System and method for utilizing coupling of blast furnace gas and coke oven gas
By designing a blast furnace gas-coupled coke oven gas utilization system, and using the components in blast furnace gas and coke oven gas, the blast furnace hydrogen-rich spraying and chemical products are realized, solving the problems of blast furnace gas utilization and carbon emissions, and reducing energy consumption and cost, providing deep carbon reduction solutions.
Patent Information
- Application Number
- CN202411333067.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-24
- Publication Date
- 2025-01-03
AI Technical Summary
During the blast furnace ironmaking process, it is difficult for the existing technology to effectively utilize and recover blast furnace gas and coke oven gas, resulting in energy waste and carbon emission problems.
A blast furnace gas-coupled coke oven gas utilization system is designed, through CO transformation, CO2 removal, purification, synthesis of ammonia and synthesis of urea devices, using CO, CO2, H2 and N2 in blast furnace gas, CH4 in coke oven gas and H2, realizes hydrogen-rich spraying and production of chemical products, including urea synthesis.
The blast furnace hydrogen-rich injection is achieved, which reduces energy consumption and costs, deeply reduces carbon emissions, provides a feasible carbon reduction path, and utilizes useful components in blast furnace gas to reduce the demand for oxygen-generating equipment.
Smart Images
Figure CN119236821A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of blast furnace ironmaking technology, specifically to a system for utilizing blast furnace gas coupled with coke oven gas, and a method for utilizing blast furnace gas coupled with coke oven gas. Background Technology
[0002] In the long-process blast furnace ironmaking, 75% of the energy comes directly or indirectly from coal. The carbon metallurgical process, primarily based on fossil fuels, uses C or CO as a reducing agent, with the final product being CO or a mixture of CO and CO2. While using some or all hydrogen-containing gases as the reducing agent in the blast furnace can reduce carbon emissions, the effect is limited. Blast furnace gas and coke oven gas, byproducts of the steel industry, are excellent chemical raw materials. On one hand, the CO, CO2, H2, and N2 in blast furnace gas, and the CH4 and H2 in coke oven gas, can be purified and converted to produce hydrogen-rich gas injection. On the other hand, useful components can be used for chemical synthesis, fixing carbon in chemical products for deep carbon reduction. Summary of the Invention
[0003] To recycle and utilize blast furnace gas and coke oven gas, this invention provides a system and method for utilizing blast furnace gas coupled with coke oven gas. This system and method fully utilize the useful components in blast furnace gas, couples coke oven gas to achieve hydrogen-rich injection in the blast furnace, and produces the chemical product urea. It has the advantages of low cost, low energy consumption, and good carbon reduction effect, and is an effective direction and approach for deep carbon reduction.
[0004] The technical solution adopted by this invention to solve its technical problem is:
[0005] A system for utilizing blast furnace gas coupled with coke oven gas includes a blast furnace, a blast furnace gas treatment pipeline, and a coke oven gas treatment pipeline. Along the direction from the inlet to the outlet of the blast furnace gas treatment pipeline, the pipeline contains a CO conversion device, a CO2 removal device, a purification device, an ammonia synthesis device, and a urea synthesis device connected in sequence. The inlet of the blast furnace gas treatment pipeline is connected to the outlet of the blast furnace. The first CO2 outlet of the CO2 removal device is connected to the CO2 output of the urea synthesis device via a first CO2 delivery pipeline. 2. Inlet Connection: Along the direction from the inlet to the outlet of the coke oven gas treatment pipeline, the coke oven gas treatment pipeline contains a refining unit, a pressure swing adsorption (PSA) hydrogen production unit, and a dry reforming unit connected in sequence. The inlet of the coke oven gas treatment pipeline is connected to the coke oven, and the outlet of the coke oven gas treatment pipeline is connected to the blast furnace. The H2 outlet of the PSA hydrogen production unit is connected to the H2 inlet of the ammonia synthesis unit through an H2 conveying pipeline. The second CO2 outlet of the CO2 removal unit is connected to the inlet of the dry reforming unit through a second CO2 conveying pipeline.
[0006] A method for utilizing blast furnace gas coupled with coke oven gas, wherein the method employs the aforementioned blast furnace gas coupled with coke oven gas utilization system, and the method includes the following steps:
[0007] Blast furnace gas enters the blast furnace gas treatment pipeline. The CO conversion unit reacts CO and water vapor in the blast furnace gas to produce CO2 and H2. The CO2 removal unit separates the CO2 generated in the CO conversion unit and discharges it from the first and second CO2 outlets of the CO2 removal unit. The purification unit purifies the H2 generated in the CO conversion unit and the N2 in the blast furnace gas. The ammonia synthesis unit reacts the H2 generated in the CO conversion unit, the H2 separated from the pressure swing adsorption hydrogen production unit, and the N2 in the blast furnace gas to produce NH3. The urea synthesis unit reacts the NH3 generated in the ammonia synthesis unit with the CO2 discharged from the CO2 removal unit to produce urea. Coke oven gas enters the coke oven gas treatment pipeline. The refining unit adsorbs and purifies the coke oven gas. The dry reforming unit reacts the CO2 discharged from the CO2 removal unit with CH4 in the coke oven gas to produce CO and H2. The CO and H2 generated in the dry reforming unit enter the blast furnace for ironmaking.
[0008] The beneficial effects of this invention are:
[0009] 1. The process involves purifying and converting blast furnace gas, utilizing the CO2, N2, and H2 in the gas, along with the hydrogen in the coke oven gas, to synthesize urea. The methane-rich tail gas after hydrogen extraction from the coke oven gas is then dry-reformed with carbon dioxide to generate high-temperature reducing gas rich in CO and H2, which is then sent to the blast furnace to achieve the injection of hydrogen-rich gas into the blast furnace.
[0010] 2. It makes full use of the N2 in blast furnace gas and converts it into high-value chemical products at a low cost.
[0011] 3. The carbon in the blast furnace gas is recycled, and hydrogen-rich gas is injected into the blast furnace, which is beneficial to reducing carbon emissions in the blast furnace.
[0012] 4. The blast furnace adopts oxygen-enriched air, which reduces the scale of oxygen production equipment and has less impact on blast furnace modification and operation methods, thus contributing to the stability of the blast furnace system.
[0013] 5. Urea was synthesized from the carbon in the blast furnace gas, which not only utilizes the components in the gas, but also facilitates deep decarbonization of the blast furnace, resulting in good carbon reduction effect and providing a feasible path for large-scale carbon reduction in blast furnaces.
[0014] 6. The dry reforming outlet delivers high-temperature reducing gas, which is then heated and sent to the blast furnace, solving the problem of heating the reducing gas. This has the advantages of low cost and low energy consumption. Attached Figure Description
[0015] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.
[0016] Figure 1 This is a schematic diagram of the blast furnace gas coupled coke oven gas utilization system described in this invention.
[0017] Figure 2 This is a schematic diagram of a dry reforming unit.
[0018] Explanation of reference numerals in the attached figures:
[0019] 1. Blast furnace; 2. Dust removal unit; 3. Power generation unit; 4. Desulfurization unit; 5. Pressurization unit; 6. CO conversion unit; 7. CO2 removal unit; 8. Purification unit; 9. Ammonia synthesis unit; 10. Urea synthesis unit; 11. Refining unit; 12. Pressure swing adsorption hydrogen production unit; 13. Dry reforming unit; 14. Blast furnace gas treatment pipeline; 15. Coke oven gas treatment pipeline;
[0020] 101. Furnace hearth tuyeres; 102. Lower tuyeres of the furnace body;
[0021] 701. First CO2 delivery pipeline; 702. Second CO2 delivery pipeline;
[0022] 1201, H2 delivery pipelines;
[0023] 1301, Shell; 1302, Heating cavity; 1303, Heat exchange tube; 1304, Cavity inlet; 1305, Cavity outlet; 1306, Heat pipe inlet; 1307, Heat pipe outlet. Detailed Implementation
[0024] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.
[0025] For ease of understanding and description, the following description of the present invention uses absolute positional relationships. Unless otherwise specified, the directional term "above" indicates... Figure 1 The direction above, the directional word "down" indicates Figure 1 The lower side of the middle, the directional word "left" indicates Figure 1 The left side of the direction, the directional word "right" indicates Figure 1 The right-hand direction in the text, the directional word "front" indicates perpendicular to. Figure 1 The direction of the paper and pointing inwards from the paper; the directional word "back" indicates perpendicular to the paper. Figure 1The orientation of the paper is directed towards the outer edge of the paper. This invention is described from the perspective of a reader or user, but the aforementioned directional terms should not be construed as limiting the scope of protection of this invention. Regarding the dimensions and angles of the components, those skilled in the art can determine them specifically based on actual needs or a limited number of experiments.
[0026] like Figure 1 As shown in the embodiment of the present invention, a blast furnace gas coupled coke oven gas utilization system includes a blast furnace 1, a blast furnace gas treatment pipeline 14, and a coke oven gas treatment pipeline 15. Along the direction from the inlet to the outlet of the blast furnace gas treatment pipeline 14, the blast furnace gas treatment pipeline 14 contains a CO conversion device 6, a CO2 removal device 7, a purification device 8, an ammonia synthesis device 9, and a urea synthesis device 10 connected in sequence. The inlet of the blast furnace gas treatment pipeline 14 is connected to the outlet of the blast furnace 1. The first CO2 outlet of the CO2 removal device 7 is connected to the urea synthesis device 10 via a first CO2 conveying pipeline 701. The coke oven gas treatment pipeline 15 is connected to the CO2 inlet of the blast furnace 1. Along the direction from the inlet to the outlet of the coke oven gas treatment pipeline 15, the coke oven gas treatment pipeline 15 contains a refining unit 11, a pressure swing adsorption hydrogen production unit 12, and a dry reforming unit 13 connected in sequence. The inlet of the coke oven gas treatment pipeline 15 is connected to the coke oven, and the outlet of the coke oven gas treatment pipeline 15 is connected to the blast furnace 1. The H2 outlet of the pressure swing adsorption hydrogen production unit 12 is connected to the H2 inlet of the ammonia synthesis unit 9 via the H2 conveying pipeline 1201. The second CO2 outlet of the CO2 removal unit 7 is connected to the inlet of the dry reforming unit 13 via the second CO2 conveying pipeline 702.
[0027] Blast furnace gas contains CO, CO2, H2O, H2, and N2, while coke oven gas contains CH4 and H2. Blast furnace gas from blast furnace 1 enters blast furnace gas treatment pipeline 14, and coke oven gas from the coke oven enters coke oven gas treatment pipeline 15. The aforementioned blast furnace gas coupled with coke oven gas utilization system and method fully utilizes the useful components in blast furnace gas, coupled with coke oven gas to achieve hydrogen-rich injection in the blast furnace, and produces the chemical product urea. It has advantages such as low cost, low energy consumption, and good carbon reduction effect, and is an effective direction and approach for deep carbon reduction.
[0028] like Figure 1 As shown, along the direction from the inlet to the outlet of the blast furnace gas treatment pipeline 14, the blast furnace gas treatment pipeline 14 also includes a dust removal device 2, a power generation device 3, and a desulfurization device 4 connected in sequence. The dust removal device 2, the power generation device 3, and the desulfurization device 4 are located between the blast furnace 1 and the CO conversion device 6. The dust removal device 2 can remove dust from the blast furnace gas, the power generation device 3 can generate electricity using the pressure energy and heat energy of the blast furnace gas, and the desulfurization device 4 can desulfurize the blast furnace gas.
[0029] The blast furnace gas treatment pipeline 14 also includes a pressurization device 5, which is located between the desulfurization device 4 and the CO conversion device 6. The pressurization device 5 can pressurize the blast furnace gas to 0.6 MPa-2.0 MPa. The outlet of the desulfurization device 4 can be connected to an external supply pipeline.
[0030] After desulfurization, the blast furnace gas is pressurized by pressurization device 5 and then enters CO conversion device 6, where CO in the blast furnace gas is converted into H2 and CO2, which then enters CO2 removal device 7. CO2 removal device 7 separates the CO2 from the converted blast furnace gas; a portion of the CO2 is sent to dry reforming unit 13 as feedstock, and the other portion is sent to urea synthesis unit 10 as feedstock. The amount of CO2 sent to dry reforming unit 13 and urea synthesis unit 10 can be flexibly adjusted according to production conditions.
[0031] Dust removal device 2, power generation device 3, desulfurization device 4, and pressurization device 5 can all adopt existing technologies. For example, power generation device 3 can include a steam turbine, and desulfurization device 4 can use molecular sieve adsorption to remove organic and inorganic sulfur. The desulfurized blast furnace gas can be supplied externally or used to synthesize chemical products.
[0032] The CO conversion device 6 can react CO and water vapor (H2O) in the blast furnace gas to generate CO2 and H2. The CO2 removal device 7 can separate the CO2 generated in the CO conversion device 6 and discharge it from the first CO2 outlet and the second CO2 outlet of the CO2 removal device 7. The purification device 8 can purify the H2 generated in the CO conversion device 6 and the N2 in the blast furnace gas. That is, the purification device 8 can purify the gas discharged from the CO2 removal device 7.
[0033] The ammonia synthesis unit 9 can react the H2 generated in the CO conversion unit 6, the H2 separated from the pressure swing adsorption hydrogen production unit 12, and the N2 in the blast furnace gas to generate NH3. The urea synthesis unit 10 can react the NH3 generated in the ammonia synthesis unit 9 with the CO2 discharged from the CO2 removal unit 7 to generate urea.
[0034] like Figure 1 As shown, the CO conversion unit 6, CO2 removal unit 7, purification unit 8, ammonia synthesis unit 9, and urea synthesis unit 10 can all utilize existing technologies. The decarbonized gas is rich in H2 and N2, and then enters the purification unit 8 to remove impurities. After further purification, it is sent to the ammonia synthesis unit 9. The ammonia reacts with CO2 in the urea synthesis unit 10 to produce urea, thus fixing the CO2 and N2 in the blast furnace gas into the product, significantly reducing CO2 emissions, and achieving deep decarbonization.
[0035] The refining unit 11 can adsorb and purify tar, benzene, naphthalene, organic sulfur, and inorganic sulfur in coke oven gas. The refining unit 11 includes a filtration unit, which can be a molecular sieve or made of microcrystalline material. The purified coke oven gas enters the pressure swing adsorption hydrogen production unit 12.
[0036] The pressure swing adsorption (PSA) hydrogen production unit 12 is used to extract H2 from coke oven gas. The PSA unit 12 separates and discharges the H2 from the coke oven gas. The methane-rich tail gas after PSA hydrogen production from the PSA unit 12 is mixed with CO2 separated from the CO2 removal unit 7 and enters the dry reforming unit 13. In the dry reforming unit 13, the methane-rich gas reacts with CO2 to produce CO and H2. The H2 delivery pipeline 1201 can be connected to a green hydrogen supply pipeline.
[0037] like Figure 2 As shown, the refining unit 11, the pressure swing adsorption hydrogen production unit 12, and the dry reforming unit 13 can all be products of existing technology. The dry reforming unit 13 includes a shell 1301, which contains a heating cavity 1302 and a heat exchange tube 1303. The heat exchange tube 1303 contains a catalyst. The CO2 discharged from the CO2 removal unit 7 and the CH4 in the coke oven gas react in the heat exchange tube 1303 to produce CO and H2.
[0038] The dry reforming unit 13 also includes a cavity inlet 1304, a cavity outlet 1305, a heat pipe inlet 1306, and a heat pipe outlet 1307. The outlet end of the second CO2 conveying pipeline 702 is connected to the heat pipe inlet 1306 of the dry reforming unit 13, and the heat pipe outlet 1307 of the dry reforming unit 13 is connected to the hearth tuyeres 101 and the lower tuyeres 102 of the blast furnace 1 described below. The pressure swing adsorption (PSA) hydrogen production unit 12 includes an inlet, a filter outlet, and an H2 outlet. The inlet of the PSA hydrogen production unit 12 is connected to the outlet of the purification unit 11. The filter outlet of the PSA hydrogen production unit 12 is connected to the heat pipe inlet 1306 of the dry reforming unit 13.
[0039] Heat source air enters the heating cavity 1302 through cavity inlet 1304 and exits through cavity outlet 1305. CO2 discharged from CO2 removal device 7 and CH4 from coke oven gas enter through heat pipe inlet 1306, where they generate CO and H2 under the action of a nickel-based catalyst, with an H2 / CO volume ratio greater than 1.5. The generated CO1 and H2 exit through heat pipe outlet 1307. The heat source can heat the heat exchange tube 1303. The heat source can be blast furnace gas or other gaseous fuels.
[0040] Blast furnace 1 includes a hearth tuyer 101 and a lower tuyer 102. The outlet of the coke oven gas treatment pipeline 15 is connected to the hearth tuyer 101 and the lower tuyer 102. The hydrogen-rich reducing gas (i.e., the reaction producing CO1 and H2) at the outlet of the dry reforming unit 13 has a pressure of 0.2MPa-0.6MPa (preferably 0.2MPa-0.4MPa) and a temperature of 800℃-1000℃. The hydrogen-rich reducing gas is blown into the hearth tuyer 101 and the lower tuyer 102 at a rate of 120m³. 3 / tFe-400m 3 / tFe, the injection method can be flexibly adjusted according to production conditions.
[0041] The following describes the connection relationships in the blast furnace gas coupled coke oven gas utilization system. The top gas outlet of blast furnace 1 is connected to dust removal device 2. The outlet of dust removal device 2 is connected to the inlet of power generation device 3. The outlet of power generation device 3 is connected to desulfurization device 4. The gas from the outlet of desulfurization device 4 can be supplied externally or connected to pressurization device 5. The outlet of pressurization device 5 is connected to CO conversion device 6. The outlet of CO conversion device 6 is connected to CO2 removal device 7. CO2 removal device 7 is connected to the outlets of urea synthesis device 10, purification device 8, and pressure swing adsorption hydrogen production device 12. The inlet of purification device 8 is connected to CO2 removal device 7. The outlet of purification device 8 is connected to ammonia synthesis device 9. The inlet of ammonia synthesis device 9 is connected to the outlet of purification device 8, the green hydrogen make-up pipeline, and the hydrogen extraction outlet of pressure swing adsorption hydrogen production device 12. The outlet of ammonia synthesis device 9 is connected to urea synthesis device 10, and the synthetic urea product is supplied externally. The coke oven gas inlet is connected to the refining unit 11, the outlet of the refining unit 11 is connected to the pressure swing adsorption hydrogen production unit 12, the hydrogen extraction outlet of the pressure swing adsorption hydrogen production unit 12 is connected to the inlet of the ammonia synthesis unit 9, the methane-rich tail gas pipeline after hydrogen extraction is connected to the inlet of the dry reforming unit 13, and the outlet of the dry reforming unit 13 is connected to the tuyeres of the blast furnace 1.
[0042] The following describes a method for utilizing blast furnace gas coupled with coke oven gas. This method employs the aforementioned blast furnace gas coupled with coke oven gas utilization system and includes the following steps:
[0043] like Figure 1As shown, blast furnace gas enters blast furnace gas treatment pipeline 14. CO conversion device 6 reacts CO and water vapor in the blast furnace gas to generate CO2 and H2. CO2 removal device 7 separates the CO2 generated in CO conversion device 6 and discharges it from the first CO2 outlet and the second CO2 outlet of CO2 removal device 7. Purification device 8 purifies H2 generated in CO conversion device 6 and N2 in blast furnace gas. Ammonia synthesis device 9 reacts H2 generated in CO conversion device 6, H2 separated from pressure swing adsorption hydrogen production device 12 and N2 in blast furnace gas to generate NH3. Urea synthesis device 10 reacts NH3 generated in ammonia synthesis device 9 and CO2 discharged from CO2 removal device 7 to generate urea.
[0044] Coke oven gas enters coke oven gas treatment pipeline 15, refining unit 11 adsorbs and purifies coke oven gas, pressure swing adsorption hydrogen production unit 12 separates H2 from coke oven gas and discharges methane-rich tail gas, dry reforming unit 13 reacts CO2 discharged from CO2 removal unit 7 with CH4 in coke oven gas to generate CO and H2, and the CO and H2 generated in dry reforming unit 13 enter blast furnace 1 for ironmaking.
[0045] The following details the method for utilizing blast furnace gas coupled with coke oven gas.
[0046] The blast furnace gas discharged from blast furnace 1 enters the inlet of blast furnace gas treatment pipeline 14. The blast furnace gas flows sequentially through dust removal device 2, power generation device 3, desulfurization device 4, pressurization device 5, CO conversion device 6, CO2 removal device 7, purification device 8, ammonia synthesis device 9, and urea synthesis device 10. The urea produced can be supplied externally.
[0047] Dust removal device 2 removes dust from blast furnace gas; power generation device 3 generates electricity using the pressure and heat energy of blast furnace gas; and desulfurization device 4 desulfurizes blast furnace gas. Desulfurization device 4 can be a molecular sieve dry desulfurization device, removing total sulfur to less than 1 mg / Nm³. 3 The pressurization device 5 pressurizes the blast furnace gas to 0.6 MPa-2.0 MPa. The pressurized blast furnace gas then enters the CO conversion device 6, where CO in the blast furnace gas reacts with water vapor to produce CO2 and H2.
[0048] CO conversion device 6 reacts CO and water vapor (H2O) in blast furnace gas to generate CO2 and H2. CO2 removal device 7 separates the CO2 generated in CO conversion device 6 and discharges it from the first CO2 outlet and the second CO2 outlet of CO2 removal device 7. Purification device 8 purifies the H2 generated in CO conversion device 6 and the N2 in blast furnace gas.
[0049] The CO2 removal unit 7 can be a wet removal device, preferably using the alkanolamine method to remove CO2 from the synthesis gas. After removal, the main components of the synthesis gas are H2 and N2. The synthesis gas exiting the CO2 removal unit 7 is further purified by the purification unit 8 to remove H2 and N2, and the purified synthesis gas enters the ammonia synthesis unit 9.
[0050] The ammonia synthesis unit 9 reacts the H2 generated in the CO conversion unit 6, the H2 separated from the pressure swing adsorption hydrogen production unit 12, and the N2 in the blast furnace gas to generate NH3. The urea synthesis unit 10 reacts the NH3 generated in the ammonia synthesis unit 9 with the CO2 discharged from the CO2 removal unit 7 to generate urea.
[0051] The hydrogen required by the ammonia synthesis unit 9 comes partly from the conversion of the original blast furnace gas and partly from hydrogen extraction from coke oven gas; green hydrogen can be added as needed. The produced ammonia is transported to the urea synthesis unit 10, where it is synthesized with CO2 to produce urea. The carbon in the blast furnace gas is fixed in the product, achieving deep decarbonization. This fully utilizes the inert gases N2 and CO2 in the blast furnace gas, eliminating the need for an additional nitrogen generation unit.
[0052] The coke oven gas discharged from the coke oven enters the inlet of the coke oven gas treatment pipeline 15, and then flows sequentially through the refining unit 11, the pressure swing adsorption hydrogen production unit 12, and the dry reforming unit 13.
[0053] The refining unit 11 adsorbs and purifies the coke oven gas by removing tar, benzene, naphthalene, organic sulfur, and inorganic sulfur. The pressure swing adsorption hydrogen production unit 12 separates and discharges H2 from the coke oven gas, and the discharged H2 is sent to the ammonia synthesis unit 9. The CO2 discharged from the CO2 removal unit 7 reacts with CH4 in the coke oven gas in the heat exchange tube 1303 of the dry reforming unit 13 to produce CO and H2.
[0054] The CO and H2 generated in the dry reforming unit 13 enter the blast furnace 1 for ironmaking through the hearth tuyeres 101 and the lower tuyeres 102. Oxygen-enriched coal and pulverized coal can also be added to the blast furnace 1 through the hearth tuyeres 101 to ensure the theoretical combustion temperature in the vortex zone is between 1900℃ and 2100℃. The oxygen enrichment is adjusted according to production requirements; preferably, the mass fraction of oxygen in the mixture of oxygen-enriched coal and pulverized coal is 21%-50%.
[0055] The following details the practical application of the method for utilizing blast furnace gas coupled with coke oven gas.
[0056] Preliminary purification of coke oven gas: 60,000 Nm³ 3The gas is produced at a concentration of 58% H2, 6% CO, 2% CO2, 5% N2, 26% CH4, and 3% other components per hour. It then enters the refining unit 11, where molecular sieves are used for adsorption purification to remove impurities such as inorganic sulfur, organic sulfur, benzene, naphthalene, and tar. The purified gas is then sent to the pressure swing adsorption (PSA) hydrogen production unit 12 to extract H2, which is then sent to the ammonia synthesis unit 9. The PSA tail gas, rich in CH4, is sent to the dry reforming unit 13. Part of the CO2 separated by the CO2 removal unit 7 is also sent to the dry reforming unit 13, which can also be supplied externally. The gas undergoes a conversion reaction in the dry reforming unit, generating a high-temperature reducing gas rich in CO and H2 at a temperature of 900°C. This gas is then hot-pressed to the tuyeres of blast furnace 1. Simultaneously, pulverized coal and oxygen are injected into the tuyeres, with an oxygen concentration of 30%, adjustable according to production requirements. The theoretical combustion temperature in the tuyeres area is 2000°C. The iron ore and coke react in blast furnace 1 to produce molten iron and slag, while the gas is converted into CO2 and H2O, which are discharged from the top of the furnace.
[0057] The blast furnace gas discharged from the top of the blast furnace passes sequentially through dust removal device 2 and power generation device 3, with a dust concentration of less than 10 mg / m³. 3 The gas is sent to desulfurization unit 4. The gas exiting the desulfurization unit is approximately 200,000 Nm³. 3 The blast furnace gas, with a flow rate of [amount missing] h, enters the pressurization unit 5, is pressurized to 1.0 MPa, and then sent to the CO conversion unit 6. The CO and water vapor in the blast furnace gas are reacted with a catalyst to generate H2 and CO2, which is called syngas. The syngas is then sent to the CO2 removal unit 7 to remove and separate the CO2. Part of the separated CO2 is sent to the dry reforming unit 13, and the other part is sent to the urea synthesis unit 10. After decarbonization, the syngas is rich in H2 and N2, and then enters the purification unit 8 for further purification of N2 and H2. The purified syngas is sent to the ammonia synthesis unit 9 to produce ammonia. The synthesized ammonia is sent to the urea synthesis unit 10, where it reacts with CO2 to produce urea.
[0058] This invention utilizes blast furnace gas, which, after purification and conversion, combines the CO2, N2, and H2 from the gas with hydrogen from coke oven gas to synthesize urea. The hydrogen-rich methane gas from the coke oven gas, after hydrogen extraction, undergoes dry reforming with carbon dioxide to produce CO and H2, which is then sent to the blast furnace as heat, enabling the injection of hydrogen-rich gas. This solves the problems of N2 extraction and utilization from blast furnace gas; reduces carbon emissions through hydrogen injection within the blast furnace itself; fixes carbon in the synthesized urea, addressing the issue of deep carbon treatment in blast furnace gas; and provides high-temperature reducing gas at the dry reforming outlet, which is then sent to the blast furnace as heat, solving the heating problem of the reducing gas. It offers advantages such as low cost, low energy consumption, and the ability to deeply reduce carbon emissions.
[0059] The above description is merely a specific embodiment of the present invention and should not be construed as limiting the scope of the invention. Therefore, substitutions of equivalent components, or equivalent changes and modifications made within the scope of protection of the present invention, should still fall within the scope of the present invention. Furthermore, the technical features, technical features and technical solutions, and technical solutions in the present invention can be freely combined and used.
Claims
1. A blast furnace gas coupled coke oven gas utilization system, characterized in that: The blast furnace gas coupled with coke oven gas utilization system comprises a blast furnace (1), a blast furnace gas processing pipeline (14) and a coke oven gas processing pipeline (15); The blast furnace gas treatment pipeline (14) comprises a CO conversion device (6), a CO2 removal device (7), a purification device (8), an ammonia synthesis device (9) and a urea synthesis device (10) which are connected in sequence along the direction from the inlet of the blast furnace gas treatment pipeline (14) to the outlet of the blast furnace gas treatment pipeline (14); the inlet of the blast furnace gas treatment pipeline (14) is connected to the outlet of the blast furnace (1); the first CO2 outlet of the CO2 removal device (7) is connected to the CO2 inlet of the urea synthesis device (10) via a first CO2 transport pipeline (701); The coke oven gas processing pipeline (15) includes a refining device (11), a pressure swing adsorption hydrogen production device (12) and a dry reforming device (13) which are connected in sequence along the direction from the inlet of the coke oven gas processing pipeline (15) to the outlet of the coke oven gas processing pipeline (15). The inlet of the coke oven gas processing pipeline (15) is connected to the coke oven, and the outlet of the coke oven gas processing pipeline (15) is connected to the blast furnace (1). The H2 outlet of the pressure swing adsorption hydrogen production device (12) is connected to the H2 inlet of the synthetic ammonia device (9) through the H2 transmission pipeline (1201), and the second CO2 outlet of the CO2 removal device (7) is connected to the inlet of the dry reforming device (13) through the second CO2 transmission pipeline (702).
2. The blast furnace gas coupled coke oven gas utilization system according to claim 1, characterized in that: The blast furnace gas processing pipeline (14) also includes a dust removal device (2), a power generation device (3) and a desulfurization device (4) which are connected in sequence along the direction from the inlet of the blast furnace gas processing pipeline (14) to the outlet of the blast furnace gas processing pipeline (14). The dust removal device (2), the power generation device (3) and the desulfurization device (4) are located between the blast furnace (1) and the CO conversion device (6). The dust removal device (2) can remove dust from the blast furnace gas, the power generation device (3) can generate electricity by using the pressure energy and thermal energy of the blast furnace gas, and the desulfurization device (4) can desulfurize the blast furnace gas.
3. The blast furnace gas coupled coke oven gas utilization system according to claim 2, characterized in that: The blast furnace gas processing pipeline (14) also includes a pressurizing device (5), which is located between the desulfurization device (4) and the CO conversion device (6). The pressurizing device (5) can pressurize the blast furnace gas to 0.6Mpa-2.0Mpa.
4. The blast furnace gas coupled coke oven gas utilization system according to claim 1, characterized in that: The CO conversion device (6) can react CO and water vapor in the blast furnace gas to generate CO2 and H2. The CO2 removal device (7) can separate the CO2 generated in the CO conversion device (6) and discharge it from the first CO2 outlet and the second CO2 outlet of the CO2 removal device (7). The purification device (8) can purify the H2 generated in the CO conversion device (6) and the N2 in the blast furnace gas.
5. The blast furnace gas coupled coke oven gas utilization system according to claim 4, characterized in that: The ammonia synthesis device (9) can react H2 generated in the CO conversion device (6), H2 separated by the pressure swing adsorption hydrogen production device (12) and N2 in the blast furnace gas to generate NH3, and the urea synthesis device (10) can react NH3 generated in the ammonia synthesis device (9) and CO2 discharged from the CO2 removal device (7) to generate urea.
6. The blast furnace gas coupled coke oven gas utilization system according to claim 1, characterized in that: The refining device (11) can adsorb and purify tar, benzene, naphthalene, organic sulfur and inorganic sulfur in the coke oven gas. The refining device (11) contains a filtering unit, and the filtering unit is a molecular sieve.
7. The blast furnace gas coupled coke oven gas utilization system according to claim 1, characterized in that: The dry reforming device (13) comprises a shell (1301), wherein the shell (1301) comprises a heating cavity (1302) and a heat exchange tube (1303), wherein the heat exchange tube (1303) comprises a catalyst, and the CO2 discharged from the CO2 removal device (7) and the CH4 in the coke oven gas react in the heat exchange tube (1303) to generate CO and H2.
8. The blast furnace gas coupled coke oven gas utilization system according to claim 1, characterized in that: The blast furnace (1) comprises a furnace tuyere (101) and a furnace lower tuyere (102), and the outlet of the coke oven gas processing pipeline (15) is connected to the furnace tuyere (101) and the furnace lower tuyere (102).
9. A method for utilizing blast furnace gas coupled with coke oven gas, characterized in that: The method for utilizing blast furnace gas coupled with coke oven gas adopts the blast furnace gas coupled with coke oven gas utilization system according to claim 1, and the method for utilizing blast furnace gas coupled with coke oven gas comprises the following steps: The blast furnace gas enters the blast furnace gas processing pipeline (14), the CO conversion device (6) causes the CO in the blast furnace gas to react with water vapor to generate CO2 and H2, the CO2 removal device (7) separates the CO2 generated in the CO conversion device (6) and discharges it from the first CO2 outlet and the second CO2 outlet of the CO2 removal device (7), the purification device (8) purifies the H2 generated in the CO conversion device (6) and the N2 in the blast furnace gas, the ammonia synthesis device (9) causes the H2 generated in the CO conversion device (6), the H2 separated by the pressure swing adsorption hydrogen production device (12) and the N2 in the blast furnace gas to react to generate NH3, and the urea synthesis device (10) causes the NH3 generated in the ammonia synthesis device (9) to react with the CO2 discharged from the CO2 removal device (7) to generate urea; The coke oven gas enters the coke oven gas treatment pipeline (15), the refining device (11) adsorbs and purifies the coke oven gas, the dry reforming device (13) reacts the CO2 discharged from the CO2 removal device (7) with the CH4 in the coke oven gas to generate CO and H2, and the CO and H2 generated in the dry reforming device (13) enter the blast furnace (1) for ironmaking.
10. The method for utilizing blast furnace gas coupled with coke oven gas according to claim 9, characterized in that: The blast furnace gas processing pipeline (14) further comprises a dust removal device (2), a power generation device (3) and a desulfurization device (4) which are connected in sequence from the inlet of the blast furnace gas processing pipeline (14) to the outlet of the blast furnace gas processing pipeline (14). The dust removal device (2), the power generation device (3) and the desulfurization device (4) are located between the blast furnace (1) and the CO conversion device (6). The method for utilizing blast furnace gas coupled with coke oven gas also comprises the following steps: the dust removal device (2) removes dust from the blast furnace gas, the power generation device (3) generates electricity using the pressure energy and thermal energy of the blast furnace gas, and the desulfurization device (4) desulfurizes the blast furnace gas.