm³ / h. 3 The gas pressure is 0.5 MPa, and the temperature after heating is 950℃. The calorific value of the second desorbed gas is 38% of that of the converter gas, and the gas volume is 19752 Nm³. 3 / h, temperature is 40℃, air pressure is 0.02MPa.

[0169] (4) Hydrogen-based vertical furnace top gas circulation process

[0170] The top gas from the hydrogen-based vertical shaft furnace undergoes dust removal, heat exchange, pressurization, and decarbonization and denitrification to obtain recycled gas and third desorbed gas. The recycled gas is heated and used as part of the reducing gas for the hydrogen-based vertical shaft furnace. Part of the third desorbed gas is used as fuel gas for heating the reducing gas, and the other part is transported to the steel plant's gas pipeline network. The decarbonization and denitrification methods can be any one or more of physical absorption, chemical absorption, and physical-chemical absorption methods.

[0171] The hydrogen content of the top gas from the hydrogen-based vertical shaft furnace is 38.6%, the CO content is 12.2%, and the gas volume is 299064 Nm³. 3 / h, gas pressure 0.26MPa, temperature 507℃; dust content in the top gas of the hydrogen-based vertical shaft furnace after coarse dust removal ≤6g / Nm³ 3 The dust content in the top gas of the hydrogen-based vertical shaft furnace after dry dust removal is ≤5mg / Nm³. 3 The temperature of the top gas from the hydrogen-based vertical shaft furnace is reduced to ≤40℃ after two-stage heat exchange with recycled gas and cooling water. 15.4% of the top gas from the hydrogen-based vertical shaft furnace after heat exchange is used as fuel gas for heating and reducing. The remaining part of the top gas from the hydrogen-based vertical shaft furnace after heat exchange is pressurized to 0.55MPa. The recycled gas after decarbonization and denitrification undergoes a first-stage heat exchange with the top gas from the hydrogen-based vertical shaft furnace after dust removal, and the temperature of the recycled gas is increased to 412℃.

[0172] The calorific value of the recycled gas is 1.35 times that of the top gas of the hydrogen-based vertical shaft furnace, and the gas volume is 149,835 Nm³. 3 The gas pressure is 0.5 MPa, and it is further heated to 950℃. The calorific value of the third desorbed gas is 87.7% of the calorific value of the top gas of the hydrogen-based vertical shaft furnace, and the gas volume is 58113 Nm³. 3 / h, temperature is 40℃, air pressure is 0.02MPa.

[0173] (5) Hydrogen-based shaft furnace smelting process

[0174] Hydrogen, converter decarburization gas, and recycled gas are mixed and heated to become the reducing gas of the hydrogen-based vertical shaft furnace, producing qualified sponge iron. The fuel gas used for heating the reducing gas consists of the third desorption gas and the top gas of the hydrogen-based vertical shaft furnace after heat exchange. The volume fraction of the third desorption gas is 0, and the volume fraction of the top gas of the hydrogen-based vertical shaft furnace after heat exchange is 100%.

[0175] The hydrogen content of the reducing gas in the hydrogen-based vertical shaft furnace is 55.8%, the H2 / CO ratio is 3.2, and the gas volume is 295,824 Nm³. 3 The gas pressure is 0.4 MPa, and the temperature is 950℃. The metallization rate of the sponge iron is ≥93%, and the carbon content is 2.0%.

[0176] Example 2

[0177] This embodiment utilizes a hydrogen metallurgical method based on steel plant gas, employing... Figure 1The system shown will proceed as follows:

[0178] (1) Coke oven gas treatment process

[0179] like Figure 1 As shown, purified coke oven gas is pressurized and hydrogen-extracted to obtain hydrogen and a first desorbed gas. The hydrogen is heated and used as part of the reducing gas in a hydrogen-based vertical shaft furnace. The first desorbed gas is pressurized and injected into the blast furnace through a tuyer for low-carbon smelting. The hydrogen extraction method can be any one or more of physical absorption, chemical absorption, or physical-chemical absorption.

[0180] The volume of coke oven gas is 161,540 Nm³. 3 The gas flow rate is 76500 Nm³ / h, the temperature is 40℃, and the pressurized gas pressure is 0.55 MPa. The calorific value of hydrogen is 65% of that of coke oven gas, and the gas volume is 76500 Nm³ / h. 3 / h, gas pressure is 0.5MPa, and the temperature after heating is 950℃.

[0181] (2) Blast furnace low-carbon smelting process

[0182] The calorific value of the first desorbed gas delivered to the blast furnace is 1.3 times that of the coke oven gas, and the gas volume is 85040 Nm³. 3 The gas is heated at 40℃ and pressurized to 0.4MPa per hour. The first desorbed gas after pressurization is injected into the blast furnace through the tuyeres for low-carbon smelting. Simultaneously, oxygen enrichment is applied, with an oxygen enrichment rate of 39%. This reduces the coke ratio in the blast furnace by 60 kg / tHM and reduces CO2 emissions by 16%.

[0183] (3) Converter gas treatment process

[0184] The purified converter gas is pressurized and decarburized to obtain converter decarburized gas and second desorbed gas. The converter decarburized gas is heated and used as part of the reducing gas in the hydrogen-based vertical shaft furnace, while the second desorbed gas is transported to the steel plant's gas pipeline network. The decarburization method can be any one or more of physical absorption, chemical absorption, or physical-chemical absorption.

[0185] The converter gas volume is 67243 Nm³. 3 The gas flow rate is 53000 Nm³ / h, the temperature is 40℃, and the pressurized gas pressure is 0.55 MPa. The calorific value of the converter decarburization gas is 1.17 times that of the converter gas, and the gas volume is 53000 Nm³ / h. 3 The gas pressure is 0.5 MPa, and the temperature after heating is 950℃. The calorific value of the second desorbed gas is 38% of that of the converter gas, and the gas volume is 14243 Nm³. 3 / h, temperature is 40℃, air pressure is 0.02MPa.

[0186] (4) Hydrogen-based vertical furnace top gas circulation process

[0187] The top gas from the hydrogen-based vertical shaft furnace undergoes dust removal, heat exchange, pressurization, and decarbonization and denitrification to obtain recycled gas and third desorbed gas. The recycled gas is heated and used as part of the reducing gas for the hydrogen-based vertical shaft furnace. Part of the third desorbed gas is used as fuel gas for heating the reducing gas, and the other part is transported to the steel plant's gas pipeline network. The decarbonization and denitrification methods can be any one or more of physical absorption, chemical absorption, and physical-chemical absorption methods.

[0188] The hydrogen content of the top gas from the hydrogen-based vertical shaft furnace is 47.3%, the CO content is 9.2%, and the gas volume is 294,491 Nm³. 3 / h, gas pressure 0.26MPa, temperature 484℃; dust content in the top gas of the hydrogen-based vertical shaft furnace after coarse dust removal ≤6g / Nm³ 3 The dust content in the top gas of the hydrogen-based vertical shaft furnace after dry dust removal is ≤5mg / Nm³. 3 The temperature of the top gas from the hydrogen-based vertical shaft furnace is reduced to ≤40℃ after two-stage heat exchange with recycled gas and cooling water. 14.5% of the top gas from the hydrogen-based vertical shaft furnace after heat exchange is used as fuel gas for heating and reducing. The remaining part of the top gas from the hydrogen-based vertical shaft furnace after heat exchange is pressurized to 0.55MPa. The recycled gas after decarbonization and denitrification undergoes a first-stage heat exchange with the top gas from the hydrogen-based vertical shaft furnace after dust removal, and the temperature of the recycled gas is increased to 389℃.

[0189] The calorific value of the recycled gas is 1.37 times that of the top gas of the hydrogen-based vertical shaft furnace, and the gas volume is 157,531 Nm³. 3 The gas pressure is 0.5 MPa, and it is further heated to 950℃. The calorific value of the third desorbed gas is 82.3% of the calorific value of the top gas of the hydrogen-based vertical shaft furnace, and the gas volume is 44190 Nm³. 3 / h, temperature is 40℃, air pressure is 0.02MPa.

[0190] (5) Hydrogen-based shaft furnace smelting process

[0191] Hydrogen, converter decarburization gas, and recycled gas are mixed and heated to become the reducing gas of the hydrogen-based vertical shaft furnace, producing qualified sponge iron. The fuel gas used for heating the reducing gas consists of the third desorption gas and the top gas of the hydrogen-based vertical shaft furnace after heat exchange. The volume fraction of the third desorption gas is 0, and the volume fraction of the top gas of the hydrogen-based vertical shaft furnace after heat exchange is 100%.

[0192] The hydrogen content of the reducing gas in the hydrogen-based vertical shaft furnace is 66.5%, the H2 / CO ratio is 5.1, and the gas volume is 291505 Nm³. 3 The gas pressure is 0.4 MPa, and the temperature is 950℃. The metallization rate of the sponge iron is ≥93%, and the carbon content is 1.3%.

[0193] Example 3

[0194] This embodiment utilizes a hydrogen metallurgical method based on steel plant gas, employing... Figure 1The system shown will proceed as follows:

[0195] (1) Coke oven gas treatment process

[0196] like Figure 1 As shown, purified coke oven gas is pressurized and hydrogen-extracted to obtain hydrogen and a first desorbed gas. The hydrogen is heated and used as part of the reducing gas in a hydrogen-based vertical shaft furnace. The first desorbed gas is pressurized and injected into the blast furnace through a tuyer for low-carbon smelting. The hydrogen extraction method can be any one or more of physical absorption, chemical absorption, or physical-chemical absorption.

[0197] The volume of coke oven gas is 171043 Nm³. 3 The gas flow rate is 81000 Nm³ / h, the temperature is 40℃, and the pressurized gas pressure is 0.55 MPa. The calorific value of hydrogen is 65% of that of coke oven gas, and the gas volume is 81000 Nm³ / h. 3 / h, gas pressure is 0.5MPa, and the temperature after heating is 950℃.

[0198] (2) Blast furnace low-carbon smelting process

[0199] The calorific value of the first desorbed gas delivered to the blast furnace is 1.3 times that of the coke oven gas, and the gas volume is 90043 Nm³. 3 The gas pressure is 0.4 MPa after pressurization at a temperature of 40℃. The first desorbed gas after pressurization is injected into the blast furnace through the tuyeres for low-carbon smelting. Simultaneously, oxygen enrichment is applied, with an oxygen enrichment rate of 44%. This reduces the coke ratio of the blast furnace by 68 kg / tHM and reduces CO2 emissions by 18.1%.

[0200] (3) Converter gas treatment process

[0201] The purified converter gas is pressurized and decarburized to obtain converter decarburized gas and second desorbed gas. The converter decarburized gas is heated and used as part of the reducing gas in the hydrogen-based vertical shaft furnace, while the second desorbed gas is transported to the steel plant's gas pipeline network. The decarburization method can be any one or more of physical absorption, chemical absorption, or physical-chemical absorption.

[0202] The converter gas volume is 51384 Nm³. 3 The gas flow rate is 40℃, and the pressurized gas pressure is 0.55MPa. The calorific value of the converter decarburization gas is 1.17 times that of the converter gas, and the gas volume is 40500 Nm³. 3 The gas pressure is 0.5 MPa, and the temperature after heating is 950℃. The calorific value of the second desorbed gas is 38% of that of the converter gas, and the gas volume is 10884 Nm³. 3 / h, temperature is 40℃, air pressure is 0.02MPa.

[0203] (4) Hydrogen-based vertical furnace top gas circulation process

[0204] The top gas from the hydrogen-based vertical shaft furnace undergoes dust removal, heat exchange, pressurization, and decarbonization and denitrification to obtain recycled gas and third desorbed gas. The recycled gas is heated and used as part of the reducing gas for the hydrogen-based vertical shaft furnace. Part of the third desorbed gas is used as fuel gas for heating the reducing gas, and the other part is transported to the steel plant's gas pipeline network. The decarbonization and denitrification methods can be any one or more of physical absorption, chemical absorption, and physical-chemical absorption methods.

[0205] The hydrogen content of the top gas from the hydrogen-based vertical shaft furnace is 52.6%, the CO content is 7.3%, and the gas volume is 289212 Nm³. 3 / h, gas pressure 0.26MPa, temperature 466℃; dust content in the top gas of the hydrogen-based vertical shaft furnace after coarse dust removal ≤6g / Nm³ 3 The dust content in the top gas of the hydrogen-based vertical shaft furnace after dry dust removal is ≤5mg / Nm³. 3 The temperature of the top gas from the hydrogen-based vertical shaft furnace is reduced to ≤40℃ after two-stage heat exchange with recycled gas and cooling water. 14.2% of the top gas from the hydrogen-based vertical shaft furnace after heat exchange is used as fuel gas for heating and reducing. The remaining part of the top gas from the hydrogen-based vertical shaft furnace after heat exchange is pressurized to 0.55MPa. The recycled gas after decarbonization and denitrification undergoes a first-stage heat exchange with the top gas from the hydrogen-based vertical shaft furnace after dust removal, and the temperature of the recycled gas is increased to 371℃.

[0206] The calorific value of the recycled gas is 1.38 times that of the top gas of the hydrogen-based vertical shaft furnace, and the gas volume is 160173 Nm³. 3 The gas pressure is 0.5 MPa, and it is further heated to 950℃. The calorific value of the third desorbed gas is 79.2% of the calorific value of the top gas of the hydrogen-based vertical shaft furnace, and the gas volume is 35346 Nm³. 3 / h, temperature is 40℃, air pressure is 0.02MPa.

[0207] (5) Hydrogen-based shaft furnace smelting process

[0208] Hydrogen, converter decarburization gas, and recycled gas are mixed and heated to become the reducing gas of the hydrogen-based vertical shaft furnace, producing qualified sponge iron. The fuel gas used for heating the reducing gas consists of the third desorption gas and the top gas of the hydrogen-based vertical shaft furnace after heat exchange. The volume fraction of the third desorption gas is 0, and the volume fraction of the top gas of the hydrogen-based vertical shaft furnace after heat exchange is 100%.

[0209] The hydrogen content of the reducing gas in the hydrogen-based vertical shaft furnace is 73.2%, the H2 / CO ratio is 7.2, and the gas volume is 286135 Nm³. 3 The gas pressure is 0.4 MPa, and the temperature is 950℃. The metallization rate of the sponge iron is ≥93%, and the carbon content is 0.7%.

[0210] Example 4

[0211] This embodiment utilizes a hydrogen metallurgical method based on steel plant gas, employing... Figure 1The system shown will proceed as follows:

[0212] (1) Coke oven gas treatment process

[0213] like Figure 1 As shown, purified coke oven gas is pressurized and hydrogen-extracted to obtain hydrogen and a first desorbed gas. The hydrogen is heated and used as part of the reducing gas in a hydrogen-based vertical shaft furnace. The first desorbed gas is pressurized and injected into the blast furnace through a tuyer for low-carbon smelting. The hydrogen extraction method can be any one or more of physical absorption, chemical absorption, or physical-chemical absorption.

[0214] The volume of coke oven gas is 186,880 Nm³. 3 The gas flow rate is 88500 Nm³ / h, the temperature is 40℃, and the pressurized gas pressure is 0.55 MPa. The calorific value of hydrogen is 65% of that of coke oven gas, and the gas volume is 88500 Nm³ / h. 3 / h, gas pressure is 0.5MPa, and the temperature after heating is 950℃.

[0215] (2) Blast furnace low-carbon smelting process

[0216] The calorific value of the first desorbed gas delivered to the blast furnace is 1.3 times that of the coke oven gas, and the gas volume is 98380 Nm³. 3 The gas pressure is 0.4 MPa after pressurization at a temperature of 40℃. The first desorbed gas after pressurization is injected into the blast furnace through the tuyeres for low-carbon smelting. Simultaneously, oxygen enrichment is applied, with an oxygen enrichment rate of 52%. This reduces the coke ratio of the blast furnace by 73 kg / tHM and reduces CO2 emissions by 19.5%.

[0217] (3) Converter gas treatment process

[0218] The purified converter gas is pressurized and decarburized to obtain converter decarburized gas and second desorbed gas. The converter decarburized gas is heated and used as part of the reducing gas in the hydrogen-based vertical shaft furnace, while the second desorbed gas is transported to the steel plant's gas pipeline network. The decarburization method can be any one or more of physical absorption, chemical absorption, or physical-chemical absorption.

[0219] The converter gas volume is 24740 Nm³. 3 The gas flow rate is 19500 Nm³ / h, the temperature is 40℃, and the pressurized gas pressure is 0.55 MPa. The calorific value of the converter decarburization gas is 1.17 times that of the converter gas, and the gas volume is 19500 Nm³ / h. 3 The gas pressure is 0.5 MPa, and the temperature after heating is 950℃. The calorific value of the second desorbed gas is 38% of that of the converter gas, and the gas volume is 5240 Nm³. 3 / h, temperature is 40℃, air pressure is 0.02MPa.

[0220] (4) Hydrogen-based vertical furnace top gas circulation process

[0221] The top gas from the hydrogen-based vertical shaft furnace undergoes dust removal, heat exchange, pressurization, and decarbonization and denitrification to obtain recycled gas and third desorbed gas. The recycled gas is heated and used as part of the reducing gas for the hydrogen-based vertical shaft furnace. Part of the third desorbed gas is used as fuel gas for heating the reducing gas, and the other part is transported to the steel plant's gas pipeline network. The decarbonization and denitrification methods can be any one or more of physical absorption, chemical absorption, and physical-chemical absorption methods.

[0222] The hydrogen content of the top gas from the hydrogen-based vertical shaft furnace is 63.2%, the CO content is 3.7%, and the gas volume is 287,905 Nm³. 3 / h, gas pressure 0.26MPa, temperature 447℃; dust content in the top gas of the hydrogen-based vertical shaft furnace after coarse dust removal ≤6g / Nm³ 3 The dust content in the top gas of the hydrogen-based vertical shaft furnace after dry dust removal is ≤5mg / Nm³. 3 The temperature of the top gas from the hydrogen-based vertical shaft furnace is reduced to ≤40℃ after two-stage heat exchange with recycled gas and cooling water. 13.1% of the top gas from the hydrogen-based vertical shaft furnace after heat exchange is used as fuel gas for heating and reducing. The remaining part of the top gas from the hydrogen-based vertical shaft furnace after heat exchange is pressurized to 0.55MPa. The recycled gas after decarbonization and denitrification undergoes a first-stage heat exchange with the top gas from the hydrogen-based vertical shaft furnace after dust removal, and the temperature of the recycled gas is increased to 352℃.

[0223] The calorific value of the recycled gas is 1.37 times that of the top gas of the hydrogen-based vertical shaft furnace, and the gas volume is 172011 Nm³. 3 The gas pressure is 0.5 MPa, and it is further heated to 950℃. The calorific value of the third desorbed gas is 74.3% of the calorific value of the top gas of the hydrogen-based vertical shaft furnace, and the gas volume is 20480 Nm³. 3 / h, temperature is 40℃, air pressure is 0.02MPa.

[0224] (5) Hydrogen-based shaft furnace smelting process

[0225] Hydrogen, converter decarburization gas, and recycled gas are mixed and heated to become the reducing gas of the hydrogen-based vertical shaft furnace, producing qualified sponge iron. The fuel gas used for heating the reducing gas consists of the third desorption gas and the top gas of the hydrogen-based vertical shaft furnace after heat exchange. The volume fraction of the third desorption gas is 0, and the volume fraction of the top gas of the hydrogen-based vertical shaft furnace after heat exchange is 100%.

[0226] The hydrogen content of the reducing gas in the hydrogen-based vertical shaft furnace is 85.6%, the H2 / CO ratio is 17.3, and the gas volume is 284,559 Nm³. 3 The gas pressure is 0.4 MPa, and the temperature is 950℃. The metallization rate of the sponge iron is ≥93%, and the carbon content is 0.3%.

[0227] Example 5

[0228] This embodiment utilizes a hydrogen metallurgical method based on steel plant gas, employing... Figure 1The system shown will proceed as follows:

[0229] (1) Coke oven gas treatment process

[0230] like Figure 1 As shown, purified coke oven gas is pressurized and hydrogen-extracted to obtain hydrogen and a first desorbed gas. The hydrogen is heated and used as part of the reducing gas in a hydrogen-based vertical shaft furnace. The first desorbed gas is pressurized and injected into the blast furnace through a tuyer for low-carbon smelting. The hydrogen extraction method can be any one or more of physical absorption, chemical absorption, or physical-chemical absorption.

[0231] The volume of coke oven gas is 195,960 Nm³. 3 The gas flow rate is 92800 Nm³ / h, the temperature is 40℃, and the pressurized gas pressure is 0.55 MPa. The calorific value of hydrogen is 65% of that of coke oven gas, and the gas volume is 92800 Nm³ / h. 3 / h, gas pressure is 0.5MPa, and the temperature after heating is 950℃.

[0232] (2) Blast furnace low-carbon smelting process

[0233] The calorific value of the first desorbed gas delivered to the blast furnace is 1.3 times that of the coke oven gas, and the gas volume is 103160 Nm³. 3 The gas pressure is 0.4 MPa after pressurization at a temperature of 40℃. The first desorbed gas after pressurization is injected into the blast furnace through the tuyeres for low-carbon smelting. Simultaneously, oxygen enrichment is applied, with an oxygen enrichment rate of 57%. This reduces the coke ratio of the blast furnace by 76 kg / tHM and reduces CO2 emissions by 20.3%.

[0234] (3) Converter gas treatment process

[0235] The purified converter gas is pressurized and decarburized to obtain converter decarburized gas and second desorbed gas. The converter decarburized gas is heated and used as part of the reducing gas in the hydrogen-based vertical shaft furnace, while the second desorbed gas is transported to the steel plant's gas pipeline network. The decarburization method can be any one or more of physical absorption, chemical absorption, or physical-chemical absorption.

[0236] The converter gas volume is 7232 Nm³. 3 The gas flow rate is 5700 Nm³ / h, the temperature is 40℃, and the pressurized gas pressure is 0.55 MPa. The calorific value of the converter decarburization gas is 1.17 times that of the converter gas, and the gas volume is 5700 Nm³ / h. 3 The gas pressure is 0.5 MPa, and the temperature after heating is 950℃. The calorific value of the second desorbed gas is 38% of that of the converter gas, and the gas volume is 1532 Nm³. 3 / h, temperature is 40℃, air pressure is 0.02MPa.

[0237] (4) Hydrogen-based vertical furnace top gas circulation process

[0238] The top gas from the hydrogen-based vertical shaft furnace undergoes dust removal, heat exchange, pressurization, and decarbonization and denitrification to obtain recycled gas and third desorbed gas. The recycled gas is heated and used as part of the reducing gas for the hydrogen-based vertical shaft furnace. Part of the third desorbed gas is used as fuel gas for heating the reducing gas, and the other part is transported to the steel plant's gas pipeline network. The decarbonization and denitrification methods can be any one or more of physical absorption, chemical absorption, and physical-chemical absorption methods.

[0239] The hydrogen content of the top gas from the hydrogen-based vertical shaft furnace is 71.8%, the CO content is 1.1%, and the gas volume is 282312 Nm³. 3 / h, gas pressure 0.26MPa, temperature 426℃; dust content in the top gas of the hydrogen-based vertical shaft furnace after coarse dust removal ≤6g / Nm³ 3 The dust content in the top gas of the hydrogen-based vertical shaft furnace after dry dust removal is ≤5mg / Nm³. 3 The temperature of the top gas from the hydrogen-based vertical shaft furnace is reduced to ≤40℃ after two-stage heat exchange with recycled gas and cooling water. 12.3% of the top gas from the hydrogen-based vertical shaft furnace after heat exchange is used as fuel gas for heating and reducing. The remaining part of the top gas from the hydrogen-based vertical shaft furnace after heat exchange is pressurized to 0.55MPa. The recycled gas after decarbonization and denitrification undergoes a first-stage heat exchange with the top gas from the hydrogen-based vertical shaft furnace after dust removal, and the temperature of the recycled gas is increased to 331℃.

[0240] The calorific value of the recycled gas is 1.33 times that of the top gas of the hydrogen-based vertical shaft furnace, and the gas volume is 181078 Nm³. 3 The gas pressure is 0.5 MPa, and it is further heated to 950℃. The calorific value of the third desorbed gas is 70.3% of the calorific value of the top gas of the hydrogen-based vertical shaft furnace, and the gas volume is 10461 Nm³. 3 / h, temperature is 40℃, air pressure is 0.02MPa.

[0241] (5) Hydrogen-based shaft furnace smelting process

[0242] Hydrogen, converter decarburization gas, and recycled gas are mixed and heated to become the reducing gas of the hydrogen-based vertical shaft furnace, producing qualified sponge iron. The fuel gas used for heating the reducing gas consists of the third desorption gas and the top gas of the hydrogen-based vertical shaft furnace after heat exchange. The volume fraction of the third desorption gas is 0, and the volume fraction of the top gas of the hydrogen-based vertical shaft furnace after heat exchange is 100%.

[0243] The hydrogen content of the reducing gas in the hydrogen-based vertical shaft furnace is 95.5%, the H2 / CO ratio is 64.3, and the gas volume is 279736 Nm³. 3 The gas pressure is 0.4 MPa, and the temperature is 950℃. The metallization rate of the sponge iron is ≥93%, and the carbon content is 0.2%.

[0244] Example 6

[0245] This embodiment utilizes a hydrogen metallurgical method based on steel plant gas, employing... Figure 1The system shown will proceed as follows:

[0246] (1) Coke oven gas treatment process

[0247] like Figure 1 As shown, purified coke oven gas is pressurized and hydrogen-extracted to obtain hydrogen and a first desorbed gas. The hydrogen is heated and used as part of the reducing gas in a hydrogen-based vertical shaft furnace. The first desorbed gas is pressurized and injected into the blast furnace through a tuyer for low-carbon smelting. The hydrogen extraction method can be any one or more of physical absorption, chemical absorption, or physical-chemical absorption.

[0248] The volume of coke oven gas is 140424 Nm³. 3 The gas flow rate is 66500 Nm³ / h, the temperature is 40℃, and the pressurized gas pressure is 0.55 MPa. The calorific value of hydrogen is 65% of that of coke oven gas, and the gas volume is 66500 Nm³ / h. 3 / h, gas pressure is 0.5MPa, and the temperature after heating is 950℃.

[0249] (2) Blast furnace low-carbon smelting process

[0250] The calorific value of the first desorbed gas delivered to the blast furnace is 1.3 times that of the coke oven gas, and the gas volume is 73924 Nm³. 3 The gas pressure is 0.4 MPa after pressurization at a temperature of 40℃. The first desorbed gas after pressurization is injected into the blast furnace through the tuyeres for low-carbon smelting. Simultaneously, oxygen enrichment is applied, with an oxygen enrichment rate of 31%. This reduces the coke ratio of the blast furnace by 48 kg / tHM and reduces CO2 emissions by 12.8%.

[0251] (3) Converter gas treatment process

[0252] The purified converter gas is pressurized and decarburized to obtain converter decarburized gas and second desorbed gas. The converter decarburized gas is heated and used as part of the reducing gas in the hydrogen-based vertical shaft furnace, while the second desorbed gas is transported to the steel plant's gas pipeline network. The decarburization method can be any one or more of physical absorption, chemical absorption, or physical-chemical absorption.

[0253] The converter gas volume is 93252 Nm³. 3 The gas flow rate is 73500 Nm³ / h, the temperature is 40℃, and the pressurized gas pressure is 0.55 MPa. The calorific value of the converter decarburization gas is 1.17 times that of the converter gas, and the gas volume is 73500 Nm³ / h. 3 The gas pressure is 0.5 MPa, and the temperature after heating is 950℃. The calorific value of the second desorbed gas is 38% of that of the converter gas, and the gas volume is 19752 Nm³. 3 / h, temperature is 40℃, air pressure is 0.02MPa.

[0254] (4) Hydrogen-based vertical furnace top gas circulation process

[0255] The top gas from the hydrogen-based vertical shaft furnace undergoes dust removal, heat exchange, pressurization, and decarbonization and denitrification to obtain recycled gas and third desorbed gas. The recycled gas is heated and used as part of the reducing gas for the hydrogen-based vertical shaft furnace. Part of the third desorbed gas is used as fuel gas for heating the reducing gas, and the other part is transported to the steel plant's gas pipeline network. The decarbonization and denitrification methods can be any one or more of physical absorption, chemical absorption, and physical-chemical absorption methods.

[0256] The hydrogen content of the top gas from the hydrogen-based vertical shaft furnace is 38.3%, the CO content is 12.1%, and the gas volume is 301,836 Nm³. 3 / h, gas pressure 0.26MPa, temperature 512℃; dust content in the top gas of the hydrogen-based vertical shaft furnace after coarse dust removal ≤6g / Nm³ 3 The dust content in the top gas of the hydrogen-based vertical shaft furnace after dry dust removal is ≤5mg / Nm³. 3 The temperature of the top gas from the hydrogen-based vertical shaft furnace is reduced to ≤40℃ after two-stage heat exchange with recycled gas and cooling water. 13.7% of the top gas from the hydrogen-based vertical shaft furnace after heat exchange is used as fuel gas for heating and reducing. The remaining part of the top gas from the hydrogen-based vertical shaft furnace after heat exchange is pressurized to 0.55MPa. The recycled gas after decarbonization and denitrification undergoes a first-stage heat exchange with the top gas from the hydrogen-based vertical shaft furnace after dust removal, and the temperature of the recycled gas is increased to 417℃.

[0257] The calorific value of the recycled gas is 1.35 times that of the top gas of the hydrogen-based vertical shaft furnace, and the gas volume is 154,468 Nm³. 3 The gas pressure is 0.5 MPa, and it is further heated to 950℃. The calorific value of the third desorbed gas is 87.6% of the calorific value of the top gas of the hydrogen-based vertical shaft furnace, and the gas volume is 54086 Nm³. 3 / h, temperature is 40℃, air pressure is 0.02MPa.

[0258] (5) Hydrogen-based shaft furnace smelting process

[0259] Hydrogen, converter decarburization gas, and recycled gas are mixed and heated to become the reducing gas of the hydrogen-based vertical shaft furnace, producing qualified sponge iron. The fuel gas used for heating the reducing gas consists of the third desorption gas and the hydrogen-based vertical shaft furnace top gas after heat exchange. The volume fraction of the third desorption gas is 15%, and the volume fraction of the hydrogen-based vertical shaft furnace top gas after heat exchange is 85%.

[0260] The hydrogen content of the reducing gas in the hydrogen-based vertical shaft furnace is 55.2%, the H2 / CO ratio is 3.2, and the gas volume is 299317 Nm³. 3 The gas pressure is 0.4 MPa, and the temperature is 950℃. The metallization rate of the sponge iron is ≥93%, and the carbon content is 1.8%.

[0261] Example 7

[0262] This embodiment utilizes a hydrogen metallurgical method based on steel plant gas, employing... Figure 1The system shown will proceed as follows:

[0263] (1) Coke oven gas treatment process

[0264] like Figure 1 As shown, purified coke oven gas is pressurized and hydrogen-extracted to obtain hydrogen and a first desorbed gas. The hydrogen is heated and used as part of the reducing gas in a hydrogen-based vertical shaft furnace. The first desorbed gas is pressurized and injected into the blast furnace through a tuyer for low-carbon smelting. The hydrogen extraction method can be any one or more of physical absorption, chemical absorption, or physical-chemical absorption.

[0265] The volume of coke oven gas is 137679 Nm³. 3 The gas flow rate is 65200 Nm³ / h, the temperature is 40℃, and the pressurized gas pressure is 0.55 MPa. The calorific value of hydrogen is 65% of that of coke oven gas, and the gas volume is 65200 Nm³ / h. 3 / h, gas pressure is 0.5MPa, and the temperature after heating is 950℃.

[0266] (2) Blast furnace low-carbon smelting process

[0267] The calorific value of the first desorbed gas delivered to the blast furnace is 1.3 times that of the coke oven gas, and the gas volume is 72479 Nm³. 3 The gas is heated at 40℃ and pressurized to 0.4MPa per hour. The first desorbed gas after pressurization is injected into the blast furnace through the tuyeres for low-carbon smelting. Simultaneously, oxygen enrichment (30%) is applied. This reduces the coke ratio in the blast furnace by 45 kg / tHM and decreases CO2 emissions by 12.0%.

[0268] (3) Converter gas treatment process

[0269] The purified converter gas is pressurized and decarburized to obtain converter decarburized gas and second desorbed gas. The converter decarburized gas is heated and used as part of the reducing gas in the hydrogen-based vertical shaft furnace, while the second desorbed gas is transported to the steel plant's gas pipeline network. The decarburization method can be any one or more of physical absorption, chemical absorption, or physical-chemical absorption.

[0270] The converter gas volume is 93252 Nm³. 3 The gas flow rate is 73500 Nm³ / h, the temperature is 40℃, and the pressurized gas pressure is 0.55 MPa. The calorific value of the converter decarburization gas is 1.25 times that of the converter gas, and the gas volume is 73500 Nm³ / h. 3 The gas pressure is 0.5 MPa, and the temperature after heating is 950℃. The calorific value of the second desorbed gas is 35% of that of the converter gas, and the gas volume is 19752 Nm³. 3 / h, temperature is 40℃, air pressure is 0.02MPa.

[0271] (4) Hydrogen-based vertical furnace top gas circulation process

[0272] The top gas from the hydrogen-based vertical shaft furnace undergoes dust removal, heat exchange, pressurization, and decarbonization and denitrification to obtain recycled gas and third desorbed gas. The recycled gas is heated and used as part of the reducing gas for the hydrogen-based vertical shaft furnace. Part of the third desorbed gas is used as fuel gas for heating the reducing gas, and the other part is transported to the steel plant's gas pipeline network. The decarbonization and denitrification methods can be any one or more of physical absorption, chemical absorption, and physical-chemical absorption methods.

[0273] The hydrogen content of the top gas from the hydrogen-based vertical shaft furnace is 38.2%, the CO content is 12.1%, and the gas volume is 305108 Nm³. 3 / h, gas pressure 0.26MPa, temperature 514℃; dust content in the top gas of the hydrogen-based vertical shaft furnace after coarse dust removal ≤6g / Nm³ 3 The dust content in the top gas of the hydrogen-based vertical shaft furnace after dry dust removal is ≤5mg / Nm³. 3 The temperature of the top gas from the hydrogen-based vertical shaft furnace is reduced to ≤40℃ after two-stage heat exchange with recycled gas and cooling water. 12.4% of the top gas from the hydrogen-based vertical shaft furnace after heat exchange is used as fuel gas for heating and reducing. The remaining part of the top gas from the hydrogen-based vertical shaft furnace after heat exchange is pressurized to 0.55MPa. The recycled gas after decarbonization and denitrification undergoes a first-stage heat exchange with the top gas from the hydrogen-based vertical shaft furnace after dust removal, and the temperature of the recycled gas is increased to 419℃.

[0274] The calorific value of the recycled gas is 1.34 times that of the top gas from the hydrogen-based vertical shaft furnace, and the gas volume is 158906 Nm³. 3 The gas pressure is 0.5 MPa, and it is further heated to 950℃. The calorific value of the third desorbed gas is 87.5% of the calorific value of the top gas of the hydrogen-based vertical shaft furnace, and the gas volume is 51155 Nm³. 3 / h, temperature is 40℃, air pressure is 0.02MPa.

[0275] (5) Hydrogen-based shaft furnace smelting process

[0276] Hydrogen, converter decarburization gas, and recycled gas are mixed and heated to become the reducing gas for the hydrogen-based vertical shaft furnace, producing qualified sponge iron. The fuel gas used for heating the reducing gas consists of the third desorption gas and the top gas of the hydrogen-based vertical shaft furnace after heat exchange. The volume fraction of the third desorption gas is 25%, and the volume fraction of the top gas of the hydrogen-based vertical shaft furnace after heat exchange is 75%.

[0277] The hydrogen content of the reducing gas in the hydrogen-based vertical shaft furnace is 55.2%, the H2 / CO ratio is 3.2, and the gas volume is 301185 Nm³. 3 The gas pressure is 0.4 MPa, and the temperature is 950℃. The metallization rate of the sponge iron is ≥93%, and the carbon content is 1.6%.

[0278] Example 8

[0279] This embodiment utilizes a hydrogen metallurgical method based on steel plant gas, employing... Figure 1The system shown will proceed as follows:

[0280] (1) Coke oven gas treatment process

[0281] like Figure 1 As shown, purified coke oven gas is pressurized and hydrogen-extracted to obtain hydrogen and a first desorbed gas. The hydrogen is heated and used as part of the reducing gas in a hydrogen-based vertical shaft furnace. The first desorbed gas is pressurized and injected into the blast furnace through a tuyer for low-carbon smelting. The hydrogen extraction method can be any one or more of physical absorption, chemical absorption, or physical-chemical absorption.

[0282] The volume of coke oven gas is 153094 Nm³. 3 The gas flow rate is 72500 Nm³ / h, the temperature is 40℃, and the pressurized gas pressure is 0.45 MPa. The calorific value of hydrogen is 65% of that of coke oven gas, and the gas volume is 72500 Nm³ / h. 3 / h, gas pressure is 0.4MPa, and the temperature after heating is 1050℃.

[0283] (2) Blast furnace low-carbon smelting process

[0284] The calorific value of the first desorbed gas delivered to the blast furnace is 1.3 times that of the coke oven gas, and the gas volume is 80594 Nm³. 3 The gas pressure is 0.3 MPa after pressurization at a temperature of 40℃. The first desorbed gas after pressurization is injected into the blast furnace through the tuyeres for low-carbon smelting. Simultaneously, oxygen enrichment (30%) is applied. This reduces the coke ratio in the blast furnace by 45 kg / tHM and reduces CO2 emissions by 12.0%.

[0285] (3) Converter gas treatment process

[0286] The purified converter gas is pressurized and decarburized to obtain converter decarburized gas and second desorbed gas. The converter decarburized gas is heated and used as part of the reducing gas in the hydrogen-based vertical shaft furnace, while the second desorbed gas is transported to the steel plant's gas pipeline network. The decarburization method can be any one or more of physical absorption, chemical absorption, or physical-chemical absorption.

[0287] The converter gas volume is 100230 Nm³. 3 The gas flow rate is 79000 Nm³ / h, the temperature is 40℃, and the pressurized gas pressure is 0.45 MPa. The calorific value of the converter decarburization gas is 1.05 times that of the converter gas, and the gas volume is 79000 Nm³ / h. 3 The gas pressure is 0.4 MPa, and the temperature after heating is 1050℃. The calorific value of the second desorption gas is 40% of that of the converter gas, and the gas volume is 21230 Nm³. 3 / h, temperature is 40℃, air pressure is 0.02MPa.

[0288] (4) Hydrogen-based vertical furnace top gas circulation process

[0289] The top gas from the hydrogen-based vertical shaft furnace undergoes dust removal, heat exchange, pressurization, and decarbonization and denitrification to obtain recycled gas and third desorbed gas. The recycled gas is heated and used as part of the reducing gas for the hydrogen-based vertical shaft furnace. Part of the third desorbed gas is used as fuel gas for heating the reducing gas, and the other part is transported to the steel plant's gas pipeline network. The decarbonization and denitrification methods can be any one or more of physical absorption, chemical absorption, and physical-chemical absorption methods.

[0290] The hydrogen content of the top gas from the hydrogen-based vertical shaft furnace is 40.1%, the CO content is 12.7%, and the gas volume is 318,767 Nm³. 3 / h, gas pressure 0.16MPa, temperature 534℃; dust content in the top gas of the hydrogen-based vertical shaft furnace after coarse dust removal ≤6g / Nm³ 3 The dust content in the top gas of the hydrogen-based vertical shaft furnace after dry dust removal is ≤5mg / Nm³. 3 The temperature of the top gas from the hydrogen-based vertical shaft furnace is reduced to ≤40℃ after two-stage heat exchange with recycled gas and cooling water. 17.1% of the top gas from the hydrogen-based vertical shaft furnace after heat exchange is used as fuel gas for heating and reducing. The remaining part of the top gas from the hydrogen-based vertical shaft furnace after heat exchange is pressurized to 0.45MPa. The recycled gas after decarbonization and denitrification undergoes a first-stage heat exchange with the top gas from the hydrogen-based vertical shaft furnace after dust removal, and the temperature of the recycled gas is increased to 439℃.

[0291] The calorific value of the recycled gas is 1.32 times that of the top gas of the hydrogen-based vertical shaft furnace, and the gas volume is 159,740 Nm³. 3 The gas pressure is 0.4 MPa, and it is further heated to 1050℃. The calorific value of the third desorbed gas is 88.3% of the calorific value of the top gas of the hydrogen-based vertical shaft furnace, and the gas volume is 60510 Nm³. 3 / h, temperature is 40℃, air pressure is 0.02MPa.

[0292] (5) Hydrogen-based shaft furnace smelting process

[0293] Hydrogen, converter decarburization gas, and recycled gas are mixed and heated to become the reducing gas of the hydrogen-based vertical shaft furnace, producing qualified sponge iron. The fuel gas used for heating the reducing gas consists of the third desorption gas and the top gas of the hydrogen-based vertical shaft furnace after heat exchange. The volume fraction of the third desorption gas is 0, and the volume fraction of the top gas of the hydrogen-based vertical shaft furnace after heat exchange is 100%.

[0294] The hydrogen content of the reducing gas in the hydrogen-based vertical shaft furnace is 55.8%, the H2 / CO ratio is 3.2, and the gas volume is 317,686 Nm³. 3 The gas pressure is 0.3 MPa, and the temperature is 1050℃. The metallization rate of the sponge iron is ≥95%, and the carbon content is 1.9%.

[0295] Example 9

[0296] This embodiment utilizes a hydrogen metallurgical method based on steel plant gas, employing... Figure 2The system shown will proceed as follows:

[0297] (1) Coke oven gas treatment process

[0298] like Figure 2 As shown, purified coke oven gas is pressurized and hydrogen-extracted to obtain hydrogen and a first desorbed gas. The hydrogen is heated and used as part of the reducing gas in a hydrogen-based vertical shaft furnace. The first desorbed gas is pressurized and injected into the blast furnace through a tuyer for low-carbon smelting. The hydrogen extraction method can be any one or more of physical absorption, chemical absorption, or physical-chemical absorption.

[0299] The volume of coke oven gas is 114451 Nm³. 3 The gas flow rate is 54200 Nm³ / h, the temperature is 40℃, and the pressurized gas pressure is 0.55 MPa. The calorific value of hydrogen is 65% of that of coke oven gas, and the gas volume is 54200 Nm³ / h. 3 / h, gas pressure is 0.5MPa, and the temperature after heating is 950℃.

[0300] (2) Blast furnace low-carbon smelting process

[0301] The calorific value of the first desorbed gas delivered to the blast furnace is 1.3 times that of the coke oven gas, and the gas volume is 60251 Nm³. 3 The gas is heated at 40℃ and pressurized to 0.4MPa per hour. The first desorbed gas after pressurization is injected into the blast furnace through the tuyeres for low-carbon smelting. Simultaneously, oxygen enrichment is applied at a rate of 25%. This reduces the coke ratio in the blast furnace by 45 kg / tHM and decreases CO2 emissions by 12%.

[0302] (3) COREX gas treatment process

[0303] A portion of the COREX gas undergoes wet dust removal, pressurization, and decarburization to obtain COREX decarburized gas and fourth desorption gas. The COREX decarburized gas is heated and used as part of the reducing gas in a hydrogen-based vertical shaft furnace, while the fourth desorption gas is transported to the steelmaking workshop for CO2 steelmaking. The decarburization method can be any one or more of physical absorption, chemical absorption, or physical-chemical absorption.

[0304] The volume of COREX gas is 111194 Nm³. 3 / h, dust content after coarse dust removal ≤6g / Nm 3 After wet dust removal, the dust content is ≤5mg / Nm³. 3 The temperature is 40℃, and the pressurized gas pressure is 0.55MPa. The calorific value of COREX decarbonized gas is 1.5 times that of COREX coal gas, and the gas volume is 74500 Nm³. 3 The gas pressure is 0.5 MPa, and the temperature after heating is 950℃. The calorific value of the fourth desorbed gas is 18.7% of the calorific value of COREX coal gas, and the gas volume is 36694 Nm³. 3 / h, temperature is 40℃, air pressure is 0.02MPa.

[0305] (4) Hydrogen-based vertical furnace top gas circulation process

[0306] The top gas from the hydrogen-based vertical shaft furnace undergoes dust removal, heat exchange, pressurization, and decarbonization and denitrification to obtain recycled gas and third desorbed gas. The recycled gas is heated and used as part of the reducing gas for the hydrogen-based vertical shaft furnace. Part of the third desorbed gas is used as fuel gas for heating the reducing gas, and the other part is transported to the steel plant's gas pipeline network. The decarbonization and denitrification methods can be any one or more of physical absorption, chemical absorption, and physical-chemical absorption methods.

[0307] The hydrogen content of the top gas from the hydrogen-based vertical shaft furnace is 45.7%, the CO content is 16.2%, and the gas volume is 275027 Nm³. 3 / h, gas pressure 0.26MPa, temperature 484℃; dust content in the top gas of the hydrogen-based vertical shaft furnace after coarse dust removal ≤6g / Nm³ 3 The dust content in the top gas of the hydrogen-based vertical shaft furnace after dry dust removal is ≤5mg / Nm³. 3 The temperature of the top gas from the hydrogen-based vertical shaft furnace is reduced to ≤40℃ after two-stage heat exchange with recycled gas and cooling water. 28.6% of the top gas from the hydrogen-based vertical shaft furnace after heat exchange is used as fuel gas for heating and reducing. The remaining part of the top gas from the hydrogen-based vertical shaft furnace after heat exchange is pressurized to 0.55MPa. The recycled gas after decarbonization and denitrification undergoes a first-stage heat exchange with the top gas from the hydrogen-based vertical shaft furnace after dust removal, and the temperature of the recycled gas is increased to 389℃.

[0308] The calorific value of the recycled gas is 1.34 times that of the top gas of the hydrogen-based vertical shaft furnace, and the gas volume is 138,975 Nm³. 3 The gas pressure is 0.5 MPa, and it is further heated to 950℃. The calorific value of the third desorbed gas is 94.6% of the calorific value of the top gas of the hydrogen-based vertical shaft furnace, and the gas volume is 55629 Nm³. 3 / h, temperature is 40℃, air pressure is 0.02MPa.

[0309] (5) Hydrogen-based shaft furnace smelting process

[0310] Hydrogen, recycled gas, and COREX decarburization gas are mixed and heated to become the reducing gas for the hydrogen-based shaft furnace, producing qualified sponge iron. The fuel gas used for heating the reducing gas consists of the third desorption gas and the top gas of the hydrogen-based shaft furnace after heat exchange. The volume fraction of the third desorption gas is 0, and the volume fraction of the top gas of the hydrogen-based shaft furnace after heat exchange is 100%.

[0311] The hydrogen content of the reducing gas in the hydrogen-based vertical shaft furnace is 63.6%, the H2 / CO ratio is 2.82, and the gas volume is 272403 Nm³. 3 The gas pressure is 0.4 MPa, and the temperature is 950℃. The metallization rate of the sponge iron is ≥93%, and the carbon content is 3.4%.

[0312] Example 10

[0313] This embodiment utilizes a hydrogen metallurgical method based on steel plant gas, employing... Figure 2 The system shown will proceed as follows:

[0314] (1) Coke oven gas treatment process

[0315] like Figure 2 As shown, purified coke oven gas is pressurized and hydrogen-extracted to obtain hydrogen and a first desorbed gas. The hydrogen is heated and used as part of the reducing gas in a hydrogen-based vertical shaft furnace. The first desorbed gas is pressurized and injected into the blast furnace through a tuyer for low-carbon smelting. The hydrogen extraction method can be any one or more of physical absorption, chemical absorption, or physical-chemical absorption.

[0316] The volume of coke oven gas is 194271 Nm³. 3 The gas flow rate is 92000 Nm³ / h, the temperature is 40℃, and the pressurized gas pressure is 0.55 MPa. The calorific value of hydrogen is 65% of that of coke oven gas, and the gas volume is 92000 Nm³ / h. 3 / h, gas pressure is 0.5MPa, and the temperature after heating is 950℃.

[0317] (2) Blast furnace low-carbon smelting process

[0318] The calorific value of the first desorbed gas delivered to the blast furnace is 1.3 times that of the coke oven gas, and the gas volume is 102271 Nm³. 3 The gas pressure is 0.4 MPa after pressurization at a temperature of 40℃. The first desorbed gas after pressurization is injected into the blast furnace through the tuyeres for low-carbon smelting. Simultaneously, oxygen enrichment is applied, with an oxygen enrichment rate of 58%. This reduces the coke ratio of the blast furnace by 78 kg / tHM and reduces CO2 emissions by 20.8%.

[0319] (3) COREX gas treatment process

[0320] A portion of the COREX gas undergoes wet dust removal, pressurization, and decarburization to obtain COREX decarburized gas and fourth desorption gas. The COREX decarburized gas is heated and used as part of the reducing gas in a hydrogen-based vertical shaft furnace, while the fourth desorption gas is transported to the steelmaking workshop for CO2 steelmaking. The decarburization method can be any one or more of physical absorption, chemical absorption, or physical-chemical absorption.

[0321] The COREX gas volume is 5970 Nm³. 3 / h, dust content after coarse dust removal ≤6g / Nm 3 After wet dust removal, the dust content is ≤5mg / Nm³. 3The temperature is 40℃, and the pressurized gas pressure is 0.55MPa. The calorific value of COREX decarbonized gas is 1.45 times that of COREX coal gas, and the gas volume is 4000Nm³. 3 The gas pressure is 0.5 MPa, and the temperature after heating is 950℃. The calorific value of the fourth desorption gas is 18% of that of COREX coal gas, and the gas volume is 1970 Nm³. 3 / h, temperature is 40℃, air pressure is 0.02MPa.

[0322] (4) Hydrogen-based vertical furnace top gas circulation process

[0323] The top gas from the hydrogen-based vertical shaft furnace undergoes dust removal, heat exchange, pressurization, and decarbonization and denitrification to obtain recycled gas and third desorbed gas. The recycled gas is heated and used as part of the reducing gas for the hydrogen-based vertical shaft furnace. Part of the third desorbed gas is used as fuel gas for heating the reducing gas, and the other part is transported to the steel plant's gas pipeline network. The decarbonization and denitrification methods can be any one or more of physical absorption, chemical absorption, and physical-chemical absorption methods.

[0324] The hydrogen content of the top gas from the hydrogen-based vertical shaft furnace is 70.7%, the CO content is 0.9%, and the gas volume is 271,160 Nm³. 3 / h, gas pressure 0.26MPa, temperature 410℃; dust content in the top gas of the hydrogen-based vertical shaft furnace after coarse dust removal ≤6g / Nm³ 3 The dust content in the top gas of the hydrogen-based vertical shaft furnace after dry dust removal is ≤5mg / Nm³. 3 The temperature of the top gas from the hydrogen-based vertical shaft furnace is reduced to ≤40℃ after two-stage heat exchange with recycled gas and cooling water. 4.8% of the top gas from the hydrogen-based vertical shaft furnace after heat exchange is used as fuel gas for heating and reducing. The remaining part of the top gas from the hydrogen-based vertical shaft furnace after heat exchange is pressurized to 0.55MPa. The recycled gas after decarbonization and denitrification undergoes a first-stage heat exchange with the top gas from the hydrogen-based vertical shaft furnace after dust removal, and the temperature of the recycled gas is increased to 315℃.

[0325] The calorific value of the recycled gas is 1.37 times that of the top gas of the hydrogen-based vertical shaft furnace, and the gas volume is 167,380 Nm³. 3 The gas pressure is 0.5 MPa, and it is further heated to 950℃. The calorific value of the third desorbed gas is 78.5% of the calorific value of the top gas of the hydrogen-based vertical shaft furnace, and the gas volume is 8414 Nm³. 3 / h, temperature is 40℃, air pressure is 0.02MPa.

[0326] (5) Hydrogen-based shaft furnace smelting process

[0327] Hydrogen, recycled gas, and COREX decarburization gas are mixed and heated to become the reducing gas for the hydrogen-based shaft furnace, producing qualified sponge iron. The fuel gas used for heating the reducing gas consists of the third desorption gas and the top gas of the hydrogen-based shaft furnace after heat exchange. The volume fraction of the third desorption gas is 0, and the volume fraction of the top gas of the hydrogen-based shaft furnace after heat exchange is 100%.

[0328] The hydrogen content of the reducing gas from the hydrogen-based vertical shaft furnace is 95.1%, the H2 / CO ratio is 77, and the gas volume is 269225 Nm³. 3 The gas pressure is 0.4 MPa, and the temperature is 950℃. The metallization rate of the sponge iron is ≥93%, and the carbon content is 0.2%.

[0329] Example 11

[0330] This embodiment utilizes a hydrogen metallurgical method based on steel plant gas, employing... Figure 2 The system shown will proceed as follows:

[0331] (1) Coke oven gas treatment process

[0332] like Figure 2 As shown, purified coke oven gas is pressurized and hydrogen-extracted to obtain hydrogen and a first desorbed gas. The hydrogen is heated and used as part of the reducing gas in a hydrogen-based vertical shaft furnace. The first desorbed gas is pressurized and injected into the blast furnace through a tuyer for low-carbon smelting. The hydrogen extraction method can be any one or more of physical absorption, chemical absorption, or physical-chemical absorption.

[0333] The volume of coke oven gas is 114451 Nm³. 3 The gas flow rate is 54200 Nm³ / h, the temperature is 40℃, and the pressurized gas pressure is 0.55 MPa. The calorific value of hydrogen is 70% of that of coke oven gas, and the gas volume is 54200 Nm³ / h. 3 / h, gas pressure is 0.5MPa, and the temperature after heating is 1050℃.

[0334] (2) Blast furnace low-carbon smelting process

[0335] The calorific value of the first desorbed gas delivered to the blast furnace is 1.15 times that of the coke oven gas, and the gas volume is 60251 Nm³. 3 The gas is heated at 40℃ and pressurized to 0.4MPa per hour. The first desorbed gas after pressurization is injected into the blast furnace through the tuyeres for low-carbon smelting. Simultaneously, oxygen enrichment is applied at a rate of 25%. This reduces the coke ratio in the blast furnace by 45 kg / tHM and decreases CO2 emissions by 12%.

[0336] (3) COREX gas treatment process

[0337] A portion of the COREX gas undergoes wet dust removal, pressurization, and decarburization to obtain COREX decarburized gas and fourth desorption gas. The COREX decarburized gas is heated and used as part of the reducing gas in a hydrogen-based vertical shaft furnace, while the fourth desorption gas is transported to the steelmaking workshop for CO2 steelmaking. The decarburization method can be any one or more of physical absorption, chemical absorption, or physical-chemical absorption.

[0338] The volume of COREX gas is 123,881 Nm³. 3 / h, dust content after coarse dust removal ≤6g / Nm 3 After wet dust removal, the dust content is ≤5mg / Nm³. 3 The temperature is 40℃, and the pressurized gas pressure is 0.55MPa. The calorific value of COREX decarbonized gas is 1.55 times that of COREX coal gas, and the gas volume is 83000 Nm³. 3 The gas pressure is 0.5 MPa, and the temperature after heating is 1050℃. The calorific value of the fourth desorbed gas is 19% of the calorific value of COREX coal gas, and the gas volume is 40881 Nm³. 3 / h, temperature is 40℃, air pressure is 0.02MPa.

[0339] (4) Hydrogen-based vertical furnace top gas circulation process

[0340] The top gas from the hydrogen-based vertical shaft furnace undergoes dust removal, heat exchange, pressurization, and decarbonization and denitrification to obtain recycled gas and third desorbed gas. The recycled gas is heated and used as part of the reducing gas for the hydrogen-based vertical shaft furnace. Part of the third desorbed gas is used as fuel gas for heating the reducing gas, and the other part is transported to the steel plant's gas pipeline network. The decarbonization and denitrification methods can be any one or more of physical absorption, chemical absorption, and physical-chemical absorption methods.

[0341] The hydrogen content of the top gas from the hydrogen-based vertical shaft furnace is 44.9%, the CO content is 17.6%, and the gas volume is 285,648 Nm³. 3 / h, gas pressure 0.26MPa, temperature 503℃; dust content in the top gas of the hydrogen-based vertical shaft furnace after coarse dust removal ≤6g / Nm³ 3 The dust content in the top gas of the hydrogen-based vertical shaft furnace after dry dust removal is ≤5mg / Nm³. 3 The temperature of the top gas from the hydrogen-based vertical shaft furnace is reduced to ≤40℃ after two-stage heat exchange with recycled gas and cooling water. 29.8% of the top gas from the hydrogen-based vertical shaft furnace after heat exchange is used as fuel gas for heating and reducing. The remaining part of the top gas from the hydrogen-based vertical shaft furnace after heat exchange is pressurized to 0.55MPa. The recycled gas after decarbonization and denitrification undergoes a first-stage heat exchange with the top gas from the hydrogen-based vertical shaft furnace after dust removal, and the temperature of the recycled gas is increased to 408℃.

[0342] The calorific value of the recycled gas is 1.32 times that of the top gas of the hydrogen-based vertical shaft furnace, and the gas volume is 140,990 Nm³. 3The gas pressure is 0.5 MPa, and it is further heated to 1050℃. The calorific value of the third desorbed gas is 95.4% of the calorific value of the top gas of the hydrogen-based vertical shaft furnace, and the gas volume is 59764 Nm³. 3 / h, temperature is 40℃, air pressure is 0.02MPa.

[0343] (5) Hydrogen-based shaft furnace smelting process

[0344] Hydrogen, recycled gas, and COREX decarburization gas are mixed and heated to become the reducing gas for the hydrogen-based shaft furnace, producing qualified sponge iron. The fuel gas used for heating the reducing gas consists of the third desorption gas and the top gas of the hydrogen-based shaft furnace after heat exchange. The volume fraction of the third desorption gas is 0, and the volume fraction of the top gas of the hydrogen-based shaft furnace after heat exchange is 100%.

[0345] The hydrogen content of the reducing gas in the hydrogen-based vertical shaft furnace is 61.7%, the H2 / CO ratio is 2.6, and the gas volume is 283086 Nm³. 3 The gas pressure is 0.4 MPa, and the temperature is 1050℃. The metallization rate of the sponge iron is ≥95%, and the carbon content is 0.3%.

[0346] Example 12

[0347] This embodiment utilizes a hydrogen metallurgical method based on steel plant gas, employing... Figure 3 The system shown will proceed as follows:

[0348] (1) Coke oven gas treatment process

[0349] like Figure 3 As shown, purified coke oven gas is pressurized and hydrogen-extracted to obtain hydrogen and a first desorbed gas. The hydrogen is heated and used as part of the reducing gas in a hydrogen-based vertical shaft furnace. The first desorbed gas is pressurized and injected into the blast furnace through a tuyer for low-carbon smelting. The hydrogen extraction method can be any one or more of physical absorption, chemical absorption, or physical-chemical absorption.

[0350] The volume of coke oven gas is 118252 Nm³. 3 The gas flow rate is 40℃, and the pressurized gas pressure is 0.55MPa. The calorific value of hydrogen is 65% of that of coke oven gas, and the gas volume is 56000 Nm³. 3 / h, gas pressure is 0.5MPa, and the temperature after heating is 950℃.

[0351] (2) Blast furnace low-carbon smelting process

[0352] The calorific value of the first desorption gas delivered to the blast furnace is 1.3 times that of the coke oven gas, and the gas volume is 62252 Nm³. 3The gas is heated at 40℃ and pressurized to 0.4MPa per hour. The first desorbed gas after pressurization is injected into the blast furnace through the tuyeres for low-carbon smelting. Simultaneously, oxygen enrichment is applied at a rate of 27%. This reduces the coke ratio in the blast furnace by 47 kg / tHM and decreases CO2 emissions by 12.5%.

[0353] (3) Converter gas treatment process

[0354] The purified converter gas is pressurized and decarburized to obtain converter decarburized gas and second desorbed gas. The converter decarburized gas is heated and used as part of the reducing gas in the hydrogen-based vertical shaft furnace, while the second desorbed gas is transported to the steel plant's gas pipeline network. The decarburization method can be any one or more of physical absorption, chemical absorption, or physical-chemical absorption.

[0355] The converter gas volume is 18397 Nm³. 3 The gas flow rate is 14500 Nm³ / h, the temperature is 40℃, and the pressurized gas pressure is 0.55 MPa. The calorific value of the converter decarburization gas is 1.17 times that of the converter gas, and the gas volume is 14500 Nm³ / h. 3 The gas pressure is 0.5 MPa, and the temperature after heating is 950℃. The calorific value of the second desorbed gas is 38% of that of the converter gas, and the gas volume is 3897 Nm³. 3 / h, temperature is 40℃, air pressure is 0.02MPa.

[0356] (4) COREX gas treatment process

[0357] A portion of the COREX gas undergoes wet dust removal, pressurization, and decarburization to obtain COREX decarburized gas and fourth desorption gas. The COREX decarburized gas is heated and used as part of the reducing gas in a hydrogen-based vertical shaft furnace, while the fourth desorption gas is transported to the steelmaking workshop for CO2 steelmaking. The decarburization method can be any one or more of physical absorption, chemical absorption, or physical-chemical absorption.

[0358] The volume of COREX gas is 89552 Nm³. 3 / h, dust content after coarse dust removal ≤6g / Nm 3 After wet dust removal, the dust content is ≤5mg / Nm³. 3 The temperature is 40℃, and the pressurized gas pressure is 0.55MPa. The calorific value of COREX decarbonized gas is 1.5 times that of COREX coal gas, and the gas volume is 60,000 Nm³. 3 The gas pressure is 0.5 MPa, and the temperature after heating is 950℃. The calorific value of the fourth desorbed gas is 18.7% of the calorific value of COREX coal gas, and the gas volume is 29552 Nm³. 3 / h, temperature is 40℃, air pressure is 0.02MPa.

[0359] (5) Hydrogen-based vertical furnace top gas circulation process

[0360] The top gas from the hydrogen-based vertical shaft furnace undergoes dust removal, heat exchange, pressurization, and decarbonization and denitrification to obtain recycled gas and third desorbed gas. The recycled gas is heated and used as part of the reducing gas for the hydrogen-based vertical shaft furnace. Part of the third desorbed gas is used as fuel gas for heating the reducing gas, and the other part is transported to the steel plant's gas pipeline network. The decarbonization and denitrification methods can be any one or more of physical absorption, chemical absorption, and physical-chemical absorption methods.

[0361] The hydrogen content of the top gas from the hydrogen-based vertical shaft furnace is 43.2%, the CO content is 15.5%, and the gas volume is 273,720 Nm³. 3 / h, gas pressure 0.26MPa, temperature 484℃; dust content in the top gas of the hydrogen-based vertical shaft furnace after coarse dust removal ≤6g / Nm³ 3 The dust content in the top gas of the hydrogen-based vertical shaft furnace after dry dust removal is ≤5mg / Nm³. 3 The temperature of the top gas from the hydrogen-based vertical shaft furnace is reduced to ≤40℃ after two-stage heat exchange with recycled gas and cooling water. 29.2% of the top gas from the hydrogen-based vertical shaft furnace after heat exchange is used as fuel gas for heating and reducing. The remaining part of the top gas from the hydrogen-based vertical shaft furnace after heat exchange is pressurized to 0.55MPa. The recycled gas after decarbonization and denitrification undergoes a first-stage heat exchange with the top gas from the hydrogen-based vertical shaft furnace after dust removal, and the temperature of the recycled gas is increased to 389℃.

[0362] The calorific value of the recycled gas is 1.35 times that of the top gas from the hydrogen-based vertical shaft furnace, and the gas volume is 136045 Nm³. 3 The gas pressure is 0.5 MPa, and it is further heated to 950℃. The calorific value of the third desorbed gas is 71.5% of the calorific value of the top gas of the hydrogen-based vertical shaft furnace, and the gas volume is 55967 Nm³. 3 / h, temperature is 40℃, air pressure is 0.02MPa.

[0363] (6) Hydrogen-based shaft furnace smelting process

[0364] Hydrogen, converter decarburization gas, recycled gas, and COREX decarburization gas are mixed and heated to become the reducing gas of the hydrogen-based shaft furnace, producing qualified sponge iron. The fuel gas used for heating the reducing gas is the third desorption gas and the top gas of the hydrogen-based shaft furnace after heat exchange. The volume fraction of the third desorption gas is 0, and the volume fraction of the top gas of the hydrogen-based shaft furnace after heat exchange is 100%.

[0365] The hydrogen content of the reducing gas in the hydrogen-based vertical shaft furnace is 60.8%, the H2 / CO ratio is 2.8, and the gas volume is 272,667 Nm³. 3 The gas pressure is 0.4 MPa, and the temperature is 950℃. The metallization rate of the sponge iron is ≥93%, and the carbon content is 3.2%.

[0366] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A hydrogen metallurgical method utilizing steel plant gas, characterized in that, include: Hydrogen extraction is performed on coke oven gas to obtain hydrogen and a first desorbed gas. The first desorbed gas is then injected into a blast furnace for low-carbon smelting to produce molten iron. The converter gas is decarbonized to obtain converter decarbonized gas and second desorbed gas; a portion of the hydrogen-based vertical shaft furnace top gas is decarbonized and denitrified to obtain recycled gas and third desorbed gas. A portion of the COREX gas is decarbonized to obtain COREX decarbonized gas and fourth desorption gas. The hydrogen, recycled gas, and COREX decarburization gas are mixed together to form a hydrogen-based vertical shaft furnace reducing gas for the production of sponge iron; or, the hydrogen, recycled gas, converter decarburization gas, and COREX decarburization gas are mixed together to form a hydrogen-based vertical shaft furnace reducing gas for the production of sponge iron. The method also includes the following operations ① to ④: ① The second desorbed gas is delivered to the steel plant's gas pipeline network; ②A portion of the third desorbed gas is used as fuel gas to heat the reducing gas of the hydrogen-based vertical furnace; ③ The fourth desorbed gas is transported to the steelmaking workshop; ④ Another portion of the top gas from the hydrogen-based vertical shaft furnace is used as fuel gas to heat the reducing gas in the hydrogen-based vertical shaft furnace.

2. The method according to claim 1, characterized in that, The operation ② further includes: delivering another portion of the third desorbed gas to the steel plant's gas pipeline network; And / or, operation ④ further includes: another portion of the hydrogen-based shaft furnace top gas used as fuel gas for heating the reducing gas of the hydrogen-based shaft furnace accounts for 4.7~29.8% of the total volume of the hydrogen-based shaft furnace top gas; And / or, when the method further includes operations ② and ④, in the fuel gas, the volume fraction of the other portion of the hydrogen-based vertical shaft furnace top gas is ≥75%, and the volume fraction of the third desorbed gas is ≤25%.

3. The method according to claim 1, characterized in that, The method further includes a pretreatment process, which includes at least one of purification, dust removal, pressurization, and heat exchange treatment. The purification process is selected from at least one of the following operations ⑤ to ⑥: ⑤ Before hydrogen extraction from coke oven gas, it must be purified. ⑥ Purify the converter gas before decarbonizing it; The dust removal process is selected from at least one of the following operations ⑦ to ⑧: ⑦ Before decarbonizing and denitrifying a portion of the top gas from the hydrogen-based vertical shaft furnace, and before using another portion of the top gas from the hydrogen-based vertical shaft furnace as fuel gas to heat the reducing gas of the hydrogen-based vertical shaft furnace, dust removal treatment is performed on it. ⑧ Before decarbonizing a portion of the COREX gas, it is subjected to dust removal treatment; The pressurization process is selected from the following operations ⑨ to At least one of the following: ⑨ Before hydrogen extraction from coke oven gas, pressurize it; ⑩ Before injecting the first desorbed gas into the blast furnace for low-carbon smelting, pressurize it; Before decarbonizing the converter gas, it is pressurized; Before decarbonizing and denitrifying a portion of the top gas from a hydrogen-based vertical shaft furnace, it is pressurized. Before decarbonizing a portion of the COREX gas, it is pressurized; The heat exchange treatment method includes: performing heat exchange treatment on a portion of the hydrogen-based vertical shaft furnace top gas before decarbonizing and denitrifying it, and on another portion of the hydrogen-based vertical shaft furnace top gas before using it as fuel gas to heat the hydrogen-based vertical shaft furnace reducing gas.

4. The method according to claim 3, characterized in that: The heat exchange treatment method includes: reducing the temperature of the top gas of the hydrogen-based vertical furnace to 40°C or below through heat exchange.

5. The method according to claim 3, characterized in that: The heat exchange treatment method is heat exchange, which includes multi-stage heat exchange, including primary heat exchange and secondary heat exchange. The primary heat exchange method includes: exchanging heat between the hydrogen-based vertical furnace top gas and the recycled gas. The secondary heat exchange method includes: exchanging heat between the hydrogen-based vertical furnace top gas after primary heat exchange and the coolant.

6. The method according to claim 1, characterized in that: The method further includes heating the hydrogen, recycled gas, converter decarburizing gas, and COREX decarburizing gas before mixing the hydrogen and recycled gas and mixing them with the COREX decarburizing gas, or the COREX decarburizing gas and the converter decarburizing gas, to use them together as hydrogen-based vertical shaft furnace reducing gas for the production of sponge iron.

7. The method according to claim 1, characterized in that: The hydrogen content of the reducing gas in the hydrogen-based vertical shaft furnace is 55-95.5%, and the H2 / CO ratio is ≥2.

5. When the output of the hydrogen-based vertical shaft furnace is 1 million tons of sponge iron per year, the reducing gas flow rate of the hydrogen-based vertical shaft furnace is 269,000-317,000 Nm³. 3 The gas pressure is 0.3~0.4MPa, the temperature is 950~1050℃, and the metallization rate of sponge iron in the hydrogen-based vertical furnace is 93~95%, and the carbon content is 0.2~3.4%.

8. The method according to claim 7, characterized in that: When the output of the hydrogen-based shaft furnace is 1 million tons of sponge iron per year, the gas volume of the coke oven gas is 114,000~196,000 Nm³. 3 The gas is supplied at a rate of 20-50℃ per hour, with a pressurized gas pressure of 0.45-0.55 MPa. After hydrogen extraction, the resulting hydrogen has a calorific value of 60-70% of the coke oven gas's calorific value, and a flow rate of 54200-93000 Nm³. 3 / h, gas pressure is 0.4~0.5MPa, and the temperature after heating is 950~1050℃; And / or, when the output of the hydrogen-based shaft furnace is 1 million tons of sponge iron per year, the flow rate of the converter gas is 7200~100000 Nm³. 3 The gas flow rate is 20~50℃, and the pressurized gas pressure is 0.45~0.55MPa; after decarbonization treatment, the calorific value of the decarbonized converter gas is 1.05~1.25 times that of the converter gas, and the gas flow rate is 5700~79000 Nm³. 3 / h, gas pressure is 0.4~0.5MPa, and the temperature after heating is 950~1050℃; And / or, when the output of the hydrogen-based shaft furnace is 1 million tons of sponge iron per year, the hydrogen content of the top gas of the hydrogen-based shaft furnace is 38-72%, the CO content is 0.9-17.6%, and the gas volume is 271,000-319,000 Nm³. 3 The gas flow rate is 136,000-181,000 Nm³ / h, with a pressure of 0.16-0.26 MPa and a temperature of 410-534 °C. After decarbonization and denitrification treatment, the calorific value of the recycled gas obtained from the partial hydrogen-based vertical shaft furnace top gas is 1.32-1.38 times that of the partial hydrogen-based vertical shaft furnace top gas, and the gas flow rate is 136,000-181,000 Nm³ / h. 3 / h, gas pressure is 0.4~0.5MPa, and the temperature after heating is 950~1050℃; And / or, when the output of the hydrogen-based shaft furnace is 1 million tons of sponge iron per year, the amount of the COREX gas is 5970~123900 Nm³. 3 The gas flow rate is 1.55 Nm³ / h, the temperature is 20~50℃, and the pressurized gas pressure is 0.45~0.55 MPa; after decarbonization treatment, the calorific value of the decarbonized COREX gas is 1.45~1.55 times that of the original COREX gas, and the gas flow rate is 4000~83000 Nm³. 3 / h, gas pressure is 0.4~0.5MPa, and the temperature after heating is 950~1050℃.

9. The method according to claim 8, characterized in that: When the output of the hydrogen-based shaft furnace is 1 million tons of sponge iron per year, the gas volume of the coke oven gas is 114,000~196,000 Nm³. 3 The gas is supplied at a rate of 20-50℃ per hour, with a pressurized gas pressure of 0.45-0.55 MPa. After hydrogen extraction, the resulting hydrogen has a calorific value of 60-70% of the coke oven gas's calorific value, and a flow rate of 54200-93000 Nm³. 3 The gas flow rate is 0.4~0.5MPa, the heating temperature is 950~1050℃, and the calorific value of the resulting first desorbed gas is 1.15~1.45 times that of the coke oven gas, with a flow rate of 60200~104000 Nm³. 3 / h, the temperature is 20~50℃; after the first desorbed gas is pressurized, it is injected into the blast furnace through the tuyeres for low-carbon smelting. At the same time as the injection, oxygen is enriched, with an oxygen enrichment rate of 25~58%. The coke ratio of the blast furnace is reduced by 45~78kg / tHM, and the CO2 emissions are reduced by 12~20.8%.

10. A hydrogen metallurgical system utilizing steel plant gas, characterized in that: The system includes a coke oven gas treatment unit, a hydrogen-based vertical shaft furnace top gas recycling unit, a heating furnace, a hydrogen-based vertical shaft furnace, and a blast furnace; The system further includes a COREX gas processing unit, or the system further includes a converter gas processing unit and a COREX gas processing unit; The coke oven gas treatment unit includes a hydrogen extraction device, which is used to extract hydrogen from coke oven gas, divide the coke oven gas into hydrogen and a first desorbed gas, and is provided with a hydrogen outlet end and a first desorbed gas outlet end, the hydrogen outlet end being connected to the heating furnace. The converter gas treatment unit includes a first decarbonization device, which is used to decarbonize the converter gas, divide the converter gas into converter decarbonized gas and second desorbed gas, and is provided with a converter decarbonized gas outlet end, which is connected to the heating furnace. The hydrogen-based vertical furnace top gas recycling unit includes a decarbonization and denitrification device, which is used to remove CO2 and N2 from the hydrogen-based vertical furnace top gas, divides the hydrogen-based vertical furnace top gas into reusable gas and third desorption gas, and is provided with a reusable gas outlet end, which is connected to the heating furnace. The COREX gas treatment unit includes a second decarbonization device, which is used to decarbonize the COREX gas, divide the COREX gas into COREX decarbonized gas and a fourth desorption gas, and is provided with a COREX decarbonized gas outlet end, which is connected to the heating furnace. The heating furnace is used to heat hydrogen, converter decarburization gas, recycled gas, and COREX decarburization gas. The hydrogen and recycled gas are mixed with the COREX decarburization gas, or the COREX decarburization gas and the converter decarburization gas, in the heating furnace to form hydrogen-based vertical shaft furnace reducing gas. The heating furnace is provided with a hydrogen-based vertical shaft furnace reducing gas outlet end, which is connected to the hydrogen-based vertical shaft furnace. The hydrogen-based vertical shaft furnace uses the hydrogen-based vertical shaft furnace reducing gas to produce sponge iron. The first desorbed gas outlet is connected to the blast furnace, and the blast furnace uses the first desorbed gas for low-carbon smelting to produce liquid iron. The system also includes the following equipment: gas pipeline network and steelmaking workshop; The first decarbonization device is also provided with a second desorption gas outlet end, which is connected to the gas pipeline network to send the second desorption gas into the gas pipeline network; The decarbonization and denitrification device is further provided with a third desorption gas outlet end, and the heating furnace is provided with a second fuel gas inlet end. The third desorption gas outlet end is connected to the second fuel gas inlet end so as to send the third desorption gas into the heating furnace as fuel gas for heating. The third desorbed gas outlet is also connected to the gas pipeline network to send the third desorbed gas into the gas pipeline network; The second decarbonization device is also provided with a fourth desorption gas outlet, which is connected to the steelmaking workshop to send the fourth desorption gas into the steelmaking workshop for CO2 steelmaking; The heating furnace is also provided with a first fuel gas inlet, which is the inlet for feeding the top gas of the hydrogen-based vertical furnace into the heating furnace, so as to feed the top gas of the hydrogen-based vertical furnace into the heating furnace as fuel gas for heating.

11. The system according to claim 10, characterized in that, The system further includes at least one of the following devices: a first purification device, a second purification device, a first dust removal device, a second dust removal device, a first pressurizer, a second pressurizer, a third pressurizer, a fourth pressurizer, a fifth pressurizer, and a heat exchange device; The first purification device is installed before the hydrogen extraction device and is used to purify the coke oven gas. The second purification device is installed before the first decarbonization device and is used to purify the converter gas. The first dust removal device is used to remove dust from the top gas of the hydrogen-based vertical furnace; The second dust removal device is installed before the second decarbonization device and is used to remove dust from the COREX gas. The first pressurizer is used to pressurize coke oven gas; The fourth pressurizer is located between the hydrogen extraction device and the blast furnace and is used to pressurize the first desorbed gas; The second pressurizer is used to pressurize the purified converter gas; The third pressurizer is used to pressurize the top gas of the hydrogen-based vertical furnace after heat exchange; the fifth pressurizer is used to pressurize the COREX gas after dust removal; The heat exchange device is used to perform heat exchange treatment on the top gas of the hydrogen-based vertical furnace.

12. The system according to claim 11, characterized in that: The heat exchange device includes a multi-stage heat exchanger, which includes a primary heat exchanger and a secondary heat exchanger connected in sequence. The primary heat exchanger is connected to the outlet end of the recycled gas and is the site where the recycled gas and the top gas of the hydrogen-based vertical shaft furnace exchange heat. The secondary heat exchanger is the site where the coolant and the top gas of the hydrogen-based vertical shaft furnace exchange heat.

13. The application of the method according to any one of claims 1 to 9 or the system according to any one of claims 10 to 12 in the field of hydrogen metallurgy.

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